KR20070081395A - Conductive complex - Google Patents

Abstract

A conductive complex comprising conductive layers on the both sides of a flexible polymer sheet is provided to have improved conductive rate in top and bottom directions together with high impact absorptivity and flexibility, and to reduce consumption of conductive resin considerably by fabricating the conductive layers and forming a physical vapor deposition thin film on the surface conductive layer among the conductive layers and a dent concave part in center of the thin film. A conductive complex includes: a sheet substrate(1) made of flexible polymer; a hole or cutting slit(7) formed at a position of the substrate; top and bottom surface conductive layers that are formed on top and bottom of the substrate; and a connection conductive layer(12) that interconnects the top and bottom surface conductive layers. The connection conductive layer has conductive resin. One side of the surface conductive layer comprises a thin film formed by physical vapor deposition and the thin film includes a dent concave part toward inner side of the hole or cutting slit. A part of the conductive resin is electrically connected to the surface of the dent part.

Description

Conductive Complex

Fig. 1: Formation of perforation holes to have an ovoid cross section at a designated place of a sheet-like substrate made of a flexible polymer

Fig. 2 Formation of perforation holes to have a rectangular cross section at a designated place of sheet-like substrate made of flexible polymer

Fig. 3; Forming a surface conductive layer by vapor deposition on both surfaces of the substrate of Figure 1 and forming a connection conductive layer made of a conductive resin on a portion of the inner surface of the punched hole

Fig. 4; Forming a surface conductive layer by vapor deposition on both surfaces of the substrate of FIG. 2 and forming a connection conductive layer by various methods using the inner surface of the perforated hole.

Fig. 5; Forming a surface conductive layer by vapor deposition on both surfaces of the substrate of Fig. 2 and forming a connection conductive layer as a whole together with the surface using the inner surface of the perforated hole.

Figure 6; the projection formed in a part of the upper / lower surface in Figure 3

1; flexible polymer substrate 3; long hole perforation 5; square hole 7, 7, 9 ;; evaporation thin film 11; conductive resin connection conductive layer formed on a portion of the inner surface of the hole

12; hole 13 remaining after the connection conductive layer 11 is formed; conductive resin connection conductive layer 15 formed only by the thickness of the hole hole; conductive resin connection conductive layer 17 formed to cover the periphery thin film of the hole exceeding the hole hole thickness; 17; connection layer 15 Hole 19 remaining after formation; hole 21 remaining after connection conductive layer 13 is formed; conductive resin conductive layer 23 formed so as to cover the entire deposition thin film layer on the inner and upper and lower surfaces of the hole; projections protruding from the surface

The present invention relates to a composite conductive material used as an electronic component or material. In recent years, electronic products have tended to have various components integrated in a small space according to the trend of light and short. Especially when there is a high frequency oscillation circuit and when a high frequency signal processing lead is arranged, absorption shielding of electromagnetic waves becomes an essential factor. For example, in the case of a mobile phone or a flat panel display device, high frequency interference between electronic components should be prevented and emission to the outside should also be thoroughly prevented.

In order to accomplish this task, an electromagnetic wave absorber or an electromagnetic wave shielding material according to a known technique is often developed and used. As the most common form of such a component, a conductive fabric and electromagnetic gaskets using the same are commercially available.

However, the conductive fabric and the electromagnetic gasket using the same have a problem that the manufacturing method is complicated and the product shape is extremely limited in the shape of the product and the production cost is expensive, and the product is made of a very thin gasket or a minute shape product. It is true that it is very difficult.

In order to solve some of these problems, namely, the unit price problem, US Patent 6,541,698 granted to Stanley R, forms a thin film by dry deposition on one side of a thin film having a myriad of very fine protrusions. By manufacturing the electromagnetic gasket according to the known technology using the proposed method to lower the production cost than the product by the conductive fabric. However, this is a simple coating on the cross section of the film by physical vapor deposition (pvd) method, and because it is not energized at all in the vertical direction of the cross section of the film, it gives only two-dimensional conductivity, so the production cost is low, but the ease of manufacture or the variety of products Esau still has limitations.

In particular, in the case of a gasket manufactured using a conductive fabric (nonwoven fabric) according to the known art, many processes and production machines are required to produce a specific shape. In order to solve this problem, it is possible to conduct electricity in all directions of up, down, left, and right, and to propose conductive materials having a constant thickness and a method of simply cutting them into a desired shape. In Korean Patent No. 10-0471194, which can be considered as an invention that realizes this, the sponge material is provided as a conductive sheet that can be provided with a metal layer by an electroless plating method and can be energized in up, down, left and right directions. However, in the case of this product, a plating process causing serious pollution is involved, and furthermore, the elasticity of the product and very complicated and low productivity are a big problem.

In another invention, Korean Patent 10-0478830 proposes a method of making a conductive sheet that can be energized up and down by making a plurality of holes in a foamed resin sheet and coating it with a conductive resin and drying it. Price and energy efficiency, such as product cost, remain, which is a problem that prevents the popularization of this product.

In addition, there are various inventions and proposals, but there is no configuration that solves the problems of the prior arts. Therefore, there is still a need for the development of a conductive material having no pollution problem, low production cost, flexibility and elasticity, and improved reliability of up, down, left and right conduction.

In order to solve this problem, a synthetic sheet having a plurality of perforations or cutting slits (hereinafter referred to as holes) is prepared in a flexible sheet, and the upper and lower surfaces of the sheet and the upper and lower surfaces are formed. The upper and lower surface conductive layers and the connection conductive layers are uniformly coated on the sides of the perforated holes by physical vapor deposition, thereby providing a connection conductive layer evenly coated on the sides of the holes to electrically connect the surface conductive layers coated on the upper and lower surfaces. Upper and lower surface conductive layers are electrically connected to each other; A conductive material having a conduction function in all directions of up, down, left and right and a coating method thereof may be proposed.

But these products also have serious problems by default. That is, some of the phenomena caused by the limitations of the physical vapor deposition method, the most significant of which is the poor step coverage (phenomena) of the biggest problem of the physical vapor deposition method. Physical vapor deposition is different from resin coating by electroless plating or deeping method, but it is well coated on the side facing the coating source, but on the side or back side not facing each other. It is difficult to make. Of these problems, the coating on the back side can be solved by placing additional coating sources on the corresponding back side. However, the method of coating on the inner side of narrow and deep drill holes still remains a major problem barrier. As such, the thickness ratio of the thin film deposited on the side and side facing the coating source is called step coverage. The closer the thickness ratio is to 100%, the better the step coverage. To improve step coverage, the average degree of freedom of gases and vapors in the interior is reduced by lowering the degree of vacuum (close to atmospheric pressure) in the vacuum chamber (regardless of the type of physical deposition method) that performs the physical deposition. It is essential to shorten the mean free path or to apply a bias voltage to the substrate itself. However, in most cases, the substrate to be coated is a non-conductor supplied continuously. Therefore, the bias voltage application method should be used, except that it is impossible to realize, and a method of making the average free stroke short. However, through the in-depth analysis of the results of repeated experiments carried out by the inventors and known research reports, the following defects were found. In other words, this method can evenly coat the inner side of the narrow and deep drill hole, but it encounters a large barrier due to various quality problems described below. As described above, when the coating is performed in such a way as to reduce the average free stroke, the deposition material starting from the coating source is more likely to collide with other gases (or vapors) while flying at a certain path. In other words, the possibility of mixing with other substances or compounding with active molecules increases a lot of adverse effects on the purity. The form of the above-mentioned compound is mainly in the form of oxidation or nitriding. This results in the inclusion of the metal oxide or metal nitride as impurities in the metal thin film layer. That is, the electrical conductivity of the metal conductive layer is reduced. In addition, as a result of the incorporation of the impurities (mainly dielectric), the thin film follows the characteristics of the dielectric, and exhibits a low strength and a brittle characteristic. In addition, as the deposition material collides with other gases, a considerable amount of kinetic energy is lost, so that the adhesion and the film density of the physically deposited thin film on the coated substrate are inevitably deteriorated. That is, not only fragile, but also desorption occurs from the substrate to be coated or the thin film itself loses its continuity, resulting in a fatal defect as a conductive material. In addition, as the number of depositing materials collides with other molecules increases, the amount of scattering increases, thus increasing the amount of materials deposited on the inner wall of the vacuum chamber without being coated on the substrate to be coated. Naturally, the coating speed is lowered and the production cost is increased. As mentioned above, it was concluded that if the step coverage was improved by the general method, that is, the method of reducing the average free stroke, it would not be very helpful in solving the present problem.

An object of the present invention is to completely solve all the above problems and to provide a highly reliable conductive material. In other words, it is possible to significantly lower the product cost by increasing productivity, to provide a high conductivity, and to provide a composite conductive material having improved durability and reliability.

Still another object of the present invention is to provide a conductive material having improved durability and wear resistance, and a hybrid conductive material having both a function of absorbing and blocking electromagnetic waves.

Still another object of the present invention is to provide a composite conductive material that can be used as a planar heating element.

The present invention solves all the problems and irrationalities of the above-described proposed techniques through a unique configuration specially proposed for realizing the present invention in the substrate and the conductive layer of the composite conductive material.

To this end, a first aspect of the present invention provides a sheet-like substrate made of a flexible polymer material, a perforation hole or a cutting slit formed at a designated position of the sheet-like substrate. Including a trademark conductive layer and the lower surface conductive layer formed on the upper and lower surfaces of the substrate, respectively, and a connection conductive layer for electrically connecting the upper and lower surface conductive layers to each other in a state formed in the drilling hole (or cutting slit). In a composite conductive material having a conduction function in all directions up, down, left, and right, the connection conductive layer is formed of at least a conductive resin, and at least one surface of the surface conductive layer is formed by physical vapor deposition. And a thin film, wherein the deposited thin film is formed into at least the perforated hole (or cutting slit; It includes the deposited thin film of the type recessed toward the inner surface (from the substrate surface to the center of the substrate thickness), the conductive resin of the connection conductive layer is essentially a part of the surface of the deposited film There is provided a composite conductive material characterized by a configuration which is present in an electrically connected state. The reason why the conductive resin is included in the connection conductive layer is that the upper and lower surface conductive layers may be reinforced and / or electrically disconnected from the inner surface of the hole. The method of making the electrical connection firm and secure, and the reason why the surface conductive layer includes a deposited thin film formed by physical vapor deposition is a means for significantly reducing the consumption of conductive resins for the formation of expensive surface conductive layers. In addition, the deposition thin film is formed to include at least the deposition thin film of the type recessed toward the inner surface of the perforation hole (from the substrate surface to the center direction of the substrate thickness) (electrically connecting the upper and lower surface conductive layers, Or it is used to reinforce the connection, a method for significantly reducing the amount of the conductive resin included in the connection conductive layer. With such a shape, the connection conductive layer can provide sufficient electrical conductivity even if only the thickness of the perforated hole is coated, and as shown in FIG. 3 and FIG. 6, it is not necessary to apply the entire thickness of the perforated hole 3 as shown in FIG. Since the deposited thin film recessed from the surface toward the center of thickness of the substrate may be applied only to the center portions of the thickness where the conductive thin films meet each other, the consumption of the conductive resin can be greatly reduced. In spite of this local connection, it is not connected to the thin thickness side of the deposited thin film, but is connected to the surface of a considerable area of the thin film so that sufficient electrical connection is made, so that the electrical conductivity of this part is very excellent. In addition, in such a structure, the conductive resin is not coated, but the surface portion coated with only a deposition thin film exhibits almost the same shock absorption and flexibility as the substrate itself. That is, when the substrate is made of a foamed resin sheet which is very soft and flexible and excellent in shock absorption, it is possible to provide a composite conductive material having a surface that retains its own physical properties. In the embodiment without the depression deposited thin film 10 as in the configuration of the present invention, as shown in FIG. 4, 15, or 21 in FIG. . This leads to a waste of expensive conductive resins, resulting in an increase in product cost. If the conductive resin is applied to the punched hole as 13 to save the conductive resin, satisfactory electrical connection is not established between the upper and lower surface conductive layers. This is because the contact surface between the thin film conductive layer 9 and the connection conductive layer 13 including the conductive resin cannot exceed the thickness range of the thin film conductive layer 9. In this way, if the contact occurs only in the thin film thickness range, as well as poor contact or detachment of the thin film at the contact portion easily occurs. Therefore, in order to provide a sufficient contact area between the thin film conductive layer 9 and the connecting conductive layer, it is essential that at least a substantial area around the hole is coated with a conductive resin as shown in FIGS. 4 and 5. This is not only an increase in manufacturing cost but also a factor that causes a great loss in the elasticity, flexibility and shock absorption of the composite conductive material.

In the same configuration as the first embodiment of the present invention, that is, at least the connection conductive layer comprises a conductive resin, even if the upper and lower surface conductive layers are separated from each other, the object of the present invention is assisted by the conductive resin. Can be achieved. Therefore, a configuration that can significantly increase the productivity in the physical deposition step in which the unit cost specific gravity is largely proposed in the following aspects. That is, in the composite conductive material having the first aspect of the present invention, a structure in which a synthetic resin film is inserted between the surface conductive layer and the substrate by further including a flexible resin film on at least one of upper and lower surfaces of the substrate. It is a composite conductive material characterized by In most cases, the substrate has a thickness in mm. In order to efficiently perform the physical vapor deposition process, the substrate is wound in a web form and loaded into a vacuum container to make the inside of the vacuum container into a vacuum atmosphere, and then perform the physical vapor deposition process. (Here, the physical vapor deposition process and the vacuum web coating process of winding the long substrate in the form of a web and depositing it in a vacuum container are well known by a known technique and are commonly used techniques, and thus detailed description thereof will be omitted.) The time is so long that the length of substrate that can be loaded per batch is directly related to productivity. Here, the thinner the thickness of the substrate, the more wound the substrate can be put in a limited space. However, the substrate has a very limited selection area in consideration of impact absorption and elasticity. Therefore, rather than putting the substrate directly into the vacuum vessel, a synthetic resin film that is much thinner (and thus much longer in length) than the thickness of the substrate can be deposited on a longer length film in one batch. After the physical thin film deposition process was performed on the surface thereof, the synthetic resin film having the deposited thin film obtained as the result was laminated on at least one side of the substrate. The same result as that of forming the physical deposited thin film on the substrate was obtained. It can be realized and this method can contribute greatly to the cost reduction.

In addition, in the present invention, the coating thin film layer may be further coated with a conductive resin to form a composite conductive material having improved electrical conductivity. This will be determined in consideration of economics according to the characteristics of each product, but the conductive resin layer further formed on the surface of the deposited thin film layer may serve to protect the deposited thin film layer to some extent from frictional force.

In order to make the composite conductive material of the present invention into a product having more various functions, the following conductive materials are provided.

That is, the substrate is provided with a composite conductive material, characterized in that it comprises one or more selected from the electromagnetic wave absorber, thermal conductor, far-infrared radiation. Also provided is a composite conductive material characterized by a structure in which the (conductive) adhesive layer is further added to at least one side. Such a structure will help to more easily apply the conductive material to a specific required place.

In addition, a composite conductive material is provided that includes a protrusion 23 protruding from the surface on at least one of the upper and lower surfaces as a structure that greatly improves wear resistance. This configuration serves to primarily protect the upper and lower surface conductive layers when the conductive material causes friction with other surfaces.

The composite conductive material of the present invention may be used as a planar heating element. In this aspect, the conductive material is provided with a composite conductive material, characterized in that the resistivity of the conductive resin contained in the connection conductive layer is at least twice as large as that of the surface conductive layer for use as a surface heating element.

In addition, when the composite conductive material of the present invention is used as a planar heating element, the composite conductive material is used to prevent the magnetic fields generated naturally due to the flow of current to each other to prevent the magnetic field offset or the electrical conductivity of the conductive material. For the purpose of improvement) there is provided a composite conductive material, characterized in that the conductive material is laminated in an even number of two or more sheets. In the case of magnetic field offsetting purpose, the purpose of preventing the magnetic field may be realized by using wires in which current directions flowing in the connection conductive layers of even layers existing in the cross-section of the laminated conductive material are balanced with each other and flow in opposite directions. Aspects included in the specification or drawings of the present invention have been shown the embodiments thereof, in addition to this, the composite conductive material of various aspects may be provided based on the technical spirit of the present invention.

The composite conductive material according to the present invention can be used as an electromagnetic shielding film, film, sheet or gasket or cushioning material and is a material of an electronic product that requires a conductive function in all directions up, down, left and right, or a planar heating element (preventing magnetic field generation). It can be used as a cheaper, more economical way to provide a more versatile and improved reliability of the composite conductive material to replace the expensive conductive foaming material or conductive fabrics and conductive non-woven fabrics in particular planar heating element.

Claims (7)

A sheet-shaped substrate made of a flexible polymer material, a perforation hole or cutting slit formed at a designated position of the sheet-shaped substrate, and formed entirely on the upper and lower surfaces of the substrate, respectively. It has a conduction function in all directions of up, down, left and right, including a trademark conductive layer, a lower surface conductive layer, and a connection conductive layer that electrically connects the upper and lower surface conductive layers to each other while being formed in the perforated hole (or cutting slit). In the composite conductive material having, the connection conductive layer comprises at least a conductive resin, at least one surface of the surface conductive layer comprises a thin film formed by physical vapor deposition (physical vapor deposition) The deposited thin film is at least toward the inner side surface of the perforated hole (or cutting slit; hereinafter referred to as hole). And a deposited thin film in the center direction of the substrate thickness from the surface, and the conductive resin of the connection conductive layer is partially present in an electrically connected state on the surface of the deposited thin film. Composite conductive material characterized by its configuration The composite conductive material of claim 1, further comprising a flexible resin film on at least one of upper and lower surfaces of the substrate, wherein a synthetic resin film is inserted between the surface conductive layer and the substrate. The composite conductive material of claim 1, wherein the substrate comprises at least one selected from an electromagnetic wave absorber, a thermal conductor, and a far infrared ray radiator. The composite conductive material of claim 1, wherein the (conductive) adhesive layer is a structure additionally added to at least one surface of the conductive material. The composite conductive material of claim 1, wherein the at least one of the upper and lower surfaces includes a protrusion protruding from the surface. The composite conductive material of claim 1, wherein the conductive material has at least twice the specific resistance of the conductive resin included in the connection conductive layer for use as a surface heating element, compared to the specific resistance of the surface conductive layer. The composite conductive material according to claim 1, wherein the conductive material is formed by stacking two or more of the conductive materials (for the purpose of canceling the magnetic field of the surface heating element or improving the electrical conductivity of the conductive material).

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