Maxima-SPRT methodology for health monitoring of contact resistance in IC sockets

The evaluation of integrated circuit sockets for quality, reliability, and/or prognostic applications is performed with accelerated tests and stress conditions that are defined by industry standards. These methods typically use threshold values to detect degradation and failures of the electrical interconnect. However, this approach does not consider the physics of failure of the component under test and is not sensitive enough to detect small changes in behavior. This paper presents a physics of failure based methodology that, combined with a sequential probability ratio test, overcomes the issues of the traditional approach. This new approach, called Maxima-SPRT, enables early detection of degradation and provides the information needed for the successful implementation of prognostic tools. The method is validated using an elastomer socket, a daisy chain package, and a test board assembly.