JP2018117094A - Processing equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently focus on a surface of a wafer even when the actual thickness of the plate-shaped work is different from the thickness registered in the apparatus in advance or when the thickness of the plate-shaped work is unknown. SOLUTION: When the image pickup means 33 is lowered at a constant speed and the focus of the captured image is aligned with the surface Wa of the plate-shaped work W, the control of the lowering of the image pickup means 33 is stopped and the surface Wa is focused. The position of the image pickup means 33 that actually stopped descending below the position of is set as the first position Z1, the image pickup means 33 is raised at the constant speed, and the focal point of the image taken is on the surface Wa of the plate-shaped work W. When the alignment is met, the control of the ascending of the imaging means is stopped, and the position of the imaging means 33 in which the ascending is actually stopped above the position when the surface Wa is in focus is set as the second position Z2, and the first position is set. By locating the image pickup means 33 at the intermediate position Z3 between Z1 and the second position Z2 and performing image pickup, the focus is focused on the surface Wa of the plate-shaped work W. [Selection diagram] Fig. 3

Description

  The present invention relates to a processing apparatus having a function of detecting a position to be processed by focusing on the surface of a plate-like workpiece by autofocus.

  When a plate-like workpiece such as a semiconductor wafer is divided and processed, the surface of the plate-like workpiece is imaged by an imaging means, and a position to be machined is detected by image processing such as pattern matching. The auto-focus function is used to image the surface of the plate-like workpiece, and the imaging means is stepped in the thickness direction of the plate-like workpiece with a resolution of, for example, 2 μm, and the image is differentiated for each step feed. Image processing such as processing is performed.

  However, if the distance to be autofocused is long, the number of step feeds, imaging and image processing increases, and a long time is required. For example, when auto-focusing is performed in the range of a distance of about 2 to 3 mm, for example, when the resolution is 2 μm, step feed of 1000 to 1500 times, imaging and image processing are necessary, and at least about 20 seconds are spent. It was.

  Therefore, the numerical value of the thickness of the plate-like workpiece is registered in advance in the apparatus, the focal position is moved to the vicinity of the surface of the plate-like workpiece in consideration of the thickness value, and then step feed is performed. A technique for shortening the time required for autofocus by performing imaging has been proposed (see, for example, Patent Document 1). Since the thickness variation of the plate-like workpiece is usually about 50 μm, in the technique described in Patent Document 1, when the maximum value of the thickness variation is 50 μm, for example, the resolution is 2 μm, the number of step feeds, imaging, and image processing Is about 25 times, and the time required for autofocus can be shortened.

Japanese Patent Laid-Open No. 08-97271

  However, if an incorrect value is registered in the apparatus as the thickness of the plate workpiece, and a difference in thickness occurs between the plate workpiece registered in the apparatus and the plate workpiece that is actually imaged and processed. , Autofocus will take extra time. In addition, when the thickness of the plate-like workpiece is unknown, the thickness value cannot be registered in the apparatus, and therefore it is impossible to reduce the autofocus time.

  The present invention has been considered in view of such problems, even when the actual thickness of the plate workpiece is different from the thickness registered in the apparatus in advance, or even when the thickness of the plate workpiece is unknown, It is an object to focus on the surface of the wafer efficiently.

  The present invention captures the surface of the plate-like work held by the holding means from above, holding means for holding the surface of the plate-like work defined on the surface by dividing lines and having devices formed thereon, and the surface of the plate-like work held by the holding means. Imaging means, lifting and lowering means for lowering and raising the imaging means relative to the holding means, processing means for processing the plate-like workpiece held by the holding means along the planned division line, at least the imaging means and the A control device for controlling the lifting means, wherein the control means focuses the imaging means for picking up an image of a plate-like workpiece when the lifting means lowers the imaging means at a constant speed. The position of the image pickup means when the position of the imaging means is lower than the lower surface of the plate-like workpiece and lower than the upper surface of the plate-like workpiece, or less than the upper position of the plate-like workpiece, is defined as the first position. When the first storage unit for storing and the elevating means raise the imaging means at the constant speed, the focal point of the imaging means for imaging the plate-like workpiece rises from below the surface of the plate-like workpiece. A second storage section for storing the position of the imaging means as a second position when the position is located above or below the position where the plate-shaped workpiece is over-exceeded, or the first position, A calculation unit that calculates an intermediate position between the first position stored in the storage unit and the second position stored in the second storage unit, and the intermediate position calculated by the calculation unit is The focus of the imaging means is set to a position that matches the surface of the plate-like workpiece.

  In the present invention, the lowering control is stopped when the imaging means is lowered and the surface of the plate-like workpiece is focused, and the lowering of the imaging means that actually stops lowering below the position when the focusing is achieved. The position is set to the first position, the imaging means is raised, and the raising control is stopped when the surface of the plate-like workpiece is focused, and the raising is actually stopped above the position when the focused. The position of the image pickup means is the second position, and the intermediate position between the first position and the second position is the position where the focus of the image pickup means matches the surface of the wafer. It is possible to cancel the time lag from when the focus is achieved until when the raising / lowering of the imaging unit actually stops. Therefore, it is not necessary to step up and down the imaging means with fine resolution, and it is not necessary to grasp the thickness of the wafer, so that the surface of the wafer can be focused efficiently.

It is a perspective view which shows an example of a processing apparatus. It is a front view which shows typically the structure of an imaging means, an raising / lowering means, and a control means. It is a front view which shows typically the procedure which matches the focus of an imaging means with the surface of a wafer. It is a front view which shows typically another example of the procedure which matches the focus of an imaging means with the surface of a wafer.

  A cutting apparatus 1 shown in FIG. 1 is an example of a processing apparatus to which the present invention is applied, and is an apparatus for cutting a wafer W, which is a plate-like work held by a holding means 7, by cutting means 3a and 3b.

  The holding unit 7 includes a suction unit 70 that sucks and holds the wafer W and a frame 71 that surrounds the suction unit 70. The suction unit 70 communicates with a suction source (not shown). The holding surface 700 which is the upper surface of the adsorption part 70 and the upper surface of the frame 71 are formed flush with each other.

  On the surface Wa of the wafer W, a device D is formed in an area partitioned by the division lines L. On the other hand, a dicing tape T is attached to the back surface Wb of the wafer W. A ring-shaped frame F is attached to the periphery of the dicing tape T, and the wafer W is supported by the frame F via the dicing tape T. In the suction portion 70 of the holding means 7, the back surface Wb side of the wafer W is held by sucking and holding the dicing tape T by applying a suction force from a suction source to the holding surface 700.

  A plurality of clamp portions 6 (four in the illustrated example) for fixing the frame F are arranged on the outer peripheral side of the holding means 7, and the frame F that supports the wafer W sucked and held on the holding surface 700 is provided. It is fixed by the clamp part 6.

  The holding means 7 and the clamp part 6 are sent in the X-axis direction by the cutting feed means 2. The cutting feed means 2 is screwed into the ball screw 20 extending in the X-axis direction, a pair of guide rails 21 arranged parallel to the ball screw 20, a motor 22 connected to one end of the ball screw 20, and the ball screw 20. A moving base 24 having a bottom that is in sliding contact with the guide rail 21, and the motor 22 rotates the ball screw 20, whereby the moving base 24 is guided by the guide rail 21 and the X axis Move in the direction. The holding means 7 and the rotating means 23 for rotating the clamp portion 6 are provided above the moving base 24, and the holding means 7 and the moving base 24 move in the X-axis direction as the moving base 24 moves in the X-axis direction. To do.

  The cutting means 3a and 3b include a rotatable cutting blade 30, a spindle (not shown) having a Y axis axial center, a housing 31 for rotatably supporting the spindle, and the cutting blade 30. And a cutting water nozzle 32 for supplying cutting water to the nozzle. The cutting blade 30 constituting the cutting means 3a and the cutting blade (not shown) constituting the cutting means 3b face each other in the Y-axis direction.

  On the side of the housing 31, an imaging unit 33 that images the surface Wa of the plate-like workpiece held by the holding unit 7 is disposed. As shown in FIG. 2, the imaging means 33 is driven by the lifting / lowering means 34 and can be lifted / lowered. The lifting / lowering means 34 is screwed into the ball screw 340 and supports the imaging means 33 while the ball screw 340 having an axis in the Z-axis direction, the motor 341 that rotates the ball screw 340, the encoder 342 that recognizes the rotation angle of the motor And the image pickup means 33 supported by the support part 343 and the support part 343 can be raised or lowered by rotating the ball screw 340 forward or backward.

  The motor 341 and the encoder 342 are connected to the control means 8. The encoder 342 can recognize the height position of the imaging means 33 in the Z-axis direction through the number of rotations of the motor 341, and the control means 8 rotates the motor 341 based on information from the encoder 342 to take an image. The height position of the means 33 in the Z-axis direction can be controlled.

  The cutting means 3a and 3b shown in FIG. 1 are each driven by the cutting feed means 5 and can move in the Z-axis direction. The cutting feed means 5 is screwed into the ball screw 50 extending in the Z-axis direction, a pair of guide rails 51 arranged in parallel to the ball screw 50, a motor 52 connected to one end of the ball screw 50, and the ball screw 50. And an elevating base 53 whose side part is in sliding contact with the guide rail 51, and the motor 52 rotates the ball screw 50 so that the elevating base 53 is guided by the guide rail 51. Move in the axial direction. Cutting means 3a and 3b are fixed to the lower part of the elevating base 53. As the elevating base 53 moves in the Z-axis direction, the cutting means 3a and 3b also move in the Z-axis direction.

  The cutting means 3a and the cutting feed means 5 for moving the cutting means 3a in the Z-axis direction and the cutting feed means 5 for moving the cutting means 3b and the cutting means 3b in the Z-axis direction are driven by the index feeding means 4, respectively. Move in the Y-axis direction. The index feed means 4 is screwed into the ball screw 40 extending in the Y-axis direction, a pair of guide rails 41 arranged in parallel to the ball screw 40, a motor 42 connected to one end of the ball screw 40, and the ball screw 40. The moving base 43 is configured to be guided by the guide rail 41 when the motor 42 rotates the ball screw 40. Move in the axial direction. The side of the moving base 43 is provided with a cutting feed means 5, and the cutting feed means 5 and the cutting means 3a, 3b move in the Y axis direction as the movement base 43 moves in the Y axis direction.

  As shown in FIG. 2, the control unit 8 includes at least a CPU and a memory, and when the imaging unit 33 is lowered, the imaging unit 33 immediately after the image captured by the imaging unit 33 is in focus. The first storage unit 81 for storing the position in the Z-axis direction and the Z-axis direction of the imaging unit 33 immediately after the image captured by the imaging unit 33 is focused when the imaging unit 33 is raised A second storage unit 82 that stores the position, a calculation unit 83 that calculates an intermediate position between the position stored in the first storage unit 81 and the position stored in the second storage unit 82, and the imaging unit 33. An image processing unit 84 that performs processing such as pattern matching between a captured image and a previously stored image is provided.

  Hereinafter, the operation of the cutting apparatus 1 when the cutting blade 30 is cut along the division line L of the wafer W shown in FIG. 1 and the wafer W is divided into chips for each device D will be described.

  First, the cutting feed means 2 moves the holding means 7 in the −X direction to move the wafer W held by the holding means 7 below the imaging means 33. Then, in order to detect the division line L to be cut and align the position of the cutting blade 30 in the Y-axis direction with the division line L, the elevating means 34 shown in FIG. By moving in the axial direction, the imaging means 33 is focused on the wafer W to perform imaging. Such imaging is performed using the two imaging means 33. Since the two imaging means 33 perform the same operation, only the operation of one imaging means 33 will be described below.

  Normally, as shown in FIG. 3A, in order to adjust the focal point 33a of the imaging means 33 to the surface Wa of the wafer W, the position of the imaging means 33 in the Z-axis direction is roughly adjusted, and then the lifting / lowering means 34 takes an image. The means 33 is gradually lowered, for example, with a resolution of 2 μm. In this method, the thickness of the wafer W is stored in the control means 8 in advance for rough alignment of the imaging means 33 in the Z-axis direction. In addition, when the value of the thickness of the wafer W is erroneously stored or the thickness of the wafer W is unknown, such a method cannot be adopted. Therefore, the focal position of the imaging means 33 is obtained as follows.

(1) How to find the focal position 1
The raising / lowering means 34 first raises the imaging means 33 so that the focal point of the imaging means 33 is positioned above the surface Wa of the wafer W as indicated by a two-dot chain line in FIG. Then, from this state, the control means 8 drives the motor 341 of the elevating means 34 to lower the imaging means 33 in the −Z direction at a constant speed. While the image pickup means 33 is descending, the image picked up by the image pickup means 33 is transferred to the image processing unit 84 shown in FIG. 2 and stored. Immediately thereafter, the position of the imaging means 33 in the Z-axis direction is stored in the control means 8 based on the information from the encoder 342 at that time. Next, the image processing unit 84 sequentially determines whether or not the stored image is in focus. When the image processing unit 84 determines that the imaging unit 33 is focused on the surface Wa of the wafer W by repeating the processing in this order, the control unit 70 immediately stops the motor 341 constituting the elevating unit 34 and performs imaging. The descending of the means 33 is stopped. Further, the first storage unit 81 stores the position of the imaging unit 33 stored in the control unit 8 in the Z-axis direction.

  Since there is a certain time lag until the position of the imaging means 33 in the Z-axis direction is stored in the control means 8 after imaging at a position where the focal point of the imaging means 33 matches the surface Wa of the wafer W, FIG. ), The focal point 33b of the imaging means 33 at the position stored in the first storage unit 81 is at a position that is excessively below the surface Wa of the wafer W (−Z direction).

  Next, the raising / lowering means 34 lowers the imaging means 33 so that the focal point of the imaging means 33 is positioned below the surface Wa of the wafer W as indicated by a two-dot chain line in FIG. Then, from this state, the control means 8 drives the motor 341 of the elevating means 34 to raise the imaging means 33 in the + Z direction at a constant speed. This constant speed is the same speed as the speed when the imaging means 33 shown in FIG. 3B is lowered, and the direction of movement is the opposite direction. While the imaging unit 33 is moving up, the image captured by the imaging unit 33 is transferred to the image processing unit 84 shown in FIG. 2 and stored. Immediately thereafter, the position of the imaging means 33 in the Z-axis direction is stored in the control means 8 based on the information from the encoder 342 at that time. Next, the image processing unit 84 sequentially determines whether or not the stored image is in focus. When the image processing unit 84 determines that the imaging unit 33 is focused on the surface Wa of the wafer W by repeating the processing in this order, the control unit 70 immediately stops the motor 341 constituting the elevating unit 34 and performs imaging. The raising of the means 33 is stopped. In addition, the position in the Z-axis direction of the imaging unit 33 that is finally stored in the control unit 8 is stored in the second storage unit 82.

  Since there is a certain time lag until the control unit 8 stores the position of the imaging unit 33 in the Z-axis direction after imaging at a position where the focal point of the imaging unit 33 matches the surface Wa of the wafer W, FIG. As shown in FIG. 5, the focal point 33c of the imaging means 33 at the position stored in the second storage unit 82 is at a position that has passed too far above the surface Wa of the wafer W (in the + Z direction).

  When the first position Z1 and the second position Z2 are thus stored in the first storage unit 81 and the second storage unit Z2, respectively, the calculation unit 83 shown in FIG. An intermediate position Z3 between the second position Z2 is calculated. In a state where the imaging unit 33 is located at the calculated intermediate position Z3, the imaging unit 33 is focused on the focal point 33a shown in FIG.

  Thus, when the imaging means 33 is lowered and the surface Wa of the plate-like workpiece W is focused, the lowering control is stopped, and the position of the imaging means 33 below the position when the focus is achieved is set. The first position Z1 is set, and when the imaging means 33 is raised and the surface Wa of the plate-like workpiece W is focused, the control of the lifting is stopped, and the imaging means 33 above the position when the focus is achieved. Is the second position Z2, and an intermediate position Z3 between the first position Z1 and the second position Z2 is a position where the focal point of the imaging unit 33 is aligned with the surface Wa of the wafer W. It is possible to cancel the time lag from when the first position Z1 and the second position Z2 are stored until the first position Z1 is aligned with the surface Wa. Therefore, it is not necessary to step up and down the image pickup means 33 with fine resolution, it is not necessary to grasp the thickness of the wafer W, and the surface Wa of the wafer W can be focused efficiently.

(2) Finding the focal position 2
In the above “Focus Position Determination Method 1”, in the process of lowering or raising the imaging unit 33, the imaging of the surface Wa and the determination as to whether or not the focal point has been made, and then the position of the imaging unit 33 in the Z-axis direction at that time However, after the position of the image pickup unit 33 in the Z-axis direction is recognized, it may be determined whether or not the surface Wa has been picked up and the focus is on. Also in this case, the lifting / lowering means 34 first raises the imaging means 33 so that the focal point of the imaging means 33 is located above the surface Wa of the wafer W as indicated by a two-dot chain line in FIG. Keep it. Then, from this state, the control means 8 drives the motor 341 of the elevating means 34 to lower the imaging means 33 in the −Z direction at a constant speed. While the imaging unit 33 is descending, the position of the imaging unit 33 in the Z-axis direction is sequentially stored in the control unit 8 based on information from the encoder 342. Further, immediately after storing the position of the imaging unit 33 in the Z-axis direction, the image captured by the imaging unit 33 is transferred to the image processing unit 84 shown in FIG. 2, and the image processing unit 84 transfers the transferred image information. Is stored, and the stored image is sequentially determined whether or not it is in focus. When such processing is repeated and the image processing unit 84 determines that the focus of the imaging means 33 is on the surface Wa of the wafer W, the control means 70 immediately stops the motor 341 constituting the elevating means 34 and the imaging means 33. Stops descending.

  Then, the position in the Z-axis direction of the imaging unit 33 that is finally stored in the control unit 8 is stored in the first storage unit 81 illustrated in FIG. 2 as the first position Z4. Since there is a certain time lag between the time when the first position Z4 is stored in the first storage unit 81 and the time when imaging is performed in a state in which the imaging means 33 is in focus with the surface Wa, FIG. ), The focal point 33d of the imaging means 33 located at the first position Z4 is in an inadequate position above the surface Wa of the wafer W (+ Z direction).

  Next, the raising / lowering means 34 lowers the imaging means 33 so that the focal point of the imaging means 33 is positioned below the surface Wa of the wafer W as indicated by a two-dot chain line in FIG. Then, from this state, the control means 8 drives the motor 341 of the elevating means 34 to raise the imaging means 33 in the + Z direction at a constant speed. This constant speed is the same speed as the speed when the imaging means 33 shown in FIG. 4B is lowered, and the direction of movement is the opposite direction. While the imaging unit 33 is moving up, the position of the imaging unit 33 in the Z-axis direction is sequentially stored in the control unit 8 based on information from the encoder 342. Further, immediately after storing the position of the imaging unit 33 in the Z-axis direction, the image captured by the imaging unit 33 is transferred to the image processing unit 84 shown in FIG. 2, and the image processing unit 84 transfers the transferred image information. Is stored, and the stored image is sequentially determined whether or not it is in focus. When such processing is repeated and the image processing unit 84 determines that the focus of the imaging means 33 is on the surface Wa of the wafer W, the control means 70 immediately stops the motor 341 constituting the elevating means 34 and the imaging means 33. Stop rising.

  Then, the position in the Z-axis direction of the image pickup means 33 stored in the control means 8 is stored in the second storage unit 82 shown in FIG. 2 as the second position Z5. Since there is a certain time lag between the time when the second position Z5 is stored in the second storage unit 82 and the time when imaging is performed in a state in which the imaging means 33 is in focus with the surface Wa, FIG. As shown in c), the focal point 33e of the image pickup means 33 located at the second position Z5 is in an inadequate position below the surface Wa of the wafer W (in the −Z direction).

  When the first position Z4 and the second position Z5 are stored in the first storage unit 81 and the second storage unit 82, respectively, the calculation unit 83 shown in FIG. The intermediate position Z3 with respect to the position Z5 of 2 is calculated. In a state where the imaging unit 33 is located at the calculated intermediate position Z3, the imaging unit 33 is focused on the focal point 33a shown in FIG.

  In this way, the position of the imaging means 33 positioned above the position when the imaging means 33 is lowered and focused on the surface Wa of the plate-like workpiece W is defined as the first position Z4, and the imaging means 33 The position of the imaging means 33 positioned below the position when the surface Wa of the plate-like workpiece W is focused is set as the second position Z5, and the first position Z4 and the second position The intermediate position Z3 with respect to Z5 is set to a position where the focal point of the imaging means 33 is aligned with the surface Wa of the wafer W. The time lag with the match time can be offset. Therefore, it is not necessary to step up and down the image pickup means 33 with fine resolution, it is not necessary to grasp the thickness of the wafer W, and the surface Wa of the wafer W can be focused efficiently.

  As described above, when the height position of the image pickup means 33 when the surface Wa is in focus is obtained by any one of the methods 1 and 2 for obtaining the focus position, the elevating means 34 moves the image pickup means 33 to the intermediate position Z3. Move. In this state, the surface Wa is imaged, and the image processing unit 84 shown in FIG. 1 displays an image such as pattern matching while moving the two imaging means 33 together with the cutting means 3a and 3b in the X-axis direction and the Y-axis direction. When the processing is performed, the division planned line L shown in FIG. 1 is detected. Then, by detecting the scheduled division line L, the position of the cutting blade 30 in the Y-axis direction is aligned with the detected planned division line L. By performing such alignment with respect to the cutting blades 30 of the cutting means 3a and 3b, the two cutting blades 30 are aligned with different division planned lines L, respectively. For example, the cutting blade 30 of the cutting means 3a is aligned with the division schedule line L closest to the + Y side, and the cutting blade 30 of the cutting means 3b is aligned with the division division line L closest to the −Y side.

  Next, in a state where the two cutting blades 30 constituting the cutting means 3a and 3b are aligned with different division lines L, the two cutting blades 30 are rotated and the two infeed means 5 are moved to the cutting means 3a. 3b is moved in the −Z direction to place the two cutting blades 30 at a predetermined height position, and the cutting feed means 2 shown in FIG. 1 cuts and feeds the holding means 7 in the −X direction. Then, cutting is performed along the two scheduled division lines L.

  Next, the index feeding means 4 indexes feeds the cutting means 3a and 3b in the direction in which the two cutting blades 30 approach each other by an interval between the adjacent division planned lines L, and the two divided division lines L that have already been cut. Each adjacent division planned line L is cut. After such cutting is performed for all the division planned lines L in the same direction, the holding means 7 is rotated 90 degrees and then the same cutting is performed, whereby the wafer W is cut vertically and horizontally for each device D. Divided into chips.

  After the division of one wafer W is completed, the divided wafer W is detached from the holding means 7 and the wafer to be divided next is held in the holding means 7. Since the wafer to be newly divided may have a thickness different from that of the already divided wafer, the first position and the second position are obtained by the same method as described above, and an intermediate value between these values is obtained. Is the position in the Z-axis direction of the imaging means 33 when the surface of the wafer is in focus. Then, a line to be divided is detected at that position, and cutting is performed in the same manner as described above.

  As described above, each time the wafers to be divided are replaced, the position of the imaging means 33 when each wafer is focused on the surface of the wafer is obtained, so that even when the thickness of each wafer is different. The imaging means 33 can be accurately focused on the surface of the wafer.

  In the above “Focus Position Determination Method 1”, after storing the image captured by the image capturing unit 33 and the position of the image capturing unit 33 in the Z-axis direction, it is determined whether or not the stored image is in focus. However, after storing the image captured by the imaging unit 33, it is determined whether or not the image is in focus, and then the position of the imaging unit 33 in the Z-axis direction is stored. Good.

  In the present embodiment, the encoder recognizes the height position of the imaging means 33. For example, a scale is disposed in parallel to the ball screw 340 shown in FIG. A reading unit may be provided, and the first position and the second position may be recognized by recognizing the height position of the imaging unit 33 based on the scale scale reading value.

  In the present embodiment, the cutting apparatus is described as an example of the processing apparatus. However, the present invention includes other processing apparatuses having a function of imaging the surface of the wafer. For example, the processing apparatus may be a laser processing apparatus that irradiates a laser beam along a planned division line of the wafer W. The processing in the laser processing apparatus may be processing for forming a groove on the upper surface of the wafer or processing for forming a modified layer inside the wafer.

W: Wafer Wa: Front surface L: Divided line D: Device Wb: Back surface T: Dicing tape F: Frame 1: Cutting device 2: Cutting feed means 20: Ball screw 21: Guide rail 22: Motor 23: Rotating means 24: Movement Bases 3a, 3b: Cutting means 30: Cutting blade 31: Housing 32: Cutting water nozzle 33: Imaging means 33a, 33b, 33c: Focus 34: Lifting means 340: Ball screw 341: Motor 342: Encoder 343: Support section 4: Index feeding means 40: Ball screw 40 41: Guide rail 42: Motor 43: Moving base 5: Cutting feed means 50: Ball screw 51: Guide rail 52: Motor 53: Lifting base 6: Clamping part 7: Holding means 70: Suction Unit 700: holding surface 71: frame 8: control means 81: first storage unit 82: first 2 storage unit 83: calculation unit 84: image processing unit Z1, Z4: first position Z2, Z5: second position Z3: intermediate position

Claims (1)

A holding means for holding the surface of the plate-like workpiece on which the device is divided and divided by lines to be divided, and an imaging means for imaging the surface of the plate-like workpiece held by the holding means from above; Elevating means for lowering and raising the imaging means with respect to the holding means, processing means for processing a plate-like workpiece held by the holding means along a scheduled division line, and controlling at least the imaging means and the raising / lowering means A processing device comprising:
The control means includes
When the lifting and lowering means lowers the imaging means at a constant speed, the focus of the imaging means for imaging the plate-like workpiece is lowered from above the surface of the plate-like workpiece and matches the surface of the plate-like workpiece. A first storage unit that stores the position of the imaging unit as a first position when it is located below or less than the upper part of the time,
When the elevating means raises the imaging means at the constant speed, the focus of the imaging means for imaging the plate-like workpiece rises from below the surface of the plate-like workpiece and matches the surface of the plate-like workpiece. A second storage unit that stores the position of the imaging unit as a second position when it is located above or below the lower than
A calculation unit that calculates an intermediate position between the first position stored in the first storage unit and the second position stored in the second storage unit;
A processing apparatus that sets the intermediate position calculated by the calculation unit to a position where the focal point of the imaging unit is aligned with the surface of the plate-like workpiece.

Images