[chbot] Anyone making PCBs?

[Robin Gilks]

> On Sat, 04 Jun 2011 13:32:18 Volker Kuhlmann wrote:
>> Yes, that makes sense. Is it really necessary to remove all the last bit
>> of copper oxide, and to use acetone? Fingerprints will be a k.o., but
>> they come off with meths. Did you by chance try it with meths insted of
>> acetone?
>
> Ok, I don't have meths (Ethanol with a small percentage of Methanol), but
> I do
> have 99% pure Methanol.  I tried cleaning the toner from a board that
> didn't
> transfer well (so I can re-use the board material).  Methanol does not
> dissolve the toner.  It does seem to clean the exposed copper well, but
> has
> no effect on the toner.  I might use Methanol instead of Acetone to clean
> the
> board before etching, and then use Acetone to remove the toner after
> etching.

I've found that Hammerite thinners, which is xylene based, works a treat
at shifting the toner from the copper. There may be other paint thinners
with the same ingredients.

I've used Press n' Peel in the past but found that matt inkjet paper to be
much better. The toner bonds to the kaolin (chalky) layer of the paper so
when you put it into water to remove the paper you don't get lots of hairy
wood fibers sticking out!! I found the Press n' Peel to flake off the
sheet and ended up with quite jaggy edges to the traces.

The main thing to master with toner transfer is getting the iron to the
correct heat (it should be sszzzzzzzzt when you spit on it not
SSSZZZZZZZT!) - something about 150C - and to not press too hard as that
squeezes the toner out and blurs the traces.


-- 
Robin Gilks