Processing system and method

Abstract

To provide a processing system and method capable of determining appropriateness of processing without impairing processing efficiency of the processing system.SOLUTION: A processing system 1 includes: a chuck table 3 that rotationally attracts and holds a workpiece W; an index table 2 that rotationally moves the chuck table 3 around a rotation axis 2a; a measuring device 7c that measures a film thickness of the workpiece W that passes while rotating from a precision-grinding stage ST3 toward a polishing stage ST4 in a non-contact manner; a measuring device 7d that measures a film thickness of the workpiece W that passes while rotating from the polishing stage ST4 toward a platform stage ST1 in a non-contact manner; and a control device 8 that calculates predicted shapes of the workpiece W before and after polishing on the basis of measurement results of the measuring devices 7c, 7d, and determines appropriateness of processing on the basis of a predicted polishing amount obtained from a difference in the predicted shape of the workpiece W before and after polishing and a pre-stored target polishing amount of the workpiece W.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a processing system and method for thinning a workpiece. [Background Art]

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

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

[0004] [Patent Document 1] Japanese Unexamined Patent Publication No. 2009-117648 [Summary of the Invention] [Problem to be Solved by the Invention]

[0005] However, as the processing efficiency of workpieces has improved, there has been a problem that the time required for measuring workpiece thickness after workpiece cleaning adversely affects throughput. In addition, since thickness measurement is performed after the workpiece is transferred from the chuck table, reprocessing of the workpiece cannot be performed even when the workpiece thickness is thicker than the target thickness.

[0006] Accordingly, a technical problem to be solved arises in order to determine whether processing is appropriate in a short time without impairing the processing efficiency of the workpiece, and the present invention aims to solve this problem. [Means for Solving the Problem]

[0007] To achieve the above objective, the processing system according to the present invention includes a chuck that rotatably holds a workpiece by suction, and at each stage processing Each processing An index table that moves the chuck to a predetermined position along a predetermined track, and the track processing Among the positions, processing Position and the predetermined processing The next position processing Between the position and the predetermined processing From the position to the next processing The system includes a plurality of measuring devices that non-contactively measure the film thickness of the workpiece as it rotates and passes along the trajectory toward a position, and a control device that calculates the predicted shapes of two of the workpieces based on two of the measurement results from each of the measuring devices, and determines the suitability of the machining based on the predicted machining amount obtained from the difference between the two predicted shapes of the workpieces and a pre-stored target machining amount for the workpiece.

[0008] Furthermore, in the machining system according to the present invention, if the control device determines that the machining is not appropriate, it is preferable to return the chuck on the track and machine the workpiece again.

[0009] Furthermore, in order to achieve the above objective, the processing method according to the present invention includes a chuck that rotatably holds a workpiece by suction, and at each stage processing Each processing An index table that moves the chuck to a predetermined position along a predetermined track, and the track processing Among the positions, processing Position and the predetermined processing The next position processing A machining method applied to a machining system comprising a plurality of measuring devices and a control device provided between a position and a predetermined position, wherein the plurality of measuring devices are located on the trajectory. processing Position and next processing Between the position and the predetermined processing From the position to the next processingThe film thickness of the workpiece is measured non-contactively as it passes through the position while rotating. The control device calculates the predicted shapes of the two workpieces based on two of the measurement results obtained from each measuring device. The control device then determines whether the machining is appropriate based on the predicted machining amount obtained from the difference between the two predicted shapes of the workpieces and the target machining amount of the workpiece stored in advance. [Effects of the Invention]

[0010] This invention makes it possible to determine the suitability of a process without impairing the processing efficiency of the processing system. [Brief explanation of the drawing]

[0011] [Figure 1] A plan view showing a processing system according to one embodiment of the present invention. [Figure 2] A schematic diagram showing the positional relationship of measurement points of a measuring device on a workpiece. [Figure 3] A schematic diagram showing the cross-sectional shape of a workpiece calculated based on measurements from a measuring device. [Modes for carrying out the invention]

[0012] One embodiment of the present invention will be described with reference to the drawings. In the following, when referring to the number, numerical values, quantities, ranges, etc., of components, unless specifically indicated or clearly limited to a particular number in principle, the number is not limited to that particular number and may be greater than or less than that number.

[0013] Furthermore, when referring to the shape, positional relationship, etc. of constituent elements, unless otherwise explicitly stated or it is clearly considered not to be so in principle, this includes things that are substantially similar or alike to those shapes, etc.

[0014] Further, in the drawings, characteristic portions may be exaggerated, for example by being enlarged for easier understanding of features, and the dimensional ratios and the like of constituent elements are not necessarily the same as those in actuality. Further, in cross-sectional views, hatching may be omitted for some constituent elements to make the cross-sectional structure of the constituent elements easier to understand.

[0015] Fig. 1 is a plan view showing the basic configuration of a processing system 1. The processing system 1 continuously performs grinding processing and polishing processing on a workpiece W. Note that the processing system 1 may also perform only either one of grinding processing or polishing processing.

[0016] The processing system 1 is provided with four stages: a platform stage ST1, a rough grinding stage ST2, a finish grinding stage ST3, and a polishing stage ST4.

[0017] The processing system 1 includes: an index table 2 that is rotatable clockwise in the plane of Fig. 1; and four chuck tables 3 that are spaced equally on a concentric circle centered on the rotating shaft 2a of the index table 2. As the index table 2 performs step rotation by 90° each time, the chuck tables 3 can be moved in the order of the platform stage ST1, the rough grinding stage ST2, the finish grinding stage ST3, and the polishing stage ST4.

[0018] In the chuck table 3, an adsorbent (not shown) made of a porous material such as alumina is embedded on the upper surface of a rotary table 31. The chuck table 3 includes a pipeline (not shown) that extends through the interior to the surface thereof. 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 placed on the chuck table 3 is suction-held on the chuck table 3. When the compressed air source or the water supply source is activated, the suction between the workpiece and the chuck table 3 is released.

[0019] 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. The chuck table 3 may also be equipped with a tilt mechanism (not shown) to tilt the rotary table 31.

[0020] On the platform stage ST1, the workpiece W before grinding is transported onto the chuck table 3 by a transport arm (not shown). The workpiece W is pre-positioned so that its orientation aligns with a predetermined direction.

[0021] The rough grinding stage ST2 is equipped with a rough grinding device 4. The rough grinding device 4 comprises 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.

[0022] For rough grinding, for example, a cup-shaped grinding wheel of #600 grit is used. The first spindle feed mechanism 42 consists of two linear guides 43 that guide the direction of movement of the first spindle 41, and a ball screw slider mechanism 44 that raises and lowers the first spindle 41.

[0023] Furthermore, the rough grinding device 4 is equipped with a first contact-type thickness measuring device 45. The first contact-type thickness measuring device 45 comprises a pair of detection arms 46 and 47, each equipped with a contact element at its tip.

[0024] During rough grinding, the contact of the detection arm 46 comes into contact with the upper surface of the workpiece W, and the contact of the detection arm 47 comes into contact with the upper surface of the chuck table 3. The thickness of the workpiece W can be measured from the difference in height detected by the contacts of the detection arms 46 and 47. The thickness (total 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 tape attached to one surface.

[0025] The precision grinding stage ST3 is equipped with a precision grinding device 5. The precision grinding device 5 comprises a precision grinding wheel (not shown), a second spindle 51 to which the precision grinding wheel is attached at its lower end and which rotatably supports the precision grinding wheel, and a second spindle feeding mechanism 52 that raises and lowers the second spindle 51 in the vertical direction.

[0026] For precision grinding, a cup-shaped grinding wheel of, for example, #4000 grit is used. The second spindle feed mechanism 52 consists of two linear guides 53 that guide the direction of movement of the second spindle 51, and a ball screw slider mechanism 54 that raises and lowers the second spindle 51.

[0027] Furthermore, the precision grinding device 5 is equipped with a second contact-type thickness measuring device 55. The second contact-type thickness measuring device 55 comprises a pair of detection arms 56 and 57, each equipped with a contact element at its tip.

[0028] During precision grinding, the contact of the detection arm 56 comes into contact with the upper surface of the workpiece W, and the contact of the detection arm 57 comes into contact with the upper surface of the chuck table 3. 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. The thickness (total thickness) of the workpiece W measured by the second contact-type thickness measuring device 55 includes the thickness of devices formed on one side of the workpiece W and protective tape attached to the back side.

[0029] The polishing stage ST4 is equipped with a polishing device 6. The polishing device 6 comprises a polishing head 61 to which a polishing pad (not shown) is attached to the lower end; a third spindle 62 to which the polishing head 61 is attached to the lower end and which rotatably supports the polishing head 61; and a third spindle feeding mechanism (not shown) that raises and lowers the third spindle 62 in the vertical direction.

[0030] The processing system 1 is equipped 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 or protective tape attached to one surface.

[0031] The film thickness measuring device 7 is fixed to a frame 1a installed within the processing system 1 and is positioned above the index table 2. The measurement point where the film thickness measuring device 7 measures the film thickness of the workpiece W is set on the rotational trajectory O of the central axis of the chuck table 3 when viewed from above.

[0032] Figure 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 Figure 2(a), the positional relationship of the measurement points of the film thickness measuring device 7 is illustrated when the rotation speed of the index table 2 is set to 20 deg / s, the rotation speed of the chuck table 3 is set to 400 rpm, and the sampling period of the film thickness measuring device 7 is set to 4 msec. As the workpiece W rotates and passes directly beneath the film thickness measuring device 7, the trajectory of the measurement points of the film thickness measuring device 7 extends across the entire surface of the workpiece W, including the center of the workpiece W. The trajectory of the measurement points of the film thickness measuring device 7 can be appropriately changed by adjusting the rotation speed of the index table 2, the rotation speed of the chuck table 3, and the sampling period of the film thickness measuring device 7a.

[0033] Furthermore, it is preferable that the film thickness measuring device 7 is equipped with a nozzle that blows air toward the surface of the workpiece W so that the cooling water at the measurement point is leveled to a substantially constant thickness.

[0034] One film thickness measuring device 7 is installed upstream of each stage ST1 to ST4 in the rotational direction of the index table 2. Hereafter, the four film thickness measuring devices 7 will be distinguished by designations 7a to 7d.

[0035] The operation of the machining system 1 is controlled by the control device 8. The control device 8 controls each of the components that make up the machining system 1. The control device 8 is composed of, for example, a CPU, memory, etc. The functions of the control device 8 may be realized by control using software or by operation using hardware.

[0036] Furthermore, the control device 8 can calculate the shape of the workpiece based on the measurements from the film thickness measuring device 7. Figure 3 shows the shape of the workpiece W calculated by the control device 8 based on the measurements from the film thickness measuring device 7. In Figure 3, the vertical axis is set to the film thickness of the workpiece W, and the horizontal axis is set to the radial dimension of the workpiece W (-150 to 150 mm). It can be seen that the workpiece W shown in Figure 3 has a concave shape where the periphery of the workpiece W is thicker than the rotation center of the workpiece W.

[0037] Next, we will explain the procedure for processing workpiece W.

[0038] [Rough grinding] On the platform stage ST1, the workpiece W is placed on the chuck table 3. When the vacuum source is activated, negative pressure is supplied between the workpiece W and the chuck table 3, causing the workpiece W to be held in place by suction to the chuck table 3.

[0039] Next, as the index table 2 rotates and the chuck table 3 moves toward the rough grinding stage ST2, the film thickness measuring device 7a measures the film thickness of the workpiece W before rough grinding as it rotates and passes directly beneath it.

[0040] The chuck table 3 moves to the rough grinding stage ST2, and rough grinding is performed on the workpiece W. During rough grinding, the grinding surface of the grinding wheel is pressed against the workpiece W while the rough grinding wheel and the chuck table 3 are rotated, and rough grinding is performed on the workpiece W. When the measurement value of the first contact-type thickness measuring device 45 reaches the desired thickness, the rough grinding device 4 terminates the rough grinding.

[0041] Next, as the index table 2 rotates and the chuck table 3 moves toward the precision grinding stage ST3, the film thickness measuring device 7b measures the film thickness of the workpiece W before precision grinding as it rotates and passes directly beneath it.

[0042] The control device 8 calculates the predicted shape of the workpiece W after rough grinding based on the measurement values ​​from the film thickness measuring device 7b.

[0043] The control device 8 then compares the predicted shape of the workpiece W after rough grinding with the pre-stored target shape of the workpiece W after rough grinding to determine whether the workpiece W has been properly rough ground.

[0044] Such a determination may be made, for example, by determining whether the average film thickness in the expected shape of the workpiece W after rough grinding falls within a predetermined error range compared to the average film thickness in the target shape of the workpiece W after rough grinding, but is not limited to this.

[0045] If the predicted shape of the workpiece W reaches the target shape, it is determined that the rough grinding process was performed appropriately. If the predicted shape of the workpiece W does not reach the target shape, it is determined that the rough grinding process was insufficient.

[0046] Furthermore, the control device 8 may be configured to determine whether or not rough grinding is appropriate by calculating the predicted shape of the workpiece W before and after rough grinding based on the measurements of the film thickness measuring devices 7a and 7b, and then determining whether or not rough grinding is appropriate from the predicted amount of material removed in rough grinding obtained from the difference between each predicted shape.

[0047] In this case, the control device 8 stores in advance the target grinding amount of the workpiece W during rough grinding. The control device 8 compares the expected grinding amount with the target grinding amount to determine whether the rough grinding is appropriate. If the expected grinding amount reaches the target grinding amount, it determines that the rough grinding has been performed appropriately. If the expected grinding amount does not reach the target grinding amount, it determines that the rough grinding has been insufficient.

[0048] Furthermore, by using the measurement values ​​from the first contact-type thickness measurement device 45 and the film thickness measuring device 7a, the consistency of the processing conditions (processing recipe) can be confirmed. Specifically, the thickness of the workpiece W excluding the Si layer can be obtained from the difference between the total thickness of the workpiece W (sum of the Si layer thickness, device layer thickness, and protective tape thickness) measured by the film thickness measuring device 7a before rough grinding and the Si layer thickness of the workpiece W measured by the film thickness measuring device 7a. Therefore, it is possible to check in advance whether the various settings included in the processing recipe are appropriate.

[0049] If it is determined that the rough grinding is insufficient, the index table 2 rotates counterclockwise as shown in Figure 1, the chuck table 3 returns to the rough grinding stage ST2, and the workpiece W is rough ground again.

[0050] [Precision grinding] If it is determined that the rough grinding has been performed properly, the index table 2 rotates and the chuck table 3 moves to the fine grinding stage ST3, and fine grinding is performed on the workpiece W. In fine grinding, with the fine grinding wheel and the chuck table 3 rotating respectively, the grinding surface of the fine grinding wheel is pressed against the workpiece W to perform fine grinding of the workpiece W. When the measurement value of the second contact-type thickness measuring device 55 reaches the desired thickness, the fine grinding device 5 terminates the fine grinding.

[0051] Next, as the index table 2 rotates and the chuck table 3 moves toward the polishing stage ST4, the film thickness measuring device 7c measures the film thickness of the workpiece W before polishing as it rotates and passes directly beneath it.

[0052] The control device 8 calculates the predicted shape of the workpiece W after precision grinding based on the measurement values ​​from the film thickness measuring device 7c.

[0053] The control device 8 then compares the predicted shape of the workpiece W after precision grinding with the pre-stored target shape of the workpiece W after precision grinding to determine whether the workpiece W has been properly precision ground. Such determination may be made, for example, by determining whether the average film thickness in the predicted shape of the workpiece W after precision grinding is within a predetermined error compared to the average film thickness in the target shape of the workpiece W after precision grinding, but is not limited to this.

[0054] If the predicted shape reaches the target shape, it is determined that the precision grinding process was performed appropriately. If the predicted shape does not reach the target shape, it is determined that the precision grinding process was insufficient.

[0055] Furthermore, the control device 8 may be configured to determine the suitability of rough grinding by calculating the predicted shape of the workpiece W before and after fine grinding based on the measurements of the film thickness measuring devices 7b and 7c, and then determining the suitability of fine grinding from the predicted amount of machining in fine grinding obtained from the difference between each predicted shape.

[0056] In this case, the control device 8 stores in advance the target grinding amount of the workpiece W during precision grinding. The control device 8 compares the expected grinding amount with the target grinding amount to determine whether the precision grinding is appropriate. If the expected grinding amount reaches the target grinding amount, it determines that the precision grinding has been performed appropriately. If the expected grinding amount does not reach the target grinding amount, it determines that the precision grinding has been insufficient.

[0057] If it is determined that the precision grinding is insufficient, the index table 2 rotates counterclockwise as shown in Figure 1, the chuck table 3 returns to the precision grinding stage ST3, and the workpiece W is precision ground again.

[0058] Furthermore, the determination of whether rough grinding and fine grinding are suitable may be performed together. Specifically, the control device 8 calculates the predicted shape of the workpiece W before rough grinding and the predicted shape of the workpiece W after fine grinding, respectively, based on the measurements of the film thickness measuring devices 7a and 7c, and determines whether grinding is suitable from the predicted amount of material removed in the grinding process (rough grinding and fine grinding) obtained from the difference between each predicted shape.

[0059] In this case, the control device 8 compares the expected amount of material removed during grinding with the target amount of material removed from the workpiece W, which has been stored in advance, to determine whether the grinding process is appropriate. If the expected amount of material removed reaches the target amount of material removed, the control device 8 determines that the grinding process was performed appropriately. If the expected amount of material removed does not reach the target amount of material removed, the control device 8 determines that the grinding process was insufficient.

[0060] If the grinding process is deemed insufficient, the index table 2 rotates clockwise as shown in Figure 1, and the chuck table 3 returns to the rough grinding stage ST2 or the fine grinding stage ST3, and the workpiece W is ground again.

[0061] [Polish] If it is determined that the precision grinding process has been performed properly, the index table 2 rotates, the chuck table 3 moves to the polishing stage ST4, and the workpiece W is polished. During the polishing process, the polishing pad and the chuck table 3 are rotated, and the lower surface of the polishing pad is pressed against the workpiece W to polish the workpiece W.

[0062] Then, as the index table 2 rotates and the chuck table 3 moves toward the platform stage ST1, the film thickness measuring device 7d measures the film thickness of the workpiece W.

[0063] The control device 8 calculates the predicted shape of the workpiece W after polishing based on the measurement values ​​from the film thickness measuring device 7d. The control device 8 also compares the predicted shape of the workpiece W with a pre-stored target shape of the workpiece W after polishing to determine whether the workpiece W has been processed to the desired shape. Such a determination may be made, for example, by determining whether the average film thickness of the predicted shape of the workpiece W after polishing falls within a predetermined error compared to the average film thickness of the target shape of the workpiece W after polishing, but is not limited to this.

[0064] If the predicted shape reaches the target shape, it is determined that the polishing was performed properly; if the predicted shape does not reach the target shape, it is determined that the polishing was insufficient.

[0065] Furthermore, the control device 8 may be configured to calculate the predicted shape of the workpiece W before polishing and the predicted shape of the workpiece W after polishing based on the measurements of the film thickness measuring devices 7c and 7d, and to determine whether polishing is appropriate based on the predicted amount of polishing obtained from the difference between each predicted shape.

[0066] In this case, the control device 8 stores in advance the target amount of polishing for the workpiece W during the polishing process. The control device 8 compares the expected amount of polishing with the target amount of polishing to determine whether the polishing process is appropriate. If the expected amount of polishing reaches the target amount of polishing, the control device 8 determines that the polishing process has been performed appropriately. If the expected amount of polishing does not reach the target amount of polishing, the control device 8 determines that the polishing process is insufficient.

[0067] If the polishing process is deemed insufficient, the index table 2 rotates counterclockwise as shown in Figure 1, and the workpiece W is polished again.

[0068] Then, when the control device 8 determines that the workpiece W has been processed to the target shape, the vacuum source stops, the water supply source or compressed air source starts, and the suction between the workpiece W and the chuck table 3 is released.

[0069] In this way, the film thickness of the workpiece W can be measured immediately after processing without hindering the operating rate of the processing system 1.

[0070] Furthermore, the film thickness measuring devices 7a to 7d measure the film thickness of the workpiece W without releasing the suction between the workpiece W and the chuck table 3. If the result of the measurement indicates that the expected shape of the workpiece W is thicker than the target shape, the workpiece W can be processed with high precision by grinding or polishing it again as appropriate.

[0071] Furthermore, if there is a machining tendency (such as convex or concave) that can be inferred from the expected shape of the workpiece W, the machining conditions may be corrected by tilting the chuck table 3 to cancel out that tendency.

[0072] Furthermore, by comparing the predicted grinding amount of the workpiece W during rough grinding obtained from the measurement values ​​of the film thickness measuring devices 7a and 7b with a pre-set rough grinding processing recipe, the grinding amount during the subsequent rough grinding of the workpiece W can be optimized, thereby stabilizing the strength of the workpiece W.

[0073] Furthermore, by comparing the predicted grinding amount of the workpiece W obtained from the measurement values ​​of the film thickness measuring devices 7b and 7c with a pre-set processing recipe for precision grinding, the grinding amount of the workpiece W to be processed afterward can be optimized, thereby stabilizing the strength of the workpiece W.

[0074] Furthermore, the processing system 1 is not limited to one equipped with all four film thickness measuring devices 7a to 7d; any combination that allows for film thickness measurement of the workpiece W at the desired timing may be selected.

[0075] For example, it is conceivable to determine the suitability of the entire process based solely on the shape of the workpiece W after grinding and polishing, without judging the suitability of individual processes. Specifically, the control device 8 calculates the predicted shape of the workpiece W after polishing based solely on the measurement values ​​of the film thickness measuring device 7d, compares the predicted shape of the workpiece W with a pre-stored target shape of the workpiece W after polishing, and determines whether the workpiece W has been processed to the desired shape, thereby determining the suitability of the entire process.

[0076] The following are some examples of processing systems. [1] A machining system for machining a workpiece into a desired shape, comprising: a chuck for holding a workpiece by suction; an index table for rotating the chuck on a predetermined track; a measuring device that, when viewed from a plane, is installed on the track between a previous machining position and a next machining position, and measures the thickness of the machined workpiece in a non-contact manner as it rotates on the chuck moving from the previous machining position toward the next machining position; and a control device that calculates the expected shape of the workpiece based on the measurement value of the measuring device, compares the expected shape of the workpiece with a pre-stored target shape of the machined workpiece, and determines whether the machining is appropriate. [2] The processing system according to [1], further comprising a grinding device for grinding the workpiece, wherein the measuring device measures the film thickness of the workpiece after grinding, and the control device compares the expected shape of the workpiece after grinding with a pre-stored target shape of the workpiece after grinding to determine whether the grinding process is appropriate. [3] If the control device determines that the grinding process is inappropriate, the grinding device grinds the workpiece again after the grinding process, as described in [2]. [4] The processing system according to [2], further comprising a polishing device for polishing the workpiece after grinding, wherein the measuring device measures the film thickness of the workpiece after polishing, and the control device compares the expected shape of the workpiece after polishing with a pre-stored target shape of the workpiece after polishing to determine whether the grinding and polishing process is appropriate. [5] If the control device determines that the polishing process is inappropriate, the polishing device polishes the workpiece again after polishing, the processing system according to [4]. [6] A machining system for machining a workpiece into a desired shape, comprising: a chuck for holding the workpiece by suction; an index table for rotating the chuck on a predetermined track; a first measuring device, positioned between a previous first machining position and a next second machining position on the track as viewed from a plane, for non-contact measurement of the thickness of the workpiece before machining as it rotates on the chuck as it rotates from the first machining position toward the second machining position; a second measuring device, positioned between a previous third machining position and a next fourth machining position on the track as viewed from a plane, for non-contact measurement of the thickness of the workpiece after machining as it rotates on the chuck as it rotates toward the fourth machining position; and a control device for determining the suitability of machining by comparing an expected machining amount, which is the difference between the measurement value of the first measuring device and the measurement value of the second measuring device, with a pre-stored target machining amount for machining.

[0077] Furthermore, the present invention can be modified in various ways other than those described above, as long as it does not depart from the spirit of the invention, and it goes without saying that the present invention extends to such modifications. Also, the embodiments and modifications described above may be combined with each other. [Explanation of Symbols]

[0078] 1: Processing System 2: Index Table 2a: Rotation axis 3: Chuck Table 31: Rotating Table 4: Rough grinding device 41: First spindle 42: First spindle feed mechanism 43: Linear guide (for rough grinding equipment) 44: Ball screw slider mechanism (for rough grinding equipment) 45: First contact-type thickness measuring device 46, 47: Detection arm 5:Precision grinding device 51: The second spindle 52: Second spindle feed mechanism 53: Linear guide (for precision grinding equipment) 54: Ball screw slider mechanism (for precision grinding equipment) 55: Second contact-type thickness measuring device 56, 57: Detection arm 6: Polishing equipment 61: Polishing head 62: The Third Spindle 7, 7a~7d: Film thickness measuring device 8: Control device ST1: Platform Stage ST2: Rough grinding stage ST3: Precision grinding stage ST4: Polishing Stage W: Work

Claims

1. A chuck that holds the workpiece rotatably by suction, An index table moves the chuck along a predetermined track to each machining position where machining is performed in each stage, A plurality of measuring devices non-contactively measure the film thickness of the workpiece as it rotates and passes along the trajectory from the predetermined processing position to the next processing position, between a predetermined processing position and the processing position following the predetermined processing position, A control device that calculates the predicted shapes of two workpieces based on two of the measurement results from each of the aforementioned measuring devices, and determines the suitability of machining based on the predicted machining amount obtained from the difference between the two predicted shapes of the workpieces and the target machining amount of the workpiece stored in advance, A processing system characterized by having the following features.

2. The machining system according to claim 1, characterized in that if the control device determines that the machining is not appropriate, it returns the chuck on the track and processes the workpiece again.

3. A machining method applicable to a machining system comprising: a chuck for rotatably holding a workpiece by suction; an index table for moving the chuck along a predetermined track to each machining position where machining is performed in each stage; a plurality of measuring devices provided between a predetermined machining position and the next machining position on the track; and a control device, The plurality of measuring devices each measure the film thickness of the workpiece in a non-contact manner as it rotates and passes through the trajectory between the predetermined processing position and the next processing position, from the predetermined processing position to the next processing position. The control device calculates the predicted shapes of the two workpieces based on two of the measurement results obtained by each measuring device, A machining method characterized in that the control device determines whether machining is appropriate based on the predicted machining amount obtained from the difference between the predicted shapes of two workpieces and the target machining amount of the workpiece stored in advance.

Images