JP5183262B2 - Cutting device and chip production method - Google Patents

Description

  The present invention relates to a cutting apparatus having a cutting blade for cutting a workpiece (workpiece) such as a semiconductor wafer, and more particularly, a cutting blade detecting means having a light emitting part and a light receiving part for detecting the cutting blade. The present invention relates to a cutting device.

  For example, in a semiconductor device manufacturing process, a circuit (cutting line) that forms circuits such as ICs and LSIs in a large number of areas formed in a grid on the surface of a semiconductor wafer having a substantially disk shape, and divides each circuit. Each semiconductor chip is manufactured by cutting and dicing.

  As an apparatus for dicing a semiconductor wafer in this way, for example, a cutting apparatus as shown in Patent Document 1 is used. The cutting apparatus includes a chuck table that holds a workpiece, a cutting mechanism that includes a cutting blade that cuts the workpiece held on the chuck table, and a reference position for controlling the cutting depth of the cutting blade. A cutting blade detector used for setting and detecting chipping and wear of the cutting blade is provided. When cutting the workpiece held on the chuck table in this cutting apparatus, cutting water is supplied to the contact portion between the rotating cutting blade and the workpiece, so that the cutting waste generated by the cutting is removed. The mixed cutting water may scatter and adhere to the cutting blade detector. The cutting blade detector is configured to receive the light emitted from the light emitting unit at the light receiving unit and detect the cutting blade according to the change in the amount of received light. If it adheres to the part, there is a problem that the amount of light received by the light receiving part changes due to the adhering substance, and the position of the cutting blade cannot be recognized accurately, or the cutting blade is erroneously recognized as chipped or worn. Therefore, in order to solve such a problem, the present applicant has proposed a cutting apparatus having a cover mechanism that prevents cutting water from adhering by covering the light emitting part and the light receiving part (see Patent Document 1).

JP 2003-2111354 A

  However, since the cutting water mists and scatters when the cutting blade rotates at high speed, even if the light emitting unit and the light receiving unit are covered by the cover mechanism, if there is even a slight gap, the cutting water enters from the gap. Therefore, it is difficult to sufficiently prevent the light from adhering to the light emitting part and the light receiving part.

  The present invention has been made in view of the above-mentioned facts, and its main technical problem is to prevent the cutting water scattered during the cutting operation from adhering to the light emitting part and the light receiving part of the cutting blade detector, and to detect the cutting blade. The tool is to always detect the position and state of the cutting blade accurately.

A first invention includes a holding means for holding a workpiece, a cutting means for cutting a workpiece while supplying cutting water to the workpiece having a rotatable cutting blade and held by the holding means, a light emitting portion, and a light receiving portion. The cutting blade detecting means includes an open state in which the light emitting part and the light receiving part are exposed, and a protective state in which the light emitting part and the light receiving part are surrounded and not exposed. The protective cover means includes a bottom portion on which the light emitting portion and the light receiving portion are erected and a groove for storing water is formed, and a closed position that covers the light emitting portion and the light receiving portion. It has a lid portion that is selectively positioned at the open position that exposes the light emitting portion and the light receiving portion, and a drive portion that positions the lid portion at the closed position and the open position, and is protected by a water seal. Water in the groove at the bottom The cutting blade detection means includes a cleaning water supply nozzle that supplies cleaning water to the light emitting part and the light receiving part. The storage part is formed by water discharged from a cleaning water supply nozzle .

  The drive unit performs control to position the lid in the closed position at least when cutting the workpiece with the cutting blade, and position the lid in the open position at least when detecting the cutting blade.

  The second invention relates to a method for producing a chip that uses the above-described cutting device to cut the work held by the holding means by the cutting means and divide the work into individual chips. At least while supplying cutting water to the work While the cutting blade is cut into the workpiece and the cutting process is performed, the protective cover means is set in the above-described protective state.

  In the above chip production method, the protective cover means is opened, the cutting blade constituting the cutting blade is aligned with the region between the light emitting portion and the light receiving portion, the cutting blade is lowered, and the light emitting portion is cut by the cutting blade. The vertical position of the cutting blade when the amount of light received by the light receiving unit decreases due to the light emitted from the light receiving unit being blocked can be used as the reference position in the cutting direction.

  In the cutting device according to the present invention, the protective cover means is protected by water sealing, so that the light emitting portion and the light receiving portion can be reliably surrounded and protected without gaps. And can be cut off from the space where the cutting waste is scattered. Therefore, cutting water and cutting waste do not adhere to the light emitting part and the light receiving part, and the cutting blade detection means can always detect the position and state of the cutting blade accurately.

The protective cover means has a light emitting portion and a light receiving portion standing upright and a bottom portion in which a groove for storing water is formed, a closed position that covers the light emitting portion and the light receiving portion, and an open position that exposes the light emitting portion and the light receiving portion. The lid portion is selectively positioned, and the drive portion is positioned at the closed position and the open position, and the water seal is formed at the end of the lid portion in the storage portion formed by collecting water in the bottom groove. Because it is performed in a state where the part is immersed, even if a gap occurs between the bottom part and the cover part due to variations in the positioning accuracy and shape accuracy of the cover part, and the assembly accuracy of parts such as the bottom part and the cover part, By sealing the gap, it is possible to reliably prevent cutting water and cutting chips from entering.

Comprising a cleaning water supply nozzle for supplying cleaning water to the light-emitting portion and the light receiving portion to the cutting blade detection means, since the reservoir is formed by the water discharged from the washing water supply nozzle, a new water supply arrangement for the water seal Is no longer necessary. Moreover, since the washing water used for washing the light emitting unit and the light receiving unit can be used for water sealing, it also saves water.

  When the drive unit has a function of positioning the lid in the closed position at least when cutting the workpiece with the cutting blade, and at least detecting the cutting blade, the lid is in the closed position when cutting. Since cutting water and cutting waste do not adhere to the light emitting part and the light receiving part when the cutting blade is detected, the cutting blade can be detected with high accuracy.

  In the chip production method according to the present invention, at least while the cutting blade is cut into the workpiece while cutting water is being supplied to the workpiece, the protective cover means is in a protected state. Even if splatters, the protective cover means is in a protected state, so that cutting water or cutting waste does not adhere to the light emitting part and the light receiving part.

  Also, since cutting water and cutting debris do not adhere to the light emitting part and the light receiving part during workpiece cutting, the protective cover means is opened, and the cutting blade of the cutting blade is aligned with the region between the light emitting part and the light receiving part. If the reference position in the cutting direction of the cutting blade is set, the reference position in the cutting direction of the cutting blade can be set with high accuracy.

  A cutting apparatus 1 shown in FIG. 1 includes a cutting means 2 for cutting a workpiece (workpiece) such as a semiconductor wafer. Workpieces require, for example, wafers such as semiconductor wafers, adhesive members such as die attach films provided on the backside of wafers for chip mounting, semiconductor product packages, glass or silicon substrates, and micron-order processing accuracy. And various processed materials. The cutting process includes complete cutting and grooving.

  The cutting means 2 includes a rotary shaft 20 having a horizontal axis, a housing 21 that rotatably supports the rotary shaft 20, a cutting blade 22 attached to one end portion of the rotary shaft 20, and a cutting blade 22. And a blade cover 23 that covers from above. The cutting blade 22 is formed by fixing a cutting blade 221 to the peripheral edge of the base 220, and is fixed to the rotary shaft 20 by a nut 24. A motor (not shown) is connected to the other tip portion (the tip portion on which the cutting blade 22 is not mounted) of the rotary shaft 20, and the rotary shaft 20 is rotated by being driven by the motor, and the cutting blade 22 is also rotated. It has a configuration. The blade cover 23 has a pair of cutting water supply nozzles 230 disposed on both sides of the cutting blade 22, and the cutting water supply nozzle 230 makes contact with the cutting blade 221 of the cutting blade 22 and the contact portion of the workpiece. Cutting water can be supplied. The cutting means 2 is movable in the Y-axis direction that is the axial center direction of the rotary shaft 20 and the Z-axis direction that is a perpendicular direction perpendicular to the Y-axis direction. Further, the direction orthogonal to the horizontal direction with respect to the Y-axis direction is the X-axis direction.

  Below the position where the cutting blade 22 can be located by movement in the Y-axis direction, a cutting blade detection means 3 that is a sensor for detecting the cutting blade 22 is disposed. The cutting blade detection means 3 is used for determining a reference position for the movement of the cutting blade 22 in the Z-axis direction, and for detecting the chipping or wear state of the cutting blade 221, and the light emitting unit 30 and the light receiving unit. 31 is configured such that the optical axis of the light emitted from the light emitting unit 30 and received by the light receiving unit 31 is the same as the Y-axis direction and the thickness direction of the cutting blade 221 is configured. Yes. An accommodating region 32 for accommodating the cutting blade 22 is formed between the light emitting unit 30 and the light receiving unit 31.

  The cutting blade detection unit 3 includes a protective cover unit 33 that can selectively take an open state in which the light emitting unit 30 and the light receiving unit 31 are exposed and a protective state in which the light emitting unit 30 and the light receiving unit 31 are not exposed. . The protective cover means 33 includes a block 34 that supports the light emitting unit 30 and the light receiving unit 31, and a bottom 35 to which the block 34 is fixed. The light emitting unit 30 and the light receiving unit 31 are connected to the bottom 35 via the block 34. It is the composition that was erected from. In the illustrated example, the bottom portion 35 is formed in a rectangular shape, and includes a bottom plate 350 and a wall portion 351 erected from the periphery thereof, and a region surrounded by the bottom plate 350 and the wall portion 351 forms a recess 352. . Further, in the recess 352, a groove 353 for storing water is formed in a region surrounded by the bottom plate 350, the wall portion 351, and the block 34. The block 34 includes a pair of cleaning water supply nozzles 36 that supply cleaning water to the light emitting unit 30 and the light receiving unit 31 for cleaning, and a jet of air toward the light emitting unit 30 and the light receiving unit 31 to generate cleaning water or the like. An air supply nozzle 37 that blows off deposits is provided.

  The protective cover means 33 includes a lid portion 38 that is selectively positioned at a closed position that covers the light emitting unit 30 and the light receiving unit 31 and an open position that exposes the light emitting unit 30 and the light receiving unit 31. The lid portion 38 has a rotation shaft 380, and the rotation portion 380 is rotated by being driven by the drive portion 39, whereby the lid portion 38 can be rotated to take a closed position and an open position. The drive unit 39 includes two air injection portions 390. When air is injected into one air injection portion 390, the lid portion 38 is positioned in the closed position, and when air is injected into the other air injection portion 390, the lid portion 38 can be positioned in the open position. The two air injection units 390 are connected to an air control unit (not shown), and air is sent from the air control unit to one of the air injection units 390 to drive the lid unit 38. In FIG. 1, the cover part 38 is located in the open position, and the state in which the protective cover means 33 is in an exposed state is shown.

  When the lid portion 38 is in the open position and the protective cover means 33 is in the open state, the reference position of the cutting depth of the cutting blade 22 relative to the workpiece (hereinafter referred to as “setup”), or the cutting blade is set. Inspection of chipping and wear of the 22 cutting blades 221 can be performed. For example, at the time of setup performed before cutting with the cutting blade 22 cut into the workpiece, the protective cover means 3 is opened, and the cutting means 2 is placed on the Y axis so that the cutting blade 22 is positioned directly above the blade detection means 3. After moving in the direction, the cutting means 2 is lowered, and the cutting blade 221 is positioned between the light emitting unit 30 and the light receiving unit 30 in the accommodation region 32 as shown in FIG. At this time, light having a high directivity is always emitted from the light emitting unit 30, and an electric signal corresponding to the intensity of the received light is output from the light receiving unit 31, and the light is not blocked by the cutting blade 221. The amount of light received by the light receiving unit 31 is constant. On the other hand, if the light is further blocked by the cutting blade 22 221, the amount of light received by the light receiving unit 31 is reduced. Therefore, the position in the Z-axis direction (vertical direction) of the cutting blade 22 at that time is set as a reference position in the cutting direction, The cutting control unit 5 that controls the vertical movement of the cutting means 2 in the Z-axis direction stores the Z coordinate of the reference position. The information on the reference position stored in the cutting control unit 5 is used for controlling the cutting depth when cutting the workpiece.

  On the other hand, as shown in FIG. 3, when the lid portion 38 is located at the closed position, the protective cover means 33 is in a protected state. In the protected state, the light emitting unit 30, the light receiving unit 31, the block 34, the cleaning water supply nozzle 36, and the air supply nozzle 37 shown in FIG. Then, as shown in FIG. 4, water accumulates in the groove 353 formed in the bottom portion 35 to form a storage portion 353 a, and the end portion 38 a of the lid portion 38 is immersed in the storage portion 353 a, whereby the bottom portion 35 and the lid portion are formed. Water enters a gap formed between the protective cover means 33 and the protective cover means 33. That is, water sealing is to block a portion that can be a gap with water. At this time, the lower end of the end portion 38a of the lid portion 38 is at a position lower than the upper end of the wall portion 351 constituting the bottom portion 35, and the water surface of the storage portion 353a is higher than the lower end of the end portion 38a of the lid portion 38. It is lower than the upper end. In this way, the protective cover means 33 surrounds the light emitting unit 30 and the light receiving unit 31 with a water seal without a gap, and enters a protected state. The water constituting the reservoir 353a can be discharged from the cleaning water supply nozzle 36 shown in FIG. When the water discharged from the cleaning water supply nozzle 36 is used for the storage portion 353a, a new water supply means for sealing the water becomes unnecessary, and conventionally, the water is ejected for cleaning the light emitting portion 30 and the light receiving portion 31. The used cleaning water that has been drained after the operation can be used as it is for the storage portion 353a, and there is also a water-saving effect. Since the water stored in the storage part 353a does not adhere to the light emitting part 30 and the light receiving part 31, even if used washing water is used, the light emitting part 30 and the light receiving part 31 are not adversely affected. In addition to the cleaning supply nozzle 36, a means for supplying water to the groove 353 may be provided.

  As shown in FIG. 5, in the cutting apparatus 1, the workpiece W is held by the holding unit 4, the holding unit 4 moves in the X-axis direction (see FIG. 1), and the cutting blade 22 that rotates at high speed cuts into the workpiece W. Thus, cutting is performed. The cutting depth of the cutting blade 22 at this time is controlled based on the reference position stored in the cutting control unit 5 by the setup. Further, at the time of cutting, the cutting water 230 a is discharged from the cutting water supply nozzle 230 to the contact portion between the cutting blade 22 and the workpiece W. Then, the cutting water 230 a scatters in the form of mist-like cutting water 230 b together with the cutting waste generated by cutting by the rotation of the cutting blade 22, and also scatters in the direction of the cutting blade detection means 3.

  Therefore, while cutting the workpiece W by the cutting blade 22 while supplying the cutting water 230a to the workpiece W, the lid portion 38 is positioned at the closed position under the control of the driving unit 39 shown in FIGS. The storage portion 353a is formed in 353 and sealed with water, so that the light emitting portion 30 and the light receiving portion 31 are reliably surrounded without any gaps, and the protective cover means 33 is brought into a protected state. In the protected state, the light emitting unit 30 and the light receiving unit 31 can be completely blocked from the space where the cutting water 230b and cutting chips scatter, so that the cutting water 230b and cutting chips adhere to the light emitting unit 30 and the light receiving unit 31. There is no.

  Further, since the protection state is formed by forming a storage portion 353a in a gap formed between the bottom portion 35 and the lid portion 38 and sealing with water, the positioning accuracy and shape accuracy of the lid portion 38, the bottom portion 35, Even if the assembling accuracy of the parts such as the lid portion 38 varies, the gap can be surely filled by water sealing.

  On the other hand, when the cutting water 230b is not scattered, such as during the setup that is performed before cutting the workpiece W or immediately after the cutting blade 22 is replaced, or when the cutting blade 221 is inspected for chipping or wear after cutting or between cuts. When the operation of detecting the cutting blade 22 by the cutting blade detecting means 3 is performed, as shown in FIG. 1, the cover 38 is positioned at the open position and the protective cover means 33 is opened, as shown in FIG. In this way, the cutting blade 221 of the cutting blade 22 is positioned between the light emitting unit 30 and the light receiving unit 31 and processing based on the amount of light received by the light receiving unit 31 is performed. Since the cutting water and cutting chips are prevented from adhering to the light emitting unit 30 and the light receiving unit 31 as a protected state by water sealing, light emission from the light emitting unit 30 and light reception at the light receiving unit 31 are always normal. It takes place. Therefore, the setting of the reference position in the setup can be performed with high accuracy, and the chipping and wear of the cutting blade 221 can be detected with high accuracy, thereby improving the workpiece cutting accuracy.

  When the cutting apparatus 1 is not used, it is desirable to keep the protective cover means 33 in a protected state in order to prevent foreign matter from adhering to the light emitting unit 30 and the light receiving unit 31.

It is a perspective view which shows a cutting means and a cutting blade detection means. It is sectional drawing which shows schematically the exposure state of a protective cover means. It is a perspective view which shows the sealing state of a protective cover means. It is sectional drawing which shows schematically the sealing state of a protective cover means. It is sectional drawing which shows the state which cuts a workpiece | work schematically.

1: Cutting device 2: Cutting means 20: Rotating shaft 21: Housing 22: Cutting blade 220: Base 221: Cutting blade 23: Blade cover 230: Cutting water supply nozzle 230a: Cutting water 230b: Atomized cutting water 24: Nut 3: Cutting blade detection means 30: Light emitting part 31: Light receiving part 32: Storage area 33: Protection cover means 34: Block 35: Bottom part 350: Bottom plate 351: Wall part 352: Recessed part 353: Groove 353a: Reserving part 36: Cleaning Water supply nozzle 37: Air supply nozzle 38: Lid 380: Rotating shaft 39: Drive unit 390: Air injection unit 4: Holding means 5: Cutting control unit

Claims (4)

A holding means for holding the workpiece, a cutting means for cutting the workpiece while supplying cutting water to the workpiece held by the holding means, and a light emitting portion and a light receiving portion. In a cutting apparatus including a cutting blade detection means for detecting a cutting blade,
The cutting blade detection means has protective cover means that can selectively take an open state in which the light emitting part and the light receiving part are exposed, and a protective state in which the light emitting part and the light receiving part are surrounded and not exposed,
The protective cover means includes a bottom portion on which the light emitting portion and the light receiving portion are erected and formed with a groove for collecting water, a closed position that covers the light emitting portion and the light receiving portion, and the light emitting portion and the light receiving portion. A lid portion that is selectively positioned at the open position to be exposed; and a drive portion that positions the lid portion at the closed position and the open position;
The water sealing is performed in a state in which the end of the lid portion located at the closed position is immersed in a storage portion formed by storing water in the groove at the bottom,
The cutting blade detection means includes a cleaning water supply nozzle that supplies cleaning water to the light emitting unit and the light receiving unit,
The storage section is formed by water discharged from the cleaning water supply nozzle . The cutting device according to claim 1 , wherein the driving unit positions the lid at the closed position at least when the workpiece is cut by the cutting blade, and positions the lid at the open position at least when the cutting blade is detected. A method for producing a chip using the cutting device according to claim 1 or 2 , wherein the work held by the holding means is cut by the cutting means and divided into individual chips.
A chip production method in which the protective cover means is in the protected state at least during cutting with the cutting blade being cut into the workpiece while supplying cutting water to the workpiece. The protective cover means is opened, the cutting blade constituting the cutting blade is aligned with the region between the light emitting portion and the light receiving portion, and the cutting blade is lowered to emit light from the light emitting portion. The chip production method according to claim 3 , wherein the vertical position of the cutting blade when the received light is blocked and the amount of light received by the light receiving portion is reduced is used as a reference position in the cutting direction.

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