JPH02209331A - Wafer suction holder - Google Patents

Abstract

PURPOSE:To enable the optional combination and arrangement of wafers by connecting five sets of tweezers installed in correspondence to respective wafer storage pitches, to an evacuation line via respective solenoid valves, turning these solenoid valves on or off independently, and shortening a span of transfer time. CONSTITUTION:Tweezers 1a, 1b, 1c, 1d and 1e are connected each to an evacuation line 6 via respective solenoid valves 11a, 11b, 11c, 11d and 11e. In addition, the solenoid valves 11a-11e are electrically connected to a controller 12, and turned on or off independently by a driving signal out of this controller 12. With the solenoid valves turned on, the tweezers are interconnected to the evacuation line 6, and released to atmospheric pressure by its off. Each solenoid valve is properly operated by the controller 12 whereby optional sheets of wafers 7 can be attracted and held or released.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is provided in an automatic wafer transfer machine for transferring wafers from a cassette to a boat and from the boat to a cassette in a vertical diffusion furnace and a CVD apparatus. The present invention relates to a wafer suction and gripping device.

[Prior art] In vertical diffusion furnaces and CVD equipment, there is work to transfer wafers from cassettes to boats and from boats to cassettes, and wafers are loaded and unloaded into automatic transfer machines that carry out such transfer work. A wafer suction gripping device is provided.

There are three types of wafers: dummy wafers, monitor wafers, and product wafers, and these must be loaded onto the boat in an appropriate number and arrangement.

Conventionally, a wafer suction and gripping device usually equipped with a vacuum tweezer is used to take out a wafer from a cassette and insert the wafer into a boat. To arrange the wafers on the boat, the three types of wafers mentioned above are taken out from the cassette and transferred to the boat.As shown in FIG. 3. As shown in Figure 3, there is one that has 25 sets of tweezers 1.

To briefly describe the wafer suction and gripping device having a pair of tweezers 1 shown in FIG. 2, the lower suction plate 2 is supported by a transfer is not shown, and a communication 884 is provided inside the suction plate 2. A solenoid valve 5 is provided in the communication path 4.
The solenoid valve 5 is connected to a vacuum pump (not shown) via a vacuum line 6.

Therefore, the suction plate 2 is turned on and off by the solenoid valve 5.
The wafer 7 can be attracted to or released from the upper surface of the wafer 7, and the wafer 7 can be transferred by cooperation with a transfer mechanism.

Since the number of wafers loaded in the cassette is 25, the gripping device shown in FIG.
There are 25 sets of .

The tweezers 1 are connected to a vacuum exhaust line 6 through a common solenoid valve 8, and 25 wafers are attracted to or released from 25 sets of tweezers 1 at once by turning the solenoid valve 8 ON and OFF. It has become.

[Problems to be Solved by the Invention] However, the above-mentioned conventional device has the following problems.

The former gripping device with one set of tweezers holds the wafer in one
It is a so-called single-wafer system in which wafers are picked up one by one and transferred by a transfer mechanism, and it is possible to arrange any number of three types of wafers on the boat in any arrangement, but the transfer operation is Transfers are carried out frequently and take time. Furthermore, frequent transfer operations also cause dust generation.

The latter type of gripping device having 25 sets of tweezers picks up 25 wafers and transfers them at once using a transfer mechanism, so to speak, and the transfer mechanism shortens the transfer time. However, it is necessary to manually insert and arrange three types of wafers in a cassette in advance so as to form a desired combination.

Therefore, the work is very complicated, and there is a risk of erroneous insertion, as well as generation of dust and contamination of the wafer.

In view of these circumstances, the present invention aims to provide a wafer suction and gripping device that shortens the transfer time and allows arbitrary combinations and arrangements of wafers.

[Means for Solving the Problems] The present invention provides a wafer suction and gripping device included in an automatic wafer transfer machine, in which five sets of tweezers for suctioning and gripping wafers are provided corresponding to the wafer storage pitch, and each tweezer is are each connected to the vacuum exhaust line via a solenoid valve,
The solenoid valve can be turned on and off independently by the controller.
This feature is characterized in that it is configured in such a way that it can be used.

[Function] By turning the solenoid valves ON and OFF independently by the controller, the 5 sets of tweezers can individually attract and release wafers, and can grip any number of wafers in the range of 1 to 5. can do.

[Example] An embodiment of the present invention will be described below with reference to the drawings.

The tweezers 1a and l are attached to the support shaft 10 next to the transfer Ii (not shown).
Attach 5 sets of b, 1c, Id, and 1e according to the wafer storage pitch of the cassette. The tweezers 1a, 1b, 1
Since c1d and Ie have the same configuration as the tweezer 1 described above, a description thereof will be omitted.

Each tweezer Ia, Ib, 1c, ld, 1e is
Solenoid valves 11a, 11b, 11c, 11d, respectively
, 11e to the vacuum exhaust line 6. Also, the solenoid valves 11a and 11b.

11c, lid, and 11e are electrically connected to a controller 12, and are turned on and off independently by drive signals from the controller 12.

When these solenoid valves are turned ON, the tweeter is communicated with the vacuum exhaust line 6, and when these solenoid valves are turned OFF, it is released to atmospheric pressure.

According to the above configuration, it is possible to suction and hold any number of wafers 7 in the range of 1 to 5. That is, when holding five wafers 7 by suction, the solenoid valves 11a, 1
1b, 11c, lid, and 11e are all turned on, and all tweezers 1a, Ib, 1c, 1d, and 1e are communicated with the vacuum exhaust line 6, and the wafer 7 is attached and gripped.

In addition, when holding three wafers 7 by suction, the solenoid valve 11
a, 11b, and 11c are connected to the ONL, and the upper three sets of tweezers 1a, 1b, and Ic are connected to the evacuation line 6, and the three wafers 7 are held by suction.

Furthermore, when holding one wafer 7 by suction, the solenoid valve 1
1a is connected to the ONL, the uppermost tweezer 1a is connected to the evacuation line 6, and one wafer 7 is held by suction.

When holding two or four wafers 7 by suction, the corresponding number of wafers 7 may be operated from the upper solenoid valve in the same manner.

By appropriately operating the electromagnetic valves using the controller 12, an arbitrary number of wafers 7 can be gripped or released.

[Effect of the invention] By equipping an automatic transfer machine with such a wafer suction and gripping device, 25 wafers are normally loaded in a wafer cassette, but 5 wafers can be transferred 5 times in one cassette. Once the loading operation is completed, any number of wafers including one can be suctioned and held, making it possible to insert a monitor wafer for each required number of product wafers. Furthermore, it is possible to handle any number of product wafers and dummy wafers to be transferred, no more than five.

Therefore, it is possible to transfer wafers such that any number of wafers, dummy wafers, monitor wafers, and product wafers, and product wafers are arranged in any desired number.

In addition, since the number of wafers to be suctioned and gripped is 5, which is a common divisor of 25 wafers, which is the number of wafers loaded in the wafer cassette, it has excellent effects such as easy software processing by the controller and the ability to handle complex combination conditions. It is possible.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing one embodiment of the present invention, FIG. 2 is an explanatory diagram of a conventional example, and FIG. 3 is an explanatory diagram of another conventional example. 1, Ia, 1b, 1c, 1d, 1e are tweezers, 6 is a vacuum exhaust line, 11a, 11b, 11c
, 11d and 11e are tFa valves, and 12 is a controller. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1) In the wafer suction and gripping device included in the automatic wafer transfer machine, five sets of tweezers for suctioning and gripping wafers are provided corresponding to the wafer storage pitch, and each tweezer is connected to the vacuum exhaust line via a solenoid valve. 1. A wafer suction and gripping device, characterized in that the solenoid valves are connected to each other and configured so that the solenoid valves can be turned on and off independently by a controller.