JP2011125967A - Hand for wafer conveying robot, wafer conveying robot, and wafer conveying device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hand for conveying a wafer, reduced in size and weight, selecting the optimum sucking position free from causing a deflection and displacement of the wafer, and holding the wafer with different diameters so as to convey the wafer to a destination position, even with one hand. <P>SOLUTION: The hand for a wafer conveying robot is attached to an arm of the wafer conveying robot that conveys the wafers, and equipped with forks provided with vacuum sucking holes for sucking and holding the wafer. The forks are provided spinnably about the longitudinal direction of the forks. The upper surfaces constitute holding surfaces holding the wafer. Each holding surface is provided with the at least one vacuum sucking hole at a different position. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a hand for a wafer transfer robot, a wafer transfer robot, and a wafer transfer apparatus including the same.

  There is a wafer transfer apparatus (EFEM: Equipment Front End Module) that supplies a wafer to a host apparatus such as a semiconductor manufacturing apparatus or a semiconductor inspection apparatus or collects a wafer from the host apparatus. The wafer transfer apparatus is equipped with a wafer transfer robot, an aligner, and a controller that controls the wafer transfer robot and the aligner. The wafer transfer robot includes a hand for holding a wafer in order to transfer the wafer.

  In the wafer transfer apparatus, a wafer transfer robot takes out a wafer from a wafer closed container (FOUP: Front Opening Unified Pod) by hand and supplies it to the aligner. The aligner performs angle correction and horizontal position correction (eccentricity correction) of the V-notch or orientation flat of the wafer. The wafer is transferred to the host device after the angle correction and the position correction at the aligner are completed. The wafer transfer robot can also take out the processed wafer from the host manufacturing apparatus and store it in the FOUP.

  In order to prevent the wafer from being displaced when the wafer is placed, there are a method in which a vacuum suction unit is provided and the wafer back surface is sucked and held, and a method in which the wafer side surface is mechanically held to hold the wafer. In general, the hand that holds the backside of the wafer by suction uses a dedicated hand of a specific size for each wafer diameter, but in order to hold a wafer corresponding to different wafer diameters with one hand, To cope with this, the hand has a fork structure, and the fork is moved in parallel according to the wafer diameter (see, for example, Patent Document 1).

JP 2006-272526 A

  However, a hand equipped with the function of moving the fork in parallel to handle wafers with different diameters, the length of the traveling axis for moving the fork in parallel is the largest diameter width of the wafers being transferred. Since it is necessary to lengthen it according to the thing, the hand itself will be enlarged. A wafer transfer robot using such a hand has a large movable range in the wafer transfer apparatus, and thus the wafer transfer apparatus must be enlarged. In addition, the above-described hand also increases the mass of the hand, greatly affecting hand stop vibration and throughput.

  An object of the present invention is to solve the above-mentioned problems, and it is possible to configure a wafer transfer hand in a small size and light weight, and an optimal suction position that does not cause wafer deflection or misalignment with a single hand. And a wafer transfer robot using the same, and a wafer transfer apparatus including the same.

  In order to achieve the above object, a hand according to the present invention is a hand for a wafer transfer robot, which is attached to an arm of a wafer transfer robot for transferring a wafer and includes a fork provided with a vacuum suction hole for holding the wafer by suction. The fork is provided so as to be rotatable about the longitudinal direction of the fork as a rotation axis, the upper surface constitutes a holding surface for holding the wafer, and at least one vacuum suction hole is provided at a different position on each holding surface. It is characterized by being.

  A wafer transfer robot and a wafer transfer apparatus according to the present invention include the above-described hand.

  According to the present invention, the hand itself can be made compact and have a small mass, and wafers having different diameters can be held by one hand.

It is a perspective view which shows the structure of 1st embodiment of the hand for wafer conveyance robots which concerns on this invention. It is a partially transparent perspective view which shows the structure of a wafer conveyance apparatus. It is a top view of the fork of FIG. FIG. 4 is a cross-sectional view taken along line 4A-4A in FIG. 3. FIG. 2 is a plan view and a cross-sectional view of a state in which the hand of FIG. 1 holds a small-diameter wafer. FIG. 2 is a plan view and a cross-sectional view of a state in which the hand of FIG. 1 holds a large-diameter wafer. FIG. 2 is a diagram for explaining a relationship between an optimum position of a vacuum suction hole 3 and a wafer diameter in the hand of FIG. 1. The structure of 2nd embodiment of the hand for wafer conveyance robots which concerns on this invention is shown, and the top view and sectional drawing of the state holding the small diameter wafer are shown. It is the top view and sectional drawing of the state which hold | maintained the wafer of medium diameter. It is the top view and sectional drawing of the state which hold | maintained the large diameter wafer.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings.
[First embodiment]
First, a wafer transfer apparatus using a wafer transfer robot having a hand according to this embodiment will be described.

  FIG. 2 is a partially transparent perspective view showing the wafer transfer apparatus. As illustrated in FIG. 2, the wafer transfer apparatus 100 includes a housing 101, a FOUP 105 that is a sealed container that stores the wafer 50 supplied in the housing 101 in a clean state, and a load port 102 in which the FOUP 105 is installed. And a wafer transfer robot that transfers the wafer 50 between the semiconductor manufacturing apparatus or semiconductor manufacturing apparatus (hereinafter referred to as “higher level apparatus”) 108 that is provided in the housing 101 and is the transfer destination of the FOUP 105, aligner 103, and wafer 50. (Hereinafter simply referred to as “conveying robot”) 110. A fan filter unit 107 is provided in the upper part of the housing 101, and the fan filter unit 107 keeps the inside of the housing 101 in a clean environment by constantly sending clean air downward (inside the housing 101). The wafer transfer apparatus 100 includes a controller 104 that controls the transfer robot 110 and communicates with the host apparatus 108. The controller 104 has a calculation unit that performs valve switching control in accordance with the diameter of the wafer 50 held by the hand 1 to be described later, and detects a positional deviation amount of the wafer 50, presence / absence of the wafer 50, and abnormality of the wafer 50.

  A traveling rail 106 for reciprocating the transport robot 110 in one direction is provided in the housing 101, and the transport robot 110 is provided on the travel rail 106. The transfer robot 110 includes a base 111, an arm 112 provided on the base 111, and a hand 1 that is provided at the tip of the arm 112 and holds the wafer 50. The arm 112 can be swiveled by a swiveling shaft 113 and a driving means for rotating the swiveling shaft 113 provided in the base 111, and can be expanded and contracted by a driving means for rotating the arm shaft 114 and the arm shaft 114. It is.

  The aligner 103 detects the orientation of the wafer 50 (the position of the V notch or orientation flat) and the amount of eccentricity based on the light detected by the optical sensor while rotating the wafer 50, and corrects the orientation and position of the wafer 50. To do.

  The operation of the wafer transfer apparatus 100 will be described. In the wafer transfer apparatus 100, the transfer robot 110 takes out the wafer 50 from the FOUP 105 with the hand 1 and supplies it to the aligner 103. The aligner 103 performs V-notch or orientation flat angle correction (orientation correction) and horizontal correction (eccentricity correction) of the wafer 50. After the correction of the orientation and eccentricity of the wafer 50 is completed, the transfer robot 110 transfers the wafer 50 to the host device. The transfer robot 110 may take out the processed wafer 50 by the host device 108 and store it in the FOUP 105.

  FIG. 1 is a perspective view showing the configuration of the hand 1. As shown in FIG. 1, the hand 1 includes a pair of forks 2 (2 a and 2 b) that hold a wafer 50. The fork 2 is attached to the mechanism unit 10 for rotating the fork 2, and the mechanism unit 10 is attached to the tip of the arm 112 of the transfer robot 110. The fork 2 is a plate body having a thickness of about 2 to 3 mm mainly made of a material having a high longitudinal elastic modulus such as ceramics such as alumina or carbon fiber reinforced plastic (CFRP). The pair of forks 2 a and 2 b are arranged so as to be symmetrical with respect to the center line 1 a extending from the side attached to the arm 112 to the front end side of the hand 1.

  The fork 2 has a vacuum suction hole 3 for holding the wafer 50 placed on the hand 1 by vacuum suction on one surface (referred to as A surface) and the other surface (referred to as B surface) of the fork 2. It is provided on both surfaces and is installed in the mechanism unit 10 so as to be able to rotate about the shaft shaft 8 at the base of the fork 2 as a central axis. About the opening position of the vacuum suction hole 3, it arrange | positions in the mutually same position between one pair of forks 2a and 2b, and is arrange | positioned in the mutually different position in the A surface and B surface in one fork 2.

  The mechanism unit 10 is a drive source for rotating the fork 2. The motor 4 is mounted parallel to the fork 2, the motor pulley 7 is attached to the tip of the motor shaft, and the fork is attached to the shaft 8 of the fork 2. A pulley 6 and a belt 5 that transmits the rotation of the motor pulley 6 to the fork pulley 6 are provided. The mechanism unit 10 has a configuration in which two fork pulleys 6 are hooked on one motor pulley 7, and the left and right forks 2 a and 2 b can rotate in the same rotation direction and rotation angle by driving the motor 4. The upper surface of the fork 2 that can rotate by driving of the mechanism unit 10 serves as a holding surface for holding the wafer 50.

  The motor 4 used for the rotation of the fork 2 is equipped with a high-resolution encoder, and it is desirable that the error in the rotation angle be negligibly small. The two motors 2a and 2b are synchronized with the same angle by one motor 4. To make it work. As a drive source that constitutes the mechanism unit 10, in addition to the motor 4, other types such as a cylinder that operates with compressed air and a cylinder that operates with vacuum pressure can be used as long as the fork 2 is rotated to an arbitrary position. May be.

  The mechanism unit 10 is covered with a case 9 with the base of the fork as a boundary. The inside of the case 9 suppresses the dust generated from the driving unit 10 from flowing out to the outside of the case 9 (inside the wafer transfer device) by vacuum suction from the vacuum exhaust port 11 installed in the case 9, and is applied to the wafer 50. It prevents dust from adhering.

  3 is a plan view for explaining the inside of the fork 2, and FIG. 4 is a sectional view taken along line 4A-4A in FIG. However, in FIG. 4, the electromagnetic valve 14 connected to the vacuum suction hole 3 via the pipe 13 is shown as a block. As shown in FIGS. 3 and 4, the fork 2 has one vacuum suction hole 3 a that opens on one surface (A surface) of the fork 2 and two vacuum suctions that open on the other surface (B surface). Holes 3b and 3c are formed. Around the vacuum suction holes 3 a to 3 c, an annular convex portion 31 that comes into contact with the wafer 50 is provided. The two vacuum suction holes 3b and 3c that open to the same surface communicate with each other inside the fork 2, and the vacuum suction holes 3a and 3b (3c) that open to different surfaces do not communicate with each other. Are connected to the electromagnetic valve 14 to form independent vacuum paths. The pipe 13 is made of, for example, a rubber-like tube, passes through the arm 112 and the drive shaft 114 from the shaft 8, and is connected to the electromagnetic valve 14 of the vacuum device provided outside the transfer robot 110. The opening and closing of the electromagnetic valve 14 is controlled by the controller 104, and the vacuum suction and release of the wafer 50 are performed by opening and closing the electromagnetic valve 14. That is, the controller 104 and the electromagnetic valve 14 constitute vacuum path switching means for opening and closing the vacuum suction hole 3 on the holding surface (upper surface) side of the wafer 50. The vacuum path (the vacuum suction hole 3 and the pipe 14) is connected to a vacuum pressure sensor (not shown), and the controller 104 monitors the vacuum pressure sensor, whereby the wafer 50 is held on the hand 1. It is possible to determine whether or not it exists.

  5 and 6 are views showing a state in which the hand 1 holds wafers having different diameters in vacuum, FIG. 5 is a view showing a state in which a small-diameter wafer 50a is held in vacuum, and FIG. 6 is a large-diameter wafer. It is a figure which shows the state which hold | maintained 50c in vacuum.

  As shown in FIG. 5, the hand 1 holds a wafer 50 b having a small diameter (for example, a diameter of 200 mm) when the A surface where one vacuum suction hole 3 a opens in one fork 2 is the upper surface. Since the vacuum suction hole 3 is installed on the fork A surface at an optimum position for holding the small-diameter wafer 50a, it is possible to hold the small-diameter wafer 50a with high reliability. The position of the vacuum suction hole 3 optimal for holding the wafer 50 is a position where the wafer 50 is not bent and misalignment is unlikely to occur. Specifically, the wafer 50 is held so that the tip of the fork 2 is positioned in a semicircular region ahead of the center (center line 1 b) in the direction perpendicular to the fork 2. This is a position to prevent the wafer from being bent due to the weight of the front side region and the wafer from being displaced due to the weight greater than the vacuum suction force.

  When a command to transfer a large-diameter wafer 50c (for example, 450 mm in diameter) different from the small-diameter wafer 50a is executed by the host device 108 or the user's operation, the controller 104 issues a command to the motor 4, and the motor 4 The fork 2 rotates 180 degrees by being driven to rotate, and the B surface of the fork 2 becomes a holding surface for sucking and holding the wafer.

  As shown in FIG. 6, two vacuum suction holes 3b and 3c are opened on the B surface of one fork 2, and these vacuum suction holes 3b and 3c are for holding a large-diameter wafer 50c. Since the vacuum suction holes 3b and 3c are arranged at the optimum positions, the large-diameter wafer 50c with high reliability can be held.

  FIG. 7 is a diagram illustrating a state where a small-diameter wafer 50a is held on the fork B surface. As shown in FIG. 7, as shown in FIG. 7, when the small-diameter wafer 50a is held on the fork B surface (the positions of the vacuum suction holes 3b and 3c are for the large-diameter wafer 50c), the vacuum suction hole 3c becomes a small diameter. The wafer 50a is out of the outer shape, the vacuum pressure does not increase, and the small diameter wafer 50a cannot be sucked and held.

  Conversely, if the large-diameter wafer 50c is held on the fork A surface (the position of the vacuum suction hole is for the small-diameter wafer 50a), the small-diameter wafer 50a can be held. During operation, the base side of the hand 1 of the large-diameter wafer 50c bends, and the large-diameter wafer 50c and the mechanism unit 10 come into contact with each other, causing dust. Although it is possible to limit the operation speed of the wafer transfer robot 110 so as to minimize the deflection, it greatly affects the throughput.

  That is, the vacuum suction hole optimal for holding the small-diameter wafer 50a is provided on the fork A surface, and the vacuum suction hole 3 optimal for holding the large-diameter wafer 50c is provided on the fork B surface. By selecting the holding surface of the fork 2 and rotating the fork 2 by the mechanism unit 10 to hold the wafer 50 on the optimal holding surface, the wafer can be transported with high reliability without reducing the throughput.

  As for the vacuum suction holes 3b and 3c opened on the B surface of the fork 2, when the vacuum suction hole 3b is used for wafer suction and the vacuum suction hole 3c is used only for supporting and holding the wafer, as shown in FIG. In a state where the B surface (position for the large diameter wafer 50c) is the upper surface, both the small diameter wafer 50a and the large diameter wafer 50c can be held. However, in this case, it is necessary that the vacuum suction hole 3b and the vacuum suction hole 3c be connected to the electromagnetic valve 14 through a mutually independent vacuum path.

  Operations of the transfer robot 110 including the hand 1 and the wafer transfer apparatus 100 will be described. When the wafer size switching command is executed by the host apparatus 108 or user operation, the controller 104 determines whether the wafer 50 is placed on the upper surface of the fork 2 of the hand 1 of the wafer transfer robot 110 when the command is executed. judge. The wafer 50 placement determination method determines whether or not the wafer 50 is present by sucking the vacuum suction hole 3 on the upper surface of the fork 2 while the wafer transfer robot 110 is stopped.

  When the controller 104 determines that the wafer 50 is present on the upper surface of the fork 2, it continues the transfer sequence of the mounted wafer 50 and waits until it is stored in the FOUP 105 or forcibly stores the FOUP 105. 2 allows the user to select an instruction on what to do with the wafer 50 on top. If it is determined that there is no wafer 50, the controller 104 collects current position information such as the position of the arm 112 of the transfer robot 110, and the transfer robot 110 is moved to a safe place where interference does not occur even if the fork 2 of the hand 1 is rotated. Determine if is located. When it is determined that the transfer robot 110 is in a dangerous position (a position where the fork 2 interferes), the hand 1 is retracted to the safe position. If it is determined that the fork 2 is in a safe position where the fork 2 can rotate, the controller 104 issues a drive command to the motor 4 of the mechanism unit 10 to rotate the fork 2 to an arbitrary position according to the diameter of the wafer 50. The designated wafer 50 can be transferred.

  According to the hand of the present embodiment, the hand 1 is reduced in size by having a configuration in which the position of the vacuum suction hole 3 on the holding surface is changed by the rotation of the fork 2 without changing the distance between the pair of forks 2. It is possible to hold a wafer having a small diameter and having a different diameter without bending or causing a positional shift, and realizing a highly reliable wafer transfer without reducing the throughput.

In the present embodiment, the mechanism 10 that rotates the fork 2 is housed in the case 9, so that there is a possibility that the mechanism 4 may be generated due to friction of the motor 4, the belt 5, the fork pulley 6, and the shaft 8. A certain amount of dust or dust can be retained in the case 9 to prevent generation of dust due to contact other than the suction surface of the hand 1 and the wafer 50, or to prevent the wafer 50 from dropping or breaking due to insufficient suction power of the wafer 50.
[Second Embodiment]
A second embodiment of the present invention will be described with reference to FIGS. The basic components of the wafer transfer robot hand 81 of the present embodiment are substantially the same as those of the hand 1 of FIG. 1 described above, but a fork 82 is formed in a substantially triangular prism shape, and vacuum suction is opened on each side surface. The difference is that a hole is provided.

  8 to 10 are a top view and a cross-sectional view of the hand 81 according to the present embodiment. In particular, FIG. 8 is a view when holding a small-diameter wafer 50a, and FIG. 9 is a view showing holding a medium-diameter wafer 50b. FIG. 10 is a view when a large-diameter wafer 50c is held.

  As shown in FIGS. 8 to 10, in this embodiment, the fork 82 is formed in a substantially triangular prism shape (the cross section is a regular triangle), and vacuum suction holes for holding the wafer 50 by vacuum suction are provided on the respective side surfaces. 3 is provided. If one fork 82 has three side surfaces as a C surface, a D surface, and an E surface, one vacuum suction hole 3d is formed on the C surface, and two vacuum suction holes 3e and 3f are formed on the D surface. The two vacuum suction holes 3g and 3h are formed on the E surface and are arranged differently from the D surface. Further, the vacuum suction holes 3d to 3h opened on the respective side surfaces constitute independent vacuum paths for the respective side surfaces, and are arranged at positions optimal for the diameter of the wafer 50 to be held. The pair of forks 82, 82 have the same configuration, and when the forks 82, 82 are rotated by the rotation of the motor 4, the surfaces on which the same vacuum suction holes 3 are arranged are the upper surfaces.

  With this configuration, the small-diameter wafer 50a can be optimally held when the C surface of the fork 82 is on the upper surface as shown in FIG. 8, and when the D surface of the fork 82 is on the upper surface as shown in FIG. The wafer 50b can be held optimally, and the large-diameter wafer 50c can be optimally held when the E surface of the fork 82 is on the upper surface as shown in FIG.

  Further, with respect to the thickness of the fork 82, since the plurality of wafers 50 are held in the FOUP 105 with a predetermined interval (for example, about 9 mm), the fork 82 is thick enough to be inserted into the gap between the wafers 50. As a result, it is sufficiently narrower than the distance between the wafers.

  Also in the hand 81, as in the case of the hand 1, when a command for transporting wafers of different sizes is executed by the host device 108 or a user operation, a command is given from the controller 104 to the motor 4 of the hand 81 and transported. The motor 4 is driven so that the surface optimal for the wafer diameter becomes the upper surface (holding surface), and the fork 2 is rotated by 60 degrees or 120 degrees, thereby holding the wafer 50 without bending or causing a positional shift. be able to.

  Although the wafer transfer robot hand has been described above, the transfer target can be applied not only to a wafer but also to a transfer robot hand that transfers a glass substrate, a thin plate, or the like. Further, in the above-described embodiment, the hand capable of sucking and holding the wafers 50 of two kinds and three kinds of diameters has been described. It is possible to cope with four or more types of wafers having different diameters.

DESCRIPTION OF SYMBOLS 1 Hand 2 Fork 3 Vacuum suction hole 4 Motor 5 Belt 10 Mechanism part 50 Wafer 100 Wafer transfer apparatus 104 Controller 110 Wafer transfer robot

Claims (7)

In a hand for a wafer transfer robot, which is attached to an arm of a wafer transfer robot for transferring a wafer and includes a fork provided with a vacuum suction hole for holding the wafer by suction,
The fork is provided so as to be able to rotate about the longitudinal direction of the fork as a rotation axis, the upper surface constitutes a holding surface for holding the wafer, and each holding surface is provided with at least one vacuum suction hole at different positions. A hand for a wafer transfer robot.   The hand for a wafer transfer robot according to claim 1, wherein the fork is formed in a prismatic shape or a plate shape, and at least one vacuum suction hole is provided on each side surface of the prismatic body and on both surfaces of the plate. A hand for a wafer transfer robot.   The hand for a wafer transfer robot according to claim 1 or 2, further comprising a mechanism for rotating the fork, the mechanism including a motor and a belt for transmitting rotation of the motor to the fork. A hand for a wafer transfer robot.   4. A hand for a wafer transfer robot according to claim 3, wherein the mechanism is housed in a case that blocks the mechanism from the wafer.   5. The wafer transfer robot hand according to claim 1, wherein the vacuum suction holes opened to different surfaces are formed in the fork without communicating with each other, and each has a different vacuum path. A hand for a wafer transfer robot, characterized in that the hand is connected to a vacuum path switching means for switching a vacuum path.   6. A wafer transfer robot comprising a base, a pivotable and extendable arm provided on the base, and a hand for holding a wafer provided at a tip of the arm. A wafer transfer robot comprising the described hand.   A case attached to the transfer destination or transfer source of the wafer, a container provided in the case for storing the wafer, a wafer in the container being supplied to the transfer destination, or the wafer at the transfer source being collected in the container 7. A wafer transfer apparatus comprising a wafer transfer robot and an aligner for correcting the position and orientation of the transferred wafer.

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