processing device

Abstract

A processing device is provided, which takes an image of a surface of a workpiece held by a chuck table, which is opposite to the chuck table. The processing device has a chuck table which has a holding surface exposed upward and which holds a plate-shaped workpiece placed on the holding surface by suction, and a camera unit which takes an image of the workpiece held by the chuck table, wherein the chuck table includes a holding portion whose upper surface constitutes a part of the holding surface and which applies negative pressure to the workpiece placed on the holding surface, and a light-transmitting portion which transmits light, the light-transmitting portion including a first region which overlaps the workpiece held by the chuck table and constitutes another part of the holding surface, the light-transmitting portion having a first mirror surface which reflects light traveling from the first region into the light-transmitting portion, the camera unit being able to take an image of the workpiece by detecting light which is reflected by the workpiece held by the chuck table, travels in the light-transmitting portion, and is reflected by the first mirror surface.

Description

TECHNICAL FIELD

[0001] The present application relates to a processing apparatus that has a chuck table that attracts and holds a workpiece such as a semiconductor wafer, and processes the workpiece attracted and held by the chuck table. BACKGROUND

[0002] A device chip for an electronic device such as a mobile phone or a computer is formed by dividing a semiconductor wafer in which a plurality of devices are arranged on the front surface into individual devices. When the semiconductor wafer is divided, a processing apparatus such as a cutting apparatus having a ring-shaped cutting tool or a laser processing apparatus having a laser processing unit that irradiates a laser beam to a workpiece is used, for example. In these processing apparatuses, the workpiece is processed along a division predetermined line that is set between the devices formed on the front surface of the workpiece.

[0003] In these processing apparatuses, in order to process the workpiece along the division predetermined line, a camera unit that photographs the workpiece and detects the division predetermined line is provided. When the workpiece is processed by the processing apparatus, first, the workpiece is placed on a chuck table that attracts and holds the workpiece in a state in which the front surface faces upward, and the chuck table attracts and holds the workpiece. Then, the front surface of the workpiece is photographed by the camera unit, the pattern constituting the device and the key pattern formed between the devices are detected, and the position of the division predetermined line is determined based on these positions.

[0004] However, depending on the type of the workpiece and the content of the processing, it is sometimes necessary to perform the processing in a state in which the front surface of the workpiece faces downward. In this case, if a camera unit that can detect light of a wavelength that transmits through the workpiece is used, the front surface side of the workpiece that is not exposed can be photographed through the workpiece. For example, in the case where the workpiece is a silicon wafer, this camera unit can use an infrared camera.

[0005] However, sometimes a metal film or a resin film that does not transmit light of a wavelength that transmits through the workpiece is provided on the back surface side of the workpiece. In this case, even if a camera unit that can detect light of a wavelength that transmits through the workpiece is used, the front surface side of the workpiece cannot be photographed through the metal film or the resin film. Therefore, a method in which the metal film or the resin film is removed at the outer periphery of the workpiece, the front surface side is photographed through the workpiece at a position exposed on the back surface of the workpiece, and the division predetermined line is detected has been proposed (see Patent Document 1).

[0006] Patent Document 1: Japanese Patent Application Publication No. 2015-159241

[0007] In order to observe the front surface side of a workpiece provided with a metal film or the like on the back surface side using a camera unit, it is necessary to remove the metal film or the like from the outer periphery of the workpiece by a sufficient width. Therefore, a dedicated edge trimming device having a cutting tool with a large width (thickness) is required to process the workpiece while rotating a chuck table that holds the workpiece along the outer periphery. However, the processing load of the edge trimming device is large, and the cost of the thick cutting tool is also high, and thus there is a problem in this method as well. SUMMARY

[0008] The present application has been made in view of the above problems, and has an object to provide a processing device capable of easily photographing the surface of a workpiece held by a chuck table, which is opposite to the chuck table.

[0009] According to one embodiment of the present application, there is provided a processing device including a chuck table having a holding surface exposed upward and attracting and holding a plate-shaped workpiece placed on the holding surface, a camera unit provided above the chuck table and photographing the workpiece held by the chuck table, and a processing unit processing the workpiece based on the photographing result of the camera unit, characterized in that the chuck table includes a holding portion whose upper surface constitutes a part of the holding surface and applies negative pressure to the workpiece placed on the holding surface, and a light-transmitting portion through which light passes, the light-transmitting portion including a first region overlapping the workpiece held by the chuck table and constituting another part of the holding surface, the light-transmitting portion having a first mirror surface reflecting light traveling from the first region into the light-transmitting portion, the camera unit detecting the light traveling from the first region into the light-transmitting portion and reflected by the first mirror surface by reflecting a second region of the workpiece held by the chuck table opposite to the first region, and being capable of photographing the second region of the workpiece.

[0010] Preferably, the processing device further includes an external mirror provided outside the chuck table in a radial direction, the light-transmitting portion has an exposed surface exposed to a side surface of the chuck table, the camera unit is positioned above the external mirror when detecting the light, and the external mirror reflects the light traveling from the exposed surface of the light-transmitting portion toward the camera unit. Alternatively, preferably, the light-transmitting portion further includes a third region not overlapping the workpiece held by the chuck table and constituting still another part of the holding surface, the camera unit is positioned above the third region when detecting the light, and the light-transmitting portion further has a second mirror surface reflecting the light reflected by the first mirror surface toward the camera unit through the third region.

[0011] Further, it is preferable that the light-transmissive portion has a light-transmissive member that partitions the space inside the light-transmissive portion from the outside. Alternatively, it is preferable that the light-transmissive portion is filled with a light-transmissive member.

[0012] In the processing apparatus of one embodiment of the present application, the chuck table that holds the object to be processed by suction includes, in addition to the holding portion that applies negative pressure to the object to be processed, a light-transmissive portion through which light passes. Further, the holding surface of the upper surface of the chuck table includes a first region of the light-transmissive portion. The light-transmissive portion has a first mirror surface that reflects light that travels from the first region into the light-transmissive portion. The camera unit can detect light reflected by a second region of the object to be processed that is opposite the first region of the light-transmissive portion, through the light-transmissive portion. Thus, the camera unit can capture an image of the second region of the object to be processed.

[0013] Thus, according to one embodiment of the present application, there is provided a processing apparatus that can easily capture an image of a surface of an object to be processed held by a chuck table, which is opposite the chuck table. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 (A) of FIG. 1 is a schematic cross-sectional view of a wafer. Figure 1 (B) of FIG. 1 is a schematic cross-sectional view of a wafer.

[0015] Figure 2 (A) of FIG. 2 is a schematic cross-sectional view of a package substrate. Figure 2 (B) of FIG. 2 is a schematic cross-sectional view of a package substrate.

[0016] Figure 3 FIG. 3 is a schematic cross-sectional view of a processing apparatus.

[0017] Figure 4 FIG. 4 is a schematic plan view of an upper surface of a chuck table.

[0018] Figure 5 (A) of FIG. 5 is a schematic cross-sectional view of a case where a front surface side of an object to be processed is captured with a camera unit. Figure 5 (B) of FIG. 5 is a schematic cross-sectional view in which a light-transmissive portion is enlarged.

[0019] Figure 6 (A) of FIG. 6 is a schematic cross-sectional view of a case where a front surface side of an object to be processed is captured with a camera unit. Figure 6 (B) of FIG. 6 is a schematic cross-sectional view in which a light-transmissive portion is enlarged.

[0020] REFERENCE NUMERALS

[0021] 1: wafer; 1a, 11a: front surface; 1b, 11b: back surface; 1c: second region; 3: metal film; 5, 15: device; 7, 17: division predetermined line; 9: package substrate; 13: metal frame; 19: mark; 21: sealing resin; 23: adhesive tape; 25: annular frame; 27: frame unit; 2: cutting device; 4: base; 4a, 4b, 4c: opening; 8: cassette support table; 10: cassette; 12: guide rail; 14: table cover; 16: dust and drip prevention cover; 18: chuck table; 18a: holding surface; 18b: jig; 18c: upper surface; 18d: light-transmissive member; 18e: frame; 18f: table base; 20: support structure; 22a, 22b: moving unit; 24a, 24b: processing unit; 26: Y-axis guide rail; 28a, 28b: Y-axis moving plate; 30a, 30b: Y-axis ball screw; 32a: Y-axis pulse motor; 34a, 34b: Z-axis guide rail; 36a, 36b: Z-axis moving plate; 38a, 38b: Z-axis ball screw; 40a, 40b: Z-axis pulse motor; 44a: cutting tool; 46a, 46b: camera unit; 48: cleaning unit; 50: suction source; 52: switching section; 54: suction path; 56: holding section; 58: light-transmissive section; 58a: first region; 58b: third region; 58c: exposed surface; 60, 62, 66: mirror surface; 64: external mirror. DETAILED DESCRIPTION

[0022] An embodiment of one mode of the present application will be described with reference to the drawings. In the processing device of the present embodiment, a plate-shaped workpiece is processed along a division predetermined line provided in the workpiece. First, the workpiece processed by the processing device of the present embodiment will be described.

[0023] The workpiece processed by the processing device of the present embodiment is, for example, a substantially circular plate-shaped wafer formed of Si (silicon), SiC (silicon carbide), GaN (gallium nitride), GaAs (gallium arsenide), or another semiconductor material. Alternatively, the workpiece is a plate-shaped substrate or the like composed of sapphire, quartz, glass, ceramic, or the like. The glass is, for example, alkali glass, non-alkali glass, soda-lime glass, lead glass, borosilicate glass, quartz glass, or the like.

[0024] As an example of the workpiece, a substantially circular plate-shaped wafer 1 formed of a semiconductor material is shown in (A) of FIG. 1. In addition, a wafer 1 formed of a semiconductor material is shown in (B) of FIG. 1. In (A) and (B) of FIG. 1, the wafer 1 is shown as a wafer 1a having a front surface 1a and a back surface 1b. The wafer 1 is, for example, a wafer 1a having a front surface 1a and a back surface 1b. The wafer 1 is, for example, a wafer 1a having a front surface 1a and a back surface 1b. Figure 1 A perspective view of the back surface 1b side of the substantially circular plate-shaped wafer 1 formed of a semiconductor material is schematically shown in (A) of FIG. 1. In addition, a wafer 1 formed of a semiconductor material is shown in (B) of FIG. 1. In (A) and (B) of FIG. 1, the wafer 1 is shown as a wafer 1a having a front surface 1a and a back surface 1b. The wafer 1 is, for example, a wafer 1a having a front surface 1a and a back surface 1b. The wafer 1 is, for example, a wafer 1a having a front surface 1a and a back surface 1b. Figure 1A cross-sectional view of wafer 1 is schematically shown in (B). Multiple devices 5, such as ICs (Integrated Circuits) and LSIs (Large Scale Integrations), are formed on the front side 1a of wafer 1. Pre-defined dicing lines 7 are provided between the devices 5 in wafer 1. Furthermore, when wafer 1 is diced along the pre-defined dicing lines 7 using a processing apparatus, individual device chips can be formed.

[0025] In the processing apparatus, in order to process the workpiece such as the wafer 1 along the dicing predetermined line 7, a camera unit for detecting the dicing predetermined line 7 is provided near the processing unit that processes the workpiece. When detecting the dicing predetermined line 7, firstly, the camera unit takes an image of the upper surface of the wafer 1 to detect specific patterns of the components, electrodes, wiring, etc. included in the device 5, or patterns of TEG (Test Element Group) etc. that are superimposed on the dicing predetermined line 7.

[0026] Since the positional relationship between these patterns on the front side 1a of the wafer 1 (workpiece) and the predetermined dividing line 7 is predetermined, the position of the predetermined dividing line 7 can be determined based on the position of these patterns. Then, the processing unit processes the wafer 1 along the determined predetermined dividing line 7. That is, the processing unit processes the wafer 1 based on the image captured by the camera unit.

[0027] Furthermore, the workpiece processed by the processing apparatus of this embodiment is not limited to this. For example, in Figure 2 (A) and Figure 2 (B) schematically shows a package substrate 9 in which multiple devices 15 are sealed with sealing resin (molding resin) 21. Figure 2 (A) is a schematic perspective view of the back side 11b of the packaging substrate 9. Figure 2 (B) is a perspective view schematically showing the front 11a side of the packaging substrate 9.

[0028] The packaging substrate 9 has a rectangular metal frame 13 that holds a plurality of devices 15. Furthermore, a plurality of devices 15 are arranged longitudinally and transversely inside the metal frame 13, and the plurality of devices 15 are encapsulated by sealing resin 21.

[0029] In addition, a mark 19 indicating the position of the division line 17 is formed at the end portion of each division line 17 on the outer peripheral portion of the front surface 11a side of the package substrate 9. When the mark 19 is detected by the camera unit of the processing apparatus, the position of the division line 17 can be determined. Further, when the package substrate 9 is processed and divided along the division line 17 by the processing apparatus, each device chip sealed by the sealing resin 21 can be obtained.

[0030] In addition, as shown in (A) of FIG. 1 and (B) of FIG. 2, the wafer 1 (work) is sometimes processed in a state where the front surface la of the wafer 1 faces downward and the back surface lb side thereof faces upward. In this case, since the front surface la side of the wafer 1 cannot be imaged by the camera unit, the division line 7 cannot be detected. Therefore, it is considered that a camera element capable of detecting light of a wavelength that can pass through the wafer 1 is used in the camera unit, and the front surface la side of the wafer 1 is imaged through the wafer 1. Figure 1 Figure 1 However, as shown in (A) of FIG. 1 and (B) of FIG. 2, a metal film 3 is sometimes formed on the back surface lb side of the wafer 1 for various purposes. Alternatively, a resin film is sometimes formed instead of the metal film 3. Further, there is a case where light of a wavelength that can pass through the wafer 1 cannot pass through these films. In these cases, the front surface la side of the wafer 1 still cannot be imaged by the camera unit.

[0031] However, as shown in (A) of FIG. 1 and (B) of FIG. 2, a metal film 3 is sometimes formed on the back surface lb side of the wafer 1 for various purposes. Alternatively, a resin film is sometimes formed instead of the metal film 3. Further, there is a case where light of a wavelength that can pass through the wafer 1 cannot pass through these films. In these cases, the front surface la side of the wafer 1 still cannot be imaged by the camera unit. Figure 1 Figure 1 In addition, as shown in (A) of FIG. 1 and (B) of FIG. 2, the wafer 1 (work) is sometimes processed in a state where the front surface la of the wafer 1 faces downward and the back surface lb side thereof faces upward. In this case, since the front surface la side of the wafer 1 cannot be imaged by the camera unit, the division line 7 cannot be detected. Therefore, it is considered that a camera element capable of detecting light of a wavelength that can pass through the wafer 1 is used in the camera unit, and the front surface la side of the wafer 1 is imaged through the wafer 1.

[0032] In addition, as shown in (A) of FIG. 1 and (B) of FIG. 2, the wafer 1 (work) is sometimes processed in a state where the front surface la of the wafer 1 faces downward and the back surface lb side thereof faces upward. In this case, since the front surface la side of the wafer 1 cannot be imaged by the camera unit, the division line 7 cannot be detected. Therefore, it is considered that a camera element capable of detecting light of a wavelength that can pass through the wafer 1 is used in the camera unit, and the front surface la side of the wafer 1 is imaged through the wafer 1. Figure 2 Therefore, in the processing apparatus of the present embodiment, a light-transmitting portion is provided on the chuck table that holds the work, and the lower surface of the work is observed by the camera unit through the light-transmitting portion. Hereinafter, the processing apparatus of the present embodiment will be described.

[0033] is a perspective view schematically showing a cutting apparatus 2 as an example of the processing apparatus of the present embodiment. However, the processing apparatus is not limited to the cutting apparatus 2. In addition, as an example of the work, the wafer 1 is schematically shown in (A) of FIG. 1. However, the work is not limited to the wafer 1. Figure 3 Figure 3

[0034] ​​​​When wafer 1 is loaded into cutting device 2, adhesive tape 23, which is applied in advance to close the opening of annular frame 25 formed of metal or the like, is attached to wafer 1. Then, with the wafer 1, adhesive tape 23, and annular frame 25 integrated into frame unit 27, wafer 1 is loaded into cutting device 2 for cutting. Then, the individual device chips formed by the wafer 1 being cut are supported by adhesive tape 23, and then each device chip is picked up from adhesive tape 23.

[0035] The cutting device 2 has a base 4 that supports various structural elements. An opening 4a is formed at the front corner of the base 4, and a cassette support 8, which is raised and lowered by a lifting mechanism (not shown), is disposed within this opening 4a. A cassette 10 for holding multiple wafers 1 is mounted on the upper surface of the cassette support 8. Furthermore, in... Figure 3 For ease of explanation, only the outline of box 10 is shown in the image.

[0036] A rectangular opening 4b is formed on the side of the box support 8 along the X-axis direction (front-back direction, machining feed direction). A ball screw-type X-axis moving mechanism (not shown), a worktable cover 14 covering the upper part of the X-axis moving mechanism, and a dust and drip protection cover 16 are arranged within the opening 4b. The X-axis moving mechanism has an X-axis moving worktable (not shown) covered by the worktable cover 14, thereby allowing the X-axis moving worktable to move along the X-axis direction.

[0037] A table base 18f (see reference) is provided on the upper surface of the X-axis moving table in such a way that it protrudes from the table cover 14. Figure 5 (A) etc.), a chuck worktable 18 is provided on the upper end of the worktable base 18f. The chuck worktable 18 has the function of attracting and holding the workpiece placed on the upwardly exposed holding surface 18a.

[0038] The chuck table 18 is connected to a rotary drive source (not shown) such as an electric motor and rotates about a rotation axis that is approximately parallel to the Z-axis direction (vertical direction). In addition, the chuck table 18 moves along the X-axis direction together with the X-axis moving table and the table cover 14 via an X-axis moving mechanism.

[0039] exist Figure 5 (A) schematically shows a cross-sectional view of an example of a chuck stage 18. The chuck stage 18 has a porous holding portion 56 with the same diameter as the wafer 1 and a frame 18e covering the outer peripheral side and bottom side of the holding portion 56. An attraction path 54 is formed inside the chuck stage 18, one end of which is connected to an attraction source 50 such as an ejector disposed outside the chuck stage 18. The other end of the attraction path 54 reaches the holding portion 56.

[0040] A switching unit 52 is provided on the suction path 54. When the switching unit 52 is operated, the connection state and separation state of the suction source 50 and the holding part 56 are switched. Moreover, when holding the wafer 1 using the chuck stage 18, firstly, the frame unit 27 is placed on the holding surface 18a of the chuck stage 18. Then, the switching unit 52 is operated to connect the suction source 50 and the holding part 56 via the suction path 54, so that the negative pressure generated by the suction source 50 acts on the wafer 1 through the adhesive tape 23.

[0041] In the holding surface 18a of the chuck stage 18, the upper surface 18c of the holding portion 56 is exposed. The upper surface 18c of the holding portion 56 has a diameter equal to that of the wafer 1, which is the workpiece, and is formed to be substantially parallel to the X-axis and Y-axis directions. In addition, four clamps 18b are provided around the chuck stage 18 for fixing the annular frame 25 supporting the wafer 1 from all sides.

[0042] The cutting device 2 has a transport unit (not shown) in the area adjacent to the opening 4b for transporting the wafer 1 to the chuck stage 18, etc. A temporary placement mechanism for temporarily placing the wafer 1 is provided near the side of the cassette support 8. The temporary placement mechanism includes, for example, a pair of guide rails 12 that approach or move away from the cassette while maintaining a state parallel to the Y-axis direction (indexing feed direction). The pair of guide rails 12 clamp the wafer 1 pulled from the cassette 10 by the transport unit in the X-axis direction and align the wafer 1 with a predetermined position.

[0043] The wafer 1, aligned with the specified position, is lifted by the transfer unit and transported to the chuck stage 18. At this time, the pair of guide rails 12 are separated, allowing the wafer 1 to pass between the pair of guide rails 12.

[0044] Above the chuck stage 18 are a first processing unit 24a and a second processing unit 24b that use annular cutting tools to cut the wafer 1. Figure 3 As shown, the first machining unit 24a has an annular cutting tool 44a. In addition, a gate-shaped support structure 20 for supporting the first machining unit 24a and the second machining unit 24b is arranged on the upper surface of the base 4 in a manner that spans the opening 4b.

[0045] A first moving unit 22a and a second moving unit 22b are provided on the upper part of the front surface of the support structure 20. The first moving unit 22a moves the first processing unit 24a along the Y-axis and Z-axis directions, and the second moving unit 22b moves the second processing unit 24b along the Y-axis and Z-axis directions.

[0046] The first moving unit 22a has a Y-axis moving plate 28a, and the second moving unit 22b has a Y-axis moving plate 28b. The Y-axis moving plate 28a and the Y-axis moving plate 28b are slidably mounted to a pair of Y-axis rails 26 disposed along the Y-axis direction on the front surface of the support structure 20.

[0047] A nut portion (not shown) to which a Y-axis ball screw 30a is screwed in substantially parallel to the Y-axis rail 26 is provided on the back surface side (rear surface side) of the Y-axis moving plate 28a. In addition, a nut portion (not shown) to which a Y-axis ball screw 30b is screwed in substantially parallel to the Y-axis rail 26 is provided on the back surface side (rear surface side) of the Y-axis moving plate 28b.

[0048] A Y-axis pulse motor 32a is connected to one end portion of the Y-axis ball screw 30a. By rotating the Y-axis ball screw 30a with the Y-axis pulse motor 32a, the Y-axis moving plate 28a moves in the Y-axis direction along the Y-axis rail 26. In addition, a Y-axis pulse motor (not shown) is connected to one end portion of the Y-axis ball screw 30b. By rotating the Y-axis ball screw 30b with the Y-axis pulse motor, the Y-axis moving plate 28b moves in the Y-axis direction along the Y-axis rail 26.

[0049] A pair of Z-axis rails 34a is disposed along the Z-axis direction on the front surface side (front surface side) of the Y-axis moving plate 28a, and a pair of Z-axis rails 34b is disposed along the Z-axis direction on the front surface side (front surface side) of the Y-axis moving plate 28b. In addition, a Z-axis moving plate 36a is slidably mounted to the pair of Z-axis rails 34a, and a Z-axis moving plate 36b is slidably mounted to the pair of Z-axis rails 34b.

[0050] A nut portion (not shown) to which a Z-axis ball screw 38a is screwed in a manner along a direction substantially parallel to the Z-axis rail 34a is provided on the back surface side (rear surface side) of the Z-axis moving plate 36a. A Z-axis pulse motor 40a is connected to one end portion of the Z-axis ball screw 38a, and by rotating the Z-axis ball screw 38a with the Z-axis pulse motor 40a, the Z-axis moving plate 36a moves in the Z-axis direction along the Z-axis rail 34a.

[0051] A nut portion (not shown) to which a Z-axis ball screw 38b is screwed in a manner along a direction substantially parallel to the Z-axis rail 34b is provided on the back surface side (rear surface side) of the Z-axis moving plate 36b. A Z-axis pulse motor 40b is connected to one end portion of the Z-axis ball screw 38b, and by rotating the Z-axis ball screw 38b with the Z-axis pulse motor 40b, the Z-axis moving plate 36b moves in the Z-axis direction along the Z-axis rail 34b.

[0052] A first processing unit 24a is provided below the Z-axis moving plate 36a. A camera unit 46a is provided adjacent to the first processing unit 24a, and this camera unit 46a is used to photograph the wafer 1 held by the chuck stage 18. Additionally, a second processing unit 24b is provided below the Z-axis moving plate 36b. A camera unit 46b is provided adjacent to the second processing unit 24b, and this camera unit 46b is used to photograph the wafer 1 held by the chuck stage 18.

[0053] The positions of the first processing unit 24a and the camera unit 46a in the Y-axis and Z-axis directions are controlled by the first moving unit 22a, and the positions of the second processing unit 24b and the camera unit 46b in the Y-axis and Z-axis directions are controlled by the second moving unit 22b. That is, the positions of the first processing unit 24a and the second processing unit 24b are controlled independently.

[0054] An opening 4c is formed on the side opposite to the opening 4a, opposite to the opening 4b. A cleaning unit 48 for cleaning the wafer 1 is disposed within the opening 4c. The wafer 1, which has undergone the prescribed processing on the chuck stage 18, is cleaned by the cleaning unit 48. The wafer 1, after being cleaned by the cleaning unit 48, is then placed back into the cassette 10.

[0055] In the frame unit 27 containing the wafer 1, the wafer 1 is adhered to the adhesive tape 23 from the front side 1a. Therefore, when the wafer 1 is attracted and held by the chuck stage 18 through the adhesive tape 23, the back side 1b of the wafer 1 is exposed upwards. Here, in the cutting device 2, which is the processing apparatus of this embodiment, a light-transmitting portion 58 (see reference) is formed on the chuck stage 18. Figure 5 (A, etc.). Moreover, using the camera units 46a and 46b arranged above the chuck worktable 18, the front 1a side of the wafer 1 is photographed through the light-transmitting part 58.

[0056] like Figure 5 As shown in (A), the chuck stage 18 includes a holding portion 56 that applies negative pressure to the wafer 1 and a light-transmitting portion 58 that allows light to pass through. The light-transmitting portion 58 is a space formed in the chuck stage 18.

[0057] Moreover, such as Figure 4 As shown, the upper surface 18c of the holding portion 56 forms part of the holding surface 18a of the chuck stage 18. Furthermore, another part of the holding surface 18a of the chuck stage 18 is formed by a first region 58a of the light-transmitting portion 58 that overlaps with the wafer 1 held by the chuck stage 18. Moreover, yet another part of the holding surface 18a is formed by a third region 58b of the light-transmitting portion 58 that does not overlap with the wafer 1 held by the chuck stage 18.

[0058] Figure 5 (B) is a cross-sectional view schematically showing the light-transmitting portion 58 enlarged. The light-transmitting portion 58 has a first mirror surface 60 below the first region 58a and a second mirror surface 62 below the third region 58b. The first mirror surface 60 reflects light traveling from the first region 58a into the light-transmitting portion 58.

[0059] For example, the first mirror surface 60 reflects the light toward the second mirror surface 62 disposed radially outward of the chuck table 18. Also, the second mirror surface 62 reflects the light reflected by the first mirror surface 60 toward the third region 58b.

[0060] Here, the first mirror surface 60 and the second mirror surface 62 can be formed, for example, by providing a mirror inclined in a specific direction in a space inside the light-transmitting portion 58. Alternatively, they can be formed by forming a wall surface inclined in a specific direction in the space and polishing or applying a metal layer or the like mirror surface processing to the wall surface.

[0061] In addition, a light source not shown can be provided on a wall surface of the light-transmitting portion 58. Alternatively, the light source can be provided outside the light-transmitting portion 58, for example, adjacent to the camera units 46a, 46b.

[0062] Further, the light-transmitting portion 58 can have a light-transmitting member 18d that partitions the space inside from the outside. For example, as shown in (A) of FIG. 8, the light-transmitting member 18d is provided across the first region 58a and the third region 58b of the light-transmitting portion 58, and as shown in (B) of FIG. 8, the light-transmitting member 18d is provided across the first region 58a and the third region 58b of the light-transmitting portion 58. Figure 4 Figure 5 Further, the light-transmitting portion 58 can have a light-transmitting member 18d that partitions the space inside from the outside. For example, as shown in (A) of FIG. 8, the light-transmitting member 18d is provided across the first region 58a and the third region 58b of the light-transmitting portion 58, and as shown in (B) of FIG. 8, the light-transmitting member 18d is provided across the first region 58a and the third region 58b of the light-transmitting portion 58.

[0063] Here, the light-transmitting member 18d can transmit light of a wavelength detected when the camera units 46a, 46b take an image of the front surface la side of the wafer 1. For example, in the case where the camera units 46a, 46b detect visible light, a material such as glass or transparent resin can be used. In the case where the camera units 46a, 46b are infrared cameras, a member that transmits infrared light can be used for the light-transmitting member 18d.

[0064] Figure 5 ​(A) is a sectional view schematically showing a case where the front surface la side of the wafer 1 is imaged by the camera units 46a, 46b. When the front surface la side of the wafer 1 as a workpiece is imaged by the camera units 46a, 46b, first, the camera units 46a, 46b are positioned above the third region 58b of the light-transmitting portion 58. Next, the light source is operated, and the like, and light is irradiated to the second region 1c of the front surface la of the wafer 1 opposite to the first region 58a.

[0065] At this time, the light is reflected by the second region 1c of the wafer 1, and travels from the first region 58a to the inside of the light-transmitting portion 58 through the adhesive tape 23 and the light-transmitting member 18d. Then, the light is reflected by the first mirror surface 60 toward the second mirror surface 62, and is reflected by the second mirror surface 62 toward the outside of the light-transmitting portion 58 from the third region 58b. The light again travels to the camera units 46a, 46b through the light-transmitting member 18d and the adhesive tape 23.

[0066] That is, the camera units 46a, 46b can detect the light reflected by the surface of the workpiece (wafer 1) held by the chuck table 18 opposite to the holding surface 18a and traveling in the light-transmitting portion 58. Therefore, in the cutting apparatus 2 as the processing apparatus of the present embodiment, since the light-transmitting portion 58 is formed on the chuck table 18, the lower surface of the workpiece can be imaged by the camera units 46a, 46b through the light-transmitting portion 58.

[0067] In addition, since the wafer 1 is held by the chuck table 18, the light-transmitting portion 58 cannot be formed on the entire region of the holding surface 18a. That is, in the processing apparatus of the present embodiment, the entire region of the front surface la (lower surface) of the wafer 1 cannot be imaged.

[0068] However, the device 5, and the like, formed on the front surface la of the wafer 1 can be detected from the imaged image formed by the camera units 46a, 46b, and thus the position and direction of the division predetermined line 7 can be determined. Therefore, the wafer 1 can be processed along the division predetermined line 7 by the processing units 24a, 24b based on the imaging result of the camera units 46a, 46b. In particular, when a plurality of light-transmitting portions 58 are formed on the chuck table 18, the position and direction of the division predetermined line 7 can be detected with higher accuracy.

[0069] In the processing apparatus of this embodiment, when photographing the front side 1a of the wafer 1, it is not necessary to locally remove the metal film 3 or the like formed on the back side 1b of the wafer 1, and therefore a processing apparatus for removing the metal film 3 or the like is not required. Moreover, by simply positioning the camera units 46a and 46b above the third region 58b of the light-transmitting portion 58 to photograph the front side 1a of the wafer 1, the position and direction of the predetermined dividing line 7 can be easily detected in a short time.

[0070] Furthermore, the cutting device 2 of the machining apparatus in this embodiment does not require the light reflected by the first mirror 60 inside the light-transmitting portion 58 to be reflected by the second mirror 62 disposed inside the light-transmitting portion 58. That is, the light may travel radially outward toward the chuck table 18 and be reflected upward by an external reflecting mirror disposed outside the chuck table 18. Hereinafter, using Figure 6 (A) and Figure 6 (B) A modified example of the processing apparatus (cutting device 2) of this embodiment will be described.

[0071] Figure 6 (A) is a schematic cross-sectional view showing the situation where the front side 1a of the wafer 1 is photographed using camera units 46a and 46b. Additionally, Figure 6 (B) is a schematic cross-sectional view showing the light-transmitting portion 58 magnified. However, in Figure 6 (A) and Figure 6 In (B), for ease of explanation, the adhesive tape 23 and the like that pasted on the front side 1a of the wafer 1 are omitted.

[0072] Figure 6 (A) and Figure 6 The light-transmitting portion 58 shown in (B) does not have a second mirror surface 62. Furthermore, the cutting device 2 has an external reflector 64 disposed radially outward of the chuck table 18. The external reflector 64 may be disposed, for example, on the side of the support structure 20 of the cutting device 2. Alternatively, the external reflector 64 may be disposed on the inner wall surface of the opening 4b of the base 4. However, the location of the external reflector 64 is not limited to these locations. Moreover, the light-transmitting portion 58 has an exposed surface 58c that protrudes from the side of the chuck table 18.

[0073] like Figure 6 As shown in (B), a light-transmitting component 18d is provided on the exposed surface 58c and the first region 58a of the light-transmitting part 58, thereby suppressing the intrusion of processing chips and the like into the internal space of the light-transmitting part 58.

[0074] When the front surface la side of the wafer 1 held by the chuck table 18 is imaged, the camera units 46a, 46b are positioned above the outer mirror 64. Then, the chuck table 18 is moved and rotated so that the exposed surface 58c of the light-transmissive portion 58 opposes the outer mirror 64.

[0075] Next, the light source inside or outside the light-transmissive portion 58 is activated to irradiate the second region 1c of the front surface la of the wafer 1 that opposes the first region 58a of the light-transmissive portion 58 with light. Then, the light reflected by the second region 1c travels to the light-transmissive portion 58 from the first region 58a and is reflected by the first mirror surface 60 disposed below the first region 58a toward the direction of the radial outer side of the chuck table 18.

[0076] Then, the light travels to the outside of the light-transmissive portion 58 from the exposed surface 58c and is reflected by the mirror surface 66 of the outer mirror 64 to the camera units 46a, 46b positioned above. The camera units 46a, 46b can image the second region 1c of the front surface la of the wafer 1 by detecting the light. In this way, in the modified example of the processing apparatus of the present embodiment, the front surface la of the wafer 1 facing downward can also be imaged, and thus the position and direction of the separation intended line 7 of the wafer 1 can be detected.

[0077] As described above, according to the processing apparatus of the present embodiment, the face of the workpiece held by the chuck table 18 that opposes the chuck table 18 can be easily imaged by the camera units 46a, 46b. Therefore, the processing unit of the processing apparatus can detect the position and direction of the separation intended line 7 from the imaging result of the camera units 46a, 46b, and thus the workpiece can be processed along the separation intended line 7.

[0078] In addition, the present application is not limited to the description of the above-described embodiments, and various modifications can be made to implement it. For example, in the above-described embodiments, the case where the space inside the light-transmissive portion 58 is closed by the light-transmissive member 18d is described. However, one mode of the present application is not limited to this. That is, the light-transmissive portion 58 can also be filled with the light-transmissive member 18d.

[0079] In this case, the intrusion of processing chips and the like into the inside of the light-transmissive portion 58 is also prevented by the light-transmissive member 18d. Moreover, since there is no interface between the space inside the light-transmissive portion 58 and the light-transmissive member 18d, the occurrence of optical phenomena at the interface in the travel path of the light reflected from the lower surface of the workpiece is suppressed. In this case, the light easily reaches the camera units 46a, 46b more stably, and thus the lower surface of the workpiece can be imaged more clearly.

[0080] In order to form such a light-transmitting portion 58, for example, a hole capable of accommodating the light-transmitting portion 58 is formed in the upper surface of the chuck table 18, and a light-transmitting member 18d shaped like the light-transmitting portion 58 is prepared. Then, a metal film or the like is formed on the surface below the first region 58a of the light-transmitting member 18d to form the first mirror surface 60. At this time, the second mirror surface 62 can also be formed on the surface below the third region 58b of the light-transmitting portion 58. Then, the light-transmitting portion 58 is embedded in the hole formed in the upper surface of the chuck table 18.

[0081] Alternatively, a hole capable of accommodating the light-transmitting portion 58 can also be formed in the upper surface of the chuck table 18, and after the first mirror surface 60 or the like is formed on the inner wall of the hole, liquid resin is injected into the hole, and the light-transmitting portion 58 is formed by curing the resin. In this way, the light-transmitting portion 58 filled with the light-transmitting member 18d can be formed in the chuck table 18 by various methods. That is, the selection items of the method of forming the light-transmitting portion 58 are increased.

[0082] Further, in the above-described embodiment, a case in which the light-transmitting portion 58 is formed on the outer peripheral side of the chuck table 18 is described, but the machining device of the present embodiment is not limited thereto. That is, the first region 58a of the light-transmitting portion 58 can include the center of the holding surface 18a of the chuck table 18, or can be disposed in correspondence with the disposition of the main photographing portion of the workpiece held by the chuck table 18.

[0083] In addition, in the above-described embodiment, a case in which the lower surface side of the workpiece on which a metal film 3 or the like is formed on the upper surface is photographed by the camera units 46a and 46b is described, but the workpiece machined by the machining device of the present embodiment is not limited thereto. That is, the metal film 3 or the like can not be formed on the upper surface of the workpiece. For example, in a case in which there is a problem in photographing the lower surface side of the workpiece by the workpiece, the machining device of the present embodiment can avoid such a problem.

[0084] Further, the configuration, method, and the like of the above-described embodiment and modified example can be appropriately changed and implemented within a range not departing from the object of the present application.

Claims

1. A processing apparatus having: a chuck table having a holding surface exposed upward and attracting and holding a plate-shaped work placed on the holding surface; a camera unit provided above the chuck table and photographing the work held by the chuck table; and a processing unit processing the work based on a result of photographing by the camera unit, characterized in that the chuck table includes: a holding portion whose upper surface constitutes a part of the holding surface and applies negative pressure to the work placed on the holding surface; and a light-transmitting portion through which light passes, the light-transmitting portion includes a first region overlapping the work held by the chuck table and constituting another part of the holding surface, the light-transmitting portion has a first mirror surface reflecting light traveling from the first region into the light-transmitting portion, the camera unit can photograph a second region of the work opposite the first region by detecting light traveling from the first region into the light-transmitting portion and reflected by the first mirror surface, the processing apparatus further has an external mirror provided radially outward of the chuck table, the light-transmitting portion has an exposed surface exposed to a side surface of the chuck table, the camera unit is positioned above the external mirror when detecting the light, and the external mirror reflects the light traveling from the exposed surface of the light-transmitting portion toward the camera unit.

2. The processing apparatus according to claim 1, characterized in that the light-transmitting portion further includes a third region not overlapping the work held by the chuck table and constituting still another part of the holding surface, the camera unit is positioned above the third region when detecting the light, and the light-transmitting portion further has a second mirror surface reflecting the light reflected by the first mirror surface toward the camera unit through the third region.

3. The processing apparatus according to claim 1, characterized in that the light-transmitting portion has a light-transmitting member partitioning a space inside the light-transmitting portion from outside.

4. The processing apparatus according to claim 1, characterized in that the light-transmitting portion is filled with a light-transmitting member. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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