JPS6290945A - Conveying method for wafer - Google Patents

Abstract

PURPOSE:To smoothly convey a wafer without precipitating at a branch in case of branching the conveying passage of the wafer into two by reversely turning a conveying belt of non-placing side to the conveying belt of a placing side rotating in the same direction as the feeding direction in the branched conveying passages of approximately Y shape. CONSTITUTION:When a wafer 1 is conveyed from a processor A by the normal rotation of a conveying belt 2, a sensor 8 detects the arrival of the wafer 1. If the wafer 1 is input, for example, in a processor B of rear stage, a belt rotation controller which is operated by a detection signal of the sensor 8 normally rotates belts 3, 5, and reversely rotates a belt 4. Then, the wafer 1 is moved from the bent 2 to the belts 3, 5, and input to the processor B. When the wafers 1 are continuously conveyed at an interval on the belt 2, the sensor 8 detects the wafers 1 sequentially arriving, a sensor 9 feeds the arrival signal of the wafer 1 to a belt rotation controller, which normally rotates the belts 4, 6 and reversely rotates the belt 3 to input the next wafer 1 in a processor C.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for transporting a wafer, and more particularly to a method for transporting a wafer using a transport belt.

(Prior art) Various processes performed on semiconductor wafers, such as resist coating and exposure in the photolithography process, require different processing equipment, so the wafers that have been coated with resist are placed on a conveyor belt and transferred to the exposure equipment. be transported. Transferring wafers using this conveyor belt method is extremely useful because the movement of wafers can be automated. However, the processing capacity of the processing device installed at the front stage of the conveyor belt is the processing capacity of the processing device installed at the rear stage (both are processing capacity per unit time).
If there is a large difference compared to K, for example a 2:1 relationship,
Wafers that are loaded at the later stages are inconveniently loaded.

Conventional techniques for avoiding such inconveniences include, for example, the U.S. Pat.
-76372, JP-A-55-22832, etc. In all of these methods, the above-mentioned problems are solved by dividing or sorting the conveyed objects, which are conveyed in one line, into two lines by the device.

(Problems to be Solved by the Invention) However, these prior art techniques require a special sorting mechanism in addition to the conveyance path, and furthermore, these sorting requires a drive device to drive the mechanism. The manufacturing process of semiconductor devices, especially the exposure of the photolithography process, and the transportation of the wafer to the development equipment,
Due to the extreme dislike of dust and the need to maintain smooth transportation in order to minimize the change over time of Lennost, a simple transportation method with fewer transportation troubles is required, but this is not yet satisfactory. do not have.

(Means for solving the problem) This invention uses three conveyor belts to transport wafers, and
By configuring a letter-shaped branch conveyance path and controlling the rotational direction of the drive device for the conveyance belt, the branch conveyance path can:
This is a method of changing the wafer transport direction, and specifically, when transferring a wafer that is transported along a branch transport path by the rotation of the first transport belt onto the second or third transport belt, Either one of the second and third conveyor belts is connected to the first conveyor belt.
This is a conveying method in which one conveyor belt is rotated in the same direction as the other conveyor belt, and the other conveyor belt is rotated in the opposite direction.

(Function) In the Y-shaped branch conveyance path, the conveyor belt on the transfer side rotates in the same direction as the transfer direction, and the conveyor belt on the non-transfer side rotates in the opposite direction, so the non-transfer side transfers wafers to the transfer side. It acts to push out the wafer, thereby preventing the wafer from stagnation on the branch conveyance path.

(Example) FIG. 1 is a schematic plan view of an example apparatus employing the method of this invention, where l represents a wafer, 2 to 6 represent a conveyor belt (hereinafter sometimes simply referred to as a belt), and 2 represents a wafer. Inner guide, 8
- 12 represent sensors for detecting the arrival of a wafer, and 13 and 14 represent outer guides, respectively. Further, the arrow indicates the direction in which the wafer is transferred in the branched transfer path section. belt 2
6 to 6 place the wafer 1 thereon by rotating forward or reverse, each independently or in conjunction with a certain portion of the belt. Furthermore, the inner guide 7 and the outer guide 13.14
Since this is a guide for the transport path of Ueno 1, it forms a wall that is higher than the height of the conveyor belts 2 to 6 plus the thickness of Ueno/%l. Further, the forward rotation described in the present invention is assumed to be right rotation throughout the specification.

Now, the wafer transport method of the present invention will be explained in detail with reference to FIG.
When the wafer l is conveyed by normal rotation of the conveyor belt 2, a sensor 8 detects the arrival of the wafer l, and a belt rotation control device (not shown) determines whether to supply the wafer l to either the subsequent device B or C at the branching point. Determine the direction of rotation. For example, when loading a wafer l into the processing equipment MB at the subsequent stage, the sensor 8
The belt rotation control device activated by the detection signal rotates belts 3 and 5 in the forward direction and rotates the belt 4 in the reverse direction. Then, the wafer 1 moves from belt 2 to belt 3 and belt 5, and is loaded (loaded) into apparatus B. When the wafers 1 are continuously conveyed on the belt 2 at certain intervals, the sensor 8 detects the wafers 1 that arrive one after another, and the sensor 9 sends an arrival signal of the wafer 1 to the belt rotation control device.
In order to load the next wafer 1 into apparatus C, belts 4 and 6
is rotated in the forward direction and the belt 3 is rotated in the reverse direction. If the distance between the wafers 1 conveyed on the belt 2 is enough for the wafers 1 to pass through the sensor 8 and be input into the subsequent processing device B or C, the sensors 9 and 10 are not necessarily required.

In other words, the belts 3 and 4 may be rotated alternately from forward to reverse and from reverse to forward based on the passing signal from sensor 8. However, it must be noted that the conveyor belts 3 and 4 must always be rotated in an opposite relationship. That is, when transferring the wafer l to the belt 2 collar belt 3 or belt 4, the wafer l stagnates at the branching portion and often does not get transferred to the belt 3 or 4. One of the belts 3 or 4 rotates in the opposite direction to the conveying direction in the device B in the latter stage.
or C, for example, to prevent the wafer 1 from entering the apparatus C by reverse rotation, and to send the wafer 1 to the conveyor belt 3 for conveying the wafer 1 in the direction of the apparatus B.

In addition, in this embodiment device, the conveyor pel) 2.3° 4.5
By reversing the rotation of 6 and 6, it is possible to ensure a stable supply of the ueno l carried out from the devices B and C to the device AK, which has a processing capacity equal to the total processing capacity of the two devices iB and C. The present invention can also be used in such cases.

In this case as well, belts 3 and 4 must of course be rotated in opposite directions. Then, the sea urchins carried out from devices B and C)'10 are at the confluence section (in the above example, the branch section)
The conveyance of the ueno l can be controlled by the rotation of the belts 5 and 6 based on the signals detected by the sensors 11 and 12 so as to prevent them from colliding with each other.

Since the rotations of the conveyor belts 3 and 4 are always reversed and rotate synchronously, two drive sources, such as motors, are used.
The motors may be installed in parallel and rotated in synchronization, or they may be constructed by a combination of one motor 13, a pulley 14, and a chain 15, as shown in FIG. Note that the arrow in FIG. 2 represents the direction of rotation.

(Effects of the Invention) As described above, the present invention provides a method for branching the wafer transport path into two in wafer transport using a transport belt system that connects processing equipment that performs various processes on semiconductor urchins. In addition to the first major effect, which is that wafers can be transported smoothly without stagnation at the branching section, the processing capacity per unit time of the processing equipment installed at the front stage of this transport path and the processing equipment installed at the rear stage is also improved. When adopted in this type of system, it exhibits outstanding effects, such as being able to correct unevenness in the amount of conveyance due to balance or patch processing (batch processing) and individual processing. In addition, in the method of the present invention, the sea urchins can be conveyed in a branched manner only by controlling the rotational direction of the conveyor belt, so that the sorting can be realized with a simple device that does not require any mechanism.

[Brief explanation of drawings]

FIG. 1 is a schematic plan view of an embodiment of an apparatus employing the method of the present invention, and FIG. 2 is an explanatory diagram of the conveyor belt drive method of the present invention. DESCRIPTION OF SYMBOLS 1... Wafer, 2-6... Conveyor belt, 2... Inner guide, 8-12... Sensor, 13.14... Outer guide, A, B, C... Processing device, A... Branch conveyance tread patent applicant: Oki Electric Industry Co., Ltd. Figure 1, $4
figure

Claims (1)

[Claims] (1) A substantially Y-shaped branched conveyance path is formed by the first, second, and third conveyor belts, and the semiconductor wafer is placed on the first conveyor belt and transferred by the movement of the conveyor belt. In the wafer transport method, the wafer is transported to either the second or third transport belt on the branch transport path,
By rotating one of the second and third conveyor belts in the same direction as the first conveyor belt and rotating the other in the opposite direction, the a second rotating the wafer in the same direction;
A method for transporting a wafer, the method comprising transporting a wafer to either one of a third transport belt.