JP2024005352A - Hand for work transfer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the other hand to properly adsorb and hold a work even if a situation where the work is not mounted in any hand occurs in simple configuration in a case where a vacuum adsorption type hand is configured in a multistage style.

SOLUTION: A hand A1 for work transfer comprises: a plurality of hand bodies 2a-2f disposed at predetermined intervals in a vertical direction; and a support base 3 supporting the plurality of hand bodies 2a-2f in proximal ends thereof. Each of the hand bodies 2a-2f includes one or more adsorption pads 21 opened on the top faces thereof, and the adsorption pad 21 of each of the hand bodies 2a-2f is communicated to a vacuum source (5) via a plurality of ventilation paths 41 provided for each of the hand bodies 2a-2f. A negative pressure actuation valve 6, in which an air flow rate is narrowed down by a negative pressure of the vacuum source (5) when the adsorption pad 21 is in an open state, is provided in each of the plurality of ventilation paths 41.

SELECTED DRAWING: Figure 5

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a workpiece transporting hand, which is used to transport thin plate-like workpieces such as substrates and semiconductor wafers, and is configured to be able to transport a plurality of workpieces at once.

A transfer robot equipped with this type of workpiece transfer hand holds and transfers the workpiece on the hand. Such a transport robot is used, for example, to take out a workpiece from a cassette in which multiple workpieces are stored in multiple stages and transport the workpiece to a processing device, or to return processed workpieces to the cassette. .

As a method for holding a workpiece on a hand, there is a suction type method in which vacuum pressure is applied to a suction pad provided on the upper surface of the hand, as shown in Patent Document 1, for example.

On the other hand, for example, in order to increase processing efficiency by taking out a plurality of workpieces from a cassette at once and returning them to the cassette, the hand may be configured in a multi-stage manner, as shown in Patent Document 2.

When configuring suction hands in multiple stages, if the suction pads of all hands are connected to a common vacuum source, if a situation arises where a workpiece cannot be placed correctly on one of the hands, the suction pads of all hands will Air continues to be sucked in from the suction pad of the hand, and the vacuum pressure no longer acts properly on the suction pad of the hand on which the workpiece is placed, resulting in a problem that the workpiece cannot be properly suctioned and held.

To solve this problem, for example, each hand should be provided with a sensor that detects whether a workpiece is placed on it, and a solenoid valve should be installed in each air path leading to the suction pad of each hand. A possible solution is to close the solenoid valve of the air path leading to the suction pad of the hand that is not being used.

However, this measure is difficult to adopt because it increases the complexity and cost of the device and control.

JP2020-161585A JP 2021-158243 Publication

The present invention was devised under the above-mentioned circumstances, and when vacuum suction type hands are configured in multiple stages, the present invention has a simple configuration that solves the situation where a workpiece is not placed on any of the hands. The objective is to enable other hands to properly attract and hold the workpiece even if this occurs.

In order to solve the above problems, the present invention employs the following technical means.

That is, the workpiece conveyance hand provided by the present invention includes a plurality of hand bodies arranged vertically at predetermined intervals, and a support base that supports the plurality of hand bodies at their base ends. Each of the hand bodies has one or more suction pads opening on the upper surface thereof, and the suction pads of each of the hand bodies are connected to a plurality of ventilation channels provided for each hand body. are connected to a vacuum source via a vacuum source, and each of the plurality of air passages is provided with a negative pressure operated valve that throttles the air flow rate using the negative pressure of the vacuum source when the suction pad is in an open state. It is characterized by

In a preferred embodiment, the support base has a bottom plate, and the bottom plate includes an upright vacuum source communication port and the plurality of hands arranged in an annular shape surrounding the vacuum source communication port. A number of negative pressure operated valves corresponding to the number of bodies are provided, and the plurality of air passages are commonly communicated with the vacuum source communication port via the negative pressure operated valves.

In a preferred embodiment, communication from the suction pad of each hand body to each of the negative pressure operating valves is through a ventilation passage formed inside each of the hand bodies, and between the ventilation passage of the hand body and each of the negative pressure operation valves. This is done through a ventilation path made of a tube that connects the operating valve.

In a preferred embodiment, communication between each of the negative pressure operated valves and the vacuum source communication port is provided by a ventilation passage formed radially in the bottom plate.

In a preferred embodiment, each of the plurality of hand bodies is provided with a sensor that detects whether a workpiece is placed thereon.

When a workpiece is not placed on one of the plurality of hand bodies, the suction pad of the hand body becomes open, and the air flow rate of the air passage corresponding to the hand body is automatically controlled by the negative pressure operating valve. narrowed down to target. Therefore, there is no negative pressure drop due to air flowing from the suction pad of the hand body toward the vacuum source, and in other words, the suction force by the suction pad of the hand body on which a workpiece other than the hand body is properly placed is reduced. The workpiece is properly held.

As described above, according to the workpiece transfer hand having the above configuration, when the vacuum suction type hand bodies are configured in a multi-stage manner, the simple configuration prevents a situation in which a workpiece is not placed on one of the hand bodies. Also, the other hand bodies can properly attract and hold the workpiece.

Other features and advantages of the invention will become more apparent from the detailed description given below with reference to the drawings.

FIG. 2 is a side view of a workpiece conveyance hand according to an embodiment of the present invention. FIG. 2 is a plan view of the workpiece conveying hand shown in FIG. 1. FIG. FIG. 3 is an enlarged sectional view taken along line III-III in FIG. 2. FIG. FIG. 3 is a plan view of the main part of the workpiece conveying hand shown with the ceiling plate of the support base removed. FIG. 5 is a cross-sectional view taken along line V-V in FIG. 4. FIG. FIG. 2 is a longitudinal cross-sectional view showing the specific configuration and operation of a negative pressure operated valve. FIG. 2 is a longitudinal cross-sectional view showing the specific configuration and operation of a negative pressure operated valve.

Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

The workpiece transfer hand A1 is moved in a predetermined three-dimensional space and its posture is controlled by a robot (not shown), and as shown in FIG. It includes a support base 3 that supports the hand bodies 2a to 2f at their base ends. In the embodiment, six hand bodies 2a to 2f of the same type are arranged in a line in the vertical direction. The support base 3 also has a bottom plate 31 and a ceiling plate 33.

The hand bodies 2a to 2f have a plate shape made of light metal or hard resin, and as shown in FIG. 2, the tip side has a bifurcated fork shape. This bifurcated fork-like tip is a part on which a thin plate-shaped work W such as a semiconductor wafer is placed and held by suction, and three suction pads 21 are provided in this part.

As shown in detail in FIG. 3, the suction pad 21 is a rubber member having a skirt portion 213 that expands upward at the top of a cylindrical portion 212 having an airway 211. The cylindrical portion 212 is provided so as to fit into the holding hole 22 formed in the cylindrical portion.

The airway 211 of the suction pad 21 is connected to a negative pressure operating valve 6 or a vacuum source communication port 5, which will be described later, through the air passage 4 (41, 321, 34, 313, 314). This will be explained in detail below.

As shown in FIGS. 2 and 3, the ventilation passages 41 formed in the hand bodies 2a to 2f are provided with grooves 23 on the lower surfaces of the hand bodies 2a to 2f, and the grooves 23 are formed with a film 24 made of aluminum or the like. It is formed by covering.

The base end side of the lowest hand body 2a is held between the bottom plate 31 of the support base 3 and the spacer block 32, as shown in FIG. The proximal ends of the hand bodies 2b to 2e are held between the upper and lower spacer blocks 32, and the base end of the uppermost hand body 2f is held between the spacer block 32 and the holding plate 35. and are supported by a support base 3, respectively.

The ventilation passages 41 of the upper five hand bodies 2b to 2f are connected to the ventilation ports 322 at the rear ends of the spacer blocks 32 through ventilation passages 321 formed in the spacer blocks 32 that are in contact with the lower parts of the hand bodies 2b to 2f. The ventilation path 41 of the lowest hand body 2a is connected to the ventilation port 323 provided upright on the bottom plate 31 via the ventilation path 313 formed in the bottom plate 31 of the support base 3. It is being The ventilation passage 313 can be formed by forming a groove 313a on the bottom surface of the bottom plate 31 and covering the groove 313a with a sheet 313b made of aluminum or the like.

As shown in FIGS. 4 and 5, the bottom plate 31 includes an upright vacuum source communication port 5 and the six hand bodies 2b arranged upright in an annular shape surrounding the vacuum source communication port 5. -2f and six negative pressure operated valves 6 corresponding to the valves 6 are provided.

The six ventilation ports 322, 323 corresponding to the ventilation passages 41 of the respective hand bodies 2a to 2f are connected to the upper ends of the six negative pressure operated valves 6 via the ventilation passages 34 made of tubes. The lower ends of the two negative pressure operated valves 6 are communicated with the vacuum source communication port 5 via radial ventilation passages 314 formed in the bottom plate 31. A tube 51 is connected to the vacuum source communication port 5, and after being routed inside the arm of a robot (not shown), the tube 51 is connected to a vacuum source such as a vacuum pump (not shown) via an on-off valve or the like. connected to. The ventilation passage 314 can be formed by forming a groove 314a on the bottom surface of the bottom plate 31 and covering the groove 314a with a sheet 314b made of aluminum or the like.

6 and 7 show specific configuration examples of each negative pressure operated valve 6.

The negative pressure operating valve 6 operates in a state in which the suction pad 21 adsorbs the workpiece W and is closed (adsorption state) and in a state in which the suction pad 21 opens without adsorbing the workpiece W when negative pressure is applied by the vacuum source. This is an operating valve whose operating state changes between (non-adsorption state) and non-adsorption state.

As shown in FIGS. 6 and 7, the negative pressure operated valve 6 includes, for example, a housing 61, a movable body 62, a sealing material 63, and a biasing member 64. The housing 61 accommodates a movable body 62 and has a vacuum side passage 611 and a workpiece side passage 612. The vacuum side passage 611 is connected to the ventilation passage 314 of the bottom plate 31 of the support base 3, and is communicated with a vacuum source (not shown) via the vacuum source communication port 5. The workpiece side passage 612 is connected to the tube 34 and communicated with the suction pad 21 via the ventilation passage 321 of the spacer block 32 or the ventilation passage 41 of the hand bodies 2a to 2f.

The movable body 62 is housed in the internal space of the housing 61 and is slidable in the vertical direction in the figure. The biasing member 64 is interposed between the housing 61 and the movable body 62. The biasing member 64 applies a biasing force upward in the drawing to the movable body 62, and is, for example, a compression coil spring. The sealing material 63 is attached near the lower end of the movable body 62, and is, for example, an O-ring.

The movable body 62 has a generally cylindrical shape and has a ventilation hole 621 and an opening 622. The ventilation hole 621 is a small diameter aperture hole formed at the lower end of the movable body 62. The opening 622 is an air flow path formed in the peripheral wall of the movable body 62.

When negative pressure is applied by the vacuum source, if the workpiece W is not placed on the hand bodies 2a to 2f and the suction pad 21 is in the non-adsorption state in which it is open, the suction force of the vacuum pressure (negative pressure) will cause the small diameter to pass through. Air flows through the air holes 621, and the movable body 62 moves downward in the figure as shown in FIG. 6 against the biasing force of the biasing member 64. Here, the sealing material 63 is in close contact with the housing 61, and the flow path on the opening 622 side is closed. The movable body 62 is pressed downward in the figure by the air pressure flowing through the vent hole 621, and the state in which the sealing material 63 is kept in close contact with the housing 61 is maintained. At this time, the negative pressure operated valve 6 is in a substantially closed state. Since the ventilation hole 621 is a small-diameter throttle hole, a decrease in the vacuum pressure on the suction pad 21 side is suppressed when the negative pressure operating valve 6 is in a substantially closed state.

When the workpiece W is properly placed on the hand bodies 2a to 2f and the workpiece W is attracted to the suction pad 21 when negative pressure is applied by the vacuum source, the suction flow rate from the ventilation path 41 is reduced or eliminated. Then, as shown in FIG. 7, the movable body 62 is pressed upward in the figure by the urging force of the urging member 64, and the sealing material 63 is separated from the housing 61. At this time, the vacuum side passage 611 and the workpiece side passage 612 are in communication with each other through the opening 622, and the negative pressure operating valve 6 is in an open state.

In this embodiment, each of the hand bodies 2a to 2f is provided with a sensor 7 that detects whether a workpiece W is placed thereon. This sensor 7 can be of an optical type that includes a laser emitting section and a light receiving section. In this embodiment, six laser oscillation devices 71 are installed inside the support base 3, corresponding to the sensors 7 provided on each of the hand bodies 2a to 2f.

Next, the operation of the workpiece conveying hand A1 having the above configuration will be explained.

When the workpiece W is not properly placed on any of the six hand bodies 2a to 2f, the suction pads 21 of the hand bodies 2a to 2f become open, but as described above, Since the negative pressure operating valve 6 communicating with the open suction pad 21 is automatically brought into a substantially closed state by the negative pressure of the negative pressure source, the workpiece W is properly placed on the other hand bodies 2a to 2f. Negative pressure in the system leading to the suction pad 21 is maintained, and the appropriate suction and holding state of the workpiece W by the other hand bodies 2a to 2f is maintained.

In this way, the negative pressure operating valve 6 is operated using the negative pressure of the vacuum source that is inherently provided in the workpiece conveying hand A1 equipped with the suction pad 21, so that it has a simple configuration and can be used in the multistage hand bodies 2a to 2. Even in a situation where no workpiece is placed on any of the hand bodies at 2f, the suction and holding state of the workpiece W by the other hand bodies can be maintained.

In the embodiment, communication is formed in the bottom plate 31 between the plurality of negative pressure operated valves 6 arranged in an annular manner on the bottom plate 31 of the support base and the vacuum source communication port 5 provided at the center of arrangement of these negative pressure operated valves 6. Since this is done through the radial ventilation passages 314, the plurality of negative pressure operated valves 6 and the vacuum source communication ports 5 can be efficiently arranged within the support base 3.

Although the operation of the negative pressure operating valve 6 does not notify the absence of the workpiece W on the hand bodies 2a to 2f, in this embodiment, it does not notify whether the workpiece W is placed on each of the hand bodies 2a to 2f. Since the detection sensor 7 is provided, it is possible to detect problems in workpiece conveyance and take appropriate measures.

Of course, the present invention is not limited to the above-described embodiments, and any design changes within the scope of the matters described in each claim are all included within the scope of the present invention.

W: Workpiece, A1: Hand for transporting workpiece, 2a to 2f: Hand body, 21: Suction pad, 3: Support base, 31: Bottom plate, 34: Tube (ventilation path), 4: Ventilation path, 41: Ventilation path ( of the hand body), 5: Vacuum source communication port, 6: Negative pressure operation valve, 7: Sensor

Claims (5)

A workpiece conveying hand comprising a plurality of hand bodies arranged at predetermined intervals in the vertical direction, and a support base supporting the plurality of hand bodies at their base ends,
Each of the hand bodies has one or more suction pads opening on the upper surface thereof,
The suction pad of each hand body is connected to a vacuum source via a plurality of ventilation passages provided for each hand body,
The workpiece conveying hand is characterized in that each of the plurality of ventilation passages is provided with a negative pressure operated valve that throttles the air flow rate using the negative pressure of the vacuum source when the suction pad is in an open state. . The support base has a bottom plate, and the bottom plate includes an upright vacuum source communication port and a plurality of hand bodies arranged in an annular shape surrounding the vacuum source communication port, the number of which corresponds to the number of the plurality of hand bodies. A number of the negative pressure operated valves are provided, and the plurality of air passages are commonly connected to the vacuum source communication port via the negative pressure operated valve. Hand for transporting workpieces. The communication from the suction pad of each of the hand bodies to each of the negative pressure operated valves includes a ventilation path formed inside each of the hand bodies, and a connection between the ventilation path of the hand body and each of the negative pressure operated valves. 3. The workpiece conveyance hand according to claim 2, wherein the workpiece conveyance hand is provided with a ventilation path made of a tube. 4. The workpiece conveying hand according to claim 2, wherein communication between each of the negative pressure operated valves and the vacuum source communication port is performed by a ventilation passage formed radially in the bottom plate. 5. The workpiece conveying hand according to claim 1, wherein each of the plurality of hand bodies is provided with a sensor for detecting whether or not a workpiece is placed thereon.

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