Dressing Tools

Abstract

To provide a dressing tool that can grasp a thickness of the dressing tool without measuring the thickness of the dressing tool, so as to simplify dressing of a grinding stone.SOLUTION: A plurality of grooves having depths different from each other are formed on an upper surface side of a dressing board, so that when the upper surface side of the dressing board is ground by dressing of a grinding stone and therefore a thickness of the dressing board is reduced, the number of the plurality of grooves formed on the upper surface side of the dressing board reduces. Therefore, a thickness of a dressing tool can be grasped without actually measuring the thickness of the dressing tool, by visually recognizing the upper surface side of the dressing board to recognize the number of the plurality of grooves which remain. This can simplify the dressing of the grinding stone.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a dressing tool having a dressing board for dressing a grinding wheel. [Background technology]

[0002] Device chips such as IC (Integrated Circuit) and LSI (Large Scale Integration) are essential components in various electronic devices such as mobile phones, personal computers, etc. These chips are manufactured, for example, by thinning a wafer on which many devices are formed and then dividing it into regions containing individual devices.

[0003] Methods for thinning the wafer include, for example, grinding using a grinding device having a grinding wheel with a plurality of grinding stones arranged discretely in a ring shape and a chuck table that holds the front surface side of the wafer by suction.

[0004] In this grinding device, the grinding wheel and the chuck table are rotated while the grinding surface of the grinding wheel and the back surface of the wafer are brought into contact with each other while water or the like is being supplied to the grinding surface of the grinding wheel and the back surface of the wafer (see, for example, Patent Document 1). As a result, the back surface of the wafer is ground by the grinding surface of the grinding wheel, thereby thinning the wafer.

[0005] The grinding wheel has a bond material, such as a vitrified bond or a resin bond, having pores therein, and abrasive grains, such as diamond or cubic boron nitride (cBN), dispersed in the bond material. The wafer is ground by the abrasive grains exposed on the grinding surface of the grinding wheel.

[0006] However, in an unused grinding wheel, the abrasive grains may not be sufficiently exposed on the grinding surface of the grinding wheel, and the grinding surfaces of the multiple grinding wheels included in the grinding wheel may not be located on the same plane.

[0007] Furthermore, if grinding debris produced by grinding adheres to the grinding surface of the grinding wheel, the abrasive grains may not be fully exposed on the grinding surface of the grinding wheel (the grinding surface may become clogged).In addition, repeated grinding may cause the abrasive grains exposed on the grinding surface to wear out (the grinding surface may become worn).

[0008] In these cases, the grinding efficiency of the grinding device may decrease. Therefore, in the grinding device, a process (dressing) is often performed at an appropriate timing to grind the grinding surfaces of the multiple grinding wheels to prepare them in a state suitable for grinding.

[0009] Such dressing is performed, for example, by bringing the grinding surface of the grinding wheel into contact with a dressing board of a dressing tool that is suction-held on a chuck table while rotating the grinding wheel (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0010] [Patent Document 1] JP 2014-124690 A [Patent Document 2] JP 2009-142906 A Summary of the Invention [Problem to be solved by the invention]

[0011] When the grinding wheel is dressed, the contact surface of the dressing board with the grinding wheel is also worn down, so the thickness of the dressing board decreases with repeated dressing of the grinding wheel.

[0012] If the dressing of the grinding wheel is performed without changing conditions such as the distance between the chuck table and the grinding wheel even though the thickness of the dressing board is reduced, the grinding surface side of the grinding wheel is not sufficiently ground, i.e., in this case, the grinding wheel is not appropriately dressed.

[0013] In order to perform appropriate dressing of the grinding wheel, it is necessary to know the thickness of the dressing tool including the dressing board in advance. Therefore, dressing of the grinding wheel is often performed after the thickness of the dressing tool including the dressing board is measured.

[0014] In view of this, an object of the present invention is to provide a dressing tool that allows the thickness of the dressing tool to be known without measuring the thickness of the dressing tool, in order to simplify the dressing of a grinding wheel. [Means for solving the problem]

[0016] According to one aspect of the present invention, a grinding tool is provided that includes a dressing board for dressing a grinding wheel and a support plate to which the dressing board is fixed on an upper surface thereof, and a plurality of grooves having different depths are formed on the upper surface side of the dressing board. The upper surface of the support plate includes a plurality of locations in which information regarding the depth of each of a plurality of grooves is visibly displayed, and each of the plurality of locations is provided with information regarding the depth of a groove that is closest to the plurality of grooves. A dressing tool is provided . Effect of the Invention

[0017] In the present invention, a plurality of grooves having different depths are formed on the upper surface side of the dressing board. As a result, when the upper surface side of the dressing board is scraped by dressing with a grinding wheel and the thickness of the dressing board is reduced, the shallow grooves are lost and the number of the plurality of grooves formed on the upper surface side of the dressing board is reduced.

[0018] Therefore, in the present invention, by visually checking the upper surface side of the dressing board and recognizing the number of remaining grooves, the thickness of the dressing tool can be grasped without actually measuring the thickness of the dressing tool, which simplifies the dressing of the grinding wheel. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1(A) is a plan view that shows a schematic diagram of an example of a dressing tool, and FIG. 1(B) is a front view that shows a schematic diagram of an example of a dressing tool. [Diagram 2] FIG. 2 is a perspective view that illustrates an example of a grinding device. [Diagram 3] FIG. 3 is a plan view that illustrates a schematic example of a dressing tool used for dressing a grinding wheel. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the accompanying drawings, in which Fig. 1(A) is a plan view showing an example of a dressing tool, and Fig. 1(B) is a front view showing an example of the dressing tool.

[0021] The dressing tool 2 shown in Figures 1(A) and 1(B) comprises a disk-shaped dressing board 4 having parallel circular upper and lower surfaces, and a disk-shaped support plate 6 having parallel upper and lower surfaces, to the upper surface of which the dressing board 4 is fixed.

[0022] The dressing board 4 and the support plate 6 are fixed so that the center of the lower surface of the dressing board 4 and the center of the upper surface of the support plate are in contact with each other. The diameters of the upper and lower surfaces of the dressing board 4 are shorter than the diameters of the upper and lower surfaces of the support plate 6.

[0023] The dressing board 4 is made of, for example, green carborundum (GC) abrasive grains made of silicon carbide (SiC) or aluminum oxide (Al 2 O 3 The support plate 6 is formed by kneading white alundum (WA) abrasive grains made of WA with a binder made of vitrified bond or resin bond, and then firing the mixture. The support plate 6 is made of, for example, polyvinyl chloride.

[0024] Furthermore, a plurality of grooves 8 (30 grooves, as an example, in Figures 1(A) and 1(B)) each having a different depth from the upper surface (respective height from the lower surface) are formed on the upper surface side of the dressing board 4. Each of the plurality of grooves 8 extends from the outer edge of the dressing board 4 along the radial direction of the upper surface or lower surface of the dressing board 4.

[0025] The length of each of the multiple grooves 8 along the direction is approximately equal, and is shorter than the radius of the upper and lower surfaces of the dressing board 4. The multiple grooves 8 are also provided at approximately equal intervals along the circumferential direction of the dressing board 4.

[0026] More specifically, the dressing board 4 shown in Figures 1(A) and 1(B) has a thickness of 1100 µm, and the support plate 6 has a thickness of 1000 µm. The upper surface side of the dressing board 4 is provided with a groove 8a having a depth of 30 µm, a groove 8b having a depth of 900 µm provided adjacent to the groove 8a, and 28 grooves with a difference in depth between adjacent grooves of 30 µm.

[0027] Therefore, for example, the groove 8a having a depth of 30 μm and the groove 8c having a depth of 480 μm included in the 28 grooves are arranged in a position that is point-symmetrical with respect to the center point of the upper surface of the dressing board 4 in a plan view. Similarly, the groove 8b having a depth of 900 μm and the groove 8d having a depth of 450 μm included in the 28 grooves are arranged in a position that is point-symmetrical with respect to the center point of the upper surface of the dressing board 4 in a plan view.

[0028] The upper surface of the support plate 6 also includes a plurality of locations 10 at which information regarding the depths of the plurality of grooves 8 is visibly displayed. Each of the plurality of locations 10 displays information regarding the depth of the groove 8 that is closest to the other of the plurality of grooves 8.

[0029] More specifically, the upper surface of the support plate 6 shown in Figures 1(A) and 1(B) includes 30 locations 10 at which information regarding the depth of the 30 grooves 8 is displayed in a visible manner. The 30 locations 10 are located outside the dressing board 4 and are arranged at approximately equal intervals along the circumferential direction of the dressing board 4. In addition, at each of the 30 locations 10, the distance between the bottom surface of the groove 8 and the lower surface of the support plate 6 is displayed as information regarding the depth of the closest groove 8 among the 30 grooves 8.

[0030] For example, at point 10a closest to groove 8a having a depth of 30 μm, the distance between the bottom surface of groove 8a and the underside of support plate 6 is shown to be (1100 μm (thickness of dressing board) + 1000 μm (thickness of support plate) - 30 μm = 2070 μm). Similarly, at point 10b closest to groove 8b having a depth of 900 μm, the distance between the bottom surface of groove 8b and the underside of support plate 6 is shown to be (1100 μm + 1000 μm - 900 μm = 1200 μm).

[0031] The grooves 8 are formed, for example, by cutting the dressing board 4 using a known cutting device. Information regarding the depths of the grooves 8, such as the distance between each of the grooves 8 and the lower surface of the support plate 6, is printed, for example, by processing the multiple locations 10 of the support plate 6 using a known laser processing device.

[0032] Fig. 2 is a perspective view showing a schematic example of a grinding apparatus that dresses a grinding wheel using a dressing tool 2. The grinding apparatus 12 shown in Fig. 2 has a chuck table 14 capable of holding a workpiece such as a wafer or the dressing tool 2. The chuck table 14 has a disk-shaped frame 16 made of, for example, ceramics.

[0033] A recess having a circular opening at the top end is formed on the upper surface side of the frame 16, and a disk-shaped porous plate 18 made of ceramics or the like is fixed in this recess. The upper surface of the porous plate 18 is configured in a shape corresponding to the side of a cone whose center protrudes slightly beyond the outer edge, and the workpiece or dressing tool 2 is placed on this upper surface.

[0034] The lower surface side of the porous plate 18 is connected to a suction source (not shown) such as an ejector via a flow path (not shown) and a valve (not shown) provided inside the frame 16. Therefore, when the suction source is operated with the valve open, the workpiece or the dressing tool 2 placed on the upper surface of the porous plate 18 is sucked by the chuck table 14.

[0035] Furthermore, the chuck table 14 is connected to a horizontal movement mechanism (not shown). The horizontal movement mechanism includes, for example, a ball screw and a motor. When the horizontal movement mechanism operates, the chuck table 14 moves in the horizontal direction.

[0036] The chuck table 14 is connected to a rotation mechanism (not shown). The rotation mechanism includes, for example, a spindle and a motor. When the rotation mechanism operates, the chuck table 14 rotates in the direction of arrow a shown in FIG. 2 around a rotation axis that passes through the center of the holding surface and is aligned vertically or slightly inclined relative to the vertical.

[0037] A grinding unit 20 is provided above the chuck table 14. The grinding unit 20 has a spindle 22 whose upper end is connected to a rotation drive source such as a motor. A disk-shaped wheel mount 24 is fixed to the lower end of the spindle 22.

[0038] The wheel mount 24 is provided with a plurality of openings (not shown) that penetrate the wheel mount 24 in the thickness direction. The plurality of openings are arranged at approximately equal intervals along the circumferential direction of the wheel mount 24. Furthermore, a bolt 26 is inserted into each of the plurality of openings.

[0039] The grinding wheel 28 is attached to the lower part of the wheel mount 24. Specifically, the grinding wheel 28 has an annular base 30. A plurality of female threads (not shown) are provided on the upper part of the base 30, and the grinding wheel 28 is attached to the lower part of the wheel mount 24 by screwing the lower end of the bolt 26 into each female thread.

[0040] In addition, a plurality of grinding wheels 32 are fixed to the lower end of the base 30 and are arranged at approximately equal intervals along the circumferential direction of the base 30. The lower surfaces of the grinding wheels 32 are arranged at approximately the same height, and these lower surfaces become the grinding surfaces of the grinding unit 20.

[0041] Furthermore, the spindle 22 is connected to a vertical movement mechanism (not shown). The vertical movement mechanism includes, for example, a ball screw and a motor. When the vertical movement mechanism operates, the spindle 22, the wheel mount 24, and the grinding wheel 28 move in the vertical direction.

[0042] In addition, the spindle 22 is connected to a rotary drive source (not shown) such as a motor. When the rotary drive source operates, the spindle 22 rotates in the direction of arrow b shown in FIG. 2 around a rotation axis that is a straight line passing through the center of the spindle 22 along the vertical direction.

[0043] The dressing of the grinding wheel 32 in the grinding device 12 is performed, for example, in the following order: First, an operator visually checks the dressing tool 2 to ascertain the thickness of the dressing tool 2.

[0044] For example, as shown in Figure 3, if 9 of the 30 grooves 8 on the upper surface of the dressing board 4 cannot be seen and 21 grooves 8 can be seen, the operator can understand that the thickness of the dressing tool 2 is greater than 1800 μm and less than 1830 μm.

[0045] Next, with the chuck table 14 and the grinding unit 20 spaced apart both horizontally and vertically, the dressing tool 2 is placed on the holding surface of the chuck table 14 with the dressing board 4 facing upward.

[0046] Next, the suction mechanism operates so that the dressing tool 2 is sucked and held on the chuck table 14. Next, the horizontal movement mechanism moves the chuck table 14 so that the rotation axis of the chuck table 14 overlaps with the annular area in which the multiple grinding wheels 32 are arranged.

[0047] A rotation mechanism then rotates the chuck table 14 and a motor connected to the upper end of the spindle 22 rotates the spindle 22, the wheel mount 24 and the grinding wheel .

[0048] Next, the vertical movement mechanism lowers the spindle 22, the wheel mount 24 and the grinding wheel 28 to a position where the grinding wheel 32 can be appropriately dressed, taking into account the thickness of the dressing tool 2. In this way, the grinding wheel 32 is dressed.

[0049] As described above, in the dressing tool 2, a plurality of grooves 8 each having a different depth are formed on the upper surface side of the dressing board 4. As a result, when the upper surface side of the dressing board 4 is scraped away by dressing with the grinding wheel 32 and the thickness of the dressing board 4 is reduced, the shallow grooves (groove 8a having a depth of 30 μm, etc.) are lost and the number of the plurality of grooves 8 formed on the upper surface side of the dressing board 4 is reduced.

[0050] Therefore, in the dressing tool 2, by visually checking the upper surface side of the dressing board 4 and recognizing the number of the remaining grooves 8, the thickness of the dressing tool 2 can be grasped without actually measuring the thickness of the dressing tool 2. In other words, the dressing of the grinding wheel 32 can be simplified.

[0051] Furthermore, in the dressing tool 2, the upper surface of the support plate 6 includes a plurality of locations 10 where information regarding the depth of the plurality of grooves 8 (the distance between the bottom surfaces of the plurality of grooves 8 and the lower surface of the support plate 6) is displayed in a visually recognizable manner. This allows the thickness of the dressing tool 2 to be easily grasped.

[0052] Note that the dressing tool 2 is one aspect of the present invention, and the dressing tool of the present invention is not limited to the dressing tool 2. For example, the support plate 6 does not need to include the multiple locations 10. That is, the support plate 6 does not need to display information regarding the depths of the multiple grooves 8 in a visible manner.

[0053] In addition, the multiple grooves 8 do not have to extend along the radial direction of the dressing board 4, and for example, the multiple grooves 8 may all be formed to be parallel. In addition, the thickness of the dressing board 4 is not limited to 1100 μm, and the thickness of the support plate 6 is not limited to 1000 μm.

[0054] In addition, the number of the multiple grooves 8 formed on the upper surface side of the dressing board 4 is not limited to 30. In addition, the difference in depth between a pair of adjacent grooves 8 (excluding adjacent grooves 8a and 8b) is not limited to 30 μm.

[0055] Furthermore, the information regarding the depth of each of the plurality of grooves 8 indicated at the plurality of locations 10 on the upper surface of the support plate 6 is not limited to the distance between the bottom surface of the groove 8 and the lower surface of the support plate 6. For example, the depth of each of the plurality of grooves 8 may be indicated at the plurality of locations 10.

[0056] In addition, the structures and methods according to the above-described embodiments and modifications can be modified as appropriate without departing from the scope of the present invention. [Explanation of symbols]

[0057] 2: Dressing tool 4: Dressing board 6: Support plate 8(8a,8b,8c,8d): Groove 10(10a, 10b): Location 12: Grinding device 14: Chuck table 16:Frame body 18:Porous plate 20: Grinding unit 22: Spindle 24: Wheel mount 26: Bolt 28: Grinding wheel 30: Foundation 32: Grinding wheel

Claims

[Claim 1] A dressing board for dressing a grinding wheel; A support plate having an upper surface on which the dressing board is fixed, A plurality of grooves having different depths are formed on the upper surface of the dressing board, the upper surface of the support plate includes a plurality of locations at which information regarding the depth of each of the plurality of grooves is visibly indicated; A dressing tool, characterized in that each of the plurality of locations indicates information regarding the depth of a nearest adjacent one of the plurality of grooves.

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