Homebrew PCBs

You can use a 21 step stouffer gauge ($12) to check where you are in
relation to the optimal exposure time.  2.5" sounds close.  The closer the
bulb, the more the light hits the board at and angle where ideally
perpendicular is wanted.  Maybe you are not doing any fine artwork?  What
resist and UV lamp are you using?

 

Jeff

 

  _____  

From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
On Behalf Of Rick Sparber
Sent: Friday, November 23, 2012 3:15 PM
To: Homebrew_PCBs@yahoogroups.com
Subject: [Homebrew_PCBs] success!

 

  

A friend looked at my pictures of my failed etchings and suggested I lower
my UV light and greatly extend the exposure time. I went from 7" down to
2.5" and from 1 minute to 8 minutes. HUGE improvement. My first test piece
was done etching in 9 minutes with the ferric chloride at about 75F. The
second test piece used the same set up and chemicals but the acid sat out in
the Arizona sun for about 15 minutes so must have warmed up. It etched in
5.5 minutes.

My next test cycle will be with all the same except I will try using
convection etching.

Rick

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





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