In article ,
Bruce W.1 wrote:

I've been told there is a way to make a circuit board with a computer
printer, i.e. make the traces on the back side. Can anyone tell me
about this?

There are several.

One way is to laser-print the resist pattern onto a transparency (or
laser-print into paper and photocopy onto a transparency) and then use
the resulting transparency as a photographic mask, exposing a piece of
photosensitized PCB material to UV light through the mask. The
exposed photo-resist is then developed (chemically in many cases) and
the unexposed portion is washed away (or vice versa - depends on the
type of resist) and the board is etched.

Another way is to laser-print the resist pattern (mirrored
left-for-right) on a specialized sort of coated paper. The PC board
material is cleaned thoroughly, the printed paper is placed on the
board toner-side-down and carefully ironed onto the board - the resist
melts and sticks to the clean copper. The board is soaked in water,
and the coating on the paper releases the toner/resist and the paper
washes off of the board. The board is then etched. There are
commercial papers made for this purpose, I've heard of people using
some glossy-surfaced inkjet papers, and some folks even make their own
by brushing a liquid gelatin solution onto smooth paper.

It's also possible to use a flatbed plotter, with a special pen, to
draw resist patterns directly on PC board material.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
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