We has banned manual soldering for leadless chip capacitors. Years ago we
experienced exactly the same problem. Microsectioning revealed that cracks are
formed across several layers of the interleaved electrodes. Even bigger problem
was that the cracked capacitor would not be detected in the initial test. After
operating for a while, metal migrated across the crack and shorted the layers.
We glad the problem was caught in burn-in rather than in the field. The shorted
capacitor burnt some of our assemblies badly.

Manual soldering was not the only cause of capacitor cracking. AVX and Kemet
published some articles about precautions in design and assembly processes.

K.K. Chin
Artesyn Technologies,
Fremont, CA

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