JP2016127060A - Cutting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cutting device that can minimize damage of a cutting blade and holding means due to the contact between a cutting blade and a holding face in a cutting process.SOLUTION: In a cutting device 1, a holding face 300a of holding means 3 has electrical conductivity, a cutting blade 631 of a cutting blade 63 has electrical conductivity, and the holding means 3 and cutting means 6 are electrically connected to each other, thereby providing a circuit 12 in which current flows when the holding face 300a of the holding means 3 comes into contact with the cutting blade 631 of the cutting blade 63. The cutting device 1 is provided with control means 14 for monitoring current flow of the circuit 12, and notifying that when current flows, the cutting blade 631 of the cutting blade 63 cuts a dicing tape T together with a wafer W and contacts the holding face 300a of the holding means 3, whereby the control means 14 quickly notifies the contact between the holding face 300a and the cutting blade 631 to an operator.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a cutting apparatus provided with a cutting blade for cutting a wafer.

  A wafer formed by dividing a plurality of devices such as IC, LSI, etc. by dividing lines (streets) and formed on the surface is divided into individual devices by a cutting machine equipped with a rotatable cutting blade, and used for various electronic devices. Has been. The cutting device used here is a holding means having a holding surface for holding a wafer adhered to a dicing tape, a cutting means for rotatably supporting a cutting blade for cutting the wafer held by the holding means, A cutting feed means for relatively cutting and feeding the holding means and the cutting means, an index feeding means for relatively indexing and feeding the holding means and the cutting means, and a relative relationship between the holding means and the cutting means. It is comprised at least from the notch feed means which cuts and feeds automatically, and the control means which controls these (for example, refer patent document 1).

JP 2001-7058 A

  However, when the operator incorrectly controls the cutting feed means, the cutting blade position of the cutting blade is set to a position beyond the holding surface of the holding means, or the holding surface of the holding means is slightly inclined and the holding surface is not horizontal. In this case, the cutting blade of the cutting blade cuts through the wafer and the dicing tape, so that the cutting blade comes into contact with the holding surface of the holding means, and both the cutting blade and the holding means are damaged. .

  The present invention has been proposed in view of the above problems, and when there is an error in the control of the cutting feed means or when the holding surface of the holding means is inclined, the cutting blade and the holding surface are It is an object to minimize damage to the cutting blade and the holding means when contact occurs.

  In order to achieve the above object, the present invention supports a holding means having a holding surface for holding a wafer attached to a dicing tape and a cutting blade for cutting the wafer held by the holding means in a rotatable manner. Cutting means, cutting feed means for relatively cutting and feeding the holding means and the cutting means, index feeding means for relatively indexing and feeding the holding means and the cutting means, the holding means and the cutting A cutting apparatus comprising at least a cutting and feeding means for relatively cutting and feeding means, and a control means, wherein the holding surface of the holding means has conductivity, and the cutting blade of the cutting blade has conductivity. And a circuit through which an electric current flows when the holding means and the cutting means are electrically connected and the holding surface of the holding means and the cutting blade of the cutting blade come into contact with each other, and the control means includes the circuit Power of Monitoring the flow, a cutting device for indicating that the cutting edge of the cutting blade when the current flows in the circuit is by cutting the dicing tape with the wafer in contact with the holding surface of the holding means.

  In the cutting apparatus, the holding surface of the holding unit has conductivity, the cutting blade of the cutting blade has conductivity, and the holding unit and the cutting unit are electrically connected to each other. And a circuit through which a current flows when the cutting blade contacts the cutting blade, and the control means monitors the current flow of the circuit, and when the current flows, the cutting blade of the cutting blade and the wafer are dicing tape. Is informed that the contact has been made with the holding surface of the holding means. Therefore, when there is an error in the control of the cutting feed means by the operator or when the holding surface of the holding means is inclined, the cutting blade of the cutting blade cuts through the wafer and the dicing tape and reaches the holding surface. Even if contact is made, the operator can immediately know that contact has been made. Therefore, for example, immediately after the contact, the cutting blade is pulled up to a position where the cutting blade of the cutting blade does not contact the holding surface of the holding device, whereby damage to the cutting blade and the holding device can be minimized.

It is a perspective view which shows the wafer supported by the annular frame via the dicing tape. It is a perspective view which shows an example of the external appearance of a cutting device. It is a perspective view which shows an example of the internal structure of a cutting device. It is a perspective view which shows the structure by which the cutting means and the holding means are electrically connected by the circuit. It is a perspective view which shows the state which the cutting blade and holding surface of the cutting blade contacted during cutting. It is a schematic diagram which shows the positional relationship of the front-end | tip of a cutting blade of a cutting blade, and a wafer. It is a side view which expands and shows the state which the cutting blade of the cutting blade and the holding surface of the holding means contacted.

  The wafer W subjected to the cutting process shown in FIG. 1 is a wafer cut by the cutting apparatus 1 shown in FIG. 2, for example, a semiconductor wafer. On the wafer upper surface Wa, a lattice-like shape partitioned by streets S is used. Many devices D are formed in the region. The wafer bottom surface Wb is attached to the attaching surface Ta of the dicing tape T, and the outer peripheral portion of the dicing tape T is attached to the annular frame F. As a result, the wafer W to be cut is supported by the annular frame F via the dicing tape T. The shape of the wafer W is not particularly limited, and the type of the wafer W is not limited to the semiconductor wafer.

  A cutting apparatus 1 shown in FIG. 2 is an apparatus that performs cutting with the cutting means 6 on the wafer W held by the holding means 3.

  On the front side of the cutting apparatus 1, an operating means 27 for an operator to input processing conditions and the like to the cutting apparatus 1 and a wafer cassette 20 for storing the wafer W are provided. The wafer cassette 20 is installed on an elevating mechanism 21 that reciprocates in the Z-axis direction, and a plurality of wafers W are accommodated in the wafer cassette 20. Behind the wafer cassette 20, a loading / unloading means 22 for unloading the wafer W before cutting from the wafer cassette 20 and loading the wafer W after cutting into the wafer cassette 20 is disposed. Between the wafer cassette 20 and the carry-in / out means 22, a temporary placement area 23 on which the wafer W to be carried in / out is temporarily placed is provided. In the temporary placement area 23, the wafer W is fixedly placed. Positioning means 24 for positioning to the position is provided.

  The holding means 3 shown in FIG. 2 includes a chuck table 30 and four fixing means 33 that are arranged around the chuck table 30 and fix the annular frame F. The holding means 3 can reciprocate in the X-axis direction between an attachment / detachment area A where the wafer W is attached / detached and a cutting area B where the wafer W is cut by the cutting means 6. An alignment means 60 for detecting the street S to be cut by the wafer W is disposed above the movement path of the holding means 3.

  The chuck table 30 shown in FIG. 2 includes a suction unit 300 that sucks the wafer W and a frame body 301 that supports the suction unit 300. The adsorption unit 300 is made of a porous member having conductivity, such as porous carbon or porous aluminum. The suction unit 300 communicates with a suction source (not shown), and sucks and holds the wafer W on a holding surface 300 a that is an exposed surface of the suction unit 300. The frame 301 is made of a conductive metal such as stainless steel or aluminum.

  The alignment unit 60 includes an imaging unit 600 that images the wafer upper surface Wa, and can detect the street S to be cut by image processing such as pattern matching based on the image acquired by the imaging unit 600. The image acquired by the imaging unit 600 is displayed on the display unit 16 such as a monitor, for example. The imaging unit 600 is, for example, a camera using a CCD image sensor, but is not limited thereto.

  As shown in FIG. 2, in the vicinity of the temporary placement area 23, a first transport means 25 a having a turning arm for transporting the wafer W is disposed between the temporary placement area 23 and the holding means 3. . The wafer W supported by the annular frame F is carried out to the temporary placement area 23 by the carry-in / out means 22 and is adsorbed by the first transport means 25a to be moved from the temporary placement area 23 to the chuck table 30 located in the attachment / detachment area A. It is conveyed and sucked and held by the holding surface 300a, and the four fixing means 33 fix the annular frame F.

  On the rear side of the cutting device 1, a cleaning means 26 for cleaning the wafer W after cutting is disposed. Above the cleaning unit 26, a second transport unit 25b that sucks and transports the wafer W after cutting from the holding unit 3 to the cleaning unit 26 is disposed.

  In the vicinity of the alignment means 60 in the cutting area B, a cutting means 6 for cutting the wafer W held on the chuck table 30 is disposed. The cutting means 6 is integrated with the alignment means 60, and both move in the Y-axis direction and the Z-axis direction in conjunction with each other.

  As shown in FIG. 3, the cutting means 6 includes a metal spindle 61 having a rotation axis in a direction (Y-axis direction) orthogonal to the horizontal direction with respect to the X-axis direction, and a housing that rotatably supports the spindle 61. 62 and a cutting blade 63 which is fixed to the spindle 61 and is rotatable, and is driven by the index feed means 7 and the cut feed means 8 so as to be movable in the Y-axis direction and the Z-axis direction.

  3 includes a ball screw 50 having an axis in the X-axis direction, a pair of guide rails 51 arranged in parallel to the ball screw 50, a motor 52 that rotates the ball screw 50, an internal A nut is engaged with the ball screw 50, and a bottom portion is constituted by a movable plate 53 that is in sliding contact with the guide rail 51. When the motor 52 rotates the ball screw 50, the movable plate 53 is guided by the guide rail 51 and moves in the X-axis direction, and the holding means 3 disposed on the movable plate 53 moves the movable plate 53. The holding means 3 is cut and fed by moving in the X-axis direction along with the movement. A cover member 31 is connected to the periphery of the chuck table 30, and a rotating means 32 for rotating the chuck table 30 is connected to the lower portion of the chuck table 30. The rotating means 32 is fixed to the movable plate 53 and moves with the movable plate 53 in the X-axis direction.

  3 includes a ball screw 70 having an axis in the Y-axis direction, a pair of guide rails 71 arranged in parallel to the ball screw 70, a motor 72 for rotating the ball screw 70, and an internal The nut is engaged with the ball screw 70, and the bottom part is composed of a movable part 73 that is in sliding contact with the guide rail 71. When the motor 72 rotates the ball screw 70, the movable portion 73 is guided by the guide rail 71 and moves in the Y-axis direction, and the cutting means 6 moves in the Y-axis direction as the movable portion 73 moves. By doing so, the cutting means 6 is indexed and fed to the holding means 3.

  3 includes a ball screw 80 having an axis in the Z-axis direction, a pair of guide rails 81 arranged in parallel to the ball screw 80, a motor 82 for rotating the ball screw 80, an internal When the nut 82 is screwed into the ball screw 80 and the side portion is in sliding contact with the guide rail 81, the motor 82 rotates the ball screw 80. As a result, the lifting portion 83 is guided by the guide rail 81. The cutting means 6 reciprocating in the Z-axis direction and simultaneously reciprocating in the Z-axis direction of the cutting means 6 connected to the elevating unit 83 causes the cutting means 6 to be cut into the holding means 3.

  The cutting blade 63 shown in FIG. 4 is, for example, an electroformed hub blade, which is formed by electrodepositing a cutting blade 631 on the periphery of a base 630 formed in a disk shape, and is fixed to the spindle 61 by a nut 65. Has been. The cutting blade 631 has conductivity. The cutting blade 63 is formed by, for example, fixing diamond abrasive grains having a particle diameter of about 2 to 4 μm to a side surface of a disk-shaped base made of aluminum by nickel plating to a thickness of about 20 μm, and etching and removing the outer peripheral portion of the base. It is formed by protruding a 2 to 3 mm cutting edge. The cutting blade 63 is not limited to the electroformed hub blade, and may be, for example, a washer type cutting blade having no base as long as it has conductivity.

  A pair of cutting fluid nozzles 64 that supply cutting fluid to the processing point of the cutting blade 631 with respect to the wafer W are provided on the front and rear sides of the cutting blade 631 in the Y-axis direction. The cutting fluid ejected from the cutting fluid nozzle 64 flows from the cutting fluid inlet 640 and cools the contact portion between the cutting edge 631 and the wafer W.

  As shown in FIG. 4, in the cutting apparatus 1, a current flows when the holding unit 3 and the cutting unit 6 are electrically connected and the holding surface 300 a of the holding unit 3 and the cutting blade 631 of the cutting blade 63 come into contact with each other. The current flow of the circuit 12 and the circuit 12 is monitored, and the cutting blade 631 of the cutting blade 63 removes the wafer W and the dicing tape T when the current flows as a result of the holding surface 300a and the cutting blade 631 coming into contact and conducting. Control means 14 is provided for notifying an operator or the like of cutting and contact with the holding surface 300a of the holding means 3.

  The circuit 12 includes a power source 120. For example, when the negative electrode of the power source 120 is connected to the frame body 301, the suction unit 300 supported in contact with the frame body 301 is electrically connected to the negative electrode of the power source 120. ing. On the other hand, the positive electrode of the power source 120 is connected to a spindle 61 provided in the cutting means 6.

  The control unit 14 is connected to an arbitrary position of the circuit 12 and includes, for example, a central processing unit (CPU), a memory, an input interface, an output interface, and the like. The control means 14 constantly monitors the current flow of the circuit 12 via the input interface, and outputs a detection signal from the output interface of the control means 14 to the display means 16 and the alarm buzzer 18 when the current flow is detected. Thus, the operator is informed that the cutting blade 631 of the cutting blade 63 is in contact with the holding surface a300 of the holding means 3.

  When cutting the street S of the wafer W shown in FIG. 1 using the cutting device 1 shown in FIG. 2 and dividing it into devices D, the wafer W is circulated through the dicing tape T by the loading / unloading means 22. In the state supported by F, the wafer cassette 20 is carried out to the temporary storage area 23. Then, after the wafer W is positioned at a predetermined position by the alignment means 24 in the temporary placement area 23, the first transport means 25 a sucks the wafer W and moves the wafer W from the temporary placement area 23 to the chuck table 30. Move. Next, the annular frame F is fixed by the fixing portion 33, and the wafer W is also sucked on the holding surface 300 a, whereby the wafer W is held by the holding means 3.

  After the wafer W is held by the holding means 3, the cutting feed means 5 shown in FIG. 3 sends the wafer W held by the holding means 3 in the −X direction, the wafer upper surface Wa is imaged by the imaging means 600 and cut. The position of the street S to be detected is detected. As the street S is detected, the cutting means 6 is driven in the Y-axis direction by the index feed means 7 shown in FIG. 3, and the street S to be cut and the cutting blade 63 are aligned in the Y-axis direction. Is called.

  Next, the holding means 3 is further fed in the −X direction, and the cutting blade 63 is rotated at a high speed, and the cutting feed means 8 shown in FIG. 3 lowers the cutting means 6 in the −Z direction to cut the street S. To do.

  When the wafer W advances in the -X direction to a predetermined position in the X-axis direction where the cutting blade 63 finishes cutting the street S, the cutting feed means 5 stops the cutting feed of the wafer W once, and the cutting feed means 8 turns the cutting blade. 63 is moved away from the wafer W, and then the cutting feed means 5 sends the holding means 3 in the + X direction to return it to the original position. Then, as shown in FIG. 5, all the streets S in the same direction are cut by sequentially performing the same cutting while indexing and feeding the cutting blade 63 in the Y-axis direction at intervals of the adjacent streets S.

  Here, in order to completely cut the wafer W and not damage the holding surface 300a, the position of the lower end in the Z-axis direction of the cutting blade 631 of the cutting blade 63 at the time of cutting is as shown in FIG. Must be set to a position Z3 in the Z-axis direction that reaches the dicing tape T and does not reach the holding surface 300a. The value of the position Z3 is input as control information for the cutting feed unit 8 when the operator operates the operation unit 27, for example. However, for example, the operator mistakenly sets the value for the cutting feed means 8, and the position of the lower end in the Z-axis direction of the cutting blade 631 of the cutting blade 63 at the time of cutting is, for example, as shown in FIG. When the position is set at the lower position Z1 in the Z-axis direction, the cutting blade 631 cuts the dicing tape T together with the wafer W to come into contact with the holding surface 300a as shown by the solid line in FIG. Here, the holding surface 300 a is in contact with the frame body 301, and the suction unit 300 and the frame body 301 have conductivity, and the circuit 12 is connected to the frame body 301. Further, the cutting blade 631 has conductivity, the cutting blade 631 is fixed to the conductive base 630, the base 630 is fixed in contact with the conductive spindle 61, and the circuit 12 is connected to the spindle 61. Has been. Therefore, when the cutting blade 631 comes into contact with the holding surface 300a, a closed circuit is formed, and the circuit 12 is electrically connected and current flows. When the current flows through the circuit 12, as shown in FIG. 5, the control means 14 monitoring the current flow sends a detection signal from the control means 14 to the display means 16 and the alarm buzzer. A warning message is displayed, and at the same time, the alarm buzzer 18 issues a warning sound.

  When the operator knows the contact between the cutting blade 631 and the holding surface 300a by displaying the warning text on the display means 16 and issuing the warning sound from the warning buzzer 18, the operator operates the operating means 27 shown in FIG. Then, the cutting feed means 8 is driven to raise the cutting means 6 in the + Z direction, and the position of the lower end of the cutting blade 631 of the cutting blade 63 is set to a position Z2 above the wafer upper surface Wa of the wafer W in the Z-axis direction. . Next, the cutting means 5 feeds the holding means 3 in the + X direction and pulls it back to the original position of the attachment / detachment area A shown in FIG. After the holding means 3 returns to the original position, the operator checks the cutting blade 63 and the holding means 3 for damage.

  As described above, in the cutting apparatus 1, when the holding surface 300 a having conductivity and the cutting blade 631 having conductivity are brought into contact with each other, a current immediately flows in the circuit 12, and the control unit 14 automatically Since the warning text is displayed on the display means 16 and the warning is issued by the alarm buzzer 18, the operator can easily grasp immediately after the contact that the cutting blade 631 and the holding surface 300a are in contact with each other. Damage to the cutting blade 631 of the 300a and the cutting blade 63 is minimized, and the necessity of exchanging the cutting blade 63 and the holding means 3 can be minimized.

  Before resuming the cutting process of the wafer W by the cutting device 1, the operating means 27 is operated, and the cutting depth (the position of the lower end in the Z-axis direction of the cutting blade 631) with respect to the cutting feed means 8 is a correct value. Correct to Z3. Then, the cutting feed means 5 performs the cutting feed in the −X direction of the wafer W held by the holding means 3 and the alignment of the street S to be cut by the index feeding means 7 and the cutting blade 63 in the Y-axis direction. Thereafter, the cutting blade 63 is rotated at a high speed, the holding means 3 is further fed in the −X direction, and the cutting feed means 8 lowers the cutting blade 63 in the −Z direction to cut the street S. Then, all the streets S in the same direction are cut by sequentially performing the same cutting while indexing and feeding the cutting blade 63 in the Y-axis direction at intervals of the adjacent streets S. Further, when the same cutting is performed after the chuck table 30 is rotated 90 degrees by the rotating means 32, all the streets S are cut vertically and horizontally.

  After all the streets S have been cut vertically and horizontally, the second transport means 25b sucks the wafer W and transports it from the holding means 3 to the cleaning means 26 in the attachment / detachment area A shown in FIG. The wafer W is cleaned at.

  Even after detecting contact between the cutting blade 631 and the holding surface 300a, the control means 14 continues to monitor the circuit 12, and the cutting feed means 8 pulls up the cutting means 6 in the + Z direction. When the control unit 14 detects that contact with the holding surface 300a is no longer detected, the cutting unit 6 stops pulling up in the + Z direction, and the lower end of the cutting blade 631 is above the holding surface 300a and from the wafer bottom surface Wb. Cutting may be continued while maintaining a lower position (a position indicated by a two-dot chain line in FIG. 7).

  Further, not only when the position of the lower end in the Z-axis direction of the cutting blade 631 of the cutting blade 63 during cutting is set incorrectly, the cutting blade 631 is held by the holding surface 300a because the holding surface 300a of the holding means 3 is inclined. Similarly, the control means 14 detects the contact between the cutting blade 631 and the holding surface 300a. If such contact is detected, the lower end position of the cutting edge 631 in the Z-axis direction is reset after the cutting means 6 is retracted to a position where the cutting edge 631 does not contact the wafer W, as described above. Or the cutting is continued with the cutting means 6 raised so that the cutting edge 631 does not come into contact with the wafer W.

  As described above, when there is an error in the control of the cutting feed means by the operator or when the holding surface of the holding means is inclined, the cutting blade of the cutting blade penetrates the wafer and the dicing tape to the holding surface. Even if it comes into contact, the operator can immediately know that it has touched. Therefore, damage to the cutting blade and the holding means can be minimized by pulling the cutting means up to a position where the cutting blade of the cutting blade does not contact the holding surface of the holding means immediately after contact.

1: Cutting device 12: Circuit 14: Control means 16: Display means 18: Alarm buzzer 20: Wafer cassette 21: Lifting mechanism 22: Loading / unloading means 23: Temporary placement area
24: Positioning means 25a: First conveying means 25b: Second conveying means 26: Cleaning means 27: Operating means 3: Holding means 30: Chuck table 300: Suction unit 300a: Holding surface
301: Frame 31: Cover member 32: Rotating means 33: Fixing means 5: Cutting feed means 50: Ball screw 51: Guide rail 52: Motor 53: Movable plate
6: Cutting means 60: Alignment means 600: Imaging means
61: Spindle 62: Housing 64: Cutting fluid nozzle 640: Cutting fluid inlet
65: Nut 63: Cutting blade 630: Base 631: Cutting blade 7: Indexing feeding means 70: Ball screw 71: Guide rail 72: Motor 73: Movable plate
8: Cutting feed means
80: Ball screw 81: Guide rail 82: Motor 83: Elevating part W: Wafer Wa: Wafer top surface Wb: Wafer bottom surface S: Street D: Device F: Ring frame T: Dicing tape Ta: Adhering surface A: Detachable area B: Cutting area Z1: Position Z2: Position Z3: Position

Claims (1)

Holding means having a holding surface for holding the wafer attached to the dicing tape, cutting means for rotatably supporting a cutting blade for cutting the wafer held by the holding means, the holding means and the cutting means Cutting feed means for relatively cutting and feeding, indexing feeding means for relatively indexing and feeding the holding means and the cutting means, and cutting feed means for relatively cutting and feeding the holding means and the cutting means A cutting device comprising at least a control means,
The holding surface of the holding means has conductivity,
The cutting blade of the cutting blade has conductivity,
A circuit through which an electric current flows when the holding means and the cutting means are electrically connected and the holding surface of the holding means comes into contact with the cutting blade of the cutting blade;
The control means monitors the current of the circuit, and informs that the cutting blade of the cutting blade cuts the dicing tape together with the wafer and contacts the holding surface of the holding means when the current flows through the circuit. apparatus.

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