Machining apparatus and abnormality determination method for machining apparatus

Abstract

To make it possible to improve processing accuracy of a workpiece by measuring a height position of a holding surface of a holding table.SOLUTION: A machining apparatus includes at least: a holding table having a holding surface for holding a workpiece; an inclination adjusting unit disposed below the holding table and having a fixed supporting portion and at least two movable supporting portions, the inclination adjusting unit being for adjusting an inclination of the holding table by the movable supporting portions; a measuring unit for measuring a height position of an upper surface of the holding table; and a control unit. The machining apparatus is configured so that the control unit has a determination unit for determining an abnormality based on a measured value to be measured by the measuring unit, the measuring unit has a first measuring unit and a second measuring unit for respectively measuring the height position of an upper surface of the holding table at positions above the at least two movable supporting portions, and the determination unit determines the abnormality by comparing a measured value of the first measuring unit with first reference height and comparing a measured value of the second measuring unit with second reference height respectively.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a processing apparatus having a holding table for holding a workpiece, and to a technique for improving the processing accuracy of the workpiece by adjusting the tilt of the holding table. [Background technology]

[0002] Silicon wafers, which have multiple IC, LSI, and other devices formed on their surface, have their back surfaces ground to a specified thickness, and then are separated into individual devices using a cutting machine for use in electrical equipment such as mobile phones and personal computers.

[0003] The grinding process for grinding the back surface of the wafer uses a known grinding device, and a grinding wheel is attached to the spindle of the grinding device to process the wafer to a predetermined thickness through rough grinding and finish grinding (see, for example, Patent Document 1).

[0004] In recent years, due to the miniaturization and high integration of semiconductor devices, there has been a demand for thinner wafers and higher precision in the finished thickness of wafers.

[0005] In order to achieve high precision in the finished thickness and surface shape of wafers, grinding machines that can finely adjust the tilt of the holding table (chuck table) of the grinding machine have been put into practical use (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-288881 [Patent Document 2] Japanese Patent Application Laid-Open No. 2008-258554 Summary of the Invention [Problem to be solved by the invention]

[0007] However, even if the tilt of the holding table is finely adjusted to achieve the desired finished thickness of the wafer, problems may occur in that the desired finished thickness is not achieved after actual processing, or the desired thickness accuracy is not realized. For example, there is a concern that defects such as thickness variation may occur or the cross-sectional shape of the ground surface may be curved rather than flat.

[0008] In view of the above problems, the present invention relates to a technology for fine-tuning the tilt of a holding table, and proposes a new technology that enables improving the machining accuracy of workpieces by measuring the height position of the holding surface of the holding table. [Means for solving the problem]

[0009] The problem to be solved by the present invention is as described above, and the means for solving this problem will now be described.

[0010] According to one aspect of the present invention, there is provided a processing apparatus comprising at least a holding table having a holding surface for holding a workpiece, an inclination adjustment unit disposed below the holding table and having a fixed support portion and at least two movable support portions, and adjusting the inclination of the holding table using the movable support portions, a measurement unit for measuring the height position of the upper surface of the holding table, and a control unit, wherein the control unit has a judgment portion for judging an abnormality based on measurement values ​​measured by the measurement unit, and the measurement unit has at least a first measurement portion and a second measurement portion for measuring the height position of the upper surface of the holding table at positions above the two movable support portions, and the judgment portion compares the measurement value of the first measurement portion with a first reference height and the measurement value of the second measurement portion with the second reference height to judge an abnormality.

[0011] According to one aspect of the present invention, the first reference height is preset in the control unit, and the second reference height is preset in the control unit.

[0012] Furthermore, according to one aspect of the present invention, the first reference height is the measurement height previously measured by the first measurement unit, and the second reference height is the measurement height previously measured by the second measurement unit.

[0013] According to another aspect of the present invention, when the determining section determines that an abnormality has occurred, the control unit operates the movable support section to adjust the tilt of the holding table.

[0014] Furthermore, according to one aspect of the present invention, there is provided a method for determining an abnormality in a processing apparatus that includes at least a holding table having a holding surface for holding a workpiece, a tilt adjustment unit arranged below the holding table, having a fixed support portion and at least two movable support portions, and adjusting the tilt of the holding table using the movable support portions, a measurement unit that measures the height position of the upper surface of the holding table, and a control unit, wherein the control unit has a determination section that determines an abnormality based on measurement values ​​measured by the measurement unit, and the measurement unit has at least a first measurement section and a second measurement section that measure the height position of the upper surface of the holding table at positions above the two movable support portions, and the determination section determines an abnormality by comparing the measurement value of the first measurement section with a first reference height and the measurement value of the second measurement section with the second reference height, respectively. [Effects of the Invention]

[0015] The present invention provides the following effects. That is, according to one aspect of the present invention, the height position of the surface of the holding table is directly measured, so it is possible to reliably determine whether the tilt of the surface of the holding table is abnormal.

[0016] Furthermore, according to one aspect of the present invention, if an abnormality is determined, the movable support part is operated to correct the inclination of the holding table, thereby correcting the inclination of the surface of the holding table so that it does not exceed a predetermined threshold, thereby achieving ideal processing. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a diagram showing a grinding apparatus as an example of a processing apparatus in which the present invention can be implemented; [Figure 2] FIG. 2 is a diagram illustrating the configuration of a rough grinding means. [Figure 3] 3A and 3B are diagrams illustrating the configuration of a measurement unit. [Figure 4] 3A and 3B are side views of a holding table and diagrams illustrating the positions of measurement points. [Figure 5] 3 is a flowchart showing steps constituting an abnormality determination method. [Figure 6] FIG. 2 is a diagram for explaining measurement points of a first measurement unit and a second measurement unit. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a diagram showing a grinding apparatus 1, which is an example of a processing apparatus in which the present invention can be implemented. Note that the present invention is applicable not only to a grinding apparatus that grinds and thins a workpiece held on a holding table, but also to a polishing apparatus that polishes a workpiece held on a holding table.

[0019] The grinding apparatus 1 shown in FIG. 1 is an apparatus that includes rough grinding means 30 and finish grinding means 31, and grinds a workpiece W held on a holding table 5 disposed below each of the means.

[0020] The grinding device 1 is configured, for example, by connecting a first device base 10 and a second device base 11 to the rear (+Y direction side) of the first device base 10. The first device base 10 serves as a loading / unloading area A where workpieces W are loaded and unloaded. The second device base 11 serves as a grinding area B where the workpieces W are ground by rough grinding means 30 and finish grinding means 31.

[0021] The workpiece W is, for example, a circular semiconductor wafer made of a silicon base material or the like. A plurality of devices are formed on the front surface Wa of the workpiece W, which faces downward in FIG. 1, and is protected by a protective tape T attached thereto. The back surface Wb of the workpiece W is the processing surface to be subjected to the grinding process. Note that the workpiece W may be made of gallium arsenide, sapphire, gallium nitride, ceramics, resin, silicon carbide, or the like, in addition to silicon, or may be a package substrate or the like.

[0022] A first cassette loading section 150 and a second cassette loading section 151 are provided on the front side (-Y direction side) of the first device base 10, and a first cassette 150a that contains the workpiece W before processing is loaded on the first cassette loading section 150, and a second cassette 151a that contains the workpiece W after processing is loaded on the second cassette loading section 151.

[0023] A robot 155 is disposed behind the opening of the first cassette 150a for carrying out unprocessed workpieces W from the first cassette 150a and carrying out processed workpieces W into the second cassette 151a. A temporary placement area 152 is provided adjacent to the robot 155, and an alignment means 153 is disposed in the temporary placement area 152. The alignment means 153 uses a diameter-reducing alignment pin to align (center) the workpieces W carried out from the first cassette 150a and placed in the temporary placement area 152 to a predetermined position.

[0024] A loading arm 154a that rotates while holding a workpiece W is disposed adjacent to the alignment means 153. The loading arm 154a holds the workpiece W that has been aligned by the alignment means 153, and transports it to one of the holding tables 5 disposed in the grinding processing area B. An unloading arm 154b that rotates while holding the processed workpiece W is disposed next to the loading arm 154a. A cleaning means 156 that cleans the processed workpiece W transported by the unloading arm 154b is disposed in close proximity to the unloading arm 154b. The workpiece W cleaned by the cleaning means 156 is carried into the second cassette 151a by a robot 155.

[0025] A first column 12 is erected at the rear (+Y direction side) of the second device base 11, and a rough grinding feed means 20 is arranged in front of the first column 12, and the rough grinding feed means 20 moves the rough grinding means 30 back and forth in the Z axis direction.

[0026] The rough grinding means 30 includes a grinding wheel 304 that is rotated by a spindle motor 302, and below the grinding wheel 304, a plurality of rough grinding stones containing relatively large abrasive grains are arranged in the circumferential direction.

[0027] Further, at the rear of the second device base 11, a second column 13 is erected alongside the first column 12 in the X-axis direction, and a finish grinding feed means 21 is disposed in front of the second column 13. The finish grinding feed means 21 causes the finish grinding means 31 to move back and forth in the Z-axis direction.

[0028] The finish grinding means 31 includes a grinding wheel 314 that is rotated by a spindle motor 312, and below the grinding wheel 314, a plurality of finish grinding stones containing relatively small abrasive grains are arranged in the circumferential direction.

[0029] A turntable 6 is disposed on the second device base 11, and three holding tables 5 are disposed on the upper surface of the turntable 6 at equal intervals in the circumferential direction. A rotation means 66 for rotating the turntable 6 is disposed below the turntable 6, and the rotation means 66 can rotate the turntable 6 about its axis in the Z-axis direction. The rotation of the turntable 6 causes the three holding tables 5 to revolve, and the holding tables 5 can be sequentially positioned from near the temporary placement area 152, below the rough grinding means 30, and below the finish grinding means 31.

[0030] The holding table 5 has, for example, a circular outer shape and includes an adsorption portion 510 made of a porous material or the like that adsorbs the workpiece W, and a frame 511 that supports the adsorption portion 510. The adsorption portion 510 is connected to a suction source (not shown), such as a vacuum generator, and the suction force generated by the suction source is transmitted to a holding surface 510a, which is the exposed surface of the adsorption portion 510, causing the holding table 5 to adsorb and hold the workpiece W on the holding surface 510a. The holding table 5 is fixed on a table base 55 that is, for example, circular in plan view, and is rotatable on a turntable 6 about an axis in the Z-axis direction.

[0031] A support base 60 is disposed adjacent to the holding table 5, which is positioned below the rough grinding means 30 or the finish grinding means 31. In this embodiment, the support base 60 is disposed in the center of the turntable 6, and is provided with measuring units 38A, 38B (commonly known as height gauges) for measuring the height position of the holding surface of the holding table 5. The measuring units 38A, 38B will be described in detail later.

[0032] The grinding apparatus 1 is equipped with a control unit 9 that is configured with a CPU, a storage unit 90 such as a memory, and the like. The control unit 9 is electrically connected to, for example, the rough grinding feed means 20, the finish grinding feed means 21, the rough grinding means 30, and the rotation means 66, and under the control of the control unit 9, the rough grinding feed operation of the rough grinding means 30 by the rough grinding feed means 20, the finish grinding feed operation of the finish grinding means 31 by the finish grinding feed means 21, the rotation operation of the rough grinding wheel 304b in the rough grinding means 30, and the rotation operation of the turntable 6 by the rotation means 66 are controlled.

[0033] As will be described in detail later, control unit 9 controls measurements by measuring units 38A and 38B. Control unit 9 also has a determination unit 91 for determining whether the values ​​measured by measuring units 38A and 38B are abnormal.

[0034] The grinding device 1 is equipped with a touch panel 70 for inputting processing conditions, displaying the processing state, etc. The input contents of the touch panel 70 are stored in a storage unit 90 and are referred to as appropriate. For example, a threshold value that serves as a criterion for abnormality determination, which will be described in detail later, is input from the touch panel 70.

[0035] 2 shows the configuration of the rough grinding means 30. The finish grinding means 31 has a similar configuration, so its description will be omitted. The spindle 300 of the rough grinding means 30 rotates around a spindle rotation axis 300a in the vertical direction (Z-axis direction), and a grinding wheel 304 is fixed to a wheel mount 303 provided at the bottom end of the spindle 300.

[0036] The holding table 5 includes an adsorption portion 510 made of a disc-shaped porous member or the like that adsorbs the workpiece W (wafer), and a frame 511 that supports the adsorption portion 510. A motor 512 that rotates the holding table 5 about a table rotation shaft 513 is provided below the holding table 5. The holding table 5, motor 512, and table rotation shaft 513 constitute a holding means 51. The adsorption portion 510 is connected to a suction source (not shown), and the suction force generated by the suction source is transmitted to a holding surface 510a, which is the exposed surface of the adsorption portion 510, thereby adsorbing and holding the workpiece W (wafer) on the holding surface 510a.

[0037] The holding table 5 is supported by a tilt adjustment means 56 that adjusts the tilt of a table rotation axis 513 that passes through the center of the holding surface 510a. The tilt adjustment means 56 has at least three support parts, at least two of which are movable support parts 52 and 53, and the remaining part is a fixed support part 54. In this embodiment, the tilt adjustment means 56 has two movable support parts 52 and 53 and one fixed support part 54, which are arranged at a regular interval in the circumferential direction on the bottom side of the frame body 511. Note that a configuration in which three movable support parts and no fixed support part are arranged may also be used, with all parts being movable support parts. Furthermore, a total of four or more movable support parts and fixed support parts may also be arranged.

[0038] 2, the first movable support part 52 is composed of a motor 520 disposed on a base 55 inside the grinding device 1, a rotatable adjustment shaft 521 connected to the motor 520, a support part 522 that rotatably supports the adjustment shaft 521, and a housing part 523 that protrudes downward from the bottom of the frame body 511 and houses the adjustment shaft 521. The motor 520 is connected to the control unit 9 and operates under the control of the control unit 9.

[0039] Male thread 521a is formed at the tip of adjustment shaft 521, and female thread 523a that screws onto male thread 521a is formed on the inner surface of housing portion 523. Furthermore, origin sensor 523b that detects the position of the tip of adjustment shaft 521 is disposed on the inner surface of housing portion 523. Control unit 9 recognizes the position of the tip of adjustment shaft 521 in a relative relationship with origin sensor 523b.

[0040] On the other hand, the fixed support portion 54 has a fixed shaft 541 whose lower end is fixed onto the base 55 and whose upper end is fixed to the lower part of the frame body 511 .

[0041] In the first movable support part 52, the motor 520 rotates the adjustment shaft 521 under the control of the control unit 9, whereby the male screw 521a advances and retreats relative to the female screw 523a, raising and lowering the accommodation part 523, and changing the relative height of the frame body 511 with respect to the base 55. The configuration of the second movable support part 53 is similar to that of the first movable support part 52. On the other hand, in the fixed support part 54, the height position of the frame body 511 with respect to the base 55 does not change. Therefore, the height of the adjustment shaft 521 with respect to the accommodation part 523 rises and falls relative to the accommodation part 523, or the height of the adjustment shaft 531 with respect to the accommodation part 533 rises and falls relative to the accommodation part 533, thereby changing the inclination of the table rotation axis 513 with respect to the spindle rotation axis 300a.

[0042] The holding surface 510a is a conical surface, and is adjusted by the tilt adjustment means 56 so that a partial radial area of ​​the conical surface is parallel to the lower surface (grinding surface) of the rough grinding wheel 304b.

[0043] 3 and 4 are diagrams for explaining the arrangement of the holding table and the measurement unit. 3 and 4, the three holding tables have a common configuration and will be described as first to third holding tables 5A to 5C for convenience. The holding tables 5A to 5C move so as to revolve around the rotation axis of the turntable 6, and are sequentially positioned at a Z1 position below the rough grinding means 30, a Z2 position below the finish grinding means 31, and a Z3 position for loading and unloading workpieces.

[0044] 3, two measurement units 38A and 38B are disposed in a position surrounded by three holding tables 5A to 5C. One measurement unit 38A measures the holding table positioned at position Z1, and the other measurement unit 38B measures the holding table positioned at position Z2, and they have the same configuration as measurement unit 38A and are line-symmetrical.

[0045] As shown in Fig. 3, the measurement unit 38A has a first measurement unit S1 to a third measurement unit S3. The first measurement unit S1 is configured with an arm and a measurement probe attached to the tip of the arm, and is configured so that the height position at the contact point can be detected by bringing the lower end of the measurement probe into contact with the upper surface of the holding table 5A. The other measurement units, the second measurement unit S2 and the third measurement unit S3, have a similar configuration. Note that the number of measurement units provided in the measurement unit 38A may be three, namely the first measurement unit S1 to the third measurement unit S3, but more measurement units may be provided.

[0046] The base end of the arm of the first measurement unit S1 is connected to an elevation mechanism 38c, which moves the measurement probe at the tip of the arm up and down. The elevation mechanism 38c raises the measurement probe to a retracted position during grinding, and lowers the measurement probe to a measurement position during measurement. The other measurement units, the second measurement unit S2 and the third measurement unit S3, are configured in a similar manner.

[0047] 4, for the holding table 5A placed at the Z1 position, the first measurement unit S1 is positioned so as to measure the height position of the upper surface of the holding table 5A at a measurement point M1 which is a position above the first movable support unit 52. In this embodiment, the position of the measurement point M1 is on the upper surface 511a of the frame 511 which supports the suction unit 510 of the holding table 5A, and is also a position above the first movable support unit 52, as shown in FIG.

[0048] 4, for the holding table 5A placed at the Z1 position, the second measurement unit S2 is positioned so as to measure the height position of the upper surface of the holding table 5A at a measurement point M2 which is a position above the second movable support unit 53. In this embodiment, the position of the measurement point M2 is on the upper surface 511a of the frame 511 which supports the suction unit 510 of the holding table 5A, and is also a position above the second movable support unit 53, as shown in FIG.

[0049] 4, the third measuring unit S3 is disposed so as to measure the height position of a workpiece (not shown) held on the holding table 5A at a measurement point M3. The position of the measurement point M3 is disposed, for example, on an arc passing through the movable support units 52 and 53.

[0050] In the above configuration, the control unit 9 (FIG. 1) measures the measurement heights H1 and H2 at the measurement points M1 and M2 for the holding table 5A placed at the Z1 position. This measurement is performed, for example, before the holding table 5A is moved to the Z2 position after being placed at the Z1 position and grinding is performed, or after the holding table 5A is moved from the Z3 position to the Z1 position and grinding is performed.

[0051] A first reference height K1 at measurement point M1 and a second reference height K2 at measurement point M2 are pre-stored in a memory unit 90 (FIG. 1) of the control unit. The memory unit 90 (FIG. 1) also pre-stores a threshold value (e.g., 10 μm) for comparison with a relative value, which will be described later.

[0052] Then, the judgment unit 91 (Figure 1) of the control unit calculates the relative values ​​(differences) between each reference height K1, K2 and each measurement height H1, H2, which is the measurement value (actual measurement value), and compares the calculated relative values ​​with a threshold value to make an abnormality judgment.

[0053] As one method of determining an abnormality, for example, if the calculated relative value (difference) for measurement point M1 is 15 μm and the threshold value is 10 μm, it is determined that the height position of measurement point M1 on the holding table is significantly different from reference height K1, and an abnormality is determined. The same applies to measurement point M2.

[0054] As another method of determining an abnormality, for example, for measurement point M1, the relative value (difference) between the measurement height H1 (first reference height: previously measured measurement height) at the timing before the above-mentioned movement and the measurement height H1 (currently measured measurement height) at the timing after the above-mentioned movement is calculated. In other words, the change in the height position of measurement point M1 before and after the revolution of holding table 5A due to the rotation of turntable 6 (FIG. 1) is calculated. For example, if the calculated relative value is 15 μm and the threshold is 10 μm, it is determined that the height position of measurement point M1 of the holding table has changed significantly before and after the movement due to the rotation of turntable 6 (FIG. 1), and an abnormality is determined. The same applies to measurement point M2.

[0055] It should be noted that either one of the two methods of abnormality determination described above may be implemented, or both may be implemented.

[0056] Furthermore, the control unit 9 (FIG. 1) measures the measurement heights H1 and H3 of the measurement points M1 and M3 for the holding table 5A placed at the Z1 position, and calculates the relative value (difference) between the measurement heights H1 and H3, thereby calculating the thickness of the workpiece (not shown). Note that the thickness of the workpiece (not shown) may also be calculated from the measurement heights H2 and H3 of the measurement points M2 and M3.

[0057] The above description is about the first holding table 5A placed at the Z1 position, but similar measurements are also performed on the other holding tables 5B and 5C when they are placed at the Z1 position.

[0058] 3, the first to third holding tables 5A to 5C, which are sequentially arranged at the Z2 position, are also measured by measuring unit 38B to determine abnormalities and measure the thickness of the workpiece. Specifically, like measuring unit 38A, measuring unit 38B has fourth to sixth measuring units S4 to S6. As shown in FIG. 4, fourth measuring unit S4 measures the height position of the upper surface of holding table 5A at measurement point M4, which is above second movable support member 53. Fifth measuring unit S5 measures the height position of the upper surface of holding table 5A at measurement point M5, which is above first movable support member 52. Sixth measuring unit S6 measures the height position of the upper surface of a workpiece (not shown) held on the holding surface of the holding table.

[0059] In this way, a processing apparatus is configured that includes at least a holding table having a holding surface for holding the workpiece, a tilt adjustment unit arranged below the holding table and having a fixed support part and at least two movable support parts, which adjusts the tilt of the holding table using the movable support parts, a measurement unit that measures the height position of the upper surface of the holding table, and a control unit.

[0060] Next, an embodiment of a method for determining an abnormality in a processing device using the above configuration will be described below. Fig. 5 is a flowchart showing steps constituting the method for determining an abnormality.

[0061] The abnormality determination method described below can be performed, for example, during periodic maintenance, or can be performed when a predetermined number of workpieces have been machined. In the following embodiment, an example will be described in which the holding table 5 positioned below the rough grinding means 30 is measured using the measuring unit 38A, but the same applies when the holding table 5 positioned below the finish grinding means 31 is measured using the measuring unit 38B (FIG. 1), and so a description thereof will be omitted.

[0062] <Preparation steps> This is the step of setting the numerical value to be referred to when determining an abnormality.

[0063] This preparation step is performed, for example, by an operator operating the touch panel 70 (FIG. 1) as a pre-setup operation before operating the grinding device. By allowing the threshold value to be set by the operator in this way, for example, the operator can set the threshold value to a small value at his / her discretion, thereby enabling more strict management of thickness accuracy.

[0064] For example, when abnormality determination is performed by calculating the relative value (difference) between the reference height and the measured height at each measurement point, the reference heights (first reference height, second reference height) and a threshold value (e.g., 10 μm) are set. Also, when abnormality determination is performed by calculating the relative value of the measured height before and after movement, the threshold value (e.g., 10 μm) is set.

[0065] <Measurement steps> 6, for holding table 5A at position Z1, this is a step in which first measurement section S1 and second measurement section S2 of measurement unit 38A measure the height position of upper surface 5a of holding table 5 at measurement points M1 and M2, which are positions above movable support sections 52 and 53. Note that holding table 5B at position Z2 can also be measured in the same way by measurement unit 38B.

[0066] Specifically, based on the operator's operation of the touch panel 70 (FIG. 1), the control unit 9 (FIG. 1) positions the first measurement unit S1 and the second measurement unit S2 (measurement needles S1b, S2b) at measurement points M1, M2, which are positions above the movable support members 52, 53, and measures the height positions H1, H2 of each measurement point M1, M2. Note that in this specification, the "upper position" can be, for example, within a circle with a radius of 5 mm to 20 mm in a plan view.

[0067] <Abnormality determination step> As shown in FIG. 6, this is a step for determining whether an abnormality has occurred based on the measurement values ​​obtained in the measurement step.

[0068] Specifically, as shown in FIG. 6, the judgment unit 91 (FIG. 1) of the control unit calculates relative values ​​D1 and D2 (differences) between the measurement heights H1 and H2 measured at measurement points M1 and M2 for the holding table 5A at the Z1 position and the reference heights K1 and K2 set in the preparation step, respectively. If the calculated relative values ​​D1 and D2 exceed threshold values ​​P1 and P2, respectively, it judges the tilt of the holding table to be abnormal. For example, if the threshold value is 10 μm and the relative value is 5 μm, the deviation from the reference height is small and the tilt of the holding table is judged to be normal. On the other hand, if the relative value is 15 μm, the deviation from the reference height is large and the tilt of the holding table is judged to be abnormal. The same applies to the holding table 5B at the Z2 position.

[0069] Alternatively, as another method of determining an abnormality, the determination unit 91 (FIG. 1) of the control unit calculates the relative value (difference) of the measured height of the holding table 5A at the Z1 position before and after the movement of the holding table due to the revolution of the turntable 6 (FIG. 1), and determines that an abnormality has occurred if the calculated relative value exceeds a threshold value. For example, if the threshold value is 10 μm and the relative value is 5 μm, the change in height before and after the movement of the holding table is small, and the tilt of the holding table is determined to be normal. On the other hand, if the relative value is 15 μm, the change in height before and after the movement of the holding table is large, and the tilt of the holding table is determined to be abnormal. The same applies to the holding table 5B at the Z2 position.

[0070] If an abnormality is determined, the abnormality is notified by, for example, displaying a warning on the touch panel 70 (FIG. 1) or emitting a warning sound from a speaker (not shown).

[0071] <Adjustment steps> If an abnormality is determined in the abnormality determination step, this is a step in which the movable support members 52 and 53 are operated to adjust the tilt of the holding table 5A at the Z1 position shown in Fig. 6 so that the relative values ​​D1 and D2 do not exceed the thresholds. The same is true for the holding table 5B at the Z2 position.

[0072] Specifically, as shown in FIG. 3, the control unit 9 monitors the relative values ​​based on the measured values ​​at the first measurement unit S1 and the second measurement unit S2, and adjusts the inclination of the table rotation axis 513 relative to the spindle rotation axis 300a by rotating the adjustment axes 521 and 531 so that the relative values ​​do not exceed the threshold values, as shown in FIG. 2.

[0073] In this way, it is possible to adjust and manage the tilt of the holding table, and ideal grinding can be performed to achieve high thickness accuracy. The adjustment step may be executed by an operator operating the touch panel 70, or may be started automatically when an abnormality is detected. For example, the adjustment step may be performed so that the relative value does not exceed a threshold value during the adjustment step, or may be adjusted to achieve a relative value (e.g., 10 μm) arbitrarily specified by the operator.

[0074] The present invention is not limited to the above-described embodiment, and may be embodied in various different forms within the scope of the technical concept thereof. Furthermore, the embodiments shown in the accompanying drawings are not limited to these, and may be modified as appropriate within the scope of the effects of the present invention. [Explanation of symbols]

[0075] 1 Grinding equipment 5 Holding table 5A Holding table 5B Holding table 5C Holding table 6. Turntable 9. Control Unit 30 Rough grinding means 31 Grinding means 38A Measuring Unit 38B Measuring Unit 38c Lifting mechanism 51 Holding means 52 Movable support part 53 Movable support part 54 Fixed support part 56 Tilt adjustment means 70 Touch Panel 90 Memory section 91 Judgment section 300 spindles 300a spindle rotation axis 304 Grinding Wheel 312 Spindle motor 314 Grinding Wheel 510 Adsorption part 510a retaining surface 511 Frame 511a top side 520 Motor 521 Adjustment axis 531 Adjustment axis 541 Fixed axis M1 measurement point M2 measurement point M3 measurement point S1 1st measurement section S2 2nd measurement section S3 3rd measurement section W Workpiece

Claims

1. a holding table having a holding surface for holding a workpiece; a tilt adjustment unit disposed below the holding table, the tilt adjustment unit having a fixed support portion and at least two movable support portions, and configured to adjust the tilt of the holding table by the movable support portions; a measurement unit for measuring the height position of the upper surface of the holding table; a control unit; A processing device comprising at least The control unit has a determination unit that determines whether an abnormality has occurred based on a measurement value measured by the measurement unit, The measurement unit comprises: a first measuring unit and a second measuring unit that measure the height position of the upper surface of the holding table at positions above the two movable support units, The determination unit a measurement value in the first measurement unit and a first reference height; the measurement value of the second measuring unit is compared with a second reference height to determine whether an abnormality has occurred; Processing equipment.

2. the first reference height is preset in the control unit; The second reference height is preset in the control unit.

2. The processing device according to claim 1.

3. the first reference height is a measurement height previously measured by the first measurement unit, The second reference height is a measurement height previously measured by the second measurement unit.

2. The processing device according to claim 1.

4. When the determination unit determines that an abnormality has occurred, the control unit: The movable support unit is operated to adjust the tilt of the holding table.

4. The processing device according to claim 1, wherein the processing device is a processing device for processing a substrate.

5. a holding table having a holding surface for holding a workpiece; a tilt adjustment unit disposed below the holding table, the tilt adjustment unit having a fixed support portion and at least two movable support portions, and configured to adjust the tilt of the holding table by the movable support portions; a measurement unit for measuring the height position of the upper surface of the holding table; a control unit; An abnormality determination method for a processing device comprising at least The control unit has a determination unit that determines whether an abnormality has occurred based on a measurement value measured by the measurement unit, The measurement unit comprises: a first measuring unit and a second measuring unit that measure the height position of the upper surface of the holding table at positions above the two movable support units, The determination unit a measurement value in the first measurement unit and a first reference height; the measurement value of the second measuring unit is compared with a second reference height to determine whether an abnormality has occurred; A method for determining abnormalities in a processing device.

6. the first reference height is preset in the control unit; The second reference height is preset in the control unit.

6. The method for determining an abnormality in a processing device according to claim 5.

7. the first reference height is a measurement height previously measured by the first measurement unit, The second reference height is a measurement height previously measured by the second measurement unit.

6. The method for determining an abnormality in a processing device according to claim 5.

8. When the determination unit determines that an abnormality has occurred, the control unit: The movable support unit is operated to adjust the tilt of the holding table.

8. The method for determining an abnormality in a processing device according to claim 5.

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