Processing device

Abstract

The invention provides a machining device which can restrain air consumption when cutting machining is not carried out. The control unit (7) has an X-axis distance detection unit (74), thereby detecting the distance between the chuck table (20) and the cutting blade (33). Furthermore, the control unit (7) causes the chuck table (20) and the cutting blade (33) to approach each other, and controls the flow rate adjustment valve (36) such that the air supply flow rate becomes a relatively small second flow rate until the distance between the chuck table (20) and the cutting blade (33) becomes a preset distance. Namely, even when the main shaft (30) is rotated, the air supply flow rate to the air bearing (40) is reduced when the load applied to the main shaft (30) without the cutting blade (33) being in contact with the wafer (100) is small. As a result, the consumption of air for forming the air bearing (40) can be suppressed when cutting is not performed.

Description

Technical Field

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

[0002] As disclosed in Patent Document 1, a cutting device has a cutting tool attached to the front end of a main spindle, and a workpiece is cut by the cutting tool which is rotated by the rotation of the main spindle. The main spindle is rotatably supported by an air bearing.

[0003] In the cutting device, before starting cutting processing, idling is performed to make the main shaft idle for a preset time (for example, 30 minutes). Then, after the idling is completed, cutting processing is started.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2001-259961

[0005] In the machining apparatus as described above, there is a technique for suppressing air consumption by cutting off the supply of air for forming an air bearing when the spindle is not rotating, that is, before the start of idling operation and after cutting.

[0006] However, during idling, an air bearing needs to be formed, so, for example, 200 L / min of air flows in. That is, even when cutting is not performed, the same amount of air as when cutting is performed is consumed. Summary of the invention

[0007] Therefore, an object of the present invention is to suppress the consumption of air when cutting is not performed.

[0008] The processing device of the present invention (this processing device) processes a workpiece, and the processing device comprises: a processing unit, which has a processing tool installed at the front end of a main shaft supported by an air bearing so as to be rotatable; a chuck worktable, which holds the workpiece; and a moving unit, which makes the processing unit and the chuck worktable relatively close to and away from each other, wherein the processing device comprises: a flow regulating valve, which is used to adjust the flow rate of air provided to form the air bearing; and a control unit, which moves the chuck worktable and the processing unit in a direction of relative proximity through the moving unit, and controls the flow regulating valve to make the air supply flow rate become a second flow rate less than the first flow rate until the processing tool contacts the workpiece, the air supply flow rate is the flow rate of air provided to form the air bearing, and the first flow rate is the flow rate of air when processing the workpiece.

[0009] In the processing device, the control unit can make the chuck table and the processing tool approach each other, and control the flow regulating valve to make the air supply flow rate become the second flow rate until the distance between the chuck table and the processing tool becomes a preset distance.

[0010] The processing device may include a rotation load detection unit for detecting the rotation load of the spindle, and the control unit may control the flow rate regulating valve to make the air supply flow rate become the second flow rate until the value of the rotation load detected by the rotation load detection unit becomes greater than a preset value.

[0011] The processing device may include a vibration sensor for detecting the vibration of the spindle, and the control unit may control the flow rate regulating valve to make the air supply flow rate the second flow rate until the value of the vibration detected by the vibration sensor becomes greater than a preset value.

[0012] In the processing device, the chuck table and the processing tool are moved in a direction in which they are relatively close, and the flow rate regulating valve is controlled so that the air supply flow rate to the air bearing becomes a second flow rate which is smaller than the air flow rate when the workpiece is processed, that is, the first flow rate. That is, in the processing device, even when the spindle is rotated, when the processing tool is not in contact with the workpiece and the load applied to the spindle is small, the air supply flow rate to the air bearing is reduced. Thereby, when processing is not performed, the spindle can be prevented from biting, and the consumption of air used for the formation of the air bearing can be suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a perspective view showing the structure of the cutting device.

[0014] Figure 2 It is an explanatory diagram showing the structure of a control unit, a chuck table, and a first cutting unit.

[0015] Figure 3 It is an explanatory diagram showing the structure of the spindle unit.

[0016] Figure 4 It is an explanatory diagram showing a cutting process.

[0017] Figure 5 It is an explanatory diagram showing the cutting process.

[0018] Figure 6 It is an explanatory diagram showing other cutting steps.

[0019] Figure 7 It is an explanatory diagram showing other cutting steps.

[0020] Figure 8It is a graph showing the time change of the distance between the chuck table and the cutting tool in the Z-axis direction and the air supply flow rate.

[0021] Fig. 9 It is a graph showing the time change of the load current value (or load value) and the air supply flow rate.

[0022] Description of symbols

[0023] 1: cutting device; 7: control unit; 10: base; 11: X-axis direction moving mechanism; 12: Y-axis direction moving mechanism; 13: cutting unit moving mechanism; 14: gate column; 16: first Z-axis direction moving mechanism; 17: second Z-axis direction moving mechanism; 18: first cutting unit; 19: second cutting unit; 20: chuck table; 21: table section; 22: holding surface; 23: frame; 24: holding member; 25: θ table; 28: fixture; 30: spindle; 31: motor; 33: cutting tool; 34: tool cover; 35: housing; 36: flow control valve; 37: air supply path; 38: cutting water nozzle; 40: air bearing; 41: thrust bearing; 42: radial bearing; 50: vibration sensor; 61: first tool detection section; 62: second tool detection section; 71: rotation load detection Detection unit; 72: vibration detection unit; 73: Z-axis distance detection unit; 74: X-axis distance detection unit; 100: wafer; 102: predetermined dividing line; 103: dicing tape; 105: annular frame; 107: workpiece group; 110: ball screw; 111: guide rail; 112: motor; 113: X-axis stage; 120: first ball screw; 121: guide rail; 122: second ball screw; 123: first A Y-axis stage; 124: a first motor; 125: a second Y-axis stage; 160: a ball screw; 161: a guide rail; 162: a motor; 163: a supporting member; 201: a suction source; 202: an air source; 203: a cutting water source; 211: a suction valve; 301: a first circular plate portion; 302: an axis portion; 311: a rotor; 312: a stator; 330: a flange; 331: a cutting tip; 351: a recess. DETAILED DESCRIPTION

[0024] Figure 1 The wafer 100 shown is an example of a workpiece and has a substantially disk shape. Grid-shaped planned dividing lines 102 are formed on the front surface of the wafer 100. Various devices (not shown) are formed in each region divided by the planned dividing lines 102.

[0025] A dicing tape 103 is attached to the back surface of the wafer 100. An annular frame 105 is attached to the outer periphery of the dicing tape 103. In this way, the wafer 100 is processed in the cutting device 1 in a state where the workpiece group 107 is supported by the annular frame 105 via the dicing tape 103.

[0026] The cutting device 1 is an example of a processing device that processes a wafer 100 as a workpiece. The cutting device 1 is a device called a so-called dual-axis saw, and performs cutting processing on the wafer 100. The cutting device 1 includes a base 10, a gate-shaped column 14 erected on the base 10, and a control unit 7 that controls each component of the cutting device 1.

[0027] An X-axis direction moving mechanism 11 is provided on the base 10. The X-axis direction moving mechanism 11 is an example of a moving unit that moves the first cutting unit 18 and the second cutting unit 19 as processing units relatively closer to and farther from the chuck table 20. The X-axis direction moving mechanism 11 moves the chuck table 20 along the cutting feed direction (X-axis direction).

[0028] The X-axis direction moving mechanism 11 includes: a pair of guide rails 111 extending in the X-axis direction; an X-axis stage 113 mounted on the guide rails 111 ; a ball screw 110 extending parallel to the guide rails 111 ; and a motor 112 for rotating the ball screw 110 .

[0029] A pair of guide rails 111 are arranged parallel to the X-axis direction on the upper surface of the base 10. The X-axis stage 113 is provided on the pair of guide rails 111 so as to be slidable along these guide rails 111. On the X-axis stage 113, the θ stage 25 and the chuck table 20 are arranged.

[0030] The ball screw 110 is screwed with a nut portion (not shown) provided on the X-axis stage 113. The motor 112 is connected to one end of the ball screw 110 to rotationally drive the ball screw 110. By rotationally driving the ball screw 110, the X-axis stage 113, the θ stage 25, and the chuck table 20 move along the guide rail 111 in the X-axis direction.

[0031] The chuck table 20 holds the wafer 100 as the workpiece. In this embodiment, the wafer 100 is held by the chuck table 20 in the state of the workpiece group 107. Figure 2 As shown, the chuck table 20 includes a table portion 21 formed in a disk shape and four clamps 28 .

[0032] The stage 21 has a substantially disk-shaped frame 23, and a holding member 24 made of a porous member such as porous ceramics is provided in a recessed portion provided on the upper surface of the frame 23. The upper surface of the holding member 24 serves as a holding surface 22 for sucking and holding the wafers 100 in the workpiece group 107.

[0033] In addition, the holding member 24 is connected to the suction source 201 via the suction valve 211. In the chuck table 20, by connecting the holding member 24 to the suction source 201, the wafer 100 of the workpiece group 107 is sucked and held by the holding surface 22 via the dicing tape 103. In addition, the annular frame 105 of the workpiece group 107 is clamped and fixed from four directions by the clamps 28. In this way, the chuck table 20 holds the workpiece group 107.

[0034] In addition, if Figure 1 As shown, the chuck table 20 is supported by a θ table 25 disposed on the bottom surface side of the chuck table 20. The θ table 25 is provided on the upper surface of the X-axis table 113 in a manner that allows rotation within the XY plane. Therefore, the θ table 25 can support the chuck table 20 and can rotationally drive the chuck table 20 within the XY plane.

[0035] On the rear side (−X direction side) of the base 10 , a gate-shaped column 14 is erected so as to straddle the X-axis direction moving mechanism 11 .

[0036] A cutting unit moving mechanism 13 is provided on the front surface (surface on the +X direction side) of the gate column 14 to move the first cutting unit 18 and the second cutting unit 19. The cutting unit moving mechanism 13 indexes and feeds the first cutting unit 18 and the second cutting unit 19 in the Y-axis direction and cuts and feeds them in the Z-axis direction.

[0037] The cutting unit moving mechanism 13 includes: a first Z-axis moving mechanism 16 that moves the first cutting unit 18 on the +Y direction side in the Z-axis direction; a second Z-axis moving mechanism 17 that moves the second cutting unit 19 on the -Y direction side in the Z-axis direction; and a Y-axis moving mechanism 12 that moves the first cutting unit 18 and the second cutting unit 19 in the Y-axis direction. The first Z-axis moving mechanism 16, the second Z-axis moving mechanism 17, and the Y-axis moving mechanism 12 are examples of moving units that move the first cutting unit 18 and the second cutting unit 19, which are machining units, relatively close to and away from the chuck table 20.

[0038] The Y-axis direction moving mechanism 12 is disposed on the front surface of the gate pillar 14. The Y-axis direction moving mechanism 12 reciprocates the first Z-axis direction moving mechanism 16 supporting the first cutting unit 18 and the second Z-axis direction moving mechanism 17 supporting the second cutting unit 19 in the Y-axis direction.

[0039] The Y-axis moving mechanism 12 includes: a pair of guide rails 121 extending along the Y-axis direction; a first Y-axis table 123 and a second Y-axis table 125 mounted on the guide rails 121; a first ball screw 120 and a second ball screw 122 extending parallel to the guide rails 121; a first motor 124 that rotates the first ball screw 120; and a second motor (not shown) that rotates the second ball screw 122.

[0040] A pair of guide rails 121 are arranged parallel to the Y-axis direction on the front surface of the gate-shaped column 14. A first Y-axis table 123 and a second Y-axis table 125 are provided on the pair of guide rails 121 in a manner that they can slide along these guide rails 121. A first Z-axis direction moving mechanism 16 and a first cutting unit 18 are mounted on the first Y-axis table 123. A second Z-axis direction moving mechanism 17 and a second cutting unit 19 are mounted on the second Y-axis table 125.

[0041] The first ball screw 120 is screwed with a nut portion (not shown) provided on the first Y-axis stage 123. The first motor 124 is connected to one end of the first ball screw 120 to rotationally drive the first ball screw 120. By rotationally driving the first ball screw 120, the first Y-axis stage 123, the first Z-axis direction moving mechanism 16, and the first cutting unit 18 move in the Y-axis direction along the guide rail 121.

[0042] Similarly, the second ball screw 122 is screwed with the nut portion (not shown) of the second Y-axis stage 125 and is driven to rotate by the second motor connected to one end of the nut portion. As a result, the second Y-axis stage 125, the second Z-axis direction moving mechanism 17 and the second cutting unit 19 move in the Y-axis direction along the guide rail 121.

[0043] The first Z-axis direction moving mechanism 16 moves the first cutting unit 18 back and forth in the Z-axis direction. The first Z-axis direction moving mechanism 16 includes: a pair of guide rails 161 extending in the Z-axis direction; a support member 163 disposed on the guide rails 161; a ball screw 160 extending parallel to the guide rails 161; and a motor 162 that rotates the ball screw 160.

[0044] The pair of guide rails 161 is arranged parallel to the Z-axis direction on the first Y-axis stage 123. The support member 163 is provided on the pair of guide rails 161 so as to be slidable along the guide rails 161. The first cutting unit 18 is mounted on the lower end of the support member 163.

[0045] The ball screw 160 is screwed with a nut portion (not shown) provided on the support member 163. The motor 162 is connected to one end of the ball screw 160 to rotationally drive the ball screw 160. By rotationally driving the ball screw 160, the support member 163 and the first cutting unit 18 move in the Z-axis direction along the guide rail 161.

[0046] The second Z-axis direction moving mechanism 17 also reciprocates the second cutting unit 19 in the Z-axis direction. The second Z-axis direction moving mechanism 17 has the same structure as the first Z-axis direction moving mechanism 16, and therefore, description thereof will be omitted.

[0047] The first cutting unit 18 and the second cutting unit 19 process the wafer 100 held by the chuck table 20 .

[0048] like Figure 2 As shown, the first cutting unit 18 includes: a spindle 30 extending in the Y-axis direction; a motor 31 driving the spindle 30 ; a cutting tool 33 mounted on the spindle 30 ; and a tool cover 34 surrounding the cutting tool 33 .

[0049] A cutting water nozzle 38 is provided on the tool cover 34. The cutting water nozzle 38 is connected to the cutting water source 203 and is configured to spray cutting water from obliquely upward toward a contact portion (processing point) between the cutting tool 33 and the wafer 100 during cutting.

[0050] The cutting tool 33 is an example of a processing tool. Figure 3 As shown, the cutting tool 33 has a disc-shaped flange 330 and an annular blade tip (cutting edge) 331 provided on the outer periphery of the flange 330. The front end of the spindle 30 is inserted and fixed in the center of the flange 330. The blade tip 331 is formed by fixing diamond abrasive grains or the like with an appropriate binder, for example.

[0051] The spindle 30 is supported by the housing 35. The spindle 30 extends in the Y-axis direction, and a cutting tool 33 is attached to the front end side of the spindle 30. The spindle 30 includes a first disk portion 301 having a relatively large diameter and a shaft portion 302 having a relatively small diameter.

[0052] The motor 31 is connected to the base end side of the main shaft 30. The motor 31 includes a rotor 311 provided at the rear end portion of the main shaft 30 and a stator 312. The stator 312 is provided on the inner peripheral surface of the housing 35.

[0053] The housing 35 surrounds the outer surface of the spindle 30. The housing 35 has an annular recessed portion 351 on the inner surface, and the first disc portion 301 of the spindle 30 is accommodated in the recessed portion 351.

[0054] In addition, the housing 35 is configured to support the spindle 30 so that it can rotate freely. Specifically, the housing 35 has an air supply path 37 connected to the air source 202 via a flow control valve (flow controller) 36. High-pressure air from the air source 202 is supplied between the housing 35 and the spindle 30 via the flow control valve 36 and the air supply path 37, thereby forming an air bearing 40 between the first disc portion 301 and the shaft portion 302 of the spindle 30 and the housing 35, and the spindle 30 is floatingly supported relative to the housing 35 by air. That is, the spindle 30 is supported by the air bearing 40 so that it can rotate in a non-contact state with the housing 35.

[0055] Then, in this state, the motor 31 drives the spindle 30 to rotate at a high speed, so that the cutting tool 33 rotates at a high speed, and the wafer 100 is cut.

[0056] As described above, in the present embodiment, the spindle 30 , the motor 31 , the cutting tool 33 , and the housing 35 constitute a spindle unit of the first cutting unit 18 .

[0057] In addition, in the present embodiment, the air bearing 40 includes: a thrust bearing 41 formed between the first disc portion 301 of the main shaft 30 and the housing 35 (recess 351); and a radial bearing 42 formed between the shaft portion 302 of the main shaft 30 and the housing 35. In addition, the flow regulating valve 36 is a component for adjusting the flow rate of air provided between the housing 35 and the main shaft 30 in order to form the air bearing 40 (the flow rate of air for forming the air bearing 40). That is, the flow rate of air provided from the air source 202 to between the housing 35 and the main shaft 30 (air bearing 40) can be adjusted by the flow regulating valve 36.

[0058] The second cutting unit 19 is also a processing unit similar to the first cutting unit 18, and cuts the wafer 100 held by the chuck table 20. The second cutting unit 19 has the same structure as the first cutting unit 18, and thus description thereof is omitted.

[0059] As described above, the first cutting unit 18 and the second cutting unit 19 are machining units in which the cutting tool 33 as a machining tool is attached to the front end of the spindle 30 rotatably supported by the air bearing 40 .

[0060] In addition, if Figure 2 As shown, the first cutting unit 18 has a vibration sensor 50 for detecting vibration of the spindle 30. The vibration sensor 50 is disposed in the housing 35, for example.

[0061] Furthermore, first and second tool detectors 61 and 62 are provided below the first and second cutting units 18 and 19 on the base 10. The first and second tool detectors 61 and 62 are used to detect the outer diameters of the cutting tools 33 in the first and second cutting units 18 and 19, respectively.

[0062] Figure 1 and Figure 2 The control unit 7 shown in the figure includes a CPU that performs calculation processing according to a control program, a storage medium such as a memory, etc. The control unit 7 executes various processes and controls each component of the cutting device 1 .

[0063] In addition, if Figure 2 As shown, the control unit 7 has a rotation load detection unit 71, a vibration detection unit 72, a Z-axis distance detection unit 73 and an X-axis distance detection unit 74, which are used to adjust the flow rate of air provided to the air bearing 40 between the housing 35 and the spindle 30, that is, the flow rate of air used to form the air bearing 40.

[0064] Next, a method of cutting the wafer 100 controlled by the control unit 7 will be described.

[0065] (1) Maintaining process

[0066] First, the control unit 7 or an operator places the workpiece group 107 on the holding surface 22 of the chuck table 20 .

[0067] Then, if Figure 2 As shown, the control unit 7 opens the suction valve 211 to connect the suction source 201 to the holding member 24 of the chuck table 20, thereby using the upper surface of the holding member 24, that is, the holding surface 22, to suck and hold the wafer 100 of the workpiece group 107 through the dicing tape 103. In addition, the control unit 7 holds the annular frame 105 of the workpiece group 107 by the clamp 28 and lowers it downward relative to the holding surface 22. In this way, the workpiece group 107 including the wafer 100 is held by the chuck table 20.

[0068]

Cutting process

[0069] In this process, a processing groove is formed on the wafer 100 by the first cutting unit 18 (or the second cutting unit 19 ).

[0070] Specifically, first, the control unit 7 uses Figure 1 The X-axis direction moving mechanism 11, the Y-axis direction moving mechanism 12 and the θ stage 25 shown in the figure adjust the positions of the chuck table 20 and the first cutting unit 18, so that the position of the first cutting unit 18 relative to the wafer 100 is set to Figure 2 The first initial position is shown.

[0071] When the first cutting unit 18 is arranged at the first initial position, the cutting tool 33 of the first cutting unit 18 is arranged at a position higher than the upper surface of the wafer 100 and away from the upper +X direction side of the wafer 100. In addition, the orientation and position of the cutting tool 33 are consistent with one of the predetermined dividing lines 102 (see Figure 1 ) to align.

[0072] In addition, the control unit 7 controls the flow regulating valve 36 so that the air source 202 is connected to the air supply path 37 (see Figure 3 ) is connected. As a result, high-pressure air from the air source 202 is supplied between the housing 35 and the spindle 30 to form an air bearing 40, and the spindle 30 is rotatably supported by the air bearing 40.

[0073] At this time, the control unit 7 controls the flow regulating valve 36 so that the flow rate of air supplied between the housing 35 and the spindle 30 (the flow rate of air for forming the air bearing 40), i.e., the air supply flow rate, is set to the second flow rate. The second flow rate is a flow rate that is smaller than the first flow rate (for example, 20% to 40% of the first flow rate) as the air supply flow rate when cutting the wafer 100. However, the second flow rate is set to an amount that can form the air bearing 40 that can support the spindle 30 so that it can rotate.

[0074] Then, the control unit 7 rotates the spindle 30 by means of the motor 31 to rotate the cutting tool 33. Figure 4 As shown, the control unit 7 lowers the first cutting unit 18 as indicated by arrow 501 through the first Z-axis direction moving mechanism 16. In the present embodiment, the control unit 7 lowers the lower end of the cutting tool 33 of the first cutting unit 18 to a position where the wafer 100 can be cut. In addition, the control unit 7 also controls the flow regulating valve 36 at this stage to maintain the flow rate (air supply flow rate) of the air supplied to the air bearing 40 between the housing 35 and the spindle 30 at the second flow rate.

[0075] Then, if Figure 5 As shown, the control unit 7 uses the X-axis direction moving mechanism 11 to move the chuck table 20 in the extending direction of the predetermined dividing line 102, that is, the X-axis direction (arrow 502), so that the cutting tool 33 cuts into the predetermined dividing line 102. As a result, a machining groove with a depth of cutting the wafer 100 is formed along the predetermined dividing line 102, and the wafer 100 is cut.

[0076] In this way, the control unit 7 forms processing grooves on the wafer 100 along all the planned dividing lines 102, and cuts the wafer 100 along these lines. Thus, the wafer 100 is divided into a plurality of chips.

[0077] In addition, when the chuck table 20 is moved in the X-axis direction using the X-axis direction moving mechanism 11, the control unit 7 controls the air supply flow rate using the X-axis distance detection unit 74. The X-axis distance detection unit 74 is used to detect the distance between the chuck table 20 and the cutting tool 33 in the X-axis direction. Specifically, when the chuck table 20 and the cutting tool 33 are brought close to each other using the X-axis direction moving mechanism 11, the control unit 7 uses the X-axis distance detection unit 74 to determine whether the distance between the chuck table 20 and the cutting tool 33 in the X-axis direction has reached a first predetermined distance. The first predetermined distance is the distance between the chuck table 20 and the cutting tool 33 when the cutting tool 33 can contact the wafer 100 of the workpiece group 107 held by the chuck table 20.

[0078] When the control unit 7 determines that the distance between the chuck table 20 and the cutting tool 33 is longer than the first predetermined distance, it determines that the cutting tool 33 is not in contact with the wafer 100 and controls the flow regulating valve 36 to maintain the air supply flow rate to the air bearing 40 at the second flow rate.

[0079] On the other hand, when the control unit 7 determines that the distance between the chuck worktable 20 and the cutting tool 33 has become the first specified distance, it determines that the cutting tool 33 is in contact with the chip 100, and controls the flow adjustment valve 36 to change the air supply flow rate to the air bearing 40 to a first flow rate that is greater than the second flow rate (the air supply flow rate when cutting the chip 100).

[0080] As described above, in this embodiment, the control unit 7 moves the chuck table 20 and the cutting tool 33 of the first cutting unit 18 in a relatively close direction through the X-axis direction moving mechanism 11, and controls the flow adjustment valve 36 so that the flow rate of air provided to form the air bearing 40, that is, the air supply flow rate, becomes a second flow rate that is less than the flow rate of air when the chip 100 is cut, that is, the first flow rate, until the cutting tool 33 contacts the chip 100.

[0081] That is, the cutting device 1 has an X-axis distance detection unit 74, and the control unit 7 detects the distance between the chuck table 20 and the cutting tool 33 in the X-axis direction through the X-axis distance detection unit 74. Then, the control unit 7 brings the chuck table 20 and the cutting tool 33 closer to each other, and controls the flow regulating valve 36 to make the air supply flow rate become a second relatively small flow rate until the distance between the chuck table 20 and the cutting tool 33 becomes a preset distance (first predetermined distance).

[0082] Thus, in the present embodiment, even when the spindle 30 is rotated, when the cutting tool 33 is not in contact with the wafer 100 and the load applied to the spindle 30 is small, the air supply flow rate to the air bearing 40 is reduced. Thus, when the cutting process is not performed, the spindle 30 is prevented from biting (contacting the housing 35), and the consumption of air for forming the air bearing 40 can be suppressed.

[0083] In addition, when the distance between the chuck table 20 and the cutting tool 33 reaches the first predetermined distance, the control unit 7 determines that the cutting tool 33 is in contact with the wafer 100, and changes the air supply flow rate to a first flow rate greater than the second flow rate. Thus, the cutting process of the cutting tool 33 can be well performed in a state where the supporting force of the air bearing 40 on the spindle 30 is increased.

[0084] In the above configuration, the control unit 7 lowers the first cutting unit 18 by the first Z-axis direction moving mechanism 16 in a state where the cutting tool 33 is away from the upper +X direction side of the wafer 100 ( Figure 4 ), and then the chuck table 20 is moved in the +X direction by the X-axis direction moving mechanism 11 ( Figure 5 ), thereby making the cutting tool 33 contact with the wafer 100. In this regard, in the present embodiment, the first cutting unit 18 may be lowered by the first Z-axis direction moving mechanism 16 while the cutting tool 33 is arranged above the wafer 100, thereby making the cutting tool 33 contact with the wafer 100.

[0085] In this structure, the control unit 7 uses Figure 1 The X-axis direction moving mechanism 11, the Y-axis direction moving mechanism 12 and the θ stage 25 shown in the figure are used to adjust the positions of the chuck table 20 and the first cutting unit 18, thereby setting the position of the first cutting unit 18 relative to the wafer 100 to Figure 6 The second initial position is shown.

[0086] If the Figure 6 As shown in FIG. 1 , when the first cutting unit 18 is configured in the second initial position, the cutting tool 33 is configured above the outer peripheral portion of the wafer 100. In addition, the orientation and position of the cutting tool 33 are consistent with a predetermined dividing line 102 (see FIG. 1 ) in the wafer 100. Figure 1 ) to align.

[0087] In addition, the control unit 7 controls the flow rate regulating valve 36 so that the air source 202 and the air supply path 37 (see Figure 3), thereby providing high-pressure air from the air source 202 between the housing 35 and the spindle 30 to form an air bearing 40, and the spindle 30 is rotatably supported by the air bearing 40. At this time, the control unit 7 controls the flow regulating valve 36 to set the air supply flow rate to a relatively small second flow rate.

[0088] Afterwards, the control unit 7 rotates the spindle 30 and the cutting tool 33 through the motor 31, as shown in FIG. Figure 7 As shown, the first Z-axis direction moving mechanism 16 lowers the first cutting unit 18 as indicated by arrow 503, so that the cutting blade 33 cuts into the planned dividing line 102 of the wafer 100. In this embodiment, the control unit 7 lowers the lower end of the cutting blade 33 to a position where the wafer 100 can be cut.

[0089] Figure 8 1 is a graph showing time changes in the distance L between the chuck table 20 and the cutting tool 33 in the Z-axis direction and the air supply flow rate R. In the example shown in the figure, the control unit 7 starts lowering the first cutting unit 18 at time T1.

[0090] In addition, the control unit 7 uses the first Z-axis direction moving mechanism 16 to lower the first cutting unit 18. Figure 6 The Z-axis distance detection unit 73 shown in the figure is used to control the air supply flow rate. The Z-axis distance detection unit 73 is used to detect the distance between the chuck table 20 and the cutting tool 33 in the Z-axis direction. Specifically, when the chuck table 20 and the cutting tool 33 are brought close to each other using the first Z-axis direction moving mechanism 16, the control unit 7 uses the Z-axis distance detection unit 73 to determine whether the distance between the chuck table 20 and the cutting tool 33 in the Z-axis direction has reached a second predetermined distance. The second predetermined distance is the distance between the chuck table 20 and the cutting tool 33 when the cutting tool 33 can contact the wafer 100 of the workpiece group 107 held by the chuck table 20.

[0091] Then, the control unit 7 determines that the distance L between the chuck table 20 and the cutting tool 33 in the Z-axis direction is greater than the second predetermined distance ( Figure 8 When the distance L1 in FIG. 1 is long, it is determined that the cutting tool 33 is not in contact with the wafer 100, and the flow rate regulating valve 36 is controlled to maintain the air supply flow rate to the air bearing 40 at the second flow rate.

[0092] On the other hand, when the control unit 7 determines that the distance L between the chuck table 20 and the cutting tool 33 in the Z-axis direction has reached the second predetermined distance (L1), Figure 8 At time T2 in the figure, it is determined that the cutting tool 33 is in contact with the wafer 100, and the flow rate regulating valve 36 is controlled to change the air supply flow rate to the air bearing 40 to a flow rate greater than the second flow rate ( Figure 8The first flow ( Figure 8 The flow rate in R1).

[0093] After the first cutting unit 18 is lowered ( Figure 8 At time T3 in the figure, the control unit 7 uses the X-axis direction moving mechanism 11 to move the chuck table 20 in the X-axis direction, and cuts the wafer 100 along the planned cutting lines 102. In this way, the control unit 7 forms processing grooves on the wafer 100 along all the planned cutting lines 102, and cuts the wafer 100 along these lines. In this way, the wafer 100 is divided into a plurality of chips.

[0094] In this structure, the cutting device 1 has a Z-axis distance detection unit 73, and the control unit 7 detects the distance between the chuck table 20 and the cutting tool 33 in the Z-axis direction through the Z-axis distance detection unit 73. In addition, the control unit 7 makes the chuck table 20 and the cutting tool 33 approach each other, and controls the flow adjustment valve 36 to make the air supply flow rate become a relatively small second flow rate until the distance between the chuck table 20 and the cutting tool 33 becomes a preset distance (second predetermined distance). As a result, when the cutting process is not performed, the spindle 30 can be prevented from biting, and the consumption of air for forming the air bearing 40 can be suppressed.

[0095] When the distance between the chuck table 20 and the cutting tool 33 reaches the second predetermined distance, the control unit 7 determines that the cutting tool 33 is in contact with the wafer 100 and changes the air supply flow rate to a first flow rate greater than the second flow rate.

[0096] Thus, in this embodiment, the cutting device 1 has a distance detection unit (Z-axis distance detection unit 73 and X-axis distance detection unit 74) for detecting the distance between the chuck table 20 and the processing tool, i.e., the cutting tool 33, and the control unit 7 brings the chuck table 20 and the cutting tool 33 closer to each other, and controls the flow regulating valve 36 to make the air supply flow rate become a second relatively small flow rate until the distance between the chuck table 20 and the cutting tool 33 becomes a preset distance (first predetermined distance or second predetermined distance). Thus, good cutting processing and suppression of air consumption can be achieved.

[0097] In addition, in the above-mentioned embodiment, the control unit 7 switches the air supply flow rate from the second flow rate to the first flow rate according to the distance between the chuck table 20 and the cutting tool 33 detected by the Z-axis distance detection unit 73 or the X-axis distance detection unit 74. Figure 2 The air supply flow rate is controlled by the rotation load detection unit 71 shown in the figure.

[0098] The rotation load detection unit 71 is used to detect the rotation load of the main shaft 30. In this embodiment, the rotation load detection unit 71 detects the rotation load provided to the motor 31 (see Figure 3 ) is used as the rotational load of the main shaft 30.

[0099] Specifically, when the cutting tool 33 contacts the wafer 100, a rotational load that slows down the rotational speed is generated on the spindle 30. Therefore, in order to maintain the preset rotational speed, the load current value of the motor 31 increases. The rotational load detection unit 71 measures the load current value of the motor 31 that changes in this way.

[0100] In this structure, the control unit 7 firstly performs the following operations, for example Figure 6 The first cutting unit 18 is arranged at the second initial position shown, and the air supply flow rate to the air bearing 40 is set to a relatively small second flow rate. Then, the control unit 7 lowers the first cutting unit 18 through the cutting unit moving mechanism 13, so that the chuck table 20 and the cutting tool 33 are close to each other.

[0101] Fig. 9 : is a graph showing the time changes of the load current value I and the air supply flow rate R. In the example shown in the figure, at time T11, the control unit 7 starts to increase the load current value I of the motor 31 of the first cutting unit 18.

[0102] When the first cutting unit 18 is lowered, the control unit 7 uses the rotation load detection unit 71 to determine whether the load current value I is greater than a preset value (predetermined value). Fig. 9 When the current value I1 in FIG. 1 is reached, it is determined that the cutting tool 33 is not in contact with the wafer 100, and the flow rate regulating valve 36 is controlled to maintain the air supply flow rate to the air bearing 40 at the second flow rate.

[0103] On the other hand, when the control unit 7 determines that the load current value I is equal to or greater than the predetermined value I1 ( Fig. 9 At time T12 in the figure, it is determined that the cutting tool 33 is in contact with the wafer 100, and the flow rate regulating valve 36 is controlled to change the air supply flow rate R to the air bearing 40 to a first flow rate R1 that is greater than the second flow rate R2.

[0104] Moreover, after the first cutting unit 18 is lowered ( Fig. 9 At time T13 in FIG. 1 , the control unit 7 uses the X-axis direction moving mechanism 11 to move the chuck table 20 in the X-axis direction to cut the wafer 100 along the planned dividing line 102 .

[0105] Thus, in this structure, the cutting device 1 has a rotation load detection unit 71 for detecting the rotation load of the spindle 30, and the control unit 7 detects the load current value of the motor 31 through the rotation load detection unit 71. Furthermore, the control unit 7 controls the flow rate adjustment valve 36 to make the air supply flow rate a relatively small second flow rate until the value of the rotation load (load current value) detected by the rotation load detection unit 71 becomes greater than a predetermined value. Thus, when the cutting process is not performed, the spindle 30 can be prevented from being bitten, and the consumption of air for forming the air bearing 40 can be suppressed.

[0106] When the load current value becomes equal to or greater than a predetermined value, the control unit 7 determines that the cutting tool 33 is in contact with the wafer 100 and changes the air supply flow rate to the first flow rate greater than the second flow rate.

[0107] In addition, the rotation load detection unit 71 may be configured to detect a load value applied to the spindle 30 as the rotation load of the spindle 30. The load value applied to the spindle 30 increases due to the contact between the cutting tool 33 and the wafer 100, etc. The rotation load detection unit 71 measures the load value that changes in this way.

[0108] In this case, if Fig. 9 As shown, before the load value F detected by the rotation load detection unit 71 becomes equal to or greater than the predetermined value F1, the control unit 7 determines that the cutting tool 33 is not in contact with the wafer 100, and controls the flow rate adjustment valve 36 to make the air supply flow rate R become a relatively small second flow rate R2. Thus, when the cutting process is not performed, the spindle 30 can be prevented from being seized, and the consumption of air for forming the air bearing 40 can be suppressed.

[0109] When the load value F becomes equal to or greater than the predetermined value F1, the control unit 7 determines that the cutting tool 33 is in contact with the wafer 100 and changes the air supply flow rate R to the first flow rate R1 which is greater than the second flow rate R2. Thus, the cutting tool 33 can perform cutting processing well.

[0110] In addition, the control unit 7 can also use Figure 2 The air supply flow rate is controlled by the vibration sensor 50 and the vibration detection unit 72 shown in the figure. Specifically, the value of the vibration (vibration value) generated in the spindle 30 increases due to the contact between the cutting tool 33 and the wafer 100, etc. The vibration sensor 50 detects (measures) the vibration value of the spindle 30 that changes in this way. And, the vibration detection unit 72, for example, controls the operation of the vibration sensor 50, and transmits the vibration value detected by the vibration sensor 50 to the control unit 7.

[0111] In this structure, the control unit 7 first arranges the first cutting unit 18 at, for example, Figure 6At the second initial position shown, the air supply flow rate to the air bearing 40 is set to a relatively small second flow rate. Then, the control unit 7 lowers the first cutting unit 18 through the cutting unit moving mechanism 13 to bring the chuck table 20 and the cutting tool 33 closer to each other.

[0112] In addition, when the first cutting unit 18 is lowered, the control unit 7 uses the vibration sensor 50 and the vibration detection unit 72 to obtain the vibration value of the spindle 30, and determines whether the vibration value is greater than a preset value (predetermined value). Furthermore, when the control unit 7 determines that the vibration value is less than the predetermined value, it determines that the cutting tool 33 is not in contact with the wafer 100, and controls the flow rate adjustment valve 36 to maintain the air supply flow rate to the air bearing 40 at the second flow rate.

[0113] On the other hand, when the control unit 7 determines that the vibration value is greater than the predetermined value, it determines that the cutting tool 33 is in contact with the wafer 100 and controls the flow rate adjustment valve 36 to change the air supply flow rate to the air bearing 40 to a first flow rate greater than the second flow rate.

[0114] After the first cutting unit 18 has been lowered, the control unit 7 moves the chuck table 20 in the X-axis direction using the X-axis direction moving mechanism 11 to cut the wafer 100 along the planned dividing line 102 .

[0115] In this structure, the cutting device 1 has a vibration sensor 50 for detecting the vibration of the spindle 30. Furthermore, the control unit 7 controls the flow rate regulating valve 36 to make the air supply flow rate a relatively small second flow rate until the vibration value detected by the vibration sensor 50 becomes equal to or greater than a predetermined value. Thus, when the cutting process is not performed, the spindle 30 can be prevented from seizing, and the consumption of air for forming the air bearing 40 can be suppressed.

[0116] When the vibration value of the spindle 30 is equal to or greater than a predetermined value, the control unit 7 determines that the cutting tool 33 is in contact with the wafer 100 and changes the air supply flow rate to a first flow rate greater than the second flow rate.

[0117] In addition, when the air supply flow rate is controlled by using the rotation load detection unit 71 or the vibration sensor 50, in the above description, the first Z-axis direction moving mechanism 16 moves the air supply flow rate to the first Z-axis direction moving mechanism 16. Figure 6 The first cutting unit 18 at the second initial position shown in the figure is lowered, so that the chuck table 20 and the cutting tool 33 are close to each other. In this regard, even when the rotation load detection unit 71 or the vibration sensor 50 is used, the X-axis direction moving mechanism 11 can be used to move the chuck table 20 and the cutting tool 33 to move closer to each other. Figure 4The chuck table 20 in the state shown is moved in the X-axis direction, so that the chuck table 20 and the cutting tool 33 are close to each other. In this case as well, the control unit 7 controls the flow rate adjustment valve 36 to make the air supply flow rate become the second flow rate which is relatively small, until the rotation load (load current value or load value) or the vibration value becomes a predetermined value or more, and on the other hand, when these values ​​become a predetermined value or more, it is determined that the cutting tool 33 is in contact with the wafer 100, and the air supply flow rate is changed to the first flow rate which is larger than the second flow rate.

[0118] In addition, the control unit 7 may also use the rotation load detection unit 71, the vibration detection unit 72 (vibration sensor 50), the Z-axis distance detection unit 73 or the X-axis distance detection unit 74 to detect whether the cutting tool 33 is separated from the wafer 100 when the chuck table 20 and the first cutting unit 18 are moved in a relatively separated direction by the moving unit (X-axis direction moving mechanism 11 and the first Z-axis direction moving mechanism 16) during or after the cutting process of the wafer 100. Furthermore, the control unit 7 may control the flow regulating valve 36 to change the air supply flow rate to a second flow rate that is less than the first flow rate when it is determined that the cutting tool 33 is separated from the wafer 100.

[0119] Furthermore, when the first tool detection unit 61 or the second tool detection unit 62 detects the outer diameter of the cutting tool 33 , the control unit 7 may control the flow rate regulating valve 36 to implement the second flow rate.

[0120] In addition, in the present embodiment, a cutting device 1 is shown as an example of a processing device. In this regard, the processing device of the present embodiment can be any processing device that processes a workpiece, and the processing device has: a processing unit having a processing tool mounted on the front end of a spindle supported by an air bearing so as to be rotatable; a chuck table that holds the workpiece; and a moving unit that moves the processing unit and the chuck table relatively close to and away from each other. For example, the processing device of the present embodiment may also be a grinding device having a grinding tool as a processing tool or a polishing device having a polishing pad as a processing tool.

Claims

1. A processing device for processing a workpiece, the processing device comprising: a processing unit having a processing tool mounted on the front end of a spindle supported by an air bearing so as to be rotatable; a chuck table for holding the workpiece; and a moving unit for making the processing unit and the chuck table relatively close to and away from each other, wherein: The processing device has: a flow regulating valve for regulating the flow rate of air provided to form the air bearing; and A control unit moves the chuck table and the machining unit in a direction relatively close to each other through the moving unit, and controls the flow regulating valve to make the air supply flow rate become a second flow rate less than the first flow rate until the machining tool contacts the workpiece, the air supply flow rate is the flow rate of air provided to form the air bearing, and the first flow rate is the flow rate of air when the workpiece is processed.

2. The processing device according to claim 1, wherein: The control unit brings the chuck table and the processing tool closer to each other and controls the flow rate regulating valve to make the air supply flow rate become the second flow rate until the distance between the chuck table and the processing tool becomes a preset distance.

3. The processing device according to claim 1, wherein: The processing device includes a rotation load detection unit for detecting the rotation load of the spindle. The control unit controls the flow rate regulating valve so that the air supply flow rate becomes the second flow rate until the value of the rotation load detected by the rotation load detection unit becomes equal to or greater than a preset value.

4. The processing device according to claim 1, wherein: The processing device has a vibration sensor for detecting the vibration of the spindle. The control unit controls the flow rate regulating valve to make the air supply flow rate the second flow rate until the value of the vibration detected by the vibration sensor becomes equal to or greater than a preset value.

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