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Adapting solder resist application to TT method

Adapting solder resist application to TT method

2014-10-09 by alan00463@...

I ran across a couple of youtube videos showing a 3-ply green film being applied to a board to make the solder resist layer:

http://www.youtube.com/watch?v=y_LJ1W3DolM

http://www.youtube.com/watch?v=B0Syj4awcc8

I use the toner transfer method to etch 0.0625" thick copper boards.
Am wondering if I could use this stuff on my boards if I am not set up for photoetching.

Does anybody know if (1) this 3-ply green film is sold in the USA and if yes, what it is called and by whom?

(2) Can I still use this stuff on my boards if I am doing TT rather than photo-etching for laying out my pads/traces?    If yes, how ?

If I am going down the wrong path, please say so.

Thanks,

Allan

Re: Adapting solder resist application to TT method

2014-10-09 by chris@...

I haven't used it, but I'm working on setting up an exposure system so I can.


I've only seen the film on eBay. Dry Film Solder Mask Roll of 12 in x 42.5 in (bigger lenght by request)


I think you'd have to photo etch it, but you could do that by just printing your mask on velum or transparency film. From what I understand it's a 2 step cure. The first exposure just cures it enough that you can wash away the resist on your pads, and the second cure kind of bakes it on.


It would certainly hold up to reflow temperatures. Making a mask to apply solder paste for SMD components is probably the more challenging part.

Dry Film Solder Mask Roll of 12 in x 42.5 in (bigger len...
US $25.00 New in Business & Industrial, Electrical & Test Equipment, Electronic Components
View on www.ebay.com
Preview by Yahoo

 

Re: [Homebrew_PCBs] Adapting solder resist application to TT method

2014-10-10 by Harvey White

On 09 Oct 2014 14:20:09 -0700, you wrote:

>I ran across a couple of youtube videos showing a 3-ply green film being applied to a board to make the solder resist layer:
>
>http://www.youtube.com/watch?v=y_LJ1W3DolM
>
>http://www.youtube.com/watch?v=B0Syj4awcc8
>
>I use the toner transfer method to etch 0.0625" thick copper boards.
>Am wondering if I could use this stuff on my boards if I am not set up for photoetching.

This is most likely a UV cure film that's photosensitive, and needs to
be developed. You laminate it on, expose it, develop it to get the
unwanted parts off, then likely bake it to cure it.
>
>Does anybody know if (1) this 3-ply green film is sold in the USA and if yes, what it is called and by whom?
>
I do toner transfer as well, but no, I don't.

>(2) Can I still use this stuff on my boards if I am doing TT rather than photo-etching for laying out my pads/traces? If yes, how ?

Nope, not a chance as I understand it. If you did laminate your
board, how are you planning to get the little holes in it for the
pads? If you cure the film, then if it covers everything and resists
solder, then that doesn't help, not that I can see.

If you were to use the green laminate film specifically designed to
strengthen the toner on a PC board, then you'd need a layer of toner
that completely covered the board except for the pads, and that toner
and green layer would have to be solder heat resistant (never tried to
see if it is).

If someone has done this, I'd be interested in how, and using what
materials.....

Harvey

>
>If I am going down the wrong path, please say so.
>
>Thanks,
>
>Allan

Re: Adapting solder resist application to TT method

2014-10-12 by alan00463@...

Suspecting nail polish might come in green, in blue, and in purple, I googled "nail polish as solder mask".    I found one bloke who  claimed to have used enamel nail polish as a homebrew PCB solder mask.    He said to use enamel, but not acrylic.

I had nail polish leftover from another project.    So I looked and found neither word printed on the bottle.    I tried it anyway.     I coated it on the edge of an old PCB.   When it was dry, I verified the polish is an electrical insulator.   

I repeated the experiment with a new green bottle of nail polish with "enamel" on the label.      It looked great the next morning.    I verified with my multimeter that it is also an insulator.  

However, I was able to scratch away both types of nail polish with my fingernail, so that would not make a good soldermask.    I will try overlaying the nail polish with clear coats -- clear nail polish, lacquer, polyurethane ? -- and see if anything works.     If I can get something to work, I'll report my combination.   Now that cold weather has arrived in the lower 48, I am going to try to avoid any liquid that is sprayed.

I also ran across a dry film solder mask vendor http://www.soldermask.com/dfsm.html
but haven't yet explored how this works.

Re: Adapting solder resist application to TT method

2014-10-13 by fred27murphy@...

I've used the dry film solder mask and think it's great stuff. I found it from a European supplier as Dynamask 5000. You'll need a laminator, the same UV exposure as you'd use for PCBs (if you make them that way) and some sodium carbonate to develop it.

I ordered a fair bit - probably more than I need. If anyone in the UK would like to try it out then let me know and I'll send you some.

Re: [Homebrew_PCBs] Re: Adapting solder resist application to TT method

2014-10-14 by James



On Mon, Oct 13, 2014 at 4:04 AM, alan00463@... [Homebrew_PCBs] <Homebrew_PCBs@yahoogroups.com> wrote:
 

Suspecting nail polish might come in green, in blue, and in purple, I googled "nail polish as solder mask".    I found one bloke who  claimed to have used enamel nail polish as a homebrew PCB solder mask.    He said to use enamel, but not acrylic.

 Nail polish doesn't sound particularly likely. 

Here's the 3 best ways for soldermask at home in no particular order...

1.  Vitrea 160 paint from a good art supply store (important, specifically Vitrea 160, other similar products do not work).  Use toner transfer to mask off the pads, spray a slightly thinned vitrea 160 (I thin with meths, but this probably makes the toner-cleanup more difficult at the end,water might be better, but it's trickier to spray).  Allow to dry (don't worry about waiting 24 hours, just until it's touch dry).  Bake for about 45 minutes, at 180 degrees C (well, 180 on my oven, your milage may vary).  Use acetone and a bit of elbow grease to remove the toner.  The vitrea is very strong, electrically insulating, and heat resistant, solder doesn't stick really to it as long as there is flux.  Advantage: cheap and readily available from art shops in a wide selection of colours.  Disadvantage: you need to spray it (airbrush) it on, and do toner transfer to mask the pads, and it's not always easy to clean off the toner.

2. Dry Film Soldermask (Dynamask).  As discussed already in this thread.  Advantage: easy to apply.  Disadvantage: expensive and hard to get.  Alternative - use dry film resist instead, bake it to further harden, not that strong to abrasion, but easy and cheap to obtain, electrically insulative.

3. Liquid Photoimagable Soldermask (UV cure paint/ink) from ebay etc.  There have been previous discussions about this, a fellow Kiwi has done some further experimentation, in summary: sprat it on, he uses a 0.8mm gravity gun, thinned with acetone just enough to spray it, dry at 105 degrees C for 30-5minutes (temperature is fairly critical), the paint doesn't really "dry", more develops a "skin", align artwork carefully and expose (quite a long exposure, 15 minutes with 30w of uv bulbs), wipe off the uncured paint with acetone (I woudl follow that up with exposing without mask for another period of time to fully cure).  Advantage: cheap and easy to get from eBay.  Disadvantage: it takes a lot of practice.

_,_._,___

RE: [Homebrew_PCBs] Re: Adapting solder resist application to TT method

2014-10-14 by Dave G4UGM

I have used Nail “Polish” as etch resist. As it It is called Varnish in the UK, I assumed it was some kind of polyurethane paint like stuff.   It is very resistant to etchant, but it is too thick to use for anything delicate. I don’t think it would make a good solder mask. Actually it might be worse than I thought! This page:-

 

http://chemistry.about.com/od/chemicalcomposition/a/Nail-Polish-Chemistry.htm

 

and this

 

http://en.wikipedia.org/wiki/Nail_polish

 

 

Implies the layer left behind is nitrocellulose, which I would guess is flammable…..

 

Dave

G4UGM

 

From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
Sent: 14 October 2014 01:29
To: Homebrew PCBs
Subject: Re: [Homebrew_PCBs] Re: Adapting solder resist application to TT method

 




 

 

On Mon, Oct 13, 2014 at 4:04 AM, alan00463@... [Homebrew_PCBs] <Homebrew_PCBs@yahoogroups.com> wrote:

 

Suspecting nail polish might come in green, in blue, and in purple, I googled "nail polish as solder mask".    I found one bloke who  claimed to have used enamel nail polish as a homebrew PCB solder mask.    He said to use enamel, but not acrylic.

 Nail polish doesn't sound particularly likely. 

 

Here's the 3 best ways for soldermask at home in no particular order...

 

1.  Vitrea 160 paint from a good art supply store (important, specifically Vitrea 160, other similar products do not work).  Use toner transfer to mask off the pads, spray a slightly thinned vitrea 160 (I thin with meths, but this probably makes the toner-cleanup more difficult at the end,water might be better, but it's trickier to spray).  Allow to dry (don't worry about waiting 24 hours, just until it's touch dry).  Bake for about 45 minutes, at 180 degrees C (well, 180 on my oven, your milage may vary).  Use acetone and a bit of elbow grease to remove the toner.  The vitrea is very strong, electrically insulating, and heat resistant, solder doesn't stick really to it as long as there is flux.  Advantage: cheap and readily available from art shops in a wide selection of colours.  Disadvantage: you need to spray it (airbrush) it on, and do toner transfer to mask the pads, and it's not always easy to clean off the toner.

 

2. Dry Film Soldermask (Dynamask).  As discussed already in this thread.  Advantage: easy to apply.  Disadvantage: expensive and hard to get.  Alternative - use dry film resist instead, bake it to further harden, not that strong to abrasion, but easy and cheap to obtain, electrically insulative.

 

3. Liquid Photoimagable Soldermask (UV cure paint/ink) from ebay etc.  There have been previous discussions about this, a fellow Kiwi has done some further experimentation, in summary: sprat it on, he uses a 0.8mm gravity gun, thinned with acetone just enough to spray it, dry at 105 degrees C for 30-5minutes (temperature is fairly critical), the paint doesn't really "dry", more develops a "skin", align artwork carefully and expose (quite a long exposure, 15 minutes with 30w of uv bulbs), wipe off the uncured paint with acetone (I woudl follow that up with exposing without mask for another period of time to fully cure).  Advantage: cheap and easy to get from eBay.  Disadvantage: it takes a lot of practice.

 

_,_._,___

 




Re: Adapting solder resist application to TT method

2014-10-18 by alienrelics@...

Please don't start a new topic by replying to an existing topic. Even if you change the subject line and delete the old messages, Yahoogroups posts it as part of the old topic.

Steve Greenfield AE7HD