JP4154352B2 - Processing equipment - Google Patents

Description

  The present invention relates to a machining apparatus configured to move a chuck table that holds a workpiece.

  In various types of processing, processing may be performed by the action of processing elements while the workpiece is moving. For example, in a cutting apparatus that cuts a plate-like object such as a semiconductor wafer, the semiconductor wafer is held on a chuck table, and the chuck table moves, and a cutting blade that rotates at a high speed cuts into the moving semiconductor wafer. The street formed on is cut. Then, by cutting all streets vertically and horizontally, individual semiconductor chips are obtained.

  For example, the chuck table 70 in the cutting apparatus 7 shown in FIG. 4 includes a chuck plate 71 that holds a workpiece and a movable base 72 that can move while supporting the chuck plate 71. The threaded portion 73 is screwed to the ball screw 74, and the chuck table 70 moves in the axial direction of the ball screw 74 while being guided by the guide rail 75 as the ball screw 74 rotates ( For example, see Patent Document 1).

JP 2002-66866 A

  However, since the ball screw 74 is screwed into the screwed portion 73 of the moving base 72 constituting the chuck table 70, the chuck table 70 will swing if there is even a slight distortion in the axis of the ball screw 74. As a result, the workpiece held on the chuck plate 71 of the chuck table 70 also oscillates, so that the cutting position of the cutting blade with respect to the workpiece may meander or the cutting depth may not be uniform. is there.

  Further, in order to prevent the cutting water and cutting chips from adhering to the ball screw 74 and the like, the bellows 76 are usually connected to both sides in the moving direction of the chuck table 70, so that an external force due to expansion and contraction of the bellows 76 is applied to the chuck table. There is also a problem that the chuck table 70 is oscillated by being transmitted to 70 and the machining accuracy is lowered.

  Therefore, a problem to be solved by the present invention is to enable high-accuracy machining by appropriately moving the chuck table in a machining apparatus configured to hold and move the workpiece.

The present invention is a processing apparatus including at least a chuck table that holds a workpiece, a processing unit that processes the workpiece held on the chuck table, and a driving unit that drives the chuck table to process and feed the workpiece. The chuck table includes at least a chuck plate that supports a workpiece and a movable base that is movable while supporting the chuck plate, and the driving means includes a guide portion that supports the movable base in a movable manner. A frame having a spherical moving base support portion that is supported movably by the guide portion and surrounds the moving base and supports only the moving direction of the moving base in a point contact state ; and It includes at least a formed screwed portion, a ball screw screwed into the screwed portion, and a drive source for rotating the ball screw, and a bellows covering the guide portion is connected to an end portion in the moving direction of the frame body. ing And it is characterized in and.

  Examples of the processing means include a cutting means provided with a rotatable spindle, a cutting blade mounted on the spindle and rotatable, and a nozzle for supplying cutting water to the work piece. It is not limited. For example, a means for cutting with laser light is included.

In the present invention, only the moving direction of the moving base is supported in a point contact state by the spherical moving base supporting part constituting the frame surrounding the moving base, and the screwed part formed on the frame The movement base is controlled by the movement base support portion in the movement direction, and has a degree of freedom in directions other than the supported direction. It has become. Therefore, if the ball screw shaft is distorted, the moving base support part absorbs the distortion in the direction not supported by the moving base support part even if the frame swings due to the distortion. However, since the moving base does not swing, the chuck plate supported by the moving base also does not swing, and the processing means acts on the workpiece held on the chuck plate while meandering and moving up and down. There is no such thing, and processing accuracy can be raised.

In addition, by connecting the bellows that cover the guide portion to the end of the frame in the moving direction, even if external force due to expansion and contraction of the bellows is transmitted to the frame, it is not transmitted to the chuck plate. Since the processing means does not act on the workpiece held on the chuck plate while meandering or moving up and down, the processing accuracy can be improved in this respect as well.

  When the processing means is a cutting means including a spindle, a cutting blade, and a nozzle, the cutting blade meanders and does not act on the workpiece, so that the cutting accuracy is improved.

  The cutting apparatus 1 shown in FIG. 1 shows an example of the processing apparatus of the present invention. The chuck table 2 is driven by the driving means 3 in the X-axis direction, and the cutting means 4 as the processing means is Y. The direction driving means 5 is indexed and fed in the Y-axis direction, and the Z direction driving means 6 is cut and fed in the Z-axis direction.

  The chuck table 2 includes at least a chuck plate 20 that holds a workpiece and a movable base 21 that supports and can move the chuck plate 20. The illustrated chuck table 2 also includes a clamp portion 22 that clamps and fixes the outer peripheral portion of the workpiece held by the chuck plate 20.

  The driving unit 3 includes a guide unit 30 that supports the moving base 21 so as to be movable, a frame 31 that is supported by the guide unit 30 so as to be movable, surrounds the moving base 21, and supports at least the moving direction. A screwed portion 32 formed in the frame 31, a ball screw 33 screwed into the screwed portion, and a drive source 34 that rotates the ball screw 33 are provided. Bellows 35 are connected to both ends in the moving direction of the frame 31 as an elastic member that covers the guide portion 30.

  The cutting means 4 includes a spindle 41 that is rotatably supported by a spindle housing 40, a cutting blade 42 that is mounted on the spindle 41 and is rotatable, and a nozzle 43 that supplies cutting water to the workpiece. Yes. After the nozzle 43 flows out, the used cutting water is stored in the cutting water receiving portion 44 and then drained from the drainage portion 45.

  The Y-direction drive means 5 includes a ball screw 50 disposed in the Y-axis direction, a drive source 51 that rotates the ball screw 50, a guide rail 52 disposed in the Y-axis direction, and a nut that is screwed into the ball screw 50. And a moving member 53 slidably engaged with the guide rail 52.

  The Z direction driving means 6 includes a ball screw (not shown) disposed in the Z axis direction in the moving member 53, a drive source 60 for rotating the ball screw, and a guide rail 61 disposed in the Z axis direction. And a support portion 62 that includes a nut that is screwed into the ball screw and is slidably engaged with the guide rail 61 and supports the cutting means 4.

  The workpiece W to be cut is held on the chuck plate 20. Then, after the cutting means 4 is moved in the Y-axis direction by the Y-direction driving means 5, the position of the workpiece W to be cut and the cutting blade 42 are aligned in the Y-axis direction, and then the driving means 3, the chuck plate 20 is driven together with the movable base 21 to move the workpiece W in the X-axis direction, and the cutting means 4 is driven and lowered by the Z-direction driving means 5 while the cutting blade 42 rotates at high speed. As a result, the cutting blade 42 that rotates at a high speed to a desired position of the workpiece W cuts and performs cutting. For example, when the workpiece W is a semiconductor wafer, the street is cut.

  Since the threaded portion 32 formed on the frame 31 is screwed to the ball screw 33, when the chuck table 2 is driven by the driving means 3, the ball screw 33 is driven by the driving source 34 shown in FIG. When rotating, the frame body 31 moves in the X-axis direction while being guided by the guide portion 30, and the bellows 35 expands and contracts accordingly.

  As shown in FIG. 2, the frame 31 supports at least the moving direction of the moving base 21 by the moving base support portion 36. The movable base support part 36 is formed in a spherical shape in the illustrated example. When the moving base support 36 is formed in a spherical shape, only the X-axis direction of the moving base 21 is supported in a point contact state, and the Y-axis direction and the Z-axis direction have a degree of freedom. It has become.

  When the ball screw 33 rotates, the entire chuck table 2 including the moving base 21 moves in the X-axis direction as the frame body 31 moves in the X-axis direction. At this time, if the ball screw 33 is distorted, the frame body 31 swings accordingly. However, since the moving base 21 is supported only by the moving base support part 36 in its moving direction, the moving base support part In directions not supported by 36 (Y-axis direction, Z-axis direction), the movable base support portion 36 absorbs the distortion, and the movable base 21 does not swing. Accordingly, the chuck plate 20 supported by the movable base 21 does not swing, and the cutting means 4 does not act on the workpiece held on the chuck plate 20 while meandering or moving up and down. Can be cut with high accuracy. When the workpiece is a semiconductor wafer, the street is cut with high accuracy, and the quality of the semiconductor chip can be improved without damaging the circuit formed on the semiconductor chip.

  In addition, since the bellows 35 is connected to the end of the frame 31, when the bellows 35 expands and contracts with the movement of the chuck table 2, an external force from the bellows 35 is transmitted to the frame 31. Since the moving base 21 is in a state in which at least the moving direction is supported by the moving base support portion 36 constituting the frame 31, among the external forces, the external forces in the Y-axis direction and the Z-axis direction are applied to the chuck table 2. In this respect, the chuck table 2 can be prevented from swinging, which contributes to improvement of machining accuracy.

  In the example of FIG. 2, the case where the movable base support portion 36 is formed in a spherical shape has been described as an example, but it may be formed in a cylindrical shape, for example. In this case, the movable base 21 is supported by the side surface of the cylinder. For example, as shown in FIG. 3, when the columnar moving base support portion 36a is erected, that is, when the column axis is oriented in the Z-axis direction, In the state of line contact, in addition to the X-axis direction that is the moving direction of the moving base 21, the Z-axis direction is also supported. In this case, even if the ball screw 33 is distorted in the Y-axis direction and the frame body 31 is oscillated in the Y-axis direction, the oscillation is not transmitted to the moving base 21. Therefore, the chuck table 2 can be prevented from swinging in the Y-axis direction, and the cutting means 4 can be prevented from meandering in the Y-axis direction and acting on the workpiece. In addition, you may comprise the movement base support part 36 by an air bearing.

  As for the external force from the bellows 35, the external force in the Y-axis direction is not transmitted to the chuck table 2, so that the chuck table 2 does not swing in the Y-axis direction, and the cutting means 4 is in the Y-axis direction. Can be prevented from meandering and acting.

  INDUSTRIAL APPLICABILITY The present invention can be used for a machining apparatus that requires precise machining because it can feed the workpiece without swinging the chuck table that holds the workpiece.

It is a perspective view which shows the cutting device as an example of a processing apparatus. It is a schematic sectional drawing which shows the 1st example of the support mechanism of a chuck table. It is a schematic sectional drawing which shows the 2nd example of the support mechanism of a chuck table. It is a schematic sectional drawing which shows the support mechanism of the conventional chuck table.

Explanation of symbols

1: Cutting device 2: Chuck table 20: Chuck plate 21: Moving base 22: Clamping unit 3: Driving means 30: Guide unit 31: Frame body 32: Screwed portion 33: Ball screw 34: Driving source 35: Bellows 36 : Moving base support part 4: Cutting means 40: Spindle housing 41: Spindle 42: Cutting blade 43: Nozzle 44: Cutting water receiving part 45: Drainage part 5: Y direction driving means 50: Ball screw 51: Driving source 52: Guide Rail 53: Moving member 6: Z direction drive means 60: Drive source 61: Guide rail 62: Support part

Claims (2)

A processing apparatus comprising at least a chuck table for holding a workpiece, a processing means for processing the workpiece held on the chuck table, and a driving means for driving the chuck table to be processed,
The chuck table includes at least a chuck plate that supports a workpiece, and a movable base that is movable while supporting the chuck plate,
The driving means includes a guide unit that supports the movable base so as to be movable, and is supported by the guide unit so as to be movable, and surrounds the movable base so that only the moving direction of the movable base is point-contacted. A frame having a spherical moving base support portion to be supported in a state, a screwed portion formed in the frame, a ball screw screwed into the screwed portion, and a drive for rotating the ball screw comprising at least a source,
A processing apparatus, wherein a bellows covering the guide portion is connected to an end portion of the frame body in the moving direction . The said processing means is a cutting means provided with a rotatable spindle, a cutting blade mounted on the spindle and rotatable, and a nozzle for supplying cutting water to the workpiece. Processing equipment.

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