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Topic: Via Rivets to fit 0.8mm drill hole, do they exist? (Read 1891 times) previous topic - next topic

Via Rivets to fit 0.8mm drill hole, do they exist?

Has anybody seen Via rivets which will fit a 0.8mm drill hole?

I bought a few which were advertised as 0.8mm, but they turned out to have an outer diameter around 0.88mm and so would require a drill hole of at least 0.9 really.

Searching for 0.7mm via rivets or smaller is not turning up anything at all, well not from the chinese sellers on ebay or taobao.  Perhaps they just don't exist at all?

Re: Via Rivets to fit 0.8mm drill hole, do they exist?

Reply #1
Multicore used to make a system that was used to repair plated-through-holes that had been damaged or ripped out by someone's carelessness.  It came with 3 different sizes - one of those was 0.8mm.  The bails (as they called them) were a solid rod of 63/37 solder that then had copper electroplated on top.  The rod was then scored at about 2.0 mm intervals to allow each segment to be snapped off inside the hole.

In use, you would drill out the hole with the supplied drill bit, set the PCB on top of a flat-surfaced metal rod, insert the bail and bend it sideways to snap a segment off inside the hole.  Then you would use a special impact tool to flatten the bail segment.

This causes the solder core to expand sideways and force the copper covering tightly against the inside of the hole.  Then - all you did was solder both the top and bottom of the trace, then use a vacuum desoldering tool to empty the hole.  Voila!  A nice, reliable plated-through-hole for you to put your component lead back into and solder.

I used to use the system back in the days when we were making our own double-sided circuit boards in-house.  Expensive and time-consuming - but it resulted in extremely reliable connections.

I have a link somewhere for a modern-day equivalent - but I'd have to go looking for it.

I still have the original Multicore system under my work bench - it gets used once or twice every few years.  I am getting low on bails, though.

dwayne

Re: Via Rivets to fit 0.8mm drill hole, do they exist?

Reply #2
Interesting although does sound like an expensive and time-consuming way than simple hollow rivets.

MegaUK ( http://megauk.com/through_hole_rivets.php ) and CircuitMedic ( http://www.circuitmedic.com/products/115-7000.shtml ) have something along the lines of what I want, but the price is not attractive (especially due to the crazy shipping cost they want to charge to send to me here in NZ).

I may have to just bite the bullet and move to a 0.9mm drill bit to accommodate the cheap via rivets :/