CN111599511A

CN111599511A - Transparent conductive film and preparation method thereof

Info

Publication number: CN111599511A
Application number: CN202010555855.6A
Authority: CN
Inventors: 雷贝; 彭颖杰; 徐林; 王新媛; 姜锴; 潘克菲; 徐晔
Original assignee: Nuovo Film Inc; Suzhou Huige Photoelectric Technology Co ltd
Current assignee: Nuovo Film Inc; Suzhou Huige Photoelectric Technology Co ltd
Priority date: 2020-06-17
Filing date: 2020-06-17
Publication date: 2020-08-28

Abstract

The invention relates to a transparent conductive film and a preparation method thereof, wherein the transparent conductive film comprises a transparent substrate, the substrate comprises a visible area and a wiring area positioned around the visible area; the working electrode is positioned on the substrate and consists of a nano metal wire, a nano metal rod or a nano metal film, the working electrode positioned in the wire area is provided with a lapping groove exposing the section of the working electrode, the depth of the lapping groove is not less than two thirds of the thickness of the working electrode, or the lapping groove penetrates through the working electrode along the thickness direction; the protective layer is positioned on one side of the working electrode, which is far away from the substrate, and a conductive channel communicated with the lap joint groove is arranged on the protective layer; the electric connecting piece is positioned in the lapping groove and the conductive channel and is made of solidified conductive slurry; and the electrode lead is positioned on one side of the protective layer, which is far away from the working electrode, and is electrically connected with the corresponding working electrode through an electric connector.

Description

Transparent conductive film and preparation method thereof

Technical Field

The invention relates to the field of transparent conductive films, in particular to a transparent conductive film capable of increasing the thickness of a surface protective layer and a preparation method thereof.

Background

The nano silver wire conducting film is a basic material for manufacturing nano silver wire large-size touch screens, light-adjustable films, flexible touch screens and other electronic products.

The basic structure of the nano silver wire conductive film comprises a base material, the nano silver wire conductive film and a protective layer, wherein the protective layer has the main effects of improving the structural strength of the nano silver wire layer, avoiding scratching, blocking external corrosive substances and improving the stability of a nano silver wire material. However, in the existing application, the electrical signal of the nano silver wire layer is led out from the right top of the conductive layer of the nano silver wire, and contact conduction is formed after silver paste printing, so that the surface conductivity of the nano silver wire needs to be emphasized, and the contact resistance of the silver paste in an area of about 1 square millimeter is required to be less than 100 ohms.

The conventional implementation methods include two methods, one is that the protective layer is thin enough, the conductive grid formed by the nano silver wires has points exposed out of the protective layer, and after the silver paste is printed, conductive filler particles in the silver paste can be in direct contact with the nano silver wires; the other is that after the silver paste is printed by silk, after a solvent in the silver paste is dissolved to destroy a surface protection layer, the conductive filler particles in the silver paste and the nano silver wire are in close contact for conduction, wherein the contact comprises direct contact and quantum tunneling type contact, namely when the distance between two conductive particles is in a nano level, electrons can jump between two conductors for conduction.

The conduction of the two modes limits the thickness of the surface protective layer of the nano silver wire, so that the nano silver wire is difficult to form real effective protection.

In view of the above, it is desirable to provide a transparent conductive film and a method for manufacturing the same to solve the above problems.

Disclosure of Invention

The invention aims to provide a transparent conductive film capable of increasing the thickness of a surface protective layer and a preparation method thereof.

In order to achieve the purpose, the invention adopts the following technical scheme:

a transparent conductive film comprising:

the substrate comprises a visible area and a wiring area positioned around the visible area;

the working electrode is positioned on the substrate and consists of a nano metal wire, a nano metal rod or a nano metal film, a lapping groove exposing the section of the working electrode is arranged on the structure of the working electrode positioned in the wiring area, the depth of the lapping groove is not less than two thirds of the thickness of the working electrode, or the lapping groove penetrates through the working electrode along the thickness direction;

the protective layer is positioned on one side of the working electrode, which is far away from the substrate, and a conductive channel communicated with the lap joint groove is arranged on the protective layer;

the electric connecting piece is positioned in the lapping groove and the conductive channel and is solidified conductive slurry;

and the electrode lead is positioned on one side of the protective layer, which deviates from the working electrode, and the electrode lead is electrically connected with the corresponding working electrode through the electric connecting piece.

Further, the nano metal wire is a nano silver wire with the diameter of 5 nm-100 nm and the length of 15 mu m-25 mu m.

Further, the thickness of the protective layer is not less than 10 nm.

Further, the overlapping groove is a groove, or the overlapping groove comprises a plurality of independent sub-grooves;

and/or the conductive channel is a channel or the conductive channel comprises several independent sub-channels.

Further, the electrode lead is an enameled wire, and the enameled wire comprises a lapping part, wherein the metal wire is exposed outwards;

or, the electrode lead is an electrode wire formed by screen printing or ink-jet printing of conductive paste solidification;

or the electrode lead is an electrode wire formed by coating conductive paste such as silver paste into a conductive film and then etching the conductive film.

Further, the transparent conductive film further comprises a separation layer positioned on the substrate, and the working electrode is positioned on one side of the separation layer, which is far away from the substrate; or, the transparent conductive film further comprises a separation layer positioned on the substrate and a resin layer positioned on one side of the separation layer, which is deviated from the substrate, and the working electrode is positioned on one side of the resin layer, which is deviated from the separation layer.

In order to achieve the above object, the present invention further provides a method for preparing a transparent conductive film, comprising the steps of:

s1, forming a working electrode on the substrate, wherein the working electrode is composed of a nano metal wire, a nano metal rod or a nano metal film;

s2, forming a cross section of a lapping groove on the working electrode in the wiring area of the substrate to expose the working electrode, wherein the depth of the lapping groove is not less than two thirds of the thickness of the working electrode, or the lapping groove penetrates through the working electrode along the thickness direction;

s3 forming a protective layer on the side of the working electrode, which faces away from the substrate;

s4, forming a conductive channel on the protective layer in the wiring area of the substrate;

s5, filling conductive slurry into the conductive channels and the lap joint grooves which are communicated in a one-to-one correspondence mode, and solidifying the conductive slurry to form an electric connector;

s6, arranging electrode leads on one side of the protective layer, which is far away from the working electrode, wherein the electrode leads are electrically connected with the corresponding working electrode through the electric connectors.

Further, the thickness of the protective layer is not less than 10 nm.

Further, after the working electrode is formed, the conductive channel and the overlapping groove are formed simultaneously; or, the lapping groove and the conductive channel are respectively and independently formed.

Further, the temperature in the process of forming the lapping groove is not higher than 300 ℃; and/or, the temperature during the formation of the conductive channel is not higher than 300 ℃.

Further, the method of forming the lap joint groove includes mechanical damage, ultrasonic, plasma ablation, shock wave, hole preparation, chemical etching, the mechanical damage includes scratching, tearing, scraping, drilling, cutting, grinding, vibrating.

Furthermore, an enameled wire is arranged on one side, away from the working electrode, of the protective layer and serves as the electrode lead, the enameled wire comprises a lapping part, exposed outwards, of the metal wire, and the lapping part is electrically connected with the electric connecting piece; or screen printing or ink-jet printing conductive paste on one side of the protective layer, which is far away from the working electrode, and curing to form an electrode lead, wherein the electrode lead is electrically connected with the electric connecting piece.

Further, sequentially forming a separation layer on the substrate, and then forming the working electrode on the separation layer; alternatively, a separation layer and a resin layer are formed in this order on the substrate, and then the working electrode is formed on the resin layer.

Compared with the prior art, the invention has the beneficial effects that: according to the transparent conductive film, the cross section of the working electrode is exposed outwards through the lap joint groove formed in the conductive electrode, and the cross section is in electrical contact with the electrode lead through the electric connecting piece, so that the conventional surface electrical connection mode is changed, the thickness of the protective layer can be increased, the application range of the electrode lead is expanded, and even if the conductive material with larger contact resistance is used continuously after the original screen printing conductive paste is printed, the conductive material can be used continuously.

Drawings

FIG. 1 is a schematic structural diagram of a substrate, a working electrode and a protective layer;

FIG. 2 is a schematic illustration of the protective layer of FIG. 1 after screen printing of a plurality of silver paste segments thereon;

FIG. 3 is a schematic view of the protective layer of FIG. 1 after forming a plurality of breaking points and then screen printing silver paste blocks;

FIG. 4 is a schematic view of the structure of FIG. 1 after forming a conductive via and a landing slot;

FIG. 5 is a schematic illustration of the addition of conductive paste into the conductive vias and landing pads of FIG. 4;

fig. 6 is a schematic view of a transparent conductive film formed after electrode leads are laid on the protective layer of fig. 5.

100-transparent conductive film, 1-substrate, 2-working electrode, 21-lap joint groove, 3-protective layer, 31-conductive channel, 4-electric connector, 5-electrode lead, 6-silver paste block, and 7-damage point.

Detailed Description

The present application will now be described in detail with reference to specific embodiments thereof as illustrated in the accompanying drawings. These embodiments are not intended to limit the present application, and structural, methodological, or functional changes made by those skilled in the art according to these embodiments are included in the scope of the present application.

In the various illustrations of the present application, certain dimensions of structures or portions may be exaggerated relative to other structures or portions for ease of illustration and, thus, are provided to illustrate only the basic structure of the subject matter of the present application.

Referring to fig. 1 and fig. 4 to fig. 6, a transparent conductive film 100 of the present invention includes a substrate 1, a working electrode 2 located on the substrate 1, a protective layer 3 located on a side of the working electrode 2 away from the substrate 1, and electrode leads 5 located on a side of the protective layer 3 away from the working electrode 2, wherein the electrode leads 5 penetrate through the protective layer 3 and are connected to the working electrode in a one-to-one correspondence manner.

The substrate 1 may be a base material used in a manufacturing process, or may be a part of a product to which the transparent conductive electrode 100 is applied. Taking the substrate applied in the manufacturing process as an example, the substrate 1 is transparent, including but not limited to glass, plastic plate, transparent film, and the transparent film includes but not limited to PET film.

In addition, the substrate 1 includes a visible region and a routing region located around the visible region for arranging the electrode leads 5. The visible region can also be understood as a working region, for example, when the transparent conductive film 100 is applied to a touch screen, the visible region is a touch region; for example, when the transparent conductive film 100 is applied to an electrochromic device such as a light-adjusting film or a light-adjusting glass, the visible region is a light-adjusting display region.

The thickness of the working electrode 2 is generally 30 nm-100 nm, the working electrode 2 is a patterned conductive structure formed by a nano metal wire, a nano metal rod or a nano metal film, and different working electrodes 2 are insulated, and the insulation can be realized by arranging the insulating structures at intervals or in the middle. It will be appreciated by those skilled in the art that the working electrode 2 generally covers the viewing area and that the end of the working electrode 2 is located at the routing area to facilitate electrical connection with the electrode lead 5.

The nano metal wire or the nano metal rod can be coated on the surface of the substrate 1 in a solution form to form a continuous conductive film layer, and preferably, the nano metal wire is a nano silver wire with the diameter of 5 nm-100 nm and the length of 15 μm-25 μm, has high conductivity and high transparency. Alternatively, the working electrode 2 is a nano metal film formed by magnetron sputtering, vacuum deposition, or the like, and has reliable conductivity.

The working electrode 2 located in the wiring area is provided with a lap joint groove 21 exposing the cross section of the working electrode 2, the cross section forms at least part of the groove wall of the lap joint groove 21, and the lap joint groove 21 is opened back to the substrate 1.

The cross section extends from the side of the working electrode 2 departing from the substrate 1 to the side of the substrate 1, and the projection of the cross section on the surface perpendicular to the working electrode 2 is a straight line, an arc line or other irregular lines as long as the nano metal wire, the nano metal rod or the nano metal film can be exposed or protruded from the cross section into the overlapping groove 21.

Further, the depth of the overlapping groove 21 is not less than two thirds of the thickness of the working electrode to form an effective conductive surface; preferably, the overlapping groove 21 penetrates the working electrode in the thickness direction, has a large cross-sectional area, and can be electrically connected with the electrode lead 5 effectively and stably.

In addition, the overlapping groove 21 may be a single groove, or the overlapping groove 21 may include several independent sub-grooves.

The bridging groove 21 is located at the middle position of the working electrode 2, is an internal groove, and is generally a closed figure, such as a circle, when viewed from the top of the transparent conductive film 100; or the overlapping groove 21 is opened at the edge of the working electrode 2, and is an edge groove, and is generally in an open pattern, such as a semicircular arc, when viewed from the top of the transparent conductive film 100.

The protective layer 3 is usually a transparent resin layer, which can improve the structural strength of the working electrode 2, avoid scratching, block external corrosive substances, and improve the stability of the nano metal wire, or the nano metal rod, or the nano metal film. The sheet resistance of the side, away from the working electrode 2, of the protective layer 3 is 0.1-500 ohm/sq measured by using an eddy current sheet resistance meter, and the resistance cannot be measured by using a four-probe sheet resistance meter.

Specifically, the protective layer 3 is the entire surface of the working electrode 2 on the side away from the substrate 1, or the protective layer 3 is a patterned protective layer 3, and only the working electrode 2 is protected.

The protective layer 3 is provided with a conductive channel 31 communicated with the overlapping groove 21, and preferably, the conductive channel 31 and the overlapping groove 21 are positioned on the same straight line, so that synchronous formation is facilitated, and conductive filler is filled conveniently.

In addition, the conductive channel 31 is a single channel, or the conductive channel 31 includes several independent sub-channels. Any form of the said overlapping slot 21 can communicate with any form of conductive path 31; preferably, when the overlapping groove 21 is a groove, the conductive channel 31 is a channel; when the overlapping groove 21 is formed by several sub-grooves, the conductive channel 31 is formed by several sub-channels, and the sub-channels correspond to the sub-grooves one to one.

Filling conductive slurry into the conductive channel 31 and the overlapping groove 21 and solidifying the conductive slurry to form an electric connecting piece 4, wherein the electric connecting piece 4 is directly contacted with the section of the working electrode 2 exposed in the overlapping groove 21 and is electrically connected with the section of the working electrode 2 so as to lead out an electric signal of the section of the working electrode 2 to one side of the protective layer 3, which is far away from the working electrode 2; the conventional surface electrical connection mode is changed, so that the thickness of the protective layer 3 can be increased, for example, the thickness of the protective layer 3 is not less than 10nm, preferably not less than 1 μm; and the application range of the electrode lead 5 is expanded, and even the original conductive material with larger contact resistance after silk-screen printing of the conductive paste can be continuously used.

The electric conduction mechanism of the electric connection piece 4 and the section comprises: part of the end parts of the nano metal wires or the nano metal rods extend out of the cross section into the lapping grooves 21 and are electrically connected with the electric connecting pieces 4; or after the overlapping groove 21 is formed, a conductive film layer made of metal nano materials including a nano metal wire or a nano metal rod and the like or the nano metal film is turned outwards at the overlapping groove 21 to form a micron-sized conductive surface which is electrically connected with the electric connecting piece 4; or after the conductive paste is filled into the lapping groove 21, the cross section has better side invasion, so that the electric connector 4 is electrically connected with the working electrode 2.

The conductive paste includes, but is not limited to, conductive carbon paste, conductive silver paste, and when the nano metal wire is a nano silver wire, the conductive silver paste is preferably used, and the contact resistance is low.

The electrode lead 5 is located on the protective layer 3 at the wiring area, the electrode lead 5 is electrically connected with the corresponding working electrode 2 through the electric connecting piece 4, and each electrode lead 5 corresponds to one working electrode 2.

In a specific embodiment, the electrode lead 5 is an enameled wire, the enameled wire includes a metal wire and an insulating layer coated outside the metal wire, and the metal wire can be insulated without an additional insulating glue layer, so as to form an enameled wire group with a small wire pitch, and even the enameled wires can be directly overlapped together, that is, the pitch between the enameled wires can be reduced to 0, so that the width of the wire running area can be reduced. In the invention, the enameled wire comprises a lapping part exposed outwards from the metal wire, and the lapping part is electrically connected with the working electrode 2 through the electric connecting piece 4.

In another specific embodiment, the electrode lead 5 is an electrode wire formed by curing conductive paste such as silver paste printed by screen printing or inkjet printing; alternatively, the electrode lead 5 is an electrode wire formed by coating a conductive film with a conductive paste such as silver paste and etching the conductive film. And, this method reduces the requirement for silver paste, even if the contact resistance of the formed electrode lead 5 is more than 100 ohm per square millimeter can be used.

Further, the transparent conductive film 100 further includes a separation layer on the substrate 1, and the working electrode 2 is located on a side of the separation layer facing away from the substrate 1, so that the working electrode 2 can be peeled off on the substrate 1 and transferred to a desired device.

Preferably, the transparent conductive film 100 further includes a separation layer on the substrate 1, and a resin layer on a side of the separation layer away from the substrate 1, the working electrode 2 is located on a side of the resin layer away from the separation layer, and the resin layer is in direct contact with the separation layer, so as to avoid damaging the nano metal wire, the nano metal rod, or the nano metal film in the working electrode 2 during the separation process.

The invention also provides a preparation method of the transparent conductive film, which comprises the following steps:

s1, forming a working electrode 2 on the substrate 1, wherein the working electrode 2 is a conductive structure composed of a nano metal wire, a nano metal rod or a nano metal film;

s2, forming a cross section of the working electrode in which the working electrode 2 is exposed by a lap joint groove 21 in the wiring region of the substrate 1, wherein the depth of the lap joint groove 21 is not less than two thirds of the thickness of the working electrode, or the lap joint groove 21 penetrates the working electrode 2 in the thickness direction;

s3 forming a protective layer 3 on a side of the working electrode 2 facing away from the substrate 1;

s4, forming a conductive path 31 on the protective layer 3 in the routing area of the substrate 1;

s5, filling conductive slurry into the conductive channels 31 and the overlapping grooves 21 which are communicated in a one-to-one correspondence manner, and solidifying the conductive slurry to form the electric connecting piece 4;

s6, an electrode lead 5 is disposed on a side of the protective layer 3 facing away from the working electrode 2, and the electrode lead 5 is electrically connected to the corresponding working electrode 2 through the electrical connector 4.

Wherein, S1-S6 are for descriptive convenience only and do not represent a sequence of steps; according to the different specific processes, the sequence relationship between steps S1 and S2 is: the bridging groove 21 may be formed simultaneously with the formation of the working electrode 2, or the conductive path 31 may be formed after the formation of the working electrode 2; the sequence relationship between step S3 and step S4 is: the conductive path 31 may be formed at the same time as the formation of the protective layer 3, or the conductive path 31 may be formed after the formation of the protective layer 3; step S2 and step S4 may be performed separately, or may be performed simultaneously after step S3; step S5 and step S6 may be interchanged.

Moreover, in the method, the process and the sequence of the steps are mainly described, and the positions, forms, and configurations of the substrate 1, the working electrode 2, the bonding groove 21, the protective layer 3, the conductive channel 31, the electrical connector 4, and the electrode lead 5 are the same as those described in the transparent conductive film 100, and are not described in detail.

Specifically, step S1 includes: s11, coating a layer of conducting film on the substrate 1 by adopting nanometer materials such as nanometer metal wires or nanometer metal rods, wherein the coating process comprises but is not limited to the adoption of high-precision slit extrusion coating equipment; s12 etching the conductive film to form a patterned electrode, wherein the etching process includes, but is not limited to, laser thin film etching, gas etching, discharge etching, chemical etching, physical etching, and mechanical etching.

Depending on the specific process, when the etching process of step S12 is the same as that of step S2 of forming the bonding groove 21, the etching process and the bonding groove may be performed simultaneously; of course, the two steps can be carried out, and the sequence can be interchanged. After the protective layer 3 is formed in step S3, the etching process in step S12 may be performed to form the patterned protective layer 3 corresponding to the working electrode 2; of course, the step S3 may be performed after the step S12 to form the entire surface of the protective layer 3.

Or step S1 includes: the patterned working electrode 2 of the nanometal wire or the nanometal rod is screen printed or sprayed directly on the substrate 1 according to a predetermined pattern. Based on this method, after the step S1, the step S3 can form a whole surface of the passivation layer 3, or form the patterned passivation layer 3 by a mask method.

The nano-metal wire or rod material used in step S1 is usually a solution.

In a preferred embodiment, the nano metal wire is a nano silver wire with the diameter of 5 nm-100 nm and the length of 15 μm-25 μm, and the thickness of wet films coated by various processes is 2 μm-10 μm so as to ensure continuous and stable conductivity.

Alternatively, in step S1, a patterned nano metal film may be directly formed by a mask by magnetron sputtering or vacuum evaporation to form the working electrode 2; or a nano metal film is firstly formed on the substrate 2 by adopting a magnetron sputtering or vacuum evaporation mode, and then the patterned working electrode 2 is formed by etching.

In the present invention, the overlapping groove 21 and the conductive path 31 may be formed independently.

Preferably, after the working electrode 2 is formed, the conductive path 31 and the overlapping groove 21 are formed at the same time; the process is briefly described, and the conductive channel 31 is connected with the lap joint groove 21 in an alignment way, so that the subsequent filling of the conductive slurry is facilitated. Simultaneous formation here means that the same process step is used for completion.

Further, the inventor finds in research that the working electrode 2 is in the nanometer level, an inappropriate grooving process can cause the non-conducting cross section, and after many thought and improvements, the temperature in the process of forming the overlapping groove 21 is not higher than 300 ℃, and/or the temperature in the process of forming the conductive channel 31 is not higher than 300 ℃, so as to avoid the phenomenon that the cross section of the working electrode 2 is not conducting due to the heat effect. Preferably, the temperature is not higher than 180 ℃, so that the nano metal wire, the nano metal rod or the nano metal film can not break, and the conductive stability is ensured.

The method for forming the conductive channel 31 and/or the overlap groove 21 comprises mechanical damage, ultrasonic wave, laser etching, plasma ablation, shock wave, hole preparation and chemical etching, wherein the mechanical damage comprises scratching, scraping, drilling, cutting, grinding and vibration, and the laser etching process is preferably femtosecond laser to ensure the conductivity of the section.

In step S6, the method for laying the electrode lead 5 may be any one of the prior art, or a new electrode lead 5 laying process may be designed.

For example, an enameled wire may be used as the electrode lead 5, the enameled wire includes a lap portion where the metal wire is exposed outwards, and the laying process is to lay the enameled wire on a side of the protection layer 3 away from the working electrode 2 and electrically connect the lap portion with the electrical connection member 4.

The electrode lead 5 can also be made of conductive paste such as silver paste, the requirement on the conductivity of the conductive paste is greatly reduced, and the arrangement method comprises but is not limited to the following steps: on the side of the protective layer 3 facing away from the working electrode 2, a screen-printed or ink-jet printed conductive paste is cured to form an electrode lead 5. Or, coating conductive slurry on the side of the protective layer 3 departing from the working electrode 2 to form a conductive film layer, and then etching to form an electrode lead 5.

Further, the method for preparing the transparent conductive film further comprises the following steps: first, a separation layer is sequentially formed on the substrate 1, and then the working electrode 2 is formed on the separation layer, so that the working electrode 2 can be peeled off on the substrate 1 and transferred to a desired device.

Preferably, the method for preparing the transparent conductive film further comprises: a resin layer is formed on the separation layer, and then the working electrode 2 is formed on the resin layer. The resin layer is in direct contact with the separation layer, so that the nano metal wire or the nano metal rod in the working electrode 2 is prevented from being damaged in the separation process.

The transparent conductive film 100 and the method for manufacturing the same according to the present invention will be described below with reference to detailed examples.

Comparative example 1

Coating a coating liquid containing a nano silver wire on the surface of a transparent PET film by using high-precision slit extrusion coating equipment, wherein the diameter of the nano silver wire in the coating liquid is about 5-100 nm, the length is 15-25 mu m, and the solid content is 0.5%; the thickness of the coated wet film is 2 mu m-10 mu m, a metal grid layer containing nano silver wires is formed, the sheet resistance is 50ohm/sq after drying, and the visible light transmittance is not lower than 85%.

The protective layer 3 was prepared by coating a transparent UV curable resin solution using a high precision slit extrusion coating apparatus at a coating thickness of 1um, at which time the resistance could not be measured with a four probe sheet resistance meter, which was measured with an eddy current sheet resistance meter at 50 ohm/sq.

And (3) screen-printing conductive silver paste on the protective layer 3 to form silver paste blocks 6 with the thickness of about 5 micrometers-10 micrometers and the size of 2mm x 2mm, wherein the interval between each edge of each silver paste block 6 and the adjacent silver paste block 6 is 5mm, after drying and curing, measuring the resistance between each silver paste block 6, and displaying that the circuit is broken and each silver paste block 6 is not conductive.

Example 1, the difference from comparative example 1 is that:

after the protective layer 3 is formed, in a set silk-screen silver paste area, a tungsten needle is used for impacting and destroying the protective layer 3 and the metal mesh layer to form a plurality of breaking points 7 with the depth of about 1 μm to 50 μm and the diameter of 0.2mm, the plurality of breaking points 7 are uniformly distributed in the overlapping area, as shown in fig. 4, 10 breaking points 7 are formed in the embodiment, each breaking point 7 forms one sub-channel and one sub-groove on the protective layer 3, and according to the depth of the breaking point 7, the sub-groove destroys a part of the metal mesh layer close to the protective layer 3, or the sub-groove penetrates through the metal mesh layer.

And (3) printing conductive silver paste on the screen in the set screen printing silver paste area to form silver paste blocks 6 with the thickness of 5 mu m-10 um and the size of 1mm x 1mm, wherein the intervals between each edge of each silver paste block 6 and the adjacent silver paste block 6 are 2mm, and the silver paste is filled in the sub-channel and the sub-groove due to the adhesion and the fluidity of the silver paste.

After drying and curing, the resistance between the silver paste blocks 6 is measured, and the measured value is less than 50 ohms, which indicates that the silver paste blocks 6 are conducted with the metal grid layer formed by the nano silver wires.

As can be seen from comparison between comparative example 1 and example 1, when the bridging groove 21 is formed in the nano silver wire conductive film, the cross section of the nano silver wire conductive film has conductive properties, and the silver paste flowing into the bridging groove 21 and the cross section of the metal mesh layer can be electrically connected effectively and stably.

In summary, in the transparent conductive film 100 of the present invention, the cross section of the working electrode 2 is exposed outside through the overlapping groove 21 formed on the conductive electrode 2, and the cross section is electrically connected to the electrode lead 5 through the electrical connector 4, so that the conventional surface electrical connection manner is changed, the thickness of the protective layer 3 can be increased, the application range of the electrode lead 5 is expanded, and even if the conductive material with a large contact resistance is used after the original screen printing of the conductive paste, the conductive material can be used continuously.

It should be understood that although the present description refers to embodiments, not every embodiment contains only a single technical solution, and such description is for clarity only, and those skilled in the art should make the description as a whole, and the technical solutions in the embodiments can also be combined appropriately to form other embodiments understood by those skilled in the art.

The above-listed detailed description is only a specific description of a possible embodiment of the present invention and is not intended to limit the scope of the present invention, and equivalent embodiments or modifications made without departing from the technical spirit of the present invention are included in the scope of the present invention.

Claims

1. A transparent conductive film, comprising:

2. The transparent conductive film according to claim 1, wherein the nano metal wire is a nano silver wire having a diameter of 5nm to 100nm and a length of 15 μm to 25 μm.

3. The transparent conductive film according to claim 1, wherein the protective layer has a thickness of not less than 10 nm.

4. The transparent conductive film according to claim 1, wherein the overlapping groove is one groove, or the overlapping groove comprises several independent sub-grooves;

5. The transparent conductive film according to claim 1, wherein the electrode lead is an enameled wire including a bonding portion where a metal wire is exposed outward;

6. The transparent conductive film according to claim 1, further comprising a separation layer on the substrate, wherein the working electrode is located on a side of the separation layer facing away from the substrate;

or, the transparent conductive film further comprises a separation layer positioned on the substrate and a resin layer positioned on one side of the separation layer, which is deviated from the substrate, and the working electrode is positioned on one side of the resin layer, which is deviated from the separation layer.

7. A method for preparing a transparent conductive film is characterized by comprising the following steps:

s8, filling conductive slurry into the conductive channels and the lap joint grooves which are communicated in a one-to-one correspondence mode, and solidifying the conductive slurry to form an electric connector;

8. The method for producing a transparent conductive film according to claim 7,

the nano metal wire is a nano silver wire with the diameter of 5 nm-100 nm and the length of 15 mu m-25 mu m.

9. The method for producing a transparent conductive film according to claim 7, wherein the thickness of the protective layer is not less than 10 nm.

10. The method for producing a transparent conductive film according to claim 7, wherein the conductive channel and the bonding groove are formed simultaneously after the working electrode is formed; or, the lapping groove and the conductive channel are respectively and independently formed.

11. The method for producing a transparent conductive film according to claim 10, wherein a temperature during formation of the overlapping groove is not higher than 300 ℃;

and/or, the temperature during the formation of the conductive channel is not higher than 300 ℃.

12. The method for producing the transparent conductive film according to claim 10 or 11, wherein the method for forming the overlapping groove includes mechanical damage, ultrasonic wave, plasma ablation, shock wave, pre-hole, chemical etching, and the mechanical damage includes scratching, tearing, scraping, drilling, cutting, grinding, and vibrating.

13. The method for preparing the transparent conductive film according to claim 7, wherein an enameled wire is arranged on one side of the protective layer, which is away from the working electrode, and is used as the electrode lead, the enameled wire comprises a lap joint part, wherein the metal wire is exposed outwards, and the lap joint part is electrically connected with the electric connecting piece;

or screen printing or ink-jet printing conductive paste on one side of the protective layer, which is far away from the working electrode, and curing to form an electrode lead, wherein the electrode lead is electrically connected with the electric connecting piece.

14. The method for producing a transparent conductive film according to claim 7, wherein a separation layer is formed on the substrate in this order, and then the working electrode is formed on the separation layer;

alternatively, a separation layer and a resin layer are formed in this order on the substrate, and then the working electrode is formed on the resin layer.