Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

Hi folks!

I am new to the group. I very much want to use a milling machine
approach to mechanically mill my circuits. I like the idea of being
able to (perhaps) build part of a circuit...and then be able to add
to it later. Something completely impossible with any technique
that relies upon chemical milling. So, I find myself trying to build
a little cnc mill. (I mean little. 3"x4"x3" of travel - the size of
my linear slides...taken from a Reticon camera scan platform. I have
some beautiful 12" ballscrews which will be sadly under-utilized
driving it...:-)

Anyway, as you can imagine...I find I need to produce three
identical PCBs for the three servo motor controllers. So, I have a
circuit laid out...but I find I cannot seem to get the Toner
Transfer process to work. I have tried all the recommended papers
(i.e. Magazine paper, Staples "Picture Paper", etc...to no avail.)

Finally, thinking I would try a photographic method, I got my hands
on some viewgraph transparencies. I intended to make a "positive"
for a contact photographic process.

But then I thought. What the heck. I will try a Toner Transfer with
the plastic viewgraph transparencies. Lo and Behold! It actually
worked.

In fact, I transferred so much toner...it was even smearing. It
seems to want LESS heat and pressure.

I think I like this method (it isn't perfect, yet...but it's the
most ink-on-copper that I have seen!)

A few things to note:

1. I printed on the "smooth" side of the transparencies...figuring I
didn't WANT the toner to stick too well.
2. I used an iron on high heat. This seemed to be too high. The
toner was melted onto the copper in seconds. In fact, in areas it
started to smear...probably from the combination of too much heat
and my pressing down on it too hard. I will try a lower setting on
the iron...and less pressure.
3. Clean-up is easy. You peel it off like a giant piece of scotch
tape. Hey, is this like dry Press-n-Peel? :-)

Anyone else have any good experiences with this method? Any hints?
I didn't see this mentioned in the group...

Excuse the long post. It's my first.

Jim