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Subject: Re: EDM of PCB

From: "Andrew" <andrewm1973@...>
Date: 2006-05-10

> Mark wrote:
> I'm new at this. Would you mind giving
> a newbie some idea into the how's and
> why's of using rivets of some sort to
> produce via's for two sided boards?

Until I get home I am on a 10k baud (yes
thats kilo baud not megabaud) or so speed
connection. I have done a quick google
to find the cooper tools set I use.
(the weller soldering iron and multicore
solder people)

I could not use the cooper tools web site
at all 'cause it is a java-flash-graphic
nightmare. However there is this page

http://www.electricstuff.co.uk/pcbs.html

that I beleive shows pictures of it.
That is from memory that they have piccies
though as I have about 10 thousand reasons
to not have images on unless I realy need
too.

I have been using the cooper tools rivet
system for many years now. Although it
looks like it might be a nightmare, once
you get proficient at it - it only takes
a few seconds per via.

For a couple of hundred dollars the set
is well worth it for the easy of use.
However you could get by much cheaper
by just buying the bails of rivets and
buying your own automatic punch from
a local hardware store.

If you use carbide drills in a good high
speed drill press - you dont need to go
through the "reaming" step shown in the
cooperset instructions.

I have not used the snap off pin things
shown in the above website. But I do
suspect they would be even easier than
the copperset ones. That is as long as
the hole is a via not a pad.

There is another "rivit" system that
the bungard website shows as well. I
have never used that system - but it
looks like it may be more robust, though
not as able to make small vias.

Maybe someone else on the group has
experience with the bungard rivets.

> I think I've got the alignment problems
> licked for producing a two-sided board,
> but the idea of soldering little wires
> in place for each via seemed pretty
> laborious. I've been trying to find an
> easier, better way to do it and this
> sounds like it might be it. If you
> wouldn't mind telling me what's involved
> in this method, I'd certainly appreciate
> it, and any other suggestions for
> handling two-sided boards, also.

Steps -

1, Drill hole with carbide drill
2, Place PCB on the anvil
3, Poke in and snap of rivet with bail
holding tool
4, Smack rivet hard with automatic punch
5, Solder both sides of hole
6, Suck out solder to leave hole empty

Only other tips I have for making double
sided boards (aside from layout tips) is
to build or buy a light box to help line
up your top and bottom photo masks. Put
a clear peice of plastic in place of the
blank PCB, put it on the light box and it
makes registering top and bottom an easy
task.