Stretchable display device and method for manufacturing the same

Abstract

A stretchable display device according to one embodiment of the present invention may include a lower substrate, a plurality of first substrates disposed on the lower substrate and having subpixels defined therein, a plurality of second substrates connecting adjacent first substrates among the plurality of first substrates, a plurality of inorganic insulating layers disposed on the plurality of first substrates, an organic insulating layer disposed on the plurality of first substrates to cover the upper surface and side surface of the plurality of inorganic insulating layers, and a plurality of connecting wires disposed on the organic insulating layer and the plurality of second substrates.

Description

Technology Field

[0001] The present invention relates to a stretchable display device and a method for manufacturing a stretchable display device, and more specifically, to a stretchable display device and a method for manufacturing a stretchable display device with improved reliability by reducing disconnection of connecting wires. Background Technology

[0002] Display devices used in computer monitors, TVs, mobile phones, etc., include Organic Light Emitting Displays (OLEDs) that emit light on their own, and Liquid Crystal Displays (LCDs) that require a separate light source.

[0003] The application range of display devices is expanding to include not only computer monitors and TVs but also personal portable devices, and research is underway on display devices that have a large display area while possessing reduced volume and weight.

[0004] In addition, recently, stretchable display devices, which are manufactured by forming a display area, wiring, etc. on a flexible substrate such as a flexible material like plastic so that they can be stretched in a specific direction and changed into various shapes, are attracting attention as next-generation display devices. The problem to be solved

[0005] The problem to be solved by the present invention is to provide a stretchable display device and a method for manufacturing a stretchable display device that can minimize the peeling of connecting wires when the stretchable display device is stretched.

[0006] Another problem that the present invention aims to solve is to provide a stretchable display device and a method for manufacturing a stretchable display device that can minimize the phenomenon of the connecting wires peeling off during repeated stretching of the stretchable display device by mitigating the step difference of the insulating layer that the connecting wires come into contact with.

[0007] Another problem that the present invention aims to solve is to provide a stretchable display device and a method for manufacturing a stretchable display device that can prevent connection wiring from breaking by filling undercut portions that may occur on a substrate during the manufacturing process with a planarization layer.

[0008] Another problem that the present invention aims to solve is to provide a stretchable display device and a method for manufacturing a stretchable display device that can minimize damage to thin-film transistors, capacitors, and connecting wiring disposed on a substrate.

[0009] Another problem that the present invention aims to solve is to provide a stretchable display device and a method for manufacturing a stretchable display device that can secure the area of ​​the first substrate by placing a contact point of a connecting wire on a protrusion of the first substrate.

[0010] Another problem that the present invention aims to solve is to provide a stretchable display device and a method for manufacturing a stretchable display device in which an inorganic material or a metal material can be stably deposited on a first substrate by performing patterning of an inorganic material in several steps.

[0011] The problems of the present invention are not limited to those mentioned above, and other unmentioned problems will be clearly understood by those skilled in the art from the description below. means of solving the problem

[0012] In order to solve the problem described above, a stretchable display device according to one embodiment of the present invention may include a lower substrate, a plurality of first substrates disposed on the lower substrate and having subpixels defined therein, a plurality of second substrates connecting adjacent first substrates among the plurality of first substrates, a plurality of inorganic insulating layers disposed on the plurality of first substrates, an organic insulating layer disposed on the plurality of first substrates to cover the upper surface and side surface of the plurality of inorganic insulating layers, and a plurality of connecting wires disposed on the organic insulating layer and the plurality of second substrates.

[0013] A stretchable display device according to another embodiment of the present invention comprises a plurality of rigid substrates disposed on a flexible substrate and having a plurality of display elements disposed thereon, a plurality of connecting substrates connecting the plurality of rigid substrates between the plurality of rigid substrates, a plurality of inorganic insulating layers disposed on the plurality of rigid substrates, an organic insulating layer surrounding the plurality of inorganic insulating layers together with the plurality of rigid substrates, and a plurality of connecting wires disposed to be in contact with the surface of the organic insulating layer, wherein the angle of inclination of the side of the organic insulating layer may be smaller than the angle of inclination of the side of the plurality of inorganic insulating layers.

[0014] A method for manufacturing a stretchable display device according to another embodiment of the present invention may include the steps of: forming a temporary substrate having a plurality of rigid regions and flexible regions defined on an auxiliary substrate; forming a first inorganic insulating material on the temporary substrate; forming a second inorganic insulating material on the first inorganic insulating material; removing the second inorganic insulating material disposed in the flexible region to form a second inorganic insulating layer; forming a third inorganic insulating material on the first inorganic insulating material and the second inorganic insulating layer; removing the first inorganic insulating material and the third inorganic insulating material disposed in the flexible region to expose the flexible region to form a first inorganic insulating layer and a third inorganic insulating layer; forming an organic insulating layer to cover the upper surface and side surface of the third inorganic insulating layer; forming a plurality of connecting wires connecting adjacent rigid regions among a plurality of rigid regions on the organic insulating layer and the temporary substrate; and removing the temporary substrate disposed in a region other than the region where the plurality of connecting wires are disposed among the flexible regions to form a plurality of first substrates in a plurality of rigid regions and a plurality of second substrates in a flexible region.

[0015] Specific details of other embodiments are included in the detailed description and drawings. Effects of the invention

[0016] The present invention has the effect of reducing the peeling of connecting wires during repeated stretching of a stretchable display device.

[0017] The present invention has the effect of reducing damage to the connecting wiring caused by stress during stretching of a stretchable display device.

[0018] The present invention has the effect of increasing the area for arranging circuits for driving pixels.

[0019] The present invention has the effect of reducing peeling or breakage of an inorganic or metallic material disposed on a first substrate.

[0020] The effects according to the present invention are not limited to those exemplified above, and a wider variety of effects are included within the present invention. Brief explanation of the drawing

[0021] FIG. 1 is an exploded perspective view of a stretchable display device according to one embodiment of the present invention. FIG. 2 is an enlarged plan view of a stretchable display device according to one embodiment of the present invention. Figure 3 is a schematic cross-sectional view of one subpixel of Figure 2. FIG. 4a is an enlarged cross-sectional view of a stretchable display device according to another embodiment of the present invention. FIG. 4b is an image of a stretchable display device according to a comparative example. FIG. 5 is a schematic cross-sectional view of one subpixel of a stretchable display device according to another embodiment of the present invention. FIG. 6 is a schematic cross-sectional view of one subpixel of a stretchable display device according to another embodiment of the present invention. FIG. 7 is an enlarged plan view of a stretchable display device according to another embodiment of the present invention. FIG. 8 is a schematic cross-sectional view of one subpixel of a stretchable display device according to another embodiment of the present invention. FIG. 9 is a schematic cross-sectional view of one subpixel of a stretchable display device according to another embodiment of the present invention. FIG. 10 is a schematic perspective view of one subpixel of a stretchable display device according to another embodiment of the present invention. FIG. 11 is a schematic cross-sectional view according to XI-XI' of FIG. 1 of another embodiment of the present invention. FIGS. 12a to 12m are process diagrams for explaining the manufacturing process of the stretchable display device of FIG. 11. FIG. 13 is a schematic cross-sectional view of one subpixel of a stretchable display device according to another embodiment of the present invention. Specific details for implementing the invention

[0022] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims.

[0023] Shapes, areas, ratios, angles, numbers, etc. disclosed in the drawings for explaining embodiments of the present invention are exemplary, and therefore the present invention is not limited to the depicted details. Throughout the specification, the same reference numerals refer to the same components. Furthermore, in describing the present invention, if it is determined that a detailed description of related prior art may unnecessarily obscure the essence of the present invention, such detailed description is omitted. Where terms such as "includes," "has," or "is made up" are used in the present invention, other parts may be added unless "only" is used. When a component is expressed in the singular, it includes cases where it is included in the plural unless specifically stated otherwise.

[0024] In interpreting the components, they are interpreted to include a margin of error even in the absence of a separate explicit statement.

[0025] In the case of describing a positional relationship, for example, when the positional relationship between two parts is described using expressions such as 'on,' 'upper,' 'lower,' or 'next to,' one or more other parts may be located between the two parts unless 'immediately' or 'directly' is used.

[0026] When an element or layer is referred to as "on" another element or layer, it includes cases where another layer or element is placed directly on top of or in between.

[0027] Additionally, terms such as first, second, etc. are used to describe various components, but these components are not limited by these terms. These terms are used merely to distinguish one component from another. Accordingly, the first component mentioned below may be the second component within the technical scope of the present invention.

[0028] Throughout the specification, the same reference numerals refer to the same components.

[0029] The area and thickness of each component shown in the drawings are illustrated for convenience of explanation, and the present invention is not necessarily limited to the area and thickness of the illustrated components.

[0030] The features of each of the various embodiments of the present invention may be combined or combined with one another, either partially or wholly, and may technically enable various interlocking and operation. Each embodiment may be implemented independently of one another or may be implemented together in an associated relationship.

[0031] Various embodiments of the present invention will be described in detail below with reference to the attached drawings.

[0032] A stretchable display device can be referred to as a display device capable of displaying images even when bent or stretched. A stretchable display device can have high flexibility compared to conventional general display devices. Accordingly, the shape of the stretchable display device can be freely changed according to user operations, such as bending or stretching the stretchable display device. For example, if a user grasps and pulls the end of the stretchable display device, the stretchable display device can be stretched by the user's force. Alternatively, if a user places the stretchable display device on an uneven wall surface, the stretchable display device can be positioned to bend along the shape of the wall surface. Furthermore, when the force applied by the user is removed, the stretchable display device can return to its original shape.

[0033] FIG. 1 is an exploded perspective view of a display device according to one embodiment of the present invention. Referring to FIG. 1, a 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 COF (130) (Chip on Film), a printed circuit board (140), and an upper substrate (US).

[0034] The lower substrate (110) is a substrate for supporting and protecting various components of the stretchable display device (100). The lower substrate (110) may be composed of an insulating material that can be bent or stretched as a flexible substrate. For example, the lower substrate (110) may be made of an elastomer such as silicone rubber, polyurethane (PU), or PTFE (polytetrafluoroethylene), such as polymetalsiloxane (polydimethylsiloxane; PDMS), and thus may have flexible properties. However, the material of the lower substrate (110) is not limited thereto.

[0035] The lower substrate (110) is a flexible substrate and can reversibly expand and contract. Additionally, the elastic modulus may be several MPa to several hundred MPa, and the elongation failure rate may be 100% or more. Here, the elongation failure rate refers to the elongation rate at the point when the stretched object is destroyed or cracked. The thickness of the lower substrate may be 10 µm to 1 mm, but is not limited thereto.

[0036] The lower substrate (110) may have a display area (AA) and a non-display area (NA) surrounding the display area (AA).

[0037] A display area (AA) is an area in a stretchable display device (100) where an image is displayed, and various driving elements for driving the display elements are arranged therein. The display area (AA) includes a plurality of pixels, each including a plurality of subpixels. The plurality of pixels are arranged in the display area (AA) and include a plurality of display elements. Each of the plurality of subpixels can be connected to various wiring. For example, each of the plurality of subpixels can be connected to various wiring such as gate wiring, data wiring, high potential power wiring, low potential power wiring, reference voltage wiring, etc.

[0038] The non-display area (NA) is an area adjacent to the display area (AA). The non-display area (NA) is an area adjacent to the display area (AA) that surrounds the display area (AA). The non-display area (NA) is an area where an image is not displayed, and wiring and circuits may be formed therein. For example, a plurality of pads may be placed in the non-display area (NA), and each pad may be connected to each of a plurality of subpixels of the display area (AA).

[0039] A plurality of first substrates (111) and a plurality of third substrates (121) are disposed on the lower substrate (110). A plurality of first substrates (111) may be disposed in the display area (AA) of the lower substrate (110), and a plurality of third substrates (121) may be disposed in the non-display area (NA) of the lower substrate (110). In FIG. 1, a plurality of third substrates (121) are shown disposed in the non-display area (NA) on the upper and left sides of the display area (AA), but are not limited thereto and may be disposed in any area of ​​the non-display area (NA).

[0040] A plurality of first substrates (111) and a plurality of third substrates (121) are rigid substrates and are spaced apart from each other and independently disposed on a lower substrate (110). The plurality of first substrates (111) and a plurality of third substrates (121) may be rigid compared to the lower substrate (110). That is, the lower substrate (110) may have more flexible characteristics than the plurality of first substrates (111) and a plurality of third substrates (121), and the plurality of first substrates (111) and a plurality of third substrates (121) may have more rigid characteristics than the lower substrate (110).

[0041] The plurality of rigid substrates, the plurality of first substrates (111) and the plurality of third substrates (121), may be made of a plastic material having flexibility, for example, polyimide (PI), polyacrylate, polyacetate, etc. At this time, the plurality of first substrates (111) and the plurality of third substrates (121) may be made of the same material, but are not limited thereto and may be made of different materials.

[0042] The modulus of the plurality of first substrates (111) and the plurality of third substrates (121) may be higher than the modulus of the lower substrate (110). Modulus is an elastic modulus representing the ratio of deformation caused by stress to the stress applied to the substrate, and if the modulus is relatively high, the hardness may be relatively high. Accordingly, 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). The modulus of the plurality of first substrates (111) and the plurality of third substrates (121) may be 1,000 times greater than the modulus of the lower substrate (110), but is not limited thereto.

[0043] In some 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 placed in an area overlapping with a plurality of first substrates (111) and a plurality of third substrates (121) of the lower substrate (110), and the second lower pattern may be placed in an area excluding the area where the plurality of first substrates (111) and a plurality of third substrates (121) are placed, or may be placed in the entire area of ​​the stretchable display device (100).

[0044] At this time, the modulus of the plurality of first lower patterns may be greater than the modulus of the second lower pattern. For example, the plurality of first lower patterns may be made of the same material as the plurality of first substrates (111), and the second lower pattern may be made of a material having a smaller modulus than the plurality of first substrates (111).

[0045] COF (130) is a film having various components placed on a flexible base film (131), and is a component for supplying signals to multiple subpixels of a display area (AA). COF (130) can be bonded to multiple pads of multiple third substrates (121) placed in a non-display area (NA), and supplies power voltage, data voltage, gate voltage, etc., to each of the multiple subpixels of the display area (AA) through the pads. COF (130) includes a base film (131) and a driving IC (132), and various other components may be placed therein.

[0046] The base film (131) is a layer that supports the driving IC (132) of the COF (130). The base film (131) may be made of an insulating material, for example, an insulating material having flexibility.

[0047] The driving IC (132) is a component that processes data for displaying an image and a driving signal for processing it. In FIG. 1, the driving IC (132) is shown mounted in the COF (130) manner, but it is not limited thereto, and the driving IC (132) may be mounted in the COG (Chip On Glass), TCP (Tape Carrier Package), etc.

[0048] In FIG. 1, a third substrate (121) is shown placed in a non-display area (AA) above the display area (AA) to correspond to a first substrate (111) in a single row placed in the display area (AA), and a COF (130) is shown placed on the third substrate (121), but is not limited thereto. That is, a third substrate (121) and a COF (130) may be placed to correspond to a plurality of first substrates (111).

[0049] A control unit, such as an IC chip or a circuit unit, may be mounted on the printed circuit board (140). Additionally, a memory or a processor may also be mounted on the printed circuit board (140). The printed circuit board (140) is configured to transmit a signal for driving a display element from the control unit to the display element. Although three printed circuit boards (140) are described as being used in FIG. 1, the number of printed circuit boards (140) is not limited thereto.

[0050] Hereinafter, for a more detailed description of a stretchable display device (100) according to one embodiment of the present invention, reference is made to FIGS. 2 and FIGS. 3.

[0051] FIG. 2 is an enlarged plan view of a stretchable display device according to one embodiment of the present invention. FIG. 3 is a schematic cross-sectional view of one subpixel of FIG. 2. For convenience of explanation, FIG. 1 is referenced together with FIG. 1.

[0052] Referring to FIGS. 1 and 2, a plurality of first substrates (111) are disposed on a lower substrate (110) in a display area (AA). The plurality of first substrates (111) are spaced apart from each other and disposed on the lower substrate (110). For example, the plurality of first substrates (111) may be disposed in a matrix form on the lower substrate (110) as shown in FIGS. 1 and 2, but are not limited thereto.

[0053] Referring to FIGS. 1 and 2, a plurality of sub-pixels (SPX) constituting a plurality of pixels (PX) may be arranged on a plurality of first substrates (111), and a gate driver (GD) may be mounted on a third substrate (121) located to the left of a display area (AA) among a plurality of third substrates (121). The gate driver (GD) may be formed on the third substrate (121) in a Gate In Panel (GIP) manner when manufacturing various components on the first substrate (111). Accordingly, various circuit configurations constituting the gate driver (GD), such as various transistors, capacitors, and wiring, may be arranged on the plurality of third substrates (121). However, the gate driver (GD) may be mounted in a Chip on Film (COF) manner, not limited thereto. Additionally, a plurality of third substrates (121) are also placed in a non-display area (NA) located to the right of the display area (AA), and a gate driver (GD) can be mounted on a plurality of third substrates (121) located to the right of the display area (AA).

[0054] Referring to FIG. 1, the size of a plurality of third substrates (121) may be larger than the size of a 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, a gate driver (GD) is disposed on each of the plurality of third substrates (121), and for example, a stage of the gate driver (GD) may be disposed on each of the plurality of third substrates (121). Accordingly, since the area occupied by the various circuit configurations constituting a stage of the gate driver (GD) is relatively larger than the area of ​​the first substrate (111) on which the pixel (PX) is disposed, 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).

[0055] Referring to FIGS. 1 and 2, a plurality of second substrates (120) are arranged between a plurality of first substrates (111), between a plurality of third substrates (121), or between a plurality of first substrates (111) and a plurality of third substrates (121). The plurality of second substrates (120) may be referred to as connecting substrates, such as substrates connecting adjacent first substrates (111), adjacent third substrates (121), or the first substrate (111) and the third substrate (121). The plurality of second substrates (120) may be simultaneously formed integrally with the same material as the first substrate (111) or the third substrate (121), but are not limited thereto.

[0056] Referring to FIG. 2, a plurality of second substrates (120) have a curved shape. For example, as shown in FIG. 2, a plurality of second substrates (120) may have a sinusoidal shape. However, the shape of the plurality of second substrates (120) is not limited thereto, and for example, the plurality of second substrates (120) may have various shapes, such as being extended in a zigzag shape or having a plurality of rhombus-shaped substrates connected at vertices and extended. In addition, the number and shape of the plurality of second substrates (120) shown in FIG. 2 are exemplary, and the number and shape of the plurality of second substrates (120) may be varied according to the design.

[0057] Referring to FIG. 3, a plurality of inorganic insulating layers are disposed on a 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 are not limited thereto. 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.

[0058] Referring to FIG. 3, a buffer layer (112) is disposed on a plurality of first substrates (111). The buffer layer (112) is formed on the plurality of first substrates (111) to protect various components of the stretchable display device (100) from the penetration of moisture (H2O) and oxygen (O2), etc., from outside 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, an inorganic layer consisting of silicon nitride (SiNx), silicon oxide (SiOx), silicon oxynitride (SiON), etc., may be composed of a single layer or multiple layers. However, the buffer layer (112) may be omitted depending on the structure or characteristics of the stretchable display device (100).

[0059] At this time, the buffer layer (112) may be formed only in the area overlapping with the plurality of first substrates (111) and the plurality of third substrates (121). As described above, since the buffer layer (112) may be made of an inorganic material, it may be easily damaged, such as by cracking, during the process of stretching the stretchable display device (100). Accordingly, the buffer layer (112) may not be formed in the area between the plurality of first substrates (111) and the plurality of third substrates (121), but may be formed only on the upper part of the plurality of first substrates (111) and the plurality of third substrates (121) by patterning it in the shape of the plurality of first substrates (111) and the plurality of third substrates (121). Accordingly, in a stretchable display device (100) according to one embodiment of the present invention, the buffer layer (112) is formed only in the area overlapping with a plurality of first substrates (111) and a plurality of third substrates (121) which are rigid substrates, so that damage to the buffer layer (112) can be prevented even when the stretchable display device (100) is deformed, such as by bending or stretching.

[0060] Referring to FIG. 3, a transistor (150) including a gate electrode (151), an active layer (152), a source electrode (153), and a drain electrode (154) is formed on the buffer layer (112).

[0061] First, referring to FIG. 3, an active layer (152) is disposed on the buffer layer (112). For example, the active layer (152) may be formed of an oxide semiconductor, amorphous silicon (a-Si), polycrystalline silicon (poly-Si), or an organic semiconductor.

[0062] A 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) and the active layer (152), and may be made of an insulating material. For example, the gate insulating layer (113) may be composed of a single layer of inorganic silicon nitride (SiNx) or silicon oxide (SiOx) or a multilayer of silicon nitride (SiNx) or silicon oxide (SiOx), but is not limited thereto.

[0063] A gate electrode (151) is disposed on the buffer layer (112). The gate electrode (151) is disposed to overlap with the active layer (152). The gate electrode (151) may be any one of various metallic materials, for example, molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu), or an alloy of two or more of these, or a multilayer thereof, but is not limited thereto.

[0064] An interlayer insulating layer (114) is disposed on the gate electrode (151). This layer is for insulating the gate electrode (151), the source electrode (153), and the drain electrode (154), and may be made of an inorganic material, just like the buffer layer (112). For example, the interlayer insulating layer (114) may be composed of a single layer of inorganic silicon nitride (SiNx) or silicon oxide (SiOx) or a multilayer of silicon nitride (SiNx) or silicon oxide (SiOx), but is not limited thereto.

[0065] A source electrode (153) and a drain electrode (154) are disposed on the interlayer insulating layer (114) and are in contact with the active layer (152), respectively. The source electrode (153) and the drain electrode (154) are disposed spaced apart from each other on the same layer. The source electrode (153) and the drain electrode (154) can be electrically connected to the active layer (152) in a manner that contacts the active layer (152). The source electrode (153) and the drain electrode (154) may be any one of various metallic materials, for example, molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu), or an alloy of two or more of these, or a multilayer thereof, but are not limited thereto.

[0066] In addition, the gate insulating layer (113) and the interlayer insulating layer (114) may be patterned and formed only in the area overlapping with the plurality of first substrates (111). Since the gate insulating layer (113) and the interlayer insulating layer (114) may also be made of inorganic material, just like the buffer layer (112), they may be easily damaged, such as by cracks, during the process of stretching the stretchable display device (100). Accordingly, the gate insulating layer (113) and the interlayer insulating layer (114) may not be formed in the area between the plurality of first substrates (111), but may be patterned in the shape of the plurality of first substrates (111) and formed only on the upper part of the plurality of first substrates (111).

[0067] In FIG. 3, for convenience of explanation, only the driving transistor among the various transistors that can be included in the stretchable display device (100) is shown, but switching transistors, capacitors, etc. may also be included in the display device. In addition, although the transistor (150) is described in this specification as having a coplanar structure, various transistors such as a staggered structure may also be used.

[0068] Referring to FIG. 3, a plurality of pads (170) are disposed on the interlayer insulating layer (114). Specifically, among the plurality of pads (170), a gate pad (171) is disposed on the interlayer insulating layer (114). The gate pad (171) is a pad for transmitting a gate signal to a plurality of subpixels (SPX). The gate signal can be transmitted from the gate pad (171) to the gate electrode (151) through a gate wiring formed on the first substrate (111). The gate pad (171) may be made of the same material as the source electrode (153) and the drain electrode (154), but is not limited thereto.

[0069] Referring to FIG. 3, a data pad (172) among a plurality of pads (170) is disposed on an interlayer insulating layer (114). The data pad (172) is a pad for transmitting a data signal to a plurality of subpixels (SPX). The data signal can be transmitted from the data pad (172) to a source electrode (153) or a drain electrode (154) through a data wiring formed on a first substrate (111). The data pad (172) may be made of the same material as the source electrode (153) and the drain electrode (154), but is not limited thereto.

[0070] Referring to FIG. 3, a flattening layer (115) is formed on a transistor (150) and an interlayer insulating layer (114). The flattening layer (115) flattens the upper portion of the transistor (150). The flattening layer (115) may be composed of a single layer or multiple layers and may be made of an organic material. Accordingly, the flattening layer (115) may be referred to as an organic insulating layer. For example, the flattening layer (115) may be made of an acrylic-based organic material, but is not limited thereto.

[0071] Referring to FIG. 3, the flattening layer (115) is positioned to cover the upper and side surfaces of the buffer layer (112), gate insulating layer (113), and interlayer insulating layer (114) on a plurality of first substrates (111), thereby surrounding the buffer layer (112), gate insulating layer (113), and interlayer insulating layer (114) together with the plurality of first substrates (111). Specifically, the flattening layer (115) may be positioned to cover the upper and side surfaces of the interlayer insulating layer (112), the side surface of the gate insulating layer (113), the side surface of the buffer layer (114), and a portion of the upper surface of the plurality of first substrates (111). Accordingly, the flattening layer (115) can compensate for the step difference on the side of the buffer layer (112), the gate insulating layer (113), and the interlayer insulating layer (114), and can increase the adhesive strength of the connecting wire (180) placed on the side of the flattening layer (115) and the flattening layer (115).

[0072] Referring to FIG. 3, the angle of inclination (θ2) of the side of the flattening layer (115) may be smaller than the angle of inclination (θ1) formed by the sides of the buffer layer (112), the gate insulating layer (113), and the interlayer insulating layer (114). For example, the side of the flattening layer (115) may have a gentler slope than the slope formed by the side of the interlayer insulating layer (112), the side of the gate insulating layer (113), and the side of the buffer layer (114). Accordingly, the connecting wire (180) positioned in contact with the side of the flattening layer (115) is positioned with a gentle slope, thereby reducing the stress generated in the connecting wire (180) when the stretchable display device (100) is stretched, and suppressing the phenomenon of the connecting wire (180) cracking or peeling off from the side of the flattening layer (115).

[0073] In some embodiments, a passivation layer may be formed between the transistor (150) and the planarization layer (115). That is, a passivation layer covering the transistor (150) may be formed to protect the transistor (150) from the penetration of moisture and oxygen. The passivation layer may be made of an inorganic material and may be a single layer or a multilayer, but is not limited thereto.

[0074] Referring to FIG. 3, a common wiring (CL) is disposed on the gate insulating layer (113). The common wiring (CL) is a wiring that applies a common voltage to a plurality of subpixels (SPX). The common wiring (CL) may be made of the same material as the gate electrode (151) of the transistor (150), but is not limited thereto.

[0075] Referring to FIGS. 2 and 3, the connecting wiring (180) refers to wiring that electrically connects pads on a plurality of first substrates (111) or a plurality of third substrates (121). The connecting wiring (180) is placed on the first substrate (111) and a plurality of second substrates (120).

[0076] The connecting wiring (180) includes a first connecting wiring (181) and a second connecting wiring (182). The first connecting wiring (181) and the second connecting wiring (182) are arranged between a plurality of first substrates (111). Specifically, the first connecting wiring (181) refers to a wiring that extends in the X-axis direction between a plurality of first substrates (111) among the connecting wiring (180), and the second connecting wiring (182) refers to a wiring that extends in the Y-axis direction between a plurality of first substrates (111) among the connecting wiring (180).

[0077] The connecting wire (180) may be made of a metal material such as copper (Cu), aluminum (Al), titanium (Ti), molybdenum (Mo), or a layered structure of a metal material such as copper / molybdenum-titanium (Cu / Moti), titanium / aluminum / titanium (Ti / Al / Ti), but is not limited thereto.

[0078] In the case of a typical organic light-emitting display, various wirings such as multiple gate wirings and multiple data wirings are arranged to extend in a straight line between multiple subpixels, and multiple subpixels are connected to a single signal wiring. Accordingly, in the case of a typical organic light-emitting display, various wirings such as gate wirings, data wirings, high potential power wirings, and reference voltage wirings extend from one side of the organic light-emitting display to the other side without interruption on the substrate.

[0079] In contrast, in the case of a stretchable display device (100) according to one embodiment of the present invention, various wirings such as straight-shaped gate wiring, data wiring, high-potential power wiring, and reference voltage wiring, which can be seen as used in a general organic light-emitting display device, are placed only on a plurality of first substrates (111) and a plurality of third substrates (121). That is, in the stretchable display device (100) according to one embodiment of the present invention, straight-shaped wiring is placed only on a plurality of first substrates (111) and a plurality of third substrates (121).

[0080] In a display device (100) according to one embodiment of the present invention, pads on two adjacent first substrates (111) or two adjacent third substrates (121) may be connected by a connecting wire (180) to connect discontinuous wiring on a first substrate (111) or a third substrate (121). That is, the connecting wire (180) electrically connects two adjacent first substrates (111), two adjacent third substrates (121), and pads on the first substrate (111) and the third substrate (121). Accordingly, a stretchable display device (100) according to one embodiment of the present invention may include a plurality of connecting wires (180) to electrically connect various wirings, such as gate wiring, data wiring, high potential power wiring, reference voltage wiring, etc., between a plurality of first substrates (111), a plurality of third substrates (121), and between a plurality of first substrates (111) and a plurality of third substrates (121). For example, gate wiring may be disposed on a plurality of first substrates (111) arranged adjacently in the X-axis direction, and gate pads (171) may be disposed at both ends of the gate wiring. At this time, each of the plurality of gate pads (171) on the plurality of first substrates (111) arranged adjacently in the X-axis direction may be connected to each other by a first connecting wire (181) that functions as gate wiring. Accordingly, the gate wiring disposed on the plurality of first substrates (111) and the first connecting wire (181) disposed on the third substrate (121) may function as a single gate wiring. In addition, among all the various wirings that may be included in the stretchable display device (100), wiring extending in the X-axis direction, for example, light emission signal wiring, low potential power wiring, and high potential power wiring, may also be electrically connected by the first connecting wire (181) as described above.

[0081] Referring to FIGS. 2 and 3, the first connecting wire (181) can connect two pads on a first substrate (111) that are arranged side by side among a plurality of pads on a first substrate (111) arranged adjacently in the X-axis direction. The first connecting wire (181) can function as a gate wire, a light-emitting signal wire, a high-potential power wire, or a low-potential power wire, but is not limited thereto. For example, the first connecting wire (181) can function as a gate wire and can electrically connect two gate pads (171) on a first substrate (111) arranged side by side in the X-axis direction. Accordingly, as previously described, gate pads (171) on a plurality of first substrates (111) arranged in the X-axis direction can be connected by the first connecting wire (181) that functions as a gate wire, and a single gate signal can be transmitted.

[0082] Referring to FIG. 2, the second connecting wire (182) can connect two pads on a first substrate (111) that are arranged side by side among a plurality of pads on a first substrate (111) arranged adjacently in the Y-axis direction. The second connecting wire (182) can function as a data wire, a high-potential power wire, a low-potential power wire, or a reference voltage wire, but is not limited thereto. For example, the second connecting wire (182) can function as a data wire and can electrically connect data wires (DL) on two first substrates (111) arranged side by side in the Y-axis direction. Accordingly, as previously described, data wires (DL) on a plurality of first substrates (111) arranged in the Y-axis direction can be connected by a plurality of second connecting wires (182) that function as data wires, and a single data signal can be transmitted.

[0083] Referring to FIG. 1, the connecting wiring (180) may further include wiring that connects pads on a plurality of first substrates (111) and a plurality of third substrates (121) to each other, or connects two pads on a third substrate (121) that are arranged side by side among pads on a plurality of third substrates (121) arranged adjacently in the Y-axis direction.

[0084] The first connecting wire (181) may be formed by extending to the upper surface of the second substrate (120) while in contact with the upper and side surfaces of the flattening layer (115) disposed on the first substrate (111). Additionally, the second connecting wire (182) may be formed by extending to the upper surface of the second substrate (120) while in contact with the upper and side surfaces of the flattening layer (115) disposed on the first substrate (111). The arrangement of the first connecting wire (181) and the second connecting wire (182) and the resulting effects will be described in detail later.

[0085] Referring to FIG. 3, a bank (116) is formed on a first connection pad (191), a second connection pad (192), a connection wire (180), and a flattening layer (115). The bank (116) is a component that distinguishes adjacent subpixels (SPX).

[0086] The bank (116) is positioned to cover a portion of the adjacent second connecting wire (182) and the first connecting pad (191), or at least a portion of the first connecting wire (181) and the second connecting pad (192). The bank (116) may be made of an insulating material. Additionally, the bank (116) may be made of a black material. By including the black material, the bank (116) serves to obscure the wires that can be seen through the display area (AA). The bank (116) may be made of, for example, a transparent carbon-based mixture, specifically carbon black. However, it is not limited thereto, and the bank (116) may be made of a transparent insulating material.

[0087] Referring to FIG. 3, an LED (160) is disposed on the first connection pad (191) and the second connection pad (192). 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 display device (100) according to one embodiment of the present invention has a flip-chip structure in which the n-electrode (164) and the p-electrode (165) are formed on one side.

[0088] The n-type layer (161) can be formed by injecting n-type impurities into gallium nitride (GaN) having excellent crystallinity. The n-type layer (161) may also be placed on a separate base substrate made of a material capable of emitting light.

[0089] An active layer (162) is disposed on the n-type layer (161). The active layer (162) is a light-emitting layer that emits light from the LED (160) and may be made of a nitride semiconductor, for example, indium gallium nitride (InGaN). A 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).

[0090] An LED (160) according to one embodiment of the present invention is manufactured by sequentially stacking an n-type layer (161), an active layer (162), and a p-type layer (163) as described above, and then etching a predetermined portion to form an n-electrode (164) and a p-electrode (165). At this time, the predetermined portion is a space to separate the n-electrode (164) and the p-electrode (165), and the predetermined portion is etched so that a part of the n-type layer (161) is exposed. In other words, the surface of the LED (160) on which the n-electrode (164) and the p-electrode (165) are placed may have different height levels rather than being a flattened surface.

[0091] In this way, an n-electrode (164) is placed on the etched area, that is, on the n-type layer (161) exposed by the etching process. The n-electrode (164) may be made of a conductive material. Meanwhile, a p-electrode (165) is placed on the unetched area, that is, on the p-type layer (163). The p-electrode (165) may also be made of a conductive material, for example, the same material as the n-electrode (164).

[0092] An adhesive layer (AD) is disposed between the upper surface of the first connection pad (191) and the second connection pad (192) and the first connection pad (191) and the second connection pad (192), so that an LED (160) can be adhered to the first connection pad (191) and the second connection pad (192). At this time, the n-electrode (164) can be disposed on the second connection pad (192), and the p-electrode (165) can be disposed on the first connection pad (191).

[0093] The adhesive layer (AD) may be a conductive adhesive layer in which conductive balls are dispersed on an insulating base member. Accordingly, when heat or pressure is applied to the adhesive layer (AD), the conductive balls in the area where heat or pressure is applied may be electrically connected to possess conductive properties, while the area where no pressure is applied may possess insulating properties. For example, the n-electrode (164) is electrically connected to the second connecting wire (182) through the adhesive layer (AD), and the p-electrode (165) is electrically connected to the first connecting wire (181) through the adhesive layer (AD). That is, the adhesive layer (AD) can be applied to the first connecting pad (191) and the second connecting pad (192) using a method such as inkjet, then the LED (160) is transferred onto the adhesive layer (AD), and the first connecting pad (191) and the p-electrode (165) and the second connecting pad (192) and the n-electrode (164) can be electrically connected by applying pressure and heat to the LED (160). However, other parts of the adhesive layer (AD), excluding the part of the adhesive layer (AD) disposed between the n-electrode (164) and the second connection pad (192) and the part of the adhesive layer (AD) disposed between the p-electrode (165) and the first connection pad (191), have insulating properties. Meanwhile, the adhesive layer (AD) may be disposed in a separated form on each of the first connection pad (191) and the second connection pad (192).

[0094] In this way, a display device (100) according to one embodiment of the present invention has a structure in which an LED (160) is placed on a lower substrate (110) on which a transistor (150) is placed, so that when the display device (100) is turned on, different voltage levels applied to the first connection pad (191) and the second connection pad (192) are transmitted to the n-electrode (164) and the p-electrode (165), respectively, and the LED (160) emits light.

[0095] Referring to FIG. 3, an upper substrate (US) is placed on a bank (116), an LED (160), and a lower substrate (110).

[0096] The upper substrate (US) is a substrate that supports various components placed below the upper substrate (US). Specifically, the upper substrate (US) can be formed by coating a material constituting the upper substrate (US) onto the lower substrate (110) and the first substrate (111) and then curing it, so as to be placed in contact with the lower substrate (110), the first substrate (111), the second substrate (120), and the connecting wiring (180).

[0097] The upper substrate (US) may be composed of an insulating material that can be bent or stretched as a flexible substrate. As a flexible substrate, the upper substrate (US) may be capable of reversibly expanding and contracting. Additionally, the elastic modulus 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.

[0098] The upper substrate (US) may be made of the same material as the lower substrate (110). For example, the upper substrate (US) may be made of silicone rubber such as polydimethylsiloxane (PDMS), polyurethane (PU), or an elastomer such as PTFE (polytetrafluoroethylene), and thus may have flexible properties. However, the material of the upper substrate (US) is not limited thereto.

[0099] Meanwhile, although not shown in FIG. 3, a polarizing layer may be disposed on the upper substrate (US). The polarizing layer may function to reduce external light reflection by polarizing light incident from outside the stretchable display device (100). Additionally, an optical film other than the polarizing layer may be disposed on the upper substrate (US).

[0100] In conventional stretchable display devices, a planarization layer made of an organic insulating material is placed on a plurality of inorganic insulating layers without covering the sides of the plurality of inorganic insulating layers, such as a buffer layer, a gate insulating layer, and an interlayer insulating layer. Accordingly, connecting wires are arranged to come into contact with the sides of the plurality of inorganic insulating layers. However, when a patterning process, i.e., an etching process, is performed on the plurality of inorganic insulating layers, a step difference may occur on the sides of the plurality of inorganic insulating layers. That is, since the slope of the sides of the plurality of inorganic insulating layers formed by the etching process is very steep, if connecting wires are formed directly on the sides of these plurality of inorganic insulating layers, a disconnection of the connecting wires may occur.

[0101] Accordingly, in a stretchable display device (100) according to one embodiment of the present invention, a flattening layer (115) is arranged to cover the side of a plurality of inorganic insulating layers between a substrate (111) and a flattening layer (115), such as a buffer layer (112), a gate insulating layer (113), and an interlayer insulating layer (114), so as to compensate for the step difference on the side of the buffer layer (112), the gate insulating layer (113), and the interlayer insulating layer (114). That is, the flattening layer (115) is positioned to cover the upper surface and side surface of the buffer layer (112), the gate insulating layer (113), and the interlayer insulating layer (114), and the angle of inclination (θ) of the side surface of the flattening layer (115) may be smaller than the angle of inclination (θ) formed by the sides of the buffer layer (112), the gate insulating layer (113), and the interlayer insulating layer (114). That is, the side surface of the flattening layer (115) may have a gentler slope than the slope formed by the upper surface and side surface of the interlayer insulating layer (112), the side surface of the gate insulating layer (113), and the side surface of the buffer layer (114). Accordingly, the connecting wire (180) positioned in contact with the side surface of the flattening layer (115) is positioned with a gentle slope, so that the occurrence of cracks in the connecting wire (180) during the formation of the connecting wire (180) can be reduced. In addition, when stretching the stretchable display device (100), the connection Stress occurring in the wiring (180) is reduced, and the phenomenon of the connecting wiring (180) cracking or peeling off from the side of the flattening layer (115) can be suppressed.

[0102] Meanwhile, in a stretchable display device (100) according to one embodiment of the present invention, the connecting wire (180) has the same shape as the second substrate (120) and can have a sinusoidal shape. Accordingly, the resistance of the connecting wire (180) may increase compared to the case where the connecting wire (180) has a straight shape. Accordingly, to lower the resistance of the connecting wire (180), copper (Cu), which has low resistance characteristics among various metal materials that can be used as wiring, may be used as the connecting wire (180). However, when copper (Cu) or other low-resistance metal materials are formed on an inorganic insulating layer made of an inorganic insulating material, the adhesion strength with the inorganic insulating layer may be a problem. That is, since copper (Cu) or other low-resistance metal materials have low adhesion strength with the inorganic insulating layer, when the connecting wire (180) is positioned to be in contact with the side of a plurality of inorganic insulating layers such as the buffer layer (112), the gate insulating layer (113), and the interlayer insulating layer (114), when the stretchable display device (100) is stretched, the connecting wire (180) may be peeled off from the side of the buffer layer (112), the gate insulating layer (113), and the interlayer insulating layer (114), and the reliability of the stretchable display device (100) may be reduced.

[0103] Accordingly, in a stretchable display device (100) according to one embodiment of the present invention, a flattening layer (115) is arranged to cover the sides of a buffer layer (112), a gate insulating layer (113), and an interlayer insulating layer (114), thereby reducing the peeling of a connecting wire (180) from the sides of the flattening layer (115) and a plurality of inorganic insulating layers during repeated stretching of the stretchable display device (100). More specifically, a connecting wire (180) made of copper (Cu) or other low-resistance metal materials is arranged on the upper surface and sides of a flattening layer (115) made of an organic insulating material, so that the lower adhesive strength of the connecting wire (180) can be improved. Accordingly, in a stretchable display device (100) according to one embodiment of the present invention, a flattening layer (115) is arranged to cover the sides of a plurality of inorganic insulating layers on a first substrate (111), such as a buffer layer (112), a gate insulating layer (113), and an interlayer insulating layer (114), so that when the stretchable display device (100) is repeatedly stretched, the peeling of the connecting wire (180) from the flattening layer (115) can be reduced, and thus the reliability of the stretchable display device (100) can be improved.

[0104] In addition, in a stretchable display device (100) according to one embodiment of the present invention, a flattening layer (115) is placed on a plurality of inorganic insulating layers, such as a buffer layer (112), a gate insulating layer (113), and an interlayer insulating layer (114), and on a transistor (150), so that components placed below the flattening layer (115) can be protected during the LED (160) transfer process. When placing an LED (160) in the stretchable display device (100), the LED (160) can be placed by applying pressure from the top of the stretchable display device (100). At this time, the transistor (150), various wiring and connecting wiring (180), etc. placed below the LED (160) may be damaged due to the pressure. Accordingly, by placing a flattening layer (115) on the buffer layer (112), gate insulating layer (113), interlayer insulating layer (114), and transistor (150), stress caused by pressure can be buffered when transferring the LED (160), and thus damage to the transistor (150), various wiring and connecting wiring (180), etc. placed below the flattening layer (115) can be reduced.

[0105] FIG. 4a is an enlarged cross-sectional view of a stretchable display device according to another embodiment of the present invention. Compared to the stretchable display device (100) of FIG. 1 to FIG. 3, the stretchable display device (400) of FIG. 4a differs only in the plurality of first substrates (411), plurality of second substrates (420), flattening layer (415), and connecting wiring, and since other configurations are substantially the same, a redundant description is omitted. For convenience of explanation, only area A of FIG. 3 is shown in FIG. 4a. In addition, FIG. 4a shows only the first connecting wiring (481) among the connecting wiring, and the second connecting wiring can also be applied in the same way.

[0106] Referring to FIG. 4a, a plurality of first substrates (411) include a first portion (P1) and a second portion (P2). The first portion (P1) is an area where a plurality of inorganic insulating layers, such as a buffer layer (112), a gate insulating layer (113), and an interlayer insulating layer (114), are disposed, and the second portion (P2) is an area covered by a flattening layer (415). The first portion (P1) may have a first thickness (T1), and the second portion (P2) may have a second thickness (T2) that is smaller than the first thickness (T1) of the first portion (P1). At this time, the first thickness (T1) may be the distance between the upper surface of the plurality of first substrates (411) in contact with the buffer layer (112) and the lower surface in contact with the lower substrate (110).

[0107] Referring to FIG. 4a, a plurality of second substrates (420) are connected to a second portion (P2) of a plurality of first substrates (411), and a first connecting wire (481) may be disposed on the upper surface of the plurality of second substrates (420). At this time, the plurality of second substrates (420) may have the same thickness as the second portion (P2) of the plurality of first substrates (411).

[0108] Referring to FIG. 4a, the first part (P1) adjacent to the second part (P2) may have an undercut shape. Specifically, in the manufacturing process of a stretchable display device (400), in order to place connecting wires on a plurality of second substrates (420), a plurality of inorganic insulating layers, such as a buffer layer (112), a gate insulating layer (113), and an interlayer insulating layer (114), placed on the second part (P2) of a plurality of first substrates (411) and on the plurality of second substrates (420), may be etched and removed. However, when etching the plurality of inorganic insulating layers, a portion of the second part (P2) of the plurality of first substrates (411) and a portion of the upper surface of the plurality of second substrates (420) may be removed together. Accordingly, the first part (P1) adjacent to the second part (P2) may have an undercut shape, that is, a shape in which the cross-sectional area or the width of the cross-section decreases from the top to the bottom, and the thickness of the second part (P2) and the plurality of second substrates (420) may be smaller than the thickness of the first part (P1).

[0109] Referring to FIG. 4a, the flattening layer (415) is placed in the first part (P1) adjacent to the second part (P2) to compensate for the undercut shape of the first part (P1) adjacent to the second part (P2). That is, since the flattening layer (415) can fill the space below the upper surface of the first part (P1), the first connecting wire (481) is not placed on the undercut shape, thereby reducing the breakage of the first connecting wire (481).

[0110] FIG. 4b is an image of a stretchable display device according to a comparative example. In the stretchable display device of FIG. 4b, it is assumed that a plurality of first substrates (11) and a plurality of second substrates (20) are made of polyimide (PI), a plurality of inorganic insulating layers including a buffer layer (11), a gate insulating layer (12), and an interlayer insulating layer (14) are made of silicon nitride (SiNx), and a first connecting wire (81) is made of copper (Cu). Additionally, the thickness of the plurality of first substrates (11) is set to 6 μm, the total thickness of the buffer layer (11), the gate insulating layer (12), and the interlayer insulating layer (14) is set to 3600 Å, and the thickness of the first connecting wire (81) is set to 5000 Å. Additionally, it was assumed that the buffer layer (11), the gate insulating layer (12), and the interlayer insulating layer (14) are disposed on a plurality of first substrates (11), and the first connecting wiring (81) is disposed on a plurality of first substrates (11) and a plurality of second substrates (20).

[0111] Referring to FIG. 4b, a portion of a plurality of first substrates (11) adjacent to a plurality of second substrates (20) and a portion of a plurality of second substrates (20) are etched together during the process of etching the buffer layer (11), the gate insulating layer (12), and the interlayer insulating layer (14), so that a portion of the undercut shape of a plurality of first substrates (11) adjacent to a plurality of second substrates (20) can be seen, and the thickness of the plurality of second substrates (20) is smaller than the thickness of the plurality of first substrates (11).

[0112] Additionally, referring to FIG. 4b, the first connecting wire (81) may be placed in a portion where an undercut is formed on a plurality of first substrates (11). However, when the first connecting wire (81) is placed along the undercut shape of the plurality of first substrates (11), as shown in area B of FIG. 4b, a break in the first connecting wire (81) may occur due to a step difference in the portion where the undercut is formed.

[0113] In a stretchable display device (400) according to another embodiment of the present invention, a flattening layer (415) is arranged to cover a second part (P2) of a plurality of first substrates (411) and a first part (P1) adjacent to the second part (P2), thereby reducing the disconnection of the connecting wire when forming the connecting wire. Specifically, the first part (P1) adjacent to the second part (P2) of a plurality of first substrates (411) may have an undercut shape by being etched together during the process of etching the buffer layer (111), the gate insulating layer (112), and the interlayer insulating layer (114). The flattening layer (415) may be arranged to cover a second part (P2) of a plurality of first substrates (411) and a first part (P1) adjacent to the second part (P2). Accordingly, the flattening layer (415) can compensate for the undercut shape of the first part (P1) adjacent to the second part (P2), and as the connecting wire is placed on the flattening layer (415), the disconnection of the connecting wire during the formation of the connecting wire can be reduced.

[0114] FIG. 5 is a schematic cross-sectional view of one subpixel of a stretchable display device according to another embodiment of the present invention. Compared to the stretchable display device (100) of FIG. 1 to 3, the stretchable display device (500) of FIG. 5 is different only in the flattening layer (515), a plurality of pads (570), and a plurality of connecting wires (580), and other components are substantially the same, so a redundant description is omitted.

[0115] Referring to FIG. 5, a plurality of pads (570) are disposed on the same layer as the gate electrode (151), which is an electrode of the transistor (150). Specifically, the plurality of pads (570) are disposed on the gate insulating layer (113) and can be connected to a connecting wire (580) through a contact hole formed in the interlayer insulating layer (114) and the flattening layer (515). Specifically, among the plurality of pads (570), the gate pad (571) can be connected to the first connecting wire (581), and the data pad (572) can be connected to the second connecting wire (582).

[0116] Referring to FIG. 5, the flattening layer (515) includes a first surface (S1) and a second surface (S2) formed at a lower position than the first surface (S1). A first connection pad (191) and a second connection pad (192) may be disposed on the first surface (S1) of the flattening layer (515), and a first connection wire (581) and a second connection wire (582) may be disposed on the second surface (S2). Accordingly, as the first connection wire (581) and the second connection wire (582) are connected to a plurality of pads (570) at a lower position, the area where the first connection wire (581) and the second connection wire (582) are disposed on the side of the flattening layer (515) may be reduced.

[0117] In a stretchable display device (500) according to another embodiment of the present invention, a plurality of pads (570) are placed on the same layer as the gate electrode (151), thereby lowering the step height at which a plurality of connecting wires (580) are placed. That is, as shown in FIG. 5, when a plurality of pads (570) are placed on the same layer as the gate electrode (151), which is an electrode of the transistor (150), the step height of the placement of the plurality of pads (570) can be lowered, and a first connecting wire (581) and a second connecting wire (582) can be connected to the plurality of pads (570) at a lower position. Accordingly, by placing the first connecting wire (581) and the second connecting wire (582) on the second surface (S2) of the flattening layer (515), a plurality of connecting wires (580) can be connected to the plurality of pads (570) at a lower position than the first surface (S1) of the flattening layer (515). Accordingly, in a stretchable display device (500) according to another embodiment of the present invention, a plurality of pads (570) are placed on the same layer as the gate electrode (151), so that a plurality of connecting wires (580) can be electrically connected to the plurality of pads (570) at a low position, and thus, when the stretchable display device (500) is stretched, the stress generated in the plurality of connecting wires (580) can be reduced, thereby reducing the risk of the plurality of connecting wires (580) being disconnected.

[0118] FIG. 6 is a schematic cross-sectional view of one subpixel of a stretchable display device according to another embodiment of the present invention. The stretchable display device (600) of FIG. 6 is substantially identical to the stretchable display device (100) of FIG. 1 to 3, except that the gate insulating layer (613), interlayer insulating layer (614), flattening layer (615), plurality of pads (670), and plurality of connecting wires (680) are different, and a BSM (618) and an active buffer (619) are added, so a redundant description is omitted.

[0119] Referring to FIG. 6, a Barrier Shield Metal (BSM; 618) is disposed on a buffer layer (112). The BSM (618) may be a metal pattern disposed on a plurality of first substrates (111). The BSM (618) may be disposed to overlap with the active layer (152) of the transistor (150) on the plurality of first substrates (111), and the width of the BSM (618) in cross-section may be greater than or equal to the width of the active layer (152) of the transistor (150). The BSM (618) may be made of various metal materials, and the BSM (618) may be floated or configured to have a constant voltage applied.

[0120] An active buffer (619) is disposed on the BSM (618) to insulate the active layer (152) of the BSM (618) and the transistor (150). The active buffer (619) may be formed of the same material as the plurality of first substrates (111). For example, the active buffer (619) may be composed of a single layer of silicon nitride (SiNx) or silicon oxide (SiOx) or a multilayer of silicon nitride (SiNx) and silicon oxide (SiOx).

[0121] Referring to FIG. 6, a plurality of pads (670) are placed on the same layer as the BSM (618). That is, all of the plurality of pads (670) are placed on the buffer layer (112) and can be spaced apart from the BSM (618). For example, among the plurality of pads (670), the gate pad (671) is placed on the right side of the BSM (618) and is connected to the first connection wire (681) through a contact hole formed in the active buffer (619), the gate insulating layer (613), the interlayer insulating layer (614), and the flattening layer (615), and the data pad (672) is placed on the left side of the BSM (618) and is connected to the second connection wire (682) through a contact hole formed in the active buffer (619), the gate insulating layer (613), the interlayer insulating layer (614), and the flattening layer (615). Multiple pads (670) may be made of the same material as BSM (618), but are not limited thereto.

[0122] Referring to FIG. 6, the flattening layer (615) includes a first surface (S1) and a second surface (S2) formed at a lower position than the first surface (S1). A first connection pad (191) and a second connection pad (192) may be disposed on the first surface (S1) of the flattening layer (615), and a first connection wire (681) and a second connection wire (682) may be disposed on the second surface (S2). Accordingly, as the first connection wire (681) and the second connection wire (682) are connected to a plurality of pads (670) at a lower position, the area where the first connection wire (681) and the second connection wire (682) are disposed on the side of the flattening layer (615) may be reduced.

[0123] A stretchable display device (600) according to another embodiment of the present invention may further include a floating BSM (618). Accordingly, hydrogen or moisture is blocked by the BSM (618), the laser irradiated during the laser release process is also blocked, and the shift phenomenon of the threshold voltage (Vth) of the transistor (150) that may occur as the potential of the surface of the lower substrate (110) increases can also be suppressed.

[0124] In a stretchable display device (600) according to another embodiment of the present invention, a plurality of pads (670) are placed on the same layer as the BSM (618) to lower the step height at which a plurality of connecting wires (680) are placed. That is, as shown in FIG. 6, when a plurality of pads (670) are placed on the same layer as the BSM (618), the step height of the placement of the plurality of pads (670) can be lowered, and a first connecting wire (681) and a second connecting wire (682) can be connected to the plurality of pads (670) at a lower position. Accordingly, by placing the first connecting wire (681) and the second connecting wire (682) on the second surface (S2) of the flattening layer (615), a plurality of connecting wires (680) can be connected to the plurality of pads (670) at a lower position than the first surface (S1) of the flattening layer (615). Accordingly, in a stretchable display device (600) according to another embodiment of the present invention, a plurality of pads (670) are placed on the same layer as the BSM (618), so that a plurality of connecting wires (680) can be electrically connected to the plurality of pads (670) at a low position, and thus, when the stretchable display device (600) is stretched, the stress generated in the plurality of connecting wires (680) can be reduced, thereby reducing the risk of the plurality of connecting wires (680) being disconnected.

[0125] FIG. 7 is an enlarged plan view of a stretchable display device according to another embodiment of the present invention. FIG. 8 is a schematic cross-sectional view of one subpixel of a stretchable display device according to another embodiment of the present invention. Compared to the stretchable display device (100) of FIG. 1 to FIG. 3, the stretchable display device (700) of FIG. 7 and FIG. 8 differs only in the plurality of first substrates (711), plurality of connecting wires (780), and plurality of pads (770), and other configurations are substantially the same, so a redundant description is omitted.

[0126] Referring to FIG. 7, a plurality of first substrates (711) include a central portion (711a) and a plurality of protrusions (711b) protruding from the central portion (711a). The central portion (711a) is an area where subpixels (SPX) are placed, and the plurality of protrusions (711b) are areas where contact holes (CNT) are placed. One of the plurality of contact holes (CNT) may be placed in each of the plurality of protrusions (711b). In FIG. 7, the plurality of protrusions (711b) are shown as being placed four times along one side of the central portion (711a), but this is not limited thereto, and the number of the plurality of protrusions (711b) can be varied according to the design.

[0127] Referring to FIG. 7, the width of the plurality of protrusions (711b) may decrease as it moves away from the central portion (711a). Specifically, the width of the plurality of protrusions (711b) may be largest in the portion adjacent to the central portion (711a) and smallest in the portion connected to the plurality of second substrates (120). At this time, the width of the plurality of protrusions (711b) in the portion connected to the plurality of second substrates (120) may be equal to the width of the plurality of second substrates (120). Accordingly, when the stretchable display device (700) is stretched, the stress generated in the plurality of protrusions (711b) is distributed, thereby improving the stretching stability of the stretchable display device (700).

[0128] Referring to FIG. 8, a plurality of pads (770) are arranged to be in contact with a buffer layer (112), a gate insulating layer (113), an interlayer insulating layer (114), and a plurality of first substrates (711). Specifically, the plurality of pads (770) may be arranged to be in contact with the upper surface of the interlayer insulating layer (114), the side surface of the buffer layer (112), the gate insulating layer (113), and the interlayer insulating layer (114), and the upper surface of a plurality of first substrates (711). As the plurality of pads (770) are arranged to be in contact with a portion of the upper surface of a plurality of first substrates (711), a plurality of connecting wires (780) may be connected to the plurality of pads (770) at a lower position.

[0129] Referring to FIG. 8, the flattening layer (715) is arranged to cover a plurality of pads (770) and a plurality of first substrates (711). The flattening layer (715) may be arranged to cover the upper and side surfaces of the plurality of pads (770) and the plurality of first substrates (711).

[0130] Referring to FIG. 8, the flattening layer (715) includes a first surface (S1) and a second surface (S2) formed at a position lower than the first surface (S1). A first connection pad (191) and a second connection pad (192) are disposed on the first surface (S1) of the flattening layer (715), and a plurality of connection wires (780) may be disposed on the second surface (S2) and side of the flattening layer (715). At this time, a contact hole (CNT) is formed in the lower part of the second surface (S2) of the flattening layer (715) so that a plurality of connection wires (780) and a plurality of pads (770) can be connected. Specifically, the first connecting wire (781) can be connected to the gate pad (771) through a contact hole (CNT) formed in the flattening layer (715), and the second connecting wire (782) can be connected to the data pad (772) through a contact hole (CNT) formed in the flattening layer (715).

[0131] Referring to FIG. 8, a plurality of second substrates (120) are connected to a plurality of protrusions (711b). A plurality of connecting wires (780) may be arranged on the upper surface of the plurality of second substrates (120).

[0132] In a stretchable display device (700) according to another embodiment of the present invention, a plurality of contact holes (CNT) are arranged on a plurality of protrusions (711b) so that the area in which pixels (PX) and driving circuits are arranged on the first substrate (711) can be increased. The plurality of contact holes (CNT) are formed by etching a portion of the flattening layer (715) to connect a plurality of connecting wires (780) and a plurality of pads (770). In the process of forming these plurality of contact holes (CNT), the process margin between the end of the first substrate (711) and the plurality of contact holes (CNT), and the process margin between the pixel (PX) and the plurality of contact holes (CNT) must be taken into account; therefore, if the plurality of contact holes (CNT) are located in the central part (711a), the area in which pixels (PX), driving circuits, and wires are arranged in the central part (711a) can be reduced. Accordingly, in a stretchable display device (700) according to another embodiment of the present invention, a plurality of contact holes (CNT) are arranged on a plurality of protrusions (711b) so that a plurality of connecting wires (780) are connected to a plurality of pads (770) on the plurality of protrusions (711b), thereby increasing the area on which pixels (PX), driving circuits, wiring, etc. are arranged on the first substrate (711). For example, assuming that the width of the central part (711a) of the first substrate (711) is 177㎛, the size of one contact hole (CNT) is 5㎛*5㎛, and the process margin is 2.5㎛, approximately 11% additional usable area can be secured when the contact holes (CNT) are arranged on the protrusions (711b) as in another embodiment of the present invention compared to when the contact holes (CNT) are arranged on the central part (711a).

[0133] In a stretchable display device (700) according to another embodiment of the present invention, a plurality of pads (770) are arranged to be in contact with the upper surface of a plurality of first substrates (711), thereby reducing the step difference in which a plurality of connecting wires (780) are arranged. The plurality of pads (770) are arranged to be in contact with the upper surface of an interlayer insulating layer (114), a buffer layer (112), a gate insulating layer (113), the side of an interlayer insulating layer (114), and the upper surface of a plurality of first substrates (711), so as to be in contact with a plurality of connecting wires (780) on a plurality of protrusions (711b) of a plurality of first substrates (711). Accordingly, in a stretchable display device (700) according to another embodiment of the present invention, a plurality of pads (770) are arranged to be in contact with the upper surface of a plurality of first substrates (711), so that a plurality of connecting wires (780) can be arranged at a relatively low position, and thus, when the stretchable display device (700) is repeatedly stretched, the stress generated in the plurality of connecting wires (780) can be reduced, thereby reducing damage to the plurality of connecting wires (780).

[0134] In a stretchable display device (700) according to another embodiment of the present invention, the width of a plurality of protrusions (711b) of a plurality of first substrates (711) is reduced as it moves away from the central portion (711a), thereby reducing the stress generated in the plurality of protrusions (711b) in the portion connected to the central portion (711a) when the stretchable display device (700) is stretched. When the stretchable display device (700) is stretched, more stress is generated in the portion connected to the central portion (711a) of the plurality of first substrates (711) than in the portion connected to the plurality of second substrates (120), so damage to the plurality of protrusions (711b) may occur in the portion connected to the central portion (711a). Accordingly, the width of the plurality of protrusions (711b) is formed to be large in the part connected to the central part (711a) and becomes smaller as it moves away from the central part (711a), so that in the stretchable display device (700) according to another embodiment of the present invention, damage to the plurality of protrusions (711b) in the part connected to the central part (711a) can be reduced.

[0135] FIG. 10 is a schematic perspective view of one subpixel of a stretchable display device according to another embodiment of the present invention. Compared to the stretchable display device (1000) of FIG. 10, only the flattening layer (1015) is different, and other components are substantially the same, so a redundant description is omitted. In the stretchable display device (1000) of FIG. 10, for convenience of explanation, only a plurality of first substrates (111), a plurality of second substrates (120), a plurality of connecting wires (180), and a flattening layer (1015) are shown.

[0136] Referring to FIG. 10, a plurality of first substrates (111) include a plurality of first regions (A1) and a plurality of second regions (A2). A plurality of first regions (A1) is a region where a plurality of first substrates (111) and a plurality of second substrates (120) are connected, and a plurality of second regions (A2) is a region other than a plurality of first regions (A1). That is, a plurality of first regions (A1) is a region where a plurality of connecting wires (180) are arranged on a plurality of first substrates (111), and a plurality of second regions (A2) is a region where a plurality of connecting wires (180) are not arranged.

[0137] Referring to FIG. 10, the flattening layer (1015) may be arranged to have different inclination angles in a plurality of first regions (A1) and a plurality of second regions (A2). Specifically, the inclination angle of the flattening layer (1015a) arranged in the plurality of first regions (A1) may be smaller than the inclination angle of the flattening layer (1015b) arranged in the plurality of second regions (A2). Accordingly, a plurality of connecting wires (180) arranged on the flattening layer (1015a) of the plurality of first regions (A1) may be arranged to have a small inclination angle.

[0138] In a stretchable display device (1000) according to another embodiment of the present invention, the angle of inclination of the flattening layer (1015) can be selectively adjusted in an area where a plurality of connecting wires (180) are arranged. For example, the flattening layer (1015b) in a plurality of second areas (A2) where a plurality of connecting wires (180) are not arranged may be arranged with a large angle of inclination, but it is advantageous for the flattening layer (1015a) in a plurality of first areas (A1) where a plurality of connecting wires (180) are arranged to be arranged with a small angle of inclination. That is, the angle of inclination of the flattening layer (1015a) in a plurality of first areas (A1) where a plurality of connecting wires (180) are arranged may be formed to be smaller than the angle of inclination of the flattening layer (1015b) in a plurality of second areas (A2), so that the plurality of connecting wires (180) may be arranged with a small angle of inclination. Accordingly, by selectively adjusting the inclination angle of the flattening layer (1015) according to the region, the flattening layer (1015) of a plurality of first regions (A1) is arranged with a small inclination angle, thereby reducing damage to a plurality of connecting wires (180) when the stretchable display device (1000) is stretched.

[0139] FIG. 11 is a schematic cross-sectional view according to XI-XI' of FIG. 1 of another embodiment of the present invention. The stretchable display device (1100) of FIG. 11 is substantially identical to the stretchable display device (600) of FIG. 6 except that the plurality of inorganic insulating layers and organic insulating layers are different and an intermediate wiring (ML) and a third connecting pad (1193) are added, so a redundant description is omitted.

[0140] Referring to FIG. 11, a plurality of inorganic insulating layers are disposed on a plurality of first substrates (111) and a plurality of third substrates (121). The plurality of inorganic insulating layers may include a buffer layer (1112), an active buffer (1119), a gate insulating layer (1113), a first interlayer insulating layer (1114a), a second interlayer insulating layer (1114b), and a passivation layer (1194). The plurality of inorganic insulating layers disposed on the plurality of first substrates (111) and the plurality of inorganic insulating layers disposed on the plurality of third substrates (121) may be disposed spaced apart from each other.

[0141] A buffer layer (1112) is disposed on a plurality of first substrates (111) and a plurality of third substrates (121). The buffer layer (1112) may be referred to as a first inorganic insulating layer. The buffer layer (1112) may include a first portion (P1) and a second portion (P2). The first portion (P1) of the buffer layer (1112) may have a first width (W1) and be disposed to be in contact with the upper surface of a plurality of first substrates (111). And, the second portion (P2) of the buffer layer (1112) may have a second width (W2) and be disposed on the first portion (P1). The second width (W2) of the second portion (P2) of the buffer layer (1112) may be smaller than the first width (W1) of the first portion (P1). That is, the buffer layer (1112) may have a stepped side.

[0142] An active buffer (1119) and a gate insulating layer (1113) are disposed on the buffer layer (1112). The active buffer (1119) and the gate insulating layer (1113) may be referred to as a second inorganic insulating layer.

[0143] An active buffer (1119) is placed on a buffer layer (1112). The active buffer (1119) may be placed so as to have a width equal to the second width (W2) of the second part (P2) of the buffer layer (1112) and to be in contact with the upper surface of the second part (P2) of the buffer layer (1112). However, it is not limited thereto, and the active buffer (1119) may be placed so as to have a width smaller than the second width (W2) of the second part (P2) of the buffer layer (1112).

[0144] An active layer (152) is disposed on the active buffer (1119), and a gate insulating layer (1113) is disposed on the active buffer (1119) and the active layer. The gate insulating layer (1113) may have the same width as the active buffer (1119). That is, the gate insulating layer (1113) may be formed to have the same width by being formed simultaneously in the same process as the active buffer (1119). Accordingly, the gate insulating layer (1113) may have the same width as the second width (W2) of the second part (P2) of the buffer layer (1112). However, it is not limited thereto, and the gate insulating layer (1113) may be disposed to have a width smaller than the second width (W2) of the second part (P2) of the buffer layer (1112).

[0145] A gate electrode (151) is disposed on the gate insulating layer (1113). The gate electrode (151) may be disposed to overlap with the active layer (152) or BSM (618), but is not limited thereto.

[0146] An interlayer insulating layer (1114) and a passivation layer (1194) are disposed on the gate insulating layer (1113). The interlayer insulating layer (1114) and the passivation layer (1194) may be referred to as a third inorganic insulating layer.

[0147] The interlayer insulation layer (1114) may include a first interlayer insulation layer (1114a) and a second interlayer insulation layer (1114b).

[0148] The first interlayer insulating layer (1114a) is disposed on the gate electrode (151) and the gate insulating layer (1113). The first interlayer insulating layer (1114a) may be disposed to cover the upper and side surfaces of the gate insulating layer (1113), the side surface of the active buffer (1119), and the upper and side surfaces of the buffer layer (1112). At this time, the first interlayer insulating layer (1114a) may be disposed to cover the upper surface of the first part (P1) and the side surface of the second part (P2) of the buffer layer (1112).

[0149] An intermediate wiring (ML) is disposed on the first interlayer insulating layer (1114a). The intermediate wiring (ML) can contact the BSM (618) through contact holes formed in the first interlayer insulating layer (1114a), the gate insulating layer (1113), and the active buffer (1119). The intermediate wiring (ML) is configured to apply a constant voltage to the BSM (618) and is a wiring for electrically connecting the source electrode (1153) and the BSM (618). However, if the length of the intermediate wiring (ML) is designed to be short according to the design of the BSM (618) and the transistor (1150), the intermediate wiring (ML) may be referred to as an intermediate electrode.

[0150] A second interlayer insulation layer (1114b) is disposed on the first interlayer insulation layer (1114a) and the intermediate wiring (ML). The second interlayer insulation layer (1114b) may be disposed to cover the upper surface and the side surface of the first interlayer insulation layer (1114a).

[0151] A source electrode (1153), a drain electrode (1154), and a third connection pad (1193) are disposed on the second interlayer insulating layer (1114b).

[0152] The source electrode (1153) and the drain electrode (1154) can be electrically connected to the active layer (152) through contact holes formed in the gate insulating layer (1113), the first interlayer insulating layer (1114a), and the second interlayer insulating layer (1114b). At this time, the source electrode (1153) can be electrically connected to the active layer (152) through an intermediate wiring (ML) placed on the first interlayer insulating layer (1114a).

[0153] The third connection pad (1193) is disposed on the second interlayer insulating layer (1114b) formed on a plurality of third substrates (121). The third connection pad (1193) can be electrically connected to a source electrode (1153) or a drain electrode (1154) formed on a plurality of first substrates (111) through a second connection wire (1182). The third connection pad (1193) is a pad to which the COF (130) is bonded, and can be used as a pad for transmitting a signal from the COF (130) to a subpixel.

[0154] A passivation layer (1194) is disposed on the second interlayer insulating layer (1114b). The passivation layer (1194) may be disposed to cover a portion of the upper and side surfaces of the source electrode (1153), drain electrode (1154), and the second interlayer insulating layer (1114b) on a plurality of first substrates (111). The passivation layer (1194) may function as a protective layer to protect the transistor (1150) from the penetration of moisture and oxygen. The passivation layer (1194) may be made of an inorganic material and may be a single layer or a multilayer, but is not limited thereto.

[0155] A flattening layer (1115) is disposed on a passivation layer (1194). The flattening layer (1115) may be disposed to cover the upper and side surfaces of a plurality of inorganic insulating layers disposed on a plurality of first substrates (111) and a plurality of third substrates (121). Specifically, the flattening layer (1115) may be disposed to cover the upper and side surfaces of the passivation layer (1194), the side surfaces of the interlayer insulating layer (1114), and a portion of the side surfaces of the buffer layer (1112).

[0156] A second connecting wire (1182) is disposed on the flattening layer (1115). The second connecting wire (1182) may be disposed to cover a portion of the upper surface and side of the flattening layer (1115) and the upper surface of a plurality of second substrates (120).

[0157] The second connecting wire (1182) can be electrically connected to the source electrode (1153) or drain electrode (1154) and the third connecting pad (1193) through a contact hole formed in the passivation layer (1194) and the flattening layer (1115). At this time, the second connecting wire (1182) can electrically connect the source electrode (1153) or drain electrode (1154) disposed on a plurality of first substrates (111) and the third connecting pad (1193) disposed on a plurality of third substrates (121).

[0158] Meanwhile, in some embodiments, the buffer layer (1112) may have a first portion (P1) and a second portion (P2) arranged with the same width. That is, the second width (W2) of the second portion (P2) of the buffer layer (1112) may be formed to be equal to the first width (W1) of the first portion (P1), so that the width of the buffer layer (1112) may be defined as the first width (W1). At this time, the active buffer (1119) may include a first portion (P1) and a second portion (P2) on the first portion (P1), and the first portion (P1) of the active buffer (1119) may have a first width (W1), and the second portion (P2) of the active buffer (1119) may have a second width (W2) that is smaller than the first width (W1) of the first portion (P1). Alternatively, the active buffer (1119) may have a first width (W1) equal to the first width (W1) of the buffer layer (1112), and the gate insulating layer (1113) may include a first portion (P1) and a second portion (P2) on the first portion (P1), and the first portion (P1) of the gate insulating layer (1113) may have a first width (W1), and the second portion (P2) of the gate insulating layer (1113) may have a second width (W2) smaller than the first width (W1) of the first portion (P1).

[0159] Additionally, in some embodiments, the buffer layer (1112) may have a first portion (P1) and a second portion (P2) arranged with the same width. That is, the second width (W2) of the second portion (P2) of the buffer layer (1112) may be formed to be equal to the first width (W1) of the first portion (P1), so that the width of the buffer layer (1112) may be defined as the first width (W1). In this case, the active buffer (1119) and the gate insulating layer (1113) may be formed to have a second width (W2) that is smaller than the first width (W1). Accordingly, the buffer layer (1112), the active buffer (1119), and the gate insulating layer (1113) may together form a stepped shape.

[0160] FIGS. 12a to 12m are process diagrams for explaining the manufacturing process of the stretchable display device of FIG. 11.

[0161] First, referring to FIG. 12a, a sacrificial layer (SL) and a temporary substrate (1211) are placed on an auxiliary substrate (SS). The auxiliary substrate (SS) is a substrate for supporting the temporary substrate (1211) during the manufacturing process of the stretchable display device (1100) described later. The auxiliary substrate (SS) may be a glass substrate, but is not limited thereto.

[0162] A sacrificial layer (SL) is disposed on an auxiliary substrate (SS). The sacrificial layer (SL) is a layer used to separate the auxiliary substrate (SS) from the temporary substrate (1211). When a laser is irradiated onto the sacrificial layer (SL), the adhesion between the auxiliary substrate (SS) and the temporary substrate (1211) may be weakened, and the auxiliary substrate (SS) may be removed from the temporary substrate (1211) by irradiating the sacrificial layer (SL) with a laser. The sacrificial layer (SL) may be made of amorphous silicon (a-Si) or silicon nitride (SiNx), but is not limited thereto.

[0163] Next, a temporary substrate (1211) is placed on the sacrificial layer (SL). A rigid region (SA) and a flexible region (EA) may be defined in the temporary substrate (1211). Specifically, the temporary substrate (1211) may have a portion removed in a subsequent process to become a plurality of first substrates (111), a plurality of second substrates (120), or a plurality of third substrates (121). For example, the rigid region (SA) of the temporary substrate (1211) may become a plurality of first substrates (111) or a plurality of third substrates (121), and the flexible region (EA) of the temporary substrate (1211) may become a plurality of second substrates (120). Accordingly, the temporary substrate (1211) may be made of a flexible plastic material such as polyimide (PI), polyacrylate, or polyacetate, but is not limited thereto.

[0164] Next, a buffer layer material (1212) is formed on a temporary substrate (1211). Specifically, the buffer layer material (1212) may be formed in the rigid region (SA) and the flexible region (EA) of the temporary substrate (1211). The buffer layer material (1212) may be referred to as a first inorganic insulating material. For example, the buffer layer material (1212) may be an inorganic insulating material composed of silicon nitride (SiNx), silicon oxide (SiOx), silicon oxynitride (SiON), etc.

[0165] Next, a BSM (618) is formed on the buffer layer material (1212), and an active buffer material (1219) is formed on the buffer layer material (1212) and the BSM (618). The active buffer material (1219) may be referred to as a second inorganic insulating material. Specifically, the active buffer material (1219) may be formed in the rigid region (SA) and the flexible region (EA) of the temporary substrate (1211). The active buffer material (1219) may be an inorganic insulating material composed of silicon nitride (SiNx) or silicon oxide (SiOx).

[0166] Next, an active layer (152) is formed on the active buffer material (1219), and a gate insulating layer material (1213) is formed on the active buffer material (1219) and the active layer. The gate insulating layer material (1213) may be referred to as a second inorganic insulating material. The gate insulating layer material (1213) may be an inorganic insulating material composed of silicon nitride (SiNx) or silicon oxide (SiOx).

[0167] Next, a gate electrode (151) is formed on the gate insulating layer material (1213).

[0168] Next, referring to FIG. 12b, a second inorganic insulating material disposed in a part of the flexible region (EA) and the rigid region (SA) adjacent to the flexible region (EA) is removed to form a second inorganic insulating layer. Specifically, an active buffer material (1219) and a gate insulating layer material (1213) disposed in a part of the flexible region (EA) and the rigid region (SA) adjacent to the flexible region (EA) are removed to form an active buffer (1119) and a gate insulating layer (1113). The active buffer (1119) and the gate insulating layer (1113) can be formed by forming a photoresist (PR) on the active buffer material (1219) and the gate insulating layer material (1213) placed in another part of the rigid region (SA), and then removing the active buffer material (1219) and the gate insulating layer material (1213) placed in the flexible region (EA) and the part of the rigid region (SA) adjacent to the flexible region (EA). Accordingly, only the buffer layer material (1212) may remain in the flexible region (EA) and the part of the rigid region (SA) adjacent to the flexible region (EA).

[0169] Meanwhile, the step of forming the second inorganic insulating layer may include the step of removing a portion of the first inorganic insulating material disposed in a portion of the flexible region (EA) and a portion of the rigid region (SA) adjacent to the flexible region (EA), excluding the portion overlapping with the active buffer (1119) and the gate insulating layer (1113). For example, in the step of forming the second inorganic insulating layer, a portion of the buffer layer material (1212) disposed in a portion of the flexible region (EA) and a portion of the rigid region (SA) adjacent to the flexible region (EA) may be removed. Accordingly, only a portion of the buffer layer material (1212) having a thickness smaller than the thickness of the buffer layer material (1212) disposed in the rigid region (SA) may be disposed in a portion of the flexible region (EA) and a portion of the rigid region (SA) adjacent to the flexible region (EA).

[0170] Next, referring to FIG. 12c and FIG. 12d, a third inorganic insulating material is formed on the first inorganic insulating material and the second inorganic insulating layer. The third inorganic insulating material may include the first interlayer insulating material (1214a), the second interlayer insulating material (1214b), and the material for the passivation layer (1294).

[0171] First, referring to FIG. 12c, a first interlayer insulating material (1214a) is formed on a buffer layer material (1212), an active buffer (1119), and a gate insulating layer (1113). The first interlayer insulating material (1214a) may be made of an inorganic insulating material such as silicon nitride (SiNx) or silicon oxide (SiOx).

[0172] Next, an intermediate wiring (ML) is formed on the first interlayer insulating material (1214a). The intermediate wiring (ML) can be connected to the BSM (618) through the contact holes of the first interlayer insulating material (1214a), the gate insulating layer (1113), and the active buffer (1119).

[0173] Next, referring to FIG. 12d, a second interlayer insulating material (1214b) is formed on the first interlayer insulating material (1214a) and the intermediate wiring (ML). The second interlayer insulating material (1214b) may be the same as the first interlayer insulating material (1214a), but is not limited thereto.

[0174] Next, a source electrode (1153), a drain electrode (1154), and a third connection pad (1193) are formed on the second interlayer insulating material (1214b), and a passivation layer material (1194) is formed on the second interlayer insulating material (1214b), the source electrode (1153), the drain electrode (1154), and the third connection pad (1193). The passivation layer material (1194) may be made of an inorganic material that prevents moisture and oxygen from penetrating into the interior of the stretchable display device (1100).

[0175] Next, referring to FIG. 12e, the first inorganic insulating material and the third inorganic insulating material placed in the flexible region (EA) and the rigid region (SA) adjacent to the flexible region (EA) may be removed to form the first inorganic insulating layer and the third inorganic insulating layer. Specifically, the buffer layer material (1212), the first interlayer insulating layer material (1214a), the second interlayer insulating layer material (1214b), and the passivation layer material (1294) placed in the flexible region (EA) and the rigid region (SA) adjacent to the flexible region (EA) may be removed to form the buffer layer (1112), the first interlayer insulating layer (1114a), the second interlayer insulating layer (1114b), and the passivation layer (1194). The buffer layer (1112), the first interlayer insulating layer (1114a), the second interlayer insulating layer (1114b), and the passivation layer (1194) can be formed by coating a photoresist (PR) on a buffer layer material (1212), a first interlayer insulating layer material (1214a), a second interlayer insulating layer material (1214b), and a passivation layer material (1294) disposed on a part of the rigid region (SA), and then removing the buffer layer material (1212), the first interlayer insulating layer material (1214a), the second interlayer insulating layer material (1214b), and the passivation layer material (1294) disposed on the flexible region (EA) and the rigid region (SA) adjacent to the flexible region (EA). Accordingly, a plurality of inorganic insulating layers may not be disposed in the flexible region (EA) and the rigid region (SA) adjacent to the flexible region (EA), and the upper surface of the temporary substrate (1211) of the flexible region (EA) and the rigid region (SA) adjacent to the flexible region (EA) may be exposed.

[0176] Next, referring to FIG. 12f, a flattening layer (1115) is formed on the passivation layer (1194). The flattening layer (1115) may be referred to as an organic insulating layer. The flattening layer (1115) may be formed by patterning after a flattening layer material is formed on the passivation layer (1194). Accordingly, the flattening layer (1115) may be patterned so that a part of the drain electrode (1154), the upper surface of the temporary substrate (1211), and a part of the third connection pad (1193) are exposed.

[0177] Next, referring to FIG. 12g, a second connecting wire (1182) is formed on a flattening layer (1115) and a temporary substrate (1211). The second connecting wire (1182) can connect adjacent rigid regions (SA) among a plurality of rigid regions (SA) on the temporary substrate (1211). For example, as shown in FIG. 12g, the second connecting wire (1182) can electrically connect a drain electrode (1154) placed in one of the plurality of rigid regions (SA) and a third connecting pad (1193) placed in another rigid region (SA).

[0178] Referring to FIGS. 12h and 12i, a mask pattern (MP) is formed on a planarization layer (1115) and a second connecting wire (1182). The mask pattern (MP) can be used to remove a temporary substrate (1211) in an area that does not overlap with an organic insulating layer and a plurality of connecting wires. Specifically, after forming the mask pattern (MP) on the planarization layer (1115) and the second connecting wire (1182), the temporary substrate (1211) can be removed in an area of ​​the flexible region (EA) where the second connecting wire (1182) is not placed, thereby forming a plurality of first substrates (111) and a plurality of second substrates (120). Accordingly, the mask pattern (MP) may be made of a material that has a smaller etching ratio to the etchant than the temporary substrate (1211). For example, when etching a temporary substrate (1211) using a photoresist (PR), the photoresist (PR) may be etched before the temporary substrate (1211). Accordingly, the mask pattern (MP) may be made of a transparent conductive oxide of the indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), zinc oxide (ZnO), and tin oxide (TO) series, but is not limited thereto.

[0179] Referring to FIG. 12j and FIG. 12k, after a plurality of first substrates (111) and a plurality of second substrates (120) are formed, a mask pattern (MP) formed on a flattening layer (1115) and a second connecting wire (1182) is removed.

[0180] Referring to FIG. 121 and FIG. 12m, after the auxiliary substrate (SS) and sacrificial layer (SL) placed below the plurality of first substrates (111) and the plurality of second substrates (120) are removed, a lower substrate (110) is placed. The lower substrate (110) is placed below the plurality of first substrates (111) and the plurality of second substrates (120) and can support and protect various components placed on the plurality of first substrates (111) and the plurality of second substrates (120).

[0181] In a method for manufacturing a stretchable display device (1100) according to another embodiment of the present invention, the inorganic insulating material on a temporary substrate (1211) is not removed in a single process, but is removed in multiple steps. That is, as described above, a method for manufacturing a stretchable display device (1100) according to another embodiment of the present invention first performs a patterning process for a buffer layer material (1212), an active buffer material (1219), and a gate insulating layer material (1213) to first form a buffer layer (1112), an active buffer (1119), and a gate insulating layer (1113), and then performs a patterning process for a first interlayer insulating layer material (1214a), a second interlayer insulating layer material (1214b), and a passivation layer material (1294) to form a first interlayer insulating layer (1114a), a second interlayer insulating layer (1114b), and a passivation layer (1194). In a method for manufacturing a stretchable display device (1100) according to another embodiment of the present invention, a buffer layer material (1212), an active buffer material (1219), a gate insulating layer material (1213), a first interlayer insulating layer material (1214a), a second interlayer insulating layer material (1214b), and a passivation layer material (1294) disposed in a flexible region (EA) must be removed. However, since the flexible region (EA) is a very large area compared to the rigid region (SA), it is very difficult to remove all inorganic materials disposed in a large area in a single process in terms of uniformity. Accordingly, in a method for manufacturing a stretchable display device (1100) according to another embodiment of the present invention, after performing a patterning process for a buffer layer material (1212), an active buffer material (1219), and a gate insulating layer material (1213), a patterning process for a first interlayer insulating layer material (1214a), a second interlayer insulating layer material (1214b), and a passivation layer material (1294) is performed, thereby ensuring uniformity in the process of patterning inorganic materials.

[0182] In addition, in a method for manufacturing a stretchable display device (1100) according to another embodiment of the present invention, by leaving a portion of the first inorganic insulating material on the flexible region (EA) and the rigid region (SA) adjacent to the flexible region (EA) and patterning it in the step of forming the second inorganic insulating layer, the peeling of the inorganic material or the metal material from the temporary substrate (1211) during the subsequent process of forming the inorganic material or the metal material can be reduced. For example, if all of the first inorganic insulating material disposed on the flexible region (EA) and the rigid region (SA) adjacent to the flexible region (EA) is removed in the step of forming the second inorganic insulating layer, the inorganic material or the metal material formed in the subsequent process may be formed on the temporary substrate (1211). However, since the surface energy of the first inorganic insulating material and the temporary substrate (1211) made of organic material is different, when the inorganic material or the metal material is formed on the temporary substrate (1211), the inorganic material or the metal material may be peeled off from the temporary substrate (1211). Accordingly, in the step of forming the second inorganic insulating layer, a portion of the first inorganic insulating material is left on the flexible region (EA) and the rigid region (SA) adjacent to the flexible region (EA) and patterned so that the inorganic material or metal material is deposited on the first inorganic insulating material in a subsequent process, thereby reducing the peeling of the inorganic material or metal material.

[0183] In addition, in the method for manufacturing a stretchable display device (1100) according to another embodiment of the present invention, by leaving a portion of the first inorganic insulating material on the flexible region (EA) and the rigid region (SA) adjacent to the flexible region (EA) and patterning it in the step of forming the second inorganic insulating layer, the occurrence of an undercut on the temporary substrate (1211) can be reduced. For example, if all of the first inorganic insulating material is removed on the flexible region (EA) and the rigid region (SA) adjacent to the flexible region (EA) in the step of forming the second inorganic insulating layer, the portion of the temporary substrate (1211) coated with photoresist (PR) and a portion of the adjacent rigid region (SA) are etched together, and an undercut may occur on the temporary substrate (1211). However, if an undercut occurs on a portion of the temporary substrate (1211), the inorganic material or metal material deposited in a subsequent process may be interrupted by the undercut. Accordingly, by patterning while leaving a portion of the first inorganic insulating material on the flexible region (EA) and the rigid region (SA) adjacent to the flexible region (EA), the occurrence of undercuts on the temporary substrate (1211) can be reduced, and the inorganic material or metal material can be deposited without interruption in a subsequent process.

[0184] FIG. 13 is a schematic cross-sectional view of one subpixel of a stretchable display device according to another embodiment of the present invention. The stretchable display device (1300) of FIG. 13 is different from the stretchable display device (100) of FIG. 1 to 3 only in the organic light-emitting element (1360) and bank (1316), and since the other configurations are substantially the same, a redundant description is omitted.

[0185] Referring to FIG. 13, the organic light-emitting element (1360) is a component that is arranged to correspond to each of a plurality of subpixels (SPX) and emits light having a specific wavelength range. That is, the organic light-emitting element (1360) may be a blue organic light-emitting element that emits blue light, a red organic light-emitting element that emits red light, a green organic light-emitting element that emits green light, or a white organic light-emitting element that emits white light, but is not limited thereto. When the organic light-emitting element (1360) is a white organic light-emitting element, the stretchable display device (1300) may further include a color filter.

[0186] The organic light-emitting element (1360) includes an anode (1361), an organic light-emitting layer (1362), and a cathode (1363). Specifically, the anode (1361) is disposed on a planarization layer (115). The anode (1361) is an electrode configured to supply holes to the organic light-emitting layer (1362). The anode (1361) may be composed of a transparent conductive material with a high work function. Here, the transparent conductive material may include indium tin oxide (ITO), indium zinc oxide (IZO), and indium tin zinc oxide (ITZO). Additionally, if the stretchable display device (1300) is implemented in a top emission manner, the anode (1361) may further include a reflector.

[0187] The anode (1361) is spaced apart from each subpixel (SPX) and electrically connected to the transistor (150) through the contact hole of the flattening layer (115). For example, in FIG. 13, the anode (1361) is shown as being electrically connected to the drain electrode (154) of the transistor (150), but it may also be electrically connected to the source electrode (153).

[0188] A bank (1316) is formed on an anode (1361), a connecting wire (180), and a flattening layer (115). The bank (1316) is a component that separates adjacent subpixels (SPX). The bank (1316) is positioned to cover at least a portion of both sides of an adjacent anode (1361) so as to expose a portion of the upper surface of the anode (1361). The bank (1316) may also serve to prevent the problem of unintended subpixels (SPX) emitting light or mixing colors, which occurs when light is emitted in the lateral direction of the anode (1361) due to current concentration at the corners of the anode (1361). The bank (1316) may be made of an acrylic resin, a benzocyclobutene (BCB) resin, or a polyimide, but is not limited thereto.

[0189] The bank (1316) includes a contact hole connecting a connection wire (180) that functions as a data wire and a data pad (172), and a contact hole connecting a connection wire (180) that functions as a gate wire and a gate pad (171).

[0190] An organic light-emitting layer (1362) is disposed on an anode (1361). The organic light-emitting layer (1362) is configured to emit light. The organic light-emitting layer (1362) may include a light-emitting material, and the light-emitting material may include a phosphorescent material or a fluorescent material, but is not limited thereto.

[0191] The organic light-emitting layer (1362) may be composed of a single light-emitting layer. Alternatively, the organic light-emitting layer (1362) may have a stack structure in which a plurality of light-emitting layers are stacked with a charge generation layer in between. Additionally, the organic light-emitting layer (1362) may further include at least one organic layer among a hole transport layer, an electron transport layer, a hole blocking layer, an electron blocking layer, a hole injection layer, and an electron injection layer.

[0192] Referring to FIG. 13, a cathode (1363) is placed on an organic light-emitting layer (1362). The cathode (1363) supplies electrons to the organic light-emitting layer (1362). The cathode (1363) may be made of a transparent conductive oxide of the indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), zinc oxide (ZnO), and tin oxide (TO) series, or an ytterbium (Yb) alloy. Alternatively, the cathode (1363) may be made of a metallic material.

[0193] The cathode (1363) can be formed by patterning so as to overlap with each of the plurality of first substrates (111). That is, the cathode (1363) can be formed only in the area overlapping with the plurality of first substrates (111) and arranged so as not to be formed in the area between the plurality of first substrates (111). Since the cathode (1363) is made of a material such as a transparent conductive oxide or a metal material, if the cathode (1363) is also formed in the area between the plurality of first substrates (111), the cathode (1363) may be damaged during the process of stretching the stretchable display device (1300). Accordingly, the cathode (1363) can be formed to correspond to each of the plurality of first substrates (111) on a flat surface. Referring to FIG. 13, the cathode (1363) may be formed to have an area that does not overlap with the area where the connecting wiring (180) is placed in the area that overlaps with the plurality of first substrates (111).

[0194] Unlike a general organic light-emitting display device, in a stretchable display device (1300) according to another embodiment of the present invention, a cathode (1363) is patterned and formed to correspond to a plurality of first substrates (111). Accordingly, each of the cathodes (1363) placed on the plurality of first substrates (111) can independently receive a low-potential power supply through a connecting wire (180).

[0195] Referring to FIG. 13, an encapsulation layer (1317) is disposed on an organic light-emitting element (1360). The encapsulation layer (1317) covers the organic light-emitting element (1360) and can seal the organic light-emitting element (1360) by contacting a portion of the upper surface of the bank (1316). Accordingly, the encapsulation layer (1317) protects the organic light-emitting element (1360) from moisture, air, or physical shock that may penetrate from the outside.

[0196] The encapsulation layer (1317) covers each of the cathodes (1363) patterned to overlap with each of the plurality of first substrates (111), and can be formed for each of the plurality of first substrates (111). That is, the encapsulation layer (1317) is arranged to cover one cathode (1363) placed on one first substrate (111), and the encapsulation layers (1317) placed on each of the plurality of first substrates (111) can be spaced apart from each other.

[0197] The encapsulation layer (1317) may be formed only in the area overlapping with the plurality of first substrates (111). As described above, since the encapsulation layer (1317) may be configured to include an inorganic layer, it may be easily damaged, such as by cracking, during the stretching process of the stretchable display device (1300). In particular, since the organic light-emitting element (1360) is vulnerable to moisture or oxygen, the reliability of the organic light-emitting element (1360) may be reduced if the encapsulation layer (1317) is damaged. Accordingly, in the stretchable display device (1300) according to another embodiment of the present invention, the encapsulation layer (1317) is not formed in the area between the plurality of first substrates (111), so that damage to the encapsulation layer (1317) can be minimized even when the stretchable display device (1300) is deformed, such as by bending or stretching.

[0198] A stretchable display device according to various embodiments of the present invention can be described as follows.

[0199] A stretchable display device according to one embodiment of the present invention may include a lower substrate, a plurality of first substrates disposed on the lower substrate and having subpixels defined therein, a plurality of second substrates connecting adjacent first substrates among the plurality of first substrates, a plurality of inorganic insulating layers disposed on the plurality of first substrates, an organic insulating layer disposed on the plurality of first substrates to cover the upper surface and side surface of the plurality of inorganic insulating layers, and a plurality of connecting wires disposed on the organic insulating layer and the plurality of second substrates.

[0200] According to another feature of the present invention, a plurality of connecting wires are made of a metallic material and can be arranged to be in contact with an organic insulating layer and a plurality of second substrates.

[0201] According to another feature of the present invention, at least a portion of the surface of the organic insulating layer in contact with a plurality of connecting wires may have a wrinkled structure.

[0202] According to another feature of the present invention, a plurality of first substrates include a first portion having a first thickness and a second portion having a second thickness smaller than the first thickness, and an organic insulating layer may be arranged to cover the second portion.

[0203] According to another feature of the present invention, a plurality of second substrates are connected to a second part and may have the same thickness as the second part.

[0204] According to another feature of the present invention, the first part adjacent to the second part may have an undercut shape.

[0205] According to another feature of the present invention, the angle of inclination of the side of the organic insulating layer may be smaller than the angle of inclination formed by the side of the plurality of inorganic insulating layers.

[0206] According to another feature of the present invention, a plurality of first substrates include a plurality of first regions connected to a plurality of second substrates and a plurality of second regions excluding the plurality of first regions, and the angle of inclination of the side of an organic insulating layer disposed in the plurality of first regions may be smaller than the angle of inclination of the side of an organic insulating layer disposed in the plurality of second regions.

[0207] According to another feature of the present invention, the stretchable display device further comprises a plurality of pads disposed between a plurality of first substrates and an organic insulating layer, and a plurality of connecting wires electrically connect a plurality of pads disposed on adjacent first substrates among a plurality of first substrates, and the plurality of pads may be disposed on the same layer with the same material as any one of a plurality of conductive elements disposed on a plurality of first substrates.

[0208] According to another feature of the present invention, the stretchable display device further comprises a thin-film transistor disposed on a plurality of first substrates and a metal pattern disposed between the plurality of first substrates and the thin-film transistor, and a plurality of pads may be disposed on the same layer with the same material as the metal pattern.

[0209] According to another feature of the present invention, a plurality of first substrates include a central portion where a subpixel is defined and a plurality of protrusions protruding from the central portion, and a plurality of contact holes where a plurality of pads and a plurality of connecting wires come into contact may be disposed on the plurality of protrusions.

[0210] According to another feature of the present invention, a plurality of second substrates are connected to a plurality of protrusions, and a plurality of connecting wires may be disposed on a plurality of protrusions among a central portion and a plurality of protrusions.

[0211] According to another feature of the present invention, the width of a plurality of protrusions may decrease as they move away from the center.

[0212] According to another feature of the present invention, a plurality of inorganic insulating layers may include a first inorganic insulating layer on a plurality of first substrates, a second inorganic insulating layer disposed on the first inorganic insulating layer and having a width smaller than the width of the first inorganic insulating layer, and a third inorganic insulating layer disposed to cover the upper surface and side surface of the second inorganic insulating layer and a portion of the upper surface of the first inorganic insulating layer.

[0213] According to another feature of the present invention, a plurality of inorganic insulating layers may comprise a first inorganic insulating layer disposed on a plurality of first substrates and comprising a first portion having a first width and a second portion disposed on the first portion having a second width smaller than the first width, a second inorganic insulating layer on the second portion, and a third inorganic insulating layer disposed to cover the upper surface and side surface of the second inorganic insulating layer and a portion of the upper surface of the first inorganic insulating layer.

[0214] According to another feature of the present invention, the width of the second inorganic insulating layer may be smaller than or equal to the second width.

[0215] According to another feature of the present invention, the stretchable display device further includes a metal pattern disposed between a plurality of first substrates and thin-film transistors, and the metal pattern may be disposed between a first inorganic insulating layer and a second inorganic insulating layer.

[0216] According to another feature of the present invention, the stretchable display device further comprises a metal pattern disposed between a plurality of first substrates and thin-film transistors, and the second inorganic insulating layer is plurality, and the metal pattern may be disposed between a plurality of second inorganic insulating layers.

[0217] A stretchable display device according to another embodiment of the present invention comprises a plurality of rigid substrates disposed on a flexible substrate and having a plurality of display elements disposed thereon, a plurality of connecting substrates connecting the plurality of rigid substrates between the plurality of rigid substrates, a plurality of inorganic insulating layers disposed on the plurality of rigid substrates, an organic insulating layer surrounding the plurality of inorganic insulating layers together with the plurality of rigid substrates, and a plurality of connecting wires disposed to be in contact with the surface of the organic insulating layer, wherein the angle of inclination of the side of the organic insulating layer may be smaller than the angle of inclination of the side of the plurality of inorganic insulating layers.

[0218] According to another feature of the present invention, the surface of an organic insulating layer in contact with a plurality of connecting wires may have a curved shape in at least a portion.

[0219] According to another feature of the present invention, the thickness of a plurality of rigid substrates is greater than the thickness of a plurality of connecting substrates, and the plurality of rigid substrates may have an undercut shape in a portion adjacent to the plurality of connecting substrates.

[0220] According to another feature of the present invention, a stretchable display device further comprises a thin-film transistor disposed on a plurality of rigid substrates and a metal pattern disposed between the plurality of rigid substrates and the thin-film transistor, and a plurality of connecting wires can be electrically connected to a plurality of pads disposed on the same layer as the metal pattern.

[0221] According to another feature of the present invention, a plurality of rigid substrates include a plurality of protrusions connected to a plurality of connecting substrates, and a plurality of connecting wires can be electrically connected to a plurality of pads on the plurality of protrusions.

[0222] A method for manufacturing a stretchable display device according to another embodiment of the present invention may include the steps of: forming a temporary substrate having a plurality of rigid regions and flexible regions defined on an auxiliary substrate; forming a first inorganic insulating material on the temporary substrate; forming a second inorganic insulating material on the first inorganic insulating material; removing the second inorganic insulating material disposed in the flexible region to form a second inorganic insulating layer; forming a third inorganic insulating material on the first inorganic insulating material and the second inorganic insulating layer; removing the first inorganic insulating material and the third inorganic insulating material disposed in the flexible region to expose the flexible region to form a first inorganic insulating layer and a third inorganic insulating layer; forming an organic insulating layer to cover the upper surface and side surface of the third inorganic insulating layer; forming a plurality of connecting wires connecting adjacent rigid regions among a plurality of rigid regions on the organic insulating layer and the temporary substrate; and removing the temporary substrate disposed in a region other than the region where the plurality of connecting wires are disposed among the flexible regions to form a plurality of first substrates in a plurality of rigid regions and a plurality of second substrates in a flexible region.

[0223] According to another feature of the present invention, the second inorganic insulating layer has a width smaller than the width of the first inorganic insulating layer, and the third inorganic insulating layer may be arranged to cover the upper surface and side surface of the second inorganic insulating layer and a portion of the upper surface of the first inorganic insulating layer.

[0224] According to another feature of the present invention, the step of forming a second inorganic insulating layer includes the step of removing a portion of a first inorganic insulating material excluding a portion that overlaps with the second inorganic insulating layer, and the first inorganic insulating layer includes a first portion having a first width and a second portion disposed on the first portion and overlapping with the second inorganic insulating layer having a second width smaller than the first width, the second inorganic insulating layer is disposed on the second portion, and a third inorganic insulating layer may be disposed to cover the upper surface and side surface of the second inorganic insulating layer and a portion of the upper surface of the first inorganic insulating layer.

[0225] According to another feature of the present invention, a method for manufacturing a stretchable display device may further include the steps of removing an auxiliary substrate below a plurality of first substrates and a plurality of second substrates, and placing a lower substrate below a plurality of first substrates and a plurality of second substrates.

[0226] According to another feature of the present invention, a method for manufacturing a stretchable display device may include the step of forming a plurality of first substrates and a plurality of second substrates, the step of forming a mask pattern of a material having an etching ratio smaller than that of an etchant used to etch a temporary substrate than that of an organic insulating layer and a plurality of connecting wires, and the step of removing a temporary substrate that does not overlap with the organic insulating layer and the plurality of connecting wires using the mask pattern.

[0227] According to another feature of the present invention, the mask pattern may be made of a transparent conductive material.

[0228] Although embodiments of the present invention have been described in more detail with reference to the attached drawings, the present invention is not necessarily limited to these embodiments and may be modified in various ways within the scope of the technical spirit of the present invention. Accordingly, the embodiments disclosed in the present invention are intended to explain, not limit, the technical spirit of the present invention, and the scope of the technical spirit of the present invention is not limited by these embodiments. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. The scope of protection of the present invention shall be interpreted by the claims below, and all technical spirits within an equivalent scope shall be interpreted as being included within the scope of rights of the present invention. Explanation of the symbols

[0230] 100, 400, 500, 600, 700, 900, 1000, 1100, 1300: Stretchable display 110: Lower substrate 111, 411, 711: First substrate 1211: Temporary board 711a: Central part 711b: protrusion 112, 1112: Buffer layer 1212: Material for buffer layer 113, 613, 1113: Gate insulation layer 1213: Material for gate insulating layer 114, 614, 1114: Interlayer insulation layer 1114a: First interlayer insulation layer 1114b: Second interlayer insulation layer 1214: Material for interlayer insulation 1214a: Material for the first interlayer insulation layer 1214b: Material for the second interlayer insulation layer 115, 415, 515, 615, 715, 915, 1015, 1115: Leveling layer 1015a: Flattening layer disposed in the first region 1015b: Flattening layer placed in the second region 116, 1116: Bank 1317: Bag layer 618: BSM 619, 1119: Active buffer 1219: Material for active buffer 120, 420: Second substrate 121: Third substrate 130: COF 131: Base Film 132: Driver IC 140: Printed circuit board 150, 1150: Transistor 151: Gate electrode 152: Active layer 153, 1153: Source electrode 154, 1154: Drain electrode 160: LED 161: n-type layer 162: Active layer 163: p-type layer 164: p-electrode 165: n-electrode 1360: Organic light-emitting diode 1361: Anode 1362: Organic light-emitting layer 1363: Cathode 170, 570, 670, 770: Pad 171, 571, 671, 771: Gate Pad 172, 572, 672, 772: Data pad 180, 580, 680, 780, 980: Connection wiring 181, 481, 581, 681, 781, 981: First connecting wiring 182, 582, 682, 782, 982, 1182: Second connecting wiring 191: First connection pad 192: Second connection pad 1193: Third connection pad 1194: Passivation layer 1294: Material for passivation layer P1: Part 1 P2: Part 2 A1: Area 1 A2: Area 2 CNT: Contact hole US: Upper substrate DL: Data wiring ML: Intermediate wiring AD: Adhesive layer CL: Common wiring GD: Gate driver AA: Display area NA: Non-display area SPX: Subpixel T1: First thickness T2: Second thickness W1: 1st width W2: 2nd Explosion S1: 1st side S2: 2nd side SA: Rigidity zone EA: Soft Realm PR: Photoresist MP: Mask pattern

Claims

Claim 1 A display device comprising: a lower substrate having a first modulus, including a display area and a non-display area adjacent to the display area; a plurality of first substrates disposed in the display area of ​​the lower substrate; a first inorganic insulating layer disposed on each of the plurality of first substrates and having a sidewall extending upward from the plurality of first substrates; an organic insulating layer disposed on the first inorganic insulating layer, covering the sidewall of the first inorganic insulating layer and having a sidewall extending upward from the plurality of first substrates; a plurality of pixels having electronic elements disposed on each of the plurality of first substrates; and a plurality of connecting wires disposed on the lower substrate and the organic insulating layer and extending between the plurality of pixels on two adjacent first substrates among the plurality of first substrates, wherein the organic insulating layer surrounds the upper and side portions of the first inorganic insulating layer together with the plurality of first substrates, and the organic insulating layer is disposed in the area of ​​the plurality of first substrates, excluding the area between the plurality of first substrates. Claim 2 A display device according to claim 1, wherein the sidewall of the first inorganic insulating layer extends toward the upper side of the plurality of first substrates at a first angle with respect to the upper surface of the plurality of first substrates, and the sidewall of the organic insulating layer extends toward the upper side of the plurality of first substrates at a second angle with respect to the upper surface of the plurality of first substrates. Claim 3 A display device according to paragraph 2, wherein the first angle is a larger angle than the second angle. Claim 4 A display device according to claim 1, wherein the plurality of first substrates have a second modulus higher than the first modulus. Claim 5 A display device according to claim 1, wherein the modulus of the organic insulating layer is lower than the modulus of the first inorganic insulating layer. Claim 6 A display device according to claim 1, wherein the organic insulating layer has a third modulus higher than the first modulus of the lower substrate. Claim 7 A display device according to claim 1, further comprising a second inorganic insulating layer disposed on the first inorganic insulating layer, wherein the organic insulating layer covers the second inorganic insulating layer by including the sidewall of the second inorganic insulating layer. Claim 8 A display device according to claim 1, wherein a portion of the organic insulating layer extends below the region of the first inorganic insulating layer. Claim 9 A display device according to claim 1, wherein the organic insulating layer is made of an acrylic organic material. Claim 10 A display device according to claim 7, further comprising a third inorganic insulating layer disposed immediately above the second inorganic insulating layer. Claim 11 A stretchable display device comprising: a lower substrate; a plurality of first substrates disposed on the lower substrate and having subpixels defined therein; a plurality of second substrates connecting adjacent first substrates among the plurality of first substrates; a plurality of inorganic insulating layers disposed on each of the plurality of first substrates and having sidewalls exposed in the outer region of the plurality of first substrates; an organic insulating layer disposed on each of the plurality of first substrates, covering the upper surface and side surface of the plurality of inorganic insulating layers and disposed in the remaining region excluding the region between the plurality of first substrates; and a plurality of connecting wires disposed on the plurality of second substrates and the organic insulating layer, wherein the organic insulating layer surrounds the side surface of the plurality of inorganic insulating layers on each of the plurality of first substrates and is disposed on the plurality of inorganic insulating layers. Claim 12 A stretchable display device according to claim 11, wherein the plurality of inorganic insulating layers comprises: a first inorganic insulating layer on the plurality of first substrates; a second inorganic insulating layer disposed on the first inorganic insulating layer and having a width smaller than that of the first inorganic insulating layer; and a third inorganic insulating layer covering the upper surface and side surface of the second inorganic insulating layer and a portion of the upper surface of the first inorganic insulating layer. Claim 13 A stretchable display device according to claim 12, further comprising: transistors on a plurality of first substrates; a metal pattern disposed between the plurality of first substrates and the transistors, wherein the metal pattern is disposed between the first inorganic insulating layer and the first inorganic insulating layer. Claim 14 A stretchable display device according to claim 12, further comprising: transistors on a plurality of first substrates; a metal pattern disposed between the plurality of first substrates and the transistors, wherein the second inorganic insulating layer is a plurality and the metal pattern is disposed between the plurality of second inorganic insulating layers. Claim 15 A stretchable display device according to claim 11, wherein the plurality of inorganic insulating layers comprises: a first inorganic insulating layer disposed on the plurality of first substrates and comprising a first portion having a first width and a second portion disposed on the first portion having a second width smaller than the first width; a second inorganic insulating layer on the second portion; and a third inorganic insulating layer disposed to cover the upper surface and side surface of the second inorganic insulating layer and a portion of the upper surface of the first inorganic insulating layer. Claim 16 A stretchable display device according to claim 15, wherein the width of the second inorganic insulating layer is smaller than or equal to the second width. Claim 17 A lower substrate having a first modulus, comprising a display area and a non-display area adjacent to the display area; a plurality of first substrates disposed in the display area of ​​the lower substrate; a first inorganic insulating layer disposed on each of the plurality of first substrates, having a lower surface in contact with the upper surface of the plurality of first substrates and a sidewall extending upward from the lower surface at a first angle; a second inorganic insulating layer disposed on each of the plurality of first substrates, having a lower surface in contact with the upper surface of the first inorganic insulating layer and a sidewall extending upward from the lower surface at the first angle; an organic insulating layer covering the first inorganic insulating layer and the second inorganic insulating layer, in contact with the upper surface of the plurality of first substrates, the sidewall of the first inorganic insulating layer and the sidewall of the second inorganic insulating layer, and having a sidewall extending upward from the plurality of first substrates at a second angle; and a plurality of pixels disposed on each of the plurality of first substrates and having electronic elements configured to emit light. A display device comprising a plurality of connecting wires extending between a plurality of pixels on two adjacent first substrates among a plurality of first substrates, wherein the organic insulating layer is disposed on a lower substrate and an organic insulating layer, and the organic insulating layer surrounds the upper and side portions of the first inorganic insulating layer together with the plurality of first substrates, and the organic insulating layer is disposed in the area of ​​the plurality of first substrates excluding the area between the plurality of first substrates, and the first angle is an angle greater than the second angle. Claim 18 A step of forming a temporary substrate comprising a plurality of first substrates and a plurality of second substrates connecting the plurality of first substrates adjacent to each other on a lower substrate; a step of forming a transistor in each of the regions of the plurality of first substrates on the temporary substrate; a step of forming a first inorganic insulating layer having a sidewall extending upward from the plurality of first substrates on each of the plurality of first substrates; a step of forming an organic insulating layer covering the plurality of first substrates, the first inorganic insulating layer, and the lower substrate; a step of removing a portion of the organic insulating layer on the lower substrate; and a step of forming a connecting wire covering the regions of the plurality of second substrates on the temporary substrate. A method for manufacturing a display device, comprising the step of forming a plurality of second substrates from the temporary substrate, wherein the step of forming the plurality of second substrates from the temporary substrate includes the step of etching the temporary substrate, and the step of forming the first inorganic insulating layer includes the step of forming an inorganic insulating material on the temporary substrate and the step of etching the inorganic insulating material that overlaps a portion of the plurality of first substrates and the plurality of second substrates, wherein in the step of etching the inorganic insulating material, an undercut is formed in the portion of the plurality of first substrates below the first inorganic insulating layer, and in the step of forming the organic insulating layer, the step of filling the undercut with the organic insulating layer. Claim 19 A method for manufacturing a display device according to claim 18, wherein the step of forming the organic insulating layer is performed after the step of forming the temporary substrate constituting the plurality of second substrates. Claim 20 A method for manufacturing a display device according to claim 18, further comprising: a step of forming a plurality of first substrates from the temporary substrate; and a step of forming a plurality of second substrates from the temporary substrate, wherein the step of forming the plurality of first substrates is performed simultaneously with the step of forming the plurality of second substrates. Claim 21 A method for manufacturing a display device according to claim 18, wherein the lower substrate has a first modulus, and each of the plurality of first substrates has a second modulus higher than the first modulus. Claim 22 A method for manufacturing a display device according to claim 21, wherein the plurality of second substrates have a third modulus identical to the second modulus. Claim 23 A method for manufacturing a display device according to claim 18, further comprising the step of forming a light-emitting element on the organic insulating layer on the plurality of first substrates. Claim 24 A method for manufacturing a display device according to claim 18, wherein the step of forming a first inorganic insulating layer on a plurality of first substrates is performed prior to the step of forming the transistor. Claim 25 A method for manufacturing a display device according to claim 20, wherein the step of forming the plurality of first substrates on the lower substrate is performed after the step of forming the transistor. Claim 26 The method comprises the steps of: forming a temporary substrate having a plurality of rigid regions and flexible regions defined on an auxiliary substrate; forming a first inorganic insulating material on the temporary substrate; forming a second inorganic insulating material on the first inorganic insulating material; removing the second inorganic insulating material disposed in the flexible region to form a second inorganic insulating layer; forming a third inorganic insulating material on the first inorganic insulating material and the second inorganic insulating layer; removing the first inorganic insulating material and the third inorganic insulating material disposed in the flexible region to expose the flexible region to form a first inorganic insulating layer and a third inorganic insulating layer; forming an organic insulating layer to cover the upper surface and side surface of the third inorganic insulating layer; forming a plurality of connecting wires connecting adjacent rigid regions among the plurality of rigid regions on the organic insulating layer and the temporary substrate; and removing the temporary substrate disposed in a region among the flexible region other than the region where the plurality of connecting wires are disposed to form a plurality of first substrates of the plurality of rigid regions and a plurality of second substrates of the flexible region, wherein the step of forming the second inorganic insulating layer includes a portion overlapping with the second inorganic insulating layer A method for manufacturing a stretchable display device, comprising the step of removing a portion of the first inorganic insulating material excluded above, wherein the first inorganic insulating layer comprises a first portion having a first width and a second portion disposed on the first portion and having a second width smaller than the first width, overlapping with the second inorganic insulating layer, the second inorganic insulating layer disposed on the second portion, and the third inorganic insulating layer disposed to cover the upper surface and side surface of the second inorganic insulating layer and a portion of the upper surface of the first inorganic insulating layer. Claim 27 A method for manufacturing a stretchable display device according to claim 26, wherein the second inorganic insulating layer has a width smaller than the width of the first inorganic insulating layer, and the third inorganic insulating layer is arranged to cover the upper surface and side surface of the second inorganic insulating layer and a portion of the upper surface of the first inorganic insulating layer. Claim 28 A method for manufacturing a stretchable display device according to claim 26, further comprising: a step of removing the auxiliary substrate below the plurality of first substrates and the plurality of second substrates; and a step of placing a lower substrate below the plurality of first substrates and the plurality of second substrates. Claim 29 A method for manufacturing a stretchable display device according to claim 26, wherein the step of forming the plurality of first substrates and the plurality of second substrates comprises: forming a mask pattern of a material having an etching ratio smaller than that of the temporary substrate to the etchant used to etch the temporary substrate on the organic insulating layer and the plurality of connecting wires; and removing the temporary substrate that does not overlap with the organic insulating layer and the plurality of connecting wires using the mask pattern. Claim 30 A method for manufacturing a stretchable display device according to claim 29, wherein the mask pattern is made of a transparent conductive material.

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