Homebrew PCBs

In a message dated 06-Dec-01 10:10:12 Central Standard Time, 
thor918@... writes:


> Does anybody know how to print on top of the pcb.
> 

Thor:  This is done by "silk-screening".  A photographically-made "screen" 
(once made only of silk, but I think, nowadays, some tougher polyester is 
used?) is used as a stencil, and PAINT is "squeegied" onto the board.  The 
screen is liquid-tight in areas where you do NOT want the paint, and only the 
"screen" (open weave of the "silk" cloth) is clear, allowing paint to squeeze 
through.  This is an "art" which is used in more than just PCB work!  All 
kinds of posters, signs, labels, etc., are made by the familiar "silk-screen" 
method.

HOWEVER!  If you just MUST have some labelling on the "top" of a PCB, but 
wanna make only ONE, and NOT spend all that for the frame, silk-screen stock, 
developer, squeegie-tool, paint, etc., you can use IMPRESSION lettering 
and/or patterns.  Good art-supply stores will have more than just letters in 
that stuff!  You want white or maybe yellow, but NOT black, etc., as those 
colors hardly show on a FR-4 board.  Once you have "rubbed off" your entire 
pattern, words, labels, etc., then SPRAY the top with clear enamel or 
lacquer. AFTER you have etched!  And be careful not to get any of that on the 
"copper side"!  It will look as nice as your steady hand can do that!  I have 
done this countless times!  Also, for making "professional looking" panels!  
Dial-numbers, ON/OFF, etc.  Just SPRAY it after all the rubbing-off/on is 
done!

Jan Rowland