Transparent Conductive Film, Touch Screen and Preparation Method Thereof

Abstract

The present invention relates to a transparent conductive film. The first optical adjustment layer and / or the second optical adjustment layer contains particles, and the outer surface of the particles has a surface concavo-convex structure, such that the outer surface thereof is a non-smooth curved surface. The particles cause multiple protrusions to be formed on the surface of the first metal layer and / or the second metal layer, thereby enabling the transparent conductive film to have an anti-sticking function. Since the outer surface of the particles is formed with a surface concavo-convex structure to make the outer surface of the particles a non-smooth curved surface. Therefore, the roughness of the outer surface of the particles increases. On the other hand, the contact area between the particles and the optical adjustment layer increases. And the adhesion of the particles is positively correlated with the roughness and the contact area. Therefore, the adhesion of the particles in the optical adjustment layer increases, thereby effectively preventing the particles from falling off. In addition, since the above-mentioned transparent conductive film does not include a hard coating as compared with a conventional conductive film, its optical effect can be effectively improved. In addition, the present invention also provides a touch screen and a method for preparing the same.

Description

Technical Field

[0001] The present invention relates to the technical field of capacitive touch screens, and particularly relates to a transparent conductive film, a touch screen and a preparation method thereof. Background Art

[0002] The transparent conductive film is a core component of the capacitive touch screen. With the rapid development of intelligent terminals, the demand for transparent conductive films is increasing day by day. The transparent conductive film generally includes a substrate and hard coatings, conductive layers and metal layers provided on both sides of the substrate. At present, since the amorphous polymer film has the advantages of less and uniform birefringence 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 easily damaged. When curling the transparent conductive film into a cylindrical shape, there will be problems of adhesion and crimping between the metal layers of adjacent transparent conductive films. Therefore, a transparent conductive film has emerged in which particles are added to the hard coating structure to form protrusions on the surface of the metal layer. The protrusions can make the adjacent metal layers form point contacts, thus avoiding adhesion and crimping.

[0004] However, the particles in the existing conductive films are generally spherical or ellipsoidal, and their surfaces are relatively smooth. Therefore, the adhesion of the particles in the film layer is limited. Moreover, after the particles are set, coating, drying and other steps are required to complete the preparation of the conductive film, which will easily cause the particles with poor adhesion to fall off, thereby affecting the anti-adhesion effect of the conductive film. Summary of the Invention

[0005] Based on this, it is necessary to provide a transparent conductive film, a touch screen and a preparation method thereof that can effectively enhance the adhesion of particles in view of the problem that particles in the existing transparent conductive film with anti-adhesion function are prone to fall off.

[0006] A transparent conductive film, comprising:

[0007] A substrate including a first surface and a second surface arranged opposite to each other;

[0008] A first optical adjustment layer, a first transparent conductive layer and a first metal layer sequentially formed on the first surface;

[0009] A second optical adjustment, a second transparent conductive layer and a second metal layer sequentially formed on the second surface;

[0010] The first optical adjustment layer and / or the second optical adjustment 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] Wherein, a surface concavo-convex structure is formed on the outer surface of the particle, so that the outer surface of the particle is a non-smooth curved surface.

[0012] Since a surface concavo-convex structure is formed on the outer surface of the particle, and the outer surface of the particle is a non-smooth curved surface. On the one hand, the roughness of the outer surface of the particle increases. On the other hand, the contact area between the particle and the optical adjustment layer increases. And the adhesion of the particle is positively correlated with the roughness and the contact area. Therefore, the adhesion of the particle in the optical adjustment layer increases, so that the particle shedding can be effectively prevented.

[0013] Compared with the traditional conductive film, the above transparent conductive film does not include a hard coating, and the particles are located in the optical adjustment layer (at least one of the first optical adjustment layer and the second optical adjustment layer). On the one hand, after omitting the hard coating, the film layer structure can be reduced, thereby reducing the light shielding. On the other hand, the optical adjustment layer itself has the function of adjusting the optical effect. Therefore, when light passes through the particles located in the optical adjustment layer, the refraction and scattering phenomena are enhanced. Therefore, the overall light transmittance of the above transparent conductive film increases, so that the optical effect can be effectively improved.

[0014] Moreover, after omitting the hard coating from the transparent conductive film, the film layer structure can be reduced, thereby simplifying the structure of the transparent conductive film. Therefore, it is beneficial to simplify the processing process of the transparent conductive film and reduce the cost.

[0015] Furthermore, in the traditional conductive film, the hard coating will release water vapor or organic solvents during the manufacturing process, resulting in poor crystallinity of the conductive layer (for example, the ITO layer) and uneven sheet resistance. However, since the transparent conductive film of the present invention does not include a hard coating, the released water vapor or organic solvents are reduced, thereby improving the crystallinity of the conductive layer, and further making its sheet resistance more uniform. Moreover, the brittleness of the transparent conductive film is reduced, greatly improving the slitting and winding process performance of the conductive film, so that cracking during punching of large sheets of materials can be effectively avoided.

[0016] In one embodiment, there is a gap between the plurality of particles and the surface of the substrate, and the particle size of the particles is smaller than the thickness of the flat area, and the flat area is an area where the first optical adjustment layer or the second optical adjustment layer is not provided with the particles.

[0017] In the existing conductive film with an anti-adhesion function, the particle size of the particles must be larger than the thickness of the hard coating to form protrusions on the surface of the metal layer. Therefore, the particle size of the particles is limited by the thickness of the hard coating and cannot be further reduced. However, the larger the particle size, the greater the haze value and the lower the light transmittance of the conductive film, thereby affecting the optical effect of the conductive film.

[0018] In this embodiment, since the particle size of the particles is smaller than the thickness of the optical adjustment layer. Therefore, the particle size of the particles is not limited by the thickness of the optical adjustment layer, and the particle size of the particles can be further reduced relative to the particle size of the particles in the existing anti-adhesion conductive film, thereby reducing the haze value and improving the light transmittance, and finally improving the optical effect.

[0019] In one embodiment, the proportion of the particles located in the first optical adjustment layer or the second optical adjustment layer in the particles is less than one-half.

[0020] As described above, since the adhesion of the particles in the optical adjustment layer increases. Therefore, even if the portion of the particles embedded in the optical adjustment layer is less than one-half of the whole particles, the stability of the particle adhesion will not be weakened. And the less the portion of the particles embedded in the optical adjustment layer, the smaller the particle size at the same protrusion height, so the shielding effect of the particles on light is weaker, thus further improving the optical effect.

[0021] In one embodiment, the thickness of the flat area is 45 to 145 nanometers.

[0022] Within this range, the optical adjustment effect of the optical adjustment layer is the best, and the optical effect of the transparent conductive film can be in the best state.

[0023] In one embodiment, the particles are made of the same material as the first optical adjustment layer and the second optical adjustment layer.

[0024] Since the particles are made of the same material as the first optical adjustment layer and the second optical adjustment layer (collectively referred to as the optical adjustment layer hereinafter), the optical parameters of the particles and the optical adjustment layer are also the same. Therefore, at the connection interface between the particles and the optical adjustment layer, the influence on the light propagation is small, and the particles and the optical adjustment layer are closer to an integral whole. When light passes through the optical adjustment layer containing particles, the distortion of its propagation route is small. Therefore, while achieving the purpose of anti-adhesion and anti-compression bonding, the transparent conductive film can also avoid adverse effects on its optical performance.

[0025] Moreover, since the materials are the same, the adhesion of the particles in the optical adjustment layer can be further enhanced.

[0026] In one embodiment, a plurality of strip-shaped grooves are formed on the outer surface of the particles to form the surface uneven structure.

[0027] By forming the grooves, the shielding effect of the particles on light can be reduced, thereby increasing the light transmittance of the optical adjustment layer, and further improving the optical effect of the transparent conductive film.

[0028] In one embodiment, the substrate is a cyclic olefin polymer film.

[0029] Cyclic olefin polymer (COP) is a new type of amorphous polymer material with high hardness and excellent light transmittance. However, it is very brittle. Therefore, hard coatings are often applied to its two surfaces to improve it. However, this conventional approach ignores the side effects of the hard coatings on subsequent crystallization. In this embodiment, since particles are added to the optical adjustment layer, its strength and toughness are increased, so it can protect the substrate. Therefore, even if the hard coating is omitted, COP material can be used to make the substrate, so that the substrate has the characteristics of high hardness and good light transmittance.

[0030] In one of the embodiments, the distribution density of the protrusions is 100 - 3000 pieces / mm 2 , and the height of the multiple protrusions is 0.1 - 0.5 μm.

[0031] When the distribution density of the protrusions is too large, the haze value of the transparent conductive film will be too large and the light transmittance will decrease, which will seriously affect the appearance and optical effect of the transparent conductive film. If the distribution density of the protrusions is too small, the anti - adhesion effect is limited. Within the above density range, the transparent conductive film can better balance the anti - adhesion and optical effects.

[0032] The higher the height of the protrusions, the better the anti - adhesion effect. However, as the height increases, the size of the particles needs to increase accordingly, resulting in an increase in the haze value of the transparent conductive film, and after reaching a certain level, 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 - adhesion and optical effects.

[0033] A touch screen is made of the transparent conductive film described in any one of the above - mentioned preferred embodiments. The touch screen includes a touch area and a lead area. The first metal layer and the second metal layer are located in the lead area; the touch area includes a first electrode etched from the first transparent conductive layer and a second electrode etched from the second transparent conductive layer; the lead area includes a first lead formed by etching the first metal layer and the first transparent conductive layer located in the lead area, and a second lead formed by etching the second metal layer and the second transparent conductive layer located in the lead area.

[0034] In the above 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, there is no need to form leads electrically connected to the first electrode and the second electrode by screen printing. Compared with traditional touch screens, since there is no need for screen printing, the width of the electrode leads directly formed by the yellow light process can be further reduced, so the touch screen has a narrow border.

[0035] A method for preparing a touch screen includes the steps:

[0036] Provide a transparent conductive film as described in any one of the above preferred embodiments;

[0037] Etch 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 form a metal lead pattern in the lead area;

[0038] Etch 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 form a transparent lead pattern in the lead area, and the metal lead pattern and the transparent lead pattern together constitute an electrode lead.

[0039] When preparing a touch screen by the above method, directly etching the first metal layer, the second metal layer, the first transparent conductive layer and the second transparent conductive layer can obtain the first electrode, the second electrode and the electrode leads electrically connected to the first electrode and the second electrode. Therefore, there is no need to use the screen printing method to form leads, thus effectively simplifying the process and improving the processing efficiency. Moreover, the touch screen prepared by the above method has a narrow border. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic diagram of the stacked structure of the transparent conductive film in a preferred embodiment of the present invention;

[0041] Figure 2 For Figure 1 An enlarged schematic diagram of a partial area A in the shown transparent conductive film;

[0042] Figure 3 For Figure 1 A schematic diagram of the structure of particles in the shown transparent conductive film;

[0043] Figure 4 It is a schematic diagram of the stacked structure of the transparent conductive film in another embodiment of the present invention;

[0044] Figure 5 It is a schematic diagram of the stacked structure of the touch screen in a preferred embodiment of the present invention;

[0045] Figure 6 It is a schematic diagram of the process flow of the method for preparing a touch screen in a preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0046] For the convenience of understanding the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. The preferred embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0047] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there can also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this invention belongs. The terms used herein in the description of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0049] Please refer to Figure 1 and Figure 2 , the transparent conductive film 10 in the preferred embodiment of the present invention includes a substrate 11, a first optical adjustment layer 12, a first transparent conductive layer 13, a first metal layer 14, a second optical adjustment layer 22, a second transparent conductive layer 23 and a second metal layer 24.

[0050] The substrate 11 includes a first surface ( Figure 1 the upper surface shown) and a second surface ( Figure 1 the lower surface shown) which are oppositely arranged. Among them, the first surface and the second surface are only for distinguishing the two surfaces of the substrate 11, and the positions of the first surface and the second surface can be interchanged. The substrate 11 is formed of an amorphous polymer film. Since the amorphous polymer film has a smaller and more uniform birefringence than the crystalline polymer film, the color unevenness in the transparent conductive film 10 of the present invention can be eliminated. The in-plane birefringence of the amorphous polymer film used in the present invention is preferably 0 to 0.001, and more preferably 0 to 0.0005. The deviation of the in-plane birefringence of the amorphous polymer film used in the present invention is preferably below 0.0005, and more preferably below 0.0003.

[0051] The foregoing birefringence and its deviation can be achieved by selecting a suitable type of amorphous polymer film. The thickness of the substrate 11 formed of the amorphous polymer film is 20 μm to 200 μm.

[0052] The first optical adjustment layer 12, the first transparent conductive layer 13 and the first metal layer 14 are sequentially formed on the first surface of the substrate 11. The second optical adjustment layer 22, the second transparent conductive layer 23 and the second metal layer 24 are sequentially formed on the second surface of the substrate 11. Among them:

[0053] The first optical adjustment layer 12 is used to improve the optical effect of the transparent conductive film 10. In the subsequent process, after patterning the first transparent conductive layer 13, the difference in reflectivity between the part with the first transparent conductive layer 13 and the part without it is reduced, making the pattern of the first transparent conductive layer 13 difficult to identify.

[0054] In addition, the first optical adjustment layer 12 is also used to improve the refraction of light when passing through different film layer structures. The refractive index of the first optical adjustment layer 12 is preferably set to a value between the refractive index of the substrate 11 and the refractive index of the first transparent conductive layer 13. Therefore, it can play a transitional role in the light propagation path. The material for forming the first optical adjustment layer 12 is, for example, a coating of one or several of silicone polymers, acrylate polymers, aromatic ring or naphthalene ring polymers, zirconium oxide, titanium oxide, and antimony oxide.

[0055] The first transparent conductive layer 13 is formed on the surface of the first optical adjustment layer 12. The first transparent conductive layer 13 has a high transmittance (above 80%) in the visible light region (380 nm to 780 nm), and the surface resistance value per unit area (unit: Ω / m 2 ) is 500 Ω / m 2 or less. The thickness of the first transparent conductive layer 13 is preferably 15 nm to 100 nm, 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 indium oxide - zinc oxide composite.

[0056] 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 invention is used for, for example, a touch panel, the first metal layer 14 is used to form wiring outside the touch input area. Regarding the material for 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, more preferably 100 nm to 300 nm.

[0057] Furthermore, the second optical adjustment layer 22, the second transparent conductive layer 23, and the second metal layer 24 have the same film layer structure, function, and physical properties as the first optical adjustment layer 12, the first transparent conductive layer 13, and the first metal layer 14, respectively, so they will not be described in detail here.

[0058] In addition, the first optical adjustment layer 12 and / or the second optical adjustment 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. Among them, the outer surface of the particle 15 is formed with a surface uneven structure (not marked in the figure) so that the outer surface of the particle 15 is a non-smooth curved surface.

[0059] Specifically, a smooth surface refers to a surface with a continuously varying tangent plane, while a non-smooth surface refers to a surface without a continuously varying tangent plane. Therefore, the outer surface of the particle 15 has protrusions or depressions. The particles 15 can be distributed irregularly or according to a preset rule (such as evenly) within the first optical adjustment layer 12 and / or the second optical adjustment layer 22. The particles 15 can be contained only within the first optical adjustment layer 12 or the second optical adjustment layer 22, so as to obtain a transparent conductive film 10 with protrusions 16 formed on one side; the particles 15 can also be contained within both the first optical adjustment layer 12 and the second optical adjustment layer 22, so as to obtain a transparent conductive film 10 with protrusions 16 formed on both sides.

[0060] Specifically in this embodiment, please refer to Figure 3 at the same time. A plurality of strip-shaped grooves 151 are formed on the outer surface of the particle 15 to form a surface concavo-convex structure.

[0061] By forming the grooves 151, a "hollow structure" can be formed inside the particle 15. Therefore, the blocking effect of the particle 15 on light can be reduced, thereby increasing the light transmittance of the optical adjustment layer, and further improving the optical effect of the transparent conductive film 10.

[0062] It should be noted that in other embodiments, forming the surface concavo-convex structure is not limited to the method of forming the grooves 151. For example, irregular protrusions or depressions can also be formed on the surface of the particle 15.

[0063] Taking the first optical adjustment layer 12 as an example for illustration:

[0064] The particle 15 protrudes from the surface of the first optical adjustment layer 12, so that a convex region is formed on the surface of the first optical adjustment layer 12, while a flat region 17 is formed in the region of the first optical adjustment layer 12 where the particle 15 is not provided. Since the first transparent conductive layer 13 and the first metal layer 14 are sequentially stacked on the surface of the first optical adjustment layer 12, the surface shapes of the two are the same as the surface shape of the first optical adjustment layer 12. Therefore, a plurality of protrusions 16 will be formed in the region of the first metal layer 14 corresponding to the particle 15.

[0065] Similarly, when the second optical adjustment layer 22 contains the particles 15, a plurality of protrusions 16 can also be formed on the surface of the second metal layer 24.

[0066] When manufacturing the long strip-shaped transparent conductive film 10 by using the roll to roll process, since the particle 15 makes a plurality of protrusions 16 formed on the surface of the first metal layer 14 and / or the second metal layer 24. Therefore, when the transparent conductive film 10 is curled, the plurality of protrusions 16 can form point contacts between adjacent two metal layers, thereby preventing them from sticking and pressing against each other.

[0067] Moreover, since the outer surface of the particle 15 is formed with a surface concavo-convex structure, the outer surface of the particle 15 is a non-smooth curved surface. On the one hand, the roughness of the outer surface of the particle 15 increases. On the other hand, the contact area between the particle 15 and the optical adjustment layer increases. And the adhesion of the particle 15 is positively correlated with the roughness and the contact area. Therefore, the adhesion of the particle 15 in the optical adjustment layer increases, thereby effectively preventing the particle 15 from falling off.

[0068] Furthermore, compared with the traditional conductive film, the transparent conductive film 10 does not include a hard coat, and the particles 15 are located in the optical adjustment layer (at least one of the first optical adjustment layer 12 and the second optical adjustment layer 22). On the one hand, after omitting the hard coat, the film layer structure can be reduced, thereby reducing the light shielding. Moreover, the structure is simplified, which is beneficial to simplifying the process and reducing the cost. On the other hand, the optical adjustment layer itself has the function of adjusting the optical effect. Therefore, when the light passes through the particles 15 located in the optical adjustment layer, the refraction and scattering phenomena are enhanced.

[0069] In the traditional conductive film, the hard coat releases water vapor or organic solvents during the manufacturing process, resulting in poor crystallinity of the conductive layer (for example, the ITO layer) and uneven sheet resistance. However, since the transparent conductive film 10 of the present invention does not include a hard coat, the released water vapor or organic solvents are reduced, thereby improving the crystallinity of the conductive layer, and further making its sheet resistance more uniform. In addition, the brittleness of the transparent conductive film 10 is reduced, greatly improving the performance of the conductive film slitting and winding processes, and thus effectively avoiding cracking during the punching of large sheets of materials.

[0070] Specifically, in this embodiment, the substrate 11 is a cyclic olefin polymer film.

[0071] Cyclic olefin polymer (COP) is a new type of amorphous polymer material, and has high hardness and excellent light transmittance, but its brittleness is very high. Therefore, hard coats are often coated on its two surfaces to improve it, but this inertial approach ignores the side effects of the hard coat on subsequent crystallization. In this embodiment, since the particles 15 are added to the optical adjustment layer, its strength and toughness are increased, so it can protect the substrate 11. Therefore, even if the hard coat is omitted, the COP material can be used to make the substrate 11, so that the substrate 11 has the characteristics of high hardness and good light transmittance.

[0072] In this embodiment, both the first optical adjustment layer 12 and the second optical adjustment layer 22 contain the particles 15, so that a plurality of protrusions 16 are formed on the surfaces of the first metal layer 14 and the second metal layer 24.

[0073] That is to say, a plurality of protrusions 16 are formed on both sides of the obtained transparent conductive film 10. Therefore, when the transparent conductive film 10 is curled, the number of point contact positions between adjacent metal layers increases, so the anti-adhesion and anti-pressure bonding effects are better.

[0074] Please refer to Figure 4 , in another embodiment, either the first optical adjustment layer 12 or the second optical adjustment layer 22 contains particles 15, so that a plurality of protrusions 16 are formed on the surface of the first metal layer 14 or the second metal layer 24.

[0075] That is to say, a plurality of protrusions 16 are formed only on one side of the obtained transparent conductive film 10. Therefore, while playing the role of anti-adhesion and anti-pressure bonding, it can also avoid the shadows of the two layers of particles 15 from overlapping each other, so as to reduce the haze and further improve the optical effect of the transparent conductive film 10.

[0076] In this embodiment, there is a gap between the plurality of particles 15 and the surface of the substrate 11, and the particle size of the particles 15 is smaller than the thickness of the flat area 17. The flat area 17 is an area where the first optical adjustment 12 or the second optical adjustment layer 22 is not provided with particles 15.

[0077] In the existing conductive film with anti-adhesion function, the particle size of the particles must be larger than the thickness of the hard coating to form protrusions on the surface of the metal layer. Therefore, the particle size of the particles is limited by the thickness of the hard coating and cannot be further reduced. However, the larger the particle size, the greater the haze value and the lower the light transmittance of the conductive film, which in turn affects the optical effect of the conductive film.

[0078] In this embodiment, since the particle size of the particles 15 is smaller than the thickness of the optical adjustment layer. Therefore, the particle size of the particles 15 is not limited by the thickness of the optical adjustment layer, and the particle size of the particles 15 can be further reduced compared to the particle size of the particles in the existing anti-adhesion conductive film, so as to further reduce the haze value and improve the light transmittance, and finally improve the optical effect.

[0079] Specifically, in this embodiment, the proportion of the particles 15 located in the first optical adjustment layer 12 or the second optical adjustment layer 22 in the particles 15 is less than one-half.

[0080] As mentioned above, since the adhesion of the particles 15 in the optical adjustment layer increases. Therefore, even if the part of the particles 15 embedded in the optical adjustment layer is less than one-half of the whole particles 15, the stability of the adhesion of the particles 15 will not be weakened. Further, the less the part of the particles 15 embedded in the optical adjustment layer, the smaller the particle size of the particles 15 at the same protrusion height. The smaller the particle size, the weaker the shielding effect of the particles 15 on light. Therefore, the optical effect of the transparent conductive film 10 can be further improved.

[0081] In this embodiment, the thickness of the flat area 17 is 45 to 145 nanometers.

[0082] As described above, the flat area 17 is the area where the first optical adjustment layer 12 or the second optical adjustment layer 22 is not provided with the particles 15. Within this range, the optical adjustment effect of the optical adjustment layer is the best, and the optical effect of the transparent conductive film 10 can be in the best state.

[0083] In one embodiment, the particles 15 are made of the same material as the first optical adjustment layer 12 and the second optical adjustment layer 22.

[0084] Since the particles 15 are made of the same material as the optical adjustment layer, the optical parameters of the particles 15 and the optical adjustment layer are also the same. Therefore, at the connection interface between the particles 15 and the optical adjustment layer, the influence on the light propagation is small, and the particles 15 and the optical adjustment layer are closer to being a whole. When light passes through the optical adjustment layer containing the particles 15, the distortion of its propagation route is small. Therefore, while achieving the purposes of anti-adhesion and anti-compression bonding, the transparent conductive film 10 can also avoid adverse effects on its optical performance.

[0085] Moreover, due to the same material, the adhesion of the particles 15 in the optical adjustment layer can be further enhanced.

[0086] In order to achieve better anti-adhesion and anti-compression bonding effects, there are corresponding requirements for the density of the protrusions 16.

[0087] In this embodiment, the distribution density of the protrusions 16 is 100 to 3000 pieces / mm 2 . Further, the height of the plurality of protrusions 16 is 0.1 to 0.5 μm.

[0088] When the distribution density of the protrusions 16 is too large, it will cause the haze value of the transparent conductive film 10 to be too large and the light transmittance to decrease, which will seriously affect the appearance and optical effect of the transparent conductive film 10. If the distribution density of the protrusions 16 is too small, the anti-adhesion effect is limited. Within the above density range, the transparent conductive film 10 can better balance the anti-adhesion and optical effects.

[0089] The height of the protrusion 16 refers to the height by which the protrusion 16 protrudes from the surface of the first metal layer 14 and / or the second metal layer 24. Since the size of the particles 15 is small, it is difficult to precisely control the height of each protrusion 16. Therefore, it is sufficient to control the height of the protrusion 16 within the above height range. It should be noted that in actual production, due to the difficulty in accurately controlling each particle 15, it is inevitable that there will be a very small number of protrusions 16 formed by the particles 15 whose height is outside the above range. However, the influence caused by this part of the protrusions 16 can be ignored. Moreover, the above height can also refer to the arithmetic mean of the heights of a certain number of protrusions 16 within a preset range.

[0090] Generally, the higher the height of the protrusion 16, the better the anti-sticking effect. However, as the height increases, the size of the particles 15 needs to increase accordingly, resulting in an increase in the haze value of the transparent conductive film 10, and after reaching a certain level, 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.

[0091] In the above transparent conductive film 10, 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, so that the transparent conductive film 10 has an anti-sticking function. Further, the outer surface of the particles 15 is formed with a surface uneven structure, so that the outer surface of the particles 15 is a non-smooth curved surface. On the one hand, the roughness of the outer surface of the particles 15 increases. On the other hand, the contact area between the particles 15 and the optical adjustment layer increases. And the adhesion of the particles 15 is positively correlated with the roughness and the contact area. Therefore, the adhesion of the particles 15 in the optical adjustment layer increases, so as to effectively prevent the particles 15 from falling off.

[0092] In addition, the present invention also provides a touch screen. Please refer to Figure 5 together. The touch screen 200 in the preferred embodiment of the present invention is made of the transparent conductive film 10 in the above embodiment. Among them:

[0093] 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.

[0094] The touch area 210 includes a first electrode 211 and a second electrode 212. Among them, the first electrode 211 is formed by etching the first transparent conductive layer 13; the second electrode 212 is formed by etching the second transparent conductive layer 23. The first electrode 211 and the second electrode 212 are etched into electrode patterns. Specifically, the electrode patterns are generally strip-shaped and vertically intersect to form a grid shape, and the opposite first electrode 211 and second electrode 212 form two poles of a capacitive structure.

[0095] The lead area 220 includes a first lead 221 and a second lead 222. The first lead 221 is formed by etching the first metal layer 14 and the first transparent conductive layer 13 located in the lead area 220; the second lead 222 is formed by etching the second metal layer 24 and the second transparent conductive layer 23 located in the lead area 220. The first lead 221 and the second lead 222 are of a double-layer structure, so as to realize electrical connection with the first electrode 211 and the second electrode 212.

[0096] 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, since there is no need for screen printing, the width of the electrode leads formed directly by the yellow light process can be further reduced, so the touch screen has a narrow border.

[0097] Please also refer to Figure 6 , the present invention also provides a method for manufacturing a touch screen, and this method includes steps S310 to S330:

[0098] Step S310: Provide a transparent conductive film.

[0099] Specifically, the transparent conductive film is the transparent conductive film 100 in the above embodiment, which includes a first transparent conductive layer 13 and a first metal layer 14 arranged in a stacked manner, and a second transparent conductive layer 23 and a second metal layer 24 arranged in a stacked manner.

[0100] Step S320: Etch 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 area, and form a metal lead pattern located in the lead area

[0101] Specifically, a metal lead pattern can be formed on the surface of the metal layer through a single yellow light process. Among them, 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 below it are partially exposed.

[0102] Step S330: Etch the first transparent conductive layer 13 and the second transparent conductive layer 23 to form a first electrode 211 and a second electrode 212 in the touch area, and form a transparent lead pattern in the lead area. The metal lead pattern and the transparent lead pattern together constitute the electrode lead.

[0103] Specifically, another yellow light process is used to etch the exposed portions of the first transparent conductive layer 13 and the second transparent conductive layer 24 to form electrode patterns, thereby obtaining the first electrode 211 and the second electrode 212. At the same time, the first metal layer 14 and the second metal layer 24 in the form of metal lead patterns are respectively superimposed on the first transparent conductive layer 13 and the second transparent conductive layer 23 in the lead area, thereby forming the first lead 221 and the second lead 222 with a double-layer structure. The first lead 221 and the second lead 222 are respectively electrically connected to the first electrode 211 and the second electrode 212.

[0104] When preparing the touch screen by the above method, directly etching the first metal layer 14, the second metal layer 24, the first transparent conductive layer 13 and the second transparent conductive layer 23 can obtain 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. Therefore, there is no need to use the screen printing method to form the leads, effectively simplifying the process and improving the processing efficiency. Moreover, the touch screen prepared by the above method has a narrow border.

[0105] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0106] The above-described embodiments merely represent several implementation manners of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A transparent conductive film, comprising: a substrate including a first surface and a second surface which are oppositely arranged; a first optical adjustment layer, a first transparent conductive layer and a first metal layer formed in sequence on the first surface; a second optical adjustment layer, a second transparent conductive layer and a second metal layer formed in sequence on the second surface; characterized in that the first optical adjustment layer and / or the second optical adjustment 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; the particles are made of the same material as the first optical adjustment layer and the second optical adjustment layer; wherein, a plurality of strip-shaped grooves are formed on the outer surface of the particles to form a surface uneven structure, so that the outer surface of the particles is a non-smooth curved surface.

2. The transparent conductive film according to claim 1, wherein There is a gap between the plurality of particles and the surface of the substrate, and the particle size of the particles is smaller than the thickness of the flat area, and the flat area is an area where the first optical adjustment layer or the second optical adjustment layer is not provided with the particles.

3. The transparent conductive thin film according to claim 2, wherein The proportion of the particles located in the first optical adjustment layer or the second optical adjustment layer in the particles is less than one-half.

4. The transparent conductive film according to claim 2, wherein The thickness of the flat area is 45 to 145 nanometers.

5. The transparent conductive film according to claim 1, characterized in that, The substrate is a cycloolefin polymer film.

6. The transparent conductive film according to claim 1, wherein The distribution density of the protrusions is 100 to 3000 per mm 2 , and the height of the multiple protrusions is 0.1 to 0.5 μm.

7. A touch screen, characterized in that, The touch screen is made of the transparent conductive film according to any one of claims 1 to 6 above. The touch screen includes a touch area and a lead area. The first metal layer and the second metal layer are located in the lead area. The touch area includes a first electrode formed by etching the first transparent conductive layer and a second electrode formed by etching the second transparent conductive layer. The lead area includes a first lead formed by etching the first metal layer and the first transparent conductive layer located in the lead area, and a second lead formed by etching the second metal layer and the second transparent conductive layer located in the lead area.

8. A method for preparing a touch screen, characterized in that, Including steps: Providing a transparent conductive film according to any one of claims 1 to 6 above; 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 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 form a transparent lead pattern in the lead area, and the metal lead pattern and the transparent lead pattern together constitute an electrode lead.

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