KR102015864B1 - Touch sensor and display device including the same - Google Patents

Abstract

The touch sensor of the present invention includes a base layer, a plurality of sensing electrodes each comprising a first transparent conductive oxide pattern, a metal pattern and a second transparent conductive oxide pattern sequentially stacked on the base layer, and a surface of each sensing electrode. Conductive capping pattern covering the. By the electroconductive capping pattern, corrosion and damage by the external environment of a metal pattern can be suppressed.

Description

TOUCH SENSOR AND DISPLAY DEVICE INCLUDING THE SAME}

The present invention relates to a touch sensor and an image display device including the same. More particularly, the present invention relates to a touch sensor including an electrode pattern having a multilayer structure, and an image display device including the same.

Recently, with the development of information technology (IT), the demand for the display field is also presented in various forms. For example, a flat panel display device having features such as thinness, light weight, and low power consumption, for example, a liquid crystal display device, a plasma display panel device, Electro luminescent display devices and organic light-emitting diode display devices have been studied.

On the other hand, a touch screen panel, which is an input device that is embedded on the display device and inputs a user's command by selecting an instruction content displayed on the screen with a human hand or an object, is combined with a display device to display an image BACKGROUND Electronic devices in which display and information input functions are implemented are being developed.

The touch screen panel may be classified into a capacitive type, a light sensing type, a resistive film type, and the like according to an operation method of the touch sensor. In the case of a capacitive touch sensor, when a human hand or an object comes into contact with each other, the sensing position is converted into an electrical signal by detecting a change in capacitance formed by another sensing pattern or a ground electrode.

When the conductive sensing pattern included in the touch sensor is applied to a display device, it is necessary to have high transparency and have improved electrical characteristics (eg, low resistance). It is also necessary to have improved resistance or resistance to external humidity, denaturation by air.

Recently, a flexible display that can be folded or bent has been developed. When the touch sensor is applied to the flexible display, the conductive sensing pattern also needs to have improved flexibility or flexibility.

For example, as disclosed in Korean Patent Application Publication No. 2014-0092366, a touch screen panel in which a touch sensor is coupled to various image display devices has recently been developed, but as described above, a touch sensor having improved optical, electrical, and mechanical properties, or The demand for touch panels continues.

Korean Patent Publication No. 2014-0092366

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

One object of the present invention is to provide a touch screen panel or an image display device including a touch sensor with improved optical, electrical, and mechanical properties.

1. Base layer; A plurality of sensing electrodes each including a first transparent conductive oxide pattern, a metal pattern, and a second transparent conductive oxide pattern sequentially stacked on the base layer; And a conductive capping pattern covering a surface of each of the sensing electrodes.

2. In the above 1, wherein the first transparent conductive oxide pattern, the second transparent conductive oxide pattern and the conductive capping pattern are each independently indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc oxide ( IZTO), aluminum zinc oxide (AZO), zinc oxide (ZnOx), indium oxide (InOx), tin oxide (SnOx), cadmium tin oxide (CTO), gallium-doped zinc oxide (GZO), zinc tin oxide (ZTO) And at least one selected from the group consisting of indium gallium oxide (IGO).

3. In the above 1, the metal pattern is gold (Au), silver (Ag), copper (Cu), aluminum (Al), platinum (Pt), palladium (Pd), chromium (Cr), tungsten (W) , Titanium (Ti), tantalum (Ta), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), vanadium (V), niobium (Nb), telenium (Te) and molybdenum (Mo) Touch sensor comprising at least one metal selected from the group consisting of), an alloy of the metal or nanowire of the metal.

4. In the above 1, wherein the sensing electrode includes a mesh pattern structure, the touch sensor.

5. In the above 1, wherein the conductive capping pattern covers the side wall and the upper surface of the sensing electrode, the touch sensor.

6. In the above 1, wherein the width of the conductive capping pattern increases toward the base layer side, the touch sensor.

7. In the above 1, the insulating layer covering the sensing electrodes; And a bridge pattern penetrating the insulating layer and electrically connecting neighboring sensing electrodes of the sensing electrodes, wherein the bridge pattern is in contact with the conductive capping pattern.

8. The touch sensor according to the above 1, further comprising a pad connecting the sensing electrodes and an external circuit to each other.

9. In the above 8, wherein the pad includes a first transparent conductive oxide pattern, a metal pattern and a second transparent conductive oxide pattern of the same material as the sensing electrode, the touch sensor.

10. The touch sensor of claim 8, wherein the conductive capping pattern includes a first conductive capping pattern covering the sensing electrode and a second conductive capping pattern covering the pad.

11. The touch sensor according to the above 10, further comprising a passivation layer formed with a contact hole exposing an upper surface of the second conductive capping pattern.

12. The touch sensor of claim 11, wherein the external circuit contacts the second conductive capping pattern through the contact hole.

13. In the above 1, wherein the base layer includes at least one intermediate layer containing an organic polymer, the touch sensor.

14. base layer; A plurality of sensing electrodes arranged on the base layer; And a bridge pattern that electrically connects some of the sensing electrodes that are adjacent to the sensing electrodes.

At least one of the sensing electrode or the bridge pattern has a laminated structure including a first transparent conductive oxide pattern, a metal pattern, and a second transparent conductive oxide pattern sequentially disposed, and includes a conductive capping pattern covering a surface of the stacked structure. Including, touch sensor.

15. The touch sensor of claim 14, wherein the conductive capping pattern includes a conductive metal oxide.

16. Image display device comprising the touch sensor of any one of 1 to 15 above.

In the touch sensor according to the embodiments of the present invention, the sensing electrode may be formed in a multilayer structure including a first transparent conductive oxide pattern-metal pattern-second transparent conductive oxide pattern layered structure. Therefore, while improving the transmittance of the touch sensor, it is possible to implement a high sensitivity sensing electrode by reducing the channel resistance of the sensing electrode. In addition, flexible characteristics such as folding and bending may be improved by the metal pattern inserted in the middle.

In addition, according to example embodiments, a conductive capping pattern covering the surface of the sensing electrode may be formed. The conductive capping pattern may prevent corrosion of the metal pattern, corrosion due to air contact, and damage. Therefore, it is possible to obtain a touch sensor having improved reliability with respect to the external environment.

In addition, the conductive capping pattern may be formed on the pad formed on the wiring part, and the reliability of the pad exposed for connection with the driving circuit may be improved.

The touch sensor has excellent electrical and mechanical reliability and can be effectively applied to an image display device such as a flexible OLED and an LCD device.

1 is a schematic cross-sectional view illustrating a touch sensor according to example embodiments.
2 is a schematic cross-sectional view illustrating a touch sensor in accordance with example embodiments.
3 is a schematic cross-sectional view illustrating a touch sensor according to exemplary embodiments.
4 and 5 are plan and cross-sectional views illustrating a sensing electrode structure of a touch sensor according to some embodiments.
6 is a schematic cross-sectional view illustrating an image display device according to example embodiments.

Embodiments of the invention include a base layer; A plurality of sensing electrodes each including a first transparent conductive oxide pattern, a metal pattern, and a second transparent conductive oxide pattern sequentially stacked on the base layer; And a conductive capping pattern covering a surface of each sensing electrode. Corrosion resistance of the sensing electrode may be improved by the conductive capping pattern, and desired electrical operation characteristics may be maintained with high reliability.

Hereinafter, with reference to the accompanying drawings, it will be described an embodiment of the present invention in more detail. However, the following drawings attached to the specification are for exemplifying preferred embodiments of the present invention, and together with the contents of the present invention serves to further understand the technical spirit of the present invention, the present invention described in such drawings It should not be construed as limited to matters.

1 to 3 are schematic cross-sectional views illustrating touch sensors according to exemplary embodiments.

Referring to FIG. 1, the touch sensor may include a base layer 100, sensing electrodes 140 stacked on the base layer 100, and a passivation layer 160 covering the sensing electrodes 140. have.

The base layer 100 may be provided as a support layer for forming the sensing electrode 140. In the present specification, the base layer 100 is used to encompass the lower member of the sensing electrode 140. For example, the base layer 100 may include a film-type member or a substrate, or may include an object (eg, a display panel of a display device) on which the sensing electrode 140 is formed.

The base layer 100 may be, for example, glass, plastic, or polyimide (PI), polycarbonate (PC), polyethylene terephthalate (PET), polymethylmethacrylate (PMMA), triacetyl cellulose (TAC), or the like. The same flexible resin may be included.

The sensing electrode 140 may include a first transparent conductive oxide pattern 110, a metal pattern 120, and a second transparent conductive oxide pattern 130 sequentially formed on the base layer 100.

The first transparent conductive oxide pattern 110 may be provided as a barrier to, for example, an organic material that is diffused from the base layer 100. In addition, the first transparent conductive oxide pattern 110 may function as a lower barrier or lower protective pattern of the metal pattern 120.

The first transparent conductive oxide pattern 110 is a non-limiting example, indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc oxide (IZTO), aluminum zinc oxide (AZO), zinc oxide (ZnOx) Metal oxides having conductivity such as indium oxide (InOx), tin oxide (SnOx), cadmium tin oxide (CTO), gallium-doped zinc oxide (GZO), zinc tin oxide (ZTO), indium gallium oxide (IGO), and the like. It may include. These may be used alone or in combination of two or more.

In an exemplary embodiment, the first transparent conductive oxide pattern 110 may be formed of IZO in consideration of low temperature crystallinity and barrier property improvement.

In one embodiment, the first transparent conductive oxide pattern 110 may be formed to a thickness of about 10 to 70nm. When the thickness of the first transparent conductive oxide pattern 110 is less than about 10 nm, sufficient barrier function for the organic material may not be implemented. When the thickness of the first transparent conductive oxide pattern 110 exceeds about 70 nm, the resistance of the sensing electrode 140 may be excessively increased and a uniform pattern shape may not be easily implemented.

In example embodiments, the refractive index of the first transparent conductive oxide pattern 110 may range from about 1.7 to 2.2 in consideration of optical compatibility with the metal pattern 120.

Metal pattern 120 is a non-limiting example, gold (Au), silver (Ag), copper (Cu), aluminum (Al), platinum (Pt), palladium (Pd), chromium (Cr), tungsten (W) ), Titanium (Ti), tantalum (Ta), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), telenium (Te), vanadium (V), niobium (Nb), molybdenum ( Metals such as Mo), alloys of these metals (eg, silver-palladium-copper (APC)), nanowires of metals or alloys. In one embodiment, the metal pattern 125 may be formed to include the APC for low resistance and high sensitivity.

As the metal pattern 120 is included in the sensing electrode 140, the flexible characteristic may be improved and the channel resistance may be reduced, compared with the case in which the sensing electrode 140 is made of a transparent conductive oxide.

The thickness of the metal pattern 120 is not particularly limited, but may be about 5 to 30 nm.

The second transparent conductive oxide pattern 130 may include the conductive metal oxide described above. The second transparent conductive oxide pattern 130 may include the same or different conductive metal oxide as the first transparent conductive oxide pattern 110.

In an exemplary embodiment, the second transparent conductive oxide pattern 130 may be formed of ITO in consideration of an aspect of improving conductivity and transmittance.

In one embodiment. The thickness of the second transparent conductive oxide pattern 130 may be about 10 to 140 nm. In the etching process for forming the sensing electrode 140, the second transparent conductive oxide pattern 130 may have a thickness greater than that of the first transparent conductive oxide pattern 110 to prevent damage to the metal pattern 120.

For example, when the thickness of the second transparent conductive oxide pattern 130 is less than about 10 nm, a sufficient upper barrier may not be provided for the metal pattern 120. When the thickness of the second transparent conductive oxide pattern 130 exceeds about 140 nm, the transmittance of the touch sensor may be excessively reduced, and an etching process time for forming the sensing electrode 140 may be excessively increased.

In example embodiments, the refractive index of the second transparent conductive oxide pattern 130 may range from about 1.7 to 2.2 in consideration of optical compatibility with the metal pattern 120.

In example embodiments, the sensing electrode 140 may include a mesh pattern structure. For example, the first transparent conductive oxide pattern 110, the metal pattern 120, and / or the second transparent conductive oxide pattern 130 included in the sensing electrode 140 may be formed in the mesh pattern structure.

The mesh pattern may include an internal structure in the form of a net or honeycomb. The mesh pattern may include a rectangular rectangular mesh structure, a rhombus mesh structure, a hexagonal mesh structure, or the like, and may include a concave polygonal mesh structure.

As the sensing electrode 140 has a mesh pattern structure, a bending characteristic may be improved, and thus a touch sensor having excellent flexibility and elasticity may be implemented.

According to embodiments of the present invention, the conductive capping pattern 135 may be formed on the surface of each sensing electrode 140. In example embodiments, the conductive capping pattern 135 may cover the sidewall and the top surface of each sensing electrode 140.

Since the sidewall of the metal pattern 120 is covered by the conductive capping pattern 135, corrosion or oxidation of the metal pattern 120 may be blocked by external moisture or air. In addition, for example, contact between the organic material that is not blocked by the first transparent conductive oxide pattern 110 and the sidewall of the metal pattern 120 may be suppressed.

The conductive capping pattern 135 may be formed of a conductive metal oxide having improved chemical resistance than metal while securing a predetermined conductivity and transmittance. In one embodiment, the conductive capping pattern 135 may include ITO or IZO.

The thickness of the conductive capping pattern 135 (eg, the thickness from the top surface of the sensing electrode 140) may be about 30 to 300 nm. When the thickness of the conductive capping pattern 135 is less than about 30 nm, the thickness from the sidewall of the sensing electrode 140 may also decrease, so that sufficient barrier characteristics for the metal pattern 120 may not be realized.

In an embodiment, the thickness of the conductive capping pattern 135 may be adjusted to about 30 to 50 nm to suppress the increase in resistance of the sensing electrode 140 due to the increase in the thickness of the conductive capping pattern 135.

In some embodiments, as shown in FIG. 1, the conductive capping pattern 130 may have a substantially trapezoidal cross-sectional profile. For example, the conductive capping pattern 130 may have a tapered shape such that its width increases toward the base layer 100.

Accordingly, in the etching process for forming the conductive capping pattern 135, the thickness of the portion adjacent to the metal pattern 120 may be reduced to prevent the sufficient barrier property from being secured. In addition, as the thickness of the portion of the conductive capping pattern 135 in contact with the base layer 100 increases, it is possible to more effectively block diffusion of the organic material from the base layer 100.

For example, the first transparent conductive oxide layer, the metal layer, and the second transparent conductive oxide layer may be formed on the base layer 100 through a deposition process such as a sputtering process or a coating process of the conductive composition.

Thereafter, the second transparent conductive oxide layer, the metal layer, and the first transparent conductive oxide layer may be sequentially etched to form the sensing electrodes 140 through a photolithography process using a first photo mask.

Subsequently, after forming the conductive capping layer covering the sensing electrodes 140, the conductive capping layer may be patterned through a photolithography process using a second photo mask to form the conductive capping pattern 135.

For example, the conductive capping pattern 135 may be formed in a spacer shape formed on the outer wall of the sensing electrode 140.

The passivation layer 160 may be formed on the base layer 100 to cover the sensing electrodes 140 and the conductive capping pattern 135. The passivation layer 160 may include, for example, an inorganic oxide such as silicon oxide, or an organic insulating material.

As described above, the sensing electrode 140 of the touch sensor according to the exemplary embodiments may include a first transparent conductive oxide pattern 110 / metal pattern 120 / second transparent conductive oxide pattern 130. It may comprise a layer structure. As the metal pattern 120 is inserted into the sensing electrode 140, sensitivity and flexibility of the touch sensor may be improved by reducing channel resistance. In addition, as the metal pattern 120 is sandwiched by the first and second transparent conductive oxide patterns 110 and 130, the transmittance of the touch sensor may be improved, and corrosion and damage of the metal pattern 120 may be blocked. .

In addition, as the sidewall of the metal pattern 120 is covered by the conductive capping pattern 135, the reliability of the metal pattern 120 from the external environment may be further improved.

For example, the conductive capping pattern 135 may have a refractive index in the range of about 1.7 to 2.2. Accordingly, even in light directed toward the sidewall of the metal pattern 120, the refractive index matching effect may be improved to reduce the visibility of the sensing electrode 140.

Referring to FIG. 2, an intermediate layer may be provided as a base layer for forming the sensing electrode 140. The intermediate layer may have a single layer or a multilayer structure. In example embodiments, the intermediate layer may include a first intermediate layer 80 and a second intermediate layer 90. At least one of the first intermediate layer 80 or the second intermediate layer 90 may include an organic polymer.

In example embodiments, the first intermediate layer 80 may be included as a functional layer to facilitate subsequent peeling or separation with the carrier substrate. For example, the first intermediate layer 80 may be made of polyimide, poly vinyl alcohol, polyamic acid, polyamide, polyethylene, polystyrene, poly Norbornene, phenylmaleimide copolymer, polyazobenzene, polyphenylenephthalamide, polyester, polymethyl methacrylate, polyarylate (polyarylate), cinnamate (cinnamate), coumarin (coumarin), phthalimidine (phthalimidine), chalcone (chalcone), may include polymers such as aromatic acetylene. These may be used alone or in combination of two or more thereof.

The second intermediate layer 90 may be added to protect the sensing electrode 140 in the peeling process. In addition, the second intermediate layer 90 may be formed to match the refractive index with the sensing electrode 140. For example, the second intermediate layer 90 may include an inorganic insulating material such as silicon oxide, silicon nitride, silicon oxynitride, or the like, or a polymer-based organic insulating material.

In some embodiments, after the carrier substrate is peeled off from the first intermediate layer 80 through the peeling process, the substrate 70 may be bonded to the bottom surface of the first intermediate layer 80. For example, the substrate 70 may be attached to the first intermediate layer 80 through an adhesive layer. The substrate 70 may include, for example, a flexible resin film such as polyimide, or various optical functional layers such as a polarizing film.

Referring to FIG. 3, an optical functional layer 170 may be stacked on the passivation layer 160. For example, the optical function layer 170 may include a coated polarizer or an elongated polarizer.

The stretched polarizing plate includes a protective film and a polarizer, and after applying an adhesive layer on the protective film, the polarizing plate may be bonded onto the passivation layer 160.

The optical function layer 170 may include a retardation plate, a hard coating layer, a color control layer, and the like.

4 and 5 are plan and cross-sectional views illustrating a sensing electrode structure of a touch sensor according to some embodiments. For example, FIG. 5 includes a cross-sectional view taken along the line III-III ′ of FIG. 4 in the thickness direction of the touch sensor. For example, FIG. 4 is a plan view in the first region I shown in FIG. 5.

On the other hand, detailed description of the configuration and / or material substantially the same as described with reference to Figures 1 to 3 is omitted.

4 and 5, the touch sensor may include a first region I and a second region II. For example, the first region I may correspond to a sensing region that detects a touch point and generates location information. The second area II may correspond to a wiring area or a trace area of the touch sensor. Accordingly, the base layer including the first intermediate layer 80 and the second intermediate layer 90 may also be divided into a first region I and a second region II.

The sensing electrodes 141 and 143 are disposed in the first region I of the touch sensor, and respectively, of the first transparent conductive oxide pattern 110, the metal pattern 120, and the second transparent conductive oxide pattern 130. It may include a laminated structure. The sensing electrodes may include a first sensing electrode 141 and a second sensing electrode 143. First conductive capping patterns 136 may be formed on surfaces of the sensing electrodes 141 and 143, respectively.

The first sensing electrode 141 may extend, for example, in which polygonal unit patterns are connected in a row direction through the connection part 141a. Thus, a first sensing line in the row direction is defined, and a plurality of the first sensing lines may be arranged in the column direction.

The second sensing electrode 143 may include, for example, a polygonal island pattern that is physically spaced apart from each other. The second sensing electrodes 143 may be spaced apart from the first sensing electrodes 141 to be electrically and physically separated. For example, the second sensing electrodes 143 may be spaced apart from each other with the connection part 141a of the first sensing electrode 141 interposed therebetween in the column direction.

For example, an insulating layer 150 is formed on the second intermediate layer 90 to fill a space between the first and second sensing electrodes 141 and 143 and to fill the space between the first and second sensing electrodes 141 and 143. , And may cover the first conductive capping pattern 136. In some embodiments, the insulating layer 150 may be selectively formed in the first region (I).

The insulating layer 150 may include, for example, an inorganic insulating material such as silicon oxide, or a transparent organic material such as acrylic resin. Preferably, the insulating layer 150 may be formed from an organic resin composition including a thermosetting or photocurable material such as an epoxy compound, an acrylic compound, a melanin compound, and the like.

The insulating layer 150 may include a first contact hole that at least partially exposes an upper surface of the conductive capping pattern 135 formed on the second sensing electrode 143. For example, the contact hole may be formed on the insulating layer 150 through an exposure process and a development process using a third photo mask.

A bridge pattern 155 may be disposed on the insulating layer 150. The bridge pattern 155 may fill the first contact holes and electrically connect the pair of second sensing electrodes 143 neighboring in the column direction.

The bridge pattern 155 may directly contact the first conductive capping pattern 136 covering the second sensing electrode 143 on the first region I. The first conductive capping pattern 136 may function as an intermediary electrode between the bridge pattern 155 and the second sensing electrode 143.

A second sensing line extending in the column direction may be defined while maintaining insulation from the first sensing electrodes 141 by the bridge pattern 155 and the second sensing electrodes 143. A plurality of second sensing lines may be arranged in the row direction.

In some example embodiments, the bridge pattern 155 may also have a structure substantially the same as or similar to that of the sensing electrodes 141 and 143. For example, the bridge pattern 155 may have a stacked structure including a first transparent conductive oxide pattern, a metal pattern, and a second transparent conductive oxide pattern, and may include a conductive capping pattern covering a surface of the stacked structure.

In some embodiments, any one of the sensing electrodes 141 and 143 or the bridge pattern 155 may include the aforementioned stacked structure and the conductive capping pattern. In addition, both the sensing electrodes 141 and 143 and the bridge pattern 155 may include the above-described stacked structure and conductive capping pattern.

The first and second sensing lines are connected to, for example, wires or traces of the touch sensor, and the wires or traces are, for example, through a pad 147 disposed on the second area II. It may be connected to an external circuit or a driving circuit.

In example embodiments, the pad 147 may also include a stacked structure of the first transparent conductive oxide pattern 110, the metal pattern 120, and the second transparent conductive oxide pattern 130. In addition, the second conductive capping pattern 137 may cover the sidewalls and the top surface of the pad 147.

In some embodiments, the pad 147 may be formed through an etching process substantially the same as the sensing electrodes 141 and 143. In addition, the first and second conductive capping patterns 136 and 137 may also be formed together through substantially the same etching process.

The passivation layer 160 may cover the first and second regions I and II in common and may cover the bridge pattern 155.

A second contact hole 165 may be formed in a portion of the passivation layer 160 of the second region II. An external circuit member such as, for example, a flexible circuit board FPBC may be electrically connected to the pad 147 through the second contact hole 165.

In example embodiments, an upper surface of the second conductive capping pattern 137 may be exposed through the second contact hole 165. As the pad 147, which may be exposed to the outside air through the second contact hole 165, is covered by the second conductive capping pattern 137, the pad 147 (for example, the pad 147 may be included in the pad 147). Signal transmission error or resistance increase due to oxidation or corrosion of the metal pattern 120 may be prevented.

In addition, penetration or diffusion of the metal pattern 120 by diffusion of the organic material included in the passivation layer 160 may be blocked by the second conductive capping pattern 137.

In some embodiments, the pad 147 and / or the bridge pattern 155 may include a mesh pattern structure that is substantially the same as or similar to the sensing electrode.

In some embodiments, the touch sensor may be driven in a mutual capacitive manner.

In some embodiments, the touch sensor may be driven in a self capacitance manner. In this case, each of the sensing electrodes may include an independent island pattern unit pattern, and each of the unit patterns may be connected to a trace or a wire. In this case, the bridge pattern may be omitted. In one embodiment, the trace or wiring can also be surrounded or covered by a conductive capping pattern.

6 is a schematic cross-sectional view illustrating an image display device according to example embodiments.

Referring to FIG. 6, the image display device includes a base substrate 200, a pixel defining layer 205, a display layer 210, an electrode 215, an interlayer insulating layer 220 and 230, a sensing electrode 140, and passivation. The layer 160, the optical layer 240, and the window substrate 250 may be included.

The base substrate 200 may be a support substrate of a display pattern. According to example embodiments, the base substrate 200 may include a resin material having flexibility such as polyimide. In this case, the image display device may be provided as a flexible display.

The pixel defining layer 205 may be formed on the base substrate 200 to expose a pixel region in which a color or an image is implemented. A thin film transistor (TFT) array may be formed between the base substrate 200 and the pixel defining layer 205, and an insulating structure covering the TFT array may be formed. The pixel defining layer 205 may be formed on the insulating structure, for example, to expose a pixel electrode (for example, an anode) that penetrates the insulating structure and is electrically connected to the TFT.

For each pixel area exposed by the pixel defining layer 205, a display layer 210 may be formed. For example, the display layer 210 may include an organic light emitting material, and in this case, the image display device may be provided as an OLED device. The display layer 210 may include a liquid crystal material. In this case, the image display device may be provided as an LCD device.

An electrode 215 may be disposed on the pixel defining layer 205 and the display layer 210. The electrode 215 may be provided as a counter electrode facing the pixel electrode. The electrode 215 may be a cathode of the image display device, and may be a common electrode continuously extending on the plurality of pixel areas.

Interlayer insulating layers 220 and 230 may be formed on the electrode 215. The interlayer insulating layer may include a first interlayer insulating layer 220 and a second interlayer insulating layer 230. The first interlayer insulating film 220 may be provided as a planarization film, and the second interlayer insulating film 230 may be provided as an encapsulation film.

The touch sensor according to the exemplary embodiments described above may be disposed on the interlayer insulating layer. The touch sensor may include a sensing electrode 140 including a first transparent conductive oxide pattern 110, a metal pattern 120, and a second transparent conductive oxide pattern 130. The surface of the sensing electrode 140 may be encapsulated substantially by the conductive capping pattern 135.

Since the sensing electrode 140 has the improved transmittance as described above, the sensing electrode 140 may be distributed together on the pixel defining layer 205 and the pixel area. In some embodiments, the sensing electrode 140 overlaps the pixel defining layer 205 and may be arranged not to overlap the pixel area.

The passivation layer 160 covering the sensing electrode 140 may be formed on the second interlayer insulating layer 230, and the optical layer 240 and the window substrate 250 may be stacked on the passivation layer 160.

The optical layer 240 may include a functional layer capable of improving optical characteristics, transmittance, etc. of an image display device such as a polarizer, a polarizing plate, a retardation film, and the like. The window substrate 250 may function as an encapsulation layer exposed to the user side.

The touch sensor according to the exemplary embodiments may be implemented in, for example, a flexible OLED device, and an image display device having improved bending characteristics and improved durability and reliability for an external environment may be implemented.

Hereinafter, experimental examples including preferred embodiments are provided to help understanding of the present invention, but these examples are only for exemplifying the present invention, and do not limit the appended claims, and the scope and spirit of the present invention. It is apparent to those skilled in the art that various changes and modifications to the embodiments can be made within the scope, and such variations and modifications are within the scope of the appended claims.

Experimental Example

A sensing electrode including the first transparent conductive oxide pattern, the metal pattern, and the second transparent conductive oxide pattern was formed on the glass substrate in the thickness and material shown in Table 1. The width of the sensing electrode was patterned to be 30 μm.

In the case of the sensing electrode of the embodiment, the conductive capping pattern was formed using ITO. In the sensing electrode of the comparative examples, the formation of the conductive capping pattern was omitted.

division First transparent conductive oxide pattern
(IZO) (nm) Metal pattern
(APC) (nm) Second transparent conductive oxide pattern
(IZO) (nm) Conductive Capping Pattern
(ITO) (nm) Example 1 40 10 140 300 Example 2 40 10 40 135 Comparative Example 1 40 10 140 - Comparative Example 2 40 10 90 - Comparative Example 3 40 10 10 - Comparative Example 4 40 10 40 -

The time for which corrosion of the metal pattern was observed was left at 85 ° C. and 85% relative humidity for the sensing electrodes of Examples and Comparative Examples. The evaluation results are shown in Table 2.

time 500hr 650 hr 800 hr 1000hr Example 1 X X X X Example 2 X X X X Comparative Example 1 X X X ○ Comparative Example 2 X X X ○ Comparative Example 3 X ○ - - Comparative Example 4 X X ○ -

Referring to Table 2, corrosion of the metal pattern was not observed even after 1000 hours in the sensing electrode of the embodiment in which the conductive capping pattern was formed. In the comparative examples, corrosion of the metal pattern was observed as the thickness of the second transparent conductive oxide pattern decreased.

70: base material 80: first intermediate layer
90: second intermediate layer 110: first transparent metal oxide pattern
120: metal pattern 130: second transparent metal oxide pattern
135: conductive capping pattern 136: first conductive capping pattern
137: second conductive capping pattern 140: sensing electrode
141: first sensing electrode 143: second sensing electrode
150: insulating layer 155: bridge pattern
160: passivation layer 200: base substrate
205: pixel defining layer 210: display layer
215: electrodes 220 and 230: first and second interlayer insulating films

Claims (16)

Base layer;
A plurality of sensing electrodes each including a first transparent conductive oxide pattern, a metal pattern, and a second transparent conductive oxide pattern sequentially stacked on the base layer; And
And a conductive capping pattern covering the surface of each sensing electrode and including indium tin oxide (ITO) or indium zinc oxide (IZO).
The method of claim 1, wherein the first transparent conductive oxide pattern and the second transparent conductive oxide pattern are each independently indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc oxide (IZTO), aluminum zinc oxide ( AZO), zinc oxide (ZnOx), indium oxide (InOx), tin oxide (SnOx), cadmium tin oxide (CTO), gallium-doped zinc oxide (GZO), zinc tin oxide (ZTO) and indium gallium oxide (IGO) Touch sensor comprising at least one selected from the group consisting of.
The method of claim 1, wherein the metal pattern is gold (Au), silver (Ag), copper (Cu), aluminum (Al), platinum (Pt), palladium (Pd), chromium (Cr), tungsten (W), titanium (Ti), tantalum (Ta), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), vanadium (V), niobium (Nb), telenium (Te) and molybdenum (Mo) At least one metal selected from the group consisting of, the alloy of the metal or nanowire of the metal, the touch sensor.
The touch sensor of claim 1, wherein the sensing electrode comprises a mesh pattern structure.
The touch sensor of claim 1, wherein the conductive capping pattern covers sidewalls and an upper surface of the sensing electrode.
The touch sensor of claim 1, wherein a width of the conductive capping pattern increases toward the base layer.
The method according to claim 1,
An insulating layer covering the sensing electrodes; And
Further comprising a bridge pattern penetrating the insulating layer and electrically connecting the neighboring sensing electrodes of the sensing electrodes,
And the bridge pattern is in contact with the conductive capping pattern.
The touch sensor of claim 1, further comprising a pad connecting the sensing electrodes and an external circuit to each other.
The touch sensor of claim 8, wherein the pad includes a first transparent conductive oxide pattern, a metal pattern, and a second transparent conductive oxide pattern of the same material as the sensing electrode.
The touch sensor of claim 8, wherein the conductive capping pattern comprises a first conductive capping pattern covering the sensing electrode and a second conductive capping pattern covering the pad.
The touch sensor of claim 10, further comprising a passivation layer having a contact hole exposing a top surface of the second conductive capping pattern.
The touch sensor of claim 11, wherein the external circuit contacts the second conductive capping pattern through the contact hole.
The touch sensor of claim 1, wherein the base layer comprises at least one intermediate layer comprising an organic polymer.
Base layer;
A plurality of sensing electrodes arranged on the base layer; And
It includes a bridge pattern for electrically connecting the neighboring sensing electrodes of the sensing electrodes,
At least one of the sensing electrode or the bridge pattern has a laminated structure including a first transparent conductive oxide pattern, a metal pattern, and a second transparent conductive oxide pattern, which are sequentially disposed, covering the surface of the laminated structure and forming indium tin oxide ( ITO) or a touch sensor comprising a conductive capping pattern comprising indium zinc oxide (IZO).
delete The image display apparatus containing the touch sensor of any one of Claims 1-14.

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