Machining device

Abstract

To even out the deterioration of multiple installed check tables.SOLUTION: A machining device 1 includes: at least two or more chuck tables 10 each holding a workpiece 100: at least one machining unit which machines a workpiece 100 held on the chuck table 10; and a control unit 60 which controls each component. The control unit 60 includes: a usage count memory unit 61 which stores, for each chuck table 10, the number of times that the chuck table has been used when the machining unit machines the workpiece 100; and a chuck table selection unit 62 which selects the chuck table 10 to be used on the basis of the number of times that each chuck table 10 has been used stored in the usage count memory unit 61.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a processing device. [Background technology]

[0002] A workpiece on which multiple devices such as LC and LSI are formed is ground at the back surface to a predetermined thickness, and is divided into individual devices by a dividing device such as a dicing device to be used in electronic devices such as mobile phones and personal computers. For example, in a grinding device, the upper surface of a wafer is ground by a grinding unit equipped with a grinding wheel that forms a ring shape with a grinding wheel while supplying grinding water to the upper surface of the wafer. In such a grinding device, a grinding unit for rough grinding and a grinding unit for finish grinding are installed to improve productivity. Patent Document 1 discloses a grinding device equipped with a turntable equipped with multiple chuck tables that hold wafers, and the positions of the multiple chuck tables are changed by rotating the turntable. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2000-288881 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a grinding device equipped with multiple chuck tables, each table is assigned a serial number or A, B, C, etc., and managed within the device. In that case, when processing is performed with the grinding device, the tables are used in the order of the assigned numbers. Therefore, when the number of processed sheets is not divisible by the number of chuck tables, or when processing one sheet, chuck tables managed with smaller numbers are used more frequently and deteriorate faster. The smaller number means the smaller number among the numbers. Deterioration in a grinding device includes, for example, changes in vacuum force due to clogging, dirt, etc. When a chuck table deteriorates due to clogging, etc., self-grinding is performed when replacing it. In self-grinding, which directly grinds the chuck table to maintain the shape of the upper surface of the chuck table, all chuck tables are ground, so if there is variation in the deterioration of the chuck tables, chuck tables that are not deteriorated are also ground, reducing work efficiency. In addition, if there is variation in the deterioration of multiple chuck tables in a processing device, the number of times self-grinding is performed increases, reducing the productivity of the device.

[0005] The present invention has been made in view of the above, and an object of the present invention is to provide a processing device that can equalize the deterioration of a plurality of check tables mounted thereon. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the object, the processing apparatus of the present invention is a processing apparatus comprising at least two or more chuck tables for holding a workpiece, a processing unit for processing the workpiece held on the chuck tables, and a control unit for controlling each component, wherein the control unit comprises a usage count memory unit for storing, for each chuck table, the number of times that the chuck table has been used when processing the workpiece by the processing unit, and a chuck table selection unit for selecting a chuck table to be used based on the number of times that each chuck table has been used stored in the usage count memory unit.

[0007] In the processing device, the chuck table selection unit may select the chuck table that has been used the least number of times from the number of times each chuck table has been used stored in the number of times of use memory unit, thereby achieving uniformity of the number of times each chuck table has been used. Effect of the Invention

[0008] The present invention has an effect of enabling a plurality of installed check tables to be used equally. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing a configuration example of a processing device according to an embodiment. [Diagram 2] FIG. 2 is a cross-sectional view showing a main part of the processing apparatus of FIG. [Diagram 3] FIG. 3 is a diagram showing an example of the relationship between the number of times each of the three chuck tables is used and the number of sheets machined. [Figure 4] FIG. 4 is a flowchart showing an example of a process procedure related to the selection method executed by the processing device 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the contents described in the following embodiment. Furthermore, the components described below include those that a person skilled in the art can easily imagine and those that are substantially the same. Furthermore, the configurations described below can be appropriately combined. Furthermore, various omissions, substitutions, or modifications of the configurations can be made without departing from the gist of the present invention.

[0011] In the embodiment described below, an XYZ Cartesian coordinate system is set, and the positional relationship of each part is described with reference to this XYZ Cartesian coordinate system. One direction in a horizontal plane is the X-axis direction, a direction perpendicular to the X-axis direction in the horizontal plane is the Y-axis direction, and a direction perpendicular to both the X-axis direction and the Y-axis direction is the Z-axis direction. The XY plane including the X-axis and Y-axis is parallel to the horizontal plane. The Z-axis direction perpendicular to the XY plane is the vertical direction.

[0012] [Embodiment] A processing device according to an embodiment will be described with reference to the drawings. Fig. 1 is a perspective view showing a configuration example of the processing device according to an embodiment. Fig. 2 is a cross-sectional view showing a main part of the processing device of Fig. 1.

[0013] As shown in FIG. 1, the processing device 1 is a device that processes a workpiece 100. In this embodiment, the processing device 1 is described as a grinding device that grinds the workpiece 100, but is not limited to this. The processing device 1 can be realized as a device equipped with a plurality of chuck tables 10 that hold the workpieces 100. The processing device 1 has a self-grinding function that directly grinds the chuck table 10 in order to maintain the shape of the upper surface of the chuck table 10. The processing device 1 performs self-grinding when replacing the chuck table or to maintain the grinding shape.

[0014] In this embodiment, the workpiece 100 is a wafer such as a disk-shaped semiconductor wafer or an optical device wafer, using, for example, silicon, sapphire, silicon carbide (SiC), or gallium arsenide as a substrate. The workpiece 100 has a flat surface, and chip-shaped devices are formed in each region partitioned by planned division lines that intersect with each other (in this embodiment, perpendicular to each other). The back surface of the back side of the front surface of the workpiece 100 is ground to thin it to a predetermined thickness, and then the workpiece 100 is divided along the planned division lines by a cutting device or the like to manufacture individual semiconductor device chips. The workpiece 100 is not limited to this in the present invention, and may be a disk-shaped package substrate having a plurality of devices sealed with resin, a ceramic plate, a glass plate, or the like.

[0015] The processing apparatus 1 includes a plurality of chuck tables 10, a turntable 20, a first grinding unit 30, a second grinding unit 40, a contact-type thickness measurement unit 50, and a control unit 60. In this embodiment, the processing apparatus 1 further includes cassettes 71, 72, an alignment unit 73, a carry-in unit 74, an unloading unit 75, a cleaning unit 76, and a carry-in / out unit 77. In this embodiment, the first grinding unit 30 and the second grinding unit 40 of the processing apparatus 1 correspond to the processing units, but a configuration in which either one of the units corresponds to the processing unit may be used.

[0016] As shown in FIG. 2, the chuck table 10 includes a disk-shaped frame 11 having a recess and a disk-shaped suction portion 12 fitted into the recess. The suction portion 12 of the chuck table 10 is made of porous ceramics or the like having a large number of porous holes, and is connected to a vacuum suction source (not shown) via a vacuum suction path (not shown). The upper surface of the suction portion 12 of the chuck table 10 is a holding surface 13 that holds the placed workpiece 100 by suction from below. In this embodiment, the upper surface of the frame 11 and the holding surface 13 are formed into a cone shape with a slightly lower outer periphery, with the center 13-1 of the holding surface 13 of the chuck table 10 as the apex. Note that the holding surface 13 is not limited to this in the present invention, and may be formed flat.

[0017] An annular bearing 14 that supports the chuck table 10 is provided below the chuck table 10, and an annular support plate 15 is fixed below the annular bearing 14. The bearing 14 supports the chuck table 10 rotatably relative to the support plate 15. An annular table base 16 is provided below the support plate 15.

[0018] The chuck table 10 is provided so as to be rotatable independently of the turntable 20 by a rotation drive source 17 about a predetermined rotation axis that passes through the center 13-1 of the holding surface 13 and is perpendicular to the bottom surface of the cone that forms the holding surface 13. The rotation drive source 17 is positioned in openings provided in the centers of the bearing 14, the support plate 15, and the table base 16, and is connected to the lower side of the frame 11 of the chuck table 10.

[0019] A load sensor 18 is provided between the support plate 15 and the table base 16. The load sensors 18 are provided at a plurality of locations (e.g., three locations) at equal intervals (e.g., 120 degrees) along the circumferential direction of the holding surface 13 of the chuck table 10. The load sensor 18 measures the load applied to the chuck table 10 and outputs the measured load to the control unit 60. The load sensor 18 measures the grinding load applied to the chuck table 10 during grinding by the first grinding unit 30 or the second grinding unit 40 and outputs the measured grinding load to the control unit 60.

[0020] A rotation axis adjustment unit 19 that tilts the rotation axis of the chuck table 10 with respect to the Z-axis direction parallel to the vertical direction is provided below the table base 16. The rotation axis adjustment unit 19 allows the rotation axis of the chuck table 10 to be tilted by an inclination angle within a predetermined range with respect to the Z-axis direction parallel to the vertical direction, and accordingly, the holding surface 13 can be tilted by the same inclination angle with respect to the horizontal plane parallel to the XY plane, in which the bottom surface of the cone that forms the holding surface 13 is formed.

[0021] As shown in FIG. 1, the processing apparatus 1 according to the embodiment is provided with three chuck tables 10. The three chuck tables 10 are arranged on a disk-shaped turntable 20 that is larger than the chuck table 10 in a plan view, at equal intervals, for example, at a phase angle of 120°. The number of chuck tables 10 is not limited to this in the present invention, and may be two or four or more. The turntable 20 is provided rotatably in a horizontal plane and is rotated at a predetermined timing. The three chuck tables 10 are sequentially moved to a loading / unloading position 201, a first grinding position 202, a second grinding position 203, and a loading / unloading position 201 by the rotation of the turntable 20.

[0022] The first grinding unit 30 includes a first spindle 31, a first grinding wheel 32, and a first grinding feed unit 34. The first spindle 31 is provided rotatably about an axis parallel to the vertical direction (Z-axis direction), and supports the first grinding wheel 32 detachably attached to the lower end thereof rotatably about an axis parallel to the vertical direction. The first grinding wheel 32 has a first grinding stone 33 arranged in an annular shape on its lower surface.

[0023] The first grinding unit 30 is disposed such that the first spindle 31 faces in the vertical direction the holding surface 13 of the chuck table 10 positioned at the first grinding position 202. The first grinding feed unit 34 moves the first spindle 31 of the first grinding unit 30 and the first grinding wheel 32 attached to the first spindle 31 relative to the chuck table 10 positioned at the first grinding position 202 along the grinding feed direction (the Z-axis direction parallel to the vertical direction), thereby moving the first spindle 31 and the first grinding wheel 32 closer to and farther away from the chuck table 10 positioned at the first grinding position 202 relative to each other along the grinding feed direction.

[0024] The first grinding unit 30 rotates the first spindle 31 around an axis parallel to the vertical direction, thereby rotating the first grinding wheel 32 attached to the lower end of the first spindle 31 around an axis parallel to the vertical direction, and rotates the chuck table 10, which is positioned at the first grinding position 202 and opposed to the first spindle 31 and holds the workpiece 100, around the rotation axis. In this state, the first grinding feed unit 34 presses the rotating first grinding wheel 32 along the grinding feed direction while supplying a grinding fluid to the workpiece 100 held on the rotated chuck table 10 from a grinding fluid supply unit (not shown), thereby grinding the workpiece 100 with the first grinding stone 33 of the first grinding wheel 32. The first grinding wheel 32 grinds the workpiece 100 along the grinding surface to form the grinding surface of the workpiece 100 parallel to the grinding surface.

[0025] 1 and 2, the second grinding unit 40 includes a second spindle 41, a second grinding wheel 42, a second grinding feed unit 44, a grinding fluid supply unit 45, a load current value detection sensor 46, and a load sensor 48. The second spindle 41 is provided rotatably about an axis parallel to the vertical direction, and supports the second grinding wheel 42 detachably attached to the lower end thereof rotatably about an axis parallel to the vertical direction. The second grinding wheel 42 has a second grinding stone 43 arranged in an annular shape on its lower surface.

[0026] The second grinding unit 40 is disposed such that the second spindle 41 faces in the vertical direction the holding surface 13 of the chuck table 10 positioned at the second grinding position 203. The second grinding feed unit 44 performs grinding feed to relatively move the second spindle 41 of the second grinding unit 40 and the second grinding wheel 42 attached to the second spindle 41 along the grinding feed direction relative to the chuck table 10 positioned at the second grinding position 203, thereby moving the second spindle 41 and the second grinding wheel 42 closer to and farther away from the chuck table 10 positioned at the second grinding position 203 along the grinding feed direction.

[0027] The second grinding feed unit 44 is a known ball screw mechanism having a motor, a ball screw, and a guide, similar to the first grinding feed unit 34. The second grinding feed unit 44 is configured to have a ball screw provided rotatably around the axis of the Z axis, a motor for rotating the ball screw around the axis, and a guide for supporting the second spindle 41 movably in the Z axis direction. The second grinding feed unit 44 has a feed speed, a movement amount, and the like controlled by the control unit 60 controlling the driving of the motor. Here, the feed speed refers to the speed at which the second grinding feed unit 44 moves the second spindle 41 and the second grinding wheel 42 relatively close to and away from the chuck table 10 positioned at the second grinding position 203 along the Z axis direction. The movement amount refers to the amount (height) by which the second grinding feed unit 44 moves the second spindle 41 and the second grinding wheel 42 relatively toward and away from the chuck table 10 positioned at the second grinding position 203 along the Z-axis direction. The feed speed is the movement amount per unit time.

[0028] The second grinding feed unit 44 includes an encoder that reads the rotational position of the motor, and detects the relative position in the Z-axis direction with respect to the chuck table 10 positioned at the second grinding position 203 of the second spindle 41 based on the rotational position of the motor read by the encoder, and outputs the detected relative position to the control unit 60. Here, for the relative position in the Z-axis direction, an apparatus orthogonal coordinate system (XYZ coordinates) provided in the processing apparatus 1 is used. For example, the center of the turntable 20 is set as the origin of the apparatus orthogonal coordinate system. In addition, the second grinding feed unit 44 detects the feed speed and the movement amount by detecting the relative position in the Z-axis direction with respect to the chuck table 10 positioned at the second grinding position 203 of the second spindle 41, for example, at regular time intervals (for example, every second) before the start of grinding, during grinding, and after the end of grinding, and outputs the detected feed speed and the movement amount to the control unit 60. In addition, the second grinding feed unit 44 is not limited to a configuration in which an encoder detects the relative position in the Z-axis direction with respect to the chuck table 10 positioned at the second grinding position 203 of the second spindle 41, but may also be configured with a linear scale parallel to the Z-axis direction and a reading head that is freely movable in the Z-axis direction by the second grinding feed unit 44 and reads the graduations of the linear scale.

[0029] 2, the grinding fluid supply unit 45 supplies a grinding fluid such as pure water to the workpiece 100 held on the chuck table 10 positioned at the second grinding position 203. The load current value detection sensor 46 is connected to the spindle motor provided in the second spindle 41, and detects the load current value of the second spindle 41, which is the current value flowing through the spindle motor provided in the second spindle 41. The load current value of the second spindle 41 tends to increase as the grinding load and grinding resistance increase when the workpiece 100 is ground with the second grinding wheel 42.

[0030] A load sensor 48 is provided below the second spindle 41 between the second spindle 41 and a cover member covering the outer periphery of the second spindle 41. The load sensor 48 is provided at a plurality of locations (e.g., three locations) at equal intervals (e.g., 120 degrees) along the circumferential direction of the second grinding wheel 42 attached to the second spindle 41. The load sensor 48 measures the load applied to the second spindle 41 to which the second grinding wheel 42 is attached, and outputs the measured load to the control unit 60. The load sensor 48 measures the grinding load applied to the second spindle 41 to which the second grinding wheel 42 is attached during grinding by the second grinding unit 40, and outputs the measured grinding load to the control unit 60.

[0031] In this embodiment, the second grinding wheel 42 has a smaller grain size than the first grinding wheel 32. That is, the grain size of the abrasive grains forming the second grinding stone 43 annularly arranged on the second grinding wheel 42 is smaller than the grain size of the abrasive grains forming the first grinding stone 33 annularly arranged on the first grinding wheel 32. Here, both the first grinding stone 33 annularly arranged on the first grinding wheel 32 and the second grinding stone 43 annularly arranged on the second grinding wheel 42 are formed by fixing abrasive grains such as diamond, cBN (cubic boron nitride), etc., with a bond material (binding material) such as a metal bond, a resin bond, or a vitrified bond.

[0032] There are known methods for expressing the grain size of the abrasive grains forming the first grinding wheel 33 and the second grinding wheel 43, such as the geometric diameter and the equivalent diameter. The geometric diameter includes the Feret diameter, the maximum diameter in a specific direction (i.e., the Krummbein diameter), the Martin diameter, the sieve diameter, etc., while the equivalent diameter includes the diameter equivalent to a circle with a projected area (i.e., the Heywood diameter), the diameter equivalent to a sphere with an equal surface area, the diameter equivalent to a sphere with an equal volume, the Stokes diameter, the light scattering diameter, etc. In addition, a small grain size of the abrasive grains means that the grain size of the abrasive grains is high. The grain size of the abrasive grains is a parameter that increases as the grain size decreases.

[0033] In the example shown in Fig. 1, the processing device 1 first performs rough grinding of the workpiece 100 by the first grinding unit 30 with the first grinding wheel 32 having the first grinding wheels 33 arranged in an annular shape, the grinding wheels having a larger grain size than the second grinding wheels 43. Next, the processing device 1 performs damage grinding, which grinds a grinding damage layer formed by rough grinding, and finish grinding of the workpiece 100 by the second grinding unit 40 with the second grinding wheel 42 having the second grinding wheels 43 arranged in an annular shape, the grinding wheels having a smaller grain size than the first grinding wheels 33.

[0034] 1, the contact type thickness measurement units 50 are provided at two locations, near the first grinding position 202 and near the second grinding position 203. The two contact type thickness measurement units 50 have the same configuration and the same functions, except for the locations where they are provided. The contact type thickness measurement units 50 include a first probe 51 and a second probe 52. In this embodiment, the first probe 51 and the second probe 52 are both contact type probes that measure the height of the position they come into contact with.

[0035] The first probe 51 comes into contact with the outside of the workpiece 100 on the holding surface 13 of the chuck table 10 holding the workpiece 100, thereby measuring the position of the holding surface 13 in the Z-axis direction, i.e., the height of the holding surface 13. The second probe 52 comes into contact with the top surface (surface to be ground) of the workpiece 100 held on the holding surface 13 of the chuck table 10, thereby measuring the position (top surface position) of the top surface of the workpiece 100 in the Z-axis direction, i.e., the height (top surface height) of the top surface of the workpiece 100. Both the first probe 51 and the second probe 52 output the measured position (height) results to the control unit 60. In addition, both the first probe 51 and the second probe 52 detect the height of the holding surface 13 of the chuck table 10 and the height of the top surface of the workpiece 100 before grinding begins, during grinding, and after grinding is completed, for example at regular intervals (for example, every second), to obtain the time changes in the height of the holding surface 13 and the time changes in the height of the top surface of the workpiece 100, and output these obtained time changes to the control unit 60.

[0036] The control unit 60 controls the operation of various components of the processing device 1, and causes the processing device 1 to perform the grinding process of the workpiece 100, the self-grinding of the chuck table 10, and the like. During the grinding of the workpiece 100 by the second grinding unit 40, the control unit 60 acquires the grinding load applied to the chuck table 10 by the load sensor 18 provided on the chuck table 10 positioned at the second grinding position 203, acquires the feed speed and movement amount of the second spindle 41 by the second grinding feed unit 44, acquires the load current value of the second spindle 41 by the load current value detection sensor 46, acquires the grinding load applied to the second spindle 41 to which the second grinding wheel 42 is attached by the load sensor 48, and acquires the time change in the height of the holding surface 13 and the time change in the height of the upper surface of the workpiece 100 by the contact type thickness measurement unit 50. The control unit 60 controls the feed speed and movement amount of the second spindle 41 by the second grinding feed unit 44.

[0037] The control unit 60 calculates the thickness of the workpiece 100 by subtracting the height of the holding surface 13 from the height of the upper surface of the workpiece 100 based on the height of the holding surface 13 and the height of the upper surface of the workpiece 100 acquired by the contact thickness measurement unit 50. The control unit 60 calculates the time change in the thickness of the workpiece 100 and the amount of change in the thickness of the workpiece 100 based on the time change in the height of the holding surface 13 and the time change in the height of the upper surface of the workpiece 100 acquired by the contact thickness measurement unit 50, and calculates the grinding amount of the workpiece 100 ground by the second grinding wheel 42 based on the calculated time change in the thickness of the workpiece 100 and the amount of change in the thickness of the workpiece 100. In this way, the control unit 60 can substantially measure the thickness of the workpiece 100, the time change in the thickness of the workpiece 100, and the amount of change in the thickness of the workpiece 100 by the contact thickness measurement unit 50.

[0038] The control unit 60 calculates the wear rate of the second grinding wheel 42 attached to the second spindle 41 by subtracting the change in thickness of the workpiece 100 from the movement amount of the second spindle 41 based on the movement amount of the second spindle 41 acquired by the second grinding feed unit 44 and the change in thickness of the workpiece 100 acquired by substantially measuring it using the contact type thickness measuring unit 50. The control unit 60 also calculates the wear rate of the second grinding wheel 42 attached to the second spindle 41 in a predetermined unit time by subtracting the change in thickness of the workpiece 100 per predetermined unit time from the movement amount of the second spindle 41 per predetermined unit time (for example, 1 second) based on the movement amount of the second spindle 41 acquired by the second grinding feed unit 44 and the change in thickness of the workpiece 100 acquired by substantially measuring it using the contact type thickness measuring unit 50, and dividing the subtracted value by the change in thickness of the workpiece 100 per predetermined unit time. Furthermore, the control unit 60 calculates a moving average of the wear rate of the second grinding wheel 42 per predetermined time (for example, 10 seconds) based on data on the change over time of the wear rate of the second grinding wheel 42 in a predetermined unit time.

[0039] The control unit 60 calculates a moving average of the grinding loads applied to the chuck table 10 and the second spindle 41 per predetermined time based on data of the change over time of the grinding loads applied to the chuck table 10 and the second spindle 41. The control unit 60 calculates a moving average of the load current value of the second spindle 41 per predetermined time based on data of the change over time of the load current value of the second spindle 41.

[0040] The control unit 60 performs self-grinding by grinding the holding surface 13 of the chuck table 10 with the first grinding unit 30 and the second grinding unit 40 to form a desired shape of the holding surface 13. In self-grinding, only either the first grinding unit 30 or the second grinding unit 40 may be used. The control unit 60 roughly grinds the holding surface 13 by pressing the first grinding unit 30 against the holding surface 13 of the chuck table 10, which has been positioned at the first grinding position 202 by rotating the turntable 20, while rotating the first grinding wheel 32 in a state in which nothing, including the workpiece 100, is suction-held on the holding surface 13 of the chuck table 10. Then, while the control unit 60 is not suction-holding anything, including the workpiece 100, on the holding surface 13 of the chuck table 10, the control unit 60 rotates the turntable 20 and presses the second grinding unit 40 against the holding surface 13 of the chuck table 10 positioned at the second grinding position 203 while rotating the second grinding wheel 42, thereby finish-grinding the holding surface 13. The control unit 60 may perform finish grinding after performing rough grinding on the holding surface 13 of the chuck table 10, or may perform only one of rough grinding and finish grinding on the holding surface 13.

[0041] In this embodiment, the control unit 60 includes a computer system. The computer system included in the control unit 60 includes an arithmetic processing device having a microprocessor such as a CPU (Central Processing Unit), a storage device having a memory such as a ROM (Read Only Memory) or a RAM (Random Access Memory), and an input / output interface device. The arithmetic processing device of the control unit 60 performs arithmetic processing according to a computer program stored in the storage device of the control unit 60, and outputs a control signal for controlling the processing device 1 to each component of the processing device 1 via the input / output interface device of the control unit 60.

[0042] The control unit 60 includes a usage count storage unit 61 and a chuck table selection unit 62. The usage count storage unit 61 stores, for each of the multiple chuck tables 10, the number of times the chuck table 10 has been used when machining the workpiece 100 in the machining unit. The usage count storage unit 61 stores a correspondence between the identification information of the multiple chuck tables 10 and the number of times the chuck tables 10 have been used.

[0043] Fig. 3 is a diagram showing an example of the relationship between the number of times three chuck tables are used and the number of sheets machined. In the example shown in Fig. 3, the processing device 1 manages three chuck tables 10-1, 10-2, 10-3 provided on the turntable 20 by assigning numbers thereto. When processing a plurality of workpieces 100, the processing device 1 uses the three chuck tables 10-1, 10-2, 10-3 in the order in which they are assigned numbers. The usage count storage unit 61 stores the three chuck tables 10-1, 10-2, 10-3 and the number of times they are used for each number of sheets machined. In this case, the processing device 1 rotates the turntable 20 to hold the workpiece 100 on the chuck tables 10-1, 10-2, and 10-3 in this order, and sequentially moves the chuck tables 10-1, 10-2, and 10-3 to the load / unload position 201, the first grinding position 202, the second grinding position 203, and the load / unload position 201. As a result, the processing device 1 sequentially processes the workpieces 100 held by the chuck tables 10-1, 10-2, and 10-3 and loads them into the cassettes 71 and 72.

[0044] For example, when the number of processed sheets is one, the use count storage unit 61 stores that the number of times the chuck table 10-1 has been used is one, and the number of times each of the chuck tables 10-2 and 10-3 has been used is zero. When the number of processed sheets is five, the use count storage unit 61 stores that the number of times each of the chuck tables 10-1 and 10-2 has been used is two, and the number of times each of the chuck table 10-3 has been used is one. When the number of processed sheets is 25, the use count storage unit 61 stores that the number of times the chuck table 10-1 has been used is nine, and the number of times each of the chuck tables 10-2 and 10-3 has been used is eight. In this way, when the processing device 1 processes the workpiece 100 using the three chuck tables 10-1, 10-2, and 10-3 in this order, the three chuck tables 10-1, 10-2, and 10-3 can be used evenly only when the number of processed sheets is divisible by three. Furthermore, when processing a single workpiece 100, the processing device 1 uses the chuck table 10-1, which is managed with a lower number, frequently, which can cause it to deteriorate quickly and can cause changes in the vacuum force of the chuck table 10 due to clogging, dirt, etc.

[0045] In this embodiment, the use count storage unit 61 is implemented as a storage device inside the control unit 60, but is not limited thereto. For example, the use count storage unit 61 may be implemented as an external storage device of the processing device 1 or the like that is accessible by the control unit 60.

[0046] The control unit 60 executes a program to realize a chuck table selection unit 62. The chuck table selection unit 62 selects a chuck table 10 to be used based on the number of times each chuck table 10 has been used stored in the number-of-uses storage unit 61. The chuck table selection unit 62 selects a chuck table 10 to be used in machining the workpiece 100 based on the number of times the chuck table 10 has been used. The selection of the chuck table 10 includes, for example, selecting the order in which the multiple chuck tables 10 are used, which chuck table 10 is to be used among the multiple chuck tables 10, which chuck table 10 is to be used first or last among the multiple chuck tables 10, etc.

[0047] The chuck table selection unit 62 selects a chuck table with the least number of uses from the number of uses of each of the chuck tables 10-1, 10-2, and 10-3 stored in the number-of-uses storage unit 61, thereby making the number of uses uniform among the multiple chuck tables 10-1, 10-2, and 10-3. The chuck table selection unit 62 may calculate the cumulative number of uses for each of the multiple chuck tables 10-1, 10-2, and 10-3. The chuck table selection unit 62 may calculate the number of uses or the cumulative number of uses since the previous selection for each of the multiple chuck tables 10-1, 10-2, and 10-3. The chuck table selection unit 62 may store the calculated number of uses, the cumulative number, etc. in the number-of-uses storage unit 61 in association with information capable of identifying the multiple chuck tables 10.

[0048] For example, when the number of workpieces 100 to be processed by the processing device 1 is less than the number of the multiple chuck tables 10, the chuck table selection unit 62 can select the chuck tables 10 to be used and the chuck tables 10 to be unused based on the number of times each chuck table 10-1, 10-2, 10-3 has been used, as stored in the number-of-use memory unit 61.

[0049] The cassettes 71 and 72 are containers for accommodating a plurality of workpieces 100. The alignment unit 73 is a table on which the workpieces 100 taken out of the cassettes 71 and 72 are temporarily placed and whose center is aligned.

[0050] The carry-in unit 74 has a suction pad, and suction-holds the unground workpiece 100 aligned by the alignment unit 73, and carries it onto the chuck table 10 positioned at the carry-in / carry-out position 201. The carry-out unit 75 suction-holds the ground workpiece 100 that is held on the chuck table 10 positioned at the carry-in / carry-out position 201, and carries it out to the cleaning unit 76. The cleaning unit 76 cleans the ground workpiece 100, and removes contamination such as grinding chips adhering to the ground surface.

[0051] The carry-in / out unit 77 is, for example, a robot pick equipped with a U-shaped hand, and adsorbs and holds the workpiece 100 with the U-shaped hand to transport the workpiece 100. Specifically, the carry-in / out unit 77 carries the workpiece 100 before grinding out of the cassettes 71, 72 to the alignment unit 73, and carries the workpiece 100 after grinding out of the cleaning unit 76 into the cassettes 71, 72.

[0052] The above describes an example of the configuration of the processing device 1 according to the embodiment. Note that the above configuration described with reference to Figs. 1 to 3 is merely an example, and the configuration of the processing device 1 according to the embodiment is not limited to the example. The functional configuration of the processing device 1 according to the embodiment can be flexibly modified according to the specifications and operation.

[0053] (How to select processing equipment) Next, an example of a selection method executed by the processing device 1 according to the embodiment will be described. Fig. 4 is a flowchart showing an example of a processing procedure related to the selection method executed by the processing device 1. The processing procedure shown in Fig. 4 is realized by the control unit 60 executing a program.

[0054] 4, the processing device 1 stores the number of times the multiple chuck tables 10 have been used (step 101). For example, the processing device 1 stores the number of times the multiple chuck tables 10 have been used and the number of processed workpieces 100 in association with each other in the number-of-uses storage unit 61. When the processing of step 101 ends, the processing device 1 advances the processing to step 102.

[0055] The processing device 1 selects the chuck table 10 that has been used least frequently from the number of times that the multiple chuck tables 10 have been used (step 102). For example, the processing device 1 selects the chuck table 10 that has been used least frequently from the number of times that each chuck table 10 has been used stored in the number-of-uses storage unit 61. For example, the processing device 1 selects the chuck table 10 that has been used least frequently from the number of times that it has been used (cumulative number) since the previous selection to the present time. For example, when there are multiple chuck tables 10 that have been used least frequently, the processing device 1 selects the chuck table 10 with the furthest number from the serial numbers of the multiple chuck tables. When the processing of step 102 ends, the processing device 1 advances the processing to step 103.

[0056] The processing device 1 determines the order of use of the multiple chuck tables 10 (step 103). For example, the processing device 1 sets the chuck table 10 selected in step 102 as the first chuck table 10, and determines the order of use of the multiple chuck tables 10 based on the rotation direction of the turntable 20. When the processing of step 103 ends, the processing device 1 ends the processing procedure shown in FIG.

[0057] The processing device 1 of this embodiment can execute a selection method based on the processing procedure shown in Fig. 4. The selection method is a selection method for a processing device 1 including at least two or more chuck tables 10 for holding a workpiece 100, a processing unit for processing the workpiece 100 held by the chuck table 10, and a control unit 60 for controlling each component. The selection method includes a use count storage step of storing the number of uses of the chuck table 10 used when processing the workpiece 100 by the processing unit in a use count storage unit 61 for each of the multiple chuck tables 10, and a chuck table selection step of selecting a chuck table 10 to be used based on the use count of each chuck table 10 stored in the use count storage unit 61. The selection method may further include a step of determining a use order of the multiple chuck tables 10.

[0058] (Example of processing equipment operation) Next, an example of the operation of the processing device 1 according to the embodiment will be described. As shown in Fig. 3, the processing device 1 processes 25 workpieces 100 by holding them on the chuck tables 10-1, 10-2, and 10-3 in this order. In this case, the processing device 1 stores in the usage count storage unit 61 that the number of times that the chuck table 10-1 has been used is 9 times, and the number of times that the chuck tables 10-2 and 10-3 have been used is 8 times, respectively. Based on the number of times that the chuck tables 10 have been used stored in the usage count storage unit 61, the processing device 1 selects the chuck tables 10-2 and 10-3 as the chuck tables 10 that have been used the least number of times.

[0059] Thereafter, when processing the next 25 workpieces 100, the processing device 1 determines to use the chuck table 10-2, which has the lowest number in the arrangement in the rotation direction of the turntable 20, for the first processing since the cumulative number of times of use of the selected chuck tables 10-2 and 10-3 is equal. Then, the processing device 1 performs processing by holding the workpieces 100 in the order of the chuck tables 10-2, 10-3, and 10-1. In this case, the processing device 1 stores in the usage count storage unit 61 that the number of times of use of the chuck table 10-2 is 9, and the number of times of use of the chuck tables 10-1 and 10-3 is 8, respectively.

[0060] Thereafter, when processing the next 25 workpieces 100, the processing device 1 determines to use the selected chuck table 10-3 for the first processing because the cumulative number of times of use of the chuck table 10-3 is less than that of the chuck table 10-1. Then, the processing device 1 performs processing by holding the workpieces 100 in the order of the chuck tables 10-3, 10-1, and 10-2. In this case, the processing device 1 stores in the usage count storage unit 61 that the number of times of use of the chuck table 10-3 is 9, and the number of times of use of the chuck tables 10-1 and 10-2 is 8, respectively. Thereafter, the processing device 1 selects the chuck table 10 to be used based on the number of times of use of each chuck table 10 stored in the usage count storage unit 61.

[0061] In this embodiment, the processing device 1 stores the number of times that the chuck table 10 has been used when processing the workpiece 100 in the usage count storage unit 61 for each of the multiple chuck tables 10, and can select a chuck table 10 to be used based on the number of times that each of the multiple chuck tables 10 has been used. In this way, the processing device 1 can equalize the number of times that each of the multiple chuck tables 10 has been used by selecting a chuck table 10 that has been used less frequently from among the multiple chuck tables 10. As a result, the processing device 1 can reduce the number of times that self-grinding, which grinds all of the chuck tables 10, is performed by equalizing the deterioration speed of the multiple chuck tables 10, thereby suppressing a decrease in productivity.

[0062] The processing device 1 can equalize the number of times of use among the multiple chuck tables 10-1, 10-2, and 10-3 by selecting the chuck table 10 with the least number of times of use from the number of times of use of each of the chuck tables 10-1, 10-2, and 10-3 stored in the number-of-use storage unit 61. In this way, the processing device 1 can equalize the number of times of use among the multiple chuck tables 10-1, 10-2, and 10-3, thereby making the deterioration rates of the multiple chuck tables 10 even more uniform.

[0063] In the above-described embodiment, the processing apparatus 1 has been described as having three chuck tables 10 mounted on the turntable 20, but the present invention is not limited to this. For example, the processing apparatus 1 may have a configuration in which multiple chuck tables 10 are directly mounted on the apparatus body, or movably mounted on a conveyor.

[0064] In the above embodiment, the processing device 1 is described as a grinding device that grinds the workpiece 100, but is not limited thereto. For example, the processing device 1 may be realized as various devices such as a cutting device equipped with a plurality of chuck tables 10, a laser beam irradiation device, a polishing device, a plasma etching device, and a cutting tool device. [Explanation of symbols]

[0065] 1 Processing equipment 10 Chuck table 11 Frame 12 Adsorption part 13 Holding surface 20 Turntable 30 First grinding unit 40 Second Grinding Unit 50 Contact thickness measurement unit 60 Control Unit 61 Usage count memory section 62 Chuck table selection section 71 Cassette 72 Cassette 73 Alignment unit 74 Loading Unit 75 Unloading unit 76 Cleaning Unit 77 Loading / unloading unit 100 Workpiece

Claims

1. At least two chuck tables for holding a workpiece; a processing unit that processes the workpiece held on the chuck table; A processing apparatus including a control unit for controlling each component, The control unit a usage count storage unit that stores, for each chuck table, the number of times that the chuck table has been used when processing the workpiece in the processing unit; a chuck table selection unit that selects a chuck table to be used based on the number of times each chuck table has been used, which is stored in the number-of-use storage unit; A processing apparatus comprising:

2. The processing apparatus according to claim 1, characterized in that the chuck table selection unit selects the chuck table with the least number of uses from the number of uses of each chuck table stored in the number of uses memory unit, thereby achieving uniformity of the number of uses among the multiple chuck tables.

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