Heating defrosting substrate and manufacturing method therefor

Abstract

The present invention relates to a heating defrosting substrate and a manufacturing method therefor. A heating defrosting substrate according to one embodiment of the present invention comprises at least one thin film glass, wherein at least one surface of the thin film glass includes a heating pattern formed by patterning. The thin film glass can be bonded on opposite surfaces to an upper glass substrate and a lower glass substrate.

Description

Heating defrosting substrate and method of manufacturing the same

[0001] The present invention relates to a heating defrosting substrate and a method for manufacturing the same, and more specifically, to a heating defrosting substrate and a method for manufacturing the same for removing frost and preventing condensation in automobiles, aircraft, building windows, displays, optical devices, etc.

[0002] In general, in applications such as automobiles, aircraft, architectural windows, displays, and optical devices, condensation or frost may form on glass surfaces due to changes in the external environment, and a thermal defrosting function is required to prevent this. To implement this, conventional methods have mainly involved inserting a film with a heating pattern between two panes of glass or embedding a tungsten wire. These methods generate heat when an electric current is applied, enabling the effective removal of condensation or frost from the glass surface.

[0003] However, in methods using heating films, a problem may arise where the film's haze increases during the glass bonding process. In particular, there is a possibility that the film's optical properties may change during the glass bonding process, which could consequently lead to a decrease in visibility.

[0004] In addition, when using tungsten wire, the wire pattern may be visible, so it may not be suitable for applications where high transmittance and clear visibility are important.

[0005] As such, existing heat defrosting technologies have limitations, including degradation of optical properties and visibility issues, and there is a need to improve them.

[0006] The present invention aims to provide a heating defrosting substrate and a method for manufacturing the same, which can secure long-term reliability while maintaining visibility and uniform heating performance by forming a heating pattern on a thin film glass and bonding glass to glass using an adhesive layer.

[0007] A heating defrosting substrate according to one embodiment of the present invention comprises at least one thin film glass, and at least one surface of the thin film glass comprises a heating pattern formed by a patterning process, and the thin film glass is bonded to both sides with an upper glass substrate and a lower glass substrate.

[0008] In one embodiment, the thin film glass may be formed with a thickness of 0.2 mm or more and 1 mm or less.

[0009] In one embodiment, a transparent electrode layer may be formed on the upper part of the heating pattern.

[0010] In one embodiment, the heating pattern may include any one of a line pattern, a grid pattern, and a wave pattern.

[0011] In one embodiment, the heating pattern is divided into a plurality of independent heating zones, and each heating zone can control the temperature individually.

[0012] In one embodiment, when a heating pattern is formed on both sides of the thin film glass, the temperature can be individually controlled for the heating pattern on each side.

[0013] In one embodiment, the heating pattern can control the temperature distribution by adjusting the density of the pattern in the central region and the edge region.

[0014] In one embodiment, a protective layer may be included on the total surface of the thin film glass containing the heating pattern.

[0015] In one embodiment, the double-sided bonding is achieved by an adhesive layer, and the adhesive layer is formed in a multilayer structure, and the adhesive layer adjacent to the thin film glass may be formed from a material with higher resistance to thermal shock.

[0016] In one embodiment, the double-sided bonding is achieved by an adhesive layer, and the adhesive layer may include a functional coating material to selectively transmit or block light of a specific wavelength.

[0017] In one embodiment, the adhesive layer may be any one of PVB (Polyvinyl Butyral), EVA (Ethylene Vinyl Acetate), TPU (Thermoplastic Polyurethane), Ionomer, PU (Polyurethane), and PDMS (Polydimethylsiloxane), or a mixture of two or more of these.

[0018] In one embodiment, a low-reflection coating layer may be formed on one or both sides of any one or more of the upper glass substrate and the lower glass substrate.

[0019] A method for manufacturing a heat-generating defrosting substrate according to one embodiment of another aspect of the present invention may include the steps of preparing at least one thin film glass, forming a heat-generating pattern on at least one surface of the thin film glass using a patterning process, and bonding the thin film glass to both sides with an upper glass substrate and a lower glass substrate.

[0020] In one embodiment, the step of forming the heating pattern may be performed by a photolithography process or a laser patterning process.

[0021] In one embodiment, the step of forming the heating pattern may include forming a metal layer on the thin film glass, performing a patterning process of the metal layer, and forming a transparent electrode on the metal layer.

[0022] In one embodiment, after the step of forming the heating pattern, the method may include the step of additionally forming a protective layer on the total surface of the thin film glass containing the heating pattern.

[0023] According to one embodiment of the present invention, by applying a structure that forms a heating pattern directly on a thin film glass and bonds both sides with an upper glass substrate and a lower glass substrate through an adhesive layer, the problems of optical degradation and visibility associated with conventional heating film methods can be improved.

[0024] According to one embodiment of the present invention, by directly forming a heating pattern on a thin film glass, the problem of haze increase occurring in conventional heating film methods can be minimized. This allows for the effective implementation of a heating function while maintaining optical transmittance by not using a film in the glass bonding process.

[0025] In addition, while conventional metal wire methods can provide heating performance, they are not suitable for applications where visibility is important because the metal wires are likely to be visible to the naked eye. In one embodiment of the present invention, a fine heating pattern can be formed directly on a thin film glass by a patterning process, thereby providing excellent heating performance while maintaining high optical transmittance.

[0026] In addition, according to one embodiment of the present invention, the temperature distribution can be uniformly controlled by adjusting the density of the heating pattern or by configuring a plurality of independent heating regions. By adjusting the density of the heating pattern in the central and edge regions, the problem of temperature imbalance can be resolved, and since a plurality of independent heating patterns can be controlled individually, efficient power management and precise temperature control are possible.

[0027] Accordingly, according to one embodiment of the present invention, a heat-generating defrosting substrate having excellent optical properties, superior mechanical stability, and a uniform temperature distribution can be provided. This enables the resolution of problems arising from conventional heat-generating film and metal wire methods, while also allowing for the implementation of more reliable heat-generating defrosting technology in various application fields such as automobiles, railways, buildings, and cameras.

[0028] FIG. 1 is a schematic diagram of a heat-generating defrosting substrate according to one embodiment of the present invention.

[0029] FIG. 2 is a schematic diagram of a heat-generating defrosting substrate according to another embodiment of the present invention.

[0030] FIG. 3 is a schematic diagram of a heating pattern (line type) formed on a thin film glass according to one embodiment of the present invention.

[0031] FIG. 4 is a schematic diagram of a heating pattern (grid type) formed on a thin film glass according to one embodiment of the present invention.

[0032] FIG. 5 is a schematic diagram of a heating pattern (wavy type) formed on a thin film glass according to one embodiment of the present invention.

[0033] FIG. 6 is a schematic diagram of a heat-generating defrosting substrate according to another embodiment of the present invention.

[0034] Figure 7 illustrates an example of partitioning the heating area in the embodiment of Figure 3.

[0035] Figure 8 illustrates an example of partitioning the heating area in the embodiment of Figure 4.

[0036] FIG. 9 illustrates an example of partitioning the heating area in the embodiment of FIG. 5.

[0037] FIG. 10 is a schematic diagram of a heat-generating defrosting substrate according to another embodiment of the present invention.

[0038] FIG. 11 illustrates an example in which the density of the heat generation pattern is formed differently in the central region and the edge region according to another embodiment of the present invention.

[0039] FIG. 12 is a schematic diagram of a heat-generating defrosting substrate according to another embodiment of the present invention.

[0040] FIG. 13 is a schematic diagram of a heat-generating defrosting substrate according to another embodiment of the present invention.

[0041] FIG. 14 is a schematic diagram of a heat-generating defrosting substrate according to another embodiment of the present invention.

[0042] FIG. 15 is a flowchart of a heat-releasing method according to one embodiment of the present invention.

[0043] The present invention aims to provide a heating defrosting substrate and a method for manufacturing the same, which can ensure long-term reliability while maintaining high visibility and uniform heating performance by directly forming a heating pattern on a thin film glass and bonding glass to glass using an adhesive layer.

[0044] 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 are intended to illustrate preferred embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the aforementioned description; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings.

[0045] In this specification, the singular form includes the plural form unless specifically stated otherwise. Throughout the specification, the same reference numerals refer to the same components.

[0046] As used herein, "comprises" and / or "comprising" are used in the sense that they do not exclude the presence or addition of one or more other components, elements, and / or devices other than the mentioned components, elements, and / or devices.

[0047] Spatially relative terms such as "below," "bottom," "lower side," "top," "top surface," and "upper side" may be used to easily describe the relationship between one element or component and another element or component as illustrated in the drawings. Spatially relative terms should be understood as terms that include different directions of the element during use or operation, in addition to the directions illustrated in the drawings.

[0048] For example, if an element depicted in a drawing is flipped, an element described as being "below" or "lower side" of another element may be placed "above" the other element. Therefore, the exemplary term "below" may include both the lower and upper directions.

[0049] As used in this specification, the term "connection" includes both indirectly and directly connecting multiple components, and is used to include both physically and electrically connecting components.

[0050]

[0051] FIG. 1 is a schematic diagram of a heat-generating defrosting substrate according to one embodiment of the present invention.

[0052] As illustrated in FIG. 1, a heating defrosting substrate according to one embodiment of the present invention comprises at least one thin film glass (100), and at least one surface of the thin film glass (100) comprises a heating pattern (200) formed by a patterning process, and the thin film glass (100) can be bonded on both sides to an upper glass substrate (610) and a lower glass substrate (620) through an adhesive layer (500).

[0053] A thin film glass (100) according to one embodiment of the present invention has high optical transmittance, maintains mechanical strength to stably form a heating pattern (200), and has physical properties that maintain stable characteristics in a glass bonding process.

[0054] Specifically, the thin film glass (100) may be made of soda-lime glass, borosilicate glass, aluminosilicate glass, etc.

[0055] A thin film glass (100) according to one embodiment of the present invention may adopt a single thin film glass (100) having a heating pattern (200) within a heating defrosting substrate as a basic structure, but may also apply a plurality of thin film glasses (100) as shown in FIG. 2.

[0056] When multiple thin film glasses (100) are applied, different heating patterns (200) can be formed on each thin film glass (100). For example, a heating pattern (200) that intensively heats the central area is formed on the first thin film glass (100), and a heating pattern (200) that heats the edge area is formed on the second thin film glass (100) so that the temperature distribution can be adjusted more precisely. As a result, the defrosting effect can be implemented more efficiently than with a conventional single thin film glass (100) structure, and customized heating for specific fields can be achieved.

[0057] In addition, when multiple thin film glasses (100) are applied, different optical and mechanical properties can be applied to each thin film glass (100), thereby further improving the performance of the heating substrate. For example, the first thin film glass (100) may be designed to have high thermal conductivity to rapidly dissipate heat, and the second thin film glass (100) may include a functional coating layer that filters light of a specific wavelength. Through this, heating performance and optical performance can be improved.

[0058] In addition, when multiple thin film glasses (100) are applied, the structural strength can be further increased. While a single thin film glass (100) structure may be relatively weak against stress or impact generated during the manufacturing process, if multiple thin film glasses (100) are stacked, each layer acts to distribute stress, thereby improving the overall mechanical strength. In particular, since it is important to increase durability in applications exposed to external environments such as automobiles, railways, and construction, applying a multilayer structure utilizing multiple thin film glasses (100) can satisfy these requirements.

[0059] When bonding multiple thin film glasses (100), a single-layer adhesive layer (500) or a multi-layer adhesive layer (500) can be applied to control the bonding strength between each thin film glass (100) and to provide a role of mitigating thermal shock in a specific layer. For example, PVB (Polyvinyl Butyral) or EVA (Ethylene Vinyl Acetate) can be arranged in a multi-layer structure as the adhesive layer (500) to control the spacing between thin film glasses (100) containing a heat generation pattern (200), thereby ensuring electrical insulation and mechanical stability.

[0060]

[0061] In addition, the thin film glass (100) according to one embodiment of the present invention may have a thickness of approximately 0.2 mm or more and 1 mm or less.

[0062] Here, if the thickness of the thin film glass (100) is less than 0.2 mm, the possibility of breakage may increase due to physical fragility. The thin film glass (100) is a material that is brittle due to the characteristics of the glass substrate, and if the thickness is too thin, cracks may easily occur even with a small impact. In particular, if the thickness of the thin film glass (100) is less than 0.2 mm, there is a risk that the thin film glass (100) will crack during the process of forming the heating pattern (200) (e.g., photolithography process, laser patterning process, etc.), and it may not be easy to handle as it is an ultra-thin plate.

[0063] For example, during the process of forming a heat-generating pattern (200), while processes such as photosensitive coating, exposure, development, deposition, and physical and chemical etching are being carried out, thin film glass (100) with a thickness of less than 0.2 mm may be deformed during these chemical and physical processes. In particular, when laser energy is directly transferred to the thin film glass (100) during laser patterning, there is a risk that the glass layer may form microcracks or suffer structural damage due to thermal stress at a thin thickness. Additionally, if the thin film glass (100) is excessively thin, the bonding strength with the adhesive layer (500) may be weakened. According to one embodiment, the thin film glass (100) is bonded to an upper glass substrate (610) and a lower glass substrate (620) through a compression process using PVB or EVA, and thin film glass (100) with a thickness of less than 0.2 mm may be deformed or broken by the bonding pressure.

[0064] In addition, if the thin film glass (100) exceeds 1 mm, refraction may occur as light passes through during the photolithography process, and the thick glass layer may cause pattern distortion during exposure. Even during laser patterning, there is a possibility that laser energy may be absorbed or scattered into the glass, resulting in non-uniform pattern formation.

[0065] In addition, it is desirable that the thickness of the thin film glass (100) not exceed 1 mm in order to maintain optical properties. As the thickness increases, the scattering and absorption rates of light increase, and there is a possibility that the transmittance of visible light will decrease. In particular, if the thickness exceeds 1 mm, multiple reflections may occur inside the glass, and visibility may be reduced.

[0066] In addition, the heat-dissipating substrate according to one embodiment of the present invention is used in various application environments such as automobiles, railways, buildings, and camera lenses, and lightweighting is an important factor. If the thickness exceeds 1 mm, the weight of the substrate increases, which may be disadvantageous when applied to portable devices (e.g., cameras, smart windows, etc.).

[0067] In addition, more preferably, the thickness of the thin film glass can be set to 0.3 mm or more and 0.9 mm or less. Even more preferably, the thickness of the thin film glass can be set to 0.4 mm or more and 0.8 mm or less. Even more preferably, the thickness of the thin film glass can be set to 0.5 mm or more and 0.7 mm or less. This is done considering optical properties and heat generation performance.

[0068] In this way, in one embodiment of the present invention, the thickness of the thin film glass (100) is set to 0.2 mm or more and 1 mm or less, taking into consideration mechanical strength, patterning precision, bonding stability, optical properties, and heat generation performance. Through this, stable formation and maintenance of the heat generation pattern (200) is possible, and it can be effectively applied in application environments such as automobiles, railways, architecture, and camera lenses.

[0069]

[0070] And according to one embodiment of the present invention, at least one surface of the thin film glass (100) may include a heating pattern (200) formed by a patterning process.

[0071] The above heating pattern (200) serves to remove ice or frost from the glass surface by inducing resistance heating according to electrical application, and the heating performance and optical characteristics can be controlled according to the method of forming and arrangement of the heating pattern (200).

[0072] A heating pattern (200) according to one embodiment of the present invention may be formed on one or both sides of a thin film glass (100), and in one embodiment, the patterning is basically applied to one side in a single-layer structure, but a double-sided structure (see FIG. 10) is also possible depending on the specific application.

[0073] A patterning process according to one embodiment of the present invention may be implemented by a physical or chemical patterning process for forming a heating pattern (200) on the surface of a thin film glass (100), or by a patterning process using a composite method that combines these. In one embodiment, the heating pattern (200) may be formed inside the surface of the thin film glass (100) by etching the surface of the thin film glass (100) by a patterning process, or the heating pattern (200) may be formed on the upper surface of the thin film glass (100) by a patterning process.

[0074] A heating pattern (200) according to one embodiment of the present invention can be performed by a photolithography process or a laser patterning process, and can be performed together with a physical or chemical thin film deposition process.

[0075] For example, in a photolithography process, a photoresist is applied to the surface of a thin film glass (100), and then an exposure and development process using a mask is performed to define a heating pattern (200) region, and a metal layer (220) is deposited on top of it (e.g., sputtering, CVD, plating process, etc.) to form a heating pattern (200) by a lift-off process.

[0076] In addition, a metal layer (220) can be first deposited on the thin film glass (100), and then a heat-generating pattern (200) region can be defined on the upper surface by a photolithography process to form a desired heat-generating pattern (200) of the metal layer (220) through an etching process, and if necessary, a more precise pattern can be formed by selectively etching the metal layer (220) by a laser patterning process.

[0077] In addition, the heating pattern (200) according to one embodiment of the present invention is not limited in shape or arrangement method, but may form a regular pattern to improve optical properties. For example, it may be a circular, elliptical, or polygonal shape such as a triangle, square, pentagon, hexagon, heptagon, or octagon, and may be a zigzag shape.

[0078] In addition, the heating pattern (200) according to one embodiment of the present invention may be of various forms such as a line type, a grid type, or a wavy type. The shape of each pattern may be determined by considering heating efficiency, current distribution, optical characteristics, etc.

[0079] Referring to FIG. 3, in the case of a line pattern, it can be seen that the heating pattern (200) is arranged in a straight line shape.

[0080] These line patterns can be effectively used mainly in large glass panels, vehicle glass, building windows, etc., and are suitable for cases where uniform heat generation over a long period of time is required. For example, the line width of the line pattern can be set to 3㎛ or more and 500㎛ or less, and the pattern spacing can be adjusted to 30㎛ or more and 2500㎛ or less to form.

[0081] The above-mentioned line pattern can maintain constant heat resistance, and since the current flow is aligned in a straight line, it can prevent localized overheating in specific areas. In addition, due to the simple pattern structure, the manufacturing process is easy, and it can be precisely formed through photolithography or laser patterning processes.

[0082] Referring to FIG. 4, in the case of a grid pattern, the heating pattern (200) can be arranged in a cross shape in vertical and horizontal directions to maintain a more uniform current distribution. Since the current flow in the grid pattern is dispersed in various directions compared to a line pattern, it can provide the effect of minimizing localized heating in specific areas.

[0083] A grid pattern according to one embodiment can have different pattern densities set in the central and edge regions and can perform the function of preventing current concentration in specific areas. The grid pattern can be applied particularly to automobile windshields, aircraft cockpit windows, high-end architectural windows, etc., and can be effective in environments where uniform heat generation is required.

[0084] In one embodiment, the wiring line width and spacing of the grid pattern can be adjusted within a range similar to that of the line pattern (line width: 3㎛ or more and 500㎛ or less, pattern spacing: 30㎛ or more and 2500㎛ or less), thereby improving heat generation performance and visibility.

[0085] In addition, the grid pattern has the effect of increasing the contact area of ​​the electrode, thereby lowering electrical resistance and improving the durability of the heating pattern (200). Furthermore, due to the grid structure, the overall heating efficiency is increased, and the temperature variation in specific areas can be minimized.

[0086] As shown in FIG. 5, in the case of a wavy pattern, the heating pattern (200) is designed in a curved shape, and the current flow can be further dispersed compared to a line pattern and a grid pattern, thereby improving heating uniformity.

[0087] A wave-shaped pattern according to one embodiment may include a curve pattern that is repeated in a first direction (first pattern (211)) and an identical or different curve pattern (second pattern (212)) arranged in a direction parallel to the first direction, and these patterns may be formed in a structure that intersects each other.

[0088] In conventional linear or grid patterns, the starburst phenomenon can occur as light reflects at specific angles, whereas wavy patterns disperse light reflection through their curved structure and can minimize reflection from external light sources in specific directions.

[0089] In addition, the wavy pattern allows for flexible adjustment of current flow, thereby preventing an increase in local power density. The wiring width and spacing of the wavy pattern can also be adjusted within a range similar to that of line and grid patterns.

[0090]

[0091] Referring to FIG. 6, a heating pattern (200) according to one embodiment of the present invention may be formed in a forward tapered shape that is approximately perpendicular to the thin film glass (100). The forward tapered shape may be, for example, a shape inclined at an angle (θ) of 20° to 85° with respect to the surface of the thin film glass (100). More preferably, it may be formed in the range of an angle (θ) of 20° to 50°, and even more preferably, in the range of an angle (θ) of 30° to 45°. That is, the heating pattern (200) according to one embodiment of the present invention may have a shape in which the width of the lower side in contact with the thin film glass (100) is wide and gradually narrows toward the top.

[0092] If the shape (200) of the heating pattern is formed as a reverse tapered shape, the adhesion between the heating pattern (200) and the thin film glass (100) may be reduced. Additionally, if the upper width of the heating pattern (100) becomes excessively wide, a short circuit or interference may occur between adjacent heating patterns (200), thereby hindering the flow of current. Furthermore, if the heating pattern (200) is formed as a reverse tapered shape, the possibility of bubble formation at the adhesive interface may increase, and there is a concern that the uniformity of the bonding part may be reduced as a result.

[0093] In order to implement a tapered shape of the heating pattern (200) according to one embodiment of the present invention, etching conditions can be adjusted during the etching process of the metal layer (220). When a wet etching process is applied, a gradually inclined surface can be formed by adjusting the etching speed of the metal layer (220) by adjusting the etching conditions (e.g., composition, concentration, temperature, etc. of the etching solution). When a dry etching process is applied, the heating pattern (200) can be formed to have a purely tapered shape by adjusting the etching conditions (e.g., ratio of reactive gas, power, pressure, etc.) using plasma or reactive ion etching (RIE).

[0094] Accordingly, the tapered shape of the heating pattern (200) according to one embodiment of the present invention improves the bonding strength between the heating pattern (200) and the thin film glass (100), increases the reliability of the electrical connection, and can increase the adhesion with the protective layer (400) and the adhesive layer (500) in the subsequent lamination process.

[0095] In this way, the heating pattern (200) according to the embodiment of the present invention can select and apply an appropriate pattern depending on the application environment, such as a line pattern, a grid pattern, and a wavy pattern.

[0096] For example, a linear pattern may be suitable for large glass panels or architectural windows due to its simple structure, which ensures consistent current flow, and ease of manufacturing. Additionally, a grid pattern can prevent overheating in specific areas by providing a uniform current distribution, making it suitable for environments requiring uniform heat dissipation, such as automobiles, aircraft cockpit windows, and windshields. Furthermore, a wavy pattern can minimize starburst phenomena and maintain optical visibility, making it suitable for displays, high-end architectural windows, or camera lenses.

[0097]

[0098] A transparent electrode layer (300) may be formed on the upper surface of a heating pattern (200) according to one embodiment of the present invention. That is, a transparent electrode layer (300) may be formed on a metal layer (220) that forms the heating pattern (200). The metal layer (220) and the transparent electrode layer (300) may be formed in the shape of the heating pattern (200), or may be formed in a structure in which the transparent electrode layer (300) completely covers the heating pattern (200) formed by the metal layer (220), that is, in a structure formed on the total surface of the thin film glass (100). By covering the metal layer (220) with the transparent electrode layer (300), there is no part of the metal layer (220) that is exposed, and thus, changes over time and corrosion caused by this can be minimized.

[0099] The metal layer (220) primarily serves to generate resistance heating and uses a material with high thermal conductivity and electrical stability. The material of the metal layer (220) generally used is not particularly limited and may include, for example, silver (Ag), gold (Au), aluminum (Al), copper (Cu), molybdenum (Mo), nickel (Ni), zinc (Zn), tungsten (W), titanium (Ti), tellurium (Te), chromium (Cr), etc., and preferably may be copper (Cu). These may be used alone or in a mixture of two or more types.

[0100] The metal layer (220) can be formed through thin film formation processes such as sputtering, electroplating, chemical vapor deposition (CVD), and physical vapor deposition (PVD). In one embodiment of the present invention, a uniform thin film can be formed by mainly applying a sputtering process. The thickness of the metal layer (220) can be adjusted between 0.1 μm and 1 μm, and if the thickness is too thin, the heat resistance value increases and efficiency may decrease, and conversely, if the thickness is too thick, local overheating may occur as excessive current flows.

[0101] According to one embodiment, a transparent electrode layer (300) may be formed on the metal layer (220). This serves to protect the metal layer (220) and lower the electrical contact resistance of the metal layer (220). The transparent electrode layer (300) is not specifically limited to a specific material, and may use a material capable of improving heat generation performance while maintaining light transmittance. For example, it may be one or more selected from the group consisting of carbon nanotubes (CNT), graphene, silver nanowires (AgNW), polypyrrole, polythiophene, polyacetylene, polyethylenedioxythiophene (PEDOT), polyaniline, indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), cadmium tin oxide (CTO), aluminum zinc oxide (AZO), gallium zinc oxide (GZO), fluorine tin oxide (FTO), and zinc oxide (ZnO), and preferably, indium zinc oxide (IZO) or indium tin oxide (ITO) may be used.

[0102] The transparent electrode layer (300) may have a height of 100 Å to 2000 Å (0.01 μm to 0.2 μm) from the upper surface of the metal, and preferably 150 Å to 1100 Å. If the transparent electrode layer (300) is too thin, the protective function against the external environment may be reduced, and conversely, if it is too thick, the optical transmittance may be reduced.

[0103] In addition, as an embodiment of the present invention, an interlayer may be applied to increase the bonding strength between the metal layer (220) and the transparent electrode layer (300), thereby further improving electrical reliability.

[0104] As such, the heating defrosting substrate according to one embodiment of the present invention may have a total light transmittance of 80% or more. Although the transmittance may decrease slightly when the transparent electrode layer (300) covers the entire area where the metal layer (heating pattern) (220) is placed, a material with excellent transmittance is applied as the transparent electrode layer (300), and as described above, the thickness of the transparent electrode layer (300) is formed in a range of 100 Å to 2000 Å from the upper surface of the metal layer (220), so that the transmittance of the metal layer (220) is not reduced to a problematic level.

[0105] Meanwhile, if the metal layer (220) forming the heating pattern (200) includes a material that reflects light in the visible light region, problems such as glare may occur due to issues with visibility that are easily visible to the human eye and high reflectivity to external light.

[0106] Accordingly, in one embodiment of the present invention, a blackening layer (240) may be further included on one or both sides of the metal layer (220) in the heating pattern (200), thereby reducing the reflectivity of the heating pattern (200) and preventing problems such as poor visibility and glare. When a blackening layer (240) is formed on one or both sides of the heating pattern (200), problems regarding poor visibility and glare inside and outside the heating film can be improved.

[0107] In addition, by forming the blackened layer (240) as described above, the problem of contact resistance occurring due to surface oxidation of the heating pattern (200) can be improved, thereby improving the reliability of the electrode.

[0108] The blackened layer (240) may be formed, for example, using a composition for forming a blackened layer, and the composition for forming a blackened layer may include one or more selected from the group consisting of manganese (Mn), cobalt (Co), nickel (Ni), iron (Fe), copper (Cu), titanium (Ti), and vanadium (V). More specifically, the blackened layer (240) may be formed by including an oxide containing the metal, and examples of oxides containing the metal include Al2O3, Fe2O3, TiO2, MnO3, Cr2O3, Cu2O, CuO, Cu2O3, ZnO, NiO, Co3O4, CoO, V2O5, VO2, etc.

[0109] The blackened layer (240) may be deposited through a deposition process such as sputtering or formed by electroplating, but is not limited thereto. According to one embodiment of the present invention, when the heating pattern (200) includes a blackened layer (240), the blackened layer (240) may have a thickness of 0.01 μm to 1 μm in order to prevent problems such as visibility and glare of the heating electrode while not reducing heating performance.

[0110]

[0111] Referring to FIGS. 7 to 9, a heating pattern (200) according to one embodiment of the present invention is divided into a plurality of independent heating regions (A, B, C, D), and the temperature of each heating region can be controlled individually. That is, current is induced to flow along the individual heating pattern (200), and each heating pattern (200) can be controlled to operate independently so that only a specific region is heated.

[0112] According to one embodiment of the present invention, the method of dividing the heating area may vary depending on the pattern shape, such as a line pattern, a grid pattern, or a wavy pattern, or the size and shape of each area may be adjusted according to the application environment. For example, in the case of a car windshield, the heating pattern (200) of the lower part and the central part where the wiper operates may be designed to be controlled independently, and in the case of a camera lens, unnecessary power consumption may be reduced by adjusting to heat only a specific area.

[0113] According to one embodiment of the present invention, each heating area includes a metal layer (220) and a transparent electrode layer (300), and a heating pattern (200) is independently formed for each heating area, and may include a bus bar and an electrode terminal that provide an individual electrical path. Through this structure, current can be selectively applied to a specific area, and energy efficiency can be increased by suppressing heat generation in unnecessary areas. In addition, through an individual temperature control function, the temperature of a specific area can be monitored in real time in conjunction with a temperature sensor and an independent power controller, and the current can be adjusted as needed.

[0114] According to one embodiment of the present invention, individual temperature control can be implemented by applying various methods, such as Pulse Width Modulation (PWM), voltage regulation, and current limiting. For example, using the PWM method allows for fine-tuning the power supply to a specific heating area to control the temperature precisely, while using the voltage regulation method allows for adjusting the amount of heat generated to set different heating performance as needed. Additionally, the independent temperature control function may include a function to remotely control the heating pattern (200) by linking with an Internet of Things (IoT)-based control system. Through this, the user can control the heating of a specific area via a mobile application or a central control system.

[0115] Specifically, the independent segmentation method of the heating pattern (200) according to one embodiment of the present invention can be configured in various ways depending on the application environment and purpose of use, and may include line pattern-based segmentation, grid pattern-based segmentation, wavy pattern-based segmentation, etc.

[0116] Referring to FIG. 7, the line-shaped pattern-based section can be formed by dividing it into sections to form heating lines, so that power is supplied independently to each section. This can be utilized to heat only specific areas in large glass surfaces, such as car windshields and railway windows.

[0117] Referring to FIG. 8, the grid pattern-based section divides the heating pattern (200) into sections so that the power flow can be individually controlled. This can be applied to large displays, industrial windows, aircraft cockpit glass, etc.

[0118] Referring to FIG. 9, the wavy pattern-based section can be divided into specific sections by applying a curved pattern to set independent heating zones. This can be applied to fields where optical properties are relatively important, such as display and camera lens surfaces.

[0119] In this way, according to one embodiment of the present invention, by dividing the heating pattern (200) into independent heating areas and controlling the temperature individually, unnecessary power waste can be prevented by adjusting the heating so that only specific areas are heated, thereby increasing energy efficiency. In addition, the heating pattern (200) according to one embodiment of the present invention can maintain a uniform temperature distribution by controlling the temperature of specific areas through a temperature sensor and an individual control system, and can prevent local overheating by maintaining temperature balance between heating patterns (200). Furthermore, the temperature of the heating pattern (200) can be adjusted to suit various application environments, such as automobile windshields, aircraft, cockpit windows, and camera lenses.

[0120]

[0121] As illustrated in FIG. 10, when a heating pattern (200) is formed on both sides of a thin film glass (100) according to one embodiment of the present invention, the temperature can be controlled individually for each side.

[0122] Since heat generation is possible from both the top and bottom sides, additional heat can be provided from the opposite side if sufficient defrosting is not achieved with heat generation from only one side. For example, in harsh low-temperature environments, it may be difficult to completely remove frost with heat generation from only one side; therefore, generating heat from the opposite side enables faster and more uniform defrosting. Furthermore, the system can be adjusted to heat only specific sides depending on the indoor-outdoor temperature difference, and in applications such as automotive windshields, the heat generation of each side can be independently adjusted according to changes in external temperature.

[0123] A heating pattern (200) according to one embodiment of the present invention includes a metal layer (220) and a transparent electrode layer (300), and each heating pattern (200) formed on each surface can receive power independently through individual electrode terminals and busbars. Each heating pattern (200) can be linked to a specific temperature sensor by including an individual circuit path, thereby enabling real-time response to temperature changes.

[0124] Individual temperature control methods can be implemented by applying various control techniques described above (e.g., PWM method, voltage or current control method, etc.). In addition, in conjunction with IoT-based remote control functions, users can activate or adjust heating of specific surfaces as needed, and this can be utilized in smart window or smart glass applications.

[0125] In addition, the amount of heat generated in a specific area can be controlled by setting the density of the heating pattern (200) on both sides of the thin film glass (100) differently. For example, the pattern density on the side that is in direct contact with the external environment can be increased, and the pattern density on the inner side can be decreased to enable efficient heat generation. Through this, heat generation performance can be improved while reducing unnecessary power consumption, and customized heating functions tailored to a specific environment can be implemented.

[0126]

[0127] As illustrated in FIG. 11, a heating pattern (200) according to one embodiment of the present invention can have its temperature distribution adjusted for each region by adjusting the density of the pattern in the central region (E) and the edge region (F). This adjustment of pattern density can improve the uniformity of the heat distribution, prevent localized overheating that may occur in specific regions, and increase energy efficiency.

[0128] The reason for adjusting the density of the heat generation pattern (200) is that the degree of heat loss differs between the central and edge regions. Generally, heat can be retained for a relatively long time in the central region, whereas heat loss can be significant in the edge region due to contact with the external environment. Therefore, in one embodiment of the present invention, the density of the heat generation pattern (200) is adjusted to control the balance of heat dissipation between the central and edge regions, thereby allowing the temperature of the glass front surface to be maintained more uniformly.

[0129] A heating pattern (200) according to one embodiment of the present invention includes a metal layer (220) and a transparent electrode layer (300) is formed on the upper surface thereof, so that the temperature distribution can be precisely controlled by adjusting the pattern density of the heating pattern (200). For example, if the pattern density of the edge area is increased, the amount of heat generated in that area increases, and if the pattern density of the central area is relatively lowered, the temperature of the central part can be stably maintained while reducing unnecessary power consumption. Through this, the heat distribution for removing frost or preventing fogging can be controlled.

[0130] Specifically, the density adjustment of the heating pattern (200) can be controlled by adjusting the line width of the heating pattern (200) to control the amount of heat generated in a specific area. For example, the current density can be increased by forming a narrow pattern line width in the edge area, and the amount of heat generated can be reduced by maintaining a relatively wide line width in the central area. Additionally, referring to FIG. 11, the density can be changed by adjusting the spacing between the heating patterns (200). The amount of heat generated can be controlled even under the same current supply conditions by narrowing the pattern spacing in the edge area and widening the pattern spacing in the central area. Furthermore, the current flow in a specific area can be adjusted by changing the arrangement of the busbar and the method of connecting the electrodes.

[0131] In addition, according to one embodiment of the present invention, the heating pattern (200) may be implemented to enable temperature control in conjunction with a temperature sensor and a control system. For example, if the temperature of the edge region decreases faster than that of the center region, the temperature sensor collects the corresponding data, and the control system can automatically supply additional current to the edge region to compensate for the temperature. This allows for responding to environmental changes in real time.

[0132]

[0133] A protective layer (400) may be included on the total surface of a thin film glass (100) that includes a heating pattern (200) according to one embodiment of the present invention.

[0134] The above protective layer (400) can be formed to cover the upper total surface of the thin film glass (100) containing the heating pattern (200), that is, the thin film glass (100) exposed between the heating pattern (200) and the heating pattern (200).

[0135] Additionally, referring to FIG. 12, when a transparent electrode layer (300) is formed on a heating pattern (200), it can be seen that a protective layer (400) is formed on the total surface of the transparent electrode layer (300).

[0136] In this case, if the transparent electrode layer (300) is formed only on the upper part of the heating pattern (200), a protective layer (400) may be formed on the total surface to cover the exposed thin film glass (100), the heating pattern (200), and the transparent electrode layer (300).

[0137] The heating pattern (200) may be subject to corrosion, contamination, scratches, etc. due to environmental factors, which may result in a decrease in heating performance. In particular, since the thin film glass (100) may have a vulnerable structure due to the characteristics of the glass material, forming a protective layer (400) can strengthen durability and maintain stable performance for a long period. Additionally, if exposed to an external environment, electrical contact failure may occur or heating efficiency may decrease due to leakage current between electrodes.

[0138] Accordingly, in one embodiment of the present invention, a protective layer (400) is formed to ensure electrical insulation of the heating pattern (200) and to prevent unnecessary contact with the outside, thereby improving electrical reliability.

[0139] Specifically, a protective layer (400) according to one embodiment of the present invention may be formed from a silica (SiO2)-based or polymer-based material. A silica-based protective layer (400) provides high hardness and chemical resistance and can be uniformly coated on the surface of a thin film glass (100) containing a heating pattern (200). This increases resistance to external impact or scratches and serves to prevent corrosion caused by environmental factors. A polymer-based protective layer (400) may be applied where flexibility is required and can provide moisture resistance and acid resistance while minimizing mechanical deformation of the heating pattern (200).

[0140] The protective layer (400) can be formed in various ways, such as using processes like sputtering, deposition, spin coating, or slurry coating. The sputtering process can form the protective layer (400) uniformly and can realize a thin film structure with high durability. The spin coating method is suitable for large-area processes while maintaining a uniform thickness and can be applied to displays and automotive glass.

[0141] Additionally, according to one embodiment of the present invention, the protective layer (400) may be formed as a single layer or a multilayer structure. In the case of a single-layer protective layer (400), it is advantageous to emphasize specific physical or chemical properties, and in the case of a multilayer protective layer (400), it can further improve durability and protect the heat generation pattern (200). For example, a silica layer having chemical resistance may be formed on the lower layer, and a coating providing water-repellent or oleophobic functions may be applied to the upper layer.

[0142] Additionally, the protective layer (400) according to one embodiment of the present invention may be formed so as not to impair the performance of the heating pattern (200). The thickness of the protective layer (400) is adjusted to maintain the efficiency of the heating pattern (200) and to ensure that heat transfer is not hindered due to excessive thickness. Generally, the thickness of the protective layer (400) may be formed within a range of tens of nanometers (nm) to several micrometers (μm), and may be adjusted considering the heating characteristics and optical characteristics.

[0143] By applying the protective layer (400) in this way, the performance of the heat pattern (200) can be prevented even during long-term use, and the heat pattern (200) can be protected from external shocks or contaminants.

[0144]

[0145] A thin film glass (100) having a heating pattern (200) formed according to one embodiment of the present invention can be bonded on both sides to an upper glass substrate (610) and a lower glass substrate (620) through an adhesive layer (500). That is, the upper glass substrate (610) and the lower glass substrate (620) are formed as the outermost layers of a heating defrosting substrate, and are bonded to each other by the thin film glass (100) and the adhesive layer (500) to form a glass-to-glass bond overall.

[0146] This can prevent the problem of haze increase that occurs in conventional methods using heating films, and can form a heating structure that is completely integrated inside the glass through glass-to-glass bonding. Through this, the adhesion between the heating pattern (200) and the glass is improved, providing uniform heat transfer, and optical properties can be improved through the adhesive layer (500). In addition, since the heating pattern (200) is protected from the external environment, long-term reliability can be maintained.

[0147] An adhesive layer (500) according to one embodiment of the present invention serves to stably bond the thin film glass (100) to an upper glass substrate (610) and a lower glass substrate (620). In one embodiment of the present invention, the selection of the adhesive layer (500) can be made by considering optical properties, thermal stability, durability, and mechanical strength beyond simple physical bonding.

[0148] An adhesive layer (500) according to one embodiment of the present invention may be any one of PVB (Polyvinyl Butyral), EVA (Ethylene Vinyl Acetate), TPU (Thermoplastic Polyurethane), Ionomer, PU (Polyurethane), and PDMS (Polydimethylsiloxane), or a mixture of two or more of these.

[0149] PVB is an adhesive layer (500) used for automobile windshields, architectural laminated glass, etc., and provides excellent transparency and impact resistance. PVB can increase the adhesion between glass while maintaining high optical transmittance, so it can be effectively used in a heat-dissipating substrate according to one embodiment of the present invention. In particular, PVB has flexibility and excellent shock-absorbing ability, and can provide a function to prevent fragments from flying when glass is broken. In addition, PVB can be modified into a functional film that blocks light of a specific wavelength, so additional ultraviolet (UV) blocking and heat blocking characteristics can be provided.

[0150] EVA is an adhesive material with excellent moisture and heat resistance, capable of maintaining stable bonding strength, particularly in high-temperature environments such as solar panels. EVA exhibits superior resistance to heat and moisture compared to PVB, and does not undergo deformation or degradation of adhesive strength even in high-temperature and high-humidity environments for extended periods. When EVA is applied to a heat-generating defrosting substrate according to one embodiment of the present invention, stable bonding strength can be maintained even under conditions where the temperature rises, thereby ensuring long-term reliability.

[0151] In addition, adhesive layer (500) materials that can be used in one embodiment of the present invention include TPU (Thermoplastic Polyurethane), Ionomer, PU (Polyurethane), PDMS (Polydimethylsiloxane), etc. TPU is a thermoplastic material that provides high elasticity and impact resistance, has high adhesive strength while maintaining optical transparency, and can be applied to automobile and aircraft windows, etc. Ionomer provides high impact resistance and chemical resistance, and has excellent transparency and durability, so it can be used in high-grade laminated glass. PU is a material with excellent durability and flexibility, provides stable adhesion even in high-temperature environments, and PDMS has high transparency and moisture resistance, so it can be used in special environments.

[0152] This adhesive layer (500) is formed on the upper and lower sides of the thin film glass (100) on which the heating pattern (200) is formed, so that the thin film glass (100) can be bonded to the upper glass substrate (610) and the lower glass substrate (620). The method of forming the adhesive layer may be carried out by a film lamination method or a solution coating method.

[0153] The above film lamination method is such that the adhesive layer (500) is provided in the form of a pre-manufactured film and is laminated together with the thin film glass (100) and the upper and lower glass substrates (610, 620). For example, a thermoplastic adhesive layer such as PVB (Polyvinyl Butyral) and EVA (Ethylene Vinyl Acetate) can be provided in the form of a film and laminated.

[0154] The above solution coating method is formed by applying an adhesive layer (500) in a liquid form and then drying and curing it. An adhesive layer (500) of the TPU (Thermoplastic Polyurethane) and PU (Polyurethane) series can be uniformly coated on the surface of a thin film glass (100) in a solution form and then cured through a subsequent process.

[0155] The bonding method using this adhesive layer (500) may vary depending on the characteristics of the adhesive used, and generally, heat lamination, vacuum lamination, or UV curing methods may be applied.

[0156] In the case of heat lamination, adhesive layers containing PVB and EVA possess thermoplastic properties, allowing for bonding by applying pressure at high temperatures to enhance adhesion and prevent bubble formation. Vacuum lamination is similar to heat lamination, but it prevents internal bubble formation by creating a vacuum during the bonding process. UV curing can be applied to TPU and PU-based adhesive layers, enabling bonding as the adhesive layer cures rapidly after UV irradiation.

[0157] As such, the adhesive layer (500) according to one embodiment of the present invention can go beyond simple glass-to-glass bonding and improve resistance to thermal shock while maintaining the optical properties of the heating pattern (200) and the glass structure. That is, it can provide uniform bonding between the glasses and relieve thermal or mechanical stress, thereby increasing the durability of the heating defrosting substrate.

[0158]

[0159] Referring to FIG. 13, an adhesive layer (500) according to one embodiment of the present invention is formed as a multilayer structure (510, 520, 530), and the adhesive layer (500) adjacent to the thin film glass (100) may be formed of a material having higher resistance to thermal shock.

[0160] This multilayer adhesive layer (500) may be formed on the upper or lower side of the thin film glass (100), or on both the upper and lower sides. This multilayer adhesive layer (500) structure can serve to prevent physical damage and ensure long-term durability when the thin film glass (100) to which the heating pattern (200) is applied undergoes a rapid temperature change due to heat. In the embodiment of FIG. 13, the multilayer adhesive layer (500) structure is shown formed on the lower side of the thin film glass (100).

[0161] An adhesive layer (500) according to one embodiment of the present invention may be composed of at least two layers, each layer having specific physical or chemical properties. The most basic structure may include a primary adhesive layer (510) that is directly adhered to a thin film glass (100) and a secondary adhesive layer (520) that reinforces it, and a structure including a tertiary adhesive layer (530) or more may also be applied as needed.

[0162] According to one embodiment of the present invention, a primary adhesive layer (510) adjacent to a thin film glass (100) may have high heat resistance and impact resistance. This is because when a heating pattern (200) is heated by an electric current supply, the layer in direct contact with the surface of the thin film glass (100) must withstand rapid temperature changes. Materials with such heat resistance may include specially modified PVB (Polyvinyl Butyral), heat-resistant EVA (Ethylene Vinyl Acetate), TPU (Thermoplastic Polyurethane), and Ionomer. These materials have a high coefficient of thermal expansion and possess the characteristic of maintaining stable adhesion without physical deformation within a specific temperature range.

[0163] Additionally, the secondary and tertiary adhesive layers (520, 530) can improve flexibility and relieve stress that may occur due to thermal shock. Since the heating defrosting substrate may be exposed to an environment of rapid temperature changes, if the adhesive layer (500) is composed of a single material, cracking or delamination may occur in the adhesive layer (500) due to the difference between physical expansion and contraction. Therefore, the secondary adhesive layer (520) can be formed with a structure that absorbs thermal shock, and a polymer material having viscoelastic properties can be used as a representative example. For example, TPU, PDMS (Polydimethylsiloxane), modified PU (Polyurethane), etc., can be used.

[0164] As such, according to one embodiment of the present invention, a single layer or multilayer adhesive layer (500) can improve the durability of the heating pattern (200) and strengthen the bonding strength between the thin film glass (100), the upper glass substrate (610), and the lower glass substrate (620). This can improve long-term reliability.

[0165] In particular, the primary adhesive layer (510) adjacent to the thin film glass (100) is composed of a material that emphasizes heat resistance to prevent physical deformation caused by thermal shock, and the secondary and tertiary adhesive layers (520, 530) can further enhance structural stability by reinforcing shock absorption and flexibility.

[0166]

[0167] In addition, according to one embodiment of the present invention, the adhesive layer (500) may include a functional coating material to selectively transmit or block light of a specific wavelength.

[0168] Here, the functional coating material can play a role in controlling specific wavelengths among ultraviolet (UV), infrared (IR), and visible light (VIS). If a coating material having an ultraviolet blocking function is included, it can block ultraviolet rays entering from external sunlight, thereby improving the long-term reliability of the thin film glass (100) and the heating pattern (200). In particular, if an ultraviolet absorber is added to the adhesive layer (500) based on PVB (Polyvinyl Butyral) or EVA (Ethylene Vinyl Acetate), it can prevent the heating pattern (200) from deteriorating or oxidizing due to ultraviolet rays and strengthen durability.

[0169] When a coating material having an infrared (IR) blocking function is included, the temperature of the heat-generating defrosting substrate can be controlled by controlling excessive heat generated by sunlight. The infrared blocking coating material can be classified into reflective or absorbent types. A reflective (IR Reflective) coating can reduce heat inflow into the glass by reflecting specific infrared wavelengths, while an absorbent (IR Absorptive) coating can regulate the thermal balance with the heat-generating pattern (200) by absorbing infrared rays. This technology enhances energy saving effects and can be applied to smart windows and high-efficiency glass products.

[0170] Functional coating materials that control visible light (VIS) transmittance can improve visibility in specific environments. For example, in cases where diffuse reflection at specific angles needs to be reduced, such as in automotive windshields or aircraft windows, a functional coating layer can be applied to minimize glare. Additionally, in environments where displays and Head-Up Displays (HUDs) are applied, visibility can be enhanced by controlling the transmittance of specific colors.

[0171] Such functional coating materials may be used mixed within the adhesive layer (500), or may be deposited as a separate coating layer on the surface of the adhesive layer (500) or laminated in the form of a thin film.

[0172] In addition, the functional coating material can also be applied to the multilayer adhesive layer (500) and can perform multiple functions in combination with the multilayer adhesive layer (500). For example, if the primary adhesive layer (510) includes a UV blocking function and the secondary adhesive layer (520) includes an infrared reflection function, it is possible to block UV rays entering from external sunlight while improving heat shielding performance. In addition, by combining high refractive index and low refractive index functional coating materials, specific optical reflection characteristics can be controlled, so it can be applied to advanced smart windows and transparent displays.

[0173]

[0174] As illustrated in FIG. 14, according to one embodiment of the present invention, a low-reflection coating layer (700) may be formed on one or both sides of one or more of the upper glass substrate (610) and the lower glass substrate (620).

[0175] According to one embodiment of the present invention, the upper glass substrate (610) and the lower glass substrate (620) may be formed of tempered glass. Tempered glass is capable of maintaining structural stability even under physical impact or rapid temperature changes, and when the thin film glass (100) with the heat-generating pattern (200) is heated, a temperature change occurs on the glass surface, so high heat resistance is required to withstand this.

[0176] Tempered glass ensures impact resistance through surface compressive stress and provides safety by breaking into small particles upon breakage. While ordinary glass can generate sharp fragments upon breaking that pose a risk to the human body, tempered glass possesses safety breakage characteristics, allowing it to shatter into relatively small particles upon breakage, thereby minimizing secondary damage. These characteristics are essential requirements for automobiles, aircraft, and architectural glass, and by applying tempered glass to the heat defrosting substrate according to one embodiment of the present invention, durability and safety can be enhanced.

[0177] According to one embodiment of the present invention, a low-reflection coating layer (700) may be formed on one or both sides of one or more of the upper glass substrate and the lower glass substrate to improve optical properties.

[0178] The anti-reflection coating layer (AR Coating) (700) can reduce diffuse reflection and light loss occurring on the glass surface, thereby improving visibility and increasing energy efficiency. Ordinary glass can reflect about 8-10% of visible light, which can obstruct the view, but by applying the anti-reflection coating layer (700), the reflectivity can be reduced to 1% or less.

[0179] In addition, the low-reflection coating layer (700) according to one embodiment of the present invention may be formed as a single layer or a multilayer. A single-layer structure is advantageous for reducing the reflectance of a specific wavelength, while a multilayer structure can provide low-reflection characteristics over a wide range of wavelengths.

[0180] In addition, the anti-reflection coating layer (700) can enhance the scratch-resistant function of the glass surface and may also add anti-smudge and hydrophobic functions. Through this, the heat-generating defrosting substrate according to one embodiment of the present invention can provide long-term stable optical performance while maintaining durability.

[0181] In one embodiment, the low-reflection coating layer (700) may be formed in a multilayer structure and may be formed by alternately depositing thin films with different refractive indices. For example, the low-reflection coating layer (700) in a multilayer structure may be formed using transparent inorganic thin films such as SiO2, TiO2, or MgF2.

[0182] Accordingly, the low-reflection coating layer (700) in the heat-generating defrosting substrate according to one embodiment of the present invention can be utilized in various applications such as displays, camera lenses, and smart windows by reducing light reflection on the glass surface. For example, in the case of a car windshield, sunlight reflection is reduced, making it easier for the driver to secure a clear view, and in aircraft windows, the clarity of the external scenery can be enhanced. In addition, in smart windows and transparent displays, unnecessary reflection can be suppressed while maintaining high clarity characteristics.

[0183]

[0184] As such, a heating defrosting substrate according to one embodiment of the present invention comprises a thin film glass (100), a heating pattern (200), an adhesive layer (500), an upper glass substrate (610), and a lower glass substrate (620), and can generate heat to remove frost and prevent fogging. That is, it can provide heating performance while maintaining optical transmittance and can be applied to various application fields such as automobiles, railways, architecture, and camera lenses.

[0185]

[0186] FIG. 15 is a flowchart illustrating a method for manufacturing a heat-generating defrosting substrate according to an embodiment of the present invention. Descriptions of components duplicated in the above-described embodiments are to be omitted or briefly described in this embodiment.

[0187] As described above, a method for manufacturing a heat-generating defrosting substrate according to one embodiment of the present invention may include the steps of preparing at least one thin film glass (S810), forming a heat-generating pattern on at least one surface of the thin film glass using a patterning process (S820), and bonding the thin film glass to an upper glass substrate and a lower glass substrate on both sides through an adhesive layer (S830).

[0188] First, a method for manufacturing a heating defrosting substrate according to one embodiment of the present invention prepares a thin film glass (S810). The thin film glass has a thickness in the range of 0.2 mm or more and 1 mm or less, and may be made of soda-lime glass, borosilicate glass, aluminosilicate glass, etc.

[0189] Then, a heating pattern is formed on at least one surface of the thin film glass using a patterning process (S820). The heating pattern serves to provide uniform heating when current is applied, and the formation of such a heating pattern can be achieved by a photolithography process or a laser patterning process.

[0190] The above heating pattern includes a metal layer and may include metals such as copper (Cu), silver (Ag), indium (In), and molybdenum (Mo). A transparent electrode layer is formed on the upper surface of the metal layer (220) and may include indium tin oxide (ITO), indium zinc oxide (IZO), etc., and is formed to maintain visible light transmittance while increasing heating efficiency.

[0191] The shape of the above heating pattern can be formed into a structure such as a line pattern, a grid pattern, or a wavy pattern, and different pattern densities may be applied to the central area and the edge area to increase heating uniformity.

[0192] Then, the thin film glass with the heat generation pattern formed thereon is bonded to the upper glass substrate and the lower glass substrate on both sides through an adhesive layer (S830). The adhesive layer can be formed from materials such as PVB (Polyvinyl Butyral) or EVA (Ethylene Vinyl Acetate), and may be formed in a multilayer structure as needed. When applying a multilayer adhesive layer, the reliability can be improved by using a material with higher resistance to thermal shock in the layer adjacent to the thin film glass.

[0193] In addition, the adhesive layer may include a functional coating material that selectively transmits or blocks light of specific wavelengths, thereby enabling functions such as solar energy control, UV blocking, and infrared reflection.

[0194] According to one embodiment of the present invention, when the thin film glass is bonded to an upper glass substrate and a lower glass substrate through an adhesive layer, a vacuum environment is applied to prevent the generation of bubbles at the adhesive layer and the adhesive interface. This is intended to minimize defects that may occur during the bonding process and to ensure excellent optical transmittance and structural stability.

[0195] According to one embodiment of the present invention, in a process of bonding a thin film glass, an upper glass substrate, and a lower glass, the glass layers are bonded by heating and curing the adhesive layer using heat or pressure. During this process, fine air bubbles may be present within the adhesive layer or at the glass-adhesive layer interface. These bubbles can reduce optical transmittance, weaken mechanical bonding strength over the long term, and hinder uniform heat transfer of the heat generation pattern. Therefore, in one embodiment of the present invention, a vacuum environment is applied to fundamentally prevent the generation of bubbles within the bonding layer and ensure bonding quality.

[0196] A vacuum lamination process can be used as a method to perform bonding in a vacuum environment. In this process, a thin film glass, an adhesive layer, an upper glass substrate, and a lower glass substrate are laminated, and then bonding is performed by applying heat and pressure while the pressure is lowered inside a vacuum chamber. Since air and moisture within the adhesive layer are expelled in a vacuum state, bubble formation is suppressed and the bonding interface can be formed more uniformly.

[0197] Specifically, a heat-generating defrosting substrate structure laminated between glass layers including an adhesive layer is prepared, and the laminated structure is moved into a vacuum chamber and the internal air is removed by lowering the pressure to a certain level. It is heated to a constant temperature under vacuum conditions to ensure that the adhesive layer fuses uniformly with the glass, and then the bonding is completed while adjusting the pressure. For example, 10 -3 Bonding can be performed in a low vacuum environment of Torr or less, and heating can be carried out in a temperature range of 80°C to 150°C depending on the type of adhesive layer. As for the pressurization method, a membrane press or roller press method that provides uniform pressure can be used, thereby allowing uniform pressure to be applied across the entire bonding layer.

[0198] In addition, a primary bond can be performed by placing a heat-generating defrosting substrate structure, which is laminated between glass layers including an adhesive layer, into a vacuum bag to lower the pressure to a certain level and raise the temperature, or by using a hot roll to raise the temperature and remove air. After the primary bond, a secondary bond can be performed in an autoclave by applying pressure and raising the temperature.

[0199] Here, the first bonding can be performed within 1 hour at a temperature of 300 Torr to 700 Torr and room temperature to 100°C, depending on the type of adhesive layer. The second bonding can be performed approximately 10 depending on the type of adhesive layer. 5It can be performed at a pressure of Torr or higher at a temperature of about 130°C to 150°C for 1 to 3 hours, and preferably, after secondary bonding for 2 hours, it can be slowly cooled.

[0200] Bonding in a vacuum environment can also improve the transparency of the adhesive layer. In conventional bonding processes, the presence of residual air can cause light scattering within the adhesive layer, leading to a decrease in optical transmittance. In contrast, completely removing residual air through vacuum bonding allows the light path to maintain greater straightness, thereby preserving high transparency.

[0201] In addition, the vacuum bonding process serves to increase the adhesion between the heating pattern and the adhesive layer. The heating pattern is formed through fine patterning on a thin film glass, and if adhesion with the adhesive layer is not ensured, the heat transfer efficiency may decrease. When bonding is performed in a vacuum environment, the adhesive layer adheres more closely to the heating pattern, allowing for a uniform heat distribution and maintaining a stable structure even against thermal or mechanical shock.

[0202]

[0203] The present invention will be explained in more detail below using examples and comparative examples. However, the following examples are intended to illustrate the present invention, and the present invention is not limited by the following examples and may be modified and changed in various ways.

[0204]

[0205] Examples and Comparative Examples: Manufacturing of Heating and Defrosting Substrates

[0206] Example 1: Heating defrosting substrate including a thin-film glass-type heating pattern

[0207] After preparing a thin film glass with a thickness of 0.25 mm and a size of 150 mm x 150 mm, a copper II oxide (CuO) layer with a thickness of 600 Å (0.06 μm) was formed on the thin film glass using a sputtering process to produce a blackened layer. A copper layer (Cu) with a thickness of 6000 Å (0.6 μm) was deposited on the blackened layer by performing a sputtering process to form the basic structure of a heating pattern. Subsequently, a copper II oxide (CuO) layer with a thickness of 600 Å (0.06 μm) was formed again on the copper layer (Cu).

[0208] Subsequently, a photolithography process was performed on the laminate composed of the blackened layer and the metal layer to define the region of the heat generation pattern, and a heat generation pattern was formed through an etching process. The line width of the heat generation pattern is 4.5 μm, the thickness is 0.72 μm (7200 Å), and the spacing between patterns is 465 μm. The shape of the heat generation pattern was implemented as a wave-shaped pattern.

[0209] Using PVB, the thin film glass containing the above heating pattern was bonded to both sides with an upper glass substrate and a lower glass substrate. Finally, a heating defrosting substrate was completed in which the thin film glass containing the heating pattern was stably bonded in a glass-to-glass structure.

[0210] Accordingly, the final structure of Example 1 provides a heating defrosting substrate comprising a lower glass substrate / PVB (adhesive layer) / thin film glass (thickness approximately 0.25 mm) / CuO (blackened layer) / Cu (heating pattern, metal layer) / CuO (blackened layer) / PVB (adhesive layer) / upper glass substrate.

[0211]

[0212] Comparative Example 1: Heating defrosting substrate including a film-type heating pattern

[0213] After sequentially forming a separation layer and a protective layer on a temporary substrate (e.g., glass) of 150 mm x 150 mm, a copper oxide (CuO) layer with a thickness of 600 Å (0.06 μm) was formed using a sputtering process to produce a blackened layer. A copper layer (Cu) with a thickness of 6000 Å (0.6 μm) was deposited on the blackened layer by performing a sputtering process, and a copper oxide (CuO) layer with a thickness of 600 Å (0.06 μm) was formed again on the copper layer (Cu) to complete a laminate consisting of a metal layer and a blackened layer.

[0214] A photolithography process was performed on the above laminate to define the region of the heat generation pattern, and an etching process was performed to form the heat generation pattern. The line width of the heat generation pattern is 4.5 μm, the thickness is 0.72 μm (7200 Å), and the spacing between patterns is 465 μm. The shape of the heat generation pattern was implemented as a wavy pattern.

[0215] Subsequently, a primary transfer of the heating pattern was performed using a temporary support (e.g., PF (Polymide)), the transferred heating pattern was placed on a PET film coated with adhesive, and laminated through a roll lamination process. After lamination, the heating pattern was stably transferred onto the PET film by curing the PVB using a UV curing machine.

[0216] A PET film having a heating pattern formed by this method is bonded to both sides with a lower glass substrate and an upper glass substrate through an adhesive layer made of PVB. As a result, a heating defrosting substrate comprising a lower glass substrate / PVB (adhesive layer) / PET film / adhesive / protective layer / CuO (blackening layer) / Cu (heating pattern, metal layer) / CuO (blackening layer) / PVB (adhesive layer) / upper glass substrate is provided.

[0217]

[0218] Experimental Example

[0219] Measurement of light transmittance and haze characteristics

[0220] Light transmittance and haze characteristics were evaluated for the heating defrosting substrates of Example 1 and Comparative Example 1. Light transmittance was measured according to ASTM E903 standards using a UV-VIS spectrophotometer (UV-Visible Spectrophotometer, Shimadzu UV-2600, etc.), and haze was measured according to ASTM D1003 standards using a haze meter (Haze Meter, Murakami HM-150N, etc.).

[0221]

[0222] Example 1 Comparative Example 1 Transmittance (Before PVB Bonding) (%) 88.5 88.1 Transmittance (After PVB Bonding) (%) 88.5 88.1 Haze (Before PVB Bonding) 0.9 1.0 Haze (After PVB Bonding) 0.9 1.81

[0223] As shown in Table 1 above, the heating defrosting substrate including a thin-film glass type heating pattern according to Example 1 had a transmittance of 88.5% before bonding and remained constant at 88.5% even after bonding by PVB. The haze value was 0.9 before bonding by PVB and remained constant at 0.9 even after bonding. This is expected to be because the increase in light scattering at the interface with the adhesive layer can be prevented by forming a heating pattern on the thin-film glass.

[0224] On the other hand, when a PET film was used in Comparative Example 1, the transmittance before bonding with PVB was 88.1% and remained at the same level after bonding, but the haze value increased from 1.0 before bonding with PVB to 1.81 after bonding.

[0225] The cause of this increase in haze is analyzed to be due to increased surface roughness and the formation of internal microbubbles during the bonding process between the PET film containing a heat-generating pattern, the adhesive layer, and the upper and lower glass substrates. The PET film has a somewhat non-uniform surface compared to thin-film glass, and there is a high possibility of deformation occurring when bonded with the adhesive layer. As a result, it is expected that light scattering increases at the interface between the adhesive layer and the PET film, leading to an increase in the haze value.

[0226] In addition, when a PET film undergoes a heating or lamination process in a high-temperature environment, unreacted oligomer components contained within it may migrate to the surface and reach the interface between the heating pattern and the adhesive layer, or between the adhesive layer and the glass substrate. These migrated oligomers can alter the roughness of the interface or increase light scattering. This leads to reduced visibility, particularly in heating substrates with high transmittance, and can act as one of the main causes of increased haze.

[0227]

[0228] As such, the thin film glass type bonding method according to Example 1 can suppress the increase in haze while maintaining a high transmittance compared to the bonding method of Comparative Example 1, which uses a film containing a heating pattern. In particular, in the method using the PET film of Comparative Example 1, the haze value increases to 1.81 after bonding, whereas in the method applying the thin film glass with a heating pattern formed in Example 1, the haze value is maintained at a constant 0.9.

[0229] Therefore, by applying the thin-film glass bonding method according to one embodiment of the present invention, light scattering can be reduced while maintaining high optical transmittance, so it can be widely used in applications where transmittance and visibility are important, such as automotive glass, smart windows, and aircraft canopies.

Claims

It comprises at least one thin film glass, and At least one side of the thin film glass includes a heating pattern formed by a patterning process, and The above thin film glass is, A heating defrosting substrate bonded to both sides with an upper glass substrate and a lower glass substrate. In paragraph 1, The above thin film glass is, A heat-generating defrosting substrate formed with a thickness of 0.2 mm or more and 1 mm or less. In paragraph 1, On the upper part of the above heating pattern, A heating defrosting substrate with a transparent electrode layer formed thereon. In paragraph 1, The above heating pattern is, A heat-generating defrosting substrate comprising any one of a line pattern, a grid pattern, and a wave pattern. In paragraph 1, The above heating pattern is, A heating defrosting substrate divided into multiple independent heating zones, each heating zone capable of individually controlling the temperature. In paragraph 1, When a heating pattern is formed on both sides of the above thin film glass, A heating defrosting substrate capable of individually controlling the temperature for each side. In paragraph 1, The above heating pattern is, A heating defrosting substrate that controls temperature distribution by adjusting the density of patterns in the central and edge regions. In paragraph 1, A heat-dissipating substrate comprising a protective layer on the total surface of a thin film glass having the above-mentioned heat-generating pattern. In paragraph 1, The above double-sided bonding is achieved by an adhesive layer, and The above adhesive layer is, A heat-generating defrosting substrate formed with a multilayer structure, wherein the adhesive layer adjacent to the thin film glass has higher resistance to thermal shock. In paragraph 1, The above double-sided bonding is achieved by an adhesive layer, and The above adhesive layer is, A heating defrosting substrate containing a functional coating material to selectively transmit or block light of a specific wavelength. In Article 9 or Article 10, The above adhesive layer is, A heating defrosting substrate using any one of PVB (Polyvinyl Butyral), EVA (Ethylene Vinyl Acetate), TPU (Thermoplastic Polyurethane), Ionomer, PU (Polyurethane), and PDMS (Polydimethylsiloxane), or a mixture of two or more of these. In paragraph 1, On one or both sides of any one or more of the upper glass substrate and the lower glass substrate, A heat-generating defrosting substrate with an anti-reflective coating layer. A step of preparing at least one thin film glass; A step of forming a heating pattern on at least one surface of the thin film glass using a patterning process; A method for manufacturing a heat-generating defrosting substrate comprising the step of bonding the above thin film glass to both sides with an upper glass substrate and a lower glass substrate. In Paragraph 13, The step of forming the above-mentioned heating pattern is, A method for manufacturing a heat-generating substrate that forms the heat generation pattern by a photolithography process or a laser patterning process. In Paragraph 13, The step of forming the above-mentioned heating pattern is, A method for manufacturing a heat-generating defrosting substrate comprising the steps of forming a metal layer on the thin film glass, performing a patterning process on the metal layer, and forming a transparent electrode on the metal layer. In Paragraph 13, After the step of forming the above heating pattern, A method for manufacturing a heat dissipation substrate comprising the step of additionally forming a protective layer on the total surface of a thin film glass containing the above-mentioned heat dissipation pattern.

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