Accession Number : ADP005196

Title :   Aspects of Surface Mounted Chip Carrier Solder Joint Reliability,

Corporate Author : AEROJET ELECTROSYSTEMS CO AZUSA CA

Personal Author(s) : Ellis,Herbert B.

Report Date : FEB 1987

Pagination or Media Count : 31

Abstract : When successful commercial surface mounted technology (SMT) was applied to military environments with ceramic chip carriers, unsatisfactory solder joint life was experienced. The problem of how SMT could be successfully implemented for military requirements was addressed. The nature of the leadless solder joint fatigue strains and addresses was reviewed. A set of design requirements was established as a baseline for the analysis. Matching the coefficient of expansion of the board and chip carrier does not necessarily prevent fatigue failure as the analysis showed relatively high stresses and the presence of reciprocating strain. A statistical method was outlined for determining if a solder joint design would meet an established fatigue criteria from a set of fatigue failure test data. The relatively high stresses and the presence of reciprocating strain can be reduced by the use of compliant leads on the ceramic chip carriers. An analysis of the compliant J lead indicated it could be a viable solution. In an exploratory 2000 thermal cycle fatigue test (-55 C to +125 C) no solder joint failures were experienced with a 68 lead ceramic chip carrier with compliant J leads on a glass epoxy board. (Author)

Descriptors :   *SOLDERED JOINTS, *RELIABILITY(ELECTRONICS), COMMERCIAL EQUIPMENT, LEAD WIRES, CHIPS(ELECTRONICS), MILITARY APPLICATIONS

Subject Categories : Mfg & Industrial Eng & Control of Product Sys
      Couplers, Fasteners, and Joints
      Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE