Processing equipment

Abstract

To provide a processing device that can detect a position of an origin point in a Z-axis direction of a cutting blade, without being influenced by raw materials constituting a cutting edge of the cutting blade and raw materials constituting frame bodies of a chuck table and of a sub chuck table.SOLUTION: Cutting means 12 is moved down toward an upper surface of a chuck table 24 positioned just below the cutting means 12 by activating Z-axis feeding means 60; change of torque of the Z-axis feeding means 60 caused by contact of a tip of a cutting edge 123 of the cutting blade with an upper surface of the chuck table 24 is detected; the moving down of the cutting means 12 is stopped and a Z-axis coordinate P3 at the time when the change is detected is memorized; and a position of an origin point of the cutting edge 123 of the cutting blade is detected.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a processing device capable of detecting the origin position of a cutting edge of a cutting blade. [Background technology]

[0002] Wafers with multiple devices such as ICs and LSIs formed on their surface, partitioned by planned division lines, are then separated into individual device chips by a dicing machine and used in electrical equipment such as mobile phones and personal computers.

[0003] The dicing device is configured to include a chuck table that holds a wafer, cutting means having a rotatable cutting blade with a cutting edge on its outer periphery that cuts the wafer held on the chuck table, X-axis feed means that feeds the chuck table and the cutting means relatively in the X-axis direction for processing, Y-axis feed means that feeds the chuck table and the cutting means relatively in the Y-axis direction that is perpendicular to the X-axis direction, Z-axis feed means that feeds the chuck table and the cutting means relatively in the Z-axis direction that is perpendicular to the X-axis and Y-axis directions for cutting, and control means, and can divide the wafer into individual device chips with high precision.

[0004] Furthermore, since the tip of the cutting blade wears and its diameter gradually decreases during cutting, in order to maintain the cutting blade's cutting precision, it has been proposed to gradually lower the cutting means periodically or at any timing, detect contact between the cutting blade and the chuck table by monitoring electrical continuity between them, set the contact position as the origin position in the Z-axis direction of the cutting blade, and use this origin position to precisely control the cutting feed amount when cutting (see, for example, Patent Document 1). Note that detection of the origin position is also necessary when the cutting blade is replaced with a new one. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-082709 Summary of the Invention [Problem to be solved by the invention]

[0006] The technique described in Patent Document 1 allows for electrical conduction to determine the origin of the cutting blade in the Z-axis direction only when the cutting edge of the cutting blade is made of a metal, such as nickel-plated diamond abrasive grains, and the frame of the chuck table is made of a metal, such as stainless steel, i.e., both are made of conductive materials. However, if the cutting edge of the cutting blade is made of a non-conductive material, such as a resin-bonded or vitrified-bonded diamond abrasive grains, or if the frame of the chuck table is made of a non-conductive material, such as ceramics, the above method cannot be used to determine the origin of the cutting blade in the Z-axis direction. Furthermore, if a sub-chuck table is provided adjacent to the chuck table to hold a dressing board for sharpening the cutting edge of the cutting blade, the origin of the cutting blade in the Z-axis direction relative to the sub-chuck table must be determined, which poses a similar problem.

[0007] The present invention has been made in consideration of the above facts, and its main technical objective is to provide a processing device that can detect the origin position of the cutting blade in the Z-axis direction without being affected by the material that makes up the cutting edge of the cutting blade or the material that makes up the frame of the chuck table or sub-chuck table. [Means for solving the problem]

[0008] In order to solve the above-mentioned main technical problem, according to the present invention, there is provided a cutting means including a chuck table for holding a workpiece, a cutting blade rotatably provided with a cutting blade having a cutting edge on the outer periphery for cutting the workpiece held on the chuck table, an X-axis feed means for relatively feeding the chuck table and the cutting means in an X-axis direction, a Y-axis feed means for relatively indexing and feeding the chuck table and the cutting means in a Y-axis direction perpendicular to the X-axis direction, and a Z-axis feed means for relatively indexing and feeding the chuck table and the cutting means in a Z-axis direction perpendicular to the X-axis and Y-axis directions. A processing device is provided that includes a Z-axis feed means that feeds cutting in the axial direction and a control means, wherein the control means operates the Z-axis feed means to lower the cutting means toward the upper surface of the chuck table positioned directly below the cutting means, detects a change in torque of the Z-axis feed means caused by contact between the tip of the cutting edge of the cutting blade and the upper surface of the chuck table, stops the descent of the cutting means, and stores the Z-axis coordinate at the time the change is detected, setting it as the origin position of the cutting edge of the cutting blade.

[0009] According to the present invention, a chuck table for holding a workpiece and a For suction holding of a dressing board for sharpening to eliminate clogging of the cutting edge of a cutting blade a control means for detecting a torque change in the Z-axis feed means caused by contact between the tip of the cutting edge of the cutting blade and the upper surface of the sub-chuck table; ... [Effects of the Invention]

[0010] The processing apparatus of the present invention is a processing apparatus comprising: a chuck table for holding a workpiece; cutting means rotatably provided with a cutting blade having a cutting edge on its outer periphery for cutting the workpiece held on the chuck table; X-axis feed means for relatively feeding the chuck table and the cutting means in an X-axis direction for processing; Y-axis feed means for relatively indexing and feeding the chuck table and the cutting means in a Y-axis direction perpendicular to the X-axis direction; Z-axis feed means for relatively cutting the chuck table and the cutting means in a Z-axis direction perpendicular to the X-axis and Y-axis directions; and control means, wherein the control means operates the Z-axis feed means to feed a cutting force toward an upper surface of the chuck table positioned directly below the cutting means. The cutting means is lowered, the change in torque of the Z-axis feed means caused by contact between the tip of the cutting blade and the top surface of the chuck table is detected, the lowering of the cutting means is stopped, and the Z-axis coordinate at the time the change is detected is stored and used as the origin position of the cutting blade.This makes it possible to determine the origin position of the cutting blade in the Z-axis direction without being affected by the material that makes up the cutting blade or the material that makes up the frame of the chuck table.Furthermore, since the origin position is not detected by electrical conduction, it is possible to determine the origin position of the cutting blade in the Z-axis direction at any position on the chuck table, not just the frame of the chuck table.

[0011] Furthermore, the processing apparatus of the present invention includes a chuck table for holding the workpiece, and a For suction holding of a dressing board for sharpening to eliminate clogging of the cutting edge of a cutting bladea sub-chuck table; cutting means rotatably provided with a cutting blade having a cutting edge on its outer periphery for cutting a workpiece held on the chuck table; X-axis feed means for relatively feeding the chuck table and the cutting means in an X-axis direction for processing; Y-axis feed means for relatively indexing and feeding the chuck table and the cutting means in a Y-axis direction perpendicular to the X-axis direction; Z-axis feed means for relatively cutting the chuck table and the cutting means in a Z-axis direction perpendicular to the X-axis and Y-axis directions; and control means, wherein the control means operates the Z-axis feed means to feed the chuck table and the cutting means toward an upper surface of the sub-chuck table positioned directly below the cutting means. The cutting means is lowered, and the change in torque of the Z-axis feed means caused by contact between the tip of the cutting blade and the upper surface of the sub-chuck table is detected, the lowering of the cutting means is stopped, and the Z-axis coordinate at the time the change is detected is stored and used as the origin position of the cutting blade.This makes it possible to determine the origin position of the cutting blade in the Z-axis direction without being affected by the material constituting the cutting blade or the material constituting the sub-chuck table.Furthermore, since the origin position is not detected by electrical conduction, it is possible to determine the origin position of the cutting blade in the Z-axis direction regardless of the position on the sub-chuck table. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 2 is an overall perspective view of the dicing device. [Figure 2] 2 is a perspective view showing an outline of the configuration accommodated inside the housing of the dicing device shown in FIG. 1. FIG. [Figure 3] 3 is a flowchart of control executed by a control unit of the dicing apparatus shown in FIG. 2. [Figure 4] 4 is a side view showing an embodiment when detecting the origin position by the control shown in FIG. 3. FIG. [Figure 5] 5 is a conceptual diagram showing a change in torque of the Z-axis feed means when the origin position is detected by the embodiment shown in FIG. 4. DETAILED DESCRIPTION OF THE INVENTION

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a processing apparatus configured based on the present invention will be described in detail with reference to the accompanying drawings.

[0014] 1 shows an overall perspective view of a dicing apparatus 1, which is an embodiment of the processing apparatus of the present invention. As shown in the figure, the workpiece processed by the dicing apparatus 1 is a wafer W, which is formed by dividing a plurality of devices into sections defined by planned division lines, and is supported on an annular frame F via adhesive tape T.

[0015] 1, the dicing apparatus 1 includes a substantially rectangular parallelepiped housing 1A, a cassette 4A placed on a cassette table 4 of the housing 1A, a carry-in / out means 3 for carrying out the wafer W supported on a frame F from the cassette 4A to a temporary storage table 5, a transport means 6 having a swivel arm for transporting the wafer W carried out to the temporary storage table 5 to a chuck table 24 of a holding means 20, a cutting means 12 provided as a processing means for cutting the wafer W held on the chuck table 24, and a display means 14 with a touch panel function for displaying processing conditions and the like and for an operator to set the processing conditions, etc. Further, an alignment means 11 is provided for capturing an image of the wafer W held on the chuck table 24 and detecting the area to be cut by the cutting means 12.

[0016] 2 in addition to Fig. 1, the schematic configuration of the interior contained within the housing 1A of the dicing device 1 will be described in more detail. A holding means 20 and a spindle support mechanism 8 that supports a spindle unit 9 equipped with a cutting means 12 at its tip are arranged on the stationary base 2, as well as an X-axis feed means 30 that feeds the chuck table 24 and the cutting means 12 relatively in the X-axis direction for processing, a Y-axis feed means 50 that indexes and feeds the chuck table 24 and the cutting means 12 relatively in the Y-axis direction perpendicular to the X-axis direction, and a Z-axis feed means 60 that feeds the chuck table 24 and the cutting means 12 relatively in the X-axis direction and in the Z-axis direction perpendicular to the Y-axis direction.

[0017] The holding means 20 includes a rectangular X-axis direction movable base 21 movably supported on a pair of guide rails 2a, 2a arranged parallel to the X-axis direction on the stationary base 2, a cylindrical support member 22 arranged on the X-axis direction movable base 21, a rectangular cover plate 23 covering the upper periphery of the cylindrical support member 22, a chuck table 24 arranged on the cylindrical support member 22, a suction chuck 25 made of a breathable material that forms the upper surface of the chuck table 24, a clamp mechanism 26 arranged between the cylindrical support member 22 and the chuck table 24 and gripping the frame F when the wafer W is supported on the chuck table 24, and a sub-chuck table 27 arranged on the cover plate 23 near the chuck table 24. The sub-chuck table 27 is a table for suction-holding a dress board (not shown) used for sharpening the cutting edge 123 of the cutting blade of the cutting means 12 to prevent clogging. A pair of guide grooves 21a, 21a that slidably abut on the guide rails 2a, 2a are formed on the underside of the X-direction movable base 21, and a sliding portion is formed by the guide rails 2a, 2a and the guide grooves 21a, 21a. Suction means (not shown) are connected to the chuck table 24 and the sub-chuck table 27, and by operating the suction means, negative pressure can be generated on the upper surfaces of the chuck table 24 and the sub-chuck table 27.

[0018] X-axis feed means 30 includes a drive source 31 and a ball screw 32 that converts the rotation of drive source 31 into linear motion and transmits it to a female screw portion (not shown) of X-axis movement base 21. By driving ball screw 32 in forward and reverse directions using drive source 31, chuck table 24 is moved in the X-axis direction together with X-axis movement base 21 along guide rails 2a, 2a. Drive source 31 is composed of an X-axis motor whose rotation speed can be precisely controlled.

[0019] The spindle support mechanism 8 includes a Y-axis direction movable base 40 that supports the spindle unit 9, and the Y-axis feed means 50 includes a drive source 51 configured from a Y-axis motor similar to the drive source 31 described above, in order to move the Y-axis direction movable base 40 along a pair of guide rails 2c, 2c arranged parallel to the Y-axis on the stationary base 2, and a ball screw 52 that converts the rotation of the drive source 51 into linear motion and transmits it to a female screw portion (not shown) formed on the underside of the support portion 42 of the Y-axis direction movable base 40. By driving the ball screw 52 in forward and reverse directions by the drive source 51, the Y-axis direction movable base 40 is moved in the Y-axis direction along the guide rails 2c, 2c.

[0020] The spindle unit 9 is mounted on a mounting wall 43 of the Y-axis direction movable base 40, and includes a Z-axis direction movable base 121, a spindle housing 122 supported by the Z-axis direction movable base 121, and cutting means 12 disposed at the tip of the spindle housing 122 and rotatably supporting a cutting edge 123 of a cutting blade. The Z-axis direction movable base 121 is supported on the mounting wall 43 so as to be movable along a pair of guide rails 44, 44 disposed parallel to the Z-axis direction (cutting feed direction) indicated by arrow Z1. The Y-axis direction movable base 40 is provided with a pair of guide grooves 121a (only one of which is shown in the figure) that slidably abut on the guide rails 44, 44. The Y-axis direction moving base 40 is equipped with a driving source 61 constituted by, for example, a Z-axis motor similar to the above-described driving sources 31 and 51, and a Z-axis feed means 60 including a ball screw that converts the rotation of the driving source 61 into linear motion and transmits it to a female screw portion (described later) formed in the Z-axis direction moving base 121, and feeds the chuck table 24 and the cutting means 12 relatively in the Z-axis direction, which is perpendicular to the X-axis and Y-axis directions. By rotating the driving source 61 forward, the cutting means 12 descends, and by rotating the driving source 61 in the reverse direction, the cutting means 12 ascends.

[0021] The dicing apparatus 1 is provided with a control means 100. The control means 100 is configured by a computer and includes a central processing unit (CPU) that performs calculations according to a control program, a read-only memory (ROM) that stores the control program, etc., a readable and writable random access memory (RAM) that temporarily stores detected values, calculation results, etc., an input interface, and an output interface (details are not shown in the drawings). Based on drive signals issued by the control means 100, the above-mentioned drive sources 31, 51, 61, and other operating parts are controlled.

[0022] The Z-axis direction moving base 121 is provided with a Z-axis coordinate detecting means 124 that detects the Z-axis coordinate of the center position of the cutting edge 123 of the cutting blade of the cutting means 12. A Z-axis scale 125 extending in the Z-axis direction is provided on the side of the mounting wall 43 facing the Z-axis coordinate detecting means 124. The memory of the Z-axis scale 125 is read by the detector 124a of the Z-axis detecting means 124, thereby detecting the Z-axis coordinate of the center of the cutting edge 123 of the cutting blade of the cutting means 12. The Z-axis coordinate read by the Z-axis detecting means 124 is sent to the control means 100 and stored in an appropriate memory area. The drive source 61 is controlled based on the Z-axis coordinate detected by the Z-axis detecting means 124, and the Z-axis position of the cutting edge 123 of the cutting blade of the cutting means 12 is precisely controlled. Although not shown in the figure, the dicing device 1 is also provided with a position detection means for detecting the X-axis position of the X-axis moving base 21 and the Y-axis position of the Y-axis moving base 40, and the position of the cutting edge 123 of the cutting blade of the cutting means 12 can be precisely controlled to the desired X-axis coordinate, Y-axis coordinate, and Z-axis coordinate positions.

[0023] The dicing device 1 has roughly the configuration as described above, and the control means 100 operates the Z-axis feed means 60 to lower the cutting means 12 toward the upper surface of the chuck table 24 positioned directly below the cutting means 12, detects a change in torque of the Z-axis feed means 60 caused by contact between the tip of the cutting edge 123 of the cutting blade and the upper surface of the chuck table 24, stops the lowering of the cutting means 12, and stores the Z-axis coordinate when the change is detected, setting it as the origin position of the cutting edge of the cutting blade. The origin position detection function will be described in more detail with reference to Figures 3 to 5.

[0024] The origin position detection function is performed, for example, after replacing the cutting blade of the cutting means 12, periodically after the cutting blade is replaced, or at any timing. When performing the origin position detection function, first, the chuck table 24 is positioned directly below the cutting edge 123 of the cutting blade of the cutting means 12. After that, an origin position detection program configured based on the flowchart shown in FIG. 3 is executed. At this time, the Z-axis direction moving base 121 of the cutting means 12 is positioned by the Z-axis feed means 60 at the position indicated by the upper two-dot chain line in FIG. 4, and the Z-axis coordinate P1 of the center O" of the cutting edge 123 of the cutting blade is detected by the detection unit 124a of the Z-axis direction detection means 124. At this time, the rough tip position B1 of the cutting edge 123 of the cutting blade is calculated as an estimated value by referring to the value of the Z-axis coordinate P1 and the value of the designed diameter when the cutting edge 123 of the cutting blade is new. Note that the actual tip position B1 changes depending on the wear state of the cutting edge 123 of the cutting blade, and therefore is an estimated position in this state. As shown in FIG. 4, the Z-axis feed means 60 includes a drive source 61 and a ball screw 62. By operating the Z-axis motor of the drive source 61 to rotate the ball screw 62, the rotation of the ball screw 62 is transmitted to the female thread portion 121b formed in the Z-axis direction moving base 121 and converted into linear motion, thereby moving the cutting edge 123 of the cutting blade in the Z-axis direction.

[0025] 3, first, by executing step S1, the Z-axis motor constituting the drive source 61 of the Z-axis feed means 60 is rotated in the forward direction, thereby lowering the cutting means 12 together with the Z-axis moving base 121. At this time, the Z-axis motor can be operated at a constant speed, but it is preferable to lower the cutting blade 12 at a relatively fast first speed (e.g., 1.0 mm / sec) to a position where the Z-axis coordinate of the center O' of the cutting blade detected by the detection unit 124a of the Z-axis direction detection means 124, shown by the dashed-dotted line in FIG. 4, becomes P2, i.e., to a position where the cutting edge 123 of the cutting blade approaches the upper surface of the suction chuck 25 of the chuck table 24 and the tip position B2 is 0.5 to 1.0 mm from the upper surface, and then to a second speed (e.g., 0.01 mm / sec) slower than the first speed. The actual position of the tip position B2 varies depending on the wear state of the cutting blade 123, but even if the cutting edge 123 of the cutting blade is new, the tip position B2 of the cutting edge 123 of the cutting blade is controlled so as not to collide with the upper surface of the suction chuck 25. For convenience of explanation, the following description will be given assuming that the cutting edge 123 of the cutting blade is lowered at a constant speed.

[0026] As described above, FIG. 5 shows a conceptual diagram of the change in drive torque when the cutting means 12 is lowered. In FIG. 5, the horizontal axis represents elapsed time (t), and the vertical axis represents the drive current (A) corresponding to the Z-axis motor torque constituting the drive source 61. As described above, by operating the Z-axis motor at time T1, the drive current M1 for lowering the cutting means 12 increases. While the cutting means 12 is lowering together with the Z-axis moving base 121, the drive current M1 remains at Ia. As can be seen from the flowchart shown in FIG. 3, in step S2, it is determined whether there has been a change in the Z-axis motor torque while the cutting means 12 is lowering. More specifically, this determination is made, for example, by determining whether the value of the drive current M1 exceeds the threshold value L shown in FIG. 5. If it is determined in step S2 that there has been no change in the Z-axis motor torque (L > Ia) (no), the process returns to step S1, the Z-axis motor continues to rotate forward, and the determination routine described in step S2 is repeated. Then, the cutting edge 123 of the cutting blade reaches the position shown by the solid line in Figure 4, and the tip position B3 of the cutting edge 123 of the cutting blade comes into contact with the upper surface of the vacuum chuck 25 of the chuck table 24 at the position shown by the solid line. As a result, the Z-axis motor torque, i.e., the drive current M1 shown in Figure 5, rises sharply from point R1 to reach Ib and exceeds the threshold value L at time T2. As a result, in step S2, it is determined that there has been a change in the drive torque of the Z-axis motor (yes), and the process proceeds to step S3, where the supply of the drive current M1 is stopped and the operation of the Z-axis motor is stopped. Next, the process proceeds to step S4, where the value of the Z-axis scale 125 (Z-axis coordinate P3) is read when the tip position B3 of the cutting edge 123 of the cutting blade comes into contact with the upper surface of the vacuum chuck 25 of the chuck table 24 and the Z-axis motor stops. The value of Z-axis coordinate P3 is then stored in control means 100 as the Z-axis coordinate at which a change in torque of Z-axis feed means 60 is detected, and is also stored as the origin position where cutting edge 123 of the cutting blade contacts the upper surface of suction chuck 25 of chuck table 24. Once the origin position has been stored, the process proceeds to step S5, where, as shown in Fig. 5, a drive current M2 is supplied to the Z-axis motor to rotate it in the reverse direction, thereby lifting the cutting means 12 and returning the cutting blade to the initial position indicated by the two-dot chain line in Fig. 4, and the origin position detection program is terminated.By appropriately executing such an origin position detection program when the cutting edge 123 of the cutting blade is replaced with a new one or when a certain amount of wear is expected, and detecting and storing the above-mentioned origin position (Z-axis coordinate P3), cutting processing can always be performed with an accurate cutting depth.

[0027] According to the above-described embodiment, it is possible to determine the origin position of the cutting blade in the Z-axis direction without being affected by the material constituting the cutting edge 123 of the cutting blade or the material constituting the frame of the chuck table 24.Furthermore, since the detection is not based on electrical conduction, it is possible to determine the origin position of the cutting blade in the Z-axis direction at any position on the chuck table 24, not just the frame of the chuck table 24.

[0028] In the above embodiment, the change in torque of the Z-axis feed means 60 is determined based on the drive current of the Z-axis motor that constitutes the drive source 61 of the Z-axis feed means 60, but the present invention is not limited to this. For example, a G (acceleration) sensor may be placed on the Z-axis moving base 121 to detect the change in acceleration when the cutting edge 123 of the cutting blade comes into contact with the upper surface of the suction chuck 25 of the chuck table 24, thereby determining that there has been a change in the torque of the Z-axis feed means 60, stopping the operation of the Z-axis motor, and storing the value of the above-mentioned Z-axis coordinate P3 in the control means 100 as the origin position (Z-axis coordinate) where the change in torque of the Z-axis feed means 60 was detected.

[0029] In the above embodiment, the change in torque of the Z-axis feed means 60 caused by contact between the tip of the cutting blade 123 and the upper surface of the chuck table 24 is detected, the descent of the cutting means 12 is stopped, and the Z-axis coordinate P3 at the time of detecting the change is stored and stored as the origin position of the cutting blade 123. However, the present invention is not necessarily limited to this. It is also possible to position the cutting means 12 above the sub-chuck table 27 disposed near the chuck table 24, operate the Z-axis feed means 60 to lower the cutting means 12 toward the upper surface of the sub-chuck table 27 positioned directly below the cutting means 12, detect the change in torque of the Z-axis feed means 60 caused by contact between the tip of the cutting blade 123 and the upper surface of the sub-chuck table 27, stop the descent of the cutting means 12, and store the Z-axis coordinate at the time of detecting the change as the origin position of the cutting blade 123.

[0030] If the height of the upper surface of the suction chuck 25 of the chuck table 24 is the same as the height of the upper surface of the sub-chuck table 27, either the chuck table 24 or the sub-chuck table 27 can be used to detect the origin position of the cutting edge 123 of the cutting blade, and based on the origin position, the workpiece held on the chuck table 24 can be machined or the cutting blade can be sharpened by feeding the workpiece into the dress board held on the sub-chuck table 27. Even if the heights of the upper surfaces of the suction chuck 25 of the chuck table 24 and the sub-chuck table 27 are different, if the difference in height is known in advance, the origin position of the cutting edge 123 of the cutting blade can be detected and stored using either the chuck table 24 or the sub-chuck table 27, as described above, and used for cutting or sharpening the cutting edge 123 of the cutting blade. [Explanation of symbols]

[0031] 1: Dicing equipment 1A: Housing 2:Stationary base 2a: Guide rail 2c: Guide rail 3: Carrying in / out means 4: Cassette table 4A: Cassette 5: Temporary table 6: Means of transport 8: Spindle support mechanism 9: Spindle unit 11: Alignment means 12:Cutting means 121: Z-axis movement base 121a: Guide groove 122: Spindle housing 123:Cutting blade 124: Z-axis direction detection means 124a: detection unit 125: Z-axis scale 14:Display means 20: Holding means 21:X-axis direction movement base 22: Cylinder support member 23: Cover plate 24: Chuck table 25: Vacuum chuck 26: Clamping mechanism 27: Sub-chuck table 30: X-axis feed means 31: Power source 32: Ball screw 40: Y-axis movement base 42: Support part 43: Mounting wall 44: Guide rail 50: Y-axis feed means 51: Power source 52: Ball screw 60: Z-axis feed means 61: Power source 62: Ball screw 100: Control means

Claims

1. a cutting means having a rotatable cutting blade with a cutting edge on its outer periphery for cutting the workpiece held on the chuck table; an X-axis feed means for relatively feeding the chuck table and the cutting means in the X-axis direction for processing; a Y-axis feed means for relatively indexing the chuck table and the cutting means in the Y-axis direction perpendicular to the X-axis direction; a Z-axis feed means for relatively cutting the chuck table and the cutting means in the Z-axis direction perpendicular to the X-axis direction and the Y-axis direction; and a control means, The control means operates the Z-axis feed means to lower the cutting means toward the upper surface of the chuck table positioned directly below the cutting means, detects a change in torque of the Z-axis feed means caused by contact between the tip of the cutting edge of the cutting blade and the upper surface of the chuck table, stops the descent of the cutting means, and stores the Z-axis coordinate at the time the change is detected, setting it as the origin position of the cutting edge of the cutting blade.

2. a sub-chuck table for suction-holding a dressing board for sharpening a cutting blade disposed adjacent to the chuck table to prevent clogging of the cutting edge of the cutting blade; cutting means having a rotatable cutting blade with a cutting edge on its outer periphery for cutting the workpiece held on the chuck table; X-axis feed means for feeding the chuck table and the cutting means relatively to each other in the X-axis direction for processing; Y-axis feed means for indexing and feeding the chuck table and the cutting means relatively to each other in the Y-axis direction perpendicular to the X-axis direction; Z-axis feed means for feeding the chuck table and the cutting means relatively to each other in the X-axis direction and the Z-axis direction perpendicular to the Y-axis direction; and control means, The control means operates the Z-axis feed means to lower the cutting means toward the upper surface of the sub-chuck table positioned directly below the cutting means, detects a change in torque of the Z-axis feed means caused by contact between the tip of the cutting edge of the cutting blade and the upper surface of the sub-chuck table, stops the descent of the cutting means, and stores the Z-axis coordinate at the time the change is detected, setting it as the origin position of the cutting edge of the cutting blade.

Images