Synth-DIY Yahoo! Groups Archives

Thread

First Negative developement Brd

2016-08-19 by kbyrne10@...

I finally have all the supplies that I need and need a question answered.

Supplies

Scotch Laminator

Office depot Black and white copier transparencies. Two copies of each experiment circuit.

Dry film bought in China

PH up bought on E-Bay

Eagle to Gimp negative

Dakta light bulb approx 12 in above frame.

Question? How long do I turn on light bulb for first experiment in developeing board.

If it fails to develope properly how much time do I add for next experiment?

What is correct procedure for this experiment to learn this aspect properly?

Re: [Homebrew_PCBs] First Negative developement Brd

2016-08-19 by Malcolm Parker-Lisberg

Do a test exposure, cover the negative, on a piece of scrap board, and expose a strip for 10 seconds say, move card along to reveal an extra strip, expose and so on.  Develope and chose time that give best result.  In the example the first strip would be exposed for 20 secs and the second strip ten.  Depending on the lamp, wavelength sensity of film and height, the time requie3d can vary considerably.

Write the times on the card as it is easy to forget how many you have done.

Malcolm

I don't suffer from insanity I enjoy it! 
Mene, mene, tekel, upharsin 
The writing is on the wall. 
Ha-ktovet al ha-kir

--------------------------------------------
On Fri, 8/19/16, kbyrne10@... [Homebrew_PCBs] <Homebrew_PCBs@yahoogroups.com> wrote:

Show quoted textHide quoted text

 Subject: [Homebrew_PCBs] First Negative developement Brd
 To: Homebrew_PCBs@yahoogroups.com
 Date: Friday, August 19, 2016, 1:36 PM
 
 
  
 
 
 
   
 
 
     
       
       
       I finally have all the supplies that I
 need and need a question
 answered.SuppliesScotch
 LaminatorOffice depot Black and white
 copier transparencies. Two copies of each experiment
 circuit.Dry film bought in
 ChinaPH up bought on
 E-BayEagle to Gimp
 negativeDakta light bulb approx 12 in
 above frame.Question? How long do I turn
 on light bulb for first experiment in developeing
 board.If it fails to develope properly
 how much time do I add for next
 experiment?What is correct procedure for
 this experiment to learn this aspect properly?
 
     
      
 
     
     
 
 
 
 #yiv3949153176 #yiv3949153176 --

Re: [Homebrew_PCBs] First Negative developement Brd

2016-08-19 by Malcolm Parker-Lisberg

Forgot to add, cover glass can absorbe the UV required by the film, so you may need to experiment with that also..

Malcolm

I don't suffer from insanity I enjoy it! 
Mene, mene, tekel, upharsin 
The writing is on the wall. 
Ha-ktovet al ha-kir

--------------------------------------------
On Fri, 8/19/16, kbyrne10@... [Homebrew_PCBs] <Homebrew_PCBs@yahoogroups.com> wrote:

Show quoted textHide quoted text

 Subject: [Homebrew_PCBs] First Negative developement Brd
 To: Homebrew_PCBs@yahoogroups.com
 Date: Friday, August 19, 2016, 1:36 PM
 
 
  
 
 
 
   
 
 
     
       
       
       I finally have all the supplies that I
 need and need a question
 answered.SuppliesScotch
 LaminatorOffice depot Black and white
 copier transparencies. Two copies of each experiment
 circuit.Dry film bought in
 ChinaPH up bought on
 E-BayEagle to Gimp
 negativeDakta light bulb approx 12 in
 above frame.Question? How long do I turn
 on light bulb for first experiment in developeing
 board.If it fails to develope properly
 how much time do I add for next
 experiment?What is correct procedure for
 this experiment to learn this aspect properly?
 
     
      
 
     
     
 
 
 
 #yiv9227428166 #yiv9227428166 --

RE: [Homebrew_PCBs] First Negative developement Brd

2016-08-19 by keith printy

When I used to expose the photo resist on the boards I used a sunlamp. I forget what the timing was though ,haven’t done this in many years.

Show quoted textHide quoted text

From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] 
Sent: Friday, August 19, 2016 10:44 AM
To: Homebrew_PCBs@yahoogroups.com
Subject: Re: [Homebrew_PCBs] First Negative developement Brd

Forgot to add, cover glass can absorbe the UV required by the film, so you may need to experiment with that also..

Malcolm

I don't suffer from insanity I enjoy it! 
Mene, mene, tekel, upharsin 
The writing is on the wall. 
Ha-ktovet al ha-kir

--------------------------------------------
On Fri, 8/19/16, kbyrne10@... [Homebrew_PCBs] <Homebrew_PCBs@yahoogroups.com> wrote:

Subject: [Homebrew_PCBs] First Negative developement Brd
To: Homebrew_PCBs@yahoogroups.com
Date: Friday, August 19, 2016, 1:36 PM

I finally have all the supplies that I
need and need a question
answered.SuppliesScotch
LaminatorOffice depot Black and white
copier transparencies. Two copies of each experiment
circuit.Dry film bought in
ChinaPH up bought on
E-BayEagle to Gimp
negativeDakta light bulb approx 12 in
above frame.Question? How long do I turn
on light bulb for first experiment in developeing
board.If it fails to develope properly
how much time do I add for next
experiment?What is correct procedure for
this experiment to learn this aspect properly?

#yiv9227428166 #yiv9227428166 --

Re: First Negative developement Brd

2016-08-20 by alan00463@...

I haven't done UV photolithography myself, but recently watched
Mr Scully's youtube video demo. of it, where he goes over all its
steps in great detail. if you get bored, skip to 11:40 for the UV exposure,
https://www.youtube.com/watch?v=zoiIkwaBv6o

Re: [Homebrew_PCBs] Re: First Negative developement Brd

2016-08-21 by Donald H Locker

He does so many things that I wouldn't recommend, though he does at least use gloves -

NEVER handle the board like a sheet of paper (touching the surfaces) - only handle by the edges (he says something about this at the very end of the video, but by then all the damage has been done - he's got prints all over already. In this case, they didn't damage the work, but it's a bad habit and hard to lose. If you always only touch the edges you'll never find fingerprints on your copper.)
NEVER put your fingers into the developer or etchant - always use plastic tongs. (Gloves leak or one day you'll forget about it and just reach in without a glove, coming out with a very nasty burn - develop the habit of using tongs early.)
ALWAYS rock the tray holding the board to assist development rather than rub the developer across the board. Again, a matter of personal safety and keeping the board clean.
Always tape the board to the patterned transparency - taping the transparency to the light table doesn't keep the board aligned with the pattern, which is what matters.
ALWAYS locate the transparency/board combination in the place where the UV is most uniform - middle of the lamps (not at the ends, as he does.)

I'll be quiet now.
Grumpy Donald.


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

Show quoted textHide quoted text

> From: "alan00463@... [Homebrew_PCBs]" <Homebrew_PCBs@yahoogroups.com>
> To: "Homebrew PCBs" <Homebrew_PCBs@yahoogroups.com>
> Sent: Friday, August 19, 2016 9:52:31 PM
> Subject: [Homebrew_PCBs] Re: First Negative developement Brd
> 
> I haven't done UV photolithography myself, but recently watched
> Mr Scully's youtube video demo. of it, where he goes over all its
> steps in great detail.      if you get bored, skip to 11:40 for the UV
> exposure,
> https://www.youtube.com/watch?v=zoiIkwaBv6o
> https://www.youtube.com/watch?v=zoiIkwaBv6o

Re: [Homebrew_PCBs] Re: First Negative developement Brd

2016-08-21 by Kevin Byrne

Thank you to all that replied to my questions. There seem to be a lot of differences in the amount of time board is under light. From  one minute up to eight or more minutes.A test to the light system to determine how much time is in the works today. I have foambrushes to eliminate the rocking I was never happy with with etchant.

RE: [Homebrew_PCBs] Re: First Negative developement Brd

2016-08-21 by keith printy

I think I used to expose the photoresist for about 5 minutes under the sunlamp. I used glass to hold down my negative on the board. Has been a while since I have done that though.

Show quoted textHide quoted text

From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] 
Sent: Sunday, August 21, 2016 7:25 AM
To: Homebrew_PCBs@yahoogroups.com
Subject: Re: [Homebrew_PCBs] Re: First Negative developement Brd

Thank you to all that replied to my questions. There seem to be a lot of differences in the amount of time board is under light. From  one minute up to eight or more minutes.

A test to the light system to determine how much time is in the works today. I have foam

brushes to eliminate the rocking I was never happy with with etchant.

RE: [Homebrew_PCBs] Re: First Negative developement Brd

2016-08-21 by Kevin Byrne

Datak states with their 300  watt ER-2000 bulb placed 12" above board 3 1/2 to 4 minutes for a small board, larger board sizes 5" X 5" and 9" X 9" raise light up to 15"then turn on light for 15". Does anyone know this supplier as to quality? http://www.philmore-datak.com./ Best Kevin

RE: [Homebrew_PCBs] Re: First Negative developement Brd

2016-08-21 by keith printy

We used the Kodak resist when I did it at work and I used the gc electronics spray at home. Used a sunlamp for about 5 minutes . I believe this included the warm up time.

Show quoted textHide quoted text

From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] 
Sent: Sunday, August 21, 2016 11:01 AM
To: Homebrew_PCBs@yahoogroups.com
Subject: RE: [Homebrew_PCBs] Re: First Negative developement Brd

 

  

Datak states with their 300  watt ER-2000 bulb placed 12" above board 3 1/2 to 4 minutes for a small board, larger board sizes 5" X 5" and 9" X 9" raise light up to 15"

then turn on light for 15". Does anyone know this supplier as to quality? http://www.philmore-datak.com./ Best Kevin

RE: [Homebrew_PCBs] Re: First Negative developement Brd

2016-08-21 by Kevin Byrne

Light bulb was a flop till I raised the length of time to 11 min in wood box under bulb approx. 12 in. I got two good to go tone control boards done today except etchant.Problem is also quality of dry resist film bought in china cheep. From 40 sec up to 9 min was included in all my research. What is all the hype of over exposure and what do I look for? All traces are under the size of a header pad by quite a lot, smaller than a .046 transistor pad I beleive the measurement was.