TWI520185B - Method of fabricating transparent electrode for touch panel and transparent electrode for touch panel provided by the same - Google Patents

Description

Method for preparing transparent electrode of touch panel and transparent electrode of touch panel prepared by using same

The invention relates to a method for preparing a transparent electrode of a touch panel and a transparent electrode of the touch panel prepared by using the method, in particular to a method for preparing a transparent electrode using a touch panel of a single carbon nanotube and The transparent electrode of the touch panel produced by the method.

With the development of various electronic products, the application and use of touch panels in various aspects has also increased (for example, portable devices, notebook computers, etc.). According to the principle of induction, the touch panel can be divided into four types: capacitive type, infrared type, ultrasonic type and resistive type. Among them, the resistive touch panel is suitable for mobile phones, PDAs and other mobile devices due to its light weight, thin thickness and low power consumption, and the capacitive touch panel can be used for cash machines and large entertainments due to its high durability. Machine and other public information purposes.

As shown in FIG. 1 , it is a basic structure of a common F/G resistive touch panel, F represents an upper substrate as a film material, and G represents a lower substrate as a glass. The basic structure is composed of two transparent conductive sheets, which are respectively referred to as an upper electrode 11 and a lower electrode 12, and the two electrodes 11, 12 have transparent substrates 13, 14 and transparent conductive plates respectively plated on the substrates 13, 14. Film 15,16. The conductive surfaces of the two electrodes 11, 12 are opposed to each other, and the bonding agent 17 is used as a support therebetween, and a dot spacer 18 is spin-coated on the lower substrate 13, thereby completing the basic structure of the resistive touch. When the finger is biased by the upper substrate, the spacers 18 are moved by the external force to make the lower electrode above the applied point, and a current signal is generated to the controller to transmit an instruction.

In the control panel structure, the transparent conductive film is a very important material. The commonly used TCO (Transparent Conductive Oxide) transparent metal oxide film such as ITO (indium tin oxide), FTO (fluorinated tin dioxide), ATO (tin oxide)锑) and other materials are directly deposited on the upper and lower substrates by sputtering method, which is the current material mainstream due to the simple process. However, its poor light transmission, inflexibility and susceptibility to cracking make its application limited.

As the next generation of flexible electronic components begins to develop, the requirements for various characteristics of transparent conductive films will become stricter. Therefore, there is a need in the art to develop a novel material that can smoothly replace traditional transparent materials and become various The mainstream of the touch panel electrode materials.

Accordingly, the present invention provides a method for preparing a transparent electrode of a touch panel, comprising the steps of: (A) placing a plurality of metal-containing nanoparticles in a solvent to form a catalyst; and (B) providing a substrate. Soaking the substrate in the catalyst; (C) taking out the soaked substrate, and calcining the substrate; and (D) heating the calcined substrate while providing an alcohol The gas source is grown such that a plurality of monoterpene carbon nanotubes are formed on the surface of the substrate by the growth gas of the alcohol, wherein the plurality of monoterpene carbon nanotubes are interconnected to form a film of a network structure.

The method for preparing the transparent electrode of the touch panel of the present invention is to grow high-purity single-walled carbon nanotubes by using Alcohol Catalytic Chemical Vapor Deposition (ACCVD). A plurality of single-walled carbon nanotubes are interlaced to form a transparent electrode of a touch panel having a special appearance and characteristics. Since the transparent electrode of the touch panel formed by the single-walled carbon nanotube has high transmittance and electrical conductivity, the conventional transparent conductive material such as ITO, FTO, ATO can be successfully replaced.

In the prior art, the technology of using carbon nanotubes as electronic components is mostly based on a commercially available commercial carbon tube, and the nano-carbon tube material is dispersed on a substrate by a wet spin coating technique. However, due to the strong van der Waals force between the nano materials, it is easy to cause the material to agglomerate and not easily disperse, so that the material density can not be precisely controlled, resulting in serious problems such as excessive variation of component characteristics and difficulty in improving the transmission efficiency of the active region. In addition, in the prior art, it is generally a growth method in which explosive methane or acetylene is used together with hydrogen as a gas source, and thus safety is poor. The method for preparing the transparent electrode of the touch panel of the present invention is carried out using an alcohol gas, so that the safety can be greatly improved.

The characteristics of the transparent electrode of the touch panel produced by the present invention and the conventional transparent conductive film are as shown in Table 1 below.

The method for preparing the transparent electrode of the touch panel of the present invention, after the step (D), preferably further comprises the steps of: (E) forming a polymer film on the film; and (F) heat treating the polymer film. a film that binds the film to the polymer film; and (G) separates the film from the substrate.

In the method for preparing the transparent electrode of the touch panel of the present invention, the heat treatment temperature in the step (F) is preferably from 50 to 100 °C.

The method for preparing a transparent electrode of the touch panel of the present invention, wherein in the step (D), the temperature of the substrate is preferably from 600 ° C to 900 ° C.

The method for preparing a transparent electrode of the touch panel of the present invention, wherein in the step (D), the growing gas source of the alcohol is preferably: methanol, ethanol, propanol, isopropanol, n-butanol a group consisting of isobutanol, n-pentanol, and a mixture thereof; the best system uses ethanol, but is not limited thereto.

In the method for preparing a transparent electrode of the touch panel of the present invention, in the step (C), the temperature of the calcination treatment may preferably be 320 ° C to 480 ° C.

The method for preparing a transparent electrode of the touch panel of the present invention, wherein the step (D) and the step (C) preferably further comprise a step (D0) of providing an ammonia gas for the reduction reaction.

The method for preparing a transparent electrode of the touch panel of the present invention, wherein in the step (D), the thickness of the network structure film formed by interconnecting a plurality of single-twisted carbon nanotubes is preferably 10 nm to 200 nm. More preferably, it is from 10 nm to 20 nm in view of light transmittance.

The method for preparing a transparent electrode of a touch panel of the present invention, wherein in the step (A), the metal of the plurality of metal-containing nano particles is preferably selected from the group consisting of cobalt, molybdenum, and a mixture thereof. The metal-containing nanoparticle is preferably a group consisting of cobalt acetate, molybdenum acetate, iron acetate, nickel acetate, and a mixture thereof; preferably cobalt acetate or molybdenum acetate. The inventors of the present invention have developed a nanocarbon tube by using a solution in which different powders are dissolved in ethanol and growing the carbon nanotubes with the same parameters. After experimental analysis, it is found that a solution in which cobalt acetate and molybdenum acetate are dissolved in ethanol can have a higher growth density. A single-walled carbon nanotube film with a better G/D ratio.

In the preparation method of the transparent electrode of the touch panel of the present invention, in the step (A), the solvent is preferably selected from the group consisting of ethanol, methanol, propanol, isopropanol, n-butanol, isobutanol and n-pentane. a group of alcohols and mixed solutions thereof. Further, the ratio of the solvent to the metal-containing nanoparticle is preferably [metal-containing nanoparticle: solvent] = 0.01 to 0.05% by weight.

The method for preparing a transparent electrode of the touch panel of the present invention, wherein the diameter of the plurality of monoterpene carbon nanotubes formed in the step (D) is preferably 0.5 to 2.0 nm, more preferably 0.8 to 1.2 nm. .

The method for preparing a transparent electrode of a touch panel of the present invention, wherein in the step (D), the plurality of formed monoterpene carbon nanotubes are analyzed by Raman Scattering Spectrum, and the obtained G is obtained. The /D ratio is preferably from 10 to 25, more preferably from 10 to 20.

The present invention further provides a transparent electrode of a touch panel, comprising: a substrate; and a plurality of single carbon nanotubes, the plurality of carbon nanotubes are disposed on the substrate, and the plurality of single carbon nanotubes are interconnected to form a network structure The film, and the plurality of monoterpene carbon nanotubes were analyzed by Raman Scattering Spectrum to obtain a G/D ratio of 10 to 25.

The transparent electrode of the touch panel of the present invention has a special type (including a film in which a plurality of single-twisted carbon nanotubes are interconnected to form a network structure), wherein the film thickness can be arbitrarily adjusted according to requirements, and The transparent electrode of the touch panel formed by the wall carbon nanotube has high transmittance and conductivity, and the manufacturing cost is low, so that the conventional transparent conductive material such as ITO, FTO, ATO can be successfully replaced.

The transparent electrode of the touch panel of the present invention may preferably be a germanium substrate, a quartz substrate, a general glass substrate, a high temperature resistant glass substrate, or a flexible substrate such as a plastic substrate.

The transparent electrode of the touch panel of the present invention, wherein the polymer material is preferably polydimethyl siloxane (PDMS), polymethyl methacrylate (PMMA), or poly pair. Parylene (poly-para-xylylen).

In the transparent electrode of the touch panel of the present invention, the thickness of the network structure film formed by interconnecting a plurality of individual tantalum carbon nanotubes may preferably be 100 nm to 400 nm.

The present invention further provides a touch panel comprising: a first transparent electrode; a second transparent electrode disposed opposite to the first transparent electrode; and a plurality of spaced-apart electrodes disposed on the first transparent electrode and the second transparent electrode And a bonding agent connecting the first transparent electrode and the second transparent electrode, wherein the first transparent electrode system comprises: a substrate; and a plurality of single-sized carbon nanotubes on the substrate, wherein A plurality of monoterpene carbon nanotubes are interconnected to form a film of a network structure, and the plurality of monoterpene carbon nanotubes are analyzed by Raman Scattering Spectrum to obtain a G/D ratio of 10 To 25.

The touch panel of the present invention is a resistive touch panel. When the finger is biased by the second transparent electrode, the interval between the first transparent electrode and the second transparent electrode is removed by an external force. A transparent electrode is in contact with the second transparent electrode to generate a current signal to the controller to transmit an instruction.

Since the touch panel of the present invention forms a transparent electrode by a single-walled carbon nanotube, and the transparent electrode has high transmittance and conductivity, it can be successfully replaced by a conventional transparent conductive material such as ITO, FTO, or ATO. Transparent electrode touch panel.

In the touch panel of the present invention, the second transparent electrode preferably has the same structure as the first transparent electrode. That is, the second transparent electrode may preferably include: a substrate; and a plurality of single-sized carbon nanotubes on the substrate, the plurality of monoterpene carbon nanotubes being interconnected to form a film of a network structure, And the plurality of monoterpene carbon nanotubes were analyzed by Raman Scattering Spectrum to obtain a G/D ratio of 10 to 25.

In the touch panel of the present invention, the material of the substrate may preferably be a germanium substrate, a quartz substrate, a general glass substrate, a high temperature resistant glass substrate, or a flexible substrate such as a plastic substrate.

In the touch panel of the present invention, the polymer material may preferably be polydimethyl siloxane (PDMS), polymethyl methacrylate (PMMA), or parylene (Parylene). Poly-para-xylylen).

In the touch panel of the present invention, the thickness of the network structure film formed by interconnecting a plurality of single-twisted carbon nanotubes is preferably 10 nm to 200 nm, and more preferably 10 nm in consideration of light transmittance. 20nm.

[Example 1]

The method for preparing the transparent electrode of the touch panel of the embodiment includes the following steps. First, (A) a plurality of metal-containing nanoparticles (here, using cobalt acetate powder and molybdenum acetate powder) are placed in a solvent to form a catalyst, in which the solvent is ethanol, cobalt acetate and acetic acid. The ratio of molybdenum to ethanol is [cobalt acetate and molybdenum acetate: ethanol] = 0.01 wt%. Next, (B0) a glass substrate having a thickness of 1.1 mm is provided, and the substrate is placed in the surface to increase the hydrophilicity of the surface of the substrate. Next, (B) the substrate was immersed in the catalyst to adhere a catalyst to the surface of the substrate. Then, (C) the immersed substrate was taken out, and the substrate was subjected to calcination treatment, wherein the calcination temperature was 400 °C. Then, (D0) provides ammonia gas and argon gas to carry out a reduction reaction on the surface of the calcined substrate, the reduction reaction is 30/200 sccm of ammonia/argon gas, the temperature is 350 ° C to 750 ° C, and the pressure is 15- In the condition of 20torr. Next, (D) heating the calcined and reduced substrate to 750 ° C, and simultaneously providing a growing gas source of alcohol (in this case, using a purity of 99.9% or more of ethanol, a pressure of 690 torr, a temperature of 50 ° C a plurality of monoterpene carbon nanotubes (growth time of 15 minutes, using an ACCVD apparatus) formed by the growth gas of the alcohol from the surface of the substrate, wherein the plurality of monoterpene carbon nanotubes are mutually The film is formed to form a network structure, and the thickness of the network structure film is about 10-20 nm.

2a and 2b are respectively a side view and a perspective view of a transparent electrode (a single-walled carbon nanotube film directly grown on a glass substrate) of the touch panel of the present embodiment, and the transparent electrode of the embodiment can be used as a resistor The lower electrode of the touch panel is a single-walled carbon nanotube film having a thickness of about 10-20 nm by using an ACCVD instrument and adjusting appropriate process parameters, since the single-walled carbon nanotube system directly grows on the glass substrate. Upper, so the distribution uniformity is excellent.

As shown in FIG. 2a and FIG. 2b, the transparent electrode 2 of the touch panel prepared in this embodiment includes: a substrate 21; and a plurality of single carbon nanotubes 221 disposed on the substrate 21, and the plurality of sheets The carbon nanotubes 221 are interconnected to form a film 22 of a network structure.

The different wavelength illumination-transparency test results of the transparent electrode of this embodiment are shown in FIG. As can be seen from FIG. 3, the transparent electrode of the present embodiment has a light transmittance of about 94% to 96% in the visible light range, which is much higher than that of the conventional ITO transparent electrode. Further, after analysis by Raman Scattering Spectrum, the G/D ratio of the plurality of monoterpene carbon nanotubes of the transparent electrode of the present embodiment is about 10 to 20.

[Embodiment 2]

In this embodiment, a single-walled carbon nanotube is attached to a flexible substrate by a transfer method as a transparent electrode of the touch panel. The preparation step includes the steps in the first embodiment (steps (A) to (D)), as shown in FIGS. 4a-4b, and further includes the step after the step (D): (E) using polymethacrylic acid A polymer material of a methyl ester (PMMA) colloidal solution is spin-coated on a film 22 containing a single-walled carbon nanotube to form a polymer film 23 on the film 22; and then, (F) is placed in a vacuum system ( In the drawing, the film 22 coated with the polymer film 23 is heat-treated to 75 ° C, and the polymer film 23 of the PMMA colloidal solution is sufficiently combined with the single-walled carbon nanotube film 22, and then taken out and cooled; finally, As shown in FIG. 4b, (G) the film 22 bonded to the polymer film 23 is completely separated from the substrate 21, and the transparent electrode 3 of the touch panel of the present embodiment is obtained.

In this embodiment, as shown in FIG. 4b, the film 22 for carrying the network structure of the plurality of single carbon nanotubes 221 is a polymer film 23, and the thickness of the polymer film 23 is about 200 μm, and the polymer The film 23 has flexibility, so the transparent electrode 3 of the present embodiment is very suitable for use as an upper electrode of a touch panel.

The different wavelength illumination-transmittance test results of the transparent electrode of this embodiment are shown in FIG. 5. As can be seen from FIG. 5, the transparent electrode of the present embodiment has a light transmittance of about 86% to 91% in the visible light range.

[Example 3]

As shown in FIG. 6 , the touch panel 4 of the present embodiment includes: a first transparent electrode 2; a second transparent electrode 3 disposed opposite to the first transparent electrode 2; The first transparent electrode 2 and the second transparent electrode 3 are connected between the first transparent electrode 2 and the second transparent electrode 3; and the bonding agent 25 is connected to the first transparent electrode 2 and the second transparent electrode 3. In the present embodiment, the first transparent electrode 2 is the transparent electrode 2 obtained in the first embodiment, and the second transparent electrode 3 is the transparent electrode 3 obtained in the second embodiment. Therefore, the detailed structure thereof will not be described herein.

The touch panel 4 of the present embodiment is a resistive touch panel. When the finger is biased by the second transparent electrode 3, the interval 24 between the first transparent electrode 2 and the second transparent electrode 3 is due to an external force. The first transparent electrode 2 is brought into contact with the second transparent electrode 3 to generate a current signal to the controller to transmit an instruction.

Since the touch panel of the present embodiment forms a transparent electrode by using a single-walled carbon nanotube, and the transparent electrode has high transmittance and conductivity, it can successfully replace the conventional transparent conductive materials such as ITO, FTO, and ATO. A touch panel forming a transparent electrode.

In summary, the present invention provides a method for preparing a transparent electrode of a touch panel, and a transparent electrode of the touch panel produced by the method. The method for preparing the transparent electrode of the touch panel of the present invention is to grow high-purity single-walled carbon nanotubes by using Alcohol Catalytic Chemical Vapor Deposition (ACCVD). A plurality of single-walled carbon nanotubes are interlaced to form a transparent electrode of a touch panel having a special appearance and characteristics. Since the transparent electrode of the touch panel formed by the single-walled carbon nanotube has high transmittance and electrical conductivity, the conventional transparent conductive material such as ITO, FTO, ATO can be successfully replaced.

The above-mentioned embodiments are merely examples for convenience of description, and the scope of the claims is intended to be limited to the above embodiments.

11,12. . . electrode

13,14. . . Substrate

15,16. . . Transparent conductive film

17. . . Adhesive

18,24. . . Interval

2,3. . . Transparent electrode

twenty one. . . Substrate

twenty two. . . film

221. . . Single carbon nanotube

twenty three. . . Polymer film

25. . . Adhesive

4. . . Touch panel

FIG. 1 is a basic structure of a conventional resistive touch panel.

2a and 2b are respectively a side view and a perspective view of a transparent electrode of a touch panel according to Embodiment 1 of the present invention.

Fig. 3 is a graph showing the results of different wavelength illumination-transmittance tests in the first embodiment of the present invention.

4a-4b are flowcharts showing the preparation of a transparent electrode of a touch panel according to Embodiment 2 of the present invention.

FIG. 5 is a graph showing the results of different wavelength illumination-transmittance tests of the transparent electrodes of the touch panel of Embodiment 2 of the present invention.

FIG. 6 is a schematic diagram of a touch panel according to Embodiment 3 of the present invention.

2. . . Transparent electrode

twenty one. . . Substrate

twenty two. . . film

221. . . Single carbon nanotube

Claims (13)

A method for preparing a transparent electrode of a touch panel, comprising the steps of: (A) placing a plurality of metal-containing nanoparticles in a solvent to form a catalyst, wherein the metal of the plurality of metal-containing nanoparticles is selected Free: a group consisting of cobalt, molybdenum, and mixtures thereof; (B) providing a substrate, immersing the substrate in the catalyst; (C) taking out the soaked substrate, and calcining the substrate And (D) heating the calcined substrate, and simultaneously providing a growing gas source of alcohol, so that a plurality of monoterpene carbon nanotubes are formed on the surface of the substrate by the growth gas of the alcohol, Wherein, the plurality of monoterpene carbon nanotubes are interconnected to form a film of a network structure. The method for preparing a transparent electrode of a touch panel according to claim 1, wherein the step (D) further comprises the steps of: (E) forming a polymer film on the film; (F) heat treating the coating a film of a polymer film that binds the film to the polymer film; and (G) separates the film from the substrate. The method for preparing a transparent electrode of a touch panel according to claim 2, wherein the heat treatment temperature in the step (F) is 50 to 100 °C. The method for preparing a transparent electrode of a touch panel according to claim 1, wherein in the step (D), the substrate is heated at a temperature of 600 ° C to 900 ° C. The method for preparing a transparent electrode of a touch panel according to claim 1, wherein in the step (D), the growth source of the alcohol is selected Free: a group consisting of methanol, ethanol, propanol, isopropanol, n-butanol, isobutanol, n-pentanol, and mixtures thereof. The method for preparing a transparent electrode of a touch panel according to claim 1, wherein in the step (C), the temperature of the calcination treatment is 320 ° C to 480 ° C. The method for preparing a transparent electrode of a touch panel according to the first aspect of the invention, wherein the step (D) and the step (C) further comprise a step (D0): providing an ammonia gas for reduction reaction. The method for preparing a transparent electrode of a touch panel according to claim 1, wherein in the step (D), the thickness of the network structure film formed by interconnecting a plurality of single-tube carbon nanotubes is 10nm~20nm. The method for preparing a transparent electrode of a touch panel according to claim 1, wherein in the step (D), the plurality of monoterpene carbon nanotubes formed by Raman Scattering Spectrum After the analysis, the obtained G/D ratio was 10 to 25. A transparent electrode of a touch panel, comprising: a substrate; and a plurality of single carbon nanotubes, the plurality of single carbon nanotubes are connected to each other, and the plurality of single carbon nanotubes are interconnected to form a film of a network structure, and The plurality of monoterpene carbon nanotubes were analyzed by Raman Scattering Spectrum to obtain a G/D ratio of 10 to 25. The transparent electrode of the touch panel according to claim 10, wherein the substrate is a glass substrate, a germanium substrate, a quartz substrate, or a polymer material substrate. The transparent electrode of the touch panel of claim 11, wherein the polymer material is polydimethyl siloxane (PDMS) or polymethyl methacrylate (PMMA). Or parylene (poly-para-xylylen). The transparent electrode of the touch panel according to claim 10, wherein the thickness of the network structure film formed by interconnecting a plurality of single-tube carbon nanotubes is 10 nm to 20 nm.