Correlating Interconnect Stress Test and Accelerated Thermal Cycling for Accessing the Reliabilities of High Performance Printed Circuit Boards

Understanding the failure mechanism of a plated through hole (PTH) is essential for a complete picture of their life span, and hence for the continued electronic reliability prediction and development of high performance printed circuit boards. This paper presents the efficacy of establishing a correlation between interconnect stress test (IST) and accelerated thermal cycling (ATC) data on standard high performance coupons. In accord with the observation in PTH micro-sectioning, a PTH failure mechanism is proposed based on the thermal expansion-induced shearing at the copper-resin interface. The PTH cycle to failure data from the two methodologies, IST and ATC, are correlated. In terms of the glass transition temperature, a linear relationship exists between two different data sets. It is also demonstrated that the base material thermal property and PTH sizes are the two essential factors determining the reliability of a PTH. Furthermore, a life stress model is created to predict the life time of a coupon at a particular temperature level.