300mm Wafer-Level Image Sensor Packaging

The image sensor market is still showing s tremendous market growth due to applications in consumer electronics, medical, automotive and communication. For a lot of new applications the image sensor packaging is in fact the enabling key technology. The introduction of wafer level packaging a couple of years ago allowed the cost reduction necessary for high volume consumer electronics. Innovative packaging concepts with TSVs and thin dies enable unmatched form factor. Currently scaling image sensor manufacturing and packaging to 300mm is the next big step forward in cost reduction. Wafer level image sensor packaging requires capping of the sensor wafer with a glass wafer. This heterogeneous integration of silicon and glass results in a variety of challenges like thermal expansion mismatch and bow and warp of the wafer stack. In this paper Tessera's OptiML Micro Via Pad technology for image sensors will be described with a special emphasis on equipment and process technology. Wafer encapsulation, via format...