TWI872890B - Display apparatus - Google Patents

Abstract

There is disclosed a display apparatus including a substrate, a first electrode and a second electrode that are disposed on the substrate, a bank layer disposed on the first electrode and the second electrode, the bank layer comprising an opening, a micro light emitting diode disposed inside the opening of the bank layer, a high refractive index layer disposed on the micro light emitting diode, an overcoat layer disposed on the high refractive index layer and having a lower refractive index than the high refractive index layer, and a fixation member disposed between the high refractive index layer and the bank layer.

Description

Display device

The present invention relates to a display device, in particular to a display device that can simplify the manufacturing process and a manufacturing method thereof.

In flat panel displays, liquid crystal display devices (LCD) or organic light emitting display devices (OLED) are often used.

Compared with liquid crystal display devices, organic light-emitting display devices have advantages such as improved light-emitting efficiency, fast response speed, wide viewing angle, etc. However, organic light-emitting display devices still have low light-emitting efficiency and are easily affected by external substances such as moisture because they contain organic materials. Therefore, the reliability and life of organic light-emitting display devices may be deteriorated.

Recently, micro-LED display devices have been proposed as inorganic light-emitting display devices.

A micro-LED display device can realize an image by using an inorganic LED having a size of approximately 100 micrometers (μm) or less arranged in each pixel. In the micro-LED, a process of transferring the micro-LED arranged on a single crystal substrate to an array substrate of a display device using a die press or the like has been performed.

Descriptions provided in the prior art section should not be assumed to be prior art simply because they are mentioned in or related to the prior art section. The prior art section may contain information describing one or more aspects of the subject technology.

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

In some solutions, after the process of transferring the micro-LED and the process of connecting the electrodes are performed, the lens is formed by using the material for forming the lens and performing an exposure process. The inventors recognize that the performance of the exposure process for forming the lens has the disadvantages of a complicated manufacturing process of the display device and an increase in manufacturing cost.

The inventor of the present invention has invented a method for manufacturing a display device that can simultaneously transfer micro-light-emitting diodes and lenses.

The present invention according to the embodiment provides a display device and a manufacturing method thereof that can simplify its manufacturing process.

The aspects and technical features of the present invention are not limited to the above. Those with ordinary knowledge in the relevant technical field can clearly understand from the following description, and can more clearly understand other aspects and features not mentioned above from the embodiments described in this article.

The display device according to the embodiment of the present invention 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 and including an opening, a micro-light-emitting diode disposed inside 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.

The manufacturing method of the display device according to the embodiment of the present invention may include: forming a die with a concave portion; forming a lens in the concave portion; initially transferring the micro-LED to the lens; preparing an array substrate on which an adhesive layer is coated on each sub-pixel; and then transferring the lens together with the micro-LED to the array substrate.

Detailed descriptions of other embodiments are included in the following description and accompanying drawings.

Additional features and aspects will be partially described in the subsequent description, and some will be obvious to those having ordinary knowledge in the art, or can be learned by practicing the concepts of the present invention provided herein. Other features and aspects of the concepts of the present invention can be realized or obtained by the structures specifically pointed out in the description or their derivative structures, its claims and the attached drawings.

According to an embodiment of the present invention, the lens and the micro-LED can be simultaneously disposed on the array panel by a transfer process. Therefore, unlike the existing manufacturing process in which the lens is formed by performing a lithography process after a process of applying a material for forming the lens, the lithography process can be removed in the present invention, thereby simplifying the manufacturing method of the display device and reducing the manufacturing cost.

Since a lens having a curved upper surface is provided in each micro-LED, light extraction efficiency of the micro-LED can be improved. Therefore, the display device can be operated at low power.

In order to implement the present invention, in addition to the above-mentioned effects, the special effects of the present invention will be described together with the following detailed description.

100: Display device

100-1: Display device

100-2: Display device

110: Substrate

120: Thin Film Transistor

121: Semiconductor layer

122: Gate insulation layer

123: Gate electrode

124: Drain electrode

125: Source electrode

127: Middle layer insulation layer

129: First planarization layer

131: First electrode

133: Second electrode

135: Insulation layer

136: Space

137: Connecting electrodes

138: Upper surface

139: Connecting electrodes

139 ' : Virtual connection electrode

140:Reflective layer

141: Conductive adhesive layer

143: Adhesive layer

151: Second planarization layer

155: Protective film

2-2: Line

210: n-type semiconductor layer

220: Active layer

230: p-type semiconductor layer

240:n-side electrode

250: p-side electrode

260: Passivation layer

4-4: Line

6-6: Line

CP: convex part

CR: Concave

DPS: Array Panel

ED1: Micro LED

ED1 ' : Micro LED

ED2: Micro LED

LS: Lens

MD: Mold

OP: Open mouth

SS: Base substrate

ST: Die pressing

UC: Undercut area

W:Connection line

W1: First connection line

W2: Second connection line

FIG. 1 is a plan view of a display device according to an exemplary embodiment of the present invention; FIG. 2 is a cross-sectional schematic diagram along the 2-2 section of FIG. 1; FIG. 3 is a plan view of a display device according to another exemplary embodiment of the present invention; FIG. 4 is a cross-sectional schematic diagram along the 4-4 section of FIG. 3; FIG. 5 is a plan view of a display device according to a further exemplary embodiment of the present invention; FIG. 6 is a cross-sectional schematic diagram along the 6-6 section of FIG. 5; FIG. 7a to FIG. 7f are diagrams describing a method for manufacturing a display device according to an exemplary embodiment of the present invention; and FIG. 8a to FIG. 8c are diagrams describing a method for manufacturing a display device according to an exemplary embodiment of the present invention.

The technical benefits, features, advantages and methods of achieving the same will be described in detail with reference to the attached drawings, and therefore, a person with ordinary knowledge in the technical field to which the present invention belongs will be able to easily implement the technical ideas of the present invention. When describing the present invention, if the detailed description of the known technology related to the present invention may unnecessarily obscure the subject name of the present invention, the detailed description will be omitted.

Hereinafter, the exemplary embodiments of the present invention will be described in detail with reference to the attached drawings. In the drawings, the same reference numerals indicate the same or similar elements. When explaining the present invention, except for the special description in the attached drawings, it should be extended to any modifications, equivalents and substitutes. The terms used for the respective elements described below are defined terms that take into account the functions obtained in the present invention. Therefore, these terms do not limit the technical elements in the present invention. Furthermore, the defined terms of the respective elements may be referred to as other terms in the relevant technical field. Unless otherwise expressly stated, the description in the singular form may include the description in the plural form. The terms such as "comprising", "including", "containing", "consisting of" or "having" used herein should be understood to be intended to indicate the presence of several elements, functions or steps disclosed herein, and it is also understood that more or fewer elements, functions or steps can be used in the same manner.

Even if not explicitly stated, components are interpreted as including a tolerance range.

When an element is considered to be "connected to" or "attached to" another element, it should be understood that the element is directly connected to or attached to the other element, or there may be intervening elements. Conversely, when an element is considered to be "directly connected to" another element, there are no intervening elements.

When describing a temporal relationship, for example, the temporal sequence between two events, such as "after", "afterwards", "next", "before", etc., another event can occur in between, unless a more restrictive term such as "directly", "immediately" or "immediately" is used.

It should be understood that although the terms "first", "second", etc. may be used herein to describe various different components, these components should not be limited by these terms. These terms are generally used only to distinguish one component from another component.

The features of the various embodiments may be coupled or combined with each other in part or in whole, and various connections and drives are possible. Furthermore, these embodiments may be implemented independently or in association with each other.

In this article, the display device according to the embodiment of the present invention will be described with reference to the attached drawings.

FIG. 1 is a plan view of a display device according to an embodiment of the present invention. FIG. 2 is a cross-sectional schematic diagram along the 2-2 section of FIG. 1 . FIG. 1 and FIG. 2 illustrate an area corresponding to a sub-pixel of the display device 100.

Referring to FIG. 1 and FIG. 2 , a display device 100 according to an embodiment may include an array panel DPS, a micro light emitting diode ED1 disposed on the array panel DPS, and a lens LS disposed on the micro light emitting diode ED1.

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.

The substrate 110 may be made of glass or plastic. For example, polyimide (PI), polyethylene terephthalate (PET), acrylonitrile-butadiene-styrene copolymer (ABS), polymethyl methacrylate (PMMA), polyethylene naphthalate (PEN), polycarbonate (PC), polyether sulfone (PES), polyarylate (PAR), polysulfone (PSF), or cycloolefin copolymer (COC), cellulose triacetate (TAC) film, polyvinyl alcohol (PVA) film, and polystyrene (PS) may be used as the plastic substrate, but the present invention is not limited thereto.

The thin film transistor 120 may include a semiconductor layer 121 formed on the substrate 110, a gate insulating layer 122 and a gate electrode 123 disposed on the semiconductor layer 121, and a drain (or source) electrode 124 and a source (or drain) electrode 125.

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

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

In this article, thin film transistors may be referred to as any of the following terms: driver part, driver driver, and driver chip.

Furthermore, the thin film transistor according to the present invention can drive one micro light emitting diode (ED1), but is not limited thereto, and can drive multiple micro light emitting diodes (ED1).

The drain electrode 124 and the source electrode 125 can be connected to the semiconductor layer 121 through the intermediate insulating layer 127 (e.g., a hole in the intermediate insulating layer 127) covering the gate electrode 123 and the semiconductor layer 121, respectively. The intermediate 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.

The first planarization layer 129 can be disposed on the thin film transistor 120 and the intermediate insulating layer 127. The first planarization layer 129 can be made of organic insulating materials such as acrylic resin, epoxy resin, phenolic resin, polyamide resin, unsaturated polyester resin, polyphenylene resin, polyphenylene sulfide resin, benzocyclobutene, polyacrylate, polyimide, etc., but the embodiment is not limited thereto.

The first electrode 131 may be disposed on the first planarization layer 129, and the first electrode 131 may be directly connected to the drain (or source) electrode 124 of the thin film transistor 120 through the first planarization layer 129 (e.g., a hole in the first planarization layer 129), or connected to the drain (or source) electrode 124 of the thin film transistor 120 through, for example, an interconnect structure coupled to the first electrode 131. The second electrode 133 separated from the first electrode 131 may be disposed on the first planarization layer 129. The second electrode 133 may be connected to a low potential line or a ground line (not specifically shown for simplicity).

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

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

In the present invention, the insulating layer 135 may also be referred to as a bank layer.

Therefore, the insulating layer 135 may be a pixel defining layer or a sub-pixel defining layer that defines a plurality of pixels or sub-pixels.

Furthermore, the bank layer can be a black bank layer. This reduces unnecessary light leakage and reflection.

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

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 by a separate manufacturing process and then transferred to the substrate 110.

The micro light-emitting diode ED1 can be disposed on the first electrode 131 and the second electrode 133 in a flip-chip arrangement through a conductive adhesive layer 141.

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

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. In addition, the micro light emitting diode ED1 may include a passivation layer 260 covering the side surface and the lower/upper surface of the p-type semiconductor layer 230. As will be understood, it is noted that in this paragraph, when a feature is described as being located "above" a feature in micro-LED ED1, due to the flip chip arrangement, "above" means below and not above.

The n-type semiconductor layer 210 may be a layer for providing electrons to the active layer 220. For example, the n-type semiconductor layer 210 may be formed by doping n-type impurities, such as arsenic (As), phosphorus (P), antimony (Sb), germanium (Ge), tin (Sn), and silicon (Si) into GaN.

The active layer 220 may be a layer that couples electrons and holes to generate light. For example, the active layer 220 may include at least one well layer made of InGaN and at least one barrier layer made of GaN, but the embodiment is not limited thereto.

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

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

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

In this embodiment, the lower surface of the lens LS can be directly attached to the micro-LED ED1 by its adhesive properties. The micro-LED ED1 and the lens LS can be simultaneously disposed on the array panel DPS by a transfer process.

Therefore, unlike the existing manufacturing process of forming a lens by performing a lithography process after a process of applying a material for forming the lens, the lithography process can be removed in the present invention, thereby simplifying the manufacturing method of the display device 100 and reducing the manufacturing cost.

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 embodiments, the size of the lens LS on the x-axis and/or the y-axis is larger than the size of the micro light emitting diode EDI on the x-axis and/or the y-axis, thereby forming 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. Furthermore, the micro-light emitting diode ED1 extends beyond the insulating layer 135 along the z-axis, so that there is a space 136 between the upper surface 138 of the insulating layer 135 and the lens. The space 136 may be filled with an adhesive layer 143. Based on the adhesive layer 143, the lens LS and the micro-light emitting diode ED1 may be securely disposed on the array panel DPS with reliability.

In this article, the adhesive layer 143 may also be referred to as a fixing member.

For example, the fixing may comprise photo acrylic (PAC).

The adhesive layer 143 may further include light diffuser particles capable of diffusing light.

For example, the light diffuser particles may be, but are not limited to, inorganic light diffusers such as silica, alumina, glass, calcium carbonate (CaCO ₃ ), talc, mica, barium sulfate (BaSO ₄ ), zinc oxide (ZnO), caesium oxide (CeO ₂ ), and titanium dioxide (TiO ₂ ), or any mixture thereof.

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 resin or poly(3,4-ethylenedioxythiophene) (PEDOT). The second planarization layer 151 may have a lower refractive index than the lens LS.

For example, the second planarization layer 151 may include an organic insulating material such as polyacrylate resin, polyimide resin, epoxy resin, phenol resin, and polyamide resin.

In this article, the second planarization layer 151 may also be referred to as an outer coating layer (OC).

Since the lens LS having a curved upper surface is provided 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 be operated at low power.

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 anti-reflection layer, an anti-glare layer, and an anti-fingerprint layer.

FIG. 3 is a plan view of a display device according to an embodiment of the present invention. FIG. 4 is a cross-sectional schematic diagram taken along line 4-4 of FIG. 3 . FIG. 3 and FIG. 4 illustrate an area corresponding to a sub-pixel of the display device 100-1.

3 and 4, the display device 100-1 may include a first connection electrode 137 connected to the first electrode 131 through the insulating layer 135 (e.g., a hole in the insulating layer 135), and a second connection electrode 139 connected to the second electrode 133 through the insulating layer 135 (e.g., another hole in the insulating layer 135). The conductive adhesive layer 141 may be disposed on the first connection electrode 137 and the second connection electrode 139.

The micro light emitting diode ED1 ' may be arranged in a horizontal wafer arrangement inside the opening OP of the insulating layer 135, wherein the n-side electrode 240 and the p-side electrode 250 are arranged upward. The micro light emitting diode ED1 ' may be arranged 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 (Au), molybdenum (Mo), or magnesium (Mg).

The lens LS having the first connection line W1 and the second connection line W2 can be directly arranged on the micro light-emitting diode ED1 ' . It can be seen that three first connection lines W1 and three second connection lines W2 are arranged, but this is one example, and other numbers of first connection lines W1 and other numbers of second connection lines W2 can be arranged. The first connection line W1 and the second connection line W2 can be made of transparent conductive oxides such as indium tin oxide (ITO) or indium zinc oxide (IZO), transparent conductive polymers such as poly (3-methylthiophene), poly (3,4-ethylenedioxythiophene) (PEDOT), polypyrrole and polyaniline, or metals such as silver (Ag), copper (Cu), etc. The first connection line W1 and the second connection line W2 may be formed by using existing methods known in the art related to the present invention.

In this embodiment, as will be understood, based on the adhesive force of the lens LS, at least a portion of the lower surface of the lens LS can be directly attached to the micro light emitting diode ED1 ' . The micro light emitting diode ED1 ' and the lens LS can be simultaneously disposed on the array panel DPS by a transfer process.

Therefore, unlike the existing manufacturing method of forming a lens by performing a lithography process after applying a process of a material for forming a lens, this embodiment does not require a lithography process for forming a lens, thereby simplifying the manufacturing method of the display device 100-1 and reducing the manufacturing cost.

The adhesive layer 143 may be disposed between the lens LS and the insulating layer 135. The adhesive layer 143 may surround the first connecting electrode 137, the second connecting electrode 139, and the conductive adhesive layer 141. Furthermore, 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 securely and reliably disposed on the array panel DPS by the adhesive layer 143.

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

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 electrode 124 of the thin film transistor 120.

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

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

The second planarization layer 151 and the protective film 155 can be disposed on the lens LS.

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

FIG. 5 is a plan view of a display device according to an embodiment of the present invention. FIG. 6 is a cross-sectional schematic diagram taken along line 6-6 of FIG. 5 . FIG. 5 and FIG. 6 illustrate an area corresponding to a sub-pixel of the display device 100-2.

5 and 6 , the display device 100-2 may include a first electrode 131 extending into an opening OP of an insulating layer 135 and a connecting electrode 139 connected to a second electrode 133 through the insulating layer 135 (e.g., a hole in the insulating layer 135). The second electrode 133 may be at least partially covered by the insulating layer 135. A dummy connecting electrode 139 ' may be disposed separately from the connecting electrode 139. In this embodiment, the dummy connecting electrode 139 ' may be electrically connected to the connecting electrode 139 through a connecting line described later. Since the virtual connection electrode 139 ' is arranged relative to the connection electrode 139, the lens LS and the micro light-emitting diode ED2 can ensure horizontality. The micro light-emitting diode ED2 can 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, which is arranged on the active layer 220; a p-side electrode 250, which is arranged on the first electrode 131; and an n-side electrode 240, which is arranged on the n-type semiconductor layer 210. In addition, the micro light emitting diode ED2 may include a passivation layer covering the side surfaces of the n-type semiconductor layer 210 and the p-type semiconductor layer 230 .

The conductive adhesive layer 141 may be disposed on the second connecting electrode 139 and the dummy connecting electrode 139 ′ . The conductive adhesive layer 141 may even be disposed on the first electrode 131.

Although not shown in FIG. 6 , the micro light-emitting diode ED2 can be disposed on the reflective layer in the opening OP. The reflective layer 140 can be disposed on the top of the first planarization layer 129 , but is not limited thereto, and can also be disposed below the first planarization layer 129 .

The micro-light-emitting diode ED2 can be arranged in a vertical chip arrangement at the opening OP of the insulating layer 135, wherein the n-side electrode 240 is arranged upward and the p-side electrode 250 is arranged downward. The lens LS formed with the connection line W can be directly arranged on the micro-light-emitting diode ED2. It can be seen that there are three connection lines W, but this is one example, and other numbers of connection lines W can be arranged. The connection line W can be made of transparent conductive oxide, transparent conductive polymer, metal, etc. The connection line W can be manufactured by using existing methods known in the art related to the present invention.

In this embodiment, as will be understood, at least a portion of the lower surface of the lens LS can be directly attached to the micro-LED ED2 due to the adhesive force of the lens LS. The lens LS formed with the connection line W and the micro-LED ED2 can be set on the array panel DPS by a transfer process.

Therefore, unlike the existing manufacturing process in which a lens is formed by performing a lithography process after the material for forming the lens is applied, this embodiment does not require a lithography process for forming the lens, thereby simplifying the manufacturing method of the display device 100-2 and reducing the manufacturing cost.

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 at the opening OP of the insulating layer 135 and surround the micro light emitting diode ED2. Based on the adhesive layer 143, the lens LS and the micro light emitting diode ED2 may be disposed on the array panel DPS with reliability.

The adhesive layer 143 may be a transparent adhesive layer comprising a transparent material.

For example, the adhesive layer 143 may include, but is not limited to, optical clear resin (OCR).

The connection line W can be connected to the connection electrode 139 and the dummy connection electrode 139 ' through the conductive adhesive layer 141.

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

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

Since the lens LS having a curved upper surface is provided 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 at low power.

The second planarization layer 151 and the protective film 155 can be disposed on the lens LS.

Figures 7a to 7f are diagrams describing a method for manufacturing a display device according to an embodiment of the present invention.

Referring to FIG. 7a, a mold MD including convex portions CP each having a convexly curved surface may be manufactured. The convex portion CP may have a shape corresponding to the shape of a lens LS to be formed in a subsequent process. The mold MD may be manufactured by using an existing method known in the art related to the present invention. A die ST is applied to the mold MD. For example, the die ST may be made of silicone rubber such as polydimethylsiloxane (PDMS) or an elastomer such as polyurethane (PU) and polytetrafluoroethylene (PTFE).

Referring to FIG. 7b , the base substrate SS may be attached to the die ST. An adhesive layer may be further disposed between the base substrate SS and the die ST. The adhesive layer may be made of a material known in the art, specifically, a pressure sensitive adhesive (PSA), but the embodiment is not limited thereto, and may also be made of an optical clear adhesive (OCA), an optical clear resin (OCR), etc.

Referring to FIG. 7c , the mold MD is removed from the die ST. Therefore, a recess CR having a shape corresponding to the lens LS can be formed in the die ST.

Referring to FIG. 7d , the lens LS may be formed in the concave portion CR of the die ST. The lens LS may be formed by applying an acrylic resin or poly(3,4-ethylenedioxythiophene) (PEDOT) or the like to the concave portion CR.

Referring to FIG. 7e, the micro light-emitting diode ED1 can first be transferred to the lens LS of the die ST.

The micro-LED ED1 can be stripped from a wafer forming the micro-LED ED1 by a laser stripping process or a chemical stripping process and disposed on a carrier substrate (or a donor substrate). The micro-LED ED1 can be initially transferred from the carrier (or donor substrate) on which the micro-LED ED1 is disposed to the lens LS.

Please refer to Figure 7f, the micro-LED ED1 and the lens LS can then be transferred from the die ST to the array panel DPS.

After the adhesive layer 143 and the conductive adhesive layer 141 are coated on the array panel DPS, the stamp ST can be aligned and appropriate transfer pressure can be applied. Then, the lens LS and the micro light-emitting diode ED1 can be transferred to the array panel DPS at the same time.

For this purpose, the bonding between the bonding layer 143 and the lens LS can be designed to be greater than the bonding between the lens LS and the die ST. The bonding between the micro light-emitting diode ED1 and the lens LS can be designed to be greater than the bonding between the lens LS and the die ST.

Figures 8a to 8c are diagrams describing a method for manufacturing a display device 100-1 according to an embodiment of the present invention.

Referring to FIG. 8a, the lens LS described above with reference to FIG. 7a to FIG. 7d can be formed in the concave portion CR of the die ST. Then, the connection lines W1 and W2 can be formed in the lens LS. The connection lines W1 and W2 can be made of transparent conductive oxides, transparent polymers, metals, etc. The connection lines W1 and W2 can be formed by using existing methods known in the art related to the present invention.

8b, the micro LED ED1 ' can first be transferred to the lens LS of the die ST. The micro LED ED1 ' can be initially transferred from the wafer on which the micro LED ED1 ' is formed to the lens LS by a laser stripping process or a chemical stripping process.

Referring to FIG. 8c, the micro-LED ED1 ' , the connecting wires W and the lens LS can then be transferred from the die ST to the array panel DPS.

After the adhesive layer 143 and the conductive adhesive layer 141 are coated on the array panel DPS, the stamp ST can be aligned and a suitable transfer pressure can be applied. Therefore, the lens LS, the micro light-emitting diode ED1 ' and the connecting lines W1, W2 can be transferred to the array panel DPS at the same time.

For this purpose, the adhesion between the lens LS and the die ST can be designed to be smaller than the adhesion between the adhesive layer 143 and the lens LS. Furthermore, the adhesion between the micro light emitting diode ED1 ' and the lens LS can be designed to be larger than the adhesion between the lens LS and the die ST.

The display device and the manufacturing method thereof according to the embodiment of the present invention are described as follows.

The display device according to the embodiment of the present invention 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 including an opening disposed on the first electrode and the second electrode; a micro-light-emitting diode disposed inside 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.

According to some embodiments of the present invention, the adhesive layer inside the opening surrounds the side surface of the micro-LED.

According to some embodiments of the present invention, the first electrode and the second electrode can be exposed through the opening, and the micro-LED can be disposed on the first electrode and the second electrode in a flip-chip type, wherein the n-side electrode and the p-side electrode are disposed downward.

According to some embodiments of the present invention, 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 an insulating layer; and a first connection line and a second connection line disposed on the lower surface of the lens.

According to some embodiments of the present invention, the micro-LED can be arranged in a horizontal chip type inside the opening, wherein the n-side electrode and the p-side electrode are arranged upward. The p-side electrode of the micro-LED can be connected to the first electrode via a first connecting line and a first connecting electrode, and the n-side electrode of the micro-LED can be connected to the second electrode via a second connecting line and a second connecting electrode.

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

According to some embodiments of the present invention, the first electrode can be exposed through the opening. The micro-LED can be arranged in a vertical chip arrangement inside the opening, wherein the n-side electrode is arranged upward and the p-side electrode is arranged downward. The p-side electrode of the micro-LED can be connected to the first electrode, and the n-side electrode of the micro-LED can be connected to the second electrode via a connecting line and a connecting electrode.

The display device manufacturing method according to the embodiment of the present invention may include forming a die having a concave portion; forming a lens in the concave portion; initially transferring the micro-LED to the lens; preparing an array substrate on which an adhesive layer is coated on each sub-pixel; and then transferring the lens together with the micro-LED to the array substrate.

According to some embodiments of the present invention, the manufacturing method of the display device may further include forming a connecting circuit on the lens after forming the lens in the concave portion.

According to some embodiments of the present invention, the connection line may include at least one first connection line and at least one second connection line separated from each other.

According to some embodiments of the present invention, the die can be made of polymethylsiloxane and the lens can be made of acrylic resin.

According to some embodiments of the present invention, the bonding between the adhesive layer and the lens can be greater than the bonding between the lens and the die.

The display device according to the embodiment of the present invention 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, and including an opening; a micro-light-emitting diode, disposed inside the opening of the bank layer; a high refractive index layer, disposed on the micro-light-emitting diode; an outer coating layer, disposed on the high refractive index layer and having a lower refractive index than the high refractive index layer; and an adhesive layer, disposed between the lens and the insulating layer.

According to some embodiments of the present invention, the fixing member surrounds the side surface of the micro-LED inside the opening.

According to some embodiments of the present invention, the first electrode and the second electrode can be exposed by openings, and the micro-LED can be mounted in the first electrode and the second electrode in a flip-chip arrangement, in which the n-side electrode and the p-side electrode are arranged downward.

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

According to some embodiments of the present invention, the micro-LED can be arranged inside the opening in a horizontal chip arrangement, in which the n-side electrode and the p-side electrode are arranged downward, the p-side electrode of the micro-LED can be connected to the first electrode via a first connecting line and a first connecting electrode, and the n-side electrode of the micro-LED can be connected to the second electrode via a second connecting line and a second connecting electrode.

The display device according to the embodiment of the present invention 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 pixels; a micro-light-emitting diode disposed in each of a plurality of pixels; and a connecting electrode passing through 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 connecting electrode and an upper portion electrically connected to the second electrode via the connecting electrode.

According to some embodiments of the present invention, the micro-LED can be in the form of a vertical chip.

According to some embodiments of the present invention, the upper portion can be electrically connected to the connecting electrode via a connecting line.

According to some embodiments of the present invention, the micro-LED can be disposed on the reflective layer in the opening of the bank layer.

According to some embodiments of the present invention, the micro-LED may include an n-side electrode disposed upward and a p-side electrode disposed downward.

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

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

According to some embodiments of the present invention, the micro light-emitting diode may further include: an active layer having a single quantum well (SQW) structure or a multiple 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.

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

According to some embodiments of the present invention, the display device may further include an outer coating layer disposed on the high refractive index layer and having a lower refractive index than the high refractive index layer.

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

According to some embodiments of the present invention, the high refractive index layer may include a lens.

The display device according to the embodiment of the present invention may include: a substrate, a first electrode and a second electrode are arranged on the substrate; a bank layer, which is arranged on the first electrode and the second electrode and includes an opening; a micro-light-emitting diode, which is arranged inside the opening of the bank layer; a high refractive index layer, which is arranged on the micro-light-emitting diode; an outer coating layer, which is arranged on the high refractive index layer and has a lower refractive index than the high refractive index layer; and a fixing member, which is arranged between the high refractive index layer and the bank layer.

Although the present invention has been described with reference to exemplary illustrations, it should be understood that the present invention is not limited to the embodiments and drawings herein, and that a person skilled in the art will understand that various modifications are possible without departing from the scope of the present invention. Furthermore, although the efficacy of the operation according to the configuration of the present invention is not explicitly described while describing the embodiments of the present invention, it should be understood that the expected efficacy is also identified by the configuration.

100: Display device

131: First electrode

133: Second electrode

135: Insulation layer

141: Conductive adhesive layer

143: Adhesive layer

2-2: Line

ED1: Micro LED

OP: Open mouth

LS: Lens

Claims (12)

A display device comprises: 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 comprising an opening (OP); a micro light-emitting diode (ED2) disposed inside the opening of the bank layer. ; a high refractive index layer (LS) disposed on the micro-LED; an outer coating layer (151) disposed on the high refractive index layer and having a lower refractive index than the high refractive index layer; and a fixing member (143) disposed between the high refractive index layer and the bank layer, wherein the first electrode (131) is exposed by a bank opening (OC). The display device as described in claim 1 further comprises: a connecting electrode (139) connected to the second electrode (133) through the bank layer (135). The display device as described in claim 2 further comprises: a virtual connecting electrode (139') disposed on the bank layer (135). The display device as described in claim 3 further comprises: a plurality of connection lines (W) disposed on a lower surface of the high refractive index layer (LS). A display device as described in claim 1, wherein the micro light-emitting diode (ED2) is arranged inside the bank opening (OC) in a vertical chip arrangement, in which an n-side electrode (240) is arranged upward and a p-side electrode (250) is arranged downward. A display device as described in claim 5, wherein the p-side electrode (250) of the micro light-emitting diode (ED2) is connected to the first electrode (131). A display device as described in claim 6, wherein the n-side electrode (240) of the micro-light-emitting diode (ED2) is connected to the second electrode (133) via the connecting lines (W) and the connecting electrode (39'). A display device as described in claim 1, wherein a protective film (155) is disposed on the outer coating (151). A display device as described in claim 1, wherein the fixing member (143) surrounds the connecting lines (W). A display device as described in claim 1, wherein the first electrode (131) is connected to a driving chip. A display device as described in claim 1, wherein the bank layer (135) includes a black pigment. A display device as described in any one of claims 8 to 11, wherein an 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.