Accelerated Reliability Test Method of Thermal Cycle Life for Solder Joints of Electronic Devices
Yasumi UEGAI and Shuichi TANI
Abstract:Thermal cycle tests for solder joints of electronic devices are generally performed to investigate their reliability under field service (design) conditions. It is important to clear a relationship between an accelerated test condition and a service condition and to determine a practical accelerated test condition. The relationship between an accelerated test condition and a service condition is explained by use of the solder joint fatigue curve. An accelerated reliability test condition is shown taking account of several factors such as a number of test samples, strain ranges of solder joints under accelerated test temperatures conditions, standard variations of fatigue life of solder joints, reliability and confidence level of devices under service conditions. Moreover, the cases that the standard deviation of fatigue life is known or unknown are investigated. A specific analytical and experimental result for single outline packages is shown. Key Words:Solder joints, Thermal fatigue, Thermal cycle test, Reliability, Confidence level, Electronic devices