Transfer vehicle

Abstract

To provide a transfer vehicle that can transfer a workpiece without damaging it.SOLUTION: A transfer vehicle 10 accommodates a wafer (workpiece) W on a carrier 41 and travels along a travel lane 50 arranged above processing apparatuses 100A, 100B, ..., causes the carrier 41, with a lifting mechanism 40, to pass and move up and down in the vertical direction through the opening 50a of the travel lane 50, and thereby delivers and receives a workpiece set WS to and from the processing apparatuses 100A, 100B. The carrier 41 comprises a holding mechanism 60 that holds the workpiece set WS. The holding mechanism 60 includes, for example, a vacuum pump 61, a battery 62, suction ports 63a, 63b that open in the holding surface 41b of the carrier 41, and a suction path 63 that communicates the suction ports 63a, 63b and the vacuum pump 61 with each other.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a transport vehicle that travels along a travel lane between a plurality of processing devices and transports a workpiece to each processing device.

Background Art

[0002] For example, a plurality of processing devices such as a grinding device for processing a wafer as a workpiece are installed in a clean room. A transport system has been proposed in which a transport vehicle (AGV: Automated Guided Vehicle) holding a wafer travels along a travel lane installed above the processing device to transport the wafer to each processing device (see, for example, Patent Documents 1 and 2).

[0003] By the way, in such a transport system, the transport vehicle accommodates the wafer, which is the workpiece, in the carrier. When the transport vehicle moves to a position above the processing device, the carrier is vertically passed through the opening of the travel lane by an elevating mechanism and lifted and lowered, so that the wafer is transferred to and received from the processing device. Here, in the processing device, the wafer is received from the carrier of the transport vehicle by a loading / unloading robot and loaded. After performing the required processing on this wafer, the wafer after the processing is completed is transferred to the carrier of the transport vehicle by the loading / unloading robot and accommodated in the carrier. Then, the carrier passes through the opening of the travel lane by the elevating mechanism and moves vertically upward, and the carrier is stored inside the transport vehicle. The transport vehicle storing the carrier travels on the travel lane toward the next processing device. Hereinafter, the same operation is repeated, the transport vehicle moves between the respective processing devices, transfers the wafer to each processing device, and receives the wafer after the processing from the processing device.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, wafer processing apparatuses include cutting apparatuses, laser processing apparatuses, polishing apparatuses, etc. Thin wafers processed by such processing apparatuses may warp after being separated from the chuck table of the processing apparatus. And, there is a possibility that problems such as cracking of the wafer and breakage of the wafer may occur while the warped wafer is being accommodated in a carrier and transported by a transport vehicle.

[0006] The present invention has been made in view of the above problems, and an object thereof is to provide a transport vehicle capable of transporting a workpiece without damaging it.

Means for Solving the Problems

[0007] The invention according to claim 1 for achieving the above object is a transport vehicle that accommodates a workpiece in a carrier, travels along a travel lane disposed above a processing apparatus, and transfers and receives the workpiece to and from the processing apparatus by passing the carrier vertically through an opening of the travel lane by means of a lifting mechanism, wherein the carrier is provided with a holding mechanism for holding the workpiece.

[0008] The invention according to claim 2 is the invention according to claim 1, wherein the holding mechanism includes a vacuum pump, a suction port that opens on a holding surface of the carrier, and a suction passage that communicates the suction port with the vacuum pump.

[0009] The invention according to claim 3 is the invention according to claim 2, wherein the holding mechanism includes a battery.

[0010] The invention according to claim 4 is the invention according to claim 1, wherein the holding mechanism includes a vacuum tank, a suction port that opens to the holding surface of the carrier, a suction passage that communicates the suction port with the vacuum tank, and a valve that opens and closes the suction passage.

[0011] The invention according to claim 5 is the invention according to claim 1, wherein the holding mechanism is a pressing mechanism that presses a workpiece against the holding surface of the carrier, and includes a pressing portion that presses the workpiece against the holding surface of the carrier, and a moving mechanism that moves the pressing portion in a direction perpendicular to the holding surface.

Advantages of the Invention

[0012] According to the invention described in claim 1, when the workpiece is accommodated in the carrier and moved along the running lane, or when the carrier is moved up and down by the lifting mechanism to pass through the opening of the running lane in the vertical direction to deliver and receive the workpiece to and from the processing device, the workpiece is held by the holding mechanism, so that damage due to warping of the workpiece is surely prevented.

[0013] According to the inventions described in claims 2 and 3, since the suction port that opens to the holding surface of the carrier and the vacuum pump are communicated by the suction passage, the suction port that opens to the holding surface of the carrier is sucked by the vacuum pump and a negative pressure is generated at the suction port. Therefore, the workpiece is sucked and held on the holding surface of the carrier by this negative pressure, and damage due to warping of the workpiece is surely prevented.

[0014] According to the invention described in claim 4, when the vacuum tank and the suction port that opens to the holding surface of the carrier are communicated by the valve, the suction port that opens to the holding surface of the carrier is sucked by the negative pressure of the vacuum tank, so that the workpiece is sucked and held on the holding surface of the carrier, and damage due to warping of the workpiece is surely prevented.

[0015] According to the invention described in claim 5, the pressing part of the pressing mechanism is pressed against the workpiece by the moving mechanism, and the workpiece is pressed against the holding surface of the carrier, so that breakage due to warping of the workpiece is surely prevented.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0017] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0018] <First Embodiment> As shown in FIGS. 1 and 2, the carrier vehicle 10 according to the first embodiment of the present invention holds a work set WS (see FIG. 5) including a wafer W which is a workpiece received from a loader / unloader device (not shown), and travels between the respective processing devices 100A, 100B... (see FIG. 1), thereby delivering or receiving the work set WS to / from the respective processing devices 100A, 100B... Note that the workpiece may be a wafer W with a tape attached to its lower surface, or a plate-shaped workpiece made of resin or the like.

[0019] Specifically, as shown in FIGS. 1 and 2, the carrier vehicle 10 travels along a travel lane 50 horizontally installed above the processing devices 100A, 100B... (only two are shown in FIG. 1). When the carrier vehicle 10 reaches a rectangular opening 50a that opens above each of the processing devices 100A, 100B... in the travel lane 50, as shown in FIG. 2, the elevator mechanism 40 passes the carrier 41 through the opening 50a of the travel lane 50 and lowers it vertically downward, and delivers the work set WS accommodated in the carrier 41 to the carrier stage 101 of the processing devices 100A, 100B... or receives the work set WS processed by the processing devices 100A, 100B... Then, the carrier 41 that has delivered the work set WS to the processing devices 100A, 100B... or received the work set WS from the processing devices 100A, 100B... rises vertically upward by the elevator mechanism 40, passes through the opening 50a of the travel lane 50, and is stored inside the carrier vehicle 10. Then, the carrier vehicle 10 moves along the travel lane 50 to the next processing devices 100B, 100C... and repeats the same operation hereinafter, thereby sequentially conveying the unprocessed or processed work set WS among the plurality of processing devices 100A, 100B...

[0020] Note that the wafer W conveyed by each transfer vehicle 10 is, for example, a thin disk-shaped member made of single-crystalline silicon (Si). As shown in FIG. 5, its surface (the upper surface in FIG. 5) is divided into a number of rectangular regions, and devices D such as ICs and LSIs are respectively formed in each rectangular region. Here, the wafer W is supported by the ring frame F by adhering the tape T attached to its back surface (the lower surface in FIG. 5) to the ring frame F, and the wafer W, the tape T, and the ring frame F are integrated as a work set WS.

[0021] (Configuration of the transfer vehicle) Here, the configuration of the transfer vehicle 10 according to the present invention will be described with reference to FIGS. 2 and 3. In the following description, as shown by the arrows in FIG. 3, the traveling direction of the transfer vehicle 10 is defined as the "front-rear" direction, and the vehicle width direction orthogonal to the traveling direction is defined as the "left-right" direction.

[0022] Each transfer vehicle 10 includes a chassis 11 composed of a polygonal metal plate and a vehicle body 10A having a double-layer structure of upper and lower parts composed of a polygonal resin substrate 12 disposed on the upper surface side of the chassis 11. The vehicle body 10A is supported by a pair of rotatable front wheels 13 disposed on the left and right of the front end portion and a pair of rotatable rear wheels 14 disposed on the left and right of the rear end portion so as to be able to travel in the arrow direction on the traveling lane 50 shown in FIG. 1. Here, the pair of left and right front wheels 13 function as drive wheels and steering wheels, and the pair of left and right rear wheels 14 are composed of casters that can freely rotate around a vertical axis.

[0023] And the pair of front wheels 13 disposed on the left and right of the front end portion of the chassis 11 are respectively supported by rotatable axles 15, and gear pulleys 16 (see FIG. 2) are respectively attached to the axles 15. Further, on the left and right of the lower surface of the rear end portion of the chassis 11, the left and right rear wheels (casters) 14 are respectively supported so as to be rotatable around a vertical axis (not shown).

[0024] Further, as shown in FIG. 3, on the vehicle body 10A (substrate 12) of the carrier vehicle 10, there are a drive unit 20 that independently rotationally drives a pair of left and right front wheels 13, a control unit 30, a receiving unit 31, and a transmitting unit 32 arranged on a rectangular plate-shaped support base 17. Between the support base 17 and the vehicle body 10A (substrate 12), a rectangular box-shaped carrier 41 that can be lifted is stored. The configurations of the lifting mechanism 40 and the carrier 41 will be described later.

[0025] In addition, first sensors (not shown) are respectively arranged at the front end and the rear end of the lower surface of the substrate 12, and second sensors (not shown) are respectively arranged on the left and right of the middle part in the front-rear direction of the lower surface of the substrate 12. These first sensors and second sensors optically detect the strip-shaped first mark M1 and second mark M2 laid on the upper surface of the traveling lane 50 shown in FIG. 4 in a non-contact manner. In this embodiment, they are constituted by reflection-type photosensors.

[0026] Furthermore, third sensors 18 for detecting collisions of the carrier vehicle 10 with obstacles are respectively arranged on the left and right of the front end and the rear end on the substrate 12. The third sensors 18 are electrically connected to the control unit 30, and touch sensors, proximity switches, etc. are used for the third sensors 18.

[0027] Here, the drive unit 20 shown in FIG. 3 that independently rotationally drives the left and right front wheels 13 includes a pair of left and right electric motors 21 as drive sources, a main battery 22 that supplies power to each electric motor 21, etc. As shown in FIG. 2, at the outer end of the output shaft (motor shaft) 21a of each electric motor 21, a gear pulley 23 having a smaller diameter than the gear pulley 16 is respectively connected. An endless timing belt 24 is respectively wound around these gear pulleys 23 and the gear pulley 16.

[0028] Therefore, when power is supplied from the main battery 22 to each electric motor 21 and both electric motors 21 are started, the small-diameter side gear pulleys 23 attached to the output shafts (motor shafts) 21a of the respective electric motors 21 are each rotationally driven. The rotation of each gear pulley 23 is decelerated (torque increased) via each timing belt 24 and transmitted to the large-diameter side gear pulleys 23 on the left and right, respectively. Then, each of the left and right gear pulleys 23 and each axle 15 rotate, and the front wheels 13 attached to each axle 15 are each independently rotationally driven. Therefore, due to the rotation of these front wheels 13, the transport vehicle 10 can travel in the direction of the arrow on the travel lane 50 shown in FIG. 1. Note that a lithium-ion battery or the like is used for the main battery 22. Each electric motor 21 is electrically connected to the control unit 30, and its drive is controlled by the control unit 30, respectively.

[0029] Note that the pair of left and right front wheels (drive wheels and steering wheels) 13 may be respectively attached to the output shafts 21a of the electric motors 21. Further, the drive wheels and the steering wheels may be arranged at the center in the front-rear direction of the transport vehicle 10, and the front wheels 13 may be casters that rotate freely like the rear wheels 14, and the vehicle may be configured with six wheels, or the front wheels and the rear wheels may be one wheel each. With this configuration, it is possible to change the direction of the transport vehicle 10 around its center.

[0030] Here, the control unit 30 provided in the transport vehicle 10 includes a CPU (Central Processing Unit) that performs arithmetic processing according to a control program, a storage unit such as a ROM (Read Only Memory) and a RAM (Random Access Memory), and the like. Then, the control unit 30 controls the drive of the drive unit 20 and the lifting mechanism 40 based on detection signals transmitted from a first sensor and a second sensor (not shown). The receiving unit 31 functions to receive a signal from the outside and transmit it to the control unit 30, and the transmitting unit 32 functions to transmit the signal received from the control unit 30 to the outside.

[0031] (Configuration of the lifting mechanism) Next, the configuration of the lifting mechanism 40 will be described with reference to FIG. 2. The lifting mechanism 40 includes a rotatable take-up shaft 42 disposed along the width direction at the upper part inside the carrier vehicle 10, and a motor 43 which is a drive source for rotating the take-up shaft 42 forward and backward. A small-diameter drive gear g1 coupled to the output shaft of the motor 43 meshes with a large-diameter driven gear g2 coupled to the take-up shaft 42. Four belts 44 (only two are shown in FIG. 2) are wound around the take-up shaft 42, and the lower ends of these belts 44 are respectively attached to the four corners of the upper surface of the carrier 41 as shown in FIG. 5.

[0032] Therefore, when the motor 43 is started, the rotation of its output shaft is decelerated (torque increased) through the meshing drive gear g1 and driven gear g2 and transmitted to the take-up shaft 42. Thus, the take-up shaft 42 rotates forward and backward, and the four belts 44 wound around the take-up shaft 42 are rewound or wound up. Here, when the four belts 44 are rewound from the take-up shaft 42, the carrier 41 attached to the lower ends of these belts 44 passes through the opening 50a formed in the traveling lane 50 and descends vertically. As shown in FIG. 2, for example, it reaches the carrier stage 101 of the processing device 100A and delivers the workpiece set WS stored inside to the processing device 100A. Also, as shown in FIG. 2, when the carrier 41 receives the processed workpiece set WS from the processing device 100A at the carrier stage 101 of the processing device 100A, the take-up shaft 42 of the lifting mechanism 40 rotates reversely, and the four belts 44 are wound around the take-up shaft 42. Therefore, the carrier 41 suspended by these belts 44 passes through the opening 50a formed in the traveling lane 50 and rises vertically upward and is stored inside the carrier vehicle 10. Then, the carrier vehicle 10 with the carrier 41 stored therein moves along the traveling lane 50 to the next processing device (for example, the processing device 100B shown in FIG. 1), and the same operation is repeated hereinafter.

[0033] (Configuration of the Traveling Lane) Next, the configuration of the travel lane 50 will be described with reference to FIG. 4. The upper surface of the travel lane 50 installed above each processing device 100A, 100B... has been subjected to a black matte finish by painting or surface treatment. And at the center in the width direction of the upper surface of the travel lane 50, a first mark M1 formed of a silver reflective tape or the like is laid along the travel direction of the carrier 10 (the vertical direction in FIG. 4).

[0034] Also, at the positions of the travel lane 50 above each processing device 100A, 100B..., delivery stations S1, S2... for delivering the work set WS to each processing device 100A, 100B... are formed, and rectangular openings 50a are respectively open in each delivery station S1, S2.... And on the upper surface of the travel lane 50, second marks M2 that cross the first mark M1 at right angles and lead to each delivery station S1, S2... are respectively laid. Here, each second mark M2 is formed of a silver reflective tape or the like.

[0035] (Configuration of the carrier) Next, the configuration of the carrier 41 will be described with reference to FIG. 5. Inside the carrier 41 in the form of a flat rectangular box, a rectangular three-dimensional storage space 41A for storing the work set WS is formed, and a rectangular entrance / exit 41a for taking the work set WS in and out of the storage space 41A in the direction of the illustrated arrow is open in this storage space 41A. Note that the work set WS is taken in and out of the storage space 41A of the carrier 41 by a loading / unloading robot (not shown) provided in the processing devices 100A, 100B....

[0036] (Configuration of the holding mechanism) Incidentally, the thin wafer W as the workpiece may warp, and as described above, there is a possibility that the wafer W may crack while being accommodated in the carrier 41 and conveyed by the transport vehicle 10. For this reason, the transport vehicle 10 according to the present embodiment is provided with a holding mechanism 60 for holding the wafer W during conveyance and preventing damage to the wafer W due to warping. Hereinafter, the configuration of this holding mechanism 60 will be described with reference to FIGS. 5 to 7.

[0037] The holding mechanism 60 is composed of an electric vacuum pump 61 housed inside the carrier 41, a flat rectangular solid battery 62 disposed on the upper surface of the carrier 41, an electromagnetic (solenoid type) switching valve V1 connected to a suction passage 63 extending from the vacuum pump 61, etc., and the battery 62 and the vacuum pump 61 are electrically connected. Therefore, the vacuum pump 61 is driven by the electric power supplied from the battery 62, but the battery 62 is connected to the main battery 22 via a connector 64 and is charged by the electric power supplied from the main battery 22. Note that the main battery 22 is charged by the electric power supplied from an external power source (not shown). Further, the connector 64 is composed of detachable two members 64a and 64b (see FIG. 6(b)).

[0038] Incidentally, a configuration without the battery 62 may be adopted. For example, when the carrier 41 is placed on the carrier stage 101, a connector may be connected so as to be able to drive the vacuum pump 61 and supply electric power to the vacuum pump 61. Also, when the carrier 41 is accommodated in the transport vehicle 10, a connector may be connected so as to be able to drive the vacuum pump 61 and supply electric power to the vacuum pump 61.

[0039] Incidentally, the bottom surface of the storage space 41A formed within the carrier 41 constitutes a holding surface 41b for holding the work set WS. As shown in FIG. 7, ring-shaped suction grooves 65 and 66 formed concentrically are formed on this holding surface 41b. One end of a suction path 63 extending from a vacuum pump 61 opens as circular suction ports 63a and 63b in these suction grooves 65 and 66, respectively. Therefore, by means of a switching valve V1, connection and disconnection between the vacuum pump 61 and the suction grooves 65 and 66 of the holding surface 41b of the storage space 41A are selectively made through the suction path 63.

[0040] (Function of the transport vehicle) Next, a method for transporting a work set WS, which is a workpiece to be processed, by the transport vehicle 10 configured as described above to processing apparatuses 100A, 100B,... will be described.

[0041] At the initial position P0 shown in FIG. 1, the transport vehicle 10 receives a pre-process (unprocessed) work set WS from a loader / unloader device (not shown) onto the carrier 41 (see FIG. 5). Then, the transport vehicle 10 moves in the direction of the arrow in FIG. 1 toward the processing apparatus 100A along the travel lane 50. Here, the transport vehicle 10 travels (self-propels) along the first mark M1 while optically and non-contactly detecting the first mark M1 of the travel lane 50 shown in FIG. 4 by means of first sensors (not shown) provided before and after it. That is, when the drive unit 20 shown in FIG. 3 is driven and controlled and the left and right electric motors 21 are activated to rotationally drive the front wheels 13, the transport vehicle 10 travels (self-propels) along the travel lane 50 along the first mark M1.

[0042] Therefore, the carrier 41 (see FIG. 5) that holds the unprocessed workpiece set WS is the transport vehicle 10 that travels from the initial position P0 shown in FIG. 1 toward the processing device 100A. When it is confirmed that the transport vehicle 10 has reached the first position P1 shown in FIG. 1 by the second sensors (not shown) arranged on the left and right of the transport vehicle 10 detecting the second mark M2 shown in FIG. 4 on the travel lane 50, the control unit 30 of the transport vehicle 10 stops the drive of the electric motor 21 of the drive unit 20 and stops the transport vehicle 10 at the first position P1 above the processing device 100A. Here, when the transport vehicle 10 is traveling along the travel lane 50 toward the first position P1, as shown in FIG. 6(a), the switching valve V1 of the holding mechanism 60 connects the vacuum pump 61 and the suction grooves 65, 66 (see FIG. 7) formed on the holding surface 41b of the carrier 41 via the suction path 63. When the vacuum pump 61 is driven by power supply from the battery 62, the ring-shaped suction grooves 65, 66 formed on the holding surface 41b of the storage space 41A in the carrier 41 are evacuated by the vacuum pump 61 through the suction path 63 from the suction ports 63a, 63b (see FIG. 7). For this reason, the workpiece set WS stored in the storage space 41A of the carrier 41 is sucked and held on the holding surface 41b of the storage space 41A, the warping of the wafer W is prevented, and the occurrence of the problem that the wafer W is damaged due to warping during transportation by the transport vehicle 10 is surely prevented.

[0043] As described above, when the carrier vehicle 10 stops at the first position P1, as shown by the dashed line in FIG. 4, the carrier vehicle 10 turns by an angle of 90°, the carrier vehicle 10 moves forward toward the transfer station S1, and the carrier vehicle 10 stops at a position where the carrier 41 (see FIG. 5) held by the carrier vehicle 10 aligns with the opening 50a of the travel lane 50. Then, from this state, the control unit 30 shown in FIGS. 1 and 3 drives and controls the lifting mechanism 40 shown in FIG. 2, and as shown in FIG. 2, the carrier 41 in which the workpiece set WS is stored is lowered through the opening 50a. In this way, even when the carrier 41 is descending, as shown in FIG. 6(b), since the switching valve V1 of the holding mechanism 60 connects the vacuum pump 61 and the suction grooves 65, 66 (see FIG. 7), the suction grooves 65, 66 are evacuated by the vacuum pump 61 through the suction path 63 from the suction ports 63a, 63b. For this reason, the workpiece set WS stored in the storage space 41A of the carrier 41 is suction-held on the holding surface 41b of the storage space 41A, the warping of the wafer W is prevented, and the occurrence of a problem that the wafer W is damaged due to warping during the descent of the carrier 41 is surely prevented.

[0044] Then, when the descending carrier 41 reaches the carrier stage 101 of the processing apparatus as shown in FIG. 6(c), the switching valve V1 operates to block the communication between the suction path 63 extending from the vacuum pump 61 and the suction grooves 65, 66 formed on the holding surface 41b of the storage space 41A of the carrier 41, and the suction grooves 65, 66 are opened to the atmosphere. As a result, the suction of the workpiece set WS by the suction grooves 65, 66 is released, and the workpiece set WS is transferred to the processing apparatus by a transfer robot (not shown).

[0045] Further, when the workpiece set WS processed in the processing apparatus is received by the carrier 41 and stored in the storage space 41A, the carrier 41 is lifted vertically upward by the elevating mechanism 40, passes through the opening 50a formed in the traveling lane 50, and is stored inside the transport vehicle 10. When the carrier 41 receives the workpiece set WS and is ascending in this way, the switching valve V1 connects the vacuum pump 61 and the suction grooves 65, 66 (see FIG. 7) formed on the holding surface 41b of the storage space 41A of the carrier 41 through the suction passage 63, and the suction grooves 65, 66 are evacuated by the vacuum pump 61. Therefore, the wafer W stored in the storage space 41A of the carrier 41 is suction-held on the holding surface 41b of the storage space 41A to prevent warping, and the occurrence of a problem that the wafer W is damaged due to warping during the ascent of the carrier 41 is surely prevented.

[0046] Thereafter, the transport vehicle 10 switches back from the position indicated by the chain line to the original position at the delivery station S1 shown in FIG. 4, then turns by 90°, and returns to the original state (the state shown by the solid line in FIG. 4). Then, the transport vehicle 10 travels (self-propels) along the first mark M1 shown in FIG. 1 toward the second position P2 shown in FIG. 1 while optically and non-contactly detecting the first mark M1 on the traveling lane 50 shown in FIG. 4 by a first sensor (not shown) provided before and after the transport vehicle 10. When the transport vehicle 10 reaches the second position P2, the transport vehicle 10 stops. At the delivery station S2 shown in FIG. 4, similarly to the above, the carrier 41 of the transport vehicle 10 descends to deliver the workpiece set WS to the next processing apparatus 100B, and the carrier 41 that has received the workpiece set WS processed in the processing apparatus 100B ascends and is stored inside the transport vehicle 10.

[0047] When the carrier vehicle 10 is moving from the first position P1 to the second position P2, and when the carrier 41 is descending and ascending, as described above, the workpiece set WS stored in the storage space 41A of the carrier 41 is suction-held on the holding surface 41b of the storage space 41A. Therefore, the occurrence of the problem that the wafer W is damaged due to warping is surely prevented. Hereinafter, the same operation is repeated, and while the carrier vehicle 10 travels between the next processing apparatuses 100C..., the workpiece set WS is delivered to or received from each processing apparatus 100C.... However, when the carrier vehicle 10 is traveling along the traveling lane 50, and when the carrier 41 is lowered to deliver the workpiece set WS to each processing apparatus 100C... and the workpiece set WS is received from each processing apparatus 100C... and ascending, the workpiece set WS is suction-held by the holding surface 41b of the storage space 41A of the carrier 41. Therefore, the damage to the wafer W due to warping is surely prevented.

[0048] Note that the configuration may not include the battery 62. In that case, the vacuum pump 61 may be driven when the carrier 41 is placed on the carrier stage 101 or when it is accommodated in the carrier vehicle 10.

[0049] <Second Embodiment> Next, a second embodiment of the present invention will be described with reference to FIG. 8. The basic configuration of the carrier vehicle 10' according to this embodiment is the same as that of the carrier vehicle 10 according to the first embodiment, and only the configuration of the holding mechanism for holding the workpiece set WS and preventing damage due to warping is different. Therefore, hereinafter, only the holding mechanism will be illustrated and described. Also, in FIG. 8, the same elements as those shown in FIG. 6 are denoted by the same reference numerals, and the repeated description thereof will be omitted hereinafter.

[0050] The holding mechanism 70 provided in the carrier vehicle 10' according to this embodiment is composed of a vacuum tank 71 housed inside the carrier 41, a suction source 72 provided inside the carrier vehicle 10, a suction passage 63 and an air discharge passage 73 extending from the vacuum tank 71, a check valve V2 connected to the end of the air discharge passage 73, and the like. Here, the suction source 72 and the vacuum tank 71 are connected by suction pipes 74 and 75, and both suction pipes 74 and 75 are detachable by a joint 76. And an electromagnetic (solenoid type) switching valve V3 is provided in one of the suction pipes 74, and a check valve V4 is provided at the end of the other suction pipe 75. Note that the check valves V2 and V4 prevent the inflow of air into the vacuum tank 71 while allowing the outflow of air from the vacuum tank 71.

[0051] Also, similar to the holding mechanism 60 provided in the carrier vehicle 10 of the first embodiment, ring-shaped suction grooves 65 and 66 (see FIG. 7) formed concentrically are formed on the holding surface 41b of the storage space 41A formed in the carrier 41. One end of the suction passage 63 extending from the vacuum tank 71 opens as circular suction ports 63a and 63b in these suction grooves 65 and 66 respectively (see FIG. 7).

[0052] Thus, when the carrier vehicle 10' is traveling along the travel lane 50 as shown in FIG. 8(a), the joint 76 is connected, and the switching valve V3 connects the suction source 72 and the vacuum tank 71 by the suction pipes 74 and 75. Therefore, air is sucked from the suction source 72 into the vacuum tank 71, and its internal pressure is maintained at a negative pressure of a predetermined pressure. Also, the inflow of air in the atmosphere into the vacuum tank 71 is blocked by the check valve V2.

[0053] When the transport vehicle 10’ is traveling along the travel lane 50 as shown in Fig. 8(a), the inner and outer double-ring-shaped suction grooves 65, 66 (see Fig. 7) formed on the holding surface 41b of the storage space 41A of the carrier 41 are vacuumed by the vacuum tank 71 through the suction ports 63a, 63b and the suction path 63. For this reason, the work set WS stored in the storage space 41A of the carrier 41 is suction-held on the holding surface 41b of the storage space 41A, the warping of the wafer W is prevented, and the occurrence of a problem that the wafer W is damaged due to warping during transportation by the transport vehicle 10’ is surely prevented.

[0054] Also, as shown in Fig. 8(b), when the transport vehicle 10’ stops and the carrier 41 is lowered or raised by the elevating mechanism 40, the connection of the joint 76 is disengaged and the connection of the suction pipes 74, 75 is released. At this time, due to the action of the check valve V2, the inflow of air in the atmosphere into the vacuum tank 71 is blocked, so the internal pressure of the vacuum tank 71 is maintained at a predetermined negative pressure. Therefore, since the inner and outer double suction grooves 65, 66 formed on the holding surface 41b of the storage space 41A of the carrier 41 are vacuumed by the vacuum tank 71 through the suction ports 63a, 63b (see Fig. 7) and the suction path 63, the work set WS stored in the storage space 41A of the carrier 41 is suction-held on the holding surface 41b of the storage space 41A, the warping of the wafer W is prevented, and the occurrence of a problem that the wafer W is damaged due to warping even during the elevation of the carrier 41 is surely prevented.

[0055] And, as shown in Fig. 8(c), in a state where the carrier 41 is placed on the carrier stage 101 of a processing apparatus (not shown) (the state of delivering and receiving the work set WS), the vacuum tank 71 is opened to the atmosphere by the switching valve V5 provided on the carrier stage 101 and the internal pressure of the vacuum tank 71 is maintained at atmospheric pressure. Therefore, the suction holding of the work set WS by the inner and outer double-ring-shaped suction grooves 65, 66 (see Fig. 7) formed on the holding surface 41b of the storage space 41A of the carrier 41 is released. For this reason, the work set WS can be easily taken in and out (delivered and received) with respect to the storage space 41A of the carrier 41.

[0056] Incidentally, as shown in FIG. 8(c), a suction source 77 is provided in the carrier stage 101 of the processing apparatus. This suction source 77 is connected to a check valve V2 via a suction passage 78, and a switching valve V5 is provided in the suction passage 78. Therefore, as described above, when the vacuum tank 71 is opened to the atmosphere by the switching valve V5 during the loading and unloading of the workpiece set WS with respect to the storage space 41A of the carrier 41, the suction holding of the workpiece set WS by the suction grooves 65 and 66 (see FIG. 7) formed on the holding surface 41b of the storage space 41A of the carrier 41 is released. Thus, when the carrier 41 receives the workpiece set WS from the processing apparatus into the storage space 41A, the switching valve V5 connects the suction source 77 and the vacuum tank 71 via the suction passage 78 and the air discharge passage 73. Then, since the air in the vacuum tank 71 is sucked by the suction source 77 via the air discharge passage 73, the check valve V2, and the suction passage 78, the internal pressure of the vacuum tank 71 is maintained at a negative pressure, and the suction grooves 65 and 66 (see FIG. 7) formed on the holding surface 41b of the storage space 41A of the carrier 41 are sucked by the negative pressure. For this reason, the workpiece set WS received from the processing apparatus and stored in the storage space 41A of the carrier 41 is sucked and held on the holding surface 41b of the storage space 41A, and breakage due to warping of the wafer W is reliably prevented.

[0057] Note that the vacuum tank 71 is not essential. In a configuration including the vacuum tank 71, a valve capable of opening to the atmosphere may be provided in the suction passage 63, and by opening and closing the valve V, the holding surface 41b and the vacuum tank 71 are communicated with each other to hold the wafer W on the holding surface 41b. On the other hand, the holding surface 41b may be opened to the atmosphere by operating the valve so that the wafer W can be taken out from the holding surface 41b.

[0058] Also, in the case of the configuration in which a valve is provided in the suction path 63 as described above, the vacuum tank 71 serves as the suction source, and in order to make the vacuum tank 71 have a negative pressure, the suction pipes 74 and 75 are provided, or a configuration including either one of the suction pipes 74 and 75 may be adopted. For example, in the configuration including only the suction pipe 74 and not including the suction pipe 75, the transport vehicle 10 does not include the suction source 72 and the valve V3. Then, as shown in FIG. 8(c), when the carrier 41 is placed on the carrier table 101 of the processing apparatus, the air discharge path 73 and the suction path 78 are communicated by the switching valve V5 to make the inside of the vacuum tank 71 have a negative pressure. Then, the carrier 41 separated from the carrier table 101 sucks and holds the wafer W on the holding surface 41b by the negative pressure of the vacuum tank 71 and maintains that state until it is transported to the next processing apparatus.

[0059] <Third Embodiment> Next, a third embodiment of the present invention will be described with reference to FIG. 9. The basic configuration of the transport vehicle 10” according to this embodiment is the same as that of the transport vehicle 10 according to the first embodiment, and only the configuration of the holding mechanism for holding the work set WS and preventing damage due to warping is different. Therefore, hereinafter, only the holding mechanism will be illustrated and described. Also, in FIG. 9, the same elements as those shown in FIG. 6 are denoted by the same reference numerals, and the repeated description thereof will be omitted hereinafter.

[0060] The holding mechanism 80 provided in the carrier vehicle 10 according to this embodiment is constituted by a pressing mechanism for pressing the work set WS stored in the storage space 41A of the carrier 41 against the holding surface 41b of the storage space 41A to prevent warping of the wafer W. Here, the pressing mechanism includes a plurality (for example, four) of pressing portions 81 provided inside the carrier 41, an air supply source 82 for supplying compressed air to these pressing portions 81, air supply paths 83, 84 and 85 extending from the air supply source 82 and connected to the respective pressing portions 81, and a check valve V6 connected to the end of the air supply path 85. Here, the air supply path 83 and the air supply paths 84, 85 can be disconnected and connected by a joint 86, and a switching valve V7 is provided in the air supply path 83. Further, a check valve V8 is provided in the joint 86. The check valve V6 prevents the outflow of air from the air supply path 85 into the atmosphere, and the check valve V8 prevents the inflow of air from the air supply paths 84, 85 into the air supply source 82.

[0061] Incidentally, the plurality (four in this embodiment) of pressing portions 81 are constituted by air cylinders each including a rod 81a that descends by compressed air, and in a state where no compressed air is supplied thereto, the rod 81a is positioned at the upper limit by a biasing means such as a spring (not shown). The pressing portion 81 may be constituted by an air bag and an air supply means for supplying air to the air bag to inflate the air bag.

[0062] When the transport vehicle 10” is traveling along the travel lane 50 as shown in Fig. 9(a), the joint 86 is connected, and the switching valve V7 connects the air supply source 82 and the plurality of pressing parts 81 through the air supply paths 83 and 84. Therefore, the rods 81a of the plurality of pressing parts 81 descend, and at least four equally spaced positions in the circumferential direction of the outer peripheral part of the wafer W of the work set WS stored in the storage space 41A of the carrier 41 and two symmetrical positions of the ring frame F are pressed to press the wafer W and the ring frame F against the holding surface 41b of the storage space 41A. For this reason, warping of the wafer W is prevented, and the occurrence of a defect that the wafer W is damaged due to warping during transportation by the transport vehicle 10” is surely prevented. Note that the pressing parts 81 are not limited to a plurality, and one pressing part may press the entire surface of the wafer W against the holding surface 41b. For example, an air bag may be provided above the holding surface 41b, and air may be supplied to the air bag to inflate it.

[0063] Also, as shown in Fig. 9(b), when the transport vehicle 10” stops and the carrier 41 is descending or ascending by the lifting mechanism 40, the connection of the joint 86 is disengaged and the connection between the air supply source 82 and the pressing part 81 is released. At this time, however, due to the action of the check valve V8, the outflow of the compressed air supplied to each pressing part and pressing the rod 81a against the work set WS from each pressing part 81 is prevented. Therefore, the work set WS stored in the storage space 41A of the carrier 41 continues to be pressed against the holding surface 41b of the storage space 41A by the rod 81a of the pressing part 81. For this reason, the occurrence of a defect that the wafer W is damaged due to warping even during the lifting and lowering of the carrier 41 is surely prevented.

[0064] Then, as shown in FIG. 8(c), in the state where the carrier 41 is placed on the carrier stage 101 of a processing apparatus (not shown) (the state of delivering and receiving the work set WS), the switching valve V9 provided on the carrier stage 101 opens each pressing portion 81 to the atmosphere, and the pressing force for pushing down the rod 81a of each pressing portion 81 is released. Then, the rod 81a of each pressing portion 81 moves upward by a biasing means (not shown) such as a spring and separates from the upper surface of the work set WS, so that the work set WS can be easily inserted into and removed from (delivered and received) the storage space 41A of the carrier 41. Note that each pressing portion 81 may be lifted and lowered only by compressed air without a biasing means. Further, each pressing portion 81 may use an electric cylinder that is lifted and lowered by electric power.

[0065] By the way, an air supply source 87 is provided on the carrier stage 101 of the processing apparatus. This air supply source 87 is connected to the check valve V6 via an air supply path 88, and a switching valve V9 is provided in the air supply path 88. Therefore, as described above, when each pressing portion 81 is opened to the atmosphere by the switching valve V9 when the work set WS is inserted into and removed from the storage space 41A of the carrier 41, the pressing of the work set WS by the rod 81a of each pressing portion 81 is released. Thus, when the carrier 41 receives the work set WS from the processing apparatus into the storage space 41A, the switching valve V9 connects the air supply source 87 and each pressing portion 81 via the air supply paths 88, 85, 84. Then, since compressed air is supplied from the air supply source 87 to each pressing portion 81, the rod 81a of each pressing portion 81 moves downward to press a plurality of locations of the work set WS in the storage space 41A of the carrier 41. For this reason, the work set WS received from the processing apparatus and stored in the storage space 41A of the carrier 41 is pressed against the holding surface 41b of the storage space 41A, and breakage due to warping of the wafer W is surely prevented.

[0066] Note that the air supply path 85 may be configured to include an air tank. When an air tank is provided, it may be configured to include either one of the check valves V8 and V6. That is, when the carrier 41 is placed on the carrier stage 101 or when it is housed in the transport vehicle 10, compressed air may be supplied to the air tank, and each pressing portion 81 may be driven using the compressed air.

[0067] In the above embodiments, the case where the transport vehicles 10, 10', 10" transport the workpiece set WS which is the workpiece to be processed has been described as an example. However, the workpiece to be processed transported by the transport vehicle according to the present invention may be any workpiece other than the workpiece set WS.

[0068] In addition, the present invention is not limited to being applied to the above-described embodiments, and it goes without saying that various modifications are possible within the scope of the technical idea described in the claims, the specification, and the drawings.

Explanation of Reference Numerals

[0069] 10, 10', 10": Transport vehicle, 10A: Vehicle body, 11: Chassis, 12:: Substrate 13: Front wheel, 14: Rear wheel, 15: Axle, 16: Gear pulley, 17: Support base 18: Third sensor, 20: Drive unit, 21: Electric motor, 21a: Output shaft (motor shaft), 22: Main battery, 23: Gear pulley, 24: Timing belt, 30: Control unit 31: Receiver, 32: Transmitter, 40: Lifting mechanism, 41: Carrier, 41A: Storage space 41a: Entrance / exit, 41b: Holding surface, 42: Take-up shaft, 43: Motor, 44: Belt 50: Travel lane, 50a: Opening, 60: Holding mechanism, 61: Vacuum pump 62: Battery, 63: Suction path, 63a, 63b: Suction ports, 64: Connector 64a, 64b: Connector members, 65, 66: Suction grooves, 70: Holding mechanism 71: Vacuum tank, 72: Suction source, 73: Air discharge path, 74, 75: Suction pipes 76: Joint, 77: Suction source, 78: Suction path, 80: Holding mechanism, 81: Pushing part 81a: Rod, 82: Air supply source, 83, 84, 85: Air supply paths, 86: Joint, 87: Air supply source, 88: Air supply path, 100A, 100B…: Processing devices 101: Carrier stage, D: Device, F: Ring frame, M1: First mark M2: Second mark, P0: Initial position, P1: First position, P2: Second position S1, S2: Transfer stations, T: Tape V1, V3, V5, V7, V9: Changeover valves, V2, V4, V6, V8: Check valves W: Wafer (workpiece), WS: Workset

Claims

1. A transport vehicle that accommodates a workpiece in a carrier, travels along a traveling lane disposed above a processing apparatus, and transfers and receives the workpiece to and from the processing apparatus by vertically moving the carrier through an opening of the traveling lane by means of a lifting mechanism, wherein the carrier is provided with a holding mechanism for holding the workpiece.

2. The transport vehicle according to claim 1, wherein the holding mechanism includes an electric pump, a suction port that opens on a holding surface of the carrier, and a suction passage that communicates the suction port with the electric pump.

3. The transport vehicle according to claim 2, wherein the holding mechanism includes a battery.

4. The transport vehicle according to claim 1, wherein the holding mechanism includes a vacuum tank, a suction port that opens on a holding surface of the carrier, a communication passage that communicates the suction port with the vacuum tank, and a valve that opens and closes the communication passage.

5. The transport vehicle according to claim 1, wherein the holding mechanism is a pressing mechanism that presses the workpiece against a holding surface of the carrier, and includes a pressing portion that presses the workpiece against the holding surface of the carrier and a moving mechanism that moves the pressing portion in a direction perpendicular to the holding surface.

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