JP2006278869A - Wafer cutting method and cutting apparatus - Google Patents

Abstract

When a wafer is cut using two or more cutting blades, even if some of the cutting blades are defective, the cutting is continued so as not to lower the productivity.
In a wafer cutting method of cutting a wafer W by applying a first cutting means 3 and a second cutting means 4 to a wafer W held on a chuck table 2, the first cutting means is provided. When a failure occurs in either the third cutting means 4 or the second cutting means 4, the cutting means in which the failure has occurred is retracted from the wafer W, and the cutting of the wafer W is continued by another cutting means in which no failure has occurred. Therefore, productivity is not lowered.
[Selection] Figure 1

Description

  The present invention relates to a method of cutting a wafer using two or more cutting blades, and a cutting apparatus that can be used to implement the method.

  A wafer formed by dividing a plurality of devices such as ICs and LSIs by the planned separation line is divided into individual devices by cutting the planned separation line using a cutting blade provided in the cutting apparatus, and is used for various electronic devices. It's being used.

  Usually, in a cutting machine, a wafer is held on a chuck table, and a planned separation line formed on the wafer is imaged and detected, and cutting is performed at a high speed to the detected separation line while moving the chuck table holding the wafer. The blade is cut to separate the scheduled separation line. After that, the separation scheduled lines are sequentially cut while the cutting blade is indexed at intervals of the separation scheduled lines, and the device is divided into devices precisely and efficiently.

  In addition, since a large number of scheduled separation lines are formed vertically and horizontally, a cutting device having two cutting blades is used, and two cutting blades are applied to one wafer to improve cutting productivity. Has also been put into practical use (see, for example, Patent Document 1).

Japanese Patent No. 3493282

  However, in a cutting machine having two or more cutting blades, if some of the cutting blades are worn or damaged, or if the cutting position is displaced, it becomes necessary to replace or adjust the cutting blade in which the failure has occurred. Therefore, the chuck table must be stopped and the cutting with other cutting blades that do not have a defect must be interrupted, so that the entire cutting is interrupted until the defect is resolved by replacing the cutting blade, etc. There is a problem that decreases.

  Therefore, the problem to be solved by the present invention is that when cutting a wafer using two or more cutting blades, even if some of the cutting blades fail, the cutting is continued, thereby improving productivity. It is to prevent it from being lowered.

  A wafer cutting method according to the present invention includes a chuck table for holding a workpiece, a first cutting means including at least a first cutting blade for cutting the workpiece held on the chuck table, and a second cutting means. And a second cutting means including a second cutting blade, and the wafer is cut by causing the first cutting means and the second cutting means to act on the wafer separation scheduled line held on the chuck table. When a failure occurs in either the first cutting means or the second cutting means, the cutting means in which the failure has occurred is retracted from the wafer, and no failure has occurred. The wafer is continuously cut by other cutting means. Since at least the first cutting means and the second cutting means are included, there may be three or more cutting means. Defects are all factors that must stop cutting, such as wear, breakage, clogging, misalignment, etc. of the cutting blade.

A cutting apparatus according to the present invention is an apparatus suitable for carrying out the above-described wafer cutting method, and includes a chuck table for holding a workpiece, and a first cutting for cutting the workpiece held on the chuck table. A first cutting means having a blade; a second cutting means having a second cutting blade for cutting a workpiece held on the chuck table; and a first for controlling the first cutting means. Control means, second control means for controlling the second cutting means, first fault detecting means for detecting faults in the first cutting means and notifying the first control means of fault information; And at least a second defect detection means for detecting a defect in the second cutting means and notifying the second control means of the defect information,
When a defect detection unit detects that a failure has occurred in any of the cutting means, and when the defect detection unit notifies the corresponding control unit of the information on the defect, the control unit has the cutting unit in which the defect has occurred. And the other control means continues cutting with the corresponding cutting means.

  The cutting apparatus includes a cutting information exchanging means for exchanging cutting information between at least the first control means and the second control means, and when any of the cutting means malfunctions, the malfunction occurs. The cutting information of the cutting means is transmitted from the control means for controlling the cutting means to the other control means via the cutting information exchanging means, and the other control means considers the received cutting information, and the cutting in which the trouble has occurred. It is preferred that the means perform the cutting to be performed. An example of the defect detection means is a blade monitoring means for monitoring the wear and damage of the cutting blade, for example.

  In the wafer cutting method and the cutting apparatus according to the present invention, it is possible to retreat the defective cutting means, continue the wafer cutting using the defective cutting means, and interrupt the cutting operation. This improves productivity. In addition, since the cutting means in which the defect has occurred is retracted, the cutting of the defective cutting means can be performed by replacing, adjusting, or repairing the defective cutting means while the cutting means in which the defect has not occurred is being cut. It can be resolved early.

  In addition, when a cutting information exchanging means for exchanging cutting information among a plurality of control means for controlling the cutting means is provided, other cutting means may perform cutting that should be originally performed by the cutting means in which the malfunction occurred. it can.

  The cutting device 1 shown in FIG. 1 is a so-called two-spindle cutting device that sucks and holds a workpiece on the chuck table 2 and performs indexing feed while the chuck table 2 reciprocates in the cutting feed direction (X-axis direction). The workpiece is cut by the action of the first cutting means 3 and the second cutting means 4 that move in the direction (Y-axis direction) and the cutting feed direction (Z-axis direction).

  The chuck table 2 is driven by the cutting feed means 5 and is movable in the X-axis direction. The cutting feed means 5 is formed on an X-axis guide rail 50 disposed in the X-axis direction, an X-axis movement base 51 slidably supported on the X-axis guide rail 50, and an X-axis movement base 51. An X-axis ball screw 52 that is screwed onto a nut (not shown), an X-axis pulse motor 53 that rotationally drives the X-axis ball screw 52, and a chuck table 2 that is fixed to the X-axis moving base 51 and is rotatably supported. The X-axis moving base 51 and the supporting base 54 move in the X-axis direction when the X-axis ball screw 52 is rotated by being driven by the X-axis pulse motor 53 to move the chuck table 2. Is also configured to move in the X-axis direction.

  The first cutting means 3 and the second cutting means 4 are driven by the first index feeding means 6 and the second index feeding means 7 and are movable in the Y-axis direction, respectively. The feeding means 6 and the second index feeding means 7 are disposed on a wall portion 60 provided in the Y-axis direction so as not to hinder the movement of the chuck table 2.

  The first index feeding means 6 includes a Y-axis guide rail 61 disposed in the Y-axis direction on the side surface of the wall portion 60, and a first Y-axis ball screw 62 disposed in parallel with the Y-axis guide rail 61. The first Y-axis pulse motor 63 connected to the first Y-axis ball screw 62 and a linear scale 64 are generally configured. The Y-axis guide rail 61 slidably supports the first support portion 65, and a nut (not shown) provided in the first support portion 65 is screwed into the first Y-axis ball screw 62. ing. The first support 65 is moved in the Y-axis direction by being driven by the first Y-axis pulse motor 63 and rotating the first Y-axis ball screw 62. The position of the first support portion 65 in the Y-axis direction is measured by the linear scale 64 and is used for precise control of the position in the Y-axis direction.

  On the other hand, the second index feeding means 7 is connected to the Y-axis guide rail 61, the second Y-axis ball screw 70 arranged in parallel with the Y-axis guide rail 61, and the second Y-axis ball screw 70. The second Y-axis pulse motor 71 and a linear scale 64 are generally configured. The Y-axis guide rail 61 slidably supports the second support portion 72, and a nut (not shown) provided in the second support portion 72 is screwed into the second Y-axis ball screw 70. ing. The second support portion 72 is moved in the Y-axis direction by being driven by the second Y-axis pulse motor 71 and rotating the second ball screw 70. The position of the second support portion 72 in the Y-axis direction is measured by the linear scale 64 and is used for precise control of the position in the Y-axis direction.

  On the side surface side of the first support portion 65, the first cutting means 3 can move up and down in the cutting direction (Z-axis direction) by the first cutting feed means 8. The first infeed means 8 includes a first Z-axis ball screw 80 disposed in the Z-axis direction, a first Z-axis guide rail 81 disposed in parallel to the first Z-axis ball screw 80, A first Z-axis pulse motor 82 connected to one end of the Z-axis ball screw 80 and a first Z-axis guide rail 81 are slidable, and an internal nut is screwed into the first Z-axis ball screw 80. The first elevating part 83 is driven by the first Z-axis pulse motor 82 and the first elevating part 83 is moved to the first Z-axis as the first Z-axis ball screw 80 rotates. Guided by the guide rail 81, the first cutting means 3 is also lifted and lowered along with this.

  On the side surface side of the second support portion 72, the second cutting means 4 can move up and down in the cutting direction (Z-axis direction) by the second cutting feed means 9. The second infeed means 9 includes a second Z-axis ball screw 90 disposed in the Z-axis direction, a second Z-axis guide rail 91 disposed in parallel to the second Z-axis ball screw 90, A second Z-axis pulse motor 92 connected to one end of the second Z-axis ball screw 90 and a second Z-axis guide rail 91 are slidable, and an internal nut is connected to the second Z-axis ball screw 90. The second elevating part 93 is screwed and driven by the second Z-axis pulse motor 92, and as the second Z-axis ball screw 91 rotates, the second elevating part 93 is second. The second cutting means 4 is also lifted and lowered by being guided by the Z-axis guide rail 91.

  The first cutting means 3 and the second cutting means 4 fixed to the first elevating part 83 and the second elevating part 93 are rotated by the housing 30 (40) as shown in FIGS. A cutting blade 32 (42) is attached to the tip of the spindle 31 (41) that is supported so that the nut 33 (43) is screwed into the male thread 31a (41a) formed on the spindle 31 (41). Thus, the cutting blade 32 (42) is fixed. The cutting blade 32 constituting the first cutting means 3 and the cutting blade 42 constituting the second cutting means 4 are the same kind of blades.

  The cutting blade 32 (42) is covered from above by a blade cover 34 (44), and a cutting water nozzle 35 (45) is disposed below the blade cover 34 (44). In addition, a cutting water inlet 36 (46) is disposed above the blade cover 34 (44), and a first blade monitoring unit 37 and a second blade monitoring unit 47 for monitoring the state of the cutting blade are provided. It is attached by screws 38 (48).

  As shown in FIG. 4, the first blade monitoring unit 37 and the second blade monitoring unit 47 include a light emitting unit 370 (470) and a light receiving unit 371 (471) having a common optical axis in the Y-axis direction. In the state where the cutting blade 32 (42) is not defective, light is blocked by the cutting blade 320 (420) of the cutting blade 32 (42), and light is received when the cutting blade 320 (420) is worn or damaged. In the part 371 (471), the light emitted from the light emitting part 370 (470) is received, so that it is possible to detect that a malfunction has occurred in the cutting blade 32 (42).

  Returning to FIG. 1, the first alignment unit 39 including the first imaging unit 390 is fixed to the side portion of the first cutting unit 3. Similarly, a second alignment unit 49 including a second imaging unit 490 is fixed to the side of the second cutting unit 4. The first alignment means 39 and the second alignment means 49 serve to detect the position to be cut by imaging the wafer to be cut. The cutting blades 32 and 42 are driven to rotate by motors 32a and 42a, respectively.

  The first Z-axis pulse motor 82 and the motor 32 a are controlled by the first control means 10. The first control means 10 can receive information from the first blade monitoring means 37 (see FIG. 4) provided in the first cutting means 3 and perform processing according to the information. Similarly, the second Z-axis pulse motor 92 and the motor 42 a are controlled by the second control means 11. The 2nd control means 11 can receive the information from the 2nd blade monitoring means 47 (refer FIG. 4) with which the 2nd cutting means 4 was equipped, and can perform the process according to the information. Between the first control means 10 and the second control means 11, a cutting information exchanging means 12 for exchanging cutting information between them is provided.

  For example, when the wafer W is diced and divided into individual devices, the wafer W held on the frame F via the tape T is placed on the chuck table 2 and sucked and held. Then, the first imaging unit 390 and the second imaging unit 490 move in the Y-axis direction and are positioned above the movement path of the chuck table 2, and the chuck table 2 is moved in the + X direction by the cutting feed means 30. Thus, the wafer W is positioned directly below the first imaging unit 390 and the second imaging unit 490.

  Then, the surface of the wafer W is imaged by the first imaging unit 390 and the second imaging unit 490, and the streets that are the planned separation lines to be cut are detected by the first alignment unit 39 and the second alignment unit 49, respectively. Then, the street detected by the first alignment means 39 and the cutting blade 32 are aligned in the Y-axis direction, and the street detected by the second alignment means 49 and the cutting blade 42 are in the Y-axis direction. Are aligned.

  In this state, the chuck table 2 further moves in the + X direction, and the first cutting means 3 and the second cutting means 4 descend while the cutting blade 32 and the cutting blade 42 rotate at a high speed, as shown in FIG. In addition, each street is cut by cutting into each street S. Further, while moving the chuck table 2 in the X-axis direction, the first cutting means 3 is indexed and fed in the + Y direction by the street interval, and the second cutting means 4 is indexed and fed in the −Y direction by the street interval. By doing, the street is cut sequentially. Further, when the wafer W is rotated 90 degrees together with the chuck table 2 and then the same cutting is performed, all the streets are cut and divided into individual devices. The order of cutting is as follows: the first cutting means 3 and the second cutting means 4 are positioned on the outermost street of the wafer W and gradually brought closer to the inside; the first cutting means 3 and the first cutting means The procedure in which the second cutting means 4 is positioned in the center region of the wafer W and gradually moved outward, and the first cutting means 3 and the second cutting means 4 are indexed and fed in the same direction while maintaining a certain distance. Here, a procedure for gradually bringing the first cutting means 3 and the second cutting means 4 closer to each other will be described.

  In the process of cutting as described above, the first cutting means 3 or the second cutting means 4 may have some trouble that makes it impossible to continue cutting. For example, when the cutting blade 32 constituting the first cutting means 3 is worn or damaged, the first blade monitoring means 37 detects this (step S1). Then, the first control means 10 is notified of this, and the first control means 10 raises the first cutting means 10 to retract from the cutting position and stops the motor 32a. When the first control means 10 stops the cutting by the first cutting means 3, the cutting information, for example, the initial position in the Y-axis direction of the cutting blade 32 at the start of cutting, the position in the Y-axis direction at the time of cutting stop, The value of the street interval or the like is transferred to the cutting information exchanging means 12.

  On the other hand, the 2nd cutting means 4 in which the malfunction has not arisen continues cutting as it is. Further, the cutting information in the first control unit 11 is transferred from the cutting information exchange unit 12 to the second control unit 11. In the second control means 11, the street that should have been cut by the first cutting means 3 can be cut by the second cutting means 4 by considering the cutting information.

As an example, as shown in FIG. 6, for a wafer W having ₁₉ vertical streets SV _{01 to} SV ₁₉ and 17 horizontal streets SH _{01 to} SH ₁₇ , The case where the first cutting means 3 cuts the streets SV _{01 to} SV ₁₀ and the second cutting means 4 cuts the streets SV _{11 to} SV ₁₉ will be described.

First, the street SV ₀₁ is cut using the first cutting means 3, and the street SV ₁₉ is cut using the second cutting means 4, and the first cutting means 3, the second cutting means 4, Gradually approach.

In FIG. 7, the streets that have been cut are indicated by bold lines. In the illustrated example, the streets SV _{01 to} SV ₀₅ are cut by the first cutting means 3 to form cutting grooves, and the second cutting means 4 Streets SV _{19 to} SV ₁₅ are cut to form cutting grooves. At this time, for example, the processing when the second blade monitoring means 47 (see FIG. 4) detects that the cutting blade 42 constituting the second cutting means 4 is damaged is described with reference to FIG. This will be described below. In FIG. 7, the configuration of the first cutting means 3 and the second cutting means 4 is shown in a simplified manner.

  First, the second blade monitoring unit 47 notifies the second control unit 11 that a defect has occurred in the cutting blade 42. Then, the second control unit 11 retracts the second cutting unit 4 from the wafer W and positions the second cutting unit 4 at a position where cutting is not performed, and the cutting information at that time, for example, the position of the cutting blade 42 in the Y-axis direction, street Information on the interval and the like is transferred to the cutting information exchange unit 12. Then, the cutting information exchange unit 12 transfers the cutting information to the first control unit 10.

The first control means 10 recognizes an uncut street that should have been cut by the second cutting means 4 from information on the position of the cutting blade 42 in the Y-axis direction and the street interval included in the cutting information. be able to. Specifically, the first control means 10 shifts the position displaced in the −Y direction by the street interval from the current position of the second cutting blade 42, that is, the street on the −Y direction side from the street SV ₁₄ . It is judged that one cutting means 3 should cut. Then, the first cutting means 3 sequentially cuts the streets while continuing the indexing feed without stopping the cutting, and for the streets in the vertical direction, the street SV ₁₀ that should originally be cut is cut. After being broken, cutting is performed to street SV ₁₄ while continuing the indexing feed. In this way, the street in the vertical direction is cut without reducing the productivity by the first cutting means 3 cutting the street that the second cutting means 4 originally should cut.

  In addition, since the second cutting means 4 in which the defect has occurred is retracted to a position where no cutting is performed, the second cutting means 4 is being cut while the first cutting means 3 is being cut. The second cutting blade 42 constituting the blade can be replaced, adjusted, repaired, etc., so that the problem can be resolved at an early stage.

On the other hand, as for the street in the horizontal direction, if the trouble of the cutting blade 42 constituting the second cutting means 4 is eliminated, the first street cutting means 3 and the second cutting means 4 share the cutting. Alternatively, if the problem of the cutting blade 42 has not been solved, all the streets SH _{01 to} SH ₁₇ in the lateral direction may be cut only by the first cutting means 3.

  In the above example, the first blade monitoring unit 37 and the second blade monitoring unit 47 detect wear and damage of the cutting blades 32 and 42. It is also possible to take an image with 390 and 490 and determine the presence or absence of a defect based on the shape in the alignment means 39 and 49. For example, when the width of the cutting groove is wider than the desired width or chipping occurs on the side surface of the device, it is determined that any of the cutting blades 32 and 42 is clogged, and the position of the cutting groove Can be determined that the mounting positions of the cutting blades 32 and 42 with respect to the spindles 31 and 41 are shifted. If there are problems such as clogging of the cutting blades 32 and 42 and displacement of the mounting positions of the cutting blades 32 and 42, the alignment means 39 and 49 are transferred to the first control means 10 and the second control means 11, respectively. The effect can be notified and cutting can be stopped.

  In the above example, the cutting apparatus having the configuration in which the two cutting blades are arranged to face each other has been described. However, the cutting apparatus having the configuration in which the two spindles are arranged in parallel and the two cutting blades are arranged in parallel. The present invention can also be applied to. Further, the present invention can be applied not only when there are two cutting means provided in the cutting apparatus but also when there are three or more cutting means.

It is a perspective view which shows an example of a cutting device. It is a perspective view which shows the cutting means which comprises the cutting device. It is a disassembled perspective view of the cutting means. It is a side view which shows a blade monitoring means and a cutting device. It is a perspective view which shows the state which cuts a wafer. It is a top view which shows the wafer united with the flame | frame via the tape. It is a top view which shows the state which cuts the street of the wafer with the 1st cutting means and the 2nd cutting means. It is a top view which shows the state which cuts the street of the wafer with a 1st cutting means.

Explanation of symbols

1: Cutting device 2: Chuck table 3: First cutting means 30: Housing 31: Spindle 32: Cutting blade 320: Cutting blade 33: Nut 34: Blade cover 35: Cutting water nozzle 36: Cutting water inlet 37: First 370: Light emitting unit 371: Light receiving unit 38: Screw 39: First alignment unit 390: First imaging unit 4: Second cutting unit 40: Housing 41: Spindle 42: Cutting blade 420: Cutting blade 43: Nut 44: Blade cover 45: Cutting water nozzle 46: Cutting water inlet 47: Second blade monitoring means 470: Light emitting part 471: Light receiving part 48: Screw 49: Second alignment means 490: Second imaging part 5: Cutting feed means 50: X-axis guide rail 51: X-axis moving base 52: X-axis ball screw 53: X Pulse motor 54: Support base 6: First index feeding means 60: Wall portion 61: Y-axis guide rail 62: First Y-axis ball screw 63: First Y-axis pulse motor 64: Linear scale 65: First Support part 7: Second index feed means 70: Second Y-axis ball screw 71: Second Y-axis pulse motor 72: Second support part 8: First cut feed means 80: First Z-axis Ball screw 81: First Z-axis guide rail 82: First pulse motor 83: First elevating unit 9: Second cutting feed means 90: Second Z-axis ball screw 91: Second Z-axis guide rail 92 : Second pulse motor 93: second elevator 10: first control means 11: second control means 12: cutting information exchanging means W: wafer SV _xx : vertical street SH _xx : horizontal street : Device T: tape F: frame

Claims (4)

A chuck table for holding a workpiece, a first cutting means having at least a first cutting blade for cutting the workpiece held on the chuck table, and a second having a second cutting blade And cutting the wafer by causing the first cutting means and the second cutting means to act on a predetermined separation line formed on the wafer held by the chuck table. A wafer cutting method comprising:
When a failure occurs in either the first cutting means or the second cutting means, the cutting means in which the failure has occurred is retracted from the wafer, and the wafer is removed by another cutting means in which no failure has occurred. Wafer cutting method to continue cutting. A chuck table for holding the workpiece;
A first cutting means comprising a first cutting blade for cutting a workpiece held on the chuck table;
A second cutting means comprising a second cutting blade for cutting a workpiece held on the chuck table;
First control means for controlling the first cutting means;
Second control means for controlling the second cutting means;
First defect detecting means for detecting a defect of the first cutting means and notifying the first control means of the defect information;
At least a second defect detection means for detecting a defect in the second cutting means and notifying the second control means of the defect information;
When a defect detection unit detects that a defect has occurred in any of the cutting means, and the defect detection unit notifies the corresponding control unit of the defect information, the control unit has a defect. A cutting device that retracts the cutting means and continues cutting by the cutting means to which the other control means corresponds. Cutting information exchange means for exchanging cutting information between at least the first control means and the second control means,
When a failure occurs in any of the cutting means, the cutting information of the cutting means is transmitted from the control means that controls the cutting means in which the failure has occurred to the other control means via the cutting information exchange means. 3. The cutting apparatus according to claim 2, wherein the other control means performs the cutting to be performed by the cutting means in which the defect has occurred in consideration of the received cutting information. The cutting apparatus according to claim 2 or 3, wherein the failure detection means is blade monitoring means for monitoring wear or damage of the cutting blade.

Images