TW201445404A - Transparent conductive film structure and touch panel thereof - Google Patents

Abstract

A transparent conductive film structure at least comprises a substrate and two and more transparent conductive layers. These transparent conductive layers are at least composed of SnO2 and In2O3 with different weight percentage. By using specific composition percentage, process temperature and time of film deposition can be reduced. As a result, energy consumption and costs can be reduced; transparent conductive films with low impedance are obtained. A touch panel structure is also disclosed here, which can be applied to capacitive touch panels.

Description

Transparent conductive laminated film structure and touch panel thereof

The present invention relates to a transparent conductive laminated film structure and a touch panel thereof, and more particularly to a transparent conductive laminated film structure and a touch panel thereof which can reduce process temperature and time and have low impedance properties.

At present, transparent conductive films have a wide range of applications, and are used for preventing transparent articles from being charged, blocking electromagnetic waves, and the like in addition to transparent electrodes used in liquid crystal displays, electroluminescent displays, and touch panels. For touch panels, it can be applied to capacitive touch panels.

In the transparent conductive film, a transparent conductive layer is generally formed on a glass substrate by metal oxide deposition. However, since the substrate is glass, flexibility and workability are poor, and the application range is also limited.

Therefore, in recent years, in order to satisfy properties such as flexibility, workability, impact resistance, and weight reduction, the substrate has been modified into various types of polymer materials such as polyethylene terephthalate film.

However, taking a polymer substrate will encounter two problems in the process. First, since the substrate is composed of a polymer material, when the transparent conductive layer is deposited, thermal deformation is likely to occur. Second, after the deposition process is completed, in order to further improve the properties of the transparent conductive film, an annealing process is required to eliminate the internal stress and defects of the transparent conductive layer, and recrystallize and crystal grain growth to obtain low resistance and high transmittance. High durability and other characteristics. However, due to the limitation of the polymer substrate, high temperature annealing at 200 ° C cannot be used, and the annealing time is prolonged at a lower temperature, resulting in a waste of process time and energy. Furthermore, the uniformity of the temperature distribution inside the annealing chamber tends to affect the final yield, so it is desirable to be able to obtain in a relatively short period of time, The coating quality of the crystal can be formed at a lower temperature.

In addition, in the case of capacitive touch panels, especially projected capacitive touch panels, it is desirable to increase their sensitivity and resolution, so a low-impedance (surface resistance or specific resistance) transparent conductive layer is also a key factor.

In view of this, a transparent conductive laminated film structure capable of reducing process temperature and time and having low impedance properties should be developed to solve the above problems.

The present invention provides a transparent conductive laminated film structure comprising a substrate and two or more transparent conductive films, wherein the transparent conductive film is composed of at least SnO ₂ and In ₂ O ₃ and has different weight percentages. By using a specific composition ratio, the process temperature of the transparent conductive laminated film structure can be reduced, and the process time can be reduced. In this way, not only energy is saved, but also the problem of thermal deformation of the substrate is avoided. At the same time, a touch panel structure is disclosed, which can be applied to a capacitive touch panel, such as a projected capacitive touch panel.

In order to solve the problems of the prior art, an embodiment of the present invention provides a transparent conductive laminated film structure comprising, in order from the bottom up, a substrate and two or more transparent conductive films. The transparent conductive film includes at least a first transparent conductive film and a second transparent conductive film. The first transparent conductive film is disposed on the substrate and is composed of at least SnO ₂ and In ₂ O ₃ , wherein the weight percentage of the SnO ₂ is 6% to 7.5%. The second transparent conductive film is disposed on the first transparent conductive film and is composed of at least SnO ₂ and In ₂ O ₃ , wherein the weight percentage of the SnO ₂ is 9% to 15%.

According to another embodiment of the present invention, a touch panel structure includes at least two transparent conductive laminated film structures stacked on top of each other, and a dielectric layer is disposed between two transparent conductive laminated film structures, wherein any transparent conductive The laminated film structure includes a substrate and two or more transparent conductive films in this order from the bottom to the bottom. The transparent conductive film includes at least a first transparent conductive film and a second transparent conductive film. The first transparent conductive film is disposed on the substrate and is composed of at least SnO ₂ and In ₂ O ₃ , wherein the weight percentage of the SnO ₂ is 9% to 15%. The second transparent conductive film is disposed on the first transparent conductive film and is composed of at least SnO ₂ and In ₂ O ₃ , wherein the weight percentage of the SnO ₂ is 6% to 7.5%.

The purpose, technical contents, features, and effects achieved by the present invention will become more apparent from the detailed description of the appended claims.

1‧‧‧Transparent conductive laminated film structure

10‧‧‧Substrate

20‧‧‧First transparent conductive film

30‧‧‧Second transparent conductive film

40‧‧‧ Filling layer

50‧‧‧Transparent protective film

60‧‧‧ hardened layer

100‧‧‧Touch panel structure

110‧‧‧First transparent conductive laminated film structure

111‧‧‧First substrate

112‧‧‧First transparent conductive film

113‧‧‧Second transparent conductive film

120‧‧‧Second transparent conductive laminated film structure

121‧‧‧second substrate

122‧‧‧ Third transparent conductive film

123‧‧‧fourth transparent conductive film

130‧‧‧Optical adhesive layer

1A and 1B are partial cross-sectional views showing a structure of a transparent conductive base film according to an embodiment of the present invention.

2 is a partial cross-sectional view showing the structure of a touch panel according to an embodiment of the invention.

3 is a partial cross-sectional view showing the structure of a touch panel according to another embodiment of the present invention.

Please refer to FIG. 1A. FIG. 1A is a partial cross-sectional view showing the structure of a transparent conductive laminated film according to an embodiment of the present invention. The transparent conductive laminated film structure 1 comprises, in order from the bottom up, a substrate 10 and two or more transparent conductive films. The transparent conductive film includes at least a first transparent conductive film 20 and a second transparent conductive film 30. The first transparent conductive film 20 is disposed on the substrate 10 and is composed of at least SnO ₂ and In ₂ O ₃ , wherein the weight percentage of the SnO ₂ is 6% to 7.5%. The second transparent conductive film 30 is disposed on the first transparent conductive film 20 and is composed of at least SnO ₂ and In ₂ O ₃ , wherein the weight percentage of the SnO ₂ is 9% to 15%.

The method of depositing the transparent conductive film can be performed by physical vapor deposition, for example, a standard magnetron sputtering method using a DC (Direct Current) power source, RF (Radio Frequency) sputtering, and RF+DC sputtering. , pulse sputtering, dual-target magnetron sputtering or other sputtering methods.

In an embodiment, please refer to FIG. 1A, wherein the thickness of the first transparent conductive film 20 accounts for 40% to 60% of the total thickness of the first transparent conductive film 20 and the second transparent conductive film 30, and the first transparent conductive The thickness of the film 20 and the thickness of the second transparent conductive film are both 9 nm to 20 nm. In still another embodiment, the total thickness of the first transparent conductive film 20 and the second transparent conductive film 30 is less than 35 nm.

In one embodiment, referring to FIG. 1A , the transparent conductive laminated film structure 1 further includes one or more filling layers 40 disposed between the first transparent conductive film 20 and the substrate 10 . When the substrate 10 is composed of a polymer material, it is easy to roughen the surface of the substrate due to the polymer particles. The fill layer 40 can fill the surface of the substrate and reduce the roughness to obtain good optical properties. The fill layer 40 is either formed by wet coating or by dry sputtering.

In another embodiment, referring to FIG. 1B, the transparent conductive laminated film structure 1 further includes a transparent protective film 50 disposed on the second transparent conductive film 30 for protecting the second transparent conductive film 30 and improving the touch. The durability of the finished panel, and to reduce or avoid external physical impact, sharp object scratching, moisture or chemical intrusion and other physical and chemical damage. In addition, the transparent conductive laminated film structure 1 may further include a hardened layer 60 (shown in FIG. 1B) disposed under the substrate 10 to protect the substrate 10.

In one embodiment, referring to FIGS. 1A and 1B, the substrate 10 is composed of a polymer material such as a polyester resin, a polycarbonate resin, or a polyolefin resin, and is a transparent substrate.

The transparent conductive laminated film structure of the present invention adopts a specific range of composition ratio, and changes the properties of deposition and crystallization of the transparent conductive film, thereby reducing the process temperature and time. In the prior art, in the case of physical sputtering, when the substrate is plated with a transparent conductive film, the substrate needs to be heated to 140 ° C. After the coating is completed, annealing treatment at 140 ° C for several hours is required to obtain good crystal properties. In contrast, the present invention can employ a lower temperature (less than 100 ° C) process when depositing a transparent thin film. The substrate only needs to be heated to below 80 ° C, preferably 40 ° C to 50 ° C, to complete the coating, avoiding thermal deformation of the polymer substrate. In addition, after the coating is completed, an annealing process is required. According to the transparent conductive laminated film structure of the present invention, only annealing for 30 minutes to 40 minutes is required, and processes such as eliminating defects and internal stress, recrystallization, and grain growth can be completed, which greatly saves process time, energy, and cost. The transparent conductive layer after crystallization has low impedance, high transmittance, high durability, and the like, wherein the impedance value (surface resistance) is distributed between 85 and 170 Ω/□ (ohm/square), preferably, It is suitable for capacitive touch panels with 150 Ω/□, especially for projected electrostatic capacitance touch panels.

In addition, a touch panel structure is also disclosed herein, which uses the transparent conductive laminated film structure 1 previously described. That is, a touch panel structure comprising at least two transparent conductive laminated film structures stacked one on top of the other, wherein any of the transparent conductive laminated film structures sequentially comprises a substrate and two or more transparent conductive films from the bottom thereof. The transparent conductive film includes at least a first transparent conductive film and a second transparent conductive film. The first transparent conductive film is disposed on the substrate and is composed of at least SnO ₂ and In ₂ O ₃ , wherein the weight percentage of the SnO ₂ is 9% to 15%. The second transparent conductive film is disposed on the first conductive film and is composed of at least SnO ₂ and In ₂ O ₃ , wherein the weight percentage of the SnO ₂ is 6% to 7.5%.

In one embodiment, please refer to FIG. 2. FIG. 2 is a partial cross-sectional view showing the structure of a touch panel according to an embodiment of the invention. The touch panel structure 100 includes at least a first transparent conductive laminated film structure 110, a second transparent conductive laminated film structure 120 stacked on top of each other, and an optical adhesive layer 130 for adhering the first transparent conductive laminated film structure 110 and the second Transparent conductive laminated film structure. The first transparent conductive laminated film structure 110 includes a first substrate 111 sequentially from the bottom thereof; a first transparent conductive film 112 is disposed on the first substrate 111 and is composed of at least SnO ₂ and In ₂ O ₃ , wherein The weight percentage of SnO ₂ is 9% to 15%; and a second transparent conductive film 113 is disposed on the first transparent conductive film 112 and composed of at least SnO ₂ and In ₂ O ₃ , wherein the weight percentage of SnO ₂ For example, 6% to 7.5%. The second transparent conductive laminated film structure 120 is disposed above the first transparent conductive laminated film structure 110, wherein the second transparent conductive laminated film structure 120 sequentially includes a second substrate 121 from the bottom thereof; a third transparent conductive film 122 is disposed on the second substrate 121 and is composed of at least SnO ₂ and In ₂ O ₃ , wherein the weight percentage of SnO ₂ is 9% to 15%; and a fourth transparent conductive film 123 is disposed on the third transparent conductive The film 122 is composed of at least SnO ₂ and In ₂ O ₃ , wherein the weight percentage of SnO ₂ is 6% to 7.5%. As shown in FIG. 2, the two transparent conductive laminated films 110 and 120 are stacked up and down. In addition, as shown in FIG. 3, in another embodiment, the two transparent conductive laminated films 110 and 120 are vertically stacked on the opposite side (symmetrically centered on the optical adhesive layer 130), and the digital symbols shown in FIG. The description of Figure 2 above is not to be said.

The touch panel structure 100 (shown in FIG. 2) is mainly operated by measuring a change in the capacitance value of the upper and lower transparent conductive laminated film structures after applying a pressure (for example, a finger press) to the transparent conductive layer. Get the result of on or off.

In an embodiment, please refer to FIG. 2 , wherein the thickness of the first transparent conductive film 112 accounts for 40% to 60% of the total thickness of the first transparent conductive film 112 and the second conductive film 113, and the first transparent conductive film 20 The thickness and the thickness of the second transparent conductive film are both 9 to 20 nm. In still another embodiment, the total thickness of the first transparent conductive film 112 and the second conductive film 113 is less than 35 nm. In still another embodiment, the first transparent conductive film 112 and the second transparent conductive film 113 have a surface resistance of 85 to 170 Ω/□ (ohm/square). Preferably, it is 150 Ω/□. The above applies equally to the third transparent conductive film 122 and the fourth transparent conductive film 123. Since the touch panel structure 100 adopts a transparent conductive laminated film structure with a low impedance value, it can be applied to a capacitive touch panel such as a projected capacitive touch panel.

Experimental data tables are provided herein to illustrate the efficacy of the present invention. Please refer to Table 1. Table 1 shows the comparison results between the embodiment of the present invention and the comparative example of the prior art.

According to Table 1, Examples 1 to 4 employ the specific composition ratio of the present invention, and can be made transparent at a low coating temperature (40 ° C to 50 ° C) and a low annealing baking time (for example, 30 min or 50 min). The conductive film and the second transparent conductive film obtain a lower surface resistance (Ω/□) and a specific resistance Ω-cm. Therefore, the transparent conductive laminated film structure of the present invention can indeed obtain better properties.

In summary, the transparent conductive laminated film structure provided by the present invention comprises at least one substrate and two or more transparent conductive films, wherein the transparent conductive film is composed of at least SnO ₂ and In ₂ O ₃ and has different Weight percentage. By using a specific composition ratio, the process temperature of the transparent conductive laminated film structure can be reduced, and the process time can be reduced. In this way, not only energy is saved, but also the thermal deformation problem of the substrate is avoided, and a low-conductivity transparent conductive laminated film is obtained, which can be applied to a capacitive touch panel structure.

The embodiments and the drawings described above are only for explaining the technical idea and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the present invention. It is intended that the scope of the invention is not limited thereto, that is, the equivalents and modifications of the invention may be included in the scope of the invention.

1‧‧‧Transparent conductive laminated film structure

10‧‧‧Substrate

20‧‧‧First transparent conductive film

30‧‧‧Second transparent conductive film

40‧‧‧ Filling layer

Claims (10)

A transparent conductive laminated film structure comprising: a substrate from the bottom up; and a transparent conductive film of at least two layers, comprising: a first transparent conductive film disposed on the substrate, the transparent conductive laminated film structure The first transparent conductive film is composed of at least SnO ₂ and In ₂ O ₃ , wherein the weight percentage of SnO ₂ is 9% to 15%; and a second transparent conductive film is disposed on the first transparent conductive film, the first The two transparent conductive films are composed of at least SnO ₂ and In ₂ O ₃ , wherein the weight percentage of SnO ₂ is 6% to 7.5%. The transparent conductive laminated film structure of claim 1, wherein the first transparent conductive film has a thickness of 40% to 60% of a total thickness of the first transparent conductive film and the second conductive film, and the first conductive The thickness of the transparent film and the thickness of the second transparent conductive film are both 9 nm to 20 nm. The transparent conductive laminated film structure according to claim 1, wherein the first transparent conductive film and the second conductive film have a total thickness of less than 35 nm. The transparent conductive laminated film structure according to claim 1, further comprising a filling layer disposed between the first transparent conductive film and the substrate. The transparent conductive laminated film structure according to claim 1, wherein the substrate is composed of a polyester resin, a polycarbonate resin or a polyolefin resin. The transparent conductive laminated film structure according to claim 1, wherein the first transparent conductive film and the second transparent conductive film have a surface resistance of 85 to 170 Ω/□ (ohm/square). A touch panel structure comprising at least two transparent conductive laminated film structures stacked on top of each other, wherein any one of the transparent conductive laminated film structures comprises: a substrate upwardly from the bottom thereof; and two or more transparent conductive films, the at least comprising: a first transparent conductive film disposed on the substrate, the first transparent conductive film being composed of at least SnO ₂ and In ₂ O ₃ , wherein the weight percentage of SnO ₂ is 9% to 15%; and a second transparent conductive The film is disposed on the first transparent conductive film, and the second transparent conductive film is composed of at least SnO ₂ and In ₂ O ₃ , wherein the weight percentage of the SnO ₂ is 6% to 7.5%. The touch panel structure of claim 7, wherein the first transparent conductive film has a thickness of 40% to 60% of a total thickness of the first transparent conductive film and the second conductive film, and the first transparent conductive The thickness of the film and the thickness of the second transparent conductive film are both 9 nm to 20 nm. The touch panel structure of claim 7, wherein the first transparent conductive film and the second transparent conductive film have a surface resistance of 85 to 170 Ω/□ (ohm/square). The touch panel structure of claim 7, wherein the touch panel structure is a projected capacitive touch panel.