JP2019123046A - Dressing method - Google Patents

Abstract

To enable continuous grinding processing by completing dressing and setup without the help of an operator when dressing a grindstone.SOLUTION: A dressing method comprises a process of holding a dressing board B by a table 30, a dressing process of grinding the board B by descending grinding means 6 by a specified quantity from a slightly upper position than the board B held by a holding surface 300a of the table 30, a post-dressing thickness calculation process of calculating a difference between a height position of the holding surface of the table 30 measured by height measurement means 381 and 382 and a height position of an upper surface B1a of the board B held by the holding surface as a thickness value of the board B by stopping rotation of the table 30 after the dressing process and a setup process of storing a height position of subtracting the thickness value of the board B after dressing from a height position of the grinding means 6 when finishing the dressing process, as a height position where a grinding surface of a grindstone 641 contacts with the holding surface 300a when descending the grinding means 6.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a dressing method for dressing the grinding surface of a grinding wheel.

  In a grinding device for grinding a plate-like workpiece by rotating a grinding wheel in which a grinding wheel is annularly arranged, when the workpiece is hard, the grinding surface of the grinding wheel is crushed and the workpiece is soft and grinding debris Adheres to the grinding surface and clogs. Thus, the grinding ability of the grinding wheel is reduced due to clogging or clogging. As a countermeasure for this, a dressing board is used to periodically dress the grinding surface of the grinding wheel, and abrasive grains are newly exposed on the grinding surface to adjust the condition of the grinding surface (for example, see Patent Document 1).

JP, 2008-207302, A

  In the conventional dressing method, before dressing, a dressing board having a known thickness is held on a holding table, the thickness of the dressing board is input and set in the grinding apparatus, and the grinding surface of the grinding stone is dressed by a predetermined amount. Thereafter, the grinding wheel is lowered to bring the grinding surface into contact with the holding surface of the holding table, and the grinding feed position at the time of the contact is stored in the grinding device. And the above-mentioned series of processes are performed while the operator's apparatus operation intervenes.

However, when the dressing of the grinding wheel and the setup of the grinding feed position are performed while the operator's operation of the apparatus is involved as described above, it takes time and effort to perform dressing, and the continuity of the workpiece There is a problem that it is impossible to carry out a typical grinding process.
Therefore, when dressing the grinding stone, there is a problem that the dressing and the setup are completed without the intervention of the operator, and the continuous grinding of the workpiece is possible.

  In the present invention for solving the above problems, a holding table holding a dressing board made of a plate-like grinding wheel is rotated about the center of the holding surface as an axis, and a grinding wheel in which a grinding wheel is annularly disposed is used as a grinding wheel center A dressing method of rotating a shaft and contacting a grinding surface of a grinding wheel with a dressing board held by the holding table and dressing the grinding surface, the holding step of holding the dressing board on the holding table, the holding surface And lowering the grinding means on the ground surface by lowering the grinding means by a predetermined amount from a position slightly above the upper surface of the dressing board held by the holding unit, and stopping the rotation of the holding table after the dressing step. Height position of the holding surface of the holding table measured by the length measuring means and the dressing held by the holding surface Calculating the difference between the height of the upper surface of the dressing and the height value of the dressing board as a thickness value of the dressing board, and calculating the dressing board after dressing from the height position of the grinding means at the end of the dressing process. And d) storing the height position obtained by subtracting the thickness value as the height position at which the grinding surface contacts the holding surface when the grinding means is lowered.

  In the dressing method according to the present invention, the holding surface of the holding table measured by the height measuring unit when the holding table is rotated and the workpiece held by the holding table is ground by the grinding stone A grinding process for calculating the difference between the height position and the height position of the upper surface of the workpiece as the thickness value of the workpiece and recognizing the height position of the grinding means, and at the end of the grinding process By subtracting the thickness value of the workpiece at the end of the grinding process from the height position of the grinding means, the height position of the grinding means at which the grinding surface contacts the holding surface at the end of the grinding process After the storage step of calculating and storing, and after the holding step and before the dressing step, the rotation of the holding table is stopped, and the height position of the holding surface measured by the height measuring means and the holding surface are held. Said dressing board Pre-dressing thickness calculation step of calculating the difference between the upper surface and the height position as the thickness value of the dressing board, and the height position of the grinding means stored in the storage step It is preferable to include a start position calculating step of setting the height position obtained by adding the thickness value of the dressing board to the height position at which the dressing of the grinding wheel is started.

  The dressing method according to the present invention includes a holding step of holding the dressing board on the holding table, and grinding the dressing board on the grinding surface by lowering the grinding means from the position slightly above the upper surface of the dressing board held by the holding surface. Between the dressing process and the height position of the holding surface of the holding table measured by the height measuring means by stopping the rotation of the holding table after the dressing process and the height position of the upper surface of the dressing board held by the holding surface The grinding position is calculated by subtracting the thickness value of the dressing board after dressing from the height position of the grinding means at the end of the dressing process. The setup process which memorizes as the height position where the grinding surface contacts the holding surface when it is lowered To prepare the later dressing grinding apparatus irrespective of setup operation the grinding surface to store the height position of the grinding means in contact with the worker becomes possible to perform automatically on the holding surface. Since the setup is automatically completed after dressing, it is possible to smoothly and continuously carry out the subsequent grinding of the workpiece.

  In the dressing method according to the present invention, the height position of the holding surface and the workpiece measured by the height measuring unit when the workpiece held by the holding table is rotated by the holding table while rotating the holding table. Grinding process from the height position of the grinding means at the end of the grinding process, calculating the difference between the height position of the upper surface of the workpiece as the thickness value of the workpiece and recognizing the height position of the grinding means A storage step of calculating and storing the height position of the grinding means whose grinding surface contacts the holding surface at the end of the grinding process by subtracting the thickness value of the workpiece at the end of the process; and the dressing after the holding step The difference between the height position of the holding surface measured by the height measurement means and the height position of the upper surface of the dressing board held by the holding surface by stopping the rotation of the holding table before the process is taken as the thickness value of the dressing board Calculation Starts dressing the grinding stone at the height position where the thickness value of the dressing board calculated in the pre-dressing thickness calculation step is added to the height position of the grinding means stored in the pre-dressing thickness calculation step and the storage step By providing the start position calculation step of setting the height position, the grinding apparatus can automatically perform dressing of the grinding wheel while grinding is continuously performed. Therefore, continuous grinding of the workpiece is possible.

It is a perspective view showing an example of a grinding device. It is a sectional view showing an example of the structure of a grinding device. It is a flowchart explaining an example of a flow of each process of a dressing method of Embodiment 1. It is sectional drawing which shows the state which hold | maintained the dressing board on the holding table. It is sectional drawing explaining the state which is calculating the thickness value of the dressing board before dressing. It is sectional drawing explaining the state which is grinding the dressing board in the grinding surface of a grinding stone. It is sectional drawing explaining the state which is calculating the thickness value of the dressing board after dressing. The height position obtained by subtracting the thickness value of the dressing board after dressing from the height position of the grinding means at the end of the dressing process is stored as the height position at which the grinding surface contacts the holding surface when the grinding means is lowered. It is sectional drawing explaining the state which is. It is a flowchart explaining an example of the flow of each process of the dressing method of Embodiment 2. It is sectional drawing explaining a grinding process and a memory | storage process. It is sectional drawing explaining the state which is calculating the thickness value of the dressing board before dressing. The grinding means is lowered from the height position slightly above the height position obtained by adding the thickness value of the dressing board calculated in the pre-dressing thickness calculation step to the height position of the grinding means stored in the storage step It is sectional drawing explaining the state which is grinding the dressing board by the grinding surface of a grinding stone. It is sectional drawing explaining the state which is calculating the thickness value of the dressing board after dressing. The height position obtained by subtracting the thickness value of the dressing board after dressing from the height position of the grinding means at the end of the dressing process is stored as the height position at which the grinding surface contacts the holding surface when the grinding means is lowered. It is sectional drawing explaining the state which is.

The grinding apparatus 1 shown in FIG. 1 is an apparatus for grinding the workpiece W held on the holding table 30 by the grinding means 6. The front (−X direction side) on the base 10 of the grinding apparatus 1 is an area where the workpiece W or the dressing board B is attached to and removed from the holding table 30, and the rear (+ X direction) on the base 10 The side) is an area where grinding of the workpiece W held on the holding table 30 by the grinding means 6 or grinding of the dressing board B (dressing of the grinding wheel 641 of the grinding means 6) is performed.
In the grinding apparatus 1, the workpiece W or the dressing board B is housed, for example, in a shelf shape in a wafer cassette, carried out of the wafer cassette by a carrying in / out means not shown, and carried in on the holding table 30.

  A column 17 is erected on the rear side (+ X direction side) on the base 10 of the grinding apparatus 1, and a grinding feed for grinding-feeding the grinding means 6 in the Z-axis direction (vertical direction) on the front surface of the column 17 Means 7 are provided. The grinding feed means 7 includes a ball screw 70 having an axial center in the Z-axis direction, a pair of guide rails 71 disposed parallel to the ball screw 70, a motor 72 coupled to the ball screw 70 and rotating the ball screw 70, and The motor 72 rotates the ball screw 70. The motor 72 rotates the ball screw 70. The motor 72 rotates the ball screw 70. Then, the lift plate 73 is guided by the guide rail 71 to reciprocate in the Z-axis direction, and the grinding means 6 supported by the holder 74 also reciprocates in the Z-axis direction.

  The grinding means 6 is attached to the lower end of the rotary shaft 60, a rotary shaft 60 whose axial direction is the Z-axis direction, a housing 61 rotatably supporting the rotary shaft 60, a motor 62 rotating the rotary shaft 60, and And a grinding wheel 64 removably connected to the mount 63. The grinding wheel 64 includes a wheel base 640, and a grinding stone 641 having a substantially rectangular parallelepiped outer shape and disposed in a plurality of rings on the lower surface of the wheel base 640. The grinding wheel 641 is formed by adhering diamond abrasive grains or the like with an appropriate bonding agent.

  The holding table 30 having a circular outer shape is provided with an adsorbing portion 300 which is made of a porous member or the like and adsorbs the workpiece W, and a frame body 301 which supports the adsorbing portion 300. The suction unit 300 of the holding table 30 communicates with a suction source (not shown) including a vacuum generator such as a vacuum pump or an ejector, and the suction force generated by the suction source suctions the holding surface 300 a of the holding table 30. The holding table 30 can suction and hold the workpiece W on the holding surface 300a. The holding surface 300 a is formed in a conical surface having a very gentle inclination whose apex is the rotation center of the holding table 30. Further, the holding table 30 is surrounded by the cover 39 from the periphery, and the X-axis on the base 10 by the X-axis direction feeding means (not shown) disposed below the cover 39 and the bellows cover 39a connected to the cover 39. It can move back and forth in the direction.

  As shown in FIG. 2, below the holding table 30, a rotating means 32 including a motor and a rotating shaft is disposed, and the holding table 30 can be rotated about an axis in the Z-axis direction by the rotating means 32. It has become.

  As shown in FIG. 2, for example, the holding table 30 is supported by a tilt adjusting unit 35 that adjusts the tilt of the holding table 30 on the base 10. A plurality of (for example, three) inclination adjusters 35 are disposed on the bottom side of the holding table 30 at regular intervals in the circumferential direction. The tilt adjustment unit 35 includes a support post 35a rotatably supporting the holding table 30 via a bearing or the like, a screw portion 35b having an axial center in the Z-axis direction and screwed with the support post 35a, a screw portion 35b and a bearing And the motor 35d is coupled to the motor 35d via the coupling 35c, and when the motor 35d rotates the screw portion 35b, the support post 35a reciprocates in the Z-axis direction, and the holding surface of the holding table 30 is held. The inclination of the surface 300a with respect to the horizontal plane is adjusted.

  As shown in FIG. 1, for example, at the side of the movement path of the holding table 30, a pair of contact-type height measuring means (height gauges), ie, a first for measuring the height of the holding surface 300a of the holding table 30. A height measuring means 381 and a second height measuring means 382 for measuring the height of the upper surface Wb of the workpiece W held by the holding table 30 are provided.

The first height measuring means 381 and the second height measuring means 382 are provided with contacts which are vertically moved up and down at their respective tips to make contact with the respective measurement surfaces, and the respective contacts are arranged on the respective measurement surfaces. Measure the height while pressing with an appropriate force. Note that the first height measuring means 381 and the second height measuring means 382 are not limited to contact height gauges, and for example, they have a light emitting part and a light receiving part and are noncontacting on the measurement surface. It may be a reflection type optical sensor capable of measuring the height.
A thickness calculating unit 37 for measuring the thickness of the workpiece W is electrically connected to the first height measuring unit 381 and the second height measuring unit 382. The thickness calculating means 37 calculates the height of the upper surface Wb of the workpiece W measured by the second height measuring means 382 and the height of the holding surface 300 a of the holding table 30 measured by the first height measuring means 381. The difference is calculated as the thickness of the workpiece W.

  As shown in FIG. 2, the grinding apparatus 1 is provided with position recognition means 18 for recognizing the height position of the grinding means 6. The position recognition means 18 is, for example, a scale 180 fixed to the column 17 and extending in the moving direction (Z-axis direction) of the grinding means 6, and fixed to the lift plate 73 and moved together with the lift plate 73 along the scale 180 And a reading unit 181 that reads the 180 scale. The reading unit 181 is, for example, an optical type that reads the reflected light of the scale formed on the scale 180, and detects the scale of the scale 180 to detect the height position of the grinding means 6 in the Z-axis direction.

  As shown in FIG. 1, the grinding apparatus 1 includes, for example, a control unit 9 configured of a CPU or the like that performs arithmetic processing in accordance with a control program and that controls the entire apparatus. The control means 9 is connected to the grinding feed means 7 and the grinding means 6 by wiring not shown, and under the control of the control means 9, the grinding feed operation in the Z axis direction of the grinding means 6 by the grinding feed means 7 , And the rotation operation of the grinding means 6 are controlled. Further, the control means 9 includes a storage unit 90 formed of a storage element such as a memory.

(Embodiment 1)
Below, each step in the case of enforcing the dressing method which concerns on this invention using the grinding apparatus 1 is demonstrated. The steps of the dressing method in the present embodiment are performed in the order shown in the flowchart shown in FIG.

(1) Holding Step Dressing board B shown in FIG. 1 includes, for example, a plate-like grindstone B1 and a circular plate-like holding plate B2 holding the plate-like grindstone B1. The plate-like grindstone B1 is formed in, for example, a circular plate shape by adhering diamond abrasive grains or CBN abrasive grains with an appropriate bonding agent. The plate-like grindstone B1 is adhered to the upper surface of the holding plate B2 with an adhesive.

  First, in the attachment / removal region of the grinding apparatus 1 shown in FIG. 1, the dressing board B is placed on the holding surface 300a of the holding table 30 so that the upper surface B1a (upper surface of the plate-like grindstone B1) is on the upper side Placed on Then, the suction force generated by a suction source (not shown) is transmitted to the holding surface 300a, whereby the holding table 30 sucks and holds the dressing board B on the holding surface 300a, as shown in FIG.

  The inclination of the holding table 30 is adjusted by the inclination adjusting unit 35 shown in FIG. 4 so that the holding surface 300a, which is a very gentle conical surface, is parallel to the grinding surface (lower surface) of the grinding wheel 641 (see FIG. 2). By adjusting, the upper surface B1a of the dressing board B suctioned and held along the holding surface 300a which is a conical surface becomes parallel to the grinding surface of the grinding wheel 641. In addition, in FIG. 4, the inclination adjustment part 35 is simplified and shown.

(2) Thickness Calculation Process Before Dressing In the present embodiment, after the holding process is performed, for example, the thickness value of the dressing board B is calculated. That is, as shown in FIG. 5, the height position Z1 of the holding surface 300a of the holding table 30 serving as the reference surface is measured by the first height measuring unit 381, and the dressing is performed by the second height measuring unit 382 The height position Z2 of the upper surface B1a of the board B is measured. Then, the thickness calculating means 37 calculates the difference (Z2-Z1) of the measured values of the two as the thickness value T1 of the dressing board B. Information on the thickness value of the dressing board B is transmitted from the thickness calculating means 37 to the control means 9 shown in FIG. 1 and stored in the storage unit 90.
Although the thickness calculation process before dressing does not necessarily need to be carried out, the worker performs the process of dressing board B by performing this process under the control of control means 9 according to the program configured based on the flowchart of FIG. Even if the thickness is not input to the grinding device 1, the grinding device 1 is in a state where the thickness of the dressing board B before dressing is grasped.

(3) Dressing Process As shown in FIG. 6, the holding table 30 is moved in the + X direction below the grinding means 6 by the X axis direction feeding means (not shown), and the dressing held by the grinding wheel 64 and the holding table 30 Alignment with board B is made.
After the alignment between the grinding wheel 64 and the dressing board B is performed, as the rotary shaft 60 is rotationally driven by the motor 62 (see FIG. 2), the grinding wheel 64 is a counterclockwise as viewed from the + Z direction side. Rotate around. The grinding feed means 7 lowers the grinding means 6 in the -Z direction from a position slightly above the top surface B1a of the dressing board B held by the holding surface 300a of the holding table 30, and the grinding wheel 641 serves as the dressing By contacting the top surface B1a of the board B, dressing of the grinding surface of the grinding wheel 641 is performed. During dressing, as the holding table 30 is rotated counterclockwise as viewed from the + Z direction side by the rotation means 32, the dressing board B is also rotated, so that the grinding stone 641 is on the entire upper surface B1a of the dressing board B. Grinding process. Further, the height position of the descending grinding means 6 is sequentially recognized by the position recognition means 18 shown in FIG. 2, and information on the height position of the grinding means 6 is sequentially transmitted to the control means 9.

  When the grinding means 6 is lowered by a predetermined amount in the -Z direction by the grinding feed means 7 and dressing of the grinding surface of the grinding wheel 641 is finished as shown in FIG. 7, the grinding means 6 is raised in the + Z direction by the grinding feed means 7 And separate from the dressing board B. In addition, the storage unit 90 of the control means 9 stores the height position Z3 of the grinding means 6 at the end of the dressing process, which is recognized by the position recognition means 18 shown in FIG.

(4) Dressing Post-Thickness Calculation Step After the dressing step is performed as described above, the rotation means 32 stops the rotation of the holding table 30. Next, the height position Z1 of the holding surface 300a of the holding table 30 serving as the reference surface is measured by the first height measuring means 381, and the second height measuring means 382 measures the height B1a of the upper surface B1a of the dressing board B. The height position Z4 is measured. Then, the thickness calculating means 37 calculates the difference (Z4-Z1) of the measured values of the two as the thickness value T2 of the dressing board B. Information on the thickness value T2 of the dressing board B is transmitted from the thickness calculation means 37 to the control means 9 shown in FIG. 1 and stored in the storage unit 90.

(5) Set-up step In order to control the amount of grinding when grinding the workpiece W shown in FIG. 1, the holding table 30 and the grinding surface which is the tip of the grinding wheel 641 make contact in the grinding feed direction (Z axis direction). It is called setting up to recognize the height position to do. The control means 9 includes the calculation unit 91 shown in FIG. 1, and the calculation unit 91 measures the thickness value of the dressing board B after dressing from the height position Z3 of the grinding means 6 at the end of the dressing process shown in FIG. The height position Z5 is calculated by subtracting T2. The calculated height position Z5 is stored in the storage unit 90 of the control unit 9 as a height position at which the grinding surface of the grinding wheel 641 contacts the holding surface 300a of the holding table 30 when the grinding unit 6 is lowered. (Set up). In addition, the grinding means 6 shown with a dashed-two dotted line in FIG. 8 has shown the state at the time of moving the grinding means 6 temporarily to the height position Z5, and the dressing board B is abbreviate | omitted and shown.

  As described above, in the dressing method according to the present invention, the grinding process is performed from the position slightly above the upper surface B1a of the dressing board B held by the holding table 30 and the holding step of holding the dressing board B Holding down the holding table 30 by stopping the rotation of the holding table 30 and stopping the rotation of the holding table 30 after the dressing process and the dressing process in which the dressing board B is ground on the grinding surface of the grinding wheel 641 by fixed amount lowering The difference (Z4-Z1) between the height position Z1 of the surface 300a and the height position Z4 of the top surface B1a of the dressing board B held by the holding surface 300a measured by the second height measuring means 382 is the thickness of the dressing board B Thickness after dressing process calculated as height value T2 and height of grinding means 6 at the end of the dressing process The height at which the grinding surface of the grinding wheel 641 contacts the holding surface 300a of the holding table 30 when lowering the grinding means 6 at the height position Z5 obtained by subtracting the thickness value T2 of the dressing board B after dressing from the position Z3. Since the grinding device 1 automatically performs the setup operation of storing the height position of the grinding means 6 with which the grinding surface comes in contact with the holding surface 300a after dressing, since the setup step of storing the position as Can be And since the setup is completed automatically after dressing, it becomes possible to carry out grinding of the subsequent workpiece W smoothly and continuously.

Second Embodiment
Below, each step in the case of grinding the to-be-processed object W shown in FIG. 1 to predetermined | prescribed thickness is demonstrated, implementing the dressing method which concerns on this invention. The steps of the dressing method in the present embodiment are performed in the order shown in the flowchart shown in FIG.

  The workpiece W shown in FIG. 1 is, for example, a semiconductor wafer whose base material is composed of a difficult abrasive material such as LT (lithium tantalate) or sapphire and whose outer shape is a circular plate shape, and is directed upward in FIG. The upper surface Wb where it is located becomes the surface to be ground. In the lower surface Wa of the workpiece W facing downward in FIG. 1, a plurality of devices are formed in the area divided by the planned dividing line, and a protective tape (not shown) is adhered and protected. The workpiece W is not limited to the example shown in the present embodiment.

(1) Grinding Step In the present embodiment, first, a grinding step of grinding the workpiece W is performed. In the mounting / removing area of the grinding apparatus 1 shown in FIG. 1, the workpiece W is placed on the holding surface 300a of the holding table 30 such that the upper surface Wb is on the upper side by the loading / unloading unit (not shown). Then, the suction force generated by a suction source (not shown) is transmitted to the holding surface 300a, whereby the holding table 30 sucks and holds the workpiece W on the holding surface 300a.

  The holding table 30 is moved in the + X direction below the grinding means 6 by an X-axis direction feeding means (not shown) to align the grinding wheel 64 with the workpiece W held by the holding table 30. For alignment, for example, as shown in FIG. 10, the rotation center of the grinding wheel 64 is shifted in the + X direction by a predetermined distance with respect to the rotation center of the workpiece W, and the rotation trajectory of the grinding wheel 641 is of the workpiece W It is done to pass through the rotation center. In addition, the inclination of the holding table 30 is adjusted by the inclination adjusting unit 35 such that the holding surface 300a which is a very gentle conical surface is parallel to the grinding surface (lower surface) of the grinding wheel 641. The upper surface Wb of the workpiece W suctioned and held along the holding surface 300a, which is a surface, is parallel to the grinding surface of the grinding wheel 641.

  After the alignment between the grinding wheel 64 and the workpiece W is performed, as the rotary shaft 60 is driven to rotate, the grinding wheel 64 rotates counterclockwise as viewed from the + Z direction side. In addition, the grinding feed means 7 lowers the grinding means 6 in the −Z direction, and the grinding wheel 641 abuts on the upper surface Wb of the workpiece W, whereby the grinding process is performed. During grinding, the workpiece W rotates as the holding table 30 rotates counterclockwise as viewed from the + Z direction side, so that the grinding wheel 641 performs grinding on the entire upper surface Wb of the workpiece W. I do.

During the grinding process, the first height measuring means 381 measures the height position of the holding surface 300 a of the holding table 30 as the reference plane, and the second height measuring means 382 The height position of the upper surface Wb of the workpiece W to be ground is measured. Then, the thickness calculating means 37 sequentially calculates the difference between the two measured values as the thickness value of the workpiece W. Information on the thickness value of the workpiece W is sequentially transmitted from the thickness calculating means 37 to the control means 9.
Further, the height position of the descending grinding means 6 is successively recognized by the position recognition means 18 shown in FIG. 2, and information on the height position of the grinding means 6 is sequentially transmitted to the control means 9.

  When the workpiece W is ground to a desired thickness (for example, T3 shown in FIG. 10) while the thickness calculation is performed by the thickness calculation means 37, the grinding feed means is controlled under the control of the control means 9. 7 raises the grinding means 6 and the grinding of the workpiece W is completed. In addition, the rotation of the holding table 30 is stopped.

(2) Memory process The thickness of the workpiece W at the end of the grinding process from the height position Z6 of the grinding means 6 at the end of the grinding process shown in FIG. 10 by the calculation unit 91 of the control means 9 shown in FIG. The height position Z7 obtained by subtracting the value T3 is calculated. The calculated height position Z7 is a height at which the grinding surface of the grinding wheel 641 contacts the holding surface 300a of the holding table 30 when the grinding means 6 located at the height position Z6 is temporarily lowered further at the end of the grinding process. The position is recognized as a position and stored in the storage unit 90 of the control means 9.

(3) Holding Step The holding table 30 whose rotation has been stopped is moved in the −X direction by the X-axis direction feeding means (not shown), and returns to the mounting / removing area of the grinding apparatus 1 shown in FIG. After the workpiece W after grinding is unloaded from the holding table 30 by the loading / unloading unit (not shown) in the mounting / removing area of the grinding apparatus 1, the holding table 30 is held such that the dressing board B is on the upper surface B1a. It is placed on the surface 300 a and held by suction. Further, the top surface B1a of the dressing board B suctioned and held along the holding surface 300a, which is a conical surface, becomes parallel to the grinding surface of the grinding stone 641 by the inclination adjustment by the inclination adjusting unit 35.

(4) Pre-dressing thickness calculation step As shown in FIG. 11, the holding table 30 is moved in the + X direction below the first height measurement means 381 and is made the reference surface by the first height measurement means 381. The height position Z8 of the holding surface 300a of the holding table 30 is measured, and the height position Z9 of the top surface B1a of the dressing board B is measured by the second height measuring means 382. The thickness calculating means 37 calculates the difference (Z9-Z8) between the two measured values as the thickness value T4 of the dressing board B, and sends information on the thickness value T4 to the control means 9 shown in FIG.

(5) Starting position calculation process The height position Z7 of the grinding means 6 stored in the storage unit 90 by the calculation unit 91 of the control means 9 shown in FIG. 1 in (2) storage process (4) Thickness calculation process before dressing The height position Z10 (see FIG. 12) is calculated by adding the thickness value T4 of the dressing board B calculated in the above, and the control means 9 recognizes the height position Z10 as the height position at which dressing of the grinding stone 641 starts. Do. Then, under the control of the control means 9, the grinding feed means 7 moves the grinding means 6 in the Z-axis direction, and for example, the grinding means 6 is positioned slightly above the height position Z10.

(6) Dressing Process The holding table 30 is moved, and alignment in the direction of the holding surface 300 a between the grinding wheel 64 and the dressing board B held by the holding table 30 is performed. The grinding means 6 is positioned slightly above the height position Z10 by the grinding feed means 7 under the control of the control means 9, ie, slightly above the upper surface B1a of the dressing board B held by the holding surface 300a of the holding table 30. Since the grinding feed means 7 lowers the grinding means 6 from this position in the -Z direction, the grinding wheel has almost no waiting time associated with the lowering of the grinding means 6. The ground surface 641 abuts on the top surface B1a of the dressing board B at the height position Z10, and dressing of the grinding wheel 641 is performed smoothly.

  During dressing, as the holding table 30 is rotated counterclockwise as viewed from the + Z direction side by the rotation means 32, the dressing board B is also rotated, so that the grinding stone 641 is on the entire upper surface B1a of the dressing board B. Grinding process. Further, the height position of the descending grinding means 6 is sequentially recognized by the position recognition means 18 shown in FIG. 2, and information on the height position of the grinding means 6 is sequentially transmitted to the control means 9.

  As shown in FIG. 13, when the grinding means 6 is lowered by a predetermined amount in the -Z direction by the grinding feed means 7 and dressing of the grinding surface of the grinding wheel 641 is finished, the grinding means 6 is raised by the grinding feed means 7 in the + Z direction. And separate from the dressing board B. In addition, the storage unit 90 of the control means 9 stores the height position Z11 of the grinding means 6 at the end of the dressing process, which is recognized by the position recognition means 18 shown in FIG.

(7) Dressing Post-Thickness Calculation Step After the dressing step is performed as described above, the rotation means 32 shown in FIG. 13 stops the rotation of the holding table 30. Next, the height position Z8 of the holding surface 300a of the holding table 30, which is the reference surface, is measured by the first height measuring means 381, and the second height measuring means 382 measures the top surface B1a of the dressing board B. The height position Z12 is measured. Then, the thickness calculating means 37 calculates the difference (Z12−Z8) of the measured values of the two as the thickness value T5 of the dressing board B. Information on the thickness value T5 of the dressing board B is transmitted from the thickness calculation means 37 to the control means 9 shown in FIG. 1 and stored in the storage unit 90.

(8) Set-up Step The calculation unit 91 of the control unit 9 calculates the height position Z13 (see FIG. 14) by subtracting the thickness value T5 of the dressing board B after dressing from the height position Z11 of the grinding unit 6 at the end of the dressing step. Calculate). The calculated height position Z13 is stored in the storage unit 90 of the control unit 9 as the height position at which the grinding surface of the grinding wheel 641 contacts the holding surface 300a of the holding table 30 when the grinding unit 6 is lowered. . That is, the grinding apparatus 1 is in a state where the setup for holding and grinding the next workpiece W on the holding table 30 is performed. In addition, the grinding means 6 shown with a dashed-two dotted line in FIG. 14 has shown the state at the time of moving the grinding means 6 temporarily to height position Z13, and the dressing board B is abbreviate | omitted and shown.

  Thus, the dressing method according to the present invention is measured by the first height measuring means 381 when rotating the holding table 30 and grinding the workpiece W held by the holding table 30 with the grinding wheel 641. The difference between the height position of the holding surface 300a and the height position of the upper surface Wb of the workpiece W measured by the second height measuring means 382 is calculated as the thickness value of the workpiece W and the grinding means 6 Grinding process at the end of the grinding process by subtracting the thickness value T3 of the workpiece W at the end of the grinding process from the grinding process to recognize the height position and the height position Z6 of the grinding means 6 at the end of the grinding process A storage step of calculating and storing the height position Z7 of the grinding means 6 in which the grinding surface of the grindstone 641 contacts the holding surface 300a, and stopping the rotation of the holding table 30 after the holding step and before the dressing step Height of Difference between the height position of the holding surface 300a measured by the fixing means 381 and the height position Z9 of the upper surface B1a of the dressing board B held by the holding surface 300a measured by the second height measuring means 382 (Z9-Z8) Thickness value of the dressing board B calculated as the thickness value T4 of the dressing board B, and the thickness value of the dressing board B calculated in the thickness calculation process before dressing at the height position Z7 of the grinding means 6 stored in the storage step A grinding process is performed during continuous grinding of the workpiece W by providing a start position calculation step of setting the height position Z10 to which T4 is added to the height position to start dressing of the grinding stone 641. The device 1 enables dressing of the grinding wheel 641 to be performed automatically. Therefore, continuous grinding of the workpiece W by the grinding wheel 641 becomes possible.

1: Grinding device 10: Base 17: Column 18: Position recognition means 180: Scale 181: Reading unit 30: Holding table 300: Adsorption unit 300a: Holding surface 301: Frame body 39: Cover 32: Rotation means 35: Inclination adjustment unit 381: first height measurement means 382: second height measurement means 37: thickness calculation means 6: grinding means 60: rotating shaft 61: housing 62: motor 63: mount 64: grinding wheel 640: wheel base 641: Grinding wheel 7: Grinding feed means 9: Control means 90: Storage unit 91: Calculation unit W: Workpiece B: Dressing board

Claims (2)

A holding table holding a dressing board consisting of a plate-like grinding wheel is rotated about the center of the holding surface as an axis, and a grinding wheel on which a grinding wheel is disposed annularly is rotated about the grinding wheel center, and the holding table is held. A dressing method for contacting a grinding surface of a grinding wheel with a dressing board and dressing the grinding surface,
A holding step of holding the dressing board on the holding table;
A dressing process in which the grinding means is lowered by a predetermined amount from a position slightly above the upper surface of the dressing board held by the holding surface, and the dressing board is ground on the grinding surface;
After the dressing step, the rotation of the holding table is stopped and the height position of the holding surface of the holding table measured by the height measuring means and the height position of the upper surface of the dressing board held by the holding surface A post dressing thickness calculation step of calculating the difference as the thickness value of the dressing board;
When the grinding means is lowered from the height position of the grinding means at the end of the dressing step after subtracting the thickness value of the dressing board after dressing, the grinding surface contacts the holding surface And d. Setting up stored as height position. The height position of the holding surface of the holding table and the workpiece measured by the height measuring means when the workpiece held by the holding table is rotated by the holding table by rotating the holding table A grinding process step of calculating the difference between the upper surface and the height position as the thickness value of the workpiece and recognizing the height position of the grinding means;
The grinding surface contacts the holding surface at the end of the grinding process by subtracting the thickness value of the workpiece at the end of the grinding process from the height position of the grinding means at the end of the grinding process. A storage step of calculating and storing the height position of the grinding means;
After the holding step and before the dressing step, the rotation of the holding table is stopped to measure the height position of the holding surface measured by the height measuring means and the height of the upper surface of the dressing board held by the holding surface. Pre-dressing thickness calculation step of calculating the difference between the position and the thickness as the thickness value of the dressing board;
The height position obtained by adding the thickness value of the dressing board calculated in the pre-dressing thickness calculation step to the height position of the grinding means stored in the storage step is the height position at which dressing of the grinding wheel is started And a start position calculating step.

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