Light-emitting device

Abstract

The present invention relates to a light-emitting device comprising a scattering layer, wherein the light-emitting device may comprise: a sapphire substrate; a light-emitting element layer comprising cells, each comprising one or more light-emitting element sub-cells formed on a first surface of the sapphire substrate; a power supply pad for supplying power to the sub-cells; and a scattering layer formed on a second surface, opposite to the first surface, of the sapphire substrate.

Description

light-emitting device

[0001] Various embodiments of the present disclosure relate to a light-emitting device including a scattering layer.

[0002]

[0003] In the field of displays, the viewing angle is a critical factor in image quality. While evaluation criteria may vary depending on the type of light-emitting device included in the display, the viewing angle refers to the range of angles where changes in color, brightness, contrast ratio, etc., are minimal when viewing the screen from various angles, such as the side or top and bottom.

[0004] To secure a large viewing angle, LED (light emitting diode) based display devices may apply a scattering layer doped with scattering particles such as zirconium dioxide (ZrO2) or titanium dioxide (TiO2) onto the light-emitting element. The reflectance of the display screen may increase due to the scattering layer doped with scattering particles, and while the reflectance can be reduced by additionally forming a black film on the scattering layer, this method may reduce the driving efficiency of the display device.

[0005] In the case of a structure in which a scattering layer is formed on a light-emitting element, there is an advantage in obtaining a larger viewing angle as the concentration of scattering particles within the scattering layer increases, but a trade-off relationship may arise in which the reflectivity of the display screen increases.

[0006]

[0007] Accordingly, various embodiments of the present disclosure aim to provide a light-emitting device structure that can increase the efficiency of a display device while securing a viewing angle by forming a scattering layer on a light-emitting element.

[0008] The technical tasks intended to be accomplished in this document are not limited to those mentioned above, and other technical tasks not mentioned will be clearly understood by those skilled in the art to which this post belongs from the description below.

[0009]

[0010] According to one embodiment of the present invention, a light-emitting device may include a sapphire substrate, a light-emitting element layer including a cell including one or more light-emitting element sub-cells formed on a first surface of the sapphire substrate, a power supply pad that supplies power to the sub-cells, and a scattering layer formed on a second surface opposite to the first surface of the sapphire substrate.

[0011] In addition, the scattering layer can be formed by non-uniformly etching the second surface of the sapphire substrate.

[0012] In addition, the scattering layer can be formed by low-temperature deposition of gallium nitride on the second surface of the sapphire substrate.

[0013] In addition, the scattering layer may be formed by additionally non-uniformly etching one surface of gallium nitride formed on the second surface of the sapphire substrate.

[0014] In addition, the scattering layer may include titanium dioxide particles.

[0015] In addition, the cell may include a COB (Chip on board) light-emitting element sub-cell.

[0016] In addition, a color filter corresponding to the color of light emitted by the COB light-emitting element subcell may be further provided on the scattering layer.

[0017] In addition, the scattering layer may be additionally doped with an organic pigment or an inorganic dye corresponding to the color of light emitted by the COB light-emitting element subcell.

[0018] In addition, a transparent protective layer may be further provided on the scattering layer.

[0019] In addition, a transparent protective layer may be further provided on the color filter.

[0020] According to one embodiment of the present invention, a method for manufacturing a light-emitting device may include the steps of forming a light-emitting element layer on a first surface of a sapphire substrate, connecting a power supply pad to the light-emitting element layer, polishing a second surface opposite to the first surface of the sapphire substrate to make it flat, and forming a scattering layer on the second surface.

[0021] Additionally, the step of forming the scattering layer may include the step of forming the scattering layer by non-uniformly etching a second surface of the sapphire substrate.

[0022] Additionally, the step of forming the scattering layer may include the step of forming a mask in an area excluding the area corresponding to the light-emitting element layer on the second surface of the sapphire substrate, and the step of forming the scattering layer by low-temperature depositing gallium nitride in an area on the second surface of the sapphire substrate where the mask is not formed.

[0023] Additionally, the step of forming the scattering layer may further include the step of non-uniformly etching one surface of gallium nitride formed on the second surface of the sapphire substrate.

[0024] Additionally, the step of forming the scattering layer may include the step of forming a mask in an area excluding the area corresponding to the light-emitting element layer on the second surface of the sapphire substrate, and the step of forming a scattering layer containing titanium dioxide (TiO2) particles in an area on the second surface of the sapphire substrate where the mask is not formed.

[0025] In addition, the step of forming the light-emitting element layer may include the step of forming a light-emitting element layer including a COB (Chip on board) light-emitting element sub-cell.

[0026] In addition, the above manufacturing method may further include the step of forming a color filter on the scattering layer that corresponds to the color of light emitted by the COB light-emitting element subcell.

[0027] Additionally, the step of forming the scattering layer may further include the step of additionally doping the scattering layer with an organic pigment or an inorganic dye corresponding to the color of light emitted by the COB light-emitting element subcell.

[0028] In addition, the above manufacturing method may further include the step of forming a transparent protective layer on the scattering layer.

[0029] In addition, the above manufacturing method may further include the step of forming a transparent protective layer on the color filter.

[0030] In addition, the above manufacturing method may further include the step of cutting the sapphire substrate in an area where the scattering layer is not formed.

[0031]

[0032] According to one embodiment of the present invention, a scattering layer can be easily formed on a light-emitting element, and a large viewing angle can be secured while maintaining high efficiency of the display device.

[0033] The effects obtainable from this post are not limited to those mentioned above, and other unmentioned effects will be clearly understood by a person with ordinary knowledge in the technical field to which this post belongs from the description below.

[0034]

[0035] FIG. 1 is a circuit diagram illustrating a structure in which sub-cells are arranged according to one embodiment of the present invention.

[0036] FIG. 2 is a cross-sectional view showing the structure of a light-emitting device in which sub-cells are stacked and arranged according to one embodiment of the present invention.

[0037] FIG. 3 is a cross-sectional view showing the structure of a light-emitting device in which sub-cells are arranged in one layer according to an embodiment of the present invention.

[0038] FIG. 4 is a cross-sectional view showing the structure of a light-emitting device including a COB light source according to one embodiment of the present invention.

[0039] FIG. 5 is a cross-sectional view showing the structure of a light-emitting device including a color filter corresponding to a COB light source according to one embodiment of the present invention.

[0040] FIG. 6 is a cross-sectional view showing the structure of a light-emitting device in which a scattering layer and a color filter are formed as a single layer according to one embodiment of the present invention.

[0041] Figure 7 is a cross-sectional view showing the structure of a light-emitting device including a transparent protective layer.

[0042] FIG. 8 is a cross-sectional view showing a structure of a light-emitting device having a scattering layer formed on a sapphire substrate according to one embodiment of the present invention.

[0043] FIG. 9 is a cross-sectional view of a light-emitting device showing the structure of a scattering layer according to one embodiment of the present invention.

[0044] FIGS. 10 to 14 are drawings illustrating a method for manufacturing a light-emitting device according to an embodiment of the present invention.

[0045]

[0046] The advantages and features of this post, and the methods for achieving them, will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, this post is not limited to the embodiments described below but may be implemented in various different forms; these embodiments are provided merely to ensure that the posting of this post is complete and to fully inform those skilled in the art of the scope of this post, and this post is defined only by the scope of the claims. Throughout the specification, the same reference numerals refer to the same components.

[0047] When one component is referred to as being "connected to" or "coupled to" another component, it includes cases where it is directly connected or coupled to the other component, or cases where another component is interposed. Conversely, when one component is referred to as being "directly connected to" or "directly coupled to" another component, it indicates that no other component is interposed. "And / or" includes each of the mentioned items and all combinations of one or more of them.

[0048] The terms used herein are for describing embodiments and are not intended to limit this post. In this specification, the singular form includes the plural form unless specifically stated otherwise in the text. As used herein, "comprises" and / or "comprising" do not exclude the presence or addition of one or more other components, steps, actions, and / or elements to the mentioned components, steps, actions, and / or elements.

[0049] Although terms such as "first," "second," etc., are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are used merely to distinguish one component from another.

[0050] Therefore, it is obvious that the first component mentioned below may be the second component within the technical scope of this post. Unless otherwise defined, all terms used in this specification (including technical and scientific terms) may be used in a meaning that is commonly understood by those skilled in the art to which this post belongs. Furthermore, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless explicitly and specifically defined otherwise.

[0051] Hereinafter, embodiments of the present invention are described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein.

[0052] FIG. 1 is a circuit diagram illustrating a structure in which sub-cells are arranged according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view showing the structure of a light-emitting device in which sub-cells are stacked and arranged according to an embodiment of the present invention.

[0053] A display device may output an image by repeatedly arranging light-emitting devices, each including one or more light-emitting elements, on a substrate. At this time, the smallest unit of a light-emitting element emitting the same color may be referred to as a sub-cell, and the smallest unit of an image output formed by a collection of sub-cells may be referred to as a cell (30). The smallest unit comprising the cell (30) of the present disclosure, the substrate on which the cell (30) is formed, a power supply circuit or power supply pad (40), and a scattering layer (60) may be referred to as a light-emitting device.

[0054] Referring to FIG. 1, a plurality of diodes (10) may be arranged on a substrate of a display device in rows and columns. The plurality of diodes (10) may be connected to one of a plurality of scan lines (100) in a row-by-row manner and to one of a plurality of data lines (200) in a column-by-column manner. The scan lines (100) and data lines (200) may be operated by a separate control module. When no separate signal is applied, the scan lines (100) may not be connected to the diodes forming each row as shown in FIG. 1. One of the plurality of scan lines (100) may be connected to one row of diodes (10) per frame in a frame-by-frame manner according to the clock signal of the control module when the display device is operating. Among the diodes (10) in a row to which the scan lines (100) are connected, the signal of the data line (200) may be applied to the diode (10) that requires light emission to perform the light emission operation. Each diode (10) may be an LED (light emitting diode) or a MicroLED, which is a miniaturized version of an LED, and each diode (10) may be a sub-cell constituting a cell (30) of a light-emitting device. The diode (10) may be a light-emitting diode that emits red, green, or blue light. According to one embodiment, a cell may be formed by stacking sub-cells that emit red, green, or blue light on a substrate. In other words, a plurality of diodes (10) may be stacked and arranged in the direction of the substrate. According to another embodiment, a plurality of diode (10) chips may be densely arranged on a substrate to obtain higher luminous intensity, brightness, and uniformity of light in the same area. A structure composed of diodes (10) arranged in such a dense manner may be referred to as a COB (Chip on Board) light source.

[0055] Referring to FIG. 2, a red light subcell (21), a green light subcell (22), and a blue light subcell (23) may be formed by stacking them on a sapphire substrate (50) in the direction of the sapphire substrate (50). The sapphire substrate (50) may have high durability and excellent heat dissipation characteristics. A unit formed by combining red light, green light, and blue light subcells (21, 22, 23) may be referred to as a cell (30). FIG. 2 illustrates a cell (30) with a structure in which the green light subcell (22), the blue light subcell (23), and the red light subcell (21) are stacked in that order on the sapphire substrate (50), but the stacking order is not limited to this and may vary. Additionally, FIG. 2 illustrates a structure in which a cell (30) includes one red light, one green light, and one blue light sub-cell (21, 22, 23), but the cell (30) may be provided with two or more sub-cells that emit light of the same color. Through a structure in which the sub-cells shown in FIG. 2 are stacked and arranged, a larger size sub-cell can be placed within the same area, and accordingly, the image quality of the display device can be improved.

[0056] Referring to FIG. 2, a power supply pad (40) can be connected to a sub-cell to supply power. The power supply pad (40) can be provided and connected to each sub-cell, or provided and connected to each cell (30) as shown in FIG. 2. Electrical signals from the scan line (100) and the data line (200) can be transmitted to the sub-cell through the power supply pad (40) to perform a light emission operation. When the light emission operation is performed, light emitted from the cell (30) can pass through the sapphire substrate (50) and the scattering layer (60) to display an image to the user.

[0057] Referring to FIG. 2, a scattering layer (60) may be formed on the opposite side of the one side where the cell (30) of the sapphire substrate (50) is formed. The structure of the scattering layer is described in more detail in FIG. 9.

[0058] FIG. 3 is a cross-sectional view showing the structure of a light-emitting device in which sub-cells are arranged in one layer according to an embodiment of the present invention.

[0059] Referring to FIG. 3, red light, green light, and blue light subcells (21, 22, 23) can be arranged in a single layer without being stacked to form a cell (30). Although not shown in FIG. 3, a white light subcell formed by combining diodes emitting red light, green light, and blue light can be additionally provided and arranged in the same layer, and each subcell can be arranged in a single layer with one or more subcells emitting light of the same color as described in FIG. 2. The structure of the cell (30) shown in FIG. 3 may have a reduced area for each subcell within the same area compared to the structure shown in FIG. 2, but the light emitted by each subcell does not pass through other subcells, allowing for a more vivid display of color.

[0060] FIG. 4 is a cross-sectional view showing the structure of a light-emitting device including a COB light source according to one embodiment of the present invention.

[0061] Referring to FIG. 4, a COB (chip on board) light source (70) can be used as a light-emitting element. The COB light source may be a single board configured in a form in which multiple LED chips emitting light of the same color are densely arranged on a substrate. By directly arranging each LED chip on the substrate without a packaging process and connecting it to a power supply pad (40), uniform light with a higher light intensity can be emitted compared to the method of configuring a single LED chip as a sub-cell as shown in FIG. 2 or FIG. 3. In addition, since the LED chip is directly connected to the substrate, the heat dissipation path is short, so the heat dissipation efficiency and power efficiency can be excellent. Multiple COB light sources (70) emitting different colors can be combined to form a single cell (30). When using a COB light source (70), multiple LED chips emitting light of the same color constituting the COB light source can be viewed as a single sub-cell.

[0062] FIG. 5 is a cross-sectional view showing the structure of a light-emitting device including a color filter corresponding to a COB light source according to one embodiment of the present invention.

[0063] Referring to FIG. 5, a color filter (80) corresponding to a COB light source (70) may be further formed on the scattering layer (60) in the structure shown in FIG. 4. The color filter (80) may be added to reduce the reflectance increased by the scattering layer (60).

[0064] The color filter (80) is formed from a polymer material that acts as an organic pigment or an inorganic pigment and can selectively transmit light of a specific wavelength. According to one embodiment, the color filter (80) corresponding to the COB light source (70) emitting red light has a red light transmittance of 80% or more and a green light and blue light transmittance of 50% or less, so the red light transmittance may be higher than the transmittance of other colors. The color filter (80) corresponding to the COB light source (70) emitting green light may have a green light transmittance of 80% or more and a red light and blue light transmittance of 50% or less. And the color filter (80) corresponding to the COB light source (70) emitting blue light may have a blue light transmittance of 80% or more and a red light and green light transmittance of 50% or less. As illustrated in FIG. 5, by further including a color filter (80), the light-emitting device can emit light with higher purity and uniformity. Additionally, by increasing the purity and uniformity of one COB light source (70), when light emitted from one light source is mixed with light emitted from a COB light source (70) that emits light of a different color, a color with higher clarity can be provided to the user.

[0065] FIG. 6 is a cross-sectional view showing the structure of a light-emitting device in which a scattering layer and a color filter are formed as a single layer according to one embodiment of the present invention.

[0066] Referring to FIG. 6, a scattering layer (90) with a color filter function can be formed to correspond to the color of light emitted by a COB light source (70) by including a polymer material containing organic pigments and inorganic pigments in the scattering layer (60) shown in FIG. 5 so that it can function as a color filter (80). The display device with the structure shown in FIG. 6 can be manufactured to be thinner than the display device with the structure in which the scattering layer (60) and the color filter (80) shown in FIG. 5 are made of different layers.

[0067] Figure 7 is a cross-sectional view showing the structure of a light-emitting device including a transparent protective layer.

[0068] Referring to FIG. 7, a transparent protective layer (110) for protecting the scattering layer (60) and the color filter (80) can be further formed on the scattering layer (60) and the color filter (80). As will be described later, the scattering layer (60) is formed by etching a certain pattern or one side of the scattering layer (60) non-uniformly, and through protection of this structure, the light scattering function of the scattering layer (60) can be maintained for a long period. The transparent protective layer (110) is made of resin, and polymer materials such as epoxy, acrylic, polyurethane, and silicone can be used as the resin material. According to one embodiment, the transparent protective layer (110) can be formed directly on the scattering layer (60) without providing the color filter (80).

[0069] FIG. 8 is a cross-sectional view showing a structure of a light-emitting device having a scattering layer formed on a sapphire substrate according to one embodiment of the present invention.

[0070] Referring to FIG. 8, a scattering layer (55) can be formed by non-uniformly etching one side of the sapphire substrate (50) that is not in contact with a light source. The roughness of the non-uniformly etched surface can be set between 500 nm and 5 µm. When light passes through one side of the non-uniformly etched sapphire substrate (50), refraction in various directions may occur compared to when it passes through an unetched sapphire substrate (50), which can provide a large viewing angle to the user viewing the display screen. In addition, by forming a scattering layer (55) on the sapphire substrate (50), it is possible to manufacture the display device thinner as a separate layer is not formed. In the structure shown in FIG. 8, a separate scattering material is not doped into the scattering layer (55), thereby preventing a decrease in efficiency caused by the scattering material.

[0071] FIG. 9 is a cross-sectional view of a light-emitting device showing the structure of a scattering layer according to one embodiment of the present invention.

[0072] Referring to FIG. 9, according to another embodiment, a scattering layer (60) may be applied to a sapphire substrate (50), and one surface of the scattering layer (60) may be etched unevenly. Accordingly, in addition to the scattering of the existing scattering layer (60), light may be scattered as it passes through the unevenly etched surface as described in FIG. 8, thereby providing the user with a larger viewing angle.

[0073] The scattering layer (60) may be polycrystalline gallium nitride (GaN) deposited by low-temperature growth on a sapphire substrate (50). Although simple deposition may be difficult because the lattice constants of the crystal structures of the sapphire substrate (50) and gallium nitride are different, the problem can be solved through a low-temperature growth and deposition process. An excellent viewing angle can be obtained due to the scattering effect caused by the crystal structure of the scattering layer (60) and scattering caused by the non-uniform etching structure of the surface. At this time, the roughness of the non-uniformly etched surface can be set between 500 nm and 5 µm.

[0074] According to one embodiment, in the case of the structure shown in FIG. 9, a separate scattering material may not be doped into the scattering layer (60). Then, since the scattering effect is obtained only by the non-uniform etching structure of the surface similar to FIG. 8, the reduction in efficiency caused by the doped scattering material can be prevented.

[0075] According to another embodiment, the scattering layer (60) may include titanium dioxide (TiO2). In this case, the maximum thickness of the scattering layer may be 10 µm or less, and the D50 particle size, which represents the particle size when the cumulative percentage of the titanium dioxide (TiO2) particle size reaches 50%, may be set between 50 nm and 500 nm.

[0076] A black film can be additionally formed on the light-emitting device structure illustrated in FIGS. 2 to 9 to reduce the reflectivity of the display device.

[0077] FIGS. 10 to 14 are drawings illustrating a method for manufacturing a light-emitting device according to an embodiment of the present invention.

[0078] Referring to FIG. 10, a COB light source (70) can be formed on a sapphire substrate (50), and a power supply pad (40) can be connected to the COB light source (70). The manufacturing process described later can be applied in the same way to the process of manufacturing a light-emitting device composed of sub-cells using LEDs or MicroLEDs, with only a difference in the light-emitting element. The structure in which COB light sources (70) are arranged and connected on a wafer shown in FIG. 10 can be referred to as a COW (chip on wafer).

[0079] Referring to FIG. 11, a Chemical Mechanical Polishing (CMP) process can be performed on one side of the sapphire substrate (50) opposite the side where the COB light source (70) is formed. The CMP process is a process of flattening the substrate through chemical or physical polishing, which can reduce defects between light-emitting devices and make optical performance uniform. After the CMP process, the remaining part excluding the part corresponding to the COB light source (70) can be patterned with a mask (95).

[0080] According to one embodiment, the unmasked portion can be etched non-uniformly through patterning to form the scattering layer (55) shown in FIG. 8.

[0081] According to another embodiment, gallium nitride (GaN) can be low-temperature deposited on an unmasked portion through patterning to form a scattering layer (60) as shown in FIG. 4. Additionally, a scattering layer (60) as shown in FIG. 9 can be formed through further etching.

[0082] According to another embodiment, a scattering layer (60) containing titanium dioxide (TiO2) can be formed in an unmasked portion through patterning to form the scattering layer (60) shown in FIG. 4. Additionally, a scattering layer (60) shown in FIG. 9 can be formed through further etching.

[0083] After the scattering layer (55, 60) is formed, the mask (95) is removed and a dicing process is performed to obtain each COB light source (70) chip shown in FIG. 4, FIG. 8, or FIG. 9.

[0084] Referring to FIG. 12, a photosensitive scattering layer (60) can be applied to one side of a sapphire substrate (50) after the CMP process.

[0085] According to one embodiment, a scattering layer (60) can be formed by low-temperature deposition of gallium nitride (GaN).

[0086] According to another embodiment, a scattering layer (60) containing titanium dioxide crystals may be applied. And for cutting each of the light-emitting devices, it is necessary to remove the scattering layer (60) at the cutting site as shown in FIG. 13. This is because the scattering layer (60) scatters the laser light used in the cutting process, making cutting impossible.

[0087] According to one embodiment, through exposure and development, a mask can be placed only on the portion where the scattering layer (60) is to be present, and the remaining portion can be left uncovered. Then, through etching, the scattering layer (60) on the exposed portion not covered by the mask can be removed so that the scattering layer (60) is formed only on the opposite side of the sapphire substrate (50) corresponding to the COB light source (70), as shown in FIG. 13.

[0088] In addition, a process of doping organic pigments or inorganic pigments into the scattering layer (60) can be further performed to form a scattering layer (90) that includes a color filter function.

[0089] Referring to FIG. 14, according to another embodiment, a color filter (80) can be formed on the scattering layer (60). After completing the process, a transparent protective layer (110) can be formed on the color filter (80). After completing the formation of the scattering layer (60), the scattering layer (90) including the color filter function, the color filter (80), or the transparent protective layer (110), a cutting process to separate each light-emitting device can be performed.

[0090] According to another embodiment, a transparent protective layer (110) may be formed on the scattering layer (60) after the exposure, development, and curing processes of the scattering layer (60) are completed, or after the process of unevenly etching one side of the scattering layer (60) is completed, or after the process of doping an organic pigment or an inorganic pigment into the scattering layer (60) is completed.

[0091]

[0092] Although the present disclosure has been described with reference to embodiments illustrated in the drawings, this is merely illustrative, and those skilled in the art will understand that various modifications and equivalent alternative embodiments are possible therefrom. Accordingly, the true technical scope of protection of the present disclosure should be determined by the technical spirit of the appended claims.

Claims

1. Sapphire substrate; A light-emitting element layer comprising a cell including one or more light-emitting element sub-cells formed on a first surface of the above-mentioned sapphire substrate; A power supply pad that supplies power to the above sub-cell; and A scattering layer formed on a second surface opposite to the first surface of the sapphire substrate, comprising Light-emitting device.

2. In Paragraph 1, The above scattering layer is, A second surface of the above-mentioned sapphire substrate formed by non-uniformly etching, Light-emitting device.

3. In Paragraph 1, The above scattering layer is, A structure formed by low-temperature deposition of gallium nitride on the second surface of the above-mentioned sapphire substrate, Light-emitting device.

4. In Paragraph 3, The above scattering layer is, A surface of gallium nitride formed on the second surface of the above-mentioned sapphire substrate, additionally formed by non-uniformly etching, Light-emitting device.

5. In Paragraph 1, The above scattering layer is, containing titanium dioxide particles, Light-emitting device.

6. In Paragraph 1, The above cell includes a COB (Chip on board) light-emitting element sub-cell, Light-emitting device.

7. In Paragraph 6, A color filter further provided on the scattering layer corresponding to the color of light emitted by the COB light-emitting element subcell, Light-emitting device.

8. In Paragraph 6, The scattering layer is additionally doped with an organic pigment or an inorganic dye corresponding to the color of light emitted by the COB light-emitting element subcell, Light-emitting device.

9. In Paragraph 1, A transparent protective layer further provided on the scattering layer above, Light-emitting device.

10. In Paragraph 7, A transparent protective layer further provided on the above color filter, Light-emitting device.

11. A step of forming a light-emitting element layer on a first surface of a sapphire substrate; A step of connecting a power supply pad to the light-emitting element layer; A step of flattening a second surface opposite to the first surface of the sapphire substrate; and A step comprising forming a scattering layer on the second surface, Method for manufacturing a light-emitting device.

12. In Paragraph 11, The step of forming the scattering layer above is, A method comprising the step of forming the scattering layer by non-uniformly etching the second surface of the sapphire substrate. Method for manufacturing a light-emitting device.

13. In Paragraph 11, The step of forming the scattering layer above is, A step of forming a mask in an area excluding the region corresponding to the light-emitting element layer on the second surface of the sapphire substrate; A step comprising forming the scattering layer by low-temperature depositing gallium nitride in an area of ​​the second surface of the sapphire substrate where the mask is not formed. Method for manufacturing a light-emitting device.

14. In Paragraph 13, The step of forming the scattering layer above is, A method further comprising the step of non-uniformly etching one surface of gallium nitride formed on the second surface of the sapphire substrate. Method for manufacturing a light-emitting device.

15. In Paragraph 11, The step of forming the scattering layer above is, A step of forming a mask in an area excluding the region corresponding to the light-emitting element layer on the second surface of the sapphire substrate; A step comprising forming a scattering layer containing titanium dioxide (TiO2) particles in an area of ​​the second surface of the sapphire substrate where the mask is not formed. Method for manufacturing a light-emitting device.

16. In Paragraph 11, The step of forming the light-emitting element layer is, A method comprising the step of forming a light-emitting element layer including a COB (Chip on board) light-emitting element sub-cell, Method for manufacturing a light-emitting device.

17. In Paragraph 16, The method further comprises the step of forming a color filter on the scattering layer corresponding to the color of light emitted by the COB light-emitting element subcell. Method for manufacturing a light-emitting device.

18. In Paragraph 16, The step of forming the scattering layer above is, The method further comprises the step of additionally doping the scattering layer with an organic pigment or inorganic dye corresponding to the color of light emitted by the COB light-emitting element subcell. Method for manufacturing a light-emitting device.

19. In Paragraph 11, A step further comprising forming a transparent protective layer on the scattering layer, Method for manufacturing a light-emitting device.

20. In Paragraph 17, A step further comprising forming a transparent protective layer on the above color filter, Method for manufacturing a light-emitting device.

21. In any one of paragraphs 13 to 15, A method further comprising the step of cutting the sapphire substrate in an area where the scattering layer is not formed. Method for manufacturing a light-emitting device.

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