JPH0722493A - Object detecting sensor - Google Patents

Abstract

PURPOSE:To provide a sensor which detects the presence of an object regardless of the sizes without damaging the object by providing a signal outputting part and a detecting part, which detects the presence of the object, on the edges of the two arms of an L-shaped fixing material permitting the parts to face each other. CONSTITUTION:A signal outputting part 1 and a detecting part 2 which detects the presence of an object are provided by facing each other at the edges of the two arms of an L-shaped fixing material 3. For example, a light projecting type signal outputting part 1 and a light receiving type detecting part 2 are provided at the edges of the two arms of the L-shaped fixing material 3 permitting the parts to face each other so as to constitute an object detecting sensor 30. The sensor 30 is arranged on an object carrying plate 10 so as to position an object 4 to be detected at the top of the arm whereupon the light receiving type detecting part 2 is provided, and the presence of the object 4 is detected by the reaching and unreaching of an signal outputted from the outputting part 1 in response to the presence of the object 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an object detection sensor for detecting the presence or absence of an object such as a wafer carried by a wafer carrier in a semiconductor manufacturing apparatus.

[0002]

2. Description of the Related Art FIG. 4 is a structural explanatory view showing an example of a conventional object detection sensor. The conventional object detection sensor 30 includes a light projecting type sending section 1 for projecting light and a light receiving type detecting section for receiving a light beam 7 and converting the light beam 7 into an electric signal on both arm ends of the U-shaped mounting member 3A. 2 are installed facing each other. FIG. 5 is a structural explanatory view showing an example of a wafer transfer device in a vertical semiconductor manufacturing apparatus which is one of the conventional and one of the objects of the present invention, and FIG. 6 applies the conventional sensor shown in FIG. 4 to the apparatus shown in FIG. It is a structure explanatory view in the case of doing. Cassette loader 1
The cassette pedestal 16 of No. 1 is a lifting screw shaft 17
The lifting / lowering screw shaft 17 is rotated by driving the lifting / lowering motor 18 in accordance with a control signal output from the control device 28 by operating the operation unit 29 to move up and down. The cassette shelf 12 is located between the cassette loader 11 and the wafer transfer machine 13, and can accommodate the cassettes 20 loaded with the wafers 4 in multiple stages.

Further, the wafer transfer machine 13 includes a tweezer 32.
Is provided, and the elevating block 22 is screwed onto an elevating screw shaft 24 driven by an elevating motor 23. The wafer transfer machine 13
The turning mechanism and the like are omitted. Boat carrier 1
The lifting block 25 of No. 5 is screwed onto a lifting screw shaft 27 driven by a lifting motor 26. Further, the boat 14 is mounted on the lifting block 25 and has a mechanism capable of rotating the boat.

Cassette loader 11 and wafer transfer machine 1
3, each motor 18, 23, 2 of the boat transport mechanism 15, etc.
A limit sensor 30 is provided on the pillar 19 to limit the movement of
A _1, 30A _2, and limit sensor 30A ₃ to column 21,
30A ₄ on the pillar 31 and limit sensors 30A ₅ and 30A
₆ , the home sensor 30B ₁ is mounted on the pillar 19, the home sensor 30B ₂ is mounted on the pillar 21, and the home sensor 30B is mounted on the pillar 31 for positioning the motors 18, 23, 26.
Place ₃ , 30B ₄ . Flags 16A, 22A, 25A for limit and home for operating the limit sensor and the home sensor are attached to each of the elevators, that is, the cassette pedestal 16, and the elevator blocks 22 and 25. Further, normally, the object detection sensor 30 such as a limit or home sensor uses a U-shaped transmissive sensor as shown in FIG.

[0005]

In the above-mentioned conventional transmission type object detection sensor, even if the distance D between the light projecting type sending section 1 and the light receiving type detecting section 2 is variable, it is non-contact. Since the distance D is limited, the presence / absence detection of an object thicker than the distance D, in other words, the presence / absence detection of an object only if the object has a thickness capable of passing the distance D However, there is a problem that the sensor itself may come into contact with the surface of the object 4 to be detected and be damaged. When detecting the presence or absence of the wafer 4 to be transferred by the wafer transfer device shown in FIG. 5, the sensors 30A ₁ to 30A ₆ and 30B _{1 to} 30B ₄ are proportional to the number of the lifting motors 18, 23 and 26.
And since the number of flags 16A, 22A, 25A also increases,
There is also a problem that the number of parts and man-hours increase.

[0006]

In order to solve the above-mentioned problems, the sensor of the present invention has an L-shaped mounting member 3 as shown in FIG.
The sending unit 1 and the detecting unit 2 for detecting the presence or absence of the object 4 are respectively attached to the two arm ends so as to face each other. With such a configuration, the signal sent from the sending unit 1 does not reach or reaches the detection unit 2 depending on the presence or absence of the object 4, and the presence or absence of the object 4 can be detected.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1A and 1B are front and plan views, respectively, for explaining the structure of the essential parts of an embodiment of an object detection sensor of the present invention, and FIGS. It is a structure and action explanatory drawing of a present Example. 1 and 2, 3 is L
The shape-mounting materials 1 and 2 are a light-transmitting type transmitting section and a light-receiving type detecting section, respectively, which are attached to the ends of the two arms of the L-type mounting material 3 so as to face each other.
Constitutes the main part of. Reference numeral 5 designates a power source, and 6 designates a light-projecting side amplifier whose input side is connected to this power source 5, and the light-projecting type sending section 1 is connected to its output side. Reference numeral 9 is a light-receiving side amplifier connected to the light-receiving type detecting section 2 for receiving the light beam 7 outputted from the light-projecting type transmitting section 1, converting it into an electric signal and outputting it, and 8 is an object 4
It is a switching circuit which is closed by the output of the light-receiving side amplifier 9 when shielded by. The object detection sensor 30 according to the present invention is provided on the object transport plate 10 so that the object 4 to be detected is located above one arm of the L-shaped attachment material 3, for example, the arm provided with the light receiving type detection unit 2. Install.

In the above structure, the voltage of the power source 5 is input to the light-projecting side amplifier 6, and the output of the light-projecting-type sending section 1 is activated to send out the light beam 7. When the object 4 to be detected, for example, the wafer 4 is not present on the object carrying plate 10, the light beam 7 sent from the light-projecting type sending unit 1 is as shown in FIG.
As shown in (A), it reaches the light-receiving type detection unit 2 and is converted into an electric signal, and the electric signal is amplified by the light-receiving side amplifier 9 and input to the switching circuit 8, and the switch is turned off to turn off the detection signal. become. If the wafer 4 to be detected is present on the object transport plate 10, the light beam 7
Is not shielded by the wafer 4 and does not reach the light receiving type detector 2 as shown in FIGS. 1 (A), 1 (B) and 2 (B), and no electric signal is output from the light receiving side amplifier 9. No electric signal is output, there is no input to the switching circuit 8, and the switch is turned on to output a detection signal.

It can be easily understood that the object detection sensor 30 according to the present invention can be applied to the detection of the presence or absence of the wafer 4 transferred by the wafer transfer device shown in FIG. FIG. 3 is a structural explanatory view when the sensor of the present invention shown in FIGS. 1 and 2 is applied to the apparatus of FIG. FIG. 3 is a diagram corresponding to the conventional example shown in FIG. 6 described above, in which the object detection sensor 30 according to the present invention is replaced by a limit sensor 30A ₁
30A ₆ and home sensors 30B _{1 to} 30B ₄ are used. According to the present embodiment, since there is no obstruction above the arm of the L-shaped mounting member 3 provided with the light receiving type detection unit 2 and there is a large space, the size (thickness, length) of the wafer to be detected is detected. The width of the wafer 4 is not limited to the above, and the presence or absence of the wafer 4 of any size can be detected, and the sensor 4 does not contact the surface of the wafer 4 to be detected, so that the wafer 4 is damaged. There is no fear. Further, the object detection sensor 3 according to the present invention
When 0 is applied to the presence / absence detection of the wafer 4 transferred by the above-described wafer transfer device shown in FIG. 5, as is apparent from FIG.
25A or the like can be eliminated, and the number of parts and man-hours can be reduced. Further, since the light projecting type sending section 1 and the light receiving type detecting section 2 are respectively provided at the ends of the two arms of the L-shaped mounting member 3 to form an integrated type, the axis alignment of the light projecting type sending section 1 and the detecting section 2 is performed. Since it is unnecessary and stable object detection can be performed, reliability and economic efficiency can be improved.

In the present invention, it is obvious that the same effect can be obtained even if the light emitting type sending section 1 and the light receiving type detecting section 2 are mounted at opposite positions, and the detection signal of the light receiving type detecting section 2 is obtained. In contrast to the above, the detection signal may be obtained when the switch is opened and is not obtained when the switch is closed. The sensor according to the present invention can be used not only for detecting the presence / absence of the wafer 4 conveyed by the wafer conveying device in the semiconductor manufacturing apparatus shown in FIG. Needless to say, it can be used for detection of passage and presence / absence of automatic mail sorters such as letters.
Further, in the embodiment shown in FIG. 1, the sensor 30 according to the present invention is installed separately from the object carrying plate 10,
It may be provided integrally, or a plurality of sensors 30 may be arranged on both sides such as the base and the tip of the object transport plate 10 to make the object detection more reliable. Needless to say, the sending unit 1 and the detecting unit 2 are not limited to those using a light beam.

[0011]

As described above, according to the present invention, the L-shaped attachment member is provided with the sending portion and the detection portion for detecting the presence / absence of an object, which are respectively attached to the two arm end portions. Since there is no obstruction above one arm of the mounting member 3 and there is a large space, the size of the object 4 is not limited, and not only the size of the object 4 of any size can be used for detection of its presence. Since the sensor itself does not contact the surface of the object 4 to be detected, there is no possibility of damaging the object 4.

[Brief description of drawings]

1A and 1B are an explanatory front view and a plan view showing a configuration of a main part of an embodiment of an object detection sensor of the present invention, respectively.

FIG. 2A and FIG. 2B are explanatory diagrams of the configuration and operation of the present embodiment, respectively.

FIG. 3 is an explanatory view of the configuration when the sensor of the present invention shown in FIGS. 1 and 2 is applied to the device of FIG.

FIG. 4 is a configuration explanatory view showing an example of a conventional object detection sensor.

FIG. 5 is a structural explanatory view showing an example of a wafer transfer device in a vertical semiconductor manufacturing apparatus which is one of conventional and one of the objects of the present invention, and shows an example when a conventional sensor is applied.

6 is an explanatory diagram of a configuration when the conventional sensor shown in FIG. 4 is applied to the device shown in FIG.

[Explanation of symbols]

 1 (light emitting type) sending part 2 (light receiving type) detecting part 3 L-shaped mounting material 4 object (wafer) 30 object detecting sensor

Claims (1)

[Claims] 1. An object detection sensor in which a delivery section and a detection section for detecting the presence or absence of an object are attached to the two arm ends of an L-shaped mounting member so as to face each other.