JP2020172009A - Dressing tool - Google Patents

Abstract

To provide a dressing tool that can appropriately determine whether or not a dressing board is abraded to a thickness in which the board can no longer be used.SOLUTION: A dressing tool, which dresses a plurality of grinding stones arranged annularly at one surface side pf a grinding wheel, comprises a dressing part for dressing the grinding stones and a support part for supporting a rear side of the dressing part. At the rear side of the dressing part is formed a recessed part not reaching a surface positioned at the opposite side of the rear side of the dressing part and having a depth corresponding to a thickness in which the dressing part can no longer be used.SELECTED DRAWING: Figure 1

Description

The present invention relates to a dressing tool used to dress a grinding wheel grindstone.

As a processing method for dividing a wafer in which a plurality of devices are formed on the front surface side into chips corresponding to each device, for example, a method of grinding the back surface side of the wafer and then cutting the wafer with a cutting blade to divide the wafer. There is.

Grinding of a wafer is performed, for example, by a grinding device equipped with a grinding wheel equipped with a grinding wheel (grinding wheel) for grinding. The wafer is ground by holding the wafer on the holding table of the grinding device and pressing the rotated grinding wheel against the surface to be processed of the wafer (see, for example, Patent Document 1).

The above-mentioned grinding wheel is formed by, for example, mixing abrasive grains such as diamond and cBN (cubic boron nitride) with a binder such as vitrify and resinoid and sintering the grinding wheel. When a wafer is ground with this grinding wheel, a large number of abrasive grains protruding from the surface (that is, the grinding surface) of the grinding wheel act as cutting edges, and the work surface of the wafer is scraped off.

As the grinding progresses, the grinding wheel also wears, and new abrasive grains appear one after another on the surface of the grinding wheel that comes into contact with the work surface of the wafer. By this action (called a self-generated blade action or the like), deterioration of grinding performance due to spillage, clogging, clogging, etc. of abrasive grains is suppressed, and good cutting work is realized.

By the way, in the unused grinding wheel, the abrasive grains do not properly protrude from the surface of the grinding wheel, and the height of the grinding surface of the grinding wheel also varies. Therefore, before grinding the wafer, the grinding wheel is sharpened with a dressing board (also called a dresser board) to partially remove the binder covering the abrasive grains and appropriately remove the abrasive grains from the surface of the grinding wheel. A dressing step is performed (see, for example, Patent Document 2).

The dressing board is formed, for example, with a thickness of about 1 mm to 5 mm, and a resin support plate is fixed to the back surface side thereof via an adhesive or the like. This dressing board wears with the sharpening process of the grinding wheel and is replaced when it becomes thin to a predetermined thickness. For example, the time to replace the dressing board is determined by visually observing the thickness of the dressing board.

Japanese Unexamined Patent Publication No. 2000-288881 JP-A-2009-142906

However, it is not always possible to properly determine when to replace the dressing board by the above-mentioned visual method or the like. If the grinding wheel grinds the support plate using the dressing board worn to the thickness limit of use without replacing it, the grinding wheel may be damaged.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a dressing tool capable of appropriately determining whether or not a dressing board has been worn to a thickness limit of use.

According to one aspect of the present invention, a dressing tool for dressing a plurality of grinding wheels arranged in an annular shape on one surface side of a grinding wheel, the dressing portion for dressing the grinding wheels and the back surface side of the dressing portion. A support portion for supporting is provided, and the back surface side of the dressing portion does not reach the surface surface of the dressing portion opposite to the back surface, and corresponds to the thickness of the use limit of the dressing portion. A dressing tool is provided that is provided with a recess of a depth to be provided.

Preferably, the recess of the dressing portion is provided linearly when the dressing portion is viewed from the back surface side. Further, preferably, the recess of the dressing portion is provided on the outer peripheral side of the center of the dressing portion when the dressing portion is viewed from the back surface side.

Further, preferably, the recess of the dressing portion is provided in an annular shape when the dressing portion is viewed from the back surface side. Further, preferably, the recess of the dressing portion includes a first recess having a first depth and a second recess having a second depth deeper than the first depth. Further, preferably, the first recess and the second recess overlap in the depth direction of the recess.

The dressing tool according to one aspect of the present invention includes a dressing portion for dressing the grinding wheel and a support portion for supporting the back surface side of the dressing portion. On the back surface side of the dressing portion, a recess is provided that does not reach the surface of the dressing portion and has a depth corresponding to the thickness of the use limit of the dressing portion.

When the dressing board is worn along with the sharpening treatment of the grinding wheel and becomes thin to a predetermined thickness, a recess appears on the surface side of the dressing portion, so that it can be visually determined that the dressing portion has been worn to the thickness limit of use. Therefore, the timing when the dressing tool reaches the usage limit can be appropriately determined.

FIG. 1A is a perspective view of the dressing tool according to the first embodiment, and FIG. 1B is a sectional view taken along the line AA of the dressing tool according to the first embodiment. It is a side view which shows the use state of a dressing tool. It is a cross-sectional view of AA of the dressing tool which reached the use limit. FIG. 4A is a perspective view of the dressing tool according to the second embodiment, and FIG. 4B is a sectional view taken along line BB of the dressing tool according to the second embodiment. FIG. 5A is a perspective view of the dressing tool according to the third embodiment, and FIG. 5B is a sectional view taken along line CC of the dressing tool according to the third embodiment. FIG. 6A is a perspective view of the dressing tool according to the fourth embodiment, and FIG. 6B is a cross-sectional view taken along the line DD of the dressing tool according to the fourth embodiment. FIG. 7A is a sectional view taken along the line AA of the dressing tool according to the first modification of the first embodiment, and FIG. 7B is a sectional view taken along line B-A of the dressing tool according to the first modification of the second embodiment. B cross-sectional view, FIG. 7 (C) is a CC cross-sectional view of the dressing tool according to the first modification of the third embodiment, and FIG. 7 (D) is a first modification of the fourth embodiment. It is a DD sectional view of the dressing tool. FIG. 8A is a sectional view taken along the line AA of the dressing tool according to the second modification of the first embodiment, and FIG. 8B is a cross-sectional view taken along the line B-A of the dressing tool according to the second modification of the second embodiment. B cross-sectional view, FIG. 8C is a CC cross-sectional view of the dressing tool according to the second modification of the third embodiment, and FIG. 8D is a second modification of the fourth embodiment. It is a DD sectional view of the dressing tool.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1A is a perspective view of the dressing tool 2 according to the first embodiment, and FIG. 1B is a sectional view taken along the line AA of the dressing tool 2 according to the first embodiment.

As shown in FIG. 1A, the dressing tool 2 according to the first embodiment has a dressing board (dressing portion) 4 formed in a flat disk shape. The shape of the dressing board 4 is not limited to the disk shape. The shape of the dressing board 4 may be a rectangular plate.

The front surface 6a of the support plate (support portion) 6 that supports the dressing board 4 is adhered to the back surface 4b of the dressing board 4. The support plate 6 is formed in a disk shape having a diameter larger than that of the dressing board 4 so that the entire dressing board 4 can be supported. The support plate 6 is made of, for example, a resin.

The dressing board 4 is formed by using, for example, a mixed material in which abrasive grains such as white random (WA) and green carbon (GC) are mixed with a binder such as vitrify and resinoid. However, the binder and abrasive grains constituting the dressing board 4 are changed according to the configuration of the grinding wheel 26 and the like.

The dressing board 4 has a thickness of, for example, 3 mm to 5 mm. A recess 8 is provided on the back surface 4b side of the dressing board 4. The recess 8 is a hole formed of a substantially columnar space, and is provided at a substantially central portion on the back surface 4b side of the dressing board 4 as shown in the AA cross section of FIG. 1 (B).

The AA cross section of FIG. 1B is a plane that passes through the center of the circular surface 4a of the dressing board 4 (that is, the surface located on the opposite side of the back surface 4b) and is perpendicular to the surface 4a. It is a cut surface which cut 4 and the support plate 6.

The recess 8 is formed to a predetermined depth that does not reach the front surface 4a from the back surface 4b. The depth of the recess 8 is such that when the dressing board 4 is worn to the thickness of the limit of use, the recess 8 appears on the surface 4a side of the dressing board 4 (that is, corresponding to the thickness of the limit of use of the dressing board 4). ) It has been adjusted.

For example, when the thickness of the dressing board 4 is set to 400 μm, the depth of the recess 8 is adjusted to a depth of 400 μm from the back surface 4b. However, the thickness of the dressing board 4's use limit and the depth of the recess 8 are not limited to 400 μm, and can be set to various values.

When the dressing board 4 is worn together with the sharpening treatment of the grinding wheel 26 and becomes thin to a predetermined thickness, a recess 8 appears on the surface of the dressing board 4. Therefore, since the operator can visually determine whether or not the dressing board 4 has been worn to the thickness of the use limit, the timing at which the dressing tool 2 reaches the use limit can be appropriately determined.

The dressing board 4 described above can be manufactured by a manufacturing method similar to the conventional dressing board manufacturing method. For example, first, the above-mentioned mixed material is molded to form a flat disk-shaped molded product. However, at the time of molding, a hole corresponding to the recess 8 is formed in the central portion of one circular surface of the molded body. After that, the dressing board 4 having the recess 8 can be manufactured by sintering the molded body.

It should be noted that the hole corresponding to the recess 8 may be formed in the sintered body without forming the hole corresponding to the recess 8 in the molded body. For example, after molding the mixed material into a flat disk shape, the molded body is sintered. After that, the disk-shaped sintered body is cut to form the recess 8. As a result, the dressing board 4 having the recess 8 can be manufactured.

Next, the dressing process of the grinding wheel 26 using the dressing tool 2 of the first embodiment will be described. FIG. 2 is a side view showing a usage state of the dressing tool 2. As shown in FIG. 2, the grinding apparatus 12 used in the dressing step includes a cylindrical spindle housing 16 that rotatably supports the spindle 14.

The spindle housing 16 is attached to a support column (not shown) of the grinding device 12 via a moving mechanism (not shown) and moves in the vertical direction. A wheel mount 20 for mounting the grinding wheel 18 is fixed to the lower end side of the spindle 14.

A rotation mechanism 22 including a motor and the like is connected to the upper end side of the spindle 14. A grinding wheel 18 is mounted on the wheel mount 20, and the grinding wheel 18 rotates by a rotational force transmitted from the rotating mechanism 22.

The grinding wheel 18 includes a cylindrical wheel base 24 made of a metal material such as aluminum or stainless steel. One surface of the wheel base 24 on the opposite side of the wheel mount 20 is formed in an annular shape, and a plurality of grinding wheels 26 are fixed along the circumferential direction of one surface of the annular shape. That is, a plurality of grinding wheels 26 are arranged in an annular shape on one surface side of the wheel base 24.

A holding table 28 is provided below the wheel mount 20. The holding table 28 is connected to a drive mechanism (not shown) such as a motor, and rotates around a rotation axis parallel to the axial direction of the spindle 14.

The surface 28a of the holding table 28 is a holding surface for sucking and holding an workpiece such as a wafer. A negative pressure of a suction source (not shown) such as an ejector acts on the holding surface through a flow path (not shown) formed inside the holding table 28, and a suction force for sucking the workpiece is generated.

With the back surface 6b side of the support plate 6 attracted to the holding table 28, the grinding wheel 18 and the holding table 28 are rotated to lower the spindle housing 16. If the amount of lowering of the spindle housing 16 is adjusted so as to press the grinding wheel 26 against the surface 4a of the dressing board 4, the grinding wheel 26 is dressed by the dressing board 4.

FIG. 3 is a sectional view taken along the line AA of the dressing tool 2 which has reached the usage limit. When the dressing board 4 is worn by the dressing of the grinding wheel 26 described above, the dressing board 4 gradually becomes thinner. When the dressing board 4 is worn to the thickness limit of use, a recess 8 appears on the surface 4a side of the dressing board 4.

As described above, the dressing tool 2 of the first embodiment is provided with a recess 8 having a depth corresponding to the thickness of the use limit of the dressing board 4. Therefore, it can be determined whether or not the dressing board 4 has been worn to the thickness of the use limit based on whether or not the recess 8 appears on the surface 4a side of the dressing board 4.

For example, when identifying whether or not the recess 8 appears on the surface 4a side, the dressing tool 2 is conveyed from the holding table 28 to the cassette (not shown) after the dressing step is completed, so that the operator can use the cassette. Observe the surface 4a side of the stationary dressing board 4 transported to. Thereby, the operator can identify whether or not the recess 8 appears on the surface 4a side.

Further, the operator may observe the surface 4a side of the dressing board 4 in a state where the dressing tool 2 is held by the holding table 28 and is rotating (that is, during the dressing process). In this way, it is possible to identify whether or not the recess 8 appears on the surface 4a side by visually observing the dressing board 4 in the rotating state.

The main body that identifies whether or not the recess 8 appears on the surface 4a side is not necessarily limited to the operator. For example, a determination device including a camera that images the surface 4a side and a determination unit such as a CPU that determines whether or not a recess 8 appears on the surface 4a side from an image captured by the camera has a recess on the surface 4a side. You may automatically identify whether or not 8 appears.

By the way, the shape of the recess 8 can be changed in various ways. The recess 8 of the dressing board 4 of the first embodiment is a substantially columnar hole, but the shape of the recess 8 is not limited to the columnar hole.

FIG. 4A is a perspective view of the dressing tool 2 according to the second embodiment, and FIG. 4B is a sectional view taken along line BB of the dressing tool 2 according to the second embodiment. As shown in FIGS. 4 (A) and 4 (B), a recess 8a is provided on the back surface 4b side of the dressing board 4 of the second embodiment. The recess 8a is a linear groove having a longitudinal portion in the radial direction of the dressing board 4.

More specifically, the recess 8a is formed in a straight line passing through the center О of the circular back surface 4b when the dressing board 4 is viewed from the back surface 4b side, and the length of the recess 8a in the longitudinal direction is circular. It is formed so as to be substantially the same as the diameter of the back surface 4b of the above. However, the recess 8a may be formed in a straight line that does not pass through the center O of the back surface 4b when viewed from the back surface 4b.

The recess 8a is formed to a predetermined depth that does not reach the front surface 4a from the back surface 4b. The depth of the recess 8a is adjusted so that when the dressing board 4 is worn to the thickness of the usage limit, the recess 8a appears on the surface 4a side of the dressing board 4 that comes into contact with the grinding wheel 26.

Therefore, even in the second embodiment, the operator or the like can determine whether or not the dressing board 4 has been worn to the thickness of the use limit based on whether or not the recess 8 appears on the surface 4a side of the dressing board 4. ..

Further, since the recess 8a is formed in a straight line passing through the center O, the recess 8a is visible on the entire surface 4a side when the dressing board 4 is rotating. On the other hand, when the center position of the recess 8 is provided at the center O as in the first embodiment, when the dressing board 4 rotates, the recess 8 is visually recognized as a circular point on the surface 4a.

As described above, in the second embodiment, when the recess 8a appears on the surface 4a side when the dressing board 4 is rotating, the recess 8a can be observed in a wider range than in the first embodiment, so that the recess 8a is formed. Whether or not it appears on the surface 4a side can be more easily identified as compared with the first embodiment.

FIG. 5A is a perspective view of the dressing tool 2 according to the third embodiment, and FIG. 5B is a sectional view taken along line CC of the dressing tool 2 according to the third embodiment. As shown in FIGS. 5A and 5B, a recess 8b is provided on the back surface 4b side of the dressing board 4 of the third embodiment. The recess 8b is a substantially columnar hole provided outside the center О of the circular back surface 4b when the dressing board 4 is viewed from the back surface 4b side.

The center position of the recess 8b of the third embodiment is at a distance of 7r / 8 from the center O (r is the radius of the back surface 4b). The center position of the recess 8b on the back surface 4b may be outside the position at a distance of r / 2 from the center O, and may be at a position at a distance of 3r / 4 from the center O.

The recess 8b is formed to a predetermined depth that does not reach the front surface 4a from the back surface 4b. The depth of the recess 8b is also adjusted so that when the dressing board 4 is worn to the thickness of the use limit, the recess 8b appears on the surface 4a side of the dressing board 4. Therefore, also in the third embodiment, it can be determined whether or not the dressing board 4 has been worn to the thickness of the use limit based on whether or not the recess 8b appears on the surface 4a side of the dressing board 4.

Further, since the center position of the recess 8b is provided outside the center O of the back surface 4b, the recess 8b is visually recognized as an annular locus on the surface 4a side when the dressing board 4 is rotating. On the other hand, when the center position of the recess 8 is provided at the center O as in the first embodiment, when the dressing board 4 rotates, the recess 8 is visually recognized as a circular point on the surface 4a.

As described above, in the third embodiment, when the recess 8b appears on the surface 4a side when the dressing board 4 is rotating, the recess 8b can be observed in a wider range than in the first embodiment, so that the recess 8b is formed. Whether or not it appears on the surface 4a side can be more easily identified as compared with the first embodiment.

6 (A) is a perspective view of the dressing tool 2 according to the fourth embodiment, and FIG. 6 (B) is a DD sectional view of the dressing tool 2 according to the fourth embodiment. As shown in FIGS. 6 (A) and 6 (B), the dressing board 4 of the fourth embodiment has an annular recess 8c having a diameter smaller than the diameter of the dressing board 4.

The recess 8c is an annular groove provided on the outer peripheral side of the circular back surface 4b center О when the dressing board 4 is viewed from the back surface 4b side. The recess 8c is circular when viewed from the back surface 4b side, but it does not necessarily have to be a perfect circle. The recess 8c is also formed to a predetermined depth that does not reach the front surface 4a from the back surface 4b.

The depth of the recess 8c is adjusted so that when the dressing board 4 is worn to the thickness of the use limit, the recess 8c appears on the surface 4a side of the dressing board 4 that comes into contact with the grinding wheel 26. Therefore, also in the fourth embodiment, it can be determined whether or not the dressing board 4 has been worn to the thickness of the use limit based on whether or not the recess 8c appears on the surface 4a side of the dressing board 4.

In the fourth embodiment, since the recess 8c is provided in an annular shape, it is possible to identify whether or not the recess 8c appears on the surface 4a side even if an arbitrary region on the recess 8c in the circumferential direction is partially thinned. it can. In addition, when the recess 8c appears on the surface 4a side when the dressing board 4 is rotating, the recess 8c can be observed in a wider range than that of the first embodiment, so that the recess 8c can be observed in a wider range than the recess 8 of the first embodiment. The recess 8c can be easily visually recognized.

By the way, each of the recesses 8, 8a, 8b and 8c of the dressing board 4 in the above-described first to fourth embodiments is composed of one independent recess. However, each of the recesses 8, 8a, 8b and 8c of the dressing board 4 may be composed of two independent recesses.

FIG. 7A is a cross-sectional view of the dressing tool 2 according to the first modification of the first embodiment. The dressing board 4 according to the first modification of the first embodiment has a first recess 8-1 and a second recess 8-2 in the central portion on the back surface 4b side. Each of the first recess 8-1 and the second recess 8-2 is a generally cylindrical hole formed so as to be independent of each other.

The first recess 8-1 is formed from the back surface 4b to the position of the first depth d1, and the second recess 8-2 is deeper than the position of the back surface 4b to the first depth d1 ( That is, it is formed up to a position of a second depth d2 that does not reach the front surface 4a from the back surface 4b) (close to the front surface 4a).

Since the second depth d2 is deeper than the first depth d1, when the surface 4a side is worn, the second recess 8-2 appears on the surface 4a side before the first recess 8-1. Therefore, the second recess 8-2 appearing on the surface 4a side can be used as a warning display indicating that the thickness of the dressing board 4 is approaching the thickness of the use limit.

On the other hand, the depth of the first recess 8-1 is such that when the dressing board 4 is worn to the thickness limit of use, the first recess 8-1 is on the surface 4a side of the dressing board 4 that comes into contact with the grinding wheel 26. Is adjusted so that appears. That is, the first recess 8-1 appearing on the surface 4a side indicates that the dressing board 4 has been worn to the thickness of the use limit as in the first embodiment.

As described above, in the first modification of the first embodiment, the information regarding the usage limit can be displayed in two stages. When the second recess 8-2 appears on the surface 4a side, the operator or the like can recognize that the thickness of the dressing board 4 is approaching the thickness of the use limit, and the first recess 8-1 is formed. When it appears on the surface 4a side, it can be recognized that the dressing board 4 has been worn to the thickness of the use limit.

Therefore, the operator can take measures such as preparing a spare dressing tool 2 when the second recess 8-2 appears on the surface 4a side. Further, by replacing the dressing tool 2 with a new dressing tool 2 when the first recess 8-1 appears on the surface 4a side, damage to the grinding wheel 26 and the like can be prevented more reliably.

FIG. 7B is a sectional view taken along line BB of the dressing tool 2 according to the first modification of the second embodiment. The dressing board 4 according to the first modification of the second embodiment has a first recess 8a-1 and a second recess 8a-2.

The first recess 8a-1 and the second recess 8a-2 are recesses formed in a straight line parallel to each other when the dressing board 4 is viewed from the back surface 4b side, and are separated from each other so as to be independent of each other. Is formed.

More specifically, each of the first recess 8a-1 and the second recess 8a-2 is a linear groove having a longitudinal portion in a direction parallel to the radial direction of the dressing board 4. The first recess 8a-1 is a linear groove passing through the center O on the back surface 4b side of the dressing board 4, and the second recess 8a-2 (shown by a broken line in FIG. 7B) is the first. It is a linear groove that is arranged parallel to the recess 8a-1 of 1 and does not pass through the center O.

The first recess 8a-1 is formed from the back surface 4b to the position of the first depth d1, and the second recess 8a-2 is deeper than the position of the back surface 4b to the first depth d1 ( That is, it is formed up to a position of a second depth d2 that does not reach the front surface 4a from the back surface 4b) (close to the front surface 4a).

Even in the first modification of the second embodiment, the operator or the like states that the thickness of the dressing board 4 is approaching the thickness of the usage limit when the second recess 8a-2 appears on the surface 4a side. It can be recognized, and when the first recess 8a-1 appears on the surface 4a side, it can be recognized that the dressing board 4 has been worn to the thickness of the use limit.

FIG. 7C is a cross-sectional view of the dressing tool 2 according to the first modification of the third embodiment. The dressing board 4 according to the first modification of the third embodiment has a first recess 8b-1 and a second recess 8b-2. Each of the first recess 8b-1 and the second recess 8b-2 is a substantially columnar hole provided on the outer peripheral side of the center O of the back surface 4b of the dressing board 4.

Each of the first recess 8b-1 and the second recess 8b-2 is provided at different positions in the radial direction of the circular back surface 4b when the dressing board 4 is viewed from the back surface 4b side. Specifically, the center of the first recess 8b-1 on the back surface 4b is located at a distance of r / 2 from the center O.

On the other hand, the center of the second recess 8b-2 on the back surface 4b is located at a distance of 7r / 8 from the center O. The second recess 8b-2 is arranged on the side opposite to the first recess 8-1 with respect to the center O, but the arrangement of the second recess 8b-2 is not limited to this example. .. The first recess 8b-1 and the second recess 8b-2 may be arranged at arbitrary two positions from the center O as long as the distances from the center O are not the same.

The first recess 8b-1 is formed from the back surface 4b to the position of the first depth d1. On the other hand, the second recess 8b-2 has a second depth that is deeper than the position of the first depth d1 from the back surface 4b (that is, close to the front surface 4a) and does not reach the front surface 4b to the front surface 4a. It is formed up to the position of d2.

Also in the first modification of the third embodiment, when the second recess 8b-2 appears on the surface 4a side, it can be recognized that the thickness of the dressing board 4 is approaching the thickness of the use limit, and the first When the recess 8b-1 of the above appears on the surface 4a side, it can be recognized that the dressing board 4 has been worn to the thickness of the use limit.

FIG. 7D is a cross-sectional view of the dressing tool 2 according to the first modification of the fourth embodiment. The dressing board 4 according to the first modification of the fourth embodiment has an annular first recess 8c-1 and a second recess 8c-2, respectively, when viewed from the back surface 4b side.

Each of the first recess 8c-1 and the second recess 8c-2 is an annular groove provided on the outer peripheral side of the center О of the circular back surface 4b when the dressing board 4 is viewed from the back surface 4b side. Is. The first recess 8c-1 has a first diameter smaller than the diameter of the dressing board 4. On the other hand, the second recess 8c-2 has a second diameter larger than the diameter of the first recess 8c-1 and smaller than the diameter of the dressing board 4.

The first recess 8c-1 is provided inside the second recess 8c-2, but the first recess 8c-1 is provided outside the second recess 8c-2. You may be. Further, each of the first recess 8c-1 and the second recess 8c-2 does not necessarily have to be a perfect circle when viewed from the back surface 4b side.

The first recess 8c-1 is formed from the back surface 4b to the position of the first depth d1, and the second recess 8c-2 is deeper than the position of the back surface 4b to the first depth d1 ( That is, it is formed up to a position of a second depth d2 that does not reach the front surface 4a from the back surface 4b) (close to the front surface 4a).

Also in the first modification of the fourth embodiment, when the second recess 8c-2 appears on the surface 4a side, it can be recognized that the thickness of the dressing board 4 is approaching the thickness of the use limit, and the first When the recess 8c-1 of the above appears on the surface 4a side, it can be recognized that the dressing board 4 has been worn to the thickness of the use limit.

The dressing board 4 of the first modification of the first embodiment described above is provided with the first recess 8-1 and the second recess 8-2 that are independent of each other, but the first recess 8- A third recess 8-3 may be provided in a state in which the above-mentioned first recess 8-1 and the second recess 8-2 are connected in the depth direction of 1. That is, the first recess 8-1 and the second recess 8-2 may completely or partially overlap in the depth direction of the first recess 8-1.

FIG. 8A is a sectional view taken along the line AA of the dressing tool 2 according to the second modification of the first embodiment. The dressing board 4 according to the second modification of the first embodiment has a third recess 8-3 in the central portion on the back surface 4b side.

The third recess 8-3 is composed of the first recess 8-1 and the second recess 8-2 described above. The first recess 8-1 is a substantially columnar hole having a first depth d1. On the other hand, the second recess 8-2 is arranged substantially in the center of the first recess 8-1 when viewed from the back surface 4b side, and the second recess 8-2 is the first depth from the back surface 4b. It is a substantially columnar hole having a second depth d2 deeper than the position of the d1 and having a diameter smaller than that of the first recess 8-1.

The second recess 8-2 does not necessarily have to be arranged substantially in the center of the first recess 8-1 when viewed from the back surface 4b side. The second recess 8-2 may be arranged at an arbitrary position as long as it is inside the first recess 8-1 when viewed from the back surface 4b side.

Also in the second modification of the first embodiment, when the second recess 8-2 appears on the surface 4a side, it can be recognized that the thickness of the dressing board 4 is approaching the thickness of the use limit, and the first When the recess 8-1 of the above appears on the surface 4a side, it can be recognized that the dressing board 4 has been worn to the thickness of the use limit.

FIG. 8B is a sectional view taken along line BB of the dressing tool 2 according to the second modification of the second embodiment. The dressing board 4 according to the second modification of the second embodiment has a linear third recess 8a-3 having a longitudinal portion in the radial direction of the dressing board 4. The third recess 8a-3 passes through the center O on the back surface 4b side and is formed in a straight line having a longitudinal portion in the radial direction of the dressing board 4.

The third recess 8a-3 is also composed of the first recess 8a-1 and the second recess 8a-2 described above. The first recess 8a-1 is a linear groove having a first depth d1. On the other hand, the second recess 8a-2 is arranged substantially in the center of the first recess 8a-1 when viewed from the back surface 4b side, and has a second depth d2 deeper than the first depth d1. It is a linear groove having a width smaller than that of the first recess 8a-1 (that is, a length in a direction orthogonal to the longitudinal direction of the first recess 8a-1).

Also in the second modification of the second embodiment, when the second recess 8a-2 appears on the surface 4a side, it can be recognized that the thickness of the dressing board 4 is approaching the thickness of the use limit, and the first When the recess 8a-1 of the above appears on the surface 4a side, it can be recognized that the dressing board 4 has been worn to the thickness of the use limit.

The second recess 8a-2 does not necessarily have to be arranged substantially in the center of the first recess 8a-1 when viewed from the back surface 4b side. The second recess 8a-2 can be arranged at an arbitrary position as long as it is inside the first recess 8a-1 when viewed from the back surface 4b side.

FIG. 8C is a cross-sectional view taken along the line CC of the dressing tool 2 according to the second modification of the third embodiment. The dressing board 4 according to the second modification of the third embodiment has a third recess 8b-3 on the outer peripheral side of the center O on the back surface 4b side. The third recess 8b-3 is composed of the first recess 8b-1 and the second recess 8b-2 described above.

The first recess 8b-1 is a substantially columnar hole having a first depth d1. On the other hand, the second recess 8b-2 is arranged substantially in the center of the first recess 8b-1 when viewed from the back surface 4b side, and has a second depth d2 deeper than the first depth d1. , A generally columnar hole having a diameter smaller than that of the first recess 8b-1.

The center positions of the first recess 8b-1 and the second recess 8b-2 on the back surface 4b are arranged at the same positions outside the center O. The centers of the first recesses 8b-1 and the second recesses 8b-2 of this example are located at a distance of 7r / 8 from the center O.

However, the center positions of the first recess 8b-1 and the second recess 8b-2 are not limited to the positions 7r / 8 from the center O, and the positions from the center O to r / 2 and from the center O. It may be arranged at the position of 3r / 4.

Also in the second modification of the third embodiment, when the second recess 8b-2 appears on the surface 4a side, it can be recognized that the thickness of the dressing board 4 is approaching the thickness of the use limit, and the first When the recess 8b-1 of the above appears on the surface 4a side, it can be recognized that the dressing board 4 has been worn to the thickness of the use limit.

The second recess 8b-2 does not necessarily have to be arranged substantially in the center of the first recess 8b-1 when viewed from the back surface 4b side. The second recess 8b-2 can be arranged at any position as long as it is inside the first recess 8b-1 when viewed from the back surface 4b side.

FIG. 8D is a cross-sectional view taken along the line DD of the dressing tool 2 according to the second modification of the fourth embodiment. The dressing board 4 according to the second modification of the fourth embodiment has a third recess 8c-3 formed in an annular shape on the back surface 4b side. The third recess 8c-3 is composed of the above-mentioned first recess 8c-1 and the second recess 8c-2, which are annular, respectively.

The first recess 8c-1 is an annular groove having a first depth d1. On the other hand, the second recess 8c-2 is arranged at a position overlapping the first recess 8c-1 when viewed from the back surface 4b side, and has a second depth d2 deeper than the first depth d1. , An annular groove having a width smaller than the radial width of the first recess 8c-1.

The intermediate position between the inner diameter and the outer diameter of the second recess 8c-2 is arranged at the intermediate position between the inner diameter and the outer diameter of the first recess 8c-1 when viewed from the back surface 4b side. The arrangement of the recess 8c-2 of 2 is not limited to this example. The second recess 8c-2 can be arranged at any position as long as it is inside the first recess 8c-1 when viewed from the back surface 4b side.

Also in the second modification of the fourth embodiment, when the second recess 8c-2 appears on the surface 4a side, it can be recognized that the thickness of the dressing board 4 is approaching the thickness of the use limit, and the first When the recess 8c-1 of the above appears on the surface 4a side, it can be recognized that the dressing board 4 has been worn to the thickness of the use limit.

In addition, the configuration, method, and the like according to the above-described embodiment can be appropriately modified and implemented as long as they do not deviate from the scope of the object of the present invention. For example, the shape of the recess 8 or the like is not limited to a columnar shape, a linear shape, an annular shape, or the like, and may be a grid shape or a polygonal shape.

Further, characters, symbols, etc. for drawing the attention of the operator or the like may be written or attached to the position of the region corresponding to the recess 8 or the like on the surface 6a of the support plate 6. For example, by writing characters such as "danger", "stop", "end", and "Life End" in the area of the surface 6a of the support plate 6 corresponding to the recess 8 and the like, the recess 8 and the like are surfaced 4a. When appearing on the side, the operator can visually recognize characters such as "danger".

Further, the dressing tool 2 may be used for the purpose of shaping the grinding wheel 26, or may be used for the purpose of sharpening the grinding wheel 26. A dressing board 4 containing relatively large size abrasive grains is used for shaping the grinding wheel 26, and a dressing board 4 containing relatively small size abrasive grains is used for sharpening the grinding wheel 26. Can be done.

2 Dressing tool 4 Dressing board 4a Front surface 4b Back surface 6 Support plate 6a Surface surface 6b Back surface 8, 8a, 8b, 8c Recesses 8-1, 8a-1, 8b-1, 8c-1 First recesses 8-2, 8a- 2,8b-2,8c-2 Second recess 8-3,8a-3,8b-3,8c-3 Third recess 12 Grinding device 14 Spindle 16 Spindle housing 18 Grinding wheel 20 Wheel mount 22 Rotating mechanism 24 Wheel base 26 Grinding wheel 28 Holding table 28a Surface d1 First depth d2 Second depth r Radius О Center

Claims (6)

A dressing tool that dresses multiple grinding wheels arranged in a ring shape on one side of the grinding wheel.
A dressing section for dressing the grinding wheel and
A support portion that supports the back surface side of the dressing portion and
With
The back surface side of the dressing portion is provided with a recess having a depth corresponding to the thickness of the use limit of the dressing portion, which does not reach the surface surface of the dressing portion opposite to the back surface. A dressing tool characterized by being. The dressing tool according to claim 1, wherein the recess of the dressing portion is provided in a straight line when the dressing portion is viewed from the back surface side. The dressing tool according to claim 1, wherein the recess of the dressing portion is provided on the outer peripheral side of the center of the dressing portion when the dressing portion is viewed from the back surface side. The dressing tool according to claim 1, wherein the recess of the dressing portion is provided in an annular shape when the dressing portion is viewed from the back surface side. The recess of the dressing portion is characterized by including a first recess having a first depth and a second recess having a second depth deeper than the first depth. The dressing tool according to any one of items 1 to 4. The dressing tool according to claim 5, wherein the first recess and the second recess overlap each other in the depth direction of the recess.