| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a base film of a pressure-sensitive adhesive sheet capable of suppressing dimpling and cracking of a wafer by dispersing grinding stress applied to a step on a wafer surface. <P>SOLUTION: There is provided a base film 22 comprising (A) a step absorption layer which is 100-400 μm thick and has a storage elastic modulus of 0.2-6.0 MPa at 23°C and (B) a layer made of thermoplastic resin. In a reverse-surface grinding process in which a top-surface side of the wafer having a device region where a plurality of devices are sectioned with streets and an outer peripheral surplus region surrounding the device region is held on a holding table of a grinding device so as to form a recessed part by grinding a region 16 of a reverse surface of the wafer which corresponds to the device region and also to form a ring-shaped reinforcement part 17 on an outer peripheral side of the recessed part, the base film is used for the pressure-sensitive adhesive sheet stuck on the wafer surface. <P>COPYRIGHT: (C)2013,JPO&INPIT |
