Polishing pad

Patent metadata

Field	Value
Publication number	US-9707663-B2
Application number	US-201214001791-A
Country	US
Kind code	B2
Filing date	Jan 30, 2012
Priority date	Feb 28, 2011
Publication date	Jul 18, 2017
Grant date	Jul 18, 2017

Abstract

A polishing pad is provided with a compression elastic modulus of 0.17 MPa or more and 0.32 MPa or less produced by preparing a nonwoven fabric formed of bundles of ultrafine fibers with an average monofilament diameter of 3.0 μm or more and 8.0 μm or less, preparing a polishing pad base by impregnating the nonwoven fabric with a polyurethane based elastomer in an amount of 20 mass % or more and 50 mass % or less relative to the mass of the polishing pad base, and laminating the polishing pad base with a porous polyurethane layer containing wet-solidified polyurethane as primary component which has openings with an average opening diameter of 10 μm or more and 90 μm or less in its surface to serve as polishing surface layer.

First claim

The invention claimed is:

1. A polishing pad comprising a laminate including a polishing pad base and a porous polyurethane layer,
the polishing pad base comprising a nonwoven fabric impregnated with a polyurethane based elastomer, the nonwoven fabric being formed of bundles of ultrafine fibers with an average monofilament diameter of 3.0 μm or more and 8.0 μm or less and the polyurethane based elastomer being present in an amount of 20 mass % or more and 50 mass % or less relative to the mass of the polishing pad base, and
the porous polyurethane layer containing polyurethane as a primary component, wherein the porous polyurethane layer has openings with an average opening diameter of 10 μm or more and 90 μm or less in its surface and the compression elastic modulus is 0.17 MPa or more and 0.32 MPa or less.

2. A polishing pad as described in claim 1 wherein the ultrafine fiber's average monofilament diameter is 3.5 μm or more and 6.0 μm or less.

3. A polishing pad as described in either claim 1 or 2 wherein the polyurethane based elastomer accounts for 20 mass % or more and 30 mass % or less relative to the polishing pad base.

4. A polishing pad as described in claim 1 wherein the nonwoven fabric contains a nitrile butadiene based elastomer.

5. A polishing pad as described in claim 1 wherein the coefficient of variation of the average monofilament diameter of the ultrafine fibers in the nonwoven fabric is 10% or less.

Assignees

• Shiro Kuniyasu
• Wada Masaharu
• Kato Hiroyasu
• Nishimura Hajime
• Yanagisawa Satoshi
• Matsuzaki Yukihiro
• Toray Industries
• Toray Coatex Co Ltd

Inventors

• Shiro Kuniyasu
• Wada Masaharu
• Kato Hiroyasu
• Nishimura Hajime
• Yanagisawa Satoshi
• Matsuzaki Yukihiro

Classifications

• H10P52/00

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

• D06N3/14

  with polyurethanes · CPC title

• D06N2205/24

  Coagulated materials · CPC title

• D06N3/0004

  using ultra-fine two-component fibres, e.g. island/sea, or ultra-fine one component fibres (< 1 denier) · CPC title

• B24B37/24 Primary

  characterised by the composition or properties of the pad materials · CPC title