Wiring-free, plumbing-free, cooled, vacuum chuck

• US 7,954,449 B2
• Filed: 05/08/2007
• Issued: 06/07/2011
• Est. Priority Date: 05/08/2007
• Status: Active Grant

• Current Assignee: Meyer Burger (Germany) GmbH (Meyer Burger Technology AG)
• Original Assignee: Palo Alto Research Center, Inc. (Xerox Holdings Corp.)
• Inventors: Duff, David G., Eldershaw, Craig
• Primary Examiner(s): Hassanzadeh; Parviz
• Assistant Examiner(s): CAPOZZI, CHARLES
• Application Number:
  US11/746,012
• Publication Number:
  US 20080277885A1
• Time in Patent Office: 1,491 Days
• Field of Search: 118/322, 118/314
• US Class Current: 118/314
• CPC Class Codes: B25B 11/005 Vacuum work holders
• CPC Class Codes: H01L 21/67109 mainly by convection
• CPC Class Codes: H01L 21/67173 in-line arrangement
• CPC Class Codes: H01L 21/67748 horizontal transfer of a single workpiece
• CPC Class Codes: H01L 21/6838 with gripping and holding devices using a vacuum; Bernoulli devices
• CPC Class Codes: H01L 31/1876 Particular processes or apparatus for batch treatment of the devices
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10T 279/11 Vacuum

Abstract

A solar cell production system utilizes self-contained vacuum chucks that hold and cool solar cell wafers during transport on a conveyor between processing stations during a fabrication process. Each self-contained vacuum chuck includes its own local vacuum pump and a closed-loop cooling system. After each wafer is processed, it is removed from its vacuum chuck, and the vacuum chuck is returned to the start of the production line by a second conveyor belt. In one embodiment, each vacuum chuck includes an inductive power supply that is inductively coupled to an external source to drive that vacuum chuck'"'"'s vacuum pump and cooling system. An optional battery is recharged by the inductive power supply, and is used to power the vacuum pump and cooling system during hand-off between adjacent processing stations.

Claims

1. A production system comprising:

a plurality of self-contained portable vacuum chucks, wherein each of the self-contained portable vacuum chucks includes a chuck body, a support structure disposed on the chuck body, the support structure including an upper wall having a support surface and defining a vacuum chamber that is disposed below the support surface, a vacuum pump mounted on the chuck body for generating a low pressure in the vacuum chamber, a thermal control system including ducts disposed on the upper wall of the support structure below the support surface, and a power supply mounted on the chuck body and coupled to the vacuum pump and the thermal control system, whereby the vacuum pump functions to generate said low pressure in the vacuum chamber and the thermal control system functions to regulate environmental aspects of the support surface in response to energy drawn from the power supply;

means for loading a plurality of wafers onto said plurality of self-contained vacuum chucks such that one of said plurality of wafers is disposed on the support surface of each of said plurality of self-contained portable vacuum chucks

a plurality of processing stations; and

means for sequentially conveying the plurality of self-contained portable vacuum chucks between the plurality of processing stations.

2. The production system of claim 1, further comprising means for off-loading the wafers from the plurality of self-contained portable vacuum chucks,

wherein said means for sequentially conveying comprises:

a first conveyor belt disposed between said means for loading and said means for off loading the wafers from the self-contained portable vacuum chucks, and

a second conveyor belt disposed between said means for off-loading the wafers and said means for loading said wafers.

3. The production system of claim 2,

wherein said plurality of processing stations comprises:

an extrusion apparatus including a sacrificial material source, a gridline material source, and a co-extrusion head including a plurality of three-channeled cavities, each said three-channeled cavity including a central channel communicating with said gridline material source and two side channels communicating with said sacrificial material source, said central channel and said two side channels of said plurality of three-channeled cavities being arranged such that, when gridline material is introduced into said co-extrusion head from said gridline material source and sacrificial material is introduced into said co-extrusion head from said sacrificial material source, said gridline material and said sacrificial material are co-extruded onto a target wafer of said plurality of wafers disposed under said extrusion head in a manner that creates parallel, elongated extruded structures on said target wafer, wherein the gridline material of each extruded structure includes a high-aspect ratio gridline structure, and the sacrificial material of said each structure forms associated first and second sacrificial material portions respectively disposed on opposing sides of the associated high-aspect ratio gridline, and

means for removing the first and second sacrificial material portions.

4. The production system of claim 1,

wherein each of the plurality of processing stations includes an associated power source, and

wherein the power supply of each said self-contained portable vacuum chuck comprises inductive means for coupling to the power source when said each self-contained portable vacuum chuck is disposed adjacent to said each associated processing station such that power is transferred from said inductive means to said vacuum pump and said thermal control system.

5. The production system of claim 4, wherein the power supply of each said self-contained portable vacuum chuck further comprises means for supplying power to said self-contained portable vacuum pump and said thermal control system when said each vacuum chuck is disposed between said plurality of processing stations.

6. The production system of claim 1, wherein the ducts of each said self-contained portable vacuum chuck are disposed in the vacuum chamber, and wherein the thermal control system of said each self-contained portable vacuum chuck comprises a heat exchanger and a pump for circulating a coolant in the ducts.

7. The production system of claim 1, wherein the ducts are disposed in the vacuum chamber, and wherein the thermal control system comprises means for circulating a fluid in the ducts.

8. The production system of claim 1,

wherein each of the plurality of processing stations includes an associated power source and a plurality of associated connectors coupled to the associated power source, and

wherein the power supply of each said self-contained portable vacuum chuck comprises a battery for supplying power to said vacuum pump and said thermal control system of said each self-contained portable vacuum chuck, and contact pads disposed on an external surface of said each self-contained portable vacuum chuck and coupled to said battery, said contact pads being arranged such that, when said each self-contained portable vacuum chuck is disposed adjacent to one of said each associated processing station, the contact pads contact said plurality of associated connectors of said processing station such that power is transferred from said associated power source to said battery.

9. The production system of claim 1,

wherein each of the plurality of processing stations includes an associated mechanical power source and an associated mechanical connector coupled to the associated mechanical power source, and

wherein the power supply of each said self-contained portable vacuum chuck comprises means for driving said vacuum pump and said thermal control system using power supplied from said mechanical power source by way of said associated mechanical connector when said each self-contained portable vacuum chuck is disposed adjacent to one of said each associated processing station.

10. The production system of claim 1,

wherein each of the plurality of processing stations includes an associated electrical power source and an associated connector coupled to the associated electrical power source, and

wherein the power supply of each vacuum chuck comprises a generator disposed on said each self-contained portable vacuum chuck and arranged such that, when said each vacuum chuck is disposed adjacent to one of said each associated processing station, the generator contacts said associated connector of said processing station and is driven by said electrical power source such that power is transferred from said generator to said vacuum pump and said thermal control system.