Solder joint reliability of a lead-less RF-transistor

Solder joint or board-level reliability is a very important parameter to consider when predicting the overall reliability of cellular phone systems. These predictions are often established by accelerated temperature cycling tests, along with an acceleration factor used in translating the test results to the actual field conditions. There are also a number of advanced theoretical methods to predict board-level reliability. In this study, the solder joint life of a lead-less RF-transistor mounted on a 2-layer PCB was investigated. Although the solder joint reliability of lead-less ceramic chip carriers has been studied for many years, this component is different because the package material is aluminum nitride and almost the entire bottom surface of the package is soldered to the board to achieve good thermal conduction. Also, the field condition is assumed to be somewhat unusual as it is dominated by power cycling.