| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a polishing pad allowing the improvement in the flatness of a polishing object thinned and embrittled for a long period. <P>SOLUTION: This polishing pad 10 includes a polyurethane foam 2 having a polishing surface P for polishing the surface of the polishing object and a cushion layer 3 arranged on a surface side opposite to the polishing surface P. The polyurethane foam 2 is made by wet film forming. The cushion layer 3 is composed by adhering two sheets of polyurethane foams 3a and 3b made by wet film forming. In the cushion layer 3, a compression rate is set in the range of 30 to 75%, and has 3 to 5 times as thick as the polyurethane foam 2. When an operation for eliminating pressure is repeated after pressure is applied in the cushion layer 3, the maintenance ratio of a compressive elastic modulus after repeating the operation at least two hundred times in relation to the first compressive elastic modulus becomes 70% or more. In even low pressure polishing, the polishing surface P follows the surface of the polishing object. <P>COPYRIGHT: (C)2010,JPO&INPIT |
