JP2010076065A - Cutting apparatus, and rotating balance adjusting method of cutting blade - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cutting apparatus capable of easily adjusting the rotational balance of a cutting blade itself attached to a spindle. <P>SOLUTION: The cutting apparatus comprises a chuck table for holding a workpiece, and a cutting means in which an annular cutting blade for cutting the workpiece held by the chuck table is held by a mount flange and fixing nuts and attached to a spindle, and further comprises an amplitude detection mechanism for detecting the amplitude of the rotating cutting blade in the radial direction, a rotational period detection mechanism for detecting the rotational period of the cutting blade, an amplitude data preparing means for preparing the amplitude data based on the amplitude detected by the amplitude detection mechanism and the rotational period detected by the rotational period detection mechanism, a mass computing means for computing the mass of an object for adjustment to adjust the rotational balance of the cutting means based on the amplitude data, and a rotational balance adjusting mechanism to which the object for adjustment of the mass computed by the mass computing means is attached. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a cutting apparatus having a cutting means in which an annular cutting blade is mounted on a spindle, and a method for adjusting the rotational balance of the cutting blade.

  Workpieces such as semiconductor wafers in which a plurality of devices such as IC and LSI are formed on a silicon substrate, various ceramic substrates used in electronic components, resin substrates, glass substrates, etc., are divided into individual chips by a cutting device, The divided chips are widely used in various electronic devices.

  As a cutting device, a device called a dicer comprising a chuck table for holding a workpiece, an annular cutting blade for cutting the workpiece held on the chuck table, and a spindle on which the cutting blade is mounted. Is widely used.

  The cutting blade has a cutting blade in which, for example, diamond abrasive grains of about several μm are hardened by nickel plating or the like, and the cutting blade is sandwiched between a mount flange and a fixing nut and attached to the tip of the spindle. Cutting is performed by cutting the cutting blade into the workpiece while being rotated by the spindle at a high speed such as 20000 to 60000 rpm.

  In order to make it possible to attach and detach the cutting blade attached to the spindle, it is necessary to provide a play of about several μm between the inner diameter of the cutting blade and the boss portion of the mount flange to which the cutting blade is attached.

  For this reason, when the cutting blade is mounted on the spindle in a state where the rotation center of the spindle and the rotation center of the cutting blade do not completely coincide with each other, the rotation balance is lost and vibration occurs when the spindle rotates at a high speed. Will flutter. Therefore, normal cutting is not performed, and there is a risk that the workpiece may be chipped or cracked, and consequently the cutting blade or workpiece may be damaged.

  In order to remove the eccentric shake of the cutting blade mounted on the spindle, dressing work is performed widely in which the cutting blade is worn by cutting a dresser including general abrasive grains so as to approach a perfect circle.

  However, with a cutting blade having a high hardness or a cutting blade having a large thickness, it is difficult to produce a perfect circle even if a dressing operation is performed. Furthermore, in the case of a cutting blade having a V-shape formed at the tip of the cutting edge, the dressing operation cannot be performed in order to maintain the V shape, and the rotation balance has to be adjusted.

  Japanese Patent Laid-Open No. 2001-129743 discloses a rotation balance adjustment mechanism of a cutting apparatus that can easily perform precise balance adjustment without preparing a plurality of types of balance weights.

Also, a device for detecting the unbalanced position of the spindle by attaching an acceleration sensor to the spindle housing (for example, “Myself-1”, a product name manufactured by Omiya Kogyo Co., Ltd. located in 5-6-45 Daimoncho, Fukuyama City, Hiroshima Prefecture) ) Has been proposed to adjust the rotational balance of the cutting means.
JP 2001-129743 A

  However, the rotation balance adjustment mechanism of the cutting apparatus disclosed in Patent Document 1 is not provided with an amplitude detection mechanism that detects the radial amplitude of the cutting blade and a rotation period detection mechanism that detects the rotation period of the cutting blade. There is a problem that it is necessary to determine the degree of screwing of the balance weight screw to be inserted into the screw hole by a plurality of trials and errors, and it takes time to adjust the rotation balance.

  Further, the method of attaching the acceleration sensor to the housing has a problem that a dedicated device is required for adjusting the rotational balance and vibration of the spindle on which the cutting blade is actually mounted cannot be measured.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a cutting apparatus capable of easily adjusting the rotational balance of the cutting blade itself mounted on the spindle.

  According to the present invention, a chuck table for holding a workpiece, and a cutting means for attaching an annular cutting blade for cutting the workpiece held on the chuck table to a spindle by being sandwiched between a mount flange and a fixing nut. An amplitude detection mechanism for detecting a radial amplitude of the rotating cutting blade, a rotation period detection mechanism for detecting a rotation period of the cutting blade, and the amplitude detection mechanism An amplitude data creating means for creating amplitude data based on the amplitude and the rotation period detected by the rotation period detecting mechanism, and an adjustment object for adjusting the rotational balance of the cutting means based on the amplitude data Mass calculating means for calculating mass, and a rotation balance adjusting mechanism on which an object for adjusting the mass calculated by the mass calculating means is mounted. Cutting device is provided to symptoms.

  Preferably, the amplitude detection mechanism is disposed on one side of the cutting blade so as to irradiate the outer peripheral edge of the cutting blade, and disposed on the other side of the cutting blade so as to face the light emitting means. It includes a light receiving means and a photoelectric conversion means for converting the amount of light received by the light receiving means into a voltage signal.

  The amplitude data creating means creates amplitude data in the radial direction of the cutting blade based on the maximum value and the minimum value of the voltage value output from the photoelectric conversion means and the rotation period detected by the rotation period detection mechanism.

  Preferably, the rotation balance adjustment mechanism includes a plurality of screw holes formed at equal intervals in the circumferential direction of the fixing nut, and an adjustment screw that can be inserted into these screw holes, and the adjustment object is adjusted. Consists of screws. Preferably, the rotation period detection mechanism is constituted by an optical sensor or a magnetic sensor.

  According to the present invention, the amplitude data is created by the amplitude data creation means based on the amplitude detected by the amplitude detection mechanism and the rotation period detected by the rotation period detection mechanism. Can be easily adjusted.

  Therefore, it is possible to perform adjustment with higher accuracy than the conventional method of adjusting the rotation balance with the vibration data of the spindle housing. Further, a dedicated device for adjusting the rotation balance is not required, and the space of the device can be saved.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an appearance of a cutting apparatus 2 according to an embodiment of the present invention, which can divide a semiconductor wafer 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.

  As shown in FIG. 2, on the surface of the wafer W to be diced, the first street S1 and the second street S2 are formed orthogonally, and the first street S1 and the second street S2 A plurality of devices D are partitioned and formed on the wafer W.

  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 attracted 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 fixing means 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.

  On the left side of the alignment means 20, a cutting means 24 for cutting the wafer W held on the chuck table 18 is disposed. 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. 3, an exploded perspective view showing the relationship between the spindle and the mount flange 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 mount flange 36 includes a boss part (convex part) 38 and a fixing flange 40 formed integrally with the boss part 38, and a male screw 42 is formed on the boss part 38. Further, the mount flange 36 has a mounting hole 43.

  The mounting flange 36 is inserted into the tip small diameter portion 26b and the taper portion 26a of the spindle 26, and the nut 44 is screwed into the male screw 34 to be tightened, as shown in FIG. Attached to. A light shielding tape 45 is attached to the nut 44.

  FIG. 4 is an exploded perspective view showing the mounting relationship between the spindle 26 to which the mount flange 36 is fixed and the cutting blade 28. The cutting blade 28 is called a hub blade, and is configured by electrodepositing a cutting blade 50 in which diamond abrasive grains are dispersed in a nickel base material on the outer periphery of a circular base 46 having a circular hub 48.

  The mounting hole 52 of the cutting blade 28 is inserted into the boss portion 38 of the mount flange 36, and the fixing nut 54 is screwed onto the male screw 42 of the boss portion 38 and tightened, so that the cutting blade 28 is moved to the spindle 26 as shown in FIG. Attached to.

  Referring to FIG. 6, an enlarged perspective view of the cutting means 24 is shown. A blade cover 60 covers the cutting blade 28, and a cutting water nozzle (not shown) that extends along the side surface of the cutting blade 28 is attached to the blade cover 60. Cutting water is supplied to a cutting water nozzle (not shown) via the pipe 72.

  Reference numeral 62 denotes a detachable cover, which is attached to the blade cover 60 with screws 64. The detachable cover 62 has a cutting water nozzle 70 that extends along the side surface of the cutting blade 28 when attached to the blade cover 60. The cutting water is supplied to the cutting water nozzle 70 via the pipe 74.

  A blade detection block 66 is attached to the blade cover 60 with screws 68. A blade sensor (not shown) composed of a light emitting element and a light receiving element is attached to the blade detection block 66, and the state of the cutting blade 50 of the cutting blade 28 is detected by this blade sensor.

  When the cutting of the cutting edge 50 is detected by the blade sensor, the cutting blade 28 is replaced with a new cutting blade. Reference numeral 76 denotes an adjusting screw for adjusting the position of the blade sensor.

  The blade sensor can also serve as the amplitude detection mechanism of the present invention. When the blade sensor is used as the amplitude detection mechanism, the light emitting element and the light receiving element are attached with the cutting blade 50 of the cutting blade 28 sandwiched so that approximately half of the light beam from the light emitting element is blocked by the cutting blade 50.

  An optical sensor 78 having a light emitting element and a light receiving element is attached to the detachable cover 62. A light shielding tape 45 is affixed to the nut 44 that fixes the mount flange 36 to the spindle 26. The optical sensor 78 and the light shielding tape 45 constitute a rotation period detection mechanism. Instead of the light shielding tape 45, a part of the outer periphery of the nut 44 may be painted with black magic ink.

  Referring to FIG. 7, a second embodiment of the amplitude detection mechanism is shown. Reference numeral 60A denotes a blade cover. A slide cover 62A is slidably attached to the blade cover 60.

  An optical fiber 82 is attached to the blade cover 60A so that the light beam from the light emitting portion (end portion) 84 is blocked by the cutting blade 50 of the cutting blade 28 by approximately half. On the opposite side of the cutting blade 28, an optical fiber connected to the photodetector is attached so that the light receiving portion faces the light emitting portion 84.

  Reference numeral 86 denotes an adjusting screw for adjusting the positions of the light emitting part and the light receiving part with respect to the cutting blade 50 of the cutting blade 28. After the adjustment, the adjusted position is fixed by a fixing screw 88.

  Referring to FIG. 8, a perspective view of an amplitude detection mechanism 80A of the third embodiment is shown. The U-shaped member 92 of the amplitude detection mechanism 80A is mounted on a support member 90, and the support member 90 is disposed in the vicinity of the chuck table 18 of the cutting apparatus 2 shown in FIG.

  The U-shaped member 92 defines a blade entry portion 98 into which the cutting blade 28 enters, and the light emitting element 94 and the light receiving element 96 are attached to both sides of the blade entry portion 98. Reference numeral 100 denotes a cleaning water supply nozzle that supplies cleaning water to the cutting blade 28 inserted into the blade entry portion 98, and reference numeral 102 denotes an air supply nozzle that supplies air.

  In order to detect the radial amplitude of the cutting blade 28 by the amplitude detection mechanism 80A of the present embodiment, an X-axis feed mechanism and a Y-axis feed mechanism (not shown) are driven so that the cutting blade 28 enters the blade of the U-shaped member 92. Enter into section 98.

  Then, cleaning water is supplied from the cleaning water supply nozzle 100 to the cutting blade to clean the cutting blade, then air is supplied from the air supply nozzle 102 to blow off the cleaning water from the cutting blade 28, and the cutting blade is dried.

  When drying of the cutting blade 28 is completed, a Z-axis feed mechanism (not shown) is driven to adjust the height of the cutting blade 50 of the cutting blade 28, and approximately half of the light beam emitted from the light emitting element 94 is about 50%. To block. In this state, the cutting blade 28 is rotated at 20000 to 60000 rpm, and the radial amplitude of the cutting blade 28 is detected.

  Next, a method for adjusting the rotational balance of the cutting blade 28 using the rotation period detection mechanism 78 and the amplitude detection mechanism 80A of the third embodiment will be described with reference to FIGS. 9 to 12. FIG. FIG. 9 is a block diagram of the rotation balance adjusting mechanism.

  In FIG. 9, a rotation period detection mechanism 77 is configured by an optical sensor 78 having a light emitting portion 78 a and a light receiving portion 78 b connected to a light source 104 and a light shielding tape 45 attached to a nut 44. The rotation period 112 detected by the rotation period detection mechanism 77 is stored in the storage unit 106 and is used to create amplitude data described later.

  When the light emitting element 94 is driven by the drive circuit 108, a light beam is emitted from the light emitting element 94 and a part of the light beam is received by the light receiving element 96. Since the cutting blade 28 rotates at a high speed, radial vibration occurs, and the amount of light received by the light receiving element 96 changes according to the vibration of the cutting blade 28.

  The amount of light received by the light receiving element 96 is converted into a voltage signal by the photoelectric conversion means 110 such as a photodetector. In the amplitude data creating unit 114, the amplitude data in the radial direction of the cutting blade 28 is obtained based on the maximum value and the minimum value of the voltage value output from the photoelectric conversion unit 110 and the rotation period 112 detected by the rotation period detection mechanism 77. create.

  As shown in FIG. 10, the amplitude data includes amplitude data and angular position data of the cutting blade 28 at which the amplitude appears. In FIG. 10, reference numeral 118 indicates first amplitude data of the cutting blade 28 when the adjustment screw is not inserted into the adjustment screw insertion position 120 of the fixing nut 54. A plurality of adjustment screw insertion holes (not shown) are formed in the fixing nut 54 at regular intervals in the circumferential direction.

  Reference numeral 122 indicates amplitude data to be obtained when the adjustment screw is inserted into the adjustment screw insertion hole 120 when the rotational balance is not lost. Reference numeral 124 indicates second amplitude data obtained when the adjustment screw is inserted into the adjustment screw insertion hole 120.

  Reference numeral 126 denotes an amplitude necessary for canceling the first amplitude data 118. By generating the same amplitude as that of the first amplitude data on the opposite side of the first amplitude data 118 by 180 degrees, the rotational balance is corrected. The

  Hereinafter, with reference to the vector diagram shown in FIG. 11 corresponding to the amplitude data of FIG. 10, the mass of the adjusting screw necessary to cancel the first amplitude data 118 is calculated. The calculation of the mass of the adjusting screw is performed by the mass calculating means 116 in FIG. F1 corresponds to the first amplitude data 118, F3 corresponds to the second amplitude data 124, and F2 corresponds to the amplitude 122.

  In FIG. 11, when the first amplitude F1 is detected at the position of θ1 = 30 degrees and a 20 mg adjustment screw is inserted into the adjustment screw insertion position 120 of θ2 = 90 degrees, the second amplitude is at the position of θ3 = 60 degrees. The calculation is performed for the case where S3 is detected, the first amplitude F1 is 8 μm, and the second amplitude F3 is 13.84 μm.

F3 = F1 + F2 Therefore, F1 = F3-F2
Because F3 = 1.73F1 F2 = 20 mg
F3 = F1 cos θ5 + F2 cos θ4
・ 73F1 = F1cos30 ° + 20 ・ cos30 °
1.73F1-F1cos30 ° = 20 · cos30 °
F1 = (20 · cos 30 °) / (1.73−cos 30 °)
≒ 20
Therefore, the weight F1 of the adjusting screw to be inserted is calculated as F1≈20 mg.

  Therefore, in order to cancel F1, it is necessary to insert a 20 mg adjustment screw into the adjustment screw insertion hole of θ6 = 210 degrees rotated 180 degrees.

  When the cutting device has inherent vibrations, the amplitude at the time of low rotation is detected in advance and the amplitude data 128 is stored in advance as shown in FIG. By subtracting the time amplitude data 128, a highly accurate rotation balance adjustment method is possible.

It is an external appearance perspective view of a cutting device. It is a surface side perspective view of the semiconductor wafer supported by the annular frame via the dicing tape. It is a disassembled perspective view which shows the relationship between a spindle unit and the mount flange 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 an expansion perspective view of a cutting means. It is a figure which shows 2nd Embodiment of an amplitude detection mechanism. It is a figure which shows 3rd Embodiment of an amplitude detection mechanism. It is a block diagram of a rotation balance adjustment mechanism. It is a figure which shows an example of amplitude data. FIG. 11 is a vector diagram corresponding to the amplitude data of FIG. 10. It is a figure which shows the relationship between the 1st amplitude data at the time of low rotation, and the 2nd amplitude data at the time of performing rotation balance adjustment.

Explanation of symbols

18 Chuck table 26 Spindle 28 Cutting blade 36 Mount flange 44 Nut 45 Light shielding tape 54 Fixed nut 77 Rotation period detection mechanism 78 Optical sensor 80, 80A Amplitude detection mechanism 82 Optical fiber 84 Light emitting part 94 Light emitting element 96 Light receiving element 98 Blade entry part 114 Amplitude data creation means 116 Mass calculation means

Claims (5)

A cutting apparatus comprising: a chuck table for holding a workpiece; and a cutting means in which an annular cutting blade for cutting the workpiece held on the chuck table is sandwiched between a mount flange and a fixing nut and mounted on a spindle. Because
An amplitude detection mechanism for detecting the radial amplitude of the rotating cutting blade;
A rotation period detection mechanism for detecting a rotation period of the cutting blade;
Amplitude data creating means for creating amplitude data based on the amplitude detected by the amplitude detection mechanism and the rotation period detected by the rotation period detection mechanism;
A mass computing means for computing the mass of the adjusting object for adjusting the rotational balance of the cutting means based on the amplitude data;
A rotation balance adjusting mechanism to which an object for adjusting the mass calculated by the mass calculating means is mounted;
A cutting apparatus comprising: The amplitude detection mechanism is:
A light emitting means disposed on one side of the cutting blade so as to irradiate the outer peripheral edge of the cutting blade;
A light receiving means disposed on the other side of the cutting blade opposite the light emitting means;
Photoelectric conversion means for converting the amount of light received by the light receiving means into a voltage signal,
The amplitude data creation means creates the amplitude data in the radial direction of the cutting blade based on the maximum and minimum values of the voltage value output from the photoelectric conversion means and the rotation period detected by the rotation period detection mechanism. The cutting device according to claim 1.   The rotation balance adjustment mechanism includes a plurality of screw holes formed at equal intervals in the circumferential direction of the fixing nut, and an adjustment screw that can be inserted into the screw hole, and the adjustment object is formed from the adjustment screw. The cutting apparatus according to claim 1 or 2, wherein the cutting apparatus is configured.   The cutting device according to any one of claims 1 to 3, wherein the rotation period detection mechanism includes an optical sensor or a magnetic sensor. The cutting apparatus according to claim 3, wherein the rotation balance is adjusted by adjusting the rotation balance of the cutting blade.
A first amplitude detection step for forming first amplitude data based on a first amplitude in a radial direction during rotation of the cutting blade detected by the amplitude detection mechanism and a rotation period detected by the rotation period detection mechanism; ,
A first adjustment screw insertion step of inserting a first adjustment screw having a known mass into a screw hole at a predetermined position among the plurality of screw holes after performing the first amplitude detection step;
After performing the first adjustment screw insertion step, based on the second amplitude in the radial direction during rotation of the cutting blade detected by the amplitude detection mechanism and the rotation period detected by the rotation period detection mechanism, A second amplitude detecting step for forming second amplitude data;
Based on the difference between the first amplitude and the second amplitude, and the mass of the first adjustment screw, the required mass calculation for calculating the mass of the adjustment screw to be inserted to cancel the first amplitude. Steps,
After removing the first adjustment screw, the second mass of the mass calculated in the required mass calculation step is placed at a screw hole position 180 degrees opposite to the first amplitude position detected in the first amplitude detection step. A second adjustment screw insertion step for inserting the adjustment screw;
A rotation balance adjustment method comprising:

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