HIGH-THROUGHPUT WORKPIECE HANDLING

Abstract

A system and method for receiving unprocessed workpieces, moving them, orienting them and placing them in a load lock, or other end point is disclosed. The system includes a gantry module for moving workpieces from a conveyor system to a swap module. The swap module is used to remove a carrier or matrix of processed workpieces from a load lock and place a carrier of matrix of unprocessed workpieces in its place. The processed workpieces are then moved by the gantry module back to the conveyor. The gantry module may have X, Y, Z and rotational actuators and include an end effector having multiple grippers. A method of aligning a plurality of workpieces on the end effector so that the plurality can be transported at the same time is also disclosed.

Description

This application claims priority of U.S. Provisional Patent Application Ser. No. 61/554,715, filed Nov. 2, 2011, the disclosure of which is incorporated herein in its entirety.

FIELD

This invention relates to workpiece handling and, more particularly, to workpiece handling for high-throughput applications.

BACKGROUND

Ion implantation is a standard technique for introducing conductivity-altering impurities into a workpiece. A desired impurity material is ionized in an ion source, the ions are accelerated to form an ion beam of prescribed energy, and the ion beam is directed at the surface of the workpiece. The energetic ions in the beam penetrate into the bulk of the workpiece material and are embedded into the crystalline lattice of the workpiece material to form a region of desired conductivity.

Ion implantation has been demonstrated as a viable method to dope solar cells. Two concerns of the solar cell manufacturing industry are manufacturing throughput and cell efficiency. Cell efficiency measures the amount of energy converted into electricity. Higher cell efficiencies may be needed to stay competitive in the solar cell manufacturing industry. However, manufacturing throughput cannot be sacrificed in order to increase cell efficiency.

Use of ion implantation removes process steps needed for existing solar cell technology, such as diffusion furnaces. For example, a laser edge isolation step may be removed if ion implantation is used instead of furnace diffusion because ion implantation will only dope the desired surface. Ion implantation also offers the ability to perform a blanket implant of an entire surface of a solar cell or a selective (or patterned) implant of only part of the solar cell. Selective implantation at high throughputs using ion implantation avoids the costly and time-consuming lithography or patterning steps used for furnace diffusion. Selective implantation also enables new solar cell designs. Furthermore, ion implantation has been used make solar cells with higher cell efficiencies.

Therefore, any improvement to manufacturing throughput of an ion implanter or its reliability would be beneficial to solar cell manufacturers worldwide. This may accelerate the adoption of solar cells as an alternative energy source.

SUMMARY

A system and method for receiving unprocessed workpieces, moving them, orienting them and placing them in a load lock, or other end point is disclosed. The system includes a gantry module for moving workpieces from a conveyor system to a swap module. The swap module is used to remove a carrier or matrix of processed workpieces from a load lock and place a carrier of matrix of unprocessed workpieces in its place. The processed workpieces are then moved by the gantry module back to the conveyor. The gantry module may have X, Y, Z and rotational actuators and include an end effector having multiple grippers. A method of aligning a plurality of workpieces on the end effector so that the plurality can be transported at the same time is also disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present disclosure, reference is made to the accompanying drawings, which are incorporated herein by reference and in which:

FIG. 1 is a perspective view of a first embodiment of a workpiece handling system;

FIG. 2 is a top perspective view of the first embodiment of a workpiece handling system illustrated in FIG. 1;

FIG. 3 is a side perspective view of the first embodiment of a workpiece handling system illustrated in FIG. 1;

FIGS. 4A-E illustrate one embodiment of workpiece handling using the workpiece handling system illustrated in FIGS. 1-3;

FIGS. 5A-F illustrate another embodiment of workpiece handling using the workpiece handling system illustrated in FIGS. 1-3;

FIG. 6 is an embodiment of a gantry module as illustrated in FIG. 1;

FIGS. 7A-E illustrate an embodiment of workpiece handling using the workpiece handling system illustrated in FIG. 6;

FIG. 8 is a flow chart showing a method of picking up workpieces using the gantry module of FIG. 6;

FIG. 9 is an embodiment of a swap module as illustrated in FIG. 1;

FIG. 10 is a second embodiment of an end effector for use with a swap module as illustrated in FIG. 1;

FIGS. 11A-C show the placement of workpieces in a load lock using the end effector of FIG. 10; and

FIG. 12 shows a configuration using two workpiece handling systems.

DETAILED DESCRIPTION

The workpiece handling system herein is described in connection with solar cell workpieces. However, the embodiments can be used with other workpieces such as semiconductor wafers, light emitting diodes (LEDs), silicon-on-insulator (SOI) wafers, or other devices. The workpiece handling system can be used with ion implanters or with other processing equipment like deposition, etching, or other workpiece processing systems. Thus, the invention is not limited to the specific embodiments described below.

The exemplary workpiece handling system 100 illustrated in FIGS. 1-3 may be capable of processing greater than approximately 2000 wafers per hour (wph) using a 4×4 matrix of workpieces. Of course, other workpiece matrix designs may be used and the embodiments herein are not limited merely to a 4×4 matrix. A 2×2 or 2×4 matrix also may be used. These figures represent the workpiece handling system, the individual components of which will be described in more detail below. FIG. 1 shows a perspective view of the belt modules, gantry module, matrix, build station, swapbot and load locks. FIGS. 2 and 3 show a top view and side view of these components, respectively.

This matrix 101 of workpieces may be placed in a carrier that has individual slots or depressions to hold workpieces. In an alternate embodiment, no carrier is used for the workpieces. The matrix 101 instead is handled by robots or other means before and during processing. The matrix in this instance may be held on an electrostatic or mechanical clamp, or by gravity.

This workpiece handling system 100 transfers workpieces from a cassette or other interface, builds the matrix 101, and moves the matrix 101 into the load lock 102. The reverse process also may be performed by the workpiece handling system 100 to transfer workpieces back to the cassette or other interface. The load lock 102 is connected to an ion implanter or some other processing tool.

In this embodiment, three belt modules 106a-c may transport the workpieces from the cassette. The transport of the workpieces may be performed at a specified speed, interval, or pitch. A robot may be used to place the workpieces onto the belt modules 106a-c. At the end of the belt modules 106a-c, a camera 107 and a controller will determine the position of each of the workpieces and will determine if the position or orientation of the workpieces needs to be corrected during the transfer to the matrix 101. More or less than three belt modules 106a-c may be used in other embodiments. Each of these belt modules 106a-c may be designated for load or unload of workpieces or may be used for both loading and unloading.

A gantry module 108 picks workpieces from the belt modules 106a-c and builds the matrix 101, such as using electrostatic, mechanical, or vacuum forces. The gantry module 108 may move in three-dimensions and may also achieve rotational motion. This gantry module 108 may use information from the camera 107 and controller to correct the position or orientation of the workpieces. The gantry module 108 also may remove workpieces from the matrix 101 to places onto the belt modules 106a-c for transfer back to the cassette or other interface.

The gantry module 108 may have at least one y-axis actuator, one x-axis actuator, one z-axis actuator, and a tilt, or rotational, actuator. This provides four degrees of freedom and enables pick-and-place operation. The gantry module 108 can correct the workpieces in the x, y, and θ (tilt) directions. The gantry module 108 also can transport the workpieces from any of the belt modules 106a-c to any of the positions in the matrix 101. Rotation or tilting in the 0 direction may be performed by the gantry module 108.

In an alternate embodiment, the gantry module 108 can skip or not place “bad” workpieces. These “bad” workpieces may be damaged or broken. The gantry module 108 also may compensate for “missing” workpieces that may not have properly loaded onto the belt modules 106a-c. The camera 107 and a processor may be used to assist the gantry module 108 in this regard.

The end effector 105 of the gantry module 108 is a multi-gripper design that may be a smaller version of the matrix 101. Thus, while the matrix 101 may be 4×4 workpieces, the gantry module 108 may be 1×4 or some other design. The workpieces may be corrected by the gantry module 108 either individually or as a 1×4 group.

In one embodiment of operation, the gantry module 108 will take four workpieces that have been processed and place these on one of the belt modules 106a-c. The gantry module then takes four unprocessed workpieces from the belt modules 106a-c and places these in the matrix 101. This reduces the amount of travel time and the time that the gantry module 108 is not transporting workpieces. The unprocessed workpieces are placed in the matrix 101 where the previously processed workpieces were removed from. This process may be repeated and the combined load and unload of the matrix 101 by the gantry module 108 may be used for the entire matrix 101. Of course, the gantry module 108 may fully unload the matrix 101 before placing unprocessed workpiece on the matrix 101.

A swap module 109 (using at least one “swap robot” or “swapbot”) may be used to place the matrix 101 into the load lock 102. This swap module 109 may be a linear actuator. There may be one or more than one swap robots in the swap module 109. These may, for example, hold an empty carrier and a full carrier. One swap robot may be parked out of the way during loading and unloading. Each swap robot may have a z-axis actuator and one or more y-axis actuators for each of the blades. The first swap robot may pick up unprocessed workpieces in the matrix 101 from the build station 110 and the second swap robot may extend into the load lock 102 to pick up processed workpieces. The processed workpieces are removed from the load lock 102 and the unprocessed workpieces are placed in the load lock 102. The processed workpieces are returned to the build station for unloading while the unprocessed workpieces are implanted or otherwise processed.

The building of the matrix 101 may be coordinated with the pumping down or venting of the load lock 102. This may increase throughput of the system attached to the load lock 102, such as an ion implanter.

FIG. 6 shows an expanded view of the gantry module 108. The gantry module 108 has two rails, or Y actuators 120a-b, on which a crossbar, or X actuator 121, moves. In some embodiments, a servo motor 122 is positioned on one of the Y actuators 120b with a gear box 123 and a drive shaft 124. The rotation of the servo motor 122 causes corresponding rotation in the drive shaft 124, which, in turn, causes X actuator 121 to move. The robot head 125 is located on the X actuator 121. Through movement of the Y actuators 120a-b and X actuator 121, the robot head 125 may move in the X and Y directions. The robot head 125 also has a Z actuator 126, which allows the robot head 125 to move up and down as necessary.

The robot head 125 also has an end effector 128. In some embodiments, the end effector 128 may include a plurality of grippers 129 at its distal end. The grippers 129 may use any suitable system for picking up and holding the workpieces, including but not limited to Venturi device-based suction systems and vacuum systems. In some embodiments, the suction to each gripper 129 is separately controlled such that one gripper may be picking up or holding a workpiece, while another gripper is inactive. These grippers 129 may be arranged in any configuration, such as a 1 x 4 linear array as shown in FIG. 6. In some embodiments, such as that shown in FIG. 6, the end effector 128 may have the ability to rotate about the Z axis, where this rotation is described as tilt or 0 axis rotation in this disclosure. This rotational actuator allows the end effector (and the plurality of grippers) to be rotated as described in more detail with respect to FIG. 7.

In another embodiment, rather than, or in addition to using a common rotational actuator to rotate the entire end effector 128, individual rotational actuators are located on the end effector 128, such that each gripper may be independently rotated.

The gantry module 108 also has a controller (not shown), which controls the movements of the various actuators and grippers. Of course, more than one controller can also be used if desired. The controller includes a processing unit, a storage element and an input/output module. The storage element contains instructions which allow the gantry module 108 to execute the sequences described herein, as well as any other desired movements.

Having described the structural components of the gantry module 108, its operation will be described. FIGS. 4A-E illustrate one embodiment of workpiece handling using the workpiece handling system illustrated in FIGS. 1-3. In FIG. 4A, the end effector 128, which may be part of the gantry module 108 of FIG. 6, is positioned over a first belt module 106c. This is done by moving the X actuator 121 and the Y actuators 120a-b, as described above.

At this time, the matrix 101 may contain sixteen processed workpieces 201 in a 4×4 arrangement. Other arrangements may also within the scope of the disclosure. One belt module, in this instance belt module 106a, contains unprocessed workpieces 202 (shaded in the embodiment of FIG. 4A).

In FIG. 4B, the gantry robot head, and specifically, the end effector 128, is moved from its previous position and is positioned over the matrix 101. The end effector 128 then picks up four processed workpieces 201 from a row of the matrix 101. The gantry module 108 may correct the position or tilt of the processed workpieces 201 after these have been gripped or picked up. In other embodiments, the gantry module 108 corrects the position or tilt of the workpieces before they are picked up. For example, in one embodiment, the gantry module 108 uses camera 107 to determine the tilt of a first processed workpiece 201a. It may, for instance, determine that the workpiece 201a is rotated 2° clockwise. The gantry module 108 will, in response to this, actuate the rotational actuator in the robot head 125 to rotate the end effector 128 by 2°. The end effector 128 will then pick up the processed workpiece 201a. The gantry module 108 will then utilize the camera 107 (as seen in FIG. 1) to determine the position and tilt of the second processed workpiece 201b. The gantry module 108 will then rotate the end effector, which is holding processed workpiece 201a, to align with processed workpiece 201b. Once aligned, the end effector will pick up the second processed workpiece 201b. The gantry module 108 may repeat this sequence until all process workpieces are picked up by the end effector 128.

In FIG. 4C, the gantry robot 200 has transported the four processed workpieces 201 to one of the belt modules, in this case belt module 106c for unloading. In the case where the processed workpieces were aligned as they were picked up, the end effector simply places the processed workpieces 201 on the belt module 106c. In another embodiment, the gantry module 107 does not align the processed workpieces 201 as they are picked up, and performs the alignment procedure described above as the processed workpieces 201 are placed. In yet other embodiments, the alignment procedure is not performed on processed workpieces 201, as it is assumed that these were previously aligned by the gantry module 108 when they were original placed in the carrier.

In FIG. 4D, the gantry module 108, after placing processed workpieces 201, positions the end effector 128 over the unprocessed workpieces 202 and picks these up. The unprocessed workpieces 202 may be crooked or positioned incorrectly due to errors in unloading from the cassette or other interface. In some embodiments, the gantry module 108 may correct the position or tilt of the unprocessed workpieces 202 after these have been gripped or picked up. In other embodiments, the gantry module 108 aligns the unprocessed workpieces 202 individually as they are being picked up as described above. FIG. 8 shows a flowchart of the procedure used to align workpieces as they are being picked up. Of course, this procedure is applicable to an end effector having an arbitrary number of grippers. The alignment can also be performed when the workpieces are being placed instead.

In FIG. 4E, the gantry module 107 moves the robot head and places the four unprocessed workpieces 202 into the matrix 101. The unloaded processed workpieces 201 may have been removed to the cassette or other interface using one of the belt modules 106a-c. More unprocessed workpieces 202 may be loaded onto one of the belt modules 106a-c. This transfer process is repeated until the processed workpieces 201 are unloaded from the matrix 101 and the unprocessed workpieces 202 have been loaded into the matrix 101.

The above description illustrates one benefit of the rotational actuator that allows rotary movement of the end effector, namely, the ability to align workpieces as they are being picked up or placed. FIG. 7A-E shows another benefit of the rotational actuator in the robot head 125. In this embodiment, the end effector 128, which may be part of the gantry module 108 of FIG. 6, transfers four processed workpieces 201 from the matrix 101 and places these four processed workpieces 201 on one of the belt modules 106a-c. However, the end effector 128 rotates 90° between the picking up of the processed workpieces 201 from the matrix 101 and the placing of those processed workpieces 201 on the belt module 106a-c, as shown in FIGS. 7B-7C. Similarly, the end effector 128 rotates 90° (or −90°) when transferring unprocessed workpieces 202 from the belt modules 106a-c to the matrix 101, as shown in FIGS. 7D-7E. As before, alignment can be done as the workpieces are being picked up or placed, and this alignment may be performed at the belt module 106a-c, at the matrix 101, or at both locations.

FIG. 12 shows a configuration using two workpiece handling systems 500a, 500b. In this system, the two systems 500a, 500b each move workpieces to and from a respective load lock 510a, 510b. Workpieces are then moved from the load locks 510a, 510b to a transfer chamber 520. Workpieces are transferred from the transfer chamber 520 to the process chamber 530.

The transfer chamber moves workpieces from one port to another by rotating the arm of a robot. Thus, workpieces that enter from load lock 510b are rotated 180° before entering the process chamber 530. However, note that the load lock 510a is oriented at 90° with respect to load lock 510b. Thus, the robot only rotates workpieces from load lock 510a 90° before they enter the process chamber 530. Typically, the robot within the transfer chamber 520 is simple, comprising an arm that rotates about a pivot point and which can be extended radially outward into the load locks 510a, 510b to pick up and deliver workpieces. The arm is then be rotated about this pivot point, allowing it to deliver workpieces to and from the process chamber 530. Rotation of workpieces separate from that which occur as a result of rotation about the pivot point is not typically possible. However, the process chamber 530 expects that all workpieces are received in a single orientation.

Thus, if the orientation of workpieces from workpiece handling system 500a is to match the orientation of those from workpiece handling system 500b, these workpieces must be rotated by 90° relative to those arriving from workpiece handling system 500b. In other words, assume that the robot in the transfer station 520 rotates clockwise. To insure a consistent orientation, workpieces from system 500a may be rotated clockwise 90° prior to entering the load lock 510a. Alternatively, workpieces from system 500b may be rotated 90° counterclockwise before they enter load lock 510b. The rotational actuator of the gantry module 107 allows either of these actions.

In another embodiment, rotational actuators are located on the end effector, such that each gripper has an associated rotational actuator. This configuration may allow the alignment sequence shown in FIG. 8 to be performed in parallel, such that all workpieces can be aligned by a corresponding gripper simultaneously, if the cells are pre-aligned with funnels, bumpers and/or stops.

FIG. 9 shows an expanded view of the swap module 109. The swap module 109 has two swap robots 300, 301. These swap robots 300, 301 maintain a fixed spatial relationship with each other in the X and Z directions. In other words, the swap robots 300, 301 have only one degree of freedom between them, i.e. the Y direction. To accomplish this, the swap module 109 has two Y actuators 310, 311, which are offset from each other in the Z direction. These Y actuators 310, 311 have the capability to move back and forth in the Y direction, irrespective of each other. In other words, Y actuator 310 may be in the front position, while the other Y actuator 311 is in the rear position (as shown in FIG. 9). Of course, both can be in the front position or both may be in the rear position. In these configurations, the swap robot 300 would be directly on top of the swap robot 301.

Each swap robot 300, 301 may have an end effector, which is linked to a carrier or can hold a matrix 101 of workpieces. The swap module 109 also has a Z actuator 320, which moves both Y actuators up and down in unison. The swap module 109 may also have a leveling device 330. The leveling device 330 is used to insure that the end effectors are kept horizontal.

The swap module 109 also has a controller (not shown), which controls the movements of the various actuators and end effectors. Of course, more than one controller can also be used if desired. The controller includes a processing unit, a storage element and an input/output module. The storage element contains instructions which allow the swap module 109 to execute the sequences described herein, as well as any other desired movements.

FIGS. 5A-F illustrate one embodiment of how the swap module 109 cooperates with the load lock 102 and gantry module 108 to move workpieces. The first swap robot 300 and second swap robot 301 may be part of the swap module 109 of FIGS. 1-3. It should be noted that, in one embodiment, the gantry module 108, and specifically the end effector 128, moves workpieces to and from the swap module 109 directly. In other words, the gantry module 108 and the swap module 109 cooperate together to move the unprocessed workpieces from the belt modules 106 to the load lock 102. The workpieces are transferred by the gantry module 108 from the belt modules 106 to the swap robot 300 or swap robot 301 without an intervening step, such as putting the workpieces on a static surface. The swap robots 300, 301 then move the workpieces to the load lock 102.

In FIG. 5A, the gantry robot 108, and specifically end effector 128 has loaded unprocessed workpieces 202 on the first swap robot 300 from the belt module 106. These unprocessed workpiece 202 may be in a 4×4 matrix, though only four are illustrated in the cross-section of FIG. 5A. The first swap robot 300 and second swap robot 301 are lifted in FIG. 5B using the Z actuator 320 (see FIG. 9). At this point, the second swap robot 301, which is empty, extends into the load lock 102. The second swap robot 301 removes processed workpieces 201 in FIG. 5C, which also may be in a 4×4 matrix. This action is performed using the Y actuator 310 (see FIG. 9). The first swap robot 300 then places the unprocessed workpieces 202 into the load lock 102. So that both swap robots 300, 301 are able to access the load lock 102, the first swap robot 300 and second swap robot 301 may change vertical position during the loading and unloading of the load lock 102 if it only has a single port. This change in vertical position is achieved through use of the Z actuator 320. If the load lock 102 has multiple ports, then no vertical position change during loading and unloading may be required.

In FIG. 5D, the first swap robot 300 is parked out of the way. This parked position may be above the load lock 102, below the load lock 102, or in the case of two load locks 102, between the load locks 102. This enables the gantry robot 108, and specifically end effector 128, to unload the processed workpieces 201 from the second swap robot 300. The gantry robot 108 also may load unprocessed workpieces on the second swap robot 301. The first swap robot 300 will then be removed from the parked position, unload processed workpieces 201 from the load lock 102 as seen in FIG. 5E, and then the second swap robot 301 will place unprocessed workpieces 202 into the load lock 102 as seen in FIG. 5F. The gantry robot 200, and specifically end effector 128, will unload the processed workpieces 201 from the first swap robot 300 and load unprocessed workpieces 202 onto this first swap robot 300. Then the process then may begin again as illustrated in FIG. 5A. The second swap robot 301 may be placed in a parked position or may just remain disposed under the first swap robot 300 during loading and unloading of the first swap robot 300.

There are several ways that the swap robots 300, 301 may join with the carrier or matrix 101. In FIG. 9, the swap robots 300, 301 have end effectors 340, 341, respectively. These end effectors 340, 341 have one or more holes 350 passing through at least a portion of their bodies. These holes 350 are used to hold fingers 371, which extend from the end effector 340, 341. In one embodiment, there are three fingers 371a-c, with two fingers 371a,c positioned so as to be slightly wider than the carrier 101, and a third shorter finger 371b located between these two outer fingers. The carrier or matrix 101 has a main portion 370, which is used to hold the workpieces. Fingers 371a,c extend along the outer edges of main portion 370. In some embodiments, the fingers 371a,c have a pin or other projection along their inner edge that is used to contact the outer edge of main portion 370. In addition, shorter finger 371b may have a projection which is used to contact a third side of the main portion 370 of the carrier 101. To place the workpieces within the load lock 102, the end effector 340 with the carrier 101 is extended into the port. The end effector 340 is lowered such that the carrier or matrix 101 touches the lower surface within the load lock 102. As the end effector 340 is lowered slightly further, the projections no longer contact the main portion 370.

At this point, the end effector 340 can be moved horizontally away from the load lock 102, and the carrier or matrix 101 will remain in the load lock 102. To join the end effector 340 with the carrier or matrix 101, the reverse operation is performed. The end effector 340 is extended into the load lock 102 below the level of the carrier main portion 370. The end effector 340 is extended until the projection on finger 371b is in contact, or nearly in contact, with the front edge of the carrier 370. The end effector 340 is then lifted. The projections along the inner edges of the fingers 371a,c contact the outer sides of the main portion 370, while the projection on the shorter finger 371b contacts the front side of the carrier 370. The end effector 340 is then further lifted, while elevates the carrier away from the load lock 102. The end effector 340 can then be moved horizontally away from the load lock 102.

FIG. 10 shows another embodiment of an end effector 400. This end effector 400 comprises a plurality of fingers 410 that are spaced apart. Unlike the fingers 371 of the previous embodiments, these fingers 410 are used to hold workpieces thereon. Optionally located on each finger 410 are one or more workpiece holders 420. In one embodiment, each workpiece holder 420 has a raised center portion 425, which is perpendicular to the dimension of the fingers 410, and two lower end portions 427, 428, one on each side of the raised center portion 425. The gantry module 108, and specifically the end effector 128, places the workpiece such that its ends rest against the raised center portion 425 of two adjacent workpiece holders 420. The workpiece holder 420 is used to hold the one side of a first workpiece on one lower end portion 427, and the opposite side of the adjacent workpiece with the opposite lower end portion 428, such that the two adjacent workpieces are separated by the raised center portion 425. The raised center portion 425 is used to separate the workpieces from each other and also serves to create a natural contour on which each workpiece rests so as to keep the workpieces stable. The raised center portions 425 also can be used to align the workpieces when the end effector 400 is accelerated during wafer transfer and the workpieces are pressed against the raised center portions 425.

FIGS. 11A-C show a top view of a load lock 102 used with the end effector 400 of FIG. 10. The load lock 102 has a plurality of standoffs 450 on which the workpieces 201 will rest. FIG. 11A shows an empty load lock 102 with the standoffs 450. In FIG. 11B, the end effector 400 with each of the fingers 410 having three workpieces 201 is moved into the load lock. The end effector 400 is then lowered such that each workpiece 201 rests on several of the standoffs 450. The end effector 400 is then removed, as shown in FIG. 11C, and the workpieces 201 remain on the standoffs 450.

In some embodiments, the standoffs 450 in the load lock 102 are spaced so as to correspond to the four corners of each workpiece (in the case of rectangular workpieces), as shown in FIG. 11. In other embodiments, the load lock 102 is designed such that lower surface has a plurality of slots. The fingers 410 pass through these slots in the lower surface of the load lock 102, and allow the workpieces to rest on that lower surface.

In another embodiment, the lower surface of the load lock may have movable pins. Thus, rather than having the end effector 400 move in the vertical direction as described above, the end effector 400 only moves in the horizontal direction. In this embodiment, the end effector 400 enters the load lock 102 moving only in a horizontal direction. The pins within the lower surface of the load lock 102 are then upwardly actuated. These pins move upward to contact the workpieces, thereby removing them from the fingers 410. The end effector 400 can then be withdrawn from the load lock by simply moving the end effector 400 in the horizontal direction. The pins in the lock load 102 can then be lowered if desired. To remove the workpieces, the pins in the load lock 102 are fully extended. This lifts the workpieces from the lower surface of the load lock 102. The fingers 410 then enter the load lock 102 at a level below the workpieces. The pins in the load lock 102 then retract, causing the workpieces to move downward until they rest on the fingers 410.

The present disclosure is not to be limited in scope by the specific embodiments described herein. Indeed, other various embodiments of and modifications to the present disclosure, in addition to those described herein, will be apparent to those of ordinary skill in the art from the foregoing description and accompanying drawings. These other embodiments and modifications are intended to fall within the scope of the present disclosure. Furthermore, although the present disclosure has been described herein in the context of a particular implementation in a particular environment for a particular purpose, those of ordinary skill in the art will recognize that its usefulness is not limited thereto and that the present disclosure may be beneficially implemented in any number of environments for any number of purposes. Accordingly, the claims set forth below should be construed in view of the full breadth and spirit of the present disclosure as described herein.

Claims

1. A workpiece handling system, comprising a gantry module for moving a plurality of workpieces from a first location to a second location, said gantry module comprising:

an end effector having one or more grippers for picking up said workpieces;

a first actuator to move said end effector in an X direction;

a second actuator to move said end effector in a Y direction;

a third actuator to move said end effector in a Z direction; and

a rotational actuator to rotate said end effector about said Z direction.

2. The workpiece handling system of claim 1, wherein said grippers are in communication with a suction system.

3. The workpiece handling system of claim 1, further comprising a swap module, said swap module comprising:

two swap module end effectors, each having an associated actuator to move said swap module end effector in said Y direction; and an actuator to move said two swap module end effectors in said Z direction, wherein a distance between said two swap module end effectors in said Z direction remains constant.

4. The workpiece handling system of claim 3, wherein said swap modules end effectors are adapted to couple with a carrier, said carrier adapted to store a plurality of workpieces.

5. The workpiece handling system of claim 4, wherein said second location comprises said carrier.

6. The workpiece handling system of claim 3, wherein said swap module end effectors comprise a plurality of fingers, each of said fingers adapted to support one or more workpieces.

7. The workpiece handling system of claim 6, wherein said second location comprises said fingers.

8. The workpiece handling system of claim 1, wherein said end effector comprises a plurality of linearly arranged grippers.

9. A method of handling a plurality of workpieces from a source to a destination, comprising:

using a gantry module to pick up a plurality of workpieces from a first location and move said plurality of workpieces to a first swap module end effector, said gantry module having an end effector capable of moving in x, y, and z directions and capable of rotating about said z direction; and

using said swap module comprising: two swap module end effectors, wherein said swap modules move in said y and z directions to load and unload said plurality of workpieces from said destination.

10. The method of claim 9, wherein second swap module end effector removes a second plurality of workpieces from said destination prior to said first swap module end effector placing said plurality of workpieces at said destination.

11. The method of claim 10, wherein said end effector picks up said second plurality of workpieces from said second swap module end effector and delivers them to a third location.

12. The method of claim 11, wherein said first swap module is located above said second swap module, and said first swap module is moved in said y direction to a parked location to allow workpieces from said second swap module to be accessed by said end effector.

13. The method of claim 12, wherein said destination comprises at least one load lock and said parked location is selected from a position above said load lock, a position below said load lock, and a position between said load lock and a second load lock.

14. The method of claim 9, wherein said end effector comprises a plurality of linearly arranged grippers and picks up a plurality of workpieces arranged along a first direction, and places said plurality of workpieces on said first swap module end effector along a second direction, said second direction orthogonal to said first direction.

15. The method of claim 9, whereby a carrier is coupled to said first swap module end effector and said end effector places said workpieces in said carrier.

16. The method of claim 15, wherein said swap module end effector places said carrier at said destination.

17. The method of claim 9, whereby said swap module end effector comprises a plurality of fingers, and said end effector places said workpieces on said fingers.

18. The method of claim 17, further comprising aligning each of said workpieces against a raised center portion on each of said plurality of fingers when said swap module end effector is moved in said y direction.

19. The method of claim 9, wherein said end effector comprises a plurality of grippers and said gantry module moves said end effector in said x, y, z directions and rotates about said z direction to successively align each of said workpieces with a respective one of said plurality of grippers prior to picking up each of said workpieces.

20. The method of claim 19, further comprising using a suction system to pick up one of said plurality of workpieces after said end effector is aligned to a respective one of said plurality of grippers.

21. A method of picking up a plurality of workpieces using a gantry module, said gantry module having an end effector having a plurality of linearly arranged grippers for picking up said workpieces, said method comprising:

using a camera to determine a location of said plurality of workpieces;

aligning a first gripper of said end effector to a first of said plurality of workpieces;

using a suction system, in communication with said first gripper to pick up said first of said plurality of workpieces;

aligning a second gripper of said end effector to a second of said plurality of workpieces; and

using a suction system, in communication with said second gripper to pick up said second of said plurality of workpieces while said first gripper holds said first of said plurality of workpieces.

22. The method of picking up a plurality of workpieces of claim 21, further comprising transferring said first and second of said plurality of workpieces to a swap module, wherein said swap module moves said first and second of said plurality of workpieces to a destination.