KR20120072174A - Touch panel - Google Patents

Abstract

PURPOSE: A touch panel which forms an electrode having an upper/lower substrate in a two-layered or a three-layered structure is provided to reduce surface resistance of an electrode having a single layer structure by forming an electrode in a two-layered or a three-layered structure. CONSTITUTION: A pair of transparent electrodes(115,155) is formed in order to be opposite to a pair of transparent substrates. Interconnection electrodes(120,160) are formed in order to be crossed with sides on the transparent electrodes. A bonding layer(180) covers the interconnection electrode. The transparent electrode has a multiple-layer structure by including a first layer and a second layer.

Description

Touch panel {Touch panel}

The present invention relates to a touch panel, and more particularly to a touch panel having a transparent electrode of low resistance characteristics.

The touch panel, which is an integrated display device, is a means for inputting a user-specified command or graphic information by generating a voltage or current signal corresponding to a position where a stylus pen or a finger is pressed.

Recently, a touch panel is attached to a display device and a product having a function of operating by touching a screen, for example, a mobile phone, a PDA, or a notebook, has been commercialized.

The touch panel is divided into a resistive type and a capacitive type according to the principle of operation. The resistive type touch panel has two plate type electrodes pressed by a user while voltage is applied to two opposing plate type electrodes. The voltage or current change at the contact point generated by this contact is read and converted into coordinate values.

In addition, the capacitive touch panel is provided with a plate-shaped electrode on each of the upper and lower substrates, and a stylus pen or a finger and a plate, which are pen-type input devices, at a contact point pressed by the user while the charge and discharge states of the capacitance are repeated. By accumulating a small amount of charge in accordance with the capacitive coupling of the type of electrode, the change in parasitic capacitance is sensed as a change in the amount of current in the electrode and read and converted into coordinate values.

On the other hand, the touch panel having the two methods is attached to the display device, so that the user should look at the image coming from the display device to operate the transparent characteristics should be given.

Therefore, the plate-shaped electrode provided on both the upper substrate and the lower substrate of the touch panel is made of a transparent conductive material.

On the other hand, since the touch panel must sense a change in parasitic capacitance that is changed by contacting a user's finger or stylus pen using an electrode made of a transparent conductive material provided therein, the internal resistance of the plate-shaped electrode is a very important factor. It is becoming.

In the case of the conventional touch panel, the plate-shaped electrode having transparent characteristics has a single film structure as indium tin oxide (ITO) or indium zinc oxide (IZO), which is a transparent conductive material.

At this time, each electrode having the structure of the single layer has a very large resistance dependence according to its thickness, and the plate-shaped electrode made of a single-layer structure made of a transparent conductive material has a sheet resistance of about 20 kW / kW at 1500 kW. . When the thickness of the plate-shaped electrode is increased, the sheet resistance is reduced, but the transmittance is sharply lowered, which lowers the display quality of the display device.

However, when a plate-shaped electrode made of a transparent conductive conductive material having a sheet resistance of about 20 kW / ㅁ at a thickness of about 1500 kW is provided in a large area touch panel of 10 "or larger, the touch sensitivity is drastically reduced by the sheet resistance of the electrode. have.

Therefore, in order to have a smooth touch sensitivity in a touch panel having a large area of 10 "or more, it is required that the plate-shaped electrodes provided on the inner surface of both substrates have a sheet resistance of at least 10 kW / kW.

In order to solve the above problems, an object of the present invention is to provide a touch panel having excellent touch sensitivity even when the electrode in the touch panel maintains a transparent characteristic and has a low resistance characteristic even when implementing a large area of 10 "or more.

Touch panel according to the present invention for achieving the above object, a pair of transparent substrate facing each other; A pair of transparent electrodes formed to face each other on an inner surface of the pair of transparent substrates; Wiring electrodes formed on the transparent electrodes to cross each other on a pair of side surfaces facing each other; An adhesive layer covering the wiring electrode and formed of an insulating material and adhering the two substrates facing each other, wherein each transparent electrode includes a first layer made of a transparent conductive material and a second layer made of a low resistance metal material. It is characterized by having a multi-layer structure formed.

In this case, each of the transparent electrodes may further include a third layer covering the second layer and made of a transparent conductive material to form a triple layer structure.

In addition, the transparent conductive material is indium tin oxide (ITO) or indium zinc oxide (IZO), and the low resistance metal material is gold (Au), silver (Ag), aluminum (Al), copper (Cu). ) Is any one of the features.

In addition, each of the transparent electrodes has a sheet resistance of 10 kW / W or less, and an average transmittance of visible light is 80% or more.

In addition, each of the transparent electrodes is characterized in that the thickness ratio of the layer made of the transparent conductive material and the layer made of the low resistance metal material is 1: 0.25 to 1: 0.75.

Further, in each of the transparent electrodes, the layer made of the transparent conductive material has a thickness of 100 kPa to 1500 kPa, and the layer made of the low resistance metal material has a thickness of 50 kPa to 200 kPa.

In addition, the first transparent electrode is provided with a plurality of spacers spaced apart a predetermined interval, the adhesive layer is characterized in that the role of the insulating layer by being formed between the first transparent electrode and the second transparent electrode.

In addition, any one of the transparent substrates facing each other is a display device.

In the touch panel according to the present invention, since the electrodes provided on each of the upper and lower substrates have a double layer or triple layer structure, the sheet resistance is lower than that of the electrode having a single layer structure using a conventional transparent conductive material, and the microcavity effect inside the electrode. Is implemented, the light transmittance is similar to the electrode of a single film to achieve a large area of 10 "or more has the advantage of excellent touch sensitivity.

1A and 1B are cross-sectional views of a touch panel according to an embodiment of the present invention, respectively.
2 is a cross-sectional view of a touch recognition display device with a touch panel according to a modification of the present invention.

Hereinafter, preferred embodiments according to the present invention will be described with reference to the drawings.

1A and 1B are cross-sectional views of a touch panel according to an exemplary embodiment of the present invention, respectively. FIG. 1A shows the first and second transparent electrodes having a triple layer structure, and FIG. 1B shows the first and second transparent electrodes. The thing which has this double layer structure was shown, respectively.

The touch panel 100 according to an embodiment of the present invention includes a lower substrate 110 and an upper substrate 150, a first transparent electrode 115 and an upper substrate formed on an inner surface of the lower substrate 110. The second transparent electrode 155 formed on the inner surface of the 150 and the spacers (not shown) formed at regular intervals between the first and second transparent electrodes 115 and 155 are formed. In this case, the spacer (not shown) is formed when the touch panel 100 is operated in a resistive manner, and may be omitted when operating in a capacitive manner.

In the touch panel 100 having such a configuration, first wiring electrodes 120 are formed on the edges of both sides of the first transparent electrode 115 that face each other and have a wiring form extending in a first direction. .

In addition, a second wiring electrode 160 is formed on the edges of both sides of the lower portion of the second transparent electrode 155 that face each other and extend in a second direction perpendicular to the first direction.

In this case, the first and second wiring electrodes 120 and 160 may be formed of low-resistance metal materials such as aluminum (Al), aluminum alloy (AlNd), copper (Cu), copper alloy, silver (Ag), and gold ( Au).

Meanwhile, the upper and lower substrates 150 and 110 may be made of a transparent glass substrate or a flexible plastic substrate, and may also be made of a polymer film having insulation properties, for example, polyethylene terephthalate (PET).

In addition, the touch panel 100 having the above-described configuration includes a lower substrate 110 having the first transparent electrode 115 and the first wiring electrode, the second transparent electrode 155, and the second wiring electrode 160. An adhesive layer 180 for bonding the provided upper substrate 150 is provided. In this case, when the touch panel 100 is used as a resistive film, the adhesive layer 180 covers each of the wiring electrodes 120 and 160 in correspondence with the first and second wiring electrodes 120 and 160. When the touch panel 110 is used in a capacitive manner, the adhesive layer 180 includes the first and second wiring electrodes 120 and 160, and the first and second transparent electrodes 115. , 155 may be formed on the entire display area.

The adhesive layer 180 not only serves to maintain the panel state by adhering the lower and upper substrates 150, but also serves as an insulating layer that insulates the first and second wiring electrodes 120 and 160 from each other. It is characteristic.

When the touch panel 100 having such a configuration operates in a resistive manner, when the outer surface of the upper substrate 150 is pressed by a stylus pen or a user's finger, the second wiring electrode 160 is connected to the first electrode. By short-circuit with the wiring electrode 120, a signal having a current amount or a voltage level that varies depending on the pressed position is generated, it is possible to detect the position of the touched portion based on the signal.

That is, when a specific point of the outer surface of the upper substrate 150 is touched, each of the transparent electrodes 115, up, down, left and right in proportion to the position from the first and second wiring electrodes 120 and 160 155) Since the resistance value is confirmed, the coordinates of the touched portion on the plane are calculated by calculating based on this, so that the position of the touched portion can be detected.

Alternatively, in the case of the capacitive type, when the user's finger or the like is touched, the second transparent electrode 155 provided on the inner surface of the upper substrate 150 by the finger touch and the parasitic capacitance generated by the finger are used for the first. And by checking the capacitance change formed between the second transparent electrodes 115 and 155 and calculating it based on this, the coordinates of the touched portion are calculated on the plane to detect the position of the touched portion.

The touch panel 100 having the configuration as described above is touched when the sheet resistance of the first and second transparent electrodes 115 and 155 formed on the inner surfaces of the upper substrate 150 and the lower substrate 110 is large. Since the precision of detection falls, it is preferable to make this sheet resistance into 10 kW / W or less.

Therefore, in the touch panel 100 according to the embodiment of the present invention, the sheet resistance of the first and second transparent electrodes 115 and 155 is 10 kW / W in order to suppress a decrease in touch sensitivity even when a large area of 10 "or more is increased. It is characterized by being formed to be as follows.

That is, as shown in FIG. 1B, the first and second transparent electrodes 115 and 155 formed on the inner surfaces of the upper substrate 150 and the lower substrate 110 are formed of a low resistance metal material / transparent conductive material or It is characterized by forming a double layer structure made of a transparent conductive material / low resistance metal material, or having a triple layer structure made of a transparent conductive material / low resistance metal material / transparent conductive material as shown in FIG. 1A.

In this case, the transparent conductive material is indium tin oxide (ITO) or indium zinc oxide (IZO), and the low resistance metal material is copper (Cu), aluminum (Al), gold (Au), silver (Ag). ) To any one.

As such, the first and second transparent electrodes 115 and 155 form a double layer (see FIG. 1B) or a triple layer (see FIG. 1A), thereby reducing sheet resistance compared to a transparent electrode having a single layer structure using a conventional transparent conductive material. It is characteristic.

Further, the first and second transparent electrodes 115 and 155 may have a double layer or triple layer structure by interposing a layer made of a low resistance metal material, but the layers 115a, 115c, 155a, and 155c made of a transparent conductive material. By controlling the appropriate thickness of the layers (115b, 155b) made of a low-resistance metal material is characterized in that the transmittance of light compared to the conventional transparent electrode having a single layer structure of a transparent conductive material.

Despite having a double layer or triple layer structure including a layer of a low resistance metal material, a double layer has a transmittance similar to that of a conventional transparent electrode having a single layer structure as a transparent conductive material (see FIG. 1B). Alternatively, the microcavity effect and the surface plasmon effect may be expressed in the first and second transparent electrodes 115 and 155 having the triple layer (see FIG. 1A) structure.

The micro cavity effect is that light repeatedly reflects inside a specific material layer, and when specific conditions are satisfied, the light can be temporarily reflected to improve light transmission efficiency. In this case, in order to implement such a micro cavity effect, a structure having a double layer or more having different reflectances must be formed.

Surface plasmons, on the other hand, are collective charge density oscillations of electrons that occur on the metal thin film surface. The surface plasmon is generated from a specific metal, that is, a metal having a negative dielectric constant, which is easy to emit electrons by an external stimulus, and the metal that generates the surface plasmon is, for example, copper (Cu). ), Aluminum (Al), gold (Au), silver (Ag) and the like.

Plasmons move in a group when light is incident from the outside, and emit light when they meet specific conditions. The transmittance of is improved.

Accordingly, the touch panel 100 according to the present invention forms the first and second transparent electrodes 115 and 155 in a double layer or triple layer structure so that the microcavity effect and the surface plasmon expression can be achieved. This can improve the transmittance.

More specifically, the configuration of the first and second transparent electrodes 115 and 155 will be described.

In the touch panel 100 according to the present invention, as shown in FIG. 1A, when the first and second transparent electrodes 115 and 155 each form a triple layer, a lower layer made of a transparent conductive material having a first thickness, respectively. 115a and 155a, intermediate layers 115b and 155b made of the low-resistance metal material described above having a second thickness, and upper layers 115c and 155c made of a transparent conductive material having a third thickness.

In addition, as shown in FIG. 1B, when the first and second transparent electrodes 115 and 155 have a double layer structure, the first layers 115a and 155a made of a transparent conductive material having a first thickness, and the second The second layers 115b and 155b made of the above-described low resistance metal material having a thickness are formed.

Meanwhile, in the drawing, the first and second transparent electrodes 115 and 155 are respectively formed of the first layers 115a and 155a made of a transparent conductive material and the second layers 115b and 155b made of the low resistance metal material described above. It is apparent that the first layer (115a, 155a) is made of a low-resistance metal material and the second layer (115b, 155b) may be made of a transparent conductive material.

In this case, the thicknesses of the layers 115a, 115c, 155a, and 155c made of a transparent conductive material and the layers 115b and 155b made of a low resistance metal material may be formed to have a thickness ratio of about 1: 0.25 to 1: 0.75. .

That is, the layers 115a, 115c, 155a, and 155c made of a transparent conductive material are formed to have a greater thickness than the thicknesses of the layers 115b and 155b made of a low resistance metal material.

In this case, the first and third thicknesses of the layers 115a, 115c, 155a, and 155c made of a transparent conductive material are formed to be about 100 kPa to about 1500 kPa, and the first and third layers of the layers 115b and 155b made of a low resistance metal material. 2 It is preferable to form thickness so that it may become about 50 micrometers-200 micrometers.

The first and second transparent electrodes 115 and 155 having such a thickness and having a double layer or triple replenishment structure have a sheet resistance of 10 kW / W or less and an average transmittance of light of 80% or more.

Table 1 shows the measurement of the transmittance and sheet resistance of light of the transparent electrode having a single layer structure as a transparent conductive material and a transparent electrode having a triple layer structure according to an embodiment of the present invention. In this case, the transparent conductive material constituting the transparent electrode is represented by using indium-zinc-oxide (IZO), and the low-resistance metal material is silver (Ag) as an example. The thickness of each of the upper layers was 400 kPa, and in the case of the comparative example, a transparent electrode having a single layer structure was formed to have a thickness of 800 kPa.

Example (IZO (400 kPa) / Ag / IZO (400 kPa)) Comparative example Ag thickness IZO alone
(800 yen) 100Å 120Å 140Å 160Å 180Å 200Å
Transmittance
(%) 470 nm 79.6 79 85.8 79.4 76.3 73.7 83.9 550 nm 66.2 64.9 84.3 75.3 74.6 73.1 81.9 630 nm 47.8 53.6 75 64.4 67.2 54.9 83.1 Sheet resistance (Ω / □) 19.7 6.3 3.3 2.9 2.3 1.9 53.6

Referring to Table 1, when the thickness of the upper layer and the lower layer made of indium-zinc-oxide (IZO) is 400 kPa, the intermediate layer made of the low resistance metal material is formed to have a thickness of 120 kPa or more. It can be seen that the sheet resistance is 6.3 kW / W or less.

In this case, it can be seen that the transmittance of the light in the wavelength bands of 630 nm, 550 nm, and 470 nm representing red, green, and blue changes for each thickness. For example, when the intermediate layer is formed to have a thickness of about 140 dB, the wavelength bands of 630 nm, 550 nm, and 470 nm The light transmittance is 75%, 84.3% and 85.5%, respectively, and the average transmittance is about 82%.

On the other hand, in the comparative example, the transparent electrode made of indium-zinc oxide (IZO) had a thickness of about 800 kPa as in the embodiment, and the transmittance of light at wavelengths of 630 nm, 550 nm, and 470 nm was 83.1, respectively. %, 81.9%, 83.9%, the average transmittance of about 83%, but the sheet resistance is 53.6 kW / ㅁ was found to have a value several times higher than the embodiment.

In the case of the touch panel 100 according to the embodiment of the present invention, referring to FIGS. 1A and 1B, the first and second transparent electrodes 115 may have a double layer or triple layer structure made of a transparent conductive material and a low resistance metal material. 155) significantly reduces the sheet resistance to 10 kW / W or less, and the transmittance to light has a level similar to that of a conventional touch panel having a transmissive electrode having a single layer structure of a transparent conductive material.

Therefore, in the case of the touch panel 100 according to the present invention having the above-described configuration, even if a large area of 10 " or more is realized, a decrease in touch sensitivity due to resistance of the transparent electrode does not occur.

Meanwhile, in the touch panel 100 according to the exemplary embodiment of the present invention, the first and second transparent electrodes 115 and 155 interposed between the lower and upper substrates 110 and 150 and the two substrates 110 and 150. ) And the touch panel 100 having the first and second wiring electrodes 120 and 160 provided in the form of crossing the inner surfaces of the first and second transparent electrodes 115 and 155, respectively. It is apparent that the present invention is not limited to these embodiments and can be variously modified.

As an example, as shown in FIG. 2 (sectional view of a touch recognition display device with a touch panel according to a modification of the present invention), the display device 200 according to a modification of the present invention is attached thereto. For example, a liquid crystal panel 300 or an organic light emitting diode (not shown) including an array substrate 210 having an array element, a color filter substrate 250 having a color filter layer, and a liquid crystal layer 280. It may be formed using an organic light emitting device (not shown) including a first substrate (not shown) having a) and a second substrate (not shown) for encapsulation as a single substrate.

In this case, the first wiring electrode 120 is formed on the outer surface of the display device 300 in the form of a wiring at both edges facing the first transparent electrode 115, and the first transparent electrode 115 A second wiring electrode formed on the second transparent electrode 155 in a direction crossing the second transparent electrode 155 and the first wiring electrode 160 on the inner surface of the transparent substrate 450 facing each other ( The touch panel 200 may be configured by providing the 160 and the adhesive layer 180.

Also in the case of the touch panel 200 according to a modification having such a configuration, the first transparent electrode 115 and the second transparent electrode 155 may have a transparent conductive material and a low resistance metal with an appropriate thickness as in the above-described embodiment. By forming a double layer or triple layer structure made of a material, the sheet resistance of the first and second transparent electrodes 115 and 155 may be 10 kW / W or less.

100: touch panel
110: lower substrate
115: first transparent electrode
115a, 115b, 115c: lower layer, middle layer, upper layer (of the first transparent electrode)
120: first wiring electrode
150: upper substrate
155: second transparent electrode
155a, 155b, 155c: lower layer, middle layer, upper layer (of the second transparent electrode)
160: second wiring electrode
180: adhesive layer

Claims (9)

A pair of transparent substrates facing each other;
A pair of transparent electrodes formed to face each other on an inner surface of the pair of transparent substrates;
Wiring electrodes formed on the transparent electrodes to cross each other on a pair of side surfaces facing each other;
An adhesive layer covering the wiring electrodes and formed of an insulating material to bond the two substrates facing each other;
Wherein each of the transparent electrodes has a multilayer structure including a first layer made of a transparent conductive material and a second layer made of a low resistance metal material.
The method of claim 1,
Each of the transparent electrodes covers the second layer and further includes a third layer made of a transparent conductive material to form a triple layer structure.
The method according to claim 1 or 2,
The transparent conductive material is indium tin oxide (ITO) or indium zinc oxide (IZO),
The low resistance metal material is a touch panel, characterized in that any one of gold (Au), silver (Ag), aluminum (Al), copper (Cu).
The method of claim 3, wherein
Each of the transparent electrodes has a sheet resistance of 10 kW / W or less, and an average transmittance of visible light of 80% or more.
The method of claim 3, wherein
Each of the transparent electrodes is a touch panel, characterized in that the thickness ratio of the layer made of the transparent conductive material and the layer made of the low-resistance metal material is 1: 0.25 to 1: 0.75.
The method of claim 3, wherein
In each of the transparent electrodes, the layer of the transparent conductive material has a thickness of 100 ~ 1500Å, the layer of the low resistance metal material has a thickness of 50 ~ 200Å of the touch panel.
The method of claim 3, wherein
A touch panel provided with a plurality of spacers spaced at a predetermined interval on the first transparent electrode.
The method of claim 3, wherein
The adhesive layer is formed between the first transparent electrode and the second transparent electrode, the touch panel, characterized in that serves as an insulating layer.
The method of claim 3, wherein
And any one of the transparent substrates facing each other is a display device.

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