KR20210081673A - Touch sensor, window stack structure including the same and image display device including the same - Google Patents

Abstract

According to the embodiments of the present invention, a touch sensor includes: a base layer; sensing electrodes arranged on the base layer; and a bridge electrode which electrically connects some adjacent sensing electrodes among the sensing electrodes to each other, and includes a metal pattern and an anti-reflection pattern having a higher chromaticity than the metal pattern. Through the anti-reflection pattern, light reflection and visibility can be lowered while maintaining low resistance of the bridge electrode.

Description

A touch sensor, a window laminate including the same, and an image display device including the same {TOUCH SENSOR, WINDOW STACK STRUCTURE INCLUDING THE SAME AND IMAGE DISPLAY DEVICE INCLUDING THE SAME}

The present invention relates to a touch sensor, a window laminate including the same, and an image display device including the same. More particularly, it relates to a touch sensor including a patterned sensing electrode, a window laminate including the same, and an image display device including the same.

With the recent development of the information society, demands for the display field are also presented in various forms. For example, various flat panel display devices with features such as thinness, light weight, 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 are being studied.

On the other hand, a touch panel or a touch sensor, which is an input device attached to the display device to input a user command by selecting instructions displayed on the screen with a human hand or an object, is combined with the display device to provide an image display function and Electronic devices in which an information input function is implemented are being developed.

The touch sensor may be stacked on a display panel, and when electrode patterns of the touch sensor are recognized by a user, image quality of the display device may be deteriorated. In addition, when air or moisture penetrates during the manufacturing process of the touch sensor or from the outside of the display device, damage such as corrosion or oxidation of the electrode may occur.

For example, as in Korean Patent Application Laid-Open 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, a touch sensor with improved optical and chemical stability of the electrode. development is needed

Korea Patent Publication No. 2014-0092366

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

One object of the present invention is to provide a window laminate and an image display device including a touch sensor having improved optical, chemical, and electrical properties.

1. base layer; sensing electrodes arranged on the base layer; and a bridge electrode electrically connecting some adjacent sensing electrodes among the sensing electrodes to each other and including a metal pattern and an anti-reflection pattern having a lower brightness than the metal pattern.

2. The touch sensor of 1 above, wherein the anti-reflection pattern includes a copper-oxygen-containing conductive compound.

3. The touch sensor according to the above 2, wherein the anti-reflection pattern further contains an additional metal in addition to copper.

4. The above 1, wherein the additional metal is chromium (Cr), molybdenum (Mo), tungsten (W), magnesium (Mg), calcium (Ca), lanthanum (La), cesium (Ce) and indium (In) At least one selected from the group consisting of, a touch sensor.

5. The above 1, wherein the metal pattern 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) , Calcium (Ca), including at least one selected from the group consisting of tin (Sn) and alloys thereof, a touch sensor.

6. The touch sensor of 1 above, wherein the sensing electrodes include a transparent conductive oxide.

7. The touch sensor of 1 above, wherein the sensing electrodes include a multilayer structure of a transparent conductive oxide layer and a metal layer.

8. The touch sensor of 7 above, wherein the sensing electrodes include a first transparent conductive oxide layer, the metal layer, and a second transparent conductive oxide layer sequentially stacked from the base layer.

9. The method of 1 above, wherein the sensing electrodes include: first sensing electrodes forming a sensing channel row; and second sensing electrodes forming a sensing channel column,

The bridge electrode electrically connects the second sensing electrodes adjacent to each other in a column direction, a touch sensor.

10. The method of 9 above, further comprising an insulating layer covering the sensing electrodes on the base layer and including contact holes for partially exposing surfaces of the second sensing electrodes,

The metal pattern of the bridge electrode completely fills the contact holes on the insulating layer, and the anti-reflection pattern is formed on the metal pattern.

11. The touch sensor according to 9 above, wherein the sensing channel row includes a connection unit for integrally connecting the neighboring first sensing electrodes.

12. The touch sensor of 1 above, wherein the anti-reflection pattern includes a blackening layer.

13. The touch sensor according to the above 1, wherein the L* value of the anti-reflection pattern is 12 to 20, and the L* value of the metal pattern is 55 to 65 in the CIELAB color space.

14. Window substrate; and a touch sensor laminated on the window substrate according to any one of 1 to 13 above.

15. Display panel; and a touch sensor stacked on the display panel according to any one of 1 to 13 above.

A touch sensor according to embodiments of the present invention may include, for example, a transparent sensing electrode, and a bridge electrode connecting the transparent sensing electrode may include a stacked structure of a metal pattern and an anti-reflection pattern. Accordingly, it is possible to reduce the visibility of the bridge electrode by reducing the reflectance of the bridge electrode through the anti-reflection pattern while reducing the contact resistance or the channel resistance through the metal pattern.

The anti-reflection pattern includes, for example, a metal-oxygen complex, and may be provided as an anti-oxidation layer of the metal pattern. Accordingly, the overall reliability of the touch sensor may be improved by improving the chemical stability of the bridge electrode.

1 and 2 are schematic plan and cross-sectional views illustrating a touch sensor according to example embodiments.
3 is a schematic cross-sectional view illustrating a touch sensor according to some exemplary embodiments.
4 is a schematic cross-sectional view illustrating a window laminate and an image display device according to example embodiments.

Embodiments of the present invention include a bridge electrode having a laminated structure of a metal pattern and an anti-reflection pattern, and provide a touch sensor with improved optical, electrical, and chemical stability. In addition, there is provided an image display device including the touch sensor and improved image quality.

Hereinafter, with reference to the drawings, embodiments of the present invention will be described in more detail. However, the following drawings attached to the present specification illustrate preferred embodiments of the present invention, and serve to further understand the technical spirit of the present invention together with the above-described content of the present invention, so the present invention is described in such drawings It should not be construed as being limited only to the matters.

Terms such as "row direction", "column direction", "X direction", and "Y direction" used in this application do not designate an absolute direction, but are used to relatively express different directions.

1 and 2 are schematic plan and cross-sectional views illustrating a touch sensor according to example embodiments. Specifically, FIG. 2 is a cross-sectional view taken along the line I-I' of FIG. 1 in the thickness direction. 2 exemplarily illustrates a touch sensor having a top-bridge structure.

1 and 2 , the touch sensor 100 may include a base layer 105 and sensing electrodes 110 and 120 arranged on the base layer 105 .

The substrate layer 105 is used to encompass a film-type substrate used as a support layer for forming the sensing electrodes 110 and 120 or an object on which the sensing electrodes 110 and 120 are formed. In some embodiments, the base layer 105 may refer to a display panel in which the sensing electrodes 110 and 120 are directly formed.

For example, the base layer 105 may include a substrate or a film material commonly used in a touch sensor without particular limitation, for example, it may include glass, a polymer, and/or an inorganic insulating material. Examples of the polymer include cyclic olefin polymer (COP), polyethylene terephthalate (PET), polyacrylate (PAR), polyetherimide (PEI), polyethylene naphthalate (PEN), polyphenylene sulfide (PPS), poly Allylate, polyimide (PI), cellulose acetate propionate (CAP), polyethersulfone (PES), cellulose triacetate (TAC), polycarbonate (PC), cyclic olefin copolymer (COC), poly Methyl methacrylate (PMMA), etc. are mentioned. Examples of the inorganic insulating material include silicon oxide, silicon nitride, silicon oxynitride, and metal oxide.

In one embodiment, the base layer 105 may have a multi-layer structure. For example, it may include a multilayer structure of an organic insulating layer and an inorganic insulating layer.

A layer or a film member of the image display device into which the touch sensor is inserted may be provided as the base layer 105 . For example, an encapsulation layer or a passivation layer included in the display panel may be provided as the base layer 105 .

The sensing electrodes 110 and 120 may include first sensing electrodes 110 and second sensing electrodes 120 . For example, the sensing electrodes 110 and 120 may be arranged to be driven in a mutual capacitance method.

The first sensing electrodes 110 may be arranged, for example, in a row direction (or X direction). The first sensing electrodes 110 adjacent in the row direction may be connected to each other by a connection unit 115 . The first sensing electrodes 110 and the connection part 115 may be integrally connected to each other and may be provided as a substantially single member. In this case, the first sensing electrodes 110 and the connection part 115 may be patterned together from the same conductive film and positioned on the same layer or on the same level.

Accordingly, a first sensing channel row extending in the row direction may be defined, and a plurality of first sensing channel rows may be arranged along a column direction (eg, a Y direction).

The second sensing electrodes 120 may, for example, be arranged along the column direction and have an independent island pattern shape. The second sensing electrodes 120 adjacent in the column direction may be electrically connected to each other by the bridge electrode 140 .

Accordingly, a second sensing channel column extending in the column direction may be defined, and a plurality of second sensing channel columns may be arranged along the row direction.

In example embodiments, the sensing electrodes 110 and 120 may include a transparent conductive oxide. For example, the sensing electrodes 110 and 120 include indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium zinc tin oxide (IZTO), cadmium tin oxide (CTO), and the like. can do.

By forming the sensing electrodes 110 and 120 to include the transparent conductive oxide, the overall transmittance of the touch sensor 100 may be improved.

In some embodiments, the sensing electrodes 110 and 120 may be formed in a mesh structure including the transparent conductive oxide.

The second sensing electrodes 120 adjacent to each other with the connection part 115 included in the first sensing channel row therebetween may be electrically connected to each other by the bridge electrode 140 .

For example, the insulating layer 130 covering the sensing electrodes 110 and 120 may be formed on the base layer 105 . The insulating layer 130 may include a contact hole 135 partially exposing a top surface of the second sensing electrode 120 . The bridge electrode 140 may be formed on the insulating layer 130 while filling the adjacent contact holes 135 .

According to example embodiments, the bridge electrode 140 may include a stacked structure of a metal pattern 142 and an anti-reflection pattern 144 .

The metal pattern 142 may substantially completely fill the contact hole 135 and may contact the upper surface of the second sensing electrode 120 . The metal pattern 142 may include silver (Ag), gold (Au), copper (Cu), aluminum (Al), platinum (Pt), palladium (Pd), chromium (Cr), titanium (Ti), and tungsten (W). , niobium (Nb), tantalum (Ta), vanadium (V), iron (Fe), manganese (Mn), cobalt (Co), nickel (Ni), zinc (Zn), molybdenum (Mo), calcium (Ca) , tin (Sn) or an alloy thereof (eg, silver-palladium-copper (APC)).

A contact resistance with the second sensing electrode 120 may be decreased by the metal pattern 142 , and a channel resistance of the second sensing channel column may be decreased. Accordingly, the scanning speed or the sensing speed through the second sensing channel column may be improved.

Preferably, the metal pattern 142 may include a copper alloy to realize low resistance.

The anti-reflection pattern 144 may be formed on the metal pattern 142 to face, for example, a touch sensor or a viewing surface of an image display device. The anti-reflection pattern 144 may have a lower reflectance or higher light absorption than the metal pattern 142 .

In example embodiments, the anti-reflection pattern 144 may have a lower brightness value than the metal pattern 142 , and may be provided as a substantially blackening pattern.

In some embodiments, the L* value of the anti-reflection pattern 144 may be about 12 to 20, and the L* value of the metal pattern 142 may be about 55 to 65 in the CIELAB color space (0:Black < L) ^* <100:White; the ^{lower the value of L *,} the closer the color of Black).

In example embodiments, the anti-reflection pattern 144 may include a copper-oxygen (Cu-O)-containing conductive compound. In some embodiments, the anti-reflection pattern 144 may include a copper-additional metal-oxygen (Cu-M-O) containing conductive compound.

For example, the additional metal (M) may include a Group 6 element metal, an alkali metal, an alkaline earth metal and/or a rare earth metal. For example, additional metals (M) include chromium (Cr), molybdenum (Mo), tungsten (W), magnesium (Mg), calcium (Ca), lanthanum (La), cesium (Ce), indium (In), etc. may include. These may be used alone or in combination of two or more.

In some embodiments, the ratio of the copper, the additional metal (M), and the oxygen element among the total elements included in the anti-reflection pattern 144 may be about 50 to 80 atomic% (at%), preferably may be about 60 to 70 atomic% (at%).

In the anti-reflection pattern 144 , elemental oxygen may be doped or incorporated into the anti-reflection pattern 144 without losing the conductivity of the copper and/or additional metal (M). The antireflection pattern 144 may be blackened or partially oxidized by the oxygen element to provide an antireflection layer or a light absorption layer for the metal pattern 142 .

For example, after a metal layer filling the contact holes 135 is formed in the insulating layer 130 , an antireflection layer may be formed on the metal layer. The anti-reflection layer may be formed through a sputtering process using a copper target (or copper-oxygen target) and an additional metal target (or additional metal-oxygen target), or a copper-addition metal-oxygen target.

Thereafter, the anti-reflection layer and the metal layer may be etched to form the bridge electrode 140 including the metal pattern 142 and the anti-reflection pattern 144 sequentially stacked from the insulating layer 130 .

A passivation layer 150 covering the bridge electrode 140 may be further formed on the insulating layer 130 . The insulating layer 130 and the passivation layer 150 may include an inorganic insulating material such as silicon oxide or silicon nitride, or an organic insulating material such as an acrylic resin or a siloxane-based resin.

According to the above-described exemplary embodiments, the transmittance of the touch sensor 100 may be improved by forming the sensing electrodes 110 and 120 of a transparent conductive oxide. To reduce channel resistance, the bridge electrode 140 may include a metal pattern 142 .

In this case, the bridge electrode 140 may be visually recognized by the user due to light reflection from the metal pattern 142 . However, in embodiments of the present invention, since the anti-reflection pattern 144 covers the bridge electrode 140 , light reflection may be blocked or the reflected light may be absorbed to suppress visibility of the bridge electrode 140 . .

In addition, the surface of the metal pattern 142 is protected by the anti-reflection pattern 144 to prevent oxidation and corrosion of the metal pattern 142 by the touch sensor manufacturing process or moisture and air penetrating from the outside. Accordingly, the chemical stability and electrical reliability of the bridge electrode 140 may be maintained for a long period of time.

3 is a schematic cross-sectional view illustrating a touch sensor according to some exemplary embodiments. Detailed descriptions of configurations and structures substantially the same as or similar to those described with reference to FIGS. 1 and 2 will be omitted.

Referring to FIG. 3 , the sensing electrodes 110 and 120 may include a multilayer structure of a metal layer and a transparent conductive oxide layer.

In some embodiments, each of the sensing electrodes 110 and 120 may have a multilayer structure including a first transparent conductive oxide layer 92 , a metal layer 94 , and a second transparent conductive oxide layer 96 .

The metal layer 94 may be formed between the first and second transparent conductive oxide layers 92 and 96 to lower the resistance of the sensing electrodes 110 and 120 and promote capacitance formation. In addition, the overall flexible characteristics of the touch sensor 100 may be increased by the metal layer 94 .

Since the metal layer 94 is sandwiched by the first and second transparent conductive oxide layers 92 and 96, corrosion by external air and moisture can be prevented. In addition, the sensing electrodes 110 and 120 may have substantially transparency due to the first and second transparent conductive oxide layers 92 and 96 .

4 is a schematic cross-sectional view illustrating a window laminate and an image display device according to example embodiments.

Referring to FIG. 4 , the window stack 200 may include the window substrate 230 , the polarization layer 220 , and the touch sensor 100 according to the above-described exemplary embodiments.

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

The polarizing layer 220 may include a coated polarizer or a polarizing plate. The coating-type polarizer may include a liquid crystal coating layer including a polymerizable liquid crystal compound and a dichroic dye. In this case, the polarizing layer 220 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 220 may be directly bonded to the one surface of the window substrate 230 or may be attached through the first adhesive layer 240 .

The touch sensor 100 may be included in the window laminate 200 in the form of a film or a panel. In an embodiment, the touch sensor 100 may be coupled to the polarization layer 220 through the second adhesive layer 250 .

As shown in FIG. 4 , the window substrate 230 , the polarization layer 220 , and the touch sensor 100 may be sequentially disposed from the user's viewing side. In this case, since the sensing electrodes of the touch sensor 100 are disposed under the polarization layer 220, it is possible to more effectively prevent the electrode visibility phenomenon.

When the touch sensor 100 includes a substrate (eg, the substrate layer 105), the substrate includes, for example, triacetyl cellulose, cycloolefin, cycloolefin copolymer, polynorbornene copolymer, etc. and preferably, the front retardation may be ±2.5 nm or less.

In an embodiment, the touch sensor 100 may be directly transferred onto the window substrate 230 or the polarization layer 220 . In an embodiment, the window substrate 230 , the touch sensor 100 , and the polarization layer 220 may be disposed in the order from the user's viewing side.

The image display device may include a display panel 300 and the above-described window stack 200 coupled to the display panel 300 .

The display panel 300 may include a pixel electrode 310 , a pixel defining layer 320 , a display layer 330 , a counter electrode 340 , and an encapsulation layer 350 disposed on a panel substrate 305 . can

A pixel circuit including a thin film transistor (TFT) may be formed on the panel substrate 305 , and an insulating layer covering the pixel circuit may be formed. The pixel electrode 310 may be electrically connected to, for example, a drain electrode of a TFT on the insulating layer.

The pixel defining layer 320 may be formed on the insulating layer to expose the pixel electrode 310 to define a pixel area. A 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 light emitting layer.

A 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 a common electrode or a cathode of the image display device. An encapsulation layer 350 for protecting the display panel 300 may be stacked on the opposite electrode 340 .

In some embodiments, the display panel 300 and the window stack 200 may be coupled through an adhesive layer 260 . For example, the thickness of the adhesive layer 260 may be greater than the thickness of each of the first and second adhesive layers 240 and 250, and the viscoelasticity at -20 to 80° C. may be about 0.2 MPa or less. In this case, noise from the display panel 300 may be shielded, and interfacial stress may be relieved during bending to suppress damage to the window laminate 200 . In one embodiment, the viscoelasticity may be about 0.01 to 0.15 MPa.

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

Experimental example

Example 1

An electrode structure was prepared by forming a Cu layer to a thickness of 1000 Å on a COP substrate (thickness: 1000 Å), and forming a copper-oxygen-containing antireflection layer on the Cu layer to a thickness of 400 Å through a sputtering process.

Comparative Example 1

An electrode structure was prepared in the same manner as in Example 1, except that the anti-reflection layer was omitted.

Comparative Example 2

An electrode structure was prepared in the same manner as in Example 1, except that an indium zinc oxide (IZO) layer was formed on the Cu layer to a thickness of 300 Å instead of the anti-reflection layer.

The visible light reflectance on the electrode surface of the electrode structures of Examples and Comparative Examples was measured (measuring device: Minolta integrating sphere meter).

The initial resistance was measured at room temperature for the electrode structures of Examples and Comparative Examples. Thereafter, the resistance of the electrode structure was measured after leaving it in the 85% relative humidity condition at 85°C for 24 hours, and the resistance change rate compared to the initial resistance was measured.

The evaluation results are shown in Table 1 below.

Example Comparative Example 1 Comparative Example 2 reflectivity
(%) 2.5 74.9 71.4 Resistance change rate (%) 109.6 1154.7 99.4

Referring to Table 1, in the case of the embodiment in which the anti-reflection layer is formed on the Cu layer, it can be confirmed that the reflectance of the electrode structure is significantly lowered and chemical and electrical stability in high temperature and high humidity conditions is maintained.

105: base layer 110: first sensing electrode
115: connection unit 120: second sensing electrode
130: insulating layer 140: bridge electrode
142: metal pattern 144: anti-reflection pattern
150: passivation layer

Claims (15)

base layer;
sensing electrodes arranged on the base layer; and
A touch sensor that electrically connects some adjacent sensing electrodes among the sensing electrodes to each other and includes a bridge electrode including a metal pattern and an anti-reflection pattern having a lower brightness than the metal pattern. The touch sensor of claim 1 , wherein the anti-reflection pattern includes a copper-oxygen-containing conductive compound. The touch sensor of claim 2 , wherein the anti-reflection pattern further contains an additional metal in addition to copper. The method according to claim 1, wherein the additional metal is composed of chromium (Cr), molybdenum (Mo), tungsten (W), magnesium (Mg), calcium (Ca), lanthanum (La), cesium (Ce) and indium (In) A touch sensor comprising at least one selected from the group. The method according to claim 1, wherein the metal pattern 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), calcium (Ca), comprising at least one selected from the group consisting of tin (Sn) and alloys thereof, a touch sensor. The touch sensor of claim 1 , wherein the sensing electrodes include a transparent conductive oxide. The touch sensor of claim 1 , wherein the sensing electrodes include a multilayer structure of a transparent conductive oxide layer and a metal layer. The touch sensor of claim 7 , wherein the sensing electrodes include a first transparent conductive oxide layer, the metal layer and a second transparent conductive oxide layer sequentially stacked from the base layer. The method according to claim 1, wherein the sensing electrodes are first sensing electrodes forming a sensing channel row; and second sensing electrodes forming a sensing channel column,
The bridge electrode electrically connects the second sensing electrodes adjacent to each other in a column direction, a touch sensor. The method according to claim 9, further comprising an insulating layer covering the sensing electrodes on the base layer and including contact holes partially exposing surfaces of the second sensing electrodes,
The metal pattern of the bridge electrode completely fills the contact holes on the insulating layer, and the anti-reflection pattern is formed on the metal pattern. The touch sensor of claim 9 , wherein the sensing channel row includes a connection unit for integrally connecting the adjacent first sensing electrodes. The touch sensor of claim 1 , wherein the anti-reflection pattern includes a blackening layer. The touch sensor of claim 1 , wherein the L* value of the anti-reflection pattern is 12 to 20, and the L* value of the metal pattern is 55 to 65 in the CIELAB color space. window substrate; and
A window laminate stacked on the window substrate and comprising the touch sensor according to claim 1 . display panel; and
An image display device stacked on the display panel and including the touch sensor according to claim 1 .

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