Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

Well I never saw where he said he was using M.G. Chemicals boards, I
have used 100's of their 600 series boards over the years noramlly
8x10 or 8x12 boards, that I cut up into smaller boards after etching.
I see one of my board pictures has made it on the Home Page. Never
had any kind of problem with resist being missing like that. Might
have a few small bad places along a edge where they cut it, but
normally not a problem, and maybe had a couple that had a small
scratch on them, there again not normally a big problem. M G
Chemicals boards seem to me to be some of the best available, I don't
buy anything else anymore. No they are not the cheapest in price
either.

First off, you must have your artwork in direct contact with your
board, ink side towards the board. The glass to do any good must be
flat against the Artwork. Transparencies is what I find to work best,
they must be for inkjet printer for best results. I use a HP and use
HP transparency only, other brands may not work as good even those
that say they are for your machine. I have tried the tracing paper or
veluem paper, really does not work as good, Black ink seems to work
best on the veluem paper if you want to try. What I have found to
work best is printing to Transparency using yellow ink. I am told
that using photo cyan (green & yellow together) if you have a photo
printer works even better. Also find it is good to run your printer
thru it cleaning process, seems to help keep it from streaking some.

Yes UV is correct, I use the Black Light tubes, I use 4 of the
F15T8/BLB lamps, I think that is the right #. Having the light source
back a little ways seems to help stop undercutting. Have not tried
yet but some have talked about using the egg crate you put in lights
to only get direct light downward.

Developer I use the M G Chemicals which is Sodium Hydroxide also
believe called Lye. Find it works best if you mix it with warm water
just before you are to use it.

I use Ferric Chloride, yes it can be messy if your not careful with it
but you need to be careful with any of the etchants or other chemicals
one might use in making PCB's. Works best Heated, and needs some way
to keep the etchant moving. I have a 5 Gal. tank with air bubbles to
move the etchant.

My exposure time is using the yellow ink on transparency is about 5
min, Black ink ran about the same but did not work as well, got more
pitting and small breaks in traces but where still good.
My Etch Time is about 6 to 12 Min if the etchant was Heated well and
depends on how fresh the etchant is also.

If you are planning on making board on a regular basis then I would
recommend that you have you a place you can leave setup and have
access to running water.

Myself I leave the resist on the board, load it and solder it then
spray with a clear lacquer.

Cutting methods I have found that work best are Table Saw, but need
good dust colection system in place and filter protect you motor from
sucking in the dust. I use a wet/dry diamond blade, use it dry. You
do have to account for the blade kerf in spacing your boards on the
larger board.

Other method is a bench shear, I use one by Kepro, not cheap but I
found mine used on ebay. They are still available from a company that
took over Kepro, link to them should be in the Links section.


Hope that helps.

Ben