JPH0713222Y2 - Wafer cassette positioning detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a wafer cassette positioning detection device for detecting whether or not a wafer cassette is correctly placed on a cassette pedestal.

<Prior Art> A thin plate-shaped object to be processed (hereinafter referred to as a wafer) such as a silicon wafer is processed one by one from a wafer cassette in a processing step, such as a resist coating step, or It is processed while being stored in the wafer cassette like the immersion cleaning process. In order to feed a wafer to such a processing step, it is necessary to arrange the cassette in a desired posture according to the type of the processing step and to properly mount it on the cassette pedestal. Otherwise, not only will the wafers not be smoothly fed and the wafer cassettes will not be delivered, but sometimes,
This is because the wafer may be damaged. In order to eliminate such inconvenience, conventionally, a cassette pedestal with a cassette detection mechanism as shown in the perspective view of FIG. 6 has been used. It is configured such that the cassette receiving base 110, a pair of guides 112 and 112 standing upright on the cassette receiving base 110 at a predetermined distance from each other, and the detection end 114a of the guide 112 protrude from the receiving surface 112a of one guide 112. The wafer cassette 100, which is composed of a detector 114 such as a limit switch arranged and stores a plurality of wafers W, is hung and transferred by, for example, a cassette transfer robot 120, and a cassette pedestal 110.
Placed on top.

At this time, even if the mounted wafer cassette 100 is slightly displaced from the predetermined position, as shown in FIG. 7, one leg 102 of the wafer cassette 100 has the detection end 114a of the detector 114. May be pressed, which may hinder the subsequent transportation of the wafer or wafer cassette.

<Problems to be Solved by the Invention> Although the above-mentioned conventional example has a simple structure and is useful as such, it is ensured that the wafer cassette is accurately placed at a predetermined position on the cassette pedestal. It is insufficient as a mechanism for detection.

The present invention was made in consideration of such circumstances,
A technical problem is to make it possible to detect the presence of a cassette only when the wafer cassette is correctly placed at a predetermined position on the cassette cradle.

<Means for Solving the Problems> In order to solve the above problems, the present invention is configured as follows.

That is, a pair of left and right guides standing upright on the cassette pedestal at a predetermined interval, a pair of left and right cassette receiving surfaces provided along the inside of the pair of guides, and a detection installed over the pair of left and right cassette receiving surfaces. A rocking lever for use, a support having one end fixed and the other end being a free end,
The free end supports the central part of the swing lever for detection,
The detection swing lever can swing freely in a vertical plane, and
The wafer cassette is provided with a support for movably supporting up and down, a subject fixed to a central portion of the detection swing lever, and a detector for detecting the subject. It is characterized in that the presence of the wafer cassette is detected by simultaneously pushing down both ends of the lever.

<Operation> In the present invention, the wafer cassette is received by the pair of left and right cassette receiving surfaces provided along the inside of the pair of guides. A rocking lever for detection is installed on the pair of left and right cassette receiving surfaces. The central part of this rocking lever for detection is
Since the one end is supported by the free end of the support fixture, the detection rocking lever is supported so as to be rockable in the vertical plane and vertically movable. Therefore, only when the wafer cassette pushes down both ends of the detection rocking lever at the same time, the detection rocking lever descends by a predetermined stroke, and the object fixed to the central part of the detection rocking lever descends by a predetermined stroke. A detector detects the presence of the wafer cassette. That is, the presence of the cassette can be detected only when the wafer cassette is accurately placed on the wafer cassette pedestal.

<Embodiment> An embodiment of the present invention will be described below with reference to the drawings. First
1 to 4 show a first embodiment according to the present invention, FIG. 1 is a perspective view thereof, FIG. 2 is a plan view, and FIG. 3 is III of FIG.
FIG. 4 is a partially enlarged sectional view of the subject mounting portion, taken along line III-III.

This positioning detecting device is installed across a cassette receiving base 1, a pair of guides 2 and 2 which are vertically provided on the upper and lower sides of the cassette 1 and spaced apart from each other by a predetermined distance, and receiving surfaces 2a and 2a of the pair of guides 2 and 2. Detecting rocking lever 3, a support tool 5 that supports the detecting rocking lever 3 so as to be vertically movable and rotatable, a subject 7 attached to a central portion of the detecting rocking lever 3, and a cradle 1. And a detector 8 for detecting the subject 7.

Reference numeral 13 (13A and 13B) in FIG. 2 is a position correction claw used to position the cassette at the correct position, and the wafer cassette is always slightly displaced in the front-back direction (arrow A). It is placed on the pedestal 1 and then the rear end of the leg 11 of the wafer cassette 10 is pushed to a predetermined position in the direction of arrow C by the position correction claw 13A, and then the correction claw 13B is received from below the pedestal 1 By raising to 1 surface,
The wafer cassette 10 is configured to be correctly positioned in the front-rear direction (direction of FIG. 2A).

The support 5 is formed of a leaf spring 5a. One end of the leaf spring 5a is rotatably attached to the center of the subject 7, and the other end of the leaf spring 5a is fixed to the center of the lower surface of the pedestal 1. The swing lever 3 for detection is elastically supported via 7 so as to be vertically movable and rotatable.

FIG. 4 shows a state where the one end of the leaf spring 5a is attached to the subject.
In a partially enlarged cross-sectional view showing an example, the subject 7 is fixed to the central portion of the detection rocking lever 3 in the axial direction by welding or the like. In addition, a pin 20 whose one end is welded to the leaf spring 5a is loosely fitted in the opening 7a of the subject 7, and the E-ring is inserted in the groove 21 at the multi-end of the pin 20.
22 is fitted and the subject 7 is rotatably supported.

The detector 8 is composed of, for example, an optical sensor having a light emitting element and a light receiving element, and the object 7 is moved down a certain stroke to block the light incident on the light receiving element. It is configured to detect that it has been placed. The pair of guides 2 and 2 are formed with a recessed portion 2c, and the leg portion of the wafer cassette 10 is formed.
When the rocking lever 3 is pushed down at 11, both end portions 3a thereof are fitted into the recessed portions 2c.

Further, the guides 2 and 2 do not necessarily have a shape having the receiving surface 2a, and may have a shape without the receiving surface 2a, in which case a concave portion into which both end portions 3a of the detection swing lever 3 are fitted. The insertion part is formed as a notch in the pedestal 1. Therefore, as shown by the broken line in FIG. 3, the wafer cassette 10 is not properly placed on the cassette receiving table 1, and one leg 11 of the wafer cassette 10 is placed on the inclined surface 2b of the guide 2 in a mounted state. In this case, both ends 3a of the detection swing lever 3 do not descend at the same time, and the subject 7 descends in a tilted state, so that the detector 7 does not detect the subject 7 and the wafer cassette 10 Is not correctly placed on the cassette cradle 1.

FIG. 5 is a perspective view of an essential part showing a second embodiment of the present invention.

In this embodiment, the detection rocking lever 3 is located below the receiving surface 2a, the character-shaped contact pieces 4 are attached to both ends of the detection rocking lever 3, and both ends 4a of the contact piece 4 are received. It is made to project on the surface 2a and abut on the lower surface of the leg portion 11 of the wafer cassette 10 at two points.

In the above-described embodiment, the detector is constituted by the optical sensor, but it may be replaced by a magnetic sensor or an electrostatic sensor, or a reflection type optical sensor having both light emitting and receiving parts on one side.

Further, in the above embodiment, the leg of the wafer cassette is received by the receiving surface. However, when the wafer W is placed on the receiving surface in a horizontal state, the wafer supporting groove is formed in place of the leg. Any side plate can be used as long as it can be received by the receiving surface.

<Effect of Device> As is apparent from the above description, in the present invention, the object is detected only when both ends of the detection rocking lever are pushed down by the pair of legs (side plates) of the wafer cassette at the same time. Therefore, the presence of the cassette can be detected only when the wafer cassette is properly placed on the cassette pedestal.

[Brief description of drawings]

1 to 5 show an embodiment according to the present invention, FIG. 1 is a perspective view of the first embodiment, FIG. 2 is a plan view thereof, and FIG. 3 is a III-III line of FIG. FIG. 4 is a vertical cross-sectional view taken along the arrow, FIG. 4 is a partially enlarged cross-sectional view showing an example of a mounting portion of a subject, FIG. 5 is a perspective view of an essential part of the second embodiment, and FIG. Perspective view,
FIG. 7 is a sectional view of an essential part of FIG. 1 ... Cassette cradle, 2 ... Guide, 2a ... Cassette receiving surface, 3 ... Detection swing lever, 5 ... Supporting tool, 7 ...
… Subject, 8 …… detector, 10 …… wafer cassette.

Claims (1)

[Scope of utility model registration request] 1. A pair of left and right guides standing upright on a cassette receiving stand at a predetermined interval, a pair of left and right cassette receiving surfaces provided along the inside of the pair of guides, and a bridge extending across the pair of left and right cassette receiving surfaces. A swinging lever for detection and a support tool having one end fixed and the other end being a free end, the free end supporting the central part of the swinging lever for detection, The movable lever can be swung in a vertical plane,
In addition, the wafer cassette is provided with a supporting tool that is vertically movable, a test object that is fixed to the center of the detection rocking lever, and a detector that detects the test object. A wafer cassette positioning detection device, which detects the presence of a wafer cassette by simultaneously pushing down both ends of a swing lever.