Homebrew PCBs

Hi All,

I figure I might as well keep reporting my toner transfer failures 
and successes as it may help someone else.

Brief recap of problem..
Using a wide variety of papers and laser printers, I could not get 
the toner to stick to some PCB material I purchased.  Prior to this 
PCB material, I had very good success doing toner transfer.

During a last ditch effort to complete some circuit boards, I pre-
etched the boards in Ferric Chloride before doing the toner 
transfer, this helped but still wasn't great.

Yesterday, I tried this approach again, pre-etch for about 2 
minutes, followed with a gentle scrubbing with an abrasive pad 
(Scotch bright).  The toner transfered pretty good - about 98%.

Still not sure what the problem is with this particular batch of PCB 
material but I can say that no amount of sanding, cleaning, or 
polishing would allow toner to stick.  So far, the only solution has 
been to pre-etch it.

Perhaps as I get some time to actually experiement, I can't dig in a 
little further, however, should you run into something similar, try 
pre-etching your boards.

Chris

Chris,

I presume you are using a laminator (if not- that is a different 
subject :)))  I am not in favor of pre-etching because it adds 
another wet-dirt operation. What I do is this:
1. Use paper from Staples, stock number is in the database. That ia 
an inkjet paper that I use in my laser printer I got used for $20, 
rather unimpressive (small) Lexmark Optra. I have add that before I 
was trying all kinds of paper and the results were all over the map. 
In fact I have a collection of all kinds of papers and nothing worked 
well FOR ME. I hear that lots of guys are happy with Menstruation 
Press Paper (Bridal Magazine for You, Baking Laminated Cookies, Heavy 
Duty Knitting, etc)- I have't tested that option yet.

2. GBC laminaotor, converted according to a dissertation at 
www.pulsar.gs Great result but I hope never to do it again.

3. kitchen 3M cleaning pad, non metallic.

4. I don't do heavy cleaning in fact I do very little cleaning, clean 
with detergent, clean with the pad, again detergent and dry it out. I 
takes maybe 2 minutes to get it including drying... 

5. Stick the paper onto the PCB roll dozen or so times thru a magic 
Printed Circuit Board Producing Device (PCBPD) and off to a bathtub. 
Few minutes and it's 100% proof. 

Now, I recall having problems that you described when I used steam 
iron (no steam), large PCBs, thin tracks and chancy paper. No amount 
of cleaning would help and I even used a palm sander with all kinds 
of different sand papers. What helped me is using a laminator and the 
correct (for me :))) paper. Mike

Hi Mike, thanks for the info. How thick of a board can you pass 
through that laminator that you modified?

Chris



--- In Homebrew_PCBs@yahoogroups.com, "mikezcnc" <eemikez@c...> 
wrote:
>
> Chris,
> 
> I presume you are using a laminator (if not- that is a different 
> subject :)))  I am not in favor of pre-etching because it adds 
> another wet-dirt operation. What I do is this:
> 1. Use paper from Staples, stock number is in the database. That 
ia 
> an inkjet paper that I use in my laser printer I got used for $20, 
> rather unimpressive (small) Lexmark Optra. I have add that before 
I 
> was trying all kinds of paper and the results were all over the 
map. 
> In fact I have a collection of all kinds of papers and nothing 
worked 
> well FOR ME. I hear that lots of guys are happy with Menstruation 
> Press Paper (Bridal Magazine for You, Baking Laminated Cookies, 
Heavy 
> Duty Knitting, etc)- I have't tested that option yet.
> 
> 2. GBC laminaotor, converted according to a dissertation at 
> www.pulsar.gs Great result but I hope never to do it again.
> 
> 3. kitchen 3M cleaning pad, non metallic.
> 
> 4. I don't do heavy cleaning in fact I do very little cleaning, 
clean 
> with detergent, clean with the pad, again detergent and dry it 
out. I 
> takes maybe 2 minutes to get it including drying... 
> 
> 5. Stick the paper onto the PCB roll dozen or so times thru a 
magic 
> Printed Circuit Board Producing Device (PCBPD) and off to a 
bathtub. 
> Few minutes and it's 100% proof. 
> 
> Now, I recall having problems that you described when I used steam 
> iron (no steam), large PCBs, thin tracks and chancy paper. No 
amount 
> of cleaning would help and I even used a palm sander with all 
kinds 
> of different sand papers. What helped me is using a laminator and 
the 
> correct (for me :))) paper. Mike
>

Chris, 

Thickness of the board is another issue I didn't want to add  it to 
my answer to simplify the matteer. I am using 40 and 60 mills 
fiberglass and 60 mills phenolic crap, that is 45 years old. I am 
also using 10 mills flex. All of them work fine but only AS LONG AS I 
am using that secret paper. The minute I switch to something else I 
get results all over teh map. In fact I can use common laser bond 
paper and get the same results as any other paper except for that 
secret Staples paper.

I tried making my own dextrine paper, I tried printing on aluminum, 
wax paper, baking  paper, lables backing paper (whose idea was that? 
That was insane!), I tried tracing paper, photographic paper, I tried 
plotting on copper directly, I sacrificed my laser printer to laser 
print on copper directly, I tried making my own ink for inkjet *hello 
a new inkjest printer...), I tried machinists paint and scratch and 
etch... and many variations. Now, steam iron works but on small POCBs 
with heavy (to be defined ;) tracks...

All methods produced ok to good results some of the time to most of 
the time. I do not believe in using a pen to correct a laminated PCB.

Once I run out of my secret paper supply I will switch to the PMS 
paper.

What works (FOR ME) is this combination...ok, I won't mention it 
agin, I mentioned it in a previous email.  Mike

It should be possible to figure out if the paper is the problem by  
inspecting the results.
Did the toner stick to the paper? Is it too fibery? Where it transferred,  
are there fibers left or only a white "powder".

If the paper comes off well in some areas, with the right sort of  
grey/white residue left and no (0%) toner left on the paper, in those  
areas, i don't really think the paper is the issue.
With the right pressure and heat you should be able to fuse the toner to  
the board with _any_ paper, the only question beeing if you get the paper  
off without taking the toner with it. But if the toner doesn't even stick  
the problem must be either pressure, temperature, board  
preparation/surface, or some other contamination, but not the paper.

I dunno, it's sure strange, but when i had the problem that it just  
stopped working reliably (with the same paper and material) i decided it  
is my ironing and got the fuser, and the problems went away. I didn't look  
into it then why it suddenly stopped working.

Of course, a paper that works better will be slightly more tolerant  
towards the other factors, but it can't solve a major issue.

ST

Hi Mike,

I think with the toner transfer stuff, what works for any of us 
doesn't actually mean it is going to work for someone else.  There 
are a lot of variables in the process as a whole and that is part of 
the problem with getting universal results.  

Stefan, I believe, is the proponent of using a fuser from a laser 
printer.  I use mostly the .062" thick PCB material and nothing less 
(for no other reason than that is what I can find easily when I need 
it).  So, I am going to keep a watchful eye out for either a used 
laminator or an old laser printer that I can hack the fuser out of.  

I really hate buying something new (like a new laminator) to hack it 
up only to find that it won't work to my expectations :-(  Don't 
mind hacking apart older used stuff though, even if I have to pay a 
few bucks for it.

Thanks again for all the input!

Chris


--- In Homebrew_PCBs@yahoogroups.com, "mikezcnc" <eemikez@c...> 
wrote:
>
> Chris, 
> 
> Thickness of the board is another issue I didn't want to add  it 
to 
> my answer to simplify the matteer. I am using 40 and 60 mills 
> fiberglass and 60 mills phenolic crap, that is 45 years old. I am 
> also using 10 mills flex. All of them work fine but only AS LONG 
AS I 
> am using that secret paper. The minute I switch to something else 
I 
> get results all over teh map. In fact I can use common laser bond 
> paper and get the same results as any other paper except for that 
> secret Staples paper.
> 
> I tried making my own dextrine paper, I tried printing on 
aluminum, 
> wax paper, baking  paper, lables backing paper (whose idea was 
that? 
> That was insane!), I tried tracing paper, photographic paper, I 
tried 
> plotting on copper directly, I sacrificed my laser printer to 
laser 
> print on copper directly, I tried making my own ink for inkjet 
*hello 
> a new inkjest printer...), I tried machinists paint and scratch 
and 
> etch... and many variations. Now, steam iron works but on small 
POCBs 
> with heavy (to be defined ;) tracks...
> 
> All methods produced ok to good results some of the time to most 
of 
> the time. I do not believe in using a pen to correct a laminated 
PCB.

> 
> Once I run out of my secret paper supply I will switch to the PMS 
> paper.
> 
> What works (FOR ME) is this combination...ok, I won't mention it 
> agin, I mentioned it in a previous email.  Mike
>

Stefan,

The fuser that you are using, where did you get it from?  Is there 
anything in particular that I should look for in a used laser 
printer that would make for a good salvageable fuser assembly?

CHris




--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan" 
<stefan_trethan@g...> wrote:
>
> It should be possible to figure out if the paper is the problem 
by  
> inspecting the results.
> Did the toner stick to the paper? Is it too fibery? Where it 
transferred,  
> are there fibers left or only a white "powder".
> 
> If the paper comes off well in some areas, with the right sort of  
> grey/white residue left and no (0%) toner left on the paper, in 
those  
> areas, i don't really think the paper is the issue.
> With the right pressure and heat you should be able to fuse the 
toner to  
> the board with _any_ paper, the only question beeing if you get 
the paper  
> off without taking the toner with it. But if the toner doesn't 
even stick  
> the problem must be either pressure, temperature, board  
> preparation/surface, or some other contamination, but not the 
paper.
> 
> I dunno, it's sure strange, but when i had the problem that it 
just  
> stopped working reliably (with the same paper and material) i 
decided it  
> is my ironing and got the fuser, and the problems went away. I 
didn't look  
> into it then why it suddenly stopped working.
> 
> Of course, a paper that works better will be slightly more 
tolerant  

> towards the other factors, but it can't solve a major issue.
> 
> ST
>

On Tue, 15 Nov 2005 16:13:24 +0100, lcdpublishing  
<lcdpublishing@...> wrote:

> Hi Mike,
>
>
> I think with the toner transfer stuff, what works for any of us
> doesn't actually mean it is going to work for someone else.  There
> are a lot of variables in the process as a whole and that is part of
> the problem with getting universal results.
>
> Stefan, I believe, is the proponent of using a fuser from a laser
> printer.  I use mostly the .062" thick PCB material and nothing less
> (for no other reason than that is what I can find easily when I need
> it).  So, I am going to keep a watchful eye out for either a used
> laminator or an old laser printer that I can hack the fuser out of.
> I really hate buying something new (like a new laminator) to hack it
> up only to find that it won't work to my expectations   Don't
> mind hacking apart older used stuff though, even if I have to pay a
> few bucks for it.
>
> Thanks again for all the input!
>
>
> Chris

I agree, i wouldn't like buying something to hack it, especially if it is  
mostly cheap plastic crap you get these days. OTOH by using current  
products you can offer a reproduceable thing, like pulsar etc.

Also i agree toner transfer seems to be one of the hardest processes to  
communicate to others, although it is so easy to do once it works.


> Stefan,
> The fuser that you are using, where did you get it from?  Is there 
> anything in particular that I should look for in a used laserprinter  
> that would make for a good salvageable fuser assembly?
> CHris

You should look that it is metal not plastic, much easier to work with.
You should look that the rollers can move apart the 2mm or whatever you  
need, often the lower roller is sprung and the bearings ride in a slot,  
this is what you want as it allows you to change spring tension if you  
want. I reckon the newer fusers are probably built like the laminators,  
"fixed width".
Also, you should look that it has a comfortable axle or gear to interface  
your motor to.
You'll also need the thermistor that is usually pressed against the upper  
roller, for temperature control. Remember to keep the electronics for that  
if you have a whole printer, but if you only have a fuser they are cheap  
to build.

I got mine out of a copier, and it's really ideal for the job. nice and  
wide too. In general, the older the machine the better i'd say. Go to the  
place where trash office stuff goes, you are bound to find a printer or  
copier for free. A large copier has HEAPS of interesting parts in it.

ST

aaa, fuser... Chris is not using a laminator!!! Chris, save your time 
on making your own laminator and get yourself a real laminator. I have 
two, one is the GBC200, look in the database section, there is an 
overview what works and what not. Or, get a real laminator, one like 
they used to be, the bigger and bulkier. Those will laminate anything 
you want to anything you have.

So, Chris was was using a steam iron, who would have thunk of 
that...  :))  Mike

OKay, that sounds good. There is a place a few miles away that 
recycles computers and such.  The next time I am up that way I will 
check with them to see what they have.

When using yours, do you have to run the board through a single 
time, or multiple times?

CHris




> You should look that it is metal not plastic, much easier to work 
with.
> You should look that the rollers can move apart the 2mm or 
whatever you  
> need, often the lower roller is sprung and the bearings ride in a 
slot,  
> this is what you want as it allows you to change spring tension if 
you  
> want. I reckon the newer fusers are probably built like the 
laminators,  
> "fixed width".
> Also, you should look that it has a comfortable axle or gear to 
interface  
> your motor to.
> You'll also need the thermistor that is usually pressed against 
the upper  
> roller, for temperature control. Remember to keep the electronics 
for that  
> if you have a whole printer, but if you only have a fuser they are 
cheap  
> to build.
> 
> I got mine out of a copier, and it's really ideal for the job. 
nice and  
> wide too. In general, the older the machine the better i'd say. Go 
to the  
> place where trash office stuff goes, you are bound to find a 
printer or  
> copier for free. A large copier has HEAPS of interesting parts in 
it.

> 
> ST
>

Yes, the iron has been working perfect for me up to the point when I 
got some new PCB material.  That's when everything went to hell with 
the process.  The process I was using that worked perfect was this..

Turn on iron - check with digital thermometer for proper temp 
Put toner transfer paper on PCB
Press down firmly for 15 seconds
Repeat pressing in different locations to cover complete board
Soak board in water for 2 minutes
Etch it.

No problems, till I got the new PCB material.  However, I can easily 
see where a laminator or fuser can give much better and hopefully 
consistant results.

Chris






--- In Homebrew_PCBs@yahoogroups.com, "mikezcnc" <eemikez@c...> wrote:
>
> aaa, fuser... Chris is not using a laminator!!! Chris, save your 
time 
> on making your own laminator and get yourself a real laminator. I 
have 
> two, one is the GBC200, look in the database section, there is an 
> overview what works and what not. Or, get a real laminator, one like 
> they used to be, the bigger and bulkier. Those will laminate 
anything 

> you want to anything you have.
> 
> So, Chris was was using a steam iron, who would have thunk of 
> that...  :))  Mike
>

That's true Stefan, I just wanted to give Chris a clue what might work 
for him because it worked for me and chances are very high it will work 
for everybody, unless they cannot concentrate too well. What did not 
cross my mind that anybody would still use a steam iron ;)))

I like your idea of a fuser but I wanted my PCBs done right now and 
that is why I bought the lamiantor. Then, by sheer accident I got a 
cheap commerical laminator and that just was amazing how well it 
pressed paper against teh PCBs. Many ways to pet a cat.  Mike

On Tue, 15 Nov 2005 16:46:03 +0100, lcdpublishing  
<lcdpublishing@...> wrote:

> OKay, that sounds good. There is a place a few miles away that
>
> recycles computers and such.  The next time I am up that way I will
>
> check with them to see what they have.
>
>
> When using yours, do you have to run the board through a single
>
> time, or multiple times?
>
>
> CHris


single time, i took care to make it run extra slow.
I'm not a 100% sure, but i think i once timed a A4 page (long side) with  
very close to one minute exactly.

Sometimes i will let it run two times, like when i'm using a cardboard  
"feeder" or when i'm transferring both sides at once.

ST

Chris, I see you somewhat admitted your guilt of not using a 
laminator ;) Welcome to a group that can make a 100% proof PCB under 1 
hour at midnight. 

10 times. Wax on, wax off concept... you put it in, you take it out, 
you put it in. 10 times. Your mileage may vary. My Big Berta Laminator 
(BBL) can do it in one pass, hehehe. Mike

I know it works. It works on some sizes, some tracks and now on some 
PCBs. Ironing is not a way to live a quality life. Never was ;) Mike

LOL!

I agree!




--- In Homebrew_PCBs@yahoogroups.com, "mikezcnc" <eemikez@c...> wrote:

>
> I know it works. It works on some sizes, some tracks and now on some 
> PCBs. Ironing is not a way to live a quality life. Never was ;) Mike
>

On Tue, 15 Nov 2005 17:10:14 +0100, mikezcnc <eemikez@...> wrote:

> I know it works. It works on some sizes, some tracks and now on some
>
> PCBs. Ironing is not a way to live a quality life. Never was  Mike
>


You forgot "sometimes". Even on the same PCB with the same iron and layout  
and operator i had it work one time, and not the other. Just too many  
variables i think.

ST

I think I'll stick to photo etching. Print onto transparency with my 
cheap Epson inkjet (green works best for some reason), expose in a light 
box for 7 minutes, Develop in weak caustic soda solution for 2 mins, 
etch.  Works great for me :-) Afterwards I stick board in the cnc mill 
and drill the holes for a perfect finish. Apart from the hassle of 
rubbing off the paper and fixing track breaks with an etch resist pen 
the distortion you get with TT made it impossible for me to drill the 
holes with CNC.

Les




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Hi Les

Is your method written up somewhere?

What sort of linewidths do you have success with? I'm looking at doing some 
work with AD9958 this winter and it has 0.25mm pads on 0.5mm pitch.

tnx
jim

Les, I agree that that is the ultimate method of making PCBs 
but...you forgot to mention follwing problems:
1. You must have a good UV exposure box-- let's not start another 
dicussioon today what that means. It is not a trivial issue although 
for some it might be. The issue here is the resolution because I have 
seen a keproo UV box for $500 failing to give a good resolution on 
TSOP- it was all FUXXY! On quality PCB material, too.I will only 
state that depending what you are building, the uv light may or may 
not work for some or many applications. And let's not expose to sun 
light for a while either :)

2. Once you have the box you need to calibrate the bloody box and 
depending what light it uses the timing might be all over the map, 
depending on the preheated condition of the lamp. Depending on what 
you are using. Calibration alone is not for weak people either.

3. PCB material: buy ready made (expensive), use negative or positive 
(explain it to a nenwcomer), apply film, make your own secret 
emulsion, dry, spray, develop (how long, oops, lets strip it and do 
it again, and again... what teh hell is that today...). Then finally 
comes etching which is trivial..

Now, I am waiting for someone to say that he is happy with scratch 
and etch or printing directly on copper!

Overall, I know that UV is best, and I know it works fine because I 
have the whole process prepared when... when I get tired of TT-ing 
PCBs. So far I don't foresee it. Stick a secret Staples paper in the 
laser printer, hit 'print' and pull the paper out of the printer. 
etch it and remove the paper. Then you drill.  No adjustment process, 
no secret uv boxes.  Mike

On Tue, 15 Nov 2005 18:55:28 +0100, Jim Miller <jim@...> wrote:

> Hi Les
>
>
> Is your method written up somewhere?
>
>
> What sort of linewidths do you have success with? I'm looking at doing  
> some
>
> work with AD9958 this winter and it has 0.25mm pads on 0.5mm pitch.
>
>
> tnx
>
> jim


I do this on toner transfer no problems.
Must work easily with photo.

ST

There isn't much to my system. I use an Epson colour printer with Rapid 
Electronics inkjet transparency. I found that green works best. Black 
and red both seem to have a crazing effect which can cause broken 
tracks. This is with the new Durabrite inks. The older inks seemed to 
work better but my old Stylus Color 600 died. The layout has to be 
printed so the ink side goes towards the board.

The light box is a simple wooden box with four UV tubes about 100mm 
under sheet of glass. There is a sheet of aluminium foil under the tubes 
to reflect the light upwards. There is a lid to clamp the board in place 
while exposing it and I found that a couple of layers of bubble wrap 
between the lid and board gives a good even pressure. When you first set 
up you need to work out how long an exposure is needed. This is pretty 
simple. Print a layout and stick the transparency to a piece of board 
with sticky tape. On the back of the board make a series of marks, 
roughly even spaced. About 7 or 8 will probably do. Place it in the 
light box with a piece of aluminium foil between the board and the 
glass, with one edge lined up with the first mark leaving a small strip 
exposed. Expose the board for 1 minute, move the strip to line up with 
the next mark, expose for 1 minute and so on. You now have a board that 
at one end has been exposed for 8 or 9 minutes and the other end that 
has only been exposed for 1 minute. When you develop the board it is 
quite easy to see where it is under and over developed. Find the best 
part of the board and you will know how long you need to expose the 
board. This is a bit tedious but you only need to do it once. Some 
boards are very sensitive so you may have to repeat the experiment using 
different timing.

Exposure time varies as the tubes warm up so I usually turn them on 
10-15 minutes in advance to give them time to warm up. I use precoated 
board and I can recommend Microtrak board from Mega Electronics - I 
think It is actually made by Bungard. It has a thin coating which 
reduces undercutting and the resist coating is fairly tolerant to 
under/over exposure.  Developer is a level teaspoon of caustic soda 
granules in a litre of water. A few drops of detergent added to the mix 
helps the developer wet the surface. I drop the board in a tray, add 
enough developer to cover the surface then rock the tray. As developing 
progresses you see streaks of darker resist appearing in the developer. 
Once they stop appearing the board is done. A quick dip in the etch tank 
will hilight any areas that have been missed.

I normally use .012" track+gap (~0.3mm) because I know it is reliable. 
0.25T&G shouldn't be a problem. The most important thing is to get a 
good quality print out of your printer. I tried a Lexmark and that 
produced a very fuzzy print.

Les

 about 100mm awa

Jim Miller wrote:

>Hi Les
>
>Is your method written up somewhere?
>
>What sort of linewidths do you have success with? I'm looking at doing some 
>work with AD9958 this winter and it has 0.25mm pads on 0.5mm pitch.
>
>tnx
>jim 
>
>
>
>
>
>
>Be sure to visit the group home and check for new Links, Files, and Photos:
>http://groups.yahoo.com/group/Homebrew_PCBs
>
>If Files or Photos are running short of space, post them here:
>http://groups.yahoo.com/group/Homebrew_PCBs_Archives/ 
>Yahoo! Groups Links
>
>
>
> 
>
>
>
>  
>

Hi Mike,

>Les, I agree that that is the ultimate method of making PCBs 
>but...you forgot to mention follwing problems:
>1. You must have a good UV exposure box-- let's not start another 
>dicussioon today what that means. It is not a trivial issue although 
>for some it might be.
>
I have no problems with a very basic setup. I admit I tend to stick to 
12 thou track/gap because I know it will work every time. For one-offs 
size isn't usually a problem so you can afford to space things out a bit.

>
>2. Once you have the box you need to calibrate the bloody box and 
>depending what light it uses the timing might be all over the map, 
>depending on the preheated condition of the lamp. Depending on what 
>you are using. Calibration alone is not for weak people either.
>  
>
Leaving the box on for 10-15 minutes before use solves the warmup 
problem. Calibration is a little tedious but it isn't exactly difficult. 
You only have to do it once.

>3. PCB material: buy ready made (expensive),
>
Ready made works for me. Yes it is more expensive but not that much more 
expensive. In the small quantities most of us use the increased cost is 
not going to make a noticeable difference to the overall cost of 
building a circuit. The quality of ready made does vary quite widely 
between different suppliers. Mega Electronics for instance sell two 
different types, Microtrak and Fotoboard. They are both near as dammit 
the same price but the Microtrak is miles easier to use.

>Now, I am waiting for someone to say that he is happy with scratch 
>and etch or printing directly on copper!
>  
>
I used to plot directly onto copper but I had problems with the ink 
spreading. One method that did work, and you are gonna laugh at this 
one, was to plot onto photoresist board then expose and etch. The ink 
didn't spread on the photo resist. Exposure time was whatever you 
wanted. Anything from 5 minutes to 30 minutes gave good results. 
Printing onto film is a lot quicker than plotting so I use film these 
days. I like the idea of scratch and etch. One day when I get the right 
software and a few spare hours...

>Overall, I know that UV is best, and I know it works fine because I 
>have the whole process prepared when... when I get tired of TT-ing 
>PCBs. So far I don't foresee it. Stick a secret Staples paper in the 
>laser printer, hit 'print' and pull the paper out of the printer. 
>etch it and remove the paper. Then you drill.  No adjustment process, 
>no secret uv boxes.  Mike
>
>  
>
Your experience with TT must be very different to mine. I spent a cople 
of days in total trying to get it to work and never ended up with 
anything useable. I have a big stack of assorted papers bought from 
Staples and other suppliers. None of them worked reliably. Distortion 
was the final straw. If I got the cnc lined up perfecly on one end of 
the board it would be missing pads completely at the other end of the 
board. Maybe my Samsung laser was the problem. I don't know. I'll stick 
with what works for me :-)

Les

Les Newell wrote:
> Hi Mike,
> 
>>Les, I agree that that is the ultimate method of making PCBs 
>>but...you forgot to mention follwing problems:
>>1. You must have a good UV exposure box-- let's not start another 
>>dicussioon today what that means. It is not a trivial issue although 
>>for some it might be.
> 
> I have no problems with a very basic setup. I admit I tend to stick to 
> 12 thou track/gap because I know it will work every time. For one-offs 
> size isn't usually a problem so you can afford to space things out a bit.

I've done 10cm x 10cm boards full of 8mil tracks and spacing for fine pitch
128pin DSP chips and FPGAs using the uv method and there was no track
breakages or shorts.

>>2. Once you have the box you need to calibrate the bloody box and 
>>depending what light it uses the timing might be all over the map, 
>>depending on the preheated condition of the lamp. Depending on what 
>>you are using. Calibration alone is not for weak people either.
>>  
> Leaving the box on for 10-15 minutes before use solves the warmup 
> problem. Calibration is a little tedious but it isn't exactly difficult. 
> You only have to do it once.

I've found with my 4-flouro tube box, results are consistant as soon as
i use it, which is usually less than 1-2mins after switch-on.

I use a 125 Watt HID box mostly now, and it certainly needs a warm-up
of 5-10mins. Exposure works to ~80-90% in 30secs with precoated negative
pcb, so i use 90secs for excellent results. Calibration was easy.

>>3. PCB material: buy ready made (expensive),

I get my pcb vendor to coat and cut a whole panel, and it works
out very cheap. I store the stuff in the fridge.

made from two draws (from a roadside garbage dump) sawn in half and 
epoxied together. No form of collimation whatsoever, can do .007" 
tracks and spacing with ease. Uses standard daylight bulbs, takes 5 
minutes per side for proper exposure using positive pre-sensitized 
boards ($3.38 each for double sided 6"X4"). I can go from print to 
etched board in less than 30 minutes. You just cannot get this sort 
of workflow or board quality from TT. TT is something for the 
absolute novice IMO....Which was me 5 years ago.

http://www.pbase.com/eldata/image/52321530
http://www.pbase.com/eldata/image/52321539



--- In Homebrew_PCBs@yahoogroups.com, "mikezcnc" <eemikez@c...> 
wrote:
>
> Les, I agree that that is the ultimate method of making PCBs 
> but...you forgot to mention follwing problems:
> 1. You must have a good UV exposure box-- let's not start another 
> dicussioon today what that means. It is not a trivial issue 
although 
> for some it might be. The issue here is the resolution because I 
have 
> seen a keproo UV box for $500 failing to give a good resolution on 
> TSOP- it was all FUXXY! On quality PCB material, too.I will only 
> state that depending what you are building, the uv light may or 
may 
> not work for some or many applications. And let's not expose to 
sun 
> light for a while either :)
> 
> 2. Once you have the box you need to calibrate the bloody box and 
> depending what light it uses the timing might be all over the map, 
> depending on the preheated condition of the lamp. Depending on 
what 
> you are using. Calibration alone is not for weak people either.
> 
> 3. PCB material: buy ready made (expensive), use negative or 
positive 
> (explain it to a nenwcomer), apply film, make your own secret 
> emulsion, dry, spray, develop (how long, oops, lets strip it and 
do 
> it again, and again... what teh hell is that today...). Then 
finally 
> comes etching which is trivial..
> 
> Now, I am waiting for someone to say that he is happy with scratch 
> and etch or printing directly on copper!
> 
> Overall, I know that UV is best, and I know it works fine because 
I 
> have the whole process prepared when... when I get tired of TT-ing 
> PCBs. So far I don't foresee it. Stick a secret Staples paper in 
the 
> laser printer, hit 'print' and pull the paper out of the printer. 
> etch it and remove the paper. Then you drill.  No adjustment 
process, 
> no secret uv boxes.  Mike
>

Les,

Excellent post.

Masny will find that TT combined with CNC drilling is a bad 
combination. (Assuming the CNC is of decent accuracy<G>)

Ballendo

--- In Homebrew_PCBs@yahoogroups.com, Les Newell <lesnewell@h...> 
wrote:
>
> I think I'll stick to photo etching. Print onto transparency with 
my 
> cheap Epson inkjet (green works best for some reason), expose in a 
light 
> box for 7 minutes, Develop in weak caustic soda solution for 2 
mins, 
> etch.  Works great for me :-) Afterwards I stick board in the cnc 
mill 
> and drill the holes for a perfect finish. Apart from the hassle of 
> rubbing off the paper and fixing track breaks with an etch resist 
pen 
> the distortion you get with TT made it impossible for me to drill 
the 

> holes with CNC.
> 
> Les

Think and tinker has step by step directions for an excellent 
exposure setup. Not expensive either.

Calibration is easy inexpensive, and also described.

Ballendo

--- In Homebrew_PCBs@yahoogroups.com, "mikezcnc" <eemikez@c...> 
wrote:
>
> Les, I agree that that is the ultimate method of making PCBs 
> but...you forgot to mention follwing problems:
> 1. You must have a good UV exposure box-- let's not start another 
> dicussioon today what that means. It is not a trivial issue 
although 
> for some it might be. The issue here is the resolution because I 
have 
> seen a keproo UV box for $500 failing to give a good resolution on 
> TSOP- it was all FUXXY! On quality PCB material, too.I will only 
> state that depending what you are building, the uv light may or 
may 
> not work for some or many applications. And let's not expose to 
sun 
> light for a while either :)
> 
> 2. Once you have the box you need to calibrate the bloody box and 
> depending what light it uses the timing might be all over the map, 
> depending on the preheated condition of the lamp. Depending on 
what 
> you are using. Calibration alone is not for weak people either.
> 
> 3. PCB material: buy ready made (expensive), use negative or 
positive 
> (explain it to a nenwcomer), apply film, make your own secret 
> emulsion, dry, spray, develop (how long, oops, lets strip it and 
do 
> it again, and again... what teh hell is that today...). Then 
finally 
> comes etching which is trivial..
> 
> Now, I am waiting for someone to say that he is happy with scratch 
> and etch or printing directly on copper!
> 
> Overall, I know that UV is best, and I know it works fine because 
I 
> have the whole process prepared when... when I get tired of TT-ing 
> PCBs. So far I don't foresee it. Stick a secret Staples paper in 
the 
> laser printer, hit 'print' and pull the paper out of the printer. 
> etch it and remove the paper. Then you drill.  No adjustment 
process, 
> no secret uv boxes.  Mike
>

Seems a lightbox is easier and cheaper than making a laminator...

Ballendo

--- In Homebrew_PCBs@yahoogroups.com, Les Newell <lesnewell@h...> 
wrote:
>
> There isn't much to my system. I use an Epson colour printer with 
Rapid 
> Electronics inkjet transparency. I found that green works best. 
Black 
> and red both seem to have a crazing effect which can cause broken 
> tracks. This is with the new Durabrite inks. The older inks seemed 
to 
> work better but my old Stylus Color 600 died. The layout has to be 
> printed so the ink side goes towards the board.
> 
> The light box is a simple wooden box with four UV tubes about 
100mm 
> under sheet of glass. There is a sheet of aluminium foil under the 
tubes 
> to reflect the light upwards. There is a lid to clamp the board in 
place 
> while exposing it and I found that a couple of layers of bubble 
wrap 
> between the lid and board gives a good even pressure. When you 
first set 
> up you need to work out how long an exposure is needed. This is 
pretty 
> simple. Print a layout and stick the transparency to a piece of 
board 
> with sticky tape. On the back of the board make a series of marks, 
> roughly even spaced. About 7 or 8 will probably do. Place it in 
the 
> light box with a piece of aluminium foil between the board and the 
> glass, with one edge lined up with the first mark leaving a small 
strip 
> exposed. Expose the board for 1 minute, move the strip to line up 
with 
> the next mark, expose for 1 minute and so on. You now have a board 
that 
> at one end has been exposed for 8 or 9 minutes and the other end 
that 
> has only been exposed for 1 minute. When you develop the board it 
is 
> quite easy to see where it is under and over developed. Find the 
best 
> part of the board and you will know how long you need to expose 
the 
> board. This is a bit tedious but you only need to do it once. Some 
> boards are very sensitive so you may have to repeat the experiment 
using 
> different timing.
> 
> Exposure time varies as the tubes warm up so I usually turn them 
on 
> 10-15 minutes in advance to give them time to warm up. I use 
precoated 
> board and I can recommend Microtrak board from Mega Electronics - 
I 
> think It is actually made by Bungard. It has a thin coating which 
> reduces undercutting and the resist coating is fairly tolerant to 
> under/over exposure.  Developer is a level teaspoon of caustic 
soda 
> granules in a litre of water. A few drops of detergent added to 
the mix 
> helps the developer wet the surface. I drop the board in a tray, 
add 
> enough developer to cover the surface then rock the tray. As 
developing 
> progresses you see streaks of darker resist appearing in the 
developer. 
> Once they stop appearing the board is done. A quick dip in the 
etch tank 
> will hilight any areas that have been missed.
> 
> I normally use .012" track+gap (~0.3mm) because I know it is 
reliable. 
> 0.25T&G shouldn't be a problem. The most important thing is to get 
a 
> good quality print out of your printer. I tried a Lexmark and that 
> produced a very fuzzy print.
> 
> Les
> 
>  about 100mm awa
> 
> Jim Miller wrote:
> 
> >Hi Les
> >
> >Is your method written up somewhere?
> >
> >What sort of linewidths do you have success with? I'm looking at 
doing some 
> >work with AD9958 this winter and it has 0.25mm pads on 0.5mm 
pitch.
> >
> >tnx
> >jim 
> >
> >
> >
> >
> >
> >
> >Be sure to visit the group home and check for new Links, Files, 
and Photos:

> >http://groups.yahoo.com/group/Homebrew_PCBs
> >
> >If Files or Photos are running short of space, post them here:
> >http://groups.yahoo.com/group/Homebrew_PCBs_Archives/ 
> >Yahoo! Groups Links
> >
> >
> >
> > 
> >
> >
> >
> >  
> >
>

derekhawkins wrote:
> made from two draws (from a roadside garbage dump) sawn in half and 
> epoxied together. No form of collimation whatsoever, can do .007" 
> tracks and spacing with ease. Uses standard daylight bulbs, takes 5 
> minutes per side for proper exposure using positive pre-sensitized 
> boards ($3.38 each for double sided 6"X4"). I can go from print to 
> etched board in less than 30 minutes. You just cannot get this sort 
> of workflow or board quality from TT. TT is something for the 
> absolute novice IMO....Which was me 5 years ago.
> 
> http://www.pbase.com/eldata/image/52321530
> http://www.pbase.com/eldata/image/52321539

Did you use a single ballast and series connection for those tubes?
How many starters did it need?

>Did you use a single ballast and series connection for those tubes?
>How many starters did it need?

Each "tube" is actually a separate lamp with its own ballast and 
starter. The lamps were on sale at the time with each costing less 
than a single UV tube. Here's a shot of the box with the lamps open 
when only four were installed;

http://www.pbase.com/eldata/image/52324065

More out of curiousity than actually contemplating switching technologies... 
Would it be alright to run acetate through a Laserjet? I have this (likely 
unfounded) fear that it'll make a gooey mess, or at least come out warped 
from the heat. It's probably OK, right? The laminator gets hotter, and I 
don't have a conceptual problem with that.

I've looked at photo-inkjet prints through a 50x microscope (color photos, 
hitting a personal all-time low in grain sniffing), and don't expect the 
print quality to approach that of even my eight year old LJ4. Comments?

Also, is Datak's Tinnit "plating" effective as an etch resist? I'm thinking 
of it in reversing a negative image to a positive.

----- Original Message ----- 

From: "derekhawkins" <derekhawkins@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Tuesday, November 15, 2005 7:32 PM
Subject: [Homebrew_PCBs] A $500.00 "UV" non-trivial exposure box.....


> made from two draws (from a roadside garbage dump) sawn in half and
> epoxied together. No form of collimation whatsoever, can do .007"

On Wed, 16 Nov 2005 02:32:08 +0100, derekhawkins <derekhawkins@...>  
wrote:

> I can go from print to
>
> etched board in less than 30 minutes. You just cannot get this sort
>
> of workflow or board quality from TT. TT is something for the
>
> absolute novice IMO....Which was me 5 years ago.


Well, that's just an opinion, and as such just as valid as mine, which is  
the board quality you get with tt is more than sufficient for 0.5mm pitch  
ICs, and workflow is more streamlined, besides beeing a lot cheaper.  
Photoprocess is surely somethig for the absolute novice, look what radio  
shack and others sell as beginner PCB sets ;-). I was using photoboards 5  
years ago, and i have no desire to go back.

ST

On Wed, 16 Nov 2005 02:44:14 +0100, ballendo <ballendo@...> wrote:

> Seems a lightbox is easier and cheaper than making a laminator...
>
>
> Ballendo


But a lightbox doesn't laminate anything and a laminator doesn't expose  
anything.
What good is the one when you require the other?


ST

derekhawkins wrote:

> made from two draws (from a roadside garbage dump) sawn in half and 
> epoxied together. No form of collimation whatsoever, can do .007" 
> tracks and spacing with ease. Uses standard daylight bulbs, takes 5 
> minutes per side for proper exposure using positive pre-sensitized 
> boards ($3.38 each for double sided 6"X4"). I can go from print to 
> etched board in less than 30 minutes. You just cannot get this sort 
> of workflow or board quality from TT. TT is something for the 
> absolute novice IMO....Which was me 5 years ago.
> 
> http://www.pbase.com/eldata/image/52321530
> http://www.pbase.com/eldata/image/52321539
> 
> 

Hay Derek, you have done some really nice work with your Cannon EOS 20D.

Hi Mike,

It is probably a bad idea to use ordinary acetate. You can get laser 
safe acetate but the results are usually lacking in contrast. As you 
say, lasers do producde nice crisp edges. Inkjet tends to be slightly fuzzy.

Les

Mike Young wrote:

>More out of curiousity than actually contemplating switching technologies... 
>Would it be alright to run acetate through a Laserjet? I have this (likely 
>unfounded) fear that it'll make a gooey mess, or at least come out warped 
>from the heat. It's probably OK, right? The laminator gets hotter, and I 
>don't have a conceptual problem with that.
>
>  
>

If we aren't careful we could end up with a holy war here. I couldn't 
get TT to work and photo etching works well for me. For others the 
opposite is true. Which is the best? The best system is the one that 
works for you.

Les

Stefan Trethan wrote:

>Well, that's just an opinion, and as such just as valid as mine, which is  
>the board quality you get with tt is more than sufficient for 0.5mm pitch  
>ICs, and workflow is more streamlined, besides beeing a lot cheaper.  
>Photoprocess is surely somethig for the absolute novice, look what radio  
>shack and others sell as beginner PCB sets ;-). I was using photoboards 5  
>years ago, and i have no desire to go back.
>
>ST
>
>  
>

I think Ballendo was referring to using a laminator for TT rather than 
for applying photoresist film.

Les

Stefan Trethan wrote:

>But a lightbox doesn't laminate anything and a laminator doesn't expose  
>anything.
>What good is the one when you require the other?
>
>
>ST
>
>
>
>Be sure to visit the group home and check for new Links, Files, and Photos:
>http://groups.yahoo.com/group/Homebrew_PCBs
>
>If Files or Photos are running short of space, post them here:
>http://groups.yahoo.com/group/Homebrew_PCBs_Archives/ 
>Yahoo! Groups Links
>
>
>
> 
>
>
>
>  
>
>

You are wright, is a holy war, but let's make it creative and realy 
useful.
The problem <one method versus another one> is a false problem. "The 
best system is the one that works for you" I agree whith you.
We should try to improve both systems or, if we can, inovate a new 
one.



Adrian


--- In Homebrew_PCBs@yahoogroups.com, Les Newell <lesnewell@h...> 
wrote:
>
> If we aren't careful we could end up with a holy war here. I 
couldn't 

> get TT to work and photo etching works well for me. For others the 
> opposite is true. Which is the best? The best system is the one that 
> works for you.
>

>Hay Derek, you have done some really nice work with your Cannon EOS 
20D.

Thanks!

On Wed, 16 Nov 2005 12:32:30 +0100, adicont2 <adicont2@...> wrote:

> You are wright, is a holy war, but let's make it creative and realy
>
> useful.
>
> The problem <one method versus another one> is a false problem. "The
>
> best system is the one that works for you" I agree whith you.
>
> We should try to improve both systems or, if we can, inovate a new
>
> one.
>
>
>
>
> Adrian


I agree with you.

However, i will not stand by letting people say things i disagree with  
without providing a different point of view.
I do fully accept the photomethod, it is valid, and you get good results,  
and i said so before.
But TT _can_ produce results that are by far enough for advanced people  
(0.5mm pitch ICs is easily sufficient for most, and it isn't even pushing  
the limits). A good TT board is easily as good as a bad photoboard. (and i  
made plenty of those ;-).)
I appreciate it if people say their opinion, which is very valid and sure  
true from their experience. But when i have a different experience i will  
add my point of view. There's no need discussing it to find a agreement,  
the reader can easily find what is true for his situation, but it would be  
unfair not to offer different opinions if they exist.


ST

Well, said Stefan.

All too often people get caught up in the belief there is only one 
way or one opinion on something and everyone should follow that 
singular direction.  If only one side of ANY topic is allowed for 
discussion, well, then we might as well call ourselves lemmings and 
not have any discussions about anything.  

To blindly follow: a concept, idea, method, technique, or otherwise 
anything, is selling oneself short.  All of these topics we discuss 
will have two sides of the story.  Folks can either take what is 
written as gospel and follow along, or they can challenge it, try 
something on their own and perhaps shed some new light on an old 
subject.  Nearly everything written in these forums is based on 
personal experiences and opinions of those experiences.  To squelch 
them, only serves to stiffle creativity and the exploration of 
further truths.

However, this is just my humble opinion :-)




--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan" 
<stefan_trethan@g...> wrote:
>
> On Wed, 16 Nov 2005 12:32:30 +0100, adicont2 <adicont2@y...> wrote:
> 
> > You are wright, is a holy war, but let's make it creative and 
realy
> >
> > useful.
> >
> > The problem <one method versus another one> is a false 
problem. "The
> >
> > best system is the one that works for you" I agree whith you.
> >
> > We should try to improve both systems or, if we can, inovate a 
new
> >
> > one.
> >
> >
> >
> >
> > Adrian
> 
> 
> I agree with you.
> 
> However, i will not stand by letting people say things i disagree 
with  
> without providing a different point of view.
> I do fully accept the photomethod, it is valid, and you get good 
results,  
> and i said so before.
> But TT _can_ produce results that are by far enough for advanced 
people  
> (0.5mm pitch ICs is easily sufficient for most, and it isn't even 
pushing  
> the limits). A good TT board is easily as good as a bad 
photoboard. (and i  
> made plenty of those ;-).)
> I appreciate it if people say their opinion, which is very valid 
and sure  
> true from their experience. But when i have a different experience 
i will  
> add my point of view. There's no need discussing it to find a 
agreement,  
> the reader can easily find what is true for his situation, but it 
would be  

> unfair not to offer different opinions if they exist.
> 
> 
> ST
>

..any comments on safety of using Sodium hydroxide?  

Mike

..and I know of a guy who can layout 5 mills  PLCC44 tracks using just 
3M blue masking tape...

>If we aren't careful we could end up with a holy war here. I couldn't
>get TT to work and photo etching works well for me. For others the
>opposite is true. Which is the best? The best system is the one that
>works for you.

Well, TT worked for me. And all was fine until I started comparing my 
boards to those that were photoetched. TT is cheaper and that's about 
all it has going for it. If your standards and expectations are near 
entry level and you want them to remain there then TT is the way to go. 
However, there should be no question as to which method is able to 
achieve faster and consistently better results. 

--- In Homebrew_PCBs@yahoogroups.com, Les Newell <lesnewell@h...> wrote:
>

In your opinion, not mine. I'm not discussing it further, i've made my  
point.

ST


On Wed, 16 Nov 2005 18:31:00 +0100, derekhawkins <derekhawkins@...>  
wrote:

> Well, TT worked for me. And all was fine until I started comparing my
> boards to those that were photoetched. TT is cheaper and that's about
> all it has going for it. If your standards and expectations are near
> entry level and you want them to remain there then TT is the way to go.
> However, there should be no question as to which method is able to
> achieve faster and consistently better results.

On Wed, 16 Nov 2005 18:23:47 +0100, mikezcnc <eemikez@...> wrote:

> ..any comments on safety of using Sodium hydroxide?
>
>
> Mike
>


I'd say the usual. eyes, skin in higher concentrations. Feels funny, you  
won't like to touch it anyway.

ST

>All too often people get caught up in the belief there is only one
>way 

So true. If one comes to this forum with little or no PCB experience 
one will certainly go away believing that TT is the only sensible way 
to go.

Well, for those whose TT experience is fraught with problems and issues 
(yes you know who you are) there is another way. It's a little more 
expensive and may seem more involved at first but trust me, once 
mastered it will provide faster and better results. So much so, that 
you will be saying to yourself "why did I even waste my time with TT". 
Yes, that was me 5 years ago. 

--- In Homebrew_PCBs@yahoogroups.com, "lcdpublishing" 
<lcdpublishing@y...> wrote:
>

>In your opinion, not mine. I'm not discussing it further, i've made my
>point.

If you were not able to achieve faster and consistently better results 
using photoetching then you never mastered the process due to one 
reason or another. It's as simple as that. 

--- In Homebrew_PCBs@...m, "Stefan Trethan" 
<stefan_trethan@g...> wrote:
>

----- Original Message ----- 

From: "derekhawkins" <derekhawkins@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Wednesday, November 16, 2005 6:01 PM
Subject: [Homebrew_PCBs] Re: A $500.00 "UV" non-trivial exposure box.....


> >In your opinion, not mine. I'm not discussing it further, i've made my
>>point.
>
> If you were not able to achieve faster and consistently better results
> using photoetching then you never mastered the process due to one
> reason or another. It's as simple as that.

I've tried both TT and photo-etching, and much prefer the latter. 
Admittedly, I only used a clothes iron for the TT rather than a laminator, 
but I couldn't see the point of getting a fairly expensive piece of 
equipment that might not work when a simple home-made UV exposure unit would 
cost a lot less and give better results.

Leon 

---
[This E-mail has been scanned for viruses but it is your responsibility 
to maintain up to date anti virus software on the device that you are
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----- Original Message ----- 

From: "mikezcnc" <eemikez@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Wednesday, November 16, 2005 5:23 PM
Subject: [Homebrew_PCBs] Re: A $500.00 "UV" non-trivial exposure box.....


> ..any comments on safety of using Sodium hydroxide?

Once it's mixed it's quite safe, as the solution isn't all that strong 
(about 10 g per litre). Don't get it in your eyes, and rinse it off if it 
gets on the skin.

Leon 

---
[This E-mail has been scanned for viruses but it is your responsibility 
to maintain up to date anti virus software on the device that you are
currently using to read this email. ]

> So true. If one comes to this forum with little or no PCB experience 
> one will certainly go away believing that TT is the only sensible 
way 
> to go.



Well, I wouldn't say that with any certainty.  When I came here a few 
months back (or however long ago it was), I looked at the variety of 
options presented here in the messages, files, and photos sections.

Being familiar with CNC machines, I figured the most direct route for 
me was to do isolation routing.  However, after some discussions and 
some further thinking, I realized isolation routing is probably not 
the best solution for me.

Then I say the photosensitive boards in the catalogs and thought about 
that process. Having worked in a darkroom and working with 
photography, I figured that would be a good direction to go.  

Then I looked at what I could about toner transfer. I have laser 
printers - 3 of them. I have a pretty wide variety of paper on hand to 
try various methods and I have an iron for use in the shop.  It also 
looks like the cheapest to "Get started" with method - didn't really 
need to purchase anything.

So, in my case, I just looked at the options everyone here has 
presented, I chose a path and it worked great the first time out.  
Then things went south when I bought some different PCB material.  
However, being pretty darn new at this, I can't say if I am even close 
to understanding the problems associated with the process, nor do I 
expect to master it anytime soon.  However, trying various things to 
make the process work better and more reliable doesn't cost me much 
(perhaps paper if I see something I want to try).  But, the toner and 
the paper is pretty much zero cost to me.

In my experience, toner transfer is worth further exploration - I have 
all the stuff I need, just not the understanding what causes certain 
problems.  Slowly I am working through the problems and finding 
solutions.  Photo masking will be something I try at some point when I 
need to, but toner transfer will do everything I need it to as I don't 
do any of the tiny trace stuff.

>I've tried both TT and photo-etching, and much prefer the latter.
>Admittedly, I only used a clothes iron for the TT rather than a 
>laminator, but I couldn't see the point of getting a fairly expensive 
>piece of equipment that might not work when a simple home-made UV 
>exposure unit would cost a lot less and give better results.

The prevailing view seems to be that since industry uses photoetching 
then it's far too expensive and too involved for the home. Either that 
or "we must do things differently" prevails. Normally, I don't get 
involved in these TT debates but the insinuation by a poster that one 
needs a $500.00 exposure box for photoetching was too much to resist.

--- In Homebrew_PCBs@yahoogroups.com, "Leon Heller" <leon.heller@b...> 
wrote:
>

----- Original Message ----- 

From: "derekhawkins" <derekhawkins@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Wednesday, November 16, 2005 6:46 PM
Subject: [Homebrew_PCBs] Re: A $500.00 "UV" non-trivial exposure box.....


> >I've tried both TT and photo-etching, and much prefer the latter.
>>Admittedly, I only used a clothes iron for the TT rather than a
>>laminator, but I couldn't see the point of getting a fairly expensive
>>piece of equipment that might not work when a simple home-made UV
>>exposure unit would cost a lot less and give better results.
>
> The prevailing view seems to be that since industry uses photoetching
> then it's far too expensive and too involved for the home. Either that
> or "we must do things differently" prevails. Normally, I don't get
> involved in these TT debates but the insinuation by a poster that one
> needs a $500.00 exposure box for photoetching was too much to resist.

Mine cost me under 25 GBP - just a couple of UV tubes, ballasts and 
starters, some MDF, wood and a piece of glass. It doesn't look very pretty 
but it works very well.

Leon 

---
[This E-mail has been scanned for viruses but it is your responsibility 
to maintain up to date anti virus software on the device that you are
currently using to read this email. ]

On Wed, 16 Nov 2005 19:01:29 +0100, derekhawkins <derekhawkins@...>  
wrote:

>> In your opinion, not mine. I'm not discussing it further, i've made my
>
>> point.
>
>
> If you were not able to achieve faster and consistently better results
>
> using photoetching then you never mastered the process due to one
>
> reason or another. It's as simple as that.
>


Same true in reverse.

ST

Stefan Trethan wrote:

>On Wed, 16 Nov 2005 12:32:30 +0100, adicont2 <adicont2@...> wrote:
>
>  
>
>>You are wright, is a holy war, but let's make it creative and realy
>>
>>useful.
>>
>>The problem <one method versus another one> is a false problem. "The
>>
>>best system is the one that works for you" I agree whith you.
>>
>>We should try to improve both systems or, if we can, inovate a new
>>
>>one.
>>
>>
>>
>>
>>Adrian
>>    
>>
>
>
>I agree with you.
>
>However, i will not stand by letting people say things i disagree with  
>without providing a different point of view.
>  
>
>the reader can easily find what is true for his situation, but it would be  
>unfair not to offer different opinions if they exist.
>
>  
>

  Hmm I'd say 'educated opinions' for that, everyone has opinions, some 
just form them without even beginning to look at all possibilities 
properly first..  An opinion on having only one known or favorite method 
is pretty useless for comparative purposes, no matter who it's from or 
how strongly they have it.  Anti TT people generally never did it enough 
or tried enough printers and materials to achieve success, 'only 
laminators work' people generally just aren't repeatable enough in their 
techniques to get reasonable results with an iron.  Other things can 
work and may even be a bit easier, but TT even with an iron can work 
quite well after a little experimentation and sorting it all out.


"Many will find that TT combined with CNC drilling is a bad

combination. (Assuming the CNC is of decent accuracy<G>)"

Ballendo


Of course, this was more than a bit off.  Takes 3 minutes of 10th grade geometry to fix axis scaling errors.  Anyone not able to  use the relative accuracy of both and scale for absolute accuracy in 15 minutes should really turn their high school diploma back in, they should've flunked the math requirements.

TT combined with CNC is terrific.  TT, CNC, and someone who doesn't know or isn't willing to spend 5 minutes on the net figuring out how to scale something is the bad combination, but of course the fault doesn't lie in either the TT or CNC.  Some people couldn't get to the moon with a space shuttle at hand, others could do it from scratch with a slide rule.  The difference between the two is almost never in the tools, so not much point in blaming them, regardless of which tools are being talked about..

Alan

On Wed, 16 Nov 2005 20:47:47 +0100, Alan King <alan@...> wrote:

>
>
>
> "Many will find that TT combined with CNC drilling is a bad
>
>
> combination. (Assuming the CNC is of decent accuracy<G>)"
>
>
> Ballendo
>
>
>
> Of course, this was more than a bit off.  Takes 3 minutes of 10th grade  
> geometry to fix axis scaling errors.  Anyone not able to  use the
> relative accuracy of both and scale for absolute accuracy in 15 minutes  
> should really turn their high school diploma back in, they
> should've flunked the math requirements.


I found you must first adjust your printer properly, then make a trial  
transfer which you measure, and then simply compensate.
The thing is, if the printer isn't aligned horizontally and vertically you  
usually will have some amount of skew or trapezoid distortions, which is  
hard to compensate. Once it's aligned properly (see service manual, on the  
web for many printers) you have only linear error in x and y which is  
easily compensated for.

This way i got it down to no measurable deviation easily.
Also, while inkjets are often more accurate, you still need a true print  
just the same with photoprocess.

If you have any shrinkage while transferring from the heat simply run the  
paper through the laminator before printing, to dry it properly, then it  
won't shrink any more.

I readily admit i didn't master the photoprocess, but i also now make  
great boards (with legend by the way), much faster, cheaper, and easier  
than i ever did with photoprocess. Even if i mastered it i would need  
considerably more gear, effort, and cost than i do now for TT.
For photoprocess you _need_ sensitized boards (or you have to add the step  
of sensitizing which is again not that easy). They are much more expensive  
than the cheap blank offcuts i get. You _need_  a lightbox to do it  
properly, not necessarily expensive, but surely comparable in building  
effort to a fuser. You _need_ either a inkjet or special (expensive) laser  
paper, i don't have an inkjet and don't want to keep one ever again. You  
need to develop them, which means another step making mess and effort and  
chemicals.

When i make TT i don't need all that. I plug in the fuser to heat up,  
meanwhile go and cutoff and clean a suitable PCB, and print the layout. 3  
minutes max.. Then i cut the layout out, put it on the pcb, feed it  
through the fuser - another minute max.. When it's out i scratch the paper  
with a wirebrush i keep in a desk drawer, and submerge in water (the brush  
rips open the paper and allows water in quicker. Do not brush too much or  
it'll go through and damage the transfer). After a moment in water i take  
it out, hold it over the dustbin, and "roll" the paper off with my thumb  
starting at the center. submerge again to wet it and rub off the rest.  
Submerge again to flush off any paper remains and put in the etcher. two  
minutes max.
That's 6 minutes, and i have have estimated very generously - i'll time it  
next time i make a board.

Did you notice there's NOTHING to prepare or put away? All waste lands in  
the dustbin already. I don't have a sink in the shop so the container with  
the water is filled and emptied when i go by one anyway.

I don't think you can make a photoprocess in the same time, and if it  
surely requires more space to leave all the gear prepared.

But what am i doing, wasting my time here. Let them believe what they want  
i have work to do.

ST

>I don't think you can make a photoprocess in the same time

What size board are you talking about? Can that process as you mention 
even work for a double sided board?

--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan" 
<stefan_trethan@g...> wrote:
>

----- Original Message ----- 

From: "derekhawkins" <derekhawkins@...>
> The prevailing view seems to be that since industry uses photoetching
> then it's far too expensive and too involved for the home. Either that
> or "we must do things differently" prevails. Normally, I don't get
> involved in these TT debates but the insinuation by a poster that one
> needs a $500.00 exposure box for photoetching was too much to resist.

That's a little too far over the top. From a complexity and startup cost 
point of view, the choice is rather simple:

** cost of a UV box, versus cost of a laminator;
** cost of sensitized pre-clad or laminant, versus cost of transfer paper;
** cost and dimensional stability of mylar or acetate, versus short-term 
stability of card stock backed transfer paper.
** cost of developer, versus cost of plain water to remove transfer paper;
** reusability of acetate or mylar, versus one-shot nature of transfer 
paper;
** inkjet or plotter on hand, versus laserjet on hand.

For production runs of many multiples on automated equipment, photo exposure 
has some advantages. For production runs of one or very few, the case for 
100% of "HOMEBREW PCBs", you'll have to explain as though to a young child 
the advantages that offset the cost and complexity of photo exposure.

>For production runs of one or very few, the case for
>100% of "HOMEBREW PCBs", you'll have to explain as though to a young 
>child the advantages that offset the cost and complexity of photo 
>exposure.

We'll get into the quality of the finished product later. Have you ever 
done a double sided board using TT? If yes then explain the TT process.

--- In Homebrew_PCBs@yahoogroups.com, "Mike Young" <mikewhy@s...> wrote:
>

----- Original Message ----- 

From: "Mike Young" <mikewhy@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Wednesday, November 16, 2005 9:11 PM
Subject: Re: [Homebrew_PCBs] Re: A $500.00 "UV" non-trivial exposure 
box.....


> ----- Original Message ----- 
> From: "derekhawkins" <derekhawkins@...>
>> The prevailing view seems to be that since industry uses photoetching
>> then it's far too expensive and too involved for the home. Either that
>> or "we must do things differently" prevails. Normally, I don't get
>> involved in these TT debates but the insinuation by a poster that one
>> needs a $500.00 exposure box for photoetching was too much to resist.
>
> That's a little too far over the top. From a complexity and startup cost
> point of view, the choice is rather simple:
>
> ** cost of a UV box, versus cost of a laminator;
> ** cost of sensitized pre-clad or laminant, versus cost of transfer paper;
> ** cost and dimensional stability of mylar or acetate, versus short-term
> stability of card stock backed transfer paper.
> ** cost of developer, versus cost of plain water to remove transfer paper;
> ** reusability of acetate or mylar, versus one-shot nature of transfer
> paper;
> ** inkjet or plotter on hand, versus laserjet on hand.
>
> For production runs of many multiples on automated equipment, photo 
> exposure
> has some advantages. For production runs of one or very few, the case for
> 100% of "HOMEBREW PCBs", you'll have to explain as though to a young child
> the advantages that offset the cost and complexity of photo exposure.

The process is very reliable, equipment is cheap, dense boards with narrow 
tracks and SM parts are easy, and it is quite fast. Most of my boards are 
one-offs. The main expense is the resist-coated boards.

Leon

Leon 

---
[This E-mail has been scanned for viruses but it is your responsibility 
to maintain up to date anti virus software on the device that you are
currently using to read this email. ]

Of course, it is "unfair not to offer different opinions if they 
exist". From different opinions, we (or some of as)learn something. 
The word "comunication" means "to share" (from Latin). We share ideas, 
opinions and first of all - experencies.


Adrian




--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan" 
<stefan_trethan@g...> wrote:
>
> On Wed, 16 Nov 2005 12:32:30 +0100, adicont2 <adicont2@y...> wrote:
> 
> > You are wright, is a holy war, but let's make it creative and 
realy
> >
> > useful.
> >
> > The problem <one method versus another one> is a false problem. 
"The
> >
> > best system is the one that works for you" I agree whith you.
> >
> > We should try to improve both systems or, if we can, inovate a new
> >
> > one.
> >
> >
> >
> >
> > Adrian
> 
> 
> I agree with you.
> 
> However, i will not stand by letting people say things i disagree 
with  
> without providing a different point of view.
> I do fully accept the photomethod, it is valid, and you get good 
results,  
> and i said so before.
> But TT _can_ produce results that are by far enough for advanced 
people  
> (0.5mm pitch ICs is easily sufficient for most, and it isn't even 
pushing  
> the limits). A good TT board is easily as good as a bad photoboard. 
(and i  
> made plenty of those ;-).)
> I appreciate it if people say their opinion, which is very valid and 
sure  
> true from their experience. But when i have a different experience i 
will  
> add my point of view. There's no need discussing it to find a 
agreement,  
> the reader can easily find what is true for his situation, but it 
would be  

> unfair not to offer different opinions if they exist.
> 
> 
> ST
>

Mike Young wrote:
> That's a little too far over the top. From a complexity and startup cost 
> point of view, the choice is rather simple:
> 
> ** cost of a UV box, versus cost of a laminator;
> ** cost of sensitized pre-clad or laminant, versus cost of transfer paper;
> ** cost and dimensional stability of mylar or acetate, versus short-term 
> stability of card stock backed transfer paper.
> ** cost of developer, versus cost of plain water to remove transfer paper;
> ** reusability of acetate or mylar, versus one-shot nature of transfer 
> paper;
> ** inkjet or plotter on hand, versus laserjet on hand.
> 

Good comparison. I can add.
* learning curve finding a good inkjet transparency/ink combo verses 
finding good TT paper.
* added mess of photoresist developer verses stripping paper from copper.

The choice depends on what process your are currently familiar with and 
what quality you desire. The *potential* quality of photo method will 
always be greater than TT method. If you cannot get expected results 
with TT then switch to the photo method. If TT is working for you then 
why change and go through a whole new leaning curve. If your starting 
out then you have to weigh up the pros/cons of each. IMO both have a 
similar degree of learning. As for subject tile of $500 UV light boxes, 
that surly indicates to me a novice's conception of the photo method.

Adam

On Wed, 16 Nov 2005 22:11:27 +0100, derekhawkins <derekhawkins@...>  
wrote:

>
> What size board are you talking about? Can that process as you mention
>
> even work for a double sided board?


'Course it does, any size you can print.

I'm not going to explain it to someone who has no interest in using that  
knoweledge, look in the archives it was discussed often enough.

Don't say something is no good when you don't have more than a rough idea  
about it please.


ST

----- Original Message ----- 

From: "derekhawkins" <derekhawkins@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Wednesday, November 16, 2005 3:18 PM
Subject: [Homebrew_PCBs] Re: A $500.00 "UV" non-trivial exposure box.....


> >For production runs of one or very few, the case for
>>100% of "HOMEBREW PCBs", you'll have to explain as though to a young
>>child the advantages that offset the cost and complexity of photo
>>exposure.
>
> We'll get into the quality of the finished product later. Have you ever
> done a double sided board using TT? If yes then explain the TT process.

The workflow for both the top vs. bottom (or bottom vs. top) are identical.

-- Combine in Photoshop the artwork for top, bottom, and silkscreen. Print 
this centered onto ordinary bond paper. Trim and tape a piece of transfer 
paper over the artwork, and run it through the printer again, this time 
printing onto the just-right sized piece of transfer paper. Separate the 
three images.

-- Print the drill guide and legend. Stick it to the board with spray mount 
adhesive.

-- Drill and debur the board. There are three unconnected vias in the board 
corners for alignment pins.

-- Pierce the alignment vias on the top artwork; place the pins in the 
board; place the top artwork over the pins. Visually confirm alignment, and 
tape in place. Black toner should occlude all holes.

-- Remove the pins. Tear off a suitable size scrap of bond paper to use as 
slip sheet. Fold in half; place the board with top artwork in the crease. 
Run it through the laminator.

-- Soak off the transfer paper. Pulsar's paper comes off cleanly in a few 
seconds. Dry the board. Examine for alignment errors and incomplete traces.

-- Cut a piece of green sealer paper to size; laminate to the exposed toner.

-- Repeat for the bottom. The sealer prevents the completed top artwork from 
sticking to the slip sheet.

-- Etch.

With one success for one try with the alignment pins, I'm ready to try both 
sides at once. Pulsar's paper releases completely when wet and makes it 
brain dead simple with a clean and deburred board. Slight hole misalignments 
are entirely attributable to imprecise manual drilling. Since the drill 
guide is printed on the same printer as the transferred artwork, I'm not at 
all surprised to not find any systematic errors.

Quality differences? It's difficult to see where the TT process can be 
improved.

You drill before etching?

I do it this order:
For two sides copper and two sides legend:
Print all 4 views, cut out.
Align copper views against light, hold together, place in folded  
cardboard, slide in PCB, run through fuser. (turn over and run again, note  
that the folded cardboard is the secret to keep alignment.)

Remove paper, etch, rinse, scrape off toner.
Do the same as above with legend, only use silicone paper which peels  
easily to leave a black legend (I still have coverage/pinholes problems  
with the silicone paper, so i only use it for legend. But for etching the  
grey paper residue bothers nobody ;-) )

If i only make single-sided i like to do the copper bottom and top legend  
in one go, but sometimes i only have doublesided material so i will  
transfer the legend after etching, like with 2-sided.

I'm not entirely sure if i understood your instructions.

I also use TT to make transfers to aluminum panels and stuff.

ST



On Wed, 16 Nov 2005 23:13:11 +0100, Mike Young <mikewhy@...>  
wrote:

>
>
> -- Print the drill guide and legend. Stick it to the board with spray  
> mount
>
> adhesive.
>
>
> -- Drill and debur the board. There are three unconnected vias in the  
> board
>
> corners for alignment pins.
>
>
> -- Pierce the alignment vias on the top artwork; place the pins in the
>
> board; place the top artwork over the pins. Visually confirm alignment,  
> and
>
> tape in place. Black toner should occlude all holes.
>
>
> -- Remove the pins. Tear off a suitable size scrap of bond paper to use  
> as
>
> slip sheet. Fold in half; place the board with top artwork in the crease.
>
> Run it through the laminator.
>
>
> -- Soak off the transfer paper. Pulsar's paper comes off cleanly in a few
>
> seconds. Dry the board. Examine for alignment errors and incomplete  
> traces.
>
>
> -- Cut a piece of green sealer paper to size; laminate to the exposed  
> toner.
>
>
> -- Repeat for the bottom. The sealer prevents the completed top artwork  
> from
>
> sticking to the slip sheet.
>
>
> -- Etch.

>The workflow for both the top vs. bottom (or bottom vs. top) are 
>identical.

So if you had to do 5 boards you would have to do the following steps 
5 times, once for each board;


----------------------------------------------
-- Combine in Photoshop the artwork for top, bottom, and silkscreen. 
Printthis centered onto ordinary bond paper. Trim and tape a piece of 
transferpaper over the artwork, and run it through the printer again, 
this time printing onto the just-right sized piece of transfer paper. 
Separate the three images.

-- Print the drill guide and legend. Stick it to the board with spray 
mount adhesive.

-- Drill and debur the board. There are three unconnected vias in the 
board corners for alignment pins.

-- Pierce the alignment vias on the top artwork; place the pins in the
board; place the top artwork over the pins. Visually confirm 
alignment, and tape in place. Black toner should occlude all holes.
------------------------------------------------

Do you know how double sided boards are done using photoetching?














--- In Homebrew_PCBs@yahoogroups.com, "Mike Young" <mikewhy@s...> 
wrote:
>
> ----- Original Message ----- 
> From: "derekhawkins" <derekhawkins@y...>
> To: <Homebrew_PCBs@yahoogroups.com>
> Sent: Wednesday, November 16, 2005 3:18 PM
> Subject: [Homebrew_PCBs] Re: A $500.00 "UV" non-trivial exposure 
box.....
> 
> 
> > >For production runs of one or very few, the case for
> >>100% of "HOMEBREW PCBs", you'll have to explain as though to a 
young
> >>child the advantages that offset the cost and complexity of photo
> >>exposure.
> >
> > We'll get into the quality of the finished product later. Have 
you ever
> > done a double sided board using TT? If yes then explain the TT 
process.
> 
> The workflow for both the top vs. bottom (or bottom vs. top) are 
identical.
> 
> -- Combine in Photoshop the artwork for top, bottom, and 
silkscreen. Print 
> this centered onto ordinary bond paper. Trim and tape a piece of 
transfer 
> paper over the artwork, and run it through the printer again, this 
time 
> printing onto the just-right sized piece of transfer paper. 
Separate the 
> three images.
> 
> -- Print the drill guide and legend. Stick it to the board with 
spray mount 
> adhesive.
> 
> -- Drill and debur the board. There are three unconnected vias in 
the board 
> corners for alignment pins.
> 
> -- Pierce the alignment vias on the top artwork; place the pins in 
the 
> board; place the top artwork over the pins. Visually confirm 
alignment, and 
> tape in place. Black toner should occlude all holes.
> 
> -- Remove the pins. Tear off a suitable size scrap of bond paper to 
use as 
> slip sheet. Fold in half; place the board with top artwork in the 
crease. 
> Run it through the laminator.
> 
> -- Soak off the transfer paper. Pulsar's paper comes off cleanly in 
a few 
> seconds. Dry the board. Examine for alignment errors and incomplete 
traces.
> 
> -- Cut a piece of green sealer paper to size; laminate to the 
exposed toner.
> 
> -- Repeat for the bottom. The sealer prevents the completed top 
artwork from 
> sticking to the slip sheet.
> 
> -- Etch.
> 
> With one success for one try with the alignment pins, I'm ready to 
try both 
> sides at once. Pulsar's paper releases completely when wet and 
makes it 
> brain dead simple with a clean and deburred board. Slight hole 
misalignments 
> are entirely attributable to imprecise manual drilling. Since the 
drill 
> guide is printed on the same printer as the transferred artwork, 
I'm not at 
> all surprised to not find any systematic errors.
> 
> Quality differences? It's difficult to see where the TT process can 
be 
> improved.
>

>Align copper views against light, hold together, place in folded
>cardboard, slide in PCB 

Oh yeah, takes only 5 seconds. So if you had five boards it would only 
set you back 25 seconds. Do you have any shots of your double sided 
work?

--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan" 
<stefan_trethan@g...> wrote:
>

----- Original Message ----- 

From: "derekhawkins" <derekhawkins@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Wednesday, November 16, 2005 4:37 PM
Subject: [Homebrew_PCBs] Re: A $500.00 "UV" non-trivial exposure box.....


> >The workflow for both the top vs. bottom (or bottom vs. top) are
>>identical.
>
> So if you had to do 5 boards you would have to do the following steps
> 5 times, once for each board;

The same would seem to apply to photo resist. Drill it; align artwork; 
expose/laminate; develop/strip the paper backing. The step-by-step for photo 
would seem to be longer.

In my mind, photo resist is still coming up short. There are more variables, 
more opportunities for error, more equipment to acquire, maintain, and 
adjust. And more junk in the sewers (not that I lose sleep over what my 
neighbors might be doing or not).

All that aside, the quality of the artwork would seem to be paramount. The 
laserjet prints very clean, very crisp edges. Filled areas are very dense 
black and consistent. The Epson 1280 (28800 dpi) only manages a fuzzy edge, 
not crisp at all, and not nearly as dense. If both are available, I expect 
you would choose the laserjet. And if you're printing on the laserjet 
anyway, why not go straight to the board for the onesie-twosie?

Actually, I didn't intend to seem so polarized. I'm asking it as a question, 
as a newbie with no experience with photo, and only very little with TT. 
What is the advantage of photo-resist compared to toner transfer?

On Wed, 16 Nov 2005 23:45:18 +0100, derekhawkins <derekhawkins@...>  
wrote:

>
>
> Oh yeah, takes only 5 seconds. So if you had five boards it would only
>
> set you back 25 seconds. Do you have any shots of your double sided
>
> work?


Not one where you see what you want (alignment i guess).

<http://tinypic.com/ftn5nn.jpg>

was the last one, but i made no straight on shot and none from the bottom  
where most stuff is. Also, it's barely two sided, using only the pin  
headers as vias. Note that i use oblong pads so the copper you see on the  
left (where it isn't soldered top-side) isn't offset.
If you take care you can get the alignment just as good as with photo,  
it's the same task, but i still prefer single-sided quite often because  
without THP the second side isn't so useful to me.

Especially if you have no lightbox with light on both sides it can be  
tricky to align, and flip over, photoboards, as i remember.

ST

----- Original Message ----- 

From: "Stefan Trethan" <stefan_trethan@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Wednesday, November 16, 2005 4:25 PM
Subject: Re: [Homebrew_PCBs] Re: A $500.00 "UV" non-trivial exposure 
box.....


> You drill before etching?

Eagle's drill legend makes it a breeze; turn off the brain and poke the 
right sized drill at the right symbols.

Also, I'm working up the verve to try plating the through-holes. The holes 
have to be there before etching to plate them. I wrote Dow Corning for a 
30cc sample of their conductive ink; too expensive to buy (Think and Tinker) 
just for an experiment. Anyway, it's a long proof of concept. There's no 
hope of plating the holes if drilling before etching doesn't work for me. 
It's working well enough; I would be more pleased if I could remove my fat 
fingers from the results.

> Remove paper, etch, rinse, scrape off toner.
> Do the same as above with legend, only use silicone paper which peels
> easily to leave a black legend (I still have coverage/pinholes problems
> with the silicone paper, so i only use it for legend. But for etching the
> grey paper residue bothers nobody ;-) )

What grey paper is that? I'm using Pulsar's paper, which works very well: 
releases very cleanly and easily.

> I'm not entirely sure if i understood your instructions.

Just a long winded way of saying: align, heat and press, soak in the sink 
for a few seconds. Repeat for side two.

Mike Young wrote:
> ----- Original Message ----- 
> From: "derekhawkins" <derekhawkins@...>
> To: <Homebrew_PCBs@yahoogroups.com>
> Sent: Wednesday, November 16, 2005 4:37 PM
> Subject: [Homebrew_PCBs] Re: A $500.00 "UV" non-trivial exposure box.....
> 
> 
>>>The workflow for both the top vs. bottom (or bottom vs. top) are
>>>identical.
>>
>>So if you had to do 5 boards you would have to do the following steps
>>5 times, once for each board;
> 
> The same would seem to apply to photo resist. Drill it; align artwork; 
> expose/laminate; develop/strip the paper backing. The step-by-step for photo 
> would seem to be longer.

It's much easier. You only need to make the front and back printouts *once*.
(I have a draw full of re-useable printouts).

You lay one printout on top of the other and align them and stick them together
with two small pieces of double-sided foam tape (it is commonly 1.6mm which is
the same as the pcb thickness). This is a 30s operation, and easy after the
first time.

 From then-on, whenever you want to make a double-sided pcb, just put the
blank into the sandwich, then put that into the lightbox and expose for
90secs. Turn over and do the other side for 90secs. Pull out pcb and remove
cellophane plastic layer from pcb. Put into flat container that has 10g/L
of swimming-pool NaCO3 (sodium carbonate pre-heated in microwave for 30secs
to 25-30degC). Brush developer for 1-2mins until well done, repeating for
both sides. Rinse, then put into flat tray with 10g/L NaOH (sodium hydroxide
garage floor cleaner), and heat in microwave for 1min to 50-60degC. The resist
just wrinkles and falls off. Rinse then dry. No scrubbing or cleaning is needed
anywhere.

> In my mind, photo resist is still coming up short. There are more variables, 
> more opportunities for error, more equipment to acquire, maintain, and 
> adjust. And more junk in the sewers (not that I lose sleep over what my 
> neighbors might be doing or not).

Calibrate the lightbox *once* to match your pcb. Nothing else needs adjusting.

> All that aside, the quality of the artwork would seem to be paramount. The 
> laserjet prints very clean, very crisp edges. Filled areas are very dense 
> black and consistent. The Epson 1280 (28800 dpi) only manages a fuzzy edge, 
> not crisp at all, and not nearly as dense.

You're obviously using either crap ink, crap transparency or both. Genuine
epson ink and transparency gives a sharpness and density you couldn't fault.
There are certain refill inks and transparency that give acceptable results
too.

 > If both are available, I expect
> you would choose the laserjet. And if you're printing on the laserjet 
> anyway, why not go straight to the board for the onesie-twosie?

Double-sided pcbs with TT are a pain. Laminators cost a lot more than
building a lightbox. Lightboxes are a lot easier to build than a laminator.
TT can use non-coated pcb. You can spray on positive resist to pcb after
adequate cleaning, but a lot of users don't master the cleaning step.
You can apply your own dry-film resist to pcb, but it's a bit tedious
without the right machine.

> Actually, I didn't intend to seem so polarized. I'm asking it as a question, 
> as a newbie with no experience with photo, and only very little with TT. 
> What is the advantage of photo-resist compared to toner transfer?

>The same would seem to apply to photo resist

Not quite. You print the artwork only once (both sides for double 
sided). You then align both sides and permanently fix the alignment 
of top and bottom transparencies using tape. A lightbox is not 
necessary for the alignment since you're dealing with 
transparencies. This packet is then good for any amount of boards. 
You never have to print or align the artwork again.

You then slide a board in the packet, temporarily fix it using tape 
and expose one side. Flip it for the other side. Remove the tape, 
slide out the board then insert another and so on. When done you 
develop them.

>All that aside, the quality of the artwork would seem to be 
>paramount. The laserjet prints very clean, very crisp edges. Filled 
>areas are very dense black and consistent.

Quite the opposite on transparencies. Take a look here;

http://www.pbase.com/eldata/lasvsink

While the inkjet edges are more jagged this is actually a non-issue 
since with the right exposure time those edges disappear. What you 
cannot see in the laser print is the pin holes and dropouts that 
will lead to holes and pits in the tracks. The same holes and pits 
that are often there after etching a TT board. You just need greater 
magnification in order to see them. The transfer of toner from paper 
to copper is far from perfect.

>The Epson 1280 (28800 dpi) only manages a fuzzy edge,not crisp at 
>all, and not nearly as dense.

Fuzzy edge was discussed above but density of an inkjet print on 
transparencies should always be several times greater than that of a 
laserjet. You need to use Epson inkjet transparencies.

>If both are available, I expect you would choose the laserjet.

No, just the opposite. Furthermore, just about every laser printer I 
have used has issues when it comes to CNC drilling. And this is not 
something scaling can correct since it's inconsistent.

>And if you're printing on the laserjet anyway, why not go straight 
>to the board for the onesie-twosie?

When you magnify the tracks of your TT boards, do you really like 
what you see?


--- In Homebrew_PCBs@yahoogroups.com, "Mike Young" <mikewhy@s...> 
wrote:
>

>While the inkjet edges are more jagged this is actually a non-issue
>since with the right exposure time those edges disappear.

I should have posted this shot of a single sided board (made from 
inkjet artwork) in my previous post to demonstrate why injket jagged 
edges in print are a non-issue but forgot. This is a macro shot at 
original size, look carefully at the edges;

http://www.pbase.com/eldata/image/46673206/original

--- In Homebrew_PCBs@yahoogroups.com, "derekhawkins" 
<derekhawkins@y...> wrote:
>

----- Original Message ----- 

From: "Russell Shaw" <rjshaw@...>
> You lay one printout on top of the other and align them and stick them 
> together
> with two small pieces of double-sided foam tape (it is commonly 1.6mm 
> which is
> the same as the pcb thickness). This is a 30s operation, and easy after 
> the
> first time.

I like that. Simple is good. Seems to me I have room for a small lightbox on 
the worktable. What would you suggest?

>> All that aside, the quality of the artwork would seem to be paramount. 
>> The
>> laserjet prints very clean, very crisp edges. Filled areas are very dense
>> black and consistent. The Epson 1280 (28800 dpi) only manages a fuzzy 
>> edge,
>> not crisp at all, and not nearly as dense.
>
> You're obviously using either crap ink, crap transparency or both. Genuine
> epson ink and transparency gives a sharpness and density you couldn't 
> fault.
> There are certain refill inks and transparency that give acceptable 
> results
> too.

Actually, it's very expensive ink, and better in the Epson than the Epson 
ink. I fancy myself a photographer in other moments. Granted, everything 
seen through a 50x microscope looks flawed. The LJ is just less flawed than 
the inkjet.

> > If both are available, I expect
>> you would choose the laserjet. And if you're printing on the laserjet
>> anyway, why not go straight to the board for the onesie-twosie?
>
> Double-sided pcbs with TT are a pain. Laminators cost a lot more than
> building a lightbox. Lightboxes are a lot easier to build than a 
> laminator.

My laminator cost $50. Even with a lightbox, I would still want to use it 
for panels.

> TT can use non-coated pcb. You can spray on positive resist to pcb after
> adequate cleaning, but a lot of users don't master the cleaning step.
> You can apply your own dry-film resist to pcb, but it's a bit tedious
> without the right machine.

And expensive, at least at Think and Tinker's prices. Committing to 50 sq. 
ft. of material is asking quite a bit.

Very nice. What's the plating? or is that just a trick of the light?

----- Original Message ----- 

From: "derekhawkins" <derekhawkins@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Wednesday, November 16, 2005 8:03 PM
Subject: [Homebrew_PCBs] Re: A $500.00 "UV" non-trivial exposure box.....


> >While the inkjet edges are more jagged this is actually a non-issue
>>since with the right exposure time those edges disappear.
>
> I should have posted this shot of a single sided board (made from
> inkjet artwork) in my previous post to demonstrate why injket jagged
> edges in print are a non-issue but forgot. This is a macro shot at
> original size, look carefully at the edges;
>
> http://www.pbase.com/eldata/image/46673206/original
>
> --- In Homebrew_PCBs@yahoogroups.com, "derekhawkins"
> <derekhawkins@y...> wrote:
>>
>
>
>
>
>
>
>
> Be sure to visit the group home and check for new Links, Files, and 
> Photos:
> http://groups.yahoo.com/group/Homebrew_PCBs
>
> If Files or Photos are running short of space, post them here:
> http://groups.yahoo.com/group/Homebrew_PCBs_Archives/
> Yahoo! Groups Links
>
>
>
>
>
>

>Very nice. What's the plating? or is that just a trick of the light?

It's tinned using plumber's solder paste. Doesn't wet and smoothen as 
well as the more expensive stuff, hence the little pips here and 
there. It was discussed here sometime back.

--- In Homebrew_PCBs@yahoogroups.com, "Mike Young" <mikewhy@s...> 
wrote:
>

----- Original Message ----- 

From: "derekhawkins" <derekhawkins@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Wednesday, November 16, 2005 7:49 PM
Subject: [Homebrew_PCBs] Re: A $500.00 "UV" non-trivial exposure box.....


> >The same would seem to apply to photo resist
>
> Not quite. You print the artwork only once (both sides for double
> sided). You then align both sides and permanently fix the alignment

Yes, Russell made the same point. Almost compelling. We could have gotten 
here sooner without the posturing, no?

>>All that aside, the quality of the artwork would seem to be
>>paramount. The laserjet prints very clean, very crisp edges. Filled
>>areas are very dense black and consistent.
>
> Quite the opposite on transparencies. Take a look here;
>
> http://www.pbase.com/eldata/lasvsink
>
> While the inkjet edges are more jagged this is actually a non-issue
> since with the right exposure time those edges disappear. What you
> cannot see in the laser print is the pin holes and dropouts that
> will lead to holes and pits in the tracks. The same holes and pits
> that are often there after etching a TT board. You just need greater
> magnification in order to see them. The transfer of toner from paper
> to copper is far from perfect.

The Pulsar paper releases very cleanly. You'll see the dropouts as effluent 
in the soak water. That hasn't happened since fugging up the first board 
with raised burrs.

>
>>The Epson 1280 (28800 dpi) only manages a fuzzy edge,not crisp at
>>all, and not nearly as dense.
>
> Fuzzy edge was discussed above but density of an inkjet print on
> transparencies should always be several times greater than that of a
> laserjet. You need to use Epson inkjet transparencies.

It won't be even close. Pigment inks, maybe possibly, but not dyes. If you 
also have a laserjet, hold up one of each to a bright light.

>
>>If both are available, I expect you would choose the laserjet.
>
> No, just the opposite. Furthermore, just about every laser printer I
> have used has issues when it comes to CNC drilling. And this is not
> something scaling can correct since it's inconsistent.

That will be surprising, and I'll check it later as well. Seems 
counter-intuitive that the rickety mechanism on plebian inkjets can hold 
tighter tolerance than non-moving parts. (I'm assuming a lot, since I don't 
really know what the laserjet really does in its dark innards.)

>
>>And if you're printing on the laserjet anyway, why not go straight
>>to the board for the onesie-twosie?
>
> When you magnify the tracks of your TT boards, do you really like
> what you see?

They're icky, likely from over etching. Still working on that part. I'll 
hook up the scanner later and see what we see at 4800 dpi.

Mike Young wrote:
> ----- Original Message ----- 
> From: "Russell Shaw" <rjshaw@...>
> 
>>You lay one printout on top of the other and align them and stick them 
>>together with two small pieces of double-sided foam tape (it is commonly 1.6mm 
>>which is the same as the pcb thickness). This is a 30s operation, and easy after 
>>the first time.
> 
> I like that. Simple is good. Seems to me I have room for a small lightbox on 
> the worktable. What would you suggest?

A box with four 15Watt flouros (tubes about 20cm long), and 10-20cm from glass
where PCBs lie. Because i haven't used a flouro box for a while, there's a
chance that exposure may be too quick and you'll have to use less tubes.
Paint the inner sides of the box matt black, and have a good flat white
reflective surface behind the tubes. You can use long parabolic reflectors
if you can get them, and that they don't put out extra bright spots on your pcb
(reflectors are best if you want long distance like 20cm or more).

>>>All that aside, the quality of the artwork would seem to be paramount. 
>>>The laserjet prints very clean, very crisp edges. Filled areas are very dense
>>>black and consistent. The Epson 1280 (28800 dpi) only manages a fuzzy 
>>>edge, not crisp at all, and not nearly as dense.
>>
>>You're obviously using either crap ink, crap transparency or both. Genuine
>>epson ink and transparency gives a sharpness and density you couldn't 
>>fault. There are certain refill inks and transparency that give acceptable 
>>results too.
> 
> Actually, it's very expensive ink, and better in the Epson than the Epson 
> ink.

It doesn't matter how expensive it is, if it's not compatible with the
transparency. I've seen replacement ink that's supposed to give equal
results on photo quality inkjet paper, but it doesn't work on the
epson transparency.

Unlike other transparencies that are just a rough sandpapery surface,
the epson stuff has a gelatine absorbing coating. Print heavy in epson
ink and you'll see the droplets absorb and sink into it. Other ink just
sits on top.

Certain combinations of refill ink and transparency can give adequate
resolution, but take longer to dry, and may not be as dark (still dark
enough tho).

If you use expensive epson transparency and ink, do a quick rough printout
on normal paper, then stick down a piece of transparency the right size,
and feed back thru for a final print. A packet of transparency lasts a
lot longer then. I only use the epson stylus 400 color (720dpi) for pcbs,
so the ink lasts a long time. I also only do negative printouts and have
large copper fills, so minimal ink is used for large boards. It would be
better to use a later model epson because the ink is cheaper and you get
1440 or 2880dpi (720dpi is adequate tho).

 > I fancy myself a photographer in other moments. Granted, everything
> seen through a 50x microscope looks flawed. The LJ is just less flawed than 
> the inkjet.

Non-linear dimensional warming of paper in a laser printer is a problem for
cnc and doing larger double-sided PCBs.

>>>If both are available, I expect
>>>you would choose the laserjet. And if you're printing on the laserjet
>>>anyway, why not go straight to the board for the onesie-twosie?
>>
>>Double-sided pcbs with TT are a pain. Laminators cost a lot more than
>>building a lightbox. Lightboxes are a lot easier to build than a 
>>laminator.
> 
> My laminator cost $50. Even with a lightbox, I would still want to use it 
> for panels.
> 
>>TT can use non-coated pcb. You can spray on positive resist to pcb after
>>adequate cleaning, but a lot of users don't master the cleaning step.
>>You can apply your own dry-film resist to pcb, but it's a bit tedious
>>without the right machine.
> 
> And expensive, at least at Think and Tinker's prices. Committing to 50 sq. 
> ft. of material is asking quite a bit.

----- Original Message ----- 

From: "derekhawkins" <derekhawkins@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Wednesday, November 16, 2005 8:24 PM
Subject: [Homebrew_PCBs] Re: A $500.00 "UV" non-trivial exposure box.....


> >Very nice. What's the plating? or is that just a trick of the light?
>
> It's tinned using plumber's solder paste. Doesn't wet and smoothen as
> well as the more expensive stuff, hence the little pips here and
> there. It was discussed here sometime back.

I caught the tail-end of some discussion when I joined the list. Can you 
recap very briefly? Just smear it on and then into the toaster oven?

>It won't be even close. Pigment inks, maybe possibly, but not dyes. 
>If you also have a laserjet, hold up one of each to a bright light.

Regardless of ink type, the density of laserjet print **on 
transparencies** will always be vastly inferior to inkjet print. Just 
about everybody knows that.

>They're icky, likely from over etching. Still working on that part. 

You're a prime candidate for switching if that bothers you because 
that's the characteristic signature of a TT board. It's due to hand-me-
down toner....LOL!



--- In Homebrew_PCBs@yahoogroups.com, "Mike Young" <mikewhy@s...> 
wrote:
>

Russell Shaw wrote:
> Mike Young wrote:
> 
>> ----- Original Message ----- From: "derekhawkins" 
>> <derekhawkins@...>
>> To: <Homebrew_PCBs@yahoogroups.com>
>> Sent: Wednesday, November 16, 2005 4:37 PM
>> Subject: [Homebrew_PCBs] Re: A $500.00 "UV" non-trivial exposure box.....
>>
...

> From then-on, whenever you want to make a double-sided pcb, just put the
> blank into the sandwich, then put that into the lightbox and expose for
> 90secs. Turn over and do the other side for 90secs. Pull out pcb and remove
> cellophane plastic layer from pcb. Put into flat container that has 10g/L
> of swimming-pool NaCO3 (sodium carbonate pre-heated in microwave for 30secs
> to 25-30degC). Brush developer for 1-2mins until well done, repeating for
> both sides.

Now etch for 7-8mins in ferric-chloride bubble etcher at room-temp, or put
into flat tray and brush over with paint brush. After bubble etching, it's
always a good idea to brush a bit to etch any stubborn parts. Precoated
boards get more stubborn areas of unetched copper you can get etched by
this brushing step, and the problem gets worse with age. I've still got
perfect results from 5-year old board i kept in a fridge, after some
brushing. The bubble etcher was $50 from a shop and is slightly larger
area than an A4 page (it stands vertical).

 > Rinse, then put into flat tray with 10g/L NaOH (sodium
> hydroxide garage floor cleaner), and heat in microwave for 1min to 50-60degC. The 
> resist just wrinkles and falls off. Rinse then dry. No scrubbing or cleaning is 
> needed anywhere.

--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan"
<stefan_trethan@g...> wrote:

> Align copper views against light, hold together, place in folded  
> cardboard, slide in PCB, run through fuser. (turn over and run
again, note  
> that the folded cardboard is the secret to keep alignment.)
>

Could you elaborate on the folded cardboard? I'm having a problem
visualizing exactly what you are doing. I'm assuming you tape the
copperviews to maintian alignment, and then slip them into the folded
over cardboard to hold them and the pcb laminate static during the 2
passes through the laminator. 

Also, did you have to mod the laminator to deal with the thicker
stack? Then again, I tend to think of cardboard as 3-4mm thick,
perhaps what you are using is thinner.

Currently, I use a Kepro exposure system, and it works extremely well,
but the time savings for TT are making me think of revisiting the process.

Thanks
Ron

i've got an hp7960 printer. is there any experience with inks and 
transparencies that might indicate potential success with this unit?

tnx
jtm

Jim Miller wrote:
> i've got an hp7960 printer. is there any experience with inks and 
> transparencies that might indicate potential success with this unit?

I tested canons and HPs a few years ago and they had crappy transparency
that took ages for the ink to dry.

HPs use thermal boiling of the ink which easily leads to heads clogged
with viscous half boiled goo. Epsons use piezo electric plungers that
don't heat the ink. Canons were thermal too iirc.

Haven't tried lexmark or other brands since. Things may be better now.
Even with a slower drying printout, the resolution may be adequate
depending on what you want. All you can do is try.

Stay away from epson stylus 680 (a fairly old model, but newer than the
stylus 400/440/460 series) because mechanically they're a piece of crap
with unreliable paper pickup.

----- Original Message ----- 

From: "derekhawkins" <derekhawkins@...>
> >It won't be even close. Pigment inks, maybe possibly, but not dyes.
>>If you also have a laserjet, hold up one of each to a bright light.
>
> Regardless of ink type, the density of laserjet print **on
> transparencies** will always be vastly inferior to inkjet print. Just
> about everybody knows that.

I don't know it, so I guess I'll have to prove it for myself. I'll run some 
through the lab's densitometer later in the week.

>>They're icky, likely from over etching. Still working on that part.
>
> You're a prime candidate for switching if that bothers you because
> that's the characteristic signature of a TT board. It's due to hand-me-
> down toner....LOL!

I puzzled over this for a little bit, and it niggled at me as I hurried 
through a small board so I would have something to scan. Could it be your 
standards differ than mine? Higher? Lower? That doesn't seem right; quality 
is quality. I'm used to commercially produced prototype boards. Certainly I 
have no expectation my own boards will be in the same league. But laughably 
inferior? No, that doesn't seem right. The first few boards were OK. Not 
great; just OK. The holes aren't plated, and the pads could use a good 
fluxing and tinning. But the copper itself was just fine, better than just 
OK. And then it hit me, as I stared at the toner black traces staring back 
at me from the rinse water. That's rather odd...

Pulsar sells a green sealing film to overcoat the toner. In my haste this 
evening, I forgot to apply it. I had etched the board with only the toner 
for a resist. Sure enough, wiping off the toner with Goof-Off left a behind 
a mottled mess where there should be shiny copper. The trace edges were 
pitted; and the SL3 pads were... just yuck. It would take a blind man to 
miss the difference, never mind the microscopy.

Derek, I know now what you must be saying. Toner alone is not a very good 
resist. However, combined with a sealing film, such as Pulsar's green TRF, 
toner transfer is every bit as good as any other process. And it's fast, 
too. As late as it is over here, I know I can just run off another one 
before heading to bed.

----- Original Message ----- 

From: "Russell Shaw" <rjshaw@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Thursday, November 17, 2005 2:30 AM
Subject: Re: [Homebrew_PCBs] Re: A $500.00 "UV" non-trivial exposure 
box.....


> It doesn't matter how expensive it is, if it's not compatible with the
> transparency. I've seen replacement ink that's supposed to give equal
> results on photo quality inkjet paper, but it doesn't work on the
> epson transparency.
>
> Unlike other transparencies that are just a rough sandpapery surface,
> the epson stuff has a gelatine absorbing coating. Print heavy in epson
> ink and you'll see the droplets absorb and sink into it. Other ink just
> sits on top.
>
> Certain combinations of refill ink and transparency can give adequate
> resolution, but take longer to dry, and may not be as dark (still dark
> enough tho).

Mega sells sheets of film specifically made for PCB transparencies in both 
laser and ink-jet printers. The laser printer stuff works very well, but is 
expensive, so I usually use tracing paper. I keep meaning to buy some of the 
ink-jet film to try in my Epson.

http://www.megauk.com/

Look for JetStar and LaserStar under Artwork Aids. There is a new JetStar 
Premium film for high res.

I'll get some JetStar film when I get back from a short holiday, and try it. 
I'll ask them what the best printer is, for it.

Leon 

---
[This E-mail has been scanned for viruses but it is your responsibility 
to maintain up to date anti virus software on the device that you are
currently using to read this email. ]

I have the Techniks Press n peel heat press and ran into some bad  
luck with a bad batch of pnp. If I were to use Pulsar paper, what  
would be a good starter time and temperature for the press?
TM

Hi Derek and group
Good job Derek with drawers & camera.
I read all messages in this group and have never read something I want to
point to the group.
The idea is to build a UV box "from a roadside garbage dump" desktop
scanner. You have the box, the glass, the lid and maybe the mains switch in
the older (newer have DC supply) and pilot led. All of them already cut and
assembled. Of course, you must to empty the remaining hardware and
accomodate the lamps, starters and only one ballast for 4/5 lamps (the ones
that are employed in the mosquitos traps of abt 30 cms.)
I guess the glasses in these scanners must be good quality, ie., well flat
and parallel faces.
Here I have already "empty" 3 scanners that are waiting in my shelves to
accept the modification.
Additionally, if you save the original neon lamp+support+inverter you get a
nice 12VDC neon lamp to operate from battery in black-outs. Do not forget
the steppers, belts, etc.
Thanks for reading.
Jose.

----- Original Message ----- 

From: "derekhawkins" <derekhawkins@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Wednesday, November 16, 2005 2:32 AM
Subject: [Homebrew_PCBs] A $500.00 "UV" non-trivial exposure box.....


> made from two draws (from a roadside garbage dump) sawn in half and
> epoxied together. No form of collimation whatsoever, can do .007"
> tracks and spacing with ease. Uses standard daylight bulbs, takes 5
> minutes per side for proper exposure using positive pre-sensitized
> boards ($3.38 each for double sided 6"X4"). I can go from print to
> etched board in less than 30 minutes. You just cannot get this sort
> of workflow or board quality from TT. TT is something for the
> absolute novice IMO....Which was me 5 years ago.
>

The best thing to do is try. Get some transparency and print a board on 
it. Hold the transparency up to the light. If the lines are dense and 
clean then you are probably on to a winner. A lot of modern inks have UV 
blocking pigments so you don't always have to use black. For instance 
with Epson Durabrite inks I found green seems to work best. The 
transparencies come out looking fairly pale but they work well.

As with any pcb making system the secret of success is to keep 
experimenting.

Les

Jim Miller wrote:

>i've got an hp7960 printer. is there any experience with inks and 
>transparencies that might indicate potential success with this unit?
>
>tnx
>jtm 
>  
>

On Thu, 17 Nov 2005 00:34:14 +0100, Mike Young <mikewhy@...>  
wrote:

>
>
> What grey paper is that? I'm using Pulsar's paper, which works very well:
>
> releases very cleanly and easily.


It's not grey, but the white clay on the paper and the black toner make  
the residue appear greyish. It's just inkjet paper.

ST

On Thu, 17 Nov 2005 02:49:28 +0100, derekhawkins <derekhawkins@...>  
wrote:

>
>
> When you magnify the tracks of your TT boards, do you really like
>
> what you see?


YES! ;-)

Is there anyone going to change the subject line?
tnx

Stefan Trethan <stefan_trethan@...> wrote:  On Thu, 17 Nov 2005 02:49:28 +0100, derekhawkins 
wrote:

>
>
> When you magnify the tracks of your TT boards, do you really like
>
> what you see?


YES! ;-)




		
---------------------------------
 Yahoo! FareChase - Search multiple travel sites in one click.  

[Non-text portions of this message have been removed]

You guessed right, relatively thin cardboard. maybe 0.5mm. Like the big  
parts of cornflakes boxes.

Again, the procedure:
You cut your layout pretty close to the board edge, but with 2cm border on  
one side (same side both layouts).
Then you put together the toner sides, and slide around holding against a  
light until it matches.
Now you should have prepared that cardboard, folded in the middle, well  
larger than the PCB, because you open the folded piece with one hand, and  
slide the layout in with the excess border towards the folded edge. Now  
you hold the three pieces together with your other hand, from the outside  
of the cardboard, on the folded edge. This allows you to slide the PCB in  
and position (this is why you had to cut it close to the board outline on  
all but one side, makes positioning easier). Let the cardboard close and  
simply hold the stack together (pressing at the PCB). Feed the whole thing  
folded edge first. Depending on your fuser you might want a second pass  
flipped over, or even two more runs with the cardboard missing. The paper  
should be stuck fast by now.

The strange thing is, if you do this without the cardboard the fuser will  
"drag" one paper forward, at the board edge. If you imagine the papers  
beeing together with zero distance before the board, and 1.5mm then,  
there's a 1.5mm length to be taken from somewhere. With the cardboard  
feeder, although it makes a crease in it where the board starts, there  
seems to be no such movement.

The fuser could easily take the added thickness without modification,  
dunno about other machines. But you can also tack it with a iron if you  
run into trouble. Then you needn't even use the cardboard, as the iron  
doesn't move anything.

ST

On Thu, 17 Nov 2005 04:09:12 +0100, Ron <mnphysicist@...> wrote:

>
> Could you elaborate on the folded cardboard? I'm having a problem
>
> visualizing exactly what you are doing. I'm assuming you tape the
>
> copperviews to maintian alignment, and then slip them into the folded
>
> over cardboard to hold them and the pcb laminate static during the 2
>
> passes through the laminator.
>
>
> Also, did you have to mod the laminator to deal with the thicker
>
> stack? Then again, I tend to think of cardboard as 3-4mm thick,
>
> perhaps what you are using is thinner.
>

Greetings from the UK. I joined this group a week or so ago. So I am  
new to all this. I have just used the toner method and it seems to  
work fine for me. I am happy.

1] I used one of those abrasive PCB cleaner blocks to get a shiny  
board, making sure not to touch it with greasy fingers afterwards.  
Deburring the edges is easy, you just whack them down the edge of a  
metal table to fold the copper back down. Use a file if you must.

2] Printed my images using an Apple Laserwriter 4/600. I found an  
ancient Mac OS9 version of the laserwriter utility that lets a person  
set the default print density on the printer. The toner cartridge was  
an exchange refill, so nothing special there.

3] Used the wife's domestic iron on a hot setting. Once the paper had  
started to stick down I could happily move the iron around to give an  
even heat. I think the art here is to maintain intimate connection of  
paper and PCB without using undue pressure on the iron to squidge the  
pads and tracks. I didn't time it or anything. After a few trial  
boards it worked fine for me.

I Tried several papers I had around the house. I used a paper often  
used for digital prints called 'Mellotex'. This is made by Tullis  
Russel. Free UK samples 0800 74 74 77. This seems to work OK, I get a  
good dense black but it is a bit hairy. After a good soak in water  
the hairs mostly come off. I found the black toner was so well bonded  
on I could scrub the boards. I also tried a paper called Detec, also  
used a lot by digital print houses, but that was no good at all. The  
wife's silicon baking parchment worked wonderfully on the transfer  
side of things, but didn't accept a very dense coating of toner to  
start with, so I abandoned it.

I looked up that Staples glossy paper, but the UK order codes don't  
seem to match the US ones. Can anyone identify the paper I should try  
for me please?
<http://www.staples.co.uk/ENG/Catalog/cat_class.asp? 
CatIds=1101,1287&name=UK%5FCL%5FPhoto+Paper>

4] Did a quick very minor touch-up with a Staedtler Lumocolor pen.  
318 series. I read that people insist on the red pen, but I used  
black and it works just fine. This I shall have to hide so that my  
wife doesn't steal it for writing on freezer bags in the kitchen.

5] Into a ferric chloride bath

6] Erm, not sure my wife realises her nail varnish remover has  
disappeared yet.

7] Drilled the holes with a cheap but very solid cast metal pillar  
drill that takes a standard drill. This cost 5 GBP, about 8.6 US  
bucks, from LIDL, a European chain store. I've been drilling .5mm  
holes happily on this.

Excellent. Job done. A cheap answer to my needs. I was going to use  
Press'n'Peel but I won't bother with that expense unless I want to  
get down to really fine work. Is P'n'P really that great?

Whoop John

i'm a complete newbie to this. what transparencies would you suggest? are 
there pcb specific ones? what are sources in the US? i assume this isn't 
office depot stuff...

tnx
jim

----- Original Message ----- 
From: "Les Newell" <lesnewell@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Thursday, November 17, 2005 4:25 AM
Subject: Re: [Homebrew_PCBs] Re: A $500.00 "UV" non-trivial exposure 
box.....


The best thing to do is try. Get some transparency and print a board on
it.

----- Original Message ----- 

From: "Jim Miller" <jim@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Thursday, November 17, 2005 12:46 PM
Subject: Re: [Homebrew_PCBs] Re: A $500.00 "UV" non-trivial exposure 
box.....


> i'm a complete newbie to this. what transparencies would you suggest? are
> there pcb specific ones? what are sources in the US? i assume this isn't
> office depot stuff...

Tracing paper works quite well and is cheap. It might look opaque, but it is 
quite transparent to UV. It's what I use most of the time with a laser 
printer.

Leon
--
Leon Heller, G1HSM
leon.heller@...
http://www.geocities.com/leon_heller 

---
[This E-mail has been scanned for viruses but it is your responsibility 
to maintain up to date anti virus software on the device that you are
currently using to read this email. ]

ANother thought I had about using the photo-resist boards was the 
potential for another problem that I don't know if there is a work 
around or not.

If you expose a board and the exposure doesn't work out as planed, 
it is then ruined isn't it?  

For example, with toner transfer, if it turns out bad, a missing or 
pitted traces or whatever else can go wrong, I wash off the toner 
and do it again and again till it is good enough for what I need.  
The only loss I have is time and paper.

However, from an ignorant point of view ( I have never tried this 
process), if something goes wrong, the board can't be used again in 
the potoresist process can it?  

Also, as I don't know what things look like along the way, can you 
see the traces with the resist on them after developing?  If so, 
what does the developed photoresist look like?

TIA

Chris

----- Original Message ----- 

From: "lcdpublishing" <lcdpublishing@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Thursday, November 17, 2005 3:55 PM
Subject: [Homebrew_PCBs] Re: A $500.00 "UV" non-trivial exposure box.....


> ANother thought I had about using the photo-resist boards was the
> potential for another problem that I don't know if there is a work
> around or not.
>
> If you expose a board and the exposure doesn't work out as planed,
> it is then ruined isn't it?

When you get the process right, that is very rare.

>
> For example, with toner transfer, if it turns out bad, a missing or
> pitted traces or whatever else can go wrong, I wash off the toner
> and do it again and again till it is good enough for what I need.
> The only loss I have is time and paper.
>
> However, from an ignorant point of view ( I have never tried this
> process), if something goes wrong, the board can't be used again in
> the potoresist process can it?

Not unless you strip off all the old resist and use dry-film or spray 
resist. The latter doesn't work very well.

>
> Also, as I don't know what things look like along the way, can you
> see the traces with the resist on them after developing?  If so,
> what does the developed photoresist look like?

There is a faint image after developing.

Leon 

---
[This E-mail has been scanned for viruses but it is your responsibility 
to maintain up to date anti virus software on the device that you are
currently using to read this email. ]

Hi Jim,

Actually it is Office Depot stuff :-) Transparencies are often used on 
overhead projectors so any decent stationery supplier should stock it. 
You must make sure you get transparency that is designed for inkjet.

Les

Jim Miller wrote:

>i'm a complete newbie to this. what transparencies would you suggest? are 
>there pcb specific ones? what are sources in the US? i assume this isn't 
>office depot stuff...
>
>tnx
>jim
>
>  
>



-- 
No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.1.362 / Virus Database: 267.13.3/173 - Release Date: 16/11/2005

Hmm, that sounds like a good idea. I must give it a go.

Thanks,
Les

Leon Heller wrote:

>Tracing paper works quite well and is cheap. It might look opaque, but it is 
>quite transparent to UV. It's what I use most of the time with a laser 
>printer.
>
>Leon
>  
>



-- 
No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.1.362 / Virus Database: 267.13.3/173 - Release Date: 16/11/2005

It usually doesn't go wrong once you figured out how to do it, but the  
same is the case with TT, i very rarely have a bad transfer.

With my photoboards the resist was discolored faintly after exposure (i  
think it was yellowish but not 100% sure). After developing one could see  
it quite well, it was kind of smoky transparent.
My main problems were exposure (getting a decent film was impossible with  
my laser printer and the papers/transparencies i had. I used this spray  
for a while that makes paper translucent, but it was not really good, it  
works great as label remover tho.)
Also, i had some old board material that didn't develop very well.
I'm sure i could have gotten it to work eventually, but TT seemed, and is,  
so much less work, and this way i can also make component legend and front  
panels and stuff (even my a house number sign is a PCB!).

ST


On Thu, 17 Nov 2005 16:55:36 +0100, lcdpublishing  
<lcdpublishing@...> wrote:

>
> If you expose a board and the exposure doesn't work out as planed,
>
> it is then ruined isn't it?
>
>
> For example, with toner transfer, if it turns out bad, a missing or
>
> pitted traces or whatever else can go wrong, I wash off the toner
>
> and do it again and again till it is good enough for what I need.
>
> The only loss I have is time and paper.
>
>
> However, from an ignorant point of view ( I have never tried this
>
> process), if something goes wrong, the board can't be used again in
>
> the potoresist process can it?
>
>
> Also, as I don't know what things look like along the way, can you
>
> see the traces with the resist on them after developing?  If so,
>
> what does the developed photoresist look like?
>
>
> TIA
>
>
> Chris
>

Could you accept to change the subject?

At 07:35 PM 11/17/2005, you wrote:

>It usually doesn't go wrong once you figured out how to do it, but the
>same is the case with TT, i very rarely have a bad transfer.
>
>With my photoboards the resist was discolored faintly after exposure (i
>think it was yellowish but not 100% sure). After developing one could see
>it quite well, it was kind of smoky transparent.
>My main problems were exposure (getting a decent film was impossible with
>my laser printer and the papers/transparencies i had. I used this spray
>for a while that makes paper translucent, but it was not really good, it
>works great as label remover tho.)
>Also, i had some old board material that didn't develop very well.
>I'm sure i could have gotten it to work eventually, but TT seemed, and is,
>so much less work, and this way i can also make component legend and front
>panels and stuff (even my a house number sign is a PCB!).
>
>ST
>
>
>On Thu, 17 Nov 2005 16:55:36 +0100, lcdpublishing
><lcdpublishing@...> wrote:
>
> >
> > If you expose a board and the exposure doesn't work out as planed,
> >
> > it is then ruined isn't it?
> >
> >
> > For example, with toner transfer, if it turns out bad, a missing or
> >
> > pitted traces or whatever else can go wrong, I wash off the toner
> >
> > and do it again and again till it is good enough for what I need.
> >
> > The only loss I have is time and paper.
> >
> >
> > However, from an ignorant point of view ( I have never tried this
> >
> > process), if something goes wrong, the board can't be used again in
> >
> > the potoresist process can it?
> >
> >
> > Also, as I don't know what things look like along the way, can you
> >
> > see the traces with the resist on them after developing?  If so,
> >
> > what does the developed photoresist look like?
> >
> >
> > TIA
> >
> >
> > Chris
> >
>
>
>
>
>
>Be sure to visit the group home and check for new Links, Files, and Photos:
>http://groups.yahoo.com/group/Homebrew_PCBs
>
>If Files or Photos are running short of space, post them here:
>http://groups.yahoo.com/group/Homebrew_PCBs_Archives/
>Yahoo! Groups Links
>
>
>
>

Stefan Trethan wrote:

>
>But what am i doing, wasting my time here. Let them believe what they want  
>i have work to do.
>
>ST
>  
>


  Heard that.  Part of the reason I've dropped in and out of the 
discussions lately has been working on more important things.  
Especially now with PCBEx cutting the quantity in half from CustomPCB, a 
single even low volume producing product can pay for made boards.  
$125+ship for five 8x10 boards is simply very reasonable.  I still have 
my stack of 4 laserjets and will test out direct print to board fully 
when other things are going a bit more smoothly, but until then I doubt 
I'll make many more boards by hand, TT or UV.  Simply too cheap to have 
them made, I doubt you can come out much ahead even if you just count 
minimum wage for your time..  Still ok if you just have to have an 
instant board, but that usually isn't so important vs a week or so.

Alan

Alan King wrote:

>...Especially now with PCBEx cutting the quantity in half from CustomPCB, a 
>single even low volume producing product can pay for made boards.  
>$125+ship for five 8x10 boards is simply very reasonable.  
>  
>
Can you be a bit more specific about this? 

David

Hi John, sounds like our processes are very similar!  I have been 
trying different papers around the house and office and most seem to 
work.  Don't use my wifes nail polish remover though, I use 
the "Manly" version called acetone :-)

I haven't tried the staples paper yet myself, but will sooner or 
later.

As for press-n-peel, I have no idea as I have never used it.  
However, I have seen some of the stuff at the local radio shack and 
most of it looks wider than the .010" I am getting using toner 
transfer.  Don't know anything more about it other than a quick 
glance of the "stickers" hanging on the wall there.

The most recent toner transfer lesson I have learned (or am 
learning) is that not all PCB material is the same.  I have tried 
about 3 different brands/types of pcb material and all worked 
fantastic.  Then I bought some from a different company and 
everything started getting really bad for the toner transfer.  I 
tried sanding, buffing with 1000 grit, scrubbing with scotch bright 
pads, cleaning with every solvent in sight and nothing worked.  The 
final solution - a pre-soak in Ferric Chloride for a few minutes, 
then a good cleaning etc. Worked good on the last two circuit boards 
I etched.

It's a neat process and kind of fun too!

Chris




--- In Homebrew_PCBs@yahoogroups.com, whoop@b... wrote:
>
> Greetings from the UK. I joined this group a week or so ago. So I 
am  
> new to all this. I have just used the toner method and it seems 
to  
> work fine for me. I am happy.
> 
> 1] I used one of those abrasive PCB cleaner blocks to get a shiny  
> board, making sure not to touch it with greasy fingers 
afterwards.  
> Deburring the edges is easy, you just whack them down the edge of 
a  
> metal table to fold the copper back down. Use a file if you must.
> 
> 2] Printed my images using an Apple Laserwriter 4/600. I found an  
> ancient Mac OS9 version of the laserwriter utility that lets a 
person  
> set the default print density on the printer. The toner cartridge 
was  
> an exchange refill, so nothing special there.
> 
> 3] Used the wife's domestic iron on a hot setting. Once the paper 
had  
> started to stick down I could happily move the iron around to give 
an  
> even heat. I think the art here is to maintain intimate connection 
of  
> paper and PCB without using undue pressure on the iron to squidge 
the  
> pads and tracks. I didn't time it or anything. After a few trial  
> boards it worked fine for me.
> 
> I Tried several papers I had around the house. I used a paper 
often  
> used for digital prints called 'Mellotex'. This is made by Tullis  
> Russel. Free UK samples 0800 74 74 77. This seems to work OK, I 
get a  
> good dense black but it is a bit hairy. After a good soak in 
water  
> the hairs mostly come off. I found the black toner was so well 
bonded  
> on I could scrub the boards. I also tried a paper called Detec, 
also  
> used a lot by digital print houses, but that was no good at all. 
The  
> wife's silicon baking parchment worked wonderfully on the 
transfer  
> side of things, but didn't accept a very dense coating of toner 
to  
> start with, so I abandoned it.
> 
> I looked up that Staples glossy paper, but the UK order codes 
don't  
> seem to match the US ones. Can anyone identify the paper I should 
try  
> for me please?
> <http://www.staples.co.uk/ENG/Catalog/cat_class.asp? 
> CatIds=1101,1287&name=UK%5FCL%5FPhoto+Paper>
> 
> 4] Did a quick very minor touch-up with a Staedtler Lumocolor 
pen.  
> 318 series. I read that people insist on the red pen, but I used  
> black and it works just fine. This I shall have to hide so that 
my  
> wife doesn't steal it for writing on freezer bags in the kitchen.
> 
> 5] Into a ferric chloride bath
> 
> 6] Erm, not sure my wife realises her nail varnish remover has  
> disappeared yet.
> 
> 7] Drilled the holes with a cheap but very solid cast metal 
pillar  
> drill that takes a standard drill. This cost 5 GBP, about 8.6 US  
> bucks, from LIDL, a European chain store. I've been drilling .5mm  
> holes happily on this.
> 
> Excellent. Job done. A cheap answer to my needs. I was going to 
use  
> Press'n'Peel but I won't bother with that expense unless I want 
to  

> get down to really fine work. Is P'n'P really that great?
> 
> Whoop John
>

just got back from office depot with some of their house brand inkjet 
transparency material. also got some translucent vellum used for making 
fancy greeting card inserts with inkjets.

i'm going to make up some test patterns with a fineline serpentine next to a 
fineline interwoven to act as open/short test patterns. i'm then planning to 
step and repeat this on a page so i can try different colors on the 
patterns. finally i'm planning to do this with a 1-8 interval exposure test.

any recommendations on any of these phases? any suggestions on color 
selection? i was going to try straight hp primaries (red, yellow, blue) and 
black. i also saw green mentioned which would be a yellow/blue mix i guess.

of course i'll post results.

tnx
jim

David P Harris wrote:

>Alan King wrote:
>
>  
>
>>...Especially now with PCBEx cutting the quantity in half from CustomPCB, a 
>>single even low volume producing product can pay for made boards.  
>>$125+ship for five 8x10 boards is simply very reasonable.  
>> 
>>
>>    
>>
>Can you be a bit more specific about this? 
>
>David
>
>  
>
http://www.pcbex.com/
https://maxima5.abac.com/pcbex/product_index.asp
http://www.pcbex.com/product_help.asp

  But some hinges on their "We do not accommodate gold fingers, step & 
repeat, cutouts or blind/buried vias in our standard prototype PCB 
online order.".  Actually a bit irritating that someone ever wrote that 
sentence as is, 'step & repeat' refers to so many different things it's 
a silly error to have not qualified it.  Panelizing your order for you 
is a small PITA for them so many won't do it on prototypes etc, on the 
other hand some people slackly use it to also refer to a pre-done 
board.  Long as they'll take my 8x10 then they'll be right in line with 
CustomPCB's 8x11, and have mask too.  If on the other hand they complain 
about my several boards that I will cut out to my needs later, then 
they'll be a bit behind CustomPCB on overall pricing.  Needless to say 
I'll be sure and report how it goes.  I should have already had these 
in, just had too many other things happening at once.  Actually, while I 
have it up I'm sending an email to support and a picture of the panel to 
see, may as well find out now.  They'd still be quite reasonable on some 
things, just not on a panelized setup if they won't..

Alan

On Thu, 17 Nov 2005 11:55:55 +0100, <whoop@...> wrote:

>
>
> Excellent. Job done. A cheap answer to my needs. I was going to use
>
> Press'n'Peel but I won't bother with that expense unless I want to
>
> get down to really fine work. Is P'n'P really that great?
>
>
> Whoop John


I've never used PnP, but i strongly doubt it can increase the resolution.
My experiments have shown that you can make traces down to 6.66 mil  
reliably with inkjet paper, but 3.33mil and smaller won't come out right  
due to underetching. I don't think this is a resist question, i suspect it  
can only be overcome with a better etching system, although the resist  
might also have to do with it. See
<http://trethan.at.tf/pub/img1/PCB2.JPG>
for a test i did a while back.

ST

P.S.: Better get a old clothes iron, some acetone for yourself, and a  
stock of spare staedtler pens to surrender as long as you still can ;-)

On Thu, 17 Nov 2005 22:51:31 +0100, Alan King <alan@...> wrote:

> Actually a bit irritating that someone ever wrote that
>
> sentence as is, 'step & repeat' refers to so many different things it's
>
> a silly error to have not qualified it.


I think it comes from CNC.

It is about as silly as "silkscreen" for component legend, i don't like it  
either.

You considered olimex?

ST

lcdpublishing wrote:

>As for press-n-peel, I have no idea as I have never used it.  
>However, I have seen some of the stuff at the local radio shack and 
>most of it looks wider than the .010" I am getting using toner 
>transfer.  Don't know anything more about it other than a quick 
>glance of the "stickers" hanging on the wall there.
>
>  
>

  The sticker like things are dry transfer, not press n peel, so maybe 
you're mixing the two.  Never seen PnP at Rat Shack, but haven't been 
there much recently either..  PnP looks like a blank sheet, and is 
almost the same as TT since it's just a special sheet to print on for TT..

http://www.techniks.com/retail.htm

  Look there, the sheet is all blue and you print on it, there isn't 
anything pre-printed..

Alan

Alan King wrote:
> Stefan Trethan wrote:
> 
>>But what am i doing, wasting my time here. Let them believe what they want  
>>i have work to do.
> 
>   Heard that.  Part of the reason I've dropped in and out of the 
> discussions lately has been working on more important things.  
> Especially now with PCBEx cutting the quantity in half from CustomPCB, a 
> single even low volume producing product can pay for made boards.  
> $125+ship for five 8x10 boards is simply very reasonable.  I still have 
> my stack of 4 laserjets and will test out direct print to board fully 
> when other things are going a bit more smoothly, but until then I doubt 
> I'll make many more boards by hand, TT or UV.  Simply too cheap to have 
> them made, I doubt you can come out much ahead even if you just count 
> minimum wage for your time..  Still ok if you just have to have an 
> instant board, but that usually isn't so important vs a week or so.
> 
> Alan

Even if they gave the boards to me for free, it's still much more expensive
than doing it myself. If i design a pcb, i can build it in an hour keeping
my same train of thought and get a result, and even iterate a new board if
needed. Getting them made outside means waiting atleast a week (usually two
or three unless you pay double).

lcdpublishing wrote:
> ANother thought I had about using the photo-resist boards was the 
> potential for another problem that I don't know if there is a work 
> around or not.
> 
> If you expose a board and the exposure doesn't work out as planed, 
> it is then ruined isn't it?  

If you haven't developed it, you can expose it more if you align
the printout again with what you can see on the resist.

> For example, with toner transfer, if it turns out bad, a missing or 
> pitted traces or whatever else can go wrong, I wash off the toner 
> and do it again and again till it is good enough for what I need.  
> The only loss I have is time and paper.
> 
> However, from an ignorant point of view ( I have never tried this 
> process), if something goes wrong, the board can't be used again in 
> the potoresist process can it?

Not after developing. However, you can scrape bits of resist
off with a scriber and add bits with a resist pen.

> Also, as I don't know what things look like along the way, can you 
> see the traces with the resist on them after developing?  If so, 
> what does the developed photoresist look like?

Undeveloped, the patterns look slightly lighter or darker than
unexposed areas. When developed, you can see the copper.

Russell Shaw wrote:

>
>Even if they gave the boards to me for free, it's still much more expensive
>than doing it myself. If i design a pcb, i can build it in an hour keeping
>my same train of thought and get a result, and even iterate a new board if
>needed. Getting them made outside means waiting atleast a week (usually two
>or three unless you pay double).
>
>  
>


  Hey, if you need that, then knock yourself out.  I can generally 
remember exactly what I was doing a week or two later, and don't have 
the slightest problem with a 2 week delay on that front..  But for sure, 
after costs and time you're not coming out as much ahead of my $3 per 
board as you are thinking, and I'm getting PTH, mask, and not even 
having to make a board..

Alan

Alan King wrote:
> Russell Shaw wrote:
> 
>>Even if they gave the boards to me for free, it's still much more expensive
>>than doing it myself. If i design a pcb, i can build it in an hour keeping
>>my same train of thought and get a result, and even iterate a new board if
>>needed. Getting them made outside means waiting atleast a week (usually two
>>or three unless you pay double).
> 
>   Hey, if you need that, then knock yourself out.  I can generally 
> remember exactly what I was doing a week or two later, and don't have 
> the slightest problem with a 2 week delay on that front.

That means i have to find something else to do while the client waits
because of ones laziness to do it themself.

> But for sure, 
> after costs and time you're not coming out as much ahead of my $3 per 
> board as you are thinking, and I'm getting PTH, mask, and not even 
> having to make a board..

I'd still be in front compared to waiting for two weeks for a pcb and
having the pcb vendor pay me $200. Anything more than simple PCBs usually
need a second refinement, and it's far better to have the vendor make
only the final design.

Russell Shaw wrote:

>Alan King wrote:
>  
>
>>Russell Shaw wrote:
>>
>>    
>>
>>>Even if they gave the boards to me for free, it's still much more expensive
>>>than doing it myself. If i design a pcb, i can build it in an hour keeping
>>>my same train of thought and get a result, and even iterate a new board if
>>>needed. Getting them made outside means waiting atleast a week (usually two
>>>or three unless you pay double).
>>>      
>>>
>>  Hey, if you need that, then knock yourself out.  I can generally 
>>remember exactly what I was doing a week or two later, and don't have 
>>the slightest problem with a 2 week delay on that front.
>>    
>>
>
>That means i have to find something else to do while the client waits
>because of ones laziness to do it themself.
>
>  
>
>>But for sure, 
>>after costs and time you're not coming out as much ahead of my $3 per 
>>board as you are thinking, and I'm getting PTH, mask, and not even 
>>having to make a board..
>>    
>>
>
>I'd still be in front compared to waiting for two weeks for a pcb and
>having the pcb vendor pay me $200. Anything more than simple PCBs usually
>need a second refinement, and it's far better to have the vendor make
>only the final design.
>
>
>  
>


  Great, guess what, your special need for immediate boards was already 
excepted in my original message with "Still ok if you just have to have 
an instant board, but that usually isn't so important vs a week or so.", 
you must have missed it.  So everything you've said doesn't have 
anything to do with what was being discussed in the first place, actual 
dollar cost of the boards, and no, you're not really ahead on that by 
much.  At $150ish for 5 8x10"s you can't be more than $150 ahead, and 
after taking out board costs etc it'll be notably less.  Plus your time 
not spent doing more productive things than making boards, or wasted if 
you like being lazy or don't have any work to do.  Plus no mask.  Plus 
you had the work of making the boards.  Just like I said in the original..

Alan

Alan King wrote:
> Russell Shaw wrote:
> 
>>Alan King wrote:
>>
>>>Russell Shaw wrote:
>>>
>>>>Even if they gave the boards to me for free, it's still much more expensive
>>>>than doing it myself. If i design a pcb, i can build it in an hour keeping
>>>>my same train of thought and get a result, and even iterate a new board if
>>>>needed. Getting them made outside means waiting atleast a week (usually two
>>>>or three unless you pay double).
>>>
>>> Hey, if you need that, then knock yourself out.  I can generally 
>>>remember exactly what I was doing a week or two later, and don't have 
>>>the slightest problem with a 2 week delay on that front.
>>
>>That means i have to find something else to do while the client waits
>>because of ones laziness to do it themself.
>>
>>>But for sure, 
>>>after costs and time you're not coming out as much ahead of my $3 per 
>>>board as you are thinking, and I'm getting PTH, mask, and not even 
>>>having to make a board..
>>
>>I'd still be in front compared to waiting for two weeks for a pcb and
>>having the pcb vendor pay me $200. Anything more than simple PCBs usually
>>need a second refinement, and it's far better to have the vendor make
>>only the final design.
> 
>   Great, guess what, your special need for immediate boards was already 
> excepted in my original message with "Still ok if you just have to have 
> an instant board, but that usually isn't so important vs a week or so.", 
> you must have missed it.  So everything you've said doesn't have 
> anything to do with what was being discussed in the first place, actual 
> dollar cost of the boards, and no, you're not really ahead on that by 
> much.  At $150ish for 5 8x10"s you can't be more than $150 ahead, and 
> after taking out board costs etc it'll be notably less.  Plus your time 
> not spent doing more productive things than making boards, or wasted if 
> you like being lazy or don't have any work to do.  Plus no mask.  Plus 
> you had the work of making the boards.  Just like I said in the original..

If i save 2 weeks (it's
usually more than that) on an item that's made in a product to a total
value of $100k/month, i've moved the income stream closer by a value of
$50k. That's the reason there's buyers for crappy little milling machines
for $20k. Hopefully someone on the group will come out with a better and
cheaper one. I'm going to make my own anyway.

So regardless of a pissy little $3 a board or $200, time is everything,
hence this group.

On Fri, 18 Nov 2005 01:40:03 +0100, Russell Shaw <rjshaw@...>  
wrote:

>
>
> Even if they gave the boards to me for free, it's still much more  
> expensive
>
> than doing it myself. If i design a pcb, i can build it in an hour  
> keeping
>
> my same train of thought and get a result, and even iterate a new board  
> if
>
> needed. Getting them made outside means waiting atleast a week (usually  
> two
>
> or three unless you pay double).


I'm with you there.
If they'd make them for free i would still make my own boards. I might let  
them make some of those that are non-urgent, but usually i want to have a  
board right when i finished the layout.
In a weeks time it is probably useless because i'd have found a couple of  
things to change or add in the meantime ;-).

Also, i do have experience with board houses, and the effort of preparing,  
checking/verifying, and sending the files plus placing an order is, for  
small quantities, far more than the work i have making my own. I know  
_everything_ about the design, i can omit many of the steps necessary to  
have another person make it.

ST

On Fri, 18 Nov 2005 03:57:10 +0100, Alan King <alan@...> wrote:

>
>
>
>   Hey, if you need that, then knock yourself out.  I can generally
>
> remember exactly what I was doing a week or two later, and don't have
>
> the slightest problem with a 2 week delay on that front..  But for sure,
>
> after costs and time you're not coming out as much ahead of my $3 per
>
> board as you are thinking, and I'm getting PTH, mask, and not even
>
> having to make a board..
>
>
> Alan
>


Alan, you must consider some of us don't charge for work on our own  
projects ;-)
I for one much prefer working for myself than working for someone else  
half the time.
I can sometimes not even remember what i was planning to do ten seconds  
ago, so.....

ST

In article <437C1364.5040001@...>,
   Russell Shaw <rjshaw@...> wrote:

> Haven't tried lexmark or other brands since. Things may be better now.
> Even with a slower drying printout, the resolution may be adequate
> depending on what you want. All you can do is try.

> Stay away from epson stylus 680 (a fairly old model, but newer than the
> stylus 400/440/460 series) because mechanically they're a piece of crap
> with unreliable paper pickup.

I've been using a Cannon S4500 with 3M film (couldn't easily find Cannon
film) and it seems OK to me.

derekhawkins wrote:
>>Did you use a single ballast and series connection for those tubes?
>>How many starters did it need?
> 
> Each "tube" is actually a separate lamp with its own ballast and 
> starter. The lamps were on sale at the time with each costing less 
> than a single UV tube. Here's a shot of the box with the lamps open 
> when only four were installed;
> 
> http://www.pbase.com/eldata/image/52324065

I got a 20W (equiv. to 100W filament) spiral-type black-light blue UV
compact flourescent lamp yesterday from Bunnings for $10. These would
work well in a conventional round reflector.

http://www.nelsonlamps.com.au/

Page 5 of:

http://www.nelsonlamps.com.au/products%20page/PDF%20Files/Lamps%20CFL%20Superior%205000hr.pdf


You could just mount a few light sockets in the bottom of a box (or one socket and
a reflector) for these and put a plate of glass and lid on top of the box.