JPH0124669Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wafer counter for counting the number of wafers accommodated in a carrier cassette (hereinafter referred to as cassette).

Conventional wafer counter device, e.g. Application No. 58
-20144, 58.12.29, as shown in Figure 7, two rectangular flat plates 3b' that are moved up and down by a drive motor are installed side by side, and the space of the flat plates 3b' is horizontally moved in the direction of a to a'. A cassette 8 containing the wafers 7 is mounted on a flat plate 3b' with an optical sensor light receiving and emitting device that moves back and forth.
The wafers 7 housed in the cassette 8 are counted by placing the wafers 7 in the cassette 8 and moving the sensor receiving/emitting section 1'.

However, in this device, there is only one sensor receiving/emitting section, and the space a~ of the flat plate directly below the carrier.
Since a' is moved back and forth, the speed up of counting is limited.

The purpose of this invention is to shorten the counting time by providing a sensor receiving/emitting section corresponding to each wafer storage groove so that wafers can be counted without moving the sensor receiving/emitting section. be.

The present invention involves arranging a plurality of sensor light emitting/receiving sections 1 (hereinafter referred to as "receiving/emitting sections") in a line at regular intervals, and placing members having mutually corresponding wafer storage grooves on both sides sandwiching the sensor light emitting/receiving sections. At the same time, a space 12 is formed between the surface including the bottom surface of the wafer storage groove on both sides and the light receiving/emitting section.
By fixing the light receiving/emitting section and the above-mentioned member, it is possible to eliminate the need for reciprocating movement of the light receiving/emitting section and increase the counting speed of wafers in the cassette.

To explain the present invention with reference to an embodiment, as shown in FIG. 1, a plurality of light receiving and emitting sections 1 are arranged in a line at regular intervals, and members made of Teflon or Diflon are used to sandwich the light receiving and emitting sections 1 and correspond to the upper and lower sides. A side plate 3a is provided. Also, a case 4 and a side plate 3 containing a built-in sensor amplifier.
a, and a space 12 is provided between the surface including the bottom surface 11 of the wafer accommodating groove 2 and the head of the light emitting/receiving section 1. Fix the 4th class to each other. Furthermore, the side plate 3
A side plate 3a' is provided as a member corresponding to a, and a chuck function is provided on both side plates 3a, 3a'.

Now, as shown in FIG. 5, the wafer 7 housed in the carrier 8 is lifted up by the transfer lifting device, and the lifted wafer 7 is operated on both sides 3a and 3a' of the wafer counter shown in FIG. Then, the wafer is stored in the wafer storage groove 2 and held. Place the wafer on both side plates 3
When the wafers are gripped or chucked by the wafers a and 3a', the light emitting/receiving section 1 provided on the side plate 3a sequentially emits light into groups for the simultaneously chucked wafers. In order to avoid light interference with adjacent wafers, the light emitting method is a scanning method in which the wafers are divided into groups as shown in FIG. (See FIG. 6...Example when 25 light receiving/emitting sections are provided) When light is emitted, the amount of light received by the light receiving/emitting section 1 changes depending on the presence or absence of the wafer 7 accommodated in the wafer groove 2. By determining the status of this change using an identification device (not shown - known device) connected to the light receiving/emitting unit 1 via an amplifier and a connection cord 6, the presence or absence and number of wafers stored in each wafer storage groove 2 are measured. You can.

By using this device, not only does it become unnecessary to move the light receiving and emitting parts, but also the side plates 3a and 3
As the wafer is chucked by a', the distance l between the peripheral end face 11 of the chucked wafer 7 and the head of the light receiving/emitting section 1 is always constant, as shown in FIG. 3a and 3a' are completely engaged, and each wafer is parallel and equally spaced, so there is no need to push up the wafers using a wafer aligner or push-up plate when using a conventional wafer counter, increasing the speed of counting work. can be achieved. (Refer to Application No. 58-201044 Wafer Counter) Fig. 4 shows another embodiment of the member having a wafer groove, in which a plurality of light receiving and emitting parts 1 are provided in a row at equal intervals, and wafers corresponding to each other are placed on both sides of the member. As the above-mentioned member having the housing groove 2, a flat plate 3b made of Teflon or Diflon, which is connected to a lifting device and can move up and down, is arranged in parallel.

Further, the case 4 containing the light receiving/emitting section 1 and the sensor amplifier is fixed to the flat plate 3b.

Next, as shown in FIG.
is lightly pushed up using the flat plate 3b. As a result, the wafers 7, which had been accommodated in the wafer accommodation groove 2 in the carrier 8 at an angle, are straightened in the same way as shown in FIGS. 7 and 9, and the orientation flat of the wafers accommodated in the cassette is Part 10 is the measuring plate 3b
The wafers 7 are completely in close contact with the bottom of the wafer accommodating groove 2, and the distance l from the light receiving/emitting surface at the head of the light receiving/emitting section 1 provided directly below the wafer 7 is approximately the same.

Next, the light emitting/receiving section 1 sequentially emits light for each group in the same manner as in the embodiment shown in FIG. 1, so that the wafers accommodated in the carrier can be counted through the identification device.

This example is a conventional device (application number 58-201044)
The counting speed can be increased compared to the conventional device, and it can be manufactured by partially modifying the conventional device.

Since the present invention is as described above, it is possible to count wafers immediately after storing them in the wafer storage groove, without requiring the operation and time required to move the sensor light receiving and emitting part unlike the conventional device. The time required to count wafers can be reduced. Furthermore, since a space is provided between the surface including the bottom surface of the wafer storage groove and the light emitting/receiving section, the light from the light receiving/emitting section can be reflected by the periphery of the wafer and can be sensed by the light receiving/emitting section. At the same time, the measurement accuracy can be improved because there is no movement of the light receiving and emitting parts.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of an embodiment of the present invention, Fig. 2 is a sectional view taken along the - line in Fig. 1, and Fig. 3 is a - line sectional view in Fig. 2.
4 is a perspective view of a main part of another embodiment, FIG. 5 is a front view showing the usage state of FIG. 4, and FIG. 6 is a line diagram showing the operating state of each sensor light receiving section. FIG. 7 is a perspective view showing a conventional wafer counter in use, FIG. 8 is a cross-sectional view taken along the line - - in FIG.
The figure is a sectional view taken along the line -- in FIG. 8. 1...Sensor light receiving and emitting section, 2...Wafer storage groove,
11...A surface including the bottom surface of the wafer storage groove 2, 12...
. . . Space portion, 3a . . . Measurement plate to which the sensor receiving/emitting part is fixed, 3a' . . . Side plate corresponding to 3a, 3b .

Claims (1)

[Claims for Utility Model Registration] 1. A plurality of sensor receiving and emitting sections 1 are arranged in a line at regular intervals, and members having mutually corresponding wafer accommodating grooves 2 on both sides of the sensor receiving and emitting sections 1 are lined up. A wafer counter characterized in that a space 12 is provided between the surface including the bottom surface 11 of the wafer storage groove 2 and the head of the sensor receiving/emitting section 1. 2. The wafer counter according to claim 1, wherein the members having wafer storage grooves are a pair of movable side plates 3a, 3a' facing each other. 3. The wafer counter according to claim 1, wherein the member having the wafer storage groove 2 is a flat plate 3b that can be moved up and down.