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Title: Fatigue and reliability in near eutectic solder alloys for spacecraft applications. Ph.D. Thesis

Abstract

A complex interaction of creep and cyclic fatigue causes failures to occur in soldered structures used for interconnection in electronic assemblies. It is essential to understand the material properties, microstructural characteristics and alloy variations, which contribute to the fatigue process, in order to design, test and manufacture a reliable electronic product. Microstructural coarsening contributes to the creep behavior and mechanical properties in near eutectic alloys. Using a simple model and test method developed for this research, the activation energy of the coarsening process was measured to be 0.42 +/- 0.09 eV. The influence of silver alloying and cerium processing on microstructure and fatigue performance were studied using statistical experimental designs. Silver alloyed near eutectic solder (Sn62) will provide an improvement in fatigue life attributed to a more creep resistant microstructure. Although cerium processing did have some impact on microstructure, there was no statistically significant effect on fatigue life under the test conditions. In addition to understanding microstructure and alloying effects, adequate fatigue models are needed to predict the life of a soldered assembly. Strain energy partitioning techniques, coupled to finite element modeling, appear to be the best alternative.

Authors:
Publication Date:
Research Org.:
Johns Hopkins Univ., Baltimore, MD (United States)
OSTI Identifier:
264006
Report Number(s):
N-96-23554; NIPS-96-08277
TRN: 9623554
Resource Type:
Thesis/Dissertation
Resource Relation:
Other Information: TH: Ph.D. Thesis; PBD: Jan 1994
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; EUTECTICS; CREEP; FATIGUE; TIN BASE ALLOYS; SOLDERING; ACTIVATION ENERGY; FINITE ELEMENT METHOD; MATHEMATICAL MODELS; MICROSTRUCTURE; SILVER ADDITIONS; CERIUM ADDITIONS

Citation Formats

Evans, J W. Fatigue and reliability in near eutectic solder alloys for spacecraft applications. Ph.D. Thesis. United States: N. p., 1994. Web.
Evans, J W. Fatigue and reliability in near eutectic solder alloys for spacecraft applications. Ph.D. Thesis. United States.
Evans, J W. 1994. "Fatigue and reliability in near eutectic solder alloys for spacecraft applications. Ph.D. Thesis". United States.
@article{osti_264006,
title = {Fatigue and reliability in near eutectic solder alloys for spacecraft applications. Ph.D. Thesis},
author = {Evans, J W},
abstractNote = {A complex interaction of creep and cyclic fatigue causes failures to occur in soldered structures used for interconnection in electronic assemblies. It is essential to understand the material properties, microstructural characteristics and alloy variations, which contribute to the fatigue process, in order to design, test and manufacture a reliable electronic product. Microstructural coarsening contributes to the creep behavior and mechanical properties in near eutectic alloys. Using a simple model and test method developed for this research, the activation energy of the coarsening process was measured to be 0.42 +/- 0.09 eV. The influence of silver alloying and cerium processing on microstructure and fatigue performance were studied using statistical experimental designs. Silver alloyed near eutectic solder (Sn62) will provide an improvement in fatigue life attributed to a more creep resistant microstructure. Although cerium processing did have some impact on microstructure, there was no statistically significant effect on fatigue life under the test conditions. In addition to understanding microstructure and alloying effects, adequate fatigue models are needed to predict the life of a soldered assembly. Strain energy partitioning techniques, coupled to finite element modeling, appear to be the best alternative.},
doi = {},
url = {https://www.osti.gov/biblio/264006}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Sat Jan 01 00:00:00 EST 1994},
month = {Sat Jan 01 00:00:00 EST 1994}
}

Thesis/Dissertation:
Other availability
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