Improved adhesive layer for flexible cover lenses

Abstract

An exemplary flexible cover lens and a method for its manufacture are described. The method may include exposing a surface of a substrate layer to a surface treatment plasma to form a treated surface of the substrate layer. A silicon-containing adhesive layer may be deposited on the treated surface of the substrate layer. A silane-containing adhesion promoter may be incorporated on the silicon-containing adhesive layer. The method may further include forming a hard coat layer on the silicon-containing adhesive layer, and forming the silane-containing adhesion promoter to be bonded to both the hard coat layer and the silicon-containing adhesive layer. The exemplary flexible cover lens manufactured by the method is not susceptible to folding fatigue along the bending or folding axis of the cover lens.

Description

[Technical Field]

[0001] This technology relates to a flexible display cover lens having an improved adhesive layer. More specifically, this technology relates to a flexible silicon-containing adhesive layer for bonding a substrate to the hard coat layer of a cover lens. [Background technology]

[0002] Displays for electronic devices are made possible by a process that generates intricately patterned material layers on a substrate surface. Generating patterned material on a substrate requires controlled methods for depositing and removing the material. However, new device designs present challenges in generating high-quality material layers that meet the device requirements.

[0003] Therefore, there is a need for improved systems and methods that can be used to produce high-quality devices and structures for electronic displays. This technology addresses these and other needs. [Overview of the Initiative]

[0004] Embodiments of this technology include a flexible cover lens processing method. This method may include exposing the surface of a substrate layer to a surface treatment plasma to form a treated surface of the substrate layer. A silicon-containing adhesive layer may be deposited on the treated surface of the substrate layer. A silane-containing adhesion promoter may be incorporated on the silicon-containing adhesive layer. This method may further include forming a hard coat layer on the silicon-containing adhesive layer, wherein the silane-containing adhesion promoter contributes to the bonding between the hard coat layer and the silicon-containing adhesive layer.

[0005] In additional embodiments, the surface treatment plasma may contain oxygen and argon. In additional embodiments, the treated surface of the substrate layer is not exposed to air before the silicon-containing adhesive layer is deposited on the treated surface of the substrate layer. In yet additional embodiments, the adhesive layer is deposited on the treated surface of the substrate layer by plasma chemical vapor deposition. In yet additional embodiments, the silane-containing adhesion promoter includes a liquid spray-coated or dipping-coated onto the silicon-containing adhesive layer. In additional embodiments, the silane-containing adhesion promoter further includes a methacrylate group. In yet additional embodiments, forming a hard coat layer on the silicon-containing adhesive layer includes coating the silicon-containing adhesive layer with a liquid hard coat polymer, the silicon-containing adhesive layer incorporating the silane-containing adhesion promoter. The liquid hard coat polymer coated on the silicon-containing adhesive layer is then cured to form a hard coat layer on the silicon-containing adhesive layer. In yet additional embodiments, curing the liquid hard coat polymer coated on the silicon-containing adhesive layer may include exposing the liquid hard coat polymer to ultraviolet light.

[0006] Embodiments of this technology further include a flexible cover lens comprising a substrate layer and a silicon-containing adhesive layer. The adhesive layer is located on the substrate layer and further comprises a silicon-containing adhesion promoter. The flexible cover lens further comprises a hard coat layer located on the silicon-containing adhesive layer. The hard coat layer and the substrate layer are located on opposite sides of the silicon-containing adhesive layer, and the adhesion promoter contributes to the bonding between the hard coat layer and the silicon-containing adhesive layer.

[0007] In additional embodiments, the substrate layer is a glass layer characterized by a thickness of less than 50 μm or about 50 μm. In additional embodiments, the silicon-containing adhesive layer comprises a silicon oxide layer characterized by a thickness of less than 1 μm or about 1 μm. In further additional embodiments, the silicon-containing adhesion promoter comprises an acrylicoxyalkylsilane compound. In further additional embodiments, the hard coat layer comprises a urethane acrylate polymer characterized by a thickness of less than 50 μm or about 50 μm. In additional embodiments, the flexible cover lens does not contain an optically clear adhesive.

[0008] Embodiments of this technology further include a flexible display device structure comprising a light source and a flexible cover lens. The flexible cover lens is disposed on the flexible display structure and may include a glass layer characterized by a thickness of less than 50 μm or about 50 μm. The flexible cover lens further includes a silicon-containing adhesive layer disposed on the surface of the glass layer and a hard coat layer disposed on the silicon-containing adhesive layer. The hard coat layer and the glass layer are located on opposite sides of the silicon-containing adhesive layer, and a silane-containing adhesion promoter contributes to the bonding between the hard coat layer and the silicon-containing adhesive layer.

[0009] In additional embodiments, the silicon-containing adhesive layer comprises a silicon oxide layer. In additional embodiments, the adhesion promoter comprises an acrylicoxyalkylsilane compound. In yet additional embodiments, the flexible cover lens features a thickness of less than 100 μm or about 100 μm. In additional embodiments, the flexible display structure further comprises a touch panel. In yet additional embodiments, the light source comprises a light-emitting diode, an organic light-emitting diode, a liquid crystal display, or a quantum dot display.

[0010] This technology offers several advantages over conventional methods of bonding material layers of flexible cover lenses using optically transparent adhesives. For example, embodiments of this technology bond layers of a flexible cover lens using a silicon-containing adhesive layer and a silane-containing adhesion promoter. This silane-containing adhesion promoter maintains the bond between the layers through more bending cycles of the cover lens and other components of a foldable display. In embodiments, the silane-containing adhesion promoter includes at least one silane group that forms a strong bond with the silicon-containing adhesive layer and one or more additional bonding groups, such as alkyl groups, that form a bond with the organic polymer of the hard coat layer.

[0011] Further understanding of the nature and merits of the disclosed technology may be achieved by referring to the remainder of this specification and the drawings. [Brief explanation of the drawing]

[0012] [Figure 1] This figure shows an exemplary operation of a method for forming a flexible cover lens according to an embodiment of this technology. [Figure 2A] This is a simplified cross-sectional view of a flexible cover lens formed according to an embodiment of this technology. [Figure 2B] This is a simplified cross-sectional view of a flexible cover lens formed according to an embodiment of this technology. [Figure 2C] This is a simplified cross-sectional view of a flexible cover lens formed according to an embodiment of this technology. [Figure 2D] This is a simplified cross-sectional view of a flexible cover lens formed according to an embodiment of this technology. [Figure 3] This is a simplified cross-sectional view of a flexible cover lens according to an additional embodiment of this technology. [Figure 4] This is a simplified cross-sectional view of a flexible display device including a flexible cover lens according to an embodiment of the present technology. [Modes for carrying out the invention]

[0013] Some of these figures are included as schematic diagrams. It should be understood that these figures are for illustrative purposes and that, unless specifically stated otherwise, the magnification is not constant. Furthermore, as schematic diagrams, these figures are provided to aid understanding and may contain exaggerated content for illustrative purposes, rather than including all aspects or information compared to a realistic representation.

[0014] In the accompanying figures, similar components and / or features may have the same reference numerals. Furthermore, by following the reference numerals with letters to distinguish similar components, different components of the same type may also be distinguished. If only the first reference numeral is used in this specification, the description applies to any one of the similar components having the same first reference numeral, regardless of the letter.

[0015] An electronic device display typically includes several layers of intricately patterned delicate materials that cooperate to function in displaying a high-resolution image. These layers can include, among other types of layers, a colorization layer for controlling the color of the displayed image, a polarizing layer for controlling the polarization of light in the displayed image, and an attenuation layer for controlling the intensity of light in the displayed image. A cover lens is typically placed over these layers to protect the device display, among other environmental and usage hazards, from moisture, pressure, particle contamination, and scratches. The cover lens typically includes a non-flexible hard surface, often made of high-strength glass, that makes the layers beneath the display less susceptible to damage.

[0016] There is a growing demand for electronic devices with displays that can be reversibly bent or folded. For example, smartphones with foldable displays are becoming increasingly popular because they can reversibly increase screen size during use and fold down to a more compact size for storage. Conventional display cover lenses made of non-flexible glass sheets lack the required level of foldability, thus creating a need for alternative materials and designs for flexible cover lenses. These alternative materials have included sheets of flexible, translucent organic polymers that possess the required foldability. Unfortunately, many of these organic polymers are significantly softer than glass, and the surfaces of these organic polymer cover lenses are easily scratched. Furthermore, many of these organic polymers experience foldability fatigue over time, producing blurred, distorted lines along the fold axis in the displayed image.

[0017] Additional foldable cover lens designs include at least one ultrathin glass (UTG) layer that is significantly more flexible than conventional cover lens glass. These UTG layers can be folded with less folding fatigue, like a sheet made of flexible organic polymer. However, UTG layers are still susceptible to scratching and breakage, and a hard coat layer of high-strength polymer may be attached to the UTG layer to reduce external stress on the cover lens. Conventional methods of attaching the hard coat layer to the underlying UTG layer use a relatively thick layer of optically clear adhesive (OCA). Unfortunately, in many cases, the OCA layer delaminates from the UTG layer along the folding axis when the display device is repeatedly opened and closed. The OCA layer further significantly increases the thickness of the flexible cover lens, which makes it more difficult to fold the display fully.

[0018] Embodiments of this technology solve these and other problems in flexible cover lenses having a hard coat layer bonded to a glass substrate using an optically transparent adhesive. In one embodiment, a thin silicon-containing adhesive layer is used to bond the hard coat layer to a thin glass substrate of the flexible cover lens. In an additional embodiment, the silicon-containing adhesive layer includes a thin inorganic silicon-containing layer formed on the glass substrate by a dry deposition process such as chemical vapor deposition. This deposition process creates a strong bond between the silicon-containing portion of the adhesive layer and the glass substrate. In yet another embodiment, the silicon-containing adhesive layer formed on the glass substrate is exposed to at least one silane-containing adhesion promoter. In one embodiment, the adhesion promoter contacts the surface of the silicon-containing adhesive layer opposite to the surface in contact with the glass substrate. In an additional embodiment, the silane-containing adhesion promoter includes at least one silane portion capable of bonding to silicon groups in the silicon-containing adhesive layer and at least one alkyl group capable of bonding to carbon groups in the hard coat layer. In one embodiment, each silane-containing adhesion promoter is bonded to both the silicon-containing adhesive layer and the hard coat layer. In additional embodiments, the bond between the adhesion promoter and the silicon-containing adhesive layer and hard coat layer is a covalent bond.

[0019] The strong direct bonds formed by each silane-containing adhesion promoter between the silicon-containing adhesive layer and the hard coat layer are less susceptible to delamination than the bonds formed between the adhesive layer and the hard coat layer using optically transparent adhesives. A thick OCA layer placed between the adhesive layer and the hard coat layer contains fewer compounds that form direct bonds with both layers. In most cases, the OCA polymers bonded to each layer are separated by the bulk polymers of the OCA layer. This can make these layers more susceptible to delamination along the folding axis after repeated opening and closing of the cover lens. In contrast, the silicon-containing adhesive layer of this technology containing a silane-containing adhesion promoter has more direct bonds between the promoter compound and both the silicon-containing adhesive layer and the hard coat layer, which reduces delamination of these layers after repeated folding of the cover lens.

[0020] Figure 1 shows an exemplary operation of Method 100 for forming a flexible cover lens according to an embodiment of the present art. Method 100 may be performed in one or more processing chambers. Method 100 may or may not include one or more operations before the commencement of this method, including deposition, etching, polishing, cleaning, or other operations that may be performed before the operations described. This method may include several optional operations that may or may not be explicitly related to some embodiments of the method according to the present art. Method 100 describes operations for forming a portion of the flexible cover lens 200 schematically shown in Figures 2A-2D, and the figures in Figures 2A-2D are described in relation to the operations of Method 100. Figures 2A-2D are only partial schematic diagrams with limited detail, and it should be understood that in some embodiments the cover lens may include any number of structural features having the aspects shown in the figures, and alternative structural features that may similarly benefit from one or more embodiments of the present art.

[0021] Method 100 may include operations for deploying the cover lens structure to a specific manufacturing operation. In some embodiments, Method 100 may be performed on a base structure, but in additional embodiments, this method may be performed before or after other material formation. As shown in Figure 3, an embodiment of the cover lens may include an intermediate pair of layers 303 having enhanced adhesion, positioned between a first pair of layers 301 formed on a hard coat layer 312 and a second pair of layers 305 on which a substrate layer 302 is formed. In further additional embodiments, the cover lens structure including the first pair of layers 301, the intermediate pair of layers 303 and the second pair of layers 305 may be positioned on a flexible display stack 307. Further additional embodiments of the technology are shown in Figure 4, which shows a cover lens 402 incorporated into an electronic display device 400 after additional processing has been completed. For example, the cover lens 402 may be incorporated into the device 400 which further includes a touch panel 410 and a light source 420, among other device features. It should be understood that the apparatus 400 may include any number of components having conductive and / or dielectric materials, including transition metals, post-transition metals, metalloids, metals including oxides, nitrides and carbides of any of these materials, and any other materials that may be incorporated within the apparatus components.

[0022] Embodiments of Method 100 may include, in Operation 102, performing preparations on the substrate surface for depositing a silicon-containing adhesive layer. In embodiments, Operation 102 may include exposing the surface 204 of the substrate layer 202 shown in Figure 2A to a processing plasma. In additional embodiments, the substrate layer 202 may be an ultrathin glass layer exposed to a processing plasma that removes oxidized material from the plasma-treated surface. In additional embodiments, the processing plasma may be formed from a reducing gas such as hydrogen (H2) and ammonia (NH3) and a carrier gas such as helium (He), nitrogen (N2), and argon (Ar). In further additional embodiments, the processing plasma may be formed from a gas containing hydrogen (H2) and argon. In additional embodiments, the processing plasma may be characterized by a plasma temperature of over 300°C or about 300°C, over 325°C or about 325°C, over 350°C or about 350°C, over 375°C or about 375°C, over 400°C or about 400°C, over 425°C or about 425°C, over 450°C or about 450°C, over 475°C or about 475°C, over 500°C or about 500°C, or higher. In further embodiments, the substrate layer 202 may be exposed to the processing plasma for a period of time greater than 1 minute or about 1 minute, greater than 5 minutes or about 5 minutes, greater than 10 minutes or about 10 minutes, greater than 15 minutes or about 15 minutes, greater than 20 minutes or about 20 minutes, greater than 25 minutes or about 25 minutes, greater than 30 minutes or about 30 minutes, greater than 35 minutes or about 35 minutes, greater than 40 minutes or about 40 minutes, greater than 45 minutes or about 45 minutes, greater than 50 minutes or about 50 minutes, or longer. In further embodiments, the substrate layer 202 may be an ultrathin glass layer characterized by a thickness of less than 50 μm or about 50 μm, less than 45 μm or about 45 μm, less than 40 μm or about 40 μm, less than 35 μm or about 35 μm, less than 30 μm or about 30 μm, less than 25 μm or about 25 μm, less than 20 μm or about 20 μm, less than 15 μm or about 15 μm, less than 10 μm or about 10 μm, less than 5 μm or about 5 μm, or less.

[0023] Method 100 may further include, in operation 104, forming a silicon-containing adhesive layer 206 on the treated substrate layer 202. In embodiments, the silicon-containing adhesive layer 206 may be formed by a dry deposition process. In additional embodiments, this dry deposition process may include, among other dry deposition processes, physical vapor deposition (PVD), sputtering, chemical vapor deposition (CVD), plasma chemical vapor deposition (PECVD), high-density plasma chemical vapor deposition (HDP-CVD), atomic layer deposition (ALD), or plasma atomic layer deposition (PE-ALD). In additional embodiments, this dry deposition process may be a PECVD process that includes exposing the treated substrate layer 202 to a deposition plasma formed from a silicon-containing gas and an oxidizing gas. In embodiments, the silicon-containing gas may include, among other silicon-containing plasma deposition gases, silane, or a deposition precursor containing silicon and carbon, such as tetraethyl orthosilicate (TEOS). In additional embodiments, the oxidizing gas may include, in particular, oxygen (O2) and / or nitrous oxide (N2O), among other oxidizing gases. In further additional embodiments, the deposition plasma may further include non-depositing carrier gases, among other carrier gases, such as helium, nitrogen (N2) and / or argon. In additional embodiments, the PECVD process deposits a silicon-containing adhesive layer 206 containing silicon oxide. In further additional embodiments, the deposited silicon oxide material may be characterized by a molar percentage of carbon of less than or about 5 mol%, less than or about 4 mol%, less than or about 3 mol%, less than or about 2 mol%, less than or about 1 mol%, or less than or equal to 5 mol%, 4 mol% or about 4 mol%, 3 mol% or about 3 mol%, 2 mol% or about 2 mol%, 1 mol% or about 1 mol%, or less. In further embodiments, the deposited silicon dioxide material may be characterized by a mole percentage of nitrogen such that it is less than or about 25 mol%, less than or about 15 mol%, less than or about 10 mol%, less than or about 5 mol%, less than or about 2 mol%, less than or about 2 mol%, or less than or less than 2 mol%.

[0024] In these embodiments, the silicon-containing adhesive layer 206 may be formed on the post-processed surface 204 without interrupting the vacuum between the processing operation 102 and the forming operation 104. In these embodiments, the post-processed surface 204 of the substrate layer 202 is not exposed to oxidizing gases and moisture before the silicon-containing adhesive layer 206 is formed on it. This increases the strength of the bond between the silicon-containing adhesive layer 206 and the substrate layer 202. This further reduces moisture and other contaminants in the deposited silicon-containing adhesive layer 206.

[0025] As shown in Figure 2A, the silicon-containing adhesive layer 206 is formed on the treated surface 204 of the substrate layer 202. In embodiments, the silicon-containing adhesive layer 206 may be characterized by a thickness of less than 1000 nm or about 1000 nm, less than 900 nm or about 900 nm, less than 800 nm or about 800 nm, less than 700 nm or about 700 nm, less than 600 nm or about 600 nm, less than 500 nm or about 500 nm, less than 400 nm or about 400 nm, less than 300 nm or about 300 nm, less than 200 nm or about 200 nm, less than 100 nm or about 100 nm, or less. In additional embodiments, the silicon-containing adhesive layer 206 may contain silicon oxide, silicon oxycarbide, silicon oxynitride, silicon nitride, silicon carbide, or silicon oxycarbnitride, among other silicon-containing materials. In additional embodiments, the silicon-containing adhesive layer 206 may feature a refractive index that facilitates the passage of light from a light source through the cover lens containing the adhesive layer without significant image distortion. In additional embodiments, the silicon-containing adhesive layer 206 may feature a refractive index of less than or about 1.55, less than or about 1.52, less than or about 1.50, less than or about 1.48, less than or about 1.45, less than or about 1.43, less than or about 1.40, less than or about 1.38, less than or about 1.35, or less than or equal to these. In further additional embodiments, the silicon-containing adhesive layer 206 may feature a hardness that prevents the cover lens from being easily scratched or dented.In the embodiment, the silicon-containing adhesive layer 206 may be characterized by a hardness of more than 0.1 GPa or about 0.1 GPa, more than 0.5 GPa or about 0.5 GPa, more than 1 GPa or about 1 GPa, more than 1.25 GPa or about 1.25 GPa, more than 1.5 GPa or about 1.5 GPa, more than 1.75 GPa or about 1.75 GPa, more than 2 GPa or about 2 GPa, more than 2.25 GPa or about 2.25 GPa, more than 2.5 GPa or about 2.5 GPa, more than 2.75 GPa or about 2.75 GPa, more than 3 GPa or about 3 GPa, more than 3.25 GPa or about 3.25 GPa, more than 3.5 GPa or about 3.5 GPa, or higher.

[0026] Method 200 may further include, in operation 106, forming a silane-containing adhesion promoter layer 208 on the surface of the silicon-containing adhesive layer 206 or another silicon-containing layer. As shown in Figure 2B, the silane-containing adhesion promoter layer 208 may be formed on the surface of the silicon-containing adhesive layer 206 facing away from the surface of the silicon-containing adhesive layer 206 that came into contact with the post-processed surface 204 of the substrate layer 202. In embodiments, the silane-containing adhesion promoter layer 208 may be formed on the silicon-containing adhesive layer 206 by a wet method. In additional embodiments, the silane-containing adhesion promoter layer 208 may be formed by bringing a solution or vapor containing one or more silane-containing adhesion promoters into contact with the surface of the silicon-containing adhesive layer 206. In further additional embodiments, a solution or vapor of the silane-containing adhesion promoter may be deposited on the silicon-containing adhesive layer 206 by physical vapor deposition, chemical vapor deposition, vacuum deposition, spray coating, spin coating or immersion coating, among other coating techniques. In additional embodiments, a silane-containing adhesion promoter layer may be formed on one or more intermediate layers between the silane-containing adhesion promoter layer 208 and the silicon-containing adhesion layer 206. In embodiments, these one or more intermediate layers may contain a silicon-containing material capable of forming bonds with the silane groups in the silane-containing adhesion promoter.

[0027] In embodiments, a solution of one or more silane-containing adhesion promoters may include an aqueous solution containing more than 0.1% or about 0.1% by mass, more than 0.2% or about 0.2% by mass, more than 0.3% or about 0.3% by mass, more than 0.4% or about 0.4% by mass, more than 0.5% or about 0.5% by mass, or more of the adhesion promoter. The concentration of the adhesion promoter in the aqueous solution may be relatively low in order to adjust the viscosity and surface tension of the solution in order to increase the wettability of the adhesion promoter on the surface of the silicon-containing adhesive layer 206. In additional embodiments, this aqueous solution of adhesion promoters may further contain an acid to adjust the pH of the solution. In some embodiments, the aqueous solution of the adhesion promoter may be characterized by a pH of less than or about 4.5, less than or about 4.4, less than or about 4.3, less than or about 4.2, less than or about 4.1, less than or about 4.0, less than or about 3.9, less than or about 3.8, less than or about 3.7, less than or about 3.6, less than or about 3.5, less than or about 3.4, less than or about 3.3, less than or about 3.2, less than or about 3.1, less than or about 3.0, or less than or equal to these values. In additional embodiments, this acid may be an organic acid such as acetic acid. By adjusting the pH of this aqueous solution of the adhesion promoter, the reactivity between the adhesion promoter and the silicon-containing adhesive layer 206 can be increased.

[0028] In additional embodiments, a moist silane-containing adhesion promoter layer deposited on the silicon-containing adhesive layer 206 may be dried to form a silane-containing adhesion promoter layer 208. In embodiments, this drying process may include heating the deposited adhesion promoter layer in a dry environment characterized by temperatures above or about 100°C, above or about 105°C, above or about 110°C, above or about 115°C, above or about 115°C, above or about 120°C, or higher. In additional embodiments, this drying process may further include exposing the deposited adhesion promoter layer to a dry gas such as dry nitrogen (N2) gas.

[0029] In embodiments, the silane-containing adhesion promoter may be a compound comprising at least one silane moiety bonded to a silicon atom in the silicon-containing adhesive layer 206 and at least one other moiety bonded to the cured hard coat layer 212 subsequently formed on the silicon-containing adhesive layer. In additional embodiments, this at least one silane moiety may comprise an alkylsilane group or an alkoxysilane group, among other types of silane groups. In additional embodiments, this at least one silane moiety may comprise a silicon (Si) atom bonded to one, two, or three alkoxy groups, such as a methoxy group, an ethoxy group, an acetoxy group, or a combination of alkoxy groups. In additional embodiments, this at least one silane moiety may be represented by the formula -Si(OR)3, where R represents an alkyl group having one to four carbon atoms. In additional embodiments, the at least one other moiety bonded to the hard coat layer may comprise one or more amine groups, aldehyde groups, ketone groups, carboxylic acid groups, halogen groups, or alkene groups, among other types of groups that react with the hard coat layer. In further additional embodiments, the silane-containing adhesion promoter may have the formula (RO)3Si-YX, where each R independently represents an alkyl group having 1 to 4 carbon atoms, Y represents a linking group, and X represents at least one portion capable of functioning to bond to the hard coat layer. In further additional embodiments, the Y group may include an alkyl group or an alkoxy group, and at least one X group may independently be an amine group, an aldehyde group, a ketone group, a carboxylic acid group, a halogen group, or an alkene group. In further additional embodiments, the silane-containing adhesion promoter may be 3-aminopropyltriethoxysilane or methacrylateoxypropyltrimethoxysilane, among other silane-containing adhesion promoters.

[0030] In some embodiments, a silane-containing adhesion promoter may be selected that bonds more readily to the silicon-containing adhesive layer 206 than to the substrate layer 202 made from ultrathin glass. In additional embodiments, the treated surface 204 of the substrate layer 202 may have fewer bonding sites to which the silane portion on the adhesion promoter bonds than the silicon-containing adhesive layer 206. In these embodiments, the silicon-containing adhesive layer 206 increases the bonding strength of the silane-containing adhesion promoter that bonds the silicon-containing adhesive layer to the hard coat layer. The increased bonding strength makes these layers less prone to delamination along the folding axis of the cover lens. In additional embodiments, the silane-containing adhesion promoter may covalently bond to one or both of the silicon-containing adhesive layer 206 and the cured hard coat layer 212. In yet another embodiment, the silane-containing adhesion promoter layer 208 may be characterized by the thickness of the silane-containing adhesion promoter constituting the silane-containing adhesion promoter layer.

[0031] Method 200 may further include, in operation 108, depositing a hard coat material 210 on a silicon-containing adhesive layer 206 containing a silane-containing adhesion promoter layer 208. As shown in Figure 2C, the hard coat material 210 may be formed on the surface of the silicon-containing adhesive layer 206 on which the silane-containing adhesion promoter layer 208 is formed. In embodiments, the hard coat material may be characterized as a liquid or gel formed by a wet process on the silicon-containing adhesive layer 206 and the silane-containing adhesion promoter layer 208. In additional embodiments, the hard coat material 210 may be deposited by a wet deposition technique such as spray coating, spin coating, or dipping coating, among other wet deposition techniques.

[0032] In additional embodiments, the hard coat material 210 may include one or more acrylates, one or more sol gels, one or more siloxanes, one or more copolymers thereof, one or more elastomers thereof, or any combination thereof. In additional embodiments, the wet hard coat material 210 includes acrylates which may be radiation-curable acrylates, aliphatic urethane acrylates, copolymers thereof, elastomers thereof, or any combination thereof, or includes acrylates which may be radiation-curable acrylates, aliphatic urethane acrylates, copolymers thereof, elastomers thereof, or any combination thereof. In further additional embodiments, the wet hard coat material 210 includes thermocured acrylates and / or UV-cured acrylates. In additional embodiments, the wet hard coat material 210 includes one or more urethane-acrylates. In further additional embodiments, the wet hard coat material 210 includes one or more urethane-acrylates having the following formula:

[0033] [ka] In the above formula, R may be hydrogen, or an alkyl group having 1 to 5 carbon atoms.

[0034] In additional embodiments, the wet hard coat material 210 may further optionally include one or more inorganic nanoparticles or other fine particles that are replaced or otherwise disposed within the substrate of the hard coat material. In additional embodiments, these inorganic nanoparticles may include one or more of silica, alumina, titanium oxide, zirconium oxide, and hafnium oxide. In further additional embodiments, these inorganic nanoparticles may be nanoparticles characterized by an average particle size of less than or about 500 nm, less than or about 250 nm, less than or about 100 nm, less than or about 90 nm, less than or about 80 nm, less than or about 70 nm, less than or about 60 nm, less than or about 50 nm, or less. In further embodiments, the mass percentage of inorganic nanoparticles in the hard coat material 210 may be less than 75% by mass or about 75%, less than 60% by mass or about 60%, less than 50% by mass or about 50%, less than 40% by mass or about 40%, less than 30% by mass or about 30%, less than 20% by mass or about 20%, less than 10% by mass or about 10%, less than 5% by mass or about 5%, or less.

[0035] In additional embodiments, one or more intermediate material layers may be placed between the silane-containing adhesion promoter layer 208 and the wet hard coat material 210. In embodiments, these intermediate material layers may contain compounds that facilitate the bonding of the hard coat material 210 to the silane-containing adhesion promoter layer 208. In additional embodiments, these materials may contain one or more compounds having chemical groups that form covalent bonds with the silane-containing adhesion promoter, and one or more additional compounds that form covalent bonds with the wet hard coat material 210.

[0036] Method 200 may further include in operation 110 curing the deposited hard coat material 210 to form a cured hard coat layer 212. As shown in Figure 2D, the cured hard coat layer 212 may be located on the surface of a silicon-containing adhesive layer 206 containing a silane-containing adhesion promoter layer 208. In additional embodiments, the silane-containing adhesion promoter may be covalently bonded to the cured hard coat layer 212 and the silicon-containing adhesive layer 206 to strongly bond a group of adjacent layers of the cover lens. In additional embodiments, curing operation 110 may include thermal curing and ultraviolet curing, among other curing techniques. In yet further embodiments, the deposited hard coat material 210 may be dried before or as part of curing operation 110. In embodiments, this drying process may include heating the deposited hard coat material 210 in a dry environment. In yet further embodiments, this drying process may be carried out in the same system or chamber as the drying process for the deposited silane-containing adhesion promoter layer 208.

[0037] In some embodiments, the curing operation 110 may include exposing a wet or dry hard coat material 210 to ultraviolet light. In additional embodiments, this ultraviolet light may feature peak wavelengths of less than or about 400 nm, less than or about 390 nm, less than or about 380 nm, less than or about 370 nm, less than or about 360 nm, less than or about 350 nm, less than or about 330 nm, less than or about 320 nm, less than or about 310 nm, less than or about 300 nm, or less than or equal to these wavelengths. In additional embodiments, the wet or dry hard coat material 210 may be exposed to ultraviolet light for less than 60 minutes or about 60 minutes, less than 45 minutes or about 45 minutes, less than 30 minutes or about 30 minutes, less than 15 minutes or about 15 minutes, less than 10 minutes or about 10 minutes, less than 5 minutes or about 5 minutes, less than 2 minutes or about 2 minutes, less than 1 minute or about 1 minute, or less than that. In additional embodiments, the thickness of the cured hard coat layer may be fixed to a thickness of more than 10 μm or about 10 μm, more than 20 μm or about 20 μm, more than 30 μm or about 30 μm, more than 40 μm or about 40 μm, more than 50 μm or about 50 μm, or greater by completing the curing operation 110.

[0038] As described above, the cured hard coat layer 212 forms a strong bond with the silane-containing adhesion promoter in the silane-containing adhesion promoter layer 208. In embodiments, the bond formed by the silane-containing adhesion promoter between the cured hard coat layer 212 and the silicon-containing adhesive layer 206 may be characterized by a stronger peel strength than that of a similar pair of layers bonded to an optically transparent adhesive polymer. In additional embodiments, the peel strength between the cured hard coat layer 212 and the silicon-containing adhesive layer 206 may be characterized by a 4B to 5B grade according to the ASTM D3359 test requirements.

[0039] In embodiments, the hardened hard coat layer 212 may be a layer of the cover lens that is subjected to the stresses of device use. For the hardened hard coat layer 212 to withstand these stresses and maintain an optically clear, scratch-free viewing surface, this layer should have high hardness properties and an appropriate refractive index. In embodiments where the hardened hard coat layer 212 is part of the flexible cover lens, this layer should further feature excellent bending properties, low bending fatigue, and excellent light transmittance. In embodiments, the hardened hard coat layer 212 may feature a pencil hardness greater than or about 2H, greater than or about 3H, greater than or about 4H, greater than or about 5H, greater than or about 6H, greater than or about 7H, greater than or about 8H, greater than or about 9H, or higher. In additional embodiments, the cured hard coat layer 212 may be characterized by a nano-indentation hardness of greater than or about 0.1 GPa, greater than or about 0.5 GPa, greater than or about 1 GPa, greater than or about 1.25 GPa, greater than or about 1.5 GPa, greater than or about 2 GPa, greater than or about 2.5 GPa, greater than or about 2.5 GPa, greater than or about 3 GPa, greater than or about 3.5 GPa, greater than or about 4 GPa, greater than or about 4.5 GPa, greater than or about 5 GPa, or higher. In further additional embodiments, the cured hard coat layer 212 may feature a refractive index of less than or about 1.55, less than or about 1.52, less than or about 1.50, less than or about 1.48, less than or about 1.45, less than or about 1.43, less than or about 1.40, less than or about 1.38, less than or about 1.35, or less than or about 1.35.

[0040] In additional embodiments, the cured hard coat layer 212 may feature a bending inside radius of less than 20 mm or about 20 mm, less than 15 mm or about 15 mm, less than 10 mm or about 10 mm, less than 7.5 mm or about 7.5 mm, less than 5 mm or about 5 mm, less than 2.5 mm or about 2.5 mm, less than 1 mm or about 1 mm, or less. In additional embodiments, the cured hard coat layer 212 may feature a light transmittance of more than 90% or about 90%, more than 95% or about 95%, more than 96% or about 96%, more than 97% or about 97%, more than 98% or about 98%, more than 99% or about 99%, or higher in the visible part of the spectrum (e.g., wavelengths of about 400 nm to about 700 nm). In further additional embodiments, the flexible cover lens 200 including the cured hard coat layer 212 may feature critical strains of less than or about 15%, less than or about 14%, less than or about 13%, less than or about 12%, less than or about 11%, less than or about 10%, less than or about 9%, less than or about 8%, less than or about 7%, less than or about 6%, less than or about 5%, or less.

[0041] Figure 3 shows another embodiment of the present technology, in which the substrate layer 302, silicon-containing adhesive layer 306, silane-containing accelerator 308, and hard coat layer 312 are at least part of an intermediate set of layers 303 positioned between a first set of layers 301 facing the viewer and a second set of layers facing the flexible display stack 307. The first set of layers 301 positioned above the intermediate set of layers 303 may include one or more layers, among others, such as an additional adhesion-promoting layer, an anti-reflective layer, an additional hard coat layer, and an anti-fingerprint layer. The second set of layers 305 positioned below the intermediate layer 303 may include one or more layers, among others, such as a moisture-proof layer, an impact-absorbing layer, and a glass layer. In this embodiment, the cover lens includes the layers of the first set of layers 301, the intermediate set of layers 303, and the second set of layers 305. In additional embodiments, these layers of the cover lens may be placed on top of the flexible display stack 307.

[0042] In embodiments, the first set of layers 301 may include one or more adhesion-promoting layers disposed on the hard coat layer 312. In additional embodiments, the adhesion-promoting layer may include one or more of silicon oxide, silicon carbide, silicon oxycarbide, silicon nitride, silicon oxynitride, and silicon oxycarbnitride. In additional embodiments, the adhesion-promoting layer may feature a carbon concentration gradient along the thickness of the layer. In further additional embodiments, the surface of the adhesion-promoting layer closer to the hard coat layer 312 or the surface in contact with the hard coat layer 312 may feature a higher carbon concentration than the surface facing the opposite side of the adhesion-promoting layer. In embodiments, the adhesion-promoting layer may feature a carbon concentration of more than 1% by mass or about 1% by mass, more than 2.5% by mass or about 2.5% by mass, more than 5% by mass or about 5% by mass, more than 7.5% by mass or about 7.5% by mass, more than 10% by mass or about 10% by mass, or higher. In further additional embodiments, the adhesion promoting layer may be characterized by a thickness of more than 0.01 μm or about 0.01 μm, more than 0.05 μm or about 0.05 μm, more than 0.1 μm or about 0.1 μm, more than 0.25 μm or about 0.25 μm, more than 0.5 μm or about 0.5 μm, more than 0.75 μm or about 0.75 μm, more than 1 μm or about 1 μm, more than 2 μm or about 2 μm, more than 5 μm or about 5 μm, more than 10 μm or about 10 μm, more than 25 μm or about 25 μm, more than 50 μm or about 50 μm, or greater.

[0043] In further additional embodiments, the first set of layers 301 may include an anti-reflective layer that reduces or prevents the reflection of light from the surface of the cover lens. In embodiments, this anti-reflective layer may include one or more silicon-containing materials, in particular silicon nitride, silicon oxynitride, silicon carbide nitride, and silicon oxycarbide nitride, among other silicon-containing materials. In additional embodiments, the anti-reflective layer may feature a refractive index greater than or about 1.5, greater than or about 1.6, greater than or about 1.7, greater than or about 1.8, greater than or about 1.9, greater than or about 2.0, greater than or about 2.1, greater than or about 2.2, greater than or about 2.3, greater than or about 2.4, greater than or about 2.5, or higher. In further embodiments, the anti-reflective layer may feature an optical transmittance of more than 85% or about 85%, more than 90% or about 90%, more than 95% or about 95%, more than 97.5% or about 97.5%, more than 99% or about 99%, or higher, in the visible range. In further embodiments, the anti-reflective layer may feature a thickness of less than 1000 nm or about 1000 nm, less than 500 nm or about 500 nm, less than 250 nm or about 250 nm, less than 100 nm or about 100 nm, less than 50 nm or about 50 nm, less than 40 nm or about 40 nm, less than 30 nm or about 30 nm, less than 20 nm or about 20 nm, less than 10 nm or about 10 nm, less than 5 nm or about 5 nm, less than 1 nm or about 1 nm, or less.

[0044] In additional embodiments, the first set of layers 301 may further include one or more dry hard coat layers. In embodiments, these dry hard coat layers are characterized as dry because they are formed by one or more types of vapor deposition processes. After deposition or otherwise formed, the dry hard coat layers may be completely dry or substantially dry solid layers. The dry hard coat layers may be PVD, CVD, PE-CVD, HDP-CVD, ALD, PE-ALD, other vacuum or vapor deposition processes, or any combination thereof, or may be deposited, formed, or otherwise produced by vapor deposition processes that may include PVD, CVD, PE-CVD, HDP-CVD, ALD, PE-ALD, other vacuum or vapor deposition processes, or any combination thereof. In some examples, the dry hard coat layer may be generated, deposited, coated or otherwise formed by vacuum processing, atmospheric pressure processing, solution processing, or other deposition or coating techniques, and then optionally treated or cured by heat and / or UV exposure. In one or more embodiments, the dry hard coat layer may be formed, processed and / or otherwise treated on a sheet-to-sheet processing system or a roll-to-roll processing system. For example, the dry hard coat layer may be deposited, coated or otherwise formed on a surface, layer or apparatus below by one or more sheet-to-sheet or roll-to-roll process techniques. In further embodiments, the dry hard coat layer may be characterized by a porosity of less than or about 10 vol% or about 10 vol%, less than or about 9 vol%, less than or about 8 vol%, less than or about 7 vol%, less than or about 6 vol%, less than or about 5 vol%, less than or about 4 vol%, less than or about 3 vol%, less than or about 2 vol%, less than or about 1 vol%, or less than or less than 1 vol%.In further additional embodiments, the dry hard coat layer may feature an inner bending radius of about 1 mm to about 5 mm, an outer bending radius of less than 20 mm or about 20 mm, less than 15 mm or about 15 mm, less than 10 mm or about 10 mm, less than 5 mm or about 5 mm, or less.

[0045] In additional embodiments, the first set of layers 301 may further include an anti-fingerprint layer as the top layer of the flexible cover lens. The anti-fingerprint layer, also known as an anti-fouling layer, may include one or more layers, films, or coatings and provide the top surface of the entire flexible cover lens. The anti-fingerprint layer reduces or prevents fingerprints, dirt, scratches, and other contaminants on the outer and / or top surface of the layer. The anti-fingerprint layer may be fluorosilane, perfluoropolyether-containing silane polymer, chlorosilane, oxysilane, fluoroethylene, perfluoropolyether, nitrogen fluoride or nitrogen-fluorine-containing compounds, polymers of these, dopants of these, or any combination thereof, or may include one or more materials, which may include fluorosilane, perfluoropolyether-containing silane polymer, chlorosilane, oxysilane, fluoroethylene, perfluoropolyether, nitrogen fluoride or nitrogen-fluorine-containing compounds, polymers of these, dopants of these, or any combination thereof.

[0046] In some embodiments, a second set of layers 305 may include a moisture-proof layer. In additional embodiments, this moisture-proof layer may be one or more films, coatings, or other layers having inherent moisture-proof or waterproof properties and being bendable, flexible, and / or foldable. In yet further embodiments, the moisture-proof layer may include one or more layers such as a moisture-proof and / or waterproof vapor layer, a high surface energy layer (e.g., hydrophilic properties), a planarizing layer, an encapsulation layer, a portion of these layers, or a combination thereof. In one or more embodiments, the moisture-proof layer may be silicon oxide, silicon nitride, silicon oxynitride, dopants thereof, or any combination thereof, or may include one or more materials that may include silicon oxide, silicon nitride, silicon oxynitride, dopants thereof, or any combination thereof. In additional embodiments, the moisture barrier may consist of a single layer, while in yet further additional embodiments, the moisture barrier may consist of multiple sublayers, such as two, three, four, five, six, seven, eight, nine, or ten or more sublayers. In embodiments, the moisture barrier may consist of multiple sublayers included in the moisture barrier, for example, more than two or about two sublayers, more than three or about three sublayers, more than four or about four sublayers, more than five or about five sublayers, or more sublayers. In yet further additional embodiments, the moisture barrier may consist of a membrane stack having three or more sublayers, such as a first sublayer, a second sublayer, and a third sublayer, where the second sublayer is positioned between the first and second sublayers. In this embodiment, the film stack may be a SiN / SiO / SiN stack, where the first sublayer may be silicon nitride or contain silicon nitride, the second sublayer may be silicon oxide or contain silicon oxide, and the third sublayer contains silicon nitride. In this embodiment, the moisture barrier layer is 10 g / m² 2 Less than a day or approximately 10g / m² 2 day, 5g / m 2 Less than a day or approximately 5g / m² 2 day, 1g / m 2 Less than a day or approximately 1 g / m 2 day, 0.5g / m 2 Less than a day or approximately 0.5 g / m²2 per day, 0.1 g / m 2 per day less than or about 0.1 g / m 2 per day, 0.01 g / m 2 per day less than or about 0.01 g / m 2 per day, 0.1 g / m 2 per day less than or about 0.1 g / m 2 per day, 0.1 g / m 2 per day less than or about 0.1 g / m 2 per day, 0.01 g / m 2 per day less than or about 0.01 g / m 2 per day, 0.001 g / m 2 per day less than or about 0.001 g / m 2 per day, 0.0001 g / m 2 per day less than or about 0.0001 g / m 2 per day, 0.00001 g / m 2 per day less than or about 0.00001 g / m 2 per day, 0.000001 g / m 2 per day less than or about 0.000001 g / m 2 per day, or a water vapor transport rate less than or equal thereto, may also be characterized.

[0047] In additional embodiments, a second set of layers 305 may include an impact-absorbing layer. In additional embodiments, this impact-absorbing layer may include one or more layers that are bendable, flexible, and / or foldable and used to absorb vibration or shock. In additional embodiments, the impact-absorbing layer may be ether urethane, ester urethane, aliphatic urethane, aliphatic polyurethane, aliphatic polyester urethane, thermosetting polysulfide, polyamide, copolymers thereof, elastomers thereof, or any combination thereof, or may include one or more materials that may include ether urethane, ester urethane, aliphatic urethane, aliphatic polyurethane, aliphatic polyester urethane, thermosetting polysulfide, polyamide, copolymers thereof, elastomers thereof, or any combination thereof. In additional embodiments, the impact-absorbing layer may be characterized by a thickness of less than 250 μm or about 250 μm, less than 200 μm or about 200 μm, less than 150 μm or about 150 μm, less than 100 μm or about 100 μm, less than 50 μm or about 50 μm, less than 25 μm or about 25 μm, less than 10 μm or about 10 μm, or less. In yet further embodiments, the impact-absorbing layer may include an elastomer layer having a thickness of less than 100 μm or about 100 μm, less than 75 μm or about 75 μm, or less.

[0048] In further additional embodiments, a second pair of layers 305 may include a glass layer. In additional embodiments, the surface of this glass layer may be in contact with the flexible display stack 307. In additional embodiments, the glass layer may be an optically clear or transparent glass layer characterized by a thickness of less than 200 μm or about 200 μm, less than 150 μm or about 150 μm, less than 100 μm or about 100 μm, less than 90 μm or about 90 μm, less than 80 μm or about 80 μm, less than 70 μm or about 70 μm, less than 60 μm or about 60 μm, less than 50 μm or about 50 μm, less than 40 μm or about 40 μm, less than 30 μm or about 30 μm, less than 20 μm or about 20 μm, less than 10 μm or about 10 μm, or less.

[0049] Method 200 may further include, in operation 112, incorporating a cover lens comprising a substrate layer 202, a silicon-containing adhesive layer 206, and a cured hard coat layer 212 into the electronic display. Figure 4 shows a simplified schematic cross-sectional view of an electronic display 400 according to an embodiment of the art, including a cover lens 402 positioned on an assembly of additional elements within the electronic display. These additional elements may include a contrast-enhancing and / or polarizer layer 404, a touch panel 406, a display layer 408 including a light source (not shown), a substrate layer 410, and a backing film 412. These layers together can make a bendable or foldable electronic display for electronic devices such as smartphones, monitors, televisions, tablets, laptop computers, or watches, among other types of electronic devices.

[0050] In some embodiments, the contrast-enhancing and / or polarizer layer 404 may include a multifunctional film layer containing a polarizer film. In additional embodiments, the contrast-enhancing and / or polarizer layer 404 may be used to reduce unwanted reflections from reflective metals forming electrode lines or metal structures within the electronic display 400. In yet another embodiment, the contrast-enhancing and / or polarizer layer 404 may include a quarter-wavelength retarder and a linear polarizer formed from a flexible lens film having a thickness of less than 0.2 mm or about 0.2 mm.

[0051] In additional embodiments, the touch panel 406 may include a touch sensor IC board and a touch sensor (not shown). In additional embodiments, the touch sensor IC board is a metal-based flexible printed circuit board. In yet additional embodiments, the display layer 408 may include one or more light-emitting diode (LED) displays, one or more liquid crystal displays (LCDs) or other suitable display devices. In additional embodiments, the display layer 408 may include an organic light-emitting diode (OLED) display. In yet additional embodiments, the display layer 408 may include a quantum dot (OD) display. In additional embodiments, the display layer 408 may include a thin-film encapsulation (TFE), an organic light-emitting layer, a driver IC board, and thin-film transistors (TFTs).

[0052] In additional embodiments, the substrate layer 410 may include a flexible substrate made of plastic or polymer. In embodiments, the substrate layer 410 may be transparent and / or colorless, and in some examples may be conductive. The substrate layer 410 may include one or more polyimide materials, polyester terephthalate, polyetheretherketone, transparent conductive polyester, polycarbonate, polyaryletherketone, or any combination thereof. In additional embodiments, the backing film 412 may include one or more heat sink layers and / or one or more protective barrier layers.

[0053] Embodiments of this technology include a method for manufacturing a flexible cover lens with reduced bending fatigue and folding fatigue, which is due, in part, to a silicon-containing adhesive layer that makes the cover lens less susceptible to distortion and delamination. In embodiments, the silicon-containing adhesive layer includes a silane-containing adhesion promoter that facilitates a strong bond between the adhesive layer and the hard coat layer, protecting the components beneath the display from environmental stress as well as normal wear and tear. In additional embodiments, a silicon-containing adhesive layer containing a silane-containing adhesion promoter is used instead of conventional optically transparent adhesives, which are characterized by weak bonding between the hard coat layer and the layer beneath it, for example, between the hard coat layer and the ultrathin glass substrate layer.

[0054] In the above description, for explanatory purposes, numerous details have been included to provide an understanding of various embodiments of the Art. However, it will be apparent to those skilled in the art that certain embodiments can be carried out without some of these details, or with additional details.

[0055] While several embodiments have been disclosed, those skilled in the art should recognize that various modifications, alternative structures, and equivalents can be used without departing from the spirit of the embodiments. Furthermore, some well-known processes and elements have not been described in order to avoid unnecessarily obscuring the Art. Therefore, the above description should not be considered as limiting the scope of the Art. In addition, while methods or processes may be described sequentially or as steps, it should be understood that these operations may be performed simultaneously or in an order different from that described.

[0056] Where a range of values ​​is provided, unless it is evident from the context that each value falling between the upper and lower limits of that range is also specifically disclosed, down to the smallest fractional unit of the lower limit. Narrower ranges between the specified values ​​or unspecified values ​​falling between them in the specified range and other specified values ​​or values ​​falling between them in that specified range are also included. The upper and lower limits of those smaller ranges may independently be included in or excluded from that range, and each range that includes either limit, does not include either limit, or includes both limits is also included in the Art according to the specifically excluded limits of the specified range. If the specified range includes one or both of these limits, the range that excludes one or both of the limits that they include is also included.

[0057] As used herein and in the appended claims, the singular forms "a," "an," and "the" include plural references unless it is evident from the context. Thus, for example, a reference to "an adhesion promoter" includes multiple such promoters, and a reference to "the layer" includes one or more layers and their equivalents known to those skilled in the art, etc.

[0058] Furthermore, as used herein and in the following claims, the words “comprise(s),” “comprising,” “contain(s),” “containing,” “include(s),” and “including” are intended to specify the presence of an expressly expressed feature, complete, component, or operation, but they do not preclude the presence or addition of one or more other features, complete, component, operation, act, or base.

Claims

1. The surface of the substrate layer is exposed to a surface treatment plasma to form the treated surface of the substrate layer, A silicon-containing adhesive layer is deposited on the treated surface of the substrate layer, The silicon-containing adhesive layer is made to incorporate a silane-containing adhesion promoter, The process involves forming a hard coat layer on the silicon-containing adhesive layer, wherein the silane-containing adhesion promoter is bonded to both the hard coat layer and the silicon-containing adhesive layer. A flexible cover lens processing method including the following.

2. The flexible cover lens processing method according to claim 1, wherein the surface treatment plasma includes oxygen and argon.

3. The flexible cover lens processing method according to claim 1, wherein the treated surface of the substrate layer is not exposed to air before the silicon-containing adhesive layer is deposited on the treated surface.

4. The flexible cover lens processing method according to claim 1, wherein the silicon-containing adhesive layer is deposited on the treated surface of the substrate layer by plasma chemical vapor deposition.

5. The flexible cover lens processing method according to claim 1, wherein the silane-containing adhesion promoter includes a liquid that has been spray-coated or immersed on the silicon-containing adhesive layer.

6. The flexible cover lens processing method according to claim 1, wherein the silane-containing adhesion promoter further comprises a methacrylate group.

7. Forming the hard coat layer on the silicon-containing adhesive layer is The process involves coating the silicon-containing adhesive layer with a liquid hard coat polymer, wherein the silane-containing adhesion promoter is incorporated into the silicon-containing adhesive layer. The liquid hard coat polymer coated on the silicon-containing adhesive layer is cured to form the hard coat layer on the silicon-containing adhesive layer. A flexible cover lens processing method according to claim 1, including the method described in claim 1.

8. The flexible cover lens processing method according to claim 7, wherein curing the liquid hard coat polymer coated on the silicon-containing adhesive layer further includes exposing the liquid hard coat polymer to ultraviolet light.

9. The substrate layer, A silicon-containing adhesive layer in contact with the surface of the substrate layer, comprising a silicon-containing adhesive layer and a silane-containing adhesion promoter, A hard coat layer on the silicon-containing adhesive layer, wherein the hard coat layer and the substrate layer are arranged on opposite sides of the silicon-containing adhesive layer, and the silane-containing adhesion promoter is bonded to the hard coat layer and the silicon-containing adhesive layer. A flexible cover lens equipped with this feature.

10. The flexible cover lens according to claim 9, wherein the substrate layer includes a glass layer having a thickness of 50 μm or less.

11. The flexible cover lens according to claim 9, wherein the silicon-containing adhesive layer includes a silicon oxide layer having a thickness of 1 μm or less.

12. The flexible cover lens according to claim 9, wherein the silane-containing adhesion promoter comprises an acrylicoxyalkylsilane compound.

13. The flexible cover lens according to claim 9, wherein the hard coat layer comprises a urethane acrylate polymer characterized by a thickness of 50 μm or less.

14. A flexible cover lens according to claim 9, which does not contain an optically transparent adhesive.

15. A flexible display structure including a light source, A flexible cover lens disposed on the aforementioned flexible display structure, Equipped with, The aforementioned flexible cover lens is A glass layer characterized by a thickness of 50 μm or less, A silicon-containing adhesive layer on the surface of the glass layer, A hard coat layer on the silicon-containing adhesive layer, wherein the hard coat layer and the glass layer are arranged on opposite sides of the silicon-containing adhesive layer, and a silane-containing adhesion promoter contributes to bonding the hard coat layer to the silicon-containing adhesive layer, A flexible display device having the following features.

16. The flexible display apparatus according to claim 15, wherein the silicon-containing adhesive layer includes a silicon oxide layer.

17. The flexible display apparatus according to claim 15, wherein the silane-containing adhesion promoter comprises an acrylicoxyalkylsilane compound.

18. The flexible display device according to claim 15, wherein the flexible cover lens is characterized by having a thickness of 100 μm or less.

19. The flexible display device according to claim 15, wherein the flexible display structure further includes a touch panel.

20. The flexible display apparatus according to claim 15, wherein the light source includes a light-emitting diode, an organic light-emitting diode, a liquid crystal display, or a quantum dot display.

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