CLAIM OF PRIORITY The present application claims priority under 35 U.S.C. § 119(e) from U.S. Provisional Patent Application No. 60/906,972, filed Mar. 14, 2006, and U.S. Provisional Patent Application No. 60/873,892, filed Dec. 8, 2006, which are incorporated by reference in their entirety for all purposes.
BACKGROUND The present invention generally comprises an isolation system for storing and handling workpieces. More particularly, the present invention comprises a container for storing flat panel display substrates and a storage system for operating with the container.
Increasing the quality and manufacturing yield of liquid crystal displays (LCDs) used in manufacturing flat panel displays (FPDs) is a challenging process. Adding to this challenge is the dramatic increase in glass size as large and wide-screen televisions become more and more popular. Because picture quality is a major competitive differentiator in the marketplace, FPD manufacturers must affordably test all panels with sure defect detection, while decreasing test time and increasing quality and yield.
Yields for large area FPDs are negatively impacted due to damage to glass panels that is attributable to particle contamination. This problem has become more acute as panel sizes have increased and pattern dimensions have decreased.
There are no known sealed containers for FPDs, because in part of the size of the FPDs. Accordingly, there is a need to provide environmental isolation to reduce contamination of FPDs during processing.
SUMMARY One aspect of the present invention is to provide a system that isolates the FPD substrates from contamination during processing. In one embodiment, the system includes a load port having a load port door comprising a retractable flexible material. In one embodiment, the flexible material retracts into a pocket or zone located above the load port. In another embodiment, the flexible material retracts into a pocket or zone located below the load port. It is also within the scope of the invention for the material to retract into a side pocket or zone or a pocket or zone located above a container seated on the load port. The load port door may also retract onto a roller.
Another aspect of the present invention is to provide a container for preventing or minimizing damage to the substrates stored in the container. In one embodiment, the container includes a door comprising a retractable flexible material. The flexible material may comprise any material such as, but not limited to, plastic, polymers, and stainless steel foil. Any suitable non-shedding flexible material compatible with the operations and capable of the repeated bending and stresses of opening and closing may be utilized here. In one embodiment, the flexible material retracts into a pocket located in an upper region of the container. In another embodiment, the flexible material retracts into a pocket located in a lower region of the container. It is also within the scope of the invention for the material to retract into a side pocket.
Yet another aspect of the present invention is to provide an environment of clean filtered air or gas for FPD substrates during manufacturing cycle including storage, transport, tool loading, and inspection. In one embodiment, the container and/or load port may also regulate environmental conditions such as ionization, humidity and temperature.
Still another embodiment of the present invention is to transport a container throughout the fabrication facility and position the container on the load port. In one embodiment, the container includes wheels. The wheels may comprise passive or motorized wheels. In another embodiment, a belt conveyor or wheel type conveyor moves the container throughout the facility and positions the container on the load port. In another embodiment, the container includes a plurality of lift points whereby a mechanism (e.g., AGV, etc.) may lift the container.
Other aspects and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS Aspects of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.
FIG. 1 illustrates a substrate container, a tool loading mini-environment, and a processing tool (e.g., manufacturing tool, measurement tool, etc.) in accordance with one embodiment of the invention.
FIG. 2 illustrates a perspective view of a container in one embodiment.
FIGS. 3 and 4 illustrate a container having a slotted door.
FIGS. 5A and 5B illustrate one embodiment of a flexible door that could be pulled towards the container frame at the end of closure to minimize sealing gaps.
FIG. 6 is a simplified schematic diagram illustrating a container with a flexible membrane door in another embodiment.
FIGS. 7A and 7B illustrate another configuration of the container in accordance with one embodiment of the invention.
FIG. 8 illustrates another embodiment of a substrate container.
FIG. 9 illustrates the container door located in an open position.
FIGS. 10A-10B illustrate that a container may include a clean air-flow system.
FIG. 11A illustrates one embodiment of an FPD delivery system.
FIG. 11B illustrates the port door 192 and container door located in an open position.
FIG. 12 illustrates one embodiment of a container transport and loading system.
FIGS. 13-15 illustrate that the flexible door retracts into a bottom pocket.
FIG. 16 illustrates an embodiment of how the pulleys may be connected by a common shaft 206 in order to synchronize the pulley drive system.
FIGS. 17-18 show a container in a docked position.
FIGS. 19A, 19B, 20A, and 20B illustrate another embodiment of a substrate transfer system.
FIGS. 21A-21B illustrate another embodiment of a substrate transfer system.
FIGS. 22A and 22B illustrates substrates stored in a container in a non-planar configuration.
FIGS. 23-24 illustrate one embodiment of a container having a movable seal.
FIG. 25 is a simplified schematic diagram illustrating a storage/shipping container for large area substrates that minimizes resonance or vibration of the substrate in accordance with one embodiment of the invention.
DETAILED DESCRIPTION An invention is described for a system and apparatus for large area substrates such as flat panel display substrates. It will be obvious, however, to one skilled in the art, that the present invention may be practiced without some or all of these specific details. In other instances, well known process operations have not been described in detail in order not to unnecessarily obscure the present invention.
The present invention generally comprises a system for FPD material storage and transport. The FPD system may contain environmental protection, material tracking and/or workstation loading capabilities. One of the components of the system includes a transportable, sealable container. Another component of the system includes a sealable load port against which a container is docked so that the substrates may be processed.
FIG. 1 illustrates a substrate container, a tool loading mini-environment, and a processing tool (e.g., manufacturing tool, measurement tool, etc.) in accordance with one embodiment of the invention. Container 1, as shown in FIG. 1, stores the FPD substrates in a substantially horizontal orientation within the container. In FIG. 1, container 1 is located in a load position in front of the mini-environment 100. The container 1, in this embodiment, comprises a closed enclosure except for the front opening, which is sealed with a retractable flexible membrane 3 (also referred to herein as a container door or shield). By way of example only, the flexible membrane 3 may be retracted over rollers, that may or may not be segmented, or wheels, to allow access to the substrates therein. Other devices for retracting the membrane are within the scope of the present invention. It is possible that the membrane will not be in physical contact with the periphery of the front opening at all places, having a small gap that allows the membrane to be retracted without abrasion in one embodiment. In another embodiment, this gap is minimized or eliminated as will be explained in more detail hereinafter.
The container support mechanism 101 that the container 100 is seated on may comprise a mechanism that moves the front face of the container to the proximity of the front opening of the mini-environment 100 (e.g., similar to a front opening unified pod (FOUP) advance plate of a conventional load port) or the container may be initially loaded on the support mechanism at the position shown in FIG. 1. In this load position, the container door is preferably proximate to the front door of the mini-environment to create a proximity seal between the two doors. In any event, once the container 1 is located in this load position, both the container door 3 of the container and the front door of the mini-environment 100 may be opened, allowing the FPD substrates to be accessed by the transfer mechanism 106 within the mini-environment. In one embodiment, the motion of both doors is synchronized to open and close together, as described below. It should be appreciated that door 108 of mini-environment 100 may be a retractable flexible membrane similar to door 3 in one embodiment. This synchronized door motion would minimize particulate contamination as the exterior, and potentially contaminated, surface of either door will not be exposed to the open volume of the container or the mini-environment. It is within the scope and spirit of the present invention for the process tool 102 to not include a mini-environment in one embodiment. In this case, the container front door (or membrane or shield) would be placed proximate to the panel handling system door or access zone of the process tool 102.
The front door 108 of the mini-environment may also couple with the container door before raising the doors 3 and 108 in unison. Coupling the doors 3 and 108 together will “trap” particles located on the exterior surface of both doors between the container door 3 and the front door 108—similar to a conventional port door coupling with a FOUP door. The front door 108 may couple with the container door 3 at any elevation. In one embodiment, front door 108 and container door 3 couple together near the bottom portion of each door. The container door 3 is configured to be able to be raised to a position whereby the workpiece stored in a top shelf of the container is accessible by the substrate handling robot 106.
When the container door 3 and mini-environment doors 108 are both open, there may be a small gap between them that is exposed to the outside environment. To prevent contaminants from the outside environment from entering the container or mini-environment 100, the mini-environment may include a fan and filter unit 104 that provides clean air to the inside of the mini-environment, creating an internal pressure within the mini-environment that is slightly higher than ambient or external pressure. This pressure difference would force clean air out of the mini-environment 100 through the gap and prevent contamination from the outside. Alternatively, the mini-environment 100 or tool 102 might not include a fan and filter, and instead rely on a clean air flow provided by the optional fan/filter unit 110 in the container 1. As mentioned above, the door on the mini-environment (or tool if no mini-environment is used) may be a rolling membrane as on the container (and shown in drawing) or the door may be a more conventional rigid door that slides vertically to open and close. It is also possible that the gap may be sealed after the doors are opened by advancing the container 1 until the container seals against the mini-environment 100.
It should be appreciated that there are various ways that power or a motive force (e.g., mechanical force) could be provided to the container door mechanism and the optional fan and filter system. By way of example only, power could be supplied to the container by:
a.) A portable energy storage device on the container (e.g., battery, super cap, fuel cell, etc.);
b.) Electrical contacts at the loading station;
c.) Non-contact power that is transmitted by electromagnetic field from stationary conductors at the load station to pick-up coils and circuits on the container;
d.) Pneumatic ports at the loading station that provide pressurized gas; and/or
e.) a mechanical linkage that mates with the container when it is at the loading station.
Power sources b), c), d) or e) may be directly controlled at their source outside of the container to control the container door motion, or for example, the actuations/control of the fan and filter unit, or a control signal could be provided at the load station to control the timing of the container door motion or actuation/control of the fan filter unit. There are a number of ways that the control signal(s) could be communicated to the container including, but not limited to, an optical link light emitting diode (LED) and photosensor or electrical contacts at the load station or radio frequency signals.
FIG. 2 illustrates a perspective view of a container in one embodiment. Container 1 has a front opening 14 through which substrates are passed. A moveable door 3 is made from a flexible material which rolls over roller 2 during opening and closing of the door. The lower and upper ends of the door are terminated with bars 4 and 5 respectively. Bars 4 and 5 allow a uniform tension to be maintained across the width of the door. The ends of terminating bars 4 and 5 may be supported by guides or slides (not shown) that keep the bars (and in turn the membrane door) at a fixed distance from the container body during door motion. Each end of each bar is connected to the end of a timing/synchronizing belt. Belt 7 is attached to bar 5, then rolls over pulleys 8, 9, and 10 before attaching to terminating bar 4. In a similar way, belt 6 is attached to the other end of terminating bar 5 and rolls over 3 pulleys on the other side of the container (including pulleys 11 and 12) and is then connected to the other end of bar 4. Shaft 15 connects pulleys 8 and 11 so that the movement of belts 6 and 7 is synchronized. The other pulleys would freely rotate without cross shafts. It should be appreciated that in one embodiment, belts 6 and 7 may proceed diagonally across a side surface of container 1 rather than around an entire periphery. In this manner, one of the pulleys on each side may be eliminated.
One concern would be the particles that could attach to the inside of the door 3 while the door is open or during the opening motion. These particles may subsequently detach from the inside of the door 3 after the door is closed and contaminate the substrates stored in the container 1. There are several ways in which this potential particle problem could be reduced. If a fan and filter was installed on the container 1, and the upper container surface 13 had perforations or other openings (e.g., slots, micro-pores, etc.), then clean air would flow out of the container through the perforations. This clean air flow would keep particles from depositing on the upper surface of the container 1 where the particles could be transferred to the inner surface of the door 3 when the door is open. The clean air would also flow over the inner surface of the door 3 when the door is open.
Another area of concern is particle generation and transfer at the interface between the flexible door 3 and the roller 2. Particle generation could be mitigated by reducing the contact between the roller 2 and the door 3. The roller 2 may, for example, have narrow ridges down its length or raised bumps to reduce contact area between the roller 2 and the door 3. Alternately, the inside surface of the door 3 could have the ridges or bumps to reduce contact area. The container door 3 may be opened and closed by various mechanisms. Lower terminating bar 4 could engage a vertical drive mechanism on the mini-environment or tool. The vertical drive mechanism would raise to open the container door 3 and lower to close the container door without any need for a powered actuator on the container. Alternately, an electric motor may be coupled to the shaft 15, the end of roller 2, or any of the timing belt pulleys. Rotational motion of the motor would rotate the corresponding shaft, roller or pulley and move the linked system of timing belts and door. Similarly, a linear actuator (e.g., pneumatic device) could be connected to the door 3 or belts 6 or 7 to provide door motion. Any other suitable mechanism for raising or lowering doors is within the scope of the present invention. The door 3 shown in FIG. 2 moves over a roller 2. It is within the scope of the invention for the container to have a frame including a docking interface that encompasses the roller 2 (as shown in FIG. 6).
FIGS. 3 and 4 illustrate a container having a slotted door. Door 3 includes upper door section 17 and lower door section 19, which are respectively terminated at bar 4 and bar 16, defining slot opening 18. Bars 4 and 16 are linked at each end to allow motion to be transmitted to both door sections 17 and 19 with one drive. Lower door section 19 rolls over roller 20 and ends at terminating bar 21. As the timing belts 6 and 7 are moved, slot 18 will move up and down with the belts, allowing access to a single storage position in the container. It is within the scope of the invention for the slot 18 to be large enough to provide access to more than one substrate stored in the container 1. The slot 18 could also be formed by an aperture cut into a single piece of flexible material or could be formed by an aperture plate, i.e., a single plated with an aperture, attached to the flexible material of door 3. In the embodiments of FIGS. 3 and 4, the membrane door indexes to the location of the substrate being removed and thus, the door will remain in front of the support elements and the aperture allows access to one or more support elements or substrates.
The slotted door container of FIGS. 3 and 4 may have the same features for bar guides, particle reduction, and drive mechanism as the container shown in FIG. 2. The bottom surface may also have clean air flow holes to improve the cleanliness of the lower door segment. A vertical drive mechanism on the mini-environment or tool may engage bars 4 or 16 to move the slot to different positions as the substrates are accessed for processing. FIG. 3 illustrates the container 1 including an optional fan 110 and filter unit 112. The fan 110 and filter unit 112 may provide enough clean airflow to assure that particles from the outside environment would not migrate through the slot 18 into the container. In addition, the container 1 may include a walled area comprising a portion of the front opening of the container 1. When the slot 18 is moved to cover the wall 109, the container opening is effectively “closed”. The wall in the container opening may be located at any elevation. FIG. 3 illustrates one embodiment whereby the barrier or wall is located in the top section of the container opening 14. When the container door is raised until the slot 18 is located over the wall 109, the lower portion of the door 19 covers the entire container opening 14. The port door of the mini-environment, or processing tool, may likewise include a movable door with a single slot. In this case, once the container is seated in the loading position, the port door would preferably move in unison or be indexed in unison with the container door so that the port door is aligned with the slot in the container door. In another embodiment, the port door may also comprise a door similar to a conventional port door.
FIGS. 5A and 5B illustrate one embodiment of a flexible door that could be pulled towards the container frame at the end of closure to minimize sealing gaps. In this embodiment, that the container includes a moveable roller assembly 25. The roller assembly 25 includes a roller 2, a pivot arm 26, a pivot bearing 27, a roller tension spring 28, a spring attachment feature 29 and stop block 31. The pivot arm 26 is held against the stop block 31 until a force vector that is perpendicular to the long axis of the pivot bar exceeds the spring tension of spring 28. The pivot arm 26 will then pivot at the pivot bearing 27 and separate from the stop block 30. The tension spring force is preferably greater than the belt tension and any frictional forces resulting from door closure. In one embodiment, closing the container door and sealing the container door against the block 31 is accomplished through a single motion. It is also within the scope of the invention for the roller assembly to include a slide bearing assembly.
It should be appreciated that the drive system in FIG. 5A may be similar to the drive in FIG. 2. The drive system includes timing belt 7, pulleys, and the door is terminated in upper bar 5 and lower bar 4. FIG. 5A shows slides 22 and 26 which are connected to bars 5 and 4 respectively, and provide sliding support. Belt spring 23 has been added to maintain belt tension within a useful range when the door has moved towards the container front. This motion effectively reduces the belt/door perimeter distance and the spring 23 keeps the corresponding belt from becoming slack. When the belt and door are moved in the direction to lower the door, upper bar 5 will strike end block 24 as the slide support for bar 4 enters the recessed slide profile 31. The recessed slide profile is a section of the slide that is slightly angled towards the front of the container so that bar 4 moves along its guide path, and the end of the door moves toward the container. While bar 4 is moving through the recessed slide profile, bar 5 is immobile against the end stop, increasing force on the roller until the roller assembly pivots toward the end block. The pivoting of the roller assembly in combination with the motion of bar 4 through the recessed slide profile moves all surfaces of the door (below the roller) towards the container, thus minimizing gaps. There may also be a retention mechanism to prevent the bar 4 from moving upward due to the force of the roller tension spring displacement once the door has been closed.
The drive belts may be replaced by any similar flexible coupling such as a cable, cord, v-belt, flat belt or band. The moveable roller in FIGS. 5A and 5B could have a linear, rather than pivoting, motion. The pulleys 8-10 could be placed in different locations and the belt 7 follow a different path as long as they remain connected to the 2 end of the flexible door. The flexible door material could roll up on a torsionally sprung roller the way that a window shade works.
FIG. 6 is a simplified schematic diagram illustrating a container with a flexible membrane door in another embodiment. Container 1, includes a docking interface 150 that is configured to accept a drive pin in one embodiment. The drive pin may engage with docking interface 150 and latch therewith either by rotating or some other suitable mechanism. Container 1 includes fan filter assembly 110 and membrane door 3. In one embodiment, a key may be used as the drive pin and may be used to lock or unlock the flexible membrane door so that the door may be secured for locking or lowered or raised when unlocked. In one embodiment, the key stays captured with the container, such as a rotating latch with integrated retention means.
FIGS. 7A and 7B illustrate another configuration of the container in accordance with one embodiment of the invention. In FIGS. 7A and 7B membrane door 3 is configured to roll or wrap around shafts 154 and 156. Membrane door 3 may include bumps 158 or protrusions in order to minimize the contact of the membrane door with itself as the door is rolled around the shaft.
FIG. 8 illustrates another embodiment of a substrate container. The container includes a container shell, forming an enclosure, comprising a first side wall, a second side wall, a rear wall, extending from a bottom wall or base and a top wall. The container shell shown in FIG. 8 includes a front opening through which substrates are passed. Unlike a FOUP, the container door comprises a flexible material. The container door may comprise any suitable material that is compatible with the process and clean room environment and capable of withstanding the bending induced through repeated openings and closings. Exemplary material includes polyester films, synthetic fluoropolymers, fiber reinforced polyester films and fiber reinforced synthetic fluoropolymers stainless steel foils, etc. In one embodiment, the container door may have conductive properties to avoid static charging.
FIG. 8 illustrates the container door 3 in a closed position. In this embodiment, the container also includes a base disposed along a bottom surface. As will be discussed in more detail later, the container door 3 may retract into a top portion of the container shell or a side portion of the container shell to provide access to the substrates stored in the container 1.
FIG. 9 illustrates the container door located in an open position. The container top wall and side panel have been removed in FIG. 9 for illustration purposes. In this embodiment, the container door 3 retracts into the top zone (e.g., along inner top wall of container, along outside of top wall of containers, etc.) of the container shell. For example, the container door 3 may retract into a pocket in the top wall of the container shell or into a top portion of the container proximate the top wall of the container shell. Regardless, in this embodiment, the container door 3 travels over a roller spanning across the top of the front opening. As shown, the container door 3 bends at approximately at a right angle as the container door travels over the roller, necessitating a flexible material. It is within the scope of the present invention for the container to include more than one roller to guide the container door. For example, the container 1 may include a pair of rollers spaced apart from each other at a forty-five degree angle to reduce the severity of the bend in the container door. Air inlet plenum 170 allows air to enter the area where door 3 is retracted, while exhaust plenums may be defined along the sides of the top surface.
FIG. 9 illustrates that the lower and upper ends of the container door are terminated with guide bars. These guide bars allow a uniform tension to be maintained across the width of the door 3 at all times. The ends of the guide bars may be supported by guides or slides (not shown) that keep the bars at a fixed distance from the container body during door motion. In this embodiment, each guide bar is connected to two timing/synchronizing belts. The belt 6 shown in FIG. 9 is attached at one end to a guide bar, then travels downward along the side of the front opening, over a pulley, then diagonally rearward up to the top back corner of the side panel, and over a second pulley before attaching at the other end to the other guide bar. The belt attached to the other end of each guide bar travels through a similar set of pulleys. The pulleys 8 and 11 are connected by a shaft so that the movement of the belts is synchronized. The other pulleys may freely rotate without cross shafts.
FIGS. 10A-10B illustrate that a container may include a clean air-flow system. In this embodiment, the container includes an air inlet plenum 170, air outlet plenums and multiple clean air blowers 110. The blowers 110 pull outside air into the container to create a flow of clean air within the container. FIG. 10B illustrates that a diffuser screen 180 may be placed between the plenum and the blowers. The blowers 110 create clean airflow into the container. This creates a slightly higher pressure of clean air in the container. The air will flow out of the proximity seal formed by the container door and other vents that may be designed to sweep particles away from contaminating surfaces such as rollers and bearings. The space between the blower panel and the diffuser screens 180 is the plenum, which allows the pressure to be more evenly distributed before the air exits the plenum and enters the container. In other words, the “plenum outlet” is the outlet feeding the interior of the container. If space was allocated for a plenum the filter elements may be arranged differently as they would be in a mini-environment, i.e., the blowers would pressurize the plenum volume and the filters would be in the place shown as the diffuser screens. That way the filters would benefit from the even pressure of the plenum and provide non-turbulent airflow. It is possible that filters could be almost directly attached to the blowers, producing a flow of air that is clean but may be somewhat turbulent to save the space and still provide a clean pressurized interior for the container.
FIG. 11A illustrates one embodiment of an FPD delivery system. Here, the delivery system includes a mini-environment 100 containing an FPD handing robot 106. The mini-environment 100 generally functions as a clean transfer chamber allowing the FPD handling robot 106 to remove an FPD substrate or panel from a container and subsequently transfer the substrate to a processing tool or another container without contaminating the substrate. In this embodiment, the mini-environment includes a port door 192 and a door containment chamber 190 or zone. The door containment chamber 190 is located above the mini-environment 100 such that the port door 192 travels upward into the chamber. The door containment chamber 190 may also be located to either side of the mini-environment. FIG. 11A further illustrates the port door located in a closed position. As will be discussed in more detail later, the container may be seated on a load port.
FIG. 11B illustrates the port door 192 and container door located in an open position. The port door is raised into the door chamber 190, which is a clean environment. The container door has retracted into the top of the container 1. The load port door and the container door may operate in unison or each door may operate on its own. For example, the mini-environment 100 may include a port door drive mechanism for moving the port door between the open and closed position. The container may include a separate drive mechanism for moving the container door between an open and closed position. Alternately, the port door may engage the container door and provide the drive means for moving the container door such that the two doors move in unison. It is also within the scope of the invention for the container door and the port door to move in two different directions. FPD handling robot 106 is inserted into the container. After the mini-environment door and container door are located in the open position, the FPD handling robot may access any of the substrates in the container.
FIG. 12 illustrates one embodiment of a container transport and loading system. Here, a container has been loaded onto the load port of a mini-environment 100, which is connected to a processing tool. The container 1 is moved between a transport system and the load port by belt conveyors. The container is positioned on the load port by belt conveyers in one embodiment. It is within the scope of the invention for the load port and the transport system to use an air bearing system or wheels to move the container 1. The container is shown in the docked position. Rather than include a top handle, the container includes two load points 174 extending from each side of the container whereby a forklift-type device may lift the container. These four lift points distribute the weight of the container on the lifting device. The container may include any number of lifting points and/or other similar features for lifting and supporting the container.
FIG. 13 provides a rendition of a processing tool or mini-environment having a load port, and a container seated on the load port. FIG. 13 illustrates a single load port, however, it is within the scope of the invention for a processing tool or mini-environment to have multiple load ports. The multiple load ports may be stacked vertically or arranged horizontally. In this embodiment, the container door retracts into the bottom of the container shell. For example, the container door may retract into a pocket 204 in the bottom wall of the container shell or into a bottom portion of the container proximate the bottom wall of the container shell. Regardless, in this embodiment, the container door travels over a roller 200 spanning across the bottom of the front opening. It is within the scope of the present invention for the container to include more than one roller 200 and 202 to guide the container door. For example, the container may include a pair of rollers spaced apart from each other at a forty-five degree angle to reduce the severity of the bend in the container door. The upper and lower edge of the container door is terminated with a guide bar. These guide bars allow a uniform tension to be maintained across the width of the flexible door at all times. The ends of the guide bars may be supported by guides or slides (not shown) that keep the bars at a fixed distance from the container body during door motion. As will be explained later, the flexible door is driven by a drive mechanism. FIG. 13 illustrates an embodiment of a drive mechanism for moving the flexible door between an open and closed position as well as an air exhaust feature of the container. In this embodiment, the container door drive mechanism includes a three pulley system located on each side of the container. A first pulley 206 is located at the top, front of the container above the front opening. A second pulley 200 is located at the bottom, front of the container below the container opening. A third pulley 202 is located at the bottom, rear of the container, and is attached at both ends to a guide bar.
Two belts, one attached to each end of a guide bar, move the door between the open position and the closed position. When the door is located in the open position, the belt 205 shown in FIG. 14 is attached at one end to a top guide bar, then travels upward along the side of the front opening, over the first pulley, then back downward along the back face of the container towards the second pulley, under the second pulley and back towards the rear of the container, over the third pulley, and towards the bottom guide bar which the belt is attached to. The belt attached to the other end of each guide bar (on the right die of the container) travels through a similar set of pulleys. The set of first pulleys and third pulleys are preferably each connected by a shaft so that the movement of the each belt is synchronized. The second pulleys are not connected by a common shaft.
FIGS. 13 and 15 best illustrate that the top guide bar is not retracted into the bottom pocket when the container door is located in the open position. The top guide bar instead remains within the front opening facing outward. However, the top guide bar has been lowered below the lowermost substrate so that the top guide bar does not block access to the lowermost substrate (e.g., by a substrate handling robot).
FIGS. 13-15 illustrate that the flexible door retracts into a bottom pocket. This bottom pocket may be part of the container or an additional structure located underneath the container. Retracting the container door in the lower pocket maintains the container door in a controlled environment while the container is open. FIG. 13 illustrates that the air flow within the container allows air to travel into the bottom pocket and out the rear wall of the bottom pocket. The “clean” side of the container door (the side facing the substrates when the container door is closed) is facing upward while the container door is retracted in the bottom pocket. Thus, the air flow in the container travels over the “clean” side of the container door preventing or minimizing particles from contaminating the container door while the container door is in the bottom pocket. The perforated surface in the back wall of the bottom pocket allows the air to travel out of the bottom pocket and back into the ambient environment.
FIG. 16 illustrates an embodiment of how the pulleys may be connected by a common shaft 206 in order to synchronize the pulley drive system. Moving the flexible door in a synchronized manner (e.g., both belts move at same speed) controls the motion of the door to avoid the door from becoming skewed and/or contacting the container.
FIGS. 17-19 illustrate embodiments of a substrate transfer system. The system includes a load port and a mini-environment for accessing substrates stored in a container and transferring the substrates to a processing tool (or another container). The container shown in FIGS. 17-19 includes a container door that opens by retracting into a bottom pocket in one embodiment. The load port includes a conveyor system for advancing and supporting a container on the load port. Here, the conveyor is shown as multiple rollers. However, the conveyor system may also comprise, by way of example only, a belt conveyor.
FIGS. 17-18 show a container in a docked position. The load port includes a container support, a load port door and a drive bar. In this embodiment, the drive bar engages the container door when the container is located in the docked position and the drive bar serves as the drive mechanism for opening/closing the container door. The container support, in this embodiment, does not provide the container advance mechanism similar to a conventional load port. As described above, the container is advanced by the conveyor. The container support may therefore be used to store the load port door. As shown in FIG. 17, the load port door opens by retracting into the container support. The air flow created by either the mini-environment (e.g., from the pressure differential) or from another device that preferably travels into the container support and provides an air flow of clean air over the “clean” side of the load port door (the interior side of the load port door). FIG. 17 illustrates that the mini-environment, the interior of the container and the ambient environment may include different pressures such that the air flow travels as shown in FIG. 18.
FIGS. 19A, 19B, 20A, and 20B illustrate another embodiment of a substrate transfer system. In this embodiment, the transfer system includes a load port having a slide assembly for transferring substrates to a processing tool. The load port shown in FIGS. 19A-20B is similar to the load port disclosed in FIGS. 17-18 whereby the load port door retracts into the container support. Other types of load ports are also within the scope the invention (e.g., the load port door may retract upward or sideways). The load port, in this embodiment, includes a vertical motion slide assembly for transferring a substrate from the container to the processing tool. The load port could comprise a single I/O port or multiple I/O ports. A load port with a single I/O port will be described herein.
FIGS. 19A and 19B illustrates that the assembly includes three supports for supporting the substrate. Of course, the assembly may include any number of supports. FIG. 19 illustrates that the vertical assembly adjusts to align vertically with a substrate stored in the container. Once the assembly and substrate are aligned, the substrate is removed from the container onto the assembly. There are many ways to remove the substrate from the container such as, but not limited to, supporting the substrate by air bearings and allowing the substrate to “glide” from the container to the assembly, supporting the substrate by rollers and activating the rollers to move the substrate from the container to the assembly or supporting the substrate by belts and activating the belts to move the substrate from the container to the assembly. Using air bearings to support and transfer a substrate may require the container supports to be tilted slightly towards or away from the front of the container so that the substrate may glide out of the container. The assembly may also include a mechanical device (e.g., vacuum cup) for gripping a portion of the substrate and pulling the substrate out of the container on the air bearings.
In operation, once the container door and the load port door are open, the assembly may be aligned with any of the substrates stored in the container. A substrate is then removed from the container onto the assembly. If required, the assembly then aligns the substrate with the process tool opening to allow the substrate to be transferred from the assembly to the tool. Once the substrate has been processed, the substrate is transferred back to the assembly, the assembly aligns itself with an empty shelf in the container, and the substrate is transferred back into the container. FIGS. 19A-19B illustrate that it is may be preferable to provide a clean air flow in this transfer zone between the load port and the processing tool to minimize or eliminate particles from contaminating the substrate. The transfer zone may be enclosed or comprise open space within a controlled environment.
FIGS. 21A-21B illustrate another embodiment of a substrate transfer system. The system includes, among other things, a load port (not shown) and a wafer transfer apparatus. The container shown in FIG. 21B stores the substrates in a non-linear or non-planar configuration. Here, the container stores each substrate in a convex configuration. FIGS. 22A and 22B illustrates that a container may also store a substrate in other non-planar configurations, and each substrate is not required to be stored in the container is the same non-planar configuration. In one embodiment, the deflection of each substrate is between 3-4 inches over the length of the substrate or panel. Of course, other deflections are within the scope of the invention. Storing substrates in a non-linear or non-planar configuration adds rigidity to the substrate. The container supports may comprise, by way of example only, rollers, air bearings, pads or belts. Storing the substrate in a non-planar configuration greatly reduces substrate sag and enables simpler support and handling during transfer. The substrates may be intentionally deformed or deflected about its longitudinal centerline or its horizontal centerline. Deformation at the centerline is exemplary and the substrate or flat panel display may be deflected or deformed along any one line or point or multiple lines or points. The deformation is controllable by the location of the support point locations and other forces inflicted upon the substrate.
The transfer apparatus in this system generally comprises an elevator mechanism and a transfer assembly. The elevator mechanism includes a vertical tower or housing having a drive mechanism substantially enclosed in the enclosure to minimize particles generated by the elevator from contaminating the substrate. A transfer assembly is coupled (either permanently or removably attached) to the drive mechanism in the elevator. FIGS. 21A and 21B illustrate the transfer assembly having multiple wheels for supporting the substrate and moving the substrate between and container and a processing tool. As discussed above, the transfer assembly may also support and transfer a substrate with, by way of example only, rollers, air bearings, belts and so on. In a preferred embodiment, the supports on the transfer assembly align with the supports in the container. The transfer assembly may allow the substrate to flatten out or may maintain the substrate in a non-linear configuration. If the substrate is allowed to flatten, the transfer assembly may be required to have an additional third support to properly support the substrate.
The transfer assembly may comprise a horizontally stationary frame or a horizontally adjustable frame. A stationary frame would align vertically with the substrate in the container, and the substrate would be transferred onto the frame. Only the wheels, air bearing, or belts in the container and the transfer assembly would move. Alternately, the frame may be able to move along the Y-axis, allowing the transfer assembly to insert into the container and raise a substrate off a support shelf similar to a conventional end effector.
The elevator mechanism may comprise any height (e.g., to access more than one container with a single elevator mechanism). At a minimum, the transfer assembly includes a vertical range of motion to access each substrate stored in the container. The elevator mechanism may comprise part of the load port or comprise a separate element of the system. Similar to FIGS. 20A and 20B, it is preferable to maintain a flow of clean air through this transfer zone to minimize particles from contaminating the substrate.
FIGS. 22A and 22B illustrates substrates stored in a container in a non-planar configuration. In a conventional wafer container (e.g., FOUP or SMIF pod), each storage shelf comprises two supports; each support being located along one container wall such that the outer side edges of a wafer are supported. Unlike a conventional container, each shelf in the FPD container comprises two or more spaced-apart support members in the container. The horizontal spacing, and vertical displacement of, the support members depends, at least in part, on the type and size of substrate that will be stored in the container. FIGS. 22A and 22B illustrates that one embodiment of the support members will support/generate a convex or concave substrate shape. It is within the scope of the present invention for the container to store a substrate in other alternative configurations (e.g., “S”-shape, etc.).
FIGS. 23-24 illustrate one embodiment of a container having a movable seal. In this embodiment, a movable external frame 400 (with a compliant seal surface) presses the flexible door 3 against the front of the container seal 410 of the container shell (which also has a compliant seal surface), providing a contact seal against the outside environment. In other words, the movable seal frame 400 pushes the flexible door 3 against a fixed seal 404 to effectively seal the container. For example, when the movable seal frame 400 is located in an open position, the frame is approximately 4 mm laterally away from seal 402 of the container frame. When the movable seal frame 400 closes in order to seal the container, the first 2 mm of motion moves the movable seal frame 400 to a position where it contacts the flexible door 3. As the movable seal frame 400 continues its motion towards the container frame, the last 2 mm of motion pushes the container door 3 against container seal 402 of the front surface 410 of the container frame. There is flexibility to the tensioning system of the container door that allows the container door to be pushed forward and slightly distorted. Alternately, when the movable seal frame 400 is located in the open position, a 2 mm gap (or other distance) exists between the movable seal frame and the flexible door 3. Regardless of the exact distance, the movable seal frame 400 and the container door are separated, allowing the flexible door 3 to move to its open position. Here, the flexible door rolls upward into the top zone of the container shell. As discussed above, the flexible door may also move downward or to either side when moving between the open and closed positions.
The actuation of the movable frame can be driven by either a motor 406 or solenoid on the container (or any other motive force), or by an external drive that is coupled to the container when the container is docked against the tool or load port. Here, the external frame is moved between two positions by a linkage mechanism 408. Other mechanisms may be used. FIGS. 23-24 show the flexible door configured to roll upward into the top zone of the container. However, the movable seal would also work if the flexible door was retracted down under the container or sideways around either side wall. FIGS. 23-24 further show the drive system for the flexible door as a motor 406 on the container. It is also within the scope of the invention for such a drive to be external to the container and, for example, couple to the container at the docking position. There could also be additional features that would lock the movable seal and flexible door in the closed position when the container is no longer engaged with a tool or load port, eliminating accidental exposure to the outside environment.
If the flexible door or latch is driven by electrical mechanisms on the container, the mechanisms could get their electrical drive power in various ways. For example, the mechanisms could be coupled through inductive, non-contact transmission while the container is at the docking position or at all positions as it travels from tool to tool. The mechanisms could also receive power transmitted through conductive contact points when the container is docked at the tool or load port. The mechanisms could also receive power from batteries located on the container itself. Other power supplies are also within the scope of this invention.
In the case where the power is supplied to the container while the container is docked at the tool or load port, the actuation mechanism could be driven to its various positions during the course of unloading or loading the container on the load port. The control signals could also be provided to the container to assure that the proper positioning of the mechanisms had been attained before the next motion step (e.g., confirming that the container door is open before a substrate handling robot attempts to access a substrate) or the disengagement of the container from the tool or load port (e.g., confirm that the container door is closed before the container is moved from the load port). Other control signals, such as signals to communicate the status of the actuators as well as to command the actuators, could also be supplied to the container. These control signals (as well as other control signals) could be transmitted to the container through, by way of example only, electrical galvanic contact, inductive non-contact coupling, or through transmission of light (infra-red, ultra violet or visible) between transmitters and detectors. The communications between the container and the tool could be received and processed by a microcontroller on the container. The microcontroller could control the motion of the actuators and/or provide the status signals.
FIG. 25 is a simplified schematic diagram illustrating a storage/shipping container for large area substrates that minimizes resonance or vibration of the substrate in accordance with one embodiment of the invention. Container 1 includes a removable door capable of sealing, latching and retaining substrate 608, also referred to as a wafer, securely within the container. Substrates 608 are loaded onto support members 602. Support members 602 may be referred to as shelves and include independent members, such as rods, tines, planar shelves, tensioned wires or other support elements, etc., and these support members may be cantilevered. In addition, while FIG. 25 illustrates substrates 608 being supported at two locations corresponding to support members 602, any number of locations may be supported depending on the number of support members utilized, the configuration of the support members, e.g., shape and size, the shape and size of the substrates, and the desired deflection points for the substrate. The substrates may be loaded into container 1 through the opening provided by removing the door and the substrates 608 will engage with peripheral support member 600b. In FIG. 25, peripheral support member 600b is illustrated as being lowered from an initial position where the corresponding gripper extensions 604 are substantially planar with a plane defined through a top surface of corresponding support members 602. Once substrates 608 are loaded into container 1, the door is placed onto the container to seal the container through known latching mechanisms available for FOUPs. Peripheral support members 600a and 600b are then driven downward (or upward) to deflect or deform substrates 608 via the contact with gripper extensions 604 of peripheral support member 600b and corresponding recessed surface of peripheral support member 600a. It should be appreciated that peripheral support member 600a may have a gripper extension similar to peripheral support member 600b, and vice-versa, and that the varying configurations are provided to illustrate alternative configurations. The structure for driving the members downward may include a lever inside container 1, such as a door actuated retainer that moves downward as the door is placed onto the container. Other mechanism include a latch key that locks the door and lowers or raises the peripheral support members or other independent means separate from the door. In one embodiment, peripheral support member 600a is attached to an inner surface of the door, while peripheral support member 600b is located on an opposing side of the container. Of course, the peripheral support members may be located on any opposing sides of the container and not limited to the door. In the embodiment of FIG. 25, substrates 608 are deformed to a curvilinear shape, however numerous other shapes are possible dependent on the number and position of the support members 602 and the relative movement of peripheral support members 600a and 600b. While peripheral support members 600a and 600b are illustrated both moving in the same direction, one peripheral support member may be translated upwards, while a second support member is translated downward. It should be appreciated that the deflected shape, e.g., the constrained curved shape of FIG. 25, minimizes shipping/transporting induced vibration and resonance. Substrates 608 may be any geometric shape including but not limited to circular, square, rectangular, or any other quadrilateral shape.
It should be appreciated that the above-described container and isolation systems are for explanatory purposes only and that the invention is not limited thereby. Having thus described a preferred embodiment of a container and system for storing, transporting (which includes shipping) and loading FPDs, it should be apparent to those skilled in the art that certain advantages of the within system have been achieved. It should also be appreciated that various modifications, adaptations, and alternative embodiments thereof may be made within the scope and spirit of the present invention. For example, the container and system may also be used to transport, store or ship other types of substrates or be used in connection with other equipment within a semiconductor fabrication facility, and it should be apparent that many of the inventive concepts described above would be equally applicable to the use of other semiconductor manufacturing processes, e.g., large area substrates, such as, 450 millimeter substrates or other non-semiconductor manufacturing applications such as solar cell substrates including all of their manufacturing technologies, such as; single crystal silicon, polycrystalline silicon, thin film, and organic processes. The container described herein may also be utilized as a shipping container for shipping the substrates between different facilities, as well as transporting the substrates within a facility. In addition, the embodiments provided may include a container configured to support a single substrate or multiple substrates through the embodiments described herein.
Although the foregoing invention has been described in some detail for purposes of clarity of understanding, it will be apparent that certain changes and modifications can be practiced within the scope of the appended claims. Accordingly, the present embodiments are to be considered as illustrative and not restrictive, and the invention is not to be limited to the details given herein, but may be modified within the scope and equivalents of the appended claims. In the claims, elements and/or steps do not imply any particular order of operation, unless explicitly stated in the claims.
