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

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Measling

Doug Hotalen

#10686

Measling | 12 July, 1999

I had parts replaced on SMT PWBs and the repair created measling defects. Reliability Question: Q1. Can measling be aggrevated or grow over time due to temperature cycling and moisture. Customer environment is -62C to +85C.

Thank you Doug Hotalen

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Earl Moon

#10687

Re: Measling | 12 July, 1999

| I had parts replaced on SMT PWBs and the repair created measling defects. | Reliability Question: | Q1. Can measling be aggrevated or grow over time due to | temperature cycling and moisture. Customer environment is | -62C to +85C. | | Thank you | Doug Hotalen | | Doug,

By your question, you realize meazling is thermally induced. Crazing is mechanically induced. Both look similar. Each may be negatively advanced, when beyond acceptable limits, when subjected to other thermal or mechanical stresses. This especially is true using MLB technology.

Earl Moon

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