JP3927798B2 - Transfer equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a configuration of a transfer device that transfers an article (particularly a flat article) while holding it on a hand by air suction.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, there has been a transfer device that sucks and holds a flat article (single sheet), for example, a wafer or liquid crystal glass on a hand, takes it out of a cassette that stores the wafer, etc., and transfers it to an inspection device or processing device Are known.
In this transfer device, the hand is provided with a suction hole for sucking and holding the article, an air hole connected to the suction means, and a groove through which the air hole and the suction hole communicate with each other, By sucking air with the suction means, the article is held in the hand.
[0003]
[Problems to be solved by the invention]
In this configuration, let us consider a case where a power failure occurs due to, for example, a power supply unit that supplies power to the transfer device in a state where an article is adsorbed by a hand. In this case, the driving of the suction means is also stopped, and the suction holding force with respect to the article of the hand is lost.
When a power failure occurs when the hand is not transferring, it is unlikely that the article will be displaced from the hand even if the holding power is lost. In this case, since the article is sucked and held again while keeping the proper position with respect to the hand, an operation for adjusting the article to the proper position is unnecessary.
On the other hand, when the hand is in the middle of transferring work, especially when a power failure occurs while accelerating or stopping while holding the article, the article on which the inertial force will be displaced from the hand. Is also conceivable. In this state, even if the power is restored from the power failure and the suction means is driven again, the article will be held in a misaligned position with respect to the hand, causing trouble that the article cannot be properly delivered to other devices. It becomes. Therefore, in this case, it is necessary to return the article to an appropriate position and hold it on the hand.
[0004]
However, it has been difficult for the conventional transfer apparatus to attach a sensor for detecting whether an article is properly held in the hand. That is, when storing a flat article in a cassette or the like, it is customary to store it in a state where a large number of layers are stacked at short intervals in order to save the storage space, and the article is inserted into such a narrow space. The hand that takes out the inevitably required a high degree of compactness, and there was no room for mounting the sensor on the hand.
[0005]
Therefore, it has not been possible to automatically confirm whether the article is held at an appropriate position in the hand or whether the article is held at an inappropriate position due to a shift when a power failure occurs.
Eventually, in such a case, the operator goes to the transfer device, moves the hand to a position where it can be seen, and confirms whether the article is held in an appropriate position by the hand. In addition, this confirmation work was very complicated.
[0006]
The present invention has been made in view of this point, and its purpose is to easily detect whether or not an article such as a wafer or glass for liquid crystal is properly held in the hand without impairing the compactness of the hand. It is in providing the transfer apparatus which can do.
[0007]
[Means for Solving the Problems]
The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.
[0008]
[Means for Solving the Problems]
That is, in claim 1,
A method of using a transfer device for transferring an object while holding an article by a hand,
The hand is formed with a first suction hole for sucking and holding the article and a first air hole connected to the first suction hole through a groove,
Further, the hand is formed with a second suction hole and a second air hole connected to the second suction hole through a groove ,
Wherein the transfer device comprises a first suction means connected to the front Symbol first air hole, with a second suction means connected to the second air holes are provided, the suction pressure of the second suction means the second pressure detecting means provided we are detecting a
When the article is held in an appropriate position by the hand, the second suction hole is not closed by the article and is close to an outline of the article held in the appropriate position, When the article is displaced outside the outline of the article at an appropriate position, the article is closed .
[0009]
In claim 2,
Furthermore, the hand is provided with a third suction hole,
The third suction hole is connected to the first suction means, the transfer device is provided with a first pressure detecting means for detecting the suction pressure of the first suction means,
When the article is held in an appropriate position by the hand, the third suction hole is a position closed by the article and close to an outline of the article held in the appropriate position; When the article is displaced inside the outline of the article at the proper position, the article is closed .
[0010]
In claim 3,
In the transfer device, the third suction hole is connected to the first air hole, and at least a part of the passage groove connecting the first suction hole and the first air hole is formed by: It is also used as a groove that connects the third suction hole and the first air hole.
[0011]
In claim 4,
In the transfer device, the second suction means and the second pressure detection means are operated only when the position of the article is detected after power supply to the first suction means is cut off. .
In claim 5,
In the transfer apparatus, the second suction means, said first suction means connected to the first air holes, you as that connected to the second air hole through the valve, but.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view showing a state of an automatic guided vehicle in a clean room.
2 is a side sectional view of the automatic guided vehicle, and FIG. 3 is a plan view of the same.
4A and 4B are plan views of the wafer. FIG. 4A shows a wafer having an orientation flat, and FIG. 4B shows a wafer having a notch.
[0013]
First, the whole structure of the automatic guided vehicle 1 provided with the transfer apparatus of this invention is demonstrated. In addition, in the following description, the arrow F direction in FIG. 1 is demonstrated as the front for convenience.
[0014]
As shown in FIG. 1, the automatic guided vehicle 1 is configured as a tracked carriage that automatically travels on the traveling rails 20 and 20 in the clean room, and the vehicle body 2 is supported by the traveling wheels 9 in the front, rear, left, and right corners, These traveling wheels 9 are driven by a drive motor 8 (FIG. 2), and are driven on the traveling rails 20 and 20 by four-wheel drive.
[0015]
.., And a stocker 22 are disposed along the traveling rails 20 and 20, and a plurality of cassettes 23, 23... Are arranged side by side at a predetermined interval on the stocker 22. Yes.
Each of the cassettes 23, 23,... Is configured in a box shape, and its opening is placed toward the traveling rails 20 and 20, and on the inner surface of the cassette 23 sandwiching the opening, each side edge of the wafer 10 is placed. Are arranged at equal intervals in the vertical direction, and wafers 10, 10... Are horizontally placed and stored in each shelf.
In this embodiment, the stocker 22 is a flat type, but instead of this, an automatic equipped with a loading / unloading port for the cassette 23, a number of shelves, and a stacker crane for transferring the cassette 23 between the shelves and the loading / unloading port. It may be configured in a warehouse.
[0016]
As shown in FIGS. 2 and 3, a single wafer transfer device 3 for transferring wafers 10, 10... Is arranged in the center of the body 2 of the automatic guided vehicle 1 so as to sandwich the wafer transfer device 3 therebetween. At the front and rear, an attitude alignment device 4 and a buffer cassette 5 are arranged.
The posture alignment device 4 is for aligning the direction and the center position of the wafers 10..., And the buffer cassette 5 is for temporarily storing the wafers 10.
The single wafer transfer device 3 temporarily stores the wafers 10 received from the device groups 21 and 22 on the shelves in the buffer cassette 5, or takes out the wafers 10 on the shelves in the buffer cassette 5, It is used for transfer work such as adjusting the position and posture of the wafer 10 by the aligning device 4 and then transferring it to the processing device 21.
[0017]
The wafer 10 is formed in a substantially disk shape made of silicon single crystal.
Since the silicon crystal has orientation, a means for identifying the direction is formed. For example, as shown in FIG. 4 (a), an orientation flat (orientation flat) 10a formed by cutting out a part of the outer periphery of the wafer 10 in a straight line, or as shown in FIG. 4 (b). The notch 10b is formed by cutting out a part of the outer periphery of the wafer 10.
In any case, an ID mark 11 in which wafer information such as a wafer manufacturing history is encoded is engraved on the periphery of the front or back surface. The ID mark 11 is read by an appropriate mark reading device installed in the above-described posture alignment device 4, whereby the automatic guided vehicle 1 can obtain wafer information.
[0018]
Next, the transfer device 3 will be described.
As shown in FIGS. 2 and 3, the transfer device 3 includes transfer arms 30M and 30S, a base 38, a turntable 39, and the like.
The base 38 is embedded in the center of the vehicle body 2 and is configured to be moved up and down by a lifting mechanism (not shown). A turntable 39 is rotatably mounted on the upper surface of the base 38, and a pair of transfer arms 30M and 30S are mounted on the turntable 39.
[0019]
The transfer arm 30M (30S) is a scalar arm type robot hand in which a link mechanism is assembled by a transfer hand 31, a first arm 32, and a second arm 33, and is expanded and contracted by a servo motor (not shown). It is configured freely.
[0020]
The transfer hand 31 is formed in a flat plate shape, and suction holes 34 and 34 are respectively provided at the bifurcated tip portions, and the wafer 10 as an article is sucked and held by the transfer hand 31 by suction with a vacuum pump. Is configured to do. This detailed configuration will be described in detail.
[0021]
On one transfer arm 30M, a mapping sensor 35 is attached to the end of the transfer hand 31 opposite to the suction holes 34, 34.
This mapping sensor 35 has a “V” shape in plan view with the tip divided into two forks, and the tips are photoelectric sensors 35a and 35a. With this configuration, the base 38 is raised to bend and extend the transfer arm 30M, the mapping sensor 35 is brought close to the buffer cassette 5, and then the base 38 is lowered to be buffered by the photoelectric sensors 35a and 35a. By detecting each shelf of the cassette 5, it is possible to detect whether or not the wafer 10 is placed on each shelf.
[0022]
Next, the structure of the transfer hand 31 of the present invention will be described.
FIG. 5 is a perspective view of the transfer hand, and FIG. 6 is a perspective view for explaining wafer position detection in the transfer hand.
[0023]
The transfer hand 31 is formed in a rectangular flat plate shape, one side in the longitudinal direction (the front end side of the transfer hand 31) is notched in a U shape, and the front end side is symmetrically branched into two forks. Yes. Then, suction holes 34 and 34 for sucking the wafer 10 and holding it on the transfer hand 31 are formed on the top surfaces of the branched tips. The pair of suction holes 34, 34 corresponds to the first suction hole in the present invention.
[0024]
A first air hole 40 is formed in the upper surface of the transfer hand 31 at a portion located on the opposite side in the longitudinal direction from the side on which the suction hole 34 is formed. One end of an air pipe 50 is connected to the first air hole 40. The air pipe 50 is passed through the first arm 32 and the second arm 33, and the first vacuum pump 41 serving as suction means on the other end side. Is connected. A first pressure detection switch 42 is connected to the air pipe 50 so that the suction pressure by the first vacuum pump 41 can be detected. The first pressure detection switch 42 is connected to a control device (not shown) of the automatic guided vehicle 1. It is connected.
[0025]
A first groove 43 is formed in the transfer hand 31. The first passage 43 is formed in a “U” shape in plan view, and the suction holes 34 are connected to both ends thereof, and the first air hole 40 is connected to the middle portion thereof. With this configuration, the first passage groove 43 allows the single first air hole 40 and the two adsorption holes 34 to communicate with each other.
[0026]
Further, a pair of positional deviation detection holes 44 and 44 are formed in the middle part in the longitudinal direction of the transfer hand 31. The positional deviation detection holes 44 and 44 are provided at positions that do not overlap the wafer 10 in plan view when the wafer 10 is held on the transfer hand 31 at an appropriate position. However, the positions where the position shift detection holes 44 are formed are close to the outline of the wafer 10 held at an appropriate position.
The position shift detection holes 44 and 44 correspond to the second suction holes in the present invention.
[0027]
On the other hand, a second air hole 45 is provided in the transfer hand 31 at a location close to the first air hole 40. One end of an air pipe 51 is connected to the second air hole 45, and the air pipe 51 is passed through the first arm 32 and the second arm 33, and a vacuum pump 46 as suction means is connected to the other end side. Is done. A second pressure detection switch 47 is connected to the air pipe 51 so that the suction pressure by the vacuum pump 46 can be detected. The second pressure detection switch 47 is connected to a control device (not shown) of the automatic guided vehicle 1. ing.
The vacuum pump 46 is not always driven, and is used only when detecting the position of the wafer 10 after a power failure or the like, as will be described later.
[0028]
A second groove 48 is formed inside the transfer hand 31. The second passage groove 48 is formed in a “U” shape in a plan view, and is disposed in parallel to and inside the first passage groove 43. The misalignment detection holes 44 and 44 are connected to both ends of the second passage groove 48, and the second air hole 45 is connected to an intermediate portion thereof. With this configuration, the second groove 48 allows the single second air hole 45 to communicate with the two positional deviation detection holes 44.
[0029]
Further, a pair of positional deviation confirmation holes 49 and 49 are formed in the middle portion in the longitudinal direction of the transfer hand 31. The misalignment confirmation holes 49 and 49 are provided at positions overlapping the wafer 10 in plan view when the wafer 10 is held on the transfer hand 31 at an appropriate position. However, the positions where the position deviation confirmation holes 49 are formed are close to the outline of the wafer 10 held at an appropriate position.
The misregistration confirmation holes 49 and 49 correspond to the third suction hole in the present invention.
[0030]
The misalignment confirmation holes 49 and 49 communicate with the midway portion of the first passage 43 and are connected to the first air hole 40. In other words, a part of the first passage groove 43 connecting the suction hole 34 and the first air hole 40 is also used as a passage groove connecting the positional deviation confirmation hole 49 and the first air hole 40. means.
[0031]
The operation of the above configuration will be described with reference to FIG.
A position A of the wafer 10 indicated by a solid line in FIG. 6 is an appropriate holding position of the wafer 10 on the transfer hand 31. Normally, the wafer 10 is placed at this position, and the first vacuum pump 41 is driven to generate a vacuum, which is sucked and held by the suction hole 34, and in this state, the transfer operation by the transfer device 3 is performed. .
When the wafer 10 is held by the transfer hand 31 at the proper position A, the position shift confirmation holes 49 and 49 of the transfer hand 31 are closed by the wafer 10 as shown in FIG. The deviation detection holes 44 and 44 are not closed.
[0032]
In this configuration, let us consider a case where a power failure occurs due to, for example, a power supply unit that supplies power to the transfer apparatus 3 while the wafer 10 is attracted to the transfer hand 31. In this case, the power supply to the first vacuum pump 41 is also cut off, and the suction holding force of the transfer hand 31 to the wafer 10 is lost.
Here, when a power failure occurs when the transfer hand 31 is not performing the transfer operation, the wafer 10 is displaced from the appropriate position A with respect to the transfer hand 31 even if the holding force is lost. This is unlikely, and when the first vacuum pump 41 is driven again after a power failure, the wafer 10 is again sucked and held while maintaining the proper position with respect to the transfer hand 31. When returning from a power failure, it is not necessary to adjust the wafer 10 to an appropriate position.
On the other hand, when the transfer hand 31 is in the middle of performing the transfer operation, particularly when a power failure occurs during acceleration or stop while holding the wafer 10, the wafer 10 to which the inertial force is applied is transferred. It is conceivable that the position is shifted from the loading hand 31. In this state, even if the power supply is restored from the power failure and the first vacuum pump 41 is driven again, the wafer 10 is moved to a position shifted from the appropriate position (for example, position B or position C) as indicated by a chain line. If the wafer 10 is held as it is, it causes a trouble that the wafer 10 cannot be properly delivered to another apparatus. Therefore, in this case, it is necessary to return the wafer 10 to an appropriate position and hold it on the transfer hand 31.
[0033]
In this embodiment, detection of whether or not the position of the wafer 10 is at the proper position A is performed as follows.
The power is restored after the power failure. Then, the control device of the transfer device 3 that has detected the power failure detects the resupply of power, first drives the two vacuum pumps 41 and 46, and detects the pressure detected by the two pressure detection switches 42 and 47. Investigate.
[0034]
If the position of the wafer 10 is at the proper position A, the positional deviation confirmation hole 49 is blocked by the wafer 10 (of course, the suction hole 34 is blocked), and the first pressure detection switch 42 is vacuumed. Become pressure. On the other hand, since the displacement detection hole 44 is opened, the second pressure detection switch 42 detects atmospheric pressure.
[0035]
On the other hand, if the position of the wafer 10 is in the position B shifted forward, both the position shift confirmation hole 49 and the position shift detection hole 44 are opened, so that the two pressure detection switches 42 and 47 both detect atmospheric pressure. Will do.
[0036]
On the other hand, if the position of the wafer 10 is at the position C shifted backward, the position shift confirmation hole 49 and the position shift detection hole 44 are closed, so that the two pressure detection switches 42 and 47 both detect the vacuum pressure. It will be.
[0037]
Therefore, the control device checks the pressures detected by the two pressure detection switches 42 and 47 after recovery from the power failure, the first pressure detection switch 42 detects the vacuum pressure, and the second pressure detection switch 47 detects the atmospheric pressure. Is detected, it is determined that the wafer 10 is not displaced from the appropriate position A.
On the other hand, if the combination of the detection values of the two pressure detection switches 42 and 47 is other than the above, it is determined that the wafer 10 is misaligned.
[0038]
The control device of the transfer device 3 can exchange signals with the controller of the automatic guided vehicle system, and can transmit a signal indicating whether or not the wafer 10 is misaligned to the controller. Yes.
The controller is configured so that the operator can be notified by the notification means such as a lamp or buzzer that the wafer 10 is misaligned with respect to the automatic guided vehicle 1.
Therefore, when returning from the power failure as described above, the operator does not need to visually check whether or not the wafer 10 is held at an appropriate position. Only when the controller is informed that the positional deviation of the wafer 10 has occurred, the operator need only visit the location of the automated guided vehicle 1 and perform the wafer 10 positional adjustment work.
For this reason, it is possible to restart the transfer operation of the transfer device 3 earlier than when the operator visually inspects each time a power failure occurs. As a result, the automatic guided vehicle system can be operated more efficiently.
[0039]
In the present embodiment, the first air hole 40 and the second air hole 45 are connected by separate vacuum pumps, but may be connected to a common vacuum pump. For example, the vacuum pump 41 may be connected to the second air hole 45 via a valve, and the valve may be opened when the positional deviation of the wafer 10 is confirmed such as during a power failure.
In this embodiment, the vacuum pumps 41 and 46 are used as the suction means. However, the suction pump is not limited to the vacuum pump. For example, other suction means such as a vacuum ejector may be used.
Furthermore, in this embodiment, confirmation of the positional deviation of the wafer 10 is a special case such as a power failure, but it may be confirmed every time the wafer 10 is mounted or may be confirmed constantly.
[0040]
Actually, the other apparatus (the processing apparatus 21 or the like) to which the wafer 10 is transferred by the transfer hand 31 allows a slight error in the transfer position of the wafer 10, so that the allowable range is taken into consideration. Thus, the opening positions of the positional deviation detection hole 44 and the positional deviation confirmation hole 49 are adjusted. Thus, even if the wafer 10 is not strictly positioned at the appropriate position A, as long as the wafer 10 is positioned within a certain range (a range corresponding to the allowable range) with the appropriate position 10 as the center, the control device Therefore, it is determined that there is no positional deviation, and the operator is not notified of the necessity of position adjustment of the wafer 10.
[0041]
【The invention's effect】
Since the present invention is configured as described above, the following effects can be obtained.
[0042]
Ie upon claim 1,
Whether or not the article is in an appropriate position on the hand can be determined by detecting the suction pressure of the second suction hole by the pressure detection means without visual observation, so that the operator is often forced to perform visual confirmation work. Disappears.
In addition, since it is determined whether or not the article is in an appropriate position on the hand using air pressure for adsorbing the article, the compactness of the hand is less than the configuration in which a special sensor is provided on the hand. It is good.
[0043]
Oite in claim 2,
When the article is displaced from the proper position to one side, the second suction hole is opened, and when the article is displaced to the other side, the third suction hole is closed. By detecting this by the pressure detection means, even when the article is displaced in any direction, the displacement can be accurately detected.
[0044]
Oite in claim 3,
The structure of the passage groove can be simplified and it can contribute to the reduction of the manufacturing cost.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a state of an automatic guided vehicle in a clean room.
FIG. 2 is a side sectional view of the automatic guided vehicle.
FIG. 3 is also a plan view.
FIG. 4 is a plan view of a wafer. (A) shows a wafer having an orientation flat, and (b) shows a wafer having a notch.
FIG. 5 is a perspective view of a transfer hand.
FIG. 6 is a perspective view for explaining wafer position detection in a transfer hand.
[Explanation of symbols]
3 Transfer device 10 Wafer (article)
31 Transfer hand (hand)
34 Suction hole (first suction hole)
40 First air hole 41 First vacuum pump (suction means)
42 First pressure detection switch (pressure detection means)
43 passage groove 44 displacement detection hole (second suction hole)
45 Second air hole 46 Second vacuum pump (suction means)
47 Second pressure detection switch (pressure detection means)
48 passage groove 49 Misalignment confirmation hole (third suction hole)

Claims (5)

A method of using a transfer device for transferring an object while holding an article by a hand,
The hand is formed with a first suction hole for sucking and holding the article and a first air hole connected to the first suction hole through a groove,
Further, the hand is formed with a second suction hole and a second air hole connected to the second suction hole through a groove ,
Wherein the transfer device comprises a first suction means connected to the front Symbol first air hole, with a second suction means connected to the second air holes are provided, the suction pressure of the second suction means the second pressure detecting means provided we are detecting a
When the article is held in an appropriate position by the hand, the second suction hole is not closed by the article and is close to an outline of the article held in the appropriate position, When the article is displaced outside the outline of the article at a proper position, the article is closed.
A method of using the transfer apparatus characterized by the above. Furthermore, the hand is provided with a third suction hole,
The third suction hole is connected to the first suction means, the transfer device is provided with a first pressure detecting means for detecting the suction pressure of the first suction means,
When the article is held in an appropriate position by the hand, the third suction hole is a position closed by the article and close to an outline of the article held in the appropriate position; When the article is displaced inside the outline of the article at the proper position, the article is closed.
The use method of the transfer apparatus of Claim 1 characterized by the above-mentioned. In the transfer device, the third suction hole is connected to the first air hole, and at least a part of the passage groove connecting the first suction hole and the first air hole is formed by: It is also used as a groove that connects the third suction hole and the first air hole,
A method for using the transfer apparatus according to claim 2. In the transfer apparatus, the second suction unit and the second pressure detection unit are operated only when the position of the article is detected after power supply to the first suction unit is cut off. To
The usage method of the transfer apparatus in any one of Claims 1-3. In the transfer apparatus, the second suction means is characterized in that the first suction means connected to the first air hole is connected to the second air hole via a valve.
The usage method of the transfer apparatus in any one of Claims 1-4.

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