JP2012040651A - Cutting blade detecting mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cutting blade detecting mechanism capable of separately detecting states of individual cutting blades of multiple blades.SOLUTION: This cutting blade detecting mechanism includes: a first blade detecting means for detecting the state of a first cutting blade 28a; and a second blade detecting means for detecting the state of a second cutting blade 28b. In the first blade detecting means, a first light emitting part 76 and a first light receiving part 80 are positioned so as to pinch a first cutting blade 28a, and an optical axis connecting the first light emitting part 76 and the first light receiving part 80 is disposed to be inclined with respect to the shaft center of a spindle 26. In the second blade detecting means, a second light emitting part 84 and a second light receiving part 88 are positioned so as to pinch a second cutting blade 28b, and an optical axis connecting the second light emitting part 84 and the second light receiving part 88 is disposed to be inclined with respect to the shaft center of the spindle 26.

Description

  The present invention relates to a cutting blade detection mechanism in a cutting apparatus including a cutting blade having two cutting blades.

  A semiconductor wafer in which a large number of devices such as IC and LSI are formed on the surface and each device is partitioned by a line to be divided (street) is processed by a grinding machine to have a predetermined thickness after the back surface is ground. A dividing line is cut by a cutting device (dicing device) to be divided into individual devices, and the divided devices are used for electric devices such as mobile phones and personal computers.

  A cutting apparatus includes: a chuck table that holds a semiconductor wafer; a cutting means in which a cutting blade that cuts a wafer held on the chuck table is mounted on a spindle; and a blade detection means that detects chipping and / or wear of the cutting blade The semiconductor wafer can be divided into individual devices with high accuracy (see, for example, JP-A-62-53803).

  A blade detecting mechanism in which the light emitting part and the light receiving part are positioned so as to sandwich the cutting blade of the cutting blade, and the cutting means detects the chipping or wear of the cutting edge by the change in the amount of light received by the light receiving element connected to the light receiving part. Is arranged. When the blade detection mechanism detects chipping or wear of the cutting edge, the cutting blade can be replaced as appropriate.

  On the other hand, in order to improve productivity, a cutting blade having two cutting blades, a so-called multi-blade, has been developed by the present application and is put into practical use (see Japanese Patent Application Laid-Open No. 9-225931). This multi-blade has two cutting blades arranged on both sides of the base with a spacer interposed therebetween, and can cut the two division lines at a time, thereby improving productivity. .

JP-A-62-53803 JP-A-9-225931

  However, in order to detect chipping and / or wear of the cutting blade, it is necessary to arrange a light emitting portion and a light receiving portion so as to sandwich the cutting blade. In a cutting blade having two cutting blades, There is a problem that each cutting blade cannot be detected individually.

  The present invention has been made in view of the above points, and an object of the present invention is to independently detect the state of each cutting edge in a cutting apparatus having a cutting blade having two cutting edges. It is to provide a possible cutting blade detection mechanism.

  According to the present invention, a chuck table for holding a workpiece, and a first cutting blade and a second cutting blade for cutting the workpiece held on the chuck table are arranged at a predetermined interval. A cutting blade detection mechanism used in a cutting apparatus including a cutting means having a cutting blade mounted on a spindle, the first blade detecting means for detecting the state of the first cutting edge, and the second A second blade detecting means for detecting the state of the cutting blade, wherein the first light emitting portion and the first light receiving portion are positioned so as to sandwich the first cutting blade, An optical axis connecting the first light emitting part and the first light receiving part is disposed to be inclined with respect to the spindle center, and the second blade detecting means sandwiches the second cutting edge. And the second light emitting unit and the second light receiving unit are positioned in the second light emitting unit. Optical axis connecting the second light receiving portion cutting blade detection mechanism, characterized in that it is arranged to be inclined with respect to the axis of the spindle is provided with.

  According to the present invention, the optical axis connecting the first light emitting portion and the first light receiving portion is disposed so as to be inclined with respect to the spindle center so as to sandwich the first cutting blade, and sandwich the second cutting blade. In addition, since the optical axis connecting the second light emitting unit and the second light receiving unit is disposed to be inclined with respect to the axis of the spindle, the state of each cutting edge can be detected independently.

It is a schematic perspective view of the cutting device provided with the cutting blade detection mechanism of this invention. It is a disassembled perspective view which shows the relationship between a spindle unit and the blade mount which should be fixed to a spindle. It is a disassembled perspective view which shows the relationship between a spindle unit and the cutting blade which should be mounted | worn with a spindle. It is a perspective view in the state where a cutting blade was attached to a spindle. It is a perspective view of a cutting means (cutting unit). It is a schematic block diagram of the cutting blade detection mechanism which concerns on this invention embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows the external appearance of a cutting apparatus 2 that can divide a semiconductor wafer equipped with a cutting blade detection mechanism of the present invention into individual chips (devices).

  On the front side of the cutting device 2, there is provided operating means 4 for an operator to input instructions to the device such as machining conditions. In the upper part of the apparatus, there is provided a display means 6 such as a CRT for displaying a guidance screen for an operator and an image taken by an imaging means described later.

  The wafer W is attached to a dicing tape T that is an adhesive tape, and the outer peripheral edge of the dicing tape T is attached to an annular frame F. As a result, the wafer W is supported by the frame F via the dicing tape T, and a plurality of wafers (for example, 25 sheets) are accommodated in the wafer cassette 8 shown in FIG. The wafer cassette 8 is placed on a cassette elevator 9 that can move up and down.

  Behind the wafer cassette 8, a loading / unloading means 10 for unloading the wafer W before cutting from the wafer cassette 8 and loading the wafer after cutting into the wafer cassette 8 is disposed. Between the wafer cassette 8 and the loading / unloading means 10, a temporary placement area 12, which is an area on which a wafer to be carried in / out, is temporarily placed, is provided. Positioning means 14 for positioning at a certain position is provided.

  In the vicinity of the temporary placement area 12, transport means 16 having a turning arm that sucks and transports the frame F integrated with the wafer W is disposed, and the wafer W carried to the temporary placement area 12 is It is sucked by the transport means 16 and transported onto the chuck table 18 and is sucked by the chuck table 18 and is held on the chuck table 18 by fixing the frame F by a plurality of clamps 19.

  The chuck table 18 is configured to be rotatable and reciprocally movable in the X-axis direction. Above the movement path of the chuck table 18 in the X-axis direction, an alignment unit 20 that detects a street to be cut of the wafer W is provided. It is arranged.

  The alignment unit 20 includes an imaging unit 22 that images the surface of the wafer W, and can detect a street to be cut by a process such as pattern matching based on an image acquired by imaging. The image acquired by the imaging unit 22 is displayed on the display unit 6.

  A cutting means (cutting unit) 24 for cutting the wafer W held on the chuck table 18 is disposed on the left side of the alignment means 20. The cutting means 24 is configured integrally with the alignment means 20, and both move together in the Y-axis direction and the Z-axis direction.

  The cutting means 24 is configured by attaching a cutting blade 28 to the tip of a rotatable spindle 26 and is movable in the Y-axis direction and the Z-axis direction. The cutting blade 28 is located on the extended line of the imaging means 22 in the X-axis direction.

  Referring to FIG. 2, an exploded perspective view showing the relationship between the spindle and the blade mount attached to the spindle is shown. A spindle 26 that is rotationally driven by a servo motor (not shown) is rotatably accommodated in a spindle housing 32 of the spindle unit 30. The spindle 26 has a tapered portion 26a and a small distal end portion 26b, and a male screw 34 is formed on the small distal end portion 26b.

A blade mount 36 includes a boss part (convex part) 38 and a fixed flange 40 formed integrally with the boss part 38, and a male screw 42 is formed on the boss part 38. Further, the blade mount 36 has a mounting hole 43.
In the blade mount 36, the mounting hole 43 is inserted into the tip small diameter portion 26b and the tapered portion 26a of the spindle 26, and the nut 44 is screwed into the male screw 34 and tightened, so that the tip portion of the spindle 26 as shown in FIG. Attached to.

  FIG. 3 is an exploded perspective view showing a mounting relationship between the spindle 26 to which the blade mount 36 is fixed and the cutting blade 28. The cutting blade 28 is called a multi-blade, and the first cutting edge 28a and the first cutting edge 28a, in which diamond abrasive grains are dispersed in a nickel base material, are spaced apart from each other in the axial direction on the outer periphery of a circular base 46 having a circular hub 48. Two cutting blades 28b are electrodeposited. The distance between the first cutting edge 28a and the second cutting edge 28b is set to the distance (street pitch) between the division lines of the wafer W to be cut.

  By inserting the mounting hole 52 of the cutting blade 28 into the boss portion 38 of the blade mount 36 and screwing the fixing nut 54 into the male screw 42 of the boss portion 38 and tightening, the cutting blade 28 is moved to the spindle 26 as shown in FIG. Attached to.

  Referring to FIG. 5, a perspective view of the cutting means (cutting unit) 24 is shown. The upper half of the cutting blade 28 is covered with a blade cover 56. A detachable cover 58 is detachably attached to the blade cover 56 with screws 60.

  The detachable cover 58 has a cutting water nozzle 66 extending along the side surface of the cutting blade 28, and the cutting water is supplied to the cutting water nozzle 66 through a pipe 64. Similarly, the blade cover 56 also has a cutting water nozzle (not shown) that extends along the side surface of the cutting blade 28, and the cutting water is supplied to the cutting water nozzle via the pipe 62.

  A cutting blade detection mechanism 75 is attached to the blade cover 56. The cutting blade detection mechanism 75 includes a fixed block 68 attached to the blade cover 56 by a screw 70 and a moving block that can move up and down with respect to the fixed block 68 by rotating an adjusting screw 72 as shown in FIG. 74 is included.

  In the moving block 74, the first light emitting unit 76 and the first light receiving unit 80 are positioned so as to sandwich the first cutting edge 28 a, and the optical axis connecting the first light emitting unit 76 and the first light receiving unit 80 is the spindle 26. It is set so that the light from the first light emitting portion 76 is partially blocked by the first cutting edge 28a. The first light emitting unit 76 and the first light receiving unit 80 constitute a first blade detecting unit.

  Similarly, in the moving block 74, the second light emitting portion 84 and the second light receiving portion 88 are positioned so as to sandwich the second cutting blade 28b, and the optical axis connecting the second light emitting portion 84 and the second light receiving portion 88 is located. Are arranged so as to be inclined with respect to the axis of the spindle 26, and the light from the second light emitting portion 84 is partially blocked by the second cutting blade 28b. The second light emitting unit 84 and the second light receiving unit 88 constitute second blade detecting means.

  A transparent protective plate 78 is attached to the first light emitting portion 76, a transparent protective plate 82 is attached to the first light receiving portion 80, a transparent protective plate 86 is attached to the second light emitting portion 84, and a second A transparent protective plate 90 is attached to the light receiving unit 88.

  The first light emitting unit 76 is connected to a first light emitting element 94 configured by a light emitting diode (LED), a laser diode (LD), or the like via an optical fiber (preferably a plastic optical fiber) 92. The first light receiving unit 80 is connected to a first light receiving element 98 including a photodiode (PD) or the like via an optical fiber 96.

  Similarly, the second light emitting unit 84 is connected to the second light emitting element 102 via the optical fiber 100. The second light receiving unit 88 is connected to the second light receiving element 106 via the optical fiber 104.

  When a new cutting blade 28 is mounted on the spindle 26, the adjusting screw 72 is rotated to move the moving block 74 in the vertical direction, and the light from the first light emitting unit 76 and the second light emitting unit 84 is transmitted to the first cutting blade. 28a and the second cutting edge 28b are set so as to be partially blocked.

  In the present embodiment, the first light emitting unit 76 is configured by the end of the optical fiber 92, the first light receiving unit 80 is configured by the end of the optical fiber 96, and the second light emitting unit 84 is configured by the end of the optical fiber 100, The second light receiving unit 88 is configured by the end of the optical fiber 104.

  The operation of the cutting blade detection mechanism 75 configured as described above will be described below. In a state where the cutting blade 28 is rotating, a controller (not shown) of the cutting apparatus 2 drives the first light emitting element 94 and the second light emitting element 102. As a result, light is emitted from the first light emitting unit 76 toward the first light receiving unit 80, and light is emitted from the second light emitting unit 84 toward the second light receiving unit 88.

  Of the light emitted from the first light emitting unit 76, light that is not blocked by the first cutting blade 28 a of the cutting blade 28 is received by the optical fiber 96 of the first light receiving unit 80. Therefore, when the first cutting edge 28a of the cutting blade 28 is not worn, the amount of light received by the first light receiving element 98 is small, and the amount of received light increases as it wears.

  Accordingly, when cutting is continued by the cutting blade 28, the current value generated by the first light receiving element 98 increases as time passes. That is, as the first cutting edge 28a wears, the amount of light received by the first light receiving element 98 increases, and the current value increases accordingly.

  Similarly, of the light emitted from the second light emitting unit 84, the light that is not blocked by the second cutting blade 28 b of the cutting blade 28 is received by the optical fiber 104 of the second light receiving unit 88. Therefore, when the second cutting edge 28b of the cutting blade 28 is not worn, the amount of light received by the second light receiving element 106 is small, and the amount of received light increases as it wears.

  Therefore, when cutting is continued with the cutting blade 28, the current value generated by the second light receiving element 106 increases with time. That is, as the second cutting edge 28b wears, the amount of light received by the second light receiving element 106 increases, and the current value generated by the second light receiving element 106 increases accordingly.

  When the first cutting edge 28a and / or the second cutting edge 28b are worn, either the current value of the first light receiving element 98 or the second light receiving element 106 reaches a predetermined current value, and the cutting blade 28 is used. When it is determined that the limit has been reached, the controller of the cutting device 2 displays the fact on the display means 6 and issues an alarm with a buzzer or the like to notify the operator. In response to this alarm, the operator replaces the cutting blade 28 with a new cutting blade.

  On the other hand, if the first cutting edge 28a or the second cutting edge 28b is chipped while the wafer W is being cut by the cutting blade 28, the first light receiving element 98 or the second light receiving element 106 receives light. Since the amount increases instantaneously, the current signal of the first light receiving element 98 or the second light receiving element 106 is increased instantaneously.

  Since the instantaneous increase of the current signal is displayed on the display means 6, the operator can recognize that the first cutting edge 28a or the second cutting edge 28b of the cutting blade 28 is chipped. Therefore, the operator replaces the cutting blade 28 with a new cutting blade.

  According to the cutting blade detection mechanism 75 of the above-described embodiment, the first light emitting unit 76 and the first light receiving unit 80 are positioned so as to sandwich the first cutting blade 28a, and the first light emitting unit 76 and the first light receiving unit 80 are arranged. The connecting optical axis is inclined with respect to the axis of the spindle 26, and the second light emitting unit 84 and the second light receiving unit 88 are positioned so as to sandwich the second cutting blade 28b, and the second light emitting unit 84 Since the optical axis connecting the second light receiving unit 88 is disposed to be inclined with respect to the axis of the spindle 26, the state of the individual cutting blades 28a and 28b of the multi-blade 28 can be detected independently. .

2 Cutting device 18 Chuck table 24 Cutting means 26 Spindle 28 Cutting blade 28a First cutting blade 28b Second cutting blade 68 Fixed block 72 Adjustment screw 74 Moving block 75 Cutting blade detection mechanism 76 First light emitting unit 80 First light receiving unit 84 Second light emitting unit 88 Second light receiving unit 78, 82, 86, 90 Transparent protective plates 92, 96, 100, 104 Optical fiber 94 First light emitting element 98 First light receiving element 102 Second light emitting element 106 Second light receiving element

Claims (1)

A chuck table for holding a workpiece, and a cutting blade in which a first cutting edge and a second cutting edge for cutting the workpiece held on the chuck table are arranged at a predetermined interval are provided on the spindle. A cutting blade detection mechanism used in a cutting apparatus equipped with a mounted cutting means,
First blade detecting means for detecting the state of the first cutting edge, and second blade detecting means for detecting the state of the second cutting edge,
In the first blade detecting means, the first light emitting part and the first light receiving part are positioned so as to sandwich the first cutting edge, and the optical axis connecting the first light emitting part and the first light receiving part is the spindle. It is arranged inclined with respect to the axis of
In the second blade detecting means, the second light emitting part and the second light receiving part are positioned so as to sandwich the second cutting edge, and the optical axis connecting the second light emitting part and the second light receiving part is the spindle. A cutting blade detection mechanism, wherein the cutting blade detection mechanism is arranged to be inclined with respect to the axis of the cutting blade.

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