JPH0533247Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention is a position where an object to be processed or inspected (work) or parts (hereinafter referred to as parts) can be supported and rotated accurately by a certain angle. This invention relates to a transport arm with a delivery mechanism.

(Prior Art) There is a need to preserve the angular alignment of parts such as semiconductor wafers and then rotate them accurately, for example, by 180° for the next process.

A pulse motor is used in the positioning mechanism of a device that transports such parts through 180 degrees of rotation.

That is, a pulse motor performs high-resolution driving, but in order to improve the resolution by gearing down and further improving the resolution, a method can be considered in which an encoder is installed and the signal is fed back.

(Problem to be solved by the invention) Although the above-mentioned configuration allows for highly accurate 180° rotational conveyance, there are problems in that the system is complex and costly.

An object of the present invention is to provide a transfer arm with a positioning mechanism that can accurately transfer a device that accurately transfers parts and the like through rotational movement at a constant angle using a simple mechanism.

(Means for Solving the Problems) In order to achieve the above object, a transfer arm having a positioning mechanism according to the present invention is a transfer arm that transfers a part whose one side is flat by rotating it at a certain angle from an initial position. A rotary conveyance arm is provided with a holding part and a cam driven part, a motor that rotates the rotary conveyance arm at a slightly greater angle than a certain angle, and a motor that rotates the conveyor arm driven at a slightly larger angle than a constant angle. It consists of an eccentric cam that pushes back by a certain amount and retracts.

(Example) The present invention will be explained in more detail with reference to the drawings and the like.

FIG. 1 is a perspective view showing an embodiment of a transport arm having a positioning mechanism according to the present invention.

FIG. 2 is a plan view of the arrangement.

The rotary transfer arm 1 is connected to an arm drive shaft 11 that is connected to the output shaft of a pulse motor 10 so that there is no play in the rotational direction.

The plate-shaped rotary transfer arm 1 has a shape symmetrical to the rotation center axis of the arm drive shaft 11, and is provided with semicircular wafer holding portions at both ends.

Semiconductor wafer suction grooves 2a and 2b are provided in this semicircular portion, respectively, and are connected to a negative pressure supply source (not shown) via an air passage provided inside the plate.

Furthermore, cam driven rollers 3a and 3b are provided on the abdomen of the rotary transfer arm 1 on the opening side of the semicircular wafer holding portion, respectively.

These cam driven rollers 3a, 3b are rotationally symmetrical with respect to the arm drive shaft 11.

A grooved cam cylinder 7 having a cam groove 7a is fixed in parallel to the arm drive shaft 11, and the cam groove 7a guides a pin 15 of a shaft 14 having an eccentric cam 9. The output shaft 13 of the air cylinder 5 is connected to the pin 15
are connected to.

When the shaft 14 is pushed up by the air cylinder 5, the eccentric cam 9 rises while rotating counterclockwise in the figure.

Initially, the rotary transfer arm 1 is at the origin position S shown by the broken line, and from there the pulse motor 1
0, the gripping position A, B with the semiconductor wafer
Rotate 90° + α° (α: minute angle) toward .

At this time, the eccentric cam 9 is initially below the position of the cam driven roller 3b, and when the rotary conveyance arm 1 reaches the position B, the eccentric cam 9 is pushed upward by the air cylinder 5 and approaches the cam driven roller 3b.

The eccentric cam 9 rises while rotating and the roller 3b
At this time, the roller 3b is pushed by the rotational force, and the rotary transfer arm 1 is pushed back by α° (a minute angle) to position it at the holding positions A and B, and after the wafer is held, it descends and avoids it.

The rollers and eccentric cams are machined with high precision to ensure accurate mechanical positioning.

(Effects of the invention) As explained in detail above, the transport arm with the positioning mechanism according to the present invention has a positioning mechanism that rotationally transports the part whose one side is flat from the initial position at a certain angle. A rotary conveyance arm is provided with a holding part and a cam driven part, a motor that rotates the rotary conveyance arm at a slightly greater angle than a certain angle, and a motor that rotates the conveyor arm driven at a slightly larger angle than a constant angle. It consists of an eccentric cam that pushes back by a certain amount and retracts.

Therefore, by combining a direct-acting cylinder, a rotary cam, etc., it is possible to achieve highly accurate positioning with a simple mechanism, and to reduce costs.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of a transport arm having a positioning mechanism according to the present invention. FIG. 2 is a plan layout view of a 180° semiconductor wafer transfer apparatus using a transfer arm having the positioning mechanism according to the present invention. DESCRIPTION OF SYMBOLS 1... Rotating transfer arm, 2a, 2b... Semiconductor wafer suction groove, 3a, 3b... Cam driven roller, 5... Air cylinder, 7... Groove cam tube, 9...
... Eccentric cam, 10 ... Pulse motor, 11 ... Arm drive shaft, 13 ... Cylinder shaft, 14 ... Cam shaft, 15 ... Cam pin.

Claims (1)

[Scope of utility model registration request] In a transfer arm that rotates and transfers a part whose one side is flat from an initial position at a certain angle, the rotary transfer arm is provided with a holding part for parts, etc. and a cam driven part, and the rotary transfer arm is rotated at a angle slightly less than a certain angle. 1. A transport arm having a positioning mechanism, comprising: a motor that rotates at a large angle; and an eccentric cam that pushes the transport arm, which has been driven at a slightly large angle, back to a predetermined position and retreats.