Transparent conductive film, touch panel, and method for manufacturing the same

Abstract

The present application relates to a transparent conductive film, a first hard coating layer and / or a second hard coating layer containing particles, the particles comprising a bottom surface in a planar structure, and the bottom surface is arranged to face the surface of the substrate. The particles make the surface of the first metal layer and / or the second metal layer form a plurality of protrusions. Therefore, when the transparent conductive film is rolled, the plurality of protrusions can make the two adjacent metal layers form point contact, thereby preventing mutual adhesion. Moreover, the bottom surface of the particles is arranged to face the surface of the substrate, and the bottom surface is in a planar structure. Therefore, the contact between the particles and the substrate becomes surface contact, and the contact area is increased. When the transparent conductive film is rolled, the pressure exerted by the particles on the surface of the substrate is fixed, but due to the increased contact area, the pressure exerted by the particles on the substrate is smaller, thereby effectively avoiding damage to the substrate. In addition, the present application also provides a touch screen and a preparation method thereof.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of capacitive touch screen, in particular to a transparent conductive film, a touch screen and a preparation method thereof. BACKGROUND

[0002] The transparent conductive film is a core element of the capacitive touch screen. With the rapid development of intelligent terminals, the demand for transparent conductive films is also increasing. The transparent conductive film generally includes a substrate and a hard coating layer, a conductive layer and a metal layer arranged on both sides of the substrate. At present, since the amorphous polymer film has the advantages of less birefringence and uniformity compared with the crystalline polymer film, most of the transparent conductive films use the substrate formed by the amorphous polymer film.

[0003] The amorphous polymer film is more fragile than the crystalline polymer film, and its surface is more susceptible to damage. When the transparent conductive film is rolled to be in a cylindrical shape, there is a problem that the metal layers of adjacent transparent conductive films are bonded and pressed to each other. Therefore, a transparent conductive film in which particles are added to the hard coating layer to form protrusions on the surface of the metal layer appears. The protrusions can form point contact between adjacent metal layers, thereby avoiding bonding and pressing.

[0004] At present, the particles added to the hard coating layer are generally spherical or irregular particles, and the lower surface of the particles is in contact with the surface of the substrate. Therefore, the contact between the particles and the substrate is point contact. When the transparent conductive film is rolled, the pressure of the particles on the substrate is too large, thereby easily causing damage to the substrate. SUMMARY

[0005] Therefore, it is necessary to provide a transparent conductive film, a touch screen and a preparation method thereof capable of effectively preventing damage to the substrate in view of the problem that the existing transparent conductive film is susceptible to damage to the substrate during rolling.

[0006] A transparent conductive film comprises:

[0007] a substrate comprising a first surface and a second surface arranged oppositely;

[0008] a first hard coating layer, a first transparent conductive layer and a first metal layer formed on the first surface in sequence;

[0009] a second hard coating layer, a second transparent conductive layer and a second metal layer formed on the second surface in sequence;

[0010] the first hard coating layer and / or the second hard coating layer contains a plurality of particles to form a plurality of protrusions on the surface of the first metal layer and / or the second metal layer;

[0011] The particle includes a bottom surface in a planar structure, and the bottom surface is arranged towards the surface of the substrate.

[0012] Since the bottom surface of the particle is arranged towards the surface of the substrate, and the bottom surface is in a planar structure, the contact between the particle and the substrate becomes surface contact, and the contact area is increased. When the transparent conductive film is rolled, the pressure applied by the particle to the surface of the substrate is fixed, but since the contact area is increased, the pressure applied by the particle to the substrate is smaller, thereby effectively avoiding damage to the substrate.

[0013] In addition, since the contact area is increased, the adhesion of the particle is also increased.

[0014] In one embodiment, the substrate is a polyalkylene or polycarbonate or polyethylene terephthalate film.

[0015] The two types of films can meet the requirements of the birefringence and its deviation of the substrate, and are easy to obtain. Therefore, the cost of the transparent conductive film can be reduced.

[0016] In one embodiment, the distribution density of the protrusions is 100-3000 / mm 2 .

[0017] When the distribution density of the protrusions is too large, the haze value of the transparent conductive film is too large, the light transmittance is reduced, and the appearance and optical effect of the transparent conductive film are seriously affected. If the distribution density of the protrusions is too small, the anti-blocking effect is limited. Within the above roughness and density range, the transparent conductive film can better balance the anti-blocking and optical effect.

[0018] In one embodiment, the material of the particle is the same as that of the first hard coating and the second hard coating.

[0019] That is, the optical parameters of the suspended particle and the first hard coating and the second hard coating (hereinafter collectively referred to as hard coating) are also the same. Therefore, at the connection interface between the suspended particle and the hard coating, the light propagation is less affected, and the suspended particle and the hard coating are closer to a whole. When the light passes through the hard coating containing the suspended particle, the distortion of the propagation path is smaller. Therefore, the transparent conductive film can achieve the purpose of anti-blocking and anti-pressing, and also avoid the adverse effect on the optical performance.

[0020] In one embodiment, the height of the plurality of protrusions in the direction perpendicular to the surface of the first metal layer and / or the second metal layer is 0.1-0.5 μm.

[0021] The higher the height of the protrusion, the better the anti-sticking effect. However, as the height increases, the size of the suspended particles needs to increase accordingly, which results in an increase in the haze value of the transparent conductive film, and after a certain degree, it will seriously affect the optical effect of the transparent conductive film. Within the above height range, the transparent conductive film can better balance the anti-sticking and optical effects.

[0022] In one embodiment, the particle further comprises a top surface extending along the edge of the bottom surface and having a smooth curved surface structure, and the top surface is arranged to face away from the surface of the substrate.

[0023] The shape of the top surface determines the surface shape of the protrusion. Since the top surface is a smooth curved surface, the surface of the protrusion is relatively flat, thereby avoiding the formation of sharp protrusions such as edges on the surface of the protrusion. When the transparent conductive film is rolled up and the protrusion forms a support between two adjacent metal layers, it can effectively prevent damage to the surface of the metal layer caused by the protrusion structure on the surface of the protrusion.

[0024] In one embodiment, the center of gravity of the particle is located on a line connecting the center of the bottom surface to the top surface, and the center of gravity is located at one end of the line close to the bottom surface.

[0025] That is, the center of gravity is closer to the bottom surface. In the preparation of the transparent conductive film, a layer of fluid adhesive resin is first arranged on the surface of the substrate by coating; before the adhesive resin is cured, pre-prepared particles are sprayed thereon; the particles naturally settle under the action of gravity until they come into contact with the surface of the substrate; finally, the adhesive resin is cured to obtain a hard coating layer containing the particles 15.

[0026] Since the center of gravity of the particle is closer to the bottom surface, similar to the principle of a tilting bucket, the particle can autonomously flip over under the action of gravity during the settling process, and the bottom surface is directed towards the surface of the substrate 11. Therefore, without taking other operations, the orientation of the particles can be achieved, thereby effectively simplifying the preparation process of the transparent conductive film.

[0027] In one embodiment, the particle is semi-spherical and / or semi-cylindrical.

[0028] Since the semi-spherical and semi-cylindrical particles are easy to process and shape, it is beneficial to reduce the cost of the transparent conductive film.

[0029] A touch screen made of the transparent conductive film according to any one of the preferred embodiments, the touch screen comprising a touch area and a lead area, the first metal layer and the second metal layer being located in the lead area; the touch area comprising a first electrode etched from the first transparent conductive layer and a second electrode etched from the second transparent conductive layer; the lead area comprising a first lead etched from the first metal layer and the first transparent conductive layer located in the lead area, and a second lead etched from the second metal layer and the second transparent conductive layer located in the lead area.

[0030] In the touch screen, the first lead and the second lead are directly etched from the first metal layer, the second metal layer, the first transparent conductive layer and the second transparent conductive layer. Therefore, the leads electrically connected to the first electrode and the second electrode are not formed by silk printing. Compared with the conventional touch screen, the width of the electrode leads directly formed by photolithography can be further reduced, and thus the touch screen has a narrow frame.

[0031] A method for manufacturing a touch screen, comprising the steps of:

[0032] providing a transparent conductive film according to any one of the preferred embodiments;

[0033] etching the first metal layer and the second metal layer to expose the first transparent conductive layer and the second transparent conductive layer of the touch area, and form a metal lead pattern located in the lead area;

[0034] etching the first transparent conductive layer and the second transparent conductive layer to form a first electrode and a second electrode located in the touch area, and form a transparent lead pattern located in the lead area, the metal lead pattern and the transparent lead pattern together constituting an electrode lead.

[0035] In the method for manufacturing a touch screen, the first electrode, the second electrode and the electrode lead electrically connected to the first electrode and the second electrode are directly etched from the first metal layer, the second metal layer, the first transparent conductive layer and the second transparent conductive layer. Therefore, the leads are not formed by silk printing, thereby effectively simplifying the process and improving the processing efficiency. Moreover, the touch screen manufactured by the method has a narrow frame. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 A schematic view of the layer structure of the transparent conductive film in the preferred embodiments of the present application;

[0037] Figure 2 A schematic view of the layer structure of the transparent conductive film in the preferred embodiments of the present application; Figure 1 A schematic view of the layer structure of the transparent conductive film in the preferred embodiments of the present application;

[0038] Figure 3 for Figure 1 A schematic diagram of particles in a transparent conductive film;

[0039] Figure 4 This is a schematic diagram of the stacked structure of a transparent conductive film in another embodiment of the present invention;

[0040] Figure 5 This is a schematic diagram of the stacked structure of the touch screen in a preferred embodiment of the present invention;

[0041] Figure 6 This is a flowchart illustrating the touchscreen manufacturing method in a preferred embodiment of the present invention. Detailed Implementation

[0042] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0043] It should be noted that when a component is said to be "fixed to" another component, it can be directly attached to the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0045] Please see Figure 1 and Figure 2 In a preferred embodiment of the present invention, the transparent conductive film 10 includes a substrate 11, a first hard coating layer 12, a first transparent conductive layer 13, a first metal layer 14, a second hard coating layer 22, a second transparent conductive layer 23, and a second metal layer 24.

[0046] Substrate 11 includes a first surface disposed opposite to the substrate ( Figure 1 The upper surface shown) and the second surface ( Figure 1The substrate 11 is formed of an amorphous polymer film. Since the amorphous polymer film has a small birefringence and is uniform, color unevenness in the transparent conductive film 10 of the present application can be eliminated. The in-plane birefringence of the amorphous polymer film used in the present application is preferably 0 to 0.001, and further preferably 0 to 0.0005. The deviation of the in-plane birefringence of the amorphous polymer film used in the present application is preferably 0.0005 or less, and further preferably 0.0003 or less.

[0047] The foregoing birefringence and deviation thereof can be achieved by selecting an appropriate kind of amorphous polymer film. Specifically, in the present embodiment, the substrate 11 is a polyalkene or polycarbonate or polyethylene terephthalate film. These two types of films can satisfy the requirements for birefringence and deviation thereof. The thickness of the substrate 11 formed of an amorphous polymer film is 20 μm to 200 μm.

[0048] The first hard coat layer 12, the first transparent conductive layer 13, and the first metal layer 14 are formed in this order on the first surface of the substrate 11. The second hard coat layer 22, the second transparent conductive layer 23, and the second metal layer 24 are formed in this order on the second surface of the substrate 11. Among them:

[0049] The first hard coat layer 12 protects the first surface of the substrate 11. The first hard coat layer 12 contains a binder resin. The binder resin contains, for example, a curable resin composition based on ultraviolet rays, electron rays. The curable resin composition preferably contains a polymer obtained by addition reaction of glycidyl acrylate-based polymer with acrylic acid. Alternatively, the curable resin composition preferably contains a multifunctional acrylate polymer (pentaerythritol, dipentaerythritol, etc.). The curable resin composition further contains a polymerization initiator.

[0050] The first transparent conductive layer 13 is formed on the surface of the first hard coat layer 12. The first transparent conductive layer 13 is formed of a material having a high transmittance (80% or more) in the visible light region (380 nm to 780 nm) and a surface resistance value (unit: Ω / m 2 ) of 500 Ω / m 2 The following layers are formed. The thickness of the first transparent conductive layer 13 is preferably 15 nm to 100 nm, and more preferably 15 nm to 50 nm. The first transparent conductive layer 13 is formed of, for example, any one of indium tin oxide (ITO), indium tin oxide, or an indium oxide-zinc oxide composite.

[0051] The first metal layer 14 is formed on the surface of the first transparent conductive layer 13. When the transparent conductive film of the present application is used in a touch panel, for example, the first metal layer 14 is used to form a wiring on the outside of the touch input area. As for the material forming the first metal layer 15, copper and silver are representative, and any other metal with excellent conductivity can also be used. The thickness of the first metal layer 14 is preferably 50 nm to 500 nm, and more preferably 100 nm to 300 nm.

[0052] Further, the second hard coating layer 22, the second transparent conductive layer 23 and the second metal layer 24 have the same film layer structure, function and material composition as the first hard coating layer 12, the first transparent conductive layer 13 and the first metal layer 14, respectively, and thus will not be described again here.

[0053] In addition, the first hard coating layer 12 and / or the second hard coating layer 22 contain a plurality of particles 15 to form a plurality of protrusions 16 on the surface of the first metal layer 14 and / or the second metal layer 24. Please refer to Figure 3 The particles 15 include a bottom surface 151 in a planar structure, which is arranged towards the surface of the substrate 11.

[0054] Specifically, the particles 15 can be distributed irregularly or in a predetermined rule (e.g. uniformly) in the first hard coating layer 12 and / or the second hard coating layer 22.

[0055] The particles 15 can be contained only in the first hard coating layer 12 or the second hard coating layer 22, so as to obtain a transparent conductive film 10 with protrusions 16 formed on one side; or the particles 15 can be contained in both the first hard coating layer 12 and the second hard coating layer 22, so as to obtain a transparent conductive film 10 with protrusions 16 formed on both sides.

[0056] Take the first hard coating layer 12 as an example for illustration:

[0057] In the direction perpendicular to the substrate 11, the size of the particles 15 is greater than the thickness of the flat area 17 of the first hard coating layer 12, so that the particles protrude from the surface of the first hard coating layer 12. The area of the first hard coating layer 12 where the particles 15 are arranged forms a convex area, while the area of the first hard coating layer 12 where the particles 15 are not arranged forms a flat area 17. Since the first transparent conductive layer 13 and the first metal layer 14 are sequentially arranged on the surface of the first hard coating layer 12, the surface shapes of the two layers are the same as that of the first hard coating layer 12. Therefore, in the area of the first metal layer 14 corresponding to the particles 14, a plurality of protrusions 16 are formed.

[0058] Similarly, when the second hard coating layer 22 contains particles 15, the surface of the second metal layer 24 can also form a plurality of protrusions 16.

[0059] When the transparent conductive film 10 is manufactured by a roll to roll process, the surface of the first metal layer 14 and / or the second metal layer 24 is formed with a plurality of protrusions 16 due to the particles 15. Therefore, when the transparent conductive film 10 is rolled, the plurality of protrusions 16 can form point contacts between two adjacent metal layers, thereby preventing the two metal layers from sticking to each other and being pressed together.

[0060] Furthermore, the bottom surface of the particle 15 is planar. Therefore, the contact between the particle 15 and the substrate 11 is surface contact, and the contact area is increased. When the transparent conductive film 10 is rolled, the pressure applied by the particle 15 to the surface of the substrate 11 is fixed, but because the contact area is increased, the pressure applied by the particle 15 to the substrate 11 is smaller, thereby effectively preventing damage to the substrate 11.

[0061] In this embodiment, the first hard coating layer 12 and the second hard coating layer 22 both contain the particles 15, so that the surface of the first metal layer 14 and the surface of the second metal layer 24 are both formed with a plurality of protrusions 16.

[0062] That is, the obtained transparent conductive film 10 has a plurality of protrusions 16 on both sides. Therefore, when the transparent conductive film 10 is rolled, the number of point contacts between two adjacent metal layers is increased, so that the effect of preventing the two metal layers from sticking to each other and being pressed together is better.

[0063] Please refer to Figure 4 In another embodiment, either the first hard coating layer 12 or the second hard coating layer 22 contains the particles 15, so that the surface of the first metal layer 14 or the surface of the second metal layer 24 is formed with a plurality of protrusions 16.

[0064] That is, the obtained transparent conductive film 10 has a plurality of protrusions 16 on only one side. Therefore, while the effect of preventing the two metal layers from sticking to each other and being pressed together is achieved, the shadow of the two particles 15 is prevented from overlapping each other, thereby reducing the haze and improving the optical effect of the transparent conductive film 10.

[0065] In this embodiment, the particles 15 are made of the same material as the first hard coating layer 12 and the second hard coating layer 22.

[0066] Because the particles 15 are made of the same material as the first hard coating layer 12 and the second hard coating layer 22 (hereinafter collectively referred to as the hard coating layer), the optical parameters of the particles 15 and the hard coating layer are the same. Therefore, at the connection interface between the particles 15 and the hard coating layer, the light propagation is less affected, and the particles 15 and the hard coating layer are closer to being a whole. When the light passes through the first hard coating layer 12 and the second hard coating layer 22 containing the particles 15, the distortion of the light propagation path is smaller. Therefore, while the transparent conductive film 10 achieves the purpose of preventing the two metal layers from sticking to each other and being pressed together, the optical performance of the transparent conductive film 10 is also prevented from being adversely affected.

[0067] Further, in the present embodiment, the material of the particles 15 is silica, silicone polymer, acrylic polymer or styrene polymer.

[0068] The above materials have the advantages of good light transmittance and easy availability, and the use of the particles 15 can reduce the cost under the premise of meeting the performance requirements. Of course, other suitable materials can also be selected according to actual performance and cost requirements.

[0069] In the present embodiment, the particles 15 further include a top surface 153 extending along the edge of the bottom surface 151 and having a smooth curved surface structure, and the top surface 153 is arranged to face away from the surface of the substrate 11.

[0070] Specifically, the shape of the top surface 153 determines the surface shape of the protrusions 16. Since the top surface 153 is a smooth curved surface, the surface of the protrusions 16 is also relatively flat, thereby avoiding the formation of sharp protrusions such as edges on the surface of the protrusions 16. When the transparent conductive film 10 is rolled up and the protrusions 16 form supports between two adjacent metal layers, damage to the surface of the metal layer caused by the protrusions on the surface of the protrusions 16 can be effectively prevented.

[0071] Specifically, in the present embodiment, the particles 15 are hemispherical and / or semicylindrical. In the first hard coating layer 12 and the second hard coating layer 22, the shape of the particles 15 can be one or a mixture of multiple different shapes. Among them, the hemispherical and semicylindrical particles are easy to process and form, thereby being beneficial to reduce the cost.

[0072] It can be understood that in other embodiments, the shape of the particles 15 is not limited to the above two types. For example, the particles 15 can also be circular truncated cone-shaped, conical, etc.

[0073] Further, in the present embodiment, the center of gravity of the particles 15 is located on a line connecting the center of the bottom surface 151 to the top surface 153, and the center of gravity is located at one end of the line close to the bottom surface 151.

[0074] That is, the center of gravity is closer to the bottom surface 151. The forming process of the first hard coating layer 12 and the second hard coating layer 22 (hereinafter collectively referred to as the hard coating layer) is as described above. In the preparation of the transparent conductive film 10, a layer of fluid adhesive resin is first arranged on the surface of the substrate 11 by coating; before the adhesive resin is cured, the pre-prepared particles 15 are sprayed thereon; the particles 15 naturally settle under the action of gravity until they come into contact with the surface of the substrate 11; finally, the adhesive resin is cured, and the hard coating layer containing the particles 15 is obtained.

[0075] Since the center of gravity of the particle 15 is closer to the bottom surface 151, the particle 15 can be automatically flipped under the action of gravity during the settling process, and the bottom surface 151 is directed toward the surface of the base material 11 (of course, based on probability, not all particles 15 are flipped to have the bottom surface 151 directed toward the base material 11, but the majority of the particles 15 have the bottom surface 151 directed toward the base material 11). Therefore, the arrangement of the particles 15 can be achieved without taking other operations, thereby effectively simplifying the manufacturing process of the transparent conductive film 10.

[0076] In order to achieve better anti-adhesion and anti-pressing effects, the surface roughness of the first metal layer 14 and the second metal layer 24 and the density of the protrusions 16 have corresponding requirements.

[0077] In the embodiment, the surface arithmetic average roughness Ra of the first metal layer 14 and the second metal layer 24 is 0.0025-0.025 μm. In addition, the distribution density of the protrusions 16 is 100-3000 / mm 2 .

[0078] When the distribution density of the protrusions 16 is too large, the haze value of the transparent conductive film 10 is too large, the light transmittance is reduced, and the appearance and optical effect of the transparent conductive film 10 are seriously affected. If the distribution density of the protrusions 16 is too small, the anti-adhesion effect is limited. Within the above roughness and density range, the transparent conductive film 10 can better balance the anti-adhesion and optical effects.

[0079] The surface arithmetic average roughness Ra and the distribution density of the first metal layer 14 and the second metal layer 24 can be changed by adjusting the shape, size and content of the particles 15.

[0080] Further, in the embodiment, the height of the plurality of protrusions 16 in the direction perpendicular to the surface of the first metal layer 14 and / or the second metal layer 24 is 0.1-0.5 μm.

[0081] The height of the protrusion 16 refers to the height of the protrusion 16 protruding from the surface of the first metal layer 14 and / or the second metal layer 24. Since the particle 15 is small in size, it is difficult to accurately control the height of each protrusion 16. Therefore, the height of the protrusion 16 can be controlled within the above height range. It should be noted that in actual production, since it is difficult to accurately control each particle 15, it is inevitable that a small part of the particles 15 will form protrusions 16 with a height outside the above range. However, the influence of this part of the protrusions 16 can be ignored.

[0082] In general, the higher the height of the protrusions 16, the better the anti-sticking effect. However, as the height increases, the size of the particles 15 needs to be increased accordingly, which results in an increase in the haze value of the transparent conductive film 10, and after a certain degree, it will seriously affect the optical effect of the transparent conductive film 10. Within the above height range, the transparent conductive film 10 can better balance the anti-sticking and optical effects.

[0083] The height of the protrusions 16 can be changed by adjusting the size of the particles 15 and the degree of suspension of the particles 15.

[0084] The transparent conductive film 10 described above, the particles 15 form a plurality of protrusions 16 on the surface of the first metal layer 14 and / or the second metal layer 24. Therefore, when the transparent conductive film 10 described above is rolled up, the plurality of protrusions 16 can form point contact between the two adjacent metal layers, thereby preventing them from sticking to each other. Moreover, the bottom surface 151 of the particle 15 is arranged towards the surface of the substrate 11, and the bottom surface 151 is a planar structure. Therefore, the contact between the particle 15 and the substrate 11 becomes a surface contact, and the contact area increases. When the transparent conductive film 10 is rolled up, the pressure exerted by the particle 15 on the surface of the substrate 11 is fixed, but due to the increase in the contact area, the pressure exerted by the particle 15 on the substrate 11 is smaller, thereby effectively avoiding damage to the substrate 11.

[0085] In addition, the present application also provides a touch screen. Please refer to Figure 5 The touch screen 200 in the preferred embodiment of the present application is made of the transparent conductive film 10 in the above embodiment. Wherein:

[0086] The touch screen 200 includes a touch area 210 and a lead area 220. Specifically, the touch area 210 is located in the middle of the touch screen 200, and the lead area 220 is arranged around the circumference of the touch area 210. The first metal layer 14 and the second metal layer 24 are located in the lead area 220.

[0087] The touch area 210 includes a first electrode 211 and a second electrode 212. Wherein, the first electrode 211 is etched from the first transparent conductive layer 13; the second electrode 212 is etched from the second transparent conductive layer 23. The first electrode 211 and the second electrode 212 are etched into an electrode pattern. Specifically, the electrode pattern is generally in the shape of a long strip and vertically intersects to form a grid shape, and the opposite first electrode 211 and second electrode 212 form two poles of a capacitor structure.

[0088] The lead region 220 includes a first lead 221 and a second lead 222. The first lead 221 is etched from the first metal layer 14 and the first transparent conductive layer 13 located in the lead region 220; the second lead 222 is etched from the second metal layer 24 and the second transparent conductive layer 23 located in the lead region 220. The first lead 221 and the second lead 222 are double-layer structures, thereby realizing electrical connection with the first electrode 211 and the second electrode 212.

[0089] In the above touch screen, the first lead 221 and the second lead 222 are directly etched from the first metal layer 14, the second metal layer 24, the first transparent conductive layer 13 and the second transparent conductive layer 23. Therefore, the width of the electrode lead directly formed by the photolithography process can be further reduced without silk printing, and thus the touch screen has a narrow frame.

[0090] Please refer to Figure 6 The application further provides a preparation method of the touch screen, which includes steps S310-S330.

[0091] Step S310: providing a transparent conductive film.

[0092] Specifically, the transparent conductive film is the transparent conductive film 10 in the above embodiment, which includes the first transparent conductive layer 13 and the first metal layer 14 arranged in layers, and the second transparent conductive layer 23 and the second metal layer 24 arranged in layers.

[0093] Step S320: etching the first metal layer 14 and the second metal layer 24 to expose the first transparent conductive layer 13 and the second transparent conductive layer 23 in the touch region, and form a metal lead pattern in the lead region.

[0094] Specifically, the metal lead pattern can be formed on the surface of the metal layer by one photolithography process. The metal lead pattern is arranged along the edge of the touch screen. After etching the metal layer, the first transparent conductive layer 13 and the second transparent conductive layer 24 in the lower layer are partially exposed.

[0095] Step S330: etching the first transparent conductive layer 13 and the second transparent conductive layer 23 to form the first electrode 211 and the second electrode 212 in the touch region, and form a transparent lead pattern in the lead region, the metal lead pattern and the transparent lead pattern together constituting an electrode lead.

[0096] Specifically, the exposed portions of the first transparent conductive layer 13 and the second transparent conductive layer 24 are etched by another yellow light process to form electrode patterns, so that the first electrode 211 and the second electrode 212 are obtained. Meanwhile, the first metal layer 14 and the second metal layer 24 in the form of metal lead patterns are superimposed on the first transparent conductive layer 13 and the second transparent conductive layer 23 in the lead area, respectively, so that the first lead 221 and the second lead 222 in a double-layer structure are formed. The first lead 221 and the second lead 222 are electrically connected to the first electrode 211 and the second electrode 212, respectively.

[0097] In the preparation of the touch screen by the above method, the first metal layer 14, the second metal layer 24, the first transparent conductive layer 13 and the second transparent conductive layer 23 are etched directly, so that the first electrode 211, the second electrode 212 and the first lead 221 and the second lead 222 electrically connected to the first electrode 211 and the second electrode 212 are obtained. Therefore, it is not necessary to form the leads by silk printing, so that the process is effectively simplified and the processing efficiency is improved. Moreover, the touch screen prepared by the above method has a narrow frame.

[0098] The technical features of the above-described embodiments can be combined in any manner. To make the description concise, all possible combinations of the technical features in the above-described embodiments are not described, but as long as the combinations of the technical features do not contradict each other, they should be considered within the scope of the present disclosure.

[0099] The above-described embodiments only express several embodiments of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the scope of protection of the present application should be subject to the appended claims.

Claims

1. A transparent conductive film, comprising: a substrate comprising a first surface and a second surface arranged oppositely; a first hard coat layer, a first transparent conductive layer and a first metal layer formed successively on the first surface; a second hard coat layer, a second transparent conductive layer and a second metal layer formed successively on the second surface; wherein the first hard coat layer and / or the second hard coat layer comprises a plurality of particles to form a plurality of protrusions on the surface of the first metal layer and / or the second metal layer; wherein the particles comprise a bottom surface in a planar structure, the bottom surface being arranged towards the surface of the substrate; the particles further comprise a top surface in a smooth curved surface structure extending along the edge of the bottom surface, the top surface being arranged away from the surface of the substrate; the center of gravity of the particles is located on a line connecting the center of the bottom surface to the top surface, and the center of gravity is located at the end of the line close to the bottom surface; the particles are in a semi-spherical and / or semi-cylindrical shape; the substrate is a polyalkylene or polycarbonate or polyethylene terephthalate film; the particles are made of the same material as the first hard coat layer and the second hard coat layer; the height of the plurality of protrusions is 0.1-0.5 μm in the direction perpendicular to the surface of the first metal layer and / or the second metal layer.

2. A touch screen made of the transparent conductive film according to any one of claims 1-5, the touch screen comprising a touch area and a lead area, the first metal layer and the second metal layer being located in the lead area; the touch area comprising a first electrode etched from the first transparent conductive layer and a second electrode etched from the second transparent conductive layer; the lead area comprising a first lead etched from the first metal layer and the first transparent conductive layer in the lead area, and a second lead etched from the second metal layer and the second transparent conductive layer in the lead area.

3. A method for manufacturing a touch screen, comprising the steps of: providing a transparent conductive film according to any one of claims 1-5; etching the first metal layer and the second metal layer to expose the first transparent conductive layer and the second transparent conductive layer in the touch area, and to form a metal lead pattern in the lead area; etching the first transparent conductive layer and the second transparent conductive layer to form a first electrode and a second electrode in the touch area, and to form a transparent lead pattern in the lead area, the metal lead pattern and the transparent lead pattern together forming an electrode lead. ​ ​ ​ ​ ​ ​ 2. The transparent conductive film according to claim 1, wherein ​ 3. The transparent conductive film according to claim 1, wherein The distribution density of the protrusions is 100-3000 / mm 2 .

4. The transparent conductive film according to claim 1, wherein ​ 5. The transparent conductive film according to claim 1, wherein ​ 6. A touch screen, characterized by ​ 7. A method for manufacturing a touch screen, characterized by, ​ ​ ​ ​

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