JPH0318435Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to an improvement in an apparatus for holding a plate, such as a silicon wafer.

Prior Art There are many steps in the manufacturing process of silicon wafers, which serve as substrates for semiconductor components. When the slicing process is completed during this process, the wafer is handled as one wafer. After this step, there are processing steps such as wrapping and polishing, and after several measurements and inspections, the silicon wafer becomes a finished product.

Between each of these steps, the wafer must be transported, but conventionally, this transport has typically been carried out using round belts,
Alternatively, the wafers are stored in a special wafer cassette using a vacuum chuck or the like.

When feeding wafers into a wafer cassette,
Alternatively, if a round belt or vacuum chuck is used to discharge the wafer from inside, the round belt or wafer chuck will come into direct contact with the back surface of the wafer. During such a holding process, if part of the conveying means comes into surface contact with the surface of the wafer, marks such as vacuum chucks or round belts will be deposited on the surface of the wafer. Although the contact position is on the back side of the wafer, it causes dust generation, which poses a problem in semiconductor manufacturing processes that require cleanliness.

Purpose of the invention Therefore, the purpose of the invention is to avoid surface contact with a plate such as a wafer when handling the plate,
By holding the outer periphery of the plate in point contact, dust generation is minimized.

Summary of the Invention Accordingly, in the present invention, the outer circumferential surface of the plate is held in a three-point supported state by, for example, the holding parts of the three gripper parts. Here, two of the three holding parts are fixed at fixed positions, but the other one is biased by a spring in the gripping direction and can be moved back and forth by a drive source. It is provided. Therefore, when this movable holding part is moved forward by the drive source and comes into contact with the side surface of the plate, its gripping force is applied by the spring, and a certain degree of dimensional error is allowed. This allows for flexible holding operations without damaging the wafer, etc.

Structure of the invention FIGS. 1 and 2 show the holding device 1 of the invention.
It shows. This holding device 1 includes a pair of fixed grippers 2 and a movable gripper 3.
Of these, a pair of grippers 2
is detachably fixed to the upper surface of the gripper part 4, and the other gripper 3 is provided so as to be movable forward and backward by a push rod 5 between them.

The pair of grippers 2 use their tip portions to hold the roller-shaped first holding portion 7, for example, with a pin 6.
Similarly, the other gripper 3 has a roller-like second holding part 9 rotatably held by a pin 8 at its approximately central portion. There is. Both of the first and second holding parts 7 and 9 are replaceable for cleaning, and are made of an elastic material such as urethane rubber, and hold the wafer 31 as a plate in the vertical direction. It is in a state where it can absorb variations.

The gripper 3 is bent into an L shape, and the optical sensor 10 is fixed on the front surface thereof.
The lead wire 11 of this optical sensor 10 is led into the interior of the gripper section 4 with a grommet or the like interposed therebetween.

On the other hand, the push rod 5 is slidably inserted into a sliding bearing 12 attached to the front surface of the gripper part 4, and is fixed to a rotation stop plate 14 by a fixing member 13 at an intermediate portion thereof. Further, the rear end portion is inserted into the pusher 16 of the slider 15 so as to be slidable in the axial direction, and the distal end portion is provided with a stopper 17 such as a screw.
The anti-rotation plate 14 and the slider 15
are slidably supported inside the gripper section 4 between the bushes 18 and 19 at both ends thereof, with respect to a pair of parallel guide bars 20 spanning between the gripper section 4 and the cover plate 4a. There is.
A coil-shaped spring 21 is provided on the push rod 5 between the detent plate 14 and the slider 15.

Further, the slider 15 is connected to a piston rod 23 of a cylinder 22 as a driving source. This cylinder 22 is provided inside the gripper part 4 and is attached by a bracket 24. In this way, the second presser part 9 is connected to the cylinder 22 as a driving source by the spring 21.

The pair of grippers 2 are inserted into the positioning holes 26 of the gripper part 4 by grooved positioning pins 25, as shown in FIG.
Since it is locked by a ball plunger 27 screwed into the gripper part 4, it can be easily replaced with one of a different size. Further, the sliding part of the push rod 5 is sealed by a scraper 28 inside the pocket 32, and the pocket 32 is connected to the suction pipe 2.
9, it is always in a suction state with negative pressure air.

Effect of the invention The above-mentioned holding device 1 is attached to the head 30 of a working robot.
The wafer 31 is attached to the upper part of the wafer 31, and its movement causes it to move below the wafer 31. In this state, after the optical sensor 10 photoelectrically confirms the presence or absence of the wafer 31, the gripper 2 rises slightly. The wafer 31 is housed in a trough-shaped portion and can be taken out by the grippers 2 and 3. After the grippers 2 and 3 rise, the head 30 of the robot pulls out the wafer 31 with the two first holding parts 7, and then the cylinder 22 pulls in its piston rod 23, so the second holding part 9 It is pushed by the spring 21 and comes into contact with the outer peripheral surface of the wafer 31 while moving forward. In this way, the wafer 31 is held between the two first holding parts 7 and the second holding part 9 in a three-point supported state. At this time, the second presser part 9
The contact pressure is applied via the spring 21. Therefore, no more force than necessary is applied to the wafer 31, and variations in the size thereof are absorbed by the spring 21. After the wafer 31 is gripped by the first and second holding parts 7 and 9 in this way, the head 30 of the robot
While holding the wafer 31, the wafer 31 is transported to a working position for a predetermined process.

Modified example of the invention In the above embodiment, two first presser parts 7 are fixed.
On the other hand, although one second presser part 9 is in a movable state, the relationship of arrangement thereof may be opposite to that of the embodiment. However, the two first holding parts 7 can also be integrally configured as one piece. Furthermore, this second presser part 9
is not limited to one, but may be more than one, for example two.

Further, the drive source is not limited to the cylinder 22, but can also be configured by converting the rotation of a rotary actuator, a motor, etc. into linear motion using a Kunk mechanism, a feed screw mechanism, or the like.

Of course, the use of this holding device 1 is not limited to semiconductors such as wafers, but can also be used for transporting other plate-shaped objects.

Effects of the invention In this invention, the plate such as a wafer is stably held by the first and second holding parts not in surface contact but in point contact on its outer periphery, which makes it easier to use in actual use. Since no dust adheres to the surface or leaves marks when holding, there is no negative impact on quality in the subsequent manufacturing process, and when the second holding part touches the side of the plate, the spring Since the gripping force is exerted by the elasticity of the wafer, no unreasonable external force is applied to the plate such as a wafer, and variations in size can be absorbed to some extent.

[Brief explanation of the drawing]

Figure 1 is a vertical sectional view of the holding device of the present invention;
The figure is a horizontal sectional view of a portion, and FIG. 3 is an enlarged sectional view of the gripper attachment part. 1...Holding device, 2, 3...Gripper, 4...
...gripper section, 5... push rod, 7...
First holding part, 9...Second holding part, 14...Stopping plate, 15...Slider, 20...Guide bar, 21...Spring, 22...Cylinder as a driving source, 31... Wafer as a plate.

Claims (1)

[Claims for Utility Model Registration] At least one first holding part 7 that contacts one side of the circumferential surface of a plate 31 such as a wafer is attached to the gripper part 4.
At least one second holding part 9 is provided on the gripper part 4 so as to be able to move forward and backward in the direction of the first holding part 7, and is supported in a fixed position and comes into contact with the other side of the circumferential surface of the plate body 31. The second presser section 9 is connected to a drive source 22 provided in the gripper section 4 by a spring 21, and the first presser section 7 and the second presser section 9 use the urging force of the spring 21 to press the plate body. 31. A holding device 1 for a plate such as a wafer, characterized in that the circumferential side surface is held between at least three points from both sides.