Gas cushion apparatus and technique for substrate coating

Abstract

To provide a gas cushion apparatus and technique for substrate coating.SOLUTION: Coating can be provided on a substrate. Fabrication of the coating can include forming a solid layer in a specified region of the substrate while supporting the substrate in a coating system by using a gas cushion. For example, liquid coating can be printed over the specified region while the substrate is supported by the gas cushion. The substrate can be held for a specified duration after printing patterned liquid. The substrate can be conveyed to a treatment zone while supported by using the gas cushion. The liquid coating can be treated to provide the solid layer while continuing to support the substrate by using the gas cushion.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] (Priority Claim) This application claims the benefit of priority to (1) U.S. Provisional Patent Application No. 61 / 986,868, filed April 30, 2014, entitled "Systems and Methods for the Fabrication of Inkjet Printed Encapsulation Layers," and (2) U.S. Provisional Patent Application No. 62 / 002,384, filed March 23, 2014, entitled "DISPLAY DEVICE FABRICATION SYSTEMS AND TECHNIQUES USING INERT ENVIRONMENT," each of which is incorporated herein by reference in its entirety. [Background technology]

[0002] Material layers can be formed on substrates, such as to provide one or more functional or non-functional layers of an electronic device. In one approach, film layers on such devices can be fabricated, in part, through vacuum deposition of a series of thin films onto the substrate using any of several techniques, including, but not limited to, chemical vapor deposition, plasma-enhanced chemical vapor deposition, sputtering, electron beam evaporation, and thermal evaporation. However, such vacuum processing is relatively (1) complex, typically involving large vacuum chambers and pumping subsystems to maintain such vacuum; (2) waste of deposited raw material, as most of the material in such systems typically deposits on the interior walls and fixtures of the deposition chamber, and more material is typically wasted than is deposited on the substrate; and (3) difficult to maintain, such as involving frequent shutdowns of the vacuum deposition tool to open walls and fixtures and clear accumulated waste material. For substrates that generally have a larger surface area than available silicon wafers, these issues pose additional challenges.

[0003] In some applications, it may be desirable to deposit a film in a specific pattern. In another approach, a blanket coating can be deposited over the substrate and photolithography can be considered to achieve the desired patterning. However, in various applications, such photolithography processes can damage the existing deposited film layer. To directly pattern the deposited layer when using vacuum deposition techniques, so-called shadow masks can be used. The shadow mask in such cases comprises a physical stencil with cutouts for the deposition areas, which can be manufactured, for example, from a metal sheet. The shadow mask is generally aligned to the substrate prior to deposition, placed in close proximity or contact with it, kept in place during deposition, and then removed after deposition.

[0004] Such direct patterning with shadow masks adds substantial complexity to vacuum-based deposition techniques, generally involving additional mechanisms and fixturing to precisely handle and position the mask relative to the substrate, further increasing material waste (due to waste from material deposited on the shadow mask) and further increasing the maintenance needs to continually clean and replace the shadow mask. Such thin masks can be mechanically unstable over large areas, limiting the maximum size of substrates that can be processed, and thus, in this case again, these problems are particularly challenging for substrates that generally have larger surface areas than available silicon wafers. Summary of the Invention [Means for solving the problem]

[0005] Embodiments of the enclosed coating system according to the present teachings can be useful for coating substrates in the manufacture of a variety of apparatuses and devices within a wide range of technical fields, such as, but not limited to, organic light emitting diode (OLED) displays, OLED lighting, organic photovoltaic cells, perovskite solar cells, printed circuit boards, and organic and inorganic semiconductor devices or circuits.

[0006] The inventors have recognized that a solid layer can be formed on a substrate at ambient pressure at or near atmospheric pressure, such as by, among other things, depositing liquid ink over certain areas of the substrate using printing techniques and treating the liquid ink to solidify the liquid ink to provide a solid layer (including supporting the substrate at least in part using a gas cushion during such printing, and continuing to support the substrate at least in part using a gas cushion during the treatment of the liquid ink). The inventors have also recognized that, among other things, in this manner, some handling steps can be eliminated, such as to reduce delays, for example, to reduce mechanical damage to the substrate during engagement by a handler, or to enhance the uniformity of the solid layer provided by various embodiments of the coating system of the present teachings. Various processes that can be performed with embodiments of the coating system of the present teachings can include holding the substrate for a certain duration after such printing and before the treatment of the liquid ink (including continuing to support the substrate at least in part using a gas cushion during the various processes performed).

[0007] Broadly, the printing operation can include one or more liquid coating processes, such as inkjet printing, nozzle printing, slot-die coating (patterned or non-patterned), or screen printing, and the liquid ink can include one or more of an organic material (e.g., monomer or polymer) or an inorganic material, and can include a carrier fluid. Treatment of the liquid ink can include one or more of exposure to light (e.g., including one or more of ultraviolet, infrared, or visible light), heating or cooling, and above ambient pressure or vacuum. Such treatment can result in solidification of the liquid ink to provide a solid layer through one or more of removal of the carrier fluid (e.g., one or more of drying or vacuum baking, including vacuum drying or vacuum baking), chemical reaction (e.g., cross-linking, or chemical conversion of one compound to another), or densification (e.g., baking, including vacuum baking). The printed layer can be patterned or blanket coated over a substrate and can cover or be included as part of a light emitting device (e.g., a display or lighting panel), a light absorbing device (e.g., a photodetector or solar cell), a printed circuit assembly, or other electronic device or circuit.

[0008] The inventors have recognized that printing techniques and other processing operations can be performed using a system having an enclosure configured to provide, among other things, a controlled environment (such as including an atmosphere containing a gas having a particular purity level that is minimally reactive or non-reactive with one or more species deposited on or comprising the substrate being processed). Such particular purity levels can also include controlled maximum impurity concentrations of species that react with various materials and components of devices fabricated using embodiments of the coating system of the present teachings, such as, for example, but not limited to, oxygen, ozone, and water vapor, as well as various organic solvent vapors. Controlling various reactive species to particular purity levels can prevent degradation of materials and devices fabricated on the substrate during fabrication, reduce or prevent incorporation of impurities into materials and devices fabricated on the substrate during fabrication, or inhibit or suppress defects that may later cause, accelerate, or promote degradation of such materials or devices after fabrication. Particulate matter control can also be provided, such as to maintain a particular particulate matter level within the controlled environment.

[0009] An array of enclosures can include each module having an individually maintained and controlled environment, or one or more of the modules can share a controlled environment with other modules. Equipment such as gas purification, temperature control, solvent elimination, or particulate matter control can be shared between modules or can be provided in a dedicated manner. Various examples of gas purification according to the present teachings can include maintaining levels for various reactive species, including various reactive atmospheric gases such as water vapor, oxygen, ozone, and organic solvent vapors, at or below 1000 ppm, e.g., at or below 100 ppm, at or below 10 ppm, at or below 1.0 ppm, or at or below 0.1 ppm.

[0010] A variety of devices, such as electronic or optoelectronic devices, can be fabricated using organic materials, including using processing techniques to provide one or more film layers. Organic optoelectronic devices can be compact in volume due to their relatively thin planar structure, while offering enhanced power efficiency and enhanced visual performance, such as compared to other display technologies. Such devices can be mechanically flexible (e.g., foldable or bendable) or optically transparent, unlike competing technologies. Applications of organic optoelectronic devices can include, for example, use as general illumination, backlight illumination sources, or as pixel light sources or other elements in electroluminescent displays. One type of organic optoelectronic device includes organic light emitting diode (OLED) devices, which can generate light using electroluminescent organic materials, such as, for example, small molecule, polymer, fluorescent, or phosphorescent materials.

[0011] In an embodiment, the printing operation can include inkjet printing a liquid ink including an organic material, and treating the liquid ink can include exposing the liquid ink to light, such as ultraviolet (UV) light, to cure the liquid ink to provide a solid layer. A curing process, such as including UV exposure, can induce a cross-linking reaction, thereby forming a patterned solid layer. For example, the patterned solid layer can cover at least a portion of a light emitting device or other device fabricated on the substrate. The solid layer can encapsulate certain regions on the substrate, such as those included in a stack of layers that form an encapsulation structure.

[0012] The systems and techniques described herein can be used to help process a variety of different substrate configurations. For example, flat panel display devices can be fabricated, at least in part, using the systems or techniques described herein. Such flat panel display devices can include organic light emitting diode (OLED) flat panel displays. Some OLED flat panel displays can be processed on substrates. The use of the term "substrate" or the phrase "substrate being fabricated" generally refers to an assembly in process that can include an OLED device. The embodiments herein need not be limited to a particular panel geometry or size. For example, such systems and techniques can be used to help fabricate display devices on substrates having a second generation ("Gen 2") size, such as having a rectangular geometry including dimensions of about 37 centimeters (cm) by about 47 cm. The systems described herein can also be used for slightly larger substrate geometries, such as to help fabricate display devices on substrates having a third generation ("Gen 3.5") substrate size, such as having a rectangular geometry including dimensions of about 61 centimeters (cm) by about 72 cm. The systems described herein can also be used for larger substrate geometries, such as to aid in the fabrication of display devices on substrates having substrate sizes corresponding to "Gen 5.5" substrates having dimensions of approximately 130 cm by 150 cm, or "Gen 7" or "Gen 7.5" substrates having dimensions of approximately 195 cm by 225 cm. For example, a Gen 7 or Gen 7.5 substrate can be singulated (e.g., cut or otherwise separated) into eight 42-inch (diagonal) or six 47-inch (diagonal) flat panel displays. A "Gen 8" substrate can include dimensions of approximately 216 by 246 cm. A "Gen 8.5" substrate can include dimensions of approximately 220 cm by 250 cm and can be singulated to provide six 55-inch or eight 46-inch flat panels per substrate.

[0013] Using the systems and techniques described herein, dimensions greater than Gen 8.5 can be supported. For example, using at least in part the systems and techniques described herein, a "Gen 10" substrate having dimensions of about 285 cm x 305 cm or greater can be fabricated. The panel sizes described herein are generally applicable to glass substrates, but can be applied to substrates of any material suitable for use in display device fabrication, particularly OLED display fabrication, which can include forming one or more layers using printing techniques. For example, various glass substrate materials can be used, as well as various polymer substrate materials, such as polyimide. For example, the present application provides the following: (Item 1) 1. A method of providing a coating on a substrate, the method comprising: transferring a substrate to a coating system, the coating system configured to provide a solid layer in a specific area on a first side of the substrate, the solid layer covering at least a portion of the substrate; supporting the substrate within the coating system using a gas cushion provided on a second side of the substrate opposite the particular area; printing a liquid coating over the specific area of ​​the substrate using a printing system while the substrate is supported by the gas cushion, the substrate being located within a print zone; transporting the substrate to a treatment zone while continuing to support the substrate using the gas cushion; providing said solid layer on said substrate in said specific area by disposing said liquid coating in said coating system while continuing to support said substrate using said gas cushion; A method comprising: (Item 2) the solid layer comprises at least a portion of an encapsulation structure; Item 10. The method of item 1, wherein the substrate comprises an electronic device and the encapsulation structure is established on the substrate to encapsulate at least a portion of the electronic device. (Item 3) 2. The method of claim 1, wherein treating the liquid coating comprises polymerizing the liquid coating. (Item 4) 2. The method of claim 1, comprising, after printing the liquid coating, holding the substrate for a specified duration while continuing to support the substrate using the gas cushion. (Item 5) transporting the substrate to a holding zone to hold the substrate for the specified duration; 5. The method according to claim 4, further comprising: (Item 6) 6. The method of claim 5, comprising using a holding zone configured to hold and support a plurality of substrates using the gas cushion. (Item 7) 2. The method of claim 1, wherein treating the liquid coating comprises irradiating the liquid coating with light. (Item 8) 8. The method of claim 7, wherein the light comprises ultraviolet (UV) light. (Item 9) 8. The method of claim 7, wherein irradiating the liquid coating with light comprises baking the liquid coating with radiation. (Item 10) 8. The method of claim 7, wherein irradiating the liquid coating with light comprises drying the liquid coating with radiation. (Item 11) 2. The method of claim 1, wherein treating the liquid coating comprises one or more of exposing the substrate to infrared radiation or to a temperature-controlled gas flow. (Item 12) 2. The method of claim 1, wherein the particular area on the first side of the substrate overlaps with an active area of ​​the substrate comprising an electronic device, and the gas cushion is provided on the second side of the substrate opposite the active area. (Item 13) 2. The method of claim 1, wherein transporting the substrate comprises engaging or gripping the substrate using physical contact with the substrate. (Item 14) 2. The method of claim 1, wherein the gas cushion is established by forcing a gas through the porous ceramic material to support the second side of the substrate above the porous ceramic material. (Item 15) 2. The method of claim 1, wherein the gas cushion within the print zone is established using a combination of a region of pressurized gas and at least a partial vacuum. (Item 16) 16. The method of claim 15, wherein at least one of the pressurized gas or the exhaust gas used to establish the gas cushion is recovered and recirculated. (Item 17) 1. A method of providing a coating on a substrate, the method comprising: transferring a substrate to an enclosed coating system configured to provide a solid layer in a particular area on a first side of the substrate, the solid layer covering at least a portion of an electronic device being fabricated on the substrate; supporting the substrate within the enclosed coating system using a gas cushion provided on a second side of the substrate opposite the particular area; printing a liquid coating over the specific area of ​​the substrate while the substrate is supported by the gas cushion, the substrate being located within a print zone that includes a printing system; transporting the substrate to a treatment zone while continuing to support the substrate using the gas cushion; The gas cushion is used to continue to support the substrate while treating the liquid coating in the treatment zone, thereby forming a solidified layer on the substrate in the specific area. Providing a body layer A method comprising: (Item 18) 20. The method of claim 17, wherein treating the liquid coating comprises one or more of baking or drying the liquid coating to provide the solid layer. (Item 19) 20. The method of claim 18, wherein treating the liquid coating comprises one or more of exposing the substrate to infrared radiation or exposing it to a temperature controlled gas flow. (Item 20) 20. The method of claim 17, wherein treating the liquid coating comprises solidifying the liquid coating through one or more of inducing a chemical reaction or removing a carrier fluid contained in the liquid coating. (Item 21) Item 18. The method of item 17, wherein the solid layer comprises at least a part of an encapsulation structure established on the substrate to encapsulate at least a part of the electronic device. (Item 22) 20. The method of claim 17, comprising transporting the substrate to a holding zone and holding the substrate for a specified duration while continuing to support the substrate using the gas cushion. (Item 23) 1. A coating system for providing a solid layer on a substrate, the system comprising: a platform configured to support the substrate using a gas cushion, the platform configured to transport the substrate along the platform; a printing system configured to deposit a liquid coating in a specific area on a first side of the substrate while the substrate is supported by the gas cushion on a second side of the substrate opposite the first side when the substrate is located within a print zone of the platform; a treatment system configured to provide a solid layer on the substrate in the particular area by treating the deposited liquid while the substrate is supported by the gas cushion when the substrate is located within a treatment zone of the platform; Equipped with A coating system, wherein the platform is configured to continuously support the substrate during printing operations in the print zone and during treatment operations in the treatment zone. (Item 24) the solid layer comprises at least a portion of an encapsulation structure; 24. The coating system of claim 23, wherein the substrate comprises an electronic device and the encapsulation structure is established on the substrate to encapsulate at least a portion of the electronic device. (Item 25) 24. The coating system of claim 23, wherein the treatment system includes a light source, the source configured to irradiate the liquid coating to provide the solid layer. (Item 26) 26. The coating system of claim 25, wherein the source comprises an ultraviolet (UV) source. (Item 27) 26. The coating system of claim 25, wherein the source comprises an infrared source. (Item 28) 24. The coating system of claim 23, wherein the treatment system is configured to one or more of bake or dry the liquid coating to provide the solid layer. (Item 29) 29. The coating system of claim 28, wherein the treatment system is configured to solidify the liquid coating through one or more of inducing a chemical reaction or removing a carrier fluid contained in the liquid coating. (Item 30) 24. The coating system of claim 23, wherein the platform is configured to hold the substrate for a specific duration after the printing operation and before the treating operation while continuing to support the substrate using the gas cushion. (Item 31) 31. The coating system of claim 30, wherein the platform includes a holding zone separate from the print zone and the treatment zone, the holding zone configured to hold the substrate for the specified duration while continuing to support the substrate using the gas cushion. (Item 32) 24. The coating system of claim 23, comprising an enclosure housing the printing system, the treatment system, and the platform, the enclosure being established to remain below specified limits for particulate contaminant contamination levels, water vapor content, oxygen content, and ozone content in a controlled processing environment at or near atmospheric pressure. (Item 33) 24. The coating system of claim 23, wherein the particular area on the first side of the substrate overlaps with an active area of ​​the substrate comprising an electronic device, and the platform is configured to provide gas to the second side of the substrate opposite the active area. (Item 34) 24. The coating system of claim 23, wherein the platform is configured to engage or grip the substrate using physical contact with the substrate to transport the substrate. (Item 35) 24. The coating system of claim 23, wherein the gas cushion is established by forcing a gas through the porous ceramic material to support the second side of the substrate above the porous ceramic material. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 generally illustrates an example of a plan view of at least a portion of a coating system. [Diagram 2] FIG. 2 generally illustrates an example of a plan view of at least a portion of a coating system that may include two or more print zones and treatment zones. [Figure 3A] 3A-3D generally illustrate further examples of plan views of at least a portion of a coating system. [Figure 3B] 3A-3D generally illustrate further examples of plan views of at least a portion of a coating system. [Figure 3C] 3A-3D generally illustrate further examples of plan views of at least a portion of a coating system. [Figure 3D] 3A-3D generally illustrate further examples of plan views of at least a portion of a coating system. [Figure 4A] FIG. 4A generally illustrates a technique, such as a method, that may include forming a patterned solid layer on a substrate, such as may include using a system shown in the embodiments of FIGS. 1, 2, or 3A-3D. [Figure 4B] FIG. 4B generally illustrates a technique, such as a method, that may include forming an organic encapsulation layer (OEL), such as may include using the system shown in the embodiments of FIGS. 1, 2, or FIGS. 3A-3D. [Diagram 5] FIG. 5 generally illustrates an example depicting various regions of a substrate. [Figure 6]FIG. 6 generally illustrates a schematic diagram of a gas purification scheme that may be used in connection with some or all of one or more other embodiments described herein, such as to establish or maintain a controlled environment within an enclosure. [Figure 7] FIG. 7 generally illustrates an example of at least a portion of a system for coordinating and controlling one or more gas or air sources, such as for establishing a flotation control zone included as part of a flotation transport system. [Figure 8A] 8A and 8B include illustrative examples of chuck configurations that can establish a pressurized gas cushion to support a substrate, such as during one or more of a deposition (e.g., printing), holding, or treatment process, and corresponding uniformity in the resulting processed substrate, FIG. 8C. [Figure 8B] 8A and 8B include illustrative examples of chuck configurations that can establish a pressurized gas cushion to support a substrate, such as during one or more of a deposition (e.g., printing), holding, or treatment process, and corresponding uniformity in the resulting processed substrate, FIG. 8C. [Figure 8C] 8A and 8B include illustrative examples of chuck configurations that can establish a pressurized gas cushion to support a substrate, such as during one or more of a deposition (e.g., printing), holding, or treatment process, and corresponding uniformity in the resulting processed substrate, FIG. 8C. [Figure 9] FIG. 9 illustrates an example of a schematic diagram illustrating a treatment system that may be configured to expose a substrate to light (e.g., ultraviolet light) that may be used in treating a coating on the substrate. [Figure 10A] 10A and 10B generally illustrate an example of at least a portion of a treatment system that may include a linear arrangement of light sources such as may be used in treating a coating on a substrate. [Figure 10B]10A and 10B generally illustrate an example of at least a portion of a treatment system that may include a linear arrangement of light sources such as may be used in treating a coating on a substrate. [Figure 11A] 11A and 11B generally illustrate a diagram of a portion of such a system including a transfer module that can be included as part of a coating system or can be used to manipulate substrates before or after processing by the coating system. [Figure 11B] 11A and 11B generally illustrate a diagram of a portion of such a system including a transfer module that can be included as part of a coating system or can be used to manipulate substrates before or after processing by the coating system. [Figure 12] FIG. 12 generally illustrates a portion of a system including a further example of a transfer module that can be included as part of a coating system or can be used to manipulate substrates before or after processing by the coating system. [Figure 13A] 13A and 13B generally illustrate a view of a portion of a system that may include a stacked configuration of substrate processing regions that may be used in processing a substrate. [Figure 13B] 13A and 13B generally illustrate a view of a portion of a system that may include a stacked configuration of substrate processing regions that may be used in processing a substrate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] FIG. 1 generally illustrates an example of a plan view of at least a portion of a coating system 2600. The system 2600 can be configured to provide a solid layer in a particular area of ​​a substrate, such as a first side of the substrate facing upward. The solid layer can cover at least a portion of the substrate, such as formed in a particular pattern. The system 2600 can include an array of zones, each configured to support the substrate, at least in part, using a gas cushion arrangement that uses pressurized gas provided to a second side of the substrate opposite the first side. For example, the solid layer can be patterned or blanket coated over the substrate and can cover or be included as part of a light emitting device (e.g., a display or lighting panel), a light absorbing device (e.g., a photodetector or solar cell), a printed circuit assembly, or other electronic device or circuit.

[0016] The coating system 2600 can include a printing system 2000, which can include an inkjet printhead configured to deposit a liquid coating over specific regions of a substrate (e.g., providing a blanket or patterned liquid coating). For example, the printing system 2000 can include an apparatus for reliable placement of ink droplets over specific locations on a substrate. Such an apparatus can include one or more of a printhead assembly 2501, an ink delivery system, a substrate support apparatus such as a platform (e.g., a levitating "table") that provides pressurized gas, loading and unloading apparatus, and equipment for managing the printhead.

[0017] In the illustrative embodiment of FIG. 1, the printing system 2000 can include a bridge 2130 mounted to a riser. The bridge can support a first carriage assembly 2301 and a second carriage assembly 2302, such carriages being movable in at least one axis (e.g., the “X-axis”) along the bridge 2130. The first carriage assembly can control the movement of the printhead assembly 2501 across the bridge 2130, such as using a linear air bearing motion system, which can be inherently low particle generating. In an embodiment, one or more of the first or second carriage assemblies 2301 or 2302 can have a vertical (e.g., the “Z-axis”) movement plate mounted thereon. In an embodiment, each of the first and second carriage assemblies 2301 and 2302 can carry a printhead assembly. In another embodiment as shown in FIG. 1, a first carriage assembly 2301 can carry a print head assembly 2501 and a second carriage assembly 2302 can carry one or more cameras, such as camera 2303, for monitoring or inspecting the substrate coating operation.

[0018] Each printhead assembly, such as printhead assembly 2501, can have multiple printheads mounted in at least one printhead device. The printhead device can include, for example, but is not limited by, fluid or electronic connections to at least one printhead, each printhead having multiple nozzles or orifices capable of ejecting ink at a controlled rate, velocity, and size. For example, printhead assembly 2501 can include from about 1 to about 60 printhead devices, and each printhead device can include from about 1 to about 30 printheads within each printhead device. A printhead, such as an industrial inkjet head, can have from about 16 to about 2048 nozzles capable of ejecting droplet volumes of from about 0.1 picoliters (pL) to about 200 pL, according to an illustrative embodiment.

[0019] As mentioned above, the printing operation can include one or more liquid coating processes such as inkjet printing, nozzle printing, slot die coating (patterned or non-patterned), or screen printing, and the liquid ink can include one or more of an organic material (e.g., a monomer or polymer) or an inorganic material and can include a carrier fluid. Treatment of the liquid ink can include one or more of exposure (e.g., including one or more of ultraviolet, infrared, or visible light), heating or cooling, and above ambient pressure or vacuum. Such treatment can result in solidification of the liquid ink to provide a solid layer through one or more of removal of the carrier fluid (e.g., one or more of drying or vacuum baking, including vacuum drying or vacuum baking), chemical reaction (e.g., cross-linking, or chemical conversion of one compound to another), or densification (e.g., baking, including vacuum baking). In another approach, the solid phase material can be thermally evaporated for deposition on the substrate through jetting. In yet another approach, the material can be dissolved or otherwise suspended in a carrier liquid, and a layer containing the material can be formed by dispensing a continuous stream in a fluid state from a nozzle onto a substrate to form lines (so-called "nozzle printing" or "nozzle jetting"), and subsequent evaporation of the carrier to provide a line-patterned layer.

[0020] Region 2100 can be accessed by a handler (e.g., a transfer robot), such as to allow placement of a substrate in region 2100 of the first zone Z1 prior to printing a liquid coating (e.g., as indicated by an arrow pointing to region 2100). The substrate can then be at least partially supported by pressurized gas, such as in region 2100 of the first zone Z1. The printing system can have a second region 2200, such as to provide a combination of pressurized gas and vacuum to more precisely control the levitation "fly height" of the substrate in the first zone Z1, during or after a printing operation, etc. Further discussion of using pressure alone or a combination of pressure and vacuum is provided with respect to the illustrative example of FIG. 7 below.

[0021] Referring again to FIG. 1, the substrate can be transported, at least in part, using a levitating table located in the first zone Z1. Such transport can be augmented or otherwise facilitated by mechanical engagement of the substrate, such as including the use of one or more of rollers or grippers (e.g., vacuum grippers), as discussed further in the examples below. One or more of the first, second, or third zones Z1, Z2, or Z3 can be configured to continuously support the substrate, at least in part, using a gas cushion. For example, after a printing operation, the substrate can be transported, such as through the second zone Z2, such as along a path indicated by a curved line including an arrow, to a third zone Z3 included as part of the treatment system 3000. Such transport can include continuing to support the substrate, at least in part, using a gas cushion during transport and throughout treatment. The treatment system 3000 can treat a liquid coating (e.g., a printed liquid ink) to provide a solid layer on the substrate.

[0022] As mentioned above, treatment of the liquid ink can include one or more of exposure to light (e.g., including one or more of ultraviolet, infrared, or visible light), heating or cooling, and above ambient pressure or vacuum. Such treatment can result in solidification of the liquid ink to provide a solid layer through one or more of removal of the carrier fluid (e.g., one or more of drying or vacuum baking, including vacuum drying or vacuum baking), chemical reaction (e.g., cross-linking or chemical conversion of one compound to another), or densification (e.g., baking, including vacuum baking). The printed layer can be patterned or blanket coated over a substrate and can cover or be included as part of a light emitting device (e.g., a display or lighting panel), a light absorbing device (e.g., a photodetector or solar cell), a printed circuit assembly, or other electronic device or circuit.

[0023] For example, the treatment system 3000 can include one or more light sources (e.g., one or more visible, infrared, or ultraviolet light sources, such as source 910). The source 910 can include a linear array of "bar" sources, such as may include an array of ultraviolet light emitting diodes, as discussed with respect to other embodiments herein. The substrate or one or more of the sources 910 can be translated or scanned, such as to achieve a desired controlled duration or dose of exposure to a particular area of ​​the substrate. Such exposure can be used to heat the substrate (e.g., using infrared or visible light) or to cause a chemical reaction (e.g., cross-linking or chemical transformation). Treatment need not include the use of light. For example, the treatment system 3000 can be configured to heat or cool the substrate, or to provide an environment for the substrate to evolve from one state to another.

[0024] For example, the treatment can include baking or drying the substrate using heating. Such heating can be one or more of convection-driven (e.g., using a gas cushion or establishing other gas flow) or radiation-driven (e.g., using one or more sources such as lamps providing infrared radiation). As discussed in other examples below, the temperature of the substrate during treatment in the treatment zone 3000 or elsewhere can be controlled, such as using one or more of a controlled application of a temperature-controlled gas flow over the substrate surface, such as a laminar flow that can be provided to flow over the face of the substrate, or using a temperature-controlled flow provided as part of a gas cushion used to support the substrate. Such convection techniques can be used to treat the substrate to bake or dry the liquid coating to solidify the liquid coating and provide a solid layer. Such convection techniques can be combined with radiation treatment, such as can include using infrared lamps to perform one or more of the baking or drying of the liquid coating. The treatment can include providing an environment that densifies one or more layers on the substrate, such as can include a baking operation. In another example, at least a partial vacuum environment can be used during treatment, such as can also include radiation treatment of the substrate.

[0025] In an embodiment, the substrate may be held for a particular duration (or until a particular criterion is met) after the printing operation but before the treating operation, such as to allow the substrate to evolve from one state to another. When holding the substrate for the purposes of developing, for example, the substrate may be held to allow the printing liquid layer to settle or flow. In the above embodiment, the temperature of the substrate during such development may be controlled through the controlled application of a temperature-controlled gas flow over the substrate surface, such as a laminar flow that may be provided to flow over the face of the substrate.

[0026] Holding can be performed with the substrate located in either one of the areas 2100 or 2200 of the first zone Z1. For example, the first substrate can be held stationary in the print zone Z1 after the printing operation for a certain holding duration. However, throughput can be increased, such as by conveying the substrate to the second zone Z2 and using at least a portion of the second zone Z2 as a holding zone or to perform one or more other operations. For example, another substrate can be delivered to the first zone Z1 of the system 2600 for a printing operation, and the first substrate can be conveyed to the second zone Z2 to clear the area where printing occurs. If the second zone is elongated, a series of substrates can be held or conveyed sequentially through the zone Z2. The second zone Z2 can also be used to queue or buffer a series of substrates waiting for treatment or other processing (e.g., the substrate does not have to be held in zone Z2 only for a specific duration or for development from one state to another), or a processing can be performed in the second zone Z2, which may include one or more of baking or drying the substrate. Other configurations can also be used, such as those shown in the examples of Figures 2, 3A, 3B, 3C, or 3D. Additionally or alternatively, the third zone Z3 can be used to hold the substrate for a specific duration after printing but before treatment.

[0027] The coating system 2600 can be located within the enclosure 1010, such as to provide a controlled processing environment at or near atmospheric pressure. Such a controlled processing environment can be established to remain below specific limits for one or more of particulate matter contamination levels, water vapor content, oxygen content, ozone content, and organic vapor content. For example, the controlled processing environment can include nitrogen, or another gas or mixture of gases, specified for minimal reactivity or non-reactivity with species to be deposited on the substrate being processed using the system 2600. As described in other embodiments below, such a controlled processing environment can be established at least in part using a gas purification system included within or coupled to various portions of the system 2600. Particulate matter levels of the controlled environment can also be controlled, such as using devices coupled to or located within the system 2600. In embodiments, the enclosure 1010 can include an environment established without a pressurized inert gas recirculation system and can include an enclosure 1010 that is maintained at a slightly positive internal pressure relative to the outside pressure to protect against ingress of outside gas or air into the interior should any leaks develop within the enclosure 1010. According to various illustrative embodiments, the enclosure 1010 and system 2600 of the present teachings, the interior of the enclosure 1010 can be maintained at a pressure of at least 2mbarg, e.g., at least 4mbarg, at least 6mbarg, at least 8mbarg, or higher, relative to the ambient atmosphere outside the enclosure 1010.

[0028] FIG. 2 generally illustrates an example of a plan view of at least a portion of a coating system 2700 that may include two or more print and treatment zones. FIG. 2 may include two or more coating systems 2600A or 2600B, each having a configuration that is the same as or similar to the configuration of the system 2600 discussed above in connection with FIG. 1. In FIG. 2, a substrate 4000 may be transported into zone Z1A of the first coating system 2600A and supported during the printing process at least in part using a gas cushion provided by a levitation table in the print zone Z1A. A handler 2732 including an end effector 1420 may be used to manipulate the substrate 4000, for example, to place the substrate 4000 in a fixed position for a printing or treatment operation in zone Z1A or to retrieve the substrate after such an operation, such as from zone Z3A. In the illustrative example of FIG. 2, the handler 2732 may traverse a track 2734 in addition to having other degrees of freedom.

[0029] The substrate 4000 can be transported within the coating system 2600A using a levitation stage transport system, such as through the second zone Z2A, using various transport techniques. Such techniques can include using one or more of a linear air bearing or mechanical bearing system, a gripper assembly for holding the substrate, rollers, etc. As previously discussed herein, the substrate 4000 can be held within the holding zone for a particular holding duration, such as after the printing process is completed and before a treatment operation, or for a duration determined by the delay of other processing activities. During such holding operations, the substrate 4000 can remain supported, at least in part, using a gas cushion.

[0030] The substrate 4000 can be transported to a treatment zone Z3A such as included as part of the treatment system 3000A. As discussed elsewhere herein, the substrate 4000 can be treated using various techniques, such as to form a solid layer by solidifying a liquid layer. Such treatment can result in solidification of the liquid ink to provide a solid layer through one or more of removal of the carrier fluid (e.g., one or more of drying or vacuum baking, such as vacuum drying or vacuum baking), chemical reaction (e.g., cross-linking or chemical conversion of one compound to another), or densification (e.g., baking, such as vacuum baking). During processing in the coating system 2600A, the substrate 4000 can be supported at least in part using a gas cushion during an entire sequence of processing operations, including one or more of printing, holding, and treating.

[0031] The inventors have recognized that, among other things, in this manner, some handling steps involving robots (e.g., handler 2732) may be eliminated, such as to reduce delays, e.g., to reduce mechanical damage to the substrate during engagement by handler 2713, or to increase uniformity of the solid layer (e.g., film layer) provided by coating system 2600A. The various transport techniques described above can be used to transport the substrate through coating system 2600A, such as to contact the substrate in certain regions other than the display region or areas of the substrate that contain the electronic device being fabricated, or to support the substrate at least partially using a gas cushion opposite such regions.

[0032] The system 2700 can include a second coating system 2600B configured similarly to the first coating system 2600A, including first, second, and third zones Z1B, Z2B, and Z3B, along with the printing system 2000B and the treatment system 3000B. The second coating system 2600B can be configured to print a liquid layer and then treat the liquid layer to provide a solid layer, similar to the first coating system 2600B. In this manner, the second coating system 2600B can provide one or more of redundancy or increased throughput compared to a topology having only a single printing system 2000 or a single coating system 2600A or 2600B. In an embodiment, the solid layer provided by the second coating system 2600B can be different (e.g., in composition or location coated on the substrate) from the layer provided by the first coating system block 2600A.

[0033] The system 2700 may include various enclosures, such as a first enclosure 1010A for the first coating system block 2600A and an enclosure 1010B for the second coating system block 2600B. Each of the enclosures may have a controlled environment, as discussed with respect to other embodiments herein. The handler 2732 may be located in a transfer module 1400B, which may also have a controlled environment. The internal environment of the transfer module 1400B may be maintained in common with one or more of the first or second coating system blocks 2600A or 2600B, or may be maintained separately. For example, one or more gate valves or gas curtain arrangements may be used in the area where the handler 2732 places or retrieves substrates from the first or second coating system blocks 2600A or 2600B.

[0034] The system 2700 can include one or more other modules, such as the first or second module 1100A or 1100B, which can include one or more of a pass-through or load-lock arrangement. For example, the module 1100B (e.g., an "output" module) can include a load-lock arrangement configured to at least partially transfer the substrate 4000 from a first environment in the transfer module 1400B to another environment different from the environment of the transfer module 1400B (e.g., from a pressure at or near atmospheric pressure to / from a vacuum environment to a pressure at or near atmospheric pressure, or from / to an atmospheric environment having different controlled properties, such as one or more of gas, moisture, particulate matter, or other compositions). Similarly, the module 1100A (e.g., an "input module") can include a load-lock arrangement or a pass-through arrangement. Another transfer module 1400A can include a handler 1410, such as for placing the substrate 4000 into or retrieving the substrate 4000 from the module 1100A. Other modules, such as a first processing or holding module 1200A or a second processing or holding module 1200B, can be included. Such processing or holding modules 1200A or 1200B can include a stacked arrangement of locations for substrates 4000, as illustratively shown in the example of FIG. 13A or FIG. 13B. Such a stacked arrangement can be used to hold substrates before or after processing, or for other purposes. In addition to simply holding a substrate for purposes of substrate flow management, such as holding a substrate for a period of time until another module is ready to receive the substrate, or providing a place to hold defective or damaged substrates until the substrate can be removed, a processing or holding module can also be used to hold a substrate for a period of time as part of a functional process flow.

[0035] The first module 1100A or the second module 1100B can be coupled to a vacuum source or a purge source, or both, and can be configured to independently seal the interface ports to the system 2700 and to a previous or next environment (which may be an ambient environment, or a controlled environment associated with another enclosed processing module). In this way, the first or second module 1100A or 1100B can seal the internal environment of the module 1100A or 1100B internally and transition it between being incompatible with the rest of the system 2700 and being compatible (e.g., a controlled environment at about or above atmospheric pressure that, when exposed to the system 2700 via the interface ports, will substantially maintain the quality of the controlled environment within the system 2700B). Similarly, the first module 1100A or the second module 1100B can be used to transfer the substrate to an environment suitable for other processing (e.g., a second environment at or near atmospheric pressure but having a different composition than the controlled environment, or a vacuum environment). In this manner, the first or second module 1100A or 1100B can provide a transfer conduit between the controlled environment of the system 2700 and other equipment. The first module 1100A or other modules can include a permanently mounted configuration or a cart or other transportable configuration.

[0036] In an embodiment, a module (e.g., the first module 1100A or the second loading module 2700) can then be provided with a non-reactive atmosphere or otherwise "filled" using a purified gas flow, such as including one or more purge operations, to prepare the interior region of the loading module (e.g., the first module 1100A or the second module 1100B) for exposure to the interior of the enclosed system 2700. For example, the interior region of one or more of the modules can be at least partially evacuated or purged to avoid contamination in a manner that exceeds certain limits of particulate matter contamination levels, water vapor content, oxygen content, ozone content, and organic vapor content of the controlled processing environment within the enclosed region defined by other portions of the system 2700.

[0037] Similarly, after processing by the system 2700, the substrate being processed can be placed into the first or second module 1100A or 1100B. By way of illustration, a module (e.g., the first module 1100A or the second module 1100B) can be isolated from the non-reactive gas environment elsewhere in the system 2700 and coupled to a vacuum source to be evacuated for subsequent processing under vacuum conditions or otherwise for transport of the substrate being fabricated to other equipment or processing under vacuum conditions, ambient conditions, or some other static controlled environment. By way of further illustration, one of the first or second modules 1100A or 1100B can be configured to provide the substrate to a controlled processing environment in the system 2700 without raising the concentration of reactive species within an enclosed area by, for example, more than 1000 parts per million, or similarly without raising ambient particle levels by more than a certain amount, or depositing on the substrate more than a certain number of particles of a certain size per square meter of substrate area.

[0038] In an embodiment, the first module 1100A can be coupled to the other modules by a port (e.g., including a physical gate with a substantially gas-impermeable seal) or a gas curtain. When the port is open, the interior of the first module 1100A can be accessed by a handler located in the first transfer module 1400A. The handler 1410 can include a robot assembly having various degrees of freedom, such as for manipulating the substrate using an end effector. Such an end effector can include, for example, a fork, tray, or frame configured to support the substrate by gravity, or the end effector can grip, clamp, or otherwise hold the substrate, such as to enable the substrate to be reoriented from an up- or down-facing configuration to one or more other configurations. Other end effector configurations, such as including pneumatic or vacuum-operated features, can be used to either actuate portions of the end effector or otherwise hold the substrate. Further illustrative examples of transfer modules including handlers are described below.

[0039] Other coating system configurations can be used that have similar aspects to the embodiments of FIG. 1 or FIG. 2, but have different line configurations or "topologies". For example, FIGS. 3A-3D generally illustrate further embodiments of plan views of at least a portion of a coating system. FIG. 3A generally illustrates a coating system 2800A that can be referred to as a "U" configuration, such as for providing a liquid layer and treating the liquid layer to provide a solid layer. The system 2800A can include a printing system 2000 having a first zone Z1, including a floating table device configured to support a substrate 4000 at least in part using a gas cushion, as in other embodiments. The second zones Z2A-Z2N can be used as holding or processing areas 5000A-5000N, such as for holding a series of substrates before or after a printing operation, including continuing to support the substrate at least in part using a gas cushion. A treatment system 3000 can be provided having a third zone Z3.

[0040] In an in-line embodiment, the substrate 4000 can be introduced into the system 2800A, such as through the first module 1100A. The substrate can be manipulated by a handler 2732, such as located in the transfer module 1400B, and placed on a levitating table in zone Z1 for a printing operation. The substrate 4000 can be transported along zone Z1 to zones Z2A-Z2N and then transported to zone Z3 for a treatment operation. During the traversal or operation in zones Z1, Z2A-Z2N, and zone Z3, the substrate 4000 can be supported, such as being supported continuously, at least in part using a gas cushion. As described above, in addition to the gas cushion arrangement, other transport techniques can be used. Upon completion of a sequence of at least one printing and treatment operation, the substrate can be retrieved by the handler 2734 and placed into the second module 1100B for further processing, etc. If a second printing system is included, the topology of FIG. 28A can be extended to form an "M" configuration. The inclusion of one or two printing systems (e.g., printing system 2000) is illustrative, and additional printing systems can be included to increase throughput, increase redundancy, provide additional processing operations, etc.

[0041] FIG. 3B generally illustrates a system 2800B that may include a "partial carousel" configuration, such as including a rotating portion 3001 (e.g., a platform, chamber, or other configuration) that can rotate to allow transport of the substrate to various portions of the system 2800B. As in other examples, the substrate 4000 may be introduced to a first module 1100A, etc., where the handler 1410 retrieves the substrate 4000 and places it in zone Z1 for a printing operation. The substrate 4000 may then be transported to one of zones Z2A or Z2B, such as for a holding operation or other processing in a holding or processing region 5000A or 5000B, which may include continuing to support the substrate 4000 at least in part using a gas cushion. The substrate 4000 may be transported back to zone Z1, and then, after rotation of the rotating portion 3001, the substrate 4000 may be transported to zone Z3, such as for a treatment operation. In an embodiment, the substrate 4000 can be transported directly from zone Z1 to zone Z3 without the need for holding or other processing in zones Z2A or Z2B. For example, if zones Z2A or Z2B are occupied, holding or other processing can occur in print zone Z1 or treatment zone Z3. After printing and processing, the substrate can be transported back to a location along zone Z1, such as for retrieval by the handler 1410. The substrate can be returned to module 1100A or placed in another module 1100B, such as for further processing. In other embodiments, other levitating table transport structures can extend radially in other directions other than toward zone Z1.

[0042] 3C illustrates an "arc" topology that may include a transfer module 1400C that connects with various portions of the system 2800C at points located generally radially around the transfer module 1400C. For example, the substrate 4000 may be introduced into the system 2800C, such as through the first module 1100A. The handler 1410 may retrieve the substrate 4000 from the first module 1100A and place it in zone Z1, such as for a printing operation using the printing system 2000. The substrate 4000 may then be transported to a region 5000A in zone Z2A, where it may remain stationary in zone Z2A for a particular duration or traverse zones Z2A-Z2N, including regions 5000A-5000N, for a particular duration. The substrate 4000 can be processed in the treatment area 3000 and then retrieved by the handler 1410, such as for placement back into an output module, such as module 1100A or module 1100B.

[0043] FIG. 3D generally illustrates a further example of a view of at least a portion of a system 2800D that can be used in providing a solid coating on a substrate 4000. The system 2800D can include a stacking configuration for at least a portion of the system. Although the embodiments of FIG. 3A, FIG. 3B, and FIG. 3C generally illustrate a single substrate elevation (e.g., the substrate is transported laterally from operation to operation substantially within the plane of the substrate itself), such an embodiment can be combined with other embodiments described herein that include one or more portions having a stacking configuration. The system 2800D can include a module 1100A, such as an input module, coupled to a transfer module 1400B. The transfer module 1400B can include a handler 2732 that can traverse a track 2734 to access other portions of the system 2800D. The transfer module 1400B can be coupled to other parts of the system 2800, such as module 1100B (eg, an output module), or to one or more other modules, such as holding or processing module 1200A or holding or processing module 1200B.

[0044] The handler 2732 can provide a substrate to a first zone Z1 near the printing system 2000, such as for deposition (e.g., printing) of a liquid ink layer on the substrate 4000. The substrate 4000 can then be transported via the levitation stage transport system 2630 to an identified one of the stacked arrays of zones Z2A-Z2N in the region 5000. Such zones Z2A-Z2N can be lowered or raised, for example, such that the identified one of the stacked arrays is aligned laterally in substantially the same plane of the printing zone Z1 for transport of the substrate. After holding for a certain duration or after undergoing other processing in the region 5000, or until zone Z3 is available, such as included as part of the treatment system 3000, the identified one of zones Z2A-Z2N can be aligned with zone Z3, and the substrate can be transported to zone Z3 via levitation. In the example of FIG. 3D, zone Z3 is shown as having approximately the same elevation as Z1, but this need not be the case. For example, treatment zone Z3 can be at a different elevation than zones Z2A-Z2N or print zone Z1.

[0045] As with other examples above, during operations such as printing or processing in system 2800D, the substrate 4000 may be supported at least in part using a gas cushion throughout the process sequence to reduce one or more of the handling steps or mechanical contact between the substrate 4000 and processing equipment. Without being bound by theory, it is believed that such reduction in handling steps or reduction in mechanical contact involving the handler 2732 may enhance the uniformity of the coating layer, such as by helping to reduce the formation or circulation of particulate contaminants or by helping to reduce non-uniformities across the substrate due to thermal or electrostatic non-uniformities.

[0046] FIG. 4A generally illustrates a technique 6001, such as a method, that can include forming a coating on a substrate, such as can include using the system shown in the examples of FIGS. 1, 2, or 3A-3D. During certain operations, such as during one or more of printing, holding, or handling, the substrate can be supported by a levitation device using pressurized gas or a combination of pressurized gas and vacuum. In 6101, the substrate can be transferred to the coating system. For example, the substrate can have been processed elsewhere and have one or more layers fabricated thereon. As described above, the substrate can include layers that are patterned or blanket coated over the substrate, and such layers can cover or be included as part of a light emitting device (e.g., a display or lighting panel), a light absorbing device (e.g., a photodetector or solar cell), a printed circuit assembly, or other electronic device or circuit.

[0047] In 6201, the substrate can be supported in a coating system, such as at least partially using a gas cushion provided on a side of the substrate opposite an area where a patterned solid layer is to be formed, such as including continuing to support the substrate at least partially using a gas cushion. In 6301, a liquid coating can be deposited on the substrate, such as using a printing technique. Broadly, the printing operation can include one or more liquid coating processes, such as inkjet printing, nozzle printing, slot-die coating (patterned or non-patterned), or screen printing, and the liquid ink can include one or more of an organic material (e.g., a monomer or polymer) or an inorganic material, and can include a carrier fluid.

[0048] Optionally, in 6401, the substrate can be held, such as in an area or zone arranged for such holding (e.g., a zone located along or included as part of the levitation table array). Such holding can occur for a particular fixed duration or can be specified to include a duration sufficient to allow the substrate to transition or develop from one state to another different state. Such holding can also be established, at least in part, by delay or availability of other processing areas, such as treatment areas. During the holding operation, the substrate can continue to be supported, at least in part, by a gas cushion. In 6501, the substrate can be transported to a treatment zone, including continuing to support the substrate, at least in part, using a gas cushion. In an embodiment, the transport in 6501 can occur before the optional holding described in 6401. In another embodiment, the optional holding described in 6401 can occur while the substrate is still located in the print zone.

[0049] In 6601, the liquid coating provided in 6301 can be treated. Treatment of the liquid ink can include one or more of exposure to light (e.g., including one or more of ultraviolet, infrared, or visible light), heating or cooling, and above ambient pressure or vacuum. Such treatment can result in solidification of the liquid ink to provide a solid layer through one or more of removal of the carrier fluid (e.g., one or more of drying or vacuum baking, including vacuum drying or vacuum baking), chemical reaction (e.g., cross-linking or chemical conversion of one compound to another), or densification (e.g., baking, including vacuum baking). In the example of FIG. 4B, such treatment includes exposure to ultraviolet light, such as to provide a patterned solid layer corresponding to one or more areas where the liquid ink was deposited.

[0050] Portions of an electronic device, such as a light emitting or light absorbing device, can be encapsulated using one or more film layers deposited on a device that has been fabricated on a substrate. In an embodiment, such a film layer can include a stack or other configuration of layers including inorganic and organic materials. FIG. 4B generally illustrates a technique 6002, such as a method, that can include forming an organic encapsulation layer (OEL), such as can include using one or more aspects of the coating system shown in the embodiments of FIGS. 1, 2, or 3A-3D. Such an OEL can be included as part of the encapsulation structure.

[0051] In 6102, the substrate can be transferred to an enclosed organic thin film encapsulation system configured to deposit a layer (e.g., a patterned organic layer) in a specific region of a first side of the substrate, the organic layer covering at least a portion of a device to be fabricated on the substrate. In 6202, the substrate can be supported in the enclosed thin film encapsulation system at least in part using a gas cushion provided on a second side of the substrate opposite the specific region. In 6302, while the substrate is at least in part supported by the gas cushion, with the substrate located in the print zone, a liquid ink, which in examples can be an organic monomer-based ink, can be printed (e.g., inkjet printed) over the specific region of the substrate using a print system. In 6402, the substrate can be conveyed to a holding zone, where the substrate can be held for a specific duration, including continuing to support the substrate at least in part using the gas cushion. In 6502, the substrate can be conveyed to a treatment zone, including continuing to support the substrate at least in part using the gas cushion. As described with respect to other embodiments, transport of the substrate to the treatment zone can occur before or after holding, and the holding operation need not occur within the holding zone, for example, such holding can occur instead of or in addition to one or more of the print zone or treatment zone.

[0052] In 6602, the substrate can be treated, including treating a liquid ink, which in embodiments can be an organic monomer-based ink, to provide a polymerized organic layer on the substrate in specific regions, the treating occurring while the substrate remains at least partially supported using a gas cushion. The patterned organic layer can include part of an encapsulation structure, the structure being established to encapsulate at least a portion of the light emitting device on the substrate.

[0053] FIG. 5 generally illustrates an example depicting various regions of a substrate 4000 that may be supported at least in part using pressurized gas ports or regions, or a combination of such pressurized gas with vacuum ports or regions. The substrate 4000 may include a glass material or one or more other materials. In an illustrative example of a flat panel display, the substrate 4000 may include either a single large display, or two or more smaller displays that may be singulated from the substrate 4000. In the illustrative example of FIG. 5, four display regions 4002A, 4002B, 4002C, and 4002D are shown. These may be referred to as, for example, "active regions" or "emissive regions." The use of the term "active" in this example does not imply that such regions are actually optically emissive during processing, but instead refers to regions that may include devices configured to emit light, or that otherwise form an emissive or transmissive portion of a display that is visible to an end user. Generally, visual defects in regions 4002A-4002D are considered unacceptable by the end user, and therefore various techniques can be used, such as to enhance the visual uniformity of regions 4002A-4002D. Other variations in the panel configuration of substrate 4000 are possible. For example, substrate 4000 can include a single display or array of OLED devices. In other embodiments, substrate 4000 can be divided into two, four, or eight regions, establishing corresponding perimeters for support or having corresponding distributed porous media regions as described in other embodiments herein. For other fabrication embodiments in which other devices, such as optical, electrical, or optoelectronic devices, are on the substrate and are coated, such as coated with an organic encapsulation layer, the definition of "active" can be adjusted to suitably encompass the regions corresponding to these devices. Examples of such devices include electronic circuits, solar cells, printed circuit boards, and flat panel displays.

[0054] In an embodiment, support can be provided during processing, such as using a pressurized gas cushion established on a surface below the substrate in the display regions 4002A-4002D. Regions 4004 extending around the periphery of the substrate 4000 and into the interior space between each of the display regions 4002A-4002D can be engaged by physical contact between the substrate and fixtures, which can include one or more of grippers, rollers, lift pins, or other fixtures. Such regions 4004 can be referred to as "keep out" regions, indicating that light-emitting or active elements of a display (or other elements as described above for other types of devices other than displays) can be kept out of such engagement regions (or vice versa). For example, one or more "lift pins" can be located in regions as illustratively shown in FIG. 5, such as in the first region 2124A, the second region 2124B (e.g., at a location between the display regions 4002A and 4002B), and the "Nth" region 2124N. Such lift pins can provide increased clearance between substrate 4000 and one or more ports or distributed pressurized gas sources, such as can be used to support a substrate in regions 4002A, 4002B, 4002C, or 4002D.

[0055] The levitation platform or chuck may include a continuous array of small pressure openings or a continuous porous plate, which allow the passage of pressurized gas over which the substrate may be levitated. For example, holes such as 2124A and 2124B can still be provided in the chuck surface for lift pins (which lie below the chuck surface when retracted), but because the substrate floats above the chuck surface, the presence of irregularities or non-uniformities in the coating covering such holes can be reduced or eliminated. In this way, even the interior regions between regions 4002A-4002D can be utilized as active regions, improving productivity and enabling the manufacture of larger continuous active devices. As yet another example, a combination of pressurized gas ports and vacuum ports can be used, as shown and described elsewhere. For example, the substrate 4000 can be held by one or more vacuum ports (e.g., circular ports, or e.g., slots), such as in regions 2124A-2124N as shown in region 4004.

[0056] As mentioned above, such region 4004 may again include the perimeter of the substrate 4000. In an illustrative embodiment, physical contact between the substrate 4000 and any fixtures may generally be limited to such peripheral region 4004 during other processing operations, such as during one or more of deposition (e.g., printing of material on the substrate 4000), holding, handling, or other processing. Such region 4004 may extend inward from the edge of the substrate by, for example, 100 or 200 millimeters. Elsewhere, the substrate may be at least partially supported in region 4002 using one or more pressurized gas ports. Such a combination of vacuum and pressurized gas ports may avoid exerting undue stress on the large substrate 4000, since the substrate may be physically supported in the peripheral region 4004 and at least partially supported by pressurized gas in the central region 4002. In this manner, it does not matter whether the substrate 4000 includes a single large display being fabricated or includes several smaller displays. Thus, while supporting the substrate 4000 (e.g., at the center) with pressurized gas, contact can be limited to the peripheral area 4004 of the substrate 4000, allowing a common conveyor or levitating table configuration to be used for a variety of different display configurations.

[0057] In processes where the substrate 4000 can only be supported by a gas cushion, a combination of positive gas pressure and vacuum can be applied through an array of ports or distribution areas. Such a zone, with both pressure and vacuum control, can effectively provide a fluid spring between the levitating table or platform and the substrate 4000. The combination of positive pressure and vacuum control can provide a fluid spring with bidirectional stiffness. The gap that exists between the substrate (e.g., substrate 4000) and the surface can be referred to as the "fly height", and such height can be controlled or otherwise established by controlling the positive pressure and vacuum port conditions. In this manner, the orientation of the substrate can be carefully controlled, such as for one or more of printing, holding, handling, or other processes.

[0058] In other locations, such as where the fly height does not need to be precisely controlled, a pressure-only levitation zone can be provided, such as along the conveyor or elsewhere. A "transition" zone can be provided, such as along the conveyor or table, where the ratio of pressure nozzles or area to vacuum nozzles or area gradually increases or decreases. In an illustrative embodiment, within tolerances, there can be an essentially uniform height between the pressure-vacuum zone, transition zone, and pressure-only zone, such that the three zones can essentially lie in one plane. In other locations, the fly height of the substrate 4000 above the pressure-only zone can be greater than the fly height of the substrate 4000 above the pressure-vacuum zone, such as to allow sufficient height so that the substrate does not collide with the levitation table in the pressure-only zone.

[0059] In an illustrative embodiment, the substrate is about 150 micrometers (μ) above the pressure only zone. ~ about 300μ, then may have a flight height of about 10μ to about 50μ above the pressure-vacuum zone. In an illustrative example, one or more portions of the levitating platform or table may include an "air bearing" assembly provided by NewWay® Air Bearings (Aston, Pennsylvania, United States of America) or Coreflow (Israel). An example of gas pressurized support of the substrate is discussed with respect to FIG. 5, although such techniques may be used in addition to or instead of other transport or support approaches.

[0060] 6 illustrates a schematic diagram of a gas purification scheme that may be used in connection with some or all of one or more other embodiments described herein, such as to generally establish or maintain a controlled environment within an enclosure. For example, gas enclosure system 502 may include gas enclosure assembly 100 (e.g., an enclosure having a controlled environment), a gas purification loop 130 in fluid communication with gas enclosure assembly 100, and a thermal conditioning system 140 (e.g., as may be referred to as a temperature controller in other embodiments herein).

[0061] The system 502 can include a pressurized gas recirculation system 300 that can provide gas for operating various devices, such as a substrate levitation table or other pressurized gas devices, such as for various coating system embodiments described herein. The pressurized gas recirculation system 300 can include or use a compressor, a blower, or both. In addition, the gas enclosure system 502 can have a circulation and filtration system (e.g., one or more fan filter units (FFUs) as described in other embodiments herein) internal to the gas enclosure system 502.

[0062] One or more ducts or baffles can separate the non-reactive gas circulated through the gas purification loop 130 from the non-reactive gas that is otherwise filtered and circulated internally for various embodiments of the gas enclosure assembly. For example, the gas purification loop 130 can include an outlet line 131 from the gas enclosure assembly 100. A solvent removal component 132 can be provided for solvent removal, and the gas to be purified can be sent from the solvent removal component 132 to a gas purification system 134. Gas that has been purified to remove the solvent and other reactive gas species, such as one or more of ozone, oxygen, and water vapor, can be circulated back to the gas enclosure assembly 100, such as through an inlet line 133.

[0063] The gas purification loop 130 may include appropriate conduits and connections, such as for interfacing with monitoring or control devices. For example, ozone, oxygen, water vapor, or solvent vapor sensors may be included. Gas circulation units, such as fans, blowers, or other arrangements, may be provided separately or may be incorporated into the gas purification system 134, for example, for circulating gas through the gas purification loop 130. In the illustration of FIG. 6, the solvent removal component 132 and the gas purification system 134 are shown as separate units. However, the solvent removal component 132 and the gas purification system 134 may be housed together as a single unit.

[0064] The gas purification loop 130 of FIG. 6 can have a solvent removal component 132 disposed upstream of the gas purification system 134 such that gas circulated from the gas enclosure assembly 100 can pass through the solvent removal component 132, such as via an outlet line 131. In an embodiment, the solvent removal component 132 can include a solvent trapping system based on absorbing solvent vapor from the gas passing through the solvent removal component 132. For example, one or more beds of adsorbents, such as activated carbon, molecular sieves, etc., can effectively remove a wide variety of organic solvent vapors. In another embodiment, cold trapping techniques can be used to remove solvent vapors as part of the solvent removal component 132. Sensors, such as ozone, oxygen, water vapor, and solvent vapor sensors, can be used to monitor the removal of such species from the gas continuously circulated through a gas enclosure system, such as the gas enclosure system 502. For example, information obtained from such sensors or other devices can indicate when an adsorbent, such as activated carbon, molecular sieves, etc., has reached capacity or is otherwise becoming less effective so that one or more beds of the adsorbent can be regenerated or replaced.

[0065] Regeneration of the molecular sieve can involve heating the molecular sieve, contacting the molecular sieve with forming gas, combinations thereof, and the like. For example, molecular sieves configured to trap various species including ozone, oxygen, water vapor, or solvents can be regenerated by heating and exposure to forming gas. In an illustrative example, such forming gas can include hydrogen, e.g., forming gas includes about 96% nitrogen and about 4% hydrogen, the percentages being by volume or weight. Physical regeneration of activated carbon can be performed using a heating procedure in a controlled environment.

[0066] The gas purification system 134 portion of the gas purification loop 130 may include, for example, systems available from MBRAUN Inc. (Statham, New Hampshire) or Innovative Technology (Amesbury, Massachusetts). The gas purification system 134 may be used to remove and purify one or more gases in the gas enclosure system 502, for example, to remove and purify the entire gas atmosphere in the gas enclosure assembly. As described above, the gas purification system 134 may include a gas circulation unit, such as, for example, a fan or blower, to circulate the gas through the gas purification loop 130. The gas purification system may be selected or configured depending on the volume of the enclosure, which may define a volumetric flow rate for moving the non-reactive gas through the gas purification system. In an illustrative example, the gas enclosure system with the gas enclosure assembly may include a volume of about 4 cubic meters, and a gas purification system may be used that can move about 84 cubic meters per hour. In another illustrative embodiment, a gas enclosure system having a gas enclosure assembly can include a volume of about 10 cubic meters, and a gas purification system capable of moving about 155 cubic meters per hour can be used. In yet another illustrative embodiment, a gas enclosure assembly having a volume of about 52 to about 114 cubic meters, more than one gas purification system can be used.

[0067] Gas filters, dryers, or other purification devices can be included in the gas purification system 134. For example, the gas purification system 134 can include two or more purification devices, arranged in a parallel configuration or otherwise, such that one of the devices can be taken off line for maintenance and one or more of the other devices can be used to continue system operation without interruption. For example, the gas purification system 134 can include one or more molecular sieves, such as at least a first molecular sieve and a second molecular sieve, such that when one of the molecular sieves becomes saturated with impurities or is otherwise deemed not to be operating efficiently enough, the system can switch to the other molecular sieve while regenerating the saturated or inefficient molecular sieve. A control unit can be provided to determine the operating efficiency of each molecular sieve, to switch between the operation of different molecular sieves, to regenerate one or more daughter sieves, or a combination thereof. As previously described, the molecular sieves can be regenerated and reused.

[0068] The thermal conditioning system 140 of FIG. 6 circulates a coolant into the gas enclosure assembly. The gas enclosure system 502 may include at least one cooling device 142, which may have a fluid outlet line 141 for delivering a coolant to the gas enclosure system 502 and a fluid inlet line 143 for returning the coolant to the cooling device. At least one fluid cooling device 142 may be provided to cool the gas atmosphere within the gas enclosure system 502. For example, the fluid cooling device 142 may deliver a cooled fluid to a heat exchanger within the enclosure, and the gas may be passed through a filtration system inside the enclosure. At least one fluid cooling device may also be provided for the gas enclosure system 502 to cool heat generated from the equipment enclosed within the gas enclosure system 502. In an illustrative example, a fluid cooling device may also be provided for the gas enclosure system 502 to cool heat generated from the coating system. The thermal conditioning system 140 may include a heat exchange or Peltier device and may have various cooling capacities. For example, the cooling device may provide a cooling capacity of about 2 kilowatts (kW) to about 20 kW capacity. According to various embodiments, the gas enclosure system 502 can have multiple fluid cooling devices capable of cooling one or more fluids. The fluid cooling devices can use various fluids as the heat transfer medium, such as, for example, water, antifreeze, refrigerant, or combinations thereof. Leak-free locking connections can be used in connecting associated conduits and system components.

[0069] While the above examples describe cooling capacities and applications, the above examples may also be applied to applications involving buffering of substrates in a controlled environment, or where the circulating gas can be maintained at a temperature similar to other parts of the system, such as to avoid unwanted heat transfer from the substrate being fabricated, or to avoid disturbing temperature uniformity across or between substrates.

[0070] FIG. 7 generally illustrates an example of at least a portion of a system 505 for integrating and controlling one or more gas or air sources, such as to establish a levitation control zone included as part of a levitation-based support or transport system. Such a system 505 may include a table 2250 having various regions configured to support a substrate by establishing a gas cushion. In this illustrative example, regions 2100, 2200, and 2300 may be referred to as input, print, and output, for illustrative purposes only. Such regions may be used for other processing steps, such as transporting the substrate, or supporting the substrate, such as during one or more of holding, drying, baking, or other procedures, or other processing of the substrate according to other embodiments. In the illustration of FIG. 7, a first blower 3284A is configured to provide pressurized gas into one or more of the input or output regions 2100 or 2300 of the levitation table apparatus. Such pressurized gas may be temperature controlled, such as using a first cooling device 142A coupled to a first heat exchanger 1502A. Such pressurized gas may be filtered using a first filter 1503 A. A temperature monitor 8701 A may be coupled to the first cooling device 142 (or other temperature controller).

[0071] Similarly, a second blower 3284B can be coupled to the print zone 2200 of the levitating table. A separate cooling device 142B can be coupled to the loop including the second heat exchanger 1502B and the second filter 1503B. A second temperature monitor 8701B can be used to provide independent regulation of the temperature of the pressurized gas provided by the second blower 3284B. In this illustrative example, the input and output zones 2100 and 2300 are provided with positive pressure, but the print zone 2200 can include the use of a combination of positive pressure and vacuum control to provide precise control over the substrate position. For example, using such a combination of positive pressure and vacuum control, the substrate can be exclusively controlled using a levitation gas cushion provided by the system 504 within the zone defined by the print zone 2200. The vacuum can be established by a third blower 3290, which also provides at least a portion of the make-up gas for the first and second blowers 3284A or 3284B within the blower housing 3282.

[0072] 8A and 8B include illustrative examples of chuck or table configurations that can establish a pressurized gas cushion that supports the substrate, such as during one or more of a deposition (e.g., printing), holding, or treatment process, and a corresponding uniformity in the resulting processed substrate 4006C of FIG. 8C. FIG. 8A generally illustrates an example of a chuck 2420B configuration that includes ports configured to establish a pressurized gas cushion that supports the substrate 4006B, such as during one or more of a deposition, holding, material distribution or flow operation, or treatment process. In this approach, the substrate 4006B can avoid large and highly visible unevenness because the substrate 4006B is not required to contact the thermally non-uniform features of the chuck 2420B during various processes. Different port configurations can be used, such as having a first port density in region 2406A and a second port density in region 2406B.

[0073] As described in other embodiments herein, a flight altitude "h" can be established, such as by using a combination of vacuum and pressurized gas ports in the array of regions 2406A and 2406B. For example, in each row of ports, the ports can alternately be assigned as vacuum ports or pressurized gas ports. In this manner, precise control of the altitude h can be established and the substrate 4006B can be established in the z dimension relative to the chuck surface. As in other embodiments herein, a combination of mechanical tethering and pressurized gas can also be used. For example, lateral movement of the substrate 4006B (e.g., in a direction parallel to the surface of the chuck) can be limited, such as by using one or more side stops or bumpers, and transport of the substrate 4006B can be facilitated using one or more rollers or grippers that engage the substrate at the periphery.

[0074] FIG. 8B generally illustrates an example of a chuck configuration including a porous medium 1906, such as to establish a distributed pressure during one or more of deposition, holding, treatment, or other processes, such as to provide uniformity in the resulting substrate 4006C as shown in FIG. 8C. As described with respect to other embodiments herein, a porous medium 1906 "plate" coupled to or included as part of the chuck 2420C or levitation platform can provide a "distributed" pressurized gas cushion to support the substrate 4006C, such as to provide the substrate 4006C shown in FIG. 8C with reduced or minimized formation of mura or other visible defects, without the use of large apertures as shown in FIG. 8A. As described with respect to other embodiments herein, a porous medium 1906 "plate" coupled to or included as part of the chuck 2420C can provide a "distributed" pressure to uniformly levitate the substrate 4006C during processing, such as to provide a substrate 4006C with reduced or minimized formation of mura or other visible defects, without the use of individual apertures as shown in FIG. 8A.

[0075] Porous media 1906, or similar distributed pressure or vacuum regions as described elsewhere herein, having physical dimensions specified to occupy the entire substrate 4006C or a specific region of the substrate, such as the display area or an area outside the display area, can be obtained from Nano TEM Co., Ltd. (Niigata, Japan), etc. Such porous media can include pore sizes specified to provide lift over a specific area while reducing or eliminating mura or other visible defects, such as during holding, handling, or other processing. Without being bound by theory, it is believed that the use of porous media can enhance the uniformity of a coating or film layer on the substrate 4006C, such as by reducing or eliminating mura or other visible defects associated with a non-uniform thermal or electrostatic field profile across the surface of the substrate or on the opposite surface of the coating or film layer. The porous media can be connected to an air supply, such as to provide a gas cushion, or various porous media regions can be connected to air and vacuum supplies, respectively, to provide a gas cushion with a controlled "fly height" within one or more specific zones, such as described above with respect to Figure 7. When such porous media is used to provide a distributed pressure source to levitate the substrate above the chuck surface, the presence of holes for the lift pins (e.g., for retracted lift pins) need not cause visible defects in the resulting coating that is produced while the substrate is supported by the gas cushion, thus making a larger portion of the substrate area available for active region.

[0076] FIG. 9 generally illustrates an example of a schematic illustrating a treatment system that may be configured to expose a substrate to light, such as may be used in treating a coating on the substrate. The treatment system may be included as part of other systems or techniques described herein, such as for use in a curing process or for performing operations including one or more of baking or drying a liquid ink layer to solidify the liquid ink layer to provide a solid layer. The treatment system may include a light source assembly 912 configured to couple energy to a surface of the substrate 4000. The source assembly may include a source configured to emit one or more of ultraviolet (UV), infrared (IR), or visible light. As another example, the treatment system 8314 may include a controlled environment, such as provided by one or more gas purification loops and coupled to one or more fan filter units (FFUs), such as to provide an environment with a specified maximum level of particulate matter or reactive contaminants.

[0077] The substrate 4000 can be transported to the treatment system 8314, such as using a levitation table transport arrangement as described with respect to other embodiments described herein. A table 920 can be used to support the substrate 4000, such as using a gas cushion arrangement as described in other embodiments. One or more lift pins can be used to further raise the substrate 4000, such as to allow the substrate 4000 to be manipulated by an end effector of a handler after treatment (e.g., after formation of a patterned solid layer on the substrate 4000).

[0078] In an illustrative example involving ultraviolet treatment, an array of sources, such as sources 910A-910N, can provide ultraviolet energy including wavelengths selected from a range of about 350 nanometers to about 400 nanometers. For example, wavelengths of about 385 nanometers or about 395 nanometers can be used. The sources can include various configurations, such as using a relatively small number of high power sources or using an array of relatively low power sources. The sources can include commonly available ultraviolet emitters, such as ultraviolet light emitting diodes (UV LEDs), or one or more mercury-based devices, such as one or more mercury arc sources. In another example, the sources 910A-910N can include lamps or other sources capable of emitting one or more of visible light or infrared radiation. For example, the substrate can be thermally treated, such as using an array of infrared radiation sources.

[0079] In an embodiment, the substrate or housing 918 of the source assembly 912 can be liquid or air cooled. For example, a plenum 914 can be provided having one or more fans, such as fan 915, to force air across or through a portion of the source assembly 912. Such a cooling loop can be separate from the controlled environment within the treatment system 8314. The environment surrounding the sources 910A-910N can include the controlled environment of the treatment system 8314, or the environment surrounding the sources 910A-910N can form a separate enclosure, such as having a window 916 that allows energy to pass from the source enclosure to the treatment system 8314. In this way, maintenance of the source enclosure need not disturb the controlled environment within the treatment system 8314.

[0080] The window 916 need not be uniformly transparent. For example, the window can include or be coupled to optics that converge, diverge, or collimate the energy. In another example, the window 916 can include transmission characteristics that vary in a specific manner across the area of ​​the window, such as to invert or otherwise compensate for non-uniform power density of energy delivered within the plane of the substrate 4000, such as within a particular region of the substrate. In the example of FIG. 9, the window and sources 910A-910N are shown as being arranged in a planar configuration, although other configurations are possible, such as cylindrical, parabolic, or spherical configurations. In an example, the sources 910A-910N can be used to treat one or more organic material layers to encapsulate a device that is being fabricated as part of the substrate 4000. Examples of such devices include electronic circuits, solar cells, printed circuit boards, and flat panel displays. Such treatment can include providing a specific dose of ultraviolet energy within a specific range of wavelengths and with a specific uniformity across a specific area of ​​the substrate 4000.

[0081] Treatment processes can generally be established in terms of a desired dose or dose range of ultraviolet light exposure, such as specified in terms of energy per unit area (e.g., joules per square centimeter). The dose can be calculated, such as by multiplying the incident power density by the exposure duration. A trade-off can exist between intensity (e.g., incident power) and exposure duration. For example, a relatively high-power source can be used and the desired dose can be achieved using a relatively short exposure duration, which beneficially shortens the processing time. However, there can be limits on the power density provided at the substrate by the ultraviolet light source, such as to avoid damage or degradation, for example, because high-power UV irradiation can damage or degrade other parts of the display assembly.

[0082] The uniformity of the delivered UV energy can also be controlled, such as to avoid variations in coating layer properties across the surface of the substrate 4000. Uniformity can be specified in terms of incident power or delivered dose, such as having a value of no more than 20% variation from the highest to lowest incident power or dose across a particular cure area of ​​the substrate 4000, or having a value of no more than 50% variation from the highest to lowest incident power or dose across a particular cure area of ​​the substrate 4000, or having a value of no more than 10% variation from the highest to lowest incident power or dose across a particular cure area of ​​the substrate 4000.

[0083] Various source configurations can be used for the sources 910A-910N. For example, a linear array or "bar" source can be used as shown in configuration 8315 of FIG. 10A. Such a bar configuration can include precision reflectors, such as to focus or collimate the energy in a direction toward the substrate 4000. In another embodiment, such a bar configuration can include one or more of a diffuser or a transmissive filter, or a two-dimensional array configuration can be used. One or more of these source configurations can be mechanically fixed or scanned across the surface of the substrate. In such an embodiment, either the substrate 4000 or the sources 910A-910N or both can be scanned. For example, the sources 910A-910N can be fixed and the substrate 4000 can be moved, such as to generate a relative motion between the substrate 4000 and the sources 910A-910N to achieve scanning.

[0084] 10A and 10B generally illustrate at least a portion of a treatment system 8315 that may include a linear arrangement of light sources such as may be used to treat a coating on a substrate. 8 illustrates an embodiment. In an embodiment, the treatment system 8315 can include a linear array configuration 910 of sources. The linear array 910 can be scanned in at least one axis to sweep a radiation beam 922 (e.g., ultraviolet radiation) across a particular region of the substrate 4000. In an illustrative embodiment, such a region can include a region where a liquid ink, which in an embodiment can be an organic monomer-based ink, has been deposited and is to be cured or otherwise treated with ultraviolet light. Such scanning can be accomplished through movement of either the substrate 4000 or the linear array 910 or both, such as during treatment. A window 916 can be used, such as when the linear array 910 is located in an enclosure separate from the chamber 8314 housing the substrate 4000. Such a window 916 can include or be coupled to one or more of an optical section or filter.

[0085] A linear array 910 may provide the advantage of fewer sources (e.g., about 5 to about 10 UV LED sources in an illustrative embodiment). However, such a linear area 910 may introduce additional system complexity if mechanical scanning is used to provide exposure throughout a particular area of ​​the substrate 4000. Mechanical scanning can be simplified, in part, by specifying that the linear array 910 is at least as wide or long as one axis of the substrate. In this way, the entire width or length of the substrate 4000 can be treated with optical radiation while scanning the linear array 910 "gantry" in only a single axis. The linear array 910 may include precision reflector configurations as described above. As an illustrative example, a high-power UV LED light bar providing light at or near a 395 nm wavelength is available from Phoseon Technology (Hillsboro, Oregon, USA), including a reflector configuration that enhances the uniformity of the area illuminated by the linear array 910. In addition to or instead of such precision reflectors, one or more of a filter or diffuser can be used, either statically configured near the window 916 or included as part of the window 916. In another embodiment, one or more of the filters or diffusers can be included as part of the linear array 910 assembly, such as mechanically scanned as part of the linear array 910. In an embodiment, the power density provided by the linear UV source is between 20 mW / cm2 and 400 mW / cm2.

[0086] In FIG. 10B, the linear array 910 source height from the upward facing portion of the substrate 4000 can be represented by “H”, and the relative velocity between the optical energy emitted by the array 910 and the substrate can be represented by “V”. The velocity can be established by one or more of moving the array 910 relative to the substrate 4000 (e.g., mechanically scanning the array), or moving the substrate 4000 relative to the array, such as either by levitating the substrate on a cushion of gas or by moving a chuck 920 that supports the substrate. The irradiated width can be represented by “W”, such width increasing as H increases and decreasing as H decreases. For dose modeling, the width of the array 910 can be multiplied by the irradiated width W to estimate the area of ​​the substrate 4000 irradiated by the array 910.

[0087] In general, given the large-scale substrates 4000 that can be accommodated by the embodiments described herein, throughput is a consideration. Thus, one objective may be to provide a light dose in a manner where an adequate dose is delivered in a short or minimal amount of time, which may also reduce the possibility of damaging other portions of the substrate 4000, either through reducing or minimizing exposure to energy from the source, or simply through reducing or minimizing the time the substrate is being processed. However, tradeoffs may exist between various process parameters, and the speed, dose of energy, and source height H are generally not established arbitrarily.

[0088] The above examples describe various techniques for treating a substrate using light, such as to provide a solid coating layer by treating a printed liquid ink layer. Other treatment techniques can be used, such as may include one or more of heating or cooling the substrate, baking or drying the substrate with radiation, using a gas flow at a higher pressure compared to other parts of the coating system, using a vacuum (or partial vacuum), and combinations thereof. Such treatments can result in solidification of the liquid ink to provide a solid layer through one or more of removal of the carrier fluid (e.g., one or more of drying or vacuum baking, such as including vacuum drying or vacuum baking), chemical reaction (e.g., cross-linking or chemical conversion of one compound to another), or densification (e.g., baking, such as including vacuum baking). As described with respect to other examples herein, temperature control can be achieved using one or more of controlled temperature using pressurized gas supporting the substrate, or gas flow (e.g., laminar flow) established across the surface of the substrate as illustratively shown with respect to FIG. 13B.

[0089] 11A and 11B generally illustrate a view of a portion of the system including a transfer module that can be included as part of the coating system or can be used to manipulate substrates before or after processing by the coating system. The controlled environment in the various enclosures of the system can include controlled particulate matter levels. Particulate matter can be reduced or minimized, such as by using air circulation units and filters, such as may be referred to as fan filter units (FFUs). An array of FFUs can be located along the path traversed by the substrate during processing. The FFUs need not provide a downflow direction of airflow. For example, the FFUs or piping can be positioned to provide a substantially laminar flow laterally across the surface of the substrate. Such laminar flow laterally can enhance or otherwise provide particulate matter control.

[0090] In the example of FIG. 11A or FIG. 11B, one or more fan filter units (FFUs), such as FFUs 1500A, 1500B, 1500C-1500F, can be used to help maintain an environment with a controlled level of particulate matter or contaminants in the transfer module 1400A. Ducts, such as first and second ducts 5201A or 5201B, can be used, such as to provide a return air path as shown in the downstream example of FIG. 11A. A controlled temperature can be maintained at least in part using a temperature controller 8700, such as coupled to one or more heat exchangers 1502. One or more temperature monitors, such as temperature monitor 8701, can be positioned at specific locations (e.g., on or near the substrate or end effector) to provide feedback to help maintain the substrate or an area near the substrate within a specific range of temperature, as discussed below. In an example, the temperature monitor can be a non-contact sensor, such as an infrared temperature monitor, configured to provide information indicative of a surface temperature sampled by the sensor. Other configurations are possible, such as may include locating a heat exchanger in or near the return air duct in the lower portion of the chamber as illustratively shown in FIG. 13B.

[0091] FIG. 12 generally illustrates a portion of such a system including further examples of transfer modules that may be included as part of a coating system or may be used to manipulate substrates before or after processing by a coating system. As in the example of FIG. 11A, transfer module 1400B may include one or more fan filter units (FFUs), such as 1500A-1500N (e.g., 14 FFUs). In contrast to handler 1410A of transfer module 1400A of FIG. 11A, the transfer module may include one or more FFUs, such as 1500A-1500N (e.g., 14 FFUs). The handler in the transfer module 1400B can include a track configuration, such as to provide linear translation of the handler along an axis. A wide range of other chambers or modules can be coupled to the transfer module 1400B, such as in a clustered configuration, without requiring that every other module or chamber be coupled in a radial fashion from a single point. One or more ducts can be located within portions of the transfer module 1400B in areas outside the range of motion of the handler. For example, such a location can be used to provide a return duct that carries gas (e.g., nitrogen) from a lower portion of the transfer module 1400B upward to a plenum above the FFU array.

[0092] 13A and 13B generally illustrate a diagram of at least a portion of such a system that may include a stacked arrangement of areas of a substrate 4000 that may be used to process or hold substrates. The ports of the processing module 1200 may include one or more doors or hatches, such as door 3301. For example, such doors may be mechanically or electrically interlocked such that a door accessible to the exterior of the fabrication system cannot be opened unless a corresponding door elsewhere on or within the system is closed. For example, door 3301 may be used to perform maintenance while the processing module 1200 is otherwise isolated from an inert environment or an environment controlled for particulate matter or contaminants within other enclosed portions of the fabrication system.

[0093] As described above, a particulate or contaminant controlled environment can be maintained, at least in part, using one or more FFUs 1500. In the example of FIG. 13B, a cross-flow configuration is used, such as to maintain a substantially laminar gas (e.g., non-reactive gas) flow across each of one or more cells 3350 that can contain substrates. The heat exchanger 1502 can be, but need not be, located near or as part of the FFU 1500. For example, the heat exchanger 1502 can be located below the substrate handling area, such as included within or as part of the return duct 5201. The temperature can be controlled by a temperature controller 8700, such as coupled to a temperature sensor 8701. The curved profile of the portion of the duct 5201 can be specified, at least in part, using computational fluid dynamics techniques, such as to maintain certain flow characteristics (e.g., laminar flow) within the process module 1200.

[0094] In addition to (or instead of) queuing such substrates, such as until another part of the system is ready to receive the substrate, the processing module 1200 can functionally participate in the substrate fabrication process, for example, by providing a drying function, or by holding the substrate for a certain duration (or until a certain criterion is met) to allow the substrate to evolve from one state to another. In holding the substrate for the purposes of evolving, for example, the substrate can be held to allow liquid to settle or flow. The temperature of the substrate during such evolving can be controlled through the controlled application of a temperature-controlled gas flow over the substrate surface, such as a laminar flow that can be provided to flow over the face of the substrate, as shown in FIG. 13B.

[0095] In general, the holding module temperature need not be the same as the temperature in other parts of the system or in the environment surrounding it. In another embodiment, the substrate may be placed on a cushion of temperature-controlled gas (as in other embodiments described herein, such as where a levitation cushion of gas is used to support the substrate for one or more of printing, holding, or other operations, such as treatment operations, including one or more of radiative baking or drying, convective baking or drying, or exposing the substrate to light, such as to induce a chemical reaction, and combinations thereof).

[0096] In the case of drying a substrate in processing module 1200, a controlled environment can provide continuous removal of evaporated vapors by vapor traps or a gas recirculation and purification system, and the drying process can be further controlled through the controlled application of gas flow across the substrate surface, such as a laminar flow that can be provided to flow across the face of the substrate, as shown in FIG. 13B.

[0097] (Example) (Various notes and examples) Example 1 may include or use subject matter (such as an apparatus, method, means for performing an action, or a device readable medium including instructions that, when performed by a device, can cause the device to perform the action) that may include a method of providing a coating on a substrate, the method including: transferring a substrate to a coating system configured to provide a solid layer in a specific region on a first side of the substrate, the solid layer covering at least a portion of the substrate; supporting the substrate in the coating system using a gas cushion provided on a second side of the substrate opposite the specific region; while the substrate is supported by the gas cushion, printing a liquid coating over the specific region of the substrate using a printing system with the substrate located in a printing zone; transporting the substrate to a treatment zone while continuing to support the substrate using the gas cushion; and treating the liquid coating in the coating system to provide a solid layer on the substrate in the specific region while continuing to support the substrate using the gas cushion.

[0098] Example 2 can optionally include or can be optionally combined with the subject matter of Example 1, including that the solid layer comprises at least a portion of an encapsulation structure, the substrate comprises an electronic device, and the encapsulation structure is established on the substrate to encapsulate at least a portion of the electronic device.

[0099] Example 3 can optionally include or be combined with the subject matter of one or any combination of Examples 1 or 2, such as optionally including treating the liquid coating includes polymerizing the liquid coating.

[0100] Example 4 can optionally include or be combined with the subject matter of one or any combination of Examples 1 to 3, to optionally include holding the substrate for a particular duration after printing the liquid coating while continuing to support the substrate using a gas cushion.

[0101] Example 5 can include, or can be optionally combined with, the subject matter of Example 4 to optionally include conveying the substrate to a holding zone for holding the substrate for a particular duration.

[0102] Example 6 can optionally include or can be optionally combined with the subject matter of Example 5 to include using a retention zone configured to hold and support multiple substrates using a gas cushion.

[0103] Example 7 can optionally include or be combined with the subject matter of one or any combination of Examples 1 to 6, such as optionally including treating the liquid coating includes irradiating the liquid coating with light.

[0104] Example 8 can optionally include, or can be optionally combined with, the subject matter of Example 7, such as optionally including that the light includes ultraviolet (UV) light.

[0105] Example 9 can optionally include, or can be optionally combined with, the subject matter of Example 7, such that irradiating the liquid coating with light includes baking the liquid coating with radiation.

[0106] Example 10 can optionally include, or can be optionally combined with, the subject matter of Example 7, such that irradiating the liquid coating with light includes drying the liquid coating with radiation.

[0107] Example 11 can optionally include or be combined with the subject matter of one or any combination of Examples 1 to 10, such that optionally treating the liquid coating includes one or more of exposing the substrate to infrared radiation or exposing to a temperature-controlled gas flow.

[0108] Example 12 can include or can be optionally combined with the subject matter of one or any combination of Examples 1 to 11, optionally including that a particular area on a first side of the substrate overlaps with an active area of ​​the substrate carrying the electronic device, and a gas cushion is provided on a second side of the substrate opposite the active area.

[0109] Example 13 can optionally include or be combined with the subject matter of one or any combination of Examples 1 to 12, such that optionally, transporting the substrate includes engaging or gripping the substrate using physical contact with the substrate.

[0110] Example 14 can include or can be optionally combined with the subject matter of one or any combination of Examples 1 to 13, optionally including that a gas cushion is established by forcing a gas through the porous ceramic material to support the second side of the substrate above the porous ceramic material.

[0111] Example 15 can optionally include or be combined with the subject matter of one or any combination of Examples 1 to 14, to optionally include that the gas cushion in the print zone is established using a combination of a pressurized gas region and at least a partial vacuum.

[0112] Example 16 can optionally include or can be optionally combined with the subject matter of Example 15, to include that at least one of the pressurized gas or the exhaust gas used to establish the gas cushion is recovered and recirculated.

[0113] Example 17 may include or optionally be combined with the subject matter of one or any combination of Examples 1 to 16, such as including subject matter (such as an apparatus, method, means for performing an action, or a machine-readable medium including instructions that, when performed by a machine, can cause the machine to perform an action), which may include a method of providing a coating on a substrate, the method including: transferring a substrate to an enclosed coating system, the enclosed coating system configured to provide a solid layer in a specific region on a first side of the substrate, the solid layer covering at least a portion of an electronic device being fabricated on the substrate; supporting the substrate in the enclosed coating system using a gas cushion provided on a second side of the substrate opposite the specific region; printing a liquid coating over the specific region of the substrate with the substrate positioned in a print zone including a printing system while the substrate is supported by the gas cushion; transporting the substrate to a treatment zone while continuing to support the substrate using the gas cushion; and treating the liquid coating in the treatment zone to provide a solid layer on the substrate in the specific region while continuing to support the substrate using the gas cushion.

[0114] Example 18 can optionally include, or can be optionally combined with, the subject matter of Example 17, such that treating the liquid coating includes one or more of baking or drying the liquid coating to provide a solid layer.

[0115] Example 19 can optionally include, or can be optionally combined with, the subject matter of Example 18 such that treating the liquid coating includes one or more of exposing the substrate to infrared radiation or exposing to a temperature-controlled gas flow.

[0116] Example 20 can optionally include, or can be optionally combined with, the subject matter of one or any combination of Examples 17 to 19, such that treating the liquid coating includes solidifying the liquid coating through one or more of inducing a chemical reaction or removing a carrier fluid included in the liquid coating.

[0117] Example 21 can optionally include or be combined with the subject matter of one or any combination of Examples 17 to 20, such that the solid layer comprises at least a portion of an encapsulation structure established on the substrate to encapsulate at least a portion of the electronic device.

[0118] Example 22 can optionally include or be combined with the subject matter of one or any combination of Examples 17 to 21, to include transporting the substrate to a holding zone and holding the substrate for a specific duration while continuing to support the substrate using a gas cushion.

[0119] Example 23 may include or optionally be combined with the subject matter of one or any combination of Examples 1 to 22, such as including subject matter (such as an apparatus, method, means for performing an action, or a machine-readable medium including instructions that, when performed by a machine, can cause the machine to perform an action), which may include a coating system for providing a solid layer on a substrate, the system comprising: a platform configured to support the substrate using a gas cushion and configured to transport the substrate along the platform; a printing system configured to deposit a liquid coating in a specific area on a first side of the substrate while the substrate is supported by the gas cushion on a second side of the substrate opposite the first side of the substrate when the substrate is located in a print zone of the platform; and a treatment system configured to provide a solid layer on the substrate in the specific area by treating the deposited liquid while the substrate is supported by the gas cushion when the substrate is located in a treatment zone of the platform, the platform configured to continuously support the substrate during printing operations in the print zone and treatment operations in the treatment zone.

[0120] Example 24 can optionally include or can be optionally combined with the subject matter of Example 23, including that the solid layer comprises at least a portion of an encapsulation structure, the substrate comprises an electronic device, and the encapsulation structure is established on the substrate to encapsulate at least a portion of the electronic device.

[0121] Example 25 can optionally include, or can be optionally combined with, the subject matter of one or any combination of Examples 23 or 24, such that the treatment system includes a light source, the source being configured to irradiate the liquid coating to provide a solid layer.

[0122] Example 26 can optionally include or can be optionally combined with the subject matter of Example 25, including that the source comprises an ultraviolet (UV) source.

[0123] Example 27 can optionally include or can be optionally combined with the subject matter of Example 25, such as optionally including that the source comprises an infrared source.

[0124] Example 28 can optionally include or be combined with the subject matter of one or any combination of Examples 23 to 25, such that the treatment system is configured to one or more of baking or drying the liquid coating to provide a solid layer.

[0125] Example 29 can include, or can be optionally combined with, the subject matter of one or any combination of Examples 23 to 28, optionally including that the treatment system is configured to solidify the liquid coating through one or more of inducing a chemical reaction or removing a carrier fluid contained in the liquid coating.

[0126] Example 30 can optionally include or be combined with the subject matter of one or any combination of Examples 23 to 29, such that the platform includes continuing to support the substrate using a gas cushion and is configured to hold the substrate for a particular duration after the printing operation and before the treatment operation.

[0127] Example 31 can optionally include, or can be optionally combined with, the subject matter of Example 30, such that the platform includes a holding zone separate from the print zone and treatment zone, the holding zone including continuing to support the substrate using a gas cushion, and configured to hold the substrate for a specified duration.

[0128] Example 32 can include, or can be optionally combined with, the subject matter of one or any combination of Examples 23 to 30, optionally including an enclosure housing the printing system, treatment system, and platform, including a controlled processing environment at or near atmospheric pressure, established to remain below specified limits for particulate matter contamination levels, water vapor content, oxygen content, and ozone content.

[0129] Example 33 can include, or can be optionally combined with, the subject matter of one or any combination of Examples 23 to 32, optionally including that a particular region on a first side of the substrate overlaps with an active area of ​​the substrate having an electronic device, and the platform is configured to provide gas to a second side of the substrate opposite the active area.

[0130] Example 34 optionally includes the platform being configured to transport the substrate using physical contact with the substrate, including engaging or gripping the substrate. may include or optionally be combined with the subject matter of one or any combination of Examples 23 to 33.

[0131] Example 35 can optionally include, or can be optionally combined with, the subject matter of one or any combination of Examples 23 to 34, optionally including wherein a gas cushion is established by forcing a gas through the porous ceramic material to support the second side of the substrate above the porous ceramic material.

[0132] Each of the non-limiting embodiments described herein can stand alone or can be combined in various permutations or combinations with one or more of the other embodiments.

[0133] The above detailed description includes reference to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are also referred to herein as "examples." Such examples may include elements in addition to those shown or described. However, the inventors also contemplate examples in which only those elements shown or described are provided. The inventors also contemplate examples that use any combination or permutation of these elements (or one or more aspects thereof) shown or described, either with respect to a particular example (or one or more aspects thereof) or with respect to other examples (or one or more aspects thereof) shown or described herein. In the event of inconsistent usage between this document and any document so incorporated by reference, the usage in this document shall control.

[0134] The terms "a" or "an" are used herein as is common in patent documents to include one or more than one, independent of any other instance or usage of "at least one" or "one or more." The term "or" is used herein to refer to a non-exclusive "or," such that "A or B" includes "A but not B," "B but not A," and "A and B," unless otherwise indicated. The terms "including" and "in which" are used herein as the plain English equivalents of the respective terms "comprising" and "wherein." Also, in the following claims, the terms "including" and "comprising" are open-ended, i.e., a system, device, component, composition, formulation, or process that includes elements in addition to those recited after such terms in a claim will still be considered to be within the scope of that claim. Moreover, in the following claims, the terms "first," "second," "third," etc. are used merely as labels and are not intended to impose numerical requirements on their objects.

[0135] The method embodiments described herein may be at least partially machine or computer implemented. Some embodiments may include a computer readable medium or machine readable media encoded with instructions operable to configure an electronic device to perform the method as described in the above embodiments. Such method implementations may include code, such as microcode, assembly language code, higher order language code, etc. Such code may include computer readable instructions for performing various methods. The code may form part of a computer program product. Further, in embodiments, the code may be tangibly stored on one or more of volatile, non-transitory, or non-volatile tangible computer readable media, such as during execution or at other times. Examples of these tangible computer readable media may include, but are not limited to, hard disks, removable magnetic disks, removable optical disks (e.g., compact disks and digital video disks), magnetic cassettes, memory cards or sticks, random access memory (RAM), read only memory (ROM), etc.

[0136] The above description is intended to be illustrative, not restrictive. For example, the above examples (or one or more aspects thereof) may be used in combination with each other. Other embodiments may be used, such as by one of ordinary skill in the art upon reviewing the above description. The Abstract is provided to comply with 37 CFR §1.72(b) to enable the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Also, in the above Detailed Description, various features may be grouped together to streamline the disclosure. This should not be construed as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter may lie in less than all features of a particular disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description as an example or embodiment, with each claim standing on its own as a separate example, and it is contemplated that such embodiments can be combined with each other in various combinations or permutations. The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims

1. 1. A coating system, comprising: An enclosure; a print zone within the enclosure, the print zone comprising an inkjet system; a treatment zone within the enclosure, the treatment zone comprising a treatment system; and a rotatable platform within the enclosure for transporting a substrate from the print zone to the treatment zone; A coating system comprising: a movable substrate handler for placing a substrate in the print zone and removing the substrate from the print zone.

2. The coating system of claim 1 , wherein the rotatable platform comprises a gas cushion substrate support.

3. The coating system of claim 1 , further comprising a treatment zone within the enclosure, the rotatable platform transporting the substrate between the print zone, the treatment zone, and the treatment zone.

4. The coating system of claim 1 , wherein the print zone comprises a gas cushion substrate support.

5. The coating system of claim 1 , further comprising an input module, the substrate handler being movable to remove the substrate from the input module.

6. The coating system of claim 1 , wherein the print zone comprises a gripper for holding the substrate during printing.

7. The coating system of claim 6 , wherein the substrate handler is located outside the enclosure.

8. 10. The coating system of claim 1, wherein at least one of the print zone, the treatment zone, and the rotatable platform has a gas cushion support for supporting the substrate as it is transported from the print zone to the treatment zone.

9. 5. The coating system of claim 4, wherein the gas cushion substrate support in the print zone provides a combination of pressurized gas and vacuum to control the levitation of the substrate.

10. 1. A coating system, comprising: An enclosure; a print zone within the enclosure, the print zone comprising an ink jet system having a gas cushion substrate support; a treatment zone within the enclosure, the treatment zone comprising a treatment system having a gas cushion substrate support; a rotatable platform within the enclosure for transporting a substrate from the print zone to the treatment zone; A coating system comprising: a movable substrate handler for placing a substrate in the print zone and removing a substrate from the print zone.

11. The coating system of claim 10 , wherein the rotatable platform comprises a gas cushion substrate support.

12. 11. The coating system of claim 10, wherein the gas cushion substrate support in each of the print zone, the treatment zone, or both, is provided with a temperature controlled gas flow.

13. The coating system of claim 10 , wherein the substrate handler is disposed outside the enclosure.

14. The coating system of claim 10, further comprising a treatment zone within the enclosure, the rotatable platform transporting the substrate between the print zone, the treatment zone, and the treatment zone.

15. 15. The coating system of claim 14, wherein the gas cushion substrate support in the print zone provides a combination of pressurized gas and vacuum to control substrate levitation.

16. the enclosure is a first enclosure, the print zone is a first print zone, the treatment zone is a first treatment zone, the rotatable platform is a first rotatable platform, the enclosure, the print zone, the treatment zone, and the rotatable platform are part of a first coating unit, and further 11. The coating system of claim 10, comprising a second coating unit having a second enclosure, a second print zone within the second enclosure, a second treatment zone within the second enclosure, and a second rotatable platform within the second enclosure, wherein the substrate handler is movable to place a substrate in the second print zone and to remove the substrate from the second print zone.

17. 1. A coating system, comprising: A coating unit; An enclosure; a print zone within the enclosure, the print zone comprising an inkjet system having a gas cushion substrate support and a substrate gripper; a treatment zone within the enclosure, the treatment zone comprising a treatment system having a gas cushion substrate support and an ultraviolet light source; a rotatable platform within the enclosure for transporting a substrate from the print zone to the treatment zone; A coating system comprising: a movable substrate handler for placing a substrate in the print zone and removing the substrate from the print zone.

18. 20. The coating system of claim 17, further comprising an input module, the substrate handler being movable to remove a substrate from the input module.

19. The coating system of claim 17 , wherein the substrate handler is housed in a transfer module located outside the enclosure.

20. 20. The coating system of claim 17, wherein the coating unit further comprises a treatment zone within the enclosure, and the rotatable platform transports the substrate between the print zone, the treatment zone, and the treatment zone.

Images