JP5422176B2 - Holding table and cutting device - Google Patents

Description

  The present invention relates to a holding table and a cutting device, and more particularly to a holding table and a cutting device on which a workpiece is held by suction.

  In the manufacturing process of a semiconductor device, a substantially disk-shaped workpiece has an adhesive tape attached to the back surface and is supported by an annular frame via the adhesive tape. Streets (division planned lines) are formed in a lattice pattern on the surface of the work, and circuits such as ICs and LSIs are formed in areas partitioned by the streets. Then, the workpiece is cut along the street by a dicing device as a cutting device, and is divided into individual semiconductor chips. The semiconductor chip thus divided is packaged and widely used in electric devices such as mobile phones and personal computers.

  Conventionally, as such a dicing apparatus, an apparatus provided with a holding table for sucking and holding a workpiece is known (for example, see Patent Document 1). As shown in FIG. 7, the conventional holding table 61 includes a frame holding portion 64 that holds the annular frame 73 by a clamp or the like, and a work holding portion 63 that holds the workpiece W by suction via an adhesive tape 72. A suction holding surface 63a that generates a negative pressure is formed at the center of the upper surface of the work holding unit 63, and a support surface 63b that supports the adhesive tape 72 is formed around the suction holding surface 63a.

Then, when cutting is started in a state where the annular frame 73 is clamped and fixed to the frame holding portion 64 and the workpiece W is sucked and held by the workpiece holding portion 63 via the adhesive tape 72, the blade unit of the dicing apparatus is started. Cutting water is sprayed toward the workpiece W from a plurality of nozzles provided on the workpiece W to cool and clean the cutting portion of the workpiece W and the cutting blade.
Japanese Patent Laid-Open No. 11-8211

  However, since cutting water is ejected from a plurality of nozzles during dicing, a part of the ejected cutting water becomes mist-like water droplets and scatters around the chuck table 61, and the periphery of the chuck table 61 is mist-like. It was covered in the atmosphere. At this time, the adhesive tape 72 is strongly adhered to the support surface 63b, but it is difficult to completely fill the gap between the adhesive tape 72 and the support surface 63b. A slight gap is generated at the contact portion with the outer peripheral edge.

  And when a negative pressure generate | occur | produces on the adsorption holding surface 63a, the water droplet of the mist-like cutting water which exists in the vicinity of the adsorption holding surface 63a is attracted | sucked from the clearance gap between the sticking tape 72 and the outer periphery of the support surface 63b. The sucked water droplets are sucked to the suction source through the suction holding surface 63a and the piping in the table support portion 62, and there is a problem that the suction force of the holding surface is reduced.

  This invention is made | formed in view of this point, and it aims at providing the holding table and cutting device which can prevent the fall of the holding | maintenance force of a workpiece | work in a foggy atmosphere.

The holding table of the present invention includes a frame holding unit that holds a frame having an opening, and a work holding unit that has a suction holding surface that holds the work held by the opening of the frame holding unit via an adhesive tape. The work holding unit is formed around the suction holding surface, and communicates a support surface that supports the adhesive tape, a predetermined region of the support surface, and the atmosphere side. possess a communicating portion, the communicating portion, the is composed of a groove formed to surround the suction holding surface, and the through hole for communicating the the space and the atmosphere formed in the groove, said through The hole is characterized in that one end is opened on the bottom surface of the groove and the other end is opened on the opposite side to the suction holding surface forming side in the work holding unit .

According to this configuration, when a negative pressure is generated on the suction holding surface, air is sucked from the atmosphere side through the communication portion, so that there is a slight gap at the contact portion between the adhesive tape and the outer peripheral edge of the support surface. In this case, the suction force from this gap can be reduced. Therefore, even if the cutting water is sprayed and scattered as mist-like water droplets around the holding table, the amount of water droplets sucked into the suction source from the gap between the adhesive tape and the outer peripheral edge of the support surface Can be suppressed, and a decrease in holding power can be prevented. In this case, it is preferable that the end of the communicating portion on the air atmosphere side is opened to a position where scattered water droplets are diluted. Further, when negative pressure is generated on the suction holding surface, air sucked from the through hole is sucked to the suction holding surface through a groove formed so as to surround the suction holding surface. The suction force generated in the gap at the contact portion with the outer peripheral edge can be reduced over the entire circumference. Further, since the water droplets of the cutting water scattered by the cutting water jet are thin on the opposite side of the workpiece holding portion from the suction holding surface forming side, the suction amount of the water droplets can be reduced.

  The cutting apparatus of the present invention includes the above holding table and a cutting blade for cutting the workpiece, and relatively moves the cutting blade and the holding table while supplying cutting water to the cutting blade. It is characterized by cutting a workpiece.

  According to this configuration, it is possible to provide a cutting device capable of performing stable cutting while maintaining the holding force of the holding table in a foggy atmosphere.

  According to the present invention, it is possible to prevent the work holding force from being lowered in a foggy atmosphere.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, before describing the cutting apparatus according to the embodiment of the present invention, a semiconductor wafer to be cut will be briefly described. FIG. 1 is a perspective view of a semiconductor wafer supported by an annular frame.

  As shown in FIG. 1, the semiconductor wafer W is formed in a substantially disk shape, and is partitioned into a plurality of regions by division lines arranged in a lattice pattern on the surface, and IC, LSI are formed in the partitioned regions. The device 71 is formed. Further, the semiconductor wafer W is supported by the annular frame 73 via the sticking tape 72 and is carried into and out of the cutting apparatus 1 while being accommodated in a cassette (not shown).

  In the present embodiment, a semiconductor wafer such as a silicon wafer will be described as an example of the workpiece. However, the present invention is not limited to this configuration, and a DAF (Die Attach Film) attached to the semiconductor wafer W is not limited thereto. The workpiece may be an adhesive member such as a semiconductor product package, ceramic, glass, sapphire, a silicon-based substrate, various electrical components, or various processed materials that require micron-order accuracy.

  Next, a cutting apparatus according to an embodiment of the present invention will be described with reference to FIG. FIG. 2 is an external perspective view of the cutting apparatus according to the embodiment of the present invention. FIG. 3 is an external perspective view of the cutting unit of the cutting apparatus according to the embodiment of the present invention.

  As shown in FIG. 2, the cutting apparatus 1 has a rectangular parallelepiped housing 2, and a cutting unit 3 is accommodated in the housing 2 (see FIG. 3). The cutting unit 3 includes a chuck table 13 for taking the semiconductor wafer W into the housing 2, and FIG. 2 shows a state in which the chuck table 13 is moved to the outside and waited in front of the housing 2. In front of the housing 2, adjacent to the chuck table 13 moved to the outside of the housing 2, a loading / unloading unit 4 for loading and unloading a cassette in which the semiconductor wafer W is stored, and a semiconductor wafer W that has been cut. And a cleaning unit 5 for cleaning the water.

  Further, on the front surface portion 2 a of the housing 2, a push-pull arm 6 that transfers the semiconductor wafer W between the loading / unloading portion 4 and the chuck table 13, and a semiconductor wafer between the chuck table 13 and the cleaning unit 5. Are provided with an upper arm 7 and a lower arm 8. Further, a pair of guide rails 15 are provided above the chuck table 13, and the pair of guide rails 15 are configured to be separated from each other and accessible. Further, a touch panel type monitor 9 for setting various processing conditions such as a cutting speed for controlling the cutting device 1 and a supply amount of cutting water is provided on one side surface 2b of the housing 2.

  The carry-in / carry-out unit 4 includes a placement plate 11 on which the cassette is placed, and the placement plate 11 is configured to be movable up and down. The carry-in / carry-out unit 4 adjusts the drawing position and the pushing position of the semiconductor wafer W in the height direction by moving the placing plate 11 up and down with the cassette placed.

  The cleaning unit 5 includes a cleaning table 12 in which a circular opening 5a is formed on the upper surface, and a semiconductor wafer W that has been cut is held in the center of the opening 5a. The cleaning table 12 is configured to be movable up and down between the opening 5 a on the upper surface of the cleaning unit 5 and the inside of the cleaning unit 5. The semiconductor wafer W that has been cut is held by the cleaning table 12 when the cleaning table 12 is positioned in the opening 5 a and is cleaned when the cleaning table 12 is lowered into the cleaning unit 5.

  The push-pull arm 6 is placed on the pair of guide rails 15 in addition to the semiconductor wafer W being pulled out of the cassette and placed on the pair of guide rails 15 in the state where the cassette height is adjusted in the loading / unloading unit 4. The formed semiconductor wafer W is pushed into the cassette. The pair of guide rails 15 come close to each other when the semiconductor wafer W is placed and supports the semiconductor wafer W, positions the semiconductor wafer W with respect to the chuck table 13, and when the semiconductor wafer W is not placed, the chuck table. The 13 mounting surfaces are spaced apart from each other. The upper arm 7 picks up the semiconductor wafer W placed on the pair of guide rails 15 and places the semiconductor wafer W on the chuck table 13 between the pair of spaced apart guide rails 15. The wafer W is picked up and placed on the cleaning table 12. The lower arm 8 is configured to pick up the cleaned semiconductor wafer W and place it on the pair of guide rails 15.

  As shown in FIG. 3, the cutting unit 3 is configured to cut the semiconductor wafer W by relatively moving the pair of blade units 14 having the cutting blades 41 and the chuck table 13 holding the semiconductor wafer W. . The cutting unit 3 has a base 16, and a chuck table moving mechanism 17 that moves the chuck table 13 in the X-axis direction is provided on the base 16. Further, on the base 16 of the cutting unit 3, a pair of support columns 18 are provided standing between the chuck table moving mechanism 17. The chuck table 13 has an upper portion above the pair of support columns 18. A blade unit moving mechanism 19 for moving the blade unit 14 is provided above.

  The chuck table moving mechanism 17 includes a support base 21 extending in the X-axis direction, a pair of parallel guide rails 22 disposed on the support base 21, and a motor slidably installed on the pair of guide rails 22. And an X-axis table 23 for driving. A chuck table 13 is fixed to the top of the X-axis table 23.

  The blade unit moving mechanism 19 is slidably installed on a support base 25 extending in the Y-axis direction, a pair of guide rails 26 arranged in front of the support base 25, and a pair of guide rails 26. A pair of motor-driven Y-axis tables 27 are provided. The blade unit moving mechanism 19 includes a pair of parallel guide rails 28 disposed on the front surface of each Y-axis table 27 and a motor-driven motor slidably disposed on each of the pair of guide rails 28. And a Z-axis table 29. Each Z-axis table 29 is extended with a blade unit 14.

  Note that nut portions (not shown) are formed on the back sides of the X-axis table 23, the Y-axis tables 27, and the Z-axis tables 29, and ball screws 31 and 32 are screwed into the nut portions (Z-axis). The ball screw for the table is not shown). A pair of drive motors 34, 35, and 36 are connected to both ends of the ball screw 31 for the X-axis table 23, the ball screw 32 for the Y-axis table 27, and the ball screw for the Z-axis table, respectively. The ball screw is rotationally driven by the motors 34, 35, and 36.

  The blade unit 14 has a spindle 42 connected to the cutting blade 41 and a plurality of nozzles (not shown) for injecting cutting water onto the cutting portion. The cutting water 41 is rotated at a high speed by the spindle 42. The cutting process is performed by jetting. Then, the cutting blade 41 is aligned with the division planned line of the semiconductor wafer W by the movement of the Y-axis table 27, and the cutting depth with respect to the semiconductor wafer W is adjusted by the movement of the Z-axis table 29. Thereafter, the X-axis table 23 is moved and cut and fed with the semiconductor wafer W held on the chuck table 13. By repeating the above operations, the semiconductor wafer W is divided along the lattice-shaped division scheduled lines.

  Next, the chuck table will be described in detail with reference to FIGS. 4 and 5. FIG. 4 is an external perspective view of the chuck table according to the embodiment of the present invention. FIG. 5 is a top view of the chuck table according to the embodiment of the present invention. In FIG. 5, only the table portion is shown for convenience of explanation.

  As shown in FIGS. 4 and 5, the chuck table 13 is supported by the table support unit 45 fixed to the upper surface of the X-axis table 23 and the table support unit 45, and is attached to the center of the adhesive tape 72. The work holding unit 46 that holds the semiconductor wafer W by suction and the frame holding unit 47 that holds the annular frame 73 that supports the semiconductor wafer W via the adhesive tape 72 are configured. Inside the table support portion 45, a suction source, piping, and the like are provided to suck and hold the semiconductor wafer W on the work holding portion 46 via the adhesive tape 72. For example, an ejector, a pump, or the like is used as the suction source. Is provided.

  The work holding portion 46 has a disk shape having a predetermined thickness, and a porous suction holding surface 46a is formed in a circular shape at the center of the upper surface. The suction holding surface 46 a is a surface that sucks the semiconductor wafer W through the sticking tape 72 by negative pressure, and is connected to a suction source through a pipe inside the table support portion 45. The periphery of the suction holding surface 46a is an annular support surface 46b, and the adhesive tape 72 is supported around the suction holding surface 46a by the support surface 46b.

  In addition, a groove 46c is formed in the work holding portion 46 along the circumferential direction at a substantially intermediate position in the width direction of the support surface 46b, and the groove 46c extends in an annular shape so as to surround the suction holding surface 46a. In the groove portion 46c, through holes 46d are formed at four positions at intervals of 90 degrees in the circumferential direction, one end of the through hole 46d is opened on the bottom surface of the groove portion 46c, and the other end is on the back side of the support surface 46b of the work holding portion 46. Opened to the rear face 46e. The space formed by the groove 46 c communicates with the atmosphere on the atmosphere located below the work holding portion 46 through the through hole 46 d.

  The frame holding part 47 includes a pair of support arms 51 extending in parallel from the four sides of the table support part 45 in the radial direction and four clamp parts 52 supported by the pair of support arms 51. Yes. Each clamp portion 52 includes a placement plate portion 53 on which the annular frame 73 is placed and a clamping plate portion 54 that sandwiches the annular frame 73 between the placement plate portion 53 and is sandwiched by the air actuator 55. The plate portion 54 is driven to clamp and fix the four sides of the annular frame 73.

  Further, the placement surface of the placement plate portion 53 is located below the support surface 46b of the work holding portion 46 (see FIG. 6). Therefore, when the four sides of the annular frame 73 are clamped and fixed to the frame holding portion 47, an extension force acts on the adhesive tape 72, and the adhesive tape 72 is strongly pressed against the support surface 46b. In this way, the adhesive tape 72 is in close contact with the support surface 46b, and the gap between the adhesive tape 72 and the support surface 46b is reduced.

  Next, with reference to FIG. 6, the work holding function of the chuck table according to the embodiment of the present invention will be described. FIG. 6 is a diagram for explaining the work holding function of the chuck table according to the embodiment of the present invention.

  FIG. 6 shows a state in which cutting is performed in a state where the annular frame 73 is clamped and fixed to the frame holding unit 47 and the semiconductor wafer W is sucked and held by the work holding unit 46 via the adhesive tape 72. ing. When cutting is performed by the cutting device 1, cutting water is jetted from the plurality of nozzles provided in the blade unit 14 toward the semiconductor wafer W, and a part of the jetted cutting water becomes mist-like water droplets. Then, it is scattered around the chuck table 13, and the periphery of the chuck table 13 is covered with a mist-like atmosphere.

  The water droplets of the cutting water scattered around the chuck table 13 wrap around the sticking tape 72 to the side of the work holding unit 46, close to the suction holding surface 46a, and are separated downward from the suction holding surface 46a. It is sparse.

  In this state, when a negative pressure is generated on the suction holding surface 46a, the intake air from the through hole 46d becomes more dominant than the intake air from a slight gap at the contact portion between the adhesive tape 72 and the support surface 46b. The suction force generated in the gap is reduced.

  Further, since air sucked from the through hole 46d is sucked to the suction holding surface 46a through the groove 46c formed so as to surround the suction holding surface 46a, the adhesive tape 72 and the outer peripheral edge of the support surface 46b The suction force generated in the gap between the contact portions is reduced over the entire circumference. Further, since the water droplets in the form of mist become dilute as they are separated below the adsorption holding surface 46a, the water sucked from the through holes 46d contains almost no water droplets of the cutting water. Therefore, it is possible to keep the suction force of the suction source constant by suppressing the suction amount of the water droplets of the cutting water sucked by the suction source via the suction holding surface 46a. Therefore, the cutting apparatus provided with the chuck table 13 can perform stable cutting while maintaining a certain holding force.

  As described above, according to the cutting device 1 according to the present embodiment, when negative pressure is generated on the suction holding surface 46a, air is sucked from the atmosphere side through the through hole 46d and the groove portion 46c, and therefore the adhesive tape When there is a slight gap in the contact portion between 72 and the outer peripheral edge of the support surface 46b, the suction force from this gap can be reduced. Therefore, even if the cutting water is sprayed and scattered as mist-like water droplets around the chuck table 13, the water droplets of the cutting water sucked into the suction source from the gap between the adhesive tape 72 and the outer peripheral edge of the support surface 46b. The suction amount can be suppressed, and the decrease in holding force can be prevented. When a pipe having a small diameter of about 4 [mm] to 6 [mm] is used as the pipe connected to the suction source, the holding power is likely to be reduced due to the influence of water droplets, so the present invention is effective. .

  In the above-described embodiment, one end of the through hole 46d is opened on the bottom surface of the groove 46c and the other end is opened on the back surface 46e of the work holding portion 46. However, the present invention is not limited to this configuration. Absent. Any configuration is possible as long as the space formed by the groove 46c communicates with the atmosphere on the atmosphere side. For example, one end of the through hole 46d may be opened on the side surface of the groove 46c, The other end of the hole 46 d may be opened on the outer peripheral surface of the work holding unit 46. In this case, it is preferable that the other end of the through-hole 46d is opened at a position where the water droplets in the form of mist are dilute.

  In the above-described embodiment, the work holding part 46 is provided with the annular groove 46c and the four through holes 46d. However, the present invention is not limited to this structure. Any configuration may be used as long as the suction force generated in the gap between the adhesive tape 72 and the outer peripheral edge of the support surface 46b is reduced. For example, a configuration in which a plurality of through holes are provided around the suction holding surface 46a. Alternatively, a plurality of arc-shaped long holes may be provided around the suction holding surface 46a.

  The embodiment disclosed this time is illustrative in all respects and is not limited to this embodiment. The scope of the present invention is shown not by the above description of the embodiments but by the scope of the claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

  As described above, the present invention has an effect that it is possible to prevent a decrease in holding force of a workpiece in a mist-like atmosphere, and is particularly useful for a holding table and a cutting apparatus on which the workpiece is held by suction. .

It is a figure which shows embodiment of the cutting device which concerns on this invention, and is a perspective view of the semiconductor wafer supported by the cyclic | annular flame | frame. It is a figure which shows embodiment of the cutting device which concerns on this invention, and is an external appearance perspective view of a cutting device. It is a figure which shows embodiment of the cutting device which concerns on this invention, and is an external appearance perspective view of a cutting unit. It is a figure which shows embodiment of the cutting device which concerns on this invention, and is an external appearance perspective view of a chuck table. It is a figure which shows embodiment of the cutting device which concerns on this invention, and is a top view of a chuck table. It is a figure which shows embodiment of the cutting device which concerns on this invention, and is a figure explaining the workpiece | work holding | maintenance function of a chuck table. It is a figure explaining the workpiece holding function of the conventional chuck table.

Explanation of symbols

1 Cutting device 3 Cutting unit 13 Chuck table (holding table)
14 Blade unit 41 Cutting blade 45 Table support portion 46 Work holding portion 46a Adsorption holding surface 46b Support surface 46c Groove portion (communication portion)
46d Through hole (communication part)
46e Rear side 47 Frame holding part 51 Support arm 52 Clamp part 53 Mounting plate part 54 Holding plate part 55 Air actuator 71 Device 72 Adhesive tape 73 Annular frame W Semiconductor wafer (work)

Claims (2)

A holding table provided with a frame holding part for holding a frame having an opening, and a work holding part having a suction holding surface for sucking and holding a work held on the opening of the frame holding part via an adhesive tape Yes,
The work holding part is
A support surface formed around the adsorption holding surface and supporting the adhesive tape;
Possess a communicating portion for communicating the predetermined region and the air atmosphere side of the support surface,
The communication portion is composed of a groove portion formed so as to surround the adsorption holding surface, and a through hole that communicates the space formed in the groove portion with the atmosphere.
One end of the through hole is opened on the bottom surface of the groove portion, and the other end is opened on the opposite side of the work holding portion to the suction holding surface forming side . A holding table according to claim 1 and a cutting blade for cutting the workpiece, and cutting the workpiece by relatively moving the cutting blade and the holding table while supplying cutting water to the cutting blade. The cutting device characterized by performing.

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