Transparent antenna film

Abstract

This application relates to a transparent antenna film with improved pattern opacity.

Description

Technical Field

[0001] [Cross - reference to Related Applications] This application claims the benefit of priority based on Korean Patent Application No. 10 - 2024 - 0070942 filed on May 30, 2024, and all the contents disclosed in the literature of the Korean patent application are incorporated herein by reference.

[0002] This application relates to a transparent antenna film. Specifically, this application relates to a transparent antenna film with improved invisibility of patterns.

Background Art

[0003] A film - type antenna is generally configured such that a transparent antenna having one or more mesh patterns is mounted on a transparent substrate. At this time, the transparent antenna is divided into a region where an antenna wiring pattern is formed and a region where no antenna wiring pattern is formed (a dummy region). At this time, the dummy region is formed by separating a part of an electrically conductive line forming a mesh pattern, and is an electrically insulated region.

[0004] There is a difference in aperture ratio between the separated pattern region and the (non - separated) antenna wiring pattern region. Specifically, the aperture ratio of the non - separated region is lower than that of the region having a separation part. Due to such a difference in aperture ratio, there is a problem that a mesh pattern (e.g., an antenna wiring pattern) is visually recognized by a user, which is not suitable for transparent film applications.

[0005] In consideration of such problems, technologies have been developed to make the wiring pattern invisible.

Summary of the Invention

Problems to be Solved by the Invention

[0006] An object of this application is to provide a transparent antenna film.

[0007] Another object of this application is to provide a transparent antenna film with improved pattern opacity.

[0008] The above-mentioned and other objectives of this application can all be resolved by this application, which is described in detail below. [Means for solving the problem]

[0009] According to a specific example of this application, a transparent antenna film and a method for manufacturing the same are provided.

[0010] The transparent antenna film provided in this application not only solves the aforementioned problems but also offers optical properties (e.g., transparency) and electrical conductivity at a level equivalent to or better than conventional products.

[0011] The present invention will be described in more detail below.

[0012] Transparent antenna film

[0013] In one example relating to this application, the application relates to a transparent antenna film. The transparent antenna film may include a substrate layer (A) and a pattern (or pattern layer) (B) formed on the substrate layer. In this case, "transparent" may mean that the light transmittance for light in the wavelength range of approximately 380 to 780 nm is 75% or more, or 80% or more.

[0014] The type of the substrate layer (A) is not particularly limited. Any film that can ensure the transparency required in this application can be used as the substrate layer without restriction, and examples of such films include glass and plastic. Specifically, plastics such as PET (Polyethylene terephthalate), PVB (polyvinylbutyral), PEN (polyethylene naphthalate), PES (polyethersulfon), PC (polycarbonate), polyolefin, or polyimide can be used.

[0015] Although not particularly limited, the lower limit of the thickness of the substrate layer can be, for example, 50 μm or more, 100 μm or more, 150 μm or more, 200 μm or more, 250 μm or more, 300 μm or more, 350 μm or more, 400 μm or more, 450 μm or more, or 500 μm or more. The upper limit can be, for example, 1000 μm or less, 900 μm or less, 800 μm or less, 700 μm or less, 600 μm or less, or 500 μm or less. The specific thickness of the substrate layer can be adjusted to a level that does not hinder the ensuring of durability and transparency of the transparent antenna film.

[0016] According to this application, the pattern (B) formed on the substrate layer may include at least two electrically isolated regions. Specifically, the antenna film of this application may comprise a substrate layer, an electrically conductive mesh pattern region (or antenna wiring pattern region) (b1) located on the substrate layer, and a dummy pattern region (or dummy wiring pattern region) (b2) located on the substrate layer, in which a portion of the electrically conductive lines forming a unit pattern is separated and electrically isolated from the electrically conductive mesh pattern region.

[0017] As described later, the pattern can be formed using a pattern layer having embossed and indented portions. In this case, the indented portions have a shape corresponding to (or matching) the mesh pattern of the mesh pattern layer, and the indented portions can be filled with a conductive (e.g., metal-containing) filler to a predetermined height. As a result, electrically conductive lines containing metal are formed within the indented portions, and an electrically conductive mesh pattern can be formed with these conductive lines intersecting each other.

[0018] The dummy pattern can be formed, for example, if a unit pattern exists in the overall mesh pattern, by first creating an indented portion on a part of the indented portion (corresponding to a conductive line) that forms the unit pattern, thereby interrupting the indented portion, and then filling it with a filler. Since the indented portion is filled with a filler to form a conductive line, and the indented portion that interrupts the indented portion is not filled with a conductive filler, a dummy pattern region in which a part of the electrically conductive line is separated can be formed through the above method.

[0019] The method by which the conductive filler is filled into the engraved portion is not particularly limited, and a known method can be appropriately selected to fill the engraved portion with the filler.

[0020] The cross-sectional shape of the incised portion filled with conductive filler is not particularly limited. For example, the cross-section of the incised portion of the mesh pattern layer can be an arc shape convex in the direction of the substrate layer or a rectangular cross-section including one or more interior angles. In this case, the interior angle means that two or more straight lines are connected to form a predetermined angle in the cross-section of the incised portion. For example, if there is one interior angle, the cross-section of the incised portion can be a triangular cross-section, and if there are two interior angles, the cross-section of the incised portion can be a square cross-section. In the specific example of this application, the recess can have a square cross-sectional (concave) shape.

[0021] The type of metal contained in the intaglio filler is not particularly limited. For example, the metal may include one or more selected from the group consisting of silver (Ag); gold (Au); copper (Cu); aluminum (Al); platinum (Pt); nickel (Ni); tin (Sn); molybdenum (Mo); palladium (Pd); neodymium (Nd); and alloys composed of two or more of the above metals.

[0022] In one example, the electrically conductive filler contained in (or filled into) the intaglio may further include a blackening agent. The blackening agent can suppress the starburst phenomenon and reduce the inconvenience visually felt by the user. As the blackening agent, for example, carbon black can be used. In the prior art, mainly a blackening method using a metal material was used, but it was not sufficient to achieve black (for example, in the case of Cu, it is visually recognized as dark brown). However, carbon black is advantageous for ensuring visibility as a material closer to actual black.

[0023] In a specific example of the present application, the filling of the intaglio with the filler can be performed two or more times with fillers having different components from each other. Thereby, two or more regions (layers) containing different components from each other can be filled (included) in the intaglio in sequence. That is, the electrically conductive line formed in the intaglio can have a structure in which two or more regions with different components are laminated.

[0024] For example, after filling the etched portion with the first filler containing a blackening material, filling of the etched portion with the second filler containing a metal can be performed. In such a case, the etched portion can be filled (included) with a first region (blackening material region) having a predetermined height and containing a blackening material, and a second region (metal region) formed on the first region, having a predetermined height, and containing a metal. At this time, since each filler is filled in order in the vertical direction within the etched portion, the first region and the second region can also be called the first layer (blackening material layer) and the second layer (metal layer), respectively. In such a case, considering structural stability, optical characteristics, surface resistance, etc., the height of the first region can be formed to be 0.5 μm or more, and the height of the second region can be formed to be 3.5 μm or more.

[0025] In another example, filling with a third filler containing a blackening material can be further performed after filling with the second filler. Thereby, the etched portion can be filled (included) with a first region (blackening material region) having a predetermined height and containing a blackening material, a second region (metal region) formed on the first region, having a predetermined height, and containing a metal, and a third region (blackening material region) formed on the second region, having a predetermined height, and containing a blackening material. At this time, since each filler is filled in order in the vertical direction within the etched portion, the first region, the second region, and the third region can also be called the first layer (blackening material layer), the second layer (metal layer), and the third layer (blackening material layer), respectively. In such a case, considering structural stability, optical characteristics, surface resistance, etc., the height of the first region can be formed to be 0.5 μm or more, the height of the second region can be formed to be 3.5 μm or more, and the height of the third region can be formed to be 0.5 μm or more.

[0026] In one example, the first filler, the second filler, and the third filler filled in the etched portion can further contain a binder (in addition to the blackening material and the metal). The binder fixes the materials contained in each region and imparts structural stability. The type and relative content (with respect to the blackening material and the metal) of such a binder can be adjusted at a level that does not control the optical characteristics of the antenna to be achieved in this application.

[0027] According to a specific example of this application, the transparent antenna film can satisfy the following relational expression 1.

[0028] [Relationship 1] 80% ≤ {(total pattern length of dummy pattern area) / (total pattern length of electrically conductive mesh area)} × 100 ≤ 120%

[0029] In this case, the dummy pattern region and the electrically conductive mesh pattern region that satisfy relation 1 can be any region arbitrarily selected within a size of 5 mm wide x 5 mm high (e.g., any arbitrarily selected rectangular region). The total length of each pattern can then be calculated based on an image of the pattern taken with an optical microscope, as will be described later.

[0030] As can be confirmed through the following experiment, the visibility of the pattern can be improved if the above relation 1 is satisfied. In other words, the visibility of the pattern can be improved through a design that satisfies relation 1.

[0031] In one example, the lower limit of relation 1 can be 85% or more, 90% or more, 95% or more, or 100% or more. The upper limit of relation 1 can be, for example, 115% or less, 110% or less, or 105% or less.

[0032] The upper and lower limits of the relational expression can be adjusted by the shape, line width, and / or aperture ratio of each region pattern. In other words, optimal visibility can be ensured by adjusting the shape, line width, aperture ratio, and pattern length of each region pattern.

[0033] According to a specific example of this application, the transparent antenna film can satisfy the following relational expression 2.

[0034] [Relationship 2] |Aperture ratio of electrically conductive mesh pattern area - Aperture ratio of dummy pattern area| ≤ 2%

[0035] At this time, the aperture ratio of each pattern can be calculated based on the image of the pattern taken with an optical microscope, as will be described later.

[0036] As can be confirmed through the following experiment, the visibility of the pattern can be improved if relation 2 is satisfied. In other words, the visibility of the pattern can be improved by designing it to satisfy relation 2.

[0037] In one example, the lower limit of relation 2 can be 0.5% or more, 1.0% or more, or 1.5% or more. Its upper limit can be, for example, 1.5% or less, 1.0% or less, or 0.5% or less.

[0038] The upper and lower limits of the binary relation can be adjusted by the shape, line width, and / or (total) length of each region pattern. In other words, optimal visibility can be ensured by adjusting the shape, line width, aperture ratio, and pattern length of each region pattern.

[0039] In relation to the relationships 1 and 2 described above, when the pattern pitch of the dummy region is formed relatively narrowly, the total length of the pattern can increase while the number of unit patterns within the dummy region increases. If this tendency increases excessively, the aperture ratio of the dummy region decreases significantly, resulting in the dummy region being strongly visible. Conversely, in the opposite case, either the dummy region or the conductive pattern region will be strongly visible. Therefore, as explained in relation to relationships 1 and 2, it is necessary to appropriately design the pitch size between regions, the total length of the pattern, and the aperture ratio (considering line width).

[0040] In one example, the transparent antenna film can satisfy all of the above relational expressions 1 and 2. According to a specific example of this application, a film that satisfies all of the above relational expressions 1 and 2 can have a lower limit of more than 100% in relation to relational expression 1, specifically 101% or more, 102% or more, 103% or more, 104% or more, 105% or more, 106% or more, 107% or more, 108% or more, 109% or more, or 110% or more. Furthermore, a film that satisfies all of the above relational expressions 1 and 2 can have an upper limit of 1.0% or less, 0.9% or less, 0.8% or less, 0.7% or less, 0.6% or less, 0.5% or less, 0.4% or less, or 0.3% or less in relation to relational expression 2.

[0041] In one example, the electrically conductive mesh pattern (b1) may have a fixed or irregular shape. In this case, the unit pattern forming the mesh pattern may be a polygonal shape including straight lines or a geometric shape including curved lines (see Figure 1).

[0042] In the specific examples of this application, the multiple closed figures (embossed or raised figures) demarcated by the mesh shape or electrically conductive lines of the electrically conductive mesh pattern can have a regular pattern. That is, the electrically conductive mesh pattern can be a fixed pattern in which a single unit figure (or unit pattern) is repeated. For example, the electrically conductive mesh pattern can be a pattern in which a triangular, quadrilateral, or hexagonal unit pattern is repeated.

[0043] In other specific examples of this application, the multiple closed figures (embossed or raised figures) demarcated by the mesh shape or electrically conductive lines of the electrically conductive mesh pattern may have an irregular pattern. Specifically, the electrically conductive mesh pattern may be an irregular (irregular or random) pattern containing a number of polygons that differ in shape and / or size from one another.

[0044] In one example, the dummy pattern (b2) can have a fixed or irregular shape. In this case, the unit pattern forming the dummy pattern can be a polygonal form including a straight line or a geometric form including a curved line (see Figure 1). However, as mentioned above, in the case of the unit pattern forming the dummy pattern, it is formed by separating (dropping) a part of each (conductive line) side of the polygon that is the unit pattern. For example, a fixed dummy pattern can be a repeating unit pattern of triangles, quadrilaterals, or hexagons with parts of their sides separated. An irregular dummy pattern can be a pattern in which polygons with different numbers of separated sides are randomly arranged.

[0045] In relation to the (unit) pattern shapes of each region described above, the pattern may be formed such that, when there are two branching points that form a single boundary line shared by two adjacent unit patterns, the number of boundary lines extended at each branching point is three or more.

[0046] In one example, the aperture ratio of the electrically conductive mesh pattern region can be within the range of 75 to 99%. Specifically, the lower limit of the aperture ratio of the electrically conductive mesh pattern region can be, for example, 75% or more, 80% or more, 81% or more, 82% or more, 83% or more, 84% or more, or 85% or more, and the upper limit can be, for example, 99% or less, 95% or less, specifically 90% or less, 89% or less, 88% or less, 87% or less, 86% or less, 85% or less, 84% or less, 83% or less, or 82% or less. Satisfying the above aperture ratio is advantageous not only for ensuring the transparency of the antenna film but also for improving the invisibility of the pattern by satisfying the above-described relational equations 1 and / or 2.

[0047] In the specific example of this application, the aperture ratio of the dummy pattern region can satisfy the above-described relational expression 2. For example, the aperture ratio of the dummy pattern region can be 80% or more, 81% or more, 82% or more, 83% or more, 84% or more, or 85% or more, and its upper limit can be, for example, 90% or less, 89% or less, 88% or less, 87% or less, 86% or less, 85% or less, 84% or less, 83% or less, or 82% or less.

[0048] In one example, the pitch of the electrically conductive mesh pattern region and the pitch of the dummy pattern region can be different from each other. As will be described later, the patterns of each region can be formed using the Polonoi method, and in relation to the figures that make up the pattern, pitch can mean the distance between a certain point in two adjacent unit figures (or unit patterns) when forming a pattern through Polonoi figures. By forming the regions with different pitches, it is possible to manufacture a film that satisfies relation 1 regarding pattern length and relation 2 regarding aperture ratio, thereby improving the visibility of the pattern in the transparent antenna film.

[0049] In one example, the pitch of the electrically conductive mesh pattern region can be made larger than the pitch of the dummy pattern region. The pitch of the dummy pattern region can be made relatively narrower, thereby adjusting the overall length of the dummy pattern. As a result, a film can be manufactured that satisfies relation 1 regarding pattern length and relation 2 regarding aperture ratio, thereby improving the pattern visibility of the transparent antenna film.

[0050] In one example, the pitch of the electrically conductive mesh pattern region can be 50 to 300 μm. Specifically, the electrically conductive mesh pattern region can have a pitch of, for example, 60 μm or more, 70 μm or more, 80 μm or more, 90 μm or more, 100 μm or more, 110 μm or more, 120 μm or more, 130 μm or more, 140 μm or more, 150 μm or more, 160 μm or more, 170 μm or more, 180 μm or more, 190 μm or more, or 200 μm or more. The upper limit can be, for example, 290 μm or less, 280 μm or less, 270 μm or less, 260 μm or less, 250 μm or less, 240 μm or less, 230 μm or less, 220 μm or less, 210 μm or less, 200 μm or less, 190 μm or less, 180 μm or less, 170 μm or less, 160 μm or less, 150 μm or less, 140 μm or less, 130 μm or less, 120 μm or less, 110 μm or less, or 100 μm or less.

[0051] According to a specific example of this application, the pitch and pattern shape of the dummy pattern region can be determined so as to satisfy the above-described relation 1.

[0052] In one example, the pitch of the dummy pattern region can be 50 to 300 μm. Specifically, the dummy pattern region can have a pitch of, for example, 60 μm or more, 70 μm or more, 80 μm or more, 90 μm or more, 100 μm or more, 110 μm or more, 120 μm or more, 130 μm or more, 140 μm or more, 150 μm or more, 160 μm or more, 170 μm or more, 180 μm or more, 190 μm or more, or 200 μm or more. The upper limit can be, for example, 290 μm or less, 280 μm or less, 270 μm or less, 260 μm or less, 250 μm or less, 240 μm or less, 230 μm or less, 220 μm or less, 210 μm or less, 200 μm or less, 190 μm or less, 180 μm or less, 170 μm or less, 160 μm or less, 150 μm or less, 140 μm or less, 130 μm or less, 120 μm or less, 110 μm or less, or 100 μm or less.

[0053] On the other hand, the pitch of the electrically conductive mesh pattern region can be 140 μm or more and 160 μm or less, and the pitch of the dummy pattern region can be 100 μm or more and 130 μm or less.

[0054] Assuming that the above-mentioned relations 1 and 2 are satisfied, the number of unit figures or closed figures present in each pattern can satisfy a predetermined ratio. Specifically, for regions selected of the same size, the number of unit figures present in the electrically conductive mesh pattern (N A The number of unit shapes (N) present in the dummy pattern for ) B ) ratio (N B / N A ) can be greater than 1 and less than or equal to 3.

[0055] At this time, only unit figures whose total area is within the selected region and whose area is 50% or more of the total area of ​​the unit figure are subject to the aforementioned ratio (N B / N A This is taken into consideration in the calculation, and the number of unit shapes in the dummy pattern is calculated assuming that the electrically conductive lines are extended without any separated parts.

[0056] For example, the ratio (N B / N A ) can be 1.1 or higher, 1.2 or higher, 1.3 or higher, 1.4 or higher, 1.5 or higher, 1.6 or higher, 1.7 or higher, 1.8 or higher, 1.9 or higher, 2.0 or higher, 2.1 or higher, 2.2 or higher, 2.3 or higher, 2.4 or higher, 2.5 or higher, 2.6 or higher, 2.7 or higher, 2.8 or higher, or 2.9 or higher. And its upper limit can be, for example, 2.9 or lower, 2.8 or lower, 2.7 or lower, 2.6 or lower, 2.5 or lower, 2.4 or lower, 2.3 or lower, 2.2 or lower, 2.1 or lower, 2.0 or lower, 1.9 or lower, 1.8 or lower, 1.7 or lower, 1.6 or lower, 1.5 or lower, 1.4 or lower, 1.3 or lower, 1 or lower, or 1.0 or lower.

[0057] Assuming that the above-described relationships 1 and 2 are satisfied, the line widths of the electrically conductive lines forming the electrically conductive mesh pattern and the line widths of the electrically conductive lines forming the dummy pattern can be the same or different.

[0058] In one example, the line width of the electrically conductive lines forming the electrically conductive mesh pattern and the line width of the electrically conductive lines forming the dummy pattern can be formed to be the same. Having the same line width means that the width of the pattern layer incised portion for pattern formation, or the line width of the conductive lines actually filling the incised portion, is the same within the error range. In this case, the error range can be ±0.5um or less, ±0.45um or less, ±0.40um or less, ±0.35um or less, ±0.30um or less, ±0.25um or less, ±0.20um or less, ±0.15um or less, ±0.10um or less, ±0.05um or less, or ±0.01um or less, based on the line width of the electrically conductive mesh pattern (unit: μm) described later.

[0059] In one example, the line width of the electrically conductive lines forming the electrically conductive mesh pattern may be 20 μm or less. Specifically, the line width of the electrically conductive mesh pattern may be 15 μm or less, 14 μm or less, 13 μm or less, 12 μm or less, 11 μm or less, 10 μm or less, or 9 μm or less, with the lower limit being, for example, 5 μm or more, 6 μm or more, 7 μm or more, 8 μm or more, 9 μm or more, or 10 μm or more.

[0060] In one example, the height of the electrically conductive lines forming each region unit pattern can be 4.0 μm or more. Specifically, the height can be 4.5 μm or more, 5.0 μm or more, 5.5 μm or more, 6.0 μm or more, 6.5 μm or more, 7.0 μm or more, 7.5 μm or more, 8.0 μm or more, 8.5 μm or more, 9.0 μm or more, 9.5 μm or more, or 10.0 μm or more. The upper limit can be, for example, 15.0 μm or less, 14.5 μm or less, 14.0 μm or less, 13.5 μm or less, 13.0 μm or less, 12.5 μm or less, 12.0 μm or less, 11.5 μm or less, 11.0 μm or less, 10.5 μm or less, 10.0 μm or less, 9.5 μm or less, 9.0 μm or less, 8.5 μm or less, 8.0 μm or less, 7.5 μm or less, 7.0 μm or less, 6.5 μm or less, or 6.0 μm or less.

[0061] In one example, the dummy pattern region may have unit patterns with the same shape as the unit patterns of the electrically conductive mesh pattern region. For example, as in the experiment described later, an electrically conductive mesh pattern can be prepared first, and the dummy pattern region can be formed by maintaining the shape of the prepared electrically conductive mesh pattern but designing it with a different pitch and discontinuing a part of the edges that make up the unit pattern.

[0062] In one example, the dummy pattern region can be formed with a separation length of 20 μm or less for the electrically conductive lines. Specifically, the separation length of the dummy pattern region can be, for example, 19 μm or less, 18 μm or less, 17 μm or less, 16 μm or less, 15 μm or less, 14 μm or less, 13 μm or less, 12 μm or less, 11 μm or less, or 10 μm or less. The lower limit can be, for example, 5 μm or more, 6 μm or more, 7 μm or more, 8 μm or more, 9 μm or more, 10 μm or more, 11 μm or more, 12 μm or more, 13 μm or more, 14 μm or more, 15 μm or more, 16 μm or more, 17 μm or more, or 18 μm or more. Adjusting the separation length of the dummy pattern region within the above range is advantageous in satisfying the above relational equation 2 regarding the aperture ratio.

[0063] In one example, the transparent antenna film has the same line width for the antenna wiring pattern and the dummy pattern, and the pitch of the antenna wiring pattern is greater than the pitch of the dummy wiring pattern, so that it can simultaneously satisfy the above relations 1 and 2. In such a case, the visibility of the antenna film can be further improved, as can be confirmed through experiments described later. For example, the transparent antenna film of this application comprises an electrically conductive mesh pattern region having a pitch in the range of 140 to 160 μm; and a dummy pattern region having a pitch in the range of 100 to 130 μm, wherein the line width of each pattern is formed to be the same in the range of 10 to 20 μm, and each region can simultaneously satisfy the above relations 1 and 2.

[0064] Manufacturing method for transparent antenna film

[0065] In another example relating to this application, this application relates to a method for manufacturing a transparent antenna film. The method of this application can provide the transparent antenna film described above.

[0066] The method of this application allows for the realization of a preferred pattern shape by imprinting after determining the pattern shape. A Polonoi diagram generator can be used to determine the pattern shape. Here, the Polonoi diagram generator refers to points, etc., arranged to form a Polonoi diagram as described above.

[0067] In the specific example of this application, the irregular mesh pattern can take the form of a closed geometric framework structure formed by placing arbitrary points, etc., within regularly arranged unit patterns (cells), and then connecting each point, etc., to the point closest to it relative to its distance from other points. In this case, the irregular pattern can be formed when the degree of irregularity is introduced by placing arbitrary points, etc., within the regularly arranged unit patterns. For example, if the degree of irregularity is assigned as 0, a conductive pattern will be formed as a square mesh structure if the unit cell is a square, and a conductive pattern will be formed as a honeycomb structure if the unit cell is a hexagon. In other words, the irregular pattern refers to a pattern in which the degree of irregularity is not 0.

[0068] Specifically, the above method is: A method for manufacturing a transparent antenna film comprising a base layer (A) and an electrically conductive mesh pattern layer (B) located on at least one surface of the base layer and having embossed portions and indented portions, A laminate comprising a base layer and a cured resin layer is prepared, and an incised mesh pattern formation step (S1) is formed on the cured resin layer, comprising: The process includes an electrical conductive line forming step (S2) in which a metal-containing filler is filled to a predetermined height into the engraved portion having a shape corresponding to the pattern of the mesh pattern layer (B), The electrically conductive lines constitute the electrically conductive mesh pattern of the pattern layer (B).

[0069] In relation to step (S1), the method for forming the incised mesh pattern is not particularly limited. For example, the mesh pattern can be manufactured by an imprinting method. The mold used for imprinting may have patterns corresponding to the raised and incised areas.

[0070] When forming an intaglio mesh pattern through imprinting, the pressure and temperature can be appropriately adjusted considering the type of curing resin layer, the shape of the pattern, or the size of the pattern.

[0071] Similar to the above, the incised area can be filled with fillers two or more times using fillers with different compositions.

[0072] For example, the filling may include the steps of filling the engraved portion with a first filler containing a blackening agent to form a first region containing a blackening agent (blackening agent region), and filling the first region with a second filler containing a metal to form a second region (metal region).

[0073] In other examples, the filling may include the steps of: filling the engraved portion with a first filler containing a blackening agent to form a first region (blackening agent region) containing a blackening agent; filling the first region with a second filler containing a metal to form a second region (metal region); and filling the second region with a third filler containing a blackening agent to form a third region (blackening agent region) containing a blackening agent.

[0074] In this application, an electrically conductive filler can be filled to a depth (height) less than or equal to the incised portion, and since the electrically conductive line formed by the filler is supported by the protrusion, it is possible to prevent the conductive line from collapsing or peeling off. Furthermore, through the above configuration, the thickness of the conductive line can be stably increased, which is advantageous for lowering surface resistance.

[0075] In one example, the height of the mesh pattern layer may be 50 μm or less. In this case, the height of the mesh pattern layer may mean the (vertical) distance from one surface of the mesh pattern layer in contact with the substrate layer to the opposite end of a protrusion (or the (vertical) distance from a point (P) in the mesh pattern layer in contact with the substrate layer to a point (P') in the mesh pattern layer opposite to that point. Specifically, the upper limit of the height of the mesh pattern layer may be, for example, 45 μm or less, 40 μm or less, 35 μm or less, 30 μm or less, 25 μm or less, 20 μm or less, or 15 μm or less. The lower limit may be, for example, 5 μm or more, 10 μm or more, 15 μm or more, or 20 μm or more.

[0076] In one example, the height (depth) of the engraved portion can be 20 μm or less, 15 μm or less, 10 μm or less, or 5 μm or less. The lower limit can be, for example, 4 μm or more, 5 μm or more, 6 μm or more, 7 μm or more, 8 μm or more, 9 μm or more, or 10 μm or more.

[0077] In one example, the mesh pattern layer, that is, the incised and embossed portions comprising it, may include a cured resin. Specifically, as will be described later, a cured resin layer can be formed on a substrate layer, and a mesh pattern layer including the incised and embossed portions can be formed by imprinting onto the cured resin layer. The type of cured resin included in the mesh pattern layer is not particularly limited. Any resin that can be cured by heat or light can be used without limitation, as long as it does not hinder the securing of the transparency required in this application after curing. [Effects of the Invention]

[0078] This application has the effect of providing a transparent antenna film with improved visibility (e.g., invisibility of dummy patterns). [Brief explanation of the drawing]

[0079] [Figure 1]The image shows a region containing a fixed unit pattern consisting of straight lines, as depicted in the specific example of this application (upper drawing: antenna wiring pattern region, lower drawing: dummy region). [Figure 2] The image shows a region containing an amorphous unit pattern consisting of straight lines (upper drawing: antenna wiring pattern region, lower drawing: dummy region), as shown in another specific example of this application. [Figure 3] Another specific example of this application shows a region containing a unit pattern consisting of curves (upper drawing: antenna wiring pattern region, lower drawing: dummy region). [Figure 4] This image shows a fixed pattern shape based on one specific example of this application, illustrating both an electrically conductive fixed pattern and a fixed dummy pattern. [Figure 5] Figure 4 shows the separation segments of the standard dummy pattern. [Figure 6] This image shows an unstructured pattern shape from another specific example of this application, illustrating an electrically conductive unstructured pattern and an unstructured dummy pattern. [Figure 7] Figure 6 shows the separation segments of the atypical dummy pattern. [Modes for carrying out the invention]

[0080] The function and effects of the invention will be explained in more detail below through specific embodiments of the invention. However, these are presented as examples of the invention and do not limit the scope of the invention in any way.

[0081] Evaluation methods for patterns

[0082] The characteristics of each pattern produced in Experiments 1 and 2, described later, were evaluated as follows.

[0083] (1) Optical image capture Using an optical microscope (Olympus), images of each pattern formed in transmission mode were captured at 5x magnification (resolution: 16 million pixels x 12 million pixels). The distance per pixel was 0.65258 μm. The captured images are attached to the diagram.

[0084] (2) Aperture ratio and overall pattern length The aperture ratio and pattern length for each pattern optical image were measured using image analysis software. The image analysis software analyzes the area and length of the image based on the length per unit pixel confirmed during image acquisition, and calculates the aperture ratio and total pattern length (ratio) as follows.

[0085] Specifically, the aperture ratio can be calculated as the ratio of the area where no pattern is formed to the overall area of ​​each pattern image. The pattern length ratio is calculated as the ratio of the total length of each experimental pattern to the total length of the reference pattern.

[0086] (3) Pattern visibility The "reference example sample" and the "pattern sample of each example or comparative example" for each experiment were placed adjacent to each other on a white A4 sheet of paper, and the relative visibility of the dummy wiring area was evaluated with the naked eye from a distance of 30 cm, and they were classified according to the following criteria. Strong: The pattern is relatively strongly visible. Weak: The pattern is relatively weak and difficult to perceive. Medium: The degree to which the pattern is relatively recognizable is somewhere between weak and strong.

[0087] Experiment 1: Manufacturing and evaluation of standard patterns

[0088] Manufacturing of the standard pattern in Reference Example 1: A UV-curable resin layer (approximately 10-20 μm thick) was formed on a PET substrate layer with a thickness of 125 μm. Then, a square mesh pattern layer with embossed and indented areas was formed on the cured resin layer using a soft mold. At this time, the cross-sections of the embossed and indented areas were square, the width of the indented area (pattern line width) was 10 μm, and the pattern pitch was set to 150 μm based on the center of the closed square shape.

[0089] A first region was formed by filling the incised portion of the pattern layer with a mixture of binder and carbon black, and then a second region containing Ag was formed on the first region by subsequently filling it with a mixture of binder and Ag. Furthermore, a third region containing carbon black was formed on the second region by additionally filling it with a mixture of binder and carbon black, and then heat-treated. At this time, the first to third regions had the same width as the recess, and the height of the filled first to third regions was the same as the depth of the recess. The height of the second region was approximately 4 to 5 μm of the pattern height, and the first and third regions were formed to the same height.

[0090] Manufacturing of the standard patterns for Example 1 and Comparative Examples 1-5: The standard patterns for the Examples and Comparative Examples were manufactured using the same manufacturing method as the Reference Example pattern, except that the pitch was set differently based on the center of the closed quadrilateral figure manufactured in the Reference Example, as shown in Table 1 below, and a relief of approximately 15 μm was formed at the center of each side of the closed quadrilateral figure to form a separation of the conductive lines that make up the pattern.

[0091] The specific mesh pattern configurations for the reference examples, comparative examples, and embodiments are shown in Figure 4, and the evaluation results for the manufactured standard patterns are shown in Table 1 below.

[0092] [Table 1]

[0093] Experiment 2: Manufacturing and evaluation of non-standard patterns

[0094] Manufacturing of Reference Example 2 Pattern: The pattern was formed in the same manner as in Reference Example 1, except that the quadrilateral pattern used in Reference Example 1 was used to form a pattern with a degree of irregularity of 70% on the substrate.

[0095] Manufacturing of patterns in Example 2 and Comparative Examples 6-9: Using the irregular pattern formed in Reference Example 2 as a reference, when an irregular pattern with 70% irregularity on a hexagonal base was superimposed, embossed areas (separated areas) were formed in the overlapping portions. The length of the separated areas was approximately 15 μm (production process tolerance range ±3 μm). Apart from this, the patterns were formed in the same manner as in Reference Example 1.

[0096] The specific mesh pattern types for the reference examples, comparative examples, and examples are shown in Figure 6, and the evaluation results for the manufactured non-standard patterns are shown in Table 2 below. [Table 2]

[0097] As shown in Tables 1 and 2 above, it was confirmed that the transparent antenna film according to the examples exhibits a significant improvement in pattern opacity when designed to have a structure in which the ratio of the total pattern length between the dummy pattern region and the electrically conductive mesh pattern region is 80% or more and 120% or less (Relationship 1), and the difference in the aperture ratio between the two regions is 2% or less (Relationship 2).

[0098] In other words, according to the examples, it was confirmed that when both relational equations 1 and 2 are satisfied, the invisibility of the pattern is improved to the point where it is almost impossible for the user to distinguish it with the naked eye.

[0099] On the other hand, in the comparative example, it was confirmed that if at least one of relational equations 1 or 2 is not satisfied, the pattern is strongly visible and easily recognizable by the user, which can degrade the usability and appearance quality of the transparent antenna film.

[0100] Therefore, in this embodiment, by simultaneously satisfying the above relational equations 1 and 2, it is possible to fundamentally solve the pattern visibility problem and provide a high-quality transparent antenna film that can simultaneously ensure excellent optical and electrical properties.

Claims

1. A base layer and An electrically conductive mesh pattern region located on the substrate layer, Located on the substrate layer, a portion of the electrically conductive lines forming a unit pattern is formed separately, and the electrically conductive mesh pattern region is electrically isolated from the dummy pattern region. A transparent antenna film that satisfies the following relationships 1 and 2: [Relationship 1] 80% ≤ {(total pattern length of dummy pattern area) / (total pattern length of electrically conductive mesh area)} × 100 ≤ 120% [Relationship Equation 2] |Aperture ratio of electrically conductive mesh pattern region - Aperture ratio of dummy pattern region| ≤ 2% (The dummy pattern region and the electrically conductive mesh pattern region that satisfy the above relational equation 1 can be arbitrarily selected within a size of 5 mm wide x 5 mm high.)

2. The transparent antenna film according to claim 1, wherein the electrically conductive mesh pattern in the electrically conductive mesh pattern region includes a fixed pattern or an unfixed pattern.

3. The transparent antenna film according to claim 1, wherein the aperture ratio of the electrically conductive mesh pattern region is 75 to 99%.

4. The transparent antenna film according to claim 1, wherein the pitch of the electrically conductive mesh pattern region and the pitch of the dummy pattern region are different from each other.

5. The transparent antenna film according to claim 4, wherein the pitch of the electrically conductive mesh pattern region is formed to be larger than the pitch of the dummy pattern region.

6. The transparent antenna film according to claim 4, wherein the pitch of the electrically conductive mesh pattern region is in the range of 50 μm to 300 μm.

7. The pitch of the electrically conductive mesh pattern region is 140 μm or more and 160 μm or less. The pitch of the dummy pattern region is 100 μm or more and 130 μm or less. The transparent antenna film according to claim 4.

8. For regions selected of the same size, the number of unit shapes (N) present within the electrically conductive mesh pattern. Ａ The number of unit shapes (N) present in the dummy pattern for ) Ｂ ) ratio (N Ｂ / N Ａ The transparent antenna film according to claim 1, wherein the ratio is greater than 1 and less than or equal to 3: The ratio (N Ｂ / N Ａ ) When calculating, if 50% or more of the total area of ​​the unit figure is located within the selected region, then only the unit figures that fit within the ratio (N Ｂ / N Ａ The number of unit shapes in the dummy pattern is taken into consideration in the calculation, and is calculated assuming that the electrically conductive lines are extended without any separated parts.

9. The transparent antenna film according to claim 1, wherein the line width of the electrically conductive lines forming the electrically conductive mesh pattern in the electrically conductive mesh pattern region and the line width of the electrically conductive lines forming the dummy pattern in the dummy pattern region are formed to be the same.

10. The transparent antenna film according to claim 9, wherein the line width of the electrically conductive lines forming the electrically conductive mesh pattern is 20 μm or less.

11. The transparent antenna film according to claim 1 or 4, wherein the dummy pattern region has a unit pattern having the same shape as the unit pattern of the electrically conductive mesh pattern region.

12. The transparent antenna film according to claim 1, wherein the dummy pattern region is formed with a length of 20 μm or less that separates the electrically conductive lines.

Images