Contributions of Stress and Oxidation on the Formation of Whiskers in Pb-free Solders
Abstract
Understanding the environmental factors influencing formation of tin whiskers on electrodeposited lead free, tin coatings over copper (or copper containing) substrates is the topic of this study. An interim report summarized initial observations as to the role of stress and oxide formation on whisker growth. From the initial results, two main areas were chosen to be the focus of additional research: the demonstration of effects of elastic stress state in the nucleation of whiskers and the confirmation of the effect of oxygen content in the formation of whiskers. Different levels of elastic stress were induced with the incorporation of a custom designed fixture that loaded the sample in a four-point bending configuration and were maintained in an environmental chamber under conditions deemed favorable for whisker growth. The effects of oxygen content were studied by aging substrates in gas vials of varying absolute pressure and different oxygen partial pressure.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 29, 2016
- Accession Number
- AD1024408
Entities
People
- A. J. Duncan
- Elizabeth N. Hoffman
Organizations
- Savannah River National Laboratory