JPH04343448A - Wafer grasping device - Google Patents

Abstract

PURPOSE:To realize a wafer grasping device which can effectively grasp a wafer by a predetermined grasping force with higher positional accuracy than that of prior art and make possible to automate both-side surface soldering steps of the wafer as desired, in the device provided at an end of an arm of a robot, etc., to hold it at the end face of the wafer. CONSTITUTION:First and second movable fingers 32, 37 in which pawls in contact with an end face of a wafer 1 (e.g. rotary rollers provided at the side with a V-shaped groove in contact with the wafer) are rotatably provided at the end, and the first movable finger 32 driving mechanism for pressing the end face of the wafer by the pawls of the finger 32 to move it in the longitudinal direction to bring the end face of the wafer into contact with the pawls of the second movable fingers 37, 38 and holding the wafer 1 between at least three or more pawls of the first and second movable fingers, are provided.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a wafer gripping device that is attached to the tip of an arm of a robot, etc.
In particular, the present invention relates to a gripping device that can grip the end face of a semiconductor wafer with good positional accuracy and maintain reliable retention in the gripped state.

0002

2. Description of the Related Art A first conventional example of a device for gripping a wafer of a semiconductor device is shown in FIG. The apparatus shown in the figure includes a suction part 8 having a vacuum hole 5a for vacuum suctioning a wafer 1, a base body 9 connected to this suction part 8, and a base body 9 connected to a vacuum pump and connected to the suction part 8 through the base body 9. It is composed of a vacuum hose 5b. The gripping of the wafer 1 by this conventional device is as shown in FIG.
is placed on the surface of the suction unit 8, and vacuum suction is performed. Further, when the sucked wafer 1 is removed from the sucking section 8, the vacuum is returned to normal pressure.

The gripping device shown in FIG. 10 has a simple structure and is inexpensive, but there are many problems in gripping reliability. For example, Figure 1
1, it is strong against the tensile force T perpendicular to the suction surface of the wafer 1, but very weak against the force S parallel to the suction surface, which may cause the wafer to fall. . Furthermore, this gripping method has the problem that the wafer cannot be gripped accurately because an error occurs between the preset suction position on the wafer and the actual suction position on the wafer.

A second conventional example of a device for gripping a semiconductor wafer is shown in FIG. This device has a base body consisting of a bottom plate, a pair of end plates 2 and 3 erected on both ends of the bottom plate, and a cover 4, and a mechanical part is provided inside the base body. That is, a pair of guide shafts 6 and 7 are attached to a pair of end plates 2 and 3 in parallel with each other, and a pair of movable bodies 10 and 11 are supported by the guide shafts 6 and 7 in a sliding manner and being attracted to each other by elastic bodies. . A movable finger 12 is attached to the upper center of one of the pair of movable bodies 10 and 11, that is, in this example, the movable body 10 is disposed on one end side of the base. The movable finger 12 extends forward through the end plate 2 at one end of the base, and a support claw 14 for gripping the wafer 1 is attached to the tip thereof. Further, the base end of the movable finger 12 is connected to the movable body 11.
It is inserted into the groove formed in the. Also, this movable body 1
A rack 19 is attached to the rack 1, and a pinion 20 that meshes with the rack 19 is attached to the output shaft of a motor fixed to the bottom plate. Further, fixed fingers 17 and 18 are attached to the outer end of one end plate 2 of the base body, and support claws 15 and 16 similar to the support claw 14 attached to the movable finger 12 are provided at the tip of each of the fixed fingers 17 and 18. It will be done.

The conventional device shown in this figure grips a wafer by moving the wafer 1 (indicated by a dashed line) inserted between the supporting claws 14, 15, and 16 by operating a mechanism provided in the base body. By doing so, the movable finger 12 is slid,
This is done by gripping between the movable finger 12 and fixed fingers 17 and 18. Note that releasing the gripped wafer is the opposite of the above-mentioned gripping operation, and is performed in the reverse order of the above-mentioned operation.

The gripping device shown in FIG. 12 can grip a wafer more accurately and reliably than the first prior art gripping device using vacuum suction. However, when an external force is temporarily applied in the direction opposite to the direction of movement of the movable fingers 12 when gripping a wafer, for example, when a wafer stuck on a certain surface is peeled off by the movable fingers 12, or when the wafer is slipped When the frictional force of the surface changes rapidly, as when moving by hand, the moving speed of the movable finger 12 is no longer constant, and the movable body
The interval between 0 and 11 temporarily widens. After that, when the external force is removed, the wafer rapidly moves in the direction of movement of the movable finger 12 before the external force was applied. Furthermore, the fixed finger 17,1
As shown in 8, since one of the pair of grasping fingers is a fixed finger,
There is a problem in that the external force cannot be buffered and absorbed, and there is a high possibility that the wafer being gripped will be damaged. Furthermore, in this gripping device, when an external force that presses the wafer is applied to the movable fingers 12 while gripping the wafer, one of the pair of gripping fingers is a fixed finger, so that the external force can be buffered and absorbed. First, there is a problem in that there is a high possibility that the wafer being gripped will be damaged.

A third conventional example of gripping a semiconductor wafer will be explained with reference to FIG. 13. This example is used in a process in which soldering is performed on electrodes or electrode pads formed on both sides of a wafer. In the conventional process,
The wafer 1a was held between the tweezers 13, dipped into the solder bath 19, held in the solder bath for several seconds, and then quickly pulled up to apply solder to both sides of the wafer 1a.

[0008] The above-mentioned soldering work on both sides of the wafer is carried out manually, and since molten solder is handled, the temperature is 300°C.
The higher the temperature, the higher the risk of burns, the rise in room temperature during work, and the gases generated from melted solder, which worsens the working environment and poses health problems. In addition, since it is done manually, there are individual differences, and there is some variation in quality such as the degree of solder adhesion, making it impossible to produce products of stable quality.In addition, there is a problem that it may crack when inserted into the solder bath. There are also wafers that need to be put away. Furthermore, since the wafer is pinched from both sides with tweezers, the parts sandwiched by the tweezers remain without solder adhering to them, which also causes a decrease in yield.

[0009]

[Problems to be Solved by the Invention] As mentioned above, the device that vacuum-chucks and grips the main surface of a wafer has a very weak gripping force against external forces parallel to the suction surface of the wafer; During suction, an error may occur between the preset suction position and the actual suction position, resulting in poor wafer gripping position accuracy, and the wafer may move or fall while being held. There is an issue of uncertainty in grasping.

[0010] A second conventional gripping device that has been recently attempted alleviates the above-mentioned problems, but since the gripping fingers of this device are configured such that one is a movable finger and the other is a fixed finger, There is a problem in that when an impact force is applied to the movable fingers in a direction that presses the wafer when the wafer is being gripped or while the wafer is being gripped, there is a high possibility that the wafer will be damaged.

An object of the present invention is to enable a wafer gripping device provided at the tip of an arm to grip a wafer reliably with high positional accuracy when or during gripping, and to prevent external force from being applied to the gripping fingers. Another object of the present invention is to provide a wafer gripping device that does not damage the wafer even if the wafer is touched, and another object of the present invention is to provide a wafer gripping device that solves the above-mentioned problems in double-sided soldering of wafers and makes it possible to automate the process. It is to be.

0012

[Means for Solving the Problems] The wafer gripping device of the present invention includes (a) a first movable finger that can move in the longitudinal direction;
(b) rotatably attached to the tip of the first movable finger;
a support claw that supports the wafer by coming into contact with the wafer end surface;
(c) a second movable finger provided in parallel with the first movable finger;
d) a support claw rotatably attached to the tip of the second movable finger and supporting the wafer by contacting the wafer end surface;
e) A first movable finger drive that pushes the wafer end surface with the support claw of the first movable finger, brings the wafer end surface into contact with the support claw of the second movable finger, and holds the wafer between the support claws of the first and second movable fingers. The invention is characterized by comprising a mechanism.

[0013]

[Operation] When gripping a wafer, the first movable finger pushes the end face of the wafer and moves a preset distance, so the wafer can be reliably gripped with a constant force at all times. The wafer gripping fingers consist of first and second movable fingers, do not include fixed fingers, and the supporting claws attached to the tips of each movable fingers are rotatable, so that the wafer can be held by the movable fingers. Even if an external pressing force is applied, it has a buffering effect and can reduce damage to the wafer. Furthermore, since the supporting claws are rotatable, even if there is some positional deviation when supporting the wafer, the position is corrected during the gripping operation, and the wafer gripping position is highly accurate. Since the end surface of the wafer is held in contact with the plurality of supporting claws, the surface of the substrate that will become the product will not be damaged. With the configuration of the wafer gripping device of the present invention, it is easy to automate the gripping and releasing of the wafer, and if desired, by using a material that does not adhere solder to the movable fingers and supporting claws,
It becomes possible to automate the soldering work on both sides of wafers.

[0014]

[Embodiment] FIG. 1 is a partially exploded plan view schematically showing the configuration of a first embodiment of the wafer gripping device of the present invention, and FIG.
is a sectional view taken along the line II-II (see the dashed line in FIG. 1) of this device. Moreover, FIG. 14 is an enlarged plan view of a mechanical part inside the base of the gripping device shown in FIG.

This gripping device has a base body 25 consisting of a pair of end plates 22 and 23 provided on both ends of a bottom plate 21 and a cover 24, and a mechanical portion is provided inside this base body 25. A pair of guide shafts 26 and 27 are attached to a pair of end plates 22 and 23, and a pair of movable bodies 30 are connected to these guide shafts 26 and 27 via ball bushes.
, 31 are slidably supported.

A first movable finger 32 is attached to one of the pair of movable bodies 30, 31, that is, to the upper center of the movable body 30 in this example. The first movable finger 32 extends forward through the end plate 22 of the base body 25, and has a distal end thereof.
A support claw 34 for gripping the wafer 1 by coming into contact with the wafer end face is attached.

Two second movable fingers 37 and 38 are attached to the upper part of the other movable body 31. The second movable fingers 37 and 38 extend forward through the end plate 22 of the base body 25 so as to be located on the same plane as the first movable finger 32. Support claws 35 and 36 similar to the support claws 34 of the movable fingers are attached. Furthermore, the support claw 34 attached to the first movable finger 32 and the support claws 35, 36 attached to the second movable fingers 37, 38 have a mechanism that rotates around the attachment part (see FIGS. 3 and 4). It has become.

Furthermore, an elastic body 5 is provided inside the center of the movable body 31.
0 is stored. This elastic body 50 is attached to a pin 52 whose one end is fixed within the end plate 22 by a screw 51. The movable body 31 moves along the elastic body 50 until the end surface of the wafer moves in the direction 60b and contacts the support claws 35 and 36.
It is pulled toward the end plate 22 side by this. Therefore, when the wafer end surface continues to move as described above after contacting the claws 35 and 36, the elastic body 50
A force in a direction 60a that pulls back, that is, a gripping force is generated.

Further, inside the movable body 31, there is a proximity sensor 43 for measuring the distance d1 between the end plate 22 and the movable body 31.
are fixed with screws 44. The proximity sensor 43 is also provided with a terminal 45 that sends a signal to an external control device when the distance d1 exceeds a predetermined value.

Further, in the movable body 30, a rack 39 having a guide groove 46 for limiting the movement distance is connected to the guide shafts 26, 2 by positioning pins 47a, 47b.
7 so that it can move in parallel. Further, a pinion 40 that meshes with the rack 39 is attached to the output shaft of a motor fixed to the bottom plate 21. Here, positioning pin 47
a, 47b and one end of the guide groove 46, when the movable body 31 is in contact with the end plate 22, the second movable finger 3
It must be equal to or shorter than the distance d2 between 7, 38 and the end plate 22.

A sensor 48 is provided protruding from the tip of the second movable finger 37 to detect the presence or absence of a wafer to be gripped, and sends a signal from a terminal 49 to an external control device.

[0022] Also, inside the movable body 30, a first
An elastic body 53 that buffers the impact force applied to the movable finger 32 is housed, and the metal fitting 54 is enclosed by being attached to the rack 39 with screws 55. Although not shown, the metal fitting 54 is in contact with a lever of a limit switch that has an output terminal that sends a signal to an external control device attached to the outside of the first movable finger 32. It has the function of a metal fitting). Here, the limit switch is for stopping the operation of this gripping device when the movable body 30 exceeds a preset movement range, and it is sufficient if it has a function to send a control signal, but the lever is It is necessary to operate even in response to minute forces.

Furthermore, the first movable finger 32 is connected to the guide shaft 2.
The second movable fingers 37, 38 are linearly movable along the guide shafts 26, 27 and attached to the fixed member via the elastic body 53.
It is attached to the fixed member via the elastic body 50, and the support claw 3
It has the function of buffering and absorbing the impact force applied to the wafers 4, 35, and 36 in the direction of pressing the wafer.

A flange portion 59 is provided on the outside of the end plate 23 for attaching this gripping device to, for example, a robot arm.

Next, the operation of this gripping device will be described. First, the motor is rotated by a preset number of rotations, and the movable body 30 is moved forward in the direction of the arrow 60a via the drive mechanism consisting of the rack 39 and pinion 40.
The spacing between the support claws 34, 35, and 36 attached to the tips of the movable fingers 32, 37, and 38 is widened. Support claws 34, 35
, 36 is made wide enough to allow insertion of the wafer 1 with sufficient margin. In this state, the movable body 30 and the movable body 31 are set so as not to come into contact with each other. In this state, the wafer 1 is inserted between the support claws 34, 35, and 36 by driving, for example, a robot arm that supports this gripping device.

[0026] Thereafter, the motor is reversely rotated by a preset number of rotations to move the movable body 30 backward;
The wafer 1 is brought into contact with the support claw 34 and pulled, and further brought into contact with the support claws 35 and 36 to pull the wafer 1 into the support claw 34.
, 35, and 36.

FIG. 3 shows a sectional view of the support claw 35 (or 36) attached to the second movable finger 37 (or 38), and FIG.
A perspective view of support claws 35 and 36 attached to the tip of the figure is shown. The support claw 35 (or 36) is a roller with a V-shaped groove, and is attached so that it can freely rotate in both directions about a pin 53 screwed to the second movable finger 37 (or 38) as a rotation axis. There is. The support claw 34 attached to the first movable finger 32 has the same structure as the support claws 35 and 36, and can freely rotate around the attachment portion.

[0028] Since the support claws 34, 35, and 36 are designed to be able to rotate freely themselves, when holding a disc-shaped object such as a wafer, the end surface of the wafer does not come into contact with the rollers. , can rotate together with the wafer and grip the center of the wafer with high precision. This is because Figure 5
As shown in the figure, when the supporting claws are fixed to the movable fingers 37 and 38, when a thin plate-like object such as a wafer is gripped, the end of the wafer gets caught in the V-shaped groove of the supporting claws.
The wafer may be supported at two points when it should be supported at three points, and the wafer may wobble during transportation, resulting in poor wafer positioning accuracy. Note that numerals 35a and 36a represent support claws fixed to the movable fingers.

Releasing the gripped wafer is the opposite of the gripping operation described above and is performed in the reverse order of the above operation, so a description thereof will be omitted.

When the gripping device is configured as described above, the wafer can be gripped with a constant force by rotating the motor at a constant number of revolutions, so the gripping force can be adjusted with high accuracy, and it is especially easy to avoid breakage. Since it can securely grip thin wafers that are easily susceptible to damage or deformation, it can prevent damage to the wafers due to dropping, etc. Furthermore, by increasing the output torque of the motor, the force that draws the wafer can be increased, while the force that supports the wafer can be minimized by the elastic body 50.

Regarding the positional error of the wafer, since the supporting claws 34, 35, and 36 have a rotation mechanism, even if the position of the wafer is slightly shifted when the wafer is grasped, the wafer will be rotated as the supporting claws rotate. Error correction is performed during rotation and gripping, allowing for highly accurate positioning.

Furthermore, in this gripping device, the mechanism portion is attached to the base body 2.
5, the gripping portion does not have a complicated structure and is formed in a small size, so that the wafer can be gripped in a small gripping space.

Furthermore, the movable fingers 32, 37, 38 and the movable body 30
, 31 to support the guide shafts 26, 27.
Since the distance between the wafer and the wafer is small and no moment is generated, the supporting claws that grip the wafer can be positioned with high accuracy, and the wafer can be gripped with high precision.

Next, a second embodiment of the present invention will be described with reference to FIGS. 6, 7 and 8. The wafer gripping device of this embodiment is a wafer gripping device installed at the tip of an arm of a robot or the like in a device that directly inserts a wafer into a solder bath and performs automatic soldering of the wafer.

This gripping device has a base body 65 consisting of a pair of end plates 62 and 63 provided at both ends of a bottom plate 61 and a cover 64, and a mechanical portion is provided inside the base body 65. A pair of guide shafts 66 on a pair of end plates 62 and 63
, 67 are attached, and these guide shafts 66, 6
A pair of movable bodies 70 and 71 are movably supported by ball bushes 68 and 69 at 7 . A first movable finger 72 is attached to the center of one of the movable bodies 70 and 71, in this embodiment, the movable body 70, and the movable finger 72 is made of a material to which solder does not adhere, such as titanium. The support claws 74a and 74b extend forward through one end plate 62 of the base body 65, and have support claws 74a and 74b at their tips for contacting the wafer end face and gripping the wafer 1a. . Like the movable fingers 72, the support claws 74a and 74b are made of a material to which solder does not adhere. Further, as shown in FIG. 8, the supporting claws have a V-shaped groove 82 on the side surface so as to be able to sandwich the end surface of the wafer 1a. Further, the other movable body 71 has second movable fingers 77, 7.
8 is attached, and similarly to the first movable finger 72, the end plate 62
Support claws 75 and 76 with V-shaped grooves are attached to the distal end portions extending forward. Furthermore, the support claws 74a, 74b, 75, and 76 are connected to the movable finger 7 that serves as the base.
2, 77, and 78, it has a structure that allows it to freely rotate in both forward and reverse directions with a slight gap. Further, the first and second movable fingers are provided with several holes for the purpose of reducing heat radiation and heat transfer. Furthermore, the movable body 70 has
A rack 79 is attached to move in parallel with the guide shafts 66 and 67, and a pinion 80 that meshes with the rack 79 is attached to the output shaft of a motor 81 fixed to the bottom plate 61.

Next, the operation of this gripping device will be explained. First, the motor 81 is rotated by a preset number of rotations, and the movable body 70 is advanced in the direction in which the first movable finger 72 extends via a drive mechanism consisting of the pinion 80 and the rack 79, and the first and second movable fingers 72 are moved forward. movable fingers 72, 77, 78
Widen the distance between the wafer support claws attached to the wafer. The width at this time is the support claws 74a, 74b and the support claws 75, 7.
Make sure that the space between 6 and 6 is large enough to accommodate the wafer with enough room. In this state, the distance between the movable bodies 70 and 71 is set so that they do not come into contact with each other. In this state, for example, attach the gripping device to the tip of the robot arm, operate the robot,
The wafer placed in a predetermined position is supported by the support claws 74a, 74.
Set it to a position between b, 75, and 76.

After that, the motor 81 is reversely rotated by a preset number of rotations, the movable body 70 is moved backward, and the wafer 1a is pulled by the support claws 74a and 74b.
The wafer 1a is sandwiched between the wafers 5 and 76. At this time, as shown in FIG. 8, the wafer 1a is
, 75, 76, and the supporting claws rotate freely, so even if the center of the wafer 1a is shifted, one of the supporting claws,
For example, even if the wafer 1 contacts the support claw 75 early,
The support claws 75 rotate along the outer periphery of a, and the wafer 1a can be held between the support claws 74a, 74b, 75, and 76.

The wafer 1a gripped by the above operation is
As shown in FIG. 9, the movable fingers 72, 77, and 78 are immersed into the solder bath 84 by the operation of the robot arm 83, etc., but the movable fingers and support claws are made of a material such as titanium that is not compatible with solder. This prevents solder from adhering to the movable fingers, and also prevents the support claws 74a, 7 that sandwich the wafer 1a.
There is no possibility that the wafer 1a and the supporting claws 74a, 74b, 75, 76 will stick to each other, or that solder will remain on the supporting claws 4b, 75, 76, or that solder will not collect on the supporting claws.

The gripping device of the second embodiment described above provides the following effects. That is, (a) when gripping a wafer, the movable fingers are moved at a constant rotational speed, so the gripping force is always constant, making it suitable for gripping easily damaged wafers and the like. (b) By rotating the support claws, the wafer can be supported at three or more points, and the position of the wafer is also corrected while being held, so that some positional deviations can be tolerated when being held. (c) By making the part that is inserted into the solder bath made of a material that does not allow solder to adhere, it is possible to prevent residual solder from adhering and hardening between the wafer and the support claw, and to avoid using excess solder. Therefore, the elements near the support claws were also good. (d) By making the movable fingers inserted into the solder tank long, the driving source can be kept away from the solder liquid level and can be protected from the heat of the solder. (e) Since the outer periphery of the wafer is gripped, soldering can be performed without damaging the elements to be manufactured, and the yield can be improved. (f) Wafers can be automatically gripped and released, making it easy to automate carrier-to-carrier operations in combination with robots, etc., and avoid dangers to the human body (burns, harmful gas, work environment, etc.) This improves safety.

The first movable finger drive mechanism in the first and second embodiments includes a motor fixed to the bottom plate, a pinion attached to its output shaft, a rack meshing with the pinion, a movable body to which the rack is attached, and a movable body. It consists of a guide shaft that moves the body in the longitudinal direction, and the rotation of the motor is converted into linear motion of the movable body using a rack and pinion, but the movable body is not limited thereto. For example, instead of a motor, rotational motion may be transmitted by air drive, or other power transmission mechanisms such as a link mechanism or a belt may be used. Alternatively, the movable body may be directly moved linearly by an air cylinder or the like.

Further, in the first and second embodiments, the second movable fingers are provided on the left and right sides of the first movable finger, but the present invention is not limited to this. For example, first movable fingers may be provided on either side of the second movable finger. That is, a mechanism may be used in which the second movable finger at the center is shortened and the first movable fingers on the left and right sides are lengthened, and the wafer is pulled together by the first movable fingers on the left and right sides. In addition, the second movable finger in the center is lengthened, the left and right first movable fingers are shortened, and the second movable finger in the center is shortened.
The wafer may be brought into contact with the claw of the second movable finger by pushing the end surface of the wafer with the movable finger. Furthermore, the number of support claws provided on the tip of one movable finger may be one or more.

[0042]

[Effects of the Invention] As described above in detail, the present invention enables a wafer gripping device provided at the tip of an arm to reliably grip a wafer with high positional accuracy when or during gripping of a wafer. It is possible to provide a wafer gripping device that can hold a wafer without damaging the wafer even when an external force is applied to the gripping fingers, and also solves the conventional problems in double-sided soldering of a wafer and improves the process. We were able to provide a wafer gripping device that enables automation.

[Brief explanation of the drawing]

FIG. 1 is a partially exploded plan view schematically showing the configuration of a first embodiment of a wafer gripping device of the present invention.

FIG. 2 is a partial cross-sectional view of the wafer gripping device shown in FIG. 1;

FIG. 3 is a sectional view of a support claw attached to a second movable finger of the wafer gripping device shown in FIG. 1;

4 is a perspective view of a second movable finger and its supporting claw of the wafer gripping device shown in FIG. 1; FIG.

FIG. 5 is a sectional view showing a state in which a support claw is fixedly attached to a movable finger.

FIG. 6 is a partially exploded plan view schematically showing the configuration of a second embodiment of the wafer gripping device of the present invention.

FIG. 7 is a cross-sectional view of the wafer gripping device shown in FIG. 6;

8 is a front view of a support claw of the wafer gripping device shown in FIG. 6. FIG.

FIG. 9 is a perspective view of a wafer gripping device according to a second embodiment of the present invention attached to the tip of a robot arm to perform double-sided soldering of a wafer.

FIG. 10 is a perspective view showing a first conventional example of a wafer gripping device.

FIG. 11 is a partial cross-sectional view of the wafer gripping device shown in FIG. 10 for explaining a problem with the device.

FIG. 12 is a plan view showing the configuration of a second conventional example of a wafer gripping device.

FIG. 13 is a diagram illustrating a conventional double-sided wafer soldering operation.

14 is a partially exploded enlarged plan view of a mechanical part inside the base of the wafer gripping device shown in FIG. 1; FIG.

[Explanation of symbols]

1, 1a Wafer 25, 65 Base body 26, 27, 66, 67 Guide shaft 30, 31
, 70, 71 Movable body 32, 72 First movable finger 34, 74 Support claw 35, 36, 75, 76 Support claw

Claims (1)

[Claims] 1. A wafer gripping device provided at the tip of the arm, including (a) a first movable finger that is movable in the longitudinal direction; (b) rotatably attached to the tip of the first movable finger; (c) a second movable finger provided in parallel with the first movable finger; (d) rotatably attached to the tip of the second movable finger; (e) a support claw that supports the wafer by contacting the wafer end surface; A wafer gripping device comprising: a first movable finger drive mechanism that grips a wafer with the supporting claws of the fingers.