JP2003174068A - Device for confirming seating of wafer carrying container - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect positional shift of a wafer carrying container by a more accurate method causing no impediment to the work. <P>SOLUTION: A coupling pin 4 is made hollow, two through holes (a) and (a) are bored obliquely upward and an end part is opened in a cut part (b) provided in the side face. The through holes (a) and (a) are board in such a direction as the axes intersect the inclining face of a V-groove 2 made in the bottom face of a wafer carrying container perpendicularly and cross at point A. A diffuse reflection type optical fiber 7 is inserted into the through holes (a) and (a) and light on the projecting side is reflected to point A of the V- groove 2 and received on the light receiving side. When the quantity of light reflected from the point A exceeds a preset threshold level, the output is inverted and a fact that the coupling pin 4 is fitted in the V-groove 2 as specified is detected. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for confirming whether or not a wafer transfer container is properly set at a fixed position on a semiconductor manufacturing line. [0002] A wafer transport container is
A 12-inch wafer weighing 200 kg is housed in a multi-layer stack, and is put in and out from the front with a robot arm. Therefore, if the wafer transport container is not set correctly at a fixed position, the wafer and the container will be damaged. As shown in FIG. 1, a wafer transfer container 1 is provided with three V-shaped grooves 2 on the bottom of the container,
The three more protruding coupling pins 4 are inserted and set in place. Since the directions of the V-shaped grooves 2 are different from each other by 120 °, when the connecting pin 4 is inserted and fitted, the wafer transport container 1
Will not move in any direction. [0004] The wafer transport container 1 is sometimes set with the connecting pin 4 being disengaged from the V-shaped groove 2. At this time, the wafer transport container 1 is tilted in one of the upper and lower directions. Therefore, as shown in FIG. 2, the conventional seating confirmation device attaches a sensing pad 5 for adjusting the height in the vicinity of the coupling pin 4 and a contact or non-contact sensor 6 on the sensing pad 5 to adjust the height of the bottom surface. Was measured. As a result, when the height of the bottom surface is different from the predetermined height, it is determined that the wafer transport container 1 is tilted up and down, and the presence / absence of displacement is indirectly detected. However, depending on how the wafer transport container 1 is placed, the wafer may not be tilted even if it is displaced.
It was impossible for the conventional seating confirmation device to detect 100% displacement. In addition, since the sensing pad 5 and the sensor 6 protrude from the pedestal 3, they hinder the work and may be damaged at the same time. SUMMARY OF THE INVENTION It is an object of the present invention to make it possible to detect a position shift of a wafer transport container in a more reliable and non-obstructive manner. [0007] In order to achieve the above object, the present invention is configured as follows. That is, in a configuration in which a connecting pin protruding from a pedestal is inserted into a V-shaped groove provided on the bottom surface of the container to set the wafer transfer container in a fixed position, a reflection-type optical sensor is embedded in the connecting pin. Based on the output signal of the optical sensor, the insertion of the coupling pin into the V-shaped groove is detected, and the seating of the wafer transport container is confirmed by checking whether the wafer transport container is correctly set at a fixed position. Device. Embodiments of the present invention will be described below with reference to the drawings. FIG. 3 is a longitudinal sectional view of a device for confirming seating of a wafer transfer container embodying the present invention. The seating confirmation device for a wafer transfer container makes the inside of the coupling pin 4 hollow, drills two through holes a, obliquely upward from there, and opens the terminal end to the cutout b provided on the side surface. . Through holes a, a
Is formed in a direction in which the axis intersects at right angles with the inclined surface of the V-shaped groove 2 and intersects at point A. Then, as shown in FIG. 4, a diffuse reflection type optical fiber sensor 7 is inserted into the through holes a, a, and the light on the light projecting side is reflected to the point A of the V-shaped groove 2 and received on the light receiving side. . At this time, when the amount of reflected light from the point A exceeds the set threshold level, the output is inverted, and it is detected that the coupling pin 4 has been fitted in the V-shaped groove 2 as specified. Hereinafter, a method of detecting a positional shift will be described with reference to the schematic diagram of FIG. The detection of the displacement is performed based on the output signal of the optical fiber sensor 7 embedded in the left and right coupling pins 4 located below, and the arrow in the figure indicates the optical axis direction of the optical fiber sensor 7. FIG. 5A shows a state in which the right and left coupling pins 4 are correctly set in the V-shaped groove 2. At this time, since both signals of the optical fiber sensor 7 are turned on, there is no displacement. Detect that. FIG. 5 (b) shows a state in which the right and left coupling pins 4 are shifted to the right of the V-shaped groove 2. At this time, the left side of the optical fiber sensor 7 is turned on and the right side is turned off. Detect that there is. FIG. 5 (c) shows a state in which the left and right coupling pins 4 are shifted to the left of the V-shaped groove 2. At this time, since the left side of the optical fiber sensor 7 is OFF and the right side is ON, the positional shift is caused. Detect that there is. As described above, the apparatus for confirming seating of a wafer transport container according to the present invention has a reflection type optical sensor embedded in a connection pin, and based on an output signal from the reflection-type optical sensor, enters the V-shaped groove of the connection pin. Is detected, and it is confirmed whether or not the wafer transport container is correctly set at a fixed position. Therefore,
According to the present invention, an optical sensor is built in
Since the insertion into the groove is detected, the presence or absence of a positional deviation can be confirmed more reliably than in the conventional detection method. In addition, since the optical sensor is built into the coupling pin, even if the sensor is attached, it does not hinder the operation, and the sensor is not likely to be damaged.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of a method for setting a wafer transfer container embodying the present invention. FIG. 2 is a cross-sectional view of a conventional wafer transfer container seating confirmation device. FIG. 3 is a sectional view of a device for confirming seating of a wafer transfer container embodying the present invention. FIG. 4 is a schematic view of an optical fiber sensor embodying the present invention. FIG. 5 is a schematic diagram illustrating a method for detecting a position shift according to the present invention. [Description of Signs] 1 Wafer transport container 2 V-shaped groove 3 Base 4 Connecting pin 5 Sensing pad 6 Sensor 7 Optical fiber sensor a Through hole b Notch

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Claims (1)

Claims: 1. A configuration in which a connecting pin protruding from a pedestal is inserted into a V-shaped groove provided on a bottom surface of a container to set a wafer transfer container in a fixed position. The optical sensor is embedded, and based on the output signal of the optical sensor, the insertion of the coupling pin into the V-shaped groove is detected, and it is confirmed whether the wafer transport container is correctly set at a fixed position. Wafer transport container seating confirmation device.