gEDA-user: PCM making methods - was - Re: alarm clock update

[andrewm <andrewm@xxxxxxxxxxxxxxx>]

 >> JohnG wrote:
 >> What do you all think about inkjetting of resists?

The second biggest problem apparent with direct
inkjet is pooling.  The big problem is surely the ink
not actually resisting.  But pooling caused by too
much ink in one spot while wet is causing uneven
coverage and the thin areas wash away or crack.

Filling all the carts with one colour and printing
composite black will prob make that worse.

Maybe one solution is to hack the printer or rewrite
the driver to do single pixel bands with a few seconds
between each pass to allow ink to dry.

I never looked into it too much as I didnt find the
other methods of making a PCB too painful.

 > DJ Delorie wrote:
 > In my case, since I was etching brass, I probably
 > could have just run the brass through an unmodified
 > printer. But getting the right inks and keeping the
 > nozzles clean seems to be a tricky bit for them.
 > Heck, I have a hard time keeping the nozzles clean
 > with the original inks.

DJ - When you are etching your brass stencils they
are almost all resist and only tiny apatures.  If you
work out the cost of inkjet ink and the amount of
coverage you need - it may make a $200K laser
cutter seem like a prudent investment :D

 > What I'm contemplating is switching to photoresist.
 > You print the pattern on transparencies, photoexpose,
 > develop, and etch. No laminating, soaking, etc. The
 > advantage is that it's easy to line up transparencies
 > because you can see through them, so doing double
 > sided PCBs (or in this case, etch brass from both
 > sides) is easier.

YAY - another convert to photo :D.

To be honest I have just bought some inkjet paper to
re-try the toner transfer option.  I was doing it 10-15
years ago using OHTs.  The trannys gave beautiful
results but where temperamental.  The photo paper is
quite reasonable in terms of quality and I may use it
from time to time on single sided baords with 16/16
rules.  I am going to stick to photo for the DS 6/6
stuff though.

 > I might switch etchants to something see-through too,
 > like the HCl/H2O2 mix.


HCl/H2H2 (and the CuCl I use) do not give as sharp
an edge as FeCl3. Also I think for your brass masks
that HCl may not be the best solution.  Check with
someone smarter than me, but I think it is bad with
brass.




_______________________________________________
geda-user mailing list
geda-user@xxxxxxxxxxxxxx
http://www.seul.org/cgi-bin/mailman/listinfo/geda-user