Processing apparatus and processing method

Abstract

The present invention provides a processing device that can appropriately image the processing unit and the processing points of the workpiece while processing the workpiece. [Solution] The processing apparatus includes a holding table having a holding plate that transmits light in at least a portion thereof, 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; and an imaging mechanism configured to image the region on the first surface side of the holding plate from the second surface side opposite to the first surface of the holding plate. The imaging mechanism is configured to acquire an image of the region on the first surface side of the holding plate as viewed from a position perpendicular to the first surface and along a straight line passing through the processing unit, when the workpiece held by the holding table is being processed by the processing unit.

Description

Technical Field

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

Background Art

[0002] In electronic devices typified 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 dividing the surface side of a wafer made of silicon or the like into a plurality of small regions by straight processing planned lines (streets), forming devices in each small region, and then dividing the wafer along the processing planned lines.

[0003] When dividing a wafer as described above into a plurality of device chips, for example, a cutting device 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 cutting into the wafer in 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 above-described cutting device usually includes an imaging unit (camera) adjacent to the processing unit, and uses this imaging unit to image the processing marks formed on the wafer. Based on the position and state of the processing marks shown in the obtained image, it is possible to determine whether the wafer has been appropriately processed.

[0006] Incidentally, when processing a plate-shaped workpiece such as a wafer with a cutting blade, only a portion of the lower end of the cutting blade penetrates the workpiece. Therefore, the processing point where the cutting blade contacts the workpiece cannot be visually observed from a position adjacent to the processing unit, making it difficult for an imaging unit positioned at this location to capture images of the processing point while it is in progress. Furthermore, since liquids such as water are supplied near the processing point, the processing marks in the image may be distorted due to the influence of this liquid.

[0007] To address these issues, until now, pre-formed machining marks located sufficiently far from the machining point where the cutting blade makes contact have been imaged. However, if it were possible to appropriately image the machining unit and the machining point of the workpiece at the very moment the workpiece is being processed, it would be extremely useful as it would allow for real-time confirmation of defects occurring during machining.

[0008] Therefore, the object of the present invention is to provide a processing apparatus and a processing method that can appropriately image the processing unit and the processing points of the workpiece while processing the workpiece. [Means for solving the problem]

[0009] According to one aspect of the present invention, a processing apparatus for processing a workpiece is provided, comprising: a holding table having a holding plate that at least a portion of which transmits light, 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; and an imaging mechanism configured to image the region of the holding plate on the first surface side from the second surface side of the holding plate opposite to the first surface, wherein the imaging mechanism is configured to acquire an image of the region of the holding plate on the first surface side when the workpiece held by the holding table is being processed by the processing unit, viewed from a position perpendicular to the first surface and along a straight line passing through the processing unit.

[0010] In one aspect of the present invention, it is preferable that the imaging mechanism includes a camera, a reflective member positioned perpendicular to the first surface and along the straight line passing through the processing unit when the workpiece held by the holding table is being processed by the processing unit, and reflecting light from the region of the holding plate on the first surface side toward the camera, and a first moving mechanism configured to change the distance between the camera and the reflective member without changing the distance between the holding plate and the reflective member by moving the camera and the reflective member relative to each other.

[0011] Furthermore, in one aspect of the present invention, it is preferable that the invention further includes a second moving mechanism configured to move the holding table, wherein the first moving mechanism is configured to change the distance between the camera and the reflective member without changing the position of the reflective member relative to the holding plate.

[0012] Furthermore, in one aspect of the present invention, the processing unit preferably has 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 the reflecting member is preferably positioned along the straight line passing through the processing tool or the light concentrator when the workpiece held by the holding table is being processed by the processing unit.

[0013] Furthermore, in one aspect of the present invention, the reflective member is preferably a prism or a mirror.

[0014] Furthermore, in one aspect of the present invention, it is preferable that the invention further includes a control unit for controlling the operation of the processing unit, wherein the control unit determines whether or not to interrupt the processing of the workpiece by the processing unit based on the image acquired by the imaging mechanism when the workpiece is being processed by the processing unit.

[0015] According to another aspect of the present invention, a processing method for processing a workpiece is provided, comprising: a holding step of holding the workpiece on the first surface side of a holding table having a holding plate that at least a portion of which transmits light; a processing step of processing the workpiece held by the holding table with a processing unit; and an imaging step of imaging a region including the processing point of the workpiece being processed with an imaging mechanism from the second surface side of the holding plate opposite to the first surface, while the workpiece held by the holding table is being processed by the processing unit, wherein the imaging step acquires an image of the region including the processing point as viewed from a position perpendicular to the first surface and along a straight line passing through the processing unit.

[0016] In another aspect of the present invention, the invention may further include an interruption determination step, in which, while the workpiece is being processed by the processing unit, the imaging mechanism determines whether or not to interrupt the processing of the workpiece by the processing unit based on the image it has acquired. [Effects of the Invention]

[0017] According to one aspect of the present invention, a processing apparatus and another aspect of the present invention, when a workpiece held on a holding table (the first surface side of the holding plate) is being processed by a processing unit, an imaging mechanism is used that can image the region on the first surface side of the holding plate (the region including the processing point of the workpiece) from the second surface side opposite to the first surface of the holding plate. By obtaining an image of the region on the first surface side of the holding plate, that is, the region including the processing point of the workpiece, as viewed from a position perpendicular to the first surface of the holding plate and along a straight line passing through the processing unit, the processing unit and the processing point of the workpiece can be appropriately imaged while the workpiece is being processed. [Brief explanation of the drawing]

[0018] [Figure 1] Figure 1 is a schematic perspective view showing the structure of a cutting device according to an embodiment. [Figure 2] Figure 2 is a schematic perspective view showing the structure of the workpiece according to the embodiment. [Figure 3]FIG. 3 is a perspective view schematically showing a part of the cutting device. [Figure 4] FIG. 4 is a cross-sectional view schematically showing a part of the cutting device, and shows a state before machining of the workpiece. [Figure 5] FIG. 5 is a cross-sectional view schematically showing a part of the cutting device, and shows a state after machining of the workpiece has started. [Figure 6] FIG. 6 is a cross-sectional view schematically showing a part of the cutting device, and shows a state in which machining is being performed near the center of the workpiece. [Figure 7] FIG. 7 is a cross-sectional view schematically showing a part of the cutting device, and shows a state before machining of the workpiece ends. [Figure 8] FIG. 8 is a cross-sectional view schematically showing a part of the cutting device, and shows a state after machining of the workpiece has ended. [Figure 9] FIG. 9 is a flowchart showing the processing method according to the embodiment.

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 device (processing device) 2 according to the present embodiment. In FIG. 1, some elements are represented by functional blocks. Also, 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 device 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 the 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 side of the workpiece 11. This member is configured to transmit, for example, 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.

[0024] Similarly, the type, quantity, shape, structure, size, arrangement, etc., of the device 15 are not limited to the above-described embodiments. The workpiece 11 does not need to have the device 15 formed on it. In addition, the support (or protective) member may be attached to the second surface 11b side of the workpiece 11. Furthermore, the support (or protective) member does not need to be attached to the workpiece 11.

[0025] 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.

[0026] As shown in Figures 3 and 4, a ball screw type table moving mechanism (machining feed mechanism, second 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.

[0027] 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). The lower end portion of a flat side plate 14b, which is rectangular when viewed from the direction along the Y-axis, is connected to one end portion of the bottom plate 14a in the direction along the Y-axis (third direction). The upper end portion of the side plate 14b is connected to one end portion of a flat top plate 14c, which is rectangular when viewed from the direction along the Z-axis, similar to the shape of the bottom plate 14a.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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 entirely transparent is shown as an example, 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. Also, the first surface 24a and the second surface 24b of the holding plate 24 are approximately perpendicular to the rotation axis of the table 20, that is, to the Z-axis.

[0035] The frame 22 is provided with a flow path (not shown) for transmitting negative pressure used to suck the workpiece 11. An opening (not shown) corresponding to one end of this flow path is formed on the upper end surface of the frame 22. A suction source (not shown) for generating negative pressure is connected to the other end of the flow path. As the suction source, for example, a vacuum pump combining an air supply source and an ejector can be used.

[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. In addition, 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 mechanism 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, for example, with the first surface 11a, to which a support (or protective) member is attached, facing downwards (with the second surface 11b facing upwards).

[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] An upper imaging unit (upper camera) 62 is fixed to the lower part of the Z-axis moving plate 48, configured to capture images of the workpiece 11, etc., supported by the table 20, from above. The processing unit 54 and the upper imaging unit 62 move along the Y-axis and Z-axis by the processing unit moving mechanism 38.

[0050] The upper imaging unit 62 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 visible light and / or infrared light. Furthermore, the upper 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 upper imaging unit 62 are not limited to this embodiment.

[0051] As shown in Figures 3 and 4, a Y-axis movement mechanism (third movement mechanism) 66, which constitutes an imaging mechanism 64 for imaging the workpiece 11 etc. from below, is located 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 (first 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 directly below the holding plate 24 by the table moving mechanism 10 and the Y-axis moving mechanism 66, so that the area on the first surface 24a side of the holding plate 24 (workpiece 11 etc. placed on the first surface 24a side of the holding plate 24) can be imaged by the lower camera 84. In other words, the lower imaging unit 80 can image the workpiece 11 etc. placed on the first surface 24a side of the holding plate 24 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. Controllers (control units) 90 are 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 upper imaging unit 62, the Y-axis moving mechanism 66, the lower imaging unit 80, 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, referring to Figures 4 to 8, we will explain the procedure for imaging the cutting blade 60 (machining unit 54), the machining point of the workpiece 11, etc., from the second surface 24b side of the holding plate 24 while the workpiece 11 held by the table 20 is being machined on the planned machining line 13. Figure 4 shows the state of the workpiece 11 before machining begins.

[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, as shown in Figure 4, 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 contacts the workpiece 11 held by the table 20, machining of the workpiece 11 begins. Figure 5 is a schematic cross-sectional view showing part of the structure inside the opening 4b of the cutting device 2, and shows the state after machining of the workpiece 11 has begun.

[0076] As shown in Figure 5, 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] In this embodiment, the workpiece 11 is machined by moving the table 20 along the X-axis, so 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 imaging mechanism 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 Figure 5, etc., the optical path of light incident on the lower camera 84 is represented as a first optical path 21a, which is reflected by the workpiece 11 on the first surface 24a side of the holding plate 24, passes through the opening 86b, and is incident on the reflecting member 86c, and a second optical path 21b, which is reflected by the reflecting member 86c and is incident on the lower camera 84. The image acquired by the lower camera 84 is stored, for example, in a storage device 94 provided in the controller 90 and used for determining defects that occur during processing.

[0081] The imaging operation described above is performed while the table moving mechanism 10 moves the table 20 along the X-axis, that is, while the cutting blade 60 is machining the workpiece 11 on the target machining line 13. Furthermore, this imaging operation is repeated, for example, until the machining of the workpiece 11 on the target machining line 13 is completed. In other words, the imaging mechanism 64 continues to repeatedly image the area on the first surface 24a side of the holding plate 24 while the machining of the workpiece 11 continues.

[0082] Figure 6 is a schematic cross-sectional view showing a part of the structure inside the opening 4b of the cutting device 2, indicating that machining is being performed near the center of the workpiece 11. Figure 7 is a schematic cross-sectional view showing a part of the structure inside the opening 4b of the cutting device 2, indicating the state before the machining of the workpiece 11 is completed. Figure 8 is a schematic cross-sectional view showing a part of the structure inside the opening 4b of the cutting device 2, indicating the state after the machining of the workpiece 11 is completed.

[0083] As shown in Figures 5, 6, and 7, as long as light from the region on the first surface 24a side of the holding plate 24 can enter the reflective member 86c of the reflecting part 86, that is, as long as the reflective member 86c is positioned directly below the space 22a inside the frame 22, the imaging mechanism 64 can acquire an image of the region on the first surface 24a side of the holding plate 24 (the object to be imaged).

[0084] On the other hand, when the reflective member 86c is positioned in an area away from directly below the space 22a inside the frame 22, specifically, directly below the frame 22 or the top plate 14c, the imaging mechanism 64 cannot acquire an image of the area on the first surface 24a side of the holding plate 24 (the object to be imaged). In other words, in the state shown in Figures 4 and 8, the imaging mechanism 64 cannot acquire an image of the area on the first surface 24a side of the holding plate 24 (the object to be imaged).

[0085] However, since most of the workpiece 11 (excluding the outer edge) is positioned directly above the inner space 22a of the frame 22, there is no practical problem even if the imaging mechanism 64 cannot acquire an image immediately after the processing of the workpiece 11 begins or immediately before the processing of the workpiece 11 ends. Furthermore, if the diameter of the inner space 22a of the frame 22 is made larger than the diameter of the workpiece 11, the imaging mechanism 64 will be able to acquire an image immediately after the processing of the workpiece 11 begins or immediately before the processing of the workpiece 11 ends.

[0086] Next, with reference to Figure 9, an example of a machining method for processing the workpiece 11 using the cutting device 2 described above will be explained. Figure 9 is a flowchart of the machining method according to this embodiment. In this embodiment, the machining method is entirely carried out based on commands from the controller 90 of the cutting device 2, but a part of the machining method may be carried out by an operator (human).

[0087] As shown in Figure 9, in the processing method of this embodiment, first, the workpiece 11 is held by the table 20 (holding step ST11). For example, the transport mechanism places the workpiece 11 on the table 20 so that the first surface 11a side, to which the support (or protective) member is attached, faces downward. Then, the controller 90 opens a valve connected to the flow path of the table 20, and applies negative pressure from the suction source to the upper surface of the table 20. As a result, the workpiece 11 is held by the table 20.

[0088] After the workpiece 11 is held by the table 20, the workpiece 11 is machined (machining step). Specifically, the positional relationship between the workpiece 11 and the cutting blade 60 is adjusted according to the procedure described above, and then, with the cutting blade 60 rotating, the table 20 moves along the X axis. This starts the machining of the workpiece 11 on the target machining line 13 (machining start step ST12).

[0089] After the processing of the workpiece 11 has started, for example, an area including the processing point of the workpiece 11 is imaged (imaging step ST13). The position of the reflective section 86 and the focus of the lower camera 84 are adjusted in advance according to the procedure described above. The image obtained by imaging the target area is stored, for example, in the storage device 94 of the controller 90.

[0090] Once an image of the target area is acquired, the controller 90 determines whether or not to interrupt the machining of the workpiece 11 by the cutting blade 60 (machining unit 54) based on this image (interruption determination step ST14). The controller 90 performs various processes on the acquired image and determines to interrupt the machining of the workpiece 11, for example, if it finds a defect in the workpiece 11, such as a crack, in the image, or if it finds a defect in the cutting device 2, such as vibration of the cutting blade 60, based on multiple acquired images.

[0091] If no defects are found in the image and it is determined that machining should not be interrupted (NO in the interruption determination step ST14), the controller 90 determines whether the cutting blade 60 has reached the end of the range in which it should move relative to the table 20 (end determination step ST15). The end of this relative movement range is set, for example, so that the cutting blade 60 is outside the area directly above the table 20.

[0092] If the controller determines that the cutting blade 60 has not reached the end of the range it should move relative to (NO in the end determination step ST15), the controller 90 continues machining the workpiece 11. In this case, the controller 90 again images the area including the machining point of the workpiece 11 (imaging step ST13).

[0093] On the other hand, if the controller determines that the cutting blade 60 has reached the end of the range it should move relative to (YES in the end determination step ST15), the controller 90 terminates the machining of the workpiece 11 on the target machining line 13 (machining completion step ST16). In this case, for example, the controller 90 stops the movement of the table 20 along the X axis.

[0094] If a defect is detected in the image and it is determined that machining should be interrupted (YES in the interruption determination step ST14), the controller 90 will, for example, raise the cutting blade 60 using the machining unit moving mechanism 38 to retract the cutting blade 60 from the workpiece 11 and interrupt the machining of the workpiece 11 (interruption step ST17). In addition, along with or instead of retracting the cutting blade 60, the controller 90 may stop the movement of the table 20 along the X axis.

[0095] If the machining of the workpiece 11 by the cutting blade 60 is interrupted, the controller 90 notifies the operator of the cutting device 2 of the interruption by, for example, displaying a message on the touchscreen 96 indicating that machining has been interrupted (notification step ST18). Upon learning that machining has been interrupted, the operator of the cutting device 2 can take measures such as changing the machining conditions, adjusting the state of the cutting blade 60 (dressing), or adjusting the position of the cutting blade 60 (setup), and then resume machining.

[0096] Furthermore, when the controller 90 determines whether or not to interrupt the processing of the workpiece 11 based on the image, the specific type of defect may be identified. In such cases, the controller 90 should notify the controller that processing has been interrupted, along with information regarding the specific type of defect that caused the interruption.

[0097] As described above, according to the cutting apparatus (processing apparatus) 2 and processing method of this embodiment, when the workpiece 11 held on the table 20 (the first surface 24a side of the holding plate 24) is being processed by the processing unit 54, an imaging mechanism 64 is used to image the area on the first surface 24a side of the holding plate 24 (the area including the processing point of the workpiece 11) from the second surface 24b side opposite to the first surface 24a of the holding plate 24. This captures an image of the area on the first surface 24a side of the holding plate 24, that is, the area including the processing point of the workpiece 11, as viewed from a position perpendicular to the first surface 24a of the holding plate 24 and along a straight line passing through the processing unit 54. Therefore, the processing unit 54 and the processing point of the workpiece 11 can be appropriately imaged while the workpiece 11 is being processed.

[0098] In other words, in the cutting apparatus 2 and processing method according to this embodiment, the processing point that contacts the cutting blade 60 of the workpiece 11 is imaged from directly below, so that the area including the processing point can be imaged while the processing of the workpiece 11 is in progress. Furthermore, in the cutting apparatus 2 and processing method according to this embodiment, the lower surface of the workpiece 11, which is hardly affected by liquids such as water, is imaged, so the obtained image is not distorted by the influence of liquids.

[0099] The present invention is not limited by the embodiments described above and can be implemented with various modifications. For example, although the above embodiments illustrate a cutting device (processing device) 2 incorporating an imaging mechanism 64, an imaging mechanism similar to the imaging mechanism 64 may be incorporated into other processing devices.

[0100] For example, an imaging mechanism can be incorporated into a laser processing apparatus that includes a processing unit (laser irradiation unit) containing a light concentrator that focuses a laser beam onto a workpiece. In this case, the reflective member is positioned along a straight line passing through the light concentrator while the workpiece, held by a table (holding table), is being processed by the processing unit.

[0101] Furthermore, in the embodiment described above, the controller 90 determines whether or not to interrupt the processing of the workpiece 11 based on the acquired image, and interrupts the processing of the workpiece 11 according to the result of that determination. However, the processing conditions may be changed without interrupting the processing of the workpiece 11. In this case, instead of determining whether or not to interrupt the processing, the controller 90 determines whether or not to change the processing conditions (condition change determination step).

[0102] Then, if it determines that the processing conditions should be changed, the controller 90 changes the processing conditions (condition change step). Specifically, the controller 90 changes conditions such as the rotation speed of the cutting blade 60 and the speed at which the table 20 moves along the X axis, so as to alleviate the symptoms of the defect that has occurred. After that, the controller 90 notifies that the conditions have been changed (notification step).

[0103] 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]

[0104] 2: Cutting equipment (processing equipment) 4: Base 6: Cassette Table 8: Cassette 10: Table movement mechanism (machining feed mechanism, second 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) 26: Pulley 28: Rotary drive source 30: Pulley 32: Belt 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) 62: Upper imaging unit (upper camera) 64: Imaging mechanism 66:Y-axis movement mechanism (third 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 (first 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 ST11: Holding step ST12: Machining start step ST13: Imaging step ST14: Interruption Determination Step ST15: Termination determination step ST16: Machining completion step ST17: Interruption Step ST18: Hochi 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, The present invention includes an imaging mechanism configured to capture images of the region of the first surface of the holding plate from the second surface opposite to the first surface of the holding plate, The imaging mechanism is, A processing apparatus configured to acquire an image of the region of the holding plate on the first surface side, viewed from a position perpendicular to the first surface and along a straight line passing through the processing unit, while the workpiece held by the holding table is being processed by the processing unit.

2. The imaging mechanism is, Camera and, When the workpiece held by the holding table is being processed by the processing unit, a reflective member is positioned perpendicular to the first surface and along the straight line passing through the processing unit, and reflects light from the area on the first surface side of the holding plate toward the camera, The processing apparatus according to claim 1, comprising: a first moving mechanism configured to change the distance between the camera and the reflective member without changing the distance between the holding plate and the reflective member by moving the camera and the reflective member relative to each other.

3. The present invention further includes a second moving mechanism configured to move the holding table, The processing apparatus according to claim 2, wherein the first moving mechanism is configured to change the distance between the camera and the reflective member without changing the position of the reflective member with respect to the holding plate.

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 2 or 3, wherein the reflective member is positioned along the straight line passing through the processing tool or the light concentrator when the workpiece held by the holding table is being processed by the processing unit.

5. The processing apparatus according to claim 2 or 3, wherein the reflective member is a prism or a mirror.

6. The system further includes a control unit that controls the operation of the processing unit, The processing apparatus according to claim 2 or 3, wherein the control unit determines whether or not to interrupt the processing of the workpiece by the processing unit based on the image acquired by the imaging mechanism when the workpiece is being processed by the processing unit.

7. A processing method for processing a workpiece, A holding step of holding a workpiece on the first surface side of a holding plate of a holding table having a holding plate that transmits light in at least a portion thereof, A processing step in which the workpiece held by the holding table is processed by a processing unit, The process includes an imaging step in which, while the workpiece held by the holding table is being processed by the processing unit, an imaging mechanism images the region of the workpiece including the positively processed processing point from the second surface side of the holding plate opposite to the first surface, A processing method comprising the imaging step of acquiring an image of the region including the processing point as viewed from a position perpendicular to the first surface and along a straight line passing through the processing unit.

8. The processing method according to claim 7, further comprising: an interruption determination step of determining whether or not to interrupt the processing of the workpiece by the processing unit based on an image acquired by the imaging mechanism while the workpiece is being processed by the processing unit.

Images