Robot hand and processing equipment

Abstract

To shorten the transport time by transporting wafers that have a ring-shaped protrusion on the outside of a recess. [Solution] The robot hand (50) suctions and holds a wafer (200) which has a recess (202) in the central part of its back surface (201) and a ring-shaped protrusion (203) outside the recess. The robot hand is configured to include a protrusion suction unit (65) that sucks up the protrusion on one side, and a support unit (66) disposed to the side of the protrusion suction unit to support the protrusion suction unit. The robot hand (50) is mounted on a robot (18), and under the control of a control unit (57), the protrusion suction unit sucks up the protrusion of the wafer and transports the wafer from the cleaning unit (39) to the cassette (15) of the cassette stage (13).

Description

Technical Field

[0001] The present invention relates to a robot hand for sucking and holding a wafer and a processing apparatus.

Background Art

[0002] Patent Document 1 discloses a grinding apparatus that grinds the center of a wafer to form a ring-shaped convex portion on the outer periphery. In the grinding apparatus of Patent Document 1, the wafer before grinding is transported and placed on a chuck table by a transporting means, and after the grinding process, the wafer held on the chuck table is transported by a transporting means. The transporting means of Patent Document 1 includes a holding pad, an operating arm that supports the holding pad, and a rotational driving means that rotates the base end portion of the operating arm.

[0003] After the grinding process, the wafer is transported by a transporting means to a spinner table of a spinner cleaning unit, and the wafer is cleaned by spraying cleaning water onto the wafer while rotating the spinner table that holds the wafer. When storing the wafer in a cassette after such cleaning, a robot is used. For example, a robot hand attached to the tip of the robot holds the lower surface of the wafer and stores it in the cassette.

[0004] When the spinner table is sized to support the entire lower surface of the wafer, the upper surface of the wafer is held using the holding pad in the transporting means of Patent Document 1, and after lifting the wafer from the spinner table, the robot hand holds the lower surface of the wafer. In other words, the wafer is transferred from the holding pad of the transporting means to the robot hand.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, the aforementioned method of switching the wafers has the problem of taking a long time to transport them.

[0007] The present invention has been made in view of the above, and one of its objectives is to provide a robot hand and processing apparatus that can shorten the transport time by transporting wafers equipped with a ring-shaped protrusion on the outside of a recess. [Means for solving the problem]

[0008] A robot hand according to one aspect of the present invention is a robot hand for suction holding a wafer having a recess in the central part of one surface and a ring-shaped protrusion outside the recess, comprising a protrusion suction part that sucks the protrusion on one surface side and a support part disposed to the side of the protrusion suction part to support the protrusion suction part.

[0009] Furthermore, a processing apparatus according to one aspect of the present invention comprises a robot equipped with the robot hand and holding at least one side of a wafer; a chuck table that holds the other side of the wafer; a processing unit that forms a recess in the central part of the one side of the wafer and forms a ring-shaped protrusion outside the recess; a cleaning unit that holds the other side of the wafer and cleans the one side; a cassette stage on which a cassette for storing the wafer is placed; and a control unit, wherein the control unit uses the protrusion suction unit of the robot hand to suck the protrusion of the wafer and transport it from the cleaning unit to the cassette on the cassette stage. [Effects of the Invention]

[0010] According to the present invention, when transporting a wafer having a ring-shaped protrusion, a robot can be used from the time the wafer is held until it is stored, eliminating the need to change the wafer's grip as in the conventional method and thus shortening the transport time. [Brief explanation of the drawing]

[0011] [Figure 1]This is a perspective view of the grinding apparatus according to the embodiment. [Figure 2] This is a cross-sectional view of the wafer after grinding. [Figure 3] Figure 3A is a schematic perspective view of the robot hand according to the embodiment, and Figure 3B is a schematic perspective view of the robot hand in Figure 3A in an inverted state. [Figure 4] Figure 4A is a cross-sectional view along line AA of Figure 3A, and Figure 4B is a cross-sectional view along line BB of Figure 3B. [Modes for carrying out the invention]

[0012] The grinding apparatus to which the robot hand according to the embodiment is applied will be described below with reference to the attached drawings. Note that the grinding apparatus according to the embodiment is not limited to the configuration shown below and can be modified as appropriate.

[0013] Figure 1 is a perspective view of the grinding apparatus according to the embodiment. First, the overall configuration of the grinding apparatus 1 will be explained with reference to Figure 1. The X-axis, Y-axis, and Z-axis directions shown in Figure 1 are perpendicular to each other. The X-axis and Y-axis directions are approximately horizontal, and the Z-axis direction is vertical. In addition, in the following figures, the front side in the X-axis direction may be referred to as the +X side and the rear side as the -X side, the right side in the Y-axis direction as the +Y side and the left side as the -Y side, and the upper side in the Z-axis direction as the +Z side and the lower side as the -Z side.

[0014] The grinding apparatus 1 shown in Figure 1 is an example of a processing apparatus to which the present invention is applied. However, the present invention is not limited to the grinding apparatus 1 and can be applied to other processing apparatuses equipped with various tables, processing mechanisms, transport mechanisms, etc. The grinding apparatus 1 is configured to perform a series of processes on a wafer 200, including loading, grinding, cleaning, and unloading.

[0015] As shown in Figure 1, the grinding apparatus 1 is an example of a processing apparatus equipped with a robot hand 50 according to an embodiment, and is an apparatus for grinding a wafer 200.

[0016] FIG. 2 is a cross-sectional view of the wafer after grinding. Wafer 200 is an example of a plate-shaped workpiece, and has a circular recess 202 in the central portion of the back surface 201 which is one surface, and a ring-shaped protrusion 203 outside the recess 202, and the other surface is the front surface 204. The wafer 200 to be ground can be exemplified by a disc-shaped semiconductor wafer or an optical device wafer based on silicon, sapphire, gallium, etc.

[0017] The wafer 200 includes a device region 205 and an outer peripheral surplus region 206 surrounding the device region 205. A plurality of devices (not shown) are formed in the device region 205 on the front surface 204 of the wafer 200, and are protected by a protective tape 207 adhered to the front surface 204.

[0018] In the wafer 200 after grinding, the recess 202 is formed by thinning the back surface 201 side of the device region 205. Further, in the wafer 200 after grinding, the protrusion 203 is formed outside the recess 202 without thinning the outer peripheral surplus region 206.

[0019] Next, returning to FIG. 1, the grinding apparatus 1 will be described. In the grinding apparatus 1, two cassette stages 12 and 13 are provided on the first apparatus base 11, and cassettes 14 and 15 for storing the wafers 200 are placed on each of the cassette stages 12 and 13.

[0020] The wafers 200 accommodated in the cassettes 14 and 15 are transported to the temporary placement mechanism 19 by the robot 18 and aligned. Thereafter, the wafer 200 temporarily placed in the temporary placement mechanism 19 is transported to the chuck table 22 by the loading mechanism 21 and held. The robot 18 and the loading mechanism 21 will be described later.

[0021] The chuck table 22 is provided in three numbers at intervals of 120° on a turntable 25 that is rotatably installed on a second device base 24. A holding surface 26 formed on the upper surface of each chuck table 22 holds the surface 204 of the wafer 200 via a protective tape 207. The holding surface 26 of the chuck table 22 is formed by a disk-shaped porous plate that communicates with a table suction source (not shown), and the wafer 200 is suction-held by the negative pressure of the table suction source.

[0022] By the intermittent rotation of the turntable 25 at intervals of 120 degrees, the three chuck tables 22 are positioned in the order of a loading / unloading position where the wafer 200 is loaded and unloaded, a rough grinding position facing below the rough grinding mechanism 31, and a finish grinding position facing below the finish grinding mechanism 32.

[0023] The rough grinding mechanism 31 and the finish grinding mechanism 32 constitute a processing unit 30 that performs grinding on the wafer 200 held on the holding surface 26 of the chuck table 22. At the rough grinding position, the wafer 200 is roughly ground to a predetermined thickness by the rough grinding mechanism 31. At the finish grinding position, the wafer 200 is finish ground to a finish thickness by the finish grinding mechanism 32. By the grinding by the rough grinding mechanism 31 and the finish grinding mechanism 32 (processing unit 30), a concave portion 202 is formed at the center of the back surface 201 of the wafer 200, and a ring-shaped convex portion 203 is formed outside the concave portion 202. At this time, the thickness of the wafer 200 is measured by a thickness measuring device 33 disposed at the center of the turntable 25.

[0024] On the second device base 24 and on the +Y side of the turntable 25, a column 35 having a hexagonal planar shape is erected, and the rough grinding mechanism 31 and the finish grinding mechanism 32 are supported via the column 35 so as to face the chuck table 22 of the turntable 25. Moving mechanisms 36 and 37 are provided between the column 35 and the rough grinding mechanism 31 and between the column 35 and the finish grinding mechanism 32, and the rough grinding mechanism 31 and the finish grinding mechanism 32 are provided so as to be movable in the horizontal and vertical directions by the moving mechanisms 36 and 37.

[0025] After grinding, the wafer 200 is unloaded from the chuck table 22 at the loading / unloading position by the unloading mechanism 38 and cleaned in the cleaning unit 39. The unloading mechanism 38 will be described later. The cleaned wafer 200 is loaded into cassettes 14 and 15 by the robot 18.

[0026] The cleaning unit 39 includes a spinner table 41 that holds the surface 204 side of the wafer 200, a rotating mechanism (not shown) that rotates the spinner table 41, and a cleaning water spray nozzle 42 that sprays cleaning water. The cleaning unit 39 rotates the spinner table 41 holding the wafer 200 and sprays cleaning water onto the wafer 200 from the cleaning water spray nozzle 42, thereby cleaning the back surface 201 side of the wafer 200, which is the upper surface. After the wafer 200 is cleaned, drying air is blown onto the wafer 200 from the cleaning water spray nozzle 42 or from a separately provided air spray nozzle to dry the wafer 200.

[0027] The transport mechanism 44 is comprised of a loading mechanism 21 and an unloading mechanism 38, which are provided between the washing unit 39 and the temporary storage mechanism 19. The loading mechanism 21 and the unloading mechanism 38 have similar configurations, and components common to both the loading mechanism 21 and the unloading mechanism 38 are denoted by the same reference numeral.

[0028] The loading mechanism 21 and the unloading mechanism 38 each have a transport pad 46 at the tip of a transport arm 45 that extends horizontally. The tip of the transport arm 45 is positioned in the center of the upper surface of the transport pad 46; in other words, the connection point between the transport pad 46 and the tip of the transport arm 45 is in the center of the upper surface.

[0029] The base end of the transport arm 45 is supported by a support shaft 47 that protrudes upward from the first device base 11. The support shaft 47 constitutes the movement mechanism for the transport arm 45 and the transport pad 46, and is rotatable around the Z-axis, causing the transport arm 45 and the transport pad 46 to pivot horizontally. The support shaft 47 can also be driven vertically to raise and lower the transport arm 45 and the transport pad 46, thereby changing the height of the transport pad 46.

[0030] The lower surface of the transport pad 46 has an adsorption surface formed by a porous plate that attracts and holds the wafer 200, and the adsorption surface is connected to a suction source (not shown). With the upper surface of the wafer 200 being attracted and held by the adsorption surface of the transport pad 46, the transport mechanism 44 (loading mechanism 21, unloading mechanism 38) transports the wafer 200 by moving the transport pad 46 via the transport arm 45 through the rotation and lifting operation of the support shaft 47.

[0031] Next, the robot 18 will be described. The robot 18 is responsible for transporting the wafer 200 from the cassette 14 to the temporary storage mechanism 19, and for transporting the wafer 200 from the cleaning unit 39 to the cassette 15. The robot 18 includes a robot hand 50 for suction and holding the wafer 200, a reciprocating mechanism 51 for moving the robot hand 50 back and forth horizontally, a reversing mechanism 52 for reversing the front and back of the robot hand 50 around a horizontal axis, and a lifting mechanism 53 for raising and lowering the robot hand 50 vertically. Details of the robot hand 50 will be described later.

[0032] The robot 18's forward / backward mechanism 51 is configured to allow a pair of arms to bend, with a reversing mechanism 52 connected to one end and a lifting mechanism 53 connected to the other end. The reversing mechanism 52 is connected to the base of the robot hand 50 via a joint 55. The reversing mechanism 52 rotates the robot hand 50 by driving, for example, a pulse motor (not shown) having a horizontal rotation axis, and by rotating 180 degrees, it can switch between a state where the front and back of the robot hand 50 are facing upward and a state where they are facing downward. The lifting mechanism 53 raises and lowers the robot hand 50 via the forward / backward mechanism 51 and the reversing mechanism 52 by driving, for example, a ball screw mechanism.

[0033] The grinding apparatus 1 is equipped with a control unit 57 that provides overall control of each part of the apparatus. The control unit 57 consists of a processor and memory that perform various processes. The control unit 57 provides overall control of each component of the grinding apparatus 1, including the robot 18, according to a control program stored in the memory.

[0034] Next, the robot hand 50 will be described with reference to Figures 3 and 4. Figure 3A is a schematic perspective view of the robot hand of the embodiment, and Figure 3B is a schematic perspective view of the robot hand of Figure 3A inverted. Figure 4A is a cross-sectional view of Figure 3A along line AA, and Figure 4B is a cross-sectional view of Figure 3B along line BB.

[0035] As shown in Figure 3A, the robot hand 50 comprises a hand body 61 formed in a generally circular disc shape and a support portion 62 disposed on the side (+Y side) of the hand body 61, and is provided in a shape referred to as a rice paddle shape. The support portion 62 is connected to the outer circumference of the hand body 61 and is formed to protrude laterally from the outer circumference. The support portion 62 then forms the base of the robot hand 50 and is attached to the joint 55 of the robot 18, and the hand body 61 is supported by the support portion 62. The support portion 62 has a pair of inclined edges 63 that extend in the tangential direction of the circular outer edge of the hand body 61 and gradually approach the joint 55 side, and is formed with a width that decreases as it moves away from the hand body 61.

[0036] Furthermore, the robot hand 50 includes a convex suction portion 65 provided on one side of the hand body 61 in the thickness direction, and a surface suction portion 66 provided on the other side. The convex suction portion 65 is provided on the upper surface of the hand body 61 in Figure 3A and the lower surface in Figure 3B, and the surface suction portion 66 is provided on the lower surface of the hand body 61 in Figure 3A and the upper surface in Figure 3B.

[0037] The convex suction section 65 includes a suction groove 68 corresponding to the ring-shaped convex portion 203 of the wafer 200, and a plurality of communication holes 69 communicating with the suction groove 68. The suction groove 68 is a continuous groove formed in an annular shape, and communication holes 69 are formed inside it at 90-degree intervals in the circumferential direction. The communication holes 69 communicate with a communication passage 71 (see Figures 4A and 4B) formed within the thickness of the hand body 61 and the support portion 62, and the suction groove 68 is connected to a suction source (not shown) via the communication passage 71 and the communication holes 69. By applying negative pressure from the suction source to the suction groove 68, the robot hand 50 sucks the convex portion 203 of the wafer 200 and holds the back surface 201 side of the wafer 200, as shown in Figure 4B.

[0038] On one surface of the hand body 61, which is provided with the convex suction portion 65, a circular recessed portion 72 is formed, having its outer edge slightly inward from the suction groove 68. The recessed portion 72 is formed to be recessed from the surface on which the suction groove 68 is formed.

[0039] In the grinding apparatus 1, as shown in Figure 4B, when the wafer 200 is transported by suction holding, one example is the transport (unloading) of the wafer 200 from the cleaning unit 39 to the cassette 15 after grinding and cleaning. In this transport, the control unit 57 controls the drive of the robot 18 so that the surface of the robot hand 50 with the convex suction part 65 is facing downwards. In this state, the suction groove 68 of the convex suction part 65 contacts the upper surface of the convex part 203 on the wafer 200, and the control unit 57 controls the convex suction part 65 to suck the convex part 203 of the wafer 200 by the action of negative pressure from the suction source. After this suction, the control unit 57 controls the drive of the robot 18 to transport the wafer 200, which is held by the convex suction part 65, from the cleaning unit 39 to the cassette 15 of the cassette stage 13.

[0040] The surface suction section 66 is provided with a plurality of suction holes 74 formed on the other surface of the flat hand body 61. The suction holes 74 are formed at four locations slightly inward from the outer circumference of the hand body 61, at 90-degree intervals in the circumferential direction of the hand body 61, and one location in the center of the hand body 61. The suction holes 74 are connected to a communication passage 75 (see Figures 4A and 4B) formed within the thickness of the hand body 61 and the support section 62, and each suction hole 74 is connected to a suction source (not shown) via the communication passage 75.

[0041] In the grinding apparatus 1, as shown in Figure 4A, when the wafer 200 is transported by suction holding, one example is the transport (loading) of the wafer 200 from the cassette 14 to the temporary storage mechanism 19 before grinding. In this transport, the control unit 57 controls the drive of the robot 18 so that the surface of the robot hand 50 with the surface suction unit 66 formed on it faces downward. In this state, the suction holes 74 of the surface suction unit 66 come into contact with the back surface 201 of the wafer 200 housed in the cassette 14, which does not form a protrusion 203, and the control unit 57 controls the surface suction unit 66 to suck the back surface 201 of the wafer 200 by the action of negative pressure from the suction source. After this suction, the control unit 57 controls the robot 18 to transport the wafer 200, which is held by the surface suction unit 66, from the cassette 14 to the temporary storage mechanism 19.

[0042] Here, the support portion 62, which is positioned on the side of the hand body 61, is also positioned on the side of the convex suction portion 65 and the surface suction portion 66. By supporting the hand body 61, the convex suction portion 65 and the surface suction portion 66 are also supported by the support portion 62.

[0043] As described above, according to this embodiment, a support portion 62 is arranged to the side of the convex suction portion 65 to form the robot hand 50. With this configuration, when transporting a wafer 200 having a ring-shaped convex portion 203, the robot 18 alone can perform the transport from when the robot hand 50 sucks and holds the wafer 200 to when it is stored in the cassette 15. This eliminates the need to lift the wafer from the spinner table with the holding pad of the transport means and then switch hands to hold the wafer with the robot hand, as in the conventional method, thereby shortening the transport time of the wafer 200.

[0044] Furthermore, in the robot hand 50, a convex suction section 65 is provided on one surface in the thickness direction of the plate-shaped hand body 61, and a surface suction section 66 is provided on the other surface. This allows for easy and quick switching between the convex suction section 65 and the surface suction section 66, which hold the wafer 200 by suction, by inverting the robot hand 50 with the inversion mechanism 52. For example, by holding the wafer 200 before grinding with the surface suction section 66, and holding the convex portion 203 of the wafer 200 after grinding and cleaning with the convex suction section 65, it is possible to prevent dust and other debris attached to the wafer 200 before grinding from adhering to the convex suction section 65. This prevents the convex portion 203 from becoming dirty after cleaning due to suction holding by the convex suction section 65.

[0045] Furthermore, the present invention is not limited to the embodiments described above, and can be implemented with various modifications. In the embodiments described above, the size, shape, etc., shown in the accompanying drawings are not limited thereto, and can be appropriately modified within the scope that allows the present invention to exert its effects. In addition, the present invention can be implemented with appropriate modifications as long as it does not deviate from the scope of its objectives.

[0046] For example, the convex suction section 65 may, in addition to suctioning and holding the convex portion 203 on the back surface 201 of the wafer 200, also suction and hold the back surface 201 before the convex portion 203 is formed, or suction and hold the front surface 204 side of the wafer 200. Furthermore, the surface suction section 66 may suction and hold not only the back surface 201 of the wafer 200, but also the front surface 204 side (the other side) of the wafer 200.

[0047] Furthermore, in the case of the robot hand 50, the configuration of the surface suction section 66 may be omitted, but providing the surface suction section 66 is advantageous because it allows the wafer 200 to be held by suction on both sides of the hand body 61. Moreover, the surface suction section 66 may be formed by increasing or decreasing the number of suction holes 74, forming suction grooves, or forming it from a porous material, as long as it is able to hold the wafer 200 by suction.

[0048] Furthermore, the formation of the recessed portion 72 in the convex suction portion 65 may be omitted, and the area excluding the suction groove 68 on one side of the hand body 61 may be made flat. However, forming the recessed portion 72 makes it easier to avoid unintended attraction between the hand body 61 and the wafer 200 due to static electricity.

[0049] Furthermore, although the robot hand 50 was applied to the grinding apparatus 1 in the above embodiment, it is not limited to this and may be applied to other processing apparatuses, such as a polishing apparatus for polishing a wafer 200. [Industrial applicability]

[0050] As described above, the present invention has the effect of shortening the transport time because, since the robot hand is configured with a support part arranged to the side of the convex suction part, a wafer having a ring-shaped convex part on the outside of the concave part can be transported by the robot alone. [Explanation of Symbols]

[0051] 1: Grinding equipment (processing equipment) 12: Cassette Stage 13: Cassette Stage 14: Cassette 15: Cassette 18: Robot 22: Chuck table 30: Processing unit 39: Cleaning unit 50: Robot hand 57: Control unit 62: Support part 65: Convex part suction part 66: Surface suction part 200: Wafer 201: Back surface (one side) 202: Concave part 203: Convex part 204: Front surface (the other side)

Claims

1. A robotic hand for suction and holding a wafer having a recess in the central part of one side and a ring-shaped protrusion outside the recess, A robot hand comprising a convex suction section that sucks up the convex portion on one side, and a support section disposed to the side of the convex suction section to support the convex suction section.

2. The robot hand according to claim 1, further comprising a surface suction unit on the other side of the wafer for suctioning the other side of the wafer or the one side of the wafer that does not have the protrusion.

3. A processing apparatus comprising: a robot equipped with a robot hand according to claim 1 or claim 2 and holding at least one side of a wafer; a chuck table for holding the other side of the wafer; a processing unit for forming a recess in the central part of the one side of the wafer and forming a ring-shaped protrusion outside the recess; a cleaning unit for holding the other side of the wafer and cleaning the one side; a cassette stage for placing a cassette for storing the wafer; and a control unit, The control unit is a processing apparatus that uses the protrusion suction unit of the robot hand to suck up the protrusions of the wafer and transports it from the cleaning unit to the cassette on the cassette stage.

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