Found this excellent guide:
http://pminmo.com/pcbmaking.pdf
The key is that toner ink will protect the copper from etch fluid?
Yes. And if you take the time to absorb and understand the
information in the link that Decatur posted, it is even better
than the good one you posted.
Let me emphasise some key points in the process:
1) You want the copper on the PC board you will use
to be *clean*. I mean *CLEAN*
2) Do *not* rush the ironing. Use the 4 or 5 minutes
recommended and keep steady firm pressure while moving
the iron to prevent scorching.
3) Soak the bejusus out of the paper and board after
ironing - dunk it in a container of hot water and let
the thing soak until the paper comes away from the copper
without pulling the toner with it. In other words:
"DON'T PULL ON THE DAMN PAPER TOO SOON". Ask me how I know.
4) Gently rub the board to get most of the residue paper
off. Residue that seems to be embedded in the toner won't
hurt as long as the toner paths have crisp edges.
5) This is not so key - but bears mentioning. Etching
takes time. It can be sped up by keeping the etching
solution warm and by agitating it. But don't look to set
speed records. I use a container that I can tilt to
expose the board to see how much copper has been removed
so that I don't have to stick anything in to the solution
to grab the board to inspect it. That keeps the etching
solution in the container, rather than getting on a glove
or a tool. Once it is out of the container and onto a tool
or a glove, it is one short step from staining something.
And it *will* stain.
When etching is done, wash the board well with water to remove
any etching material. Then remove the toner, drill the holes,
and build away.
Ed
