Hello Mark,
An afterthought or two.
I find that when I have to visually examine something in fine detail, it is
easier to scan it on my scanner at maximum resolution and then scroll
through the image on the PC screen. Perhaps you can do this with the fuser
PCB to look for clues.
If the problem is air pockets then it may pay to go over the PCB with very
fine sand/emery paper (1200) before printing.
Robert.
----- Original Message -----
From: "Mark Lerman" <mlerman@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Thursday, April 03, 2008 7:16 AM
Subject: [Homebrew_PCBs] Direct Toner - First Try Results
I just made my first (single sided) board using my modified laser
printer that deposits toner directly on the board. A few observations
and questions:
1- I used the Eagle Demo2 board, but inserted four 2 mil traces
between 2 of the dip pads, each connecting to one of 4 adjacent pads.
These are 2 mil traces on 10 mil centers, with the traces on the
sides being 7.5 mils from the pads.
2 - I used some of Dave's gel on the 1/32 inch thick board - will try
without it later.
3 - I then ran the board through a laminator once - no carrier.
4- I etched using muriatic acid / peroxide, room temperature, a
little agitation by hand rocking the board.
The board came out okay, but there is some pitting that I am not
happy with. All four 2 mil traces are intact, none of them are
shorted. Questions:
1 - Should I have run the board through the laminator more than
once? I bought the laminator at Staples, no model number on the box,
but I believe it is one of those recommended on the laminator link.
I'll have to measure the temperature sometime. Any other thoughts re
the laminator?
2 - Would I be better off using an oven or hotplate to fuse the
toner? I can control the temperature quite well, but will the toner
fuse well without the pressure?
3 - What causes the pitting? Too long in the etchant? Toner not
completely fused? All the traces and pads seem equally pitted, so I
don't think it's the trace width.
Lots of questions, but I realize that I am on somewhat uncharted
territory here. It's going to take time and experimentation to work
it all out, but I'm excited by the possibilities of this technique.
Mark
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