[chbot] Anyone making PCBs?

[Andrew Errington]

On Mon, 06 Jun 2011 19:46:38 Robin Gilks wrote:
> 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.

Noted!

I tried four transfers tonight.  I have three pieces of board and four artwork 
prints.  I tried one with just acetone as I said I would, but it didn't work.  
I think it could work as some small parts of the toner did stick.  It might 
be worth trying again, but I am not sure that my acetone doesn't have other 
ingredients (it is Nail Varnish Remover).  It might have water or some 
moisturisers or something (the label is in Korean).  It certainly dissolves 
the toner when I need to clean up the mistakes...

Board 2 was done in the 'conventional' way.  I got excellent adhesion, but the 
traces were smudged.  Probably too hot as you say, or maybe too much 
pressure.  It is a clothes iron set to Max, so I might need to dial it down a 
little.

Board 3 and 4 were good.  Good adhesion and only a little smudging.  I 
basically used the weight of the iron to press the board.  Each board is 
about 20mm x 20mm so they are much smaller than the iron.  I also have to 
keep removing the iron as it is cordless, so it needs to be placed on its 
cradle to re-heat.  Afterwards I used a Sharpie to touch up some holes in the 
toner, and a craft knife to remove some smudges.

Etching was a little slow.  I don't know how much copper the etchant can 
remove, but it was the same etchant as last time.  I added more peroxide (as 
I have read) and eventually the two boards were etched.  There are some voids 
where I missed holes in the toner.

So, I still have one piece of board needing etching.  I will print more 
artwork tomorrow.  Then I have to drill some holes for the through-hole 
connector and flying leads.

The Press N Peel at Jaycar is rather expensive IMHO, but maybe it gives more 
consistent results.

A