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:
Feb. 05, 2019
Filed:
Mar. 17, 2015
Fujibo Holdings, Inc., Chuo-ku, Tokyo, JP;
Kouki Itoyama, Tokyo, JP;
Daisuke Takahashi, Saijo, JP;
FUJIBO HOLDINGS, INC., Chuo-Ku, Tokyo, JP;
Abstract
Provided is a polishing pad which is capable of providing a high flatness to a polishing workpiece and suppressing the formation of scratches, and a method therefor. The polishing pad comprises a foamed urethane sheet on the surface which includes closed cells and open cells and which satisfies the following requirements: (1) an open cell ratio is 20-80 vol % where the total volume of closed cells and open cells is taken as 100 vol %, (2) the ratio [tan δ (wet/dry) ratio] of a loss factor tan δ in a water-absorption state to that in a dry state is 1.3-1.7, the loss factors being measured according to JIS K7244-4 with an initial load of 20 g at a measuring frequency of 1 Hz at a temperature of 26° C. in a tensile mode over a strain range from 0.01 to 0.1%, and (3) the Shore DO hardness according to ASTM D2240 is 60-80.