The present disclosure relates to methods of treating a glass surface, and more particularly methods of forming a glass surface comprising a uniformly distributed coating offering high adhesion reliability of a printed pattern.
MicroLED displays have drawn attention due to self-direct emission, high brightness, high contrast, low power consumption, and longer lifetime compared to TFT-LCD and OLED displays. To make large-size microLED displays, substrates with vias are typically pursued for display concepts that need tiling since the drivers and printed circuit board (PCB) are placed on the backside of the display for seamless assembly of each tile, tile assembly, glass part, etc. Connection between microLEDs on a substrate surface (glass, transparent ceramics or substrates materials) and IC drives or other components on the back can still be realized by wrapped-edge (wrap-around) electrodes.
For seamless tiling, each tile should have an edge profile that aligns well with an immediately-adjacent tile. Therefore, accurate tile alignment should be provided during fabrication and wrap-around electrodes over tile edges should exhibit mechanical reliability. In addition, the wrap-around electrodes need to exhibit mechanical reliability.
One approach to enhancing reliability for both the display tile and the wrap-around electrodes is to apply protective edge coatings, durable thin films, or thin laminates. The protective coating may also provide additional optical advantage. For example, applying black or other highly absorbing adhesive coatings, thin films, or hybrid coatings on the electrode-wrapped edges of the display tiles can suppress light reflection. The edge coating may also be a non-absorbing clear or non-clear coating or film.
Accordingly, a display apparatus is disclosed, a glass article comprising a glass substrate including a first major surface, a second major surface opposite the first major surface, and at least one edge surface extending between and connecting the first major surface to the second major surface, the glass substrate further comprising a coating material deposited as a contiguous coating layer on the at least one edge surface and at least a portion of the first major surface or the second major surface along and proximate the at least one edge surface, the coating layer extending an overflow distance on the at least a portion of the first major surface or the second major surface in a range from equal to or greater than 25 micrometers to equal to or less than about 170 micrometers. A thickness of the coating layer can be equal to or less than about 100 micrometers, for example equal to or less than about 50 micrometers, equal to or less than about 10 micrometers, or equal to or less than about 4 micrometers. The coating material can comprise an epoxy. A thickness of the glass substrate is in a range from about 300 micrometers to about 1.3 millimeters.
In some embodiments, a bulk resistivity of the coating material can be equal to or greater than about 1×108 ohm, for example equal to or greater than about 1×1015 ohm.
In some embodiments, a surface roughness Sa of the coating layer can be equal to or less than about 250 nanometers.
In some embodiments, an optical density of the coating layer can be equal to or greater than about 1.8, for example, equal to or greater than about 2, such as in a range from equal to or greater than about 2 to equal to or less than about 2.5.
In some embodiments, the at least one edge surface can comprise a plurality of edge surfaces, the contiguous coating layer coating each edge surface.
The at least one edge surface can comprise an arcuate surface.
The glass article may further comprise an electrical conductor extending across the at least one edge surface of the glass substrate from the first major surface to the second major surface the coating layer disposed over the electrical conductor. In some embodiments, an electronic device can be deposited on the first major surface and in electrical communication with the electrical conductor. The electronic device may, for example, comprise an electroluminescent element, such as a light emitting diode.
In other embodiments, a method of coating a glass substrate is described, comprising positioning a plurality of glass substrates and a plurality of spacers in an alternating relationship to form a substrate stack, each glass substrate comprising a first major surface, a second major surface, a first edge surface extending between and connecting the first major surface and the second major surface, and a second edge surface extending between and connecting the first and second major surfaces, and clamping the substrate stack between a first platen and a second platen in a fixture. The fixture can be mounted beneath a screen, the clamped substrate stack rotatable in the fixture about an axis of rotation orthogonal to the first major surface of each glass substrate, and the clamped stack oriented to a first orientation. A coating material can then be applied to the screen. Once the screen is wetted with the coating material, the method further comprises forcing a squeegee onto the screen and deflecting the screen toward the first edge surfaces, traversing the squeegee across the screen in a first direction orthogonal with the axis of rotation from a start position to a stop position to apply the coating material to the first edge surfaces, and returning the squeegee to the start position. Once the first edge surfaces are coated, the method may further comprise rotating the substrate stack to a second orientation, forcing the squeegee onto the screen and deflecting the screen toward the second edge surfaces, and traversing the squeegee in the first direction across the screen from the start position to the stop position to apply the coating material to the second edge surfaces. In some embodiments, the first orientation can be orthogonal to the second orientation
The coating material can be applied to at least a portion of at least one of the first major surface or the second major surface of each glass substrate simultaneous with applying the coating to the first edge surface. An overflow distance on the at least a portion of the first major surface or the second major surface in a range from equal to or greater than 25 micrometers to equal to or less than about 170 micrometers.
In some embodiments, each glass substrate can comprise at least one electrical conductor extending across the first edge surface from the first major surface to the second major surface, and the coating material is applied over the at least one electrical conductor.
Each of the first platen and the second platen comprises a first major surface, a second major surface, and a first edge surface extending between and connecting the first major surface and the second major surface, the first edge surface of the first platen and the first edge surface of the second platen defining a first plane. The first edge surfaces of the glass substrates can extend outward from the first plane a distance in a range from about 10 micrometers to about 100 micrometers.
In some embodiments, each spacer comprises a first major surface, a second major surface, and a first edge surface extending between and connecting the first major surface and the second major surface of the respective spacer, and a distance between the first edge surface of one of the glass substrates and the first edge surface of a spacer adjacent to the one of the glass substrates can be in a range from about 1 mm to about 3 mm.
A thickness of each spacer can be in a range from about 1 millimeter to about 20 millimeters.
In some embodiments, the coating material applied to the first edge surface of each glass substrate is not cured prior to the applying the coating material to the second edge surface of each substrate.
In some embodiments, each glass substrate in the substrate stack comprises at least three edge surfaces, and the method further comprises coating each edge surface of each glass substrate with the coating material and curing the coating material after the coating material has been applied to each edge surface.
Additional features and advantages of the embodiments disclosed herein will be set forth in the detailed description that follows, and in part will be clear to those skilled in the art from that description or recognized by practicing the embodiments described herein, including the detailed description which follows, the claims, as well as the appended drawings.
It is to be understood that both the foregoing general description and the following detailed description present embodiments intended to provide an overview or framework for understanding the nature and character of the embodiments disclosed herein. The accompanying drawings are included to provide further understanding and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments of the disclosure, and together with the description explain the principles and operations thereof.
Reference will now be made in detail to embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts. However, this disclosure can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.
As used herein, the term “about” means that amounts, sizes, formulations, parameters, and other quantities and characteristics are not, and need not be, exact, but may be approximate and/or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art.
Ranges can be expressed herein as from “about” one value, and/or to “about” another value. When such a range is expressed, another embodiment includes from the one value to the other value. Similarly, when values are expressed as approximations by use of the antecedent “about,” it will be understood that the value forms another embodiment. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.
Directional terms as used herein—for example up, down, right, left, front, back, top, bottom—are made only with reference to the figures as drawn and are not intended to imply absolute orientation.
Unless otherwise expressly stated, it is in no way intended that any method set forth herein be construed as requiring that its steps be performed in a specific order, nor that with any apparatus, specific orientations be required. Accordingly, where a method claim does not actually recite an order to be followed by its steps, or that any apparatus claim does not actually recite an order or orientation to individual components, or it is not otherwise specifically stated in the claims or description that the steps are to be limited to a specific order, or that a specific order or orientation to components of an apparatus is not recited, it is in no way intended that an order or orientation be inferred in any respect. This holds for any possible non-express basis for interpretation, including: matters of logic with respect to arrangement of steps, operational flow, order of components, or orientation of components; plain meaning derived from grammatical organization or punctuation, and; the number or type of embodiments described in the specification.
As used herein, the singular forms “a,” “an” and “the” include plural references unless the context clearly dictates otherwise. Thus, for example, reference to “a” component includes aspects having two or more such components, unless the context clearly indicates otherwise.
The word “exemplary,” “example,” or various forms thereof are used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as “exemplary” or as an “example” should not be construed as preferred or advantageous over other aspects or designs. Furthermore, examples are provided solely for purposes of clarity and understanding and are not meant to limit or restrict the disclosed subject matter or relevant portions of this disclosure in any manner. It can be appreciated that a myriad of additional or alternate examples of varying scope could have been presented but have been omitted for purposes of brevity.
As used herein, the terms “comprising” and “including”, and variations thereof, shall be construed as synonymous and open-ended, unless otherwise indicated. A list of elements following the transitional phrases comprising or including is a non-exclusive list, such that elements in addition to those specifically recited in the list may also be present.
The terms “substantial,” “substantially,” and variations thereof as used herein are intended to represent that a described feature is equal or approximately equal to a value or description. For example, a “substantially planar” surface is intended to denote a surface that is planar or approximately planar. Moreover, “substantially” is intended to denote that two values are equal or approximately equal. In some embodiments, “substantially” may denote values within about 10% of each other, such as within about 5% of each other, or within about 2% of each other.
Display apparatus 10 may further comprise a cover plate 18 positioned between display panel 12 and a viewer 20 of the display apparatus. That is, display cover plate 18 is positioned in front of display panel 12 relative to viewer 20. Cover plate 18 may be a glass plate or a polymer (e.g., plastic) cover plate. In some embodiments, cover plate 18 may be a laminate cover plate comprising multiple layers, for example a combination of glass and polymer layers. In some embodiments, cover plate 18 may include one or more films, for example an anti-reflection film.
Referring now to
Tile substrate 22 comprises first major surface 24 and second major surface 26, which major surfaces may, in various embodiments, be planar or substantially planar, e.g., substantially flat. First major surface 24 and second major surface 26 may, in various embodiments, be parallel or substantially parallel (e.g., within manufacturing tolerances). Tile substrate 22 further comprises an edge surface 30 extending between and connecting first major surface 24 and second major surface 26, edge surface 30 defining an outer perimeter of tile substrate 22. By way of a non-limiting example, tile substrate 22 may comprise a rectangular (e.g., square), or rhomboid plate with four edge surfaces, such as four edge surfaces 30 joined at right angles (orthogonal) to each other as shown in
In certain embodiments, tile substrate 22 can have a thickness Thl between first major surface 24 and second major surface 26 less than or equal to about 3 mm, for example, in a range from about 0.1 mm to about 3 mm, from about 0.1 mm to about 2.5 mm, from about 0.3 mm to about 2 mm, from about 0.3 mm to about 1.5 mm, from about 0.3 mm to about 1 mm, from about 0.3 mm to about 0.7 mm, or in a range from about 0.3 mm to about 0.5 mm, including all ranges and subranges therebetween.
In embodiments, first major surface 24 of tile substrate 22 can comprise pixel elements 16 deposited thereon and arranged in an array, for example a plurality of rows 36 of pixel elements 16 and a plurality of columns 38 of pixel elements 16. For example, the exemplary display tile shown in
As is understood in the art, different types of displays can utilize different types of pixel elements to provide a display image. For example, in an organic light emitting diode (OLED) display, a pixel element can comprise rows and/or columns of “emitters” and thin film transistors (TFTs) connected by row drivers and column drivers that activate the pixel elements, while the pixel element in liquid crystal displays (LCD) may comprise rows and columns of liquid crystal (LC) light valves and transistors connected by row drivers and column drivers that activate the pixel elements. Accordingly, pixel elements are the components required for the functioning of individual pixels in the display and can include light emitting elements (e.g., light emitting diodes) or light valves and TFTs. The descriptions provided herein are simplified such that each pixel element is illustrated comprising one color pixel, whereas in reality each pixel element may be comprised of one or more subpixels (e.g., red, green and blue subpixels). Individual pixel elements can be addressed by a unique row and column combination utilizing known technology.
Each row 36 of pixel elements 16 can be connected by a row electrical trace 40, and each column 38 of pixel elements 16 can be connected by a column electrical trace 42. As used herein, an electrical trace is an electrical conductor configured to direct electrical current to and from electrical components of the display apparatus. Electrical traces can be applied to a major surface of the tile substrate, for example, by depositing an electrical conductor material on a surface of a tile substrate and forming the electrical traces by photolithography wherein selected portions of the electrical conductor material are covered by a masking material and unneeded electrical conductor material removed with an etchant. However, other methods of forming electrical traces as are known in the art may be used. For example, in further embodiments, electrical traces may be applied, such as with an adhesive. In some embodiments, electrical trances may comprise wires.
While the exemplary display tile shown in
As will be appreciated, row drivers 50 and column drivers 52 must be connected to the row electrical traces 40 and the column electrical traces 42 to activate pixel elements 16. Accordingly, a plurality of row edge connectors 54 may be provided, wherein each row edge connector 54 can be wrapped around an edge surface 30 and electrically connect through a row electrical trace 40 a row 36 of pixel elements 16 and a row driver 50. Display tile 14 may further comprise a plurality of column edge connectors 56, wherein each column edge connector 56 can be wrapped around an edge surface 30 and electrically connect through a column electrical trace 42 a column 38 of pixel elements 16 and a column driver 52. As used herein, a row and column edge connectors comprises an electrical conductor that wraps around an edge of the tile substrate. In the embodiment shown, each row driver 50 connects one row 36 of row electrical traces 40 to row pixel elements, and each column driver 52 connects two columns of column electrical traces 42 to column pixel elements. However, the depicted arrangement is for illustration purposes, and the disclosure is not limited to any particular number of row drivers, column drivers or number of row electrical traces or column electrical traces respectively driven by the row drivers and column drivers. For example, the row and column edge connectors can exist on one or more edge surfaces 30 based on the specific display apparatus design and layout.
Display tile 14 can be free of a bezel around the outer perimeter of tile substrate 22. To achieve a seamless display apparatus, a pixel pitch (distance between nearest adjacent pixel elements) across a tile-to-tile seam should be approximately matched to a comparable distance between adjacent pixel elements within a single display tile. For example, the distance between adjacent pixel elements can be equal to or less than about 10 millimeters (mm), equal to or less than about 5 mm, equal to or less than about 3 mm, equal to or less than about 1 mm, equal to or less than about 0.5 mm, or equal to or less than about 0.3 mm from an edge of the display tile substrate. Pixel elements on one display tile can then be registered to adjacent pixel elements on an adjacent display tile with a placement error equal to or less than about 50%, equal to or less than about 30%, equal to or less than about 10%, or equal to or less than about 5% of a pixel pitch (distance between adjacent pixels on a display tile).
Any suitable connector type can be utilized to provide row edge connectors 54 and column edge connectors 56. Also, the row and column edge connectors need not be of the same type or design. In one or more embodiments, a row edge connector 54 and/or a column edge connector 56 can comprise a flex circuit 60 shown in
Turning to
In various embodiments, the coating material can be disposed over row and column edge connectors 54, 56 on edge surfaces 30. More specifically, the coating material can form a contiguous coating layer 70 over the one or more edge surfaces of the display substrate. As used herein, “contiguous” means the coating layer is uninterrupted, with no gaps or discontinuities. In various embodiments, the coating material may also be applied to major surfaces 24 and/or 26 of display tile 14 such that at least a portion of the first major surface 24 and/or the second major surface 26 of tile substrate 22 comprises a coating layer 70 contiguous with the coating layer 70 disposed on an edge surface of the tile substrate. That is, coating layer 70 can be disposed on an edge surface 30 and can extend over the edge surface onto the connected major surface (e.g., first and/or second major surfaces 24 or 26) along a length of the respective edge surface. This extension of coating layer 70 onto one or both major surfaces 24 or 26 of the display tile is termed “overflow.” In various embodiments, coating layer 70 can comprise terminal edges 72 and 74 corresponding to the cessation of overflow on first and second major surfaces 24, 26, respectively. For example, in the absence of overflow, the terminal edges of a well-applied coating material correspond to the edges of the coating layer at the intersection of the edge surface 30 and the first major surface 24, and/or the intersection of the edge surface 30 and the second major surface 26. However, in the presence of overflow, a terminal edge of the coating layer corresponds to the line demarking (e.g., separating) that portion of the display tile with a coating layer and that portion of the display tile that is uncoated. That is, terminal edges 72, 74 are the edges of the coating layer where the flow of coating material stopped on the respective display tile major surface. The extent of the overflow, D1, defines a distance of the overflow measured from the intersection of an edge surface 30 and the major surface to the corresponding terminal edge along a line orthogonal to the intersection. While the description above relates to a single edge surface 30, a coating layer can be applied to each edge surface 30 of a display tile in similar manner. The coating layer overflow distance D1 can be in a range from greater than zero μm to equal to or less than about 170 μm, for example in a range from equal to or greater than 25 μm to equal to or less than about 150 μm. However, in further embodiments, D1 in excess of 170 μm has been achieved. In various embodiments, an optical density of the coating layer can be equal to or greater than about 1.8 as measured with a Gretag Macbeth D200-II optical density meter. For example, an optical density of the coating layer can be equal to or greater than about 2, such as in a range from about 2 to equal to or less than about 2.5.
A thickness Th3 (see
In some embodiments, edge surface 30 can be substantially planar and orthogonal to first and second major surfaces 24, 26 as shown in
Referring now to
As best shown in
In the event corresponding edge surfaces are curved, each corresponding edge surface 30 includes an apex extending lengthwise along a length of the edge surface, wherein the display tiles are arranged in the stack such that the apexes of the plurality of corresponding parallel edge surfaces define a plane. This can be better understood with the aid of
For clarity, the apex of a planar edge surface, as depicted in
As described above, spacers 120 can be positioned between display tiles 14 within a stack 118. For example, spacers 120 can be sized and configured such that when interposed in stack 118, edge surfaces 128 of spacers 120 are recessed a distance D3 relative to corresponding edge surfaces 30 of adjacent display tiles (see
Rotary fixture 116 can be configured to hold stack 118 in a predetermined orientation relative to a reference plane, for example a plane of base 102. Screen assembly 104 can then be adjusted such that a plane of screen 108 is parallel with an upward facing face of the stack. Plane 130 is defined between attachment points of screen 108 to frame 106. For example, rotary fixture 116 can be configured to hold stack 118 such that a face of the stack (corresponding edge surfaces 30) is held substantially parallel to base 102, and more particularly, so that corresponding edge surfaces of the display substrates comprising stack 118 facing screen 108 are substantially parallel with base 102. As best seen in
In some embodiments, as further shown in
Rotary fixture 116 may further comprise a detent mechanism 160, for example a spring-loaded detent arranged in a bore and configured to hold first clamping pad 142a in a predetermined orientation while still allowing first clamping pad 142a to rotate about axis of rotation 152 if sufficient rotational force is applied to first clamping pad 142a. As used herein, a detent mechanism is a mechanism (such as comprising a detent—a catch, pin, dog, or spring-operated ball, for example) for positioning and holding one mechanical part in relation to another in a manner such that the detent can be released by force applied to one of the parts. For example, support member 140 may comprise a detent 162 maintained within bore 164 under spring force such that detent 162 is biased outward from bore 164 toward first clamping pad 142a. Bore 164 may include a collar or other device at the outward edge of the bore to maintain detent 162 within bore 164. First clamping pad 142a may include a plurality of recesses 166 positioned to engage with detent 162 as first clamping pad 142a rotates about axis of rotation 152, recesses 166 positioned such that when engaged with detent 162, a side of stack 118 is oriented substantially parallel with plane 130 of screen 108. For example, in apparatus designed to accommodate display substrates with four sides, first clamping pad 142a can include four recesses arranged at 90-degree intervals (e.g., 0 degrees, 90 degrees, 180 degrees, 270 degrees) so that as stack 118 is rotated about axis of rotation 152, detent 162 engages with first clamping pad 142a to orient stack 118 in predetermined intervals, e.g., 90-degree intervals such that a side of the stack is oriented parallel with plane 130. In some embodiments, detent mechanism 160 may be unnecessary. For example, if one or both clamping pads is coupled to a motor, e.g., stepper motor, a motor controller in communication with the motor may be configured to stop rotation of the stack at predetermined angular orientations, maintaining the selected predetermined orientation until further rotation is initiated by the motor controller. In still other embodiments, the motor may be used in conjunction with a detent mechanism.
Stack 118 can be assembled using a suitable stacking jig. For example,
Referring now to
With first platen 122a in place, a first display tile 14 can be positioned on first platen 122a such that edge surfaces 30 of the first tile substrate extend outward from corresponding edge surfaces of first platen 122a. That is, so that edge surfaces of the first platen are recessed relative to corresponding edge surfaces 30 of the first tile substrate. A suitable recess depth D4 (See
Although the preceding process for adding display substrates and spacers is described starting with a tile substrate adjacent the platens, in some embodiments, the process can start and end with a spacer adjacent the platens. Rotary fixture 116 can be removed from stacking jig 200 once stack 118 is clamped in rotary fixture 116.
Referring now to
Screen 108 can then be wetted with coating material by dispensing coating material from coating material delivery system 110. In some embodiments, it may be necessary to screen print to a surrogate material before printing to the stack, for example paper, to ensure screen 108 is fully wetted. Print quality on the paper can be evaluated for this determination.
Once a determination has been made that the screen is fully wetted and printing is satisfactory, a first side of stack 118 can be printed by operating squeegee assembly 112 to move the squeegee across the screen in a direction parallel with a length direction of the display substrate edge surfaces while applying a downward force on the screen with the squeegee. The squeegee blade can be oriented at an angle relative to plane 130, for example a 45-degree angle, although other angles may be used as necessary to achieve a consistent coating layer.
When the edge surfaces of one side of the stack have been printed, the stack can be rotated by rotating platens 122a, 122b (via threaded rod 154) to orient a second face of the stack to be substantially parallel with the screen plane and the squeegee once again traversed across the screen to apply coating material to the second set of display substrate edge surfaces. This process is repeated until all edge surfaces needing a coating layer are coated with coating material. There is no need to cure the coating material after each application of the coating material to the edge surfaces. Cure of the coating material can be performed after all edge surfaces have been coated in a manner consistent with the coating material manufacturer's directions. For example, if the coating material is a thermally-cured coating material, thermal curing (e.g., time and temperature) can be carried out in accordance with the coating material manufacturer's instructions. If the coating material is a UV-curable coating material, UV curing can be accomplished similarly (e.g., according to the coating manufacturer's recommended practices.
If, after screen printing the display substrates of a first stack additional stacks are desired to be printed, the procedure described above can be repeated. Print to paper may be performed after printing each stack to ensure the ink is uniformly applied to a subsequent stack (e.g., the screen is fully wetted and clogging of the screen has not occurred).
Experiments were conducted to assess the impact of spacer thickness on coating layer overflow width D1. Both glass and polyethylene terephthalate glycol spacers were sandwiched between glass tile substrates in a stack held by a rotary fixture 116 as described herein, the spacers having thicknesses varying between 0.19 mm, 0.3 mm and 0.5 mm. In one such experiment, a mix of 0.3 mm and 0.5 mm thick spacers were used. An epoxy ink, Wayglo FC-725 from Chime Mien Ink Chemical Company, Ltd., with 15% by weight FC-182 thinner and 10% by weight FC-941 Catalyst (hereinafter “Wayglo”), was applied to the edge surfaces of the tile substrates in accordance with methods described herein. The resultant coating layer was cured at 150° C. for 30 minutes, and the coating layer overflow measured. Thickness of the coating layer was measured with an optical scattering instrument and overflow was measured using an optical microscope. The results are plotted in
An experiment was conducted to determine the impact of chamfer on overflow width D1. A plurality of 0.5 mm spacers were sandwiched in an alternating arrangement between 100 tile substrates with unchamfered edge surfaces in a stack held by a rotary fixture 116 as described herein. Wayglo was applied to the edge surfaces of the tile substrates in accordance with methods described herein. The resultant coating layer was cured at 150° C. for 30 minutes, and the coating layer overflow measured using an optical microscope. The results are plotted in
An experiment was conducted to assess the impact of tile substrate-spacer alignment (e.g., offset) on coating layer overflow width D1. In a first experiment, seven tile substrates were stacked in an alternating arrangement with six 0.5 mm-thick spacers, the resultant stack held by a rotary fixture 116 as described herein. The tile substrates were arranged such that several tile substrates were shorter than adjacent tile substrates (e.g., recessed below the adjacent tile substrates) and several tile substrates were raised with shims 310 to be higher than the adjacent tile substrates. The arrangement of tile substrates is shown in
Another experiment was conducted to assess the impact of tile substrate-spacer alignment (e.g., offset) on coating layer overflow width D1. In a first experiment, eight tile substrates were stacked in an alternating arrangement with seven 0.5 mm-thick spacers, the resultant stack held by a rotary fixture 116 as described herein. The tile substrates were arranged such that several tile substrates were shorter than adjacent tile substrates (e.g., recessed below the adjacent tile substrates) and several tile substrates were raised with shims 310 to be higher than the adjacent tile substrates. The arrangement of tile substrates is shown in
Additional experiments were conducted to assess the impact of screen state on coating layer overflow width D1. In a first experiment, a plurality of tile substrates were stacked in an alternating arrangement with 0.5 mm-thick spacers, the resultant stack held by a rotary fixture 116 as described herein. Wayglo was applied to the edge surfaces of the tile substrates in accordance with methods described herein using a fresh screen, wherein the screen did not contain coating material prior to printing to the edge surfaces. The resultant coating layer was cured at 150° C. for 30 minutes, and the coating layer average overflow measured as in previous experiments. In another experiment, another plurality of tile substrates (up to 100 tile substrates) was stacked in an alternating arrangement with 0.5 mm-thick spacers, the resultant stack held by a rotary fixture 116 as described herein. Wayglo was applied to the edge surfaces of the tile substrates in accordance with methods described herein using a screen fully wetted with the coating material. That is, the screen was used to print to paper seven times prior to printing to the tile substrate edge surfaces to ensure a fully wetted screen. The resultant coating layers were cured at 150° C. for 30 minutes, and the coating layer average overflow measured. In still another experiment, another plurality of tile substrates was stacked in an alternating arrangement with 0.5 mm-thick spacers, the resultant stack held by a rotary fixture 116 as described herein. Wayglo was applied to the edge surfaces of the tile substrates in accordance with methods described herein using a screen comprising ink residue from a previous printing operation. The resultant coating layer was cured at 150° C. for 30 minutes, and the coating layer average overflow measured as previously described. The data from these experiments is presented in
It will be apparent to those skilled in the art that various modifications and variations can be made to embodiments of the present disclosure without departing from the spirit and scope of the disclosure. For example, the substrates coating in accordance with embodiments disclosed herein may be used for other purposes and is not confined to display apparatus. Thus, it is intended that the present disclosure cover such modifications and variations provided they come within the scope of the appended claims and their equivalents.
This is a national stage application under 35 U.S.C. § 371 of International Application No. PCT/US2021/034702 filed on May 28, 2021, which claims the benefit of priority under 35 U.S.C. § 119 of U.S. Provisional Application Ser. No. 63/034,730 filed on Jun. 4, 2020, the content of which is relied upon and incorporated herein by reference in their entireties.
Filing Document | Filing Date | Country | Kind |
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PCT/US2021/034702 | 5/28/2021 | WO |
Number | Date | Country | |
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63034730 | Jun 2020 | US |