Most of the engineering interest in second level packaging of electric system goes into electric circurity and thermal cooling issues. However, in addition to thermally induced stresses, electronic system often experience vibration environment. These vibration occurs during shipping, handling, as well as during operation. To assure high product reliability, it is necessary to provide estimating tools of fatigue life to the designer, as early as possible in the design process.
For this purpose an automated fatigue testing system was developed. The fatigue testing machine utilized the electromagnetic force as an actuator. Data acquisition system was also developed for the fatigue test of the electronic board. The fixture for the specimen was designed to be suitable to measure the fatigue life of a typical module/lead/card electronic system subjected to vibration. The vibration load was generated by the electromagnetically actuated fatigue test machine.
An experimental method was developed to measure the change in electrical resistance in the lead, which is used to detect the fatigue failure of the interconnection. The changes in electrical resistance measured in the leads after repetitively flexural configurations represent the structural weakening of the leads due to fatigue.
A relationship between the loading force and fatigue life of high cycle region was discussed for the lead of spider gullwing type surface-mounted component.