Transparent antenna film

Abstract

The present invention relates to a transparent antenna film satisfying relational expressions 1 and 2, and comprising: a substrate layer; an electrically conductive mesh pattern region disposed on the substrate layer; and a dummy pattern region which is disposed on the substrate layer and electrically disconnected from the electrically conductive mesh pattern region, and which is formed by the segmentation of a portion of electrically conductive lines forming a unit pattern. The present invention provides a transparent antenna film having improved pattern invisibility. Relational expression 1: 80%≤{(total pattern length of dummy pattern region) / (total length of the electrically conductive mesh pattern region)}×100≤120%. Relational expression 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 satisfying relational expression 1 are arbitrarily selected within a size of 5 mm in width and 5 mm in length.

Description

transparent antenna film

[0001] Cross-citation with related application(s)

[0002] This application claims the benefit of priority from Korean Patent Application No. 10-2024-0070942, filed May 30, 2024, the entire contents of which are incorporated herein by reference.

[0003] The present application relates to a transparent antenna film. Specifically, the present application relates to a transparent antenna film with improved pattern invisibility.

[0004] Film-type antennas are typically configured to have a transparent antenna having one or more mesh patterns mounted on a transparent substrate. The transparent antenna is divided into a region where the antenna wiring pattern is formed and a region (dummy region) where the antenna wiring pattern is not formed. The dummy region is formed by segmenting a portion of the electrically conductive lines forming the mesh pattern and is an electrically insulated region.

[0005] There is a difference in aperture ratio between the segmented pattern area and the (non-segmented) antenna wiring pattern area. Specifically, the aperture ratio of the non-segmented area is lower than that of the segmented area. This difference in aperture ratio causes the mesh pattern (e.g., antenna wiring pattern) to be perceived by the user as unsuitable for transparent film applications.

[0006] Taking these issues into account, technologies are being developed to prevent wiring patterns from being recognized.

[0007] One purpose of the present application is to provide a transparent antenna film.

[0008] Another object of the present application is to provide a transparent antenna film with improved pattern invisibility.

[0009] The above-mentioned and other objectives of the present application can all be achieved by the present application, which is described in detail below.

[0010] According to a specific example of the present application, a transparent antenna film and a method for manufacturing the same are provided.

[0011] The transparent antenna film provided by the present application not only solves the above-described problems, but also provides optical properties (e.g., transparency, etc.) and electrical conductivity at a level equivalent to or higher than that of conventional products.

[0012] Hereinafter, the invention of the present application will be described in more detail.

[0013]

[0014] transparent antenna film

[0015] In one example of the present application, the present 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 a case where the light transmittance for light in the wavelength range of about 380 to 780 nm is 75% or more or 80% or more.

[0016] The type of the above-mentioned substrate layer (A) is not particularly limited. Any film that can secure the transparency required in the present application can be used as the substrate layer without limitation, 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.

[0017] Although not particularly limited, the lower limit of the thickness of the substrate layer may be, for example, 50 ㎛ or more, 100 ㎛ or more, 150 ㎛ or more, 200 ㎛ or more, 250 ㎛ or more, 300 ㎛ or more, 350 ㎛ or more, 400 ㎛ or more, 450 ㎛ or more, or 500 ㎛ or more. And, the upper limit may be, for example, 1000 ㎛ or less, 900 ㎛ or less, 800 ㎛ or less, 700 ㎛ or less, 600 ㎛ or less, or 500 ㎛ or less. The specific thickness of the substrate layer may be adjusted at a level that does not hinder securing the durability and transparency of the transparent antenna film.

[0018] According to the present application, the pattern (B) formed on the substrate layer may include at least two regions that are electrically disconnected from each other. Specifically, the antenna film of the present application may include a substrate layer, an electrically conductive mesh pattern region (or antenna wiring pattern region) (b1) positioned on the substrate layer; and a dummy pattern region (or dummy wiring pattern region) (b2) positioned on the substrate layer, formed by segmenting a portion of an electrically conductive line forming a unit pattern, and electrically disconnected from the electrically conductive mesh pattern region.

[0019] As described below, the pattern may be formed using a pattern layer having a raised portion and a concave portion. In this case, the concave portion has a shape corresponding to (or matching) the mesh pattern of the mesh pattern layer, and the concave portion may be filled with a conductive (e.g., metal-containing) filler to a predetermined height. As a result, electrically conductive lines containing metal may be formed within the concave portion, and an electrically conductive mesh pattern may be formed when these conductive lines intersect.

[0020] The above dummy pattern can be formed, for example, in the case where there is a unit pattern forming an entire mesh pattern, by forming a positive portion for a portion of a negative line (corresponding to a conductive line) forming the unit pattern, thereby disconnecting the negative line, and then filling the filler. The negative portion is filled with the filler to form a conductive line, and the positive portion that disconnects the negative portion is not filled with the conductive filler, so that a dummy pattern region in which a portion of the electrically conductive line is segmented can be formed through the above method.

[0021] The method by which the conductive filler is filled into the above-mentioned negative portion is not particularly limited, and a known method may be appropriately selected to fill the negative portion with the filler.

[0022] The cross-sectional shape of the engraved portion filled with the conductive filler is not particularly limited. For example, the cross-section of the engraved portion of the mesh pattern layer may have a convex arc shape in the direction of the substrate layer, or a rectangular cross-section shape including one or more inner angles. In this case, the inner angle refers to a case where two or more straight lines are connected to form a predetermined angle in the cross-section of the engraved portion. For example, when the inner angle is one, the cross-section of the engraved portion may have a triangular cross-section, and when the inner angles are two, the cross-section of the engraved portion may have a square cross-section. In a specific example of the present application, the concave portion may have a square cross-section shape.

[0023] The type of metal included in the above-mentioned negative filling material is not particularly limited. For example, the metal may include at least one 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 an alloy composed of two or more of the above-mentioned metals.

[0024] In one example, the electrically conductive filler included in (or filled into) the engraved portion may further include a blackening agent. The blackening agent can suppress the starburst phenomenon, thereby reducing visual discomfort felt by the user. For example, carbon black can be used as the blackening agent. In the prior art, blackening methods using metal materials have mainly been used, but are not sufficient to realize black (for example, copper is recognized as a dark brown). However, carbon black is a material closer to actual black, and is advantageous in ensuring visibility.

[0025] In a specific example of the present application, the filling of the negative portion with the filler may be performed two or more times with fillers having different components. Accordingly, the negative portion may be sequentially filled (included) with two or more regions (layers) containing different components. That is, the electrically conductive line formed in the negative portion may have a laminated structure of two or more regions having different components.

[0026] For example, after filling the negative portion with a first filler including a blackening material, the negative portion may be filled with a second filler including a metal. In this case, the negative portion may be filled (or included) with a first region (blackening material region) having a predetermined height and including a blackening material; and a second region (metal region) formed on the first region, having a predetermined height, and including a metal. At this time, since each filler is sequentially filled in the vertical direction within the negative portion, the first region and the second region may also be referred to as a first layer (blackening material layer) and a second layer (metal layer), respectively. In this case, considering structural stability, optical characteristics, and surface resistance, the height of the first region may be formed to be 0.5 μm or more, and the height of the second region may be formed to be 3.5 μm or more.

[0027] In another example, after filling with the second filler, filling with a third filler including a blackening material may be additionally performed. Accordingly, the engraved portion may be filled (or included) with a first region (blackening material region) having a predetermined height and including a blackening material; a second region (metal region) formed on the first region, having a predetermined height and including a metal; and a third region (blackening material region) formed on the second region, having a predetermined height and including a blackening material. At this time, since each filler is sequentially filled in the vertical direction within the engraved portion, the first region, the second region, and the third region may also be referred to as a first layer (blackening material layer), a second layer (metal layer), and a third layer (blackening material layer), respectively. In this case, considering structural stability, optical properties, and surface resistance, the height of the first region can be formed to be 0.5 ㎛ or more, the height of the second region can be formed to be 3.5 ㎛ or more, and the height of the third region can be formed to be 0.5 ㎛ or more.

[0028] In one example, the first, second, and third fillers in the negative portion may additionally include a binder (in addition to the blackening material or metal). The binder fixes the materials contained in each region and provides structural stability. The type and relative content (relative to the blackening material or metal) of the binder can be adjusted without controlling the optical properties of the antenna sought in the present application.

[0029] According to a specific example of the present application, the transparent antenna film can satisfy the following relational expression 1.

[0030] [Relationship 1]

[0031] 80 % ≤ {(total pattern length of dummy pattern area) / (total length of electrically conductive mesh pattern area)} x 100 ≤ 120 %

[0032] At this time, the dummy pattern area and the electrically conductive mesh pattern area satisfying relational expression 1 may be areas randomly selected within a size of 5 mm wide x 5 mm high (e.g., a randomly selected rectangular area). In addition, the total length of each pattern may be calculated based on an image of the pattern taken with an optical microscope, as described below.

[0033] As confirmed through the experiment below, the invisibility of a pattern can be improved if the above relation 1 is satisfied. In other words, the invisibility of a pattern can be improved through a design that satisfies relation 1.

[0034] In one example, the lower bound of relation 1 may be greater than or equal to 85%, greater than or equal to 90%, greater than or equal to 95%, or greater than or equal to 100%. And, the upper bound of relation 1 may be, for example, less than or equal to 115%, less than or equal to 110%, or less than or equal to 105%.

[0035] The upper and lower limits of the values ​​of relational expression 1 can be adjusted according to the shape, line width, and / or aperture ratio of each area pattern. That is, the shape, line width, aperture ratio, and pattern length of each area pattern can be adjusted to secure optimal visibility.

[0036] According to a specific example of the present application, the transparent antenna film can satisfy the following relational expression 2.

[0037] [Relationship 2]

[0038] | Aperture ratio of electrically conductive mesh pattern area - Aperture ratio of dummy pattern area| ≤ 2%

[0039] At this time, the aperture ratio of each pattern can be calculated based on an image of the pattern taken with an optical microscope, as described below.

[0040] As confirmed through the experiment below, the invisibility of a pattern can be improved if the above relation 2 is satisfied. In other words, the invisibility of a pattern can be improved through a design that satisfies relation 2.

[0041] In one example, the lower bound of relation 2 may be greater than or equal to 0.5%, greater than or equal to 1.0%, or greater than or equal to 1.5%. And the upper bound may be, for example, less than or equal to 1.5%, less than or equal to 1.0%, or less than or equal to 0.5%.

[0042] The upper and lower limits of the values ​​of relational expression 2 can be adjusted according to the shape, line width, and / or (total) length of each area pattern. That is, the shape, line width, aperture ratio, and pattern length of each area pattern can be adjusted to secure optimal visibility.

[0043] In relation to the above-described relations 1 and 2, when the pattern pitch of the dummy region is formed relatively narrowly, the total length of the pattern may increase as the number of unit patterns within the dummy region increases. In addition, if such a tendency increases excessively, the aperture ratio of the dummy region is greatly reduced, resulting in the dummy region being strongly visible. In the opposite case, either the dummy region or the conductive pattern region may also be strongly visible. Therefore, as explained in relation to relations 1 and 2, it is necessary to appropriately design the inter-region pitch size, the total length of the pattern, and the aperture ratio (taking the line width into consideration).

[0044] In one example, the transparent antenna film may satisfy both the above relationships 1 and 2. According to a specific example of the present application, a film satisfying both the above relationships 1 and 2 may have a lower limit value of more than 100% with respect to the relationship 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. And, a film satisfying both the above relationships 1 and 2 may have an upper limit value 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 with respect to the relationship 2.

[0045] In one example, the electrically conductive mesh pattern (b1) may have a regular 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 Fig. 1).

[0046] In a specific example of the present application, the plurality of closed figures (embossed or convex figures) defined by the mesh shape or electrically conductive lines of the electrically conductive mesh pattern may have a regular shape. That is, the electrically conductive mesh pattern may be a regular pattern in which one unit figure (or unit pattern) is repeated. For example, the electrically conductive mesh pattern may be a pattern in which unit patterns of triangles, squares, or hexagons are repeated.

[0047] In another specific embodiment of the present application, the plurality of closed shapes (embossed or convex shapes) defined by the mesh shape or electrically conductive lines of the electrically conductive mesh pattern may have an irregular shape. Specifically, the electrically conductive mesh pattern may be an irregular (irregular or random) pattern comprising a plurality of polygons having different shapes and / or sizes.

[0048] In one example, the dummy pattern (b2) may have a regular or irregular shape. In this case, the unit pattern forming the dummy pattern may be a polygonal shape including a straight line or a geometric shape including a curved line (see FIG. 1). However, in the case of the unit pattern forming the dummy pattern as described above, a portion of each (conductive line) side forming the polygon, which is the unit pattern, is formed by segmenting (omitting). For example, the regular dummy pattern may be a repeating unit pattern of a triangle, square, or hexagon with a portion of the side segmented. In addition, the irregular dummy pattern may be a pattern in which polygons with different numbers of sides with a portion of the side segmented are randomly arranged.

[0049] With respect to the (unit) pattern shape of each region described above, the pattern may be formed so that, when there are two branching points forming one boundary line (line) shared by two adjacent unit patterns, the number of boundary lines extending from each branching point is three or more.

[0050] In one example, the aperture ratio of the electrically conductive mesh pattern region may be within the range of 75 to 99%. Specifically, the lower limit of the aperture ratio of the electrically conductive mesh pattern region may 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 may be, for example, 99% or less or 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. When the above aperture ratio is satisfied, it is advantageous not only for securing transparency of the antenna film, but also for improving the invisibility of the pattern by satisfying the above-described relational expressions 1 and / or 2.

[0051] In a specific example of the present 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 the upper limit thereof 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.

[0052] In one example, the pitch of the electrically conductive mesh pattern region and the pitch of the dummy pattern region may be different from each other. As described below, the pattern of each region may be formed using the Voronoi method, and with respect to the shape forming the pattern, the pitch may refer to the distance between parent points in two adjacent unit shapes (or unit patterns) when forming a pattern using a Voronoi shape. By forming the pitch between regions differently, a film satisfying the relationship 1 regarding the pattern length and the relationship 2 regarding the aperture ratio can be manufactured, and the pattern visibility of the transparent antenna film can be improved.

[0053] In one example, the pitch of the electrically conductive mesh pattern region can be formed to be larger than the pitch of the dummy pattern region. By forming the pitch of the dummy pattern region to be relatively narrow, the total length of the dummy pattern can be controlled. Consequently, a film satisfying the relationship 1 regarding the pattern length and the relationship 2 regarding the aperture ratio can be manufactured, and the pattern visibility of the transparent antenna film can be improved.

[0054] In one example, the pitch of the electrically conductive mesh pattern region may be 50 to 300 μm. Specifically, the electrically conductive mesh pattern region may 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. And, 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.

[0055] According to a specific example of the present application, the pitch and pattern shape of the dummy pattern area can be determined so as to satisfy the above-described relational expression 1.

[0056] In one example, the pitch of the dummy pattern region may be 50 to 300 μm. Specifically, the dummy pattern region may 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. And, 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.

[0057] Meanwhile, the pitch of the electrically conductive mesh pattern region may be 140 ㎛ or more and 160 ㎛ or less, and the pitch of the dummy pattern region may be 100 ㎛ or more and 130 ㎛ or less.

[0058] Assuming that the above-described relations 1 and 2 are satisfied, the number of unit figures or closed figures existing in each pattern can satisfy a predetermined ratio. Specifically, for areas selected with the same size, the number of unit figures existing in the electrically conductive mesh pattern (N A ) the number of unit figures present in the dummy pattern (N) B ) ratio (N) B / N A ) may be greater than 1 and less than or equal to 3.

[0059] At this time, only unit figures that exist within the selected area, where more than 50% of the total area of ​​the unit figure is selected, are included in the ratio (N B / N A) is considered in the calculation, and the number of unit figures of the dummy pattern is calculated assuming that the electrically conductive line is extended without any segmented portion.

[0060] For example, the above 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, the upper limit can be, for example, 2.9 or less, 2.8 or less, 2.7 or less, 2.6 or less, 2.5 or less, 2.4 or less, 2.3 or less, 2.2 or less, 2.1 or less, 2.0 or less, 1.9 or less, 1.8 or less, 1.7 or less, 1.6 or less, 1.5 or less, 1.4 or less, 1.3 or less, 1.2 or less, 1.1 or less, or 1.0 or less.

[0061] Assuming that the above-described relations 1 and 2 are satisfied, the line width of the electrically conductive line forming the electrically conductive mesh pattern and the line width of the electrically conductive line forming the dummy pattern can be formed to be the same or different.

[0062] In one example, the line width of the electrically conductive line forming the electrically conductive mesh pattern and the line width of the electrically conductive line forming the dummy pattern may be formed to be the same. The same line width means that the width of the engraved portion of the pattern layer for pattern formation or the line width of the conductive line actually filled in the engraved portion are the same within an error range. At this time, the error range may be ± 0.5 um or less, ± 0.45 um or less, ± 0.40 um or less, ± 0.35 um or less, ± 0.30 um or less, ± 0.25 um or less, ± 0.20 um or less, ± 0.15 um or less, ± 0.10 um or less, ± 0.05 um or less, or ± 0.01 um or less, based on the line width (unit: um) of the electrically conductive mesh pattern described below.

[0063] In one example, the line width of the electrically conductive line forming the electrically conductive mesh pattern may be 20 um or less. Specifically, the line width of the electrically conductive mesh pattern may be 15 um or less, 14 um or less, 13 um or less, 12 um or less, 11 um or less, 10 um or less, or 9 um or less, and the lower limit thereof may be, for example, 5 um or more, 6 um or more, 7 um or more, 8 um or more, 9 um or more, or 10 um or more.

[0064] In one example, the height of the electrically conductive line forming each area unit pattern may be 4.0 μm or more. Specifically, the height may 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. And, the upper limit may be, for example, 15.0 ㎛ or less, 14.5 ㎛ or less, 14.0 ㎛ or less, 13.5 ㎛ or less, 13.0 ㎛ or less, 12.5 ㎛ or less, 12.0 ㎛ or less, 11.5 ㎛ or less, 11.0 ㎛ or less, 10.5 ㎛ or less, 10.0 ㎛ or less, 9.5 ㎛ or less, 9.0 ㎛ or less, 8.5 ㎛ or less, 8.0 ㎛ or less, 7.5 ㎛ or less, 7.0 ㎛ or less, 6.5 ㎛ or less, or 6.0 ㎛ or less.

[0065] In one example, the dummy pattern region may have a unit pattern having the same shape as the unit pattern of the electrically conductive mesh pattern region. For example, as in the experiment described below, the dummy pattern region may be formed by first preparing an electrically conductive mesh pattern, maintaining the shape of the prepared electrically conductive mesh pattern as is but designing a different pitch, and cutting off part of the sides forming the unit pattern.

[0066] In one example, the dummy pattern region may be formed such that the segmented length of the electrically conductive line is 20 um or less. Specifically, the segmented length of the dummy pattern region may be, for example, 19 um or less, 18 um or less, 17 um or less, 16 um or less, 15 um or less, 14 um or less, 13 um or less, 12 um or less, 11 um or less, or 10 um or less. And, the lower limit may be, for example, 5 um or more, 6 um or more, 7 um or more, 8 um or more, 9 um or more, 10 um or more, 11 um or more, 12 um or more, 13 um or more, 14 um or more, 15 um or more, 16 um or more, 17 um or more, or 18 um or more. When the segment length of the dummy pattern area is adjusted within the above-described range, it is more advantageous to satisfy the above relational expression 2 regarding the aperture ratio.

[0067] In one example, the transparent antenna film may have the same line widths of the antenna wiring pattern and the dummy pattern, a pitch of the antenna wiring pattern is larger than a pitch of the dummy wiring pattern, and may simultaneously satisfy the above-described relationships 1 and 2. In this case, as will be confirmed through the experiment described below, the visibility of the antenna film can be further improved. For example, the transparent antenna film of the present application may have an electrically conductive mesh pattern region having a pitch in the range of 140 to 160 um; and a dummy pattern region having a pitch in the range of 100 to 130 um, and the line widths of each pattern are formed equally in the range of 10 to 20 um, and each region may simultaneously satisfy the above-described relationships 1 and 2.

[0068]

[0069] Method for manufacturing transparent antenna film

[0070] In another example of the present application, the present application relates to a method for manufacturing a transparent antenna film. The method of the present application can provide the transparent antenna film described above.

[0071] The method of the present application may first determine the desired pattern shape and then implement it using an imprinting method. A Voronoi diagram generator may be used to determine the pattern shape. Here, the Voronoi diagram generator refers to points arranged to form a Voronoi diagram, as described above.

[0072] In a specific example of the present application, the irregular mesh pattern may be in the form of a border structure of closed figures formed by arranging random points within regularly arranged unit patterns (cells) and connecting each point to the closest point relative to the distance from other points. In this case, the irregular pattern may be formed when irregularity is introduced into the method of arranging random points within the regularly arranged unit patterns. For example, when the irregularity is set to 0, if the unit unit cell is a square, the conductive pattern forms a square mesh structure, and if the unit unit cell is a regular hexagon, the conductive pattern forms a honeycomb structure. In other words, the irregular pattern refers to a pattern whose irregularity is not 0.

[0073] Specifically, the above method,

[0074] A method for manufacturing a transparent antenna film comprising a substrate layer (A); and an electrically conductive mesh pattern layer (B) positioned on at least one surface of the substrate layer and having a positive portion and a negative portion,

[0075] A step (S1) of forming a negative mesh pattern by preparing a laminate including a substrate layer and a cured resin layer, and forming a mesh pattern including a negative portion and a positive portion on the cured resin layer; and

[0076] It includes an electrically conductive line forming step (S2) of filling a filler including a metal to a predetermined height in the engraved portion having a shape corresponding to the pattern of the mesh pattern layer (B).

[0077] The above electrically conductive lines constitute an electrically conductive mesh pattern of the pattern layer (B).

[0078] With regard to the above step (S1), the method for forming the negative mesh pattern is not particularly limited. For example, the above mesh pattern may be manufactured by an imprinting method. The mold performing the imprinting may have patterns corresponding to the positive and negative portions.

[0079] When forming an intaglio mesh pattern through imprinting, the pressure and temperature can be appropriately adjusted by considering the type of cured resin layer, the shape of the pattern, or the size of the pattern.

[0080] As described above, the filling of the negative portion by the filler may be performed two or more times by fillers having different components.

[0081] For example, the filling may include a step of filling a first filler including a blackening material into the engraved portion to form a first region (blackening material region) including the blackening material; and a step of filling a second filler including a metal onto the first region to form a second region (metal region).

[0082] In another example, the filling may include: filling a first filler including a blackening material into the engraved portion to form a first region (blackening material region) including the blackening material; filling a second filler including a metal onto the first region to form a second region (metal region); and filling a third filler including a blackening material onto the second region to form a third region (blackening material region) including the blackening material.

[0083] In the present application, an electrically conductive filler can be filled to a depth (height) below the concave portion, and the electrically conductive line formed by the filler is supported by the convex portion, thereby preventing the conductive line from collapsing or peeling. Furthermore, the thickness of the conductive line can be stably increased through the above-described configuration, which is advantageous in reducing surface resistance.

[0084] In one example, the height of the mesh pattern layer may be 50 μm or less. At this time, the height of the mesh pattern layer may mean the (vertical) distance from one side of the mesh pattern layer in contact with the substrate layer to one end of the convex portion located on the opposite side (or the (vertical) distance from a point (P) of the mesh pattern layer in contact with the substrate layer to a point (P') of the mesh pattern layer opposite the 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.

[0085] In one example, the height (depth) of the engraved portion may be 20 μm or less, 15 μm or less, 10 μm or less, or 5 μm or less. And, the lower limit may 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.

[0086] In one example, the mesh pattern layer, i.e., the engraved portion and the relief portion forming the mesh pattern layer, may include a curable resin. Specifically, as described below, a curable resin layer may be formed on a substrate layer, and a mesh pattern layer including the engraved portion and the relief portion may be formed through imprinting the curable resin layer. The type of curable resin included in the mesh pattern layer is not particularly limited. Any resin that can be cured by heat or light may be used without limitation, as long as it does not hinder securing the transparency required in the present application after curing.

[0087]

[0088] The present application has the effect of providing a transparent antenna film with improved visibility (e.g., invisibility of a dummy pattern).

[0089] FIG. 1 is a photograph of an area (upper drawing: antenna wiring pattern area, lower drawing: dummy area) including a regular unit pattern formed of straight lines according to a specific example of the present application.

[0090] FIG. 2 is a photograph of an area (upper drawing: antenna wiring pattern area, lower drawing: dummy area) including an amorphous unit pattern formed of straight lines according to another specific example of the present application.

[0091] FIG. 3 is a photograph of an area including a unit pattern formed of curves (upper drawing: antenna wiring pattern area, lower drawing: dummy area) according to another specific example of the present application.

[0092] FIG. 4 is a photograph of a regular pattern shape according to one specific example of the present application, showing an electrically conductive regular pattern and a regular dummy pattern.

[0093] Figure 5 illustrates the segmented joints of the regular dummy pattern illustrated in Figure 4.

[0094] FIG. 6 is a photograph of an amorphous pattern shape according to another specific example of the present application, showing an electrically conductive amorphous pattern and an amorphous dummy pattern.

[0095] Figure 7 illustrates the segmented nodes of the irregular dummy pattern illustrated in Figure 6.

[0096]

[0097] The following specific examples of the invention will further illustrate its functions and effects. However, these examples are presented as illustrative examples and do not limit the scope of the invention in any way.

[0098]

[0099] Evaluation method for patterns

[0100] The characteristics of each pattern manufactured in Experiments 1 and 2 described below were evaluated as follows.

[0101] (1) Optical image capture

[0102] Images of each pattern formed in transmission mode were captured at 5x magnification (resolution: 16 million pixels x 12 million pixels) using an optical microscope (Olympus). The distance per unit pixel is 0.65258 μm. The captured images are attached to the drawing.

[0103] (2) Aperture ratio and total pattern length

[0104] The aperture ratio and pattern length for each pattern optical image were measured using image analysis software. The image analysis software analyzes the image area and length based on the length per unit pixel determined during image capture, and calculates the aperture ratio and total pattern length (ratio) as follows.

[0105] Specifically, the aperture ratio can be calculated as the ratio of the area of ​​the entire image of each pattern to the area where the pattern is not formed. In addition, the pattern length ratio is calculated as the ratio of the total length of each experimental example pattern to the total length of the reference example pattern.

[0106] (3) Pattern visibility

[0107] The 'reference example sample' of each experiment and the 'sample of each example or comparative example pattern' were placed adjacent to each other on white A4 paper, and the relative visibility of the dummy wiring area was evaluated visually from a distance of 30 cm, and classified according to the following criteria.

[0108] River: The pattern is relatively strongly recognized

[0109] Weak: Relatively weak pattern recognition

[0110] Medium: The degree of recognition of the pattern is relatively between weak and strong.

[0111]

[0112] Experiment 1: Fabrication and Evaluation of Standard Patterns

[0113] Manufacturing of a regular pattern of Reference Example 1: A UV-curable resin layer (approximately 10-20 μm thick) was formed on a PET substrate layer having a thickness of 125 μm. Then, a square mesh pattern layer having a raised portion and a lower portion was formed on the cured resin layer using a soft mold. At this time, the cross-sections of the raised portion and the lower portion were square, the width of the lower portion (pattern line width) was 10 μm, and the pattern pitch was set to 150 μm based on the center of the square closed shape.

[0114] A first region was formed by filling a mixture of a binder and carbon black into the engraved portion of the pattern layer, and then a second region containing Ag was formed on the first region by filling a mixture of a binder and Ag. In addition, a third region containing carbon black was formed on the second region by further filling a mixture of a binder and carbon black, and heat treatment was performed. At this time, the first to third regions had the same width as the concave portion, and the heights of the first to third regions were equal to the depth of the concave portion. The height of the second region among the pattern heights was approximately 4 to 5 μm, and the first and third regions were formed to have the same height.

[0115] Manufacturing of regular patterns in Example 1 and Comparative Examples 1-5: Regular patterns in Examples and Comparative Examples were manufactured using the same manufacturing method as the pattern in the Reference Example, except that the pitch based on the center of the closed rectangular shape manufactured in the Reference Example was set differently as shown in Table 1 below, and that a segmented portion of the conductive line forming the pattern was formed by forming a raised portion of about 15 um at the center of each closed rectangular shape side.

[0116] The specific mesh pattern forms of the reference examples, comparative examples, and examples are as shown in Fig. 4, and the evaluation results for the manufactured regular patterns are as shown in Table 1 below.

[0117]

[0118] Regular patternPattern pitch(μm)Pattern total length(μm)Pattern total length ratio(%)Aperture ratio(%)Aperture ratio difference(%)Pattern visibilityReference example 115013,744-81.1--Comparative example 115012,1708983.92.8Strong (antenna area visible)Example 112514,34710481.60.5Weak Comparative example 211516,31011982.11.0Heavy (antenna area visible)Comparative example 310516,34411979.91.2Heavy (dummy area visible)Comparative example 49517,97913177.14.0Strong (dummy area visible)Comparative example 58020,44314975.45.7강 (dummy area recognized)* Pattern total length ratio: % ratio of the total length of each experimental example pattern to the total length of the reference example pattern* Difference in aperture ratio: Absolute value of the difference between the aperture ratio of the reference example pattern and the aperture ratio of each experimental example pattern* The number of unit figures for which pattern visibility was evaluated in Reference Example 1 was 35, and the number of unit figures for which pattern visibility was evaluated in Example 1 (assuming that the segmented areas were connected) was 48.

[0119]

[0120] Experiment 2: Fabrication and Evaluation of Irregular Patterns

[0121] Reference Example 2 Pattern Manufacturing: A pattern was formed in the same manner as in Reference Example 1, except that a pattern with an irregularity of 70% was formed based on the square pattern used in Reference Example 1.

[0122] Manufacturing of Patterns of Example 2 and Comparative Examples 6-9: Based on the irregular pattern formed in Reference Example 2, when overlapping irregular patterns with an irregularity of 70% based on hexagons, a raised portion (segmented portion) was formed in the overlapping portion. The segmented length is approximately 15 um (production process error range ±3 um). Except for this, the pattern was formed in the same manner as in Reference Example 1.

[0123] The specific mesh pattern forms of the reference examples, comparative examples, and examples are as shown in Fig. 6, and the evaluation results for the manufactured irregular patterns are as shown in Table 2 below.

[0124]

[0125] Atypical patternPattern pitch(μm)Pattern total length(μm)Pattern total length ratio(%)Aperture ratio(%)Aperture ratio difference(%)Pattern visibilityReference example 215015,747-81.7--Comparative example 615011,3887287.55.8Reinforcement (antenna area visible)Comparative example 713513,0768385.84.1Reinforcement (antenna area visible)Comparative example 812513,6578785.33.6Reinforcement (antenna area visible)Comparative example 911514,4079184.83.1Reinforcement (antenna area visible)Example 210017,00610881.20.5About* Pattern total length ratio: Reference example pattern total length for each experimental example pattern % ratio of total length* Difference in aperture ratio: Absolute value of the difference between the aperture ratio of the reference example pattern and the aperture ratio of each experimental example pattern* The number of unit figures for which pattern visibility was evaluated in Reference Example 2 was 35, and the number of unit figures for which pattern visibility was evaluated in Example 2 (assuming that segmented areas were connected) was approximately 85.

[0126]

[0127] As shown in Tables 1 and 2 above, it was confirmed that the transparent antenna film according to the embodiments exhibits the effect of significantly improving the invisibility of the pattern by being designed to have a structure in which the total pattern length ratio between the dummy pattern area and the electrically conductive mesh pattern area is 80% or more and 120% or less (Relationship 1) and the difference in aperture ratio between the two areas is 2% or less (Relationship 2).

[0128] That is, according to the embodiment, when both the above relations 1 and 2 are satisfied, it was confirmed that the invisibility of the pattern was improved to the extent that it was barely discernible to the user with the naked eye.

[0129] On the other hand, in the comparative example, if at least one of relation 1 or 2 is not satisfied, the pattern is strongly visible and can be easily recognized by the user, and it was confirmed that this may deteriorate the usability and appearance quality of the transparent antenna film.

[0130] Therefore, in the embodiments, by simultaneously satisfying the above relationships 1 and 2, it is possible to fundamentally solve the pattern visibility problem and provide a high-quality transparent antenna film that can simultaneously secure excellent optical and electrical properties.

Claims

1. Base layer; an electrically conductive mesh pattern region positioned on the above substrate layer; and A portion of an electrically conductive line formed on the above substrate layer and segmented to form a unit pattern, and having a dummy pattern region electrically disconnected from the electrically conductive mesh pattern region, A transparent antenna film satisfying the following relationships 1 and 2: [Relationship 1] 80 % ≤ {(total pattern length of dummy pattern area) / (total length of electrically conductive mesh pattern area)} x 100 ≤ 120 % [Relationship 2] | Aperture ratio of electrically conductive mesh pattern area - Aperture ratio of dummy pattern area| ≤ 2% (The dummy pattern area and the electrically conductive mesh pattern area satisfying the above relational expression 1 are randomly selected within a size of 5 mm wide x 5 mm high).

2. In paragraph 1, A transparent antenna film wherein the electrically conductive mesh pattern includes a regular pattern or an irregular pattern.

3. In paragraph 1, A transparent antenna film having an opening ratio of the electrically conductive mesh pattern region of 75 to 99%.

4. In paragraph 1, A transparent antenna film, wherein the pitch of the electrically conductive mesh pattern region and the pitch of the dummy pattern region are different from each other.

5. In paragraph 4, A transparent antenna film in which the pitch of the electrically conductive mesh pattern region is formed to be larger than the pitch of the dummy pattern region.

6. In paragraph 4, A transparent antenna film, wherein the pitch of the electrically conductive mesh pattern region is in the range of 50 ㎛ to 300 ㎛.

7. In paragraph 4, The pitch of the above electrically conductive mesh pattern region is 140 ㎛ or more and 160 ㎛ or less, The pitch of the above dummy pattern area is 100 ㎛ or more and 130 ㎛ or less, Transparent antenna film.

8. In paragraph 1, For a selected area of ​​equal size, the number of unit figures (N) present within the electrically conductive mesh pattern A ) the number of unit figures present in the dummy pattern (N) B ) ratio (N) B / N A ) is greater than 1 and less than or equal to 3, transparent antenna film: The above ratio (N B / N A ) When calculating, only unit figures that are more than 50% of the total area of ​​the unit figure and exist within the selected area are included in the ratio (N B / N A ) is considered in the calculation, and the number of unit figures of the dummy pattern is calculated assuming that the electrically conductive line is extended without any segmented portion.

9. In paragraph 1, A transparent antenna film in which the line width of the electrically conductive line forming the electrically conductive mesh pattern and the line width of the electrically conductive line forming the dummy pattern are formed to be the same.

10. In paragraph 9, A transparent antenna film, wherein the line width of the electrically conductive line forming the electrically conductive mesh pattern is 20 um or less.

11. In paragraph 1 or paragraph 4, A transparent antenna film, wherein the above dummy pattern region has a unit pattern having the same shape as the unit pattern of the above electrically conductive mesh pattern region.

12. In paragraph 1, The above dummy pattern region is a transparent antenna film in which electrically conductive lines are formed with a segmented length of 20 um or less.

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