Stretchable display device

Abstract

Stretchable display device. The stretchable display device disclosed herein may include: a lower substrate; a plurality of first substrates, which are arranged on the lower substrate and define a plurality of sub-pixels, a plurality of second substrates, which connect adjacent first substrates among the plurality of first substrates; a plurality of inorganic insulating layers, which are arranged on the plurality of first substrates; an organic insulating layer, which is arranged on the plurality of first substrates in a manner covering the top surface and the side surface of the plurality of inorganic insulating layers; a plurality of first connecting lines, which are arranged on the organic insulating layers on the plurality of first substrates and on the second substrates extending along the first direction among the plurality of second substrates; a plurality of second connecting lines, which are arranged between the plurality of inorganic insulating layers and the organic insulating layers on the plurality of first substrates and on the second substrates extending along the second direction different from the first direction among the plurality of second substrates; and a step relief layer, which is arranged between the plurality of second connecting lines and the plurality of inorganic insulating layers.

Description

Technical Field

[0001] The present disclosure relates to a stretchable display device, and more particularly to a stretchable display device with improved reliability of connecting lines. Background Art

[0002] As display devices for monitors of computers, televisions, or cellular phones, there are organic light emitting display devices (OLEDs) that are self-light emitting devices and liquid crystal display devices (LCDs) that require a separate light source.

[0003] The application range of the display device is diversified to personal digital assistants and monitors of computers and televisions, and display devices having a large display area and reduced size and weight are being studied.

[0004] Furthermore, recently, a stretchable display device, which is formed by forming a display unit and wiring on a flexible substrate such as plastic as a flexible material to be stretched in a specific direction and changed in various forms, is receiving attention as a next-generation display device. Summary of the invention

[0005] The purpose of the present disclosure is to provide a stretchable display device.

[0006] Another object of the present disclosure is to provide a stretchable display device, which reduces the step of the insulating layer with which the connecting wire contacts when the stretchable display device is repeatedly stretched, thereby minimizing the separation of the connecting wire.

[0007] Still another object to be achieved by the present disclosure is to provide a stretchable display device which can fill an undercut portion formed on a substrate during a manufacturing process to suppress disconnection of a connection line.

[0008] Still another object to be achieved by the present disclosure is to provide a stretchable display device which minimizes damage to a thin film transistor, a capacitor, and a connection line disposed on a substrate.

[0009] Still another object to be achieved by the present disclosure is to provide a stretchable display device which minimizes the number of contact points provided on a first substrate to ensure an area of ​​the first substrate.

[0010] Still another object to be achieved by the present disclosure is to provide a stretchable display device that minimizes the resistance of a connection line.

[0011] The objects of the present disclosure are not limited to the above objects, and other objects not mentioned above can be clearly understood by those skilled in the art from the following description.

[0012] In order to achieve the above-mentioned purpose, according to one aspect of the present disclosure, a stretchable display device may include: a lower substrate; a plurality of first substrates, the plurality of first substrates are arranged on the lower substrate and define a plurality of sub-pixels, a plurality of second substrates, the plurality of second substrates connecting adjacent first substrates among the plurality of first substrates; a plurality of inorganic insulating layers, the plurality of inorganic insulating layers are arranged on the plurality of first substrates; an organic insulating layer, the organic insulating layer is arranged on the plurality of first substrates in a manner covering the top surface and the side surface of the plurality of inorganic insulating layers; a plurality of first connecting lines, the plurality of first connecting lines are arranged on the organic insulating layers on the plurality of first substrates and on the second substrates extending along the first direction among the plurality of second substrates; a plurality of second connecting lines, the plurality of second connecting lines are arranged between the plurality of inorganic insulating layers and the organic insulating layers on the plurality of first substrates, and on the second substrates extending in the second direction different from the first direction among the plurality of second substrates; and a step relief layer, the step relief layer is arranged between the plurality of second connecting lines and the plurality of inorganic insulating layers.

[0013] According to another aspect of the present disclosure, a stretchable display device may include: a plurality of rigid substrates, which are arranged on a soft substrate and include a plurality of display elements; a plurality of connecting substrates, which connect the plurality of rigid substrates between the plurality of rigid substrates; a plurality of inorganic insulating layers, which are arranged on the plurality of rigid substrates; a step relief layer, which is arranged to cover at least a portion of the plurality of inorganic insulating layers; an organic insulating layer, which is arranged on the step relief layer; a plurality of first connecting lines, which are arranged on the organic insulating layer and on a plurality of connecting substrates arranged along one direction; and a plurality of second connecting lines, which are arranged on a layer different from the plurality of first connecting lines and extend in a direction different from the plurality of first connecting lines.

[0014] Additional details of exemplary embodiments are included in the detailed description and the accompanying drawings.

[0015] According to the present disclosure, separation of connection lines caused when a stretchable display device is repeatedly extended is reduced.

[0016] According to the present disclosure, damage to the connection line caused by stress when the stretchable display device is extended is reduced.

[0017] According to the present disclosure, when a light emitting diode is transferred, damage to a thin film transistor, a capacitor, and a connection line disposed on a substrate can be reduced.

[0018] According to the present disclosure, the area for providing a circuit for driving pixels can be increased.

[0019] According to the present disclosure, the voltage drop of the connection line can be reduced.

[0020] The effects according to the present disclosure are not limited to the contents of the above examples, and more various effects are included in this specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and other aspects, features and other advantages of the present disclosure will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0022] Figure 1 is an exploded perspective view of a stretchable display device according to an exemplary embodiment of the present disclosure;

[0023] Figure 2 is an enlarged plan view of a stretchable display device according to an exemplary embodiment of the present disclosure;

[0024] Figure 3 is along Figure 2 A cross-sectional view taken along line III-III';

[0025] Figure 4 is a schematic cross-sectional view of one sub-pixel of a stretchable display device according to another exemplary embodiment of the present disclosure;

[0026] Figure 5 is a schematic cross-sectional view of a sub-pixel of a stretchable display device according to another exemplary embodiment of the present disclosure;

[0027] Figure 6 is a schematic cross-sectional view of a sub-pixel of a stretchable display device according to another exemplary embodiment of the present disclosure;

[0028] Figure 7 is along Figure 6 A cross-sectional view taken along line VII-VII';

[0029] Figure 8 is a schematic cross-sectional view of a sub-pixel of a stretchable display device according to another exemplary embodiment of the present disclosure;

[0030] Fig. 9 is a schematic cross-sectional view of one sub-pixel of a stretchable display device according to yet another exemplary embodiment of the present disclosure; and

[0031] Fig.10 is along Fig. 9 A cross-sectional view taken along line XX'. DETAILED DESCRIPTION

[0032] By referring to the exemplary embodiments described in detail below and the accompanying drawings, the advantages and features of the present disclosure and the methods for achieving the advantages and features will become clear. However, the present disclosure is not limited to the exemplary embodiments disclosed herein, but will be implemented in various forms. Exemplary embodiments are provided only by way of example so that those skilled in the art can fully understand the disclosure of the present disclosure and the scope of the present disclosure. Therefore, the present disclosure will only be limited by the scope of the appended claims.

[0033] The shapes, sizes, ratios, angles, quantities, etc. shown in the accompanying drawings for describing the exemplary embodiments of the present disclosure are merely examples, and the present disclosure is not limited thereto. Throughout the specification, similar reference numerals generally represent similar elements. In addition, in the following description of the present disclosure, detailed descriptions of known related technologies may be omitted to avoid making the subject matter of the present disclosure unclear unnecessarily. Terms such as "including", "having" and "consisting of..." used herein are generally intended to allow the addition of other components unless the term is used together with the term "only". Unless otherwise expressly stated, any reference to the singular may include the plural.

[0034] Even if not explicitly stated, components are interpreted as including normal margins of error.

[0035] When terms such as “on,” “over,” “lower,” and “next” are used to describe the positional relationship between two parts, unless these terms are used together with the term “immediately adjacent” or “directly,” one or more components may be located between the two components.

[0036] When an element or layer is referred to as being “on” another element or layer, the other layer or element can be directly disposed on the other element or interposed therebetween.

[0037] Although the terms "first", "second", etc. are used to describe various components, these components are not limited to these terms. These terms are only used to distinguish one component from other components. Therefore, in the technical concept of the present disclosure, the first component to be mentioned below may be the second component.

[0038] Like reference numerals generally refer to like elements throughout the specification.

[0039] The size and thickness of each component shown in the drawings are illustrated for convenience of description, and the present disclosure is not limited to the illustrated sizes and thicknesses of the components.

[0040] The features of the various embodiments of the present disclosure may be partially or completely adhered to or combined with each other, and may be technically interlocked and operated in various ways, and these embodiments may be performed independently or in association with each other.

[0041] Hereinafter, a light emitting display device according to an exemplary embodiment of the present disclosure will be described in detail with reference to the accompanying drawings.

[0042] <Stretchable Display Device>

[0043] A stretchable display device may be referred to as a display device that can display an image even if the display device is bent or stretched. Compared with ordinary display devices of the prior art, the stretchable display device may have high flexibility. Therefore, the shape of the stretchable display device can be freely changed according to the operation of the user to bend or extend the stretchable display device. For example, when the user holds the end of the stretchable display device to pull the stretchable display device, the stretchable display device may be stretched under the force of the user. Alternatively, when the user places the stretchable display device on an uneven wall surface, the stretchable display device may be set to bend according to the shape of the surface of the wall. Alternatively, when the force applied by the user is removed, the stretchable display device may return to its original shape.

[0044] Figure 1 is an exploded perspective view of a stretchable display device according to an embodiment of the present disclosure. Figure 1 The stretchable display device 100 includes: a lower substrate 110, a plurality of first substrates 111, a plurality of second substrates 120, a plurality of third substrates 121, a chip on film (COF) 130, a printed circuit board 140 and an upper substrate US.

[0045] The lower substrate 110 is a substrate that supports and protects multiple components of the stretchable display device 100. The lower substrate 110, which is a soft substrate, may be made of a bendable or stretchable insulating material. For example, the lower substrate 110 may be formed of a silicone rubber such as polydimethylsiloxane (PDMS) or an elastomer such as polyurethane (PU) or polytetrafluoroethylene (PTFE), and thus has flexibility. However, the material of the lower substrate 110 is not limited thereto.

[0046] The lower substrate 110 is a flexible substrate so as to be reversibly expanded and contracted. In addition, the elastic modulus of the lower substrate 110 may be several MPa to several hundred MPa, for example, 0.5 MPa to 1 MPa.

[0047] The lower substrate 110 may have a display area AA and a non-display area NA surrounding the display area AA.

[0048] The display area AA is an area where an image is displayed in the stretchable display device 100 and a display element and various driving elements for driving the display element are arranged in the display area AA. The display area AA includes a plurality of pixels including a plurality of sub-pixels. The plurality of pixels are arranged in the display area AA and include a plurality of display elements. The plurality of sub-pixels can be connected to various wirings (wiring lines) respectively. For example, each of the plurality of sub-pixels can be connected to various wirings such as a gate line, a data line, a high potential power line, a low potential power line, and a reference voltage line.

[0049] The non-display area NA is an area adjacent to the display area AA. The non-display area NA is adjacent to the display area AA to surround the display area AA. In the non-display area NA, an image is not displayed, and wiring and circuit units may be formed. For example, in the non-display area NA, a plurality of pads may be provided, and the pads may be respectively connected to a plurality of sub-pixels of the display area AA.

[0050] A plurality of first substrates 111 and a plurality of third substrates 121 are disposed on the lower substrate 110. The plurality of first substrates 111 may be disposed in the display area AA of the lower substrate 110, and the plurality of third substrates 121 may be disposed in the non-display area NA of the lower substrate 110. Figure 1 In the embodiment, the plurality of third substrates 121 are disposed on the upper side and the left side in the non-display area NA, but are not limited thereto, and the plurality of third substrates 121 may be disposed in any area of ​​the non-display area NA.

[0051] The plurality of first substrates 111 and the plurality of third substrates 121 are rigid substrates and are spaced apart from each other to be independently disposed on the lower substrate 110. The rigidity of the plurality of first substrates 111 and the plurality of third substrates 121 may be greater than that of the lower substrate 110. That is, the lower substrate 110 may have a greater flexibility property than the plurality of first substrates 111 and the plurality of third substrates 121, and the plurality of first substrates 111 and the plurality of third substrates 121 may have a more rigid property than the lower substrate 110.

[0052] The plurality of first substrates 111 and the plurality of third substrates 121 as the plurality of rigid substrates may be formed of a plastic material having flexibility, and may be formed of, for example, polyimide (PI), polyacrylate, or polyacetate. In this case, the plurality of first substrates 111 and the plurality of third substrates 121 may be formed of the same material, but are not limited thereto and may be formed of different materials.

[0053] The modulus of the plurality of first substrates 111 and the plurality of third substrates 121 may be 1000 times the modulus of the lower substrate 110, but is not limited thereto. For example, the elastic modulus of the plurality of first substrates 111 and the plurality of third substrates 121 may be 2 GPa to 9 GPa depending on transparency. More specifically, when the plurality of first substrates 111 and the plurality of third substrates 121 are transparent, the elastic modulus is 2 GPa, and when the plurality of first substrates 111 and the plurality of third substrates 121 are opaque, the elastic modulus is 9 GPa. Therefore, the plurality of first substrates 111 and the plurality of third substrates 121 may be a plurality of rigid substrates having rigidity compared to the lower substrate 110.

[0054] In some exemplary embodiments, the lower substrate 110 may be defined as including a plurality of first lower patterns and a plurality of second lower patterns. The plurality of first lower patterns are disposed in a region of the lower substrate 110 overlapping with the plurality of first substrates 111 and the plurality of third substrates 121. The plurality of second lower patterns may be disposed in a region other than a region where the plurality of first substrates 111 and the plurality of second substrates 121 are disposed, or may be disposed throughout the stretchable display device 100.

[0055] In this case, the modulus of the plurality of first lower patterns may be higher than that of the second lower patterns. For example, the plurality of first lower patterns may be formed of the same material as the plurality of first substrates 111, and the second lower patterns may be formed of a material having a lower modulus than that of the plurality of first substrates 111.

[0056] The COF 130 is a film on which various components are disposed on a base film 131 having ductility, and provides signals to a plurality of sub-pixels of the display area AA. The COF 130 may be bonded to a plurality of pads of a plurality of third substrates ST2 disposed in the non-display area NA, and provide a power supply voltage, a data voltage, or a gate voltage to a plurality of sub-pixels of the display area AA through the pads. The COF 130 includes a base film 131 and a driving IC 132. In addition, various components may be additionally disposed on the COF 130.

[0057] The base film 131 is a layer supporting the driving IC 132 of the COF 130. The base film 131 may be formed of an insulating material, and, for example, may be formed of an insulating material having flexibility.

[0058] The driver IC 132 is a component that processes data for displaying an image and a driving signal for processing the data. Figure 1 , although it is shown that the driving IC 132 is mounted by the COF 130 technology, it is not limited thereto, and the driving IC 132 may be mounted by a chip on glass (COG) or a tape carrier package (TCP).

[0059] exist Figure 1 In the embodiment, one third substrate 121 is disposed in the non-display area AA→NA at the upper side of the display area AA in a manner corresponding to one row of the first substrates 111 disposed in the display area, and one COF 130 is disposed for one third substrate 121, but is not limited thereto. That is, one third substrate 121 and one COF 130 may be disposed to correspond to a plurality of rows of the first substrates 111.

[0060] A controller such as an IC chip or a circuit unit may be mounted on the printed circuit board 140. In addition, a memory or a processor may also be mounted on the printed circuit board 140. The printed circuit board 140 is a component that transmits a signal for driving the display element from the controller to the display element. Figure 1 In the description, use of three printed circuit boards 140 is described, but the number of the printed circuit boards 140 is not limited thereto.

[0061] In the following, reference will be made to Figure 2 and Figure 3 The stretchable display device 100 according to an exemplary embodiment of the present disclosure is described in more detail.

[0062] <Plane and cross-sectional structure>

[0063] Figure 2 is an enlarged plan view of a stretchable display device according to an exemplary embodiment of the present disclosure. Figure 3 yes Figure 2 For ease of description, reference will also be made to Figure 1 Give a description.

[0064] Reference Figure 1 and Figure 2 , a plurality of first substrates 111 are disposed on the lower substrate 110 in the display area AA. The plurality of first substrates 111 are spaced apart from each other to be disposed on the lower substrate 110. For example, Figure 1 and Figure 2 As shown, a plurality of first substrates 111 may be disposed on the lower substrate 110 in a matrix form, but is not limited thereto.

[0065] Reference Figure 1 and Figure 2, a plurality of sub-pixels SPX configuring a plurality of pixels PX may be disposed on a plurality of first substrates 111, and a gate driver GD may be mounted on a third substrate 121 located on the left side of the display area AA among a plurality of third substrates 121. When various elements are manufactured on the first substrate 111, the gate driver GD may be formed on the third substrate 121 in a gate-in-plate (GIP) manner. Therefore, various circuit configurations of the gate driver GD such as various transistors, capacitors, and wirings may be disposed on the plurality of third substrates 121. However, the gate driver GD is not limited thereto and may be mounted in a chip-on-film (COF) manner. In addition, a plurality of third substrates 121 are also disposed in a non-display area NA located on the right side of the display area AA, and the gate driver GD may also be mounted in a plurality of third substrates 121 located on the right side of the display area AA.

[0066] Reference Figure 1 , the size of the plurality of third substrates 121 may be larger than the size of the plurality of first substrates 111. Specifically, the size of each of the plurality of third substrates 121 may be larger than the size of each of the plurality of first substrates 111. As described above, on each of the plurality of third substrates 121, a gate driver GD is provided. For example, one stage of the gate driver GD may be provided on each of the plurality of third substrates 121. Therefore, the area occupied by various circuit configurations configuring one stage of the gate driver GD may be relatively larger than the area of ​​the first substrate 111 on which the pixels PX are provided. As a result, the size of each of the plurality of third substrates 121 may be larger than the size of each of the plurality of first substrates 111.

[0067] Reference Figure 1 and Figure 2 , the plurality of second substrates 120 may be disposed between the plurality of first substrates 111, between the plurality of third substrates 121, or between the plurality of first substrates 111 and the plurality of third substrates 121. The plurality of second substrates 120 may be a substrate connecting adjacent first substrates 111, a substrate connecting adjacent third substrates 121, or a substrate connecting between the first substrate 111 and the third substrate 121 and may be referred to as a connecting substrate. The plurality of second substrates 120 may be formed simultaneously and integrally of the same material as the plurality of first substrates 111 or the plurality of third substrates 121, but is not limited thereto.

[0068] Reference Figure 2 , the step relief layer 190 is disposed on the plurality of first substrates 111. The step relief layer 190 is disposed to cover one end and the other end of the plurality of first substrates 111 on which the plurality of second connection lines 182 are disposed, so that the plurality of second connection lines 182 can be disposed on the step relief layer 190. Figure 3 The step mitigation layer 190 is described in more detail.

[0069] Reference Figure 2 , the plurality of second substrates 120 have a wave shape. For example, Figure 2 As shown, the plurality of second substrates 120 may have a sine wave shape. However, the shape of the plurality of second substrates 120 is not limited thereto, and the plurality of second substrates 120 may extend in a zigzag shape, or may be formed in various shapes such as a shape extending by connecting a plurality of rhombus-shaped substrates at the vertices. In addition, Figure 2 The number and shape of the plurality of second substrates 120 shown are exemplary, and the number and shape of the plurality of second substrates 120 may vary according to design.

[0070] Reference Figure 2 , a plurality of connection lines 180 are disposed in a straight line shape on the plurality of first substrates 111. Specifically, a plurality of first connection lines 181 and a plurality of second connection lines 182 may be continuously formed on the plurality of first substrates 111 to connect one end and the other end of the plurality of first substrates 111.

[0071] Reference Figure 2 On the plurality of second substrates 120, the plurality of connection lines 180 have a shape corresponding to the plurality of second substrates 120. That is, the plurality of connection lines 180 may have a sine wave shape. The plurality of connection lines 180 electrically connect the pads on the adjacent first substrates 111 among the plurality of first substrates 111, and extend between the pads in a wavy shape rather than a straight line. For example, Figure 2 As shown, the shape of the plurality of connection lines 180 is not limited thereto. For example, the plurality of connection lines 180 may extend in a zigzag pattern. In addition, the plurality of connection lines 180 may have various shapes such as a shape extending by connecting a plurality of diamond-shaped wirings 180 at vertices.

[0072] Reference Figure 3 , a plurality of inorganic insulating layers are disposed on the plurality of first substrates 111. For example, the plurality of inorganic insulating layers may include a buffer layer 112, a gate insulating layer 113, and an interlayer insulating layer 114, but is not limited thereto. Therefore, various inorganic insulating layers may be additionally disposed on the plurality of first substrates 111, or one or more of the buffer layer 112, the gate insulating layer 113, and the interlayer insulating layer 114 may be omitted.

[0073] Reference Figure 3, a buffer layer 112 is disposed on the plurality of first substrates 111. The buffer layer 112 is formed on the plurality of first substrates 111 to protect the various components of the stretchable display device 100 from moisture H2O and oxygen O2 penetrating from the outside of the lower substrate 110 and the plurality of first substrates 111. The buffer layer 112 may be composed of an insulating material and, for example, a single layer or double layer configuration of an inorganic layer formed of silicon nitride (SiNx), silicon oxide (SiOx), and silicon oxynitride (SiON). However, depending on the structure or characteristics of the stretchable display device 100, the buffer layer 112 may be omitted.

[0074] In this case, the buffer layer 112 may be formed only in the region overlapping with the plurality of first substrates 111 and the plurality of third substrates 121. As described above, the buffer layer 112 may be formed of an inorganic material so that the buffer layer 112 may be easily broken or damaged in the process of stretching the stretchable display device 100. Therefore, the buffer layer 112 is not formed in the region between the plurality of first substrates 111 and the plurality of third substrates 121. Instead, the buffer layer 112 is patterned to have the shape of the plurality of first substrates 111 and the plurality of third substrates 121 disposed only above the plurality of first substrates 111 and the plurality of third substrates 121. Therefore, in the stretchable display device 100 according to the exemplary embodiment of the present disclosure, the buffer layer 112 is formed only in the region overlapping with the plurality of first substrates 111 and the plurality of third substrates 121 as rigid substrates. Therefore, even if the stretchable display device 100 is bent or stretched to deform, damage to the buffer layer 112 may be suppressed.

[0075] Reference Figure 3 , a transistor 150 including a gate 151 , an active layer 152 , a source 153 and a drain 154 is formed on the buffer layer 112 .

[0076] First, refer to Figure 3 , the active layer 152 is disposed on the buffer layer 112. For example, the active layer 152 may be formed of an oxide semiconductor or amorphous silicon (a-Si), polycrystalline silicon (poly-Si), or an organic semiconductor.

[0077] The gate insulating layer 113 is disposed on the active layer 152. The gate insulating layer 113 is a layer for electrically insulating the gate electrode 151 from the active layer 152, and may be formed of an insulating material. For example, the gate insulating layer 113 may be formed as a single layer of silicon nitride (SiNx) or silicon oxide (SiOx) as an inorganic material or a multilayer of silicon nitride (SiNx) or silicon oxide (SiOx), but is not limited thereto.

[0078] The gate 151 is disposed on the buffer layer 112. The gate 151 is disposed to overlap the active layer 152. The gate 151 may be any one of various metal materials (e.g., any one of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu)) or an alloy of two or more thereof, or a multilayer thereof, but is not limited thereto.

[0079] The interlayer insulating layer 114 is disposed on the gate electrode 151. The interlayer insulating layer 114 is a layer that insulates the gate electrode 151 from the source electrode 153 and the drain electrode 154, and may be formed of an inorganic material (similar to the buffer layer 112). For example, the interlayer insulating layer 114 may be configured of a single layer of silicon nitride (SiNx) or silicon oxide (SiOx) as an inorganic material or a multilayer of silicon nitride (SiNx) or silicon oxide (SiOx), but is not limited thereto.

[0080] The source electrode 153 and the drain electrode 154 contacting the active layer 152 are disposed on the interlayer insulating layer 114. The source electrode 153 and the drain electrode 154 are disposed on the same layer in a manner spaced apart from each other. The source electrode 153 and the drain electrode 154 may contact the active layer 152 to be electrically connected to the active layer 152. The source electrode 153 and the drain electrode 154 may be any one of various metal materials such as molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu), or an alloy of two or more thereof, or a multilayer thereof, but are not limited thereto.

[0081] In addition, the gate insulating layer 113 and the interlayer insulating layer 114 are patterned in such a manner that they are formed only in the region overlapping the plurality of first substrates 111. Similar to the buffer layer 112, the gate insulating layer 113 and the interlayer insulating layer 114 are also formed of an inorganic material, so that the gate insulating layer 113 and the interlayer insulating layer 114 are also easily broken and damaged during the process of stretching the stretchable display device 100. Therefore, the gate insulating layer 113 and the interlayer insulating layer 114 are not formed in the region between the plurality of first substrates 111, but are patterned to have the shape of the plurality of first substrates 111 formed only above the plurality of first substrates 111.

[0082] exist Figure 3 In the present invention, even among various transistors that can be included in the stretchable display device 100, only a driving transistor is shown for ease of description, but a switching transistor or a capacitor may also be included in the display device. In addition, in the specification, although the transistor 150 is described as having a coplanar structure, various transistors such as a staggered transistor may also be used.

[0083] Reference Figure 3, a gate pad 171 among the plurality of pads 170 is disposed on the gate insulating layer 113. The gate pad 171 is a pad that transmits a gate signal to a plurality of sub-pixels SPX. The gate signal may be transmitted from the gate pad 171 to the gate 151 through a gate line formed on the first substrate 111. The gate pad 171 may be formed of the same material as the gate 151 on the same layer. However, the present disclosure is not limited thereto, and the gate pad 171 may be disposed on a different layer from the gate 151 and may be formed of a different material therefrom.

[0084] Reference Figure 3 , the step relief layer 190 is disposed on the interlayer insulating layer 114. The step relief layer 190 is disposed between the plurality of second connection lines 182 on the plurality of first substrates 111 and the plurality of inorganic insulating layers such as the buffer layer 112, the gate insulating layer 113, and the interlayer insulating layer 114. By doing so, the step relief layer 190 can relieve the steps of the plurality of second connection lines 182 disposed on the side surfaces of the plurality of inorganic insulating layers.

[0085] The step mitigation layer 190 may be formed of an organic material. For example, the step mitigation layer 190 may be formed of the same material as the planarization layer 115 or an organic material having stronger adhesion to the plurality of second connection lines 182 than the planarization layer 115, but is not limited thereto.

[0086] Reference Figure 3 , the step relief layer 190 may be disposed on the plurality of first substrates 111 in a manner covering a portion of the side surfaces and top surfaces of the plurality of inorganic insulating layers. The step relief layer 190 surrounds the buffer layer 112, the gate insulating layer 113, and the interlayer insulating layer 114 together with the plurality of first substrates 111 between the plurality of first substrates 111 and the plurality of second connection lines 182. Specifically, the step relief layer 190 may be disposed in a manner covering the top and side surfaces of the interlayer insulating layer 114, the side surfaces of the gate insulating layer 113, the side surfaces of the buffer layer 112, and a portion of the top surfaces of the plurality of first substrates 111. Therefore, the step relief layer 190 may supplement steps on the side surfaces of the buffer layer 112, the gate insulating layer 113, and the interlayer insulating layer 114 between the plurality of first substrates 111 and the plurality of second connection lines 182. In addition, the step relief layer 190 may increase the adhesion strength between the step relief layer 190 and the plurality of second connection lines 182 disposed on the side surfaces of the step relief layer 190.

[0087] Reference Figure 3, a data pad 172 among the plurality of pads 170 is disposed on the interlayer insulating layer 114. The data pad 172 is a pad that transmits a data signal to the plurality of sub-pixels SPX. The data signal may be transmitted from the data pad 172 to the source electrode 153 or the drain electrode 154 through a data line formed on the first substrate 111. The data pad 172 may be formed on the same layer from the same material as the source electrode 153 and the drain electrode 154. However, the present disclosure is not limited thereto, and the data pad 172 may be disposed on a different layer from the source electrode 153 and the drain electrode 154, and may be formed from a different material therefrom.

[0088] Reference Figure 3 , a planarization layer 115 is formed on the transistor 150, the interlayer insulating layer 114 and the step relief layer 190. The planarization layer 115 planarizes the upper portion of the transistor 150. The planarization layer 115 may be configured by a single layer or a multilayer, and may be formed by an organic material. Therefore, the planarization layer 115 may also be referred to as an organic insulating layer. For example, the planarization layer 115 may be formed by an acrylic organic material, but is not limited thereto. The planarization layer 115 may be formed by the same material as the step relief layer 190, or by an organic material having stronger adhesion to the plurality of first connection lines 181 than the step relief layer 190, but is not limited thereto.

[0089] Reference Figure 3 , the planarization layer 115 is disposed between the plurality of first substrates 111 and the first connection lines 181 in a manner of covering the top and side surfaces of the buffer layer 112, the gate insulation layer 113, and the interlayer insulation layer 114. The planarization layer 115 is disposed to surround the buffer layer 112, the gate insulation layer 113, and the interlayer insulation layer 114 together with the plurality of first substrates 111. Specifically, the planarization layer 115 may be disposed in a manner of covering the top and side surfaces of the interlayer insulation layer 114, the side surfaces of the gate insulation layer 113, the side surfaces of the buffer layer 112, and a portion of the top surfaces of the plurality of first substrates 111. Therefore, the planarization layer 115 may supplement the steps on the side surfaces of the buffer layer 112, the gate insulation layer 113, and the interlayer insulation layer 114 between the plurality of first substrates 111 and the plurality of first connection lines 181. In addition, the planarization layer 115 may increase the adhesion strength between the planarization layer 115 and the plurality of first connection lines 181 disposed on the side surfaces of the planarization layer 115.

[0090] Meanwhile, the slope of the side surface of the planarization layer 115 may be gentler than the slopes formed of the side surfaces of the buffer layer 112 , the gate insulating layer 113 , and the interlayer insulating layer 114 , but is not limited thereto.

[0091] In some exemplary embodiments, a passivation layer may be formed between the transistor 150 and the planarization layer 115. That is, the passivation layer may be formed to cover the transistor 150 to protect the transistor 150 from the penetration of moisture and oxygen. The passivation layer may be formed of an inorganic material and configured of a single layer or multiple layers, but is not limited thereto.

[0092] Reference Figure 2 and Figure 3 The connection line 180 refers to a wiring that electrically connects pads on the plurality of first substrates 111 or the plurality of third substrates 121. The connection line 180 is provided on the first substrate 111 and the plurality of second substrates 120.

[0093] The connection line 180 includes a first connection line 181 and a second connection line 182. The first connection line 181 and the second connection line 182 are arranged on the plurality of first substrates 111 and the plurality of second substrates 120. Specifically, the first connection line 181 refers to a wiring arranged on the second substrate 120 extending in the X-axis direction as the first direction among the plurality of first substrates 111 and the plurality of second substrates 120. The second connection line 182 refers to a wiring arranged on the second substrate 120 extending in the Y-axis direction as the second direction among the plurality of first substrates 111 and the plurality of second substrates 120. The connection line 180 may be formed of a metal material such as copper (Cu), aluminum (Al), titanium (Ti) and molybdenum or a stacked structure of metal materials such as copper / molybdenum titanium (Cu / Moti) or titanium / aluminum / titanium (Ti / Al / Ti), but is not limited thereto.

[0094] The plurality of first connection lines 181 and the plurality of second connection lines 182 may be made of different materials. For example, the plurality of first connection lines 181 may be made of copper (Cu), and the plurality of second connection lines 182 may be made of a stacked structure of titanium / aluminum / titanium (Ti / Al / Ti).

[0095] The plurality of first connection lines 181 and the plurality of second connection lines 182 may be disposed on different layers. For example, the plurality of first connection lines 181 may be disposed on the planarization layer 115 on the plurality of first substrates 111, and the plurality of second connection lines 182 may be disposed on the plurality of first substrates 111 on the step relief layer 190 disposed between the plurality of inorganic insulating layers and the planarization layer 115. Therefore, the plurality of first connection lines 181 and the plurality of second connection lines 182 may intersect on the plurality of first substrates 111.

[0096] In the case of a general display device, various wirings such as a plurality of gate lines and a plurality of data lines extend between a plurality of sub-pixels having a straight line shape, and a plurality of sub-pixels are connected to one signal line. Therefore, in a general display device, various wirings such as a gate line, a data line, a high potential power line, and a reference voltage line extend from one side of the display device to the other side without being disconnected on a substrate.

[0097] In contrast, in the stretchable display device 100 according to the exemplary embodiment of the present disclosure, various wirings such as a gate line, a data line, a high potential power line, or a reference voltage line having a straight line shape, which are considered to be used for a general display device, may be provided only on the plurality of first substrates 111 and the plurality of third substrates 121. That is, in the stretchable display device 100 according to the exemplary embodiment of the present disclosure, only straight line wirings are provided on the plurality of first substrates 111 and the plurality of third substrates 121.

[0098] In the stretchable display device 100 according to the exemplary embodiment of the present disclosure, in order to connect discontinuous wirings on the first substrate 111 or the third substrate 121, two adjacent first substrates 111 or two adjacent third substrates 121 may be connected by a connection line 180. Specifically, the first connection line 181 electrically connects two first substrates 111, two third substrates 121, and pads on the first substrate 111 and the third substrate 121 that are adjacent to each other in the X-axis direction as the first direction. In addition, the second connection line 182 electrically connects two first substrates 111, two third substrates 121, and the first substrate 111 and the third substrate 121 that are adjacent to each other in the Y-axis direction as the second direction. Therefore, the stretchable display device 100 according to the exemplary embodiment of the present disclosure may include a plurality of connection lines 180 that electrically connect various wirings such as a gate line, a data line, a high potential power line, and a reference voltage line between the plurality of first substrates 111, between the plurality of third substrates 121, and between the plurality of first substrates 111 and the plurality of third substrates 121. For example, the gate line may be arranged on a plurality of first substrates 111 arranged adjacent to each other in the X-axis direction, and the gate pads 171 may be arranged at both ends of the gate line. In this case, the plurality of gate pads 171 on the plurality of first substrates 111 adjacent to each other in the X-axis direction may be connected to each other by the first connection line 181 used as the gate line. Therefore, the gate line arranged on the plurality of first substrates 111 and the first connection line 181 arranged on the third substrate 121 may be used as one gate line. In addition, as described above, among all the various wirings that may be included in the stretchable display device 100, wirings extending in the X-axis direction such as emission signal lines, low potential power lines, and high potential power lines may also be electrically connected by the first connection line 181.

[0099] Reference Figure 2and Figure 3 , the first connection line 181 can be connected to the pads on two first substrates 111 arranged side by side among the pads on the multiple first substrates 111 arranged adjacent to each other in the X-axis direction. The first connection line 181 can be used as a gate line, a transmission signal line, a high potential power line, or a low potential power line, but is not limited thereto. For example, the first connection line 181 can be used as a gate line and electrically connected to the gate pads 171 on the two first substrates 111 arranged side by side in the X-axis direction. Therefore, as described above, the gate pads 171 on the multiple first substrates 111 arranged in the X-axis direction can be connected by the first connection line 181 used as a gate line, and a gate signal can be sent.

[0100] Reference Figure 2 , the second connection line 182 can connect two first substrates 111 arranged side by side among the multiple first substrates 111 arranged adjacent to each other in the Y-axis direction. The second connection line 182 can be used as a data line, a high potential power line, a low potential power line, or a reference voltage line, but is not limited thereto. For example, the second connection line 182 can be used as a data line and electrically connects the data line on the two first substrates 111 arranged side by side in the Y-axis direction. Therefore, as described above, the data lines above the multiple first substrates 111 arranged in the Y-axis direction can be connected and send a data signal through the multiple second connection lines 182 used as data lines.

[0101] Reference Figure 1 The connection line 180 may also include wiring connecting pads on multiple first substrates 111 and multiple third substrates 121 or connecting pads on two third substrates 121 arranged side by side.

[0102] The first connection line 181 may be formed to extend to the top surface of the second substrate 120 while contacting the top surface and the side surface of the planarization layer 115 disposed on the first substrate 111. In addition, the second connection line 182 may be formed to extend to the top surface of the second substrate 120 while contacting the top surface and the side surface of the step mitigation layer 190 disposed on the first substrate 111. The arrangement and effects of the first connection line 181 and the second connection line 182 will be described in more detail below.

[0103] In addition, even if not Figure 3 As shown in FIG. 1 , a bank may also be formed on the first connection pad CP1, the second connection pad CP2, the connection line 180, and the planarization layer 115. The bank may be used to distinguish adjacent sub-pixels SPX.

[0104] Reference Figure 3, the LED 160 is disposed on the first connection pad CP1 and the second connection pad CP2. The LED 160 includes an n-type layer 161, an active layer 162, a p-type layer 163, an n-electrode 164, and a p-electrode 165. The LED 160 of the stretchable display device 100 according to the exemplary embodiment of the present disclosure has a flip-chip structure in which the n-electrode 164 and the p-electrode 165 are formed on one surface.

[0105] The n-type layer 161 may be formed by implanting n-type impurities into gallium nitride (GaN) having excellent crystallinity. The n-type layer 161 may be disposed on a separate base substrate formed of a material capable of emitting light.

[0106] The active layer 162 is disposed on the n-type layer 161. The active layer 162 is a light emitting layer that emits light in the LED 160 and may be formed of a nitride semiconductor such as indium gallium nitride (InGaN). The p-type layer 163 is disposed on the active layer 162. The p-type layer 163 may be formed by injecting p-type impurities into gallium nitride (GaN).

[0107] As described above, the LED 160 according to the exemplary embodiment of the present disclosure is manufactured by sequentially stacking the n-type layer 161, the active layer 162, and the p-type layer 163, and then etching a predetermined portion to form the n-electrode 164 and the p-electrode 165. In this case, the predetermined portion is a space for separating the n-electrode 164 and the p-electrode 165 from each other, and the predetermined portion may be etched to expose a portion of the n-type layer 161. In other words, the surface of the LED 160 provided with the n-electrode 164 and the p-electrode 165 is not a flat surface, but has different height levels.

[0108] As described above, in the etched region, in other words, on the n-type layer 161 exposed by the etching process, an n-electrode 164 is provided. The n-electrode 164 may be formed of a conductive material. In addition, in the unetched region, in other words, on the p-type layer 163, a p-electrode 165 is provided. The p-electrode 165 may also be formed of a conductive material, and may be formed of the same material as the n-electrode 164, for example.

[0109] The adhesive layer AD is disposed on the top surface of the first connection pad CP1 and the second connection pad CP2 and between the first connection pad CP1 and the second connection pad CP2 so that the LED 160 can be bonded to the first connection pad CP1 and the second connection pad CP2. In this case, the n-electrode 164 can be disposed on the second connection pad CP2, and the p-electrode 165 can be disposed on the first connection pad CP1.

[0110] The adhesive layer AD may be a conductive adhesive layer in which conductive balls are dispersed in an insulating base member. Therefore, when heat or pressure is applied to the adhesive layer AD, the conductive balls are electrically connected in the portion to which heat or pressure is applied to have conductive properties, and the area not pressurized may have insulating properties. For example, the n-electrode 164 is electrically connected to the second connection line 182 by means of the adhesive layer AD, and the p-electrode 165 is electrically connected to the first connection line 181 by means of the adhesive layer AD. That is, after applying the adhesive layer AD on the first connection pad CP1 and the second connection pad CP2 using an inkjet method, the LED 160 is transferred to the adhesive layer AD, and the LED 160 is pressurized and heated. By doing so, the first connection pad CP1 is electrically connected to the p-electrode 165, and the second connection pad CP2 is electrically connected to the n-electrode 164. However, the rest of the adhesive layer AD except for a portion of the adhesive layer AD disposed between the n-electrode 164 and the second connection pad CP2 and a portion of the adhesive layer AD disposed between the p-electrode 165 and the first connection pad CP1 has insulating properties. Meanwhile, the adhesive layer AD may be divided to be disposed on the first and second connection pads CP1 and CP2, respectively.

[0111] As described above, the stretchable display device 100 according to the exemplary embodiment of the present disclosure has a structure in which the LED 160 is provided on the lower substrate 110 provided with the transistor 150. Therefore, when the stretchable display device 100 is turned on, different voltage levels applied to the first connection pad CP1 and the second connection pad CP2 are transmitted to the n-electrode 164 and the p-electrode 165, so that the LED 160 emits light.

[0112] Reference Figure 3 , the upper substrate US is disposed on the LED 160 and the lower substrate 110 .

[0113] The upper substrate US is a substrate that supports various components disposed below the upper substrate US. Specifically, the upper substrate US is formed by coating a material configuring the upper substrate US on the lower substrate 110 and the first substrate 111 and then curing the material disposed in contact with the lower substrate 110, the first substrate 111, the second substrate 120, and the connection line 180.

[0114] The upper substrate US as a flexible substrate may be made of a bendable or stretchable insulating material. The upper substrate US is a flexible substrate, and thus can be reversibly expanded and contracted. In addition, the elastic modulus of the upper substrate may be several MPa to several hundred MPa, and the elongation fracture rate may be 100% or more. The thickness of the upper substrate US may be 10 μm to 1 mm, but is not limited thereto.

[0115] The upper substrate US may be formed of the same material as the lower substrate 110. For example, the upper substrate US may be formed of silicone rubber such as polydimethylsiloxane (PDMS) or an elastomer such as polyurethane (PU) or polytetrafluoroethylene (PTFE), and thus has flexibility. However, the material of the upper substrate US is not limited thereto.

[0116] At the same time, although not Figure 3 , but the polarizing layer may also be provided on the upper substrate US. The polarizing layer may perform the function of polarizing light incident from the outside of the stretchable display device 100 to reduce external light reflection. In addition, an optical film other than the polarizing layer may be provided on the upper substrate US.

[0117] In the prior art stretchable display device, a planarization layer formed of an organic insulating material is disposed on a plurality of inorganic insulating layers such as a buffer layer, a gate insulating layer, and an interlayer insulating layer, without covering the side surfaces of the plurality of inorganic insulating layers. Therefore, the connecting wire is disposed in contact with the side surfaces of the plurality of inorganic insulating layers. However, if a patterning process (i.e., an etching process) is performed on the plurality of inorganic insulating layers, steps may be formed on the sides of the plurality of inorganic insulating layers. That is, the slope of the side surfaces of the plurality of inorganic insulating layers formed by the etching process is very steep, so that when the connecting wire is formed directly on the sides of the plurality of inorganic insulating layers, the connecting wire may be disconnected.

[0118] Therefore, in the stretchable display device 100 according to the exemplary embodiment of the present disclosure, the planarization layer 115 is provided between the plurality of first substrates 111 and the first connection line 181 in a manner covering the side surfaces of the plurality of inorganic insulating layers. By doing so, the steps of the side surfaces of the plurality of inorganic insulating layers can be supplemented. Specifically, the planarization layer 115 can be provided between the plurality of first substrates 111 and the first connection line 181 in a manner covering the top surfaces and side surfaces of the plurality of inorganic insulating layers (i.e., the side surfaces of the buffer layer 112, the side surfaces of the gate insulating layer 113, and the side surfaces and a portion of the top surface of the interlayer insulating layer 114). When the planarization layer 115 is provided to cover the side surfaces of the plurality of inorganic insulating layers, the side surfaces of the planarization layer 115 can be formed to have a slope that is gentler than the slope formed by the side surfaces of the plurality of inorganic insulating layers. Therefore, the plurality of first connection lines 181 disposed on the planarization layer 115 are disposed to have a relatively gentle slope, so that cracks generated in the plurality of first connection lines 181 when forming the plurality of first connection lines 181 can be reduced. In addition, when the stretchable display device 100 is extended, stress generated in the plurality of first connection lines 181 is reduced, and cracks of the plurality of first connection lines 181 or separation of the first connection lines 181 from the side surface of the planarization layer 115 can be suppressed.

[0119] In addition, in the stretchable display device 100 according to the exemplary embodiment of the present disclosure, the step relief layer 190 is disposed at one end and the other end of the plurality of first substrates 111 on which the plurality of second connection lines 182 are disposed. In addition, the step relief layer 190 is disposed between the plurality of first substrates 111 and the second connection lines 182 in a manner covering the side surfaces of the plurality of inorganic insulating layers to supplement the steps of the side surfaces of the plurality of inorganic insulating layers. The step relief layer 190 may be disposed between the plurality of first substrates 111 and the second connection lines 182 in a manner covering the top surfaces and side surfaces of the plurality of inorganic insulating layers (i.e., the side surfaces of the buffer layer 112, the side surfaces of the gate insulating layer 113, and a portion of the side surfaces and top surfaces of the interlayer insulating layer 114). In this case, the step relief layer 190 is disposed to have a slope that is gentler than the slope formed by the side surfaces of the plurality of inorganic insulating layers, so that the plurality of second connection lines 182 disposed on the step relief layer 190 may be disposed to have a relatively gentle slope. Therefore, cracks generated in the plurality of second connection lines 182 when forming the plurality of second connection lines 182 can be reduced. In addition, when the stretchable display device 100 is extended, stress generated in the plurality of second connection lines 182 is reduced, and cracks in the plurality of second connection lines 182 or separation of the second connection lines 182 from the side surface of the step relief layer 190 can be suppressed.

[0120] When a plurality of first connection lines and a plurality of second connection lines are arranged on the same layer in a stretchable display device, the plurality of first connection lines and the plurality of second connection lines do not intersect on the plurality of first substrates. Therefore, at least one of the plurality of first connection lines and the plurality of second connection lines arranged at one end of the plurality of first substrates is connected to a wiring or a pad arranged on another layer through a contact hole arranged on the plurality of first substrates, thereby being electrically connected to the plurality of first connection lines and the plurality of second connection lines arranged at the other end of the plurality of first substrates. However, when the plurality of first connection lines and the plurality of second connection lines are connected to a wiring or a pad arranged on another layer through a contact hole, the contact resistance increases. In addition, since it is necessary to consider the process margin for forming contact holes, the area of ​​the plurality of first substrates on which pixels, drive circuits or wiring are arranged can be reduced by the area of ​​the plurality of first substrates occupied by the contact holes.

[0121] Therefore, in the stretchable display device 100 according to the exemplary embodiment of the present disclosure, a plurality of first connection lines 181 and a plurality of second connection lines 182 are arranged on different layers in a manner of overlapping and intersecting on a plurality of first substrates 111. That is, a plurality of first connection lines 181 are continuously formed on a plurality of first substrates 111 and a plurality of second substrates 120, but are not electrically connected through a pad or wiring arranged on another layer. In addition, a plurality of second connection lines 182 are continuously formed on a plurality of first substrates 111 and a plurality of second substrates 120, but are not electrically connected through a pad or wiring arranged on another layer. The plurality of first connection lines 181 and the plurality of second connection lines 182 may be connected to another configuration through a contact hole to send a signal to another circuit configuration such as a transistor 150. However, contact holes are not used for connection between the plurality of first connection lines 181 and the plurality of second connection lines 182. Therefore, in the stretchable display device 100 according to the exemplary embodiment of the present disclosure, the contact resistance of the plurality of first connection lines 181 and the plurality of second connection lines 182 can be reduced. In addition, the area of ​​pixels, driving circuits, and wirings that can be provided in the plurality of first substrates 111 can be increased. In addition, the number of contact holes provided on the plurality of first substrates 111 is reduced, so that the pixels, driving circuits, and wirings can be designed more freely.

[0122] In addition, in the stretchable display device 100 according to the exemplary embodiment of the present disclosure, the planarization layer 115 and the step relief layer 190 are arranged to cover the side of the plurality of inorganic insulating layers. Therefore, the disconnection of the connection line 180 caused when the connection line 180 is formed can be reduced. Specifically, during the process of etching the buffer layer 112, the gate insulating layer 113 and the interlayer insulating layer 114, the portions of the plurality of first substrates 111 adjacent to the ends of the plurality of inorganic insulating layers are also etched to have an undercut shape. The planarization layer 115 and the step relief layer 190 can be arranged to cover one side and the other side of the plurality of first substrates 111. Therefore, the planarization layer 115 and the step relief layer 190 can complement the undercut shape formed in the portion adjacent to the ends of the plurality of inorganic insulating layers. In addition, the first connection line 181 is arranged on the planarization layer 115 and the second connection line 182 is arranged on the step relief layer 190, so that the disconnection of the connection line 180 caused when the connection line 180 is formed can be reduced.

[0123] <Layout of step relief layer>

[0124] Figure 4 is a schematic cross-sectional view of one sub-pixel of a stretchable display device according to another exemplary embodiment of the present disclosure. Figure 4 The stretchable display device 400 and Figures 1 to 3The only difference between the stretchable display devices 100 is the step mitigation layer 490, the planarization layer 415 and the plurality of connection lines 480, while other configurations are substantially the same, so redundant description will be omitted.

[0125] Reference Figure 4 , the step relief layer 490 is arranged to cover the top surface and side surface of multiple inorganic insulating layers. That is, the step relief layer 490 can be arranged to cover multiple inorganic insulating layers. Specifically, the step relief layer 490 is arranged on multiple first substrates 111 to cover the top surface and side surface of the interlayer insulating layer 114, the side surface of the gate insulating layer 113, the side surface of the buffer layer 112, and a portion of the top surface of the multiple first substrates 111. By doing so, the step relief layer 490 can be arranged to surround multiple inorganic insulating layers together with the multiple first substrates 111. In this case, the slope of the side surface of the step relief layer 490 can be gentler than the slope of the side surface formed by the multiple inorganic insulating layers, but is not limited thereto.

[0126] Reference Figure 4 , the data pad 472 among the plurality of pads 470 is disposed on the step mitigation layer 490. Therefore, the data pad 472 may be connected to the plurality of second connection lines 482 on the step mitigation layer 490. The data pad 472 may be formed of the same material as the second connection line 482.

[0127] Reference Figure 4 , a plurality of second connection lines 482 are disposed on the step relief layer 490. Specifically, the plurality of second connection lines 482 are connected to the data pads 472 on the step relief layer 490 to have a flat top surface on the top surface of the step relief layer 490 and may be disposed to contact a portion of the side surface and the top surface of the step relief layer 490.

[0128] Reference Figure 4 , the planarization layer 415 is disposed on the plurality of pads 470 and the step relief layer 490. The planarization layer 415 is disposed to cover a portion of the top surface of the step relief layer 490, the data pads 472 of the plurality of pads 470, and the top surface of the plurality of second connection lines 482. In this case, the slope of the side surface of the planarization layer 415 may be equal to the slope of the side surface of the step relief layer 490, but is not limited thereto. In addition, even in Figure 4 , it is shown that the planarization layer 415 covers only the top surface of the step mitigation layer 490 , but the present disclosure is not limited thereto, and the planarization layer 415 may also be provided to cover a portion of the side surface of the step mitigation layer 490 .

[0129] Reference Figure 4, a plurality of first connection lines 181 are disposed on the planarization layer 415. The plurality of first connection lines 181 are connected to the gate pad through contact holes formed in the planarization layer 415 and the step relief layer 490. The plurality of first connection lines 181 are in contact with the top and side surfaces of the planarization layer 415 and the side surface of the step relief layer 490, and may extend to the top surfaces of the plurality of second substrates.

[0130] In a stretchable display device 400 according to another exemplary embodiment of the present disclosure, a step relief layer 490 and a planarization layer 415 are disposed on a plurality of inorganic insulating layers such as a buffer layer 112, a gate insulating layer 113, an interlayer insulating layer 114, and a transistor 150. By doing so, during the transfer process of the LED 160, components disposed below the step relief layer 490 and the planarization layer 415 can be protected. When the LED 160 is disposed in the stretchable display device 400 by being transferred thereto, the LED 160 can be disposed by pressurizing the LED 160 above the stretchable display device 400. In this case, the transistor 150, various wirings, and the connection line 480 disposed below the LED 160 may be damaged due to pressure. Therefore, the step relief layer 490 and the planarization layer 415 are disposed on the buffer layer 112, the gate insulating layer 113, the interlayer insulating layer 114, and the transistor 150, so that when the LED 160 is transferred, the stress caused by pressurization can be relieved. Therefore, damage to the transistor 150 , various wirings, and the connection line 480 disposed under the step mitigation layer 490 and the planarization layer 415 may be reduced.

[0131] <Planarization Layer Including Recesses>

[0132] Figure 5 is a schematic cross-sectional view of a sub-pixel of a stretchable display device according to yet another exemplary embodiment of the present disclosure. Figure 5 The stretchable display device 500 and Figure 4 The only difference between the stretchable display device 400 is the planarization layer 515 and the connection pad CP', and other configurations are substantially the same, so repeated description is omitted.

[0133] Reference Figure 5 , the planarization layer 515 includes a groove 515a. The groove 515a may be provided on a portion of the top surface of the planarization layer 515. The groove 515a may have a predetermined depth so that the LED 160 may be located in the groove 515a.

[0134] Reference Figure 5, the connection pad CP' may be provided according to the shape of the groove 515a. Specifically, the first connection pad CP1' and the second connection pad CP2' may extend along a portion of the inner side surface and the top surface of the groove 515a on a portion of the top surface of the planarization layer 515. Therefore, the first connection pad CP1' and the second connection pad CP2' may be provided to mainly cover the inner side surface and the top surface of the groove 515a. However, the present disclosure is not limited thereto, and the first connection pad CP1' and the second connection pad CP2' may be provided to cover only a portion of the inner side surface or a portion of the top surface of the groove 515a.

[0135] Reference Figure 5 , the LED 160 may be disposed in the groove 515a of the planarization layer 515. The LED 160 may be electrically connected to the first and second connection pads CP1' and CP2' disposed in the groove 515a of the planarization layer 515.

[0136] In the stretchable display device 500 according to still another exemplary embodiment of the present disclosure, the groove 515a is provided in a portion of the top surface of the planarization layer 515 so that the LED 160 is aligned during the process of transferring the LED 160. Specifically, when the groove 515a is provided in a portion of the top surface of the planarization layer 515, during the process of transferring the LED 160, the LED 160 may be transferred according to the shape of the groove 515a. That is, the groove 515a of the planarization layer 515 may guide the line of transferring the LED 160. Therefore, the groove 515a is provided on the top surface of the planarization layer 515 so that the groove 515a of the planarization layer 515 guides the line of transferring the LED 160 so that the LED 160 is aligned on the planarization layer 515.

[0137] In the stretchable display device 500 according to another exemplary embodiment of the present disclosure, the LED 160 is disposed in the groove 515a of the planarization layer 515 to realize the cavity. When the LED 160 is disposed in the groove 515a of the planarization layer 515, some light emitted from the LED 160 may be reflected by the first connection pad CP1' and the second connection pad CP2' formed of a metal material disposed on the inner side surface of the groove 515a. Therefore, the path of the light emitted from the LED 160 is changed by the first connection pad CP1' and the second connection pad CP2' to be extracted to the forward direction of the stretchable display device 500. Therefore, the LED 160 is disposed in the groove 515a of the planarization layer 515 to extract some light emitted from the LED 160 to the forward direction of the stretchable display device 500 through the first connection pad CP1' and the second connection pad CP2', thereby improving the forward extraction efficiency of the stretchable display device 500.

[0138] <Connecting wire with double structure>

[0139] Figure 6 is a schematic cross-sectional view of a sub-pixel of a stretchable display device according to yet another exemplary embodiment of the present disclosure. Figure 7 is along Figure 6 A cross-sectional view taken along line VII-VII'. Figure 6 and Figure 7 The stretchable display device 600 and Figures 1 to 3 The only difference between the stretchable display devices 100 is the planarization layer 615, the plurality of pads 670 and the plurality of connection lines 680, and the other configurations are substantially the same, so redundant description will be omitted.

[0140] Reference Figure 6 , the plurality of connection lines 680 include a plurality of third connection lines 683. The plurality of third connection lines 683 may be disposed between the plurality of inorganic insulating layers and the organic insulating layer on the plurality of first substrates 111. Specifically, the plurality of third connection lines 683 may be disposed between the interlayer insulating layer 114 of the plurality of inorganic insulating layers and the planarization layer 615. The plurality of third connection lines 683 are connected to the gate pad 671 disposed on the top surface of the interlayer insulating layer 114 to contact the side surface and a portion of the top surface of the interlayer insulating layer 114, the side surface of the gate insulating layer 113, the side surface of the buffer layer 112, and a portion of the top surface of the plurality of first substrates 111.

[0141] Reference Figure 6 , the plurality of third connection lines 683 may extend onto the plurality of second substrates 120. The plurality of third connection lines 683 are disposed on the second substrate 120 extending in the X-axis direction as the first direction to contact the top surface of the second substrate 120 extending in the first direction and the bottom surface of the plurality of first connection lines 681.

[0142] Reference Figure 6 , a planarization layer 615 is disposed on the transistor 150, the plurality of second connection lines 182, and the plurality of third connection lines 683. The planarization layer 615 is disposed between the plurality of first connection lines 681 and the plurality of third connection lines 683 to contact the top surface and the side surface of the plurality of third connection lines 683. In addition, the planarization layer 615 is disposed between the plurality of second connection lines 182 and the plurality of fourth connection lines 684 to contact the top surface and the side surface of the plurality of second connection lines 182. However, the present disclosure is not limited thereto, and the planarization layer 615 may also be disposed to cover only the top surface of the plurality of third connection lines 683 and the top surface of the plurality of second connection lines 182.

[0143] Reference Figure 6, a plurality of first connection lines 681 are disposed on the planarization layer 615. The plurality of first connection lines 681 may be disposed in contact with the top surface and the side surface of the planarization layer 615. In addition, the plurality of first connection lines 681 may be disposed on the plurality of third connection lines 683 on the second substrate 120. That is, the bottom surfaces of the plurality of first connection lines 681 are disposed in contact with a portion of the top surfaces of the plurality of third connection lines 683, so that the plurality of first connection lines 681 and the plurality of third connection lines 683 in contact with each other may transmit the same signal.

[0144] Reference Figure 7 , the plurality of first connection lines 681 may be disposed to surround the plurality of third connection lines 683. For example, the plurality of first connection lines 681 may be disposed to cover the top surface and the side surface of the plurality of third connection lines 683. In this case, the cross-sections of the plurality of first connection lines 681 and the plurality of third connection lines 683 on the plurality of second substrates 120 may be in a trapezoidal shape, but are not limited thereto.

[0145] Refer again Figure 6 , the plurality of connection lines 680 include a plurality of fourth connection lines 684. The plurality of fourth connection lines 684 are disposed in contact with a portion of the side surface and the top surface of the planarization layer 615 to extend onto the plurality of second substrates 120 extending in the Y-axis direction as the second direction. The plurality of fourth connection lines 684 may be disposed on the plurality of second substrates 120 to contact the top surfaces of the plurality of second connection lines 182. That is, the top surfaces of the plurality of second connection lines 182 are disposed in contact with a portion of the bottom surfaces of the plurality of fourth connection lines 684 so that the plurality of second connection lines 182 and the plurality of fourth connection lines 684 in contact with each other may transmit the same signal.

[0146] Meanwhile, the fourth connection lines 684 and the second connection lines 182 may be arranged in the same structure as the first connection lines 681 and the third connection lines 683. That is, the fourth connection lines 684 may be arranged on the second substrates 120 in a manner of surrounding the second connection lines 182, but is not limited thereto.

[0147] In the stretchable display device 600 according to another exemplary embodiment of the present disclosure, a plurality of third connection lines 683 and a plurality of fourth connection lines 684 are arranged to contact a plurality of first connection lines 681 and a plurality of second connection lines 182. By doing so, the resistance of the connection line 680 can be reduced. Therefore, in the stretchable display device 600 according to another exemplary embodiment of the present disclosure, the voltage drop of the signal sent through the connection line 680 can be reduced. For example, the longer the length of the plurality of first connection lines 681 and the plurality of second connection lines 182 is, the greater the resistance is. However, as described above, the plurality of first connection lines 681 and the plurality of second connection lines 182 have a wavy shape similar to the second substrate 120, so that the resistance may be higher than the straight line. Therefore, the voltage (e.g., high potential voltage and low potential voltage) sent by the plurality of first connection lines 681 and the plurality of second connection lines 182 may drop or rise, so that the voltage sent to the sub-pixel SPX may change. As a result, the brightness of each sub-pixel SPX may be irregular. Therefore, in the stretchable display device 600 according to another exemplary embodiment of the present disclosure, the plurality of third connection lines 683 and the plurality of first connection lines 681 and the plurality of fourth connection lines 684 and the plurality of second connection lines 182 are arranged in a parallel structure. By doing so, the resistance generated in the plurality of first connection lines 681 and the plurality of second connection lines 182 can be reduced, and the voltage deviation in each sub-pixel SPX can be reduced, so that the brightness irregularity in each sub-pixel SPX can be reduced.

[0148] In addition, in the stretchable display device 600 according to still another exemplary embodiment of the present disclosure, the plurality of first connection lines 681 may be disposed to surround the plurality of third connection lines 683, and the plurality of fourth connection lines 684 may be disposed to surround the plurality of second connection lines 182. Therefore, during a manufacturing process of the plurality of first connection lines 681 and the plurality of fourth connection lines 684 (for example, during an etching process), loss of the plurality of third connection lines 683 and the plurality of second connection lines 182 may be suppressed.

[0149] <Third connection line set on the step relief layer>

[0150] Figure 8 is a schematic cross-sectional view of a sub-pixel of a stretchable display device according to yet another exemplary embodiment of the present disclosure. Figure 8 The stretchable display device 800 and Figure 6 and Figure 7 The only difference between the stretchable display device 600 is the multiple pads 870, the step relief layer 890 and the multiple connection lines 880, while other configurations are basically the same, so redundant description will be omitted.

[0151] Reference Figure 8, the step relief layer 890 is arranged to cover the top surface and side surface of multiple inorganic insulating layers. That is to say, the step relief layer 890 is arranged to cover multiple inorganic insulating layers. Specifically, the step relief layer 890 can be arranged between multiple first substrates 111 and multiple second connecting lines 882 and between multiple first substrates 111 and multiple third connecting lines 883 to cover the top surface and side surface of the interlayer insulating layer 114, the side surface of the gate insulating layer 113, the side surface of the buffer layer 112, and a portion of the top surface of multiple first substrates 111. Therefore, the step relief layer 890 can be arranged to surround multiple inorganic insulating layers together with multiple first substrates 111. In this case, the slope of the side surface of the step relief layer 890 can be gentler than the slope of the side surface formed by multiple inorganic insulating layers, but is not limited thereto.

[0152] Reference Figure 8 , a plurality of pads 870 are provided on the step relief layer 890. Specifically, among the plurality of pads 870, the gate pad 871 is connected to the plurality of third connection lines 883 on the step relief layer 890 and the data pad 872 may be connected to the plurality of second connection lines 882 on the step relief layer 890. In this case, the gate pad 871 may be formed of the same material as the plurality of third connection lines 883, and the data pad 872 may be formed of the same material as the plurality of second connection lines 882.

[0153] Reference Figure 8 , a plurality of second connection lines 882 and a plurality of third connection lines 883 are disposed on the step relief layer 890. A plurality of second connection lines 882 and a plurality of third connection lines 883 may be disposed on the top surface of the step relief layer 890 to have a flat top surface. Therefore, a plurality of second connection lines 882 and a plurality of third connection lines 883 may be disposed to contact a portion of the top surface and the side surface of the step relief layer 890 on one side and the other side of the step relief layer 890, respectively. A plurality of second connection lines 882 and a plurality of third connection lines 883 may be formed of the same material as the source 153 or the drain 154, but are not limited thereto.

[0154] Reference Figure 8 , a planarization layer 815 is disposed on the transistor 150, the plurality of second connection lines 882, and the plurality of third connection lines 883. The planarization layer 815 is disposed between the plurality of first connection lines 681 and the plurality of third connection lines 883 to contact the top surface and the side surface of the plurality of third connection lines 883. In addition, the planarization layer 815 is disposed between the plurality of second connection lines 882 and the plurality of fourth connection lines 684 to contact the top surface and the side surface of the plurality of second connection lines 882. However, the present disclosure is not limited thereto, and the planarization layer 815 may also be disposed to cover only the top surface of the plurality of third connection lines 883 and the top surface of the plurality of second connection lines 882.

[0155] Reference Figure 8 , a plurality of first connection lines 681 are disposed on the planarization layer 815. The plurality of first connection lines 681 are connected to the gate pad 871 through contact holes formed on the planarization layer 815 to contact a portion of the side surface and the top surface of the planarization layer 815. In addition, the plurality of first connection lines 681 may be disposed on the plurality of third connection lines 883 on the second substrate 120. That is, the bottom surfaces of the plurality of first connection lines 681 may be disposed to contact a portion of the top surfaces of the plurality of third connection lines 883.

[0156] In a stretchable display device 800 according to another exemplary embodiment of the present disclosure, a step relief layer 890 is disposed between a plurality of third connection lines 883 and a plurality of inorganic insulating layers. By doing so, the steps of the side surfaces of the plurality of inorganic insulating layers on which the plurality of third connection lines 883 are disposed can be supplemented. Specifically, the step relief layer 890 can be disposed between the plurality of first substrates 111 and the plurality of third connection lines 883 to cover the top and side surfaces of the plurality of inorganic insulating layers (i.e., the side surfaces of the buffer layer 112, the side surfaces of the gate insulating layer 113, and the side surfaces and a portion of the top surface of the interlayer insulating layer 114). In this case, the side surface of the step relief layer 890 is formed to have a more gentle slope than the slope of the side surface formed by the plurality of inorganic insulating layers, so that the plurality of third connection lines 883 can also be disposed on the step relief layer 890 with a gentle slope. By doing so, the ruptures generated on the plurality of third connection lines 883 when the plurality of third connection lines 883 are formed can be reduced. In addition, the adhesion strength of the plurality of third connection lines 883 is increased, so that the plurality of third connection lines 883 can be suppressed from being broken or separated from the side surface of the step mitigation layer 890. In addition, when the stretchable display device 800 is extended, stress generated in the plurality of third connection lines 883 can be reduced.

[0157] In addition, in a stretchable display device 800 according to another exemplary embodiment of the present disclosure, a step relief layer 890 and a planarization layer 815 are disposed on a plurality of inorganic insulating layers such as a buffer layer 112, a gate insulating layer 113, an interlayer insulating layer 114, and a transistor 150. By doing so, during the transfer process of the LED 160, components disposed below the step relief layer 490 and the planarization layer 415 can be protected. That is, the step relief layer 890 and the planarization layer 815 are disposed on the buffer layer 112, the gate insulating layer 113, the interlayer insulating layer 114, and the transistor 150, so that when the LED 160 is transferred, the stress caused by pressurization can be relieved. Therefore, damage to the transistor 150, various wirings, and connecting lines 880 disposed below the step relief layer 890 and the planarization layer 815 can be reduced.

[0158] <Fifth connecting line>

[0159] Fig. 9 is a schematic cross-sectional view of a sub-pixel of a stretchable display device according to yet another exemplary embodiment of the present disclosure. Fig.10 It is along Fig. 9 A cross-sectional view taken along line XX'. Fig. 9 and Fig.10 The stretchable display device 900 and Figures 1 to 3 The only difference between the stretchable display device 100 is that a sub-substrate 922 is added and a plurality of connecting lines 980 are provided, while other configurations are basically the same, so repeated descriptions are omitted.

[0160] Reference Fig. 9 , the stretchable display device 900 includes a sub-substrate 922. The sub-substrate 922 may be disposed between the lower substrate 110 and both the plurality of first substrates 111 and the plurality of second substrates 920. The sub-substrate 922 may be made of the same material as the plurality of first substrates 111 or the plurality of second substrates 920, but is not limited thereto.

[0161] Reference Fig. 9 , the plurality of connection lines 980 include a plurality of fifth connection lines 985. The plurality of fifth connection lines 985 may be disposed between the sub-substrate 922 and the plurality of second substrates 920. The plurality of fifth connection lines 985 may be made of the same material as the plurality of first connection lines 981 or the plurality of second connection lines 982, but is not limited thereto. Therefore, the plurality of fifth connection lines 985 may be made of a material different from that of the plurality of first connection lines 981 or the plurality of second connection lines 982.

[0162] Reference Fig. 9 and Fig.10 , the plurality of first connection lines 981 are electrically connected to the plurality of fifth connection lines 985. The plurality of first connection lines 981 may be electrically connected to the plurality of fifth connection lines 985 through one or more contact holes formed in the plurality of second substrates 920. As described above, the plurality of second connection lines 982 may also be electrically connected to the plurality of fifth connection lines 985 through one or more contact holes formed in the plurality of second substrates 920. Even in Fig. 9 , it is shown that the plurality of first connection lines 981 and the plurality of second connection lines 982 are connected to the plurality of fifth connection lines 985, but the present disclosure is not limited thereto. Therefore, the plurality of fifth connection lines 985 may be connected to only one connection line 980 of the plurality of first connection lines 981 or the plurality of second connection lines 982.

[0163] In the stretchable display device 900 according to another exemplary embodiment of the present disclosure, a plurality of fifth connection lines 985 are arranged between the sub-substrate 922 and the plurality of second substrates 920. In addition, a plurality of first connection lines 981 and a plurality of second connection lines 982 are arranged to contact the plurality of fifth connection lines 985. By doing so, the resistance of the connection line 980 can be reduced. Therefore, in the stretchable display device 900 according to another exemplary embodiment of the present disclosure, the voltage drop of the signal sent through the connection line 980 can be reduced. For example, the longer the length of the plurality of first connection lines 981 and the plurality of second connection lines 982 is, the greater the resistance is. However, as described above, the plurality of first connection lines 981 and the plurality of second connection lines 982 have a wavy shape similar to the second substrate 920, and therefore the resistance may be higher than the straight line shape. Therefore, the voltage (e.g., high potential voltage and low potential voltage) sent by the plurality of first connection lines 981 and the plurality of second connection lines 982 may drop or rise, so that the voltage sent to the sub-pixel SPX may change. As a result, the brightness of each sub-pixel SPX may be irregular. Therefore, in the stretchable display device 900 according to another exemplary embodiment of the present disclosure, the plurality of first connection lines 981 and the plurality of second connection lines 982 are arranged to contact the plurality of fifth connection lines 985 arranged between the sub-substrate 922 and the plurality of second substrates 920. By doing so, the resistance generated in the plurality of first connection lines 981 and the plurality of second connection lines 982 can be reduced, and the voltage deviation in each sub-pixel SPX can be reduced, so that the brightness irregularity in each sub-pixel SPX can be reduced.

[0164] Exemplary embodiments of the present disclosure may also be described as follows:

[0165] According to one aspect of the present disclosure, a stretchable display device may include: a lower substrate; a plurality of first substrates, which are arranged on the lower substrate and define a plurality of sub-pixels, a plurality of second substrates, which connect adjacent first substrates among the plurality of first substrates; a plurality of inorganic insulating layers, which are arranged on the plurality of first substrates; an organic insulating layer, which is arranged on the plurality of first substrates in a manner covering the top surface and the side surface of the plurality of inorganic insulating layers; a plurality of first connecting lines, which are arranged on the organic insulating layers on the plurality of first substrates and on a second substrate extending along a first direction among the plurality of second substrates; a plurality of second connecting lines, which are arranged between the plurality of inorganic insulating layers and the organic insulating layers on the plurality of first substrates and on a second substrate extending along a second direction different from the first direction among the plurality of second substrates; and a step relief layer, which is arranged between the plurality of second connecting lines and the plurality of inorganic insulating layers.

[0166] The plurality of first connection lines and the plurality of second connection lines may be formed of different materials.

[0167] The plurality of first connection lines may be disposed on a different layer from the plurality of second connection lines.

[0168] The plurality of first connection lines and the plurality of second connection lines may intersect each other on the plurality of first substrates.

[0169] A plurality of third connection lines are disposed between the plurality of inorganic insulating layers and the organic insulating layers on the plurality of first substrates and may be disposed on the second substrate extending in the first direction to contact bottom surfaces of the plurality of first connection lines.

[0170] The plurality of first connection lines may be disposed to surround top and side surfaces of the plurality of third connection lines.

[0171] The step mitigation layer may be disposed between the plurality of third connection lines and the plurality of inorganic insulating layers.

[0172] The stretchable display device may further include a plurality of fourth connection lines disposed on the organic insulating layer and disposed to contact top surfaces of the plurality of second connection lines on the second substrate extending in the second direction.

[0173] The step mitigation layer may be disposed to cover a portion of side surfaces and top surfaces of the plurality of inorganic insulating layers at ends of the plurality of first substrates.

[0174] The step mitigation layer may be disposed to cover top surfaces of the plurality of inorganic insulating layers.

[0175] The stretchable display device may further include a light emitting diode disposed in a groove on the organic insulating layer, the groove being disposed in a portion of a top surface of the organic insulating layer.

[0176] The stretchable display device may further include: a sub-substrate disposed between the lower substrate and the plurality of first substrates and the plurality of second substrates; and a plurality of fifth connecting lines disposed between the sub-substrate and the plurality of second substrates and electrically connected to the plurality of first connecting lines or the plurality of second connecting lines.

[0177] The step mitigation layer may be formed of the same material as the organic insulating layer.

[0178] The step mitigation layer may be formed of an organic material having stronger adhesion to the plurality of second connection lines than the organic insulating layer.

[0179] According to another aspect of the present disclosure, a stretchable display device may include: a plurality of rigid substrates, which are arranged on a soft substrate and include a plurality of display elements; a plurality of connecting substrates, which connect the plurality of rigid substrates between the plurality of rigid substrates; a plurality of inorganic insulating layers, which are arranged on the plurality of rigid substrates; a step relief layer, which is arranged to cover at least a portion of the plurality of inorganic insulating layers; an organic insulating layer, which is arranged on the step relief layer; a plurality of first connecting lines, which are arranged on the organic insulating layer and on a plurality of connecting substrates arranged along one direction; and a plurality of second connecting lines, which are arranged on a layer different from the plurality of first connecting lines and extend in a direction different from the plurality of first connecting lines.

[0180] The stretchable display device may also include: a plurality of third connecting lines, which are arranged to contact the plurality of first connecting lines; and a plurality of fourth connecting lines, which are arranged to contact the plurality of second connecting lines; wherein the plurality of first connecting lines and the plurality of third connecting lines and the plurality of second connecting lines and the plurality of fourth connecting lines are respectively arranged to have a parallel structure.

[0181] The step mitigation layer may be disposed on the plurality of rigid substrates to surround the plurality of inorganic insulating layers.

[0182] The stretchable display device may further include: a sub-substrate disposed between the soft substrate and the plurality of rigid substrates and the plurality of connecting substrates; and a plurality of fifth connecting lines disposed on a top surface of the soft substrate to be electrically connected to the plurality of first connecting lines or the plurality of second connecting lines.

[0183] The stretchable display device may further include a plurality of conductive elements disposed on the plurality of first substrates, wherein the plurality of second connection lines are disposed to have the same material as at least one of the plurality of conductive elements.

[0184] The step mitigation layer may be formed of an organic material having high adhesion with the plurality of second connection lines.

[0185] Although the exemplary embodiments of the present disclosure have been described in detail with reference to the accompanying drawings, the present disclosure is not limited thereto and may be implemented in many different forms without departing from the technical concept of the present disclosure. Therefore, the exemplary embodiments of the present disclosure are provided for illustrative purposes only and are not intended to limit the technical concept of the present disclosure. The scope of the technical concept of the present disclosure is not limited thereto. Therefore, it should be understood that the above exemplary embodiments are exemplary in all aspects and do not limit the present disclosure. The scope of protection of the present disclosure should be interpreted based on the attached claims, and all technical concepts within their equivalent scope should be interpreted as falling within the scope of the present disclosure.

[0186] CROSS-REFERENCE TO RELATED APPLICATIONS

[0187] This application claims the priority of Korean Patent Application No. 10-2019-0132943 filed on October 24, 2019 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.

Claims

1. A stretchable display device, comprising: a lower substrate in which a display area including a plurality of pixels and a non-display area surrounding the display area are defined; a plurality of first substrates, the plurality of first substrates being disposed on the display area of ​​the lower substrate and defining a plurality of sub-pixels, a plurality of second substrates, the plurality of second substrates connecting adjacent first substrates among the plurality of first substrates and being disposed between the plurality of first substrates; a plurality of inorganic insulating layers, wherein the plurality of inorganic insulating layers are disposed on the plurality of first substrates; an organic insulating layer, the organic insulating layer being disposed on the plurality of first substrates in a manner of covering top surfaces and side surfaces of the plurality of inorganic insulating layers; a plurality of first connection lines, wherein the plurality of first connection lines are continuously disposed on the organic insulating layer on the plurality of first substrates and on a second substrate extending along a first direction among the plurality of second substrates; a plurality of second connection lines, the plurality of second connection lines being continuously disposed between the plurality of inorganic insulating layers and the organic insulating layer on the plurality of first substrates and on a second substrate extending in a second direction different from the first direction among the plurality of second substrates; as well as A step relief layer is provided between the plurality of second connection lines and the plurality of inorganic insulating layers.

2. The stretchable display device according to claim 1, wherein: The plurality of first connection lines and the plurality of second connection lines are made of different materials.

3. The stretchable display device according to claim 1, wherein: The plurality of first connection lines are disposed on a different layer from the plurality of second connection lines.

4. The stretchable display device according to claim 1, wherein: The plurality of first connection lines and the plurality of second connection lines intersect each other on the plurality of first substrates.

5. The stretchable display device according to claim 1, further comprising: A plurality of third connection lines are disposed between the plurality of inorganic insulating layers and the organic insulating layer on the plurality of first substrates and on the second substrate extending along the first direction to contact bottom surfaces of the plurality of first connection lines.

6. The stretchable display device according to claim 5, wherein: The plurality of first connection lines are disposed to surround top and side surfaces of the plurality of third connection lines.

7. The stretchable display device according to claim 5, wherein: The step mitigation layer is disposed between the plurality of third connection lines and the plurality of inorganic insulating layers.

8. The stretchable display device according to claim 1, further comprising: A plurality of fourth connection lines are disposed on the organic insulating layer and are disposed to contact top surfaces of the plurality of second connection lines on the second substrate extending along the second direction.

9. The stretchable display device according to claim 1, wherein: The step mitigation layer is disposed to cover a portion of the side surfaces and the top surface of the plurality of inorganic insulating layers at ends of the plurality of first substrates.

10. The stretchable display device according to claim 9, wherein: The step mitigation layer is disposed to cover the top surfaces of the plurality of inorganic insulating layers.

11. The stretchable display device according to claim 9, further comprising: A light emitting diode is disposed in a groove disposed in a portion of a top surface of the organic insulating layer.

12. The stretchable display device according to claim 1, further comprising: a sub-substrate, the sub-substrate being disposed between the plurality of first substrates and the plurality of second substrates and the lower substrate; as well as A plurality of fifth connection lines are disposed between the sub-substrate and the plurality of second substrates and are electrically connected to the plurality of first connection lines or the plurality of second connection lines.

13. The stretchable display device according to claim 1, wherein: The step mitigation layer is made of the same material as the organic insulating layer.

14. The stretchable display device according to claim 1, wherein: The step mitigation layer is formed of an organic material having stronger adhesion to the plurality of second connection lines than the organic insulating layer.

15. A stretchable display device, comprising: A soft substrate, the soft substrate comprising a display area and a non-display area surrounding the display area; a plurality of rigid substrates, the plurality of rigid substrates being disposed on the soft substrate and comprising a plurality of display elements; a plurality of connection substrates, wherein the plurality of connection substrates connect the plurality of rigid substrates between the plurality of rigid substrates; a plurality of inorganic insulating layers, wherein the plurality of inorganic insulating layers are disposed on the plurality of rigid substrates; a step mitigation layer, the step mitigation layer being configured to cover at least a portion of the plurality of inorganic insulating layers; an organic insulating layer, wherein the organic insulating layer is disposed on the step relief layer; a plurality of first connection lines, the plurality of first connection lines being continuously disposed on the organic insulating layer and on the plurality of connection substrates arranged along one direction; as well as A plurality of second connection lines are disposed on a different layer from the plurality of first connection lines and continuously extend in a different direction from the plurality of first connection lines.

16. The stretchable display device according to claim 15, further comprising: a plurality of third connection lines, wherein the plurality of third connection lines are arranged to contact the plurality of first connection lines; as well as a plurality of fourth connection lines, wherein the plurality of fourth connection lines are arranged to contact the plurality of second connection lines; The plurality of first connection lines and the plurality of third connection lines as well as the plurality of second connection lines and the plurality of fourth connection lines are respectively arranged to have a parallel structure.

17. The stretchable display device according to claim 15, wherein: The step mitigation layer is disposed on the plurality of rigid substrates to surround the plurality of inorganic insulating layers.

18. The stretchable display device according to claim 15, further comprising: A sub-substrate, the sub-substrate being disposed between the plurality of rigid substrates and the plurality of connection substrates and the flexible substrate; as well as A plurality of fifth connection lines are disposed on a top surface of the flexible substrate to be electrically connected to the plurality of first connection lines or the plurality of second connection lines.

19. The stretchable display device according to claim 15, further comprising: a plurality of conductive elements, the plurality of conductive elements being disposed on the plurality of rigid substrates, The second connection lines are configured to have the same material as at least one of the conductive elements.

20. The stretchable display device according to claim 15, wherein: The step mitigation layer is formed of an organic material having high adhesion to the plurality of second connection lines.

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