Intermetallic Growth at the Interface Between Copper and Bismuth-Tin Solder

Abstract

Tin-bismuth alloys have been proposed as alternatives to lead containing solders for interconnection and packaging applications. Consequently, the interface between copper metallizations and bismuth-tin solders needs to be evaluated with respect to brittle intermetallic formation. In the binary Bi-Sn alloys both the Cu6Sn5 and Cu3Sn intermetallic phases were found at the Cu/ solder interface after exposure at 250 deg C, 300 deg C, and 350 deg C. Bi-Sn-Sb alloys were also studied and in addition to the aforementioned intermetallic compounds Cu-Sb intermetallics were found. Kinetic growth laws have been established for the intermetallics at various temperatures and solder compositions. In addition, bulk samples of the solder were tested in compression in the furnace-cooled and quenched condition. Quenching appeared to result in higher strain rate dependence. Furthermore the tin-rich compositions were more strain rate sensitive than the bismuth-rich composition.

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 1993
Accession Number
ADA275716

Entities

People

  • Fred O. Vollweiler

Organizations

  • Naval Postgraduate School

Tags

Communities of Interest

  • Advanced Electronics
  • Biomedical

DTIC Thesaurus Topics

  • Alloys
  • Chemistry
  • Circuit Boards
  • Electronics
  • Elements
  • Intermetallic Compounds
  • Joining
  • Materials
  • Materials Science
  • Materials Testing
  • Measurement
  • Mechanical Properties
  • Mechanics
  • Metals
  • Packaging
  • Physical Properties
  • Strain Rate

Fields of Study

  • Materials science

Readers

  • Integrated Circuit Design and Technology.
  • Powder metallurgy of Titanium alloys.
  • Thin Film Deposition Science.