Patent ID: 12227373

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings to be easily implemented by those skilled in the art. The present invention may be implemented in various different forms and is not limited to the embodiments described herein.

In order to clearly describe the present invention, parts that are not related to the description will be omitted, and the same or similar components in this specification are denoted by the same reference sign.

In addition, in various embodiments, a component having the same configuration will be described only in a representative embodiment by using the same reference sign, and only a configuration that is different from that of the representative embodiment will be described in other embodiments.

In the entirety of this specification, a sentence that a portion is “connected (or coupled) to” another portion includes not only a case of “being directly connected (coupled)” but also a case of “being indirectly connected (coupled) with other members interposed therebetween”. In addition, a sentence that a portion “includes” a component means that it may further include another component rather than excluding other components unless a particularly opposite statement is made.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art. Terms such as those defined in a commonly used dictionary should be construed as having a meaning consistent with the meaning of the relevant technology, and should not be construed as an ideal or excessively formal meaning unless explicitly defined in this application.

Configurations of an article transport vehicle10, a rail assembly20, and an article transport system including the article transport vehicle10and the rail assembly20for non-contact traveling in a manufacturing plant according to the present invention will be described below.

FIG.1illustrates an article transport system of a manufacturing plant according to the present invention. A semiconductor manufacturing plant that manufactures semiconductor products will be described below as an example of a manufacturing plant to which the present invention is applied. The range of manufacturing plants to which the present invention can be applied is not limited to a specific type and can be applied to manufacturing plants of various industries. For example, the article transport system according to the present invention can be applied to various manufacturing plants of display panels, electronic devices, automobiles, secondary batteries, and the like.

The semiconductor manufacturing plant includes one or more clean rooms, and manufacturing facilities1for executing semiconductor manufacturing processes can be installed in each clean room. Generally, a finally processed substrate may be completed by repeatedly executing a plurality of manufacturing processes on a substrate (for example, a wafer). After the manufacturing process is completed at a specific semiconductor manufacturing facility, the substrate is transported to the manufacturing facility1for the next manufacturing process. Here, the wafer can be transported in a state of being stored in a transport container (for example, a front opening unified pod, FOUP) capable of accommodating a plurality of substrates. The transport container in which wafers are stored can be transported by an article transport vehicle10. The article transport vehicle10may be referred to as an overhead hoist transport (OHT) that travels along rails installed on the ceiling.

With reference toFIG.1, a manufacturing facility1for executing a process in a semiconductor manufacturing plant is installed, and an article transport vehicle10that transports an article between the manufacturing facilities1and a rail assembly20that provides a travel path of the article transport vehicle10are provided. Here, when the article transport vehicle10transports an article between the manufacturing facilities1, the article may be immediately transported from the specific manufacturing facility to another manufacturing facility, or may be transported to another manufacturing facility after being stored in a storage device.

As the storage device, a stocker2in the form of a rack arranged in a duplex layer may be used. In addition, temporary storage facilities3such as a side track buffer installed on the side of the rail assembly and an under track buffer installed at the lower portion of the rail assembly20may be provided as the storage device.

Generally, the article transport vehicle10travels by rotating with a travel wheel in contact with the rail. In addition, the article transport vehicle10selectively travels in a specific direction by causing a steering wheel located above a branch area of the travel path to come into contact with a steering guide rail.

In the case of general contact driving and steering methods, vibration and an impact may occur due to the contact between the wheel and the rail, and there is a risk of failure if the vibration and impact are transmitted to the wafer. In addition, as the traveling speed of the article transport vehicle10increases, the vibration and the impact generated by the contact between the wheel and the rail increase. Thus, there is a problem that the traveling speed of the article transport vehicle10is limited. In addition, various particles may be generated due to the contact between the wheel and the rail, which may be a factor that hinders the clean environment of the manufacturing plant.

Thus, the embodiment of the present invention provides an article transport vehicle10capable of performing traveling and steering in a non-contact manner. According to the present invention, friction does not occur between the article transport vehicle10and the rail assembly20. Thus, it is possible to prevent an occurrence of vibration and an impact. Therefore, it is possible to prevent transmission of the vibration and the impact to the article, and to increase the traveling speed of the article transport vehicle10. In addition, since generation of particles due to the contact between the wheel and the rail is prevented, it is possible to maintain a clean environment in the manufacturing plant.

The article transport vehicle10may travel along the rail assembly20installed in a manufacturing plant, and receive an article from the manufacturing facility1and convey the article to another manufacturing facility1. The article transport vehicle10may be roughly configured by a traveling part for movement and an article handling part for loading and unloading an article. The article handling part may include a hand unit that grasps an article, a slide unit that horizontally moves the hand unit toward a load port of the manufacturing facility1, and a belt-type hoist unit that raises and lowers the hand unit. However, since the present invention relates to the configuration of the article transport vehicle10for traveling and steering in a non-contact manner, the description of the configuration for handling the article will be omitted, and various structures for handling the article can be applied.

The traveling part of the article transport vehicle10may include a drive device for acceleration, deceleration, braking, steering, and the like of the article transport vehicle10, and a controller that controls the drive device. The traveling parts of the article transport vehicle10may be configured in front and rear, respectively, based on the traveling direction of the article transport vehicle10. That is, the front traveling part and the rear traveling part constitute one body to convey an article, and the front traveling part and the rear traveling part may operate in cooperation with each other. In the present invention, for easy description, one traveling part will be described without distinguishing the front and rear traveling parts from each other. The present invention can be applied to an article transport vehicle10configured by two or more traveling parts.

FIGS.2and3schematically illustrate the structures of the article transport vehicle10that conveys an article between the manufacturing facilities1and the rail assembly20that provides the travel path of the article transport vehicle10in the article transport system of a manufacturing plant according to the present invention.

The article transport system of a manufacturing plant according to the present invention includes the article transport vehicle10that conveys an article between manufacturing facilities and the rail assembly20that provides a travel path of the article transport vehicle10.

The rail assembly20includes a yoke210installed along the travel path, side guide rails220A and220B installed on a lower inner surface of the yoke210, and linear motor magnets230A and230B installed at upper portions of the side guide rails220A and220B. The yoke210includes a horizontal portion210A and a pair of vertical portions210B, each vertical portion of the pair of vertical portions210B being connected to a corresponding end of the horizontal portion210A. The side guide rails220A and220B are installed at a lower inner surface of each vertical portion of the pair of vertical portions210B of the yoke210. The linear motor magnets230A and230B are installed at an upper surface of the side guide rails220A and220B.

The article transport vehicle10includes an article holder110that provides a space in which the article is accommodated, a vehicle body120that is rotatably coupled above the article holder110, magnetic levitation actuators130A and130B that are installed at the vehicle body120and control a gap to the side guide rails220A and220B by generating attractive force on the side guide rails220A and220B, and linear motor coils140A and140B that generate a driving force by interacting with the linear motor magnets230A and230B. In an embodiment, the article holder110may accommodate an FOUP storing wafers or substrates to be transferred and protect the wafers from external impact, for example. The article holder110may be referred to as an FOUP holder. The linear motor magnets230A and230B include recesses toward the lower inner surface of the yoke210.

The rail assembly20provides the travel path for traveling of the article transport vehicle10and may be installed on the ceiling of the manufacturing plant.

The side guide rails220A and220B are configured to interact with the magnetic levitation actuators130A and130B that perform levitation and posture control of the article transport vehicle10. The linear motor magnets230A and230B are configured to interact with the linear motor coils140A and140B that generate a driving force of the article transport vehicle10. Each of the side guide rails220A and220B has rectangular shape having inner vertical surface and lower horizontal surface.

The rail assembly20may include an upper guide rail240installed at the center of the yoke210. The upper guide rail240is attached to a center of a lower surface of the horizontal portion of the yoke210. The upper guide rail240is configured to interact with a gravity compensation actuator150for levitation of the article transport vehicle10. As illustrated inFIGS.7to10, the upper guide rail240is configured to be branched in the traveling direction in a branch area of the travel path. The upper guide rail is branched into two directions including a straight direction and a curved direction. For reference,FIG.7to10illustrate a branch traveling process of the article transport vehicle10when viewed from the top in the branch area of the travel path.

The article transport vehicle10may travel along the travel path formed by the rail assembly20.

The article holder110may be configured to protect the article being conveyed from an external object by forming a space for accommodating the article in the article holder110. Based on the traveling direction of the article transport vehicle10, the left and right sides of the article holder110may be opened so that the article may slidably move. Structures for protecting the article may be provided in the front and rear of the article holder110. Electronic devices (for example, a camera, a distance sensor, a reader) necessary for traveling of the article transport vehicle10can be installed in front and rear of the article holder110.

Meanwhile, the article holder110is coupled to the vehicle body120by a rotation mechanism115, and the rotation mechanism115couples the article holder110on the lower side and the vehicle body120on the upper side to be rotatably with each other. The article holder110and the vehicle body120can rotate around the rotation axis formed by the rotation mechanism115. That is, a direction in which the vehicle body120is directed and a direction in which the article holder110is directed may be different from each other, which enables smooth traveling during curved traveling of the article transport vehicle10as illustrated inFIGS.9and10described later.

The vehicle body120is a vehicle body for traveling of the article transport vehicle10, and a drive device for driving, and a device for communication and control may be installed at the vehicle body120. As described above, the vehicle bodies120may be provided in front and rear of the article transport vehicle10, respectively. The vehicle body120may transport the article by supporting the article holder110at the top through the rotation mechanism115.

According to the embodiment of the present invention, the vehicle body120may include a base plate122that is provided in a predetermined shape and is rotatably coupled to the article holder110through the rotation mechanism115, and side bars124A and124B formed on both sides of the base plate122. As illustrated inFIG.2, the base plate122may be coupled to the article holder110through the rotation mechanism115, and the side bars124A and124B may be installed on the upper left side and the upper right side of the base plate122, respectively. The base plate122and the side bars124A and124B may be integrally configured or may be assembled after individual production.

Referring toFIG.2, first side bar124A and second side bar124B are erected from an upper surface of the base plate. The first side bar124A includes a vertical bar124Aa extending in a vertical direction perpendicular to an upper surface of the base plate122and a horizontal bar124Ab extending in a horizontal direction parallel to the upper surface of the base plate122outwardly from an upper end of the vertical bar124Aa. Similarly, the second side bar124B includes a vertical bar124Ba extending in a vertical direction perpendicular to an upper surface of the base plate122and a horizontal bar124Bb extending in a horizontal direction parallel to the upper surface of the base plate122outwardly from an upper end of the vertical bar124Ba. The second side bar124B is erected from the upper surface of the base plate122and spaced apart from the first side bar124A in the horizontal direction.

The rotation mechanism115rotatably connects a lower surface of the base plate122to the article holder110.

Additionally, the vehicle body120may further include a vertical rotation shaft126that extends upward from the center of the base plate122. A gravity compensation actuator150that is formed at the upper portion of the vertical rotation shaft126and generates attractive force corresponding to the load of the article transport vehicle10may be provided. Branch auxiliary actuators160A and160B that assist the steering of the article transport vehicle10may be provided on both sides of the gravity compensation actuator150.

The magnetic levitation actuators130A and130B apply an electrical signal to the coil to generate attractive force by an interaction with a magnetic body such as an electromagnet.

The magnetic levitation actuators130A and130B may control the gap to the side guide rail220by generating attractive force on the side guide rail220installed along the travel path of the article transport vehicle10. The magnetic levitation actuators130A and130B may interact with the side guide rail220to generate attractive force. With reference toFIG.2, the magnetic levitation actuators130A and130B may be provided on the left and right sides of the traveling direction of the article transport vehicle10.

According to the embodiment of the present invention, the horizontal magnetic levitation actuators130A and130B may include first horizontal magnetic levitation actuators134A and134B that are installed adjacent to lower portions of the side guide rails220A and220B on both sides of the base plate122and control the gap with the side guide rails220A and220B in a vertical direction, and second horizontal magnetic levitation actuators132A and132B that are installed adjacent to sides of the side guide rails220A and220B on outer sides of the side bars124A and124B and control the gap with the side guide rails220A and220B in a horizontal direction. The first horizontal magnetic levitation actuators134A and134B are attached at a side surface of the base plate. The second horizontal magnetic actuators132A and132B are attached at the upper surface of the base plate122and disposed at a region defined by the vertical bars124Aa and124Ba, the horizontal bars124Ab and124Bb, the upper surface of the base plate122.

With reference toFIG.2, the second horizontal magnetic levitation actuators132A and132B may be provided on the outer sides of the side bars124A and124B, and the first horizontal magnetic levitation actuators134A and134B may be provided on both sides of the base plate122. The second horizontal magnetic levitation actuators132A and132B may uniformly maintain the gap between the article transport vehicle10and the side guide rails220A and220B by evenly generating attractive force on the side guide rails220A and220B. Although not illustrated, a gap sensor that detects a horizontal (X-direction) gap between the article transport vehicle10and the side guide rails220A and220B may be provided, and attractive force of the second horizontal magnetic levitation actuators132A and132B may be controlled in response to the horizontal distance measured by the gap sensor.

The first horizontal magnetic levitation actuators134A and134B may generate attractive force corresponding to the load of the article transport vehicle10with respect to the side guide rails220A and220B. Similarly, a gap sensor that detects a vertical (Z-direction) gap between the article transport vehicle10and the side guide rails220A and220B may be provided, and attractive force of the second horizontal magnetic levitation actuators132A and132B may be controlled in response to the vertical distance measured by the gap sensor.

That is, the magnetic levitation actuators130A and130B may perform vertical levitation and horizontal position control of the article transport vehicle10.

In addition, the magnetic levitation actuators130A and130B may selectively generate attractive force on the side guide rails220A and220B in accordance with the traveling direction in which the article transport vehicle is to travel in the branch area of the travel path. For example, when the article transport vehicle intends to travel in the right direction in the branch area as illustrated inFIG.5, the right magnetic levitation actuator130B is activated to generate attractive force to the right side guide rail220B. Since the left magnetic levitation actuator130A is deactivated, the article transport vehicle10can move along the right side guide rail220B. With reference toFIGS.7and8, when the article transport vehicle travels in a straight direction (right direction) in the branch area, the right magnetic levitation actuator130B is activated to generate attractive force to the right side guide rail220B, and thus the article transport vehicle10can travel in the straight direction. That is, the magnetic levitation actuators130A and130B are configured to generate attractive force based on a travel direction of the article transport vehicle10.

In addition, when the article transport device intends to travel in the left direction in the branch area as illustrated inFIG.6, the left magnetic levitation actuator130A is activated to generate attractive force to the left side guide rail220A. Since the right magnetic levitation actuator130B is deactivated, the article transport vehicle10can move along the left side guide rail220A. With reference toFIGS.9and10, when the article transport vehicle travels in a curved direction (left direction) in the branch area, the left magnetic levitation actuator130A is activated to generate attractive force to the left side guide rail220A, and thus the article transport vehicle10can travel in the straight direction.

The linear motor coils140A and140B may generate a driving force for traveling by an interaction with the linear motor magnets230A and230B. The linear motor coils140A and140B extend in the horizontal direction from the side surface of the horizontal bars124Aa and124Ba of the vehicle body120.

According to the embodiment of the present invention, the linear motor coils140A and140B may be configured to be fixed to the outsides of the side bars124A and124B and inserted into a recess recessed in the linear motor magnet230at a predetermined distance. With reference toFIG.4, the linear motor coils140A and140B are installed to be fixed to the outer horizontal surfaces of the side bars124A and124B, and the protruding portions of the linear motor coils140A and140B may be inserted into a recess recessed in the linear motor magnet230B. The linear motor coils140A and140B and the linear motor magnets230B may be designed to maintain a constant gap.

That is, the linear motor coils140A and140B generate a driving force for traveling of the article transport vehicle10.

According to the embodiment of the present invention, the magnetic levitation actuators130A and130B may selectively generate attractive force on the side guide rails220A and220B in accordance with the traveling direction in which the article transport vehicle is to travel in the branch area of the travel path.

According to the embodiment of the present invention, the vehicle body120in the article transport vehicle10may further include the vertical rotation shaft126that is coupled with the rotation mechanism115and extends over the base plate122. With reference toFIG.2, the vertical rotation shaft126is configured to extend in the vertical direction (Z-direction) from the rotation shaft of the rotation mechanism115. The vertical rotation shaft126is erected from the upper surface of the base plate122. The vertical rotation shaft126is connected to the rotation mechanism115.

According to the embodiment of the present invention, the article transport vehicle10may further include the gravity compensation actuator150that is formed at an upper portion of the vertical rotation shaft126and generates attractive force to the upper guide rail240installed at an upper portion of the yoke210installed along a movement path of the article transport vehicle10. The gravity compensation actuator150may generate attractive force corresponding to the load of the article transport vehicle10by the interaction with the upper guide rail240. The gravity compensation actuator150is disposed at an upper end of the vertical rotation shaft126.

The rail assembly20may further include a pair of branch guide rails250A and250B installed on one sides of the traveling direction in the branch area, respectively. The pair of the branch guide rails250A and250B are installed at the lower surface of the horizontal portion of the yoke210and extending downwardly from the lower surface of the horizontal portion210A of the yoke210. The pair of the branch guide rails250A and250B are adjacent to opposite sides of the upper guide rail240.

The article transport vehicle10may further include the branch auxiliary actuators160A and160B that are provided on both sides of the gravity compensation actuator150and selectively generate attractive force on the branch guide rails250A and250B installed on one sides of the upper guide rail240in accordance with the traveling direction in the branch area of the travel path. The branch auxiliary actuators160A and160B are provided on opposite sides of the gravity compensation actuator150.

The branch auxiliary actuators160A and160B determine the traveling direction of the article transport vehicle10in the branch area, together with the magnetic levitation actuators130A and130B.

For example, when the article transport vehicle10intends to travel in the right direction as illustrated inFIG.5, the right magnetic levitation actuator130B is activated to generate attractive force on the right branch guide rail250B. With reference toFIGS.7and8, when the article transport vehicle10intends to travel in the straight direction (right direction), the right branch auxiliary actuator160B is activated together with the right magnetic levitation actuator130B to allow the article transport vehicle10to travel in the straight direction.

In addition, when the article transport vehicle10intends to travel in the left direction as illustrated inFIG.6, the left magnetic levitation actuator130A is activated to generate attractive force on the left branch guide rail250A. With reference toFIGS.9and10, when the article transport vehicle10intends to travel in the curved direction (left direction), the left branch auxiliary actuator160A is activated together with the left magnetic levitation actuator130A to allow the article transport vehicle10to travel in the curved direction (left direction).

It will be apparent that the present embodiment and the drawings attached to this specification just clearly represent a part of the technical spirit included in the present invention, and all modification examples and specific embodiments that can be easily inferred by those skilled in the art within the scope of the technical spirit contained in the specification and drawings of the present invention are included in the scope of the present invention.

Therefore, the spirit of the present invention should not be limited to the described embodiments, and not only the claims to be described later, but also all those that have equal or equivalent modifications to the claims will be said to belong to the scope of the spirit of the present invention.