Recently, DISCO has received more requests to process hollow wafers for CMOS (complementary metal oxide semiconductor) image sensors and MEMS (micro electro mechanical systems). In order to meet such needs, DISCO is engaged in development of hollow wafer grinding. Here, our progress will be explained.
Features of Hollow Wafer Grinding
When grinding a hollow wafer, a load concentrates near the boundary between the hollow section and wafer holding area and such condition tends to cause cracking. Especially at a location where the saw mark and its boundary are parallel, cracking is very easy to occur.
Based on the characteristics mentioned above, DISCO is engaged in research and development of grinding conditions and wheels that can prevent cracking of hollow wafers.
The newly-developed wheel enables processing with less damage and less load than the conventional wheels. This realizes a thinning process of hollow wafers having higher quality.
Note: Suitable grinding conditions and feasible finishing thickness vary depending on the size and height of the hollow section as well as how the wafer is bonded. For details, please contact DISCO Application R&D Dept.