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

""I think that the really fine-line stuff is made by copper
deposition, not etching. Leon ""


yes, it's called the "additive process". (as opposed to
'subtractive').

However, plenty of fine-line work is done subtractively as well.

In chem-milling metal parts, you don't have the option of
additive-processing....you're starting with an existing part
(usually stainless steel or possibly brass), and have to work
from there.

Stefan: I can only assume you did not read my post; as nowhere
in
it did I claim to have etched 1-mil traces on 2oz copper. To
you,
perhaps 35um is 'normal'; but most work of this nature is done on

.5oz laminate. That's 'normal' for fine-line work...and even
.25oz
material is used.

Howver, one can do pretty fine work on 1oz material as well;
which is generally much easier to find.

For anyone here trying to do 8-mil traces for SMT work, and
still using 'typical' 2oz copper base stock; I highly recommend
switching to 1oz stock!

Unless you're running 10-20 amps through tiny traces, you just
don't need 2oz; and it makes your etching job SO much harder.

Actually, I use 1oz for virtually everything....even if the
features
are 10-mils and up. It's just so much easier to work with; i.e.
to
get a clean etch, every time.

ps; regarding the microetch Leon, I do it because it's the
-easiest-
way to guarantee a clean surface....and I'm 'lazy' ! <grin>

A little scrub with the soap....rinse....drop it in the
microetch...swish
swish....Done. Perfect brand-new clean copper surface, in
seconds.

And it's dirt-cheap, since I already have gallons of it for
etch-bath;
and I never have to worry about contaminants from commercial
'cleaners' with unknown composition.

To me, microetch IS the easiest, fastest, and cheapest way to
clean.

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