An Interconnect Stress Testing (IST) and Thermal Cycle Test (TCT) approach on printed circuit boards reliability

This paper describes the procedure and the results of a comprehensive test series to clarify relationships between different accelerated lifetime tests for PCBs (IST, online-hard and -soft TCTs in both cases with real-time resistance measurement and with classic micro-section assessment). The strong influence of base material properties on reliability has been demonstrated. The influence of copper plating properties on the cycle capability was also discussed. Acceleration factors between IST, hard and soft TCTs were determined, however, they have high uncertainties. Furthermore, a qualitative correlation between resistance measurement and detailed failure assessment at micro-sections was illustrated.