JP5764031B2 - Cutting equipment - Google Patents

Description

  The present invention relates to a cutting device for cutting a workpiece held on a chuck table.

  A wafer on which a plurality of devices such as IC and LSI are formed is chamfered on the outer periphery in order to prevent cracking and dust generation during the manufacturing process. Therefore, when the wafer is thinly ground, the chamfered portion on the outer periphery is formed in a knife edge shape (eave shape). When the chamfered portion of the outer periphery has a knife edge shape, there is a possibility that a problem arises that the wafer is damaged due to chipping from the outer periphery. Therefore, a technique has been proposed in which the chamfered portion of the outer periphery is cut in the circumferential direction with a cutting blade in advance and a part of the outer periphery is removed in the Z-axis direction, and then the back surface of the wafer is ground (see, for example, Patent Document 1) ).

  Here, when the outer periphery of the wafer is cut in the circumferential direction by the cutting blade, the portion contributing to the cutting of the tip of the cutting blade is consumed, and the other portions are not consumed and uneven wear occurs. When uneven wear occurs, cutting with high accuracy cannot be performed. Therefore, before the uneven wear proceeds, a flat dress in which the tip of the cutting blade is shaped flat with a dresser board is performed (see, for example, Patent Document 2). ).

JP 2000-173961 A JP 2010-588 A

  However, the conventional flat dress has a problem that the work held on the chuck table is removed and the dresser board is placed and held on the chuck table, that is, the work is complicated. . In addition, after performing a flat dress, the dresser board held on the chuck table must be removed, and the workpiece must be placed and held on the chuck table again. Cutting the workpiece to perform the flat dress There is a problem that the time for interrupting the processing becomes longer and the productivity is lowered.

  The present invention has been made in view of the above, and an object of the present invention is to provide a cutting apparatus capable of at least one of simplification of work in a flat dress and improvement of productivity.

In order to solve the above-described problems and achieve the object, a cutting apparatus according to the present invention includes a chuck table for holding a workpiece on a horizontal surface, a rotatable spindle, and a cutting blade attached to the spindle. Cutting means having a Y-axis moving means for moving the spindle in the Y-axis direction that is parallel to the rotation axis of the spindle, and moving the spindle in the Z-axis direction that is a direction to approach and separate from the chuck table A cutting device comprising: a Z-axis moving means that further comprises dressing means disposed adjacent to the chuck table and on a moving path of the cutting blade by the Y-axis moving means, the dressing means comprising : It has a de Lesser board, holding the dresser board, and a rotatable holding means about the axis, is held by the holding means The height of the polishing surface of Lesser board, wherein the height and the same or lower surface of the chuck table.

  Further, in the cutting apparatus, when the cutting blade is dressed by the dressing means, the cutting blade is moved to a predetermined cutting position facing the dresser board in the Y-axis direction and rotated from the predetermined cutting position. The blade is moved in a direction in contact with the polishing surface by the Y-axis moving means, and after the cutting blade and the polishing surface are not in contact, the cutting of the polishing surface on the movement path in the Z-axis direction is performed. It is preferable to rotate the holding means so that the regions excluding the traces face each other.

  In the cutting apparatus, it is preferable that the dressing means is disposed so that the central axis is located on the rotational axis.

  In the cutting apparatus of the present invention, a rotatable dresser board is provided separately from the chuck table holding the workpiece, the cutting blade is moved relative to the dresser board by the Y-axis moving means and the Z-axis moving means, Do a flat dress. Therefore, since the workpiece is not removed from the chuck table for performing the flat dress, the work can be simplified. Further, since the flat dress can be performed using the time during which the workpiece is not cut by the cutting blade, the time for interrupting the cutting process can be shortened, and the productivity can be improved. There is an effect that can be done.

Drawing 1 is a figure showing the example of composition of the cutting device concerning an embodiment. FIG. 2 is a diagram showing the cutting means and the dressing means. FIG. 3 is a diagram showing the positional relationship between the cutting means and the dressing means. FIG. 4 is a diagram illustrating a flow of a flat dress by the cutting apparatus according to the embodiment.

  DESCRIPTION OF EMBODIMENTS Embodiments (embodiments) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited by the contents described in the following embodiments. The constituent elements described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the structures described below can be combined as appropriate. Various omissions, substitutions, or changes in the configuration can be made without departing from the scope of the present invention.

  Drawing 1 is a figure showing the example of composition of the cutting device concerning an embodiment. FIG. 2 is a diagram showing the cutting means and the dressing means. FIG. 3 is a diagram showing the positional relationship between the cutting means and the dressing means. FIG. 3 is a view of the cutting means and the dressing means as seen from the Z-axis direction, and schematically shows the cutting means.

  The cutting apparatus according to the present embodiment cuts a workpiece by relatively moving a cutting means having a cutting blade and a chuck table holding the workpiece. As shown in FIG. 1, the cutting device 1 is a two-spindle dicer, a so-called twin dicer, and includes a chuck table 10, two cutting means 20a and 20b, two Y-axis moving means 30a and 30b, and two Z The shaft moving means 40a and 40b, the two dressing means 50a and 50b, and the control means 90 are comprised. The cutting apparatus 1 according to the present embodiment further includes an X-axis moving unit (not shown), a cassette elevator 60, a temporary placing unit 70, and a cleaning / drying unit 80. The cutting apparatus 1 is provided with a gate-shaped column portion 3 on an apparatus main body 2.

  The chuck table 10 holds the workpiece W on a horizontal surface. In this embodiment, the chuck table 10 holds the workpiece W by sucking it from the back surface of the workpiece W. The portion constituting the surface of the chuck table 10 has a disk shape made of porous ceramic or the like, and is connected to a vacuum suction source (not shown) via a vacuum suction path (not shown). A pair of clamp portions 11 are provided around the chuck table 10. The clamp unit 11 is driven by an air actuator and clamps the frame F around the workpiece W.

  Here, the workpiece W is a workpiece to be processed by the cutting device 1, and is a wafer having, as a base material, silicon, sapphire, gallium, or the like in the present embodiment. The workpiece W has a device-side surface on which a plurality of devices are formed and a back surface opposite to the device-side surface is attached to the dicing tape T, and the dicing tape T attached to the workpiece W is attached to the frame F. Thus, the frame F is fixed.

  The X-axis moving means moves the workpiece W held with respect to the cutting blade 21 relative to the X-axis direction. The X-axis moving means is provided so that the column part 3 straddles the apparatus main body 2, and includes an X-axis ball screw, an X-axis pulse motor, and a pair of X-axis guide rails. The X-axis ball screw is disposed in the X-axis direction, is screwed with a nut (not shown) provided at the lower portion of the table moving base 4, and an X-axis pulse motor is connected to one end. The pair of X-axis guide rails are formed in parallel with the X-axis ball screw, and the table moving base 4 is slidably mounted thereon. The X-axis moving means rotates and drives the X-axis ball screw by the rotational force generated by the X-axis pulse motor, thereby guiding the table moving base 4 (chuck table 10) by a pair of X-axis guide rails. 2 in the X-axis direction.

  Here, the table moving base 4 is supported in the apparatus main body 2 so as to be rotatable about the central axis of the table moving base 4. The table moving base 4 is connected to a base driving source (not shown) housed in the apparatus main body 2. The table moving base 4 can be rotated at an arbitrary angle, for example, 90 degrees or continuously by a rotational force generated by the base driving source, and the chuck moving table 4 with respect to the cutting blades 21a and 21b. Rotation drive such as arbitrary angle rotation or continuous rotation can be performed around the central axis of the.

  The cutting means 20a and 20b cut the workpiece W held on the chuck table 10 with the cutting blades 21a and 21b. The cutting means 20a is supported by the support portion 5a, and is provided on one of the column portions 3 via the Y-axis moving means 30a, the Z-axis moving means 40a, and the blade moving base 6a. The cutting means 20b is supported by the support portion 5b, and is provided on the other side of the column portion 3 via the Y-axis moving means 30b, the Z-axis moving means 40b, and the blade moving base 6b. The two cutting means 20a and 20b are provided to face each other with the chuck table 10 interposed therebetween. As shown in FIG. 2, the cutting blades 21a and 21b are extremely thin cutting grindstones having a substantially ring shape, and are detachably attached to the spindles 22a and 22b, respectively. The spindles 22a and 22b are rotatably supported by cylindrical housings 23a and 23b, respectively, and are connected to blade drive sources (not shown) respectively housed in the housings 23a and 23b. The cutting blades 21a and 21b are rotationally driven by the rotational force generated by the blade driving source. As shown in FIG. 3, the cutting means 20a and 20b are provided such that the spindles 22a and 22b are parallel to the rotation axis A of the spindles 22a and 22b and the Y-axis direction.

  As shown in FIG. 1, the Y-axis moving means 30a and 30b move the cutting blades 21a and 21b relative to the workpiece W and the guide means 50a and 50b held in the chuck table 10 in the Y-axis direction, respectively. Is. The Y-axis moving means 30a and 30b are respectively provided in the column portion 3, and each include Y-axis ball screws 31a and 31b, Y-axis pulse motors 32a and 32b, and a pair of Y-axis guide rails 33. Has been. The Y-axis ball screws 31a and 31b are arranged in the Y-axis direction, are respectively screwed with nuts (not shown) provided in the blade movement bases 6a and 6b, and have one end a Y-axis pulse motor 32a. , 32b are connected to each other. The pair of Y-axis guide rails 33 are formed in parallel with the Y-axis ball screws 31a and 31b, and the blade movement bases 6a and 6b are slidably mounted thereon. The Y-axis moving means 30a and 30b rotate the Y-axis ball screws 31a and 31b by the rotational force generated by the Y-axis pulse motors 32a and 32b, thereby moving the blade moving bases 6a and 6b to a pair of Y-axis guide rails. While being guided by 33, it is moved in the Y-axis direction with respect to the apparatus main body 2.

  The Z-axis moving means 40a, 40b moves the cutting blades 21a, 21b in the Z-axis direction, that is, the spindles 22a, 22b approach the chuck table 10 with respect to the workpiece W and the guide means 50a, 50b held on the chuck table 10. And relative movement in the separating direction. The Z-axis moving means 40a, 40b are provided on the blade moving bases 6a, 6b, respectively, Z-axis ball screws 41a, 41b, Z-axis pulse motors 42a, 42b, and a pair of Z-axis guide rails 43a, 43b. And each is configured. The Z-axis ball screws 41a and 41b are disposed in the Z-axis direction, screwed into nuts (not shown) provided in the support portions 5a and 5b, respectively, and Z-axis pulse motors 42a and 42b at one end. Are connected to each other. The pair of Z-axis guide rails 43a and 43b are formed in parallel with the Z-axis ball screws 41a and 41b, and the support portions 5a and 5b are slidably mounted thereon. The Z-axis moving means 40a and 40b rotate the Z-axis ball screws 41a and 41b by the rotational force generated by the Z-axis pulse motors 42a and 42b, so that the support portions 5a and 5b are paired with the pair of Z-axis guide rails 43a and 43b. It is moved in the Z-axis direction with respect to the apparatus main body 2 while being guided by 43b.

  The dressing means 50a and 50b are disposed adjacent to the chuck table 10 in correspondence with the cutting means 20a and 20b. In this embodiment, the dressing means 50a and 50b are disposed in the apparatus main body 2 so as to face each other in the Y-axis direction with the chuck table 10 interposed therebetween. Yes. As shown in FIG. 2, the dressing means 50a and 50b are configured to include dresser boards 51a and 51b and holding means 52a and 52b, respectively.

  The dresser boards 51a and 51b have polishing surfaces 53a and 53b which are horizontal surfaces. The polishing surfaces 53a and 53b are ring-shaped. In this embodiment, the dresser boards 51a and 51b themselves including the polishing surfaces 53a and 53b are formed in a ring shape, and openings 54a and 54b are formed in the center. The dresser boards 51a and 51b are formed of a binding material in which abrasive grains such as white alundum and green carbon whose abrasive grain size is smaller than the abrasive grain size of the cutting blades 21a and 21b are bonded with a resin or the like.

  The holding means 52a and 52b hold the dresser boards 51a and 51b so that the polishing surfaces 53a and 53b are disposed on the side opposite to the side facing the holding means 52a and 52b. The holding means 52a and 52b hold the dresser boards 51a and 51b by suction from the back surface opposite to the polishing surfaces 53a and 53b. The portions constituting the surfaces of the holding means 52a and 52b (surfaces facing the dresser boards 51a and 51b) have a disk shape formed of porous ceramic or the like, and are connected to a vacuum suction source (not shown) via a vacuum suction path (not shown). It is connected. Further, as shown in FIG. 3, the holding means 52 a and 52 b are respectively supported by the apparatus main body 2 so as to be rotatable around a central axis B parallel to the Z axis. The holding means 52 a and 52 b are connected to a dress drive source (not shown) housed in the apparatus main body 2. The holding means stages 52a and 52b can be rotated at an arbitrary angle by the rotational force generated by the dress driving source (S shown in the figure), and the dresser boards 51a and 51b are centered on the cutting blades 21a and 21b. It can be driven to rotate at an arbitrary rotation angle around B.

  Here, in the dressing means 50a, 50b, the height H1 of the polishing surfaces 53a, 53b from the apparatus main body 2 in the state held by the holding means 52a, 52b is the height of the surface of the chuck table 10 from the apparatus main body 2. It is arranged to be the same as or lower than H2. That is, even when the cutting blades 21a and 21b are not in contact with the surface of the chuck table 10 and the cutting means 20a and 20b are moved in the Y-axis direction, the cutting blades 21a and 21b are held by the holding means 52a and 52b. There is no contact with the polishing surfaces 53a, 53b in the state of being. Therefore, even if the cutting means 20a and 20b move in the Y-axis direction in order to cut the workpiece W held on the chuck table 10, the dressing means 50a and 50b do not interfere with each other. As a result, the dressing means 50a and 50b can be disposed in the vicinity of the chuck table 10, so that the amount of movement in the Y-axis direction from the chuck table 10 to the dressing means 50a and 50b can be reduced, and after the cutting process. It is possible to shorten the time required to perform flat dressing and shift to cutting again (hereinafter simply referred to as “dressing time”).

  The dressing means 50a and 50b are disposed on a blade moving path, which is a path along which the cutting blades 21a and 21b move by the Y-axis moving means 30a and 30b. In the present embodiment, the dressing means 50a and 50b are arranged such that the central axis B is positioned on the rotation axis A of the spindles 22a and 22b, that is, the radial direction of the dresser boards 51a and 51b is parallel to the Y-axis direction. It is arranged. Accordingly, when the cutting means 20a and 20b are moved in the Z-axis direction closer to the dressing means 50a and 50b, the rotation axis A is parallel to the Z-axis direction on the outer periphery of the cutting blades 21a and 21b. The cutting blades 21a and 21b come into contact with the dresser boards 51a and 51b with reference to a point intersecting with a straight line passing through the top.

  The cassette elevator 60 has a plurality of storage portions in the Z-axis direction that store the workpieces W one by one, and stores a plurality of workpieces W at a time. The cassette elevator 60 is configured such that a space formed inside the apparatus body 2 can be raised and lowered in the Z-axis direction. The temporary placing means 70 has a pair of rails 71 and temporarily places the workpiece W before and after machining on the pair of rails 71. The cleaning / drying unit 80 includes a spinner table 81 on which the processed workpiece W is placed and held. The spinner table 81 is connected to a spinner table driving source housed in the apparatus main body 2. When the workpiece W is held on the spinner table 81, the cleaning / drying unit 80 rotates the workpiece W by the rotational force generated by the spinner table driving source, and the workpiece W is fed from a cleaning liquid ejecting apparatus (not shown). The cleaning is performed by spraying a cleaning liquid, and the workpiece W after cleaning is dried by spraying a gas from a gas spray device (not shown).

  The control means 90 controls each of the above-described components constituting the cutting device 1. The control means 90 causes the cutting device 1 to perform a machining operation on the workpiece W. Moreover, the control means 90 controls the flat dress with respect to the cutting means 20a, 20b by the dressing means 50a, 50b. The control means 90 is mainly composed of an arithmetic processing unit constituted by, for example, a CPU or the like and a microprocessor (not shown) provided with a ROM, a RAM, etc. It is connected to operating means used when registering content information and the like.

  Next, the machining operation of the cutting device 1 according to this embodiment will be described. First, when the operator registers the machining content information and receives an instruction to start the machining operation, the machining operation is started. In the processing operation, the workpiece W is unloaded from the cassette elevator 60 to the temporary placing means 70 by unillustrated unloading / unloading means, placed on the pair of rails 71 of the temporary placing means 70, and then conveyed by unillustrated conveying means. It is conveyed to the chuck table 10 and held on the chuck table 10. The chuck table 10 holding the workpiece W moves in the X-axis direction to the machining start position, cuts the outer circumference of the workpiece W in the circumferential direction, and removes a part of the outer circumference of the workpiece W ( Hereinafter, it is simply referred to as “removal processing”), or division processing for cutting a workpiece along a predetermined division line to make a plurality of devices, which will be described later, small pieces, is performed. In the case of removal processing, one or both of the cutting blades 21a and 21b are positioned on the outer periphery of the workpiece W, and one of the cutting blades 21a and 21b is rotated by rotating the workpiece W at that position. A part of the outer periphery of the workpiece W is cut in the Z-axis direction by the cutting blade and removed. In the case of division processing, one or both of the cutting blades 21a and 21b and one or both of the cutting blades 21a and 21b are changed along the planned division line while changing the relative positions of the workpiece W and the cutting blade 21a and 21b. The workpiece W is cut by 21a and 21b, and each device is divided into dice leaving the dicing tape T. The processed workpiece W is transported from the chuck table 10 to the cleaning / drying means 80 by a transport means (not shown), washed and dried by the cleaning / drying means 80, and then temporarily placed by a transport means (not shown). 70, and is carried into the cassette elevator 60 from the temporary placing means 70 by the carry-in / out means. In addition, since the cutting with respect to the workpiece W by the said cutting device 1 has the two cutting means 20a and 20b, the cutting means 20a and 20b are alternated for every 1 sheet or several sheets, or one cutting is carried out. After the blade reaches the limit of wear (including uneven wear), it may be replaced with the other cutting blade.

  Next, the flat dress of the cutting device 1 according to the present embodiment will be described. FIG. 4 is a diagram illustrating a flow of a flat dress by the cutting apparatus according to the embodiment. In addition, since the flat dress with respect to the cutting means 20a and 20b is the same, the case where a flat dress is performed with respect to the cutting means 20a is demonstrated here. Flat dressing with respect to the cutting blade 21a is performed by relatively moving the rotating cutting blade 21a and the dressing means 50a.

  First, the control means 90 determines whether or not it is necessary to perform a flat dress on the cutting means 20a (step ST1). Here, it is determined whether or not the partial wear on the cutting blade 21a has progressed and it is necessary to perform a flat dress on the cutting blade 21a by the dressing means 50a. Whether or not a flat dress is necessary is preferably determined based on the processing distance and the amount of wear with respect to the workpiece W that has been removed by the cutting means 20a. The processing distance and the amount of wear are the number of workpieces W that have been subjected to removal processing, the diameter of the workpiece W, the number and distance of lines to be divided with respect to the workpiece W, and the cutting amount of the cutting blade 21a. It is preferable to make a determination based on at least one such as the hardness of the cutting blade 21a.

  Next, when the control unit 90 determines that it is necessary to perform a flat dress on the cutting unit 20a (Yes in step ST1), the control unit 90 determines whether the cutting unit 20a is performing cutting (step ST2). If it is determined that it is not necessary to perform flat dressing on the cutting means 20a (No in step ST1), step ST1 is repeated until it is determined that flat dressing is necessary.

  Next, the control means 90 determines that cutting is not being performed by the cutting means 20a (No in step ST2), and executes a flat dress on the cutting means 20a (step ST3). Here, when the cutting means 20a that requires a flat dress is not currently cutting, for example, when the workpiece W is being processed by the cutting apparatus 1, the cutting means 20b is in the process of cutting and the cutting means 20b is cutting. A flat dress 20a is executed in a state where cutting is not being performed or in a state where the processing operation of the workpiece W by the cutting device 1 is not performed.

  In the flat dress with respect to the cutting means 20a, first, the control means 90 moves the cutting blade 21a which is not cutting and is positioned at the standby position to the predetermined cutting position by the Z-axis moving means 40a. Here, the predetermined cutting position is a position where the cutting blade 21a faces the dresser board 51a in the Y-axis direction, that is, the cutting blade 21a can contact the dresser board 51a in the Z-axis direction. Further, the predetermined cutting position is the cutting amount of the cutting blade 21a with respect to the dresser board 51a, the degree of uneven wear of the cutting blade 21a, the number of flat dresses with respect to the cutting blade 21a, that is, the number of contacts with the polishing surface 53a of the cutting blade 21a (for example, The number is increased when the flat dress is performed by one contact, and the number is decreased when the flat dress is performed by repeating a plurality of contacts).

  Next, the control means 90 moves the rotating cutting blade 21a from the predetermined cutting position in the Y-axis direction, here the direction in contact with the polishing surface 53a, by the Y-axis moving means. The cutting blade 21a moves in the Y-axis direction while rotating, thereby coming into contact with the polishing surface 53a, and the tip is shaped flat by the dresser board 51a. The control means 90 moves the rotating cutting blade 21a in the Y-axis direction until the cutting blade 21a and the polishing surface 53a are not in contact with each other. That is, the control means 90 moves at least the rotating cutting blade 21a from one end to the other end of the polishing surface 53a. Here, one end to the other end of the polishing surface 53a are radially opposed from the outer periphery of the dresser board 51a (C1 to C2 or C2 to C1 shown in FIG. 3), and are radially opposed from the outer periphery of the dresser board 51a. 3 includes an opening 54a (C1 to D1 or C2 to D2 shown in FIG. 3) and a radially outer periphery (D1 to C1 or D2 to C2 shown in FIG. 3) from the opening 54a of the dresser board 51a. Therefore, at the predetermined cutting position, the cutting blade 21a is located in the vicinity of the outer periphery of the dresser board 51a or in the opening 54a of the dresser board 51a as viewed in the Z-axis direction (viewed in the vertical direction in FIG. 3). In order to perform a flat dress, it moves in the Y-axis direction by at least the diameter or radius of the dresser board 51a. The control unit 90 rotates the cutting blade 21a while moving the cutting blade 21a in the Y-axis direction from the predetermined cutting position. The rotation starts before the cutting blade 21a moves to the predetermined cutting position or Either after moving. For example, after the cutting by the cutting means 21a, the rotation of the cutting blade 21a moved to the standby position may be moved directly to the predetermined cutting position without being stopped.

  Next, the control means 90 rotates the holding means 52a after the cutting blade 21a and the polishing surface 53a are not in contact with each other. Here, when the rotating cutting blade 21a is moved in the Y-axis direction with respect to the polishing surface 53a in contact, a linear cutting mark is formed on the polishing surface 53a. Of the polished surface 53a, an area where the cutting trace is formed (hereinafter simply referred to as “cutting trace area”) is a region where no cutting trace is formed (hereinafter simply referred to as “non-cutting trace area”). Since the cutting performance with respect to the cutting blade 21a is lowered, it is not preferable to use it again for the flat dress. Therefore, when the cutting blade 21a comes into contact with the polishing surface 53a again, the control means 90 makes the blade in the Z-axis direction (when FIG. 3 is viewed from below) in order to bring the cutting blade 21a into contact with the non-cutting mark region. The holding means 52a is rotated so that the non-cutting mark regions face each other on the movement path. The rotation angle may be a predetermined value, but the predetermined value is determined because the width of the cutting trace (the length in the direction orthogonal to the direction in which the cutting trace is formed in the horizontal plane) changes according to the predetermined cutting position. The rotation angle may be determined according to the cutting position. Further, the non-cutting mark region may include a part of the cutting mark region. For example, a cutting mark region may be included on the opening 54a side in the blade movement path in the Z-axis direction (when FIG. 3 is viewed from vertically below). In this case, the rotation angle of the dresser board 51a can be reduced, and compared with the case where the cutting trace region is not included in part on the blade movement path in the Z-axis direction (when FIG. 3 is viewed from vertically below). Thus, the dresser board 51a can be repeatedly used for a flat dress.

  As described above, in the cutting device 1 according to the present embodiment, the dresser boards 51a and 51b are rotatably arranged separately from the chuck table 10, and the cutting blades 21a and 21b are moved relative to the dresser boards 51a and 51b. By doing so, the flat dress of the cutting blades 21a and 21b is performed. Therefore, compared with the case where the workpiece W is removed from the chuck table to perform the flat dress and the dress board is held on the chuck table and the flat dress is performed, the operation for the operator or the conveying means to perform the flat dress is less. As a result, the work of the flat dress can be simplified.

  Further, the flat dress can be performed by using the time during which the workpiece W is not cut by the cutting blades 21a and 21b. For example, in the cutting apparatus 1, when one of the cutting blades 21a and 21b is cutting, the other dressing blade that is not cutting can be flat dressed. Further, in a cutting device having only one cutting blade, the processed workpiece W is removed from the chuck table 10 until the new workpiece W is held and cutting is possible. A flat dress can be performed. Therefore, even if the cutting of the workpiece W is not interrupted or is interrupted, the interruption time can be shortened, and productivity can be improved.

  In addition, since the polishing surfaces 53a and 53b of the dresser boards 51a and 51b are ring-shaped and can be rotated around the central axis B, the cutting blades 21a and 21b are moved in the Y-axis direction so that the polishing surfaces 53a and 53b are moved. Even if the cutting trace is formed, when the dresser boards 51a and 51b are rotated, the cutting blades 21a and 21b may come into contact with the non-cutting trace area when the cutting blades 21a and 21b are moved again in the Y-axis direction. it can. Therefore, by rotating the dresser boards 51a and 51b, the dresser boards 51a and 51b can be repeatedly used for a flat dress, so that productivity can be improved. When the polishing surface is disk-shaped, the cutting blade passes through the polishing surface on the central axis many times even if it is rotated around the central axis to repeat flat dressing. In order to make contact, the cutting blade is moved by the diameter. However, if the polishing surfaces 53a and 53b are ring-shaped, the cutting blades 21a and 21b are moved out of contact with the polishing surfaces 53a and 53b by moving the cutting blades 21a and 21b by a radius relative to the dresser boards 51a and 51b. This eliminates the need for flat dressing by moving the cutting blades 21a and 21b by the diameter. Even if the cutting blades 21a and 21b are moved by the diameter, the openings 54a and 54b are formed on the central axis B, so that the cutting blades 21a and 21b pass through the polishing surfaces 53a and 53b many times. Disappears. Therefore, the durability of the dresser boards 51a and 51b can be improved. Further, the blade movement path in the Z-axis direction (when FIG. 3 is viewed from below) without using a moving means for performing relative movement between the cutting means 20a, 20b and the workpiece W during the cutting process. A non-cutting mark region can be located on the top. Therefore, since the cutting of the workpiece W is not interrupted, productivity can be improved.

  In the above-described embodiment, the dresser boards 51a and 51b are configured as one ring-shaped member in which the polishing surfaces 53a and 53b are formed. However, the present invention is not limited to this, and the polishing surface 53a. , 53b and a base layer on which the dress layer is formed may be laminated. In this case, only the dress layer may be formed in a ring shape.

DESCRIPTION OF SYMBOLS 1 Cutting device 10 Chuck table 20a, 20b Cutting means 30a, 30b Y-axis moving means 40a, 40b Z-axis moving means 50a, 50b Dressing means 51a, 51b Dresser boards 52a, 52b Holding means 53a, 53b Polishing surfaces 54a, 54b Openings 60 Cassette elevator 70 Temporary placing means 80 Cleaning / drying means 90 Control means A Rotation axis B Center axis

Claims (3)

A chuck table that holds a workpiece on a surface that is a horizontal plane, a cutting means having a rotatable spindle and a cutting blade mounted on the spindle, and a Y axis that is parallel to the axis of rotation of the spindle. A cutting apparatus comprising: a Y-axis moving unit that moves in a direction; and a Z-axis moving unit that moves the spindle in a Z-axis direction that is a direction in which the spindle approaches and separates from the chuck table.
Dressing means disposed adjacent to the chuck table and disposed on the moving path of the cutting blade by the Y-axis moving means;
The dressing means includes a de Lesser board, holding the dresser board, and a rotatable holding means about the axis,
The cutting apparatus characterized in that the height of the polishing surface of the dresser board held by the holding means is the same as or lower than the height of the surface of the chuck table.   When dressing the cutting blade by the dressing means, the cutting blade is moved to a predetermined cutting position facing the dresser board in the Y-axis direction, and the cutting blade rotating from the predetermined cutting position is moved to the Y-axis moving means. After the cutting blade and the polishing surface are brought into non-contact with each other, the region of the polishing surface excluding the cutting traces is opposed to the moving path in the Z-axis direction. The cutting apparatus according to claim 1, wherein the holding means is rotated.   3. The cutting apparatus according to claim 1, wherein the dressing means is disposed so that the central axis is positioned on the rotation axis.

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