KR101170850B1 - conductive sheet - Google Patents

Abstract

The present invention relates to a sheet-type conductive material, specifically, a conductive material having electrical conductivity in all directions not only in the left and right directions of the sheet, but also in the vertical direction, and in particular, the high conductivity is dramatically improved in the vertical direction while further improving the shock absorption and flexibility. It relates to a sheet-type conductive material configured to have.

It may be used as a conductive material in electronic components or as a material for electromagnetic wave shielding materials.

To this end, it comprises a hole perforated in a flexible polymer sheet and a conductive layer formed on both sides of the hole and on both sides of the polymer sheet, and particularly the electrical conductivity of the side conductive layer formed on the side of the hole As a method to efficiently increase, the present invention provides a structure and a method for improving the step coverage of the deposited thin film, and improving both the adhesion, the wear resistance, and the efficiency of the thin film.

Sheet type conductive material, electromagnetic shielding, electrical conductivity

Description

Sheet-type conductive material {conductive sheet}

1; Substrate having a fully perforated hole and a conductive material having a deposition layer formed thereon

2; A substrate further comprising a separate protrusion and depression on the one of FIG. 1 and a conductive material having a deposition layer formed thereon

3; A substrate having a deposition layer formed thereon and a substrate formed of a substrate having a hole formed on the upper surface and the lower surface of the substrate so as to protrude upward or recess below the surface.

4; Substrate formed in such a manner that a portion of the cross-section of the hole is in the oblique direction with respect to the upper surface and the lower surface and the conductive material having a deposition layer formed thereon

5; The conductive material in which the evaporation layer was formed on the base material formed in both the upper surface and the lower surface of the protrusion 27 in FIG.

6; Substrate formed in the oblique direction in which the cross-sectional structure of the perforation hole in both the upper and lower surfaces is smooth

Figure 7; Substrate further formed with depressions on the one of FIG.

Fig. 8 Deposition on a substrate with a narrow width of perforation hole

Figure 9; A figure that improves step coverage by lifting up a part of the substrate with a narrow perforated hole

Figure 10; Illustration of improving step coverage by staggering two parts of the substrate with a narrow perforated hole up and down

Figure 11; 9 and 10 are formed by forming a punched hole while leaving a part of the drilled hole attached to the substrate by a cutting line forming method.

Figure 12; AA sectional view of FIG.

Figure 13; Figure of lifting up and down each part of Figure 12

14; 12 and 13 illustrate another method

1; flexible polymer sheet 3; Fully perforated holes 5; Deposited (pvd) thin film 7; Protrusion 9; Depression 11; Section 13 of the hole drilled in a direction perpendicular to the upper surface of the substrate; Cross-sections of holes drilled obliquely to the bottom surface of the substrate, which may be a cross-section of the holes or may be formed by deformation of the substrate 15, 19; The minimum width of the drilled hole (diameter) 17; the maximum width of the drilled hole (diameter) 51; Surface conductive layer 53; Side conductive layer 71; Leaf 73 which is raised upward and coated; Leaf 101 lowered to the bottom and coated; Top sputtering source 103; Bottom sputtering source 105; Coating material traveling from source to substrate during coating

The present invention relates to a sheet-type 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 the adverse effect 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 deposition materials collide with other molecules increases, the amount of scattering increases, thus increasing the amount of materials deposited on the inner wall of the vacuum chamber rather than being coated on the substrate to be coated, thus causing expensive deposition materials. 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. That is, to provide a sheet-type conductive material that can save coating materials, improve adhesion, increase electrical conductivity and density, and prevent degradation and destruction of durability and electrical conductivity characteristics.

It is still another object of the present invention to provide a sheet-type conductive material having both a conductive material having improved durability and wear resistance and a function of absorbing and blocking electromagnetic waves.

The present invention provides very good step coverage even at reduced vacuum levels (ie, the degree of vacuum in which the physical vapor deposition process is carried out) and at higher vacuum ranges or at higher vacuum ranges where conventional physical vapor deposition is carried out. By forming the shape of the conductive material base material in the following configuration so as to obtain it, it was to solve all the above-mentioned problems caused when reducing the average free stroke (to obtain a good step coverage).

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. And a conductive layer for connecting the upper and lower surface conductive layers electrically connected to each other in a state formed in the boring hole (or the cutting slit), respectively, on the upper and lower surfaces of the substrate. In the sheet-type conductive material having a conduction function in all directions up, down, left, and right and to improve step coverage for the connection conductive layer thin film, the surface resistance ratio between the surface conductive layer and the connection conductive layer (surface conduction) Sheet resistance of the layer / sheet resistance of the connecting conductive layer) is at least 0.02 or more (thickness ratio of the surface conductive layer thin film / thickness of the connecting conductive layer thin film) 50 or less, and the conductive layer is a metal (alloy) thin film having a thickness of 20 nanometers or more and 5 microns or less formed by a physical vapor deposition method, and the conductive layer thin film formed per unit area of the conductive material. The horizontal cross-sectional area is at least 20 μm ² / cm ² or more, and the normal of the surface of the connection layer to be coated in the hole (or slit) at the beginning of the step of depositing the connection layer, in particular by physical vapor deposition (at least). Some (vertical lines erected from a point on the surface of the connecting layer) form a diagonal line with the upper / lower surface or (or) the depth (d or height h) of the hole (or slit) shall be stated in the specification. ) Up and down electrical conductivity, durability, and economics, characterized in that it satisfies at least one of the shape that the ratio of the width (or diameter) is 10 (depth / width) or less. The sheet-like conductive material is provided. In order to improve step coverage, the sheet resistance ratio is set to 0.02 or more and the thin film thickness ratio is set to 50 or less in order to prevent waste of the coating material while preventing excessive thickness of the upper and lower surface conductive layers. This is to improve the durability by solving the imbalance of the thin film structure due to excessive thickness variation. The reason for limiting the thickness of the conductive layer to 20 nanometers or more and 5 microns or less is that the conductive function is lost in the case of 20 nanometers or less, and the stress of the thin film itself becomes excessive in the case of 5 microns or more. This is because it not only deforms the shape but also causes desorption. In addition, the reason why the horizontal cross-sectional area of the connection conductive layer thin film formed per unit area of the conductive material is at least 20 μm ² / cm ² or more is less than that, so that the electrical resistance in the vertical direction is too large to lose meaning as the vertical / lower conductive material. Because it becomes. In particular, at the beginning of the step of depositing the connection conductive layer by a physical vapor deposition method, a normal (vertical line erected from a point on the surface of the connection conductive layer) of a part of the surface of the connection conductive layer to be coated on the hole (or slit) is formed. It is a shape that forms a diagonal line with the lower surface and / or the ratio of the depth (d or height h) of the hole (or slit) to the width (or diameter) is 10 (depth / width). The reason for satisfying one or more of the following shapes is that very good step coverage can be obtained even by performing the physical vapor deposition process of the connection conductive layer in a high vacuum atmosphere having a large average free stroke. That is, to solve the above-mentioned problems occurring when the connection conductive layer is deposited in a low vacuum atmosphere in order to improve the step coverage by reducing the average free stroke. For example, when the connection conductive layer to be coated on the hole, that is, the normals of all inner surfaces of the hole are parallel to the upper / lower surface and the depth / width ratio is 10 or more, This is because a good connection conductive film under the above conditions cannot be deposited by the physical vapor deposition method. The key to improving step coverage is the surface parallel to the direction of the coating material proceeding from the coating source to the coating substrate during the coating process, that is, the side of the punched hole formed in the conductive substrate (where the connection conductive layer is to be formed). 'Will you allow more coating material to be deposited'? The most efficient method is not to configure the side of the hole to be parallel to the coating material traveling direction 105 as shown in Figure 8, as shown in Figures 4, 6, 9, 10, 13 It is a method of forming in a form facing diagonally. In the case where the coating material meets the direction perpendicular to the traveling direction 105, the most desirable amount of coating material is deposited, but since it is impossible in reality, the form facing diagonally is preferable. In addition, as the width w of the hole is closer to zero, the thickness of the coating material deposited on the side thereof is also closer to zero, resulting in the worst case step coverage. What is important here is that the ratio of the depth / width of the drilling hole is more important than the width (w) of the drilling hole itself. The smaller the ratio of depth / width, the better step coverage can be realized, and most preferably, the ratio of depth / width is small, and the normal (connection) of a part of the surface of the connection conductive layer to be coated on the hole (or slit). It would be more desirable if the vertical lines erected from a point on the surface of the conductive layer were configured to form a diagonal line with the upper and lower surfaces. 9, 10, and 13, the cutting leaf (cutting leaf) made by the cutting slit (cutting leaf) made up aside or down, the width of the above-mentioned hole can be seen indefinitely. In other words, as the depth / width ratio approaches zero, step coverage is greatly improved. When the connection conductive layer thin film having the improved step coverage is formed by such a configuration, the electrical conductivity in the up / down direction, which is the original purpose, is greatly improved, and the selection of the physical deposition process is expanded, which is more advantageous and more productive. Since the process can be used and the deposition process can be performed in a higher high vacuum region, it is possible to minimize the deposited materials that are scattered and wasted, thereby saving expensive deposition materials. Furthermore, since the deposition is performed in a high vacuum atmosphere, the purity of the thin film itself is improved to prevent alteration, and the adhesion and thin film density are improved, thereby improving durability and wear resistance reliability. In addition, the reason for attaching the temporal clue 'at the time when the step of depositing the connection conductive layer by the physical physical deposition method (at least) starts' is that the conduction during or during the deposition or after the completion of the deposition is performed. This is because the shape of the material substrate may be deformed and / or contracted by a rise in temperature to be different from the above conditions, and there is a possibility of artificially changing the shape of the conductive material after the deposition is completed, thereby avoiding the aspect of the present invention. It is important to improve the step coverage because the shape of the hole is important at the start of the deposition process and at the time of the deposition process, 'at the time when the step of depositing the connection conductive layer by the physical deposition method (at least) begins'. Is attached to the clue.

The sheet-type conductive material according to the present invention is very excellent in electrical conductivity in all directions up, down, left and right, and provides an omnidirectional conductive material which is superior to the conductive material according to any prior art. However, there is still a disappointment. It is durable and wear resistant. In particular, the conductive material having a structure as shown in Figs. 1, 3, 4 and 5 is very vulnerable to scratches on the surface. When friction is applied to the surface of the sheet-like conductive material of the above structure, very thin films are separated from each other where the upper / lower surface conductive layer and the connecting conductive layer are bonded to each other (for example, as shown in 27), and the bonding between them is performed. It is cut off. As such, if the connection conductive layer loses the electrical connection function between the upper and lower surface conductive layers, the connection conductive layer loses its meaning as a vertical conductive material in all directions.

In another aspect of the present invention, a protrusion protruding from a surface on at least one of the upper and lower surfaces, and the top of the protrusion to reinforce the above weakness to provide a conductive material having improved durability, wear resistance, and reliability. There is a 'safe' connection conductive layer at a height lower than the highest portion (upper / lower surface side of the protrusion), and the horizontal cross-sectional area of the connection conductive layer thin film averages 20 µm ² / per unit area of the conductive material. Sheet type conductive material is provided, characterized in that the cm ² or more. The reason for the protrusion is to protect the upper / lower surface conductive layer from friction, and the reason for placing the 'safe' connection conductive layer lower than the protrusion is that some of the upper / lower surface conductive layers are damaged by friction. Even if this is the case, the connection layer, which plays a crucial role and function, is to be protected. The reason why the word 'safe' is added before the connection layer is to distinguish it from the connection layer that is exposed to the top of the protrusion or the outermost surface (ie, exposed to friction). In addition, the horizontal cross-sectional area of the connection conductive layer thin film formed per unit area of the conductive material is at least 20 μm ² / cm ² or more because the electric resistance in the vertical direction is too large to lose the meaning as the conductive material.

In order to provide a similar conductive material, as in another embodiment of the present invention, the recessed portion is recessed from the surface on at least one of the upper and lower surfaces, and the portion recessed in the thickness center direction than the outermost surface (the surface In the above, there is provided a 'safe' connection conductive layer in the center portion of the thickness, and the horizontal cross-sectional area of the connection conductive layer thin film is 20 µm ² / cm ² or more per unit area of the conductive material. . The reason for placing the 'safe' connection conductive layer in a portion recessed in the thickness center direction of the outermost surface with the recessed portion is to protect the connection conductive layer thin film from friction. The reason why the horizontal cross-sectional area of the connection conductive layer thin film formed per unit area of the conductive material is at least 20 μm ² / cm ² or more is because if the electric resistance in the vertical direction is too large, it loses its meaning as a conductive material.

The conductive material may be provided by incorporating various additional functions in order to improve the product to a more versatile function. As an example, as in another embodiment of the present invention, a sheet-type conductive material may be provided, wherein the base material of the conductive material includes at least one selected from electromagnetic wave absorbers, thermal conductors, and far-infrared radiators. In addition, the sheet-type conductive material may be provided by further comprising a (conductive) adhesive layer on at least one surface of the sheet-type conductive material. Aspects included in the specification or drawings of the present invention has been shown an embodiment thereof, in addition to the sheet-type conductive material of various aspects may be provided based on the technical spirit of the present invention.

Sheet-type conductive material according to the present invention can be used as an electromagnetic shielding film, film, sheet or gasket or cushioning material and can be used as a material for electronic products that require a conductive function in all directions up, down, left and right, and is cheaper and more economical. The method may provide a sheet-type conductive material having more various functions and improved reliability, thereby replacing expensive conductive foam materials, conductive fabrics, and conductive nonwoven fabrics.

Claims (5)

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. Power supply function in all directions of up, down, left and right, including a trademark conductive layer, a lower conductive layer, and a connection conductive layer electrically connecting the trademark conductive layer and the lower surface conductive layer to each other in a state formed in the perforation hole or the cutting slit. In the sheet-type conductive material having a step and improve the step coverage of the connection conductive layer thin film, the surface resistance ratio of the surface conductive layer and the connection conductive layer (surface resistance of the surface conductive layer / sheet resistance of the connection conductive layer) ) Is at least 0.02 and the ratio of the surface conductive layer thin film thickness to the connection conductive film thin film thickness (thickness of the surface conductive layer film / thickness of the connection conductive film thin film) ) Is 50 or less, and the conductive layer is a metal or metal alloy thin film having a thickness of 20 nanometers or more and 5 microns or less formed by physical vapor deposition, and the connection conductive layer formed per unit area of the conductive material. The horizontal cross-sectional area of the thin film is at least 20 ² / cm ² and the normal to the surface of the connection layer to be coated on the hole or slit at the beginning of the step of depositing the connection layer by physical vapor deposition (connection layer surface One of a shape in which a portion of the vertical line formed from one point of the line forms a diagonal line with the trademark surface and the lower surface, or a shape in which the ratio (depth / width) of the hole or slit is 10 or less. Sheet type conductive material characterized by satisfying the above delete delete delete delete

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