JP2016140938A - Polishing pad and method for manufacturing polishing pad - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polishing pad and a method for manufacturing the same which solve such a problem that in manufacture of a polishing pad in which polishing abrasive grains are stuck to a base material formed of a material having voids, when a non-woven fabric is impregnated with a binder in which the abrasive grains are dispersed, much grains result in being sunk and polishing efficiency deteriorates; and have much abrasive grains existing in a polishing surface and are excellent in the polishing efficiency.SOLUTION: A polishing pad 10 has a base material 11 and a polishing layer 12. The base material is a non-woven fabric impregnated with a synthetic resin 112, and has voids. The polishing layer is formed by applying an abrasive grain-containing solution containing a curable resin 121 and abrasive grains 122 onto the base material, and curing the curable resin.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a polishing pad in which abrasive grains are adhered to a substrate made of a material having voids, and a method for manufacturing the polishing pad.

  Some polishing pads used for lapping (rough polishing) or polishing of semiconductor materials, metal materials, and difficult-to-cut materials have a structure in which abrasive grains are attached to a substrate such as a nonwoven fabric. The abrasive grains are attached to the base material by a synthetic resin or the like impregnated in the base material. When the polishing pad comes into contact with the object to be polished, the abrasive grains present on the surface (polishing surface) of the polishing pad come into contact with the object to be polished and polishing is performed.

  For example, Patent Document 1 discloses a polishing sheet in which a nonwoven fabric is impregnated with a binder in which abrasive grains are dispersed. Patent Document 2 discloses a polishing tape in which abrasive grains are adhered on a film substrate by an electrostatic spray method.

JP 2008-194761 A JP 2002-172563 A

  However, in the polishing sheet described in Patent Document 1, most of the abrasive grains sink into the nonwoven fabric, exist on the surface of the polishing sheet, and there are few abrasive grains that contribute to polishing. Moreover, since the surface of an abrasive grain will be in the state coated with the binder, a grinding | polishing target object and an abrasive grain do not contact directly. For this reason, there exists a problem that polishing efficiency is small. Further, the polishing tape described in Patent Document 2 has a problem that it is difficult to uniformly apply abrasive grains on a film substrate.

  In view of the circumstances as described above, an object of the present invention is to provide a polishing pad having a large number of abrasive grains on the polishing surface and excellent in polishing efficiency, and a method for manufacturing the same.

In order to achieve the above object, a polishing pad according to an embodiment of the present invention includes a base material and a polishing layer.
The base material is made of a material having voids.
The polishing layer is formed by applying an abrasive-containing solution containing a curable resin and abrasive grains to the substrate and curing the curable resin.

  According to this configuration, the curable resin contained in the abrasive-containing solution soaks into the base material made of a material having voids, and the abrasive grains remain on the base material surface. For this reason, a large number of abrasive grains are distributed on the surface of the substrate, and a polishing pad having high polishing characteristics can be obtained. In addition, the abrasive grains do not enter the substrate, and generation of abrasive grains that do not contribute to polishing can be prevented.

  The space of the base material may be provided in such a size that the curable resin before curing can pass therethrough and the abrasive grains cannot pass therethrough.

  According to this configuration, the curable resin can be infiltrated into the base material, while the abrasive grains can be more reliably prevented from entering the base material.

  The base material may be a nonwoven fabric impregnated with a synthetic resin.

  According to this configuration, the curable resin contained in the abrasive-containing solution can be infiltrated into the gap formed by the nonwoven fabric and the synthetic resin. The synthetic resin impregnated in the nonwoven fabric holds the nonwoven fabric and imparts appropriate elasticity to the polishing pad.

  The substrate may be a nonwoven fabric made of polyester fibers impregnated with polyurethane resin.

  According to this configuration, a polishing pad having high polishing characteristics can be obtained.

  The base material may include a resin sheet made of a synthetic resin and a nonwoven fabric laminated on the resin sheet, and the abrasive-containing solution may be applied to the nonwoven fabric.

  According to this configuration, it is possible to soak the curable resin contained in the abrasive-containing solution into the voids formed by the nonwoven fabric. The resin sheet supports the nonwoven fabric and imparts appropriate elasticity to the polishing pad.

The resin sheet is made of polyethylene terephthalate resin,
The nonwoven fabric may be a nonwoven fabric made of polyethylene terephthalate fibers.

  According to this configuration, a polishing pad having high polishing characteristics can be obtained.

  The curable resin may include a phenol resin and an epoxy resin.

  According to this configuration, it is possible to cure the curable resin contained in the abrasive-containing solution applied to the substrate by heating.

  The abrasive-containing solution may further contain a solvent.

  According to this configuration, it is possible to adjust the viscosity of the abrasive-containing solution with a solvent so that the viscosity easily penetrates into the substrate.

In order to achieve the above object, a method for producing a polishing pad according to an aspect of the present invention includes:
Prepare an abrasive-containing solution containing a curable resin and abrasive grains,
Applying the abrasive-containing solution to a substrate made of a material having voids,
The curable resin contained in the abrasive-containing solution is cured.

  According to this configuration, the curable resin contained in the abrasive grain-containing solution is contained in the base material made of a material having voids, and the abrasive grains remain on the base material surface. For this reason, a large number of abrasive grains are distributed on the surface of the substrate, and a polishing pad having high polishing characteristics can be manufactured. Further, most of the abrasive grains do not enter the inside of the base material, and generation of abrasive grains that do not contribute to polishing can be prevented.

  As described above, according to the present invention, it is possible to provide a polishing pad having a large number of abrasive grains on the polishing surface and excellent in polishing efficiency, and a method for manufacturing the same.

1 is a perspective view of a polishing pad according to a first embodiment of the present invention. It is sectional drawing of the same polishing pad. It is sectional drawing of the base material with which the polishing pad is provided. It is a schematic diagram of the abrasive grain containing solution used for manufacture of the polishing pad. It is a schematic diagram which shows the manufacturing method of the same polishing pad. It is a schematic diagram which shows the manufacturing method of the same polishing pad. It is a perspective view of the polishing pad which concerns on the 2nd Embodiment of this invention. It is sectional drawing of the same polishing pad. It is sectional drawing of the base material with which the polishing pad is provided. It is a schematic diagram of the abrasive grain containing solution used for manufacture of the polishing pad. It is a schematic diagram which shows the manufacturing method of the same polishing pad. It is a schematic diagram which shows the manufacturing method of the same polishing pad. 2 is an SEM image of a cross section of a polishing pad according to Example 1. FIG. It is a SEM image of the surface of the polishing pad. 4 is a SEM image of a cross section of a polishing pad according to Example 2. It is a SEM image of the surface of the polishing pad. 4 is a SEM image of a cross section of a polishing pad according to Comparative Example 1. It is a SEM image of the surface of the polishing pad. 4 is a SEM image of a cross section of a polishing pad according to Comparative Example 1. It is a SEM image of the surface of the polishing pad.

  In the present invention, the polishing pad includes a grinding wheel such as a scrub pad or a roll type used for cleaning, in addition to those mounted on a polishing apparatus.

(First embodiment)
A polishing pad according to a first embodiment of the present invention will be described.

[Configuration of polishing pad]
FIG. 1 is a perspective view of a polishing pad 10 according to this embodiment, and FIG. 2 is a cross-sectional view of the polishing pad 10. As shown in FIG. 2, the polishing pad 10 includes a base material 11 and a polishing layer 12.

The base material 11 consists of a material which has a space | gap. FIG. 3 is a cross-sectional view of the substrate 11. As shown in the figure, the substrate 11 can be a nonwoven fabric 112 impregnated with a synthetic resin 111. Examples of the method for producing the nonwoven fabric 112 include a spun bond method, a thermal bond method, a chemical bond method, a needle punch method, and a spun lace method. In this embodiment, since the nonwoven fabric 112 functions also as a cushion layer, a thick nonwoven fabric is preferable and the needle punch method was used. 100~5000g / ^{m 2} as the basis weight of the nonwoven fabric 112, preferably 0.05~0.60g / cm ³ as the density, and more preferably 0.10~0.50g / cm ^3. Moreover, 0.01-10 dtex can be used as the fineness of the fiber used for a nonwoven fabric. When the density is the same, the void unit can be adjusted by changing the number of fibers per unit volume by changing the fineness of the fibers. The voids of the nonwoven fabric 112 can be adjusted by the basis weight, density, and fiber fineness, and the porosity is preferably about 45 to 95%.

  In the present invention, the void is a continuous space inside the base material, which allows the curable resin applied to the surface of the base material to penetrate into the base material, and the abrasive grains applied to the base material surface. It makes it possible to keep the majority on the substrate surface. If it is such a space | gap, the magnitude | size will not be ask | required, For example, it represents with the diameter of the inscribed circle in one cross section of a space | gap, and it is preferable that it is 1-100 micrometers. If the gap is smaller than 1 μm, it is difficult for the curable resin to penetrate into the nonwoven fabric 112, and if the gap is larger than 100 μm, the abrasive grains may pass through the gap.

  The synthetic resin 111 is for bonding fibers constituting the nonwoven fabric 112 and is partially impregnated between the fibers.

  By impregnating the non-woven fabric 112 with the synthetic resin 111, the synthetic resin 111 holds the non-woven fabric 112 and gives the polishing pad 10 elasticity suitable for polishing, and at the same time, the porosity and the void size of the base material 11 can be controlled. It is. The synthetic resin 111 may be a polyurethane resin, for example, and the nonwoven fabric 112 may be a nonwoven fabric made of polyester fibers, for example.

  Moreover, the base material 11 is not restricted to said thing, What is necessary is just a material which has a moderate space | gap. For example, it may be a non-woven fabric, a woven fabric or a knitted fabric which is made of a foamable material such as a foamed polyurethane foam having continuous foaming, or is not impregnated with a synthetic resin. The thickness of the substrate 11 is not particularly limited, and can be about several mm to several tens mm.

  Hereinafter, as shown in FIG. 3, one surface of the substrate 11 is referred to as a front surface 11a, and the opposite surface is referred to as a back surface 11b. The front surface 11a is a surface on which the polishing layer 12 is formed, and the back surface 11b may be provided with an adhesive tape or an adhesive layer (not shown) if necessary.

  The polishing layer 12 is formed on the surface 11a of the substrate 11, and includes a curable resin 121 and abrasive grains 122 as shown in FIG. As will be described later, the polishing layer 12 is formed by applying an abrasive-containing solution containing a curable resin 121 and abrasive grains 122 to the surface 11 a and curing the curable resin 121.

  The curable resin 121 fixes the abrasive grains 122 to the base material 11. The curable resin 121 may be any resin that can be cured, and may be a thermosetting resin, a photocurable resin, a two-component mixed curable resin, or the like. For example, examples of the synthetic resin include phenolic resins, epoxy resins, urethane resins, acrylic resins, and PVA (polyvinyl alcohol), and examples of natural resins include glue. As the curable resin 121, these enumerated resins may be used, or a mixture thereof may be used.

  When the curable resin 121 is applied to the surface 11 a as an abrasive grain-containing solution, the curable resin 121 soaks into the base material 11 and a part thereof is contained in the base material 11. The depth at which the curable resin 121 penetrates is not particularly limited, and may penetrate to the back surface 11b.

The abrasive grains 122 are fixed on the substrate 11 with a curable resin 121. The abrasive grains 122 are particles having high hardness, and can be, for example, abrasive grains made of diamond. In addition, the abrasive grains 122 are abrasive grains made of silicon carbide (SiC), alumina (Al ₂ O ₃ ), zirconia (ZrO ₂ ), zirconium silicate (ZrSiO ₄ ), cerium oxide (CeO ₂ ), or the like. It may be. The grain size of the abrasive grains is not particularly limited, but a size that does not pass through the voids of the nonwoven fabric 112 is preferable, and specifically, 0.5 to 50 μm is preferably used.

  The polishing pad 10 has the above configuration. As shown in FIG. 1, the polishing pad 10 has a disk shape, and its size (diameter) is determined according to the size of the polishing apparatus, and can be, for example, about several cm to 1 m in diameter. Further, the shape of the polishing pad 10 is not limited to a disk shape, but may be a rectangular shape, a polygonal shape, a belt-like shape that can be attached to a roller, or the like.

[Production method of polishing pad]
A method for manufacturing the polishing pad 10 will be described.

  As shown in FIG. 4, an abrasive grain-containing solution S is prepared. The abrasive grain-containing solution S includes a resin mixed solution R and abrasive grains 122. The resin mixed solution R includes the curable resin 121 and a solvent. The solvent is used to adjust the viscosity of the abrasive-containing solution S. For example, water, isopropyl alcohol, isobutyl alcohol, 1-butanol, 2-butanol, isopentyl alcohol, methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, Tert-butyl acetate, sec-butyl acetate, isopentyl acetate, 2-methoxyethyl acetate, 2-ethoxyethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, 1,3-dioxolane, 1,4-dioxane, ethylene glycol monomethyl ether, ethylene glycol Monoethyl ether, ethylene glycol dimethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, diethylene glycol monomethyl ether, and the like are used. The viscosity of the abrasive-containing solution is adjusted so that the time for the resin mixed solution R to soak into the nonwoven fabric 112 is shorter than the time until the solvent evaporates and the curing starts. Specifically, the viscosity is preferably about 0.1 Pa · s to 100 Pa · s. Moreover, you may add dispersing agents, such as surfactant, in order to improve the dispersibility of the abrasive grain in an abrasive grain containing solution as needed.

  Subsequently, as shown in FIG. 5, the abrasive-containing solution S is applied to the surface 11 a of the substrate 11. The coating method is not particularly limited, and various coating methods such as a doctor blade method, a roll coating method, a spin coating method, a gravure coating method, a screen printing method, and a rotary printing method are applicable. After application, as shown in FIG. 6, a part of the resin mixed solution R soaks into the base material 11, and the abrasive grains 122 remain on the surface 11a.

  Subsequently, volatile components such as a solvent contained in the abrasive grain-containing solution S are removed by heating, decompression, etc., and the abrasive grain-containing solution S is dried. After drying, the curable resin 121 contained in the abrasive grain-containing solution S is cured. For example, when the curable resin 121 is a thermosetting resin, it can be cured by heating the abrasive-containing solution S. Moreover, when the curable resin 121 is a photocurable resin, it can be cured by irradiating the abrasive-containing solution S with light. As the curable resin 121 is cured, the polishing layer 12 is formed on the substrate 11 (see FIG. 2).

  The polishing pad 10 can be manufactured as described above.

[Effect of polishing pad]
As described above, in the polishing pad 10, the abrasive grains 122 are present on the surface 11 a (polishing surface) of the base material 11 and are hardly present inside the base material 11. For this reason, when polishing is performed using the surface 11a as the polishing surface, the abrasive grains 122 come into contact with the object to be polished, and the abrasive grains effectively function as an abrasive. The shavings generated by the polishing are accommodated in the substrate 11 and remain. As a result, the adverse effect of scratching (scratches and reduction in polishing efficiency) can be reduced.

  If the abrasive grains 122 are present inside the base material 11, they are not exposed to the polishing surface and do not function as an abrasive. Further, the polishing pad 10 is not a type of polishing pad that can use a new surface for polishing even if it is worn by polishing, and is replaced when the initial polishing layer 22 is worn. Therefore, the abrasive grains 122 present inside the substrate 11 are wasted.

  The abrasive grains 122 are diamond abrasive grains, for example, and are generally expensive. In the polishing pad 10 according to the present embodiment, it is possible to expose almost the entire amount of the abrasive grains 122 added to the abrasive grain-containing solution S to the polishing surface, so that the necessary amount of the abrasive grains 122 can be reduced. Is possible. That is, the manufacturing cost of the polishing pad 10 can be reduced without reducing the polishing performance.

(Second embodiment)
A polishing pad according to a second embodiment of the present invention will be described.

[Configuration of polishing pad]
FIG. 7 is a perspective view of the polishing pad 200 according to the present embodiment, and FIG. 8 is a cross-sectional view of the polishing pad 20. As shown in FIG. 8, the polishing pad 20 includes a base material 21 and a polishing layer 22.

  The base material 21 is made of a material having voids. FIG. 9 is a cross-sectional view of the base material 21. As shown in the figure, the base material 21 is configured by laminating a resin sheet 211 and a nonwoven fabric 212.

  The resin sheet 211 is a sheet made of synthetic resin. The resin sheet 211 can be made of polyethylene terephthalate resin or polyurethane resin. Further, the resin sheet 211 may be made of another synthetic resin. The thickness of the resin sheet 211 is not particularly limited, and can be about several mm to several tens of mm.

  Unlike the first embodiment, the nonwoven fabric 212 was manufactured using a spunlace method. Since the resin sheet 211 functions as a cushion layer, the nonwoven fabric 212 can be as thin as 0.03 to 0.30 mm. The nonwoven fabric 112 can be a nonwoven fabric made of, for example, polyethylene terephthalate fiber.

  By laminating the resin sheet 211 on the nonwoven fabric 212, the resin sheet 211 supports the nonwoven fabric 212, and the polishing pad 10 can be given elasticity suitable for polishing. The base material 21 is not limited to the above, and may be any material having an appropriate gap. For example, it may be a foamed material such as foamed polyurethane foam, or a nonwoven fabric or woven fabric impregnated with a synthetic resin.

  Hereinafter, as shown in FIG. 9, the surface of the base material 21 on the nonwoven fabric 212 side is referred to as a front surface 21a, and the surface on the resin sheet 211 side is referred to as a back surface 21b. The front surface 21a is a surface on which the polishing layer 22 is formed, and the back surface 21b may be provided with an adhesive tape or an adhesive layer (not shown) as required.

  The polishing layer 22 is formed on the surface 21a of the substrate 21, and includes a curable resin 221 and abrasive grains 222 as shown in FIG. As will be described later, the polishing layer 22 may be formed by applying an abrasive-containing solution containing a curable resin 221 and abrasive grains 222 to the surface 21a and curing the curable resin 221.

  The curable resin 221 fixes the abrasive grains 222 to the base material 21. The curable resin 221 only needs to be curable as in the first embodiment, and may be a thermosetting resin, a photocurable resin, a two-component mixed curable resin, or the like. . For example, examples of the synthetic resin include phenolic resins, epoxy resins, urethane resins, acrylic resins, and PVA (polyvinyl alcohol), and examples of natural resins include glue. As the curable resin 121, these enumerated resins may be used, or a mixture thereof may be used.

  When the curable resin 221 is applied to the surface 21 a as an abrasive grain-containing solution, the curable resin 221 soaks into the nonwoven fabric 212 and a part thereof is contained in the nonwoven fabric 212. The depth at which the curable resin 221 penetrates is not particularly limited, and may penetrate into part of the resin sheet 211 or the back surface 21b.

The abrasive grains 222 are fixed on the nonwoven fabric 212 with a curable resin 221. The abrasive grains 222 are high hardness particles as in the first embodiment, and may be abrasive grains made of diamond, for example. In addition, the abrasive grains 222 are abrasive grains made of silicon carbide (SiC), alumina (Al ₂ O ₃ ), zirconia (ZrO ₂ ), zirconium silicate (ZrSiO ₄ ), cerium oxide (CeO ₂ ), or the like. It may be. The grain size of the abrasive grains is not particularly limited, but a size that does not pass through the voids of the nonwoven fabric 212 is preferable, and specifically, 0.5 to 50 μm is preferably used.

  The polishing pad 20 has the above configuration. As shown in FIG. 7, the polishing pad 20 has a disk shape, and its size (diameter) is determined according to the size of the polishing apparatus and can be, for example, about several cm to 1 m in diameter. Further, the shape of the polishing pad 20 is not limited to a disk shape, but may be a rectangular shape, a polygonal shape, a belt-like shape that can be attached to a roller, or the like.

[Production method of polishing pad]
A method for manufacturing the polishing pad 20 will be described.

  As shown in FIG. 10, an abrasive grain-containing solution S is prepared. The abrasive grain-containing solution S includes a resin mixed solution R and abrasive grains 222. The resin mixed solution R includes the curable resin 221 and a solvent. The solvent is used to adjust the viscosity of the abrasive-containing solution S. For example, water, isopropyl alcohol, isobutyl alcohol, 1-butanol, 2-butanol, isopentyl alcohol, methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, Tert-butyl acetate, sec-butyl acetate, isopentyl acetate, 2-methoxyethyl acetate, 2-ethoxyethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, 1,3-dioxolane, 1,4-dioxane, ethylene glycol monomethyl ether, ethylene glycol Monoethyl ether, ethylene glycol dimethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, diethylene glycol monomethyl ether and the like are used. The viscosity of the abrasive-containing solution is adjusted so that the time for the resin mixed solution R to soak into the nonwoven fabric 112 is shorter than the time until the solvent evaporates and the curing starts. Specifically, the viscosity is preferably about 0.1 Pa · s to 100 Pa · s. Moreover, you may add dispersing agents, such as surfactant, in order to improve the dispersibility of the abrasive grain in an abrasive grain containing solution as needed.

  Subsequently, as shown in FIG. 11, the abrasive grain-containing solution S is applied to the surface 21 a of the substrate 21. The coating method is not particularly limited, and various coating methods such as a doctor blade method, a roll coating method, a spin coating method, a gravure coating method, a screen printing method, and a rotary printing method are applicable. After the application, as shown in FIG. 12, a part of the resin mixed solution R soaks into the nonwoven fabric 212, and the abrasive grains 222 remain on the surface 21a.

  Subsequently, volatile components such as a solvent contained in the abrasive grain-containing solution S are removed by heating, decompression, etc., and the abrasive grain-containing solution S is dried. After drying, the curable resin 221 contained in the abrasive grain-containing solution S is cured. For example, when the curable resin 221 is a thermosetting resin, the abrasive grain-containing solution S can be cured by heating. Moreover, when the curable resin 121 is a photocurable resin, it can be cured by irradiating the abrasive-containing solution S with light. The polishing layer 22 is formed on the substrate 21 by the curing of the curable resin 221.

  The polishing pad 20 can be manufactured as described above.

[Effect of polishing pad]
Similar to the first embodiment, in the polishing pad 20, the abrasive grains 222 are present on the surface 21 a (polishing surface) of the substrate 21, and hardly exist inside the substrate 21. For this reason, when polishing is performed using the surface 21a as the polishing surface, the abrasive grains 222 come into contact with the object to be polished, and the abrasive grains effectively function as an abrasive. The shavings generated by the polishing are accommodated in the substrate 21 and remain. As a result, the adverse effect of scratching (scratches and reduction in polishing efficiency) can be reduced.

  As described above, in the polishing pad 20, almost the entire amount of the abrasive grains 222 added to the abrasive grain-containing solution S can be exposed to the polishing surface, so that the required amount of the abrasive grains 222 can be reduced. It is. In other words, the manufacturing cost of the polishing pad 20 can be reduced without reducing the polishing performance.

  The polishing pad which concerns on the Example and comparative example of this invention was produced, and it observed with the scanning electron microscope (SEM).

  A phenol resin (PS-F (manufactured by J-Chemical)) and an epoxy resin (K-1430 (manufactured by J-Chemical)) are mixed at a weight ratio of 1: 1 to obtain a resin solution, and the resin solution and the solvent are mixed. (IPA) was mixed at a weight ratio of 9: 1 to prepare a resin mixed solution. Diamond abrasive grains (TMD-S 20-25 (particle size: about 18 μm, manufactured by Trustwell)) were added to the resin mixed solution to prepare an abrasive-containing solution. The amount of abrasive grains added was 40 wt% with respect to the resin weight.

  The above abrasive-containing solution was applied to the following various substrates and heated at 70 ° C. for 30 minutes to remove the solvent. Subsequently, the resin was cured by heating at 130 ° C. for 20 minutes to cause a crosslinking reaction.

Example 1
A base material having the structure described in the first embodiment was used. That is, a polyester non-woven fabric impregnated with polyurethane resin was used as a base material, and an abrasive-containing solution was applied to the surface of the base material to prepare a polishing pad. FIG. 13 is an SEM image of a cross section of the polishing pad according to Example 1, and FIG. 14 is an SEM image of the surface of the polishing pad.

  As shown in FIG. 13, the base material B and the polishing layer P were observed in the cross section of the polishing pad. A part of the resin mixed solution contained in the abrasive-containing solution was impregnated into the base material B, and as shown in the figure, a synthetic resin derived from the abrasive-containing solution was observed in the base material B. As shown in FIGS. 13 and 14, the abrasive grains are included in the polishing layer P and exist on the surface of the polishing pad. On the other hand, the abrasive grains are hardly present inside the base material B.

(Example 2)
A substrate having the structure described in the second embodiment was used. That is, a substrate obtained by laminating a polyethylene terephthalate nonwoven fabric on a resin sheet made of polyethylene terephthalate resin was used. A polishing pad was prepared by applying an abrasive-containing solution to the nonwoven fabric side surface of the substrate. FIG. 15 is an SEM image of a cross section of the polishing pad according to Example 2, and FIG. 16 is an SEM image of the surface of the polishing pad.

  As shown in FIG. 15, in the cross section of the polishing pad, the base material B composed of the resin sheet B1 and the nonwoven fabric B2 and the polishing layer P were observed. A part of the resin mixed solution contained in the abrasive-containing solution was impregnated into the nonwoven fabric B2, and as shown in the figure, a synthetic resin derived from the abrasive-containing solution was observed in the nonwoven fabric B2. As shown in FIGS. 15 and 16, the abrasive grains are included in the polishing layer P and exist on the surface of the polishing pad. On the other hand, the abrasive grains are hardly present inside the base material B.

(Comparative Example 1)
Using a resin sheet made of polyethylene terephthalate resin as a base material, an abrasive-containing solution was applied to the surface of the base material to prepare a polishing pad. FIG. 17 is an SEM image of the cross section of the polishing pad according to Comparative Example 1, and FIG. 18 is an SEM image of the surface of the polishing pad.

  As shown in FIG. 17, the base material B and the resin layer T were observed in the cross section of the polishing pad. The resin mixed solution contained in the abrasive grain-containing solution is not impregnated into the base material B, and forms a resin layer T. The abrasive grains are buried in the resin layer T and hardly exist on the surface of the resin layer T as shown in FIGS. 17 and 18.

(Comparative Example 2)
A surface of a polyester nonwoven fabric was treated with a primer, and a polishing pad was prepared by applying an abrasive-containing solution to the surface of the substrate. 19 is an SEM image of a cross section of the polishing pad according to Comparative Example 2, and FIG. 20 is an SEM image of the surface of the polishing pad.

  As shown in FIG. 19, the base material B and the resin layer T were observed in the cross section of the polishing pad. The resin mixed solution contained in the abrasive grain-containing solution is not impregnated into the base material B, and forms a resin layer T. The abrasive grains are buried in the resin layer T and hardly exist on the surface of the resin layer T as shown in FIGS.

  As described above, in Examples 1 and 2, the base material was impregnated with the resin mixed solution to obtain a polishing pad having abrasive grains on the surface. For this reason, high polishing characteristics can be obtained. On the other hand, the abrasive grains are not present in the base material, and the abrasive grains contained in the resin mixed solution are prevented from being wasted.

  On the other hand, in Comparative Examples 1 and 2, the abrasive grains are not present in the substrate, but are buried in the resin layer formed by the resin mixed solution. For this reason, these polishing pads do not have polishing characteristics due to abrasive grains and do not function as polishing pads.

DESCRIPTION OF SYMBOLS 10, 20 ... Polishing pad 11, 21 ... Base material 12, 22 ... Polishing layer 111 ... Synthetic resin 112, 212 ... Nonwoven fabric 121, 221 ... Curable resin 122, 222 ... Abrasive grain 211 ... Resin sheet

Claims (9)

A base material made of a material having voids;
A polishing pad comprising: a polishing layer formed by applying an abrasive-containing solution containing a curable resin and abrasive grains to the substrate and curing the curable resin. The polishing pad according to claim 1 or 2,
The gap of the base material is provided with a size that allows the curable resin before curing to pass therethrough and prevents the abrasive grains from passing therethrough. The polishing pad according to claim 1 or 2,
The substrate is a non-woven fabric impregnated with a synthetic resin. The polishing pad according to claim 3,
The base material is a nonwoven fabric made of polyester fibers impregnated with polyurethane resin. The polishing pad according to claim 1 or 2,
The said base material has the resin sheet which consists of synthetic resins, and the nonwoven fabric laminated | stacked on the said resin sheet, The said abrasive grain containing solution is apply | coated to the said nonwoven fabric. Polishing pad. The polishing pad according to claim 5, wherein
The resin sheet is made of polyethylene terephthalate resin,
The said nonwoven fabric is a nonwoven fabric which consists of a polyethylene terephthalate fiber Polishing pad. The polishing pad according to claim 1,
The curable resin includes a phenolic resin and an epoxy resin. The polishing pad according to claim 1,
The abrasive-containing solution further includes a solvent. Prepare an abrasive-containing solution containing a curable resin and abrasive grains,
Applying the abrasive-containing solution to a substrate made of a material having voids,
A method for producing a polishing pad, wherein a curable resin contained in the abrasive-containing solution is cured.