Influence of mobile ion in organic material used in semiconductor devices

Kapton tape is often used for co-planarity of inner metal lead frame parts in the packaging of semiconductor components. It is made of organic material known as high temperature insulating tape. In this paper, the increment of leakage current in a packaged component that is caused by a Kapton tape was studied. The leakage measurement on Kapton tape was done using simple testing instruments such as source meter, micro prober and temperature controlled hot plate. The different leakage current characteristics were investigated on high temperature, test duration and length of the Kapton tape. According to the measured leakage current on various dependencies, it is suggested the leakage is due to mobile ion in Kapton tape. Various analysis techniques were able to identify the mobile ion was Sodium ions in the glue of the Kapton tape. Based on the observation, a model explaining the Sodium mobile ions failure mechanism in the Kapton tape was established. The deployment of leakage test can be applied to test incoming lead frame material. The test set up did not require expensive tester equipment and manufactured devices. It could also be transferred as new outgoing quality check mainly for lead frame suppliers.