KR102474211B1 - Foldable display device - Google Patents

Abstract

The foldable display includes a display panel and a touch sensing unit provided on the display panel. The touch sensing unit includes a plurality of sensing electrodes for recognizing a touch. Each of the sensing electrodes includes a metal layer and a lower graphene layer provided between the metal layer and the display panel.

Description

Foldable display device {FOLDABLE DISPLAY DEVICE}

The present invention relates to a foldable display device, and more particularly, to a foldable display device in which disconnection defects due to bending are improved.

A display device provides information to a user by displaying various images on a display screen. Recently, a bendable display device is being developed. A flexible display device may be folded, rolled, or bent like a piece of paper, unlike a flat panel display device. A flexible display device that can be changed in various shapes is easy to carry and can improve user convenience.

An object of the present invention is to provide a foldable display device in which disconnection defects due to bending are improved.

A foldable display device according to an exemplary embodiment includes a display panel and a touch sensing unit provided on the display panel. The touch sensing unit includes a plurality of sensing electrodes for recognizing a touch. Each of the sensing electrodes includes a metal layer and a lower graphene layer provided between the metal layer and the display panel.

The foldable display device according to an exemplary embodiment of the present invention may further include an upper graphene layer spaced apart from the lower graphene layer and provided in contact with an upper surface of the metal layer.

The lower graphene layer may include a first lower graphene layer, a second lower graphene layer, and a third lower graphene layer. The upper graphene layer may include a first upper graphene layer, a second upper graphene layer, and a third upper graphene layer.

The foldable display device according to an exemplary embodiment of the present invention may further include an upper graphene layer provided to cover top and side surfaces of the metal layer.

The upper graphene layer may include a top graphene portion covering the top surface of the metal layer and a side graphene portion connected to the top graphene portion and covering the side surface of the metal layer.

The side surface may include a first side surface and a second side spaced apart from the first side surface. The lateral graphene part may include a first sub-graphene part covering the first side surface and a second sub-graphene part covering the second side surface.

The lower graphene layer may include a first lower graphene layer, a second lower graphene layer, and a third lower graphene layer. The upper graphene layer may include a first upper graphene layer, a second upper graphene layer, and a third upper graphene layer.

The first upper graphene layer may include a first upper graphene portion contacting the upper surface of the metal layer and a first side graphene portion contacting a side surface of the metal layer. The second upper graphene layer includes a second upper graphene portion contacting the first upper graphene portion and a second side graphene portion contacting the first side graphene portion. The third upper graphene layer may include a third upper graphene portion contacting the second upper graphene portion and a third upper graphene portion contacting the second side graphene portion.

The metal layer may define a plurality of openings and have a mesh shape.

The lower graphene layer may have a mesh shape in which a plurality of graphene openings corresponding to the respective openings of the metal layer are defined.

The foldable display according to an exemplary embodiment of the present invention may further include an upper graphene layer covering the metal layer. The upper graphene layer may include a top graphene portion covering an upper surface of the metal layer and a plurality of exposed graphene portions covering exposed surfaces exposed by the openings.

The metal layer may include at least one selected from the group consisting of Al, Cu, Mo, Ti, Ag, Mg, Pt, Pd, Au, Ni, Nd, Ir, and Cr.

The foldable display device according to an exemplary embodiment of the present invention may operate in a first mode in which at least a portion of the display panel and the touch sensing unit are bent or in a second mode in which the bending is extended.

According to the foldable display device according to an exemplary embodiment of the present invention, a disconnection defect due to bending can be improved.

1A is a schematic perspective view of a first mode of a foldable display device according to an exemplary embodiment of the present invention.
1B is a schematic perspective view of a second mode of a foldable display device according to an exemplary embodiment of the present invention.
2 is a plan view schematically illustrating a touch sensing unit included in a foldable display device according to an exemplary embodiment.
3A to 3E are schematic cross-sectional views corresponding to lines II' of FIG. 2 .
4A to 4E are schematic cross-sectional views corresponding to line II-II' of FIG. 2 .

The above objects, other objects, features and advantages of the present invention will be easily understood through the following preferred embodiments in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosed content will be thorough and complete and the spirit of the present invention will be sufficiently conveyed to those skilled in the art.

Like reference numerals have been used for like elements throughout the description of each figure. In the accompanying drawings, the dimensions of the structures are shown enlarged than actual for clarity of the present invention. Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. These terms are only used for the purpose of distinguishing one component from another. For example, a first element may be termed a second element, and similarly, a second element may be termed a first element, without departing from the scope of the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise.

In this application, the terms "include" or "have" are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that it does not preclude the possibility of the presence or addition of numbers, steps, operations, components, parts, or combinations thereof. In addition, when a part such as a layer, film, region, plate, etc. is said to be "on" another part, this includes not only the case where it is "directly on" the other part, but also the case where another part is present in the middle. Conversely, when a part such as a layer, film, region, plate, etc. is said to be "under" another part, this includes not only the case where it is "directly below" the other part, but also the case where another part is in the middle.

Hereinafter, a foldable display device according to an exemplary embodiment of the present invention will be described.

1A and 1B are schematic perspective views of a foldable display device according to an exemplary embodiment of the present invention.

Referring to FIGS. 1A and 1B , the foldable display device 10 according to an exemplary embodiment includes a display panel DP and a touch sensing unit TSU. The touch sensing unit TSU may be stacked in the first direction DR1 on the display panel DP. The foldable display 10 may operate in the first mode or the second mode. Foldable may mean a characteristic that a specific part of the display device 10 can be folded.

The display panel DP displays an image according to an electrical signal. For convenience of description below, a direction in which an image is provided from the display panel DP is defined as an upward direction, and a direction opposite to the upper direction is defined as a downward direction. The display panel DP is not particularly limited, and for example, an organic light emitting display panel, a liquid crystal display panel, a plasma display panel, an electrophoretic display panel ( An electrophoretic display panel) or an electrowetting display panel may be applied.

The display panel DP includes a panel bending portion BF1 and a panel non-bending portion NBF1. The panel bending unit BF1 is bent based on the bending axis BX1 extending in the second direction DR2 in the first mode, and the bending is unfolded in the second mode. The panel bending part BF1 is connected to the panel non-bending part NBF1. The panel non-bending part NBF1 does not bend in the first mode and the second mode. Bending may mean that the foldable display 10 or the like is bent in a specific shape by an external force.

The touch sensing unit TSU includes a touch bending part BF2 and a touch non-bending part NBF2. The touch bending part BF2 is bent based on the bending axis BX1 extending in the second direction DR2 in the first mode, and the bending is unfolded in the second mode. The touch bending part BF2 is connected to the touch non-bending part NBF2. The touch non-bending part NBF2 does not bend in the first mode and the second mode.

Referring to FIG. 1A , the foldable display 10 according to an exemplary embodiment of the present invention may be bent in one direction with respect to a bending axis BX1 in a first mode. The foldable display 10 may be inwardly bent in the first mode. When the foldable display device 10 is bent based on the bending axis BX1, the distance between the bent and facing touch sensing units TSU is shorter than the distance between the bent and facing display panels DP. The case is defined as inner bending. During inward bending, one surface of the panel bending part BF1 and the display bending part BF2 may have a first radius of curvature R1. The first radius of curvature R1 may be, for example, about 1 millimeter (mm) to about 10 millimeters (mm).

1A and 1B show, for example, that when the foldable display 10 is bent with respect to the bending axis BX1, the distance between the folded display devices 10 facing each other after being bent is constant. The present invention is not limited thereto, and the distance between the foldable display devices 10 that are bent and face each other may not be constant. 1A and 1B illustrate, for example, that when the foldable display 10 is bent with respect to the bending axis BX1, the areas of the foldable display 10 facing each other after being bent are the same. However, the present invention is not limited thereto, and the areas of the foldable display devices 10 that are bent and face each other may be different from each other.

2 is a plan view schematically illustrating a touch sensing unit included in a foldable display device according to an exemplary embodiment.

Referring to FIGS. 1A, 1B, and 2 , in the foldable display device 10 according to an exemplary embodiment of the present invention, the touch sensing unit TSU is provided on the display panel DP. The touch sensing unit TSU may recognize a user's direct touch, a user's indirect touch, a direct touch of an object, or an indirect touch of an object. Indirect touch means that even if a user or object does not directly contact the touch sensing unit (TSU), the touch sensing unit (TSU) is at a distance that the user or object can recognize as a touch, so that the touch sensing unit (TSU) touches the touch sensing unit (TSU). means to recognize

When a direct touch or an indirect touch occurs, a change in capacitance occurs between the first sensing electrodes Tx and the second sensing electrodes Rx included in the sensing electrode TE, for example. A sensing signal applied to the first sensing electrodes Tx according to a change in capacitance may be delayed and provided to the second sensing electrodes Rx. The touch sensing unit TSU may sense touch coordinates from a delay value of a detection signal.

Referring to FIG. 2 , in the foldable display device 10 according to an exemplary embodiment, the sensing electrode TE of the touch sensing unit TSU is provided on the display panel DP. When the display panel DP is an organic light emitting display panel, the sensing electrode TE may be directly provided on an encapsulation layer (not shown) of the display panel DP. Although not shown, a separate foldable substrate (not shown) may be provided between the sensing electrode TE and the display panel DP. In this case, an adhesive layer (not shown) for bonding the foldable substrate and the display panel DP may be provided.

The sensing electrode TE includes first sensing electrodes Tx and second sensing electrodes Rx. Each of the first sensing electrodes Tx and the second sensing electrodes Rx is electrically insulated from each other. Each of the first sensing electrodes Tx and the second sensing electrodes Rx has an approximate rhombus, square, rectangle, circle, or irregular shape (for example, branches are entangled like a dendrite structure). shape) can have various shapes. Each of the first sensing electrodes Tx and the second sensing electrodes Rx may have a mesh shape. Each of the first sensing electrodes TX and the second sensing electrodes Rx may have a shape in which a plurality of openings OP are defined.

The first sensing electrodes Tx and the second sensing electrodes Rx may be provided on the same layer. Each of the first sensing electrodes Tx and the second sensing electrodes Rx may be provided on the display panel DP.

The first sensing electrodes Tx may be spaced apart from each other in the third and fourth directions DR3 and DR4 . The second sensing electrodes Rx may be spaced apart from each other in the third and fourth directions DR3 and DR4 . The first sensing electrodes TX spaced apart in the third direction DR3 may be connected by a connection unit CN. The first sensing electrodes TX may be connected by the connection part CN to provide an electrode part extending in the third direction DR3 . The electrode part may include a plurality of first sensing electrodes TX and a connection part CN connecting the first sensing electrodes TX to each other. The second sensing electrodes Rx spaced apart in the fourth direction DR4 may be connected by a bridge BD. The bridge BD may be provided on the connection part CN connecting the first sensing electrodes Tx. Although not shown, an insulating layer may be provided between the connection portion CN and the bridge BD.

The connection lines TL1 and TL2 are electrically connected to each of the sensing electrodes TE. The connection wires TL1 and TL2 include first connection wires TL1 and second connection wires TL2 . The first connection lines TL1 may be connected to the first sensing electrodes Tx and the first fan-out lines PO1. The second connection lines TL2 may be connected to the second sensing electrodes Rx and the second fan-out lines PO2 .

The fan-out wires PO1 and PO2 are connected to the connection wires TL1 and TL2 and the pad parts PD1 and PD2, respectively. The fanout wires PO1 and PO2 include first fanout wires PO1 and second fanout wires PO2 . The first fan-out wires PO1 are connected to the first connection wires TL1 and the first pad parts PD1. The second fan-out wires PO2 are connected to the second connection wires TL2 and the second pad parts PD2.

The pad parts PD1 and PD2 are electrically connected to the sensing electrodes TE. The pad parts PD1 and PD2 include first pad parts PD1 and second pad parts PD2. The first pad parts PD1 are connected to the first fan-out wires PO1. The first pad parts PD1 may be electrically connected to the first sensing electrodes Tx. The second pad parts PD2 are connected to the second fan-out lines PO2. The second pad parts PD2 may be electrically connected to the second sensing electrodes Rx.

3A to 3E are schematic cross-sectional views corresponding to lines II' of FIG. 2 .

Referring to FIG. 3A , in the foldable display 10 according to an exemplary embodiment, the sensing electrode TE includes a metal layer ML and a lower graphene layer GR1. The lower graphene layer GR1 is provided between the metal layer ML and the display panel (DP in FIG. 2 ). More specifically, one surface of the lower graphene layer GR1 may contact the display panel (DP of FIG. 2 ), and the other surface of the lower graphene layer GR1 may contact the lower surface SD-1 of the metal layer ML. .

The metal layer ML may include at least one of metals. The metal is not particularly limited as long as it is commonly used, but may include, for example, at least one of Al, Cu, Mo, Ti, Ag, Mg, Pt, Pd, Au, Ni, Nd, Ir, and Cr. . Although not shown, each of the sensing electrodes TE according to an embodiment of the present invention may include a plurality of metal layers ML.

Referring to FIG. 3B , the sensing electrode TE may further include an upper graphene layer GR2 in addition to the metal layer ML and the lower graphene layer GR1. One surface of the lower graphene layer GR1 may contact the lower surface SD-1 of the metal layer ML. The other surface of the lower graphene layer GR1 may contact the display panel (DP of FIG. 2 ). The upper graphene layer GR2 may be provided on the metal layer ML. Specifically, the upper graphene layer GR2 may contact the upper surface SD- 2 of the metal layer ML. The upper graphene layer GR2 may be spaced apart from the lower graphene layer GR1 with the metal layer ML interposed therebetween. Side surfaces SD-3 and SD-4 of the metal layer ML may be exposed without being covered by the graphene layer.

Referring to FIGS. 3B and 3C , each of the lower graphene layer GR1 and the upper graphene layer GR2 may be provided as a plurality of layers. Specifically, the lower graphene layer GR1 may include a first lower graphene layer GR1-1, a second lower graphene layer GR1-2, and a third lower graphene layer GR1-3. The upper graphene layer GR2 may include a first upper graphene layer GR2-1, a second upper graphene layer GR2-2, and a third upper graphene layer GR2-3. The first lower graphene layer GR1-1, the second lower graphene layer GR1-2, and the third lower graphene layer GR1-3 are sequentially formed under the metal layer ML in the thickness direction of the sensing electrode TE. can be stacked with The first upper graphene layer GR2-1, the second upper graphene layer GR2-2, and the third upper graphene layer GR2-3 are sequentially formed on the metal layer ML in the thickness direction of the sensing electrode TE. can be stacked with Side surfaces SD-3 and SD-4 of the metal layer ML may be exposed without being covered by the graphene layer.

Referring to FIG. 3D , the sensing electrode TE may include a metal layer ML, a lower graphene layer GR1 and an upper graphene layer GR2. The upper graphene layer GR2 may be provided to cover the upper surface SD-2 and the side surfaces SD-3 and SD-4 of the metal layer ML. Specifically, the upper graphene layer GR2 may include an upper graphene portion GR2-C covering the upper surface SD-2 of the metal layer ML. The upper graphene layer GR2 may include side graphene portions GR2-P and GR2-P' covering the side surfaces SD-3 and SD-4 of the metal layer ML. A side surface of the metal layer ML may include a first side surface SD-3 and a second side surface SD-4 spaced apart from the first side surface SD-3. The side graphene parts GR2-P and GR2-P' include a first sub-graphene part GR2-P covering the first side surface SD-3 and a second sub-graphene part covering the second side surface SD-3. A graphene portion GR2-P' may be included. By means of the lower graphene layer GR1, the upper graphene portion GR2-C and the side graphene portions GR2-P and GR2-P' of the upper graphene layer GR2, the metal layer ML forms the lower surface SD-1. , The upper surface (SD-2) and the side surfaces (SD-3, SD-4) may be entirely covered.

Referring to FIGS. 3D and 3E , each of the lower graphene layer GR1 and the upper graphene layer GR2 may be provided as a plurality of layers. The lower graphene layer GR1 may include a first lower graphene layer GR1-1, a second lower graphene layer GR1-2, and a third lower graphene layer GR1-3. The upper graphene layer GR2 may include a first upper graphene layer GR2-1, a second upper graphene layer GR2-2, and a third upper graphene layer GR2-3. More specifically, the first upper graphene layer GR2-1 of the upper graphene layer GR2 includes the first upper graphene portion GR2-C1 contacting the upper surface SD-2 of the metal layer ML and the metal layer ML ) may include first side graphene parts GR2-P1 and GR2-P1' contacting the side surfaces SD-3 and SD-4. The first side graphene parts GR2-P1 and GR2-P1' include a first sub-graphene part GR2-P1 contacting the third side surface SD-3 and a first sub-graphene part GR2-P1 contacting the fourth side surface SD-4. It may include 2 sub graphene parts GR2-P1'. The second upper graphene layer GR2-2 of the upper graphene layer GR2 includes the second upper graphene portion GR2-C2 and the first side graphene portion GR2-C2 contacting the first upper graphene portion GR2-C1. It may include second side graphene parts GR2-P2 and GR2-P2' contacting the P1 and GR2-P1'. The second side graphene parts GR2-P2 and GR2-P2' include a third sub-graphene part GR2-P2 contacting the first sub-graphene part GR2-P1 and a second sub-graphene part GR2-P1'. ) may include a fourth sub-graphene portion (GR2-P2') contacting. The third upper graphene layer GR2-3 of the upper graphene layer GR2 includes the third upper graphene portion GR2-C3 and the second side graphene portion GR2-C3 contacting the second upper graphene portion GR2-C2. A third side graphene portion (GR2-P3, GR2-P3') contacting the P2 and GR2-P2' may be included. The third side graphene parts GR2-P3 and GR2-P3' include a fifth sub-graphene part GR2-P3 and a fourth sub-graphene part GR2-P2' contacting the third sub-graphene part GR2-P2. ) may include a sixth sub-graphene portion GR2-P3' in contact with.

3C and 3E show that the lower graphene layer GR1 and the upper graphene layer GR2 are provided as three layers, respectively, but are not limited thereto, and the lower graphene layer in the foldable display device according to an exemplary embodiment of the present invention is not limited thereto. (GR1) and the upper graphene layer (GR2) may be provided as a plurality of layers. Specifically, the lower graphene layer GR1 and the upper graphene layer GR2 may be provided as two layers or four or more layers.

4A to 4E are schematic cross-sectional views corresponding to line II-II' of FIG. 2 .

Referring to FIGS. 2 and 4A to 4E , the sensing electrode TE may have a mesh shape in which a plurality of openings OP are defined. More specifically, a plurality of openings OP are defined in the metal layer ML included in the sensing electrode TE, and in cross-section, the metal layer ML has a constant metal pattern ML-P defined by the openings OP. can be formed. The metal pattern ML-P may have a mesh shape. As the metal pattern ML-P is defined by the opening OP on a cross-section, an increase in resistance due to bending of the touch sensing unit TSU in the first mode of the foldable display 10 may be reduced.

Referring to FIG. 4A , metal patterns ML-P defining a plurality of openings OP may be provided on the metal layer ML of the sensing electrode TE. The metal pattern ML-P may have a mesh shape. The plurality of openings OP may be defined by the exposed surfaces SD-OP of the metal patterns ML-P. Metal patterns ML-P may be provided on the lower graphene layer GR1. One surface of the lower graphene layer GR1 may contact the display panel (DP of FIG. 2 ), and the other surface of the lower graphene layer GR1 may contact the lower surface SD- 1 ′ of the metal pattern ML. A portion of the lower graphene layer GR1 may be exposed by the plurality of openings OP defining the metal patterns ML-P.

Referring to FIGS. 4A and 4B , lower graphene patterns GR1 -P may be provided in the lower graphene layer GR1 to correspond to each of the metal patterns ML-P. The lower graphene pattern GR1 -P may have a mesh shape. One surface of the lower graphene pattern GR1 -P may contact the display panel (DP of FIG. 2 ), and the other surface may contact the lower surface SD-1' of the metal pattern ML. The plurality of openings OP may be defined by the exposed surface SD-OP of the metal patterns ML-P and the exposed surface SD-GR1 of the lower graphene pattern GR1-P.

Referring to FIG. 4C , the sensing electrode TE may further include an upper graphene layer GR2 provided on the metal patterns ML-P in cross section. An upper graphene pattern GR2 -P may be formed in the upper graphene layer GR2 to correspond to each of the metal patterns ML-P. The lower surface SD-1' of the metal patterns ML-P contacts the lower graphene pattern GR1-P, and the upper surface SD-2' of the metal patterns ML-P contacts the upper graphene pattern GR1-P. It may contact the pattern GR2-P. The plurality of openings OP may include the exposed surface SD-OP of the metal patterns ML-P, the exposed surface SD-GR1 of the lower graphene pattern GR1-P, and the upper graphene pattern GR2-P. ) can be defined by the exposed surface (SD-GR2).

Referring to FIGS. 4A and 4D , the sensing electrode TE may further include an upper graphene layer GR2 covering the metal patterns ML-P provided with the plurality of openings OP in cross section. Specifically, the upper graphene layer GR2 may include a top graphene portion GR2-C' covering the top surface SD-2' of the metal patterns ML-P. The upper graphene layer GR2 may include an exposed graphene portion GR2-OP covering the exposed surfaces SD-OP of the metal patterns ML-P exposed by the plurality of openings OP. have. The graphene portion GR2 -OP on the exposed surface of the upper graphene layer GR2 may cover a portion of the lower graphene layer GR1 exposed by the plurality of openings OP. Meanwhile, although not shown, the upper graphene layer GR2 may further include a side graphene portion (GR-2P in FIG. 3D) covering the side surfaces of the metal patterns ML-P.

Referring to FIGS. 4B and 4E , lower graphene patterns GR1 -P may be provided in the lower graphene layer GR1 to correspond to each of the metal patterns ML-P. The lower graphene pattern GR1 -P may have a mesh shape. One surface of the lower graphene pattern GR1 -P may contact the display panel (DP of FIG. 2 ), and the other surface may contact the lower surface SD-1' of the metal patterns ML-P. The upper graphene layer GR2 may be provided to cover the upper surface SD-2 ′ and the exposed surface SD-OP of the metal patterns ML-P provided with the plurality of openings OP. The upper graphene layer GR2 may include a top graphene portion GR2-C' covering the top surface SD-2' of the metal patterns ML-P. The upper graphene layer GR2 may include an exposed graphene portion GR2 -OP covering the exposed surface SD-OP of the metal patterns ML-P. As the lower graphene layer GR1 forms a pattern, the upper graphene layer GR2 forms a bottom contacting the exposed surface SD-GR1 of the lower graphene pattern GR1-P and the display panel (DP in FIG. 2). A graphene portion GR2-F may be further included. Meanwhile, although not shown, the upper graphene layer GR2 may further include a side graphene portion (GR-2P in FIG. 3D) covering the side surfaces of the metal patterns ML-P.

Referring to FIGS. 3A to 3E and 4A to 4E , reliability of the sensing electrode TE may be secured through the lower graphene layer GR1 and the upper graphene layer GR2 included in the sensing electrode TE. .

Sensing electrodes included in a conventional touch sensing unit include metal having high rigidity, so it is difficult to secure flexibility according to bending. Accordingly, when bending is repeated in the foldable display, cracks or disconnections occur in the sensing electrode, resulting in a problem in which the reliability of the touch sensing unit of the foldable display is deteriorated.

As mentioned above, the sensing electrodes included in the touch sensing unit according to an embodiment of the present invention include at least one graphene layer in contact with the metal layer, thereby improving the reliability problem of the touch sensing unit due to bending. have. More specifically, even if cracks or disconnection occur in the metal layer due to repetitive bending of the foldable display device, since the graphene layer in contact with the metal layer bypasses and transmits the detection signal, even if cracks or disconnection occur in the metal layer Reliability of the touch sensing unit may not deteriorate.

As shown in FIGS. 3C and 3E , when the lower graphene layer GR1 and the upper graphene layer GR2 are provided as a plurality of layers, the path for bypassing and transmitting the sensing signal increases, thereby effectively securing the reliability of the touch sensing unit. .

Although the sensing electrodes included in the touch sensing unit according to an embodiment of the present invention only include a graphene layer as a bypass layer as an example, silver capable of bypassing and transmitting a sensing signal even if a crack or disconnection occurs in the metal layer It may have a similar effect to when a graphene layer is provided, including a bypass layer including at least one of nanowires and PEDOT:PSS (Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)).

Hereinafter, a method of manufacturing a foldable display device according to an exemplary embodiment of the present invention will be described.

Referring to FIGS. 2, 3A to 3E, and 4A to 4E , a method of manufacturing a foldable display device 10 according to an embodiment of the present invention includes providing a display panel DP, a display panel ( The step of providing the lower graphene layer GR1 on the DP and the step of providing the metal layer ML on the lower graphene layer GR1 are included. The manufacturing method of the foldable display device 10 according to an exemplary embodiment of the present invention may further include providing an upper graphene layer GR2 after providing the metal layer ML.

The step of providing the lower graphene layer GR1 may be performed through a chemical vapor deposition (CVD) method or a printing method. For the lower graphene layer GR1, graphene is applied to the display panel through a chemical vapor deposition method or a printing process, and then the lower graphene layer GR1 is applied to a specific location where the sensing electrode TE is formed through an etching process. can provide

Meanwhile, after graphene is applied to the display panel through a chemical vapor deposition method or a printing process, and a metal material is applied on the graphene, the lower graphene layer GR1 and the metal layer ML are collectively formed through an etching process for the metal. can be provided ad hoc. In this case, the etching process may be performed by dry etching. As the graphene and metal are etched simultaneously to provide the lower graphene layer GR1 and the metal layer ML at once, time consumed in the process can be reduced and the manufacturing process can be simplified.

The step of providing the upper graphene layer GR2 may be performed through a chemical vapor deposition method or a printing method. The upper graphene layer GR2 may be provided to contact the upper surface SD- 2 of the metal layer ML and to be spaced apart from the lower graphene layer GR1. Alternatively, the upper graphene layer GR2 may be provided to cover the upper surface SD-2 and the side surfaces SD-3 and SD-4 of the metal layer ML.

Sensing electrodes included in a conventional touch sensing unit include metal having high rigidity, so it is difficult to secure flexibility according to bending. Accordingly, when bending is repeated in the foldable display, cracks or disconnections occur in the sensing electrode, resulting in a problem in which the reliability of the touch sensing unit of the foldable display is deteriorated.

A foldable display device manufactured by the method of manufacturing a foldable display device according to an embodiment of the present invention includes a graphene layer contacting both upper and lower surfaces or end surfaces of a metal layer for sensing electrodes included in a touch sensing unit. steps to provide Accordingly, it is possible to improve a problem in which the reliability of the touch sensing unit decreases due to bending. More specifically, even if cracks or disconnection occur in the metal layer due to repetitive bending of the foldable display device, since the graphene layer in contact with the metal layer bypasses and transmits the detection signal, even if cracks or disconnection occur in the metal layer Reliability of the touch sensing unit may not deteriorate.

Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art can implement the present invention in other specific forms without changing its technical spirit or essential features. You will understand that there is Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive.

10: display device DP: display panel
TSU: Touch Sensing Unit TE: Sensing Electrode
ML: metal layer GR1: lower graphene layer
GR2: upper graphene layer

Claims (13)

display panel; and
a touch sensing unit provided on the display panel;
The touch sensing unit
Includes a plurality of sensing electrodes for recognizing a touch;
Each of the sensing electrodes is
metal layer;
a lower graphene layer provided between the metal layer and the display panel and contacting a lower surface of the metal layer; and
A foldable display comprising an upper graphene layer spaced apart from the lower graphene layer and provided in contact with an upper surface of the metal layer. delete According to claim 1,
The lower graphene layer is
a first lower graphene layer;
a second lower graphene layer; and
Including a third lower graphene layer,
The upper graphene layer is
a first upper graphene layer;
a second upper graphene layer; and
A foldable display device including a third upper graphene layer. According to claim 1,
The foldable display device further includes an upper graphene layer provided to cover the top and side surfaces of the metal layer. According to claim 4,
The upper graphene layer is
a top graphene portion covering the top surface of the metal layer; and
A foldable display device including a side graphene portion connected to the top graphene portion and covering the side surface of the metal layer. According to claim 5,
Said side is
Including a first side and a second side spaced apart from the first side,
The side graphene part
a first sub-graphene portion covering the first side surface; and
A foldable display device comprising a second sub-graphene portion covering the second side surface. According to claim 4,
The lower graphene layer is
a first lower graphene layer;
a second lower graphene layer; and
Including a third lower graphene layer,
The upper graphene layer is
a first upper graphene layer;
a second upper graphene layer; and
A foldable display device including a third upper graphene layer. According to claim 7,
The first upper graphene layer is
a first upper graphene portion contacting the upper surface of the metal layer; and
A first side graphene portion contacting the side surface of the metal layer;
The second upper graphene layer is
a second top graphene portion contacting the first top graphene portion; and
A second side graphene portion contacting the first side graphene portion;
The third upper graphene layer is
a third top graphene portion contacting the second top graphene portion; and
A foldable display including a third side graphene portion contacting the second side graphene portion. According to claim 1,
the metal layer
A foldable display in which a plurality of openings are defined and has a mesh shape. According to claim 9,
The lower graphene layer is
A foldable display device having a mesh shape, wherein each of a plurality of graphene openings corresponding to each of the openings of the metal layer is defined. According to claim 9,
Further comprising an upper graphene layer covering the metal layer,
The upper graphene layer is
a top graphene portion covering an upper surface of the metal layer; and
A foldable display device including a plurality of exposed surface graphene parts covering the exposed surface exposed by the openings. According to claim 1,
the metal layer
A foldable display device including at least one selected from the group consisting of Al, Cu, Mo, Ti, Ag, Mg, Pt, Pd, Au, Ni, Nd, Ir, and Cr. According to claim 1,
The foldable display device
A foldable display device operating in a first mode in which at least a portion of the display panel and the touch sensing unit are bent or in a second mode in which the bending is extended.

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