Cutting device

Abstract

To provide a cutting device capable of solving a problem that it is difficult for a dressing board to be held on a chuck table when the dressing board is curved, and that time and effort are required for exchanging the used dressing board to a new one.SOLUTION: A wafer 10 is housed in an opening part Fa of a frame F provided with the opening part Fa for housing the wafer 10 at its center and is integrally formed by a tape T. A dressing mechanism 20A includes: a nozzle 21A laying a dressing member 30 onto the tape T so as to be adjacent to an outer periphery 10c of the wafer 10; and dressing member feeding means 22 feeding the dressing member 30 to the nozzle 21A.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a cutting device comprising a chuck table for holding a workpiece, cutting means having a rotatable cutting blade with cutting edges arranged on the outer periphery for cutting the workpiece held on the chuck table, and a dressing mechanism for sharpening the cutting blade. [Background technology]

[0002] Wafers, on the surface of which multiple devices such as ICs and LSIs are formed along division lines, are separated into individual device chips by a cutting machine and used in electrical equipment such as mobile phones and personal computers.

[0003] The cutting device is configured to include a chuck table that holds the wafer, cutting means equipped with a rotatable cutting blade that cuts the wafer held on the chuck table, and feeding means that feeds the chuck table and the cutting means relative to each other for processing, and can divide the wafer into individual device chips with high precision (see, for example, Patent Document 1).

[0004] In conventional cutting devices, when the cutting ability of a cutting blade decreases, a dressing board is brought into the cutting device, placed on a chuck table and held by suction in order to sharpen or shape the cutting blade, and the cutting blade is cut into the dressing board to perform sharpening (dressing).After the dressing is completed, the dressing board is taken out of the chuck table and stored in a designated storage location, which is a time-consuming process.

[0005] Furthermore, if the dressing board is curved, it becomes difficult to hold it by suction on the chuck table, so it is necessary to manage the dressing board so that it does not curve.

[0006] Furthermore, a cutting device has been proposed that includes a dedicated table for holding a dressing board, separate from a chuck table for holding a workpiece such as a wafer (see Patent Document 2). However, as with the above-mentioned conventional technology, if the dressing board is curved, it is difficult to hold it on the dedicated table, and there is also the problem that a used dressing board must be replaced with a new one, which is time-consuming. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-203429 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-216324 Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been developed in consideration of the above-mentioned facts, and its main technical object is to provide a cutting device that solves the problems that, in a cutting device that performs dressing when the cutting ability of a cutting blade decreases, it is difficult to hold a dressing board on the chuck table when the dressing board is curved, and that it is necessary to replace a used dressing board with a new one, which is time-consuming. [Means for solving the problem]

[0009] In order to solve the above-mentioned main technical problems, according to the present invention, there is provided a cutting device comprising a chuck table for holding a workpiece, cutting means having a rotatable cutting blade with cutting edges arranged on the outer periphery for cutting the workpiece held on the chuck table, and a dressing mechanism for sharpening the cutting blade, wherein the workpiece is a wafer, and the wafer is accommodated in an opening in the center of a frame and is integrally formed with tape, and the dressing mechanism comprises a nozzle for laying a dressing member on the tape adjacent to the outer periphery of the wafer, and dressing member delivery means for delivering the dressing member to the nozzle.

[0010] The dressing element is formed by mixing dressing abrasive grains with a fluid binder, and the dressing element delivery means includes a storage section for storing the dressing element and a tube for delivering the dressing element from the storage section to the nozzle. The dressing element delivery means may also include a reel around which a dressing wire formed by mixing dressing abrasive grains with a thermoplastic resin is wound, and a dressing wire delivery section for delivering the dressing wire from the reel to the nozzle, and the nozzle may also include a heating section for heating and fluidizing the delivered dressing wire. The binder preferably includes a thermoplastic resin or a gelling agent, and the dressing abrasive grains preferably include silicon carbide, alumina, or diamond. [Effects of the Invention]

[0011] The cutting device of the present invention includes a chuck table for holding a workpiece, a cutting means having a rotatable cutting blade with cutting edges disposed on the periphery for cutting the workpiece held on the chuck table, and a dressing mechanism for sharpening the cutting blade, wherein the workpiece is a wafer, and the wafer is accommodated in a frame having a central opening for accommodating the wafer and integrally formed with tape, and the dressing mechanism includes a nozzle for laying a dressing member on the tape adjacent to the periphery of the wafer and a dressing member delivery means for delivering the dressing member to the nozzle. This eliminates the need for separate dressing during cutting, eliminating the need for separate dressing after cutting. This eliminates the need for a dressing board to be placed on the chuck table, held by suction for dressing, and then removed after dressing. This also eliminates the need for a bent dressing board that cannot be properly held on the chuck table. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is an overall perspective view of a cutting device according to an embodiment of the present invention; [Figure 2] 2 is a perspective view showing the configuration of a dressing mechanism disposed in the cutting device shown in FIG. 1. FIG. [Figure 3] 1. FIG. 4 is a perspective view showing another embodiment of the dressing mechanism disposed in the cutting device shown in FIG. [Figure 4] FIG. 10 is a perspective view showing a configuration in which a dressing member is laid adjacent to the outer periphery of a wafer. [Figure 5] 2 is a perspective view showing an embodiment in which cutting and dressing are performed simultaneously in the cutting device of FIG. 1. FIG. [Figure 6] FIG. 10 is a perspective view showing another embodiment in which a dressing member is laid adjacent to the outer periphery of the wafer. DETAILED DESCRIPTION OF THE INVENTION

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a cutting device 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 cutting device 1 of this embodiment. The illustrated cutting device 1 includes a chuck table 7 that holds a workpiece, cutting means 8 that is rotatably equipped with a cutting blade 83 that has cutting edges arranged on the periphery to cut the workpiece held on the chuck table 7, and a dressing mechanism 20A (details of which will be described later) that sharpens the cutting blade 83. The workpiece to be processed by the cutting device 1 is, for example, a semiconductor wafer 10, which is integrated with an annular frame F by an adhesive tape T (see also FIG. 2).

[0015] As shown in FIG. 1, the cutting device 1 has a housing 2 having a substantially rectangular parallelepiped shape, and includes a cassette 4 placed on a cassette table 4a that can be raised and lowered, a carry-in / out means 3 that carries out the wafer 10 held in a frame F from the cassette 4 to a temporary storage table 5, a transport means 6 having a swivel arm that transports the wafer 10 carried out to the temporary storage table 5 to a chuck table 7 having a holding surface 7a, a cutting means 8 including a cutting blade 83 disposed as a processing means for processing the wafer 10 held on the chuck table 7, and a wafer 10 held on the chuck table 7. The apparatus is equipped with an alignment means 9 that takes an image of the wafer 10 held thereon and detects the processing position to be cut by the cutting blade 83 of the cutting means 8, a cleaning device 11 (details omitted) that cleans the wafer 10 that has been transported from the transport position where the chuck table 7 is positioned in Figure 1, a cleaning and transport means 12 that transports the wafer 10 to the cleaning device 11, a dressing mechanism 20A that sharpens the cutting blade 83 including a nozzle 21A arranged adjacent to the alignment means 9 in the Y-axis direction, and a control means not shown.

[0016] The holding surface 7a of the chuck table 7 is a substantially horizontal XY plane defined by the X-axis direction and the Y-axis direction perpendicular to the X-axis direction. The holding surface 7a is made of a breathable material, and is connected to a suction means (not shown). Activating the suction means generates negative pressure on the holding surface 7a. A plurality of clamps 7b (four in the illustrated embodiment) are evenly spaced around the periphery of the chuck table 7 to grip a frame F that supports the wafer 10. Inside the housing 2, there are also provided an X-axis feed means for moving the chuck table 7 in the X-axis direction, a Y-axis feed means for moving the cutting means 8 in the Y-axis direction, a Z-axis feed means for moving the cutting means 8 in the Z-axis direction (up and down), a rotary drive means for rotating the chuck table 7, and other components (none of which are shown).

[0017] The control means is connected to at least the above-mentioned operating parts of the cutting device 1. The control means 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 and the like, a readable and writable random access memory (RAM) that temporarily stores detected values, calculation results, and the like, an input interface, and an output interface (details not shown in the drawings).

[0018] With reference to FIG. 2, the dressing mechanism 20A disposed in the cutting device 1 will be described in more detail.

[0019] 2 includes a nozzle 21A that ejects a dressing member 30, and a dressing member delivery means 22 that delivers the dressing member 30 to the nozzle 21A. As can be seen from FIG. 1, the nozzle 21A is disposed, for example, adjacent to the alignment means 9 in the Y-axis direction, and above the path along which the chuck table 7 moves in the X-axis direction.

[0020] The dressing member delivery means 22 includes a storage section 221 for storing the dressing member 30, and a tube 222 for delivering the fluid dressing member 30 from the storage section 221 to the nozzle 21A.

[0021] The reservoir 221 is provided with a heater (e.g., a Peltier element) 221a for heating the dressing material 30 stored in the reservoir 221 as needed to maintain the fluidity of the stored dressing material 30, and a vibration imparting means (e.g., a piezoelectric element) 221b for imparting vibrations to the reservoir 221 to agitate the dressing material 30 stored in the reservoir 221. In the illustrated embodiment, an on-off valve 23 and a pump 24 are provided on the tube 222 and controlled by the control means. By opening the on-off valve 23 and operating the pump 24 by the control means, the dressing material 30 stored in the reservoir 221 can be pressure-fed through the tube 222 in the direction indicated by arrow R1, introduced through the inlet 21Aa of the nozzle 21A, and discharged from the nozzle tip 21Ab at any desired timing.

[0022] The dressing member 30 stored in the storage section 221 can be constructed by kneading dressing abrasive grains with a fluid binder, the binder being, for example, a thermoplastic resin or a gelling agent, and the dressing abrasive grains include abrasive grains made of any of silicon carbide, alumina, and diamond, to form the dressing member 30.

[0023] As the thermoplastic resin, it is preferable to use any one of polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyvinyl acetate, polyurethane, ABS resin, AS resin, acrylic resin, polylactic acid, polyetherimide, polyamide nylon, polyacetal, polycarbonate, modified polyphenylene ether, polyethylene terephthalate, polybutylene terephthalate, cyclic polyolefin, polyphenylene sulfide, polytetrafluoroethylene, polysulfone, polyethersulfone, amorphous polyalitate, liquid crystal polymer, polyetheretherketone, thermoplastic polyimide, and polyamideimide.

[0024] As the gelling agent, it is preferable to use, for example, any one of pectin, guar gum, xanthan gum, tamarind gum, carrageenan, propylene glycol, carboxymethyl cellulose, gelatin, and agar.

[0025] In the configuration of the above-described embodiment, the pump 24 is disposed on the tube 222 to pressure-feed the dressing member 30 stored in the storage portion 221 toward the nozzle 21A, but the present invention is not limited to this, and pressure-feeding may be performed by other means. For example, without disposing the pump 24 on the tube 222, the dressing member 30 stored in the storage portion 221 can be pressure-feed toward the nozzle 21A by sealing the internal space of the storage portion 221 in which the dressing member 30 is stored and putting it into a high-pressure state, and opening the on-off valve 23.

[0026] The dressing mechanism applicable to the present invention is not limited to the above-described dressing mechanism 20 A. For example, instead of the above-described dressing mechanism 20 A, another dressing mechanism 20 B shown in FIG. 3 may be disposed in the cutting device 1.

[0027] The dressing mechanism 20B shown in FIG. 3 includes a nozzle 21B and a dressing member delivery means 40. The illustrated dressing member delivery means 40 includes a reel 41 around which a dressing wire 31, which is a wire-shaped dressing member formed by mixing dressing abrasive grains with a thermoplastic resin, is wound, and a dressing wire delivery unit 42 that delivers the dressing wire 31 from the reel 41 to the nozzle 21B. The nozzle 21B includes a nozzle body 21Ba and a heating unit 21Bb. The thermoplastic resin constituting the dressing wire 31 and the dressing abrasive grains mixed with the thermoplastic resin can be selected from the thermoplastic resins and dressing abrasive grains disclosed in the description of the dressing mechanism 20A above.

[0028] The dressing wire feed unit 42 includes a drive motor 42a, a drive roller 42c disposed at the tip of a rotary shaft 42b of the drive motor 42a, and a guide roller 43 driven by the drive roller 42c. The drive motor 42a is controlled by the control means. The control means activates the drive motor 42a, causing the drive motor 42a to rotate the drive roller 42c in the direction indicated by arrow R3. This rotates the guide roller 43 in the direction indicated by arrow R4, and the dressing wire 31 wound around the guide roller 43 is pulled out. This rotates the reel 41 in the direction indicated by arrow R5, and the dressing wire 31 is introduced through an inlet 21Bc formed in the heating unit 21Bb. The dressing wire 31 introduced through the inlet 21Bc is heated and fluidized by the heating unit 21Bb, becoming the dressing member 30 and being discharged from the nozzle tip 21Bd of the nozzle 21B. The dressing mechanism 20B can also discharge the dressing member 30 from the nozzle 21B at any timing, similar to the above-described dressing mechanism 20A.

[0029] The cutting device 1 of this embodiment has roughly the configuration as described above, and an embodiment in which the wafer 10 is cut in the cutting device 1 and the cutting blade 83 of the cutting means 8 is sharpened (dressed) by a dressing mechanism configured based on the present invention will be specifically described. Note that in the embodiment described below, the cutting device 1 will be described as being provided with the dressing mechanism 20A described based on Fig. 2 as the dressing mechanism.

[0030] The wafer 10, which is the workpiece of the above-mentioned cutting device 1, is a semiconductor wafer, for example, 200 μm thick and 300 mm in diameter, and as shown in FIG. 2, a plurality of devices D are formed on the surface 10a, partitioned by planned division lines L. The wafer 10 is housed with the surface 10a facing upward in the center of an opening Fa of an annular frame F having an opening Fa capable of accommodating the wafer 10, and a tape T is attached to the back surface of the wafer 10 and the frame F to form an integral unit.

[0031] When cutting the wafer 10, the wafer 10 is transported from the cassette 4 onto the temporary placement table 5 by the above-mentioned transport means 3 and aligned, the frame F is adsorbed by the transport means 6, and the frame F is transported and placed on the holding surface 7a of the chuck table 7, a negative pressure is generated on the holding surface 7a of the above-mentioned chuck table 7 to suck in the wafer 10, and the frame F is gripped by the clamp 7b to hold the wafer 10.

[0032] Once the wafer 10 is held on the chuck table 7 as described above, the X-axis feed means is operated to position the wafer 10 directly below the alignment means 9, and an image of the wafer 10 is taken. When dressing the cutting blade 83 attached to the cutting means 8, the alignment means 9 detects the outer periphery 10c of the wafer 10 (see FIG. 2) and the position of the planned dividing line L to be processed. Then, the X-axis feed means is operated to move the chuck table 7, and the nozzle 21A of the dressing mechanism 20A is positioned on the tape T that integrally forms the frame F and the wafer 10, directly above a position adjacent to the outer periphery 10c of the wafer 10, as shown in FIG.

[0033] The operator can instruct the control means of the cutting device 1 to perform dressing at any timing; for example, the operator can inspect the cut groove 100 cut by the cutting blade 83 and determine, based on the inspection results, that it is time to perform dressing on the cutting blade 83. The control means can also notify the operator that it is time to perform dressing on the cutting blade 83 and urge the operator to perform dressing. The control means can determine that it is time to perform dressing on the cutting blade 83 by, for example, the number of wafers that have been cut has reached a predetermined number, the time for which cutting has been performed has reached a predetermined time, etc.

[0034] 2, when the nozzle 21A of the dressing mechanism 20A is positioned directly above a position adjacent to the outer periphery 10c of the wafer 10, the on-off valve 23 on the tube 222 of the dressing mechanism 20A is opened and the pump 24 is operated to discharge the dressing material 30 from the nozzle 21A so that the dressing material 30 is sent to the nozzle 21A by the dressing material sending means 22. At the same time, the rotation drive means disposed on the chuck table 7 is operated to rotate the frame F holding the wafer 10 once in the direction indicated by arrow R2. As a result, the dressing material 30 is laid on the tape T adjacent to the outer periphery 10c of the wafer 10 all around. The speed at which the frame F rotates in the direction indicated by the arrow R2 is set to a speed at which a uniform amount of the dressing material 30 is laid on the outer periphery 10c of the wafer 10, corresponding to the amount of the dressing material 30 discharged from the nozzle 21A.

[0035] In the above embodiment, the dressing mechanism 20A described based on Figure 2 was used to lay the dressing member 30 adjacent to the outer periphery 10c of the wafer 10, but even if the dressing mechanism 20B described based on Figure 3 is used, it is possible to lay the dressing member 30 adjacent to the outer periphery 10c of the wafer 10, as with the above dressing mechanism 20A.

[0036] As described above, once the dressing members 30 have been laid annularly on the tape T adjacent to the outer periphery 10c of the wafer 10, the X-axis feed means and rotation drive means are operated to align the predetermined dividing line L detected by the alignment means 9 in the X-axis direction, and the chuck table 7 is moved in the X-axis direction to position it directly below the cutting means 8. As shown in Fig. 5, the cutting means 8 includes a spindle housing 81 supporting a spindle 82 rotatably in the Y-axis direction, a blade cover 85 covering a cutting blade 83 supported at the tip of the spindle 82, a cutting water supply nozzle 84 supplying cutting water to the cutting location, and a drive motor (not shown) for rotating the spindle 82. The cutting blade 83 is positioned outside the area where the dressing members 30 are laid annularly, and the drive motor is operated to rotate the cutting blade 83 at high speed in the direction indicated by arrow R7.

[0037] Next, the Z-axis feed means is operated to cut along the planned dividing line L aligned in the X-axis direction to a predetermined depth slightly exceeding the thickness of the wafer 10 (200 μm) as shown in Fig. 5, and the X-axis feed means is operated to feed the wafer 10 in the X-axis direction to form the kerf 100. What is important here is that the cutting blade 83 is cut so as to cross the dressing member 30 laid adjacent to the outer periphery 10c of the wafer 10.

[0038] Furthermore, the Y-axis feed means is operated to index and feed the cutting blade 83 of the cutting means 8 in the Y-axis direction according to the distance (e.g., 5 mm) between the dividing line L on which the cutting groove 100 has been formed and an uncut dividing line L adjacent in the Y-axis direction and on which no cutting groove 100 has been formed, and the cutting blade 81 is positioned at the uncut dividing line L and fed for cutting, thereby performing cutting so as to pass through the dressing member 30 from the outside of the dressing member 30 in the same manner as above, thereby forming the cutting groove 100. By repeating these steps, the cutting grooves 100 are formed along all the dividing lines L along the X-axis direction. Next, the chuck table 7 holding the wafer 10 is rotated 90 degrees, and the direction perpendicular to the direction in which the cutting grooves 100 were previously formed is aligned with the X-axis direction. Then, by performing the above-mentioned cutting process on all of the planned dividing lines L that have been newly aligned in the X-axis direction, cutting is performed so that the cutting passes through the dressing member 30, forming cutting grooves 100 along all of the planned dividing lines L formed on the wafer 10, and the wafer 10 can be divided into individual device chips.

[0039] In the cutting process described above, the dressing member 30 is passed when the cutting blade 83 is cut from the outer periphery of the wafer 10 along the predetermined dividing line L, and the dressing member 30 can be passed even after the predetermined dividing line L is cut to form the cut groove 100. As a result, dressing is performed simultaneously with the cutting process, eliminating the need to perform dressing separately from the cutting process. In other words, this solves the problem of placing the dressing board on the chuck table 7, holding it by suction, performing dressing, and then having to transport the dressing board after performing dressing, which is time-consuming, and also solves the problem of the dressing board bending and not being able to be properly held on the chuck table 7.

[0040] In addition, when performing cutting processing on the wafer 10, if it is not determined that dressing should be performed on the cutting blade 83 attached to the cutting means 8, only cutting processing to form the cutting groove 100 in the wafer 10 is performed without operating the above-mentioned dressing mechanism 20A.

[0041] In the above-described embodiment, the dressing member 30 is laid over the entire circumference adjacent to the outer periphery of the wafer 10 as shown in FIG. 4 , but the present invention is not limited to this. For example, using the dressing mechanism 20A or the dressing mechanism 20B, the dressing member 30 may be laid over only half the circumference at a position adjacent to the outer periphery of the wafer 10 on the tape T as shown in FIG. 6 . In this case, the dressing member 30 may be laid over a region where the dressing member 30 passes before or after forming the kerf 100 along the division line L of the wafer 10 using the cutting means 8. Furthermore, the dressing member 30 is not necessarily laid over the entire circumference or half the circumference. It may be laid over a narrower region or intermittently in multiple regions, or the dressing member 30 may be laid in a spotted manner only at a position corresponding to the division line L. [Explanation of symbols]

[0042] 1:Cutting device 2: Housing 3: Carrying in / out means 4: Cassette 5: Temporary table 6: Means of transport 7: Chuck table 7a: Holding surface 7b: Clamp 8: Cutting means 83: Cutting blade 9: Alignment means 10: Wafer 10a: surface 10c: outer circumference 11: Cleaning equipment 12: Cleaning and carrying out means 20A: Dressing mechanism 21A: Nozzle 21Ab: Nozzle tip 22: Dressing member feeding means 221: Storage section 221a: Heater 221b: Piezo element 222:Tube 23: On-off valve 24: Pump 20B: Dressing mechanism 21B: Nozzle 21Ba: Nozzle body 21Bb: Heating section 21Bc: Entrance 21Bd: Nozzle tip 30: Dressing material 31: Dressing wire 40: Dressing member delivery means 41: Reel 42: Dressing wire feed section 42a: Drive motor 42b: Rotation axis 42c: Drive roller 43: Guide roller 100: Cutting groove D:Device F: Frame L: Planned division line

Claims

1. A cutting device comprising: a chuck table for holding a workpiece; cutting means having a rotatable cutting blade with a cutting edge disposed on the outer periphery for cutting the workpiece held on the chuck table; and a dressing mechanism for sharpening the cutting blade, the workpiece is a wafer, and the wafer is accommodated in a frame having an opening at the center thereof and is integrally formed with the frame by a tape; The dressing mechanism is a cutting device comprising a nozzle for laying a dressing material on the tape adjacent to the outer periphery of the wafer, and a dressing material delivery means for delivering the dressing material to the nozzle.

2. The dressing member is formed by kneading dressing abrasive grains into a binder having fluidity, 2. The cutting device according to claim 1, wherein the dressing material delivery means comprises a reservoir for storing the dressing material, and a tube for delivering the dressing material from the reservoir to the nozzle.

3. The dressing member delivery means includes a reel around which a dressing wire formed into a wire shape by kneading dressing abrasive grains into a thermoplastic resin is wound, and a dressing wire delivery unit that delivers the dressing wire from the reel to the nozzle, 2. The cutting device according to claim 1, wherein the nozzle is provided with a heating section for heating and fluidizing the delivered dressing wire.

4. 3. The cutting device according to claim 2, wherein the binder contains either a thermoplastic resin or a gelling agent, and the dressing abrasive grains contain either silicon carbide, alumina, or diamond.

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