JP2020191356A - Method for dividing workpiece, method for detecting chip dimension and cutting device - Google Patents

Abstract

To provide a method for dividing a workpiece capable of easily detecting the dimensions of a chip.SOLUTION: A method for dividing a workpiece for dividing a workpiece into a plurality of chips to detect the actual dimensions of a chip by a cutting device including holding means for holding a workpiece having an electrode in each of a plurality of areas partitioned by a plurality of division schedule lines crossing each other, cutting means mounted with a cutting blade for cutting the workpiece held by the holding means, imaging means for imaging the workpiece and control means for controlling the holding means and the cutting means, includes: a division step for cutting the workpiece along the division schedule lines by the cutting blade to divide the workpiece into a plurality of chips; an image acquisition step for imaging a chip with the imaging means to acquire an image of the chip; and a detection step for detecting the actual dimensions of the chip with the control means on the basis of the image.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for dividing a work piece into a plurality of chips, a method for detecting the size of a chip for detecting the size of the chip, and a cutting device capable of detecting the size of the chip. ..

By coating a plurality of device chips arranged on the base substrate with a sealing material (mold resin) made of resin, a package substrate such as a QFN package (Quad For Non-Lead Package) substrate is formed. By dividing this package substrate along a planned division line (street), a plurality of chips (package devices) including device chips can be obtained.

For the division of the workpiece represented by the package substrate, for example, a cutting apparatus including a chuck table for holding the workpiece and a cutting unit on which an annular cutting blade for cutting the workpiece is mounted. Is used (see, for example, Patent Document 1). While the work piece is held by the chuck table, the work piece is cut and divided into a plurality of chips by rotating the cutting blade to cut into the work piece.

JP-A-2017-50309

After the work piece is divided into a plurality of chips, work is performed to confirm whether or not a desired chip is obtained. For example, the dimensions of the insert obtained by dividing the workpiece (the size of the entire insert, the positions of the electrodes provided on the insert, etc.) are measured, and the process capability index is calculated based on the actual dimensions of the insert. Then, the chip is evaluated based on the actual size of the chip and the process capability index.

The dimensions of the chip are measured, for example, by a chip evaluator using a microscope. In this case, the evaluator needs to perform operations such as alignment of the microscope and the chip, measurement of the chip dimensions, and recording of the measured chip dimensions individually for each chip. Therefore, especially when evaluating a large number of chips, it takes a huge amount of time and effort to evaluate the chips.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a method for dividing a workpiece, a method for detecting the size of a chip, and a cutting apparatus capable of easily detecting the size of a chip.

According to one aspect of the present invention, a holding means for holding a work piece having electrodes in a plurality of regions partitioned by a plurality of planned division lines intersecting with each other, and the work piece held by the holding means. A cutting device equipped with a cutting means to which a cutting blade for cutting a cutting blade is mounted, an imaging means for imaging the work piece, and a control means for controlling the holding means and the cutting means. It is a method of dividing a work piece by dividing it into a plurality of chips and detecting the actual size of the chip, and the work piece is cut by the cutting blade along the planned division line into a plurality of the chips. A division step for dividing, an image acquisition step for capturing an image of the chip with the imaging means and acquiring an image of the chip, and a detection step for detecting the actual size of the chip with the control means based on the image. A method of dividing a workpiece comprising ,, is provided.

It should be noted that preferably, the method of dividing the workpiece further includes a calculation step of calculating a value indicating the degree of variation in the actual size of the chip by the control means. Further, preferably, in the division step, the workpiece is divided in a state of being held by the holding means, and in the image acquisition step, the workpiece is imaged in a state of being held by the holding means. ..

Further, according to one aspect of the present invention, a holding means for holding a workpiece having electrodes in a plurality of regions partitioned by a plurality of scheduled division lines intersecting with each other, and the covering held by the holding means. A cutting device provided with a cutting means on which a cutting blade for cutting a work piece is mounted, an imaging means for imaging the work piece, and a control means for controlling the holding means and the cutting means. This is a chip size detection method in which an object is divided into a plurality of chips to detect the actual size of the chip, and the workpiece is cut along the planned division line by the cutting blade to perform the plurality of chips. An image acquisition step of capturing an image of the chip with the imaging means and acquiring an image of the chip, and a detection step of detecting the actual size of the chip with the control means based on the image. A method for detecting the dimensions of a chip comprising the above is provided.

It should be noted that preferably, the chip size detection method further includes a calculation step of calculating a value indicating the degree of variation in the actual size of the chip by the control means. Further, preferably, in the division step, the workpiece is divided in a state of being held by the holding means, and in the image acquisition step, the workpiece is imaged in a state of being held by the holding means. ..

Further, according to one aspect of the present invention, a holding means for holding the work piece, a cutting means on which a cutting blade for cutting the work piece held by the holding means is mounted, and the work piece are provided. A cutting device including an imaging means for imaging, a holding means, and a control means for controlling the cutting means. The imaging means captures the workpiece divided into a plurality of chips by the cutting blade. The control means is provided with a cutting device including a detection unit that detects the actual size of the chip based on the image by taking an image and acquiring an image of the chip.

It is preferable that the control means has a storage unit that stores a preset reference value of the size of the chip, an actual size of the chip, and a variation in the actual size of the chip based on the reference value. A calculation unit for calculating a value indicating the degree of is further provided. Further, preferably, the cutting device further includes a display means for displaying the value calculated by the calculation unit.

The cutting apparatus according to one aspect of the present invention includes an imaging means for imaging a workpiece divided into a plurality of chips and a control means for detecting the actual size of the chip based on the image of the chip acquired by the imaging. Be prepared. As a result, the size of the chip can be automatically measured by the cutting device, and the detection of the size of the chip is simplified.

It is a perspective view which shows the cutting apparatus. FIG. 2A is a plan view showing the work piece, FIG. 2B is a bottom view showing the work piece, and FIG. 2C is an enlarged plan view showing the work piece. .. It is a top view which shows the workpiece supported by an annular frame. It is a partial cross-sectional side view which shows the workpiece held by a chuck table. It is a top view which shows the work piece after division in an enlarged manner. It is a schematic diagram which shows the structural example of the image pickup unit.

Hereinafter, the present embodiment will be described with reference to the accompanying drawings. First, a configuration example of the cutting device according to the present embodiment will be described. FIG. 1 is a perspective view showing a cutting device 2.

The cutting device 2 includes a base 4 that supports each component constituting the cutting device 2. An opening 4a is formed in the front corner of the base 4, and a cassette support 6 that moves up and down by an elevating mechanism (not shown) is provided inside the opening 4a. Further, a cassette 8 capable of accommodating a plurality of workpieces 11 (see FIGS. 2A and 2B) to be cut by the cutting device 2 is arranged on the cassette support 6. Note that FIG. 1 shows only the outline of the cassette 8 for convenience of explanation.

FIG. 2A is a plan view showing the workpiece 11, and FIG. 2B is a bottom view showing the workpiece 11. In this embodiment, a case where the workpiece 11 is a package substrate will be described. For example, as the workpiece 11, a package substrate such as a CSP (Chip Size Package) substrate or a QFN package (Quad For Non-Lead Package) substrate is used.

The workpiece 11 includes a plate-shaped base substrate 13 having a front surface 13a and a back surface 13b and formed in a rectangular shape in a plan view. The base substrate 13 is formed by using a metal such as 42 alloy (an alloy of iron and nickel) or copper. However, there are no restrictions on the material, shape, structure, size, etc. of the base substrate 13.

On the back surface 13b side of the base substrate 13, a plurality of device chips (not shown) including devices made of ICs (Integrated Circuits), LSIs (Large Scale Integration), and the like are arranged. The device chip is covered and sealed with a resin layer (mold resin) 15 formed on the back surface 13b side of the base substrate 13. There are no restrictions on the type, quantity, shape, structure, size, arrangement, etc. of the device chips.

As shown in FIG. 2A, the workpiece 11 is divided into a plurality of device regions 11a by a plurality of scheduled division lines (streets) 17 arranged in a grid pattern so as to intersect each other. The device chips formed on the back surface 13b side of the base substrate 13 are respectively arranged in the device region 11a. By dividing the workpiece 11 along the scheduled division line 17, each device region 11a is separated, and a plurality of chips (package devices) including device chips sealed with a resin can be obtained.

FIG. 2C is an enlarged plan view of the workpiece 11. The workpiece 11 includes a plurality of electrodes 19 formed on the surface of the device region 11a. The electrodes 19 are formed in a spherical shape, for example, and are arranged so as to be exposed on the surface 13a side of the base substrate 13. FIG. 2C shows an example in which two rows of electrodes 19 are arranged along the outer peripheral edge (contour) of the device region 11a.

For example, the electrode 19 is connected to a device chip arranged on the back surface 13b side of the base substrate 13 via a metal wire (not shown) or the like. The electrode 19 functions as a connection electrode when the workpiece 11 is divided into a plurality of chips and then the chips are mounted on another mounting substrate or the like.

Although the case where the workpiece 11 is a package substrate will be described here, there are no restrictions on the type, material, shape, structure, size, etc. of the workpiece 11. For example, the workpiece 11 is a semiconductor wafer or the like in which devices such as ICs (Integrated Circuits) and LSIs (Large Scale Integration) are formed in a plurality of regions partitioned by a plurality of scheduled division lines intersecting each other. May be good. The device may also include electrodes that are exposed on the surface.

When the workpiece 11 is cut by the cutting device 2 (see FIG. 1), the workpiece 11 is supported by an annular frame. FIG. 3 is a plan view showing the workpiece 11 supported by the annular frame 23.

A circular tape 21 having a diameter capable of covering the entire workpiece 11 is attached to the back surface side (resin layer 15 (see FIG. 2B)) of the workpiece 11. The tape 21 is a flexible film obtained by forming a rubber-based or acrylic-based adhesive layer (glue layer) on a base material made of a resin such as polyolefin, polyvinyl chloride, or polyethylene terephthalate.

An annular frame 23 is attached to the outer peripheral portion of the tape 21. The frame 23 includes a circular opening 23a having a diameter capable of accommodating the workpiece 11. The workpiece 11 is supported by the frame 23 via the tape 21 in a state of being arranged inside the opening 23a so that the surface side (the surface 13a side of the base substrate 13) is exposed upward.

The tape 21 may be attached to the surface side of the workpiece 11. In this case, the workpiece 11 is supported by the frame 23 with the back surface side (resin layer 15 side) exposed upward. Further, a plurality of workpieces 11 may be attached to the tape 21. In this case, a frame 23 having an opening 23a having a diameter capable of accommodating a plurality of workpieces 11 is used.

Further, the workpiece 11 does not necessarily have to be supported by the frame 23. When the frame 23 is not used, for example, a rectangular tape formed in substantially the same shape and size as the workpiece 11 is attached to the front surface side or the back surface side of the workpiece 11.

The workpiece 11 supported by the frame 23 is housed in the cassette 8 shown in FIG. Then, the cassette 8 containing the plurality of workpieces 11 is arranged on the cassette support 6.

A rectangular opening 4b whose longitudinal direction is along the X-axis direction (machining feed direction, front-rear direction) is formed on the side of the cassette support 6. Inside the opening 4b, a ball screw type X-axis moving mechanism 10 and a dust-proof and drip-proof cover 12 covering the upper part of the X-axis moving mechanism 10 are arranged. The X-axis moving mechanism 10 includes an X-axis moving table 10a, and moves the X-axis moving table 10a along the X-axis direction.

Further, on the side of the cassette support 6, a temporary placement mechanism 14 for temporarily placing the workpiece 11 is arranged so as to overlap the opening 4b. The temporary placement mechanism 14 includes a pair of guide rails 14a and 14b that approach and separate from each other while maintaining a state substantially parallel to the Y-axis direction (indexing feed direction, left-right direction). The guide rails 14a and 14b sandwich the workpiece 11 along the X-axis direction and align it with a predetermined position.

A chuck table (holding table, holding means) 16 for holding the workpiece 11 is provided on the X-axis moving table 10a. The chuck table 16 is connected to a rotation drive source (not shown) such as a motor, and the rotation drive source rotates the chuck table 16 around a rotation axis substantially parallel to the Z-axis direction (vertical direction, vertical direction). Let me. Further, the chuck table 16 is moved along the X-axis direction by the X-axis moving mechanism 10.

The upper surface of the chuck table 16 constitutes a holding surface 16a for holding the workpiece 11. The holding surface 16a is formed substantially parallel to the X-axis direction and the Y-axis direction, and is connected to a suction source (not shown) such as an ejector via a suction path (not shown) provided inside the chuck table 16. Has been done. Further, around the chuck table 16, four clamps 18 are provided to grip and fix the annular frame 23 (see FIG. 3) that supports the workpiece 11.

A transport mechanism (not shown) for transporting the workpiece 11 housed in the cassette 8 to the chuck table 16 is provided in the vicinity of the opening 4b. The workpiece 11 is conveyed by a conveying mechanism, and is arranged on the holding surface 16a of the chuck table 16 so that, for example, the surface side (the surface 13a side of the base substrate 13 (see FIG. 3)) is exposed upward.

A gate-shaped support structure 20 is arranged on the upper surface of the base 4 so as to straddle the opening 4b. The support structure 20 supports two sets of cutting units (cutting means) 22 that perform cutting on the workpiece 11 held by the chuck table 16. Further, two sets of moving mechanisms 24 for moving the cutting unit 22 along the Y-axis direction and the Z-axis direction are mounted on the upper portion of the support structure 20 on the front surface side.

Each of the moving mechanisms 24 is mounted on a pair of Y-axis guide rails 26 arranged along the Y-axis direction on the front surface side of the support structure 20. Specifically, the moving mechanism 24 includes a Y-axis moving plate 28, and the Y-axis moving plate 28 is attached to the Y-axis guide rail 26 in a slidable state along the Y-axis guide rail 26. ..

A nut portion (not shown) is provided on the rear surface (back surface) side of the Y-axis moving plate 28, and a Y-axis ball screw 30 arranged substantially parallel to the Y-axis guide rail 26 is screwed into this nut portion. Has been done. A Y-axis pulse motor 32 is connected to one end of the Y-axis ball screw 30. When the Y-axis ball screw 30 is rotated by the Y-axis pulse motor 32, the Y-axis moving plate 28 moves in the Y-axis direction along the Y-axis guide rail 26.

A pair of Z-axis guide rails 34 arranged along the Z-axis direction are provided on the front surface (front surface) side of the Y-axis moving plate 28. A Z-axis moving plate 36 is attached to the Z-axis guide rail 34 in a slidable state along the Z-axis guide rail 34.

A nut portion (not shown) is provided on the rear surface (back surface) side of the Z-axis moving plate 36, and a Z-axis ball screw 38 arranged substantially parallel to the Z-axis guide rail 34 is screwed into the nut portion. Has been done. A Z-axis pulse motor 40 is connected to one end of the Z-axis ball screw 38. When the Z-axis ball screw 38 is rotated by the Z-axis pulse motor 40, the Z-axis moving plate 36 moves in the Z-axis direction along the Z-axis guide rail 34.

A cutting unit 22 is fixed to the lower part of the Z-axis moving plate 36. The cutting unit 22 includes a cylindrical spindle (not shown) arranged substantially parallel to the Y-axis direction. An annular cutting blade 42 for cutting the workpiece 11 is mounted on one end side (tip portion) of the spindle. The cutting blade 42 is formed by fixing abrasive grains made of, for example, diamond, cubic boron nitride (cBN), etc. with a bonding material made of metal, ceramics, resin, or the like.

Further, a rotation drive source (not shown) such as a motor for rotating the spindle is connected to the other end side (base end portion) of the spindle. When the spindle is rotated by a rotary drive source with the cutting blade 42 mounted on the tip of the spindle, the cutting blade 42 is rotated by the power transmitted from the rotary drive source via the spindle.

An imaging unit (imaging means) 44 for imaging the workpiece 11 or the like is provided at a position adjacent to the cutting unit 22. When the Y-axis moving plate 28 is moved in the Y-axis direction by the moving mechanism 24, the cutting unit 22 and the imaging unit 44 move along the Y-axis direction. Further, when the Z-axis moving plate 36 is moved in the Z-axis direction by the moving mechanism 24, the cutting unit 22 and the imaging unit 44 move along the Z-axis direction. Based on the image of the workpiece 11 acquired by the imaging unit 44, the chuck table 16 holding the workpiece 11 and the cutting unit 22 are aligned.

An opening 4c is formed at a position opposite to the opening 4a with respect to the opening 4b. A cleaning unit 46 for cleaning the workpiece 11 is arranged inside the opening 4c. The workpiece 11 machined by the cutting unit 22 is transported from the chuck table 16 to the cleaning unit 46 by a transport mechanism (not shown) and cleaned. Then, the work piece 11 after cleaning is housed in the cassette 8 by the transport mechanism.

Further, the cutting device 2 is provided with a display unit (display means) 48 for displaying various information related to the processing of the workpiece 11. The display unit 48 is composed of, for example, a touch panel type monitor that serves as a user interface. In this case, the operator of the cutting device 2 can input information such as machining conditions into the monitor.

Further, each component (X-axis moving mechanism 10, temporary placing mechanism 14, chuck table 16, cutting unit 22, moving mechanism 24, imaging unit 44, cleaning unit 46, etc.) constituting the cutting device 2 is attached to the cutting device 2. It is connected to the provided control unit (control means) 60. The control unit 80 is configured by, for example, a computer or the like, and controls the operation of each component.

The work piece 11 is cut along the scheduled division line 17 (see FIG. 3) by the cutting device 2, and is divided into a plurality of chips. Further, the size of the chip obtained by dividing the workpiece 11 is detected by the cutting device 2. Hereinafter, specific examples of the method of dividing the workpiece and the method of detecting the size of the chip using the cutting device 2 will be described.

First, the workpiece 11 housed in the cassette 8 is conveyed to the temporary placement mechanism 14 by a transfer mechanism (not shown). Then, after the work piece 11 is aligned by the temporary placement mechanism 14, the work piece 11 is conveyed onto the holding surface 16a of the chuck table 16 and held by the chuck table 16.

FIG. 4 is a partial cross-sectional side view showing the workpiece 11 held by the chuck table 16. The workpiece 11 is placed on the chuck table 16 so that, for example, the front surface side (the surface 13a side of the base substrate 13) is exposed upward and the back surface side (the resin layer 15 side) faces the holding surface 16a. Be placed. Further, the frame 23 that supports the workpiece 11 is fixed by the clamp 18. In this state, when the negative pressure of the suction source is applied to the holding surface 16a, the workpiece 11 is sucked and held by the chuck table 16 via the tape 21.

Next, the chuck table 16 is rotated to align the length direction of one scheduled division line 17 (see FIG. 3) with the X-axis direction. The height of the cutting unit 22 is such that the lower end of the cutting blade 42 is arranged below the back surface of the workpiece 11 (upper surface of the tape 21) and above the holding surface 16a (lower surface of the tape 21). To adjust. Further, the position of the cutting unit 22 in the Y-axis direction is adjusted so that the cutting blade 42 is arranged on the extension line of the one scheduled division line 17.

Then, the chuck table 16 is moved along the X-axis direction while rotating the cutting blade 42. As a result, the chuck table 16 and the cutting unit 22 move relatively along the scheduled division line 17, and the cutting blade 42 cuts into the workpiece 11. As a result, the workpiece 11 is cut along the scheduled division line 17 and divided.

After that, the same procedure is repeated to cut the workpiece 11 along all the planned division lines 17. As a result, the device region 11a (see FIG. 3) of the workpiece 11 is fragmented, and the workpiece 11 is divided into a plurality of chips (division step).

FIG. 5 is an enlarged plan view showing the work piece 11 after division. The workpiece 11 is divided into a plurality of chips (package devices) 25 each having a plurality of electrodes 19. Further, in the region of the workpiece 11 cut by the cutting blade 42, a calf (cut end) 11b extending from the front surface to the back surface of the workpiece 11 is formed. The width of the calf 11b corresponds to the thickness of the cutting blade 42 (see FIG. 4). In FIG. 5, the region where the calf 11b is formed is hatched.

After the work piece 11 is divided, work is performed to confirm whether or not a chip 25 having a desired size is obtained. Specifically, the dimensions of the chip 25 (the size of the entire chip 25, the position of the electrode 19 included in the chip 25, etc.) obtained by dividing the workpiece 11 are measured, and the chip 25 is based on the actual size of the chip 25. Is evaluated.

When detecting the actual size of the chip 25, first, an image of the chip 25 is acquired by imaging the chip 25 with the image pickup unit 44 (see FIG. 1) (image acquisition step). In the image acquisition step, the work piece 11 is imaged while being held by the chuck table 16.

FIG. 6 is a schematic view showing a configuration example of the imaging unit 44. The image pickup unit 44 includes a housing 60 that houses each component constituting the image pickup unit 44. A partition wall 62 that separates the inside and the outside of the housing 60 is provided at the tip (lower end) of the housing 60. The partition wall 62 is arranged above the lower end 60a of the housing 60. The partition wall 62 is provided with an opening that penetrates the partition wall 62 up and down, and the opening is provided with a light transmitting portion 64 made of a transparent member. Further, the housing 60 houses the objective lens 66 arranged on the upper side of the partition wall 62.

The space 68 surrounded by the tip end portion of the housing 60 and the partition wall 62 is connected to the water source 72 via the water supply port 60b formed in the housing 60 and the valve 70. At the time of imaging the workpiece 11, the imaging unit 44 is positioned so that the distance between the lower end 60a of the housing 60 and the surface of the workpiece 11 is, for example, about 0.5 mm or more and 1 mm or less. Further, water is supplied from the water source 72 to the space 68 through the valve 70 and the water supply port 60b at a predetermined flow rate, and the space 68 is filled with water.

Further, the image pickup unit 44 includes a strobe light source 74 that irradiates strobe light. As the strobe light source 74, for example, a xenon flash is used. A part of the strobe light emitted from the strobe light source 74 is reflected by the beam splitter 76 provided inside the housing 60, and is held by the chuck table 16 via the objective lens 66 and the light transmitting portion 64. The object 11 is irradiated.

On the optical axis of the objective lens 66, a camera 78 that captures an image of the workpiece 11 irradiated with strobe light is provided. For example, the camera 78 is configured by using a CCD (Charged-Coupled Devices) image sensor.

The strobe light source 74 and the camera 78 are connected to the control unit 80, and their operations are controlled by the control unit 80. Then, the control unit 80 synchronizes the irradiation of the strobe light from the strobe light source 74 with the imaging of the camera 78. As a result, the upper surface side of the workpiece 11 (chip 25) is imaged by the imaging unit 44, and an image of the workpiece 11 (chip 25) is acquired.

When the workpiece 11 is machined (see FIG. 4), foreign matter such as debris (cutting debris) generated by cutting may adhere to the workpiece 11. Therefore, when the image pickup unit 44 takes an image of the workpiece 11 following the division step, it is preferable to supply water from the water source 72 to the space 68 to wash away the foreign matter adhering to the workpiece 11. This makes it possible to prevent the imaging of the workpiece 11 from being hindered by foreign matter.

However, when the image pickup unit 44 images the work piece 11, it is not always necessary to supply water to the space 68. For example, if the step of cleaning the workpiece 11 (cleaning step) is separately performed after the workpiece 11 is divided and before the workpiece 11 is imaged, the workpiece 11 is imaged at the time of imaging. No foreign matter is attached to the work piece 11. In this case, the supply of water from the water source 72 to the space 68 can be omitted.

Further, the imaging of the workpiece 11 may be performed while the workpiece 11 and the imaging unit 44 are relatively moved. For example, while moving the chuck table 16 holding the workpiece 11 with respect to the image pickup unit 44, the irradiation of the strobe light from the strobe light source 74 and the image pickup by the camera 78 are synchronized, and the workpiece 11 is moved by the image pickup unit 44. Is imaged multiple times in succession. As a result, cutting of the workpiece 11 and imaging can be performed simultaneously.

The image (captured image) acquired by the imaging of the imaging unit 44 is output to the control unit 80 (see FIG. 1). Then, the control unit 80 detects the actual size of the chip 25 based on the captured image (detection step).

As shown in FIG. 1, the control unit 80 includes a detection unit 82 that detects the actual size of the chip 25. For example, the detection unit 82 measures the dimensions of the chip 25 by performing image processing such as edge detection and pattern matching on the captured image. Examples of the dimensions of the chip 25 to be measured include the size of the entire chip 25, the position of the electrode 19 included in the chip 25, and the like.

FIG. 5 shows an example of the dimensions of the chip 25 to be measured. L ₁ and L ₂ are values indicating the size of the entire chip 25. Specifically, L ₁ is the length of the chip 25 in the first direction indicated by the arrow A (longitudinal direction of the workpiece 11 and the left-right direction of the paper surface), and L ₂ is the _second length indicated by the arrow B. It is the length of the chip 25 in the direction (the lateral direction of the workpiece 11 and the vertical direction of the paper surface). The first direction and the second direction are perpendicular to each other. L ₁ and L ₂ correspond to the distances from one end to the other end of the chip 25, respectively.

Further, L ₃ and L ₄ are values indicating the position of the electrode 19 included in the chip 25 and the position of the calf 11b. Specifically, L ₃ is the distance from the calf 11b (outer peripheral edge of the chip 25) along the first direction (arrow A) to one electrode 19 arranged at the position closest to the calf 11b. .. Further, L ₄ is a distance from the calf 11b (outer peripheral edge of the chip 25) along the second direction (arrow B) to one electrode 19 arranged at the position closest to the calf 11b. In FIG. 5, L ₃ and L ₄ are set with reference to the four electrodes 19 formed at the positions closest to the four corners of the chip 25.

The detection unit 82 (see FIG. 1) detects L ₁ and L ₂ by, for example, performing edge detection processing on the captured image. Specifically, the detection unit 82 specifies the coordinates of the boundary between the chip 25 and the calf 11b (the outer peripheral edge of the chip 25, the end of the calf 11b) based on the shading of the captured image. Then, L ₁ and L ₂ are calculated from the difference between the coordinates of the two boundaries facing each other with the chip 25 in between.

Further, the detection unit 82 detects L ₃ and L ₄ by performing pattern matching processing on the captured image, for example. Specifically, an image (reference image) of the chip 25 on which the electrode 19 is represented is acquired in advance, and the captured image acquired by the imaging unit 44 is compared with the reference image. Then, based on the positional relationship between the chuck table 16 (workpiece 11) and the image pickup unit 44 when the position of the electrode 19 shown in the captured image and the position of the electrode 19 shown in the reference image match. , The coordinates of the electrode 19 are specified.

After that, the detection unit 82 calculates the difference between the coordinates of the outer peripheral edge of the chip 25 and the coordinates of the electrode 19. As a result, L ₃ and L ₄ are calculated. The detection method of L ₁ , L ₂ , L ₃ , and L ₄ is not limited, and the detection unit 82 may detect L ₁ , L ₂ , L ₃ , and L ₄ by using another method.

Further, the captured image acquired by the imaging unit 44 may be an entire image of the work piece 11 or a part of the work piece 11. In particular, the accuracy of detecting the actual size of the chip 25 can be improved by acquiring the enlarged image of the chip 25 by the imaging unit 44. Further, the vicinity of the four corners of one chip 25 may be individually imaged, and the actual size of the chip 25 may be detected based on the plurality of captured images obtained thereby.

Further, the control unit 80 may generate an entire image of the workpiece 11 by synthesizing a plurality of captured images representing a part of the workpiece 11. In this case, the detection unit 82 may detect the actual size of the chip 25 using the generated composite image. Further, the detection unit 82 may detect the actual dimensions of all the chips 25 obtained by dividing the workpiece 11, or may detect the actual dimensions of some of the chips 25.

The actual size of the chip 25 detected by the detection unit 82 can be displayed on, for example, the display unit 48 (see FIG. 1). In this case, the control unit 80 controls the display unit 48, and causes the display unit 48 to display the actual size of the chip 25. As a result, the operator of the cutting device 2 is notified of the actual size of the tip 25.

As described above, in the cutting device 2 according to the present embodiment, the control unit 80 detects the actual size of the chip 25. Therefore, the work of manually measuring the dimensions of the chip 25 by the evaluator of the chip 25 using a microscope or the like can be omitted, and the evaluation process of the chip 25 is simplified.

In addition to detecting the actual size of the chip 25, the control unit 80 may calculate a value (variation value) indicating the degree of variation in the actual size of the chip 25 (calculation step). Examples of the variation value include dispersion of actual dimensions, standard deviation of actual dimensions, process capability index (C _p , C _pk, etc.) and the like.

As shown in FIG. 1, the control unit 80 includes a calculation unit 84 that calculates a variation value of the actual size of the chip 25, and a storage unit 86 that stores a program used for processing by the calculation unit 84, various parameters, and the like. Be prepared. The storage unit 86 stores a program for calculating the actual size of the chip 25 detected by the detection unit 82, the reference value of the size of the chip 25, the variation value of the actual size of the chip 25, and the like. The reference value of the dimensions of the chip 25 is, for example, a standard value of the dimensions of the chip 25, and the permissible values (upper limit value and lower limit value) of the actual dimensions of the chip 25 are stored in the storage unit 86 as reference values.

Then, the calculation unit 84 calculates the variance and standard deviation of the actual size of the chip 25 based on the actual size of the chip 25 detected by the detection unit 82. Further, the calculation unit 84 calculates the process capability index (C _p , C _pk, etc.) of the chip 25 based on the actual size of the chip 25 and the reference values (upper limit value and lower limit value) stored in the storage unit 86. calculate.

When the calculation unit 84 sends out the variation value of the actual size of the chip 25, the control unit 80 displays the variation value on the display unit 48. As a result, the operator of the cutting device 2 is notified of the degree of variation in the actual size of the chip 25. At this time, the display unit 48 may display the reference value (upper limit value and lower limit value) of the actual size of the chip 25 together with the variation value.

As described above, in the cutting device 2 according to the present embodiment, the control unit 80 can also calculate the variation value of the actual size of the chip 25. As a result, the evaluator of the chip 25 can omit the work of calculating the variation value based on the actual size of the chip 25, and the evaluation process of the chip 25 is simplified.

In addition to the dimensions of the chip 25, the detection unit 82 may further detect the position of the calf 11b (see FIG. 5) formed on the workpiece 11. The position of the calf 11b is determined, for example, by performing predetermined image processing (edge detection, pattern matching, etc.) on the image acquired by the image pickup unit 44. By detecting the position of the calf 11b (for example, the coordinates of the center or the end in the width direction of the calf 11b) by the detection unit 82, it is possible to confirm whether or not the workpiece 11 is cut at a desired position. it can.

Further, the storage unit 86 may store information on the position of the workpiece 11 to be cut (ideal position of the calf 11b). In this case, the detection unit 82 may calculate the difference between the ideal position of the calf 11b and the detected position of the calf 11b, that is, the amount of deviation of the cutting region. This deviation amount is stored in the storage unit 86.

When the above deviation amount is stored in the storage unit 86, when the work piece 11 is subsequently cut by the cutting blade 42 (see FIG. 4), the work piece 11 and the cutting blade 42 cancel the deviation amount. It is possible to correct the positional relationship with. As a result, the workpiece 11 can be accurately cut by the cutting blade 42.

For example, the workpiece 11 may be warped in the manufacturing process. Specifically, when the heat treatment for curing the resin layer 15 (see FIG. 2B) is performed when the work piece 11 is manufactured, the resin layer 15 shrinks and the work piece 11 warps. May occur. When the workpiece 11 is warped, the position of the planned division line 17 (see FIG. 2A) changes. As a result, it becomes difficult for the workpiece 11 to be appropriately cut along the scheduled division line 17, and the calf 11b is likely to be misaligned.

Here, the degree of warpage of the workpiece 11 manufactured in the same lot (same process) tends to be substantially the same, and the degree of misalignment of the calf 11b tends to be substantially the same. Therefore, the misalignment of the calf 11b when one workpiece 11 is divided is detected, and when the other workpiece 11 manufactured in the same lot is divided, the cutting region is such that this misalignment is canceled. By correcting the position of, it becomes possible to cut another workpiece 11 along the ideal position of the calf 11b.

Specifically, first, one workpiece 11 is divided into a plurality of chips 25, and then an image is taken by the image pickup unit 44 to detect the position of the calf 11b. For example, the calf 11b formed in the center of FIG. 5 along the direction indicated by the arrow B is imaged. Then, the distance L ₄ (distance L _4a ) from one end of the calf 11b (the left end in FIG. 5) to the electrode 19 arranged at the position closest to one end of the calf 11b and the other end of the calf 11b (FIG. 5). In 5, the distance L ₄ (distance L _4b ) from the right end) to the electrode 19 arranged at the position closest to the other end of the calf 11b is detected.

Here, for example, consider the case where the ideal values of L _4a and L _4b are 0.4 mm, and the detected values of L _4a and L _4b are 0.3 mm and 0.5 mm, respectively. In this case, the amount of misalignment of the cutting region in the direction indicated by the arrow A (first direction) is 0.1 mm. Then, this misalignment amount is stored in the storage unit 86.

After that, when the other workpiece 11 manufactured in the same lot is divided, the position of the cutting region is the above-mentioned misalignment amount (0.1 mm) on the other end side (right side in FIG. 5) of the calf 11b. ) The cutting process is performed with the correction corrected. As a result, the influence of the change in the position of the scheduled division line 17 due to the warp of the workpiece 11 is canceled, and the workpiece 11 is appropriately cut.

In the above, the amount of misalignment of the cutting region when cutting one workpiece 11 and the amount of correction of the cutting region when cutting another workpiece 11 are the same (0.1 mm). Although the case has been described, both do not necessarily have to be the same. For example, a value (0.05 mm) corresponding to half of the amount of misalignment of the cutting region when cutting one workpiece 11 is set as the correction amount of the cutting region when cutting another workpiece 11. You can also do it.

As described above, the cutting apparatus 2 according to the present embodiment has an imaging unit 44 that images an image of the workpiece 11 divided into a plurality of chips 25, and the actual chip 25 based on the images of the chips 25 acquired by the imaging. A control unit 80 for detecting the dimensions is provided. As a result, the dimensions of the chip 25 can be automatically measured by the cutting device 2, and the detection of the dimensions of the chip 25 is simplified.

The details of the components of the cutting device 2 according to the present embodiment can be changed as appropriate. For example, instead of the chuck table 16 shown in FIG. 1, a jig table for holding the workpiece 11 can be used. For example, the jig table is formed in a rectangular shape in a plan view corresponding to the shape of the workpiece 11, and the upper surface of the jig table constitutes a holding surface for holding the workpiece 11.

Suction holes are provided in the regions of the holding surface side of the jig table corresponding to the device region 11a (see FIG. 2A) of the workpiece 11. The plurality of suction holes are connected to the suction source via a suction path formed inside the jig table. With the workpiece 11 placed on the holding surface of the jig table, the negative pressure of the suction source is applied to the lower surface of the workpiece 11 through the suction holes, so that the workpiece 11 is moved by the jig table. It is sucked and held.

Further, a linear groove (see FIG. 4) into which the lower end portion of the cutting blade 42 (see FIG. 4) is inserted in the region corresponding to the planned division line 17 (see FIG. 2 (A)) on the holding surface side of the jig table. An escape groove) is formed. When the workpiece 11 held by the jig table is cut by the cutting blade 42, the lower end portion of the cutting blade 42 passes through the inside of the groove. As a result, contact between the cutting blade 42 and the jig table is avoided.

After the workpiece 11 is divided into a plurality of chips 25, each of the chips 25 is held by the negative pressure of the suction source acting through the suction holes formed in the jig table. Therefore, the arrangement of the insert 25 is maintained even after the workpiece 11 is divided. When the workpiece 11 is held by the jig table, the tape 21 can be omitted from the workpiece 11.

In addition, the structure, method, etc. according to the above-described embodiment can be appropriately modified and implemented as long as they do not deviate from the scope of the object of the present invention.

11 Work piece 11a Device area 11b Calf (cut)
13 Base substrate 13a Front surface 13b Back surface 15 Resin layer (mold resin)
17 Scheduled line (street)
19 Electrode 21 Tape 23 Frame 23a Aperture 25 Chip (Package device)
2 Cutting device 4 Base 4a Opening 4b Opening 4c Opening 6 Cassette support 8 Cassette 10 X-axis moving mechanism 10a X-axis moving table 12 Dust-proof and drip-proof cover 14 Temporary placement mechanism 14a, 14b Guide rail 16 Chuck table (holding table, holding means)
16a Holding surface 18 Clamp 20 Support structure 22 Cutting unit (cutting means)
24 Moving mechanism 26 Y-axis guide rail 28 Y-axis moving plate 30 Y-axis ball screw 32 Y-axis pulse motor 34 Z-axis guide rail 36 Z-axis moving plate 38 Z-axis ball screw 40 Z-axis pulse motor 42 Cutting blade 44 Imaging unit (imaging means) )
46 Cleaning unit 48 Display (display means)
60 Housing 60a Lower end 60b Water supply port 62 Partition 64 Light transmission part 66 Objective lens 68 Space 70 Valve 72 Water source 74 Strobe light source 76 Beam splitter 78 Camera 80 Control unit (control means)
82 Detection unit 84 Calculation unit 86 Storage unit

Claims (9)

A holding means for holding a workpiece having electrodes in a plurality of regions partitioned by a plurality of scheduled division lines intersecting with each other.
A cutting means to which a cutting blade for cutting the workpiece held by the holding means is mounted, and
An imaging means for imaging the workpiece and
A method of dividing a work piece by dividing the work piece into a plurality of chips and detecting the actual size of the work piece by a cutting device including a holding means and a control means for controlling the cutting means. ,
A dividing step in which the workpiece is cut by the cutting blade along the planned division line and divided into a plurality of the chips.
An image acquisition step of capturing an image of the chip with the imaging means and acquiring an image of the chip.
A method for dividing a workpiece, which comprises a detection step of detecting the actual size of the chip by the control means based on the image. The method for dividing a workpiece according to claim 1, further comprising a calculation step of calculating a value indicating the degree of variation in the actual size of the chip by the control means. In the division step, the workpiece is divided while being held by the holding means.
The method for dividing a work piece according to claim 1 or 2, wherein in the image acquisition step, the work piece is imaged while being held by the holding means. A holding means for holding a workpiece having electrodes in a plurality of regions partitioned by a plurality of scheduled division lines intersecting with each other.
A cutting means to which a cutting blade for cutting the workpiece held by the holding means is mounted, and
An imaging means for imaging the workpiece and
A chip size detection method for detecting the actual size of a chip by dividing the workpiece into a plurality of chips with a cutting device including the holding means and a control means for controlling the cutting means.
A dividing step in which the workpiece is cut by the cutting blade along the planned division line and divided into a plurality of the chips.
An image acquisition step of capturing an image of the chip with the imaging means and acquiring an image of the chip.
A method for detecting the size of a chip, which comprises a detection step of detecting the actual size of the chip by the control means based on the image. The chip size detection method according to claim 4, further comprising a calculation step of calculating a value indicating the degree of variation in the actual size of the chip by the control means. In the division step, the workpiece is divided while being held by the holding means.
The method for detecting the size of a chip according to claim 4 or 5, wherein in the image acquisition step, the workpiece is imaged while being held by the holding means. A holding means for holding the work piece,
A cutting means to which a cutting blade for cutting the workpiece held by the holding means is mounted, and
An imaging means for imaging the workpiece and
A cutting device including a holding means and a control means for controlling the cutting means.
The imaging means captures an image of the workpiece divided into a plurality of chips by the cutting blade and acquires an image of the chips.
The control means is a cutting device including a detection unit that detects the actual size of the chip based on the image. The control means
A storage unit that stores preset reference values for the chip dimensions, and
The cutting apparatus according to claim 7, further comprising a calculation unit that calculates a value indicating the degree of variation in the actual size of the chip based on the actual size of the chip and the reference value. .. The cutting apparatus according to claim 8, further comprising a display means for displaying the value calculated by the calculation unit.