Display apparatus
Patent Information
- Application Number
- KR1020250048136
- Authority / Receiving Office
- KR · KR
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2025-04-14
- Publication Date
- 2026-10-21
Smart Images
Figure PAT00002_ABST
Abstract
Description
Technology Field
[0001] This specification relates to a display device. Background Technology
[0002] As the information society develops, there is an increasing demand for display devices that display images, and various types of display devices, such as Liquid Crystal Display Apparatuses and Organic Light Emitting Diode Display Apparatuses, are being utilized.
[0003] Among display devices, organic light-emitting displays (OLEDs) are self-emissive and offer superior viewing angles and contrast ratios compared to liquid crystal displays (LCDs). Furthermore, they do not require a separate backlight, enabling lightweight and thin designs, and offer the advantage of lower power consumption. Additionally, OLEDs are capable of low-voltage operation, feature fast response speeds, and offer low manufacturing costs.
[0004] However, organic light-emitting display devices using organic materials are prone to defective pixels, such as oxidation between the organic light-emitting layer and the electrodes caused by the penetration of moisture and oxygen; therefore, various additional technical configurations are required to minimize the penetration of oxygen and moisture.
[0005] To address the aforementioned problems, research and development on display devices using inorganic LEDs (Light Emitting Diodes) as light-emitting elements have recently been underway. These light-emitting display devices are gaining attention as next-generation display devices because they possess high image quality and high reliability. The problem to be solved
[0006] The problem that this specification aims to solve is to provide a display device in which the electrical connection between the LED element and the connecting wiring is smooth.
[0007] Another problem that this specification aims to solve is to provide a display device with improved stability of the contact process with LED elements.
[0008] Another problem that this specification aims to solve is to provide a display device with improved light extraction efficiency.
[0009] The problems of this specification are not limited to those mentioned above, and other technical problems can be inferred from the following embodiments. means of solving the problem
[0010] A display device according to one embodiment of the present specification comprises a substrate, a transistor disposed on the substrate, a planarization layer disposed on the transistor, a first reflective electrode disposed on the planarization layer, a first adhesive layer disposed on the first reflective electrode, a light-emitting element disposed on the first adhesive layer, and a second reflective electrode in contact with the light-emitting element, wherein the first reflective electrode and the second reflective electrode are in direct contact.
[0011] A display device according to another embodiment of the present specification comprises a substrate, a transistor disposed on the substrate, a planarization layer disposed on the transistor, a first reflective electrode disposed on the planarization layer, a first adhesive layer disposed on the upper surface of the first reflective electrode, a light-emitting element disposed on the first adhesive layer, and a second reflective electrode disposed on the upper surface of the first reflective electrode, wherein the second reflective electrode is disposed to surround the first adhesive layer.
[0012] Specific details of other embodiments are included in the detailed description and drawings. Effects of the invention
[0013] According to the embodiments of the present specification, a display device with a smooth electrical connection with an LED element can be provided.
[0014] According to the embodiments of the present specification, a display device with improved stability of the contact process with an LED element can be provided.
[0015] According to the embodiments of the present specification, a display device with improved light extraction efficiency can be provided.
[0016] According to the embodiments of the present specification, as the light extraction efficiency of the display device is improved, low power consumption of the display device can be realized, and thus energy consumption can be reduced.
[0017] However, the effects obtainable in this specification are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art to which this specification belongs from the description below. Brief explanation of the drawing
[0018] FIG. 1 is a plan view of a display device according to one embodiment. FIG. 2 is a diagram showing the cross-sectional structure of a subpixel according to one embodiment. Figure 3 is an enlarged view of the Q1 region of Figure 2. Figure 4 is a schematic diagram showing the path of light emitted from the light-emitting layer. FIGS. 5 to 8 are drawings showing the manufacturing process of a display device according to one embodiment in steps. FIG. 9 is a cross-sectional view of a display device according to another embodiment. FIG. 10 is a cross-sectional view of a display device according to another embodiment. FIG. 11 is a cross-sectional view of a display device according to another embodiment. FIG. 12 is a cross-sectional view of a display device according to another embodiment. FIG. 13 is a cross-sectional view of a display device according to another embodiment. Figure 14 is an enlarged view of the Q2 area of Figure 13. FIG. 15 is a cross-sectional view of a display device according to another embodiment. Specific details for implementing the invention
[0019] Hereinafter, embodiments are described with reference to the drawings. In this specification, where a component (or region, layer, part, etc.) is described as being "on," "connected," or "joined" to another component, it means that it may be directly connected / joined to the other component or that a third component may be placed between them.
[0020] Identical reference numerals denote identical components. Additionally, in the drawings, the thicknesses, proportions, and dimensions of the components are exaggerated for the effective illustration of the technical content. "And / or" includes all of one or more combinations that the associated components may define.
[0021] Terms such as "first," "second," etc., may be used to describe various components, but said components are not limited by said terms. These terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the embodiments, the first component may be named the second component, and similarly, the second component may be named the first component. A singular expression includes a plural expression unless the context clearly indicates otherwise.
[0022] Terms such as "below," "lower side," "above," and "upper side" are used to describe the relationships between the components depicted in the drawings. These terms are relative concepts and are described based on the directions indicated in the drawings.
[0023] Terms such as "include" or "have" are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.
[0025] FIG. 1 is a plan view of a display device according to one embodiment.
[0026] Referring to FIG. 1, a display device (10) according to one embodiment of the present specification may be applied to a TV, signage, a mobile terminal such as a mobile phone or smartphone, a computer display such as a laptop or desktop, a head-up display (HUD) for automobiles, a backlight unit for a display, a display for VR, AR, or MR (mixed reality), etc. However, the configuration according to the embodiment described in the present specification may be applied in the same way to a device capable of display, even if it is a new product form developed in the future.
[0027] The display device (10) may use a micro LED as a display element, but is not limited thereto.
[0028] The display device (10) may include a flexible display fabricated on a thin and flexible substrate. The flexible display can be bent or rolled like paper while maintaining the characteristics of a conventional flat panel display.
[0029] The display device (10) may include a display area (DA) and a non-display area (NDA) where a plurality of pixels (PX) are arranged. The display device (10) may include a substrate (110) that provides a space where a plurality of pixels (PX) can be arranged.
[0030] The display area (DA) is an area for displaying images, video, and images, and may have multiple pixels (PX) arranged therein. The non-display area (NDA) is an area where the screen is not displayed and may be referred to as the bezel area. The non-display area (NDA) may be placed around the display area (DA), but is not limited thereto. The non-display area (NDA) may be placed to surround the display area (DA), but is not limited thereto.
[0031] The non-display area (NDA) can be defined as an area on the substrate (110) excluding the display area (DA), and may have a relatively narrow width (or size) compared to the display area (DA), but is not limited thereto.
[0032] A pixel (PX) may be composed of a plurality of subpixels (SP1, SP2, SP3), and each subpixel (SP1, SP2, SP3) may emit red, blue, and green light. However, it is not limited thereto and may include subpixels that emit light such as white. The subpixels (SP1, SP2, SP3) may be arranged sequentially along a first direction (DR1).
[0033] Pixels (PX) can be repeatedly arranged along a first direction (DR1) and a second direction (DR2). Specifically, each sub-pixel (SP1, SP2, SP3) can be repeatedly arranged alternately along the first direction (DR1). Each sub-pixel (SP1, SP2, SP3) can be repeatedly arranged along the second direction (DR2).
[0034] The display device (10) may further include a gate line (GL) and a data line (DL) electrically connected to the subpixels (SP1, SP2, SP3) of each pixel (PX). The gate line (GL) and the data line (DL) may provide the necessary signals to the subpixels (SP1, SP2, SP3) of each pixel (PX).
[0035] The gate line (GL) extends in a first direction (DR1) and can be repeatedly arranged along a second direction (DR2). The data line (DL) extends in a second direction (DR2) and can be repeatedly arranged along the first direction (DR1). The gate line (GL) and the data line (DL) can intersect each other.
[0036] The substrate (110) is an array substrate on which transistors are formed, and may include a plastic material or a glass material.
[0037] A substrate (110) according to one example may include an opaque or colored polyimide material. In this case, a back plate coupled to the rear surface of the substrate (110) may be further included to maintain the substrate (110) in a flat state.
[0038] A back plate according to one example may include a plastic material, for example, polyethylene terephthalate.
[0039] A substrate (110) according to one example may be a glass substrate. For example, a glass substrate (110) may be a thin glass substrate having a thickness of 100 μm or less and may have flexible characteristics.
[0040] Additionally, the substrate (110) may be divided into two or more substrates bonded together or two or more layers.
[0042] FIG. 2 is a diagram showing the cross-sectional structure of a subpixel according to one embodiment. FIG. 3 is an enlarged view of the Q1 region of FIG. 2. FIG. 4 is a schematic diagram showing the path of light emitted from the light-emitting layer.
[0043] Referring to FIGS. 2 to 4, the display device (10) may further include a transistor (TR) and a light-emitting element (LD) disposed on a substrate (110). In addition, the display device (10) may further include wirings electrically connecting the transistor (TR) and the light-emitting element (LD), and at least one insulating layer disposed between each component.
[0044] A buffer layer (120) may be disposed on the substrate (110). The buffer layer (120) can minimize the diffusion of moisture or impurities from the substrate (110). The buffer layer (120) may be made of silicon oxide (SiOx) or silicon nitride (SiNx), etc. The buffer layer (120) may be composed of a single layer or multiple layers of silicon oxide (SiOx) or silicon nitride (SiNx), but is not limited thereto.
[0045] A transistor (TR) may be placed on the buffer layer (120). The transistor (TR) may be used as a driving element for a light-emitting element (LD). The transistor (TR) may be a driving transistor, but is not limited thereto.
[0046] The transistor (TR) may be, for example, a thin film transistor (TFT), an N-channel metal oxide semiconductor (NMOS), a P-channel metal oxide semiconductor (PMOS), a complementary metal oxide semiconductor (CMOS), a field effect transistor (FET), but is not limited thereto.
[0047] In the following description, it is assumed that multiple transistors (TR) are thin-film transistors, but this is not limited thereto.
[0048] Each of the plurality of transistors (TR) includes a gate electrode (GE), an active layer (SCL), a source electrode (SE), and a drain electrode (DE).
[0049] A gate electrode (GE) and a common voltage wiring (121) are disposed on a buffer layer (120). The gate electrode (GE) and the common voltage wiring (121) may be composed of a conductive material, for example, copper (Cu), aluminum (Al), molybdenum (Mo), titanium (Ti), or an alloy thereof, but are not limited thereto.
[0050] The common voltage wiring (121) is electrically connected to a common power terminal (high potential voltage terminal) so that it can receive common power and transmit it to the second electrode (230) of the light-emitting element (LD).
[0051] A gate insulating layer (130) is disposed on a gate electrode (GE). The gate insulating layer (130) is a layer for insulating the gate electrode (GE) and the active layer (SCL) and may be made of an insulating material. For example, the gate insulating layer (130) may be composed of a single layer or multiple layers of silicon oxide (SiOx) or silicon nitride (SiNx), but is not limited thereto.
[0052] An active layer (SCL) is disposed on the gate insulating layer (130). For example, the active layer (SCL) may be made of an oxide semiconductor, amorphous silicon, or polysilicon, but is not limited thereto.
[0053] A source electrode (SE) and a drain electrode (DE) are spaced apart from each other on an active layer (SCL). The source electrode (SE) and the drain electrode (DE) may be electrically connected to the active layer (SCL). The source electrode (SE) and the drain electrode (DE) may be composed of a conductive material, for example, copper (Cu), aluminum (Al), molybdenum (Mo), titanium (Ti), or an alloy thereof, but are not limited thereto.
[0054] A first flattening layer (140) may be disposed on the transistor (TR). The first flattening layer (140) can flatten the upper surface of a substrate (110) containing a plurality of transistors (TR).
[0055] In FIG. 2, the gate electrode (GE) is shown positioned below the active layer (SCL), but is not limited thereto. In other words, in FIG. 2, the active layer (SCL) is shown positioned between the source electrode (SE), the drain electrode (DE), and the gate electrode (GE), but is not limited thereto.
[0056] For example, the gate electrode (GE) may be placed on top of the active layer (SCL). In this case, the gate electrode (GE) may be placed between the source electrode (SE) and the drain electrode (DE) and the active layer (SCL).
[0057] The first flattening layer (140) may be composed of a single layer or multiple layers and may be made of an organic material. For example, the first flattening layer (140) may be made of an acrylic organic material, but is not limited thereto. The first flattening layer (140) includes a contact hole for electrically connecting a transistor (TR) and a first connecting electrode (151).
[0058] Although not shown, a protective layer capable of protecting the lower components may be further disposed between the first flattening layer (140) and the transistor (TR).
[0059] A first connecting electrode (151) and a second connecting electrode (155) may be disposed on the first flattening layer (140).
[0060] The first connecting electrode (151) and the second connecting electrode (155) are disposed on the same layer and may be formed of the same material. The first connecting electrode (151) and the second connecting electrode (155) are disposed on the first flattening layer (140) and may be made of a metallic material. For example, the first connecting electrode (151) and the second connecting electrode (155) may include a light-reflecting conductive material, and the light-reflecting conductive material may include at least one selected from aluminum (Al), silver (Ag), gold (Au), platinum (Pt), or copper (Cu).
[0061] The first connecting electrode (151) can be electrically connected to the common voltage wiring (121) through a contact hole penetrating the first flattening layer (140) and the gate insulating layer (130) in the thickness direction (third direction (DR3)).
[0062] The second connecting electrode (155) can be electrically connected to the drain electrode (DE) of the transistor (TR) through a contact hole that penetrates the first flattening layer (140) in the thickness direction (third direction (DR3)).
[0063] A second flattening layer (160) may be disposed on the first connecting electrode (151) and the second connecting electrode (155). The second flattening layer (160) may be made of an organic material. For example, the second flattening layer (160) may be made of an acrylic-based organic material, but is not limited thereto. The second flattening layer (160) may be made of the same material as the first flattening layer (140), but is not limited thereto.
[0064] A first reflective electrode (RM1) may be disposed on the second flattening layer (160). The first reflective electrode (RM1) can reflect light emitted from the light-emitting element (LD) upward, and accordingly, the light extraction efficiency of the light-emitting element (LD) can be improved.
[0065] A plurality of first reflective electrodes (RM1) may be provided and disposed for each light-emitting element (LD). Each of the plurality of first reflective electrodes (RM1) may be formed in an island shape, but is not limited thereto.
[0066] The planar size (area) of the first reflective electrode (RM1) may be larger than that of the light-emitting element (LD). The entire area of the light-emitting element (LD) may overlap with the first reflective electrode (RM1) in the thickness direction (third direction (DR3)).
[0067] The first reflective electrode (RM1) may include a material with high reflectivity. For example, the first reflective electrode (RM1) may include at least one selected from aluminum (Al), silver (Ag), gold (Au), platinum (Pt), palladium (Pd), titanium (Ti), nickel (Ni), chromium (Cr), molybdenum (Mo), and tungsten (W), but is not limited thereto.
[0068] An adhesive layer (180) may be disposed on the first reflective electrode (RM1). The adhesive layer (180) may fix a light-emitting element (LD) disposed on the adhesive layer (180). The adhesive layer (180) may be made of an organic insulating layer. The adhesive layer (180) may be made of a photocurable adhesive material that can be cured by light. For example, the adhesive layer (180) may be made of an acrylic-based material containing a photosensitive agent, but is not limited thereto.
[0069] The adhesive layer (180) may include a first adhesive layer (181) and a second adhesive layer (182) that are separated and spaced apart from each other. The first adhesive layer (181) and the second adhesive layer (182) may be made of the same material and may be formed by the same process.
[0070] The first adhesive layer (181) may be disposed on the first reflective electrode (RM1). The first adhesive layer (181) may be disposed on the upper surface of the first reflective electrode (RM1). Here, the upper surface of the first reflective electrode (RM1) may refer to the opposite side of the lower surface, which is the surface facing the second flattening layer (160). The upper surface of the first reflective electrode (RM1) may face the first electrode (210). The first adhesive layer (181) may be in direct contact with the upper surface of the first reflective electrode (RM1).
[0071] The planar size (area) of the first adhesive layer (181) may be smaller than the planar size of the first reflective electrode (RM1). The entire area of the first adhesive layer (181) may overlap with the first reflective electrode (RM1) in the thickness direction (third direction (DR3)).
[0072] The first adhesive layer (181) may be separated from the second adhesive layer (182) and formed in an island shape. The first adhesive layer (181) may be provided in multiple numbers and may be placed for each first reflective electrode (MR1). The first adhesive layer (181) may be placed for each light-emitting element (LD).
[0073] The side of the first adhesive layer (181) may be aligned with the side of the first electrode (210), but is not limited thereto.
[0074] The second adhesive layer (182) may be disposed on the side of the first reflective electrode (RM1) and on the second flattening layer (160) that is not covered by the first reflective electrode (RM1). The second adhesive layer (182) may be in direct contact with the side of the first reflective electrode (RM1).
[0075] The height of the upper surface of the second adhesive layer (182) and the height of the upper surface of the first reflective electrode (RM1) may be the same, but are not limited thereto.
[0076] The first adhesive layer (181) and the second adhesive layer (182) are spaced apart from each other, and the first reflective electrode (RM1) may be exposed between the first adhesive layer (181) and the second adhesive layer (182).
[0077] A light-emitting element (LD) may be disposed on the adhesive layer (180). A light-emitting element (LD) may be disposed on the first adhesive layer (181). The light-emitting element (LD) may be disposed on the upper surface of the first adhesive layer (181). The light-emitting element (LD) may be in direct contact with the upper surface of the first adhesive layer (181).
[0078] The light-emitting diode (LD) may be a light-emitting diode (LED) or a micro-LED, but is not limited thereto. The light-emitting diode (LD) may have a vertical structure, but is not limited thereto.
[0079] A light-emitting element (LD) may include a first electrode (210), a light-emitting layer (220), a second electrode (230), and a passivation film (240). The light-emitting layer (220) may include a first semiconductor layer (221), an active layer (222), and a second semiconductor layer (223). If the light-emitting element (LD) has a vertical structure, the first electrode (210), the first semiconductor layer (221), the active layer (222), the second semiconductor layer (223), and the second electrode (230) may overlap in the thickness direction (third direction (DR3)).
[0080] The first electrode (210), the light-emitting layer (220), and the second electrode (230) may be arranged sequentially along the thickness direction (third direction (DR3)). The first electrode (210), the light-emitting layer (220), and the second electrode (230) may be overlapped along the thickness direction (third direction (DR3)). The light-emitting layer (220) may be placed between the first electrode (210) and the second electrode (230).
[0081] The first electrode (210) may be disposed between the adhesive layer (180) and the light-emitting layer (220). The first electrode (210) may be either an anode electrode or a cathode electrode. For example, the first electrode (210) may be an anode electrode, but is not limited thereto.
[0082] If the first electrode (210) is an anode electrode, the first electrode (210) can be electrically connected to a transistor (TR). If the first electrode (210) is an anode electrode, the transistor (TR) and the first semiconductor layer (221) can be electrically connected through the first electrode (210).
[0083] The first electrode (210) may include a conductive material. The conductive material may be a transparent conductive material such as, for example, ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide). However, it is not limited thereto, and the conductive material may be composed of at least one selected from opaque conductive materials such as nickel (Ni), gold (Au), platinum (Pt), titanium (Ti), aluminum (Al), chromium (Cr), copper (Cu), silver (Ag), or alloys thereof.
[0084] A light-emitting layer (220) may be disposed on the first electrode (210). The first semiconductor layer (221), the active layer (222), and the second semiconductor layer (223) of the light-emitting layer (220) may be disposed sequentially along the thickness direction. The active layer (222) may be disposed between the first semiconductor layer (221) and the second semiconductor layer (223).
[0085] A first semiconductor layer (221) may be disposed on the first electrode (210). The first semiconductor layer (221) may be disposed between the first electrode (210) and the active layer (222). The first semiconductor layer (221) may include a first type dopant. For example, the first semiconductor layer (221) may include a p-type dopant, but is not limited thereto.
[0086] When the first semiconductor layer (221) includes a p-type dopant, the first semiconductor layer (221) is a layer for supplying holes to the active layer (222), and may be doped with impurities such as magnesium (Mg), zinc (Zn), and beryllium (Be) in a material such as gallium nitride (GaN), indium aluminum phosphide (InAlP), and gallium arsenide (GaAs).
[0087] An active layer (222) may be disposed on the first semiconductor layer (221). The active layer (222) may emit light by receiving holes and electrons from the first semiconductor layer (221) and the second semiconductor layer (223). The active layer (222) may be formed as a single layer or a multi-quantum well (MQW) structure, and may be made of, for example, indium gallium nitride (InGaN) or gallium nitride (GaN), but is not limited thereto.
[0088] A second semiconductor layer (223) may be disposed on the active layer (222). The second semiconductor layer (223) may be disposed between the active layer (222) and the second electrode (230). The second semiconductor layer (223) may include a second type dopant different from the first type dopant. For example, the second semiconductor layer (223) may include an n-type dopant, but is not limited thereto.
[0089] When the second semiconductor layer (223) includes an n-type dopant, the second semiconductor layer (223) is a layer for supplying electrons to the active layer (222), and may be doped with impurities such as silicon (Si), germanium (Ge), selenium (Se), tellurium (Te), etc., in a material such as gallium nitride (GaN), indium aluminum phosphide (InAlP), gallium arsenide (GaAs), etc.
[0090] In the present specification, the first semiconductor layer (221) is described as including a p-type dopant and the second semiconductor layer (223) is described as including an n-type dopant, but is not limited thereto, and the first semiconductor layer (221) may include an n-type dopant and the second semiconductor layer (223) may include a p-type dopant.
[0091] The light-emitting layer (220) may have a mesa structure. The side of the light-emitting layer (220) may be formed as an inclined surface inclined with respect to the thickness direction (third direction (DR3)). The planar size of the light-emitting layer (220) may decrease as it extends from the first semiconductor layer (221) to the second semiconductor layer (223). The width of the light-emitting layer (220) may decrease as it extends from the first semiconductor layer (221) to the second semiconductor layer (223).
[0092] A second electrode (230) may be disposed on the second semiconductor layer (223). The second electrode (230) may be either an anode electrode or a cathode electrode. For example, if the first electrode (210) is an anode electrode, the second electrode (230) may be a cathode electrode.
[0093] In this specification, the first electrode (210) is described as an anode electrode and the second electrode (230) is a cathode electrode, but is not limited thereto. For example, the first electrode (210) may be a cathode electrode and the second electrode (230) may be an anode electrode.
[0094] If the second electrode (230) is a cathode electrode, the second electrode (230) can be electrically connected to the common voltage wiring (121). If the second electrode (230) is a cathode electrode, the second semiconductor layer (223) can be electrically connected to the common voltage terminal (or high potential voltage terminal) through the second electrode (230) and the common voltage wiring (121).
[0095] The second electrode (230) may include a conductive material. The conductive material may be composed of at least one selected from transparent conductive materials such as ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide), for example, or opaque conductive materials such as nickel (Ni), gold (Au), platinum (Pt), titanium (Ti), aluminum (Al), chromium (Cr), copper (Cu), silver (Ag), or alloys thereof, but is not limited thereto.
[0096] A passivation film (240) may be disposed on the side of the light-emitting layer (220). The passivation film (240) may be disposed along the perimeter of the light-emitting layer (220) and may be disposed to surround the light-emitting layer (220).
[0097] The passivation film (240) may be in direct contact with the side of the light-emitting layer (220). The passivation film (240) may be disposed on the side of the first semiconductor layer (221), the active layer (222), and the second semiconductor layer (223). The passivation film (240) may be in direct contact with the side of the first semiconductor layer (221), the active layer (222), and the second semiconductor layer (223).
[0098] The passivation film (240) extends from the side of the light-emitting layer (220) to cover the side of the second electrode (230) and may cover a portion of the upper surface of the second electrode (230). The passivation film (240) may expose a portion of the upper surface of the second electrode (230). The passivation film (240) may expose at least a portion of the side of the first electrode (210).
[0099] The passivation film (240) may be made of an inorganic insulating material such as, for example, silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, but is not limited thereto.
[0100] The passivation film (240) protects the light-emitting layer (220) and can prevent leakage current flowing on the side of the light-emitting layer (220).
[0101] A second reflective electrode (RM2) may be disposed on the first reflective electrode (RM1). The second reflective electrode (RM2) may be disposed on the first reflective electrode (RM1) exposed between the first adhesive layer (181) and the second adhesive layer (182). The second reflective electrode (RM2) may be disposed on the upper surface of the first reflective electrode (RM1).
[0102] The second reflective electrode (RM2) can be in direct contact with the first reflective electrode (RM1). The second reflective electrode (RM2) can be in direct contact with the upper surface of the first reflective electrode (RM1). The second reflective electrode (RM2) can be in direct contact with the first reflective electrode (RM1) exposed between the first adhesive layer (181) and the second adhesive layer (182).
[0103] The second reflective electrode (RM2) may be placed on the side of the first adhesive layer (181). The second reflective electrode (RM2) may be in direct contact with the side of the first adhesive layer (181). The second reflective electrode (RM2) may be placed to surround the first adhesive layer (181).
[0104] The second reflective electrode (RM2) may be extended in the thickness direction (third direction (DR3)) and positioned on the side of the first electrode (210). The second reflective electrode (RM2) may be in direct contact with the side of the first electrode (210). The second reflective electrode (RM2) may be positioned to surround the first electrode (210). Accordingly, the second reflective electrode (RM2) and the first electrode (210) may be in smooth contact and electrically connected.
[0105] The second reflective electrode (RM2) may be further extended in the thickness direction (third direction (DR3)) and placed on a portion of the side of the passivation film (240). The second reflective electrode (RM2) may be in direct contact with a portion of the side of the first electrode (210). The second reflective electrode (RM2) may be placed to surround a portion of the side of the passivation film (240).
[0106] The second reflective electrode (RM2) may be placed across the first adhesive layer (181) and the second adhesive layer (182), but is not limited thereto.
[0107] The second reflective electrode (RM2) may include a material with high reflectivity. The second reflective electrode (RM2) may include the same material as the first reflective electrode (RM1), but is not limited thereto.
[0108] As the second reflective electrode (RM2) is placed on the first reflective electrode (RM1) and the second reflective electrode (RM2) comes into direct contact with the first reflective electrode (RM1), the light extraction efficiency of the light emitted from the light-emitting element (LD) can be improved.
[0109] As shown in FIG. 4, as reflective electrodes (RM1, RM2) are arranged around a light-emitting element (LD), light (L) emitted from the light-emitting layer (220) and directed downward can be reflected by at least one of the first reflective electrode (RM1) and the second reflective electrode (RM2) and directed upward. Here, the downward direction may refer to the direction from the light-emitting layer (220) toward the first reflective electrode (RM1), and the upward direction may refer to the direction from the light-emitting layer (220) toward the second electrode (230).
[0110] As the first reflective electrode (RM1) and the second reflective electrode (RM2) are arranged to be in direct contact, light (L) emitted from the light-emitting layer (220) and directed downward cannot escape between the first reflective electrode (RM1) and the second reflective electrode (RM2), and can be reflected by at least one of the first reflective electrode (RM1) and the second reflective electrode (RM2) and directed upward.
[0111] That is, as the first reflective electrode (RM1) and the second reflective electrode (RM2) are arranged to be in direct contact, light (L) emitted from the light-emitting layer (220) and directed downward is reflected and does not go upward, but leaks out to the outside of the reflective electrodes (RM1, RM2), thereby minimizing the leakage. Furthermore, the light extraction efficiency of the light emitted from the light-emitting element (LD) can be improved, and low power consumption of the display device (10) can be realized, so that energy consumption can be reduced.
[0112] In addition, since the planar size of the first reflective electrode (RM1) is formed to be larger than that of the light-emitting element (LD), the light-emitting element (LD) and the second reflective electrode (RM2) can be smoothly positioned on the first reflective electrode (RM1) even if a process margin error occurs. Accordingly, even if a process margin error occurs, the second reflective electrode (RM2) can smoothly contact the first electrode (210) and the first reflective electrode (RM1). In other words, the electrical connection of the light-emitting element (LD) and the wiring (reflective electrode, connecting electrode, etc.) that contacts the light-emitting element (LD) can be smooth, and the stability of the contact process can be improved.
[0113] A pixel connection electrode (195) may be disposed on the adhesive layer (180). The pixel connection electrode (195) may be made of the same material as the common connection electrode (250), but is not limited thereto.
[0114] The pixel connection electrode (195) may be made of a transparent conductive material when the display device (10) is a front-emitting type, and may be made of a light-reflecting conductive material when the display device (10) is a back-emitting type. The transparent conductive material may be ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide), but is not limited thereto. The light-reflecting conductive material may be Al, Ag, Au, Pt, or Cu, but is not limited thereto. The pixel connection electrode (195) made of a light-reflecting conductive material may be made of a single layer containing the light-reflecting conductive material or a multilayer in which single layers are stacked.
[0115] The second flattening layer (160) can define a first through hole (TH1) that penetrates in the thickness direction (third direction (DR3)) and exposes the second connecting electrode (155).
[0116] The pixel connecting electrode (195) can be electrically connected to the first electrode (210) by contacting the second reflective electrode (RM1). Through the first through hole (TH1), the pixel connecting electrode (195) can be electrically connected by contacting the second connecting electrode (155) exposed by the first through hole (TH1). In other words, the first electrode (210) and the second connecting electrode (155) can be electrically connected by the pixel connecting electrode (195) and the second reflective electrode (RM2).
[0117] An upper insulating layer (200) may be disposed on the pixel connection electrode (195). The upper insulating layer (200) may be disposed on the adhesive layer (180) while covering the light-emitting element (LD) and the pixel connection electrode (195). The upper insulating layer (200) may be formed to have a thickness sufficient to cover the side and top surfaces of the light-emitting element (LD).
[0118] In this specification, the upper insulating layer (200) is described as being composed of a single layer, but is not limited thereto. For example, the upper insulating layer (200) may be composed of two or more layers.
[0119] The upper insulating layer (200) provides a flat surface on the transistor (TR) and the light-emitting element (LD) and can fix the position of the light-emitting element (LD).
[0120] A common connection electrode (250) may be disposed on the upper insulating layer (200). The upper insulating layer (200), the adhesive layer (180), and the second flattening layer (160) may define a second through hole (TH2) that penetrates in the thickness direction (third direction (DR3)) to expose the first connection electrode (151).
[0121] In FIG. 2, the inner wall of the second through hole (TH2) is formed by the sides of the upper insulating layer (200), the adhesive layer (180), and the second flattening layer (160), respectively, and the sides of the upper insulating layer (200), the adhesive layer (180), and the second flattening layer (160) respectively can be aligned.
[0122] However, this is not limited thereto, and the sides of the upper insulating layer (200), adhesive layer (180), and second flattening layer (160) forming the inner wall of the second through hole (TH2) may not be aligned. In other words, the upper insulating layer (200), adhesive layer (180), and second flattening layer (160) in the second through hole (TH2) may have a step difference.
[0123] Through the second through hole (TH2), the common connecting electrode (250) can be electrically connected to the first connecting electrode (151) exposed by the second through hole (TH2) by contacting the first connecting electrode (151).
[0124] The upper insulating layer (200) can penetrate in the thickness direction (third direction (DR3)) to define a third through-hole (TH3) that exposes a light-emitting element (LD). The third through-hole (TH3) can expose a second electrode (230).
[0125] Through the third through hole (TH3), the common connecting electrode (250) can come into contact with the second electrode (230) and be electrically connected to the second electrode (230).
[0126] The second electrode (230) and the first electrode (151) can be electrically connected by a common connecting electrode (250).
[0127] The common connecting electrode (250) may be made of a transparent conductive material when the display device (10) is a front-emitting type, and may be made of a light-reflecting conductive material when the display device (10) is a back-emitting type. The transparent conductive material may be ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide), but is not limited thereto. The light-reflecting conductive material may be Al, Ag, Au, Pt, or Cu, but is not limited thereto. The common connecting electrode (250) made of a light-reflecting conductive material may be made of a single layer containing the light-reflecting conductive material or a multilayer in which single layers are stacked.
[0128] Although not illustrated, after the patterning of the pixel connection electrode (250) is performed, a black matrix may be further disposed on the second through hole (TH2), the second insulating layer (200), and the pixel connection electrode (250). The black matrix may be disposed over the entire area of the display area (DA, see FIG. 1), excluding the light-emitting area of each pixel (PX, see FIG. 1).
[0129] On the black matrix, an upper protective layer and cover glass, which can flatten the upper part and protect the lower components, may be further disposed.
[0130] Light-emitting elements (LDs) may be arranged in multiple numbers for each subpixel (SP1, SP2, SP3, see FIG. 1). For example, two light-emitting elements (LDs) may be transferred for each subpixel (SP1, SP2, SP3, see FIG. 1).
[0131] Accordingly, if either of the two light-emitting elements (LDs) placed in each subpixel (SP1, SP2, SP3, see FIG. 1) is defective, light can be emitted from the corresponding subpixel (SP1, SP2, SP3, see FIG. 1) through the remaining light-emitting element (LD). Alternatively, the two light-emitting elements (LDs) placed in the subpixel (SP1, SP2, SP3, see FIG. 1) may both operate as redundancy light-emitting elements (LEDs) that emit light.
[0133] Hereinafter, a method for manufacturing a display device (1) according to one embodiment is described. While describing the method for manufacturing a display device (1) according to one embodiment, parts already described in FIGS. 1 to 4 will be briefly explained or omitted.
[0135] FIGS. 5 to 8 are drawings showing the manufacturing process of a display device according to one embodiment in steps.
[0136] Referring to FIG. 5, a light-emitting element (LD) is transferred onto a substrate (110) on which a buffer layer (120), a transistor (TR), a gate insulating layer (130), a first planarization layer (140), a second planarization layer (160), an adhesive layer (180), connecting electrodes (151, 155), and a first reflective electrode (RM1) are disposed. The light-emitting element (LD) can be transferred onto the adhesive layer (180).
[0137] The first reflective electrode (RM1) can be patterned and placed on the second flattening layer (160).
[0138] The adhesive layer (180) can be placed over the entire area of the second flattening layer (160) while covering the first reflective electrode (RM1).
[0139] The light-emitting element (LD) can be transferred onto the adhesive layer (180) in an area that overlaps with the first reflective electrode (RM1) in the thickness direction (third direction (DR3)).
[0140] After the light-emitting element (LD) is transferred, the normality of the light-emitting element (LD) can be determined by performing a lighting test.
[0141] Next, referring to FIG. 6, the adhesive layer (180) placed over the entire area of the second flattening layer (160) can be patterned to form the first adhesive layer (181) and the second adhesive layer (182) separated from each other.
[0142] In patterning the adhesive layer (180), a light-emitting element (LD) can act as a mask. Accordingly, the adhesive layer (180) remains unremoved in the area overlapping with the adhesive layer (180) in the thickness direction (third direction (DR)), thereby forming the first adhesive layer (181).
[0143] After patterning the adhesive layer (180), further ashing and descum may be performed, but are not limited thereto.
[0144] On the outside of the light-emitting element (LD), as the adhesive layer (180) is removed, a portion of the first reflective electrode (RM1) may be exposed.
[0145] A second adhesive layer (182) may be formed on the outer side of the first reflective electrode (RM1). Patterning of the adhesive layer (180) may proceed until a portion of the first reflective electrode (RM1) that does not overlap with the light-emitting element (LD) is exposed. Accordingly, the upper surface of the second adhesive layer (182) and the upper surface of the first reflective electrode (RM1) may have the same height.
[0146] Next, referring to FIG. 7, a second reflective electrode (RM2) is patterned so as to be placed on a first reflective electrode (RM1) exposed between a first adhesive layer (181) and a second adhesive layer (182). The second reflective electrode (RM2) may be deposited and then patterned to cover both the first reflective electrode (RM1) and the second adhesive layer (182), but is not limited thereto.
[0147] The patterned second reflective electrode (RM2) is positioned to surround the first adhesive layer (181) and may be in contact with the first electrode (210). The second reflective electrode (RM2) may be in contact with the side of the first electrode (210), but is not limited thereto.
[0148] Next, referring to FIG. 8, a pixel connection electrode (195), an upper insulating layer (200), and a common connection electrode (250) are formed sequentially.
[0149] First, the second flattening layer (160) is patterned to form a first through hole (TH1) that exposes the second connecting electrode (155).
[0150] Next, a pixel connection electrode (195) is patterned and formed on the second flattening layer (160). One end of the pixel connection electrode (195) contacts the second reflection electrode (RM2), and the other end is positioned within the first through hole (TH1) to contact the second connection electrode (155).
[0151] Next, an upper insulating layer (200) is formed on the pixel connecting electrode (195) and the light-emitting element (LD). The upper insulating layer (200) covers the pixel connecting electrode (195) and the light-emitting element (LD) and may be disposed over the entire second flattening layer (160), but is not limited thereto.
[0152] Next, the upper insulating layer (200), the adhesive layer (180), and the second flattening layer (160) penetrate in the thickness direction (third direction (DR3)) to form a second through hole (TH2) that exposes the first connecting electrode (151), and the upper insulating layer (200) penetrates in the thickness direction (third direction (DR3)) to form a third through hole (TH3) that exposes the light-emitting element (LD).
[0153] Next, a common connecting electrode (250) is patterned and formed on the upper insulating layer (200). One end of the common connecting electrode (250) is placed in the second through hole (TH2) to contact the first connecting electrode (151), and the other end of the common connecting electrode (250) is placed in the third through hole (TH3) to contact the second electrode (230).
[0154] In this way, by performing the step of transferring the light-emitting element (LD) and the step of forming the conductive layer (pixel connecting electrode (195), etc.) separately, the stability of each process can be improved, and the stability of the process in which the light-emitting element (LD) and the conductive layer (pixel connecting electrode (195), etc.) come into contact can also be improved. Accordingly, process efficiency can be improved and process costs can be reduced, and furthermore, production energy can be reduced.
[0156] Hereinafter, other embodiments of the present specification will be described. Among the configurations included in the other embodiments, those that are substantially identical to those described with reference to FIGS. 1 to 8 are given the same reference numerals, and duplicate content may be omitted or simplified.
[0158] FIG. 9 is a cross-sectional view of a display device according to another embodiment.
[0159] Referring to FIG. 9, in the display device (10_1) according to the present embodiment, the pixel connecting electrode (195, see FIG. 2) may be omitted.
[0160] The display device (10_1) may include a first reflective electrode (RM1_1). The first reflective electrode (RM1_1) may be placed for each light-emitting element (LD).
[0161] One end of the first reflective electrode (RM1_1) is positioned below the light-emitting element (LD) to contact the second reflective electrode (RM2), and the other end is positioned inside the first through hole (TH1) defined by the second flattening layer (160) to contact the second connecting electrode (155). The second reflective electrode (RM2) can contact the first electrode (210).
[0162] Accordingly, the first electrode (210) and the second connecting electrode (155) can be electrically connected through the first reflective electrode (RM1_1) and the second reflective electrode (RM2).
[0163] In this case as well, as the first reflective electrode (RM1_1) and the second reflective electrode (RM2) come into direct contact, the light emitted from the light-emitting element (LD) can be reflected more smoothly toward the top, and furthermore, the light extraction efficiency of the light-emitting element (LD) can be improved.
[0165] FIG. 10 is a cross-sectional view of a display device according to another embodiment. FIG. 10 is an enlarged view of the area around a light-emitting element (LD).
[0166] Referring to FIG. 10, the display device (10_2) according to the present embodiment includes a first reflective electrode (RM1_2), wherein at least a portion of the surface of the first reflective electrode (RM1_2) may be formed with an uneven structure.
[0167] A portion of the upper surface of the first reflective electrode (RM1_2) may be formed with an uneven structure. The upper surface of the first reflective electrode (RM1_2) may refer to the surface facing the first adhesive layer (181). The area of the upper surface of the first reflective electrode (RM1_2) that overlaps with the first adhesive layer (181) in the thickness direction (third direction (DR3)) may be formed with an uneven structure.
[0168] In this case as well, as the first reflective electrode (RM1_2) and the second reflective electrode (RM2) come into direct contact, the light emitted from the light-emitting element (LD) can be reflected more smoothly toward the top, and furthermore, the light extraction efficiency of the light-emitting element (LD) can be improved.
[0169] In addition, as the upper surface of the first reflective electrode (RM1_2) is formed with an uneven structure, light emitted from the light-emitting element (LD) can be reflected more smoothly toward the upper side, and the light extraction efficiency of the light-emitting element (LD) can be further improved.
[0171] FIG. 11 is a cross-sectional view of a display device according to another embodiment. FIG. 11 is an enlarged view of the area around a light-emitting element (LD).
[0172] Referring to FIG. 11, in the display device (10_3) according to the present embodiment, the first adhesive layer (181) may expose a portion of the lower surface of the first electrode (210). Here, the lower surface of the first electrode (210) refers to the surface facing the first adhesive layer (181). The second reflective electrode (RM2) may come into contact with the side and lower surface of the first electrode (210).
[0173] A portion of the lower surface of the first electrode (210) exposed by the first adhesive layer (181) may be located near the edge of the lower surface of the first electrode (210). The side of the first electrode (210) may protrude outwardly more than the side of the first adhesive layer (181).
[0174] As shown in FIG. 6, in the process of patterning the adhesive layer (180), the patterning process may proceed as an isotropic etching. In this case, the side of the first adhesive layer (181) may be etched and positioned further inward than the side of the first electrode (210).
[0175] Subsequently, a second reflective electrode (RM2) can be formed. The second reflective electrode (RM2) may have high step coverage, and the second reflective electrode (RM2) may be placed not only on the side of the first electrode (210) but also on the lower surface of the first electrode (210) exposed by the first adhesive layer (181). The second reflective electrode (RM2) may come into direct contact with the side and lower surface of the first electrode (210).
[0176] In this case as well, as the first reflective electrode (RM1) and the second reflective electrode (RM2) come into direct contact, the light emitted from the light-emitting element (LD) can be reflected more smoothly toward the top, and furthermore, the light extraction efficiency of the light-emitting element (LD) can be improved.
[0177] In addition, as the second reflective electrode (RM2) comes into contact with the side and bottom surfaces of the first electrode (210), the contact area is widened, allowing the contact between the second reflective electrode (RM2) and the first electrode (210) to be made more stably.
[0179] FIG. 12 is a cross-sectional view of a display device according to another embodiment. FIG. 12 is an enlarged view of the area around a light-emitting element (LD).
[0180] Referring to FIG. 12, the display device (10_4) according to the present embodiment includes a passivation film (240_4), and differs from the embodiment of FIG. 11 in that the passivation film (240_4) covers up to the side of the first electrode (210).
[0181] The passivation film (240_4) covers the second electrode (230) and the light-emitting layer (220), and can be further extended to cover the side of the first electrode (210). The passivation film (240_4) can cover the entire side area of the first electrode (210), but is not limited thereto. The passivation film (240_4) can come into direct contact with the side of the first electrode (210).
[0182] A passivation film (240_4) may be placed between the second reflection electrode (RM2) and the first electrode (210).
[0183] The second reflective electrode (RM2) and the first electrode (210) can be electrically connected by making contact with each other through the lower surface of the first electrode (210) exposed by the first adhesive layer (181).
[0184] In this case as well, as the first reflective electrode (RM1) and the second reflective electrode (RM2) come into direct contact, the light emitted from the light-emitting element (LD) can be reflected more smoothly toward the top, and furthermore, the light extraction efficiency of the light-emitting element (LD) can be improved.
[0185] In addition, as the passivation film (240_4) covers the sides of the first electrode (210), the light-emitting layer (220), and the second electrode (230), leakage current can be prevented more smoothly, and unnecessary short circuits with surrounding conductive layers can be suppressed or prevented.
[0187] FIG. 13 is a cross-sectional view of a display device according to another embodiment. FIG. 14 is an enlarged view of the Q2 area of FIG. 13.
[0188] Referring to FIGS. 13 and 14, the display device (10_5) according to the present embodiment includes a light-emitting element (LD_5), and the light-emitting element (LD_5) may have a flip-type structure. The light-emitting element (LD_5) may be made of a flip-chip.
[0189] The first reflective electrode (RM1_5) may include a first reflective electrode (RM11) and a second reflective electrode (RM12) that are separated from each other. The first reflective electrode (RM11) and the second reflective electrode (RM12) may be electrically insulated from each other.
[0190] The second reflective electrode (RM2_5) may include a 21st reflective electrode (RM21) and a 22nd reflective electrode (RM22) separated from each other. The 21st reflective electrode (RM21) and the 22nd reflective electrode (RM22) may be electrically insulated from each other.
[0191] The 21st reflective electrode (RM21) is placed on the 11th reflective electrode (RM11) so as to be in direct contact with the 11th reflective electrode (RM11). The 22nd reflective electrode (RM22) is placed on the 12th reflective electrode (RM12) so as to be in direct contact with the 12th reflective electrode (RM12).
[0192] The light-emitting element (LD_5) may include a first electrode (210_5), a light-emitting layer (220), a semiconductor insulating layer (225), and a passivation film (240).
[0193] The first electrode (210_5) may include a first electrode (211) and a second electrode (212) that are separated from each other. The first electrode (211) and the second electrode (212) may be electrically insulated from each other.
[0194] The 11th electrode (211) and the 12th electrode (212) may be placed on the same layer. The 11th electrode (211) and the 12th electrode (212) may be placed on the 1st adhesive layer (181).
[0195] The 11th electrode (211) is electrically connected by contacting the 21st reflective electrode (RM21), and the 12th electrode (212) can be electrically connected by contacting the 22nd reflective electrode (RM22).
[0196] The 11th electrode (211) can be electrically connected by contacting the 1st semiconductor layer (221). The 12th electrode (212) can be electrically connected by contacting the 2nd semiconductor layer (223). The 11th electrode (211) may be an anode electrode and the 12th electrode (212) may be a cathode electrode, but is not limited thereto.
[0197] Accordingly, the second electrode (230) of FIG. 2 in the light-emitting element (LD_5) may be omitted, and the role of the second electrode (230) of FIG. 2 may be performed by the 12th electrode (212).
[0198] A light-emitting layer (220) may be disposed on the 11th electrode (211) and the 12th electrode (212). The 12th electrode (212) may include a protrusion that protrudes toward the second semiconductor layer (223). Specifically, the 12th electrode (212) may be disposed between the light-emitting layer (220) and the first adhesive layer (181) and may include a protrusion that protrudes toward the second semiconductor layer (223). Through this, the 12th electrode (212) may be electrically connected by contacting the second semiconductor layer (223).
[0199] A semiconductor insulating layer (225) may be disposed between the 12th electrode (212) and the 1st semiconductor layer (221), and between the 12th electrode (212) and the active layer (222). The semiconductor insulating layer (225) may include an inorganic insulating material, but is not limited thereto.
[0200] Through the semiconductor insulating layer (225), short circuits between the 12th electrode (212) and the 1st semiconductor layer (221), and short circuits between the 12th electrode (212) and the active layer (222) can be prevented.
[0201] The pixel connection electrode (195) is electrically connected by contacting the 21st reflection electrode (RM21), and the common connection electrode (250) can be electrically connected by contacting the 22nd reflection electrode (RM22).
[0202] The common connecting electrode (250) can contact the first connecting electrode (151) through a second through hole (TH2_5) defined by the second flattening layer (160) and the second adhesive layer (182).
[0203] The common connection electrode (250) may be placed on the same layer as the pixel connection electrode (195), but is not limited thereto.
[0204] An upper insulating layer (200) may be disposed on the pixel connection electrode (195), the common connection electrode (250), and the light-emitting element (LD_5).
[0205] In this case as well, as the first reflective electrode (RM1_5) and the second reflective electrode (RM2_5) come into direct contact, the light emitted from the light-emitting element (LD_5) can be reflected more smoothly toward the top, and furthermore, the light extraction efficiency of the light-emitting element (LD_5) can be improved.
[0207] FIG. 15 is a cross-sectional view of a display device according to another embodiment. FIG. 15 is an enlarged view of the area around a light-emitting element (LD).
[0208] Referring to FIG. 15, the display device (10_6) according to the present embodiment may include a first reflective electrode (RM1_6) having different thicknesses for each region.
[0209] The first reflective electrode (RM1_6) may include a first region (AA1) and a second region (AA2) having different thicknesses. The thickness of the first region (AA1) may be thicker than the thickness of the second region (AA2). Here, the thickness of the first region (AA1) and the thickness of the second region (AA2) may refer to the width in the thickness direction (third direction (DR3)).
[0210] The first region (AA1) may overlap with the first adhesive layer (181) in the thickness direction (third direction (DR3)). The second region (AA2) may not overlap with the first adhesive layer (181) in the thickness direction (third direction (DR3)).
[0211] The second region (AA2) may be placed around the first region (AA1). The second region (AA2) may be placed to surround the first region (AA1), but is not limited thereto.
[0212] As shown in FIG. 6, in the process of patterning the adhesive layer (180) to expose the first reflective electrode (RM1_6), a portion of the first reflective electrode (RM1_6) that does not overlap with the adhesive layer (180) may be etched in the thickness direction and may be formed with a thinner thickness than the remaining portion that overlaps with the adhesive layer (180).
[0213] In this case as well, as the first reflective electrode (RM1_6) and the second reflective electrode (RM2) come into direct contact, the light emitted from the light-emitting element (LD) can be reflected more smoothly upward, and furthermore, the light extraction efficiency of the light-emitting element (LD) can be improved.
[0215] A display device according to various embodiments of the present specification may be described as follows.
[0216] A display device according to the embodiments of the present specification comprises a substrate, a transistor disposed on the substrate, a planarization layer disposed on the transistor, a first reflective electrode disposed on the planarization layer, a first adhesive layer disposed on the first reflective electrode, a light-emitting element disposed on the first adhesive layer, and a second reflective electrode in contact with the light-emitting element, wherein the first reflective electrode and the second reflective electrode are in direct contact.
[0217] According to various embodiments of the present specification, a light-emitting element may be disposed on the upper surface of a first adhesive layer, and a second reflective electrode may be disposed on the side surface of the first adhesive layer.
[0218] According to various embodiments of the present specification, the light-emitting element may be in direct contact with the upper surface of the first adhesive layer, and the second reflective electrode may be in direct contact with the side surface of the first adhesive layer.
[0219] According to various embodiments of the present specification, the second reflective electrode may surround the first adhesive layer.
[0220] According to various embodiments of the present specification, a second reflective electrode may be disposed on the upper surface of a first reflective electrode.
[0221] According to various embodiments of the present specification, a second adhesive layer is further included that is separated from the first adhesive layer and disposed on the side of the second reflective electrode, and the second reflective electrode can be in direct contact with the first reflective electrode exposed between the first adhesive layer and the second adhesive layer.
[0222] According to various embodiments of the present specification, the height of the upper surface of the second adhesive layer may be the same as the height of the upper surface of the second reflective electrode.
[0223] According to various embodiments of the present specification, the first adhesive layer and the second adhesive layer may comprise the same material.
[0224] According to various embodiments of the present specification, a light-emitting element comprises a first electrode, a light-emitting layer, and a second electrode that are sequentially stacked, and the second reflective electrode may be in contact with the first electrode.
[0225] According to various embodiments of the present specification, the second reflective electrode may be in direct contact with the side of the first electrode.
[0226] According to various embodiments of the present specification, the first adhesive layer exposes a portion of the lower surface of the first electrode, and the second reflective electrode can come into direct contact with the lower surface of the first electrode exposed by the first adhesive layer.
[0227] According to various embodiments of the present specification, a pixel connecting electrode disposed on a planarization layer is further included, wherein one end of the pixel connecting electrode is in contact with a second reflective electrode and the other end is electrically connected to a transistor.
[0228] According to various embodiments of the present specification, one end of the first reflective electrode is in contact with the second reflective electrode, and the other end is disposed within a through hole defined by a flattening layer and can be electrically connected to a transistor.
[0229] According to various embodiments of the present specification, the planar size of the first adhesive layer is smaller than the planar size of the first reflective electrode, and the entire area of the first adhesive layer may overlap with the first reflective electrode in the thickness direction.
[0230] According to various embodiments of the present specification, the planar size of the light-emitting element is smaller than the planar size of the first reflective electrode, and the entire region of the light-emitting element may overlap with the first reflective electrode in the thickness direction.
[0231] According to various embodiments of the present specification, in the region overlapping with the first adhesive layer, the upper surface of the first reflective electrode may have an uneven pattern.
[0232] A display device according to the embodiments of the present specification comprises a substrate, a transistor disposed on the substrate, a planarization layer disposed on the transistor, a first reflective electrode disposed on the planarization layer, a first adhesive layer disposed on the upper surface of the first reflective electrode, a light-emitting element disposed on the first adhesive layer, and a second reflective electrode disposed on the upper surface of the first reflective electrode, wherein the second reflective electrode is disposed to surround the first adhesive layer.
[0233] According to various embodiments of the present specification, the second reflective electrode contacts the light-emitting element and can come into direct contact with the first reflective electrode.
[0234] According to various embodiments of the present specification, the second reflective electrode may be in direct contact with the side of the first adhesive layer.
[0235] According to various embodiments of the present specification, the light-emitting element may come into direct contact with the upper surface of the first adhesive layer.
[0236] Although embodiments have been described above with reference to the attached drawings, those skilled in the art to which this specification pertains will understand that the technical configurations described above may be implemented in other specific forms without altering the technical concept or essential features. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. Furthermore, the scope of the embodiments is defined by the claims set forth below rather than by the detailed description. Additionally, all modifications or variations derived from the meaning and scope of the claims and equivalent concepts should be interpreted as being included within the scope of the embodiments. Explanation of the symbols
[0237] 10: Display device 110: Substrate TR: Transistor 180: Adhesive layer 181: First adhesive layer 182: Second adhesive layer LD: Light-emitting element 210: First electrode 220: Active layer 230: Second electrode 240: Passivation membrane 200: Upper insulation layer RM1: First reflective electrode RM2: Second reflective electrode TH: Through hole
Claims
Claim 1 A display device comprising: a substrate; a transistor disposed on the substrate; a planarization layer disposed on the transistor; a first reflective electrode disposed on the planarization layer; a first adhesive layer disposed on the first reflective electrode; a light-emitting element disposed on the first adhesive layer; and a second reflective electrode in contact with the light-emitting element, wherein the first reflective electrode and the second reflective electrode are in direct contact. Claim 2 A display device according to claim 1, wherein the light-emitting element is disposed on the upper surface of the first adhesive layer and the second reflective electrode is disposed on the side surface of the first adhesive layer. Claim 3 A display device according to claim 2, wherein the light-emitting element is in direct contact with the upper surface of the first adhesive layer, and the second reflective electrode is in direct contact with the side surface of the first adhesive layer. Claim 4 In claim 3, the second reflective electrode is a display device surrounding the first adhesive layer. Claim 5 In claim 1, the second reflective electrode is a display device disposed on the upper surface of the first reflective electrode. Claim 6 A display device according to claim 5, further comprising a second adhesive layer separated from the first adhesive layer and disposed on the side of the second reflective electrode, wherein the second reflective electrode is in direct contact with the first reflective electrode exposed between the first adhesive layer and the second adhesive layer. Claim 7 In claim 6, a display device in which the height of the upper surface of the second adhesive layer is the same as the height of the upper surface of the second reflective electrode. Claim 8 In claim 7, the display device comprising the first adhesive layer and the second adhesive layer having the same material. Claim 9 In claim 1, the light-emitting element comprises a first electrode, a light-emitting layer, and a second electrode stacked sequentially, and the second reflective electrode is a display device in contact with the first electrode. Claim 10 In claim 9, the second reflective electrode is a display device that is in direct contact with the side of the first electrode. Claim 11 A display device according to claim 9, wherein the first adhesive layer exposes a portion of the lower surface of the first electrode, and the second reflective electrode is in direct contact with the lower surface of the first electrode exposed by the first adhesive layer. Claim 12 A display device according to claim 9, further comprising a pixel connecting electrode disposed on the planarization layer, wherein one end of the pixel connecting electrode is in contact with the second reflective electrode and the other end is electrically connected to the transistor. Claim 13 In claim 9, a display device wherein one end of the first reflective electrode is in contact with the second reflective electrode, and the other end is disposed within a through hole defined by the flattening layer and electrically connected to the transistor. Claim 14 A display device according to claim 1, wherein the planar size of the first adhesive layer is smaller than the planar size of the first reflective electrode, and the entire area of the first adhesive layer overlaps with the first reflective electrode in the thickness direction. Claim 15 In claim 14, the planar size of the light-emitting element is smaller than the planar size of the first reflective electrode, and the light-emitting element is a display device in which the entire area overlaps with the first reflective electrode in the thickness direction. Claim 16 A display device according to claim 1, wherein the upper surface of the first reflective electrode has an uneven pattern in the region overlapping with the first adhesive layer. Claim 17 A display device comprising: a substrate; a transistor disposed on the substrate; a planarization layer disposed on the transistor; a first reflective electrode disposed on the planarization layer; a first adhesive layer disposed on the upper surface of the first reflective electrode; a light-emitting element disposed on the first adhesive layer; and a second reflective electrode disposed on the upper surface of the first reflective electrode; wherein the second reflective electrode is disposed to surround the first adhesive layer. Claim 18 In claim 17, the second reflective electrode contacts the light-emitting element and is a display device in direct contact with the first reflective electrode. Claim 19 In claim 17, the second reflective electrode is a display device that is in direct contact with the side of the first adhesive layer. Claim 20 In claim 19, the light-emitting element is a display device that is in direct contact with the upper surface of the first adhesive layer.