JPH09248756A - Polishing cloth - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce scattering in thickness, hardness, compression ratio and compression elastic ratio, make even polishing performance, and ensure a stable polishing effect by forming a layer of suede-like polyurethane foam resin on the flocked layer of substrate having a flocked structure. SOLUTION: A paint obtained by dissolving polyurethane resin in dimethyl formmamide(DMF) and coloring agent is applied by the knife overall method to the flocked surface of substrate where e.g. polyester short fiber having the thickess of 1.5 Denier and the length of 0.4mm is flocked on e.g. polyester filament fabric 1 having the thickness of 50 Denier through an acrylic resin adhesive 4 having thermosetting resin mixed therein by the electrostatical flocking mehtod. Then, the coasted urethane resin is solidified by immersing it in water to form a urethane resin layer 3 having a perpendicularly foaming structure. Thereafter, DMF is completely removed by washing it with water and dried, then the surface skin part of urethane layer 3 is grounded by the buff work to provide a suede-like polishing cloth.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to improvement of a polishing cloth used for precision polishing of semiconductor wafers and the like.

[0002]

2. Description of the Related Art Conventionally, for precision polishing of a semiconductor wafer such as a silicon wafer, a method of polishing with a polishing cloth while supplying a polishing liquid containing abrasive grains to a polishing surface has been used. In this case, a polishing cloth having a suede urethane foam resin layer formed on one surface of the nonwoven fabric is used.

[0003]

As described above, in a polishing cloth having a nonwoven fabric as a base material and a suede-like urethane foam resin layer formed on one surface thereof, the thickness, density, hardness, compressibility, and compression elastic modulus of the nonwoven fabric are The quality of the polishing cloth directly affects the quality of the polishing cloth, resulting in a variation in polishing performance. Further, when forming the suede-shaped polyurethane foam resin layer, variations in the thickness and density of the non-woven fabric affect the processing accuracy and cause variations in the urethane foam resin layer. The present invention provides a polishing cloth of uniform quality with no variation in polishing performance.

[0004]

In order to solve the above problems, the first invention of the present invention is to provide a cut pile woven fabric, and a woven fabric, paper,
Electrostatic flocking technique etc. via adhesive on one side of film etc.,
A suede-like foamed polyurethane resin layer was formed on the napped layer surface of a napped substrate on which napped layers were formed by short-fiber fluffing.

The second aspect of the present invention further provides a resin having a microporous structure,
The napped layer base material was filled by a processing method such as impregnation.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Since the first invention of the present invention is a base material composed of a napped layer that has been flocked by a cut pile or electrostatic flocking technique and a woven fabric, paper, film, etc. Since the fibers are extremely uniform and have little variation in thickness, density, hardness, etc., and the short fibers are uniformly formed in the vertical direction, a uniform compression rate and compression elastic modulus can be obtained. Further, in the process of forming the suede-like urethane foam resin layer, since the nap layer has a uniform structure, it becomes easy to make a stable and uniform suede-like urethane foam resin layer, and the quality of the base material becomes uniform, Due to the uniform suede-like foam structure, it is possible to obtain a polishing cloth having a stable polishing performance without variations.

Further, according to the second aspect of the present invention, by filling the base material having a napped layer with a resin having a microporous structure, the structure of the napped layer can be made denser and more uniform, so that the hardness and compressibility are improved. In addition, it is possible to improve the uniformity of the compression elastic modulus and to improve the uniformity and stability of the polishing performance. In addition, since the quality that affects the polishing performance such as hardness, compressibility, compression elastic modulus, etc. can be adjusted by the performance of the resin to be filled, the expansion ratio, the filling amount, etc., it provides an optimum polishing cloth for the work to be polished. You can

[0008]

【Example】

[Example 1] Polyester filament fabric (1) having a thickness of 50 denier (1) was mixed with 7% of thermosetting resin and polyester denier (2) having a thickness of 1.5 denier and a length of 0.4 mm by an electrostatic flocking technique. Via an acrylic resin adhesive (4), a flocked surface of a flocked substrate was coated with a paint prepared by dissolving 15% of polyurethane resin in 84% of dimethylformamide (hereinafter referred to as DMF) and 1% of a coloring agent by a knife over roll method. The urethane resin was applied and immediately immersed in water to solidify the applied urethane resin to form a urethane resin layer having a vertical foam structure. After the DMF was completely removed by washing with water and dried, the skin of the urethane layer was buffed to obtain a suede-like polishing cloth. As a result of measuring the quality of this polishing cloth, the thickness, hardness, compressibility,
The variation in compression modulus was very small compared to the conventional polishing cloth, and the sponge structure of the suede-like urethane resin layer was also very uniform.

Example 2 A paper (6) obtained by wet-making a polyester fiber was used, and a thickness of 1.0 denier and a length of 0.4 mm
The base material on which the polyester fiber (2) cut into
A polyurethane resin (5) having a microporous structure was formed by impregnating a resin solution containing 10% polyurethane resin, 89% DMF and 1% pigment, and immediately immersing in water, coagulating, washing with water and drying. Polyurethane resin 15%, DMF 83%, Pigment 1
%, A porosity control agent and other 1% coating material was applied to the flocked surface by the knife over roll method and immediately immersed in water to solidify the urethane resin to form a resin layer (3) having a vertical foam structure. . After washing with water and drying, buffing was applied to give a suede shape. As a result of measuring the quality of this polishing cloth, there is no variation in thickness, hardness, compression rate, and compression elastic modulus, and the structure of the suede-like polyurethane resin layer is very uniform, and there is no sponge structure or variation in opening diameter. was gotten.

[Embodiment 3] 75d / 36f warp yarns, 75d / 36f weft yarns, 70 weaving density warp / inch, 4 wefts
6 / inch, pile length 0.6mm polyester 10
Polyurethane resin 12 on 0% cut pile fabric (7)
%, DMF 87%, and pigment 1% were impregnated with the resin liquid, and the quality of the polishing cloth processed in the same process as in Example 2 was measured. As a result, a polishing cloth with very little variation in quality was obtained.

[0011]

The polishing cloth according to the first aspect of the present invention has little variation in thickness, hardness, compressibility and compression elastic modulus, has uniform polishing performance, and exhibits a stable polishing effect.

The second aspect of the present invention can further improve the uniformity of polishing performance according to the first aspect of the present invention. Further, it is possible to easily adjust the hardness, the compression rate, and the compression elastic modulus.

[Brief description of drawings]

FIG. 1 is a sectional view of a polishing cloth according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a polishing cloth according to a second embodiment of the present invention.

FIG. 3 is a sectional view of a polishing cloth according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 woven fabric 2 napped fiber 3 suede-like foamed polyurethane resin layer 4 adhesive 5 microporous resin 6 polyester paper 7 cut pile woven fabric

Claims (2)

[Claims] 1. A polishing cloth comprising a substrate having a napped structure and a suede-shaped polyurethane foam resin layer formed on the napped layer. 2. The polishing cloth according to claim 1, wherein a substrate having a napped structure is filled with a resin having a microporous structure.