JP5922322B2 - Manufacturing method of gap adjusting type polishing tool - Google Patents

Description

The present invention provides a lapping surface plate or polishing pad for polishing a workpiece with high precision (lap polishing) by relatively moving the workpiece while supplying a slurry containing an abrasive between the workpiece and the like. This invention relates to a method for manufacturing the gap adjusting type polishing tool.

  Conventionally, liquid crystal glass for displays, plate glass, optical lens prisms, and surfaces and end faces of workpieces such as semiconductor wafers require extremely high smoothness and flatness. High-precision polishing finish is required.

  Therefore, for example, a lapping plate that polishes the workpiece by relatively moving the workpiece while supplying a slurry containing an abrasive having a particle size of about 0.5 to 10 μm to the workpiece. A gap adjusting type polishing tool such as a polishing pad used in the next process is known.

  And means for improving the flatness of the processed surface by eliminating the difference between the polishing by the polishing slurry and the polishing rate by the polishing pad by setting the particle size of the abrasive contained in the polishing pad in the same range. It is presented in 2007-250166.

However, as described above, an abrasive having a particle size of about 0.5 to 2.0 μm is used to polish the surface of a work part that requires extremely high smoothness and flatness as described above. and the gap between the work unit also becomes about 0.5 to 2.0 [mu] m, although the polishing unevenness by abrasive particles of differences to be used is eliminated, homogeneous polishing surface without polishing slurries is spread over the entire surface of the polishing region and supplies In particular, such a situation occurs in polishing a large-sized workpiece (having a wide polishing surface).

  Further, as disclosed in, for example, Japanese Patent Application Laid-Open No. 2005-177945, a polishing pad is proposed in which a certain groove is formed on the surface of the polishing region of the polishing pad so that the polishing slurry can be spread over the entire surface.

  However, a gap adjusting type polishing tool such as a polishing pad having a groove or a lapping surface plate has a problem that the shape of the groove is transferred to a workpiece to cause undulation.

JP 2007-250166 A JP 2005-177945 A

The present invention, wherein has been made to solve the clearance adjustment type polishing tool is being problems have, such as a conventional polishing pad and the lap plate, extremely high flat Namerado and flatness are determined is also rather than to say that performing final polishing of high accuracy, polishing no difference in polishing characteristics at the central portion and the peripheral portion even in a large workpiece manufacturing method of the row e Ru clearance adjustment type grinding tool The issue is to provide.

The present invention has been made to solve the above problems, the base while supplying a slurry containing abrasive material having a particle size diameter 0.5~10μm between the workpiece and the base material to form a polishing pad method for manufacturing a gap-adjusting polishing tool you polish the workpiece by abrasive flowing between wood and the workpiece and the relatively moving Rutotomoni workpiece to the substrate under pressure and the workpiece With a diameter of 0 . 05 to 0.5 softer than the material of the workpiece with a grain size of mm, the base harder formed substrate surface cutting treatment to the substrate surface is a polished surface contain a hard particles than material The slurry containing the abrasive is smoothly supplied to the entire surface of the workpiece through a gap formed between the workpiece and the substrate surface by the hard particles protruding to the workpiece. It is characterized in that the entire surface is a uniform finished surface.

  Further, in the present invention, the hard particles to be blended are softer than the material to be processed and harder than the polishing pad and the lapping plate, for example, various thermoplastic polymers such as glass beads, polystyrene, titanium oxide, EVA, PP, and PET. -, Apatite particles, porous silica, and other abrasive grains are preferable, and the blending amount of the hard particles is preferably 1 to 20% by volume.

  According to the present invention, it is possible to ensure a gap with the workpiece, improve the fluidity of the polishing slurry, and generate uniform polishing characteristics without generating undulations.

The perspective view which shows preferable embodiment of this invention. The enlarged photograph by the microscope about the surface of the Example (GB-A) of this invention. The enlarged photograph by the microscope about the surface of the Example (GB-B) of this invention. The enlarged photograph by the microscope about the surface of the Example (GB-C) of this invention. The enlarged photograph by the microscope about the surface of a comparative example (KSP-66A). The enlarged photograph by the microscope about the surface of a comparative example (FQ). The relationship figure of the particle size of a glass bead and a clearance gap shape about an Example and a comparative example. The surface view about the comparative example which put the groove | channel on the surface. The relationship figure of the particle size of the glass bead and the finishing surface of a workpiece about an Example and a comparative example. Explanatory drawing which shows the flow of the slurry at the time of grinding | polishing in the Example of this invention. The relationship figure of the particle size of the glass bead and the surface waviness of a workpiece about an Example and a comparative example.

  Next, the best mode of the present invention will be described with reference to the drawings.

  FIG. 1 shows a preferred embodiment of a gap adjusting type polishing tool 1 which is a polishing pad attached to a rotary polishing table. The gap adjusting type polishing tool 1 is a thin cylindrical column-shaped polishing pad substrate. 2 is mixed with, for example, 1 to 20% by volume of hard particles 3 having a diameter of about 0.05 to 0.5 mm.

  More specifically, in the present embodiment, for example, 1 to 20% by volume of abrasive grains made of glass beads having a diameter of about 0.05 to 0.5 mm are added to a mixture of a urethane resin as a base material and a foaming agent. It mix | blends in a ratio, a hardening | curing agent is added as a uniform mixture, it is made to foam in a metal mold | die, mold release, and secondary drying at room temperature manufactures.

  150 g of urethane resin pre-heated at 120 ° C. and reduced in viscosity (Mitsui Chemicals Polyurethane Co., Ltd., High Plain U-51), 5 g of foaming agent (Yewa Kasei Chemical Co., Ltd., endothermic decomposition type cellbon SC-K) And glass beads (manufactured by Sansho Abrasive Co., Ltd., GB-A: particle size 106-150 μm, GB-B: particle size 250-425 μm, GB-C: particle size 425-600 μm) It mixed and stirred using the mechanical stirrer (the Keyence Corporation make, hybrid mixer HM-500), and the uniform mixture was created.

  Next, 20 g of a curing agent (Seika Industry Co., Ltd., bisamine A) preheated at 120 ° C. to reduce the viscosity is mixed into the mixture and stirred for 30 seconds, and then a fluororesin sheet is preliminarily used as a release agent. Pour into the attached cylindrical mold, defoam with a vacuum defoamer (manufactured by Yasui Intertec Co., Ltd.), hold at 170 ° C. for 25 minutes, and first cure, then release from mold Then, secondary curing was carried out by leaving it to stand at room temperature for about a day.

  About the surface of the gap adjusting type polishing tool (GB-A (particle size: 106 to 150 μm), GB-B (particle size: 250 to 425 μm), GB-C (particle size: 425 to 600 μm))) which is the obtained polishing pad Enlarged photographs are shown in FIGS.

  Next, after facing the surfaces of the gap adjusting type polishing tools GB-A, GB-B, and GB-C, the shape of the pad surface is measured using a surface roughness measuring instrument (SURFTEST SV-600 manufactured by Mitutoyo Corporation). A high-pass filter was applied, and the roughness curve was compared with a polishing pad (KSP-66A) containing ceria (KSP-66A, manufactured by Kuju Electric Co., Ltd.) as a comparative example. The measurement was performed together with a polishing pad (FQ) mixed with 5 μm silica particles (FQ3000, manufactured by Fujimi Incorporated).

  As a result, the maximum height Ry (mm) increases as the particle size of the glass beads contained in the polishing pad increases from the relationship between the particle size of the glass beads and the gap shape shown in FIG. It has been confirmed that the average interval between the irregularities tends to be small, and the size of the particle size of the glass beads to be contained and the gap size of the gap adjusting type polishing tool have a high correlation.

  Next, for each of the obtained gap adjusting type polishing tools GB-A, GB-B, and GB-C, a workpiece 4 (soda glass having a diameter of 20 mm and a thickness of 10 mm is wrapped to prepare a pear ground pre-process. Roughness Ra = approx. 35 mm, processed surface roughness 0.2 μm) is attached to the surface plate of a tabletop precision lapping machine (manufactured by Nano Factor Co., Ltd.), polishing pressure 20 kPa, tool rotation speed 60 rpm, Workpiece rotation speed 60rpm, machining time 30min. Slurry supply rate 25 mL / min. Polishing was carried out by forcibly rotating driving under polishing conditions of abrasive grains (Cerium oxide Showa Denko Corporation SHOROX A-10 average particle size 1.2 μm, abrasive grain addition rate 3.0 wt%).

  As a result, the measurement result of the roughness of the polishing surface is shown on the surface of the FQ3000 (a polishing pad (FQ) containing silica particles having a particle size of 3.5 μm instead of glass beads) and the polishing pad of this FQ3000. FIG. 9 shows a gap adjusting type polishing tool (FQ grooved) which is a polishing pad having lattice-shaped grooves of the shape shown in FIG. 9 as a comparative example.

  The finished surface is measured using a white light interference type non-contact type three-dimensional surface shape / roughness measuring device (Zygo Corporation, Zygo New View 5032). The arithmetic average height was obtained from the cross-sectional curve of the surface at.

  From FIG. 9, it was confirmed that the roughness of the finished surface was improved when a gap adjusting type polishing tool which is a grooved polishing pad as a comparative example was used, and a relatively large glass bead was included. In the case of the gap adjusting type polishing tool which is a polishing pad, it has been confirmed that the effect of improving the surface roughness equal to or higher than that of the grooved gap adjusting type polishing tool is obtained. In particular, the gap adjusting type polishing tool GB- In the case of B (applying glass beads having a particle size of 250 to 425 μm), the center 4, the peripheral part, and the intermediate part of the workpiece 4 were hardly observed, and a very high polishing special product was obtained.

  This is smoothly supplied to the center of the workpiece with a large abrasive slurry diameter through the gap with the workpiece by the glass beads formed on the gap-adjusting type polishing tool, and a uniform finished surface is obtained on the entire surface of the workpiece. This is the result obtained (see FIG. 10).

  Next, as a comparative example, the measurement result of “swell” on the surface of the workpiece 4 when polished under the above conditions is used as a comparative example. Polishing pad FQ (polishing containing silica particles having a particle size of 3.5 μm instead of glass beads) FIG. 11 shows the pad and the FQ grooved polishing pad in which lattice-like grooves having the shape shown in FIG. 8 are formed on the surface of the polishing pad FQ.

  From FIG. 11, the polishing pad FQ as a comparative example shows a large swell at the center of the workpiece, and when the polishing pad FQ is provided, the swell at the center is reduced but the overall swell is not eliminated. Although it is confirmed, it is confirmed that the overall waviness is eliminated for the gap adjusting type polishing tools GB-A and GB-B (containing glass beads having a particle size of 106 to 425 μm) which are examples of the present invention. Is done.

  From these facts, it was confirmed that the gap-adjusting type polishing tool, which is the polishing pad of the present invention, is more effective in terms of swell than the grooved polishing pad that has been said to be effective conventionally.

In addition, although the said Example showed the case where a polishing pad was used as a clearance adjustment type | mold polishing tool, this invention is effective on the same principle also when a lapping surface plate is used as a clearance adjustment type polishing tool, and this implementation is carried out. in the example a gap adjustment type grinding tool Ru lap plate Dare similar glass beads used in the polishing pad and cast iron particles having a diameter of 0.4 to 0.8 mm - were prepared by sintering's.

Production conditions: Molding pressure 500 MPa, 1100 ° C., 1 hour in argon gas Specific gravity after sintering is about 6 g / cm ³ and porosity is 10%.
In this embodiment, the lapping platen is manufactured by a sintering method, but can also be manufactured by a casting method.

  1 polishing pad, 2 urethane substrate, 3 abrasive grains

The present invention is supported by the New Energy and Industrial Technology Development Organization (NEDO Technology Development Organization).

Claims (3)

While supplying a slurry containing an abrasive having a particle diameter of 0.5 to 10 μm between the base material forming the polishing pad and the work piece, the base material and the work piece are relatively moved and the work piece is moved. A method for manufacturing a gap-adjusting type polishing tool for polishing a workpiece with an abrasive flowing between the base material and the workpiece by applying pressure to the workpiece, the particle diameter having a diameter of 0.05 to 0.5 mm The material of the workpiece is softer than the material of the workpiece, and hard particles formed harder than the base material are contained in the base material, and the surface of the base material, which is a polishing surface, is cut to protrude from the base material surface. By smoothly supplying the slurry containing the abrasive to the entire surface of the workpiece through a gap formed between the workpiece and the substrate surface by the hard particles, the slurry is caused to flow. It is characterized by a uniform finish on the entire surface of the object. Method for producing a clearance adjustment type grinding tool to. While supplying a slurry containing an abrasive having a particle diameter of 0.5 to 10 μm between the base material forming the lapping plate and the workpiece, the base material and the workpiece are relatively moved. A method for manufacturing a gap-adjusting type polishing tool in which a workpiece is polished by an abrasive that flows between the substrate and the workpiece by applying pressure to the workpiece, the particle having a diameter of 0.05 to 0.5 mm It is softer than the material of the workpiece in diameter, and hard particles formed harder than the base material are contained in the base material, and the base material surface that is a polishing surface is cut to protrude from the base material surface. The slurry containing the abrasive is smoothly supplied to the entire surface of the workpiece through a gap formed between the workpiece and the substrate surface by the hard particles, thereby causing the slurry to flow. A feature that makes the entire surface of the workpiece a uniform finish. Method for producing a clearance adjustment type grinding tool to. The method for producing a gap adjusting type polishing tool according to claim 1 or 2, wherein the amount of the hard particles is 1 to 20% by volume .