Display device and manufacturing method for the same

Abstract

To provide a display device whose manufacturing process can be simplified, and a manufacturing method for the same.SOLUTION: A display device includes 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 and including an opening, a micro-light-emitting diode ED1 disposed in the opening of the bank layer, a high-refractive index layer LS1 disposed on the micro-light-emitting diode, an overcoat layer 151 disposed on the high-refractive index layer and having a lower refractive index than the high-refractive index layer, and a fixed member 143 disposed between the high-refractive index layer and the bank layer.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a display device and a method for manufacturing the same, and more particularly, to a display device and a method for manufacturing the same that can simplify the manufacturing process.

Background Art

[0002] As flat panel display devices, a liquid crystal display apparatus and an organic light emitting display apparatus are being utilized.

[0003] The organic light emitting display apparatus has advantages such as improved luminous efficiency, fast response speed, and wide viewing angle compared to the liquid crystal display apparatus. However, the organic light emitting display apparatus still has low luminous efficiency, and since it contains organic substances, it is vulnerable to moisture and its reliability and lifespan can decrease.

[0004] Recently, a micro light emitting diode display apparatus, which is an inorganic light emitting display apparatus, has been proposed.

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

Summary of the Invention

Problems to be Solved by the Invention

[0006] For improving the light extraction efficiency and adjusting the viewing angle of the display device, a geometric pattern such as a lens may be arranged on the micro light emitting diode.

[0007] In this case, after performing a transfer process and an electrode connection process of the micro light-emitting diode or the like, a substance for forming a lens is applied, and the lens is formed by performing an exposure process. By performing the exposure process for forming the lens, there is a problem that the manufacturing process of the display device is complicated and the manufacturing cost increases.

[0008] Therefore, the inventors of the present invention have invented a manufacturing process of a display device that transfers a micro light-emitting diode and a lens simultaneously.

[0009] An object to be solved by an embodiment of the present invention is to provide a display device and a manufacturing method thereof capable of simplifying the manufacturing process.

[0010] An object to be solved by an embodiment of the present specification is not limited to the problems mentioned above, and other problems not mentioned can be clearly understood by a person skilled in the art from the following description.

Means for Solving the Problem

[0011] A display device according to an embodiment of the present specification 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 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.

[0012] A method for manufacturing a display device according to an embodiment of the present specification includes a step of forming a stamp having recesses, a step of forming lenses in the recesses, a step of primarily transferring micro light-emitting diodes to the lenses, a step of preparing an array substrate coated with an adhesive layer for each sub-pixel, and a step of secondarily transferring the lenses and the micro light-emitting diodes together to the array substrate.

[0013] Specific matters of other embodiments are included in the detailed description and the drawings.

Advantages of the Invention

[0014] According to the embodiments of this specification, the lens and the micro light-emitting diode can be simultaneously mounted on the array panel by a single transfer process. Therefore, different from the conventional manufacturing process of applying a substance for forming the lens and performing an exposure process to form the lens, the exposure process for forming the lens is unnecessary, so the manufacturing method of the display device can be simplified and the manufacturing cost can be reduced.

[0015] The lens having a curved upper surface is arranged for each micro light-emitting diode, so that the light extraction efficiency of the micro light-emitting diode can be improved. Therefore, the display device can be driven with low power.

[0016] The effects of this specification are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the following description.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7a

Figure 7b

Figure 7c

Figure 7d

Figure 7e

Figure 7f

Figure 8a

Figure 8b

Figure 8c

Embodiments for Carrying Out the Invention

[0018] The advantages and features of the present specification, and the methods for achieving them, will become clear by referring to the embodiments described in detail below together with the accompanying drawings. However, the present specification is not limited to the embodiments disclosed below, but can be embodied in various different forms. However, this embodiment is provided to complete the disclosure of the present specification and to fully inform those with ordinary knowledge in the technical field to which the present specification pertains of the scope of the invention.

[0019] The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of the present specification are exemplary, and the present specification is not limited to the matters shown in the drawings. The same reference signs throughout the specification refer to the same components. Also, in explaining the present specification, when a specific explanation of related known technologies is determined to obscure the gist of the present specification, the detailed description thereof will be omitted. When terms such as "including", "having", "becoming", etc. mentioned in the present specification are used, other parts can be added unless "only" is used. When a component is indicated in the singular, it includes the case of including a plurality unless otherwise explicitly stated.

[0020] In interpreting the components, even if there is no separate explicit description, it shall be interpreted as including the error range.

[0021] In the case of the description regarding the positional relationship, for example, when describing the positional relationship between both parts such as "on ~", "above ~", "below ~", "on the side of ~", etc., unless "immediately" or "directly" is used, one or more other parts may be located between both parts.

[0022] In the case of the description regarding the time relationship, for example, when describing the sequence of time such as "after ~", "subsequent to ~", "next to ~", "before ~", etc., unless "immediately" or "directly" is used, it may include cases where they are not continuous.

[0023] First, second, etc. are used to describe various components, but these components are not limited by these terms. These terms are merely used to distinguish one component from another. Therefore, the first component mentioned below may be the second component within the technical idea of this specification.

[0024] The features of the multiple embodiments of this specification can be combined or combined with each other partially or wholly, and various linkages and drives are technically possible. Each embodiment can be implemented independently of each other or can be implemented together in an associated relationship.

[0025] Hereinafter, a display device and a manufacturing method thereof according to an embodiment of the present invention will be described.

[0026] FIG. 1 is a plan view showing a display device 100 according to an embodiment of this specification. FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1. In FIGS. 1 and 2, a region corresponding to one sub-pixel of the display device 100 is shown.

[0027] Referring to FIGS. 1 and 2, a display device 100 according to an embodiment of the present invention 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).

[0028] 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).

[0029] The substrate 110 can be made of glass or plastic. For example, as the 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), or cyclic olefin copolymer (COC), triacetyl cellulose (TAC) film, polyvinyl alcohol (PVA) film, polystyrene (PS), etc. can be used, but it is not limited thereto.

[0030] The thin-film transistor 120 is composed of 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 electrode 124 and a source electrode 125 connected to the semiconductor layer 121.

[0031] The gate electrode 123 may be a single layer or a multilayer made of a metal such as Cr, Mo, Ta, Cu, Ti, Al, or an alloy thereof, or may be a conductive compound such as a metal nitride or other conductive material such as doped polycrystalline silicon. The gate insulating layer 122 may be composed of a single layer or a multilayer of an inorganic insulating material such as silicon oxide, silicon nitride, or silicon oxynitride. The semiconductor layer 121 can also be composed of a silicon semiconductor such as amorphous silicon or polycrystalline silicon, and can be composed of a metal oxide such as zinc (Zn), indium (In), gallium (Ga), tin (Sn), titanium (Ti), or a combination of a metal such as zinc (Zn), indium (In), gallium (Ga), tin (Sn), titanium (Ti) and its oxide. Specifically, the oxide semiconductor may include, but is not limited to, zinc oxide (ZnO), zinc oxide-tin (ZTO), zinc oxide-indium (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). The drain electrode 124 and the source electrode 125 may be a single layer or a multilayer of a metal such as Au, W, Pt, Si, Ir, Ag, Cu, Ni, Cr, Mo, Ta, Cu, Ti, Al, or an alloy thereof, or other conductive material.

[0032] The thin film transistor is not limited to the structure shown in FIG. 2, and thin film transistors with various structures can be applied. For example, the thin film transistor may have a bottom gate structure.

[0033] In this specification, the thin film transistor can also be named with any of the terms driving part, driving driver, and driving chip.

[0034] In addition, the thin film transistor according to this specification can drive one micro light emitting diode (ED1), but is not limited thereto, and can also drive a plurality of micro light emitting diodes (ED1).

[0035] The drain electrode 124 and the source electrode 125 can penetrate through the interlayer insulating layer 127 covering the gate electrode 123 and the semiconductor layer 121 and be respectively connected to the semiconductor layer 121. The interlayer insulating layer 127 may be composed of a single layer or multiple layers of inorganic insulating materials such as silicon oxide, silicon nitride, or silicon oxynitride.

[0036] A first planarization layer 129 may be disposed on the thin film transistor 120 and the interlayer insulating layer 127. The first planarization layer 129 may be made of an organic insulating material such as acrylic resin, epoxy resin, phenolic resin, polyamide resin, unsaturated polyester resin, polyphenylene resin, polyphenylene sulfide resin, benzocyclobutene, polyacrylate, polyimide, etc., but is not limited thereto.

[0037] On the first planarization layer 129, a first electrode 131 connected to the drain electrode 124 of the thin film transistor 120 may be disposed through the first planarization layer 129 or via a connection structure such as a connection via directly or coupled to the first electrode 131. A second electrode 133 spaced apart from the first electrode 131 may be disposed on the first planarization layer 129. The second electrode 133 can be connected to a low potential wiring or a ground wiring.

[0038] 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, Cu, Ni, Cr, Mo, Ta, Cu, Ti, Al, or an alloy thereof.

[0039] The insulating layer 135 having an opening (OP) that exposes a part of the first electrode 131 and a part 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, or silicon oxynitride.

[0040] In this specification, the insulating layer 135 may also be named a bank layer.

[0041] Therefore, the insulating layer 135 can be a pixel definition layer or a sub-pixel definition layer that defines a plurality of pixels or sub-pixels.

[0042] Furthermore, the bank layer may be a black bank layer.

[0043] A 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.

[0044] A micro light-emitting diode (ED1) may be disposed within the opening (OP) of the insulating layer 135. A micro light-emitting diode (ED1) may be disposed on the first electrode 131 and the second electrode 133. The micro light-emitting diode (ED1) can be transferred onto the substrate 110 after being fabricated by a separate manufacturing process.

[0045] The micro light-emitting diode (ED1) can be flip-chip mounted on the first electrode 131 and the second electrode 133 by the conductive adhesive layer 141.

[0046] The micro light-emitting diode (ED1) can be formed, for example, to have a size of about 10 - 100 μm (e.g., 50 μm), but is not limited thereto. The micro light-emitting diode (ED1) can be formed using a group III-V compound semiconductor such as GaP, GaAs, GaSb, InP, InAs, and / or InSb, or a group II-VI compound semiconductor such as CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, HgS, HgTe, and / or a combination thereof, but is not limited thereto.

[0047] 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 multi quantum well (MQW) structure disposed on the n-type semiconductor layer 210, 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 in contact with the n-type semiconductor layer 210 in a region where the active layer 220 and the p-type semiconductor layer 230 are partially removed. And the micro light-emitting diode (ED1) may include a passivation film 260 covering the side and upper surfaces of the p-type semiconductor layer 230.

[0048] The n-type semiconductor layer 210 is a layer for supplying electrons to the active layer 220. The n-type semiconductor layer 210 can be formed, for example, by doping GaN with n-type impurities such as arsenic (As), phosphorus (P), antimony (Sb), germanium (Ge), tin (Sn), and silicon (Si).

[0049] The active layer 220 is a layer in which electrons and holes are combined to generate light. The active layer 220 may include, for example, at least one well layer made of InGaN and at least one barrier layer made of GaN, but is not limited thereto.

[0050] The p-type semiconductor layer 230 is a layer for injecting holes into the active layer 220. The p-type semiconductor layer 230 may be formed by doping p-type impurities such as indium (In), aluminum (Al), boron (B), gallium (Ga), magnesium (Mg), and zinc (Zn) into, for example, GaN.

[0051] The p-side electrode 250 and the n-side electrode 240 can be composed of a single layer or a plurality of layers made of at least one metal among W, Si, Ir, Ag, C, Ni, Au, Pt, Ti, Al, 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 a transparent metal oxide such as ITO (Indium Tin Oxide), IGZO (Indium Galium Zinc Oxide), and IZO (Indium Zinc Oxide).

[0052] The lens (LS) may be directly disposed on the micro light-emitting diode (ED1). The lens (LS) can have an area larger than that of the micro light-emitting diode (ED1) so as to completely cover the micro light-emitting diode (ED1). The upper surface of the lens (LS) may be a convex curved surface. The lens (LS) may be made of a transparent organic substance. The lens (LS) may be made of, for example, an acrylic resin or poly(3,4-ethylenedioxythiophene), PEDOT. The lens (LS) is disposed within one sub-pixel and may be disposed one by one for each micro light-emitting diode (ED1).

[0053] In the present embodiment, the lower surface of the lens (LS) may be directly attached to the micro light-emitting diode (ED1) by the self-adhesive force of the lens (LS). The micro light-emitting diode (ED1) and the lens (LS) can be simultaneously mounted on the array panel (DPS) by a single transfer process.

[0054] Therefore, unlike the conventional manufacturing process of forming a lens by applying a substance for forming the lens and performing an exposure process, since an exposure process for forming the lens is unnecessary, the manufacturing method of the display device 100 can be simplified and the manufacturing cost can be reduced.

[0055] An adhesive layer 143 may be disposed between the lens (LS) and the insulating layer 135. The adhesive layer 143 is also disposed within the opening (OP) of the insulating layer 135 and can surround the side surface of the micro light-emitting diode (ED1). In some embodiments, the lens (LS) includes dimensions in the X-axis and / or Y-axis that are larger than the dimensions of the micro light-emitting diode (ED1) in 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, further fixing the lens (LS) and the micro light-emitting diode (ED1) to the array panel (DPS). Further, the micro light-emitting diode (ED1) extends in the Z-axis direction beyond the insulating layer 135, and a space 136 exists between the lens and the upper surface 138 of the insulating layer 135. The space 136 can be filled with the adhesive layer 143. The adhesive layer 143 enables the lens (LS) and the micro light-emitting diode (ED1) to be reliably mounted on the array panel (DPS).

[0056] In this specification, the adhesive layer 143 can also be named a fixing member.

[0057] For example, the fixing member may include photo acryl (PAC).

[0058] On the other hand, the adhesive layer 143 may further include particles of a light diffuser for diffusing light.

[0059] For example, the particles of the light diffusing agent 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.

[0060] A 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 an acrylic resin or a transparent organic material such as poly(3,4-ethylenedioxythiophene), PEDOT. The second planarization layer 151 may have a refractive index lower than that of the lens (LS).

[0061] 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.

[0062] In this specification, the second planarization layer 151 may also be named an overcoat layer (OC).

[0063] By disposing a lens (LS) having an upper surface of a curved surface for 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 driven at low power.

[0064] A protective film 155 may be disposed on the second planarization layer 151. At least one of an antireflection layer, an antiglare layer, and a fingerprint prevention layer may be coated on the upper surface of the protective film 155.

[0065] FIG. 3 is a plan view showing a display device 100-1 according to an embodiment of the present specification. FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. 3. FIGS. 3 and 4 show a region corresponding to one sub-pixel of the display device 100-1.

[0066] Referring to FIGS. 3 and 4, the display device 100-1 may include a first connection electrode 137 that penetrates the insulating layer 135 and is connected to the first electrode 131, and a second connection electrode 139 that penetrates the insulating layer 135 and is connected to the second electrode 133. A conductive adhesive layer 141 may be disposed on the first connection electrode 137 and the second connection electrode 139.

[0067] The micro light-emitting diode (ED1’) can be mounted in the opening (OP) of the insulating layer 135 in a horizontal chip shape 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 within the opening (OP). The reflective layer 140 may be disposed on the first planarization layer 129. The reflective layer 140 may contain a metal with a high visible light reflectance, such as aluminum (Al), silver (Ag), gold (Au), molybdenum (Mo), or magnesium (Mg).

[0068] A lens (LS) on which a first connection wiring (W1) and a second connection wiring (W2) are formed may be directly disposed on the micro light-emitting diode (ED1’). Although three each of the first connection wiring (W1) and the second connection wiring (W2) are shown to be arranged, this is exemplary, and other numbers of the first connection wiring (W1) and the second connection wiring (W2) can also be arranged. The first and second connection wirings (W1, 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) or copper (Cu). The first and second connection wirings (W1, W2) can be formed using methods known in the art.

[0069] 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 (ED1') by the self-adhesive force of the lens (LS). The micro light-emitting diode (ED1') and the lens (LS) can be simultaneously mounted on the array panel (DPS) by a single transfer process.

[0070] Therefore, unlike the conventional manufacturing process of applying a substance for forming a lens and performing an exposure process to form a lens, an exposure process for forming a lens is unnecessary, so the manufacturing method of the display device 100-1 can be simplified, and the manufacturing cost can be reduced.

[0071] An adhesive layer 143 may be disposed between the lens (LS) and the insulating layer 135. The adhesive layer 143 can surround the first connection electrode 137, the second connection electrode 139, and the conductive adhesive layer 141, and is also disposed within the opening (OP) of the insulating layer 135 to surround the micro light-emitting diode (ED1'). With the adhesive layer 143, the lens (LS) and the micro light-emitting diode (ED1') can be reliably mounted on the array panel (DPS).

[0072] The first connection wiring (W1) can be connected to the first connection electrode 137 by the conductive adhesive layer 141, and the second connection wiring (W2) can be connected to the second connection electrode 139 by the conductive adhesive layer 141.

[0073] The p-side electrode 250 of the micro light-emitting diode (ED1') can be connected to the first electrode 131 through the first connection wiring (W1), the conductive adhesive layer 141, and the first connection electrode 137. And the first electrode 131 can be connected to the drain electrode 124 of the thin film transistor 120.

[0074] The n-side electrode 240 of the micro light-emitting diode (ED1’) can be connected to the second electrode 133 via the second connection wiring (W2) and the second connection electrode 139. And the second electrode 133 can be connected to a low-potential wiring or a ground wiring.

[0075] The lens (LS) having an upper surface of a curved surface is arranged for each micro light-emitting diode (ED1), so that the light extraction efficiency of the micro light-emitting diode (ED1’) can be improved. Therefore, the display device 100-1 can be driven at low power.

[0076] A second planarization layer 151 and a protective film 155 may be arranged on the lens (LS).

[0077] FIG. 5 is a plan view showing a display device 100-2 according to an embodiment of the present specification. FIG. 6 is a cross-sectional view taken along line 6-6 of FIG. 5. In FIGS. 5 and 6, a region corresponding to one sub-pixel of the display device 100-2 is shown.

[0078] Referring to FIGS. 5 and 6, the display device 100-2 may include a first electrode 131 extending within an opening (OP) of the insulating layer 135 and a connection electrode 139 penetrating the insulating layer 135 and connected to the second electrode 133. The second electrode 133 may be at least partially covered by the insulating layer 135. And a dummy connection electrode 139’ may be arranged on the insulating layer 135 spaced apart from the opposite side of the connection electrode 139. In one embodiment, the dummy connection electrode 139’ can be electrically connected to the connection electrode 139 via a connection wiring described later. By arranging the dummy connection electrode 139’ on the opposite side of the connection electrode 139, the levels of the lens (LS) and the micro light-emitting diode (ED2) can be maintained.

[0079] A conductive adhesive layer 141 may be arranged on the second connection electrode 139 and the dummy connection electrode 139’. A conductive adhesive layer 141 may also be arranged on the first electrode 131.

[0080] Although not shown in FIG. 6, the micro light-emitting diode (ED2) may be disposed on the reflective layer within the opening (OP). Although the reflective layer 140 may be disposed on the first planarization layer 129, it is not limited thereto and may be disposed below the first planarization layer 129.

[0081] The micro light-emitting diode (ED2) can be mounted in the opening (OP) of the insulating layer 135 in a vertical chip shape such that the n-side electrode 240 faces upward and the p-side electrode 250 faces downward. A lens (LS) having a connection wiring (W) formed thereon may be directly disposed on the micro light-emitting diode (ED2). Although three connection wirings (W) are shown to be disposed, this is exemplary and other numbers of connection wirings (W) may be disposed. The connection wiring (W) may be made of a transparent conductive oxide, a transparent conductive polymer, a metal, or the like. The connection wiring (W) can be formed using methods known in the art.

[0082] In the present embodiment, at least a part of the lower surface of the lens (LS) may be directly attached to the micro light-emitting diode (ED2) by the self-adhesive force of the lens (LS). The lens (LS) having the connection wiring (W) formed thereon and the micro light-emitting diode (ED2) can be simultaneously mounted on the array panel (DPS) by a single transfer process.

[0083] Therefore, different from the conventional manufacturing process of applying a substance for forming a lens and performing an exposure process to form the lens, an exposure process for forming the lens and the like are unnecessary, so the manufacturing method of the display device 100-2 can be simplified and the manufacturing cost can be reduced.

[0084] An adhesive layer 143 may be disposed between the lens (LS) and the insulating layer 135. The adhesive layer 143 can surround the connection electrode 139, the dummy connection electrode 139', and the conductive adhesive layer 141, and is also disposed within the opening (OP) of the insulating layer 135 to surround the micro light-emitting diode (ED2). With the adhesive layer 143, the lens (LS) and the micro light-emitting diode (ED2) can be reliably mounted on the array panel (DPS).

[0085] The adhesive layer 143 may be a transparent adhesive layer containing a transparent substance.

[0086] For example, the adhesive layer 143 may contain an optically clear resin (OCR), but is not limited thereto.

[0087] The connection wiring (W) can be connected to the connection electrode 139 and the dummy connection electrode 139' by the conductive adhesive layer 141.

[0088] The p-side electrode 250 of the micro light-emitting diode (ED2) can be connected to the first electrode 131 by the conductive adhesive layer 141. And the first electrode 131 can be connected to the drain electrode 124 of the thin-film transistor 120.

[0089] The n-side electrode 240 of the micro light-emitting diode (ED2) can be connected to the second electrode 133 through the connection wiring (W) and the connection electrode 139. And the second electrode 133 can be connected to a low-potential wiring or a ground wiring.

[0090] By disposing a lens (LS) having an upper surface of a curved surface for 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 driven with low power.

[0091] A second planarization layer 151 and a protective film 155 may be disposed on the lens (LS).

[0092] Figures 7a to 7f are drawings for explaining a method of manufacturing the display device 100 according to an embodiment of the present specification.

[0093] Referring to FIG. 7a, a mold (MD) including a convex portion (CP) having a convex surface is manufactured. The convex portion (CP) can have a shape corresponding to the shape of a lens (LS) to be formed in a subsequent process. The mold (MD) can be manufactured using a method known in the art.

[0094] A stamp (ST) is coated on the mold (MD). The stamp (ST) may be made of, for example, a silicone rubber such as polydimethylsiloxane (PDMS), or an elastomer such as polyurethane (Pu) and polytetrafluoroethylene (PTFE).

[0095] Referring to FIG. 7b, a substrate (SS) is attached to the stamp (ST). An adhesive layer may further be included between the substrate (SS) and the stamp (ST). The adhesive layer can use a material known in the art. Specifically, although a pressure-sensitive adhesive (PSA) can be used, it is not limited thereto, and it may be made of an optically transparent adhesive (OCA), an optically transparent resin (OCR), or the like.

[0096] Referring to FIG. 7c, the mold (MD) is removed from the stamp (ST). As a result, a concave portion (CR) having a shape corresponding to the shape of the lens (LS) may be formed in the stamp (ST).

[0097] Referring to FIG. 7d, a lens (LS) can be formed in the concave portion (CR) of the stamp (ST). The lens (LS) can be formed by coating the concave portion (CR) with an acrylic resin or poly(3,4-ethylenedioxythiophene), PEDOT, or the like.

[0098] Referring to FIG. 7e, a micro light-emitting diode (ED1) may be primarily transferred to the lens (LS) of the stamp (ST).

[0099] From the wafer on which the micro light-emitting diode (ED1) is formed, the micro light-emitting diode (ED1) may be disposed on the carrier substrate (or donor substrate) by a laser lift-off process or a chemical lift-off process. The micro light-emitting diode (ED1) may be primarily transferred to the lens (LS) from the carrier substrate (or donor substrate) on which the micro light-emitting diode (ED1) is disposed.

[0100] Referring to FIG. 7f, the micro light-emitting diode (ED1) and the lens (LS) may be secondarily transferred together from the stamp (ST) to the array panel (DPS).

[0101] After coating the adhesive layer 143 and the conductive adhesive layer 141 on the array panel (DPS), the stamp (ST) is aligned with the array panel (DPS), and by applying an appropriate transfer pressure, the lens (LS) and the stamp (ST) can be simultaneously transferred together to the array panel (DPS).

[0102] For this purpose, the adhesive force between the adhesive layer 143 and the lens (LS) can be designed to be greater than the adhesive force between the lens (LS) and the stamp (ST). And the adhesive force between the micro light-emitting diode (ED1) and the lens (LS) can be designed to be greater than the adhesive force between the lens (LS) and the stamp (ST).

[0103] FIGS. 8A to 8C are drawings for explaining a manufacturing method of the display device 100-1 according to an embodiment of the present specification.

[0104] Referring to FIG. 8A, as described with reference to FIGS. 7A to 7D, the lens (LS) can be formed in the concave portion (CR) of the stamp (ST). Then, the connection wirings (W1, W2) may be formed on the lens (LS). The connection wirings (W1, W2) may be made of a transparent conductive oxide, a transparent conductive polymer, a metal, or the like. The connection wirings (W1, W2) can be formed using a method known in the art.

[0105] Referring to FIG. 8b, the micro light emitting diode (ED1') may be primarily transferred to the lens (LS) of the stamp (ST). The micro light emitting diode (ED1') may be primarily transferred to the lens (LS) from the wafer on which the micro light emitting diode (ED1') is formed by a laser lift-off process or a chemical lift-off process.

[0106] Referring to FIG. 8c, the micro light emitting diode (ED1') and the lens (LS) may both be secondarily transferred from the stamp (ST) to the array panel (DPS).

[0107] After coating the adhesive layer 143 and the conductive adhesive layer 141 on the array panel (DPS), the stamp (ST) is aligned with the array panel (DPS), and an appropriate transfer pressure is applied, so that the lens (LS), the connection wirings (W1, W2), and the micro light emitting diode (ED1') may be simultaneously transferred to the array panel (DPS) together.

[0108] For this purpose, the adhesive force between the adhesive layer 143 and the lens (LS) can be designed to be greater than the adhesive force between the lens (LS) and the stamp (ST). And the adhesive force between the micro light emitting diode (ED1') and the lens (LS) can be designed to be greater than the adhesive force between the lens (LS) and the stamp (ST).

[0109] The display device 100-2 according to an embodiment of the present specification can be manufactured by a manufacturing method similar to the above.

[0110] The display device and its manufacturing method according to the embodiment of the present specification can be described as follows.

[0111] The display device according to the embodiment of the present specification 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 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.

[0112] According to some embodiments of the present specification, the adhesive layer can surround the side surface of the micro light-emitting diode within the opening of the insulating layer.

[0113] According to some embodiments of the present specification, the first electrode and the second electrode are exposed by the opening, and the micro light-emitting diode can be mounted on the first electrode and the second electrode in a flip-chip type with the n-side electrode and the p-side electrode facing downward.

[0114] According to some embodiments of the present specification, the display device may further include a first connection electrode connected to the first electrode through the insulating layer, a second connection electrode connected to the second electrode through the insulating layer, and first connection wirings and second connection wirings disposed on the lower surface of the lens.

[0115] According to some embodiments of the present specification, the micro light-emitting diode is disposed in the opening in a horizontal chip shape with the n-side electrode and the p-side electrode facing upward, and the p-side electrode of the micro light-emitting diode is connected to the first electrode through the first connection wirings and the first connection electrode, and the n-side electrode of the micro light-emitting diode may be connected to the second electrode through the second connection wirings and the second connection electrode.

[0116] According to some embodiments of the present specification, the display device may further include a connection electrode connected to the second electrode through the insulating layer, a dummy connection electrode disposed on the insulating layer, and connection wirings disposed on the lower surface of the lens.

[0117] According to some embodiments of this specification, the first electrode is exposed by the opening, and the micro light-emitting diode is disposed in the opening in a vertical chip shape with the n-side electrode facing upward and the p-side electrode facing downward. The p-side electrode of the micro light-emitting diode is connected to the first electrode, and the n-side electrode of the micro light-emitting diode may be connected to the second electrode via connection wirings and a connection electrode.

[0118] The method for manufacturing a display device according to an embodiment of this specification includes a step of forming a stamp having recesses, a step of forming lenses in the recesses, a step of primarily transferring micro light-emitting diodes to the lenses, a step of preparing an array substrate coated with an adhesive layer for each sub-pixel, and a step of secondarily transferring the lenses and the micro light-emitting diodes together to the array substrate.

[0119] According to some embodiments of this specification, the method for manufacturing a display device may further include a step of forming connection wirings on the lenses after the step of forming lenses in the recesses.

[0120] According to some embodiments of this specification, the connection wirings may include at least one first connection wiring spaced apart from each other and at least one second connection wiring.

[0121] According to some embodiments of this specification, the stamp may be made of polydimethylsiloxane, and the lenses may be made of an acrylic resin.

[0122] According to some embodiments of this specification, the adhesive force between the adhesive layer and the lenses may be greater than the adhesive force between the lenses and the stamp.

[0123] The display device according to the embodiment of the present specification 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 in the opening of the bank layer, a high refractive index layer disposed on the micro light-emitting diode, an overcoat layer disposed in 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 lens and the insulating layer.

[0124] The fixing member can surround the side surface of the micro light-emitting diode inside the opening.

[0125] The first electrode and the second electrode may be exposed by the opening, and the micro light-emitting diode can be mounted in a flip-chip form with the n-side electrode and the p-side electrode facing downward on the first electrode and the second electrode.

[0126] 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 wiring and a second connection wiring disposed on the lower surface of the high refractive index layer.

[0127] The micro light-emitting diode is disposed in the opening of the bank layer in the form of a horizontal chip with the n-side electrode and the p-side electrode facing upward, and the p-side electrode of the micro light-emitting diode is connected to the first electrode through the first connection wiring and the first connection electrode, and the n-side electrode of the micro light-emitting diode may be connected to the second electrode through the second connection wiring and the second connection electrode.

[0128] The display device according to the embodiment of the present specification 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 defining 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. The micro light-emitting diode may include a lower region electrically connected to the first electrode and an upper region electrically connected to the second electrode through the connection electrode.

[0129] The micro light-emitting diode may be in the form of a vertical chip.

[0130] The upper region of the micro light-emitting diode can be electrically connected to the connection electrode via a connection wiring.

[0131] The micro light-emitting diode can be disposed in the reflective layer within the opening of the bank layer.

[0132] The micro light-emitting diode may include an n-side electrode disposed above and a p-side electrode disposed below.

[0133] The micro light-emitting diode may further include an n-type semiconductor layer and a p-type semiconductor layer.

[0134] The micro light-emitting diode may further include a passivation layer covering the sides of the n-type semiconductor layer and the p-type semiconductor layer.

[0135] The micro light-emitting diode may further include an active layer having a single quantum well (SQW) structure or a multiple quantum well (MQM) 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.

[0136] The display device may further include a high refractive index layer disposed on the micro light-emitting diode.

[0137] The display device may further include an overcoat layer disposed on the high refractive index layer, and the overcoat layer has a refractive index lower than that of the high refractive index layer.

[0138] The display device may further include a fixing member disposed between the high refractive index layer and the bank layer.

[0139] The high refractive index layer may include a lens.

[0140] The display device according to an embodiment of the present specification further includes 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 in 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 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.

[0141] In the above, the embodiments of the present specification have been described in more detail with reference to the accompanying drawings. However, the present specification is not necessarily limited to these embodiments, and various modifications can be made within the scope not departing from the technical idea of the present specification. Therefore, the embodiments disclosed in the present specification are for the purpose of explanation and not for limiting the technical idea of the present specification, nor is the scope of the technical idea of the present specification limited by these embodiments. Therefore, it should be understood that the above-described embodiments are exemplary in all respects and not restrictive.

Explanation of Reference Numerals

[0142] DPS array substrate ED1, ED1’, ED2 micro light-emitting diodes LS lens W1, W2 connecting wirings 100, 100-1, 100-2 display devices 120 thin film transistors 141 conductive adhesive layer 143 adhesive layer

Claims

1. 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 in 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 refractive index lower than that of the high refractive index layer; and Including a fixing member disposed between the high refractive index layer and the bank layer, A display device.

2. Further including a connection electrode connected to the second electrode through the bank layer, The display device according to Claim 1.

3. Further including a dummy connection electrode disposed on the bank layer, The display device according to Claim 2.

4. Further including a connection wiring disposed on the lower surface of the high refractive index layer, The display device according to Claim 3.

5. The first electrode is exposed by the opening of the bank layer, The display device according to Claim 1.

6. The micro light-emitting diode is disposed in the opening of the bank layer in the form of a vertical chip in which the n-side electrode is disposed upward and the p-side electrode is disposed downward, The display device according to Claim 4.

7. The p-side electrode of the micro light-emitting diode is connected to the first electrode, The display device according to Claim 6.

8. The n-side electrode of the micro light-emitting diode is connected to the second electrode through the connection wiring and the connection electrode, The display device according to Claim 7.

9. A protective film is disposed on the overcoat layer, The display device according to Claim 1.

10. The fixing member surrounds the connection wiring, The display device according to Claim 4.

11. The first electrode is connected to a driving chip, The display device according to Claim 1.

12. The bank layer contains a black pigment, The display device according to Claim 1.

13. The upper surface of the protective film is coated with at least one of an antireflection layer, an antiglare layer, or a fingerprint prevention layer, The display device according to Claim 9.

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