Patent Application
20230032165
The present disclosure relates generally to coating of electrical conductors. More particularly, the present disclosure relates to coating of edge conductors which electrically couple conductors on opposite surfaces of a substrate, such as a glass substrate of a display tile.
Electronic displays may be used in numerous types of devices such as smart phones, tablet computers, automotive electronics, augmented reality devices, and the like. Tiled displays, in which pixels on adjacent tiles continue at the same pitch as pixels within a tile, may be used to achieve a “zero bezel” or “seamless tiled” display. Tiled displays may include control electronics on or adjacent to one surface of a glass substrate and emitters on an opposite surface of the glass substrate.
One approach to transfer electrical signals between one surface of a glass substrate of a display tile and an opposite surface of the glass substrate may include edge conductors that extend around an edge of a glass substrate from one surface of the glass substrate to an opposite surface of the glass substrate. Such edge conductors, however, may be become damaged due to exposure and/or may impact optical characteristics of the display tile.
Accordingly, coating, at least partially or fully, of edge conductors to protect and/or conceal the edge conductors is disclosed herein.
Some embodiments of the present disclosure relate to an edge conductor. The edge conductor includes a first portion electrically connected to a first conductor on a first surface of a substrate, a second portion electrically connected to a second conductor on a second surface of the substrate, a third portion extending between the first portion and the second portion and extending along an edge of the substrate, and a coating covering at least a portion of the third portion of the edge conductor. The second surface of the substrate is opposite the first surface of the substrate, and the edge of the substrate extends between the first surface of the substrate and the second surface of the substrate.
Other embodiments of the present disclosure relate to a display tile. The display tile includes a substrate having a first surface, a second surface opposite the first surface, and an edge surface extending between the first surface and the second surface. The display tile includes a first conductor on the first surface of the substrate, a second conductor on the second surface of the substrate, and a third conductor extending along each of the first surface, the second surface, and the edge surface. The display tile includes a coating covering at least a portion of the third conductor along the edge surface. The third conductor is electrically coupled with both the first conductor and the second conductor.
Other embodiments of the present disclosure relate to a method of making a display tile. The method includes forming an edge conductor to extend along a first surface of a substrate, a second surface of the substrate opposite the first surface of the substrate, and an edge surface of the substrate, the edge surface extending between the first surface of the substrate and the second surface of the substrate. The method further includes coating at least a portion of the edge conductor along the edge surface of the substrate.
The coated edge conductors and methods disclosed herein enable the transfer of electrical signals from one surface of a glass substrate to an opposite surface of the glass substrate while protecting and/or concealing the edge conductors.
Additional features and advantages will be set forth in the detailed description which follows, and in part will be readily apparent 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 describe various embodiments and are intended to provide an overview or framework for understanding the nature and character of the claimed subject matter. The accompanying drawings are included to provide a further understanding of the various embodiments, and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments described herein, and together with the description serve to explain the principles and operations of the claimed subject matter.
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 may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.
Ranges can be expressed herein as from “about” one particular value, and/or to “about” another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular 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, vertical, horizontal) 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.
Referring to
In the depicted example, substrate 110 has a first surface 112 (
Substrate 110 may be formed of glass, glass ceramic, ceramic, or polymer material, or a composite material including different combinations of such materials in a layered or mixture format. In examples, substrate 110 may have a thickness between 0.005 mm and 2 mm, including, more specifically, a thickness between 0.01 mm and 1 mm, between 0.01 mm and 0.7 mm, between 0.05 mm and 0.6 mm, between 0.1 mm and 0.5 mm, or between 0.2 mm and 0.4 mm. In examples, substrate 110 may be rectangular in shape, as illustrated in
Light sources 180 may be arranged, for example, in an array including any number of rows and columns, or other patterns. Each light source 180 is electrically coupled to drive circuitry, such as drive circuitry or control electronics 190, for driving or controlling operation of each light source 180. Control electronics 190 may include, for example, drive ICs, thin film transistors, microDriver ICs, conductors, capacitors, other electrical elements, and/or electrical interconnects or connections. Although illustrated as being provided on second surface 114, in other examples, control electronics 190 (or components thereof) may be provided on first surface 112 (with light sources 180). Each light source 180 may include, for example, a light emitting diode (LED), a microLED, a miniLED, an organic light emitting diode (OLED), or other suitable light source or light modulator, such as a mirror or light valve. In one example, instead of light sources 180 on first surface 102, first surface 102 may be in contact with a liquid crystal cell.
In examples, first surface 212 and second surface 214 are substantially parallel with each other, and edge surface 218 is substantially orthogonal to first surface 212 and second surface 214. In examples, first surface 212 represents a front or first side 202 of display tile 200 and second surface 214 represents a back or second side 204 of display tile 200.
In the depicted example, substrate 210 has a substantially rectangular shape and includes additional edge (or side) surfaces extending between first surface 212 and second surface 214. In other examples, substrate 210 may have other suitable shapes, such as, for example, circular, triangular, or other polygonal shapes, with corresponding or associated surfaces.
In the depicted example, display tile 200 includes first conductors 220 on first surface 212 of substrate 210 and second conductors 222 on second surface 214 of substrate 210. In examples, first conductors 220 are electrically connected to light sources (not shown) provided on first surface 212 of substrate 210, such as light sources 180 (
In one example, an interconnect material 226 is provided adjacent an end of first conductors 220 and second conductors 222 adjacent to edge surface 218. In examples, interconnect material 226 is a conductive material and facilitates electrical connection of edge conductors 230 with first conductors 220 and second conductors 222, as described below. In examples, interconnect material 226 may include a conductive metal, such as, for example, copper, a conductive paste, such as, for example, an anisotropic conductive paste (ACP), a conductive film, such as, for example, an anisotropic conductive film (ACF), or a conductive adhesive, such as, for example, an anisotropic conductive adhesive (ACA). In other examples, in the absence of interconnect material 226, edge conductors 230 may be in direct connection with first conductors 220 and second conductors 222.
Edge conductors 230 represent third conductors 224 of display tile 200, and provide electrical connection between first conductors 220 and second conductors 222, as described below. More specifically, in examples, edge conductors 230 are formed or bent to extend around edge surface 218 of substrate 210 and provide electrical connection between respective and corresponding first conductors 220 on first surface 212 of substrate 210 and second conductors 222 on second surface 214 of substrate 210. In one example, edge conductors 230 are formed of a metal foil, such as a copper foil. In other examples, edge conductors 230 may be formed of a deposited thin conductor film (e.g., Cu, Ag, Au, Mo, ITO, Ni), a multi-layer stack of deposited thin conductor films, or a printed solution-based conductor (e.g., Ag-ink, Cu-ink, carbon nanotube).
As depicted in the example of
In one example, with edge conductor 230 formed or bent to extend along first surface 212 and second surface 214, first portion 230a and second portion 230b are substantially parallel with each other. As such, first bend 230d and second bend 230e are each a substantially orthogonal bend (i.e., first bend 230d and second bend 230e are each approximately 90 degrees). In one example, first portion 230a and second portion 230b are substantially the same length such that edge conductor 230 extends substantially the same distance along first surface 212 and second surface 214 of substrate 210. In other examples, first bend 230d and/or second bend 230e may be other than 90 degrees, and, in examples, may be curved (with rounded or smooth profiles), beveled or chamfered. Also, in other examples, first portion 230a, second portion 230b, and/or third portion 230c may be of non-equal lengths, widths, thicknesses or material compositions.
In one example, edge conductors 230 may be pressure bonded to substrate 210. More specifically, first portion 230a of a respective edge conductor 230 may be pressure bonded to a respective first conductor 220 on first surface 212 of substrate 210, and second portion 230b of a respective edge conductor 230 may be pressure bonded to a respective second conductor 222 on second surface 214 of substrate 210. Other manners of securing edge conductors 230 to substrate 210, including, more specifically, first conductor 220 and second conductor 222, may also be implemented.
More specifically, as depicted in the example of
As illustrated in the example of
Mechanical advantage(s) of coating 240 include helping to protect edge conductors 230 (as well as edge surface 218 of substrate 210) from damage. This may include protection of edge conductors 230 (as well as edge surface 218) from contact, scratches, indents, mechanical shock, chipping, and/or peeling. In addition, coating 240 may serve as a barrier for environmental contaminants such as corrosion, dust, and/or moisture (which could degrade performance of edge conductors 230). Coating 240 may also enhance the overall mechanical strength of display tile 200. Accordingly, coating 240 helps to improve reliability of display tile 200 by protecting edge conductors 230 (as well as edge surface 218).
Optical advantage(s) of coating 240 include helping to suppress or prevent optical reflection or scattering from edge conductors 230 (as well as edge surface 218 of substrate 210). By minimizing or eliminating unwanted reflection or light scattering from edge conductors 230 (as well as edge surface 218 of substrate 210), coating 240 helps to prevent optical defects and/or avoid generation of interfering images. To provide the noted optical advantage(s), coating 240 may include an optically absorbing coating and/or film. As an optically absorbing coating and/or film, coating 240 absorbs or “traps” light that may otherwise be reflected or scattered from edge conductors 230 (and/or edge surface 218 of substrate 210). As such, coating 240 may cause incident light to either be absorbed or scattered (diffused) away from the viewer. In examples, coating 240 includes an optically absorbing ink. In examples, the optically absorbing ink may have an Optical Density (OD) of >0.5, >1, >1.5, >2, >3, >4, >4.5, >5, or >10 in the visible spectrum of 400-800 nm wavelength range.
In examples, coating 240 may be a clear coating or film, or a non-clear coating or film. In examples, coating 240 may be solvent containing or solvent-free, and may be solvent resistant and chemically/mechanically durable. Coating 240 may contain organics, inorganics, or hybrid materials, including polymers and resins such as acrylates, urethanes, epoxies, silicones and the like, with various possible combinations of binders and solvents. Coating 240 may contain particles of various sizes, i.e., nanoparticles or micro-sized particles, plasticizers and pigments of various colors. Coating 240 may contain additives to enhance adhesion, reduce vaporization of solvents, and/or adjust viscosity. In examples, coating 240 may contain coloring pigments.
In examples, coating 240 is (generally and preferably) non-conductive (i.e., has a high resistance and is not able to conduct electricity) to prevent electrical shorting between adjacent edge conductors 230. In one implementation, coating 240 is an optically absorbing non-conductive black ink. In examples, a thickness of coating 240 may range, for example, from 50 nm to 100 um. In examples, a thickness of coating 240 may range, for example, from 2 um to 50 um. In examples, as coating may be exposed to high temperatures (e.g., 50 degrees C., <100 degrees C., <150 degrees C., <200 degrees C., <250 degrees C., <300 degrees C., <350 degrees C.), coating 240 may be thermally stable.
In examples, coating 240 may include a single layer or multiple layers. In one implementation, coating 240 may be a multi-layer stack, with one layer (or component) of coating 240 being non-conductive and another layer (or component) of coating 240 being optically absorbing. For example, a first, optically transparent, comparably thin (e.g., <1 um thick), non-conductive layer may be applied over (i.e., in contact with) edge conductors 230, and a second, comparably thicker (e.g., >1 um thickness), optically absorbing, possibly electrically conductive layer, may be applied over (i.e., in contact with) the first layer. In examples, thickness, electrical resistivity, optical absorption, hardness, and Young's modulus of the multiple layers may vary.
Coating 240 may be applied, for example, by dipping, rolling, spraying, printing, jetting, moving fibers, brushing, powder-coating, sintering, or other techniques. In addition, coating may be air dried, oven dried, UV cured, IR cured, or dried and cured by a combination thereof. Drying or curing may be incorporated in-line as part of the coating process or may be performed off-line separately from the coating process. In examples, coating 240 may be applied using plasma deposition, chemical vapor deposition (CVD), physical vapor deposition (PVD), or other deposition techniques.
In examples, coating 240 conforms to an edge profile of substrate 210 and a profile or shape of edge conductors 230. Although illustrated as having an orthogonal edge profile, substrate 210 may have another edge profile, such as a beveled or chamfered profile or a non-straight profile, such as curved, rounded, wavy or oscillating. In addition, the edge of substrate 210 may be straight along its length or have a sinusoidal or other non-linear shape.
In one example, as depicted in the example of
In examples, only one edge or multiple edges (e.g., two edges, three edges, all edges) of substrate 210 may include edge conductors 230. As such, coating 240 be applied to any edges including edge conductors 230. Coated edges may be dried or cured one edge at a time, after coating a specific edge, or after coating all desired edges.
In one example, coating 240 includes an ink, and is applied by printing, including, more specifically, screen-printing. With such a printing method, single or multiple layers of coating 240 may be applied using single or multiple composition of inks. As such, hybrid coating or film structures of various thicknesses may be created. The ink of coating 240 may be clear or colored, may be optically absorbing, may consist of multiple layers, may thermal or UV curable, and/or may include a composition containing organics, inorganics or hybrid materials. In addition, the ink of coating 240 may be tuned to achieve certain print thickness, optical density (OD), resistivity, and/or other print features.
In one example, coating 240 is applied to a stacked series of display tiles 200 using a vertical-form screen-printing approach. More specifically, multiple display tiles, such as display tiles 200 with substrates 210 and edge conductors 230, are arranged horizontally and aligned vertically such that edge surfaces 218 of adjacent substrates 210, with edge conductors 230, are exposed. As such, coating 240 may be applied to edge conductors 230 and/or edge surfaces 218 of substrates 210.
The disclosed printing method may be used to apply coating 240 continuously along edge surface 218, for example, from one end to an opposite end, or may be used to apply coating 240 in a pattern, including, for example, only over edge conductors 230. The disclosed printing method helps to enable uniform printing along edge surface 218, and may be used with rigid, semi-rigid, semi-flexible and flexible substrates. The disclosed printing method may also be used for variety of substrate compositions and dimensions. With the vertical-form screen-printing approach disclosed herein, coating 240 may be applied to a single display tile or multiple display tiles at one time.
In one implementation, as schematically illustrated in
In examples, spacer elements 254 are spaced along substrate 252 corresponding to a spacing of edge conductors 230 along edge surface 218. In addition, in examples, spacer elements 254 have a thickness corresponding to (or greater than) a thickness of edge conductors 230. As such, in examples, spacers 250, including, more specifically, spacer elements 254, account for gaps between adjacent edge conductors 230 along first surface 212 (or second surface 214) of substrate 210.
In one implementation, as schematically illustrated in
In one example, as schematically illustrated in
In examples, spacers 250 may include rigid, semi-rigid, semi-flexible, flexible, compressible, and/or incompressible films, layers, and/or components, including, for example, plates, disks, gaskets, posts, tape, etc. In examples, spacers 250 may include adhesive, flowable, curable, removable, dissolvable, soluble, and/or temporary films, layers, and/or components, including, for example, plates, disks, gaskets, posts, tape, etc. In examples, spacers 250 may be single-use, multi-use, and/or reusable.
In examples, a clamp, fixture, tape or other retention or supporting element may be used to temporarily hold the stacked substrates 210 during the printing process. In one example, to help control or reduce ink leakage between adjacent tiles 200, a vacuum-based system may be used to assist with and/or control ink flow.
In examples, as described below, a fixture (or fixtures) may be used to enable the vertical-form printing. More specifically, a fixture (or fixtures) may be used to hold one or multiple display tiles 200 to enable printing on edge surface 218 and over edge conductors 230. In examples, a fixture (or fixtures) may be used to hold and/or align multiple display tiles 200 in a parallel manner to enable printing on multiple display tile edges at the same time.
In the illustrated example, block 262 of fixture 260 includes an opening 268 with opposite grooved edges 269. As such, in one example, each slot 264 is formed by a pair of opposite grooved edges 269. In examples, a depth of slots 264 and/or a height of fixture 260 is such that edge conductors 230, along respective edge surfaces 218, are coplanar with surface 266 when display tiles 200 are positioned in slots 264 of fixture 260. As such, fixture 260 enables printing on parallelly aligned display tile edges. In examples, a print direction is parallel with a length of slots 264.
In examples, fixture 260 may be used to support and/or hold display tiles 200 (with or without spacers such as, for example, spacers 250) during processing, handling, and/or transporting of display tiles 200, including, for example, printing, coating, drying, curing, post-processing, and/or shipping. As such, in examples, fixture 260 helps to prevent display tiles from rubbing together, which could potentially damage the tiles.
As illustrated in the example of
In examples, dimensions of fixture 260, including slots 264, may be adjusted to accommodate different sizes and shapes of display tiles 200. In addition, dimensions of stencil 270, including slots 274, may be adjusted to accommodate a variety of sizes and shapes of display tiles 200.
In one example, as illustrated in
Although specific examples have been illustrated and described herein, a variety of alternate and/or equivalent implementations may be substituted for the specific examples shown and described without departing from the scope of the present disclosure. This application is intended to cover any adaptations or variations of the specific examples discussed herein.
This application claims the benefit of priority under 35 U.S.C. § 119 of U.S. Provisional Application Ser. No. 62/966,286 filed on Jan. 27, 2020, the content of which is incorporated herein by reference in its entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2021/013148 | 1/13/2021 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 62966286 | Jan 2020 | US |
