JP4055200B2 - Fork for substrate transfer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fork for carrying a substrate equipped with a sensor for detecting a substrate existing on the fork regardless of the material of the substrate, a surface condition or an atmosphere around an apparatus. <P>SOLUTION: In the fork 1 for carrying a substrate where substrate supporting pins 12 are arranged on a planar body 11 and a substrate 13 is mounted on the substrate supporting pins 12, a stress impedance element 22 is provided in the substrate supporting pin 12 in order to detect the load of the substrate 13 applied to the substrate supporting pin 12 thus detecting the presence of the substrate 13. <P>COPYRIGHT: (C)2003,JPO

Description

【００１２】
表１に示すように、第１および第２の実施例はいずれの場合も誤動作がなかった 。一方、光透過型は石英ガラス基板で、光反射型は窒化膜付基板で、静電容量型は水滴付着実験でそれぞれ誤作動が認められた。
【００１３】
【発明の効果】
以上述べたように、本発明の基板搬送用フォークは、基板支持ピンに内蔵された応力インピーダンス素子で基板の荷重を検出するので、フォークと基板の接触面積は従来と変わらず、基板の材質、基板の表面状態、水滴や異物の有無に影響されることなく、基板の有無を確実に検出することができる効果がある。
【図面の簡単な説明】
【図１】本発明の第１の実施例を示す基板搬送用フォークの斜視図である。
【図２】本発明の第１の実施例を示す基板支持ピンの内部構造図である。
【符号の説明】
１：基板搬送用フォーク、１１：本体、１２：基板支持ピン、１３：基板、
２１：弾性体、 ２２：応力インピーダンス素子、２３：回路基板、
２４，２５：電極、２６，２７：リード線[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a substrate transport fork that is mounted on a robot for transporting a silicon wafer, a liquid crystal substrate or the like (hereinafter simply referred to as a substrate) and places the substrate or the like in a manufacturing process of a semiconductor or a liquid crystal substrate.
[0002]
[Prior art]
Conventionally, in a manufacturing process of a semiconductor or a liquid crystal substrate, a silicon or liquid crystal substrate is transferred between various processing apparatuses using a transfer robot.
In this type of transfer robot, it is necessary to detect the presence or absence of a substrate on the transfer fork in order to prevent malfunction during transfer. In addition, it is necessary to detect the presence or absence of the substrate in a non-contact manner in order to prevent damage to the substrate and adhesion of foreign matter.
Therefore, in the conventional transfer robot, the presence / absence of the substrate is detected by a light transmission type, light reflection type or capacitance type sensor installed on the substrate transfer fork.
[0003]
[Problems to be solved by the invention]
However, in the semiconductor or liquid crystal substrate manufacturing process, substrates with different materials and surface conditions may be mixed and transported by the same transport robot. Depending on the type of substrate, the presence or absence of the substrate may be detected by conventional sensors. There was a problem that I could not. That is, since a transparent body such as a glass substrate transmits light as it is, it cannot be detected by a light transmission type sensor. In addition, since a silicon substrate having a nitride film formed on the surface absorbs light, it may not be detected by a light reflection type sensor. In addition, when a water droplet or a foreign substance adheres to the surface of the substrate, there is a problem that the capacitive sensor may malfunction.
In addition, the capacitance type sensor requires a certain area for substrate detection, and the detectable distance is as short as about 1 mm, so that there is a problem that the degree of freedom in designing a fork for transport is limited. .
If the load on the substrate is detected by a strain gauge or a giant magnetostrictive element, the above-mentioned problems will not occur. However, the strain gauge has a low gauge factor, and the sensitivity is insufficient for detecting the load on the substrate. Since a detection coil is required around the element, it is difficult to reduce the size, and there is a problem that it is easily affected by surrounding magnetic noise.
Accordingly, an object of the present invention is to provide a substrate transport fork provided with a sensor capable of detecting the presence or absence of a substrate on the substrate transport fork without being affected by the material, surface state or atmosphere around the apparatus. To do.
[0004]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the invention of claim 1 is directed to a substrate-conveying fork in which a substrate support pin is disposed on a flat plate-like main body and a substrate is placed on the substrate support pin. Inside the substrate support pins made of rubber, an amorphous wire and a circuit board are provided, and the amorphous wire has one end protruding from the circuit board and heading toward the apex of the cone along the cone axis. A change in impedance at both ends of the amorphous wire when the substrate load is applied to the substrate support pins when a high frequency current is supplied from the electrodes by being bonded to the substrate and connected to the electrodes at the upper and lower ends of the circuit substrate. To detect the presence or absence of the substrate.
According to a second aspect of the present invention, there is provided a substrate transfer fork in which a substrate support pin is disposed on a flat plate-like main body, and the substrate is placed on the substrate support pin. A copper wire plated with a Ni—Fe alloy and a circuit board, the copper wire extending along the axis of the cone so that one end of the copper wire protrudes from the circuit board toward the apex of the cone. Are attached to the circuit board and connected to electrodes at the upper and lower ends of the circuit board, and a high-frequency current is supplied from the electrode, and when a load on the board is applied to the board support pins, both ends of the copper wire are The presence or absence of the substrate is detected by detecting a change in impedance.
According to a third aspect of the present invention, there is provided a transfer robot provided with the substrate transfer fork according to the first or second aspect.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a substrate carrying fork 1 according to a first embodiment of the present invention. In the figure, reference numeral 11 denotes a main body of the substrate carrying fork 1. As the name of the fork, the main body 11 is a flat plate having a forked end. Three substrate support pins 12 made of conical rubber are disposed on the upper surface of the main body 11. One of the three substrate support pins 12 is provided with a stress impedance element to be described later. Reference numeral 13 denotes a substrate, which is supported by substrate support pins 12. Although not shown, the body 11 may be provided with a clamp or a suction device for fixing the substrate 13.
[0006]
FIG. 2 is an internal configuration diagram of the substrate support pins showing the first embodiment of the present invention. The substrate support pin 12 includes a stress impedance element 22 inside a conical rubber elastic body 21. The stress impedance element 22 is a Co—Si—B amorphous wire having a diameter of 30 μm, and is bonded to the circuit board 23 with one end protruding from the circuit board 23. The stress impedance element 22 is soldered to copper electrodes 24 and 25 in the vicinity of the upper and lower ends of the circuit board 23. Lead wires 26 and 27 are connected to the electrodes 24 and 25, and the lead wires 26 and 27 are not shown. The amplifier circuit and the power supply circuit are connected.
[0007]
The stress impedance element was found by Toshio Mohri et al. (Detailed in IEEE Trans. Magn., 33, p3355, 1997, or JP-A-10-170355) and subjected to special heat treatment. When stress is applied to the wire while high-frequency current is applied to both ends of the applied amorphous wire, the magnetization vector of the wire surface layer changes due to the magnetostrictive effect, so that the impedance at both ends of the wire changes. Yes, the gauge factor is 1200 or more. In addition, since the inventors of the present application have found that the same stress impedance effect as that of the amorphous wire can be obtained by a wire in which a material having magnetostriction is plated on the outer periphery of a core portion made of a conductive material (Japanese Patent Application No. 2001-218771), the stress impedance element 22 may be replaced with an amorphous wire, and a wire in which a material having magnetostriction is plated on the outer periphery of a core portion made of a conductive material may be used.
[0008]
When the substrate 13 is placed on the substrate transport fork 1, there are three substrate support pins 12, and therefore, approximately one third of the load of the substrate 13 is applied to each substrate support pin 12.
Since the substrate support / support pin 12 including the stress impedance element 22 is elastically deformed by a load applied by the substrate, the embedded stress impedance element 22 is also distorted. At this time, a high-frequency current is supplied from the power supply circuit to the stress impedance element 22, and the impedance between the electrodes 24 and 25 of the stress impedance element 22 changes due to strain due to the load of the substrate 13. When the amount of change in impedance exceeds a preset threshold value, a substrate detection signal is output. When transporting different types of substrates, the threshold for substrate detection may be set based on the lightest substrate.
[0009]
Next, a second embodiment of the present invention will be described. In this second embodiment, instead of the amorphous wire used in the first embodiment, the stress impedance element 22 is plated with a Ni—Fe alloy with a thickness of about 5 μm around a copper wire having a diameter of 80 μm. It is a thing.
[0010]
Table 1 shows a result of an experiment comparing the effects of the substrate transfer forks of the first and second embodiments of the present invention with those of a substrate transfer fork equipped with a conventional sensor. The experiment was conducted using the first embodiment, the second embodiment, a fork with a light transmission type sensor, a fork with a light reflection type sensor, and a fork with a capacitance type sensor. Check for malfunctions when trying to detect untreated silicon substrates, silicon substrates with a nitride film of approximately 800 nm on the surface, and quartz glass substrates, and malfunctions when water droplets are attached to the fork by spraying. It is to confirm.
[0011]
[Table 1]

[0012]
As shown in Table 1, the first and second examples did not malfunction in either case. On the other hand, the light transmission type was a quartz glass substrate, the light reflection type was a substrate with a nitride film, and the capacitance type was found to malfunction in a water droplet adhesion experiment.
[0013]
【The invention's effect】
As described above, the substrate transport fork of the present invention detects the load of the substrate with the stress impedance element built in the substrate support pin, so the contact area between the fork and the substrate is the same as before, the material of the substrate, There is an effect that the presence / absence of the substrate can be reliably detected without being affected by the surface state of the substrate, the presence / absence of water droplets or foreign matter.
[Brief description of the drawings]
FIG. 1 is a perspective view of a substrate carrying fork showing a first embodiment of the present invention.
FIG. 2 is an internal structural view of a substrate support pin showing a first embodiment of the present invention.
[Explanation of symbols]
1: substrate transport fork, 11: main body, 12: substrate support pin, 13: substrate
21: Elastic body, 22: Stress impedance element, 23: Circuit board,
24, 25: electrodes, 26, 27: lead wires

Claims (3)

In the substrate transport fork in which the substrate support pins are disposed on the flat plate-like main body and the substrate is placed on the substrate support pins.
Inside the substrate support pin made of conical rubber, an amorphous wire and a circuit board are provided,
The amorphous wire is bonded to the circuit board along the axis of the cone so that one end of the amorphous wire protrudes from the circuit board toward the apex of the cone, and is connected to the electrode at the upper and lower ends of the circuit board. High frequency current is supplied from
A substrate transport fork for detecting the presence or absence of the substrate by detecting a change in impedance at both ends of the amorphous wire when a load of the substrate is applied to the substrate support pin. In the substrate transport fork in which the substrate support pins are disposed on the flat plate-like main body and the substrate is placed on the substrate support pins.
In the inside of the substrate support pin made of conical rubber, a copper wire having a Ni-Fe alloy plated around and a circuit board are provided,
The copper wire is bonded to the circuit board along an axis of the cone so that one end of the copper wire protrudes from the circuit board toward the apex of the cone, and is connected to the electrode at the upper and lower ends of the circuit board. High frequency current is supplied from
A substrate fork for detecting a presence or absence of the substrate by detecting a change in impedance at both ends of the copper wire when a load of the substrate is applied to the substrate support pin.   3. A transport robot comprising the substrate transport fork according to claim 1.

Images