Homebrew PCBs

I was wondering if people use the toner transfer method with the clear 
laser print transparency sheets??  I like the ability to see through 
the film for ligning up dual layer boards with a few key drill holes 
for alignment.  Simply line up the holes with the pads on the clear 
sheet and iron on.  I have tried it with copier transparency sheets 
and got okay results but never tried the laser printer sheets.  My 
guess is they can take much higher heat than the ones for copiers.  I 
wondered if one sheet could be cleaned with Acetone and reused a few 
times??

Anyone have any thoughts or comments?

I tried it, but can't get good density on OHP.
Sb. reported good results if i remember correctly, beeing able to peel the  
plastic right off.

BUT, if you look at the silicone paper discussion a while back it is much  
what you want.
Basically you spread some RTV silicone, high temperature variety, with a  
squeegee on a piece of ordinary paper, let cure.
This will allow you to make nice black transfers with no soaking etc. (can  
just be pulled off).

I had no opportunity to finish my development of this method, i'm quite  
sure it can be used for transferring resist, but so far i have some toner  
density/pinhole problems with it. (the etchant goes "through" it in  
places). When using paper this does not happen (not sure if it is the  
coating or something else). Anyway, the silicone paper transferred stuff  
looks fantastic and i use it for legend and panels and stuff. At some  
point i'll look into it again for resist. The paper can be re-used, since  
all the toner comes off but it can also be cleaned with acetone.


ST


On Fri, 18 Nov 2005 23:09:42 +0100, matt clement <buckeyes1997@...>  
wrote:

> I was wondering if people use the toner transfer method with the clear
>
> laser print transparency sheets??  I like the ability to see through
>
> the film for ligning up dual layer boards with a few key drill holes
>
> for alignment.  Simply line up the holes with the pads on the clear
>
> sheet and iron on.  I have tried it with copier transparency sheets
>
> and got okay results but never tried the laser printer sheets.  My
>
> guess is they can take much higher heat than the ones for copiers.  I
>
> wondered if one sheet could be cleaned with Acetone and reused a few
>
> times??
>
>
> Anyone have any thoughts or comments?
>
>

i dont see how you would get the rtv silicone spread perfectly even 
without any peaks that would cause it to not transfer the toner 
correctly.  

i started thinking about soaking a regular piece of paper in 
vegetable oil til its almost clear (saturated) and then run it 
through the printer.  the toner will still adhear to the paper but 
the oil should allow it to release much easier than dry paper.  if i 
get time this weekend ill try it and report back.

matt



--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan" 
<stefan_trethan@g...> wrote:
>
> I tried it, but can't get good density on OHP.
> Sb. reported good results if i remember correctly, beeing able to 
peel the  
> plastic right off.
> 
> BUT, if you look at the silicone paper discussion a while back it 
is much  
> what you want.
> Basically you spread some RTV silicone, high temperature variety, 
with a  
> squeegee on a piece of ordinary paper, let cure.
> This will allow you to make nice black transfers with no soaking 
etc. (can  
> just be pulled off).
> 
> I had no opportunity to finish my development of this method, i'm 
quite  
> sure it can be used for transferring resist, but so far i have 
some toner  
> density/pinhole problems with it. (the etchant goes "through" it 
in  
> places). When using paper this does not happen (not sure if it is 
the  
> coating or something else). Anyway, the silicone paper transferred 
stuff  
> looks fantastic and i use it for legend and panels and stuff. At 
some  
> point i'll look into it again for resist. The paper can be re-
used, since  
> all the toner comes off but it can also be cleaned with acetone.
> 
> 
> ST
> 
> 
> On Fri, 18 Nov 2005 23:09:42 +0100, matt clement 
<buckeyes1997@y...>  
> wrote:
> 
> > I was wondering if people use the toner transfer method with the 
clear
> >
> > laser print transparency sheets??  I like the ability to see 
through
> >
> > the film for ligning up dual layer boards with a few key drill 
holes
> >
> > for alignment.  Simply line up the holes with the pads on the 
clear
> >
> > sheet and iron on.  I have tried it with copier transparency 
sheets
> >
> > and got okay results but never tried the laser printer sheets.  
My
> >
> > guess is they can take much higher heat than the ones for 
copiers.  I
> >
> > wondered if one sheet could be cleaned with Acetone and reused a 
few

> >
> > times??
> >
> >
> > Anyone have any thoughts or comments?
> >
> >
>

On Fri, 18 Nov 2005 23:49:55 +0100, matt clement <buckeyes1997@...>  
wrote:

> i dont see how you would get the rtv silicone spread perfectly even
>
> without any peaks that would cause it to not transfer the toner
>
> correctly.

It needn't be spread perfectly at all. with a wide squeegee you can spread  
it nicely if you place the paper on something flat like a mirror. I  
usually spread it as thin as it will go (scrape), it is enough to fill all  
the holes and fibers in the paper to make it release the toner easily. But  
color darkness will allow you to easily spread it to any thickness you  
like, evenly. Try it you'll see.


> i started thinking about soaking a regular piece of paper in
>
> vegetable oil til its almost clear (saturated) and then run it
>
> through the printer.  the toner will still adhear to the paper but
>
> the oil should allow it to release much easier than dry paper.  if i
>
> get time this weekend ill try it and report back.
>

What a mess! how will you clean the printer?
I see several problems:
Either the toner will fuse just the same, or it will slide off too easily  
like on baking paper.
The oil will boil in the fuser, causing it to be smeared all over the  
toner, making it impossible to adhere the toner to the PCB.

I'm all for experimenting, but i'll eat that oil-saturated piece of paper  
if that works ;-)
Anyway, if you try make sure to tell the tale.

ST

matt clement wrote:

>i dont see how you would get the rtv silicone spread perfectly even 
>without any peaks that would cause it to not transfer the toner 
>correctly.  
>  
>
http://i2.peapod.com/c/4V/4VZSC.jpg


  Why make silicone paper?  :)

Alan

On Sat, 19 Nov 2005 01:05:51 +0100, Alan King <alan@...> wrote:

> matt clement wrote:
>
>
>> i dont see how you would get the rtv silicone spread perfectly even
>
>> without any peaks that would cause it to not transfer the toner
>
>> correctly.
>
>>
>
>>
>
> http://i2.peapod.com/c/4V/4VZSC.jpg
>
>
>
>   Why make silicone paper?
>
>
> Alan
>


Because you mightn't get what you want any other way.
I haven't got any reynolds paper here, but all baking papers i tried were  
way too slippery for TT.
The thing about the silicone coated paper is it's not slippery, it's kind  
of rubbery sticky, but still doesn't allow the paper to fuse.

There are silicone baking sheets here, but they are way too thick to even  
try.

ST

okay
I figured the printer would get oily with the oil method, but didnt 
think it would leave the printer too bad off.  I am going to pick up 
a tube of RTV silicone today (high heat) and try getting a window 
cleaning squeegy to get it on the paper.  i assume you only do one 
side right?  Am I looking to get a layer as thick as a "notecard" or 
am I trying to get it as thin as as possible?  I would only worry 
about getting it too thin in some spots.  I just havent figured out 
how to get it to be thin and yet perfectly smooth.  maybe laying 
another piece of glass on top and add pressure to get all the air 
bubbles out until dry?  IS RTV anerobic?


--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan" 
<stefan_trethan@g...> wrote:
>
> On Sat, 19 Nov 2005 01:05:51 +0100, Alan King <alan@n...> wrote:
> 
> > matt clement wrote:
> >
> >
> >> i dont see how you would get the rtv silicone spread perfectly 
even
> >
> >> without any peaks that would cause it to not transfer the toner
> >
> >> correctly.
> >
> >>
> >
> >>
> >
> > http://i2.peapod.com/c/4V/4VZSC.jpg
> >
> >
> >
> >   Why make silicone paper?
> >
> >
> > Alan
> >
> 
> 
> Because you mightn't get what you want any other way.
> I haven't got any reynolds paper here, but all baking papers i 
tried were  
> way too slippery for TT.
> The thing about the silicone coated paper is it's not slippery, 
it's kind  
> of rubbery sticky, but still doesn't allow the paper to fuse.
> 
> There are silicone baking sheets here, but they are way too thick 
to even  

> try.
> 
> ST
>

lol try getting it off the glass afterwards!

I once use some silicone to temporary fasten two plastic bats to the 
fron of the cab I was driving, they lasted about half halloween night 
before the wind at high speed had them fly away, but I _never_ got the 
silicone lump off the bonnet!

> how to get it to be thin and yet perfectly smooth.  maybe laying 
> another piece of glass on top and add pressure to get all the air 
> bubbles out until dry?  IS RTV anerobic?

On Sat, 19 Nov 2005 16:28:24 +0100, matt clement <buckeyes1997@...>  
wrote:

> okay
>
> I figured the printer would get oily with the oil method, but didnt
>
> think it would leave the printer too bad off.  I am going to pick up
>
> a tube of RTV silicone today (high heat) and try getting a window
>
> cleaning squeegy to get it on the paper.  i assume you only do one
>
> side right?  Am I looking to get a layer as thick as a "notecard" or
>
> am I trying to get it as thin as as possible?  I would only worry
>
> about getting it too thin in some spots.  I just havent figured out
>
> how to get it to be thin and yet perfectly smooth.  maybe laying
>
> another piece of glass on top and add pressure to get all the air
>
> bubbles out until dry?  IS RTV anerobic?


Don't use a window sqeegee, use a metal one. i dunno what it is normally  
used for but my tools store has them in all widths, i use a 20cm wide one.  
It's made of about 0.5mm thick steel and has a wooden handle.

You can scrape right down to the paper with as much pressure as you can  
without ripping it, holding the sqeegee almost vertical. This will still  
allow easy release, if you peel while the PCB is still warm. If you make a  
thicker layer (so that the suface is just glossy) you can peel cold  
without ripping the toner off, but it is hard to see through if you have  
red silicone. Using even more silicone would seem bad to me since thicker  
material gets less toner density and you don't really gain anything.

ST

On Sat, 19 Nov 2005 17:32:25 +0100, Lez <lez.briddon@...> wrote:

> lol try getting it off the glass afterwards!
>
>
> I once use some silicone to temporary fasten two plastic bats to the
>
> fron of the cab I was driving, they lasted about half halloween night
>
> before the wind at high speed had them fly away, but I _never_ got the
>
> silicone lump off the bonnet!


LOL, that would really be impossible. As far as i know a blade is the only  
way, that ain't no good for the paint.
There are some removers/cleaners, but none seem to work well on the cured  
product. I reckon if one _really_ removes it you would have ended up with  
a hole in the bonnet, or some paint missing at the very least.

However, there's a trick, if you want to mold silicone against something  
lightly grease the surface. I used that to make the seal on my last  
etching tank. Doesn't stick of course.

For your bonnet, you should have used those removeable mounts for skies  
and other stuff you can put on the roof ;-)

But back on topic, to clean up after coating paper, i let it harden on the  
squeegee and mirror, and simply pull it off the squeegee and use the same  
to scrape it off the glass. Works well.

ST

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

From: "Stefan Trethan" <stefan_trethan@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Saturday, November 19, 2005 11:20 AM
Subject: Re: [Homebrew_PCBs] Re: laser printer transparency film any good?


> On Sat, 19 Nov 2005 16:28:24 +0100, matt clement <buckeyes1997@...>
> wrote:
>
>> okay
>>
>> I figured the printer would get oily with the oil method, but didnt
>>
>> think it would leave the printer too bad off.  I am going to pick up
>>
>> a tube of RTV silicone today (high heat) and try getting a window
>>
>> cleaning squeegy to get it on the paper.  i assume you only do one
>>
>> side right?  Am I looking to get a layer as thick as a "notecard" or
>>
>> am I trying to get it as thin as as possible?  I would only worry
>>
>> about getting it too thin in some spots.  I just havent figured out
>>
>> how to get it to be thin and yet perfectly smooth.  maybe laying
>>
>> another piece of glass on top and add pressure to get all the air
>>
>> bubbles out until dry?  IS RTV anerobic?
>
>
> Don't use a window sqeegee, use a metal one. i dunno what it is normally
> used for but my tools store has them in all widths, i use a 20cm wide one.
> It's made of about 0.5mm thick steel and has a wooden handle.

Paint and wallpaper. That should narrow down which part of the store to look 
in.

ST,

Sounds like a drywall "knife"/ trowel...

Ballendo

--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan" 
<stefan_trethan@g...> wrote:
> Don't use a window sqeegee, use a metal one. i dunno what it is 
normally  
> used for but my tools store has them in all widths, i use a 20cm 
wide one.  
> It's made of about 0.5mm thick steel and has a wooden handle.

Not to hijack this thread (which has wandered away from the original 
post...and onto RTV silicon impregnated papers and direct-to-copper 
printing)...but to address the original posters question:

Yes, laser transparency sheets work great for TT.  I have used the 3M 
brand.  I personally was never able to get any of these papers (or 
glossy magazine pages) to work for me using TT.  Of course, I never 
bought a laminator...so I was probably not using an even enough heat 
distribution with my naive clothes iron based approach.

But I will testify that viewgraph transparencies worked GREAT.  The 
transparency just peels off...and leaves ALL the toner behind. The 
etched traces looked pretty good. 

I stopped using this technique for completely unrelated reasons.  It 
should work well for others. 

I did have to be a little careful about ironing the board TOO long. 
Because then the toner would smear a little. I am guessing the toner 
doesn't really bind that well to the plastic, versus paper.

Jim

P.S.  BTW, I have stopped using TT, myself.  I am putting together a 
small mill to mill isolation traces.  The reason I want to do things 
this way...is that I am just a hardware hacker. I build my designs a 
susbsystem at a time...and so...I need to be able to continue adding 
traces onto an existing populated board.  That's a little hard to do 
using ANY chemical milling technique.  (The parts would be destroyed 
by the wet chemistry involved.)

Yes, I want to use PCBs even for one-off experimental projects.  It 
seems like too cool a way to go - to not try it out

--- In Homebrew_PCBs@yahoogroups.com, "matt clement" 
<buckeyes1997@y...> wrote:
>
> I was wondering if people use the toner transfer method with the 
clear 
> laser print transparency sheets??  I like the ability to see through 
> the film for ligning up dual layer boards with a few key drill holes 
> for alignment.  Simply line up the holes with the pads on the clear 
> sheet and iron on.  I have tried it with copier transparency sheets 
> and got okay results but never tried the laser printer sheets.  My 
> guess is they can take much higher heat than the ones for copiers.  
I 

> wondered if one sheet could be cleaned with Acetone and reused a few 
> times??
> 
> Anyone have any thoughts or comments?
>

On Mon, 21 Nov 2005 22:38:45 +0100, jzmuda2000 <hwhacker@...> wrote:

>
> P.S.  BTW, I have stopped using TT, myself.  I am putting together a
>
> small mill to mill isolation traces.  The reason I want to do things
>
> this way...is that I am just a hardware hacker. I build my designs a
>
> susbsystem at a time...and so...I need to be able to continue adding
>
> traces onto an existing populated board.  That's a little hard to do
>
> using ANY chemical milling technique.  (The parts would be destroyed
>
> by the wet chemistry involved.)
>
>
> Yes, I want to use PCBs even for one-off experimental projects.  It
>
> seems like too cool a way to go - to not try it out


Would that work? i mean where do you join the new traces to?

I've trouble enough drilling additional holes in a populated board, you  
are certainly a brave man ;-)

ST

I was also curious how that would go. OK, I made a circuit, the PCB 
is all milled and drilled, I populated the PCB and it all works but 
not to well. Turns out I need to add anotehr IC because... whatever. 
I take that PCB under the dremel of my fancy PCB mill and position it 
wher I placed a dot. OK< ready, glasses on, let the V bit do it's 
expanding job!

Wow, that is a certainly a way to live the life!  An alternative 
would be to quickly TT another PCB, drill it with that PCB drill, 
just because I can, stuff it and put it on a standoff on the first 
PCB. The second method seems to be simpler FOR ME. Mike

Mike

--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan" 
<stefan_trethan@g...> wrote:
>
> On Mon, 21 Nov 2005 22:38:45 +0100, jzmuda2000 <hwhacker@g...> 
wrote:
> 
> >
> > P.S.  BTW, I have stopped using TT, myself.  I am putting 
together a
> >
> > small mill to mill isolation traces.  The reason I want to do 
things
> >
> > this way...is that I am just a hardware hacker. I build my 
designs a
> >
> > susbsystem at a time...and so...I need to be able to continue 
adding
> >
> > traces onto an existing populated board.  That's a little hard to 
do
> >
> > using ANY chemical milling technique.  (The parts would be 
destroyed
> >
> > by the wet chemistry involved.)
> >
> >
> > Yes, I want to use PCBs even for one-off experimental projects.  
It
> >
> > seems like too cool a way to go - to not try it out
> 
> 
> Would that work? i mean where do you join the new traces to?
> 
> I've trouble enough drilling additional holes in a populated board, 
you  

> are certainly a brave man ;-)
> 
> ST
>

On Tue, 22 Nov 2005 02:28:36 +0100, mikezcnc <eemikez@...> wrote:

> I was also curious how that would go. OK, I made a circuit, the PCB
>
> is all milled and drilled, I populated the PCB and it all works but
>
> not to well. Turns out I need to add anotehr IC because... whatever.
>
> I take that PCB under the dremel of my fancy PCB mill and position it
>
> wher I placed a dot. OK< ready, glasses on, let the V bit do it's
>
> expanding job!
>
>
> Wow, that is a certainly a way to live the life!  An alternative
>
> would be to quickly TT another PCB, drill it with that PCB drill,
>
> just because I can, stuff it and put it on a standoff on the first
>
> PCB. The second method seems to be simpler FOR ME. Mike
>
>
> Mike


Yes, but what i don't get is how you add something. How do you manage to  
get the traces you need to the right signals, and how do you manage to  
contact them? i mean when one section is finished normally all around it  
will be a isolated gap?

ST