Machining system

Abstract

To provide a machining system that is able to accurately machine a workpiece.SOLUTION: A machining system 1 includes: a tilt device capable of tilting a rotation axis 3a of a chuck 3 that holds a workpiece W; a film thickness measurement device 7 that measures a film thickness of the finely ground workpiece W; and a control device 8 that calculates a shape of the finely ground workpiece W, based on a measurement value of the film thickness measurement device 7, calculates a tilt angle of the tilt device so as to reduce the difference between a maximum thickness and a minimum thickness of the finely ground workpiece W, and tilts the chuck 3 by the tilt angle. The finely ground workpiece W having a film thickness obtained by adding a predetermined offset thickness to a final target thickness is re-machined in the following order, rough grinding, intermediate grinding, and fine grounding, while the chuck 3 is kept inclined by the inclination angle.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a processing system for thinly processing a workpiece.

Background Art

[0002] In the semiconductor manufacturing field, as a device for thinly and flatly grinding a semiconductor wafer such as a silicon wafer (hereinafter referred to as "workpiece"), a grinding device is known that presses the grinding surface of a rotating grinding wheel against the workpiece to grind the workpiece.

[0003] Patent Document 1 discloses an apparatus that processes a workpiece in the order of rough grinding and finish grinding, cleans the protective tape and the back surface of the workpiece, and then measures the thickness of the workpiece using a capacitance sensor.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, in order to process a workpiece with high precision, finish grinding of the workpiece may be temporarily stopped, the thickness of the workpiece may be measured, and then finish grinding may be performed again on the same workpiece based on the measurement result. However, these days, the grain size of the grinding wheel has become finer, and even if finish grinding is resumed after thickness measurement, the dressing of the grinding wheel is insufficient, the cutting ability of the grinding wheel deteriorates, and the shape of the workpiece after regrinding may become unstable or surface burning may occur.

[0006] Therefore, a technical problem to be solved in order to process a workpiece with high precision arises, and an object of the present invention is to solve this problem.

Means for Solving the Problems

[0007] In order to achieve the above object, a processing system according to the present invention is a processing system that processes a workpiece in the order of rough grinding and finish grinding, and includes a tilt device capable of tilting the rotation axis of a chuck that holds the workpiece, a measuring device that measures the film thickness of the workpiece after finish grinding, and calculates the shape of the workpiece after finish grinding based on the measured value of the measuring device, and calculates the tilt angle of the tilt device so that the difference between the maximum thickness and the minimum thickness of the workpiece after finish grinding becomes small, and a control device that tilts the chuck by the tilt angle. After finish grinding the workpiece with a film thickness obtained by adding a predetermined offset thickness to the final target thickness, reprocessing is performed in the order of rough grinding and finish grinding with the chuck tilted by the tilt angle.

[0008] According to this configuration, the measuring device measures the film thickness of the workpiece after the first-stage processing, and the control device calculates the tilt angle of the rotation axis of the chuck that can process the workpiece approximately flat from the shape of the workpiece after the first-stage processing. By re-performing rough grinding and finish grinding on the workpiece with the rotation axis of the chuck tilted by this tilt angle, even when the finish grinding wheel is fine, the finish grinding wheel is sharpened by rough grinding and the sharpness of the grinding wheel is maintained, so that the workpiece can be processed efficiently and with high precision.

Effect of the Invention

[0009] The present invention can process a workpiece with high accuracy.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiment for Carrying Out the Invention

[0011] An embodiment of the present invention will be described with reference to the drawings. In the following, when referring to the number of components, numerical values, amounts, ranges, etc., unless otherwise specified or limited to a specific number in principle, it is not limited to that specific number, and it may be more or less than the specific number.

[0012] Also, when referring to the shape, positional relationship, etc. of components, etc., unless otherwise specified or it is considered otherwise in principle, it includes those that are substantially approximate or similar to the shape, etc.

[0013] Also, the drawings may be exaggerated, such as enlarging characteristic parts for easy understanding of the characteristics, and the dimensional ratios of components are not necessarily the same as the actual ones. Also, in cross-sectional views, in order to make the cross-sectional structure of components easy to understand, the hatching of some components may be omitted.

[0014] FIG. 1 is a plan view showing the basic configuration of the processing system 1. The processing system 1 continuously performs a plurality of grinding processes on the workpiece W. Note that the processing system 1 may perform only one of grinding or polishing.

[0015] The processing system 1 is provided with four stages: a platform stage ST1, a rough grinding stage ST2, an intermediate grinding stage ST3, and a finish grinding stage ST4. Note that the number of stages (pre-grinding stages) for processing the workpiece W in order upstream of the finish grinding stage ST4 is not limited to the two stages of the rough grinding stage ST2 and the intermediate grinding stage ST3, and may be 1 or 3 or more.

[0016] The processing system 1 includes an index table 2 that can be rotated clockwise around the plane of FIG. 1, and four chucks 3 that are arranged at equal intervals concentrically around the rotation axis 2a of the index table 2. By the index table 2 rotating stepwise by 90° each time, the chuck 3 can move in the order of the platform stage ST1, rough grinding stage ST2, semi-finishing grinding stage ST3, and finish grinding stage ST4.

[0017] The chuck 3 has an absorber 32 made of a porous material such as alumina embedded in the upper surface of the rotary table 31. The chuck 3 is provided with a pipeline (not shown) that passes through the inside and extends to the surface. The pipeline 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. Also, when the compressed air source or the water supply source is activated, the adsorption between the workpiece W and the chuck 3 is released.

[0018] The rotary table 31 is connected to a chuck spindle (not shown). The chuck spindle is configured to be rotatably driven around a rotation axis perpendicular to the rotary table 31. Note that the chuck 3 may be provided with a tilt mechanism (not shown) that can tilt the rotary table 31 and is composed of a known configuration.

[0019] At the platform stage ST1, the workpiece W before grinding is conveyed onto the chuck 3 by a conveying arm (not shown). Positioning is performed in advance on the workpiece W so that its orientation coincides with a predetermined direction. Also, the workpiece W after grinding is carried out from the chuck 3 by the conveying arm to a cleaning device (not shown).

[0020] The rough grinding stage ST2 is provided with a rough grinding device 4. The rough grinding device 4 includes a rough grinding wheel (not shown), a first spindle 41 to which the rough grinding wheel is attached at the lower end and which rotatably supports the rough grinding wheel, and a first spindle feed mechanism 42 that raises and lowers the first spindle 41 in the vertical direction.

[0021] For rough grinding, a cup-shaped grinding wheel of, for example, #8000 is used. The first spindle feed mechanism 42 includes two linear guides 43 that guide the moving direction of the first spindle 41, and a ball screw slider mechanism 44 that raises and lowers the first spindle 41.

[0022] In addition, the rough grinding device 4 is provided with a first contact type thickness measuring device 45. The first contact type thickness measuring device 45 includes a pair of detection arms 46 and 47 provided with contacts at their tips.

[0023] During rough grinding, the contact of the detection arm 46 abuts on the upper surface of the workpiece W, and the contact of the detection arm 47 abuts on the upper surface of the chuck 3. Thus, the thickness of the workpiece W can be measured from the difference in height detected by each contact of the detection arms 46 and 47. Note that the thickness of the workpiece W measured by the first contact type thickness measuring device 45 includes the thickness of devices formed on one surface of the workpiece W and protective tapes adhered to one surface.

[0024] The intermediate grinding stage ST3 is provided with an intermediate grinding device 5. The intermediate grinding device 5 includes an intermediate grinding wheel (not shown), a second spindle 51 to which the intermediate grinding wheel is attached at its lower end and which rotatably supports the intermediate grinding wheel, and a second spindle feed mechanism 52 that raises and lowers the second spindle 51 in the vertical direction.

[0025] For the intermediate grinding wheel, a cup-shaped grinding wheel of, for example, #8000 is used. The second spindle feed mechanism 52 includes two linear guides 53 that guide the moving direction of the second spindle 51, and a ball screw slider mechanism 54 that raises and lowers the second spindle 51.

[0026] In addition, the intermediate grinding device 5 is provided with a second contact type thickness measuring device 55. The second contact type thickness measuring device 55 includes a pair of detection arms 56 and 57 provided with contacts at their tips.

[0027] During center grinding, the contacts of the detection arm 56 abut against the upper surface of the workpiece W, and the contacts of the detection arm 57 abut against the upper surface of the chuck 3. Thus, the thickness of the workpiece W can be measured from the difference in height detected by the contacts of the detection arms 56 and 57. Note that the thickness of the workpiece W measured by the second contact-type thickness measuring device 55 includes the thickness of devices formed on one surface of the workpiece W and protective tapes adhered to the back surface, etc.

[0028] The finish grinding stage ST4 is provided with a finish grinding device 6. The finish grinding device 6 includes a finish grinding wheel 61, a third spindle 62 to which the finish grinding wheel 61 is attached at the lower end and which rotatably supports the finish grinding wheel 61, and a third spindle feed mechanism (not shown) for raising and lowering the third spindle 62 in the vertical direction.

[0029] The finish grinding wheel 61 is, for example, a cup-shaped grinding wheel of #8000. The finish grinding stage ST4 is also provided with a non-contact type thickness measuring device 63 described later. The non-contact type thickness measuring device 63 measures the thickness (film thickness) of the workpiece W during finish grinding.

[0030] The processing system 1 is provided with a film thickness measuring device 7. The film thickness measuring device 7 measures the thickness (film thickness) of the workpiece W in a non-contact manner. Note that the film thickness of the workpiece W measured by the film thickness measuring device 7 does not include the thickness of devices formed on one surface of the workpiece W and protective tapes adhered to one surface, etc. The film thickness measuring device 7 is, for example, a spectroscopic interference type film thickness measuring instrument.

[0031] The film thickness measuring device 7 is fixed to the frame 1a installed in the processing system 1 and is installed above the index table 2. The measurement point at which the film thickness measuring device 7 measures the film thickness of the workpiece W is set on the rotation orbit O of the central axis of the chuck 3 when viewed from the plane.

[0032] FIG. 2 is a schematic diagram showing the positional relationship of the measurement points of the film thickness measuring device 7 on the workpiece W. In FIG. 2, the positional relationship of the measurement points of the film thickness measuring device 7 when the rotation speed of the index table 2 is set to 20 deg / s, the rotation speed of the chuck 3 is set to 400 rpm, and the sampling period of the film thickness measuring device 7 is set to 4 msec is illustrated. Since the workpiece W passes while rotating directly below the film thickness measuring device 7, the locus of the measurement points of the film thickness measuring device 7 includes the center of the workpiece W and spreads over the entire surface of the workpiece W. Note that the locus of the measurement points of the film thickness measuring device 7 can be appropriately changed according to the rotation speed of the index table 2, the rotation speed of the chuck 3, and the sampling period of the film thickness measuring device 7.

[0033] The film thickness measuring devices 7 are provided one each on the upstream side and the downstream side of the fine grinding stage ST4 in the rotation direction of the index table 2. This is because when transferring the processed workpiece W from the fine grinding stage ST4 to the platform stage ST1, due to the relationship of the rotation mechanism of the index table 2, the index table 2 may rotate clockwise or counterclockwise on the plane of FIG. 1, and in order to correspond to each rotation direction of the index table 2, the film thickness measuring devices 7 are provided one each on the upstream side and the downstream side of the fine grinding stage ST4.

[0034] The operation of the processing system 1 is controlled by the control device 8. The control device 8 controls each component constituting the processing system 1. The control device 8 is composed of, for example, a CPU, a memory, etc. Note that the functions of the control device 8 may be realized by controlling using software, or may be realized by operating using hardware.

[0035] Next, a procedure for sequentially processing two workpieces W with the same chuck will be described. Hereinafter, when distinguishing between two workpieces W, they are distinguished by attaching reference signs W1 and W2.

[0036] <The first workpiece (first-stage processing)> On the platform stage ST1, the workpiece W1 is placed on the chuck 3. 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.

[0037] Next, the index table 2 rotates, and the chuck 3 moves toward the rough grinding stage ST2.

[0038] The chuck 3 moves to the rough grinding stage ST2, and rough grinding of the workpiece W1 is performed. In rough grinding, with the rough grinding wheel and the chuck 3 rotating respectively, the grinding surface of the rough grinding wheel is pressed against the workpiece W1 to perform rough grinding of the workpiece W1. When the measured value of the first contact type thickness measuring device 45 reaches the desired thickness, the rough grinding device 4 stops the rotation of the rough grinding wheel and the chuck 3, retracts the rough grinding wheel upward, and finishes rough grinding.

[0039] Next, the index table 2 rotates, and the chuck 3 moves toward the semi - finishing grinding stage ST3. In the semi - finishing grinding stage ST3, semi - finishing grinding of the workpiece W1 is performed. In semi - finishing grinding, with the semi - finishing grinding wheel and the chuck 3 rotating respectively, the grinding surface of the semi - finishing grinding wheel is pressed against the workpiece W1 to perform semi - finishing grinding of the workpiece W1. When the measured value of the second contact type thickness measuring device 55 reaches the desired thickness, the semi - finishing grinding device 5 stops the rotation of the semi - finishing grinding wheel and the chuck 3, retracts the semi - finishing grinding wheel upward, and finishes semi - finishing grinding.

[0040] Next, the index table 2 rotates and the chuck 3 moves toward the fine grinding stage ST4. At the fine grinding stage ST4, fine grinding of the workpiece W1 is performed. Specifically, as shown in FIGS. 3(a) to 3(c), in the fine grinding process, with the fine grinding wheel 61 and the chuck 3 rotating respectively, the grinding surface of the fine grinding wheel 61 is pressed against the workpiece W1 to perform fine grinding of the workpiece W1. When the measured value of the non-contact thickness measuring device 63 reaches the desired thickness, the fine grinding device 6 stops the rotation of the fine grinding wheel 61 and the chuck 3, retracts the fine grinding wheel 61 upward, and finishes the fine grinding. Note that the measured value of the non-contact thickness measuring device 63 at the end of fine grinding is set to the final target thickness plus a predetermined offset thickness.

[0041] Next, when the index table 2 rotates and the chuck 3 moves toward the platform stage ST1, as shown in FIG. 3(d), the film thickness measuring device 7 measures the film thickness of the workpiece W1 at a plurality of measurement points across the entire surface of the workpiece W. The measurement points of the film thickness measuring device 7 on the workpiece W1 are set to, for example, 200 points. The film thickness measuring device 7 whose measurement points are set on the rotation orbit O of the central axis of the chuck 3 when viewed from the plane can measure the film thickness of the workpiece W1 without reducing the throughput of the grinding process of the workpiece W1 while the workpiece W1 rotates about the central axis of the chuck 3 and returns to the platform stage ST1.

[0042] Next, the control device 8 calculates the shape of the workpiece W1 after the fine grinding process based on the measured values of the film thickness measuring device 7. For example, the workpiece W1 illustrated in FIG. 3(d) has a concave shape with a thicker periphery than the center. The control device 8 calculates the tilt angle of the tilt mechanism so that the difference between the maximum value and the minimum value of the film thickness is small in the workpiece W1 processed for the first time. Note that the relationship between the shape of the workpiece W1 and the tilt angle of the tilt mechanism is preset by experiments or the like.

[0043] <The first workpiece (second-stage processing)> Next, rough grinding, semi-finishing grinding, and fine grinding are performed again on the workpiece W1 after fine grinding.

[0044] Specifically, the chuck 3 that holds the workpiece W1 after finish grinding moves in the order of the rough grinding stage ST2, the semi-finishing grinding stage ST3, and the finish grinding stage ST4, similar to the first-stage processing described above, and rough grinding, semi-finishing grinding, and finish grinding are sequentially performed on the workpiece W1 after finish grinding.

[0045] In the second-stage processing of the workpiece W1 after finish grinding in the rough grinding stage ST2, the semi-finishing grinding stage ST3, and the finish grinding stage ST4, as shown in FIGS. 4(a) and 4(b), the rotation axis 3a of the chuck 3 is inclined by the inclination angle of the tilt mechanism calculated based on the shape of the workpiece W1 after the first-stage finish grinding, and rough grinding, semi-finishing grinding, and finish grinding are performed.

[0046] Then, as shown in FIG. 4(c), when the measured value of the non-contact thickness measuring device 63 reaches the desired thickness, the finish grinding is terminated. Note that the measured value of the non-contact thickness measuring device 63 at the end of the finish grinding is set to the final target thickness.

[0047] Next, when the index table 2 rotates and the chuck 3 moves toward the platform stage ST1, as shown in FIG. 4(d), the film thickness measuring device 7 measures the film thickness at a plurality of measurement points across the entire surface of the workpiece W1.

[0048] Then, the control device 8 calculates the shape of the workpiece W1 after finish grinding based on the measured value of the film thickness measuring device 7. For example, the workpiece W1 illustrated in FIG. 4(d) is formed to be substantially flat with the difference between the maximum thickness and the minimum thickness being smaller than that of the workpiece W1 after the first-stage finish grinding. Further, the control device 8 calculates the inclination angle of the tilt mechanism so that the difference between the maximum value and the minimum value of the film thickness becomes smaller in the workpiece W1 after the second-stage processing.

[0049] In this way, when the surface roughness of the precision grinding wheel 61 is set to a finer value (about 3 to 4 nm) than the conventional value (about 10 to 13 nm), if the second-stage machining of the workpiece W1 after the first-stage machining is performed on the workpiece W1 after the first-stage machining with the precision grinding wheel 61 as in the conventional method, the cutting ability of the precision grinding wheel 61 is poor, and the shape of the workpiece W1 after the second-stage machining may become unstable or surface burning may occur. However, by performing the second-stage machining on the workpiece W1 after the first-stage machining in the order of rough grinding, semi-finishing grinding, and precision grinding, the precision grinding wheel 61 is sharpened and the cutting ability is maintained, so that the workpiece W1 can be stably machined.

[0050] Then, on the platform stage ST1, the adsorption and holding between the workpiece W1 and the chuck 3 are released, and the workpiece W1 is transferred from the chuck 3 to the cleaning device.

[0051] <The second workpiece> Next, the second workpiece W2 is adsorbed and held by the same chuck 3 as the first workpiece W1, and rough grinding and semi-finishing grinding are performed on the second workpiece W2 in the same manner as the rough grinding and semi-finishing grinding on the first workpiece W1 described above. In the rough grinding stage ST2 and the semi-finishing grinding stage ST3, the inclination angle of the rotation axis 3a of the chuck 3 is set to be substantially the same as when the first workpiece W1 was machined.

[0052] Thereafter, the index table 2 rotates, and the chuck 3 moves toward the precision grinding stage ST4. At the precision grinding stage ST4, precision grinding of the workpiece W1 is performed.

[0053] Specifically, as shown in Fig. 5(a), first, the rotation axis 3a of the chuck 3 is inclined by the inclination angle of the tilt mechanism calculated based on the shape of the workpiece W1 after the second-stage grinding. That is, in the rough grinding stage ST2 and the semi-finishing grinding stage ST3 where the general shape of the workpiece W is determined, the machining is carried out with the inclination angle of the rotation axis 3a of the chuck 3 set to be substantially the same with respect to the workpiece W. In contrast, in the finish grinding stage ST4 where the fine shape of the workpiece W is determined, when machining the second workpiece W2, the inclination angle of the rotation axis 3a of the chuck 3 is set considering the machining result of the first workpiece W1.

[0054] Next, as shown in Fig. 5(b), with the finish grinding wheel 61 and the chuck 3 rotated respectively, the grinding surface of the finish grinding wheel 61 is pressed against the workpiece W2 to perform finish grinding of the workpiece W2.

[0055] Then, when the measured value of the non-contact thickness measuring device 63 reaches the desired thickness, as shown in Fig. 5(c), the finish grinding device 6 stops the rotation of the finish grinding wheel 61 and the chuck 3, retracts the finish grinding wheel 61 upward, and finishes the finish grinding.

[0056] In this way, the film thickness measuring device 7 quickly measures the film thickness of the previously machined workpiece W1 after machining for the workpieces W1 and 2 continuously machined by the same chuck 3. The control device 8 calculates the inclination angle of the rotation axis 3a of the chuck 3 that can machine the workpiece W1 to be substantially flat from the shape of the workpiece W1. The finish grinding device 6 finishes grinding the workpiece W2 with the rotation axis 3a of the chuck 3 inclined by this inclination angle, so that the workpiece W2 can be efficiently and highly accurately machined based on the machining result of the workpiece W1.

[0057] Furthermore, in the rough grinding stage ST2 and the semi-finishing grinding stage ST3 where the general shape of the workpiece W is determined, machining is performed under the same conditions for any workpiece W. In the finish grinding stage ST4 where the fine shape of the workpiece W is determined, considering the shape of the previously machined workpiece W, the subsequent workpiece W is finish ground in an inclined state, so that a plurality of workpieces W can be stably and highly accurately machined.

[0058] Next, when the index table 2 rotates and the chuck 3 moves toward the platform stage ST1, as shown in FIG. 5(d), the film thickness measuring device 7 measures the film thickness of the work W2 at a plurality of measurement points across the entire surface of the work W2. The measurement points of the film thickness measuring device 7 on the work W2 are set to, for example, 200 points.

[0059] Then, the control device 8 calculates the shape of the work W2 after finish grinding based on the measured values of the film thickness measuring device 7. For example, the work W2 shown in FIG. 5(d) is formed to be substantially flat with the difference between the maximum thickness and the minimum thickness being smaller than that of the work W1.

[0060] Hereinafter, if necessary, for the third and subsequent works W as well, based on the shape of the work W that was most recently processed by the same chuck 3, the inclination angle of the rotation axis 3a of the chuck 3 that can be processed so that the difference between the maximum thickness and the minimum thickness in the most recently processed work W becomes small is calculated, and the grinding of the immediately subsequent work W is performed with the rotation axis 3a of the chuck 3 inclined by that inclination angle.

[0061] In this way, the processing system 1 according to the present invention is a processing system 1 that processes the work W in the order of rough grinding, intermediate grinding, and finish grinding, and includes a tilt device capable of inclining the rotation axis 3a of the chuck 3 that holds the work W, a film thickness measuring device 7 that non - contact measures the film thickness of the work W after finish grinding, a control device 8 that calculates the shape of the work W after finish grinding based on the measured values of the film thickness measuring device 7, calculates the inclination angle of the tilt device so that the difference between the maximum thickness and the minimum thickness in the work W after finish grinding becomes small, and inclines the chuck 3 by the inclination angle. The work W after finish grinding is configured to be re - processed in the order of rough grinding, intermediate grinding, and finish grinding with the chuck 3 inclined by the inclination angle.

[0062] With this configuration, the film thickness measuring device 7 quickly measures the film thickness of the workpiece W1 after the first-stage processing, and the control device 8 calculates the inclination angle of the rotation axis 3a of the chuck 3 that can process the workpiece W1 into a substantially flat shape from the shape of the workpiece W1. With the rotation axis 3a of the chuck 3 inclined by this inclination angle, rough grinding, semi-finishing grinding, and finish grinding are performed again on the workpiece W1. As a result, even when the grinding wheel of the finish grinding device 6 is fine, the cutting edge of the finish grinding wheel 61 is maintained by going through rough grinding and semi-finishing grinding, so that the workpiece W1 can be processed efficiently and with high precision.

[0063] Furthermore, by performing processing on the same workpiece W1 in two stages, at the time of film thickness measurement in the first stage, there is a possibility that thermal expansion and contraction of the chuck 3 and the like due to processing heat during grinding have not converged. In contrast, at the time of film thickness measurement in the second stage, thermal expansion and contraction of the chuck 3 and the like due to processing heat during grinding have converged, and the shape of the workpiece W1 can be accurately calculated.

[0064] In addition, the processing system 1 according to the present invention further includes an index table 2 that rotates and moves the chuck 3 on the orbit O, and the film thickness measuring device 7 is configured to be installed on the orbit O as viewed from a plane.

[0065] With this configuration, since the measurement point of the film thickness measuring device 7 is set on the orbit O of the index table 2 as viewed from a plane, the film thickness of the workpiece W can be measured without reducing the throughput of the grinding process of the workpiece W.

[0066] In addition, the present invention can make various modifications other than those described above without departing from the spirit of the present invention, and it is natural that the present invention extends to those modified ones.

Explanation of Reference Numerals

[0067] 1: Processing system 2: Index table 2a: Rotation axis (of the index table 2) 3: Chuck 3a: Rotation axis (of the chuck) 31: Rotating table 32: Adsorber 4: Rough grinding device 41: First spindle 42: First spindle feed mechanism 43: Linear guide (of the rough grinding device) 44: Ball screw slider mechanism (of the rough grinding device) 45: First contact type thickness measuring device 46, 47: Detection arm 5: Intermediate grinding device 51: Second spindle 52: Second spindle feed mechanism 53: Linear guide (of the intermediate grinding device) 54: Ball screw slider mechanism (of the intermediate grinding device) 55: Second contact type thickness measuring device 56, 57: Detection arm 6: Fine grinding device 61: Fine grinding wheel 62: Third spindle 63: Non-contact type thickness measuring device 7: Film thickness measuring device 8: Control device ST1: Platform stage ST2: Rough grinding stage ST3: Intermediate grinding stage ST4: Fine grinding stage W, W1, W2: Workpiece

Claims

1. A processing system for processing a workpiece in the order of pre-grinding and fine grinding, A tilt device capable of tilting a rotation axis of a chuck that holds the workpiece; A measuring device for measuring the film thickness of the workpiece after precision grinding; a control device that calculates a shape of the workpiece after the precision grinding based on the measurement value of the measuring device, calculates a tilt angle of the tilt device so that a difference between a maximum thickness and a minimum thickness of the workpiece after the precision grinding is reduced, and tilts the chuck by the tilt angle; Equipped with A processing system characterized by re-machining the workpiece after fine grinding, which has a film thickness of a final target thickness plus a predetermined offset thickness, in the order of pre-grinding and fine grinding, with the chuck tilted by the tilt angle.

2. An index table is further provided for rotating and moving the chuck on a predetermined track, The processing system according to claim 1 , wherein the measuring device is installed on the track when viewed from above.

Images