Conductive film

Abstract

To provide a conductive film having excellent specific resistance while capable of preventing outgas from an organic resin base material from contacting with a copper layer.SOLUTION: There is provided a conductive film 1 which has an organic resin base material 2, an inorganic layer 3 disposed on one side in the thickness direction of the organic resin base material 2 and a copper layer 4 directly disposed on one surface in the thickness direction of the inorganic layer, wherein in the copper layer 4 near the inorganic layer 3, the elemental concentration of O is 1.4 atom% or more and 15 atom% or less based on the sum of Cu, O and inorganic elements derived from the inorganic layer 3, as measured by energy dispersive X-ray analysis (EDX).SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a conductive film. [Background technology]

[0002] A conductive film having a substrate and a metal layer in this order has been known. Such a conductive film is used as a conductor layer for forming an electrode pattern in various devices such as flat panel displays and touch panels.

[0003] Such a conductive film is produced, for example, by disposing a metal layer on one surface in the thickness direction of a substrate by a sputtering method.

[0004] On the other hand, in the manufacturing of the conductive film described above, outgassing may occur from the substrate. Such outgassing may cause metal oxide to be formed on the other side of the metal layer in the thickness direction. This may result in a problem of reduced adhesion between the substrate and the metal layer.

[0005] In response to this, a conductive film having a barrier layer (inorganic layer) between the substrate and the metal layer has been studied. The barrier layer can prevent outgassing from the substrate from coming into contact with the metal layer, thereby resolving the above-mentioned problems.

[0006] As such a conductive film, a conductive film containing a resin film, an inorganic layer, and a copper layer in this order has been proposed (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2017-100368 A Summary of the Invention [Problem to be solved by the invention]

[0008] On the other hand, providing a barrier layer has the drawback of increasing the resistivity of the metal layer (copper layer).

[0009] The present invention provides a conductive film that is excellent in resistivity while preventing outgassing from an organic resin substrate from coming into contact with a copper layer. [Means for solving the problem]

[0010] The present invention [1] includes a conductive film comprising an organic resin substrate, an inorganic layer disposed on one side of the organic resin substrate in a thickness direction, and a copper layer disposed directly on one surface of the inorganic layer in the thickness direction, wherein the copper layer adjacent to the inorganic layer has an elemental concentration of O of 1.4 atomic % or more and 15 atomic % or less relative to the total of Cu, O, and inorganic elements derived from the inorganic layer, as measured by energy dispersive X-ray analysis (EDX).

[0011] The present invention [2] includes the conductive film according to the above [1], in which the copper layer has a thickness of 50 nm or more.

[0012] The present invention [3] includes the conductive film according to the above [1] or [2], in which the thickness of the copper layer is 300 nm or less.

[0013] The present invention [4] includes the conductive film according to any one of the above [1] to [3], wherein the inorganic layer has a thickness of 2 nm or more and 15 nm or less. Effect of the Invention

[0014] The conductive film of the present invention includes an inorganic layer. Therefore, during the production of the conductive film, outgas from the organic resin substrate can be prevented from contacting the copper layer. As a result, the adhesion between the organic resin substrate and the copper layer can be prevented from decreasing.

[0015] Moreover, in the conductive film of the present invention, the elemental concentration of O in the copper layer near the inorganic layer is 1.4 atomic % or more and 15 atomic % or less relative to the total of Cu, O, and inorganic elements derived from the inorganic layer, as measured by energy dispersive X-ray analysis (EDX), thereby making it possible to reduce the resistivity of the copper layer. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 shows one embodiment of the conductive film of the present invention. [Diagram 2] 2A to 2C show one embodiment of a method for producing a conductive film. Fig. 2A shows a first step of preparing an organic resin substrate. Fig. 2B shows a second step of disposing an inorganic layer on one surface in the thickness direction of the organic resin substrate. Fig. 2C shows a third step of disposing a copper layer on one surface in the thickness direction of the inorganic layer. [Diagram 3] FIG. 3 shows data obtained in Example 3 by measuring element concentrations of Cu, O, and inorganic elements derived from the inorganic layer in one thickness direction from the organic resin substrate to the copper layer by energy dispersive X-ray analysis (EDX). [Figure 4] FIG. 4 is a graph of the data from FIG. [Diagram 5] FIG. 5 shows data obtained in Comparative Example 1 by measuring element concentrations of Cu, O, and inorganic elements derived from the inorganic layer in one thickness direction from the organic resin substrate to the copper layer by energy dispersive X-ray analysis (EDX). [Figure 6] FIG. 6 is a graph of the data from FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] 1.Conductive film One embodiment of the conductive film of the present invention will be described with reference to FIG.

[0018] In FIG. 1, the up-down direction of the paper is the up-down direction (thickness direction). The upper side of the paper is the top side (one side in the thickness direction). The lower side of the paper is the bottom side (the other side in the thickness direction). The left-right direction and the depth direction of the paper are surface directions perpendicular to the up-down direction. Specifically, they follow the directional arrows in each figure.

[0019] The conductive film 1 has a film shape (including a sheet shape) with a predetermined thickness. The conductive film 1 extends in a plane direction perpendicular to the thickness direction. The conductive film 1 has a flat upper surface and a flat lower surface.

[0020] 1, the conductive film 1 includes an organic resin base material 2, an inorganic layer 3 disposed on one side in the thickness direction of the organic resin base material 2, and a copper layer 4 disposed directly on one surface in the thickness direction of the inorganic layer 3. Specifically, the conductive film 1 includes the organic resin base material 2, the inorganic layer 3 disposed directly on the upper surface (one surface in the thickness direction) of the organic resin base material 2, and the copper layer 4 disposed directly on the upper surface (one surface in the thickness direction) of the inorganic layer 3.

[0021] The conductive film 1 has a thickness of, for example, 1 μm or more, preferably 5 μm or more, and for example, 300 μm or less, preferably 200 μm or less.

[0022] <Organic resin base material> The organic resin base material 2 has a film shape. The organic resin base material 2 is flexible. The organic resin base material 2 is disposed on the entire lower surface of the inorganic layer 3 so as to be in contact with the lower surface of the inorganic layer 3. The organic resin base material 2 is the lowermost layer of the conductive film 1.

[0023] The organic resin substrate 2 may be, for example, a polymer film.

[0024] Examples of materials for the polymer film include polyester resin, (meth)acrylic resin, olefin resin, polycarbonate resin, polyethersulfone resin, polyarylate resin, melamine resin, polyamide resin, polyimide resin, cellulose resin, and polystyrene resin, and preferably polyester resin.

[0025] Examples of polyester resins include polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, and preferably polyethylene terephthalate.

[0026] An example of the (meth)acrylic resin is polymethyl methacrylate.

[0027] Examples of olefin resins include polyethylene, polypropylene, and cycloolefin polymers.

[0028] An example of the cellulose resin is triacetyl cellulose.

[0029] The thickness of the organic resin base material 2 is, for example, 1 μm or more, preferably 5 μm or more, more preferably 10 μm or more, even more preferably 50 μm or more, particularly preferably 100 μm or more, and for example, 300 μm or less, preferably 200 μm or less, more preferably 150 μm or less.

[0030] The thickness of the organic resin base material 2 can be measured using a dial gauge (manufactured by PEACOCK, "DG-205").

[0031] Moreover, the organic resin substrate 2 preferably has transparency. Specifically, the total light transmittance (JIS K 7375-2008) of the organic resin substrate 2 is, for example, 80% or more, or preferably 85% or more.

[0032] <Inorganic layer> The inorganic layer 3 is a layer for preventing outgassing from the organic resin substrate 2 from coming into contact with the copper layer 4 in the method for producing the conductive film 1 described below.

[0033] The inorganic layer 3 has a film shape. The inorganic layer 3 is disposed on the entire upper surface of the organic resin base material 2 so as to be in contact with the upper surface of the organic resin base material 2. The inorganic layer 3 is disposed on the entire lower surface of the copper layer 4 so as to be in contact with the lower surface of the copper layer 4.

[0034] Furthermore, the inorganic layer 3, which will be described in detail later, is a sputtered layer since it is formed by a sputtering method.

[0035] The material of the inorganic layer 3 is not particularly limited as long as it is an inorganic substance other than copper as a pure metal. Specifically, preferred materials for the inorganic layer 3 include metals (excluding copper as a pure metal) and metal oxides (excluding copper oxide).

[0036] Examples of metals include Ni, In, Sn, Zn, Ga, Sb, Ti, Si, Zr, Mg, Al, Au, Ag, Pd, W, alloys thereof, and alloys of these with copper.

[0037] Examples of the metal oxide include oxides of the above metals. As the metal oxide, preferably, an indium-containing oxide is used. As the indium-containing oxide, for example, an indium tin composite oxide (ITO) is used.

[0038] The metal oxide may be either crystalline or amorphous.

[0039] A preferred example of the material for the inorganic layer 3 is a metal oxide.

[0040] The materials for the inorganic layer 3 can be used alone or in combination of two or more kinds.

[0041] The thickness of the inorganic layer 3 is, for example, 2 nm or more from the viewpoint of gas barrier properties, and, for example, 15 nm or less, preferably 10 nm or less, more preferably 7 nm or less from the viewpoint of processability.

[0042] The thickness of the inorganic layer 3 can be measured by observing a cross section of the conductive film 1 using, for example, a transmission electron microscope.

[0043] <Copper layer> The copper layer 4 is a conductor layer and is formed into a desired pattern as necessary.

[0044] The copper layer 4 has a film shape. The copper layer 4 is disposed over the entire upper surface of the inorganic layer 3 so as to be in contact with the upper surface of the inorganic layer 3. The copper layer 4 is the uppermost layer of the conductive film 1.

[0045] Furthermore, although details will be described later, the copper layer 4 is a sputtered layer since it is formed by a sputtering method.

[0046] Examples of materials for the copper layer 4 include copper (copper as a pure metal) and copper alloys.

[0047] The metals constituting the copper alloy are not particularly limited, but examples thereof include silver, tin, chromium, and zirconium.

[0048] From the viewpoint of electrical conductivity, copper (copper as a pure metal) is preferably used as the material of the copper layer 4. That is, the copper layer 4 is preferably made of copper (copper as a pure metal).

[0049] The resistivity of the copper layer 4 is, for example, 2.300×10 -8 Ω·m or less, preferably 2.280×10 -8 Ω·m or less, more preferably 2.200×10 -8 Ω·m or less, typically 1.000×10 -8 It is greater than or equal to Ω·m.

[0050] The resistivity can be calculated by multiplying the surface resistance value measured by a four-terminal method in accordance with JIS K7194 by the thickness of the copper layer 4.

[0051] The surface resistance value of the copper layer 4 is, for example, 0.222 Ω / □ or less, preferably 0.220 Ω / □ or less, and more preferably 0.210 Ω / □ or less.

[0052] There is no particular lower limit to the surface resistance value of the copper layer 4. For example, the surface resistance value of the copper layer 4 is usually more than 0 Ω / □.

[0053] The surface resistance value can be measured by a four-terminal method in accordance with JIS K7194.

[0054] The thickness of the copper layer 4 is, for example, from the viewpoint of resistance value, 50 nm or more, preferably 70 nm or more, more preferably 90 nm or more, and even more preferably 100 nm or more, and, for example, from the viewpoint of productivity, 300 nm or less, preferably 250 nm or less, more preferably 200 nm or less, even more preferably 150 nm or less, and particularly preferably 120 nm or less.

[0055] In the copper layer 4 near the inorganic layer 3, the element concentration of O relative to the sum of Cu (copper element), O (oxygen element), and inorganic elements derived from the inorganic layer 3, as measured by energy dispersive X-ray analysis (EDX), is 1.4 atomic % or more, preferably 2.0 atomic % or more, more preferably 2.5 atomic % or more, even more preferably 3.0 atomic % or more, particularly preferably 4.0 atomic % or more, and is 15 atomic % or less, preferably 10 atomic % or less, more preferably 7 atomic % or less, and even more preferably 5 atomic % or less.

[0056] The method and conditions for measuring element concentrations by energy dispersive X-ray analysis (EDX) will be described in detail in the Examples below.

[0057] The copper layer 4 near the inorganic layer 3 is the copper layer 4 at the first point in time when the elemental concentrations of Cu, O, and inorganic elements derived from the inorganic layer 3 are measured in one thickness direction from the organic resin substrate 2 to the copper layer 4 using energy dispersive X-ray analysis (EDX) and the elemental concentration of Cu relative to the sum of Cu, O, and inorganic elements derived from the inorganic layer 3 becomes 50 atomic % or more and the elemental concentration of the inorganic elements relative to the sum of Cu and the inorganic elements derived from the inorganic layer 3 becomes 1 atomic % or less.

[0058] In the copper layer 4 near the inorganic layer 3, if the element concentration of O relative to the total of Cu, O, and inorganic elements derived from the inorganic layer 3 measured by energy dispersive X-ray analysis (EDX) is within the above-mentioned range, the copper layer 4 has excellent resistivity.

[0059] 2. Manufacturing method of conductive film A method for producing the conductive film 1 will be described with reference to FIGS. 2A to 2C.

[0060] The method for producing the conductive film 1 includes a first step of preparing an organic resin substrate 2, a second step of disposing an inorganic layer 3 on one surface in the thickness direction of the organic resin substrate 2 by a sputtering method, and a third step of disposing a copper layer 4 on one surface in the thickness direction of the inorganic layer 3 by a sputtering method. In this method, each layer is disposed in order, for example, by a roll-to-roll method. In such a case, the conveying speed is, for example, 1.0 m / min or more and, for example, 20.0 m / min or less.

[0061] In the method for producing the conductive film 1, in the second and third steps, a sputtering method is carried out while supplying a sputtering gas.

[0062] In the method for producing the conductive film 1, for example, an inert gas (described later) is supplied as the sputtering gas in the second step. Preferably, in the second step, an inert gas (described later) and oxygen gas are supplied as the sputtering gas.

[0063] In the method for producing the conductive film 1, in the third step, sputtering is performed multiple times by appropriately setting the target material, sputtering conditions, and the like, in order to form the desired copper layer 4. In the third step, the number of sputtering times is, for example, two or more times, preferably four or more times, and for example, 20 times or less, preferably 10 times or less.

[0064] In the method for producing the conductive film 1, for example, an inert gas (described later) is supplied as the sputtering gas in the third step. Preferably, in the first sputtering in the third step, an inert gas (described later) and oxygen gas are supplied as the sputtering gas, and in the second and subsequent sputtering in the third step, only an inert gas (described later) is supplied as the sputtering gas.

[0065] That is, in the manufacturing method of the conductive film 1, for example, in the second step, oxygen gas is supplied together with an inert gas by a sputtering method to arrange the inorganic layer 3 on one surface in the thickness direction of the organic resin substrate 2, and in the third step, only an inert gas is supplied by a sputtering method to arrange the copper layer 4 on one surface in the thickness direction of the inorganic layer 3. Also, for example, in the second step, only an inert gas is supplied by a sputtering method to arrange the inorganic layer 3 on one surface in the thickness direction of the organic resin substrate 2, and in the third step, oxygen gas is supplied together with an inert gas in the first sputtering, and only an inert gas is supplied in the second and subsequent sputtering, to arrange the copper layer 4 on one surface in the thickness direction of the inorganic layer 3. Furthermore, for example, in the second step, oxygen gas is supplied together with an inert gas by a sputtering method to form an inorganic layer 3 on one surface in the thickness direction of the organic resin substrate 2, and in the third step, oxygen gas is supplied together with an inert gas by a sputtering method in the first sputtering and only inert gas is supplied in the second and subsequent sputtering to form a copper layer 4 on one surface in the thickness direction of the inorganic layer 3. Preferably, in the method for producing the conductive film 1, in the second step, oxygen gas is supplied together with an inert gas by a sputtering method to form an inorganic layer 3 on one surface in the thickness direction of the organic resin substrate 2, and in the third step, oxygen gas is supplied together with an inert gas by a sputtering method in the first sputtering and only inert gas is supplied in the second and subsequent sputtering to form a copper layer 4 on one surface in the thickness direction of the inorganic layer 3.

[0066] In the following, a method for producing the conductive film 1 will be described in detail.

[0067] [1st step] In the first step, as shown in FIG. 2A, an organic resin substrate 2 is prepared.

[0068] [Second process] In the second step, as shown in FIG. 2B, an inorganic layer 3 is disposed on one surface in the thickness direction of the organic resin substrate 2 by a sputtering method.

[0069] To dispose the inorganic layer 3 on one surface in the thickness direction of the organic resin substrate 2 by a sputtering method, first, if necessary, one surface in the thickness direction of the organic resin substrate 2 is subjected to a surface treatment.

[0070] Examples of the surface treatment include corona treatment, plasma treatment, flame treatment, ozone treatment, primer treatment, glow treatment, and saponification treatment.

[0071] Next, in the sputtering method, a target (material for the inorganic layer 3) and the organic resin substrate 2 are placed facing each other in a vacuum chamber of a sputtering deposition apparatus. Next, a sputtering gas is supplied and a voltage is applied from a power source to accelerate gas ions and irradiate the target, thereby ejecting the target material from the target surface. The target material is then deposited on the surface (one surface in the thickness direction) of the organic resin substrate 2 to form the inorganic layer 3.

[0072] As the sputtering gas, for example, only an inert gas (for example, argon gas) is supplied, or an inert gas and an oxygen gas are supplied. Preferably, an inert gas and an oxygen gas are supplied as the sputtering gas.

[0073] When oxygen gas is supplied together with an inert gas, the flow rate is, for example, 5 sccm or more, preferably 10 sccm or more, more preferably 20 sccm or more, even more preferably 30 sccm or more, particularly preferably 40 sccm or more, and for example, 200 sccm or less, preferably 100 sccm or less.

[0074] In addition, when oxygen gas is supplied together with an inert gas, the flow rate ratio of the inert gas to the oxygen gas is, for example, 3.5 or more, preferably 10 or more, and for example, 200 or less, preferably 100 or less, more preferably 50 or less, and even more preferably 30 or less.

[0075] The air pressure during sputtering is, for example, 0.1 Pa or more, preferably 0.2 Pa or more, and for example, 2.0 Pa or less, preferably 1.0 Pa or less.

[0076] The power source may be, for example, a DC power source, an AC power source, an MF power source, or an RF power source, or may be a combination of these.

[0077] The discharge output is, for example, 1.0 kW or more, preferably 5.0 kW or more, and for example, 20 kW or less.

[0078] In this way, the inorganic layer 3 is disposed on one surface of the organic resin base material 2 in the thickness direction.

[0079] [3rd step] In the third step, as shown in FIG. 2C, a copper layer 4 is disposed on one surface in the thickness direction of the inorganic layer 3 by sputtering.

[0080] In the sputtering method, a target (material of the copper layer 4) and the inorganic layer 3 are placed facing each other in a vacuum chamber of a sputtering deposition apparatus. Next, a sputtering gas is supplied and a voltage is applied from a power source to accelerate gas ions and irradiate the target, displacing the target material from the target surface. The target material is then deposited on the surface (one surface in the thickness direction) of the inorganic layer 3 to form the copper layer 4.

[0081] In the third step, sputtering is performed multiple times by appropriately setting the target material, sputtering conditions, and the like, in order to form the desired copper layer 4. In the third step, the number of sputtering times is, for example, 2 or more, preferably 4 or more, and for example, 20 or less, preferably 10 or less.

[0082] Also, as the sputtering gas, for example, only an inert gas (for example, argon gas) is supplied, or an inert gas and an oxygen gas are supplied. More specifically, as the sputtering gas, for example, only an inert gas is supplied in all sputterings, or an inert gas and an oxygen gas are supplied in the first sputtering, and only an inert gas is supplied in the second and subsequent sputterings. Preferably, as the sputtering gas, an inert gas and an oxygen gas are supplied in the first sputtering, and only an inert gas is supplied in the second and subsequent sputterings.

[0083] When oxygen gas is supplied together with the inert gas, the flow rate thereof is lower than the flow rate of the oxygen gas in the second step described above, and is, for example, 1 sccm or more, preferably 3 sccm or more, more preferably 5 sccm or more, and for example, 30 sccm or less, preferably 20 sccm or less, more preferably 15 sccm or less.

[0084] In addition, when oxygen gas is supplied together with an inert gas, the flow rate ratio of the inert gas to the oxygen gas is, for example, 20 or more, preferably 40 or more, and for example, 500 or less, preferably 200 or less, more preferably 100 or less, and even more preferably 50 or less.

[0085] The air pressure during sputtering is, for example, 0.1 Pa or more, preferably 0.2 Pa or more, and for example, 2.0 Pa or less, preferably 1.0 Pa or less.

[0086] The power source may be, for example, a DC power source, an AC power source, an MF power source, or an RF power source, or may be a combination of these.

[0087] The discharge output is, for example, 5.0 kW or more, preferably 10.0 kW or more, and for example, 20 kW or less.

[0088] The film formation temperature (the temperature of the organic resin substrate 2 on which the inorganic layer 3 is disposed) is, for example, 30° C. or higher and, for example, 60° C. or lower.

[0089] As a result, the copper layer 4 is formed on one surface of the inorganic layer 3 in the thickness direction.

[0090] In the copper layer 4 thus formed, in the copper layer 4 near the inorganic layer 3, the elemental concentration of O relative to the total of Cu, O, and inorganic elements originating from the inorganic layer 3, as measured by energy dispersive X-ray analysis (EDX), is 1.4 atomic % or more and 15 atomic % or less.

[0091] In this manner, the conductive film 1 is manufactured.

[0092] <Action and effect> The conductive film 1 includes the inorganic layer 3. Therefore, during the production of the conductive film 1, outgassing from the organic resin base material 2 can be prevented from coming into contact with the copper layer 4.

[0093] Specifically, in the production of the conductive film 2, outgassing may occur from the organic resin base material 2. Such outgassing may cause copper oxide to form on the other surface in the thickness direction of the copper layer 4. This may result in a decrease in adhesion between the organic resin base material 2 and the copper layer 4.

[0094] On the other hand, the conductive film 1 includes the inorganic layer 3. This can prevent the outgas from coming into contact with the copper layer 4. This can prevent copper oxide from being formed on the other surface in the thickness direction of the copper layer 4, and as a result, can prevent the adhesion between the organic resin base material 2 (inorganic layer 3) and the copper layer 4 from decreasing.

[0095] Furthermore, in the copper layer 4 of the conductive film 1, the element concentration of O in the copper layer 4 near the inorganic layer 3 is 1.4 atomic % or more and 15 atomic % or less with respect to the total of Cu, O, and inorganic elements derived from the inorganic layer 3, as measured by energy dispersive X-ray analysis (EDX). Therefore, the specific resistance of the copper layer 4 can be reduced.

[0096] <Modification> In the modified example, the same reference numerals are used for the same components and steps as those in the first embodiment, and detailed descriptions thereof will be omitted. In addition, the modified example can achieve the same effects as those in the first embodiment, unless otherwise specified. Furthermore, the first embodiment and its modified example can be appropriately combined.

[0097] In the above description, the conductive film 1 includes the organic resin substrate 2, the inorganic layer 3, and the copper layer 4 in this order in the thickness direction, but a functional layer (e.g., a hard coat layer) can be disposed between the organic resin substrate 2 and the inorganic layer 3. In such a case, the conductive film 1 includes the organic resin substrate 2, the hard coat layer, the inorganic layer 3, and the copper layer 4 in this order in the thickness direction. EXAMPLES

[0098] The present invention will be described in more detail below with reference to examples and comparative examples. The present invention is not limited to the examples and comparative examples. The specific numerical values ​​of the blending ratio (content ratio), physical property values, parameters, etc. used in the following description can be replaced with the upper limit values ​​(numerical values ​​defined as "less than or equal to" or "less than") or lower limit values ​​(numerical values ​​defined as "more than or equal to" or "exceeding") of the corresponding blending ratio (content ratio), physical property values, parameters, etc. described in the above "Form for carrying out the invention".

[0099] <Conductive film manufacturing> Example 1 A conductive film was produced by the following procedure.

[0100] [1st step] As an organic resin substrate, polyethylene terephthalate (125U48, manufactured by Toray Industries, Inc., thickness 125 μm) was prepared.

[0101] [Second process] An inorganic layer (ITO layer) (thickness 5 nm) was disposed on one surface in the thickness direction of the organic resin substrate by a sputtering method under the following conditions.

[0102] {conditions} Equipment: Roll-to-roll sputtering deposition equipment (roll-to-roll DC magnetron sputtering equipment) Material of inorganic layer: ITO Gas: argon gas and oxygen gas (oxygen gas flow rate 20sccm) Flow rate ratio of inert gas to oxygen gas: 35 Discharge output: 7.2kW Pressure in the deposition chamber: 0.4 Pa Travel speed: 8.0m / min

[0103] [3rd step] A copper layer (104 nm) was formed on one surface of the inorganic layer in the thickness direction by sputtering under the following conditions: Sputtering was repeated eight times until the desired thickness was achieved.

[0104] {conditions} Equipment: Roll-to-roll sputtering deposition equipment (roll-to-roll DC magnetron sputtering equipment) Gas: Argon gas Discharge output: 14.7kW Pressure in the deposition chamber: 0.4 Pa Film forming temperature: 40℃ Travel speed: 8.0m / min

[0105] After the sputtering in the second step, the first sputtering in the third step was carried out consecutively.

[0106] Example 2 A conductive film was produced based on the same procedure as in Example 1. However, based on the description in Table 1, the flow rate of oxygen gas in the second step was changed.

[0107] Example 3 The conductive film was produced in the first and second steps using the same procedures as in Example 2, and in the third step using the following procedure.

[0108] [3rd step] A copper layer (thickness 12 nm) was disposed on one surface of the inorganic layer in the thickness direction by a sputtering method under the following conditions: Sputtering was performed only once.

[0109] {conditions} Equipment: Roll-to-roll sputtering deposition equipment (roll-to-roll DC magnetron sputtering equipment) Gas: Argon gas and oxygen gas (oxygen gas flow rate 15sccm) Flow rate ratio of inert gas to oxygen gas: 47 Discharge output: 14.7kW Pressure in the deposition chamber: 0.4 Pa Film forming temperature: 40℃ Travel speed: 8.0m / min

[0110] After the sputtering in the second step, the first sputtering in the third step was carried out consecutively.

[0111] A copper layer (thickness 92 nm) was then deposited by sputtering under the following conditions: Sputtering was repeated seven times until the desired thickness was achieved.

[0112] {conditions} Equipment: Roll-to-roll sputtering deposition equipment (roll-to-roll DC magnetron sputtering equipment) Gas: Argon gas Discharge output: 14.7kW Pressure in the deposition chamber: 0.4 Pa Film forming temperature: 40℃ Travel speed: 8.0m / min

[0113] Comparative Example 1 A conductive film was produced based on the same procedure as in Example 1. However, the flow rate of oxygen gas was changed based on the description in Table 1. Specifically, oxygen gas was not supplied in the second step.

[0114] Comparative Example 2 A conductive film was produced based on the same procedure as in Example 3. However, the flow rate of oxygen gas was changed based on the description in Table 1. Specifically, in the third step, the flow rate of oxygen gas was set to 100 sccm (flow rate ratio of the inert gas to the oxygen gas: 7).

[0115] <Evaluation> (Surface resistance) The surface resistance of the copper layer of each of the examples and comparative examples was measured by a four-terminal method in accordance with JIS K7194. The results are shown in Table 1.

[0116] (specific resistance) The resistivity of the copper layer in each of the examples and comparative examples was calculated by multiplying the surface resistivity by the thickness of the copper layer. The results are shown in Table 1.

[0117] (O element concentration) In each example and each comparative example, a sample was prepared by using a focused ion beam device (FIB) using a microsampling method. The device and conditions used for preparation are shown below. Next, the cross section of the prepared sample was observed using a field emission analytical transmission electron microscope (FE-TEM), and then the element concentrations of Cu, O, and inorganic elements derived from the inorganic layer were measured in one thickness direction from the organic resin substrate by energy dispersive X-ray analysis (EDX). The device and conditions used for observation and measurement are shown below. Table 1 shows the element concentration of O relative to the total of Cu, O, and inorganic elements derived from inorganic layer 3 in the copper layer near the inorganic layer. In addition, data and graphs of the element concentrations of Cu, O, and inorganic elements derived from the inorganic layer measured in one thickness direction from the organic resin substrate by energy dispersive X-ray analysis (EDX) in Example 3 and Comparative Example 1 are shown in Figures 3 to 6.

[0118] {Equipment and conditions} FIB (FB2200, Hitachi), accelerating voltage: 10 to 40 kV FE-TEM (JEM-2800, JEOL), accelerating voltage: 200 kV EDX (detector: JED-2300T (SD100GV), manufactured by JEOL), (analyzer: NORAN System7, manufactured by Thermo Fisher Scientific), (analysis software: NSS, manufactured by Thermo Fisher Scientific)

[0119] <Consideration> It is understood that Examples 1 to 3 and Comparative Example 1 and Comparative Example 2 each include an inorganic layer, and therefore can prevent outgassing from the organic resin substrate from coming into contact with the copper layer.

[0120] FIG. 3 shows data obtained by measuring the elemental concentrations of Cu, O, and inorganic elements derived from the inorganic layer in one thickness direction from the organic resin substrate to the copper layer in Example 3, and FIG. 4 shows a graph thereof. Since the elemental concentration of the inorganic element increases when the moving distance in one thickness direction from the organic resin substrate is 13.2 μm, it can be confirmed that the organic resin substrate is switched to the inorganic layer. Furthermore, since the elemental concentration of Cu increases when the moving distance in one thickness direction from the organic resin substrate is 23.1 μm, it can be confirmed that the inorganic layer is switched to the copper layer.

[0121] The copper layer near the inorganic layer is the copper layer at the first time when the elemental concentration of Cu becomes 50 atomic % or more with respect to the sum of Cu, O, and inorganic elements derived from the inorganic layer, and the elemental concentration of inorganic elements becomes 1 atomic % or less with respect to the sum of Cu and inorganic elements derived from the inorganic layer. In Example 3, as shown in FIG. 3, when the moving distance in one thickness direction from the organic resin substrate is 26.4 μm, the elemental concentration of Cu becomes 94.8 atomic % with respect to the sum of Cu, O, and inorganic elements derived from the inorganic layer, and the elemental concentration of inorganic elements becomes 0.54 atomic % with respect to the sum of Cu and inorganic elements derived from the inorganic layer, and the above-mentioned condition is satisfied for the first time, so that it becomes a copper layer near the inorganic layer. In other words, the elemental concentration of O with respect to the sum of Cu, O, and inorganic elements derived from the inorganic layer with respect to the moving distance in one thickness direction from the organic resin substrate is 26.4 μm is the elemental concentration of O of the copper layer near the inorganic layer in Example 3, which is 4.69 atomic %.

[0122] Similarly, in Comparative Example 1, as shown in FIG. 5, when the moving distance in one direction in the thickness direction from the organic resin substrate is 33.1 μm, the element concentration of Cu is 98.05 atomic % with respect to the sum of Cu, O, and inorganic elements derived from the inorganic layer, and the element concentration of inorganic atoms is 0.67 atomic % with respect to the sum of Cu and inorganic elements derived from the inorganic layer, and the above-mentioned condition is satisfied for the first time, resulting in a copper layer near the inorganic layer. That is, the element concentration of O with respect to the sum of Cu, O, and inorganic elements derived from the inorganic layer at a moving distance in one direction in the thickness direction from the organic resin substrate of 33.1 μm is the element concentration of O of the copper layer near the inorganic layer in Comparative Example 1, which is 1.29 atomic %.

[0123] Therefore, from Table 1, it can be seen that even when an inorganic layer is provided, Examples 1 to 3, in which the elemental concentration of O in the copper layer 4 near the inorganic layer 3 is 1.4 atomic % or more and 15 atomic % or less relative to the sum of Cu, O, and the inorganic elements derived from the inorganic layer 3, can have a lower resistivity than Comparative Example 1, in which the elemental concentration of O in the copper layer 4 near the inorganic layer 3 is less than 1.4 atomic %, relative to the sum of Cu, O, and the inorganic elements derived from the inorganic layer 3, and Comparative Example 2, in which the elemental concentration of O in the copper layer 4 near the inorganic layer 3 is more than 15 atomic %, relative to the sum of Cu, O, and the inorganic elements derived from the inorganic layer 3.

[0124] In Examples 1 to 3, the resistivity was 2.300×10 -8 Specifically, it is clear that the material can be used as a conductor layer for patterning electrodes in various devices such as flat panel displays and touch panels, and is therefore practical enough to achieve a practical level of resistivity.

[0125] [Table 1] [Explanation of symbols]

[0126] 1 Conductive film 2 Organic resin base material 3 Inorganic layer 4 Copper Layers

Claims

1. An organic resin substrate; an inorganic layer disposed on one side in a thickness direction of the organic resin substrate; a copper layer disposed directly on one surface of the inorganic layer in a thickness direction; A conductive film, wherein the elemental concentration of O in the copper layer near the inorganic layer is 1.4 atomic % or more and 15 atomic % or less with respect to the total of Cu, O, and inorganic elements derived from the inorganic layer, as measured by energy dispersive X-ray analysis (EDX).

2. The conductive film according to claim 1 , wherein the copper layer has a thickness of 50 nm or more.

3. The conductive film according to claim 1 , wherein the copper layer has a thickness of 300 nm or less.

4. The conductive film according to any one of claims 1 to 3, wherein the inorganic layer has a thickness of 2 nm or more and 15 nm or less.

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