JP2010109228A - Apparatus and method for removing chamfering portion from wafer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid deterioration in the functions and quality of each device, by preventing cutting chips from attaching to and contaminating devices on a surface of a wafer, when removing a chamfering portion from the wafer by cutting. <P>SOLUTION: The wafer W has a front surface Wa having a device region W1, in which multiple devices are formed, and a peripheral excess region W2 surrounding the device region W1; and an arc-shaped chamfering portion W3, which is formed at the edge of the peripheral excess area W2 and extends from the front surface Wa to the rear surface Wb. An apparatus for removing the chamfering portion W3 from the wafer W by cutting is provided with an opposing member 84, that is opposed to the device region W1 and a clearance 9 that is formed between the device region W1 and the opposing member 84. By removing the chamfering portion W3, cutting while making the wafer W rotate with a water layer 90 formed in the clearance 9, cutting of chips from attaching to the devices is prevented. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an apparatus and a method for removing a chamfered portion of a wafer having a chamfered portion on the periphery by cutting.

  A wafer formed by dividing a device such as an IC or LSI on a surface by dividing lines is divided into individual device devices by a dicing apparatus and used for various electronic devices. Before the wafer is divided into individual devices, the back surface is ground to a predetermined thickness.

  However, arc edges are chamfered around the periphery of the wafer to prevent chipping and cracking during the manufacturing process. Therefore, if the wafer is thinned by grinding the back surface, There is a problem that the portion remains and the periphery of the wafer is sharpened like a knife, which makes handling difficult and easily causes chipping.

  Therefore, a technique has been proposed in which the chamfered portion is removed by cutting before grinding the back surface of the wafer so that the peripheral edge is not sharpened even if the back surface is ground (see, for example, Patent Document 1).

JP 2000-173961 A

  However, when the chamfered portion is removed by cutting, there is a problem that the cutting waste generated by the cutting drifts together with the cutting water on the surface of the wafer and adheres to the surface of the device to deteriorate the quality of the device. In particular, in the case of a device such as a CMOS image sensor in which the adhesion of foreign matter greatly affects the function and quality, it becomes a problem that cannot be overlooked.

  Therefore, the problem to be solved by the present invention is to prevent the chip from being attached to the wafer surface and contaminating the device when removing the chamfered portion at the periphery of the wafer by cutting. Is to prevent it from falling.

  A first invention is a wafer in which a device region in which a plurality of devices are formed and an outer peripheral surplus region surrounding the device region are formed on the surface, and an arc-shaped chamfered portion is formed on the periphery of the outer peripheral surplus region from the surface to the back surface The present invention relates to a wafer chamfered part removing apparatus that removes a chamfered part of a wafer by cutting, and a cutting table that holds a wafer and rotates a chuck table that is rotatable and a peripheral cutting area of the wafer that is held on the chuck table by a rotatable cutting blade. And a water layer forming means for forming a water layer in a gap formed between the device region of the wafer held on the chuck table and the facing member. Yes.

  A second invention is a wafer in which a device region in which a plurality of devices are formed and an outer peripheral surplus region surrounding the device region are formed on the surface, and an arc-shaped chamfered portion is formed on the periphery of the outer peripheral surplus region from the surface to the back surface The chamfered portion of the wafer is removed by cutting, and a facing member is made to face the device region of the wafer to form a gap between the device region and the facing member, and a water layer is formed in the gap. In the formed state, the wafer is rotated and the chamfered portion is removed by cutting the inner peripheral side of the chamfered portion in the outer peripheral surplus region.

  In the present invention, since a gap is formed between the device region of the wafer and the facing member, and the chamfered portion can be removed by cutting in a state in which a water layer is formed in the gap, the cutting dust adheres to the device. There is no. Therefore, it is possible to prevent the function and quality of the device from being deteriorated.

  A wafer chamfer removing apparatus 1 shown in FIG. 1 includes a chuck table 2 that holds a wafer and a cutting means 3 that cuts the wafer held on the chuck table 2. The chuck table 2 can be rotated by being driven by the rotation driving means 4 and can be moved in the X-axis direction by being driven by the X-axis direction feeding means 5. On the other hand, the cutting means 3 is driven by the Y-axis direction feeding means 6 and is movable in the Y-axis direction, and is also driven by the Z-axis direction feeding means 7 and is movable in the Z-axis direction.

  The chuck table 2 includes a suction unit 20 having a slightly smaller diameter than the wafer to be cut. The chuck table 2 is connected to a motor inside the rotation driving means 4 disposed below the chuck table 2 so as to be rotatable.

  The cutting means 3 is configured such that a spindle 30 having an axis in the Y-axis direction is rotatably supported by a housing 31, and a cutting blade 32 is attached to the tip of the spindle 30. An alignment unit 33 that captures and detects an area to be cut by the imaging unit 330 is fixed.

  The X-axis direction feeding means 5 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 connected to one end of the ball screw 50, and not shown. An internal nut is screwed into the ball screw 50 and a lower portion is formed of a slide portion 53 that is in sliding contact with the guide rail 51. The slide portion 53 is moved to the guide rail 51 as the ball screw 50 is rotated by being driven by the motor 52. The rotary drive means 4 fixed to the slide part 53 and the chuck table 2 connected to the rotary drive means 4 are also moved in the X-axis direction.

  The Y-axis direction feeding means 6 includes a ball screw 60 having an axis in the Y-axis direction, a pair of guide rails 61 arranged in parallel to the ball screw 60, a pulse motor 62 connected to one end of the ball screw 60, and The inner nut is screwed into the ball screw 60 and the lower part is composed of a slide part 63 which is in sliding contact with the guide rail 61. The slide part 63 is guided by the pulse motor 62 as the ball screw 60 rotates. It slides on the rail 61 in the Y-axis direction, and the cutting means 3 is configured to move in the Y-axis direction accordingly.

  The Z-axis direction feeding means 7 includes a ball screw 70 having an axis in the Z-axis direction, a pair of guide rails 71 arranged in parallel to the ball screw 70, a pulse motor 72 connected to one end of the ball screw 70, The inner nut is screwed into the ball screw 70 and the side portion is formed of a support portion 73 that is in sliding contact with the guide rail 71 and supports the cutting means 3, and is driven by the pulse motor 72 to rotate the ball screw 70. Accordingly, the support portion 73 is guided by the guide rail 71 and moves up and down in the Z-axis direction, and the cutting means 3 is also moved up and down in the Z-axis direction.

  The water layer forming means 8 is connected to the slide portion 53 constituting the X-axis direction feeding means 5. The water layer forming means 8 includes a base portion 80 connected to the slide portion 53, a shaft portion 81 that can be moved up and down with respect to the base portion 80, and a shaft portion 81 that extends horizontally from the upper end of the shaft portion 81 and moves up and down together with the shaft portion 81. Arm part 82, hanging part 83 suspended from the tip of arm part 82, facing member 84 positioned at the lower end of hanging part 83, and water source 85 for storing water flowing out from facing member 84. . In the illustrated example, the water stored in the water source 85 flows into the arm portion 82 via the valve 86. The facing member 84 can be selectively positioned at a position facing the wafer held by the chuck table 2 and a position not facing the wafer held by the chuck table 2 by the rotation of the shaft portion 81.

  In the example shown in FIG. 2, the water layer forming means 8 has a flow passage 87 formed through the arm portion 82, the hanging portion 83, and the facing member 84, and the water that has flowed through the flow passage 87 is facing the facing member 84. It is the structure which flows out downward from the outflow port 840 of the lower surface of the. The water layer forming means 8 is fixed to the slide portion 53 in the example of FIG. 1, but the arrangement position is limited to the illustrated example as long as the facing member 84 is configured to face the chuck table 2. Not.

  As shown in FIG. 3, the surface Wa of the wafer W to be cut is composed of a device region W1 partitioned by streets S and formed with a plurality of devices D, and an outer peripheral surplus region W2 surrounding the device region W1. The A chamfered portion W3 that is chamfered in an arc shape is formed from the front surface Wa to the back surface Wb at the periphery of the outer peripheral surplus region W2.

  As shown in FIG. 1, the wafer W to be cut shown in FIG. 3 is sucked by the chuck table 2 on the back surface Wb side and is held with the front surface Wa exposed. At this time, the rotation center of the chuck table 2 and the center of the wafer W are made to coincide.

  Then, in a state where the facing member 84 constituting the water layer forming means 8 is retracted from above the moving path of the chuck table 2, the X-axis direction feeding means 5 moves the wafer W directly below the image pickup means 330, and the wafer W The surface Wa is imaged, the position to be cut is detected by the alignment means 33, and the detected position and the cutting blade 32 are aligned in the Y-axis direction. This position to be cut is on the inner peripheral side of the chamfered portion W3 in the outer peripheral surplus region W2.

  Next, the X-axis direction feeding means 5 moves the chuck table 2 in the + X direction, and positions the wafer W to be cut immediately below the cutting blade 32. Then, the facing member 84 that has been retracted is moved directly above the wafer W and lowered to form a slight gap 9 between the device region W1 of the wafer W and the bottom surface of the facing member 84, and FIG. As shown in FIG. 4, the water supplied from the water source 85 flows out from the outlet 840 of the facing member 84 to form the water layer 90 in the gap 9.

  While the chuck table 2 is rotated with the water layer 90 formed, the cutting means 3 is lowered while the cutting blade 32 is rotated at a high speed, and the cutting blade 32 is applied to the detected cutting position to perform cutting. Is turned off to remove the chamfered portion W3. Then, the peripheral edge of the wafer W becomes a vertical surface.

  During the cutting, the device region W1 shown in FIG. 3 is always covered with the water layer 90, and the water flows out from the central portion of the wafer W toward the outer peripheral side. Never invade. Therefore, cutting waste does not adhere to each device D constituting the device region W1, and it is possible to prevent the quality and function of the device from being deteriorated.

  The facing member 84 is formed such that its radius is shorter than the length from the center of the wafer W to the cutting position, and the cutting blade 32 does not contact the facing member 84 during cutting. If the facing member 84 has a larger diameter than the device region W1, the water layer 90 can completely cover the device region W1, but the radius of the facing member 84 is slightly shorter than the radius of the device region W1. The degree is acceptable. For example, the radius of the facing member 84 is desirably about 2 to 3 mm shorter than the length from the center of the wafer W to the cutting position.

  As shown in FIG. 5, a clearance groove 21 is formed in the chuck table 2, and during cutting, the lower end of the cutting blade 21 is accommodated in the clearance groove 21, and the cutting blade 32 penetrates the front and back of the wafer W. At this time, since the water flowing out from the water layer 90 toward the outer peripheral side of the wafer W is supplied to the contact portion between the cutting blade 32 and the wafer W, the water flowing out from the water layer 90 to the side is also used as the cutting water. Function. Therefore, a dedicated nozzle for discharging cutting water is not necessary.

  As shown in FIG. 6, when the thickness of the cutting blade 32a exceeds the width of the chamfered portion W3, the chamfered portion W3 can be cut by the cutting blade 32a.

It is a perspective view which shows an example of a wafer chamfer part removal apparatus. It is sectional drawing which shows a part of water layer formation means schematically. It is a perspective view which shows an example of a wafer. It is sectional drawing which shows schematically the state which removes the chamfering part of a wafer. It is sectional drawing which expands and shows the state which removes the chamfer part of a wafer. It is sectional drawing which expands and shows another example of the state which removes the chamfer part of a wafer.

Explanation of symbols

1: Wafer chamfer removal device 2: Chuck table 20: Suction part 21: Escape groove 3: Cutting means 30: Spindle 31: Housing 32, 32a: Cutting blade 33: Alignment means 330: Imaging means 4: Rotation drive means 5: X-axis direction feeding means 50: Ball screw 51: Guide rail 52: Motor 53: Slide part 6: Y-axis direction feeding means 60: Ball screw 61: Guide rail 62: Motor 63: Slide part 7: Z-axis direction feeding means 70: Ball screw 71: Guide rail 72: Motor 73: Support part 8: Water layer forming means 80: Base part 81: Shaft part 82: Arm part 83: Hanging part 84: Facing member 85: Water source 86: Valve 87: Channel 9: Clearance 90 : Water layer W: Wafer Wa: Front surface Wb: Back surface W1: Device region W2: Peripheral portion W3: Chamfered portion D: Debye S: Street

Claims (2)

The chamfered portion of the wafer in which a device region in which a plurality of devices are formed and an outer peripheral surplus region surrounding the device region are formed on the surface, and an arc-shaped chamfered portion is formed from the front surface to the rear surface at the periphery of the outer peripheral surplus region Is a wafer chamfered portion removing device that removes by cutting,
A chuck table capable of holding and rotating a wafer;
A cutting means that includes a rotatable cutting blade and that cuts the outer peripheral surplus area of the wafer held by the chuck table;
A facing member capable of facing at least the device region, and a water layer forming means for forming a water layer in a gap formed between the device region of the wafer held on the chuck table and the facing member. Wafer chamfer removal device. The chamfered portion of the wafer in which a device region in which a plurality of devices are formed and an outer peripheral surplus region surrounding the device region are formed on the surface, and an arc-shaped chamfered portion is formed from the front surface to the rear surface at the periphery of the outer peripheral surplus region Is a method for removing a chamfered portion of a wafer that is removed by cutting,
With the facing member facing the device region of the wafer, a gap is formed between the device region and the facing member, and the chamfer is formed by cutting while rotating the wafer in a state where a water layer is formed in the gap. For removing the wafer chamfered portion.

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