JPH023434Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a positioning device for accurately positioning and stopping a conveyed object at a predetermined position in an automatic conveyance device.

Conventionally, accurately positioning and stopping a conveyed object at a predetermined position in a conveyance system of an automatic conveyance apparatus has been an important issue for automating production processes and improving yield. For example, an automatic processing apparatus for semiconductor substrates as shown in FIG. 1 includes a support 1 fixed on a belt 2 stretched between pulleys 3, an elevator 7 connected to the support 1, and The semiconductor cassette 11 placed on the loader 14 is transported by a transport device (not shown) to the starting position X ₀ of the automatic processing device;
The cassette 11 is lifted up by the arm 9 at the _position
The cassette 11 is transported to a position (hereinafter referred to as a stop position) X ₁ where the center of the cassette 11 is located, and the cassette 11 is inserted into the processing liquid 15 by lowering the arm 9 at this position X ₁ and the cassette 11 is processed. liquid 1
By dipping the cassette 11 in 5 for a predetermined time,
A chemical surface treatment is applied to the semiconductor substrate 12 held within the cassette 12, and the immersion treatment is then repeated one after another.Finally, the cassette 11 is placed on the unloader 19 and transported to the next step.

Although FIG. 2 shows an enlarged view of the positioning device of the automatic processing apparatus shown in FIG. 1, a part of FIG. 1 is omitted for easy understanding. Third
The figure is a partially enlarged view showing another conventional device, but like FIG. 2, some parts are omitted. Third
The figure shows a stop photo sensor 4 at a predetermined position (Xi, i=0.1...) of the frame 6 disposed on the belt 2.
Fig. 2 shows the positioning device shown in Fig. 3 with a deceleration photo sensor 4-.
1 and 4-2 are attached to the front and rear of each stop photo sensor 4 at an equal distance, for example, 50 mm apart.

In the conventional positioning device shown in FIG. 3, when the light shielding plate 5 protruding from the support 1 conveyed in the direction of the arrow passes the photo sensor 4 position,
The movement of the support 1 is stopped by driving a braking device (not shown), but the response time of the photo sensor 4 and the sequencer (not shown) depends on the movement speed of the support 1 and its inertia. It slightly overruns and stops from a predetermined position (Xi, i=0, 1, 2...). Further, this overrun amount x is not constant depending on the moving direction of the support 1. In the conventional positioning device shown in FIG. 2, deceleration photo sensors 4-1 and 4-2 are provided, and a light shielding plate 5
As it moves, first the deceleration photo sensor 4
-1, the speed is decelerated to a predetermined speed, and then the brake is applied when the light shielding plate 5 blocks light from the photo sensor 4, so there is a problem that the vehicle stops before the predetermined stop position Xi. Ta.
In this way, in the conventional apparatus, a slight deviation always occurs when stopping the conveyed object at a predetermined position, and in particular, in an automatic processing apparatus like the one shown in the first figure, which conveys the object in two contradictory directions, depending on the direction of movement. Since the magnitude of the deviation is different, it has been difficult to accurately position and stop at a predetermined stop position in either of the opposing moving directions.

In addition, in the above-mentioned automatic processing process of semiconductor substrates, the size of semiconductor substrates has increased from 4" to 5" in recent years.
As the diameter increases from 5" to 6", there is a need to further improve the accuracy of conveyance positioning in the processing process. In other words, as the size of semiconductor substrates increases, the size of the production equipment itself increases, but since increasing the size of the production equipment itself comes with a disadvantage in production efficiency, it is advantageous to keep it as compact as possible and improve transfer positioning accuracy. That's why.

Therefore, as shown in an enlarged view in FIG. 4, as the diameter of the semiconductor substrate 12 increases, the distance between the cassette 11 and the tank wall 10 of the processing liquid tank 15 becomes narrower.
Accurate positioning of the cassette 11 is required so that the arm 9 does not come into contact with the tank wall 10 during movement of the arm 9.

Furthermore, if the cassette 11 is not accurately positioned at the center of the processing liquid tank 15, the circulation of the processing liquid to the semiconductor substrates 12 housed in the cassette 11 will be uneven, so that uniform chemical processing cannot be performed on the semiconductor substrates. The problem also arises that it cannot be applied to

This invention was devised in view of the above-mentioned current situation in order to solve various problems in conventional devices, and its first purpose is to accurately position and stop the conveyed object at a predetermined position in the conveyance system. The objective is to improve positioning accuracy. The second purpose of this invention is to simplify the structure of the positioning device. Other objects and advantages of this invention will become clear from the following description of the embodiments.

Next, an embodiment of the positioning device according to this invention will be described based on the accompanying drawings. FIG. 5 is a schematic diagram showing the main components of the positioning device of this invention, and like FIGS. 2 and 3, some parts are omitted to facilitate understanding of this invention. . In the figure, the photo sensors 4-1 and 4-2 are separated by distances l ₁ and l ₂ before and after a predetermined stop position Xi in the conveyance direction, and are set as a pair at predetermined positions Pi,
It is located at Pi′. The sensor installation position Pi is
When transporting objects such as the cassette 11 in the direction of arrow A, the end position Pr of the light-shielding plate 5-1 protruding from the end of the support 1 is lower than when the center of the support 1 reaches the predetermined position Xi. They are arranged shifted by a distance lr ₁ in the direction of arrow B. This distance lr ₁ is predetermined based on the inertia of the support 1, the elevator 7 and the arm 9 when the cassette 11 is not held, the transport speed, the response time of the electric circuit, the characteristics of the braking means, etc. In addition, the sensor arrangement position Pi' is reversely located at the cassette 11.
When transporting a conveyed object such as in the direction of arrow B, the position of the arrow B is lower than the end position Pr' of the light shielding plate 5-2 protruding from the end of the support 1 when the center of the support 1 reaches the predetermined position Xi. They are arranged shifted by a distance lr ₂ in the A direction. This distance _lr2 is predetermined based on the inertia in the state in which the cassette 11 is held, the conveyance speed, the response time of the electric circuit, the characteristics of the braking means, etc. In the automatic processing apparatus shown in FIG. 1, it is normal to hold and transport the cassette 11 in the direction of arrow B, and move the arm 9 back and forth in the direction of arrow A without holding the cassette. Therefore, the distances lr ₁ and lr ₂ differ depending on the direction of movement. Therefore, the overrun amount of support 1
lr ₁ and lr ₂ are determined in advance by calculation or actual measurement, and if the distance between both ends of the light shielding plates 5-1 and 5-2 is L, then
Installation position Pi of each photo sensor 4-1, 4-2,
Pi′ is l ₁ = L/2−lr ₁ and l ₂ = L/ respectively from the stop position Xi.
2-lr ₂ distance apart.

In the embodiment shown in FIG.
(see Fig. 1) is controlled by the control device 22 (see Fig. 1) based on electrical signals from each photo sensor 4-1, 4-2. This will be explained with reference to.

In FIG. 6, for example, when the support 1 is conveyed in the direction of arrow B, when the light shielding plate 5-2 protruding from the support 1 passes the photo sensor 4-1, the photo sensor 4-1 The speed was controlled by the control device 22 based on the electric signal from the controller 22 (Fig. 6 b○), and both the light shielding plates 5-1 and 5-2 shielded the photo sensors 4-1 and 4-2 from light. At this time, the motor 21 is similarly stopped by the control device 22 (FIG. 6 c). The support 1 stops at a point where it has moved in the conveying direction by a specific overrun distance lr ₂ at reduced speed. At this time, as mentioned above, since the photo sensor 4-2 is previously positioned on the front side by lr ₂ , the center of the support 1 (i.e., the holding position of the cassette 11) is at the predetermined position Xi.
It will be positioned and stopped. After performing the processing operation at a predetermined stop position Xi, the support 1
is moved again (Fig. 6, d○), and the next step is carried out (Fig. 6, e○).

In the above embodiment, the photo sensor 4-
When a signal from either one of photo sensors 4-1 or 4-2 is input to the control device 22, the conveyance speed is decelerated, and when signals from both photo sensors 4-1 or 4-2 are input to the control device 22. Since braking is applied, the width W (see FIG. 5) of each of the light shielding plates 5-1 and 5-2 is appropriately selected. At a predetermined stop position Xi, the cassette 11 is held by the arm 9 as shown in FIGS. 1 and 4,
When performing operations such as going up and down, the detection signals from photo sensors 4-1 and 4-2 are both
If it is ON, it can be confirmed that the arm 9 is accurately in the predetermined position.

Further, the control operation when the support body 1 is conveyed in the direction of arrow A is completely opposite to the case described above, so a description thereof will be omitted.

In the embodiment shown in FIG. 5, the pair of photo sensors 4-1 and 4-2 are connected to the end positions Pr and Pr of the light shielding plates 5-1 and 5-2 at the position Xi where the support 1 should stop. ', the motor 21 is braked by an overrun amount lr ₁ , lr ₂ , which is shifted in the opposite direction to the conveying direction. However, this invention is not limited to the above embodiment; for example, the positions of the photo sensors 4-1 and 4-2 are fixed, and the end positions of the light shielding plates 5-1 and 5-2 are Distances lr ₁ and lr ₂ from −1 and 4-2, respectively
It may also be provided so as to protrude and be shifted in the conveyance direction. Alternatively, instead of using the two light shielding plates 5-1 and 5-2, one light shielding plate extending from Pr to Pr' may be used. Furthermore, the photo sensor 4- is mounted on the support 1 itself without using the light shielding plates 5-1 and 5-2.
1 and 4-2 may be shielded from light, and these photo sensors may be arranged in the opposite direction to the conveyance direction by lr ₁ and lr ₂ from both ends of the support 1, and such a modification is within the scope of the present invention. It is clear that it belongs to .

In the above-mentioned embodiment, a photo sensor is used as a means for detecting the position of the support body 1, but as a detecting means, it is possible to use any method that can sense the position of the conveyed object, for example, a magnet. Needless to say, any known means such as a switch may be used.

Since the positioning device according to this invention is configured as described above, it has the following effects. (i) The moving body of the automatic transport device can be stopped at a predetermined stop position more accurately than before,
Positioning accuracy can be improved. (ii) Since the number of sensors is small, the number of input points to a control device such as a sequencer is reduced, and manufacturing is possible at low cost and easily. (iii) Positioning can be easily adjusted by simply changing the mounting position of the sensor or light shielding plate. (iv) Compared to conventional devices, instability in position accuracy due to left and right movement is eliminated. (v) It can be used not only for linear movement of a moving object, but also for positioning in curved movement, rotation, etc.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing the configuration of a conventional automatic processing device, Fig. 2 is a partial schematic diagram showing a conventional positioning device, Fig. 3 is a partial schematic diagram showing another conventional positioning device, and Fig. 4 is a partially enlarged view showing the operation status of the automatic processing device shown in FIG. 1, FIG. 5 is a partial schematic diagram showing the positioning device according to the present invention, and FIG. 6 is an explanation showing the operation of the positioning device according to the present invention. It is a diagram. 2, 3, 21...transporting means, 4...detecting means,
22... Control means, 11, 12... Transported object,
lr ₁ , lr ₂ ...Overrun amount.

Claims (1)

[Scope of utility model registration request] a conveyance means for conveying the object to be conveyed; a detection means disposed in a conveyance system of the conveyance means; connected to the detection means and the conveyance means, respectively, and drives the conveyance means based on a signal from the detection means; In the positioning device, the detection means are arranged in a pair separated by a predetermined distance in the transport direction, and are configured to position and stop the conveyed object held by the transport means at a predetermined position of the transport system. At the same time, a pair of detected parts is provided on the conveyed object corresponding to each of the pair of detection means, and one of the pair of detected parts of the conveyed object is provided in each of the opposite conveying directions. When a detected part located on the front side in the conveyance direction is detected by one of the pair of detection means during the process of conveying the conveyed object, the conveyance speed of the conveyance means is reduced, and then one of the detection means When a detected part located on the rear side in the transport direction is detected by one of the detection means and a detected part located on the front side in the transport direction is detected by the other detection means, the transport means is braked and stopped. At the same time, each detection means located on the front side in the conveyance direction is moved from a predetermined position to a predetermined position on the front side in the conveyance direction by each overrun amount from when the conveyance means is braked until it is stopped. 1. A positioning device characterized in that the device is arranged to be shifted relative to each detected portion of a transported object when the object is positioned.