JP2005088157A - Band knife type slicer and manufacturing method of polishing pad - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a polishing pad, little varied in thickness and a good slice surface using a band knife type slicer in device and method of taking out a polishing layer from a polishing layer material provided as a hard resin block. <P>SOLUTION: The resin block is heated ranging from 60°C to 140°C and sliced while the band knife is polished using the band knife type slicer having a heat insulating and/or heating mechanism. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a band knife type slicer and a method of manufacturing a polishing pad using the same, and further mechanically planarizes the surface of an insulating layer formed on a semiconductor substrate such as silicon or the surface of a metal wiring. The present invention relates to chemical mechanical polishing in the process.

  Conventionally, a band knife type slicer, a longitudinal slicer, a planer, etc. are used as a method for cutting out a thin sheet-like material from a resin block.

  Mainly, the cutting board is rarely used for cutting out thin sheets, and is used for the purpose of adjusting the thickness of plate-like objects, and thin sheet-like chips are extremely curled by shear during slicing. It becomes. A longitudinal slicer is a device that moves and slices a blade or a table that conveys an object to be sliced. However, due to its structure, there are many unusable parts for a product called “left-over”. Further, in many cases, a cemented carbide blade is used as the blade, and re-polishing due to abrasion is necessary, and there is a problem of time loss and polishing cost associated with blade replacement. Thin sheet-like slices do not reach the level of a planer, but relatively strongly curl. On the other hand, the band knife type slicer (or the band knife type splitting machine type G (Germany, Fecken-Kirfel)) does not have these problems that occur in a planer or longitudinal slicer. However, when it is intended to be used for a slice (for example, a polishing layer for a polishing pad) that requires precise accuracy, the accuracy is not sufficient. The slice accuracy of the band knife type splitting machine type G is about ± 0.1 mm. Moreover, it is known that a hard resin block can be softened by heating. However, it is not known to grind the softened material with a band knife type slicer, longitudinal slicer, or planer, and in fact, it has a heat retention mechanism or a heating mechanism for softening a hard resin block These devices are not known.

  An object of the present invention is to provide a method of slicing and removing a polishing layer having a good slice surface with little thickness variation from a polishing layer material provided as a hard resin block, using a band knife type slicer. .

As means for solving the above problems, the present invention has the following configuration.
(A) a band-knife slicer having means for keeping and / or heating the slices;
(B) A method for producing a polishing pad comprising a step of slicing a polishing layer from a resin block containing polyurethane using the band knife slicer according to (a),
(C) The method for producing a polishing pad according to (b), wherein the resin block is preheated to 60 ° C. or higher and 140 ° C. or lower and sliced.
(D) The band knife type slicer comprises means for polishing the blade, and the polishing pad manufacturing method according to (b) or (c), wherein the resin block is sliced while polishing the blade,
(E) The method for producing a polishing pad according to any one of (b) to (d), wherein the resin block includes a polymer polymerized from polyurethane and a vinyl compound.
(F) The method for producing a polishing pad according to (e), wherein the vinyl compound is obtained using a compound having a structure represented by the following general formula (1):
General formula (1)
CH ₂ = CR ¹ COOR ²
(Here, R ¹ is a methyl group or an ethyl group, and R ² is a methyl group, an ethyl group, a propyl group, or a butyl group.)
(G) The polishing pad is used for CMP and is composed of a single polishing layer or a polishing pad in which a polishing layer and other layers are laminated. A method for producing a polishing pad according to any one of the above.

  According to the present invention, it is possible to provide a more effective band knife type slicer and polishing pad manufacturing method for obtaining a polishing layer having a small slice surface with less variation in the thickness of the polishing layer in slicing the resin block.

  The present invention will be specifically described below.

  First, the heat retaining and / or heating means provided in the band-type slicer of the present invention is a device installed at the inlet of the slicer, and the required characteristics are 100 mm in length and 100 mm in width heated to 100 ° C. at room temperature. If the temperature of the bottom surface of the resin block after leaving the resin block as a sliced object with a thickness of 15 mm for 1 minute at the center of the heat retaining and / or heating mechanism of the apparatus for 1 minute is required, The structure and mechanism are not particularly limited. As a simple heating mechanism, a rubber heater, a halogen lamp, a ceramic heater, or the like can be adopted, but a rubber heater is preferable because of easy temperature control. The heating temperature is preferably 60 ° C. or higher and 140 ° C. or lower. If the temperature is lower than 60 ° C., the object to be sliced is not sufficiently softened, so that it is difficult to slice. When the temperature is higher than 140 ° C., the object to be sliced is denatured, or the temperature at the time of heating is transferred to the slicer device, and the accuracy of the slice thickness is reduced. A more preferable temperature range is 80 ° C. or higher and 120 ° C. or lower. More preferably, the object to be sliced is preheated to 80 ° C. or higher and 120 ° C. or lower before slicing.

  The blade of the band knife type slicer used in the present invention is preferably HS steel, but cheaper stainless steel can also be used, and the material is not limited as long as it can be an endless band knife. Absent. The blades are not polished during slicing because there is a possibility that knife scraps may be mixed in the product, but the slicer is equipped with a polishing means and can slice while polishing the blade during slicing. preferable.

  When the blade is not polished during slicing, the sharpness of the blade is different immediately after the start of slicing and just before the end of slicing, and the quality of the slice surface of the slice is deteriorated. The deterioration of the quality of the slice surface means that the thickness accuracy is lowered, or knife mark marks appear on the slice surface.

  As a means for polishing the blade, a conventionally known method can be adopted, but it is preferable to use a diamond grinder because a sharp blade edge can be obtained. The polishing waste of the band knife can be removed by installing a felt, a brush or a suction device immediately after the polishing mechanism.

  As the band knife type slicer used in the present invention, for example, those manufactured by Sakura Kikai Kogyo Co., Ltd. or Murota Manufacturing Co., Ltd. can be used, and this is used as a means for keeping and / or heating the object to be sliced.

  In the present invention, the polishing layer of the polishing pad is sliced from the resin block.

  The resin block used in the present invention has elasticity in the thickness direction in the sliced polishing layer that has closed cells, and slurry aggregates and polishing debris are sandwiched between the surface to be polished and the polishing pad. However, it is necessary because the generation of scratches can be prevented. The closed cell diameter is preferably 1000 μm or less in terms of average cell diameter because the flatness of local irregularities of the material to be polished is good. The more preferable average bubble diameter of the closed cell diameter is 500 μm or less, and the more preferable average bubble diameter is 300 μm or less.

The resin block used in the present invention preferably has a density in the range of 0.4 to 1.1 (g / cm ³ ). When the density of the polishing layer sliced from the resin block is less than 0.4 (g / cm ³ ), it is not preferable because the flatness of local unevenness becomes poor and the global step becomes large. When the density exceeds 1.1 (g / cm ³ ), scratches are likely to occur, which is not preferable. A more preferable density is in the range of 0.6 to 0.9 (g / cm ³ ). A more preferable density is in the range of 0.65 to 0.85 (g / cm ³ ).

  The resin block used in the present invention preferably contains polyurethane. Polyurethane is a polymer usually synthesized based on polyisocyanate polyaddition reaction or polymerization reaction. The compound used as the object of the polyisocyanate is a compound having polyfunctional active hydrogen, that is, two or more polyhydroxy or amino group-containing compounds. Examples of the polyisocyanate include tolylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, tolidine diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate, but are not limited thereto. The polyhydroxy is typically a polyol, and examples of the polyol include polyether polyol, polypropylene glycol, polytetramethylene ether glycol, epoxy resin-modified polyol, polyester polyol, acrylic polyol, polybutadiene polyol, and silicone polyol. Of these, polyurethane obtained by combining tolylene diisocyanate, diphenylmethane diisocyanate as the polyisocyanate, and polypropylene glycol and polytetramethylene ether glycol as the polyol is preferable because it has excellent moldability and is widely used.

  Moreover, it is preferable that the resin block used for this invention contains the polymer polymerized from the vinyl compound other than the polyurethane. Specific examples of the vinyl compound include methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, methyl (α-ethyl) acrylate, ethyl (α-ethyl) acrylate, propyl (α-ethyl) acrylate, Butyl (α-ethyl) acrylate, 2-ethylhexyl methacrylate, isodecyl methacrylate, n-lauryl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl Methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, methacrylic acid, glycidyl methacrylate , Ethylene glycol dimethacrylate, fumaric acid, dimethyl fumarate, diethyl fumarate, dipropyl fumarate, maleic acid, dimethyl maleate, diethyl maleate, dipropyl maleate, acrylonitrile, acrylamide, vinyl chloride, styrene, α-methylstyrene, etc. Is mentioned.

  Among them, preferred vinyl compounds are methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, methyl (α-ethyl) acrylate, ethyl (α-ethyl) acrylate, propyl (α-ethyl) acrylate, butyl. (Α-ethyl) acrylate. The polymer polymerized from the vinyl compound in the present invention is a polymer obtained by polymerizing the above vinyl compound, specifically, polymethyl methacrylate, polyethyl methacrylate, polypropyl methacrylate, poly (n-butyl). Methacrylate), polyisobutyl methacrylate, polymethyl (α-ethyl) acrylate, polyethyl (α-ethyl) acrylate, polypropyl (α-ethyl) acrylate, polybutyl (α-ethyl) acrylate, poly (2-ethylhexyl methacrylate), polyiso Decyl methacrylate, poly (n-lauryl methacrylate), poly (2-hydroxyethyl methacrylate), poly (2-hydroxypropyl methacrylate), poly (2-hydroxyethyl acrylate), poly (2-hydroxypropyl methacrylate) Acrylate), poly (2-hydroxybutyl methacrylate), polydimethylaminoethyl methacrylate, polydiethylaminoethyl methacrylate, polymethacrylic acid, polyglycidyl methacrylate, polyethylene glycol dimethacrylate, polyfumaric acid, dimethyl polyfumarate, diethyl polyfumarate, polyfumaric acid Examples include dipropyl, polymaleic acid, dimethyl polymaleate, diethyl polymaleate, dipropyl polymaleate, polyacrylonitrile, polyacrylamide, polyvinyl chloride, polystyrene, and poly (α-methylstyrene). Among these, preferred polymers include polymethyl methacrylate, polyethyl methacrylate, polypropyl methacrylate, poly (n-butyl methacrylate), polyisobutyl methacrylate, polymethyl (α-ethyl) acrylate, polyethyl (α-ethyl) acrylate, polypropyl. (Α-Ethyl) acrylate and polybutyl (α-ethyl) acrylate can increase the hardness of the resin block, and can improve the planarization characteristics of the polishing pad that is sliced from the resin block. The content of the polymer polymerized from the vinyl compound in the present invention is preferably 45% by weight or more and 65% by weight or less. When the content is less than 45% by weight, the hardness of the polishing pad is lowered, which is not preferable. When the content exceeds 65% by weight, the elasticity of the pad is impaired, which is not preferable. The content of the polymer polymerized from the polyurethane or vinyl compound in the polishing pad can be measured by a pyrolysis gas chromatography / mass spectrometry method for the polishing pad. The apparatus that can be used in this method is a double shot pyrolyzer “PY-2010D” (manufactured by Frontier Laboratories) as a thermal decomposition apparatus, and “TRIO-1” (manufactured by VG) as a gas chromatograph / mass spectrometer. Can do.

As a method for producing the resin block used in the present invention, a preferable method is foaming having closed cells having an average cell diameter of 1000 μm or less in advance and a density in the range of 0.1 to 1.0 (g / cm ³ ). After the vinyl compound is swollen in the polyurethane block, the vinyl compound is polymerized in the foamed polyurethane block. In this method, a structure having closed cells can be formed, a resin block in which a polymer polymerized from polyurethane and a vinyl compound is integrated can be produced, and a polishing pad produced from the obtained resin block Is preferable because it can reduce local unevenness flatness and global level difference. A more preferable method for producing a resin block is that a vinyl compound is added to a foamed polyurethane block having closed cells having an average cell diameter of 500 μm or less in advance and having a density in the range of 0.4 to 0.9 (g / cm ³ ). After swelling, the vinyl compound is polymerized in the foamed polyurethane block. In this method, a structure having closed cells can be formed, a resin block in which a polymer polymerized from polyurethane and a vinyl compound is integrated can be produced, and a polishing pad produced from the obtained resin block It is preferable because local unevenness flatness and global level difference can be reduced. In the foamed polyurethane block in the present invention, the combination and optimum amount of polyisocyanate, polyol, catalyst, foam stabilizer, and foaming agent can be determined by the hardness, the cell diameter and the foaming ratio. As the foamed polyurethane block, a foamed polyurethane is preferably used.

  As a method of polymerizing the vinyl compound in the foamed polyurethane block after swelling the vinyl compound in the foamed polyurethane block, after swelling the vinyl compound together with the photodegradable radical initiator, exposing the light to polymerize, Examples include a method in which a vinyl compound is swollen together with a thermally decomposable radical initiator and then polymerized by applying heat, and a method in which a vinyl compound is swollen and then polymerized by emitting an electron beam or radiation.

  The sliced product (polishing layer) obtained as described above is laminated with a cushion layer to form a polishing pad. Adhesive material is used for bonding. The material of the adhesive is not particularly specified, but is preferably a rubber-containing system or an acrylic resin-containing system. It is also possible to form a polishing pad without a cushion layer. The polishing pad manufactured in this way is used by being fixed to the polishing surface plate via an adhesive or the like. As these adhesive materials, “442JS” manufactured by 3M, “7021” manufactured by Teraoka Seisakusho, “G9000” manufactured by Sony Chemical Co., Ltd., and the like can be used, but are not limited thereto.

  Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the examples. In this example, the thickness of the slice (polishing layer) sliced from the resin block was measured using a caliper. The surface property of the sliced surface was visually observed to confirm the presence or absence of knife marks.

Example 1
30 parts by weight of polypropylene glycol, 40 parts by weight of diphenylmethane diisocyanate, 0.5 parts by weight of water, 0.3 parts by weight of triethylamine, 1.7 parts by weight of a silicone foam stabilizer and 0.09 parts by weight of tin octylate are mixed with a RIM molding machine. Then, it was discharged into a mold and subjected to pressure molding. A foamed polyurethane block having a length of 500 mm, a width of 500 mm, and a thickness of 10.0 mm (micro rubber A hardness = 37 degrees, density: 0.74 (g / cm ³ ), Closed cell average diameter: 40 μm) was prepared. The foamed polyurethane block was immersed in methyl methacrylate to which 0.2 parts by weight of azobisisobutylnitrile was added for 76 hours, the foamed polyurethane block storing this methyl methacrylate was sandwiched between glass plates and heated at 60 ° C. for 10 hours, Heated at 120 ° C. for 2 hours.

After heating, it was removed from the glass plate, vacuum dried at 50 ° C., and then both surfaces were ground to produce a resin block having a thickness of 12.0 mm. The density of the obtained resin block was 0.81 (g / cm ³ ), the average closed cell diameter was 45 μm, and the polymethyl methacrylate content in the resin block was 50% by weight.

  The obtained resin block was put into an oven at 100 ° C. for 1 hour for preheating. Prepare a band knife slicer equipped with a rubber heater on the inlet table of the band knife slicer, set the temperature of the rubber heater to 100 ° C, and polish the band knife with a diamond grinder while performing the above preheating The resin block was sliced. The thickness accuracy of the sliced material (polishing layer) was divided into 25 equal parts, and the thickness variation was measured with calipers. The thickness variation was ± 0.03 mm. The knife trace on the slice surface was not visible. The polishing pad was prepared by pasting the sliced pad and the cushion layer together with an adhesive “7021” manufactured by Teraoka Seisakusho.

Example 2
A slice (polishing layer) was obtained in the same manner as in Example 1 except that the temperature at the time of preheating was 80 ° C. The thickness variation of the polishing layer divided into 25 equal parts was ± 0.04 mm. The knife trace on the slice surface was not visible.

Comparative Example 1
A slice (polishing layer) was obtained in the same manner as in Example 1 except that the band knife was not polished during slicing. The thickness variation of the polishing layer divided into 25 equal parts was ± 0.10 mm. In addition, knife marks were visible on the slice surface.

Comparative Example 2
A slice (polishing layer) was obtained in the same manner as in Example 1 except that the temperature at the time of preliminary overheating was 50 ° C. and the set temperature of the rubber heater was 50 ° C. The thickness variation of the polishing layer divided into 25 equal parts was ± 0.15 mm. In addition, knife marks were visible on the slice surface.

Comparative Example 3
The experiment was performed in the same manner as in Example 1 except that the temperature at the time of preliminary overheating was 50 ° C., the set temperature of the rubber heater was 50 ° C., and the resin block was sliced without polishing the band knife. When the 30 mm band knife entered the resin block, the rotation of the knife stopped and the entire surface could not be sliced.

Claims (7)

A band knife type slicer having means for heat-retaining and / or heating an object to be sliced. A method for producing a polishing pad, comprising the step of slicing a polishing layer from a resin block containing polyurethane using the band knife type slicer according to claim 1. The method for producing a polishing pad according to claim 2, wherein the resin block is preheated to 60 ° C. or higher and 140 ° C. or lower and sliced. The method of manufacturing a polishing pad according to claim 2 or 3, wherein the band knife type slicer comprises means for polishing the blade, and the resin block is sliced while polishing the blade. The method for producing a polishing pad according to claim 2, wherein the resin block includes a polymer polymerized from polyurethane and a vinyl compound. The method for producing a polishing pad according to claim 5, wherein the vinyl compound is obtained using a compound having a structure represented by the following general formula (1).
General formula (1)
CH ₂ = CR ¹ COOR ²
(Here, R ¹ is a methyl group or an ethyl group, and R ² is a methyl group, an ethyl group, a propyl group, or a butyl group.) 7. The polishing pad according to claim 2, wherein the polishing pad is used for CMP and is composed of a single polishing layer, or a polishing pad in which a polishing layer and another layer are laminated. Method of manufacturing a polishing pad.