WO2012029194A1

WO2012029194A1 - Polishing device for columnar member and polishing method therefor

Info

Publication number: WO2012029194A1
Application number: PCT/JP2010/067915
Authority: WO
Inventors: 茂棚橋; 靖雄野田
Original assignee: 新東工業株式会社
Priority date: 2010-09-01
Filing date: 2010-10-13
Publication date: 2012-03-08
Also published as: KR20130092375A; JP5565417B2; JPWO2012029194A1; TWI566887B; CN101972982A; CN101972982B; TW201210743A; KR101601007B1

Abstract

Provided are an inexpensive polishing device having high polishing capability for removing minute cracks present in a columnar surface layer portion produced from a hard and brittle material and fine polishing capability for removing asperities on the surface to obtain finer surface roughness, and an polishing method therefor. A polishing device for a columnar member is provided with: a clamping means coupled to a rotating means for an object to be processed to clamp both end surfaces of the object to be processed; a polishing means for performing polishing processing with the edge of a polishing tool thereof rotating in contact with a processing surface; a moving means for relatively moving the polishing means in the longitudinal direction orthogonal to the cross-sectional direction of the object to be processed with respect to the object to be processed; a height position detecting means for storing the height position of the processing surface of the object to be processed, the height position being detected before the polishing processing; and a control means for performing the polishing processing by subjecting the height position stored by the position detecting means and the amount of cutting by the edge of the polishing means to arithmetic processing.

Description

Cylindrical member polishing apparatus and polishing method thereof

The present invention relates to a polishing apparatus for polishing a surface layer portion (hereinafter simply referred to as “surface layer portion” unless otherwise specified) 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 the surface layer portion of the silicon block of 50 to 100 μm to 200 μm from the surface. Has been. Patent Document 3 is disclosed as a silicon block polishing apparatus.

Patent Document 1: Japanese Patent Application Laid-Open No. 2005-347712 Patent Document 2: Japanese Patent Application Laid-Open No. 2002-252188 Patent Document 3: Japanese Patent Application Laid-Open No. 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.

The present invention provides a polishing apparatus capable of satisfying the above-mentioned requirements and capable of polishing a surface layer portion of a hard and brittle material such as a cylindrical silicon block, which is a workpiece, with a single apparatus, and a polishing method therefor The purpose is to provide.

In the first invention, there is provided a polishing apparatus for polishing a surface layer portion of an outer peripheral surface of a cylindrical workpiece, the clamping device being connected to a rotating means of the workpiece and sandwiching both end faces of the workpiece. A polishing means for polishing while the tip of the polishing means contacts and rotates on the outer peripheral surface of the workpiece; and the longitudinal direction perpendicular to the cross-sectional direction of the workpiece, the polishing means for the workpiece. A moving means for relatively moving in the direction, a height position detecting means for detecting the height position of the finished product before polishing and the workpiece before polishing, and the height position and processing conditions are input, Control means for performing a polishing process by calculation, and the calculation is a calculation of a difference between a height position of the finished product of polishing process and a height position of the workpiece before polishing, or an input processing condition Calculation to set other machining conditions, or Is any combination of these, using a technical means of.

According to a second aspect of the present invention, there is provided the cylindrical member polishing apparatus according to the first aspect, wherein the polishing means is a polishing brush, and the polishing brush has a bristle containing abrasive grains at the bottom of the polishing brush. The technical means that a plurality of rings are planted in a ring shape is used.

In a third invention, the cylindrical member polishing apparatus according to the first invention, wherein the polishing means is a polishing brush, and the polishing brush bundles a plurality of bristle materials containing abrasive grains. The technical means that the base part of the polishing tool has a structure in which a plurality of the base parts of the polishing tool are installed on the polishing tool mounting plate is used.

According to a fourth invention, there is provided the cylindrical member polishing apparatus according to the first invention, wherein the polishing means is a polishing brush, and the polishing brush has an elastic body containing abrasive grains of the polishing brush. The technical means of having a structure arranged in a ring shape at the bottom is used.

According to a fifth aspect of the invention, there is provided the cylindrical member polishing apparatus according to any one of the second to fourth aspects, wherein a plurality of the polishing means are provided along the axis of the cylindrical workpiece. The technical means that they are arranged in series is used.

According to a sixth aspect of the invention, there is provided the cylindrical member polishing apparatus according to any one of the second to fourth aspects, wherein the polishing means is disposed within the same plane of the circular cross section of the workpiece. The first polishing means and the second polishing means are arranged, and the shafts 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 polishing means A technical means is used in which the axis of the 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.

According to a seventh invention, there is provided the cylindrical member polishing apparatus according to the sixth invention, wherein the first polishing means and the second polishing means are respectively provided along the axis of the cylindrical workpiece. The technical means that a plurality are arranged in series is used.

In the eighth and ninth inventions, the cylindrical member polishing apparatus according to the fifth or seventh invention, wherein the particle size of the abrasive grains mixed with the bristle material or the elastic body used in the polishing means is F180. ~ # 2000, 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 selected from coarse to fine. A technical means is used that is connected along the axial center of a cylindrical workpiece so as to polish in order.

The tenth and eleventh invention is the cylindrical member polishing apparatus according to the fifth or seventh invention, wherein the particle size of the abrasive grains mixed with the bristle material or elastic body used in the polishing means is F180. A technical means is used in which polishing means having a hair material or an elastic body having a particle size substantially equal to # 2000 is continuously provided along the axis of a cylindrical workpiece.

In a twelfth invention, a cylindrical member polished by the cylindrical member polishing apparatus according to the first invention, wherein microcracks existing in a surface layer of the workpiece of 100 μm or less are removed and polished. The technical means that the surface roughness Ry of the processed surface is 3 μm or less is used.

The thirteenth invention uses the technical means of the columnar member according to the twelfth invention, wherein the columnar member is a silicon block or ceramics.

In a fourteenth aspect of the invention, there is provided a method for polishing a cylindrical member by the cylindrical member polishing apparatus according to the first aspect of the invention, wherein the workpiece sandwiched by the clamp means is rotated by the rotating means. ,
Contact and rotate the tip of the polishing means to the outer peripheral surface of the workpiece,
And the technical means of performing polishing by moving the polishing means relative to the workpiece is used.

In the fifteenth and sixteenth inventions, there is provided a method of polishing a cylindrical member by the cylindrical member polishing apparatus according to the fifth or seventh invention, wherein the bristle material or elastic body used in the polishing means is used. The abrasive grains to be mixed are F180 to # 2000, and two or more kinds of polishing means having hair materials or elastic bodies having different particle sizes are selected, and the polishing means having different abrasive grain sizes are selected as the abrasive grain sizes. Is technically connected and polished along the axial center of a cylindrical workpiece so that polishing is performed in the order of “rough” to “fine”.

In the seventeenth and eighteenth inventions, there is provided a method for polishing a cylindrical member by the cylindrical member polishing apparatus according to the fifth or seventh invention, wherein the bristle material or elastic body used in the polishing means is used. Abrasive means having a bristle material or an elastic body having a particle size of F180 to # 2000 mixed with substantially the same particle size is continuously provided along the axis of the cylindrical workpiece to be polished. The technical means to do is used.

The polishing means comes into contact with the outer peripheral surface of a cylindrical workpiece, and the workpiece rotates by the rotating means, whereby the surface layer portion of the workpiece can be polished. Further, since the workpiece sandwiched between the clamping means is rotated in the circumferential direction by the rotating means (hereinafter referred to as rotating means (for workpiece)), the surface layer portion of the workpiece is made uniform. It can be polished. Further, during this polishing process, the polishing means is moved relative to the workpiece in the longitudinal direction of the workpiece, that is, in a direction orthogonal to the substantially circular cross section, so that the entire workpiece is Can be uniformly polished. The term “substantially circular” includes not only a circular shape but also an ellipse or the like, which includes a slightly non-circular state caused by distortion in the manufacturing process of the workpiece (columnar member).

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. The height position of the workpiece is detected, the difference between the height position detected by the master workpiece and the height position detected by the workpiece is calculated by the control means, and the tip of the polishing means is calculated based on the calculation result. By correcting the distance to the workpiece, polishing of a plurality of workpieces can be performed continuously. The “input” described in the first invention is 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.

Further, by using a polishing brush composed of a bristle material containing abrasive grains as the polishing means, a sufficient polishing force can be secured and damage to the workpiece can be suppressed. This is because the hair material is more flexible than other polishing methods such as polishing with a polishing stone, etc., so that damage to the workpiece can be suppressed, and the hair material contains abrasive grains. Therefore, a sufficient polishing power can be secured.

Further, the length of the hair material exposed from the bottom of the polishing means can be adjusted by arbitrarily setting the position (vertical direction) of the polishing tool mounting plate on which the polishing tool in which a plurality of the hair materials are bundled is implanted. Can do. That is, the length of the hair material that is always exposed can be kept constant by moving the position of the polishing tool mounting plate downward according to the wear of the hair material.

In addition, since the object that contacts the workpiece during polishing is an elastic body, damage due to the workpiece contacting with the polishing brush can be reduced.

Further, the grain size of the abrasive grains mixed with the bristle material is F180 to # 2000 (JIS R6001: 1998), and one polishing means is a polishing brush in which substantially the same particle diameter is mixed. That is, the polishing means having a bristle or elastic body having a larger particle size has a higher polishing ability and can accurately remove microcracks existing in the surface layer portion of the workpiece, and the bristle or elastic body having a smaller particle size. As the polishing means is provided, the surface layer can be finely polished to remove irregularities.

In addition, by arranging a plurality of polishing means along the axis of the cylindrical workpiece, the polishing means is appropriately selected according to the type and purpose of the workpiece and processed. be able to. That is, select two or more kinds of polishing means having hair materials or elastic bodies having different particle sizes, and the particle sizes contained in the hair materials or elastic bodies provided in the polishing means are in the order of "rough" to "fine", By arranging the workpieces so as to pass and process, microcracks and irregularities in the surface layer portion of the workpiece can be removed by a single polishing process. Further, when the surface required by one-step processing can be obtained without requiring multi-step processing such as “rough” → “thin” as described above (for example, micro cracks on the surface of the workpiece W are minute). In the case where the surface roughness is not significantly different from the required value, the processing is performed only with “thin”), and the grain size of the abrasive grains contained in the bristle material or the elastic body provided in the two or more polishing means provided in series. The processing time can be shortened by making all the polishing means substantially the same.

Further, in the polishing means composed of the first polishing means and the second polishing means arranged in the same plane of the circular cross section of the workpiece, the shaft cores of the first polishing means and the second polishing means are to be processed. Arranged so as to coincide with the radial direction of the workpiece, the axis of the first polishing means and the axis of the second polishing means intersect at the center of the cross section of the workpiece so as to form a predetermined angle θ. By arranging in this way, the processing time can be shortened.
Further, a plurality of the first polishing means and the second polishing means are arranged in series along the axial center of the cylindrical work piece, so that it corresponds to the kind and purpose of the work piece. The processing time described above can be shortened.

Further, by using the polishing apparatus, a cylindrical member having 100 μm microcracks removed from the surface layer and having a surface roughness Ry of 3 μm or less can be obtained. As the cylindrical member, a hard and brittle material such as a silicon block or ceramics can be suitably used.

It is explanatory drawing which shows the whole polishing apparatus of this invention. It is explanatory drawing which shows one example of the grinding | polishing means of this invention. FIG. 2A is a partially cutaway cross-sectional view seen from the front, and FIG. 2B is a bottom view. It is explanatory drawing showing the other example of the grinding | polishing means of this invention. FIG. 3A is a schematic diagram in which a 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 a flowchart for demonstrating 1st Embodiment in this invention. It is a flowchart for demonstrating 1st Embodiment in this invention. It is a flowchart for demonstrating 1st Embodiment in this invention. It is a flowchart for demonstrating 1st Embodiment in this invention. It is explanatory drawing showing the 3rd Embodiment in this invention. It is explanatory drawing which shows 3rd Embodiment in this invention.

The details of the configuration and operation of the polishing apparatus 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 provided with two or more (three) polishing means having different polishing roughnesses.

FIG. 1 shows a polishing unit 1 stopped at a position before polishing start at the right end in the drawing, and clamping means 5 disposed on the left and right of the workpiece W indicated by a one-dot chain line. 6A, a gripping portion 6A attached to the tip of a reference-side clamp shaft 12A that slides by driving the cylinder of the clamp means 5, and a right-hand side of the workpiece W, and a driven-side clamp shaft 12B. The front view of the grinding | polishing apparatus provided with the holding part 6B attached to the front-end | tip is shown. In FIG. 1, the gripping portions 6A and 6B are disposed at the retracted positions, respectively, and show an open state in which the workpiece W is not sandwiched. The polishing unit 1 detects the height position of three polishing means 2 each connected to a rotating means (for polishing means) 2a and a processing surface (outer peripheral surface) P of the workpiece W before starting polishing. And a height position detecting means 3 for this purpose. The polishing unit is transferred from the left side to the right side in FIG. 1 when polishing is performed by a transfer unit (not shown) that transfers the polishing unit 2 relative to the workpiece W. The polishing means 2 is arranged in order from the right for rough polishing, medium polishing, and finish polishing. That is, the grain size of the abrasive grains contained in the bristle provided in the polishing means is “rough” → “fine” in order from the right. The height position detection means 3 is provided on the right side of the rough polishing means 2.

The rough polishing polishing means 2 in the above-described triple polishing means 2 is provided for the purpose of scraping most of the microcracks existing in the surface layer portion with a large polishing ability, and the intermediate polishing polishing means 2 is a band saw or a wire saw. It is provided for the purpose of removing irregularities on the surface generated when cutting and refining the surface roughened by the rough polishing, and the polishing means 2 for final polishing is provided for the purpose of final adjustment of the surface roughness. If the removal of the surface irregularities and the adjustment of the surface roughness are completed at the intermediate polishing stage, the polishing means 2 may be duplicated without using the polishing means 2 for final polishing.

Prior to processing the workpiece W, the master work is used to set the height position at which the polishing processing of the polishing means 2 is started by the height position detection means 3.
In order to set the height position, first, both ends of the master work are clamped by the clamp means 5. When the master work is sandwiched by the clamping means 5, it is preferable to place it on a base (not shown) having a V-shaped groove, for example. By installing the master work in the groove, the center of the master work in the left-right direction in the drawing can always be substantially the same position. Furthermore, it is more preferable that the base has adjustment means (not shown) for finely adjusting the installation position in the vertical direction in the figure. The master work is placed on the base, and the clamp shafts 12A and 12B of the clamp means 5 are advanced, so that the gripping portions 6A and 6B sandwich the both ends of the master work. Thereafter, the base is removed. In the present embodiment, the installation and removal of the base having the V-shaped groove is performed by moving the base up and down in the drawing. (See Figure 4)

The clamp means 5 is rotated by a rotating means (for a workpiece) (not shown), that is, rotates around the axis of the clamp shafts 12A and 12B. Therefore, the clamp shaft 12A and the clamp shaft 12A viewed from the end face side of the master workpiece The centering adjustment must be made so that the axis of the gripping portions 6A and 6B at the tip of 12B and the axis of the master work coincide. The master work is held while performing this adjustment by the adjusting means. After using the master work placed at the machining position in this way and measuring the height position of the outer peripheral surface of the master work by the height position detecting means 3, the master work is removed from the clamping means 5. In the present embodiment, after clamping the master work by clamping means 5, by the height position detection means 3 provided in the polishing unit 1 measures the outer circumferential surface height position H ₁ of the master work, then rotating the master work ( for example, 180 degrees) is to measure the height position of H ₂ at a rotational state. It calculates a difference of an H ₁ and H _2, if H ₁ and H ₂ is not substantially the same, respectively retracting the clamp shaft 12A and 12B after raising the base to release the holding of the master workpiece. After adjusting (raising / lowering) the height position of the base (vertical stop position for clamping the master work with the clamp means 5) based on the calculation result, the master work is again held with the clamping means 5 Then, H ₁ and H _{2 of} the sandwiched master work are measured. When H ₁ and H ₂ are substantially the same, the master work centering step is completed. (See Figure 5)

After the master work centering process is completed, the polishing unit 1 moves to the right in FIG. Then, the base is raised, the clamp shafts 12A and 12B are retracted to release the master work, and the master work is placed on the V-shaped groove of the base. Thereafter, the master work is replaced with the workpiece W, and the centering process is performed in the same manner as in the master work. When the centering step is completed, the polishing unit is moved to the left side in FIG. The outer peripheral surface height position H of the master workpiece is stored in the control means by the master workpiece centering step, and the outer peripheral surface height position h of the workpiece W is stored in the control device by the centering step of the workpiece W. .

Processing conditions (rotation speed of the polishing means 2, rotation speed of the workpiece W, transfer speed of the polishing unit 1, cutting depth (with respect to the processing surface P of the workpiece W), and the outer peripheral surface previously input to the control means Arithmetic processing is performed based on the height positions H and h, and the polishing unit 1 is moved in the vertical direction, that is, in the distance direction between the polishing unit and the processing surface P.

The polishing means 2 and the workpiece W are rotated by the control means 13 at a predetermined rotational speed based on the processing conditions. Thereafter, similarly, the polishing unit 1 is moved to the right side in FIG. 1 by the control means 13 at a predetermined moving speed. By this movement, the workpiece surface P of the workpiece W and the tip of the rotating polishing means 2 come into contact with each other, and polishing is performed. As described above, since the polishing means 2 are arranged in the order of “rough” → “fine” in order from the right to the left in FIG. 1, this movement causes “rough polishing” → “medium polishing” → “finish polishing”. Is done. After the polishing unit has moved to a predetermined position (rightmost end), the base is raised, and thereafter the clamping means 12A and 12B are retracted, the clamping of the workpiece W is released, and the workpiece W is taken out. This completes the polishing process.

In the case of processing a plurality of workpieces W, after the workpieces W are newly installed on the base, polishing is similarly performed through a clamping process of the workpieces and a centering process of the workpieces. That is, by first measuring the height position of the master work, a plurality of workpieces W can be polished thereafter. (See Figs. 6 and 7)

In the present embodiment, the polishing unit 1 is moved in the horizontal direction in the figure, but the workpiece W may be transferred, or both the polishing unit 1 and the workpiece W may be transferred.

In the present embodiment, the machining conditions are manually input to the control means. However, the machining conditions that have not been input to the control means are determined based on the manually input machining conditions and the automatically input (stored) outer peripheral surface height position. The polishing process may be performed by calculating the above. For example, the moving speed of the workpiece W is controlled by inputting the cutting amount of the tip of the polishing means with respect to the processing surface P of the workpiece (hereinafter simply referred to as “the cutting amount”) and the rotation speed of the polishing means 2. It may be calculated by the means 13, or the cutting amount may be calculated by the control means 13 from other processing conditions and height positions. Then, polishing can be performed based on these calculation results.

The processing conditions to be input are not limited to the items in this embodiment. For example, the type of the polishing means 2 and the state of the workpiece may be input, and the calculation by the control means 13 may be combined based on these.

2 (A) and 2 (B) show an example of a polishing brush that is the polishing means 2, and a bristle material 10a made of synthetic resin such as nylon mixed with abrasive grains is bundled to form a polishing tool 10. A base portion of the polishing tool 10 is connected to a rotating means (for polishing tool) 2a and is detachably attached to a polishing tool mounting plate 11 which rotates horizontally, and a lower end rotates in contact with a processing surface P of the workpiece W. When the polishing tool 10 is worn, the polishing tool 10 can be removed from the polishing tool mounting plate 11 and replaced with a new polishing tool 10. The polishing brush as the polishing means 2 is not limited to that shown in FIG. 2, and the polishing tool 10 made of the bristle material 10a mixed with abrasive grains is directly attached and fixed to the polishing tool mounting plate 11, and the polishing brush is polished. When the tool 10 is worn, the polishing tool mounting plate 11 may be replaced together, or the polishing tool 10 is not used, and a bristle material 10a made of synthetic resin such as nylon containing abrasive grains is attached to the bottom of the polishing means 2 (See FIG. 3 (A)). Further, for example, when the polishing means 2 comes into contact with a corner of a columnar body that forms an angle of about 90 ° during processing, such as ceramics, chipping occurs due to contact between the polishing means 2 and the workpiece W ( If the occurrence of chipping becomes a problem, an elastic body 10b made of a synthetic resin containing abrasive grains may be arranged in a ring shape at the bottom of the polishing means (see FIG. 3B). The elastic body 10b 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 that contains abrasive grains and is 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 10b maintains an appropriate elastic force when it contacts the workpiece. (See FIG. 3. In both FIGS. 3 (A) and 3 (B), the upper diagram represents the front and the lower diagram represents the bottom.)
The grain size of the abrasive grains mixed in the bristle material or elastic body is preferably selected from the range of F180 to # 2000 (the definition of the grain size of the abrasive grains is based on JIS standard R6001: 1998).

Evaluation Test Below, the workpiece W is a cylindrical single crystal silicon block (φ175 mm × 500 mm), and the surface layer portion of the workpiece W is processed using the polishing apparatus of the present invention and exists in the surface layer portion. Micro-cracks and surface irregularities are removed to reduce the surface roughness and evaluate the polishing effect. When a silicon wafer is formed by slicing the silicon block with a wire saw, the silicon wafer is cracked or chipped. The results of evaluation tests that were able to reduce the incidence of defective products due to the above will be described.

Micro-cracks having a depth of 80 to 100 μm are present on the surface layer of the workpiece W before polishing, and the surface roughness is (Ry) 9 to 11 μm (Ry is defined by JIS standard B0601: 1994). When the silicon block was cut (sliced) with a wire saw to form a silicon wafer, the incidence of defective products due to cracks, chips, etc. was 5 to 6%.

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 the surface roughness is reduced, and then the silicon block is processed into a wire saw. The results of reducing the incidence of defective products due to cracks and chips when slicing and forming a silicon wafer will be described.

The processing conditions in this evaluation test were set as shown in Table 1, and after inputting this into the control means 13, three single crystal silicon blocks were processed. The results are shown in Table 2. Thus, by performing processing using the polishing apparatus in the first embodiment, the depth of the microcracks present in the surface layer portion of the single crystal silicon block and the unevenness of the outer peripheral surface can be significantly reduced. As a result, as shown in Table 2, the maximum depth of the microcracks is 0.7 to 0.9 μm, the surface roughness is the plane portion Ry 0.7 to 1.0 (average: Ry0.9), Removal of microcracks and irregularities and surface roughness could be reduced. And, 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 and chips was reduced by 2%. 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 does not require multi-stage processing such as “rough” → “thin”, and has an apparatus configuration used when a surface required by one-stage processing can be obtained. 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 greatly different from the required value, the polishing means 10 (polishing brush) is the “ Processing can be performed only by “for intermediate polishing” or “for final polishing”. In such a case, only one polishing means 10 including a hair material or an elastic body containing abrasive grains having a particle size suitable for the purpose of polishing is installed and processed.

Further, the processing time can be shortened by making the particle sizes included in the hair material or the elastic body provided in the triple polishing means 2 in the first embodiment substantially the same.

Next, a polishing apparatus according to a third embodiment will be described with reference to FIGS. The polishing apparatus according to the third embodiment has an apparatus configuration in which the polishing means 2 is 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 21a and the second polishing means 22a are arranged in the plane of the same cross section (circular shape) of the workpiece W.
The shaft centers of the first polishing means 21a and the second polishing means 22a are arranged so as to coincide with the radial direction of the workpiece W, and the first polishing means 21a and the second polishing means 22a are mutually connected. In order not to interfere, the axis of the first polishing means 21a and the axis of the second polishing means 22a intersect at the center of the cross section of the workpiece W so as to form a predetermined angle θ. Is arranged. (Refer to FIG. 8) This angle θ can be arbitrarily set as long as the first polishing means 21a and the second polishing means 22a do not interfere with each other, but the angle θ is set to 180 ° and the first It is also possible to arrange so that the axis of the polishing means 21a and the axis of the second polishing means 22a completely coincide with each other and face each other.
By adopting such a configuration, the workpiece W is polished while rotating in the circumferential direction, so that the processed surface of the workpiece is two places, the first polishing means 21a and the second polishing means 22a. 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, FIG. 9 (the right diagram in FIG. 9 is a view of the workpiece W as viewed from the front, The figure on the left is a view of the workpiece W as seen from the left side.) As shown in FIG. 2, the first polishing means 21a and the second polishing means 22a are connected in the longitudinal direction of the workpiece W, or It is also possible to arrange as a triple (FIG. 9 shows a state of triple arrangement).
In this case, in order from the left along the longitudinal direction of the workpiece W, the first polishing means 21a and the second polishing means 22a in the first row, the first polishing means 21b and the second polishing in the second row. The polishing means 22b and the first polishing means 21c and the second polishing means 22c in the third row are arranged.
At that time, the abrasive grains contained in the hair material or the elastic body provided in each polishing means are substantially the same in the polishing means 21a and 22a, the polishing means 21b and 22b, and the polishing means 21c and 22c. The polishing power should be approximately the same.
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 means. The particle size can be made substantially the same.

In the above-described polishing apparatus according to the third embodiment, the configuration in which the two polishing units, the first polishing unit 21a and the second polishing unit 22a, are installed 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 installation space, the target processing time, etc. as long as the polishing means do not interfere with each other.

As described above, in the present embodiment and the evaluation test, the case where the silicon block is ground has been described as an example. However, the present invention is not limited to the silicon block, and is suitable for all hard and brittle materials such as ceramics. Can be used.

In addition, in this specification, "the particle size is substantially the same" of the abrasive grains is a concept including an abrasive particle of "a particle size capable of obtaining an equivalent polishing effect" in addition to the abrasive particles of "the same particle size".

1 Polishing unit 2 Polishing means 2a Rotating means (for polishing tool)
3 Height position detection means 5 Clamping means 6A Grip part (reference position side)
6B Grip part (driven side)
DESCRIPTION OF SYMBOLS 10 Polishing tool 10a Hair material 10b Elastic body 11 Polishing tool mounting plate 12A Clamp axis | shaft (reference position side)
12B Clamp shaft (driven side)
13 Control means 14A Rotation means (for workpiece) (reference position side)
14B Rotating means (for workpiece) (driven side)
W Work piece P Work surface

Claims

A polishing apparatus for polishing a surface layer portion of an outer peripheral surface of a cylindrical workpiece,
A clamping means connected to the rotating means of the workpiece and sandwiching both end faces of the workpiece;
Polishing means for polishing while the tip of the polishing means contacts and rotates on the outer peripheral surface of the workpiece;
Moving means for moving the polishing means relative to the workpiece in a longitudinal direction perpendicular to a cross-sectional direction of the workpiece, which 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,
With
The calculation is a calculation of the difference between the height position of the finished product of polishing and the height position of the workpiece before polishing, or a calculation for setting other processing conditions from the input processing conditions, or those A polishing apparatus for a cylindrical member, characterized in that any one of the combinations is provided.
2. The polishing apparatus according to claim 1, wherein the polishing means is a polishing brush, and 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. Polishing apparatus for cylindrical members.
The polishing means is a polishing brush, and the polishing brush has a structure in which a plurality of base parts of a polishing tool in which a plurality of bristle materials containing abrasive grains are bundled are planted on a polishing tool mounting plate. The cylindrical member polishing apparatus according to claim 1.
The circle according to claim 1, wherein the polishing means is a polishing brush, and the polishing brush has a structure in which an elastic body containing abrasive grains is arranged in a ring shape at the bottom of the polishing brush. Polishing device for columnar members.
The cylindrical member according to any one of claims 2 to 4, wherein a plurality of the polishing means are arranged continuously along the axis of a cylindrical workpiece. Polishing equipment.
The polishing means comprises a first polishing means and a second polishing means arranged in the same plane of the circular cross section of the workpiece, and the shaft centers of the first polishing means and the second polishing means are The workpiece is arranged so as to coincide with the radial direction of the workpiece, and the axis of the first polishing means and the axis of the second polishing means form a predetermined angle θ so that the cross-sectional center of the workpiece 5. The cylindrical member polishing apparatus according to claim 2, wherein the cylindrical member polishing apparatus is disposed so as to intersect each other.
7. The cylindrical shape according to claim 6, wherein a plurality of the first polishing means and the second polishing means are arranged in series along the axial center of the cylindrical workpiece. A device polishing apparatus.
The abrasive used in the polishing means has a particle size of F180 to # 2000 mixed with the abrasive or the elastic body, and two or more types of polishing means having the hair or elastic body having different particle sizes are selected. The polishing means having different grain sizes are arranged along the axis of the cylindrical workpiece so that the abrasive grains are polished in the order of “rough” to “fine”. The cylindrical member polishing apparatus according to claim 5.
The abrasive used in the polishing means has a particle size of F180 to # 2000 mixed with the abrasive or the elastic body, and two or more types of polishing means having the hair or elastic body having different particle sizes are selected. The polishing means having different grain sizes are arranged along the axis of the cylindrical workpiece so that the abrasive grains are polished in the order of “rough” to “fine”. 8. The cylindrical member polishing apparatus according to claim 7.
The abrasive used in the polishing means has a particle size of F180 to # 2000 mixed with the bristle material or elastic body, and the abrasive means having the hair material or elastic body having substantially the same particle size has a cylindrical covering. 6. The cylindrical member polishing apparatus according to claim 5, wherein the cylindrical member polishing apparatus is provided continuously along the axis of the workpiece.
The abrasive used in the polishing means has a particle size of F180 to # 2000 mixed with the bristle material or elastic body, and the abrasive means having the hair material or elastic body having substantially the same particle size has a cylindrical covering. 8. The cylindrical member polishing apparatus according to claim 7, wherein the cylindrical member polishing apparatus is provided continuously along the axis of the workpiece.
The cylindrical member polishing apparatus according to claim 1 is used to remove microcracks that are 100 μm or less from the surface layer of the workpiece, and that the surface roughness Ry of the polished surface is 3 μm or less. A cylindrical member characterized.
The columnar member according to claim 12, wherein the columnar member is a silicon block or a ceramic.
The cylindrical member polishing apparatus according to claim 1, wherein the workpiece sandwiched between the clamp means is rotated by the rotating means, and
Contact and rotate the tip of the polishing means to the outer peripheral surface of the workpiece,
A polishing method for a cylindrical member, wherein polishing is performed by moving the polishing means relative to the workpiece.
6. The cylindrical member polishing apparatus according to claim 5, wherein the abrasive used in the polishing means or the abrasive mixed with the elastic body has a particle size of F180 to # 2000 and has a different particle size. Two or more kinds of polishing means having an elastic body are selected, and polishing means having different abrasive grain sizes are polished in order of the grain size of the abrasive grains from “rough” to “fine”. A method for polishing a cylindrical member, characterized by being provided by polishing along an axial core.
8. The cylindrical member polishing apparatus according to claim 7, wherein the abrasive used in the polishing means or the abrasive mixed with the elastic body has a particle size of F180 to # 2000 and has a different particle size. Two or more kinds of polishing means having an elastic body are selected, and polishing means having different abrasive grain sizes are polished in order of the grain size of the abrasive grains from “rough” to “fine”. A method for polishing a cylindrical member, characterized by being provided by polishing along an axial core.
6. The cylindrical member polishing apparatus according to claim 5, wherein the abrasive grains mixed with the bristle material or the elastic body used in the polishing means have a grain size of F180 to # 2000, and the grain sizes thereof are substantially the same. A polishing method for a cylindrical member, characterized in that polishing means having a material or an elastic body is continuously provided along an axis of a cylindrical workpiece to be polished.
8. The cylindrical member polishing apparatus according to claim 7, wherein the abrasive grains mixed in the bristle material or the elastic body used in the polishing means have a grain size of F180 to # 2000, and the bristle grains having substantially the same grain size. A polishing method for a cylindrical member, characterized in that polishing means having a material or an elastic body is continuously provided along an axis of a cylindrical workpiece to be polished.