HARMONIC VIBRATION TESTING OF ELECTRONIC COMPONENTS ATTACHED TO PRINTED WIRING BOARDS WITH SAC305 AND EUTECTIC SnPb SOLDER

Abstract

Ball grid arrays attached to printed wiring boards with conventional tin-lead solder (63/37) and one of the leading lead-free tin-silver-copper solders (SAC305) were tested at high and low load levels of harmonic vibration. Leadless chip resistors attached to printed wiring boards with conventional tin-lead solder and lead-free solders (SAC105 and SAC305, and tin-nickel-copper, SN100C) were tested at low levels of harmonic vibration. The tests were conducted near the natural frequency of the assemblies to accelerate testing and to generate high cycle fatigue failures in a reasonable amount of time. The results showed that there are nearly negligible differences in the high cycle fatigue life between the SnPb and SAC305 solders. SN100C and SAC105 were less durable. A master durability plot was generated for SAC305 and SnPb to confirm the negligible-difference between the solders. A safe area was defined be used as a design goal for survivablity for circuit board design.