Methodology for a highly accelerated solder joint reliability test

A thermo-mechanical deflection system (TMDS) test method has been developed for evaluating the fatigue performance of solder joints in printed circuit board (PCB) assemblies. The TMDS test imparts cyclic twisting deflections on an assembled PCB test vehicle which is tested under controlled isothermal conditions in a thermal chamber. Tests were conducted at various angles of twist and isothermal conditions at 100/spl deg/C and 25/spl deg/C. Failure analysis using SEM showed that the solder joint failure for the TMDS test is comparable to the failure mechanisms for accelerated thermal cycling (ATC) test failures for solder joints. Weibull failure distribution plots for TMDS and ATC tests were compared and a scale factor (SF) was used to correlate the test results.