Low-particle gas enclosure system and method

Abstract

To provide suitable low-particle gas enclosure systems and methods.SOLUTION: The present teachings relate to various embodiments of a gas enclosure system that can have various components comprising a particle control system that can provide a low-particle zone proximal to a substrate. Various components of a particle control system can include a gas circulation and filtration system, a low-particle-generating motion system for moving a print head assembly relative to a substrate, a service bundle housing exhaust system, and a print head assembly exhaust system. In addition to maintaining substantially low levels for each species of various reactive species, including various reactive atmospheric gases, such as water vapor and oxygen, for various embodiments of the gas enclosure system that have a particle control system, an on-substrate particle specification can be readily met. Accordingly, processing of various substrates in an inert, low-particle gas environment according to systems and methods of the present teachings can have substantially lower manufacturing defects.SELECTED DRAWING: Figure 26

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of U.S. Provisional Application No. 61 / 833,398, filed June 10, 2013. This application claims the benefit of U.S. Provisional Application No. 61 / 911,934, filed December 4, 2013. This application claims the benefit of U.S. Provisional Application No. 61 / 925,578, filed January 9, 2014. This application claims the benefit of U.S. Provisional Application No. 61 / 983,417, filed April 23, 2014. This application is a continuation-in-part of U.S. Application No. 14 / 205,340, filed March 11, 2014. U.S. Application No. 14 / 205,340, filed March 11, 2014, is a continuation-in-part of U.S. Application No. 13 / 802,304, filed March 13, 2013 (published August 15, 2013 as US2013 / 0206058). U.S. Application No. 13 / 802,304 is a continuation-in-part of U.S. Application No. 13 / 720,830, filed December 19, 2012 (published September 26, 2013 as US2013 / 0252533). U.S. Application No. 13 / 720,830 claims the benefit of U.S. Provisional Application No. 61 / 579,233, filed December 22, 2011. U.S. Application No. 13 / 720,830, filed December 19, 2012, is a continuation-in-part of U.S. Application No. 12 / 652,040, filed January 5, 2010 (registered February 26, 2013 as US8,383,202). U.S. Application No. 12 / 652,040 is a continuation-in-part of U.S. Application No. 12 / 139,391, filed June 13, 2008 (published December 18, 2008 as US2008 / 0311307). U.S. Application No. 12 / 652,040 also claims the benefit of U.S. Provisional Application No. 61 / 142,575, filed January 5, 2009. All cross-referenced applications listed herein are incorporated by reference in their entirety. [Background technology]

[0002] (Field) The present teachings relate to various embodiments of a gas enclosure system having an inert, substantially low-particle environment for the fabrication of OLED panels on a variety of substrate sizes and substrate materials.

[0003] (overview) Interest in the potential of organic light-emitting diode (OLED) display technology has been driven by OLED display technology attributes, including the demonstration of display panels with highly saturated colors, high contrast, ultrathinness, fast response, and energy efficiency. In addition, a variety of substrate materials, including flexible polymeric materials, can be used in the fabrication of OLED display technology. Demonstrations of displays for small screen applications, primarily mobile phones, have served to highlight the potential of the technology, but challenges remain in scaling up mass production across a range of substrate formats with high yields.

[0004] With regard to format scaling, Gen 5.5 substrates have dimensions of approximately 130 cm x 150 cm and can yield approximately eight 26-inch flat panel displays. By comparison, larger format substrates include using Gen 7.5 and Gen 8.5 mother glass substrate sizes. Gen 7.5 mother glass has dimensions of approximately 195 cm x 225 cm and can be cut into eight 42-inch or six 47-inch flat panel displays per substrate. Mother glass used in Gen 8.5 is approximately 220 cm x 250 cm and can be cut into six 55-inch or eight 46-inch flat panel displays per substrate. As one indication of the challenges remaining in scaling OLED display manufacturing to larger formats, mass production of OLED displays at high yields on substrates larger than Gen 5.5 substrates has proven to be substantially difficult.

[0005] In principle, OLED devices can be fabricated by printing various organic thin films and other materials onto a substrate using an OLED printing system. Such organic materials can be susceptible to damage from oxidation and other chemical processes. Housing an OLED printing system in a manner that can be scaled to accommodate various substrate sizes and performed within an inert, substantially low-particle printing environment can present various technical challenges. For example, manufacturing tools for high-throughput, large-format substrate printing, such as printing Gen 7.5 and Gen 8.5 substrates, require substantially large-scale equipment. Therefore, maintaining large-scale equipment under an inert atmosphere, which requires gas purification to remove reactive atmospheric species such as water vapor and oxygen, as well as organic solvent vapors, and maintaining a substantially low-particle printing environment present significant challenges. Summary of the Invention [Means for solving the problem]

[0006] Thus, challenges remain in scaling up mass production of OLED display technology across a range of substrate formats with high yields. Thus, for various embodiments, a need exists for a gas enclosure system of the present teachings that can house an OLED printing system in an inert, substantially low-particle environment and can be easily scaled to provide for the fabrication of OLED panels on a variety of substrate sizes and substrate materials. Additionally, the various gas enclosure systems of the present teachings can provide immediate access to the OLED printing system from the outside during processing and to the inside for maintenance with minimal downtime. The present specification also provides, for example, the following items: (Item 1) 1. A gas enclosure system comprising: a gas enclosure assembly defining an interior for containing a gas; a commercial printing system housed within the gas enclosure assembly, the commercial printing system comprising: a printhead assembly including at least one printhead; a substrate support device; a service bundle enclosure for housing a service bundle, the service bundle being operably connected to the printing system; a commercial printing system comprising: a service bundle enclosure exhaust system for exhausting gases proximate the service bundle enclosure away from the substrate support apparatus; A gas enclosure system comprising: (Item 2) The gas enclosure assembly further comprises: a printing system enclosure for housing the printing system; an auxiliary enclosure configured to be sealably isolated from the printing system; and Item 1. The gas enclosure system of item 1, comprising: (Item 3) Item 10. The gas enclosure system of item 1, wherein the gas is an inert gas. (Item 4) 4. The gas enclosure system of claim 3, wherein the inert gas is selected from nitrogen, any of the noble gases, and combinations thereof. (Item 5) Item 2. The gas enclosure system of item 1, wherein the gas is clean dry air (CDA). (Item 6) 2. The gas enclosure system of claim 1, further comprising a gas purification system. (Item 7) 7. The gas enclosure system of claim 6, wherein the gas purification system maintains the gas at less than 100 ppm of each of the reactive species. (Item 8) 8. The gas enclosure system of claim 7, wherein the reactive species is selected from water vapor and oxygen. (Item 9) 1. A gas enclosure system comprising: a gas enclosure assembly defining an interior for containing a gas; a commercial printing system housed within the gas enclosure assembly, the commercial printing system comprising: a printhead assembly including at least one printhead; a substrate support device; a motion system for precisely positioning the printhead assembly relative to a substrate supported on the substrate support apparatus; and a service bundle enclosure for housing a service bundle, the service bundle being operably connected to the printing system; a commercial printing system comprising: a service bundle enclosure exhaust system for exhausting gases proximate the service bundle enclosure away from the substrate; Equipped with A gas enclosure system wherein a low particle environment is maintained within said gas enclosure system that provides an average on-substrate particle distribution that meets an on-substrate deposition rate specification of less than or equal to about 100 particles per square meter of substrate per minute for particles greater than or equal to 2 μm in size. (Item 10) 10. The gas enclosure system of claim 9, wherein the average on-substrate particle distribution meets an on-substrate deposition rate specification of less than or equal to about 1000 particles per square meter of substrate per minute for particles greater than or equal to 0.3 μm in size. (Item 11) 10. The gas enclosure system of claim 1 or 9, wherein the service bundle housing exhaust system is in fluid communication with a gas circulation and filtration system. (Item 12) 10. The gas enclosure system of claim 1 or claim 9, further comprising a printhead assembly exhaust system for exhausting gas proximate the printhead assembly away from the substrate support apparatus. (Item 13) Item 13. The gas enclosure system of item 12, wherein the printhead assembly exhaust system is in fluid communication with a gas circulation and filtration system. (Item 14) 10. The gas enclosure system of claim 1 or 9, wherein the motion system is a split-axis motion system. (Item 15) Item 15. The gas enclosure system of item 14, wherein the split axis motion system comprises an air bearing motion system. (Item 16) 10. The gas enclosure system of claim 1 or 9, wherein the substrate support device comprises a floating table. (Item 17) 10. The gas enclosure system of claim 1 or 9, wherein the motion system for moving the substrate through the printing system is an air bearing motion system. (Item 18) 10. The gas enclosure system of claim 1, wherein the substrate support device is capable of supporting substrates ranging in size from about 3.5 generations to about 10 generations. (Item 19) Item 19. The gas enclosure system of item 18, wherein the gas is an inert gas. (Item 20) 20. The gas enclosure system of item 19, further comprising a gas purification system. (Item 21) 21. The gas enclosure system of claim 20, wherein the gas purification system maintains the gas at less than 100 ppm of each of the reactive species.

[0007] A better understanding of the features and advantages of the present disclosure may be obtained by reference to the accompanying drawings, which are intended to illustrate, but not to limit, the present teachings. [Brief explanation of the drawings]

[0008] [Figure 1A] FIG. 1 is a right-front perspective view of a gas enclosure assembly according to various embodiments of the present teachings. [Figure 1B] FIG. 1 is a right-front perspective view of a gas enclosure assembly according to various embodiments of the present teachings. [Figure 2] FIG. 2 depicts an exploded view of a gas enclosure assembly according to various embodiments of the present teachings. [Figure 3] FIG. 3 is an exploded front perspective view of a frame member assembly depicting various panel frame sections and section panels according to various embodiments of the present teachings. [Figure 4A] 4A, 4B, and 4C are top schematic views of various embodiments of gasket seals for forming joints. [Figure 4B] 4A, 4B, and 4C are top schematic views of various embodiments of gasket seals for forming joints. [Figure 4C] 4A, 4B, and 4C are top schematic views of various embodiments of gasket seals for forming joints. [Figure 5A] 5A and 5B are various perspective views depicting sealing of frame members according to various embodiments of a gas enclosure assembly of the present teachings. [Figure 5B] 5A and 5B are various perspective views depicting sealing of frame members according to various embodiments of a gas enclosure assembly of the present teachings. [Figure 6A] 6A and 6B are various views of sealing a section panel to receive an easily removable access glass according to various embodiments of a gas enclosure assembly of the present teachings. [Figure 6B] 6A and 6B are various views of sealing a section panel to receive an easily removable access glass according to various embodiments of a gas enclosure assembly of the present teachings. [Figure 7A] 7A and 7B are enlarged perspective cross-sectional views of a section panel seal for receiving an inset panel or window panel according to various embodiments of the present teachings. [Figure 7B]7A and 7B are enlarged perspective cross-sectional views of a section panel seal for receiving an inset panel or window panel according to various embodiments of the present teachings.

[0009] [Figure 8] FIG. 8 is a diagram of a ceiling including a lighting system for various embodiments of a gas enclosure system according to the present teachings. [Figure 9] FIG. 9 is a front perspective view of a gas enclosure assembly according to various embodiments of the present teachings. [Figure 10A] FIG. 10A depicts an exploded view of various embodiments of a gas enclosure assembly and associated printing as depicted in FIG. 9 according to various embodiments of the present teachings. [Figure 10B] FIG. 10B depicts an enlarged isometric perspective view of the printing system depicted in FIG. 10A. [Figure 10C] FIG. 10C shows an enlarged isometric perspective view of the auxiliary enclosure depicted in FIG. 10A. [Figure 11] FIG. 11 depicts a perspective view of a floating table according to various embodiments of the present teachings.

[0010] [Figure 12] FIG. 12 is a schematic diagram of various embodiments of a gas enclosure assembly and related system components of the present teachings. [Figure 13] FIG. 13 is a schematic diagram of various embodiments of a gas enclosure assembly and related system components of the present teachings. [Figure 14] FIG. 14 is a schematic diagram of a gas enclosure system according to various embodiments of the present teachings. [Figure 15] FIG. 15 is a schematic diagram of a gas enclosure system according to various embodiments of the present teachings. [Figure 16] FIG. 16 is a transparent front perspective view of a gas enclosure assembly depicting piping installed inside the gas enclosure assembly in accordance with various embodiments of the present teachings. [Figure 17]FIG. 17 is a transparent top perspective view of a gas enclosure assembly depicting piping installed inside the gas enclosure assembly in accordance with various embodiments of the present teachings. [Figure 18] FIG. 18 is a see-through bottom perspective view of a gas enclosure assembly depicting piping installed inside the gas enclosure assembly in accordance with various embodiments of the present teachings. [Figure 19A] 19A and 19B are schematic diagrams showing a service bundle and a gas passing through the service bundle, respectively, routed through various embodiments of piping according to the present teachings. [Figure 19B] 19A and 19B are schematic diagrams showing a service bundle and a gas passing through the service bundle, respectively, routed through various embodiments of piping according to the present teachings. [Figure 20] FIG. 20 is a schematic diagram showing how reactive species (A) trapped in the dead space of a service bundle are actively purged from inert gas (B) passing through the duct through which the bundle is routed. [Figure 21A] FIG. 21A is a transparent perspective view of cables and tubing routed through a pipe according to various embodiments of a gas enclosure system of the present teachings. [Figure 21B] FIG. 21B is an enlarged view of the opening shown in FIG. 21A showing details of a cover for closure over the opening according to various embodiments of a gas enclosure system of the present teachings. [Figure 22] FIG. 22 is a schematic cross-sectional side view of a gas enclosure system depicting an embodiment of gas circulation through a gas enclosure assembly in accordance with various embodiments of the present teachings. [Figure 23] FIG. 23 is a schematic cross-sectional side view of a gas enclosure system depicting an embodiment of gas circulation through a gas enclosure assembly in accordance with various embodiments of the present teachings. [Figure 24]FIG. 24 is a schematic cross-sectional front view of a gas enclosure depicting an embodiment of gas circulation through the gas enclosure assembly in accordance with various embodiments of the present teachings. [Figure 25] FIG. 25 is a cross-sectional schematic view of a gas enclosure assembly with system components according to various embodiments of the present teachings. [Figure 26] FIG. 26 is a perspective view of a printing system depicting various embodiments of a particle control system of the present teachings, which can include a low particle X-axis motion system and a service bundle housing exhaust system. [Figure 27A] 27A and 27B are cross-sectional views of a low particle X-axis motion system according to various embodiments of the present teachings. [Figure 27B] 27A and 27B are cross-sectional views of a low particle X-axis motion system according to various embodiments of the present teachings. [Figure 28A] 28A and 28B are various perspective views of a service stack housing ejection system for a printing system according to various embodiments of the present teachings. [Figure 28B] 28A and 28B are various perspective views of a service stack housing ejection system for a printing system according to various embodiments of the present teachings. [Figure 29A] FIG. 29A is a schematic diagram of a service bundle housing discharge system according to various embodiments of the present teachings. [Figure 29B] 29B, 29C, and 29D are schematic illustrations of various embodiments of venting a service bundle housing according to various embodiments of the present teachings. [Figure 29C] 29B, 29C, and 29D are schematic illustrations of various embodiments of venting a service bundle housing according to various embodiments of the present teachings. [Figure 29D] 29B, 29C, and 29D are schematic illustrations of various embodiments of venting a service bundle housing according to various embodiments of the present teachings. [Figure 30A]30A and 30B are schematic diagrams of a gas enclosure system depicting an embodiment of gas circulation and particle collection around a printhead assembly within the gas enclosure assembly in accordance with various embodiments of the present teachings. [Figure 30B] 30A and 30B are schematic diagrams of a gas enclosure system depicting an embodiment of gas circulation and particle collection around a printhead assembly within the gas enclosure assembly in accordance with various embodiments of the present teachings. [Figure 31A] 31A and 31B are schematic diagrams of a gas enclosure system depicting an embodiment of gas circulation and particle collection around a printhead assembly within the gas enclosure assembly in accordance with various embodiments of the present teachings. [Figure 31B] 31A and 31B are schematic diagrams of a gas enclosure system depicting an embodiment of gas circulation and particle collection around a printhead assembly within the gas enclosure assembly in accordance with various embodiments of the present teachings. [Figure 32A] 32A and 32B are schematic diagrams of a gas enclosure system depicting an embodiment of gas circulation and particle collection around a printhead assembly within the gas enclosure assembly in accordance with various embodiments of the present teachings. [Figure 32B] 32A and 32B are schematic diagrams of a gas enclosure system depicting an embodiment of gas circulation and particle collection around a printhead assembly within the gas enclosure assembly in accordance with various embodiments of the present teachings. [Figure 33] FIG. 33 is an embodiment of a portable airborne particle counting device in accordance with the present teachings. [Figure 34] FIG. 34 is a schematic illustration of the principle of operation of various portable airborne particle counting devices based on the scattering of electromagnetic radiation. [Figure 35] FIG. 35 is a schematic diagram depicting various areas where a portable airborne particle counting device can be located in various printing systems of the present teachings. [Figure 36]FIG. 36 is an isometric perspective view of a portable airborne particle counting device positioned proximal to a substrate support apparatus in accordance with various embodiments of the present teachings. [Figure 37A] 37A and 37B are graphs depicting long-term testing results of particle counts in various embodiments of gas enclosure systems of the present teachings. [Figure 37B] 37A and 37B are graphs depicting long-term testing results of particle counts in various embodiments of gas enclosure systems of the present teachings. [Figure 38] FIG. 38 is a graph depicting particle count collection test results before and after opening the gas enclosure system window. [Figure 39] FIG. 39 is a schematic illustration of the principle of operation of various particle detection devices for on-substrate particle detection based on scattering of electromagnetic radiation. [Figure 40] FIG. 40 is an isometric perspective view of an arrangement of a test substrate proximate a print area according to various embodiments of the present teachings. [Figure 41] FIG. 41 is an isometric perspective view of a substrate placement proximate a print zone in a printing system equipped with a camera, in accordance with various embodiments of the present teachings. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present teachings disclose various embodiments of a gas enclosure assembly capable of housing an OLED printing system. The various embodiments of the gas enclosure assembly can be hermetically constructed and integrated with various components that provide particle control systems, gas circulation and filtration systems, gas purification systems, and the like to form various embodiments of gas enclosure systems capable of sustaining a substantially low-particle, inert gas environment for processes requiring such an environment.

[0012] In principle, a manufacturing tool capable of printing various substrate sizes, including large-format substrate sizes, may require a substantially large facility to accommodate such an OLED manufacturing tool. Therefore, maintaining an entire large facility under an inert atmosphere presents technical challenges, such as continuous purification of large quantities of inert gas. According to the present teachings, an inert gas may be any gas that does not undergo chemical reactions under a defined set of conditions. Some commonly used, non-limiting examples of inert gases include nitrogen, any of the noble gases, and any combination thereof. Additionally, providing a large facility that is essentially sealed to prevent contamination from various reactive atmospheric gases, such as water vapor and oxygen, and organic solvent vapors generated from various printing processes presents technical challenges. According to the present teachings, an OLED printing facility may maintain various levels of various reactive species, including various reactive atmospheric gases, such as water vapor and oxygen, and organic solvent vapors, at or below 100 ppm, e.g., 10 ppm or below, 1.0 ppm or below, or 0.1 ppm or below.

[0013] The continuous maintenance of large facilities requiring an inert environment presents additional challenges. For example, a manufacturing facility may require significant lengths of various service bundles that can be operably connected from various systems and assemblies to provide, for example, but not limited to, optical, electrical, mechanical, and fluid connections required to operate a printing system. According to the present teachings, service bundles can include, by way of non-limiting example, optical cables, electrical cables, wires and tubing, and the like. Various embodiments of service bundles according to the present teachings may have significant total dead volume as a result of the significant number of gaps created by bundling the various cables, wires and tubing, and the like, together in the service bundle. The total dead volume due to the significant number of gaps in the service bundle can result in the retention of significant amounts of trapped reactive gas species therein. Such significant amounts of trapped reactive gas species can present challenges for effectively bringing a gas enclosure to specifications for levels of reactive atmospheric components, such as oxygen and water vapor, and organic vapors. Additionally, such service bundles used in the operation of a printing system may be a continuous source of particulate matter.

[0014] In that regard, providing and maintaining a substantially inert, low-particle environment in an OLED manufacturing facility presents additional challenges not presented for processes that can be performed at atmospheric conditions, for example, under an open, high-flow, laminar-flow, filtered hood. Accordingly, various embodiments of the systems and methods of the present teachings address the challenges presented in OLED printing of OLED substrates of various sizes and materials in an inert, substantially low-particle environment.

[0015] With regard to maintaining a substantially low-particle environment, various embodiments of the gas circulation and filtration system can be designed to provide a low-particle inert gas environment for airborne particulate matter that meets the standards of International Standards Organization Standard (ISO) 14644-1:1999, "Cleanrooms and associated controlled environments—Part 1: Classification of air cleanliness," as specified by Class 1 through Class 5. However, controlling airborne particulate matter alone is not sufficient to provide a low-particle environment proximate to the substrate during, for example, but not limited to, a printing process, because particles generated proximate to the substrate during such a process may accumulate on the substrate surface before being able to pass through the gas circulation and filtration system.

[0016] Thus, various embodiments of the gas enclosure system of the present teachings can have a particle control system, in addition to a gas circulation and filtration system, which can include components that can provide a low-particle zone proximate to the substrate during processing in a printing step. According to various embodiments of the gas enclosure system of the present teachings, the particle control system for various embodiments of the gas enclosure system of the present teachings can include a gas circulation and filtration system, a low-particle-generating X-axis linear bearing system for moving the print head assembly relative to the substrate, a service bundle housing exhaust system, and a print head assembly exhaust system. In that regard, in addition to a circulation and filtration system for maintaining a substantially low-particle specification for suspended particulate matter, various embodiments of the gas enclosure system of the present teachings can have a particle control system, which can include additional components for maintaining a substantially low-particle specification for particulate matter deposited on the substrate.

[0017] Various embodiments of the systems and methods of the present teachings can maintain a substantially low-particle environment that provides an average on-substrate distribution of particles of a particular size range of interest that does not exceed an on-substrate deposition rate specification. The on-substrate deposition rate specification can be set for each of the target particle size ranges from about 0.1 μm and larger to 10 μm and larger. In various embodiments of the systems and methods of the present teachings, the on-substrate particle deposition rate specification can be expressed as a limit on the number of particles deposited per square meter of substrate per minute for each of the larger particle size ranges.

[0018] Various embodiments of particle deposition rate specifications on substrates can be easily converted from a limit on the number of particles deposited per square meter of substrate per minute to a limit on the number of particles deposited per substrate per minute for each target particle size range. Such conversion can be easily performed, for example, through the known relationship between substrates of a particular generation size and the corresponding area of ​​that substrate generation. For example, Table 1 below summarizes the aspect ratios and areas of several known generation size substrates. It should be understood that slight variations in aspect ratios, and therefore sizes, may occur depending on the manufacturer. However, despite such variations, conversion factors for a particular generation size substrate and area in square meters can be obtained for any of the various generation size substrates. [Table 1]

[0019] Additionally, a particle deposition rate specification on a substrate, expressed as a limit on the number of particles deposited per square meter of substrate per minute, can be readily converted into any of a variety of unit time expressions. It will be readily understood that a particle deposition rate specification on a substrate normalized to a fraction can be readily converted into any other expression of time, such as, for example, but not limited to, seconds, hours, days, etc., through known time relationships. Additionally, process-specific units of time can be used. For example, a print cycle can be associated with a unit of time. For various embodiments of a gas enclosure system according to the present teachings, a print cycle can be the period during which a substrate is moved into the gas enclosure system for printing and then removed from the gas enclosure system after printing is completed. For various embodiments of a gas enclosure system according to the present teachings, a print cycle can be the period from the start of alignment of the substrate with the print head assembly to the delivery of the last ejected ink droplet onto the substrate. In the processing arts, a total average cycle time, or TACT, can be an expression of a unit of time for a particular process cycle. According to various embodiments of the systems and methods of the present teachings, the TACT for a print cycle can be approximately 30 seconds. For various embodiments of the systems and methods of the present teachings, the TACT for a print cycle can be approximately 60 seconds. For various embodiments of the systems and methods of the present teachings, the TACT for a print cycle can be approximately 90 seconds. For various embodiments of the systems and methods of the present teachings, the TACT for a print cycle can be approximately 120 seconds. For various embodiments of the systems and methods of the present teachings, the TACT for a print cycle can be approximately 300 seconds.

[0020] With regard to airborne particulate matter and particle deposition within a system, a significant number of variables can affect the development of a general model that can adequately calculate an approximation of the particle fallout rate value on a surface, such as a substrate, for any particular manufacturing system. Variables such as particle size, the distribution of particles of a particular size, the surface area of ​​the substrate, and the duration of exposure of the substrate within the system can vary for different manufacturing systems. For example, particle size and the distribution of particles of a particular size can be substantially affected by the source and location of particle-generating components within different manufacturing systems. Calculations based on various embodiments of the gas enclosure system of the present teachings suggest that, without the various particle control systems of the present teachings, particulate deposition on a substrate per printing cycle per square meter of substrate could be greater than about 1 million to about 10 million particles for particles in the 0.1 μm and larger size range. Such calculations suggest that, without the various particle control systems of the present teachings, the deposition of particulate matter on a substrate per print cycle per square meter of substrate could be greater than about 1000 to greater than about 10,000 particles for particles in the size range of about 2 μm and larger.

[0021] Various embodiments of the low-particle gas enclosure system of the present teachings can maintain a low-particle environment that provides an average on-substrate particle distribution that meets an on-substrate deposition rate specification of less than or equal to about 100 particles per square meter of substrate per minute for particles greater than or equal to 10 μm in size. Various embodiments of the low-particle gas enclosure system of the present teachings can maintain a low-particle environment that provides an average on-substrate particle distribution that meets an on-substrate deposition rate specification of less than or equal to about 100 particles per square meter of substrate per minute for particles greater than or equal to 5 μm in size. Various embodiments of the gas enclosure system of the present teachings can maintain a low-particle environment that provides an average on-substrate particle distribution that meets an on-substrate deposition rate of less than or equal to about 100 particles per square meter of substrate per minute for particles greater than or equal to 2 μm in size. Various embodiments of the gas enclosure system of the present teachings can maintain a low-particle environment that provides an average particle distribution on the substrate that meets a deposition rate on the substrate of less than about 100 particles per square meter of substrate per minute for particles greater than or equal to 1 μm in size. Various embodiments of the low-particle gas enclosure system of the present teachings can maintain a low-particle environment that provides an average particle distribution on the substrate that meets a deposition rate on the substrate of less than about 1000 particles per square meter of substrate per minute for particles greater than or equal to 0.5 μm in size. Various embodiments of the gas enclosure system of the present teachings can maintain a low-particle environment that provides an average particle distribution on the substrate that meets a deposition rate on the substrate of less than about 1000 particles per square meter of substrate per minute for particles greater than or equal to 0.3 μm in size. Various embodiments of the low-particle gas enclosure system of the present teachings can maintain a low-particle environment that provides an average on-substrate particle distribution that meets an on-substrate deposition rate of less than or equal to about 1000 particles per square meter of substrate per minute for particles greater than or equal to 0.1 μm in size.

[0022] As previously discussed herein, mass production of OLED displays with high yields on substrates larger than Gen 5.5 substrates has proven substantially difficult. To gain a clearer understanding of the substrate sizes that can be used in the production of various OLED devices, several generations of mother glass substrate sizes have evolved since the early 1990s for flat panel displays processed by methods other than OLED printing. The first generation of mother glass substrates, designated Gen 1, were approximately 30 cm × 40 cm and thus capable of producing 15-inch panels. Around the mid-1990s, existing technology for producing flat panel displays evolved to the Gen 3.5 mother glass substrate size, which had dimensions of approximately 60 cm × 72 cm. By comparison, Gen 5.5 substrates have dimensions of approximately 130 cm × 150 cm.

[0023] As generations progress, Gen 7.5 and Gen 8.5 mother glass sizes are being produced for purposes other than OLED printing. Gen 7.5 mother glass measures approximately 195 cm x 225 cm and can be cut into eight 42-inch or six 47-inch flat panels per substrate. Gen 8.5 mother glass measures approximately 220 cm x 250 cm and can be cut into six 55-inch or eight 46-inch flat panels per substrate. While OLED manufacturing has been practically limited to Gen 3.5 and smaller, the promise of OLED flat panel displays has been realized for qualities such as more true color, higher contrast, thinness, flexibility, transparency, and energy efficiency. OLED printing is now considered the manufacturing technology of choice, breaking through this limitation and enabling OLED panel manufacturing at the maximum mother glass sizes, including Gen 5.5, Gen 7.5, and Gen 8.5, as well as Gen 3.5 and smaller. Various substrate materials, including but not limited to various glass substrate materials and various polymer substrate materials, may be used, one of the features of OLED panel display technology. In that regard, the dimensions described using terms derived from the use of glass-based substrates may apply to substrates of any material suitable for use in OLED printing.

[0024] It is contemplated that a wide variety of ink formulations can be printed within the inert, substantially low-particle environment of various embodiments of the gas enclosure system of the present teachings. During the manufacture of OLED displays, OLED pixels can be formed to include an OLED film stack capable of emitting light of a specific peak wavelength when a voltage is applied. The OLED film stack structure between the anode and cathode can include a hole injection layer (HIL), a hole transport layer (HTL), an emissive layer (EL), an electron transport layer (ETL), and an electron injection layer (EIL). In some embodiments of the OLED film stack structure, the electron transport layer (ETL) can be combined with the electron injection layer (EIL) to form an ETL / EIL layer. According to the present teachings, inkjet printing can be used to print various ink formulations for the EL for the various color pixel EL films of the OLED film stack. Additionally, for example, but not limited to, the HIL, HTL, EML, and ETL / EIL layers can have ink formulations that can be printed using inkjet printing.

[0025] It is further contemplated that inkjet printing can be used to print the organic encapsulation layer onto the OLED panel. It is contemplated that inkjet printing can be used to print the organic encapsulation layer because inkjet printing can offer several advantages. First, such inkjet-based processing can be performed at atmospheric pressure, thereby eliminating a series of vacuum processing operations. Additionally, during the inkjet printing process, the organic encapsulation layer can be confined to cover portions of the OLED substrate over and proximal to the active area, effectively encapsulating the active area, including the outer edges of the active area. Targeted patterning using inkjet printing eliminates material waste and additional processing typically required to achieve patterning of the organic layer. The encapsulation ink can include polymers, including, but not limited to, acrylates, methacrylates, urethanes, or other materials, as well as copolymers and blends thereof that can be cured using thermal treatments (e.g., baking), ultraviolet radiation, and combinations thereof.

[0026] With respect to OLED printing, the present teachings have found that maintaining substantially low levels of reactive species, such as, but not limited to, atmospheric constituents such as oxygen and water vapor, as well as various organic solvent vapors used in OLED inks, correlates with providing OLED flat panel displays that meet required lifetime specifications. This is particularly important for OLED panel technology because the lifetime specification, a product specification for all panel technologies that OLED panel technology has difficulty meeting, directly correlates with the lifetime of the display product. To provide panels that meet required lifetime specifications, the respective levels of reactive species such as water vapor, oxygen, and organic solvent vapors can be maintained at 100 ppm or less, e.g., 10 ppm or less, 1.0 ppm or less, or 0.1 ppm or less, using various embodiments of the gas enclosure system of the present teachings.

[0027] The need to print OLED panels in equipment capable of maintaining levels of reactive species such as water vapor, oxygen, and organic solvent vapors at 100 ppm or less, e.g., 10 ppm or less, 1.0 ppm or less, or 0.1 ppm or less, can be illustrated by reviewing the information summarized in Table 2. The data summarized in Table 2 resulted from testing test coupons containing red, green, and blue organic thin film compositions fabricated in a large-pixel spin-coated device format. Such test coupons are substantially easier to manufacture and test for rapid evaluation of various formulations and processes. Test coupon testing should not be confused with lifetime testing of printed panels, but can demonstrate the impact of various formulations and processes on lifetime. The results shown in the table below represent variations in process steps in the processing of test coupons, where only the spin-coating environment was changed for test coupons processed in a nitrogen environment, which had less than 1 ppm of reactive species, compared to test coupons processed in air instead of a nitrogen environment.

[0028] Through examination of the data in Table 2 for test coupons processed under different processing environments, particularly in the case of red and blue, it is clear that printing in an environment that effectively reduces the exposure of organic thin film compositions to reactive species can have a significant impact on the stability and therefore lifetime of various EL devices. [Table 2]

[0029] Additionally, maintaining a substantially low-particle environment for OLED printing is particularly important because even very small particles can lead to visible defects on the OLED panel. In that regard, the systems and methods of the present teachings provide for maintaining low levels of reactive species such as water vapor, oxygen, and organic solvent vapors, as well as maintaining a sufficiently low-particle environment for high-quality OLED panel production. Various embodiments of the gas enclosure system can have a particle control system, in addition to the gas circulation and filtration system, which can include components to provide a low-particle zone proximate the substrate during processing in the printing step.

[0030] Various embodiments of the gas enclosure system of the present teachings can have a particle control system that provides a low-particle zone proximate the substrate that can contain and vent various particle-generating components proximate the substrate to prevent particles from accumulating on the substrate during the printing process. In various embodiments of the gas enclosure system, the particle control system can include a gas circulation and filtration system for maintaining airborne particulate matter levels that meet International Standards Organization Standard (ISO) 14644-1:1999, as specified by Class 1 through Class 5, both within the gas enclosure system and proximate the substrate. Various embodiments of the particle control system can include a gas circulation and filtration system in fluid communication with contained particle-generating components so that such particle-containing components can be vented into the gas circulation and filtration system. For various embodiments of the particle control system, the contained particle-generating components can be vented into a dead space, making such particulate matter inaccessible for recirculation within the gas enclosure system. Various embodiments of the gas enclosure system of the present teachings can have a particle control system in which various components can be inherently low particle generating, thereby preventing particles from accumulating on the substrate during the printing process. The various components of the particle control system of the present teachings can utilize the containment and evacuation of particle-generating components, as well as the selection of components that are inherently low particle generating, to provide a low particle zone proximate the substrate.

[0031] For various embodiments of the low-particle gas enclosure system of the present teachings, maintaining a substantially low-particle environment within an enclosed system, such as an enclosed OLED printing system, presents additional challenges not presented by particle reduction for processes that can be performed at atmospheric conditions, such as under an open, high-flow, laminar-flow filtered hood. Various embodiments of the gas enclosure system can provide a substantially low-particle environment, for example, but not limited to, through 1) elimination of areas proximal to the substrate where particulate matter can collect; 2) within various embodiments of the particle control system of the present teachings, by containing and evacuating various devices, assemblies, and systems that utilize particle-generating components such as service bundles, which can include bundled cables, wires, and tubing, and the like, as well as components such as fans or linear motion systems that use friction bearings; and 3) by using various inherently low-particle-generating pneumatically operated components, such as, but not limited to, substrate floating tables, air bearings, pneumatically operated robots, and the like. According to various embodiments of the gas enclosure system of the present teachings, the substantially low-particle environment can include a particle control system that includes components for providing a low-particle zone proximal to the substrate during printing.

[0032] As discussed in more detail later herein, direct control of particle generation proximate the substrate to provide a low-particle zone proximate the substrate can be implemented by inclusion of particle-generating elements, by use of low-particle-generating components, and by a combination of inclusion of particle generation and use of particle-generating components. Accordingly, various embodiments of the gas enclosure system can have a particle control system that can include a gas circulation and filtration system in fluid communication with the substrate, the service bundle housing exhaust system, and the low-particle-generating X-axis linear bearing system for moving the printhead assembly relative to the printhead assembly exhaust system. For various embodiments of the service bundle housing exhaust system and the printhead assembly exhaust system, particles contained in such systems can be exhausted into the gas circulation and filtration system. For various embodiments of the service bundle housing exhaust system and the printhead assembly exhaust system, particles contained in such systems can be exhausted into a dead space, thereby making such particulate matter exhausted into the dead space inaccessible for circulation within the gas enclosure system.

[0033] Additionally, system validation and ongoing system monitoring can be performed for both airborne and on-substrate particle monitoring. Airborne particulate matter determination can be performed on various embodiments of the gas enclosure system prior to the printing process as a quality check, for example, using a portable particle counting device. In various embodiments of the gas enclosure system, airborne particulate matter determination can be performed in situ as an ongoing quality check while the substrate is being printed. For various embodiments of the gas enclosure system, airborne particulate matter determination can be performed in situ as a quality check before the substrate is printed, as well as in situ while the substrate is being printed. On-substrate distribution of particulate matter on the substrate can be determined on various embodiments of the gas enclosure system before the substrate is printed for system validation, for example, using a test substrate. In various embodiments of the gas enclosure system, airborne particulate matter distribution on the substrate can be determined in situ as an ongoing quality check while the substrate is being printed, for example, using a camera assembly mounted on the X-axis carriage assembly. For various embodiments of the gas enclosure system, determination of the on-substrate distribution of particulate matter can be performed before the substrate is printed, as well as in situ while the substrate is being printed, for system validation.

[0034] Various embodiments of the gas enclosure system can have a particle control system capable of maintaining a substantially low-particle environment, providing on-substrate particle specifications for particles from about 0.1 μm or larger to about 10 μm or larger. Various embodiments of the on-substrate particle specifications can be easily converted from an average on-substrate particle distribution per square meter of substrate per minute to an average on-substrate particle distribution per substrate per minute for each target particle size range. As previously discussed herein, such conversion can be easily performed, for example, through known relationships between substrates of a particular generation size and substrates of corresponding area for that substrate generation. Additionally, the average on-substrate particle distribution per square meter of substrate per minute can be easily converted to any of a variety of unit time representations. For example, in addition to converting between standard time units, e.g., seconds, minutes, and days, process-specific units of time can be used. For example, print cycles can be associated with units of time, as previously discussed herein.

[0035] Various embodiments of the low-particle gas enclosure system of the present teachings can maintain a low-particle environment that provides an average on-substrate particle distribution that meets an on-substrate deposition rate specification of less than or equal to about 100 particles per square meter of substrate per minute for particles greater than or equal to 10 μm in size. Various embodiments of the low-particle gas enclosure system of the present teachings can maintain a low-particle environment that provides an average on-substrate particle distribution that meets an on-substrate deposition rate specification of less than or equal to about 100 particles per square meter of substrate per minute for particles greater than or equal to 5 μm in size. Various embodiments of the gas enclosure system of the present teachings can maintain a low-particle environment that provides an average on-substrate particle distribution that meets an on-substrate deposition rate specification of less than or equal to about 100 particles per square meter of substrate per minute for particles greater than or equal to 2 μm in size. Various embodiments of the gas enclosure system of the present teachings can maintain a low-particle environment that provides an average on-substrate particle distribution that meets an on-substrate deposition rate specification of less than about 100 particles per square meter of substrate per minute for particles greater than or equal to 1 μm in size. Various embodiments of the low-particle gas enclosure system of the present teachings can maintain a low-particle environment that provides an average on-substrate particle distribution that meets an on-substrate deposition rate specification of less than about 1000 particles per square meter of substrate per minute for particles greater than or equal to 0.5 μm in size. Various embodiments of the gas enclosure system of the present teachings can maintain a low-particle environment that provides an average on-substrate particle distribution that meets an on-substrate deposition rate specification of less than about 1000 particles per square meter of substrate per minute for particles greater than or equal to 0.3 μm in size. Various embodiments of the low-particle gas enclosure system of the present teachings can maintain a low-particle environment that provides an average on-substrate particle distribution that meets an on-substrate deposition rate specification of less than or equal to about 1000 particles per square meter of substrate per minute for particles greater than or equal to 0.1 μm in size.

[0036] Additionally, it is contemplated that the gas enclosure system may have attributes, including, but not limited to, a gas enclosure assembly that can be easily expanded to provide an optimized workspace for an OLED printing system, while providing, for example, a minimized inert gas volume, and that provides immediate access to the OLED printing system from the outside during processing while providing access to the interior for maintenance with minimal downtime. In that regard, various embodiments of the gas enclosure assembly, useful for various air-sensitive processes requiring an inert environment, may include multiple wall and ceiling frame members that can be sealed together. In some embodiments, the multiple wall and ceiling frame members can be fastened together using reusable fasteners, such as bolts and threaded holes. For various embodiments of the gas enclosure assembly according to the present teachings, multiple frame members, each frame member comprising multiple panel frame sections, can be constructed to define a gas enclosure frame assembly. Various embodiments of the gas enclosure assembly may include an auxiliary enclosure constructed as a section of the gas enclosure assembly that can be sealably isolated from the working volume of the gas enclosure system, such as a printing system enclosure. For example, such physical isolation of the auxiliary enclosure from the printing system enclosure can allow various procedures, including but not limited to, various maintenance procedures on the printhead assembly, to be performed with little or no interruption to the printing process, thereby minimizing or eliminating downtime of the gas enclosure system.

[0037] The gas enclosure assembly of the present teachings can be designed to accommodate printing systems, such as OLED printing systems, in a manner that can minimize the volume of the enclosure surrounding the system. Various embodiments of the gas enclosure assembly can be constructed in a manner that minimizes the internal volume of the gas enclosure assembly while optimizing the workspace to accommodate the various footprints of various OLED printing systems. An OLED printing system according to various embodiments of the gas enclosure system of the present teachings can include, for example, one or more devices and apparatuses extending from various embodiments of a pressurized inert gas recirculation system, such as a granite base, a movable bridge that can support an OLED printing device, a substrate floating table, an inkjet printer system for depositing OLED film-forming materials on a substrate, including air bearings, tracks, rails, an OLED ink supply subsystem, and an inkjet printhead, one or more robots, and the like. Considering the various components that can comprise an OLED printing system, various embodiments of the OLED printing system can have various footprints and form factors. Various embodiments of a gas enclosure assembly so constructed additionally provide immediate access to the interior of the gas enclosure assembly from the outside during processing, providing immediate access to the interior for maintenance while minimizing downtime. In that regard, various embodiments of a gas enclosure assembly according to the present teachings can be contoured for various footprints of various OLED printing systems. According to various embodiments, once contoured frame members are constructed to form the gas enclosure frame assembly, various types of panels may be sealably installed within the multiple panel sections comprising the frame members to complete installation of the gas enclosure assembly.In various embodiments of the gas enclosure assembly, for example, a plurality of frame members, including but not limited to a plurality of wall frame members and at least one ceiling frame member, and a plurality of panels for installation into panel-frame sections, may be fabricated at one or more locations and then constructed at another location. Also, given the transportable nature of the components used to construct the gas enclosure assemblies of the present teachings, various embodiments of the gas enclosure assembly may be repeatedly installed and removed through build-and-tear cycles.

[0038] To ensure that the gas enclosure is sealed, various embodiments of the gas enclosure assembly of the present teachings provide for joining each frame member to provide a frame seal. The interior can be fully sealed, for example, by tight-fitting intersections between the various frame members, including gaskets or other seals. Once fully constructed, the sealed gas enclosure assembly can include an interior and multiple interior corner edges, with at least one interior corner edge provided at each frame member's intersection with an adjacent frame member. One or more of the frame members, for example, at least half of the frame members, can include one or more compressible gaskets secured along one or more respective edges thereof. The one or more compressible gaskets can be configured to create a sealed gas enclosure assembly once multiple frame members are joined together and airtight panels are installed. A sealed gas enclosure assembly can be formed having the interior edges of the frame members sealed by multiple compressible gaskets. For each frame member, one or more compressible gaskets may be provided, for example, but not limited to, on the interior wall frame surface, the top wall frame surface, the vertical sidewall frame surface, the bottom wall frame surface, and combinations thereof.

[0039] For various embodiments of the gas enclosure assembly, each frame member can include multiple sections that are framed and machined to receive any of a variety of panel types, which can be sealably installed within each section to provide an airtight panel for each panel. In various embodiments of the gas enclosure assembly of the present teachings, each section frame can have a section frame gasket that ensures that each panel installed within each section frame, using selected fasteners, can provide an airtight seal for each panel and therefore for the fully constructed gas enclosure. In various embodiments, the gas enclosure assembly can have one or more window panels or inspection windows in each of the wall panels, and each window panel or inspection window can have at least one glove port. During assembly of the gas enclosure assembly, each glove port can have a glove attached so that the glove can extend into the interior. According to various embodiments, each glove port can have hardware for mounting the glove, which utilizes a gasket seal around each glove port to provide an airtight seal to minimize leakage or molecular diffusion through the glove port. For various embodiments of the gas enclosure assembly of the present teachings, the hardware is further designed to provide the end user with ease of glove port cap installation and removal.

[0040] Various embodiments of a gas enclosure system according to the present teachings can include a gas enclosure assembly formed from multiple frame members and panel sections, as well as gas circulation, filtration, and purification components. For various embodiments of the gas enclosure system, piping can be installed during the assembly process. According to various embodiments of the present teachings, piping can be installed within a gas enclosure frame assembly constructed from multiple frame members. In various embodiments, piping can be installed on the multiple frame members before they are joined to form the gas enclosure frame assembly. The piping for various embodiments of the gas enclosure system can be configured so that substantially all gas drawn into the piping from one or more piping inlets is transferred through various embodiments of a gas filtration loop to remove particulate matter within the gas enclosure system. Additionally, the piping of various embodiments of the gas enclosure system can be configured to separate the inlet and outlet of a gas purification loop external to the gas enclosure assembly from the gas filtration loop internal to the gas enclosure assembly. According to various embodiments of the gas enclosure system of the present teachings, the gas circulation and filtration system can be in fluid communication with components of, for example, but not limited to, a particle control system. For various embodiments of the gas enclosure assembly, the gas circulation and filtration system can be in fluid communication with a service bundle housing exhaust system. For various embodiments of the gas enclosure assembly, the gas circulation and filtration system can be in fluid communication with a printhead assembly exhaust system. In various embodiments of the gas enclosure system, various components of a particle control system in fluid communication with the gas circulation and filtration system can provide a low particle zone proximate a substrate positioned in the printing system.

[0041] For example, a gas enclosure system can have a gas circulation and filtration system inside the gas enclosure assembly. Such an internal filtration system can have multiple fan filter units inside the interior and can be configured to provide laminar flow of gas within the interior. The laminar flow can be from the top of the interior to the bottom of the interior, or in any other direction. While the gas flow generated by the circulation system need not be laminar, laminar flow of gas can be used to ensure thorough and complete gas turnover within the interior. Laminar flow of gas can also be used to minimize turbulence, which is undesirable because such turbulence can cause particles in the environment to collect in areas of such turbulence and prevent the filtration system from removing these particles from the environment. Furthermore, a thermal conditioning system can be provided that utilizes multiple heat exchangers, for example, operating in conjunction with, adjacent to, or used in conjunction with a fan or another gas circulation device, to maintain a desired temperature within the interior. A gas purification loop can be configured to circulate gas from within the interior of the gas enclosure assembly through at least one gas purification component outside the enclosure. In that regard, the circulation and filtration system internal to the gas enclosure assembly, in conjunction with a gas purification loop external to the gas enclosure assembly, can provide continuous circulation of a substantially low-particle inert gas having substantially low levels of reactive species throughout the gas enclosure system.

[0042] In addition to providing gas circulation, filtration, and purification components, the piping can be sized and shaped to accommodate at least one service bundle therein. According to the present teachings, the service bundle can include, for example, but is not limited to, optical cables, electrical cables, wires, and various fluid-containing tubing, and the like. Various embodiments of the service bundles of the present teachings can have significant dead volume created by gaps formed between the various components of the service bundle. The significant dead volume that can be created in bundling the various optical cables, electrical cables, wires, and fluid-containing tubing can cause significant amounts of reactive atmospheric species, such as water, water vapor, oxygen, and the like, to be trapped in the voids. Such significant amounts of trapped reactive atmospheric species can be difficult to rapidly remove by a purification system. Additionally, such service bundles are identified sources of particulate matter. In some embodiments, any combination of cable, wire, and wire bundles, and fluid-containing tubing can be disposed substantially within the piping and can each be operatively associated with at least one of an optical system, an electrical system, a mechanical system, and a cooling system housed within the gas enclosure system. The gas circulation, filtration, and purification components can be configured so that essentially all of the circulated inert gas is drawn through the piping, thereby effectively removing both particulate matter emanating from such bundles as well as atmospheric constituents trapped in the dead volume of the various bundled materials by substantially containing such bundled components within the piping.

[0043] Various embodiments of gas enclosure systems according to the present teachings can include a gas enclosure assembly formed from a plurality of frame members and panel sections, as well as particle control systems, gas circulation, filtration, and purification components, as well as various embodiments of pressurized inert gas recirculation systems that can be utilized in the operation of OLED printing systems for various pneumatically driven devices and apparatuses, substantially as discussed in further detail herein.

[0044] According to the present teachings, several engineering challenges have been addressed to provide various embodiments of a pressurized inert gas recirculation system in a gas enclosure system. First, under typical operation of a gas enclosure system without a pressurized inert gas recirculation system, the gas enclosure system can be maintained at a slightly positive internal pressure relative to the external pressure to protect against ingress of external gas or air into the interior if any leaks occur within the gas enclosure system. For example, under typical operation, for various embodiments of a gas enclosure system of the present teachings, the interior of the gas enclosure system can be maintained at a pressure relative to the ambient atmosphere outside the enclosure system of, for example, at least 2 mbarg, at least 4 mbarg, at least 6 mbarg, at least 8 mbarg, or higher. Maintaining a pressurized inert gas recirculation system within a gas enclosure system can be challenging because it presents a dynamic and continuous balancing act with respect to maintaining a slight positive internal pressure of the gas enclosure system while simultaneously continuously introducing pressurized gas into the gas enclosure system. Furthermore, variable demands on various devices and equipment can create irregular pressure profiles in the various gas enclosure assemblies and systems of the present teachings. Maintaining dynamic pressure equilibrium in the gas enclosure system, held at a slight positive pressure relative to the external environment under such conditions, can provide for the integrity of the continuous OLED printing process.

[0045] For various embodiments of the gas enclosure system, the pressurized inert gas recirculation system according to the present teachings can include various embodiments of a pressurized inert gas loop that can utilize at least one of a compressor, an accumulator, and a blower, and combinations thereof. Various embodiments of the pressurized inert gas recirculation system, including various embodiments of the pressurized inert gas loop, can have a specially designed pressure-controlled bypass loop that can provide a stable, specified internal pressure of the inert gas within the gas enclosure system of the present teachings. In various embodiments of the gas enclosure system, the pressurized inert gas recirculation system can be configured to recirculate the pressurized inert gas through the pressure-controlled bypass loop when the pressure of the inert gas in the accumulator of the pressurized inert gas loop exceeds a preset threshold pressure. The threshold pressure can be, for example, within a range of about 25 psig to about 200 psig, or more specifically, within a range of about 75 psig to about 125 psig, or more specifically, within a range of about 90 psig to about 95 psig. In that regard, the gas enclosure system of the present teachings, having a pressurized inert gas recirculation system along with various embodiments of specially designed pressure-controlled bypass loops, can maintain the balance of having a pressurized inert gas recirculation system within an airtight gas enclosure.

[0046] According to the present teachings, various devices and apparatuses can be disposed within and fluidly communicate with various embodiments of a pressurized inert gas recirculation system having various pressurized inert gas loops that can utilize various pressurized gas sources, such as at least one of a compressor, a blower, and combinations thereof. For various embodiments of the gas enclosures and systems of the present teachings, the use of various pneumatically operated devices and apparatuses can provide low particle generation performance and be less labor-intensive to maintain. Exemplary devices and apparatuses that can be disposed within the gas enclosure system and fluidly communicated with the various pressurized inert gas loops can include, but are not limited to, one or more of a pneumatic robot, a substrate floating table, air bearings, air bushings, compressed gas tools, pneumatic actuators, and combinations thereof. The substrate floating table and air bearings can be used for various aspects of operating an OLED printing system according to various embodiments of the gas enclosure system of the present teachings. For example, a substrate floating table utilizing air bearing technology can be used to transport a substrate into position within a print head chamber and to support the substrate during the OLED printing process.

[0047] 1A is a right front perspective view of a gas enclosure assembly 100 according to various embodiments of the present teachings. The gas enclosure assembly 100 can be integrated with various components to provide various embodiments of a gas enclosure system of the present teachings. A gas enclosure system of the present teachings can contain one or more gases for maintaining an inert environment within the gas enclosure assembly, as well as components for maintaining a substantially low-particle environment. As non-limiting examples, various embodiments of the gas enclosure system can have a particle control system, which can include a gas circulation and filtration system and purification components for removing reactive species from the recirculated inert gas, and can have various embodiments of a pressurized inert gas recirculation system. Thus, various embodiments of the gas enclosure system of the present teachings can be useful in maintaining an inert, substantially low-particle gas atmosphere therein.

[0048] For example, FIG. 1B is a left front perspective view of various embodiments of a gas enclosure system 500. FIG. 1B depicts the gas enclosure system 500, which can include various embodiments of the gas enclosure assembly 100. The gas enclosure system 500 can have a load lock entry chamber 1110, which can have an entry gate 1112. The gas enclosure system 500 of FIG. 1B can include a gas purification system 3130 for providing the gas enclosure assembly 100 with a constant supply of inert gas having substantially low levels of reactive atmospheric species, such as water vapor and oxygen, as well as organic solvent vapors resulting from the OLED printing process. According to the present teachings, an inert gas may be any gas that does not undergo chemical reactions under a defined set of conditions. Some commonly used, non-limiting examples of inert gases include nitrogen, any of the noble gases, and any combination thereof. Various embodiments of gas purification systems according to the present teachings, such as purification system 3130 of FIG. 1B, can maintain various levels of various reactive species, including various reactive atmospheric gases such as water vapor and oxygen, and organic solvent vapors, at 100 ppm or less, e.g., 10 ppm or less, 1.0 ppm or less, or 0.1 ppm or less.

[0049] The gas enclosure system 500 of FIG. 1B can also have a controller system 1130 for system control functions. For example, the system controller 1130 can include one or more processor circuits (not shown) in communication with one or more memory circuits (not shown). The system controller 1130 can also communicate with the load lock entrance chamber 1110, the exit chamber (not shown), and ultimately the print nozzles of an OLED printing system, which can be housed in the gas enclosure system 500. In this manner, the system controller 1130 can, for example, coordinate the opening of a gate 1112 in the load lock entrance chamber 1110 to allow entry of a substrate into the gas enclosure system 500. The system controller 1130 can control various system functions, such as controlling ink dispensing to the print nozzles of the OLED printing system. The gas enclosure system 500 of FIG. 1B is configured to contain and protect air-sensitive processes, such as printing various inks useful for creating OLED stacks using a commercial printing system. Examples of atmospheric gases that react with OLED inks include water vapor and oxygen, as well as various organic vapors, for example, from organic solvents used as carriers for various OLED inks. As previously discussed herein, the gas enclosure assembly 100 can be configured to maintain a sealed atmosphere and allow components or printing systems to operate effectively, while the gas enclosure system 500 can provide all of the components necessary to maintain an inert environment. In addition, the gas enclosure 500 can have a particle control system that provides a low-particle zone proximal to the substrate, which can include components such as a gas circulation and filtration system, a low-particle-generating X-axis linear bearing system for moving the printhead assembly relative to the substrate, a service bundle housing exhaust system, and a printhead assembly exhaust system, by way of non-limiting examples.

[0050] As depicted in FIG. 1A , various embodiments of gas enclosure assembly 100 can comprise component parts including a front or first wall panel 210′, a left or second wall panel (not shown), a right or third wall panel 230′, a rear or fourth wall panel (not shown), and a ceiling panel 250′, which can be mounted to a pan 204 that rests on a base (not shown). As discussed in more detail later herein, various embodiments of gas enclosure assembly 100 of FIG. 1A can be constructed from a front or first wall frame 210, a left or second wall frame (not shown), a right or third wall frame 230, a rear or fourth wall panel (not shown), and a ceiling frame 250. Various embodiments of ceiling frame 250 can include a fan filter unit cover 103, and first and second ceiling frame ducts 105 and 107. According to embodiments of the present teachings, various types of section panels can be installed within any of a plurality of panel sections comprising frame members. 1, sheet metal panel sections 109 can be welded into the frame members during construction of the frame. For various embodiments of gas enclosure assembly 100, types of section panels that can be repeatedly installed and removed throughout construction and teardown cycles of the gas enclosure assembly can include inset panels 110, as shown for wall panel 210', and window panels 120 and easily removable inspection windows 130, as shown for wall panel 230'.

[0051] While the easily removable inspection window 130 can provide immediate access to the interior of the enclosure 100, any removable panel can be used to provide access to the interior of the gas enclosure system for purposes of repair and routine maintenance. Such access for maintenance or repair is distinct from the access provided by panels such as the window panel 120 and the easily removable inspection window 130, which can provide end-user glove access from the exterior of the gas enclosure assembly to the interior of the gas enclosure assembly during use. For example, as shown in FIG. 1A for panel 230, any of the gloves, such as glove 142 attached to glove port 140, can provide end-user access to the interior during use of the gas enclosure system.

[0052] FIG. 2 depicts an exploded view of various embodiments of the gas enclosure assembly depicted in FIG. 1A. Various embodiments of the gas enclosure assembly can have multiple wall panels, including an exterior perspective view of a front wall panel 210′, an exterior perspective view of a left wall panel 220′, an interior perspective view of a right wall panel 230′, an interior perspective view of a rear wall panel 240′, and a top perspective view of a ceiling panel 250′, which can be attached to a pan 204 resting on a base 202, as shown in FIG. 1A. An OLED printing system can be mounted on the pan 204, and the printing process is known to be sensitive to atmospheric conditions. According to the present teachings, the gas enclosure assembly can be constructed from frame members, such as a wall frame 210 for the wall panel 210′, a wall frame 220 for the wall panel 220′, a wall frame 230 for the wall panel 230′, a wall frame 240 for the wall panel 240′, and a ceiling frame 250 for the ceiling panel 250′, into which multiple section panels can then be installed. In that regard, it may be desirable to streamline the design of section panels that can be repeatedly installed and removed throughout the construction and teardown cycles of various embodiments of the gas enclosure assembly of the present teachings. Also, to minimize the amount of inert gas required in the gas enclosure assembly, the gas enclosure assembly 100 can be contoured to accommodate the footprint of various embodiments of the OLED printing system while providing ready access to the end user both during use and maintenance of the gas enclosure assembly.

[0053] Using front wall panel 210′ ​​and left wall panel 220′ as examples, various embodiments of the frame members can have sheet metal panel sections 109 welded into the frame members during frame member construction. Inset panels 110, window panels 120, and easily removable inspection windows 130 can be installed within each of the wall frame members and can be repeatedly installed and removed throughout the construction and disassembly cycles of the gas enclosure assembly 100 of FIG. 2. As shown in the figures, in the examples of wall panel 210′ ​​and wall panel 220′, the wall panels can have the window panel 120 proximate the easily removable inspection window 130. Similarly, as depicted in exemplary rear wall panel 240′, the wall panel can have a window panel, such as window panel 125, with two adjacent glove ports 140. As seen for various embodiments of wall frame members according to the present teachings and for the gas enclosure assembly 100 of FIG. 1A, such an arrangement of the glove ports provides easy access to component parts within the enclosure system from outside the gas enclosure. Thus, various embodiments of the gas enclosure may provide two or more glove ports to allow an end user to extend the left and right gloves into the interior and manipulate one or more items within the interior without disturbing the composition of the gas atmosphere within the interior. For example, either of the window panel 120 and the inspection window 130 may be positioned to facilitate easy access to adjustable components within the gas enclosure assembly from outside the gas enclosure assembly. According to various embodiments of window panels, such as the window panel 120 and the inspection window 130, when end user access through the glove port gloves is not indicated, such windows may not include glove ports and glove port assemblies.

[0054] Various embodiments of the wall and ceiling panels as depicted in FIG. 2 can have multiple inset panels 110. As can be seen in FIG. 2, the inset panels can have various shapes and aspect ratios. In addition to the inset panels, the ceiling panel 250′ can have a fan filter unit cover 103 and a first ceiling frame duct 105 and a second ceiling frame duct 107 mounted, bolted, screwed, fastened, or otherwise secured to the ceiling frame 250. As discussed in more detail later herein, piping in fluid communication with the duct 107 of the ceiling panel 250′ can be installed within the interior of the gas enclosure assembly. According to the present teachings, such piping can be part of a gas circulation system within the gas enclosure assembly and provides for separation of flow exiting the gas enclosure assembly for circulation through at least one gas purification component external to the gas enclosure assembly.

[0055] 3 is an exploded front perspective view of a frame member assembly 200 from which a wall frame 220 can be constructed to include a full complement of panels. While not limited to the design shown, frame member assembly 200 using wall frame 220 can be used as an example of various embodiments of a frame member assembly according to the present teachings. Various embodiments of a frame member assembly according to the present teachings can consist of various frame members and section panels installed within various frame panel sections of the various frame members.

[0056] According to various embodiments of the frame member assemblies of the present teachings, the frame member assembly 200 can be comprised of frame members such as wall frames 220. For various embodiments of gas enclosure assemblies, such as the gas enclosure assembly 100 of FIG. 1A, processes that may utilize equipment housed in such gas enclosure assemblies may require not only a sealed enclosure that provides an inert environment, but also an environment that is substantially free of particulate matter. In that regard, frame members according to the present teachings may utilize variously dimensioned metal tubing for construction of various embodiments of the frame. Such metal tubing addresses desired material attributes, including, but not limited to, high integrity materials that will not decompose to produce particulate matter, while producing frame members with high strength yet optimal weight, providing for rapid transportation, construction, and dismantling of gas enclosure assemblies comprising various frame members and panel sections from one site to another. According to the present teachings, any material that meets these requirements can be utilized to create the various frame members of the present teachings.

[0057] For example, various embodiments of frame members according to the present teachings, such as frame member assembly 200, can be constructed from extruded metal tubing. According to various embodiments of frame members, aluminum, steel, and various metal composite materials may be utilized to construct the frame members. In various embodiments, metal tubing having dimensions of, for example, but not limited to, 2 inches wide by 2 inches high, 4 inches wide by 2 inches high, and 4 inches wide by 4 inches high, and having wall thicknesses of 1 / 8 inch to 1 / 4 inch, can be used to construct various embodiments of frame members of the present teachings. In addition, various reinforced fiber-polymer composite materials in various tubes or other forms can be utilized to produce frame members having material attributes, including, but not limited to, high integrity materials that will not degrade and produce particulate matter, as well as high strength, yet optimal weight, providing for rapid transportation, construction, and teardown from one site to another.

[0058] With regard to the construction of various frame members from variously sized metal tubing materials, it is contemplated that welding can be performed to create various embodiments of frame welds. Additionally, construction of various frame members from variously sized building materials can be performed using appropriate industrial adhesives. It is contemplated that construction of various frame members should be performed in a manner that will not essentially create a leak path through the frame members. In that regard, construction of various frame members can be performed using any approach that will not essentially create a leak path through the frame members of various embodiments of a gas enclosure assembly. Furthermore, various embodiments of frame members according to the present teachings, such as the wall frame 220 of FIG. 2 , may be painted or coated. For various embodiments of frame members made from metal tubing materials that are prone to oxidation, for example, where material formed on the surface can create particulate matter, painting, coating, or other surface treatments, such as anodizing, that prevent the formation of particulate matter can be performed.

[0059] A frame member assembly, such as the frame member assembly 200 of FIG. 3, can have a frame member, such as a wall frame 220. The wall frame 220 can have a top portion 226 onto which a top wall frame spacer plate 227 can be fastened, and a bottom portion 228 onto which a bottom wall frame spacer plate 229 can be fastened. As discussed in more detail later herein, the spacer plate mounted on the surface of the frame member is part of a gasket sealing system that, in conjunction with the gasket sealing of the panels mounted within the frame member section, provides sealing for various embodiments of a gas enclosure assembly according to the present teachings. A frame member, such as the wall frame 220 of the frame member assembly 200 of FIG. 3, can have several panel frame sections, each of which can be machined to accept various types of panels, such as, but not limited to, the inset panel 110, the window panel 120, and the easily removable inspection window 130. Various types of panel sections can be formed in the construction of the frame member. The types of panel sections may include, but are not limited to, for example, an inset panel section 10 for receiving an inset panel 110, a window panel section 20 for receiving a window panel 120, and an inspection window panel section 30 for receiving an easily removable inspection window 130.

[0060] Each type of panel section can have a panel section frame that receives the panel, allowing each panel to be sealably fastened therein according to the present teachings to construct a sealed gas enclosure assembly. For example, in FIG. 3 , which depicts a frame assembly according to the present teachings, inset panel section 10 is shown having frame 12, window panel section 20 is shown having frame 22, and inspection window panel section 30 is shown having frame 32. For various embodiments of the wall frame assembly of the present teachings, the various panel section frames can be sheet metal materials welded into the panel sections with a continuous weld bead to provide a seal. For various embodiments of the wall frame assembly, the various panel section frames can be made from various sheet materials, including building materials selected from reinforced fiber polymer composites, which can be placed into the panel sections using a suitable industrial adhesive. As discussed in more detail in subsequent teachings regarding sealing, each panel section frame can have a compressible gasket disposed thereon to ensure an airtight seal can be formed for each panel installed and fastened therein. In addition to the panel section frame, each frame member section may have hardware associated with positioning the panels as well as securely fastening the panels within the panel section.

[0061] Various embodiments of the panel frames 122 for the inset panels 110 and window panels 120 can be constructed from sheet metal materials, such as, but not limited to, aluminum and various alloys of aluminum and stainless steel. The attributes for the panel materials can be the same as the attributes for the structural materials comprising the various embodiments of the frame members. In that regard, materials with attributes for the various panel members include, but are not limited to, high-integrity materials that will not decompose and produce particulate matter, while producing panels with high strength yet optimal weight for easy transport, construction, and teardown from one site to another. For example, various embodiments of honeycomb core sheet material can have the necessary attributes for use as the panel material for the construction of the panel frames 122 for the inset panels 110 and window panels 120. Honeycomb core sheet materials can be made from a variety of materials, both metals, as well as metal composites and polymers, and polymer composite honeycomb core sheet materials. Various embodiments of the removable panels, when fabricated from metal materials, can have a ground connection included in the panel to ensure the entire structure is grounded when the gas enclosure assembly is constructed.

[0062] Given the transportable nature of the components used to construct the gas enclosure assembly of the present teachings, any of the various embodiments of the division panels of the present teachings can be repeatedly installed and removed during use of the gas enclosure system to provide access to the interior of the gas enclosure assembly.

[0063] For example, a panel section 30 for receiving a readily removable inspection window panel 130 can have a set of four spacers, one of which is shown as a window guide spacer 34. In addition, a panel section 30 constructed to receive a readily removable inspection window panel 130 can have a set of four fastening cleats 36 that can be used to fasten the inspection window 130 into the inspection window panel section 30 using a set of four reverse-action toggle clamps 136 mounted on the inspection window frame 132 for each of the easily removable inspection windows 130. Furthermore, two of each of the window handles 138 can be mounted on the easily removable inspection window frame 132 to provide ease of removal and installation of the inspection window 130 to the end user. The number, type, and placement of the removable inspection window handles can be varied. In addition, a panel section 30 for receiving a readily removable inspection window panel 130 can have at least two window clamps 35 selectively installed in each inspection window panel section 30. Although depicted as being within the top and bottom of each of the inspection window panel sections 30, the at least two window clamps can be installed in any manner that acts to secure the inspection window 130 within the panel section frame 32. A tool can be used to remove and install the window clamps 35 to allow the inspection window 130 to be removed and reinstalled.

[0064] The hardware installed on the panel section 30, including the reverse action toggle clamp 136 of the inspection window 130, as well as the fastening cleat 36, window guide spacer 34, and window clamp 35, can be constructed of any suitable material and combination of materials. For example, one or more such elements can include at least one metal, at least one ceramic, at least one plastic, and combinations thereof. The removable access window handle 138 can be constructed of any suitable material and combination of materials. For example, one or more such elements can include at least one metal, at least one ceramic, at least one plastic, at least one rubber, and combinations thereof. An enclosure window, such as the window 124 of the window panel 120 or the window 134 of the access window 130, can include any suitable material and combination of materials. According to various embodiments of the gas enclosure assembly of the present teachings, the enclosure window can include transparent and translucent materials. In various embodiments of the gas enclosure assembly, the enclosure window can include silica-based materials, such as, but not limited to, glass and quartz, and various types of polymer-based materials, such as, but not limited to, various classes of polycarbonate, acrylic, and vinyl. In accordance with the systems and methods of the present teachings, the transparent and translucent properties of various composite materials and combinations thereof are desirable attributes for exemplary window materials.

[0065] As discussed in the teachings below with respect to Figures 8A-9B, the wall and ceiling frame member seals, together with the airtight compartment panel frame seals, provide various embodiments of a sealed gas enclosure assembly for air-sensitive processes requiring an inert environment. Components of a gas enclosure system that contribute to providing a substantially low concentration of reactive species and a substantially low-particle environment can include, but are not limited to, a sealed gas enclosure assembly and a highly effective gas circulation and particle filtration system, including piping. Providing effective seals for a gas enclosure assembly can be difficult, especially when three frame members fit together to form a three-sided joint. Thus, three-sided joint seals present a particularly difficult challenge with respect to providing an easily installable seal for a gas enclosure assembly that can be assembled and disassembled through construction and teardown cycles.

[0066] In that regard, various embodiments of gas enclosure assemblies according to the present teachings provide effective gasket sealing around load-bearing building components, as well as sealing of the fully constructed gas enclosure system through effective gasket sealing of the joints. Unlike conventional joint seals, joint seals according to the present teachings 1) include uniform parallel alignment of adjacent gasket segments from orthogonally oriented gasket lengths at the top and bottom end frame joint junctions where three frame members are joined, thereby avoiding angular seam alignment and sealing; 2) provide for adjacent lengths across the entire width of the joint, thereby increasing the sealing contact area at the three-sided joint junction; and 3) are designed with spacer plates that provide uniform compressive force across all vertical and horizontal, as well as top and bottom three-sided joint gasket seals. Additionally, the selection of gasket material can affect the effectiveness of providing a seal, as will be discussed later.

[0067] 4A-4C are top-view schematic diagrams depicting a comparison of a conventional three-sided joint seal with a three-sided joint seal according to the present teachings. According to various embodiments of the gas enclosure assembly of the present teachings, for example, but not limited to, there may be at least four wall frame members, ceiling frame members, and pans that can be joined to form a gas enclosure assembly, creating multiple vertical, horizontal, and three-sided joints that require sealing. In FIG. 4A, there is a top-view schematic diagram of a conventional three-sided gasket seal formed from a first gasket I that is orthogonally oriented relative to gasket II in the XY plane. As shown in FIG. 4A, the seam formed from the orthogonal orientation in the XY plane has a contact length W1 between the two sections defined by the width dimension of the gasket. Additionally, the end portion of gasket III, the gasket that is orthogonally oriented relative to both gasket I and gasket II in the vertical direction, can be adjacent to gasket I and gasket II, as indicated by the diagonal lines. In Figure 4B, there is shown a top-view schematic of a conventional three-sided bonded gasket seal formed from a first gasket length I with a seam perpendicular to a second gasket length II, joining the 45° faces of both lengths, the seam having a contact length W2 between the two sections greater than the width of the gasket material. Similar to the configuration in Figure 4A, an end portion of Gasket III, which is perpendicular to both Gasket I and Gasket II, can abut Gasket I and Gasket II, as indicated by the diagonal lines. Assuming the gasket width is the same in Figures 4A and 4B, the contact length W2 in Figure 4B is greater than the contact length W1 in Figure 4A.

[0068] 4C is a top schematic view of a three-sided bonded gasket seal according to the present teachings. A first gasket length I can have a gasket section I' formed perpendicular to the direction of the gasket length I, with the gasket section I' having a length that can be approximately the dimension of the width of the structural components being joined, such as 4-inch wide by 2-inch high or 4-inch wide by 4-inch high metal tubing used to form various wall frame members of the gas enclosure assemblies of the present teachings. Gasket II has a gasket section II' that is perpendicular to gasket I in the XY plane and has an overlap length with gasket section I' that is approximately the width of the structural components being joined. The widths of gasket sections I' and II' are the widths of the selected compressible gasket material. Gasket III is oriented orthogonally to both gasket I and gasket II in the vertical direction. Gasket section III' is an end portion of gasket III. Gasket section III' is formed from the orthogonal orientation of gasket section III' relative to the vertical length of gasket III. Gasket section III' can be formed to have approximately the same length as gasket sections I' and II' and a width that is the thickness of the selected compressible gasket material. In that regard, the contact length W3 of the three aligned sections shown in Figure 4C is greater than the conventional triangular joint seal shown in either Figure 4A or 4B, which have contact lengths W1 and W2, respectively.

[0069] In that regard, the three-sided joint gasket seal according to the present teachings creates uniform parallel alignment of gasket segments at the end joint junction from what would otherwise be orthogonally aligned gaskets, as shown in the case of FIG. 4A or FIG. 4B. Such uniform parallel alignment of the three-sided joint gasket seal segments provides for the application of a uniform lateral sealing force across the segments to promote a sealed three-sided joint seal at the top and bottom corners of the joint formed from the wall frame members. In addition, each segment of the uniformly aligned gasket segments for each three-sided joint seal is selected to be approximately the width of the structural components being joined, providing a maximum contact length for the uniformly aligned segments. The joint seal according to the present teachings is also designed with spacer plates that provide a uniform compressive force across all vertical, horizontal, and three-sided gasket seals of the building joint. It may be argued that the width of the gasket material selected for a conventional three-sided seal, as given for the example of FIG. 6A or FIG. 6B, can be at least the width of the structural components being joined.

[0070] The exploded perspective view of FIG. 5A depicts a seal assembly 300 according to the present teachings before all frame members have been joined, with the gaskets depicted in an uncompressed state. In FIG. 5A, multiple wall frame members, such as wall frame 310, wall frame 350, and ceiling frame 370, can be sealably joined in the first step of constructing a gas enclosure from the various components of the gas enclosure assembly. Frame member seals according to the present teachings are a large part of providing a seal that results in the gas enclosure assembly being sealed once fully constructed and can be implemented throughout the construction and teardown cycles of the gas enclosure assembly. While the embodiments given in the following teachings for FIGS. 5A-5B are for sealing a portion of a gas enclosure assembly, such teachings apply to any entire gas enclosure assembly of the present teachings.

[0071] The first wall frame 310 depicted in FIG. 5A can have an inner side 311 on which a spacer plate 312 rests, vertical sides 314, and a top surface 315 on which a spacer plate 316 rests. The first wall frame 310 can have a first gasket 320 disposed within and adhered to the space formed by the spacer plate 312. The gap 302 remaining after the first gasket 320 is disposed within and adhered to the space formed by the spacer plate 312 can span the vertical length of the first gasket 320, as shown in FIG. 5A. As depicted in FIG. 5A, the flexible gasket 320 can be disposed within and adhered to the space formed by the spacer plate 312 and can have a vertical gasket length 321, a curved gasket length 323, and a gasket length 325 formed on the interior frame member 311 at 90° in-plane to the vertical gasket length 321 and terminating at the vertical side 314 of the wall frame 310. 5A, first wall frame 310 can have a top surface 315 upon which spacer plate 316 rests, thereby forming a space above surface 315 upon which second gasket 340 can be placed and adhered proximate inner edge 317 of wall frame 310. Gap 304, which remains after second gasket 340 is placed within and adhered to the space formed by spacer plate 316, can span the horizontal length of second gasket 340, as shown in FIG. 5A. Furthermore, as indicated by the diagonal lines, length 345 of gasket 340 is uniformly parallel to and adjacently aligned with length 325 of gasket 320.

[0072] The second wall frame 350 depicted in FIG. 5A can have outer frame sides 353, vertical sides 354, and a top surface 355 upon which a spacer plate 356 rests. The second wall frame 350 can have a first gasket 360 disposed within and adhered to a first gasket space formed from the spacer plate 356. The gap 306 remaining after the first gasket 360 is disposed within and adhered to the space formed from the spacer plate 356 can span the horizontal length of the first gasket 360, as shown in FIG. 5A. As depicted in FIG. 5A, the flexible gasket 360 can have a vertical length 361, a curved length 363, and a length 365 formed at 90° in-plane on the top surface 355 and terminating at the outer frame member 353.

[0073] As shown in the exploded perspective view of FIG. 5A , interior frame member 311 of wall frame 310 can be joined to vertical side 354 of wall frame 350 to form one architectural joint of the gas enclosure frame assembly. Regarding sealing of the architectural joint thus formed, in various embodiments of gasket sealing at end-joint joints of wall frame members according to the present teachings depicted in FIG. 5A , length 325 of gasket 320, length 365 of gasket 360, and length 345 of gasket 340 are all adjacent and uniformly aligned. Additionally, as discussed in more detail later herein, various embodiments of spacer plates according to the present teachings can provide uniform compression of between about 20% and about 40% deflection of the compressible gasket material used to seal various embodiments of the gas enclosure assembly of the present teachings.

[0074] FIG. 5B depicts a sealing assembly 300 according to the present teachings after all frame members have been joined, with the gasket depicted in a compressed state. FIG. 5B is a perspective view detailing the corner seal of the three-sided joint formed at the top-end joint junction between the first wall frame 310, the second wall frame 350, and the ceiling frame 370, shown in perspective. As shown in FIG. 5B, the gasket space defined by the spacer plate can be determined to be of a width such that, upon joining the wall frame 310, the wall frame 350, and the ceiling frame 370, shown in perspective, uniform compression of between about 20% and about 40% deflection of the compressible gasket material to form the vertical, horizontal, and three-sided gasket seals can ensure that the gasket seal at all surfaces sealed at the joint of the wall frame members can provide a seal. Additionally, gasket gaps 302, 304, and 306 (not shown) are formed. ) are sized so that, upon optimum compression of between about 20% and about 40% deflection of the compressible gasket material, each gasket is capable of filling the gasket gaps, such as those shown for gaskets 340 and 360 in FIG. 5B. Thus, in addition to providing uniform compression by defining the space into which each gasket is placed and adhered, various embodiments of spacer plates designed to provide gaps also ensure that each compressed gasket can conform within the space defined by the spacer plates without wrinkles, bulging, or otherwise forming irregularly in compression in a manner that could create leak paths.

[0075] According to various embodiments of the gas enclosure assembly of the present teachings, various types of section panels can be sealed using compressible gasket materials disposed on each of the panel section frames. The location and material of the compressible gaskets used to form seals between the various section panels and the panel section frames, in conjunction with the frame member gasket seals, can provide a sealed gas enclosure assembly with little or no gas leakage. In addition, the sealing designs for all types of panels, such as the inset panel 110, window panel 120, and easily removable inspection window 130 of FIG. 3, can provide durable panel seals after repeated removal and installation of such panels, which may be required, for example, for accessing the interior of the gas enclosure assembly for maintenance.

[0076] 6A is an exploded view depicting an inspection window panel section 30 and a readily removable inspection window 130. As previously discussed herein, the inspection window panel section 30 can be machined to accept the readily removable inspection window 130. For various embodiments of the gas enclosure assembly, a panel section, such as the removable inspection panel section 30, can have a panel section frame 32 and a compressible gasket 38 disposed on the panel section frame 32. In various embodiments, the hardware involved in fastening the readily removable inspection window 130 within the removable inspection window panel section 30 can provide ease of installation and reinstallation to an end user while ensuring that an airtight seal is maintained when the readily removable inspection window 130 is installed and reinstalled within the panel section 30 as needed by an end user requiring direct access to the interior of the gas enclosure assembly. The readily removable inspection window 130 can include a rigid window frame 132, which can be constructed from, for example, but not limited to, metal tubing such as those described for constructing any of the frame members of the present teachings. The sight glass 130 may utilize quick acting fastening hardware, such as, but not limited to, a reverse action toggle clamp 136, to provide the end user with instant removal and reinstallation of the sight glass 130.

[0077] As shown in the front view of the removable inspection window panel section 30 in FIG. 6A, the easily removable inspection window 130 can have a set of four toggle clamps 136 secured onto the window frame 132. The inspection window 130 can be positioned within the panel section frame 30 at a specified distance to ensure proper compression against the gasket 38. As shown in FIG. 6B, a set of four window guide spacers 34 can be used and installed at each corner of the panel section 30 to position the inspection window 130 within the panel section 30. Each of the set of clamping cleats 36 can be provided to receive the counter-action toggle clamps 136 of the easily removable inspection window 130. According to various embodiments for sealing the inspection window 130 through installation and removal cycles, the combination of the mechanical strength of the inspection window frame 132, along with the defined position of the inspection window 130 provided by the set of window guide spacers 34 relative to the compressible gasket 38, can ensure that once the inspection window 130 is secured in place, using, for example, but not limited to, a reverse-action toggle clamp 136 fastened within each fastening cleat 36, the inspection window frame 132 can provide even pressure across the panel section frame 32 with a defined compression as set by the set of window guide spacers 34. The set of window guide spacers 34 are positioned such that the compressive force of the window 130 on the gasket 38 deflects the compressible gasket 38 between about 20% and about 40%. In that regard, the construction of the inspection window 130, as well as the processing of the panel section 30, provides an airtight seal of the inspection window 130 within the panel section 30. As previously discussed herein, the inspection window 130 is fastened into the panel section 30 and the window clamp 35 can be installed into the panel section 30 after the inspection window 130 has been removed when it needs to be removed.

[0078] The reverse action toggle clamp 136 can be easily secured to the removable inspection window frame 132 using any suitable means and combinations of means. Examples of suitable securing means that can be used include at least one adhesive, such as, but not limited to, epoxy or cement, at least one bolt, at least one screw, at least one other fastener, at least one slot, at least one track, at least one weld, and combinations thereof. The reverse action toggle clamp 136 can be connected to the removable inspection window frame 132 directly or indirectly through an adapter plate. The reverse action toggle clamp 136, the clamping cleat 36, the window guide spacer 34, and the window clamp 35 can be constructed of any suitable materials and combinations of materials. For example, one or more such elements can include at least one metal, at least one ceramic, at least one plastic, and combinations thereof.

[0079] In addition to sealing the easily removable inspection windows, airtight seals can also be provided for the inset panels and window panels. Other types of section panels that can be repeatedly installed and removed within a panel section include, but are not limited to, inset panels 110 and window panels 120, as shown in FIG. 3. As can be seen in FIG. 3, the panel frame 122 of the window panel 120 is constructed similarly to the inset panel 110. As such, according to various embodiments of the gas enclosure assembly, the fabrication of the panel sections to receive the inset panels and window panels can be identical. In that regard, the sealing of the inset panels and window panels can be implemented using the same principles.

[0080] 7A and 7B , according to various embodiments of the present teachings, any of the panels of a gas enclosure, such as the gas enclosure assembly 100 of FIG. 1 , can include one or more inset panel sections 10, which can have a frame 12 configured to receive a respective inset panel 110. FIG. 7A is a perspective view of the enlarged portion shown in FIG. 7B . In FIG. 7A , the inset panel 110 is depicted positioned relative to the inset frame 12. As can be seen in FIG. 7B , the inset panel 110 is affixed to the frame 12, which can be constructed of, for example, metal. In some embodiments, the metal can include aluminum, steel, copper, stainless steel, chromium, alloys, and combinations thereof, and the like. A plurality of blind-screw holes 14 can be made in the inset panel section frame 12. The panel section frame 12 is constructed with a gasket 16 between the inset panel 110 and the frame 12, in which a compressible gasket 18 can be disposed. The blind tapped holes 14 may be of the M5 variety. Screws 15 may be received by the blind tapped holes 14 with a gasket 16 between the inset panel 110 and the frame 12. Once fastened in place against the gasket 16, the inset panel 110 forms an airtight seal within the inset panel section 10. As previously discussed herein, such panel sealing can be implemented for a variety of section panels, including, but not limited to, the inset panel 110 and window panel 120 as shown in FIG. 3.

[0081] According to various embodiments of compressible gaskets according to the present teachings, compressible gasket materials for frame member and panel sealing can be selected from a variety of compressible polymeric materials, such as, but not limited to, any of the classes of closed-cell polymeric materials, also referred to in the art as expanded rubber or expanded polymeric materials. Briefly, closed-cell polymers are prepared in a manner in which gas is trapped in discrete cells, each of which is encapsulated by a polymeric material. Properties of compressible closed-cell polymeric gasket materials desirable for use in hermetically sealing frame and panel components include, but are not limited to, being robust against chemical attack across a wide range of chemical species, possessing excellent moisture barrier properties, being elastic over a wide temperature range, and being resistant to permanent compression set. Generally, closed-cell polymeric materials have higher dimensional stability, lower moisture absorption coefficients, and higher strength compared to open-cell polymeric materials. Various types of polymeric materials from which closed cell polymeric materials can be made include, but are not limited to, for example, silicone, neoprene, ethylene propylene diene terpolymer (EPT), polymers and composites made using ethylene propylene diene monomer (EPDM), vinyl nitrile, styrene butadiene rubber (SBR), and various copolymers and blends thereof.

[0082] The desirable material properties of closed-cell polymers are maintained only if the cells containing the bulk material remain intact during use. In that regard, using such materials in a manner that exceeds the material specifications established for closed-cell polymers, such as specifications for use within a specified temperature or compression range, can cause degradation of the gasket seal. In various embodiments of closed-cell polymer gaskets used to seal frame members and section panels within frame-panel sections, the compression of such materials should not exceed between about 50% and about 70% deflection, and for optimal performance, may be between about 20% and about 40% deflection.

[0083] In addition to closed-cell compressible gasket materials, another example of a class of compressible gasket materials having desirable attributes for use in constructing embodiments of gas enclosure assemblies according to the present teachings includes hollow-extruded compressible gasket materials. Hollow-extruded gasket materials as a class of materials have desirable attributes, including, but not limited to, they are robust against chemical attack across a wide range of chemical species, possess excellent moisture barrier properties, are elastic over a wide temperature range, and are resistant to permanent compression set. Such hollow-extruded compressible gasket materials can be supplied in a wide variety of shape factors, such as, but not limited to, U-shaped cells, D-shaped cells, square cells, rectangular cells, and any of a variety of custom shape factor hollow-extruded gasket materials. The various hollow-extruded gasket materials can be fabricated from polymeric materials used in closed-cell compressible gasket fabrication. For example, without limitation, various embodiments of hollow extruded gaskets can be fabricated from silicone, neoprene, ethylene propylene diene terpolymer (EPT), polymers and composites made using ethylene propylene diene monomer (EPDM), vinyl nitrile, styrene butadiene rubber (SBR), and various copolymers and blends thereof. Compression of such hollow cell gasket materials should not exceed approximately 50% deflection to maintain desired attributes. While classes of closed-cell compressible gasket materials and hollow-extruded compressible gasket materials are provided as examples, any compressible gasket material having the desired attributes can be used to seal structural components such as various wall and ceiling frame members, and to seal various panels within panel segment frames, as defined by the present teachings.

[0084] FIG. 8 is a bottom view of various embodiments of a ceiling panel of the present teachings, such as, for example, ceiling panel 250′ of gas enclosure assembly 100 of FIG. 1A . According to various embodiments of the present teachings for assembling a gas enclosure, lighting can be installed on the interior top surface of a ceiling panel, such as ceiling panel 250′ of gas enclosure assembly 100 of FIG. 1A . As depicted in FIG. 8 , a ceiling frame 250 having an interior 251 can have lighting installed on the interior of various frame members. For example, ceiling frame 250 can have two ceiling frame sections 40 having two ceiling frame beams 42 and 44 in common. Each ceiling frame section 40 can have a first side 41 positioned toward the interior of ceiling frame 250 and a second side 43 positioned toward the exterior of ceiling frame 250. For various embodiments of the present teachings for providing lighting for a gas enclosure, multiple pairs of lighting elements 46 can be installed. Each pair of lighting elements 46 can include a first lighting element 45 proximate the first side 41 and a second lighting element 47 proximate the second side 43 of the ceiling frame section 40. The number, positioning, and grouping of lighting elements shown in FIG. 8 are exemplary. The number and grouping of lighting elements can be varied in any desired or suitable manner. In various embodiments, the lighting elements can be mounted flat, while in other embodiments, they can be mounted so that they can be moved to various positions and angles. The placement of lighting elements is not limited to the top panel ceiling 433, but can additionally or alternatively be located on any other interior, exterior, and surface combination of the gas enclosure assembly 100 shown in FIG. 1A.

[0085] The various lighting elements can include any number, type, or combination of lights, such as halogen lamps, white light lamps, incandescent lamps, arc lamps, or light-emitting diodes or devices (LEDs). For example, each lighting element can include from 1 LED to about 100 LEDs, from about 10 LEDs to about 50 LEDs, or more than 100 LEDs. The LEDs or other lighting devices can emit any color or combination of colors within the color spectrum, outside the color spectrum, or a combination thereof. According to various embodiments of a gas enclosure assembly used in inkjet printing of OLED materials, because some materials are sensitive to certain wavelengths of light, the wavelengths of light of the lighting devices installed within the gas enclosure assembly can be specifically selected to avoid material degradation during processing. For example, 4x cool white LEDs can be used as well as 4x yellow LEDs, or any combination thereof. An example of a 4x cool white LED is the LF1B-D4S-2THWW4 available from IDEC Corporation (Sunnyvale, California). An example of a 4X yellow LED that can be used is the LF1B-D4S-2SHY6, also available from IDEC Corporation. The LEDs or other lighting elements can be positioned or suspended from any location on the interior 251 of the ceiling frame 250 or another surface of the gas enclosure assembly. The lighting elements are not limited to LEDs. Any suitable lighting element or combination of lighting elements can be used. FIG. 9 is a graph of IDEC LED light spectra, showing the X-axis corresponding to intensity when the peak intensity is 100% and the Y-axis corresponding to wavelength in nanometers. The spectra of an LF1B yellow, yellow fluorescent lamp, an LF1B white LED, an LF1B cool white LED, and an LF1B red LED are shown. Other light spectra and combinations of light spectra can be used in accordance with various embodiments of the present teachings.

[0086] Recall that various embodiments of the gas enclosure assembly are constructed in a manner that minimizes the internal volume of the gas enclosure assembly while optimizing the workspace to accommodate the various footprints of various OLED printing systems. Various embodiments of the gas enclosure assembly so constructed additionally provide immediate access to the interior of the gas enclosure assembly from the outside during processing for immediate access to the interior for maintenance while minimizing downtime. In that regard, various embodiments of the gas enclosure assembly according to the present teachings can be contoured for the various footprints of various OLED printing systems.

[0087] According to the systems and methods of the present teachings, frame member structures, panel structures, frame and panel seals, and structures of gas enclosures, such as the gas enclosure 100 of FIG. 1A, can be applied to gas enclosures of various sizes and designs. Various embodiments of a gas enclosure assembly can have different frame members constructed to provide the contours of the gas enclosure assembly. Various embodiments of a gas enclosure assembly of the present teachings can accommodate an OLED printing system while optimizing the workspace to minimize inert gas volume and also allowing immediate external access to the OLED printing system during processing. In that regard, various gas enclosure assemblies of the present teachings can differ in their contoured topography and volume. As a non-limiting example, various embodiments of a contoured gas enclosure according to the present teachings can have a gas enclosure volume of about 6 m to about 95 m to accommodate various embodiments of a printing system capable of printing substrate sizes from Gen 3.5 to Gen 10. By way of further non-limiting example, various embodiments of a contoured gas enclosure according to the present teachings can have a gas enclosure volume of about 15 m to about 30 m to accommodate various embodiments of a printing system capable of printing, for example, Gen 5.5 to Gen 8.5 substrate sizes. Such embodiments of a contoured gas enclosure can provide a volume savings of about 30% to about 70% compared to a non-contoured enclosure having non-contoured dimensions of width, length, and height.

[0088] 9 can have all of the features described in the present teachings for the exemplary gas enclosure assembly 100 of FIG. 1A. For example, without limitation, the gas enclosure assembly 1000 can utilize sealing according to the present teachings to provide a sealed enclosure throughout construction and deconstruction cycles. Various embodiments of a gas enclosure system based on the gas enclosure assembly 1000 can have a gas purification system that can maintain various levels of various reactive species, including various reactive atmospheric gases such as water vapor and oxygen, and organic solvent vapors, at 100 ppm or less, e.g., 10 ppm or less, 1.0 ppm or less, or 0.1 ppm or less.

[0089] Additionally, as discussed in more detail later herein, various embodiments of gas enclosure systems, for example, but not limited to, based on gas enclosure assembly 100 of FIG. 1A and gas enclosure assembly 1000 of FIG. 9, can have circulation and filtration systems that can provide a laminar flow environment that can minimize turbulence and create a substantially low-particle environment by maintaining suspended particulate matter levels that meet International Standards Organization Standard (ISO) 14644-1:1999, as specified by Class 1 through Class 5. A determination of suspended particulate matter can be performed on various embodiments of the gas enclosure system before the printing process for system validation, for example, using a portable particle counting device. In various embodiments of the gas enclosure system, a determination of suspended particulate matter can be performed in situ while a substrate is being printed as an ongoing quality check. For various embodiments of the gas enclosure system, a determination of suspended particulate matter can be performed before a substrate is printed, as well as in situ while a substrate is being printed, for system validation.

[0090] Additionally, for various embodiments of the gas enclosure system of the present teachings, a substantially low particle environment can provide a substantially low particle substrate surface. Modeling based on various embodiments of the closure system suggests that, without the various particle control systems of the present teachings, deposition on the substrate per print cycle per square meter of substrate could be greater than about 1 million to greater than about 10 million particles for particles in the size range of 0.1 μm and larger. Such calculations suggest that, without the various particle control systems of the present teachings, deposition on the substrate per print cycle per square meter of substrate could be greater than about 1,000 to greater than about 10,000 particles for particles in the size range of about 2 μm and larger. Determination of the on-substrate distribution of particulate matter on the substrate can be performed on various embodiments of the gas enclosure system before a substrate is printed for system validation, for example, using a test substrate. In various embodiments of the gas enclosure system, determination of the on-substrate distribution of particulate matter can be performed in situ as an ongoing quality check while the substrate is being printed. For various embodiments of the gas enclosure system, determination of the on-substrate distribution of particulate matter can be performed before the substrate is printed, as well as in situ while the substrate is being printed, for system validation.

[0091] Various embodiments of the gas enclosure system can have a particle control system capable of maintaining a substantially low-particle environment, providing on-substrate particle specifications for particles from about 0.1 μm or larger to about 10 μm or larger. Various embodiments of the on-substrate particle specifications can be easily converted from an average on-substrate particle distribution per square meter of substrate per minute to an average on-substrate particle distribution per substrate per minute for each target particle size range. As previously discussed herein, such conversion can be easily performed, for example, through known relationships between substrates of a particular generation size and substrates of corresponding area for that substrate generation. Additionally, the average on-substrate particle distribution per square meter of substrate per minute can be easily converted to any of a variety of unit time representations. For example, in addition to converting between standard time units, e.g., seconds, minutes, and days, process-specific units of time can be used. For example, print cycles can be associated with units of time, as previously discussed herein.

[0092] Various embodiments of the low-particle gas enclosure system of the present teachings can maintain a low-particle environment that provides an average on-substrate particle distribution that meets an on-substrate deposition rate specification of less than or equal to about 100 particles per square meter of substrate per minute for particles greater than or equal to 10 μm in size. Various embodiments of the low-particle gas enclosure system of the present teachings can maintain a low-particle environment that provides an average on-substrate particle distribution that meets an on-substrate deposition rate specification of less than or equal to about 100 particles per square meter of substrate per minute for particles greater than or equal to 5 μm in size. Various embodiments of the gas enclosure system of the present teachings can maintain a low-particle environment that provides an average on-substrate particle distribution that meets an on-substrate deposition rate specification of less than or equal to about 100 particles per square meter of substrate per minute for particles greater than or equal to 2 μm in size. Various embodiments of the gas enclosure system of the present teachings can maintain a low particle environment that provides an average on-substrate particle distribution that meets an on-substrate deposition rate specification of less than about 100 particles per square meter of substrate per minute for particles greater than or equal to 1 μm in size. Various embodiments of the low-particle gas enclosure system of the present teachings can maintain a low-particle environment that provides an average on-substrate particle distribution that meets an on-substrate deposition rate specification of less than about 1000 particles per square meter of substrate per minute for particles greater than or equal to 0.5 μm in size. Various embodiments of the gas enclosure system of the present teachings can maintain a low-particle environment that provides an average on-substrate particle distribution that meets an on-substrate deposition rate specification of less than about 1000 particles per square meter of substrate per minute for particles greater than or equal to 0.3 μm in size. Various embodiments of the low-particle gas enclosure system of the present teachings can maintain a low-particle environment that provides an average on-substrate particle distribution that meets an on-substrate deposition rate specification of less than about 1000 particles per square meter of substrate per minute for particles greater than or equal to 0.1 μm in size. For large or equal particles, a low particle environment can be maintained that provides an average on-substrate particle distribution that meets an on-substrate deposition rate specification of less than or equal to about 1000 particles per square meter of substrate per minute.

[0093] 9 depicts a perspective view of a gas enclosure assembly 1000 according to various embodiments of the gas enclosure assembly of the present teachings. The gas enclosure assembly 1000 may include a front panel assembly 1200′, a center panel assembly 1300′, and a rear panel assembly 1400′. The front panel assembly 1200′ may include a front ceiling panel assembly 1260′, a front wall panel assembly 1240′ that may have an opening 1242 for receiving a substrate, and a front foundation panel assembly 1220′. The rear panel assembly 1400′ may include a rear ceiling panel assembly 1460′, a rear wall panel assembly 1440′, and a rear foundation panel assembly 1420′. The center panel assembly 1300′ may include a first center enclosure panel assembly 1340′, a center wall and ceiling panel assembly 1360′, and a second center enclosure panel assembly 1380′, as well as a center foundation panel assembly 1320′.

[0094] Additionally, central panel assembly 1300′ can include a first printhead management system auxiliary panel assembly 1330′ as well as a second printhead management system auxiliary panel assembly (not shown). As previously discussed herein, various embodiments of auxiliary enclosures constructed as part of the gas enclosure assembly can be sealably isolated from the working volume of the gas enclosure system. For example, such physical isolation of the auxiliary enclosure from the printing system enclosure can allow various procedures, such as, but not limited to, various maintenance procedures on the printhead assembly, to be performed with little or no interruption to the printing process, thereby minimizing or eliminating downtime of the gas enclosure system.

[0095] 10A , gas enclosure assembly 1000 can include front, center, and rear foundation panel assemblies 1220′, 1320′, and 1420′, which, when fully constructed, form a contiguous base or pan upon which OLED printing system 2000 can be placed. Similarly as described for gas enclosure assembly 100 of FIG. 1A , the various frame members and panels comprising front, center, and rear panel assemblies 1200′, 1300′, and 1400′ of gas enclosure assembly 1000 can be joined around OLED printing system 2000 to form a printing system enclosure. Thus, fully constructed gas enclosure assemblies, such as gas enclosure assembly 1000, when integrated with various environmental control systems, can form various embodiments of gas enclosure systems, including various embodiments of OLED printing system 2000. According to various embodiments of the gas enclosure system of the present teachings as previously described, environmental control of the interior volume defined by the gas enclosure assembly can include control of lighting, for example, through the number and placement of lights of specific wavelengths, control of particulate matter using various embodiments of a particle control system, control of reactive gas species using various embodiments of a gas purification system, and temperature control of the gas enclosure assembly using various embodiments of a thermal control system.

[0096] An OLED inkjet printing system, such as the OLED printing system 2000 of Figure 10A, shown in expanded view in Figure 10B, can be comprised of several devices and apparatuses that enable reliable placement of ink droplets onto specific locations on a substrate. These devices and apparatuses can include, but are not limited to, a printhead assembly, an ink delivery system, a motion system that provides relative motion between the printhead assembly and the substrate, a substrate support apparatus, a substrate loading and unloading system, and a printhead management system.

[0097] The printhead assembly can include at least one inkjet head with at least one orifice capable of ejecting ink droplets at a controlled rate, velocity, and size. The inkjet head is fed by an ink supply system, which provides ink to the inkjet head. As shown in the enlarged view of FIG. 10B , the OLED inkjet printing system 2000 can have a substrate, such as substrate 2050, that can be supported by a substrate support device, such as a chuck, for example, but not limited to, a vacuum chuck, a substrate floating chuck with pressure ports, and a substrate floating chuck with vacuum and pressure ports. In various embodiments of the systems and methods of the present teachings, the substrate support device can be a substrate floating table. As discussed in more detail later herein, the substrate floating table 2200 of FIG. 10B can be used to support the substrate 2050 and can be part of a substrate transport system that, in conjunction with a Y-axis motion system, provides frictionless transport of the substrate 2050. The Y-axis motion system of the present teachings can include a first Y-axis track 2351 and a second Y-axis track 2352, which can include a gripper system (not shown) for holding the substrate. The Y-axis motion can be provided by either a linear air bearing or a linear mechanical system. The substrate floating table 2200 of the OLED inkjet printing system 2000 shown in Figures 10A and 10B can define the movement of the substrate 2050 through the gas enclosure assembly 1000 of Figure 9 during the printing process.

[0098] Printing requires relative motion between the printhead assembly and the substrate. This is achieved using a motion system, typically a gantry or split-axis XYZ system. Either the printhead assembly can move over a stationary substrate (gantry-type), or in the case of a split-axis configuration, both the printhead and the substrate can move. In another embodiment, the printhead assembly can be substantially stationary, e.g., in the X and Y axes, while the substrate can move in the X and Y axes relative to the printhead, with Z-axis motion provided either by a substrate support device or by a Z-axis motion system associated with the printhead assembly. As the printhead moves relative to the substrate, ink droplets are ejected at the correct time to be deposited at the desired location on the substrate. Substrate loading and unloading systems can be used to insert and remove substrates from the printer. Depending on the printer configuration, this can be achieved using a mechanical conveyor, a substrate floating table with a transport assembly, or a substrate transfer robot with an end effector. The printhead management system can be composed of several subsystems that enable measurement tasks such as checking nozzle firing and measuring drop volume, velocity, and trajectory from all nozzles in a printhead, as well as maintenance tasks such as wiping or blotting excess ink from inkjet nozzle faces, priming and cleaning the printhead by draining ink from the ink supply through the printhead into a waste bowl, and replacing the printhead. Given the various components that can comprise an OLED printing system, various embodiments of the OLED printing system can have different footprints and form factors.

[0099] 10B , printing system base 2100 can include a first riser (not visible) and a second riser 2122 on which bridge 2130 is mounted. For various embodiments of OLED printing system 2000, bridge 2130 can support first X-axis carriage assembly 2301 and second X-axis carriage assembly 2302, which can control the movement of first printhead assembly 2501 and second printhead assembly 2502, respectively, across bridge 2130. For various embodiments of printing system 2000, first X-axis carriage assembly 2301 and second X-axis carriage assembly 2302 can utilize a linear air-bearing motion system that is inherently low particle generating. According to various embodiments of the printing system of the present teachings, the X-axis carriage can have a Z-axis movement plate mounted thereon. 10B, first X-axis carriage assembly 2301 is depicted with first Z-axis moving plate 2310, while second X-axis carriage assembly 2302 is depicted with second Z-axis moving plate 2312. While FIG. 10B depicts two carriage assemblies and two printhead assemblies, there can be a single carriage assembly and a single printhead assembly for various embodiments of OLED inkjet printing system 2000. For example, either first printhead assembly 2501 or second printhead assembly 2502 can be mounted on an X, Z-axis carriage assembly, while a camera system for inspecting features of substrate 2050 can be mounted on the second X, Z-axis carriage assembly. Various embodiments of the OLED inkjet printing system 2000 can have a single printhead assembly, for example, either the first printhead assembly 2501 or the second printhead assembly 2502 can be mounted on an X, Z-axis carriage assembly, while a UV lamp for curing the encapsulation layer printed on the substrate 2050 can be mounted on the second X, Z-axis carriage assembly.For various embodiments of the OLED inkjet printing system 2000, there may be a single printhead assembly, for example, either a first printhead assembly 2501 and a second printhead assembly 2502 mounted on an X, Z axis carriage assembly, while a heat source for curing the encapsulation layer printed on the substrate 2050 may be mounted on the second carriage assembly.

[0100] 10B , a first X,Z-axis carriage assembly 2301 can be used to position a first printhead assembly 2501, which can be mounted on a first Z-axis motion plate 2310, over a substrate 2050, which is shown supported on a substrate floating table 2200. A second X,Z-axis carriage assembly 2302 with a second Z-axis motion plate 2312 can similarly be configured to control the XZ-axis motion of the second printhead assembly 2502 relative to the substrate 2050. Each printhead assembly, such as the first printhead assembly 2501 and the second printhead assembly 2502 in FIG. 10B , can have multiple printheads mounted in at least one printhead device, as depicted in the partial view of the first printhead assembly 2501, which depicts multiple printheads 2505. A printhead device can include, for example, but not limited to, fluid and 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 various embodiments of the printing system 2000, a printhead assembly can include from about 1 to about 60 printhead devices, each printhead device can have from about 1 to about 30 printheads within it. A printhead, e.g., an industrial inkjet head, can have from about 16 to about 2048 nozzles capable of ejecting droplet volumes from about 0.1 pL to about 200 pL.

[0101] According to various embodiments of the gas enclosure system of the present teachings, given the large number of printhead devices and printheads, first printhead management system 2701 and second printhead management system 2702 can be housed in an auxiliary enclosure that can be isolated from the printing system enclosure during the printing process to perform various measurement and maintenance tasks with little or no interruption to the printing process. As can be seen in FIG. 10B , first printhead assembly 2501 can be seen positioned relative to first printhead management system 2701 for immediate implementation of various measurement and maintenance procedures that can be performed by first printhead management system devices 2707, 2709, and 2711. Devices 2707, 2709, and 2711 can be any of various subsystems or modules for performing various printhead management functions. For example, devices 2707, 2709, and 2711 can be any of a drop measurement module, a printhead replacement module, a purge bowl module, and a blotter module.

[0102] FIG. 10C depicts an expanded view of a first printhead management system 2701 housed within a first printhead management system auxiliary panel assembly 1330′ according to various embodiments of the gas enclosure assembly and system of the present teachings. As depicted in FIG. 10C, the auxiliary panel assembly 1330′ is shown in a cutaway view to more clearly reveal the details of the first printhead management system 2701. Various embodiments of printhead management systems according to the present teachings, such as the first printhead management system 2701, devices 2707, 2709, and 2011 in FIG. 10C, can be various subsystems or modules for performing various functions. For example, devices 2707, 2709, and 2011 can be a drop measurement module, a printhead purge bowl module, and a blotter module. As depicted in FIG. 10C, a printhead replacement module 2713 can provide a location for docking at least one printhead device 2505. In various embodiments of the first printhead management system 2701, the first printhead management system auxiliary panel assembly 1330′ can be maintained in the same environment in which the gas enclosure assembly 1000 (see FIG. 19 ) is maintained. The first printhead management system auxiliary panel assembly 1330′ can have handlers 2530 positioned to perform tasks associated with various printhead management procedures. For example, each subsystem can have various parts that are consumable in nature and require replacement, such as replacing blotter paper, ink, and waste reservoirs. The various consumable parts can be packaged for immediate insertion, for example, in a fully automated mode using the handler. As a non-limiting example, blotter paper can be packaged in a cartridge format that can be easily inserted into the blotting module for use. As another non-limiting example, ink can be packaged in a replaceable reservoir as well as a cartridge format for use in the printing system. Various embodiments of the waste reservoir can be packaged in a cartridge format that can be easily inserted into the purge bowl module for use.Additionally, parts of various components of the printing system that are subject to continuous use may require periodic replacement. Convenient management of the printhead assembly, such as, but not limited to, printhead device or printhead replacement, may be desirable during the printing process. A printhead replacement module can have parts, such as printhead devices or printheads, that can be easily inserted into the printhead assembly for use. A drop measurement system used to check nozzle firing and measure drop volume, velocity, and trajectory from all nozzles based on optical detection can have sources and detectors that may require periodic replacement after use. Various consumable, high-use parts can be packaged for immediate insertion, for example, in a fully automated mode using a handler. The handler 2530 can have an end effector 2536 mounted on an arm 2534. Various embodiments of end effector configurations can be used, for example, blade-type end effectors, clamp-type end effectors, and gripper-type end effectors. Various embodiments of the end effector can include mechanical gripping and clamping, as well as pneumatic or vacuum assisted assemblies to either actuate portions of the end effector or otherwise hold the printhead device or a printhead from the printhead device.

[0103] With respect to printhead device or printhead placement, the printhead replacement module 2713 of the printhead management system 2701 of FIG. 10C can include a docking station for a printhead device having at least one printhead, as well as a storage container for the printhead. Because each printhead assembly (see FIG. 10B) can include from about 1 to about 60 printhead devices, and because each printhead device can have from about 1 to about 30 printheads, various embodiments of the printing system of the present teachings can then have from about 1 to about 1,800 printheads. In various embodiments of the printhead replacement module 2713, while the printhead device is docked, each printhead mounted on the printhead device can remain operational while not being used by the printing system. For example, when placed in the docking station, each printhead on each printhead device can be connected to an ink supply and electrical connections. Power can be provided to each printhead on each printhead device so that periodic firing pulses can be applied to each nozzle of each printhead while docked to ensure the nozzles remain primed and do not clog. The handler 2530 in FIG. 10C can be positioned proximate to the printhead assembly 2500. The printhead assembly 2500 can be docked over the first printhead management system auxiliary panel assembly 1330′, as depicted in FIG. 10C. During a procedure for replacing a printhead, the handler 2530 can remove a target component, either a printhead or a printhead device having at least one printhead, from the printhead assembly 2500. The handler 2530 can retrieve a replacement component, such as a printhead device or printhead, from the printhead replacement module 2713 to complete the replacement process. The removed component can be placed in the printhead replacement module 2713 for retrieval.

[0104] Reference is again made to FIG. 10A for various embodiments of a gas enclosure assembly having an auxiliary enclosure that can be closed off and sealably isolated from a first working volume, e.g., a printing system enclosure. As depicted in FIG. 10B, there can be four isolators above OLED printing system 2000: a first set of isolators 2110 (a second not shown on the opposite side) and a second set of isolators 2112 (a second not shown on the opposite side) that support substrate floating table 2200 of OLED printing system 2000. For gas enclosure assembly 1000 of FIG. 10A, first set of isolators 2110 and second set of isolators 2112 can be mounted within respective isolator wall panels, such as first isolator wall panel 1325′ and second isolator wall panel 1327′ of central foundation panel assembly 1320′. For the gas enclosure assembly 1000 of FIG. 10A , the central base assembly 1320′ can include a first printhead management system auxiliary panel assembly 1330′ as well as a second printhead management system auxiliary panel assembly 1370′. FIG. 10A of the gas enclosure assembly 1000 depicts the first printhead management system auxiliary panel assembly 1330′, which can include a first rear wall panel assembly 1338′. Similarly, the second printhead management system auxiliary panel assembly 1370′, which can include a second rear wall panel assembly 1378′, is also depicted. The first rear wall panel assembly 1338′ of the first printhead management system auxiliary panel assembly 1330′ can be similarly constructed as shown for the second rear wall panel assembly 1378′. The second back wall panel assembly 1378′ of the second printhead management system auxiliary panel assembly 1370′ comprises a second back wall frame assembly 1378 having a second seal support panel 1375 sealably mounted to the second back wall frame assembly 1378. The second seal support panel 1375 can have a second passage 1365 proximal to a second end (not shown) of the base 2100. A second seal 1367 can be mounted on the second seal support panel 1375 around the second passage 1365. A first seal can similarly be positioned and mounted around the first passage for the first printhead management system auxiliary panel assembly 1330′. Each passage in the auxiliary panel assembly 1330′ and the auxiliary panel assembly 1370′ can accommodate passage of a respective maintenance system platform, such as the first and second maintenance system platforms 2703 and 2704 of FIG. 10B , through the passage. As discussed in more detail later herein, passages, such as the second passage 1365 of FIG. 10A , must be sealable to sealably isolate the auxiliary panel assembly 1330′ and the auxiliary panel assembly 1370′. It is contemplated that various seals, such as inflatable seals, bellows seals, and lip seals, can be used to seal passageways, such as second passageway 1365 in FIG. 10A, around a maintenance platform affixed to the printing system base.

[0105] The first printhead management system auxiliary panel assembly 1330′ and the second printhead management system auxiliary panel assembly 1370′ can each include a first printhead assembly opening 1342 in a first floor panel assembly 1341′ and a second printhead assembly opening 1382 in a second floor panel assembly 1381′. The first floor panel assembly 1341′ is depicted in FIG. 10A as part of the first central enclosure panel assembly 1340′ of the central panel assembly 1300′. The first floor panel assembly 1341′ is a panel assembly common to both the first central enclosure panel assembly 1340′ and the first printhead management system auxiliary panel assembly 1330′. The second floor panel assembly 1381′ is depicted in FIG. 10A as part of the second central enclosure panel assembly 1380′ of the central panel assembly 1300′. The second floor panel assembly 1381' is a panel assembly that is common to both the second central enclosure panel assembly 1380' and the second printhead management system auxiliary panel assembly 1370'.

[0106] As previously discussed herein, the first printhead assembly 2501 can be housed in a first printhead assembly enclosure 2503, and the second printhead assembly 2502 can be housed in a second printhead assembly enclosure 2504. According to the systems and methods of the present teachings, the first printhead assembly enclosure 2503 and the second printhead assembly enclosure 2504 can have openings at their bottoms, which can have perimeters (not shown), so that the various printhead assemblies can be positioned for printing during the printing process. Additionally, the portions of the first printhead assembly enclosure 2503 and the second printhead assembly enclosure 2504 that form the housing can be constructed as previously described for the various panel assemblies, so that the frame assembly members and panels can provide a sealed enclosure.

[0107] Compressible gaskets, such as those previously described for sealing the various frame members, can be affixed around the first printhead assembly opening 1342 and the second printhead assembly opening 1382, respectively, or alternatively around the peripheries of the first printhead assembly enclosure 2503 and the second printhead assembly enclosure 2504.

[0108] As depicted in FIG. 10A, the first printhead assembly docking gasket 1345 and second printhead assembly docking gasket 1385 can be affixed around the first printhead assembly opening 1342 and second printhead assembly opening 1382, respectively. During various printhead measurement and maintenance procedures, first printhead assembly 2501 and second printhead assembly 2502 can be positioned over the first printhead assembly opening 1342 in first floor panel assembly 1341′ and the second printhead assembly opening 1382 in second floor panel assembly 1381′, respectively, by first X,Z-axis carriage assembly 2301 and second X,Z-axis carriage assembly 2302. In that regard, for various printhead measurement and maintenance procedures, the first printhead assembly 2501 and the second printhead assembly 2502 can be positioned over the first printhead assembly opening 1342 of the first floor panel assembly 1341′ and the second printhead assembly opening 1382 of the second floor panel assembly 1381′ without covering or sealing the first printhead assembly opening 1342 and the second printhead assembly opening 1382. The first X, Z-axis carriage assembly 2301 and the second X, Z-axis carriage assembly 2302 can dock the first printhead assembly enclosure 2503 and the second printhead assembly enclosure 2504, respectively, with the first printhead management system auxiliary panel assembly 1330′ and the second printhead management system auxiliary panel assembly 1370′, respectively. In various printhead measurement and maintenance procedures, such docking may effectively close first printhead assembly opening 1342 and second printhead assembly opening 1382 without having to seal first printhead assembly opening 1342 and second printhead assembly opening 1382.For various printhead measurement and maintenance procedures, docking can include forming a gasket seal between the printhead assembly enclosure and the printhead management system panel assembly, respectively. When first printhead assembly enclosure 2503 and second printhead assembly enclosure 2504 are docked with first printhead management system auxiliary panel assembly 1330′ and second printhead management system auxiliary panel assembly 1370′, the composite structure so formed is sealed to sealably close first printhead assembly opening 1342 and second printhead assembly opening 1382, in conjunction with sealably closing passages such as second passage 1365 and the complementary first passage in FIG. 10A .

[0109] Additionally, according to the present teachings, the auxiliary enclosure can be isolated from another internal enclosure volume, such as a printing system enclosure, as well as from the exterior of the gas enclosure assembly, by using a structural closure to sealably close passages, such as the first printhead assembly opening 1342 and the second printhead assembly opening 1382 in FIG. 10A . According to the present teachings, the structural closure can include various sealable covers for openings or passages, including, by way of non-limiting example, enclosure panel openings or passages. According to the systems and methods of the present teachings, a gate can be any structural closure that can be used to reversibly cover or reversibly sealably close any opening or passage using pneumatic, hydraulic, electrical, or manual actuation. Thus, a gate can be used to reversibly cover or reversibly sealably close the first printhead assembly opening 1342 and the second printhead assembly opening 1382 in FIG. 10A .

[0110] In the expanded view of OLED printing system 2000 in Figure 10B, various embodiments of the printing system can include a substrate floating table 2200 supported by a substrate floating table base 2220. The substrate floating table base 2220 can be mounted on the printing system base 2100. The substrate 2050 may be mounted on the substrate floating table 2200 of the OLED printing system. The substrate floating table 2200 of the OLED printing system may support the substrate 2050 and define a motion that may move the substrate 2050 through the gas enclosure assembly 1000 during printing of the OLED substrate. The Y-axis motion system of the present teachings may include a first Y-axis track 2351 and a second Y-axis track 2352, which may include a gripper system (not shown) for holding the substrate. The Y-axis motion may be provided by either a linear air bearing or a linear mechanical system. In that regard, the substrate floating table 2200 in conjunction with the motion system, i.e., the Y-axis motion system as depicted in FIG. 10B , may provide frictionless transport of the substrate 2050 through the printing system.

[0111] FIG. 11 depicts a floating table according to various embodiments of the present teachings for frictionless support and stable transport of a load, such as substrate 2050 in FIG. 10B , in conjunction with a transport system. Various embodiments of the floating table can be used with any of various embodiments of the gas enclosure system of the present teachings. As previously discussed, various embodiments of the gas enclosure system of the present teachings can process a range of OLED flat panel display substrate sizes, from smaller Gen 3.5 substrates having dimensions of approximately 61 cm x 72 cm, as well as a range of larger generation sizes. It is contemplated that various embodiments of the gas enclosure system can process Gen 5.5 substrate sizes having dimensions of approximately 130 cm x 150 cm, as well as Gen 7.5 substrates having dimensions of approximately 195 cm x 225 cm, and can be cut into eight 42-inch or six 47-inch flat panels per substrate, as well as larger panels. A Gen 8.5 substrate is approximately 220 cm by 250 cm and can be cut into six 55-inch or eight 46-inch flat panels per substrate. However, substrate generation sizes continue to advance, such that currently available Gen 10 substrates, which have dimensions of approximately 285 cm by 305 cm, are not considered the final generation of substrate sizes. In addition, the sizes described, derived from the terminology used for glass-based substrates, can apply to substrates of any material suitable for use in OLED printing. For various embodiments of the OLED inkjet printing system, various substrate materials can be used for the substrate 2050, including, but not limited to, various glass substrate materials and various polymer substrate materials. Accordingly, there are various substrate sizes and materials that require stable transport during printing in various embodiments of the gas enclosure system of the present teachings.

[0112] As depicted in FIG. 11 , a substrate floating table 2200 according to various embodiments of the present teachings can have a floating table base 2220 for supporting multiple floating table zones. The substrate floating table 2200 can have a zone 2210 to which both pressure and vacuum can be applied through multiple ports. Such a zone with both pressure and vacuum control can effectively provide a fluid spring between the zone 2210 and the substrate (not shown). The zone 2210 with both pressure and vacuum control is a fluid spring with bidirectional stiffness. The gap that exists between the load and the floating table surface is referred to as the fly height. A zone such as zone 2210 of the substrate floating table 2200 of FIG. 11 , where multiple pressure and vacuum ports are used to create a fluid spring with bidirectional stiffness, can provide a controllable fly height for a load such as a substrate.

[0113] Proximal to zone 2210 are first and second transition zones 2211 and 2212, respectively, and then proximal to first and second transition zones 2211 and 2212 are pressure-only zones 2213 and 2214, respectively. In the transition zones, the pressure ratio to the vacuum nozzles gradually increases toward the pressure-only zone to provide a gradual transition from zone 2210 to zones 2213 and 2214. For various embodiments of the substrate floating table, such as depicted in FIG. 11, pressure-only zones 2213 and 2214 are depicted as comprising rail structures. For various embodiments of the substrate floating table, pressure-only zones such as pressure-only zones 2213 and 2214 in FIG. 11 can comprise continuous plates, such as those depicted for pressure-vacuum zone 2210 in FIG. 11.

[0114] For various embodiments of a floating table such as that depicted in FIG. 11 , there may be essentially uniform heights between the pressure-vacuum zone, transition zone, and pressure-only zone, so that the three zones lie essentially in one plane and may vary in length, within tolerances. For example, without limitation, to provide a sense of scale and proportion, for various embodiments of a floating table of the present teachings, the pressure-only zone may be approximately 2.5 m, and the pressure-vacuum zone may be approximately 800 mm, while the transition zone may be approximately 400 mm. In FIG. 11 , pressure-only zones 2213 and 2214 do not provide fluid springs with bidirectional stiffness and therefore do not provide the control that zone 2210 can provide. Therefore, to allow sufficient height so that the load does not collide with the floating table within the pressure-only zone, the fly height of the load may typically be greater across the pressure-only zone than the fly height of the substrate across the pressure-vacuum zone. For example, and without limitation, it may be desirable to process the OLED panel substrate to have a jump height of about 150 μm to about 300 μm above a pressure-only zone, such as zones 2213 and 2214, and then about 30 μm to about 50 μm above a pressure-vacuum zone, such as zone 2210.

[0115] Various embodiments of the gas enclosure system of the present teachings can utilize various devices, apparatuses, and systems in addition to the gas circulation and filtration system to maintain a controlled gas enclosure environment. For example, in addition to the gas circulation and filtration system to provide thorough and complete conversion of gases within the gas enclosure, a thermal conditioning system utilizing multiple heat exchangers can be provided to maintain a desired temperature within the gas enclosure. For example, multiple heat exchangers can be provided operating with, adjacent to, or used in conjunction with a fan or another gas circulation device. A gas purification loop can be configured to circulate gas from within the gas enclosure assembly through at least one gas purification component external to the enclosure. In that regard, the circulation and filtration system internal to the gas enclosure assembly in conjunction with the gas purification loop external to the gas enclosure assembly can provide continuous circulation of a substantially low-particulate inert gas with substantially low levels of reactive species throughout the gas enclosure system. According to the present teachings, an inert gas can be any gas that does not undergo chemical reaction under a defined set of conditions. Some commonly used, non-limiting examples of inert gases can include nitrogen, any of the noble gases, and any combination thereof. Various embodiments of the gas enclosure system with a gas purification system can be configured to maintain very low levels of undesirable components, such as organic solvents and their vapors, as well as water, water vapor, oxygen, and the like. Such embodiments of the gas enclosure system can maintain various levels of various reactive species, including various reactive atmospheric gases such as water vapor and oxygen, and organic solvent vapors, at 100 ppm or less, e.g., 10 ppm or less, 1.0 ppm or less, or 0.1 ppm or less.

[0116] FIG. 12 is a schematic diagram illustrating a gas enclosure system 501. Various embodiments of the gas enclosure system 501 according to the present teachings can include a gas enclosure assembly 1101 for housing a printing system, a gas purification loop 3130 in fluid communication with the gas enclosure assembly 1101, and at least one thermal conditioning system 3140. Additionally, various embodiments of the gas enclosure system 501 can have a pressurized inert gas recirculation system 3000 that can supply inert gas for operating various devices, such as a substrate floating table for an OLED printing system. Various embodiments of the pressurized inert gas recirculation system 3000 can utilize a compressor, a blower, or a combination of the two as a source of gas for various embodiments of the pressurized inert gas recirculation system 3000, as discussed in more detail later herein. Additionally, the gas enclosure system 501 can have a circulation and filtration system internal to the gas enclosure system 501 (not shown).

[0117] 12 , for various embodiments of a gas enclosure assembly according to the present teachings, the piping design can separate the inert gas circulated through the gas purification loop 3130 from the inert gas continuously filtered and circulated internally for various embodiments of the gas enclosure assembly. The gas purification loop 3130 includes an outlet line 3131 from the gas enclosure assembly 1101 to the solvent removal component 3132 and then to the gas purification system 3134. The inert gas, purified of solvent and other reactive gas species such as oxygen and water vapor, is then returned to the gas enclosure assembly 1101 through the inlet line 3133. The gas purification loop 3130 may also include appropriate ducts and connections, as well as sensors, e.g., oxygen, water vapor, and solvent vapor sensors. Gas circulation units, such as fans, blowers, or motors, and the like, can be provided separately or incorporated into the gas purification system 3134, for example, to circulate gas through the gas purification loop 3130. According to various embodiments of the gas enclosure assembly, although the solvent removal system 3132 and the gas purification system 3134 are shown as separate units in the schematic diagram shown in FIG. 12, the solvent removal system 3132 and the gas purification system 3134 can be housed together as a single purification unit.

[0118] The gas purification loop 3130 of FIG. 12 can have a solvent removal system 3132 located upstream of the gas purification system 3134, such that the inert gas circulated from the gas enclosure assembly 1101 passes through the solvent removal system 3132 via outlet line 3131. According to various embodiments, the solvent removal system 3132 can be a solvent containment system based on adsorbing solvent vapor from the inert gas passing through the solvent removal system 3132 of FIG. 12. For example, one or more adsorbent layers, such as, but not limited to, activated carbon, molecular sieves, and the like, can effectively remove a wide variety of organic solvent vapors. For various embodiments of the gas enclosure system, cold trap technology can be employed to remove solvent vapor within the solvent removal system 3132. As previously discussed herein, for various embodiments of the gas enclosure assembly according to the present teachings, sensors, such as oxygen, water vapor, and solvent vapor sensors, can be used to monitor the effective removal of such species from the inert gas continuously circulating through a gas enclosure system, such as the gas enclosure system 501 of FIG. 12. Various embodiments of the solvent removal system can indicate when adsorbents, such as activated carbon, molecular sieves, and the like, have reached capacity so that one or more adsorbent layers can be regenerated or replaced. Regeneration of molecular sieves can involve heating the molecular sieve, contacting the molecular sieve with forming gas, combinations thereof, and the like. Molecular sieves configured to trap various species, including oxygen, water vapor, and solvents, can be regenerated by heating and exposing them to forming gas containing hydrogen, for example, forming gas containing about 96% nitrogen and 4% hydrogen, the proportions being by volume or weight. Physical regeneration of activated carbon can be performed using similar heating procedures in an inert environment.

[0119] Any suitable gas purification system can be used for the gas purification system 3134 of the gas purification loop 3130 of FIG. 12 . For example, gas purification systems available from MBRAUN Inc. (Statham, New Hampshire) or Innovative Technology (Amesbury, Massachusetts) may be useful for incorporation into various embodiments of a gas enclosure assembly according to the present teachings. The gas purification system 3134 can be used to purify one or more inert gases within the gas enclosure system 501, for example, to purify the entire gas atmosphere within the gas enclosure assembly. As mentioned above, the gas purification system 3134 can include a gas circulation unit, such as a fan, blower, or motor, and the like, to circulate gas through the gas purification loop 3130. In that regard, the gas purification system can be selected depending on the volume of the enclosure, which can define the volumetric flow rate for moving the inert gas through the gas purification system. For various embodiments of gas enclosure systems having gas enclosure assemblies with volumes up to about 4 m3, a gas purification system capable of moving at about 84 m3 / hour can be used. For various embodiments of gas enclosure systems having gas enclosure assemblies with volumes up to about 10 m3, a gas purification system capable of moving at about 155 m3 / hour can be used. For various embodiments of gas enclosure assemblies having volumes between about 52 and 114 m3, more than one gas purification system may be used.

[0120] Any suitable gas filter or purification device can be included in the gas purification system 3134 of the present teachings. In some embodiments, the gas purification system can include two parallel purification devices so that one of the devices can be taken off-line for maintenance and the other device can be used to continue system operation without interruption. In some embodiments, for example, the gas purification system can include one or more molecular sieves. In some embodiments, the gas purification system can include at least a first molecular sieve and a second molecular sieve so that when one of the molecular sieves becomes saturated with impurities or is otherwise deemed not 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 operation of different molecular sieves, to regenerate one or more molecular sieves, or a combination thereof. As previously discussed herein, molecular sieves may be regenerated and reused.

[0121] The thermal conditioning system 3140 of FIG. 12 can include at least one cooling device 3142 having a fluid outlet line 3141 for circulating coolant into the gas enclosure assembly and a fluid inlet line 3143 for returning the coolant to the cooling device. At least one fluid cooling device 3142 can be provided to cool the gas atmosphere within the gas enclosure system 501. For various embodiments of the gas enclosure system of the present teachings, the fluid cooling device 3142 delivers cooled fluid to a heat exchanger within the enclosure, where an inert gas is passed to a filtration system internal to the enclosure. At least one fluid cooling device can also be provided in the gas enclosure system 501 to cool heat generated from devices enclosed within the gas enclosure system 501. For example, without limitation, at least one fluid cooling device can also be provided in the gas enclosure system 501 to cool heat generated from an OLED printing system. The thermal conditioning system 3140 can comprise a heat exchanger or Peltier device and can have various cooling capacities. For example, for various embodiments of the gas enclosure system, the cooling device can provide a cooling capacity of about 2 kW to about 20 kW. Various embodiments of the gas enclosure system can have multiple fluid cooling devices capable of cooling one or more fluids. In some embodiments, the fluid cooling device can utilize several fluids as coolants, such as, but not limited to, water, antifreeze, refrigerant, and combinations thereof as heat exchange fluids. Appropriate leak-proof locking connections can be used when connecting associated conduits and system components.

[0122] As previously discussed, the present teachings disclose various embodiments of a gas enclosure system that can include a printing system enclosure defining a first volume and an auxiliary enclosure defining a second volume. Various embodiments of the gas enclosure system can have the auxiliary enclosure sealably constructed as a section of the gas enclosure assembly. According to the systems and methods of the present teachings, the auxiliary enclosure can be sealably isolated from the printing system enclosure and open to an environment external to the gas enclosure assembly without exposing the printing system enclosure to the external environment. For example, but not limited to, such physical isolation of the auxiliary enclosure for performing various printhead maintenance procedures can be performed to eliminate or minimize exposure of the printing system enclosure to contaminants such as air and water vapor and various organic vapors, as well as particulate contamination. Various printhead maintenance procedures, which can include measurement and maintenance procedures on the printhead assembly, can be performed with little or no interruption to the printing process, thereby minimizing or eliminating downtime of the gas enclosure system.

[0123] For various embodiments of the systems and methods of the present teachings, the auxiliary enclosure can be less than or equal to about 1% of the enclosure volume of the gas enclosure system. In various embodiments of the systems and methods of the present teachings, the auxiliary enclosure can be less than or equal to about 2% of the enclosure volume of the gas enclosure system. For various embodiments of the systems and methods of the present teachings, the auxiliary enclosure can be less than or equal to about 5% of the enclosure volume of the gas enclosure system. In various embodiments of the systems and methods of the present teachings, the auxiliary enclosure can be less than or equal to about 10% of the enclosure volume of the gas enclosure system. In various embodiments of the systems and methods of the present teachings, the auxiliary enclosure can be less than or equal to about 20% of the enclosure volume of the gas enclosure system. For example, when opening the auxiliary enclosure to an ambient environment containing reactive gases to perform a maintenance procedure is indicated, isolating the auxiliary enclosure from the working volume of the gas enclosure can prevent contamination of the entire volume of the gas enclosure. Furthermore, given the relatively small volume of the auxiliary enclosure, as compared to the printing system enclosure portion of the gas enclosure, the recovery time of the auxiliary enclosure may take significantly less time than the recovery time of the entire printing system enclosure.

[0124] For gas enclosure systems having a printing system enclosure defining a first volume and an auxiliary enclosure defining a second volume, both volumes can be readily integrated with gas circulation, filtration, and purification components to form a gas enclosure system capable of sustaining an inert, substantially low-particle environment for processes requiring such an environment with little or no interruption to the printing process. According to various systems and methods of the present teachings, the printing system enclosure may be introduced to a level of contamination low enough to allow the purification system to remove the contamination before it can affect the printing process. Various embodiments of the auxiliary enclosure may be of a volume substantially smaller than the total volume of the gas enclosure assembly and can rapidly restore an inert, low-particle environment after exposure to the external environment, thereby readily integrated with gas circulation, filtration, and purification components to form an auxiliary enclosure system that provides little or no interruption to the printing process.

[0125] In accordance with the systems and methods of the present teachings, various embodiments of printing system enclosures and auxiliary enclosures constructed as sections of a gas enclosure assembly can be constructed in a manner that provides separately housed frame member assembly sections. As a non-limiting example, gas enclosure systems 500 and 501 are disclosed. In addition to having all elements, the gas enclosure system 502 of Figure 13 can have a first gas enclosure assembly section 1101-S1 of the gas enclosure assembly 1101, which defines a first volume, and a second gas enclosure assembly section 1101-S2 of the gas enclosure assembly 1101, which defines a second volume. When all valves V1, V2, V3, and V4 are open, the gas purification loop 3130 operates essentially as previously described for the gas enclosure assembly and system 1101 of Figure 12. With V3 and V4 closed, only the first gas enclosure assembly section 1101-S1 is in fluid communication with the gas purification loop 3130. This valve state may be used, for example, but not limited to, when the second gas enclosure assembly segment 1101-S2 is sealably closed and thereby isolated from the first gas enclosure assembly segment 1101-S1 during various measurement and maintenance procedures that require the second gas enclosure assembly segment 1101-S2 to be open to atmosphere. With V1 and V2 closed, only the second gas enclosure assembly segment 1101-S2 is in fluid communication with the gas purification loop 3130. This valve state may be used, for example, but not limited to, during recovery of the second gas enclosure assembly segment 1101-S2 after the segment has been opened to atmosphere. As previously discussed with respect to the present teachings in connection with FIG. 12 , the requirements for the gas purification loop 3130 are specified with respect to the total volume of the gas enclosure assembly 1101. Therefore, recovery time can be substantially reduced by dedicating gas purification system resources to recovering a gas enclosure assembly section, such as the second gas enclosure assembly section 1101-S2, which is depicted for gas enclosure system 502 in FIG. 13 as having a volume significantly smaller than the total volume of gas enclosure 1101.

[0126] Additionally, various embodiments of the auxiliary enclosure can be easily integrated with a dedicated suite of environmental conditioning system components, such as lighting, gas circulation and filtration, gas purification, and thermostatic control components. In that regard, various embodiments of the gas enclosure system, including the auxiliary enclosure, which can be sealably isolated as part of the gas enclosure assembly, can have a controlled environment that is configured to be uniform with the first volume defined by the gas enclosure assembly that houses the printing system. Furthermore, various embodiments of the gas enclosure system, including the auxiliary enclosure, which can be sealably isolated as part of the gas enclosure assembly, can have a controlled environment that is configured to be different from the controlled environment of the first volume defined by the gas enclosure assembly that houses the printing system.

[0127] It should be recalled that various embodiments of the gas enclosure assembly utilized in embodiments of the gas enclosure system of the present teachings can be constructed in a contoured manner that minimizes the internal volume of the gas enclosure assembly while optimizing the working volume to accommodate various footprints of OLED printing system designs. For example, various embodiments of the contoured gas enclosure assembly of the present teachings can have a gas enclosure volume of about 6 m to about 95 m for various embodiments of the gas enclosure assembly of the present teachings, for example, covering Gen 3.5 to Gen 10 substrate sizes. Various embodiments of the contoured gas enclosure assembly of the present teachings can have a gas enclosure volume of, for example, but not limited to, about 15 m to about 30 m, which may be useful for OLED printing of Gen 5.5 to Gen 8.5 substrate sizes. Various embodiments of the auxiliary enclosure can be constructed as a section of a gas enclosure assembly and easily integrated with gas circulation and filtration, and purification components to form a gas enclosure system capable of sustaining an inert, substantially low-particle environment for processes requiring such an environment.

[0128] As shown in FIGS. 12 and 13, various embodiments of the gas enclosure system can include a pressurized inert gas recirculation system 3000. Various embodiments of the pressurized inert gas recirculation loop can utilize compressors, blowers, and combinations thereof.

[0129] For example, as shown in Figures 14 and 15, various embodiments of the gas enclosure system 503 and the gas enclosure system 504 can have an external gas loop 3200 for coordinating and controlling an inert gas source 3201 and a clean dry air (CDA) source 3203 for use in various aspects of the operation of the gas enclosure system 503 and the gas enclosure system 504. The gas enclosure system 503 and the gas enclosure system 504 can also include various embodiments of an internal particle filtration and gas circulation system, as well as various embodiments of an external gas purification system, as previously described. Such embodiments of the gas enclosure system can include a gas purification system for purifying various reactive species from the inert gas. Some commonly used, non-limiting examples of inert gases include nitrogen, any of the noble gases, and any combination thereof. Various embodiments of the gas purification system according to the present teachings can maintain various levels of various reactive species, including various reactive atmospheric gases such as water vapor and oxygen, and organic solvent vapors, at 100 ppm or less, e.g., 10 ppm or less, 1.0 ppm or less, or 0.1 ppm or less. In addition to the external loop 3200 for coordinating and controlling the inert gas source 3201 and the CDA source 3203, the gas enclosure assembly 503 and the gas enclosure system 504 can have a compressor loop 3250 that can supply inert gas for operating various devices and equipment that can be located inside the gas enclosure system 503 and the gas enclosure system 504.

[0130] 14 may include a compressor 3262, a first accumulator 3264, and a second accumulator 3268 configured to be in fluid communication. The compressor 3262 may be configured to compress inert gas drawn from the gas enclosure assembly 1101 to a desired pressure. An inlet side of the compressor loop 3250 may be in fluid communication with the gas enclosure assembly 1101 via a gas enclosure assembly outlet 3252 through a line 3254 having a valve 3256 and a check valve 3258. The compressor loop 3250 may be in fluid communication with the gas enclosure assembly 1101 on the outlet side of the compressor loop 3250 via the outer gas loop 3200. The accumulator 3264 may be disposed between the compressor 3262 and the junction of the compressor loop 3250 with the outer gas loop 3200 and may be configured to generate a pressure of 5 psig or higher. A second accumulator 3268 can be in the compressor loop 3250 to provide damping fluctuations due to compressor piston cycling at approximately 60 Hz. For various embodiments of the compressor loop 3250, the first accumulator 3264 can have a capacity between about 80 gallons and about 160 gallons, while the second accumulator can have a capacity between about 30 gallons and about 60 gallons. According to various embodiments of the gas enclosure system 503, the compressor 3262 can be a zero-admission compressor. Various types of zero-admission compressors can operate without leaking atmospheric gas into various embodiments of the gas enclosure system of the present teachings. Various embodiments of the zero-admission compressor can be implemented continuously during the OLED printing process, for example, utilizing the use of various devices and equipment requiring compressed inert gas.

[0131] The accumulator 3264 can be configured to receive and store compressed inert gas from the compressor 3262. The accumulator 3264 can supply compressed inert gas as needed within the gas enclosure assembly 1101. For example, the accumulator 3264 can provide gas to maintain pressure for various components of the gas enclosure assembly 1101, such as, but not limited to, one or more of a pneumatic robot, a substrate floating table, an air bearing, an air bushing, a compressed gas tool, a pneumatic actuator, and combinations thereof. As shown in FIG. 14 for the gas enclosure system 503, the gas enclosure assembly 1101 can have an OLED printing system 2000 enclosed therein. As schematically depicted in FIG. 14, the inkjet printing system 2000 can be supported by a printing system base 2100, which can be a granite stage. The printing system base 2100 can support a substrate support device such as a chuck, including, but not limited to, a vacuum chuck, a substrate floating chuck with pressure ports, and a substrate floating chuck with vacuum and pressure ports. In various embodiments of the present teachings, the substrate support device can be a substrate floating table, such as the substrate floating table 2200 depicted in FIG. 14 . The substrate floating table 2200 can be used for frictionless support of the substrate. In addition to the low-particle-generating floating table, the printing system 2000 can have a Y-axis motion system utilizing air bushings for frictionless Y-axis transport of the substrate. Additionally, the printing system 2000 can have at least one X- and Z-axis carriage assembly, with motion control provided by a low-particle-generating X-axis air bearing assembly. For example, various components of a low-particle-generating motion system, such as an X-axis air bearing assembly, can be used in place of various particle-generating linear mechanical bearing systems. For various embodiments of the gas enclosures and systems of the present teachings, the use of various air-operated devices and apparatus can provide low particle generation performance while being less maintenance intensive.The compressor loop 3250 can be configured to continuously supply pressurized inert gas to the various devices and apparatus of the gas enclosure system 503. In addition to supplying pressurized inert gas, the substrate floating table 2200 of the inkjet printing system 2000 utilizing air bearing technology also utilizes a vacuum system 3270, which is in fluid communication with the gas enclosure assembly 1101 through line 3272 when a valve 3274 is in the open position.

[0132] A pressurized inert gas recirculation system according to the present teachings can have a pressure-controlled bypass loop 3260, as shown in FIG. 14 for the compressor loop 3250, which acts to compensate for variable demand for pressurized gas during use, thereby providing a dynamic balance for various embodiments of a gas enclosure system according to the present teachings. For various embodiments of a gas enclosure system according to the present teachings, the bypass loop can maintain a constant pressure in the accumulator 3264 without disturbing or changing the pressure in the enclosure 1101. The bypass loop 3260 can have a first bypass inlet valve 3261 on the inlet side of the bypass loop that is closed unless the bypass loop 3260 is in use. The bypass loop 3260 can also have a backpressure regulator 3266 that can be used when the second valve 3263 is closed. The bypass loop 3260 can have a second accumulator 3268 located on the outlet side of the bypass loop 3260. For embodiments of compressor loop 3250 utilizing a zero-entry compressor, bypass loop 3260 can compensate for small deviations in pressure that may occur over time during use of the gas enclosure system. Bypass loop 3260 can be in fluid communication with compressor loop 3250 on its inlet side when bypass inlet valve 3261 is in an open position. When bypass inlet valve 3261 is open, inert gas from compressor loop 3250 can be recirculated through bypass loop 3260 to the compressor if it is not being demanded within the gas enclosure assembly 1101. Compressor loop 3250 is configured to divert inert gas through bypass loop 3260 when the pressure of the inert gas in accumulator 3264 exceeds a preset threshold pressure.The preset threshold pressure of the accumulator 3264 can be between about 25 psig and about 200 psig at a flow rate of at least about 1 cubic foot per minute (cfm), or between about 50 psig and about 150 psig at a flow rate of at least about 1 cubic foot per minute (cfm), or between about 75 psig and about 125 psig at a flow rate of at least about 1 cubic foot per minute (cfm), or between about 90 psig and about 95 psig at a flow rate of at least about 1 cubic foot per minute (cfm).

[0133] Various embodiments of the compressor loop 3250 can utilize various compressors other than zero-admission compressors, such as variable speed compressors or compressors that can be controlled to be either on or off. As previously discussed, a zero-admission compressor ensures that no atmospheric reactive species can be introduced into the gas enclosure system. Therefore, any compressor configuration that prevents atmospheric reactive species from being introduced into the gas enclosure system can be utilized in the compressor loop 3250. According to various embodiments, the compressor 3262 of the gas enclosure system 503 can be housed within, for example, but not limited to, a sealed enclosure. The interior of the enclosure can be configured in fluid communication with an inert gas source, for example, the same inert gas that forms the inert gas atmosphere for the gas enclosure assembly 1101. For various embodiments of the compressor loop 3250, the compressor 3262 can be controlled at a constant speed to maintain a constant pressure. In other embodiments of the compressor loop 3250 that do not utilize a zero entry compressor, the compressor 3262 may be turned off when a maximum threshold pressure is reached and turned on when a minimum threshold pressure is reached.

[0134] 15 of the gas enclosure system 504, a blower loop 3280 utilizing a vacuum blower 3290 is shown for operation of the substrate floating table 2200 of the inkjet printing system 2000 housed in the gas enclosure assembly 1101. As previously discussed for the compressor loop 3250, the blower loop 3280 can be configured to continuously supply pressurized inert gas to the substrate floating table 2200 of the printing system 2000.

[0135] Various embodiments of gas enclosure systems that can utilize a pressurized inert gas recirculation system can have various loops that utilize various pressurized gas sources, such as at least one of a compressor, a blower, and combinations thereof. In FIG. 15 for gas enclosure system 504, compressor loop 3250 can be in fluid communication with external gas loop 3200, which can be used to supply inert gas for high consumption manifold 3225 as well as low consumption manifold 3215. According to various embodiments of gas enclosure systems according to the present teachings as shown in FIG. 15 for gas enclosure system 504, high consumption manifold 3225 can be used to supply inert gas to various devices and apparatuses, such as, but not limited to, one or more of a substrate floating table, a pneumatic robot, an air bearing, an air bushing, and a compressed gas tool, and combinations thereof. For various embodiments of the gas enclosure system according to the present teachings, the low consumption 3215 can be used to supply inert gas to various apparatus and devices such as, but not limited to, one or more of isolators, and pneumatic actuators, and combinations thereof.

[0136] 15, a blower loop 3280 can be utilized to supply pressurized inert gas to various embodiments of the substrate floating table 2200, while a compressor loop 3250 in fluid communication with the external gas loop 3200 can be utilized to supply pressurized inert gas to, for example, but not limited to, one or more of a pneumatic robot, an air bearing, an air bushing, and a compressed gas tool, and combinations thereof. In addition to supplying pressurized inert gas, the substrate floating table 2200 of the OLED inkjet printing system 2000 utilizing air bearing technology can also supply pressurized inert gas to the line when the valve 3294 is in the open position. The gas enclosure assembly 1101 also utilizes a blower vacuum 3290 that is in communication with the gas enclosure assembly 1101 through a fan 3292. The housing 3282 of the blower loop 3280 can support a first blower 3284 to supply a pressurized source of inert gas to the substrate floating table 2200, and a second blower 3290 that acts as a vacuum source for the substrate floating table 2200, which is housed in an inert gas environment within the gas enclosure assembly 1101. Attributes that can make blowers suitable for use as either a pressurized inert gas or vacuum source for various embodiments of the substrate floating table include, but are not limited to, for example, that they are highly reliable, that they are low maintenance to maintain, that they have variable speed control, and that they have a wide range of flow rates, with various embodiments being capable of providing flow rates between about 100 m3 / hr and about 2,500 m3 / hr. Various embodiments of the blower loop 3280 may additionally have a first isolation valve 3283 at the inlet end of the compressor loop 3280, and a check valve 3285 and a second isolation valve 3287 at the outlet end of the blower loop 3280. Various embodiments of the blower loop 3280 may have an adjustable valve 3286, which may be, for example, but is not limited to, a gate, butterfly, needle, or ball valve, as well as a heat exchanger 3288 to maintain the inert gas from the blower loop 3280 to the substrate floating table 2200 at a specified temperature.

[0137] FIG. 15 depicts an external gas loop 3200, also shown in FIG. 14, for coordinating and controlling an inert gas source 3201 and a clean, dry air (CDA) source 3203 for use in various aspects of the operation of the gas enclosure system 503 of FIG. 14 and the gas enclosure system 504 of FIG. 15. The external gas loop 3200 of FIGS. 14 and 15 can include at least four mechanical valves. These valves include a first mechanical valve 3202, a second mechanical valve 3204, a third mechanical valve 3206, and a fourth mechanical valve 3208. These various valves are located in positions within the various flow lines that allow control of both the inert gas and an air source, such as the clean, dry air (CDA). According to the present teachings, an inert gas may be any gas that does not undergo a chemical reaction under a defined set of conditions. Some commonly used, non-limiting examples of inert gases include nitrogen, any of the noble gases, and any combination thereof. Extending from the internal inert gas source 3201 is an internal inert gas line 3210. The internal inert gas line 3210 continues linearly as a low consumption manifold line 3212, which is in fluid communication with a low consumption manifold 3215. A first segment of an intersection line 3214 extends from a first flow junction 3216 located at the intersection of the internal inert gas line 3210, the low consumption manifold line 3212, and the first segment of the intersection line 3214. The first segment of the intersection line 3214 extends to a second flow junction 3218. The compressor inert gas line 3220 extends from the accumulator 3264 of the compressor loop 3250 and terminates at the second flow junction 3218. CDA line 3222 extends from CDA source 3203 and continues as high consumption manifold line 3224 in fluid communication with high consumption manifold 3225. A third flow junction 3226 is located at the intersection of a second section 3228 of the intersection line, clean dry air line 3222, and high consumption manifold line 3224. The second section 3228 of the intersection line extends from second flow junction 3218 to third flow junction 3226. High consumption manifold 3225 can be used to supply various components that are high consumption to the CDA during maintenance.Valves 3204, 3208, and 3230 can be used to isolate the compressor to prevent reactive species such as oxygen and water vapor from contaminating the inert gas in the compressor and accumulator.

[0138] Various embodiments of the continuous circulation and filtration of inert gas in the gas enclosure assembly are part of a particle control system that can provide for maintaining a substantially low-particle environment within various embodiments of the gas enclosure system. Various embodiments of the gas circulation and filtration system can be designed to provide a low-particle environment for airborne particulate matter that meets the standards of International Standards Organization Standard (ISO) 14644-1:1999, “Cleanrooms and associated controlled environments—Part 1: Classification of air cleanliness,” as specified by Class 1 through Class 5. Additionally, various components of the particle control system can vent particulate matter into the gas circulation and filtration system to maintain a low-particle zone proximal to the substrate. A determination of airborne particulate matter can be performed on various embodiments of the gas enclosure system prior to the printing process for system validation, for example, using a portable particle counting device. In various embodiments of the gas enclosure system, a determination of airborne particulate matter can be performed in situ as an ongoing quality check while the substrate is being printed. For various embodiments of the gas enclosure system, determination of suspended particulate matter can be performed for system validation before a substrate is printed, as well as in situ while a substrate is being printed.

[0139] Various embodiments of gas circulation and filtration systems are depicted in FIGS. 16-18 . According to various embodiments of the gas circulation and filtration systems of the present teachings, piping can be installed within the interior formed by joining wall and ceiling frame members. For various embodiments of the gas enclosure assembly, piping may be installed during the construction process. According to various embodiments of the present teachings, piping may be installed within a gas enclosure frame assembly constructed from multiple frame members. In various embodiments, piping can be installed on the multiple frame members before they are joined to form the gas enclosure frame assembly. The piping for various embodiments of the gas enclosure system can be configured such that substantially all gas drawn into the piping from one or more piping inlets is transferred through various embodiments of a gas filtration loop for removing particulate matter within the gas enclosure assembly. Additionally, the piping of various embodiments of the gas enclosure system can be configured to separate the inlet and outlet of a gas purification loop external to the gas enclosure assembly from the gas filtration loop for removing particulate matter within the gas enclosure assembly. Various embodiments of piping according to the present teachings can be fabricated from metal sheet, for example, but not limited to, aluminum sheet having a thickness of about 80 mils.

[0140] 16 depicts a right front see-through perspective view of a circulation and filtration system 1500, which may include a piping assembly 1501 and a fan filter unit assembly 1502 of the gas enclosure assembly 100. The enclosure piping assembly 1501 may have a front wall panel piping assembly 1510. As shown, the front wall panel piping assembly 1510 may have a front wall panel inlet duct 1512 and a first front wall panel riser 1514 and a second front wall panel riser 1516, both in fluid communication with the front wall panel inlet duct 1512. The first front wall panel riser 1514 is shown with an outlet 1515 that is sealably engaged with the ceiling duct 1505 of the fan filter unit 103. Similarly, the second front wall panel riser 1516 is shown with an outlet 1517 that is sealably engaged with the ceiling duct 1507 of the fan filter unit 103. In that regard, the front wall panel piping assembly 1510 provides for circulating the inert gas within the gas enclosure system from the bottom, utilizing a front wall panel inlet duct 1512 through each front wall panel riser 1514 and 1516, and delivering the air through outlets 1505 and 1507, respectively, so that the air can be filtered, for example, by a fan filter unit 1552 of the fan filter unit assembly 1502. The proximal fan filter unit 1552 is a heat exchanger 1562 that, as part of a thermal conditioning system, can maintain the inert gas circulating through the gas enclosure assembly 100 at a desired temperature.

[0141] The right wall panel piping assembly 1530 is connected to the first riser 1534 of the right wall panel and the right wall 16 , the right wall panel piping assembly 1520 may have a right wall panel inlet duct 1532 in fluid communication with a right wall panel upper duct 1538 through a panel second riser 1536. The right wall panel upper duct 1538 may have a first duct inlet end 1535 and a second duct outlet end 1537 in fluid communication with a rear wall panel upper duct 1546 of the rear wall panel of the rear wall piping assembly 1540. The left wall panel piping assembly 1520 may have the same components as those described for the right wall panel assembly 1530, of which the left wall panel inlet duct 1522 is visible in FIG. 16 , in fluid communication with a left wall panel upper duct (not shown) through a first left wall panel riser 1524 and a first left wall panel riser 1524. The rear wall panel piping assembly 1540 can have a rear wall panel inlet duct 1542 in fluid communication with the left wall panel assembly 1520 and the right wall panel assembly 1530. Additionally, the rear wall panel piping assembly 1540 can have a rear wall panel bottom duct 1544, which can have a rear wall panel first inlet 1541 and a rear wall panel second inlet 1543. The rear wall panel bottom duct 1544 can be in fluid communication with a rear wall panel top duct 1546 via a first bulkhead 1547 and a second bulkhead 1549, which bulkhead structures can be used, for example, but not limited to, to route services from the exterior to the interior of the gas enclosure assembly 100. In accordance with the present teachings, the service bundle can include, for example, but not limited to, optical cables, electrical cables, wires and tubing, and the like. Recall that manufacturing facilities may require significant lengths of various service bundles that can be operatively connected from various systems and assemblies to provide the optical, electrical, mechanical, and fluid connections required to operate the printing system. Duct opening 1533 provides for movement of at least one service bundle out of upper duct 1546 of the rear wall panel that can pass through upper duct 1546 of the rear wall panel via bulkhead 1549.Bulkheads 1547 and 1549 can be sealed externally using removable inset panels, as previously described. The upper duct of the rear wall panel is in fluid communication with, for example, but not limited to, a fan filter unit 1554 through vent 545, the corner of which is shown in FIG. 16 . In that regard, left wall panel piping assembly 1520, right wall panel piping assembly 1530, and rear wall panel piping assembly 1540 provide for circulation of inert gas within the gas enclosure assembly from the bottom, utilizing wall panel inlet ducts 1522, 1532, and 1542, respectively, and rear panel lower duct 1544, which are in fluid communication with vent 1545 through various risers, ducts, bulkhead passages, and the like, as previously described. Thus, air can be filtered, for example, by fan filter unit 1554 of fan filter unit assembly 1502 of circulation and filtration system 1500. Proximal fan filter unit 1554 is a heat exchanger 1564 that, as part of a thermal conditioning system, can maintain the inert gas circulating through gas enclosure assembly 100 at a desired temperature. As discussed in further detail later herein, the number, size, and shape of fan filter units for a fan filter unit assembly, such as fan filter unit assembly 1502, including fan filter units 1552 and 1554 of circulation and filtration system 1500, can be selected according to the physical location of the substrate in the printing system during processing. The number, size, and shape of fan filter units for a fan filter unit assembly selected with respect to the physical movement of the substrate can be elements of a low-particle gas enclosure system that can provide a low-particle zone proximal to the substrate during the substrate manufacturing process.

[0142] FIG. 16 shows cable feed through opening 1533. As discussed in more detail later herein, various embodiments of the gas enclosure assembly of the present teachings provide for conveying service bundles through piping. To eliminate leak paths forming around such service bundles, various approaches can be used for sealing different sized cables, wires, and tubing within the service bundle using conforming materials. Also shown in FIG. 16 for the enclosure piping assembly 1501 are conduit I and conduit II, which are shown as part of the fan filter unit 103. Conduit I provides an outlet for inert gas to an external gas purification system, while conduit II provides return of purified inert gas to the internal circulation and filtration loop of the gas enclosure assembly 100.

[0143] 17, a top see-through perspective view of the enclosure piping assembly 1501 is shown. The symmetry of the left wall panel piping assembly 1520 and the right wall panel piping assembly 1530 can be seen. For the right wall panel piping assembly 1530, a right wall panel inlet duct 1532 is in fluid communication with an upper duct 1538 in the right wall panel through a first riser 1534 in the right wall panel and a second riser 1536 in the right wall panel. The upper duct 1538 in the right wall panel can have a first duct inlet end 1535 and a second duct outlet end 1537 that is in fluid communication with an upper duct 1546 in the rear wall panel of the rear wall piping assembly 1540. Similarly, the left wall panel piping assembly 1520 can have a left wall panel inlet duct 1522 in fluid communication with a left wall panel top duct 1528 through a left wall panel first riser 1524 and a left wall panel second riser 1526. The left wall panel top duct 1528 can have a first duct inlet end 1525 and a second duct outlet end 1527 in fluid communication with a rear wall panel top duct 1546 of the rear wall piping assembly 1540. In addition, the rear wall panel piping assembly can have a rear wall panel inlet duct 1542 in fluid communication with the left wall panel assembly 1520 and the right wall panel assembly 1530. In addition, the rear wall panel piping assembly 1540 can have a rear wall panel bottom duct 1544, which can have a rear wall panel first inlet 1541 and a rear wall panel second inlet 1543. A bottom duct 1544 of the rear wall panel can be in fluid communication with a top duct 1546 of the rear wall panel via a first bulkhead 1547 and a second bulkhead 1549 .16 and 17 can provide effective circulation of inert gas from a front wall panel piping assembly 1510, which circulates the inert gas from a front wall panel inlet duct 1512 to ceiling panel ducts 1505 and 1507 via front wall panel outlets 1515 and 1517, respectively, and from a left wall panel assembly 1520, a right wall panel assembly 1530, and a rear wall panel piping assembly 1540, which circulate the air from inlet ducts 1522, 1532, and 1542, respectively, to an air vent 1545. Once the inert gas is exhausted via the ceiling panel ducts 1505 and 1507 and the air vent 1545 into the enclosure region below the fan filter unit 103 of the enclosure 100, the so-exhausted inert gas can be filtered through fan filter units 1552 and 1554 of the fan filter unit assembly 1502. Additionally, the circulated inert gas can be maintained at a desired temperature by heat exchangers 1562 and 1564, which are part of a thermal regulation system.

[0144] 18 is a bottom perspective view of enclosure piping assembly 1501. Inlet piping assembly 1509 includes front wall panel inlet duct 1512, left wall panel inlet duct 1522, right wall panel inlet duct 1532, and rear wall panel inlet duct 1542, which are in fluid communication with each other. As previously discussed herein, conduit I provides an outlet for the inert gas to an external gas purification system, while conduit II provides a return of the purified inert gas to the internal circulation and filtration loop of gas enclosure assembly 100.

[0145] For each inlet duct included in the inlet piping assembly 1509, there are distinct openings evenly distributed across the bottom of each duct, a set of which are specifically highlighted for purposes of the present teachings as opening 1511 in front wall panel inlet duct 1512, opening 1521 in left wall panel inlet duct 1522, opening 1531 in right wall panel inlet duct 1532, and opening 1541 in right wall panel inlet duct 1542. Such openings, as visible across the bottom of each inlet duct, provide for effective intake of inert gas within enclosure 100 for continuous circulation and filtration. The continuous circulation and filtration of inert gas in various embodiments of the gas enclosure assembly is part of a particle control system, which can provide for maintaining a substantially low-particle environment within various embodiments of the gas enclosure system. Various embodiments of the gas circulation and filtration system can be designed to provide a low-particle environment for maintaining suspended particulate matter levels that meet the standards of International Standards Organization Standard (ISO) 14644-1:1999, as specified by Class 1 through Class 5. Additionally, service bundles, which can include cables, wires, and tubing bundled together, and the like, can act as particulate matter sources. Thus, by having the service bundles routed through piping, identified particulate sources can be contained within the piping and vented through the circulation and filtration system.

[0146] Various embodiments of the gas enclosure system can have a particle control system capable of maintaining a substantially low-particle environment, providing on-substrate particle specifications for particles from about 0.1 μm or larger to about 10 μm or larger. Various embodiments of the on-substrate particle specifications can be easily converted from an average on-substrate particle distribution per square meter of substrate per minute to an average on-substrate particle distribution per substrate per minute for each target particle size range. As previously discussed herein, such conversion can be easily performed, for example, through known relationships between substrates of a particular generation size and substrates of corresponding area for that substrate generation. Additionally, the average on-substrate particle distribution per square meter of substrate per minute can be easily converted to any of a variety of unit time representations. For example, in addition to converting between standard time units, e.g., seconds, minutes, and days, process-specific units of time can be used. For example, print cycles can be associated with units of time, as previously discussed herein.

[0147] Various embodiments of the low-particle gas enclosure system of the present teachings can maintain a low-particle environment that provides an average on-substrate particle distribution that meets an on-substrate deposition rate specification of less than or equal to about 100 particles per square meter of substrate per minute for particles greater than or equal to 10 μm in size. Various embodiments of the low-particle gas enclosure system of the present teachings can maintain a low-particle environment that provides an average on-substrate particle distribution that meets an on-substrate deposition rate specification of less than or equal to about 100 particles per square meter of substrate per minute for particles greater than or equal to 5 μm in size. Various embodiments of the gas enclosure system of the present teachings can maintain a low-particle environment that provides an average on-substrate particle distribution that meets an on-substrate deposition rate of less than or equal to about 100 particles per square meter of substrate per minute for particles greater than or equal to 2 μm in size. Various embodiments of the gas enclosure system of the present teachings can maintain a low-particle environment that provides an average particle distribution on the substrate that meets a deposition rate on the substrate of less than about 100 particles per square meter of substrate per minute for particles greater than or equal to 1 μm in size. Various embodiments of the low-particle gas enclosure system of the present teachings can maintain a low-particle environment that provides an average particle distribution on the substrate that meets a deposition rate on the substrate of less than about 1000 particles per square meter of substrate per minute for particles greater than or equal to 0.5 μm in size. Various embodiments of the gas enclosure system of the present teachings can maintain a low-particle environment that provides an average particle distribution on the substrate that meets a deposition rate on the substrate of less than about 1000 particles per square meter of substrate per minute for particles greater than or equal to 0.3 μm in size. Various embodiments of the low-particle gas enclosure system of the present teachings can maintain a low-particle environment that provides an average on-substrate particle distribution that meets an on-substrate deposition rate of less than or equal to about 1000 particles per square meter of substrate per minute for particles greater than or equal to 0.1 μm in size.

[0148] Manufacturing facilities may require significant lengths of various service bundles that can be operably connected from various devices and systems to provide the optical, electrical, mechanical, and fluid connections required to operate, for example, a printing system. According to the present teachings, service bundles can include, for example, but are not limited to, optical cables, electrical cables, wires and tubing, and the like. Various embodiments of service bundles according to the present teachings may have significant overall dead volumes as a result of the significant number of gaps created by bundling the various cables, wires and tubing, and the like, together in the service bundle. The overall dead volume due to the significant number of gaps in the service bundle can result in the retention of significant amounts of reactive gas species trapped therein. Such a significant source of reactive atmospheric gas can significantly increase the recovery time of a gas enclosure assembly, for example, after maintenance.

[0149] Thus, in addition to providing components of a particle control system, delivering a service bundle through piping can reduce the recovery time of the gas enclosure assembly with respect to reactive species, thereby more quickly returning the gas enclosure assembly within specifications for performing air-sensitive processes. For various embodiments of the gas enclosure system of the present teachings useful for printing OLED devices, various levels of various reactive species, including various reactive atmospheric gases such as water vapor and oxygen, and organic solvent vapors, can be maintained at 100 ppm or less, e.g., 10 ppm or less, 1.0 ppm or less, or 0.1 ppm or less.

[0150] To understand how cabling routed through piping can result in a reduction in the time required to purge occluded reactive atmospheric gases from gaps in the service bundle created as a result of bundling various optical cables, electrical cables, wires, and fluid tubing, and the like, refer to FIGS. 19A, 19B, and 20. FIG. 19A depicts an expanded view of service bundle I, which may be a bundle that can include tubing, such as tubing A, which may be for delivering various inks, solvents, and the like to a printing system, such as printing system 1050 of FIG. 13A. Service bundle I of FIG. 19A may additionally include electrical wiring, such as conductor B, or cabling, such as cable C, which may be coaxial or optical cable. Such tubing, wires, and cables included in the service bundle can be routed from the exterior to the interior to connect to various devices and apparatuses that comprise the OLED printing system. As seen in the shaded area of ​​FIG. 19A, gaps in the service bundle can create a sensible dead volume D. In the schematic perspective view of FIG. 19B, when service bundle I is fed through duct II, inert gas III can continuously pass through the tube. The enlarged cross-sectional view of FIG. 20 illustrates how continuously passing inert gas through bundled tubing, wires, and cables can effectively increase the removal rate of occluding reactive species from the dead volume formed in the service bundle. The diffusion rate of reactive species A out of the dead volume, indicated in FIG. 20 by the collection area occupied by species A, is inversely proportional to the concentration of the reactive species outside the dead volume, indicated in FIG. 20 by the collection area occupied by inert gas species B. That is, if the concentration of the reactive species is high in the volume just outside the dead volume, the diffusion rate is reduced. If the concentration of the reactive species in such an area is continuously reduced from the volume just outside the dead volume by the inert gas flow rate and then by mass action, the rate at which the reactive species diffuses out of the dead volume is increased. Additionally, by the same principle, inert gas can diffuse into the dead volume once occluding reactive species are effectively removed from these spaces.

[0151] 21A is a perspective view of the rear corner of various embodiments of the gas enclosure assembly 101, with a see-through view into the gas enclosure assembly 101 through the return duct 1605. For various embodiments of the gas enclosure assembly 101, the rear wall panel 1640 can have an inset panel 1610 configured to provide access to, for example, an electrical bulkhead. The service bundle can be routed through the bulkhead into a cable routing duct, such as duct 1632 shown in the right wall panel 1630, with the removable inset panel removed to reveal the service bundle routed into the first service bundle duct inlet 636. From there, the service bundle can be routed into the interior of the gas enclosure assembly 101, shown in a see-through view through the return duct 1605 within the interior of the gas enclosure assembly 101. Various embodiments of the gas enclosure assembly for service bundle routing can have more than one service bundle inlet, as shown in FIG. 21A , which depicts a first service bundle duct inlet 1634 and a second service bundle duct inlet 1636 for yet another service bundle. FIG. 21B depicts a close-up view of the first service bundle duct inlet 1634 for a cable, wire, and tubing bundle. The first service bundle duct inlet 1634 can have an opening 1631 designed to form a seal with a sliding cover 1633. In various embodiments, the opening 1631 can accommodate a flexible sealing module, such as those offered by Roxtec Company for cable inlet seals, which can accommodate various diameters of cables, wires, tubing, and the like, in the service bundle. Alternatively, the top 1635 of the sliding cover 1633 and the upper portion 1637 of the opening 1631 may have a conforming material disposed on each surface such that the conforming material can form a seal around various sized diameters of cables, wires, tubing, and the like in the service bundle fed through an inlet such as the first service bundle duct inlet 1634.

[0152] As depicted in Figures 22 and 23, one or more fan filter units can be configured to provide a substantially laminar gas flow through the interior of the gas enclosure assembly. According to various embodiments of the circulation and filtration system for a gas enclosure assembly of the present teachings, the one or more fan units are disposed adjacent a first interior surface of the gas enclosure assembly, and one or more piping inlets are disposed adjacent a second, opposite interior surface of the gas enclosure assembly. For example, as shown in Figures 16-18, the gas enclosure assembly can include an interior ceiling and a bottom interior perimeter, and the one or more fan units can be disposed adjacent the interior ceiling, and the one or more piping inlets can include a plurality of inlet openings disposed adjacent the bottom interior perimeter that are part of the piping system.

[0153] FIG. 22 is a cross-sectional view taken along the length of a gas enclosure system 505 according to various embodiments of the present teachings. The gas enclosure system 505 of FIG. 22 can include a gas enclosure assembly 1100 that can house the OLED inkjet printing system 2001, as well as a circulation and filtration system 1500, a gas purification system 3130 ( FIGS. 12 and 13 ), and a thermal conditioning system 3140. The circulation and filtration system 1500 can include a piping assembly 1501 and a fan filter unit assembly 1502. The thermal conditioning system 3140 can include a fluid cooling device 3142 that is in fluid communication with a cooling device outlet line 3141 and a cooling device inlet line 3143. The cooled fluid can exit the fluid cooling device 3142 and flow through the cooling device outlet line 3141 and be delivered to a heat exchanger that can be located proximate each of the multiple fan filter units for various embodiments of the gas enclosure system, as shown in FIG. 22 . From the heat exchanger proximal to the fan filter unit, fluid can be returned to the chiller 3142 through the chiller inlet line 3143 to be maintained at a constant desired temperature. As previously discussed herein, the chiller outlet line 3141 and the chiller inlet line 3143 are in fluid communication with multiple heat exchangers, including a first heat exchanger 1562, a second heat exchanger 1564, and a third heat exchanger 1566. According to various embodiments of the gas enclosure system 505 as shown in FIG. 22 , the first heat exchanger 1562, the second heat exchanger 1564, and the third heat exchanger 1566 are in thermal communication with the first fan filter unit 1552, the second fan filter unit 1554, and the third fan filter unit 1556, respectively, of the fan filter unit assembly 1502 of the circulation and filtration system 1500.

[0154] In Figure 22, multiple arrows depict airflow within circulation and filtration system 1500 to provide low-particle filtered air within gas enclosure assembly 1100. In Figure 22, piping assembly 1501 can include a first piping conduit 1573 and a second piping conduit 1574, as depicted in the simplified schematic diagram of Figure 22. First piping conduit 1573 can receive gas through first piping inlet 1571 and can exit through first piping outlet 1575. Similarly, second piping conduit 1574 can receive gas through second piping inlet 1572, which exits through second piping outlet 1576. 22, the piping assembly 1501 separates the inert gas recirculated internally through the fan filter unit assembly 1502 by effectively defining a space 1580 that can be in fluid communication with the gas purification system 3130 via the gas purification outlet line 3131 and the gas purification inlet line 3133. Such circulation systems, including various embodiments of piping systems such as those described with respect to FIGS. 16-18, provide substantially laminar flow, minimize turbulence, and facilitate the circulation, conversion, and filtration of particulate matter in the gas atmosphere within the interior of the enclosure and through the gas purification system external to the gas enclosure assembly.

[0155] FIG. 23 is a cross-sectional view taken along the length of a gas enclosure system 506 according to various embodiments of a gas enclosure system according to the present teachings. Like gas enclosure system 505 of FIG. 22, gas enclosure system 506 of FIG. 23 can include gas enclosure assembly 1100 that can house OLED inkjet printing system 2001, as well as circulation and filtration system 1500, gas purification system 3130 ( FIG. 15 ), and thermal conditioning system 3140. Circulation and filtration system 1500 can include piping assembly 1501 and fan-filter unit assembly 1502. For various embodiments of gas enclosure system 506, thermal conditioning system 3140, including fluid cooling device 3142 in fluid communication with cooling device outlet line 3141 and cooling device inlet line 3143, can be in fluid communication with multiple heat exchangers, e.g., first heat exchanger 1562 and second heat exchanger 1564, as depicted in FIG. 23 . 22, various heat exchangers, such as first heat exchanger 1562 and second heat exchanger 1564, can be positioned proximate duct outlets, such as first piping outlet 1575 and second piping outlet 1576, of piping assembly 1501, thereby being in thermal communication with the circulating inert gas. In that regard, the inert gas being returned for filtration from duct inlets, such as duct inlets, such as first piping inlet 1571 and second piping inlet 1572, of piping assembly 1501, can be thermally conditioned prior to being circulated through, for example, first fan filter unit 1552, second fan filter unit 1554, and third fan filter unit 1556, respectively, of fan filter unit assembly 1502 of FIG.

[0156] As can be seen from the arrows indicating the direction of inert gas circulation through the enclosure in Figures 22 and 23, the fan filter unit can be configured to provide a substantially laminar flow downward from the top to the bottom of the enclosure. For example, a fan filter unit manufactured by Flanders Corporation (Washington, North Carolina) can be used. Fan filter units available from Envirco Corporation (Sanford, North Carolina) may be useful for incorporation into various embodiments of a gas enclosure assembly according to the present teachings. Various embodiments of the fan filter units are capable of exchanging between about 350 cubic feet per minute (CFM) and about 700 CFM of inert gas through each unit. As shown in FIGS. 22 and 23, because the fan filter units are in a parallel rather than serial arrangement, the amount of inert gas that can be exchanged in a system with multiple fan filter units is proportional to the number of units used.

[0157] Near the bottom of the enclosure, gas flow is directed towards a plurality of duct inlets, shown schematically in Figures 22 and 23 as first duct inlet 1571 and second duct inlet 1572 of duct assembly 1501. As previously discussed herein with respect to Figures 16-18, locating the duct inlets substantially at the bottom of the enclosure and causing downward gas flow from the upper fan filter unit promotes good conversion of the gas atmosphere within the enclosure and encourages thorough conversion and movement of the entire gas atmosphere through the gas purification system used in conjunction with the enclosure. By circulating the gas atmosphere through piping using a circulation and filtration system 1500 in which a piping assembly 1501 separates the inert gas stream for circulation through a gas purification loop 3130, and promoting laminar flow and thorough conversion of the gas atmosphere within the enclosure, levels of each of the reactive species, such as water and oxygen, and each of the solvents, can be maintained at 100 ppm or less, for example, 1 ppm or less, for example, 0.1 ppm or less, in various embodiments of the gas enclosure assembly.

[0158] FIG. 24 is a schematic front view of gas enclosure system 507, which may be a schematic front view of gas enclosure system 505 of FIG. 22. Further details of printing system 2001, depicted enclosed within gas enclosure system 507, can be seen in FIG. 24. Various embodiments of the gas enclosure system of the present teachings having a particle control system can provide a low-particle zone proximate a substrate, such as substrate 2050 of FIG. 24, which may be supported by substrate support apparatus 2200. Substrate support apparatus 2200 of printing system 2001 for various embodiments of the printing system can be a chuck or a floating table. As previously discussed herein, various embodiments of the gas circulation and filtration system according to the present teachings can include a piping assembly, such as piping assembly 1501 of FIG. 24, and a fan filter unit assembly, which can have multiple fan filter units, such as fan filter unit assembly 1502, where fan filter unit 1552 is shown in the schematic front view of FIG. 24. The gas flow indicated by the arrows depicts laminar flow of filtered gas proximate the substrate 2050. Recall that a laminar flow environment can minimize turbulence and create a substantially low-particle environment capable of maintaining suspended particulate matter levels that meet International Standards Organization Standard (ISO) 14644-1:1999 standards as specified by Class 1 through Class 5.

[0159] As discussed in more detail later herein, for various embodiments of the gas enclosure system of the present teachings, an effective gas circulation and filtration system can be part of the particle control system. However, various particle control systems of the present teachings can also prevent particle generation proximate to the substrate during the printing process. As depicted in FIG. 24 for the gas enclosure assembly 1100 of the gas enclosure system 507, the substrate 2050 can be proximate to various components of the printing system 2001 that can generate particles. For example, the X, Z carriage assembly 2300 can include components such as a linear bearing system that can generate particles. The service bundle housing 2410 can contain a particle generation service bundle that operably connects various devices and systems to the gas enclosure system, including the printing system. Various embodiments of the service bundle can include bundled optical cables, electrical cables, wires and tubing, and the like, to provide optical, electrical, mechanical, and fluid functions for the various assemblies and systems disposed within the gas enclosure system.

[0160] Gas enclosure systems of the present teachings can have various components that provide a particle control system. Various embodiments of particle control systems can include a gas circulation and filtration system in fluid communication with contained particle-generating components so that such particle-containing components can be vented into the gas circulation and filtration system. For various embodiments of particle control systems, contained particle-generating components can be vented into a dead space, making such particulate matter inaccessible for recirculation within the gas enclosure system. Various embodiments of gas enclosure systems of the present teachings can have particle control systems in which various components can be inherently low particle-generating, thereby preventing particles from accumulating on a substrate during the printing process. Various components of particle control systems of the present teachings can utilize the containment and venting of particle-generating components and the selection of inherently low particle-generating components to provide a low-particle zone proximal to the substrate.

[0161] According to various embodiments of a gas enclosure system used in an OLED printing system, the number of fan filter units can be selected according to the physical position of the substrate within the printing system during processing. Accordingly, the number of fan filter units can vary according to the movement of the substrate through the gas enclosure system. For example, FIG. 25 is a cross-sectional view taken along the length of a gas enclosure system 508, a gas enclosure system similar to that depicted in FIG. 9 . The gas enclosure system 508 can include a gas enclosure assembly 1100 that houses an OLED inkjet printing system 2001 supported on a gas enclosure assembly base 1320. The substrate floating table 2200 of the OLED printing system defines a movement that can move the substrate through the gas enclosure system 508 during processing of the substrate. Accordingly, the fan filter unit assembly 1502 of the gas enclosure system 508 has an appropriate number of fan filter units, designated 1551-1555, corresponding to the physical movement of the substrate through the inkjet printing system 2001 during processing. Additionally, the schematic cross-sectional view of FIG. 25 depicts the contouring of various embodiments of the gas enclosure that can effectively reduce the volume of inert gas required during the OLED printing process while at the same time providing immediate access to the interior of the gas enclosure assembly 1100, either remotely during processing, for example, using gloves installed in various glove ports, or directly through various removable panels in the event of maintenance operations.

[0162] FIG. 26 depicts a printing system 2002 according to various embodiments of the printing system of the present teachings. The printing system 2002 can have many of the features previously described for the printing system 2000 of FIG. 10B . The printing system 2002 can be supported by a printing system base 2101. A first riser 2120 and a second riser 2122, on which a bridge 2130 can be mounted, can be perpendicular to the printing system base 2101 and can be mounted thereon. For various embodiments of the inkjet printing system 2002, the bridge 2130 can support at least one X-axis carriage assembly 2300 that can move in the X-axis direction relative to the substrate support apparatus 2250 through a service bundle carrier run 2401. As discussed in more detail later herein, for various embodiments of the printing system 2002, the X-axis carriage assembly 2300 can utilize a linear air bearing motion system that is inherently low particle generating. According to various embodiments of the printing system of the present teachings, the X-axis carriage can have a Z-axis translation plate mounted thereon. In FIG. 26, X-axis carriage assembly 2300 is depicted with a first Z-axis translation plate 2315. In various embodiments of printing system 2002, a second X-axis carriage assembly can be mounted on bridge 2130, which can also have a Z-axis translation plate mounted thereon. In that regard, similar to printing system 2000 of FIG. 10B, for various embodiments of OLED inkjet printing system 2002, there can be two carriage assemblies, each with a printhead assembly, e.g., printhead assembly 2500 of FIG. 26, and a second printhead assembly mounted on a second X, Z-axis carriage assembly (not shown). In various embodiments of the printing system 2002, a first printhead assembly, such as printhead assembly 2500 of FIG. 26, can be mounted on a first X, Z-axis carriage assembly, while a camera system for inspecting features of the substrate 2050 can be mounted on a second X, Z-axis carriage assembly (not shown).In various embodiments of printing system 2002 of FIG. 26, a printhead assembly such as printhead assembly 2500 of FIG. 26 may be mounted on an X, Z-axis carriage assembly, while either an ultraviolet lamp or a heat source for curing the encapsulation layer printed on substrate 2050 may be mounted on a second X, Z-axis carriage assembly (not shown).

[0163] According to various embodiments of the printing system 2002, the substrate support device 2250 may be a floating table similar to the floating table 2200 of the printing system 2000 of FIG. 10B, which can contain the substrate in the X and Y planes and can use a floating table to secure a stable Z-axis flying height. In various embodiments of the printing system 2002, the substrate support device 2250 may be a chuck. In various embodiments of the printing system 2002, the chuck may have a top surface 2252 for mounting the substrate. In various embodiments of the printing system 2002, the top surface 2252 may support a top plate, which may be interchangeable, allowing for easy interchangeability between different substrate sizes and types. In various embodiments of the printing system 2002, the top plate may accommodate multiple substrates of different sizes and types. In various embodiments of the printing system 2002 that can utilize a chuck as the substrate support device, the substrate may be held firmly on the chuck during the printing process using vacuum, magnetic, or mechanical means known in the art. The precision XYZ motion system can have various components for positioning a substrate mounted on the substrate support apparatus 2250 relative to the print head assembly 2500, which can include a Y-axis motion assembly 2355 as well as an X, Z carriage assembly 2300. The substrate support apparatus 2250 can be mounted on the Y-axis motion assembly 2355 and can move on a rail system 2360 using, for example, but not limited to, a linear bearing system utilizing either mechanical or air bearings. For various embodiments of a gas enclosure system, the air bearing motion system helps facilitate frictionless transport of a substrate disposed on the substrate support apparatus 2250 in the Y-axis direction. The Y-axis motion system 2355 can also optionally use dual rail motion, again provided by a linear air bearing motion system or a linear mechanical bearing motion system. Other precision XYZ motion systems can be used in accordance with the present teachings, such as, for example, but not limited to, various embodiments of a three-axis gantry system.For example, various embodiments of a three-axis gantry system can have an X, Z carriage assembly mounted on a gantry bridge for precision X, Z axis movement, which allows the gantry to be precisely moved in the Y axis.

[0164] In addition to a gas circulation and filtration system for maintaining a low particle environment within the gas enclosure system, various embodiments of printing systems, such as printing system 2000 of FIG. 10B and printing system 2002 of FIG. 26, can have additional components incorporated into the gas enclosure system that prevent particle generation proximate to the substrate during the printing process. For example, printing system 2000 of FIG. 10B and printing system 2002 of FIG. 26 may include a linear air A bearing system 2320 can be used to have an inherently low particle generating X-axis motion system that can mount and position the X,Z carriage assembly 2300 on the bridge 2130. Additionally, the printing system 2000 of FIG. 10B and the printing system 2002 of FIG. 26 can have a service stack housing exhaust system 2400 for containing and exhausting particles generated from the service stack.

[0165] According to the present teachings, service bundles can include, by way of non-limiting example, optical cables, electrical cables, wires and tubing, and the like. Various embodiments of service bundles of the present teachings can be operably connected to various systems and apparatus within a gas enclosure system to provide, for example, but not limited to, optical, electrical, mechanical, and fluid connections required for the operation of various devices and apparatus associated with a printing system. Given the size and complexity of the various service bundles, the various motion systems often require a service bundle carrier to manage the service bundles as they are moved with the motion systems. For various embodiments of the gas enclosure system of the present teachings, the service bundle can be a flexible string for tying together a bundle of cabling, wires and tubing, and the like at regular intervals. For various embodiments of the gas enclosure system of the present teachings, the service bundle carrier can be a sheath or jacket that can cover the bundle of cabling, wires and tubing, and the like of the service bundle. In various embodiments of the gas enclosure system of the present teachings, the service bundle carrier can form together a bundle of cabling, wires and tubing, and the like, of the service bundle. In various embodiments, the service bundle carrier can be a segmented or flexible chain that can support and carry a bundle of cabling, wires and tubing, and the like.

[0166] According to various embodiments of the gas enclosure system of the present teachings, a service bundle enclosure, which can include a service bundle managed using a service bundle carrier, can contain particulate matter generated from the service bundle and the service bundle carrier within the service bundle enclosure. Additionally, as discussed in more detail later herein, movement of the service bundle carrier can compress an air volume in a piston-like manner as it moves within the service bundle enclosure, creating a positive pressure differential between the interior service bundle enclosure and the ambient environment outside the service bundle enclosure, which can allow particulate matter formed from particle-generating components associated with the service bundle carrier to escape, for example, through openings formed by the carrier run. Such particulate matter just proximate to the substrate has a significant potential to contaminate the substrate surface before being passed into the circulation and filtration system. Thus, a service bundle enclosure exhaust system can be a component of various embodiments of a particle control system of a gas enclosure system that can contain and exhaust the service bundle enclosure to ensure a substantially low-particle printing environment.

[0167] 26 and indicated by the dashed lines, for various embodiments of the service bundle housing exhaust system 2400, the service bundle housing 2410 and the service bundle housing exhaust plenum 2420 can be an integral assembly. For such embodiments, the service bundle housing exhaust system 2400 can ensure that a positive pressure differential can be maintained between the inlet and outlet portions of the service bundle housing to exhaust particles generated within the service bundle housing 2410 into the gas circulation and filtration system through a first duct 2422 of the service bundle housing exhaust plenum and a second duct 2424 of the service bundle housing exhaust plenum. Alternatively, for various embodiments, the service bundle housing exhaust system 2400 can include a service bundle housing exhaust plenum 2420 that can be mounted on and in fluid communication with the service bundle housing 2410. The service bundle housing 2410 can contain particles generated by the service bundle, which can include bundled optical cables, electrical cables, wires and tubing, and the like. Various embodiments of the service bundle of the present teachings can provide at least one of optical, electrical, mechanical, and fluidic functionality for various assemblies and systems disposed inside the gas enclosure to a gas enclosure system, which can include a printing system. For various embodiments of the printing system 2002, the service bundle housing exhaust system 2400 can ensure that a positive pressure differential can be maintained between the inlet and outlet portions of the service bundle housing to exhaust particles contained in the service bundle housing 2410 into the service bundle housing exhaust plenum 2420. The service bundle housing exhaust plenum 2420 can be in fluid communication with a gas circulation and filtration system through a service bundle housing exhaust plenum first duct 2422 and a service bundle housing exhaust plenum second duct 2424. Alternatively, the first duct 2422 of the service bundle housing discharge plenum and the second duct 2424 of the service bundle housing discharge plenum can be fitted with flexible exhaust hoses so that particles contained by the service bundle housing can be exhausted through the service bundle housing discharge plenum and directed via a flexible exhaust pipe leading into the target dead space.

[0168] Furthermore, in addition to maintaining a positive pressure differential between the inlet and outlet portions of the service bundle housing exhaust system, various embodiments of the service bundle housing exhaust system may further maintain a relatively neutral or negative pressure differential between the interior of the service bundle housing exhaust system and the surrounding environment. Such a relatively neutral or negative pressure differential that may be maintained between the interior of the service bundle housing exhaust system and the surrounding environment may prevent particles from leaking out of the service bundle housing exhaust system through cracks, seams, and the like. Particle leakage through cracks, seams, and the like that are just proximate to the substrate has a significant potential to contaminate the substrate surface before being passed into the circulation and filtration system.

[0169] FIG. 27A depicts a side cross-sectional view of a low particle generating X-axis motion system 2320 in accordance with various embodiments of the present teachings. In FIG. 27A, the low particle generating X-axis motion system 2320 is depicted in relation to a service bundle housing exhaust system 2400, which may have a service bundle housing 2410 as shown in FIG. 27A, and a service bundle housing exhaust plenum 2420 in fluid communication with a first duct 2422 of the service bundle housing exhaust plenum. The printing system 2002 may include a base 2101 on which a substrate support 2250 may be mounted. The X, Z carriage assembly 2300 may be mounted on a bridge 2130. As can be seen in the cross-sectional view presented in FIG. 27A, the X-axis motion system 2320 may be a linear air bearing motion system that is inherently low particle generating. The X-axis motion system 2320 may include a plurality of air bearing packs 2330 and a brushless linear motor 2340. The service bundle carrier 2430 can be mounted on the X, Z carriage assembly 2300 and housed in the service bundle housing 2410. As depicted in FIG. 27A , the service bundle housing exhaust plenum 2420 can be in fluid communication with the service bundle housing 2410 and with a gas circulation and filtration system through piping, such as the first duct 2422 of the service bundle housing exhaust plenum. In that regard, the service bundle housing 2410 can exhaust particles generated from various embodiments of the service bundle. A service bundle according to the present teachings can be a bundle that can include, for example, but is not limited to, optical cables, electrical cables, wires and tubing, and the like, which can be managed using various embodiments of the service bundle carrier 2430. Various embodiments of the service bundle of the present teachings can be operably connected to a printing system to provide, for example, but not limited to, the various optical, electrical, mechanical, and fluid connections required to operate the printing system. For various embodiments of the gas enclosure of the present teachings, a service bundle carrier, such as service bundle carrier 2430, can be supported by the bottom side 2404 of the service bundle housing.For various embodiments of the gas enclosure of the present teachings, the service bundle carriers, such as service bundle carrier 2430, can be supported by a tray or shelf.

[0170] FIG. 27B is an enlarged view of FIG. 27A depicting the low particle generating X-axis motion system 2320 of the printing system 2002 in further detail. Multiple air bearing pucks 2330 can be mounted on an inner surface of the X, Z axis carriage assembly 2300. In that regard, various embodiments of the low particle generating X-axis motion system 2320 can provide frictionless movement of the X, Z axis carriage assembly 2300 across the bridge 2130. In FIG. 27A, a first puck 2332 and a second puck 2334 are shown proximate the first side 2132 of the bridge 2130. A third puck 2336 in FIG. 27B can be proximate the top surface 2133 of the bridge 2130, while a fourth puck 2338 can be proximate the second side 2134 of the bridge 2130. The brushless linear motor can include an X-, Z-axis carriage assembly magnet track 2342, which can be mounted on the bridge 2130, and linear motor windings 2344, which can be mounted on the X-, Z-axis carriage assembly 2300. An encoder read head 2346 can be associated with the linear motor windings 2344 to position the linear motor 2340. In various embodiments of the brushless linear motor 2340, the encoder read head 2346 can be an optical encoder. As discussed in further detail later herein, various embodiments of the low particle X-axis motion system 2320 utilizing on a frictionless air bearing pack can be integrated with various embodiments of a compressor loop, as shown and described with respect to FIGS. 33 and 34 . Finally, as shown in FIG. 27B , the service bundle housing discharge system 2400 can include a service bundle housing 2410, which can house a service bundle carrier 2430. The service bundle housing exhaust system 2400 can contain and exhaust exhaust particles from the service bundle housing 2410, which can be generated from the service bundle, which can be managed using a service bundle carrier, such as the service bundle carrier 2430.

[0171] FIG. 28A is a front perspective view of printing system 2003 shown with service stack housing ejection system 2400 mounted on bridge 2130. Various embodiments of printing system 2003 can have many of the features previously described for printing system 2000 of FIG. 10B and printing system 2002 of FIG. 26. For example, printing system 2003 can be supported by printing system base 2101. First riser 2120 and second riser 2122, on which bridge 2130 can be mounted, can be perpendicular to and mounted on printing system base 2101. For various embodiments of inkjet printing system 2003, bridge 2130 can support at least one X-axis carriage assembly 2300 that can move in the X-axis direction relative to substrate support apparatus 2250 through service stack carrier run 2401. According to various embodiments of the printing system of the present teachings, the X-axis carriage 2300 can have a Z-axis moving plate 2310 mounted thereon. In that regard, various embodiments of the carriage assembly 2300 can provide precise X, Z positioning of the print head assembly 2500 relative to the substrate support apparatus 2250. In various embodiments of the printing system 2003, the second X-axis carriage assembly can be mounted on a bridge 2130, on which the second X-axis carriage can have a Z-axis moving plate mounted thereon. For embodiments of the printing system 2003 having two X-axis carriage assemblies, either a print head assembly can be mounted on each X, Z-axis carriage, or various other devices can be mounted on the two X, Z-axis carriage assemblies, such as, for example, a camera, ultraviolet lamps, and heat sources, as described for printing systems 2000 of FIG. 10B and 2002 of FIG. 26 . According to various embodiments of the printing system 2003, the substrate support device 2250 for supporting the substrate may be a floating table similar to the floating table 2200 of the printing system 2000 of FIG. 10B, or may be a chuck as previously described for the printing system 2002 of FIG. 26.The printing system 2003 of FIG. 28A is an inherently low particle generating X axis motion system that can mount and position an X,Z carriage assembly 2300 on a bridge 2130 using an air bearing linear slider assembly. For various printing systems of the present teachings, the air bearing linear slider assembly can fully encase the bridge 2130, allowing frictionless movement of the X, Z carriage assembly 2300 on the bridge 2130, and also provides a three-point mount that can preserve precision in the movement of the X, Z carriage assembly 2300, while resisting skew.

[0172] For precise movement of the substrate relative to the print head assembly, various embodiments of the printing system 2003 of FIG. 28A can have a precision XYZ motion system that can include a Y-axis motion assembly 2355 in addition to the X, Z carriage assembly 2300. The substrate support 2250 can be mounted on the Y-axis motion assembly 2355 and can move on a rail system 2360 using, for example, but not limited to, a linear bearing system utilizing either mechanical or air bearings. For various embodiments of a gas enclosure system, the air bearing motion system helps facilitate frictionless transport of the substrate disposed on the substrate support 2250 in the Y-axis direction. The Y-axis motion system 2355 can also optionally use dual rail motion, again provided by a linear air bearing motion system or a linear mechanical bearing motion system. Other precision XYZ motion systems can be used in accordance with the present teachings, such as, for example, but not limited to, various embodiments of a three-axis gantry system. For example, various embodiments of a three-axis gantry system can have an X, Z carriage assembly mounted on a gantry bridge for precision X, Z axis movement, which allows the gantry to be precisely moved in the Y axis.

[0173] As depicted in FIG. 28A , for various embodiments of the printing system 2003, the service bundle housing exhaust system 2400 can be mounted over the bridge 2130. The service bundle housing exhaust system 2400 can include a service bundle housing exhaust plenum 2420 that can be mounted to and in fluid communication with the service bundle housing 2410. The service bundle housing 2410 can contain particles generated by the service bundle, which can include bundled optical cables, electrical cables, wires, and tubing. Various embodiments of the service bundle of the present teachings can provide at least one of optical, electrical, mechanical, and fluidic functionality for various assemblies and systems disposed therein to a gas enclosure system, which can include a printing system. For various embodiments of the printing system 2003, the service bundle housing exhaust system 2400 can ensure that a positive pressure differential can be maintained between an inlet portion and an outlet portion of the service bundle housing exhaust system to exhaust particles contained within the service bundle housing 2410 into the service bundle housing exhaust plenum 2420. The service bundle housing discharge plenum 2420 can be in fluid communication with the gas circulation and filtration system through a service bundle housing discharge plenum first duct 2422 and a service bundle housing discharge plenum second duct 2424. Alternatively, the service bundle housing discharge plenum first duct 2422 and the service bundle housing discharge plenum second duct 2424 can be fitted with flexible exhaust hoses such that particles contained by the service bundle housing can be exhausted through the service bundle housing discharge plenum and directed via a flexible exhaust pipe leading into the targeted dead space.

[0174] Furthermore, for various embodiments of the service bundle housing exhaust system, in addition to maintaining a positive pressure differential between the inlet and outlet portions of the service bundle housing exhaust system, a relatively neutral or negative pressure differential can further be maintained between the interior of the service bundle housing exhaust system and the surrounding environment. Such a relatively neutral or negative pressure differential that can be maintained between the interior of the service bundle housing exhaust system and the surrounding environment can prevent particles from leaking out of the service bundle housing exhaust system through cracks, seams, and the like. Particle leakage through cracks, seams, and the like that are just proximate to the substrate has a significant potential to contaminate the substrate surface before being passed into the circulation and filtration system.

[0175] FIG. 28B depicts an enlarged, partial cutaway, front perspective view of printing system 2003. In FIG. 28B, X,Z carriage assembly 2300 may utilize an air-bearing linear slider assembly to position the X,Z carriage assembly 2300 carriage on bridge 2130. Movement of X,Z carriage assembly 2300 is in the X-axis direction over a distance defined by service bundle carrier run 2401. Service bundle carrier run 2401 is housed in service bundle housing 2410 and is an opening that allows movement of optical cables, electrical cables, wires, and tubing bundled into a service bundle that may be connected to printhead assembly 2500, for example, but not limited to, printhead assembly 2500. Given the size and complexity of various service bundles, various motion systems often require a service bundle carrier to manage the service bundle as it moves with the motion system. In that regard, service bundle carrier 2430 is shown housed in service bundle housing 2410 in FIG. 28B. During printing, as the carriage assembly moves to precisely position the printhead assembly in the X-axis direction relative to the substrate positioned below it, the movement of the service bundle, which may include cables, wires, tubing, and the like, as well as the movement of the service bundle carrier itself, can generate particulate matter just proximate to the substrate positioned below the service bundle housing. The movement of the service bundle carrier can also compress an air volume in a piston-like manner as it moves within the service bundle housing, creating a positive pressure that can allow particulate matter formed from particle-generating components associated with the service bundle carrier to escape, for example, through the carrier run 2401. Such particulate matter just proximate to the substrate has a significant potential to contaminate the substrate surface before being passed into the circulation and filtration system. Therefore, the service bundle housing exhaust system can be a component of various embodiments of a particle control system for a gas enclosure system that can ensure a substantially low-particle printing environment.

[0176] In Figure 28B, the service bundle housing top surface 2402 is shown with a set of slots 2414 that form a slotted top surface. For various embodiments of the service bundle housing exhaust system 2400 of Figure 28B, there are two requirements for such a system to ensure that particulate matter formed from particle-generating components associated with the service bundle carrier is passed into the circulation and filtration system: 1) the exhaust flow through the service bundle housing exhaust system should be greater than the volume change on the gas compression side of the service bundle carrier as it moves within the service bundle housing, and 2) there should be an even distribution of constant exhaust flow that effectively purges the service bundle housing volume. Various embodiments of the service bundle housing exhaust system of the present teachings ensure that these two requirements are met.

[0177] For example, as depicted in FIG. 29A , various embodiments of the service bundle housing exhaust system can include a service bundle housing 2410 that can be used to house a service bundle carrier 2430. In FIG. 29A , the service bundle carrier 2430 is depicted as a segmented flexible chain-type service bundle carrier; various other types of service bundle carriers that can be used can behave similarly, thereby requiring the use of various embodiments of the service bundle housing exhaust system of the present teachings. The service bundle carrier run 2401 is an opening that can allow particulate matter formed from particle-generating components associated with the service bundle carrier to escape, for example, from the service bundle housing as a result of positive pressure generated by the movement of the service bundle carrier. The service bundle housing exhaust system 2420 can be maintained at a positive pressure that can ensure that particle-generating components associated with the service bundle carrier can be exhausted into the gas circulation and filtration system through a first duct 2422 of the service bundle housing exhaust plenum and a second duct 2424 of the service bundle housing exhaust plenum. A set of service bundle housing slots 2412 formed in the service bundle housing top surface 2402 as shown in FIG. 29A can ensure an even distribution of constant exhaust flow that effectively purges the volume of the service bundle housing 2410.

[0178] The service bundle housing slots 2412 are shown in FIG. 29A formed across the top side 2402 of the service bundle housing, although it can be understood that a set of slots can be located on various surfaces of the service bundle housing, as depicted in FIG. 29B. As depicted in FIG. 29B, a set of slots can be located on the bottom side 2404 of the service bundle housing (set I), the first side 2406 of the service bundle housing (set II), and the second side 2408 of the service bundle housing (set III). Also, as depicted in FIG. 29C, the slots can be a type of opening to promote even distribution of a constant exhaust flow to effectively purge the service bundle housing volume, although openings with various shapes, aspect ratios, and locations can be used. As shown in FIG. 29C , substantially circular openings, such as first service bundle housing opening 2411 and second service bundle housing opening 2413, depicted as being formed on the top side 2402 of the service bundle housing, can be used to promote even distribution of the constant discharge flow to effectively purge the service bundle housing volume. An alternative arrangement of the substantially circular openings can be on the ends of the service bundle housing, as depicted in FIG. 29C . In FIG. 29C , first service bundle housing opening 2411 and second service bundle housing opening 2413, depicted as being formed on the first end 2415 of the service bundle housing and the second end 2417 of the service bundle housing, respectively, can be used to promote even distribution of the constant discharge flow to effectively purge the service bundle housing volume. Additionally, various embodiments of the service bundle housing may have a first service bundle carrier 2401 and a second service bundle carrier run 2407. The service bundle housing top surface 2402 may have a first set of slots 2412 and a second set of slots 2414 proximate the first service bundle carrier 2401 and the second service bundle carrier run 2407, respectively, which may be used to promote an even distribution of a constant exhaust flow to effectively purge the service bundle housing volume.Finally, as shown in FIG. 27B, when a service bundle housing exhaust system includes a single component housing, effective exhaust gas flow considerations can promote uniform distribution of consistent exhaust flow.

[0179] Various embodiments of the gas enclosure system of the present teachings, such as those depicted in FIGS. 30A / 30B-32A / 32B, can have features such as those previously discussed herein with respect to FIGS. 22, 23, and 24 regarding gas circulation and filtration systems that can promote laminar flow and thorough turnover of the gas atmosphere within the enclosure, thereby ensuring that a substantially low-particle environment for suspended particulate matter can be maintained. As previously discussed herein, the circulation and filtration systems for maintaining low suspended particulate matter specifications are part of the particulate matter control system for various embodiments of the gas enclosure system of the present teachings. The particle control system of the present teachings can also include a low-particle-generating X-axis motion system that utilizes air bearings and a service bundle housing exhaust system. Various embodiments of the low-particle-generating X-axis motion system that utilizes air bearings can virtually eliminate particulate matter generation. Furthermore, various embodiments of the service bundle housing exhaust system can be utilized to ensure that particulate matter generated just proximate to the substrate during the printing process can be contained and then passed into the circulation and filtration system for removal. Additionally, as depicted in Figures 30A / 30B-32A / 32B, various embodiments of the particle control system of the present teachings can have a printhead assembly exhaust system to control particulate matter formed by various devices, apparatus, service bundles, and the like that can be positioned proximate to the substrate during the printing process.

[0180] 30A / 30B depict a gas enclosure system 509, while FIG. 31B depicts gas enclosure system 510, and FIGS. 32A / 32B depict gas enclosure system 511, all of which may have features as previously described with respect to FIGS. 22 and 23, as shown. Gas enclosure systems 509-511 may have circulation and filtration system 1500, gas purification system 3130, and thermal conditioning system 3140. Circulation and filtration system 1500 may include piping assembly 1501 and fan filter unit assembly 1502. Piping assembly 1501 may separate inert gas from the interior through fan filter unit assembly 1502 to be recirculated to the exterior through gas purification system 3130 by effectively defining space 1580, which is effectively a conduit in fluid communication with gas purification system 3130. Space 1580 can be in fluid communication with gas purification system 3130 (FIGS. 12 and 13) through gas purification outlet line 3131 and gas purification inlet line 3133. Such circulation systems, including various embodiments of piping systems such as those described with respect to FIGS. 16-18, provide substantially laminar flow, minimize turbulence, and facilitate circulation, conversion, and filtration of particulate matter in the gas atmosphere within the interior of the enclosure and provide circulation through the gas purification system external to the gas enclosure assembly.

[0181] Additionally, the gas enclosure systems 509-511 depicted in FIGS. 30A / 30B-32A / 32B, respectively, can have a printhead assembly exhaust system 2600 that can be utilized to contain and exhaust particulate matter formed by various assemblies associated with the printing system 2003. For various embodiments of the gas enclosure systems 509, 510, and 511, the printhead assembly exhaust system 2600 can house, for example, but not limited to, the carriage assembly 2300 onto which the printhead assembly 2500 can be affixed, as depicted in FIGS. 30A / 30B, 31A / 31B, and 32A / 32B, respectively. Such a moving plate can utilize friction bearings, which can generate particles during operation of the OLED printing system, as previously discussed herein. Additionally, the carriage assembly can be used to mount devices such as ultraviolet lamp assemblies or heat source assemblies for curing the encapsulation layer, as previously discussed herein. Either the ultraviolet lamp or the heat source may require cooling using a fan.

[0182] Thus, printhead assembly exhaust system 2600 of gas enclosure systems 509, 510, and 511 may be part of a particulate matter control system used to contain and exhaust particulate matter formed by various devices, apparatus, service bundles, and the like that may be positioned proximate to a substrate during a printing process. Various embodiments of printhead assembly exhaust systems, such as printhead assembly exhaust system 2600 of gas enclosure systems 509, 510, and 511, may ensure that a positive pressure differential can be maintained between the inlet and outlet portions of the printhead assembly exhaust housing to exhaust particles generated by various components of the printhead assembly into a gas circulation and filtration system. For various embodiments of the printhead assembly exhaust system, a positive pressure differential can be maintained between the inlet and outlet portions of the printhead assembly exhaust housing to exhaust particles generated by various components of the printhead assembly into a dead space. As discussed in more detail later herein, a positive pressure differential can be created to exhaust particles generated by various components of the printhead assembly through the use of fans and other system components, such as, but not limited to, providing fluid communication between the printhead assembly exhaust housing and a circulation and filtration system.

[0183] For various embodiments of the printhead assembly ejection system, see the printhead In addition to maintaining a positive pressure differential between the inlet and outlet portions of the exhaust assembly, a relatively neutral or negative pressure differential can be further maintained between the interior of the printhead exhaust assembly and the surrounding environment. Such a relatively neutral or negative pressure differential that can be maintained between the interior of the printhead exhaust assembly and the surrounding environment can prevent particles from escaping from the printhead exhaust assembly through cracks, seams, and the like. Particle leakage through cracks, seams, and the like just proximate to the substrate has a significant potential to contaminate the substrate surface before being passed into the circulation and filtration system.

[0184] As depicted in FIGS. 30A and 30B , the service bundle housing 2410 can be supported on the bridge 2130 of the printing system 2003. As previously discussed herein with reference to the printing system 2000 of FIG. 10B , the carriage assembly 2300 can have components for controlling XZ-axis movement, including a Z-axis movement plate onto which the printhead assembly 2500 can be affixed. The printhead assembly exhaust system housing 2610 can be in fluid communication with the service bundle housing 2410, for example, but not limited to, a first conduit 2612 of the printhead assembly exhaust system. The service bundle housing 2410 can be in fluid communication with the piping assembly 1501 through a second conduit 2614 of the printhead assembly exhaust system, which can be in fluid communication with, for example, but not limited to, the second piping conduit 1574. The printhead assembly exhaust system 2600 of FIGS. 30A and 30B , which may contain components that are at risk of generating particles, such as a moving plate, may have at least one fan, such as fan 2620, to facilitate gas movement through the printhead assembly exhaust system 2600 and into the service bundle housing 2410. In that regard, the entire air contained in the printhead assembly exhaust system 2600 and the service bundle housing 2410 may be effectively filtered by the circulation and filtration system 1500, as depicted in FIG.

[0185] According to the present teachings, particulate matter that collects in the dead space away from a substrate placed on a substrate support apparatus cannot be recirculated within the gas enclosure system. In that regard, various embodiments of the gas enclosure system depicted in Figures 31A / 31B and 32A / 32B can be utilized to direct particulate matter into the piping system and into the dead space. During routine gas enclosure system maintenance, such particulate matter can be removed from the dead space.

[0186] In that regard, for various embodiments of gas enclosure systems, such as gas enclosure system 510 of FIGS. 31A and 31B , service bundle housing 2410 can be in fluid communication with circulation and filtration system 1500. As depicted in FIG. 31B , printhead assembly exhaust system housing 2610 can be in fluid communication with service bundle housing 2410, such as, but not limited to, printhead assembly exhaust system first conduit 2612. Service bundle housing 2410 can be in fluid communication with printhead assembly exhaust system second conduit 2614, which can have an outlet end proximate to second piping inlet 1572 of piping assembly 1501. In that regard, printhead assembly exhaust system second conduit 2614 can be in fluid communication with the piping assembly via second piping conduit 1574. The first conduit 2612 of the printhead assembly exhaust system can have a fan, such as fan 2620, to facilitate gas movement through the first conduit 2612 of the printhead assembly exhaust system. Additionally, the second conduit 2614 of the printhead assembly exhaust system can have a fan 2622 to facilitate gas movement through the printhead assembly exhaust system 2614 so that particles contained by the printhead assembly exhaust system 2600 and the service bundle housing 2410 can be effectively filtered by the circulation and filtration system 1500, as depicted in FIG. 31A . For various embodiments of gas enclosure systems, such as the gas enclosure system 510 of FIGS. 31A and 31B , any particulate matter that is not forced into the second piping inlet 1572 will have a trajectory toward the dead space 1590.

[0187] As depicted for the gas enclosure system 511 in FIGS. 32A and 32B , the service bundle housing 2410 can be in fluid communication with the circulation and filtration system 1500. As depicted in FIG. 32B , the printhead assembly exhaust system housing 2610 can be in fluid communication with the service bundle housing 2410, for example, but not limited to, the printhead assembly exhaust system first conduit 2612, which can have a fan such as fan 2620 to facilitate gas movement through the printhead assembly exhaust system first conduit 2612. The service bundle housing 2410 can be in fluid communication with the printhead assembly exhaust system second conduit 2614, which can have a filter head 2616. The filter head 2616 can filter particulate matter emanating from the printhead assembly exhaust system 2600 into the service bundle housing 2410 and can direct the low-particle gas flow from the filter head 2616 directly into the gas enclosure system 511. In that regard, the second conduit 2614 of the printhead assembly exhaust system can exhaust the low-particle gas into the gas enclosure system 511, which can then be circulated through the circulation and filtration system 1500 of the gas enclosure system 511, as depicted in FIG. 32A.

[0188] Various gas enclosure systems of the present teachings, such as gas enclosure system 501 of FIG. 12 and gas enclosure and gas enclosure system 502 of FIG. 13, can utilize various gas enclosures, for example, but not limited to, gas enclosure 100 of FIG. 1A and gas enclosure 1000 of FIG. 9. Additionally, various gas enclosures, such as gas enclosure 100 of FIG. 1A and gas enclosure 1000 of FIG. 9, can house various printing systems, such as printing system 2000 of FIG. 10B, printing system 2002 of FIG. 26, and printing system 2003 of FIG. 28A. For the gas enclosure systems and methods of the present teachings, monitoring the controlled environment of the gas enclosure is an important aspect of maintaining the controlled environment of the gas enclosure.

[0189] One parameter of the controlled environment that can be monitored is the effectiveness of particulate matter control. System validation, as well as ongoing in-situ system monitoring, can be performed for both airborne and on-substrate particle monitoring.

[0190] A determination of suspended particulate matter can be made on various embodiments of the gas enclosure system prior to the printing process for system validation, for example, using a portable particle counting device. In various embodiments of the gas enclosure system, a determination of suspended particulate matter can be made in situ while the substrate is being printed as an ongoing quality check. For various embodiments of the gas enclosure system, a determination of suspended particulate matter can be made before the substrate is printed as well as in situ while the substrate is being printed for system validation.

[0191] FIG. 33 depicts a device for measuring suspended particulate matter. According to the present teachings, various embodiments of the particle counter 800 of FIG. 33 can be handheld or otherwise portable. As depicted in FIG. 33 , the particle counter 800 can have a power button 810 and a display 812 for real-time visual monitoring of various parameters, such as the particle size being monitored and the current count of particulate matter of that size. Portable particle counters of the present teachings can have multiple channels for monitoring several particle size ranges during an analysis. As a non-limiting example, the display 812 of the particle counter 800 is depicted monitoring three distinct particle size ranges. For various embodiments of the systems and methods of the present teachings, monitoring particles sized within a size range of approximately ≧0.3 μm can be useful for monitoring system quality, as a spike in particles within that range can be an early indicator of a malfunctioning filtration system, for example, in a gas enclosure system. Various embodiments of particle counters according to the present teachings can have a cable or wireless connection (not shown) from the particle counter to a computer, which can provide, by way of non-limiting example, ongoing collection and storage of data from the particle counter. Particle counter 800 can have an inlet nozzle 814 for drawing an air sample into particle counter 800. Various embodiments of particle counters for measuring suspended particulate matter can have an isokinetic sampling probe, such as sampling probe 816 of FIG. 33, which can reduce counting errors related to sample flow rate and the aerodynamics of particles, particularly small particles. To obtain accurate results regarding particulate matter in a flow rate, the sample flow through the sampling system should be such that the velocity at the sampling point inlet is the same as the velocity of the gas flow at that point. An isokinetic sampling probe can have an inlet probe 815 that can be attached to inlet nozzle 814 using sampling probe connector 817. For various embodiments of sampling probe 816, sampling probe connector 817 can be a section of flexible tubing.For sampling in various embodiments of the gas enclosure system of the present teachings, the inlet probe 815 of the sampling probe 816 can face directly into the airflow.

[0192] Although various commercial particle counters can be based on different measurement principles, which can include light obscuration, direct imaging, and light scattering, measurements based on light scattering from particles are suitable for yielding information of interest, including particle size. In principle, light scattering can be used to determine particle sizes down to about 1 nm.

[0193] FIG. 34 is a schematic diagram of a light scattering-based particle counter detector 830. A light scattering-based particle counter detector can have a source of electromagnetic radiation of a known wavelength in a known wavelength range, such as light source 820. For various embodiments of particle counter detector 830, light source 820 can be a laser source emitting light of a known wavelength. For various embodiments of particle counters, particularly, but not exclusively, for handheld and portable particle counting devices, light source 820 can be a light emitting diode (LED) emitting light of a known wavelength between about 600 nm and about 850 nm. Emitted source light 821 can be focused at a detection region 822 of a flow path 824, depicted in FIG. 34 as a top cross-sectional view. Any particles in detection region 822 can scatter light, producing forward scattered light 823, or light scattered in several angular directions, including perpendicular to the direction of emitted source light 821, as depicted for light path 825. Light scattered at right angles by particles in detection region 822 can be focused using focusing lens 826 and filtered using at least one optical filter, e.g., a spatial or optical bandpass filter, or a combination thereof, before being detected by detector 828, which can be various types of photometric detectors, e.g., based on photodiode technology. Various embodiments of the particle counter can be calibrated using a calibration standard, such as an aerosol, having particulate matter with a defined distribution of particles in various size ranges, with each size range having a defined concentration.

[0194] For example, various commercial particle counters based on light scattering can detect airborne particle sizes in the range of about ≥0.3 μm to about ≥10 μm and generally report the number of particles of a particular size per volume of air, expressed as cubic feet or cubic meters. Various commercial particle counters can count up to about 1 million to about 3 million particles of a particular size. In that regard, various commercial calibration standards define a distribution of particle coverage from about ≥0.3 μm to about ≥10 μm, e.g., a detection limit of up to about 1 million to about 3 million particles for each population of particles. The particle counter may have a bimodal or trimodal distribution of species covering that range, with concentrations determined by the channel. As previously discussed herein, various particle counters for determining suspended particulate matter can have multiple channels for monitoring several size ranges. While shown with one light source and one detector, various embodiments of particle counters for determining suspended particulate matter can have more than one light source and multiple detectors at various positions for monitoring light scattered at various angles. Such airborne particle counters can monitor and report over a wide dynamic size range of suspended particulate matter, from about ≧0.1 μm to about ≧10.0 μm.

[0195] FIG. 35 is a schematic representation using particle counter icons 800A-800D intended to convey where various embodiments of particle counting devices can be located relative to a low-particle zone of a printing system proximal to the substrate. The gas enclosure system 512 of FIG. 35 can have components as previously described herein for the gas enclosure systems 500-511, including, but not limited to, the gas enclosure assembly 1100 and a thermal conditioning system 3140 that can be integrated with a circulation and filtration system, such as that shown by the fan-filter unit 1552 proximal to the heat exchanger 1562. The gas enclosure system 512 of FIG. 35 can have an outlet line 3131 and an inlet line 3133 to a gas purification system (not shown) and can house the printing system 2004. The printing system 2004 can have a base 2101 upon which the substrate support apparatus 2200 can rest. The printing system 2004 may additionally have a bridge 2130 that may have a first carriage assembly 2300A and a second carriage assembly 2300B mounted thereon. The printing system 2004 may also have a service cable housing 2410 for housing a service cable (not shown).

[0196] With reference to FIG. 35 , at least one particle counter can be positioned or mounted on the service bundle housing 2410, as depicted by particle counter icon 800A, for example, depicted in the laminar flow of the fan filter unit 1552. A particle counter so positioned in the laminar flow of gas from the fan filter unit can enable monitoring of the effectiveness of the gas enclosure system's filtration system. Additionally, the bridge 2130 of the printing system 2004 can support a first X-, Z-axis carriage assembly 2300A, on which the printhead assembly 2500 can be mounted. The second X-, Z-axis carriage assembly 2300B can have at least one particle counter mounted thereon, as depicted by particle counter icon 800B. Monitoring in a location proximal to various printing devices and apparatus, such as the carriage assembly, can be useful for monitoring various particle generating sources, such as the service bundle. A particle counter mounted as depicted by particle counter icon 800C can be useful for procedure development and gas enclosure system validation runs. A particle counter mounted as depicted by particle counter icon 800D can be useful for procedure development and gas enclosure system validation runs, as well as in-situ monitoring of airborne particulate matter during the printing process.

[0197] According to various systems and methods of the present teachings, a particle counting device can be mounted or located on a substrate support apparatus to measure particles under defined conditions in the adjacent area where the substrate may be located during printing. For example, as depicted in FIG. 35 , a particle counter can be mounted or located on the substrate support apparatus 2200, as indicated by the location of particle counter icon 800C. In various embodiments of the systems and methods of the present teachings, monitoring of particulate matter using a particle counter mounted or located on the substrate support apparatus can be performed for various types of procedure development or gas enclosure system validation execution studies. As another non-limiting example, a particle counter can be located at the location of particle counter icon 800D. As shown, a particle counter can be mounted on the side of the substrate support apparatus 2200. By using a particle counter with a sampling probe having a flexible connector, such as particle counter 800 of Figure 33 with sampling probe 816, a particle counter mounted on the side of the substrate support apparatus can have the sampling probe positioned exactly at the height of the substrate.

[0198] A particle counter mounted on the side of the substrate support apparatus, as indicated by particle counter icon 800D, can be useful for procedure development and gas enclosure system validation runs, as well as in-situ monitoring of airborne particulate matter during the printing process. For example, in FIG. 36, a printing system 2003 such as that previously described with respect to FIGS. 26 and 28A can have an X-axis carriage assembly 2300 mounted on a bridge 2130, which can also include a Z-axis moving plate 2310 for Z-axis positioning of the printhead assembly 2500. In that regard, various embodiments of the carriage assembly 2300 can provide precise X, Z positioning of the printhead assembly 2500 relative to the substrate 2050. For various embodiments of the printing system 2003, the X-axis carriage assembly 2300 can utilize a linear air bearing motion system that is inherently low particle generating. The printing system 2003 of FIG. 36 can have a service bundle enclosure exhaust system 2400 for containing and exhausting particles generated from the service bundle, which can include a service bundle enclosure 2410 for housing the service bundle. In accordance with the present teachings, the service bundle can be operatively connected to the printing system to provide various optical, electrical, mechanical, and fluid connections needed to operate various devices and apparatus within the gas enclosure system, including, but not limited to, various devices and apparatus associated with the printing system. The printing system 2003 of FIG. 36 can have a substrate support apparatus 2250 for supporting a substrate 2050, which can be precisely positioned in the Y-axis direction using a Y-axis positioning system 2355. Both the substrate support apparatus 2250 and the Y-axis positioning system 2355 are supported by the printing system base 2101.

[0199] For the printing system 2003 of FIG. 36 , a precision XYZ motion system can have various components for positioning a substrate mounted on a substrate support apparatus 2250 relative to a print head assembly 2500, which can include a Y-axis motion assembly 2355 as well as an X-axis carriage assembly 2300. The substrate support apparatus 2250 can be mounted on the Y-axis motion assembly 2355 and moved on a rail system 2360 using, for example, but not limited to, a linear bearing system utilizing either mechanical or air bearings. For various embodiments of a gas enclosure system, the air bearing motion system helps facilitate frictionless transport of a substrate disposed on the substrate support apparatus 2250 in the Y-axis direction. The Y-axis motion system 2355 can also optionally use dual rail motion, again provided by a linear air bearing motion system or a linear mechanical bearing motion system. Other precision XYZ motion systems can be used in accordance with the present teachings, such as, for example, but not limited to, various embodiments of a three-axis gantry system. For example, various embodiments of a three-axis gantry system can have an X, Z carriage assembly mounted on a gantry bridge for precision X, Z axis movement, which allows the gantry to be precisely moved in the Y axis.

[0200] According to various systems and methods of the present teachings, the printing system 2003 of FIG. 36 can have a particle counter 800 mounted on the side of the substrate support 2250 such that the isokinetic sample probe 816 is approximately level with the substrate 2050. While FIG. 36 depicts the particle counter 800 on the front of the substrate support, it is possible to mount one or more particle counters at various locations on the substrate support to effectively monitor airborne particulate matter proximate the substrate. Additionally, for various embodiments of the systems and methods, Additional particle counters can be mounted or positioned elsewhere, as illustrated in FIG.

[0201] According to various embodiments of the gas circulation and filtration systems contained in various embodiments of the gas enclosure system of the present teachings, continuous measurements of airborne particles can be performed in the gas enclosure system. In various embodiments of the gas enclosure system of the present teachings, such measurements can be performed in a fully automated mode and continuously reported to an end user, for example, through a graphical user interface (GUI). In various embodiments of the gas enclosure system of the present teachings, measurements of airborne particulate matter can be performed at a desired target location, as depicted in FIG. 35. Output from each of the particle counters located within the gas enclosure can be reported to an end user, for example, through a GUI. For example, the desired target region can be airborne particulate matter over a substrate support device, such as a chuck or floating table, just proximal to the substrate, as depicted in FIG. 36.

[0202] In that regard, continuous monitoring of various embodiments of the gas enclosure system of the present teachings confirms that particles of about ≧2 μm in size can be maintained at less than about one particle in that size range over a print cycle. For various embodiments of the gas enclosure system of the present teachings, particles of about ≧2 μm in size can be maintained at less than about one particle in that size range over a period of at least about 24 hours. For various embodiments of the gas enclosure system of the present teachings, particles of about ≧0.3 μm in size can be maintained at less than about three particles in that size range over a print cycle. For various embodiments of the gas enclosure system of the present teachings, particles of about ≧0.3 μm in size can be maintained at less than about three particles in that size range over a period of at least about 24 hours. According to the present teachings, particulate matter measurements obtained from different locations in various embodiments of a gas enclosure system of the present teachings over a duration of at least about 24 hours are reported as an average of 0.001 particles ≧2 μm and 0.02 particles ≧0.5 μm.

[0203] For example, FIGS. 37A and 37B depict the results of long-term measurements performed on various embodiments of the gas enclosure system of the present teachings. FIG. 37A depicts two tests performed on different days. Such tests were performed in a gas enclosure system, such as those shown in FIGS. 12 and 13, maintained in an inert nitrogen environment. Measurements were performed proximate to a substrate support device, such as a chuck or floating table, as depicted in FIG. 36. During the test period, the gas enclosure system was in continuous use for a sequence that included printing, maintenance, and idle. In Test 1, the duration of the real-time measurements was approximately 16 hours. During that time, a total of two particles approximately ≥ 2 μm in size were measured: one at approximately 5 hours and one near the end of the test period. For Test 2, which had a duration of approximately 10 hours, no particles in this size range were measured. FIG. 37B depicts measurements from Test 3, performed on a system on yet another day over a period of more than 8 hours, for particles approximately ≥ 0.5 μm in size. During this test period, a gas enclosure assembly window, such as window 130 in FIG. 1A, was periodically opened at approximately 2 hours (reference number I.), approximately 6.5 hours (reference number II.), and approximately 7 hours (reference number III.). During these periods of transient gas enclosure system exposure to the ambient environment, particulate matter measurements can be observed to spike and then quickly re-establish to a baseline value of approximately ≦1 particle within the size range.

[0204] For various embodiments of the systems and methods of the present teachings, the suspended particulate matter measured in a gas enclosure system is less than about 3 particles / ft for particles of about ≧0.3 μm, less than about 1 particle / ft for particles of about ≧0.5 μm, and less than about ≧1.0 For micron particles, the concentration may be less than about 0 particles / ft. In that regard, various embodiments of the gas circulation and filtration system may be designed to provide a low-particle inert gas environment for suspended particulate matter that meets the standards of International Standards Organization Standard (ISO) 14644-1:1999, "Cleanrooms and associated controlled environments—Part 1: Classification of air cleanliness," as specified by Class 1 through Class 5, and may even meet or exceed the standards set by Class 1.

[0205] Such rapid system recovery according to various embodiments of the circulation and filtration system of the present teachings, as demonstrated by the data presented for FIG. 37B, is additionally depicted in the graph of FIG. 38, in which particles of a size of about ≧2 μm were monitored proximate to a substrate support device, such as a chuck or floating table. As can be seen in the graph of FIG. 38, recovery back to a baseline level of about ≦1 particle in that size range occurred in less than 3 minutes.

[0206] Determining the on-substrate distribution of particulate matter on a substrate can be performed for various embodiments of the gas enclosure system before a substrate is printed for system validation, for example, using a test substrate. For various embodiments of the gas enclosure system, determining the on-substrate distribution of particulate matter can be performed in situ while a substrate is being printed as an ongoing quality check. For various embodiments of the gas enclosure system, determining the on-substrate distribution of particulate matter can be performed for system validation before a substrate is printed as well as in situ while a substrate is being printed.

[0207] Figure 39 depicts an on-board detection scheme based on light scattering that can have essentially the same components as previously described for the particle counter detector 830 of Figure 34 for a detection system for suspended particulate matter.

[0208] In FIG. 39, an on-substrate particle counter detection system 860 based on light scattering can have an electromagnetic radiation source of known wavelengths in a known wavelength range, such as light source 850. For various embodiments of on-substrate particle counter detection system 860, light source 850 can be a laser source emitting light of a known wavelength between about 600 nm and about 850 nm. The emitted source light 851 is depicted by ray tracing as it interacts with particles 852 on substrate 854. For various embodiments of the systems and methods of the present teachings, the substrate can be a test substrate, such as a silicon wafer. Given the history of on-substrate particle determination, which evolved from the semiconductor industry, particle determination on silicon wafers is a widely accepted testing method. Furthermore, silicon wafers can have attributes such as having a reflective surface that are favorable for on-substrate detection systems based on light scattering. Additionally, silicon wafers are substantially conductive materials that can be grounded. Having an electrically neutral substrate surface is important for obtaining unbiased sampling of particle deposition on the substrate. It is not uncommon for particulate matter to carry an electric charge, which can cause charged surfaces to give false positive or false negative results depending on whether the interaction between the charged particle and the charged surface is attractive or repulsive.

[0209] For a substrate having a reflective surface, such as a silicon wafer test substrate, the emitted source light 851 can be reflected, as shown by reflected light ray 853, which can also interact with particles 852 on the substrate surface 854 to produce scattered light, as depicted by scattered light 855. As previously discussed herein for the case of airborne particle detection based on light scattering, such as particle counter detector 830 of Figure 34, light can be scattered at several angular orientations, including perpendicular to the direction of the emitted source light 851, as depicted for scattered light 855 entering i...

Claims

1. 1. A system comprising: a gas enclosure defining an interior, the gas enclosure configured to maintain a controlled gas environment within the interior; a printing system disposed within the gas enclosure; and a substrate support apparatus disposed within the interior of the gas enclosure; a gas circulation system operably coupled to the gas enclosure, the gas circulation system comprising: a gas moving device positioned to flow gas along a path from above the printing system downward within the gas enclosure toward the substrate support apparatus; a plurality of piping assemblies disposed within the gas enclosure and in fluid communication with the gas transfer device, each of the piping assemblies including an inlet duct in fluid communication with at least one riser, for recirculating gas within the gas enclosure from the inlet duct disposed at the bottom, around the periphery of the interior, and back to the gas transfer device; a particulate filter apparatus downstream of the gas transfer device; The system comprises: The system further comprising a gas purification system in fluid communication with the gas enclosure for supplying purified gas to the interior of the gas enclosure.

2. The system of claim 1 , further comprising a thermal regulation system in thermal communication with the gas circulation system.

3. The system of claim 2 , wherein the thermal regulation system comprises at least one of a heat exchanger and a fluid cooling device.

4. The system of claim 1 , wherein the gas circulation system is configured to provide a laminar flow of gas within the gas enclosure.

5. The system of claim 1 , wherein the gas moving device is a fan.

6. The printing system includes: a bridge extending across the substrate support; a carriage assembly movably mounted relative to the bridge, the carriage assembly being movable along the bridge in an X-axis direction; a plurality of air bearings providing bearing surfaces between the carriage assembly and the bridge; a printhead coupled to the carriage assembly; The system of claim 1 , comprising:

7. The system of claim 6 , further comprising a Z-axis translation plate coupled to the carriage assembly, the print head being mounted to the Z-axis translation plate.

8. The system of claim 6 , further comprising a brushless linear motor operably coupled to the carriage assembly to move the carriage assembly along the bridge.

9. The system of claim 6 , further comprising a Y-axis motion system configured to move the substrate support in a Y-axis direction.

10. an exhaust housing enclosing a printhead assembly of the printing system; a filter in fluid communication with the exhaust housing; The system of claim 1 , comprising:

11. 11. The system of claim 10, further comprising another gas moving device positioned to move gas from the exhaust housing through a service bundle duct that routes a service bundle of the printhead assembly.

12. The system of claim 1 , wherein the printing system comprises an inkjet printing assembly.

13. The printing system is configured to print an active material on a surface of a substrate supported by the substrate support apparatus. The system of claim 1 configured to deposit a substrate material.

14. 1. A system comprising: a gas enclosure defining an interior, the gas enclosure configured to maintain a controlled gas environment within the interior; a printing system disposed within the gas enclosure; and a substrate support apparatus disposed within the interior of the gas enclosure; a gas circulation system operably coupled to the gas enclosure, the gas circulation system comprising: a gas moving device positioned to flow gas along a path from above the printing system downward within the gas enclosure toward the substrate support apparatus; a plurality of piping assemblies disposed within the gas enclosure and in fluid communication with the gas transfer device, each of the piping assemblies being disposed around the periphery of the interior of the gas enclosure and including an inlet duct in fluid communication with at least one riser, for recirculating gas within the gas enclosure from the inlet duct disposed at the bottom, along the periphery, and back to the gas transfer device; a particulate filter apparatus downstream of the gas transfer device; The system comprises: The system further comprising a gas purification system in fluid communication with the gas enclosure for supplying purified gas to the interior of the gas enclosure.

15. 15. The system of claim 14, further comprising a cover for the gas transfer device, the cover comprising a gas inlet and a gas outlet for circulating an inert gas through the gas purification system.

16. The system of claim 14 , wherein each of the piping assemblies is attached to an interior wall of the gas enclosure.

17. The system of claim 16 , wherein at least one of the piping assemblies houses a service bundle within the piping assembly.

18. The system of claim 14 , wherein each of the inlet ducts has a plurality of openings along a bottom surface.

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