CN211879035U

CN211879035U - Conducting film

Info

Publication number: CN211879035U
Application number: CN202020542804.5U
Authority: CN
Inventors: 冯俊敏; 张万财; 吴婷婷
Original assignee: Shenzhen Haihan New Energy Technology Co ltd
Current assignee: Xiamen Hithium Energy Storage Technology Co Ltd
Priority date: 2020-04-13
Filing date: 2020-04-13
Publication date: 2020-11-06
Anticipated expiration: 2030-04-13

Abstract

The application provides a conducting film, belongs to conducting film technical field. The conductive film comprises an insulating layer, and a bonding layer, a metal layer and a protective layer which are sequentially arranged on the surface of the insulating layer; the bonding layer is one of a Ti metal layer, a W metal layer, a Cr metal layer, a Cu metal layer and an alloy layer thereof. The protective layer is a conductive non-metal protective layer or an inert metal protective layer; the metal of the inert metal protective layer is Cr or Cr alloy; the non-metal protective layer is a glucose complex layer or a potassium dichromate layer. The bonding force between the metal layer and the insulating layer can be stronger due to the arrangement of the bonding layer and the protective layer, the metal layer of the conductive film is prevented from being stripped in the using process, the oxidation and even falling of the metal layer can be effectively improved, and the service life of the conductive film is prolonged.

Description

Conducting film

Technical Field

The application relates to the technical field of conductive films, in particular to a conductive film.

Background

In the prior art, a composite conductive film includes an insulating layer (polymer base layer) and a first conductive layer and a second conductive layer respectively disposed on two surfaces of the insulating layer. The conductive film is oxidized after long-term use, and the conductive layer is peeled off.

SUMMERY OF THE UTILITY MODEL

An object of this application is to provide a conductive film, can make the cohesion between metal level and the insulating layer stronger, avoid the conductive film to peel off at the in-process metal level of using, and can effectively improve the oxidation of metal level and drop even, prolong the life of conductive film.

In a first aspect, an embodiment of the present application provides a conductive film, including an insulating layer, and a bonding layer, a metal layer, and a protective layer sequentially formed on a surface of the insulating layer; the bonding layer is one of a Ti metal layer, a W metal layer, a Cr metal layer, a Cu metal layer and an alloy layer thereof. The protective layer is a conductive non-metal protective layer or an inert metal protective layer; the metal of the inert metal protective layer is Cr or Cr alloy; the non-metal protective layer is a glucose complex layer or a potassium dichromate layer.

In the conductive film, the bonding force between the metal layer and the insulating layer is stronger due to the arrangement and selection of the bonding layer and the protective layer, so that the metal layer is prevented from being stripped in the use process of the conductive film, the oxidation and even falling of the metal layer can be effectively improved, and the service life of the conductive film is prolonged.

In one possible embodiment, the thickness of the bonding layer is 2-40 nm. The bonding effect can be made better so as to further improve the bonding force between the metal layer and the insulating layer.

In one possible embodiment, the thickness of the protective layer is 0.1 to 100 nm. The protective effect of the protective layer can be better, and the oxidation of the metal layer is further avoided.

In one possible embodiment, the metal layer has a thickness of 50 to 3000 nm. The conductive effect of the conductive film is better.

In one possible embodiment, the metal layer is a copper layer. The conductive effect is good and the cost is low.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments are briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained from the drawings without inventive efforts and also belong to the protection scope of the present application.

Fig. 1 is a schematic structural diagram of a conductive film provided in an embodiment of the present application;

FIG. 2 is a scanning force microscope image of a conductive film;

FIG. 3 is a scanning electron micrograph of a conductive film;

FIG. 4 is a dark field diagram of a conductive film;

FIG. 5 is a bright field diagram of a conductive film;

fig. 6 is a photograph of a finished conductive film.

Icon: 110-an insulating layer; 120-a tie layer; 130-metal process layer; 140-a metal transition layer; 150-a metal functional layer; 160-protective layer.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application.

The inventors have found that in the prior art, the same process is typically used to deposit a metallic conductive layer on an insulating layer. If a thicker metal conductive layer is desired, it is typically obtained by single or multiple depositions using the same process. For example: if the metal conducting layer is formed on the surface of the insulating layer in an evaporation coating mode, the evaporation coating is a thermal deposition mode, the metal conducting layer can be quickly accumulated to a certain thickness, the efficiency is high, and the conductivity is good. However, the metal conductive layer obtained by the evaporation plating method is not uniform, has poor toughness and low strength, and causes a certain degree of deformation of the film. For example: the alkaline electroplating method is an electrochemical deposition process, can quickly accumulate a metal conductive layer to a certain thickness, has high efficiency and good conductivity, but the conductive layer obtained by the alkaline electroplating method has poor compactness.

If a metal conducting layer is formed on the surface of the insulating layer in a magnetron sputtering mode, the magnetron sputtering mode is a cold deposition mode, particularly large heat cannot be generated in the deposition process, and the formed metal conducting layer is of a sheet structure, so that the dispersibility is good, and the compactness is good. However, since the formation principle is that the conductive layer is formed under the action of a plasma magnetic field, new impurities (e.g., inert gas molecules) are introduced, which results in poor purity and poor conductivity of the metal conductive layer.

If the metal conductive layer is formed by electroplating with water, the substrate must have certain conductive properties, such as: and forming a metal conducting layer on the conductive polymer layer in a water electroplating mode so as to obtain the film with the conductive polymer layer in the middle and the metal conducting layers on the two surfaces. However, the conductive polymer has a poor conductivity compared to the metal, so that the conductive polymer substrate may have insufficient conductivity, resulting in poor formation of the metal conductive layer by water electroplating.

The inventor also finds that if the metal conductive layer is formed on the insulating layer by means of evaporation plating, and then the thickened metal conductive layer is further formed on the metal conductive layer by means of water electroplating. Because the metal conducting layer formed by the evaporation coating mode is uneven and poor in toughness, when the metal conducting layer is further thickened by the water electroplating mode, the thickened metal conducting layer has the defects of unevenness, poor toughness and poor compactness.

If a metal conducting layer is formed on the metal insulating layer in a magnetron sputtering mode, then a thickened metal conducting layer is further formed on the metal conducting layer in a water electroplating mode. Because the metal conducting layer formed by the magnetron sputtering method contains impurities, the purity is not high, the conductivity is poor and uneven, and then, in the water electroplating process, the conductivity of the base material is poor (the conductivity is uneven), so that the thickened metal conducting layer is uneven, and the thicker metal conducting layer cannot be obtained.

Therefore, in view of the above problems, the inventors provide a method for manufacturing a conductive film, and fig. 1 is a schematic structural diagram of the conductive film provided in the present application. The conductive film of fig. 1 is prepared by the following method, referring to fig. 1:

s10, selecting an insulating layer 110, that is, selecting a substrate, in this application, the material of the substrate may be one of OPP (O-phenylphenol), PET (Polyethylene terephthalate), PI (Polyimide), PS (Polystyrene ), PPS (Polyphenylene sulfide), CPP (Cast polypropylene film), PEN (Polyethylene naphthalate, Polyethylene terephthalate), PES (Polyethersulfone resin, Polyethylene sulforesin), PPS (polyphenylsulfone resin, Polyphenylene sulfide resin, Polyethylene sulfoether), PE (Polyethersulfone resin, Polyethylene sulfoether resin, or non-woven fabric.

Optionally, the thickness of the base layer is 1.2-12 μm, and further, the thickness of the base layer is 1.2-6 μm. For example: the thickness of the base layer is 1.2 μm, 1.5 μm, 2 μm, 4 μm, 8 μm or 12 μm.

S20, baking the insulating layer 110. The moisture content of the insulating layer 110 is reduced after baking, the moisture content of the insulating layer is less than 1000PPM, the adhesive property between the insulating layer 110 and the metal process layer 130 formed subsequently can be improved, the possibility that the metal process layer 130 is stripped can be reduced or even eliminated, and the bonding property of the whole conductive film is improved.

The water content of the film before and after baking is shown in tables 1 and 2 below by taking a PET film and a PP film as examples:

TABLE 1 Water content of PET film

TABLE 2 Water content of PP films

As can be seen from tables 1 and 2, the moisture content of the insulating layer 110 can be greatly reduced after baking, and the reduction degree of the moisture content is related to the film-feeding speed and the baking temperature.

In other embodiments, the moisture content of the insulating layer 110 may not be controlled.

S30, the adhesive layer 120 is formed on the surface of the insulating layer 110. The formation of the bonding layer 120 is matched with the control of the water content of the insulating layer 110 (the water content is less than 1000PPM), and has a certain synergistic effect, so that the bonding force between the metal process layer 130 formed subsequently and the insulating layer 110 can be effectively improved, and the stripping of the metal process layer 130 is further avoided, so that the bonding effect of the whole conductive film is better.

Optionally, the thickness of the adhesion layer 120 is 2-40 nm. For example: the thickness of the adhesive layer 120 is 2nm, 10nm, 15nm, 20nm, 30nm, or 40 nm. Here, the adhesive layer 120 may be formed on one surface of the insulating layer 110, or the adhesive layers 120 may be formed on both surfaces of the insulating layer 110, but the formation of the adhesive layer 120 may be controlled according to whether the target conductive film is one-sided conductive or two-sided conductive. In other embodiments, the adhesive layer 120 may not be provided.

The bonding layer 120 may be a metal material layer, and the metal material layer may be one or more of a Ti metal layer, a W metal layer, a Cr metal layer, a Ni metal layer, a Cu metal layer, and an alloy layer thereof. The bonding force between layers of the whole conductive film can be better under the condition of ensuring the compactness of the functional layer.

For example: the adhesion layer 120 may be a Ti metal layer, the adhesion layer 120 may be a W metal layer, the adhesion layer 120 may be a Ni metal layer, the adhesion layer 120 may be a Cu metal layer, the adhesion layer 120 may be a Ti alloy layer, the adhesion layer 120 may be a W alloy layer, the adhesion layer 120 may be a Ni alloy layer, the adhesion layer 120 may be a Cu alloy layer, and the like.

In the embodiment of the present application, the metal material layer may be one or more, for example: may be a pure metal layer; or an alloy layer; or forming a metal layer first and then another metal layer; it is also possible to form a metal layer first and then an alloy layer, etc. The embodiments of the present application are not limited.

Alternatively, the bonding layer 120 may be formed by evaporation coating or magnetron sputtering, and the embodiment of the present application is not limited thereto.

S40, forming the metal process layer 130 on the surface of the insulating layer 110 by evaporation, water electroplating or chemical plating, so as to quickly accumulate the metal process layer 130 to a certain thickness, with high efficiency, and the obtained metal process layer 130 has good conductivity, and can be used as a deposition substrate for forming the metal transition layer 140 subsequently.

If the adhesive layer 120 is not formed on the surface of the insulating layer 110, the metal process layer 130 is formed on the surface of the insulating layer 110 by evaporation plating, water electroplating or chemical plating. The metal process layer 130 may be formed on one surface, or the metal process layer 130 may be formed on both surfaces, which is not limited in the embodiment of the present application, and the formation of the metal process layer 130 may be controlled according to whether the target conductive film is one-sided conductive or two-sided conductive.

If the adhesion layer 120 is formed on the surface of the insulation layer 110, the metal process layer 130 is formed on the surface of the adhesion layer 120 by using an evaporation plating, water electroplating or electroless plating.

The metal process layer 130 may be a copper metal layer, a nickel metal layer, an aluminum metal layer, a titanium metal layer, an alloy layer thereof, and the like, which is not limited in this embodiment. If the metal process layer 130 is a copper metal layer, the production cost of the conductive film can be greatly reduced under the condition of ensuring better conductivity.

Optionally, the thickness of the metal process layer 130 is 2-100nm, and further, the thickness of the metal process layer 130 is 20-50 nm. For example: the thickness of the metal process layer 130 may be 2nm, 15nm, 20nm, 40nm, 50nm, 60nm, or 100 nm.

S50, forming the metal transition layer 140 on the surface of the metal process layer 130 away from the insulating layer 110 by magnetron sputtering, so that the metal transition layer 140 has better dispersibility, and the surface of the metal transition layer 140 is more uniform, has better compactness and no cracks, so as to form the metal functional layer 150 having better compactness and conductivity in the following process.

The metal transition layer 140 may be a copper metal layer, a nickel metal layer, an aluminum metal layer, a titanium metal layer, an alloy layer thereof, and the like, which is not limited in this embodiment. If the metal transition layer 140 is a copper metal layer, the production cost of the conductive film can be greatly reduced under the condition of ensuring better conductivity.

Optionally, the thickness of the metal transition layer 140 is 5-50nm, and further, the thickness of the metal transition layer 140 is 8-30 nm. For example: the thickness of the metal transition layer 140 may be 5nm, 8nm, 10nm, 15nm, 20nm, or 50 nm.

S60, forming a metal functional layer 150 on the surface of the metal transition layer 140 away from the metal process layer 130. Since the metal transition layer 140 has a good compactness, the metal functional layer 150 is formed on the basis of the metal transition layer 140, so that the obtained metal functional layer 150 has a higher compactness and better uniformity, and a conductive film with excellent performance is obtained.

The metal functional layer 150 may be a copper metal layer, a nickel metal layer, an aluminum metal layer, a titanium metal layer, an alloy layer thereof, and the like, which is not limited in this embodiment. If the metal functional layer 150 is a copper metal layer, the production cost of the conductive film can be greatly reduced under the condition of ensuring better conductivity.

Optionally, the thickness of the metal functional layer 150 is 30-2500nm, further, the thickness of the metal functional layer 150 is 300-1500nm, and further, the thickness of the metal functional layer 150 is 500-1000 nm. For example: the thickness of the metal functional layer 150 may be 30nm, 100nm, 500nm, 800nm, 1000nm, 2000nm, or 2500 nm.

Optionally, the metal functional layer 150 is formed on the surface of the metal transition layer 140 away from the metal process layer 130 by means of water electroplating. Because the metal process layer 130 has good conductivity and the metal transition layer 140 has good compactness, when the metal functional layer 150 is formed by the water electroplating method, the polymer base film formed with the metal process layer 130 and the metal transition layer 140 is used as the base material of the water electroplating, the base material not only has good conductivity, but also is the metal transition layer 140 with good compactness on the basis of the water electroplating, so that the formed metal functional layer 150 has good compactness, the metal functional layer 150 formed by the water electroplating method has higher purity, and the thicker metal functional layer 150 can be obtained, so that the metal functional layer 150 with better compactness and conductivity and thicker thickness can be obtained.

In another embodiment, the metal functional layer 150 may be formed on the surface of the metal transition layer 140 by evaporation plating or nano-spraying. Optionally, the metal process layer 130, the metal transition layer 140, and the metal functional layer 150 are all made of the same metal, or may be made of different metals. If the metal process layer 130, the metal transition layer 140 and the metal functional layer 150 are made of the same metal and are made by different processes, the metal functional layer 150 can have a good densification effect, a thick thickness and a good purity under the condition that the metal transition layer 140 is thin, so as to improve the performance of the conductive film.

S70, forming a protective layer 160 on the surface of the metal functional layer 150 away from the metal transition layer 140. The metal functional layer 150 can be protected, the metal functional layer 150 is prevented from being oxidized and even falling off, and the metal functional layer 150 is prevented from being damaged.

In the embodiment of the present application, the forming manner of the protection layer 160 is not limited. The protective layer 160 is a conductive non-metallic protective layer or an inert metal protective layer. Alternatively, the thickness of the protective layer 160 is 0.1 to 100nm, and further, the thickness of the protective layer 160 is 10 to 50 nm. For example: the thickness of the protective layer 160 is 0.1nm, 2nm, 10nm, 30nm, 50nm, 80nm, or 100 nm.

If the protective layer 160 is an inert metal protective layer, the metal of the inert metal protective layer is one of Cr, Ni alloy, and Cr alloy. For example: the protective layer 160 may be a Cr layer; the protective layer 160 may be a Ni layer; the protective layer 160 may be a Ni alloy layer; the protective layer 160 may be a Cr alloy layer. If the protective layer 160 is a non-metallic protective layer that is electrically conductive, the protective layer 160 may be a glucose complex layer; the protective layer 160 may also be a potassium dichromate layer.

The conductive film formed by the above-mentioned preparation method includes an insulating layer 110, and an adhesive layer 120 and a conductive layer sequentially disposed on a surface of the insulating layer 110, wherein the conductive layer includes the metal process layer 130, the metal transition layer 140, the metal functional layer 150, and the protective layer 160 sequentially disposed. The metal process layer 130 is attached to the adhesive layer 120. In the conductive film, the adhesive layer 120 may be present or not; the conductive layer may include one or more of a metal process layer 130, a metal transition layer 140, and a metal functional layer 150 in addition to the protective layer.

In the conductive film, the metal functional layer 150 mainly plays a role in conducting, and has the advantages of good compactness (the density is more than 60%), high purity, good conductivity and uniform thickness. And the bonding force between the middle layers of the conductive film is better, so that the peeling of the middle layer structure of the conductive film can be reduced or even eliminated.

Example 1

The preparation method of the conductive film comprises the following steps:

forming copper process layers with the thickness of about 21nm on two surfaces of a PP insulating layer with the thickness of about 2 mu m and the water content of about 2152PPM in an evaporation coating mode, forming two copper transition layers with the thickness of about 12nm on the surfaces of the two copper process layers in a magnetron sputtering mode, forming two copper functional layers with the thickness of about 1031nm on the surfaces of the two copper transition layers in a water electroplating mode, and forming two chromium protective layers 160 with the thickness of about 32nm on the surfaces of the two functional layers in a water electroplating mode.

Wherein, the technological parameters of the evaporation coating are as follows: placing the coil stock into a vacuum chamber of a vacuum evaporation coating machine, sealing the vacuum chamber, and gradually vacuumizing until the vacuum degree reaches 2 multiplied by 10^-2Pa, adopting a crucible high-frequency heating mode, a resistance heating mode or an electron beam heating mode as an evaporation source, wherein the evaporation source evaporation raw material is metal copper, the purity is more than or equal to 99.9 percent, the winding speed is controlled at 200m/min, and evaporated atoms or molecules form a layer of coating on the surface of the functional layer.

The technological parameters of magnetron sputtering are as follows: putting the coil stock into a vacuum chamber of a vacuum magnetron sputtering coating machineSealing the vacuum chamber, and gradually vacuumizing until the vacuum degree reaches 7 multiplied by 10^-3Pa, introducing Ar gas serving as a process sputtering gas, controlling the flow rate of Ar to be 800SCCM, coating a film on the functional layer on the surface of the film by utilizing magnetron sputtering, wherein the target material is nickel or chromium or nickel alloy or chromium alloy, the purity of the target material is more than or equal to 99.99 percent, the winding speed is controlled to be 40m/min, and sputtered ions form a magnetron sputtering coating on the surface of the functional layer.

The technological parameters of the water electroplating are as follows: placing the coil stock in a water plating line unreeling machine, carrying out tape transport through a traction film, gradually opening the internal microcirculation amount to 9 times/hour, controlling the solution temperature to be 25 +/-3 ℃, controlling the cooling water temperature to be 20 +/-2 ℃, and controlling the solution components to be: the copper sulfate concentration is 80g/L, the Cl concentration is 45PPM, the additive concentration is 300ml/1000Ah, the sulfuric acid concentration is 170g/L, then, according to the current applied to each conductive roller by the film, the total current is applied to 8500A, the film coating speed is 5m/min, the film has negative charges, and the copper ions of the solution receive 2 electrons on the surface of the film to be reduced into a copper simple substance, so that a copper layer is generated on the surface of the film.

Other embodiments and comparative specific process parameters are consistent with those provided above.

Example 2

The preparation method of the conductive film comprises the following steps:

the PP insulation layer with a thickness of about 2 μm was dried at a temperature of 100 ℃ to a moisture content of about 332.5 PPM. Copper process layers with the thickness of about 20nm are formed on the two surfaces of the OPP insulating layer in an evaporation coating mode, two copper transition layers with the thickness of about 13nm are formed on the surfaces of the two copper process layers in a magnetron sputtering mode, two copper functional layers with the thickness of about 1033nm are formed on the surfaces of the two copper transition layers in a water electroplating mode, and two chromium protective layers 160 with the thickness of about 30nm are formed on the surfaces of the two functional layers in a water electroplating mode.

Example 3

The preparation method of the conductive film comprises the following steps:

copper process layers with the thickness of about 22nm are formed on the two surfaces of a PP insulating layer with the thickness of about 2 mu m and the water content of about 2152PPM in an evaporation coating mode, two copper transition layers with the thickness of about 11nm are formed on the surfaces of the two copper process layers in a magnetron sputtering mode, two copper functional layers with the thickness of about 1035nm are formed on the surfaces of the two copper transition layers in an evaporation coating mode, and two chromium protective layers 160 with the thickness of about 35nm are formed on the surfaces of the two functional layers in a water electroplating mode.

Example 4

The preparation method of the conductive film comprises the following steps:

forming copper process layers with the thickness of about 20nm on two surfaces of a PP insulating layer with the thickness of about 2 mu m and the water content of about 2152PPM in a water electroplating mode, forming two copper transition layers with the thickness of about 19nm on the surfaces of the two copper process layers in a magnetron sputtering mode, forming two copper functional layers with the thickness of about 1034nm on the surfaces of the two copper transition layers in an evaporation coating mode, and forming two chromium protective layers 160 with the thickness of about 33nm on the surfaces of the two functional layers in a water electroplating mode.

Example 5

The preparation method of the conductive film comprises the following steps:

forming copper process layers with the thickness of about 21nm on two surfaces of a PP insulating layer with the thickness of about 2 mu m and the water content of about 2152PPM in an evaporation coating mode, forming two copper transition layers with the thickness of about 6nm on the surfaces of the two copper process layers in a magnetron sputtering mode, forming two copper functional layers with the thickness of about 1031nm on the surfaces of the two copper transition layers in a water electroplating mode, and forming two chromium protective layers 160 with the thickness of about 34nm on the surfaces of the two functional layers in a water electroplating mode.

Example 6

The preparation method of the conductive film comprises the following steps:

the PP insulation layer with a thickness of about 2 μm was dried at a temperature of 100 ℃ to a moisture content of about 332.5 PPM. The method comprises the steps of forming nickel bonding layers 120 with the thickness of about 15nm on two surfaces of an OPP insulating layer in a magnetron sputtering mode, forming two copper process layers with the thickness of about 24nm on the surfaces of the two nickel bonding layers 120 in an evaporation coating mode, forming two copper transition layers with the thickness of about 14nm on the surfaces of the two copper process layers in a magnetron sputtering mode, forming two copper functional layers with the thickness of about 1041nm on the surfaces of the two copper transition layers in a water electroplating mode, and forming two chromium protective layers 160 with the thickness of about 31nm on the surfaces of the two functional layers in a water electroplating mode.

Example 7

The preparation method of the conductive film comprises the following steps:

the PP insulation layer with the thickness of about 2 μm is dried at 100 ℃ so that the water content of the insulation layer is about 332.5 PPM. Copper bonding layers 120 with the thickness of about 14nm are formed on the two surfaces of the OPP insulating layer in a magnetron sputtering mode, copper process layers with the thickness of about 23nm are formed on the surfaces of the two nickel bonding layers 120 in an evaporation coating mode, copper transition layers with the thickness of about 13nm are formed on the surfaces of the two copper process layers in a magnetron sputtering mode, copper functional layers with the thickness of about 1040nm are formed on the surfaces of the two copper transition layers in a water electroplating mode, and chromium protective layers 160 with the thickness of about 32nm are formed on the surfaces of the two functional layers in a water electroplating mode.

Example 8

The preparation method of the conductive film comprises the following steps:

the method comprises the steps of forming copper bonding layers 120 with the thickness of about 13nm on two surfaces of a PP insulating layer with the thickness of about 2 mu m and the water content of about 2152PPM in a magnetron sputtering mode, forming two copper process layers with the thickness of about 22nm on the surfaces of the two nickel bonding layers 120 in an evaporation coating mode, forming two copper transition layers with the thickness of about 15nm on the surfaces of the two copper process layers in a magnetron sputtering mode, forming two copper functional layers with the thickness of about 1046nm on the surfaces of the two copper transition layers in a water electroplating mode, and forming two chromium protective layers 160 with the thickness of about 29nm on the surfaces of the two functional layers in a water electroplating mode.

Comparative example 1

The preparation method of the conductive film comprises the following steps:

copper process layers with the thickness of about 25nm are formed on the two surfaces of the PP insulating layer with the thickness of about 2 mu m and the water content of about 2152PPM in an evaporation coating mode, two copper functional layers with the thickness of about 1039nm are formed on the surfaces of the two copper transition layers in a water electroplating mode, and two chromium protective layers 160 with the thickness of about 33nm are formed on the surfaces of the two functional layers in a water electroplating mode.

Comparative example 2

The preparation method of the conductive film comprises the following steps:

copper transition layers with the thickness of about 11nm are formed on two surfaces of a PP insulating layer with the thickness of about 2 mu m and the water content of about 2152PPM in a magnetron sputtering mode, two copper functional layers with the thickness of about 1042nm are formed on the surfaces of the two copper transition layers in a water electroplating mode, and two chromium protective layers 160 with the thickness of about 34nm are formed on the surfaces of the two functional layers in a water electroplating mode.

Experimental example 1

The surface morphologies of the conductive films prepared in examples 1, 4 and 5 and the conductive film prepared in comparative example 1 were examined using a Scanning Force Microscope (SFM) and a Scanning Electron Microscope (SEM). Wherein, FIG. 2 is a scanning force microscope image of the conductive film; fig. 2 (a) is a scanning force microscope photograph of the conductive film produced in example 4, fig. 2 (b) is a scanning force microscope photograph of the conductive film produced in example 1, fig. 2 (c) is a scanning force microscope photograph of the conductive film produced in example 5, and fig. 2 (d) is a scanning force microscope photograph of the conductive film produced in comparative example 1. FIG. 3 is a scanning electron micrograph of a conductive film; fig. 3 (a) is a scanning electron micrograph of the conductive film produced in example 4, fig. 3 (b) is a scanning electron micrograph of the conductive film produced in example 1, fig. 3 (c) is a scanning electron micrograph of the conductive film produced in example 5, and fig. 3 (d) is a scanning electron micrograph of the conductive film produced in comparative example 1. As can be seen from fig. 2 and 3, the conductive films of examples 1, 4, and 5 have a copper transition layer, uniform particles of surface morphology, substantially uniform asperities, compact arrangement, good densification, and no cracks. The thickness of the copper transition layer is between 10nm and 20nm, and the surface appearance is better. The conductive film of comparative example 1 had no copper transition layer, had uneven surface morphology particles, and had defects such as cracks and irregularities.

The light transmittance of the conductive films prepared in examples 1, 4 and 5 and the conductive film prepared in comparative example 1 was examined. Wherein, FIG. 4 is a dark field diagram of the conductive film; the upper left corner of fig. 4 is a dark field pattern of the conductive film prepared in example 4, the upper right corner of fig. 4 is a dark field pattern of the conductive film prepared in example 1, the lower left corner of fig. 4 is a dark field pattern of the conductive film prepared in example 5, and the lower right corner of fig. 4 is a dark field pattern of the conductive film prepared in comparative example 1. FIG. 5 is a bright field diagram of a conductive film; the top left corner of fig. 5 is a bright field pattern of the conductive film prepared in example 4, the bottom right corner of fig. 5 is a bright field pattern of the conductive film prepared in example 1, the bottom left corner of fig. 5 is a bright field pattern of the conductive film prepared in example 5, and the bottom right corner of fig. 5 is a bright field pattern of the conductive film prepared in comparative example 1. The light field image and the dark field image are obtained by shooting through a microscope, wherein in the light field image, the background is bright, and the target is dark; in the dark field map, the background is dark and the target is bright. Fig. 6 is a photograph of a finished conductive film, which was taken with a 300 lumen color uniformized flat panel lamp at a focal length of 200 mm. The top left corner of fig. 6 is a photograph of a finished conductive film prepared in example 4, the bottom right corner of fig. 6 is a photograph of a finished conductive film prepared in example 1, the bottom left corner of fig. 6 is a photograph of a finished conductive film prepared in example 5, and the bottom right corner of fig. 6 is a photograph of a finished conductive film prepared in comparative example 1. It should be noted that the large pore in the lower right-hand diagram of fig. 4 and the large pore in the lower right-hand diagram of fig. 5 is a defective pore of the membrane itself, and is not used as an evaluation criterion for light transmittance and compactness thereof, and fig. 6 is different from the position of the sample selected in fig. 4 and 5. Other small holes may be used to indicate that light is transmitted in the drawing, and the reason for this may be that the formed copper layer is not uniform, relatively loose, and has poor denseness. As can be seen from fig. 4, 5, and 6, the conductive films of examples 1, 4, and 5 have a copper transition layer, which is less likely to transmit light, better in uniformity, and better in denseness. And the thickness of the copper transition layer is 10-20nm, so that the compactness is better. The conductive film of comparative example 1, which has no copper transition layer, has a large light-transmitting hole and is poor in denseness.

Experimental example 2

The adhesion and the compactness of the conductive films provided in examples 1 to 8 and comparative examples 1 to 2 were examined, and the production costs (base cost a, other costs are expressed by a factor a) of the conductive films of different kinds were compared to obtain table 3.

Wherein, the test mode of density does: (1) under a fixed test environment and a backlight source, testing the illumination intensity of a fixed position by using an illuminometer, wherein the illumination intensity is A; (2) the same step (1) is carried out, a completely opaque plate is used up, a backlight book is shielded, and an illumination value is tested and is B; (3) a testing step, namely placing the film to be tested on a backlight plate, and reading an illumination count value as C; (4) and calculating the density as follows: 1- (C-B)/(A-B)

The adhesion was tested in the following manner: (1) 3M adhesive tape with fixed model, wherein the fixed pinch roller is pressed firmly against the surface of the film; (2) on a tensile machine, at an angle of 180 ° antiparallel. In the adhesive force data, different pulling speeds are tested, and the larger the speed is, the better the adhesive force is on the premise that the surface layer is not peeled; x represents very low adhesion and could not be tested.

TABLE 3 Properties of the conductive films

As can be seen from table 1, in comparison with examples 1 to 8 and comparative examples 1 to 2, the cost of producing the thermally conductive film is reduced without forming the process layer or the transition layer, but the obtained thermally conductive film has low density and poor conductivity, and cannot meet the requirements of some devices for the electrically conductive film.

Comparing example 1 with example 2, it is known that, in the case where no adhesive layer is formed, baking the PP film to reduce the water content of the PP film can effectively increase the adhesive force of the conductive film without substantially adversely affecting other properties of the conductive film.

As is clear from comparison between example 1 and example 3, in the case of the transition layer formed by magnetron sputtering, the density of the conductive film is not affected regardless of whether the functional layer is formed by electroplating with water or by vapor deposition, but the adhesion is increased to some extent by forming the functional layer by vapor deposition.

As is clear from comparison between example 1 and example 4, the thickness of the transition layer is increased, so that the density of the conductive film can be effectively increased, and the influence on other properties is not great.

As compared with embodiment 5, in embodiment 1, the thickness of the transition layer is reduced, which not only reduces the density of the conductive layer, but also reduces the conductivity of the conductive film, and conversely increases the manufacturing cost of the conductive film.

Comparing example 2 with example 6, it is known that when the PP film is baked to reduce the water content of the PP film and form the adhesive layer, the density of the conductive film can be further increased and the adhesive force thereof can be effectively improved, and accordingly, the manufacturing cost thereof can be increased to a certain extent, but the production of some devices which have high requirements for the conductive film can be satisfied.

In comparison between example 6 and example 7, it is found that when copper is used as the adhesive layer and the material of the adhesive layer is the same as the material of the process layer, the transition layer, and the functional layer, the conductive film is more dense, but the adhesive strength of the copper adhesive layer is slightly poor.

Comparing example 7 with example 8, it is understood that even though the copper adhesive layer is used, the adhesion of the conductive film obtained without baking the PP film is poor, and it is explained that the adhesion of the conductive film is slightly less affected by only providing the adhesive layer, and the adhesion of the conductive film can be made better by providing the adhesive layer while controlling the water content of the insulating layer.

The above description is only a few examples of the present application and is not intended to limit the present application, and various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A conducting film is characterized by comprising an insulating layer, wherein a bonding layer, a metal layer and a protective layer are sequentially arranged on the surface of the insulating layer;

the bonding layer is one of a Ti metal layer, a W metal layer, a Cr metal layer, a Cu metal layer and an alloy layer thereof;

the protective layer is a conductive non-metal protective layer or an inert metal protective layer; the metal of the inert metal protective layer is Cr or Cr alloy; the non-metal protective layer is a glucose complex layer or a potassium dichromate layer.

2. The conductive film of claim 1, wherein the bonding layer has a thickness of 2-40 nm.

3. The conductive film of claim 1, wherein the protective layer has a thickness of 0.1 to 100 nm.

4. The conductive film of claim 1, wherein the metal layer has a thickness of 50 to 3000 nm.

5. The conductive film of claim 1, wherein the metal layer is a copper layer.