MLCC - Chip blackening

Hello. I have a customer that continues to have problems with their bulk cassette feeder. The customer is complaining about shorted parts that result from bulk cassette feeding operations. They are quick to claim that the failure is related to the MLCC quality.

In short, failure analysis revealed the short is from Sn material that has flaked away from the terminal electrode. SEM revealed evidence of abrasion on the terminal electrode and Sn deposits on the capacitor body.

I have had a hard time finding any information regarding this phenomena, which I believe is related to the bulk cassette hopper condition and duration of parts in the hopper / feeding mechanism. This is supported by poor PM of the bulk cassette system and our internal FA.

Any advice on how to correct this problem or experience(s) with the cause is greatly appreciated.

Kind Regards,

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