Processing apparatus, information acquisition method, and processing method

Abstract

The present invention provides a machining apparatus that can achieve sufficiently high machining accuracy even when alignment is performed using an imaging unit positioned to the side of the machining unit. [Solution] The processing apparatus includes a holding table having a holding plate that transmits light in at least a portion thereof, a holding table that holds a workpiece on the first surface side of the holding plate, a processing unit that processes the workpiece held by the holding table, a moving mechanism that moves the holding table and the processing unit relative to each other along a first direction parallel to the first surface, a rotating mechanism that rotates the holding table about a rotation axis along a second direction perpendicular to the first surface, a first imaging unit which is positioned at least a distance away from the processing unit in the first direction and images the area on the first surface side of the holding plate, a second imaging unit which is positioned along a straight line passing through the processing unit and parallel to the second direction and images the area on the first surface side of the holding plate, and a control unit.

Description

Technical Field

[0001] The present invention relates to a processing apparatus for processing a workpiece, an information acquisition method for acquiring information used when processing the workpiece, and a processing method for processing the workpiece using the acquired information.

Background Art

[0002] In electronic devices represented by mobile phones and personal computers, a device chip having devices such as electronic circuits is an essential component. The device chip is obtained, for example, by partitioning the surface side of a wafer made of silicon or the like into a plurality of small regions by a linear processing planned line (street), forming devices in each small region, and then dividing the wafer along this processing planned line.

[0003] When dividing a wafer as described above into a plurality of device chips, for example, a cutting apparatus having a processing unit (cutting unit) equipped with a processing tool called a cutting blade is used (see, for example, Patent Document 1). By rotating the cutting blade at high speed and making a cut in the wafer at the processing planned line while supplying a liquid such as water, the wafer is cut along the processing planned line and divided into a plurality of device chips.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] ​​​​​​​​​​​​​​The cutting apparatus described above typically includes an imaging unit (camera) fixed to the side of the processing unit, and uses this imaging unit to image areas containing characteristic patterns, for example, caused by devices within the wafer. By identifying the position of the pattern relative to the cutting apparatus from the obtained image, the cutting apparatus can adjust the position and orientation of the planned processing line based on the position of this pattern (alignment), thereby processing the wafer with high precision.

[0006] Incidentally, since the purpose of this alignment is to adjust the position and orientation of the planned machining line relative to the machining unit, ideally the alignment should be performed based on the relative position of the machining unit with respect to the table holding the wafer. On the other hand, in a typical cutting machine, as mentioned above, the area within the wafer directly beneath the machining unit is imaged using an imaging unit located to the side of the machining unit, so the alignment is performed based on the relative position of the imaging unit with respect to the table.

[0007] Although the movement mechanism that moves the processing unit and imaging unit relative to the table is constructed with extremely high precision, it may not be possible to completely eliminate slight errors (yawing) that could unintentionally rotate the table. Therefore, the orientation of the processing line when any part of the processing line is being processed—that is, the orientation of the processing line when the processing unit is positioned directly above that part—may deviate slightly from the orientation of the processing line resulting from alignment performed when the processing unit is not positioned directly above that part, potentially leading to insufficient precision in wafer processing.

[0008] Therefore, the object of the present invention is to provide a processing apparatus, an information acquisition method, and a processing method that can achieve sufficiently high processing accuracy even when alignment is performed using an imaging unit located to the side of the processing unit. [Means for solving the problem]

[0009] According to one aspect of the present invention, a processing apparatus for processing a workpiece comprises: a holding table having a holding plate that transmits light in at least a portion thereof, and configured to hold the workpiece on the first surface side of the holding plate; a processing unit configured to process the workpiece held by the holding table; a moving mechanism configured to move the holding table and the processing unit relative to each other along a first direction parallel to the first surface; a rotating mechanism configured to rotate the holding table about a rotation axis along a second direction perpendicular to the first surface; and a second sensor configured to image the region of the holding plate on the first surface side, with a portion of it positioned at least in the first direction away from the processing unit. A processing apparatus is provided, comprising: an imaging unit; a second imaging unit, a portion of which is positioned on the second surface side of the holding plate opposite to the first surface, along a straight line passing through the processing unit and parallel to the second direction, and configured to be able to image the area on the first surface side of the holding plate; and a control unit, wherein the control unit acquires two images by imaging the same target area on the first surface side of the holding plate with the first imaging unit and the second imaging unit, by moving the holding table along the first direction without the rotation mechanism rotating the holding table; and from these two images, angle information representing the orientation of the holding table around the rotation axis when the target area is imaged by the first imaging unit is obtained, with the orientation of the holding table around the rotation axis when the target area is imaged by the second imaging unit as the reference.

[0010] Preferably, the first surface of the holding plate is provided with a groove for applying negative pressure to the workpiece when holding the workpiece, and the first imaging unit and the second imaging unit image the target area including the groove.

[0011] Preferably, when the processing unit processes the workpiece held by the holding table using an image obtained by the first imaging unit, the control unit adjusts the orientation of the holding table around the rotation axis using the angle information.

[0012] Furthermore, the processing unit may have a spindle on which a processing tool to be brought into contact with the workpiece is mounted, or a light concentrator to focus a laser beam onto the workpiece, and a portion of the second imaging unit may be arranged along the straight line passing through the processing tool or the light concentrator.

[0013] According to another aspect of the present invention, an information acquisition method for acquiring information for adjusting the orientation of a holding table provided in a processing apparatus, wherein the processing apparatus includes a holding table having a holding plate that at least a portion of which transmits light, and configured to hold a workpiece on the first surface side of the holding plate; a processing unit configured to process the workpiece held by the holding table; a moving mechanism configured to move the holding table and the processing unit relative to each other along a first direction parallel to the first surface; a rotating mechanism configured to rotate the holding table about a rotation axis along a second direction perpendicular to the first surface; and imaging the region of the holding plate on the first surface side, where a portion of the holding plate is positioned at least in the first direction away from the processing unit. An information acquisition method is provided, comprising: a first imaging unit configured to enable imaging; a second imaging unit positioned on the second surface side of the holding plate opposite to the first surface, with a portion of it arranged along a straight line parallel to the second direction passing through the processing unit, and configured to enable imaging of the area on the first surface side of the holding plate; an image acquisition step of acquiring two images by having the first imaging unit and the second imaging unit image the same target area on the first surface side of the holding plate by moving the holding table along the first direction without the rotation mechanism rotating the holding table; and an angle information acquisition step of acquiring angle information from the two images, with reference to the orientation of the holding table around the rotation axis when the target area is imaged by the second imaging unit, to represent the orientation of the holding table around the rotation axis when the target area is imaged by the first imaging unit.

[0014] Preferably, the first surface of the holding plate is provided with a groove for applying negative pressure to the workpiece when holding the workpiece, and in the image acquisition step, the first imaging unit and the second imaging unit image the target area including the groove.

[0015] According to yet another aspect of the present invention, a processing method is provided for processing a workpiece using the information acquisition method described above, further comprising: a processing step after the angle information acquisition step, in which the workpiece held by the holding table is imaged by the first imaging unit and the workpiece is processed by the processing unit using the image obtained, wherein in the processing step the workpiece is processed with the orientation of the holding table around the rotation axis adjusted using the angle information. [Effects of the Invention]

[0016] In a processing apparatus relating to one aspect of the present invention, an information acquisition method relating to another aspect, and a processing method relating to yet another aspect, angular information representing the orientation of the holding table around the rotation axis when the target area is imaged by the first imaging unit is obtained from an image acquired by a first imaging unit, part of which is positioned away from the processing unit in a first direction parallel to the first surface of the holding table, and an image acquired by a second imaging unit, part of which is positioned parallel to a second direction perpendicular to the first surface of the holding table and along a straight line passing through the processing unit, with reference to the orientation of the holding table around the rotation axis when the target area is imaged by the second imaging unit.

[0017] Therefore, when performing alignment using the first imaging unit, the orientation of the holding table can be adjusted using the acquired angle information to bring the orientation of the holding table closer to the orientation of the holding table when performing alignment using the second imaging unit. Thus, according to each aspect of the present invention, even when performing alignment using an imaging unit located on the side of the processing unit, sufficiently high processing accuracy can be achieved. [Brief explanation of the drawing]

[0018] [Figure 1] FIG. 1 is a perspective view schematically showing the structure of a cutting apparatus according to an embodiment. [Figure 2] FIG. 2 is a perspective view schematically showing the structure of a workpiece according to an embodiment. [Figure 3] FIG. 3 is a perspective view schematically showing a part of the cutting apparatus. [Figure 4] FIG. 4 is a cross-sectional view schematically showing a part of the cutting apparatus. [Figure 5] FIG. 5 is a flowchart showing a processing method including an information acquisition method according to an embodiment. [Figure 6] FIG. 6 is a cross-sectional view showing a state where a holding plate is imaged by a second imaging unit. [Figure 7] FIG. 7 is a diagram showing an example of an image obtained by a second imaging unit. [Figure 8] FIG. 8 is a cross-sectional view showing a state where a holding plate is imaged by a first imaging unit. [Figure 9] FIG. 9 is a diagram showing an example of an image obtained by a first imaging unit.

MODE FOR CARRYING OUT THE INVENTION

[0019] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view schematically showing the structure of a cutting apparatus (processing apparatus) 2 according to the present embodiment. In FIG. 1, some elements are represented by functional blocks. Further, the X-axis (front-rear axis), Y-axis (left-right axis), and Z-axis (vertical axis) used in the following description are perpendicular to each other.

[0020] As shown in FIG. 1, the cutting apparatus 2 includes a base 4 that supports various elements. An opening 4a is formed at a corner of the upper surface of the base 4, and a cassette table 6 that moves up and down by a lifting mechanism (not shown) is disposed in the opening 4a. A cassette 8 that can accommodate a plate-shaped workpiece 11 is placed on the upper surface of the cassette table 6. In FIG. 1, only the outline of the cassette 8 is shown for convenience of explanation.

[0021] Figure 2 is a schematic perspective view showing the structure of the workpiece 11. The workpiece 11 is typically a disc-shaped wafer made of a semiconductor such as silicon (Si), and has a circular first surface (front) 11a and a circular second surface (back) 11b opposite to the first surface 11a. The first surface 11a side of the workpiece 11 is divided into multiple small regions by multiple intersecting linear processing lines (streets) 13, and a device 15 such as an IC (Integrated Circuit) is formed in each small region.

[0022] In this embodiment, a support (or protective) member (not shown), such as a resin tape, is attached to the first surface 11a or the second surface 11b of the workpiece 11. It is desirable that this member be configured to transmit light of a predetermined wavelength (visible light and / or infrared light). If a member with a larger diameter than the workpiece 11 is attached to the workpiece 11, an annular frame may be fixed to the outer edge of this member.

[0023] In this embodiment, a disc-shaped wafer made of a semiconductor such as silicon is exemplified as the workpiece 11, but the material, shape, structure, size, etc. of the workpiece 11 are not limited to this embodiment. For example, a substrate made of other semiconductors, ceramics, resins, metals, etc. may be used as the workpiece 11. Similarly, the type, quantity, shape, structure, size, arrangement, etc. of the devices 15 are not limited to the above embodiment. The workpiece 11 does not need to have devices 15 formed on it. Also, the workpiece 11 does not need to have any supporting (or protective) members attached to it.

[0024] An elongated opening 4b is formed along the X-axis (first direction) adjacent to the cassette table 6 along the Y-axis. Figure 3 is a schematic perspective view showing a part of the structure inside the opening 4b of the cutting device 2, and Figure 4 is a schematic cross-sectional view showing a part of the structure inside the opening 4b of the cutting device 2.

[0025] As shown in Figures 3 and 4, a ball screw type table moving mechanism (machining feed mechanism, first moving mechanism) 10 is arranged inside the opening 4b. The table moving mechanism 10 has a pair of long X-axis guide rails 12 fixed to, for example, the frame that constitutes the base 4 and along the X-axis. The X-axis moving part 14 that constitutes the table moving mechanism 10 is attached to the X-axis guide rails 12 in such a manner that it can slide along the X-axis.

[0026] The X-axis moving section 14 includes a flat bottom plate 14a whose shape is rectangular when viewed from the direction along the Z-axis (second direction). One end of the bottom plate 14a in the direction along the Y-axis is connected to the lower end of a flat side plate 14b whose shape is rectangular when viewed from the direction along the Y-axis (third direction). One end of a flat top plate 14c, whose shape is rectangular in the direction along the Y-axis and is the same as that of the bottom plate 14a when viewed from the direction along the Z-axis, is connected to the upper end of the side plate 14b.

[0027] In other words, one end of the base plate 14a along the Y-axis and one end of the top plate 14c along the Y-axis are connected to each other via the side plate 14b. A space 14d is formed between the base plate 14a and the top plate 14c that connects to the outside at the other end along the Y-axis and at both ends along the X-axis.

[0028] A nut portion 14e (Figure 4, etc.) constituting a ball screw is provided on the lower surface of the bottom plate 14a of the X-axis moving part 14. A long screw shaft 16 along the X axis is connected to this nut portion 14e in a manner that allows it to rotate via a plurality of small balls (not shown). A rotational drive source 18, such as a motor, is connected to the end of the screw shaft 16.

[0029] Therefore, by rotating the screw shaft 16 with the rotary drive source 18, the X-axis moving part 14 moves along the longitudinal direction of the X-axis guide rail 12, that is, along the X-axis. For example, a position sensor (not shown) is provided next to the X-axis guide rail 12, and this position sensor detects the position of the X-axis moving part 14 in the direction along the X-axis.

[0030] A table (holding table, chuck table) 20 is positioned on the upper surface of the top plate 14c of the X-axis moving section 14, configured to hold the workpiece 11 described above. This table 20 is supported on the top plate 14c via bearings (not shown), such as thrust bearings, so that it can rotate around a rotation axis that is roughly parallel to the Z-axis. In other words, the table 20 is supported by the X-axis moving section 14.

[0031] The table 20 includes a cylindrical frame 22 made of a metal, such as stainless steel. The lower end portion of a space 22a located inside the frame 22 is connected to an opening 14f that penetrates the tabletop 14c vertically. A disc-shaped retaining plate 24 is fixed to the upper part of the frame 22 so as to close the upper end of the space 22a.

[0032] The retaining plate 24 has a first surface (upper surface) 24a facing upward and a second surface (lower surface) 24b facing in the opposite direction (downward) from the first surface 24a, and is formed using a material that transmits light of a predetermined wavelength (visible light and / or infrared light), such as soda glass, borosilicate glass, or quartz glass. This retaining plate 24 is transparent to the aforementioned light in at least a portion of the area from the first surface 24a to the second surface 24b.

[0033] Therefore, the workpiece 11 held on the first surface 24a of the holding plate 24 can be observed from below the top plate 14c. In this embodiment, a holding plate 24 that is almost entirely transparent is illustrated, but it is sufficient that at least a part of the holding plate 24 is transparent from the first surface 24a to the second surface 24b. In other words, the holding plate 24 does not necessarily have to be made only of transparent material. The first surface 24a and the second surface 24b of this holding plate 24 are approximately perpendicular to the rotation axis of the table 20, that is, to the Z-axis.

[0034] For example, the frame 22 is provided with a flow path (not shown) that transmits negative pressure used for suction of the workpiece 11. The upper end of a groove 24c connected to one end of this flow path is open on the first surface 24a of the holding plate 24. A suction source (not shown) for generating negative pressure is connected to the other end of the flow path via a valve (not shown), etc. Therefore, when the valve is opened while the suction source is operating, negative pressure acts on the upper end of the groove 24c. As the suction source, for example, a vacuum pump combining an air supply source and an ejector can be used.

[0035] In this embodiment, a groove 24c with a cross shape when viewed from the direction along the Z-axis is exemplified, but the shape of the groove formed in the holding plate 24 is not limited to this embodiment. For example, the groove may include an annular (circular) portion as well as a linear portion when viewed from the direction along the Z-axis. However, as will be described later, when imaging the groove 24c in order to adjust the orientation of the table 20, it is desirable that the groove 24c include at least a part of a shape that allows for the identification of the rotation of the table 20, such as a linear portion.

[0036] As shown in Figure 3, a pulley 26 with a larger diameter than the frame 22 is fixed to the outer surface of the frame 22. A rotational drive source 28, such as a motor, is provided on the side plate 14b of the X-axis moving section 14, and a pulley 30 is connected to the rotating shaft of this rotational drive source 28. An endless belt 32 is wrapped around the pulleys 26 and 30 to transmit the power of the rotational drive source 28 to the table 20.

[0037] Therefore, the table 20 rotates around a rotation axis that is roughly parallel to the Z axis by force transmitted from the rotation drive source 28 via the belt 32. That is, the pulley 26, rotation drive source 28, pulley 30, and belt 32 constitute a rotation mechanism 33 that rotates the table 20 around a rotation axis along the Z axis. Furthermore, the table 20 moves along the X axis together with the X axis moving part 14, etc., by the table moving mechanism 10 described above (machining feed). The table moving mechanism 10, table 20, etc. described above are also part of the imaging unit, which is characteristic of this embodiment.

[0038] In this embodiment, a belt drive system is exemplified as a method for rotating the table 20, in which power from the rotational drive source 28 is transmitted to the table 20 via a belt 32. However, any other method may be adopted. For example, as another method for rotating the table 20, a Direct Drive Motor (DDM) system may be adopted, in which the rotation shaft of the motor is directly connected to the table 20 without the use of intermediate mechanisms such as a belt 32 or a reduction gear.

[0039] As shown in Figure 1, the upper part of the table moving mechanism 10 is covered by covers 34a, 34b, 34c, and 34d, etc., which are positioned to close the opening 4b. For example, flat covers 34a and 34b are attached to both ends of the tabletop 14c in the direction along the Y axis. Also, for example, bellows-shaped covers 34c and 34d, which expand and contract in accordance with the movement of the X-axis moving part 14 along the X axis, are attached to both ends of the tabletop 14c in the direction along the X axis.

[0040] Above the opening 4b, one or more transport mechanisms (not shown) are arranged that can transport the workpiece 11 to the table 20 or the like. The transport mechanism, for example, unloads the workpiece 11 from the cassette 8 and loads the workpiece 11 into the table 20, which is located in the loading / unloading area in front of the cassette 8 (cassette table 6). The workpiece 11 is placed on the first surface 24a of the table 20 such that, for example, the first surface 11a or the second surface 11b, to which a support (or protective) member is attached, faces downward.

[0041] A cantilevered support structure 36 is positioned adjacent to the rear portion of the opening 4b along the Y-axis. A machining unit movement mechanism (indexing feed mechanism, cutting feed mechanism) 38 is positioned on top of the support structure 36. This machining unit movement mechanism 38 is fixed to the front of the support structure 36 and has a pair of long Y-axis guide rails 40 along the Y-axis.

[0042] A Y-axis moving plate 42, which constitutes the machining unit moving mechanism 38, is mounted on the Y-axis guide rail 40 in a manner that allows it to slide along the Y-axis. A nut portion (not shown) that constitutes a ball screw is provided on the back side of the Y-axis moving plate 42, and a long screw shaft 44 is connected to this nut portion in a manner that allows it to rotate along the Y-axis via a plurality of small balls (not shown).

[0043] A rotational drive source (not shown), such as a motor, is connected to the end of the screw shaft 44. Therefore, when the screw shaft 44 is rotated by the rotational drive source, the Y-axis moving plate 42 moves along the longitudinal direction of the Y-axis guide rail 40, that is, along the Y-axis. For example, a position sensor (not shown) is provided next to the Y-axis guide rail 40, and this position sensor detects the position of the Y-axis moving plate 42 in the direction along the Y-axis.

[0044] A pair of long Z-axis guide rails 46 are fixed to the front of the Y-axis moving plate 42 along the Z-axis. The Z-axis moving plate 48 is mounted on the pair of Z-axis guide rails 46 in a manner that allows it to slide along the Z-axis. A nut portion (not shown) that constitutes a ball screw is provided on the back side of the Z-axis moving plate 48, and a long screw shaft 50 along the Z-axis is connected to this nut portion in a manner that allows it to rotate via a plurality of small balls (not shown).

[0045] A rotational drive source 52, such as a motor, is connected to the end of the screw shaft 50. Therefore, when the screw shaft 50 is rotated by the rotational drive source 52, the Z-axis moving plate 48 moves along the longitudinal direction of the Z-axis guide rail 46, that is, along the Z-axis. For example, a position sensor (not shown) is provided next to the Z-axis guide rail 46, and this position sensor detects the position of the Z-axis moving plate 48 in the direction along the Z-axis.

[0046] A machining unit (cutting unit) 54 is fixed to the lower part of the Z-axis moving plate 48. The machining unit 54 is equipped with a cylindrical spindle housing 56. A portion of a cylindrical spindle 58 (Figure 4, etc.), which serves as the axis of rotation along the Y-axis, is housed in the space inside the spindle housing 56.

[0047] The tip of the spindle 58 is exposed to the outside of the spindle housing 56. An annular cutting blade (a machining tool) 60, obtained by, for example, solidifying abrasive grains such as diamond with a binder such as resin, is mounted on the tip of the spindle 58. A rotational drive source (not shown), such as a motor, is connected to the base end of the spindle 58. Therefore, when the spindle 58 is rotated by the rotational drive source, the cutting blade 60 rotates around a rotation axis along the Y axis.

[0048] Furthermore, a nozzle 61 is positioned next to the cutting blade 60 to supply a liquid (processing fluid) such as water to the workpiece 11 and the cutting blade 60. When processing the workpiece 11, the liquid is supplied from this nozzle 61 to cool and clean the workpiece 11 and the cutting blade 60.

[0049] A first imaging unit (upper imaging unit, upper camera) 62 is fixed to the lower part of the Z-axis moving plate 48, configured to image the workpiece 11 supported by the table 20 from above. This first imaging unit 62 is positioned away from the machining unit 54 (cutting blade 60) in at least the direction along the X-axis. The machining unit 54 and the first imaging unit 62 are moved along the Y-axis and Z-axis by the machining unit moving mechanism 38.

[0050] The first imaging unit 62 includes, for example, an image sensor (two-dimensional optical sensor) such as a CMOS (Complementary Metal Oxide Semiconductor) image sensor or a CCD (Charge Coupled Device) image sensor, and an imaging lens, and is sensitive to visible light and / or infrared light. Furthermore, the first imaging unit 62 is positioned so that it can receive light incident from below along the Z-axis with the image sensor, i.e., it is positioned downwards. However, the type, structure, arrangement, etc., of the first imaging unit 62 are not limited to this embodiment.

[0051] As shown in Figures 3 and 4, a Y-axis movement mechanism (second movement mechanism) 66, which constitutes a second imaging unit 64 for imaging the workpiece 11 etc. from below, is arranged in the area behind the table movement mechanism 10. The Y-axis movement mechanism 66 has a pair of Y-axis guide rails 68 that are fixed to, for example, the frame that constitutes the base 4 and are long along the Y axis. A Y-axis movement plate 70, which constitutes the Y-axis movement mechanism 66, is attached to the Y-axis guide rails 68 in a manner that allows it to slide along the Y axis.

[0052] A nut portion 72 (Figure 4, etc.) constituting a ball screw is provided on the lower side of the Y-axis moving plate 70. A long screw shaft 74 is connected to this nut portion 72 in a manner that allows it to rotate along the Y-axis via a plurality of small balls (not shown). A rotational drive source 76 (Figure 3), such as a motor, is connected to the end of the screw shaft 74.

[0053] Therefore, by rotating the screw shaft 74 with the rotary drive source 76, the Y-axis moving plate 70 moves along the longitudinal direction of the Y-axis guide rail 68, that is, along the Y-axis. For example, a position sensor (not shown) is provided next to the Y-axis guide rail 68, and this position sensor detects the position of the Y-axis moving plate 70 in the direction along the Y-axis.

[0054] A long support member 78 is fixed to the upper surface of the Y-axis moving plate 70 along the X-axis. A part of the lower imaging unit 80 is fixed to this support member 78, for example. The lower imaging unit 80 includes, for example, a lower camera moving mechanism (third moving mechanism) 82 fixed to the Y-axis moving plate 70 (and the support member 78). The lower camera moving mechanism 82 is an actuator including, for example, a rotational drive source such as a motor, and its movable part 82a can be moved along the X-axis.

[0055] The lower camera 84 is fixed to the movable part 82a of the lower camera movement mechanism 82. The lower camera 84 includes an image sensor (two-dimensional optical sensor) such as a CMOS (Complementary Metal Oxide Semiconductor) image sensor or a CCD (Charge Coupled Device) image sensor, and an imaging lens, and is sensitive to light of wavelengths (visible light and / or infrared light) that pass through the holding plate 24.

[0056] Furthermore, the lower camera 84 is positioned so that it can receive light incident from the front along the X-axis with its image sensor, i.e., it is facing forward. The lower camera 84 moves along the X-axis as the lower camera moving mechanism 82 moves the movable part 82a. However, the type, structure, and arrangement of the lower camera 84 are not limited to this embodiment.

[0057] A reflective section 86 is fixed to a part of the support 78 so as to be aligned with the lower camera 84 along the X-axis and positioned at the same location on the X-axis as the cutting blade 60 (Figure 4, etc.) (i.e., positioned at the same X coordinate). The reflective section 86 includes a hollow reflective section housing 86a. An opening 86b that allows light to pass through is provided at the top of the reflective section housing 86a. A member made of a material that can transmit light of wavelengths that pass through the holding plate 24 may be fitted into this opening 86b.

[0058] Furthermore, a reflective member 86c (Figure 4, etc.) is positioned directly below the opening 86b to reflect light that has passed through the opening 86b. The reflective member 86c is, for example, a prism or a mirror, and reflects light incident downward along the Z-axis toward the lower camera 84 along the X-axis, that is, toward the rear.

[0059] Furthermore, the part of the side of the reflective housing 86a closest to the lower camera 84, that is, the rear part, is open to allow light to pass through. Therefore, light traveling from above toward the reflective unit 86, passing through the opening 86b and entering the reflective member 86c, is reflected by this reflective member 86c and enters the lower camera 84.

[0060] With the lower imaging unit 80 configured in this way, the position of the reflective section 86 is aligned with the table moving mechanism 10 and the Y-axis moving mechanism 66 to be directly below the holding plate 24, so that the lower camera 84 can image the area on the first surface 24a side of the holding plate 24 (the workpiece 11 placed on the first surface 24a side of the holding plate 24, the grooves 24c provided on the first surface 24a side of the holding plate 24, etc.). In other words, the lower imaging unit 80 can image the workpiece 11 placed on the first surface 24a side of the holding plate 24, the grooves 24c provided on the first surface 24a side of the holding plate 24, etc. from the second surface 24b side and acquire an image.

[0061] Furthermore, the lower imaging unit 80 is positioned so that the Y-axis movement mechanism 66 aligns the position of the reflecting part 86 with the cutting blade 60 (processing unit 54). This allows the lower camera 84 to image the area on the first surface 24a side of the holding plate 24 (the processing point of the workpiece 11, the cutting blade 60, the processing unit 54, etc., located on the first surface 24a side of the holding plate 24, as viewed from a position on the second surface 24b side of the holding plate 24, along a straight line perpendicular to the first surface 24a of the holding plate 24 and passing through the cutting blade 60.

[0062] In other words, the lower imaging unit 80 can acquire images by imaging the processing point of the workpiece 11, the cutting blade 60, the processing unit 54, etc., located on the first surface 24a side of the holding plate 24, from the second surface 24b side, while the workpiece 11 is being processed by the cutting blade 60.

[0063] In this embodiment, since the reflective section 86 is fixed to the support 78, the lower camera 84 is moved along the X-axis by the lower camera movement mechanism 82, thereby adjusting the focus of the lower camera 84. For example, a light source (not shown) is placed next to the reflective section 86 that can emit imaging light of a wavelength that passes through the holding plate 24 toward the workpiece 11 above.

[0064] As shown in Figure 1, an opening 4c is formed opposite to opening 4a relative to opening 4b. A cleaning unit 88 for cleaning the workpiece 11 after processing is located inside opening 4c. A controller (control unit) 90 is connected to elements such as the table moving mechanism 10, the rotary drive source 28, one or more transport mechanisms, the processing unit moving mechanism 38, the processing unit 54, the first imaging unit 62, the second imaging unit 64 (Y-axis moving mechanism 66, lower imaging unit 80, etc.), and the cleaning unit 88.

[0065] The controller 90 is composed of a computer including, for example, a processing unit 92 and a storage device 94, and controls the operation of each element of the cutting device 2 described above so that the workpiece 11 is processed appropriately. The processing unit 92 is typically a CPU (Central Processing Unit), GPU (Graphics Processing Unit), NPU (Neural Network Processing Unit), etc., and performs various calculations necessary to control the elements described above.

[0066] The storage device 94 includes, for example, a main memory such as DRAM (Dynamic Random Access Memory) and an auxiliary storage device such as a hard disk drive or flash memory. The functions of the controller 90 are realized by the operation of the processing unit 92 according to the software (programs, data, etc.) stored in the storage device 94.

[0067] A touchscreen (input / output device, input device, output device) 96, which serves as a user interface, is connected to the controller 90. The touchscreen 96 inputs commands from the operator to the controller 90, for example. The touchscreen 96 also displays information about the cutting device 2 based on the commands from the controller 90.

[0068] In this embodiment, a touchscreen 96 having both input and output functions is shown, but an input device having an input function and an output device having an output function may be connected to the controller 90 separately. Examples of input devices include a keyboard and a mouse. Examples of output devices include a display device such as a liquid crystal display, a speaker that can transmit information by sound, and an indicator light that can transmit information by the color of light or the state of light emission (illumination, blinking, off, etc.).

[0069] Next, we will briefly explain the procedure for imaging the cutting blade 60 (processing unit 54), the processing points of the workpiece 11, etc., from mainly the second surface 24b side of the holding plate 24 while the workpiece 11 held by the table 20 is processed on the planned processing line 13. Figure 4 shows the state after processing of the workpiece 11 has started.

[0070] For example, before machining of the workpiece 11 begins, the table moving mechanism 10, the rotary drive source 28, and the machining unit moving mechanism 38 adjust the positional relationship between the table 20 and the machining unit 54 so that the cutting blade 60 is positioned above the extension of any planned machining line 13.

[0071] Next, the machining unit moving mechanism 38 adjusts the height of the machining unit 54 so that the height of the lower end of the cutting blade 60 is slightly lower than the height of the lower surface of the workpiece 11 (in this embodiment, the first surface 11a). Then, the rotational drive source of the machining unit 54 rotates the cutting blade 60 by rotating the spindle 58.

[0072] Furthermore, for example, in conjunction with the series of operations described above, the Y-axis movement mechanism 66 adjusts the position of the reflective part 86 (reflective member 86c) to be directly below the cutting blade 60 (processing unit 54). In addition, the lower camera movement mechanism 82 adjusts the position of the lower camera 84 along the X-axis so that the focus of the lower camera 84 aligns with the lower end of the cutting blade 60, the processing point of the workpiece 11, etc., which are the objects being imaged. This adjustment of the position of the lower camera 84 (focus adjustment) can be performed using, for example, the principle of autofocus such as the contrast method or the image plane phase difference method.

[0073] Furthermore, since the reflective portion 86 (reflective member 86c) does not move during this focus adjustment, the position of the reflective member 86c relative to the holding plate 24 and the object being imaged remains substantially unchanged. In this way, the lower camera movement mechanism 82 can change the distance between the lower camera 84 and the reflective member 86c without changing the position of the reflective member 86c relative to the holding plate 24 and the object being imaged.

[0074] Furthermore, as long as the position of the reflective member 86c relative to the holding plate 24 and the object being imaged remains substantially unchanged, the distance between the holding plate 24 and the object being imaged and the reflective member 86c also remains substantially unchanged. In other words, the lower camera movement mechanism 82 can change the distance between the lower camera 84 and the reflective member 86c without changing the distance between the holding plate 24 and the object being imaged and the reflective member 86c.

[0075] Subsequently, the table movement mechanism 10 moves the table 20 along the X-axis to bring it closer to the cutting blade 60. When the cutting blade 60 comes into contact with the workpiece 11 held by the table 20, machining of the workpiece 11 begins.

[0076] As shown in Figure 4, when machining of the workpiece 11 begins, machining marks, such as kerf marks, are formed on the target machining line 13 of the workpiece 11. In this embodiment, since the height of the lower end of the cutting blade 60 is lower than the height of the lower surface of the workpiece 11, machining marks are formed on the workpiece 11 that penetrate the workpiece 11 from its upper surface to its lower surface.

[0077] Furthermore, since the workpiece 11 is machined by moving the table 20 along the X-axis, the position of the reflective portion 86 (reflective member 86c) relative to the cutting blade 60 (machining unit 54) does not substantially change during the machining of the workpiece 11. Therefore, when the workpiece 11 held by the table 20 is being machined by the cutting blade 60, the reflective portion 86 (reflective member 86c) is always directly below the cutting blade 60.

[0078] In other words, when the workpiece 11 held by the table 20 is being processed by the cutting blade 60, the reflective member 86c of the reflective section 86 is positioned along a straight line perpendicular to the first surface 24a of the holding plate 24, passing through the cutting blade 60. The reflective member 86c then reflects light from the area on the first surface 24a side of the holding plate 24 (the object being imaged) toward the lower camera 84.

[0079] As a result, the lower camera 84 of the second imaging unit 64 can acquire an image of the area on the first surface 24a side of the holding plate 24 (the object being imaged) as seen from a position perpendicular to the first surface 24a of the holding plate 24 and along a straight line passing through the cutting blade 60, precisely at the moment when the workpiece 11 held by the table 20 is being processed by the cutting blade 60.

[0080] In contrast, the first imaging unit 62 can image the workpiece 11 held by the table 20 from above at the same timing as the second imaging unit 64, or at a different timing than the second imaging unit 64. The first imaging unit 62 is fixed to the machining unit 54, for example, via a Z-axis moving plate 48, and images an area away from the cutting blade 60 (an area in front of the cutting blade 60) in the direction along the X axis.

[0081] Figure 4 also shows the optical path 21a of light incident on the first imaging unit (upper camera) 62, and the optical paths 21b and 21c of light incident on the lower camera 84. The images acquired by the first imaging unit 62 and the second imaging unit 64 are stored, for example, in a storage device 94 provided in the controller 90 and used later.

[0082] By the way, as described in the procedure above, in order to make the cutting blade 60 cut into the planned machining line 13 of the workpiece 11, it is necessary to position the cutting blade 60 to match the target planned machining line 13. To do this, first the orientation (longitudinal direction) of the target planned machining line 13 must be aligned with the X-axis. This type of adjustment is called alignment (especially θ alignment).

[0083] In the alignment process, which aligns the orientation of the target machining line 13 with the X-axis, for example, based on a command from the controller 90, the workpiece 11 is imaged at two separate locations along the X-axis. The controller 90 then extracts characteristic patterns, such as key patterns, from the two obtained images within the device 15.

[0084] Since the distance from the key pattern to the planned machining line 13 is fixed, the controller 90 can calculate the orientation (and position) of the planned machining line 13 based on the position of the extracted pattern. The controller 90 then rotates the table 20 so that the calculated orientation of the planned machining line 13 aligns with the X-axis.

[0085] The cutting apparatus 2 of this embodiment includes a first imaging unit 62 positioned above the table 20 and a second imaging unit 64 positioned below the table 20. Therefore, the controller 90 can perform alignment using either the first imaging unit 62 or the second imaging unit 64.

[0086] For example, if the workpiece 11 is held on the table 20 with the first surface 11a on which the device 15 is located facing upwards, the controller 90 performs alignment using the first imaging unit 62. Also, for example, if the workpiece 11 is held on the table 20 with the first surface 11a on which the device 15 is located facing downwards, the controller 90 performs alignment using the second imaging unit 64.

[0087] The second imaging unit 64 has a reflective section 86 which is positioned directly below the cutting blade 60, that is, on a straight line parallel to the Z-axis passing through the cutting blade 60 (processing unit 54) (coaxial). Therefore, when alignment is performed using the second imaging unit 64, the orientation of the planned processing line 13 will not shift relative to the cutting blade 60 during processing by the cutting blade 60.

[0088] However, the first imaging unit 62 is positioned to the side of the cutting blade 60, that is, at least in the direction along the X axis from the cutting blade 60 (processing unit 54) (non-coaxial). Therefore, when alignment is performed using the first imaging unit 62, the orientation of the planned processing line 13 may be slightly shifted relative to the cutting blade 60 during processing by the cutting blade 60.

[0089] This phenomenon is caused by a slight error (yawing) in the table movement mechanism 10, which moves the machining unit 54 and the first imaging unit 62 linearly and relatively between them and the table 20, which causes the table 20 to rotate. As the positional relationship between the machining unit 54 and the first imaging unit 62 and the table 20 changes from the relationship during alignment to the relationship during machining by the cutting blade 60, the orientation of the planned machining line 13 shifts from the orientation assumed during alignment by the amount of the error in the table movement mechanism 10.

[0090] Therefore, in this embodiment, before the alignment described above, the controller 90 acquires information to correct the orientation deviation caused by this error. Specifically, the controller 90 acquires angular information representing the orientation of the table 20 around the rotation axis when the same target area is imaged by the first imaging unit 62, using the orientation of the table 20 around the rotation axis when the target area is imaged by the second imaging unit 64 as a reference.

[0091] Figure 5 is a flowchart showing an information acquisition method for obtaining angle information and a processing method including this information acquisition method. As shown in Figure 5, in the information acquisition method and processing method according to this embodiment, first, the controller 90 uses the second imaging unit 64 to image the target area including the groove 24c of the holding plate 24 of the table 20 from below, thereby acquiring an image (first image) showing the groove 24c (first image acquisition step ST11).

[0092] Figure 6 is a cross-sectional view showing how the second imaging unit 64 images the target area including the groove 24c of the holding plate 24 from below. As shown in Figure 6, the controller 90 uses the table moving mechanism 10 and the Y-axis moving mechanism 66 to adjust the positional relationship between the table 20 and the lower imaging unit 80 so that the reflective portion 86 of the second imaging unit 64 is positioned directly below the groove 24c of the holding plate 24. Preferably, the controller 90 positions the reflective member 86c of the reflective portion 86 directly below the intersection of the cross-shaped groove 24c.

[0093] Furthermore, the controller 90 adjusts the position of the lower camera 84 using the lower camera movement mechanism 82 so that the focus of the lower imaging unit 80 aligns with the first surface 24a of the holding plate 24. The controller 90 then uses the lower camera 84 to image the first surface 24a of the holding plate 24. The obtained image is stored, for example, in the storage device 94 provided by the controller 90. Note that the above-described procedure regarding the arrangement and adjustment of each part may be modified or omitted within a range that allows the second imaging unit 64 to appropriately image the target area.

[0094] Figure 7 shows an example of an image (first image) 23a obtained by the second imaging unit 64. For the sake of explanation, Figure 7 shows image 23a, which is obtained by converting the image obtained by the second imaging unit 64, that is, an image of the groove 24c viewed from below (orientation), to an image of the groove 24c viewed from above (orientation).

[0095] As shown in Figure 7, in this embodiment, the long left and right portions of the groove 24c shown in image 23a are aligned with the reference line 23b (typically the X-axis). In other words, the center line of the long left and right portions of the groove 24c in image 23a is roughly parallel to the reference line 23b. However, the orientation of the table 20 around its rotation axis does not necessarily have to be adjusted in this way when the groove 24c is imaged by the second imaging unit 64.

[0096] Next, the controller 90 acquires an image (second image) showing the groove 24c of the holding plate 24 of the table 20 by imaging the target area including the groove 24c of the holding plate 24 of the table 20 from above using the first imaging unit 62 (second image acquisition step ST12). Figure 8 is a cross-sectional view showing how the target area including the groove 24c of the holding plate 24 is imaged from above by the first imaging unit 62.

[0097] As shown in Figure 8, the controller 90 uses the table moving mechanism 10 and the processing unit moving mechanism 38 to adjust the positional relationship between the table 20 and the first imaging unit 62 so that the first imaging unit 62 is positioned directly above the groove 24c of the holding plate 24. Preferably, the controller 90 positions the first imaging unit 62 directly above the intersection of the cross-shaped groove 24c.

[0098] Furthermore, the controller 90 adjusts the focus of the first imaging unit 62 to the first surface 24a of the holding plate 24. Then, the controller 90 uses the first imaging unit 62 to image the first surface 24a of the holding plate 24. The obtained image is stored, for example, in the storage device 94 provided by the controller 90. Note that the above-described procedure regarding the arrangement and adjustment of each part may be modified or omitted within a range that allows the first imaging unit 62 to appropriately image the target area.

[0099] However, the rotation mechanism 33 does not rotate the table 20 between the time the target area is imaged using the second imaging unit 64 and the time the target area is imaged using the first imaging unit 62. In other words, the table moving mechanism 10 moves the table 20 along a direction parallel to the X-axis without the rotation mechanism 33 rotating the table 20, so that the first imaging unit 62 and the second imaging unit 64 image the same target area on the first surface 24a side of the holding plate 24 and acquire two images.

[0100] Figure 9 shows an example of an image (second image) 23c obtained by the first imaging unit 62. As shown in Figure 9, in this image 23c, the center line of the long left and right portion of the groove 24c is tilted at an angle θ with respect to the reference line 23d. This indicates that when transitioning from a state for imaging the target area using the second imaging unit 64 to a state for imaging the target area using the first imaging unit 62, the table 20 rotates at an angle θ around the rotation axis.

[0101] Note that in Figure 9, for the sake of explanation, the angle that the center line of the groove 24c makes with the reference line 23d, that is, the amount of rotation of the table 20 when transitioning from the state for imaging using the second imaging unit 64 to the state for imaging using the first imaging unit 62, is emphasized. However, the actual magnitude of θ is at most about 0.0001 to 0.0005°.

[0102] Once the image 23a obtained by the second imaging unit 64 and the image 23c obtained by the first imaging unit 62 are obtained, the controller 90 performs appropriate processing on them to calculate θ as angle information (angle information acquisition step ST13). This θ is angle information that represents the orientation of the table 20 around the rotation axis when the target area is imaged by the first imaging unit 62, with the orientation of the table 20 around the rotation axis when the target area is imaged by the second imaging unit 64 as the reference. The acquired angle information is stored, for example, in the storage device 94 of the controller 90.

[0103] When alignment is performed using the first imaging unit 62, the orientation of the table 20 can be further adjusted using this angle information, thereby substantially reducing the deviation of the planned processing line 13 caused by errors in the table movement mechanism 10 to zero. In this embodiment, image 23a is acquired by the second imaging unit 64 before image 23c is acquired by the first imaging unit 62, but image 23c may be acquired by the first imaging unit 62 before image 23a is acquired by the second imaging unit 64.

[0104] In the machining method according to this embodiment, the workpiece 11 is machined after the angle information is acquired. Specifically, the workpiece 11 is loaded onto the table 20 and held therein. Then, alignment is performed using the first imaging unit 62 or the second imaging unit 64. For example, if the workpiece 11 is held by the table 20 and the surface with a pattern suitable for alignment (typically the first surface 11a) is facing upwards, alignment is performed using the first imaging unit 62.

[0105] Furthermore, for example, if the workpiece 11 is held by the table 20 and the surface with a pattern suitable for alignment (typically the first surface 11a) is facing downwards, alignment is performed using the second imaging unit 64. The controller 90, for example, determines whether or not the first imaging unit 62 is used when performing alignment (determination step ST14), and performs processing according to the result of that determination.

[0106] For example, if the first imaging unit 62 is used for alignment (YES in the determination step ST14), the controller 90 performs a normal alignment and then rotates the table 20 around the rotation axis by the amount θ indicated by the angle information described above (correction alignment step ST15).

[0107] On the other hand, if the second imaging unit 64 is used for alignment and the first imaging unit 62 is not used (determination step ST14 is NO), the controller 90 performs normal alignment without using the angle information described above (normal alignment step ST16). Subsequently, the controller 90 processes the workpiece 11 by inserting the rotating cutting blade 60 into the planned machining line 13 of the workpiece 11 (machining step ST17).

[0108] As described above, in the cutting apparatus (processing apparatus) 2, information acquisition method and processing method according to this embodiment, an image 23c is acquired by a first imaging unit 62, which is partially positioned away from the processing unit 54 in a direction along the X-axis parallel to the first surface 24a of the table (holding table) 20 (first direction), and an image 23a is acquired by a second imaging unit 64, which is partially positioned along a straight line passing through the processing unit 54 and parallel to the Z-axis perpendicular to the first surface 24a of the table 20 (second direction). From these, angle information (θ) representing the orientation of the table 20 around the rotation axis when the target area is imaged by the first imaging unit 62 is acquired, based on the orientation of the table 20 around the rotation axis when the target area is imaged by the second imaging unit 64.

[0109] Therefore, when performing alignment using the first imaging unit 62, the orientation of the table 20 can be adjusted using the acquired angle information to bring the orientation of the table 20 closer to the orientation of the table 20 when performing alignment using the second imaging unit 64. Thus, according to the cutting apparatus 2, information acquisition method, and processing method of this embodiment, even when performing alignment using the first imaging unit 62 located to the side of the processing unit 54, a sufficiently high level of processing accuracy can be achieved.

[0110] Furthermore, the present invention can be implemented with various modifications without being limited by the embodiments described above. For example, in the embodiments described above, the intersection of the cross-shaped groove 24c is imaged by the first imaging unit 62 and the second imaging unit 64 respectively to obtain θ as angle information, but the method for obtaining θ is not limited to this.

[0111] For example, the orientation of the groove 24c can be calculated by imaging two separate locations of the groove 24c with the first imaging unit 62, and the orientation of the groove 24c can be calculated by imaging the same two locations with the second imaging unit 64. The difference in orientation (angle) between these two grooves can then be used as angle information (θ). In this case, since information from two separate locations is used, it is possible to calculate θ with high accuracy even when θ is extremely small.

[0112] Furthermore, in the above-described embodiment, a cutting device (processing device) 2 incorporating a first imaging unit 62 and a second imaging unit 64 capable of acquiring angle information (θ) was illustrated, but other processing devices may be configured similarly. For example, the first imaging unit and the second imaging unit can be incorporated into a laser processing device that includes a processing unit (laser irradiation unit) that includes a light concentrator for focusing a laser beam onto a workpiece, in order to acquire angle information (θ).

[0113] Furthermore, in the embodiment described above, angular information (θ) indicating the displacement of the table 20 around its axis of rotation is obtained. However, using a similar principle, positional information indicating the displacement of the table 20 in the direction along the Y-axis, the displacement of the table 20 in the direction along the Z-axis, etc., may also be obtained.

[0114] Furthermore, the structures, methods, etc., of the embodiments and their respective modifications described above may be modified as appropriate, as long as they do not deviate from the scope of the present invention. [Explanation of symbols]

[0115] 2: Cutting equipment (processing equipment) 4: Base 6: Cassette Table 8: Cassette 10: Table movement mechanism (machining feed mechanism, first movement mechanism) 12: X-axis guide rail 14:X-axis moving part 14a: Bottom plate 14b: Side plate 14c: Tabletop 14d: Space 14e: Nut part 14f: Opening 16: Screw shaft 18: Rotary drive source 20: Tables (holding tables, chuck tables) 22:Frame body 22a: Space 24: Holding plate 24a: 1st surface (top surface) 24b: 2nd side (bottom side) 24c: Groove 26: Pulley 28: Rotary drive source 30: Pulley 32: Belt 33: Rotating mechanism 36:Support structure 38: Machining unit movement mechanism (indexing feed mechanism, cutting feed mechanism) 54: Machining unit (cutting unit) 58: Spindle 60: Cutting blade (machining tool) 61: Nozzle 62: First imaging unit (upper imaging unit, upper camera) 64: Second Imaging Department 66:Y-axis movement mechanism (second movement mechanism) 68: Y-axis guide rail 70: Y-axis moving plate 72: Nut part 74: Screw shaft 76: Rotary drive source 78 :Support 80: Lower imaging unit 82: Lower camera movement mechanism (third movement mechanism) 82a: Moving part 84: Lower camera 86:Reflector 86a: Reflector housing 86b: Opening 86c: Reflective material 88: Washing Unit 90: Controller (control unit) 92: Processing unit 94 :Storage device 96: Touchscreen (input / output device, input device, output device) 11: Workpiece 11a: 1st side (front) 11b: 2nd side (back side) 13: Processing line (street) 15: Device 23a: Image 23b:Reference line 23c: Image 23d: Reference line ST11: First image acquisition step ST12: Second image acquisition step ST13: Angle information acquisition step ST14: Judgment Step ST15: Correction Alignment Step ST16: Standard alignment step ST17: Machining Step

Claims

1. A processing device for processing a workpiece, A holding table having a holding plate that transmits light in at least a portion thereof, and configured to hold the workpiece on the first surface side of the holding plate, A processing unit configured to process the workpiece held by the holding table, A moving mechanism configured to move the holding table and the processing unit relative to each other along a first direction parallel to the first surface, A rotation mechanism configured to allow the holding table to rotate around a rotation axis along a second direction perpendicular to the first surface, A first imaging unit is provided, which is positioned on the first surface side of the holding plate at a distance from the processing unit at least in the first direction, and is configured to be able to image the region of the first surface side of the holding plate. A second imaging unit is provided, on the second surface side of the holding plate opposite to the first surface, with a portion of it positioned along a straight line parallel to the second direction passing through the processing unit, and configured to capture images of the area on the first surface side of the holding plate. Control unit, including, The control unit acquires two images by having the first imaging unit and the second imaging unit image the same target area on the first surface side of the holding plate, by having the moving mechanism move the holding table along the first direction without the rotating mechanism rotating the holding table, and from the two images, it acquires angular information representing the orientation of the holding table around the rotation axis when the target area is imaged by the first imaging unit, with the orientation of the holding table around the rotation axis when the target area is imaged by the second imaging unit as the reference.

2. The first surface of the holding plate is provided with a groove for applying negative pressure to the workpiece when holding the workpiece. The processing apparatus according to claim 1, wherein the first imaging unit and the second imaging unit image the target region including the groove.

3. The processing apparatus according to claim 1 or 2, wherein the control unit adjusts the orientation of the holding table around the rotation axis using the angle information when the processing unit processes the workpiece using an image obtained by imaging the workpiece held by the holding table with the first imaging unit.

4. The processing unit has a spindle on which a processing tool that comes into contact with the workpiece is mounted, or a light concentrator that focuses a laser beam onto the workpiece. The processing apparatus according to claim 1 or claim 2, wherein a portion of the second imaging unit is arranged along the straight line passing through the processing tool or the light condenser.

5. An information acquisition method for acquiring information for adjusting the orientation of a holding table provided by a processing device, The processing apparatus is A holding table having a holding plate that transmits light in at least a portion thereof, and configured to hold the workpiece on the first surface side of the holding plate, A processing unit configured to process the workpiece held by the holding table, A moving mechanism configured to move the holding table and the processing unit relative to each other along a first direction parallel to the first surface, A rotation mechanism configured to allow the holding table to rotate around a rotation axis along a second direction perpendicular to the first surface, A first imaging unit is provided, which is positioned on the first surface side of the holding plate at a distance from the processing unit at least in the first direction, and is configured to be able to image the region of the first surface side of the holding plate. The device comprises a second imaging unit, which is positioned on the second surface side of the holding plate opposite to the first surface, along a straight line parallel to the second direction passing through the processing unit, and configured to capture images of the area on the first surface side of the holding plate. Image acquisition step: The rotation mechanism does not rotate the holding table, but the movement mechanism moves the holding table along the first direction, thereby capturing images of the same target area on the first surface side of the holding plate with the first imaging unit and the second imaging unit to acquire two images. An information acquisition method comprising: an angle information acquisition step of acquiring angle information from the two images, using as a reference the orientation of the holding table around the rotation axis when the target area is imaged by the second imaging unit, the orientation of the holding table around the rotation axis when the target area is imaged by the first imaging unit.

6. The first surface of the holding plate is provided with a groove for applying negative pressure to the workpiece when holding the workpiece. The information acquisition method according to claim 5, wherein in the image acquisition step, the first imaging unit and the second imaging unit image the target region including the groove.

7. A processing method for processing a workpiece using the information acquisition method described in claim 5 or claim 6, The process further includes, after the angle information acquisition step, a processing step in which the workpiece held by the holding table is imaged by the first imaging unit and the workpiece is processed by the processing unit using the image obtained, A machining method in which, in the machining step, the workpiece is machined with the orientation of the holding table around the rotation axis adjusted using the angle information.

Images