KR20210062900A - Flexible display device - Google Patents

Abstract

The present specification discloses a flexible display device. The flexible display device includes: a display area in which sub-pixels are disposed; a non-display area around the display area; and a support structure including a connection interface area included in the non-display area, wherein the connection interface area includes a first display pad and a second display pad further away from the display area than the first display pad, and disposed between the first display pad and the second display pad. The support structure is provided to prevent the display device from being bent between the first display pad and the second display pad.

Description

Flexible display device {FLEXIBLE DISPLAY DEVICE}

The present specification relates to a flexible display device, and more particularly, to a display device having improved durability of a connection interface portion.

As information technology develops, the market for display devices, which is a connection medium between users and information, is growing. Accordingly, the use of display devices such as organic light emitting display (OLED) and liquid crystal display (LCD) is increasing.

The display device includes a display panel including a plurality of sub-pixels and a driving unit for driving the display panel. The driver includes a scan driver that supplies a scan signal (or a gate signal) to the display panel, and a data driver that supplies a data signal to the display panel. In the display device as described above, when a scan signal and a data signal are supplied to sub-pixels arranged in a matrix form, the selected sub-pixel emits light to display an image.

A driver for driving one or more of the data lines and gate lines of the display device may be implemented as an integrated circuit (IC) mounted on a chip. In addition, for cost reduction and structural convenience of the driving IC for driving data lines and/or gate lines of the display device, a technique for directly attaching the driving IC to the substrate of the display panel is preferred.

On the other hand, some of the above-described display devices manufacture a display panel based on a flexible substrate instead of a rigid substrate. Since such a display device can impart flexibility, the display panel can be bent into a specific shape.

In addition, recent display devices. To accommodate the demand for a convenient and simple command input device, a touch input method in which a user directly contacts a screen to input information is adopted. For example, in an organic light emitting display device, touch elements are provided on an upper portion or a lower portion of an encapsulation film. That is, the touch driving electrodes constituting the touch driving signal transmission channel and the touch sensing electrodes constituting the touch recognition signal receiving channel are disposed on the upper surface and/or the lower surface of the encapsulation film covering the display elements.

An object of the present specification is to provide an input/output interface structure of a display device. In particular, the present specification intends to provide a method for reducing damage occurring around structures such as pads and pins connected to a driving circuit chip. The tasks of the present specification are not limited to the tasks mentioned above, and other tasks not mentioned will be clearly understood by those skilled in the art from the following description.

According to an embodiment of the present specification, a flexible display device is provided. The flexible display device may include a display area in which sub-pixels are disposed; a non-display area surrounding the display area; a connection interface area included in the non-display area, wherein the connection interface area includes a first display pad; a second display pad further away from the display area than the first display pad; and a support structure interposed between the first display pad and the second display pad. The support structure is provided to prevent the display device from being bent between the first display pad and the second display pad.

The flexible display device further includes a driving circuit chip connected to the first display pad and the second display pad, and the driving circuit chip supplies a signal for driving the sub-pixels. The driving circuit chip may include a circuit unit and a connection unit.

The flexible display device may further include the connection part and an adhesive member for attaching the first display pad and the second display pad to each other. The adhesive member may include conductive particles; and an adhesive layer in which the conductive particles are dispersed.

The support structure may have a shape in which the conductive particles are dispersed, and the support structure may have a stripe shape, an island shape, or a zigzag shape.

The support structure may include a first layer made of the same material as a planarization layer covering the thin film transistor (TFT) of the display area. The support structure may be made of the same material as the bank layer of the display area and further include a second layer on the first layer.

The first display pad or the second display pad may include a first electrode layer formed of the same material as a gate electrode of a thin film transistor (TFT) in the display area; a second electrode layer disposed on the first electrode layer and formed of the same material as a source or drain electrode of a thin film transistor (TFT) in the display area; and at least one of a third electrode layer on the second electrode layer. The third electrode layer may be made of the same material as the touch electrode. The touch electrode may be formed on an encapsulation portion covering the sub-pixel. An insulating layer between the first front layer and the second electrode layer may be further provided.

According to another embodiment of the present specification, a display device is provided. The display device includes: a flexible substrate on which sub-pixels are disposed; a driving circuit chip having a circuit for controlling the sub-pixels; a first pad column and a second pad column provided on the flexible substrate to be connected to the driving circuit chip; and a support structure positioned between the first pad row and the second pad row and provided to prevent the flexible substrate under the driving circuit chip from being bent.

The display device may include conductive particles; and an adhesive member including an adhesive layer in which the conductive particles are dispersed.

Details of other embodiments are included in the detailed description and drawings.

Embodiments of the present specification may provide a display device having an input/output interface structure that is robust to external forces. In particular, embodiments of the present specification may prevent damage to a display device using a flexible substrate. Accordingly, embodiments of the present specification may provide a display device with improved mechanical reliability. Effects according to the embodiments of the present specification are not limited by the contents exemplified above, and more various effects are included in the present specification.

1 is an exploded perspective view illustrating a display device having a built-in touch sensor.
FIG. 2 is a plan view illustrating the display device shown in FIG. 1 .
3 is a cross-sectional view illustrating a portion cut along I - I' in FIG. 2 .
FIG. 4 is a plan view showing an enlarged portion A of FIG. 2 .
FIG. 5 is a view showing problems that may appear in a part III-III' in FIG. 4 .
6A and 6B are cross-sectional views illustrating a connection interface area according to an embodiment of the present specification.
7A to 7C are perspective views illustrating various embodiments of a support structure according to an embodiment of the present specification.
8 is a plan view illustrating various embodiments of the support structure.

Advantages and features of the present specification, and a method of achieving them will become apparent with reference to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms different from each other, and only these embodiments make the disclosure of the present invention complete, and common knowledge in the technical field to which the present invention pertains. It is provided to completely inform the scope of the invention to the possessor, and the invention is only defined by the scope of the claims.

The shapes, sizes, proportions, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of the present specification are illustrative and the present specification is not limited to the illustrated matters. The same reference numerals refer to the same elements throughout the specification. In addition, in describing the present invention, when it is determined that a detailed description of related known technologies may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. When 'including', 'having', 'consisting', etc. mentioned in this specification are used, other parts may be added unless 'only' is used. In the case of expressing the constituent elements in the singular, it includes the case of including the plural unless specifically stated otherwise. In interpreting the constituent elements, it is interpreted as including an error range even if there is no explicit description.

In the case of a description of the positional relationship, for example, if the positional relationship of two parts is described as'upper','upper of','lower of','next to','right' Or, unless'direct' is used, one or more other parts may be located between the two parts. When an element or layer is referred to as “on” another element or layer, it includes all cases in which another layer or another element is interposed directly on or in the middle of another element. When a component is described as being "connected", "coupled" or "connected" to another component, the component may be directly connected or connected to that other component, but other components between each component It should be understood that "interposed" or that each component may be "connected", "coupled" or "connected" through other components.

Although the first, second, etc. are used to describe various components, these components are not limited by these terms. These terms are only used to distinguish one component from another component. Accordingly, the first component mentioned below may be a second component within the technical idea of the present invention.

The size and thickness of each component shown in the drawings are illustrated for convenience of description, and the present invention is not necessarily limited to the size and thickness of the illustrated component. Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is an exploded perspective view illustrating a display device having a built-in touch sensor. FIG. 2 is a plan view illustrating the display device shown in FIG. 1 . 3 is a cross-sectional view illustrating a portion cut along I - I' in FIG. 2 .

The display device shown in FIG. 1 detects the presence or absence of a touch and the location of the touch by detecting the amount of change in mutual capacitance (Cm) caused by the user's touch through the touch electrodes 152e and 154e shown in FIG. 2 . . In addition, the display device having a touch sensor shown in FIG. 1 displays an image through a unit pixel. The unit pixel is composed of red (R), green (G), and blue (B) sub-pixels (PXL), or red (R), green (G), blue (B) and white (W) sub-pixels (PXL) is composed of The display device described below is assumed to be an organic light emitting diode display having flexible characteristics, but the inventive concept is not limited thereto.

For touch sensing, the organic light emitting display device includes a plurality of sub-pixels PXL arranged in a matrix form on a substrate 111 , and an encapsulation unit 140 disposed on the plurality of sub-pixels PXL; , and a mutual capacitance (Cm) disposed on the encapsulation unit 140 .

Each of the sub-pixels PXL includes a pixel circuit and a light emitting device 120 connected to the pixel circuit. The pixel circuit may include a switching transistor T1 , a driving transistor T2 , and a storage capacitor Cst.

The switching transistor T1 is turned on when a scan pulse is supplied to the scan line SL and supplies the data signal supplied to the data line DL to the storage capacitor Cst and the gate electrode of the driving transistor T2 . The driving transistor T2 controls the current supplied from the high voltage (VDD) supply line to the light emitting device 120 in response to the data signal supplied to the gate electrode of the driving transistor T2 to control the amount of light emitted by the light emitting device 120 . will be regulated And, even when the switching transistor T1 is turned off, the driving transistor T2 by the voltage charged in the storage capacitor Cst supplies a constant current until the data signal of the next frame is supplied, so that the light emitting device 120 is turned off. keep luminous.

As shown in FIG. 3 , the driving thin film transistors T2 and 130 include a gate electrode 132 , a semiconductor layer 134 overlapping the gate electrode 132 with a gate insulating layer 112 interposed therebetween, and an interlayer insulating layer. It may include source and drain electrodes 136 and 138 that are formed on the 114 and contact the semiconductor layer 134 . The semiconductor layer 134 may be formed on the gate insulating layer 112 using at least one of an amorphous semiconductor material, a polycrystalline semiconductor material, and an oxide semiconductor material. The gate electrode 132 may be formed of various conductive materials, for example, magnesium (Mg), aluminum (Al), nickel (Ni), chromium (Cr), molybdenum (Mo), tungsten (W), gold (Au), or an alloy thereof. and the like. The source and drain electrodes 136 and 138 may be formed of titanium (Ti), aluminum (Al), or an alloy thereof.

The gate insulating layer 112 may be formed of an insulating material such as silicon oxide (SiOx) or silicon nitride (SiNx), and may also be formed of an insulating organic material. A planarization layer 118 may be disposed on the thin film transistor. The planarization layer 118 has a contact hole exposing the drain electrode 138 of the thin film transistor. The planarization layer 118 functions to uniform the roughness of the substrate surface in order to apply the light emitting stack 124 constituting the organic light emitting device in a smooth planar state. The planarization layer 118 may be configured in various forms, and may be formed of an organic insulating film such as BCB (Benzocyclobutene) or acryl, or an inorganic insulating film such as a silicon nitride film (SiNx) or a silicon oxide film (SiOx), Various modifications are possible, such as being formed in a single layer or may be composed of double or multiple layers.

The light emitting device 120 includes an anode electrode 122 , at least one light emitting stack 124 formed on the anode electrode 122 , and a cathode electrode 126 formed on the light emitting stack 124 . The anode electrode 122 is electrically connected to the drain electrode 138 of the driving thin film transistors 130 and T2 exposed through the pixel contact hole 148 penetrating the passivation layer 116 .

A light emitting stack 124 is formed on the anode electrode 122 in a light emitting area separated by a bank 128 . The at least one light emitting stack 124 is formed by stacking a hole-related layer, an organic light-emitting layer, and an electron-related layer on the anode electrode 122 in the order or in the reverse order. In addition, the light emitting stack 124 may include first and second light emitting stacks facing each other with a charge generation layer (CGL) interposed therebetween. In this case, one organic light emitting layer of the first and second light emitting stacks generates blue light, and the other organic light emitting layer of the first and second light emitting stacks generates yellow-green light, thereby forming the first and second light emitting stacks. White light is produced through Since white light generated by the light emitting stack 124 is incident on a color filter (not shown) positioned above or below the light emitting stack 124 , a color image may be realized. In addition, a color image may be implemented by generating color light corresponding to each sub-pixel in each light emitting stack 124 without a separate color filter. That is, the light-emitting stack 124 of the red (R) sub-pixel generates red light, the light-emitting stack 124 of the green (G) sub-pixel generates green light, and the light-emitting stack 124 of the blue (B) sub-pixel generates blue light. You may.

The cathode electrode 126 is formed to face the anode electrode 122 with the light emitting stack 124 interposed therebetween and is connected to a low voltage (VSS) supply line.

The bank 128 is formed in the remaining area except for the light emitting area. The bank 128 has a bank hole exposing the anode electrode 122 corresponding to the light emitting region. The bank 128 may be made of an inorganic insulating material such as a silicon nitride film (SiNx) or a silicon oxide film (SiOx), or an organic insulating material such as BCB, an acrylic resin, or an imide resin. A spacer may be formed on the bank 128 . The spacer may be formed of an organic layer such as an acrylic resin, an epoxy resin, a phenolic resin, a polyamide resin, or a polyimide resin. If necessary, the spacer may be omitted.

The encapsulation unit 140 blocks the penetration of external moisture or oxygen into the light emitting device 120 vulnerable to external moisture or oxygen. To this end, the encapsulation unit 140 includes a plurality of inorganic encapsulation layers 142 and 146 and an organic encapsulation layer 144 disposed between the plurality of inorganic encapsulation layers 142 and 146 , and the inorganic encapsulation layer (146) is placed on the top floor. In this case, the encapsulation unit 140 includes at least two inorganic encapsulation layers 142 and 146 and at least one organic encapsulation layer 144 . In the present invention, the structure of the encapsulation unit 140 in which the organic encapsulation layer 144 is disposed between the first and second inorganic encapsulation layers 142 and 146 will be described as an example.

The first inorganic encapsulation layer 142 is formed on the substrate 111 on which the cathode electrode 126 is formed so as to be closest to the light emitting device 120 . The first inorganic encapsulation layer 142 is formed of an inorganic insulating material capable of low-temperature deposition, such as silicon nitride (SiNx), silicon oxide (SiOx), silicon oxynitride (SiON), or aluminum oxide (Al2O3). Accordingly, since the first inorganic encapsulation layer 142 is deposited in a low temperature atmosphere, it is possible to prevent damage to the light emitting stack 124 that is vulnerable to a high temperature atmosphere during the deposition process of the first inorganic encapsulation layer 142 .

The organic encapsulation layer 144 serves as a buffer to relieve stress between the respective layers due to bending of the organic light emitting diode display, and enhances planarization performance. Silicon oxy carbon (SiOCz) may be used, or acryl or epoxy-based resin may be used, but is not limited thereto. For example, when the organic encapsulation layer 144 is formed of SiOCz, the organic encapsulation layer 144 may be formed by a CVD process. SiOCz is an inorganic material, but can be classified as an organic material under certain conditions. Specifically, the flowability of SiOCz varies according to the atomic ratio of silicon to carbon (C/Si). For example, when the flowability of SiOCz deteriorates, since it has properties close to inorganic materials, the performance of compensating for foreign substances is lowered. The C/Si ratio of SiOCz can be controlled by adjusting the ratio of oxygen (O2) and hexamethyldisiloxane (HMDSO) during the CVD process. In particular, when the organic encapsulation layer 144 is formed of SiOCz, the thickness of the encapsulation unit 140 may be realized to be very thin, and the thickness of the display device may be reduced.

For example, when the organic encapsulation layer 144 is formed of an acrylic or epoxy-based resin, the organic encapsulation layer 144 may be formed by a slit coating or screen printing process. In this case, as the epoxy-based resin, high-viscosity bisphenol-A-epoxy or low-viscosity bisphenol-F-epoxy may be used. The organic encapsulation layer 144 may further include an additive. For example, a wetting agent for reducing the surface tension of the resin to improve the uniformity of the resin, a leveling agent for improving the surface flatness of the resin, an antifoaming agent for removing air bubbles contained in the resin ( Defoaming agent) may be further added as an additive. The organic encapsulation layer 144 may further include an initiator. For example, it is possible to use an antimony-based initiator or anhydride-based initiator that hardens a liquid resin by initiating a chain reaction by heat.

The organic encapsulation layer 144 functions to cover foreign substances or particles that may be generated during the process. For example, defects due to cracks generated by foreign substances or particles may exist in the first inorganic encapsulation layer 142 . However, these curves and foreign substances may be covered by the organic encapsulation layer 144 , and the upper surface of the organic encapsulation layer 144 is planarized. That is, the organic encapsulation layer 144 compensates for the foreign material and planarizes the display area. As a result, the organic encapsulation layer 144 may be referred to as a compensation layer.

The second inorganic encapsulation layer 146 is formed to cover the upper surface and side surfaces of the organic encapsulation layer 144 and the upper surface of the first inorganic encapsulation layer 142 exposed by the organic encapsulation layer 144 . Accordingly, the second inorganic encapsulation layer 146 minimizes or blocks the penetration of external moisture or oxygen into the first inorganic encapsulation layer 142 and the organic encapsulation layer 144 . The second inorganic encapsulation layer 146 is formed of an inorganic insulating material such as silicon nitride (SiNx), silicon oxide (SiOx), silicon oxynitride (SiON), or aluminum oxide (Al2O3). The first and second inorganic encapsulation layers 142 and 146 may be made of the same material, and each may be a plurality of layers.

The total thickness of the encapsulation unit 140 is preferably 10 μm to 30 μm to sufficiently prevent moisture penetration from the outside and prevent the flow of internal particles and the influence of internal particles.

Meanwhile, the encapsulation unit 140 is provided to cover at least the active area, and thus the side portion is positioned in the non-display area. And, what is exposed to the side of the non-display area is limited to the inorganic encapsulation layer to effectively prevent the penetration of external air. That is, the organic encapsulation layer 144 is located in the inner region closer to the active area AA than the upper and lower inorganic encapsulation layers 142 and 146 , and the upper second inorganic encapsulation layer 146 is the organic encapsulation layer 144 . ) to cover the upper and side portions together, and to extend relative to the organic encapsulation layer 144 to meet at the side with the first inorganic encapsulation layer 142 , which is relatively more protruding than the organic encapsulation layer 144 .

On the encapsulation unit 140 , the touch sensing line 154 and the touch driving line 152 are disposed to cross each other with the touch insulating layer 158 interposed therebetween. A mutual capacitance Cm is formed at the intersection of the touch sensing line 154 and the touch driving line 152 . Accordingly, the mutual capacitance Cm is charged with a touch driving pulse supplied to the touch driving line 152 , and discharged to the touch sensing line 154 , thereby serving as a touch sensor.

The touch driving line 152 includes a plurality of first touch electrodes 152e and first bridges 152b electrically connecting the plurality of first touch electrodes 152e. The plurality of first touch electrodes 152e are spaced apart from each other at regular intervals along the Y direction, which is the first direction, on the second inorganic encapsulation layer 146 . Each of the plurality of first touch electrodes 152e is electrically connected to an adjacent first touch electrode 152e through a first bridge 152b. The first bridge 152b is disposed on the second inorganic encapsulation layer 146 coplanar with the first touch electrode 152e and is electrically connected to the first touch electrode 152e without a separate contact hole.

The touch sensing line 154 includes a plurality of second touch electrodes 154e and second bridges 154b electrically connecting the plurality of second touch electrodes 154e. The plurality of second touch electrodes 154e are spaced apart from each other at regular intervals along the X direction, which is the second direction, on the second inorganic encapsulation layer 146 . Each of the plurality of second touch electrodes 154e is electrically connected to an adjacent second touch electrode 154e through a second bridge 154b. The second bridge 154b is formed on the touch insulating layer 158 and is exposed through the touch contact hole 150 penetrating the touch insulating layer 158 to be electrically connected to the second touch electrode 154e. Since the second bridge 154b is disposed to overlap the bank 128 like the first bridge 152b, it is possible to prevent a reduction in the aperture ratio by the first and second bridges 152b and 154b.

Each of the first and second touch electrodes 152e and 154e and the first and second bridges 152b and 154b is formed of a single layer using a conductive layer having strong corrosion resistance and acid resistance such as Al, Ti, Cu, Mo, and good conductivity. Or it is formed in a multi-layer structure. For example, each of the first and second touch electrodes 152e and 154e and the first and second bridges 152b and 154b is formed in a three-layered structure such as Ti/Al/Ti or Mo/Al/Mo. do.

Each of the first and second touch electrodes 152e and 154e and the first and second bridges 152b and 154b is formed in a mesh shape. Accordingly, the resistance and capacitance of the first and second touch electrodes 152e and 154e and the first and second bridges 152b and 154b themselves are reduced, so that the RC time constant is reduced, thereby improving touch sensitivity. In addition, since the line widths of the first and second touch electrodes 152e and 154e and the first and second bridges 152b and 154b in the mesh form are very thin, the first and second touch electrodes 152e and 154e in the form of a mesh are very thin. , it is possible to prevent the aperture ratio and transmittance from being lowered due to the first and second bridges 152b and 154b.

Each of the touch driving line 152 and the touch sensing line 154 of the present invention is connected to a touch driving unit (not shown) through a routing line 156 and a touch pad 170 disposed in a non-display (bezel) area. do.

Accordingly, the routing line 156 transmits the touch driving pulse generated by the touch driving unit to the touch driving line 152 through the touch pad 170 , and transmits the touch signal from the touch sensing line 154 to the touch pad 170 . ) is sent to The routing line 156 is disposed between each of the first and second touch electrodes 152e and 154e and the touch pad 170, and is connected to each of the first and second touch electrodes 152e and 154e without a separate contact hole. directly connected Since the routing line 156 is formed by the same mask process as the first bridge 152b using the same material as the first bridge 152b, it is protected by the touch insulating film 158 .

The routing line 156 connected to the first touch electrode 152e is extended to at least one of the upper and lower sides of the active area and is connected to the touch pad 170 as shown in FIG. 2 . The routing line 156 connected to the second touch electrode 154e extends to at least one of the left and right sides of the active area and is connected to the touch pad 170 . Meanwhile, the arrangement of the routing line 156 is not limited to the structure of FIG. 2 and may be variously changed according to design matters of the display device.

The display device illustrated in FIGS. 1 and 2 has a form in which the driving circuit chip 1500 can be directly attached to the substrate 111 . To this end, a connection interface region A as shown in FIG. 4 is provided on the substrate 111 .

FIG. 4 is an enlarged plan view of part A of FIG. 2 , and FIG. 5 is a view showing problems that may appear in part III-III' in FIG. 4 .

Part A of FIG. 4 is a connection interface area provided to mount the driving circuit chip 1500 . The display pad 180 is a kind of connection electrode and is provided for electrical connection with the driving circuit chip 1500 . Signals and/or information output from the driving circuit chip 1500 are transmitted to a pixel circuit or the like through the display pad 180 .

A cross-sectional structure of the III-III' portion may be as shown in FIG. 5 . The display pad 180 may include a first electrode layer 162 , a second electrode layer 164 , and a third electrode layer 168 sequentially stacked from the substrate 111 . A first insulating layer 163 may be disposed on the first electrode layer 162 . Although not shown in the drawings, the first electrode layer 162 and the second electrode layer 164 may be electrically connected to each other through a contact hole of the first insulating layer 163 . The second electrode layer 164 may be formed of the same metal as the source and drain electrodes 136 and 138 of the display area. The third electrode layer 168 may be made of the same material as the touch electrodes 152e and 154e.

The driving circuit chip 1500 may include a circuit unit 1510 and a connection unit 1520 . The connection unit 1520 transmits a signal generated by the circuit unit 1510 to the display pad 180 and may be referred to as a connection electrode, a pin, a bump, or the like. The connection part 1520 may protrude to be disposed on one surface of the circuit part 1510 . An adhesive member 1600 may be provided between the connection part 1520 and the display pad 180 . The adhesive member 1600 may be an anisotropic conductive film. The adhesive member 1600 may include an adhesive layer 1610 in which conductive particles 1620 such as conductive balls are dispersed. In the adhesive member 1600 , an electric current passes by the intervening conductive particles 1620 , and the adhesive layer 1610 made of a resin or the like is cured to maintain adhesive force. Accordingly, the connection part 1520 and the display pad 180 are electrically connected by the conductive particles 1620 .

The inventors have recognized a problem that occurs when the driving circuit chip 1500 is attached to the display pad 180 on a flexible substrate. One of them is a phenomenon in which the display panel is bent as shown in FIG. 5 , and this phenomenon was discovered while increasing the pressure for bonding the driving circuit chip 1500 . The adhesion pressure is increased when the surface resistance of the display pad 180 is high, but when the substrate 111 is a flexible material (eg, a material such as polyimide), the warpage is frequently observed. Since the connection part 1520 and the display pad 180 have a predetermined height, a space is created between the display panel and the circuit part 1510 in the portion without them, and when a strong pressure (for attaching the driving circuit chip) is applied, the The display panel warped in space. When such warpage occurs, the substrate 111 and/or the insulating layers 163 and 167 thereon may be damaged such as cracks.

Recognizing the above problem, the present inventors recognized the need for (1) reducing the adhesion pressure to reduce damage to the display pad 180 (eg, formation of an oxide film on the surface), or (2) an auxiliary structure that prevents bending of the substrate.

6A and 6B are cross-sectional views illustrating a connection interface area according to an embodiment of the present specification.

In the embodiment shown in Figs. 6A and 6B, most components are the same as in the embodiment of Figs. 4 and 5 . Accordingly, descriptions of overlapping elements will be omitted. However, the support structure 665 between the display pads 180 is a different element from the exemplary embodiment of FIGS. 4 and 5 . Hereinafter, these differences will be mainly described.

The support structure 665 is a structure devised by the inventors so that the problem as shown in FIG. 5 does not occur. The support structure 665 is particularly applied to a flexible display device, so that the display device bends (especially occurs in the connection interface region). ) can be prevented.

Accordingly, a flexible display device according to an exemplary embodiment of the present specification includes a display area in which sub-pixels are disposed; a non-display area surrounding the display area; and a connection interface area included in the non-display area. a first display pad 180 - 1 in the connection interface area; a second display pad 180 - 2 farther from the display area than the first display pad; and a support structure 665 between the first display pad and the second display pad. The support structure 665 is provided between the first display pad 180-1 and the second display pad 180-2 to prevent the display device (a substrate and functional layers thereon) from being bent. to be. A planar positional relationship between the first display pad 180 - 1 and the second display pad 180 - 2 is shown in FIGS. 7 and 8 .

The first display pad 180 - 1 and/or the second display pad 180 - 2 may be formed of a plurality of metal layers stacked vertically. For example, the first display pad 180 - 1 and/or the second display pad 180 - 2 may include at least one of a first electrode layer 162 , a second electrode layer 164 , and a third electrode layer 168 . may include. 6A and 6B show that both the first display pad 180 - 1 and the second display pad 180 - 2 are composed of three metal layers, but this is only an example and is not limited thereto. The first electrode layer 162 may be formed of the same material as the gate electrode of the thin film transistor TFT in the display area. Also, the second electrode layer 164 may be disposed on the first electrode layer 162 and formed of the same material as the source or drain electrode of the thin film transistor TFT in the display area. In addition, the third electrode layer 168 may be positioned on the second electrode layer 164 and made of the same material as the touch electrode. In this case, the touch electrode may be formed on the encapsulation part covering the sub-pixel. Insulating layers are disposed between the first electrode layer 162 , the second electrode layer 164 , and the third electrode layer 168 , and each electrode layer may be connected through a contact hole or the like. The insulating layer(s) may be made of the same material as the gate insulating layer 112 and/or the interlayer insulating layer 114 of the display area.

The flexible display device further includes a driving circuit chip 1500 connected to the first display pad 180 - 1 and the second display pad 180 - 2 . The driving circuit chip 1500 supplies a signal (eg, a data voltage, a control signal, etc.) for driving the sub-pixel. The driving circuit chip 1500 may include a circuit unit 1510 and a connection unit 1520 . The circuit unit 1510 includes various functional circuits responsible for driving the sub-pixels, and includes a circuit board and a storage container thereof. The connection part 1520 is a conductive electrode (pin, bump) that electrically connects the display pad 180 and the circuit part 1510 . The connection part 1520 may be provided in a protruding shape under the circuit part 1510 .

The flexible display device further includes the connection part 1520 and an adhesive member 1600 for attaching the first display pad 180 - 1 and the second display pad 180 - 2 to each other. That is, the connection part 1520 and the display pad 180 are bonded to each other by the adhesive member 1600 . For example, the adhesive member 1600 may be an anisotropic conductive film. The adhesive member 1600 includes conductive particles 1620 and an adhesive layer 1610 in which the conductive particles are dispersed. Accordingly, the connection part 1520 and the display pad 180 are electrically connected by the conductive particles 1620 .

The flexible display device according to the exemplary embodiment of the present specification may include a flexible substrate 111 on which sub-pixels are disposed. The flexible substrate may include glass, metal, or plastic, and may be formed of a flexible material. For example, the flexible substrate 111 may include polyethersulfone, polyacrylate, polyetherimide, polyethylene naphthalate, polyethylene terephthalate, polyphenylene sulfide, polyallylate, polyimide, polycarbonate, and cellulose. tri acetate, cellulose acetate propionate, and the like.

The support structure 665 between the first display pad 180 - 1 and the second display pad 180 - 2 prevents the flexible substrate 111 from being bent in the direction of the driving circuit chip 1500 . As shown in FIGS. 6A or 6B , the substrate and its upper layers can maintain a predetermined distance from the driving circuit chip 1500 by the support structure.

The support structure 665 may protrude upward from the substrate 111 . The support structure 665 includes a first layer 665 - 1 made of the same material as a planarization layer covering the thin film transistor (TFT) of the display area; and at least one of a second layer 665 - 2 made of the same material as the bank layer of the display area and disposed on the first layer. As illustrated in FIGS. 6A and 6B , the support structure 665 may be formed of only the first layer 665-1, or may be formed of the first layer 665-1 and the second layer 665-2. can

The support structure 665 may extend in the same direction as the first display pad column 180 - 1 or the second display pad column 180 - 2 as shown in FIG. 7A . In this case, the support structure 665 may have a shape divided into two or more as shown in FIG. 7B or 7C . When the conductive particles 1620 are aggregated, adjacent display pads may be short-circuited with each other. The support structure of the shape shown in FIGS. 7B or 7C can more evenly distribute the conductive particles 1620 than the shape of FIG. 7A , which is more effective in preventing the short circuit. effective.

In view of dispersion of the conductive particles, the support structure 665 may have various planar shapes. As illustrated in FIG. 8 , the support structure 665 may have a stripe shape (①, ②), as well as an island shape (③, ④), a zigzag shape (⑤), and the like.

The support structure 665 prevents the substrate from being bent in the connection interface region, thereby minimizing damage to the display device. In addition, the support structure 665 may prevent an electrical short circuit caused by aggregation of conductive particles. Accordingly, the display device employing the support structure 665 has improved mechanical stability.

Although the embodiments of the present specification have been described in detail with reference to the accompanying drawings, the present specification is not necessarily limited to these embodiments, and various modifications may be made within the scope without departing from the technical spirit thereof. Accordingly, the embodiments disclosed in the present specification are for explanation rather than limiting the technical spirit of the present invention, and the scope of the technical spirit of the present invention is not limited by these embodiments. Each feature of the various embodiments of the present invention may be partially or wholly combined or combined with each other, and may be technically variously linked and operated by those skilled in the art, and each embodiment may be implemented independently of each other or together in a related relationship may be carried out. The scope of protection of the present invention should be construed by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

Claims (18)

a display area in which sub-pixels are disposed;
a non-display area surrounding the display area; and
a connection interface area included in the non-display area;
In the connection interface area,
a first display pad; a second display pad further away from the display area than the first display pad; and a support structure disposed between the first display pad and the second display pad. The method of claim 1,
The support structure is provided to prevent the display device from being bent between the first display pad and the second display pad. The method of claim 1,
a driving circuit chip connected to the first display pad and the second display pad;
The driving circuit chip supplies a signal for driving the sub-pixels. The method of claim 3,
The driving circuit chip includes a circuit part and a connection part. The method of claim 4,
and an adhesive member for attaching the connection part and the first display pad and the second display pad to each other. The method of claim 5,
The adhesive member is
conductive particles; and an adhesive layer in which the conductive particles are dispersed. The method of claim 6,
The support structure is
A flexible display device having a shape in which the conductive particles are dispersed. The method of claim 7,
The support structure is a flexible display device having a stripe shape, an island shape, or a zigzag shape. The method of claim 1,
The support structure includes a first layer made of the same material as a planarization layer covering the thin film transistor (TFT) of the display area. The method of claim 9,
The support structure is made of the same material as the bank layer of the display area and further includes a second layer on the first layer. The method of claim 1,
The first display pad or the second display pad may include
a first electrode layer formed of the same material as a gate electrode of the thin film transistor (TFT) in the display area; a second electrode layer disposed on the first electrode layer and formed of the same material as a source or drain electrode of a thin film transistor (TFT) in the display area; and at least one of a third electrode layer on the second electrode layer. The method of claim 11,
The third electrode layer is made of the same material as the touch electrode. The method of claim 12,
The touch electrode is formed on an encapsulation part covering the sub-pixel. The method of claim 11,
The flexible display device further comprising an insulating layer between the first front layer and the second electrode layer. a flexible substrate on which sub-pixels are disposed;
a driving circuit chip having a circuit for controlling the sub-pixels;
a first pad column and a second pad column provided on the flexible substrate to be connected to the driving circuit chip; and
and a support structure positioned between the first pad row and the second pad row and provided to prevent the flexible substrate from being bent under the driving circuit chip. The method of claim 15,
conductive particles; and an adhesive member including an adhesive layer in which the conductive particles are dispersed. The method of claim 16,
The support structure has a shape in which the conductive particles are dispersed. The method of claim 17,
The support structure may have a stripe shape, an island shape, or a zigzag shape.

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