Fatigue of Advanced In-Situ Composite Solders

Abstract

Solder Joints used in surface mount technology experience thermomechanical fatigue due to the mismatches in coefficients of thermal expansion of the electrical component, the printed circuit board, and the solder itself, which during thermal cycles causes the solder Joint to undergo shear strains. The purpose of this study was to examine and explain the thermomechanical fatigue damage mechanisms of various types of solder compositions. Shear, creep, low cycle fatigue, and thermomechanical fatigue tests were conducted in this research. The development of cracks through heterogeneously coarsened, Sn-enriched bands was observed in Sn-Pb eutectic and solid solution strengthened alloys failed in thermomechanical fatigue. The dominant damage mechanism for these alloys was determined to be dislocation climb. Dispersion strengthening inhibited heterogeneous coarsening, and resulted in solders with greater thermomechanical fatigue lifetimes.

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Document Details

Document Type
Technical Report
Publication Date
Apr 20, 1998
Accession Number
ADA345807

Entities

People

  • K. L. Jerina
  • S. M. Sastry

Organizations

  • University of Washington

Tags

Communities of Interest

  • Advanced Electronics
  • Energy and Power Technologies
  • Human Systems

DTIC Thesaurus Topics

  • Alloys
  • Circuit Boards
  • Composite Materials
  • Creep
  • Creep Tests
  • Dispersions
  • Electronic Components
  • Failure Mode And Effect Analysis
  • Fatigue Tests (Mechanics)
  • Grain Size
  • Materials
  • Materials Testing
  • Mechanical Properties
  • Mechanics
  • Metal Matrix Composites
  • Physical Properties
  • Solid Solutions

Fields of Study

  • Materials science

Readers

  • Electrical Engineering
  • Powder metallurgy of Titanium alloys.
  • Structural Health Monitoring of Composite Structures.