Re: [CAD_CAM_EDM_DRO] Re: Through hole plating

Going way back in my memory, rivets used to be intentionally "split" length wise. They were made from a folded strip of foil
instead of a tube.

The reason was to avoid the problems mentioned. A tubular rivet forms a mechanical joint on top and a soldered one on the bottom.
That is because the solder will not wick up and over the top of the rivet and solder it to the top layer.

A split washer will wick up solder and through the crack spread out on top and therefor also solder it to the top.

I know one very large manufacturer that even eyeletted printed through holes to increase the reliability although that was a lot of
years ago.

I suspect it will be hard to find split rivets but that's the way to go.

By the way, the problem with home made boards is not adding jumpers or wires between top and bottom, it is soldering the topside
under connectors and sockets.

Bertho Boman
Vinland Corporation
====================

Hugh Prescott wrote:

> Not to throw cold water on rivets & eylets for plated through holes but
>
> They have a high failure rate that is highly intermittant and very hard to
> find.
>
> Some years ago several major medical X-Ray manuf. used eyelets.
> intermittant city, a 1-2 degree temp change caused problems. The fix was to
> use a wire through the eyelet and solder each end to the trace.
>
> The problem was that the epoxy glass PC board was expanding and contracting
> at a diferent rate than the eylete.
>
> Nothing wrong with jumpers look at common comercial electronics, lots of
> single sided PCB's with lots of jumpers.