Optical laminate, transparent display comprising same, and manufacturing method therefor

Abstract

The present invention relates to an optical laminate, a transparent display comprising same, and a manufacturing method therefor, the optical laminate comprising: a transparent first substrate; an adhesive layer formed on the first substrate; a metal layer pattern positioned on the adhesive layer; a light-emitting diode (LED) positioned on the metal layer pattern; a transparent second substrate positioned on the light-emitting diode (LED); and a transparent resin layer formed between the transparent first substrate and second substrate, wherein: the transparent first substrate and second substrate are glass substrates; the thickness of the transparent resin layer positioned on the light-emitting diode (LED) is 100 to 400% of the thickness of the light-emitting diode (LED), and the thickness of the second substrate is 150 to 2200% of the transparent resin layer positioned on the light-emitting diode (LED); and the refractive index of the transparent resin layer is 1.5 or less.

Description

Optical laminate, transparent display including same, and method for manufacturing same

[0001] The present invention relates to an optical laminate, a transparent display including the same, and a method for manufacturing the same.

[0002]

[0003] Recent technological advancements in the display market have led to a growing demand for large-area display devices. Light-emitting diodes (LEDs) are being used as billboards and electronic displays in various locations, including department stores, stores, and shopping malls. Transparent LED displays, in particular, are installed on building exterior walls and windows to display advertisements and various information. Glass- or PET (Polyester)-based transparent LED displays form circuit wiring on the PET film and arrange colored LEDs. When current is applied to the colored LEDs, the LEDs emit light. To enhance the transparency and visibility of transparent LED displays, it is necessary to reduce the visibility of the wiring while simultaneously arranging the colored LEDs more densely.

[0004] Republic of Korea Patent No. 10-1789126 also discloses a method for manufacturing a large-area display of an LED display board using a PET substrate.

[0005] However, although conventional transparent display technology uses transparent substrates and transparent electrodes for clear display, there is a problem that the image is not clear due to reflection from adjacent unlit LEDs caused by the light from the lit LED, and therefore, there is a need to develop a transparent display structure that can improve the light bleeding phenomenon.

[0006]

[0007] The purpose of the present invention is to provide an optical laminate that can improve visibility and display a screen with enhanced clarity by reducing light scattering of a transparent display that occurs when light from a light-emitting diode (LED) mounted on a substrate and turned on is reflected to an adjacent light-emitting diode (LED) that is turned off.

[0008] In addition, the present invention aims to provide a method for manufacturing the optical laminate and transparent display.

[0009]

[0010] The present invention comprises: a transparent first substrate; an adhesive layer formed on the first substrate; a metal layer pattern positioned on the adhesive layer; a light emitting diode (LED) positioned on the metal layer pattern; a transparent second substrate positioned on the light emitting diode (LED); and

[0011] The present invention relates to an optical laminate comprising a transparent resin layer formed between the transparent first substrate and the second substrate, wherein the transparent first substrate and the second substrate are each independently glass or ceramic substrates, the thickness of the transparent resin layer positioned on the light emitting diode (LED) is 100 to 400% of the thickness of the light emitting diode (LED), the thickness of the second substrate is 150 to 2200% of the thickness of the transparent resin layer positioned on the light emitting diode (LED), and the refractive index of the transparent resin layer is 1.5 or less.

[0012] In one embodiment of the present invention, the metal layer pattern may have a stripe structure.

[0013] In one embodiment of the present invention, the light emitting diode (LED) may include red (R), green (G), and blue (B) pixels.

[0014] In one embodiment of the present invention, the transparent resin layer may include silicone.

[0015] In one embodiment of the present invention, the spacing between the light emitting diodes (LEDs) may be 3 mm to 20 mm.

[0016] In one embodiment of the present invention, the optical laminate includes a plurality of light emitting diodes (LEDs), and when one light emitting diode (LED) is turned on and an adjacent light emitting diode (LED) is turned off, the luminance measured from the adjacent light emitting diode (LED) may be 3.8 cd / ㎡ or less.

[0017] In one embodiment of the present invention, the first substrate and the second substrate may be glass.

[0018] In one embodiment of the present invention, when the first substrate and the second substrate are glass, they may each independently be at least one selected from quartz, borosilicate, aluminosilicate, alkali-free glass, soda lime glass, mesh glass, colored glass, magic mirror, and holographic glass.

[0019] In one embodiment of the present invention, when the second substrate is glass, it may further include one or more selected from mesh glass, colored glass, magic mirror, and holographic glass.

[0020] In one embodiment of the present invention, the metal layer may include at least one selected from the group consisting of copper (Cu), aluminum (Al), nickel (Ni), chromium (Cr), silver (Ag), iron (Fe), gold (Au), cobalt (Co), titanium (Ti), and tungsten (W).

[0021] In another embodiment of the present invention, there is provided a transparent display including the optical laminate.

[0022] In addition, the present invention comprises a step of preparing a metal thin film including an adhesive layer formed on one surface of a metal layer, a first protective film provided on one surface of the adhesive layer, and a second protective film provided on the other surface of the metal layer, a step of peeling off the first protective film of the metal thin film, a step of bonding the metal thin film so that the adhesive layer is disposed on one surface of a transparent first substrate, a step of peeling off the second protective film of the metal thin film, a step of patterning the metal layer to form a metal layer pattern,

[0023] A step of forming a transparent second substrate so as to face the first substrate; and

[0024] A step of forming a transparent resin layer between the first substrate and the second substrate is included,

[0025] The step of forming the transparent resin layer includes a step of applying the transparent resin layer positioned on the light emitting diode (LED) so that the thickness thereof is 100 to 400% of the thickness of the light emitting diode (LED), and a step of applying the second substrate so that the thickness thereof is 150 to 2200% of the thickness of the transparent resin layer positioned on the light emitting diode (LED), and a method for manufacturing an optical laminate in which the refractive index of the transparent resin layer is 1.5 or less.

[0026] In another embodiment of the present invention, the step of forming the metal layer pattern may include the step of forming a photoresist pattern on one surface of the metal layer, the step of etching an exposed area of ​​the metal layer by the photoresist pattern, and the step of peeling the photoresist pattern.

[0027]

[0028] The optical laminate and transparent display according to the present invention have the effect of improving light scattering by reducing the illuminance reaching the turned-off light-emitting diode (LED) by increasing the optical path length of reflected light using the distance from the light-emitting diode (LED) mounted on the substrate to the surface of the optical laminate and the refractive index of the transparent resin layer injected between the substrates.

[0029]

[0030] FIG. 1 is a diagram showing the structure of an optical laminate according to one or more embodiments of the present invention.

[0031] Figure 2 is a diagram showing the internal optical path of an optical laminate to which the present invention is not applied.

[0032] Figure 3 is a diagram of an internal optical path according to the configuration of Example 1 among the experimental examples of the present invention.

[0033] In the above diagram, each symbol represents the following:

[0034] 10: Metal layer pattern

[0035] 21: First substrate

[0036] 22: Second substrate

[0037] 30: Resin layer

[0038] 40: Solder layer

[0039] 50: LED

[0040] 51: 1st LED

[0041] 52: 2nd LED

[0042] 60: Organic layer

[0043]

[0044] The present invention relates to an optical laminate comprising a transparent first substrate, an adhesive layer formed on the first substrate, a metal layer pattern positioned on the adhesive layer, a light-emitting diode (LED) positioned on the metal layer pattern, a transparent second substrate positioned on the light-emitting diode (LED), and a transparent resin layer formed between the transparent first substrate and the second substrate. More specifically, the present invention relates to an optical laminate wherein the transparent first substrate and the second substrate are glass substrates, the thickness of the transparent resin layer positioned on the light-emitting diode (LED) is 100 to 400% of the thickness of the light-emitting diode (LED), the thickness of the second substrate is 150 to 2200% of the thickness of the transparent resin layer positioned on the light-emitting diode (LED), and the refractive index of the transparent resin layer is 1.5 or less, a transparent display including the same, and a manufacturing method thereof. When manufacturing a transparent display including the above optical laminate, by increasing the length of the light path reflected from a light-emitting diode (LED) mounted on a substrate and turned on to an adjacent light-emitting diode (LED) that is turned off, the illuminance reaching the adjacent turned-off light-emitting diode (LED) is reduced, thereby manufacturing an optical laminate that reduces light scattering, and the transparent display including the above optical laminate can display a screen with significantly improved visibility and enhanced clarity.

[0045] Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings. However, the following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the contents of the invention described above, serve to further understand the technical concept of the present invention. Therefore, the present invention should not be interpreted as being limited to the matters described in such drawings.

[0046] The terms used herein are for the purpose of describing embodiments and are not intended to limit the present invention. In this specification, singular forms also include plural forms, unless specifically stated otherwise. For example, "protective film" as used herein may refer to at least one of the first protective film and the second protective film.

[0047] As used herein, the terms "comprises" and / or "comprising" are used to mean that they do not exclude the presence or addition of one or more other components, steps, operations, and / or elements other than the components, steps, operations, and / or elements mentioned. Like reference numerals refer to like elements throughout the specification.

[0048] Spatially relative terms such as “below,” “bottom,” “lower,” “above,” “top,” and “upper” can be used to easily describe the relationship between one element or component and other elements or components, as depicted in the drawings. Spatially relative terms should be understood to include different orientations of the elements during use or operation in addition to the orientation depicted in the drawings. For example, if an element depicted in a drawing is flipped over, an element described as “below” or “lower” of another element may end up “above” the other element. Thus, the exemplary term “below” can include both the above and below directions. Elements can also be oriented in other directions, and thus spatially relative terms can be interpreted based on their orientation.

[0049] As used herein, “substantially” may be interpreted to include not only physically identical or identical, but also within the range of error in the measurement or manufacturing process, for example, it may be interpreted to mean an error range of 0.1% or less.

[0050]

[0051] < Optical laminate and transparent display >

[0052] An optical laminate according to one or more embodiments of the present invention may include a transparent substrate, an adhesive layer, a metal layer pattern, a light emitting diode (LED), and a resin layer. In addition, a transparent display of the present invention may include the optical laminate.

[0053] The above transparent substrate, specifically the transparent first substrate and the transparent second substrate, may be a glass substrate and / or a ceramic substrate having secured flatness and a transmittance of 89% or more. More specifically, the transparent substrate is not particularly limited as long as it does not impair the optical properties of the optical laminate, and may include, for example, oxide glass such as silicate glass, borate glass, or phosphate glass. In this case, there is an advantage in that heat shrinkage phenomena, etc. do not occur in subsequent processes, and a predetermined hardness can be imparted to the optical laminate.

[0054] In one embodiment of the present invention, the first substrate and the second substrate may be glass. In addition, when the first substrate and the second substrate are glass, each may be independently used without limitation in the scope of application, such as quartz, borosilicate, aluminosilicate, alkali-free glass, soda lime glass, mesh glass, colored glass, magic mirror, and holographic glass.

[0055] At this time, the shape can be used without being limited to a specific shape such as a wafer or a square plate.

[0056] Additionally, when the second substrate is glass, it may further include one or more selected from mesh glass, colored glass, magic mirror, and holographic glass.

[0057] Referring to FIG. 1, which illustrates the structure of an optical laminate according to one or more embodiments of the present invention, the optical laminate of the present invention includes a transparent first substrate (21), a metal layer pattern (10) formed on the first substrate, a solder layer (40) formed on the metal layer pattern, a light emitting diode (50) mounted on the solder layer, a transparent second substrate (22), and a resin layer (30) formed by injecting a transparent resin between the first substrate and the second substrate. Preferably, the transparent second substrate is positioned on the light emitting diode (LED), and more specifically, may be positioned to cover all of the light emitting diode (LED), the metal layer pattern, and the adhesive layer, and may be positioned at the outermost portion of the optical laminate. At this time, the surface of the second substrate may be the surface of the optical laminate and the transparent display.

[0058]

[0059] In one or more embodiments, the glass substrate may have a thickness of 0.5 mm to 20 mm. When the thickness of the glass substrate satisfies the above range, the glass substrate can be made thin while having excellent hardness, and can prevent deformation or cracking of the metal layer. Specifically, when the thickness is less than 0.5 mm, it may be difficult to protect the metal layer or other laminated members from external impact, and when it exceeds 20 mm, it may be disadvantageous in terms of thinning or weight reduction.

[0060] In one or more embodiments, the glass substrate may have a single-layer or multi-layer structure. For example, the glass substrate may have a single-layer structure formed by a single glass substrate, but is not necessarily limited thereto, and may have a multi-layer structure in which a plurality of glass substrates are laminated.

[0061] In one embodiment, the optical laminate may include an adhesive layer on one surface of the glass substrate.

[0062]

[0063] The adhesive layer may be manufactured from an adhesive layer composition containing a silicone-based adhesive. The adhesive layer composition of the present invention contains a silicone-based additive and a solvent, and may further contain additives.

[0064] The above additive may be one or more of an anchorage, a cross linker, and a catalyst.

[0065] The above anchorage is added to increase the bonding strength with the metal layer during adhesive layer coating, thereby preventing the adhesive layer from being separated from the metal layer. Generally, there are no particular limitations on the material used as the anchorage, but it is preferable that it does not undergo thermal deformation at temperatures below 200°C.

[0066] The above crosslinking agent is a substance added for chemical bonding between components of the adhesive layer composition, and is preferably a product that does not undergo thermal deformation at 200°C or lower.

[0067] The above catalyst is a component added for curing the adhesive layer composition, and helps the adhesive layer composition transform from a liquid phase to a solid phase. Specific examples include a platinum catalyst, a palladium catalyst, and / or an osmium catalyst.

[0068] It is preferable from the viewpoint of adhesive stability that the additive of the present invention is included in an amount of 0.1% to 10% based on the total weight of the adhesive layer composition.

[0069] The adhesive layer of the present invention may be formed by heating and curing the adhesive layer composition at a temperature of 100°C to 180°C.

[0070] The adhesive layer may have a thickness of 5 μm to 50 μm, and preferably, a thickness of 5 μm to 30 μm. If the thickness of the adhesive layer is less than 5 μm, sufficient adhesive strength with other materials cannot be maintained, and if it exceeds 50 μm, there may be a disadvantage in terms of increasing the thickness of the product.

[0071] The above metal layer may be used as an electrode in an electronic device such as a display device including the optical laminate.

[0072] The metal layer is not particularly limited as long as it has electrical conductivity, and may include, for example, one or more selected from the group consisting of copper (Cu), aluminum (Al), nickel (Ni), chromium (Cr), silver (Ag), iron (Fe), gold (Au), cobalt (Co), titanium (Ti), and tungsten (W).

[0073] The above metal layer may be formed by a known metal thin film process, for example, by preparing and attaching a metal thin film, or by using at least one method selected from the group consisting of electroless deposition, electrodeposition, sputtering, thermal evaporation, and electron beam evaporation, but is not limited thereto.

[0074] The metal layer may have a thickness of 3 µm to 120 µm, preferably 3 µm to 110 µm, and more preferably 18 µm to 105 µm. If the thickness of the metal layer is less than 3 µm, it may not be easy to form a uniform thin film or pattern, and if it exceeds 120 µm, there may be a problem in that it cannot be applied to an electronic device having a thin film structure.

[0075] In addition, an organic layer (60) may be further included on the adhesive layer in a portion where the metal layer pattern is not formed, i.e., on the upper portion of the adhesive layer exposed as the metal layer is etched when the metal layer pattern is formed.

[0076] The above resin layer is formed by injecting a transparent resin (OCR) between the transparent first substrate and the second substrate, and is not particularly limited as long as it has operating heat stability, blocking of internal organic leaching materials such as LED packages, solder paste, and copper foil adhesives, moisture resistance, and heat resistance. The transparent resin is a transparent material that transmits light emitted from a light-emitting diode (LED), and may be a UV-curable or thermosetting composition, and preferably may include silicone.

[0077] More specifically, the transparent resin used in one embodiment of the present invention includes silicone and acrylic, and the refractive index of the resin layer formed can be controlled by adjusting the ratio of the silicone and acrylic. Preferably, the refractive index of the transparent resin layer may be lower than the refractive index of the second substrate, and more preferably, when the refractive index of the second substrate, which is a glass substrate, is 1.55, the refractive index of the transparent resin layer may be 1.5 or less.

[0078]

[0079] The light emitting diode (LED) of the present invention can be applied to any known light emitting diode (LED) without limitation. Specifically, the light emitting diode (LED) may include red (R), green (G), and blue (B) pixels, and the interval between the light emitting diodes (LEDs) mounted on the substrate of the optical laminate manufactured using the present invention may be 3 mm to 20 mm. For example, in one embodiment of the present invention, any light emitting diode (LED) mounted on the first substrate has an adjacent light emitting diode (LED), and the adjacent light emitting diode (LED) may be another light emitting diode (LED) at a distance that is affected in terms of brightness by the lighting of any of the light emitting diodes (LED), and for example, may be an LED that is present within 3 mm to 20 mm.

[0080] The optical laminate of the present invention may include a first substrate having a plurality of light-emitting diodes (LEDs) mounted thereon, and referring to FIG. 2, which is an internal optical path diagram according to the configuration of Comparative Example 1 among the experimental examples of the present invention, in the case of a conventional optical laminate, when the first LED (51) is turned on and the adjacent second LED (52) is turned off, light from the first LED (51) may be reflected from the surface of the second substrate and directed to the turned off second LED (52). At this time, when the light reflected by the second LED (52) is emitted outside the transparent display, a light bleed phenomenon occurs. The present invention improves this light bleed phenomenon by increasing the length of the optical path by utilizing the characteristic that illuminance is inversely proportional to the square of the distance from the light source. Specifically, in the case of an optical laminate manufactured by applying the present invention, it is preferable that the luminance measured at the second LED (52) satisfies 3.8 cd / ㎡ or less.

[0081] Referring to FIG. 3, which is a schematic diagram of an internal optical path according to the configuration of Example 1 of the experimental example of the present invention, it can be seen that by increasing the thickness of the second substrate, the optical path of the light reflected from the lit first LED (51) to the turned-off second LED (52) becomes longer, and therefore the amount of light reaching the turned-off adjacent light-emitting diode (LED), the second LED (52), is reduced. This is based on the principle that illuminance is inversely proportional to the square of the distance. In order to reduce the amount of light reaching the second LED (52), in addition to increasing the thickness of the second substrate as shown in FIG. 3, the thickness and refractive index of the transparent resin layer formed between the first substrate and the second substrate can also be adjusted.

[0082] Specifically, the thickness of the transparent resin layer positioned on the light-emitting diode (LED) may be 100 to 400% of the thickness of the light-emitting diode (LED), the thickness of the second substrate may be 150 to 2200% of the thickness of the transparent resin layer positioned on the light-emitting diode (LED), and the refractive index of the transparent resin layer may be 1.5 or less. When manufacturing a transparent display using the present invention, it is preferable that the thickness of the light-emitting diode (LED), the transparent resin layer, and the thickness of the second substrate satisfy the above ratio. At this time, the transparent resin layer positioned on the light-emitting diode (LED) refers to the thickness of the resin layer filled from the uppermost surface of the mounted light-emitting diode (LED) to the second substrate.

[0083] In addition, since the reflectivity of light from a light emitting diode (LED) decreases as the angle of incidence (θ) with respect to the surface of the second substrate decreases, and the amount of light reaching an adjacent light emitting diode (LED) decreases, when manufacturing a transparent display using the present invention, it is preferable that the refractive index of the transparent resin layer satisfies a value smaller than 1.5, which is the refractive index of glass generally used in displays. Specifically, referring to FIG. 3, the process in which light from a first LED (51) heads to an adjacent light emitting diode (LED) is such that it passes through the resin layer, reaches the surface of the second substrate, is reflected, and then passes through the resin layer again to proceed toward the second LED (52). Accordingly, when the refractive index of the second substrate according to one embodiment of the present invention is 1.55 and the refractive index of the transparent resin layer is 1.5 or less, the optical path in FIG. 3 increases according to Snell's law at the boundary between the low-refractive layer (transparent resin layer) and the high-refractive layer (second substrate) due to an increase in the incident angle of the low-refractive layer, and the incident angle (θ) toward the surface of the second substrate decreases and the reflectivity decreases, resulting in a decrease in the amount of light reaching the second LED (52).

[0084]

[0085] <Method for manufacturing optical laminate>

[0086] The method for manufacturing the optical laminate of the present invention is not particularly limited as long as it is a method for manufacturing the optical laminate described above.

[0087] A method for manufacturing an optical laminate according to an embodiment of the present invention may include the steps of: preparing a metal thin film including a silicone-based adhesive layer formed on one surface of a metal layer, and including a first protective film provided on one surface of the silicone-based adhesive layer and a second protective film provided on the other surface of the metal layer; peeling off the first protective film of the metal thin film; bonding the metal thin film so that the adhesive layer is disposed on one surface of a glass substrate; peeling off the second protective film of the metal thin film; patterning the metal layer to form a metal layer pattern; forming a transparent second substrate to face the first substrate; and forming a transparent resin layer between the first substrate and the second substrate.

[0088] More preferably, the step of forming the transparent resin layer may include a step of applying the transparent resin layer positioned on the light emitting diode (LED) so that the thickness thereof is 100 to 400% of the thickness of the light emitting diode (LED), and applying the second substrate so that the thickness thereof is 150 to 2200% of the thickness of the transparent resin layer positioned on the light emitting diode (LED). In addition, the refractive index of the transparent resin layer may be 1.5 or less.

[0089] Specifically, the step of peeling off the first protective film provided on the metal thin film may be peeling off the first protective film disposed on the lower surface of the adhesive layer of the metal thin film.

[0090]

[0091] The above protective film may be provided to protect the surface of the metal layer and / or the adhesive layer from the outside, and may be provided in the form of, for example, a first protective film formed on one side of the adhesive layer to protect the surface of the adhesive layer, and a second protective film formed on one side of the metal layer to protect the surface of the metal layer.

[0092] In one embodiment, the protective film may be used as a single-layer structure formed of one layer, but is not limited thereto, and may also be used as a multi-layer structure in which one or more protective films are continuously laminated.

[0093] In one embodiment, the protective film may be formed by laminating a second protective film and a first protective film on one surface of the metal layer and the adhesive layer, respectively, using a laminator.

[0094] The above protective film is not particularly limited as long as it is for protecting the surface of the metal layer and / or the adhesive layer, and for example, polyethylene terephthalate (PET), polyethylene isophthalate (PEI), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), diacetyl cellulose, triacetyl cellulose (TAC), polycarbonate (PC), polyethylene (PE), polypropylene (PP), polymethyl acrylate (PMA), polyimide (PI), polymethyl methacrylate (PMMA), polyethyl acrylate (PEA), polyethyl methacrylate (PEMA), and cyclic It may include at least one selected from the group consisting of cyclic olefin polymers (COPs), and in terms of ease of acquisition and processing convenience, polyethylene terephthalate (PET), triacetyl cellulose (TAC), polycarbonate (PC), polyimide (PI), and cyclic olefin polymers (COPs) can be preferably used.

[0095] The thickness of the above protective film is not particularly limited and may be, for example, 10 μm to 200 μm.

[0096] Meanwhile, the metal thin film described above is an example of a metal thin film having a protective film on one side of the metal layer and the adhesive layer, but is not limited thereto, and for example, may include only one protective film among the protective film formed on one side of the metal layer and the protective film formed on one side of the adhesive layer.

[0097] The step of peeling off the first protective film provided on the above metal thin film may be peeling off the first protective film disposed on the lower surface of the adhesive layer of the metal thin film.

[0098] The peeling of the above first protective film can be appropriately performed within a range that does not harm the purpose of the present invention, and a method used in a conventional peeling process of a release film can also be used.

[0099] The step of bonding a metal thin film so that an adhesive layer is disposed on one surface of the glass substrate may be bonding a surface of the adhesive layer exposed to the outside by peeling off the first protective film onto one surface of the glass substrate.

[0100] Bonding of the above adhesive layer and the glass substrate can be appropriately performed within a range that does not harm the purpose of the present invention, and can be bonded using, for example, a laminator or the like.

[0101] The step of peeling off the second protective film provided on the above metal thin film may be peeling off the second protective film disposed on the upper surface of the metal layer of the metal thin film.

[0102] The peeling of the second protective film may be performed by substantially the same method as the peeling of the first protective film.

[0103] Meanwhile, the method for manufacturing the optical laminate described above is described by way of example, a method for manufacturing the optical laminate using a metal thin film, but is not necessarily limited thereto.

[0104] For example, in another embodiment of the present invention, if the metal thin film does not have a second protective film, the step of peeling off the second protective film provided on the metal thin film may be omitted.

[0105] The step of forming a metal layer pattern of an optical laminate according to one embodiment of the present invention may include the steps of forming a photoresist pattern on one surface of the metal layer; etching an exposed area of ​​the metal layer by the photoresist pattern; and peeling off the photoresist pattern.

[0106] Specifically, the step of forming a photoresist pattern on one surface of the metal layer may include a step of applying a composition for forming a photoresist pattern onto the metal layer by spin coating, slit coating, inkjet printing, etc., a step of drying and heat-treating the applied composition for forming a photoresist pattern to form a photoresist film, and a step of selectively exposing and developing the photoresist film to dissolve and remove the photoresist film corresponding to an exposed area or a non-exposed area, thereby forming a photoresist pattern.

[0107] The step of forming the above photoresist pattern can be performed by a known method, and details are omitted.

[0108] The step of etching the exposed area of ​​the metal layer by the above photoresist pattern is not particularly limited and may be performed by a dry etching process or a wet etching process.

[0109] In one embodiment, the wet etching process may be performed using an etchant including at least one selected from the group consisting of nitric acid, phosphoric acid, and acetic acid. As described above, the adhesive layer is characterized by including a silicon-based adhesive, and thus has excellent chemical resistance to an etchant including at least one selected from the group consisting of nitric acid, phosphoric acid, and acetic acid. Therefore, when the etching process is performed by wet etching using an etchant including at least one selected from the group consisting of nitric acid, phosphoric acid, and acetic acid, not only is the etching performance for the metal layer excellent, but even if the adhesive layer located under the metal layer is exposed to the etchant, damage (physical and chemical damage and clouding phenomenon) to the adhesive layer may not occur.

[0110] The above dry etching process or wet etching process can be performed by a known method, and details are omitted.

[0111] The step of stripping the above photoresist pattern may be performed by immersing the substrate on which the resist pattern is formed in a resist stripping solution, or by spraying the stripping solution onto the substrate. In addition, in this case, physical processing such as ultrasonic irradiation or contact with a brush that rotates or swings left and right may be used in combination.

[0112]

[0113] In one embodiment, the resist stripping conditions may be a temperature of about 15°C to 100°C, preferably 30°C to 70°C, and the immersion or spraying time may be preferably about 1 minute to 20 minutes, but is not limited thereto and may be appropriately modified according to the needs of the user.

[0114] In one embodiment, after the resist stripping solution treatment, an additional cleaning process may be performed to remove any stripping solution remaining on the substrate. The cleaning process may be performed in the same manner as the stripping process described above, except that water or isopropyl alcohol is used instead of the stripping solution.

[0115]

[0116] Transparent Display and Manufacturing Method

[0117] The present invention includes a transparent display manufactured using the optical laminate of the present invention described above and a manufacturing method thereof.

[0118] Specifically, the present invention relates to a transparent display including the optical laminate described above and a light-emitting diode (LED). FIG. 1 is a diagram showing an example of the transparent display of the present invention. Referring to FIG. 1, the transparent display of the present invention has a form in which a light-emitting diode (LED) is formed in an opening in a patterned metal layer of the optical laminate where an organic layer is not formed. More specifically, a portion of the patterned metal layer of the metal thin film substrate where an organic layer is not formed may further include a solder layer (40), and a light-emitting diode (LED) (50) may be mounted through the solder layer. The arrangement interval or density of the light-emitting diodes (LEDs) is not particularly limited, but may be arranged in a grid shape. In this case, the upper, lower, left, and right intervals may be 1 to 50 mm, preferably 3 to 20 mm, and the intervals of a plurality of light-emitting diodes (LEDs) may be the same or different from each other. When a light emitting diode (LED) is formed on the metal thin film substrate of the present invention, there is an advantage as a transparent display capable of transmitting and reproducing images on a substrate having transparency.

[0119]

[0120] In addition, the method for manufacturing a transparent display of the present invention includes a step of mounting a light-emitting diode (LED) on the optical laminate described above. According to an example of the present invention, the method for manufacturing a transparent display may further include a step of mounting a light-emitting diode (LED) (50) on a portion of the patterned metal layer of the optical laminate of the present invention where the organic layer (60) is not formed.

[0121] In the present invention, the method of forming a light emitting diode (LED) in the optical laminate of the present invention may use a method of surface mounting the element by soldering (SMT: Surface Mount Technology), but is not limited thereto.

[0122]

[0123] The present invention further includes a structure and method comprising an overcoat layer covering the upper portion of the light-emitting diode (LED) or the entire transparent display. The overcoat layer may be made of any material known in the art without limitation, and its thickness is not particularly limited as long as it is within the range commonly applied by those skilled in the art.

[0124] The optical laminate of the present invention, by exhibiting the above-described characteristics, can be suitably used in display devices requiring large areas and low resistance, and in particular, has the advantage of being particularly suitable for use in devices that can be exposed to the external environment for long periods of time, such as transparent displays, in terms of excellent heat resistance and reliability in high temperature and high humidity environments.

[0125]

[0126] Hereinafter, experimental examples including specific examples and comparative examples are presented to help understand the present invention, but these are only illustrative of the present invention and do not limit the scope of the appended claims. It will be apparent to those skilled in the art that various changes and modifications to the examples are possible within the scope and technical idea of ​​the present invention, and it is natural that such changes and modifications fall within the scope of the appended claims. In addition, "%" and "part" indicating the content below are based on weight unless specifically stated.

[0127]

[0128] Examples and Comparative Examples: Fabrication of Optical Laminates

[0129] Example 1

[0130] A flat substrate, a 35㎛ thick copper foil, is attached to the substrate with an adhesive, and then a metal layer pattern is formed on the copper foil by a photo / etching process, and tin plating is performed on the upper part of the copper foil to provide the visual characteristics of copper and the adhesive strength for soldering the LED. The metal layer pattern is composed of data and power wiring, a Land part to which the LED is attached, and a PAD to which the FPCB is attached, and an organic layer formed on the upper part of the metal layer pattern includes an acrylic component. The part of the patterned metal layer of the metal thin film substrate where the organic layer is not formed further includes a solder layer, and a light emitting diode (LED) is mounted through the solder layer. Thereafter, an optical laminate was manufactured through the steps of attaching DAM TAPE to the edge of the first substrate, laminating a glass substrate (refractive index: 1.55) as a second substrate facing the first substrate, and injecting and curing a transparent resin between the laminated first and second substrates. The above transparent resin was prepared by adding 95 parts by weight of biphenylmethyl acrylate (M1192, Miwon Specialty Chemical Co.) as an acrylic monomer and 5 parts by weight of 4-hydroxybutyl acrylate as a crosslinking monomer to prepare an acrylic copolymer, then adding 0.5 parts by weight of (1-hydroxycyclohexyl) phenyl ketone (Irgacure®-184) as an initiator to the prepared acrylic copolymer to prepare an acrylic composition, and adding 60 parts by weight of PDMS (Poly(dimethylsiloxane), vinyl terminated, Merck), 39.8 parts by weight of the above acrylic composition, and 0.2 parts by weight of a platinum catalyst.

[0131]

[0132] Examples 2 to 7

[0133] Optical laminates of Examples 2 to 7 were manufactured in the same manner as in Example 1, except that the thickness of the second substrate and the thickness of the transparent resin layer were adjusted as shown in Table 1.

[0134]

[0135] Example 8

[0136] An optical laminate of Example 8 was produced in the same manner as Example 1, except that a transparent resin composition of 99.8 parts by weight of the PDMS and 0.2 parts by weight of a platinum-based catalyst was used.

[0137]

[0138] Example 9

[0139] An optical laminate of Example 9 was produced in the same manner as Example 1, except that a transparent resin composition of 45 parts by weight of the PDMS, 54.8 parts by weight of the acrylic composition, and 0.2 parts by weight of a platinum-based catalyst was used.

[0140]

[0141] Comparative Example 1

[0142] In the above Example 1, an optical laminate of Comparative Example 1 was manufactured in the same manner as in Example 1 except that a transparent resin composition of 20 parts by weight of the PDMS, 79.8 parts by weight of the acrylic composition, and 0.2 parts by weight of a platinum-based catalyst was used.

[0143]

[0144] Comparative Example 2

[0145] In the above Example 1, an optical laminate of Comparative Example 2 was manufactured in the same manner as in Example 1 except that the thickness of the second substrate, the thickness of the transparent resin (OCR), and the refractive index of the transparent resin (OCR) were adjusted as shown in Table 1, using a transparent resin composition of 40 parts by weight of the PDMS, 59.8 parts by weight of the acrylic composition, and 0.2 parts by weight of the platinum-based catalyst.

[0146]

[0147] Experimental Example - Luminance Evaluation

[0148] For the optical laminates of the examples and comparative examples, the level of light scattering was quantified by measuring the luminance of the second LED, which is an adjacent, turned-off LED, after turning on the first LED of the wiring line 1.

[0149] Luminance measurement was performed using TOPCON SR-UL1R equipment, measuring the luminance of the LED at a distance of 50 cm and a measurement angle of 1°.

[0150]

[0151] Experimental Example - Refractive Index Evaluation

[0152] The transparent resin compositions according to the above-described examples and comparative examples were coated on a slide glass (manufactured by Matsunami Glass Kogyo, model number: S1111) using a bar coater. Thereafter, the composition was cured by exposing it to 4000 mJ / cm2 based on 365 nm using a curing device (metal halide lamp, short-wavelength cut filter applied) in a nitrogen environment, thereby producing a transparent resin having a thickness of 50 ㎛.

[0153] For the transparent resins according to the above-described examples and comparative examples, the refractive index was measured using an Abbe refractometer (DMM4, manufactured by ATAGO) by irradiating them with sodium D line in an atmosphere of 25°C. The measurement results are shown in Table 1 below.

[0154] Second substrate thickness (mm) Second substrate thickness / LED upper resin layer thickness Total resin layer thickness (mm) LED upper resin layer thickness LED upper resin layer thickness / LED thickness Distance (mm) Transparent resin refractive index Second LED luminance (cd / ㎡) Example 1 3 600% 10.5 100% 3.5 1.47 3.6 Example 2 4 800% 10.5 100% 4.5 1.47 2.9 Example 3 5 1000% 10.5 100% 5.5 1.47 3 Example 4 6 1200% 10.5 100% 6.5 1.47 2 Example 5 7 1400% 10.5 100% 7.5 1.47 1.2 Example 6 3 300% 1.5 1200% 41.47 3.5 Example 7 3 1 50% 2.5 2 400% 5 1 4 7 3.2 Example 8 3 600% 10.5 100% 3.5 1 4 3.2 Example 9 3 600% 10.5 100% 3.5 1 5 3.8 Example 10 1 1 2 2 00% 10.5 100% 11.5 1 4 7 2.0 Comparative Example 1 3 600% 10.5 100% 3.5 1 5 5 4.2 Comparative Example 2 3 600% 10.5 100% 3.5 1 5 1 3.9

[0155] - Distance: The distance from the top of the light-emitting diode (LED) to the surface of the second substrate.

[0156] -LED height: 0.5mm

[0157] -Light spread evaluation (off LED brightness measurement)

[0158] - Second substrate refractive index: 1.55

[0159]

[0160] Referring to Table 1 and FIG. 3, in the case of an embodiment in which the height of the light-emitting diode (LED) mounted on the first substrate is 0.5 mm, the thickness of the transparent resin layer positioned on the light-emitting diode (LED) is 100 to 400% of the thickness of the light-emitting diode (LED), the thickness of the second substrate is 150 to 2200% of the thickness of the transparent resin layer positioned on the light-emitting diode (LED), and the refractive index of the transparent resin layer is 1.5 or less, it can be confirmed that the luminance measured from the second LED (52) is 3.8 cd / ㎡ or less.

[0161] On the other hand, in the case of Comparative Examples 1 and 2, the thickness of the second substrate is 600% of the thickness of the transparent resin layer positioned on the light emitting diode (LED), which satisfies the preferred range of the present invention, but the refractive index of the transparent resin layer is 1.55 and 1.51, which does not satisfy the refractive index of 1.5 or less, so it can be confirmed that the luminance measured from the second LED (52) appears brighter than 3.8 cd / ㎡.

[0162]

[0163]

[0164] The optical laminate and transparent display according to the present invention have the effect of improving light scattering by reducing the illuminance reaching the turned-off light-emitting diode (LED) by increasing the optical path length of reflected light using the distance from the light-emitting diode (LED) mounted on the substrate to the surface of the optical laminate and the refractive index of the transparent resin layer injected between the substrates.

Claims

1. Transparent first substrate; An adhesive layer formed on top of the first substrate; A metal layer pattern positioned on the above adhesive layer; A light emitting diode (LED) positioned on the above metal layer pattern; A transparent second substrate positioned above the light emitting diode (LED); and An optical laminate comprising a transparent resin layer formed between the transparent first substrate and the second substrate, The above transparent first substrate and second substrate are each independently a glass or ceramic substrate, The thickness of the transparent resin layer positioned above the light emitting diode (LED) is 100 to 400% of the thickness of the light emitting diode (LED), The thickness of the second substrate is 150 to 2200% of the thickness of the transparent resin layer positioned above the light-emitting diode (LED), An optical laminate having a refractive index of 1.5 or less of the transparent resin layer.

2. In claim 1, The above metal layer pattern is an optical laminate having a stripe structure.

3. In claim 1, The above light emitting diode (LED) is an optical laminate including red (R), green (G), and blue (B) pixels.

4. In claim 1, The above transparent resin layer is an optical laminate containing silicon.

5. In claim 1, An optical laminate in which the spacing between the light emitting diodes (LEDs) is 3 mm to 20 mm.

6. In claim 1, The above optical laminate comprises a plurality of light emitting diodes (LEDs), When one light emitting diode (LED) lights up and the adjacent light emitting diode (LED) turns off, An optical laminate having a luminance of 3.8 cd / ㎡ or less as measured from the adjacent light-emitting diodes (LEDs).

7. In claim 1, The above first substrate and second substrate are an optical laminate made of glass.

8. In claim 1, An optical laminate wherein the first and second substrates are glass, each independently selected from at least one of quartz, borosilicate, aluminosilicate, non-alkali glass, soda lime glass, meshed glass, colored glass, magic mirror, and holographic glass.

9. In claim 1, An optical laminate, wherein the second substrate is made of glass, and further comprises at least one selected from mesh glass, colored glass, magic mirror, and holographic glass.

10. In claim 1, An optical laminate, wherein the metal layer comprises at least one selected from the group consisting of copper (Cu), aluminum (Al), nickel (Ni), chromium (Cr), silver (Ag), iron (Fe), gold (Au), cobalt (Co), titanium (Ti), and tungsten (W).

11. A transparent display comprising an optical laminate according to any one of claims 1 to 10.

12. A step for preparing a metal thin film including an adhesive layer formed on one surface of a metal layer, a first protective film provided on one surface of the adhesive layer, and a second protective film provided on the other surface of the metal layer; A step of peeling off the first protective film of the above metal thin film; A step of bonding the metal thin film so that an adhesive layer is disposed on one surface of a transparent first substrate; A step of peeling off the second protective film of the above metal thin film; A step of forming a metal layer pattern by patterning the metal layer; A step of forming a transparent second substrate so as to face the first substrate; and A step of forming a transparent resin layer between the first substrate and the second substrate is included. The step of forming the above transparent resin layer is: The thickness of the transparent resin layer positioned on the light emitting diode (LED) is applied so that it is 100 to 400% of the thickness of the light emitting diode (LED). A step of applying the second substrate so that the thickness thereof is 150 to 2200% of that of the transparent resin layer positioned on top of the light-emitting diode (LED), A method for manufacturing an optical laminate, wherein the refractive index of the transparent resin layer is 1.5 or less.

13. In claim 12, The step of forming the above metal layer pattern includes a step of forming a photoresist pattern on one surface of the metal layer; A step of etching the exposed area of ​​the metal layer by the above photoresist pattern; and A method for manufacturing an optical laminate, comprising: a step of peeling off the photoresist pattern.

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