JP2011082402A - Cutting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cutting device with a simple structure in which the position of a blade detection sensor does not fluctuate.
A chuck table for sucking and holding a workpiece, a cutting means having a spindle for rotatably supporting a cutting blade for cutting the workpiece sucked and held by the chuck table, and a cutting direction of the cutting blade A cutting device provided with a blade detecting means for detecting a position, wherein the chuck table is disposed on a table base provided movably in a direction orthogonal to the spindle of the cutting means; The detection means is mounted on a vertical support member standing from the table base, a horizontal support member extending so as to protrude from the vertical support member to the side of the chuck table, and a front end portion of the horizontal support member It comprises a blade detection mechanism having at least a light emitting part and a light receiving part. During the operation of the cutting device, water is always supplied into the water storage groove.
[Selection] Figure 4

Description

  The present invention generally relates to a cutting device, and more particularly to a configuration of a blade detection unit for detecting a reference position in a cutting direction of a cutting blade of the cutting device and a replacement time of the cutting blade.

  A semiconductor wafer or the like is cut by a cutting device generally called a dicing device. The dicing apparatus cuts a workpiece such as a semiconductor wafer with a rotating cutting blade. This cutting blade is worn away by use and its diameter decreases.

  For this reason, the dicing apparatus needs to adjust the reference position in the cutting direction of the cutting blade in response to a decrease in the diameter of the cutting blade, and includes a blade detection mechanism for detecting the reference position (for example, a special feature). No. 2001-298001).

  Such a blade detection mechanism is mounted on a table base on which a chuck table is mounted. Since the chuck table can handle workpieces that are larger than the table base so that the workpiece can be as large as possible, the blade detection mechanism has a blade detection sensor located outside the larger chuck table. In order to do so, it is mounted on the end of a horizontal support member extending laterally from the table base.

  Such a blade detection mechanism is used in combination with an origin position detection mechanism that detects the origin position of the cutting blade by cutting the cutting blade into the frame of the chuck table made of metal and conducting it.

  The origin position of the cutting blade detected by this origin position detection mechanism is to cut a workpiece such as a wafer, so that the cutting blade is lowered to cut only the workpiece and not to the chuck table. It becomes a standard to set up. In the origin position detection mechanism, since the cutting blade cuts into the upper surface of the frame body of the chuck table, the upper surface of the frame body is damaged, and it is not a good idea to frequently detect the origin position with the origin position detection mechanism.

  Therefore, a blade detection mechanism is provided in the vicinity of the chuck table in addition to the origin position detection mechanism, and the blade detection mechanism detects the position of the blade edge in the cutting direction, and detects the chuck table holding surface position and the blade detection mechanism. The origin position of the cutting blade is detected by correcting the difference in the height direction (cutting direction) from the position.

JP 2001-298001 A

  However, the horizontal support member that supports the blade detection sensor including the light emitting unit and the light receiving unit of the blade detection mechanism has a structure in which water droplets and sprays of cutting water used for cutting are irregularly applied.

  For this reason, water applied to the horizontal support member may be vaporized, and as a result, the metal horizontal support member contracts due to cooling by the heat of vaporization, causing a problem that the position of the sensor fluctuates.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a cutting device having a simple structure and in which the position of the blade detection sensor does not fluctuate.

  According to the present invention, a chuck table for sucking and holding a workpiece, a cutting means having a spindle for rotatably supporting a cutting blade for cutting the workpiece sucked and held by the chuck table, and the cutting of the cutting blade A cutting device provided with a blade detection means for detecting a directional position, wherein the chuck table is disposed on a table base provided movably in a direction perpendicular to the spindle of the cutting means, The blade detection means is mounted on a vertical support member standing from the table base, a horizontal support member extending so as to protrude from the vertical support member to the side of the chuck table, and a front end portion of the horizontal support member. Further, it is composed of a blade detection mechanism having at least a light emitting part and a light receiving part, and a water retaining groove is formed on the entire upper surface of the horizontal support member, During operation of the cutting device cutting apparatus characterized by always water in the water Tamarimizo is supplied it is provided.

  Preferably, the blade detection mechanism includes a cleaning water supply nozzle that supplies cleaning water to the light emitting unit and the light receiving unit, and the cleaning water supplied from the cleaning water supply nozzle to the light emitting unit and the light receiving unit. Is configured to flow into the water retaining groove formed in the horizontal support member.

  According to the present invention, the water retaining groove is formed on the upper surface of the horizontal support member, and since water is constantly supplied into the water retaining groove, the water in the water retaining groove may be vaporized. The influence of vaporization heat can be avoided. As a result, the problem that the position of the blade detection sensor fluctuates can be solved.

  In addition, the blade detection means moves to the left and right at high speed, similar to the chuck table, so that the water in the water ditch will easily flow down, but the water that accumulates in the water ditch will use the wash water that is constantly supplied to the blade detection sensor. Since a diverting mechanism is employed, water can be always supplied into the water reservoir.

It is a perspective view of a cutting device. It is a surface side perspective view of the semiconductor wafer supported by the annular frame via the dicing tape. It is a partial cross section side view of a blade detection means and a chuck table part. It is a perspective view of the principal part of a blade detection means. It is a block diagram of a blade detection mechanism. It is a graph which shows the change of the output voltage of a blade detection mechanism according to the position of the cutting direction of a cutting blade.

  Hereinafter, a cutting device 2 according to an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a schematic configuration diagram of the cutting device 2. The cutting device 2 includes a pair of guide rails 6 that are mounted on the stationary base 4 and extend in the X-axis direction.

  Reference numeral 8 denotes a table base (X-axis movement block). The table base 8 is moved in the machining feed direction, that is, the X-axis direction by an X-axis feed mechanism 14 including a ball screw 10 and a pulse motor 12. A chuck table 20 is mounted on the table base 8 via a cylindrical support member 22. A motor for rotating the chuck table 20 is accommodated in the cylindrical support member 22.

  The chuck table 20 has a suction part (suction chuck) 24 formed of porous ceramics and the like, and a frame 23 formed of metal such as SUS surrounding the suction chuck 24. The suction surface of the suction portion 24 and the upper surface of the frame body 23 are formed flush with each other. The chuck table 20 is provided with a plurality (four in this embodiment) of clampers 26 that clamp the annular frame F shown in FIG. Reference numeral 25 denotes a waterproof cover.

  As shown in FIG. 2, the first street S1 and the second street S2 are formed orthogonal to each other on the surface of the semiconductor wafer W to be processed by the cutting apparatus 2, and the first street S1 A device D is formed in each of the areas partitioned by the second street S2.

  The wafer W is attached to a dicing tape T that is an adhesive tape, and the outer periphery of the dicing tape T is attached to an annular frame F. As a result, the wafer W is supported by the annular frame F via the dicing tape T, and is clamped on the chuck table 20 by clamping the annular frame F by the clamper 26 shown in FIG.

  The X-axis feed mechanism 14 includes a linear scale 16 disposed on the stationary base 4 along the guide rail 6 and a reading head 18 disposed on the lower surface of the table base 8 that reads the X coordinate value of the linear scale 16. Including. The read head 18 is connected to the controller of the cutting device 2.

  A pair of guide rails 28 extending in the Y-axis direction are further fixed on the stationary base 4. The Y-axis moving block 30 is moved in the Y-axis direction by a Y-axis feed mechanism (index feed mechanism) 36 composed of a ball screw 32 and a pulse motor 34.

  Although not particularly illustrated, the Y-axis feed mechanism 36 is arranged on the linear scale disposed on the stationary base 4 along the guide rail 28 and the lower surface of the Y-axis moving block 30 that reads the Y coordinate value of the linear scale. The reading head is provided, and the reading head is connected to the controller of the cutting device 2.

  The Y-axis moving block 30 is formed with a pair of guide rails 38 (only one is shown) extending in the Z-axis direction. The Z-axis moving block 40 is moved in the Z-axis direction by a Z-axis feed mechanism 44 including a ball screw (not shown) and a pulse motor 42.

  Although not specifically illustrated, the Z-axis feed mechanism 44 is disposed on the linear scale disposed on the Y-axis movement block 30 along the guide rail 38 and the Z-axis movement block 40 that reads the Z coordinate value of the linear scale. The read head is connected to the controller of the cutting device 2.

  Reference numeral 46 denotes a cutting unit (cutting means), and a spindle housing 48 of the cutting unit 46 is inserted into and supported by the Z-axis moving block 40. A spindle 49 (see FIG. 5) is accommodated in the spindle housing 48 and is rotatably supported by an air bearing. The spindle 49 is rotationally driven by a motor (not shown) housed in a spindle housing 48, and a cutting blade 50 is detachably attached to the tip of the spindle 49.

  An alignment unit (alignment means) 52 is mounted on the spindle housing 48. The alignment unit 52 has an image pickup unit (image pickup means) 54 for picking up an image of the wafer W held on the chuck table 20. The cutting blade 50 and the imaging unit 54 are arranged in alignment in the X-axis direction.

  As shown in FIGS. 3 and 4, the blade detection means 56 for detecting the reference position in the cutting direction of the cutting blade 50 is a vertical support member 78 erected from the table base 8 and a vertical support member fixed to the vertical support member 78. The horizontal support member 72 extends so as to protrude from the member 78 to the side of the chuck table 20, and the blade detection mechanism 58 mounted at the tip of the horizontal support member 72.

  As best shown in FIG. 4, the horizontal support member 72 is secured to the vertical support member 78 by a plurality of screws 76. The horizontal support member 72 has a water reservoir groove 74 for storing water on the entire surface thereof. The water reservoir groove 74 has an outlet 75 through which water stored in the groove 74 flows out.

  As shown in FIG. 3, the waterproof cover 25 is fixed to the vertical support member 78 by a plurality of screws 77. In FIG. 4, the waterproof cover 25 is omitted. A packing 27 is disposed between the cylindrical support member 22 of the chuck table 20 and the waterproof cover 25. Reference numeral 80 denotes a bellows, which is omitted in FIG.

  The blade detection mechanism 58 includes an attachment member 60 having a horizontal portion 60a and a vertical portion 60b. The front end of the vertical portion 60 b of the attachment member 60 is formed in a U shape that defines the blade intrusion portion 62, and the light emitting portion 64 and the light receiving portion 66 that receives light from the light emitting portion 64 across the blade intrusion portion 62. Is arranged. As shown in FIG. 5, the light emitting unit 64 is connected to the light source 82 via the optical fiber 81, and the light receiving unit 66 is connected to the photoelectric conversion unit 84 via the optical fiber 83.

  In the horizontal portion 60 a of the mounting member 60, cleaning water supply nozzles 68 a and 68 b that supply constant temperature-controlled cleaning water to the end surfaces of the light emitting unit 64 and the light receiving unit 66, and air are supplied to the end surfaces of the light emitting unit 64 and the light receiving unit 66. Air supply nozzles 70a and 70b to be supplied are disposed.

  Here, it should be noted that the U-shaped bottom surface 65 that defines the blade entry portion 62 is formed to be inclined in the direction of the cleaning water supply nozzles 68a and 68b. Therefore, the water supplied from the cleaning water supply nozzles 68 a and 68 b and flowing down upon hitting the light emitting portion 64 and the light receiving portion 66 travels along the inclined bottom surface 65 and flows into the water reservoir groove 74 of the horizontal support member 72, and ends of the water reservoir groove 74. It is formed so as to flow out of 75.

  Next, the cutting blade 50 is cut into the frame 23 of the chuck table 20 made of metal to establish conduction, thereby detecting the origin position detection mechanism for detecting the origin position of the cutting blade 50 and the reference position of the cutting blade 50. The operation of the blade detection mechanism 58 of the present invention will be described.

  When a new chuck table 20 is mounted or when the chuck table 20 is disassembled and reassembled after cleaning, the cutting blade 50 is first cut into the frame 23 of the chuck table 20 by the origin position detection mechanism. Then, the origin position of the cutting blade 50 is detected, and this origin position is stored in the memory of the controller of the cutting apparatus 2.

  Next, reference position detection for detecting the reference position in the cutting direction of the cutting edge of the cutting blade 50 by the blade detection mechanism 56 is performed. This reference position detection will be described with reference to FIG. The light from the light source 82 is conveyed by the optical fiber 81 and emitted from the light emitting unit 64 in the form of a beam. The light receiving unit 66 receives the light emitted by the light emitting unit 64 and sends the received light to the photoelectric conversion unit 84 via the optical fiber 83.

  The photoelectric conversion unit 84 outputs a voltage corresponding to the amount of light transmitted from the light receiving unit 66 to the voltage comparison unit 88. On the other hand, a reference voltage (for example, 3 V) set by the reference voltage setting unit 86 is input to the voltage comparison unit 88.

  The voltage comparison unit 88 compares the output from the photoelectric conversion unit 84 with the reference voltage set by the reference voltage setting unit 86, and when the output from the photoelectric conversion unit 84 reaches the reference voltage, a signal indicating that is given. Output to the reference position detector 90.

  More specifically, when the reference position in the cutting direction of the cutting blade 50 is detected, the pulse motor 42 of the Z-axis feed mechanism 44 is driven so that the cutting blade 50 is moved above the blade entry portion 62 of the blade detection mechanism 58. Let's invade from.

  At this time, when the cutting blade 50 does not block between the light emitting unit 64 and the light receiving unit 66, the light amount received by the light receiving unit 66 is the maximum, and the output from the photoelectric conversion unit 84 corresponding to this light amount is, for example, As shown in FIG. 6, it is set to 5V.

  As the cutting blade 50 enters the blade intrusion portion 62, the amount by which the cutting blade 50 blocks the light beam emitted from the light emitting portion 64 gradually increases, so the amount of light received by the light receiving portion 66 gradually decreases. The output voltage from the photoelectric conversion unit 84 gradually decreases as indicated by reference numeral 92 in FIG.

  And when the cutting blade 50 reaches the position which connects the center of the light emission part 64 and the light-receiving part 66, it sets so that the output voltage from the photoelectric conversion part 84 may be set to 3V, for example. Therefore, when the output voltage of the photoelectric conversion unit 84 reaches 3V, the voltage comparison unit 88 outputs a signal indicating that the output voltage of the photoelectric conversion unit 84 has reached the reference voltage to the reference position detection unit 90.

  The reference position detection unit 90 transmits a signal indicating that the reference position has been detected to the pulse motor 42 and stops driving the pulse motor 42. At this time, the reference position detection unit 90 stores the value of the linear scale that detects the position of the cutting blade 50 in the cutting direction (Z-axis direction) as the reference position.

  As shown in FIG. 3, there is a difference in a predetermined height direction (cutting direction) between the holding surface position of the suction portion 24 of the chuck table 20 and the reference position of the cutting blade 50 detected by the blade detection mechanism 58. Exists.

  Therefore, since the origin position of the cutting blade 50 detected by the origin position detection mechanism and the reference position of the cutting blade 50 detected by the blade detection mechanism 58 are both stored in the memory, the reference position detected by the blade detection mechanism 58 is used as the reference position. By correcting by the difference between the origin position and the reference position, the origin position where the cutting blade 50 contacts the upper surface of the frame body 23 of the chuck table 20 can be detected based on the reference position detected by the blade detection mechanism 58.

  In FIG. 3, an arrow P indicates a case where the cutting blade 50 is performing the reference position detection operation, and an arrow Q indicates a case where the cutting blade 50 is performing the cutting operation of the wafer W. In both the reference position detection operation and the cutting operation, the cutting blade 50 is rotated in the direction of arrow A at a high speed (for example, 30000 rpm).

  Since the difference between the origin position of the cutting blade 50 and the reference position of the cutting blade 50 detected by the blade detection mechanism 58 varies due to an assembly error of the cutting device, the difference is obtained for each cutting device and stored in the memory. The

  Therefore, when it becomes necessary to re-detect the origin position of the cutting blade 50 during normal cutting, the blade detection mechanism 58 detects the reference position of the cutting blade 50, and this reference position is stored in advance. The original position of the cutting blade 50 is corrected by the correction value.

  Accordingly, it is possible to minimize the necessity of cutting the top surface of the frame body 23 of the chuck table 20 with the cutting blade 50 to detect the origin position, and it is possible to suppress damage to the top surface of the frame body 23.

  By the way, during the cutting process of the wafer W, the cutting water is always supplied to the cutting blade 50 to perform the cutting process, and the light emitting part 64 and the light receiving part 66 of the blade detection mechanism 58 are supplied from the cleaning water jet nozzles 68a and 68b. Wash water is always supplied. When cutting is stopped and the power of the apparatus is turned off, the supply of cutting water and the supply of cleaning water are stopped.

  Conventionally, since the upper surface of the horizontal support member is flat and no water groove is formed, the water applied to the horizontal support member is vaporized during the rest of the cutting device, and the metal horizontal support member is cooled by the heat of vaporization due to the influence. As a result, the blade contracts and the position of the blade detection sensor fluctuates.

  According to the blade detection means 56 of the present embodiment, the water retaining groove 74 is formed on the upper surface of the horizontal support member 72, and the horizontal support member 72 is always covered with water, so that some water in the water retaining groove 74 is present. Even if vaporization occurs, the influence of the heat of vaporization can be avoided by the water stored in the water storage groove 74. As a result, the problem that the position of the blade detection sensor fluctuates due to the horizontal support member 72 contracting due to the heat of vaporization can be solved.

  In the present embodiment, the cutting water supplied during the cutting process flows down from the chuck table 20 and is supplied into the water retaining groove 74 of the horizontal support member 72, and the light emitting unit 64 and the cleaning water supply nozzles 68 a and 68 b. The constant temperature adjusted cleaning water supplied to the light receiving portion 66 flows down, is guided by the inclined bottom surface 65, and is supplied into the water retaining groove 74 of the horizontal support member 72.

  As described above, since the water supplied into the water reservoir groove 74 employs a mechanism that diverts the water that is constantly supplied to the blade detection sensor, water at a constant temperature is always supplied into the water reservoir groove 74. be able to. A part of a pipe for supplying cleaning water to the cleaning water supply nozzles 68 a and 68 b may be branched to inject water directly into the water reservoir groove 74.

  The blade detection mechanism 58 of the present embodiment detects not only the reference position of the cutting blade 50 but also the tip of the cutting blade descends gradually when the cutting blade 50 is worn. It can also be used to detect 50 replacement times.

2 Cutting device 8 Table base 20 Chuck table 50 Cutting blade 56 Blade detection means 58 Blade detection mechanism 62 Blade entry portion 64 Light emitting portion 66 Light receiving portions 68a and 68b Washing water supply nozzles 70a and 70b Air supply nozzle 72 Horizontal support member 74 Water retaining groove

Claims (2)

A chuck table for sucking and holding a workpiece, a cutting means having a spindle for rotatably supporting a cutting blade for cutting the workpiece sucked and held by the chuck table, and a cutting direction position of the cutting blade is detected. A cutting device comprising blade detection means,
The chuck table is disposed on a table base provided movably in a direction orthogonal to the spindle of the cutting means,
The blade detection means is mounted on a vertical support member standing from the table base, a horizontal support member extending so as to protrude from the vertical support member to the side of the chuck table, and a tip of the horizontal support member A blade detection mechanism having at least a light emitting portion and a light receiving portion,
A water cutting groove is formed on the entire upper surface of the horizontal support member, and water is always supplied into the water collecting groove during operation of the cutting apparatus.   The blade detection mechanism includes a cleaning water supply nozzle that supplies cleaning water to the light emitting unit and the light receiving unit, and the cleaning water supplied from the cleaning water supply nozzle to the light emitting unit and the light receiving unit is in the horizontal direction. The cutting apparatus according to claim 1, wherein the cutting apparatus is configured to flow into the water accumulation groove formed in the support member.

Images