JP2013058671A - Breaking device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a breaking device that allows alignment from a reflective film surface side of a wafer to the wafer on which a reflective film is formed.SOLUTION: In a breaking device 1 that adds flexural stress to a divisional schedule line L of a wafer W and breaks the wafer W by contacting a blade 43, imaging means 30 is arranged in a space 16 formed between a pair of supporting rails 21 vertically arranged in parallel near the center of the top surface of a device base 10. The imaging means 30 includes an IR camera 31 imaging the divisional schedule line L and a calculating unit 33 calculating the amount of deviation between the X direction and the rotative direction on the basis of an image by the IR camera 31. Since the IR camera 31 can image the divisional schedule line L from a reflective film 4 side of the wafer W on which the reflective film 4 is formed, the alignment for aligning the position of the divisional schedule line L with the position of the blade 43 can be performed, thereby easily dividing the wafer W and improving the yield of semiconductor chips.

Description

  The present invention relates to a braking apparatus for cutting a workpiece into individual devices.

  Devices such as ICs, LSIs, and LEDs are defined by division lines and formed on the surface of an LED wafer, a sapphire wafer, or the like. Then, individual chips are manufactured by cutting the wafer with a blade or the like along the division lines formed on the surface of the wafer.

  As a device that divides LED wafers, sapphire wafers, etc., for example, a grid-like scribe line is formed by a diamond scriber along the planned division line on the surface of the wafer, or laser light is condensed inside the wafer and modified. There is a braking apparatus for manufacturing individual chips by cutting a wafer while applying a bending stress with a blade after forming a layer.

  Usually, in such a braking apparatus, the apparatus base, a pair of support bases for supporting a wafer disposed with a gap in the center of the upper surface of the apparatus base, and the support base are disposed above the support base and can move up and down. The lower side (back side) of the wafer placed on the support base, in order to align the blade and the planned alignment line with the blade. The image is taken by an alignment camera (see, for example, Patent Document 1).

JP 2009-148982 A

  However, if an opaque body exists in the direction in which the lens of the alignment camera faces, a normal alignment camera cannot capture the image through the opaque body, and cannot detect the planned division lines formed on the wafer. Unable to align with blade position.

  As an opaque body, for example, there is a reflective film formed on the back surface of a wafer to improve luminance. The reflective film is formed for the purpose of reflecting the light toward the back side and improving the extraction amount of the light emitted from the entire LED. There is a problem in that the modified layer formed inside cannot be imaged, and the position of the division line formed on the wafer and the position of the blade cannot be aligned.

  On the other hand, by inverting the wafer in the reverse direction and mounting the front surface side of the wafer that can be aligned on the support base, the alignment camera can align the position of the division line and the position of the blade.

  However, in this case, it is necessary to divide the wafer in the reverse direction, that is, from the back side where the reflective film is formed. Chips and cracks that cannot be increased may increase.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to enable alignment from the opaque body side with respect to a workpiece on which an opaque body is formed.

  The braking device according to the present invention is a braking device that cuts the workpiece by applying a bending stress by bringing a blade into contact with a division line of the workpiece supported on the ring frame via an adhesive tape. A pair of support rails standing in parallel with a predetermined gap near the center of the upper surface of the apparatus base, a support base for supporting a workpiece disposed at one end of the support rail, and disposed above the gap And an imaging means disposed in the gap, and an X base operable in the X direction is disposed on the upper surface of the apparatus base, and the support base is centrally disposed on the X base. A holding base that holds a ring frame that is rotatable about the center of the through hole is disposed on the upper surface of the X base, and the imaging means captures an image of the planned division line. And the IR A calculation unit that calculates a deviation amount between the X direction and the rotation direction from the photographed image of the camera, and operates the X base and the holding table from the numerical values of the calculation unit to support the division lines to be processed. The workpiece is moved to the inside of the gap of the table and the blade is lowered to cut the workpiece.

  In the present invention, an IR camera that captures a line to be divided in a gap formed between a pair of support rails in the braking device, and an arithmetic unit that calculates the amount of deviation in the X direction and the rotational direction from the captured image of the IR camera. By mounting the imaging means provided, it is possible to image the wafer division planned line from the reflective film surface side with respect to the wafer on which the reflective film is formed, and the alignment for aligning the position of the planned division line and the blade position is achieved. It becomes possible. Thus, the wafer can be easily braked with a bending stress necessary for normal division. And it can prevent that the crack which affects the process of the chip | tip which cannot be divided | segmented, or a wafer increases, and the yield of a semiconductor chip improves.

(A) is a perspective view which shows the wafer with which the ring frame was mounted | worn through the adhesive tape, and the protective film of a wafer, (b) is sectional drawing which shows a wafer, a reflecting film, and a protective film. It is a perspective view which shows an example of a braking device. It is sectional drawing which shows the positional relationship of a wafer and each mechanism contained in a braking device. It is explanatory drawing which shows the imaging process with respect to a division | segmentation schedule line. It is an expanded sectional view which shows the braking process with respect to a division planned line.

  A wafer W shown in FIG. 1 is an example of a workpiece to be cut by the braking apparatus 1 shown in FIG. As shown in FIG. 1A, on the surface Wa of the wafer W, for example, a plurality of devices D are formed by being partitioned by a grid-like division planned line L. The division line L is subjected to, for example, a process of forming a modified layer by condensing a pulse laser inside the wafer W. Further, as shown in FIG. 1B, the back surface Wb is coated with a reflective film 4 for improving luminance.

  As shown in FIG. 1A, the wafer W is attached to the adhesive tape T with the back surface Wb side on which the division line L is formed facing upward, and the ring frame 2 through the adhesive tape T. And is supported by the ring frame 2 via an adhesive tape T. The protective film 3 is a transparent body and is made of a resinous adhesive material. The protective film 3 is adhered to the back surface Wb side in order to protect the wafer W.

  The braking device 1 shown in FIG. 2 is an example of a braking device that applies a bending stress to the wafer W on which the planned division line L is formed and cuts the wafer W. A pair of guide rails 11 extending in the X-axis direction, an X base 12 movable in the X-axis direction, a holding table 13 that holds the ring frame 2, a support table 20 that supports the wafer W, and a wafer W are arranged above the wafer W. The applied stress applying means 40 and the control means 60 for controlling the operation of the braking device 1 are provided.

  A moving part 12 a is attached to the lower part of the X base 12. The guide rail 11 is in sliding contact with the moving portion 12a, and the drive portion 14 is operated, whereby the moving portion 12a is guided by the guide rail 11 and moves in the X-axis direction. It is configured to move in the direction.

  As shown in FIG. 3, the X base 12 has a through hole 120, and the holding base 13 can be inserted into the through hole 120 and accommodated.

  The holding table 13 is formed in a disk shape and has a through hole 130 in the center. The holding stand 13 can hold the ring frame 2 in a detachable manner. The holding table 13 can be rotated by the gear 15 around the through hole 120.

  In the center of the apparatus base 10, a pair of support rails 21 that are arranged in parallel with a predetermined gap 16 are erected. A support base 20 is disposed at one end of the support rail 21. The support table 20 is inserted into the through hole 130 of the holding table 13 and supports the wafer W via the protective film 3.

  As shown in FIG. 3, the imaging means 30 is disposed in the gap 16 formed on the upper surface of the apparatus base 10 and between the pair of support rails 21. As shown in FIG. 4, the imaging means 30 is based on an IR (Infrared Rays) camera 31 that captures the planned division line L, a lens 32 provided at one end of the IR camera 31, and an image captured by the IR camera 31 in the X direction. And a calculation unit 33 for calculating the amount of deviation in the rotation direction.

  Even when an opaque body exists in the direction in which the IR camera 31ha and the lens 32 face, the inside of the wafer W can be imaged through the opaque body. As shown in FIG. 3, the IR camera 31 is disposed in the gap 16 positioned below the wafer W supported by the support base 20 with the lens 32 facing upward, and the wafer W on which the reflective film 4 is formed. The direction of the blade 43 disposed above the gap 16 can be imaged from the back surface Wb side.

  The calculation unit 33 illustrated in FIG. 4 is configured to calculate the difference between the position of the distal end portion 43a of the blade 43 and the position of the planned division line L based on the data acquired from the captured image of the IR camera 31. Yes.

  2 includes a moving base 41 for processing and feeding in the Z-axis direction, a guide rail 42 extending in the Z-axis direction, a blade 43 for cutting the wafer W into individual devices D, and an unillustrated And a drive motor 44 connected to one end of a ball screw extending in the Z-axis direction. The blade 43 is mounted on the moving base 42. The blade 43 is formed with a tip portion 43a, and a bending stress is applied to the wafer W to be cut through the tip portion 43a.

  A pair of guide rails 42 are in sliding contact with one surface of the movable base 41, and a nut structure (not shown) is formed in the center portion, and a ball screw is screwed into the nut structure. Then, when the ball screw rotated by the drive motor 44 is rotated, the moving base 41 is guided by the guide rail 42 and moved in the Z-axis direction, and the blade 43 can be moved up and down in the Z-axis direction. it can.

  The vibration detector 50 shown in FIG. 3 is disposed on the upper surface of the apparatus base 10 and in contact with the support rail 21. The vibration detector 50 detects the vibration of the support base 20 that occurs when bending stress is applied to the wafer W by the blade 43 via the support rail 21. When a vibration amount equal to or greater than the threshold value stored in advance in the control means 60 is detected, a cutting achievement signal is transmitted to the control means 60 assuming that the wafer W has been cut.

  The control means 60 shown in FIG. 2 is connected to each operation mechanism such as the X base 12, the holding base 13, the imaging means 30, the stress applying means 40, and the vibration detector 50. Further, the control means 60 incorporates a memory and a CPU for storing various data necessary for controlling each operation mechanism such as the X base 12, the holding base 13, the imaging means 30, the stress applying means 40, the vibration detector 50, and the like. ing. And the control means 60 controls operation | movement of the braking device 1 collectively based on the data sent from each operation | movement mechanism.

Hereinafter, an operation example of the braking device 1 shown in FIG. 2 will be described.
As shown in FIG. 3, when the back surface Wb side of the wafer W is supported on the top surface of the support 20 via the protective film 3, the back surface Wb side of the wafer W on which the reflective film 4 is formed and the lens 32 of the IR camera 31. Are positioned so as to face each other. The IR camera 31 starts imaging processing of the planned division line L by the IR camera 31 in order to perform alignment (alignment) between the planned division line L and the tip 43a of the blade 43.

  When the IR camera 31 irradiates infrared rays in the direction of the blade 43 provided above the wafer W, the infrared rays pass through the transparent protective film 3 attached to the back surface Wb side of the wafer W, and further, the reflective film 4 is also transmitted. Then, the image including the planned division line L of the wafer W is enlarged and captured by the lens 32, and the electric power corresponding to the captured image obtained by imaging the image including the planned division line L is calculated in order to calculate data necessary for alignment. The signal is transmitted to the calculation unit 33.

  4 compares the preset position of the tip 43a of the blade 43 and the position of the imaged planned division line L based on data acquired from the image captured by the IR camera 31. Then, the calculation unit 33 calculates the amount of deviation between the position of the tip part 43a of the blade 43 and the position of the planned division line L, and then the amount of movement necessary for aligning the position of the tip part 43a and the planned division line L, That is, the amount of movement of the X base 12 in the X-axis direction and the amount of rotational movement of the holding base 13 around the Z-axis are converted into numerical values and calculated.

  Thus, the calculated numerical data is input to the control means 60 shown in FIG. Then, based on the calculated numerical data, the holding table 13 is rotated while the X base 12 is moved in the X-axis direction under the control of the control means 60, and the division line L of the wafer W is moved to the gap 16 of the support table 20. The tip 43a of the blade 43 is moved to the inside, and the position is adjusted to a position at which the blade 43 can come into contact with the division line L.

  After the alignment is completed, as shown in FIG. 5A, the blade 43 is disposed above the surface Wa side of the wafer W and positioned so that the front end portion 43a faces the division line L of the wafer W. It is done. The control means 60 lowers the blade 43 in the Z-axis direction, and the tip 43a of the blade 43 presses the adhesive tape T as shown in FIG. Add.

  As a result, the inside of the wafer W that cannot withstand bending stress is cut along the division line L. When the vibration detector 50 shown in FIG. 3 detects a vibration amount equal to or greater than a threshold value stored in the control means 60 in advance, the vibration detector 50 sends a signal indicating that the wafer W has been cut to the control means 60. Send.

  When the control means 60 receives the cutting achievement signal, it determines that the cutting of the division line L of the wafer W has been achieved, and cuts the next division line L. Imaging processing by the IR camera 31, alignment, and application of bending stress by the blade 43 are applied to the next division line L, and these are repeated until all the division lines L are cut. After all the division lines L have been cut, the blade 43 is raised in the Z-axis direction, and the wafer W cutting process is completed.

  The IR camera 31 mounted on the braking apparatus 1 according to the present embodiment images the wafer W having the reflection film 4 processed to form a modified layer therein from the reflection film surface side, Since it is possible to detect the division line L in which the modified layer is formed inside, it is possible to align the position of the division line and the position of the blade. And because the wafer can be easily braked with the bending stress required for normal division, it is possible to prevent an increase in the number of chips that cannot be divided and the cracks that affect the processing of the wafer. Will improve.

  Note that the wafer W to be processed by the braking apparatus 1 according to the present invention may have a scribe line formed by a diamond scriber.

1: Braking device 2: Ring frame 3: Protective film 4: Reflective film 10: Device base 11: Guide rail 12: X base 12a: Moving part 120: Through hole 13: Holding stand: 130: Through hole 14: Drive part 15: Gear 16: Gap 20: Support base 21: Support rail 30: Imaging means 31: IR camera 32: Lens 33: Calculation unit 40: Stress applying means 41: Moving base 42: Guide rail 43: Blade 43a: Tip part 44: Drive motor 50: Vibration detector 60: Control means W: Wafer Wa: Front side Wb: Back side D: Device L: Divided line T: Adhesive tape

Claims (1)

In a braking device for cutting a workpiece by applying a bending stress by bringing a blade into contact with a division schedule line of the workpiece supported on the ring frame via an adhesive tape,
A pair of support rails standing in parallel with a predetermined gap near the center of the upper surface of the apparatus base, a support base for supporting a workpiece disposed at one end of the support rail, and disposed above the gap A blade capable of moving up and down, and imaging means disposed in the gap,
An X base that can move in the X direction is disposed on the upper surface of the apparatus base, and a through hole that accommodates the support base is formed at the center of the X base. As a holding stand for holding a rotatable ring frame,
The imaging means includes an IR camera that captures a line to be divided,
A calculation unit for calculating a shift amount between the X direction and the rotation direction from the captured image of the IR camera;
With
Breaking in which the X base and the holding table are operated from the numerical values of the calculation unit to move the division line of the workpiece to the inside of the gap of the support table, and the blade is lowered to cut the workpiece. apparatus.

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