Grinding apparatus

Abstract

(Problem) In a grinding device that uses a grinding wheel mounted on the tip of a spindle, the replacement of the grinding wheel is facilitated. (Solution) A grinding device that fastens a grinding wheel to a mounting disc connected to the tip of a spindle by means of a bolt, wherein the mounting disc has at least three female screw holes that penetrate the upper and lower surfaces and are arranged at equal intervals on the circumference, and a convex portion protruding from the mounting surface, and the bolt has a male screw portion, a neck portion at the tip of the male screw, and a engaging portion protruding from the neck portion. The grinding wheel includes an annular opening formed annularly on the mounting surface of an annular base, an annular groove formed annularly within the annular base and connected to the annular opening and having a width wider than the annular opening, an insertion hole arranged at least three times in the annular opening and capable of inserting the engaging portion into the annular groove, and a convex portion insertion hole capable of inserting the convex portion.

Description

Technology Field

[0001] The present invention relates to a grinding device having a grinding wheel in which a plurality of grinding wheels are arranged in an annular shape. Background Technology

[0002] A grinding device for grinding various plate-shaped workpieces, such as semiconductor wafers, is equipped with a mounting disc at the tip of a spindle, and a grinding wheel is mounted on the mounting disc. A plurality of grinding wheels arranged in an annular shape are provided on the lower side of the grinding wheel, and grinding is performed by rotating the grinding wheels by rotating the spindle and bringing the rotating grinding wheels into contact with the workpiece. Since the grinding wheel needs to be replaced when the grinding wheels wear out, a mechanism has been proposed to facilitate the replacement of the grinding wheel.

[0003] For example, in the following patent document 1, a grinding device is proposed that does not require cumbersome operations such as fixing by screws, by providing a first chuck claw and a second chuck claw on a base on the spindle side and configuring them to support a grinding wheel. In addition, in the following patent document 2, a grinding device is proposed that mounts a grinding wheel to a spindle by bringing the wheel engagement portion of a grinding unit close to a grinding wheel mounted on a chuck table and engaging it with the grinding wheel. Prior art literature

[0004] Patent Document 1: Japanese Published Patent Application No. 2019-202399 Patent Document 2: Japanese Published Patent Application No. 2021-112781 The problem to be solved

[0005] However, in order to equip an existing grinding device with a mechanism as disclosed in the aforementioned patent documents 1 and 2, it is necessary to modify the mount disc. In addition, since it is necessary to change the settings of the motor controller that controls the motor rotating the spindle to accommodate the mount disc that has become heavier due to the modification, it takes time to modify the grinding device and change the settings. Furthermore, there are cases where it is necessary to replace the spindle itself on which the mount disc is mounted.

[0006] Accordingly, the objective of the present invention is to provide a grinding device that uses a grinding wheel mounted on the tip of a spindle, wherein the modification of the mounting disc in the existing grinding device is performed in a short time, thereby facilitating the replacement of the grinding wheel. means of solving the problem

[0007] According to the present invention, a grinding device is provided for grinding a workpiece held on a chuck table by the grinding wheels, wherein a grinding wheel having a plurality of grinding wheels fixed annularly on an annular base is fastened by a bolt to a mount disk connected to the tip of a spindle. The grinding device is provided for grinding a workpiece held on a chuck table by the grinding wheels. The mount disk includes at least three female screw holes penetrating the upper and lower surfaces and arranged at equal intervals on the circumference, and a plurality of convex portions protruding from a mounting surface for mounting the grinding wheel. The bolt includes a male screw portion, a neck portion connected to the tip of the male screw portion, and a engaging portion connected to the tip of the neck portion and protruding from the neck portion. The grinding wheel includes an annular opening formed annularly on the mounting surface of the annular base, an annular groove connected to the annular opening and having a width wider than the annular opening and formed annularly within the annular base, at least three insertion holes arranged in the annular opening and capable of inserting the engaging portion into the annular groove, and capable of inserting the convex portion. A grinding device is provided that includes a plurality of convex insertion holes, and when mounting the grinding wheel to the mount disk, screws the male screw portion into the female screw hole to protrude the engagement portion from the mounting surface, inserts the engagement portion into the annular groove from the insertion hole, rotates the mount disk and the grinding wheel relative to each other, and rotates the bolt at a position where the convex insertion hole and the convex portion coincide to insert the convex portion into the convex insertion hole, and fastens the mount disk and the grinding wheel with the bolt.

[0008] Preferably, the convex portion, the engaging portion, the insertion hole, and the convex portion insertion hole are formed in a cylindrical shape. Effects of the invention

[0009] In the grinding device of the present invention, since the grinding wheel can be easily replaced without providing a complex mechanism on the mount disc, the mounting disc can be made heavier. Therefore, it is not necessary to change the settings of the controller of the motor that rotates the spindle. Furthermore, since there is no need to hold the grinding wheel by suction force, there is no need to communicate with a suction source, and there is no need to replace the spindle. Brief explanation of the drawing

[0010] FIG. 1 is a perspective view illustrating an example of a grinding device. FIG. 2 is a bottom view illustrating an embodiment of a mount disk. FIG. 3 is a cross-sectional view schematically illustrating an enlarged portion of a mount disc, a bolt, and a grinding wheel. FIG. 4 is a plan view illustrating an embodiment of an annular base. FIG. 5 is a cross-sectional view schematically illustrating the state before inserting the bolt into the female screw hole of the mount disc. FIG. 6 is a cross-sectional view schematically illustrating the state in which a bolt is inserted into the female screw hole of a mount disc. FIG. 7 is a cross-sectional view schematically illustrating a state in which a mating part engages with an annular groove, causing the mount disk and the grinding wheel to rotate relative to each other. FIG. 8 is a cross-sectional view schematically illustrating the state in which the mounting disk and the grinding wheel are fastened by a bolt by inserting the convex portion of the mounting disk into the convex portion insertion hole. Specific details for implementing the invention

[0011] The grinding device (1) illustrated in FIG. 1 is a device for grinding a workpiece held on a chuck table (2) using a grinding mechanism (3), the chuck table (2) is driven by a moving mechanism (4) to move in the Y-axis direction, and the grinding mechanism (3) is driven by a grinding feed mechanism (5) to move in the Z-axis direction.

[0012] The chuck table (2) includes a suction portion (21) formed by a porous member and a frame (22) supporting the suction portion (21), and the surface of the suction portion (21) forms a holding surface (210) that holds the workpiece (10). The holding surface (210) and the upper surface (220) of the frame (22) are in the same plane.

[0013] A table base (23) is provided below the chuck table (2), and the table base (23) is supported at least three times by three chuck support members (24) (only two are shown in FIG. 1). A load measuring device (25) is disposed on each chuck support member (24) to measure the vertical load when the grinding mechanism (3) presses the workpiece held by the holding surface (200). In addition, at least two chuck support members (24) have the function of adjusting the height of the chuck table (2) to adjust the inclination of the holding surface (210).

[0014] The grinding mechanism (3) comprises a spindle (30) having a rotation axis in the Z-axis direction, a motor (31) for rotating the spindle (30), a spindle housing (32) for rotatably supporting the spindle (30), a mount disk (6) connected to the lower end of the spindle (30), and a grinding wheel (34) mounted on the mount disk (33). The upper end of the spindle (30) is provided with a grinding water inlet (301) for introducing grinding water. When the motor (31) rotates the spindle (30), the grinding wheel (34) also rotates. The grinding wheel (34) is composed of an annular base (7) fixed to the mount disk (6) and a plurality of grinding stones (8) annularly fixed to the lower surface of the annular base (7).

[0015] The moving mechanism (4) comprises a ball screw (40) having a rotation axis in the Y-axis direction, a motor (41) that rotates the ball screw (40), a pair of guide rails (42) arranged parallel to the ball screw (40), and a slide plate (43) having an unillustrated nut inside which the bottom portion slides in contact with the guide rails (42) and is screw-coupled to the ball screw (40). A chuck support (24) and a load measuring device (25) are arranged above the slide plate (43). When the ball screw (40) rotates, the slide plate (43) is guided by the guide rails (42) and moves in the Y-axis direction, and the chuck table (2) is configured to move in the same direction as the slide plate (43) moves in the Y-axis direction.

[0016] The grinding feed mechanism (5) comprises a ball screw (50) having a rotation axis in the Z-axis direction, a motor (51) that rotates the ball screw (50), a pair of guide rails (52) arranged parallel to the ball screw (50), a lifting plate (53) having an unillustrated nut inside which the side slides in contact with the guide rails (52) and is screw-coupled to the ball screw (50), and a holder (54) connected to the lifting plate (53) and supporting the spindle housing (32). When the ball screw (50) rotates, the lifting plate (53) is guided by the guide rails (52) and moves in a direction perpendicular to the holding surface (200), and thereby the grinding mechanism (3) also moves in the same direction, so that the grinding wheel (8) is configured to approach or move away from the holding surface (200) relatively. The position of the grinding mechanism (3) in the Z-axis direction is recognized by an encoder (55) equipped in the motor (51).

[0017] A thickness measuring device (9) for measuring the thickness of a wafer held on the chuck table (2) is positioned on the side of the movement path in the Y-axis direction of the chuck table (2). The thickness measuring device (9) is equipped with a first measuring unit (91) for measuring the height of the upper surface of the wafer held on the holding surface (210) of the suction unit (21), and a second measuring unit (92) for measuring the height of the upper surface (220) of the frame (22), and calculates the difference between the measurement value of the first measuring unit (91) and the measurement value of the second measuring unit (92) as the thickness of the wafer.

[0018] As shown in FIG. 2, the mount disk (6) is formed in an annular shape. The lower surface of the mount disk (6), that is, the mounting surface (60) on which the grinding wheel (34) is mounted, is provided with two cylindrical convex portions (61) that protrude downward. The two convex portions (61) are formed 180 degrees apart on the same circumference.

[0019] Additionally, the convex portion (61) may be integral with the mount disk (6) or may be detachable. In the case of a detachable type, for example, a female screw may be formed on the mounting surface (60) of the mount disk (6) and a male screw may be formed on the tip of the convex portion, and the position of the convex portion may be changed depending on the type of grinding wheel. Additionally, depending on the type of grinding wheel, the shape of the convex portion (61) may be changed to a polygonal column.

[0020] Eight female screw holes (62) are formed in the mount disk (6), and these are formed at equal intervals on the same circumference. In the example shown in FIG. 2, eight female screw holes (62) are formed, but at least three are formed. As shown in FIG. 3, the female screw holes (62) penetrate the upper and lower surfaces of the mount disk (6). In addition, the mount disk (6) has a grinding water channel (63) formed therein, which serves as a passage for grinding water that flows in from the grinding water inlet (301) shown in FIG. 1, passes through an unillustrated channel inside the spindle (30), and flows into the mount disk.

[0021] A bolt (64) as shown in FIG. 3 is inserted into this female screw hole (62). The bolt (64) has a male screw portion (641), a neck portion (642) connected to the tip of the male screw portion (641), and a cylindrical engagement portion (643) connected to the tip of the neck portion (642), formed with a larger diameter than the neck portion (642), and protruding outward from the neck portion (642). The bolt (64) has a plunger (644) protruding in the direction of protrusion by a spring (645). The bolt (64) is a hexagonal bolt, and an engagement portion (646) of a hexagonal wrench is formed adjacent to the male screw portion (641).

[0022] As shown in FIG. 4, an annular opening (71) is formed on the upper surface of the annular base (7) of the grinding wheel (34), that is, on the mounting surface (60) of the mount disk (6). As shown in FIG. 5, an annular groove (72) with a bottom that is an annular space is formed inside the annular base (7). The annular groove (72) is wider than the annular opening (71) and communicates with the annular opening (71) in the vertical direction. In addition, the annular base (7) is provided with a grinding water ejection part (73) that is open at the top and communicates with the grinding water flow path (63) of the mount disk (6), and is open at the bottom.

[0023] As shown in FIG. 4, the annular opening (71) has insertion holes (74) formed at equal intervals, which are cylindrical spaces that allow the fitting part (643) to be inserted and passed through, i.e., the inner diameter is formed slightly larger than the outer diameter of the fitting part (643). In the example of FIG. 4, eight insertion holes (74) are formed, but at least three are required.

[0024] In the annular opening (71), convex insertion holes (75), which are cylindrical spaces into which the convex portions (61) of the mount disk (6) are inserted, are formed at equal intervals. The number of convex insertion holes (75) is equal to the number of convex portions (61). In the example of FIG. 2, since two convex portions (61) are formed at 180-degree intervals, two convex insertion holes (75) are also formed at 180-degree intervals in correspondence.

[0025] Next, the sequence of attaching the annular base (7) of the grinding wheel (34) to the mount disk (6) will be explained with reference to FIGS. 5 to 8. The mount disk (6) in FIG. 5 shows the AOB cross-section of FIG. 2. Also, the grinding wheel (34) in FIGS. 5 and FIG. 6 shows the AOB cross-section of FIG. 4.

[0026] First, as shown in FIG. 5, the male threaded portion (641) of the bolt (64) is screwed into the female threaded hole (62) of the mount disk (6), and as shown in FIG. 6, the engaging portion (643) is protruded from the mounting surface (60). Next, the engaging portion (643) is inserted through the insertion hole (74) shown in FIG. 4, and the engaging portion (643) is inserted to the depth of the annular groove (72). Then, with the engaging portion (643) positioned in the annular groove (72), the mount disk (6) and the grinding wheel (34) are rotated relative to each other.

[0027] As shown in FIG. 7, by the relative rotation of the mount disk (6) and the grinding wheel (34), the neck portion (642) is inserted into the annular opening (71), and the engaging portion (643) is inserted into the annular groove (72) and engages. Then, as the relative rotation between the mount disk (6) and the grinding wheel (34) continues, the position of the convex insertion hole (75) formed in the annular base (7) and the position of the convex portion (61) formed in the mount disk (6) coincide. It is preferable that the annular groove (72) has a concave portion formed therein into which the tip of the plunger (64) enters when the position of the convex insertion hole (75) and the position of the convex portion (61) coincide. When the mount disk (6) and the grinding wheel (34) rotate relative to each other, the plunger (644) is pushed in the protruding direction by the spring (645), so the tip of the plunger (644) is pressed against the bottom of the annular groove (72), thereby preventing the mount disk (6) and the grinding wheel (34) from rotating freely.

[0028] When the position of the convex insertion hole (75) and the position of the convex part (61) coincide, the relative rotation between the mount disk (6) and the grinding wheel (34) is stopped at that position, and as shown in FIG. 8, a hexagonal wrench is attached to the wrench engagement part (646) of the bolt (64) and the bolt (64) is rotated inside the female screw hole (62) to bring the mount disk (6) and the annular base (7) closer together and close them. By doing so, the convex part (61) is inserted into the convex insertion hole (75). Then, the bolt (64) is further rotated to fasten the mount disk (6) and the annular base (7) of the grinding wheel (34) by the bolt (64).

[0029] In this way, the engagement portion (643) of the bolt (64) inserted into the female screw hole (62) of the mount disk (6) is coupled to the annular groove (72) of the annular base (7), thereby rotating the annular base (7) and the mount disk (6) relative to each other, and the bolt (64) is tightened while the position of the convex insertion hole (75) and the position of the convex portion (61) are aligned, so that the grinding wheel (34) can be mounted on the mount disk (6). Additionally, the grinding wheel (34) can be separated from the mount disk (6) by loosening the bolt (64), rotating the annular base (7) and the mount disk (6) relative to each other, and pulling the engagement portion (643) out of the insertion hole (74).

[0030] Additionally, a recess may be formed in the annular groove (72) at the center of the insertion hole (74) into which the tip of the plunger (644) enters. By doing so, the operator can see that the grinding wheel (34) is in a position to be removed from the mount disk (6).

[0031] In this way, since the grinding wheel (34) can be easily replaced without providing a complex mechanism in the mount disk (6), the mounting disk (6) can avoid becoming heavy. Therefore, it is not necessary to change the settings of the controller of the motor (31) that rotates the spindle (30). In addition, since the mount disk (6) does not need to hold the grinding wheel (34) by suction force, there is no need to communicate with the suction source, and there is no need to replace the spindle (30).

[0032] Additionally, in the annular base (7) of the present embodiment, an insertion hole (74) and a convex insertion hole (75) are installed separately, but the insertion hole (74) may also serve as the convex insertion hole (75). Explanation of the symbols

[0033] 1: Grinding device 2: Chuck Table 21: Suction part, 210: Retention surface 22: Frame, 220: Top surface 23: Table base, 24: Chuck retainer, 25: Load gauge 3: Grinding mechanism 30: Spindle 301: Grinding fluid inlet 31: Motor, 32: Spindle housing, 33: Mount disc 34: Grinding Wheel 4: Transportation devices 40: Ball screw, 41: Motor, 42: Guide rail, 43: Slide plate 5: Grinding feed mechanism 50: Ball screw, 51: Motor, 52: Guide rail, 53: Lifting plate, 54: Holder 55: Encoder 6: Mount disk 60: Mounting surface, 61: Convex portion, 62: Female thread hole, 63: Grinding fluid passage 64: Bolt 641: Male thread section, 642: Neck section, 643: Interlocking section, 644: Plunger 7: Circular base 70: Mounting surface, 71: Annular opening, 72: Annular groove, 73: Grinding fluid ejection part, 74: Insertion hole 75: Convex insertion hole 8: Grinding wheel 9: Thickness gauge, 91: First measuring part, 92: Second measuring part

Claims

Claim 1 A grinding device for grinding a workpiece held on a chuck table by the grinding wheels, wherein a grinding wheel having a plurality of grinding wheels fixed annularly on an annular base is fastened by a bolt to a mount disc connected to the tip of a spindle, and the grinding device comprises: at least three female screw holes penetrating the upper and lower surfaces and arranged at equal intervals on the circumference, and a plurality of convex portions protruding from a mounting surface for mounting the grinding wheel; wherein the bolt comprises a male screw portion inserted into the female screw hole, a neck portion connected to the tip of the male screw portion, and a engaging portion connected to the tip of the neck portion and protruding from the neck portion; wherein an external tool engaging portion for engaging with an external tool is formed on the opposite side of the tip of the male screw portion and protrudes from the upper surface of the mount disc; and wherein the grinding wheel comprises an annular opening formed annularly on the mounting surface of the annular base, and a portion communicating with the annular opening in the vertical direction and having a width wider than the annular opening, and within the annular base A grinding device comprising an annular groove formed concentrically with the annular opening and formed in an annular shape, at least three insertion holes arranged in the annular opening and capable of inserting the engaging portion into the annular groove, and a plurality of convex portion insertion holes capable of inserting the convex portion, wherein when mounting the grinding wheel on the mount disk, the male screw portion is screw-inserted into the female screw hole to protrude the engaging portion from the mounting surface and simultaneously protrude the external tool engaging portion from the upper surface of the mount disk, and after inserting the engaging portion into the annular groove from the insertion hole, the mount disk and the grinding wheel are rotated relative to each other, and at a position where the convex portion insertion hole and the convex portion coincide, the external tool is coupled to the external tool engaging portion protruding from the upper surface of the mount disk and the bolt is rotated inside the female screw hole to insert the convex portion into the convex portion insertion hole and simultaneously fasten the mount disk and the grinding wheel with the bolt. Claim 2 A grinding device according to claim 1, wherein the convex insertion hole is the insertion hole. Claim 3 A grinding device according to claim 1, wherein the convex portion, the mating portion, the insertion hole, and the convex portion insertion hole are formed in a cylindrical shape.

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