WO2020153621A1 - Touch sensor and image display device including same - Google Patents

Abstract

A touch sensor according to embodiments of the present invention comprises: a substrate layer; and sensing electrodes which are arranged on the substrate layer, include a laminate structure of a transparent oxide electrode layer and a metal layer, and have a predetermined optical magnification of 5 or less. A high-transmittance, low-reflection structure can be achieved through the optical magnification design of the sensing electrodes.

Description

Touch sensor and image display device including same

The present invention relates to a touch sensor and an image display device including the same. More specifically, the present invention relates to a touch sensor including a multi-layered sensing electrode and an image display device including the same.

With the recent development of information technology, the demand for the display field has been presented in various forms. For example, various flat panel display devices having characteristics such as thinning, lightening, and low power consumption, for example, a liquid crystal display device, a plasma display panel device, Electroluminescent display devices, organic light-emitting diode display devices, and the like have been studied.

On the other hand, an input device, a touch panel or a touch sensor, which is attached to the display device and allows a user to input a command by selecting an instruction displayed on the screen as a human hand or an object, is combined with a display device to display images and Electronic devices with information input functions are being developed.

In the case of the touch sensor, sensing electrodes including a conductive material such as metal for touch sensing of a user may be arranged on a substrate. When the touch sensor is inserted into the display device, the quality of the image implemented by the display device by the sensing electrode may deteriorate. For example, the sensing electrode may be viewed by the user and disturb the image. In addition, the color of the image may be changed by the sensing electrode.

Therefore, it is necessary to design the sensing electrode while maintaining predetermined conductivity and sensitivity for touch sensing while also considering optical characteristics for improving image quality.

For example, as in Korean Patent Publication No. 2014-0092366, a touch screen panel in which a touch sensor is combined with various image display devices has recently been developed, but as described above, there is a need for a touch sensor or a touch panel with improved optical characteristics. It continues.

One object of the present invention is to provide a touch sensor having improved optical and mechanical properties.

One object of the present invention is to provide an image display device including the touch sensor.

1. Substrate layer; And sensing electrodes arranged on the substrate layer and including a stacked structure of a transparent oxide electrode layer and a metal layer, and having an optical ratio of 5 or less as defined by Equation 1 below:

[Equation 1]

Optical ratio = extinction coefficient of metal layer/(|transparent oxide electrode layer refractive index-metal layer refractive index|).

2. In the above 1, the optical ratio of the sensing electrode is 3 or less, a touch sensor.

3. In the above 1, wherein the sensing electrode comprises a first transparent oxide electrode layer, the metal layer and the second transparent oxide electrode layer sequentially stacked on the base layer, a touch sensor.

4. In the above 3, the optical ratio between the metal layer and the first transparent oxide electrode layer is 5 or less, and the optical ratio between the metal layer and the second transparent oxide electrode layer is 5 or less.

5. In the above 3, the thickness of the first transparent oxide electrode layer and the second transparent oxide electrode layer is 100 to 700 Pa, respectively, and the thickness of the metal layer is 50 to 300 Pa, the touch sensor.

6. In the above 3, the thickness of the first transparent oxide electrode layer and the second transparent oxide electrode layer is 300 to 500 Pa, respectively, and the thickness of the metal layer is 70 to 150 Pa, the touch sensor.

7. In the above 3, further comprising a refractive index matching layer formed between the first transparent oxide electrode layer and the base layer, a touch sensor.

8. The touch sensor according to the above 7, wherein the refractive index matching layer has a refractive index of the base layer and a refractive index between the first transparent oxide electrode layer.

9. In the above 1, the refractive index of the transparent oxide electrode layer is 1.7 to 2.2, the touch sensor.

10. The touch sensor according to the above 1, wherein the metal layer comprises a silver (Ag) alloy.

11. The touch sensor according to the above 1, wherein the sensing electrodes include first sensing electrodes and second sensing electrodes arranged in a direction intersecting each other.

12. The touch sensor according to 11 above, wherein the second sensing electrodes are integrally connected in a column direction by a connection unit.

13. In the above 12, the first sensing electrodes are spaced apart from each other in the row direction with the connecting portion therebetween,

And a bridge electrode electrically connecting the adjacent first sensing electrodes to each other with the connection portion interposed therebetween.

14. In the above 11, the first sensing electrode and the second sensing electrode insulating layer insulating each other; And a passivation layer formed on the insulating layer,

At least one of the insulating layer or the passivation layer comprises a barrier layer or barrier structure comprising an aluminum oxide-zinc oxide (AZO) composite material, silazane, siloxane or silicon-containing inorganic material sensor.

15. The touch sensor according to 14 above, wherein the barrier structure further comprises an organic layer stacked on the barrier layer.

16. The touch sensor according to 15 above, wherein the barrier structure includes the barrier layers and the organic layers stacked alternately.

17. The touch sensor according to 14 above, wherein the barrier layer has a multilayer structure including a first barrier layer and a second barrier layer.

18. The touch sensor of 17 above, wherein the first barrier layer comprises the silicon-containing inorganic material, and the second barrier layer comprises silazane.

19. window substrate; And a touch sensor according to any one of 1 to 18 above stacked on the window substrate.

20. Display panel; And a touch sensor according to any one of the above 1 to 18 stacked on the display panel.

The touch sensor according to embodiments of the present invention includes a sensing electrode having a multi-layer structure of a transparent oxide electrode layer and a metal layer, and can implement low resistance and high transmittance together. The extinction coefficient and the refractive index between the metal layer and the transparent oxide electrode layer are adjusted to reduce light reflection generated from the sensing electrode and prevent the sensing electrode from being viewed by the user.

In some embodiments, the sensing electrode includes a three-layer structure including a first transparent oxide electrode layer-metal layer-second transparent oxide electrode layer, and further improves transmittance and corrosion resistance of the sensing electrode.

1 and 2 are schematic plan and cross-sectional views, respectively, showing a touch sensor according to example embodiments.

3 is a schematic cross-sectional view illustrating a touch sensor in accordance with some example embodiments.

4 is a schematic cross-sectional view illustrating a touch sensor in accordance with some example embodiments.

5-10 are schematic cross-sectional views illustrating a barrier structure in accordance with some example embodiments.

11 is a schematic diagram illustrating a window stack and an image display device according to example embodiments.

Embodiments of the present invention provides a touch sensor including a sensing electrode having a double layer structure of a transparent oxide electrode layer and a metal layer, and having optical properties capable of preventing electrode visibility. In addition, a window stack and an image display device including the touch sensor are provided.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the following drawings attached to this specification are intended to illustrate preferred embodiments of the present invention, and serve to further understand the technical idea of the present invention together with the contents of the present invention, the present invention is described in such drawings It should not be interpreted as being limited to the matter.

1 and 2 are schematic plan and cross-sectional views, respectively, showing a touch sensor according to example embodiments. Specifically, FIG. 2 shows a cross-sectional view at the crossing region C of FIG. 1. For example, FIGS. 1 and 2 show a mutual capacitance type touch sensor.

Referring to FIG. 1, the touch sensor may include a base layer 100 and sensing electrodes arranged on the base layer 100.

The base layer 100 is used in a sense to encompass a support layer, an interlayer insulating layer, or a film type substrate for forming the sensing electrodes 110 and 130. For example, the base layer 100 may be a film material commonly used in touch sensors without particular limitation, and may include, for example, glass, polymer, and/or inorganic insulating materials. Examples of the polymer, cyclic olefin polymer (COP), polyethylene terephthalate (PET), polyacrylate (PAR), polyetherimide (PEI), polyethylene naphthalate (PEN), polyphenylene sulfide (PPS), poly Allylate (polyallylate), polyimide (PI), cellulose acetate propionate (CAP), polyethersulfone (PES), cellulose triacetate (TAC), polycarbonate (PC), cyclic olefin copolymer (COC), poly And methyl methacrylate (PMMA). Examples of the inorganic insulating material include silicon oxide, silicon nitride, silicon oxynitride, and metal oxide.

In some embodiments, a layer or film member of the image display device into which the touch sensor is inserted may be provided as the base layer 100. For example, an encapsulation layer or a passivation layer included in the display panel may be provided as the base layer 100.

The sensing electrodes 110 and 130 may be disposed on a central region or an active region of the upper surface of the base layer 100. When a user's touch is input into the active area, a change in capacitance may occur by sensing electrodes 110 and 130. Accordingly, the physical touch is converted into an electrical signal to perform a predetermined sensing function.

The first sensing electrodes 110 and the second sensing electrodes 130 may be arranged along two different crossing directions. For example, the first sensing electrodes 110 may be arranged along the row direction (or X direction) of the upper surface of the base layer 100. The second sensing electrodes 130 may be arranged along the column direction (or Y direction) of the upper surface of the base layer 100.

The second sensing electrodes 130 neighboring along the column direction may be connected to each other by a connection unit 135. The connection portion 135 may be integrally connected to the second sensing electrodes 130 to be provided as a substantially single member.

The plurality of second sensing electrodes 130 may be integrally connected to each other by the connection unit 135 to define a second sensing electrode column. Also, a plurality of the second sensing electrode columns may be arranged along the row direction.

Each of the first sensing electrodes 110 may have an independent island pattern shape. The first sensing electrodes 110 neighboring in the row direction may be electrically connected to each other through the bridge electrode 115.

Accordingly, a first sensing electrode row including a plurality of first sensing electrodes 110 connected to each other through the bridge electrode 115 may be defined. Also, a plurality of the first sensing electrode rows may be arranged along the column direction.

Traces may be extended from each of the first sensing electrode row and the second sensing electrode column. For example, a first trace 150 may extend from each of the first sensing electrode rows, and a second trace 160 may extend from each of the second sensing electrode columns.

The distal ends of the first and second traces 150 and 160 may be aggregated into a bonding region assigned to one end of the base layer 100. The end portions may be bonded, for example, through a flexible printed circuit board (FPCB) and an anisotropic conductive film (ACF). The touch sensor driving IC chip may be electrically connected to the first and second traces 150 and 160 through the flexible printed circuit board.

The terms "column direction" and "row direction" used in this application are not used to refer to absolute directions, but are used in a relative sense to refer to two different directions intersecting. For example, in FIG. 1, the first sensing electrodes 110 may be integrally connected to each other by a connection unit, and the second sensing electrodes 130 may be connected to each other through a bridge electrode.

Referring to FIG. 2, the bridge electrode 155 and the connection portion 135 may intersect and overlap each other in the planar direction in the crossing region C indicated by the dotted circle in FIG. 1. In addition, as illustrated in FIG. 2, the bridge electrode 115 and the connection portion 135 may face each other in the thickness direction with the insulating layer 120 therebetween.

The sensing electrodes 110 and 130 may include a multilayer structure of a transparent oxide electrode layer and a metal layer, respectively. In example embodiments, the sensing electrodes 110 and 130 are respectively the first transparent oxide electrode layer 50, the metal layer 60, and the second transparent oxide electrode layer 70 sequentially stacked from the top surface of the base layer 100. ).

The first transparent oxide electrode layer 50 and the second transparent oxide electrode layer 70 are indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium zinc tin oxide (IZTO), aluminum doped zinc oxide And transparent conductive oxides such as (AZO), gallium doped zinc oxide (GZO), zinc tin oxide (ZTO), indium gallium oxide (IGO), and tin oxide (SnO ₂ ).

In some embodiments, the first transparent oxide electrode layer 50 and the second transparent oxide electrode layer 70 may include ITO or IZO.

The metal layer 60 is silver (Ag), gold (Au), copper (Cu), aluminum (Al), platinum (Pt), palladium (Pd), chromium (Cr), titanium (Ti), tungsten (W), Niobium (Nb), tantalum (Ta), vanadium (V), iron (Fe), manganese (Mn), cobalt (Co), nickel (Ni), zinc (Zn), molybdenum (Mo) or alloys thereof (e.g. For example, silver-palladium-copper (APC). These may be used alone or in combination of two or more.

In exemplary embodiments, the metal layer 60 includes a material that satisfies an optical ratio range described later, and may preferably include a silver alloy such as APC.

As described above, the sensing layer resistance of the touch sensor may be reduced by including the metal layer 60 in the sensing electrodes 110 and 130. In addition, the flexibility of the touch sensor is secured through the metal layer 60 to be applied to the flexible display to prevent damage to the sensing electrodes 110 and 130 even when repeated folding and folding are applied.

Transparent oxide electrode layers 50 and 70 having relatively improved chemical resistance are disposed on the upper and lower surfaces of the metal layer 60 to prevent external moisture, air penetration, oxidation, and corrosion of the metal layer 60. . In addition, the transmittance of the sensing electrodes 110 and 130 is improved by the transparent oxide electrode layers 50 and 70 to prevent electrode visibility.

According to exemplary embodiments, the refractive indexes of the transparent oxide electrode layers 50 and 70 may be adjusted in the range of about 1.7 to 2.2 to reduce reflection through matching the refractive index with the metal layer 60. For example, in the case of ITO, the refractive index may be adjusted through a sputtering process using a target in which the weight ratio of indium oxide (In ₂ O ₃ ) and tin oxide (SnO ₂ ) is adjusted.

According to exemplary embodiments, the ratio of the extinction coefficient of the metal layer to the difference in refractive index of the metal layer and the transparent oxide electrode layer (hereinafter referred to as an optical ratio) may be 5 or less (expressed in Equation 1 below). For example, the optical ratio may range from about 1 to 5.

[Equation 1]

Optical ratio = extinction coefficient of metal layer/(|refractive index of transparent oxide electrode layer-refractive index of metal layer|)

When Equation 1 is satisfied, the reflectance at the sensing electrodes 110 and 130 is reduced, and the transmittance can be significantly increased. In one preferred embodiment, preferably, the optical ratio may be about 3 or less (eg, 1 to 3).

The extinction coefficient is an index indicating the intensity of light per unit path in the metal layer and can be obtained by the equations 1 and 2 below.

[Equation 1]

I = I ₀ e ^(-αT)

In Equation 1, α is the absorption coefficient, T is the thickness, I ₀ is the intensity of light before transmission, and I is the intensity of light after transmission.

[Equation 2]

α = 4πk/λ ₀

In Equation 2, α is an absorption coefficient, k is an extinction coefficient, and λ ₀ is a wavelength of light.

When the optical ratio range of Equation 1 is satisfied, the electrode visibility due to light reflection can be effectively suppressed while preventing excessive disappearance of the transmitted light of the sensing electrodes 110 and 130.

In example embodiments, the optical ratio between the metal layer 60 and the first transparent oxide electrode layer 50 is 5 or less, and the optical ratio between the metal layer 60 and the second transparent oxide electrode layer 70 is 5 or less. Can.

The metal layer 60 may be formed to have a thickness smaller than each of the first and second transparent oxide electrode layers 50 and 70 to improve transmittance.

In some embodiments, the thickness of each of the first and second transparent oxide electrode layers 50 and 70 may be about 100 to 700 mm 2, preferably about 300 to 500 mm 2. In some embodiments, the thickness of the metal layer 60 may be about 50 to 300 mm 2, preferably about 70 to 150 mm 2.

Within the thickness range, the effect of suppressing the reflectance and improving the transmittance can be realized more effectively in combination with the value of Equation 1 above.

Referring back to FIG. 2, the bridge electrode 115 may electrically connect neighboring first sensing electrodes 110 to each other on the insulating layer 120.

For example, the bridge electrode 115 may include a contact portion penetrating the insulating layer 120 and contacting the second transparent oxide electrode layer 70 included in the first sensing electrode 110.

The bridge electrode 115 may include the above-described transparent conductive oxide and/or low resistance metal. In some embodiments, to prevent an increase in channel resistance through the bridge electrode 115, the bridge electrode 115 may include a metal layer. In one embodiment, the bridge electrode 115 may also have a multilayer structure of a metal layer and a transparent oxide electrode layer.

The passivation layer 140 may be formed on the insulating layer 120 to cover the bridge electrode 115. The insulating layer 120 and the passivation layer 140 may include organic insulating materials such as siloxane-based resins and acrylic resins, or inorganic insulating materials such as silicon oxide, silicon nitride, and silicon oxynitride.

3 is a schematic cross-sectional view illustrating a touch sensor in accordance with some example embodiments. Detailed descriptions of substantially identical or similar configurations and structures as described with reference to FIGS. 1 and 2 are omitted.

Referring to FIG. 3, a refractive index matching layer 105 may be disposed between the base layer 100 and the sensing electrodes 110 and 130.

The refractive index matching layer 105 has, for example, a refractive index between the refractive index of the base layer 100 and the refractive index of the first transparent oxide electrode layer 50, and between the first transparent oxide electrode layer 50 and the base layer 100 It can buffer changes in refractive index.

For example, the refractive index matching layer 105 may include an organic insulating material such as acrylic resin or siloxane resin, or an inorganic insulating material such as silicon oxide and silicon nitride. In one embodiment, the refractive index matching layer 105 is titanium oxide (TiO2), zirconium oxide (ZrO ₂ ), tin oxide (SnO ₂ ), alumina (Al ₂ O ₃ ), tantalum oxide (Ta ₂ O ₅ ), etc. It may further include the same inorganic particles. For example, the inorganic particles may be included in the refractive index matching layer 105 to increase the refractive index relatively.

4 is a schematic cross-sectional view illustrating a touch sensor in accordance with some example embodiments.

Referring to FIG. 4, a bridge electrode 115 is formed on the base layer 100, and the insulating layer 120 may partially cover the bridge electrode 115.

The first sensing electrode 110 fills a contact hole formed in the insulating layer 120 and may be formed on the insulating layer 120. The adjacent first sensing electrodes 110 may be electrically connected by the bridge electrode 115 through the contact holes.

The second sensing electrodes 130 may be formed on the insulating layer and extend in a direction crossing the first sensing electrodes 110.

The first sensing electrode 110 and the second sensing electrode 130 may include substantially the same or similar structures and materials as described with reference to FIG. 2.

In some embodiments, the insulating layer 120 and/or the passivation layer 140 illustrated in FIGS. 2 to 4 may have a barrier layer or barrier structure including a barrier material with improved moisture shielding ability.

According to exemplary embodiments, the barrier material is aluminum oxide (eg, Al ₂ O ₃ )-zinc oxide (eg, ZnO) (AZO) composite material (AZO), silazane, siloxane (siloxane) and/or silicon-containing inorganic materials.

In the present application, "silazane" is used as a term encompassing a compound or polymer comprising a "-Si-N-Si-" structure. "Siloxane" is used as a term encompassing a compound or polymer comprising a "-Si-O-Si-" structure.

Examples of the silicon-containing inorganic material include silicon oxide, silicon nitride and/or silicon oxynitride. These may be used alone or in combination of two or more. Preferably, at least two or more of silicon oxide, silicon nitride or silicon oxynitride are used together, and more preferably, silicon oxide, silicon nitride and silicon oxynitride can be used together.

5-10 are schematic cross-sectional views illustrating a barrier structure in accordance with some example embodiments.

As described above, the insulating layer 120 and/or the passivation layer 140 may include a barrier layer including a barrier material. In some embodiments, the insulating layer 120 and/or the passivation layer 140 may include the barrier layer and may include a barrier structure having a multilayer structure.

Referring to FIG. 5, the barrier structure may include a barrier layer 80 including the above-described barrier material and an organic layer 90 stacked on the barrier layer 80.

The organic layer 90 may include, for example, acrylic resin or siloxane resin. As the organic layer 90 is formed on the barrier layer 80, it is possible to prevent or reduce the etching damage of the barrier material. In this case, the barrier layer 80 may include AZO material or silazane.

For example, when the AZO material, which may have relatively poor etch resistance, is included in the barrier layer 80, etching damage is effectively performed through the organic layer 90 (eg, the passivation layer 140 for pad opening) Hour).

Referring to FIG. 6, the barrier structure may include a multi-layered barrier layer stack. For example, the organic layer 90 may be formed on the barrier layer stack including the lower barrier layer 80a and the upper barrier layer 80b.

In one embodiment, the lower barrier layer 80a and the upper barrier layer 80b may each independently include AZO material or silazane.

Referring to FIG. 7, the barrier layer 80 and the organic layer 90 may be alternately and repeatedly stacked. In this case, as the barrier layers 80 are spaced apart from each other and included in a plurality, moisture shielding properties may be further improved. As described above, the barrier layers 80 may each include AZO material or silazane.

Referring to FIG. 8, the barrier structure may have a multi-layer structure (eg, a two-layer structure) including the first barrier layer 82 and the second barrier layer 84.

In one embodiment, the first barrier layer 82 and the second barrier layer 84 may include the silicon-containing inorganic material.

In one embodiment, the first barrier layer 82 includes the silicon-containing inorganic material, and the second barrier layer 84 may include silazane.

Referring to FIG. 9, the second barrier layer 84 may be sandwiched between the first barrier layers 82. For example, the first barrier layers 82 may be formed on the top and bottom surfaces of the second barrier layer 84, respectively.

In one embodiment, the first barrier layers 82 including the silicon-containing inorganic material cover the upper and lower surfaces of the silazane-containing second barrier layer 84, thereby preventing moisture diffusion into the touch sensor. It can be blocked more effectively.

Referring to FIG. 10, the first barrier layer 82 and the second barrier layer 84 may be alternately and repeatedly stacked to form a structure of four or more layers.

In one embodiment, as shown in FIG. 10, the first barrier layers 82 and the silazane-containing second barrier layers 84 including the silicon-containing inorganic material are alternately stacked to form a four-layer structure. The laminate can be utilized as a barrier structure.

Each of the barrier layers illustrated in FIGS. 5 to 10 may be appropriately adjusted in thickness depending on the materials included. For example, when the barrier layer includes an AZO material, the thickness of the barrier layer may be about 10 nm to about 1 μm. When the barrier layer includes silazane, the thickness of the barrier layer may be about 100 nm to 2 μm. When the barrier layer comprises a silicon-containing inorganic material, the thickness of the barrier layer may be about 10nm to about 1㎛.

The moisture permeability of the above-mentioned barrier layer or barrier layer laminate may be in the range of 10 ^-6 to 10 ^-1 g/m ² 24hr at 40 ^o C and 90% relative humidity.

11 is a schematic diagram illustrating a window stack and an image display device according to example embodiments.

Referring to FIG. 11, the window stack 250 may include a window substrate 230, a polarization layer 210, and a touch sensor 200 according to the exemplary embodiments described above.

The window substrate 230 includes, for example, a hard coating film, and in one embodiment, a light blocking pattern 235 may be formed on a peripheral portion of one surface of the window substrate 230. The light blocking pattern 235 may include, for example, a color print pattern, and may have a single layer or multi-layer structure. The bezel area or the non-display area of the image display device may be defined by the light blocking pattern 235.

The polarizing layer 210 may include a coated polarizer or a polarizing plate. The coated polarizer may include a liquid crystal coating layer including a polymerizable liquid crystal compound and a dichroic dye. In this case, the polarization layer 210 may further include an alignment layer for imparting alignment to the liquid crystal coating layer.

For example, the polarizing plate may include a polyvinyl alcohol-based polarizer and a protective film attached to at least one surface of the polyvinyl alcohol-based polarizer.

The polarization layer 210 may be directly bonded to the one surface of the window substrate 230 or may be attached through the first point adhesive layer 220.

The touch sensor 200 may be included in the window stack 250 in the form of a film or panel. In one embodiment, the touch sensor 200 may be combined with the polarization layer 210 through the second point adhesive layer 225.

As illustrated in FIG. 11, the window substrate 230, the polarization layer 210, and the touch sensor 200 may be arranged in order from the user's viewing side. In this case, since the electrode layer of the touch sensor 200 is disposed under the polarization layer 210, the electrode visibility phenomenon can be prevented. In addition, the transmittance through the touch sensor is improved through the sensing electrode stacked structure having the above-described optical ratio range, so that electrode visibility can be more effectively suppressed.

In one embodiment, the touch sensor 200 may be directly transferred onto the window substrate 230 or the polarization layer 210. In an embodiment, the window substrate 230, the touch sensor 200, and the polarization layer 210 may be arranged in the order of the user's view side.

The image display device may include a display panel 360 and the above-described window stack 250 coupled to the display panel 360.

The display panel 360 includes a pixel electrode 310, a pixel defining layer 320, a display layer 330, a counter electrode 340 and an encapsulation layer 350 disposed on the panel substrate 300. Can.

A pixel circuit including a thin film transistor (TFT) is formed on the panel substrate 300, and an insulating film covering the pixel circuit may be formed. The pixel electrode 310 may be electrically connected to the drain electrode of the TFT, for example, on the insulating film.

The pixel defining layer 320 is formed on the insulating layer to expose the pixel electrode 310 to define a pixel area. The display layer 330 is formed on the pixel electrode 310, and the display layer 330 may include, for example, a liquid crystal layer or an organic emission layer.

The counter electrode 340 may be disposed on the pixel defining layer 320 and the display layer 330. The counter electrode 340 may be provided as, for example, a common electrode or cathode of the image display device. An encapsulation layer 350 for protecting the display panel 360 may be stacked on the counter electrode 340.

In some embodiments, the display panel 360 and the window stack 250 may be combined through the point adhesive layer 260. For example, the thickness of the point adhesive layer 260 may be greater than the thickness of each of the first and second point adhesive layers 220 and 225, and the viscoelasticity at -20 to 80°C may be about 0.2 MPa or less. In this case, noise from the display panel 360 can be shielded, and interfacial stress can be relaxed during bending to suppress damage to the window stack 250. In one embodiment, the viscoelasticity may be about 0.01 to 0.15MPa.

Hereinafter, experimental examples including preferred embodiments are provided to help understanding of the present invention, but these examples are only illustrative of the present invention and do not limit the appended claims, and the scope and technical idea of the present invention. It is apparent to those skilled in the art that various changes and modifications to the embodiments within the scope are possible, and it is natural that such modifications and modifications fall within the scope of the appended claims.

Experimental Example 1: Evaluation of optical properties according to Equation 1

Examples and comparative examples having a layered structure of an IZO layer (refractive index: 1.96, thickness 350 Å)-metal layer (thickness: 100 Å)-IZO layer (refractive index: 1.96, thickness: 350 Å) on a COP film (self-transmittance 90%) A sensing electrode layer according to the fields was formed. The material, refractive index and extinction coefficient of the metal layer are as shown in Table 1 below.

Optical characteristics of the sensing electrode layers of Examples and Comparative Examples were evaluated. Specifically, the reflectance and transmittance of the wavelength light for the sensing electrode layer according to Examples and Comparative Examples were measured in a wavelength range of 360 to 740 nm, and the extinction coefficient of the metal layer at a wavelength of 550 nm was calculated to evaluate the optical properties as follows. Did.

<Evaluation criteria for optical properties>

○: Reflectance <10%, Transmittance> 80%

△: Reflectance 10 to 15%, Transmittance 70 to 80%

×: Reflectance >15%, Transmittance <70%

The evaluation results are shown in Table 1 below.

Experimental Example 2: Evaluation of the optical properties according to the thickness change

The transmittance, reflectance, and color coordinate values (a*, b*) were measured using CM-3600A (manufactured by Minolta) for samples in which the thickness of each layer of the sensing electrode having the layered structure of Example 3 was changed.

The measurement results are shown in Table 2 below.

Referring to Table 2, for samples satisfying the above-described optical ratio range and the thickness range of each layer of the sensing electrode, a color coordinate value in the range of ±10 was obtained indicating a transmittance of about 84% or more and a reflectivity of less than about 7% as a whole. .

Experimental Example 3: Evaluation of folding properties

For the touch sensor samples of Examples 1 and 2, the line resistance was evaluated after 100 foldings and 600,000 foldings under a curvature of 2R (2 mm). The evaluation results are shown in Table 3 below.

Referring to Table 3, it was confirmed that even after 600,000 folding, the line resistance value after 100 folding was substantially maintained.

Experimental Example 4: Evaluation of barrier layer moisture permeability

As described above, the moisture permeability was evaluated at 40 ^° C and 90% relative humidity conditions of a plurality of samples in which the material of the barrier layer applied to the passivation layer and/or insulating layer of the touch sensor was changed.

Specifically, a sample having a size of 50 cm ² was prepared and moisture permeability was measured using Percontran W-3/33 and Aquatran 2 of MOCON.

The evaluation results are shown in Table 4 below.

Referring to Table 4, the moisture permeability was reduced to less than 10 ^-1 g/m ² 24 ^hr using AZO or silazane. When using a silicon-containing inorganic material, the moisture permeability was reduced more effectively when using a composite layer of different materials.

Claims (20)

1. Base layer; And

   A touch sensor, which is arranged on the base layer and includes a stacked structure of a transparent oxide electrode layer and a metal layer, and includes sensing electrodes having an optical ratio of 5 or less as defined by Equation 1 below:

   [Equation 1]

   Optical ratio = extinction coefficient of metal layer/(|transparent oxide electrode layer refractive index-metal layer refractive index|).
2. The touch sensor according to claim 1, wherein the optical ratio of the sensing electrode is 3 or less.
3. The touch sensor of claim 1, wherein the sensing electrode includes a first transparent oxide electrode layer, the metal layer, and a second transparent oxide electrode layer sequentially stacked on the base layer.
4. The touch sensor according to claim 3, wherein an optical ratio between the metal layer and the first transparent oxide electrode layer is 5 or less, and an optical ratio between the metal layer and the second transparent oxide electrode layer is 5 or less.
5. The touch sensor according to claim 3, wherein the thickness of the first transparent oxide electrode layer and the second transparent oxide electrode layer is 100 to 700 Pa, respectively, and the thickness of the metal layer is 50 to 300 Pa.
6. The touch sensor according to claim 3, wherein the thickness of the first transparent oxide electrode layer and the second transparent oxide electrode layer is 300 to 500 Pa, respectively, and the thickness of the metal layer is 70 to 150 Pa.
7. The touch sensor according to claim 3, further comprising a refractive index matching layer formed between the first transparent oxide electrode layer and the base layer.
8. The touch sensor according to claim 7, wherein the refractive index matching layer has a refractive index of the base layer and a refractive index between the first transparent oxide electrode layer.
9. The method according to claim 1, The refractive index of the transparent oxide electrode layer is 1.7 to 2.2, the touch sensor.
10. The touch sensor according to claim 1, wherein the metal layer comprises a silver (Ag) alloy.
11. The touch sensor according to claim 1, wherein the sensing electrodes include first sensing electrodes and second sensing electrodes arranged in directions intersecting each other.
12. The touch sensor according to claim 11, wherein the second sensing electrodes are integrally connected in a column direction by a connection unit.
13. The method according to claim 12, The first sensing electrodes are spaced apart from each other in a row direction with the connecting portion therebetween,

    And a bridge electrode electrically connecting the adjacent first sensing electrodes to each other with the connection portion interposed therebetween.
14. The method according to claim 11, The first sensing electrode and the insulating layer insulating the second sensing electrode from each other; And

    Further comprising a passivation layer formed on the insulating layer,

    At least one of the insulating layer or the passivation layer comprises a barrier layer or barrier structure comprising an aluminum oxide-zinc oxide (AZO) composite material, silazane, siloxane or silicon-containing inorganic material sensor.
15. The touch sensor according to claim 14, wherein the barrier structure further comprises an organic layer stacked on the barrier layer.
16. The touch sensor of claim 15, wherein the barrier structure includes the barrier layers and organic layers alternately stacked.
17. The touch sensor according to claim 14, wherein the barrier layer has a multilayer structure including a first barrier layer and a second barrier layer.
18. The touch sensor of claim 17, wherein the first barrier layer comprises the silicon-containing inorganic material, and the second barrier layer comprises silazane.
19. Window substrates; And

    A window stack comprising the touch sensor of claim 1 stacked on the window substrate.
20. Display panel; And

    An image display device comprising the touch sensor of claim 1 stacked on the display panel.

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