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Photo Etching Method

2004-01-13 by mikezcnc

MikeZ_Photo_Etching in files section show my latest progress in Photo
Etching. In reality, the PCBs look perfect and very expensive.

Gentlemen, I appreciate your help in guiding me thru the maze of Heat
Transfer and Photoetching and I feel being very profficient and 100%
reliable in both methods.

In 30 minutes I can have a PCB etched and dry ready for soldering for
the cost of a PCB plus few pennies. I am not making it up.

Which conveniently brings me to the next question: where in US is the
cheapest source of PCBs? Mike

PS I despise the use of special paper at $1.50 or $1 a piece.

Soldermask?

2004-01-13 by Robert Ussery

Hi, Folks.
Are any of you using a DIY solder mask?
If so, how do you do it? I've been thinking I might try manually brushing
some thinned epoxy onto the board. Any ideas?

- Robert

Re: [Homebrew_PCBs] Photo Etching Method

2004-01-13 by Stefan Trethan

On Tue, 13 Jan 2004 19:05:48 -0000, mikezcnc <eemikez@...> wrote:

Show quoted textHide quoted text

> MikeZ_Photo_Etching in files section show my latest progress in Photo
> Etching. In reality, the PCBs look perfect and very expensive.
>
> Gentlemen, I appreciate your help in guiding me thru the maze of Heat
> Transfer and Photoetching and I feel being very profficient and 100%
> reliable in both methods.
>
> In 30 minutes I can have a PCB etched and dry ready for soldering for the
> cost of a PCB plus few pennies. I am not making it up.
>
> Which conveniently brings me to the next question: where in US is the
> cheapest source of PCBs? Mike
>
> PS I despise the use of special paper at $1.50 or $1 a piece.
>
>

good source for pcb material is ebay.
i have bought a maybe lifetime supply for ... not much..
the parcel was so heavy i had a hard time carrying it inside the house on
my own...
the shipping charges were not too high, if you choose the right company for
it....

st

Re: [Homebrew_PCBs] Soldermask?

2004-01-13 by Stefan Trethan

On Tue, 13 Jan 2004 12:41:06 -0700, Robert Ussery <uavscience@...>
wrote:

Show quoted textHide quoted text

> Hi, Folks.
> Are any of you using a DIY solder mask?
> If so, how do you do it? I've been thinking I might try manually brushing
> some thinned epoxy onto the board. Any ideas?
>
> - Robert
>
>

what do you need it for?
protection against oxydizing of copper tracks or for
masking off the copper while soldering?

I ask because the options you have then differ strong.

Stefan

RE: [Homebrew_PCBs] Soldermask?

2004-01-13 by Robert Ussery

I need surface mount solder masking. I've had some trouble with solder
bridges under the part because of running traces and vias underneath parts
on crowded boards.
Plus, if I mixed in some dye, it would look purty. :O)

- Robert

Show quoted textHide quoted text

>-----Original Message-----
>From: Stefan Trethan [mailto:stefan_trethan@...]

>what do you need it for?
>protection against oxydizing of copper tracks or for
>masking off the copper while soldering?
>
>I ask because the options you have then differ strong.
>
>Stefan

Re: Photo Etching Method

2004-01-13 by mikezcnc

Good idea Steve, but those are probably the bare PCBs and I am not
sure if spraying a positive coating is a reliable method. Mike

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

> On Tue, 13 Jan 2004 19:05:48 -0000, mikezcnc <eemikez@c...> wrote:
>
> > MikeZ_Photo_Etching in files section show my latest progress in

Photo

> > Etching. In reality, the PCBs look perfect and very expensive.
> >
> > Gentlemen, I appreciate your help in guiding me thru the maze of

Heat

> > Transfer and Photoetching and I feel being very profficient and

100%

> > reliable in both methods.
> >
> > In 30 minutes I can have a PCB etched and dry ready for soldering

for the

> > cost of a PCB plus few pennies. I am not making it up.
> >
> > Which conveniently brings me to the next question: where in US is

the

> > cheapest source of PCBs? Mike
> >
> > PS I despise the use of special paper at $1.50 or $1 a piece.
> >
> >
>
>
> good source for pcb material is ebay.
> i have bought a maybe lifetime supply for ... not much..
> the parcel was so heavy i had a hard time carrying it inside the

house on

> my own...
> the shipping charges were not too high, if you choose the right

company for

Show quoted textHide quoted text

> it....
>
> st

Re: [Homebrew_PCBs] Re: Photo Etching Method

2004-01-13 by Stefan Trethan

On Tue, 13 Jan 2004 19:57:18 -0000, mikezcnc <eemikez@...> wrote:

Show quoted textHide quoted text

> Good idea Steve, but those are probably the bare PCBs and I am not sure
> if spraying a positive coating is a reliable method. Mike
>
>
>

I was looking for blank material, using tt it is what i wanted...
I don't think you will find presensitized board that cheap (at ebay in
europe).

It may also be not so good to stock a huge amount of presensitzed, because
of shelf-life didn't consider this...

the material i got was pretty sure cut-offs from a board house.
(many stripes of ~150 * 400, but also a lot about a4 size)
i don't know how many board houses buy presensitized boards, but
this may be the reason why it is not so cheap.

ST

Re: [Homebrew_PCBs] Soldermask?

2004-01-13 by Stefan Trethan

On Tue, 13 Jan 2004 12:55:21 -0700, Robert Ussery <uavscience@...>
wrote:

Show quoted textHide quoted text

>
> I need surface mount solder masking. I've had some trouble with solder
> bridges under the part because of running traces and vias underneath
> parts
> on crowded boards.
> Plus, if I mixed in some dye, it would look purty. :O)
>
> - Robert
>

for this thers is some photoresist-like soldermask.
you spray it on, then expose it, and develop it.

I don't remember the manufacturer. i think there was one german company
but others may know where to get the stuff in your region.

how do you plan to apply your homemade epoxy mask without covering
the pads?

I always check if there is a short if i run more than one trace under a
1206 smd part.
never found one, but i rarely use smaller parts so no experience there.

ST

Re: Photo Etching Method

2004-01-13 by bsjoelund

> It may also be not so good to stock a huge amount of presensitzed,

because

Show quoted textHide quoted text

> of shelf-life didn't consider this...

Dont purchase presensitized material more than for 6 months usage,
keep material cool/dry/dark! I have had bad experience with
unsensitive material that was old!. Always use the same supplier so
you dont have to *recalibrate* your process, as long as they have the
same supplier/manufacturer.

Always, always use somekind of protection for eched boards. I use
Multicore PC52 spray, maybe this is no longer in production!?

Drilling after etching is the method for us homebrewers to use, as we
cannot cover up the pre-drilled holes and therefor ruin our pads in
etching. Always use sharp carbide drills.

Bengt

Re: [Homebrew_PCBs] Re: Photo Etching Method

2004-01-13 by Ted Huntington

bsjoelund wrote:

> Always use sharp carbide drills.
>

I found a good deal on carbide drill bits (although I still break them)
at http://www.store.yahoo.com/drillcity/

Ted

--
Ted Huntington
Programmer Analyst I
Main Library
University of California, Irvine
PO Box 19557
Irvine, CA 92623-9557

Phone Bus Off 949 824 8926
Phone MRC 949 824 1674
emesg: thunting@...
webpage: http://business.lib.uci.edu/webpages/ted.htm
"Stop violence, teach science."

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

Re: [Homebrew_PCBs] Re: Photo Etching Method

2004-01-13 by Stefan Trethan

On Tue, 13 Jan 2004 21:42:22 -0000, bsjoelund <tecnoconsult@...>
wrote:

Show quoted textHide quoted text

>> It may also be not so good to stock a huge amount of presensitzed,
> because
>> of shelf-life didn't consider this...
>
> Dont purchase presensitized material more than for 6 months usage, keep
> material cool/dry/dark! I have had bad experience with unsensitive
> material that was old!. Always use the same supplier so you dont have to
> *recalibrate* your process, as long as they have the same
> supplier/manufacturer.
>

well, my experience is that is is not that bad.
i got some boards for free a few years ago.
they were at least 3 years old (room temperature stored), the only thing i
could notice was
the black cover layer did come of a bit hard.
i used "pausklar" which is a light oil to solve it and rub it off.
but the board worked fine...

as said, i wouldn't stock presensitized board more than necessary.
and it is hard to get it cheap in large quantities anyways so there is no
reason...

st

Re: [Homebrew_PCBs] Re: Photo Etching Method

2004-01-13 by Alan King

Ted Huntington wrote:

>
> bsjoelund wrote:
>
>
>> Always use sharp carbide drills.
>>
>
>
> I found a good deal on carbide drill bits (although I still break them)
> at http://www.store.yahoo.com/drillcity/
>
> Ted
>

Those are good for new. (I think they were new..)

Check here for other deals:

http://www.tinkers-emporium.com/newpage31.htm
http://www.tinkers-emporium.com/hobby.htm

There's another guy on ebay:

http://cgi6.ebay.com/ws/eBayISAPI.dll?ViewSellersOtherItems&userid=toolsandtunes&include=0&since=-1&sort=3&rows=25

Toolsandtunes is his ID. Has a few rotobits right now, but if you check
later in the week for Monday ending he usually puts up a good list of drills.
Like 50 bit boxes for $5 or $10 sometimes depending on size. Resharps but I'm
way happy with what I got from both of these guys.

Got 50 .012 bits for the cost of getting 5 or 10 from the first link after I
found these guys.

Alan

Re: [Homebrew_PCBs] Re: Photo Etching Method

2004-01-13 by Stefan Trethan

On Tue, 13 Jan 2004 17:40:03 -0500, Alan King <alan@...> wrote:

Show quoted textHide quoted text

> Ted Huntington wrote:
>>
>> bsjoelund wrote:
>>
>>
>>> Always use sharp carbide drills.
>>>
>>
>>
>> I found a good deal on carbide drill bits (although I still break them)
>> at http://www.store.yahoo.com/drillcity/
>>
>> Ted
>>
>
> Those are good for new. (I think they were new..)
>
> Check here for other deals:
>

two guys at ebay germany (www.ebay.de) selling carbide bits.
you find them easily with "hartmetallbohrer".
(but import may not be interesting for most of you).

st

Re: [Homebrew_PCBs] Re: Photo Etching Method

2004-01-14 by dangermouse

I really appreciate all the drill bit links, everyone. Thanks.

-DM

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

Show quoted textHide quoted text

From: "Alan King" <alan@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Tuesday, January 13, 2004 5:40 PM
Subject: Re: [Homebrew_PCBs] Re: Photo Etching Method

> Ted Huntington wrote:
> >
> > bsjoelund wrote:
> >
> >
> >> Always use sharp carbide drills.
> >>
> >
> >
> > I found a good deal on carbide drill bits (although I still break them)
> > at http://www.store.yahoo.com/drillcity/
> >
> > Ted
> >
>
> Those are good for new. (I think they were new..)
>
> Check here for other deals:
>
> http://www.tinkers-emporium.com/newpage31.htm
> http://www.tinkers-emporium.com/hobby.htm
>
> There's another guy on ebay:
>
>
http://cgi6.ebay.com/ws/eBayISAPI.dll?ViewSellersOtherItems&userid=toolsandtunes&include=0&since=-1&sort=3&rows=25
>
> Toolsandtunes is his ID. Has a few rotobits right now, but if you
check
> later in the week for Monday ending he usually puts up a good list of
drills.
> Like 50 bit boxes for $5 or $10 sometimes depending on size. Resharps but
I'm
> way happy with what I got from both of these guys.
>
> Got 50 .012 bits for the cost of getting 5 or 10 from the first link
after I
> found these guys.
>
> Alan
>
>
> Be sure to visit the group home and check for new Bookmarks and files:
> http://groups.yahoo.com/group/Homebrew_PCBs
>
> Yahoo! Groups Links
>
> To visit your group on the web, go to:
> http://groups.yahoo.com/group/Homebrew_PCBs/
>
> To unsubscribe from this group, send an email to:
> Homebrew_PCBs-unsubscribe@yahoogroups.com
>
> Your use of Yahoo! Groups is subject to:
> http://docs.yahoo.com/info/terms/
>
>

RE: [Homebrew_PCBs] Soldermask?

2004-01-14 by Robert Ussery

>-----Original Message-----
>From: Stefan Trethan

>for this thers is some photoresist-like soldermask.
>you spray it on, then expose it, and develop it.

Cool... I'll have to look for this. Is this what the pros (boardhouses) use?

>how do you plan to apply your homemade epoxy mask without covering
>the pads?

Just carefully brush it on around them. Time consuming, but better than
solder bridges.

>I always check if there is a short if i run more than one trace under a
>1206 smd part.
>never found one, but i rarely use smaller parts so no experience there.

Mostly I've been having probs with some of the really small, weird stuff
like the ADXL202 accelerometer and ADXRS180 gyro. Standard dual-inline
surface mount stuff probably isn't as bad, but the ball-grid package of the
ADXRS180 is very short-prone, and the ADXL202's contacts run for some way
under the part and sloppy soldering can lead to excess solder wicking
underneath and causing bridges.

- Robert

Re: Photo Etching Method

2004-01-14 by Ben H. Lanmon

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

> Which conveniently brings me to the next question: where in US is

the

Show quoted textHide quoted text

> cheapest source of PCBs? Mike

I buy M. G. Chemicals products. I use their 600 series pos.
presensitized boards. They are not the cheapest. I buy the M.G.
Chemicals thru Circuit Specialists @ www.webtronics.com They also
have some other brand pos. presensitized boards that are cheaper but
I have not tried them out yet. Not many places selling the pos.
presensitized boards now days, or neg. boards for that matter now
that Kepro has gone out of business. Never tried ebay, they seem to
be bare boards and normally smaller sized than I want.

Never had good results doing the pos. resist myself and was a big
hassle to do it. I only do the pos. photo method myself using
presensitized boards, get much better results than I did with toner
transfer and once you are setup to do it really does not take that
long. You do need a good inkjet to print transparencies, I
currently use a HP CP 1700 with good results on HP transparencies.

The only thing I have a complaint on the M.G. Chemicals boards is
that sometimes they are cut sized to mm and sometimes to inches so I
try to figure on them being sized to the mm as they are slightly
smaller.

Ben

Re: Photo Etching Method

2004-01-14 by Ben H. Lanmon

If you are looking for bare boards Mouser www.mouser.com has some
4"x 6" 8" x 10" and 12" x 12". These are a FR-4 composite. That
will give you one more place to look at.

I think G C Electonics makes presensitized boards but finding a
dist. that stocks them may not be easy, atleast I did not have much
luck on it.

Ben

Re: [Homebrew_PCBs] Soldermask?

2004-01-14 by Stefan Trethan

On Tue, 13 Jan 2004 18:07:06 -0700, Robert Ussery <uavscience@...>
wrote:

>
>
>> -----Original Message-----
>> From: Stefan Trethan
>
>> for this thers is some photoresist-like soldermask.
>> you spray it on, then expose it, and develop it.
>
> Cool... I'll have to look for this. Is this what the pros (boardhouses)
> use?
>

No board hoses use silk screen for that in 99% of the cases i think.
the screen can be rather coarse, the resolution requirement is not that
high.
on some boards you can make out the pattern of the mash if you look close
at the soldermask.

>> how do you plan to apply your homemade epoxy mask without covering
>> the pads?
>
> Just carefully brush it on around them. Time consuming, but better than
> solder bridges.

i assumed that.. a stencil, maybe cut with a vynyl cutter, may be a option
if you need more boards with the same pattern..

then it may be best to just apply it where really needed.
may even look better than if you try to paint the whole board..

try clear laquer, any should work. high-temperature may be best...

>
>> I always check if there is a short if i run more than one trace under a
>> 1206 smd part.
>> never found one, but i rarely use smaller parts so no experience there.
>
> Mostly I've been having probs with some of the really small, weird stuff
> like the ADXL202 accelerometer and ADXRS180 gyro. Standard dual-inline
> surface mount stuff probably isn't as bad, but the ball-grid package of
> the
> ADXRS180 is very short-prone, and the ADXL202's contacts run for some way
> under the part and sloppy soldering can lead to excess solder wicking
> underneath and causing bridges.

i see...
I suggest trying laquer on the dangerous spots, maybe you can even use a
laquer-pen.

you could also try to make a stencil for the "special" parts you mentioned.
take thin sheet metal, it can be etched like a pcb.

then just position the stencil exactly and spray on some laquer.

ST

>
> - Robert
>
>