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Subject: SMD headers (was Re: PCB Driller - aligning holes)

From: "Dave Mucha" <dave_mucha@...>
Date: 2004-11-22

--- In Homebrew_PCBs@yahoogroups.com, "Phil" <phil1960us@y...> wrote:
>
> --- In Homebrew_PCBs@yahoogroups.com, "Dave Mucha" <dave_mucha@y...>
> wrote:
> ....
> > When I got my T-TEch machine, it came with a couple sheets of 1oz
dbl
> > sided with a very white substrate. the copper pealed off very
> > easily. So easy that it was easier to peal than to use the
cutter
> > to clear large sections of unused area.
> >
> > The FR-4 I used next was next to impossible to peal and the CM-1
I
> > now use is very easy compared to FR4 but not quite as easy as the
> > other stuff.
>
>
> Maybe this is a stupid question but why whould you want copper that
> peels off that easily? I have enough trouble trying to AVOID
lifting
> pads and traces that any gain from clearing large areas would be
lost
> to damaged boards. I want my copper to adhere very tightly.
(there's
> a bad joke in there but I shall desist). Wouldn't the large areas
be
> better left as ground planes?
>
> Phil


Check out the photos section, Daves Drill. the third picture.

Imagine if you wanted to remove all the copper with a mechanical
etcher. It would take hours and probably destroy the cutter in short
order.

I get boards by mechanically etching the outlines and then pealing
the excess copper.

The board in the foreground is partially pealed.

Imagine trying to only solder the pads around the excess copper.

This is the largest drawback with using mechanical etchers.

Dave