Polishing pad

Patent metadata

Field	Value
Publication number	US-9358661-B2
Application number	US-201414537497-A
Country	US
Kind code	B2
Filing date	Nov 10, 2014
Priority date	Aug 28, 2006
Publication date	Jun 7, 2016
Grant date	Jun 7, 2016

Abstract

A polishing pad capable of maintaining a high level of dimensional stability during absorption of moisture or water includes a polishing layer including a polyurethane foam having fine cells, wherein the polyurethane foam includes a cured product of a reaction of an isocyanate-terminated prepolymer (a), a polymerized diisocyanate, and a chain extender, and the isocyanate-terminated prepolymer (a) includes an isocyanate monomer, a high molecular weight polyol (a), and a low molecular weight polyol. A method for manufacturing such a polishing pad includes mixing a first component containing an isocyanate-terminated prepolymer with a second component containing a chain extender and curing the mixture to form a polyurethane foam. The pad so made is used in the manufacture of semiconductor devices.

First claim

The invention claimed is:

1. A polishing pad, comprising a polishing layer comprising a polyurethane foam having fine cells,
the polyurethane foam comprising a cured product of a reaction of an isocyanate-terminated prepolymer (A), a polymerized diisocyanate, and a chain extender chain extender,
the isocyanate-terminated prepolymer (A) being a reaction product of isocyanate monomers, a high molecular weight polyol (a), and a low molecular weight polyol,
wherein the polymerized diisocyanate is added in an amount of 5 to 20 parts by weight, based on 100 parts by weight of the isocyanate-terminated prepolymer (A), and
the high molecular weight polyol (a) is a polyether polyol with a number average molecular weight of 500 to 5,000, and the isocyanate monomers are toluene diisocyanate and dicyclohexylmethane diisocyanate,
wherein the polymerized diisocyanate is selected from the group consisting of a biuret of hexamethylene diisocyanate, an isocyanurate of hexamethylene diisocyanate, or a combination thereof.

2. The polishing pad according to claim 1 , wherein the polyurethane foam has an average cell diameter of 20 to 70 μm and shows a dimensional change of 0.8% or less when it absorbs water.

3. The polishing pad according to claim 1 , wherein the polyurethane foam has an Asker D hardness of 45 to 65 degrees.

4. The polishing pad according to claim 1 , wherein the polyurethane foam contains 0.05 to 10% by weight of a nonionic silicone surfactant.

Assignees

• Toyo Tire & Rubber Co
• Rohm & Haas Elect Mat

Inventors

• Nakai Yoshiyuki
• Kimura Tsuyoshi
• Kazuno Atsushi
• Ogawa Kazuyuki
• Shimomura Tetsuo

Classifications

• H10P52/00

  Grinding, lapping or polishing of wafers, substrates or parts of devices · CPC title

• C08G18/4854

  Polyethers containing oxyalkylene groups having four carbon atoms in the alkylene group · CPC title

• C08G18/724

  Combination of aromatic polyisocyanates with (cyclo)aliphatic polyisocyanates · CPC title

• C08G18/14

  Manufacture of cellular products · CPC title

• C08G18/6674

  with compounds of group C08G18/3203 · CPC title