JPWO2011043367A1 - Conductive thin film structure and method for producing conductive thin film structure - Google Patents

Abstract

Provided is a conductive thin film structure having better quality than before. A conductive thin film structure 5 comprising a substrate 1, a fine wire structure 2 formed on the substrate 1, and a transparent electrode 3 formed on the substrate 1 so as to cover the fine wire structure 2. The thin wire structure 2 and the transparent electrode 3 are formed continuously by performing gravure offset printing on the substrate 1 using the gravure rolls 21 and 31 and the offset rolls 22 and 32, and the offset rolls 22 and 32. Is covered with blanket materials 22a and 32a.

Description

The present invention relates to a conductive thin film structure including a substrate, a thin wire structure formed on the substrate, and a transparent electrode formed on the substrate so as to cover the thin wire structure, and the conductive thin film structure The present invention relates to a method for manufacturing a body.

In recent years, photovoltaic power generation systems that use solar cell panels to supply power have begun to spread. In particular, with the recent increase in environmental awareness and the promotion of the government subsidy system, the demand for solar power generation systems is expected to increase both for general household use and for industrial use.

In recent years, many touch panels have been used as input devices for electronic devices such as bank ATMs, portable information terminals, car navigation systems, and multifunction devices. The touch panel is a device that performs an operation according to an image displayed on the screen, and is widely used as an input device that can be easily understood by elderly people. The demand for touch panels is expected to increase in the future. The touch panel is used in combination with a display device such as a liquid crystal panel or an organic EL panel.

By the way, in a solar cell panel, a transparent electrode is used in order to efficiently apply sunlight to a semiconductor substrate that generates electrons. For the transparent electrode, for example, an indium oxide film (ITO) doped with tin is used. Also in a touch panel, a liquid crystal panel, an organic EL panel, and the like (hereinafter sometimes abbreviated as a touch panel), a transparent electrode similar to a solar cell is used to show an image on the display to the operator. Therefore, in a solar cell panel, a touch panel, etc., it is desired to increase the transparency (light transmittance) of the transparent electrode as much as possible. On the other hand, if a sufficiently low resistance value is to be realized in a solar cell panel, a touch panel, or the like, the film thickness of the transparent electrode must be increased. In this case, the light transmittance is reduced and the raw material cost is increased. For this reason, the technique which makes high light transmittance and low resistance value compatible is indispensable for the transparent electrode used for a solar cell panel, a touch panel, etc.

In this regard, as a conventional technique, when a transparent conductive thin film is formed on a substrate, an auxiliary electrode having a low resistance value is provided between the two (for example, see Patent Document 1).

In the solar cell electrode of Patent Document 1, an auxiliary electrode is formed on the substrate by a sputtering method in order to reduce the resistance value of the entire solar cell electrode. Here, the auxiliary electrode is formed in a mesh shape so as not to impair the transparency of the transparent conductive thin film formed in the subsequent step. Note that the same sputtering method as that for the auxiliary electrode is performed on the transparent conductive thin film formed in the subsequent step.

JP 2004-296669 A

However, as in Patent Document 1, when the mesh auxiliary electrode is formed by using the sputtering method, the substrate is subjected to a mask process according to the mesh shape in advance, or an etching process according to the mesh shape after the sputtering. It is necessary to do. For this reason, it is difficult to manufacture the electrode for solar cells efficiently. Further, as in Patent Document 1, when the auxiliary electrode and the transparent conductive thin film are formed on the substrate by sputtering, in order to obtain alignment accuracy between the substrate and the auxiliary electrode and the transparent conductive thin film, mask processing and The etching process needs to be performed precisely and requires skill.

Furthermore, the sputtering method is a method in which argon ions collide with the target electrode material under reduced pressure, and the electrode material blown off by the impact adheres to the substrate to form a film. Then, the types of applicable substrates are limited. In order to perform the sputtering method, a large-scale apparatus such as an argon gas supply source, a high-voltage power source, a vacuum chamber, a vacuum pump, or the like is required. Therefore, the burden of equipment cost and maintenance cost is large.

Thus, at present, a conductive thin film structure that can be manufactured efficiently and at low cost while maintaining good alignment accuracy between the substrate, the auxiliary electrode, and the transparent conductive thin film has not yet been developed. The present invention has been made in view of the above problems, and an object of the present invention is to provide a conductive thin film structure having better quality than before. Another object of the present invention is to provide a method for producing a conductive thin film structure that can be carried out more efficiently and at a lower cost than in the past.

In order to solve the above problems, the conductive thin film structure according to the present invention is characterized by a substrate, a fine wire structure formed on the substrate, and a thin wire structure formed on the substrate so as to cover the fine wire structure. A transparent thin-film structure, wherein the fine wire structure and the transparent electrode are continuously formed by performing gravure offset printing on the substrate using a gravure roll and an offset roll. The offset roll has a surface covered with a blanket material.

As explained in the section of the background art, since the conventional conductive thin film structure is manufactured by sputtering, it is difficult to manufacture efficiently, and the substrate, thin wire structure (auxiliary electrode) and transparent It was difficult to achieve alignment accuracy with the electrode (transparent conductive thin film). Moreover, since the kind of board | substrate is limited and a large-scale installation is required, it has become a cause of high cost.
In this regard, in the conductive thin film structure of this configuration, gravure offset printing is performed using an offset roll whose surface is covered with a gravure roll and a blanket material, and the fine line structure and the fine line structure are covered on the substrate. A transparent electrode is continuously formed. Since this gravure offset printing can be performed at high speed by rotation of the gravure roll and the offset roll, it is possible to efficiently form the fine line structure and the transparent electrode on the substrate. Moreover, since the gravure roll and the offset roll are easy to adjust mechanically and can be rotated precisely, the alignment accuracy between the substrate, the fine wire structure, and the transparent electrode can be improved.
Furthermore, this configuration does not require expensive and large-scale equipment as in the conventional sputtering method. Therefore, the types of applicable substrates are wide, and the manufacturing cost of the conductive thin film structure can be reduced. Further, as compared with the conventional sputtering method, the amount of energy to be used can be reduced, and there is an advantage that no cleaning water is required.

In the conductive thin film structure according to the present invention, the fine wire structure preferably has a line width of 10 μm or less, and the blanket material is set to have a thickness of 3 mm or more and a rubber shore hardness of 20 or less.

In the case of the conductive thin film structure of this configuration, a fine line structure having a line width of 10 μm or less is efficiently obtained by setting the blanket material covering the surface of the offset roll to a thickness of 3 mm or more and a rubber shore hardness of 20 or less. It can be formed well and reliably.

The conductive thin film structure according to the present invention is preferably used as a component of a solar cell panel, a touch panel, a liquid crystal panel, or an organic EL panel.

With the conductive thin film structure having this configuration, a high quality conductive thin film structure that achieves both high light transmittance and low resistance can be provided efficiently and at low cost. Can be suitably used as a component of a solar cell panel, a touch panel, a liquid crystal panel, or an organic EL panel, which is expected to increase more and more.

In order to solve the above-mentioned problems, the characteristic configuration of the method for producing a conductive thin film structure according to the present invention includes a fine line structure forming step of forming a fine line structure on a substrate, A transparent electrode forming step of forming a transparent electrode that covers the fine wire structure, wherein the fine wire structure and the transparent electrode are formed on the substrate using a gravure roll and an offset roll. It is formed continuously by performing gravure offset printing, and the offset roll has a surface covered with a blanket material.

The manufacturing method of the conductive thin film structure of this configuration has substantially the same effect as the above-described conductive thin film structure. That is, in the method for producing a conductive thin film structure of this configuration, gravure offset printing is performed using a gravure roll and an offset roll whose surface is covered with a blanket material, and the fine line structure and the fine line structure are formed on a substrate. A transparent electrode to be coated is continuously formed. Since this gravure offset printing can be performed at high speed by rotation of the gravure roll and the offset roll, it is possible to efficiently form the fine line structure and the transparent electrode on the substrate. Moreover, since the gravure roll and the offset roll are easy to adjust mechanically and can be rotated precisely, the alignment accuracy between the substrate, the fine wire structure, and the transparent electrode can be improved.
Furthermore, this configuration does not require expensive and large-scale equipment as in the conventional sputtering method. Therefore, the types of applicable substrates are wide, and the manufacturing cost of the conductive thin film structure can be reduced. Further, as compared with the conventional sputtering method, the amount of energy to be used can be reduced, and there is an advantage that no cleaning water is required.

In the method for manufacturing a conductive thin film structure according to the present invention, it is preferable that the fine wire structure has a line width of 10 μm or less, and the blanket material is set to have a thickness of 3 mm or more and a rubber shore hardness of 20 or less.

The manufacturing method of the conductive thin film structure of this configuration has substantially the same effect as the above-described conductive thin film structure. That is, the manufacturing method of the conductive thin film structure of this configuration is such that the blanket material that covers the surface of the offset roll is set to a thickness of 3 mm or more and a rubber shore hardness of 20 or less, so that a fine fine wire having a line width of 10 μm or less. The structure can be formed efficiently and reliably.

It is a schematic diagram of the manufacturing apparatus of the electroconductive thin film structure for enforcing the manufacturing method of the electroconductive thin film structure of this invention. It is a perspective view which illustrates the structure of the electroconductive thin film structure of this invention.

Hereinafter, embodiments of the present invention will be described. First, the manufacturing method of the conductive thin film structure of the present invention will be described with reference to FIG. 1, and then the conductive thin film structure of the present invention will be described with reference to FIG. However, the present invention is not intended to be limited to the configurations described in the embodiments and drawings described below, and includes configurations equivalent thereto.

[Method for producing conductive thin film structure]
FIG. 1 is a schematic view of a conductive thin film structure manufacturing apparatus 100 for carrying out the method of manufacturing a conductive thin film structure of the present invention. The conductive thin film structure manufacturing apparatus 100 includes a belt conveyor unit 10, a thin wire structure forming unit 20, and a transparent electrode forming unit 30.

The belt conveyor unit 10 includes a driving roller 11 driven by a motor, a driven roller 12 arranged in a set with the driving roller 11, and a belt 13 connecting the driving roller 11 and the driven roller 12. In FIG. 1, the driving roller 11 and the driven roller 12 are rotated in the clockwise direction. Accordingly, the substrate 1 placed on the belt 13 moves from left to right in the drawing.

The fine line structure forming unit 20 includes a gravure roll 21 and an offset roll 22 as main components. The gravure roll 21 is a metal cylinder, and an intaglio 21a serving as a mold of a thin wire structure is formed on the surface of the cylinder. The intaglio 21a is filled with a conductive paste that is a material having a thin wire structure supplied from a raw material supply source (not shown). Excess conductive paste protruding from the intaglio 21a is removed by the blade 21b.

The offset roll 22 is formed of a metal cylinder similar to the gravure roll 21, and the surface thereof is covered with a blanket material 22a. The blanket material 22 a of the offset roll 22 is in contact with the gravure roll 21. As a result, the conductive paste filled in the intaglio 21a of the gravure roll 21 is transferred to the surface of the blanket material 22a of the offset roll 22. Then, the transferred conductive paste is printed on the surface of the substrate 1 conveyed by the belt conveyor unit 10. At the time of printing, the substrate 1 is sandwiched between the offset roll 22 and the pressure roll 23 and is pressure-bonded. In particular, when the substrate 1 is a hard substrate, offset printing can be reliably performed on the surface of the substrate 1 by performing this pressure bonding step. In this way, the “thin line structure forming step” of the present invention is executed. After the conductive paste is printed on the substrate 1, the offset roll 22 is brought into pressure contact with the metal roller cylinder 24, and the conductive paste remaining on the surface of the blanket material 22a is precisely removed.

The transparent electrode forming unit 30 has substantially the same structure as the fine line structure forming unit 20. That is, the transparent electrode forming unit 30 includes, as main constituent elements, a gravure roll 31 formed of a metal cylinder having an intaglio 31a on the surface, and a metal cylinder, and the surface thereof is a blanket material 32a. The offset roll 32 covered with First, the intaglio 31a on the surface of the gravure roll 32 is filled with a transparent electrode material (for example, tin-doped indium oxide) supplied from a raw material supply source (not shown). The transparent electrode material filled in the intaglio 31a is transferred to the surface of the blanket material 32a of the offset roll 32. The transferred transparent electrode material is printed on the surface of the substrate 1 conveyed by the belt conveyor unit 10. Here, the fine line structure 2 is already printed on the substrate 1 by the fine line structure forming unit 20. Therefore, the transparent electrode material is printed from above the thin line structure 2. At the time of printing, the substrate 1 is sandwiched between the offset roll 32 and the pressure roll 33 and is pressure bonded. Thereby, the fine wire structure 2 and the transparent electrode 3 covering the thin wire structure 2 are formed on the substrate 1. In this way, the “transparent electrode forming step” of the present invention is executed. After the transparent electrode forming step, a drying step or a heating step can be performed as necessary. In addition, after printing the transparent electrode material on the substrate 1, the offset roll 32 is brought into pressure contact with the metal roller cylinder 34, and the transparent electrode material remaining on the surface of the blanket material 32a is precisely removed.

According to the manufacturing apparatus 100 of the present invention, the gravure rolls 21 and 31 and the offset rolls 22 and 32 are used, and the gravure offset printing is performed on the substrate 1, whereby the fine wire structure 2 and the transparent electrode 3 are formed on the substrate 1. It can be formed continuously. In this gravure offset printing, the fine line structure 2 and the transparent electrode 3 can be efficiently formed on the substrate 1 by rotating the gravure rolls 21 and 31 and the offset rolls 22 and 32 at high speed. Further, since the gravure rolls 21 and 31 and the offset rolls 22 and 32 are easy to adjust mechanically and can be rotated precisely, the alignment accuracy between the substrate 1, the thin wire structure 2 and the transparent electrode 3 is improved. It can be good. For example, even if the line width of the thin line structure 2 is 10 μm or less, the transparent electrode 3 can be printed at an appropriate position with respect to the fine line. Furthermore, the method using gravure offset printing of the present invention does not require expensive and large-scale equipment as in the conventional sputtering method, so the types of applicable substrates are wide-ranging, such as solar cell panels, touch panels, liquid crystal panels, Or the manufacturing cost of the electroconductive thin film structure used suitably as components, such as an organic electroluminescent panel, can be reduced. Further, as compared with the conventional sputtering method, the amount of energy to be used can be reduced, and there is an advantage that no cleaning water is required.

In manufacturing the conductive thin film structure, it is preferable to set the blanket material 22a covering the surface of the offset roll 22 in the thin wire structure forming unit 20 to a thickness of 3 mm or more and a rubber shore hardness of 20 or less. Thereby, it is possible to continue printing stably while reducing the line width of the thin line structure 2 to 10 μm or less. When the thickness of the blanket material 22a is 3 mm or less, the conductive paste soaks into the blanket material 22a and easily reaches the saturation point, the maintenance frequency of the offset roll 22 increases, and the production efficiency of the conductive thin film structure decreases. There is a fear. In the present invention, the upper limit of the thickness of the blanket material 22a is preferably 30 mm or less. If the thickness of the blanket material exceeds 30 mm, the blanket material may be deformed due to an increase in weight, and the alignment accuracy during printing may be reduced. The lower limit of rubber shore hardness is 2. If the rubber shore hardness is less than 2, the blanket material becomes a gel, and as a result, the roll shape of the offset roll 22 may be deformed. Within the scope of the present invention, the high-quality fine wire structure 2 can be formed efficiently and reliably.

Of the transparent electrode forming unit 30, the blanket material 32 a covering the surface of the offset roll 32 is also preferably set to the same conditions as the blanket material 22 a of the thin wire structure forming unit 20. Thereby, the thin wire structure 2 can be reliably covered while making the thickness of the transparent electrode 3 as thin as possible. As a result, the high-quality transparent electrode 3 can be formed efficiently and reliably.

Examples of materials that can be used for the blanket materials 22a and 32a include elastic materials such as silicone resins, fluorine resins, urethane resins, synthetic rubbers, and natural rubbers. In particular, the silicone-based resin has high durability and oil resistance, and has a sufficient stiffness with sufficient elasticity, and is particularly suitable for performing gravure offset printing on a hard substrate. The blanket material used in this embodiment is a two-component addition reaction curable liquid silicone rubber “Elastosil (registered trademark)” manufactured by Wacker Chemie.

[Conductive thin film structure]
FIG. 2 is a perspective view illustrating the structure of the conductive thin film structure 5 of the present invention. The conductive thin film structure 5 is manufactured by the manufacturing method of the conductive thin film structure 5 described above. The conductive thin film structure 5 includes a substrate 1, a fine wire structure 2 formed on the substrate 1, and a transparent electrode 3 formed on the substrate 1 so as to cover the fine wire structure 2. The substrate 1 may be a hard substrate (eg, metal, glass, hard resin, etc.), or may be a soft substrate (eg, rubber, wood, soft resin, etc.).

The thin wire structure 2 and the transparent electrode 3 are continuously formed by performing gravure offset printing on the substrate 1 using the above-described gravure rolls 21 and 31 and offset rolls 22 and 32. Here, the surfaces of the offset rolls 22 and 32 are covered with blanket materials 22a and 32a, respectively. The blanket materials 22a and 32a are preferably set to a thickness of 3 mm or more and a rubber shore hardness of 20 or less. Thereby, it becomes easy to reduce the line width of the thin line structure 2 to 10 μm or less. In addition, the fine thin wire structure 2 can be efficiently and reliably formed, and the transparent electrode 3 can be efficiently and reliably formed on the thin wire structure 2 with high alignment accuracy. Can do. The conductive thin film structure 5 of the present invention is a high quality conductive thin film structure that achieves both high light transmittance and low resistance, and in particular, a solar cell panel, a touch panel, a liquid crystal panel, or an organic EL. It can be suitably used as a panel component.

[Another embodiment]
<1> In the above embodiment, the conductive thin film structure 5 having a two-layer structure in which the thin wire structure 2 and the transparent electrode 3 are formed on the substrate 1 has been described. However, using the technical idea of the present invention, it is also possible to manufacture a conductive thin film structure having a three-layer structure or more, for example, by laminating a plurality of transparent electrode layers on a fine wire structure. In this case, a gravure offset printing unit including a gravure roll and an offset roll may be added according to the number of layers in the conductive thin film structure manufacturing apparatus.

<2> In the above embodiment, both the fine wire structure 2 and the transparent electrode 3 are formed by gravure offset printing. However, when only the alignment accuracy of the fine line structure 2 with respect to the substrate 1 is required, the fine line structure 2 can be formed by gravure offset printing, and the transparent electrode 3 can be formed by other methods.

As described above, the conductive thin film structure 5 and the method of manufacturing the conductive thin film structure 5 according to the present invention have a solar cell panel, a touch panel, a liquid crystal panel, or an organic material whose demand is expected to increase in the future. The present invention can be suitably used for EL panel components and methods for manufacturing the components.

DESCRIPTION OF SYMBOLS 1 Substrate 2 Fine line structure 3 Transparent electrode 5 Conductive thin film structure 21 Gravure roll 22 for fine line structure printing Offset roll 22a for fine line structure printing Blanket material 31 for fine line structure printing Gravure roll 32 for transparent electrode printing Offset roll 32a for transparent electrode printing Blanket material for transparent electrode printing 100 Conductive thin film structure manufacturing apparatus

Claims (5)

A substrate,
A fine wire structure formed on the substrate;
A transparent electrode formed on the substrate so as to cover the fine wire structure;
A conductive thin film structure comprising:
The fine wire structure and the transparent electrode are continuously formed by performing gravure offset printing on the substrate using a gravure roll and an offset roll, and the offset roll has a surface covered with a blanket material. Conductive thin film structure. 2. The conductive thin film structure according to claim 1, wherein the fine wire structure has a line width of 10 μm or less, and the blanket material is set to a thickness of 3 mm or more and a rubber shore hardness of 20 or less. The electroconductive thin film structure of Claim 1 or 2 used as components of a solar cell panel, a touch panel, a liquid crystal panel, or an organic EL panel. A fine line structure forming step for forming a fine line structure on the substrate;
A transparent electrode forming step of forming a transparent electrode covering the fine line structure on the substrate on which the fine line structure is formed;
A method for producing a conductive thin film structure comprising:
The thin wire structure and the transparent electrode are continuously formed by performing gravure offset printing on the substrate using a gravure roll and an offset roll, and the offset roll is a conductive thin film whose surface is covered with a blanket material. Manufacturing method of structure. 5. The method of manufacturing a conductive thin film structure according to claim 4, wherein the fine wire structure has a line width of 10 μm or less, and the blanket material is set to a thickness of 3 mm or more and a rubber shore hardness of 20 or less.

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