JP2015178149A - Grinding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grinding device capable of reducing the amount of wear and tear of a grinding stone caused by the dressing when a grinding wheel is mounted again.SOLUTION: The grinding device includes: a chuck table; and grinding means. The grinding means has: a spindle 22; a wheel mount 23; and a grinding wheel 24. A first mark M1 is formed on an outer peripheral side surface 23a of the wheel mount 23, and there is formed a second mark M2 to be aligned with the first mark M1 when the grinding wheel 24 is fixed to the wheel mount 23, on an outer peripheral surface 241c of an annular base 241 of the grinding wheel 24. Multiple female threads N1a-N1h, N2a-N2h are formed at irregular intervals in a circumferential direction at an undersurface 23c of the wheel mount 23 and an attachment part 241a of the grinding wheel 24 respectively, so that fastening screws S for fixing the grinding wheel 24 to the wheel mount 23 are screwed with the female threads only when the first mark M1 and the second mark M2 are located at predetermined positions.

Description

  The present invention relates to a grinding apparatus.

  When flattening the surfaces of various workpieces, grinding using a grindstone (grinding grindstone) is performed. For example, when the back surface of a semiconductor wafer having a device formed on the front surface is ground to be finished to a desired thickness, a grinding apparatus provided with a grinding means is used.

  The grinding means is configured by fastening an annular base of a grinding wheel with a screw to a wheel mount fixed to the tip of a spindle (see, for example, Patent Documents 1 and 2). The grinding wheel makes the grinding wheel parallel to the holding surface of the chuck table, and grinds the dressing board that is adsorbed and fixed to the chuck table so that a flat semiconductor wafer can be ground.

  In such a grinding apparatus, the grinding wheel is appropriately replaced depending on the type of grinding wheel and the type of semiconductor wafer to be ground. In such a grinding apparatus, the used grinding wheel is often mounted again.

JP 2003-89065 A JP 2006-55963 A

  However, when the used grinding wheel is mounted again, the grinding wheel is formed in parallel to the holding surface of the chuck table, so dressing is performed. Therefore, there is a demand to reduce the amount of consumption by dressing as much as possible.

  The present invention has been made in view of the above, and an object of the present invention is to provide a grinding apparatus capable of reducing the amount of consumption of a grinding wheel by dressing when a grinding wheel is mounted again.

  In order to solve the above-described problems and achieve the object, the present invention includes a chuck table for holding a plate-like workpiece on a holding surface, and a grinding means for grinding the workpiece held on the chuck table; The grinding means includes: a spindle rotatably accommodated in the spindle housing; a wheel mount fixed to the spindle tip exposed from the spindle housing; and a mounting portion attached to the wheel mount. And a grinding wheel provided with an annular grinding wheel disposed at a free end of the annular base, and the outer peripheral side surface of the wheel mount or the upper surface of the wheel mount has a first A mark is formed on the outer peripheral surface of the annular base of the grinding wheel to align with the first mark when the grinding wheel is fixed to the wheel mount. The bottom surface of the wheel mount and the mounting of the grinding wheel so that the fastening screw for fixing the grinding wheel is screwed to the wheel mount only when the first mark and the second mark are positioned at predetermined positions. The plurality of female screws formed in the portion are formed at unequal intervals in the circumferential direction or at unequal distances from the rotation center.

  In the above grinding apparatus, it is preferable that the weight of the annular base is adjusted so that the grinding wheel is rotationally balanced when the grinding wheel is fastened to the spindle using a female screw and rotated.

  According to the present invention, when the first mark and the second mark are positioned at a predetermined position, the fastening screw can be screwed into the wheel mount, so that the grinding wheel is fixed to the wheel mount at the predetermined position. be able to. In other words, according to the present invention, the grinding wheel can be fixed at a predetermined position with respect to the wheel mount. Therefore, even if the grinding wheel is remounted on the wheel mount, the grinding wheel is held against the holding surface of the chuck table. Parallel. Therefore, according to the present invention, there is an effect that it is possible to reduce the amount of consumption of the grinding wheel by dressing when the grinding wheel is mounted again.

FIG. 1 is a perspective view illustrating a schematic configuration example of a grinding apparatus according to an embodiment. FIG. 2 is a diagram illustrating a configuration example of a wheel mount and a grinding wheel of the grinding apparatus according to the embodiment.

  DESCRIPTION OF EMBODIMENTS Embodiments (embodiments) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited by the contents described in the following embodiments. The constituent elements described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the structures described below can be combined as appropriate. Various omissions, substitutions, or changes in the configuration can be made without departing from the scope of the present invention.

Embodiment
FIG. 1 is a perspective view illustrating a schematic configuration example of a grinding apparatus according to an embodiment. FIG. 2 is a diagram illustrating a configuration example of a wheel mount and a grinding wheel of the grinding apparatus according to the embodiment. The grinding apparatus 1 according to the embodiment shown in FIG. 1 is a processing apparatus that flattens the surface of the workpiece W. As shown in FIG. 1, the grinding apparatus 1 includes a chuck table 10, a grinding means 20, a reciprocating feed means 30, and a grinding feed means 40. Here, although the workpiece W is not specifically limited, For example, it is various processing materials, such as a semiconductor wafer in which a device was formed in one surface, an optical device wafer, an inorganic material substrate, and a ductile resin material substrate. In the present embodiment, the workpiece W is formed in a flat circular plate shape (disk shape).

  The chuck table 10 holds a plate-shaped workpiece W with a holding surface 10a. The chuck table 10 is formed in a disk shape that is substantially flat with respect to a horizontal plane. The chuck table 10 is rotatably supported by a reciprocating feed movement base 31 described later, and is rotated by a drive source such as a motor (not shown). The holding surface 10a forms the upper surface of the chuck table 10 in the vertical direction, and is formed substantially flat. The holding surface 10a is made of, for example, porous ceramic or the like, and sucks and holds the workpiece W or a dressing board (not shown) by a negative pressure of a vacuum suction source (not shown). Although it does not specifically limit as a dressing board, For example, abrasives, such as a diamond abrasive grain and CBN (cubic boron nitride) abrasive grain, are disperse | distributed to binders, such as a resin bond and a vitrify bond, and it is the same as the workpiece W Those formed in a disk shape are used.

  The grinding means 20 grinds the workpiece W held on the chuck table 10. The grinding means 20 includes a spindle housing 21, a spindle 22, a wheel mount 23, a grinding wheel 24, and a driving means 25.

  The spindle housing 21 is formed in a cylindrical shape extending in the vertical direction, and rotatably supports the spindle 22 inserted therein. The spindle housing 21 is supported on the grinding feed moving base 45 by a support portion 46 described later of the grinding feed means 40.

  The spindle 22 is rotatably accommodated in the spindle housing 21. The spindle 22 is rotationally driven by the driving means 25.

  As shown in FIG. 2, the wheel mount 23 is fixed to a spindle front end portion 22 a exposed from below the spindle housing 21 in the vertical direction. The wheel mount 23 is detachably fixed to the spindle tip 22a, for example, with a bolt or the like. The wheel mount 23 is formed in a disk shape parallel to the horizontal plane. The upper surface 23b and the lower surface 23c of the wheel mount 23 are formed to be parallel and flat with respect to the horizontal plane. The wheel mount 23 is driven to rotate in a horizontal plane by the spindle 22. The wheel mount 23 has a first mark M1. When the grinding wheel 24 is fixed to the wheel mount 23, the first mark M1 is preferably formed at a location that is easy for a worker to visually recognize. In this embodiment, the 1st mark M1 is formed in the outer peripheral side surface 23a of the wheel mount 23 as a location where an operator is easy to visually recognize. That is, the first mark M <b> 1 is formed on the outer peripheral side surface 23 a of the wheel mount 23. The first mark M1 is formed by a so-called laser marking process using a laser, for example. The first mark M1 is not particularly limited. For example, the first mark M1 has a triangular shape whose apex is positioned below the vertical direction when viewed in the horizontal direction.

  The wheel mount 23 includes a plurality of female screws N1a to N1h that penetrate the upper surface 23b and the lower surface 23c in parallel to the vertical direction. That is, a plurality of female screws N1a to N1h are formed on the lower surface 23c of the wheel mount 23.

  The plurality of female screws N1a to N1h are through holes through which the shaft portion Sa of the fastening screw S is inserted. The plurality of female screws N1a to N1h have the same hole diameter, which is larger than the shaft portion Sa of the fastening screw S and smaller than the head portion Sb of the fastening screw S. The plurality of female screws N1a to N1h are formed on the same distance from the rotation center, that is, on one circumference centered on the rotation center, and are formed at intervals in the circumferential direction of the wheel mount 23. In the present embodiment, in the circumferential direction, the interval between adjacent female screws N1a and N1b is smaller than the interval between adjacent female screws N1b and N1c, and the interval between adjacent female screws N1a and N1h is adjacent. The spacing is wider than the spacing between the mating female screws N1b and N1c. That is, in the present embodiment, the female screw N1a closest to the first mark M1 is formed to be shifted toward the female screw N1b. On the other hand, in the circumferential direction, the interval between adjacent female screws N1b, N1c, the interval between adjacent female screws N1c, N1d, the interval between adjacent female screws N1d, N1e, the interval between adjacent female screws N1e, N1f, The interval between adjacent female screws N1f and N1g and the interval between adjacent female screws N1g and N1h are the same interval (equal interval). That is, in the circumferential direction, the interval between the adjacent female screws N1a and N1b and the interval between the adjacent female screws N1a and N1h are unequal to each other, and the interval between the other adjacent female screws N1b to N1h. Even unequal intervals. That is, the plurality of female screws N1a to N1h are formed at unequal intervals in the circumferential direction. Note that the plurality of female screws N1a to N1h are formed at unequal intervals in the circumferential direction, among the plurality of angles formed by the plurality of female screws N1a to N1h adjacent to the circumferential direction and the rotation center. At least two angles are different.

  The grinding wheel 24 is detachably attached to the wheel mount 23 by a fastening screw S. The grinding wheel 24 is coaxially overlapped with the wheel mount 23 when viewed in the vertical direction. The grinding wheel 24 includes an annular base 241 and a grinding wheel 242.

  The annular base 241 has a mounting portion 241 a that is mounted on the wheel mount 23. The mounting portion 241a forms the upper surface of the annular base 241 in the vertical direction. The mounting portion 241a faces the lower surface 23c of the wheel mount 23 and is formed substantially flat with respect to the lower surface 23c. The mounting portion 241a is formed in an annular shape having an opening at the center when viewed in the vertical direction. The size of the outer diameter of the mounting portion 241 a is a size corresponding to the size of the outer diameter of the wheel mount 23. The size of the inner diameter of the mounting portion 241a is smaller than the distance from the rotation center of the plurality of female screws N1a to N1h of the wheel mount 23. That is, the mounting portion 241a is formed in an annular shape having a width that overlaps with the plurality of female screws N1a to N1h of the wheel mount 23 when mounted on the wheel mount 23 when viewed in the vertical direction. The mounting portion 241a has a plurality of female screws N2a to N2h.

  The plurality of female screws N2a to N2h are screw holes in which grooves that fit into the fastening screws S are cut. The plurality of female screws N2a to N2h are formed at intervals in the circumferential direction of the mounting portion 241a of the grinding wheel 24. The plurality of female screws N2a to N2h are formed at positions corresponding to the plurality of female screws N1a to N1h of the wheel mount 23. That is, when the grinding wheel 24 is coaxially fixed to the wheel mount 23, the plurality of female screws N2a to N2h are formed at positions that overlap with and communicate with the plurality of female screws N1a to N1h when viewed in the vertical direction. For this reason, in this embodiment, the female screw N2a immediately adjacent to the second mark M2 is formed to be shifted toward the female screw N2b. Therefore, the plurality of female screws N2a to N2h are formed at unequal intervals in the circumferential direction, like the plurality of female screws N1a to N1h.

  The annular base 241 has a second mark M2. The second mark M2 is a mark for aligning with the first mark M1 when the grinding wheel 24 is fixed to the wheel mount 23. When the grinding wheel 24 is fixed to the wheel mount 23, the second mark M2 is preferably formed at a place where an operator can easily see. In this embodiment, the 2nd mark M2 is formed in the outer peripheral surface 241c of the cyclic | annular base 241 as a location which an operator is easy to visually recognize. That is, the second mark M2 is formed on the outer peripheral surface 241c of the annular base 241. Similar to the first mark M1, the second mark M2 is formed by so-called laser marking or the like. The second mark M2 is not particularly limited. For example, the second mark M2 has a triangular shape whose apex is located above the vertical direction when viewed in the horizontal direction. That is, in the present embodiment, the second mark M2 is formed in a line-symmetric shape with the horizontal line as an axis with respect to the first mark M1.

  The annular base 241 is fastened and fixed to the wheel mount 23 with a fastening screw S. When the grinding wheel 24 is rotated by the spindle 22, the weight is adjusted in order to suppress vibration associated with the rotation. The adjustment of the weight of the annular base 241 is, for example, a range in which the deviation of the mass center axis from the rotation center axis of the grinding wheel 24 is allowed based on the measurement value of a balance testing machine (so-called balancing machine) for the grinding wheel 24 or the like. So that the outer peripheral surface 241c is subjected to grinding or the like so as to be within the range. That is, the weight of the annular base 241 is adjusted so that when the grinding wheel 24 is fastened to the spindle 22 using the female screws N2a to N2h and rotates, the rotational balance is achieved.

  Here, the fastening screw S is a male screw in which a spiral groove is engraved on the outer periphery of the round bar-shaped shaft portion Sa. The fastening screw S is inserted into the female screws N1a to N1h of the wheel mount 23 only when the first mark M1 and the second mark M2 are positioned at predetermined positions, and the shaft part Sa is ground. Screwed into the female threads N2a to N2h of the wheel 24. That is, the fastening screw S fixes the grinding wheel 24 to the wheel mount 23 only when the first mark M1 and the second mark M2 are positioned at predetermined positions.

  Here, the first mark M1 and the second mark M2 are marks positioned at predetermined positions by the worker. The predetermined position is a position where the second mark M2 is aligned with the first mark M1 when the grinding wheel 24 is coaxially fixed to the wheel mount 23, and the top of the first mark M1 The vertex of the second mark M2 is a position on the vertical line. In the present embodiment, the worker arranges the wheel mount 23 and the grinding wheel 24 on the same axis so as to overlap in the vertical direction, and the worker aligns the second mark M2 with respect to the first mark M1 and fastens it. By fastening the grinding wheel 24 to the wheel mount 23 with the screw S, the first mark M1 and the second mark M2 are positioned at predetermined positions. That is, the lower surface 23c of the wheel mount 23 is engaged with the fastening screw S for fixing the grinding wheel 24 to the wheel mount 23 only when the first mark M1 and the second mark M2 are positioned at predetermined positions. The plurality of female screws N1a to N1h and N2a to N2h formed on the mounting portion 241a of the grinding wheel 24 are formed at unequal intervals in the circumferential direction.

  The grinding wheel 242 is an annular wheel that grinds the workpiece W held on the chuck table 10. The grinding wheel 242 is composed of, for example, a diamond wheel in which diamond abrasive grains are hardened with a binder such as a metal bond or a resin bond. The grinding wheel 242 is formed in an arc shape having a thickness in the radial direction of the annular base 241 when viewed in the vertical direction. The grinding wheel 242 is disposed on the free end 241 d of the annular base 241, that is, the surface opposite to the mounting portion 241 a facing the lower surface 23 c of the wheel mount 23 (that is, the lower surface in the vertical direction). A plurality of the grinding wheels 242 are arranged at equal intervals in the circumferential direction, and are formed in an annular shape when viewed in the vertical direction. The grinding wheel 242 is fixed to the free end 241d with, for example, an adhesive. The free end 241d is formed substantially parallel and flat with respect to the mounting portion 241a.

  As shown in FIG. 1, the driving means 25 rotationally drives the spindle 22 accommodated in the spindle housing 21. The drive means 25 is comprised by the servomotor etc., for example.

  The reciprocating means 30 moves the chuck table 10 relative to the apparatus body 2 in parallel in the horizontal direction. The reciprocating means 30 includes a ball screw and nut, a guide rail, a pulse motor, and the like. The reciprocating feed means 30 supports the reciprocating feed moving base 31 with respect to the apparatus main body 2 so as to be reciprocally movable in parallel with the horizontal direction. The reciprocating feed moving base 31 supports the chuck table 10 in a rotatable manner. The reciprocating feed moving base 31 includes a grinding position where the workpiece W is ground by the grinding means 20 (position on the grinding means 20 side with respect to the apparatus main body 2), a worker and a loading / unloading means. Thus, the chuck table 10 is reciprocated between a loading / unloading position (a position opposite to the grinding means 20 with respect to the apparatus main body 2) at which the workpiece W is attached to and detached from the chuck table 10 (ie, loading / unloading). Move (arrows a and b shown in the figure).

  The grinding feed means 40 moves the grinding means 20 relative to the apparatus main body 2 in parallel with the vertical direction. The grinding feed means 40 includes a ball screw 41, a nut (not shown), a guide rail 42, a pulse motor 43, and the like. The grinding feed means 40 supports the grinding feed moving base 45 so as to be movable up and down in parallel to the vertical direction with respect to the support base 3 erected from the apparatus main body 2. The grinding feed moving base 45 supports the grinding means 20 via the support portion 46. The support portion 46 is disposed on the outer periphery of the spindle housing 21, supports the spindle housing 21, and is supported by the grinding feed moving base 45. That is, the grinding feed moving base 45 moves the grinding means 20 up and down (arrows c and d shown in the figure).

  Next, operation | movement of the grinding device 1 comprised as mentioned above is demonstrated. In the present embodiment, when the rotation axis of the chuck table 10 and the rotation axis of the spindle 22 are slightly tilted within the allowable range for grinding, the mounting portion 241a and the free end portion 241d are substantially It is flat, and the vertical height of the grinding wheel 24 (the vertical thickness of the annular base 241 and the grinding wheel 242 combined) is in-plane due to variations in the in-plane thickness of the annular base 241 in the vertical direction. It is assumed that it is not uniform.

  When the surface of the workpiece W is flattened, the grinding apparatus 1 moves the chuck table 10 to the loading / unloading position (arrow b shown in FIG. 1) based on the grinding process instruction input by the worker. After the workpiece W is placed on the holding surface 10a of the chuck table 10 by the loading / unloading means, the workpiece W is sucked and held by the holding surface 10a by the negative pressure of the vacuum suction source.

  After the workpiece W is sucked and held by the holding surface 10a, the grinding device 1 moves the chuck table 10 to the grinding position (arrow a shown in FIG. 1) while sucking and holding the workpiece W, thereby grinding means. The workpiece W is ground by 20 to flatten the surface of the workpiece W. Here, in the grinding apparatus 1, the grinding wheel 24 is fixed to the wheel mount 23 in a state where the marks M <b> 1 and M <b> 2 are aligned with each other, and the grinding wheel 242 is dressed in advance before performing the grinding process. In the state where the processing is performed and the wheel mount 23 is mounted, the grinding wheel 242 is formed to be flat within a range in which the in-plane thickness variation of the grinding wheel 242 is allowed.

  After the surface of the workpiece W is flattened, the grinding apparatus 1 moves the chuck table 10 to the loading / unloading position while sucking and holding the workpiece W subjected to the grinding process (arrow b shown in FIG. 1). After the suction holding by the vacuum suction source is released, the workpiece W is removed from the holding surface 10a of the chuck table 10 by an operator or carrying-in / out means, and a subsequent process (for example, a cleaning process, a drying process, a storing process, etc.) Carry out.

  Next, a case where a new grinding wheel 24 is mounted will be described. The grinding device 1 stops the rotation of the spindle 22 based on an instruction input for exchanging the grinding wheel 24 by the worker, and the grinding feed means 40 makes the grinding wheel 24 easy to replace the grinding wheel 24. Then, the grinding means 20 is raised (arrow c shown in FIG. 1).

  After the grinding means 20 is raised, the worker loosens the plurality of fastening screws S and removes the grinding wheel 24 from the wheel mount 23, and the outer diameter of the wheel mount 23 and the outer diameter of the new grinding wheel 24 as viewed in the vertical direction. Are overlapped so that the new grinding wheel 24 is coaxially positioned with respect to the wheel mount 23, and the new grinding wheel 24 is arranged below the wheel mount 23 in the vertical direction.

  While arranging the new grinding wheel 24 below the wheel mount 23, the worker rotates the new grinding wheel 24 in the circumferential direction with respect to the first mark M <b> 1 of the wheel mount 23, so that the new grinding wheel 24. The second mark M 2 is aligned, the fastening screw S is tightened, and a new grinding wheel 24 is attached to the wheel mount 23. Here, in the grinding apparatus 1, the plurality of female screws N1a to N1h of the wheel mount 23 and the female screws N2a to N2h of the new grinding wheel 24 are communicated in the vertical direction, and the shaft portion Sa of the fastening screw S is the female screw N1a to N1a. The shaft portion Sa of the fastening screw S is screwed into the female screws N2a to N2h.

  After the new grinding wheel 24 is attached to the wheel mount 23, the grinding apparatus 1 applies the dressing board sucked and held on the chuck table 10 based on the instruction input for dressing processing to the grinding wheel 242 by the worker. By applying grinding processing to the grinding wheel 242 of the new grinding wheel 24, dressing processing is performed. Here, in the grinding apparatus 1, in general, when a new grinding wheel 24 is mounted, or even when the grinding wheel 24 has already been dressed, the vertical direction in which the annular base 241 and the grinding wheel 242 are combined. If the position of the wheel mount 23 is not positioned at a predetermined position because the thickness is not uniform in the plane, the dimensional tolerances between the wheel mount 23 and the annular base 241 are accumulated, so that the number of grinding wheels 242 is several. The grinding wheel 242 becomes parallel to the holding surface 10 a of the chuck table 10 by being consumed by about 100 μm.

  Next, the case where the grinding wheel 24 (including the used grinding wheel) that has already undergone dressing is mounted again will be described. In the grinding apparatus 1, based on an instruction input for replacement of the grinding wheel 24 by the worker, the rotation of the spindle 22 is stopped, and then a plurality of fastening screws S are loosened by the worker, and the grinding wheel is removed from the wheel mount 23. 24 is removed.

  After the grinding wheel 24 is removed from the wheel mount 23, the worker overlaps the outer diameter of the wheel mount 23 and the outer diameter of the grinding wheel 24 that has already undergone dressing processing in the vertical direction. On the other hand, the grinding wheel 24 already dressed is arranged below the wheel mount 23 so that the grinding wheel 24 already dressed is positioned coaxially.

  An operator places the grinding wheel 24 already dressed against the first mark M1 of the wheel mount 23 while the grinding wheel 24 already dressed is disposed below the wheel mount 23. By rotating in the direction, the second mark M2 of the grinding wheel 24 already dressed is aligned, the fastening screw S is tightened, and the grinding wheel 24 already dressed on the wheel mount 23 is Install. Here, in the grinding apparatus 1, the grinding wheel 24 that has already undergone dressing is mounted on the wheel mount 23 in a state where the second mark M2 is aligned with the first mark M1. That is, in the grinding apparatus 1, the grinding wheel 24 that has already undergone dressing processing is fixed to the wheel mount 23 at a predetermined position. For this reason, in the grinding apparatus 1, even if the vertical thickness of the annular base 241 and the grinding wheel 242 is not uniform in the surface, the already-ground dressing wheel 24 is in a predetermined position. When fixed, the grinding wheel 242 is substantially parallel to the holding surface 10 a of the chuck table 10.

  After the grinding wheel 24 that has already been dressed is attached to the wheel mount 23, the grinding device 1 is sucked and held by the chuck table 10 based on an instruction input for dressing processing to the grinding wheel 242 by an operator. By applying grinding to the dressing board, the grinding wheel 242 of the grinding wheel 24 that has already been dressed is subjected to dressing. Here, in the grinding apparatus 1, the grinding wheel 242 becomes parallel to the holding surface 10 a of the chuck table 10 when the grinding wheel 242 is consumed by several tens of μm.

  As described above, according to the grinding device 1 according to the embodiment, the plurality of females formed at unequal intervals in the circumferential direction by aligning the first mark M1 and the second mark M2. The screws N1a to N1h and N2a to N2h can be communicated with each other in the vertical direction. Therefore, according to the grinding device 1, the first mark M1 and the second mark M2 can be positioned at predetermined positions by fastening the fastening screw S to the female threads N2a to N2h of the grinding wheel 24. The grinding wheel 24 can be fixed to the wheel mount 23 at a predetermined position. Further, according to the grinding apparatus 1, in the grinding wheel 24 that has already undergone dressing processing, a slight inclination between the rotation axis of the chuck table 10 and the rotation axis of the spindle 22 and in-plane thickness variation of the entire grinding wheel 24. Are accumulated at predetermined positions, the lower surface of the grinding wheel 242 in the vertical direction is parallel to the holding surface 10 a of the chuck table 10. In other words, according to the grinding apparatus 1, when the grinding wheel 24 that has already been dressed is mounted on the wheel mount 23 again at a predetermined position, the grinding wheel 242 is made substantially parallel to the holding surface 10 a of the chuck table 10. be able to. According to the grinding apparatus 1, the amount of wear of the grinding wheel 242 when the grinding wheel 24 already dressed is not fixed to the wheel mount 23 at a predetermined position is several hundred μm. When the grinding wheel 24 subjected to the dressing process is fixed to the wheel mount 23 at a predetermined position, the consumption amount of the grinding wheel 242 can be set to several tens of μm. Therefore, according to the grinding device 1, there is an effect that it is possible to reduce the amount of wear of the grinding wheel 242 due to dressing when the grinding wheel 24 that has already undergone dressing is mounted again.

  Moreover, according to the grinding apparatus 1 which concerns on embodiment, the use limit of the grinding wheel 24 is reduced by reducing the consumption of the grinding wheel 242 by the dressing process when the grinding wheel 24 which has already been dressed is mounted again. Can be extended.

  Further, according to the grinding apparatus 1 according to the embodiment, the weight of the annular base 241 is such that the grinding wheel 24 fixed to the wheel mount 23 by the fastening screw S has a rotational balance when rotated by the spindle 22. Since it is adjusted, vibration during rotation can be suppressed. Therefore, according to the grinding apparatus 1, the workpiece W can be stably ground.

  In the above-described embodiment, the plurality of female screws N1a to N1h are formed at unequal intervals in the circumferential direction by forming the female screw N1a closest to the first mark M1 on the female screw N1b side. The positions of the female screws N1d to N1f separated from the first mark M1 may be shifted, or the positions of several female screws N1a to N1h may be shifted to make the plurality of female screws N1a to N1h unequal in the circumferential direction. It may be formed at intervals.

  In the above embodiment, the plurality of female screws N1a to N1h and N2a to N2h are formed at unequal intervals in the circumferential direction, but are formed at unequal distances from the rotation center. It may be a thing. The plurality of female screws N1a to N1h and N2a to N2h being formed at unequal distances from the rotation center means that the plurality of female screws N1a to N1h and N2a to N2h adjacent in the circumferential direction and the rotation center The plurality of angles formed from the same is the same, and at least one distance from the center of rotation is different. Even when the plurality of female screws N1a to N1h and N2a to N2h are formed at unequal distances from the rotation center as described above, when the marks M1 and M2 are aligned with each other, the plurality of female screws N1a to N1h are arranged. , N2a to N2h communicate with each other in the vertical direction and can be fastened by the fastening screw S, so that the holding surface of the chuck table 10 can be mounted even if the grinding wheel 24 that has already been dressed is mounted again. The grinding wheel 242 can be parallel to 10a.

  The plurality of female screws N1a to N1h and N2a to N2h may be formed at unequal intervals in the circumferential direction and at unequal distances from the rotation center. Note that the plurality of female screws N1a to N1h and N2a to N2h being formed at unequal intervals in the circumferential direction and at unequal distances from the rotation center means that the plurality of female screws N1a to N1h adjacent in the circumferential direction are Among the plurality of angles formed with the rotation center, at least two angles are different, and at least one distance from the rotation center is different. Even when the plurality of female screws N1a to N1h and N2a to N2h are formed at unequal intervals in the circumferential direction and at unequal distances from the rotation center, the marks M1 and M2 are aligned with each other. The plurality of female screws N1a to N1h and N2a to N2h communicate with each other in the vertical direction and can be fastened by the fastening screw S so that the grinding wheel 24 that has already undergone dressing is mounted again. In addition, the grinding wheel 242 can be parallel to the holding surface 10 a of the chuck table 10.

  Further, in the above-described embodiment, it is formed at unequal intervals in the circumferential direction or at unequal distances from the rotation center. However, the present invention is not limited to this. For example, one or a plurality of female screws N1a are formed. N1h and N2a to N2h may be formed with unequal hole diameters, and the grinding wheel 24 may be fixed to the wheel mount 23 with a fastening screw S having a shaft portion Sa corresponding to the unequal hole diameter. In such a case, by configuring the fastening screw S that does not correspond to the unequal hole diameter so as not to be screwed with the female screws N2a to N2h, the wheel mount is only provided when the marks M1 and M2 are positioned at predetermined positions. The grinding wheel 24 can be fixed to 23.

DESCRIPTION OF SYMBOLS 1 Grinding device 10 Chuck table 10a Holding surface 20 Grinding means 21 Spindle housing 22 Spindle 22a Spindle tip 23 Wheel mount 23a Outer peripheral surface 23b Upper surface 23c Lower surface 24 Grinding wheel 241 Annular base 241a Mounting portion 241c Outer peripheral surface 241d Free end 242 Grinding Grindstone M1 First mark M2 Second mark N1a to N1h, N2a to N2h Female thread S Fastening screw W Workpiece

Claims (2)

A grinding apparatus comprising: a chuck table for holding a plate-like workpiece on a holding surface; and a grinding means for grinding the workpiece held on the chuck table,
The grinding means includes
A spindle rotatably accommodated in the spindle housing;
A wheel mount fixed to the spindle tip exposed from the spindle housing;
A grinding wheel comprising an annular base having a mounting portion attached to the wheel mount; and an annular grinding wheel disposed at a free end of the annular base;
A first mark is formed on the outer peripheral side surface of the wheel mount or the upper surface of the wheel mount,
On the outer peripheral surface of the annular base of the grinding wheel, a second mark is formed for alignment with the first mark when the grinding wheel is fixed to the wheel mount.
The lower surface of the wheel mount and the lower surface of the grinding wheel are threaded so that a fastening screw for fixing the grinding wheel is screwed to the wheel mount only when the first mark and the second mark are positioned at predetermined positions. A grinding apparatus in which a plurality of female screws formed in the mounting portion are formed at unequal intervals in the circumferential direction or at unequal distances from the rotation center.   The grinding apparatus according to claim 1, wherein the weight of the annular base is adjusted so that the grinding wheel is balanced when rotated by being fastened to the spindle using the female screw.

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