JP5594295B2 - Cylindrical member polishing apparatus and cylindrical member polishing method - Google Patents

Description

  The present invention relates to a polishing apparatus for polishing an outer peripheral surface of a cylindrical workpiece made of a hard and brittle material.

  The cylindrical member of the hard and brittle material to be polished of the present invention includes, for example, a silicon block that is a material for obtaining a silicon wafer by slicing with a wire saw, and the silicon block is made of a single crystal. Alternatively, a silicon ingot made of a polycrystal is cut into a cylindrical shape by cutting with a band saw or a wire saw. If the required accuracy regarding the external dimensions after the cutting is high, the surface layer is ground.

  A single crystal silicon block obtained by a chocolate ski method (CZ method) or a polycrystalline silicon block obtained by a casting method or the like is a silicon wafer that is sliced by a wire saw in the next step. If there are microcracks or micro unevenness in the surface layer portion, the silicon wafer manufactured at the time of slicing is likely to be cracked or chipped. Therefore, in Patent Document 1 and Patent Document 2, the surface layer portion of the silicon block is polished and removed. It is disclosed that minute unevenness (and microcracks) present in the surface layer portion is removed to improve the product yield of the silicon wafer. In particular, Patent Document 1 discloses that the surface roughness Ry of 10 to 20 μm before polishing is flattened to 3 to 4 μm by polishing and removing a surface layer portion of a silicon block having a thickness of 50 to 100 μm and 200 μm or less from the surface. Has been. Patent Document 3 is disclosed as a silicon block polishing apparatus.

Patent Document 1: JP-A-2005-347712 Patent Document 2: JP-A-2002-252188 Patent Document 3: JP-A-2009-233794

  Patent Documents 1 to 3 each disclose a method and apparatus for polishing a surface layer portion of a silicon block of a quadrangular columnar member, and perform polishing processing of a surface layer portion of a cylindrical member to be performed by the present invention. No device is disclosed. Moreover, the diameter of a cross section may change with the cylindrical member which the cross section does not form a perfect circle, or the manufacture shape dispersion | variation of a cylindrical member, and the apparatus which grind | polishes these efficiently is desired.

  The present invention provides a polishing apparatus and a polishing method that can satisfy the above-mentioned requirements and can polish the outer peripheral surface of a hard and brittle material such as a cylindrical silicon block, which is a workpiece, with a single apparatus. I will provide a.

  Connecting to the rotating means of the workpiece, clamping means for clamping the both end faces of the workpiece, polishing means for polishing the outer peripheral surface of the workpiece, the workpiece to the polishing means, A moving means for relatively moving in a longitudinal direction orthogonal to the cross-sectional direction which is a substantially circular shape of the workpiece, and a height position detecting means for detecting the height position of the finished polished product and the workpiece before polishing. A polishing device for polishing a surface layer portion of an outer peripheral surface of a cylindrical workpiece, comprising: a control means for performing polishing by calculating the height position and processing conditions; The polishing means includes a grindstone whose tip rotates in contact with the outer peripheral surface of the workpiece, and a hair material containing abrasive grains or an elastic body containing abrasive grains, and the tip is provided on the outer peripheral surface of the workpiece. At least one polishing brush that rotates in contact with each other , The polishing brush and the grinding wheel are arranged consecutively provided along the axis of the cylindrical workpiece. (First invention)

Further, in the cylindrical member polishing apparatus according to the first invention, the polishing means includes a first grindstone and a polishing brush arranged continuously along the axis of the columnar workpiece. The polishing means, and a grinding wheel arranged continuously along the axis of the cylindrical workpiece and the second polishing means of the polishing brush,
Each of the grindstone and the polishing brush of the first polishing means, and each of the grindstone and the polishing brush of the second polishing means make a pair, and each of the pair of the grindstone and the polishing brush has a circular cross section of the workpiece. The first polishing means and the second polishing means are arranged in the same plane, the axial centers of the first polishing means and the second polishing means are arranged so as to coincide with the radial direction of the workpiece, and the first core forming a pair The axis of the polishing means and the axis of the second polishing means are arranged so as to intersect at the center of the cross section of the workpiece so as to form a predetermined angle θ. (Second invention)

  Further, in the cylindrical member polishing apparatus according to the first or second invention, the calculation in the control means is performed by calculating a difference in height position from two or more axial centers in the circumferential direction of the workpiece. At least a calculation, a calculation of a difference between a height position of the finished product after polishing and a height position of the workpiece before polishing, and a calculation for setting other processing conditions than the input processing conditions Including any one (third invention)

  Further, in the columnar member polishing apparatus according to any one of the first to third inventions, a plurality of bristle materials containing abrasive grains are planted in a ring shape at the bottom of the polishing brush. Structure. (Fourth invention)

  Further, in the cylindrical member polishing apparatus according to any one of the first to third inventions, the polishing brush has a polishing tool mounting plate in which a base of a polishing tool in which a plurality of bristle materials containing abrasive grains are bundled is used. It is a structure that is fixed to a plurality. (Fifth invention)

  Further, in the cylindrical member polishing apparatus according to any one of the first to third inventions, the polishing brush has an elastic body containing abrasive grains arranged in a ring shape at the bottom of the polishing brush means. It is the structure that was established. (Sixth invention)

  Moreover, it is a cylindrical member grinding | polishing apparatus as described in any one of 1st thru | or 3rd invention, Comprising: The particle size of the abrasives which form the said grindstone is F60- # 800. (Seventh invention)

  The cylindrical member polishing apparatus according to any one of the first to third inventions, wherein the abrasive grains mixed in the bristle material or the elastic body used in the polishing means have a particle size of F180 to #. Two or more kinds of polishing means having hair materials or elastic bodies having different particle sizes are selected, and polishing means having different abrasive particle sizes are polished in the order of coarse particles to fine particles. It continues along the axial center of a column-shaped workpiece so that it may process. (Eighth invention)

  The cylindrical member polishing apparatus according to any one of the first to third inventions, wherein the abrasive grains mixed in the bristle material or the elastic body used in the polishing means have a particle size of F180 to #. The polishing means having a bristle material or an elastic body having a particle size of approximately 2000 is provided continuously along the axis of the cylindrical workpiece. (9th invention)

  Further, the cylindrical member is polished by the cylindrical member polishing apparatus according to any one of the first to third inventions, and microcracks existing below 100 μm are removed from the surface layer of the workpiece. The surface roughness Ry of the polished surface is 3 μm or less. (Tenth invention)

  Further, the columnar member described in the tenth invention is a silicon block or ceramics. (Eleventh invention)

  Further, in the method for polishing a cylindrical member by the cylindrical member polishing apparatus according to any one of the first to third aspects, the workpiece clamped by the clamping unit is rotated by the rotating unit, and the A dimension adjustment step of adjusting the dimension of the workpiece by contacting and rotating the tip of the grindstone with the outer peripheral surface of the workpiece and moving the polishing means relative to the workpiece; After the dimension adjustment step, the tip of the polishing brush is brought into contact with and rotated on the outer peripheral surface of the workpiece, and the polishing means is moved relative to the workpiece to polish the workpiece. And a finishing process for performing processing. (Twelfth invention)

  Moreover, in the grinding | polishing method of the cylindrical member as described in 12th invention, the particle size of the abrasive grain mixed with the bristle material used for the said polishing brush or an elastic body is F180- # 2000, Comprising: The particle size differs. Select two or more types of polishing means having a hair material or an elastic body, and polish the polishing means with different abrasive grain sizes so that the abrasive grains are polished in the order of coarse to fine. Polish along the axis of the workpiece. (13th invention)

  Moreover, in the grinding | polishing method of the cylindrical member as described in 12th invention, the particle size of the abrasive grain mixed with the bristle material or elastic body used for the said polishing brush is F180- # 2000, Comprising: The particle size is substantially Polishing means having the same bristle material or elastic body is continuously provided along the axis of the cylindrical workpiece and polished. (14th invention)

Effects of the Invention The grindstone and polishing brush provided in the polishing means are in contact with the outer peripheral surface of a cylindrical workpiece, and the workpiece is rotated by the rotating means, whereby the outer peripheral surface of the workpiece is polished. can do. Further, since the workpiece clamped by the clamping means is rotated in the circumferential direction by the rotating means (hereinafter referred to as rotating means (for workpiece)), the outer peripheral surface of the workpiece is made uniform. It can be polished. First, the grindstone is used to grind the workpiece to the vicinity of the target dimension, and then the surface can be removed with a polishing brush to remove microcracks present on the surface layer portion of the outer peripheral surface (first and second). 12 inventions). In addition, the processing time is shortened by arranging the first polishing means and the second polishing means along the axis of the workpiece by the grindstone and the polishing brush (second invention). The said dimension adjustment process can be performed efficiently by making the particle size of the abrasives which form the said grindstone into F60- # 800 (JIS R6001: 1998) (7th invention). Further, the polishing brush has a structure in which a plurality of bristle materials containing abrasive grains are planted in a ring shape at the bottom of the polishing brush, and a base of a polishing tool in which a plurality of bristle materials containing abrasive grains are bundled A structure in which a plurality of fixing members are fixed to the tool mounting plate and a structure in which an elastic body containing abrasive grains is arranged in a ring shape at the bottom of the polishing brush means can be selected as appropriate (fourth and fifth). , Sixth invention). The abrasive grains can be appropriately selected according to the purpose from the range of F180 to # 2000 (JIS R6001: 1998). When a polishing means having a plurality of polishing brushes is used, each abrasive brush contains When the grain size of the abrasive grains is different, the workpieces are arranged in order from “rough” to “fine” so that the workpieces pass through and are processed, so that the workpieces can be processed in a single polishing process. Microcracks and irregularities in the surface layer can be removed (eighth and thirteenth inventions), and multi-stage processing such as “rough” → “thin” described above is not required, and one-step processing is required. When the surface is obtained (for example, when the surface of the workpiece W has micro cracks and the surface roughness is not greatly different from the required value, the processing is performed only with “fine”). Both polishing means should be approximately the same. And the processing time can be shortened (the ninth and fourteenth inventions). In this specification, the term “substantially the same particle size” of the abrasive and the abrasive means that the abrasive and the abrasive having “the same particle size can be obtained” in addition to the “the same particle size” abrasive. It is a concept that includes.

The workpiece before processing is clamped, the height position between the shaft core and the outer peripheral surface of the workpiece is measured at two or more locations, and the difference between them is calculated, so that the deviation of the clamping location from the shaft core can be understood. . In addition, after starting polishing, a standard piece (hereinafter referred to as “master work”) of the finished polishing process is detected by the height position detecting means and stored by the polishing means by the polishing means, and stored. By detecting the height position of the workpiece and calculating the difference between the height position detected by the master work and the height position detected by the workpiece, based on the calculation result, the tip of the polishing means The distance to the workpiece can be corrected, and polishing of a plurality of workpieces can be performed continuously. Further, by performing calculations for setting other machining conditions than the inputted machining conditions, machining can be performed accurately with simple input. At least one of the operations performed by the control means is performed. The “input” described in the first invention means information input (stored) to the control means manually (operator), information automatically input (stored) to the control means, manual or / and automatic Any of the information input (stored) after the calculation based on the information input (stored) in (1) is included. (Third invention)

  Further, by using the polishing apparatus, it is possible to obtain a columnar member in which 100 μm microcracks are removed from the surface layer and the surface roughness Ry is 3 μm or less. As the columnar member, a hard and brittle material such as a silicon block or ceramics can be suitably used (tenth and eleventh inventions).

It is explanatory drawing which shows the whole polishing apparatus of this invention. It is explanatory drawing which shows one example of the polishing brush of this invention. 2A is a partially cutaway cross-sectional view seen from the front, and FIG. 2B is a view taken along line AA in FIG. 2A. It is explanatory drawing showing the other example of the polishing brush of this invention. FIG. 3A is a schematic diagram in which hair material is planted at the bottom, and FIG. 3B is a schematic diagram in which an elastic body is installed at the bottom. It is explanatory drawing which shows the process of this invention. FIG. 4A is an explanatory view showing a position adjusting step, and FIG. 4B is an explanatory view showing a finishing step. It is explanatory drawing which shows the 3rd Embodiment of this invention. FIG. 5A is an explanatory view for explaining the arrangement of the first polishing means and the second polishing means viewed from the cross-sectional direction of the workpiece, and FIG. 5B is a first view viewed from the longitudinal direction of the workpiece. It is explanatory drawing explaining arrangement | positioning of a grinding | polishing means and a 2nd grinding | polishing means.

  The configuration of the polishing apparatus and the polishing process according to the first embodiment of the present invention will be described with reference to the drawings. The polishing apparatus according to the first embodiment is a polishing apparatus for a cylindrical member in which one grindstone is connected to two polishing brushes having different polishing roughnesses. In the following description, the vertical and horizontal directions refer to vertical and horizontal directions in the drawings unless otherwise specified.

  A schematic view of a cylindrical member polishing apparatus is shown in FIG. The columnar member polishing apparatus 1 according to the present embodiment includes a base 11 on which the workpiece W is placed, a lifting / lowering means 12 for moving the base 11 up and down, and a clamp for clamping the workpiece W A means 13, a rotating means (for a workpiece) (not shown) connected to the clamping means for rotating around the axis of the workpiece W, and the clamped workpiece W are shown in the figure. Moving means 14 for moving the sandwiched workpiece W to the machining position by moving in the left-right direction and the outer periphery of the workpiece W for measuring the height position of the workpiece W from the axis. The surface height position detecting means 15, the polishing means 20, and a control means (not shown) are configured. The polishing means 20 includes a grindstone 21 connected to a rotating means (for a grindstone) 21M and a polishing brush 22 connected to a rotating means (for a polishing brush) 22M.

  Prior to machining the workpiece W, the height position detection means 15 measures the height position (reference position) from the axis of the master workpiece to the outer peripheral surface in order to calculate the machining amount of the workpiece W. And stored in a control means (not shown). First, both ends of the master work are clamped by the clamping means 13. When the master work is sandwiched by the sandwiching means 13, for example, the master work is placed on the base 11 having a V-shaped groove. By placing the master work in the groove, the center in the left-right direction (in the direction perpendicular to the paper surface in FIG. 1) about the axis of the master work can always be substantially the same position. Further, the mounting position of the base can be finely adjusted by the elevating means 12 in the vertical direction in the figure. The master work is placed on the base, and the holding shafts 13a and 13b of the holding means 13 are advanced to hold the both ends of the master work. Then, the base 11 is removed from the master work by lowering the base 11 by the lifting means 12.

  The clamping means 13 is rotated by the rotating means (for the workpiece), that is, rotates around the axis of the clamping shafts 13a and 13b, so that the axis of the clamping shafts 13a and 13b and the axis of the master work are The alignment must be adjusted to match. After clamping the master work by the clamping means 13, the height position detecting means 15 measures the outer peripheral surface height position H1 of the master work, and then rotates the master work (for example, 180 degrees) to increase the height in the rotated state. The position H2 is measured. In the present embodiment, three height position detecting means 15 are arranged in the longitudinal direction (left and right direction in the figure) of the master work, and the height position is measured at each position. When the difference between the measured H1 and H2 is calculated and H1 and H2 are not substantially the same, the base 11 is raised and the master work is placed on the base 11, and then the holding shafts 13a and 13b are moved. Retract each and release the master work. Based on the calculation result, the vertical position of the base, that is, the vertical position of the master work is adjusted by raising or lowering the lifting / lowering means 12, and then the master work is clamped by the clamping means 13 again. After removing the base 11 from the master work, H1 and H2 of the master work are similarly measured. When H1 and H2 are substantially the same, the centering process of the master work is completed. Further, the height position H at this time is stored in the control means as a reference position. Thereafter, the base 11 is raised, and after placing the master work on the base 11, the holding shafts 13 a and 13 a are retracted to release the master work, and then the master work is removed from the base 11. The reference position measurement process is completed.

  Next, after placing the workpiece W on the base 11, the workpiece W is clamped by the clamping means 13 in the same manner as described above, and then the height of the workpiece W is detected by the height position detection means 15. The position h1 is measured. Thereafter, the workpiece W is rotated, and the height position h2 of the workpiece W is measured. The rotation angle can be arbitrarily set according to the shape of the surface of the workpiece W or the like. That is, when the rotation angle is 180 °, two height positions (h1, h2) with respect to the circumferential direction of the workpiece W are obtained, and when the rotation angle is 120 °, three height positions (h1, h2, h3). ) Can be measured at four height positions (h1, h2, h3, h4) when the rotation angle is 90 °. In this embodiment, the rotation angle is 90 °, and three height position detection means 15 (15a, 15b, 15c) are used, and h1 (h1a, h1b, h1c), h2 (h2a, h2b, h2c), h3. A total of 12 height positions (h3a, h3b, h3c) and h4 (h4a, h4b, h4c) were measured. The base 11 is raised and the workpiece W is moved to the base so that the difference between the respective height positions (h1, h2, h3, h4) becomes the smallest as in the above-described master work centering adjustment. 11, after holding the workpiece W is released and the base 11 is raised or lowered to adjust the vertical position of the base 11, that is, the vertical position of the workpiece W, After being sandwiched again by the sandwiching means 13 and removing the base 11 from the workpiece W, the height positions h1, h2, h3, h4 of the workpiece W are measured again. The height positions h1, h2, h3, and h4 of the workpiece W after adjustment need to be larger than the reference position H. Further, since the workpiece W rotates around the axis of the workpiece W during polishing, the height positions h1, h2, h3, h4 are the same or different even if there is a difference. It must be within a range that does not affect the rotation, and is calculated and determined by the control means.

  The workpiece W that has passed the determination is polished by the grindstone 21. The grindstone 21 sets the height positions h1, h2, h3, and h4 of the workpiece W so as to be close to the reference position H in consideration of the polishing amount by the polishing brush in the next process (this height position is defined as h). Used) for the purpose of polishing the workpiece W. The particle size of the abrasive material constituting the grindstone 21 is F60 to # 800, preferably # 100 to # 500 (definition of the particle size of the abrasive material is based on JIS standard R6001: 1998), depending on the material and dimensions of the workpiece W. It can be suitably selected from the range.

  Processing conditions (rotation speed of the grindstone 21, rotation speed of the polishing brush 22, rotation speed of the workpiece W, transfer speed of the workpiece W, machining allowance (processing of the workpiece) inputted in advance to the control means The cutting amount of the tip of the polishing brush with respect to the surface S, hereinafter simply referred to as “the cutting amount”), and the reference position H and the height positions h1, h2, h3, h4 are subjected to arithmetic processing, and the grindstone 21 Is moved downward, that is, the grindstone 21 is moved in the direction of the machining surface S. Thereafter, the grindstone 21 is driven by driving a rotating means (for grindstone) 21M (motor in this embodiment) connected to the grindstone 21. Further, the workpiece W is rotated by driving a rotating means (for a workpiece) connected to the clamping means 13 (a motor in this embodiment). Object W is its axis While rotating to the center and moving from the left to the right in the figure by the moving means 14, the polishing surface of the grindstone 21 comes into contact with the processing surface S of the workpiece W, and polishing by the grindstone 21 based on the processing conditions. (Position adjustment step, see FIG. 4A.) The difference between the reference position H and the height positions h1, h2, h3, and h4 is large, and a desired amount of processing can be obtained by one polishing. If not, polishing may be performed by reciprocating the moving means or by lowering the grindstone 21 step by step each time the moving means is reciprocated. And the driving of the rotating means (for the grindstone) 21M is stopped, and then the workpiece W is moved to a position before starting the polishing.

Next, the workpiece W is polished by the polishing brush 22 (polishing brushes 22a and 22b). In the present embodiment, the polishing brush 22 having the form shown in FIG. 2 is used. The bristle material 24a made of synthetic resin such as nylon mixed with abrasive grains is bundled, and one end thereof is fixed in the abrasive tool holder 24b to form the abrasive tool 24, and the base of the abrasive tool 24 is rotated by a rotating means (abrasive tool). For attaching to the polishing tool mounting plate 23 connected to 22M and rotating horizontally, the lower end contacts the processing surface S of the workpiece W for polishing, and when the polishing tool 24 is worn, The polishing tool 24 can be removed from the polishing tool mounting plate 23 and replaced with a new polishing tool 24.
The grain size of the abrasive grains mixed in the bristle material is preferably selected from the range of the abrasive grain size or less and F180 to # 2000 (definition of the grain size of the abrasive grains is based on JIS standard R6001: 1998). .

  In this embodiment, the grindstone 21 and the two polishing brushes 22a and 22b are arranged along the axis of the workpiece W. Further, the abrasive grains contained in the bristle materials of the polishing brushes 22a and 22b are different in particle size, and the grindstone 21, the large abrasive particle brush 22a, and the small abrasive particle brush 22b are illustrated. In FIG. 1, they were arranged in order from the left to the right. The polishing brush 22a having a large particle size removes most of the scratches and irregularities generated on the surface of the workpiece W (processing surface S) by polishing with the grindstone 21, and most of the microcracks present on the surface layer portion of the workpiece W. The polishing brush 22b having a small particle size can remove microcracks existing in the surface layer portion of the workpiece W (finishing processing).

  An arithmetic process is performed based on the processing conditions inputted in advance to the control means, the reference position H and the height position h, and the polishing brush 22 is moved in the vertical direction, that is, the polishing brush 22 is moved in the direction perpendicular to the processing surface S. Move. Thereafter, the rotating means (for polishing brush) 22M (motor in this embodiment) connected to the polishing brush 22 is driven to rotate the polishing brush 22 around the axis of the polishing surface. Further, by moving the workpiece W from the left to the right in the drawing by the moving means 14, each polishing surface of the polishing brush 22 comes into contact with the processing surface S of the workpiece W, and based on the processing conditions. Polishing with the polishing brush 22 is performed. Since the workpiece W is polished from the left to the right in the drawing as described above, polishing can be performed in the order of rough finishing and finishing (finishing step; see FIG. 4B). . After the polishing brush 22 is completely polished, the polishing brush 22 is moved (raised) to a position before starting polishing, and the driving of the rotating means (for polishing brush) 22M is stopped. Thereafter, the workpiece W is moved to a position before starting polishing, the driving of the rotating means (for the workpiece) is stopped, and the rotation of the workpiece W is stopped.

  Thereafter, after raising the base 11 and placing the workpiece W, the clamping shafts 13a and 13b are retracted in the same manner as described above to release the clamping of the workpiece W by the clamping means 13. By removing the object W, a series of polishing is completed.

  In the case of processing a plurality of workpieces W, after the workpieces W are newly placed on the base 11, polishing is performed through the same steps (paragraph 0029 to paragraph 0035). That is, by first measuring the height position of the master workpiece and setting the height position as a reference position, it is possible to polish a plurality of workpieces W thereafter.

  In the present embodiment, the workpiece W is moved in the left-right direction in the figure, but the grindstone 21 and the polishing brushes 22a and 22b may be moved, or the grindstone 21 and the polishing brushes 22a and 22b and the workpiece W are moved. Both of them may be moved.

In the present embodiment, the machining conditions are manually input to the control means, but the machining conditions that are manually input and the machining position that is not input from the automatically input (stored) outer peripheral surface height position of the workpiece W are input. The polishing may be performed by calculating the condition by the control means.
For example, the moving speed of the workpiece W may be calculated by the control means by inputting the cutting amount and the rotation speed of the polishing means 2, or the cutting amount may be calculated from the other processing conditions and height position by the control means. You may make it calculate. Then, polishing can be performed based on these calculation results.

  The processing conditions to be input are not limited to the items described in this embodiment. For example, the type of the polishing means 20 and the state of the workpiece may be input, and the calculation by the control means may be combined based on these.

  The polishing brush 22 as the polishing means 20 is not limited to that shown in FIG. 2, and a polishing tool 25 made of a bristle material 25a mixed with abrasive grains is directly attached and fixed to the polishing tool mounting plate 23. When the 25 wears, the polishing tool mounting plate 23 may be exchanged together, or without using the polishing tool 25, a bristle material 24c made of synthetic resin such as nylon containing abrasive grains is ring-shaped at the bottom of the polishing means 20. (See FIG. 3A. The upper diagram is a front view, and the lower diagram is a bottom view (a view taken along the line AA in the front view)). Further, for example, when the polishing means 20 comes into contact with a corner of a columnar body that forms an angle of approximately 90 ° during the processing of ceramics or the like, chipping occurs due to contact between the polishing means 20 and the workpiece W ( If the occurrence of chipping becomes a problem, an elastic body 24d made of a synthetic resin containing abrasive grains may be arranged in a ring shape at the bottom of the polishing means 20 (see FIG. 3B). The figure shows a front view, and the lower figure shows a bottom view (a view taken along the line AA in the front view). The elastic body 24d in this case is, for example, a resin bulk body having a relatively soft hardness, a resin bulk body such as polyurethane or urethane having a large number of bubbles inside, and a fibrous elastic body entangled with each other. It may be a thing. In a bulk body of a resin having a relatively soft hardness, the resin itself functions as a buffer material. In the bulk body of resin having bubbles, the bubbles inside serve as a buffer material. In an elastic body containing abrasive grains and entangled with each other, the elastic bodies are entangled with each other, so that air is included in these aggregates, and this air layer functions as a cushioning material. In any case, the type of synthetic resin, the content of abrasive grains, and the like are appropriately selected so that the elastic body 24d maintains an appropriate elastic force when it contacts the workpiece. The grain size of the abrasive grains mixed in the bristle material 24c and the elastic body 24d is desirably selected from the range of F180 to # 2000 as in the present embodiment.

  When the scratches or irregularities are large, or when the microcracks are deep, the grain size of the abrasive grains contained in the polishing brush 22 that performs rough finishing is compared with the grain size of the abrasive grains contained in the polishing brush 22 that performs finishing. When it is very large, one or more polishing brushes (intermediate finishing process) including an intermediate particle size may be disposed between the polishing brushes 22a and 22b. That is, three or more polishing brushes may be arranged along the axis of the workpiece W.

  When it is not necessary to perform rough finishing, such as when the scratches or irregularities are small or when the microcracks are shallow, only the polishing brush 22b for finishing may be disposed.

  When it is necessary to increase the polishing amount (processing amount) by the grindstone 21, or when the rough finishing process by the polishing brush 22 can be performed by the grindstone 21, a plurality of grindstones 21 can be arranged.

Below, the result of the evaluation test using the apparatus of 1st Embodiment is demonstrated.
First, using the apparatus of the first embodiment, a cylindrical single crystal silicon block, which is the workpiece W, is processed into a size of φ175 mm × 500 mm, and microcracks existing in the surface layer portion of the workpiece W Then, the surface roughness was removed by removing the irregularities on the surface.
Thereafter, when the silicon block was sliced with a wire saw to form a silicon wafer, it was evaluated whether or not the generation rate of defective products due to cracking or chipping of the silicon wafer could be reduced.

The surface layer portion of the workpiece W before polishing processing has microcracks having a depth of 80 to 100 μm, and the surface roughness is (Ry) 9 to 11 μm (the definition of Ry is according to JIS standard B0601: 1994). In addition, when the silicon block that was not polished was cut (sliced) with a wire saw to form a silicon wafer, the incidence of defective products due to cracks and chips was 5 to 6%.
Next, the silicon block, which is the workpiece (W), is polished using the polishing apparatus described in the first embodiment to remove microcracks and irregularities and reduce the surface roughness, and then the silicon block The incidence of defective products due to cracks and chipping when a block was sliced with a wire saw to form a silicon wafer was evaluated.

  The processing conditions in this evaluation test were set as shown in Table 1, and after inputting this into the control means, three single crystal silicon blocks were processed. The results are shown in Table 2. Thus, by processing using the polishing apparatus in the first embodiment, the diameter of the single crystal silicon block is processed to a target dimension, and the maximum depth of the microcracks is 0.7-0. 9 μm, the surface roughness was a flat surface portion Ry 0.7 to 1.0 μm (average: Ry 0.9 μm), and microcracks and surface roughness could be reduced. In Table 2, the data described in the column “after polishing with a grindstone” indicates data in a state of “after polishing with a grindstone and before processing with a polishing brush”. Yes, it shows data in the middle of the polishing process. When all three of the silicon blocks were sliced with a wire saw to form a silicon wafer, the incidence of defective products due to cracks, chips, etc. was 3-4%. The maximum depth of the microcracks is 3.0 μm or less, preferably 2.3 μm or less. When the maximum depth is 3.0 μm or more, the incidence of defective products increases. Further, when the maximum depth is 2.3 μm or less, there is little influence on the occurrence rate of defective products due to cracks / chips when sliced into a thickness of several tens of μm to form a silicon wafer. In this evaluation test, the maximum depth was 0.9 μm, which was significantly less than 2.3 μm, which affects the incidence of defective products.

  Next, a polishing apparatus according to the second embodiment will be described. The polishing apparatus according to the second embodiment has an apparatus configuration that is used when a surface state required by one-stage processing can be obtained without requiring multi-stage processing such as finishing after rough finishing. . Here, only differences from the first embodiment will be described.

  For example, when the microcracks before the polishing process on the surface of the workpiece W are minute and the surface roughness before the polishing process is not significantly different from the required value, the abrasive grains contained in the polishing brushes 22a and 22b The particle size can be substantially the same as that of the polishing brush 22b used for the finishing process. By arranging a plurality of polishing brushes having substantially the same abrasive grains contained in the polishing brush 22, the processing time can be shortened.

  Next, a polishing apparatus according to a third embodiment will be described with reference to FIG. The polishing apparatus according to the third embodiment has an apparatus configuration in which the first polishing means 30 and the second polishing means 40 are arranged so as to shorten the processing time. Here, only differences from the first embodiment will be described.

  In the polishing apparatus according to the third embodiment, the first polishing means 30 and the second polishing means 40 are arranged in the same cross section (circular) surface of the workpiece W. The axial centers of the first polishing means 30 and the second polishing means 40 are arranged so as to coincide with the radial direction of the workpiece W, and the first polishing means 30 and the second polishing means 40 are mutually connected. In order to avoid interference, the axis of the first polishing means 20 and the axis of the second polishing means 20 intersect at the center of the cross section of the workpiece W so as to form a predetermined angle θ. Is arranged. (See FIG. 5A) This angle θ can be arbitrarily set as long as the first polishing means 30 and the second polishing means 40 do not interfere with each other. For example, the angle θ can be set to 180 °, and the shaft core of the first polishing means 30 and the shaft core of the second polishing means 40 can be disposed so as to completely coincide with each other. With such a configuration, the workpiece W is polished while rotating in the circumferential direction, so that the processed surface of the workpiece has two locations of the first polishing means 30 and the second polishing means 40. In this case, the processing time is shortened.

  Also, in the polishing apparatus according to the third embodiment, as in the polishing apparatus according to the first embodiment, as shown in FIG. 5B (in the figure, θ is described as 180 °), Arbitrary quantities of the grindstones 31 and 41 and the polishing brushes 32 and 42 included in the first polishing means 30 and the second polishing means 40 can be arranged. That is, each of the grindstones 31 and 41 and the polishing brush may be one each, or a plurality of them may be arranged along the axis of the workpiece W. For example, the figure shows a state where one grindstone 31 and 41 and two polishing brushes 32 and 42 (32a, 32b and 42a, 42b) are arranged, respectively. In this case, the grindstone (first polishing means) 31 and the grindstone (second polishing means) 41 in the first row and the polishing brush A in the second row in order from the left along the axis of the workpiece W. (First polishing means) 32a and polishing brush A (second polishing means) 42a, and in the third row, polishing brush B (first polishing means) 32b and polishing brush B (second polishing means) 42b, Is arranged. At that time, the particle size of the abrasive forming the grindstone and the particle size of the abrasive grains contained in the bristle material or the elastic body provided in each polishing brush are determined by the grindstone (first polishing means) 31 and the grindstone (first grindstone). 2 polishing means) 41, polishing brush A (first polishing means) 32a and polishing brush A (second polishing means) 42a, polishing brush B (first polishing means) 32b and polishing brush B (second polishing means) The polishing means) 42b are substantially the same, that is, the grindstone and the polishing brush in the same row are set to have substantially the same polishing power. Similarly to the second embodiment, when the processing can be performed by the polishing means having one polishing power, the abrasive grains contained in the hair material or the elastic body provided in all the polishing brushes. The particle size can be made substantially the same.

  In the polishing apparatus according to the third embodiment described above, the configuration in which the two polishing units, the first polishing unit 20 and the second polishing unit 20, are arranged in the circumferential direction of the workpiece W has been described. However, the present invention is not limited to this, and an arbitrary number of polishing means may be arranged in accordance with the arrangement space, the target processing time, etc. as long as the respective polishing means do not interfere with each other.

  The present invention is not limited to the processing of a cylindrical silicon block, and can be suitably used for all hard and brittle materials such as ceramics.

1 Polishing equipment
11 base
12 Lifting means
13 Clamping means
13a, 13b Holding shaft
13c, 13d clamping part
14 Means of transportation
15, 15a, 15b, 15c Height position detection means
20 Polishing means
21 Whetstone
21M Rotating means (for grinding stone)
22, 22a, 22b Polishing brush
22M Rotating means (for polishing brush)
30 First polishing means
31 Whetstone (first polishing means)
31M Rotating means (for grinding stone (first polishing means))
32, 32a, 32b Polishing brush (first polishing means)
40 Second polishing means
41 Whetstone (second polishing means)
41M Rotating means (for grinding stone (second polishing means))
42, 42a, 42b Second polishing means
W Work piece S Work surface

Claims (6)

A clamping means connected to the rotating means of the workpiece and clamping both end faces of the workpiece;
Polishing means for polishing the outer peripheral surface of the workpiece;
Moving means for moving the workpiece relative to the polishing means relative to a longitudinal direction perpendicular to a cross-sectional direction of the workpiece that is substantially circular;
A height position detecting means for detecting the height position of the finished product before polishing and the workpiece before polishing;
Control means for performing polishing by calculating the height position and processing conditions and calculating this,
A polishing apparatus for polishing an outer peripheral surface of a cylindrical workpiece having
The polishing means includes a grindstone whose tip rotates in contact with the outer peripheral surface of the workpiece, a hair material containing abrasive grains, or an elastic body containing abrasive grains, and a tip on the outer peripheral surface of the workpiece. Each having at least one polishing brush rotating in contact with each other,
The grindstone and the polishing brush are arranged continuously along the axis of a cylindrical workpiece,
The calculation in the control means includes the calculation of the difference in height position from two or more axial centers in the circumferential direction of the workpiece, the height position of the polished product and the workpiece before polishing. And calculating at least one of the height position differences of
The polishing brush has a structure in which a plurality of base parts of a polishing tool in which a plurality of hair materials containing abrasive grains are bundled are fixed to a polishing tool mounting plate.
An apparatus for polishing a cylindrical member. The polishing means is connected to the first polishing means of the grindstone and the polishing brush arranged continuously along the axis of the columnar workpiece, and along the axis of the columnar workpiece. A whetstone arranged and arranged and a second polishing means of a polishing brush,
Each of the grindstone and the polishing brush of the first polishing means, and each of the grindstone and the polishing brush of the second polishing means make a pair, and each of the pair of the grindstone and the polishing brush has a circular cross section of the workpiece. The first polishing means and the second polishing means are arranged in the same plane, the axial centers of the first polishing means and the second polishing means are arranged so as to coincide with the radial direction of the workpiece, and the first core forming a pair The axis of the polishing means and the axis of the second polishing means are arranged so as to intersect at the center of the cross section of the workpiece so as to form a predetermined angle θ. The cylindrical member polishing apparatus as described. The operation in the control unit, the polishing apparatus of the cylindrical member according to claim 1, characterized in that it comprises a computation for setting the other process conditions from the inputted processing conditions. The particle size of the abrasive forming the grindstone is F60 to # 800,
The abrasive used in the polishing brush has a grain size of F180 to # 2000 mixed with the bristle material or elastic body, and two or more types of abrasive brushes having different bristle material or elastic body are selected. the abrasive grain granularity is different polishing brush, as abrasive particle size is polished in the order of "fine" from the "coarse", that you have been continuously provided along the axis of the cylindrical workpiece The cylindrical member polishing apparatus according to any one of claims 1 to 3, wherein the polishing apparatus is a cylindrical member. The particle size of the abrasive forming the grindstone is F60 to # 800,
The abrasive brush mixed with the bristle material or elastic body used in the abrasive brush has a particle size of F180 to # 2000, and the abrasive brush having the bristle material or elastic body having substantially the same particle size has a cylindrical covering. The cylindrical member polishing apparatus according to any one of claims 1 to 3, wherein the polishing apparatus is provided continuously along an axis of a workpiece. The method for polishing a cylindrical member by the cylindrical member polishing apparatus according to any one of claims 1 to 3, wherein the workpiece clamped by the clamping unit is rotated by the rotating unit,
A dimension adjusting step of adjusting the dimension of the workpiece by bringing the tip of the grindstone into contact with and rotating the outer peripheral surface of the workpiece and moving the polishing means relative to the workpiece; ,
After the dimension adjustment step, the tip of the polishing brush is brought into contact with and rotated on the outer peripheral surface of the workpiece, and the polishing means is moved relative to the workpiece to polish the workpiece. A finishing process for performing processing,
The dimension adjustment step includes a height position detection step of detecting a height position of the workpiece before polishing and the workpiece before polishing,
The height position and processing conditions are inputted, and a control step of calculating this and performing polishing processing,
The calculation in the control step includes the calculation of the difference in height position from two or more axial cores in the circumferential direction of the workpiece, the height position of the polished product and the workpiece before polishing. A method for polishing a cylindrical member, comprising: calculating at least one of the height position differences .

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