JP2018093042A - Wafer processing apparatus and wafer processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To confirm the presence or absence of chip skipping and a region where a wafer chip skipping occurs on a processing apparatus during or after processing. SOLUTION: A holding means 10 for holding a wafer W in which a plurality of planned division lines S are formed in a grid pattern on a surface Wa, and a wafer W held by the holding means 10 are divided along the scheduled division line S. The dividing means 11 and the imaging means 190 for imaging the wafer W are provided, and the image captured by the imaging means 190 of the wafer W divided by the dividing means 11 or the wafer W in the middle of division is acquired to determine the presence or absence of chip skipping. The wafer processing apparatus 1 is further provided with a detection unit for detecting a region where a chip jump of the wafer W has occurred. [Selection diagram] Fig. 1

Description

  The present invention relates to a processing apparatus that performs processing such as division on a wafer and a processing method that divides a wafer into chips, and more particularly, to a processing apparatus and a processing method that can detect the presence or absence of chip jumps associated with wafer division.

  A workpiece such as a semiconductor wafer formed by dividing a plurality of devices by a predetermined division line and formed on the surface is divided into individual device chips along the predetermined division line and used for various electronic devices.

  As a processing device used when dividing a wafer into chips, a cutting device (for example, refer to Patent Document 1) equipped with a cutting means on which a cutting blade to be cut into a wafer is rotatably mounted, and thinned with a grinding wheel that rotates the wafer. And a laser processing apparatus capable of performing ablation processing or the like on a wafer by irradiating a laser beam having a predetermined wavelength along a predetermined division line. Each of these processing apparatuses is provided with a holding table capable of sucking and holding the wafer.

JP 2000-307541 A

  When dust is placed on the holding surface of the holding table of the processing apparatus, when the wafer with the tape attached is stored under a fluorescent lamp for a long time, and the adhesive strength of the tape is weakened, or the wafer In the case where dust has entered between the wafer and the tape when the tape is attached to the wafer, chip jumping is likely to occur when the wafer held on the holding table is divided. Conventionally, chip skip detection is performed by taking a wafer out of a processing apparatus and observing the wafer divided into chips by visual observation with an operator's naked eye or using a microscope. It took a lot of time to grasp the area where the jump occurred.

  In addition, when a plurality of wafers are continuously processed with full auto in the processing equipment, the wafer divided into chips is automatically transferred to the die bonding equipment in the next process, etc. When picking up a chip, the presence or absence of chip skipping is found, so there is a problem that the processing device performs split processing one after another even though there is a defect during wafer split processing and chip skipping occurs. It was.

  Therefore, in a processing apparatus used to divide a wafer into chips, it is possible to confirm the presence or absence of chip jump and the area where the chip jump of the wafer has occurred on the processing apparatus during or after split processing. There are challenges.

  In order to solve the above problems, the present invention provides a holding means for holding a wafer having a plurality of division lines formed in a lattice shape on the surface, and the wafer held by the holding means along the division lines. A wafer processing apparatus comprising a dividing means for dividing and an image pickup means for picking up an image of a wafer, wherein an image obtained by picking up an image of the wafer divided by the dividing means or a wafer being divided by the image pickup means is obtained. The wafer processing apparatus further includes a detection unit that detects the presence / absence of a jump and a region where a wafer chip jump occurs.

  Further, the present invention for solving the above-described problem is a plurality of division schedules on the surface by a processing device including at least a holding unit that holds a wafer, a dividing unit that divides the wafer, and an imaging unit that images the wafer. A wafer processing method for dividing a wafer in which lines are formed in a lattice shape along the scheduled dividing line, a holding step for holding the wafer by the holding means, and a wafer held by the holding means. A division step for dividing along a planned division line, an imaging step for imaging a wafer during or after execution of the division step, and detection of presence / absence of chip skipping and a region where wafer chip skipping occurred from the captured image And a detecting step for performing a wafer processing method.

  The wafer processing apparatus according to the present invention obtains an image obtained by imaging the wafer divided by the dividing means or the wafer being divided by the imaging means, and detects the presence or absence of the chip jump and the area where the chip jump of the wafer occurs. Therefore, the presence / absence of chip jump and the area where the wafer chip jump occurs can be confirmed on the processing apparatus during or after the division process. Furthermore, for example, by analyzing data on the presence / absence of chip jump and the area where the wafer chip jump occurred, it is possible to detect defects in the processing apparatus at an early stage, and chip jumps occur due to defects in the processing apparatus. It is possible to prevent the wafer from being divided into chips one after another.

It is a perspective view which shows an example of a cutting apparatus. It is a perspective view which shows an example of the wafer divided | segmented into a chip | tip. It is explanatory drawing which shows the binarized image currently displayed on the output screen. 4A to 4D are explanatory views showing a state in which binarized images formed based on a total of four wafers divided into chips are displayed on the output screen. It is a perspective view which shows an example of a laser processing apparatus. It is a perspective view which shows an example of a grinding processing apparatus. It is a perspective view which shows the state by which a protective tape is stuck on the surface of a wafer, and also a dicing tape peels from a wafer.

(Embodiment 1)
A processing apparatus 1 shown in FIG. 1 is an apparatus that performs a cutting process on a wafer W (hereinafter referred to as a cutting apparatus 1), and a wafer W in which a plurality of division lines S are formed in a lattice shape on a surface Wa. Holding means 10 that holds the wafer W, a dividing means 11 that divides the wafer W held by the holding means 10 along the scheduled division line S (hereinafter referred to as cutting means 11), and an imaging means 190 that images the wafer W. At least.

  In front of the base 1 </ b> A of the cutting apparatus 1 (−Y direction side), a processing feed unit 12 that reciprocates the holding unit 10 in the X-axis direction is provided. The processing feed means 12 includes a ball screw 120 having an axis in the X-axis direction, a pair of guide rails 121 arranged in parallel to the ball screw 120, a motor 122 that rotates the ball screw 120, and an internal nut formed by the ball screw 120. And a movable plate 123 whose bottom portion is in sliding contact with the guide rail 121. When the motor 122 rotates the ball screw 120, the movable plate 123 is guided by the guide rail 121 and moves in the X-axis direction, and the holding means 10 disposed on the movable plate 123 moves the movable plate 123. Is moved in the X axis direction, the wafer W held by the holding means 10 is processed and fed.

  The holding unit 10 shown in FIG. 1 is, for example, a chuck table having a circular outer shape, and includes a suction unit 100 that sucks the wafer W and a frame body 101 that supports the suction unit 100. The suction unit 100 communicates with a suction source (not shown), and sucks and holds the wafer W on a holding surface 100 a that is an exposed surface of the suction unit 100. The holding means 10 is surrounded by a cover 102 from the periphery, and is driven and rotated by a rotating means 103 disposed on the bottom surface side of the holding means 10. In addition, around the frame body 101, four fixed clamps 104 for fixing the annular frame F are arranged evenly in the circumferential direction.

  On the base 1 </ b> A of the cutting apparatus 1, index feeding means 13 for reciprocating the cutting means 11 in the Y-axis direction is provided. The index feeding means 13 includes a ball screw 130 having an axis in the Y-axis direction, a pair of guide rails 131 arranged in parallel to the ball screw 130, a motor 132 for rotating the ball screw 130, and an internal nut formed by the ball screw 130. And a movable plate 133 whose bottom is in sliding contact with the guide rail 131. When the motor 132 rotates the ball screw 130, the movable plate 133 is guided by the guide rail 131 and moves in the Y-axis direction, and the cutting means 11 disposed on the movable plate 133 moves the movable plate 133. The cutting means 11 is indexed and moved by moving in the Y-axis direction along with the movement.

  A wall portion 145 stands integrally from above the movable plate 133, and a Z-axis direction moving means 14 for reciprocating the cutting means 11 in the Z-axis direction is provided on the side surface on the −X direction side of the wall portion 145. It has been. The Z-axis direction moving means 14 includes a ball screw 140 having an axis in the Z direction, a pair of guide rails 141 arranged in parallel to the ball screw 140, a motor 142 for rotating the ball screw 140, and an internal nut that is a ball screw. 140 and a holder 143 whose side part is in sliding contact with the guide rail 141. When the motor 142 rotates the ball screw 140, the holder 143 is guided by the guide rail 141 and moved in the Z-axis direction, and the cutting means 11 supported by the holder 143 via the housing 11A is the holder. With the movement of 143, it moves in the Z-axis direction.

  The cutting means 11 is attached to, for example, a distal end portion of a cylindrical housing 11A that is supported by a holder 143 and disposed horizontally with respect to the base 1A. The cutting means 11 includes, for example, a cutting blade 110 that cuts while rotating to the wafer W, a spindle 111 that rotatably supports the cutting blade 110 attached to the tip, a blade cover 112 that covers the cutting blade 110, and a cutting blade A cutting water supply nozzle 113 for supplying cutting water to 110.

  The cutting blade 110 shown in FIG. 1 is, for example, a hub blade, and includes an aluminum base that is formed in a disk shape and has a mounting hole in the center, and a cutting blade that is fixed to the outer periphery of the base. The cutting blade 110 is not limited to a hub blade, and may be a washer-type blade having an annular outer shape.

  The spindle 111 partially accommodated in the housing 11A has a direction (Y-axis direction) perpendicular to the horizontal direction with respect to the moving direction (X-axis direction) of the holding means 10, and is rotated by the housing 11A. Supported as possible. A motor (not shown) is connected to the rear end side (+ Y direction side end) of the spindle 111 accommodated in the housing 11 </ b> A, and the cutting blade 110 is attached to the front end of the spindle 111. As the spindle 111 is driven to rotate by a motor (not shown), the cutting blade 110 also rotates at a high speed.

  The blade cover 112 has an opening for attaching the cutting blade 110 at a substantially central portion thereof, and is attached to the housing 11A so that the cutting blade 110 is positioned in the opening and covers the cutting blade 110 from above. Can do.

  A cutting water supply nozzle 113 that supplies cutting water to a processing point where the cutting blade 110 contacts the wafer W is attached to the blade cover 112 so as to be movable up and down. For example, two cutting water supply nozzles 113 formed in an L shape when viewed from the Y-axis direction are disposed so as to sandwich the cutting blade 110 from both sides in the Y-axis direction, and are jetted toward the side surface of the cutting blade 110. A mouth is provided and communicates with a cutting water supply source (not shown).

  An alignment means 19 is disposed on the side surface of the front end of the housing 11A. The alignment unit 19 includes an imaging unit 190 that images the wafer W. The imaging unit 190 includes, for example, a light irradiation unit that irradiates light to the wafer W, an optical system that captures reflected light from the wafer W, and reflected light. And a camera composed of an image sensor (CCD) or the like that outputs an electrical signal corresponding to the above. The alignment unit 19 can detect the division line S based on the image acquired by the imaging unit 190. The alignment means 19 and the cutting means 11 are integrally configured, and both move in the Y-axis direction and the Z-axis direction in conjunction with each other.

  The cutting apparatus 1 includes a control means 9A configured by a storage element such as a CPU and a memory and controlling the entire apparatus. The control means 9A is connected to the machining feed means 12 and the alignment means 19 by wiring not shown, and under the control of the control means 9A, the machining feed of the holding means 10 in the X-axis direction by the machining feed means 12 is performed. In addition, the operation of detecting the division line S of the wafer W by the alignment means 19 is controlled.

  For example, the control unit 9A obtains an image obtained by imaging the wafer W divided by the cutting unit 11 or the wafer W in the middle of division by the imaging unit 190, and determines whether or not there is a chip jump and an area where the chip jump of the wafer W occurs. A detecting unit 90 for detecting, and a determining unit 91 for determining whether or not the amount of chip jump detected by the detecting unit 90 is within an allowable value.

  Below, the method of dividing | segmenting the wafer W using the said cutting apparatus 1 is demonstrated.

  The wafer W shown in FIG. 2 which is cut and divided into chips is, for example, a circular semiconductor wafer made of a silicon substrate, and the surface Wa of the wafer W has a lattice shape defined by the division lines S. A large number of devices D are formed in this area. A dicing tape T having a diameter larger than that of the wafer W is attached to the back surface Wb of the wafer W and is protected by the dicing tape T. An annular frame F having a circular opening is attached to the outer peripheral area of the adhesive surface of the dicing tape T, and the wafer W is supported by the annular frame F via the dicing tape T and handled via the annular frame F. Is in a possible state.

(1) Holding Step First, the wafer W is placed on the holding surface 100a with the dicing tape T side down so that the center of the holding means 10 and the center of the wafer W shown in FIG. . Then, the suction force generated by a suction source (not shown) is transmitted to the holding surface 100a, so that the wafer W is sucked and held by the holding means 10 with the surface Wa exposed upward. Further, the annular frame F is fixed by each fixing clamp 104.

(2) Dividing Step After the wafer W is held by the holding means 10, the processing feed means 12 shown in FIG. 1 sends the wafer W held by the holding means 10 in the −X direction to cut the cutting blade 110. The expected division line S is detected by the alignment means 19. That is, the alignment unit 19 performs image processing such as pattern matching based on the image of the planned division line S imaged by the imaging unit 190, and the coordinate position in the Y-axis direction of the planned division line S where the cutting blade 110 should be cut. Is detected. As the scheduled division line S is detected, the index feeding means 13 indicated by the cutting means 11 drives the Y-axis direction to align the scheduled division line S to be cut with the cutting blade 110 in the Y-axis direction. Done.

  After the alignment of the cutting blade 110 and the detected division line S in the Y-axis direction is performed, the holding means 10 that holds the wafer W is further fed in the −X direction at a predetermined cutting feed speed. The Z-axis direction moving means 14 lowers the cutting means 11 in the −Z direction. For example, the cutting means 11 is moved to a predetermined height position where the cutting blade 110 passes through the back surface Wb of the wafer W and reaches the dicing tape T. Is positioned.

  A motor (not shown) rotates the spindle 111 at a high speed, and the cutting blade 110 fixed to the spindle 111 cuts into the wafer W while rotating at a high speed with the rotation of the spindle 111 to cut the division planned line S. Further, the cutting water is sprayed from the cutting water supply nozzle 113 to the contact portion between the cutting blade 110 and the wafer W and the periphery thereof to cool and clean the processing point.

  When the wafer W advances in the -X direction to a predetermined position in the X-axis direction at which the cutting blade 110 finishes cutting the division line S, the cutting feed of the wafer W is once stopped by the processing feed means 12, and the Z-axis direction moving means 14 moves the cutting blade 110 away from the wafer W, and then the processing feeding means 12 sends the holding means 10 in the + X direction to return it to the original position. Then, by sequentially performing the same cutting while indexing and feeding the cutting blade 110 in the Y-axis direction at intervals of the adjacent division lines S, all the division lines S in the same direction are cut.

  Further, when the same cutting is performed after the holding means 10 is rotated 90 degrees by the rotation means 103, all the division lines S are fully cut vertically and horizontally, and the wafer W is divided into individual chips including the device D. The

(3) Imaging Step After performing the dividing step, an imaging step for imaging the wafer W with the imaging unit 190 is performed. In addition, you may perform this imaging step during implementation of the said division | segmentation step. In the imaging step, first, the wafer W is positioned below the imaging unit 190 by the processing feed unit 12 so that the entire wafer W is within the imaging area of the imaging unit 190. In this state, the light irradiation part of the imaging means 190 emits a predetermined amount of light. The light emitted from the light irradiation unit is applied to the surface Wa of the wafer W, and the reflected light from the wafer W forms an image on the image pickup device of the camera of the image pickup means 190, whereby the image pickup means 190 causes the surface of the wafer W to be reflected. A captured image is formed in which the entire Wa and the adhesive surface of the dicing tape T to which the wafer W is not attached are reflected.

(4) Detection Step The captured image showing the entire surface Wa of the wafer W formed by the imaging unit 190 is transferred to the detection unit 90 of the control unit 9A. The detection unit 90 binarizes the sent captured image at a predetermined slice level (threshold) to form a binarized image. That is, the detection unit 90 sets, for example, a captured image displayed with a luminance of 0 to 255 for one pixel as 0 for a pixel whose luminance value is lower than the slice level and as 255 for a pixel whose luminance value is higher than the slice level. , Converted into a binarized image G1.

  For example, the cutting apparatus 1 includes a monitor (not shown), and the detection unit 90 displays the binarized image G1 on an output screen B of a monitor with a resolution of 1600 × 1200, for example, as shown in FIG. . In the binarized image G1 displayed on the output screen B, the area where the adhesive surface of the dicing tape T below the wafer W is reflected, that is, the chip including the device D is flying away from the dicing tape T. The area is displayed as a white rectangle Ga of several pixels (for example, 9 pixels of 3 × 3) as pixels having a luminance value equal to or higher than the slice level. Further, an area corresponding to the division line S of the wafer W, that is, an area where the adhesive surface of the dicing tape T is shown in a line is a pixel having a luminance value equal to or higher than the slice level, and is a white line Gb in the image. Is displayed. Further, the chip including the device D in a state of being stuck on the dicing tape T is a pixel having a luminance value lower than the slice level, and is a black pixel of several pixels (for example, 9 pixels of 3 × 3) in the image. Displayed as a rectangle Gc. The dicing tape T around the wafer W is displayed with a white surface Gd in the image.

  Further, the detection unit 90 calculates the total sum of the pixels of each white rectangular Ga in the image as an integral value of the area of the area where the chip skip occurs. Then, the detection unit 90 transfers information about the calculated integral value of the area of the region where the chip jump has occurred to the determination unit 91. In advance, the determination unit 91 is set with an allowable chip jump amount (integral value of the area of the region where the chip jump occurs) of the wafer W divided into chips. The determination unit 91 compares the integrated value of the area of the region where the chip skip has been sent from the detection unit 90 with the allowable amount of chip skip, and determines whether or not the chip skip amount is within the allowable value. Determine whether.

  When the determination unit 91 determines that the amount of chip skip is within the allowable value, for example, when information indicating that the amount of chip skip is within the allowable value is transmitted from the determination unit 91 to the control unit 9A, the control is performed. Under the control of the means 9 </ b> A, a plurality of wafers W are continuously divided by the cutting apparatus 1.

  When the determination unit 91 determines that the amount of chip skipping exceeds the allowable value, for example, when information indicating that the amount of chip skipping exceeds the allowable value is transmitted from the determination unit 91 to the control unit 9. Under the control of the control means 9, for example, cutting of another wafer W is stopped. Alternatively, the determination unit 91 issues error information from a speaker or the like or displays error information on a monitor so that the operator can determine that the amount of chip skipping exceeds an allowable value.

  As described above, the wafer processing method according to the present invention includes the imaging step of imaging the wafer W during or after the division step, the presence / absence of chip skipping from the captured image, and the region where the wafer W chip skipping occurs. Therefore, a chip jump exceeding a permissible value is detected on the cutting device 1 during or after the split machining on the cutting apparatus 1 and the area where the chip jump of the wafer W occurs. This can be confirmed before the wafer W is continuously divided into a plurality of pieces in a situation where it can occur. The configuration of the cutting apparatus 1 according to the present invention is an optimal apparatus configuration for carrying out the wafer processing method according to the present invention.

  In the wafer processing method according to the present invention, for example, by analyzing data on the presence / absence of chip jump detected by the detection unit 90 and the area where the chip jump of the wafer W occurs, the chip jump exceeds an allowable value. A malfunction of the cutting apparatus 1 that causes the occurrence (for example, clogging of the holding surface 100a of the holding means 10 or adhesion of dust to the holding surface 100a) can be detected early. Specifically, first, as shown below, data on the presence / absence of a chip jump and the area where the chip jump of the wafer W occurs is collected.

  In the (4) detection step, for example, the detection unit 90 shown in FIG. 1 stores the formed binarized image G1 shown in FIG. 3 in the memory of the control means 9A. For example, in the present embodiment, the above (1) holding step to (4) detecting step are further performed on three wafers W, and the three wafers shown in FIGS. The binarized images G2 to G4 are formed, and the formed binarized images G2 to G4 are stored in the memory of the control means 9A. Note that the three wafers W to be divided may be dummy wafers. A binarized image G1 shown in FIG. 4A is the same image as the binarized image G1 shown in FIG.

Thus, after collecting data on the presence / absence of chip jump and the area where the chip jump of four wafers W occurred, for example, four binarized images G1 to G4 are displayed on a monitor (not shown). Areas inside the circular two-dot chain line L2 shown in FIGS. 4 (A) to 4 (D) are displayed side by side and the operator compares the four binarized images G1 to G4. It is possible to grasp that many chip jumps frequently occur inside. For example, the operator can find a defect in the holding surface 100a of the holding unit 10 by inspecting the region of the holding surface 100a of the holding unit 10 corresponding to the inner region of the two-dot chain line L2. Examples of the defects to be discovered include clogging of contamination such as cutting waste on the holding surface 100a made of a porous material. That is, it can be found that a lot of chip jumps have occurred because the suction force in the region of the holding surface 100a corresponding to the region inside the two-dot chain line L2 is weakened due to the clogging of the holding surface 100a.
In addition, for example, the detection unit 90 has a white rectangular Ga in the binarized image G1 to the binarized image G4 illustrated in FIGS. It is also possible to detect and record each X-axis and Y-axis coordinate position of the area that has been flying). As a recording method, for example, the detection unit 90 plots each X-axis Y-axis coordinate position of each white rectangle Ga in the binarized image G1 to the binarized image G4 on the X-axis Y-axis coordinate system. There is a method to create a separate plot. While creating such a plot diagram, by dividing the wafer W into a plurality of regions in the image, by recognizing a region having a large number of plotted coordinate positions of the white rectangle Ga among the divided regions, It becomes possible to grasp the region where the chip jump occurs on the wafer W more clearly and easily.

(Embodiment 2)
The processing apparatus 2 shown in FIG. 5 is a laser processing apparatus capable of performing ablation processing by irradiating a laser beam having a wavelength that absorbs the wafer W, for example, so that the wafer W can be fully cut (hereinafter, referred to as a laser processing apparatus). Let it be a laser processing apparatus 2). The laser processing apparatus 2 includes a holding unit 10 that holds the wafer W, a dividing unit 21 that divides the wafer W held by the holding unit 10 along a planned division line S (hereinafter referred to as a laser beam irradiation unit 21), and And at least imaging means 190 for imaging the wafer W.

  In front of the base 2A of the laser processing apparatus 2 (on the −Y direction side), a processing feed unit 12 that reciprocates the holding unit 10 in the X-axis direction is provided. The holding means 10 and the machining feed means 12 shown in FIG. 5 have the same configurations as the holding means 10 and the machining feed means 12 provided in the cutting apparatus 1 shown in FIG.

  In the laser processing apparatus 2, the holding unit 10 can be reciprocated in the X-axis direction by the processing feed unit 12, and the Y-axis direction moving unit 22 disposed below the holding unit 10 via the rotating unit 103. Thus, movement in the Y-axis direction is also possible. The Y-axis direction moving means 22 includes a ball screw 220 having an axis in the Y-axis direction, a pair of guide rails 221 arranged in parallel to the ball screw 220, a motor 222 that rotates the ball screw 220, and an internal nut. A movable plate 223 which is screwed into the ball screw 220 and whose bottom portion is in sliding contact with the guide rail 221 is configured. When the motor 222 rotates the ball screw 220, the movable plate 223 is guided by the guide rail 221 and moves in the Y-axis direction, and the holding means 10 disposed on the movable plate 223 moves the movable plate 223. Move in the Y axis direction.

  On the rear side (+ Y direction side) from the center on the base 2A of the laser processing apparatus 2, an index feeding means 13 for reciprocating the laser beam irradiation means 21 in the Y-axis direction is provided. The index feed means 13 shown in FIG. 5 has the same configuration as the index feed means 13 provided in the cutting apparatus 1 shown in FIG.

  A wall portion 145 is integrally provided on the movable plate 133 of the index feeding means 13, and the Z-axis direction reciprocally moves the laser beam irradiation means 21 on the side surface on the −X direction side of the wall portion 145 in the Z-axis direction. An axial movement means 14 is provided. The Z-axis direction moving means 14 has the same configuration as the Z-axis direction moving means 14 provided in the cutting apparatus 1 shown in FIG.

  The laser beam irradiation means 21 includes, for example, a cylindrical housing 210 that is supported by the holder 143 of the Z-axis direction movement means 14 and is disposed horizontally with respect to the base 2A. In the housing 210, for example, a laser beam oscillator 211 (for example, a YAG laser or a YVO4 laser) capable of oscillating a laser beam having a wavelength that absorbs the wafer W (for example, a wavelength near 355 nm) is disposed. A concentrator 212 for condensing the laser beam oscillated from the laser beam oscillator 211 is attached to the front end of the housing 210. The laser beam oscillator 211 and the concentrator 212 transmit optical fibers or the like. It is connected via an optical system. By reflecting a laser beam oscillated from the laser beam oscillator 211 in a substantially horizontal direction by a mirror (not shown) provided in the condenser 212 and entering the condenser lens 212a, the laser beam irradiation means 21 is The laser beam can be irradiated accurately while adjusting the position of a desired portion of the wafer W held by the holding means 10.

  An alignment unit 19 including an image capturing unit 190 that captures an image of the wafer W is disposed on the side surface of the front end of the housing 210. The alignment means 19 has the same configuration as that of the alignment means 19 provided in the cutting apparatus 1 shown in FIG. The alignment unit 19 and the laser beam irradiation unit 21 are integrally formed, and both move in the Y-axis direction and the Z-axis direction in conjunction with each other.

  The laser processing apparatus 2 includes a control unit 9B that includes a CPU and a storage element such as a memory and controls the entire apparatus. The control means 9B is connected to the machining feed means 12, the alignment means 19 and the like by wiring not shown, and under the control of the control means 9B, the machining feed of the holding means 10 in the X-axis direction by the machining feed means 12 is performed. In addition, the operation of detecting the division line of the wafer W by the alignment means 19 is controlled.

  For example, the control unit 9B obtains an image obtained by imaging the wafer W divided by the laser beam irradiation unit 21 or the wafer W in the middle of division by the imaging unit 190, and the presence or absence of the chip jump and the area where the chip jump of the wafer W occurs. And a determination unit 91 that determines whether or not the amount of chip skip detected by the detection unit 90 is within an allowable value.

  Hereinafter, a method of dividing the wafer W using the laser processing apparatus 2 will be described.

  The wafer W shown in FIG. 5 that is laser-processed and divided into chips is the same as the wafer W shown in FIG. 2, and the wafer W is supported by the annular frame F via the dicing tape T, and the annular frame F is Is ready for handling.

(1) Holding Step First, the wafer W is placed on the holding surface 100a with the dicing tape T side down so that the center of the holding means 10 and the center of the wafer W shown in FIG. . Then, the suction force generated by a suction source (not shown) is transmitted to the holding surface 100a, so that the wafer W is sucked and held by the holding means 10 with the surface Wa exposed upward. Further, the annular frame F is fixed by each fixing clamp 104.

(2) Dividing Step After the wafer W is held by the holding means 10, the processing feeding means 12 shown in FIG. 5 sends the wafer W held by the holding means 10 in the -X direction, and the laser beam is to be irradiated. The planned line S is detected by the alignment means 19. That is, the alignment unit 19 performs image processing such as pattern matching based on the image of the planned division line S imaged by the imaging unit 190, and the position of the planned division line S to be irradiated with the laser beam is detected.

  As the planned division line S is detected, the laser beam irradiation means 21 is driven in the Y-axis direction by the index feeding means 13, or the holding means 10 holding the wafer W by the Y-axis direction moving means 22 is Y By being driven in the axial direction, alignment in the Y-axis direction between the planned dividing line S for irradiating the laser beam and the condenser 212 is performed. This alignment is performed, for example, such that the center line of the planned division line S is located immediately below the condenser lens 212 a included in the condenser 212.

  The condensing point of the laser beam having an absorptivity with respect to the wafer W is positioned at a predetermined height position inside the wafer W corresponding to the division line S by the condenser 212. Then, while irradiating the wafer W from the surface Wa side of the wafer W along the division line S with the laser beam oscillated from the laser beam oscillator 211 and collected by the condenser lens 212a, the wafer W is irradiated in the −X direction. Are fed at a predetermined feed rate. By doing so, laser processing grooves are formed along the planned division line S by ablation processing. Then, a laser processing groove is formed to a depth reaching the dicing tape T by irradiating the same division scheduled line S multiple times while the holding means 10 is reciprocatingly moved in the X-axis direction by the processing feed means 12. To completely cut the wafer W.

  For example, after full cutting of one division planned line S with a laser beam, the laser beam irradiation from the laser beam oscillator 211 is temporarily stopped and the laser beam irradiation means 21 is moved in the Y-axis direction so that the laser full The concentrator 212 is aligned with the planned dividing line S that is positioned next to the cut planned dividing line S and not yet irradiated with the laser beam. Next, the processing feed means 12 processes and feeds the wafer W in the X-axis direction, and the laser beam is irradiated on the division planned line S in the same manner as the previous laser beam irradiation. By sequentially irradiating the same laser beam, the laser beam is irradiated along all the division lines S extending in the X-axis direction, and the wafer W is completely cut along the division lines S. Further, when the same laser beam irradiation is performed after the holding means 10 is rotated 90 degrees, the wafer W is completely cut along all the planned division lines S in the vertical and horizontal directions, and the wafer W is applied to each chip including the device D. Divided.

(3) Imaging Step After performing the dividing step, an imaging step for imaging the wafer W with the imaging unit 190 is performed. In addition, you may perform this imaging step during implementation of the said division | segmentation step. In the imaging step, first, the wafer W is positioned below the imaging unit 190 by the processing feed unit 12 so that the entire wafer W is within the imaging area of the imaging unit 190. In this state, the light irradiation part of the imaging means 190 emits a predetermined amount of light. The light emitted from the light irradiation unit is applied to the surface Wa of the wafer W, and the reflected light from the wafer W forms an image on the image pickup device of the camera of the image pickup means 190, whereby the image pickup means 190 causes the surface of the wafer W to be reflected. A captured image is formed in which the entire Wa and the adhesive surface of the dicing tape T to which the wafer W is not attached are reflected.

(4) Detection Step The captured image showing the entire surface Wa of the wafer W formed by the imaging unit 190 is transferred to the detection unit 90 of the control unit 9B. The detection unit 90 binarizes the sent captured image at a predetermined slice level (threshold) to form a binarized image. The detection unit 90 displays the formed binarized image G1 on an output screen B having a resolution of 1600 × 1200 as shown in FIG.

  Further, the detection unit 90 calculates the total sum of the pixels of each white rectangular Ga in the image as an integral value of the area of the region where the chip jump occurs, and transfers the information to the determination unit 91. The determination unit 91 compares the integrated value of the area of the region where the chip skip has been sent from the detection unit 90 with the preset allowable chip skip amount, and the chip skip amount is within the allowable value. It is determined whether or not.

  For example, when the determination unit 91 determines that the chip jump amount is within the allowable value, and information indicating that the chip skip amount is within the allowable value is transmitted from the determination unit 91 to the control unit 9B, the control is performed. Under the control of the means 9B, a plurality of wafers W are successively divided by the laser processing apparatus 2.

  For example, when the determination unit 91 determines that the amount of chip skipping exceeds the allowable value, and information indicating that the amount of chip skipping exceeds the allowable value is transmitted from the determination unit 91 to the control unit 9B. Under the control of the control means 9B, for example, the division processing of another wafer W is stopped. Alternatively, the determination unit 91 issues error information from a speaker or the like or displays error information on a monitor so that the operator can determine that the amount of chip skipping exceeds an allowable value.

  As described above, the wafer processing method according to the present invention includes the imaging step of imaging the wafer W during or after the division step, the presence / absence of chip skipping from the captured image, and the region where the wafer W chip skipping occurs. Detection step for detecting, and the presence or absence of chip skipping on the laser processing apparatus 2 and the area where the chip skipping of the wafer W occurs on the laser processing apparatus 2 during or after the split processing. This can be confirmed before the wafer W is continuously divided into a plurality of pieces in a situation where it can occur. The configuration of the laser processing apparatus 2 according to the present invention is an optimal apparatus configuration for carrying out the wafer processing method according to the present invention.

(Embodiment 3)
A processing apparatus 3 shown in FIG. 6 is an apparatus that performs grinding on the wafer W (hereinafter, referred to as a grinding apparatus 3), and the wafer W in which a plurality of division lines S are formed in a lattice shape on the surface Wa. Holding means 30 for holding the wafer W, a dividing means 32 for dividing the wafer W held by the holding means 30 along the scheduled division line S (hereinafter referred to as finish grinding means 32), and an imaging means 39 for imaging the wafer W. And at least.

  The front (−Y direction side) on the base 3A of the grinding apparatus 3 shown in FIG. 6 is an attachment / detachment area that is an area where the wafer W is attached to and detached from the holding unit 30 by the robot 330 that can transport the wafer W. The rear side (+ Y direction side) on the base 3A is held on the holding means 30 by the rough grinding means 31 that performs rough grinding on the wafer W or the finish grinding means 32 that performs finish grinding on the wafer W. This is a grinding area where the wafer W is ground.

  On the front side of the base 3A, a first cassette 331 that accommodates a wafer W before grinding and a second cassette 332 that accommodates a ground wafer W are disposed. In the vicinity of the first cassette 331 and the second cassette 332, a robot having a function of unloading the wafer W before grinding from the first cassette 331 and loading the ground wafer W into the second cassette 332 330 is disposed.

  The robot 330 has a configuration in which a holding portion 330b that holds the wafer W is provided at the tip of a bendable arm portion 330a, and the unprocessed wafer W is placed at a predetermined position in the movable range of the holding portion 330b. Positioning means 333 for positioning and cleaning means 334 for cleaning the ground wafer W are provided. The cleaning unit 334 is, for example, a single-wafer type spinner cleaning device, and includes a holding table 334 a that sucks and holds the ground wafer W.

  A first transport unit 335 is disposed in the vicinity of the alignment unit 333, and a second transport unit 336 is disposed in the vicinity of the cleaning unit 334. The first transport unit 335 has a function of transporting the pre-grinding wafer W placed on the alignment unit 333 to any one of the holding units 30 shown in FIG. It has a function of conveying the ground wafer W held by the holding means 30 to the cleaning means 334.

  For example, an arm turning means 39a connected to the arm 39b shown in FIG. 6 for turning the arm 39b in the horizontal direction is disposed between the first carrying means 335 and the second carrying means 336. An imaging means 39 is fixed to the tip of 39b. Then, the imaging means 39 can be positioned above the holding means 30 in a state where it has moved to the vicinity of the second transport means 336 by pivoting the arm 39b in the horizontal direction. The imaging means 39 is composed of, for example, a light irradiating unit that irradiates light to the wafer W, an optical system that captures reflected light from the wafer W, and an imaging device (CCD) that outputs an electrical signal corresponding to the reflected light. And a camera. The arrangement position of the imaging means 39 is not limited to this embodiment.

  A turntable 34 is disposed on the rear side (+ Y direction side) of the first conveying means 335 on the base 3A. For example, three holding means 30 are provided on the upper surface of the turntable 34 in the circumferential direction or the like. They are arranged at intervals. A rotation shaft (not shown) for rotating the turntable 34 is provided at the center of the turntable 34, and the turntable 34 can be rotated about the rotation shaft. The three holding means 30 are supported by the turntable 34 so as to be able to rotate and revolve. By the rotation of the turntable 34, any one of the holding means 30 is in the vicinity of the first conveying means 335 and the second conveying means 336. It is configured to be positioned.

  The holding unit 30 is, for example, a chuck table having a circular outer shape, and includes a suction unit 300 that is made of a porous member or the like and sucks the wafer W, and a frame body 301 that supports the suction unit 300. The suction unit 300 communicates with a suction source (not shown), and the suction force generated by the suction of the suction source is transmitted to the holding surface 300a that is the exposed surface of the suction unit 300. The wafer W is sucked and held on 300a.

  At positions adjacent to the rough grinding means 31 and the finish grinding means 32 on the base 3A, for example, a pair of height gauges 38A and a pair of height gauges 38B for measuring the thickness of the wafer W by a contact method are disposed. . Since the pair of height gauges 38A and the pair of height gauges 38B have the same structure, only the pair of height gauges 38A will be described below. The pair of height gauges 38A includes a first height gauge 381 for measuring the height position of the holding surface 300a of the holding means 30 and a second height gauge 382 for measuring the height position of the surface to be ground of the wafer W. The first height gauge 381 and the second height gauge 382 are each provided with a contact that moves up and down in the vertical direction. The first height gauge 381 detects the height position of the upper surface of the frame 301 serving as a reference surface, and the second height gauge 382 detects the height position of the surface to be ground of the wafer W to be ground. By calculating the difference between the detection values, the thickness of the wafer W can be measured at any time during grinding.

  A column 3B and a column 3C are erected side by side on the rear side (+ Y direction side) on the base 3A. A rough grinding unit 31 is held by a holding unit 30 on a side surface of the column 3B on the −Y direction side. The first grinding feed means 35 for grinding and feeding to the wafer W is disposed, and the finish grinding means 32 is provided on the wafer W held by the holding means 30 on the side surface on the −Y direction side of the column 3C. A second grinding feed means 36 for grinding and feeding is provided.

  The first grinding feed means 35 includes a ball screw 350 having a vertical axis, a pair of guide rails 351 disposed parallel to the ball screw 350, and a motor 352 connected to the ball screw 350 and rotating the ball screw 350. The inner nut is screwed to the ball screw 350 and the side portion is composed of an elevating unit 353 that is in sliding contact with the guide rail 351. The elevating unit 353 is guided by the guide rail 351 as the motor 352 rotates the ball screw 350. It is configured to move up and down. The lifting / lowering unit 353 supports the rough grinding unit 31, and the rough grinding unit 31 is also lifted / lowered by the lifting / lowering unit 353.

  The second grinding feed means 36 includes a ball screw 360 having a vertical axis, a pair of guide rails 361 disposed in parallel to the ball screw 360, a motor 362 connected to the ball screw 360 and rotating the ball screw 360. The inner nut is screwed into the ball screw 360 and the side portion is slidably in contact with the guide rail 361. The elevating portion (not shown) is attached to the guide rail 361 as the motor 362 rotates the ball screw 360. It is structured to be guided up and down. A lift unit (not shown) supports the finish grinding means 32, and the finish grinding means 32 also moves up and down as the lift part moves up and down.

  The rough grinding means 31 includes a rotating shaft 310 whose axial direction is the vertical direction (Z-axis direction), a spindle housing 311 that rotatably supports the rotating shaft 310, a motor 312 that rotationally drives the rotating shaft 310, and a rotating shaft. And a grinding wheel 313 detachably connected to the lower end of 310.

  On the bottom surface of the grinding wheel 313, a plurality of rough grinding wheels 313a having a substantially rectangular parallelepiped shape are annularly arranged. The rough grinding wheel 313a is formed, for example, with diamond abrasive grains fixed by a resin bond or a metal bond. In addition, the shape of the rough grinding wheel 313a may be integrally formed in an annular shape. The rough grinding wheel 313a is, for example, a grindstone used for rough grinding, and is a grindstone in which abrasive grains contained in the grindstone are relatively large.

  For example, a flow path (not shown) that communicates with the grinding water supply source and serves as a path for grinding water is formed in the rotating shaft 310 so as to penetrate in the axial direction of the rotating shaft 310 (Z-axis direction). The path is open at the bottom of the grinding wheel 313 so that grinding water can be ejected toward the rough grinding wheel 313a.

  The finish grinding means 32 can perform finish grinding for improving the flatness of the surface to be ground of the wafer W with respect to the wafer W thinned to about the finish thickness by rough grinding. That is, the finish grinding means 32 further grinds the wafer W ground by the rough grinding means 31 with the finish grinding wheel 323a that is rotatably mounted. The abrasive grains contained in the finish grinding stone 323a are abrasive grains having a smaller particle diameter than the abrasive grains contained in the coarse grinding wheel 313a of the coarse grinding means 31. The configuration of the finish grinding means 32 other than the finish grinding wheel 323 a is the same as that of the rough grinding means 31.

  The grinding apparatus 3 includes a control unit 9C that includes a CPU and a memory element such as a memory and controls the entire apparatus. The control means 9C is connected to the turntable 34, the first grinding feed means 35 and the like by wiring not shown, and under the control of the control means 9C, the holding means 30 is moved to a desired position by the turntable 34. The positioning operation and the grinding feed operation of the rough grinding means 31 by the first grinding feed means 35 are controlled.

  For example, the control unit 9C acquires an image obtained by imaging the wafer W divided by the finish grinding unit 32 or the wafer W in the middle of division by the imaging unit 190, and the presence or absence of the chip jump and the area where the chip jump of the wafer W occurs. And a determination unit 91 that determines whether or not the amount of chip jump detected by the detection unit 90 is within an allowable value.

  Hereinafter, a method for dividing the wafer W shown in FIG. 2 using the grinding apparatus 3 will be described. Before the wafer W is divided by the grinding apparatus 3, for example, the cutting apparatus 1 shown in FIG. 1 performs cutting on the surface Wa of the wafer W on which the device D is formed to form a half-cut groove. .

  Formation of the half-cut groove on the wafer W is first performed in a state where the wafer W is sucked and held by the holding means 10 with the surface Wa exposed upward. Further, the annular frame F is fixed by each fixing clamp 104.

  Next, the processing feeding means 12 shown in FIG. 1 sends the wafer W held by the holding means 10 in the −X direction, and the planned dividing line S where the cutting blade 110 should be cut is detected by the alignment means 19. As the planned division line S is detected, the cutting means 11 is driven in the Y-axis direction, and the planned division line S to be cut and the cutting blade 110 are aligned in the Y-axis direction. Then, the holding means 10 that holds the wafer W is further fed in the −X direction at a predetermined cutting feed speed. Further, the Z-axis direction moving means 14 lowers the cutting means 11 in the −Z direction, and the cutting means 11 is positioned at a predetermined height position at which the cutting blade 110 does not completely cut the wafer W. The predetermined height position is a position where the distance from the surface Wa of the wafer W to the bottom of the half cut groove formed by cutting is equal to or greater than the finished thickness of the wafer W.

  The cutting blade 110 cuts into the wafer W while rotating at a high speed, and the dividing line S is cut. Further, the cutting water is sprayed from the cutting water supply nozzle 113 to the contact portion between the cutting blade 110 and the wafer W and the periphery thereof to cool and clean the processing point. Then, by sequentially performing the same cutting while indexing and feeding the cutting blade 110 in the Y-axis direction at intervals of the adjacent division lines S, all the division lines S in the same direction are cut. Further, when the same cutting is performed after the holding means 10 is rotated by 90 degrees, all the division lines S are cut vertically and horizontally, and a half-cut groove having a predetermined depth is formed on the surface Wa of the wafer W. .

  The wafer W in which the half-cut groove M shown in FIG. 7 is formed is conveyed, for example, to a tape mounter (not shown), and the protective tape TA shown in FIG. The surface Wa is protected by the protective tape TA. Further, the dicing tape T is peeled off from the back surface Wb of the wafer W, and the support of the wafer W by the annular frame F is released. The wafer W to which the protective tape TA is adhered is accommodated in, for example, the first cassette 331 shown in FIG. 6 capable of accommodating a plurality of wafers W, and the wafer W to which the protective tape TA is adhered is plural. The first cassette 331 that contains the sheets is conveyed to the grinding apparatus 3.

(1) Holding step First, by rotating the turntable 34 counterclockwise as viewed from the + Z-axis direction, the holding means 30 in a state where the wafer is not placed revolves, and the holding means 30 becomes the first It moves to the vicinity of the conveying means 335. The robot 330 pulls out one wafer W from the first cassette 331 and moves the wafer W to the alignment means 333. Next, after the wafer W is positioned at a predetermined position in the alignment unit 333, the first transport unit 335 moves the wafer W on the alignment unit 333 to the holding unit 30. Then, the wafer W is placed on the holding surface 300a so that the center of the holding means 30 and the center of the wafer W substantially coincide with each other, and the holding means 30 sucks and holds the wafer W.

(2) Division step For example, when the turntable 34 rotates in the counterclockwise direction when viewed from the + Z-axis direction, the holding means 30 holding the wafer W revolves and reaches the bottom of the rough grinding means 31 in the grinding region. By moving, the grinding wheel 313 provided in the rough grinding means 31 and the wafer W held by the holding means 30 are aligned. The alignment is performed, for example, so that the rotation center of the grinding wheel 313 is shifted in the + Y direction by a predetermined distance with respect to the rotation center of the holding unit 30, and the rotation trajectory of the rough grinding wheel 313 a passes through the rotation center of the holding unit 30. Is called.

  After the grinding wheel 313 provided in the rough grinding means 31 and the wafer W are aligned, the grinding wheel 313 rotates as the rotary shaft 310 is driven to rotate. Further, the rough grinding means 31 is sent in the −Z direction by the first grinding feed means 35, and the rough grinding wheel 313 a of the rotating grinding wheel 313 comes into contact with the back surface Wb of the wafer W to perform rough grinding. . During the rough grinding, the wafer W held on the holding surface 300a also rotates as the holding means 30 rotates, so that the rough grinding wheel 313a performs rough grinding on the entire back surface Wb of the wafer W. Further, the grinding water is supplied to the contact portion between the rough grinding wheel 313a and the wafer W through the flow path inside the rotating shaft 310, and the contact portion between the rough grinding wheel 313a and the back surface Wb of the wafer W is cooled and cleaned. .

  During the rough grinding process, the thickness of the wafer W is measured at any time by the pair of height gauges 38A. When the wafer W is roughly ground by a predetermined grinding amount, the rough grinding of one wafer W is completed. Then, the wafer W that has been ground until it is formed to have a thickness before the finish thickness by rough grinding is ground until it is formed to a finish thickness by finish grinding. When the turntable 34 shown in FIG. 6 rotates counterclockwise as viewed from the + Z direction, the holding means 30 that holds the wafer W after rough grinding revolves, and the holding means 30 reaches the position below the finish grinding means 32. Moving. After the grinding wheel 313 provided in the finish grinding means 32 and the wafer W are aligned, the finish grinding means 32 is sent in the -Z direction by the second grinding feed means 36 to finish the rotating grinding wheel 313. The grinding wheel 323a is brought into contact with the back surface Wb of the wafer W to perform finish grinding. During finish grinding, as the holding means 30 rotates, the wafer W held on the holding surface 300a also rotates, so that the finish grinding wheel 323a performs finish grinding on the entire back surface Wb of the wafer W. Further, the grinding water is supplied to the contact portion between the finish grinding wheel 323a and the wafer W through the flow path inside the rotary shaft 310, and the contact portion between the finish grinding wheel 323a and the back surface Wb of the wafer W is cooled and washed. .

  During finish grinding, the thickness of the wafer W is measured at any time by a pair of height gauges 38B. When the wafer W is ground to the finish thickness while the flatness of the back surface Wb of the wafer W is improved, the finish grinding is completed. To do. The half-cut groove M formed in the wafer W is formed with a finished thickness because the distance from the surface Wa of the wafer W to the bottom of the half-cut groove M is equal to or greater than the finished thickness of the wafer W. By being ground until it is done, the half-cut groove M is exposed to the back surface Wb side and is divided into chips each including the device D.

(3) Imaging Step After performing the dividing step, an imaging step for imaging the wafer W with the imaging means 39 is performed. In addition, you may perform this imaging step during implementation of the said division | segmentation step. When the turntable 34 shown in FIG. 6 rotates counterclockwise as viewed from the + Z direction, the holding means 30 for holding the wafer W after finish grinding revolves, and the holding means 30 serves as the second conveying means 336. Move to the vicinity. Further, the imaging means 39 is positioned above the wafer W so that the arm 39b is pivotally driven so that the entire wafer W falls within the imaging area of the imaging means 39. In this state, the light irradiation part of the imaging means 39 emits a predetermined amount of light. The light emitted from the light irradiation unit is applied to the back surface Wb, which is the surface to be ground of the wafer W, and the reflected light from the wafer W forms an image on the image pickup device of the camera of the image pickup means 39, whereby the image pickup means 39. A captured image showing the entire back surface Wb of the wafer W is formed.

(4) Detection Step The captured image showing the entire surface Wa of the wafer W formed by the imaging unit 190 is transferred to the detection unit 90 of the control unit 9C. The detection unit 90 binarizes the sent captured image at a predetermined slice level (threshold) to form a binarized image. The detection unit 90 displays the formed binarized image G1 on an output screen B having a resolution of 1600 × 1200 as shown in FIG. In the third embodiment, the white rectangular Ga in the image is an area where the device D has been moved away from the protective tape TA, and the white line Gb in the image is the adhesive surface of the protective tape TA. This is a linear area, and the white surface Gd in the image is the upper surface of the frame 301 of the holding means 30.

  Further, the detection unit 90 calculates the total sum of the pixels of each white rectangular Ga in the image as an integral value of the area of the region where the chip jump occurs, and transfers the information to the determination unit 91. The determination unit 91 compares the integrated value of the area of the region where the chip skip has been sent from the detection unit 90 with the preset allowable chip skip amount, and the chip skip amount is within the allowable value. It is determined whether or not.

  For example, when the determination unit 91 determines that the amount of chip jump is within the allowable value and information indicating that the amount of chip jump is within the allowable value is transmitted from the determination unit 91 to the control unit 9C, the control is performed. Under the control of the means 9C, the grinding apparatus 3 further divides a plurality of wafers W continuously.

  For example, when the determination unit 91 determines that the amount of chip skipping exceeds the allowable value and information indicating that the amount of chip skipping exceeds the allowable value is transmitted from the determination unit 91 to the control unit 9C. Under the control of the control means 9C, for example, grinding of another wafer W is stopped. Alternatively, the determination unit 91 issues error information from a speaker or the like or displays error information on a monitor so that the operator can determine that the amount of chip skipping exceeds an allowable value.

  As described above, the wafer processing method according to the present invention includes the imaging step of imaging the wafer W during or after the division step, the presence / absence of chip skipping from the captured image, and the region where the wafer W chip skipping occurs. Therefore, a chip jump exceeding a permissible value is detected on the grinding apparatus 3 during or after the division process in the region where the chip jump occurs and the chip jump of the wafer W occurs. This can be confirmed before the wafer W is continuously divided into a plurality of pieces in a situation where it can occur. The configuration of the grinding apparatus 3 according to the present invention is an optimal apparatus configuration for carrying out the wafer processing method according to the present invention.

  The wafer processing method according to the present invention is not limited to the first to third embodiments, and the configuration of the cutting device 1, the laser processing device 2, and the grinding device 3 shown in the accompanying drawings. The present invention is not limited to this, and can be appropriately changed within a range in which the effects of the present invention can be exhibited.

  For example, in Embodiment 3 of the wafer processing method, instead of cutting the surface Wa of the wafer W by the cutting apparatus 1 to form a half-cut groove, the surface of the wafer W is processed by the laser processing apparatus 2 shown in FIG. The wafer W may be irradiated with a laser beam from the Wa side to form a laser processing groove having a depth that does not reach the back surface Wb of the wafer W on the front surface Wa of the wafer W. Further, the laser beam oscillator 211 of the laser processing apparatus 2 shown in FIG. 5 is a laser beam oscillator capable of oscillating a laser beam having a wavelength that is transmissive to the wafer W, so that the wafer W is moved from the surface Wa side to the wafer W. Alternatively, a laser beam may be irradiated to form a modified layer in the wafer W that serves as a division starting point during grinding.

W: Wafer Wa: Wafer surface D: Device S: Divided line Wb: Wafer back surface T: Dicing tape F: Ring frame 1: Processing device (cutting device) 1A: Base 10: Holding means 100: Adsorption part 100a: holding surface 101: frame
102: Cover 104: Fixed clamp 103: Rotating means 12: Processing feed means
120: Ball screw 121: Guide rail 122: Motor 123: Movable plate
13: Index feeding means 130: Ball screw 131: Guide rail 132: Motor 133: Movable plate
14: Z-axis direction moving means
140: Ball screw 141: Guide rail 142: Motor 143: Holder 145: Wall part 11: Dividing means (cutting means) 110: Cutting blade 111: Spindle 112: Blade cover 113: Cutting water supply nozzle 11A: Housing 19: Alignment means 190 : Imaging unit 9A: Control unit 90: Detection unit 91: Determination unit G1 to G4: Binary image
2: Laser processing apparatus 2A: Base 21: Laser beam irradiation means 210: Housing 211: Laser beam oscillator 212: Condenser 212a: Condensing lens 22: Y-axis direction moving means 220: Ball screw 221: Guide rail 222: Motor 223: Movable plate 9B: Control means 3: Grinding device 3A: Base 3B, 3C: Column 30: Holding means 300: Adsorption part 300a: Holding surface 301: Frame body 31: Coarse grinding means 310: Rotating shaft 311: Spindle housing 312: Motor 313: Grinding wheel 313a: Coarse grinding wheel 32: Finish grinding means 323a: Finish grinding wheel 330: Robot 330a: Arm part 330b: Holding part
331: First cassette 332: Second cassette 333: Positioning means 334: Cleaning means 334a: Cleaning table
335: First transport unit 336: Second transport unit 34: Turntable 35: First grinding feed unit 350: Ball screw 351: Guide rail 352: Motor 353: Lifting unit 36: Second grinding feed unit 360: Ball screw 361: guide rail 362: motor
38A, 38B: a pair of height gauges 381: first height gauge 382: second height gauge 39: imaging means 39a: arm turning means 39b: arm 9C: control means TA: protective tape

Claims (2)

Holding means for holding a wafer having a plurality of division lines formed on the surface in a lattice shape, a dividing means for dividing the wafer held by the holding means along the division lines, and imaging for imaging the wafer A wafer processing apparatus comprising:
The image processing apparatus further includes a detection unit that acquires an image obtained by imaging the wafer divided by the dividing unit or a wafer in the middle of division by the imaging unit and detects presence / absence of chip jump and an area where the chip jump of the wafer occurs. A featured wafer processing device. A wafer having a plurality of division lines formed in a lattice shape on the surface thereof is divided by a processing apparatus having at least a holding means for holding a wafer, a dividing means for dividing the wafer, and an imaging means for imaging the wafer. A wafer processing method for dividing along a planned line,
A holding step for holding the wafer by the holding means;
A dividing step of dividing the wafer held by the holding means along the division planned line;
An imaging step of imaging the wafer during or after the dividing step;
A wafer processing method comprising: a detection step of detecting presence / absence of chip jump and a region where chip jump of a wafer occurs from a captured image.

Images