JP4920547B2 - Wafer detection device and wafer transfer device - Google Patents

Description

  The present invention relates to a wafer detection device and a wafer transfer device.

  In semiconductor manufacturing, a dedicated robot is used to handle a disc-shaped wafer before dicing and transport it between devices or between a pod and a device. The robot has a wafer holder (hand) for steadily chucking and holding the wafer. The hand is required to be equipped with a wafer detection sensor in order to determine whether or not the wafer has been securely loaded.

  Currently, the specifications of the sensor are diverse, and besides the photoelectric type, there are a pressure type, a capacitance type, a mechanical type, and the like. However, regarding the sensor installation, it is common to arrange only the minimum parts in the hand part, the detection part and the amplifier part to be installed in the robot body part, and connect between them with an electric wire or air tube etc. .

  In recent years, thinning and back surface processing have been demanded for wafer processing, and as one of the functions of a transfer robot, a function of reversing a chucked wafer by 180 ° is required. When such a function is provided, the hand rotates 180 °, so that the wires connected to the sensor are twisted and entangled with the hand, or a load is repeatedly applied to the wires and the like, causing problems such as disconnection. The sensor malfunctions. Although it is possible to reduce the load and avoid problems by increasing the drawing radius of the wires, there is a demerit that the peripheral part of the hand is enlarged because a protective cover is required so as not to get caught in the peripheral equipment. Moreover, although the method of raising the flexibility of an electric wire etc. and improving durability is proposed, it cannot be said that it is a fundamental measure.

  2. Description of the Related Art Conventionally, in a substrate transport apparatus that holds a substrate with an arm that can be moved back and forth provided in the apparatus main body and transports the substrate, detection information of an optical sensor head provided in a jig supported by the arm The structure which transmits via the optical connector fixed to the main-body part and the optical connector provided in the jig | tool is disclosed (for example, refer patent document 1).

Further, in order to transport the substrate, it is mounted on a robot having at least two arms arranged on a machine base and connected by a rotating shaft so that the substrate transported by the robot can be detected. In addition, there has been proposed a photoconductive fiber that prevents torsion when an optical fiber wired in the robot is wired through the rotating shaft (see, for example, Patent Document 2). In Patent Document 2, as shown in FIG. 9, a photoconductive fiber 71 includes a light projecting fiber 72 and a light receiving fiber 73 disposed on the same axis, and two bodies at least at one intermediate position. Have been separated. One single photoconductive fiber 71A separated into two bodies is formed such that the projection fiber 72A protrudes from the end face of the light receiving fiber 73A at the separation position, and the single photoconductive fiber 71B of the other single photoconductive fiber 71B The surface facing the light projecting fiber 72A is drawn into the inside from the end surface of the other light receiving fiber 73B. The single photoconductive fiber 71A and the single photoconductive fiber 71B are connected in a non-contact state.
JP 2001-156153 A JP 2002-48936 A

  In the substrate transfer apparatus described in Patent Document 1, there is no description regarding the jig supported by the arm rotating 180 °. Further, in the configuration of Patent Document 2, since a light projecting optical fiber and a light receiving optical fiber are configured as coaxial fibers and used by being inserted into a rotation shaft, this configuration can be applied to a hand. The optical fiber can be prevented from being twisted. However, it is necessary for the hand to hold the wafer so that the wafer does not fall even if the hand is rotated so that the wafer mounting portion faces downward while holding the wafer. Adsorption is relatively simple for such holding, but a passage (pipe or tube) is required to apply negative pressure from the main body side to the hand in a state separated from the main body, and twisting of the pipe or tube is required. There is a need to prevent. Therefore, it is necessary to insert a pipe or tube through the rotation shaft that supports the hand, and the coaxial fiber cannot be inserted through the rotation shaft, and the coaxial fiber avoids the influence of the rotation of the rotation shaft. Can not. In addition, when a coaxial fiber is used, there is a problem that it is difficult to suppress loss in optical coupling between the hand side and the main body side.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to provide a wafer detection device provided on the hand in a wafer transfer apparatus configured to rotate the wafer transfer hand by 180 °. It is an object of the present invention to provide a wafer detection device capable of transmitting detection information to the main body without any trouble and a wafer transfer device including the wafer detection device.

  In order to achieve the above object, the invention described in claim 1 includes a hand including a mounting portion for mounting a wafer and a main body that supports the hand, and the hand faces the mounting portion of the wafer upward. Between the first state and the second state in which the wafer mounting portion faces downward, the wafer mounting portion being mounted on a wafer transfer device provided to be rotatable with respect to the main body. A wafer detection apparatus for detecting a wafer placed on the hand, wherein the hand includes a first optical fiber and a second optical fiber, the first end of the hand facing the body, and the hand. The second end portion is provided so as to emit light and receive reflected light on the wafer placed on the placement portion, and is disposed on the main body. The hand is arranged in the first state or the second state. In the state, a light projecting unit and a light receiving unit are disposed at positions facing the end surfaces of the first end portions of the first optical fiber and the second optical fiber, and the wafer is detected based on the amount of light received by the light receiving unit. A detection means is provided.

  According to this configuration, the first optical fiber and the second optical fiber provided in the hand are arranged at positions where the first end faces the main body at a symmetrical position with respect to the rotation axis of the hand. Even if the hand rotates (rotates), the light projecting unit and the light receiving unit on the main body side and the end portions of the first optical fiber and the second optical fiber are maintained facing each other, and transmission of light is not impaired. . Further, the optical fiber is not entangled even when the hand rotates, and the wafer is detected accurately both before and after the rotation.

  According to a second aspect of the invention, in the first aspect of the invention, the first optical fiber and the second optical fiber have incident light or outgoing light as parallel light at a tip on the first end side. A lens is attached, a lens that makes outgoing light parallel light is attached to the light projecting portion, and a lens that makes incident light parallel light is attached to the light receiving portion. According to this configuration, even if the accuracy of symmetry with respect to the rotation axes of the first optical fiber and the second optical fiber is somewhat poor, loss of light transmission between the main body side and the hand side can be reduced. .

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the hand is provided with wafer placement portions on both sides thereof, and the first optical fiber and the second optical fiber are provided with the first optical fiber and the second optical fiber. The two end portions are arranged symmetrically with respect to the hand, with respect to the rotation axis of the hand, so that the reflected light of the light emitted from one of the end portions to the wafer can enter the other end portion. ing. According to this configuration, even when the hand rotates 180 ° and the opposed state of the first optical fiber and the second optical fiber is reversed with respect to the light projecting unit and the light receiving unit of the main body, the first optical fiber and Since the second end portion of the second optical fiber is arranged symmetrically with respect to the rotation axis of the hand, the wafer detection is not adversely affected.

The invention according to claim 4 is the invention according to any one of claims 1 to 3,
The hand is rotatably supported by a bearing on the main body side, and is fixed to a distal end side of a rotating shaft that is rotated by a rotating means, and the wafer is attracted to the hand by the rotating shaft. A passage for applying a negative pressure of a negative pressure source provided in the main body to the suction portion provided for holding is formed. According to this configuration, it is easy to achieve both a configuration in which the hand sucks and holds the wafer and a configuration in which detection information by the optical fiber for wafer detection is transmitted to the main body without any trouble.

According to a fifth aspect of the present invention, there is provided a wafer transfer apparatus comprising the wafer detection sensor according to any one of the first to fourth aspects, wherein the position detecting means detects the rotational position of the hand. And the position of the hand detected by the position detection means is in a rotational position between the first state and the second state other than the state of either the first state or the second state. , Invalidating means for invalidating the detection result of the detecting means, and control means for permitting transfer of the wafer when the detecting means detects the wafer.

  According to this configuration, when the hand is rotating, that is, when the first optical fiber and the second optical fiber are not opposed to the light projecting unit and the light receiving unit on the main body side, the optical fiber on the hand side is projected on the main body side. Therefore, the wafer cannot be detected accurately. However, based on the detection signal of the position detection unit, the malfunction of the wafer transfer can be prevented by invalidating the detection result of the detection unit that detects the wafer while the hand is rotating.

  According to a sixth aspect of the present invention, in the fifth aspect of the present invention, a plurality of the hands are provided to be exchangeable with respect to the main body, and one of the hands is selected and used. Are provided with the first optical fiber and the second optical fiber constituting the wafer detection apparatus. According to this configuration, depending on the use of the wafer transfer apparatus, not only the same wafer can be held and transferred by the same method, but also different size wafers can be transferred or even the same size wafers can be held by different methods. Therefore, when an appropriate one is selected and used from a plurality of types of hands, the hand can be easily changed.

  According to the present invention, in the wafer transfer apparatus configured to rotate the wafer transfer hand by 180 °, the detection information of the wafer detection sensor provided in the hand can be transmitted to the main body without any trouble.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1A, a wafer transfer device 11 includes a main body 13 having a multi-joint arm 12 and a hand 14 that is supported by the multi-joint arm 12 and holds a wafer W (shown only in FIG. 6). And. The articulated arm 12 includes a first arm 16 that is rotatably supported by a lifting means (not shown) provided on the base 15, and a second arm 17 that is rotatably supported at the tip of the first arm 16. The third arm 18 is rotatably supported at the tip of the second arm 17 and is rotated in a horizontal plane by a motor (not shown).

  The hand 14 is formed in a substantially Y shape in a planar shape, and is provided with a mounting portion 19 for mounting the wafer W at the tip. In this embodiment, the mounting portion 19 is configured to contact the wafer W at the flat portion. The hand 14 is rotatable with respect to the third arm 18 between a first state in which the mounting unit 19 for the wafer W faces upward and a second state in which the mounting unit 19 for the wafer W faces downward. That is, it is provided so as to be rotatable with respect to the main body 13. The hand 14 is provided with a plurality of suction units 20 for holding the wafer W on the mounting unit 19. Each suction portion 20 is configured to be able to apply a negative pressure from the proximal end side of the hand 14 through a passage (not shown).

  As shown in FIG. 2, a rotating shaft 21 is rotatably supported by a bearing 22 on the third arm 18, and the proximal end side of the hand 14 is fixed to the distal end side of the rotating shaft 21. The rotation shaft 21 is formed with a passage 21 a that applies a negative pressure of a negative pressure source (not shown) provided in the main body 13 to the suction portion 20 provided in the hand 14. The rotating shaft 21 is communicated with a pipe 23 communicating with a negative pressure source via a seal ring 24. The seal ring 24 is made of, for example, polytetrafluoroethylene, and wear due to sliding with the rotating shaft 21 is suppressed.

  A bevel gear 25 is fixed to the rotating shaft 21 so as to be integrally rotatable. A hand rotating motor 26 is fixed to the outer surface of the upper wall of the third arm 18, and a bevel gear 27 meshing with the bevel gear 25 is fixed to the drive shaft 26 a protruding into the third arm 18 so as to be integrally rotatable. Has been. Then, the rotation shaft 21 is rotated together with the bevel gear 25 via the bevel gear 27 by the driving of the hand rotation motor 26. The hand rotating motor 26 and the bevel gears 25 and 27 constitute rotating means for rotating the rotating shaft 21.

  Next, the configuration of the wafer detection apparatus that detects the wafer W placed on the placement unit 19 will be described. The first optical fiber 28 and the second optical fiber 29 are arranged in the hand 14 at a position where the first end portion faces the main body 13, in this embodiment, the position opposite the tip of the third arm 18. Is provided. In addition, as shown in FIG. 3, the first end portions of the first optical fiber 28 and the second optical fiber 29 are provided so as to be arranged at symmetrical positions with respect to the rotation shaft 21. In this embodiment, the first end portions of both optical fibers 28 and 29 and the rotation shaft 21 are arranged on a plane parallel to the placement portion 19.

  At the tip of the main body 13, in this embodiment, the third arm 18, the first end of the first optical fiber 28 and the second optical fiber 29 in the state where the hand 14 is disposed in the first state or the second state. The light projecting unit 30 and the light receiving unit 31 are arranged at positions facing the end surface. In other words, the light projecting unit 30 and the light receiving unit 31 are arranged symmetrically with respect to the rotation shaft 21 on the horizontal plane including the rotation shaft 21.

  In the first optical fiber 28 and the second optical fiber 29, a lens 32 that converts incident light or outgoing light into parallel light is attached to the tip on the first end side. A lens 33 for light is attached, and a lens 34 for making incident light parallel light is attached to the light receiving unit 31.

  The first optical fiber 28 and the second optical fiber 29 are provided such that the second end portion can emit light and receive reflected light on the wafer W placed on the placement portion 19. In this embodiment, the second ends of both optical fibers 28 and 29 are connected to the sensor head main body 35. The sensor head main body 35 is configured in the same manner as that disclosed in Japanese Patent Application Laid-Open No. 2004-294291. As shown in FIGS. 4A and 4B, a pair of translucent members 36 for light projection and light reception are provided on the front end side of the sensor head main body 35. The translucent member 36 has a convex lens portion 36a, a reflecting surface 36b, and an opposing end surface 36c, and the opposing end surface 36c is connected to the second end surfaces of the first optical fiber 28 and the second optical fiber 29 as shown in FIG. It arrange | positions so that it may oppose. Light incident from the convex lens portion 36a is reflected by the reflecting surface 36b and emitted from the opposing end surface 36c, and light incident from the opposing end surface 36c is reflected by the reflecting surface 36b and emitted from the convex lens portion 36a.

  As shown in FIG. 4B, the two light transmitting members 36 are arranged in an inwardly inclined state so that the central axes of the respective convex lens portions 36a intersect each other at a predetermined position above the sensor head main body 35. Has been. The light emitted from the light transmitting member 36 on the light projecting side is reflected by the surface of the wafer W and enters the other light transmitting member 36.

    As shown in FIGS. 6A and 6B, the optical fiber 37 a continuous to the light projecting unit 30 and the optical fiber 37 b continuous to the light receiving unit 31 are connected to the detection control unit 38 provided in the third arm 18. It is connected. FIG. 6A is a schematic diagram showing the relationship between the first and second optical fibers 28 and 29 and the light projecting unit 30 and the light receiving unit 31 when the hand 14 is arranged in the first state. FIG. 6B is a schematic diagram when the hand 14 is arranged in the second state, and the rotation shaft 21 and the hand rotation motor 26 are omitted.

  As shown in FIG. 5, the detection control unit 38 includes a light projecting element (light emitting element) 39a that emits light to an optical fiber 37a, a light receiving element 39b that receives light emitted from the optical fiber 37b, and a light projecting element. An element driving circuit 40 and an amplifier circuit 41 that amplifies the detection signal of the light receiving element 39b are provided. For example, a light emitting diode (LED) is used as the light projecting element 39a, and a photodiode is used as the light receiving element 39b. The first optical fiber 28, the second optical fiber 29, the light projecting unit 30, the light receiving unit 31, the sensor head main body 35, the optical fibers 37 a and 37 b, and the detection control unit 38 constitute detection means for detecting the wafer W. .

  The main body 13 is provided with position detecting means 42 for detecting the rotational position of the hand 14. As shown in FIG. 2, the position detection unit 42 includes, for example, a reflective sensor 42 a provided at the tip of the third arm 18 and a reflective plate 42 b provided on the hand 14. One reflective sensor 42a is provided, and two reflective plates 42b are provided. The reflective plate 42b is provided at a position where one of the reflective plates 42b faces the reflective sensor 42a when the hand 14 is disposed in the first state or the second state.

  As shown in FIG. 5, the control device C that controls the articulated arm 12, the hand rotation motor 26, and the detection control unit 38 includes a CPU 43 and a memory 44, and includes a detection control unit 38 via an input / output interface (not shown). And the reflective sensor 42a. The CPU 43 determines that the wafer W is held on the mounting unit 19 when the output signal from the detection control unit 38 is equal to or higher than a predetermined level set in advance.

  Based on the detection signal of the reflective sensor 42a, the CPU 43 invalidates the detection result of the detection control unit 38 when the position of the hand 14 is other than the first state or the second state. That is, the CPU 43 serves as an invalidating unit that invalidates the detection result of the detecting unit when the position of the hand 14 is other than the first state or the second state based on the detection signal of the position detecting unit 42. Function. The CPU 43 functions as a control unit that permits transfer of the wafer W when the detection unit detects the wafer W.

  Further, the CPU 43 is not shown provided in the middle of the pipe 23 communicating with the arm driving means 45 for driving the hand rotation motor 26 and the articulated arm 12 and the negative pressure source via an input / output interface and a drive circuit (not shown). The solenoid valve is controlled. The CPU 43 controls the driving of the articulated arm 12 in a state where the wafer W is detected by the detecting means.

Next, the operation of the wafer transfer apparatus 11 configured as described above will be described.
For example, when the wafer transfer device 11 takes out the wafer W from the cassette and transfers it to the processing device, the control device C sets the wafer W in the first state, that is, with the placement unit 19 facing upward. After the articulated arm 12 is moved so as to be positioned below, the articulated arm 12 is raised. Further, the electromagnetic valve is driven to cause each suction portion 20 to generate a suction action. Thereafter, a command signal for performing wafer detection is output to the detection control unit 38. When receiving a command signal for wafer detection, the detection control unit 38 drives the light projecting element 39 a via the light projecting element driving circuit 40. The light emitted from the light projecting element 39a is emitted from the light projecting unit 30 to the first optical fiber 28 via the optical fiber 37a. The light emitted from the light projecting unit 30 enters the first end of the first optical fiber 28, is guided to the sensor head main body 35 by the first optical fiber 28, and is directed from one translucent member 36 toward the wafer W. Are emitted. The light emitted toward the wafer W is reflected by the wafer W and enters the other light transmissive member 36, passes through the second optical fiber 29, exits from the first end thereof, and enters the light receiving unit 31.

  The light incident on the light receiving unit 31 enters the light receiving element 39b through the optical fiber 37b. The light receiving element 39b outputs a voltage signal corresponding to the intensity of incident light to the amplifier circuit 41, and the amplifier circuit 41 amplifies the signal and outputs the amplified signal. The CPU 43 determines that the wafer W exists when the output signal of the amplifier circuit 41, that is, the output signal of the detection control unit 38 becomes equal to or higher than a set value. When the wafer W exists, the wafer W is transferred.

  The wafer transfer apparatus 11 may transfer the wafer W not only in the upward state, that is, in the first state, but also in the downward state, that is, in the second state. When the hand 14 is reversed, the hand rotating motor 26 is driven to rotate the rotating shaft 21 by 180 ° with the articulated arm 12 stopped. While the hand 14 is rotating, the first end portions of the first optical fiber 28 and the second optical fiber 29 do not face the light projecting unit 30 and the light receiving unit 31, so that the wafer W cannot be detected. Therefore, even if the output of the detection control unit 38 exceeds the set value, it is not a detection signal based on the light emitted from the second optical fiber 29. When the CPU 43 is in a state other than a state in which a detection signal indicating that the hand 14 is in the first state or the second state is output from the reflective sensor 42a, the CPU 43 invalidates the detection result of the detection control unit 38. During the rotation, the wafer transfer device 11 does not start transferring the wafer W.

  When the hand 14 is rotated from the state shown in FIG. 6A (first state) and rotated 180 ° to complete the reversal of the hand 14, the state shown in FIG. 6B (second state) is obtained. Become. In the second state, the first end of the first optical fiber 28 faces the light receiving unit 31, and the first end of the second optical fiber 29 faces the light projecting unit 30. The light emitted from the light projecting unit 30 enters the first end of the second optical fiber 29, is guided to the sensor head main body 35 by the second optical fiber 29, and is sent from the other light transmitting member 36 to the wafer W. It is emitted toward The light emitted toward the wafer W is reflected by the wafer W and enters one of the translucent members 36, passes through the first optical fiber 28, exits from the first end thereof, and enters the light receiving unit 31. Therefore, the wafer W is detected, and the CPU 43 allows the wafer transfer device 11 to transfer the wafer W and controls the articulated arm 12 to be driven. Then, the articulated arm 12 is driven and the wafer W is transferred to a predetermined position.

According to this embodiment, the following effects can be obtained.
(1) The wafer detection device is mounted on the wafer transfer device 11 which supports the main body 13 via the rotation shaft 21 so as to be rotatable, and is mounted on the mounting portion 19 on which the wafer W is mounted. The detected wafer W is detected. The hand 14 is provided with a first optical fiber 28 and a second optical fiber 29 so that the first end thereof is disposed at a position facing the main body 13 and symmetrical with respect to the rotation shaft 21. At the same time, the second end portion is provided so as to emit light and receive reflected light on the wafer W placed on the placement portion 19. In the main body 13, the light projecting unit 30 and the first optical fiber 28 and the second optical fiber 29 are opposed to the end surfaces of the first optical fiber 28 and the second optical fiber 29 when the hand 14 is disposed in the first state or the second state. The light receiving unit 31 is disposed and includes a detecting unit that detects the wafer W based on the amount of light received by the light receiving unit 31. Therefore, the first optical fiber 28 and the second optical fiber 29 provided in the hand 14 are the light projecting unit 30 and the light receiving unit 31 on the main body 13 side and the first optical fiber 28 even if the hand 14 rotates (rotates). And the end state of the second optical fiber 29 is kept opposite, and the transmission of light is not impaired. Further, even if the hand 14 is rotated, the optical fiber is not entangled, and the wafer W is accurately detected both before and after the rotation.

  (2) In the first optical fiber 28 and the second optical fiber 29, a lens 32 that makes incident light or outgoing light parallel light is attached to the tip on the first end side. A lens 33 that converts incident light into parallel light and a lens 34 that converts incident light into parallel light are respectively attached to the light receiving unit 31. Therefore, even if the accuracy of the symmetry of the first optical fiber 28 and the second optical fiber 29 with respect to the rotation shaft 21 is somewhat poor, loss of light transmission between the main body 13 side and the hand 14 side can be reduced. it can.

  (3) A configuration in which the wafer W is sucked and held is adopted as a configuration for holding the wafer W so that it does not fall even if the hand 14 rotates and the mounting portion 19 is reversed, and the suction portion 20 provided in the hand 14 is used. A passage 21 a for applying a negative pressure is formed in the rotation shaft 21. Therefore, the twist of the tube and pipe for negative pressure supply can be suppressed.

  (4) The hand 14 is rotatably supported by the bearing 22 on the main body 13 side, and is fixed to the distal end side of the rotating shaft 21 that is rotated by the rotating means. A passage 21 a is formed in which a negative pressure of a negative pressure source provided in the main body 13 is applied to the suction portion 20 provided to hold the wafer W by suction. Therefore, it is easy to achieve both a configuration in which the hand 14 sucks and holds the wafer W and a configuration in which detection information by the optical fiber for wafer detection is transmitted to the main body without any trouble.

  (5) The wafer transfer apparatus 11 includes a position detection unit 42 that detects the rotation position of the hand 14, and the position of the hand 14 detected by the position detection unit 42 is not in any of the first state and the second state. In this case, an invalidation unit that invalidates the detection result of the detection unit, and a control unit that permits transfer of the wafer W when the detection unit detects the wafer W are provided. Therefore, in a state where the detection of the wafer W cannot be performed accurately, the detection result of the detection unit that performs the wafer detection is invalidated, thereby preventing a malfunction of the wafer transfer.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIG. In this embodiment, the wafer transfer apparatus 11 includes a plurality of hands 14 that can be exchanged, and one of the hands 14 is selected and used, and the hand 14 is configured to be detachable. The point that 14 is attached to the rotating shaft 21 so as to be integrally rotatable is greatly different from that of the first embodiment. Since other configurations are the same as those of the first embodiment, different portions will be described. In addition, the same code | symbol is attached | subjected about the part similar to 1st Embodiment, and detailed description is abbreviate | omitted.

  FIG. 7B is a schematic cross-sectional view showing the relationship between the base end portion of the hand 14 and the rotation shaft 21, and FIG. 7A is a cross-sectional view taken along the line CC of FIG. 7B. A base end portion of the hand 14 is formed in a cylindrical shape, and an insertion hole 46 of the rotation shaft 21 is formed in the center portion. The insertion hole 46 has a large-diameter portion 46a and a small-diameter portion 46b. The large-diameter portion 46a is located on the proximal end side of the hand 14 and the small-diameter portion 46b is located on the back side. The large-diameter portion 46a and the small-diameter portion 46b are contracted. A pipe 47 is provided so as to continue through the diameter portion and communicate with the small diameter portion 46b. A seal ring 48 is disposed at the end of the pipe 47, and the rotating shaft 21 is inserted into the insertion hole 46 with the tip abutting against the seal ring 48. Grooves 49a and 49b communicating with the large-diameter portion 46a are formed radially at the base end portion of the hand 14 so that the circumferential interval is substantially the same, and one groove 49a is formed wider than the other two grooves 49b. Has been. In each of the grooves 49a and 49b, latching pieces 50a and 50b are rotatably supported in the grooves 49a and 49b via a shaft provided on the base end side. Each of the latching pieces 50a and 50b is provided with a slope that increases in distance from the center of the insertion hole 46 from the proximal end side toward the distal end side, and a latching portion 51 is formed at the distal end. Each of the latching pieces 50 a and 50 b is urged by a spring 53 having one end fixed to the inner surface of the ring member 52 so that the tip is directed toward the center of the insertion hole 46.

  The rotary shaft 21 is formed so that its outer diameter can be fitted into the small diameter portion 46b, and a locking portion 54 that abuts the latching pieces 50a, 50b is formed in a portion corresponding to the grooves 49a, 49b on the outer peripheral portion. In addition, a key portion 55 is formed on the side opposite to the locking portion 54 that contacts the hooking piece 50a. By engaging the key portion 55 of the rotating shaft 21 with the key groove 56 formed in the reduced diameter portion of the insertion hole 46, the hand 14 is reliably rotated integrally with the rotating shaft 21.

  In the hand 14 of this embodiment, as shown in FIG. 7A, the tip of the rotating shaft 21 is inserted into the insertion hole 46, and the three latching pieces 50 a and 50 b are interposed via the locking portion 54. The rotating shaft 21 is supported by the rotating shaft 21 in a state where the rotating shaft 21 is prevented from being detached. When the rotating shaft 21 is rotated, the hand 14 is rotated integrally with the rotating shaft 21. When the force acting on the hand 14 toward the tip side thereof, that is, the force acting in the right direction in FIG. 7A, is large enough to resist the biasing force of the spring 53, the latching pieces 50 a and 50 b are By rotating in a direction away from the locking portion 54, the locking state between the locking pieces 50 a and 50 b and the locking portion 54 is released, and the hand 14 is detached from the rotation shaft 21.

  When the hand 14 is attached to the rotating shaft 21, the center of the insertion hole 46 of the hand 14 and the center of the rotating shaft 21 are coaxial, and the key groove 56 and the key portion 55 correspond to each other. In this state, the hand 14 and the rotation shaft 21 are relatively moved to insert the rotation shaft 21 into the insertion hole 46. During the insertion, the locking portion 54 rotates by moving the latching pieces 50a and 50b, and when it further moves, the state shown in FIG. 7B is obtained.

Therefore, this embodiment has the following effects in addition to the same effects as the effects (1) to (5) in the first embodiment.
(6) A plurality of hands 14 are provided in the main body 13 of the wafer transfer device 11 so as to be replaceable, and one of the hands 14 is selected and used. According to this configuration, not only the same wafer W is held and transferred by the same method depending on the use of the wafer transfer apparatus 11, but also a wafer W having a different size or a different method for a wafer W having the same size. For example, when a proper hand is selected from a plurality of types of hands 14 and used, the hand 14 can be easily changed.

  (7) The hand 14 is provided with latching pieces 50a and 50b which are provided on the hand 14 side and are urged by the spring 53 and rotatable in the radial direction, and a locking portion 54 provided on the rotating shaft 21 side. A means for preventing the shaft from coming off from the rotation shaft 21 is configured. Therefore, it is possible to easily remove the force from the rotating shaft 21 by applying a force of a predetermined magnitude or more to the hand 14 in the axial direction of the rotating shaft 21 and in a direction away from the rotating shaft 21.

The embodiment is not limited to the above, and may be configured as follows, for example.
A placement unit 19 for the wafer W may be provided on both sides of the hand 14. In this case, it is preferable that both the first and second optical fibers 28 and 29 and the sensor head main body 35 can be shared regardless of the placement part where the wafer W is placed. As such a configuration, for example, there is a sensor head main body 35 shown in FIGS. In the sensor head main body 35, instead of the translucent member 36 of the first embodiment, a translucent member 57 in which a convex lens portion 36a and a reflective surface 36b are formed symmetrically with respect to a surface perpendicular to the opposing end surface 36c. Two are provided. The second end portions of the first optical fiber 28 and the second optical fiber 29 are symmetrical with respect to the rotation axis 21 with respect to the hand 14 and light emitted to the wafer W from either one end portion. The reflected light is arranged to be incident on the other end. According to this configuration, even when the hand 14 is rotated by 180 °, the opposed state of the first optical fiber 28 and the second optical fiber 29 with respect to the light projecting unit 30 and the light receiving unit 31 of the main body 13 is reversed. Since the second end portions of the first optical fiber 28 and the second optical fiber 29 are arranged symmetrically with respect to the rotating shaft 21 of the hand 14, the detection of the wafer W is not adversely affected.

  The configuration for holding the wafer W placed on the placement unit 19 of the hand 14 is not limited to the configuration for holding the wafer W by suction with a negative pressure suction action. For example, the wafer W may be attracted and held by electrostatic attraction, or the wafer W may be gripped and held by a gripping piece that can be moved between the gripping position and the release position. In the case where the suction holding is performed by electrostatic attraction, the power supply wiring for electrostatic attraction is guided from the passage 21a of the rotation shaft 21 to the hand 14 side, so that the hand 14 may be rotated by 180 °. There is no. When the wafer W is attracted and held by electrostatic attraction, the mounting portion 19 does not attract the wafer W by contacting the wafer W, but contacts and holds the wafer W by a plurality of protruding point contacts. In the configuration in which the wafer W is gripped and held by the gripping piece, the mounting unit 19 supports the wafer W in a surface contact state. For example, a plurality of gripping pieces are provided so as to be movable between a gripping position and a release position, and are biased to a gripping side or a releasing side by a spring, and negative pressure or compressed air is applied against the biasing force. A configuration in which the grip piece is operated and a configuration in which the grip piece is operated by an electromagnetic solenoid are employed.

  In the case where the placement units 19 are provided on both surfaces of the hand 14, if an adsorption method is used as a method for holding the wafer W, the wafer W is adsorbed by sucking air from the adsorption unit 20 on the side that does not adsorb the wafer W. Adsorption power on the side that is on the side is reduced. Therefore, as a method for holding the wafer W, suction holding by electrostatic chucking or gripping by a gripping piece is preferable.

  The wafer detection apparatus is not limited to detecting the wafer W placed on the placement unit 19 of the hand 14, but is used for a mapping operation performed to recognize the position of the wafer W stored in the cassette. You may apply to the sensor for mapping to be used. For example, in addition to the wafer detection sensor placed on the placement unit 19, a mapping sensor may be provided in the hand 14. The mapping sensor is provided at the tip of the hand 14 in order to emit light toward the peripheral surface of the wafer W and receive the reflected light. In this case, it is necessary to dispose two sets of optical fibers in the hand 14 and to provide two sets of light projecting units and light receiving units on the main body 13 side. By disposing one end portion at a symmetrical position with respect to the rotation shaft 21, even if the hand 14 is rotated 180 °, detection can be performed without any problem.

  When the first end portions of the first and second optical fibers 28 and 29 are arranged at symmetrical positions with respect to the rotation shaft 21, the first end portions and the rotation shaft 21 are placed on the placement surface (mounting portion). The first end portion is not limited to the arrangement located on the plane parallel to the rotation axis 21, and may be located on the plane orthogonal to the placement surface. May be.

  The first optical fiber 28 and the second optical fiber 29 are emitted to the wafer W through the sensor head main body 35 having the translucent member 36 having the convex lens portion 36a and the reflecting surface 36b, and the reflected light is received (incident). ). For example, without providing the sensor head main body 35, light is directly emitted from the end surfaces of the second end portions of the first and second optical fibers 28 and 29 to the wafer W to receive reflected light, or the second end. A convex lens may be attached to the part. The sensor system using the optical fiber is not limited to the reflection type, and may be a transmission type or a mirror reflection type. However, the transmission type and the mirror reflection type need to provide a light receiving part or a mirror on the opposite side of the light emitting part across the wafer, and the structure is complicated compared to the reflection type.

  ・ It is not limited to the detection of wafers W and wafer transfer devices, but to the detection and transfer devices of plate-like members such as thin glass plates and resin plates such as substrates of flat display panels such as liquid crystal panels, organic EL panels, and plasma display panels. You may apply.

The following technical idea (invention) can be understood from the embodiment.
-The board | substrate detection apparatus which detected the board | substrate of the flat display panel instead of the wafer in the invention as described in any one of Claims 1-4.

(A) is a schematic perspective view of a wafer conveyance apparatus, (b) is the elements on larger scale of (a). Sectional drawing which shows the relationship between the support state of a rotating shaft, and a hand base end. (A) is sectional drawing in the AA line of FIG. 2, (b) is sectional drawing in the BB line of FIG. (A) is sectional drawing which shows the relationship between a sensor head main body and an optical fiber, (b) is sectional drawing of the state which removed the upper case which shows the relationship between a pair of translucent member. The block diagram which shows the relationship between a control apparatus, a detection means, a position detection means, etc. FIG. (A) is a schematic diagram which shows the relationship between the light projection part and light-receiving part when the hand is in the first state, and the first and second optical fibers, and (b) is the same schematic diagram when the hand is in the second state. . The 2nd Embodiment is shown, (a) is CC sectional drawing of (b), (b) is a schematic sectional drawing which shows the relationship between the base end part of a hand, and a rotating shaft. The sensor head main body in another embodiment is shown, (a) is sectional drawing corresponding to Fig.4 (a), (b) is sectional drawing corresponding to FIG.4 (b). Sectional drawing of a prior art.

Explanation of symbols

  W ... wafer, 11 ... wafer transfer device, 13 ... main body, 14 ... hand, 19 ... mounting part, 20 ... adsorption part, 21 ... rotating shaft, 21a ... passage, 22 ... bearing, 28 ... first optical fiber, DESCRIPTION OF SYMBOLS 29 ... 2nd optical fiber, 30 ... Light projection part, 31 ... Light-receiving part, 32, 33, 34 ... Lens, 35 ... Sensor head main body which comprises a detection means, 37a, 37b ... Similarly optical fiber, 38 ... Similarly detection control Part, 42... Position detecting means.

Claims (6)

A hand having a mounting portion for mounting a wafer and a main body for supporting the hand, wherein the hand has a first state in which the wafer mounting portion faces upward, and the wafer mounting portion faces downward. A wafer detection device that is mounted on a wafer transfer device provided so as to be rotatable with respect to the main body between the second state and detects a wafer placed on the wafer placement portion. And
The hand is provided with a first optical fiber and a second optical fiber such that the first end of the hand is disposed at a position facing the main body and symmetrical with respect to the rotation axis of the hand. In addition, the second end portion is provided so as to emit light and receive reflected light on the wafer placed on the placement portion, and the hand is disposed in the first state or the second state on the main body. In this state, a light projecting part and a light receiving part are arranged at positions facing the end surfaces of the first end parts of the first optical fiber and the second optical fiber, and the wafer is detected based on the amount of light received by the light receiving part. A wafer detecting apparatus comprising a detecting means for performing.   In the first optical fiber and the second optical fiber, a lens that makes incident light or outgoing light parallel light is attached to the tip on the first end side, and the light emitted from the light projecting part is parallel light. The wafer detection apparatus according to claim 1, wherein a lens that makes incident light parallel light is attached to the light receiving unit.   Wafer mounting portions are provided on both sides of the hand, and the second end portions of the first optical fiber and the second optical fiber are symmetrical with respect to the rotation axis of the hand, 3. The wafer detection apparatus according to claim 1, wherein reflected light of light emitted from one of the end portions to the wafer is incident on the other end portion. 4.   The hand is rotatably supported by a bearing on the main body side, and is fixed to a distal end side of a rotating shaft that is rotated by a rotating means, and the wafer is attracted to the hand by the rotating shaft. 4. A passage for applying a negative pressure of a negative pressure source provided in the main body to an adsorbing portion provided for holding is formed. The wafer detection apparatus according to item. A wafer transfer device comprising the wafer detection device according to any one of claims 1 to 4,
Position detecting means for detecting the rotational position of the hand;
When the position of the hand is at a rotational position between the first state and the second state in a state other than either the first state or the second state based on the detection signal of the position detection means. And invalidating means for invalidating the detection result of the detecting means;
A wafer transfer apparatus comprising: control means for permitting transfer of the wafer when the detection means detects the wafer.   A plurality of hands are provided to be exchangeable with respect to the main body, and one of the hands is selected and used, and each of the hands includes the first optical fiber and the second optical fiber constituting the wafer detection apparatus. 6. The wafer transfer apparatus according to claim 5, wherein an optical fiber is provided.

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