Block gauge

Abstract

To reduce staining of a grindstone caused by a block gauge when a reference position is grasped.SOLUTION: A block gauge is used in a grinding device in order to set a reference position on the upper surface of a chuck table on which a workpiece is sucked and held with respect to a grindstone of a grinding wheel for grinding the workpiece, and comprises a body having a bond material of a resin bond or a vitrified bond. The body has a mounting surface placed on the upper surfacer of the chuck table during use, and a top surface positioned on a side opposite to the mounting surface in the thickness direction of the body.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a block gauge used in a grinding machine to set a reference position of the upper surface of a chuck table that holds a workpiece by suction relative to the grinding stone of a grinding wheel that grinds the workpiece. [Background technology]

[0002] Semiconductor device chips are mounted on electronic devices such as mobile phones. In the manufacturing process of semiconductor device chips, after forming multiple devices on the front side of a wafer made of a semiconductor such as silicon, the back side of the wafer is sometimes ground using a grinding machine to thin the wafer to a predetermined thickness.

[0003] The grinding device includes a disk-shaped chuck table having a holding surface for holding a wafer by suction. The chuck table is rotatable around a predetermined rotation axis by a rotary drive source such as a motor. A grinding unit is provided above the chuck table.

[0004] The grinding unit has a cylindrical spindle arranged substantially parallel to the Z-axis direction (e.g., vertical direction). An annular grinding wheel is attached to the lower end of the spindle. The grinding wheel has an annular base, and a plurality of block-shaped grinding stones are arranged at substantially equal intervals on the bottom surface of the base.

[0005] When grinding a wafer, the chuck table holding the wafer by suction is rotated around a predetermined rotation axis, and the spindle is also rotated. The grinding unit is then fed downward for grinding. The bottom side of the grinding stone, which rotates together with the grinding wheel, comes into contact with the wafer, grinding the wafer.

[0006] Prior to grinding the wafer, a reference position (also called the origin position) in the Z-axis direction is set in the grinding device, where the holding surface and the bottom surface of the grinding wheel come into contact. By setting the reference position, the grinding unit can be lowered at a relatively high grinding feed rate to a position slightly higher than the reference position, allowing for efficient grinding.

[0007] A block gauge is used to set the reference position (see, for example, Patent Document 1). For example, the height position of the grinding unit when the top surface of the block gauge placed on the holding surface comes into contact with the bottom surface of the grinding wheel is set in the grinding device as the reference position of the grinding unit. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-253837 Summary of the Invention [Problem to be solved by the invention]

[0009] However, when determining the reference position, the gauge block comes into contact with the grinding wheel, which can contaminate the grinding wheel with the material that makes up the gauge block. For example, gauge block is usually made of stainless steel.

[0010] Stainless steel contains metal elements such as nickel (Ni), manganese (Mn), molybdenum (Mo), and copper (Cu) in addition to iron (Fe) and chromium (Cr), so there is a possibility that the grinding wheel will be contaminated with the material that makes up the block gauge upon contact.

[0011] The present invention has been made in view of the above problems, and has as its object to reduce contamination of a grinding wheel caused by a block gauge when determining a reference position. [Means for solving the problem]

[0012] According to one aspect of the present invention, there is provided a block gauge used in a grinding machine to set a reference position of an upper surface of a chuck table that holds a workpiece by suction relative to a grinding stone of a grinding wheel that grinds the workpiece, the block gauge being made of a resin bond or a vitrified bond. and a filler of a non-metallic material. The main body has a mounting surface that is placed on the upper surface of the chuck table during use, and a top surface that is located on the opposite side of the mounting surface in the thickness direction of the main body. The top surface includes a first surface and a second surface higher than the first surface, and a sidewall of a step portion located at the boundary between the first surface and the second surface has a curved surface that is perpendicular to the first surface and has an arc shape when the top surface is viewed from above, and the bond material and the filler are exposed on the top surface of the main body and the sidewall of the step portion, and a single metal, an alloy, and only a single type of ceramic including a metal oxide are not exposed. Gauge blocks are provided. [Effects of the Invention]

[0015] A block gauge according to one aspect of the present invention includes a body having a resin-bonded or vitrified-bonded bond material. Therefore, when the grinding wheel has a resin-bonded bond material, a block gauge having a resin-bonded bond material for the body is used, and when the grinding wheel has a vitrified-bonded bond material, a block gauge having a vitrified-bonded bond material for the body is used. This prevents the grinding wheel from being contaminated by the bond material of the block gauge even when the grinding wheel and the block gauge come into contact with each other. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. [Figure 2] FIG. 2 is a partial cross-sectional side view of the grinding device. [Figure 3] 10A and 10B are diagrams showing how the thick portion is brought closer to the grinding wheel on the holding surface. [Figure 4] FIG. 10 is a diagram showing how a thin portion is disposed between the holding surface and the bottom surface of the grinding wheel. [Figure 5] FIG. 10 is a perspective view showing a state in which the thin portion is sandwiched between the bottom surface of the grinding wheel and the holding surface. [Figure 6] FIG. 10 is a top view showing the thin portion sandwiched between the bottom surface of the grinding wheel and the holding surface. [Figure 7]FIG. 7(A) is a perspective view of a block gauge according to the second embodiment, and FIG. 7(B) is a top view of the block gauge according to the second embodiment. [Figure 8] FIG. 8(A) is a perspective view of a block gauge according to the third embodiment, and FIG. 8(B) is a top view of the block gauge according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0017] An embodiment of the present invention will be described with reference to the accompanying drawings. Fig. 1 is a perspective view of a block gauge 2 according to a first embodiment. The block gauge 2 of this embodiment has a main body 4 having a resin bond or a vitrified bond.

[0018] In particular, the bond material of the main body 4 is selected to be of the same quality as the bond material of the grinding wheel 52 described below. For example, if the bond material of the grinding wheel 52 is a resin bond, the main body 4 having a resin bond of the same quality is selected.

[0019] In this specification, the term "same resin bond" means, for example, that both resin bonds are made of thermosetting resin. Alternatively, both resin bonds may be made of the same type and type of thermosetting resin. Thermosetting resins include phenolic resins and epoxy resins.

[0020] Furthermore, phenolic resins include novolac types, resonal types, etc., and epoxy resins include bisphenol A types, bisphenol F types, novolac types, aliphatic types, glycidylamine types, etc.

[0021] For example, when the bond materials of the grinding wheel 52 and the main body 4 are both novolac type phenol resin or both bisphenol A type epoxy resin, they are the same type and kind of resin.

[0022] When the bond material of the grinding wheel 52 is a vitrified bond, a body 4 having a vitrified bond of the same quality is selected. The main components of the vitrified bond are silicon oxide (e.g., SiO2), aluminum oxide (e.g., Al2O3), boron oxide (e.g., B2O3), etc., which are contained in raw materials such as clay, feldspar, and glass.

[0023] In this specification, "vitrified bonds are of the same quality" means that the main components of the vitrified bonds are the same. "Vitrified bonds are the same" means that the main components of the vitrified bonds are the same as long as the multiple main components that make up the vitrified bonds are the same, and the proportions of the main components do not have to be completely the same.

[0024] For example, if the same type of raw material is used in approximately the same ratio when manufacturing the bond material of the grinding wheel 52 and the bond material of the block gauge 2, then the grinding wheel 52 and the block gauge 2 can be said to have the same quality vitrified bond.

[0025] When manufacturing the main body 4, first, a bond material and a filler (not shown) made of a non-metallic material are mixed to obtain a mixed material. For example, the volume ratio of the bond material to the filler (bond material:filler) is set to 5:5 to 2:8.

[0026] The filler in the main body 4 is mixed into the bond material, for example, to adjust the hardness of the bond material. The filler in the main body 4 has, for example, the same material, approximately the same size, and approximately the same shape as the filler contained in the grinding wheel 52. However, the volume ratio of the bond material and the filler in the main body 4 does not necessarily have to be the same as that of the grinding wheel 52.

[0027] In the case of resin bonding, the above-mentioned thermosetting resins such as phenolic resins and epoxy resins are used as the bonding material, while in the case of vitrified bonding, the above-mentioned clay, feldspar, glass, etc. are used as the bonding material.

[0028] After mixing the bonding material and filler, the mixed material is placed in a predetermined mold and compression molded to obtain a rectangular plate having a predetermined thickness (e.g., 5.5 mm to 6.0 mm), width, and length.

[0029] During compression molding, the mixed material having a resin bond is heated to a predetermined temperature of 100° C. or more and 200° C. or less, but the mixed material having a vitrified bond is heated appropriately as needed.

[0030] The compression-molded rectangular plate is then fired. For example, a rectangular plate with a resin bond is fired at about 200°C, and a rectangular plate with a vitrified bond is fired at about 1200°C. The top surface of the fired rectangular plate is then scraped to shape it, thereby obtaining the main body 4.

[0031] Furthermore, resin bonds are less susceptible to thermal shrinkage during firing than vitrified bonds. Therefore, the dimensions of resin bonds after firing are closer to the dimensions at the time of compression molding than vitrified bonds, which has the advantage of making it easier to adjust the body 4 to the desired dimensions.

[0032] The main body 4 is manufactured through compression molding, firing and shaping and has a thin portion 4a and a thick portion 4b. The bottom surfaces (mounting surfaces) 6 of the thin portion 4a and the thick portion 4b are substantially flush with each other.

[0033] The top surface 10, located on the opposite side of the bottom surface 6 in the thickness direction 8 of the main body 4, includes a top surface (first surface) 10a of the thin portion 4a and a top surface (second surface) 10b of the thick portion 4b. The top surfaces 10a and 10b are substantially parallel to the bottom surface 6, but the top surface 10b is higher than the top surface 10a.

[0034] For example, the thickness 8b of the thick portion 4b is 5.02 mm, and the thickness 8a of the thin portion 4a is 5.00 mm. Therefore, at the boundary between the top surface 10b and the top surface 10a, there is a step portion 12 with a step of 0.02 mm (i.e., 20 μm).

[0035] The step portion 12 has a substantially flat sidewall 12a that connects to the top surfaces 10a and 10b. In this embodiment, the sidewall 12a is perpendicular to the top surfaces 10a and 10b. When the top surface 10 is viewed from above, the sidewall 12a of the step portion 12 is perpendicular to the longitudinal direction 14 of the main body portion 4 and is linear and substantially parallel to the width direction 16 of the main body portion 4.

[0036] The length of the main body 4 in the longitudinal direction 14 is, for example, a predetermined value of 50 mm or more and 60 mm or less, and the length of the main body 4 in the width direction 16 is, for example, a predetermined value of 20 mm or more and 30 mm or less.

[0037] The four side surfaces of the main body 4 are substantially flat planes. A first side surface 18a connecting one side of the top surface 10a located opposite the step portion 12 to the bottom surface 6 is a substantially flat rectangle. A second side surface 18b located opposite the first side surface 18a in the longitudinal direction 14 of the main body 4 is also a substantially flat rectangle.

[0038] The second side surface 18b connects one side of the top surface 10b located opposite the step portion 12 to the bottom surface 6. A third side surface 20 extending across the top surfaces 10a and 10b and a fourth side surface 22 located opposite the third side surface 20 in the width direction 16 of the main body 4 are substantially flat.

[0039] The third side surface 20 and the fourth side surface 22 have a pentagonal shape due to the step portion 12. Note that a mark, a protrusion, a recess, or the like may be provided on a part of at least one of the third side surface 20 and the fourth side surface 22 to indicate the approximate position of the thin portion 4 a or the thick portion 4 b.

[0040] Next, a method of using the block gauge 2 will be described. To this end, first, a grinding device 30 for using the block gauge 2 will be described with reference to Fig. 2. Fig. 2 is a partially cross-sectional side view of the grinding device 30 for performing so-called in-feed grinding. Note that the Z-axis direction shown in Fig. 2 is, for example, parallel to the vertical direction.

[0041] The grinding device 30 has a disk-shaped chuck table 32. The chuck table 32 has a disk-shaped frame 34 made of non-porous ceramics. A disk-shaped recess is formed in the upper part of the frame 34, and a disk-shaped porous plate 36 made of porous ceramics is fixed in this recess.

[0042] The upper surfaces of the frame 34 and the porous plate 36 are substantially flush. A predetermined flow path (not shown) is formed in the frame 34. One end of this flow path is connected to a suction source (not shown), such as an ejector, via an electromagnetic valve (not shown). When negative pressure is generated by the suction source, the negative pressure is transmitted to the porous plate 36.

[0043] Therefore, the upper surfaces of the frame 34 and the porous plate 36 function as a holding surface (upper surface) 32a that suction-holds the wafer (workpiece) 11. The holding surface 32a has a conical shape with the center slightly protruding compared to the outer periphery. However, since the amount of protrusion of the holding surface 32a is very small compared to the outer diameter of the holding surface 32a, the holding surface 32a is shown as substantially flat in FIG. 2.

[0044] In addition, the chuck table 32 is slightly tilted by a tilt adjustment mechanism (not shown) so that a portion of the holding surface 32a is approximately parallel to the bottom surface 52a (described later) of the grinding wheel 52, but for convenience, in Figure 2, the holding surface 32a is shown as being perpendicular to the Z-axis direction.

[0045] A shaft 38 is connected to the center of the bottom surface of the chuck table 32. The shaft 38 is indicated by a dashed line in Fig. 2. A drive source (not shown), such as a motor, is disposed below the chuck table 32.

[0046] The chuck table 32 rotates around the shaft 38 while being slightly tilted by the power transmitted from the drive source. A grinding unit 40 is provided above the chuck table 32. The grinding unit 40 has a spindle housing (not shown) whose longitudinal portion is arranged along the Z-axis direction.

[0047] A ball screw type Z-axis direction movement mechanism (not shown) that moves the grinding unit 40 along the Z-axis direction is connected to the spindle housing. The spindle housing rotatably accommodates a portion of the cylindrical spindle 42.

[0048] A rotation drive source (not shown), such as a motor, is provided at the upper end of the spindle 42. The upper surface of a disk-shaped mount 44 is fixed to the lower end of the spindle 42. An annular grinding wheel 46 is attached to the lower surface of the mount 44.

[0049] The grinding wheel 46 has an annular base 48 made of metal such as an aluminum alloy. The base 48 is fixed to the mount 44 with fixing members 50 such as screws. A plurality of grinding stones 52 are arranged at approximately equal intervals on the underside of the base 48 along the circumferential direction of the base 48 (see FIG. 6).

[0050] When the spindle 42 is rotated, a circular grinding surface is formed by the locus of the bottom surface 52a of each grinding wheel 52. The grinding wheel 52 has a generally block shape. The grinding wheel 52 includes abrasive grains, a bond material, and a filler.

[0051] The abrasive grains are so-called superabrasive grains such as diamond or cBN (cubic boron nitride). The bond material is a resin bond or a vitrified bond and is used to fix the abrasive grains. The filler is mixed into the bond material, for example, to adjust the hardness of the bond material.

[0052] To manufacture the grinding wheel 52, similar to the manufacturing of the main body 4, a bond material, a filler, and abrasive grains are mixed, compression molded, fired, and then shaped.

[0053] The grinding device 30 is provided with a control unit (not shown) that controls each component of the grinding device 30. The control unit is configured by a computer including, for example, a processor represented by a CPU (Central Processing Unit), a main storage device such as a DRAM (Dynamic Random Access Memory), and an auxiliary storage device such as a flash memory.

[0054] The auxiliary storage device stores software including a predetermined program. The functions of the control unit are realized by operating the processing device and the like in accordance with this software.

[0055] A touch panel (not shown) that functions as a display device and an input device is provided in the grinding device 30. An operator can perform predetermined operations on the control unit via the touch panel.

[0056] When grinding the wafer 11, for example, a resin protective tape (not shown) is attached to the front surface 11a of the wafer 11, and the front surface 11a side is suction-held by the holding surface 32a, and the chuck table 32 is then rotated at a predetermined rotation speed.

[0057] Furthermore, the spindle 42 is rotated, and the grinding unit 40 is lowered (grinding fed) along the Z-axis direction while grinding water (not shown) such as pure water is supplied to the grinding wheel 52. The grinding surface comes into contact with the wafer 11, thereby grinding the back surface 11b side.

[0058] Prior to grinding the wafer 11, the block gauge 2 is used to set a reference position (origin position) in the Z-axis direction of the holding surface 32a relative to the bottom surface 52a of the grinding wheel 52. Next, a method of using the block gauge 2 will be described with reference to FIGS.

[0059] When setting the reference position using the block gauge 2, first, the chuck table 32 and the spindle 42 are stopped and not rotated. Then, the solenoid valve is closed to prevent negative pressure from being transmitted to the holding surface 32a, thereby exposing the holding surface 32a.

[0060] Then, the Z-axis movement mechanism is operated to lower the grinding wheel 46 until the bottom surface 52a of the grinding stone 52 is a predetermined distance from the holding surface 32a (for example, approximately 6 mm, which is larger than the thickness 8b of the thick portion 4b of the block gauge 2).

[0061] Next, the block gauge 2 is placed on the exposed area of ​​the holding surface 32a that does not overlap with the grinding unit 40. At this time, the bottom surface 6 contacts the holding surface 32a, and the top surface 10 is exposed upward. Then, the worker slides the block gauge 2 on the holding surface 32a, bringing the thick portion 4b closer to the outside of the grinding wheel 46.

[0062] When the top surface 10b of the thick portion 4b is located lower than the bottom surface 52a of the grinding wheel 52, the thick portion 4b can advance below the bottom surface 52a. In this case, the block gauge 2 is temporarily moved outward from the area directly below the grinding wheel 46.

[0063] Then, the Z-axis movement mechanism is operated to lower the grinding unit 40 by a small amount. Then, in the same manner, the thick portion 4b is brought closer to the grinding wheel 46. If the top surface 10b of the thick portion 4b is positioned higher than the bottom surface 52a of the grinding wheel 52 as a result of the grinding unit 40 being processed and fed by a small amount, the thick portion 4b cannot advance below the bottom surface 52a (see FIG. 3).

[0064] 3 is a diagram showing how the thick portion 4b is brought closer to the grinding wheel 46 on the holding surface 32a. If the thick portion 4b does not fit under the bottom surface 52a, the worker turns the block gauge 2 180 degrees to bring the thin portion 4a closer to the outside of the grinding wheel 46.

[0065] When the distance from the holding surface 32a to the bottom surface 52a is equal to or greater than the thickness 8a of the thin portion 4a, the thin portion 4a can move below the bottom surface 52a, as shown in Fig. 4. In this way, the height position of the grinding unit 40 is found when the thick portion 4b cannot fit between the bottom surface 52a and the holding surface 32a, but the thin portion 4a can fit between them.

[0066] Fig. 4 is a diagram showing how the thin portion 4a is arranged between the holding surface 32a and the bottom surface 52a of the grinding wheel 52. Fig. 5 is a perspective view showing how the thin portion 4a is sandwiched between the bottom surface 52a of the grinding wheel 52 and the holding surface 32a, and Fig. 6 is a top view showing how the thin portion 4a is sandwiched between the bottom surface 52a of the grinding wheel 52 and the holding surface 32a.

[0067] 6, the grinding wheels 52 that come into contact with the wafer 11 when grinding the wafer 11 and some of the grinding wheels 52 are shown in white. The areas of the holding surface 32a that are located directly below the white grinding wheels 52 are approximately parallel to the bottom surface 52a.

[0068] The operator sets in the control unit the height position of the grinding unit 40 when the thick portion 4b does not fit between the bottom surface 52a and the holding surface 32a but the thin portion 4a does fit as the reference height 54 (see Figure 4) of the grinding wheel 46 relative to the holding surface 32a.

[0069] In this embodiment, the bond material of the body 4 of the block gauge 2 is resin bond or vitrified bond. When the bond material of the grinding wheel 52 is resin bond, a block gauge 2 whose bond material of the body 4 is resin bond is used.

[0070] Furthermore, when the bond material of the grinding wheel 52 is a vitrified bond, a block gauge 2 whose bond material of the main body 4 is a vitrified bond is used. This prevents the grinding wheel 52 from being contaminated by the bond material of the block gauge 2 even when the grinding wheel 52 and the block gauge 2 come into contact with each other. Therefore, contamination of the grinding wheel 52 by the block gauge 2 can be reduced.

[0071] A typical block gauge is made of stainless steel. However, by using the block gauge 2 of this embodiment, it is possible to prevent metal components of the stainless steel from adhering to the bottom surface 52a of the grinding wheel 52, and further to prevent the wafer 11 from being contaminated by these metal components during grinding.

[0072] Incidentally, some commercially available block gauges are made of a single type of ceramic, such as alumina (aluminum oxide: Al2O3) or zirconia (zirconium dioxide: Zr2O).

[0073] However, gauge blocks made of a single type of ceramic, such as aluminum oxide, have a different ratio of major components than the grinding wheel 52. Also, gauge blocks made of a single type of ceramic, such as zirconium dioxide, contain components that are not contained in the grinding wheel 52.

[0074] Therefore, although metal contamination can be avoided by using such a block gauge, there is a possibility that deposits having major components in different ratios from those of the grinding wheel 52 or deposits of components not contained in the grinding wheel 52 may adhere to the grinding wheel 52. Furthermore, there is a possibility that these deposits may adhere to the wafer 11 during grinding.

[0075] In contrast, the bond material of the main body 4 in this embodiment is a resin bond or a vitrified bond, which is of the same quality as the bond material of the grinding wheel 52, so even if part of the main body 4 is scraped off and adheres to the grinding wheel 52, it is unlikely to be a problem.

[0076] Next, a second embodiment will be described with reference to Fig. 7(A) and Fig. 7(B). Fig. 7(A) is a perspective view of a block gauge 62 in the second embodiment, and Fig. 7(B) is a top view of the block gauge 62 in the second embodiment.

[0077] The block gauge 62 differs from the first embodiment in the shape of the step portion 64. The side wall 64a of the step portion 64 is perpendicular to the top surfaces 10a and 10b, similar to the side wall 12a of the step portion 12. Furthermore, the side wall 64a is an arc-shaped curved surface when the top surface 10 is viewed from above.

[0078] In particular, the side wall 64a has a curved shape corresponding to the outer surface 52b of the grinding wheel 52. The curvature of the side wall 64a is, for example, substantially the same as the curvature of the outer surface 52b. When the top surface 10 is viewed from above, the side wall 64a has a convex shape in the direction from the top surface 10a of the thin portion 4a to the top surface 10b of the thick portion 4b.

[0079] Therefore, the side wall 64a and the outer surface 52b can be in surface contact with each other when using the block gauge 62. This allows stress to be distributed to the outer surface 52b more effectively than in the first embodiment, when the step portion 12 is in contact with the outer surface 52b, and further leads to suppression of chipping of the main body 4 and the grinding wheel 52.

[0080] Next, a third embodiment will be described with reference to Fig. 8(A) and Fig. 8(B). Fig. 8(A) is a perspective view of a block gauge 72 in the third embodiment, and Fig. 8(B) is a top view of the block gauge 72 in the third embodiment.

[0081] The side wall 74a is perpendicular to the top surfaces 10a and 10b, similar to the side wall 64a, and the side wall 74a of the step portion 74 is an arc-shaped curved surface when the top surface 10 is viewed from above.

[0082] The curvature of the side wall 74a is, for example, approximately the same as the curvature of the inner surface of the grinding stone 52 located opposite the outer surface 52b in the radial direction of the grinding wheel 46. However, the protruding direction of the side wall 74a is different from that of the side wall 64a.

[0083] When top surface 10 is viewed from above, side wall 74a has a convex shape in the direction from top surface 10b of thick portion 4b to top surface 10a of thin portion 4a. In other words, when top surface 10 is viewed from above, side wall 74a has a concave shape in the direction from top surface 10a of thin portion 4a to top surface 10b of thick portion 4b.

[0084] When using the block gauge 72, the contact area between the side wall 74a and the outer surface 52b can be reduced compared to the contact area between the side wall 64a and the outer surface 52b. Therefore, even if the outer surface 52b is scratched by the block gauge 72, the area of ​​the scratch can be narrowed.

[0085] In addition, the structures, methods, etc. according to the above-described embodiments can be modified as appropriate without departing from the scope of the present invention. For example, the block gauges 2, 62, and 72 can be used in grinding devices that perform creep feed grinding as well as in infeed grinding. [Explanation of symbols]

[0086] 2, 62, 72: Block gauge 4: Main body, 4a: Thin part, 4b: Thick part, 6: Bottom surface (mounting surface) 8: thickness direction, 8a, 8b: thickness 10: Top surface, 10a: Top surface (first surface), 10b: Top surface (second surface) 11: Wafer (workpiece), 11a: Front side, 11b: Back side 12, 64, 74: step portion, 12a, 64a, 74a: side wall 14: Longitudinal direction, 16: Width direction 18a: 1st side, 18b: 2nd side, 20: 3rd side, 22: 4th side 30: grinding device, 32: chuck table, 32a: holding surface (upper surface) 34: Frame body, 36: Porous plate, 38: Shaft part 40: Grinding unit, 42: Spindle, 44: Mount 46: Grinding wheel, 48: Base, 50: Fixing member 52: Grinding wheel, 52a: bottom surface, 52b: outer surface, 54: reference height

Claims

[Claim 1] A block gauge used in a grinding device to set a reference position of an upper surface of a chuck table that holds a workpiece by suction with respect to a grinding stone of a grinding wheel that grinds the workpiece, A body portion having a resin bond or a vitrified bond and a non-metallic filler, The main body portion is a mounting surface that is placed on the upper surface of the chuck table during use; a top surface located on the opposite side of the mounting surface in a thickness direction of the main body; and The top surface includes a first surface and a second surface higher than the first surface; a side wall of a step portion located at a boundary between the first surface and the second surface has a curved surface that is perpendicular to the first surface and has an arc shape when the top surface is viewed from above; The block gauge is characterized in that the bond material and the filler are exposed on the top surface of the main body and the side wall of the step portion, and that no elemental metal, no alloy, or only a single type of ceramic including a metal oxide is exposed.

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