TW201546695A - Capacitive touch panel and display device comprising the same - Google Patents

Abstract

Disclosed is a capacitive touch panel, including a first electrode and a second electrode, which intersect in different directions on a single substrate, wherein the first electrode is configured such that a plurality of rhombic unit cells, each including a plurality of rhombic unit meshes, is connected by connection meshes, and the second electrode is configured such that a plurality of rhombic unit cells, each including a plurality of rhombic unit meshes, is separated at intersections with the first electrode and is connected by mesh bridges.

Description

Capacitive touch panel and display device including the same

The invention relates to a capacitive touch panel comprising a driving electrode and a sensing electrode patterned on a single layer.

Due to the worldwide use of mobile devices, the demand for touch panel devices has increased dramatically. In addition, with the improvement of the technology and stability of the touch panel device, the touch panel device is increasingly applied to various medium to large devices. Although touch panel devices have been applied to personal digital assistants (PDAs), race machines, navigation machines, point-of-sale management (POS) terminals, automated teller machines (ATMs), and the like, the relative quality of touch panels in the display industry Penetration is generally not high. However, touch panels are not only widely used in small mobile devices, but also in a wide variety of mobile multimedia products, especially for smart phones and tablet personal computers (PCs).

For touch panel devices, resistive touch panels that are inexpensive and have precise touch resolution are currently replaced by capacitive touch panels. Capacitive The touch surface is advantageous in terms of good touch functionality, durability, light transmittance, outdoor visibility, and panel thickness. In particular, capacitive touch panels are widely used in mobile devices having a size of 10 inches or less.

Such a touch panel includes transparent electrodes which are conventionally formed of indium tin oxide (ITO) or a conductive polymer such as polyoxyethylene thiophene/polystyrene sulfonate (PEDOT/PSS). The conductivity of ITO is suitable for small devices but not for large panels. The conductive polymer which appears as a substitute for ITO is advantageous for its high flexibility and handleability, but has poor electrical conductivity.

For this reason, research on the use of metals to form transparent electrodes has continued. The metal transparent electrode has excellent electrical conductivity and is abundant in supply compared to when ITO or a conductive polymer is used. However, when a metal is used to form an electrode, the transparency of the touch panel becomes a problem, which is attributable to the opacity of the metal.

Capacitive touch panels can be classified into two-layer touch panels and single-layer touch panels. The double-layer touch panel includes two substrates, that is, a substrate having a first electrode pattern and a substrate having a second electrode pattern, the substrates are spaced apart from each other, and an insulating material is interposed between the substrates to prevent the first An electrode pattern and the second electrode pattern are in contact with each other. Further, the upper substrate and the lower substrate are formed to have electrode wirings connected to the electrode patterns. The electrode wiring functions to make the first electrode pattern and when the input unit is in contact with the touch screen The change in capacitance occurring between the second electrode patterns is transferred to the control unit.

On the other hand, the single-layer touch panel includes a first electrode pattern and a second electrode pattern (FIG. 1) formed on a single substrate in different directions. The single-layer touch panel of FIG. 1 includes: a second electrode including a plurality of diamond-shaped (diamond-shaped) patterns connected by a connector; and a first electrode included in the second electrode A plurality of diamond patterns separated at the intersection and connected by bridges.

Thus, the connector or bridge has a very small width and therefore has a very high resistance, and the electrodes comprising a plurality of such connectors can have a reduced effective driving voltage due to the RC delay, and thus the touch functionality can become Sensitive, thereby degrading the sensing resolution undesirably.

[reference list]

[Patent Literature]

(Patent Document 1) Korean Patent Application Publication No. 10-2014-0017857.

(Patent Document 2) Korean Patent Application Publication No. 10-2013-0141761.

Accordingly, it is an object of the present invention to provide a touch panel including a transparent electrode using a metal and/or a conductive oxide, in particular A touch panel that does not have an increased substrate thickness and poor visibility.

In addition, another object of the present invention is to provide a capacitive touch panel in which a contact area between a driving electrode and a sensing electrode is increased, thereby enhancing mutual capacitance but reducing RC time, and finally enhancing driving capability.

To achieve the above objective, the present invention provides a capacitive touch panel including a first electrode and a second electrode, the first electrode and the second electrode intersecting in different directions on a single substrate, wherein the first electrode passes through Arranged such that a plurality of diamond unit cells are connected by a connection grid, each diamond unit cell consisting of a plurality of diamond cell grids, and the second electrode is configured such that a plurality of diamond unit cells are in the same The intersections of the electrodes are separated and connected by a grid bridge, each diamond unit cell consisting of a plurality of diamond cell grids.

In the touch panel of the present invention, the mesh bridge of the second electrode may be formed through unit cells of the first electrode adjacent thereto, and the number of the mesh bridges may be 1 or more.

Furthermore, the touch panel of the present invention may further comprise one or more mesh bridges for connecting unit cells of the first electrode, wherein the mesh bridge may be formed through a unit of the second electrode adjacent thereto Single cell.

Further, the present invention provides a display device including the touch panel as described above.

According to the present invention, a capacitive touch panel includes a first electrode and a second electrode formed using a metal and/or a conductive oxide, thereby improving visibility and increasing transmittance.

Further, according to the present invention, the electrodes are provided in the form of a mesh structure, thereby lowering the resistance value and increasing the contact area between the electrodes, ultimately increasing the mutual capacitance and reducing the influence of external noise.

According to the present invention, the capacitive touch panel is configured such that the first electrode and the second electrode are formed on a single layer, thereby reducing the thickness of the substrate and simplifying the manufacturing process.

Therefore, such a touch panel can be effectively applied to a large-area display device.

1‧‧‧Drive electrode / first electrode

2‧‧‧Connected Grid

3‧‧‧Sensing electrode / second electrode

4‧‧‧Grid Bridge

5‧‧‧Grid Bridge

10‧‧‧Unit Grid

20‧‧‧ unit cell

x‧‧‧Width

Y‧‧‧ Length

A‧‧‧one length

B‧‧‧ inside corner

X‧‧‧Width

Figure 1 illustrates a conventional single layer electrode pattern.

2 schematically illustrates a grid pattern for an electrode of a capacitive touch panel in accordance with the present invention.

Figure 3 illustrates a first electrode and a second electrode that intersect each other in accordance with the present invention. Extreme part.

4 illustrates a cell grid in accordance with the present invention in which one side has a length a, an inner angle b, a width x, and a length y.

Figure 5 schematically illustrates a unit cell comprising a cell grid in accordance with the present invention.

6 through 11 illustrate examples of metal mesh patterns for electrodes in accordance with the present invention.

Fig. 12 illustrates an example 1 of the present invention in which a first electrode and a second electrode made of a metal mesh intersect by a connection mesh.

Fig. 13 illustrates an example 3 of the present invention in which a first electrode and a second electrode made of a metal mesh are intersected by a connection mesh, and a mesh bridge is further provided.

FIG. 14 illustrates a series of programs for forming a touch panel in accordance with an embodiment of the present invention.

According to the present invention, a capacitive touch panel includes a first electrode and a second electrode, the first electrode and the second electrode being in different directions on a single substrate Intersecting, wherein the first electrode is configured such that a plurality of diamond unit cells are connected by a connection grid, each diamond unit cell consisting of a plurality of diamond cell grids, and the second electrode is configured to cause a plurality of The diamond unit cells are separated at the intersection with the first electrode and connected by a grid bridge, each diamond unit cell consisting of a plurality of diamond cell grids.

In the capacitive touch panel according to the present invention, the first electrode can be used as a driving electrode. Thus, the second electrode can be used as a sensing electrode. Alternatively, the first electrode may be a sensing electrode and the second electrode may be a driving electrode.

The touch panel according to the present invention is a mutual capacitive touch panel of a type that measures the touch point of the user depending on a change in capacitance occurring between the sensing electrode and the driving electrode when a voltage is applied to the driving electrode.

Hereinafter, the description of the present invention, in which the first electrode is the driving electrode and the second electrode is the sensing electrode, but the case where the first electrode is the sensing electrode and the second electrode is the driving electrode is not excluded from the scope of the present invention.

In the following, a detailed description of embodiments of the invention will be given with reference to the accompanying drawings. Detailed descriptions of the known configurations and functions will be omitted when the present invention is not described in the following description.

The following description and the accompanying drawings are intended to be familiar to those skilled in the art. Particular embodiments of the use of systems and methods. Other embodiments may include structural or logical modifications. Unless explicitly required, a single element and function can be selected and the order of the program can be changed. Portions and features of some embodiments may be included in other embodiments or substituted by other embodiments.

As shown in FIGS. 2 and 3, the drive electrode 1 is configured such that a plurality of diamond unit cells 20 composed of a plurality of diamond cell grids 10 are connected by means of a connection grid 2.

The drive electrodes 1 are formed in a lattice structure on the same surface on which the sensing electrodes 3 are formed, and are disposed to intersect the sensing electrodes. The drive electrode 1 is connected to a voltage source by wiring. When a voltage is applied to the drive electrodes, an electric field is generated between the drive electrodes and the sense electrodes.

The cell grids 10 included in the cell unit 20 of the drive electrode 1 or the sense electrode 3 may be provided in the same form and may be configured such that each of such cell grids and another adjacent cell network The cells 10 are in contact with each other to be symmetrical with respect to the adjacent cell grid 10 with respect to a corner between the cell grids 10, or to have the same side as the adjacent cell grid 10, thereby allowing current to flow therethrough. .

The sensing electrode 3 functions in sensing the touch of the user and is formed to have a mesh structure on one surface of the transparent substrate. The sensing electrode 3 is configured such that a plurality of diamonds consisting of a plurality of diamond cell grids The unit cells are separated at the intersection with the drive electrodes 1 and connected by a mesh bridge 5. Grid bridges are illustrated in Figures 9 and 10.

In accordance with the present invention, the drive and sense electrodes are provided in the form of a grid structure comprising patterned lines. When the thickness and width of the patterned line are finely controlled to about several μm, the aperture ratio (the ratio of the total area to the area different from the area containing the patterned line) can be 95 to 99.5%. When the aperture ratio of the mesh structure is increased in this manner, the transmittance of the touch panel (ratio of transmitted light to incident light) can be increased, and visibility can be improved.

According to the present invention, the driving electrode and the sensing electrode are provided so as to have a mesh structure, and accordingly, the region (the region containing the patterned line) is small, and the surface resistance is low, thereby increasing the touch feeling of the touch panel. The rate is measured to further achieve low power consumption.

Preferably, the width of the grid is 1 to 10 μm, and more preferably 1 to 5 μm.

As shown in FIG. 2 and FIG. 3, the grid bridge 5 of the sensing electrode 3 of the touch panel according to the present invention can be formed through the unit cell 20 of the driving electrode 1 adjacent thereto, and the grid bridge The number can be 1 or greater.

Furthermore, the touch panel according to the present invention may further include one or more mesh bridges 4 for connecting the unit cell 20 of the drive electrode 1, and the mesh bridge may be formed to pass through the sensing adjacent thereto Electrode unit Cell.

When the grid bridge is further provided in this manner, the reduction in the contact area between the electrodes forming the sensing electrode and the driving electrode on the single layer can be prevented, and thus the reduction in the mutual capacitance generated can be prevented. Specifically, the sensing electrode and the driving electrode are provided in the form of a grid structure, and the grid bridges of the driving electrodes and the grid bridges of the sensing electrodes are respectively formed through the sensing electrodes and have a grid structure. The unit cell and the unit cell of the drive electrode having a lattice structure, thereby reducing the resistance and increasing the contact area between the sensing electrode and the driving electrode to thereby enhance the mutual capacitance. Ultimately, reduce the impact of external noise. In addition, the RC time is reduced, thus enhancing the driving capability.

In an embodiment of the present invention, as illustrated in FIG. 4, the cell grid of the sensing electrode, the cell grid of the driving electrode, and/or the connecting grid of the sensing electrodes may have a diamond shape, wherein the length of one side of the diamond shape Is a and the inner angle is b (width: x, length: y). In the present invention, unit cells (width: X, length: Y; as shown in FIG. 5) may be configured such that the cell grids are symmetrically disposed in the vertical and horizontal directions. The dimensions of the cell grid and the dimensions of the unit cell are as follows:

X=nx

Y=ny

Where n is the number of cell grids that make up the unit cell.

In a cell grid, the ratio of x to y can be equal to 1:1~1:2.

The inner angle b is preferably from 45 to 135.

The intersection angle of the sensing electrode and the driving electrode may fall within the range of b, and b is the angle of the cell grid.

The number of mesh bridges 4 of the drive electrodes and the number of mesh bridges 5 of the sensing electrodes may be 1 or 2 or more. Moreover, such a mesh bridge is preferably formed along the shortest path P. The shortest path P is determined by the distance between the initial point and the end point of the mesh bridge.

Figure 6 shows the distance between the drive electrodes corresponding to 3x. Thus, the shortest distance of the grid bridge of the drive electrodes is P _x = 3x (6a). Since the initial point and the end point of the mesh bridge between the sensing electrodes have a distance of 2 _y therebetween, the shortest distance of the mesh bridge of the sensing electrodes is P _y = 2y (4a).

Figure 7 shows the shortest distance P uniformly formed by the distance between the initial point and the end point of the grid bridge of the drive electrode and the sense electrode.

P _x = 3x = 6a

P _y = 4y = 8a

In FIGS. 6 to 11, a broken line indicates a dummy pattern.

Figure 8 shows a shortest path in accordance with another embodiment of the present invention.

P _x =7x=14a

P _y =7y=14a

Figure 9 shows the various shapes of the grid bridge under the same conditions as the initial and end points of the grid bridge of the sensing electrodes.

Therefore, the distance of the mesh bridge has a value of 2a or more, which is the minimum value that the drive and sense electrodes can be electrically conductive with respect to each other. Therefore, the shortest path P _x of the mesh bridge of the drive electrode can be determined as 2a P _x m _x × 2a-4a (where m _x is the maximum number of cell grids in the cell unit of the drive electrode), and the shortest path P _y of the mesh bridge of the sensing electrode can be determined as 2a P _y m _y × 2a-4a (where my is the maximum number of cell grids in the unit cell of the sensing electrode). Thus, the shortest paths P _x and P _{y are} preferably arranged so as to be symmetrical to each other.

10 and 11 illustrate the shortest distance and maximum distance of the mesh bridge of the drive electrode (Fig. 10) and the grid bridge of the sense electrode (Fig. 11).

To ensure the shortest path, when the grid bridge of the sensing electrode passes through the inside of the driving electrode, the driving electrodes are connected by a bridge. When the grid bridges of the drive electrodes intersect the inside of the sense electrodes, the sense electrodes are preferably connected by a bridge.

To ensure RC uniformity, the sensing and driving electrodes are preferably provided in a symmetrical arrangement.

According to the present invention, the sensing electrode and the driving electrode may be formed of a metal thin film. The metal thin film may be formed of copper (Cu), aluminum (Al), gold (Au), silver (Ag), nickel (Ni), chromium (Cr), or an alloy thereof. Particularly useful are copper (Cu), aluminum (Al), gold (Au), silver (Ag) or alloys thereof having high electrical conductivity. Further, the sensing electrode and the driving electrode may be formed of a conductive oxide film. The conductive oxide film may include at least one oxide selected from the group consisting of ITO, FTO, AZO, IZO, GZO, ATO, and NTO.

The sensing electrode and the driving electrode may be provided in the form of a separate metal thin film, or may be provided in a stacked form including a metal thin film and a conductive oxide thin film, the stacked form being configured, for example, such that the metal thin film is stacked on the conductive oxide film.

The sensing electrodes and the driving electrodes in a grid structure may be formed on the transparent substrate using electroplating, sputtering or evaporation or a printing process such as screen printing, gravure printing or ink jet printing.

The bridge that forms the intersection of the sensing electrode and the driving electrode may be formed without limitation using the same method as that used to form the sensing electrode and the driving electrode.

The sensing electrode and the driving electrode may be insulated from the mesh bridge by means of an organic insulating film or an inorganic insulating film or by a process of forming a contact portion without a pattern (Fig. 3).

The organic insulating film may be a silicon-based organic insulating film or a hybrid organic insulating film, and the inorganic insulating film may be a silicon oxide-based inorganic insulating film.

In the present invention, the mesh bridge may be formed to have a coating as small as 1.5 μm or less, the cladding having a drive electrode and a sensing electrode.

Generally, when the sensing electrode and the driving electrode are formed of metal, the resulting touch panel can have poor transmittance due to opacity of the metal. However, the grid structure of the present invention is configured to finely pattern the line width and thickness to a few μm, thereby increasing the aperture ratio, thereby improving the transmittance of the touch panel. The sensing electrode and the driving electrode are formed of a metal having high electrical conductivity, and thus have a surface resistance of 150 Ω/□ or less, thereby exhibiting high electrical conductivity. In addition, the formation of the grid structure can increase the transmittance of the touch panel to 89% or more, resulting in high visibility.

According to the present invention, the touch panel is configured such that the sensing electrodes and the driving electrodes are formed on a single layer instead of being conventionally formed on two corresponding transparent substrates, thereby finally realizing a small touch panel. In addition, the thickness of the touch panel through which the image provided by the display passes can be reduced, thereby improving the touch panel. Visibility.

The following is a description of the process of manufacturing the touch panel according to the present invention with reference to FIG.

The touch panel according to the present invention is manufactured by the following steps: 1) forming a first oxide film and a first metal film on a transparent substrate; 2) applying a photoresist (PR) on the first metal film and using a mesh a light mask of the grid pattern exposes the photoresist; 3) developing the photoresist and etching the first metal film and the first oxide film using a wet etching solution or a dry etching process, thereby forming a first oxide film and a first metal pattern; 4) forming an inorganic or organic insulating film on the first metal pattern; 5) applying a photoresist (PR) on the insulating film and exposing the photoresist using a light mask having a hole pattern; 6) Etching the insulating film using a wet etching solution or a dry etching process, thereby forming a connection hole; 7) forming a second oxide film and a second metal film on the insulating film; 8) applying a photoresist on the second metal film (PR) and exposing the photoresist using a light mask having a grid bridge pattern; 9) developing the photoresist and etching the second metal film and the second oxide film using a wet etching solution or a dry etching process So shaped The second oxide film and a second bridge mesh pattern; and 10) is formed on the second mesh pattern bridge an inorganic or organic insulating film.

The invention is better understood by the following examples, which are illustrated to illustrate the invention but are not to be construed as limiting the invention. It will be appreciated by those skilled in the art that various modifications or improvements are possible without departing from the spirit of the invention. Accordingly, the invention is susceptible to modifications and variations within the scope of the invention as defined by the appended claims.

Example 1

As fabricated by the following method, the substrate (Fig. 8) is patterned such that the number of cell grids in the unit cell is m _x = 20 and m _y = 10, and the cell unit cell of the driving electrode is connected by a grid Connected, and the unit cells of the sensing electrodes are connected by a single grid bridge.

The substrate having the sensing electrode and the driving electrode is manufactured by the following steps: 1) forming a first oxide film (ITO or IZO) and a first metal film (alloy of Mo and Ag) on the transparent substrate; 2) a photoresist (PR) is applied on the first metal film and the photoresist is exposed using a light mask having a grid pattern; 3) the photoresist is developed and the first metal film is etched using a wet etching solution and first An oxide film, thus forming a first oxide film and a first metal pattern; 4) forming an inorganic insulating film (SiO ₂ ) on the first metal pattern; 5) applying a photoresist (PR) on the insulating film and using a light mask of the hole pattern exposes the photoresist; 6) a dry etching process is used to etch the insulating film, thereby forming a connection hole; 7) forming a second oxide film and a second metal film on the insulating film; 8) a photoresist (PR) is applied to the second metal film and the photoresist is exposed using a light mask having a grid bridge pattern; 9) the photoresist is developed and the second metal film is etched using a wet etching solution and a dioxide film, thus forming a second oxide film And a second grid bridge pattern; and 10) forming an inorganic or organic insulating film on the second grid bridge pattern.

Example 2 to Example 5

The substrate was fabricated in the same manner as in Example 1, and the substrate was configured such that the driving electrodes and the sensing electrodes were connected by a plurality of mesh bridges.

Test case

The resistance and mutual capacitance of the substrates of Examples 1 through 5 were measured depending on the grid bridge path. These results are given in Table 1 below. Thus, when the mesh bridge path is further provided in the unit cell, the resistance of the unit cell decreases and the mutual capacitance increases. In Example 4 and Example 5, compared with Example 3, since the grid bridge path was added, the RC time increased although the resistance decreased but the mutual capacitance increased.

1‧‧‧Drive electrode / first electrode

2‧‧‧Connected Grid

3‧‧‧Sensing electrode / second electrode

4‧‧‧Grid Bridge

5‧‧‧Grid Bridge

10‧‧‧Unit Grid

20‧‧‧ unit cell

Claims (14)

A capacitive touch panel includes a first electrode and a second electrode, the first electrode and the second electrode intersecting in different directions on a single substrate, the first electrode being configured to have a plurality of diamonds The unit cells are connected by a connection grid, each diamond unit cell is composed of a plurality of diamond cell grids, and the second electrode is configured such that a plurality of diamond unit cells are separated at the intersection with the first electrode Open and connected by a grid bridge, each diamond unit cell consists of a plurality of diamond cell grids. The capacitive touch panel of claim 1, wherein the grid bridges of the second electrode are formed through the unit cells of the first electrode adjacent thereto, and the grid bridges The number of pieces is 1 or more. The capacitive touch panel of claim 2, further comprising one or more mesh bridges for connecting the unit cells of the first electrode, wherein the mesh bridges are formed through The unit cells of the second electrode adjacent thereto. The capacitive touch panel of claim 1, wherein when the length of one of the cell grids is a and the inner angle of one of the cell grids is b, the inner angle b ranges from 45°. To 135°. The capacitive touch panel of claim 4, wherein when one of the cell grids has a width x and one of the cell grids has a length y, the first electrode of the grid bridges A shortest path P _x is 2a P _x m _x × 2a-4a, and a shortest path P _y of the grid bridges of the second electrode is 2a P _y m _y × 2a-4a, where m _x and m _{y are} each the maximum number of such cell grids of the unit cells. The capacitive touch panel of claim 1, wherein the first electrode and the second electrode are formed by a metal film. The capacitive touch panel according to claim 6, wherein the metal thin film comprises copper (Cu), aluminum (Al), gold (Au), silver (Ag), nickel (Ni), chromium (Cr) or an alloy thereof. . The capacitive touch panel of claim 1, wherein the first electrode and the second electrode are formed of a conductive oxide film. The capacitive touch panel of claim 1, wherein the first electrode and the second electrode are configured such that a metal thin film is stacked on a conductive oxide film. The capacitive touch panel of claim 1, wherein the first electrode and the second electrode are insulated from the mesh bridge by a germanium-based organic insulating film or a hybrid organic insulating film. The capacitive touch panel of claim 1, wherein the first electrode and the second electrode are insulated from the mesh bridge by an inorganic insulating film based on cerium oxide. The capacitive touch panel of claim 1, wherein the first electrode is a driving electrode and the second electrode is a sensing electrode, or the first electrode is a sensing electrode and the second electrode is a Drive the electrode. The capacitive touch panel of claim 1, wherein the mesh bridges have a cladding layer of 1.5 μm or less, the cladding layer having the first electrode and the second electrode. A display device comprising the capacitive touch panel as claimed in claim 1.