Publication Date

2008-03-18

Availability

Open access

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PHD)

Department

Industrial Engineering (Engineering)

Date of Defense

2008-03-04

First Committee Member

Shihab Asfour - Committee Chair

Second Committee Member

Sohyung Cho - Committee Member

Third Committee Member

Moiez Tapia - Committee Member

Fourth Committee Member

Arzu Onar - Outside Committee Member

Abstract

Existing risk simulations make the assumption that when a free tin whisker has bridged two adjacent exposed electrical conductors, the result is an electrical short circuit. This conservative assumption is made because shorting is a random event that has a currently unknown probability associated with it. Due to contact resistance electrical shorts may not occur at lower voltage levels. In these experiments, the effect of varying voltage on the breakdown of the contact resistance which leads to a short circuit was studied. From this data, the probability of an electrical short was estimated, as a function of voltage, given that a free tin whisker has bridged two adjacent exposed electrical conductors. Also, three tin whiskers grown from the same Space Shuttle Orbiter card guide used in the aforementioned experiment were cross-sectioned and studied using a focused ion beam (FIB). The rare polycrystalline structure seen in the FIB cross section was confirmed using transmission electron microscopy (TEM). The FIB was also used to cross section two card guides to facilitate the measurement of the grain size of each card guide's tin plating to determine its finish.

Keywords

Empirical Model

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