JPH08250575A - Cassette detector - Google Patents

Abstract

PURPOSE: To provide the cassette detector, which can accurately detect the presence of a cassette in a semiconductor manufacturing apparatus. CONSTITUTION: In the cassette detector, wherein a detecting lever 11 is brought into contact with the bottom face of the cassette and displaced and a photosensor 3 is turned ON/OFF, the detecting lever is formed of a base-part plate spring 5 and a working part 6 in the approximately U shape, a shielding part 7 is provided at the tip of the working part and the base part is fixed through a support plate 14. The optical path of the photosensor can be shielded and opened by a shielding part. The point of force acting on the working part is located on the axial line of the plate spring part. The torsion at the tip part of the plate spring part does not occur. The displacement of the point of force at the working prat is accurately transmitted to the shielding part. The photosensor is securely turned ON/OFF by the shielding part, and the presence or absence of the cassette is detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cassette detecting device in a semiconductor manufacturing apparatus.

[0002]

2. Description of the Related Art In a semiconductor manufacturing apparatus, a required number of substrates to be processed such as wafers and glass substrates are loaded in a cassette and the semiconductor manufacturing apparatus and an external transfer device are handled. Further, it is important to confirm whether or not the cassettes are transferred and received surely, and whether or not the device normally functions, and it greatly affects the improvement of the operating rate. Therefore, a cassette detection device for detecting a cassette is provided on the cassette transfer stage.

A conventional cassette detecting device will be described with reference to FIGS. FIG. 3 shows the outline of the cassette stage, and FIG. 4 shows the main part of the cassette detection device of the cassette stage.

The cassette receiving substrate 1 is notched at its central portion in a substantially T-shape so as not to interfere with other constituent members, and cassette detecting devices 2 are provided on both sides of the notched portion 10. ing. The cassette detecting device 2 is mainly a transmissive photosensor 3 provided on the lower surface of the cassette receiving substrate 1, and a sensing lever for mechanically detecting the presence or absence of a cassette provided on the lower surface of the cassette receiving substrate 1. It consists of four.

The sensing lever 4 includes a leaf spring portion 5 and an action portion 6 which is bent up by 90 ° at the tip of the leaf spring portion 5 and extends at right angles to the longitudinal direction of the leaf spring portion 5 and in the horizontal direction. ,
The leaf spring portion 5 has a shield portion 7 folded down 90 ° at the tip end thereof and extending parallel to the longitudinal direction. It is fixed by screws 8 at the base end. The action part 6
Is projected from the slit 9 formed in the cassette receiving substrate 1 to the upper surface of the cassette receiving substrate 1, and the shielding portion 7 blocks the optical path of the photosensor 3.

When a cassette (not shown) is placed on the cassette receiving substrate 1, the cassette is placed on the operating portion 6, and the projection formed on the lower surface of the cassette pushes the operating portion 6 downward. . When the acting portion 6 is lowered, the shielding portion 7 is displaced downward, and the shielding portion 7 is deviated from the optical path of the photosensor 3. The photo sensor 3 detects the light and detects the presence of the cassette. When the cassette is removed, the leaf spring portion 5 is restored and the optical path of the photo sensor 3 is blocked by the shielding portion 7, and the photo sensor 3 confirms the absence of the cassette.

Then, the cassette detecting device 2 confirms whether or not the cassette is received on the cassette receiving substrate 1.

[0008]

However, in the cassette detecting device 2, the action portion 6 extends in the direction perpendicular to the leaf spring portion 5 and the action point (force point) is eccentric with respect to the axis of the leaf spring portion 5. Therefore, a twisting moment is generated, and the vertical displacement acting on the acting portion 6 is not accurately transmitted to the shielding portion 7. Therefore, false detection may occur.

In view of the above situation, the present invention intends to provide a cassette detecting device capable of accurately detecting the presence of a cassette.

[0010]

According to the present invention, the sensing lever is brought into contact with the bottom surface of the cassette to be displaced and the photosensor is turned on.
In a cassette detection device for turning on / off, the sensing lever is formed in a substantially U shape by a base plate spring part and an action part, a shield part is provided at the tip of the action part, and the base part is fixed via a support plate. However, the optical path of the photosensor can be blocked and released by the shielding portion.

[0011]

The force point acting on the acting portion is on the axis of the leaf spring portion, the displacement of the acting portion force point is accurately transmitted to the shielding portion without any twist at the tip of the leaf spring portion, and The photo sensor is surely turned on / off to detect the presence or absence of the cassette.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In this embodiment, the shape of the sensing lever is improved,
The reliability of the cassette detection device is improved, and the same parts as those shown in FIGS. 3 and 4 in FIGS. 1 and 2 are designated by the same reference numerals.

A photo sensor 3 and a sensing lever 11 are provided on the lower surface of the cassette receiving substrate 1 and on both sides of the notch 10.

The sensing lever 11 has a base portion 12 and a tip portion 13.
Is connected to the leaf spring portion 5 in a generally U-shape, and the tip of the tip portion 13 is further bent up by 90 °, and is perpendicular to the longitudinal direction of the leaf spring portion 5 and in the horizontal direction. And a shield portion 7 which is folded down 90 ° at the width end of the tip portion 13 and extends parallel to the longitudinal direction of the leaf spring portion 5. It projects from the upper surface of the cassette receiving substrate 1, and the shielding portion 7 blocks the optical path of the photosensor 3.

A support plate 14 having the same shape as the base portion 12 is superposed on the base portion 12 of the sensing lever 11, and the base portion 12 is attached to the cassette receiving substrate 1 and the support plate 14.
It is fixed by screws 8 while being held by.

The operation will be described below.

When a cassette (not shown) is placed on the cassette receiving substrate 1, the projection formed on the lower surface of the cassette is placed on the upper side of the operating portion 6 and pushes the operating portion 6 downward. . The action point on the action portion 6 is the leaf spring portion 5
The support plate 14 is on the axis of
Since it has the same shape as the above, the fulcrum of the sensing lever 11 for the action of the load on the action portion 6 is the base end of the leaf spring portion 5.

Thus, no twist occurs at the tip of the leaf spring portion 5, and the vertical displacement at the point of action of the operating portion 6 becomes the vertical displacement of the shielding portion 7 as it is.
The photo sensor 3 is surely turned on / off, and the cassette detecting device 2 surely detects whether or not the cassette is received on the cassette receiving substrate 1.

The shape of the support plate 14 is as follows.
Even if the shape is not the same as that of the base portion 12, the sensing lever 11 may be held so that the displacement of the base end of the leaf spring portion 5 becomes 0, and at least the end face of the support plate 14 crosses the base end of the leaf spring portion 5. Any shape will do. Further, in the above-mentioned embodiment, the optical path of the photosensor is blocked by the sensing lever when the cassette is mounted, but the sensing lever may be deviated from the optical path of the photosensor when the cassette is mounted.

[0021]

As described above, according to the present invention, the cassette detection accuracy of the cassette detection device is improved, the reliability of the semiconductor manufacturing apparatus is improved, and the operation rate is improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing an outline of a cassette stage equipped with a cassette detection device according to the present invention.

FIG. 2 is a perspective view showing a main part of an embodiment of the present invention.

FIG. 3 is a perspective view showing an outline of a cassette stage including a cassette detection device according to a conventional example.

FIG. 4 is a perspective view showing a main part of a conventional example.

[Explanation of symbols]

 1 cassette receiving substrate 2 cassette detecting device 5 leaf spring part 6 acting part 7 shielding part 8 screw 11 sensing lever 14 support plate

Claims (1)

[Claims] 1. In a cassette detecting device, wherein a sensing lever comes into contact with a bottom surface of a cassette and is displaced to turn on / off a photo sensor, the sensing lever is formed into a substantially U shape by a base plate spring portion and an acting portion. A cassette detecting device, characterized in that it is formed, a shielding portion is provided at a tip of an action portion, the base portion is fixed via a support plate, and an optical path of a photosensor can be blocked and released by the shielding portion.