The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 25, 2012
Filed:
May. 01, 2009
Akinori Nishio, Ibaraki, JP;
Kazuyuki Kiuchi, Ibaraki, JP;
Akinori Nishio, Ibaraki, JP;
Kazuyuki Kiuchi, Ibaraki, JP;
Nitto Denko Corporation, Ibaraki-shi, JP;
Abstract
To provide a pressure-sensitive adhesive sheet which protects a ground, thin, fragile adherend from 'warping' and which can be removed from the fragile adherend after the completion of backgrinding without damaging and contaminating the fragile adherend. The pressure-sensitive adhesive sheetincludes a base layer A, a pressure-sensitive adhesive layer A, a base layer B, and a pressure-sensitive adhesive layer B arranged in this order, in which: the base layer A has a product of its Young's modulus at 25° C. and its thickness of 1.0×10to 4.0×10N/m and a product of its Young's modulus at 80° C. and its thickness of 2.8×10N/m or less; the pressure-sensitive adhesive layer A has a shear modulus at 80° C. of 0.2 MPa or less; the base layer B has a product of its Young's modulus at 25° C. and its thickness of smaller than that of the base layer A and has, upon 80° C. heating, a shrink percentage in MD and a shrink percentage in TD of each 20% or more; and the pressure-sensitive adhesive layer B has a Young's modulus at 80° C. of 10 MPa or more and an adhesive strength to a silicon wafer (180-degree peel at a tensile speed of 300 mm/min) of 0.2 N/10 mm or less.