GLASS-BASED SEALING
FIELD OF INVENTION
[001] The invention disclosed herein relates, in general, to a sealing mechanism. More specifically, the present invention relates to a glass-to-glass-to-glass sealing mechanism.
BACKGROUND
[002] Various devices and structures having environmentally sensitive material as a component are always in need for protection fi-om the ambient medium and matters external to the device. For example, various devices like aircrafts, display devices, solar cells use environmentally sensitive material encapsulated between substrates.
[003] For example, OLED display, lighting and photovoltaic cell panels face problem of penetration of water / oxygen-gas into a device with passage of time, adversely impacting the life and efficient functioning of the devices.
[004] Conventionally, to ensure that the devices are properly sealed, an edge-sealant, or filled epoxy are used for sealing purposes. However, such sealing methods use randomly oriented fibers in the sealants and in some cases also has a high percentage of matrix material around the fibers, resulting in an increased chance of permeation of matter external to the device.
Another problem with the conventional OLED designs is that to accommodate getter material, additional space is required and expensive pocketed glass is used. Further, the seal thickness is limited as much as possible to restrict permeation, however, to use flat glass in combination with a getter only a thick impermeable seal is a solution.
[005] In light of the above discussion, there is a need for a sealing method that decreases the chances of permeation of matter external to the device like water and oxygen, and at the same time overcomes one or more of the above drawbacks in the state of the art.

BRIEF DESCRIPTION OF FIGURES
[006] The features of the present invention, which are believed to be novel, are set forth with particularity in the appended claims. The invention may best be understood by reference to the following description, taken in conjunction with the accompanying drawings. These drawings and the associated description are provided to illustrate some embodiments of the invention, and not to limit the scope of the invention.
[007] FIG la is a diagrammatic illustration of an exemplary structure that encapsulates a functional layer made of environment-sensitive materials in between two glass substrates, in accordance with an embodiment of the present invention;
[008[ FIG lb is a diagrammatic illustration of another exemplary structure that encapsulates a plurality of functional layers made of one or more environment-sensitive materials in between two glass substrates, in accordance with an embodiment of the present invention;
[009] FIG 2 is a diagrammatic illustration of a top view of an exemplary glass substrate illustrated in FIGs. la and lb, in accordance with an embodiment of the present invention;
[0010] FIG 3 is a diagrammatic illustration of an exemplary structure that encapsulates a functional layer made of environmentally sensitive materials in between two glass substrates and further including a glass-to-glass-to-glass integrated seal between the two glass substrates, in accordance with an embodiment of the present invention;
[0011] FIG 4a is a diagrammatic illustration of a cross-sectional view of an exemplary sealing structure, in accordance with an embodiment of the present invention; and
[0012] FIG 4b is a diagrammatic illustration of a cross-sectional view of another exemplary sealing structure, in accordance with another embodiment of the present invention; and
[0013] Those with ordinary skill in the art will appreciate that the elements in the figures are illustrated for simplicity and clarity and are not necessarily drawn to scale. For example, the

dimensions of some of the elements in the figures may be exaggerated, relative to other elements, in order to improve the understanding of the present invention.
[0014] There may be additional structures described in the foregoing application that are not depicted on one of the described drawings. In the event such a structure is described, but not depicted in a drawing, the absence of such a drawing should not be considered as an omission of such design from the specification.
SUMMARY
[0015] The instant exemplary embodiments of the present invention provide a device that includes an integral glass-to-glass-to-glass sealing structure.
[0016] The instant exemplary embodiments of the present invention provide a device that substantially reduces the chances of permeation of matter external to the device to cause adverse affect to environmentally sensitive material housed in an encapsulation.
[0017] Some embodiments of the present invention provide a device having a glass-to-glass-to-glass sealing structure. The device includes a first glass substrate having a first interior surface and a substantially parallel first exterior surface. Further, the first interior surface has a first portion that is substantially proximal to a perimeter of the first interior surface. Similarly, the device also includes a second glass substrate having a second interior surface and a substantially parallel second exterior surface. Further, the second interior surface has a second portion that is substantially proximal to a perimeter of the second interior surface and corresponds to the first portion. The device also includes one or more environment-sensitive materials that are disposed between the first interior surface and the second interior surface. Further, the device is completed by a glass-to-glass-to-glass sealing structure having a plurality of substantially continuous glass fibers disposed between the first portion and the second portion. The glass fibers have a substantially circular cross-section and the glass fibers are arranged closely and substantially mutually parallel, such that the space between the glass fibers is filled with a matrix material, creating a glass-to-glass-to-glass integrated seal between the first substrate and the second substrate.

[0018] Some embodiments of the present invention provide a device having a glass-to-glass-to-glass sealing structure. The device further includes environmentally sensitive material sandwiched between two glass substrates. The glass-to-glass-to-glass sealing structure is provided between the two glass substrates and helps encapsulate the environmentally sensitive material between the two glass substrates. The glass-to-glass-to-glass sealing structure has a plurality of substantially continuous glass fibers having a substantially circular cross-section, which are arranged closely and substantially mutually parallel, such that the space between the glass fibers is filled with a matrix material, creating a glass-to-glass-to-glass integrated seal between the first substrate and the second substrate.
DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0019] Before describing the present invention in detail, it should be observed that the present invention utilizes apparatus having glass based substrates having glass to glass to glass sealing to encapsulate and protect environmentally sensitive material housed with two glass substrates, such as an organic light emitting device. Accordingly the apparatus components have been represented where appropriate by conventional symbols in the drawings, showing only specific details that are pertinent for an understanding of the present invention so as not to obscure the disclosure with details that will be readily apparent to those with ordinary skill in the art having the benefit of the description herein.
[0020] While the specification concludes with the claims defining the features of the invention that are regarded as novel, it is believed that the invention will be better understood from a consideration of the following description in conjunction with the drawings, in which like reference numerals are carried forward.
[0021] As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure. Further, the

terms and phrases used herein are not intended to be limiting but rather to provide an understandable description of the invention.
[0022] The terms "a" or "an", as used herein, are defined as one or more than one. The term "another", as used herein, is defined as at least a second or more. The terms "including" and/or "having" as used herein, are defined as comprising (i.e. open transition). The term "coupled" or "operatively coupled" as used herein, is defined as connected, although not necessarily directly, and not necessarily mechanically.
[0023] Referring now to the drawings, there is shown in FIG la, an exemplary structure 100a that encapsulates a functional layer 106a made of environment-sensitive materials in between two glass substrates 102a and 104a. This figure brings out the need for the glass-to-glass-to-glass sealing structure in accordance with an embodiment of the present invention.
[0024] The structure 100a is shown to include a first glass substrate 102a having a first interior surface and a substantially parallel first exterior surface. Similarly, a second glass substrate 102b is also illustrated having a second interior surface and a substantially parallel second exterior surface. The fianctional layer 106a made of environment-sensitive materials is disposed between the first interior surface and the second interior surface. The first glass substrate 102a and the second glass substrate 102b fiinction to provide strength to the structure 100 and are configured to receive and support functional layers made of one or more environmentally sensitive materials in between. Environmentally sensitive materials are those material that are impacted adversely on being contacted with material in the environment, for example ambient matter like water and oxygen. For example, in real life applications, when the device using such a structure is an Organic Light Emitting Device (OLED), the functional stack forming the OLED device is an example of the environmentally sensitive material.
[0025] Examples of devices in which such structures may find use in can include, but are not limited to. Organic Light Emitting Devices (OLEDs), Thin-Film Photovoltaic Devices (TF-PVs), Organic Photovoltaic Devices (OPVs), Crystalline Photovoltaic Devices, other forms of PV, displays, organic displays, aircraft components and other similar devices using a sandwich structure like the structure 100a.

[0026] Some real life examples of an OLED can include, but are not limited to, White Organic Light Emitting Diode (W-OLED), Active-matrix Organic Light Emitting Diodes (AMOLED), Passive-matrix Organic Light Emitting Diodes (PMOLED), Flexible Organic Light Emitting Diodes (FOLED), Stacked Organic Light Emitting Diodes (SOLED), Tandem Organic Light Emitting Diode, Transparent Organic Light Emitting Diodes (TOLED), Top Emitting Organic Light Emitting Diode, Bottom Emitting Organic Light Emitting Diode, Fluorescence doped Organic Light Emitting Diode (F-OLED) and Phosphorescent Organic Light Emitting Diode (PHOLED).
[0027] Similarly, examples of a TF-PV can include, but are not limited to, a thin film solar cell, an organic solar cell, an amorphous silicon solar cell, a microcrystalline silicon solar cell, a micromorph silicon tandem solar cell, a Copper Indium Gallium Selenide (CIGS) solar cell, a Cadmium Telluride (CdTe) solar cell, and the like.
[0028] Moving on, there is shown in FIG. lb, a real life application of an exemplary structure 100b, in accordance with an embodiment of the invention.
[0029] FIG lb, illustrates an OLED 100b having two glass substrates 102b and 104b that encapsulates a stack of functional layers 106b made of one or more environment-sensitive materials in between. For the purpose of the description, the invention has been described with reference to the OLED 100b; however, it should be appreciated that the structure can find utility in any of the application areas described above, without deviating from the scope of the invention.
[0030] The OLED 100b is shown to include the first glass substrate 102b on which the stack of functional layers 106b, made of environmentally sensitive material like a transparent conductive oxide, light emitting organic layers, metal electrodes etc, is deposited. The stack of functional layers needs to be protected from moisture and oxygen in addition to harmful chemicals and solvents in order to function efficiently and effectively, further highlighting the need for a proper and effective sealing mechanism.
[0031] Moving on, there is shown in FIG 2, a top view of an exemplary glass substrate (102a, 102b, 104a, 104b) illustrated in FIGs. la and lb. For the purpose of the description.

the invention has been described with reference to the first glass substrate 100b; however, it should be appreciated that the description is valid for other glass substrates as well, without deviating from the scope of the invention.
[0032] The first interior surface of the first glass substrate 102 is shown to include a first portion 202 (shaded area) proximal to a perimeter of the first glass substrate 102, and part of the remaining portion of the first glass substrate 102 is configured to receive the stack of functional layers 106a. The first portion 202 is made of multiple glass fibers, such that each glass fiber is substantially parallel to other glass fibers and each glass fiber has a pre-defined orientation direction as illustrated by double pointed arrows. In an embodiment, a continuous filament of the glass fiber at comers of the device enables best possible sealing. Further, according to other embodiments of the present invention prevents the presence of glass fiber ends
[0033] Moving on, there is shown if FIG 3, a diagrammatic illustration of an exemplary device 300 that encapsulates a functional layer 106a made of environmentally sensitive materials in between two glass substrates 102a and 104a. Further the device 300 is also shown to include a glass-to-glass-to-glass integrated seal 302 between the two glass substrates 102a and 104a. The glass-to-glass-to-glass integrated seal 302 is impermeable to matter external to the device 300 and forms an enclosure along with the first substrate 102a and the second substrate 102b to protect the functional layer 106a made of environment-sensitive material. The glass-to-glass-to-glass integrated seal 302 is usually present along the first portion and the second portion of the two glass substrates 102a and 104a respectively. The glass-to-glass-to-glass integrated seal 302 is positioned between the substrates 102a and 104a at an outer periphery of the two substrates around the functional layer 106a made of environment-sensitive material. A thickness of the glass-to-glass-to-glass integrated seal 302 can be between 5 microns and 1 millimeter and a width can be between 20 microns and 20 millimeters.
[0034] The structure of the glass-to-glass-to-glass integrated seal 302 has been illustrated and described in detail in association with the FIGs. 4a and 4b that illustrate cross-sectional views of the glass-to-glass-to-glass integrated seal 302 in accordance with two exemplary embodiments of the present invention. To describe the glass-to-glass-to-glass integrated seal

302, reference will be made to FIG la, lb, 2 and 3, although it is understood that the glass-to-glass-to-glass integrated seal 302 can be implemented using other suitable devices as well.
[0035] The glass-to-glass-to-glass integrated seal 302 can be in the form of a plurality of substantially continuous glass fibers 402, such that a cross-section of the glass fibers 402 is substantially circular. Also, the glass fibers 402 are arranged closely and are substantially mutually parallel to each other. Further, space between the glass fibers 402 is usually filled with a matrix 404.
[0036] FIGs. 4a and 4b illustrate two possible arrangements of the glass fibers 402 in the matrix 404. For example, in FIG 4a, the glass fibers 402 are arranged to form a honeycomb like structure whereas in FIG 4b the glass fibers 402 are arranged in a rectangular fashion. Even thought the figures illustrate only two specific arrangements of the glass fibers 402, it should be appreciated by the people skilled in the art that other arrangements in which the glass fibers 402 are closely packed and are substantially parallel to each other are also possible, without deviating from the scope of the invention.
[0037] The closely packed and substantially mutually parallel glass fibers 402 are arranged in the form of multiple layers, such that each of the multiple layers has multiple substantially continuous fibers. Further, the arrangement is such that each glass fiber 402 touches at least one substantially continuous fiber 402 of an adjacent layer and is aligned to be substantially parallel to the substantially continuous fiber 402 of the adjacent layer. In an embodiment, a single fiber that can touch both substrates everywhere can perform a similar function.
[0038] The matrix 404 can be in the form of solid material, semi-solid material, and liquid material and are mixed with the glass fibers 402 such that the glass fibers 402 are substantially impregnated in the matrix 404.
[0039[ Examples of material for the matrix 404 include, but are not limited to, compounds comprising a thermoset and/or thermoplastic materials, epoxies, phenolics, phenols, polyesters, polyamides, polyamidimides, polysulphones, polyether sulphones, polycarbonates, polyethylene terepthalates, and polyether ketones (e.g. polyether ketone (PEK), polyether

ether ketone (PEEK), polyether ketone ketone (PEKK) and the Hke), combinations thereof, and precursors thereof.
[0040] The glass fibers 402 may be of any size diameter sufficient to prevent permeation of matter external to the device. For example, the mean diameter of the glass fibers 402 may be from about 1 |a.m, or less, to about 5000 |^m.
[0041] The glass-to-glass-to-glass integrated seal 302 may be formed using a number of techniques including, but not limited to, solution processes, such as solution dip and solution spray, as well as melt and working processes, such as direct melt and film calendaring and processes such as wet filament winding. These processes are designed to bring at least a portion of the glass fibers 402 into contact with the matrix 404 in a flowable state and impregnate the glass fibers 402 with the matrix 404. Further, once the glass fibers 402 have been mixed with the matrix 404, they are consolidated, and cured to form glass-to-glass-to-glass integrated seal 302 that is also bonded to the first glass substrate 102a and the second glass substrate 102b to form a completely enclosed housing for the functional stack 106a made of environmentally sensitive materials. The step of curing can be carried out thermally or by Ultra Violet exposure. In an embodiment, the curing can be performed under external constant pressure so that a closely packed orientation of the glass-fibers can be arranged as much as possible and a very high fill factor of the glass-fibers is reached.
[0042[ In an embodiment, the glass fiber content of the glass-to-glass-to-glass integrated seal 302 may be varied, as dictated by the application, and may range between about 80 to 95 volume %, preferably from 89 to 91 volume %.
[0043] This low matrix content results in a substantial reduction of the possibility of penetration by water and gas. Further, the extremely small matrix-surface available for diffusion between the parallel glass fibers 402 perpendicular to the diffusion direction also reduces the permeation possibility.
[0044] Various embodiments, as described above, provide a device having a glass-to-glass-to-glass sealing structure that has several advantages. For example, the glass-to-glass-to-glass sealing structure used substantially decreases chances of permeation of matter external to the

device like water and oxygen, thereby reducing the adverse effect on the environmentally sensitive materials. Further, the material used in the glass-to-glass-to-glass sealing structure, is substantially cheaper than the glass-pocket based designs used conventionally, thereby resulting in a more efficient and cheaper sealing configurations.
[0045] While the invention has been disclosed in connection with the preferred embodiments shown and described in detail, various modifications and improvements thereon will become readily apparent to those ordinarily skilled in the art. Accordingly, the spirit and scope of the present invention is not to be limited by the foregoing examples, but is to be understood in the broadest sense allowable by law.
[0046] All documents referenced herein are hereby incorporated by reference.

What is claimed is:
1. A device comprising:
a first glass substrate, said first glass substrate having a first interior surface and a substantially parallel first exterior surface, said first interior surface defined by a first portion, wherein said first portion is substantially proximal to a perimeter of said first interior surface;
a second glass substrate, said second glass substrate having a second interior surface and a substantially parallel second exterior surface, said second interior surface defined by a second portion, wherein said second portion is substantially proximal to a perimeter of said second interior surface and corresponds to said first portion;
one or more environment-sensitive materials disposed between said first interior surface and said second interior surface; and
a plurality of substantially continuous glass fibers disposed between said first portion and said second portion, a cross-section of said glass fibers being substantially circular, wherein said glass fibers are arranged closely and substantially mutually parallel, and wherein space between said glass fibers is filled with epoxy resin, whereby creating a glass-to-glass-to-glass integrated seal between said first substrate and said second substrate, and wherein said seal is impermeable to matter external to device thereby protecting said environment-sensitive material.
2. The apparatus according to claim 1, wherein said plurality of substantially continuous glass fibers are bonded with said first glass substrate and said second glass substrate to form said seal by using one of heat and Ultra Violet exposure and pressure.
3. The apparatus according to claim 1, wherein said plurality of substantially continuous glass fibers are disposed using one of filament winding and wet filament winding.

4. The apparatus according to claim 1, wherein said plurality of substantially continuous glass fibers are arranged in the form of multiple layers, wherein each of said multiple layers has multiple substantially continuous fibers.
5. The apparatus according to claim 2, wherein each substantially continuous fiber of a layer touches one substantially continuous fiber of an adjacent layer and is aligned substantially parallel to said substantially continuous fiber of said adjacent layer.
6. The apparatus according to claim 1, wherein each substantially continuous fiber of a layer touches at least two substantially continuous fibers of an adjacent layer.
7. The apparatus according to claim 1, wherein said device is selected from the group comprising a light emitting diode, an organic light emitting diode, a photovoltaic cell, an organic photovoltaic cell, and a liquid crystal device.
8. The apparatus according to claim 1, wherein said device is an organic light emitting
diode, further wherein said one or more environment-sensitive materials is a functional
stack of said organic light emitting diode.