Cutting and processing device

Abstract

A dividing and processing device is provided. The dividing and processing device (1) includes: a workbench (30) including a plate-shaped transparent plate (300) having a holding surface and a lower illumination (302) that illuminates the holding surface from below; a first storage unit (90) that stores a first image, which is composed of a portion that appears white as the lower illumination light passes through and a portion that appears black as the lower illumination light is blocked by the workpiece when the lower illumination is lit and the cutting slit of the workpiece formed with a cutting slit by a dividing unit (60) held on the holding surface is photographed by a photographing unit (8); a white pixel detection unit (98) that confirms whether there are pixels of a white portion in the first image in a direction perpendicular to the extending direction of the interval path; and a determination unit (97) that determines that the cutting slit is defective when the white pixel detection unit fails to detect white pixels, and determines that the cutting slit is formed normally when white pixels can be detected.

Description

Technical Field

[0001] The present invention relates to a dicing processing apparatus for dicing a workpiece such as a semiconductor wafer into device chips along scribe lines. Background Art

[0002] Devices are formed in a wafer in regions divided by scribe lines called scribe lanes. In the case of performing dicing processing to dice the wafer along the scribe lanes for each device, it is confirmed whether a dicing groove (kerf) penetrates the upper surface and the lower surface of the wafer (for example, refer to Patent Document 1). That is, light is irradiated onto the wafer from one surface side (for example, the upper surface side), and the other surface side (for example, the lower surface side) is imaged by an imaging unit. Whether the dicing groove penetrates the upper surface and the lower surface is confirmed by whether the light passes through the dicing groove and the dicing groove appears white in the captured image.

[0003] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2018-152380

[0004] However, in the method disclosed in Patent Document 1 described above, the wafer after dicing processing is detached from the chuck table of the dicing apparatus, and then light is irradiated onto the wafer for the above-mentioned confirmation. Therefore, in the case where it is confirmed that the dicing groove does not penetrate the upper and lower surfaces of the wafer, it is difficult to perform dicing processing on the wafer again so that the dicing groove penetrates the upper and lower surfaces.

[0005] Therefore, in the case of dicing a workpiece along scribe lines for each device, there is a problem as follows: Before or after processing, it is confirmed whether the workpiece on the chuck table has been or can be completely cut by a dicing groove (kerf) having an appropriate width that penetrates the upper and lower surfaces. Summary of the Invention

[0006] The present invention provides a dicing processing apparatus that dices a workpiece such as a semiconductor wafer into device chips along scribe lines.

[0007] The present invention for solving the above problems is a dicing processing apparatus, which includes: a chuck table having a holding surface for holding a workpiece having devices formed in regions divided by streets; a dicing unit that forms a slit along the street of the workpiece held by the chuck table and slices the workpiece into small pieces for each device; an X-axis feed unit that relatively feeds the chuck table and the dicing unit in the X-axis direction parallel to the extending direction of the street; a Y-axis feed unit that relatively indexes and feeds the chuck table and the dicing unit in the Y-axis direction perpendicular to the X-axis direction on a horizontal plane; and an imaging unit that images the slit from above the workpiece held by the chuck table. The chuck table includes: a plate-shaped transparent plate made of a transparent member, having a suction port that communicates the upper surface with a suction source so that the upper surface functions as a holding surface; a base that supports the transparent plate; and a lower illumination disposed between the transparent plate and the base for illuminating the holding surface. The dicing processing apparatus includes: a first storage unit that stores a first image, which is composed of a white portion that appears white due to the light of the lower illumination passing through and a black portion that appears black due to the light of the lower illumination being blocked by the workpiece when the lower illumination is lit and the imaging unit images the slit of the workpiece having the slit formed by the dicing unit held on the holding surface; a white pixel detection unit that detects whether there are pixels of the white portion in the first image in a direction perpendicular to the extending direction of the street; and a determination unit that determines that the slit is defective when the white pixel detection unit fails to detect white pixels, and determines that the slit is normally formed when the white pixel detection unit can detect white pixels.

[0008] Preferably, the dicing processing apparatus includes: a first measurement unit that counts the number of pixels of the white portion in the first image in a direction perpendicular to the extending direction of the street and measures the width of the white portion; and a first determination unit that determines that the slit is defective when the first measurement width measured by the first measurement unit is less than a preset first width, and determines that the slit is defective when the first measurement width exceeds a preset second width, and determines that the slit is normally formed when the first measurement width is equal to or greater than the preset first width and equal to or less than the preset second width.

[0009] Preferably, the dicing apparatus has: an upper illumination unit that illuminates a workpiece held by the chuck table from above the workpiece; a second storage unit that stores a second image, which is an image of a slit taken from above the workpiece with the upper illumination unit turned on and the lower illumination unit turned off, and the slit appears as a black portion that is darker; a second measurement unit that counts the number of pixels of the black portion of the second image in a direction perpendicular to the extending direction of the scribe lane to measure the width of the slit on the upper surface of the workpiece; and a second determination unit that determines whether the slit is formed vertically from the upper surface of the workpiece toward the lower surface or obliquely based on the measurement results measured by the first measurement unit and the measurement results measured by the second measurement unit.

[0010] Preferably, the dicing apparatus has a third determination unit that, when it is determined by the second determination unit that the slit is formed obliquely, determines whether the upper surface and the lower surface of the slit can be included within the width of the scribe lane even according to the inclination of the slit. When the third determination unit determines that the upper surface and the lower surface of the slit can be included within the width of the scribe lane, the following Y-axis control is performed: the chuck table and the dicing unit are relatively moved in the Y-axis direction so that the upper surface and the lower surface of the slit enter within the width of the scribe lane.

[0011] Regarding the dicing apparatus of the present invention, the chuck table has: a plate-shaped transparent plate made of a transparent member and having a suction port that communicates the upper surface with a suction source so that the upper surface functions as a holding surface; a base that supports the transparent plate; and a lower illumination unit disposed between the transparent plate and the base to illuminate the holding surface. The dicing apparatus has: a first storage unit that stores a first image, which is composed of a white portion that appears white due to the light of the lower illumination unit passing through and a black portion that appears black due to the light of the lower illumination unit being blocked by the workpiece when the lower illumination unit is turned on and the slit of the workpiece formed by the dicing unit on the holding surface is imaged by the imaging unit; a white pixel detection unit that detects whether there are pixels of the white portion in the first image in a direction perpendicular to the extending direction of the scribe lane; and a determination unit that determines that the slit is defective when the white pixel detection unit fails to detect white pixels, and determines that the slit is formed normally when the white pixel detection unit can detect white pixels. Thus, it is possible to confirm whether the slit formed in, for example, the outer peripheral remaining area of the workpiece penetrates the upper and lower surfaces of the workpiece while the workpiece is held on the chuck table, and using the result of this determination, appropriate dicing processing can be performed on the workpiece thereafter.

[0012] The dividing and processing device has: a first measurement unit that counts the number of pixels of the white portion of the first image in a direction perpendicular to the extending direction of the interval track and measures the width of the white portion; and a first determination unit that determines that the cutting seam is defective when the first measurement width measured by the first measurement unit is less than a preset first width, and determines that the cutting seam is defective when the first measurement width exceeds a preset second width, and determines that the cutting seam is formed normally when the first measurement width is equal to or greater than the preset first width and less than the preset second width. Thus, it is possible to confirm whether the cutting seam formed in, for example, the outer peripheral remaining area of the workpiece penetrates the upper and lower surfaces of the workpiece while the workpiece is held on the chuck table, and it is possible to confirm whether the cutting seam is formed with an appropriate width. Using the result of this determination, an appropriate dividing and processing can be performed on the workpiece thereafter.

[0013] In addition, the dividing and processing device of the present invention has: an upper illumination that illuminates the workpiece from above the workpiece held by the chuck table; a second storage unit that stores a second image, which is an image of the cutting seam taken as a black portion that appears darker when the upper illumination is turned on and the lower illumination is turned off and the cutting seam is photographed from above the workpiece by the photographing unit; a second measurement unit that counts the number of pixels of the black portion of the second image in a direction perpendicular to the extending direction of the interval track and measures the width of the cutting seam on the upper surface of the workpiece; and a second determination unit that determines whether the cutting seam is formed vertically or obliquely from the upper surface of the workpiece to the lower surface based on the measurement results measured by the first measurement unit and the second measurement unit. Thus, it is possible to confirm in advance whether the cutting seam is formed vertically from the upper surface of the workpiece to the lower surface while the workpiece is held on the chuck table, for example, before actually performing the processing of dividing the workpiece into chips.

[0014] The dividing and processing device has a third determination unit. When the second determination unit determines that the cutting seam is formed obliquely, the third determination unit determines whether it is possible to include the upper and lower surfaces of the cutting seam within the width of the interval track even according to the inclination of the cutting seam. When the third determination unit determines that it is possible to include the upper and lower surfaces of the cutting seam within the width of the interval track, the following Y-axis control is performed: the chuck table and the dividing unit are relatively moved in the Y-axis direction so that the upper and lower surfaces of the cutting seam enter the width of the interval track, so that the upper and lower surfaces of the cutting seam can enter the width of the interval track relative to the workpiece held by the chuck table and the processing can be performed by the dividing unit. Description of the Drawings

[0015] Figure 1 It is a perspective view showing an example of the dividing and processing device.

[0016] Figure 2 This is a cross-sectional view illustrating a state in which the lower illumination is turned on and the cutting slit of the workpiece is imaged by the imaging unit to form a captured image.

[0017] Figure 3 This is an explanatory diagram showing the first image G1 that shows the cutting slit captured by the imaging unit with the lower illumination turned on.

[0018] Figure 4 This is an explanatory diagram showing the first binarized image G0 that shows the cutting slit captured by the imaging unit with the lower illumination turned on.

[0019] Figure 5 This is an explanatory diagram illustrating the state of the rows and columns of pixels shown in the first image G1 that shows the cutting slit captured by the imaging unit with the lower illumination turned on.

[0020] Figure 6 This is a cross-sectional view illustrating a normally formed cutting slit.

[0021] Figure 7 This is an explanatory diagram illustrating the situation of determining whether the cutting slit is normally formed based on the first image G11 that shows the cutting slit captured by the imaging unit with the lower illumination turned on.

[0022] Figure 8 This is a cross-sectional view illustrating a cutting slit that is not normally formed.

[0023] Figure 9 This is an explanatory diagram illustrating the situation of determining whether the cutting slit is normally formed based on the first image G12 that shows the cutting slit captured by the imaging unit with the lower illumination turned on.

[0024] Figure 10 This is a cross-sectional view illustrating a cutting slit that is not normally formed due to the pouring of the resin layer.

[0025] Figure 11 This is a cross-sectional view illustrating a state in which the upper surface of the cutting slit of the workpiece is imaged by the imaging unit with the lower illumination turned off and the upper illumination turned on to form a captured image.

[0026] Figure 12 This is an explanatory diagram showing the second image G2 that shows the upper surface of the cutting slit captured by the imaging unit with the lower illumination turned off and the upper illumination turned on.

[0027] Figure 13This is an explanatory diagram for the case of determining whether the slit is formed vertically from the upper surface (front surface) to the lower surface (back surface) of the workpiece or obliquely by the second determination unit.

[0028] Figure 14 This is a cross-sectional view for explaining a slit that is not formed vertically from the upper surface to the lower surface of the workpiece but is formed obliquely toward the Y-axis direction side.

[0029] Figure 15 This is a cross-sectional view for explaining the following slit: The third determination unit determines that the upper surface and the lower surface of the slit can be included within the width of the inter-channel, and performs Y-axis control to move the chuck table and the dividing unit relative to each other in the Y-axis direction in such a way that the upper surface and the lower surface of the slit enter the width of the inter-channel, thereby forming the slit in such a way that the upper surface and the lower surface enter the width of the inter-channel.

[0030] Reference Numeral Explanation

[0031] W: Workpiece; Wa: Front surface of the workpiece; S: Inter-channel; D: Device; Wb: Back surface of the workpiece; T: Dicing tape; F: Ring frame; J: Resin layer; WS: Workpiece group; 1: Dividing processing device; 10: Base; 10A: Column; 190: Cassette; 191: Cassette mounting table; 192: Cassette elevator; 193: Push-pull member; 194: Centering guide; 20: Y-axis moving unit; 21: X-axis moving unit; 30: Chuck table; 300: Transparent plate; 300a: Holding surface; 300b: Suction port; 301: Base; 301a: Ring-shaped wall; 301b: Recess; 302: Lower illumination; 39: Suction source; 38: Cooling water supply source; 32: Rotation unit; 33: Fixed jig; 60: Dividing unit; 601: Laser oscillator; 609: Irradiation head; 609a: Condensing lens; 8: Imaging unit; 80: Imaging cover; 81: Cylinder; 82: Upper illumination; 820: Coaxial epi-illumination; 84: Illumination box; 821: Oblique light illumination; 83: Imaging section; 17: Conveying unit; 170: Conveying pad; 171: Conveying pad moving unit; 172: Lifting unit; 18: Cleaning unit; 9: Control unit; 90: First storage unit; 91: First measurement unit; 92: First determination unit; 93: Second storage unit; 94: Second measurement unit; 95: Second determination unit; 96: Third determination unit; 97: Determination unit; 98: White pixel detection unit. Detailed Implementation Manner

[0032] Figure 1The dicing processing apparatus 1 of the present invention shown is, for example, an apparatus that irradiates a workpiece W held by a chuck table 30 with a laser beam to perform processing (e.g., ablation processing) for dicing. Additionally, the dicing processing apparatus 1 may also be a cutting apparatus that performs cutting processing on the workpiece W using a rotating cutting tool to form slits along the scribe lanes S at intervals for dicing.

[0033] Figure 1 and Figure 2 The workpiece W shown is, for example, a semiconductor wafer with a circular outer shape having silicon as its base material. In Figure 1 , on the front surface Wa facing upward, a plurality of scribe lanes S intersecting perpendicularly are formed, and devices D such as ICs are respectively formed in each region divided into a lattice shape by the scribe lanes S. Additionally, besides silicon, the workpiece W may be formed of gallium arsenide, sapphire, ceramic, resin, gallium nitride, silicon carbide, or the like. And, a wiring layer (not shown) or the like is further laminated on the device D on the front surface Wa of the workpiece W, and the front surface Wa is sealed with a resin layer J in such a manner as to cover the device D and the scribe lanes S together.

[0034] Alternatively, the workpiece W may also be a plate-shaped wafer not sealed with the resin layer J.

[0035] The workpiece W, for example, is in a state where a circular dicing tape T is adhered to its back surface Wb. Additionally, the outer peripheral portion of the dicing tape T is adhered to a ring-shaped frame F. Thus, the workpiece W is integrated with the ring-shaped frame F by means of the dicing tape T and becomes a workpiece group WS that can be operated using the ring-shaped frame F.

[0036] On the base 10 of the dicing processing apparatus 1, there is a Y-axis feed unit 20 that reciprocally moves the chuck table 30 in the Y-axis direction as the indexing feed direction. The Y-axis feed unit 20 includes: a ball screw 200 having an axis in the Y-axis direction; a pair of guide rails 201 disposed in parallel with the ball screw 200; a motor 202 that rotates the ball screw 200; and a movable plate 203, the nut inside which is screwed with the ball screw 200, and the bottom of the movable plate 203 is in sliding contact with the guide rail 201. And, when the motor 202 rotates the ball screw 200, the movable plate 203 is guided by the guide rail 201 and moves in the Y-axis direction accordingly, and the chuck table 30 disposed on the movable plate 203 by means of the X-axis feed unit 21 moves in the Y-axis direction as the movable plate 203 moves.

[0037] On the movable plate 203, there is an X-axis feed unit 21 that reciprocally moves the chuck table 30 in the X-axis direction, which is perpendicular to the Y-axis direction on the horizontal plane and serves as the machining feed direction. The X-axis feed unit 21 includes: a ball screw 210 having an axis in the X-axis direction; a pair of guide rails 211 disposed in parallel with the ball screw 210; a motor 212 that rotates the ball screw 210; and a movable plate 213, the nut inside which is screwed with the ball screw 210, and the bottom of the movable plate 213 is in sliding contact with the guide rails 211. And 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 accordingly, and the chuck table 30 disposed on the movable plate 213 moves in the X-axis direction as the movable plate 213 moves.

[0038] holding the workpiece group WS Figure 1 、 Figure 2 The outer shape of the chuck table 30 shown in a plan view is circular, and the chuck table 30 has at least: a plate-shaped transparent plate 300 made of a transparent member, having a suction port 300b that connects the upper surface to the suction source 39 in such a way that the upper surface functions as a holding surface 300a; a base 301 that supports the transparent plate 300; and a lower illumination 302 disposed between the transparent plate 300 and the base 301 to illuminate the holding surface 300a.

[0039] The transparent plate 300 is obtained by forming a transparent member such as glass or acrylic into a circular plate shape in a plan view, and its flat upper surface serves as the holding surface 300a. The holding surface 300a has a plurality of suction ports 300b that are equally spaced in the circumferential and radial directions and extend toward the inside of the transparent plate 300 in the -Z direction. The plurality of suction ports 300b merge into a single suction flow path 300c inside the transparent plate 300, for example.

[0040] In addition, on the holding surface 300a, there may be formed: a plurality of circular suction grooves formed concentrically with the rotation center of the chuck table 30; and connecting grooves that extend radially from the circular suction grooves equally in the circumferential direction and connect the circular suction grooves to each other. Suction ports 300b may also be formed at the bottoms of the suction grooves and the connecting grooves.

[0041] The base 301 that supports the transparent plate 300 is formed in a circular shape in a plan view, and a ring-shaped wall 301a of a predetermined height is erected from the outer peripheral edge of the upper surface of the base 301. The area inside the ring-shaped wall 301a serves as a recess 301b for accommodating the lower illumination 302.

[0042] The upper surface of the annular wall 301a serves as a stepped surface with a first-order step difference, and is in a state where the transparent plate 300 is fitted on this stepped surface. A predetermined space is provided between the lower illumination 302 mounted on the bottom surface of the recess 301b and the transparent plate 300.

[0043] The lower illumination 302 and the transparent plate 300 are arranged to face each other in the Z-axis direction. The lower illumination 302 illuminates the workpiece W attracted and held by the holding surface 300a through the transparent plate 300 and the dicing tape T. The lower illumination 302 is constituted by, for example, a plurality of LEDs (Light Emitting Diodes), but is not limited thereto, and may also be a xenon lamp or the like. The lower illumination 302 emits light when power is supplied from the connected power supply 302a, and irradiates light from the back surface Wb side of the workpiece W toward the front surface Wa side.

[0044] The lower end side of the suction flow path 300c extending inside the transparent plate 300 opens, for example, on the bottom surface of the base 301 through the inside of the base 301. Further, the suction flow path 300c communicates with a suction source 39 such as an ejector mechanism or a vacuum generating device via a metal pipe or a flexible resin pipe.

[0045] For example, a cooling water flow path 301d for supplying cooling water is formed inside the base 301, and a cooling water supply source 38 is connected to the cooling water flow path 301d. The cooling water supply source 38 causes the cooling water to flow into the cooling water flow path 301d, and the cooling water circulates while cooling the base 301 from the inside. For example, during the process in which the lower illumination 302 generates heat due to light irradiation, the temperature of the chuck table 30 can be maintained at an appropriate temperature by the cooling water supplied from the cooling water supply source 38.

[0046] As Figure 1 shown, the chuck table 30 can be rotated by a rotation unit 32 disposed on the bottom surface side and having an axial direction of the Z-axis direction (vertical direction). Four fixing jigs 33 for fixing the annular frame F are evenly arranged in the circumferential direction around the chuck table 30.

[0047] A cassette mounting table 191 is disposed on the front surface side (-Y direction side) of the dicing apparatus 1, and a cassette 190 that stores a plurality of workpiece groups WS in a shelf-like manner is mounted on the cassette mounting table 191. The cassette mounting table 191 is provided on a cassette elevator 192 that reciprocates in the Z-axis direction, and the height position can be adjusted.

[0048] Behind the cassette mounting table 191, a centering guide 194 composed of a pair of guide rails is provided. The centering guide 194 positions the workpiece group WS pulled out from the cassette 190 at a certain position. Each of the guide rails having an L-shaped cross section and extending in the Y-axis direction can move away from or approach each other in the X-axis direction and is arranged in such a way that the stepped guide surfaces (inner side surfaces) face each other. When loading the workpiece W to be machined onto the chuck table 30, the workpiece group WS is pulled out from the cassette 190 by the Figure 1 push-pull member 193 shown and placed on the centering guide 194. In addition, after the workpiece group WS that has been machined and cleaned is placed on the centering guide 194, it is pushed into the cassette 190 by the push-pull member 193.

[0049] When loading the workpiece group WS, the pair of guide rails of the centering guide 194 approach each other to support the outer peripheral edge portion of the annular frame F, and position (center) the workpiece group WS relative to the chuck table 30.

[0050] A column 10A is erected behind the base 10 (+Y direction side), and a dividing unit 60 is provided on the column 10A.

[0051] The dividing unit 60 has, for example, a housing 600 in a substantially rectangular parallelepiped shape. The housing 600 extends horizontally from the column 10A in the -Y direction, and an irradiation head 609 is provided at the front end of the housing 600.

[0052] For example, a laser oscillator 601 such as a YAG pulsed laser is provided in the housing 600. The laser beam horizontally emitted from the laser oscillator 601 is reflected in the -Z direction by a mirror (not shown) and enters the condenser lens 609a inside the irradiation head 609, where it is condensed and irradiated onto the workpiece W held by the chuck table 30. 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 unit (not shown).

[0053] At the front end of the housing 600, a photographing unit 8 is arranged side by side with the irradiation head 609 in the X-axis direction. The photographing unit 8 photographs the slit from above the workpiece W held by the chuck table 30.

[0054] Regarding the photographing unit 8, when a slit is to be formed on the workpiece W attracted and held by the chuck table 30, the photographing unit 8 is also used for alignment such as pattern matching for identifying the coordinate position of the interval track S of the workpiece W on which the laser beam is to be irradiated.

[0055] As Figure 2 shown, the photographing unit 8 is mounted on a photographing cover 80 (in Figure 1Inside the (not shown in the figure), the photographing cover 80 is installed at the front end of the housing 600, and the photographing unit 8 is configured to obtain reflected light from the workpiece and light that is irradiated from the lower illumination 302 and passes upward through the workpiece W through an opening 800 formed on the bottom surface of the photographing cover 80.

[0056] The photographing unit 8 includes: a cylindrical barrel 81 that shields external light; and an upper illumination 82 that illuminates the workpiece W from above the workpiece W held by the chuck table 30. A coaxial epi-illumination 820 that constitutes the upper illumination 82 is installed on the side surface of the barrel 81. The coaxial epi-illumination 820 is configured, for example, to Figure 2 transmit the light generated by a light source 820a (such as an LED or a xenon lamp, etc.) shown in the figure to the inside of the barrel 81 using a transmission optical system 820b such as an optical fiber. The amount of light emitted by the light source 820a can be adjusted by a voltage regulator (not shown) or the like.

[0057] The photographing unit 8 includes: a half mirror 822 disposed inside the barrel 81 that reflects the light incident via the coaxial epi-illumination 820 downward for direction conversion; an objective lens 823 disposed below the half mirror 822 inside the barrel 81 for the light reflected by the half mirror 822 to enter; and a photographing unit 83 disposed above the half mirror 822 that, for example, performs photoelectric conversion on the reflected light reflected by the workpiece W and captured by the objective lens 823 and outputs it as image information.

[0058] The half mirror 822 has the function of guiding the light generated by the coaxial epi-illumination 820 to the workpiece W and the function of transmitting the reflected light from the workpiece W and guiding it to the photographing unit 83. The optical axis of the objective lens 823 is perpendicular to the holding surface 300a of the chuck table 30. Thus, the light generated by the coaxial epi-illumination 820 is reflected by the half mirror 822 to be parallel to the optical axis of the objective lens 823 and irradiates the front surface Wa of the workpiece W from directly above through the objective lens 823.

[0059] An illumination box 84 for oblique light illumination that irradiates the workpiece W from an oblique upper direction is installed at the lower part of the barrel 81 of the photographing unit 8. A photographing opening 840 is formed at the center of the bottom surface of the illumination box 84. A plurality of light emitting bodies 821a (such as LEDs) are disposed at regular intervals along the circumferential direction on the lower part of the inner peripheral side surface of the illumination box 84, and an oblique light illumination 821 that irradiates the workpiece W with light from an oblique upper direction is formed by surrounding the photographing opening 840 with the plurality of light emitting bodies 821a. A power source (not shown) is connected to each light emitting body 821a via a power cable 821b passing through the illumination box 84. In addition, the bottom surface of the illumination box 84 is formed of a transparent annular plate 821d, and the light emitted by each light emitting body 821a passes through the annular plate 821d and irradiates the workpiece W at an angle inclined with respect to the direction perpendicular to the upper surface of the workpiece W.

[0060] In this way, the photographing unit 8 can photograph in a state where the front surface Wa of the workpiece W is uniformly irradiated from directly above by the coaxial epi-illumination 820 that constitutes the upper illumination 82, and the front surface Wa of the workpiece W is three-dimensionally irradiated from an obliquely upper direction by the oblique light illumination 821 that constitutes the upper illumination 82.

[0061] Figure 2 The photographing unit 83 shown, for example, receives the light irradiated from the coaxial epi-illumination 820 or the oblique light illumination 821 and reflected by the workpiece W via the objective lens 823.

[0062] The photographing unit 83 is formed by two-dimensionally arranging a plurality of light receiving elements such as CCDs, for example. The data transmitted according to the intensity of the light received by each pixel of the light receiving elements of the photographing unit 83 is expressed in 8-bit gradations of brightness values, that is, 256 gradations from 0 to 255, for example.

[0063] In addition, the structure of the photographing unit 8 is not limited to the example shown in this embodiment.

[0064] For example, as Figure 1 shown, the dividing processing apparatus 1 has a transfer unit 17 that transfers the processed workpiece W out of the chuck table 30. The transfer unit 17 has: a transfer pad 170 that holds the workpiece group WS by means of an annular frame F; a transfer pad moving unit 171 that moves the transfer pad 170 in the X-axis direction; and a lifting unit 172 that lifts and lowers the transfer pad 170.

[0065] The transfer pad 170 has, for example, an H-shaped outer shape in plan view, and the lower end side of the lifting unit 172 is mounted on the upper surface of the transfer pad 170. The transfer pad 170 has four suction pads 170a on its lower surface that adsorb the annular frame F. Each suction pad 170a communicates with an unillustrated suction source that generates a suction force.

[0066] The transfer pad moving unit 171 is disposed, for example, on the front surface of the column 10A. The transfer pad moving unit 171 has: a ball screw 171a having an axis in the X-axis direction; a pair of guide rails 171b disposed in parallel with the ball screw 171a; a motor 171c connected to one end of the ball screw 171a; and a movable block 171d having a nut screwed onto the ball screw 171a inside. The movable block 171d supports the lifting unit 172. 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, and the transfer pad 170 mounted on the lower end side of the lifting unit 172 moves in the Y-axis direction.

[0067] The lifting unit 172 is composed of a cylinder or an electric cylinder, etc., and raises and lowers the transfer pad 170 in the Z-axis direction.

[0068] A cleaning unit 18 is disposed under the movement path of the transfer pad 170. The cleaning unit 18 is, for example, a single-piece rotary cleaning device that sucks and holds the processed workpiece group WS conveyed by using a rotary table 180, and sprays a cleaning liquid onto the workpiece W from a cleaning nozzle 181 that rotates above the rotary table 180 to perform cleaning.

[0069] As Figure 1 shown, the dicing device 1 has a control unit 9 that controls the entire device. The control unit 9 is composed of an arithmetic device such as a CPU and a storage device such as a ROM, and causes the arithmetic device to operate according to a program stored in the storage device, thereby executing various controls required for processing. The control unit 9 is electrically connected to, for example, the X-axis feed unit 21, the Y-axis feed unit 20, the power supply 302a that turns on and off the lower illumination 302, and the power supplies of the upper illumination 82, etc. Under the control of the control unit 9, the machining feed operation of the chuck table 30 based on the X-axis feed unit 21, the indexing feed operation of the chuck table 30 based on the Y-axis feed unit 20, the lighting operation of the lower illumination 302 based on the power supply 302a, and the lighting operation of the upper illumination 82 are appropriately performed.

[0070] Hereinafter, the operations of the respective parts of the dicing device 1 will be described in the case where laser processing is performed on the workpiece W using the dicing device 1 shown above Figure 1 and it is determined whether a slit (dicing groove) is normally formed on the workpiece W.

[0071] Figure 1 shown, a push-pull member 193 pulls out a workpiece group WS from inside the cassette 190 placed on the cassette mounting table 191 and places the ring frame F on the centering guide 194. And, while the pair of guide rails of the centering guide 194 approach each other in the X-axis direction to support the outer peripheral edge portion of the ring frame F, centering of the workpiece group WS is performed.

[0072] The centered workpiece group WS is further conveyed from the centering guide 194 and placed on the holding surface 300a of the chuck table 30. The fixing jig 33 clamps and fixes the ring frame F, and the attractive force generated by Figure 2 shown suction source 39 is transmitted to the holding surface 300a through the suction flow path 300c and the suction port 300b, so that the chuck table 30 sucks and holds the workpiece W with the dicing tape T interposed therebetween on the holding surface 300a. In addition, the center of the holding surface 300a of the chuck table 30 and the center of the sucked and held workpiece W are in a substantially coincident state.

[0073] Next, the position of the scribe lane S, which is a reference for irradiating the workpiece W with a laser beam to form a slit, is detected by an alignment unit (not shown) provided in the dicing processing apparatus 1. That is, for example, with the upper illumination 82 lit, the scribe lane S on the front surface Wa of the workpiece W is imaged by the imaging unit 8, and based on the captured image thus formed, the alignment unit performs image processing such as pattern matching to detect the coordinate position of the scribe lane S of the workpiece W.

[0074] In addition, the chuck table 30 is rotated by a predetermined angle θ to perform θ alignment in which the scribe lane S is aligned parallel to the X-axis direction.

[0075] With the detection of the coordinate position of the scribe lane S, the chuck table 30 moves in the Y-axis direction to perform alignment between the scribe lane S and the irradiation head 609 of the dicing unit 60. This alignment is performed, for example, such that the center line of the scribe lane S is positioned directly below the focal point of the irradiation head 609. Next, the focal point position of the laser beam converged by the condenser lens 609a is aligned at a predetermined height position in the thickness direction of the workpiece W (for example, the height position of the front surface Wa of the workpiece W).

[0076] Normally, the workpiece W is divided and patterned by the scribe lane S up to the outer peripheral edge, but the outer peripheral side region (outer peripheral remaining region) of the workpiece W diced into small pieces becomes waste scraps such as triangular small pieces. Therefore, in the present embodiment, laser processing is performed on the outer peripheral remaining region of the workpiece W that does not become a rectangular chip to determine whether a slit (dicing groove) is formed normally. Alternatively, laser processing may be performed on the device region (region inside the outer peripheral remaining region) of the workpiece W that becomes a regular rectangular chip to determine whether a slit is formed normally.

[0077] Figure 1 The laser oscillator 601 shown oscillates a laser beam having a wavelength that is absorbable by the workpiece W, and converges and irradiates the laser beam onto the workpiece W from the front surface Wa side. In addition, the workpiece W is fed in the -X direction, which is the forward direction, at a predetermined processing feed rate, and the laser beam is irradiated along the scribe lane S onto the outer peripheral remaining region of the workpiece W, thereby ablating the resin layer J and the workpiece W and completely cutting the workpiece W along the scribe lane S. That is, a straight groove-shaped slit K having a predetermined length as shown is formed in the workpiece W along the scribe lane S. Figure 2 The shown straight groove-shaped slit K of a predetermined length.

[0078] Next, through Figure 2The photographing unit 8 shown photographs the slit K formed from the upper surface of the workpiece W, that is, the front side Wa, toward the back side Wb. That is, for example, when the photographing unit 8 is focused on the front side Wa of the workpiece W and the center line of the spacing track S is positioned directly below the optical axis of the photographing unit 8, the lower lighting 302 is turned on and the illumination light (for example, visible light) is irradiated upward. The upper lighting 82 is turned off. The illumination light passes through the transparent plate 300 and irradiates the workpiece W from the back side Wb through the scribe tape T. The light emitted from the workpiece W upward through the slit K is received by the light receiving element of the photographing unit 83 through an optical system not shown in the figure, forming an image showing the slit K. Figure 3 The captured image G1 shown (hereinafter referred to as the first image G1 ) is shown.

[0079] Alternatively, a plurality of first images G1 may be formed.

[0080] The first image G1 is, for example, a collection of pixels of a predetermined size expressed in 8-bit levels, that is, 256 levels from 0 to 255. The brightness value of each pixel of the first image G1 formed is determined by the amount of light incident on each pixel of the light receiving element of the imaging unit 83. Figure 2 The amount of incident light to the light receiving element corresponding to the slit K of the workpiece W shown is very large, and the brightness value of one pixel is close to 255, which is close to white. The incident light to the light receiving element corresponding to the part other than the slit K on the front side Wa of the workpiece W is shielded by the workpiece W and thus almost disappears. This pixel is close to the brightness value of 0, which is close to black.

[0081] The imaging unit 8 sends the first image G1 showing the front surface Wa of the workpiece W to the Figure 1 The control unit 9 shown. The first image G1 is stored in the control unit 9 Figure 1 The first storage unit 90 shown is composed of a storage element and the like.

[0082] For example, the first image G1 stored in the first storage unit 90 is binarized so that the portion where the brightness value of one pixel is greater than a predetermined threshold is white, and the portion where the brightness value of one pixel is less than the predetermined threshold is black. Figure 3 The first image G1 shown is a first image of a wider range.

[0083] like Figure 3 As shown, the first image G1 stored in the first storage unit 90 is displayed on a virtual output screen B (X-axis Y-axis orthogonal coordinate plane) of a predetermined resolution. In the first image G1 displayed on the output screen B, the slit K is Figure 2The light of the lower illumination 302 shown is displayed in white through the workpiece W, that is, a set of pixels having a luminance value equal to or higher than a specified threshold value. The portion of the front surface Wa of the workpiece W other than the slit K is displayed in black as a black portion where the light of the lower illumination 302 is blocked by the workpiece W, that is, a set of pixels having a luminance value less than the specified threshold value.

[0084] For example, the first image captured by the imaging unit 8 and subjected to binarization processing is Figure 4 the first image G0 shown. And, as Figure 1 shown, the white pixel detection unit 98 included in the control unit 9 detects whether there are pixels in the white portion in the direction (Y-axis direction) perpendicular to the extending direction (X-axis direction) of the interval path S in the first image G0. For example, the X-axis direction, which is the extending direction of the slit K, is set as a row, and the Y-axis direction, which is perpendicular to the extending direction of the slit K on the horizontal plane, is set as a column. And the white pixel detection unit 98 detects whether there are white pixels for each column. For example, there are white pixels in the first column to the seventh column starting from the -X direction, and thus the columns having white pixels (displayed as 0 in Figure 4 ) are stored in the first storage unit 90. There are no white pixels in the eighth column to the ninth column starting from the -X direction, and thus the columns having no white pixels (displayed as 1 in Figure 4 ) are stored in Figure 1 the first storage unit 90 shown. The white pixel detection unit 98 detects whether there are the above-mentioned white pixels for all columns in the first image G0.

[0085] In parallel with the white pixel detection unit 98 detecting whether there are white pixels for each column, Figure 1 the determination unit 97 included in the control unit 9 shown determines whether the slit K in each column is defective or normal. That is, it is determined that the slit K in the first column to the seventh column starting from the -X direction, which are columns having white pixels, is formed normally, that is, the slit K penetrates the workpiece W from the front surface Wa to the back surface Wb. On the other hand, it is determined that the slit K in the eighth column to the ninth column starting from the -X direction is defective, that is, the slit K does not penetrate the workpiece W from the front surface Wa to the back surface Wb. The determination unit 97 makes this determination for all columns in the first image G0.

[0086] For example, the determination unit 97 can calculate the number of columns determined to have defective slit K and thus calculate the percentage in all columns of the first image G0. The determination unit 97, for example, compares the determination value of what percentage or more the percentage should be if it is pre-stored in the first storage unit 90 so that the slit K in the first image G0 can be determined to be formed normally as a whole with the calculated percentage. As a result, the determination unit 97, for example, determines that Figure 4The entire slit K shown in the first image G0 is not formed properly, which is defective. In addition, the determination unit 97 can also determine that the entire slit K shown in the first image G0 is not formed properly when there is even one column in which the slit K is determined to be defective. For example, when the slit K is not fully displayed on the first image G0, that is, when the white pixel detection unit 98 fails to detect white pixels in all columns, the determination unit 97 determines that the slit K does not completely penetrate the workpiece W, which is defective. For example, when the determination unit 97 determines that the slit K is defective because there is one column in which no white pixel is detected, the determination unit 97 can issue an alarm or warning indicating that the dividing processing device 1 cannot perform normal dividing processing on the workpiece W. In this case, the operator who receives the alarm or warning checks the dividing processing device 1 and grasps the main cause of the defect of the slit K, that is, the main cause of the part where the upper and lower surfaces of the workpiece W are not penetrated by laser ablation, so as to improve the dividing processing device 1.

[0087] (1) Method 1 for determining the normality or defectiveness of the slit based on the first determination unit 92

[0088] In the present embodiment, for example, for Figure 3 the first image G1 shown, the determination unit 97 determines the normality or defectiveness of the slit K. Even when it is determined that the slit K is normal (penetrates the upper and lower surfaces of the workpiece W), it is impossible to determine whether the slit K is formed with an appropriate width. Therefore, Figure 1 the first determination unit 92 included in the control unit 9 shown determines whether the slit K is normally formed with an appropriate width.

[0089] As Figure 1 shown, the control unit 9 has, for example, a first measurement unit 91. The first measurement unit 91 counts the number of pixels in the white part of the first image G1 in a direction (Y-axis direction) perpendicular to the extending direction (X-axis direction) of the interval path S in the first image G1 displayed on the output screen B, and measures the width of the white part as the width of the slit K. For example, a prescribed first width L1 and a second width L2 regarding the width of the slit K are stored in the first storage unit 90 in advance. The first width L1 and the second width L2 are values selected experimentally, empirically, or theoretically, and are Figure 1 the values stored for the first determination unit 92 shown to determine whether the slit K is normally formed on the workpiece W. The first width L1 and the second width L2 are smaller than the width Sa of the interval path S, and the first width L1 is set smaller than the second width L2.

[0090] And, for example, in Figure 3On the first image G1 shown, the width Sa of the interval track S, the first width L1, and the second width L2 are shown with the center line of the interval track S as the center.

[0091] In addition, the first width L1 and the second width L2 are determined by the desired length of one side of the divided chip.

[0092] In addition, for example, as Figure 5 shown, the X-axis direction, which is the extending direction of the slit K, is set as the row, and the Y-axis direction, which is perpendicular to the extending direction of the slit K on the horizontal plane, is set as the column. And the first measurement unit 91 calculates the number of pixels displayed in white for each column. As Figure 5 shown, in the first image G1, the width of the white part measured by the first measurement unit 91, that is, the width of the slit K, is, for example, the first measurement width La of 6 pixels. For example, when the value of one side of a pixel is 10 μm, the first measurement width La is 60 μm.

[0093] Next, as Figure 1 shown, the first determination unit 92 included in the control unit 9 determines that the first measurement width La measured by the first measurement unit 91 is equal to or greater than the preset first width L1 and equal to or less than the second width L2, and thus determines that the slit K is formed normally. That is, as Figure 6 shown, the slit K that penetrates the workpiece W from the front surface Wa to the back surface Wb is formed with an appropriate first measurement width La in a state where its center line coincides with the center line of the interval track S. Therefore, it is determined that the slit K penetrates the workpiece W vertically from the front surface Wa to the back surface Wb and is formed normally.

[0094] For example Figure 2 the first image captured by the imaging unit 8 shown is Figure 7 the first image G11 shown. The first measurement unit 91 calculates the number of pixels displayed in white for each column of the first image G11, and measures the width of the white part as the width of the slit K. In the first image G11, the width of the white part measured by the first measurement unit 91, that is, the width of the slit K, is, for example, the first measurement width Lb of 3 pixels. It can be speculated that this is because, for example, as Figure 8 shown, the slit K is formed obliquely from the front surface Wa to the back surface Wb of the workpiece W, that is, the slit K is not formed normally and more illumination light of the lower illumination 302 is blocked by the workpiece W. Next, Figure 1 the first determination unit 92 shown determines that the first measurement width Lb measured by the first measurement unit 91 is less than the preset first width L1, and thus determines that the slit K is not formed normally and is defective.

[0095] In the case of this embodiment Figure 1 、Figure 2 When the upper surface, i.e., the front surface Wa, of the workpiece W shown is sealed by the resin layer J and the resin layer J is divided by irradiation with laser light as described above, as Figure 10 shown, sometimes the resin layer J may pour toward the slit K due to the heat generated by laser ablation processing. As a result, the illumination light of the lower illumination 302 is more blocked by the resin layer J that has poured toward the slit K. In addition, this phenomenon does not occur when the front surface Wa of the workpiece W is not covered by the resin layer J.

[0096] For example, the first image captured by the imaging unit 8 is Figure 9 the first image G12 shown. The first measurement unit 91 calculates the number of pixels displayed in white for each column of the first image G12 and measures the width of the white portion as the width of the slit K.

[0097] Since the resin layer J pours toward the slit K, the actual shape of the upper surface of the slit K becomes a curved shape that bends somewhere. In the binarized first image G12, the slit K is displayed in a shape where the pixels representing the poured resin layer J fly out in the Y-axis direction. That is, in the first image G12, for example, the luminance value of the pixel B11 at the first column from the -X direction and the fifth row from the -Y direction is less than the specified threshold value described above, and in the first image G12, it is only displayed in black in the actual first image G12. On the other hand, for example, the luminance value of the pixel B12 at the first column from the -X direction and the tenth row from the -Y direction is greater than the specified threshold value described above, and in the first image G12, it is actually only displayed in white.

[0098] Therefore, the first measurement unit 91 counts the number of pixels displayed in white in the first column of the first image G12 as 5 (5 pixels from the sixth row to the tenth row from the -Y direction), for example. When the value of one side of a pixel is 10 μm, the width of the slit K, which is the width of the white portion in the first column, is measured as 5 pixel μm (50 μm). And the first determination unit 92 determines that the width of the slit K in the first column is equal to or greater than the preset first width L1 and equal to or less than the second width L2.

[0099] On the other hand, in the first image G12, for example, the luminance values of the pixels B13, B14, B15, and B16 in the 5th and 6th columns starting from the -X direction and the 6th and 10th rows starting from the -Y direction are less than the specified threshold value described above, and in the first image G12, they are actually displayed only in black. Therefore, the first measurement unit 91 counts, for example, the number of pixels displayed in white in the 5th and 6th columns starting from the -X direction in the first image G12 as 3, and measures the width of the white part as the width of the slit K to be 3 pixel μm (30 μm). And the first determination unit 92 determines that the width of the slit K in the 5th and 6th columns is less than the preset first width L1.

[0100] In this way, after measuring the width of the slit K for each column based on the first measurement unit 91 and determining whether the width of the slit K for each column is equal to or greater than the first width L1 and equal to or less than the second width L2 for all columns using the first image G12, the first determination unit 92 calculates the number of columns in which the width of the slit K is equal to or greater than the first width L1 and equal to or less than the second width L2, and calculates the ratio in all columns of the first image G12. The first determination unit 92 compares, for example, the determination value of what ratio or more the ratio pre-stored in the first storage unit 90 should be in order to determine that the slit K in the first image G12 is formed normally and the calculated ratio. As a result, the first determination unit 92, for example, determines that Figure 9 the slit K shown in the first image G12 shown is not formed normally and is defective. That is, as Figure 10 shown, for example, it is determined that the resin layer J pours toward the slit K side and the slit K is defective.

[0101] For example Figure 1 shown, when the first determination unit 92 determines that the slit K is defective as in the slit K shown in Figure 7 or Figure 9 shown, the first determination unit 92 can issue an alarm or warning indicating that the dividing and processing apparatus 1 cannot perform normal dividing and processing on the workpiece W. In this case, the operator who receives the alarm or warning checks the dividing and processing apparatus 1, grasps the main cause of the defect of the slit K, and can improve the dividing and processing apparatus 1.

[0102] (2) Judgment method 2 for normality or defectiveness of the slit based on the first determination unit 92

[0103] The judgment of the normality or defectiveness of the slit K based on the first determination unit 92 can be performed by the judgment method 2 described below instead of the judgment method 1.

[0104] For example, the width Sa of the interval track S, the first width L1, and the second width L2 are displayed on the first image G1 shown in Figure 5 shown.

[0105] For example, the first measurement unit 91 counts the number of pixels of the white portion representing the slit K in the first image G1, calculates the total thereof, and uses it as the total area S1 of the slit K in the first image G1. In addition, the first measurement unit 91 counts the number of pixels of the black portion in the first image G1, calculates the total thereof, and uses it as the total area S2 of the black portion.

[0106] In addition, the first measurement unit 91 measures the width of the white portion, that is, the first measurement width La of the slit K, based on the area ratio between the total area S1 of the white portion and the total area S2 of the black portion in the first image G1. The first determination unit 92 determines that the first measurement width La measured by the first measurement unit 91 is equal to or greater than the preset first width L1 and equal to or less than the second width L2, and thus determines that the slit K is formed normally.

[0107] For example, the first image captured by the imaging unit 8 is Figure 7 the first image G11 shown. The first measurement unit 91 counts the number of pixels of the white portion representing the slit K in the first image G11, calculates the total thereof, and uses it as the total area S3 of the slit K in the first image G11. In addition, the first measurement unit 91 counts the number of pixels of the black portion in the first image G11, calculates the total thereof, and uses it as the total area S4 of the black portion. In addition, the first measurement unit 91 measures the first measurement width Lb of the slit K based on the area ratio between the total area S3 of the white portion and the total area S4 of the black portion in the first image G11. The first determination unit 92 determines that the measured first measurement width Lb is less than the preset first width L1, and thus determines that the slit K is not formed normally and is defective.

[0108] The dividing and processing apparatus 1 according to the present embodiment can determine whether the slit K is normal or defective, that is, whether the slit K has an appropriate width that penetrates the upper and lower surfaces of the workpiece W, in the above-described determination method 1 or determination method 2, and can also determine whether the slit K is formed vertically or obliquely from the front surface Wa, which is the upper surface of the workpiece W, toward the back surface Wb, which is the lower surface.

[0109] To make this determination, the imaging unit 8 shown Figure 11 captures an image of the slit K formed on the upper surface, that is, the front surface Wa, of the workpiece W. That is, for example, in a state where the focus of the imaging unit 8 is focused on the front surface Wa of the workpiece W and the center line of the dividing channel S (the dividing channel S when the first image is captured) is positioned directly below the optical axis of the imaging unit 8, and with the lower illumination 302 turned off, the upper illumination 82 is turned on and irradiates illumination light toward the workpiece W.

[0110] In this embodiment, the coaxial epi-illumination 820 irradiates the front surface Wa of the workpiece W from directly above via the semi-reflective mirror 822, and the oblique light illumination 821 irradiates the front surface Wa of the workpiece W from obliquely above. However, the illumination of the oblique light illumination 821 is set stronger than that of the coaxial epi-illumination 820. That is, for example, the oblique light illumination 821 along the Figure 11 shown X-axis direction is set stronger. As a result, the reflected light from the front surface Wa of the workpiece W is received by the imaging unit 83 via the objective lens 823, and a captured image showing the upper surface of the slit K is formed. That is, the slit K is photographed from above the workpiece W to form the Figure 12 shown second image G2 in which the slit K is photographed as a relatively dark black portion.

[0111] This second image G2 is stored in the Figure 1 second storage unit 93 formed of a storage element or the like in the control unit 9 shown.

[0112] For example, the first image captured by the imaging unit 8 is the Figure 7 shown first image G11. Next, the case of capturing the Figure 12 shown second image G2 will be described.

[0113] For example, the second image G2 stored in the second storage unit 93 is subjected to binarization processing in which a portion where the luminance value of one pixel is equal to or greater than a specified threshold is made white, and a portion where the luminance value of one pixel is less than the specified threshold is made black. Then, for example, as Figure 13 shown, the binarized second image G2 is displayed in parallel with the first image G11 displayed on the output screen B.

[0114] As Figure 1 shown, the control unit 9 has, for example, a second measurement unit 94. The second measurement unit 94 counts the number of pixels of the black portion in the second image G2 in a direction (Y-axis direction) perpendicular to the extending direction (X-axis direction) of the pitch channel S in the second image G2 displayed on the output screen B, and measures the width of the black portion as the width of the slit K on the upper surface, that is, the front surface Wa, of the workpiece W.

[0115] The second measurement unit 94 measures the width of the slit K on the upper surface, that is, the front surface Wa, of the workpiece W as the width La. Additionally, the midpoint of the appropriate width La is located on the center line of the pitch channel S.

[0116] As Figure 1As shown, the control unit 9 has a second determination unit 95. The second determination unit 95 determines whether the slit K is formed vertically from the upper surface (front surface Wa) of the workpiece W toward the lower surface (back surface Wb) or obliquely, based on the measurement results measured by the first measurement unit 91 and the measurement results measured by the second measurement unit 94.

[0117] Based on the second image G2 shown, on the front surface Wa which is the upper surface of the workpiece W, the slit K is formed with an appropriate width La (a width La of 6 pixels) and its center line coincides with the center line of the interval path S. Therefore, it is determined that on the front surface Wa of the workpiece W, the upper surface of the slit K is normally formed at the correct position with the correct width. Figure 13 As shown, the second determination unit 95 determines that on the front surface Wa which is the upper surface of the workpiece W, the slit K is formed with an appropriate width La (a width La of 6 pixels) and its center line coincides with the center line of the interval path S. Therefore, it is determined that on the front surface Wa of the workpiece W, the upper surface of the slit K is normally formed at the correct position with the correct width.

[0118] In addition, based on the second image G2 shown, the second determination unit 95 determines that the interval path S and the center line are the same. With respect to the upper surface of the slit K with a width La of 6 pixels, the slit K with a first measured width Lb of 3 pixels shown in the first image G11 appears on the -Y direction side with the center line of the interval path S in between. It is determined that the slit K is formed obliquely toward the +Y direction side from the front surface Wa which is the upper surface of the workpiece W toward the back surface Wb which is the lower surface, and is not formed vertically. Figure 13 As shown, the second determination unit 95 determines that the interval path S and the center line are the same. With respect to the upper surface of the slit K with a width La of 6 pixels, the slit K with a first measured width Lb of 3 pixels shown in the first image G11 appears on the -Y direction side with the center line of the interval path S in between. It is determined that the slit K is formed obliquely toward the +Y direction side from the front surface Wa which is the upper surface of the workpiece W toward the back surface Wb which is the lower surface, and is not formed vertically. Figure 14 As shown, it is determined that the slit K is formed obliquely toward the +Y direction side from the front surface Wa which is the upper surface of the workpiece W toward the back surface Wb which is the lower surface, and is not formed vertically.

[0119] The control unit 9 of the dividing and processing device 1 of the present embodiment has Figure 1 a third determination unit 96 shown. When it is determined by the second determination unit 95 as described above that the slit K is formed obliquely, the third determination unit 96 determines whether the upper surface and the lower surface of the slit K can be included within the width of the interval path S even according to the inclination of the slit K shown. Figure 14 As shown, when it is determined by the second determination unit 95 as described above that the slit K is formed obliquely, the third determination unit 96 determines whether the upper surface and the lower surface of the slit K can be included within the width of the interval path S even according to the inclination of the slit K shown.

[0120] The third determination unit 96 first determines whether the lower surface of the slit K enters the width Sa of the interval path S. That is, as shown, it is determined that the lower surface of the slit K does not enter the width Sa of the interval path S. Next, the third determination unit 96 calculates the protruding distance Ly1 of the lower surface of the slit K from within the width Sa of the interval path S. When the protruding distance Ly1 is less than or equal to the distance Ly2 (the distance from the one end side in the Y-axis direction of the upper surface of the slit K to the one end side in the Y-axis direction of the interval path S), it is determined that the upper surface and the lower surface of the slit K can enter the width Sa of the interval path S, and thus stores the correction amount in the Y-axis direction (indexing feed direction) when performing the dividing and processing on the workpiece W. This correction amount is a desired distance Ly3 that is greater than or equal to the protruding distance Ly1 and less than or equal to the distance Ly2 from the one end side in the Y-axis direction to the one end side in the Y-axis direction of the interval path S (refer to Figure 14 As shown, it is determined that the lower surface of the slit K does not enter the width Sa of the interval path S. Next, the third determination unit 96 calculates the protruding distance Ly1 of the lower surface of the slit K from within the width Sa of the interval path S. When the protruding distance Ly1 is less than or equal to the distance Ly2 (the distance from the one end side in the Y-axis direction of the upper surface of the slit K to the one end side in the Y-axis direction of the interval path S), it is determined that the upper surface and the lower surface of the slit K can enter the width Sa of the interval path S, and thus stores the correction amount in the Y-axis direction (indexing feed direction) when performing the dividing and processing on the workpiece W. This correction amount is a desired distance Ly3 that is greater than or equal to the protruding distance Ly1 and less than or equal to the distance Ly2 from the one end side in the Y-axis direction to the one end side in the Y-axis direction of the interval path S (refer to Figure 15 )

[0121] On the other hand, when the protruding distance Ly1 exceeds the distance Ly2, it is determined that the upper surface and the lower surface of the slit K cannot enter the width Sa of the inter-track S. In this case, the third determination unit 96 can issue an alarm or a warning indicating that the dividing and processing device 1 cannot perform normal dividing and processing on the workpiece W.

[0122] As described above, after determining whether the slit K in the peripheral remaining area of the workpiece W is normal or defective, the workpiece W is divided into chips by performing dividing and processing on the workpiece W as follows.

[0123] Since the coordinate position of the inter-track S of the workpiece W has been grasped by the previous alignment, Figure 1 the chuck table 30 shown in the figure is moved in the Y-axis direction to align the inter-track S with the irradiation head 609 of the dividing unit 60. This alignment is performed, for example, in such a way that the center line of the inter-track S is positioned directly below the condensing point of the irradiation head 609. After this alignment, the chuck table 30 is further moved in the +Y direction to a position offset by the correction amount calculated previously, that is, Figure 15 the distance Ly3 shown in the figure, by Y-axis control, so that the upper surface and the lower surface of the slit K to be formed enter the width Sa of the inter-track S.

[0124] Next, the position of the condensing point of the laser beam converged by the condenser lens 609a is aligned with a specified height position in the thickness direction of the workpiece W (for example, the height position of the front surface Wa of the workpiece W). And, Figure 1 the laser oscillator 601 shown in the figure oscillates a laser beam having a wavelength that is absorbable by the workpiece W, converges the laser beam from the front surface Wa side, and irradiates the workpiece W. In addition, the workpiece W is fed in the -X direction, which is the forward direction, at a specified processing feed rate, and the laser beam is irradiated along the inter-track S onto the workpiece W, thereby ablating the resin layer J and the workpiece W, and completely cutting the workpiece W along the inter-track S through the slit K. In addition, the upper surface and the lower surface of the formed slit K Figure 15 enter the width Sa of the inter-track S as shown in the figure.

[0125] When the workpiece W travels in the -X direction to the specified position where the laser beam irradiation along the inter-track S ends, the irradiation of the laser beam is stopped, and the chuck table 30 is moved in the Y-axis direction. Together with the Y-axis movement correction of the amount of the distance Ly3, the inter-track S located next to the reference inter-track S during the laser beam irradiation during the processing feed in the -X direction is Figure 1Alignment of the irradiation head 609 in the Y-axis direction as shown. The workpiece W is fed for machining in the +X direction as the return direction. Similar to the irradiation of the laser beam in the forward direction, the workpiece W is completely cut along the spaced track S through the slit K. After performing the same laser beam irradiation along all the spaced tracks S extending in the X-axis direction in sequence, when the chuck table 30 is rotated by 90 degrees and the same laser beam irradiation is performed, the workpiece W can be completely cut into individual chips.

[0126] As described above, regarding the dicing apparatus 1 of the present invention, the chuck table 30 has: a plate-shaped transparent plate 300 made of a transparent member, having a suction port that communicates the upper surface with a suction source so that the upper surface functions as a holding surface 300a; a base 301 that supports the transparent plate 300; and a lower illumination 302 disposed between the transparent plate 300 and the base 301 to illuminate the holding surface 300a. The dicing apparatus 1 has: a first storage unit 90 that stores a first image, which is composed of a white portion that appears white due to the light of the lower illumination 302 passing through and a black portion that appears black due to the light of the lower illumination 302 being blocked by the workpiece W when the lower illumination 302 is lit and the slit K of the workpiece W held on the holding surface 300a by the dicing unit 60, for example, formed in the outer peripheral remaining area, is photographed by the photographing unit 8; a white pixel detection unit 98 that detects whether there are pixels of the white portion in the first image in a direction perpendicular to the extending direction of the spaced track S; and a determination unit 97 that determines that the slit K is defective when the white pixel detection unit 98 fails to detect white pixels, and determines that the slit K is formed normally when the white pixel detection unit 98 can detect white pixels, so that it is possible to confirm whether the slit K formed in the workpiece W penetrates the upper and lower surfaces of the workpiece W while the workpiece W is held on the chuck table 30. Then, dicing processing is performed on the workpiece W along the spaced track S, thereby preventing the occurrence of defective dicing processing.

[0127] The dividing and processing apparatus 1 includes: a first measuring unit 91 that measures the width of the white portion of the first image by counting the number of pixels of the white portion in a direction perpendicular to the extending direction of the interval path S; and a first determination unit 92 that determines that the slit K is defective when the first measured width measured by the first measuring unit 91 is less than a preset first width L1, and determines that the slit K is defective when the first measured width exceeds a preset second width L2, and determines that the slit K is formed normally when the first measured width is equal to or greater than the preset first width L1 and equal to or less than the preset second width L2. Thus, it is possible to confirm whether the slit K formed in, for example, the outer peripheral remaining region of the workpiece W penetrates the upper and lower surfaces of the workpiece W while the workpiece W is held on the chuck table 30, and it is possible to confirm whether the slit K is formed with an appropriate width. Using the result of this determination, an appropriate dividing and processing can be performed on the workpiece W thereafter.

[0128] In addition, the dividing and processing apparatus 1 of the present invention includes: an upper illumination 82 that illuminates the workpiece W from above the workpiece W held by the chuck table 30; a second storage unit 93 that stores a second image, which is an image of the slit K taken as a black portion that appears darker when the upper illumination 82 is turned on and the lower illumination 302 is turned off and the slit K is photographed from above the workpiece W by the photographing unit 8; a second measuring unit 94 that counts the number of pixels of the black portion of the second image in a direction perpendicular to the extending direction of the interval path S and measures the width of the slit K on the upper surface of the workpiece W; and a second determination unit 95 that determines whether the slit K is formed vertically or obliquely from the upper surface of the workpiece W toward the lower surface based on the measurement results measured by the first measuring unit 91 and the second measuring unit 94. Thus, it is possible to confirm in advance whether the slit K is formed vertically from the upper surface (front surface Wa) of the workpiece W toward the lower surface (back surface Wb) while the workpiece W is held on the chuck table 30, for example, before actually performing the process of dividing the workpiece W into chips.

[0129] The dividing and processing apparatus 1 includes a third determination unit 96. When the second determination unit 95 determines that the slit K is formed obliquely, the third determination unit 96 determines whether it is possible to include the upper and lower surfaces of the slit K within the width Sa of the interval path S even according to the inclination of the slit K. When the third determination unit 96 determines that the upper and lower surfaces of the slit K can enter the width of the interval path S, the following Y-axis control is performed: the chuck table 30 and the dividing unit 60 are relatively moved in the Y-axis direction so that the upper and lower surfaces of the slit K enter the width of the interval path S, so that it is possible to cause the upper and lower surfaces of the slit K to enter the width Sa of the interval path S with respect to the workpiece W held by the chuck table 30 and perform processing by the dividing unit 60.

[0130] The dividing and processing device 1 of the present invention is not limited to the above-described embodiments, and of course, various different methods can be used for implementation within the scope of its technical idea. For example, the dividing unit 60 is not limited to the above-described laser processing unit, and may also be a cutting unit having a spindle on which an annular cutting tool in which abrasive grains are fixed using a bonding material is mounted. In addition, regarding the shape and the like of each structure of the dividing and processing device 1 shown in the drawings, it is not limited thereto, and appropriate changes can be made within the range where the effects of the present invention can be exhibited.

Claims

1. A dicing and processing apparatus, comprising: A chuck table having a holding surface for holding a workpiece having devices formed in regions divided by streets; A dicing unit that forms a slit along the streets of the workpiece held by the chuck table and slices the workpiece into small pieces for each device; An X-axis feed unit that relatively feeds the chuck table and the dicing unit in the X-axis direction parallel to the extending direction of the streets; A Y-axis feed unit that relatively rotates and feeds the chuck table and the dicing unit along the Y-axis direction perpendicular to the X-axis direction on a horizontal plane; and An imaging unit that images the slit from above the workpiece held by the chuck table, The chuck table includes: A plate-shaped transparent plate made of a transparent member, having suction ports that communicate the upper surface with a suction source in such a way that the upper surface functions as a holding surface; A base that supports the transparent plate; and A bottom illumination disposed between the transparent plate and the base for illuminating the holding surface, The dicing and processing apparatus includes: A first storage unit that stores a first image, which is composed of a white portion that appears white due to the light of the bottom illumination passing through and a black portion that appears black due to the light of the bottom illumination being blocked by the workpiece when the bottom illumination is lit and the imaging unit images the slit of the workpiece having the slit formed by the dicing unit held on the holding surface; A white pixel detection unit that detects whether there are pixels of a white portion in the first image in a direction perpendicular to the extending direction of the streets; And A determination unit that determines that the slit is defective when the white pixel detection unit fails to detect white pixels, and determines that the slit is formed normally when the white pixel detection unit can detect white pixels, The dicing and processing apparatus includes: A first measurement unit that counts the number of pixels of the white portion of the first image in a direction perpendicular to the extending direction of the streets and measures the width of the white portion; and A first determination unit that determines that the slit is defective when the first measurement width measured by the first measurement unit is less than a preset first width, and determines that the slit is defective when the first measurement width exceeds a preset second width, and determines that the slit is formed normally when the first measurement width is equal to or greater than the preset first width and less than the preset second width, The dicing and processing apparatus includes: An upper illumination that illuminates the workpiece from above the workpiece held by the chuck table; A second storage unit that stores a second image, which is taken as a black portion where the slit appears black when the upper illumination is lit and the bottom illumination is turned off and the imaging unit images the slit from above the workpiece; A second measurement unit that counts the number of pixels of the black portion of the second image in a direction perpendicular to the extending direction of the streets and measures the width of the slit on the upper surface of the workpiece; And A second determination unit that determines whether the slit is formed vertically from the upper surface to the lower surface of the workpiece or obliquely based on the measurement result measured by the first measurement unit and the measurement result measured by the second measurement unit.

2. The dividing and processing apparatus according to claim 1, wherein the dividing and processing apparatus includes a third determination unit that, when it is determined by the second determination unit that the slit is formed obliquely, determines whether it is possible to include the upper surface and the lower surface of the slit within the width of the inter-channel, when the third determination unit determines that it is possible to include the upper surface and the lower surface of the slit within the width of the inter-channel, the following Y-axis control is performed: the chuck table and the dividing unit are relatively moved in the Y-axis direction so that the upper surface and the lower surface of the slit enter within the width of the inter-channel.

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