US 12,170,204 B2
Processing method of wafer, protective sheet, and protective sheet laying method
Kazuma Sekiya, Tokyo (JP)
Assigned to DISCO CORPORATION, Tokyo (JP)
Filed by DISCO CORPORATION, Tokyo (JP)
Filed on Jul. 21, 2021, as Appl. No. 17/381,784.
Claims priority of application No. 2020-128468 (JP), filed on Jul. 29, 2020; and application No. 2021-063429 (JP), filed on Apr. 2, 2021.
Prior Publication US 2022/0037160 A1, Feb. 3, 2022
Int. Cl. H01L 21/304 (2006.01); H01L 21/02 (2006.01); H01L 21/78 (2006.01)
CPC H01L 21/304 (2013.01) [H01L 21/02013 (2013.01); H01L 21/78 (2013.01); H01L 2224/85207 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A protective sheet laid on a surface of a wafer, the protective sheet comprising:
a first sheet that is thermocompression-bonded directly to the surface of the wafer by heating, wherein the first sheet is a polypropylene sheet;
a second sheet that is laid on the first sheet and has fluidity due to the heating; and
a third sheet that is laid on the second sheet and is allowed to keep flatness even with the heating;
wherein the first sheet, the second sheet and the third sheet are thermocompression bonded to become a three layer protective sheet.