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Tin whiskers on lead

2002

Hi,
I am a newly hired technician in a semicon company. I just want to know more about tin whiskers? What is the main cause of tin whiskers? And how to eliminate this problem?

Thanks!

Samantha Lopez
- Manila, Philippines

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2002

It has been years since I dealt with this but I recall that tin whisker occur under a compressively stress situation. Worse if the bath is fouled with epoxy. This also occurs in zinc and cad. Occurrance can occur years later. To deter this effect I think the US military spec called for a 3% min of co-deposited lead. At the time I pushed for a tin/bismuth deposit for environmental reasons but was ruled down at Mil-Spec review. Collins radio spells out a tin/bismuth. Dig deep and you will find better answers better than I have.

Jon Quirt
- Fridley, Minnesota