TWI403928B - Method for making touch panel - Google Patents

Abstract

The present invention relates to a method for making touch panel. The method includes the following steps: providing a first substrate; forming a carbon nanotube composite layer on a surface of the first substrate, to achieve a first electrode plate; repeating the former steps and forming a second electrode plate; encapsulating the first electrode plate and the second electrode, to achieve the touch panel.

Description

Touch screen preparation method

The invention relates to a touch screen, in particular to a carbon nanotube-based touch screen.

In recent years, with the development of high performance and diversification of various electronic devices such as mobile phones and touch navigation systems, electronic devices in which a translucent touch panel is mounted on the front surface of a display element such as a liquid crystal are gradually increasing. The user of such an electronic device operates by pressing the touch panel with a finger or a pen while visually checking the display content of the display element located on the back surface of the touch panel through the touch panel. Thereby, various functions of the electronic device can be operated.

According to the working principle of the touch screen and the transmission medium, the previous touch screens are generally divided into four types, namely, resistive, capacitive inductive, infrared, and surface acoustic wave. Among them, the resistive touch screen is the most widely used, please refer to the document "Production of Transparent Conductive Films with Inserted SiO ₂ Anchor Layer, and Application to a Resistive Touch Panel" Kazuhiro Noda, Kohtaro Tanimura. Electronics and Communications in Japan, Part 2, Vol. , P39-45 (2001).

The prior resistive touch screen generally comprises an upper substrate, the upper surface of which is formed with an upper transparent conductive layer; the lower substrate, the upper surface of which is formed with a transparent conductive layer; and a plurality of dot spacers (Dot Spacer ) is disposed between the upper transparent conductive layer and the lower transparent conductive layer . The upper transparent conductive layer and the lower transparent conductive layer generally adopt an indium tin oxide (ITO) layer (hereinafter referred to as an ITO layer) having conductive properties. When the upper substrate is pressed with a finger or a pen, the upper substrate is twisted such that the upper transparent conductive layer and the lower transparent conductive layer at the pressing portion are in contact with each other. The voltage is sequentially applied to the upper transparent conductive layer and the lower transparent conductive layer through the external electronic circuit, and the touch screen controller measures the voltage change on the first conductive layer and the voltage change on the second conductive layer, respectively, and performs accurate calculation. Converted to contact coordinates. The touch screen controller passes the digitized contact coordinates to the central processor. The central processor issues corresponding commands according to the contact coordinates, initiates various function switching of the electronic device, and controls the display of the display components through the display controller.

The preparation method of the prior resistive touch screen usually adopts an ion beam sputtering or evaporation process to deposit an ITO layer on the upper and lower substrates as a transparent conductive layer. In the process of preparation, a high vacuum environment is required and heating is required to 200~. At 300 ° C, the preparation of the touch screen using the ITO layer as the transparent conductive layer is relatively high. In addition, the ITO layer as a transparent conductive layer has disadvantages such as insufficient mechanical properties, difficulty in bending, and uneven distribution of resistance. In addition, ITO will gradually decrease in transparency in humid air. As a result, the prior resistive touch screen and the display device have disadvantages such as insufficient durability, low sensitivity, linearity, and poor accuracy.

In view of this, it is necessary to provide a touch screen with good durability, high sensitivity, linearity and accuracy.

A touch screen includes: a first electrode plate, the first electrode plate includes a first substrate and a first conductive layer, wherein the first conductive layer is disposed at the first a lower surface of the substrate; and a second electrode plate spaced apart from the first electrode plate, the second electrode plate comprising a second substrate and a second conductive layer, the second conductive layer being disposed An upper surface of the second substrate; wherein the first conductive layer and the second conductive layer each comprise a carbon nanotube composite layer, the carbon nanotube composite layer comprises a carbon nanotube layer and uniformly infiltrated a polymer material in the carbon nanotube layer.

Compared with the prior art, the touch screen using the carbon nanotube composite material layer as the transparent conductive layer provided by the embodiments of the present technical solution has the following advantages: First, the carbon nanotube has excellent mechanical properties, and the carbon nanotube layer is disposed. The composite structure formed by the polymer material makes the transparent conductive layer have good toughness and mechanical strength, so that the durability of the touch screen can be correspondingly improved; secondly, because the carbon nanotube has excellent electrical conductivity, the above-mentioned nanometer The carbon tube layer comprises a plurality of uniformly distributed carbon nanotubes. Therefore, the above-mentioned carbon nanotube composite material layer is used as a transparent conductive layer, so that the transparent conductive layer has a uniform resistance distribution, thereby improving the touch screen and using the touch screen. The resolution and accuracy of the display device. Thirdly, since the polymer material layer at least partially penetrates into the carbon nanotube layer, the combination of the carbon nanotube layer and the substrate is firm, which increases the service life of the touch screen.

The touch screen provided by the embodiment of the present technical solution and a method for fabricating the same are described in detail below with reference to the accompanying drawings.

Referring to FIG. 1 and FIG. 2 , the embodiment of the present disclosure provides a touch screen 10 . The touch screen 10 includes a first electrode plate 12 , a second electrode plate 14 , and the first electrode plate 12 and the second electrode plate 14 . A plurality of transparent dot spacers 16 therebetween.

The first electrode plate 12 includes a first substrate 120, a first conductive layer 122 and two first electrodes 124. The first substrate 120 is a planar structure, and the first conductive layer 122 and the two first electrodes 124 are disposed on the lower surface of the first substrate 120. The two first electrodes 124 are respectively disposed at both ends of the first conductive layer 122 in the first direction and are electrically connected to the first conductive layer 122. The second electrode plate 14 includes a second substrate 140, a second conductive layer 142 and two second electrodes 144. The second substrate 140 is a planar structure, and the second conductive layer 142 and the two second electrodes 144 are both disposed on the upper surface of the second substrate 140. The two second electrodes 144 are respectively disposed at both ends of the second conductive layer 142 in the second direction and are electrically connected to the second conductive layer 142. The first direction is perpendicular to the second direction, that is, the two first electrodes 124 are orthogonal to the two second electrodes 144.

The first conductive layer 122 and the second conductive layer 142 each adopt a carbon nanotube composite layer. Referring to FIG. 3, the carbon nanotube composite layer includes a carbon nanotube layer and uniformly infiltrates into the nanometer. a polymer material in the carbon tube layer. The thickness of the carbon nanotube composite layer is not limited, and is preferably from 0.5 nm to 1 mm. The polymer material is a transparent polymer material including polystyrene, polyethylene, polycarbonate, polymethyl methacrylate (PMMA), polycarbonate (PC), and ethylene terephthalate. (PET), phenylcyclobutene (BCB), polycycloolefin, and the like. In this embodiment, the polymer material is PMMA. The polymer material in the carbon nanotube composite layer enables the nano carbon tube layer to be firmly bonded to the flexible substrate. Meanwhile, as shown in Fig. 4, the carbon nanotube layer is formed by infiltration of the polymer material into the carbon nanotube layer. The short circuit between the carbon nanotubes in the middle is eliminated, so that the resistance of the carbon nanotube layer is in a good linear relationship.

The carbon nanotube layer is a layered structure having a uniform thickness formed of ordered or disordered carbon nanotubes which are uniformly distributed and in contact with each other in the carbon nanotube layer. The carbon nanotube layer has a thickness of from 0.5 nm to 100 μm. Specifically, the carbon nanotube layer comprises at least one layer of carbon nanotube film comprising a disordered carbon nanotube film or an ordered carbon nanotube film. In the disordered carbon nanotube film, the carbon nanotubes are disordered or isotropic. In the ordered carbon nanotube film, the carbon nanotubes are arranged in a preferred orientation along the same direction or in a preferred orientation in different directions. The carbon nanotubes in the carbon nanotube layer include one or more of a single-walled carbon nanotube, a double-walled carbon nanotube, and a multi-walled carbon nanotube. Among them, the diameter of the single-walled carbon nanotubes is 0.5 nm to 50 nm, the diameter of the double-walled carbon nanotubes is 1.0 nm to 50 nm, and the diameter of the multi-walled carbon nanotubes is 1.5 nm to 50. Nano.

Preferably, the ordered carbon nanotube film comprises at least one layer drawn directly from the carbon nanotube array to obtain a carbon nanotube film structure. Specifically, referring to FIG. 5, the carbon nanotube film structure further includes a plurality of carbon nanotubes connected end to end and arranged along the stretching direction of the carbon nanotube film. The carbon nanotubes are evenly distributed and parallel to the surface of the nanotube structure. The carbon nanotubes in the structure of the carbon nanotube film are connected by van der Waals force. On the one hand, the carbon nanotubes connected end to end are connected end to end by van der Waals force; on the other hand, the parallel nano carbon The pipe section is also combined by Van der Valli. A uniform gap is formed between the carbon nanotubes in the carbon nanotube film structure, and the gap has a diameter of 1 nm to 10 μm. The polymer material is uniformly filled in the gap between the carbon nanotubes. When the ordered carbon nanotube film comprises a plurality of carbon nanotube film knots In the structure, the carbon nanotube film structure is overlapped, and the arrangement direction of the carbon nanotubes in the adjacent two layers of carbon nanotube film structure forms an angle α, wherein α is greater than or equal to zero degrees and less than or equal to 90 degrees ( 0 α 90°). The length and width of the carbon nanotube thin film structure are not limited, and can be prepared according to actual needs, and the thickness of the nano carbon tube film structure is 0.5 nm to 100 μm. In this embodiment, the first conductive layer 122 and the second conductive layer 142 both adopt a single-layer carbon nanotube film structure and a carbon nanotube composite layer formed by PAMM, and the PAMM is filled in the carbon nanotube film. In the gap between the carbon nanotubes in the structure, the carbon nanotubes in the first conductive layer 122 are aligned along the first direction, and the carbon nanotubes in the second conductive layer 142 are aligned along the second direction.

The first substrate 120 and the second substrate 140 of the touch screen 10 are both transparent films or sheets. The first base body 120 has a certain degree of softness and can be formed of a flexible material such as plastic or resin. The material of the second substrate 140 may be a hard material such as glass, quartz or diamond. When used in the flexible touch liquid crystal display panel 300, the material of the second substrate 140 may also be a flexible material such as plastic or resin. Specifically, the materials used for the first substrate 120 and the second substrate 140 may be polyesters such as polycarbonate (PC), polymethyl methacrylate (PMMA), and polyethylene terephthalate (PET). Materials, and materials such as polyether oxime (PES), cellulose ester, polyvinyl chloride (PVC), benzocyclobutene (BCB) and acrylic resin. The first base body 120 and the second base body 140 have a thickness of 0.1 mm to 1 cm. In this embodiment, the first base body 120 and the second base body 140 are made of PET and have a thickness of 2 mm. It can be understood that the materials forming the first base body 120 and the second base body 140 are not limited to the materials listed above, as long as the first base body 120 and the second base body 140 can be enabled. It acts as a support and has a good transparency, and at least the material forming the first substrate 120 has a certain flexibility, which is within the scope of the present invention.

The first electrode 124 and the second electrode 144 of the touch screen 10 are formed of a conductive material, and may be selected as a metal material, a conductive polymer material or a carbon nanotube layer. The material of the metal layer may be selected from a metal having good conductivity such as gold, silver or copper. The material of the conductive polymer layer may be selected from the group consisting of polyacetylene, polyparaphenylene, polyaniline, polyimibe, polypyrrole, polythiophene and the like. Preferably, the carbon nanotube layer comprises at least one carbon nanotube film structure. In this embodiment, the first electrode 124 and the second electrode 144 are conductive silver paste layers.

Further, in the touch screen 10, an insulating layer 18 is disposed on the periphery of the surface of the second electrode plate 14 adjacent to the first electrode plate 12. The first electrode plate 12 is disposed on the insulating layer 18, and the first conductive layer 122 of the first electrode plate 12 is disposed opposite to the second conductive layer 142 of the second electrode plate 14. The plurality of dot spacers 16 are disposed on the second conductive layer 142 of the second electrode plate 14, and the plurality of dot spacers 16 are spaced apart from each other. The distance between the first electrode plate 12 and the second electrode plate 14 is 2 to 10 μm. The insulating layer 18 and the dot spacer 16 may be made of an insulating resin or other insulating material, and the dot spacer 16 should be made of a transparent material. Providing the insulating layer 18 and the dot spacers 16 may electrically insulate the first electrode plate 14 from the second electrode plate 12. It can be understood that when the touch screen 10 is small in size, the dot spacer 16 is an optional structure, and it is only necessary to ensure that the first electrode plate 14 is electrically insulated from the second electrode plate 12.

In use, the first electrode plate 12 and the second electrode plate 14 respectively pass a voltage of 5V. When the user presses the first electrode plate 12 of the touch screen 10 by a finger or a pen, the first base 120 in the first electrode plate 12 is bent, so that the first conductive layer 122 at the pressing portion and the second conductive layer 122 are pressed. The electrode layer 142 forms a contact point at which a conduction is formed. Since the pressing points are different, the formed contact points are different, and each contact point corresponds to a different electrical signal, thereby enabling signal transmission.

The touch screen using the carbon nanotube composite material layer as the transparent conductive layer provided by the embodiment of the present technical solution has the following advantages: First, the carbon nanotube has excellent mechanical properties, and the carbon nanotube layer is formed by the polymer material. The composite structure makes the transparent conductive layer have good toughness and mechanical strength, so that the durability of the touch screen can be correspondingly improved; secondly, since the carbon nanotube has excellent electrical conductivity, the above-mentioned carbon nanotube layer includes a plurality of Uniformly distributed carbon nanotubes, therefore, using the above-mentioned carbon nanotube composite material layer as a transparent conductive layer, the transparent conductive layer can have a uniform resistance distribution, thereby improving the resolution of the touch screen and the display device using the touch screen. Accuracy. Thirdly, since the polymer material layer at least partially penetrates into the carbon nanotube layer, the combination of the carbon nanotube layer and the substrate is firm, which increases the service life of the touch screen.

Referring to FIG. 6 , an embodiment of the present technical solution provides a method for preparing the touch screen 10 described above, which specifically includes the following steps:

Step 1: Provide a first substrate.

The first substrate is a flexible planar structure having a thickness of 0.1 mm to 1 cm. The first substrate is formed of a flexible material such as plastic or resin. Specifically, the material of the first substrate may be polycarbonate (PC), polymethyl methacrylate Polyester materials such as ester (PMMA), polyethylene terephthalate (PET), and polyether oxime (PES), polyamidamine (PI), cellulose ester, benzocyclobutene (BCB) , polyvinyl chloride (PVC) and acrylic materials. It is to be understood that the material forming the first substrate is not limited to the materials listed above, as long as the flexible substrate has a certain flexibility and a good transparency.

In the embodiment of the technical solution, the first substrate is a polyethylene terephthalate (PET) film (hereinafter referred to as a PET film). The PET film has a thickness of 2 mm, a width of 20 cm, and a length of 30 cm.

Step 2: forming a carbon nanotube composite layer on the surface of the first substrate to obtain a first electrode plate.

The method for forming a carbon nanotube composite layer on the surface of the first substrate comprises the following steps:

(1) coating a surface of the first substrate to form a polymer material solution.

Use a brush or other tool to take a certain amount of polymer material solution, apply it evenly on the surface of the flexible substrate or immerse the surface of the flexible substrate in the polymer material solution to directly take a certain amount of polymer material solution to form a high Molecular material solution layer. It can be understood that the manner of coating the polymer material solution on the surface of the flexible substrate is not limited as long as a uniform polymer material solution can be formed on the surface of the flexible substrate.

The polymer material solution comprises a solution formed by dissolving a polymer material in an organic solvent, which has a certain viscosity. Preferably, the viscosity of the polymer material solution is greater than 1 Pa.s. The polymer material is solid at normal temperature State, and has a certain degree of transparency. The organic solvent includes ethanol, methanol, acetone, dichloroethane or chloroform. The polymer material includes polystyrene, polyethylene, polycarbonate, polymethyl methacrylate (PMMA), polycarbonate (PC), ethylene terephthalate (PET), styrene ring Alkene (BCB), polycycloolefin, and the like. In this embodiment, the polymer material is PMMA, and the polymer material solution is a solution in which PMMA is dissolved in ethanol.

(2) Preparing a carbon nanotube film.

The carbon nanotube film is an ordered carbon nanotube film or a disordered carbon nanotube film, and the carbon nanotube film can be pulled by a rolling method, a flocculation method, or directly from a carbon nanotube array Get it. Preferably, in this embodiment, the carbon nanotube film is a carbon nanotube film structure obtained directly from the carbon nanotube array. The preparation method of the carbon nanotube film structure comprises the following steps:

First, a carbon nanotube array is provided, preferably the array is a super-sequential carbon nanotube array.

The carbon nanotube array provided by the embodiments of the present technical solution is one or more of a single-walled carbon nanotube array, a double-walled carbon nanotube array, and a multi-walled carbon nanotube array. In this embodiment, the method for preparing the super-sequential carbon nanotube array adopts a chemical vapor deposition method, and the specific steps thereof include: (a) providing a flat substrate, the substrate may be selected from a P-type or N-type germanium substrate, or The germanium substrate formed with the oxide layer is selected, and the present embodiment preferably uses a 4-inch germanium substrate; (b) a catalyst layer is uniformly formed on the surface of the substrate, and the catalyst layer material may be iron (Fe), cobalt (Co) or nickel. (Ni) or any combination thereof (c) annealing the substrate on which the catalyst layer is formed in air at 700 ° C to 900 ° C for about 30 minutes to 90 minutes; (d) placing the treated substrate in a reaction furnace for protection It is heated to 500 ° C ~ 740 ° C in a gaseous environment, and then reacted with a carbon source gas for about 5 to 30 minutes to grow a super-aligned carbon nanotube array with a height of 50 μm to 5 mm. The super-sequential carbon nanotube array is a plurality of pure carbon nanotube arrays formed of carbon nanotubes that are parallel to each other and perpendicular to the substrate. The super-sequential carbon nanotube array contains substantially no impurities such as amorphous carbon or residual catalyst metal particles, etc., by controlling the growth conditions described above. The carbon nanotubes in the array of carbon nanotubes are in close contact with each other to form an array by van der Waals force. The carbon nanotube array is substantially the same area as the above substrate.

In this embodiment, the carbon source gas may be a chemically active hydrocarbon such as acetylene, ethylene or methane. The preferred carbon source gas in this embodiment is acetylene; the shielding gas is nitrogen or an inert gas, and the preferred shielding gas in this embodiment. It is argon.

It can be understood that the carbon nanotube array provided by the embodiment is not limited to the above preparation method. It can also be a graphite electrode constant current arc discharge deposition method, a laser evaporation deposition method, or the like.

Next, a carbon nanotube film structure was obtained by pulling from a carbon nanotube array using a stretching tool. Specifically, the method comprises the following steps: (a) selecting a portion of the carbon nanotubes from the carbon nanotube array; in this embodiment, it is preferred to contact the carbon nanotube array with a tape having a certain width to select a portion of the carbon nanotubes; b) stretching the portion of the carbon nanotubes at a rate substantially perpendicular to the growth direction of the nanotube array to form a continuous carbon nanotube film structure.

During the above stretching process, the portion of the carbon nanotubes gradually disengages from the substrate in the stretching direction under the action of the tensile force, and the carbon nanotubes in the selected portion of the carbon nanotubes are respectively associated with the van der Waals force. The other carbon nanotubes in the carbon nanotube array are continuously pulled out end to end to form a carbon nanotube film structure. The width and thickness of the carbon nanotube film structure are related to the width and height of the carbon nanotube array. In this embodiment, the nano carbon tube film structure has a width of 20 cm and a thickness of 0.5 nm to 100. Micron.

(3) The above-mentioned carbon nanotube film is treated by laser treatment.

Due to the van der Waals case between the carbon nanotubes in the carbon nanotube film, some of the carbon nanotubes in the carbon nanotube film are easily aggregated to form a carbon nanotube bundle, and the diameter of the carbon nanotube bundle is larger. , affecting the conductivity of the carbon nanotube film. In order to improve the light transmittance of the carbon nanotube film, the carbon nanotube film is irradiated with a laser having a power density of more than 0.1×10 ⁴ watts/m 2 to remove the poorly transmissive carbon nanotube bundle in the carbon nanotube film. . The step of treating the carbon nanotube film by laser can be carried out in an oxygen-containing environment, preferably in an air environment.

The laser treatment of the above carbon nanotube film can be carried out by fixing the carbon nanotube film, and then moving the laser device to irradiate the carbon nanotube film or by fixing the laser device to move the carbon nanotube film to make the laser The method of irradiating the carbon nanotube film is achieved.

In the process of irradiating the carbon nanotube film by the above laser, since the carbon nanotube has good absorption characteristics for the laser, and the laser is a light with higher energy, it is absorbed by the carbon nanotube film. Heat, make nano The carbon nanotubes in the carbon tube film are heated. In the carbon nanotube film, in the carbon nanotube film, the larger diameter carbon nanotube bundle absorbs more heat, so the temperature of the carbon nanotube in the carbon nanotube bundle is higher, when the nanocarbon When the temperature of the tube is sufficiently high (generally greater than 600 ° C), the carbon nanotube bundle is burned by the laser. Please refer to Figures 7 and 8, relative to the carbon nanotube film before laser treatment. The light transmittance of the carbon nanotube film after laser treatment is remarkably improved, and the light transmittance is more than 70%.

It can be understood that the purpose of using the laser treatment of the carbon nanotube film structure is to further improve the transparency of the carbon nanotube film structure, so this step is an optional step.

(4) laying the at least one carbon nanotube film on the surface of the polymer material solution on the flexible substrate to form a carbon nanotube layer.

At least one layer of carbon nanotube film can be directly laid on the surface of the polymer material layer, and a plurality of carbon nanotube films can be laid in parallel or without overlapping. When the carbon nanotube film is a nano carbon tube film structure, when the carbon nanotube layer comprises at least two layers of carbon nanotube film structure, adjacent carbon nanotubes in the carbon nanotube layer are pulled The arrangement direction of the carbon nanotubes in the film structure forms an angle α, where 0° α 90°. In this embodiment, the carbon nanotube layer comprises a layer of carbon nanotube film structure.

After the carbon nanotube layer is formed on the polymer material layer, a sandwich structure including the first substrate, the polymer material layer, and the carbon nanotube layer in this order is formed.

(5) infiltrating the polymer material solution into the carbon nanotube layer to solidify the polymer material and the carbon nanotube layer to form a carbon nanotube composite layer .

Applying a certain pressure to the carbon nanotube layer by external force, such as using a wind knife to blow the carbon nanotube layer with a wind of 10 m-20 m/s, and then laminating the polymer material layer with the carbon nanotube to make the polymer material The layer penetrates into the carbon nanotube layer. The method of infiltrating the polymer material solution into the carbon nanotube layer is not limited to the above-described method using wind blowing, as long as the polymer material solution can be infiltrated into the carbon nanotube layer. After the polymer material penetrates into the carbon nanotube layer, the above structure is heated to a certain temperature to volatilize the solvent in the polymer material solution, and the polymer material is combined with the carbon nanotube layer and solidified to form on the surface of the flexible substrate. A carbon nanotube composite layer. The method for heating the polymer material solution and the carbon nanotube layer may be that the above structure is directly placed in a furnace and heated to a certain temperature, or ultraviolet curing is used, that is, the polymer material solution is heated by ultraviolet light of a certain energy. And a composite structure composed of carbon nanotube layers to reach a certain temperature. The temperature is related to the solvent in the polymer material solution, and the temperature is higher than the volatilization temperature of the flux. In the present embodiment, the temperature is 100 °C.

The polymer material in the carbon nanotube composite layer enables the nano carbon tube layer to be firmly bonded to the flexible substrate, and at the same time, the nano carbon in the carbon nanotube layer is formed by the penetration of the polymer material into the carbon nanotube layer. The short circuit between the tubes is eliminated, so that the resistance of the carbon nanotube layer is in a good linear relationship.

It can be understood that, in the method for preparing the first motor board, after forming the carbon nanotube composite material layer, further comprising forming a surface or a flexible substrate of the two first electrodes on the carbon nanotube composite layer at intervals Steps at both ends.

The material of the two electrodes is a metal, a carbon nanotube film, a conductive silver paste layer or other conductive material. In the embodiment of the technical solution, the two electrodes are conductive silver paste layers. The method of forming the two electrodes includes: screen printing, pad printing or spraying. In this embodiment, silver paste is respectively coated on the surface of the above-mentioned carbon nanotube composite material layer or both ends of the first substrate. Then, it is baked in an oven for 10 to 60 minutes to solidify the silver paste, and the baking temperature is 100 ° C to 120 ° C to obtain the two electrodes. The above preparation method is to ensure that the two electrodes are electrically connected to the carbon nanotube layer.

Step 3. Repeat the above steps to prepare a second electrode plate.

The second electrode plate includes a second substrate, a second carbon nanotube layer and two second electrodes.

Step 4: The first electrode plate and the second electrode plate are packaged to form a touch screen.

The method of packaging the first electrode plate and the second electrode plate includes the following steps:

(1) forming an insulating layer on a side of one side of the second electrode plate on which the carbon nanotube composite material layer is formed.

The insulating layer is formed by applying an insulating layer to the periphery of one side of the second electrode plate forming the carbon nanotube composite material layer. The material of the insulating layer includes a transparent resin or other insulating transparent material.

The insulating layer may be made of an insulating transparent resin or other insulating transparent material.

(2) covering the first electrode plate on the insulating layer, and making the first The carbon nanotube composite layer in the electrode plate and the carbon nanotube composite layer in the second electrode plate are oppositely disposed. The two first electrodes on the first electrode plate are disposed to intersect with the two second electrodes on the second electrode plate.

(3) sealing the periphery of the first electrode plate, the second electrode plate and the insulating layer with a sealant to form a touch screen. In this embodiment, the sealant is a 706B type yttrium sulfide rubber. The sealant is applied to the edges of the first electrode plate, the second electrode plate, and the insulating layer, and solidified after one day of standing.

Further, two electrodes of the first conductive layer and two of the second conductive layers are disposed to cross each other.

Furthermore, the preparation method may further include the step of forming a plurality of transparent dot spacers between the first electrode plate and the second electrode plate. The transparent dot spacer is formed by coating a slurry containing the plurality of transparent dot spacers on a region other than the insulating layer of the second electrode plate or the first electrode plate, and drying the solution. A transparent dot spacer is described. The insulating layer and the transparent dot spacer may be made of an insulating resin or other insulating material. Providing the insulating layer and the dot spacers electrically insulates the first electrode plate from the second electrode plate. It can be understood that when the size of the touch screen is small, the dot spacer is an optional structure, and it is only necessary to ensure that the first electrode plate is electrically insulated from the second electrode plate.

In the embodiment, in the method for preparing a touch screen, the preparation of the electrode plate can be realized by a continuous operation device.

Referring to FIG. 9, the continuous working device 200 described in this embodiment includes a first rotating shaft 202, a second rotating shaft 204, and a third rotating shaft 206. The container 208, a stage 210, a tube furnace 212, a traction device 214, a blowing device 216, a wiping device 230, a laser 234, and a power source (not shown). The first rotating shaft 202, the second rotating shaft 204 and a third rotating shaft 206 are spaced apart, and the axial directions thereof are in the same direction. The third rotating shaft 206 and the pulling device 214 are disposed at both ends of the axial direction of the tubular furnace. The blowing device 216 is disposed between the third rotating shaft 206 and the tube furnace 212. The wide mouth container 208 is disposed below the second rotating shaft 204, and the second rotating shaft 204 is partially located in the wide mouth container 208. The scraping device 230 is disposed adjacent to the second rotating shaft 204, and one end of the scraping device 230 is maintained at a fixed distance from the second rotating shaft 204. The first rotating shaft 202 is wound by a flexible substrate 218, and the wide-mouth container 208 contains a polymer material solution 220.

The method for preparing a first electrode plate or a second electrode plate by using the above continuous working device specifically includes the following steps:

(1) The flexible substrate 218 is sequentially connected to the third rotating shaft 204 and the third rotating shaft 206 and connected to the pulling device 214 through the tubular furnace to form a layer of polymer material 226 on the surface of the flexible substrate 218.

In this process, since the second rotating shaft 204 is partially located in the wide-mouth container 208, the polymer material solution 220 in the wide-mouth container 208 is adhered to the surface of the flexible substrate 218 to form a layer of the polymer material 226. The scraping device 230 and the second rotating shaft 204 maintain a certain distance. When the thickness of the polymer material layer 226 exceeds the distance, the scraping device 230 scrapes off. Therefore, the scraping device 230 can make the thickness of the polymer solution. Be sure and maintain uniformity.

(2) Fixing a super-sequential carbon nanotube array 222 on the stage 210, and pulling a continuous carbon nanotube from the super-aligned carbon nanotube array 222 The film structure 224 adheres one end of the carbon nanotube film structure 224 to the polymer material layer 226 on the surface of the flexible substrate 218. After the carbon nanotube film 224 is pulled out from the carbon nanotube array 222, when it is not in contact with the polymer material layer 226, the carbon nanotube film 224 can be irradiated with a laser emitted from the laser 234 to enhance the nanotube film 224. The transparency of the carbon nanotube film 224. The irradiation method and specific parameters are as described above.

(3) Turning on the power source so that the traction device 214 pulls the flexible substrate 218, the polymer material layer 226, and the carbon nanotube film 224 in a direction parallel to the axial direction of the tube furnace 212 at a certain speed, when the carbon nanotube film 224 When the lower portion of the blowing device 216 is reached, the wind blown by the blowing device 216 applies a certain pressure to the carbon nanotube film 224, so that the carbon nanotube film 224 is immersed in the polymer material layer 226, that is, the polymer material penetrates into the carbon nanotube. The film 224 is then passed through the tube furnace 212, and the high temperature inside the tube furnace 212 solidifies the polymer material infiltrated into the carbon nanotube film 224, and the carbon nanotube composite material layer 228 is formed on the surface of the flexible substrate 218.

(4) The flexible substrate 218 having the carbon nanotube composite material layer 228 formed is cut to form an electrode plate.

Further, two electrodes are disposed on the surface of the carbon nanotube composite material layer 228 to form a plurality of first electrode plates or second electrode plates.

By adopting the above steps, the polymer material solution is coated on the substrate to form a carbon nanotube composite material layer on the surface of the substrate, which can realize continuous production, improve production efficiency, save operation time, and further save cost.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above is only a preferred embodiment of the present invention. It is not possible to limit the scope of patent application in this case. Equivalent modifications or variations made by those skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims.

10‧‧‧ touch screen

12‧‧‧First electrode plate

14‧‧‧Second electrode plate

16‧‧‧ point spacers

18‧‧‧Insulation

120‧‧‧First substrate

122‧‧‧First conductive layer

124‧‧‧First electrode

140‧‧‧Second substrate

142‧‧‧Second conductive layer

144‧‧‧second electrode

200‧‧‧Continuous operating device

202‧‧‧First shaft

204‧‧‧second shaft

206‧‧‧ Third shaft

208‧‧‧ wide mouth container

210‧‧‧stage

212‧‧‧ tube furnace

214‧‧‧ traction device

216‧‧‧Blowing device

218‧‧‧Flexible substrate

220‧‧‧ polymer material solution

222‧‧‧Nano Carbon Tube Array

224‧‧‧Nano Carbon Tube Film

226‧‧‧ polymer material layer

228‧‧‧Nano Carbon Tube Composite Layer

230‧‧‧Scratch device

232‧‧‧Laser

FIG. 1 is a schematic perspective structural view of a touch screen provided by an embodiment of the present technical solution.

FIG. 2 is a schematic side view showing the structure of a touch screen provided by an embodiment of the present technical solution.

FIG. 3 is a scanning electron micrograph of a carbon nanotube composite layer provided by an embodiment of the present technical solution.

4 is a resistance linear diagram of a carbon nanotube composite layer provided by an embodiment of the present technical solution.

FIG. 5 is a scanning electron micrograph of a carbon nanotube film provided by an embodiment of the present technical solution.

FIG. 6 is a flowchart of a method for preparing a touch screen provided by an embodiment of the present technical solution.

FIG. 7 is a scanning electron micrograph of a carbon nanotube film before laser treatment provided by an embodiment of the present technical solution.

FIG. 8 is a scanning electron micrograph of a laser treated carbon nanotube film provided by an embodiment of the present technical solution.

FIG. 9 is a schematic flow chart of continuously preparing a first electrode plate or a second electrode plate according to an embodiment of the present technical solution.

10‧‧‧ touch screen

12‧‧‧First electrode plate

14‧‧‧Second electrode plate

16‧‧‧ point spacers

18‧‧‧Insulation

120‧‧‧First substrate

122‧‧‧First conductive layer

124‧‧‧First electrode

140‧‧‧Second substrate

142‧‧‧Second conductive layer

144‧‧‧second electrode

Claims (18)

A method for preparing a touch screen, comprising the steps of: providing a first substrate; forming a carbon nanotube composite layer on a surface of the first substrate to obtain a first electrode plate, wherein the carbon nanotube composite layer comprises a carbon nanotube layer and a polymer material penetrating the carbon nanotube layer; repeating the above steps to prepare a second electrode plate; and packaging the first electrode plate and the second electrode plate to form a touch screen. The method for preparing a touch panel according to claim 1, wherein the method for forming a carbon nanotube composite layer on a surface of the first substrate comprises the step of: coating a surface of the first substrate a polymer material solution layer; preparing a carbon nanotube film; treating the carbon nanotube film by laser to improve transparency of the carbon nanotube film; and laying the at least one carbon nanotube film on the first substrate On the surface of the polymer material solution, a carbon nanotube layer is formed; the polymer material layer is infiltrated into the carbon nanotube layer, and the polymer material is solidified to form the carbon nanotube composite material layer. The method for preparing a touch panel according to claim 2, wherein the laser has a power density greater than 0.1×10 ⁴ watts/square meter. The method for preparing a touch panel according to claim 2, wherein the step of laying at least one layer of the carbon nanotube film on the surface of the polymer material solution on the first substrate is: The carbon nanotube film is directly laid on the surface of the polymer material solution or a plurality of carbon nanotube films Parallel without gaps or overlapping on the surface of the polymer material solution. The method for preparing a touch panel according to claim 2, wherein the carbon nanotube film comprises a carbon nanotube film structure, and the carbon nanotubes in the carbon nanotube film structure The same direction is preferred. The method for preparing a touch panel according to claim 5, wherein the method for preparing the carbon nanotube film structure comprises the steps of: providing a carbon nanotube array; and selecting a portion from the carbon nanotube array. The carbon nanotubes are stretched at a certain speed along a growth direction substantially perpendicular to the growth direction of the carbon nanotube array to form a continuous carbon nanotube film structure. The method for preparing a touch panel according to claim 2, wherein the method for infiltrating the polymer material layer into the carbon nanotube layer is to blow the nanocarbon with a wind knife at a wind speed of 10-20 m/sec. The tube layer further comprises a layer of a polymer material laminated on the carbon nanotube, and the polymer material layer is infiltrated into the carbon nanotube layer. The method for preparing a touch panel according to claim 2, wherein the method for curing the polymer material comprises heating the polymer material solution to a certain temperature. The method for preparing a touch screen according to claim 2, wherein the method for curing the polymer material solution is to place the polymer solution in a furnace to heat or irradiate the polymer material solution with ultraviolet light of a certain energy. The method for preparing a touch panel according to claim 1, wherein the method for preparing the first electrode plate or the second electrode plate can be continuously performed by using a continuous operation device. The method for preparing a touch screen according to claim 10, wherein the continuous working device comprises a first rotating shaft, a second rotating shaft, a third rotating shaft, a wide mouth container, a loading platform, and a A tubular furnace, a traction device, a blowing device, a scraping device, a laser device and a power source. The method for manufacturing a touch panel according to claim 11, wherein the first rotating shaft, the second rotating shaft and the third rotating shaft are spaced apart from each other, and the axial directions thereof are in the same direction. The method for preparing a touch panel according to claim 11, wherein the third rotating shaft and the pulling device are disposed at both ends of the axial direction of the tubular furnace. The method for preparing a touch panel according to claim 11, wherein the blowing device is disposed between the third rotating shaft and the tubular furnace. The method for preparing a touch panel according to claim 11, wherein the wide-mouth container is disposed below the second rotating shaft, and the second rotating shaft portion is located in the wide-mouth container. The method for preparing a touch screen according to claim 11, wherein the scraping device is disposed adjacent to the second rotating shaft, and one end of the scraping device is maintained at a fixed distance from the second rotating shaft. The method for preparing a touch panel according to claim 11, wherein the first rotating shaft is wound with a flexible substrate, and the wide-mouth container contains a polymer material solution. The method for preparing a touch panel according to claim 17, wherein the method for preparing an electrode plate by using a continuous working device comprises the steps of: sequentially passing a flexible substrate through a second rotating shaft, a third rotating shaft, and passing through the tubular type. The furnace is connected with the traction device to form a layer of polymer material on the surface of the flexible substrate; a super-sequential carbon nanotube array is fixed on the stage, and a continuous pull is drawn from the array of the super-sequential carbon nanotubes The carbon nanotube film structure, the end of the carbon nanotube film structure is adhered to the polymer material layer on the surface of the flexible substrate; Turn on the power supply, so that the traction device pulls the flexible substrate, the polymer material layer and the carbon nanotube film in the direction parallel to the axial direction of the tube furnace, and the air knife infiltrates the polymer material into the carbon nanotube film and solidifies through the tube furnace. The polymer material forms a carbon nanotube composite layer on the surface of the flexible substrate; the electrode substrate is obtained by cutting the flexible substrate on which the composite layer is formed.