Toyo Tire Rubber Co., Ltd.

Junji Hirose

Takeshi Fukuda

Masato Doura

Kenji Nakamura

Akinori Sato

Tsuguo Watanabe

Yoshiyuki Nakai

Tsuyoshi Kimura

Satoshi Maruyama

Disclosed is a method for production of a laminate polishing pad which comprises a reduced number of steps and is excellent in productivity rate, and which causes no detachment between a polishing layer and a cushion layer and can prevent the groove clogging caused by a slurry or the like. Also disclosed is a laminate polishing pad produced by the method. A method for production of a laminate polishing pad, comprising the steps of: preparing a cell-dispersed urethane composition by a mechanical frothing process; ejecting the cell-dispersed urethane composition onto a cushion layer continuously while feeding the cushion layer; curing the cell-dispersed urethane composition while controlling the thickness of the composition evenly to form a polishing layer made of a polyurethane foam, thereby producing a long laminate sheet; and cutting the long laminate sheet.

Method for production of a laminate polishing pad

A method for manufacturing a polishing pad, which may be laminated, with a small number of manufacturing steps, high productivity and no peeling between a polishing layer and a cushion layer includes preparing a cell-dispersed urethane composition by a mechanical foaming method; continuously discharging the cell-dispersed urethane composition onto a face material, while feeding the face material; laminating another face material on the cell-dispersed urethane composition; curing the cell-dispersed urethane composition, while controlling its thickness to be uniform, so that a polishing layer including a polyurethane foam is formed; cutting the polishing layer parallel to the face into two pieces so that two long polishing layers each including the polishing layer and the face material are simultaneously formed; and cutting the long polishing layers to produce the polishing pad.

Method for manufacturing polishing pad

A polishing pad of excellent durability and adhesion between the polishing layer and the base material layer includes a polishing layer arranged on a base material layer, wherein the polishing layer includes a thermosetting polyurethane foam having roughly spherical interconnected cells having an average cell diameter of 20 to 300 &#x3bc;m. The polyurethane foam includes an isocyanate component and an active hydrogen-containing compound as starting material components, and the active hydrogen-containing compound includes 30 to 85% by weight of a high-molecular-weight polyol having 2 to 4 functional groups and a hydroxyl value of 20 to 100 mg KOH/g.

Polishing pad and a method for manufacturing the same

A method for manufacturing a polishing pad that has high level of optical detection accuracy and is prevented from causing slurry leak from between the polishing region and the light-transmitting region includes preparing a cell-dispersed urethane composition by a mechanical foaming method; placing a light-transmitting region at a predetermined position on a face material or a belt conveyor, continuously discharging the cell-dispersed urethane composition onto part of the face material or the belt conveyor where the light-transmitting region is not placed; placing another face material or belt conveyor on the discharged cell-dispersed urethane composition; curing the cell-dispersed urethane composition to form a polishing region including a polyurethane foam, so that a polishing sheet is prepared; applying a coating composition containing an aliphatic and/or alicyclic polyisocyanate to one side of the polishing sheet and curing the coating composition to form water-impermeable film; and cutting the polishing sheet.

Polishing pad

A method for manufacturing a polishing pad that has a high level of optical detection accuracy and is prevented from causing slurry leak from between the polishing region and the light-transmitting region includes preparing a cell-dispersed urethane composition by a mechanical foaming method; placing a light-transmitting region at a predetermined position on a face material or a belt conveyor, continuously discharging the cell-dispersed urethane composition onto a part of the face material or the belt conveyor where the light-transmitting region is not placed; placing another face material or belt conveyor on the discharged cell-dispersed urethane composition; curing the cell-dispersed urethane composition to form a polishing region including a polyurethane foam, so that a polishing sheet is prepared; applying a coating composition containing an aliphatic and/or alicyclic polyisocyanate to one side of the polishing sheet and curing the coating composition to form a water-impermeable film; and cutting the polishing sheet.

Process for manufacturing polishing pad

A method for manufacturing a polishing pad prevents slurry leaks and provides a pad that can be used to provide high optical detection accuracy. The method for manufacturing a polishing pad includes forming a groove for injecting a light-transmitting region forming material on the back surface of a polishing layer; injecting the light-transmitting region forming material into the groove and curing the material to form a light-transmitting region; and buffing the front surface of the polishing layer to expose the light-transmitting region on the front surface.

Polishing pad manufacturing method

Provided herein is a process for producing a layered sheet. The process involves preparing a cell dispersed urethane composition by a mechanical foaming method. The cell dispersed urethane composition is applied to a base material sheet and cured to produce a polyurethane foam layer of uniform thickness. A releasing sheet may be utilized to make the thickness of the polyurethane foamed layer uniform. Also, provided herein is a layered sheet produced by the above process. The polyurethane foamed layer may have spherical fine cells having an average cell diameter of 20 to 300 &#x3bc;m. The polyurethane foamed layer may have a specific gravity of 0.2 to 0.5. The polyurethane foamed layer may also have a Asker C hardness of 10 to 50 degrees.

Layered sheets and processes for producing the same

A method for manufacturing a polishing pad containing substantially spherical cells and having high thickness accuracy includes preparing a cell-dispersed urethane composition by a mechanical foaming method; continuously discharging the cell-dispersed urethane composition from a single discharge port to a substantially central portion in the width direction of a face material A, while feeding the face material A; laminating a face material B on the cell-dispersed urethane composition; then uniformly adjusting the thickness of the cell-dispersed urethane composition by thickness adjusting means; curing the cell-dispersed urethane composition with the thickness adjusted in the preceding step without applying any additional load to the composition so that a polishing sheet including a polyurethane foam is formed; and cutting the polishing sheet.

Process for producing polyurethane foam

A polishing pad of excellent durability and adhesion between the polishing layer and the base material layer includes a polishing layer arranged on a base material layer, wherein the polishing layer includes a thermosetting polyurethane foam having roughly spherical interconnected cells having an average cell diameter of 20 to 300 &#x3bc;m The polyurethane foam includes an isocyanate component and an active hydrogen-containing compound as starting material components, and the active hydrogen-containing compound includes 30 to 85% by weight of a high-molecular-weight polyol having 2 to 4 functional groups and a hydroxyl value of 20 to 100 mg KOH/g.

A polishing pad of excellent durability has a polishing layer is arranged on a base material layer, and the polishing layer comprises a thermosetting polyurethane foam having roughly spherical interconnected cells with an average cell diameter of 35 to 300 &#x3bc;m.

To provide a polishing pad which is insusceptible to clogging of groove with abrasive particles and grinding dusts during polishing, and leads to little decrease in polishing rate even after long-term continuous use. A polishing pad of the present invention has a polishing layer formed of polyurethane resin foam having fine-cells, and asperity structure formed in a polishing surface of the polishing layer, and is featured in that the polyurethane resin foam is a reaction cured product between isocyanate-terminated prepolymer containing high-molecular-weight polyol component and isocyanate component, and a chain extender, and contains a silicon-based surfactant having combustion residue of not less than 8 wt %.

A polishing pad provides excellent optical detection accuracy properties over a broad wavelength range (particularly at the short-wavelength side). A method for manufacturing a semiconductor device includes a process of polishing the surface of a semiconductor wafer with this polishing pad. The polishing pad has a polishing layer containing a polishing region and a light-transmitting region, wherein the light-transmitting region includes a polyurethane resin having an aromatic ring density of 2 wt % or less, and the light transmittance of the light-transmitting region is 30% or more in the overall range of wavelengths of 300 to 400 nm.

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Osaka, Japan

Junji Hirose