JP2501329Y2 - Wafer transfer robot - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing apparatus, and more particularly to wafer transfer in a vacuum tube.

2. Description of the Related Art Conventionally, in this type of wafer transfer robot, a wafer detection sensor 1 is fixed to a wafer mounting stage 2 by a sensor fixing metal fitting 3, as shown in a parallel view in FIG. The wafer 4 is positioned by the positioning plate 5 and is mounted on the plate-shaped wafer mounting stage 2.

The wafer detection sensor 1 is an optical sensor that detects the presence or absence of the wafer 4 by the presence or absence of light shielding. When the presence of the wafer 4 is detected through the detection window 6, the robot arm 7 conveys the wafer 4 to a predetermined position.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention By the way, since the conventional wafer transfer robot described above has only one wafer detection sensor 1, the wafer 4 is raised to the positioning plate 5 or the wafer 4 is mounted on the wafer mounting stage. Even if the wafer slips on the wafer 2 and is not on the proper position on the wafer mounting stage 2, the wafer detection sensor 1 detects the wafer 4, and the wafer is transferred by the robot arm 7. Therefore, there is a disadvantage that the wafer 4 may not be stored in the cassette or may be broken, which may cause a transportation problem.

Means for Solving the ProblemsThe wafer transfer robot of the present invention has a sensor for detecting the presence of a wafer at a position corresponding to the central portion of the wafer on the wafer mounting stage with high sensitivity, and the wafer is positioned at the position corresponding to the outer peripheral portion of the wafer. It is characterized by arranging a low-sensitivity sensor that detects that the wafer mounting stage is in the normal position when it is in the normal position and does not detect it when it is floating by a predetermined size.

Operation In the above configuration, the central sensor detects the presence or absence of the wafer, and the outer peripheral sensor can accurately determine whether or not the wafer is in the normal position.

In other words, if the outer peripheral sensor determines that there is "no" even though the central sensor has detected that "there is",
It can also be detected when the wafer deviates from the position of the sensor and is largely displaced, or when the position is not so large and the wafer is lifted above a predetermined size from the wafer mounting stage.

Embodiment Hereinafter, the present invention will be described with reference to the drawings.

FIG. 1 is a plan view of a wafer transfer robot showing an embodiment of the present invention.

In the figure, 1a to 1e are optical sensor type wafer detection sensors that detect the presence or absence of the wafer 4 by the presence or absence of light shielding, 2 is a wafer mounting stage, 3 is a sensor fixing bracket, 4 is a wafer, 5 is a positioning plate, and 6 is A detection window, 7 is a robot arm.

 Next, the wafer transfer robot will be described.

The wafer detection sensor 1a is located at the center of the wafer on the wafer mounting stage 2 and the wafer detection sensors 1b, 1c, 1d, 1e
Is a sensor fixing bracket 3 inside the wafer from 2 to 3 mm
Has been fixed by. The sensitivity of the wafer detection sensor 1a is raised up to the point where it is not detected as being present without the wafer 4, and the sensitivity of the wafer detection sensors 1b to 1e is flat so that it will not be detected when the wafer 4 floats 2 to 3 mm. Is set to.

The wafer 4 placed in a flat attitude on the wafer mounting stage 2 is positioned by the positioning plate 5 and detected by the wafer detection sensor 1 through the detection window 6. The following table shows examples of combinations of ON / OFF of the wafer detection sensor 1 which is judged by the sensor 1a that the wafer 4 is present.

From the detection of wafer detection sensors 1a to 1e and their combination,
It can be determined that the wafer 4 is in the regular position on the wafer mounting stage 2, and the robot arm 7 transfers the wafer 4 to the next position without trouble.

Effect of the Invention As described above, the present invention can determine that the wafer is mounted at the regular position including that there is no large positional deviation on the wafer mounting stage and that the wafer is not lifted up. It is possible to eliminate troubles such as wafer displacement, wafer drop, and wafer cracking after the wafer is transferred to, and it is possible to improve the productivity by shortening the trouble recovery time.

[Brief description of drawings]

FIG. 1 is a plan view of a wafer transfer robot according to an embodiment of the present invention, and FIG. 2 is a plan view of a conventional wafer transfer robot. 1 ... Wafer detection sensor, 2 ... Wafer mounting stage, 3 ... Sensor fixing bracket, 4 ... Wafer, 5 ... Positioning plate, 6 ... Detection window, 7 ... Robot arm.

Claims (1)

(57) [Scope of utility model registration request] 1. A wafer transfer robot used in a vacuum tube, wherein a sensor for highly sensitively detecting the presence of a wafer is arranged at a position corresponding to a central portion of a wafer on a wafer mounting stage, and the wafer is positioned at a position corresponding to an outer peripheral portion of the wafer. A wafer transfer robot characterized by arranging a low-sensitivity sensor that reliably detects when the wafer mounting stage is in the normal position and does not detect it when it is floating by a predetermined size.