Management method for holding table and manufacturing method for chip

Abstract

To provide a management method for a holding table, capable of properly determining the timing of exchanging the holding table.SOLUTION: A management method for a holding table to be used for managing a holding table included in a cutting device includes: a first calculation step of taking an image of a region including a clearance groove of the holding table by a camera and calculating a width of the clearance groove from the obtained image; after the first calculation step, a second calculation step of taking an image of a region including the clearance groove of the holding table by a camera and calculating the width of the clearance groove by the obtained image; and after the second calculation step, a determination step of determining whether or not a difference between the width of the clearance groove calculated in the first calculation step and the width of the clearance groove calculated in the second calculation step is within an allowable range regulated by a preset threshold value.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a method for managing a holding table and a method for manufacturing a chip. [Background technology]

[0002] Electrical equipment such as mobile phones and personal computers utilize packaged devices manufactured using packaging technologies such as CSP (Chip Size Package) and QFN (Quad Flat Non-leaded package). Packaged devices are obtained, for example, by encapsulating a chip or wafer on which devices such as integrated circuits are mounted with resin to form a package substrate, and then dividing the package substrate into individual device units.

[0003] When dividing the package substrate into package devices, for example, a cutting device is used that includes a holding table for holding the package substrate and a spindle to which a cutting blade is attached. The cutting blade rotated by the spindle is cut into the package substrate held by the holding table along the planned division lines, thereby cutting the package substrate and dividing it into a plurality of package devices.

[0004] Here, the upper surface of the holding table with which the package substrate comes into contact is made of resin such as rubber. In addition, a groove (relief groove) is formed in the holding table to prevent interference between the cutting blade that cuts into the planned dividing line of the package substrate and the holding table. Specifically, the upper end of the relief groove of sufficient depth is opened at a position corresponding to the planned dividing line of the package substrate.

[0005] Suction holes are provided in each region of the upper surface of the holding table separated by the clearance grooves so that package devices separated from the package substrate can be sucked in. Each suction hole is connected to a suction source via a flow path (suction path) or the like provided in the holding table. With the package substrate placed on the upper surface of the holding table, negative pressure from the suction source is applied to the suction holes, whereby the package substrate before cutting and the package device after cutting are sucked in and held by the holding table (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2011-114145 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, the clearance groove of the holding table may wear out due to contact with the cutting blade, etc., and the width of the clearance groove may increase. For example, if the cutting blade meanders while cutting into the planned division line, the side of the cutting blade comes into contact with the side wall of the clearance groove, causing the clearance groove to wear out. In addition, the clearance groove may also wear out due to cutting chips generated by cutting being caught between the side of the cutting blade and the side wall of the clearance groove.

[0008] When the width of the clearance groove of the holding table is increased in this way, the clearance groove and the suction hole may become connected. In particular, when the size of the package device is small, the interval between adjacent clearance grooves becomes narrow, and the distance between the clearance groove and the suction hole also becomes small, and even slight wear can cause the clearance groove to become connected to the suction hole.

[0009] If the escape groove becomes connected to the suction hole, the negative pressure from the suction source leaks from the escape groove, and sufficient negative pressure cannot be applied to the suction hole. As a result, the holding table cannot suck and hold the package substrate. To prevent this problem from occurring, it is necessary to replace the holding table before the escape groove becomes connected to the suction hole.

[0010] On the other hand, because replacing the holding table is an operation that increases the time and cost required for manufacturing packaged devices, it is desirable to perform it only when necessary. In view of these circumstances, there has been a need to establish a method for appropriately determining whether or not the holding table needs to be replaced.

[0011] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a method for managing a holding table that can appropriately determine whether or not the holding table needs to be replaced. [Means for solving the problem]

[0012] A method for managing a holding table according to one aspect of the present invention is a method for managing a holding table provided in a cutting device, the cutting device including: a holding table for holding a workpiece having a planned division line set thereon; a spindle equipped with a cutting blade for cutting the workpiece held on the holding table; and a camera for imaging the workpiece held on the holding table from above, the cutting blade being attached to a position on the holding table corresponding to the planned division line so that the cutting blade does not interfere with the holding table when cutting the workpiece into the planned division line. a holding table having an escape groove for allowing escape of a part of the holding table, the holding table having an escape groove and a management method thereof including a first calculation step of capturing an image of an area of ​​the holding table including the escape groove with the camera and calculating a width of the escape groove from the obtained image, a second calculation step after the first calculation step of capturing an image of an area of ​​the holding table including the escape groove with the camera and calculating a width of the escape groove from the obtained image, and a determination step after the second calculation step of determining whether or not a difference between the width of the escape groove calculated in the first calculation step and the width of the escape groove calculated in the second calculation step is within an allowable range defined by a preset threshold value.

[0013] Preferably, the method further includes, after the determining step, a notifying step of notifying the user that the difference is not within the allowable range when the determining step determines that the difference is not within the allowable range.

[0014] According to another aspect of the present invention, there is provided a chip manufacturing method including the above-mentioned holding table management method, which further includes a chip manufacturing step, after the first calculation step and before the second calculation step, of cutting the workpiece held by the holding table along the planned dividing line by cutting the workpiece along the planned dividing line, thereby producing a plurality of chips. Effect of the Invention

[0015] A method for managing a holding table according to one aspect of the present invention includes a first calculation step of photographing an area of ​​the holding table including the escape groove with a camera and calculating a width of the escape groove from the obtained image, and a second calculation step of photographing, after the first calculation step, an area of ​​the holding table including the escape groove with a camera and calculating the width of the escape groove from the obtained image.

[0016] The method for managing a holding table according to an aspect of the present invention includes a determination step of determining whether or not a difference between the width of the clearance groove obtained in the first calculation step and the width of the clearance groove obtained in the second calculation step is within an allowable range defined by a preset threshold value. Therefore, according to the method for managing a holding table according to an aspect of the present invention, it is possible to appropriately determine whether or not the holding table needs to be replaced. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a perspective view of a cutting device. [Diagram 2] FIG. 2 is a top view of the workpiece. [Diagram 3] FIG. 3 is a bottom view of the workpiece. [Figure 4] FIG. 4 is a top view of the holding table. [Diagram 5] FIG. 5 is a cross-sectional view of the holding table, the table base, etc. [Figure 6] FIG. 6 is a block diagram showing the functional configuration of a controller realized by a program. [Figure 7] FIG. 7 is a flow diagram of a chip manufacturing method including a holding table management method according to an embodiment. [Figure 8] FIG. 8 is an image of the first region of the holding table captured by the camera in the first calculation step. [Figure 9] FIG. 9 is an image of the first region of the holding table captured by the camera in the second calculation step. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. First, a cutting device used in a holding table management method and a tip manufacturing method including the holding table management method according to the present embodiment will be described.

[0019] Fig. 1 is a perspective view of a cutting device 2. In Fig. 1, some of the elements constituting the cutting device 2 are expressed as functional blocks. In addition, the X-axis (first axis), Y-axis (second axis), and Z-axis (third axis) used in the following description are perpendicular to each other. As shown in Fig. 1, the cutting device 2 includes a base 4 that supports each structure.

[0020] A rectangular opening 4a that is long in the direction along the X-axis (X-axis direction, front-rear direction, processing feed direction) is formed on the upper surface of the base 4. In this opening 4a, there are provided an X-axis moving table (not shown), an X-axis moving mechanism (not shown) that moves the X-axis moving table in the X-axis direction, a table cover 6 that covers the top of the X-axis moving table, and a bellows-shaped dust-proof and drip-proof cover 8 that is connected to the table cover 6 and covers the X-axis moving mechanism.

[0021] The X-axis movement mechanism is equipped with a pair of X-axis guide rails (not shown) parallel to the X-axis direction, and an X-axis movement table is slidably attached to the X-axis guide rails. A nut portion (not shown) is provided on the underside of the X-axis movement table, and an X-axis ball screw (not shown) parallel to the X-axis guide rails is screwed into this nut portion.

[0022] An X-axis pulse motor (not shown) is connected to one end of the X-axis ball screw. By rotating the X-axis ball screw with the X-axis pulse motor, the X-axis moving table moves in the X-axis direction along the X-axis guide rail.

[0023] A holding unit 10 is disposed on the upper surface of the X-axis moving table such that at least a portion of the holding unit 10 is exposed from the table cover 6. The holding unit 10 has a table base 12. The table base 12 has a substantially rectangular first surface 12a and a substantially rectangular second surface (not shown) opposite the first surface 12a.

[0024] The table base 12 is connected to a rotary drive source (not shown) such as a motor, and rotates around a rotation axis that is approximately parallel to the direction along the Z axis (Z axis direction, vertical direction). A holding table 14 having a shape corresponding to the workpiece 11 is removably attached to a first surface 12a of the table base 12.

[0025] FIG. 2 is a top view of the workpiece 11 (viewed from a direction perpendicular to the first surface 11a), and FIG. 3 is a bottom view of the workpiece 11 (viewed from a direction perpendicular to the second surface 11b). As shown in FIG. 2 and FIG. 3, the workpiece 11 is typically a package substrate and includes a frame body 13. The frame body 13 is configured in a plate shape having a substantially rectangular first surface 13a and a second surface 13b opposite to the first surface 13a. The frame body 13 is configured of a metal such as 42 alloy (an alloy of iron and nickel) or copper. However, the shape and material of the frame body 13 are not limited to these. The first surface 11a of the workpiece 11 is configured by the first surface 13a of the frame body 13.

[0026] The first surface 13a of the frame 13 has a plurality of device regions 15 (three device regions 15 in this embodiment) and a peripheral surplus region 17 surrounding each device region 15. Each device region 15 is further divided into a plurality of regions (48 regions in this embodiment) by a plurality of linear division lines (streets) 19 that intersect with each other.

[0027] The width of the division lines 19 is, for example, 100 μm to 700 μm, typically 300 μm. In each region partitioned by the division lines 19, devices (device chips) (not shown) such as ICs (Integrated Circuits), LEDs (Light Emitting Diodes), and MEMS (Micro Electro Mechanical Systems) are disposed.

[0028] Further, a resin layer 21 that seals the multiple devices is provided on the second surface 13b side of the frame body 13. The resin layer 21 is formed to a predetermined thickness, and for example, slightly protrudes from the second surface 13b of the frame body 13. The second surface 13b corresponding to the back surface of each device region 15 is covered with this resin layer 21. The second surface 11b of the workpiece 11 is configured by a part of the second surface 13b of the frame body 13 and a surface 21a of the resin layer 21.

[0029] Fig. 4 is a top view of the holding table 14, and Fig. 5 is a cross-sectional view of the holding table 14 and the table base 12. As shown in Figs. 4 and 5, the holding table 14 is configured in a plate shape having a substantially rectangular first surface 14a and a substantially rectangular second surface 14b opposite to the first surface 14a. The first surface 14a serves as a holding surface for holding the workpiece 11.

[0030] The first surface 14a of the holding table 14 has a size equal to or larger than an area including three device regions so as to be able to hold at least the device region 15. Note that the holding table 14 in this embodiment is configured such that the first surface 14a and the second surface 14b are slightly larger than the first surface 11a and the second surface 11b of the workpiece 11.

[0031] The holding table 14 is made of, for example, a polymer material. Specific examples of the polymer material include rubber such as urethane rubber, nitrile rubber, ethylene rubber, butyl rubber, fluororubber, silicone rubber, isoprene rubber, butadiene rubber, acrylic rubber, and polysulfide rubber. However, there are no particular limitations on the shape, size, and material of the holding table 14.

[0032] An escape groove (cutting blade escape groove) 14c for allowing a cutting blade 38, which will be described later, to escape is formed on the first surface 14a side of the holding table 14. The upper end of the escape groove 14c opens to the first surface 14a. The escape groove 14c is provided at a position corresponding to a planned division line 19 of the workpiece 11 when the workpiece 11 is held on the holding table 14. The escape groove 14c divides the first surface 14a into a plurality of regions corresponding to chips after the workpiece 1 is divided.

[0033] In each region partitioned by the clearance grooves 14c, a suction hole 14d is formed which penetrates the holding table 14 and has one end opening in a substantially circular shape on the first surface 14a. As shown in Fig. 5, when the holding table 14 is placed on the first surface 12a of the table base 12, each suction hole 14d is connected to a first flow path 12b formed in a central portion on the first surface 12a side of the table base 12. The first flow path 12b is connected to a suction source 44 such as a vacuum pump via a valve 42a.

[0034] The space defined by the suction hole 14d has a substantially cylindrical shape. The width (diameter) of the suction hole 14d and the distance between the suction hole 14d and the clearance groove 14c are set in consideration of the size of the chip cut out from the workpiece 11 (the distance between the clearance grooves 14c) and the like. That is, the width (diameter) of the suction hole 14d and the distance between the suction hole 14d and the clearance groove 14c are set so that a sufficient contact area between the first surface 14a of the holding table 14 and the chip cut out from the workpiece 11 is ensured and a suction force sufficient to hold the chip can be applied to the chip.

[0035] For example, if the distance between the escape groove 14c and the suction hole 14d is 0.1 mm or more, the chip comes into contact with the first surface 14a of the holding table 14 over a sufficiently large area, so that the possibility of negative pressure leaking from the gap between the chip and the first surface 14a is low. On the other hand, if the distance between the escape groove 14c and the suction hole 14d exceeds 0.5 mm, the width (diameter) of the suction hole 14d becomes small, making it difficult to apply a sufficient suction force to the chip from the suction hole 14d.

[0036] Therefore, the distance between the clearance groove 14c and the suction hole 14d is preferably set to 0.3 mm or more and 1.0 mm or less, more preferably 0.4 mm or more and 0.6 mm or less. The width (diameter) of the suction hole 14d is determined according to the size of the chip (the distance between the clearance grooves 14c) and the distance between the clearance groove 14c and the suction hole 14d, and is, for example, 0.3 mm or more and 4.0 mm or less, typically 1.0 mm.

[0037] A second flow path 12c for mounting the holding table 14 on the table base 12 is formed on the outer periphery of the table base 12. This second flow path 12c is connected to a suction source 44 via a valve 42b. Therefore, by bringing the second surface 14b of the holding table 14 into contact with the first surface 12a of the table base 12 and opening the valve 42b, the holding table 14 is sucked to and held by the first surface 12a of the table base 12. In other words, the holding table 14 is fixed to the table base 12.

[0038] 1, a gate-shaped support structure 18 for supporting a cutting unit 16 that cuts (slices) the workpiece 11 is disposed across the opening 4a on the upper surface of the base 4. A cutting unit moving mechanism 20 for moving the cutting unit 16 in directions along the Y axis (Y axis direction, left / right direction, indexing feed direction) and in the Z axis direction is provided on the upper front surface of the support structure 18.

[0039] The cutting unit moving mechanism 20 is provided with a pair of Y-axis guide rails 22 that are arranged on the front surface of the support structure 18 and are parallel to the Y-axis direction. A Y-axis moving plate 24 that constitutes the cutting unit moving mechanism 20 is slidably attached to the Y-axis guide rails 22. A nut portion (not shown) is provided on the back surface side (rear surface side) of the Y-axis moving plate 24, and a Y-axis ball screw 26 that is parallel to the Y-axis guide rails 22 is screwed into this nut portion.

[0040] A Y-axis pulse motor (not shown) is connected to one end of the Y-axis ball screw 26. When the Y-axis ball screw 26 is rotated by the Y-axis pulse motor, the Y-axis moving plate 24 moves in the Y-axis direction along the Y-axis guide rail 22. A pair of Z-axis guide rails 28 parallel to the Z-axis direction are provided on the surface (front surface) of the Y-axis moving plate 24. A Z-axis moving plate 30 is slidably attached to the Z-axis guide rails 28.

[0041] A nut portion (not shown) is provided on the back surface side (rear surface side) of the Z-axis moving plate 30, and a Z-axis ball screw 32 parallel to the Z-axis guide rail 28 is screwed into this nut portion. A Z-axis pulse motor 34 is connected to one end of the Z-axis ball screw 32. When the Z-axis pulse motor 34 rotates the Z-axis ball screw 32, the Z-axis moving plate 30 moves in the Z-axis direction along the Z-axis guide rail 28.

[0042] A cutting unit 16 that cuts the workpiece 11 is provided below the Z-axis moving plate 30. A camera (imaging unit) 36 that images the upper surface side of the workpiece 11 is provided at a position adjacent to the cutting unit 16 along the X-axis direction. The camera 36 is positioned so as to be able to image an area including the escape groove 14c and the suction hole 14d of the first surface 14a of the holding table 14.

[0043] When the Y-axis moving plate 24 is moved in the Y-axis direction by the cutting unit moving mechanism 20, the cutting unit 16 and the camera 36 are indexed and fed. When the Z-axis moving plate 30 is moved in the Z-axis direction, the cutting unit 16 and the camera 36 are raised and lowered.

[0044] The cutting unit 16 includes an annular cutting blade 38 attached to one end of a spindle (not shown). A rotary drive source (not shown) such as a motor is connected to the other end of the spindle, and the cutting blade 38 rotates by a rotational force transmitted from the rotary drive source via the spindle. In addition, a cutting fluid supply nozzle 40 is disposed near the cutting blade 38 to supply cutting fluid such as pure water to the cutting blade 38 and the workpiece 11.

[0045] 1, a controller 46 is connected to various components of the cutting device 2 described above. The operation of each component is controlled by this controller 46. The controller 46 is configured by a computer including a processing device 48 such as a CPU (Central Processing Unit) and a storage device 50 consisting of a main storage device such as a DRAM (Dynamic Random Access Memory) and / or an auxiliary storage device such as a hard disk drive or a flash memory.

[0046] The functions of the controller 46 are realized by the processing device 48 operating in accordance with a program (software) stored in the storage device 50. However, the controller 46 may also be realized by hardware alone.

[0047] Fig. 6 is a block diagram showing a functional configuration of the controller 46 realized by a program. As shown in Fig. 6, the controller 46 includes an image acquisition unit 52, an image processing unit 54, a determination unit 56, a notification control unit 58, and a cutting control unit 60 as functional components. The image acquisition unit 52 causes the camera 36 to capture an image of the area including the clearance groove 14c of the holding table 14, and acquires an image showing the clearance groove 14c. The image processing unit 54 calculates the width of the clearance groove 14c from the image captured by the camera 36.

[0048] The determination unit 56 calculates the difference in width between the two clearance grooves 14c calculated from the two images acquired at two different times, and determines whether or not this difference is within an allowable range defined by a threshold value. The notification control unit 58 notifies the operator of the result of the determination by the determination unit 56. The cutting control unit 60 cuts the workpiece 11 held on the holding table 14 by the cutting unit 16.

[0049] The cutting device 2 also has one or more transport mechanisms (not shown) capable of transporting the above-mentioned workpiece 11 to the holding table 14 or the like. The transport mechanism is, for example, a robot arm. The workpiece 11 is carried by the transport mechanism onto the first surface 14a of the holding table 14 so that the first surface 11a side of the workpiece 11 is exposed.

[0050] In the cutting device 2 configured in this manner, the width of the clearance groove 14c provided in the first surface 14a of the holding table 14 is, for example, wider than the thickness of the cutting blade 38, and the depth of the clearance groove 14c is, for example, deeper than the maximum cutting depth of the cutting blade 38. Here, the maximum cutting depth of the cutting blade 38 refers to the maximum depth that the lower end of the cutting blade 38 reaches when processing the workpiece 11, with the first surface 14a of the holding table 14 as a reference.

[0051] Therefore, even if the cutting blade 38 is caused to cut deeply when cutting the workpiece 11 along the intended division line 19, there is no interference (contact) between the holding table 14 and the cutting blade 38. However, the depth of this clearance groove 14c is adjusted within a range not to reach the second surface 14b of the holding table 14. In other words, the clearance groove 14c does not penetrate the holding table 14 in the thickness direction.

[0052] Specifically, the width of the clearance groove 14c is set to be wider than the thickness of the cutting blade by, for example, 50 μm to 200 μm, taking into consideration the accuracy of alignment of the workpiece 11 with respect to the holding table 14 and the accuracy of the shape of the workpiece 11. Typically, the thickness of the cutting blade 38 is 20 μm to 500 μm, and the width of the clearance groove 14c is 70 μm to 700 μm. However, the thickness of the cutting blade and the width of the clearance groove 14c are not limited to these.

[0053] The depth of the clearance groove 14c is set, for example, to be deeper in the range of 20 μm to 1000 μm than the maximum cutting depth of the cutting blade 38. Typically, the maximum cutting depth of the cutting blade 38 is 300 μm to 600 μm, and the depth of the clearance groove 14c is 320 μm to 620 μm. Note that the maximum cutting depth of the cutting blade and the depth of the clearance groove 14c are not limited to these.

[0054] Next, a chip manufacturing method including a method for managing a holding table according to an embodiment will be described. FIG. 7 is a flow diagram of a method for manufacturing a chip including a method for managing a holding table according to an embodiment. As shown in FIG. 7, the method for managing a holding table according to this embodiment includes a first calculation step S1, a chip manufacturing step S2, a second calculation step S3, a determination step S4, and a notification step S5. In this embodiment, each step constituting the method for managing a holding table and the method for manufacturing a chip is performed based on an instruction from a controller 46.

[0055] In a first calculation step S1, under the control of the image acquisition unit 52, an image of an area (first area) including the clearance groove 14c of the holding table 14 is captured by the camera 36, ​​and the width of the clearance groove 14c is calculated. Fig. 8 is an image of the first area 23 of the holding table 14 captured by the camera 36 in the first calculation step S1. The first area 23 shown in Fig. 8 includes a part of the clearance groove 14c and a part of the suction hole 14d. For ease of explanation, the image in Fig. 8 also shows a reference line 62 of the camera 36.

[0056] First, the positions of the holding table 14 and the camera 36 are adjusted so that the reference line 62 set on the camera 36 coincides with the center line (line passing through the center) 25 in the width direction of the clearance groove 14c of the holding table 14. Specifically, for example, the orientation of the holding table 14 around a rotation axis approximately parallel to the Z-axis direction is adjusted by the rotation drive source so that the clearance groove 14c of the holding table 14 becomes approximately parallel to the X-axis direction. Note that the center line 25 does not appear in the actual image, but is shown in FIG. 8 for convenience of explanation.

[0057] Then, the position of the holding table 14 in the X-axis direction is adjusted by the X-axis moving mechanism, and the position of the camera 36 in the Y-axis direction is adjusted by the cutting unit moving mechanism 20 so that the imaging range of the camera 36 is positioned in the first region 23.

[0058] After or before aligning the reference line 62 set on the camera 36 with the center line in the width direction of the escape groove 14c of the holding table 14, the position of the camera 36 in the Z-axis direction is adjusted by the Z-axis moving plate 30 so that the focus of the camera 36 is aligned with the escape groove 14c of the holding table 14.

[0059] After the position of the reference line 62 of the camera 36 is aligned with the center line 25 of the clearance groove 14c, the first region 23 is imaged by the camera 36. Image information obtained by imaging the first region 23 is transmitted to the image processing unit 54 of the processing device 48. The image processing unit 54 calculates the width a1 of the clearance groove 14c based on the image information relating to the first region 23. The calculated width a1 of the clearance groove 14c is stored in the storage device 50.

[0060] Next, the chip manufacturing step S2 is executed. First, the workpiece 11 is carried into the holding unit 10 by the above-mentioned transport mechanism, and the workpiece 11 is held by the holding unit 10. As described above, in this embodiment, the second surface 11b side of the workpiece 11 is held by the holding unit 10 so that the first surface 11a side of the workpiece 11 is exposed.

[0061] Specifically, the conveying mechanism brings the workpiece 11 into contact with the first surface 14a of the holding table 14 so that the positions of the planned dividing lines 19 of the workpiece 11 correspond to the positions of the clearance grooves 14c. Next, the valve 42a is opened, and the negative pressure of the suction source 44 acts on the second surface 11b of the workpiece 11 via the first flow path 12b and the suction holes 14d. As a result, the second surface 11b of the workpiece 11 is sucked and held by the holding table 14. That is, the workpiece 11 is held by the holding unit 10.

[0062] Next, under the control of the cutting control unit 60, cutting is performed to divide the workpiece 11 at the planned dividing lines 19. First, the cutting blade 38 of the cutting unit 16 is aligned with the workpiece 11. Specifically, for example, the rotary drive source rotates the holding table 14 around the Z axis so that the length direction of one of the multiple planned dividing lines 19 set on the first surface 11a of the workpiece 11 becomes approximately parallel to the X axis.

[0063] Also, the position of the holding table 14 in the X-axis direction is adjusted by the X-axis movement mechanism, and the position of the cutting unit 16 in the Y-axis direction is adjusted by the cutting unit movement mechanism 20, so that the cutting blade 38 is positioned above an extension of the planned division line 19. Furthermore, the height of the cutting unit 16 is adjusted by the cutting unit movement mechanism 20, so that the lower end of the cutting blade 38 is positioned a predetermined distance below the second surface 11b of the workpiece 11.

[0064] Next, the motor, which is a rotary drive source, rotates the cutting blade 38 together with the spindle, while the X-axis movement mechanism moves the holding table 14 along the X-axis. As a result, the cutting blade 38 and the holding table 14 move relatively along the X-axis (processing feed), and the cutting blade 38 cuts into the workpiece 11 along the intended division line 19.

[0065] For example, the processing feed speed (the speed at which the holding table 14 is fed in the X-axis direction) is set to 5 mm / sec or more and 200 mm / sec or less, typically 5 mm / sec. The rotation speed (number of rotations) of the spindle is set to 20,000 rpm or more and 45,000 rpm or less, typically 30,000 rpm.

[0066] After cutting one planned dividing line 19 and cutting the workpiece 11 at this planned dividing line 19 is completed, cutting is performed in a similar procedure along another planned dividing line 19. By repeating this process and cutting the workpiece 11 along all planned dividing lines 19 set on the workpiece 11, a plurality of regions separated by a plurality of planned dividing lines 19 are divided into individual chips.

[0067] After cutting is completed, each chip on the holding table 14 is collected, for example, by dropping into a collection box (not shown) installed near the cutting device 2. However, each chip may also be collected by being picked up by a pickup mechanism (not shown). Also, each chip may be collected by any other method.

[0068] The above-mentioned procedure and operation are repeated until cutting is completed for a predetermined number of workpieces 11. The predetermined number is set in consideration of the material of the holding table 14 (how easily the holding table 14 wears), the material of the workpieces 11 (damage caused by cutting chips to the holding table 14), the cutting conditions, etc., within a range in which the escape grooves 14c and the suction holes 14d are not connected due to wear.

[0069] Next, a second calculation step S3 is executed. In the second calculation step S3, under the control of the image acquisition unit 52, the first area 23 photographed in the above-mentioned first calculation step S1 is imaged again by the camera .

[0070] As in the first calculation step S1, the positions of the holding table 14 and the camera 36 are adjusted. First, the positions of the holding table 14 and the camera 36 are adjusted so that the reference line 62 set on the camera 36 coincides with the center line 25 in the width direction of the clearance groove 14c of the holding table 14. Specifically, for example, the orientation of the holding table 14 around a rotation axis approximately parallel to the Z-axis direction is adjusted by the rotation drive source so that the clearance groove 14c of the holding table 14 becomes approximately parallel to the X-axis direction.

[0071] Then, the position of the holding table 14 in the X-axis direction is adjusted by the X-axis moving mechanism, and the position of the camera 36 in the Y-axis direction is adjusted by the cutting unit moving mechanism 20 so that the imaging range of the camera 36 is positioned in the first region 23.

[0072] After the position of the reference line 62 of the camera 36 is aligned with the center line 25 of the clearance groove 14c, the first region 23 is imaged by the camera 36. Image information obtained by imaging the first region 23 is transmitted to the image processing unit 54 of the processing device 48. FIG. 9 shows an image of the first region 23 of the holding table 14 imaged by the camera 36 in the second calculation step S3. For ease of explanation, the image in FIG. 9 also shows the reference line 62 and the center line 25 of the camera 36. The image processing unit 54 calculates the width a2 of the clearance groove 14c based on the image information related to the first region 23. The calculated width a2 of the clearance groove 14c is stored in the storage device 50.

[0073] 8 and 9, the holding table 14 is worn down by performing the chip manufacturing step S2, and the width of the clearance groove 14c increases. That is, the width of the clearance groove 14c becomes a2 from a1. As described above, this is because the cutting blade 38 meanders during cutting, and cutting chips get mixed in between the side wall of the clearance groove 14c and the cutting blade 38. When the width of the clearance groove 14c increases from a1 to a2 in this way, the distance between the clearance groove 14c and the suction hole 14d narrows from b1 to b2.

[0074] Among the multiple clearance grooves 14c, the clearance groove 14c at a position corresponding to the planned division line 19 used as a reference when aligning the holding table 14 and the cutting unit 16 has the least wear, and the wear of the clearance groove 14c tends to increase as the distance from this clearance groove 14c increases. Therefore, it is desirable to calculate the width of the clearance groove 14c that is the furthest from the clearance groove 14c at a position corresponding to the planned division line 19 used as a reference when aligning the holding table 14 and the cutting unit 16 and has the greatest amount of wear, and to determine whether or not the holding table 14 needs to be replaced.

[0075] Next, determination step S4 is executed. In determination step S4, under the control of determination unit 56, the difference (a2 - a1) between the width a1 of the escape groove 14c calculated in the first calculation step S1 and stored in the storage device 50 and the width a2 of the escape groove 14c calculated in the second calculation step S3 and stored in the storage device 50 is calculated.

[0076] Then, it is determined whether the difference (a2 - a1) between a1 and a2 is within the allowable range defined by the threshold value d1 stored in advance in the storage device 50. That is, it is determined whether a2 - a1 < d1 (or a2 - a1 ≤ d1) is satisfied. The threshold value d1 for this allowable range is determined in consideration of, for example, the distance b1 between the escape groove 14c and the suction hole 14d of the unused holding table 14.

[0077] Assuming that the distance between the escape groove 14c and the suction hole 14d is maintained at at least c (mm) or more, the condition of c ≤ b1 - (a2 - a1) / 2 < b1 - d1 / 2 is obtained. That is, in this case, the threshold value d1 is determined so as to satisfy d1 ≤ 2(b1 - c). The specific range of the threshold value d1 varies according to b1 and c, but if b1 is 0.3 mm or more and 1.0 mm or less, and c is 0.1 mm, then d1 is 0.4 mm or more and 1.8 mm or less.

[0078] When it is determined by the determination unit 56 that the difference (a2 - a1) is within the allowable range defined by the threshold value d1, a series of steps of the chip manufacturing method including the management method of the holding table according to the above-described present embodiment ends. In this case, the chip manufacturing step S2, the second calculation step S3, and the determination step S4 may be executed again.

[0079] On the other hand, when the determination unit 56 determines that the difference (a2-a1) is outside the allowable range defined by the threshold value d1, a notification step S5 is executed under the control of the notification control unit 58. The notification step S5 notifies the operator that the holding table 14 needs to be replaced. For example, the cutting device 2 may be equipped with a monitor, and the monitor may display the fact that the holding table 14 needs to be replaced. Alternatively, the cutting device 2 may be equipped with a speaker, and a warning sound or a voice announcing the fact that the holding table 14 needs to be replaced may be emitted from the speaker.

[0080] As described above, according to this embodiment, it is possible to appropriately determine whether or not the holding table 14 needs to be replaced.

[0081] In the above embodiment, in the judgment step S4, it is judged whether the difference between a1 and a2 is within the allowable range defined by the threshold value d1, but it is also possible to set a threshold value d2 for the difference in the distance between the escape groove 14c and the suction hole 14d (the difference between b1 and b2 (b1-b2)), and judge whether this difference (b1-b2) is within the allowable range defined by the threshold value d2. Furthermore, in the judgment step S4, it is also possible to set a threshold value d3 for b2 calculated in the second calculation step S3, and judge whether b2 is within the allowable range defined by the threshold value d3.

[0082] Furthermore, the judgment in the judgment step S4 is performed by the processing device 48, but may be performed by an operator. When it is not necessary to notify the operator, such as when the judgment is performed by the operator, the notification step S5 may be omitted.

[0083] In addition, the structures, methods, and the like according to the above-described embodiments and modifications may be modified and implemented without departing from the scope of the present invention. [Explanation of symbols]

[0084] 11: Workpiece 11a: Front page 11b:Second side 13:Frame body 13a: 1st page 13b: 2nd side 15: Device area 17: Surplus outer area 19: Planned division line 21: Resin layer 21a: Surface 23: Imaging area 25: Center line 2:Cutting device 4: Base 4a:Aperture 6: Table cover 8: Dust-proof and water-resistant cover 10: Holding table 12: Table base 12a: 1st page 12b: First flow path 12c: Second flow path 14: Holding table 14a: Side 1 14b:Second side 14c: Undercut 14d: Suction hole 16: Cutting unit 18:Support structure 20: Cutting unit movement mechanism 22: Y-axis guide rail 24: Y-axis moving plate 26: Y-axis ball screw 28: Z-axis guide rail 30: Z-axis moving plate 32: Z-axis ball screw 34: Z-axis pulse motor 36: Camera (imaging unit) 38: Cutting blade 40: Cutting fluid supply nozzle 42a, 42b: Valve 44: Suction source 46: Controller 48: Processing equipment 50: Storage device 52: Image acquisition unit 54: Image processing section 56: Judgment section 58: Notification control unit 60: Cutting control section 62: Reference line

Claims

1. A method for managing a holding table used when managing a holding table provided in a cutting device, comprising the steps of: The cutting device is the holding table for holding a workpiece on which a planned dividing line is set, a spindle equipped with a cutting blade for cutting the workpiece held on the holding table, and a camera for imaging the workpiece held on the holding table from above, wherein an escape groove is provided at a position on the holding table corresponding to the planned dividing line to allow the cutting blade to escape so that the cutting blade does not interfere with the holding table when the cutting blade is cut into the planned dividing line of the workpiece, The method of managing the holding table is as follows: a first calculation step of imaging an area of ​​the holding table including the clearance groove with the camera and calculating a width of the clearance groove from the obtained image; a second calculation step of imaging an area of ​​the holding table including the clearance groove with the camera after the first calculation step, and calculating a width of the clearance groove from the obtained image; a determination step, after the second calculation step, of determining whether or not a difference between the width of the escape groove calculated in the first calculation step and the width of the escape groove calculated in the second calculation step is within an allowable range defined by a preset threshold value.

2. 2. The method for managing a holding table according to claim 1, further comprising, after said judging step, a notifying step of notifying a user that the difference is not within said allowable range when said judging step is performed.

3. A chip manufacturing method including the method for managing the holding table according to claim 1 or 2, comprising the steps of: The method for manufacturing chips further includes a chip manufacturing step, after the first calculation step and before the second calculation step, of cutting the workpiece held by the holding table along the planned dividing line by cutting the cutting blade into the planned dividing line to produce a plurality of chips.

Images