JP7323323B2 - splitter - Google Patents

Description

The present invention relates to a dividing apparatus for dividing a workpiece such as a semiconductor wafer into device chips along streets.

When dividing a workpiece such as a semiconductor wafer into device chips along a dividing line called a street, the workpiece is formed with a division starting point such as a modified layer or a groove-shaped cut end called a kerf. A tape is attached to and integrated with the ring frame, and the tape exposed at the opening of the ring frame is pushed up and expanded, for example, to divide the workpiece starting from the division starting point (see, for example, Patent Document 1). ), and the spacing between chips is widened.

JP 2015-095620 A

However, the amount of expansion may vary depending on the processing method for forming the division starting points in the workpiece. In addition, in the process of forming a kerf instead of a division starting point on the workpiece, the expansion amount is appropriately adjusted in order to improve the workability of the next process, such as picking up the chips, and to prevent the device chips from coming into contact with each other. Must be set. The amount of expansion in the tape expansion is determined by performing experiments in advance and observing, for example, the state in which the workpiece is processed in the experiments. Therefore, if there is an error in the expansion amount determined by the operator's observation, there is a problem that the device chips come into contact with each other during pickup, for example.

Therefore, when the tape is expanded to widen the gap between the device chips, there is a problem that the amount of expansion is set correctly so that the device chips do not come into contact with each other during pick-up or the like.

In order to solve the above-mentioned problems, the present invention is a work piece in which devices are formed in regions partitioned by streets and a ring frame having an opening capable of accommodating the work piece, and a dicing tape is attached to the ring frame so as to form an integrated body. a chuck table for holding a work set that has been processed; a dividing means for forming kerfs along the streets of the work piece held by the chuck table; imaging means for imaging the kerf formed on the workpiece, wherein the chuck table is made of a transparent member, and the upper surface and the suction source communicate with each other so that the upper surface functions as a holding surface. a transparent plate provided with a suction port that allows the suction to be performed, a base for supporting the transparent plate, and a lower illumination provided between the transparent plate and the base for illuminating the workpiece held on the holding surface from below . wherein the lower illumination is turned on and the imaging means images the upper surface of the workpiece divided by forming kerfs along the streets and the upper surface of the dicing tape on which the kerfs are formed to produce an image. The object is formed by combining a plurality of the captured images, which are composed of a white portion imaged white because the light of the lower illumination is transmitted and a black portion imaged black because the light of the lower illumination is blocked by the workpiece. an image storage unit for storing a combined image showing the top surface of a workpiece; The amount of expansion in the expansion of the dicing tape to widen the gap between the provided chips is the ideal total area of the kerf of the white portion of the combined image stored in the image storage unit after the expansion. and a calculating unit that calculates based on an increase in the total area of the kerf .

In the dividing device according to the present invention, the chuck table comprises a transparent plate which is made of a transparent member and has a suction port which communicates the upper surface with a suction source so that the upper surface functions as a holding surface; and a base which supports the transparent plate. and a lower illumination arranged between the transparent plate and the base to illuminate the holding surface, and when the lower illumination is turned on, the upper surface of the workpiece divided by forming kerfs along the streets is imaged by the imaging means. A photographed image is formed, and a plurality of photographed images composed of a white portion photographed white because the light of the lower illumination is transmitted and a black portion photographed black because the light of the lower illumination is blocked by the workpiece is combined. an image storage for storing a combined image showing the top surface of a workpiece; and a chip comprising a device kerfed and divided along streets by the number of pixels in the white portion of the combined image stored in the image storage. and a calculating unit for calculating an expansion amount for widening the gap between the chips, so that the expansion amount is correctly set by the splitting device itself, and the gap between the chips is widened to an appropriate gap. Therefore, chipping of the chips can be prevented by preventing the chips from coming into contact with each other when the chips are picked up by a bonding apparatus or the like to which the divided workpiece is conveyed.

It is a perspective view which shows an example of a dividing device. FIG. 10 is a cross-sectional view for explaining a state in which the lower illumination is turned on, the kerf of the workpiece is imaged by the imaging means, and a captured image is formed. FIG. 4 is an explanatory diagram showing an example of a captured image; FIG. 4 is an explanatory diagram showing an example of a combined image; FIG. 10 is an explanatory diagram for explaining an ideal image showing the surface of the workpiece after tape expansion; FIG. 4 is a cross-sectional view showing a state in which a work set is set on the expanding means; FIG. 4 is a cross-sectional view showing a state in which the dicing tape is expanded to increase the distance between chips;

A dividing device 1 according to the present invention shown in FIG. 1 is a device that irradiates a laser beam to a workpiece W held on a chuck table 30, for example, to perform processing (for example, ablation processing) to divide the workpiece. The dividing device 1 may be a cutting device that cuts the workpiece W with a rotating cutting blade to form kerfs along the streets S and divide the workpiece W. As shown in FIG.

The workpiece W shown in FIG. 1 is, for example, a semiconductor wafer having a circular outer shape and made of silicon as a base material. A device D such as an IC is formed in each area partitioned by the streets S in a grid pattern. The workpiece W may be made of gallium arsenide, sapphire, ceramics, resin, gallium nitride, silicon carbide, or the like, other than silicon.

The workpiece W is in a state where a dicing tape T having appropriate elasticity and having a larger diameter than the workpiece W is adhered to its rear surface Wb. Also, the outer peripheral portion of the dicing tape T is adhered to the ring frame F. As shown in FIG. As a result, the work piece W is integrated with the ring frame F via the dicing tape T, is accommodated in the circular opening of the ring frame F, and becomes a work set WS that can be handled by the ring frame F. there is

A Y-axis moving unit 20 is provided on the base 10 of the dividing device 1 to reciprocate the chuck table 30 in the Y-axis direction, which is the indexing feed direction. The Y-axis moving unit 20 includes a ball screw 200 having an axial center in the Y-axis direction, a pair of guide rails 201 arranged parallel to the ball screw 200, a motor 202 for rotating the ball screw 200, and a nut inside the ball screw. 200 and a movable plate 203 whose bottom portion is in sliding contact with the guide rail 201 . When the motor 202 rotates the ball screw 200 , the movable plate 203 is guided by the guide rails 201 and moves in the Y-axis direction. As the movable plate 203 moves, the chuck table 30 arranged in the direction of the Y-axis moves.

An X-axis movement unit 21 is provided on the movable plate 203 to reciprocate the chuck table 30 in the X-axis direction, which is the processing feed direction. The X-axis movement unit 21 includes a ball screw 210 having an axis in the X-axis direction, a pair of guide rails 211 arranged parallel to the ball screw 210, a motor 212 for rotating the ball screw 210, and a nut inside the ball screw. 210 and a movable plate 213 whose bottom is in sliding contact with the guide rail 211 . When the motor 212 rotates the ball screw 210, the movable plate 213 is guided by the guide rails 211 and moves in the X-axis direction. moves in the X-axis direction along with the movement of .

The chuck table 30 shown in FIGS. 1 and 2 for holding the work set WS has a circular outer shape in a plan view, is made of a transparent member, and communicates with the suction source 39 so that the upper surface functions as a holding surface 300a. At least a transparent plate 300 provided with a suction port 300b that allows the suction port 300, a base 301 that supports the transparent plate 300, and a lower lighting 302 that is arranged between the transparent plate 300 and the base 301 and illuminates the holding surface 300a. there is

The transparent plate 300 is made of a transparent material such as glass or acryl and formed into a circular plate shape in a plan view, and its flat upper surface serves as a holding surface 300a. The holding surface 300a has a plurality of suction ports 300b extending toward the inside of the transparent plate 300 in the −Z direction at equal intervals in the circumferential and radial directions. The plurality of suction ports 300b merge into one suction channel 300c inside the transparent plate 300, for example.
In addition, on the holding surface 300a, a plurality of annular suction grooves are formed concentrically around the rotation center of the chuck table 30, and the annular suction grooves are arranged evenly in the circumferential direction from the annular suction grooves. A connecting groove extending radially may be formed so as to connect the two, and a suction port 300b may be formed in the bottom of the suction groove or the connecting groove.

A base 301 that supports the transparent plate 300 is formed in a circular shape in a plan view. is a recess 301b in which the lower illumination 302 is accommodated.

The upper surface of the annular wall 301a is, for example, a stepped surface having a stepped surface, and the transparent plate 300 is fitted to the stepped surface. A predetermined space is provided between them.

The lower illumination 302 is arranged to face the transparent plate 300 in the Z-axis direction, and illuminates the workpiece W sucked and held on the holding surface 300a through the transparent plate 300 and the dicing tape T. be. The lower illumination 302 is composed of, for example, a plurality of LEDs (Light Emitting Diodes), but is not limited to this and may be a xenon lamp or the like. The lower illumination 302 emits light when power is supplied from a connected power source 302a, and irradiates light toward the upper holding surface 300a.

The lower end side of the suction channel 300c extending inside the transparent plate 300 passes through the inside of the base 301 and opens to the bottom surface of the base 301, for example. The suction channel 300c communicates with a suction source 39 such as an ejector mechanism or a vacuum generator via a metal pipe, a flexible resin tube, or the like.

For example, a cooling water passage 301d through which cooling water flows is formed inside the base 301, and the cooling water supply source 38 communicates with the cooling water passage 301d. The cooling water supply source 38 causes cooling water to flow into the cooling water passage 301d, and this cooling water circulates while cooling the base 301 from the inside. For example, the cooling water supplied from the cooling water supply source 38 can keep the temperature of the chuck table 30 at an appropriate temperature while the lower lighting 302 is generating heat by light irradiation.

As shown in FIG. 1, the chuck table 30 is rotatable by a rotating means 32 which is arranged on the bottom side and whose axial direction is the Z-axis direction (vertical direction). Around the chuck table 30, four fixing clamps 33 for fixing the ring frame F are evenly arranged in the circumferential direction.

On the front side (−Y direction side) of the dividing device 1, a cassette mounting table 191 is arranged on which a cassette 190 containing a plurality of work sets WS in a shelf shape is mounted. The cassette mounting table 191 is installed on a cassette elevator 192 that reciprocates in the Z-axis direction, and its height position is adjustable.

A centering guide 194 consisting of a pair of guide rails for aligning the work set WS pulled out from the cassette 190 at a fixed position is arranged behind the cassette mounting table 191 . Each guide rail having an L-shaped cross section and extending in the Y-axis direction can be separated from or approached to each other in the X-axis direction, and is arranged so that the stepped guide surfaces (inner surfaces) face each other. there is When the workpiece W is loaded onto the chuck table 30, the workpiece set WS is pulled out from the cassette 190 by the push-pull 193 shown in FIG. The processed and cleaned work set WS is placed on the centering guide 194 and then pushed into the cassette 190 by the push-pull 193 .
When the work set WS is placed, the pair of guide rails of the centering guide 194 approach each other and support the outer peripheral edge of the ring frame F to position (center) the work set WS with respect to the chuck table 30 .

A column 10A is erected behind the base 10 (on the +Y direction side), and a dividing means 60 is provided on the column 10A.
The dividing means 60 has, for example, a substantially rectangular parallelepiped casing 600 . The casing 600 horizontally extends in the -Y direction from the column 10A, and an irradiation head 609 is provided at the tip of the casing 600. As shown in FIG.

A laser oscillator 601 such as a YAG pulse laser is disposed in the casing 600, and the laser beam horizontally emitted from the laser oscillator 601 is reflected in the -Z direction by a mirror (not shown) and is reflected inside the irradiation head 609. , and the workpiece W held by the chuck table 30 is condensed and irradiated. The height position of the focal point of the laser beam can be adjusted in the Z-axis direction by a focal point position adjusting means (not shown).

At the tip of the casing 600, the imaging means 62 is arranged side by side with the irradiation head 609 in the X-axis direction.
The imaging means 62 includes, for example, a cylindrical housing 620 that blocks external light, and an optical system including an objective lens (not shown) into which the light emitted by the lower illumination 302 enters. and an imaging unit 621 that photoelectrically converts the light captured by the optical system and outputs it as image information. The imaging unit 621 is, for example, a two-dimensional array of a plurality of light receiving elements such as CCDs. Data transmitted by the amount of light received by each pixel of the light-receiving element of the imaging unit 621 is represented by, for example, 8-bit gradation of luminance value, that is, 256 patterns from 0 to 255. FIG.
Note that the imaging means 62 may be a line sensor camera or the like that is separated from the casing 600 and separately arranged above the movement path of the chuck table 30 .

For example, the dividing device 1 includes a conveying means 17 that conveys the machined work set WS from the chuck table 30 . The transport means 17 includes a transport pad 170 that holds the work set WS via the ring frame F, a transport pad moving means 171 that moves the transport pad 170 in the X-axis direction, and an elevating means 172 that moves the transport pad 170 up and down. equipped.

The transport pad 170 has, for example, an H-shaped outer shape in plan view, and the lower end side of the lifting means 172 is attached to the upper surface thereof. The transport pad 170 has four suction cups 170a for sucking the ring frame F on its lower surface. Each suction cup 170a communicates with a suction source (not shown) that generates a suction force.

The transfer pad moving means 171 is arranged, for example, on the front surface of the column 10A, and includes a ball screw 171a having an axis in the X-axis direction, a pair of guide rails 171b arranged in parallel with the ball screw 171a, and the ball screw 171a. and a movable block 171d which has a nut screwed onto the ball screw 171a and which supports the lifting means 172 inside. When the motor 171c rotates the ball screw 171a, the movable block 171d moves in the X-axis direction while being guided by the pair of guide rails 171b. move in the direction
The elevating means 172 is composed of an air cylinder, an electric cylinder, or the like, and elevates the transfer pad 170 in the Z-axis direction.

Cleaning means 18 is arranged under the moving path of the transport pad 170 . The cleaning means 18 is, for example, a single-wafer type spinner cleaning means. The workpiece W is sprayed and cleaned.

As shown in FIG. 1, the dividing device 1 comprises control means 9 for controlling the entire device. The control means 9 composed of CPU, ROM, etc. is electrically connected to, for example, the X-axis movement unit 21, the Y-axis movement unit 20, and the power source 302a for turning on and off the lower lighting 302. Under the control of , the machining feed operation of the chuck table 30 by the X-axis moving unit 21, the indexing and feeding operation of the chuck table 30 by the Y-axis moving unit 20, and the lighting operation of the lower lighting 302 by the power source 302a are appropriately performed. be.

The operation of each part of the dividing device 1 shown in FIG. 1 will be described below when the workpiece W is subjected to laser processing and divided into chips each having a device D. FIG.
The push-pull 193 shown in FIG. 1 pulls out one work set WS from the inside of the cassette 190 placed on the cassette placing table 191 , and the ring frame F is placed on the centering guide 194 . Then, the centering guide 194 centers the work set WS.

The centered work set WS is further transported and placed on the holding surface 300 a of the chuck table 30 from the centering guide 194 . The fixing clamp 33 clamps and fixes the ring frame F, and the suction force generated by the suction source 39 shown in FIG. The table 30 sucks and holds the workpiece W through the dicing tape T on the holding surface 300a. The center of the holding surface 300a of the chuck table 30 and the center of the workpiece W sucked and held substantially match.

Next, the position of the street S, which serves as a reference for forming a kerf by irradiating the workpiece W with the laser beam, is detected by alignment means (not shown) provided in the dividing device 1 . That is, for example, the streets S and the like on the surface Wa of the workpiece W are imaged by a camera, and the alignment means performs image processing such as pattern matching on the basis of the formed captured image. Detect coordinate position.

As the coordinate position of the street S is detected, the chuck table 30 moves in the Y-axis direction, and the street S and the irradiation head 609 of the dividing means 60 are aligned. This alignment is performed, for example, so that the center line of the street S is positioned directly below the focal point of the irradiation head 609 . Next, the position of the focal point of the laser beam condensed by the condenser lens 609a is adjusted to a predetermined height position of the workpiece W in the thickness direction.

Then, the laser oscillator 601 shown in FIG. 1 oscillates a laser beam having a wavelength that is absorptive to the workpiece W, and the laser beam is condensed and irradiated onto the workpiece W from the surface Wa side. Further, the workpiece W is fed in the -X direction, which is the forward direction, at a predetermined processing feed rate, and the workpiece W is ablated by irradiating the workpiece W with the laser beam along the streets S. A complete cut is made along the street S. That is, a linear groove-shaped kerf K shown in FIG.

When the workpiece W advances in the -X direction along one street S to a predetermined position where the irradiation of the laser beam is completed, the irradiation of the laser beam is stopped and the chuck table 30 shown in FIG. 1 is moved in the Y-axis direction. , and the irradiation head 609 are aligned in the Y-axis direction with the street S located adjacent to the street S used as a reference during laser beam irradiation in the processing feed in the -X direction. The workpiece W is fed in the +X direction, which is the backward direction, and the workpiece W is completely cut by irradiating the laser beam from the surface Wa side of the workpiece W in the same manner as the irradiation of the laser beam in the forward direction. Go (form kerf K).
If the workpiece W cannot be completely cut along one street S by irradiating one pass of the laser beam in the forward direction, a plurality of passes of the laser beam are radiated back and forth to the one street S. , forming a kerf K that completely cuts the workpiece W along the street S.

After irradiating similar laser beams sequentially along all the streets S extending in the X-axis direction, the chuck table 30 is rotated by 90 degrees, and then similar laser beams are irradiated. It can be divided into individual chips C (see FIG. 2) provided.

Next, while the chuck table 30 is fed in the X-axis direction and the Y-axis direction, the kerfs K are continuous from above the workpiece W divided by the kerfs K along the streets S by the imaging means 62 shown in FIG. It will be captured effectively. That is, for example, in a state in which the imaging means 62 is focused on the surface Wa of the workpiece W, the lower illumination 302 is turned on to emit illumination light (for example, visible light) upward. The illumination light passes through the transparent plate 300 and illuminates the workpiece W through the dicing tape T from the rear surface Wb side. Then, the light that has passed through the kerf K and escaped upward from the workpiece W is received by the light receiving element of the imaging unit 621 through an optical system (not shown), and the captured image shown in FIG. G1 and a plurality of captured images are sequentially formed.

The captured image G1 shown in FIG. 3 is, for example, an aggregate of 1 pixel (one pixel) of a predetermined size expressed in 8-bit gradation, that is, 256 ways from 0 to 255 for the luminance value. The brightness value of each pixel of the formed captured image G1 is determined by the amount of light incident on each pixel of the light receiving element of the imaging unit 621 . That is, the amount of light incident on the light-receiving element corresponding to the kerf K of the workpiece W shown in FIG. Incident light to the light-receiving element corresponding to the portion other than the portion is almost zero because it is blocked by the workpiece W, and the one pixel has a luminance value of 0 and approaches black.

The image capturing interval of the image capturing means 62 is determined by the size of the image capturing field of the image capturing means 62 and the like. It is preferable to be able to decide. The imaging of the entire surface Wa, which is the upper surface of the workpiece W, by the imaging means 62 may be performed, for example, in a spiral manner from the center of the workpiece W toward the outer peripheral side, or in a straight line. It may be done.

The imaging means 62 sequentially transmits a plurality of captured images including the captured image G1 showing the surface Wa of the workpiece W to the control means 9 shown in FIG. The plurality of pieces of image information are recorded in order in an image storage section 90 composed of a storage element or the like of the control means 9 so that a combined image showing, for example, the entire surface Wa of the workpiece W can be constructed.

When the imaging of the entire surface Wa of the workpiece W by the imaging means 62 is completed, for example, a plurality of captured images including the captured image G1 stored in the image storage unit 90 have a luminance value of one pixel of a predetermined value. A binarization process is performed in which a portion equal to or greater than a threshold value is rendered white, and a portion having a luminance value of one pixel less than a predetermined threshold value is rendered black. Note that the binarization process may not be performed.
A plurality of captured images including the captured image G1 after the binarization processing are combined and stored in the image storage unit 90 as a combined image GA showing the entire surface Wa of the workpiece W shown in FIG.

The transfer pad 170 shown in FIG. 1 carries out the workpiece W divided into chips C shown in FIG. Then, the cleaning means 18 cleans the workpiece W for a predetermined time.

For example, in the vicinity of the cleaning means 18, an expanding means 5 is arranged to widen the gap between the chips C shown in FIG. It is The position of the expanding means 5 is not limited to the example shown in FIG. The accommodated work set WS may be transported from the dividing device 1 to another expanding device.

For example, the work set WS cleaned by the cleaning means 18 is transported to the expanding means 5 by the transport means 17 .
The expanding means 5 shown specifically in FIG. formed. Four fixing clamps 52 (only two are shown in the illustrated example) are evenly arranged on the outer peripheral portion of the annular table 50 . The fixed clamp 52 is rotatable about a rotating shaft 52 c by a spring or the like, and sandwiches the ring frame F between the annular holding surface 50 a of the annular table 50 and the lower surface of the fixed clamp 52 . The annular table 50 can be moved up and down by, for example, an annular table elevating means 55 comprising an electric actuator. The annular table lifting means 55 may be composed of an air cylinder or the like.

A cylindrical expansion drum 53 is arranged in the opening 50c of the annular table 50 with its height position fixed, and the center of the annular table 50 and the center of the expansion drum 53 are substantially aligned. The outer diameter of the expansion drum 53 is, for example, larger than the diameter of the workpiece W divided into chips C. As shown in FIG.

In tape expansion, the ring frame F is placed on the holding surface 50a of the annular table 50 positioned at the reference height position. Next, the ring frame F is clamped and fixed between the fixing clamp 52 and the holding surface 50a of the annular table 50. As shown in FIG. In this state, the holding surface 50a of the annular table 50 and the annular upper end surface of the expansion drum 53 are at the same height position, and the upper end surface of the expansion drum 53 is aligned with the inner peripheral edge of the ring frame F of the dicing tape T. The lower surface side of the dicing tape T is brought into contact with the area between the outer peripheral edge of the workpiece W and the workpiece W. As shown in FIG.

Then, as shown in FIG. 7, the annular table lifting means 55 lowers the annular table 50 in the -Z direction at a predetermined pull-down speed (lowering speed of the annular table 50) and a predetermined amount of expansion. The holding surface 50 a of the table 50 is positioned at the tape extending position below the upper end surface of the extending drum 53 . As a result, the dicing tape T is pushed up by the upper end surface of the expansion drum 53 and expanded radially outward in the radial direction, and the gap between the chips C increases from the gap LA shown in FIG. 6 before expansion. be done.
The dicing tape T may be extended by fixing the annular table 50 and raising the extension drum 53 instead of lowering the annular table 50 .

For example, after widening the gap between the chips C by expanding the dicing tape T, the tension applied to the dicing tape T is increased by raising the annular table 50 in order to maintain the widened gap between the chips C. release. Then, the area where the slack is generated between the inner peripheral edge of the ring frame F of the dicing tape T and the outer peripheral edge of the workpiece W may be thermally shrunk by applying heat from a heater or the like that circulates above the area. .

As shown in FIG. 7, the annular table elevating means 55 lowers the annular table 50 in the -Z direction at a predetermined withdrawal speed and a predetermined amount of expansion, thereby increasing the distance between the chips C to a desired value. It can be the interval LB (see FIG. 7). Then, before performing the expansion, the dividing device 1 calculates and sets the predetermined expansion amount by itself, for example.

As shown in FIG. 1, the dividing device 1 picks up, for example, the chip C shown in FIG. A calculation unit 92 calculates an expansion amount of the dicing tape T for widening the gap LA between the chips C adjacent to each other to a desired gap LB. In this embodiment, the calculator 92 is incorporated in the control means 9 .

As described above, after the combined image GA shown in FIG. 4 is stored in the image storage section 90 shown in FIG. , it is displayed on a virtual output screen B (X-axis and Y-axis orthogonal coordinate plane) with a predetermined resolution. In the combined image GA displayed on the output screen B, the kerf K is displayed in white (white portion) in the image as a set of pixels having luminance values equal to or greater than a predetermined threshold. A region other than the kerf K on the surface Wa of the workpiece W is displayed in black (black portion) in the image as a set of pixels having luminance values less than a predetermined threshold.

For example, the amount of expansion can be defined by the value (%) of the surface area of the dicing tape T increased by the expansion, with the surface area of the dicing tape T before expansion being 100%.
In this case, for example, the calculator 92 calculates the total sum of pixels in the white portion in the combined image GA shown in FIG. That is, the calculator 92 calculates the total area S1 of the kerf K in the combined image GA.
For example, in the ROM (not shown) of the control means 9, appropriate expansion is applied in advance so that an appropriate space LB is formed between the chips C (for example, when picking up, the chips C and C An ideal image GD showing the surface Wa of the workpiece W in a state in which there is no contact with the workpiece W is stored. The ideal image GD is data obtained from past experiments or the like. Then, the calculation unit 92 grasps in advance the total area S2 of the kerf K, which is the sum of the pixels of the white portion in the ideal image GD.

The calculation unit 92 determines how much the total area S1 of the kerfs K in the combined image GA shown in FIG. , to calculate the amount of expansion. This is because the area of the dicing tape T to which the chip C is adhered is hardly expanded by the tape expansion. Therefore, in the dicing tape T before expansion, the area of the region corresponding to the kerf K to which the chip C is not attached (the total area S1 of the kerf K in the combined image GA shown in FIG. 4) is assumed to be 100%. The surface area value (%) of the increased area of the region corresponding to the kerf K of the dicing tape T (the total area S2 of the kerf K in the ideal image GD shown in FIG. 5) can be calculated by considering the expanded amount.

For example, when the calculator 92 calculates an appropriate amount of expansion, the lowering operation of the annular table lifting means 55 shown in FIG. 7 is performed under the control of the control means 9 as described above. Here, the amount of expansion has a correlation with the amount of pulling down of the annular table 50 in the -Z direction with respect to the fixed expansion drum 53 when expanding the dicing tape T (for example, several mm to several tens of mm). For example, the ROM (not shown) of the control means 9 stores a correlation table indicating the reduction amount of the annular table 50 corresponding to the calculated expansion amount. is selected from the correlation table, and the amount of pull-down by the annular table lifting means 55 is controlled. As a result, the dicing tape T is pushed up by the upper end surface of the expansion drum 53 and expanded radially outward in the calculated appropriate expansion amount, and the gap between the chips C is the desired gap. Expanded to LB.

After that, for example, transport means (not shown) carries out the work set WS from the expanding means 5 shown in FIG. 1 and places the work set WS on the centering guide 194 . Then, the work set WS centered by the centering guide 194 is carried into the cassette 190 by the push-pull 193 .

A plurality of chips C supported by the ring frame F via the dicing tape T, that is, the work set WS is conveyed to a bonding apparatus (not shown) in a cassette 190, for example. is the desired interval LB. can be prevented.

It goes without saying that the splitting device 1 according to the present invention is not limited to the above embodiment, and may be implemented in various forms within the scope of the technical idea. Moreover, the shape of each component of the dividing device 1 shown in the accompanying drawings is not limited to this, and can be changed as appropriate within the range in which the effects of the present invention can be exhibited.

For example, since the dividing device 1 itself stores in advance an appropriate expansion amount for each processed workpiece W, when the operator sets the expansion amount in the dividing device 1 in advance, the setting can be performed. Even if the calculated expansion amount is incorrect and insufficient, the splitting device 1 can calculate an appropriate expansion amount. Furthermore, when the expansion amount calculated by the calculation unit 92 is clearly significantly different from the conventional appropriate expansion amount, the operator is asked to confirm whether or not an abnormality has occurred in the dividing device 1. A signal or warning may be issued, thereby making it possible to detect an abnormality in the dividing device 1. FIG.

W: workpiece Wa: front surface of workpiece S: street D: device Wb: back surface of workpiece T: dicing tape F: ring frame WS: work set 1: dividing device 10: base 10A: column 190: Cassette 191: Cassette mounting table 192: Cassette elevator 193: Push-pull 194: Centering guide 20: Y-axis movement unit 21: X-axis movement unit
30: Chuck table 300: Transparent plate 300a: Holding surface 300b: Suction port 301: Base 301a: Annular wall 301b: Recess 302: Lower lighting 39: Suction source 38: Cooling water supply source 32: Rotating means 33: Fixing clamp 60 : Division Means 601: Laser Oscillator 609: Irradiation Head 609a: Condensing Lens 62: Imaging Means 620: Housing 621: Imaging Unit 17: Conveying Means 170: Conveying Pad 171: Conveying Pad Moving Means 172: Elevating Means 18: Washing Means
5: Expanding Means 50: Annular Table 50c: Opening 52: Fixed Clamp
55: Annular table lifting means 53: Expansion drum 9: Control means 90: Image storage unit 92: Calculation unit

Claims (1)

a chuck table for holding a work set formed by attaching a dicing tape to a work piece having devices formed in regions partitioned by streets and a ring frame having an opening capable of accommodating the work piece, and integrating the work set; dividing means for forming kerfs along the streets of the workpiece held on the chuck table; and imaging the kerfs formed on the workpiece from above the workpiece held on the chuck table. A dividing device comprising an imaging means,
The chuck table comprises a transparent plate made of a transparent member and having a suction port communicating between the upper surface and a suction source so that the upper surface functions as a holding surface, a base supporting the transparent plate, and the transparent plate. a lower illumination arranged between the base and illuminating the workpiece held on the holding surface from below ;
The lower illumination is turned on, and the upper surface of the workpiece on which kerfs are formed and divided along the streets by the imaging means and the upper surface of the dicing tape on which the kerfs are formed are picked up to form picked-up images. , an image for storing a combined image obtained by combining a plurality of captured images from a white portion imaged white due to transmission of the light of the under-illumination and a black portion imaged black due to the light of the under-illumination being blocked by a workpiece; a storage unit;
The amount of expansion in the expansion of the dicing tape, which is performed to widen the gap between the chip having the device divided by forming the kerf along the street, and the chip , is the amount of expansion of the combined image stored in the image storage unit. a calculating unit for calculating based on an increase when the total area of the kerf of the portion increases to the ideal total area of the kerf after the expansion.

Images