KR101600997B1 - Polishing device for columnar member, columnar member and polishing method therefor - Google Patents

Abstract

An object of the present invention is to provide a machining method for machining a workpiece made of a hard material into a cylindrical shape with a predetermined diameter and removing minute cracks existing in the surface layer portion of the workpiece and removing irregularities on the surface To thereby reduce the surface roughness, and a polishing method thereof.
The polishing apparatus includes a pinching unit connected to a rotating unit of a workpiece to hold the workpiece by sandwiching both end faces of the workpiece, polishing means for polishing the outer circumferential surface of the workpiece to rotate the tips thereof in contact with each other, A height position detecting means for detecting a height position of a workpiece to be polished and a workpiece to be polished before polishing, a height position detecting means for detecting a height position of the workpiece, Wherein the polishing means comprises a grinding wheel having a grinding stone and a polishing material having a base material containing abrasive grains or an elastic body and at least one of the abrasive brushes, And the grinding wheel and the grinding brush are arranged and arranged along the axis of a cylindrical workpiece.

Description

TECHNICAL FIELD [0001] The present invention relates to a polishing apparatus, a cylindrical member, and a cylindrical member for a cylindrical member,

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

Examples of the cylindrical member of the sheathing material to be polished of the present invention include a silicon block which is a material for obtaining a silicon wafer by slicing with a wire saw, Is formed in a cylindrical shape by cutting a silicon ingot made of a single crystal or a polycrystal by a band saw or a wire saw. However, when the accuracy required for the external dimensions after the cutting is high, The surface layer is ground.

A single crystal silicon block obtained by a Czochralski method (CZ method) or the like, or a polycrystalline silicon block obtained by a casting method or the like is sliced by a wire saw in the next step to produce a silicon wafer. Micro-cracks And small concaves and convexes are present, cracks and debris of the silicon wafer produced at the time of the slicing process are likely to occur. Therefore, in Patent Documents 1 and 2, the surface layer portion of the silicon block is removed by polishing (And micro-cracks) existing in the surface layer portion are removed to improve the yield of the product of the silicon wafer. Particularly, in Patent Document 1, surface layer portions of silicon blocks of 50 to 100 μm and 200 μm or less are removed from the surface by polishing to flatten the surface roughness (Ry) of 10 to 20 μm before polishing to 3 to 4 μm . Further, Patent Document 3 is disclosed as a polishing apparatus for a silicon block.

Japanese Patent Application Laid-Open No. 2005-347712 Japanese Patent Application Laid-Open No. 2002-252188 Japanese Patent Application Laid-Open No. 2009-233794

Patent Documents 1 to 3 all disclose a polishing method and a polishing apparatus for a surface layer portion of a silicon block of a quadrangular prism member and an apparatus for polishing a surface layer portion of a cylindrical member to be subjected to the present invention is disclosed It is not. In addition, there is a case where the diameters of the cross sections are different due to deviations in the manufacturing form of the cylindrical member or the cylindrical member in which the cross section does not form a true circle, and an apparatus for efficiently polishing these members is demanded.

The present invention provides a polishing apparatus capable of polishing an outer circumferential surface of a hard material such as a cylindrical silicon block, which is a workpiece, to be processed by a single apparatus while satisfying the above requirements, and a polishing method thereof.

A grinding means for grinding the outer circumferential surface of the workpiece; and a grinding means for grinding the workpiece to the grinding means, A height position detecting means for detecting a height position of a finished workpiece before polishing and a workpiece to be polished, a height position detecting means for detecting a height position of the workpiece, And a control means for calculating the surface roughness of the surface of the workpiece, and control means for calculating the surface roughness of the surface of the workpiece, wherein the polishing means comprises a grindstone , An elastic material containing abrasive grains or abrasive grains, or an elastic body containing abrasive grains, and further comprising an abrasive grains on the outer peripheral surface of the workpiece At least one or more abrasive brushes each having a tip contacted and rotated, and the abrasive brush and the abrasive brush are successively arranged along an axis of a cylindrical workpiece. (First invention)

In the cylindrical member polishing apparatus according to the first aspect of the invention, it is preferable that the polishing means includes a first grinding means of a grinding wheel and a grinding brush arranged in succession along the central axis of the cylindrical workpiece And a second grinding means of a grinding wheel and a grinding brush which are arranged to be arranged along the axis of the cylindrical workpiece,

Wherein each of the grinding wheel and the grinding brush of the first grinding means and the grinding wheel of the second grinding means forms a pair and each of the pair of grinding stones and the grinding brush is disposed in the same plane of the circular cross section of the workpiece Wherein the central axis of the first polishing means and the axis of the second polishing means are arranged to coincide with the radial direction of the workpiece and the center axis of the pair of the first polishing means and the center axis of the second polishing means Are arranged so as to intersect at the center of the cross section of the work so as to form a predetermined angle?. (Second invention)

In the polishing apparatus for a cylindrical member according to the first or second invention, the calculation in the control means may be a calculation of a difference in height position from two or more axial centers in the circumferential direction of the workpiece And an arithmetic operation for calculating a difference between a height position of the finished workpiece and a height position of the workpiece before polishing and an operation for setting different machining conditions from the input machining conditions. (Third invention)

In the polishing apparatus for a cylindrical member according to any one of the first to third aspects of the present invention, the abrasive brush is provided with a base material containing abrasive grains embedded in a ring shape at the bottom of the abrasive brush, . (Fourth invention)

In the polishing apparatus for a cylindrical member according to any one of the first to third aspects of the present invention, the polishing brush may comprise a base (e.g., a base, a base, and a base) of a tool for grinding a plurality of base materials (Base portions) are fixed on a polishing tool mounting plate. (Fifth invention)

In the polishing apparatus for a cylindrical member according to any one of the first to third aspects of the present invention, the polishing brush is a structure in which an elastic body containing abrasive grains is provided in a ring shape at the bottom of the abrasive brush means. (Sixth invention)

In the cylindrical member polishing apparatus according to any one of the first to third aspects of the present invention, the particle size of the abrasive forming the grindstone is F60 to # 800. (Seventh invention)

In the cylindrical member polishing apparatus according to any one of the first to third aspects of the present invention, the particle size of the abrasive grains mixed with the base material or the elastic body used in the abrasive means is F180 to # 2000, The polishing apparatus according to any one of claims 1 to 3, wherein at least two kinds of polishing means having a base material or an elastic body are selected and the polishing means having different grain sizes of the abrasive grains are polished in the order of " Shape along the axis of the workpiece. (Eighth invention)

In the polishing apparatus for a cylindrical member according to any one of the first to third aspects of the present invention, it is preferable that the particle size of the abrasive grains mixed with the base material or the elastic material used for the abrasive means is F180 to # 2000, A polishing means having a base material or an elastic body is provided continuously along the central axis of the cylindrical workpiece. (Ninth invention)

The present invention also provides a cylindrical member obtained by polishing a cylindrical member according to any one of the first to third aspects of the present invention, wherein micro cracks existing at a depth of 100 탆 or less from the surface layer of the member to be processed are removed, And the surface roughness (Ry) of the surface is 3 mu m or less. (Tenth invention)

The columnar member according to the tenth aspect is a silicon block or ceramics. (11th invention)

In the method of polishing a cylindrical member by the polishing apparatus for a cylindrical member according to any one of the first to third aspects of the present invention, the workpiece held by the pinching means is rotated by the rotating means, A dimension adjustment step of adjusting the dimension of the workpiece by bringing the tip of the grinding wheel into contact with and rotating the outer periphery of the workpiece and moving the grinding means relative to the workpiece; And a finishing step of polishing the workpiece by bringing the tip of the grinding brush into contact with the outer peripheral surface of the workpiece and rotating the grinding brush, and moving the grinding means relative to the workpiece. (Twelfth invention)

In the method of polishing a cylindrical member according to the twelfth invention, the abrasive grains to be mixed with the base material or the elastic material used in the abrasive brush may have a particle size of F180 to # 2000, Two or more kinds of abrasive grains having different grain sizes are polished in succession along the central axis of the cylindrical workpiece so as to grind the abrasive grains of different abrasive grain sizes in the order of "large one" to "small one" . (Thirteenth invention)

In the method of polishing a cylindrical member according to the twelfth invention, it is preferable that the abrasive grains mixed in the base material or the elastic body used in the abrasive brush have a particle size of F180 to # 2000 and the abrasive brush has abrasive The means is provided successively along the central axis of the cylindrical workpiece and polished. (Fourteenth invention)

Effects of the Invention

The grinding wheel and polishing brush provided in the grinding means are brought into contact with the outer circumferential surface of the cylindrical workpiece, and the workpiece is rotated by the rotating means, whereby the outer peripheral surface of the workpiece can be polished. Further, since the workpiece held by the pinching means is rotated in the circumferential direction by the rotating means (hereinafter referred to as rotating means (for a workpiece)), the outer circumferential surface of the workpiece is uniformly polished . First, the work piece is polished up to the vicinity of a target dimension by the above-mentioned grinding wheel, and then polishing is performed with an abrasive brush, whereby micro cracks existing in the surface layer portion of the outer circumferential surface can be removed (first and twelfth invention). Further, by disposing the first grinding means and the second grinding means along the central axis of the work piece, the grinding stone and the grinding brush shorten the machining time (the second invention). The size adjustment step can be efficiently performed by setting the particle size of the abrasive forming the abrasive to F60 to # 800 (JIS R6001: 1998) (seventh invention). The abrasive brush has a structure in which a base material containing abrasive grains is planted in a ring shape on the bottom of the abrasive brush, a structure in which a plurality of base portions of a polishing tool in which a plurality of abrasive materials containing abrasive grains are bundled, A structure in which an elastic body containing abrasive grains is provided in a ring shape on the bottom of the abrasive brush means can be appropriately selected (fourth, fifth, and sixth inventions). The abrasive grains can be appropriately selected from the range of F180 to # 2000 (JIS R6001: 1998) according to the purpose. When the abrasive brush having a plurality of abrasive brushes is used, the grain size of the abrasive grains In the order of "small" "fine" "to" small "to" small ", the particle size is changed from" large "to" small " It is possible to remove cracks and unevenness (the eighth and thirteenth inventions) and does not require a multi-stage processing such as the above-mentioned "large" "rough" -> "small" (For example, when the micro-cracks on the surface of the workpiece W are minute and the surface roughness does not greatly differ from the required value, the workpiece W is processed with only " small " , The above- Degrees, which grinding means is also possible to shorten the processing time by roughly the same (the invention of claim 9, claim 14). In the present specification, the abrasives and the abrasive grains have a "roughly the same grain size" as the abrasive grains and abrasive grains having the same grain size and the same grain size to obtain an equivalent abrasive effect.

The deviation of the pinching region from the central axis can be determined by holding the workpiece before machining, measuring the height position between the central axis and the outer peripheral surface of the workpiece at two or more positions, and calculating the difference. In addition, a height position at which polishing of a standard piece (hereinafter referred to as " master work ") of the finished product of polishing is started by polishing means is detected and stored by the height position detecting means before the start of polishing, The height position is detected and the difference between the height position detected by the master work and the height position detected by the workpiece is calculated and the distance between the tip of the polishing means and the workpiece is corrected based on the calculation result , And a plurality of workpieces can be continuously polished. Further, by performing an operation for setting other machining conditions from the input machining conditions, it is possible to perform machining with a simple input. The calculation by the control means is performed at least one of them. The "input" described in the first invention means information input (memorized) to the control means by the manual (operator), information input (memorized) automatically to the control means, manual and / or automatic input Or information input (stored) after calculation based on the information that has been input (stored). (Third invention)

Further, by using the above-described polishing apparatus, it is possible to obtain a cylindrical member in which micro-cracks of 100 mu m are removed from the surface layer and the surface roughness Ry is 3 mu m or less. As the cylindrical member, a hardening material such as a silicon block or ceramics can be suitably used. (Tenth and eleventh inventions)

1 is an explanatory diagram showing the entire polishing apparatus of the present invention.
2 is an explanatory view showing an example of an abrasive brush of the present invention. 2 (A) is a partially cutaway sectional view seen from the front, and Fig. 2 (B) is an AA line arrow in Fig. 2 (A).
3 is an explanatory view showing another example of the polishing brush of the present invention. Fig. 3 (A) is a schematic view of a base material planted on the bottom part, and Fig. 3 (B) is a schematic view of an elastic material provided on the bottom part.
Fig. 4 is an explanatory view showing a processing step of the present invention. Fig. Fig. 4 (A) is an explanatory view showing a position adjustment step, and Fig. 4 (B) is an explanatory view showing a finishing step.
5 is an explanatory view showing a third embodiment of the present invention. Fig. 5 (A) 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, Fig. 5 (B) And the second 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 and two polishing brushes having different polishing roughnesses are connected successively. The up-and-down and left-right directions in the following description refer to the up, down, left, and right directions in the drawings unless otherwise specified.

A schematic diagram of a polishing apparatus for a cylindrical member is shown in Fig. A cylindrical member polishing apparatus 1 according to the present embodiment includes a base 11 for placing a workpiece W thereon, a lifting means 12 for moving the base 11 up and down, A pinching means 13 for holding the workpiece W sandwiched therebetween, rotation means (for a workpiece) (not shown) connected to the pinching means for rotating the workpiece W about the axis of the workpiece W, A moving means (14) for moving the workpiece (W) held in contact with the workpiece (W) in the left and right directions in the figure and moving the workpiece (W) The height position detecting means 15 of the outer circumferential surface of the workpiece W, the polishing means 20 and the control means (not shown) The polishing means 20 is constituted by a grinding wheel 21 connected to a rotating means (for grinding wheel) 21M and an abrasive brush 22 to which a rotating means (for grinding brush) 22M is connected.

Prior to the processing of the workpiece W, a height position (reference position) from the central axis to the outer circumferential surface of the master work is measured by the height position detection means 15 in order to calculate the processing amount of the workpiece W , And stored in control means (not shown). First, both ends of the master work are sandwiched and held by the pinching means 13. When the master work is sandwiched by the pinching means 13, it is placed on a base 11 having a V-shaped groove, for example. By placing the master work in the groove, the center in the left-right direction (the vertical direction in the drawing in Fig. 1) centering on the axis of the master work can always be substantially the same position. In addition, the elevation means 12 can finely adjust the mounting position in the vertical direction in the figure. The master work is placed on the base and the pinching axes 13a and 13b of the pinching means 13 are advanced respectively so that the pinching portions 13c and 13d sandwich the both ends of the master work. Thereafter, the base 11 is separated from the master work by lowering the base 11 by the lifting means 12.

Since the pinching means 13 is rotated by the rotating means (for a workpiece), that is, about the axis centers of the pinning axes 13a and 13b, the center axis of the pinning axes 13a and 13b, (Centering) adjustment should be made so that they match. After the master work is sandwiched between the pinching means 13 and the height position detecting means 15 measures the height position H1 of the outer circumference of the master work and then the master work is rotated (for example, 180 degrees) , And the height position (H2) in the rotated state is measured. Further, in the present embodiment, three height position detecting means 15 are arranged in the longitudinal direction of the master work (left and right direction in the drawing), and the height position is measured at each position. The difference between the measured H1 and H2 is calculated and if the 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 pinning axes 13a and 13b ), Respectively, to release the pinching of the master work. The upper and lower positions of the base, that is, the upper and lower positions of the master work are adjusted by raising or lowering the elevation means 12 based on the calculation result, and then the master work is held by the pinching means 13 again. After separating the base 11 from the master work, H1 and H2 of the master work are similarly measured, and the centering process of the master work in which H1 and H2 are substantially equal is completed. Further, the height position H at this time is stored in the control means as the reference position. Thereafter, the base 11 is raised, the master work is placed on the base 11, the pinning axes 13a and 13a are retracted to cancel the pinching of the master work, 11), the measurement process of the reference position is completed.

Next, after the workpiece W is placed on the base 11, the workpiece W is retained by the pinching means 13 in the same manner as described above, and then the workpiece W is held by the height position detecting means 15, The height position h1 of the workpiece W 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 in accordance with the shape of the surface of the workpiece W and the like. That is, when the rotation angle is 180 degrees, the height positions h1 and h2 of two points with respect to the circumferential direction of the work W and the height positions h1, h2, and h3 of three points when the rotation angle is 120 degrees, When the rotation angle is 90 degrees, the height positions (h1, h2, h3, h4) of four points can be measured. In the present embodiment, h1 (h1a, h1b, h1c) and h2 (h2a, h2b, h2c) are calculated by using three height position detecting means 15 (15a, 15b, 15c) , h3 (h3a, h3b, h3c), and h4 (h4a, h4b, h4c). The base 11 is raised so that the difference between the height positions h1, h2, h3 and h4 is minimized and the workpiece W is placed on the base 11 similarly to the centering adjustment of the master work described above The pinching of the workpiece W is released and the upper and lower positions of the base 11, that is, the upper and lower positions of the workpiece W are adjusted by raising or lowering the base 11, H2, h3, and h4 of the workpiece W are measured again after the base 11 is separated from the workpiece W by holding the workpiece W with the pinching means 13 and separating the base 11 from the workpiece W. All of the height positions h1, h2, h3, and h4 of the workpiece W after adjustment need to be larger than the reference position H. [ Since the workpiece W rotates about the axis of the workpiece W when polishing is performed, the height positions h1, h2, h3, and h4 may be the same or different from each other, Must be within a range that does not affect the rotation, and is calculated and determined by the control means.

The workpiece W passed in the above determination is polished by the grinding wheel 21. The grinding wheel 21 is set so that the height positions h1, h2, h3 and h4 of the workpiece W become close to the reference position H in consideration of the polishing amount by the polishing brush in the next step h) is used for polishing the workpiece W. The particle size of the abrasive constituting the grinding wheel 21 is preferably in the range of F60 to # 800, preferably in the range of # 100 to # 500 (the definition of the particle size of the abrasive is JIS standard R6001: 1998 (Hereinafter referred to as " a ").

(The rotation speed of the grinding wheel 21, the rotation speed of the polishing brush 22, the rotation speed of the workpiece W, the feed speed of the workpiece W, the machining allowance by the abrasive brush, the machining allowance (the amount of cuff off of the tip of the polishing brush relative to the machined surface S of the workpiece, hereinafter simply referred to as the "cutting amount"), The grinding wheel 21 is moved downward, that is, the grinding wheel 21 is moved in the direction of the machining plane S. Thereafter, the grinding wheel 21 The grinding wheel 21 is rotated around the central axis of the grinding surface of the grinding wheel 21 by driving the rotating means (grinding wheel) 21M (in this embodiment, the motor) (A motor in the present embodiment) connected to the pinching means 13 to rotate the workpiece W about its axis, The key is simultaneously moved from the left side to the right side in the figure by the moving means 14 so that the abrasive face of the grinding wheel 21 contacts the machined surface S of the workpiece W, The grinding by the grinding wheel 21 is performed (see FIG. 4 (A)). Further, when the difference between the reference position H and the height positions h1, h2, h3 and h4 is large, The grinding wheel 21 may be lowered step by step every time the moving means is reciprocated or the moving means is reciprocated. The grinding wheel 21M is moved to the position before grinding and the driving of the grinding wheel 21M is stopped. After that, the workpiece W is moved to the position before the start of polishing .

Next, the workpiece W is polished by the polishing brush 22 (polishing brushes 22a and 22b). As the polishing brush 22, the one shown in Fig. 2 was used in the present embodiment. The base material 24a of synthetic resin such as nylon mixed with abrasive grains is bundled and one end of the base material 24a is fixed in the abrasive tool holder 24b to form the abrasive tool 24, Is detachably attached to a polishing tool attachment plate 23 which is connected to a rotating means (polishing tool) 22M so as to rotate horizontally and whose lower end contacts the machining surface S of the workpiece W to perform polishing The polishing tool 24 can be separated from the polishing tool attaching plate 23 and replaced with a new polishing tool 24 when the polishing tool 24 is worn.

The grain size of the abrasive grains to be mixed with the base material is preferably selected from the range of the grain size of the abrasive and from the range of F180 to # 2000 (definition of abrasive grain size conforms to JIS standard R6001: 1998).

In this embodiment, the grinding wheel 21 and the two polishing brushes 22a and 22b are disposed along the axis of the workpiece W. The abrasive brushes 22a and 22b are made of different abrasive grains and the abrasive brushes 22a and 22b have small sizes. Are arranged in the order from left to right in Fig. The abrasive brush 22a having a large particle size has scratches and irregularities on the surface (work surface S) of the workpiece W due to polishing by the grinding wheel 21, Most of the existing micro cracks can be removed (rough finishing), and the polishing brush 22b having a small particle size can remove micro cracks present in the surface layer portion of the workpiece W (finishing ).

The polishing process is performed on the basis of the machining conditions input to the control means in advance and the reference position H and the height position h and the polishing brush 22 is moved up and down, (S). Thereafter, the polishing brush 22 is rotated around the central axis of the polishing surface by driving the rotating means (for the polishing brush) 22M (the motor in this embodiment) connected to the polishing brush 22, respectively. Each of the polishing surfaces of the polishing brush 22 is brought into contact with the processing surface S of the workpiece W by moving the workpiece W from the left side to the right side in the figure by the moving means 14 , And the polishing with the polishing brush 22 is performed based on the above-mentioned processing conditions. Since the workpiece W is moved from the left side to the right side in the drawing and polishing is performed as described above, polishing can be performed in the order of rough finishing and finishing (see FIG. 4 (B)). . After the completion of polishing of the polishing brush 22, the polishing brush 22 is moved (raised) to the position before the start of polishing and the driving of the rotating means (for the polishing brush) 22M is stopped. Thereafter, the workpiece W is moved to the position before the start of polishing, the driving of the rotating means (for the workpiece) is stopped, and the rotation of the workpiece W is stopped.

Thereafter, the pinching axes 13a and 13b are retracted as described above, after the base 11 is raised and the workpiece W is placed thereon. As a result, the pinching of the workpiece W by the pinching means 13 And a series of polishing is completed by removing the workpiece W.

When a plurality of workpieces W are to be machined, the workpiece W is newly placed on the base 11, and then the grinding process is performed through the same process (paragraph <0031> to paragraph <0038>). That is, the height position of the master workpiece is measured for the first time, and the height position is set as the reference position, after which a plurality of workpieces W can be polished.

The grinding wheel 21 and the grinding brushes 22a and 22b may be moved and the grinding wheel 21 and the grinding brushes 22a and 22b may be moved in the left and right directions, Both of the workpiece W may be moved.

In the present embodiment, although the machining conditions are manually inputted to the control means, the machining conditions that have not been inputted from the manually entered machining conditions and the positions of the outer circumferential surface of the workpiece W automatically input (stored) And the polishing process may be performed.

For example, the moving speed of the workpiece W may be calculated by the control means by inputting the cutting amount and the rotational speed of the polishing means 2, or the cutting means may be calculated by the control means from other machining conditions or height positions. Then, polishing processing can be performed based on the results of these calculations.

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

The polishing brush 22 as the polishing means 20 is not limited to the one shown in Fig. 2, but a polishing tool 25 made of a base material 25a mixed with abrasive grains may be directly attached to the abrasive tool attachment plate 23 And the abrasive tool attachment plate 23 may be exchanged with each other when the abrasive tool 25 is worn or may be replaced with a base material body made of synthetic resin such as nylon containing abrasive grains (See FIG. 3 (A), the upper drawing is a front view, and the lower drawing is a bottom view (AA line arrows in the front view) of the polishing apparatus 20 ). The polishing means 20 and the workpiece W may also be used in a case where the polishing means 20 is brought into contact with the edge portion of the columnar body forming an angle of about 90 degrees at the time of polishing or processing such as ceramics, An elastic body 24d made of synthetic resin containing abrasive grains may be provided on the bottom of the polishing means 20 in a ring shape 3 (B). The above drawing shows a front view, and the lower drawing shows a bottom view (AA line arrow in the front view). The elastic body 24d in this case refers to, for example, a bulk body of a resin having a comparatively soft hardness or a bulk body of a resin including polyurethane or urethane having a large number of bubbles therein or an elastic body of fiber- It may be silver. In a bulk body of a resin having a relatively soft hardness, the resin itself acts as a buffer material. In a bulk body of a resin having bubbles, the inner bubbles act as a buffer material. In the elastic body including the abrasive grains, the elastic body is entangled with each other, so that air is contained in the inside of the aggregate, so that this air layer acts as a buffer material. In any case, the type of synthetic resin, the content of abrasive grains, and the like are appropriately selected so as to maintain an appropriate elastic force when the elastic body 24d contacts the workpiece. The grain size of the abrasive grains to be mixed with the base material 24c and the elastic body 24d is preferably selected from the range of F180 to # 2000 as in the present embodiment.

The particle size of the abrasive grains contained in the abrasive brush 22 to be subjected to the rough finishing process such as the case where the scratches and irregularities are large or the micro cracks are deep is smaller than the particle size of the abrasive grains included in the abrasive brush 22 for finishing It is also possible to dispose at least one abrasive brush (intermediate finishing) having an intermediate particle size between the abrasive brushes 22a and 22b. That is, three or more polishing brushes may be arranged along the axis of the workpiece W.

In the case where it is not necessary to perform coarse finishing such as a case where the blemish or unevenness is small or a micro crack is shallow, only the polishing brush 22b for finishing may be arranged.

When it is necessary to increase the amount of grinding performed by the grinding wheel 21 (machining amount) or when rough grinding with the grinding brush 22 can be performed by the grinding wheel 21, a plurality of grinding wheels 21 are arranged .

The results of the evaluation test using the apparatus of the first embodiment will be described below.

First, by using the apparatus of the first embodiment, a cylindrical single-crystal silicon block as a workpiece W is processed into a dimension of? 175 mm x 500 mm, and micro-cracks existing in the surface layer portion of the work W And the surface roughness of the surface was removed to reduce the surface roughness.

Thereafter, evaluation was made as to whether or not the rate of generation of defective products due to cracking, fragmentation (debris), etc. of the silicon wafer when the silicon wafer was formed by slicing the silicon block into wire pieces was evaluated.

Microcracks having a depth of 80 to 100 占 퐉 are present in the surface layer portion of the workpiece W before polishing, and the surface roughness thereof is (Ry) 9 to 11 占 퐉 (the definition of Ry is according to JIS B0601: 1994) The generation rate of defective products due to cracks, debris or the like was 5 to 6% when the silicon block which had not been polished was cut into a silicon wafer by slicing (slicing) the silicon block.

Next, the silicon block as the workpiece (W) is polished by using the polishing apparatus according to the first embodiment to remove micro cracks and irregularities and to reduce the surface roughness. Thereafter, And the generation rate of defective products due to cracks, debris or the like when the silicon wafer was processed by processing was evaluated.

The processing conditions in this evaluation test were set as shown in Table 1, entered into the control means, and three single crystal silicon blocks were processed. The results are shown in Table 2. Thus, by machining using the polishing apparatus according to the first embodiment, the diameter of the single crystal silicon block is processed to a target dimension, and the maximum depth of micro cracks is 0.7 to 0.9 占 퐉 and the surface roughness is flat And a Ry of 0.7 to 1.0 占 퐉 (average: Ry of 0.9 占 퐉), so that microcracks and surface roughness could be reduced. Further, in Table 2, the data described in the column "after grinding by a grinding wheel" shows data in the state "before grinding by a grinding wheel and before grinding by a grinding brush" The data at the middle step of the process is shown. The generation rate of defective products due to cracks, debris or the like was 3 to 4% when the silicon block was processed into a silicon wafer by slicing all three of the silicon blocks. The maximum depth of microcracks is preferably 3.0 m or less, and preferably 2.3 m or less. When the maximum depth is 3.0 mu m or more, the incidence of defective products increases. When the maximum depth is 2.3 탆 or less, the effect on the generation rate of defective products due to cracks, debris or the like when the silicon wafer is sliced by a thickness of several tens of 탆 is small. In this evaluation test, the maximum depth was 0.9 占 퐉 and it was possible to significantly reduce 2.3 占 퐉, which affects the generation rate of the defective product.

Next, the polishing apparatus according to the second embodiment will be described. The polishing apparatus according to the second embodiment has an apparatus configuration for use in a case where a multi-step machining such as finishing machining after coarse finishing is not required and surface conditions required by one-step machining are obtained. Here, only differences from the first embodiment will be described.

For example, when microcracks on the surface of the workpiece W before the polishing process are very small and there is no large difference in the surface roughness before the polishing process with respect to the required value, the particle size of the abrasive grains included in the polishing brushes 22a and 22b Can be made substantially the same as the polishing brush 22b used for finishing. By arranging a plurality of abrasive brushes having substantially the same abrasive grains included in the abrasive brush 22, the machining time can be shortened.

Next, a polishing apparatus according to a third embodiment will be described with reference to Fig. In the polishing apparatus according to the third embodiment, 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 plane of the same section (circular shape) of the workpiece W. The central axes of the first and second polishing means 30 and 40 are arranged so as to coincide with the radial direction of the workpiece W. The first and second polishing means 30, The central axis of the first polishing means 20 and the central axis of the second polishing means 20 constitute a predetermined angle? So that the workpiece W does not interfere with the workpiece W, As shown in Fig. (See Fig. 5 (A)) This angle? 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 &amp;thetas; may be set to 180 DEG, and the axis of the first polishing means 30 and the axis of the second polishing means 40 may be perfectly aligned to face each other. With this configuration, the workpiece W is polished while being rotated in the circumferential direction, so that the machined surface of the workpiece is polished at two places of the first polishing means 30 and the second polishing means 40, Because it is. Processing time is shortened.

Also in the polishing apparatus according to the third embodiment, as shown in Fig. 5B (in the above drawing, the angle is defined as 180 deg.) As in the polishing apparatus according to the first embodiment, Any number of grinding wheels 31 and 41 and polishing brushes 32 and 42 included in the first polishing means 30 and the second polishing means 40 can be arranged. That is, the grinding wheels 31 and 41 and the abrasive brush may be provided one by one or a plurality of grinding blades may be arranged along the axis of the work W. For example, the drawing shows a state in which two grinding wheels 32 and 42 and two grinding brushes 32 and 42 and 32a and 32b and 42a and 42b are arranged, respectively. In this case, a grindstone (first grinding means) 31 and a grindstone (second grinding means) 41 are provided on the first row in this order from the left along the axis of the work W, A brush A (first polishing means) 32a, a polishing brush A (second polishing means) 42a, a polishing brush B (first polishing means) 32b on the third row, And a polishing brush B (second polishing means) 42b are arranged. At this time, the particle size of the abrasive forming the grindstone and the particle size of the abrasive grains contained in the base material or the elastic body provided in each of the abrasive brushes are controlled by the grinding wheel 31 (first polishing means) (First polishing means) 32a, a polishing brush A (second polishing means) 42a, a polishing brush B (first polishing means) 32b And the polishing brush B (second polishing means) 42b are substantially the same, that is, the grinding wheel of the same row and the polishing brush have substantially the same polishing force. Further, similarly to the second embodiment, when machining can be performed by a polishing means having one polishing force, particle sizes of the abrasive contained in the base material or the elastic body provided in all the polishing brushes can be made substantially equal.

In the polishing apparatus according to the third embodiment described above, the two polishing means 20 including the first polishing means 20 and the second polishing means 20 are arranged in the circumferential direction of the workpiece W However, the present invention is not limited to this. Any number of polishing means may be arranged in accordance with the arrangement space, the target machining time, and so on, as long as the respective polishing means do not interfere with each other.

The present invention is not limited to the machining of the cylindrical silicon block, but can be suitably used for the overall hard material such as ceramics.

1 Polishing equipment
11 Expectations
12 elevating means
13 pinching means
13a and 13b pin pins
13c and 13d,
14 Moving means
15, 15a, 15b, 15c height position detection means
20 polishing means
21 stone
21M Rotating means (for grinding wheel)
22, 22a, 22b polishing brush
22M rotating means (for polishing brush)
30 First polishing means
31 grindstone (first grinding means)
31M rotating means (for a grinding wheel (first polishing means)
32, 32a, 32b An abrasive brush (first abrasion means)
40 second polishing means
41 grindstone (second grinding means)
41M rotating means (for grinding stone (second polishing means))
42, 42a, 42b The second polishing means
W workpiece
S machined surface

Claims (14)

A pinching unit connected to the rotating means of the workpiece and holding the both ends of the workpiece by interposition,
A polishing means for polishing the outer circumferential surface of the workpiece;
Moving means for relatively moving the workpiece relative to the polishing means in a longitudinal direction orthogonal to a substantially circular sectional direction of the workpiece;
A height position detecting means for detecting a height position of the finished workpiece and the workpiece before polishing,
A control means for inputting the height position and the machining conditions,
And an outer circumferential surface of the cylindrical work piece,
The grinding means includes a grinding stone and a base material containing abrasive grains, the tip of the abrasive grains contacting the outer peripheral surface of the workpiece, , And furthermore, as a polishing brush which has a distal end contacting and rotating on the outer circumferential surface of the workpiece to remove micro cracks existing in a surface area of 100 mu m or less from the surface layer of the workpiece and making the surface roughness Ry of the polishing surface 3 mu m or less A polishing brush having a particle size of F60 to # 800 and a particle size of abrasive to be mixed with the base material used in the abrasive brush is F180 to # 2000 and having a different particle size, The abrasive brushes having different particle sizes of the abrasive grains are selected from two or more types so that the abrasive brushes are polished in the order of "rough" to " Is arranged to be installed one after another along the shaft center (軸 芯) of the processing member in a circle shape,
Wherein the calculation by the control means includes a calculation of a difference in height position from two or more axial positions in the circumferential direction of the workpiece and a calculation of a difference between a height position of the finished workpiece and a height position of the workpiece before polishing Lt; RTI ID = 0.0 &gt; 1, &lt; / RTI &gt;
Wherein the polishing brush has a structure in which a plurality of base portions of a polishing tool in which a plurality of base materials containing abrasive grains are bundled are fixed on an abrasive tool mounting plate. The method according to claim 1,
Wherein the grinding means comprises a first grinding means of a grinding wheel and a grinding brush successively arranged along the central axis of a cylindrical workpiece and a second grinding means of a grinding wheel and grinding means arranged successively along the central axis of the cylindrical workpiece, And a second polishing means of a brush,
Wherein each of the grinding wheel and the grinding brush of the first grinding means and the grinding wheel of the second grinding means forms a pair and each of the pair of grinding stones and the grinding brush is disposed in the same plane of the circular cross section of the workpiece Wherein the central axis of the first polishing means and the axis of the second polishing means are arranged to coincide with the radial direction of the workpiece and the center axis of the pair of the first polishing means and the center axis of the second polishing means Wherein the central axis of the polishing means of the cylindrical member is arranged so as to intersect the center of the cross section of the work so as to form a predetermined angle? The method according to claim 1,
Wherein the calculation by the control means includes an operation for setting a different machining condition from the input machining condition. delete delete A method of polishing a cylindrical member by a polishing apparatus for a cylindrical member according to any one of claims 1 to 3 is characterized in that the workpiece held by the pinching means is rotated by the rotating means,
A dimension that adjusts the dimension of the workpiece by contacting and rotating the tip of the grinding wheel with the outer circumferential surface of the workpiece and moving the tip of the grinding wheel relative to the workpiece up to the vicinity of the target dimension, An adjusting step,
Wherein the grinding means is moved relative to the workpiece so that the tip of the grinding brush is brought into contact with the outer circumferential surface of the workpiece, And a surface roughness (Ry) of the abrasive surface to be removed is 3 m or less, wherein the particle size of the abrasive forming the abrasive is F60 to # 800, and the abrasive brush The abrasive brush having different abrasive grains of the abrasive grains using the abrasive brushes having the abrasive grains mixed with the base material having a size of F180 to # "To" small """&quot;
The dimensional adjustment step includes a height position detection step of detecting the height position of the abrasive machined finished product and the workpiece before polishing,
And a control step of inputting the height position and the machining conditions,
Wherein the calculation in the control step includes a calculation of a difference in height position from two or more central axes in the circumferential direction of the workpiece and a calculation of a difference between a height position of the finished workpiece and a height position of the workpiece before polishing Of the polishing surface of the cylindrical member. delete delete delete delete delete delete delete delete

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