KR102601420B1 - Light-emitting diode including metal bulk - Google Patents

Abstract

A light emitting device according to an embodiment of the present invention includes a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, an active layer, and a plurality of grooves that penetrate the second conductivity type semiconductor layer and the active layer to expose the first conductivity type semiconductor layer. A light emitting structure including a portion, a first electrode located in the groove and electrically connected to the first conductivity type semiconductor layer, insulated from the first electrode, located on the lower surface of the second conductivity type semiconductor layer, and a second conductivity type semiconductor layer. a second electrode electrically connected to the first electrode, an insulating layer located on the lower surface and side surface of the first electrode and the lower surface and side surface of the second electrode, and having openings exposing the first electrode and the second electrode, respectively, and a lower surface of the insulating layer. and a first metal bulk, a second metal bulk, and insulation disposed on the sides of the first metal bulk and on the sides of the second metal bulk, which are located on the sides and spaced apart from each other and are electrically connected to the first electrode and the second electrode, respectively, through openings. It may include a support structure including a part. Additionally, the groove portion includes a first groove portion, and the first groove portion includes a first region, a second region, and a connection portion connecting the first region and the second region, and the first region is located on top of the first metal bulk. And the second region may be located on top of the second metal bulk.

Description

Light-emitting device including metal bulk {LIGHT-EMITTING DIODE INCLUDING METAL BULK}

The present invention relates to light-emitting devices, and particularly to light-emitting devices with improved luminous efficiency.

Recently, as the demand for small-sized, high-output light-emitting devices has increased, the demand for large-area flip-chip type light-emitting devices with excellent heat dissipation efficiency is increasing. The electrodes of the flip-chip type light-emitting device are directly bonded to the secondary substrate, and since no wire is used to supply external power to the flip-chip type light-emitting device, heat dissipation efficiency is very high compared to the horizontal light-emitting device. Therefore, even when a high-density current is applied, heat can be effectively conducted to the secondary substrate, so the flip-chip type light emitting device is suitable as a high-output light emitting source.

Additionally, for miniaturization and high output of light emitting devices, there is an increasing demand for chip scale packages that omit the process of packaging the light emitting device into a separate housing, etc. and use the light emitting device itself as a package. In particular, the electrodes of the flip chip type light emitting device can function similar to the leads of the package, so the flip chip type light emitting device can be usefully applied to such chip scale packages.

In chip-scale package structures, damage due to heat generated during high-current driving can be more critical. Therefore, external electrodes such as metal bulk are used to improve the reliability of the light-emitting device by facilitating heat dissipation, and a certain area of the light-emitting device needs to be secured by the external electrode.

Meanwhile, the light-emitting device receives power through an electrode electrically connected to the semiconductor layer and emits light. At this time, if the contact area between the semiconductor layer and the electrode is not sufficient or is located biased in some areas of the light emitting device, the externally applied current cannot be sufficiently diffused, and light emission occurs strongly only at specific locations of the semiconductor layer. Specifically, because the current applied through the metal bulk flows to the semiconductor layer only through some areas where the semiconductor layer and the electrode are in contact, light emission does not occur smoothly in other areas of the semiconductor layer that are not in contact with the electrode. Therefore, a problem of low luminous efficiency occurs.

Generally, when a substrate is removed from a light emitting device, stress and strain occur. The stress and strain are transmitted to the light emitting structure, and cracks are likely to occur in the light emitting structure. To solve this problem, a thick metal pad and a polymer such as EMC are placed under the light emitting structure, but even in such a case, there is a problem in that cracks occur mainly in the center of the light emitting structure adjacent to the top of the polymer.

Therefore, a light emitting device that has smooth heat dissipation, excellent mechanical properties, and improved current dispersion efficiency is required.

The problem to be solved by the present invention is to provide a light-emitting device with high luminous efficiency by improving current dispersion efficiency and securing a sufficient light-emitting area. In addition, the purpose is to provide a light-emitting device that ensures reliability by smoothly dissipating heat. In addition, the purpose is to prevent damage to the light emitting device due to stress and strain that occurs when separating the substrate.

A light emitting device according to an embodiment of the present invention includes a first conductivity type semiconductor layer, a second conductivity type semiconductor layer located on the lower surface of the first conductivity type semiconductor layer, the first conductivity type semiconductor layer and the second conductivity type semiconductor layer. A light emitting structure including an active layer located between semiconductor layers and a plurality of grooves penetrating the second conductivity type semiconductor layer and the active layer to expose the first conductivity type semiconductor layer, located within the groove portions, the first conductivity type semiconductor layer A first electrode electrically connected to the semiconductor layer, a second electrode insulated from the first electrode, located on the lower surface of the second conductive semiconductor layer, and electrically connected to the second conductive semiconductor layer, An insulating layer located on the bottom and side of the first electrode and the bottom and side of the second electrode, and having openings exposing the first and second electrodes, respectively, is spaced apart from the bottom and side of the insulating layer, Comprising a first metal bulk, a second metal bulk, and an insulating portion disposed on a side of the first metal bulk and a side of the second metal bulk, respectively, electrically connected to the first electrode and the second electrode through the openings. It may include a support structure. In addition, the groove portion includes a first groove portion, and the first groove portion includes a first region, a second region, and a connection portion connecting the first region and the second region, and the first region includes a first metal bulk. and the second region may be located at the top of the second metal bulk. Through this, the current dispersion efficiency of the light-emitting device is improved, and a sufficient light-emitting area can be secured, so the luminous efficiency of the light-emitting device can be improved.

The first electrode may be spaced apart from a side surface of the groove and may be formed along the shape of the groove. Through this, the first electrode can be insulated from the second conductive semiconductor layer and the active layer, a sufficient light-emitting area can be secured, and current dispersion efficiency can be improved.

The first electrode and the side surfaces of the groove may be spaced apart from each other at a certain distance.

The first area may be larger than the second area. In this case, the first electrode portion located within the first area is relatively small, so the light emitting area is not excessively narrowed. In addition, when separating the substrate, the stress and strain applied to the light emitting structure can be alleviated by a metallic material of sufficient area and thickness located at the bottom of the first region, thereby preventing cracks in the light emitting structure.

The first and second regions may be circular. In this case, the stress and strain generated when separating the substrate can be evenly distributed around the first part and the second part, so damage to the light emitting device can be reduced.

The groove portion may further include at least one second groove portion located on an upper portion of the first metal bulk. Through this, a sufficient area where the first electrode and the first conductive semiconductor layer are in contact can be secured, and current dispersion efficiency can be improved.

The gap between the second groove and the second metal bulk may be larger than the gap between the first area and the second metal bulk. Through this, a sufficient light-emitting area can be secured, and at the same time, the dispersion efficiency of the current applied through the first metal bulk can be improved.

The second groove may be circular. Since the stress and strain generated when separating the substrate can be evenly distributed around the first electrode in the second groove, damage to the light emitting device can be reduced.

According to the present invention, since the first groove exists over the upper part of the first metal bulk and the upper part of the second metal bulk, the current applied through the first electrode can be smoothly distributed within the light emitting device. Additionally, since a sufficient light-emitting area can be secured, light-emitting efficiency can be improved. In addition, damage to the light emitting device due to stress and strain that occurs when separating the substrate can be reduced.

1 is a plan view for explaining a light emitting device according to an embodiment of the present invention.
Figure 2 is an enlarged view of a portion (I) of a light emitting device according to an embodiment of the present invention.
Figures 3 and 4 are cross-sectional views for explaining a light-emitting device according to an embodiment of the present invention.
Figure 5 is a plan view (a) and a cross-sectional view (b) for explaining a method of manufacturing a light-emitting device according to another embodiment of the present invention.
Figure 6 is a plan view (a) and a cross-sectional view (b) for explaining a method of manufacturing a light emitting device according to another embodiment of the present invention.
Figure 7 is a plan view (a) and a cross-sectional view (b) for explaining a method of manufacturing a light emitting device according to another embodiment of the present invention.
Figure 8 is a plan view (a) and a cross-sectional view (b) for explaining a method of manufacturing a light emitting device according to another embodiment of the present invention.
Figure 9 is a plan view (a) and a cross-sectional view (b) for explaining a method of manufacturing a light emitting device according to another embodiment of the present invention.
Figure 10 is a plan view (a) and a cross-sectional view (b) for explaining a method of manufacturing a light emitting device according to another embodiment of the present invention.
Figure 11 is a plan view (a) and a cross-sectional view (b) for explaining a method of manufacturing a light emitting device according to another embodiment of the present invention.
Figure 12 is a plan view (a) and a cross-sectional view (b) for explaining a method of manufacturing a light emitting device according to another embodiment of the present invention.
Figure 13 is a plan view (a) and a cross-sectional view (b) for explaining a method of manufacturing a light emitting device according to another embodiment of the present invention.
Figure 14 is a plan view (a) and a cross-sectional view (b) for explaining a method of manufacturing a light emitting device according to another embodiment of the present invention.
Figure 15 is an exploded perspective view to explain an example of applying a light-emitting device according to an embodiment of the present invention to a lighting device.
Figure 16 is a cross-sectional view illustrating an example of applying a light-emitting device according to an embodiment of the present invention to a display device.
Figure 17 is a cross-sectional view illustrating an example of applying a light-emitting device according to an embodiment of the present invention to a display device.
Figure 18 is a cross-sectional view illustrating an example of applying a light-emitting device according to an embodiment of the present invention to a headlamp.

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. The embodiments introduced below are provided as examples so that the idea of the present invention can be sufficiently conveyed to those skilled in the art. Accordingly, the present invention is not limited to the embodiments described below and may be embodied in other forms. Also, in the drawings, the width, length, thickness, etc. of components may be exaggerated for convenience. Additionally, when one component is described as being "on top of" or "on" another component, it means that each component is "directly on" or "directly on" the other component, as well as when each component is described as being "directly on" or "directly on" the other component. This also includes cases where another component is interposed. Like reference numerals refer to like elements throughout the specification.

1 to 4 are plan views and cross-sectional views for explaining a light-emitting device according to an embodiment of the present invention. FIG. 1 is a plan view viewed from the top of the light emitting device, and FIG. 2 is an enlarged view for explaining a portion of the light emitting device of FIG. 1. FIG. 3 shows a cross section of a portion corresponding to line A-A' in FIG. 1. FIG. 4 shows a cross section of a portion corresponding to line B-B' in FIG. 1.

1 to 4, the light emitting device includes a light emitting structure 110, a second electrode 120, a first electrode 130, an insulating layer 140, and a support structure 210.

The light emitting structure 110 includes a first conductive semiconductor layer 111, a second conductive semiconductor layer 113 located on the lower surface of the first conductive semiconductor layer 111, and a first conductive semiconductor layer 111. It includes an active layer 112 located between the second conductive semiconductor layers 113. The first conductivity type semiconductor layer 111, the active layer 112, and the second conductivity type semiconductor layer 113 may include a IIIV series compound semiconductor, for example, nitride such as (Al, Ga, In)N. It may include a semiconductor. The first conductivity type semiconductor layer 111 may include an n-type impurity (e.g., Si), and the second conductivity type semiconductor layer 113 may include a p-type impurity (e.g., Mg). there is. Also, the opposite may be true. The active layer 112 may include a multi-quantum well structure (MQW), and its composition ratio may be determined to emit light of a desired peak wavelength.

The light emitting structure 110 may include at least one groove h that penetrates the second conductive semiconductor layer 113 and the active layer 112 and exposes the first conductive semiconductor layer 111. The groove h may be formed by partially removing the second conductive semiconductor layer 113 and the active layer 112. The side of the groove (h) may include an inclined side (D) as shown in FIGS. 3 and 4. The inclined side surface D of the groove h improves the extraction efficiency of light generated in the active layer 112. The first electrode 130, which will be described later, can be electrically connected to the first conductive semiconductor layer 111 through the groove h.

The groove portion (h) may include a first groove portion (h1). Referring to FIG. 2, the first groove h1 may include a first area h11, a second area h12, and a connection part h13. The second region h12 may be located in the opposite direction to the first region h11, and therefore, the portion located within the first groove h1 of the first electrode 130, which will be described later, is the first conductivity type semiconductor layer ( 111) can be contacted in a long area, and excessive bias to one side of the light emitting device can be prevented. Therefore, current dispersion efficiency can be improved, and thus luminous efficiency can be improved.

The first area h11 may be larger than the second area h12. For example, when the first area h11 and/or the second area h12 are circular, the radius of the first area h11 may be larger than the radius of the second area h12. In this case, the first part 131 located in the first area h11 of the first electrode 130, which will be described later, may be larger than the second part 132 located in the second area h12. Accordingly, the light emitting area is not excessively narrowed by the relatively small second part 132. In addition, the relatively large first area h11 allows the first part 131 and the light emitting structure 110 to contact each other in a wide area, and the first part 131 and the first metal bulk 211 also have a wide area. It can be accessed from the area. As a result, a metallic material of sufficient area and thickness may be positioned in the vertical direction below the area where the first part 131 and the light emitting structure 110 are in contact. In general, when the substrate is removed from the light emitting device, cracks occur mainly in the center of the light emitting structure 110 adjacent to the top of the insulating portion 213 located between the first metal bulk 211 and the second metal bulk 212. This is easy to happen. According to the present invention, the metallic material can be placed widely and thickly in the lower part of the center of the light emitting structure 110, so that when the substrate is separated, the stress and strain applied to the light emitting structure 110 are alleviated by the metallic material, thereby forming the light emitting structure 110. cracks can be prevented.

The groove portion (h) may further include at least one second groove portion (h2). The second groove h2 can increase the area where the first electrode 130 and the first conductive semiconductor layer 111 can be electrically connected. Therefore, by improving current dispersion efficiency, luminous efficiency can be improved.

The first electrode 130 may be located in the groove h. The first electrode 130 may be located on the lower surface of the first conductivity type semiconductor layer 111 exposed by the groove (h). Accordingly, the first electrode 130 can be electrically connected to the first conductive semiconductor layer 111. The first electrode 130 may be positioned at a constant distance from the side of the groove h. Accordingly, the first electrode 130 may be electrically insulated from the active layer 112 and the second conductive semiconductor layer 113. The separation space located between the first electrode 130 and the side of the groove h may be filled with an insulating layer 140, which will be described later. The height of the first electrode 130 may be less than or equal to the height of the groove h.

The first electrode 130 may be formed along the shape of the groove (h). For example, referring to FIGS. 1 and 2, when the groove h has a circular first region h11, a second region h12, and a linear connection portion h13, the first electrode 130 also It can have circular parts and linear parts along the shape.

The portion of the first electrode 130 located within the first groove h1 may include a first portion 131, a second portion 132, and a third portion 133. Although not limited thereto, the first part 131 and the second part 132 may be circular. In this case, the radius (R1) of the first part 131 may be about 22 to 24 ㎛, preferably 23 ㎛, and the radius (R2) of the second part 132 may be about 14 to 16 ㎛, preferably 23 ㎛. may be 15㎛. The second part 132 may be located in the opposite direction to the first part 131. When the first part 131 and the second part 132 are circular, the stress and strain generated when separating the substrate can be evenly distributed around the first part 131 and the second part 132, thereby producing light emission. Damage to the device may be reduced.

The first part 131 may be larger than the second part 132. Accordingly, current dispersion efficiency can be improved without excessively narrowing the light emission area, and thus light emission efficiency can be improved. For example, when the first part 131 and the second part 132 are circular, the radius R1 of the first part 131 may be larger than the radius R2 of the second part 132.

The third part 133 may connect the first part and the second part 131 and 132. Referring to FIG. 1, the third part 133 is linear and may be located between the first part and the second part 131 and 132. The line width (W) of the third portion 133 may be about 11 to 13 ㎛, and preferably 12 ㎛. When the above range is satisfied, a sufficient light-emitting area within the light-emitting device can be secured.

The first electrode 130 may include a highly reflective metal layer such as an Al layer, and the highly reflective metal layer may be formed on an adhesive layer such as Ti, Cr, or Ni. Additionally, a protective layer having a single or multiple layer structure of Ni, Cr, Au, etc. may be formed on the highly reflective metal layer. The first electrode 130 may have a multilayer structure of, for example, Ti/Al/Ti/Ni/Au. The first electrode 130 may be formed by depositing a metal material and patterning it.

The second electrode 120 is insulated from the first electrode 130 and may be located on the lower surface of the second conductive semiconductor layer 113. The second electrode 120 may be electrically connected to the second conductive semiconductor layer 113.

The second electrode 120 includes a reflective metal layer 121 and may further include a barrier metal layer 122. The barrier metal layer 122 may cover at least a portion of the lower surface of the reflective metal layer 121 . For example, by forming a pattern of the reflective metal layer 121 and forming the barrier metal layer 122 on the lower surface, the barrier metal layer 122 may be formed to cover the lower surface of the reflective metal layer 121. However, it is not necessarily limited to this, and the barrier metal layer 122 may cover the bottom and side surfaces of the reflective metal layer 121. For example, the reflective metal layer 121 may be formed by depositing and patterning Ag, Ag alloy, Ni/Ag, NiZn/Ag, or TiO/Ag layers. Meanwhile, the barrier metal layer 122 may be formed of Ni, Cr, Ti, Pt, W, or a composite layer thereof, and prevents the metal material of the reflective metal layer 121 from spreading or being contaminated. The second electrode 120 may include conductive oxide (ITO, indium tin oxide). The conductive oxide is made of a metal oxide with high light transmittance, and can improve luminous efficiency by suppressing absorption of light by the second electrode 120. A separate electrode cover layer may be disposed on the lower surface of the second electrode 120. The electrode cover layer serves to prevent adhesive materials such as solder from diffusing into the second electrode 120. The electrode cover layer may be made of the same material as the first electrode 130, but is not limited thereto.

The insulating layer 140 insulates the first electrode 130 from the second electrode 120 and serves to protect the light emitting structure 110 from external contaminants such as moisture. The insulating layer 140 may be located on the bottom and side of the first electrode 130 and the bottom and side of the second electrode 120. The insulating layer 140 may have openings 140a and 140b to allow electrical connection to the first conductivity type semiconductor layer 111 and the second conductivity type semiconductor layer 113 in a specific area. For example, the insulating layer 140 may have a first opening 140a exposing the first electrode 130 and a second opening 140b exposing the second electrode 120. Each of the first opening 140a and the second opening 140b may be filled with the first metal bulk 211 and the second metal bulk 212. Specifically, referring to FIGS. 1 to 4, the opening 140a may be located on the lower surface of the first part 131 and the lower surface of the portion of the first electrode located within the second groove h2. The insulating layer 140 may include an oxide film such as SiO ₂ , a nitride film such as SiN _x , or an insulating film such as MgF ₂ . Furthermore, the insulating layer 140 may include a distributed Bragg reflector (DBR) in which low-refractive material layers and high-refractive material layers are alternately stacked. For example, an insulating reflective layer with high reflectivity can be formed by stacking layers such as SiO ₂ /TiO ₂ or SiO ₂ /Nb ₂ O ₅ .

The light emitting device according to this embodiment may further include a stress buffering layer (not shown). The stress buffer layer may be located on the lower surface of the insulating layer 140. The adhesion between the stress buffer layer and the insulating part 213 may be higher than the adhesion between the insulating layer 140 and the insulating part 213. Therefore, compared to the case where the insulating portion 213 is formed on the lower surface of the insulating layer 140, when the insulating portion 213 is formed on the lower surface of the stress buffer layer, the probability of separation or peeling at the interface is greatly reduced. Accordingly, damage to the light emitting device due to peeling of the insulating portion 213 can be prevented, and reliability of the light emitting device can be improved. The stress buffering layer having the above-described effect exhibits stress relieving behavior and may further include an insulating material having an effect of improving adhesion. For example, the stress buffering layer may include at least one of polyimide, Teflon, benzocyclobutyne (BCB), and parylene. In particular, the stress buffer layer may include a photosensitive material (eg, polyimide), and when the stress buffer layer includes a photosensitive material, the stress buffer layer can be formed only through the process of developing the photosensitive material. Accordingly, a separate additional patterning process can be omitted, and the light emitting device manufacturing process can be simplified. The stress buffer layer may be in contact with the support structure 210. The stress buffer layer can be formed through deposition and patterning processes. Furthermore, the stress buffer layer and the insulating layer 140 may be patterned simultaneously.

The light emitting structure 110 may further include a roughened surface R. The roughened surface R can be formed using at least one of wet etching, dry etching, and electrochemical etching, for example, PEC etching or an etching method using an etching solution containing KOH and NaOH. It can be formed using Accordingly, the light emitting structure 110 may include protrusions and/or recesses of ㎛ to nm scale formed on the surface of the first conductivity type semiconductor layer 111. Light extraction efficiency of light emitted from the light emitting structure 110 may be improved by the roughened surface R.

The support structure 210 includes a seed metal 216, a first metal bulk 211, a second metal bulk 212, and an insulating portion 213, and further includes a first pad 214 and a second pad 215. ) and an insulating support 217 may be further included.

Referring to FIGS. 1 to 4, the seed metal 216 may be located on the lower surface of the light emitting structure 110, and are spaced apart from each other to form a lower portion of the first electrode 130 and a lower portion of the second electrode 120, respectively. It is located in and is electrically connected to the first electrode 130 and the second electrode 120, respectively. When plating the seed metal 216, the first metal bulk 211 is smoothly formed on the lower surface of the insulating layer 140 and the lower surface of the first electrode 130, and the second metal bulk 212 is formed on the insulating layer 140. It can be smoothly formed on the lower surface of the electrode 130 and the lower surface of the first electrode 130, and can play the same role as a UBM layer (under bump metallization layer). The seed metal 216 may include Ti, Cu, Au, Cr, Ni, etc. For example, the seed metal may have a Ti/Cu layered structure.

Referring to FIGS. 1 to 4, the first metal bulk 211 and the second metal bulk 212 may be located below the light emitting structure 110, and are spaced apart from each other to form the lower part of the first electrode 130 and the second metal bulk 212, respectively. It is located below the second electrode 120 and is electrically connected to the first electrode 130 and the second electrode 120, respectively. The first and second metal bulks 211 and 212 are made of a metal material and refer to components whose thickness is generally greater than the thickness of the light emitting structure 110. The first metal bulk 211 and the second metal bulk 212 may have a thickness of several tens of micrometers or more. The first metal bulk 211 and the second metal bulk 212 may be electrically connected to the first electrode 130 and the second electrode 120, respectively, through the openings 140a and 140b, through which the first conductive It may be electrically connected to the type semiconductor layer 111 and the second conductivity type semiconductor layer 113. The first and second metal bulks 211 and 212 can effectively radiate heat generated in the light emitting structure 110 to the outside, and may include a material whose thermal expansion coefficient is similar to that of the light emitting structure 110. . The lower surfaces of the first metal bulk 211 and the second metal bulk 212 may have a rectangular shape, but are not limited thereto, and may have a polygonal shape as shown in FIG. 1. Alternatively, the lower surfaces of the first metal bulk 211 and the second metal bulk 212 may each include a concave portion or a convex portion having one side engaged with each other, in which case the penetration of external contaminants can be more effectively prevented. there is.

The first metal bulk 211 may have a larger area than the second metal bulk 212. Specifically, the area of the first metal bulk 211 is larger than the area of the second metal bulk 212, and may cover the center of the lower surface of the light emitting structure 110. Generally, when moving an individual light-emitting device in a packaging process, etc., an ejector pin located at the bottom of the light-emitting device pushes the center of the bottom of the light-emitting device to raise the light-emitting device, and the pushed up light-emitting device requires separate equipment. is moved through Therefore, when the first metal bulk 211 covers the center of the lower surface of the light emitting structure 110, the light emitting structure 110 can be prevented from directly contacting the ejector pin, so that the light emitting device by the ejector pin Damage can be reduced. Additionally, because the first metal bulk 211 is relatively large, the length of the third portion 133 of the first electrode 130 can be prevented from becoming excessively long. Accordingly, when a high current is applied to the light emitting device, a portion of the first electrode 130 can be prevented from acting as a high resistance, and current dispersion efficiency can be improved. The first area h11 may be formed on an upper part of the first metal bulk 211, and the second area h12 may be formed on an upper part of the second metal bulk 212. Accordingly, since the area where the first electrode 130 and the first conductive semiconductor layer 111 are in contact may not be excessively biased toward one side of the light emitting device, current dispersion efficiency can be improved.

The insulating portion 213 may be disposed between the first metal bulk 211 and the second metal bulk 212. The insulating portion 213 insulates the first and second metal bulks 211 and 212, thereby insulating the first and second electrodes 130 and 120, and insulating the first and second metal bulks 211 and 212. It fills the space between (212) to improve durability and serves to relieve stress that occurs during thermal expansion of the first and second metal bulks (211, 212). Additionally, as shown in FIGS. 3 and 4, the insulating portion 213 is not only between the first metal bulk 211 and the second metal bulk 212, but also on the side of the first metal bulk 211 and the second metal bulk. It may be located on the side of 212 and have a structure surrounding the first and second metal bulks 211 and 212. Through this, the light emitting device can be protected from external contaminants or shocks. The insulating portion 213 may include epoxy molding compound (EMC). When the first pad 214 and the second pad 215 are located on the lower surface of the first metal bulk 211 and the lower surface of the second metal bulk 212, the insulating portion 213 is connected to the first pad 214. It may be formed to cover the side surface of and the side surface of the second pad 215 .

The light emitting device of the present invention may further include an insulating support 217. The insulating support 217 may cover the lower surface of the insulating portion 213, a partial area of the lower surface of the first metal bulk 211, and a partial area of the lower surface of the second metal bulk 212. Specifically, the insulating support 217 may include exposed areas that partially expose the lower surface of the first metal bulk 211 and the lower surface of the second metal bulk 211, respectively. When a light emitting device is mounted on a circuit board using an adhesive material such as solder, the insulating support 217 can prevent the solder from being unnecessarily separated through exposed areas. Additionally, when the light emitting device includes the first pad 214 and the second pad 215, the position where the first pad 214 and the second pad 215 are formed can be specified. The insulating support 217 may be made of a general material used in photo solder resist, but is not limited thereto. The insulating support 217 may be formed of the same material as the insulating part 213, and in this case, it may be formed together when the insulating part 213 is formed.

The light emitting device of the present invention may further include a first pad 214 and a second pad 215. The first pad 214 and the second pad 215 may be located on the lower surfaces of the first and second metal bulks 211 and 212. The first pad 214 and the second pad 215 function as external terminals of the device when the light emitting device is mounted on the board using an adhesive material such as solder, and the adhesive material is used to form the first and second metal bulks. It plays a role in preventing the spread to (211, 212). The first and second metal bulks 211 and 212 may be formed of Ni, Pd, etc. The gap between the first pad 214 and the second pad 215 may be larger than the gap between the first metal bulk 211 and the second metal bulk 212. In this case, the adhesive material is effectively prevented from short-circuiting the first pad 214 and the second pad 215, and the stability of the light emitting device can be improved. The horizontal and vertical lengths of the first pad 214 and the second pad 215 may be the same, but are not limited thereto.

5 to 14 are plan views (a) and cross-sectional views (b) for explaining a method of manufacturing a light-emitting device according to another embodiment of the present invention. The drawing direction for explaining the manufacturing method of the light emitting device of FIGS. 5 to 14 is opposite to the drawing direction for explaining the light emitting device of FIGS. 1 to 4. That is, the vertical direction of FIGS. 5 to 14 is opposite to the vertical direction of FIGS. 1 to 4. Hereinafter, in the description referring to FIGS. 5 to 14, ‘upper surface’ and ‘lower surface’ are expressions limited to FIGS. 5 to 14, and have the opposite meaning to ‘upper surface’ and ‘lower surface’ of FIGS. 1 to 4.

Referring to FIG. 5, a first conductivity type semiconductor layer 111, an active layer 112, and a second conductivity type semiconductor layer 113 are sequentially formed on the upper surface of the substrate 100. The substrate 100 is not limited as long as it is a substrate on which the light emitting structure 110 can be grown. For example, the substrate 100 may be a sapphire substrate, a silicon carbide substrate, a silicon substrate, a gallium nitride substrate, an aluminum nitride substrate, etc. The first conductive semiconductor layer 111, the active layer 112, and the second conductive semiconductor layer 113 are formed on the substrate 100 using a technology such as metal organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE). ) can be grown on

Referring to FIG. 6, a groove h may be formed in the light emitting structure 110. Specifically, the groove h may be formed by patterning the second conductive semiconductor layer 113 and the active layer 112 so that the first conductive semiconductor layer 111 is exposed. The side of the groove h may be formed to be inclined by using a technique such as photoresist reflow. At this time, the second conductive semiconductor layer 113 and the active layer 112 may be patterned so that the first region h11 of the first groove h1 is formed larger than the second region h12.

Referring to FIG. 7 , the second electrode 120 may be formed on the upper surface of the second conductivity type semiconductor layer 113. Specifically, the reflective metal layer 121 and the barrier metal layer 122 may be formed on the upper surface of the second conductive semiconductor layer 113. The reflective metal layer 121 and the barrier metal layer 122 may be formed using techniques such as electron beam deposition, vacuum deposition, sputtering, or metal organic chemical vapor deposition (MOCVD). Specifically, the pattern of the reflective metal layer 121 may be formed first, and then the barrier metal layer 122 may be formed thereon.

Referring to FIG. 8, the first electrode 130 may be formed in the groove h. The first electrode 130 may be formed along the shape of the groove h using a mask. The first electrode 130 may be formed using a technique such as electron beam deposition, vacuum deposition, sputter, or metal organic chemical vapor deposition (MOCVD).

Referring to FIG. 9 , the insulating layer 140 may be formed on the top and side surfaces of the first electrode 130 and the top and side surfaces of the second electrode 120. The insulating layer 140 may be formed as a single layer or multiple layers using a technology such as chemical vapor deposition (CVD). The first opening 140a and the second opening 140b may be formed using a mask or through etching after depositing the insulating layer 140, but are not limited thereto.

Referring to FIGS. 10 and 11 , the seed metal 216 and the first and second metal bulks 211 and 212 may be formed on the insulating layer 140 . A mask is formed on the upper surface of the insulating layer 140, and the mask masks a portion corresponding to the area where the insulating portion 213 is formed, and the seed metal 216 and the first and second metal bulks 211 and 212 are formed. ) opens the area where it is formed. Specifically, since the upper part of the first region (h11) of the first groove (h1) is opened by the mask, the seed metal 216 and the first metal bulk 211 will be formed on the upper part of the first region (h11). The location can be specified so that Next, the seed metal 216 is formed in the open area of the mask by a method such as sputtering, and the first metal bulk 211 and the second metal bulk 212 are formed on the seed metal 216 through a plating process. . Afterwards, by removing the mask through an etching process, the seed metal 216 and the first and second metal bulks 211 and 212 can be provided in a desired shape.

As another method, the first and second metal bulks 211 and 212 are formed using a screen printing method as follows. A UBM layer is formed on at least a portion of the first opening 140a and the second opening 140b through a deposition and patterning method such as sputtering, or a deposition and lift-off method. The UBM layer may be formed on the area where the first and second metal bulks 211 and 212 will be formed, and may include a (Ti or TiW) layer and a (Cu, Ni, Au single layer or combination) layer. there is. For example, the UBM layer may have a Ti/Cu stacked structure. Next, a mask is formed, where the mask masks a portion corresponding to the area where the insulating portion 213 is formed and opens the area where the first and second metal bulks 211 and 212 are formed. In this case as well, the top of the first region h11 of the first groove h1 is opened by a mask so that the first metal bulk 211 can be formed on the top of the first region h11. Next, materials such as Ag paste, Au paste, and Cu paste are formed in the open area through a screen printing process and are cured. Afterwards, the first and second metal bulks 211 and 212 can be provided by removing the mask through an etching process.

Referring to FIG. 12 , the insulating portion 213 may be disposed between the first metal bulk 211 and the second metal bulk 212. The insulating portion 213 may be formed through a printing or coating process. The insulating portion 213 may be coated to cover the upper surface of the first metal bulk 211 and the upper surface of the second metal bulk 212. In this case, the upper surface of the insulating portion 213 may be coated with lapping or chemical coating. It may be flattened through mechanical polishing (CMP) or the like, and the first and second metal bulks 211 and 212 may be exposed.

When the light emitting device of the present invention further includes an insulating support 217, a first pad 214, and a second pad 215, Figures 13 and 14 show the insulating support 217, the first pad 214, and the second pad 215. A method of forming the second pad 215 is shown. According to FIG. 13, the insulating support 217 may be formed on the upper surface of the insulating portion 213 through a printing or coating process, and may be formed on a partial area of the upper surface of the first metal bulk 211 and the first metal bulk 211 using a mask, etc. 2 Some areas of the upper surface of the metal bulk 212 may be opened. Referring to FIG. 14, the first pad 214 and the second pad 215 are deposited on the first metal bulk 214 through electron beam deposition, vacuum deposition, sputtering, or metal organic chemical vapor deposition (MOCVD). It may be formed on the upper surface and the upper surface of the second metal bulk 215. Furthermore, the first pad 214 and the second pad 215 are formed only on the exposed area of the upper surface of the first metal bulk 214 and the exposed area of the upper surface of the second metal bulk 215 opened through a mask or the like. It can be.

After the support structure 210 is formed, the substrate 100 may be separated from the light emitting structure 110 and removed using a known technique such as laser lift off.

Figure 15 is an exploded perspective view to explain an example of applying a light-emitting device according to an embodiment of the present invention to a lighting device.

Referring to FIG. 15, the lighting device according to this embodiment includes a diffusion cover 1010, a light emitting device module 1020, and a body portion 1030. The body portion 1030 may accommodate the light emitting device module 1020, and the diffusion cover 1010 may be disposed on the body portion 1030 to cover the top of the light emitting device module 1020.

The body portion 1030 is not limited as long as it can accommodate and support the light emitting device module 1020 and supply electrical power to the light emitting device module 1020. For example, as shown, the body portion 1030 may include a body case 1031, a power supply device 1033, a power case 1035, and a power connection unit 1037.

The power supply device 1033 is accommodated in the power case 1035 and is electrically connected to the light emitting device module 1020, and may include at least one IC chip. The IC chip can adjust, convert, or control the characteristics of the power supplied to the light emitting device module 1020. The power case 1035 may accommodate and support the power supply device 1033, and the power case 1035 with the power supply device 1033 fixed therein may be located inside the body case 1031. . The power connection unit 115 may be disposed at the bottom of the power case 1035 and coupled to the power case 1035. Accordingly, the power connection unit 115 is electrically connected to the power supply device 1033 inside the power case 1035 and can serve as a passage through which external power can be supplied to the power supply device 1033.

The light emitting device module 1020 includes a substrate 1023 and a light emitting device 1021 disposed on the substrate 1023. The light emitting device module 1020 may be provided on the upper part of the body case 1031 and electrically connected to the power supply device 1033.

The substrate 1023 is not limited as long as it can support the light emitting device 1021, and may be, for example, a printed circuit board including wiring. The substrate 1023 may have a shape corresponding to the fixing portion on the upper part of the body case 1031 so that it can be stably fixed to the body case 1031. The light emitting device 1021 may include at least one of the light emitting devices according to the embodiments of the present invention described above.

The diffusion cover 1010 may be placed on the light emitting device 1021 and may be fixed to the body case 1031 to cover the light emitting device 1021. The diffusion cover 1010 may be made of a light-transmitting material, and the directivity characteristics of the lighting device may be adjusted by adjusting the shape and light transmittance of the diffusion cover 1010. Therefore, the diffusion cover 1010 may be transformed into various forms depending on the purpose of use and application of the lighting device.

Figure 16 is a cross-sectional view illustrating an example of applying a light-emitting device according to an embodiment of the present invention to a display device.

The display device of this embodiment includes a display panel 2110, a backlight unit (BLU1) that provides light to the display panel 2110, and a panel guide 2100 that supports a lower edge of the display panel 2110.

The display panel 2110 is not particularly limited and may be, for example, a liquid crystal display panel including a liquid crystal layer. A gate driving PCB that supplies a driving signal to the gate line may be further positioned at the edge of the display panel 2110. Here, the gate driving PCBs 2112 and 2113 may not be formed on a separate PCB but may be formed on a thin film transistor substrate.

The backlight unit BLU1 includes a light source module including at least one substrate 2150 and a plurality of light emitting devices 2160. Furthermore, the backlight unit BLU1 may further include a bottom cover 2180, a reflective sheet 2170, a diffusion plate 2131, and optical sheets 2130.

The bottom cover 2180 is opened upward and can accommodate the substrate 2150, the light emitting element 2160, the reflective sheet 2170, the diffusion plate 2131, and the optical sheets 2130. Additionally, the bottom cover 2180 may be combined with the panel guide 2100. The substrate 2150 may be located below the reflective sheet 2170 and surrounded by the reflective sheet 2170. However, it is not limited to this, and if a reflective material is coated on the surface, it may be located on the reflective sheet 2170. In addition, the substrate 2150 may be formed in plurality, and the plurality of substrates 2150 may be arranged side by side, but the present invention is not limited to this and may be formed as a single substrate 2150.

The light emitting device 2160 may include at least one of the light emitting devices according to the embodiments of the present invention described above. The light emitting elements 2160 may be regularly arranged in a certain pattern on the substrate 2150. Additionally, a lens 2210 is disposed on each light-emitting device 2160 to improve the uniformity of light emitted from the plurality of light-emitting devices 2160.

The diffusion plate 2131 and the optical sheets 2130 are located on the light emitting device 2160. Light emitted from the light emitting device 2160 may be supplied to the display panel 2110 in the form of a planar light source through the diffusion plate 2131 and the optical sheets 2130.

As such, the light emitting device according to the embodiments of the present invention can be applied to a direct display device such as the present embodiment.

Figure 17 is a cross-sectional view for explaining an example of applying a light-emitting device according to an embodiment to a display device.

A display device equipped with a backlight unit according to this embodiment includes a display panel 3210 on which an image is displayed, and a backlight unit BLU2 disposed on the back of the display panel 3210 and emitting light. Furthermore, the display device includes a frame 240 that supports the display panel 3210 and houses the backlight unit BLU2, and covers 3240 and 3280 that surround the display panel 3210.

The display panel 3210 is not particularly limited and may be, for example, a liquid crystal display panel including a liquid crystal layer. A gate driving PCB that supplies a driving signal to the gate line may be further positioned at the edge of the display panel 3210. Here, the gate driving PCB may not be formed on a separate PCB but may be formed on a thin film transistor substrate. The display panel 3210 is fixed by covers 3240 and 3280 located at the top and bottom, and the cover 3280 located at the bottom can be coupled to the backlight unit BLU2.

The backlight unit (BLU2) that provides light to the display panel 3210 includes a lower cover 3270 with a portion of the upper surface opened, a light source module disposed on one inner side of the lower cover 3270, and a light source module positioned in parallel with the light source module. It includes a light guide plate 3250 that converts point light into surface light. In addition, the backlight unit (BLU2) of this embodiment includes optical sheets 3230 that are located on the light guide plate 3250 to diffuse and converge light, and are disposed below the light guide plate 3250 and travel in the lower direction of the light guide plate 3250. It may further include a reflective sheet 3260 that reflects light toward the display panel 3210.

The light source module includes a substrate 3220 and a plurality of light emitting elements 3110 arranged on one surface of the substrate 3220 at regular intervals. The substrate 3220 is not limited as long as it supports the light emitting device 3110 and is electrically connected to the light emitting device 3110. For example, it may be a printed circuit board. The light emitting device 3110 may include at least one light emitting device according to the embodiments of the present invention described above. Light emitted from the light source module is incident on the light guide plate 3250 and supplied to the display panel 3210 through the optical sheets 3230. Through the light guide plate 3250 and the optical sheets 3230, a point light source emitted from the light emitting elements 3110 may be transformed into a planar light source.

In this way, the light emitting device according to the embodiments of the present invention can be applied to an edge-type display device such as this embodiment.

Figure 18 is a cross-sectional view illustrating an example of applying a light-emitting device according to an embodiment of the present invention to a headlamp.

Referring to FIG. 18, the headlamp includes a lamp body 4070, a substrate 4020, a light emitting element 4010, and a cover lens 4050. Furthermore, the headlamp may further include a heat dissipation unit 4030, a support rack 4060, and a connection member 4040.

The substrate 4020 is fixed by a support rack 4060 and spaced apart from the lamp body 4070. The substrate 4020 is not limited as long as it can support the light emitting device 4010, and may be, for example, a substrate with a conductive pattern such as a printed circuit board. The light emitting device 4010 is located on the substrate 4020 and can be supported and fixed by the substrate 4020. Additionally, the light emitting device 4010 can be electrically connected to an external power source through the conductive pattern of the substrate 4020. Additionally, the light emitting device 4010 may include at least one light emitting device according to the embodiments of the present invention described above.

The cover lens 4050 is located on the path along which light emitted from the light emitting device 4010 travels. For example, as shown, the cover lens 4050 may be arranged to be spaced apart from the light-emitting device 4010 by the connecting member 4040, and may be placed in a direction to provide light emitted from the light-emitting device 4010. You can. The beam angle and/or color of light emitted from the headlamp to the outside may be adjusted by the cover lens 4050. Meanwhile, the connecting member 4040 fixes the cover lens 4050 to the substrate 4020 and may also serve as a light guide that is arranged to surround the light emitting element 4010 and provides a light emission path 4045. At this time, the connecting member 4040 may be formed of a light-reflective material or coated with a light-reflective material. Meanwhile, the heat dissipation unit 4030 may include a heat dissipation fin 4031 and/or a heat dissipation fan 4033, and radiates heat generated when the light emitting device 4010 is driven to the outside.

As such, the light-emitting device according to the embodiments of the present invention can be applied to a headlamp like this embodiment, especially a headlamp for a vehicle.

Claims (15)

A first conductive semiconductor layer, a second conductive semiconductor layer located on the lower surface of the first conductive semiconductor layer, an active layer located between the first conductive semiconductor layer and the second conductive semiconductor layer, and the second conductive semiconductor layer. A light emitting structure including a conductive semiconductor layer and at least one groove that penetrates the active layer and exposes a first conductive semiconductor layer;
a first electrode electrically connected to the first conductivity type semiconductor layer in the groove portion;
a second electrode insulated from the first electrode, located below the second conductive semiconductor layer, and electrically connected to the second conductive semiconductor layer;
a first metal bulk disposed below the first electrode;
a second metal bulk disposed below the second electrode; and
an insulating layer disposed between the first metal bulk and the second metal bulk and the light emitting structure, and covering side surfaces of the first electrode and the second electrode to insulate the first electrode from the second electrode; Including,
The first metal bulk and the second metal bulk are formed to be spaced apart from each other,
The groove portion includes one area and another area formed to have a width smaller than the one area,
The first metal bulk covers the portion of the groove portion.
In claim 1,
The first metal bulk and the second metal bulk are rectangular in shape.
In claim 1,
The first electrode is a light emitting device formed along the groove.
In claim 1,
The first electrode is a light emitting device formed in the groove portion.
In claim 1,
A light emitting device wherein the first electrode includes Al.
In claim 1,
A light emitting device wherein the height of the first electrode is less than or equal to the height of the groove.
In claim 1,
The second electrode is a light emitting device formed of a single layer or a composite layer containing at least one of Ag, Ni, Cr, Ti, Pt, and W.
In claim 1,
The second electrode further includes a reflective metal layer and a barrier metal layer covering at least a portion of a lower surface of the reflective metal layer.
In claim 8,
The barrier metal layer is a light emitting device formed of a single layer or a composite layer containing at least one of Ni, Cr, Ti, Pt, and W.
In claim 1,
The insulating layer includes a first opening and a second opening,
The first metal bulk and the first conductive semiconductor layer are electrically connected to each other through the first opening,
A light emitting device in which the second metal bulk and the second conductive semiconductor layer are electrically connected to each other through the second opening.
In claim 1,
A light emitting device wherein a side surface of the second conductive semiconductor layer and a side surface of the active layer include an inclined surface.
In claim 1,
A light emitting device wherein the insulating layer includes at least one of an oxide film, a nitride film, and an insulating film.
In claim 12,
A light _emitting device wherein the oxide film includes _{SiO 2} , the nitride film includes SiN
In claim 1,
A light emitting device further comprising an insulating part disposed between the first metal bulk and the second metal bulk to insulate the first metal bulk and the second metal bulk from each other.
In claim 14,
The insulating portion is formed to surround the sides of the first metal bulk and the second metal bulk.

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