JP6498020B2 - Cleaning method of chuck table - Google Patents

Description

  The present invention relates to a method for cleaning a chuck table provided in a cutting apparatus.

  When dividing a semiconductor wafer, a package substrate, etc. into a plurality of chips, for example, a cutting device provided with a cutting blade is used (for example, refer to patent documents 1). The cutting apparatus includes a chuck table that sucks and holds a workpiece using negative pressure, and the workpiece is cut while being held by the chuck table.

  By the way, the workpiece as described above is held on the chuck table in a state of a frame unit in which a large-diameter dicing tape is attached to the front or back surface and an annular frame is fixed to the outer peripheral portion of the dicing tape. There are many cases. In this case, since the holding surface of the chuck table that holds the workpiece is covered with a dicing tape or the like, there is a low possibility that foreign matters such as end materials will get on the holding surface when the workpiece is cut.

JP 2003-234308 A

  However, for example, if the workpiece is cut out and then removed from the chuck table and cleaned by an adjacent cleaning unit or the like, there is a possibility that the end material or the like scattered by the cleaning gets on the holding surface of the chuck table. If such a foreign substance gets on a holding surface, it will cause damage to a workpiece or a cutting blade, which is a problem.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a chuck table cleaning method capable of appropriately removing foreign matters on a holding surface.

According to the present invention, there is provided a chuck table having a holding surface that can be selectively connected to a suction source and a fluid supply source, and sucking and holding a workpiece by the holding surface, and a work piece held on the chuck table. A cutting means for cutting an object, a chuck table moving means for moving the chuck table in a cutting feed direction, and a nozzle that is disposed across the movement path of the chuck table and ejects fluid toward the holding surface. A chuck table cleaning method used when cleaning the chuck table of a cutting apparatus, wherein the holding surface is connected to the fluid supply source to eject fluid from the holding surface and downward from the nozzle. A chuck table, wherein the chuck table is moved so as to pass under the nozzle in a state where a fluid is ejected, and foreign matters on the holding surface are removed. Cleaning method is provided.

  In the chuck table cleaning method according to the present invention, since the fluid is ejected from the chuck table holding surface and the fluid is ejected from the nozzle, the chuck table is moved so as to pass under the nozzle. The foreign matter on the top is easily lifted by the fluid ejected from the holding surface, and is blown off to the outside of the retaining surface by the fluid ejected from the nozzle. Thereby, the foreign material on a holding surface can be removed appropriately.

It is a perspective view which shows a cutting device typically. FIG. 2A is a partial cross-sectional side view schematically showing how the workpiece is carried out of the chuck table, and FIG. 2B shows the chuck table after the workpiece is carried out. It is a partial section side view showing typically. 3A and 3B are partial cross-sectional side views schematically showing a chuck table cleaning method according to the present embodiment.

  Embodiments of the present invention will be described with reference to the accompanying drawings. First, a cutting apparatus in which the chuck table cleaning method according to the present embodiment is used will be described. FIG. 1 is a perspective view schematically showing a cutting apparatus according to the present embodiment.

  As shown in FIG. 1, the cutting device 2 includes a base 4 that supports each structure. A cassette elevator 6 is provided at the front corner of the base 4. A cassette 8 capable of accommodating a plurality of workpieces 11 is placed on the upper surface of the cassette elevator 6. The cassette elevator 6 is configured to be movable up and down, and adjusts the height of the cassette 8 (position in the Z-axis direction) so that the workpiece 11 can be appropriately carried out and carried in.

  The workpiece 11 is, for example, a circular wafer made of a semiconductor material such as silicon, and the surface side thereof is divided into a central device region and an outer peripheral surplus region surrounding the device region. The device region is further divided into a plurality of regions by division lines (streets) arranged in a lattice pattern, and devices such as ICs and LSIs are formed in each region.

  A dicing tape 13 having a diameter larger than that of the workpiece 11 is attached to the back surface side of the workpiece 11. An outer peripheral portion of the dicing tape 13 is fixed to an annular frame 15. That is, the workpiece 11 is supported on the frame 15 via the dicing tape 13.

  In the present embodiment, a circular wafer made of a semiconductor material such as silicon is used as the workpiece 11. However, the material, shape, and the like of the workpiece 11 are not limited. For example, a plate-like object such as a ceramic substrate, a resin substrate, or a metal substrate made of a material such as sapphire can be used as the workpiece 11.

  A rectangular opening 4 a that is long in the X-axis direction (front-rear direction, cutting feed direction) is formed on the side of the cassette elevator 6. In this opening 4a, an X-axis moving table 10, an X-axis moving mechanism (chuck table moving means) (not shown) for moving the X-axis moving table 10 in the X-axis direction, and a dustproof and splashproof covering the X-axis moving mechanism A cover 12 is provided.

  The X-axis movement mechanism includes a pair of X-axis guide rails (not shown) parallel to the X-axis direction, and the X-axis movement table 10 is slidably attached to the X-axis guide rails. A nut portion (not shown) is provided on the lower surface side of the X-axis moving table 10, and an X-axis ball screw (not shown) parallel to the X-axis guide rail is screwed to the nut portion.

  An X-axis pulse motor (not shown) is connected to one end of the X-axis ball screw. By rotating the X-axis ball screw with the X-axis pulse motor, the X-axis moving table 10 moves in the X-axis direction along the X-axis guide rail.

  On the X-axis moving table 10, a chuck table 14 for sucking and holding the workpiece 11 is provided. Around the chuck table 14, four clamps 16 for fixing the annular frame 15 from four directions are provided. The chuck table 14 moves in the X-axis direction together with the X-axis moving table 10 by the above-described X-axis moving mechanism. Details of the chuck table 14 will be described later.

  A cantilever-like support structure 20 that supports a cutting unit (cutting means) 18 for cutting the workpiece 11 is disposed at a position adjacent to the opening 4a. A cutting unit moving mechanism 22 that moves the cutting unit 18 in the Y-axis direction (left-right direction, index feed direction) and Z-axis direction (vertical direction) is provided on the upper front surface of the support structure 20.

  The cutting unit moving mechanism 22 includes a pair of Y-axis guide rails 24 arranged in front of the support structure 20 and parallel to the Y-axis direction. A Y-axis moving plate 26 constituting the cutting unit moving mechanism 22 is slidably attached to the Y-axis guide rail 24.

  A nut portion (not shown) is provided on the back surface side (rear surface side) of the Y-axis moving plate 26, and a Y-axis ball screw 28 parallel to the Y-axis guide rail 24 is screwed to the nut portion. Yes. A Y-axis pulse motor (not shown) is connected to one end of the Y-axis ball screw 28. If the Y-axis ball screw 28 is rotated by the Y-axis pulse motor, the Y-axis moving plate 26 moves along the Y-axis guide rail 24 in the Y-axis direction.

  A pair of Z-axis guide rails 30 parallel to the Z-axis direction are provided on the surface (front surface) of the Y-axis moving plate 26. A Z-axis moving plate 32 is slidably attached to the Z-axis guide rail 30.

  A nut portion (not shown) is provided on the back surface side (rear surface side) of the Z-axis moving plate 32, and a Z-axis ball screw 34 parallel to the Z-axis guide rail 30 is screwed into the nut portion. Yes. A Z-axis pulse motor 36 is connected to one end of the Z-axis ball screw 34. When the Z-axis ball screw 34 is rotated by the Z-axis pulse motor 36, the Z-axis moving plate 32 moves in the Z-axis direction along the Z-axis guide rail 30.

  A cutting unit 18 is provided below the Z-axis moving plate 32. The cutting unit 18 includes an annular cutting blade 38 attached to one end of a spindle (not shown). A rotation drive source (not shown) such as a motor is connected to the other end side of the spindle, and rotates a cutting blade 38 attached to the spindle. A camera 40 that captures an image of the workpiece 11 is installed at a position adjacent to the cutting unit 18.

  When the Y-axis moving plate 26 is moved in the Y-axis direction by the cutting unit moving mechanism 22, the cutting unit 18 and the camera 40 are moved in the Y-axis direction. Moreover, if the Z-axis moving plate 32 is moved in the Z-axis direction by the cutting unit moving mechanism 22, the cutting unit 18 and the camera 40 are moved in the Z-axis direction.

  A circular opening 4b is formed at a position opposite to the cassette elevator 6 of the opening 4a. In the opening 4b, a cleaning unit 42 for cleaning the workpiece 11 and the like after cutting is provided. On the other hand, a nozzle 44 for injecting fluid such as air toward the lower chuck table 14 is provided above the opening 4a. The nozzle 44 is disposed across the opening 4a serving as a moving path of the chuck table 14 in the Y-axis direction.

  When cutting the workpiece 11 with the cutting apparatus 2 configured in this way, first, the workpiece 11 is unloaded from the cassette 8 and held on the chuck table 14. Next, the chuck table 14 and the cutting unit 18 are relatively moved and rotated to align the position of the cutting blade 38 on the extension line of the division planned line to be processed.

  Thereafter, the cutting blade 38 is rotated and lowered to a height at which it can contact the workpiece 11, and the chuck table 14 is moved in a direction parallel to the division line to be processed. As a result, the workpiece 11 can be cut along the planned division line and divided into a plurality of chips 17 (see FIG. 2A). The workpiece 11 after cutting is, for example, unloaded from the chuck table 14 and sent to the cleaning unit 42.

  FIG. 2A is a partial cross-sectional side view schematically showing how the workpiece 11 is unloaded from the chuck table 14. As shown in FIG. 2A, the chuck table 14 includes a disk-shaped frame 46. A circular recess 46a is formed on the upper surface of the frame 46, and a holding plate 48 that matches the shape of the recess 46a is fitted in the recess 46a.

  The holding plate 48 is made of, for example, a porous material, and the upper surface thereof serves as a holding surface 48 a that holds the wafer 11. The recess 46a is connected to the suction source 52 via a flow path 46b, a valve 50, and the like formed inside the frame 46, and is connected to a fluid supply source 56 via the flow path 46b, the valve 54, and the like. That is, the holding surface 48 a of the holding plate 48 can be selectively connected to the suction source 52 and the fluid supply source 56.

  When the workpiece 11 is held by the chuck table 14, the valve 54 is closed and the valve 50 is opened, and the negative pressure of the suction source 52 is applied to the holding plate 48. As a result, a suction force for sucking the workpiece 11 is generated on the holding surface 48a. On the other hand, when the workpiece 11 is unloaded from the chuck table 14, the valve 50 is closed to block the negative pressure of the suction source 52. At this time, the valve 54 may be closed or opened.

  Further, as shown in FIG. 2A, a conveyance unit 58 that conveys the workpiece 11 is disposed in the vicinity of the chuck table 14. The transport unit 58 includes a holding hand 60 that holds the workpiece 11. A plurality of suction tools 62 for sucking the annular frame 15 are provided on the lower surface of the holding hand 60. The workpiece 11 after cutting is unloaded from the chuck table 14 by the transport unit 58.

  FIG. 2B is a partial cross-sectional side view schematically showing the chuck table 14 after the workpiece 11 is unloaded. For example, when the workpiece 11 is unloaded from the chuck table 14 and then cleaned by the cleaning unit 42, the foreign matter 19 such as the end material scattered by the cleaning is applied to the holding surface 48a of the chuck table 14 as shown in FIG. You may get on. Further, there is a possibility that foreign matters such as processing waste adhere to the holding surface 48 a of the chuck table 14.

  Therefore, in the chuck table cleaning method according to the present embodiment, the foreign matter 19 on the holding surface 48 is removed using a fluid such as air. 3A and 3B are partial cross-sectional side views schematically showing a chuck table cleaning method according to the present embodiment.

  In the chuck table cleaning method according to the present embodiment, first, the valve 50 is closed and the valve 54 is opened, and the fluid is supplied from the fluid supply source 56 to the holding plate 48. Thereby, as shown in FIG. 3A, the fluid A can be ejected from the holding surface 48a of the holding plate 48. The fluid B is also ejected from the nozzle 44 disposed above the chuck table 14.

  Further, in this state, the chuck table 14 is moved in the X-axis direction so as to pass under the nozzle 44. As described above, the foreign matter 19 is easily lifted by the fluid A ejected from the holding surface 48a. Therefore, the foreign matter 19 can be blown out of the chuck table 14 by allowing the fluid B to act on the holding surface 48 a of the chuck table 14 by passing under the nozzle 44 that has injected the fluid B. The flow rates of the fluids A and B are adjusted within a range in which the foreign matter 19 can be appropriately removed.

  As described above, in the chuck table cleaning method according to the present embodiment, the fluid A is ejected from the holding surface 48a of the chuck table 14 and the fluid B is ejected from the nozzle 44, and passes under the nozzle 44. Thus, the foreign matter 19 on the holding surface 48a is easily lifted by the fluid A ejected from the holding surface 48a, and is blown off to the outside of the holding surface 48a by the fluid B ejected from the nozzle 44. It is. Thereby, the foreign material on the holding surface 48a can be removed appropriately.

  In addition, this invention is not limited to description of the said embodiment, A various change can be implemented. For example, a fluid other than air may be used as the fluid A ejected from the holding surface 48a and the fluid B ejected from the nozzle 44. Specifically, for example, a liquid such as water can be used. The types of fluids A and B may not be the same. For example, air can be used as the fluid A, and fluid (two fluids) in which air and water are mixed can be used as the fluid B.

  In addition, the structure, method, and the like according to the above-described embodiment can be appropriately modified and implemented without departing from the scope of the object of the present invention.

DESCRIPTION OF SYMBOLS 11 Workpiece 13 Dicing tape 15 Frame 17 Tip 19 Foreign object A, B Fluid 2 Cutting device 4 Base 4a, 4b Opening 6 Cassette elevator 8 Cassette 10 X-axis moving table 12 Dust-proof drip-proof cover 14 Chuck table 16 Clamp 18 Cutting unit (Cutting means)
DESCRIPTION OF SYMBOLS 20 Support structure 22 Cutting unit moving mechanism 24 Y-axis guide rail 26 Y-axis moving plate 28 Y-axis ball screw 30 Z-axis guide rail 32 Z-axis moving plate 34 Z-axis ball screw 36 Z-axis pulse motor 38 Cutting blade 40 Camera 42 Cleaning unit 44 Nozzle 46 Frame 46a Recess 46b Flow path 48 Holding plate 48a Holding surface 50 Valve 52 Suction source 54 Valve 56 Fluid supply source 58 Transport unit 60 Holding hand 62 Suction tool

Claims (1)

A chuck table having a holding surface that can be selectively connected to a suction source and a fluid supply source, and holding the workpiece by suction with the holding surface, and a cutting means for cutting the workpiece held on the chuck table And a chuck table moving means for moving the chuck table in the cutting feed direction, and a nozzle that is disposed across the movement path of the chuck table and ejects fluid toward the holding surface. A chuck table cleaning method used for cleaning
The chuck table is moved so as to pass under the nozzle in a state in which the holding surface is connected to the fluid supply source and fluid is ejected from the holding surface and fluid is ejected downward from the nozzle. And cleaning the foreign matter on the holding surface.

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