JP2009148982A - Wafer breaking apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wafer breaking apparatus enabling automation of cutting of a substrate at low costs. <P>SOLUTION: The wafer breaking apparatus 10 includes a support base 30 supporting a substrate 1 having a cutting line 2 and a stress imparting section 50 applying a bending stress to the substrate 1 supported with the support base 30 by moving a blade 52 and cuts the substrate 1 along the cutting line 2. It also has a cutting detection section 76 which detects cutting of the substrate 1 by detecting vibrations of the support base 30. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a braking apparatus for cutting a substrate made of a brittle material such as a semiconductor wafer containing sapphire, silicon, indium phosphide, gallium arsenide, or the like.

  For example, in the manufacturing process of a semiconductor device, one surface of a substrate such as a semiconductor wafer or a sapphire substrate is partitioned into a plurality of regions by planned dividing lines formed in a lattice shape by a diamond blade or the like, and the substrate is aligned along the planned dividing lines. The individual chips are manufactured by cutting.

  As a braking device that cuts along the planned dividing line of the substrate, the substrate is fixed by sticking one surface opposite to the other surface on which the dividing line is formed on the lower surface of the adhesive sheet, and the upper surface of the cradle After the other side of the substrate is placed on the substrate, the blade lowered from above the adhesive sheet is pressed against one side of the substrate corresponding to the planned dividing line to apply bending stress to the substrate, thereby making the substrate into the planned dividing line. What cut | disconnects along is known (for example, refer patent document 1).

  In such a braking device, there may be a case where the substrate remains unbroken due to variations in the warp of the substrate, the thickness of the substrate, the depth of the ruled lines on the division lines provided on the substrate, and the like. When crack residue occurs, the operator stops the braking device, changes the position of the blade and the amount of stress to be applied, etc., then operates the braking device to reapply bending stress to the remaining crack and cut There is a need to. For this reason, during operation of the braking device, an operator must check whether there are any remaining cracks, and there is a problem that the braking device cannot be automated.

  On the other hand, if the bending stress applied to the substrate by the blade is increased, the generation of residual cracks can be suppressed. However, if the bending stress is increased, chipping such as cracks and chips is likely to occur, and the quality of the divided chip deteriorates. There's a problem.

  Therefore, a substrate support that supports the substrate and a break that is formed so as to extend along the scribe line of the substrate and that cuts the substrate by pressing the cutting position of the substrate supported by the substrate support. A break bar moving unit that moves the break bar in a first direction toward the substrate supported by the bar, the substrate support, and a second direction away from the substrate supported by the substrate support; and a break bar moving unit In a braking device comprising a movement control unit that controls the movement operation of the cutting, the break bar moving unit controlled by the movement control unit moves in the first direction and cuts at the cutting position by a break bar that presses the cutting position There has been proposed one provided with a cutting detection unit for detecting cutting of a substrate to be cut (for example, see Patent Document 2 below).

  However, since the cutting detection unit detects the breakage of the substrate by detecting the vibration of the break bar that moves when the substrate is cut, it is easily affected by vibrations caused by disturbances other than the vibration caused by the cutting of the substrate. Therefore, in addition to detecting the vibration of the break bar, it detects the vibration of the fixed bar that moves synchronously with the break bar and is not easily affected by the vibration that occurs when the substrate is cut, and the detected value from the break bar and the detected value from the fixed bar Therefore, it is necessary to detect the cutting of the substrate by canceling the vibration due to the disturbance based on the difference data, and there is a problem that a plurality of sensors for detecting the vibration are required and the manufacturing cost increases.

In addition, if the substrate has already been cleaved before the break bar presses the cutting position due to vibration during transportation, etc., the above-mentioned cutting detection unit can detect the cut regardless of how much the break bar presses the substrate. Therefore, there is a problem that the presence or absence of substrate cutting cannot be detected accurately.
JP 2007-55197 A JP 2006-245263 A

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a braking device that can automate the cutting of a substrate at a low cost while suppressing deterioration in quality of divided chips. .

  A braking apparatus according to the present invention includes a support base that supports a substrate on which a division line is formed, and a stress applying unit that applies a bending stress to the substrate supported by the support base by moving a blade. And a braking device that cuts the substrate along the planned dividing line, further comprising a cutting detection unit that detects the cutting of the substrate by detecting vibration of the support base.

  In the present invention, since the cutting detection unit for detecting the cutting of the substrate is provided, it is not necessary for the operator to check whether there is any crack remaining on the device, and the braking device can be automated. In addition, since the cutting detection unit detects the substrate cutting by detecting the vibration of the support base, it is less susceptible to the vibration caused by the movement of the blade, and whether or not the substrate is cut accurately without providing a plurality of sensors. Can be detected.

  In the above invention, the cutting detection unit includes an imaging unit that images the division line of the substrate supported by the support, and the imaging unit in a state where the stress applying unit applies a bending stress to the substrate. The cutting of the substrate may be detected by imaging the planned dividing line, and the cutting of the substrate is accurately detected even when the substrate is already cleaved before the blade applies bending stress. be able to.

  Moreover, in the said invention, after the said stress application part gives bending stress to the said board | substrate, when the cutting | disconnection detection part does not detect the cutting | disconnection of the said board | substrate, bending stress larger than the bending stress which the said stress application part provided last time is applied. You may re-apply to the said board | substrate.

  According to the present invention, a braking device that cuts a substrate without deteriorating the quality of divided chips can be automated at a low cost.

  Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view of a braking device 10 according to the present embodiment, FIG. 2 is an enlarged perspective view showing a main part of the braking device 10, and FIG. 3 is a substrate holding state in which a substrate is held. FIG. 4 is a cross-sectional view schematically showing the braking device 10.

  As shown in FIGS. 1 and 2, the braking device 10 according to the present embodiment cuts a sapphire substrate (hereinafter referred to as a substrate) 1 in which a plurality of semiconductor elements such as LEDs are formed in a lattice shape. A device for separating each semiconductor element, including a substrate holding unit 20, a support base 30, a stress applying unit 50, a cutting detection unit 70, and a control unit 90 for driving and controlling these components, and a base in which each component is horizontally arranged It is disposed on the part 11.

  As shown in FIG. 3, the substrate holding unit 20 includes an adhesive sheet 22 and an annular sheet holding frame 24, and the adhesive sheet 22 is stretched on the inner side of the sheet holding frame 24. The movable table 12 is detachably fixed. The pressure-sensitive adhesive sheet 22 is made of a material such as a vinyl sheet or a polyester sheet having elasticity such as a synthetic resin. The pressure-sensitive adhesive is applied to one surface and the one surface 1a of the substrate 1 is adhered to the substrate 1 as a substrate. It is fixed to the holding part 20. Further, a protective sheet 30a made of a transparent resin is disposed on the other surface 1b side of the substrate 1, and the substrate 1 comes into contact with the support base 30 via the protective sheet 30a.

  The substrate 1 fixed to the substrate holding unit 20 has a grid-like ruled line streak as the planned dividing line 2 on the other surface 1b opposite to the one surface 1a of the substrate 1 by a scriber such as a diamond needle or a diamond blade. .

  The moving table 12 includes an X table 13 installed on the base portion 11 and a cylindrical θ table 14 installed on the X table 13.

  The X table 13 is provided on the base portion 11 so as to be slidable on a guide rail 15 extending in the X axis direction shown in the drawing, and is configured to be reciprocally movable in the X axis direction by an X table drive motor 16. The X table 13 is provided with a through hole 17, and the θ table 14 is inserted into the through hole 17 so as to be rotatable about the Z axis corresponding to the vertical direction with respect to the X table 13.

  The θ table 14 is a member that removably fixes the substrate holding unit 20. In this embodiment, the substrate holding unit 20 is fixed to the θ table 14 with the substrate 1 attached to the adhesive sheet 22 facing downward. The The θ table 14 includes a hollow portion 14 a corresponding to the inside of the sheet holding frame 24 in a state where the substrate holding portion 20 is mounted, and the Z axis is connected via a gear 18 a connected to the drive shaft of the θ table drive motor 18. It is configured to be rotatable around.

  Thereby, the substrate holding part 20 fixed on the θ table 14 is movable in the X axis direction and around the θ axis with respect to the base part 11.

  Below the hollow portion 14 a of the θ table 14, a pair of support tables 30, 30 fixed to the base portion 11 via the mounting base 32 are disposed at a predetermined interval in the X-axis direction. A gap 34 is formed between 30 and 30, and the upper surface of the support base 30 faces the other surface 1 b of the substrate 1 attached to the substrate holding unit 20.

  The support 30 supports the other surface 1b of the substrate 1 when stress is applied from the stress applying unit 50, and the Y-axis direction (direction orthogonal to the X-axis and Z-axis) of the substrate 1 to be cut. It is formed in the size which can fully cover.

  As shown in FIG. 1, the stress applying means 50 includes a blade 52 disposed above a gap 34 formed between a pair of support bases 30, 30, and a Z axis (up and down) while the blade 52 is fixed. A guide rail 56 extending in a direction is provided so as to be slidable. A base drive motor 58 controls the rotation of a ball screw (not shown) so that the blade 52 fixed to the slide base 57 is axially moved. The amount of displacement is controlled so as to be able to reciprocate.

  The cutting detection unit 70 detects cutting of the substrate 1 to which bending stress is applied by the stress applying unit 50, and is supported by the vibration detection unit 72 that detects vibration of the support base 30 and the support base 30. And an image processing unit 74 that images the planned division line 2 of the substrate 1.

  The vibration detection unit 72 includes a contact type vibration sensor 76 disposed in the vicinity of the mounting base 32 on the base unit 11, and the stress applying unit 50 applies a predetermined amount of bending stress to the substrate 1 to be cut. When the vibration of the support base 30 transmitted through the mounting base 32 is detected, and the vibration of a predetermined value or more is detected, a cutting signal is output to the control unit 90 because the cutting of the substrate 1 is detected.

  The image processing unit 74 detects the cutting of the substrate 1 based on the image data captured by the camera 78 disposed below the gap 34 formed between the pair of support tables 30.

  Specifically, the camera 78 is adjusted so that the planned division line 2 formed on the other surface 1b side of the substrate 1 attached to the adhesive sheet 22 with the lens facing upward is in the field of view.

  Then, as shown in FIG. 5A, the blade 52 is not in contact with the adhesive sheet 21 of the substrate holding part 20 and no bending stress is applied to the substrate 1, and as shown in FIG. In this state, the dividing line 2 is imaged by the camera 78 in each state where the adhesive sheet 21 of the substrate holding unit 20 is pressed and bending stress is applied to the substrate 1. When each pixel of the obtained image data is binarized and the bending stress is applied from a state where no bending stress is applied, the low level change amount corresponding to the dark spot is greater than or equal to a predetermined value, the image processing unit 74 outputs a cutting signal to the controller 90, assuming that the substrate 1 is cut.

  When the substrate 1 is not cut, there is almost no change in the brightness in the vicinity of the planned dividing line 2 even if the bending stress is applied from the state where the bending stress is not applied, but when the substrate 1 is cut, the bending stress As shown in FIG. 5B, the brightness of the position corresponding to the planned dividing line 2 is changed by spreading downward while the cut portion is widened, so that the change in the level of the substrate 1 from the low level corresponding to the dark spot is changed. Disconnection can be detected.

  Further, the image processing unit 74 recognizes the position of the planned cutting line 2 based on the image data picked up by the camera 78 when the substrate holding unit 20 is fixed to the θ table 14 of the moving table 12, and this is determined in advance. By comparing with the stored position of the blade edge 52a of the blade 52, the amount of deviation between the position of the blade edge 52a of the blade 52 and the expected cutting line 2 in the horizontal plane (XY plane) is the displacement amount Δx in the X-axis direction. And a displacement amount Δθ around the θ axis, and the displacement amount Δx and the displacement amount Δθ are input to the control unit 90.

  The control unit 90 includes a computer and, as shown in FIG. 6, based on various data input from the vibration detection unit 72 and the image processing unit 74, the X table driving motor 16, the θ table driving motor 18, and the base driving. The operation of the braking device 10 is controlled by driving and controlling the motor 58 and the like.

  Next, the cutting operation of the substrate 1 by the braking device 10 will be described.

  First, the substrate holding part 20 in which the one surface 1a of the substrate 1 is adhered to the adhesive sheet 22 is moved so that the other surface 1b of the substrate 1 on which the planned dividing line 2 is formed is opposed to the support 30 via the protective sheet 30a. When set on the θ table 14 of the table 12, alignment of the planned dividing line 2 of the substrate 1 and the cutting edge 52 a of the blade 52 is performed.

  In this alignment, as described above, the amount of deviation between the position of the blade edge 52a of the blade 52 and the planned cutting line 2 based on the image data picked up by the image processing unit 74 by the camera 78 is the displacement amount Δx in the X-axis direction. And a displacement amount Δθ around the θ axis. Receiving the input of the displacement amount Δx in the X-axis direction and the displacement amount Δθ around the θ-axis, the control unit 90 drives and controls the X-table driving motor 16 and the θ-table driving motor 18 to move the moving table 12 in the X-axis direction and the θ-direction. The position of the substrate holder 20 is adjusted so that the displacement amount Δx and the displacement amount Δθ become zero.

  When the alignment is completed, the control unit 90 drives and controls the base drive motor 58 to lower the blade 52 fixed to the sliding base 57, and a predetermined distance (from the position where the blade edge 52a of the blade 52 abuts the adhesive sheet 22). By pressing the adhesive sheet 22 downward (for example, 80 μm), a predetermined amount of bending stress is applied to the substrate 1, and then the blade 52 is raised until it is separated from the adhesive sheet 22 to stop the pressing.

  When the cutting signal is input to the control unit 90 from at least one of the vibration detection unit 72 and the image processing unit 74 constituting the cutting detection unit 70 while the blade 52 applies bending stress to the substrate 1, Assuming that the substrate 1 has been cut, the movable stage 12 is moved in the X-axis direction to cut the next division line 2 and the adjacent division line 2 is moved directly below the cutting edge 52a of the blade 52 to perform the next division. The planned line 2 is cut.

  On the other hand, if the cutting signal is not input to the control unit 90 from either the vibration detection unit 72 or the image processing unit 74 while the blade 52 applies bending stress to the substrate 1, the substrate 1 is not cut. The control unit 90 controls the drive of the base drive motor 58 to lower the blade 52 fixed to the sliding base 57, and sets a value larger than the previous value from the position where the blade edge 52a of the blade 52 contacts the adhesive sheet 22. By pressing the adhesive sheet 22 below the predetermined distance (for example, 100 μm), a bending stress larger than the bending stress applied to the substrate 1 is applied again. When a cutting signal is input from at least one of the vibration detection unit 72 and the image processing unit 74 while the second bending stress is applied, the moving stage is used to cut the next division line 2 as described above. 12 is moved in the X-axis direction, and when a cutting signal is not input, a bending stress larger than the bending stress applied last time (second time) is applied again, and thereafter cutting is performed from at least one of the vibration detection unit 72 and the image processing unit 74. Until a signal is input to the control unit 90, a bending stress greater than the bending stress previously applied is repeatedly applied.

  Then, the bending stress is applied, the cutting is confirmed, and the movement of the substrate 1 in the X-axis direction is repeated to cut all the planned dividing lines 2 along the Y-axis direction. When cutting has been completed for all the planned dividing lines 2 along the Y-axis direction, the control unit 90 drives the θ table drive motor 18 to rotate the θ table 14 by 90 degrees. Then, with respect to the planned division line 2 orthogonal to the planned division line 2 that has been cut, all the planned division lines are repeated by repeatedly applying bending stress, confirming the cutting, and moving the substrate 1 in the X-axis direction, as described above. Cut 2

  As described above, since the braking device 10 according to the present embodiment includes the cutting detection unit 70 that detects the cutting of the substrate 1, it is not necessary for the operator to check whether there is any remaining cracks. The braking device 10 can be automated. Moreover, the cutting detection unit 70 cuts the substrate 1 by detecting the vibration of the support table 30 transmitted through the mounting table 32 by the vibration sensor 76 disposed on the base unit 11 in the vicinity of the mounting table 32. Therefore, it is difficult to be affected by the vibration caused by the movement of the blade 52, and the presence or absence of cutting of the substrate 1 can be accurately detected without providing a plurality of sensors.

  In addition, the cutting detection unit 70 includes an image processing unit 74 that detects the cutting of the substrate 1 by imaging the division line 2 of the substrate 1 supported by the support base 30 by the camera 78, so that the blade 52 is the substrate. Even if it is already cut before applying bending stress to 1 and the vibration sensor 76 cannot detect the cutting of the substrate 1, the cutting of the substrate 1 can be reliably detected.

  Furthermore, if the cutting of the substrate 1 is not detected by the cutting detection unit 70 even if the stress applying unit 50 applies a bending stress to the substrate 1, a bending stress larger than the bending stress previously applied by the stress applying unit 50 is applied again. Therefore, the bending stress to be applied to the substrate 1 can be set small, and the occurrence of remaining cracks can be suppressed while suppressing the occurrence of chipping such as cracks and chips.

  In the present embodiment, it is configured to repeatedly apply a stress larger than the bending stress applied last time until a cutting signal is input from the cutting detection unit 70. However, for example, a bending stress that repeatedly increases a predetermined number of times is applied. Even if the cutting signal is not input from the cutting detector 70, the cutting operation may be stopped and the braking device 10 may be stopped because an abnormality has occurred.

  Further, in the present embodiment, the image processing unit 74 cuts the substrate 1 from the amount of change in the dark spot in the image data between the state where the bending stress is not applied to the substrate 1 and the state where the bending stress is applied. Although detected, for example, as shown in FIG. 7, a mark is set at a predetermined position such as a circuit pattern P of a semiconductor element formed on the substrate 1, and the X axis of the mark before and after the bending stress is applied to the substrate 1. If the movement amount (displacement amount) in the direction is equal to or greater than a predetermined value, the substrate 1 may be detected as having been cut.

It is a perspective view of the braking device concerning one embodiment of the present invention. It is a perspective view of the braking device concerning one embodiment of the present invention, and shows the state where a substrate holding part was removed. It is a top view of the board | substrate holding means which shows the state with which the board | substrate was hold | maintained. 1 is a cross-sectional view schematically showing a braking device according to an embodiment of the present invention. It is sectional drawing of the board | substrate holding part which hold | maintained the board | substrate, Comprising: (a) is before board | substrate cutting | disconnection, (b) shows after board | substrate cutting | disconnection. It is a block diagram which shows the control structure of the braking device concerning one Embodiment of this invention. It is a top view which expands and shows the principal part of the board | substrate of cutting object.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Board | substrate 2 ... Dividing planned line 10 ... Braking apparatus 11 ... Base part 20 ... Board | substrate holding | maintenance part 30 ... Support stand 50 ... Stress applying part 52 ... Blade 70 ... Cutting | disconnection detection part 72 ... Vibration detection part 74 ... Image processing part 76 ... Vibration sensor 78 ... Camera 90 ... Control unit

Claims (3)

  A support base that supports the substrate on which the planned dividing line is formed, and a stress applying unit that applies a bending stress to the substrate supported by the support base by moving a blade, along the planned dividing line A braking apparatus for cutting the substrate, comprising: a cutting detection unit for detecting vibration of the support base to detect cutting of the substrate.   The cutting detection unit includes an imaging unit that images the planned dividing line of the substrate supported by the support base, and the dividing unit is scheduled to be divided by the imaging unit in a state where the stress applying unit applies a bending stress to the substrate. The braking device according to claim 1, wherein the cutting of the substrate is detected by imaging a line.   After the stress applying unit applies a bending stress to the substrate, if the cutting of the substrate is not detected by the cutting detection unit, the stress applying unit applies again a bending stress larger than the bending stress applied last time by the stress applying unit. The braking device according to claim 1 or 2, characterized in that.

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