JP5815422B2 - Grinding equipment - Google Patents

Description

  The present invention relates to a grinding apparatus for grinding a workpiece such as a semiconductor wafer, and in particular, automatically determines an origin position where a holding surface of a holding table that holds a placed workpiece and a grinding surface of a grinding wheel contacts. The present invention relates to a grinding apparatus having a setup mechanism that can be detected automatically.

  In the manufacturing process of semiconductor devices, lattice-shaped division planned lines are set on the surface of a wafer made of a semiconductor material such as silicon or gallium arsenide, and ICs, LSIs, etc. are formed in a large number of rectangular regions surrounded by the planned division lines. A device having the electronic circuit is formed. This wafer is divided into a large number of chip-like devices by cutting along a predetermined division line after undergoing a predetermined process such as grinding the back surface and thinning it to a set thickness. The device thus obtained is packaged with resin or ceramic and mounted on various electronic devices.

  The back grinding of the wafer is performed for the purpose of reducing the size and weight of the device and improving the heat dissipation characteristics. A grinding apparatus for grinding a wafer has a holding surface on which the wafer is placed, a holding table for holding the wafer placed on the holding surface, and a plurality of grindings for grinding the wafer held on the holding table A general configuration includes a grinding means for rotatably supporting a grinding wheel in which a grindstone is annularly arranged, and a processing feed means for moving the grinding means in a direction approaching and separating from the holding table. It has become. In such a grinding apparatus, the position where the holding surface of the holding table and the grinding surface of the grinding wheel come into contact with each other in the machining feed direction, which is usually the vertical direction, is set as the origin position, and the grinding amount (finished thickness) of the workpiece is set as the origin position. I have control.

  In grinding, the grinding wheel wears as the work piece is ground, and the holding table is self-grinded (the holding surface of the holding table is ground by grinding the holding surface of the holding table with the grinding wheel). Therefore, the workpiece cannot be ground with high accuracy unless the origin positioning, referred to as a setup for detecting the origin position again, is performed.

  The setup is performed by manual setup in which the operator feeds the grinding wheel in the direction approaching the holding table, detects the position where the grinding wheel touches the holding surface of the holding table, and sets that position as the origin position. (See Patent Document 1 etc.). However, manual setup has the problem that it takes time. Therefore, the present applicant has proposed a method capable of performing automatic setup using a setup mechanism instead of manual setup (Patent Document 2).

JP 2001-001261 A JP 2008-087104 A

  In the above-mentioned patent document 2, the detection unit (setup sensor) of the setup mechanism is disposed between the grinding wheel and the holding table, and grinding is performed when the upper end of the detection unit contacts the grinding wheel and the lower end contacts the holding table. A method is disclosed in which the origin position is calculated and set up based on the height position of the wheel and the height of the detection means recognized in advance. In such a method, when the contact surface of the upper end of the detection unit that contacts the lower surface of the grinding wheel is parallel to the lower surface of the grinding wheel (for example, the grinding surface of the grinding wheel), the thickness of the detection unit is appropriately set. Reflected and accurate setup is performed. That is, when setting up, the parallelism between the lower surface of the grinding wheel and the contact surface of the upper end of the detection unit is important.

  However, there is a problem that it is very difficult to set the contact surface of the upper end portion of the detection unit disclosed in Patent Document 2 in a state of being highly parallel to the lower surface of the grinding wheel.

  Particularly in recent years, the form of the grinding wheel has been diversified to grind various types of workpieces. For example, some grinding wheels in which a plurality of grinding wheels are arranged in an annular shape have a large interval between the grinding wheels. When setting up such a grinding wheel, it is necessary to set the contact surface of the upper end part of the detection part larger than before. In that case, it is difficult to obtain the parallelism with high accuracy.

  The present invention has been made in view of the above circumstances, and the main technical problem thereof is a grinding apparatus that can easily set the contact surface of the detection portion of the setup mechanism to the grinding surface of the grinding wheel in a parallel state. It is to provide.

  The grinding apparatus of the present invention has a holding table having a holding surface for holding a workpiece, and a grinding surface for grinding the workpiece that is disposed facing the holding table and held by the holding table. Grinding means including a grinding wheel having a grinding wheel, a spindle on which the grinding wheel is mounted and rotating the grinding wheel, and a processing feed means for moving the grinding means close to and away from the holding table. A grinding device, inserted between the holding surface of the holding table and the grinding surface of the grinding wheel, and an upper end portion with which the grinding surface of the grinding wheel abuts, and the holding surface of the holding table A lower end portion that comes into contact with the lower end portion, and the grinding means presses the upper end portion as the grinding means moves closer to the holding table, and the lower end portion comes into contact with the holding surface. Detect A tactile sensor is provided, and the upper end of the grinding wheel abuts on the grinding surface of the grinding wheel, and the contact sensor abuts on the holding surface of the holding table to detect the height position of the grinding surface with respect to the holding surface. And a positioning means for positioning the detection unit at a detection position and a retraction position between the holding surface of the holding table and the grinding surface of the grinding wheel. The upper end of the detection unit has a contact surface with which the grinding surface of the grinding wheel contacts, and a contact plate housed in a housing so that the corresponding contact surface protrudes; A restricting portion that restricts the contact plate from protruding from the housing, and the contact plate supported in the housing so that the contact surface is inclined to follow the grinding surface under the contact plate. And at least a supporting ball That.

  In the present invention, in a state where the detection unit of the setup mechanism is positioned at the detection position by the positioning unit, the grinding unit is brought close to the holding table by the processing feeding unit, and the grinding surface of the grinding wheel is brought into contact with the upper end of the detection unit. When contacting and pressing the contact surface of the plate, the contact sensor is activated when the lower end of the detection unit contacts the holding surface of the holding table. At this time, the origin position can be calculated from the height position of the grinding means and the thickness of the detection unit recognized in advance, and the setup can be performed automatically.

  According to the present invention, when the grinding surface of the grinding wheel comes into contact with the contact surface of the contact plate at the upper end portion of the detection unit, the corresponding contact surface is inclined following the grinding surface, thereby forming the grinding surface of the grinding wheel. On the other hand, the contact surface of the detection unit is in a parallel state. That is, the contact surface of the detection unit can be set parallel to the grinding surface of the grinding wheel simply by bringing the grinding surface of the grinding wheel into contact with the contact surface of the contact plate of the detection unit. Therefore, the setup can be performed with high accuracy by maintaining the state and performing the setup.

  According to the present invention, it is possible to provide a grinding device that can easily set the contact surface of the detection portion of the setup mechanism to the grinding surface of the grinding wheel in a parallel state.

It is a perspective view of the grinding device concerning one embodiment of the present invention. It is the (a) perspective view and the (b) side view which show the state which is grinding the to-be-processed object with the grinding means which the grinding device comprises. It is a side view of the setup mechanism which the grinding device comprises. It is a partial cross section side view which shows the detection part of the setup mechanism. It is a disassembled perspective view of the upper end part of the same detection part. It is a side view which shows the setting method of the setup mechanism. It is a side view which shows the setup method by the setup mechanism.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[1] Basic Configuration and Operation of Grinding Apparatus FIG. 1 shows the entire grinding apparatus 10 according to an embodiment. The grinding apparatus 10 is a device that uses a disk-shaped semiconductor wafer such as a silicon wafer as a workpiece (indicated by W in FIG. 2), and grinds, for example, the back surface of the workpiece W.

  The grinding apparatus 10 includes a rectangular parallelepiped base 11 whose upper surface is horizontal. In FIG. 1, the longitudinal direction, the width direction, and the vertical direction of the base 11 are shown as a Y direction, an X direction, and a Z direction (vertical direction), respectively. At one end portion of the base 11 in the Y direction, a column 12 arranged in the X direction is erected in a pair. On the base 11, a processing area 11A for grinding the workpiece W is provided on the column 12 side in the Y direction, and the workpiece W before grinding is placed in the processing area 11A on the side opposite to the column 12. A carry-in / carry-out area 11B for carrying in and carrying out the workpiece W after grinding is provided.

  In the processing area 11A, a disk-shaped turntable 13 whose rotation axis is parallel to the Z direction and whose upper surface is horizontal is rotatably provided. The turntable 13 is rotated in the direction of arrow R by a rotation drive mechanism (not shown). A plurality of (in this case, three) disk-shaped holding tables 20 whose rotation axis is parallel to the Z direction and whose upper surface is horizontal are arranged at equal intervals in the circumferential direction on the outer periphery of the turntable 13. It is arranged so that it can rotate.

  These holding tables 20 are of a generally known vacuum chuck type, and suck and hold the workpiece W placed on the upper surface by a vacuum suction action. As shown in FIG. 2, the holding table 20 has a structure in which a porous member 22 such as ceramic is fitted on an upper surface of a frame body 21 made of a metal such as stainless steel, and the upper surface of the porous member 22 is a workpiece. A holding surface 22a for W is formed. The holding surface 22a and the annular upper surface 21a of the frame body 21 around the holding surface 22a are shaved to be horizontal and flush with the above-described self-grinding by the grinding means 30 described later. Each holding table 20 is independently rotated or rotated in one direction or both directions by a rotation driving mechanism (not shown) provided in the turntable 13, and revolves when the turntable 13 rotates. It becomes a state.

  As shown in FIG. 1, in the state where two holding tables 20 are arranged in the X direction on the column 12 side, grinding means 30 are respectively disposed immediately above the holding tables 20. Each holding table 20 is positioned at three positions, that is, a grinding position below each grinding means 30 and a carry-in / carry-out position closest to the carry-in / carry-out area 11B by the rotation of the turntable 13.

  There are two grinding positions, and a grinding means 30 is provided for each of these grinding positions. In this case, the grinding position on the upstream side (back side in FIG. 1) in the conveying direction indicated by the arrow R of the holding table 20 by the rotation of the turntable 13 is the primary grinding position, and the downstream grinding position is the secondary grinding position. ing. Then, rough grinding is performed at the primary grinding position, and finish grinding is performed at the secondary grinding position.

  Each grinding means 30 is fixed to a slider 40 attached to the column 12 so as to be movable up and down. The slider 40 is slidably mounted on a guide rail 41 extending in the Z direction, and can be moved in the Z direction by a ball screw type processing feed means 43 driven by a servo motor 42. Each grinding means 30 is ground in the Z direction by the work feed means 43 and grinds the exposed grinding surface of the work W held on the holding table 20 by a work feed operation that approaches the holding table 20 by lowering. .

  As shown in FIG. 2, the grinding means 30 has a cylindrical spindle 31 whose axial direction extends in the Z direction. The spindle 31 includes a motor 33 that rotatably supports the spindle shaft 32 and drives the spindle shaft 32 to rotate. A disc-shaped wheel mount 34 is fixed to the lower end of the spindle shaft 32, and a grinding wheel 35 is detachably fixed to the lower surface of the wheel mount 34 by fixing means such as screwing.

  The grinding wheel 35 has a plurality of grinding wheels 37 arranged at equal intervals and fixed to the lower surface of an annular wheel base 36. The grinding wheel 37 is selected according to the workpiece W. For example, a grinding wheel 37 formed by mixing diamond abrasive grains in a binder such as vitrified is used.

  A grinding wheel 35 having a grinding wheel for rough grinding (for example, a grindstone containing abrasive grains of # 320 to # 400) fixed to a wheel mount 34 of the grinding means 30 for primary grinding disposed above the primary grinding position. Is attached. Further, a grinding wheel for finishing grinding (for example, a grindstone containing abrasive grains of # 2000 or more) is fixed to the wheel mount 34 of the grinding means 30 for secondary grinding disposed above the secondary grinding position. A wheel 35 is attached. The wheel mount 34 and the grinding wheel 35 are provided with a grinding water supply mechanism (not shown) for supplying grinding water for cooling and lubrication of the grinding part or discharging grinding debris.

  As shown in FIG. 1, in the vicinity of the primary grinding position and the secondary grinding position around the turntable 13 on the base 11, a contact-type thickness measuring device 50 composed of a pair of swingable height gauges. Are arranged respectively.

  As shown in FIG. 2, the pair of height gauges are a reference-side height gauge 51 and a movable-side height gauge 52 provided with probes 51a and 52a that swing vertically. The reference-side height gauge 51 is set in a state where the tip of the probe 51a is in contact with the upper surface 21a of the frame 21 of the holding table 20 that is not covered with the workpiece W, and the movable-side height gauge 52 is the tip of the probe 52a. Set to be in contact with the surface to be ground. According to the thickness measuring instrument 50, the height position of the upper surface 21a of the frame 21 serving as a reference surface is detected by the reference side height gauge 51, and the workpiece W to be ground is ground by the movable side height gauge 52. By detecting the height position of the surface and comparing the detected values of both, the thickness of the workpiece W is measured at any time during grinding.

  The grinding means 30 is lowered and fed at a predetermined speed (for example, about 0.3 to 0.5 μm / second) while the grinding wheel 35 rotates, whereby the grinding wheel 37 of the grinding wheel 35 is processed. The surface to be ground of W is pressed, whereby the surface to be ground is ground. At the time of grinding, the holding table 20 rotates in the same direction as the grinding wheel 35, for example, and the workpiece W is rotated. The grinding outer diameter by the grinding wheel 35 is larger than the radius of the holding surface 22a, and the grinding outer peripheral edge by the grinding wheel 37 passes through the center of rotation of the holding table 20, that is, the center of the workpiece W. Is uniformly ground by the grinding wheel 37. The amount of grinding by the grinding means 30 is controlled by measuring the thickness of the workpiece W with the thickness measuring device 50.

  The workpiece W is first roughly ground by the grinding means 30 at the primary grinding position, and then conveyed to the secondary grinding position by the turntable 13 rotating in the R direction shown in FIG. It is finish ground by. In rough grinding, for example, grinding is performed up to about several tens of μm before the finish thickness, and the remaining grinding amount is ground by finish grinding.

  As shown in FIG. 1, a pickup robot 70 is installed in the center of the carry-in / out area 11B. Around the pickup robot 70, a supply cassette 71 and an alignment table 72 are counterclockwise as viewed from above. , A supply arm 73, a recovery arm 74, a spinner type cleaning device 75, and a recovery cassette 76 are arranged. A plurality of workpieces W are accommodated in the cassettes 71 and 76 in a stacked state with a space in the vertical direction. These cassettes 71 and 76 are detachably set at predetermined positions on the base 11.

  The workpiece W to be ground is first taken out from the supply cassette 71 by the pick-up robot 70, placed on the alignment table 72 with the surface to be ground facing upward, and positioned at a certain loading start position. . Next, the workpiece W is picked up from the alignment table 72 by the supply arm 73 and placed on the holding table 20 waiting at the loading / unloading position with the surface to be ground facing upward. The workpiece W is conveyed to the primary grinding position and the secondary grinding position in this order by the rotation of the turntable 13 in the R direction, and the grinding surface is ground by the grinding means 30 at these grinding positions as described above. The

  The workpiece W for which the secondary grinding has been completed is returned to the loading / unloading position when the turntable 13 further rotates in the R direction. The workpiece W returned to the loading / unloading position is picked up by the recovery arm 74, transferred to the cleaning device 75, washed with water and dried. The workpiece W cleaned by the cleaning device 75 is accommodated in the collection cassette 76 by the pickup robot 70.

  The above is the basic configuration and operation of the grinding apparatus 10 when actually grinding the workpiece W. Now, in the grinding apparatus 10 of this embodiment, a setup mechanism 100 for performing setup prior to actual grinding is provided for each grinding means 30 on the primary grinding side and the secondary grinding side. . As shown in FIG. 1, the setup mechanism 100 is disposed around the turntable 13 on the base 11 and on the column 12 side of each thickness measuring device 50. Hereinafter, the setup mechanism 100 will be described.

[2] Configuration of Setup Mechanism As shown in FIG. 3, the setup mechanism 100 horizontally rotates a pair of upper and lower leaf springs 101 extending horizontally, a detection unit 110 supported at the tip of the leaf spring 101, and the leaf spring 101. Thus, the detection unit 110 does not interfere with the detection position between the holding surface 22a of the holding table 20 and the grinding surface 37a of the grinding wheel 37 and the grinding means 30 that is detached from the holding table 20 and processed and fed. Positioning means 140 are provided for positioning at the retracted positions (indicated by broken lines in FIG. 1). The leaf spring 101 is bent in the vertical direction and can be elastically deformed, so that the detection unit 110 can move in the vertical direction. In addition, it is good also as a structure which replaces with the leaf | plate spring 101 and supports the detection part 110 so that a vertical motion is possible using a parallel link.

  The positioning means 140 includes a post 141 that is vertically and rotatably supported on the base 11, and a rotation drive mechanism 142 that rotates the post 141. The rotational drive mechanism 142 includes a shaft 143 that extends coaxially downward from the lower end surface of the post 141, and a gear 143a provided integrally therewith, and a motor 144 that is coupled to the gear 143a via a pinion gear 144a. The base end portion of the leaf spring 101 is fixed to the outer peripheral surface of the upper end portion of the post 141.

  According to the positioning means 140, the power of the motor 144 is transmitted to the post 141 via the pinion gear 144a, the gear 143a, and the shaft 143, and the post 141 rotates, whereby the leaf spring 101 reciprocates and the detection unit 110 moves to the detection position. Alternatively, it is positioned at the retracted position.

  The detection unit 110 is provided with an upper end 120 on which the grinding surface 37 a of the grinding wheel 37 can come into contact, and a lower end on the lower side of the upper end 120 that can be in contact with the holding surface 22 a of the holding table 20. 130. The upper end 120 and the lower end 130 are fixed to the tip of the leaf spring 101 via the bracket 111.

  As shown in FIG. 4, the lower end portion 130 of the detection unit 110 has a support 131 fixed to the bracket 111, and an object (in this case, the holding table 20) contacts the support 131 on the lower surface. A contact probe 132 that can be disposed and a contact sensor 133 that detects that the contact probe 132 has contacted an object below are supported.

  As shown in FIGS. 4 and 5, the upper end portion 120 of the detection unit 110 has a rectangular parallelepiped casing 121 fixed to the bracket 111. The casing 121 is configured by detachably attaching a bottom plate 125 that closes a lower opening to a lower surface of a casing main body 124 in which an upper plate portion 123 is formed on an upper surface of a side wall portion 122 that surrounds four sides. One surface of 122 is fixed to the bracket 111. A circular hole 123a is formed at the center of the upper plate portion 123 of the housing main body 124, and the upper plate portion 123 constitutes an edge portion surrounding the circular hole 123a.

  A contact plate 126, a support ball 127, and a washer 128 are accommodated in the housing main body 124 from the lower opening, and the upper end 120 is configured by attaching the bottom plate 125 to the lower surface of the housing main body 124. The bottom plate 125 is attached to the housing main body 124 by screwing screws 129 passed through insertion holes 125 a formed at two corners away from the bracket 111 into screw holes formed in the housing main body 124.

  The contact plate 126 has a shape obtained by cutting the apex side of the hemisphere parallel to the bottom surface, and has a circular bottom surface 126a on the bottom surface side, a flat surface that is smaller in diameter than the bottom surface 126a and concentric with the bottom surface. A contact surface 126b. A conical recess 126 c into which a part of the support ball 127 can enter is formed at the center of the lower surface 126 a of the contact plate 126, and a part of the support ball 127 is formed at the center of the bottom plate 125. A support hole 125c into which can enter is formed.

  In a state where the bottom plate 125 is attached to the housing main body 124 with the screws 129 passed through the two corners, the upper end portion 120 of the contact plate 126 protrudes from the circular hole 123a into the housing 121, and the support ball 127 is provided. The upper end portion 120 of the contact plate 126 enters the recess 126c of the lower surface 126a of the contact plate 126, and the lower end portion 130 of the support ball 127 enters the washer 128 and the support hole 125c of the bottom plate 125. The sphere 127 and the washer 128 are accommodated in a state sandwiched between the upper plate portion 123 and the bottom plate 125. The contact plate 126 is restricted from jumping out of the circular hole 123a by the lower part of the spherical surface (restricting portion) 126d extending from the contact surface 126b to the lower surface 126a contacting the edge of the upper plate portion 123.

  In such an upper end portion 120, when the tightening force of the screw 129 is loosened, the force with which the bottom plate 125 presses the contact plate 126 against the edge of the upper plate portion 123 via the support ball 127 is weakened. 126 can swing in all directions with the support ball 127 as a fulcrum. That is, the flat contact surface 126b protruding above the housing 121 can be inclined in all directions. The support ball 127 is maintained in an unrollable state by entering the recess 126 c of the contact plate 126 and the support hole 125 c of the bottom plate 125. The thickness of the detection unit 110, that is, the distance from the contact surface 126b of the contact plate 126 of the upper end 120 to the lower end of the contact probe 132 of the lower end 130 is set to a predetermined size, and the thickness is the thickness of the detection unit 110. As such, it is recognized in advance.

[3] Setting of Setup Mechanism The above is the configuration of the setup mechanism 100. Next, the setup of the setup mechanism 100 will be described. The setup mechanism 100 is provided for each grinding means 30 on the primary grinding side and the secondary grinding side, and the setup mechanism 100 is set, for example, when the apparatus 10 is assembled or before it is used for the first time. .

  A setting method of the setup mechanism 100 will be described with reference to FIG. 6. First, the screw 129 of the upper end 120 of the detection unit 110 is loosened so that the contact plate 126 can swing. Next, the leaf spring 101 is turned by the positioning means 140, and the detection unit 110 is positioned at a detection position between the holding surface 22 a of the holding table 20 and the grinding surface 37 a of the grinding wheel 37. The detection unit 110 is configured such that the contact probe 132 at the lower end portion 130 is separated from the holding surface 22a to some extent at the detection position. Next, the grinding means 30 is lowered by the processing feed means 43, and the grinding surface 37 a of the grinding wheel 37 is brought into contact with the contact surface 126 b of the contact plate 126. The grinding means 30 is further lowered slightly from this state, and the upper end 120 is pressed to such an extent that the leaf spring 101 is slightly bent.

  Then, the detection unit 110 is pressed toward the upper grinding wheel 37 by the elastic force of the leaf spring 101, and the pressing plate 126 swings the contact plate 126 that is in contact with the grinding surface 37a of the grinding wheel 37. The contact surface 126b is in close contact with the grinding surface 37a. That is, the contact surface 126b is inclined following the grinding surface 37a, and the contact surface 126b is parallel to the grinding surface 37a. Next, the screw 129 is screwed into the housing main body 124 to fasten the bottom plate 125 to the housing main body 124. As a result, the contact plate 126 is fixed in the housing 121, and the state in which the contact surface 126b is parallel to the grinding surface 37a is maintained. This completes the setting operation of the setup mechanism 100 that adjusts the contact surface 126b of the detection unit 110 with which the grinding surface 37a of the grinding wheel 37 contacts to be parallel to the grinding surface 37a. After the setup mechanism 100 is set, the positioning unit 140 retracts the detection unit 110 to the retracted position. The radius of curvature of the spherical surface 126d of the contact plate 126 is the distance from the center of the support sphere 127 to the spherical surface 126d when the contact surface 126b is parallel to the grinding surface 37a of the grinding wheel 37 as described above. Is set.

[4] Setup by Setup Mechanism Next, a method for performing setup by the setup mechanism 100 in which the parallelism of the contact surface 126b with respect to the grinding surface 37a is set as described above will be described. The setup is performed as needed, such as when the apparatus is started up, after the above-described self-grinding, or when the grinding wheel 37 is worn or the holding table 20 is replaced.

  A setup method will be described with reference to FIG. 7. The positioning unit 140 moves the detection unit 110 from the retracted position to the detection position. Then, the grinding means 30 is lowered by the processing feed means 43, the grinding surface 37a of the grinding wheel 37 is brought into contact with the contact surface 126b of the contact plate 126, and the upper end 120 is pushed down. Then, the lower end of the contact probe 132 contacts the holding surface 22a, and the contact sensor 133 is turned on. At this time, the origin position is calculated from the height position of the grinding means 30 and the thickness of the detection unit 110 recognized in advance, and the setup is automatically performed.

[5] Effect of Setup Mechanism According to the setup mechanism 100 of the above embodiment, when the setup mechanism 100 is set, the grinding means 30 is lowered and the grinding surface 37a of the grinding wheel 37 is moved to the upper end 120 of the detection unit 110. By abutting against and abutting against the abutting surface 126b of the abutting plate 126, the abutting surface 126b comes into close contact with the grinding surface 37a in an inclined manner following the grinding surface 37a. The contact surface 126b of the detection unit 110 can be set in parallel.

  The parallelism setting of the contact surface 126b can be achieved simply by bringing the grinding surface 37a of the grinding wheel 37 into contact with the contact surface 126b of the contact plate 126 of the detection unit 110, and then the screw 129 is moved. The parallelism can be maintained by fastening and holding the contact plate 126 in the housing 121. Therefore, the contact surface 126b of the detection unit 110 can be easily set to be parallel to the grinding surface 37a of the grinding wheel 37. As a result, setup can be performed with high accuracy.

  In the present embodiment, the screw 129 for fixing the bottom plate 125 to the casing main body 124 and holding the contact plate 126 in the casing 121 in the fixed state at the upper end 120 of the detection unit 110 is provided in the bottom plate 125. It is arranged at two corners away from the bracket 111 in this embodiment and is configured to screw this portion, and the two corners on the bracket 111 side are not screwed. This is because it is sufficient to fix the contact plate 126 with an appropriate force that does not move. In addition, there is an advantage that the support ball 127 and the contact plate 126 are not excessively pressurized and are not easily damaged. Furthermore, although it is difficult to make a space for screw tightening on the bracket 111 side, such a space can be secured on the side away from the bracket 111, and the setting work of the setup mechanism 100 is easy. . In addition, if the bottom plate 125 is made of a material that is appropriately bent and has rigidity, even if the screw 129 is strongly tightened, the bottom plate 125 bends, so that the support ball 127 and the contact plate 126 are hardly damaged. This is preferable.

  DESCRIPTION OF SYMBOLS 20 ... Holding table, 22a ... Holding surface, 30 ... Grinding means, 31 ... Spindle, 35 ... Grinding wheel, 37 ... Grinding wheel, 37a ... Grinding surface, 43 ... Work feed means, 100 ... Setup mechanism, 110 ... Detection part, DESCRIPTION OF SYMBOLS 120 ... Upper end part, 121 ... Housing | casing, 126 ... Contact plate, 126b ... Contact surface, 126d ... Spherical surface (regulation part), 127 ... Support ball | bowl, 130 ... Lower end part, 133 ... Contact sensor, 140 ... Positioning means, W: Work piece.

Claims (1)

A holding table having a holding surface for holding a workpiece; and a grinding wheel having a grinding wheel having a grinding surface arranged to face the holding table and grinding the workpiece held by the holding table; A grinding apparatus comprising: grinding means including a spindle on which the grinding wheel is mounted and rotating the grinding wheel; and processing feed means for moving the grinding means close to and away from the holding table,
An upper end portion that is inserted between the holding surface of the holding table and the grinding surface of the grinding wheel and is in contact with the grinding surface of the grinding wheel; and a lower end portion that is in contact with the holding surface of the holding table; The lower end portion is a contact sensor that detects that the grinding wheel presses the upper end portion and the lower end portion contacts the holding surface as the grinding means moves closer to the holding table. The upper end of the grinding wheel is in contact with the grinding surface of the grinding wheel and the contact sensor is in contact with the holding surface of the holding table to detect the height position of the grinding surface with respect to the holding surface. A detector having a predetermined thickness; and positioning means for positioning the detector at a detection position and a retraction position between the holding surface of the holding table and the grinding surface of the grinding wheel. It has a setup mechanism,
The upper end portion of the detection unit has a contact surface with which the grinding surface of the grinding wheel contacts, and a contact plate housed in the housing so that the corresponding contact surface protrudes;
A restricting portion for restricting the contact plate from popping out of the housing;
A support ball that is accommodated in the housing and supports the contact plate so that the contact surface is inclined to follow the grinding surface under the contact plate;
A grinding apparatus comprising at least

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