WO2016137098A2

WO2016137098A2 - Conductive sheet

Info

Publication number: WO2016137098A2
Application number: PCT/KR2015/013542
Authority: WO
Inventors: 신명동; 이규만; 최인규; 문종건
Original assignee: (주)뉴옵틱스; 유주티엔씨(주)
Priority date: 2015-02-23
Filing date: 2015-12-10
Publication date: 2016-09-01
Also published as: KR20160103214A; WO2016137098A3

Abstract

The present invention relates to a conductive sheet having improved filling efficiency and electric properties, comprising: a base layer; an intaglio pattern formed in the depth direction of the base layer; and a conductive paste filled inside the intaglio pattern, wherein the intaglio pattern comprises extended patterns recessed in the width direction of the base layer.

Description

Conductive sheet

The present invention relates to a conductive sheet, and more particularly to a conductive sheet with improved filling efficiency and electrical properties.

In recent years, with the trend of light and shortening of electronic products, electronic devices such as displays or transistors are commonly required to be manufactured in a high density and high density form, and thus a technology of forming a metal pattern that can be used for electrodes or wiring has been attracting attention. In particular, the application of the touch panel to the sensor electrode or the wiring electrode has attracted much attention.

Various processes are applied to the production of such metal patterns, and the situation is that both the embossed and intaglio metal pattern technologies are compatible. Although each technique has advantages and disadvantages, the engraved metal pattern technique is attracting attention because it can reduce the thickness of the sheet and has an easier manufacturing process.

In addition, among various techniques for filling conductive paste in intaglio metal patterns, a filling method using squeeze has been attracting attention in terms of simple facility equipment.

However, when the filling method using the squeeze is applied, there is a problem that the conductive paste is pushed out of the intaglio pattern by squeeze pressurization when the width of the intaglio metal pattern is wide. The same micro protrusions were formed to prevent the rolling of the conductive paste. However, when the thickness of the substrate on which the intaglio pattern is formed is thin, especially when the material of the substrate is a soft polymer resin, there is a problem that the micro-projections collapse by the squeeze press, ie, fall off from the substrate layer.

Therefore, there is a need for the development of a conductive sheet that can prevent a phenomenon in which the conductive paste is pushed out during the filling process using the squeeze on the conductive sheet on which the intaglio pattern is formed or a defect in which the micro protrusions inside the intaglio pattern collapse.

An object of the present invention is to provide a conductive sheet which can improve the filling efficiency and electrical properties while solving the problems of the prior art.

However, the technical problem to be solved by the present invention is not limited to the technical problem mentioned above, and other technical problems not mentioned are clearly to those skilled in the art from the following description. It can be understood.

Conductive sheet of the present invention for achieving the above object is a base layer; Intaglio pattern implemented in the depth direction of the base layer; And a conductive paste filled in the intaglio pattern, wherein the intaglio pattern includes expansion patterns recessed in the width direction of the base layer.

In one embodiment, the extension patterns may be formed on both sides of the intaglio pattern, the extension patterns on each side may be formed to be spaced apart from each other, and the extension patterns on both sides may be alternately formed.

In another embodiment, the extension patterns may be a spherical or elliptical partial shape.

In another embodiment, a plurality of partition patterns or minute protrusions may be formed inside the intaglio pattern.

In another embodiment, the expansion patterns may be a spherical or oval partial shape, and the partition pattern may be a unit structure in which spherical or oval shapes are combined with rod shapes.

In another embodiment, the bottom thickness of the base layer formed by the bottom surface of the base layer and the bottom surface of the intaglio pattern may be 1 to 5 μm.

In another embodiment, the conductive paste includes two kinds of spherical metal particles having different diameters, and among the spherical metal particles, a spherical metal particle having a small diameter is stacked on top of the larger spherical metal particle. It can have

The present invention derived to solve the problems of the prior art as described above, the engraved pattern may include an expansion pattern recessed in the width direction of the base layer to improve the filling efficiency and electrical properties,

In addition, it is possible to further improve the filling efficiency of the conductive sheet by forming a partition pattern or a small projection pattern inside the intaglio pattern,

In addition, it is possible to further improve the electrical properties of the conductive sheet by the laminated structure of two kinds of spherical metal particles having different diameters.

1 is a cross-sectional view of a conductive sheet according to an embodiment of the present invention.

2 is a plan view of a conductive sheet on which an extension pattern is formed according to an embodiment of the present invention.

3 and 4 are plan views of the conductive sheet on which the partition pattern and the minute protrusions are formed according to the exemplary embodiment of the present invention.

5 is a cross-sectional view of a conductive sheet filled with two conductive pastes according to an embodiment of the present invention.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all transformations, equivalents, and substitutes included in the spirit and scope of the present invention. In the following description of the present invention, if it is determined that the detailed description of the related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present application, terms such as “characterize”, “comprise” or “have” are intended to designate that the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification are present, It should be understood that it does not exclude in advance the possibility of the presence or addition of one or more other features or numbers, steps, operations, components, parts or combinations thereof.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, in describing the present invention, descriptions of already known functions or configurations will be omitted to clarify the gist of the present invention.

1 is a cross-sectional view of a conductive sheet according to an embodiment of the present invention, Figure 2 is a plan view of a conductive sheet is formed expansion pattern according to an embodiment of the present invention.

As shown in FIG. 1, in the conductive sheet 100 of the present invention, the conductive paste 900 is filled in the intaglio pattern 300 formed in the depth direction of the base layer 200.

The conductive sheet 100 includes all objects included in the object range of the present invention in which the conductive paste 900 is filled in the intaglio pattern 300 regardless of its use and terminology. Preferably, it can be used for the wiring electrode of the touch panel.

The base layer 200 may be made of a material having glass, quartz, resin, and the like, and any material or composite material commonly used as a general base substrate may be used as the base layer 200 of the present invention. In the base layer 200, the intaglio pattern 300 is easily formed, and a polymer resin material is preferable in order to apply the flexible electronic device.

In the present invention, the intaglio pattern 300 is formed in the depth direction of the base layer 200, and known techniques such as etching, etching, and roll imprint may be applied. The intaglio pattern 300 can reduce the thickness of the sheet compared to the embossed pattern, and has an advantage in mass production because the process is easier in the pattern generation.

Width width (D) and height (H1) of the intaglio pattern 300 is to the extent that the conductive paste 900 is filled to achieve sufficient conductivity, it can be variously adjusted according to the intended use.

In the present invention, the conductive paste 900 refers to the conductive material 700 and the binder 800, and includes all the known materials that play an electrically conductive role regardless of names such as conductive ink and conductive paste.

The conductive material 700 includes all known conductive materials 700 used in the conductive paste 900 such as metal particles, organometallic particles, nanowires, graphene, carbon nanotubes, conductive polymers, and composite materials thereof. .

Regardless of the terminology, the binder 800 may be a polymer resin in which the conductive material 700 is dispersed to form a framework of the conductive paste 900, a surfactant-based dispersant to ensure dispersibility of the conductive material, a viscosity of a resin, Means all components except the conductive material 700, such as additives, solvents for improving the flowability.

As illustrated in FIG. 2, the conductive sheet 100 of the present invention includes an expansion pattern 400 recessed in the width direction of the base layer 200. 2 (a) to 2 (c) show an embodiment in which the expansion pattern 400 is a spherical partial shape, a triangular shape, or a rectangular shape, but is not limited thereto.

Spherical or elliptical partial expansion pattern 400 is easier to manufacture than polygonal shape, and has a curvature to improve the flow efficiency of the conductive paste compared to the polygonal shape to improve the filling efficiency of the conductive paste (900) It is more preferable because it has.

Depressed in the width direction of the base material layer 200 means a concave shape entered into the outer side of the intaglio pattern 300 longitudinal line as shown in FIG.

In the expansion pattern 400 recessed in the width direction of the base layer 200, the conductive paste has fluidity as the conductive paste secures a constant spatiality when the squeeze is filled in the intaglio pattern 300, compared to a simple intaglio pattern. ) Has an effect of improving the filling efficiency, it has excellent electrical conductivity and low resistance by this filling efficiency.

In addition, when filling the conductive paste 900 by using a squeeze, in order to prevent the rolling of the conductive paste 900, conventionally, a small protrusion was formed inside the intaglio pattern, thereby preventing the base layer 202 and the bottom surface of the intaglio pattern ( When the lower thickness H2 of the base layer 301 is less than or equal to 5 µm, the micro-projections inside the intaglio pattern collapse and cause defects. However, in the present invention, the defects do not occur even when the lower thickness H2 is less than or equal to 5 µm. In addition, even if the base layer lower thickness (H2) 1 to 3㎛ has the advantage that the defect does not occur.

In addition, by the substrate layer lower thickness (H2) it can achieve a higher light transmittance than the prior art, there is another effect that can reduce the thickness of the conductive sheet (100).

In addition, the process of forming the expansion pattern 400 is easier than the process of forming the micro projections inside the conventional intaglio pattern 300 has another effect that can improve the productivity of the conductive sheet 100.

As shown in FIG. 2, the extended patterns 400 of the present invention are formed on both side surfaces 302 of the intaglio pattern 300, and the extended patterns 400 of each side are spaced apart from each other in the longitudinal direction of the intaglio pattern 300. Can be formed.

The separation distance can be easily adjusted the filling of the conductive paste (900). When the expansion patterns of each side are connected to each other in the longitudinal direction of the intaglio pattern 300, the corners of the acute angles are generated, and the corners of the acute angles may generate empty spaces in which the conductive paste 900 is not filled. It is preferable that the expansion patterns 400 of) have a predetermined separation distance.

In addition, as shown in FIG. 2, the expansion patterns 400 of the present invention may alternately form the expansion patterns 400 of the intaglio pattern side surfaces 302. The alternately formed means that the expansion pattern of the other side is disposed between the expansion patterns 400 of one side having the separation distance. When the expansion patterns 400 are alternately formed at both sides, the expansion patterns 400 may have a predetermined width in the longitudinal direction of the intaglio pattern 300, thereby having a certain electrical conductivity and resistance. The expansion pattern 400 of the alternating arrangement may have a width D of the intaglio pattern of 1 to 30 μm in order to prevent a rolling phenomenon of the conductive paste during squeeze filling.

As shown in FIGS. 3 and 4, the barrier rib pattern 500 or the micro protrusions 600 may be formed inside the intaglio pattern 300. The barrier rib pattern 500 or the micro protrusions 600 may prevent a phenomenon in which the conductive paste 900 is pushed out of the intaglio pattern 300 during squeeze filling.

In the present invention, the partition pattern 500 refers to a unit structure in which two structural shapes having different shapes are combined, and the micro-projections 600 mean a single structural shape. That is, as shown in (a) of FIG. 3, the partition wall pattern 500 may be a unit structure in which two structural shapes having different shapes, such as a spherical shape and a bar shape, are combined, and as shown in FIG. The protrusion 600 may have a single structural shape. The micro-projections 600 may be arranged in various shapes such as spherical, oval, bar (bar), polygon.

Shapes of the barrier rib pattern 500 and the minute protrusions 600 may vary according to the shape of the expansion pattern 400. As shown in Figures 3 and 4 it is preferable to include the shape of the same system as the shape of the expansion pattern 400. The same opening means that when the expansion pattern is a spherical or elliptical partial shape having a curvature, the partition pattern 500 and the microprotrusion 600 pattern also include a spherical or elliptical shape.

That is, in the case of the spherical or elliptic partial extension pattern 400 as shown in FIGS. 3A and 4A, the lattice pattern 500 is preferably a unit structure including a spherical or elliptical shape. In the case of the barrier rib pattern 500 of the same pattern as the expansion pattern 400, the width width is kept constant in the longitudinal direction of the intaglio pattern 300 to maintain a constant electrical conductivity and resistance, and also various patterns in terms of manufacturing the pattern It is more preferable because it can reduce the trouble of forming a shape.

3 (b) and 4 (b), like the logic of the lattice pattern 500, the shape of the micro-projections 600 of the same system as that of the expansion pattern 400 is also preferable. Do.

In addition, the barrier rib pattern 500 unit structure of the present invention may be formed with a predetermined distance in the longitudinal direction and the width direction of the intaglio pattern 300. As shown in (a) of FIG. 3, the unit structure of the barrier rib pattern 500 may be disposed at a predetermined distance in the longitudinal direction of the intaglio pattern 300, and as shown in FIG. It may be formed in the width direction. In this case, the unit structure length and the separation distance of the barrier rib pattern 500 may be adjusted in a range of improving electrical characteristics without a collapse of the barrier rib pattern 500 during squeeze filling.

In the present invention, the conductive paste 900 is filled in the intaglio pattern 300. As shown in FIG. 5, the conductive paste 900 may include two kinds of spherical metal particles having different diameters. Among the spherical metal particles, the conductive paste 900 may have a small diameter on the upper part of the larger spherical metal particles 701. Spherical metal particles 702 may be stacked. In the present invention, the two kinds of spherical metal particles include not only different kinds of material of the metal particles, but also spherical metal particles having different diameters with the same material.

As the spherical metal particles, various metal particles such as Ag, Cu, Ni, Al, Co, Cr, Mn, and composites thereof may be used, and the composite includes a core-shell structure. Preferably spherical particles of Ag can be used.

The diameter of the large spherical metal particles 701 may be 100 to 300nm, preferably 150 to 250nm. The diameter of the small diameter spherical metal particles 702 may be 20 to 80nm, preferably 30 to 60nm. In addition, the spherical metal particles 702 having a small diameter are preferably smaller than or equal to the size of pores between the spherical metal particles 701 having a large diameter. At this time, the spherical metal particles 702 having a small diameter may enter the spherical metal particles 701 having a large diameter to increase the density of the metal particles, thereby increasing the electrical conductivity.

As the spherical metal particles 702 having a small diameter are stacked on the upper part of the spherical metal particles 701 having a large diameter, as shown in FIG. 5, the spherical metal particles 701 having a large diameter are formed below the intaglio pattern 300. As the spherical particles 702 having a small diameter are formed on the upper portion thereof, as shown in FIG. 5, the spherical metal particles 702 having a small diameter penetrate into the pores of the spherical metal particles 701 having a large diameter. Can be formed. This lamination structure can be achieved in two filling processes. That is, in one filling, a paste containing spherical metal particles 701 having a large diameter may be filled, and a paste including spherical metal particles 702 having a small diameter may be filled in two layers to form a laminated structure. have.

The intaglio pattern 300 formed by the stacked structure has a higher density of metal particles, thereby improving electrical characteristics. Table 2 is an experimental example showing that the electrical properties are improved. The following experiment is an experimental result of conducting the conductive paste 900 having only the use example of metal particles in the intaglio pattern 300 having the same size as the spherical partial pattern extending pattern 400.

구분division	저항값Resistance
200nm의 Ag 구형 입자 사용Use of 200nm Ag spherical particles	146Ω146 yen
200nm의 Ag 구형 입자에 50nm의 Ag 구형입자를 혼합하여 사용50nm Ag spherical particles mixed with Ag 200 spherical particles	102Ω102Ω
200nm의 Ag 구형 입자의 상부에 50nm의 Ag 구형입자를 적층시켜 사용50nm Ag spherical particles stacked on top of 200nm Ag spherical particles	83.79Ω83.79Ω

As shown in [Table 2], the case of using two kinds of metal particles having different sizes than the case of using only one type of Ag spherical particles has a lower electrical resistance value, and the case of using two kinds of spherical particles having different sizes. It can be seen that the case of lamination has a lower resistance value.

Claims

Base layer;

Intaglio pattern implemented in the depth direction of the base layer;

It includes; conductive paste is filled in the intaglio pattern,

The intaglio pattern is,

A conductive sheet comprising expansion patterns recessed in the width direction of the base layer
The method according to claim 1,

The extension patterns are formed on both sides of the intaglio pattern, and the extension patterns on each side are formed to be spaced apart from each other.
The method according to claim 1,

The extension patterns are formed on both side surfaces of the intaglio pattern, and the extension patterns on both sides of the conductive sheet are alternately formed.
The method according to claim 1,

The expanded pattern is a conductive sheet, characterized in that the spherical or oval partial shape
The method according to claim 1,

A conductive sheet, characterized in that a plurality of partition patterns or minute projections are formed in the intaglio pattern
The method according to claim 5,

The expansion pattern is a spherical or oval partial shape,

The barrier rib pattern is a conductive sheet, characterized in that the unit structure in which spherical or oval shapes are combined with rod shapes.
The method according to claim 5,

A conductive sheet having a lower thickness of the substrate layer formed by the lower surface of the substrate layer and the lower surface of the intaglio pattern is 1 to 5 μm.
The method according to claim 1,

The conductive paste includes two kinds of spherical metal particles having different diameters,

A conductive sheet comprising a structure in which spherical metal particles having a small diameter are stacked on top of spherical metal particles having a large diameter among the spherical metal particles.