Display device

Abstract

Embodiments disclose a display device including a plurality of first electrodes and a contact electrode disposed on a substrate, a plurality of light emitting elements disposed on the plurality of first electrodes, a first optical layer disposed between the plurality of light emitting elements, and a second electrode disposed on the plurality of light emitting elements. The second electrode includes a first region disposed on the plurality of light emitting elements and a second region extending outwardly from the first optical layer and electrically connected to the contact electrode. A plurality of signal lines connected to the plurality of first electrodes are provided, a second region of the second electrode includes protruding portions extending to at least one of regions between the plurality of signal lines, and one of the protruding portions is connected to the contact electrode.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0089616, filed on Jul. 11, 2023, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] The present disclosure relates to a display device using an inorganic light emitting diode as a light source. Background Art

[0004] Electroluminescent display devices can be roughly classified into organic light-emitting display devices in which organic light-emitting diodes (OLEDs) are provided in pixels and inorganic light-emitting display devices (hereinafter referred to as "display devices") in which inorganic light-emitting diodes (hereinafter referred to as "LEDs") are provided in pixels.

[0005] Since electroluminescent display devices display images using self-luminous elements, they do not require a separate light source such as a backlight unit, and can be implemented in a thin and diverse form.

[0006] The organic light emitting display device needs to be designed to prevent the penetration of oxygen and moisture, because the penetration of moisture and oxygen may cause oxidation between the organic light emitting layer and the electrode.

[0007] As an example of an inorganic light-emitting display device, a micro LED display device in which a micro LED is arranged in a pixel has attracted attention as a next-generation display device. The micro LED may be an inorganic LED having a size of 100 μm or less. The micro LED is manufactured by a separate semiconductor process and is transferred to a pixel position on a substrate of a display panel for a display device, so that the micro LED can be arranged in each sub-pixel for each color. Summary of the invention

[0008] Each micro LED may be connected to an anode electrode and a cathode electrode to receive power. However, there is a problem that a step occurs in the process of connecting the cathode electrode to a low potential voltage, and stress is concentrated in the region where the step occurs, thereby causing cracks.

[0009] The present disclosure provides a display panel and a display device including the display panel, which reduces resistance by removing a portion where a cathode electrode overlaps a signal line TL to reduce parasitic capacitance; and forming a cathode electrode at a portion where there is no signal line TL to increase an area of ​​the cathode electrode.

[0010] Problems or limitations to be addressed or solved by the present disclosure are not limited to those mentioned above, and other problems or limitations not mentioned will be clearly understood by those skilled in the art from the following description.

[0011] A display device according to one feature of the present disclosure includes: a plurality of first electrodes and contact electrodes disposed on a substrate; a plurality of light-emitting elements disposed on the plurality of first electrodes; a first optical layer disposed between the plurality of light-emitting elements; and a second electrode disposed on the plurality of light-emitting elements. The second electrode includes a first region disposed on the plurality of light-emitting elements and a second region extending outward from the first optical layer and electrically connected to the contact electrode. A plurality of signal lines connected to the plurality of first electrodes are provided, the second region of the second electrode includes a protruding portion extending to at least one of the regions between the plurality of signal lines, and one of the protruding portions is connected to the contact electrode.

[0012] A display device according to another feature of the present disclosure includes: a plurality of first electrodes arranged on a substrate; a plurality of light-emitting elements arranged on the plurality of first electrodes; a first optical layer arranged between the plurality of light-emitting elements; a second electrode arranged on the plurality of light-emitting elements; and a second optical layer covering the first optical layer, wherein the second electrode includes a first region arranged on the plurality of light-emitting elements and a second region extending outward from the first optical layer, the second optical layer is arranged on the second region, the second region of the second electrode includes a protruding portion extending to at least one of the regions between the plurality of signal lines, and one of the protruding portions is connected to a contact electrode for providing a voltage to the second electrode.

[0013] According to the present disclosure, low power consumption driving is possible by reducing parasitic capacitance occurring in a region where a cathode electrode and a signal line overlap each other and suppressing an increase in resistance of the cathode electrode.

[0014] The effects of the present disclosure are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those skilled in the art from the following description and the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and other objects, features and advantages of the present disclosure will become more apparent to those skilled in the art by describing in detail exemplary embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0016] Figure 1 is a diagram showing a display device according to one embodiment of the present specification.

[0017] Figure 2 yes Figure 1 An enlarged view of region A;

[0018] Figure 3 is a diagram showing a partial area of ​​a pixel;

[0019] Figure 4 is along Figure 3 A cross-sectional view taken along the center line I-I';

[0020] Figure 5 is along Figure 3 A cross-sectional view taken along line II-II';

[0021] Figure 6 is along Figure 3 A cross-sectional view taken along line III-III';

[0022] Figure 7 is a cross-sectional view showing an example in which a main light emitting element and a sub-light emitting element are electrically connected to a pixel driving circuit;

[0023] Figure 8 is a diagram showing a display device according to another embodiment of the present specification;

[0024] Fig. 9 is along Figure 8 A cross-sectional view taken along line IV-IV';

[0025] Fig.10 is a view showing a state in which stress is concentrated on a second electrode provided in a through hole;

[0026] Fig.11 yes Figure 8 A first modified example of;

[0027] Fig.12 yes Figure 8 A second modified example of;

[0028] FIG. 13A to FIG. 13F is a view showing a method for manufacturing a display device according to an embodiment of the present disclosure;

[0029] Fig.14 is a modified example of the second electrode; and

[0030] Fig.15 is along Fig.14 A cross-sectional view taken along line V-V'. DETAILED DESCRIPTION

[0031] The advantages and features of the present disclosure and the methods for realizing the same will be more clearly understood from the embodiments described below with reference to the accompanying drawings. However, the present disclosure is not limited to the following embodiments, but can be implemented in various different forms. On the contrary, the present embodiment will make the disclosure of the present disclosure complete and enable those skilled in the art to fully understand the scope of the present disclosure. The present disclosure is limited only within the scope of the appended claims.

[0032] The shapes, sizes, proportions, angles, numbers, etc. shown in the drawings for describing the embodiments of the present disclosure are merely examples, and the present disclosure is not limited thereto. Throughout this specification, similar reference numerals generally represent similar elements. In addition, when describing the present disclosure, detailed descriptions of known related technologies may be omitted to avoid unnecessarily obscuring the subject matter of the present disclosure.

[0033] Terms such as “including,” “having,” and “comprising” used herein are generally intended to allow for the addition of other components unless these terms are used with the term “only.” Any reference to the singular may include the plural unless explicitly stated otherwise.

[0034] Even if not explicitly stated, the components are interpreted as including the ordinary error range.

[0035] When describing the position or interconnection relationship between two components, such as "on", "above", "below", "beside", "connected or coupled to", "crossing", "intersecting", etc., unless "immediately" or "directly" is used, one or more other components may be inserted between them.

[0036] When describing a temporal precedence relationship, for example, "after", "after", "immediately", "before", etc., it may not be continuous on a temporal basis unless "immediately" or "directly" is used.

[0037] The terms “first”, “second”, etc. may be used to distinguish elements from one another, but the function or structure of a component is not limited by a preceding sequence number or a name of the component.

[0038] The following embodiments may be partially or entirely joined or combined with each other and may be linked and operated in various ways in technology. The embodiments may be performed independently or in association with each other.

[0039] Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0040] A display device according to an embodiment of the present specification includes a display panel and a pixel driving circuit for driving pixels on the display panel, the display panel having a display area or screen on which an image is displayed. The display area includes a pixel area where pixels are arranged. The pixel area includes a plurality of light-emitting areas. A light-emitting element is arranged in each of the light-emitting areas. The pixel driving circuit can be built into the display panel.

[0041] Figure 1 is a diagram showing a display device according to one embodiment of the present specification; Figure 2 yes Figure 1 An enlarged view of region A; Figure 3 is a diagram showing a partial area of ​​a pixel.

[0042] Reference Figure 1 and Figure 2 A display device according to an embodiment of the present specification includes a display panel 100 that visually reproduces an input image. The display panel 100 may include a display area AA that displays an image and a non-display area NA that does not display an image. In the non-display area NA, various wires and driving circuits may be installed, and a pad portion PAD connected to an integrated circuit, a printed circuit, etc. may be provided.

[0043] The plurality of light emitting elements 10 disposed in the display area AA to form the pixel PXL may be micro-sized inorganic light emitting elements. The inorganic light emitting elements may be grown on a silicon wafer and then attached to the display panel through a transfer process.

[0044] The transfer process of the light emitting element 10 may be performed for each pre-divided area. Figure 1 , the display area AA is divided into twelve transfer areas ST, but the size or the number of divisions of the transfer area is not limited thereto. The transfer process can be performed sequentially or simultaneously on the first to twelfth transfer areas ST. In the transfer areas ST, the blue light emitting elements 10, the green light emitting elements 10, and the red light emitting elements 10 can be sequentially transferred, respectively.

[0045] In the non-display area NA, a data driving circuit or a gate driving circuit may be provided, and a conductive line for providing a control signal to control these driving circuits may be provided. Here, the control signal may include various timing signals, including a clock signal, an input data enable signal, and a synchronization signal, and may be received through the pad portion PAD.

[0046] The pixel PXL can be driven by a pixel driving circuit. The pixel driving circuit can receive a driving voltage, an image signal (digital signal), a synchronization signal synchronized with the image signal, etc., and output an anode voltage and a cathode voltage of the light-emitting element 10 to drive a plurality of pixels. The driving voltage can be a high potential voltage (EVDD). The cathode voltage can be a low potential voltage (EVSS) usually applied to the pixel. The anode voltage can be a voltage corresponding to the pixel data value of the image signal. The pixel driving circuit can be arranged in the non-display area NA or in the lower part of the display area AA.

[0047] Each of the pixels PXL may include a plurality of sub-pixels, each of which has a different color. For example, the plurality of pixels may include: a red sub-pixel in which a light-emitting element 10 emitting light at a red wavelength is disposed; a green sub-pixel in which a light-emitting element 10 emitting light at a green wavelength is disposed; and a blue sub-pixel in which a light-emitting element 10 emitting light at a blue wavelength is disposed. The plurality of pixels may also include a white pixel.

[0048] Reference Figure 2 and Figure 3 , a plurality of pixels PXL may be sequentially arranged in a first direction (X-axis direction) and a second direction (Y-axis direction). In a pixel of the display area AA, a plurality of sub-pixels of the same color may be arranged. For example, each of the plurality of pixels may include: a first red sub-pixel, in which a first first light-emitting element 11a emitting light at a red wavelength is provided; a second red sub-pixel, in which a second first light-emitting element 11b emitting light at a red wavelength is provided; a first green sub-pixel, in which a first second light-emitting element 12a emitting light at a green wavelength is provided; a second green sub-pixel, in which a second second light-emitting element 12b emitting light at a green wavelength is provided; a first blue sub-pixel, in which a first third light-emitting element 13a emitting light at a blue wavelength is provided; and a second blue sub-pixel, in which a second third light-emitting element 13b emitting light at a blue wavelength is provided. The first first light-emitting element 11a, the first second light-emitting element 12a, and the first third light-emitting element 13a may be interpreted as main light-emitting elements. The second first light emitting element 11b, the second second light emitting element 12b, and the second third light emitting element 13b may be interpreted as sub-light emitting elements. The first first light emitting element 11a and the second first light emitting element 11b are collectively referred to as the first light emitting element 11, the first second light emitting element 12a and the second second light emitting element 12b are collectively referred to as the second light emitting element 12, and the first third light emitting element 13a and the second third light emitting element 13b are collectively referred to as the third light emitting element 13.

[0049] One sub-pixel includes one or more light emitting elements, and if one light emitting element becomes faulty, the brightness of another light emitting element may be increased to adjust the brightness of the sub-pixel. However, this is not necessarily limited thereto, and one sub-pixel may include only one light emitting element.

[0050] Each of the plurality of first electrodes 161 may be disposed in the lower portion of the light emitting element 10 and may be selectively connected to the plurality of signal lines TL1 to TL6 through the connection portion 161a. A high potential voltage may be applied to the pixel driving circuit through the signal lines TL1 to TL6. The signal lines TL1 to TL6 and the first electrodes 161 may be formed as an integrated electrode pattern during the electrode patterning process.

[0051] Schematically, the first signal line TL1 may be connected to the anode electrode of the first red sub-pixel, and the second signal line TL2 may be connected to the anode electrode of the second red sub-pixel. The third signal line TL3 may be connected to the anode electrode of the first green sub-pixel, and the fourth signal line TL4 may be connected to the anode electrode of the second green sub-pixel. The fifth signal line TL5 may be connected to the anode electrode of the first blue sub-pixel, and the sixth signal line TL6 may be connected to the anode electrode of the second blue sub-pixel. If one sub-pixel includes only one light-emitting element, the number of signal lines TL may be reduced by half.

[0052] The second electrode 170 may be a cathode electrode arranged in each row to apply a cathode voltage to the light emitting elements 10 arranged continuously in the first direction (X-axis direction). A plurality of second electrodes 170 may be arranged to be spaced apart from each other in the second direction (Y-axis direction). A plurality of second electrodes 170 may be connected to the cathode voltage through the contact electrode 163. Each of the plurality of second electrodes 170 may be electrically connected to the contact electrode 163. However, this is not necessarily limited thereto, and the second electrode 170 may include one electrode layer (rather than being divided into a plurality of electrodes) to serve as a common electrode.

[0053] Figure 4 is along Figure 3 Cross-sectional view taken along the center line II'. Figure 5 is along Figure 3 A cross-sectional view taken along line II-II'. Figure 6 is along Figure 3 A cross-sectional view taken along line III-III'. Figure 7 is a cross-sectional view showing an example in which two light emitting elements are connected to a pixel driving circuit.

[0054] Reference Figures 3 to 5According to an embodiment, the display device includes: a plurality of first electrodes 161 and a contact electrode 163 arranged on a substrate 110, a plurality of light emitting elements 10 arranged on the plurality of first electrodes 161, a first optical layer 141 arranged between the plurality of light emitting elements 10, and a second electrode 170 arranged on the plurality of light emitting elements 10.

[0055] The substrate 110 may be made of a flexible plastic. For example, the substrate 110 may be made of a single-layer or multi-layer substrate of a material selected from polyimide, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyether sulfone, polyarylate, polysulfone, and cycloolefin copolymer, but is not limited thereto. For example, the substrate 110 may be a ceramic substrate or a glass substrate.

[0056] The pixel driving circuit 20 may be disposed in the display area AA on the substrate 110. The pixel driving circuit 20 may include a plurality of thin film transistors using an amorphous silicon semiconductor, a polysilicon semiconductor, or an oxide semiconductor.

[0057] The pixel driving circuit 20 may include at least one driving thin film transistor, at least one switching thin film transistor, and at least one storage capacitor. When the pixel driving circuit 20 includes a plurality of thin film transistors, the pixel driving circuit 20 may be formed on the substrate 110 by a thin film transistor (TFT) manufacturing process. In an embodiment, the pixel driving circuit 20 may be a general term for a plurality of thin film transistors electrically connected to the light emitting element 10.

[0058] The pixel driving circuit 20 may be a driving driver (also referred to herein as a driver) manufactured using a metal oxide silicon field effect transistor (MOSFET) manufacturing process on a single crystal semiconductor substrate 110. The driving driver may include a plurality of pixel driving circuits for driving a plurality of sub-pixels. When the pixel driving circuit 20 is implemented as a driving driver, after an adhesive layer is provided on the substrate 110, the driving driver may be mounted on the adhesive layer through a transfer process.

[0059] A buffer layer 121 covering the pixel driving circuit 20 may be disposed on the substrate 110. The buffer layer 121 may be made of an organic insulating material such as photosensitive photoacrylic or photosensitive polyimide, but is not limited thereto.

[0060] The buffer layer 121 may be formed by, for example, silicon nitride (SiNx) or silicon oxide (SiO 2 ) is used by stacking an inorganic insulating material into multiple layers, and can be used by stacking an organic insulating material and an inorganic insulating material into multiple layers.

[0061] The insulating layer 122 may be disposed on the buffer layer 121. The insulating layer 122 may be made of an organic insulating material such as photosensitive photoacrylic or photosensitive polyimide, but is not limited thereto. The connecting wires RT1 and RT2 may be disposed on the buffer layer 121. The connecting wires RT1 and RT2 may be connected through corresponding signal lines TL1 to TL6, or may be connected to the signal lines TL1 to TL6. The connecting wires RT1 and RT2 may include a plurality of wiring patterns disposed on different layers with one or more insulating layers interposed therebetween. The wiring patterns disposed on different layers may be electrically connected via contact holes through which the insulating layers pass.

[0062] A plurality of bank patterns 130 may be provided on the insulating layer 122. At least one light emitting element 10 may be provided on each bank pattern 130. For example, a first light emitting element 11 may be provided on the first bank pattern 130, a second light emitting element 12 may be provided on the second bank pattern 130, and a third light emitting element 13 may be provided on the third bank pattern 130.

[0063] The bank pattern 130 may be made of an organic insulating material such as photosensitive acrylic or photosensitive polyimide, but is not limited thereto. The bank pattern 130 may guide a position to which the light emitting element 10 will be attached during the transfer process of the light emitting element 10. The bank pattern 130 may be omitted.

[0064] The solder pattern 162 may be disposed on the first electrode 161. The solder pattern 162 may be made of indium (In), tin (Sn), or an alloy thereof, but is not limited thereto.

[0065] A plurality of light emitting elements 10 may be mounted on the solder pattern 162, respectively. One pixel may include three colors of light emitting elements 10. The first light emitting element 11 may be a red light emitting element, the second light emitting element 12 may be a green light emitting element, and the third light emitting element 13 may be a blue light emitting element. Two light emitting elements may be mounted in each sub-pixel.

[0066] The first optical layer 141 may cover the plurality of light emitting elements 10 and the dam patterns 130. Therefore, the first optical layer 141 may cover between the plurality of light emitting elements 10 and between the plurality of dam patterns 130. The first optical layer 141 may extend in a first direction (X-axis direction) and be spaced apart in a second direction (Y-axis direction) to be separated between pixel rows.

[0067] The first optical layer 141 may include an organic insulating material in which fine metal particles such as titanium dioxide particles are dispersed. Light emitted from the plurality of light emitting elements 10 may be scattered by the fine metal particles dispersed in the first optical layer 141 to be emitted outward.

[0068] The second electrode 170 may be disposed on the plurality of light emitting elements 10. The second electrode 170 may be commonly connected to the plurality of pixels PXL. The second electrode 170 may be a thin electrode through which light is transmitted. The second electrode 170 may be a transparent electrode material such as indium tin oxide (ITO), but is not necessarily limited thereto.

[0069] The second electrode 170 may extend in the first direction (X-axis direction) and be spaced apart in the second direction (Y-axis direction). The second electrode 170 may include: a first region 171 disposed on the top surface of the light emitting element 10 and the top surface of the first optical layer 141, a second region 172 contacting and electrically connected to the contact electrode 163, and a third region 173 disposed on the side of the first optical layer 141 and connecting the first region 171 and the second region 172.

[0070] On a plane, each of the plurality of second electrodes 170 may overlap the first optical layer 141 , and the second region 172 may cover a plane outside the first optical layer 141 .

[0071] The second optical layer 142 may be an organic insulating material surrounding the first optical layer 141. The second optical layer 142 may be disposed on the insulating layer 122 together with the first optical layer 141. The first optical layer 141 and the second optical layer 142 may include the same material (e.g., siloxane). For example, the first optical layer 141 may be siloxane containing titanium oxide (TiOx), and the second optical layer 142 may be siloxane not containing titanium oxide (TiOx). However, this is not necessarily limited thereto, and the first optical layer 141 and the second optical layer 142 may be formed of the same material, or may be formed of different materials.

[0072] According to an embodiment, since the second region 172 of the second electrode 170 is connected to the contact electrode 163 in an overall flat state, excessive stress is not concentrated at the point of connection with the contact electrode 163. Therefore, cracks in the second electrode 170 may be effectively prevented.

[0073] The second optical layer 142 may cover the second region 172 and the third region 173 of the second electrode 170. The top surface of the second optical layer 142 and the top surface of the first region 171 of the second electrode 170 may be coplanar. In other words, the first optical layer 141 and the second optical layer 142 may function as a planarization layer. Therefore, the pattern of the black matrix 190 may be easily formed on the first optical layer 141 and the second optical layer 142 because there is no step on the surface where the black matrix 190 is formed. However, this is not necessarily limited thereto, and the top surfaces of the second optical layer 142 and the second electrode 170 may have different heights.

[0074] The black matrix 190 may be an organic insulating material to which a black pigment is added. Under the black matrix 190, the second electrode 170 may be in contact with the contact electrode 163. Transmission holes 191 may be formed between patterns of the black matrix 190, and light emitted from the light emitting element 10 is emitted outward through the transmission holes 191. The black matrix 190 may improve the problem of mixing light emitted from adjacent light emitting elements 10 by the first optical layer 141.

[0075] The cover layer 180 may be an organic insulating material for covering the black matrix 190 and the second electrode 170. Figure 3 In the figure, the configuration of the black matrix 190 and the cover layer 180 is omitted.

[0076] The contact electrode 163 is electrically connected to the first connection line RT1 disposed on the lower portion thereof, and the first connection line RT1 may be connected to the pixel driving circuit 20. Therefore, a cathode voltage may be applied to the second electrode 170 through the contact electrode 163. The first electrode 161 may be electrically connected to the second connection line RT2. This will be described later.

[0077] Reference Figure 5 , the contact electrode 163 and the signal lines TL1 to TL6 may be disposed on the same plane. The pixel driving circuit 20 may be disposed on the lower portion of the contact electrode 163 and the signal lines TL1 to TL6. When the pixel driving circuit 20 is a driving driver, a plurality of driving drivers may be disposed in the display panel.

[0078] The passivation layer 133 may expose the contact electrode 163 so that the contact electrode 163 and the second electrode 170 are electrically connected. In addition, the passivation layer 133 may insulate the signal lines TL2 to TL5 from the second electrode 170 .

[0079] Reference Figure 6 The connection portion 161 a of the first electrode 161 extends to one side surface 131 of the bank pattern 130 and is electrically connected to a connection line RT2 disposed on the insulating layer 122 .

[0080] The first electrode 161, the connection portion 161a, the signal line TL and / or the connection lines RT1 and RT2 may include a single layer or multiple layers of a metal layer selected from titanium (Ti), molybdenum (Mo) and aluminum (Al). The first electrode 161, the connection portion 161a, the signal line TL and / or the connection lines RT1 and RT2 may be formed into a multilayer structure including a first layer ML1, a second layer ML2, a third layer ML3 and a fourth layer ML4.

[0081] The first layer ML1 and the third layer ML3 may include titanium (Ti) or molybdenum (Mo). The second layer ML2 may include aluminum (Al). The fourth layer ML4 may include a transparent conductive oxide layer, such as indium tin oxide (ITO) or indium zinc oxide (IZO), which has good adhesion to the solder pattern 162, corrosion resistance, and acid resistance.

[0082] The first layer ML1 , the second layer ML2 , the third layer ML3 , and the fourth layer ML4 may be sequentially deposited and then patterned by performing a photolithography process and an etching process.

[0083] The passivation layer 133 may be disposed on the first electrode 161 and the signal line TL, and may include an opening hole 133 a exposing the solder pattern 162 .

[0084] The light emitting element 10 may include a first conductive type semiconductor layer 10-1, an active layer 10-2 disposed on the first conductive type semiconductor layer 10-1, and a second conductive type semiconductor layer 10-3 disposed on the active layer 10-2. A first driving electrode 15 may be disposed on a lower portion of the first conductive type semiconductor layer 10-1, and a second driving electrode 14 may be disposed on an upper portion of the second conductive type semiconductor layer 10-3.

[0085] The light emitting element 10 can be formed on a silicon wafer using a method such as metal organic chemical vapor deposition (MOCVD), chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), molecular beam epitaxy (MBE), hydride vapor phase epitaxy (HVPE), sputtering, etc.

[0086] The first conductive type semiconductor layer 10-1 may be implemented as a compound semiconductor such as a group III-V, group II-VI, etc., and may be doped with a first dopant. The first conductive type semiconductor layer 10-1 may be made of a compound semiconductor having a composition formula of Al x1 In y1 Ga (1-x1-y1) The first conductive semiconductor layer 10-1 may be formed of any one or more of semiconductor materials of N (0≤x1≤1, 0≤y1≤1, O≤x1+y1≤1), InAlGaN, AlGaAs, GaP, GaAs, and AlGaInP, but is not limited thereto. When the first dopant is an n-type dopant such as Si, Ge, Sn, Se, Te, etc., the first conductive semiconductor layer 10-1 may be an n-type nitride semiconductor layer. However, when the first dopant is a p-type dopant, the first conductive semiconductor layer 10-1 may be a p-type nitride semiconductor layer.

[0087] The active layer 10-2 is a layer where electrons (or holes) injected through the first conductive semiconductor layer 10-1 meet holes (or electrons) injected through the second conductive semiconductor layer 10-3. The active layer 10-2 can generate light that transitions to a lower energy level and has a corresponding wavelength as the electrons and holes recombine.

[0088] The active layer 10-2 may have any one of a single well structure, a multi-well structure, a single quantum well structure, a multi-quantum well (MQW) structure, a quantum dot structure, or a quantum wire structure, and the structure of the active layer 10-2 is not limited thereto. The active layer 10-2 may generate light in a visible light wavelength band. Schematically, the active layer 10-2 may output light in any one wavelength band of a blue wavelength band, a green wavelength band, and a red wavelength band.

[0089] The second conductive type semiconductor layer 10-3 may be disposed on the active layer 10-2. The second conductive type semiconductor layer 10-3 may be implemented as a compound semiconductor such as a group III-V, group II-VI, etc., and the second conductive type semiconductor layer 10-3 may be doped with a second dopant. The second conductive type semiconductor layer 10-3 may be composed of a semiconductor having a composition formula of In x2 Al y2 Ga1 -x-2+y2 The second conductive semiconductor layer 10-3 may be formed of a semiconductor material selected from the group consisting of AlInN, AlGaAs, GaP, GaAs, GaAsP and AlGaInP. When the second dopant is a p-type dopant such as Mg, Zn, Ca, Sr, Ba, etc., the second conductive semiconductor layer 10-3 doped with the second dopant may be a p-type semiconductor layer. When the second dopant is an n-type dopant, the second conductive semiconductor layer 10-3 may be an n-type nitride semiconductor layer.

[0090] A reflective layer 16 may be provided on the side surface and the lower portion of the light emitting element 10. The reflective layer 16 may have a structure in which a reflective material is dispersed in a resin layer, but is not necessarily limited thereto. Schematically, the reflective layer 16 may be manufactured as a reflector of various structures. The light emitted from the active layer 10-2 may be reflected upward by the reflective layer 16 to improve light extraction efficiency.

[0091] Although the embodiment is described as a vertical structure in which the driving electrodes 14 and 15 are provided on the upper and lower portions of the light emitting structure, the light emitting element may have a lateral structure or a flip chip structure in addition to the vertical structure.

[0092] Reference Figure 7, a main light emitting element 12a and a sub light emitting element 12b of a sub-pixel may be disposed on the bank pattern 130. The second light emitting element 12 will be schematically described. The first first electrode 161-1 connected to the main light emitting element 12a may extend to one side surface of the bank pattern 130 to be electrically connected to the first second connection line RT21 disposed on the lower portion thereof. The second first electrode 161-2 connected to the sub light emitting element 12b may extend to the other side surface of the bank pattern 130 to be electrically connected to the second second connection line RT22 disposed on the lower portion thereof.

[0093] The pixel driving circuit 20 can apply an anode voltage to the main light emitting element 12a through the first second connection line RT21, and can apply an anode voltage to the sub light emitting element 12b through the second second connection line RT22. The pixel driving circuit 20 can apply a cathode voltage to the main light emitting element 12a and the sub light emitting element 12b through the first connection line RT1 and the second electrode 170.

[0094] The pixel driving circuit 20 can adjust the brightness by driving only the main light emitting element 12a, or can adjust the brightness by driving both the main light emitting element 12a and the sub-light emitting element 12b. If the main light emitting element 12a becomes dark, the brightness can be adjusted by driving only the sub-light emitting element 12b.

[0095] Figure 8 is a diagram showing a display device according to another embodiment of the present specification. Fig. 9 is along Figure 8 A cross-sectional view taken along line IV-IV'. Fig.10 is a view showing a state in which stress is concentrated on a second electrode provided in a through hole;

[0096] Reference Figure 8 and Fig. 9 , the second electrode 170 may be electrically connected to the contact electrode 163 via a contact hole TH1 formed in the second optical layer 142. The second optical layer 142 may include a contact hole TH1 exposing the contact electrode 163. The second electrode 170 may be inserted into the contact hole TH1 of the second optical layer 142 and may contact an upper surface of the contact electrode 163. The contact hole TH1 may be formed in an outer region of the pixel.

[0097] Reference Fig.10 Since the second electrode 170 is relatively thin and the contact hole TH1 is formed deeper than the thickness of the second electrode 170, a stress concentration region BP1 may occur in a portion 170a of the second electrode 170 formed on a side of the contact hole TH1. Therefore, cracks may occur in a portion 170a of the second electrode 170 formed around the contact hole TH1.

[0098] However, as referenced Figure 4 As described, when the second electrode 170 is connected to the contact electrode 163 in a flat and extended state instead of forming the contact hole TH1, it is possible to prevent excessive stress from being applied to the second electrode 170. Therefore, it is possible to prevent cracks from occurring in the second electrode 170.

[0099] Fig.11 yes Figure 8 First modified example. Fig.12 yes Figure 8 Second modified example.

[0100] Reference Fig.11 , the contact hole TH1 may be filled with a separate through electrode 164. The through electrode 164 may include various conductive materials that may be filled in the contact hole TH1. Since the second electrode 170 is disposed on the through electrode 164, the second electrode 170 is formed to be relatively flat, thereby preventing excessive stress from occurring.

[0101] Reference Fig.12 , the through electrode 164 may not completely fill the contact hole TH1, but only fill it to a certain height. According to such a structure, the depth of the second electrode 170 inserted into the contact hole TH1 can be relatively low. Therefore, the step of the second electrode 170 can be reduced, thereby reducing the probability of cracks.

[0102] FIG. 13A to FIG. 13F is a view illustrating a method for manufacturing a display device according to an embodiment of the present disclosure.

[0103] Reference Fig.13A , a pixel driving circuit 20 may be formed on the substrate 110, and a buffer layer 121 may be formed on the pixel driving circuit 20. The pixel driving circuit 20 may receive a driving voltage, an image signal (digital signal), a synchronization signal synchronized with the image signal, etc., and output an anode voltage and a cathode voltage of the light emitting element 10, thereby driving a plurality of pixels. The pixel driving circuit 20 may be disposed in the non-display area NA or below the display area AA.

[0104] Subsequently, connection lines RT1, RT21, and RT22 may be formed on the buffer layer 121, and then the insulating layer 122 may be formed. The connection lines RT1, RT21, and RT22 may be electrically connected to the pixel driving circuit 20 by passing through the buffer layer 121. In order to drive each pixel, the number of connection lines RT1, RT21, and RT22 and the stacking number of the connection lines RT1, RT21, and RT22 may be changed. Therefore, the stacking number of the connection lines RT1, RT21, and RT22 and the insulating layer 122 may be two or more layers.

[0105] A bank pattern 130 may be formed on the insulating layer 122 to select a position where the light emitting element 10 is transferred. The bank pattern 130 may be made of an organic insulating material such as photosensitive photoacrylic or photosensitive polyimide, but is not limited thereto. The bank pattern 130 may guide a position where the light emitting element 10 is to be attached during the transfer process of the light emitting element 10. However, the bank pattern 130 may be omitted.

[0106] An electrode material may be applied on the insulating layer 122 and the bank pattern 130, and then patterned to form a plurality of first electrodes 161 and a contact electrode 163. The plurality of first electrodes 161 are regions where the light emitting element 10 is disposed, and the contact electrode 163 is a region electrically connected to the second electrode 170. Subsequently, a passivation layer 133 may be formed in an electrode region including a region where the plurality of first electrodes 161 and the contact electrode 163 are formed.

[0107] A solder pattern 162 may be formed on the first electrode 161. The solder pattern 162 may be made of indium (In), tin (Sn), or an alloy thereof, but is not limited thereto.

[0108] Reference Fig. 13B , a plurality of light emitting elements 10 may be transferred to the solder pattern 162, respectively. One pixel may include three colors of light emitting elements 10. The first light emitting element may be a red light emitting element, the second light emitting element may be a green light emitting element, and the third light emitting element may be a blue light emitting element. Two light emitting elements may be installed in each sub-pixel.

[0109] The transfer method is not particularly limited. That is, the light emitting element 10 grown on the semiconductor growth substrate may be first transferred to the transfer substrate and then transferred to the panel substrate, or the light emitting element 10 grown on the semiconductor growth substrate may be directly transferred to the panel substrate.

[0110] Reference Fig. 13C and Fig.13D , the first optical layer 141 may be completely formed on the substrate 110 and then patterned so that the top surface of the light emitting element 10 and the contact electrode 163 are exposed. The remaining portion of the first optical layer 141 may be removed except for a region sufficient to cover the light emitting element 10 and the bank pattern 130. Therefore, the first optical layer 141 may cover between the plurality of light emitting elements 10 and between the plurality of bank patterns 130. At this time, the top surface of the light emitting element 10 may be exposed on the top of the first optical layer 141.

[0111] The first optical layer 141 may include an organic insulating material in which fine metal particles such as titanium dioxide particles are dispersed. Light emitted from the light emitting element 10 may be scattered by the fine metal particles dispersed in the first optical layer 141 and then emitted.

[0112] Reference Fig.13E , a second electrode 170 may be formed on a plurality of light emitting elements 10. The second electrode 170 may be generally connected to all pixels. The second electrode 170 may be a thin metal electrode that transmits light. The second electrode 170 may be a transparent electrode material such as indium tin oxide (ITO), but is not necessarily limited thereto.

[0113] The second electrode 170 may be divided to be disposed in each pixel row by patterning. The plurality of divided second electrodes 170 may be electrically connected to the contact electrode 163 .

[0114] Reference Fig.13F , the second optical layer 142 may be formed to surround the first optical layer 141. In this process, the second optical layer 142 may cover a portion of the second electrode 170 connected to the contact electrode 163.

[0115] The second optical layer 142 may be disposed on the insulating layer 122 together with the first optical layer 141. The first optical layer 141 and the second optical layer 142 may include the same material (e.g., siloxane). For example, the first optical layer 141 may be siloxane containing titanium oxide (TiOx), and the second optical layer 142 may be siloxane not containing titanium oxide (TiOx).

[0116] Subsequently, a black matrix 190 may be formed on the second electrode 170 and the second optical layer 142 , and a capping layer 180 may be formed on the black matrix 190 .

[0117] Fig.14 is a modified example of the second electrode. Fig.15 is along Fig.14 A cross-sectional view taken along line V-V'.

[0118] Reference Fig.14 , a portion of the second electrode 170 is removed so as not to overlap with the signal line TL on a plane, so that at least one concave portion 1701 and at least one convex portion 1702 may be alternately formed. Any one of such convex portions 1702 may be connected to the contact electrode 163. In addition, a plurality of concave portions 1701 and a plurality of convex portions 1702 may be alternately formed. Any one of such convex portions 1702 may be connected to the contact electrode 163. Fig.14 An embodiment is shown in which a plurality of convex portions 1702 are formed and one of the convex portions 1702 is connected to the contact electrode 163. However, in addition to the convex portion 1702 connected to the contact electrode 163, the remaining convex portions 1702 may be selectively formed.

[0119] Reference Figure 5, only the passivation layer 133 having a small thickness is disposed between the signal line TL and the second electrode 170, so that the capacitance is formed to be higher than that of other regions, thereby causing interference with the driving signal. Fig.14 and Fig.15 , when the second region (ie, Figure 3 When the portion overlapping with the signal line TL is removed from the second region 172 (see FIG. 1 ), the parasitic capacitance between the second electrode 170 and the signal line TL can be reduced. In addition, the second electrode 170 can be formed in the second region 172 (see FIG. 1 ). Figure 3 ) in a portion where there is no signal line TL, thereby increasing the area of ​​the second electrode 170 and reducing the resistance.

[0120] The display device according to the embodiments of the present disclosure can be applied to mobile devices, video phones, smart watches, watch phones, wearable devices, foldable devices, rollable devices, bendable devices, flexible devices, bending devices, sliding devices, variable devices, electronic notebooks, electronic books, portable multimedia players (PMP), personal digital assistants (PDA), MP3 players, mobile medical devices, desktop personal computers (PC), laptop personal computers (PC), netbook computers, workstations, navigation, vehicle display devices, theater display devices, televisions, wallpaper devices, sign devices, game devices, notebook computers, monitors, cameras, video cameras, home appliances, etc. In addition, the display device according to one or more embodiments of the present disclosure can be applied to organic light emitting lighting devices or inorganic light emitting lighting devices.

[0121] According to one or more embodiments of the present disclosure, a display device may be described as follows.

[0122] According to one or more embodiments of the present disclosure, a display device may include: a plurality of first electrodes and contact electrodes arranged on a substrate; a plurality of light-emitting elements arranged on the plurality of first electrodes; a first optical layer arranged between the plurality of light-emitting elements; and a second electrode arranged on the plurality of light-emitting elements, wherein the second electrode includes a first region arranged on the plurality of light-emitting elements and a second region extending outward from the first optical layer and electrically connected to the contact electrode, a plurality of signal lines connected to the plurality of first electrodes are provided, the second region of the second electrode includes a protruding portion extending to at least one of the regions between the plurality of signal lines, and one of the protruding portions is connected to the contact electrode.

[0123] The display device may further include a second optical layer covering the second region of the second electrode.

[0124] The first optical layer and the second optical layer may be made of different materials.

[0125] The first optical layer may include light scattering particles.

[0126] A top surface of the second optical layer and a top surface of the first region of the second electrode may be coplanar.

[0127] A pattern of a black matrix may be formed on the first optical layer and the second optical layer.

[0128] The display device may further include a plurality of bank patterns disposed between the substrate and the plurality of first electrodes.

[0129] A plurality of signal lines may extend between the plurality of bank patterns.

[0130] The contact electrodes are provided between the plurality of signal lines.

[0131] The second electrode may be divided into a plurality to be disposed in each pixel row, and the plurality of divided second electrodes may be electrically connected to the contact electrodes, respectively.

[0132] The second electrode may include a third region extending to a side of the first optical layer and connecting the first region and the second region.

[0133] The display device may further include: an insulating layer disposed on the substrate; a plurality of connection lines disposed between the substrate and the insulating layer; and a pixel driving circuit connected to the plurality of connection lines, the plurality of connection lines may be electrically connected to the plurality of first electrodes and the contact electrodes.

[0134] The plurality of light emitting elements may be inorganic light emitting diodes.

[0135] The pixel driving circuit is the driver.

[0136] According to one or more embodiments of the present disclosure, a display device may include: a plurality of first electrodes arranged on a substrate; a plurality of light-emitting elements arranged on the plurality of first electrodes; a first optical layer arranged between the plurality of light-emitting elements; a second electrode arranged on the plurality of light-emitting elements; and a second optical layer covering the first optical layer, the second electrode may include a first region arranged on the plurality of light-emitting elements and a second region extending outward from the first optical layer, and the second optical layer may be arranged on the second region.

[0137] The first optical layer and the second optical layer may be made of different materials.

[0138] The first optical layer may include light scattering particles.

[0139] The display device may further include a plurality of bank patterns disposed between the substrate and the plurality of first electrodes.

[0140] The display device may further include a plurality of signal lines extending between the plurality of bank patterns and connected to the plurality of first electrodes.

[0141] The display device may further include a contact electrode disposed on the substrate and electrically connected to the second electrode, and the contact electrode may be disposed between the plurality of signal lines.

[0142] The second electrode may be divided into a plurality to be disposed in each pixel row, and the plurality of divided second electrodes may be electrically connected to the contact electrodes, respectively.

[0143] The display device may further include: an insulating layer disposed on the substrate; a plurality of connection lines disposed between the substrate and the insulating layer; and a pixel driving circuit connected to the plurality of connection lines, the plurality of connection lines may be electrically connected to the plurality of first electrodes and the contact electrodes.

[0144] The above-mentioned objects to be achieved by the present disclosure, means for achieving the objects, and effects of the present disclosure do not specify essential features of the claims, and therefore, the scope of the claims is not limited to the disclosure of the present disclosure.

[0145] Although the embodiments of the present disclosure have been described in more detail with reference to the accompanying drawings, the present disclosure is not limited thereto and can be implemented in many different forms without departing from the technical concept of the present disclosure. Therefore, the embodiments disclosed in the present disclosure are provided for illustrative purposes only and are not intended to limit the technical concept of the present disclosure. The scope of the technical concept of the present disclosure is not limited thereto. Therefore, it should be understood that the above embodiments are illustrative in all aspects and do not limit the present disclosure.

Claims

1. A display device, comprising: A plurality of first electrodes and contact electrodes are disposed on the substrate; a plurality of light emitting elements disposed on the plurality of first electrodes; a first optical layer disposed between the plurality of light emitting elements; as well as A second electrode disposed on the plurality of light emitting elements, The second electrode includes a first region disposed on the plurality of light emitting elements and a second region extending outward from the first optical layer and electrically connected to the contact electrode. A plurality of signal lines connected to the plurality of first electrodes are provided, The second region of the second electrode includes a protruding portion extending to at least one of the regions between the plurality of signal lines, and One of the protruding portions is connected to the contact electrode.

2. The display device according to claim 1, further comprising: A second optical layer covers the second region of the second electrode.

3. The display device according to claim 2, wherein: The first optical layer and the second optical layer are made of different materials.

4. The display device according to claim 3, wherein: The first optical layer includes light scattering particles.

5. The display device according to claim 2, wherein: A top surface of the second optical layer and a top surface of the first region of the second electrode are coplanar.

6. The display device according to claim 5, wherein: A black matrix pattern is formed on the first optical layer and the second optical layer.

7. The display device according to claim 1, further comprising: A plurality of bank patterns are disposed between the substrate and the plurality of first electrodes.

8. The display device according to claim 7, wherein: The plurality of signal lines extend between the plurality of bank patterns.

9. The display device according to claim 7, wherein: The contact electrode is disposed between the plurality of signal lines.

10. The display device according to claim 2, wherein: The second electrode is divided into a plurality of electrodes so as to be arranged in each pixel row, and A plurality of divided second electrodes are electrically connected to the contact electrodes, respectively.

11. The display device according to claim 1, wherein: The second electrode includes a third region extending to a side of the first optical layer and connecting the first region and the second region.

12. The display device according to claim 1, further comprising: An insulating layer is provided on the substrate, A plurality of connecting lines disposed between the substrate and the insulating layer; as well as a pixel driving circuit connected to the plurality of connection lines, The plurality of connection lines are electrically connected to the plurality of first electrodes and the contact electrode.

13. The display device according to claim 1, wherein: The plurality of light emitting elements are inorganic light emitting diodes.

14. The display device according to claim 12, wherein: The pixel driving circuit is a driver.

15. A display device comprising: A plurality of first electrodes are disposed on the substrate; a plurality of light emitting elements disposed on the plurality of first electrodes; a first optical layer disposed between the plurality of light emitting elements; a second electrode disposed on the plurality of light emitting elements; as well as a second optical layer covering the first optical layer, The second electrode includes a first region disposed on the plurality of light emitting elements and a second region extending outward from the first optical layer. The second optical layer is disposed on the second area, The second region of the second electrode includes a protruding portion extending to at least one of the regions between the plurality of signal lines, and One of the protruding portions is connected to a contact electrode.

16. The display device according to claim 15, wherein: The first optical layer and the second optical layer are made of different materials.

17. The display device according to claim 16, wherein: The first optical layer includes light scattering particles.

18. The display device according to claim 15, further comprising: A plurality of bank patterns are disposed between the substrate and the plurality of first electrodes.

19. The display device according to claim 18, further comprising: The plurality of signal lines extend between the plurality of bank patterns and are connected to the plurality of first electrodes.

20. The display device according to claim 19, further comprising: the contact electrode disposed on the substrate and electrically connected to the second electrode, Wherein, the contact electrode is arranged between the plurality of signal lines.

21. The display device according to claim 20, wherein: The second electrode is divided into a plurality of electrodes so as to be arranged in each pixel row, and A plurality of divided second electrodes are electrically connected to the contact electrodes, respectively.

22. The display device according to claim 20, further comprising: An insulating layer is provided on the substrate, A plurality of connecting lines disposed between the substrate and the insulating layer; as well as a pixel driving circuit connected to the plurality of connection lines, The plurality of connection lines are electrically connected to the plurality of first electrodes and the contact electrode.

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