Conductive film

Abstract

A conductive film (1) is provided with: an organic resin substrate (2); an inorganic layer (3) disposed on one side of the organic resin substrate (2) in the thickness direction; and a copper layer (4) disposed directly on one surface of the inorganic layer (3) in the thickness direction, the copper layer (4) having a boundary vicinity region (4A) including a boundary between the copper layer (4) and the inorganic layer (3), and a boundary separation region (4B) disposed on one surface of the boundary vicinity region (4A) in the thickness direction, the boundary separation region (4B) having a thickness direction in which the copper layer (4) is separated from the inorganic layer (3) by a transmission electron microscope. A boundary vicinity region (4A) and a boundary separation region (4B) in a cross-section of the copper layer (4) have a difference in contrast.

Description

Technical Field

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

[0002] Conventionally, there is known a conductive film including a substrate and a metal layer in this order. Such a conductive film is used as a conductor layer for patterning electrodes in various devices such as flat panel displays and touch panels.

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

[0004] On the other hand, in the manufacture of the above-mentioned conductive film, degassing from the substrate sometimes occurs. Due to such degassing, metal oxides are formed on the other side of the metal layer in the thickness direction. This may cause the adhesion between the substrate and the metal layer to decrease.

[0005] In view of 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 contacting the metal layer, thereby eliminating the above-mentioned inconvenience.

[0006] As such a conductive film, a conductive film including a resin film, an inorganic layer, and a copper layer in this order has been proposed (for example, refer to Patent Document 1).

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: Japanese Patent Application Publication No. 2017-100368 Summary of the invention

[0010] Problems to be solved by the invention

[0011] On the other hand, when the barrier layer is provided, there is a problem in that the resistivity of the metal layer (copper layer) increases.

[0012] The present invention provides a conductive film which can suppress outgassing from an organic resin substrate from coming into contact with a copper layer and has excellent resistivity.

[0013] Solutions for solving problems

[0014] The present invention [1] includes a conductive film comprising: an organic resin substrate; an inorganic layer disposed on one side in the thickness direction of the organic resin substrate; and a copper layer disposed directly on one side in the thickness direction of the inorganic layer, the copper layer having a near-boundary region and a boundary separation region, the near-boundary region including a boundary with the inorganic layer, the boundary separation region disposed on one side in the thickness direction of the near-boundary region, and a difference in contrast between the near-boundary region and the boundary separation region at a cross section of the copper layer under observation with a transmission electron microscope.

[0015] The present invention [2] includes the conductive film described in the above [1], wherein the copper layer has a thickness of 50 nm or more.

[0016] The present invention [3] includes the conductive film described in [1] or [2] above, wherein the copper layer has a thickness of 300 nm or less.

[0017] The present invention [4] includes the conductive film according to any one of [1] to [3] above, wherein the thickness of the inorganic layer is 2 nm or more and 15 nm or less.

[0018] Effects of the Invention

[0019] The conductive film of the present invention includes an inorganic layer. Therefore, when the conductive film is manufactured, it is possible to suppress outgassing from the organic resin substrate from coming into contact with the copper layer. As a result, it is possible to suppress a decrease in adhesion between the organic resin substrate and the copper layer.

[0020] Furthermore, the conductive film of the present invention has a near-boundary region and a boundary separation region in the copper layer, wherein the near-boundary region includes the boundary between the copper layer and the inorganic layer, and the boundary separation region is arranged on one side in the thickness direction of the near-boundary region. Under transmission electron microscope (TEM) observation, there is a difference in contrast between the near-boundary region and the boundary separation region at the cross section of the copper layer, thereby being able to reduce the resistivity of the copper layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 One embodiment of the conductive film of the present invention is shown.

[0022] Figure 2A to Figure 2C One embodiment of a method for producing a conductive film is shown. Figure 2A This shows the first step of preparing an organic resin substrate. Figure 2B This shows the second step of disposing an inorganic layer on one surface in the thickness direction of the organic resin substrate. Figure 2C This shows the third step of disposing a copper layer on one surface in the thickness direction of the inorganic layer.

[0023] Figure 3 This is a TEM image of a cross section of the copper layer of Example 1.

[0024] Figure 4 This is a TEM image of a cross section of the copper layer of Example 2.

[0025] Figure 5 This is a TEM image of a cross section of the copper layer of Example 3.

[0026] Figure 6 This is a TEM image of a cross section of the copper layer of Comparative Example 1. DETAILED DESCRIPTION

[0027] 1. Conductive film

[0028] Reference Figure 1 , one embodiment of the conductive film of the present invention is described.

[0029] exist Figure 1 In the figure, the up-down direction of the paper is the up-down direction (thickness direction). In addition, the upper side of the paper is the upper side (one side in the thickness direction). In addition, the lower side of the paper is the lower side (the other side in the thickness direction). In addition, the left-right direction and the depth direction of the paper are the surface directions orthogonal to the up-down direction. Specifically, the direction arrows of each figure are used as a reference.

[0030] The conductive film 1 has a film shape (including a sheet shape) having 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.

[0031] like Figure 1 As shown, the conductive film 1 comprises: an organic resin substrate 2; an inorganic layer 3, which is disposed on one side in the thickness direction of the organic resin substrate 2; and a copper layer 4, which is directly disposed on one side in the thickness direction of the inorganic layer 3. Specifically, the conductive film 1 comprises: an organic resin substrate 2; an inorganic layer 3, which is directly disposed on the upper surface (one side in the thickness direction) of the organic resin substrate 2; and a copper layer 4, which is directly disposed on the upper surface (one side in the thickness direction) of the inorganic layer 3.

[0032] The thickness of the conductive film 1 is, for example, 1 μm or more, preferably 5 μm or more, and, for example, 300 μm or less, preferably 200 μm or less.

[0033] <Organic resin base material>

[0034] The organic resin substrate 2 has a film shape. The organic resin substrate 2 has flexibility. The organic resin substrate 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 substrate 2 is the lowermost layer of the conductive film 1.

[0035] As the organic resin substrate 2, for example, a polymer film can be mentioned.

[0036] Examples of the material of the polymer film include polyester resins, (meth)acrylic resins, olefin resins, polycarbonate resins, polyethersulfone resins, polyarylate resins, melamine resins, polyamide resins, polyimide resins, cellulose resins, and polystyrene resins, and preferably polyester resins are used.

[0037] As a polyester resin, polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate are mentioned, for example, and polyethylene terephthalate is preferably mentioned.

[0038] As a (meth)acrylic resin, polymethyl methacrylate is mentioned, for example.

[0039] Examples of the olefin resin include polyethylene, polypropylene, and cycloolefin polymers.

[0040] As a cellulose resin, cellulose triacetate is mentioned, for example.

[0041] The thickness of the organic resin substrate 2 is, for example, 1 μm or more, preferably 5 μm or more, more preferably 10 μm or more, further 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.

[0042] The thickness of the organic resin substrate 2 can be measured using a micrometer (“DG-205” manufactured by PEACOCK).

[0043] Furthermore, the organic resin substrate 2 preferably has transparency. Specifically, the total light transmittance (JISK 7375-2008) of the organic resin substrate 2 is, for example, 80% or more, or preferably 85% or more.

[0044] <Inorganic layer>

[0045] 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 later.

[0046] The inorganic layer 3 has a film shape and is disposed on the entire upper surface of the organic resin substrate 2 so as to be in contact with the upper surface of the organic resin substrate 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.

[0047] The inorganic layer 3 will be described in detail later, but is formed by a sputtering method and is therefore a sputtered layer.

[0048] The material of the inorganic layer 3 is not particularly limited as long as it is an inorganic substance other than pure metallic copper. Specifically, preferred materials for the inorganic layer 3 include metals (excluding pure metallic copper) and metal oxides (excluding copper oxide).

[0049] Examples of the metal include Ni, In, Sn, Zn, Ga, Sb, Ti, Si, Zr, Mg, Al, Au, Ag, Pd, and W, alloys of these metals, and alloys of these metals and copper.

[0050] Examples of the metal oxide include oxides of the above-mentioned metals. Preferred examples of the metal oxide include oxides containing indium. Examples of the indium-containing oxide include indium tin composite oxide (ITO).

[0051] Furthermore, the metal oxide may be either crystalline or amorphous.

[0052] As a material of the inorganic layer 3, metal oxides are preferably used.

[0053] The material of the inorganic layer 3 may be used alone or in combination of two or more.

[0054] The thickness of the inorganic layer 3 is, for example, 2 nm or more from the viewpoint of gas barrier properties, and is, for example, 15 nm or less, preferably 10 nm or less, and more preferably 7 nm or less from the viewpoint of processability.

[0055] In addition, the thickness of the inorganic layer 3 can be measured by observing the cross section of the conductive film 1 using a transmission electron microscope, for example.

[0056] <Copper layer>

[0057] The copper layer 4 is a conductor layer and is formed into a desired pattern as required.

[0058] The copper layer 4 has a film shape and is disposed on 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.

[0059] The copper layer 4 includes a boundary vicinity region 4A including a boundary between the copper layer 4 and the inorganic layer 3 , and a boundary separation region 4B disposed on one surface of the boundary vicinity region 4A in the thickness direction.

[0060] The copper layer 4 will be described in detail later, but is formed by sputtering and is therefore a sputtered layer.

[0061] Examples of the material of the copper layer 4 include copper (copper in the form of pure metal) and copper alloys.

[0062] The metal constituting the copper alloy is not particularly limited, and examples thereof include silver, tin, chromium, and zirconium.

[0063] As a material of the copper layer 4, copper (pure metal copper) is preferably used from the viewpoint of electrical conductivity. That is, the copper layer 4 is preferably composed of copper (pure metal copper).

[0064] 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, and usually 1.000×10 －8 Ω·m or more.

[0065] In addition, the resistivity can be calculated by multiplying the surface resistance value measured by the four-probe method according to JIS K7194 by the thickness of the copper layer 4 .

[0066] 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.

[0067] The lower limit of the surface resistance value of the copper layer 4 is not particularly limited. For example, the surface resistance value of the copper layer 4 is usually more than 0Ω / □.

[0068] In addition, the surface resistance value can be measured by a four-probe method in accordance with JIS K7194.

[0069] The thickness of the copper layer 4 is, for example, 50 nm or more, preferably 70 nm or more, more preferably 90 nm or more, and further preferably 100 nm or more from the viewpoint of resistance value, and is, for example, 300 nm or less, preferably 250 nm or less, more preferably 200 nm or less, further preferably 150 nm or less, and particularly preferably 120 nm or less from the viewpoint of productivity.

[0070] The thickness of the copper layer 4 is the sum of a boundary vicinity region 4A described later and a boundary separation region 4B described later, and can be measured by observing a cross section of the copper layer 4 using a transmission electron microscope, for example.

[0071] [Area near the border]

[0072] The near-boundary region 4A is a region of the copper layer 4 that includes the boundary between the copper layer 4 and the inorganic layer 3 and is near the boundary.

[0073] It was visually confirmed that the boundary vicinity region 4A in the cross section of the copper layer 4 was relatively white under observation with a transmission electron microscope.

[0074] The average thickness of the region 4A near the boundary is, for example, greater than or equal to 1 nm, preferably greater than or equal to 5 nm, more preferably greater than or equal to 10 nm, and is, for example, less than or equal to 50 nm, preferably less than or equal to 30 nm, more preferably less than or equal to 20 nm.

[0075] It should be noted that the average thickness of the region 4A near the boundary can be measured, for example, by using a transmission electron microscope to observe the cross section of the copper layer 4. Specifically, the average thickness of the region 4A near the boundary is a value obtained by measuring the thickness of the region 4A near the boundary every 1 nm in width in one field of view width [nm] of the transmission electron microscope, and dividing the total of the thicknesses by one field of view width [nm].

[0076] [Border separation area]

[0077] The boundary separation region 4B is a region of the copper layer 4 that is arranged in a manner continuous with the boundary vicinity region 4A in the thickness direction of the boundary vicinity region 4A and is separated from the boundary between the copper layer 4 and the inorganic layer 3. In other words, the boundary separation region 4B is arranged on the side opposite to the inorganic layer 3 of the boundary vicinity region 4A.

[0078] It was visually confirmed that the boundary separation region 4B in the cross section of the copper layer 4 was relatively black under observation with a transmission electron microscope.

[0079] The average thickness of the boundary separation region 4B is, for example, greater than or equal to 30 nm, preferably greater than or equal to 50 nm, more preferably greater than or equal to 70 nm, and is, for example, less than or equal to 250 nm, preferably less than or equal to 200 nm, more preferably less than or equal to 150 nm, and further preferably less than or equal to 100 nm.

[0080] It should be noted that the average thickness of the boundary separation region 4B can be measured, for example, by using a transmission electron microscope to observe the cross section of the copper layer 4. Specifically, the average thickness of the boundary separation region 4B is a value obtained by measuring the thickness of the boundary separation region 4B every 1 nm in width in one field of view width [nm] of the transmission electron microscope, and dividing the total of the thicknesses by one field of view width [nm].

[0081] Under transmission electron microscope observation, there is a difference in contrast between the boundary vicinity region 4A and the boundary separation region 4B in the cross section of the copper layer 4. In other words, when there is a difference in contrast, the boundary vicinity region 4A and the boundary separation region 4B appear.

[0082] The differences in contrast can be listed as follows: for example, a boundary is visually confirmed between the region 4A near the boundary and the boundary separation region 4B, that is, the regions are visually confirmed to be stacked in layers in the thickness direction; in addition, for example, a stripe pattern is visually confirmed in a direction intersecting the surface direction of the region 4A near the boundary and the boundary separation region 4B, and the spacing of the stripes is different in each region; further, for example, it is visually confirmed that the size of the grains (grain size) observed in the region 4A near the boundary and the boundary separation region 4B is different in each region.

[0083] If there is a difference in contrast between the boundary vicinity region 4A and the boundary separation region 4B in the cross section of the copper layer 4 under transmission electron microscope observation, the copper layer 4 has an excellent resistivity.

[0084] 2. Method for producing conductive film

[0085] Reference Figure 2A to Figure 2C , a method for manufacturing the conductive film 1 is described.

[0086] The method for producing the conductive film 1 comprises: a first step of preparing an organic resin substrate 2; a second step of disposing an inorganic layer 3 on one side in the thickness direction of the organic resin substrate 2 by sputtering; and a third step of disposing a copper layer 4 on one side in the thickness direction of the inorganic layer 3 by sputtering. In this method, the layers are sequentially disposed, for example, in a roll-to-roll manner. 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.

[0087] In the method for producing the conductive film 1 , in the second step and the third step, the sputtering method is performed while supplying the sputtering gas.

[0088] In the method for producing the conductive film 1, in the second step, for example, an inert gas (described later) is supplied as a sputtering gas. Preferably, in the second step, an inert gas (described later) and oxygen gas are supplied as a sputtering gas.

[0089] In the method for manufacturing the conductive film 1, in the third step, a target material, sputtering conditions, etc. are appropriately set to perform sputtering a plurality of times in order to form the desired copper layer 4. In the third step, the number of sputterings is, for example, two or more times, preferably four or more times, and, for example, twenty or less times, preferably ten or less times.

[0090] In the method for manufacturing the conductive film 1, in the third step, for example, an inert gas (described later) is supplied as a sputtering gas. Preferably, in the first sputtering of the third step, an inert gas (described later) and oxygen are supplied as a sputtering gas, and in the second and subsequent sputterings of the third step, only an inert gas (described later) is supplied as a sputtering gas.

[0091] That is, in the method for manufacturing the conductive film 1, for example, in the second step, the inert gas and oxygen are supplied together by sputtering, and the inorganic layer 3 is arranged on one side in the thickness direction of the organic resin substrate 2, and in the third step, only the inert gas is supplied by sputtering, and the copper layer 4 is arranged on one side in the thickness direction of the inorganic layer 3. In addition, for example, in the second step, only the inert gas is supplied by sputtering, and the inorganic layer 3 is arranged on one side in the thickness direction of the organic resin substrate 2, and in the third step, inert gas and oxygen are supplied together in the first sputtering by sputtering, and only the inert gas is supplied in the second and subsequent sputterings, and the copper layer 4 is arranged on one side in the thickness direction of the inorganic layer 3. Furthermore, for example, in the second step, an inert gas and oxygen are supplied together by sputtering, and the inorganic layer 3 is arranged on one side in the thickness direction of the organic resin substrate 2. In the third step, an inert gas and oxygen are supplied together by sputtering in the first sputtering, and only an inert gas is supplied in the second and subsequent sputterings, and the copper layer 4 is arranged on one side in the thickness direction of the inorganic layer 3. Preferably, in the method for manufacturing the conductive film 1, in the second step, an inert gas and oxygen are supplied together by sputtering, and the inorganic layer 3 is arranged on one side in the thickness direction of the organic resin substrate 2. In the third step, an inert gas and oxygen are supplied together by sputtering in the first sputtering, and only an inert gas is supplied in the second and subsequent sputterings, and the copper layer 4 is arranged on one side in the thickness direction of the inorganic layer 3.

[0092] In the following description, a method for producing the conductive film 1 is described in detail.

[0093] [First process]

[0094] In the first step, Figure 2A As shown, an organic resin substrate 2 is prepared.

[0095] [Second step]

[0096] In the second step, Figure 2B As shown, the inorganic layer 3 is disposed on one surface in the thickness direction of the organic resin substrate 2 by sputtering.

[0097] In order to arrange the inorganic layer 3 on one surface in the thickness direction of the organic resin substrate 2 by the sputtering method, first, the one surface in the thickness direction of the organic resin substrate 2 is subjected to a surface treatment as required.

[0098] Examples of the surface treatment include corona treatment, plasma treatment, flame treatment, ozone treatment, primer treatment, glow treatment, and saponification treatment.

[0099] Next, in the sputtering method, a target (material of the inorganic layer 3) and an organic resin substrate 2 are placed opposite each other in a vacuum chamber of a sputtering film forming device. Then, a sputtering gas is supplied and a voltage is applied from a power supply, thereby accelerating gas ions and irradiating them to the target, and the target material is ejected from the target surface. Then, the target material is deposited on the surface (one side in the thickness direction) of the organic resin substrate 2 to form an inorganic layer 3.

[0100] In addition, as the sputtering gas, for example, only an inert gas (for example, argon gas) or an inert gas and oxygen gas may be supplied. Preferably, an inert gas and oxygen gas are supplied as the sputtering gas.

[0101] When an inert gas and oxygen are supplied together, the flow rate of oxygen is, for example, greater than 5 sccm, preferably greater than 10 sccm, more preferably greater than 20 sccm, further preferably greater than 30 sccm, particularly preferably greater than 40 sccm, and, for example, less than 200 sccm, preferably less than 100 sccm.

[0102] When the inert gas and oxygen are supplied together, the flow rate ratio of the inert gas to the oxygen is, for example, 3.5 or more, preferably 10 or more, and, for example, 200 or less, preferably 100 or less, and more preferably 50 or less.

[0103] The gas 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.

[0104] The power source may be, for example, a DC (Direct Current) power source, an AC (Alternating Current) power source, an MF (Middle Frequency) power source, or an RF (Radio Frequency) power source, or a combination of these power sources.

[0105] The discharge power is, for example, 1.0 kW or more, preferably 5.0 kW or more, and, for example, 20 kW or less.

[0106] Thus, the inorganic layer 3 is disposed on one surface in the thickness direction of the organic resin substrate 2 .

[0107] [Third step]

[0108] In the third step, Figure 2C As shown, the copper layer 4 is disposed on one surface in the thickness direction of the inorganic layer 3 by sputtering.

[0109] In the sputtering method, a target (material of the copper layer 4) and an inorganic layer 3 are arranged opposite to each other in a vacuum chamber of a sputtering film forming device. Then, a sputtering gas is supplied and a voltage is applied from a power supply, thereby accelerating gas ions and irradiating them to the target, and the target material is ejected from the target surface. Then, the target material is deposited on the surface (one side in the thickness direction) of the inorganic layer 3 to form a copper layer 4.

[0110] In the third step, the target material, sputtering conditions, etc. are appropriately set to perform multiple sputtering in order to form the desired copper layer 4. In the third step, the number of sputtering is, for example, two or more times, preferably four or more times, and, for example, twenty or less times, preferably ten or less times.

[0111] In addition, as the sputtering gas, for example, only an inert gas (such as argon) is supplied, or an inert gas and oxygen are supplied. More specifically, as the sputtering gas, for example, only an inert gas is supplied in all sputtering, or, in the first sputtering, an inert gas and oxygen are supplied, and in the second and subsequent sputtering, only an inert gas is supplied. Preferably, as the sputtering gas, in the first sputtering, an inert gas and oxygen are supplied, and in the second and subsequent sputtering, only an inert gas is supplied.

[0112] When an inert gas and oxygen are supplied together, the flow rate of oxygen is less than the flow rate of oxygen in the above-mentioned second process, 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.

[0113] When an inert gas and oxygen are supplied together, the flow rate ratio of the inert gas to the oxygen is, for example, 40 or more, and for example, 500 or less, preferably 200 or less, more preferably 100 or less, and further preferably 50 or less.

[0114] The gas 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.

[0115] The power source may be, for example, any of a DC power source, an AC power source, an MF power source, and an RF power source, or may be a combination of these power sources.

[0116] The discharge power is, for example, 5.0 kW or more, preferably 10.0 kW or more, and, for example, 20 kW or less.

[0117] The film formation temperature (the temperature of the organic resin substrate 2 on which the inorganic layer 3 is provided) is, for example, 30° C. or higher, and for example, 60° C. or lower.

[0118] Thus, the copper layer 4 is formed on one surface in the thickness direction of the inorganic layer 3 .

[0119] The copper layer 4 thus formed has a region 4A near the boundary and a boundary separation region 4B, wherein the region 4A near the boundary includes the boundary between the copper layer 4 and the inorganic layer 3, and the boundary separation region 4B is arranged on one side in the thickness direction of the region 4A near the boundary, and under observation with a transmission electron microscope, there is a difference in contrast between the region 4A near the boundary and the boundary separation region 4B at the cross section of the copper layer 4. Specifically, the region 4A near the boundary is formed by the first sputtering, and the boundary separation region 4B is formed by sputtering from the second to the last time.

[0120] In the above manner, the conductive film 1 is manufactured.

[0121] <Effects>

[0122] The conductive film 1 includes the inorganic layer 3 . Therefore, when the conductive film 1 is produced, it is possible to suppress outgassing from the organic resin substrate 2 from coming into contact with the copper layer 4 .

[0123] Specifically, during the production of the conductive film 1, outgassing may occur from the organic resin substrate 2. Due to such outgassing, copper oxide is formed on the other surface in the thickness direction of the copper layer 4. This may reduce the adhesion between the organic resin substrate 2 and the copper layer 4.

[0124] On the other hand, the conductive film 1 includes the inorganic layer 3. This can prevent the above-mentioned outgassing from contacting the copper layer 4. In this way, the formation of copper oxide on the other surface in the thickness direction of the copper layer 4 can be suppressed, and as a result, the decrease in the adhesion between the organic resin substrate 2 (inorganic layer 3) and the copper layer 4 can be suppressed.

[0125] In addition, the copper layer 4 of the conductive film 1 has a region near the boundary 4A and a boundary separation region 4B, wherein the region near the boundary 4A includes the boundary between the copper layer 4 and the inorganic layer 3, and the boundary separation region 4B is arranged on one surface in the thickness direction of the region near the boundary 4A. Under transmission electron microscope observation, there is a difference in contrast between the region near the boundary 4A and the boundary separation region 4B in the cross section of the copper layer 4. Therefore, the resistivity of the copper layer 4 can be reduced.

[0126] <Modification>

[0127] In the modification, the same reference numerals are used for the same components and processes as those in one embodiment, and detailed description thereof is omitted. In addition, the modification can exert the same effects as those in the first embodiment except for special descriptions. Moreover, one embodiment and its modification can be appropriately combined.

[0128] 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 (for example, a hard coating layer) may be disposed between the organic resin substrate 2 and the inorganic layer 3. In this case, the conductive film 1 includes the organic resin substrate 2, the hard coating layer, the inorganic layer 3, and the copper layer 4 in this order in the thickness direction.

[0129] [Example]

[0130] Embodiment and comparative example are shown below, and the present invention is further specifically described.It should be noted that the present invention is not limited to any embodiment and comparative example.In addition, the specific numerical values ​​such as the mixing ratio (containing ratio), physical property value, parameter used in the following description can be replaced by the upper limit value (defined as "below", "less than") or the lower limit value (defined as "above", "exceeding") of the mixing ratio (containing ratio), physical property value, parameter, etc. corresponding to these numerical values ​​recorded in the above-mentioned "specific embodiments".

[0131] <Manufacturing of conductive film>

[0132] Example 1

[0133] The conductive film was produced according to the following steps.

[0134] [First process]

[0135] As an organic resin substrate, polyethylene terephthalate (125U48, manufactured by TORAY CORPORATION, thickness 125 μm) was prepared.

[0136] [Second step]

[0137] An inorganic layer (ITO layer) (thickness 5 nm) was disposed on one surface in the thickness direction of the organic resin substrate by sputtering under the following conditions.

[0138] {condition}

[0139] Device: Roll-to-roll sputtering film forming device (winding type DC magnetron sputtering device).

[0140] Material of the inorganic layer: ITO.

[0141] Gas: Argon and oxygen (oxygen flow rate 20 sccm).

[0142] Flow rate ratio of the inert gas flow rate to the oxygen flow rate: 35.

[0143] Discharge power: 7.2kW.

[0144] Air pressure in the film forming chamber: 0.4Pa.

[0145] Travel speed: 8.0m / min.

[0146] [Third step]

[0147] A copper layer (104 nm) was arranged on one surface in the thickness direction of the inorganic layer by sputtering under the following conditions. It should be noted that sputtering was performed eight times until the desired thickness was reached.

[0148] {condition}

[0149] Device: Roll-to-roll sputtering film forming device (winding type DC magnetron sputtering device).

[0150] Gas: Argon.

[0151] Discharge power: 14.7kW.

[0152] Air pressure in the film forming chamber: 0.4Pa.

[0153] Film forming temperature: 40℃.

[0154] Travel speed: 8.0m / min.

[0155] It should be noted that after the sputtering in the second step, the first sputtering in the third step is performed continuously.

[0156] Example 2

[0157] A conductive film was produced according to the same procedure as in Example 1. However, based on the description in Table 1, the flow rate of oxygen in the second step was changed.

[0158] Example 3

[0159] The first step and the second step were performed in the same manner as in Example 2, and the third step was performed in the following manner to produce a conductive film.

[0160] [Third step]

[0161] A copper layer (thickness 12 nm) was arranged on one surface in the thickness direction of the inorganic layer by sputtering under the following conditions. It should be noted that sputtering was performed only once.

[0162] {condition}

[0163] Device: Roll-to-roll sputtering film forming device (winding type DC magnetron sputtering device).

[0164] Gas: Argon and oxygen (oxygen flow rate 15 sccm).

[0165] Flow rate ratio of the inert gas flow rate to the oxygen flow rate: 47.

[0166] Discharge power: 14.7kW.

[0167] Air pressure in the film forming chamber: 0.4Pa.

[0168] Film forming temperature: 40℃.

[0169] Travel speed: 8.0m / min.

[0170] It should be noted that after the sputtering in the second step, the first sputtering in the third step is performed continuously.

[0171] Next, a copper layer (thickness 92 nm) was further deposited by sputtering under the following conditions. It should be noted that sputtering was performed seven times until the desired thickness was reached.

[0172] {condition}

[0173] Device: Roll-to-roll sputtering film forming device (winding type DC magnetron sputtering device).

[0174] Gas: Argon.

[0175] Discharge power: 14.7kW.

[0176] Air pressure in the film forming chamber: 0.4Pa.

[0177] Film forming temperature: 40℃.

[0178] Travel speed: 8.0m / min.

[0179] Comparative Example 1

[0180] A conductive film was produced according to the same procedure as in Example 1. However, the flow rate of oxygen gas was changed according to the description in Table 1. Specifically, in the second step, oxygen gas was not supplied.

[0181] <Evaluation>

[0182] (Surface resistance)

[0183] The surface resistance value of the copper layer of each Example and Comparative Example 1 was measured by a four-probe method in accordance with JIS K7194. The results are shown in Table 1.

[0184] (Resistivity)

[0185] The resistivity of the copper layer in each Example and Comparative Example 1 was calculated by multiplying the surface resistance value by the thickness of the copper layer. The results are shown in Table 1.

[0186] (Presence or absence of difference in contrast)

[0187] The TEM images of the cross sections of the copper layers of each example and comparative example 1 are shown in FIG. Figure 3 to Figure 6Table 1 shows the presence or absence of a contrast difference between the boundary vicinity region and the boundary separation region of the copper layer in each Example and Comparative Example 1.

[0188] <Investigation>

[0189] It is understood that since Examples 1 to 3 and Comparative Example 1 include an inorganic layer, outgassing from the organic resin substrate can be suppressed from coming into contact with the copper layer.

[0190] In addition, Figure 3 In the embodiment 1, the copper layer has a part of the boundary line between the boundary vicinity region and the boundary separation region, that is, it is visually confirmed that each region is stacked in a layered manner in the thickness direction. Thus, the copper layer has a boundary vicinity region and a boundary separation region, and there is a difference in contrast between the boundary vicinity region and the boundary separation region.

[0191] Then, in Figure 4 In the embodiment 2, the copper layer has a part of the boundary line between the region near the boundary and the region separated by the boundary, that is, it is visually confirmed that each region is stacked in a layered manner in the thickness direction. Thus, the copper layer has a region near the boundary and a region separated by the boundary, and there is a difference in contrast between the region near the boundary and the region separated by the boundary.

[0192] Moreover, in Figure 5 In the embodiment 3, the copper layer has a stripe pattern in the direction intersecting the surface direction in the region near the boundary and the region separated by the boundary, and the interval of the stripes is different in each region. In addition, it is also visually confirmed that the size of the crystal grains observed in the region near the boundary and the region separated by the boundary is different in each region. Therefore, the copper layer has a region near the boundary and a region separated by the boundary, and there is a difference in contrast between the region near the boundary and the region separated by the boundary.

[0193] On the other hand, Figure 6 In the copper layer of Comparative Example 1, no boundary is visually confirmed between the region near the boundary and the boundary separation region, no stripe pattern exists in the direction intersecting the surface direction in the region near the boundary and the boundary separation region, and the size (grain size) of the crystal grains observed in the region near the boundary and the boundary separation region is not different in each region. Therefore, there is no difference in contrast between the region near the boundary and the boundary separation region of the copper layer.

[0194] According to Table 1, even in the case of having an inorganic layer, Examples 1 to 3 can reduce the resistivity compared with Comparative Example 1. In Examples 1 to 3, there are areas near the boundary and areas separated by the boundary, and there is a difference in contrast between the areas near the boundary and the areas separated by the boundary. In Comparative Example 1, there is no difference in contrast between the areas near the boundary and the areas separated by the boundary.

[0195] Examples 1 to 3 can make the resistivity between 2.300×10 －8 Specifically, it is known that the practicability of achieving a resistivity at a practical level can be ensured, especially as a conductor layer for patterning electrodes in various devices such as flat panel displays and touch panels.

[0196] [Table 1]

[0197]

[0198] It should be noted that the above invention is provided as an exemplary embodiment of the present invention, but this is merely an example and should not be interpreted restrictively. Modifications of the present invention that are obvious to those skilled in the art are included in the claims.

[0199] Industrial Applicability

[0200] The conductive film of the present invention is used in various devices such as flat panel displays and touch panels.

[0201] Description of Reference Numerals

[0202] 1: conductive film; 2: organic resin substrate; 3: inorganic layer; 4: copper layer; 4A: region near the boundary; 4B: boundary separation region.

Claims

1. A conductive film, wherein: The conductive film comprises: Organic resin substrate; an inorganic layer disposed on one side in the thickness direction of the organic resin substrate; and The copper layer is directly disposed on one side of the inorganic layer in the thickness direction. The copper layer has a region near the boundary and a region separated from the boundary, The region near the boundary includes a boundary between the copper layer and the inorganic layer. The boundary separation region is arranged on one surface in the thickness direction of the region near the boundary, Under observation with a transmission electron microscope, there is a difference in contrast between the region near the boundary and the boundary separation region in the cross section of the copper layer.

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 less than 300 nm.

4. The conductive film according to any one of claims 1 to 3, wherein The thickness of the inorganic layer is greater than or equal to 2 nm and less than or equal to 15 nm.

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