TW201405587A - Element for conductive film, conductive film laminated body, electronic equipment, and method of manufacturing element for conductive film and conductive film laminated body - Google Patents

Abstract

Provided is an element for a conductive film having an amorphous layer that can easily be crystallised by heat treatment, in which the sheet resistance when crystallised is low and in which increase of film thickness is suppressed. The element for a conductive film has a transparent substrate and an amorphous layer made of indium oxide deposited on the aforementioned transparent substrate. The amorphous layer is made of indium-tin oxide, containing 5.5 to 9 mass% of tin calculated as the oxide and is of film thickness 15 to 25 nm and sheet resistance 50 to 100Omega/- when crystallised.

Description

Conductive film material, conductive film laminate, electronic device, and conductive film material and conductive film laminate Field of invention

The present invention relates to a material for a conductive film, a conductive film laminate, an electronic device, a material for a conductive film, and a method for producing a conductive film laminate.

Background of the invention

Since the transparent conductive film has electrical conductivity and optical transparency, it can be used as a transparent electrode, an electromagnetic wave shielding film, a planar heat generating film, and an antireflection film. In recent years, electrodes for touch panels have attracted attention. There are various ways for the touch panel such as a resistive film type, a static capacitance combined type, an optical type, and the like. As the transparent conductive film, for example, a resistive film type in which a touch position is contacted by the lower electrode described above, and a capacitive coupling method in which a change in electrostatic capacitance is induced can be used. The transparent conductive film used in the resistive film type is mechanically in contact with each other in the principle of operation, and thus is required to have high durability. Further, since the transparent conductive film of the resistive film type or a part of the resistive film type is formed by etching to form a plurality of transparent electrodes to have a specific pattern, it is required to have good etching properties. Further, since the transparent conductive film is disposed on the front surface of the display portion, it is required to have high light transmittance.

The transparent conductive film may be composed of indium tin oxide. Durability can be improved by crystallizing indium tin oxide. However, indium tin oxide which is a transparent conductive film may form a plurality of transparent electrodes by etching, and once crystallized, it is difficult to form a plurality of transparent electrodes by etching. For example, when indium tin oxide is crystallized, the etching rate is lowered, so that formation of a transparent electrode takes time or the shape of the transparent electrode cannot become a desired shape.

From the above viewpoint, first, an indium tin oxide which is easily etched in an amorphous state is formed into a film, and the indium tin oxide in an amorphous state is etched to form a plurality of transparent electrodes, and then crystallized by heat treatment. good. At this time, it is required that the indium tin oxide in an amorphous state is easily crystallized by heat treatment. Further, it is also required to have a lower specific resistance after crystallization. When the specific resistance is low, the sheet resistance value can be reduced even if the film thickness is reduced. Further, the transparent conductive film requires a high transmittance, but by reducing the film thickness, the transmittance can be improved. In the past, an indium tin oxide containing about 3% by mass of tin in terms of an oxide is used because it has a low specific resistance after being crystallized and is crystallized by heat treatment (see, for example, Patent Documents 1 to 3).

Prior technical literature Patent literature

Patent Document 1: Japanese Laid-Open Patent Publication No. 2011-65937

Patent Document 2: Japanese Laid-Open Patent Publication No. 2011-100749

Patent Document 3: Japanese Laid-Open Patent Publication No. 2004-149884

Summary of invention

In recent years, with the increase in the size of electronic devices such as touch panel devices, the reduction in the transmission speed of the transparent conductive film during operation has been troublesome. In order to suppress the decrease in the communication speed, it is necessary to reduce the sheet resistance value of the transparent conductive film more recently. Specifically, it is required to reduce the sheet resistance of the transparent conductive film to 150 Ω/□ or less.

In the case of the indium tin oxide containing about 3% by mass of tin in terms of oxide, the sheet resistance value after crystallization is reduced by increasing the film thickness, but in order to obtain a predetermined sheet resistance value, The film thickness must be sufficiently thick enough. In view of the fact that the film thickness is preferably 25 nm or less, the indium tin oxide containing about 3% by mass of tin in terms of oxide is required to obtain a predetermined sheet resistance value. A film thickness of, for example, more than 25 nm is produced.

On the other hand, as a constituent material of the transparent conductive film, indium tin oxide containing about 10% by mass of tin in terms of oxide is known, and indium tin containing about 3% by mass of tin in terms of oxide is known. The oxide can further reduce the sheet resistance value after crystallization. However, indium tin oxide containing about 10% by mass of tin in terms of oxide is not necessarily easily crystallized, and when it is at a thickness required for crystallization, the optical characteristics such as transmittance are not good.

The present invention has been made to solve the above problems, and an object of the invention is to provide a material for a conductive film having an amorphous layer, which is easy to be crystallized by heat treatment, and has a low sheet resistance value after crystallization. The increase in film thickness is suppressed. Moreover, it is an object of the present invention to provide a tablet A conductive film laminate having a low resistance value and an increase in film thickness, which is suppressed by a crystalline layer, and an electronic device having the conductive film laminate. Further, an object of the present invention is to provide a material for a conductive film and a method for producing a conductive film laminate.

The material for a conductive film of the present invention has a transparent substrate and an amorphous layer, and the amorphous layer is composed of indium tin oxide laminated on the transparent substrate. The amorphous layer is composed of indium tin oxide containing 5.5 to 9% by mass of tin in terms of oxide, and has a sheet thickness of 15 to 25 nm and a sheet resistance of 50 to 150 Ω/□ after crystallization. .

The conductive film laminate of the present invention has a transparent substrate and a crystal layer, and the crystal layer is composed of indium tin oxide laminated on the transparent substrate. The crystal layer is composed of indium tin oxide containing 5.5 to 9% by mass of tin in terms of oxide, and has a film thickness of 15 to 25 nm and a sheet resistance of 50 to 150 Ω/□.

The electronic apparatus of the present invention is characterized by having the above-described conductive film laminate of the present invention.

The method for producing a material for a conductive film of the present invention is characterized by having a film forming step of depositing an amorphous layer on a transparent substrate by sputtering using a sputtering target, which is a sputtering target The material is composed of indium tin oxide containing 5.5 to 9% by mass of tin in terms of oxide, and the film thickness of the amorphous layer is 15 to 25 nm and the sheet resistance after crystallization is 50 to 150 Ω/ □.

The method for producing a conductive film laminate according to the present invention is characterized in that the film forming step is performed by using a sputtering target and sputtering. A material for a conductive film is formed by forming an amorphous layer on a substrate, and the sputtering target is made of indium tin oxide containing 5.5 to 9% by mass of tin in terms of oxide, and the amorphous layer is formed. The film thickness is 15 to 25 nm and the sheet resistance value after crystallization is 50 to 150 Ω/□. In the heat treatment step, the conductive film is heat-treated to crystallize the amorphous layer to form a crystal. Quality layer.

The method for producing a conductive film laminate according to the present invention is characterized in that the film forming step is performed by using a sputtering target and forming an amorphous layer on a transparent substrate by a sputtering method to obtain a conductive film. In the material, the sputtering target is made of indium tin oxide containing 5.5 to 9% by mass of tin in terms of oxide, and the thickness of the amorphous layer is 15 to 25 nm and the sheet resistance is crystallized. a value of 50 to 150 Ω/□; a step of patterning the amorphous layer of the material for the conductive film by etching; and a heat treatment step of heat-treating the patterned conductive film with the material to form the amorphous layer Crystallization is carried out to form a crystalline layer.

According to the present invention, it is possible to provide a material for a conductive film having an amorphous layer, and the amorphous layer is easily crystallized by heat treatment, and the sheet resistance after crystallization is low and the increase in film thickness is suppressed. Further, according to the present invention, it is possible to provide a conductive film laminate having a sheet resistance having a low sheet resistance and an increase in film thickness, and an electronic device having the conductive film laminate. Further, according to the present invention, a method for producing the above-mentioned material for a conductive film and a laminated body of a conductive film can be provided.

10‧‧‧Material for conductive film

11‧‧‧Transparent substrate

12‧‧‧Amorphous layer

20‧‧‧Conductor laminar body

21‧‧‧The grain layer

Fig. 1 is a cross-sectional view showing an embodiment of a material for a conductive film.

Fig. 2 is a cross-sectional view showing an embodiment of a conductive film laminate.

Fig. 3 shows an example of the relationship between the oxygen flow rate at the time of film formation of the amorphous layer and the sheet resistance value before and after heat treatment of the amorphous layer.

The relationship between the content of tin in the sputtering target and the oxygen flow rate (optimum flow rate) when the sheet resistance value becomes the lowest value is shown in FIG.

Form for implementing the invention

The invention is described in detail below.

Fig. 1 is a cross-sectional view showing an embodiment of a material for a conductive film.

The material 10 for a conductive film has, for example, a transparent substrate 11 and an amorphous layer 12, and the amorphous layer 12 is made of an indium tin oxide in an amorphous state laminated on the transparent substrate 11. The conductive material 10 for a conductive film can be produced by using a conductive film laminate in which a crystalline transparent conductive film is laminated on a transparent substrate 11, and the crystalline transparent conductive film is made of a crystalline indium tin oxide. In other words, the amorphous layer 12 is crystallized by heat treatment to form a crystalline transparent conductive film.

Here, the amorphous and crystalline phases are immersed in a HCl solution (concentration: 1.5 mol/L) for about 3 minutes, and the resistance value is measured to obtain a resistance value change rate (resistance value after immersion/resistance value before immersion). The evaluation is made by the rate of change of the resistance value. The case where the resistance value change rate exceeds 200% is evaluated as amorphous, and the case where the resistance value change rate is 200% or less is evaluated as crystal.

The transparent substrate 11 is preferably a polyolefin such as polyethylene or polypropylene; polyester such as polyethylene terephthalate, polybutylene terephthalate or polyethylene naphthalate, nylon 6, nylon 66 Polyamide, polyimine, polyarylate, polycarbonate, polyacrylate, polyether, polyfluorene, and the like A stretched or stretched plastic film of the copolymer. Further, as the transparent substrate 11, other plastic films having high transparency can also be used. Among these, a plastic film composed of polyethylene terephthalate is preferred.

An undercoat layer such as a hard coat layer may be formed on one or both sides of the transparent substrate 11. Further, the transparent substrate 11 may be subjected to surface treatment such as easy subsequent treatment, plasma treatment, and corona treatment. The thickness of the transparent substrate 11 is preferably from 10 to 200 μm from the viewpoints of flexibility and durability.

As the hard coat layer, a transparent and hard organic material layer can be mentioned. The thickness of the hard coat layer is preferably from 1 to 15 μm, and more preferably from 1.5 to 10 μm. When the film thickness of the hard coat layer is 1 μm or more, the desired effect can be obtained by the formation of the hard coat layer. Further, when the film thickness is 15 μm or less, the film formation efficiency can be suppressed from being lowered, and crack generation can be suppressed.

The hard coat layer is composed of, for example, a curable resin or a thermosetting resin which is cured by free radiation. The curable resin material hardened by the free radiation may contain an acrylic material, a polyfunctional or polyfunctional (meth) acrylate compound such as a polyacrylic acid or a methacrylate, and a diisocyanate and a poly A synthetic polyfunctional urethane (meth) acrylate compound such as an alcohol and a hydroxy ester of acrylic acid or methacrylic acid. Further, a polyether resin having an acrylate functional group, a polyester resin, an epoxy resin, an alkyd resin, a acetal resin, a polybutadiene resin, a polythiol polyene resin, or the like may be used. Further, a thermosetting polydecane resin or the like can also be used.

As a coating method of the curable resin, a wet film formation method is preferred, and a roll coater, a reverse roll coater, a concave plate coater, and a micro-concave plate are used. The coating method of the applicator, the knife coater, the rod coater, the wire rod coater, the die coater, and the dip applicator is preferred.

As the radical radiation, for example, ultraviolet rays or electron rays can be used. In the case of ultraviolet curing, a high-pressure mercury lamp, a low-pressure mercury lamp, an ultra-high pressure mercury lamp, a metal halide lamp, a carbon arc, a xenon arc or the like can be used. In addition, in the case of electron beam hardening, it can be used by Krakow-Worthon type, Van de Graaff type, resonance transformer type, insulated core transformer type, linear type, high frequency high voltage (Dynamitron) type, high Electron rays emitted by various electron ray accelerators such as frequency type.

In order to promote crystallization of the amorphous layer 12 during heat treatment, a primer layer (not shown) may be provided between the transparent substrate 11 and the amorphous layer 12. The underlayer is not particularly limited as long as it can promote crystallization of the amorphous layer 12, and examples thereof include those made of an inorganic compound such as a metal, an oxide of a metal, a sulfide, or a fluoride. Among them, ruthenium oxide or aluminum oxide is preferred, and ruthenium oxide is preferred, and SiOx (x is 1.5 to 2) is preferred.

The thickness of the underlayer is not particularly limited as long as it can promote crystallization of the amorphous layer 12 during heat treatment, and is preferably 1 nm or more, and more preferably 3 nm or more. The thickness of the underlayer is 1 nm or more, and the crystallization of the amorphous layer 12 can be effectively promoted. When the thickness of the underlayer is about 5 nm, the crystallization of the amorphous layer 12 can be sufficiently promoted, and when it is 10 nm or less, good productivity and transparency can be obtained.

The amorphous layer 12 is in an amorphous state at the stage of the material 10 for a conductive film, and is crystallized by heat treatment to form a crystal layer (that is, a crystalline transparent conductive film). The amorphous layer 12 is composed of indium tin oxide which is an oxide of indium and tin, and the indium tin oxide is 5.5 to 9 mass% in terms of oxide (in terms of SnO ₂ in terms of tin oxide). Tin. Examples of the oxide constituting the indium tin oxide include indium oxide, tin oxide, and a composite oxide of indium oxide and tin oxide.

When the amorphous layer 12 is made of indium tin oxide containing 5.5 to 9% by mass of tin in terms of oxide, it is easy to crystallize by heat treatment and crystallize it. The sheet resistance after the reduction is low and the increase in film thickness is suppressed. Specifically, it can be made into a film thickness of 15 to 25 nm and the sheet resistance value after crystallization is 50 to 150 Ω/□, and it is easy to crystallize by heat treatment. Further, in the same manner as described above, the etching property can be improved as well. The content of tin in the indium tin oxide in terms of oxide is preferably 5.8 mass% or more, and more than 6% by mass, from the viewpoint of easiness of crystallization by heat treatment and sheet resistance value after crystallization. Good, and more preferably 6.5 mass% or more. Further, it is preferably 8.9 mass% or less, more preferably 8.5 mass% or less, and still more preferably 8.3% by mass or less. In the following, the tin oxide content of tin in the indium tin oxide in terms of oxide is sometimes expressed as the tin oxide content.

The thickness of the amorphous layer 12 is not particularly limited as long as it is 15 to 25 nm, and is preferably 20 to 25 nm from the viewpoints of easiness of crystallization by heat treatment and optical properties such as transmittance. In addition, the sheet resistance value of the amorphous layer 12 after crystallization is not particularly limited as long as it is 50 to 150 Ω/□, but the transmission speed is suppressed from the operation of an electronic device such as a touch panel. From the viewpoint of easiness of crystallization by heat treatment, it is preferably 80 to 150 Ω/□, and more preferably 100 to 150 Ω/□.

The amorphous layer 12 should be composed only of indium tin oxide, but it can be adapted It is required and contains components other than indium tin oxide without departing from the gist of the present invention. Examples of the component other than the indium tin oxide include oxides of aluminum, zirconium, gallium, germanium, tungsten, zinc, titanium, magnesium, lanthanum, cerium, and the like. The content of the component other than the indium tin oxide in the amorphous layer 12 is 10% by mass or less, preferably 5% by mass or less, preferably 3% by mass or less, and preferably 1% by mass or less. Especially good.

The conductive film material 10 can be a conductive film laminate in which a crystalline transparent conductive film made of a crystalline indium tin oxide is laminated on the transparent substrate 11 by heat treatment. In other words, the amorphous layer 12 can be crystallized by heat treatment to form a crystalline layer (that is, a crystalline transparent conductive film) to form a conductive film laminate.

The heat treatment is preferably carried out in the atmosphere at 100 to 150 ° C for 30 to 180 minutes. By setting the heat treatment temperature to 100 ° C or higher and setting the heat treatment time to 30 minutes or more, the amorphous layer 12 can be effectively crystallized. In addition, by setting the heat treatment temperature to 150 ° C and setting the heat treatment time to 180 minutes, crystallization can be sufficiently performed, and when it is 150 ° C or less and 180 minutes or less, the damage of the transparent substrate 11 or the like can be suppressed. It can suppress the decrease in productivity.

FIG. 2 is a cross-sectional view showing an embodiment of the conductive film laminate 20 obtained by heat-treating the conductive material 10 for a conductive film. The conductive film laminate 20 has, for example, a transparent substrate 11 and a crystal layer 21 laminated on the transparent substrate 11. As described above, the crystal layer 21 is formed by crystallizing the amorphous layer 12 by heat treatment, and is used as a crystalline transparent conductive film.

When a conductive film laminate having a plurality of transparent electrodes formed by etching a transparent conductive film is formed, it is also possible to use a conductive film for a conductive film. The amorphous layer 12 of the material 10 is subjected to a desired patterning by an etching process in an amorphous phase, and the patterned amorphous layer (i.e., a plurality of transparent electrodes in an amorphous state) is crystallized by heat treatment. The crystalline transparent conductive film, that is, the crystalline layer 21 (i.e., a plurality of transparent electrodes in a crystalline state) is formed. In this manner, first, a film of an indium tin oxide in an amorphous state which does not require time for etching is formed, and a film of the indium tin oxide in an amorphous state is etched to form a plurality of transparent electrodes, and then a plurality of transparent electrodes are formed. The heat treatment causes crystallization, whereby no excessive time is required for the etching process for forming the transparent electrode, and a pattern of a plurality of transparent electrodes can be obtained to form a favorable conductive film laminate having a desired shape.

Alternatively, a crystalline transparent conductive film may be formed by crystallization of an amorphous layer by heat treatment, and then a plurality of transparent electrodes or the like may be formed by performing a desired patterning on the crystalline transparent conductive film by etching.

The crystal layer 21 is composed of indium tin oxide which is an oxide of indium and tin, and the indium tin oxide contains 5.5 to 9% by mass of tin in terms of oxide. The tin oxide content of tin in the indium tin oxide is preferably 5.8% by mass or more, more preferably 6% by mass, and more preferably 6.5 mass% or more. Further, it is preferably 8.9 mass% or less, more preferably 8.5 mass% or less, and still more preferably 8.3% by mass or less. Further, the indium tin oxide preferably has a crystal structure of indium oxide (In ₂ O ₃ ) and is substituted with tin on the indium side.

The film thickness of the crystal layer 21 is not particularly limited as long as it is 15 to 25 nm, and it is preferably 15 to 25 nm from the viewpoints of easiness of crystallization by heat treatment and optical characteristics at the time of production. It is preferably 20 to 25 nm. Moreover, the sheet resistance of the crystal layer 21 is not particularly high as long as it is 50 to 150 Ω/□. It is not limited, but it is preferably 80 to 150 Ω/□ and 100 to 150 Ω from the viewpoint of suppressing the decrease in speed and the ease of crystallization in the operation of an electronic device such as a touch panel. /□ is better.

The above-mentioned conductive film laminate 20 is suitably used in an electronic device. In particular, from the viewpoint that the sheet-like transparent conductive film, that is, the sheet layer 21 has a sheet resistance value as low as 150 Ω/□ or less and a small decrease in the conveyance speed after the enlargement, it is suitable for use in an enlarged electronic apparatus.

The electronic device may be, for example, a liquid crystal display device, a plasma display device, a touch panel device, or the like, and particularly a touch panel device. The touch panel device includes, for example, a display unit and a touch panel unit disposed on the front surface of the display unit. The conductive film laminate 20 can be used as a transparent electrode substrate having a transparent electrode in such a touch panel portion. The touch panel portion may be any one of a resistive film type in which a touch position is specified by a contact between upper and lower electrodes, and a capacitive coupling method in which an electrostatic capacitance changes.

Next, a method of manufacturing the conductive film material 10 and the conductive film laminate 20 will be described.

After the underlayer is formed on the transparent substrate 11 as needed, the amorphous layer 12 made of an indium tin oxide in an amorphous state is formed, whereby the conductive film material 10 can be produced. The film formation method is not limited, but a sputtering method, an ion plating method, or a vacuum evaporation method is preferred, and a sputtering method is preferred.

When the sputtering method is applied, it is preferable to use a sputtering target composed of a sintered body of indium tin oxide, which is obtained by mixing and sintering tin oxide (SnO ₂ ) and indium oxide (In ₂ O ₃ ). Further, it is preferable that the sputtering target contains 5.5 to 9% by mass of tin in terms of oxide in the indium tin oxide. The tin oxide content of tin in the indium tin oxide is preferably 5.8% by mass or more, more preferably 6% by mass or more, and particularly preferably 6.5% by mass or more. Further, it is preferably 8.9 mass% or less, more preferably 8.5 mass% or less, and particularly preferably 8.3 mass% or less.

The film formation of the amorphous layer 12 is preferably performed by, for example, introducing a mixed gas of 0.5 to 10% by volume and preferably 0.8 to 6% by volume of oxygen in argon gas into the sputtering apparatus. By performing sputtering while introducing the mixed gas, it is possible to form an amorphous layer 12 which is amorphous and which is easily crystallized by heat treatment and crystallized to have a low sheet resistance value.

Further, before the film formation of the amorphous layer 12, the environmental conditions are preferably as follows: first, the degree of vacuum in the sputtering apparatus is evacuated to 5 × 10 ^-4 Pa or less and desirably 9 × 10 ^-5 Pa or less, and removed. Moisture in the sputtering apparatus or impurities such as moisture or organic gas generated by the transparent substrate 11 or the like. When the presence of moisture or an organic gas in the film formation is reduced, it is easy to obtain a sheet having a low sheet resistance value which is easily crystallized by heat treatment and crystallized.

Fig. 3 shows an example of the relationship between the oxygen flow rate at the time of film formation of the amorphous layer 12 and the sheet resistance value of the amorphous layer 12 before and after the heat treatment (the tin oxide content in the target is 5% by mass).

On the other hand, the amorphous layer 12 is formed by forming a film of SiOx (x is 1.5 to 2) having a thickness of 50 Å as a bottom layer on a PET film having a thickness of 100 μm as a transparent substrate 11, and then using a thickness of SiOx film as a bottom layer. 255 angstroms were formed into a film.

Specifically, the SiOx film was a boron-doped polycrystalline ruthenium target, and a mixed gas of 11% by volume of oxygen mixed with argon gas was introduced, and an AC magnetron sputtering was performed under a pressure of 3.7 Pa to form a film. Further, the amorphous layer 12 is formed by using a sputtering target composed of indium tin oxide to introduce a mixture of argon gas and oxygen gas. The gas was changed in oxygen flow rate and subjected to DC magnetron sputtering at a pressure of 0.8 Pa, and the indium tin oxide contained 5.0% by mass of tin in terms of oxide.

As is apparent from Fig. 3, the sheet resistance value is the lowest value when the oxygen flow rate at the time of film formation of the amorphous layer reaches a specific value. Moreover, the smaller the flow rate or the more the flow rate, the larger the sheet resistance value is compared with the flow rate when the sheet resistance value is the lowest value. Further, although not shown, the flow rate is smaller as compared with the flow rate when the sheet resistance value is the lowest value, and the more difficult it is to heat-treat and crystallize. On the other hand, the more the flow rate is compared with the flow rate when the sheet resistance value is the lowest value, the easier the sheet resistance value after heat treatment increases with the passage of time in units of years.

From this, it is understood that the oxygen flow rate at the time of film formation of the amorphous layer 12 is preferably in the range of 0.6 to 1.4 times, preferably in the range of 0.7 to 1.3 times, with respect to the flow rate when the sheet resistance value at the crystallization is the lowest. And especially in the range of 0.8 to 1.2 times. Therefore, in actual film formation of the amorphous layer 12, it is preferable to determine the oxygen flow rate when the resistance value of the crystallized sheet is the lowest value by the above method, and adjust the oxygen flow rate so as to be within the above range with respect to the oxygen flow rate. . In view of the fact that the optimum flow rate is slightly different depending on the film forming apparatus, the film having a low resistance value after crystallization can be effectively formed by the above method.

FIG. 4 shows an example of the relationship between the tin oxide content in terms of oxide in terms of oxide in the sputtering target and the oxygen flow rate when the sheet resistance value of the amorphous layer 12 after crystallization is the lowest. In addition, FIG. 4 shows a case where the tin oxide content of tin in terms of oxide is 2% by mass, 3% by mass, 5% by mass, 7% by mass, 8.8% by mass, 10% by mass, and 12% by mass. Further, the film formation conditions are basically set to be the same as the above conditions. For example, in tin in terms of oxide When the tin oxide content is 3% by mass, the flow rate when the sheet resistance value after crystallization is the lowest value is 1.0% by volume. Further, in the case of 10% by mass, the flow rate was 1.4% by volume.

The conductive film laminate 20 can be produced by heat-treating the above-mentioned conductive film material 10. That is, the amorphous layer 12 is crystallized by heat treatment, whereby a crystalline transparent conductive film, that is, a crystalline layer 21 can be obtained. The heat treatment is preferably carried out in the atmosphere at 100 to 150 ° C for 30 to 180 minutes. When the heat treatment temperature is set to 100 ° C or higher and the heat treatment time is set to 30 minutes or more, the amorphous layer 12 can be effectively crystallized. In addition, when the heat treatment temperature is set to 150° C. or less and the heat treatment time is set to 180 minutes or less, crystallization can be sufficiently performed, and when it is 150° C. or less and 180 minutes or less, damage to the transparent substrate 11 or the like can be suppressed. Improve productivity.

Example

The embodiments of the present invention will be specifically described below by way of examples. Sample Nos. 6, 8, and 10 to 12 are examples of the present invention, and Sample Nos. 1 to 5, 7, 9, and 13 to 18 are comparative examples of the present invention. However, the invention is not limited by the embodiments.

The film thickness of the amorphous layer is a value obtained from optical characteristics, sputtering deposition rate, and sputtering time. In other words, the thickness of the amorphous layer produced by the same sputtering deposition rate and sputtering conditions used in the preparation of the sample was measured by a film thickness meter, and film formation per unit time at the sputtering time was determined in advance. The film thickness was calculated from the sputtering time in the preparation of the sample. However, the film thickness is a geometric thickness.

The production of samples No. 1 to No. 18 was carried out as follows.

Formed as a bottom layer on a PET film having a thickness of 100 μm on a transparent substrate A film of SiOx (x is 1.5 to 2) having a thickness of 32 angstroms. In the SiOx film, a boron-doped polycrystalline ruthenium target was used, and a mixed gas of 11% by volume of oxygen mixed with argon gas was introduced, and an AC magnetron sputtering was performed under a pressure of 3.7 Pa to form a film. Further, the thickness adjustment of the SiOx film is performed by adjusting the power density and the sputtering time.

In the film formation step of the amorphous layer, a target material composed of indium tin oxide is used on the PET film on which the SiOx film is formed, and a mixed gas of argon gas and oxygen gas is introduced at a predetermined ratio while being 0.8. DC magnetron sputtering is performed under a pressure of Pa to form an amorphous layer, and a material for a conductive film is produced. The indium tin oxide contains a predetermined amount of tin in terms of oxide.

The film formation conditions of the amorphous layer are shown in detail in Table 1. The target is a sintered product obtained by mixing and sintering tin oxide (SnO ₂ ) and indium oxide (In ₂ O ₃ ), and the content of tin (tin oxide content) in terms of oxide is 3 to 12% by mass. The oxygen flow rate is obtained by previously obtaining the flow rate when the sheet resistance value after crystallization is the lowest value, and adjusting the flow rate. The film thickness adjustment of the amorphous layer is performed by adjusting the power density and the sputtering time. On the other hand, it is presumed that the content of tin in the amorphous layer in terms of oxide is the same as the content of tin in the target in terms of oxide.

In the heat treatment step of the amorphous layer, a conductive film laminate was produced by subjecting the obtained material for a conductive film to heat treatment at 145 ° C for 60 minutes in the air.

For each of the conductive film laminates of Sample Nos. 1 to No. 18 produced by using a target containing tin oxide as described in Table 1, the sheet resistance (Ω/□) and amorphous were measured. The measurement results of the film thickness (Å) of the layer and the evaluation of the crystallinity of the amorphous layer are shown in Table 1.

(sheet resistance value)

Each of the conductive film laminates was cut into a size of 100 mm × 100 mm, and a sheet resistance value (Ω/□, that is, Ω/square) was measured by a four-probe method using Lorester (manufactured by Mitsubishi Chemical Corporation).

(crystallinity)

Each of the conductive film laminates was immersed in a HCl solution (concentration: 1.5 mol/L) at 25 ° C for about 3 minutes, and the resistance value was measured, and the resistance value change rate (resistance value after immersion/resistance value before immersion) was determined. . Further, as described above, the rate of change in resistance value is an index of crystallinity, and the rate of change in resistance value is 200% or less. In the table, those whose resistance value change rate is 200% or less are indicated by "○", and those exceeding 200% are indicated by "×".

When the content of tin is less than 5.5% by mass in terms of oxide, even if the film thickness is reduced to 25 nm (250 angstroms) or less, the crystallinity during heat treatment is good, but the sheet resistance value after heat treatment (after crystallization) The punching height is over 150Ω/□. On the other hand, when the content of tin is more than 9% by mass in terms of oxide, the film thickness is more than 25 nm, and the crystallinity at the time of heat treatment is good, and the sheet resistance value after heat treatment can be sufficiently low enough to be 150 Ω/□ or less. However, the transmittance is low; the crystallinity of the film thickness of 25 nm or less is insufficient when heat treatment, and the sheet resistance after heat treatment is also higher than 150 Ω/□. When the content of tin in terms of oxide is 5.5 to 9% by mass, the film thickness is reduced to 25 nm or less, and heat treatment is performed. The crystallinity is still good, and the sheet resistance value after the heat treatment can also obtain a sufficiently low value of 150 Ω/□ or less.

Industrial availability

According to the present invention, a conductive film laminate having a sheet resistance having a low sheet resistance and an increased film thickness can be obtained, and the conductive film laminate can be used as an electronic device, and can be effectively used as a large touch. The conductive film laminate of the panel device is used.

The entire disclosure of Japanese Patent Application No. 2012-111677, filed on-

10‧‧‧Material for conductive film

11‧‧‧Transparent substrate

12‧‧‧Amorphous layer

Claims (8)

A material for a conductive film, comprising a transparent substrate and an amorphous layer, wherein the amorphous layer is made of indium tin oxide laminated on the transparent substrate; and the material for the conductive film is characterized by: The crystal layer is composed of indium tin oxide containing 5.5 to 9% by mass of tin in terms of oxide, and has a sheet thickness of 15 to 25 nm and crystallized to have a sheet resistance of 50 to 150 Ω/□. The material for a conductive film according to claim 1, wherein the amorphous layer is made of indium tin oxide containing more than 6% by mass of tin in terms of oxide. A conductive film laminate comprising a transparent substrate and a crystalline layer, wherein the crystalline layer is composed of indium tin oxide laminated on the transparent substrate; and the conductive film laminate is characterized by: The layer is composed of indium tin oxide containing 5.5 to 9% by mass of tin in terms of oxide, and has a film thickness of 15 to 25 nm and a sheet resistance of 50 to 150 Ω/□. The conductive film laminate according to claim 3, wherein the crystal layer is composed of indium tin oxide containing more than 6% by mass of tin in terms of oxide. An electronic machine characterized by having a conductive film laminate as claimed in claim 3 or 4. A method for producing a material for a conductive film, characterized by having a film forming step of using a sputtering target and sputtering on a transparent substrate When the amorphous layer is formed, the sputtering target is made of indium tin oxide containing 5.5 to 9% by mass of tin in terms of oxide, and the thickness of the amorphous layer is 15 to 25 nm. The sheet resistance after crystallization is 50 to 150 Ω/□. A method for producing a conductive film laminate, comprising the steps of: forming a film by using a sputtering target and forming an amorphous layer on a transparent substrate by sputtering; In the material, the sputtering target is made of indium tin oxide containing 5.5 to 9% by mass of tin in terms of oxide, and the thickness of the amorphous layer is 15 to 25 nm and the sheet resistance is crystallized. The value is 50 to 150 Ω/□; and the heat treatment step is performed by heat-treating the conductive film with a material to crystallize the amorphous layer to form a crystal layer. The method for producing a conductive film laminate according to claim 7, comprising the steps of: forming a film by using a sputtering target and forming an amorphous layer on the transparent substrate by sputtering to obtain a conductive film. In the film material, the sputtering target is made of indium tin oxide containing 5.5 to 9% by mass of tin in terms of oxide, and the thickness of the amorphous layer is 15 to 25 nm and crystallized. a sheet resistance value of 50 to 150 Ω/□; a step of patterning an amorphous layer of the material for the conductive film by etching; and a heat treatment step of heat-treating the patterned conductive film with the material to form the amorphous material The layer is crystallized to form a crystalline layer.