Display device and method of manufacturing same

Abstract

Disclosed is a display device. The display device includes: a substrate; the first electrode and the second electrode are arranged on the substrate; a bank layer disposed on the first electrode and the second electrode, the bank layer including an opening; the micro light emitting diode is arranged in the opening of the bank layer; the high refractive index layer is arranged on the micro light emitting diodes; an overcoat layer disposed on the high refractive index layer and having a lower refractive index than the high refractive index layer; and a fixing member disposed between the high refractive index layer and the bank layer.

Description

Technical Field

[0001] The present disclosure relates to a display device, and more particularly, to a display device and a manufacturing method thereof that can simplify a manufacturing process. Background Art

[0002] In flat panel displays, it is common to use a liquid crystal display device (LCD) or an organic light emitting display device (OLED).

[0003] Compared with a liquid crystal display device, an organic light emitting display device has advantages such as improved luminous efficiency, fast response speed, and wide viewing angle. However, the organic light emitting display device still has low luminous efficiency and includes organic materials, so it is vulnerable to foreign substances such as moisture. Therefore, the reliability and lifespan of the organic light emitting display device may deteriorate.

[0004] Recently, a micro light emitting diode display device as an inorganic light emitting display device has been proposed.

[0005] A micro light emitting diode display device can implement an image by arranging inorganic light emitting diodes having a size of approximately 100 micrometers (μm) or less in each pixel. In the micro light emitting diode, a process of transferring the micro light emitting diode grown on a single crystal substrate to an array substrate of the display device is performed using a stamp or the like.

[0006] The description provided in the background section should not be considered prior art merely because it is mentioned in the background section or is related to the background section. The background section may include information describing one or more aspects of the subject technology. Summary of the Invention

[0007] In order to improve light extraction efficiency and adjust the viewing angle of the display device, in some embodiments, a geometric pattern such as a lens is provided on the micro light emitting diode.

[0008] In some solutions, after performing the process of transferring the micro light emitting diode and the process of connecting the electrodes, a lens is formed by applying a material for forming the lens and performing an exposure process. The inventors recognized that due to performing the exposure process for forming the lens, there are disadvantages that the manufacturing process of the display device may be complicated and the manufacturing cost may increase.

[0009] The inventors of the present disclosure have invented a manufacturing method of a display device that can transfer a micro light emitting diode and a lens simultaneously.

[0010] The present disclosure according to an embodiment provides a display device and a manufacturing method thereof that can simplify its manufacturing process.

[0011] Aspects and technical features according to the present disclosure are not limited to the above aspects and technical features, and those skilled in the art can clearly understand from the following description and can more clearly understand other aspects and features not mentioned above from the embodiments described herein.

[0012] A display device according to an embodiment of the present disclosure may include: a substrate; a planarization layer disposed on the substrate; a first electrode and a second electrode disposed on the planarization layer; an insulating layer disposed on the first electrode and the second electrode, the insulating layer including an opening; a micro light-emitting diode disposed in the opening of the insulating layer; a lens disposed on the micro light-emitting diode; and an adhesive layer disposed between the lens and the insulating layer.

[0013] A method of manufacturing a display device according to an embodiment of the present disclosure may include: forming a stamper having a recess; forming a lens in the recess; first transferring a micro light-emitting diode to the lens; preparing an array substrate coated with an adhesive layer on each sub-pixel; and then transferring the lens and the micro light-emitting diode together to the array substrate.

[0014] Detailed descriptions of other embodiments are included in the following description and drawings.

[0015] Additional features and aspects will be partly set forth in the following description, and partly will be apparent from the following description, or may be learned by practice of the inventive concepts provided herein. Other features and aspects of the inventive concepts may be realized and obtained by structures specifically pointed out or derivable from in the written description, its claims, and the drawings.

[0016] According to an embodiment of the present disclosure, the lens and the micro light-emitting diode may be simultaneously mounted on the array panel through one transfer process. Therefore, different from a conventional manufacturing process of forming a lens by performing a photolithography process after a process of coating a material for forming the lens, the photolithography process may be eliminated in the present disclosure, thereby simplifying the manufacturing method of the display device and reducing the manufacturing cost.

[0017] Since a lens having a curved upper surface is disposed in each micro light-emitting diode, the light extraction efficiency of the micro light-emitting diode may be improved. Therefore, the display device may be operated with low power.

[0018] In addition to the above effects, specific effects of the present disclosure will be described together with the following detailed description for implementing the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a plan view showing a display device according to an exemplary embodiment of the present disclosure;

[0020] Figure 2 is alongFigure 1 Cross-sectional view of a 2-2 cut;

[0021] Figure 3 is a plan view showing a display device according to another exemplary embodiment of the present disclosure;

[0022] Figure 4 is along Figure 3 Cross-sectional view of a 4-4 cut;

[0023] Figure 5 is a plan view showing a display device according to other exemplary embodiments of the present disclosure;

[0024] Figure 6 is along Figure 5 Cross-sectional view of a 6-6 cut;

[0025] Figures 7a to 7f is a view for describing a method of manufacturing a display device according to an exemplary embodiment of the present disclosure; and

[0026] Figures 8a to 8c is a view for describing a method of manufacturing a display device according to an exemplary embodiment of the present disclosure. Detailed Description of the Invention

[0027] The above-mentioned technical benefits, features, advantages, and methods for achieving them will be described in detail later with reference to the accompanying drawings. Therefore, those skilled in the art to which the present disclosure pertains will be able to easily implement the technical idea of the present disclosure. When describing the present disclosure, if it is determined that a detailed description of known technologies related to the present disclosure may unnecessarily obscure the subject matter of the present disclosure, such detailed description will be omitted.

[0028] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to denote the same or similar components. The present disclosure should be construed as extending to any variations, equivalents, and alternatives other than those specifically set forth in the drawings. The terms of each element used in the following description are terms defined in consideration of the functions obtained in the present disclosure. Therefore, these terms do not limit the technical elements of the present disclosure. In addition, the defined terms of each element may be referred to as other terms in the art. The singular representation may include the plural representation unless it indicates a clearly different meaning from the context. Terms such as "including", "comprising", "containing", "consisting of", or "having" are used herein, and it should be understood that they are intended to indicate the presence of several components, functions, or steps disclosed in the specification, and it should also be understood that more or fewer components, functions, or steps may also be utilized.

[0029] When understanding a component, the component should be understood as including an appropriate error range even if there is no separate explicit description of such an error range.

[0030] It should be understood that when an element is referred to as being "connected" or "adhered to" another element, the element can be directly connected or adhered to the other element, or there may also be an intermediate element. In contrast, when an element is referred to as being "directly connected" to another element, there is no intermediate element.

[0031] When describing the temporal relationship between two events (e.g., temporal precedence relationships such as "after", "subsequently", "next", "before", etc.), unless more restrictive terms such as "exactly", "immediately", or "right" are used, another event may occur in between.

[0032] It should be understood that although terms such as first and second may be used herein to describe various elements, these elements should not be limited by these terms. These terms are generally only used to distinguish one element from another.

[0033] The features of various embodiments can be partially or fully combined with each other, and various connections and drivings are possible. In addition, the embodiments can be implemented independently or in a related relationship.

[0034] Hereinafter, a display device according to an embodiment of the present disclosure will be described with reference to the accompanying drawings.

[0035] Figure 1 is a plan view showing a display device according to an embodiment of the present disclosure. Figure 2 is along Figure 1 a sectional view taken along line 2-2 of Figure 1 and Figure 2 show a region corresponding to one sub-pixel of the display device 100.

[0036] Referring to Figure 1 and Figure 2 , the display device 100 according to an embodiment may include an array panel DPS; a micro light-emitting diode ED1 mounted on the array panel DPS; and a lens LS disposed on the micro light-emitting diode ED1.

[0037] The array panel DPS may include a substrate 110, a thin film transistor 120 disposed on the substrate 110, a first planarization layer 129 covering the thin film transistor 120; a first electrode 131 and a second electrode 133 disposed on the first planarization layer 129; and an insulating layer 135 having an opening OP.

[0038] The substrate 110 can be made of glass or plastic. For example, as a plastic substrate, polyimide (PI), polyethylene terephthalate (PET), acrylonitrile-butadiene-styrene copolymer (ABS), polymethyl methacrylate (PMMA), polyethylene naphthalate (PEN), polycarbonate (PC), polyethersulfone (PES), polyarylate (PAR), polysulfone (PSF), cycloolefin copolymer (COC), triacetyl cellulose (TAC) film, polyvinyl alcohol (PVA) film, and polystyrene (PS) can be used, but are not limited thereto.

[0039] The thin film transistor 120 can include a semiconductor layer 121 formed on the substrate 110; a gate insulating layer 122 and a gate electrode 123 provided on the semiconductor layer 121; and a drain (or source) electrode 124 and a source (or drain) electrode 125.

[0040] The gate electrode 123 can be a single layer or multiple layers made of Cr, Mo, Ni, Ta, Cu, Ti, Al, Ni, etc. or their alloys, or can be a conductive compound such as a metal nitride or other conductive materials such as doped polysilicon. The gate insulating layer 122 can be a single layer or multiple layers made of an inorganic insulating material such as silicon oxide, silicon nitride, or silicon oxynitride. The semiconductor layer 121 can be made of a silicon semiconductor such as amorphous silicon or polysilicon, or it can be made of a metal oxide such as zinc (Zn), indium (In), gallium (Ga), tin (Sn), and titanium (Ti) or a composition of a metal and its oxide such as zinc (Zn), indium (In), gallium (Ga), tin (Sn), or titanium (Ti). Specifically, the oxide semiconductor can include zinc oxide (ZnO), zinc tin oxide (ZTO), indium zinc oxide (ZIO), indium oxide (InO), titanium oxide (TiO), indium gallium zinc oxide (IGZO), indium zinc tin oxide (IZTO), indium zinc oxide (IZO), indium gallium tin oxide (IGTO), and indium gallium oxide (IGO), but is not limited thereto. The drain electrode 124 and the source electrode 125 can be a single layer or multiple layers made of a metal such as Au, W, Pt, Si, Ir, Ag, Cu, Ni, Cr, Mo, Ta, Cu, Ti, Al, etc. or their alloys or other conductive materials.

[0041] The thin film transistor is not limited to Figure 2 the structure shown, but various structures can be applied to the thin film transistor. For example, the thin film transistor can also have a bottom gate structure.

[0042] The thin film transistor can be referred to by any of the following terms in this article: driving part, driving driver, and driving chip.

[0043] In addition, the thin film transistor according to the present disclosure can drive a single micro light emitting diode (ED1), but is not limited thereto, and can drive a plurality of micro light emitting diodes (ED1).

[0044] The drain 124 and the source 125 can be connected to the semiconductor layer 121 through an interlayer insulating layer 127 (e.g., through holes therein) covering the gate electrode 123 and the semiconductor layer 121, respectively. The interlayer insulating layer 127 can be composed of a single layer or multiple layers made of an inorganic insulating material such as silicon oxide, silicon nitride, or silicon oxynitride.

[0045] The first planarization layer 129 can be disposed on the thin film transistor 120 and the interlayer insulating layer 127. The first planarization layer 129 can be made of an organic insulating material such as acrylic resin, epoxy resin, phenolic resin, polyamide resin, unsaturated polyester resin, polystyrene resin, polyphenylene sulfide resin, benzocyclobutene, polyacrylate, polyimide, etc., but the embodiments are not limited thereto.

[0046] The first electrode 131 can be disposed on the first planarization layer 129, and the first electrode 131 can be connected to the drain (or source) 124 of the thin film transistor 120 through the first planarization layer 129 (e.g., through holes therein) directly or through an interconnect structure such as a connection via connected to the first electrode 131. A second electrode 133 spaced apart from the first electrode 131 can be disposed on the first planarization layer 129. The second electrode 133 can be connected to a low potential line or a ground line (not specifically shown for simplicity).

[0047] The first electrode 131 and the second electrode 133 can be a single layer or multiple layers made of a metal or its alloy such as Au, W, Pt, Si, Ir, Ag, Cu, Ni, Cr, Mo, Ta, Cu, Ti, Al, etc.

[0048] An insulating layer 135 having an opening OP for exposing a part of the first electrode 131 and a part of the second electrode 133 can be disposed on the first planarization layer 129. The insulating layer 135 can be made of a photosensitive organic material such as photosensitive acrylic or an inorganic material such as silicon oxide, silicon nitride, silicon oxynitride, etc.

[0049] In the present disclosure, the insulating layer 135 can also be referred to as a bank layer.

[0050] Therefore, the insulating layer 135 can be a pixel defining layer or a sub - pixel defining layer that defines a plurality of pixels or sub - pixels.

[0051] In addition, the insulating layer 135 can be a black bank layer. This reduces unwanted light leakage and reflection.

[0052] The conductive adhesive layer 141 may be disposed on the first electrode 131 and the second electrode 133. The conductive adhesive layer 141 may be, for example, an anisotropic conductive film or solder.

[0053] The micro light-emitting diode ED1 may be disposed inside the opening OP of the insulating layer 135. The micro light-emitting diode ED1 may be disposed on the first electrode 131 and the second electrode 133. The micro light-emitting diode ED1 may be manufactured through a separate manufacturing process and then transferred onto the substrate 110.

[0054] The micro light-emitting diode ED1 may be mounted on the first electrode 131 and the second electrode 133 in a flip-chip arrangement through the conductive adhesive layer 141.

[0055] For example, the micro light-emitting diode ED1 may have a size of about 10 to 100 μm (e.g., 50 μm), but the embodiments are not limited thereto. The micro light-emitting diode ED1 may be formed using group III-V compound semiconductors such as GaP, GaAs, GaSb, InP, InAs, and / or InSb or group II-VI compound semiconductors such as CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, HgS, HgTe, and / or combinations thereof, but the embodiments are not limited thereto.

[0056] The micro light-emitting diode ED1 may include an n-type semiconductor layer 210; an active layer 220 having a single quantum well (SQW) structure or a multiple quantum well (MQW) structure; a p-type semiconductor layer 230 disposed on the active layer 220; a p-side electrode 250 disposed on the p-type semiconductor layer 230; and an n-side electrode 240 contacting the n-type semiconductor layer 210 in a partially removed region of the p-type semiconductor layer 230. Additionally, the micro light-emitting diode ED1 may include a passivation layer 260 covering the side surfaces and the lower / upper surfaces of the p-type semiconductor layer 230. Note that in this paragraph, when a feature is described as "on" a feature in ED1, as will be understood, due to the flip-chip arrangement, "on" means under rather than on top of.

[0057] The n-type semiconductor layer 210 may be a layer for supplying electrons to the active layer 220. For example, the n-type semiconductor layer 210 may be formed by doping an n-type impurity such as arsenic (As), phosphorus (P), antimony (Sb), germanium (Ge), tin (Sn), silicon (Si), etc. on GaN.

[0058] The active layer 220 may be a layer on which electrons and holes are coupled to generate light. For example, the active layer 220 may include at least one well layer made of indium gallium nitride and at least one barrier layer made of gallium nitride, but the embodiments are not limited thereto.

[0059] The p-type semiconductor layer 230 can be a layer for injecting holes into the active layer 220. For example, the p-type semiconductor 230 can be formed by doping p-type impurities such as indium (In), aluminum (Al), boron (B), gallium (Ga), Mg, Zn, and Be on GaN.

[0060] The p-side electrode 250 and the n-side electrode 240 can be composed of a single layer or multiple layers made of at least one metal or its alloy among W, Si, Ir, Ag, C, Ni, Au, Pt, Ti, Al, and Cr. An ohmic contact layer can be further provided between the p-side electrode 250 and the p-type semiconductor layer 230. The ohmic contact layer can be made of a transparent metal oxide such as ITO (indium tin oxide), IGZO (indium gallium zinc oxide), and IZO (indium zinc oxide).

[0061] The lens LS can be directly provided on the micro light-emitting diode ED1. The lens LS can have a larger area than the micro light-emitting diode ED1 to completely cover the micro light-emitting diode ED1. The upper surface of the lens LS can be a convex surface. The lens LS can be made of a transparent organic material. For example, the lens LS can be made of an acrylic-based resin or poly(3,4-ethylenedioxythiophene) PEDOT. The lens LS can be provided in one sub-pixel, and separate lens LSs can be provided for each micro light-emitting diode ED1.

[0062] In this embodiment, the lower surface of the lens LS can be directly attached to the micro light-emitting diode ED1 through its adhesive property. The micro light-emitting diode ED1 and the lens LS can be simultaneously mounted on the array panel DPS through a transfer process.

[0063] Therefore, different from the conventional manufacturing process of forming a lens by performing a photolithography process after a process of coating a material for forming the lens, in the present disclosure, the photolithography process can be eliminated, thereby simplifying the manufacturing method of the display device 100 and reducing the manufacturing cost.

[0064] The adhesive layer 143 may be disposed between the lens LS and the insulating layer 135. The adhesive layer 143 may also be disposed inside the opening OP of the insulating layer 135 to surround the side surface of the micro light-emitting diode ED1. In some implementations, the lens LS is larger in size on the x-axis and / or y-axis than the micro light-emitting diode EDI on the x-axis and / or y-axis, so as to form an undercut region UC. The undercut region UC enables the adhesive layer 143 to be directly disposed between the lens LS and the insulating layer 135, which further fixes the lens LS and the micro light-emitting diode ED1 to the DPS. In addition, the micro light-emitting diode EDI extends beyond the insulating layer 135 in the z-axis direction, such that there is a space 136 between the lens and the upper surface 138 of the insulating layer 135. The space 136 may be filled with the adhesive layer 143. Due to the adhesive layer 143, the lens LS and the micro light-emitting diode ED1 can be reliably and firmly mounted on the array panel DPS.

[0065] The adhesive layer 143 may also be referred to as a fixing member herein.

[0066] For example, the fixing member may include optical acrylic (PAC).

[0067] The adhesive layer 143 may further include light-diffusing particles capable of diffusing light.

[0068] For example, the light-diffusing particles may be, but are not limited to, inorganic light diffusing agents such as silica, alumina, glass, calcium carbonate (CaCO3), talc, mica, barium sulfate (BaSO4), zinc oxide (ZnO), cerium oxide (CeO2), and titanium dioxide (TiO2), or any mixture thereof.

[0069] The second planarization layer 151 may be disposed on the insulating layer 135 and the lens LS. The second planarization layer 151 may be made of a transparent organic material such as an acrylic-based resin or poly(3,4-ethylenedioxythiophene) PEDOT. The second planarization layer 151 may have a refractive index lower than that of the lens LS.

[0070] For example, the second planarization layer 151 may include an organic insulating material such as a polyacrylate resin, a polyimide resin, an epoxy resin, a phenolic resin, and a polyamide resin.

[0071] The second planarization layer 151 may also be referred to as an overcoat (OC) herein.

[0072] Since the lens LS having a curved upper surface is disposed on each micro light-emitting diode ED1, the light extraction efficiency of the micro light-emitting diode ED1 can be improved. Therefore, the display device 100 can operate with low power.

[0073] The protective film 155 may be disposed on the second planarization layer 151. The upper surface of the protective film 155 may be coated with at least one of an antireflection layer, an antiglare layer, and an anti-fingerprint layer.

[0074] Figure 3 is a plan view showing a display device according to an embodiment of the present disclosure. Figure 4 is along Figure 3 a cross-sectional view taken along the 4-4 cut of. Figure 3 and Figure 4 shows a region corresponding to one sub-pixel of the display device 100-1.

[0075] Referring to Figure 3 and Figure 4 the display device 100-1 may include a first connection electrode 137 connected to the first electrode 131 through an insulating layer 135 (e.g., through a hole therein); a second connection electrode 139 connected to the second electrode 133 through the insulating layer 135 (e.g., through another hole therein). A conductive adhesive layer 141 may be disposed on the first connection electrode 137 and the second connection electrode 139.

[0076] The micro light-emitting diode ED1' may be mounted in the opening OP of the insulating layer 135 in a horizontal chip arrangement, with the n-side electrode 240 and the p-side electrode 250 arranged upward. The micro light-emitting diode ED1' may be disposed on the reflective layer 140 inside the opening OP. The reflective layer 140 may include a metal having a high visible light reflectivity, such as aluminum (Al), silver (Ag), gold (Cu), molybdenum (Mo), or magnesium (Mg).

[0077] A lens LS having a first connection line W1 and a second connection line W2 may be directly disposed on the micro light-emitting diode ED1'. Three first connection lines W1 and three second connection lines W2 are shown, but this is only one example, and another number of first connection lines W1 and another number of second connection lines W2 may be provided. The first connection line W1 and the second connection line W2 may be made of a transparent conductive oxide such as indium tin oxide (ITO) or indium zinc oxide (IZO), a transparent conductive polymer such as poly(3-methylthiophene), poly(3,4-ethylenedioxythiophene) PEDOT, polypyrrole, and polyaniline, or a metal such as silver (Ag), copper (Cu), etc. The first connection line W1 and the second connection line W2 may be formed by using a conventional method well known in the art to which the present disclosure pertains.

[0078] In an embodiment, at least a part of the lower surface of the lens LS may be directly attached to the micro light-emitting diode ED1' due to the adhesion force of the lens LS, as will be understood. The micro light-emitting diode ED1' and the lens LS may be simultaneously mounted on the array panel DPS through one transfer process.

[0079] Therefore, different from the conventional manufacturing method of forming a lens by performing a photolithography process after a process of coating a material for forming the lens, this embodiment may not require a photolithography process for forming the lens, thereby simplifying the manufacturing method of the display device 100-1 and reducing the manufacturing cost.

[0080] The adhesive layer 143 may be disposed between the lens LS and the insulating layer 135. The adhesive layer 143 may surround the first connection electrode 137, the second connection electrode 139, and the conductive adhesive layer 141. In addition, the adhesive layer 143 may be disposed inside the opening OP of the insulating layer 135 and may surround the micro light-emitting diode ED1'. The micro light-emitting diode ED1' may be reliably and firmly mounted on the array panel DPS through the adhesive layer 143.

[0081] The first connection line W1 may be connected to the first connection electrode 137 through the conductive adhesive layer 141. The second connection line W2 may be connected to the second connection electrode 139 through the conductive adhesive layer 141.

[0082] The p-side electrode 250 of the micro light-emitting diode ED1' may be connected to the first electrode 131 via the first connection line W1, the conductive adhesive layer 141, and the first connection electrode 137. The first electrode 131 may be connected to the drain 124 of the thin-film transistor 120.

[0083] The n-side electrode 240 of the micro light-emitting diode ED1' may be connected to the second electrode 133 via the second connection line W2 and the second connection electrode 139. The second electrode 133 may be connected to a low-potential line or a ground line (not shown).

[0084] Since the lens LS having a curved top surface is disposed on each micro light-emitting diode ED1', the light extraction efficiency of the micro light-emitting diode ED1' can be improved. Therefore, the display device 100-1 can be operated with low power.

[0085] The second planarization layer 151 and the protective film 155 may be disposed on the lens LS.

[0086] In addition, the micro light-emitting diode ED1' may include a passivation layer covering the side surface of the n-type semiconductor layer 210.

[0087] Figure 5 is a plan view showing a display device according to an embodiment of the present disclosure. Figure 6 is along Figure 5 a cross-sectional view taken along cut 6-6 of Figure 5 and Figure 6 show a region corresponding to one sub-pixel of the display device 100-2.

[0088] Refer to Figure 5 andFigure 6 The display device 100-2 may include a first electrode 131 extending into an opening OP of the insulating layer 135 and a connection electrode 139 connected to a second electrode 133 through the insulating layer 135 (e.g., through a hole therein). The second electrode 133 may be at least partially covered by the insulating layer 135. A dummy connection electrode 139' may be provided opposite to and spaced apart from the connection electrode 139. In an embodiment, the dummy connection electrode 139' may be electrically connected to the connection electrode 139 through a connection line described later. Since the dummy connection electrode 139' is arranged opposite to the connection electrode 139, the lens LS and the micro light-emitting diode ED2 may be leveled. The micro light-emitting diode ED2 may include: a p-type semiconductor layer 230; an active layer 220 having a single quantum well SQW structure or a multiple quantum well MQW structure; an n-type semiconductor layer 210 provided on the active layer 220; a p-side electrode 250 provided on the first electrode 131; and an n-side electrode 240 provided on the n-type semiconductor layer 210. In addition, the micro light-emitting diode ED2 may include a passivation layer covering side surfaces of the n-type semiconductor layer 210 and the p-type semiconductor layer 230.

[0089] A conductive adhesive layer 141 may be provided on the second connection electrode 139 and the dummy connection electrode 139'. The conductive adhesive layer 141 may even be provided on the first electrode 131.

[0090] Although Figure 6 not shown in the figure, the micro light-emitting diode ED2 may be provided on a reflective layer within the opening OP. The reflective layer 140 may be provided above the first planarization layer 129, but is not limited thereto and may also be provided below the first planarization layer 129.

[0091] The micro light-emitting diode ED2 may be mounted in the opening OP of the insulating layer 135 in a vertical chip arrangement with the n-side electrode 240 facing upward and the p-side electrode 250 facing downward. The lens LS in which the connection line W is formed may be directly provided on the micro light-emitting diode ED2. Three connection lines W are shown provided, but this is an example, and another number of connection lines W may be provided. The connection line W may be made of a transparent conductive oxide, a transparent conductive polymer, a metal, etc. The connection line W may be manufactured by using a conventional method well-known in the art to which the present disclosure pertains.

[0092] In this embodiment, at least a part of the lower surface of the lens LS may be directly attached to the micro light-emitting diode ED2 due to the adhesion force of the lens LS, as will be understood. Both the lens LS on which the connection line W is formed and the micro light-emitting diode DE2 may be mounted on the array panel DPS through a single transfer process.

[0093] Therefore, different from the conventional manufacturing process of forming a lens by performing a photolithography process after coating a material for forming the lens, the embodiment may not require a photolithography process for forming the lens, thereby simplifying the manufacturing method of the display device 100-2 and reducing the manufacturing cost.

[0094] The adhesive layer 143 may be disposed between the lens LS and the insulating layer 135. The adhesive layer 143 may surround the connection electrode 139, the dummy connection electrode 139', and the conductive adhesive layer 141. It may even be disposed in the opening OP of the insulating layer 135 and surround the micro light-emitting diode ED2. Due to the adhesive layer 143, the lens LS and the micro light-emitting diode ED2 can be reliably mounted on the array panel DPS.

[0095] The adhesive layer 143 may be a transparent adhesive layer including a transparent material.

[0096] For example, the adhesive layer 143 may include, but is not limited to, an optically clear resin (OCR).

[0097] The connection line W may be connected to the connection electrode 139 and the dummy connection electrode 139' through the conductive adhesive layer 141.

[0098] The p-side electrode 250 of the micro light-emitting diode ED2 may be connected to the first electrode 131 through the conductive adhesive layer 141. The first electrode 131 may be connected to the drain 124 of the thin film transistor 120.

[0099] The n-side electrode 240 of the micro light-emitting diode ED2 may be connected to the second electrode 133 via the connection line W and the connection electrode 139. The second electrode 133 may be connected to a low potential line or a ground line (not shown).

[0100] Since the lens LS having a curved upper surface is disposed in each micro light-emitting diode ED1, the light extraction efficiency of the micro light-emitting diode ED2 can be improved. Therefore, the display device 100-2 can be operated with low power.

[0101] The second planarization layer 151 and the protective film 155 may be disposed on the lens LS.

[0102] Figures 7a to 7f is a view for describing a manufacturing method of a display device according to an embodiment of the present disclosure.

[0103] Referring to Figure 7a , a mold MD including convex portions CP each having a raised curved surface can be manufactured. The convex portions CP may have a shape corresponding to the shape of the lens LS desired to be formed in a subsequent process. The mold MD can be manufactured by using a conventional method well known in the art to which the present disclosure pertains.

[0104] The impression ST is coated on the mold MD. For example, the impression ST can be made of a silicone rubber such as polydimethylsiloxane (PDMS) or an elastomer such as polyurethane (PU) and polytetrafluoroethylene (PTFE).

[0105] Reference Figure 7b , the substrate SS can be attached to the impression ST. An adhesive layer can be further provided between the substrate SS and the impression ST. The adhesive layer can be made of materials well known in the art, especially a pressure-sensitive adhesive PSA, but the embodiments are not limited thereto, and it can also be made of an optically transparent adhesive (OCA), an optically transparent resin (OCR), etc.

[0106] Refer to Figure 7c , the mold MD is removed from the impression ST. As a result, a concave portion CR corresponding to the lens LS in shape can be formed in the impression ST.

[0107] Refer to Figure 7d , the lens LS can be formed in the concave portion CR of the impression ST. The lens LS can be formed by coating an acrylic-based resin or poly(3,4-ethylenedioxythiophene) PEDOT, etc. on the concave portion CR.

[0108] Reference Figure 7e , the micro light-emitting diode ED1 can be preliminarily transferred to the lens LS of the impression ST.

[0109] The micro light-emitting diode ED1 can be peeled off from the wafer on which the micro light-emitting diode ED1 is formed and disposed on a carrier substrate (or donor substrate) by a laser lift-off process or a chemical lift-off process. The micro light-emitting diode ED1 can be preliminarily transferred from the carrier (or donor substrate) on which the micro light-emitting diode ED1 is disposed to the lens LS.

[0110] Reference Figure 7f , the micro light-emitting diode ED1 and the lens LS can be secondarily transferred from the impression ST to the array panel DPS.

[0111] After the adhesive layer 143 and the conductive adhesive layer 141 are coated on the array panel DPS, the impression ST can be aligned and an appropriate transfer pressure can be applied. Then, the lens LS and the micro light-emitting diode ED1 can be simultaneously transferred to the array panel DPS.

[0112] For this purpose, the adhesion force between the adhesive layer 143 and the lens LS can be designed to be greater than the adhesion force between the lens LS and the impression ST. The adhesion force between the micro light-emitting diode ED1 and the lens LS can be designed to be greater than the adhesion force between the lens LS and the impression ST.

[0113] Figures 8a to 8c is a view illustrating a method of manufacturing the display device 100-1 according to an embodiment of the present disclosure.

[0114] Referring to Figure 8a , the lens LS may be formed in the concave portion CR of the mold ST, as described above with reference to Figures 7a to 7d . Thereafter, connection lines W1 and W2 may be formed on the lens LS. The connection lines W1 and W2 may be made of a transparent conductive oxide, a transparent polymer, a metal, etc. The connection lines W1 and W2 may be formed by using a method well-known in the art to which the present disclosure pertains.

[0115] Referring to Figure 8b , the micro light-emitting diode ED1' may be initially transferred to the lens LS of the mold ST. The micro light-emitting diode ED1' may be initially transferred from the wafer on which the micro light-emitting diode ED1' is formed to the lens LS by a laser lift-off process or a chemical lift-off process.

[0116] Referring to Figure 8c , the micro light-emitting diode ED1', the connection lines W, and the lens LS may be secondarily transferred from the mold ST to the array panel DPS.

[0117] After the adhesive layer 143 and the conductive adhesive layer 141 are coated on the array panel DPS, the mold ST may be aligned and an appropriate transfer pressure may be applied. Accordingly, the lens LS, the micro light-emitting diode ED1', and the connection lines W1 and W2 may be simultaneously transferred to the array panel DPS.

[0118] To this end, the adhesion force between the lens LS and the mold ST may be designed to be less than the adhesion force between the adhesive layer 143 and the lens LS. In addition, the adhesion force between the micro light-emitting diode ED1' and the lens LS may be designed to be greater than the adhesion force between the lens LS and the mold ST.

[0119] A display device and a method of manufacturing the same according to an embodiment of the present disclosure will be described below.

[0120] A display device according to an embodiment of the present disclosure may include: a substrate; a planarization layer disposed on the substrate; a first electrode and a second electrode disposed on the planarization layer; an insulating layer disposed on the first electrode and the second electrode, the insulating layer including an opening; a micro light-emitting diode disposed in the opening of the insulating layer; a lens disposed on the micro light-emitting diode; and an adhesive layer disposed between the lens and the insulating layer.

[0121] According to some embodiments of the present disclosure, the adhesive layer surrounds a side surface of the micro light-emitting diode within the opening.

[0122] According to some embodiments of the present disclosure, the first electrode and the second electrode may be exposed through the opening, and the micro light-emitting diode may be mounted in a flip-chip type with the n-side electrode and the p-side electrode facing downward in the first electrode and the second electrode.

[0123] According to some embodiments of the present disclosure, the display device may further include a first connection electrode connected to the first electrode through an insulating layer; a second connection electrode connected to the second electrode through the insulating layer; and a first connection line and a second connection line disposed on a lower surface of the lens.

[0124] According to some embodiments of the present disclosure, the micro light-emitting diodes may be disposed inside the opening in a horizontal chip type with the n-side electrode and the p-side electrode facing upward. The p-side electrode of the micro light-emitting diode may be connected to the first electrode via the first connection line and the first connection electrode, and the n-side electrode of the micro light-emitting diode may be connected to the second electrode via the second connection line and the second connection electrode.

[0125] According to some embodiments of the present disclosure, the display device may further include: a connection electrode connected to the second electrode through an insulating layer; a dummy connection electrode disposed on the insulating layer; and a connection line disposed on a lower surface of the lens.

[0126] According to some embodiments of the present disclosure, the first electrode may be exposed through the opening. The micro light-emitting diodes may be disposed in the opening in a vertical chip arrangement with the n-side electrode facing upward and the p-side electrode facing downward. The p-side electrode of the micro light-emitting diode may be connected to the first electrode, and the n-side electrode of the micro light-emitting diode may be connected to the second electrode via the connection line and the connection electrode.

[0127] A method of manufacturing a display device according to an embodiment of the present disclosure may include: forming a stamper having a recess; forming a lens in the recess; preliminarily transferring a micro light-emitting diode to the lens; preparing an array substrate on which an adhesive layer is coated on each sub-pixel; and secondarily transferring the lens and the micro light-emitting diode together to the array substrate.

[0128] According to some embodiments of the present disclosure, the method of manufacturing the display device may further include forming a connection line on the lens after forming the lens in the recess.

[0129] According to some embodiments of the present disclosure, the connection line may include at least one first connection line and at least one second connection line spaced apart from each other.

[0130] According to some embodiments of the present disclosure, the stamper may be made of polydimethylsiloxane, and the lens may be made of an acrylic-based resin.

[0131] According to some embodiments of the present invention, the adhesion between the adhesive layer and the lens may be greater than the adhesion between the lens and the stamper.

[0132] A display device according to an embodiment of the present disclosure may include: a substrate; a first electrode and a second electrode disposed on the substrate; a bank layer disposed on the first electrode and the second electrode, the bank layer including an opening; a micro light-emitting diode disposed in the opening of the bank layer; a high refractive index layer disposed on the micro light-emitting diode; an outer coating disposed on the high refractive index layer and having a refractive index lower than that of the high refractive index layer; and an adhesive layer disposed between the lens and the insulating layer.

[0133] According to some embodiments of the present disclosure, a fixing member surrounds a side surface of the micro light-emitting diode within the opening.

[0134] According to some embodiments of the present disclosure, the first electrode and the second electrode may be exposed through the opening, and the micro light-emitting diode may be mounted in the first electrode and the second electrode in a flip-chip arrangement with the n-side electrode and the p-side electrode disposed downward.

[0135] According to some embodiments of the present disclosure, the display device may further include a first connection electrode connected to the first electrode through the bank layer; a second connection electrode connected to the second electrode through the bank layer; and a first connection line and a second connection line disposed on a lower surface of the high refractive index layer.

[0136] According to some embodiments of the present disclosure, in a horizontal chip arrangement in which the n-side electrode and the p-side electrode are disposed upward, the micro light-emitting diode may be disposed in the opening, the p-side electrode of the micro light-emitting diode may be connected to the first electrode via the first connection line and the first connection electrode, and the n-side electrode of the micro light-emitting diode may be connected to the second electrode via the second connection line and the second connection electrode.

[0137] A display device according to an embodiment of the present disclosure may include: a substrate; a first electrode and a second electrode disposed on the substrate; a bank layer disposed on the first electrode and the second electrode to define a pixel; a micro light-emitting diode disposed in each pixel; and a connection electrode penetrating the bank layer and connected to the second electrode, wherein the micro light-emitting diode includes a lower portion electrically connected to the first electrode via the connection electrode and an upper portion electrically connected to the second electrode.

[0138] According to some embodiments of the present disclosure, the micro light-emitting diode may be in the form of a vertical chip.

[0139] According to some embodiments of the present disclosure, the upper portion may be electrically connected to the connection electrode via a connection line.

[0140] According to some embodiments of the present disclosure, the micro light-emitting diode may be disposed on a reflective layer in the opening of the bank layer.

[0141] According to some embodiments of the present disclosure, the micro light-emitting diode may include an n-side electrode disposed upward and a p-side electrode disposed downward.

[0142] According to some embodiments of the present disclosure, the micro light-emitting diode may further include an n-type semiconductor layer and a p-type semiconductor layer.

[0143] According to some embodiments of the present disclosure, the micro light-emitting diode may include a passivation layer covering side surfaces of the n-type semiconductor layer and the p-type semiconductor layer.

[0144] According to some embodiments of the present disclosure, the micro light-emitting diode may further include an active layer having a single quantum well (SQW) structure or a multi quantum well (MQW) structure; an n-type semiconductor layer disposed on the active layer; a p-side electrode disposed on the first electrode; and an n-side electrode disposed on the n-type semiconductor layer.

[0145] According to some embodiments of the present disclosure, the display device may further include a high refractive index layer disposed on the micro light-emitting diode.

[0146] According to some embodiments of the present disclosure, the display device may further include an outer coating disposed on the high refractive index layer, the outer coating having a refractive index lower than that of the high refractive index layer.

[0147] According to some embodiments of the present disclosure, the display device may further include a fixing member disposed between the high refractive index layer and the bank layer.

[0148] According to some embodiments of the present disclosure, the high refractive index layer may include a lens.

[0149] A display device according to an embodiment of the present disclosure may include: a substrate; a first electrode and a second electrode disposed on the substrate; a bank layer disposed on the first electrode and the second electrode, the bank layer including an opening; a micro light-emitting diode disposed in the opening of the bank layer; a high refractive index layer disposed on the micro light-emitting diode; an outer coating disposed on the high refractive index layer and having a refractive index lower than that of the high refractive index layer; and a fixing member disposed between the high refractive index layer and the bank layer.

[0150] Although the present disclosure has been described with reference to the exemplary drawings, it should be understood that the present disclosure is not limited to the embodiments and drawings disclosed in this specification, and those skilled in the art will understand that various modifications are possible without departing from the scope of the present disclosure. In addition, although the operating effects of the configuration according to the present disclosure are not explicitly described while describing the embodiments of the present disclosure, it should be understood that predictable effects can also be recognized through this configuration.

Claims

1. A display device, the display device comprising: A substrate (110): A first electrode (131) and a second electrode (133) disposed on the substrate; A bank layer (135) disposed on the first electrode and the second electrode, the bank layer including an opening (OP); A micro light-emitting diode (ED2) disposed in the opening of the bank layer; A high refractive index layer (LS) disposed on the micro light-emitting diode; An outer coating (151) disposed on the high refractive index layer and having a refractive index lower than that of the high refractive index layer; and A fixing member (143) disposed between the high refractive index layer and the bank layer.

2. The display device according to claim 1, the display device further comprising: A connection electrode (139) connected to the second electrode (133) through the bank layer (135).

3. The display device according to claim 2, the display device further comprising a dummy connection electrode (139') disposed on the bank layer (135).

4. The display device according to claim 3, the display device further comprising: A connection line (W) disposed on the lower surface of the high refractive index layer (LS).

5. The display device according to any one of the preceding claims, wherein, The first electrode (131) is exposed through a bank opening (OC).

6. The display device according to any one of the preceding claims, wherein, The micro light-emitting diode (ED2) is disposed in the bank opening (OC) in a vertical chip arrangement with the n-side electrode (240) facing upward and the p-side electrode (250) facing downward.

7. The display device according to claim 6, wherein, The p-side electrode (250) of the micro light-emitting diode (ED2) is connected to the first electrode (131).

8. The display device according to claim 7, wherein, The n-side electrode (240) of the micro light-emitting diode (ED2) is connected to the second electrode (133) via the connection line (W) and the connection electrode (39').

9. The display device according to any one of the preceding claims, wherein, A protective film (155) is disposed on the outer coating (151).

10. The display device according to any one of the preceding claims, wherein, The fixing member (143) surrounds the connection line (W).

11. The display device according to any one of the preceding claims, wherein, The first electrode (131) is connected to a driving chip.

12. The display device according to any one of the preceding claims, wherein, The bank layer (135) includes a black pigment.

13. The display device according to any one of claims 9 to 12, wherein, The upper surface of the protective film (155) is coated with at least one of an anti-reflection layer, an anti-glare layer, or an anti-fingerprint layer.

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