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Subject: Re: [Homebrew_PCBs] Re: Circuit Cellar article

From: "Stefan Trethan" <stefan_trethan@...>
Date: 2007-04-28

On Fri, 27 Apr 2007 10:30:28 +0200, martin_schoenegg
<Martin.Schoenegg@...> wrote:

>
> Oh guys. I did this 15 years before :-)
> But the process isn't stable. Very often the tip smears as it reaches
> earlier drawn traces or pads (T-connections) or thicker traces that
> needs to be drawn with parallel lines. After tryinig a lot different
> pens (Staedler I used too) and several costy steel-tips with lots of
> different inks I switched back to photoprocess. May be my plotter is
> too fast.

Tried the same, same results, same box of useless but expensive steel and
carbide tipped pens.

> By the way: The best "ink" I used was colophonium in isopropyl
> alcohol. It is a good and cheal resist and you don't have to remove
> it, just solder. And if you draw the lines with a tinned solder iron
> the board is quickly tinned and stable for years. there is only one
> small disadvantage with colophonium alcohol ink: it is very
> transparent. Therefor i mix one or two drops of staedler refill ink.
> You may try this... Nowadays I prefer toner transfer.

Now you are starting to scare me. I also tried colophony resin, also with
some staedtler refill ink.
You could've told me, you know, saved me the trouble and all... ;-)

The laser will most likely not work because only about 50% of toner is
transferred without the static pickup, i doubt the R produces enough toner
so that 50% still resists.
One thing that could work is a silicone roller below the drum as a
transfer roller, which picks up the toner (with static charge) and
transfers it to a board running by below (which can be heated and fuse the
toner in the same step because the roller can be heat-proof silicone. Not
my idea either that one.

ST