KR102175102B1 - Touch sensor and image display device including the same - Google Patents

Abstract

The touch sensor of the embodiments of the present invention is electrically connected to each sensing electrode on a base layer, a plurality of sensing electrodes that are independently spaced apart and arranged on the base layer, and the sensing electrodes apart from the sensing electrodes, It includes wirings that overlap and extend on the same plane as the sensing electrodes. By arranging the wires to overlap the sensing electrodes, the inactive area may be reduced.

Description

A touch sensor and an image display device including the same TECHNICAL FIELD

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

With the recent development of the information society, demands for the display field have also been presented in various forms. For example, various flat panel display devices with features such as reduction in thickness, weight, and low power consumption, for example, a liquid crystal display device, a plasma display panel device, Research is being conducted on an electroluminescent display device and an organic light-emitting diode display device.

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

In addition, as the resolution of the display device is improved to a level such as QHD (Quad High Definition) and UHD (Ultra High Definition), the resolution and sensing sensitivity of the touch sensor also need to be increased.

In order to improve the sensing sensitivity of the touch sensor, the number of sensing electrodes per unit area may be increased, and in this case, the number of wirings (or traces) connected to each sensing electrode may be increased. Accordingly, as the number of wires increases, the area in which the sensing electrode can be formed may be decreased, and touch sensing failure may be caused due to an increase in the non-sensing area (inactive area).

For example, as in Korean Patent Laid-Open No. 2014-0092366, a touch screen panel in which a touch sensor is combined with various image display devices has been recently developed, but as described above, the demand for a touch sensor or touch panel having high integration and high resolution. Is going on.

Korean Patent Publication No. 2014-0092366

An object of the present invention is to provide a touch sensor having improved resolution and sensitivity.

An object of the present invention is to provide an image display device including a touch sensor having improved resolution and sensitivity.

1. Base layer; A plurality of sensing electrodes each independently spaced apart and arranged on the base layer; And wires spaced apart from the sensing electrodes and electrically connected to each of the sensing electrodes on the sensing electrodes, overlapping and extending on the same plane as the sensing electrodes.

2. The touch sensor according to 1 above, further comprising an insulating layer covering the sensing electrodes, wherein the wires are disposed on the insulating layer.

3. The touch sensor of 2 above, further comprising contacts penetrating the insulating layer and connecting the sensing electrode and the wire to each other.

4. The touch sensor according to 2 above, wherein an opening penetrating through a portion of the insulating layer formed at one end of the base layer is formed, and ends of the wires are exposed through the opening.

5. The touch sensor of 4 above, further comprising a pad layer formed on the ends of the wires exposed through the opening.

6. In 4 above, further comprising a passivation layer formed on the insulating layer to cover the wirings,

The openings pass through the passivation layer together.

7. In the above 1, a sensing electrode row is defined by the sensing electrodes arranged in a first direction parallel to the upper surface of the base layer and the wires connected to the sensing electrodes, and a plurality of sensing electrodes Columns are arranged along a second direction parallel to the upper surface of the base layer and crossing the first direction.

8. In the above 7, the wirings included in each of the sensing electrode rows are repeated in the same arrangement and structure, the touch sensor,

9. The touch sensor according to the above 7, wherein the wirings included in the adjacent sensing electrode rows are arranged in a mirror image with each other.

10. The touch sensor according to the above 7, wherein the wires included in each of the sensing electrode rows are arranged in a width of the sensing electrode row on a plane.

11. The touch sensor according to the above 7, wherein the wires extend in a straight line in the first direction.

12. In the above 1, the self-capacitive touch sensor.

13. An image display device comprising the touch sensor of any one of 1 to 12 above.

A touch sensor according to embodiments of the present invention includes a plurality of sensing electrodes and wirings disposed above the sensing electrodes to overlap the sensing electrodes. Since the wires are disposed on a different layer or level than the sensing electrodes, the degree of integration of the sensing electrodes per unit area may be improved, and the area of the non-active area may be reduced.

In addition, since wires are excluded between adjacent sensing electrodes and the spacing between sensing electrodes is reduced, even if a multi-touch or drawing touch is input, a high-resolution sensing operation can be implemented without disconnection or defect of a sensing signal. .

1 and 2 are schematic plan and cross-sectional views for describing a touch sensor according to exemplary embodiments, respectively.
3A to 3E are schematic plan views illustrating a shape of a sensing electrode included in a touch sensor according to exemplary embodiments.
4 is a schematic plan view illustrating a touch sensor according to a comparative example.
5 is a schematic plan view illustrating a touch sensor according to some exemplary embodiments.
6 is a schematic cross-sectional view illustrating a pad connection area of a touch sensor according to example embodiments.

Embodiments of the present invention provide a touch sensor including a plurality of sensing electrodes and wires disposed above the sensing electrodes so as to overlap the sensing electrodes, and with improved sensing sensitivity and sensing reliability. In addition, an image display device including the touch sensor is provided.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings. However, the following drawings attached to the present specification 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, so the present invention is described in such drawings. It is limited to matters and should not be interpreted.

In the drawings below, two directions that are parallel to the same plane (eg, the upper surface of the substrate layer) and cross each other perpendicularly to each other are defined as a first direction and a second direction, respectively.

1 and 2 are schematic plan and cross-sectional views, respectively, for describing a touch sensor according to exemplary embodiments.

Specifically, FIG. 2 is a cross-sectional view taken along the line II′ of FIG. 1 in the thickness direction of the touch sensor. In FIG. 1 for convenience of explanation, the insulating layer 140 and the passivation layer 150 illustrated in FIG. 2 are omitted.

1 and 2, the touch sensor includes sensing electrodes 110 (110a, 110b, 110c, 110d) and wires 130 (130a, 130b, 130c, 130d) arranged on the base layer 100 It may include.

The substrate layer 100 may be a substrate or film material commonly used for a touch sensor without particular limitation, and may include, for example, 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 (polyallylate), polyimide (PI), cellulose acetate propionate (CAP), polyethersulfone (PES), cellulose triacetate (TAC), polycarbonate (PC), cyclic olefin copolymer (COC), poly Methyl methacrylate (PMMA), and the like. Examples of the inorganic insulating material include silicon oxide, silicon nitride, silicon oxynitride, and metal oxide.

In some embodiments, the base layer 100 may mean a display panel of a display device on which a touch sensor is stacked. In addition, the base layer 100 may mean an optical layer or an optical film included in the display device, such as a retarder, a polarizing plate, and a hard coating layer.

The sensing electrodes 110 are arranged on the upper surface of the base layer 100 and may each have a physically separated island pattern shape. The wirings 130 may be electrically and independently connected from each of the sensing electrodes 110.

For example, as shown in FIG. 1, each sensing electrode 110 may have a rectangular pattern shape.

As shown in FIG. 1, a plurality of sensing electrodes 110 are arranged in the first direction to form a sensing electrode row, and a plurality of sensing electrode rows may be arranged in the second direction.

For example, the first to fourth sensing electrodes 110a to 110d may be arranged along the first direction to form the sensing electrode row, and the number of sensing electrodes 110 included in the sensing electrode row Can be extended further.

The sensing electrode 110 may include a transparent conductive oxide or a metal. The transparent conductive oxide may include, for example, indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium zinc tin oxide (IZTO), cadmium tin oxide (CTO), and the like. The metal is, for example, 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), or alloys thereof have.

In some embodiments, the sensing electrode 110 may be formed to include the transparent conductive oxide in order to secure the transparency or transmittance of the sensing electrode 110. In some embodiments, the sensing electrode 110 may be formed in a multilayer structure of a transparent conductive oxide layer and a metal layer for low resistance and sensing sensitivity of the sensing electrode.

The sensing electrode 110 forms the first conductive layer including the above-described transparent conductive oxide and/or metal on the base layer 100, and then, the first conduction through a patterning process using, for example, a photolithography process. The sensing electrode 110 may be formed from the layer.

According to exemplary embodiments, the sensing electrodes 110 are substantially simultaneously formed through a single patterning process, and may be distributed on the same layer or level.

According to exemplary embodiments, the wires 130 are electrically connected to each of the sensing electrodes 110 and may extend from the sensing electrode 110 in the first direction.

As illustrated in FIG. 2, an insulating layer 140 may be formed on the base layer 100 to cover the sensing electrodes 110. The insulating layer 140 may include an inorganic insulating material such as silicon oxide or silicon nitride, and/or an organic insulating material such as an acrylic resin or a siloxane resin.

The wirings 130 may be electrically connected to each sensing electrode 110 through contacts 120 (120a, 120b, 120c, and 120d).

For example, a contact hole may be formed in the insulating layer 140 to partially expose the upper surface of each sensing electrode 110. After forming a second conductive layer filling the contact hole on the insulating layer 140, the second conductive layer may be patterned in a line shape to form the wirings 130. In this case, the wirings 130 and the contacts 120 may be substantially formed as a single member through a single etching process.

The second conductive layer may be formed to include a low-resistance metal (eg, metal such as silver, copper, palladium, and alloys thereof) to improve signal transmission speed. In some embodiments, the second conductive layer may be formed to include a transparent conductive oxide.

As shown in FIG. 1, in one sensing electrode row, the first sensing electrode 110a, the second sensing electrode 110b, the third sensing electrode 110c, and the fourth sensing electrode 110d It extends toward the pad connection area PC disposed at the distal end of the touch sensor in a direction and may be sequentially disposed along the second direction. The first wiring 130a, the second wiring 130b, the third wiring 130c, and the fourth wiring 130d are respectively a first contact 120a, a second contact 120b, a third contact 120c, and The first sensing electrode 110a, the second sensing electrode 110b, the third sensing electrode 110c, and the fourth sensing electrode 110d may be respectively connected through the fourth contact 120d.

In some embodiments, the length of the single sensing electrode row may be shorter as it goes in the second direction (eg, from the first wiring 130a to the fourth wiring 130d).

The sensing electrode row including the wirings 130 and the contacts 120 described above may be repeated in the same structure along the second direction.

The wires 130 may be formed to overlap the sensing electrode row in the thickness direction of the touch sensor. For example, the wires 130 may extend only in the first direction (eg, in a straight line) and may not bend or branch in other directions.

In some embodiments, the wires 130 may not protrude outside the sensing electrodes 110 in the second direction in a planar direction. For example, the wirings 130 may not exist in a region between adjacent sensing electrode columns.

A wiring group is defined by the wirings 130 included in one sensing electrode row, and a plane width occupied by the wiring group may be smaller than a plane width occupied by the sensing electrode row.

Each of the wiring groups may extend in the first direction to be connected to a pad or an external circuit connection structure in the wiring connection area PC.

In some embodiments, a passivation layer 150 may be further formed to protect the contacts 120 and wires 130. The passivation layer 150 may be formed on the insulating layer 140 to cover the contacts 120 and the wires 130.

For example, the passivation layer 150 may include an inorganic insulating material such as silicon oxide or silicon nitride, and/or an organic insulating material such as an acrylic resin or a siloxane resin.

According to the above-described exemplary embodiments, the sensing electrodes 110 and the wires 130 may be formed to overlap each other on different layers or different levels using the insulating layer 140. Accordingly, by minimizing the horizontal separation distance between the sensing electrodes 110, the area of the non-active area in which the sensing electrodes are not included can be significantly reduced.

Therefore, sensing sensitivity and resolution may be increased, and continuity and reliability of touch signal transmission may be improved.

The touch sensor according to example embodiments may be a self-capacitance type touch sensor in which each sensing electrode 110 is independently disposed in an island shape and provided as a sensing domain.

Therefore, for example, compared to a mutual capacitance type touch sensor in which a plurality of sensing electrodes are connected to each other and are arranged to cross in the X and Y directions, the magnitude of signal interference and signal noise may be reduced.

3A to 3E are schematic plan views illustrating a shape of a sensing electrode included in a touch sensor according to exemplary embodiments.

In FIG. 1, for convenience of description, each sensing electrode 110 is illustrated in a rectangular pattern, but is not limited thereto and may be patterned in various polygonal shapes.

For example, as shown in FIG. 3A, the sensing electrode 111 may have a rhombus pattern shape. As shown in FIG. 3B, the sensing electrode 112 may have a hexagonal pattern shape. As shown in FIG. 3C, the sensing electrode 113 may have a circular (or elliptical) pattern shape.

In some embodiments, the sensing electrode may have a structure in which polygonal patterns or circular patterns are combined or alternately arranged.

For example, as shown in FIG. 3D, the sensing electrode 114 may have a pattern shape in which a plurality of polygonal units are combined. 3E, the sensing electrode 115 includes a polygonal pattern and a circular pattern, and the polygonal pattern and circular pattern may be alternately arranged.

4 is a schematic plan view illustrating a touch sensor according to a comparative example.

Referring to FIG. 4, the touch sensor of the comparative example includes sensing electrodes 210 (210a, 210b, 210c, 210d) arranged on the upper surface of the base layer 100, and branching from and extending from each sensing electrode 210 Includes wirings 230.

A plurality of sensing electrodes 210 may be arranged along the first direction on the base layer 100 to form a sensing electrode row, and the plurality of sensing electrode rows may be arranged to be spaced apart from each other along the second direction. .

According to the comparative example, the sensing electrodes 210 and the wires 230 are arranged together on the same plane or on the same level. Accordingly, as shown in FIG. 3, wirings 230 are disposed between neighboring sensing electrode columns to increase the area of the non-active area NA.

In the case of the touch sensor of the comparative example, when, for example, a drawing touch of a finger is input along the second direction, signal disconnection may occur as inactive regions NA exist between the sensing electrode rows. . In addition, even when a multi-touch input in which a plurality of points are touched, the sensing electrodes 210 spaced apart from each other act as domains, making it difficult to generate a single signal.

However, in the embodiments according to the exemplary embodiments described with reference to FIGS. 1 and 2, the area of the non-active area may be significantly reduced by arranging the wires so as to overlap the sensing electrode. Accordingly, according to an increase in the integration degree of the sensing electrodes, the above-described drawing touch and multi-touch can be effectively generated, as well as improved sensing sensitivity and resolution.

5 is a schematic plan view illustrating a touch sensor according to some exemplary embodiments. Detailed descriptions of the configuration and structure described with reference to FIG. 1 are omitted, and the same reference numerals are used for configurations corresponding to the configuration of FIG. 1.

Referring to FIG. 5, as described above, the wires 130 are electrically connected to the sensing electrodes 110 through the contacts 120 and may be arranged in a plane width occupied by the sensing electrode row on a plane.

In some embodiments, wiring groups belonging to neighboring sensing electrode rows may be arranged in a shape facing each other, for example, in a mirror image.

For example, the length of the wires 130 belonging to the first sensing electrode row 115a may be shorter in the second direction, and the length of the wires 130 belonging to the second sensing electrode row 115b May become longer as it goes in the second direction.

As shown in FIG. 5, by adding irregularities to the arrangement of the wirings 130, for example, suppressing the moiré phenomenon due to overlapping with the electrodes and pixel furnaces included in the display panel disposed under the touch sensor or It can be reduced.

6 is a schematic cross-sectional view illustrating a pad connection area of a touch sensor according to example embodiments. For example, FIG. 6 is a cross-sectional view taken along the line II-II' shown in FIG. 1 along the thickness direction of the touch sensor.

Referring to FIG. 6, an opening 160 exposing wirings 130 may be formed in the pad connection area PC shown in FIG. 1. For example, the opening 160 may be formed by etching a portion of the insulating layer 140 of the pad connection region PC. In some embodiments, the opening 160 may be formed by etching portions of the passivation layer 150 and the insulating layer 140 together in the pad connection region PC.

As shown in FIG. 6, the openings 160 may be formed to correspond to each wiring group. Alternatively, the opening 160 may be formed to cover two or more wiring groups.

An external circuit connection structure such as, for example, a flexible circuit board (FPCB) may be electrically connected to the wirings 130 through the opening 160 in the pad connection area PA.

In some embodiments, an intermediate conductive structure such as an anisotropic conductive film or conductive paste is formed to fill the opening 160 and connected to the wirings 130, and the flexible circuit board may be attached on the intermediate conductive structure. have.

The wires 130 may extend along a sidewall of the insulating layer 140 exposed by the opening 160 and an upper surface of the base layer 100 on the pad connection area PC. Therefore, although the wirings 130 are located at the upper level of the sensing electrodes 110 in the sensing area or the active area, the wirings 130 are at the same level as the sensing electrodes 110 through the opening 160 on the pad connection area PC. Can be located in

Accordingly, when the external circuit connection structure is connected, bonding reliability may be improved by increasing the contact area through the sidewall of the opening 160, and the thickness of the touch sensor may be further reduced.

In some embodiments, a pad layer 135 including a metal may be formed on portions of the wires 130 exposed through the opening 160. For example, when the wiring 130 includes a transparent conductive oxide such as ITO, a pad layer 135 including a metal may be further formed to prevent connection resistance with the flexible circuit board and facilitate the alignment process. I can.

For example, the pad layer 135 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), or alloys thereof Can include.

Embodiments of the present invention provide an image display device including the above-described touch sensor. For example, the touch sensor may be inserted between a window and a display panel of an image display device.

The display panel may include, for example, a liquid crystal display (LCD) panel or an organic electroluminescent display (OLED) panel. For example, the display panel may include a pixel circuit including a thin film transistor TFT and a pixel portion connected to the pixel circuit. The pixel circuit may include electrodes and wirings such as data lines, scan lines, and driving lines that are regularly arranged according to the arrangement of pixel units. The pixel portion includes a liquid crystal device or an OLED device, and may include a pixel electrode and a counter electrode.

Even when the image display device is miniaturized through the arrangement or configuration of sensing electrodes and wires of the touch sensor according to the exemplary embodiments described above, high resolution and high sensitivity sensing by reducing the area of the inactive area by the wires Function can be implemented.

100: base layer 110: sensing electrode
120: contact 130: wiring
135: pad layer 140: insulating layer
150: passivation layer 160: opening

Claims (13)

Base layer;
A plurality of sensing electrodes each independently spaced apart and arranged on the base layer;
An insulating layer formed on the base layer to cover the sensing electrodes; And
It is disposed on the insulating layer, is spaced apart from the sensing electrodes, is electrically connected to each of the sensing electrodes above the sensing electrodes, and includes wires that overlap and extend with the sensing electrodes when projected in a plane direction,
The insulating layer includes an opening exposing ends of the wires, and the wires extend along an upper surface of the insulating layer, a sidewall of the insulating layer exposed by the opening, and an upper surface of the base layer. The ends are located at the same level as the sensing electrodes,
The sensing electrodes and wirings include a transparent conductive oxide,
A touch sensor that is inserted between the window and the display panel of the image display device.
delete The touch sensor as set forth in claim 1, further comprising contacts passing through the insulating layer and connecting the sensing electrode and the wire to each other.
delete The touch sensor as set forth in claim 1, further comprising a pad layer formed on the ends of the wires exposed through the opening.
The method according to claim 1, further comprising a passivation layer formed on the insulating layer to cover the wires,
The openings pass through the passivation layer together.
The method according to claim 1, wherein a sensing electrode row is defined by the sensing electrodes arranged in a first direction parallel to the upper surface of the base layer and the wirings connected to the sensing electrodes, and a plurality of sensing electrode rows are The touch sensor, which is arranged in a second direction parallel to the upper surface of the base layer and crossing the first direction.
The touch sensor of claim 7, wherein wirings included in each of the sensing electrode rows are repeated in the same arrangement and structure,
The touch sensor as set forth in claim 7, wherein wirings included in adjacent sensing electrode rows are arranged in mirror images.
The touch sensor as set forth in claim 7, wherein the wires included in each of the sensing electrode rows are arranged within a width of the sensing electrode row when projected in a plane direction.
The touch sensor of claim 7, wherein the wires extend in a straight line in the first direction.
delete An image display device comprising the touch sensor of claim 1.

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