From: sleeper75se (sleeper75se_at_yahoo.se)
Date: 2002-01-09 17:45:58
--- In buildcheapeeg_at_yahoogroups.com, "Jim Meissner" <jpmeissner_at_mindspring.com> wrote:
> Dear Andreas:
>
> I am also very interested in learning your double sided PC board
technique.
>
> I make my own single sided boards using a Kepro UV light box. I
etch with ferric chloride with an air bubble stirrer in a heated
bath. I use the positive resist pre-sensitized boards. Much of my
artwork was done with tape and donut negatives, some with rub on
transfers. I have experimented with a simple PC program and printed
to transparencies with my 300 DPI Laser printer. I have to tape two
of the transparencies together to make it dark enough. I also have
an Epson color 660 printer. That is what I have.
Hi Jim,
300dpi is 3mils, so perhaps it works with 15 mil details, but keep on
experimenting.
> I think what I need is a program to do the artwork. What are you
> using and how can I get that.
> Also how do you do the schematics, and how can I get that program.
It is the same program for both tasks, Protel 99. However, I access
it through work so it is not really for home use, unless you have a
lot of money to lying around. However, they have a 30-day trial
version with all the features enabled available for download:
Another, more moderately priced system is ultiboard, but they don't
have a usable demo (saving is disabled):
> What brand, part number transparencies are you using?
I print on plain, thin, paper for office use, and it works fine. Some
people even claim it works better than film, because paper is thinner
than transparencies. The lower contrast doesn't seem to affect the
result, so try using just a single paper instead of double
transparencies. You will need longer exposure though, about 15
minutes or perhaps a bit more. Depends on the UV-light, and paper so
on.
> Laser or Ink jet? Which do you recommend?
Whichever gives the darkest, sharpest image. Probably laser, with
newly replaced toner. For boards with ground planes you may need a
professional printer (or negative photo resist), because home laser
printers don't handle large black surfaces well. Fortunately, all
print shops use those, so there's no need spend $10000 on a printer.
> Please tell me about the etching solution also.
I haven't had a chance to check out the details yet, but if I
remember correctly you will need
1 part 40% HCl in 4 parts water
and
1 part 40% H2O2 (More H2O2 means a faster process)
(I'm not sure about the 40% figure though...will check.)
mixed together in a plastic vessel big enough for the board. You
don't need a lot of liquid. Just enough to cover.
You get some chlorine gas in the process and you *don't* want to
smell the undiluted HCl, :-), so good ventilation is necessary.
After developing (I use NaOH solution), just put the board in the
etching tank and stir by tilting the tank. You will need a set of
pliers made of plastic, the same kind that's used when developing
photographs.
Ok, after etching: Don't pour the liquid down the drain... it will
corrode the pipes. Store it in a container with a small "breathing"-
hole in the cap and give the container to a company that handles
hazardous waste when it is full.
Oh, by the way, you don't get any sludge (or whatever it is called)
when you etch this way. Just a nice clear blue/green solution that
looks like soda pop (DONT drink it. ;-)
I hope I've covered most parts here... let me know if you have any
more questions.
/Andreas
This archive was generated by hypermail 2.1.4 : 2002-07-27 12:28:36 BST