Processing System

Abstract

To provide a processing system which can efficiently process a plurality of work-pieces with good accuracy.SOLUTION: A processing system 1, which performs pre-grinding and fine grinding in order for work-pieces W1, W2, comprises a chuck 3 for rotatably holding the work-pieces W1, W2. Further, the processing system comprises: an index table 2 which moves the work-pieces W1, W2 to a rough grinding stage ST2, a middle grinding stage ST3, a fine grinding stage ST4 and an alignment stage S1 in this order; a tilt mechanism 33 which can adjust inclination of the chuck 3; an oscillation type sensor 72 which measures shapes of the work-pieces W1, W2 before fine grinding; a fixation type sensor 8 which measures the shape of the work-piece W1 after fine grinding during transportation of the work-piece W1 after fine grinding to the alignment stage ST4; and a control unit 9 which controls an inclination angle which is inclination of the chuck 3 when performing fine grinding on the basis of the shapes of the work-pieces W1, W2 before fine grinding, and corrects the inclination angle when performing fine grinding of the work-piece W2 on the basis of the shape of the work-piece W1 after fine grinding.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a processing system for continuously grinding a plurality of workpieces. [Background technology]

[0002] In the field of semiconductor manufacturing, a grinding device is known that grinds semiconductor wafers such as silicon wafers (hereinafter referred to as "workpieces") into a thin, flat shape by pressing the grinding surface of a rotating grinding wheel against the workpiece.

[0003] Patent Document 1 discloses a grinding machine that processes a workpiece in the order of rough grinding, fine grinding, and polishing. This machine uses a swing-type thickness sensor in the polishing stage to measure the shape of the workpiece after polishing, and if the shape of the workpiece after polishing is not the desired shape, it adjusts the tilt amount of the tilt mechanism when fine grinding the next workpiece to be processed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-79457 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the grinding processing device described in Patent Document 1, when measuring the shape of the workpiece after processing, the polishing pad needs to be retracted and then the thickness sensor needs to scan the workpiece after polishing, which poses a problem of reduced throughput when processing multiple workpieces consecutively.

[0006] Therefore, a technical problem arises that must be solved in order to machine a plurality of workpieces accurately and efficiently, and an object of the present invention is to solve this problem. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the processing system of the present invention is a processing system that performs pre-grinding and fine grinding on a workpiece in sequence, and is equipped with a chuck that rotatably holds the workpiece, an index table that moves the workpiece at least through the pre-grinding stage, the fine grinding stage, and the alignment stage in that order, a tilt mechanism that can adjust the inclination of the chuck, a first sensor that measures the shape of the workpiece before fine grinding, a second sensor that measures the shape of the workpiece after fine grinding while the workpiece after fine grinding is being transported to the alignment stage, and a control device that controls the tilt angle, which is the tilt of the workpiece during fine grinding, based on the shape of the workpiece before fine grinding, and corrects the tilt angle when fine grinding a next workpiece, based on the shape of the workpiece after fine grinding. [Effects of the Invention]

[0008] The present invention can accurately and efficiently machine multiple workpieces. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a plan view showing a processing system according to an embodiment of the present invention; [Figure 2] FIG. 4 is a plan view showing the positional relationship between the chuck, the swing type thickness sensor, and the tilt mechanism. [Figure 3] FIG. 10 is a schematic diagram showing the installation position of a fixed thickness sensor. [Figure 4] FIG. 2 is a schematic diagram showing the positional relationship of measurement points of a fixed thickness sensor on a workpiece. [Figure 5] Schematic diagram showing the procedure for machining the first workpiece. [Figure 6] Graph showing the shape of the outer periphery of the first workpiece before and after fine grinding. [Figure 7] 10 is a table showing the amount of lift of each movable support part during precision grinding of each workpiece. [Figure 8] Schematic diagram showing the procedure for machining the second workpiece. [Figure 9]Graph showing the shape of the outer periphery of the second workpiece before and after fine grinding. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of the present invention will be described with reference to the drawings. Note that, hereinafter, when referring to the number, numerical value, amount, range, etc. of components, unless otherwise specified or when it is clearly limited to a specific number in principle, it is not limited to the specific number, and may be more or less than the specific number.

[0011] Furthermore, when referring to the shape or positional relationship of components, etc., it includes things that are substantially similar or approximate to those shapes, etc., unless otherwise specified or when it is clearly considered otherwise in principle.

[0012] In addition, the drawings may exaggerate characteristic parts to make the features easier to understand, and the dimensional proportions of the components may not be the same as in reality. In addition, in cross-sectional views, hatching of some components may be omitted to make the cross-sectional structure of the components easier to understand.

[0013] 1 is a plan view showing the basic configuration of a processing system 1. The processing system 1 performs a plurality of grinding processes consecutively on a workpiece W. Note that the processing system 1 may perform only either grinding or polishing, or may perform polishing after grinding.

[0014] The processing system 1 is provided with four stages: an alignment stage ST1, a rough grinding stage ST2, a medium grinding stage ST3, and a fine grinding stage ST4. Note that the number of stages (pre-grinding stages) that sequentially process the workpiece W upstream of the fine grinding stage ST4 is not limited to two, the rough grinding stage ST2 and the medium grinding stage ST3, and may be one or three or more.

[0015] The processing system 1 includes an index table 2 that can rotate around a rotation axis 2a, and four chucks 3 that are arranged at equal intervals on a concentric circle centered on the rotation axis 2a of the index table 2. As the index table 2 rotates, the chucks 3 can move in the following order: alignment stage ST1, rough grinding stage ST2, medium grinding stage ST3, and fine grinding stage ST4.

[0016] The chuck 3 has an adsorption body 32 made of a porous material such as alumina embedded in the upper surface of a rotary table 31. The surface (adsorption surface) of each adsorption body 32 of the four chucks 3 is uniformly formed by self-grinding before machining. The chuck 3 has a pipe line (not shown) that runs through the interior and extends to the surface. The pipe line is connected to a vacuum source, a compressed air source, or a water supply source via a rotary joint (not shown). When the vacuum source is activated, the workpiece W placed on the chuck 3 is adsorbed and held by the chuck 3. When the compressed air source or water supply source is activated, the adsorption between the workpiece W and the chuck 3 is released.

[0017] The rotary table 31 is connected to a chuck spindle (not shown). The chuck spindle is configured to be rotatable around a rotation axis perpendicular to the rotary table 31.

[0018] 2, the chuck 3 is supported by a tilt mechanism 33 that can tilt a rotation axis 3a (a vertical axis passing through the center O of the workpiece W) of the chuck 3. The tilt mechanism 33 includes a tilt table 34, a fixed support part 35, a first movable support part 36, and a second movable support part 37.

[0019] The tilt table 34 is formed in a substantially triangular shape in a plan view and is interposed between the index table 2 and the chuck 3, and supports the rotary table 31.

[0020] The fixed support part 35, the first movable support part 36, and the second movable support part 37 are arranged on the tilt table 34 at equal intervals on a concentric circle centered on the rotation axis 3a of the chuck 3. The fixed support part 35 is a bolt that connects the index table 2 and the tilt table 34.

[0021] The first movable support part 36 is arranged upstream of the fixed support part 35 in the rotation direction D of the chuck 3. The second movable support part 37 is arranged downstream of the fixed support part 35 in the rotation direction D of the chuck 3. The first movable support part 36 and the second movable support part 37 are each configured to be able to raise and lower the tilt table 34 independently with respect to the index table 2 by using a motor to rotate a ball screw arranged vertically between the index table 2 and the tilt table 34.

[0022] Returning to Fig. 1, in the alignment stage ST1, the first arm 41 takes out the workpiece W from the first rack 42 in which the unmachined workpiece W is stored, and transports it to the chuck 3 located within the alignment stage ST1. The workpiece W is positioned in advance so that its orientation is aligned with a predetermined direction. In addition, the second arm 43 receives the machined workpiece W from the chuck 3 located within the alignment stage ST1, and transports it to the second rack 44 in which the machined workpiece W is stored.

[0023] The rough grinding stage ST2 is provided with a rough grinding device 5. The rough grinding device 5 includes a rough grinding wheel 51 (described later), a first spindle 52 to which the rough grinding wheel 51 is attached at its lower end and which rotatably supports the rough grinding wheel 51, and a first spindle feed mechanism 53 which moves the first spindle 52 up and down in the vertical direction. For example, an #8000 cup-type grinding wheel is used as the rough grinding wheel 51. The rough grinding device 5 is also provided with a thickness sensor (not shown) which measures the thickness of the workpiece W during rough grinding.

[0024] The medium grinding stage ST3 is provided with a medium grinding device 6. The medium grinding device 6 is equipped with a medium grinding wheel (not shown), a second spindle 61 to the lower end of which the medium grinding wheel is attached and which rotatably supports the medium grinding wheel, and a second spindle feed mechanism 62 which vertically raises and lowers the second spindle 61. For example, an #8000 cup-type grinding wheel is used as the medium grinding wheel. The medium grinding device 6 is also equipped with a thickness sensor (not shown) which measures the thickness of the workpiece W during medium grinding.

[0025] The precision grinding stage ST4 is provided with a precision grinding device 7. The precision grinding device 7 includes a precision grinding wheel 71, a third spindle (not shown) to which the precision grinding wheel 71 is attached at its lower end and which supports the precision grinding wheel 71 rotatably about a rotation axis set along the vertical direction, and a third spindle feed mechanism (not shown) which raises and lowers the third spindle in the vertical direction. The precision grinding wheel 71 is, for example, an #8000 cup-type grinding wheel. The precision grinding device 7 is also provided with a thickness sensor (not shown) which measures the thickness of the workpiece W during precision grinding.

[0026] The fine grinding stage ST4 is provided with an oscillating thickness sensor 72. The oscillating sensor 72 measures the thickness (film thickness) of the workpiece W before fine grinding and measures its shape. The oscillating sensor 72 is an optical sensor that can detect film thickness without contact, and as shown in FIG. 2, a sensor head 74 is attached to the tip of an arm 73, the base end of which is connected to a drive shaft 75 outside the index table 2. The arm 73 can oscillate along a horizontal plane with the drive shaft 75 as a fulcrum, and the sensor head 74 is configured to be movable from the outer peripheral position P1 of the workpiece W to a position where it overlaps with the center O of the workpiece W.

[0027] Returning to FIG. 1, the processing system 1 is provided with a fixed thickness sensor 8. The fixed sensor 8 non-contactly measures the thickness (film thickness) of the workpiece W after precision grinding and measures its shape. The fixed sensor 8 is, for example, a spectral interference film thickness measuring device. One fixed sensor 8 is provided upstream and one downstream of the alignment stage ST1 in the rotation direction of the index table 2. This is because, when the processed workpiece W is transported from the precision grinding stage ST4 to the alignment stage ST1, the index table 2 may rotate clockwise or counterclockwise on the page of FIG. 1 due to the rotation mechanism of the index table 2. To accommodate each rotation direction of the index table 2, one fixed sensor 8 is provided upstream and one downstream of the alignment stage ST1.

[0028] As shown in Fig. 3, the fixed sensor 8 is fixed to a frame 1a installed within the processing system 1, and is installed above the index table 2. The measurement point at which the fixed sensor 8 measures the thickness of the workpiece W is set on the rotational orbit R of the center O of the workpiece W when viewed from above. Note that Fig. 3 only illustrates the fixed sensor 8 provided between the alignment stage ST1 and the fine grinding stage ST4, and omits the fixed sensor 8 provided between the alignment stage ST1 and the rough grinding stage ST2.

[0029] FIG. 4 is a schematic diagram showing the positional relationship of the measurement points of the fixed sensor 8 on the workpiece W. Note that FIG. 4 illustrates the positional relationship of the measurement points of the fixed sensor 8 when the rotation speed of the index table 2 is set to 20 deg / sec, the rotation speed of the chuck 3 is set to 400 rpm, and the sampling period of the fixed sensor 8 is set to 4 milliseconds. Because the workpiece W passes directly below the fixed sensor 8 while rotating, the trajectory of the measurement points of the fixed sensor 8 extends over the entire surface of the workpiece W, including the center O of the workpiece W. Note that the trajectory of the measurement points of the fixed sensor 8 can be changed as appropriate depending on the rotation speed of the index table 2, the rotation speed of the chuck 3, and the sampling period of the fixed sensor 8.

[0030] In addition, the fixed sensor 8 is not limited to being placed upstream and downstream of the alignment stage ST1, as long as it is capable of measuring the thickness of the workpiece W after processing while it is being transported from the precision grinding stage ST4 to the alignment stage ST1, and may be placed, for example, upstream and downstream of the precision grinding stage ST4.

[0031] The operation of the machining system 1 is controlled by a control device 9. The control device 9 controls each of the components that make up the machining system 1. The control device 9 is composed of, for example, a CPU, a memory, etc. The functions of the control device 9 may be realized by control using software, or may be realized by operation using hardware.

[0032] The control device 9 drives the tilt mechanism 33 to tilt the rotation axis 3a of the chuck 3 relative to the rotation axis of the precision grinding wheel 71 based on the thickness of the workpiece W before precision grinding measured by the oscillating sensor 72 so that the workpiece W after precision grinding will approximately match the desired shape. Hereinafter, the angle of the rotation axis 3a of the chuck 3 relative to the rotation axis of the precision grinding wheel 71 will be referred to as the "tilt angle."

[0033] Next, a procedure for sequentially machining two workpieces W to be approximately flat will be described. Hereinafter, when distinguishing between the two workpieces W, they will be designated by the symbols W1 and W2. Note that the target shape of the workpieces W is not limited to being approximately flat.

[0034] <First work> At the alignment stage ST1, the first arm 41 takes out the workpiece W1 from the first rack 42 and transfers it to the chuck 3. Then, when the vacuum source is activated, negative pressure is supplied between the workpiece W1 and the chuck 3, and the workpiece W1 is adsorbed and held by the chuck 3.

[0035] Next, the index table 2 rotates, and the chuck 3 moves toward the rough grinding stage ST2.

[0036] The chuck 3 moves to the rough grinding stage ST2, and rough grinding is performed on the workpiece W1. In the rough grinding, as shown in Fig. 5(a), the grinding surface of the rough grinding wheel 51 is pressed against the workpiece W1 while the rough grinding wheel 51 and the chuck 3 are both rotating, and rough grinding of the workpiece W1 is performed. When the workpiece W1 reaches a desired thickness, as shown in Fig. 5(b), the rough grinding device 5 stops the rotation of the rough grinding wheel 51 and the chuck 3, and retracts the rough grinding wheel 51 upward, thereby completing rough grinding.

[0037] Next, the index table 2 rotates, and the chuck 3 moves toward the medium grinding stage ST3. At the medium grinding stage ST3, medium grinding is performed on the workpiece W1. In the medium grinding, the grinding surface of the medium grinding wheel is pressed against the workpiece W1 while the medium grinding wheel and the chuck 3 are rotating, and medium grinding of the workpiece W1 is performed. When the workpiece W reaches a desired thickness, the medium grinding device 6 stops the rotation of the medium grinding wheel and the chuck 3, and retracts the medium grinding wheel upward, thereby completing the medium grinding.

[0038] Next, the index table 2 rotates, and the chuck 3 moves toward the fine grinding stage ST4. Then, the arm 73 swings around the drive shaft 75 as a fulcrum, and the sensor head 74 scans from the outer peripheral position P1 of the workpiece W to a position overlapping with the center O of the workpiece W1, as shown in FIG. 5(c). This measures the shape of the workpiece W1 before fine grinding. FIG. 6 shows the shape of the first workpiece W before fine grinding.

[0039] Next, as shown in FIG. 5(d), the rotation axis 3a of the chuck 3 is tilted in accordance with the shape of the workpiece W1 before precision grinding.

[0040] Specifically, the control device 9 retrieves the grinding amount of the workpiece W1 during precision grinding that matches the difference between the shape of the workpiece W1 before precision grinding measured by the oscillating sensor 72 and the target shape of the workpiece W1 after grinding, and the tilt angle that realizes that grinding amount. Furthermore, the control device 9 retrieves the lift amounts of the first movable support member 36 and the second movable support member 37 that correspond to the tilt angle, and raises and lowers the first movable support member 36 and the second movable support member 37, respectively. As a result, the tilt table 34 tilts the rotation axis 3a of the chuck 3 with respect to the rotation axis of the precision grinding wheel 71, using the fixed support member 35 as a reference.

[0041] The control device 9 stores in advance the relationship between the grinding amount and the tilt angle of the workpiece W1 during precision grinding, which has been obtained through experiments or the like, and the respective lift amounts of the first movable support member 36 and the second movable support member 37 that achieve that tilt angle. FIG. 7(a) shows the respective lift amounts of the first movable support member 36 and the second movable support member 37 for the first workpiece W1 before precision grinding. Note that with respect to the lift amounts, positive (+) corresponds to the amount of lift, and negative (-) corresponds to the amount of lowering. That is, FIG. 7(a) illustrates the case where the first movable support member 36 is raised or lowered by 3 μm, and the second movable support member 37 is lowered by 1.5 μm.

[0042] 5(e), precision grinding is performed on the workpiece W1. Specifically, in the precision grinding, the grinding surface of the precision grinding wheel 71 is pressed against the workpiece W1 while the precision grinding wheel 71 and the chuck 3 are both rotating, and precision grinding of the workpiece W1 is performed. When the workpiece W reaches a desired thickness, the precision grinding device 7 stops the rotation of the precision grinding wheel 71 and the chuck 3, retracts the precision grinding wheel 71 upward, and ends the precision grinding.

[0043] Next, the index table 2 rotates, the chuck 3 moves toward the alignment stage ST1, and after the suction between the workpiece W1 and the chuck 3 is released, the second arm 43 removes the workpiece W1 from the chuck 3 and transfers it to the second rack 44.

[0044] While the index table 2 rotates and the chuck 3 moves toward the alignment stage ST1, the fixed sensor 8 measures the film thickness of the workpiece W1 at multiple measurement points across the entire surface of the workpiece W1, as shown in FIG. 5(f), to measure the shape of the workpiece W1. The number of measurement points of the fixed sensor 8 on the workpiece W1 is set to, for example, 200. The measurement points of the fixed sensor 8 are set on the rotational orbit R of the center O of the chuck 3 when viewed from above. This allows the fixed sensor 8 to measure the film thickness and shape of the workpiece W1 without reducing the throughput of the grinding process while the workpiece W1 is rotating around the rotation axis 3a and returning to the alignment stage ST1. FIG. 6 shows the shape of the first workpiece W after fine grinding.

[0045] Next, the control device 9 compares the shape of the workpiece W1 after precision grinding measured by the fixed sensor 8 with the desired target shape. If the shape of the workpiece W1 after precision grinding does not match the desired target shape, a correction angle to be added to the tilt angle during precision grinding is stored so that the shape matches the difference between the shape of the workpiece W1 after precision grinding and the desired target shape. The control device 9 previously stores the relationship, obtained through experiments or the like, between the difference between the shape of the workpiece W1 after precision grinding and the desired target shape and the correction angle that alleviates this difference, as well as the lift amounts (correction lift amounts) of the first movable support unit 36 ​​and the second movable support unit 37 that realize the correction angle of the tilt mechanism 33.

[0046] 6, it can be seen that the shape of the workpiece W1 after precision grinding is locally thinner by approximately 2 μm at its outer periphery (the area surrounded by the dashed ellipse in the graph) compared to the substantially flat target shape. Therefore, the control device 9 calls up a correction angle that will thicken the outer periphery of the workpiece W1 by approximately 2 μm, and also calls up correction elevation amounts that lower the first movable support member 36 by 0.3 μm and the second movable support member 37 by 0.2 μm, corresponding to this correction angle, as shown in FIG. 7(b). Note that if the shape of the workpiece W1 after precision grinding matches the desired target shape, both the correction angle and the correction elevation amount will be zero.

[0047] <Second work> Next, the second workpiece W2 is subjected to rough grinding and medium grinding in the same manner as the first workpiece W1, after which the index table 2 rotates and the chuck 3 moves toward the fine grinding stage ST4.

[0048] In the fine grinding stage ST4, first, the arm 73 swings on a horizontal plane around the drive shaft 75 as a fulcrum, and as shown in FIG. 8(a), the sensor head 74 scans from the outer peripheral position P1 of the workpiece W2 to a position overlapping with the center O of the workpiece W. This measures the shape of the workpiece W2 before fine grinding. FIG. 9 shows the shape of the second workpiece W before fine grinding. Note that, because the suction surfaces of each chuck 3 are uniformly formed by self-grinding before machining, it is assumed that the second workpiece W2 illustrated in FIG. 9 has approximately the same shape as the first workpiece W1.

[0049] Next, as shown in FIG. 8(b), the chuck 3 is tilted based on the tilt angle according to the shape of the workpiece W2 before precision grinding and the correction angle calculated from the machining result of the first workpiece W1.

[0050] Specifically, the control device 9 retrieves the grinding amount of the workpiece W2 during precision grinding that matches the difference between the shape of the workpiece W2 before precision grinding measured by the oscillating sensor 72 and the target shape of the workpiece W2 after grinding, and the tilt angle of the tilt mechanism 33 that realizes that grinding amount.The control device 9 then calculates the lift amounts of the first movable support member 36 and the second movable support member 37 according to the retrieved tilt angle.

[0051] The control device 9 also retrieves the corrected lift amounts of the first movable support unit 36 ​​and the second movable support unit 37 corresponding to the correction angles obtained by machining the first workpiece W1. The control device 9 then calculates the corrected lift amounts for each of the first movable support unit 36 ​​and the second movable support unit 37 by adding the corrected lift amounts to the lift amounts. The control device 9 then raises and lowers the first movable support unit 36 ​​and the second movable support unit 37 according to the corrected lift amounts. As a result, the tilt table 34 tilts the rotation axis 3a of the chuck 3 relative to the rotation axis of the fine grinding wheel 71, using the fixed support unit 35 as a reference. Figure 7(c) shows the corrected lift amounts of the first movable support unit 36 ​​and the second movable support unit 37 for the second workpiece W2 before fine grinding. Specifically, the corrected lifting amount in FIG. 7(c) is the lifting amount in FIG. 7(a) plus the corrected lifting amount in FIG. 7(b), which means that the first movable support member 36 is lifted or lowered by 2.7 μm and the second movable support member 37 is lowered by 1.7 μm.

[0052] Next, as shown in Fig. 8(c), precision grinding is performed on the workpiece W2. Specifically, in the precision grinding, the grinding surface of the precision grinding wheel 71 is pressed against the workpiece W2 while the precision grinding wheel 71 and the chuck 3 are both rotating, and precision grinding of the workpiece W1 is performed. When the workpiece W reaches a desired thickness, the precision grinding device 7 stops the rotation of the precision grinding wheel 71 and the chuck 3, retracts the precision grinding wheel 71 upward, and ends the precision grinding.

[0053] Next, the index table 2 rotates, the chuck 3 moves toward the alignment stage ST1, and after the suction between the workpiece W2 and the chuck 3 is released, the second arm 43 removes the workpiece W2 from the chuck 3 and transfers it to the second rack 44.

[0054] As the index table 2 rotates and the chuck 3 moves toward the alignment stage ST1, the fixed sensor 8 measures the film thickness of the workpiece W2 at multiple measurement points across the entire surface of the workpiece W2, thereby measuring the shape of the workpiece W2, as shown in Fig. 8(d). Fig. 9 shows the shape of the second workpiece W2 after precision grinding. Fig. 9 shows that the shape of the workpiece W1 after precision grinding substantially matches the substantially flat target shape.

[0055] For the third and subsequent workpieces W, it is possible to apply the correction angle obtained from the precision grinding results of the first workpiece W1, or to apply the correction angle obtained from the precision grinding results of the immediately preceding workpiece W. In the latter case, the inclination angle can be appropriately updated taking into account wear of the precision grinding wheel 71, etc.

[0056] In this way, the processing system 1 of the present invention is a processing system 1 that sequentially performs pre-grinding and fine grinding on the workpieces W1 and W2, and is equipped with a chuck 3 that rotatably holds the workpieces W1 and W2, an index table 2 that moves the workpieces W1 and W2 through the rough grinding stage ST2, the medium grinding stage ST3, the fine grinding stage ST4, and the alignment stage ST1 in that order, a tilt mechanism 33 that can adjust the inclination of the chuck 3, an oscillating sensor 72 that measures the shape of the workpieces W1 and W2 before fine grinding, a fixed sensor 8 that measures the shape of the workpiece W1 after fine grinding while the workpiece W1 after fine grinding is being transported to the alignment stage ST1, and a control device 9 that controls the inclination angle, which is the inclination of the chuck 3 during fine grinding, based on the shape of the workpieces W1 and W2 before fine grinding, and corrects the inclination angle when fine grinding the workpiece W2 based on the shape of the workpiece W1 after fine grinding.

[0057] With this configuration, the fixed sensor 8 quickly measures the shape of the first workpiece W1 after fine grinding, and the control device 9 calculates the correction angle during fine grinding so that the shape of the workpiece W1 after fine grinding can be machined to the desired target shape.The second workpiece W2 is then fine-ground while the inclination angle calculated from the shape of the second workpiece W2 before fine grinding is added with the correction angle corresponding to the fine grinding results of the first workpiece W1, thereby allowing the workpiece W2 to be machined efficiently and with high precision.

[0058] In addition, the processing system 1 of the present invention is configured so that the control device 9 calculates an inclination angle based on the shape of the workpiece W1 before fine grinding so that the shape of the workpiece W1 after fine grinding approximately matches the target shape of the workpiece W1, and calculates an inclination angle based on the shape of the workpiece W2 before fine grinding so that the shape of the workpiece W2 after fine grinding approximately matches the target shape of the workpiece W2.

[0059] This configuration allows the workpieces W1 and W2 to be precisely machined into the desired target shape after precision grinding.

[0060] In addition, the processing system 1 according to the present invention is configured such that the control device 9 calculates a correction angle based on the shape of the workpiece W1 after precision grinding so that the shape of the workpiece W1 after precision grinding approximately matches the target shape of the workpiece W1.

[0061] With this configuration, the correction angle when precision grinding the workpiece W2 is set according to the grinding amount of the precision grinding wheel 71 that matches the difference between the shape of the workpiece W1 after precision grinding and the target shape, thereby enabling the shape of the workpiece W2 to be processed with even greater precision.

[0062] Furthermore, the processing system 1 according to the present invention is configured such that the fixed sensor 8 is attached to the frame 1 a that straddles the index table 2 above.

[0063] With this configuration, the fixed sensor 8 can measure the shape of the workpiece W1 when the workpiece W1 passes under the fixed sensor 8, thereby minimizing the time required to measure the shape of the workpiece W1.

[0064] Furthermore, the processing system 1 according to the present invention is configured such that the fixed sensor 8 is disposed on the rotational orbit R through which the center O of the workpiece W1 passes when viewed from above.

[0065] With this configuration, the measurement point of the fixed sensor 8 is set on the rotational orbit R of the center O of the workpiece W1 when viewed from a plane, so that the shape of the workpiece W can be measured without reducing the throughput of the grinding process of the workpiece W.

[0066] Furthermore, the present invention can be modified in various ways other than those described above without departing from the spirit of the present invention, and it goes without saying that the present invention also covers such modifications.

[0067] For example, in the above-described embodiment, the tilt mechanism 33 is configured to tilt the chuck 3 together with the rotation axis 3a, but the tilt mechanism 33 may be configured to tilt only the chuck 3 without tilting the rotation axis 3a. [Explanation of symbols]

[0068] 1: Processing system 1a: Frame 2: Index table 2a: Rotation axis 3: Zipper 3a: Rotation axis 31: Rotating table 32: Adsorbent 33: Tilt mechanism 34: Tilt table 35:Fixed support part 36: First movable support part 37: Second movable support part 41: First arm 42: First rack 43: Second arm 44: Second rack 5: Rough grinding device 51: Rough grinding wheel 52: First spindle 53: First spindle feed mechanism 6: Medium grinding device 61: Second spindle 62: Second spindle feed mechanism 7: Precision grinding device 71: Fine grinding wheel 72: Swing type thickness sensor (first sensor) 73: Arm 74: Sensor head 75: Drive shaft 8: Fixed thickness sensor (second sensor) 9: Control device D: Rotation direction O: Center P1: Outer circumference position R: Rotation orbit (around the workpiece center) ST1: Alignment stage ST2: Rough grinding stage ST3: Medium grinding stage ST4: Precision grinding stage W, W1, W2: Work

Claims

1. A processing system that sequentially performs pre-grinding and fine grinding on a workpiece, an index table having a chuck for rotatably holding the workpiece, and moving the workpiece at least through a pre-grinding stage, a fine grinding stage, and an alignment stage in this order; a tilt mechanism capable of adjusting the tilt of the chuck; a first sensor for measuring the shape of the workpiece before fine grinding; a second sensor that measures the shape of the workpiece after precision grinding while the workpiece after precision grinding is being transported to the alignment stage; a control device that controls an inclination angle of the chuck during precision grinding based on the shape of the workpiece before precision grinding, and corrects the inclination angle when precision grinding a next workpiece based on the shape of the workpiece after precision grinding; A processing system comprising:

2. The machining system according to claim 1, wherein the control device calculates the inclination angle based on the shape of the workpiece before precision grinding so that the shape of the workpiece after precision grinding approximately matches the target shape of the workpiece.

3. The machining system according to claim 1 or 2, characterized in that the control device calculates a correction angle for correcting the inclination angle based on the shape of the workpiece after precision grinding so that the shape of the workpiece after precision grinding approximately matches the target shape of the workpiece.

4. 4. The machining system according to claim 1, wherein the second sensor is attached to a frame that is provided above the index table.

5. 5. The machining system according to claim 1, wherein the second sensor is disposed on a rotational orbit through which the center of the work passes in a plan view.

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