Track 3 Session 11
10:30 to 11:30 a.m. Thursday June 11, 2009

Solder-Joint Reliability…Requirements, Predictions, and Qualification

Fatigue failure of solder joints, a critical electronics reliability factor, remains a dominant element in new applications and advanced hardware deployment. This presentation provides guidance towards: 1) establishing the total t-cycle requirements for new applications based on the thermal environments of each segment of the mission as well as statistical specifications, 2) guidance on predictions of projected life of known and new hardware based on materials and geometrical inputs, and 3) recommendations on accelerated aging, testing methods and acceptance thresholds for qualification. Numerical methods are outlined to show how much life will be consumed in each phase of the mission. This presentation shows examples of the expected lifetimes of a wide range of SMT hardware, in go or no-go status, in several typical mission environments, as a format for application guide constructions. Subjective personal bias as well as the need for esoteric software skills are eliminated; common-sense intuitive physics-based reasoning and procedures are provided.

Key Words: Solder Joints, Reliability, Thermal-Cycle Fatigue, Qualification Testing, Life-test Statistics

Tom Clifford
TJB Associates
Lockheed Martin (Retired)
Half Moon Bay, California