US 12,286,569 B2
Adhesive sheet
Shusaku Ueno, Ibaraki (JP); Takumi Yutou, Ibaraki (JP); and Takamasa Hirayama, Ibaraki (JP)
Assigned to NITTO DENKO CORPORATION, Ibaraki (JP)
Appl. No. 17/269,580
Filed by NITTO DENKO CORPORATION, Ibaraki (JP)
PCT Filed Aug. 19, 2019, PCT No. PCT/JP2019/032257
§ 371(c)(1), (2) Date Feb. 19, 2021,
PCT Pub. No. WO2020/049985, PCT Pub. Date Mar. 12, 2020.
Claims priority of application No. 2018-166993 (JP), filed on Sep. 6, 2018.
Prior Publication US 2021/0309889 A1, Oct. 7, 2021
Int. Cl. C09J 7/38 (2018.01); C09J 11/08 (2006.01); C09J 125/10 (2006.01); C09J 153/02 (2006.01); H01L 21/304 (2006.01); H01L 21/683 (2006.01)
CPC C09J 7/38 (2018.01) [C09J 11/08 (2013.01); C09J 125/10 (2013.01); C09J 153/02 (2013.01); H01L 21/304 (2013.01); H01L 21/6836 (2013.01); C09J 2203/326 (2013.01); C09J 2301/124 (2020.08); C09J 2301/312 (2020.08); C09J 2301/408 (2020.08); C09J 2301/412 (2020.08); C09J 2301/502 (2020.08); C09J 2400/24 (2013.01); C09J 2453/00 (2013.01); H01L 2221/68318 (2013.01); H01L 2221/68327 (2013.01); H01L 2221/6834 (2013.01); H01L 2221/68381 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A pressure-sensitive adhesive sheet, comprising a pressure-sensitive adhesive layer, and a light-peel layer in the pressure-sensitive adhesive layer,
wherein the pressure-sensitive adhesive layer contains:
a pressure-sensitive adhesive containing a base polymer;
a surfactant having a linear or branched alkyl group having 5 to 20 carbon atoms; and
a foaming agent having a foaming temperature of 90° C. or more,
wherein the light-peel layer is formed in the pressure-sensitive adhesive layer through segregation of the surfactant,
wherein the base polymer contained in the pressure-sensitive adhesive is a styrene-based elastomer, and
wherein the pressure-sensitive adhesive sheet has, when a pressure-sensitive adhesive surface thereof is bonded to a silicon chip, a shear adhesive strength of 1.0 MPa or more under an ambient temperature of 25° C., and a shear adhesive strength of 0.2 MPa to 5 MPa under an ambient temperature of 80° C.