OT: how big would it be? - PCBs at home

From: Marvin <marvin_at_rain.org>
Date: Fri Oct 22 15:36:33 1999

daniel wrote:
>
> Making PCBs at home is a rediculous waste of time. I have a vacuum lightbox

That really depends on what you want to do. Before I started a printed
circuit mfg company, I did make them at home for considerably less money
that it cost to have them made.

> here as well as a commercial processing system, a silkscreening set up, even
> a wave solder machine in my home and nothing compares to what the big guys
> can do and charge for the same thing. My last *production* company use to

Again, what are you trying to do? Silkscreening circuits require a fine
stainless mesh and a good chase unless you are only after a crude, make it
work, type of pcb.

> make its own prototype doublesided PCBs in house and it wasn't worth it. I
> have a company I use now that will make me a double sided PCB, GOLD PLATED
> contacts, solder mask both sides (pre-drilled of course), and silk screened,
> and cut for less than a $1 a board in quantities of 500.

Need to mention the board size, number of holes, and setup charges for that
$1 a board to mean anything :).


> Pre-sensitised boards are useless as they usually come flawed and the
> coating thickness is not consitant. The company I use now for PCBs used a
> "roll" of sentised film that was "ironed" onto a 3' X 3' board. Far better
> process.

Using dry film is an excellent approach used by most professional pc board
houses, and the equipment isn't all that expensive (depending on your frame
of reference.) Older dry film laminators can probably still be had in the
$1k area. Of course, at a $100+ per roll of dry film, and the fact it has a
limited shelf life make the process impractical unless a number of boards
are being made on a regular basis.

> Don't forget a good GERBER and NC drill file is needed and most PCB
> manufacturers find little problems with the files that you may not uncover

Actually there are a number of ways to make artwork; gerber files and NC
files are not required. An NC drill file can be created from artwork. I have
seen camera ready artwork produced by electrical tape on a piece of mylar
(funny but true), produced by linotronic printers, printed by dot matrix
printers, and a number of other ways.

FWIW, a local shop will also produce undrilled pc boards just printed and
etched for about $0.30/sq in total cost. This is a wonderful service for
fast, inexpensive prototype SS or DS circuit boards.
Received on Fri Oct 22 1999 - 15:36:33 BST