JP6465335B2 - Polishing tool - Google Patents

Description

  The present invention relates to a polishing tool for polishing a workpiece with high accuracy by relatively moving the workpiece while supplying a slurry containing an abrasive between the workpiece and the workpiece.

  Conventionally, the surface and end face of a workpiece such as a lens, a silicon wafer for a semiconductor device, a glass substrate for a liquid crystal display, a glass substrate for a hard disk, an aluminum substrate, etc. are required to have extremely high smoothness and flatness. A polishing tool is used to polish the workpiece with high precision by relatively moving the workpiece while supplying the slurry containing the abrasive during this period. Improvement in production efficiency by shortening the polishing time is required, and polishing tools and metal surface plates having a porous polishing surface made of a polymer material at least on the surface are widely used.

  As a polishing tool used for polishing the surface and end face of the workpiece, for example, a porous polishing pad made of urethane resin, epoxy resin, epoxy resin and urethane resin, or fiber entanglement A non-woven fabric type polishing pad, a urethane or epoxy-impregnated non-woven fabric type polishing pad impregnated with a polyurethane resin or an epoxy resin and cured with a non-woven fiber substrate (for example, see Patent Document 1), and fibers A urethane resin or epoxy resin solution is applied onto a substrate made of non-woven fabric or film, and this is solidified to form a porous silver surface layer having many bubbles, and the surface of the silver surface layer is ground. Suede-type polishing pad with a nap layer that is a porous polishing layer (see, for example, Patent Document 2), A cast iron surface plate or the like has been used so far for rough polishing. For example, the polishing pad is pasted on a rotatable polishing surface plate, and an object to be polished supported by a polishing head is attached to the polishing pad. While being pressed, polishing is performed by relatively rotating the polishing surface plate and the polishing head while supplying a polishing slurry in which abrasive grains, which are abrasives, are dispersed on the polishing pad.

  By the way, it is formed with a urethane resin on a non-woven fabric type polishing pad obtained by impregnating a polyurethane resin into a non-woven fiber substrate shown in Patent Document 1 and cured, or on a fiber substrate shown in Patent Document 2. When polishing the surface of an optical glass such as a lens or a glass substrate for a liquid crystal display as an object to be polished using the conventional polishing pad including a suede type polishing pad provided with a nap layer, the polishing efficiency is increased. For this reason, cerium oxide is mainly used as an abrasive, but rare earths (rare metals) such as cerium are highly dependent on a specific country of origin, and therefore are required to reduce the amount used.

  Therefore, the present inventors have invented a porous polishing pad previously formed of an epoxy resin, a polishing pad coated with an epoxy resin on a base material, and the like (for example, Patent Document 3 and Patent Document 4). These polishing pads can improve the polishing efficiency by increasing the holding power to the abrasive (abrasive grains).

Japanese Patent Laid-Open No. 10-249737 JP 2010-149259 A JP 2012-101298 A JP2012-121115A

  However, in the field of such a polishing pad, in order to shorten the polishing time and increase the production efficiency, further improvement of polishing characteristics is required.

  In addition, in conventional porous epoxy resin polishing pads, it became possible to improve the slurry holding power and improve the polishing characteristics, but the glass transition point in the base material cured and molded using a conventional amine curing agent Is present in the vicinity of room temperature, the mechanical properties change during polishing, which may cause a reduction in polishing characteristics.

  Therefore, the present invention increases the holding power of the slurry on the polishing surface on the conventional porous polishing pad and metal surface plate, and increases the abrasive (abrasive grains) contributing to polishing by acting effectively. It is another object of the present invention to provide a polishing tool having even more excellent polishing characteristics by reducing the change in mechanical properties of the substrate near normal temperature.

The polishing tool according to the present invention made to solve the above problems is an epoxy resin or a mixed resin of an epoxy resin and a urethane resin, a porous base material or a metal base material made of an epoxy resin or an epoxy resin and a urethane resin. A polyamide-based curing agent is used as a curing agent that has a substrate coated or impregnated / cured with a mixed resin, and is in a liquid state before being cured and is cured and molded.

The present invention effectively retains the slurry on the porous polishing pad and the metal surface plate by using a polyamide-based curing agent instead of the conventional amine-based curing agent at the time of curing molding of an epoxy resin or the like used for the base material. Increases the amount of abrasives (abrasive grains) that contribute to polishing by allowing them to act on the surface, and reduces changes in mechanical properties near normal temperature in substrates that have been cured using conventional amine curing agents This makes it possible to improve the polishing characteristics.

In the present invention, the D hardness after curing of the epoxy resin or the mixed resin of the epoxy resin and the urethane resin as the base material of the polishing tool is in the range of 15 to 65 (Claim 2 ), and the epoxy resin or epoxy as the base material A mixed resin of resin and urethane resin, made of metal such as stainless steel, titanium, and aluminum, or short fibers made of resin such as polyester, nylon, and polyimide, or a metal or resin fiber woven in a mesh shape, or The present invention is also effective in a polishing tool containing a metal or resin long-fiber non-woven fabric (claim 3 ). Moreover, the porosity of the base material of the polishing tool is 5 to 70%, the formed pore diameter is 5 to 500 μm (claim 4 ), and lattice-like grooves are formed on the surface of the base material of the polishing tool. Being formed (Claim 5 ) also gives favorable results.

  The polishing tool according to the present invention uses an amide-based curing agent with high affinity capable of curing and molding a resin having a hydrophilic group in curing molding of an epoxy resin used as a base material and a mixed resin of an epoxy resin and a urethane resin. The affinity between the substrate and the aqueous slurry is increased, the slurry holding on the polishing pad is effectively acted, and the polishing agent (abrasive grains) contributing to polishing is increased, so that the polishing characteristics are greatly improved.

In addition, by curing and molding a resin having a hydrophilic group using an amide-based curing agent that can be cured and molded, an epoxy resin and a mixed resin of an epoxy resin and a urethane resin that are used in conventional polishing pads are used at room temperature. Since the glass transition point in the vicinity rises to 40 ° C. or higher, the change in mechanical properties near normal temperature is reduced.

1 is a perspective view (porous polishing pad) showing an embodiment of a polishing tool according to the present invention. Part of the component structural formula in the preferred curing agent used in the polishing tool according to the invention. The comparison figure of the dynamic viscoelasticity of the polishing pad about embodiment in the polishing tool by this invention. The photograph which shows the external appearance of the Example in this invention using the polishing pad as a polishing tool. The surface optical micrograph of the polishing pad in the Example shown in FIG. The comparison figure which showed the contact angle of the polishing pad in the Example shown in FIG. 4 with the comparative example. FIG. 5 is a relationship diagram between the rotation speed of the polishing pad and the polishing efficiency in the embodiment shown in FIG. 4. FIG. 5 is a diagram showing the relationship between the abrasive grain concentration of the polishing pad and the polishing efficiency in the embodiment shown in FIG. 4. FIG. 5 is a relationship diagram between the number of rotations of the workpiece and the surface plate of the polishing pad and the polishing characteristics in the embodiment shown in FIG. 4. The expanded sectional schematic of the Example in this invention which used the suede pad as a grinding | polishing tool. The expanded sectional schematic diagram in the Example of this invention using the lapping tool as a grinding | polishing tool. The expanded cross-sectional schematic which shows the Example of this invention using the metal fiber containing lapping tool as a grinding | polishing tool. FIG. 13 is a confocal micrograph of the polishing pad surface in the example shown in FIG. 12.

  Next, an embodiment using a porous epoxy resin polishing pad as an example of the polishing tool of the present invention will be described with reference to the drawings.

  FIG. 1 shows a preferred embodiment of the polishing pad of the present invention used by being attached to a rotary polishing table. Reference numeral 1 denotes an amide-based curing which is a curing agent capable of curing and molding a resin having a hydrophilic group. It is a porous epoxy resin polishing pad cured with an agent, and a large number of pores 3 having a diameter of 0.001 to 3 mm are formed in a thin cylindrical porous substrate 2.

  More specifically, in the present embodiment, for example, an amide-based curing agent having a structure as shown in FIG. 2 is added to a mixture of a thermosetting epoxy resin as a base material and a foaming agent, and foamed in a mold. After being cured, it is released from the mold and secondarily dried at room temperature. Then, it slices into predetermined thickness and makes it a thin sheet-like product. The method for producing the porous epoxy resin polishing pad is not limited to this, and various conventionally known methods can be used.

  Affinity with the polishing slurry is achieved by curing and molding the epoxy resin or the mixed resin of epoxy resin and urethane resin, which is the base material of the porous epoxy resin polishing pad, using an amide curing agent that can cure and mold a resin having a hydrophilic group. It is possible to improve the property, improve the retention of the abrasive grains, and improve the retention of the abrasive. As a result, when performing polishing using the porous epoxy resin polishing pad, the abrasive grains held on the polishing pad move while being dragged by the object to be polished along with the relative rotation with the object to be polished. And the removal of the polishing slurry by the centrifugal force accompanying the rotation of the polishing pad can be suppressed, so that the polishing efficiency can be improved.

In addition, in the case of a porous epoxy resin polishing pad made by curing and molding a base material using an epoxy resin or a mixed resin of an epoxy resin and a urethane resin using an amide curing agent, the substrate is cured using an existing amine curing agent. Compared with a porous epoxy resin polishing pad, the glass transition point is increased, so that stable polishing can be performed. As can be seen from the comparison diagram of dynamic viscoelasticity shown in FIG. 3, when a glass transition point exists near room temperature, the mechanical property value of the polishing pad greatly changes during polishing, and the polishing pad and the coated surface are covered. This is because the adhesiveness to the workpiece becomes unstable, which may hinder stable polishing.

Porous polishing pad: 100.0 g of bisphenol A type epoxy resin (epoxy equivalent 230 to 270) preheated at 100 ° C. to reduce the viscosity, epoxy resin curing agent containing amino group (polyoxypropylenediamine active hydrogen equivalent) 514) 69.0 g and 24.5 g of an epoxy resin curing agent (polyaminoamide amine value 535) containing an amide group and an amino group were added. Further, in order to form pores in the polishing pad, a foaming agent (Cellular D manufactured by Eiwa Kasei) and a foaming assistant (Cell Base M3 manufactured by Eiwa Kasei) were added.
The same amount of foaming agent and foaming aid was added, and the addition amount was changed in the range of 2.5 to 4.1 g. After mixing these materials, the mixture was stirred and poured into a mold. Then, it heated and hardened and foamed with resin. It was kept at a heating temperature of 150 ° C. for 3 hours.

  FIG. 4 shows an external view of the manufactured polishing pad. FIG. 5 is an optical micrograph of the surface of the polishing pad, and it can be confirmed that a large number of pores are formed on the surface of the polishing pad by adding a foaming agent.

  FIG. 6 shows a porous epoxy resin polishing pad according to the present invention prepared according to Example 1, a commercially available general porous urethane resin polishing pad, and a porous epoxy resin polishing cured with a conventional amine curing agent. The comparison figure of the slurry contact angle which dripped 70 microliters of liquid slurry on the pad and measured the contact angle is shown. The contact angle of the product of the present invention shown in the above examples is 95.9 °, the contact angle of a commercially available general porous urethane resin polishing pad is 109.5 °, and the conventional porous epoxy resin polishing pad is 98 .8 ° was shown. Since the lower the contact angle, the higher the affinity with the slurry, it can be confirmed that the polishing pad of the present example has higher affinity with the slurry than other conventional examples.

Next, glass polishing experiments were performed using the polishing pad of Example 1 and cerium oxide abrasive grains. Table 1 shows the polishing experimental conditions.

  Since each of the produced polishing pads had irregularities on the surface, cutting (facing) was performed on the polishing machine. Soda glass was used for the workpiece, the polishing pressure was 20 kPa, and the rotation speed of the polishing pad and the workpiece was 90 rpm. Further, cerium oxide having an average particle diameter of 1.2 μm (SHOROX A-10 manufactured by Showa Denko) was used as the abrasive grains and dispersed in pure water. For comparison, a commercially available porous urethane resin polishing pad (NFP-05 without abrasive grains manufactured by Kuju Electric) and a conventional porous epoxy resin polishing pad (EPO 05 without abrasive grains manufactured by Kuju Electric) were used. A polishing test was conducted under the same conditions. The surface roughness after polishing was evaluated by a white interference microscope (ZYGO New View 7300), and the polishing efficiency was evaluated by the mass difference between the workpieces before and after polishing.

  FIG. 7 shows a general porous urethane resin polishing pad, a porous epoxy resin polishing pad formed by curing with a conventional amine curing agent, and a porous material using an amide curing agent of Example 1 of the present invention for curing molding. The relationship between the polishing efficiency of the high-quality epoxy resin polishing pad and the roughness of the finished surface of the workpiece after processing (surface roughness) is shown. In Example 1 of the present invention, a polishing efficiency about 4 times that of a general porous urethane resin polishing pad was obtained, and about 1.6 times that of a conventional porous epoxy resin polishing pad. The polishing efficiency was obtained. It can be confirmed that the finished surface roughness (surface roughness) of the workpiece after processing is improved by about 1.5 times compared to a general porous urethane resin polishing pad, and a conventional porous epoxy resin polishing pad. It was confirmed that the same finished surface roughness (surface roughness) can be obtained even when compared with. From these facts, it is confirmed that the finished surface roughness (surface roughness) is improved while having a high polishing efficiency when compared to a conventional commercially available general porous urethane resin polishing pad. Even when compared with a high-quality epoxy resin polishing pad, it was confirmed that the polishing efficiency was improved while having the same finished surface roughness (surface roughness).

  FIG. 8 shows a general porous urethane resin polishing pad, a porous epoxy resin polishing pad formed by curing with a conventional amine curing agent, and a porous material using an amide curing agent according to an embodiment of the present invention for curing molding. This shows the relationship between the abrasive concentration of the epoxy resin polishing pad and the polishing efficiency, and the abrasive concentration was changed to 0.1, 0.5, 1, 3, and 5 wt%, respectively, and the polishing test was performed. In a general porous urethane resin polishing pad and a porous epoxy resin polishing pad formed by curing with a conventional amine curing agent, the polishing efficiency decreases as the abrasive concentration decreases. It can be seen that the concentration is saturated at 0.5 wt%. This is a result of high polishing efficiency even at a low abrasive concentration because the holding power of the abrasive grains was improved.

  FIG. 9 shows a porous epoxy resin polishing pad formed by curing with a general porous urethane resin polishing pad and a conventional amine curing agent, and a porous material using the amide curing agent of Example 1 of the present invention for curing molding. The relationship between the number of revolutions of the quality epoxy resin polishing pad and the polishing characteristics is shown. The polishing test was carried out by changing the workpiece and the surface plate rotation speed to 60, 90 and 120 rpm, respectively. It can be seen that the conventional porous epoxy resin polishing pad and the polishing pad of the present invention have higher polishing efficiency than general porous urethane resin polishing pads at any number of rotations. Also, in comparison between the conventional porous epoxy resin polishing pad and the polishing pad of the present invention, the polishing pad of the present invention showed high polishing efficiency at any number of rotations. The centrifugal force acting increases as the rotational speed increases, and the retention of the abrasive grains decreases because the slurry is swept out of the polishing region, but the polishing pad of the present invention has improved retention of abrasive grains, This is a result that high polishing efficiency was obtained by the retention of the abrasive grains in any rotation region.

This is because a porous epoxy resin polishing pad produced by curing and forming an amide-based curing agent on a substrate according to the present invention is a porous urethane resin polishing pad using a urethane resin as a conventionally marketed substrate and Compared to conventional porous epoxy resin polishing pads using epoxy resin cured with amine curing agent on the base material, the affinity of the epoxy resin as the base material has been increased, so the slurry retention on the polishing pad is effective This is a result of increasing the polishing characteristics greatly by increasing the abrasive (abrasive grains) contributing to polishing.

  In addition, the epoxy resin cured with the amide curing agent according to the present invention and the mixed resin of the epoxy resin and the urethane resin are applied to a nonwoven fabric pad and a suede pad or impregnated / cured, and the resin according to the present invention Apply or impregnating / curing a wrapping tool using a metal or resin mesh coated or impregnated, a metal or resin short fiber or fiber woven into a mesh, or a resin containing a non-woven fabric of long fibers It is also possible to use for the resin part etc. in the made lapping tool, and the effect similar to the present Example 1 is expectable.

Suede pad An epoxy resin and a mixed resin of an epoxy resin and a urethane resin which are cured and molded using the amide-based curing agent according to the present invention are arranged in the thickness direction on the substrate 4 and the substrate 4 as shown in FIG. A resin layer is formed by applying or impregnating and curing the nap layer 6 of a so-called suede type polishing pad provided with a nap layer 6 in which a large number of elongated vertical holes (nap) 5 are formed.

  The substrate 4 is made of, for example, a nonwoven fabric composed of fibers, a urethane-impregnated nonwoven fabric obtained by impregnating the nonwoven fabric with a urethane resin, or a resin film. The nap layer 6 is obtained by applying a urethane resin solution in which a urethane resin is dissolved in a water-soluble organic solvent such as dimethylformamide on the base material 4, treating this in water, and wet coagulating it to form a porous silver surface layer. It is formed by grinding the surface of the silver layer after washing with water and drying.

  In the polishing pad 7, the nap layer 6 is sprayed with a dispersion liquid in which a mixed resin of an epoxy resin and an epoxy resin and a urethane resin cured by using the amide curing agent of the present invention is dispersed in a solvent. The resin film 8 of the resin of the present invention is formed on the surface of the nap layer 6 and in the vertical holes 5 by coating using a conventionally known coating method such as coating or spin coater coating. Thereby, in addition to the structural grip force by the vertical hole 5, the polishing agent can be held by the holding force obtained by the resin film, so that the polishing characteristics can be improved.

A lapping tool An epoxy resin and a mixed resin of an epoxy resin and a urethane resin cured and molded using the amide-based curing agent of the present invention are applied or impregnated and cured on a surface plate 9 as shown in FIG. 8 is formed.

  The surface plate 9 is formed of SUS, cast iron, or the like, and is grooved as necessary. For this surface plate surface, a dispersion liquid in which a mixed resin of an epoxy resin and an epoxy resin and a urethane resin cured with an amide curing agent according to the present invention is dispersed in a solvent, such as spray coating or spin coater coating By applying using a conventionally known coating method, the resin film 8 of the resin of the present invention is formed. Since the abrasive can be held by the holding force obtained by the formed resin film, the polishing characteristics can be improved.

Short metal fiber-containing lapping tool After mixing bisphenol A type epoxy resin, which is the main agent, short metal fiber having a diameter of 50 μm and a length of 2500 μm, and an amide-based curing agent, the mixture was stirred and cast into a mold for curing. FIG. 12 is an enlarged schematic cross-sectional view of the produced lapping tool, and FIG. 13 is a confocal micrograph of the surface.

  In this Example 4, the base material 4 is formed by casting an epoxy resin and a mixed resin of an epoxy resin and a urethane resin, which are cured and molded using an amide-based curing agent in which the short metal fibers 10 are blended, into a mold, The base material 4 is attached to a surface plate 9, and the surface plate 9 and a workpiece (not shown) are relatively moved to polish the workpiece. Since the abrasive can be held by the holding force provided by the formed base material 4 more than the conventional one, the polishing characteristics can be improved.

DESCRIPTION OF SYMBOLS 1 Polishing pad (base material), 2 Porous body, 3 Pore 4 Base material, 5 Vertical hole (nap), 6 Nap layer 7 Polishing pad, 8 Resin film, 9 Surface plate 10 Metal short fiber

Claims (5)

A base material made of a porous epoxy resin, a base material made of a mixed resin of a porous epoxy resin and a urethane resin, a porous base material or a metal base material with an epoxy resin or a mixed resin of an epoxy resin and a urethane resin A polishing tool for polishing a workpiece by moving the workpiece relative to a coated or impregnated / cured substrate while supplying a slurry containing an abrasive to the workpiece, A polishing tool, wherein a resin constituting each substrate is a thermosetting resin that is in a liquid state before being cured and is cured and molded using a polyamide-based curing agent.   2. The polishing tool according to claim 1, wherein the D hardness after curing of an epoxy resin or a mixed resin of an epoxy resin and a urethane resin used for the base material of the polishing tool is 15 to 65. 3.   The polishing tool according to claim 1 or 2, wherein a metal or resin fiber is contained in an epoxy resin or a mixed resin of an epoxy resin and a urethane resin used for the base material of the polishing tool.   The porosity of an epoxy resin or a mixed resin of an epoxy resin and a urethane resin used for the base material of the polishing tool is 5 to 70%, and the formed pore diameter is 5 to 500 µm. 2. The polishing tool according to 2 or 3.   The polishing tool according to claim 1, 2, 3, or 4, wherein a lattice-like groove is formed on a surface of a base material of the polishing tool.