HP calculator thermal printheads (HP82143, etc) - test-drb@ccmp.vtda.org

6 May 2000

On May 6, 11:54, technoid(a)cheta.net wrote:
...
  In order to make fine traces with Nickel Print
conductive paint I used
 paper matches.  Yeah, the kind you light your Camels with.

 Cut the base of the match off at a 45' angle.  This gives you a nice point
...
  and the paper holds enough paint to make a halfway
decent brush.  They are
...
  only good for a trace or two so have a full pack
handy. 
I find a  good-quality No.2 artist's brush (not smaller) will have a very
fine point and do an excellent job.

...
  I've used tape to cover the traces but when you
peel the tape up you peel
 the traces with it.  The scalpel approach works pretty well but leaves
 ugly traces and is hard to do once the paint is dry.  I use the matches
 and the scalpel together in real-time so I'm scraping at wet paint. 
I perhaps have an advantage in that I learnt to retouch photographic
negatives (and prints) with a scalpel and retouching brush.  PCB traces are
easy by comparision.  You don't try to scratch through in one go; rather
try to gradually pare down to the substrate.

...
  >Ugh,  that is exact same thing what I did many
times in my retired
 >compaq LTE 386s/20 on one of two keyboard cable.  Is there a better
 >quality kind than this conductive paint I got?  Then name one! 
I don't know what kind you've got :-)  The kind I use is silver-loaded, and
seems to stick well, and work well.  It's made in the U.K.

-- 

Pete						Peter Turnbull
						Dept. of Computer Science
						University of York