HALT/HAST

Topic #: A2001-167
Sponsor: Army
Status: Phase II Completed
TRL: 8
Need: To determine reliability of electronic components utilizing lead-free solder.

Lead based solders have been used for decades to make conductive and structural connections in electronic assemblies. Whole manufacturing technologies are based on the melt, flow and wetting characteristics of these materials and establishing new solder platforms requires substantial and pervasive changes in the industry. As industry moves away from the use of lead in electronic assemblies, the development of qualification standards and reliability models for lead free solders and conductive adhesives is needed to ensure continued performance reliability. TRI/Austin has developed and validated life accelerating procedures and reliability models that can be used as a “standard of evaluation” for lead free solders, making it possible to compare them with each other and with well established tin-lead solder.

  • Validation of these procedures and models was obtained by accelerated life testing of materials in TRI/Austin’s laboratories using multiple and variable stress factors.
  • A reliability test protocol was standardized for use with existing and emerging solders and adhesives that remains valid as components, board assemblies and materials evolve.
  • A comprehensive reliability model was developed for each specific alloy and adhesive relative to standard lead eutectic solder. Forced ranking of the best performing solders and adhesives in terms of long term reliability, based upon laboratory testing performed in Phase II.