WO2010051311A1 - Improved drum design for web processing - Google Patents

Improved drum design for web processing Download PDF

Info

Publication number
WO2010051311A1
WO2010051311A1 PCT/US2009/062370 US2009062370W WO2010051311A1 WO 2010051311 A1 WO2010051311 A1 WO 2010051311A1 US 2009062370 W US2009062370 W US 2009062370W WO 2010051311 A1 WO2010051311 A1 WO 2010051311A1
Authority
WO
WIPO (PCT)
Prior art keywords
workpiece
drum
continuous flexible
flexible workpiece
peripheral surface
Prior art date
Application number
PCT/US2009/062370
Other languages
French (fr)
Inventor
Mustafa Pinarbasi
Homayoun Talieh
Bulent M. Basol
Original Assignee
Solopower, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Solopower, Inc. filed Critical Solopower, Inc.
Priority to EP09824095A priority Critical patent/EP2355920A4/en
Publication of WO2010051311A1 publication Critical patent/WO2010051311A1/en

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/22—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the process of coating
    • C23C14/56—Apparatus specially adapted for continuous coating; Arrangements for maintaining the vacuum, e.g. vacuum locks
    • C23C14/562—Apparatus specially adapted for continuous coating; Arrangements for maintaining the vacuum, e.g. vacuum locks for coating elongated substrates
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
    • G06F3/14—Digital output to display device ; Cooperation and interconnection of the display device with other functional units
    • G06F3/1423—Digital output to display device ; Cooperation and interconnection of the display device with other functional units controlling a plurality of local displays, e.g. CRT and flat panel display
    • G06F3/1446—Digital output to display device ; Cooperation and interconnection of the display device with other functional units controlling a plurality of local displays, e.g. CRT and flat panel display display composed of modules, e.g. video walls
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
    • G06F3/14—Digital output to display device ; Cooperation and interconnection of the display device with other functional units
    • G06F3/1423—Digital output to display device ; Cooperation and interconnection of the display device with other functional units controlling a plurality of local displays, e.g. CRT and flat panel display
    • G06F3/1438—Digital output to display device ; Cooperation and interconnection of the display device with other functional units controlling a plurality of local displays, e.g. CRT and flat panel display using more than one graphics controller
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
    • G09F9/00—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements
    • G09F9/30—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the desired character or characters are formed by combining individual elements
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
    • G09F9/00—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements
    • G09F9/30—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the desired character or characters are formed by combining individual elements
    • G09F9/301—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the desired character or characters are formed by combining individual elements flexible foldable or roll-able electronic displays, e.g. thin LCD, OLED
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
    • G09F9/00—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements
    • G09F9/30—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the desired character or characters are formed by combining individual elements
    • G09F9/33—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the desired character or characters are formed by combining individual elements being semiconductor devices, e.g. diodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/0248—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies
    • H01L31/036—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies characterised by their crystalline structure or particular orientation of the crystalline planes
    • H01L31/0392—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies characterised by their crystalline structure or particular orientation of the crystalline planes including thin films deposited on metallic or insulating substrates ; characterised by specific substrate materials or substrate features or by the presence of intermediate layers, e.g. barrier layers, on the substrate
    • H01L31/03923—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies characterised by their crystalline structure or particular orientation of the crystalline planes including thin films deposited on metallic or insulating substrates ; characterised by specific substrate materials or substrate features or by the presence of intermediate layers, e.g. barrier layers, on the substrate including AIBIIICVI compound materials, e.g. CIS, CIGS
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/18—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof
    • H01L31/20—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof such devices or parts thereof comprising amorphous semiconductor materials
    • H01L31/206—Particular processes or apparatus for continuous treatment of the devices, e.g. roll-to roll processes, multi-chamber deposition
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D2252/00—Sheets
    • B05D2252/02—Sheets of indefinite length
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D3/00—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials
    • B05D3/04—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials by exposure to gases
    • B05D3/0493—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials by exposure to gases using vacuum
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2300/00—Aspects of the constitution of display devices
    • G09G2300/02—Composition of display devices
    • G09G2300/026—Video wall, i.e. juxtaposition of a plurality of screens to create a display screen of bigger dimensions
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2300/00—Aspects of the constitution of display devices
    • G09G2300/04—Structural and physical details of display devices
    • G09G2300/0439—Pixel structures
    • G09G2300/0452—Details of colour pixel setup, e.g. pixel composed of a red, a blue and two green components
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00—Control of display operating conditions
    • G09G2320/06—Adjustment of display parameters
    • G09G2320/0626—Adjustment of display parameters for control of overall brightness
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2380/00—Specific applications
    • G09G2380/06—Remotely controlled electronic signs other than labels
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/2085—Special arrangements for addressing the individual elements of the matrix, other than by driving respective rows and columns in combination
    • G09G3/2088—Special arrangements for addressing the individual elements of the matrix, other than by driving respective rows and columns in combination with use of a plurality of processors, each processor controlling a number of individual elements of the matrix
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/22—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources
    • G09G3/30—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels
    • G09G3/32—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED]
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy
    • Y02E10/541—CuInSe2 material PV cells
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • This invention relates to deposition methods and, more particularly, to methods for physical vapor deposition of metallic thin films on a conductive surface for manufacturing solar cells.
  • Solar cells are photovoltaic devices that convert sunlight directly into electrical power.
  • the most common solar cell material is silicon, which is in the form of single or polycrystalline wafers.
  • silicon-based solar cells the cost of electricity generated using silicon-based solar cells is higher than the cost of electricity generated by the more traditional methods. Therefore, since early 1970' s there has been an effort to reduce cost of solar cells for terrestrial use.
  • One way of reducing the cost of solar cells is to develop low-cost thin film growth techniques that can deposit solar-cell- quality absorber materials on large area substrates and to fabricate these devices using high- throughput, low-cost methods.
  • Group IBIIIAVIA compound semiconductors comprising some of the Group IB (Cu, Ag, Au), Group IIIA (B, Al, Ga, In, Tl) and Group VIA (O, S, Se, Te, Po) materials or elements of the periodic table are excellent absorber materials for thin film solar cell structures.
  • compounds of Cu, In, Ga, Se and S which are generally referred to as CIGS(S), or Cu(In,Ga)(S,Se) 2 or CuIn ⁇ x Ga x (S y Sei_ y ) k , where O ⁇ x ⁇ l, 0 ⁇ y ⁇ l and k is approximately 2, have already been employed in solar cell structures that yielded conversion efficiencies approaching 20%.
  • FIG. 1 The structure of a conventional Group IBIIIAVIA compound photovoltaic cell such as a Cu(In,Ga,Al)(S, Se 5 Te) 2 thin film solar cell is shown in Figure 1.
  • the device 10 is fabricated on a substrate 11, such as a sheet of glass, a sheet of metal, an insulating foil or web, or a conductive foil or web.
  • the absorber film 12 which includes a material in the family of Cu(In,Ga,Al)(S,Se,Te)2, is grown over a conductive layer 13 or contact layer, which is previously deposited on the substrate 11 and which acts as the electrical contact to the device.
  • the absorber film 12 is formed by depositing a precursor layer including Group IB and Group IIIA elements on the contact layer and then reacting this precursor stack film with one of Se and S to form the absorber layer.
  • the substrate 11 and the conductive layer 13 form a base 20 on which the absorber film 12 is formed.
  • Various conductive layers comprising Mo, Ta, W, Ti, and their nitrides have been used in the solar cell structure of Figure 1. If the substrate itself is a properly selected conductive material, it is possible not to use a contact layer 13, since the substrate 11 may then be used as the ohmic contact to the device.
  • a transparent layer 14 such as a CdS, ZnO or CdS/ZnO stack is formed on the absorber film. Radiation 15 enters the device through the transparent layer 14.
  • Metallic grids may also be deposited over the transparent layer 14 to reduce the effective series resistance of the device.
  • Sputtering and evaporation techniques which are also known as physical vapor deposition (PVD) techniques, are the preferred methods to deposit contact layers and transparent layers, although they may be used to deposit the components of the precursor films also.
  • PVD physical vapor deposition
  • Such layers can be deposited on a continuous flexible substrate using a well known roll to roll process tool in which the flexible substrate is fed from a supply roll into a process chamber and after receiving deposition the flexible substrate is taken up from the process chamber and wrapped around a receiving roll.
  • the process chamber can have for example one or more sputter deposition units or cathodes to deposit a desired material onto the continuous flexible substrate from the targets mounted on the cathodes.
  • the process chambers are equipped with a support apparatus to support the continuous flexible substrate during the deposition.
  • Figure 2 shows in perspective view of an exemplary cylindrical support apparatus 50 or drum, supporting a continuous flexible workpiece 52 or web. Drums with various sizes are used to control the tension of the web and to transfer the heat out of the web.
  • the drums can be using oil, water, or gas based cooling mechanisms to transfer heat from the web that gets heated by the sputtering cathodes.
  • Top surface 54 of the web 52 is exposed to the depositing material (depicted as arrows "M") originating from the target materials mounted on the cathodes.
  • M depositing material
  • the web 52 is advanced while in contact with the curved surface 56 of the drum 50 which can rotate as the workpiece moves.
  • the quality of the deposited film depends upon the physical contact between the web and the drum surface.
  • the curved surface 56 is a perfectly cylindrical surface.
  • the present invention provides a method an apparatus for the confinement of the web in a specific section of a drum, a better web contact with cooled surfaces, and depositing on the full width of the web on the drum.
  • the drum has a groove that guides the web. This allows the web to be confined to specific section of the drum that is kept free of deposits. With this approach, full width of the web can be deposited. Since the web is confined to groove, deposition on the drum takes place on the sides of the web. Since these areas are not travelled by the web, deposits can be removed with known methods without impacting the interaction between the web and the drum.
  • a buffer material in the form of a buffer belt or a buffer layer is placed between the drum and the web.
  • the buffer material can be highly conductive yet flexible material.
  • the width of the buffer material can be wide enough to capture all deposition flux. Once significant deposition is made either the buffer material can be cleaned or replaced with a new one.
  • Figure 1 is a schematic view of a prior art solar cell structure
  • Figure 2 is a perspective view of a prior art
  • Figures 3A is a schematic view of a roll to roll deposition system of the present invention having a drum to support a continuous substrate, wherein the drum surface includes a groove to guide the continuous substrate;
  • Figure 3B is schematic side view of an embodiment of the drum shown in Figure 3A;
  • Figures 4 A is a schematic view of another embodiment of a roll to roll deposition system of the present invention having a drum to support a continuous substrate, wherein the drum includes a smooth surface, and wherein a buffer belt has been disposed between the drum surface and the continuous substrate;
  • Figure 4B is schematic side view of the drum shown in Figure 4A;
  • Figure 4C is a schematic side view of the drum shown in Figure 3B, wherein a buffer belt has been disposed between the drum surface and the continuous substrate;
  • Figures 5A is schematic view of the roll to roll system shown in Figure 4A, wherein the buffer belt has been replaced with a buffer layer that is coated on the drum surface;
  • Figure 5B is schematic side view of the drum shown in Figure 5A.
  • Figure 5C is a schematic side view of the drum shown in Figure 3B, wherein a buffer layer has been disposed between the drum surface and the continuous substrate.
  • the present invention provides a system for depositing thin films on a continuous substrate or web which is supported by a curved surface of a support base of the system during the deposition.
  • the support base may have a cylindrical shape having a curved surface with a groove region that a continuous substrate is supported during the deposition process. The groove region prevents the substrate from slipping sideways and controls the movement of the substrate.
  • a flexible buffer material is disposed between the substrate and the curved surface of the support base. The flexible buffer material increases the friction between the substrate and the surface of the drum by making a better contact with the substrate and reduces the distortions or quilting caused by the excessive heat. The flexible buffer material can accommodate the small distortion on the substrate and make contact with the full substrate surface. This significantly enhances the heat transfer from the distorted areas of the continuous substrate.
  • a roll to roll system of the present invention may be used to manufacture Group IBIIIAVIA thin film solar cells.
  • Figure 3A shows a roll to roll system 100 with a deposition station 102.
  • the deposition station 102 may be in a chamber or enclosure (not shown).
  • the chamber may or may not be under vacuum.
  • the deposition station includes a support base or drum 104 to support a workpiece 108 during a deposition process.
  • One or more deposition units 106 for a PVD process such as sputter deposition units, is generally positioned across from the lower half of the drum 104.
  • the workpiece 108 contacts a cylindrical peripheral surface 110 of the drum as it is extended between a supply spool 112A and a receiving spool 112B.
  • a number of auxiliary rollers 114 are symmetrically positioned at both sides of the drum to enable workpiece 108 to contact to at least a lower half of the cylindrical peripheral surface 110 as the workpiece is fed from the supply spool 112A and wrapped around the receiving spool 112B after the process.
  • a moving mechanism not shown
  • it is tensioned on the surface 110 of the drum 104 and a front surface 116A of the workpiece 108 receives depositing material from the deposition units 106 while a back surface 116 B of the workpiece 108 is in physical contact with the surface 110 of the drum 104.
  • Both long edges of the workpiece 108 are substantially parallel to the process direction 'A'.
  • the material from the deposition units 106 deposits onto a deposition path on the front surface 116 A of the workpiece 108 as the workpiece is advanced in front of the units 106.
  • the deposition units may include sputter deposition apparatus to sputter-deposit a material onto the front surface 116A of the workpiece.
  • the deposition path may have a width which is equal to or less than the width of the workpiece.
  • the drum 104 in all of the embodiments, is made from a heat conducting material, preferably a metallic material such as stainless steel, though other heat conducting materials can be used.
  • a heat conducting material preferably a metallic material such as stainless steel, though other heat conducting materials can be used.
  • Conventional known methods can be used to make the drums. Modified process steps are required for making the grooves as described above, and additional process steps are used when adding additional materials such as the flexible buffer layer described below. It is noted that the dimension of a typical drum 102 can vary, though in many implementations a diameter of 3-10 ft is typical. A web width of around 2-6 ft is also typical in manufacturing environments.
  • FIG. 3B shows the side cross sectional view of the drum 104.
  • the peripheral surface 110 of the drum 104 includes a groove 118 having a peripheral recessed surface 120A and side walls 120B (a first side wall and a second side wall).
  • the back surface 116B of the workpiece 108 contacts the peripheral recessed surface 120A, also referred to as a workpiece contact surface, and the side walls 120B confine the workpiece 108 within the groove 118.
  • the groove has an unvarying depth across the cylindrical surface 110, which is in the range of the workpiece thickness or greater.
  • the groove 118 enables workpiece to stay in the deposition path and move in the process direction 'A'.
  • the contamination stays on the side walls 120B, and since the workpiece 108 cannot move laterally, no substantial contamination gets underneath the workpiece 108.
  • Contaminated areas of the side walls 120B can be cleaned at process intervals. In this design workpiece 108 will be guided to the groove and the same area will always be kept clean ensuring near constant interaction between the workpiece 108 and the drum 104. Since the workpiece 108 is confined into the groove 118 and moves only in the process direction 'A', the material from the deposition units 106 may be deposited onto the full front surface of the workpiece in an edge to edge manner covering the full width without concerning about any unwanted deposition over the side walls 120B because the side walls are not contacted by the workpiece 108.
  • the groove region of the surface of the drum prevents the workpiece from slipping sideways and controls the movement of the workpiece.
  • the movement of workpiece may also be controlled by a flexible buffer material such as a silicon based polymer material that is disposed between the workpiece and the surface of the drum.
  • the flexible buffer material increases the friction between the workpiece and the drum surface by making a better contact with the back of the workpiece, thereby reducing the distortions or quilting caused by the excessive heat.
  • the buffer material may be used with the drums having grooves as described above as well as with a regular drum with a smooth surface which does not include any groove.
  • Figure 4 A shows a system 200 which is similar to the system 100 except the system 200 uses another drum embodiment and an associated buffer belt assembly.
  • the system 200 is constructed with replacing the drum 104 of the system 100 in Figures 3A-3B with a drum 204 without a groove and also including a buffer belt assembly 201 to provide buffer material.
  • a cylindrical surface 210 of the drum 204 is a smooth surface without a groove.
  • a buffer belt 202 is positioned between the surface 210 of the drum and the back surface 116B of the workpiece 108.
  • the buffer belt 202 is tensioned by a belt roller 203 which may move vertically.
  • the width of the buffer belt 202 may preferably be equal to the width of the surface 210 of the drum 204.
  • the width of the buffer belt may be equal to or greater than the width of the workpiece 108.
  • sides 205 of the buffer belt 202 may be exposed, not covered by the workpiece 108.
  • the exposed sides 205 collect the unwanted deposited material and keep edge surfaces 206 of the drum 204 free from contaminants or excess deposited material.
  • Surfaces of the sides 205 of the buffer belt may be made rough while a surface section of the buffer belt 202 that goes under the workpiece 108 may have a smooth surface for better heat transfer.
  • a smooth surface in the application may have a surface roughness (peak to valley) of 50-250 nm.
  • a roughened surface that collects the excess deposited material or contaminants may have a surface roughness in the range of tens of micrometers up to a millimeter.
  • Such rough surfaces are typically obtained by plasma spraying a material such as aluminum on the surface to be roughened. This way the rough surfaces of the exposed sides 205 may help to collect a greater amount of contaminants before they are cleaned and thereby reduce the number of process interruptions for cleaning.
  • the buffer belt 202 may comprise a material that is flexible yet thermally very efficient conductor such as silicones filled with high thermal conductivity materials.
  • a flexible belt will make a better contact with the workpiece 108 and reduce the distortions or quilting caused by excessive heat.
  • the buffer belt 202 may accommodate the small distortion on the workpiece 108 and make contact with full back surface 116 B of the workpiece. This buffer belt 202 will significantly enhance the heat transfer from distorted areas of the workpiece 108 compared to solid surfaces in the prior art.
  • the buffer belt 202 can be driven by a motorized roll or be driven by the drum; the tension on the belt can be controlled by the belt roller 203, for example the buffer belt 202 can have a constant tension setting with spring such that it can move close or away from the drum 210 freely to keep the constant tension; the buffer belt 210 can have an edge guide to control its precise position on the drum; and the belt can be cleaned or replaced once exposed sides receive significant deposits.
  • the buffer belt 202 may be replaced with a pair of cleaning belts (not shown) which may only touch and cover the edge surfaces 206 of the drum 204 but not extend under the workpiece 108 so that the back surface 116B of the workpiece touch and cover the surface area between the edge surfaces 206.
  • the surface of the cleaning belts may be rough to collect the contaminants. Cleaning belts may be cleaned at intervals or replaced with the clean ones.
  • the system 200 may also use the drum 104, which is described in the previous embodiment, in combination with the buffer belt 202 described above.
  • the buffer belt 202 is between the recessed surface 120A and the back surface 116B of the workpiece 108.
  • the side walls 120B confines the workpiece 108 and the buffer belt 200 within the groove 118.
  • the buffer belt 202 shown in Figure 4 A may be replaced with a buffer material layer 300 that is coated on the entire cylindrical surface 210 that touches the workpiece 108 for the same effect.
  • the width of the buffer layer 300 may preferably be equal to the width of the surface 210 of the drum 204.
  • the width of the buffer layer 300 may be equal to or greater than the width of the workpiece 108. If the width of the buffer layer 300 is greater than the width of the workpiece, sides of the buffer layer 300 may be exposed, not covered by the workpiece 108.
  • the buffer layer may also be employed on the surface 110 of the drum 104 shown in Figure 3B.
  • the buffer layer 300 is between the recessed surface 120A and the back surface 116B of the workpiece 108.
  • the side walls 120B and the buffer layer 300 confine the workpiece 108 within the groove 118.
  • the buffer layer 300 functions the same way as the buffer belt 202 shown in Figure 4C.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Theoretical Computer Science (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Power Engineering (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Computer Hardware Design (AREA)
  • Electromagnetism (AREA)
  • Metallurgy (AREA)
  • Human Computer Interaction (AREA)
  • General Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Organic Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Computer Graphics (AREA)
  • Multimedia (AREA)
  • Physical Vapour Deposition (AREA)

Abstract

A roll to roll system for depositing a material on a workpiece is provided. In one embodiment, the system includes a drum, which rotates about an axis that is transverse to a process direction, and a number of PVD deposition units. The drum further includes a peripheral surface that includes a groove having a recessed workpiece contact surface that is parallel to the axis and disposed between a first side wall and a second side wall. A portion of the recessed workpiece contact surface supports a section of the workpiece and the first and second side walls maintain the section of the workpiece on the portion of the recessed workpiece contact surface as the workpiece is moved along the process direction. The PVD deposition units are disposed across from some of the portion of the peripheral surface and continuously deposit the material across a width of some of the section of the workpiece.

Description

IMPROVED DRUM DESIGN FOR WEB PROCESSING
Inventors: Mustafa Pinarbasi, Homayoun Talieh and Bulent M. Basol
BACKGROUND
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Application No.: 61/109, 144 filed October 28, 2008 entitled "IMPROVED DRUM DESIGN FOR WEB PROCESSING", the entire contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates to deposition methods and, more particularly, to methods for physical vapor deposition of metallic thin films on a conductive surface for manufacturing solar cells.
DESCRIPTION OF THE RELATED ART
[0003] Solar cells are photovoltaic devices that convert sunlight directly into electrical power. The most common solar cell material is silicon, which is in the form of single or polycrystalline wafers. However, the cost of electricity generated using silicon-based solar cells is higher than the cost of electricity generated by the more traditional methods. Therefore, since early 1970' s there has been an effort to reduce cost of solar cells for terrestrial use. One way of reducing the cost of solar cells is to develop low-cost thin film growth techniques that can deposit solar-cell- quality absorber materials on large area substrates and to fabricate these devices using high- throughput, low-cost methods.
[0004] Group IBIIIAVIA compound semiconductors comprising some of the Group IB (Cu, Ag, Au), Group IIIA (B, Al, Ga, In, Tl) and Group VIA (O, S, Se, Te, Po) materials or elements of the periodic table are excellent absorber materials for thin film solar cell structures. Especially, compounds of Cu, In, Ga, Se and S which are generally referred to as CIGS(S), or Cu(In,Ga)(S,Se)2 or CuIn^xGax (SySei_y)k , where O≤x≤l, 0<y<l and k is approximately 2, have already been employed in solar cell structures that yielded conversion efficiencies approaching 20%. Absorbers containing Group IIIA element Al and/or Group VIA element Te also showed promise. Therefore, in summary, compounds containing: i) Cu from Group IB, ii) at least one of In, Ga, and Al from Group HIA, and iii) at least one of S, Se, and Te from Group VIA, are of great interest for solar cell applications.
[0005] The structure of a conventional Group IBIIIAVIA compound photovoltaic cell such as a Cu(In,Ga,Al)(S, Se5Te)2 thin film solar cell is shown in Figure 1. The device 10 is fabricated on a substrate 11, such as a sheet of glass, a sheet of metal, an insulating foil or web, or a conductive foil or web. The absorber film 12, which includes a material in the family of Cu(In,Ga,Al)(S,Se,Te)2, is grown over a conductive layer 13 or contact layer, which is previously deposited on the substrate 11 and which acts as the electrical contact to the device. The absorber film 12 is formed by depositing a precursor layer including Group IB and Group IIIA elements on the contact layer and then reacting this precursor stack film with one of Se and S to form the absorber layer. The substrate 11 and the conductive layer 13 form a base 20 on which the absorber film 12 is formed. Various conductive layers comprising Mo, Ta, W, Ti, and their nitrides have been used in the solar cell structure of Figure 1. If the substrate itself is a properly selected conductive material, it is possible not to use a contact layer 13, since the substrate 11 may then be used as the ohmic contact to the device. After the absorber film 12 is grown, a transparent layer 14 such as a CdS, ZnO or CdS/ZnO stack is formed on the absorber film. Radiation 15 enters the device through the transparent layer 14. Metallic grids (not shown) may also be deposited over the transparent layer 14 to reduce the effective series resistance of the device.
[0006] A variety of materials, deposited by a variety of methods such as evaporation, electroplating and sputter deposition, can be used to provide the various layers of the device shown in Figure 1. Sputtering and evaporation techniques, which are also known as physical vapor deposition (PVD) techniques, are the preferred methods to deposit contact layers and transparent layers, although they may be used to deposit the components of the precursor films also. Such layers can be deposited on a continuous flexible substrate using a well known roll to roll process tool in which the flexible substrate is fed from a supply roll into a process chamber and after receiving deposition the flexible substrate is taken up from the process chamber and wrapped around a receiving roll. The process chamber can have for example one or more sputter deposition units or cathodes to deposit a desired material onto the continuous flexible substrate from the targets mounted on the cathodes. [0007] In general, the process chambers are equipped with a support apparatus to support the continuous flexible substrate during the deposition. Figure 2 shows in perspective view of an exemplary cylindrical support apparatus 50 or drum, supporting a continuous flexible workpiece 52 or web. Drums with various sizes are used to control the tension of the web and to transfer the heat out of the web. The drums can be using oil, water, or gas based cooling mechanisms to transfer heat from the web that gets heated by the sputtering cathodes. Top surface 54 of the web 52 is exposed to the depositing material (depicted as arrows "M") originating from the target materials mounted on the cathodes. During the process, the web 52 is advanced while in contact with the curved surface 56 of the drum 50 which can rotate as the workpiece moves. The quality of the deposited film depends upon the physical contact between the web and the drum surface. As shown in Figure 2, the curved surface 56 is a perfectly cylindrical surface.
[0008] During the process, small distortions in the web may disturb the physical contact between the web and the curved surface which may cause the web to move non-uniformly such as side ways, and/or up and down on the curved surface. Distortions in the web can be caused by the process temperature. Such distortions in turn affect the quality of the deposited layer and cause contamination of an edge area 58 of the curved surface 56, which further deteriorate the physical contact between the web and the curved surface as the web edge contacts this contaminated edge of the curved surface. As a result, an improved drum design is needed to address the above described issues so that more optimal process results may be obtained.
SUMMARY OF THE INVENTION
[0009] The present invention provides a method an apparatus for the confinement of the web in a specific section of a drum, a better web contact with cooled surfaces, and depositing on the full width of the web on the drum.
[0010] In a first embodiment, the drum has a groove that guides the web. This allows the web to be confined to specific section of the drum that is kept free of deposits. With this approach, full width of the web can be deposited. Since the web is confined to groove, deposition on the drum takes place on the sides of the web. Since these areas are not travelled by the web, deposits can be removed with known methods without impacting the interaction between the web and the drum.
[0011] In a second embodiment, a buffer material in the form of a buffer belt or a buffer layer is placed between the drum and the web. The buffer material can be highly conductive yet flexible material. The width of the buffer material can be wide enough to capture all deposition flux. Once significant deposition is made either the buffer material can be cleaned or replaced with a new one.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Figure 1 is a schematic view of a prior art solar cell structure; [0013] Figure 2 is a perspective view of a prior art;
[0014] Figures 3A is a schematic view of a roll to roll deposition system of the present invention having a drum to support a continuous substrate, wherein the drum surface includes a groove to guide the continuous substrate;
[0015] Figure 3B is schematic side view of an embodiment of the drum shown in Figure 3A;
[0016] Figures 4 A is a schematic view of another embodiment of a roll to roll deposition system of the present invention having a drum to support a continuous substrate, wherein the drum includes a smooth surface, and wherein a buffer belt has been disposed between the drum surface and the continuous substrate;
[0017] Figure 4B is schematic side view of the drum shown in Figure 4A;
[0018] Figure 4C is a schematic side view of the drum shown in Figure 3B, wherein a buffer belt has been disposed between the drum surface and the continuous substrate;
[0019] Figures 5A is schematic view of the roll to roll system shown in Figure 4A, wherein the buffer belt has been replaced with a buffer layer that is coated on the drum surface;
[0020] Figure 5B is schematic side view of the drum shown in Figure 5A; and
[0021] Figure 5C is a schematic side view of the drum shown in Figure 3B, wherein a buffer layer has been disposed between the drum surface and the continuous substrate.
DETAILED DESCRIPTION OF THE INVENTION
[0022] The present invention provides a system for depositing thin films on a continuous substrate or web which is supported by a curved surface of a support base of the system during the deposition. In one embodiment the support base may have a cylindrical shape having a curved surface with a groove region that a continuous substrate is supported during the deposition process. The groove region prevents the substrate from slipping sideways and controls the movement of the substrate. In another embodiment, a flexible buffer material is disposed between the substrate and the curved surface of the support base. The flexible buffer material increases the friction between the substrate and the surface of the drum by making a better contact with the substrate and reduces the distortions or quilting caused by the excessive heat. The flexible buffer material can accommodate the small distortion on the substrate and make contact with the full substrate surface. This significantly enhances the heat transfer from the distorted areas of the continuous substrate. A roll to roll system of the present invention may be used to manufacture Group IBIIIAVIA thin film solar cells.
[0023] Figure 3A shows a roll to roll system 100 with a deposition station 102. The deposition station 102 may be in a chamber or enclosure (not shown). The chamber may or may not be under vacuum. The deposition station includes a support base or drum 104 to support a workpiece 108 during a deposition process. One or more deposition units 106 for a PVD process, such as sputter deposition units, is generally positioned across from the lower half of the drum 104. The workpiece 108 contacts a cylindrical peripheral surface 110 of the drum as it is extended between a supply spool 112A and a receiving spool 112B. A number of auxiliary rollers 114 are symmetrically positioned at both sides of the drum to enable workpiece 108 to contact to at least a lower half of the cylindrical peripheral surface 110 as the workpiece is fed from the supply spool 112A and wrapped around the receiving spool 112B after the process. As the workpiece 108 is advanced along a process direction 'A' by a moving mechanism (not shown), it is tensioned on the surface 110 of the drum 104 and a front surface 116A of the workpiece 108 receives depositing material from the deposition units 106 while a back surface 116 B of the workpiece 108 is in physical contact with the surface 110 of the drum 104. Both long edges of the workpiece 108 are substantially parallel to the process direction 'A'. The material from the deposition units 106 deposits onto a deposition path on the front surface 116 A of the workpiece 108 as the workpiece is advanced in front of the units 106. The deposition units may include sputter deposition apparatus to sputter-deposit a material onto the front surface 116A of the workpiece. The deposition path may have a width which is equal to or less than the width of the workpiece.
[0024] The drum 104, in all of the embodiments, is made from a heat conducting material, preferably a metallic material such as stainless steel, though other heat conducting materials can be used. Conventional known methods can be used to make the drums. Modified process steps are required for making the grooves as described above, and additional process steps are used when adding additional materials such as the flexible buffer layer described below. It is noted that the dimension of a typical drum 102 can vary, though in many implementations a diameter of 3-10 ft is typical. A web width of around 2-6 ft is also typical in manufacturing environments.
[0025] Figure 3B shows the side cross sectional view of the drum 104. In this embodiment the peripheral surface 110 of the drum 104 includes a groove 118 having a peripheral recessed surface 120A and side walls 120B (a first side wall and a second side wall). As the workpiece moved during the process, the back surface 116B of the workpiece 108 contacts the peripheral recessed surface 120A, also referred to as a workpiece contact surface, and the side walls 120B confine the workpiece 108 within the groove 118. The groove has an unvarying depth across the cylindrical surface 110, which is in the range of the workpiece thickness or greater. The groove 118 enables workpiece to stay in the deposition path and move in the process direction 'A'. If any contamination happens, the contamination stays on the side walls 120B, and since the workpiece 108 cannot move laterally, no substantial contamination gets underneath the workpiece 108. Contaminated areas of the side walls 120B can be cleaned at process intervals. In this design workpiece 108 will be guided to the groove and the same area will always be kept clean ensuring near constant interaction between the workpiece 108 and the drum 104. Since the workpiece 108 is confined into the groove 118 and moves only in the process direction 'A', the material from the deposition units 106 may be deposited onto the full front surface of the workpiece in an edge to edge manner covering the full width without concerning about any unwanted deposition over the side walls 120B because the side walls are not contacted by the workpiece 108.
[0026] In the above embodiment, the groove region of the surface of the drum prevents the workpiece from slipping sideways and controls the movement of the workpiece. The movement of workpiece may also be controlled by a flexible buffer material such as a silicon based polymer material that is disposed between the workpiece and the surface of the drum. The flexible buffer material increases the friction between the workpiece and the drum surface by making a better contact with the back of the workpiece, thereby reducing the distortions or quilting caused by the excessive heat. The buffer material may be used with the drums having grooves as described above as well as with a regular drum with a smooth surface which does not include any groove. [0027] Figure 4 A shows a system 200 which is similar to the system 100 except the system 200 uses another drum embodiment and an associated buffer belt assembly. The system 200 is constructed with replacing the drum 104 of the system 100 in Figures 3A-3B with a drum 204 without a groove and also including a buffer belt assembly 201 to provide buffer material. As shown in Figure 4B, in this embodiment a cylindrical surface 210 of the drum 204 is a smooth surface without a groove. A buffer belt 202 is positioned between the surface 210 of the drum and the back surface 116B of the workpiece 108. The buffer belt 202 is tensioned by a belt roller 203 which may move vertically. The width of the buffer belt 202 may preferably be equal to the width of the surface 210 of the drum 204. The width of the buffer belt may be equal to or greater than the width of the workpiece 108. If the width of the buffer belt 202 is grater than the width of the workpiece, sides 205 of the buffer belt 202 may be exposed, not covered by the workpiece 108. The exposed sides 205 collect the unwanted deposited material and keep edge surfaces 206 of the drum 204 free from contaminants or excess deposited material. Surfaces of the sides 205 of the buffer belt may be made rough while a surface section of the buffer belt 202 that goes under the workpiece 108 may have a smooth surface for better heat transfer. A smooth surface in the application may have a surface roughness (peak to valley) of 50-250 nm. A roughened surface that collects the excess deposited material or contaminants may have a surface roughness in the range of tens of micrometers up to a millimeter. Such rough surfaces are typically obtained by plasma spraying a material such as aluminum on the surface to be roughened. This way the rough surfaces of the exposed sides 205 may help to collect a greater amount of contaminants before they are cleaned and thereby reduce the number of process interruptions for cleaning.
[0028] The buffer belt 202 may comprise a material that is flexible yet thermally very efficient conductor such as silicones filled with high thermal conductivity materials. A flexible belt will make a better contact with the workpiece 108 and reduce the distortions or quilting caused by excessive heat. The buffer belt 202 may accommodate the small distortion on the workpiece 108 and make contact with full back surface 116 B of the workpiece. This buffer belt 202 will significantly enhance the heat transfer from distorted areas of the workpiece 108 compared to solid surfaces in the prior art. Furthermore, the buffer belt 202 can be driven by a motorized roll or be driven by the drum; the tension on the belt can be controlled by the belt roller 203, for example the buffer belt 202 can have a constant tension setting with spring such that it can move close or away from the drum 210 freely to keep the constant tension; the buffer belt 210 can have an edge guide to control its precise position on the drum; and the belt can be cleaned or replaced once exposed sides receive significant deposits. In another embodiment, the buffer belt 202 may be replaced with a pair of cleaning belts (not shown) which may only touch and cover the edge surfaces 206 of the drum 204 but not extend under the workpiece 108 so that the back surface 116B of the workpiece touch and cover the surface area between the edge surfaces 206. The surface of the cleaning belts may be rough to collect the contaminants. Cleaning belts may be cleaned at intervals or replaced with the clean ones.
[0029] As shown in Figure 4C, the system 200 may also use the drum 104, which is described in the previous embodiment, in combination with the buffer belt 202 described above. In this embodiment, the buffer belt 202 is between the recessed surface 120A and the back surface 116B of the workpiece 108. The side walls 120B confines the workpiece 108 and the buffer belt 200 within the groove 118.
[0030] As shown in Figures 5A-5B, the buffer belt 202 shown in Figure 4 A may be replaced with a buffer material layer 300 that is coated on the entire cylindrical surface 210 that touches the workpiece 108 for the same effect. The width of the buffer layer 300 may preferably be equal to the width of the surface 210 of the drum 204. The width of the buffer layer 300 may be equal to or greater than the width of the workpiece 108. If the width of the buffer layer 300 is greater than the width of the workpiece, sides of the buffer layer 300 may be exposed, not covered by the workpiece 108.
[0031] As shown in Figure 5C, the buffer layer may also be employed on the surface 110 of the drum 104 shown in Figure 3B. In this embodiment, the buffer layer 300 is between the recessed surface 120A and the back surface 116B of the workpiece 108. The side walls 120B and the buffer layer 300 confine the workpiece 108 within the groove 118. In this embodiment, the buffer layer 300 functions the same way as the buffer belt 202 shown in Figure 4C.
[0032] Although the present invention is described with respect to certain preferred embodiments, modifications thereto will be apparent to those skilled in the art.

Claims

We Claim:
1. A system for depositing a material on a continuous flexible workpiece advanced in a process direction, comprising:
at least one drum that rotates about an axis that is transverse to the process direction, the at least one drum further including a peripheral surface that includes a groove formed therein, thereby resulting in a recessed workpiece contact surface that is parallel to the axis and which is disposed between a first side wall and a second side wall, wherein a portion of the recessed workpiece contact surface supports a section of the continuous flexible workpiece and the first and second side walls maintain the section of the continuous flexible workpiece on the portion of the recessed workpiece contact surface as the continuous flexible workpiece is moved along the process direction; and
at least one deposition unit disposed across from some of the portion of the peripheral surface, the at least one deposition unit continuously depositing the material across a width of some of the section of the continuous flexible workpiece.
2. The system of Claim 1 further comprising a supply roll from which the continuous flexible workpiece is advanced in the process direction towards the at least onedrum, and a receiving roll that the continuous flexible workpiece received from the at least one drum is wrapped around.
3. The system of Claim 1, wherein the at least onedrum has a cylindrical shape and the recessed workpiece contact surface has a cylindrical shape.
4. The system of Claim 1, wherein the at least one deposition unit comprises a sputter deposition apparatus.
5. The system of Claim 3, wherein the drum is cooled by a fluid, thereby providing for transfer of heat from the continuous flexible workpiece to the at least one drum while the at least one deposition unit continuously deposits the material across the width of some of the section of the continuous flexible workpiece.
6. The system of Claim 2 further comprising a chamber to enclose the at least one drum and the at least one deposition unit.
7. The system of Claim 6, wherein the chamber is a vacuum chamber.
8. The system of Claim 1, further including a plurality of rollers positioned along the process direction to stabilize the continuous flexible workpiece prior to and after the continuous flexible workpiece supports the recessed workpiece contact surface of the at least one drum.
9. The system of Claim 1, wherein the at least one drum includes one or more drums disposed along the process direction.
10. A system for depositing a material on a continuous flexible workpiece advanced in a process direction, comprising: at least one drum that rotates about an axis that is transverse to the process direction, the at least one drum further including a peripheral surface that is parallel to the axis and which extends from a first edge to a second edge; a buffer film that is flexible and highly thermally conductive that covers at least a portion of the peripheral surface to support a section of the continuous flexible workpiece, wherein the portion of the peripheral surface covered by the buffer film extends from the first edge to the second edge of the peripheral surface; and at least one deposition unit disposed across from the portion of the peripheral surface, the at least one deposition unit continuously depositing the material across a width of some of the section of the continuous flexible workpiece.
11. The system of Claim 10 further comprising a supply roll from which the continuous flexible workpiece is advanced in the process direction towards the support device, and a receiving roll that the continuous flexible workpiece received from the at least one drum is wrapped around.
12. The system of Claim 10, wherein the at least one drum has a cylindrical shape and the peripheral surface has a cylindrical shape.
13. The system of Claim 10, wherein the at least one deposition unit comprises a sputter deposition apparatus.
14. The system of Claim 12, wherein the at least one drum is cooled by a fluid, thereby providing for transfer of heat from the continuous flexible workpiece to the drum while the at least one deposition unit continuously deposits the material across the width of some of the section of the continuous flexible workpiece.
15. The system of Claim 11 further comprising a chamber to enclose the at least one drum and the at least one deposition unit.
16. The system of Claim 15, wherein the chamber is a vacuum chamber.
17. The system of Claim 10, wherein the buffer film is a belt shaped buffer film tensioned by a tension roller to push the buffer film against the peripheral surface of the at least one drum.
18. The system of Claim 17 wherein the belt shaped buffer film is made from silicone filled with a high thermal conductivity material.
19. The system of Claim 10, wherein the buffer film is a buffer coating applied onto entire peripheral surface of the at least one drum.
20. The system of Claim 19 wherein the buffer coating is made from silicone filled with a high thermal conductivity material.
21. The system of Claim 19, wherein the buffer coating is a high friction material.
22. A method of depositing a material on a continuous flexible workpiece advanced in a process direction through a deposition chamber, comprising: advancing the continuous flexible workpiece along a process direction and into the deposition chamber, wherein disposed in the deposition chamber is: at least one drum that rotates about an axis that is transverse to the process direction, the at least one drum further including a peripheral surface that includes a groove formed therein, thereby resulting in a recessed workpiece contact surface that is parallel to the axis and which is disposed between a first side wall and a second side wall; and at least one deposition unit disposed across from some of the portion of the peripheral surface, supporting a back surface of the section of the continuous workpiece with a portion of the recessed workpiece contact surface, while the first and second side walls maintain the section of the continuous flexible workpiece on the portion of the recessed workpiece contact surface as the continuous flexible workpiece is moved along the process direction; depositing the material onto an exposed surface of the section of the continuous flexible workpiece from the at least one deposition unit as the back surface of the section of the continuous flexible workpiece is supported by the portion of the recessed workpiece contact surface.
23. The method of Claim 22, wherein the depositing deposits the material across an entire width of the exposed surface of the section of the continuous flexible workpiece and no material deposition occurs on the recessed workpiece contact surface.
24. The method of Claim 23, wherein when the depositing deposits the material, deposition of excess material occurs on the first and second side walls.
25. The method of Claim 24 further comprising the step of cleaning the excess material from the first and second side walls at process intervals.
26. The method of Claim 22, wherein the step of depositing comprises sputter deposition.
27. A method of depositing a material on a continuous flexible workpiece advanced in a process direction through a deposition chamber, comprising: advancing the continuous flexible workpiece along a process direction and into the deposition chamber, wherein disposed in the deposition chamber is: at least one drum that rotates about an axis that is transverse to the process direction, the at least one drum further including a peripheral surface that is parallel to the axis and which extends from a first edge to a second edge; a buffer film that is flexible and highly thermally conductive that covers at least a portion of the peripheral surface to support a section of the continuous flexible workpiece, wherein the portion of the peripheral surface covered by the buffer film extends from the first edge to the second edge of the peripheral surface; and at least one deposition unit disposed across from the portion of the peripheral surface, supporting a back surface of the section of the continuous workpiece with a portion of the buffer film and the portion of the peripheral surface therebelow as the continuous flexible workpiece is moved along the process direction; depositing the material onto an exposed surface of some of the section of the continuous flexible workpiece from the at least one deposition unit as the back surface of the section of the continuous flexible workpiece is supported by portion of the buffer film and the portion of the peripheral surface therebelow as the continuous flexible workpiece is moved along the process direction.
28. The method of Claim 27, wherein the depositing deposits the material across an entire width of the exposed surface of the section of the continuous flexible workpiece.
29. The method of Claim 28, wherein when the depositing deposits the material, deposition of excess material occurs on buffer film edge regions.
30. The method of Claim 27, wherein the step of depositing comprises sputter deposition.
31. The method of Claim 27, wherein the buffer film is a belt shaped buffer film tensioned against the peripheral surface of the at least one drum.
32. The method of Claim 27, wherein the buffer film is a buffer coating applied onto the peripheral surface of the at least one drum.
PCT/US2009/062370 2008-10-28 2009-10-28 Improved drum design for web processing WO2010051311A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP09824095A EP2355920A4 (en) 2008-10-28 2009-10-28 Improved drum design for web processing

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US10914408P 2008-10-28 2008-10-28
US61/109,144 2008-10-28

Publications (1)

Publication Number Publication Date
WO2010051311A1 true WO2010051311A1 (en) 2010-05-06

Family

ID=42129243

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2009/062370 WO2010051311A1 (en) 2008-10-28 2009-10-28 Improved drum design for web processing

Country Status (4)

Country Link
US (1) US20100147677A1 (en)
EP (1) EP2355920A4 (en)
TW (1) TW201027769A (en)
WO (1) WO2010051311A1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111210734A (en) * 2020-03-18 2020-05-29 Oppo广东移动通信有限公司 Folding screen assembly, display device and electronic equipment
CN111326070A (en) * 2018-12-17 2020-06-23 上海和辉光电有限公司 Flexible display device and mobile terminal
US11740728B2 (en) 2014-05-06 2023-08-29 Semiconductor Energy Laboratory Co., Ltd. Electronic device

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110065282A1 (en) * 2009-09-11 2011-03-17 General Electric Company Apparatus and methods to form a patterned coating on an oled substrate
JP5987312B2 (en) 2011-12-16 2016-09-07 日本電気硝子株式会社 Film forming apparatus and method for manufacturing glass film with film
JP6233262B2 (en) * 2014-09-30 2017-11-22 住友金属鉱山株式会社 Long film transport and cooling roll, and long film processing apparatus equipped with the roll
JP6662192B2 (en) * 2015-12-25 2020-03-11 日本電気硝子株式会社 Glass ribbon film forming apparatus and glass ribbon film forming method
DE102018215100A1 (en) * 2018-05-28 2019-11-28 Sms Group Gmbh Vacuum coating apparatus, and method for coating a belt-shaped material

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3183563A (en) * 1962-06-05 1965-05-18 Temescal Metallurgical Corp Apparatus for continuous foil production by vapor deposition
US4321299A (en) * 1977-09-15 1982-03-23 Nasa Strong thin membrane structure for use as solar sail comprising substrate with reflective coating on one surface and an infra red emissivity increasing coating on the other surface
US20070181430A1 (en) * 1997-04-04 2007-08-09 Cohen Adam L Method For Electrochemical Fabrication
US20070237894A1 (en) * 2006-04-06 2007-10-11 First Solar U.S. Manufacturing, Llc System and method for transport

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2442443A (en) * 1944-12-09 1948-06-01 Bakelite Corp Apparatus for pressing plastic sheeting
US2971862A (en) * 1957-04-26 1961-02-14 Nat Res Corp Vapor deposition method and apparatus
EP0122092A3 (en) * 1983-04-06 1985-07-10 General Engineering Radcliffe Limited Vacuum coating apparatus
US4479862A (en) * 1984-01-09 1984-10-30 Vertimag Systems Corporation Sputtering
US4723507A (en) * 1986-01-16 1988-02-09 Energy Conversion Devices, Inc. Isolation passageway including annular region
JP3708729B2 (en) * 1998-11-18 2005-10-19 富士通株式会社 Semiconductor memory device
JP2000163965A (en) * 1998-11-27 2000-06-16 Mitsubishi Electric Corp Synchronous semiconductor storage
WO2004032189A2 (en) * 2002-09-30 2004-04-15 Miasolé Manufacturing apparatus and method for large-scale production of thin-film solar cells
KR100824670B1 (en) * 2006-11-28 2008-04-28 한국기계연구원 Self aligned multi turn type apparatus for manufacturing thin film tape

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3183563A (en) * 1962-06-05 1965-05-18 Temescal Metallurgical Corp Apparatus for continuous foil production by vapor deposition
US4321299A (en) * 1977-09-15 1982-03-23 Nasa Strong thin membrane structure for use as solar sail comprising substrate with reflective coating on one surface and an infra red emissivity increasing coating on the other surface
US20070181430A1 (en) * 1997-04-04 2007-08-09 Cohen Adam L Method For Electrochemical Fabrication
US20070237894A1 (en) * 2006-04-06 2007-10-11 First Solar U.S. Manufacturing, Llc System and method for transport

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP2355920A4 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11740728B2 (en) 2014-05-06 2023-08-29 Semiconductor Energy Laboratory Co., Ltd. Electronic device
CN111326070A (en) * 2018-12-17 2020-06-23 上海和辉光电有限公司 Flexible display device and mobile terminal
CN111210734A (en) * 2020-03-18 2020-05-29 Oppo广东移动通信有限公司 Folding screen assembly, display device and electronic equipment

Also Published As

Publication number Publication date
EP2355920A1 (en) 2011-08-17
TW201027769A (en) 2010-07-16
EP2355920A4 (en) 2012-11-14
US20100147677A1 (en) 2010-06-17

Similar Documents

Publication Publication Date Title
US20100147677A1 (en) Drum design for web processing
EP2013382B1 (en) Composition control for roll-to- roll processed photovoltaic films
US8088224B2 (en) Roll-to-roll evaporation system and method to manufacture group IBIIAVIA photovoltaics
US20100140078A1 (en) Method and apparatus for forming contact layers for continuous workpieces
US6974976B2 (en) Thin-film solar cells
US8318530B2 (en) Solar cell buffer layer having varying composition
US8163090B2 (en) Methods structures and apparatus to provide group VIA and IA materials for solar cell absorber formation
KR20100126717A (en) Process for making solar cells
WO2009045565A1 (en) Roll to roll evaporation tool for solar absorber precursor formation
US20110108099A1 (en) Method of forming transparent zinc oxide layers for high efficiency photovoltaic cells
US10367116B2 (en) Method of reducing sodium concentration in a transparent conductive oxide layer of a semiconductor device
AU2013242984A1 (en) Method for producing thin-film solar modules and thin-film solar modules which are obtainable according to said method
WO2009111052A1 (en) Heating for buffer layer deposition
WO2009111054A1 (en) Solution containment during buffer layer deposition
US20100186812A1 (en) Photovoltaic devices including copper indium gallium selenide
EP2702615B1 (en) Method of preparing a solar cell
US20140099750A1 (en) Solution containment during buffer layer deposition
US20130061803A1 (en) Roll-To-Roll PVD System and Method to Manufacture Group IBIIIAVIA Photovoltaics
US20140138243A1 (en) In-line deposition system with enhanced adhesion of molybdenum on bottom shield
WO2015092543A2 (en) Solution containment during buffer layer deposition
Andriesh et al. Controlled deposition of CIGSE solar cells
Sledz Investigation on improvements of TCO processing on cadmium telluride thin film solar cells

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 09824095

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 2009824095

Country of ref document: EP

NENP Non-entry into the national phase

Ref country code: DE