Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.

"connector fell off"


"connector fell off" | 3 April, 2004

Customer returned a board and a 50 pin connector with .020" pitch that "fell off". after looking under a scope i can see the plating of the connector embedded in the solder. To me it looks like it broke off. Designer did not put the anchor pads on the board so that mechanical strength wasnt totally there. Quality manager for customer feels this should not have happened. The solder joints are not good. I looked at other location under a scope and joints look great. Profile is fine. If there is a problem what is it and how do I correct? Thanks for any help.

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"connector fell off" | 4 April, 2004

There certainly is a problem, but it�s unclear from your description whether the source of the problem is: * Design * Soldering * Component quality * A combination

Recognizing the SMT connectors see stress that other SMT component do not, you give the impression that the solder connection on this device is poor. You state that other soldered connections on the board appear to be good and the profile is fine. This leads us to think either: * Component has poor solderability * Profile was not fine

Please tell us about the appearance of the solder on: * Component * Pad on the board

Please tell us about the profile on the leads of the problem connector. [And how that profile differs from the profile on the components that soldered properly]

Tell us about the width and scope of this problem.

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| 4 April, 2004

I feel the solder connections were fine. The anchor pads for this device on the board are covered by solder mask. So the leads of the connector take all the stress. The component was broken off and under a scope you can see the plating of each lead embedded in the broken solder joint. Am I correct to say these were good solder connections that were mechanically broken with excessive force??? The other location with this component is on same edge of the board only a couple inches away. No evidence of poor solder quality there or on other boards. Not at work today so I will have to answer other questions you have tomorrow. Thanks for your help.

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"connector fell off" | 4 April, 2004

When you say, "you can see the plating of each lead embedded in the broken solder joint", we do not get the sense of a well soldered connection. * We don't expect to see [or make the distinction] of the plating from the connector in the solder. We expect to see one homogenious alloy. * When we rip a good solder connection apart, we usually see a rough surface on the lead and on the pad with each sharing a portion of the solder. The point this break occurs is along the CuSn intermetallic.

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