ODP: Newbie PCB ques..

[Roman Sowa]

Since it gets so wide response, so maybe I could give my PLN 0.03

I don't know what is a "kook" mentioned by Harry Bissell (probably something
bad), but it must be me - I placed tracks between DIP leads many times
with good result. I don't know how would I do my CPU boards other way.

anyway here's my story of making homebrew pcbs:
1. Design PCB layout with some CAD software, or on paper
2. Print "drill guide" or "pad master" in 1:1, where only small dots are
printed
(on paper) and, of course, both layers in appropriate scale.
3. Stick the paper to PCB with transparent adhesive tape
4. Drill through the paper - the drill comes in more steady than without
paper
(doesn't slip) 0.6mm for vias, 0.8-1mm for components
5. Cut sharpy hole edges with a knife
6. Use carbid (?) paper to make the copper shine
7. Wash it depending on your choice (I use soap + water)
8. Put the board on clean styrofoam, so you can rotate the foam, not board.
(bottom side doesn't get scratched)
9. Paint the artwork. I use old automobile anti-rust tar paint desolved in a
solvent
(the one that does not react with polystyrene). As painting tool I use this
device
used by draftsmen (?). It is small pipe (0.5mm inner diameter) with wire
inside.
For thinner tracks I use smaller bit - 0.3mm. Works perfectly for SSOP
packages
(0.65mm lead pitch). With this you can freely use all kinds of rulers, so
tracks
are straight and look pro-like.
8. Turn the board upside down, and paint the artwork on the other side
(holes
are your guides). Don't forget to print bottom layer in mirror version.
This tar-paint dries fast, so no need to extra drying, unless you put thick
layer
of it.
9. Etch it in ferrum chloride, or nitro acid. Not too strong, but decent
amount of
bubbles coming out during etching process doesn't hurt painted traces.
10. Wash off the paint with nitro solvent
11a. Make vias. Put 0.6mm copper wire in via hole, and cut it, so it sticks
out of
each side for about 0.5-1mm. Take a hammer and smash it! this way you get
almost invisible vias. After that you must solder all vias from both sides
for
protection.
11b. Make vias - another way. Put small pieces of thin wire into via holes,
bend it
from both sides, and siply solder.
12. Fluxing (optional). Disolve rosin in alcohol, and paint the board with
it.
I pour some of alcohol in rosin can, and stir till it leaves visible marks
on paper.
12a. Dry the flux in an oven 100-150 deg C for 20 minutes
13. Voila!

Final remarks:
I had never problem with side-etching phenomenon, so I don't paint tracks
wider
and dont drill the board after etching
For large areas I use bits of adhesive tape and paint it around.Less work,
good results.
This tar-paint is the best stuff I've ever seen. No permanent markers or
anything
works better. Even layers so thin that copper shines through are safe.

But now, I use this method only when I want PCB quick. Usually I send
design file to PCB shop, and get boards 2 weeks later.

hope this is at least a little help to anyone

Roman