Processing apparatus and processing method for workpieces

Abstract

The present invention provides a processing apparatus that can identify the location of processing marks formed on a workpiece while suppressing an increase in the size of the holding table. [Solution] A processing apparatus for processing a workpiece having a first surface and a second surface, with a sheet fixed to the first surface side, comprising: a holding table for holding the first surface side of the workpiece; a processing unit for processing the workpiece and sheet held by the holding table along a street, thereby forming a first processing mark on the workpiece extending from the second surface to the first surface, and forming a second processing mark on the sheet located on the extension of the first processing mark; a first imaging unit for imaging the first processing mark; and a second imaging unit for imaging the second processing mark.

Description

Technical Field

[0001] The present invention relates to a processing apparatus for processing a workpiece and a method for processing a workpiece.

Background Art

[0002] Device chips including devices are manufactured by dividing a wafer on which a plurality of devices are formed into individual pieces. Further, a package substrate is formed by covering and sealing a plurality of device chips mounted on a predetermined substrate with a resin layer (mold resin). By dividing this package substrate into individual pieces, a package device including a plurality of packaged device chips is manufactured. The device chips and the package devices are incorporated into various electronic devices such as mobile phones and personal computers.

[0003] A cutting device is used to divide workpieces such as wafers and package substrates. The cutting device includes a holding table having a holding surface for holding the workpiece and a processing unit (cutting unit) for performing cutting processing on the workpiece. The cutting unit includes a spindle, and an annular cutting blade for cutting the workpiece is mounted on the tip of the spindle. The workpiece is held by the holding table, and the cutting blade is rotated and cut into the workpiece, whereby the workpiece is cut and divided.

[0004] After processing the workpiece, a process of observing the workpiece to inspect the processing quality may be performed. For example, a process called a kerf check is executed in which the processed workpiece is imaged to inspect the processing marks formed on the workpiece (see Patent Document 1). By performing such an inspection, for example, it is possible to detect a deviation between the planned processing position and the actually processed position, and perform processing such as correcting the processing position of the workpiece according to the deviation amount.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2016-197702 [Overview of the project] [Problems that the invention aims to solve]

[0006] To inspect machining marks formed on a workpiece, it is necessary to image the machining marks with an imaging unit (camera). However, when a workpiece is machined, it is positioned so that one side (the side to be held) faces the holding surface of the holding table, and the side of the workpiece that is to be held is covered by the holding table. Therefore, it becomes difficult to observe the machining marks formed on the side of the workpiece that is to be held.

[0007] Therefore, when it is necessary to observe the side of the workpiece that is being held, the holding table is configured to enable imaging of the side of the workpiece that is being held. For example, a holding table is used that holds the workpiece with a transparent holding member and an annular frame that supports the outer circumference of the holding member. This makes it possible to image the side of the workpiece that is being held through the transparent holding member, and to obtain an image of the machining marks formed on the side of the workpiece that is being held.

[0008] However, when a relatively large workpiece is held by the above-mentioned holding table, the central part of the workpiece is held by the transparent holding member, but the outer periphery of the workpiece protrudes outside the holding member and is covered by the frame. In this case, it becomes difficult to image the held surface on the outer periphery of the workpiece, and observation of some of the machining marks formed on the held surface side of the workpiece is hindered.

[0009] To resolve the above-mentioned issues, one possible method is to enlarge the imaging range through the transparent holding member by setting its size to be larger than the size of the workpiece. However, enlarging the holding member necessitates enlarging the frame supporting it, resulting in a larger holding table. As a result, miniaturization of the processing equipment is hindered. Furthermore, if the layout of each component of the processing equipment is precisely set, a larger holding table may make it difficult to even mount the holding table on the processing equipment.

[0010] This invention has been made in view of the above problems, and aims to provide a processing apparatus and a method for processing a workpiece that can identify the location of processing marks formed on the workpiece while suppressing an increase in the size of the holding table. [Means for solving the problem]

[0011] According to one aspect of the present invention, a processing apparatus for processing a workpiece having a first surface and a second surface, with a sheet fixed to the first surface side, comprising: a holding table for holding the first surface side of the workpiece; a processing unit for processing the workpiece and the sheet held by the holding table along a street, thereby forming a first processing mark on the workpiece extending from the second surface to the first surface, and forming a second processing mark on the sheet located on the extension of the first processing mark; a first imaging unit for imaging the first processing mark; and a second imaging unit for imaging the second processing mark. A processing apparatus is provided comprising a unit and a holding table, wherein the holding table holds the workpiece and the sheet by a holding member that is transparent to light received by the first imaging unit and a frame that supports the outer periphery of the holding member, the first imaging unit images the first processing mark formed in a region of the workpiece that does not overlap with the frame from the first surface side of the workpiece via the holding member, and the second imaging unit images the second processing mark located on the extension of the first processing mark formed in a region of the workpiece that overlaps with the frame.

[0012] Preferably, the processing apparatus further includes a controller that corrects the processing position of the workpiece by the processing unit based on the position of the first processing mark captured by the first imaging unit and the position of the second processing mark captured by the second imaging unit.

[0013] Furthermore, according to another aspect of the present invention, a method for processing a workpiece having a first surface and a second surface, with a sheet fixed to the first surface side, comprising: a holding step of holding the first surface side of the workpiece with a holding table comprising a holding member that is transparent to light received by a first imaging unit and a frame that supports the outer periphery of the holding member; and processing the workpiece and the sheet held by the holding table along a street, thereby creating a first processing mark from the second surface to the first surface. A method for processing a workpiece is provided, comprising: a processing step of forming a second processing mark on a sheet which is formed on the workpiece and located on the extension of the first processing mark; a first imaging step of imaging the first processing mark formed in a region of the workpiece that does not overlap with the frame body of the workpiece using a first imaging unit from the first surface side of the workpiece via the holding member; and a second imaging step of imaging the second processing mark formed in a region of the workpiece that overlaps with the frame body of the workpiece and located on the extension of the first processing mark of the workpiece using a second imaging unit.

[0014] Preferably, the method for processing the workpiece further includes a correction step after the first imaging step and the second imaging step, in which the processing position of the workpiece is corrected based on the position of the first processing mark captured by the first imaging unit and the position of the second processing mark captured by the second imaging unit. [Effects of the Invention]

[0015] In the processing apparatus and the method for processing a workpiece according to one aspect of the present invention, a first processing mark formed in a region that does not overlap with the frame of the workpiece 11 is imaged by the first imaging unit from the first surface side of the workpiece through the holding member, and a second processing mark located on the extension line of the first processing mark formed in a region that overlaps with the frame of the workpiece is imaged by the second imaging unit. As a result, without changing the configuration of the holding table, the position of the processing mark formed on the first surface side of the workpiece can be specified over the entire area of the workpiece.

Brief Description of the Drawings

[0016] [Figure 1] It is a perspective view showing a cutting device. [Figure 2] It is a perspective view showing a workpiece. [Figure 3] It is a perspective view showing a holding unit and an imaging unit. [Figure 4] It is a cross-sectional view showing a holding table. [Figure 5] It is a perspective view showing an imaging unit and a Z-axis moving mechanism. [Figure 6] It is a flowchart showing a method for processing a workpiece. [Figure 7] It is a cross-sectional view showing a cutting device in a holding step. [Figure 8] It is a cross-sectional view showing a cutting device in a processing step. [Figure 9] It is a plan view showing a workpiece and a sheet after a processing step. [Figure 10] It is a cross-sectional view showing a cutting device in an imaging step. [Figure 11] FIG. 11(A) is an image diagram showing an image acquired by the first imaging unit, and FIG. 11(B) is an image diagram showing an image acquired by the second imaging unit. [Figure 12] FIG. 12(A) is a block diagram showing a controller, and FIG. 12(B) is a schematic diagram showing a method for correcting a processing position.

Embodiments for Carrying Out the Invention

[0017] Hereinafter, an embodiment according to an aspect of the present invention will be described with reference to the accompanying drawings. First, a configuration example of a processing apparatus according to this embodiment will be described. FIG. 1 is a perspective view showing a cutting apparatus 2 for cutting a workpiece 11. In FIG. 1, the X-axis direction (processing feed direction, first horizontal direction, front-rear direction), the Y-axis direction (indexing feed direction, second horizontal direction, left-right direction), and the Z-axis direction (vertical direction, height direction, vertical direction) are perpendicular to each other.

[0018] The cutting apparatus 2 includes a rectangular parallelepiped base 4 that supports or houses each component constituting the cutting apparatus 2. A rectangular opening 4a is provided at a corner on the front end side of the base 4. Inside the opening 4a, a cassette support base 6 that moves up and down by an elevating mechanism (not shown) is provided. On the upper surface of the cassette support base 6, a cassette 8 capable of accommodating a plurality of workpieces to be processed by the cutting apparatus 2 is arranged. In FIG. 1, only the outline of the cassette 8 is shown by a two-dot chain line.

[0019] FIG. 2 is a perspective view showing the workpiece 11. For example, the workpiece 11 is a disk-shaped wafer made of a semiconductor material such as single crystal silicon, and includes a first surface (front surface) 11a and a second surface (back surface) 11b that are substantially parallel to each other.

[0020] The first surface 11a of the workpiece 11 is divided into multiple rectangular regions by multiple streets (division lines) 13 arranged in a grid pattern so as to intersect each other. Furthermore, devices 15 such as ICs (Integrated Circuits), LSIs (Large Scale Integrations), LEDs (Light Emitting Diodes), and MEMS (Micro Electro Mechanical Systems) are formed in each of the regions divided by the streets 13. In other words, the first surface 11a of the workpiece 11 corresponds to the device surface on which multiple devices 15 are formed. By dividing the workpiece 11 along the streets 13 and separating it into individual pieces, multiple device chips, each containing a device 15, are manufactured.

[0021] However, there are no restrictions on the material, shape, structure, size, etc., of the workpiece 11. For example, the workpiece 11 may be a substrate made of semiconductors other than silicon (GaAs, InP, GaN, SiC, etc.), glass, ceramics, resin, metal, etc. Furthermore, there are no restrictions on the type, quantity, shape, structure, size, arrangement, etc., of the devices 15, and the workpiece 11 does not even need to have devices 15 formed on it.

[0022] When cutting the workpiece 11 with the cutting device 2 (see Figure 1), the workpiece 11 is supported by an annular frame 17 for the convenience of handling (transportation, holding, etc.) the workpiece 11. The frame 17 is made of a metal such as SUS (stainless steel), and a circular opening 17a is provided in the center of the frame 17, penetrating the frame 17 in the thickness direction. The diameter of the opening 17a is larger than the diameter of the workpiece 11.

[0023] A circular sheet 19 is fixed to the workpiece 11 and the frame 17. For example, the sheet 19 is a circular tape (dicing tape) that includes a film-like base material and an adhesive layer (glue layer) provided on the base material. The base material is made of a resin such as polyolefin, polyvinyl chloride, or polyethylene terephthalate, and the adhesive layer is made of an epoxy, acrylic, or rubber-based adhesive. However, a heat-sealable sheet that does not have an adhesive layer (glue layer) and can be heat-pressed to the workpiece 11 and the frame 17 can also be used as the sheet 19.

[0024] With the workpiece 11 positioned inside the opening 17a of the frame 17, the central part of the sheet 19 is fixed to the first surface 11a side of the workpiece 11, and the outer periphery of the sheet 19 is fixed to the frame 17. As a result, the workpiece 11 is supported by the frame 17 via the sheet 19, and the first surface 11a side (device side) of the workpiece 11 is covered and protected by the sheet 19. The workpiece 11 is then housed in the cassette 8 (see Figure 1) while supported by the frame 17.

[0025] As shown in Figure 1, a rectangular opening 4b is provided on the side of the opening 4a of the base 4, with its longitudinal direction aligned with the X-axis. Inside the opening 4b, a holding unit 10 is provided to hold the workpiece to be processed by the cutting device 2.

[0026] The holding unit 10 includes a holding table (chuck table) 12 for holding the workpiece 11 and the sheet 19 (see Figure 2). The upper surface of the holding table 12 is a flat surface that is generally parallel to the horizontal plane (XY plane) and forms a circular holding surface 12a for holding the workpiece 11. In addition, multiple clamps (not shown) are provided around the holding table 12 for gripping and fixing the frame 17 (see Figure 2) that supports the workpiece 11. Furthermore, an imaging unit 14 (see Figure 3) for imaging the workpiece 11 held by the holding unit 10 is provided inside the opening 4b. Details of the holding unit 10 and the imaging unit 14 will be described later.

[0027] The front and rear of the holding table 12 are provided with bellows-shaped dustproof and splashproof covers 16 that extend and retract along the X-axis. The dustproof and splashproof covers 16 are fitted to cover the opening 4b and protect the components of the cutting device 2 located inside the opening 4b.

[0028] Near the openings 4a and 4b, a transport unit (not shown) is provided for transporting the workpiece 11 between the cassette 8 and the holding table 12. The workpiece 11 is pulled out from the cassette 8 by the transport unit and transported to the holding table 12, where it is held.

[0029] A gate-shaped support structure 18 is provided on the upper surface of the base 4. The support structure 18 is installed so as to straddle the opening 4b, and the front of the support structure 18 is positioned along the YZ plane. A pair of movable units 20A and 20B are provided on the front sides of both ends of the support structure 18. For example, the movable units 20A and 20B are ball screw type movable mechanisms and are mounted on a pair of Y-axis guide rails 22 that are positioned along the Y-axis direction on the front side of the support structure 18.

[0030] The moving unit 20A includes a flat Y-axis moving plate 24A. The Y-axis moving plate 24A is slidably mounted on a pair of Y-axis guide rails 22. A nut portion (not shown) is provided on the back side (rear side) of the Y-axis moving plate 24A. A Y-axis ball screw 26A, which is positioned along the Y-axis direction between the pair of Y-axis guide rails 22, is screwed into this nut portion. A Y-axis pulse motor 28 is connected to the end of the Y-axis ball screw 26A. When the Y-axis pulse motor 28 rotates the Y-axis ball screw 26A, the Y-axis moving plate 24A moves along the Y-axis direction along the Y-axis guide rails 22.

[0031] A pair of Z-axis guide rails 30A are fixed to the front surface of the Y-axis moving plate 24A along the Z-axis direction. A flat Z-axis moving plate 32A is slidably mounted on the pair of Z-axis guide rails 30A. A nut portion (not shown) is provided on the back surface of the Z-axis moving plate 32A. A Z-axis ball screw 34A, which is positioned between the pair of Z-axis guide rails 30A along the Z-axis direction, is screwed into this nut portion. A Z-axis pulse motor 36A is connected to the end of the Z-axis ball screw 34A. When the Z-axis ball screw 34A is rotated by the Z-axis pulse motor 36A, the Z-axis moving plate 32A moves along the Z-axis guide rails 30A in the Z-axis direction.

[0032] Similarly, the mobile unit 20B includes a flat Y-axis mobile plate 24B. The Y-axis mobile plate 24B is slidably mounted on a pair of Y-axis guide rails 22. A nut portion (not shown) is provided on the back side (rear side) of the Y-axis mobile plate 24B. A Y-axis ball screw 26B, which is positioned along the Y-axis direction between the pair of Y-axis guide rails 22, is screwed into this nut portion. A Y-axis pulse motor (not shown) is connected to the end of the Y-axis ball screw 26B. When the Y-axis ball screw 26B is rotated by the Y-axis pulse motor, the Y-axis mobile plate 24B moves along the Y-axis guide rails 22 in the Y-axis direction.

[0033] A pair of Z-axis guide rails 30B are fixed to the front surface of the Y-axis moving plate 24B along the Z-axis direction. A flat Z-axis moving plate 32B is slidably mounted on the pair of Z-axis guide rails 30B. A nut portion (not shown) is provided on the back surface of the Z-axis moving plate 32B. A Z-axis ball screw 34B, which is positioned between the pair of Z-axis guide rails 30B along the Z-axis direction, is screwed into this nut portion. A Z-axis pulse motor 36B is connected to the end of the Z-axis ball screw 34B. When the Z-axis ball screw 34B is rotated by the Z-axis pulse motor 36B, the Z-axis moving plate 32B moves along the Z-axis guide rails 30B in the Z-axis direction.

[0034] Machining units (cutting units) 38A and 38B are fixed to the lower ends of the Z-axis moving plates 32A and 32B, respectively, for cutting the workpiece 11. Each machining unit 38A and 38B is equipped with a cylindrical spindle 40 (see Figure 8) arranged along the Y-axis, and an annular cutting blade 42 is attached to the tip of the spindle 40. By rotating the cutting blade 42 attached to the machining units 38A and 38B and cutting into the workpiece 11 held by the holding table 12, the workpiece 11 is cut.

[0035] As the cutting blade 42, for example, a hub-type cutting blade (hub blade) can be used. The hub blade comprises an annular hub base made of a metal such as an aluminum alloy, and an annular cutting edge formed along the outer edge of the hub base. The cutting edge of the hub blade is made of an electroformed grinding wheel containing abrasive grains made of diamond, cubic boron nitride (cBN), etc., and a binder such as a nickel plating layer that fixes the abrasive grains. However, a washer-type cutting blade (washer blade) can also be used as the cutting blade 42. The washer blade consists only of an annular cutting edge containing abrasive grains and a binder made of metal, ceramics, resin, etc. that fixes the abrasive grains.

[0036] Imaging units 44 are provided adjacent to the processing units 38A and 38B. The imaging units 44 are cameras (visible light cameras, infrared cameras, etc.) capable of imaging the workpiece 11 and sheet 19 held by the holding table 12, and are equipped with image sensors such as CCD (Charged-Coupled Devices) sensors and CMOS (Complementary Metal-Oxide-Semiconductor) sensors. The images acquired by the imaging units 44 are used for alignment of the workpiece 11 and the cutting blade 42, inspection of processing marks, etc.

[0037] A circular opening 4c is provided to the side of the opening 4b. Inside the opening 4c is a cleaning unit 46 for cleaning the workpiece 11. The cleaning unit 46 includes a spinner table 48 that holds and rotates the workpiece 11, and a nozzle 50 that supplies cleaning liquid (cleaning solution) to the workpiece 11 held by the spinner table 48.

[0038] The upper surface of the spinner table 48 is a flat surface that is generally parallel to the horizontal plane (XY plane) and constitutes a circular holding surface 48a for holding the workpiece 11. The holding surface 48a is connected to a suction source (not shown), such as an ejector, via a flow path (not shown), a valve (not shown), etc., provided inside the spinner table 48. The spinner table 48 is also connected to a rotational drive source (not shown), such as a motor, which rotates the spinner table 48 around a rotation axis that is generally parallel to the Z-axis direction.

[0039] The nozzle 50 supplies cleaning fluid toward the holding surface 48a of the spinner table 48. As the cleaning fluid, a liquid such as pure water or a mixed fluid containing a liquid (such as pure water) and a gas (such as air) can be used.

[0040] The workpiece 11 processed by the processing units 38A and 38B is transported to the spinner table 48 by a transport unit (not shown) and placed on the holding surface 48a of the spinner table 48 via a sheet 19. In this state, when the suction force (negative pressure) of the suction source is applied to the holding surface 48a, the workpiece 11 is held by the spinner table 48 via the sheet 19. Then, by supplying cleaning fluid from the nozzle 50 toward the workpiece 11 while rotating the spinner table 48, the workpiece 11 is cleaned.

[0041] Furthermore, the cutting device 2 is equipped with a display unit (display section, display device) 52 that displays various information related to the cutting device 2. The display unit 52 can be made up of various types of displays. For example, a touch panel display can be used as the display unit 52. In this case, the display unit 52 also functions as an input unit (input section, input device) for inputting various information into the cutting device 2, and the operator can input information such as machining conditions into the cutting device 2 by touching the display unit 52. In other words, the display unit 52 functions as a user interface. However, the input unit may be an electronic device such as a keyboard, mouse, or transceiver that is provided independently of the display unit 52.

[0042] Furthermore, the cutting device 2 includes a controller (control unit, control unit, control device) 54 that controls the cutting device 2. The controller 54 is connected to each component that makes up the cutting device 2 (cassette support base 6, holding unit 10, imaging unit 14, moving units 20A, 20B, processing units 38A, 38B, imaging unit 44, cleaning unit 46, display unit 52, etc.). The controller 54 then outputs control signals to each component of the cutting device 2 to control the operation of the component.

[0043] For example, the controller 54 is composed of a computer and includes a processing unit that performs calculations and other processing necessary for the operation of the cutting device 2, and a storage unit that stores various information (data, programs, etc.) used for the operation of the cutting device 2. The processing unit includes a processor such as a CPU (Central Processing Unit). The storage unit includes memory such as ROM (Read Only Memory) and RAM (Random Access Memory).

[0044] Next, the details of the holding unit 10 and imaging unit 14 provided in the cutting device 2 will be described. Figure 3 is a perspective view showing the holding unit 10 and imaging unit 14. As mentioned above, the holding unit 10 and imaging unit 14 are installed inside the opening 4b (see Figure 1) of the base 4.

[0045] The holding unit 10 includes a holding table 12 for holding the workpiece 11 and the sheet 19 (see Figure 2). The holding table 12 includes a plate-shaped holding member 60 and an annular frame 62 that supports the outer periphery of the holding member 60.

[0046] Figure 4 is a cross-sectional view showing the holding table 12. For example, the holding member 60 is formed in a disc shape and has a first surface (upper surface) 60a and a second surface (lower surface) 60b that are generally parallel to each other. The holding member 60 is also made of a material that is transparent to light received by the imaging unit 14, which will be described later. For example, if the imaging unit 14 is equipped with a visible light camera, the holding member 60 is made of a transparent material (such as soda glass, borosilicate glass, or quartz glass) that allows at least a portion of the visible light to pass through. The transmittance of light received by the imaging unit 14 to the holding member 60 is, for example, 70% or more, preferably 80% or more, and more preferably 90% or more.

[0047] The frame 62 is an annular member made of metal such as stainless steel or resin, and has a first surface (upper surface) 62a and a second surface (lower surface) 62b that are generally parallel to each other. A cylindrical housing portion (recess) 62c is provided on the first surface 62a side of the central part of the frame 62. The diameter of the housing portion 62c is generally equal to the diameter of the retaining member 60, and the retaining member 60 is fitted into the housing portion 62c. In addition, a cylindrical opening 62d is provided on the second surface 62b side of the frame 62, extending from the bottom of the housing portion 62c to the second surface 62b. The diameter of the opening 62d is smaller than the diameter of the housing portion 62c, and the retaining member 60 is supported from below by the stepped portion inside the frame 62 formed by the housing portion 62c and the opening 62d.

[0048] The depth of the housing section 62c and the thickness of the retaining member 60 are approximately equal. Therefore, the first surface 60a of the retaining member 60 and the first surface 62a of the frame 62 are arranged on the same plane, which is approximately parallel to the XY plane. The first surface 60a of the retaining member 60 and the first surface 62a of the frame 62 then constitute the retaining surface 12a of the retaining table 12.

[0049] The workpiece 11 is placed on the holding surface 12a via the sheet 19. In addition, suction grooves (not shown) are formed along the holding surface 12a on the first surface 60a side of the holding member 60 and / or the first surface 62a side of the frame 62. The suction grooves are connected to a suction source (not shown), such as an ejector, via suction passages (not shown) formed inside the holding member 60 and / or the frame 62. By applying the suction force (negative pressure) of the suction source to the holding surface 12a via the suction grooves and suction passages, the workpiece 11 is held by suction from the sheet 19 by the holding table 12.

[0050] As shown in Figure 3, the holding table 12 is supported by a movable table 64. The movable table 64 comprises a rectangular bottom plate 64a, rectangular side plates 64b projecting upward from the side ends of the bottom plate 64a, and a top plate 64c projecting laterally from the upper ends of the side plates 64b. The bottom plate 64a and the top plate 64c are arranged along the XY plane so as to face each other. The side plates 64b are arranged along the XZ plane, approximately perpendicular to the bottom plate 64a and the top plate 64c. An imaging space 64d for imaging the workpiece 11 is secured in the area enclosed by the bottom plate 64a, the side plates 64b, and the top plate 64c. The imaging space 64d corresponds to a rectangular parallelepiped space located between the bottom plate 64a and the top plate 64c, and to the side of the side plates 64b.

[0051] The frame 62 of the holding table 12 is supported by the top plate 64c of the moving table 64, allowing it to rotate around a rotation axis that is approximately parallel to the Z-axis direction. The top plate 64c has a circular opening (not shown) that penetrates through the top plate 64c in the thickness direction. The diameter of the opening in the top plate 64c is set to be less than the diameter of the frame 62, and greater than or equal to the diameter of the opening 62d (see Figure 4) of the frame 62. The holding table 12 is positioned so that the opening 62d of the frame 62 and the opening of the top plate 64c overlap. Therefore, the top plate 64c supports only the outer periphery of the holding table 12, and the lower end of the central part of the holding table 12 is exposed toward the imaging space 64d.

[0052] A moving unit 66 is connected to the moving table 64. The moving unit 66 is, for example, a ball screw type moving mechanism, which moves the holding table 12 and the moving table 64 along the X-axis.

[0053] Specifically, the moving unit 66 includes a pair of X-axis guide rails 68 arranged along the X-axis direction. The bottom plate 64a of the moving table 64 is slidably mounted on the pair of X-axis guide rails 68. A nut portion (not shown) is provided on the underside of the bottom plate 64a, and an X-axis ball screw 70, which is arranged along the X-axis direction between the pair of X-axis guide rails 68, is screwed into this nut portion. An X-axis pulse motor 72 is also connected to the end of the X-axis ball screw 70. When the X-axis ball screw 70 is rotated by the X-axis pulse motor 72, the holding table 12 and the moving table 64 move along the X-axis guide rails 68 in the X-axis direction.

[0054] An annular pulley 74 is fixed to the frame 62 of the holding table 12, which is supported by the movable table 64, so as to surround the frame 62. A rotational drive source 76 for rotating the holding table 12 is also provided on the side of the holding table 12. For example, the rotational drive source 76 is made up of a motor or the like and is mounted on the side plate 64b of the movable table 64. A pulley 78 is fixed to the rotation shaft (output shaft) of the rotational drive source 76. A connecting member 80, such as an endless belt, is wrapped around the pulleys 74 and 78.

[0055] When the rotary drive source 76 is activated, the pulley 78 fixed to the rotation shaft of the rotary drive source 76 rotates. The rotational power of pulley 78 is then transmitted to pulley 74 via the connecting member 80, causing the holding table 12, on which pulley 74 is mounted, to rotate around a rotation shaft that is approximately parallel to the Z-axis direction. In other words, the pulleys 74, 78 and the connecting member 80 constitute a power transmission mechanism that transmits the rotational power of the rotary drive source 76 to the holding table 12. By controlling the rotation angle of the rotation shaft of the rotary drive source 76, the rotation angle of the holding table 12 can be adjusted arbitrarily.

[0056] However, the mechanism for rotating the holding table 12 is not limited to the above. For example, a direct drive motor (DDM) can be used as the motor for rotating the holding table 12. In this case, the motor's rotation shaft is directly connected to the holding table 12. This creates a direct drive type rotation mechanism that can directly transmit the motor's power to the holding table 12 without going through intermediate mechanisms (pulleys 74, 78, connecting members 80, reduction gears, etc.).

[0057] In front of the holding unit 10 is an imaging unit 14 that images the workpiece 11 held by the holding table 12. The imaging unit 14 is connected to a moving unit 90 that moves the imaging unit 14. The moving unit 90 includes a Y-axis moving mechanism 92 and a Z-axis moving mechanism 102, and moves the imaging unit 14 along the Y-axis and Z-axis directions.

[0058] The Y-axis movement mechanism 92 includes a flat Y-axis movement plate 94. The Y-axis movement plate 94 is slidably mounted on a pair of Y-axis guide rails 96 arranged along the Y-axis direction. A nut portion (not shown) is provided on the lower surface of the Y-axis movement plate 94, and a Y-axis ball screw 98, which is arranged along the Y-axis direction between the pair of Y-axis guide rails 96, is screwed into this nut portion. A Y-axis pulse motor 100 is also connected to the end of the Y-axis ball screw 98. When the Y-axis pulse motor 100 rotates the Y-axis ball screw 98, the Y-axis movement plate 94 moves along the Y-axis guide rails 96 in the Y-axis direction.

[0059] Figure 5 is a perspective view showing the imaging unit 14 and the Z-axis movement mechanism 102. The Z-axis movement mechanism 102 includes a columnar support structure 104 fixed to the upper surface of the Y-axis movement plate 94 (see Figure 3). The surface of the support structure 104 is positioned approximately parallel to the YZ plane. A pair of Z-axis guide rails 106 are fixed to the surface side of the support structure 104 along the Z-axis direction.

[0060] A flat Z-axis moving plate 108 is slidably mounted on a pair of Z-axis guide rails 106. A nut (not shown) is provided on the back side of the Z-axis moving plate 108, and a Z-axis ball screw 110, which is positioned along the Z-axis direction between the pair of Z-axis guide rails 106, is screwed into this nut. A Z-axis pulse motor 112 is connected to the end of the Z-axis ball screw 110. When the Z-axis pulse motor 112 rotates the Z-axis ball screw 110, the Z-axis moving plate 108 moves along the Z-axis guide rails 106 in the Z-axis direction.

[0061] A support arm 114 is fixed to the surface of the Z-axis moving plate 108, protruding in the X-axis direction from the surface of the Z-axis moving plate 108. The imaging unit 14 is mounted on the tip of the support arm 114. By moving the Y-axis moving plate 94 (see Figure 3) with the Y-axis moving mechanism 92 (see Figure 3), the imaging unit 14 is moved along the Y-axis direction. Similarly, by moving the Z-axis moving plate 108 with the Z-axis moving mechanism 102, the imaging unit 14 is moved along the Z-axis direction. This allows the position of the imaging unit 14 in the Y-axis and Z-axis directions to be set arbitrarily.

[0062] For example, the imaging unit 14 includes cameras 120A and 120B with different magnifications. Camera 120A is a low-magnification camera, and camera 120B is a high-magnification camera with a higher magnification than camera 120A. Cameras 120A and 120B are cameras (visible light camera, infrared camera, etc.) capable of imaging the workpiece 11, and are equipped with image sensors such as CCD sensors and CMOS sensors. Cameras 120A and 120B are mounted on the support arm 114 in a state that allows imaging upwards. However, the imaging unit 14 may have only one of cameras 120A or 120B, or it may have three or more cameras with different magnifications.

[0063] Illuminators 122A and 122B are provided to the sides of cameras 120A and 120B, respectively, to illuminate the workpiece 11, which is the subject of the imaging. When imaging the workpiece 11 with cameras 120A and 120B, illuminating the workpiece 11 with light from illuminations 122A and 122B allows for the acquisition of a clear image of the workpiece 11.

[0064] As shown in Figure 3, when the imaging unit 14 images the workpiece 11, the position of the imaging unit 14 is adjusted by the moving unit 90 so that the imaging space 64d secured inside the moving table 64 and the imaging unit 14 are aligned in the Y-axis and Z-axis directions. Then, the moving unit 66 moves the holding table 12 and the moving table 64 toward the imaging unit 14. As a result, the imaging unit 14 is inserted into the imaging space 64d, and the workpiece 11 held by the holding table 12 can be imaged from below by the imaging unit 14.

[0065] Next, a specific example of a workpiece processing method using the cutting device 2 described above will be explained. Figure 6 is a flowchart of the workpiece processing method. In this embodiment, after cutting the workpiece 11, the processing marks formed on the workpiece 11 are captured by the imaging unit 14, and the processing marks formed on the sheet 19 are captured by the imaging unit 44.

[0066] When processing and imaging the workpiece 11 with the cutting device 2, the workpiece 11 is first held by the holding table 12 (holding step S1). Figure 7 is a cross-sectional view showing the cutting device 2 in the holding step S1.

[0067] In this embodiment, the first surface 11a (device surface) of the workpiece 11 is held by the holding table 12. Specifically, the workpiece 11 is placed on the holding table 12 such that the first surface 11a (sheet 19 side) faces the holding surface 12a and the second surface 11b is exposed upwards. The frame 17 (see Figure 2) supporting the workpiece 11 is fixed by a plurality of clamps (not shown) provided around the holding table 12. In this state, when the suction force (negative pressure) of the suction source is applied to the holding surface 12a, the workpiece 11 is held by the holding table 12 via the sheet 19.

[0068] The diameter of the workpiece 11 is smaller than the diameter of the holding surface 12a (the diameter of the frame 62) and larger than the diameter of the opening 62d of the frame 62. Therefore, the workpiece 11 has a first region 21A that overlaps with the holding member 60 but does not overlap with the frame 62 (overlapping with the opening 62d), and a second region 21B that overlaps with the frame 62 (but does not overlap with the opening 62d).

[0069] The first region 21A is a disc-shaped region including the center of the workpiece 11, and corresponds to the imaging region where the first surface 11a is imaged by the imaging unit 14 (see Figure 4, etc.) in the imaging step S3 described later. The second region 21B is an annular region including the outer edge of the workpiece 11 and surrounding the first region 21A, and corresponds to the non-imaging region where the first surface 11a is not imaged by the imaging unit 14 (see Figure 4, etc.) in the imaging step S3 described later. The second region 21B may include a region that overlaps with the holding member 60.

[0070] The first region 21A and the second region 21B each include a plurality of devices 15 (see Figure 2) formed on the first surface 11a side of the workpiece 11. In the region of the holding table 12 that overlaps with the first region 21A of the workpiece 11, the second surface 60b side of the holding member 60 is exposed inside the opening 62d.

[0071] Furthermore, the sheet 19 is not fixed to the workpiece 11 and has a holding area 19a that is held by the holding surface 12a. That is, the holding area 19a corresponds to the area of ​​the sheet 19 from the outer edge of the workpiece 11 to the outer edge of the holding surface 12a.

[0072] Next, the workpiece 11 and sheet 19, held by the holding table 12, are machined along the street 13 to form machining marks on the workpiece 11 and sheet 19 (machining step S2). Figure 8 is a cross-sectional view showing the cutting device 2 in machining step S2. Below, as an example, the case in which the workpiece 11 is cut with the machining unit 38A will be described. However, the procedure is the same when the workpiece 11 is cut with the machining unit 38B (see Figure 1).

[0073] In machining step S2, the workpiece 11 is cut along the street 13 using a cutting blade 42 mounted on the machining unit 38A. Specifically, first, the holding table 12 is rotated to align the length of a predetermined street 13 with the X-axis direction (machining feed direction). The position of the machining unit 38A in the Y-axis direction is also adjusted so that the cutting blade 42 is positioned on the extension of the predetermined street 13. Furthermore, the height of the machining unit 38A is adjusted so that the lower end of the cutting blade 42 is positioned below the first surface 11a (upper surface of the sheet 19) of the workpiece 11 and above the holding surface 12a (lower surface of the sheet 19).

[0074] Then, while rotating the cutting blade 42, the holding table 12 is moved along the X-axis. As a result, the holding table 12 and the cutting blade 42 move relative to each other along the X-axis (machining feed), and the cutting blade 42 cuts the workpiece 11 and the sheet 19 along the street 13. As a result, machining marks (kerfs) 23 are formed on the workpiece 11 and the sheet 19 along the street 13.

[0075] The machining marks 23 are formed so as to extend from the second surface 11b to the first surface 11a of the workpiece 11. This divides the workpiece 11 along the street 13. The machining marks 23 are also formed on the upper surface of the sheet 19 and remain as machining grooves with a depth less than the thickness of the sheet 19. The same procedure is then repeated to cut the workpiece 11 and the sheet 19 along the other streets 13.

[0076] During the cutting of the workpiece 11, a liquid such as pure water (cutting fluid) is supplied to the workpiece 11 and the cutting blade 42. This cools the workpiece 11 and the cutting blade 42, and washes away the debris (machining chips) generated by cutting the workpiece 11.

[0077] Figure 9 is a plan view showing the workpiece 11 and sheet 19 after machining step S2. When the workpiece 11 and sheet 19 are cut as described above, machining marks 23 are formed along the street 13. The machining marks 23 include a first machining mark 23a formed on the workpiece 11 and a second machining mark 23b formed on the sheet 19 and located on the extension of the first machining mark 23a.

[0078] The first machining mark 23a is formed on the workpiece 11 from the second surface 11b to the first surface 11a. Once the first machining mark 23a is formed on the workpiece 11, the workpiece 11 is divided and fragmented along the street 13. As a result, the workpiece 11 is divided into multiple chips (device chips) 25, each containing a device 15.

[0079] Furthermore, outside the outer peripheral edge of the workpiece 11, a second processing mark 23b remains, formed in the holding area 19a (see Figure 7) of the sheet 19. The second processing mark 23b corresponds to the end of the processing mark formed on the sheet 19 in processing step S2, and is exposed upward on the outside of the outer peripheral edge of the workpiece 11.

[0080] Next, the processed workpiece 11 and sheet 19 held by the holding table 12 are imaged (imaging step S3). Imaging step S3 corresponds to the imaging method according to the embodiment.

[0081] Figure 10 is a cross-sectional view showing the cutting apparatus 2 in imaging step S3. Imaging step S3 includes a first imaging step S31 in which an imaging unit 14 (first imaging unit) images a first machining mark 23a formed in a first region 21A of the workpiece 11, and a second imaging step S32 in which an imaging unit 44 (second imaging unit) images a second machining mark 23b located on the extension of the first machining mark 23a formed in a second region 21B of the workpiece 11.

[0082] In the first imaging step S31, the holding table 12 and the imaging unit 14 are first moved by the moving units 66 and 90 (see Figure 3) as described above, thereby positioning the imaging unit 14 below the holding table 12 (imaging space 64d in Figure 3). At this time, the positional relationship between the holding table 12 and the imaging unit 14 is adjusted so that the imaging unit 14 aligns with the opening 62d of the holding member 60 and the frame 62 in the Z-axis direction.

[0083] Then, the imaging unit 14 images the processing marks 23 (first processing marks 23a) formed on the first region 21A of the workpiece 11 from the first surface 11a side of the workpiece 11 via the holding member 60. Since the sheet 19 and the holding member 60 are transparent to the light received by the imaging unit 14, the imaging unit 14 can image the first surface 11a side of the workpiece 11 via the sheet 19 and the holding member 60. As a result, an image of the first surface 11a side of the workpiece 11 is acquired.

[0084] Figure 11(A) is a diagram showing an image 130A acquired by the imaging unit 14. When the imaging unit 14 images the first surface 11a of the workpiece 11, an image 130A is acquired that includes the device 15, the first machining mark 23a, etc., formed on the workpiece 11. The imaging unit 14 then outputs the image 130A generated by the imaging to the controller 54 (see Figure 10).

[0085] There are no restrictions on the specific imaging method of the workpiece 11 by the imaging unit 14. For example, in the first imaging step S31, the entire first region 21A of the workpiece 11 may be imaged in a single imaging, or the first region 21A of the workpiece 11 may be imaged multiple times while the holding table 12 and the imaging unit 14 are moved relative to each other along the XY plane. Alternatively, either a low-magnification image or a high-magnification image of the first region 21A may be acquired using one of the cameras 120A or 120B provided in the imaging unit 14, or both low-magnification and high-magnification images of the first region 21A may be acquired using both cameras 120A and 120B.

[0086] In the second imaging step S32, the holding table 12 and the imaging unit 44 are first moved by the moving unit 20A (see Figure 1) and the moving unit 66 (see Figure 3) to position the imaging unit 44 above the holding table 12. At this time, the positional relationship between the holding table 12 and the imaging unit 44 is adjusted so that the imaging unit 44 can image the area 19a of the sheet 19.

[0087] Then, the imaging unit 44 images the held area 19a of the sheet 19. The imaging unit 44 is equipped with a camera capable of imaging the sheet 19, and by imaging the sheet 19 with the imaging unit 44, an image of the processing marks 23 (second processing marks 23b) formed on the upper surface side of the held area 19a of the sheet 19 is acquired.

[0088] Figure 11(B) is an image diagram showing the image 130B acquired by the imaging unit 44. When the imaging unit 44 images the held area 19a of the sheet 19, an image 130B is acquired that includes the second processing marks 23b etc. formed on the held area 19a of the sheet 19. The imaging unit 44 then outputs the image 130B generated by the imaging to the controller 54 (see Figure 10).

[0089] The controller 54 outputs a control signal to the display unit 52, causing the display unit 52 to display images 130A and 130B. This allows the operator to confirm the position, shape, etc., of the machining marks 23 formed on the workpiece 11 and the sheet 19.

[0090] In order to accurately evaluate the suitability of the machining applied to the workpiece 11, it is desirable to check the location of the machining marks 23 formed on the workpiece 11 after machining across the entire surface of the workpiece 11. In particular, when the workpiece 11 is divided into multiple chips 25, it is necessary to check the location of the machining marks 23 on the first surface 11a side of the workpiece 11 in order to evaluate whether the cutting blade 42 is properly cutting along the street 13 between adjacent devices 15.

[0091] However, while the imaging unit 14 can image the first region 21A of the workpiece 11, it cannot image the second region 21B. Therefore, the imaging unit 14 alone cannot image the entire first surface 11a side of the workpiece 11.

[0092] Furthermore, in order to enable the imaging unit 14 to image the entire area of ​​the first surface 11a side of the workpiece 11, it is also conceivable to configure the holding table 12 so that the entire workpiece 11 overlaps with the opening 62d of the holding member 60 and the frame 62. However, in order to configure the holding table 12 in this way, it is necessary to enlarge the holding member 60 and the frame 62, which would make the holding table 12 larger. As a result, miniaturization of the cutting device 2 would be hindered. In addition, if the layout of each component of the cutting device 2 is precisely set, if the holding table 12 is enlarged, it may become difficult to even mount the holding table 12 on the cutting device 2.

[0093] Therefore, in this embodiment, instead of imaging the processing marks 23 (first processing marks 23a) formed in the second region 21B of the workpiece 11, the processing marks 23 (second processing marks 23b) formed in the holding region 19a of the sheet 19 are imaged. Since the processing marks 23 are formed linearly on the workpiece 11 and the sheet 19 (see Figure 9), the positions of the first processing marks 23a formed in the second region 21B of the workpiece 11 and the second processing marks 23b formed in the holding region 19a of the sheet 19 coincide in the Y-axis direction. Therefore, by confirming the position of the second processing marks 23b formed in the holding region 19a of the sheet 19, the position of the first processing marks 23a formed in the second region 21B of the workpiece 11 can be indirectly identified. As a result, based on the images acquired by the imaging units 14 and 44, it becomes possible to confirm the positions of all processing marks 23 formed on the first surface 11a side of the workpiece 11.

[0094] The machining marks 23 are formed so as to extend from the second surface 11b to the first surface 11a of the workpiece 11. Therefore, by imaging the second surface 11b side of the workpiece 11 with the imaging unit 44 provided above the workpiece 11, the machining marks 23 formed on the workpiece 11 can be imaged. However, for example, during cutting of the workpiece 11, the cutting blade 42 may tilt due to the machining load acting between the workpiece 11 and the cutting blade 42. In this case, a shift occurs in the position of the machining marks 23 between the first surface 11a side and the second surface 11b side of the workpiece 11.

[0095] An example of a misalignment of the first machining mark 23a is shown in Figure 11(B). When the cutting blade 42 is tilted and cuts obliquely into the workpiece 11, even if the first machining mark 23a is formed on the first surface 11a side of the workpiece 11, the first machining mark 23a' appears on the second surface 11b side of the workpiece 11 at a position shifted from the first machining mark 23a. Therefore, even if the first machining mark 23a' is imaged, it is not possible to accurately evaluate whether the first machining mark 23a is formed as intended on the first surface 11a side of the workpiece 11.

[0096] However, a sheet 19, which is cut simultaneously with the workpiece 11, is fixed to the first surface 11a side of the workpiece 11. The second machining mark 23b formed on the sheet 19 remains on the extension of the first machining mark 23a formed on the first surface 11a side of the workpiece 11. Therefore, by confirming the position of the second machining mark 23b formed on the sheet 19, the position of the first machining mark 23a formed on the first surface 11a side of the workpiece 11 can be identified.

[0097] The position of the first processing mark 23a formed on the first surface 11a side of the workpiece 11 can also be determined by imaging all of the second processing marks 23b (see Figure 9) formed on the held area 19a of the sheet 19 with the imaging unit 44 in the second imaging step S32. In this case, the first imaging step S31 can be omitted.

[0098] However, in order to accurately evaluate the position and shape of the machining marks 23 formed on the first surface 11a side of the workpiece 11, it is preferable to directly observe the first surface 11a side of the workpiece 11 as much as possible. Therefore, from the viewpoint of accurately evaluating the machining results of the workpiece 11, it is preferable to image the machining marks 23 formed on the first surface 11a side of the workpiece 11 that can be imaged by the imaging unit 14 with the imaging unit 14, and to use the imaging unit 44 to identify the position of the other machining marks 23.

[0099] As described above, in imaging step S3, the imaging unit 14 images the first surface 11a side of the workpiece 11 (first imaging step S31), and the imaging unit 44 images the held area 19a of the sheet 19 (second imaging step S32), thereby allowing the location of the processing marks 23 formed over the entire first surface 11a side of the workpiece 11 to be identified. Note that in imaging step S3, the second imaging step S32 may be performed after the first imaging step S31, or the first imaging step S31 may be performed after the second imaging step S32. Alternatively, the first imaging step S31 and the second imaging step S32 may be performed sequentially.

[0100] After the imaging step S3 (first imaging step S31 and second imaging step S32), the processing position of the workpiece 11 may be corrected based on the position of the first processing mark 23a captured by the imaging unit 14 and the position of the second processing mark 23b captured by the imaging unit 44 (correction step S4). The correction of the processing position of the workpiece 11 is performed, for example, by the controller 54. Figure 12(A) is a block diagram showing the controller 54, and Figure 12(B) is a schematic diagram showing the method of correcting the processing position.

[0101] The controller 54 includes a processing unit 140 that performs processing necessary for controlling the cutting device 2, and a memory unit 150 that stores various information (data, programs, etc.) used in the processing by the processing unit 140. The memory unit 150 also includes a reference line information storage unit 152 that stores information about a reference line indicating the machining position of the workpiece 11.

[0102] In the cutting device 2, a reference line L (see Figure 12(B)) is set in advance to indicate the position to be machined by the cutting blade 42. The reference line L corresponds to the area that the cutting blade 42 passes through when performing machining feed (see Figure 8) to move the holding table 12 and the machining unit 38A relatively. That is, the reference line L is set along the X-axis so that its position in the Y-axis direction coincides with that of the cutting blade 42. When the workpiece 11 is cut by the holding table 12, the positional relationship between the workpiece 11 and the cutting blade 42 is adjusted so that the reference line L is positioned in the area of ​​the workpiece 11 to be machined.

[0103] However, wear or replacement of the cutting blade 42 can cause a discrepancy between the position of the reference line L and the actual position of the cutting blade 42. In this case, an error occurs between the position where the reference line L is positioned (the planned machining position) and the position where it is actually machined. For example, as shown in Figure 12(B), when cutting a workpiece 11 along the center of the street 13 (the position where the distance from adjacent devices 15 is equal), the workpiece 11 and the cutting blade 42 are positioned so that the reference line L is positioned at the center of the street 13. However, if there is a positional discrepancy between the reference line L and the cutting blade 42, the machined area will be shifted from the reference line L, and the positions of the reference line L and the machined marks 23 will not coincide.

[0104] Therefore, in correction step S4, the position of the reference line L is corrected so that the error between the position of the reference line L and the position where the work is actually performed is reduced. A specific example of the processing of the controller 54 for correcting the reference line L will be described below. As shown in Figure 12(A), the processing unit 140 of the controller 54 includes a processing mark identification unit 142 that identifies the position of the processing marks 23, a deviation amount calculation unit 144 that calculates the amount of deviation of the processing position, and a correction unit 146 that corrects the reference line L.

[0105] Images 130A and 130B of the processing marks 23 acquired by the imaging units 14 and 44 are input to the processing mark identification unit 142. The processing mark identification unit 142 then identifies the location of the processing marks 23 based on images 130A and 130B. For example, the processing mark identification unit 142 identifies the processing marks 23 contained in images 130A and 130B by applying image processing such as edge detection to images 130A and 130B. The processing mark identification unit 142 also calculates the coordinates of the processing marks 23 by referring to the positional relationship between the workpiece 11 and the imaging units 14 and 44 when images 130A and 130B were acquired. However, there are no restrictions on the method of identifying the location of the processing marks 23. For example, an operator may identify the location of the processing marks 23 by referring to images 130A and 130B and input it to the processing mark identification unit 142. The processing mark identification unit 142 then outputs the location of the processing marks 23 to the displacement amount calculation unit 144.

[0106] The displacement calculation unit 144 calculates the displacement of the machining position based on the position of the machining marks 23. Specifically, the displacement calculation unit 144 reads the information of the reference line L stored in the reference line information storage unit 152 and calculates the difference between the position of the machining marks 23 and the position of the reference line L. This calculates the displacement ΔY (see Figure 12(B)) between the planned machining position (position of the reference line L) and the actually machined position (position of the machining marks 23). The displacement calculation unit 144 then outputs the calculated displacement ΔY to the correction unit 146.

[0107] The correction unit 146 corrects the reference line L based on the displacement amount ΔY. Specifically, the correction unit 146 reads the reference line L information stored in the reference line information storage unit 152 and changes the position of the reference line L by the displacement amount ΔY so that the position of the reference line L matches the position of the machining mark 23 (see Figure 12(B)). This corrects the position of the reference line L to the actual machining position. Then, the correction unit 146 overwrites the information in the reference line information storage unit 152 with information indicating the corrected position of the reference line L.

[0108] As described above, the position of the reference line L is corrected based on the images 130A and 130B acquired by the imaging units 14 and 44. Then, when processing the workpiece 11, the workpiece 11 and the cutting blade 42 are aligned so that the corrected reference line L is positioned in the area of ​​the workpiece 11 to be processed. This suppresses the error between the planned processing position and the actual processing position of the workpiece 11, improving processing accuracy.

[0109] The holding step S1 to the correction step S4 described above are achieved by executing a program stored in the controller 54. Specifically, the storage unit 150 of the controller 54 stores a program that describes the process of operating each component of the cutting device 2 so that each of the above steps is executed. When the controller 54 reads and executes the above program, control signals are sequentially output from the controller 54 to each component of the cutting device 2, and the holding step S1 to the correction step S4 are executed automatically.

[0110] As described above, in the cutting apparatus 2 and workpiece processing method according to this embodiment, the first processing mark 23a formed in the first region 21A of the workpiece 11 is imaged by the imaging unit 14 from the first surface 11a side of the workpiece 11 via the holding member 60, and the second processing mark 23b, which is located on the extension of the first processing mark 23a formed in the second region 21B of the workpiece 11, is imaged by the imaging unit 44. As a result, the position of the processing marks 23 formed on the first surface 11a side of the workpiece 11 can be identified over the entire area of ​​the workpiece 11 without changing the configuration of the holding table 12.

[0111] In the above embodiment, a cutting device 2 (see Figure 1) was described as an example of a processing device, but there are no limitations on the type of processing device according to the present invention. For example, the processing device according to the present invention may be a laser processing device that performs laser processing on a workpiece 11.

[0112] The laser processing apparatus comprises a holding table for holding the workpiece 11 and a processing unit (laser irradiation unit) for irradiating the workpiece 11 with a laser beam to perform laser processing. For example, the laser irradiation unit comprises a laser oscillator and an optical system for guiding the pulsed laser beam emitted from the laser oscillator to the workpiece 11. The optical system is composed of multiple optical elements such as mirrors for reflecting the laser beam and focusing lenses for focusing the laser beam at predetermined positions. Also, similar to the cutting apparatus 2, the laser processing apparatus is equipped with a first imaging unit, a second imaging unit, a display unit, a controller, etc.

[0113] When processing the workpiece 11 with the laser processing device, for example, in processing step S2, a laser beam with a wavelength that is absorbed by the workpiece 11 and the sheet 19 is irradiated from the laser irradiation unit along the street 13 onto the workpiece 11 and the sheet 19. This causes ablation processing on the workpiece 11 and the sheet 19, and processing marks 23 are formed on the workpiece 11 (see Figure 9). Subsequently, similar to the cutting device 2, the imaging step S3 and correction step S4 are performed in the laser processing device. This identifies the position of the processing marks 23 formed on the first surface 11a side of the workpiece 11, and then corrects the processing position of the workpiece 11.

[0114] Furthermore, the structures, methods, etc., according to the above embodiments can be modified as appropriate without departing from the scope of the objectives of the present invention. [Explanation of Symbols]

[0115] 11 Workpiece 11a 1st side (front) 11b 2nd side (back side) 13th Street (planned division line) 15 devices 17 frames 17a aperture 19 seats 19a Retained area 21A 1st area 21B 2nd area 23. Processing marks (calfskin) 23a,23a´ 1st machining mark 23b 2nd machining mark 25 chips (device chips) 2 Cutting equipment 4 base 4a,4b,4c opening 6 Cassette support stand 8 cassettes 10 Holding Units 12. Holding table (chuck table) 12a Holding surface 14 Imaging Unit 16 Dustproof and splashproof cover 18 Support structure 20A, 20B Mobile Unit 22 Y-axis guide rail 24A, 24B Y-axis moving plate 26A, 26B Y-axis ball screw 28 Y-axis pulse motor 30A, 30B Z-axis guide rail 32A, 32B Z-axis moving plate 34A, 34B Z-axis ball screw 36A, 36B Z-axis pulse motor 38A, 38B Machining Unit (Cutting Unit) 40 spindles 42 Cutting Blades 44 imaging units 46 Washing Unit 48 Spinner Table 48a Holding surface 50 nozzles 52 Display unit (display unit, display device) 54 Controller (control unit, control unit, control device) 60 Retaining member 60a 1st side (top side) 60b 2nd side (bottom side) 62 Frame 62a 1st side (top side) 62b 2nd side (bottom side) 62c Storage section (recess) 62d aperture 64 Mobile Tables 64a bottom plate 64b side plate 64cm tabletop 64d imaging space 66 Mobile Units 68 X-axis guide rail 70 X-axis ball screw 72 X-axis pulse motor 74 Pulley 76 Rotary drive source 78 Pulley 80 Connecting member 90 Mobile Units 92 Y-axis movement mechanism 94 Y-axis movable plate 96 Y-axis guide rail 98 Y-axis ball screw 100 Y-axis pulse motor 102 Z-axis movement mechanism 104 Support structure 106 Z-axis guide rail 108 Z-axis movement plate 110 Z-axis ball screw 112 Z-axis pulse motor 114 Support Arm 120A, 120B Camera 122A,122B Lighting Image 130A, 130B 140 Processing Unit 142 Machining mark identification part 144 Calculation unit for displacement 146 Correction section 150 Memory Unit 152 Reference Line Information Storage Unit

Claims

1. A processing apparatus for processing a workpiece having a first surface and a second surface, with a sheet fixed to the first surface side, A holding table that holds the first surface side of the workpiece, A processing unit that processes the workpiece and the sheet held by the holding table along a street, thereby forming a first processing mark on the workpiece extending from the second surface to the first surface, and forming a second processing mark on the sheet located on the extension of the first processing mark, A first imaging unit for imaging the first processing mark, The system comprises a second imaging unit for imaging the second processing mark, The holding table holds the workpiece and the sheet by a holding member that is transparent to light received by the first imaging unit, and a frame that supports the outer periphery of the holding member. The first imaging unit images the first processing marks formed in an area of ​​the workpiece that does not overlap with the frame, from the first surface side of the workpiece via the holding member. The second imaging unit is a processing apparatus that images the second processing mark located on the extension of the first processing mark formed in the region of the workpiece that overlaps with the frame.

2. The processing apparatus according to claim 1, further comprising a controller that corrects the processing position of the workpiece by the processing unit based on the position of the first processing mark captured by the first imaging unit and the position of the second processing mark captured by the second imaging unit.

3. A method for processing a workpiece having a first surface and a second surface, with a sheet fixed to the first surface side, A holding step comprising a holding table having a holding member that is transparent to light received by a first imaging unit and a frame that supports the outer periphery of the holding member, wherein the first surface side of the workpiece is held, A processing step comprising processing the workpiece and the sheet held by the holding table along the street, thereby forming a first processing mark on the workpiece extending from the second surface to the first surface, and forming a second processing mark on the sheet located on the extension of the first processing mark, A first imaging step involves imaging the first processing marks formed in a region of the workpiece that does not overlap with the frame body, from the first surface side of the workpiece via the holding member using the first imaging unit, A method for processing a workpiece, comprising: a second imaging step of imaging a second processing mark located on the extension of a first processing mark formed in a region of the workpiece that overlaps with the frame of the workpiece, using a second imaging unit.

4. A method for processing a workpiece according to claim 3, further comprising a correction step after the first imaging step and the second imaging step, for correcting the processing position of the workpiece based on the position of the first processing mark captured by the first imaging unit and the position of the second processing mark captured by the second imaging unit.

Images