Novel wafer level package technology studies for image sensor devices

Wafer level package for optical image sensor devices are known to be processed by re-routing of the bond pads to the back side of the chip, through (T) contacts located at the die edges. Bond pad back via contact wafer level packaging technology has been developed by Schott Electronic Packaging GmbH, Germany, which is proven to be with a number of advantages over the mechanically processed (T) contact wafer level packages. Direct contact of the bond pads from the back side of the chip offers much shorter transmission paths to the board assemblies, thus allowing faster signal speed, efficient thermal conduction and many added advantages. Also, the new technology offers area contacts with in the seal ring/isolation boundary of the device, there-by providing much higher performance for the packaged devices. The reliability of this new WLP technology has been demonstrated by testing the same for various reliability test conditions as per JEDEC/JIS standards. This paper discusses the process technology and reliability tests/results carried out on a consumer application chip, namely image sensor device.