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Posts: 59 | Thanked: 28 times | Joined on Oct 2009
#1034
Originally Posted by Texrat View Post
I realize it's easy to miss explanations in a big thread like this so I'll repeat (with additional detail):

- no such thing as "solder being too strong". If done properly solder joints actually form an alloy between the solder and two connected materials and is by design meant to be as resistant to breakage as possible.

- in the expected life of these products, there should be no "expected hard failure mode" for this connector. Soft failure is a different story, and would involve damage to the internals (like breaking the plastic tab inside).

- the problem here is not solder but the copper plating. It is coming free of the printed circuit board (PCB) much too easily.

The root cause fault is most likely with the PCB manufacturer, not Nokia (materials suppliers are supposed to guarantee their products' quality). However, I'm still of the opinion Nokia made a bad decision going with a surface mount connector. Even with copper plating issues, we would probably never have seen this defect with a through-hole mount.
Hmm although some copper came off in my case some places on the connector had no solder at all, which as you correctly say, shouldn't really happen, so I think its a bad solder which resulted on more stress on the copper which then came off the board in some places. I should have got those pictures then I could highlight this. Its in the post now, as I thought Nokia might want to inspect the connector to devise the failure mode, probably not economically viable to do that though.

I agree with you that it appears to be a marginal design which has highlighted this minor manufacturing flaw had they beefed the mounting up a bit it probably wouldn't matter if the solder wasn't quite perfect (or the copper pads if that is the problem). It is always gonna be hard to get a big bit of metal like that to solder perfectly to the board, it should have been secured some other way. I am sure it won't be just Nokia suffering from problems mounting these MicroUSB connectors, expect to see problems with many manufacturers as they all move to the european standard, most will surface mount there connectors like this.

Open source connector design anybody?