New video! We’re back with a bonus round! Did you think the previous episode was the last? We’re (once again) talking test jigs in this episode of The Factory. We’ve designed our board, panelised it for production but we still need to test every unit that comes off the assembly line! We work with a standard test jig at Core Electronics, and in this episode we come up with a testing philosophy and jig daughterboard.
The Factory | Design A Product With Us Part 6: Test Jigs & Quality Control - YouTube
This video can also be viewed here
3 Likes
Hi Michael
Good thinking using wired diode or and and gates to bulk test output connections. Also have a simple Pass/Fail result as it would probably cost more to fix the board to component level than discarding faulty boards.
To me connector longevity would be my main concern as they will have a finite life. The test cables etc have to be spot on or you are likely to get problems that are not really there. This is always a problem.
A practical example of this was while I was working I had several test cables with BNC connectors. It was soon realised that most of the cumulative damage to these connections occurred while doing up and releasing the knurled retainer. As this retainer does just that, retains and stops the connector falling out and forms no part in the electrical connection it was simply removed. That way it could be plugged in and out many more times with minimal strain on the whole thing thus prolonging life.
Cheers Bob
4 Likes
Good points @Robert93820 - yes we’ve encountered the cycle-limit on a few bits of test hardware before.
On this jig it’s really just the 3-pin headers that pose a cycle-limit risk.
The PiicoDev cables and connectors are good for testing several thousand units before they get too loose. We haven’t worked with USB-C on a test jig before but I’m sure it’s similar.
For the 3-pin headers we can always replace just the header components to avoid remaking the whole daughter board. That ought to be repeatable at least a couple of times before the accumulated wear is too great.
3 Likes
Hi Michael
Yes it would be the female connectors on the daughter board which would be of concern. Repeated insertion of the relatively larger header pins expands them after a few insertions but as this is going to be always the larger pin they will probably last quite a while. It seems that some trouble can occur if trying to use a smaller pin after some use of the larger header pins.
It is a pity though that something like a pogo pin with a concave head to capture the end of the header pins could not be used. I think that would solve the pin connection dilemma nicely.
Cheers Bob
1 Like
