KR20160056524A - Light emitting device - Google Patents

Abstract

Disclosed is a light emitting device having uniform luminous characteristics and securing excellent heat dissipation efficiency. The light emitting device includes: a light emitting structure; a first contact electrode and a second contact electrode disposed on the light emitting structure and making ohmic contact with first and second conductive type semiconductor layers, respectively; a first insulation part and a second insulation part for partially covering the first contact electrode and the second contact electrode; a first electrode and a second electrode disposed on the light emitting structure and electrically connected to the first and second contact electrodes, respectively; a third insulation part for covering the side surfaces of the first electrode and the second electrode; a connection layer disposed on the first electrode, the second electrode, and the third insulation part; and a first pad electrode and a second pad electrode disposed on the connection layer, wherein the first pad electrode and the second pad electrode are electrically connected to the first electrode and the second electrode through the connection layer, respectively. A horizontal area of the first pad electrode is smaller than a horizontal area of the first electrode, and a horizontal area of the second pad electrode is bigger than a horizontal area of the second electrode.

Description

[0001] LIGHT EMITTING DEVICE [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting device, and more particularly, to a light emitting device including an electrode capable of improving thermal characteristics, electrical characteristics, and light emitting characteristics of the light emitting device.

In recent years, there is an increasing demand for a small-sized high-output light-emitting device, and a demand for a large-area flip-chip type light-emitting device having excellent heat dissipation efficiency is increasing. Since the electrode of the flip chip type light emitting device is directly bonded to the secondary substrate and the wire for supplying external power to the flip chip type light emitting device is not used, the heat emission efficiency is much higher than that of the horizontal type light emitting device. Therefore, even when a high-density current is applied, the heat can be effectively conducted to the secondary substrate side, so that the flip chip type light emitting device is suitable as a high output light emitting source.

Further, in order to reduce the size of the light emitting device, there is an increasing demand for a chip scale package that uses the light emitting device itself as a package, omitting the step of packaging the light emitting device into a separate housing or the like. The electrode of the flip chip type light emitting device can function similar to the lead of the package, and a flip chip type light emitting device can be applied to such a chip scale package.

When such a chip scale package type device is used as a high output light emitting device, a high density current is applied to the chip scale package. In this case, when the high-output chip-scale package is driven, the current leaks into the region where the N-type electrode is formed. Therefore, the light emission of the chip scale package is concentrated in the region where the N-type electrode is formed, and heat is also exerted in this portion. As described above, light emission and heat generation are concentrated in a specific region of the light emitting device, resulting in non-uniformity of light emission and lowered heat emission efficiency from the light emitting device, which adversely affects the reliability and lifetime of the light emitting device.

A problem to be solved by the present invention is to provide a light emitting device having uniform light emission characteristics throughout the light emitting device and having excellent heat emission efficiency.

A light emitting device according to an aspect of the present invention includes a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer disposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer Structure; A first contact electrode and a second contact electrode located on the light emitting structure and ohmically contacting the first and second conductive type semiconductor layers, respectively; First and second insulating portions partially covering the first contact electrode and the second contact electrode; A first electrode and a second electrode that are disposed on the light emitting structure and are electrically connected to the first and second contact electrodes, respectively; A third insulating portion covering the side surfaces of the first electrode and the second electrode; A connection layer located on the first electrode, the second electrode and the third insulation portion; And a first pad electrode and a second pad electrode located on the connection layer, wherein the first pad electrode and the second pad electrode are electrically connected to the first electrode and the second electrode through the connection layer, respectively, Wherein a horizontal area of the first pad electrode is smaller than a horizontal area of the first electrode and a horizontal area of the second pad electrode is larger than a horizontal area of the second electrode.

Accordingly, the heat emission efficiency of the light emitting device can be improved, reliability and lifetime can be improved, and a light emitting device having uniform light emitting characteristics can be provided.

The first electrode may be located on a portion where the first contact electrode and the first conductivity type semiconductor layer are in ohmic contact with each other.

In addition, under the second electrode, a portion where the first contact electrode and the first conductivity type semiconductor layer are in ohmic contact may not be located.

The first contact electrode may include a plurality of ohmic contact regions that are in ohmic contact with the first conductivity type semiconductor layer and the first electrode is in contact with all of the plurality of ohmic contact regions of the first contact electrode, .

The first contact electrode may include a plurality of ohmic contact regions that are in ohmic contact with the first conductivity type semiconductor layer, and only a portion of the plurality of ohmic contact regions may contact the first electrode.

Further, the light emitting element may include: a first wiring layer located under the first electrode; And a second wiring layer positioned below the second electrode, wherein a part of the first wiring layer can contact the first contact electrode, and a part of the second wiring layer is connected to the second contact electrode, .

And a part of the second insulating portion may be located between the first wiring layer and the first contact electrode.

The horizontal cross-sectional area of the first electrode may be 0.8 times or more and less than 1 times the sum of the horizontal cross-sectional areas of the first electrode and the second electrode.

The horizontal area of the first pad electrode and the horizontal area of the second pad electrode may be the same.

The connection layer comprising: an insulating material layer; A first connection layer electrically connecting the first electrode and the first pad electrode, the first connection layer penetrating the insulating material layer; And a second connection layer electrically connecting the second electrode and the second pad electrode and penetrating the insulating material layer.

The second electrodes may be formed in pluralities, and the second electrodes may be electrically connected to the second pad electrodes.

Further, the first contact electrode may include a plurality of ohmic contact regions which are in ohmic contact with the first conductivity type semiconductor layer, and a part of the plurality of ohmic contact regions is disposed between the second electrodes .

Each of the first and second electrodes may include metal particles and a non-metallic material interposed between the metal particles.

Further, the metal particles and the non-metallic material may be formed in the form of a metal particle sintered body.

Each of the first electrode and the second electrode may include an inclined side surface and the inclined side surface may include a side surface where a tangential slope of a vertical section of each of the first electrode and the second electrode changes.

In addition, each of the first electrode and the second electrode may include 80 to 98 wt% of metal particles.

In some embodiments, the light emitting device may further include a region where the active layer and the second conductive type semiconductor layer are partially removed to partially expose the first conductivity type semiconductor layer, The first contact electrode may be in ohmic contact with the first conductive type semiconductor layer through a region where the first conductive type semiconductor layer is partially exposed.

Also, the region in which the first conductivity type semiconductor layer is partially exposed may be formed in a plurality of holes.

Further, the second contact electrode may be located on the second conductive type semiconductor layer, and the first insulating portion may cover the second contact electrode and the light emitting structure, And the first contact electrode may include a first opening and a second opening that respectively expose a portion of the second contact electrode and a portion of the second contact electrode, the first contact electrode at least partially covers the first insulating portion, 1 conductive type semiconductor layer, and the second insulating portion partially covers the first contact electrode, and has a third opening portion partially exposing the first contact electrode and a third opening portion partially corresponding to the position of the second opening portion And a fourth opening exposing a portion of the second contact electrode.

The first electrode may contact the first contact electrode through the third opening and the second electrode may contact the second contact electrode through the fourth opening, And may be located below the area of the third opening.

According to the present invention, by including the first electrode having a relatively large horizontal cross-sectional area as compared with the second electrode, the efficiency of heat emission of the light emitting device can be improved, and reliability and lifetime can be improved. In addition, the ratio of the area occupied by the first electrode in the light emitting element is increased, so that the light emitting element having uniform light emitting characteristics throughout the light emitting element can be provided.

1 and 2 are plan and sectional views for explaining a light emitting device according to an embodiment of the present invention.
3 is a cross-sectional view illustrating a light emitting device according to another embodiment of the present invention.
4 and 5 are a plan view and a cross-sectional view for illustrating a light emitting device according to another embodiment of the present invention.
6 and 7 are a plan view and a sectional view for explaining a light emitting device according to another embodiment of the present invention.
8 and 9 are plan views and cross-sectional views for explaining a light emitting device according to another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are provided by way of example so that those skilled in the art can sufficiently convey the spirit of the present invention. Therefore, the present invention is not limited to the embodiments described below, but may be embodied in other forms. In the drawings, the width, length, thickness, etc. of components may be exaggerated for convenience. It is also to be understood that when an element is referred to as being "above" or "above" another element, But also includes the case where another component is interposed between the two. Like reference numerals designate like elements throughout the specification.

1 and 2 are plan and sectional views for explaining a light emitting device according to an embodiment of the present invention.

1B is a plan view for explaining the position of the hole 120h and the positions of the third opening 153a and the fourth opening 153b and FIG. 2 is a cross-sectional view showing a cross-section of a region corresponding to line AA in Figs. 1 (a) and 1 (b).

1 and 2, a light emitting device 100a includes a light emitting structure 120 including a first conductivity type semiconductor layer 121, an active layer 123, and a second conductivity type semiconductor layer 125, The second contact electrode 140, the first and second insulating parts 151 and 153, the first electrode 161, the second electrode 163, and the third insulating part 170 . Furthermore, the light emitting device 100a may further include first and second pad electrodes (not shown), a growth substrate (not shown), and a wavelength conversion unit (not shown).

The light emitting structure 120 includes a first conductivity type semiconductor layer 121, an active layer 123 located on the first conductivity type semiconductor layer 121, and a second conductivity type semiconductor layer 125). The first conductivity type semiconductor layer 121, the active layer 123 and the second conductivity type semiconductor layer 125 may include a III-V compound semiconductor, for example, (Al, Ga, In) N, And may include the same nitride-based semiconductor. The first conductivity type semiconductor layer 121 may include an n-type impurity (for example, Si) and the second conductivity type semiconductor layer 125 may include a p-type impurity (for example, Mg) have. It may also be the opposite. The active layer 123 may comprise a multiple quantum well structure (MQW).

The light emitting structure 120 may include a region where the second conductivity type semiconductor layer 125 and the active layer 123 are partially removed and the first conductivity type semiconductor layer 121 is partially exposed. The light emitting structure 120 may include at least one hole 120h through which the first conductivity type semiconductor layer 121 is exposed through the second conductivity type semiconductor layer 125 and the active layer 123. For example, ).

The holes 120h may be formed in a plurality of holes, and the holes 120h may be arranged in a substantially regular manner. For example, as shown in FIG. 1, the holes 120h may be arranged to have a constant pattern at regular intervals. By arranging the holes 120h regularly throughout the whole of the light emitting structure, the current can be evenly distributed in the horizontal direction when the light emitting element 100a is driven. However, the present invention is not limited thereto, and the arrangement and the number of the holes 120h may be variously modified.

In addition, the exposed form of the first conductivity type semiconductor layer 121 is not limited to the hole 120h. For example, the exposed region of the first conductive semiconductor layer 121 may be formed in a line shape, a combination of holes and lines, or the like. The light emitting structure 120 is formed along the line and the active layer 123 and the second conductivity type semiconductor layer 125 are formed in a plurality of lines, As shown in FIG. Therefore, in the present embodiment, the present invention is described with reference to the light emitting structure 120 including a plurality of holes 120h, but the present invention is not limited thereto.

The light emitting structure 120 may further include a roughness 120R formed on the bottom surface thereof. The roughness 120R may be formed using at least one of wet etching, dry etching, and electrochemical etching. For example, the roughness 120R may be etched using PEC etching or an etching solution containing KOH and NaOH Thereby forming the roughness 120R. The roughness 120R may be formed so as to include protrusions and / or depressions having a size of 탆 to nm scale formed on the surface of the first conductivity type semiconductor layer 121. By forming the roughness on the surface of the light emitting structure 120, the extraction efficiency of the light emitting element can be improved.

The light emitting structure 120 may further include a growth substrate (not shown) positioned under the first conductive type semiconductor layer 121. The growth substrate is not limited as long as it can grow the light emitting structure 120. For example, the growth substrate may be a sapphire substrate, a silicon carbide substrate, a silicon substrate, a gallium nitride substrate, an aluminum nitride substrate, or the like. Such a growth substrate can be separated and removed from the light emitting structure 120 using a known technique.

The second contact electrode 140 is located on the second conductive type semiconductor layer 125. The second contact electrode 140 may at least partially cover the upper surface of the second conductivity type semiconductor layer 125 and may make an ohmic contact with the second conductivity type semiconductor layer 125. The second contact electrode 140 may be disposed to cover the upper surface of the second conductive type semiconductor layer 125 as a whole. That is, the second conductive semiconductor layer 125 may be formed to cover the upper surface of the second conductive type semiconductor layer 125 as a single body in a region other than a position where the hole 120h of the light emitting structure 120 is formed. Accordingly, current can be uniformly supplied to the entire light emitting structure 120, and the current dispersion efficiency can be improved.

However, the present invention is not limited thereto, and the second contact electrodes 140 may not be integrally formed, but a plurality of unit reflection electrode layers spaced from each other may be disposed on the upper surface of the second conductivity type semiconductor layer 125 have. In this case, the unit reflection electrode layers may be electrically connected to each other through predetermined connection portions.

The second contact electrode 140 may include a material that can be in ohmic contact with the second conductive semiconductor layer 125 and may include, for example, a metal material and / or a conductive oxide.

When the second contact electrode 140 includes a metal material, the second contact electrode 140 may include a reflective layer and a cover layer covering the reflective layer. As described above, the second contact electrode 140 can perform the function of reflecting light in addition to ohmic contact with the second conductive type semiconductor layer 125. Accordingly, the reflective layer may include a metal having high reflectivity and capable of forming an ohmic contact with the second conductive semiconductor layer 125. For example, the reflective layer may include at least one of Ni, Pt, Pd, Rh, W, Ti, Al, Mg, Ag and Au. Also, the reflective layer may comprise a single layer or multiple layers.

The cover layer may prevent mutual diffusion between the reflective layer and other materials, and may prevent external substances from diffusing to the reflective layer and damaging the reflective layer. Accordingly, the cover layer may be formed to cover the bottom surface and the side surface of the reflective layer. The cover layer may be electrically connected to the second conductivity type semiconductor layer 125 together with the reflective layer so as to serve as an electrode together with the reflective layer. The cover layer may comprise, for example, Au, Ni, Ti, Cr, etc., and may comprise a single layer or multiple layers.

On the other hand, when the second contact electrode 140 includes a conductive oxide, the conductive oxide may be ITO, ZnO, AZO, IZO, or the like. When the second contact electrode 140 includes a conductive oxide, the upper surface of the second conductive type semiconductor layer 125 can cover a wider region than the case where the second contact electrode 140 includes a metal. That is, the distance from the upper rim of the hole 120h to the second contact electrode 140 may be relatively shorter when the second contact electrode 140 is formed of a conductive oxide. In this case, the shortest distance from the portion where the second contact electrode 140 and the second conductivity type semiconductor layer 125 are in contact to the portion where the first contact electrode 130 and the first conductivity type semiconductor layer 121 are in contact with each other the method can be relatively shorter, there can be reduced the forward voltage (V _f) of the light emitting element (100a).

The first and second insulating portions 151 and 153 may partly cover the first and second contact electrodes 130 and 140. Hereinafter, the first insulating portion 151 will be described first, and the contents related to the second insulating portion 153 will be described later.

The first insulating portion 151 may partly cover the upper surface of the light emitting structure 120 and the second contact electrode 140. The first insulating layer 151 covers the side surfaces of the plurality of holes 120h and may partially expose the first conductivity type semiconductor layer 121 exposed in the hole 120h.

Further, the first insulating portion 151 may further cover at least a part of the side surface of the light emitting structure 120. The extent to which the first insulating portion 151 covers the side surface of the light emitting structure 120 may vary depending on whether chip unit isolation is performed during the manufacturing process of the light emitting device. That is, as in the present embodiment, the first insulating portion 151 may be formed to cover only the upper surface of the light emitting structure 120, and after the wafer is individualized in the manufacturing process of the light emitting device 100a, In the case of forming the portion 151, the first insulating portion 151 may be covered up to the side surface of the light emitting structure 120.

The first insulating portion 151 may include a first opening portion located at a portion corresponding to the plurality of holes 120h and a second opening portion exposing a portion of the second contact electrode 140. [ The first conductive semiconductor layer 121 may be partially exposed through the first opening and the holes 120h and the second contact electrode 140 may be partially exposed through the second opening.

At this time, the first openings and the second openings may be arranged to have a certain pattern. For example, as shown in FIG. 1, the second openings may be disposed adjacent to one side of the light emitting device 100a, and the first openings may be regularly arranged in a region where the second openings are not disposed .

The first insulating portion 151 may include an insulating material, for example, SiO ₂ , SiN _x , MgF _2, or the like. Further, the first insulating portion 151 may include multiple layers, and may include a distributed Bragg reflector in which materials having different refractive indices are alternately stacked. In particular, when the second contact electrode 140 includes a conductive oxide, the first insulating portion 151 may include a distributed Bragg reflector to improve the luminous efficiency of the light emitting device 100a.

The first contact electrode 130 may partly cover the light emitting structure 120 and may make ohmic contact with the first conductive semiconductor layer 121 through the plurality of holes 120h and the first openings. Accordingly, the first contact electrode 130 may include the ohmic contact region 131 that is in direct contact with the first conductivity type semiconductor layer 121 and is in ohmic contact therewith. When the light emitting structure 120h includes a plurality of holes 120h, the ohmic contact regions 131 may also be formed in a plurality of numbers corresponding to the number of the holes 120h.

The first contact electrode 130 may be formed to cover the entirety of the first insulating member 151 except for a part of the first insulating member 151. The first contact electrode 130 may be formed to cover the side surface of the light emitting structure 120. When the first contact electrode 130 is also formed on the side surface of the light emitting structure 120, the light emitted to the side from the active layer 123 is reflected upward to increase the ratio of light emitted to the upper surface of the light emitting device 200e . The first contact electrode 130 is not formed in a region corresponding to the second opening portion of the first insulating portion 151 but isolated from the second contact electrode 140.

The first contact electrode 130 is formed so as to cover the entire upper surface of the light emitting structure 120 except for a part of the region, thereby further improving the current dispersion efficiency. In addition, since the first contact electrode 130 can cover a portion not covered by the second contact electrode 140, the light can be more effectively reflected and the light emitting efficiency of the light emitting device 100a can be improved.

The first contact electrode 130 may serve to reflect the light as well as the ohmic contact with the first conductive semiconductor layer 121. Accordingly, the first contact electrode 130 may be a single layer or a multilayer, and may include a highly reflective metal layer such as an Al layer. The highly reflective metal layer may be formed on an adhesive layer such as Ti, Cr or Ni. The first contact electrode 130 may include at least one of Ni, Pt, Pd, Rh, W, Ti, Al, Mg, Ag and Au.

The first contact electrode 130 is in ohmic contact with the first conductive semiconductor layer 121 through the holes 120h so that the active layer 123 is formed to form an electrode connected to the first conductive semiconductor layer 121. [ The area to be removed is the same as the area corresponding to the plurality of holes 120h. Therefore, the region for the ohmic contact between the first conductive type semiconductor layer 121 and the metal layer can be minimized, and a light emitting device having a relatively large area ratio of the light emitting region to the horizontal area of the entire light emitting structure can be provided.

The second insulating portion 153 may partly cover the first contact electrode 130. The second insulating portion 153 includes a third opening 153a for partially exposing the first contact electrode 130 and a fourth opening 153b for partially exposing the second contact electrode 140 can do. At this time, the fourth opening 153b may be formed at a position corresponding to the second opening.

One or more of the third and fourth openings 153a and 153b may be formed. 1 (b), the fourth opening 153b may be positioned adjacent to one side edge of the light emitting device 100a, and the third opening 153a may be located at least a part of the plurality And may be formed to expose a position where the hole 120h is formed. Further, the third opening 153a may be formed to expose a position where all the holes 120h are formed. Accordingly, the ohmic contact regions 131 can be exposed through the third opening 153a.

The second insulating portion 153 may include an insulating material, for example, SiO ₂ , SiN _x , and MgF ₂ . Further, the second insulating portion 153 may include multiple layers, and may include a distributed Bragg reflector in which materials having different refractive indices are alternately stacked.

The first electrode 161 and the second electrode 163 may be positioned on the light emitting structure 120 and the first electrode 161 and the second electrode 163 may be positioned on the first contact electrode 130 and the second electrode 163, 2 contact electrode 140. [0033] In particular, the first electrode 161 and the second electrode 163 may be in direct contact with and electrically connected to the first and second contact electrodes 130 and 140, respectively.

Also, at least some of the holes 120h may be located under the first electrode 161, and further, all of the holes 120h may be located under the first electrode 161. [ Accordingly, the ohmic contact region 131 of the first contact electrode 130 can be interposed between the first electrode 161 and the first conductive semiconductor layer 121, and all of the ohmic contact regions 131, May be in direct contact with the first electrode 161.

On the other hand, the hole 120h may not be located under the second electrode 163. That is, the portion where the first contact electrode 130 and the first conductivity type semiconductor layer 121 are in ohmic contact may not be located below the region where the second electrode 163 is formed. Therefore, as shown in FIG. 1, the holes 120h of the light emitting structure 120 may be formed only in the remaining portion except the region adjacent to one side of the light emitting device 100a.

The first electrode 161 and the second electrode 163 may have different volumes and the volume of the first electrode 161 may be larger than the volume of the second electrode 163. [ In addition, the first electrode 161 and the second electrode 163 may have a thickness of about 70 to 80 탆 or more, and may be formed to have substantially the same thickness. Therefore, the horizontal cross-sectional area of the first electrode 161 may be larger than the horizontal cross-sectional area of the second electrode 163. For example, the horizontal cross-sectional area of the first electrode 161 may be larger than that of the first and second electrodes 161 , 163), which is equal to or greater than 0.8 times the value obtained by adding the horizontal cross-sectional areas of the first, second,

That is, the light emitting device 100a includes a first electrode 161 having a horizontal cross-sectional area that is relatively larger than a horizontal cross-sectional area of the second electrode 163. When the first conductivity type semiconductor layer 121 is an N-type semiconductor layer, the first electrode 161 may also function as an N-type electrode. As described above, when the light emitting element 100a is driven, And concentrated in the region where the first electrode 161 is located. Therefore, by forming the horizontal cross-sectional area of the first electrode 161 to be much larger than the horizontal cross-sectional area of the second electrode 163 as in this embodiment, it is possible to uniformly emit light in the entire light emitting region of the light emitting element 100a, And the heat dissipation efficiency of the light emitting device 100a can be improved by effectively emitting heat through the first electrode 161. [

In addition, the first electrode 161 may directly contact the first contact electrode 130, and may also directly contact the ohmic contact regions 131 of the first contact electrode 130. At this time, the ohmic contact regions 131 correspond to the positions of the plurality of holes 120h, and the holes 120h are generally arranged in the light emitting structure 120 in a substantially regular manner. Accordingly, the electric current can be uniformly dispersed in the horizontal direction to improve the electrical characteristics of the light emitting device 100a, and the heat generated from the light emitting structure 120 can be transmitted through the ohmic contact region 131 and the first electrode 161 It can be effectively released to the outside.

In addition, the portion where the first contact electrode 130 and the first conductive type semiconductor layer 121 are in ohmic contact is not located below the region where the second electrode 163 is formed, so that the first conductive type semiconductor layer 121 and the first contact electrode 130 can be discharged through the first electrode 161. Therefore, the heat emission efficiency of the light emitting element 100a can be further improved.

As described above, according to the present invention, the luminous efficiency and heat radiation efficiency of the light emitting device 100a can be improved, and reliability and life can be improved.

Meanwhile, the first electrode 161 and the second electrode 163 may include metal particles and a non-metallic material interposed between the metal particles. In addition, each of the first and second electrodes 161 and 163 may include a metal particle sintered body including the metal particles and a non-metallic material. In the metal particle sintered body, the metal particles may be sintered to form a plurality of grains, and at least a part of the region between the metal particles may include a non-metallic material. Such a non-metallic material can serve as a buffer for relieving the stress that may occur in the first electrode 161 and the second electrode 163. Accordingly, the mechanical stability of the first electrode 161 and the second electrode 163 is improved, and the stress that can be applied to the light emitting structure 120 from the electrode 160 can be reduced.

Metal particles of the first electrode 161 and the second electrode 163 may be included in a ratio of 80 to 98 wt% of the mass of the first and second electrodes 161 and 163, respectively. Since the first electrode 161 and the second electrode 163 include the metal particles in the above-described ratio, they can have excellent thermal conductivity and electrical conductivity, effectively buffering the stress that may occur in the electrodes 161 and 163 The mechanical stability of the electrodes 161 and 163 can be improved.

The metal particles are not limited as long as they are thermally conductive and electrically conductive, and may include, for example, Cu, Au, Ag, Pt, and the like. The non-metallic material may be one derived from a material to be sintered to form an electrode, and may be, for example, a polymer material comprising C.

Although the metal particles are described as being included in the first and second electrodes 161 and 163 in the form of sintered metal particles in the above embodiments, the present invention is not limited thereto. Alternatively, the first electrode 161 and the second electrode 163 may be formed through deposition and / or plating of metal. In this case, the first electrode 161 and the second electrode 163 may be multi-layered.

In this embodiment, the first electrode 161 and the second electrode 163 may have sides that are substantially perpendicular to the upper surface of the second insulating portion 153. However, the present invention is not limited thereto. As shown in FIG. 3, each of the first electrode 261 and the second electrode 263 may have an inclined side surface.

3 is a cross-sectional view illustrating a light emitting device 100b according to another embodiment of the present invention. Compared with the light emitting device 100a of FIGS. 1 and 2, the electrodes 261 and 263 have inclined side surfaces .

Referring to FIG. 3, each of the first electrode 261 and the second electrode 263 may include an inclined side surface. In particular, as shown in FIG. 3, each of the first electrode 261 and the second electrode 263 may include a sloped side where the slope of the tangential line TL with respect to the side surface of the vertical section changes. Specifically, the inclination of the tangential line TL with respect to the side surface of the vertical section of each of the first electrode 261 and the second electrode 263 increases in the direction from the lower portion to the upper portion, can do. Accordingly, the inclined side surfaces of each of the first electrode 261 and the second electrode 263 may include a region where the inclination of the tangent line TL increases and a region where the inclination of the tangent line TL is decreased.

Each of the first electrode 261 and the second electrode 263 includes an inclined side surface on which a tilt of the tangential line TL with respect to the side surface of the vertical section is changed so that the first electrode 261 and the second electrode 263 ) May vary in the vertical direction. For example, as shown, the horizontal cross-sectional area of each of the first electrode 261 and the second electrode 263 may be reduced in a direction away from the top surface of the light emitting structure 120.

Accordingly, each of the first electrode 261 and the second electrode 263 may be shaped to have a side surface of the above-described shape, and may be formed in a shape similar to a truncated arcuate shape, for example. The first electrode 261 and the second electrode 263 include inclined side surfaces in which the slope of the tangential line TL with respect to the side surface of the vertical section is changed so that the first and second electrodes 261 and 263, 3 mechanical stability at the interface of the insulating portion 170 can be improved.

1 and 2, the first electrode 161 and the second electrode 163 may be in direct contact with the first contact electrode 130 and the second contact electrode 140, respectively. That is, the first electrode 161 and the second electrode 163 may be formed so as to directly contact the first and second contact electrodes, respectively. If a plating method is used, a seed layer or a solder A separate additional configuration, such as the necessary wetting, may be omitted. However, the present invention is not limited thereto.

Meanwhile, the shortest distance between the first electrode 161 and the second electrode 163 may be about 10 to 80 탆. Accordingly, it is possible to prevent the forward voltage V _f of the light emitting device 100 a from increasing due to the distance between the electrodes, and also to prevent the horizontal cross-sectional area of the electrodes 161 and 163 from increasing And the efficiency of heat emission of the light emitting device 100a can be improved.

The third insulating portion 170 may be formed on the light emitting structure 120 so as to at least partially cover the sides of the electrodes 161 and 163. The first electrode 161 and the second electrode 163 may be exposed on the upper surface of the third insulating portion 170.

The third insulating portion 170 is electrically insulative and covers the sides of the first electrode 161 and the second electrode 163, effectively insulating them from each other. At the same time, the third insulating portion 170 may serve to support the first electrode 161 and the second electrode 163. The upper surface of the third insulating portion 170 may be formed to be substantially flush with the upper surfaces of the first electrode 161 and the second electrode 163.

The third insulating portion 170 may include an insulating polymer and / or an insulating ceramic, and may include materials such as EMC (Epoxy Molding Compound) and Si resin. In addition, the third insulating portion 170 may include light reflective and light scattering particles such as TiO ₂ particles.

In addition, unlike the illustrated example, the third insulating portion 170 may cover the side surface of the light emitting structure 120. In this case, the light emitting angle of the light emitted from the light emitting structure 120 may vary. For example, when the third insulating portion 170 further covers at least a part of the side surface of the light emitting structure 120, a part of the light emitted to the side surface of the light emitting structure 120 is reflected to the bottom surface of the light emitting structure 120 . Thus, by controlling the area where the third insulating portion 170 is disposed, the light emitting angle of the light emitting element 100a can be adjusted.

The light emitting device 100a may further include a first pad electrode (not shown) and a second pad electrode (not shown). The first and second pad electrodes may be positioned on the third insulating portion 170 and may be in electrical contact with the first and second electrodes 161 and 163, respectively.

When the light emitting device 100a is applied to a module or the like, the first and second pad electrodes allow the light emitting device 100a to be more stably mounted on a separate additional substrate or the like. For example, when the first and second electrodes 161 and 163 include a sintered body of Cu or Ag particles, the first and second electrodes 161 and 163 have poor wettability to solder and the like. Accordingly, by disposing the first and second pad electrodes on the third insulating portion 170, the light emitting device 100a can be stably mounted.

The first and second electrode pads may include a conductive material such as a metal and may be formed of a metal such as Ni, Pt, Pd, Rh, W, Ti, Al, Ag, Sn, Cu, Ag, , Sb, Mg, Pb, and the like. In addition, each of the first and second electrode pads may be formed of a single layer or multiple layers.

The wavelength converting portion may be positioned on the lower surface of the light emitting structure 120.

The wavelength converting unit converts the wavelength of the light emitted from the light emitting structure 120 so that the light emitting device can emit light of a desired wavelength band. The wavelength converting portion may include a phosphor and a support on which the phosphor is supported. The phosphor may include various phosphors commonly known to those of ordinary skill in the art, and may include at least one of a garnet fluorescent material, an aluminate fluorescent material, a sulfide fluorescent material, an oxynitride fluorescent material, a nitride fluorescent material, a fluoride fluorescent material, and a silicate fluorescent material. The carrier may also be a material well known to a person skilled in the art, for example, an epoxy resin, a polymer resin such as an acrylic resin, or a silicone resin. In addition, the wavelength converter may be composed of a single layer or multiple layers.

The wavelength converting portion may cover the lower surface of the light emitting structure 120 and may cover the side surface of the light emitting structure 120 and further cover the side surface of the third insulating portion 170.

In the present embodiment, the light emitting device 100a having the light emitting structure 120 including the plurality of holes 120h has been described, but the present invention is not limited thereto. The mutual engagement / disposition of the light emitting structure 120, the first and second contact electrodes 130 and 140, and the first and second insulating portions 151 and 153 can be variously modified. The light emitting element is also included in the scope of the present invention.

4 and 5 are a plan view and a cross-sectional view for illustrating a light emitting device according to another embodiment of the present invention.

The light emitting device 100c according to the embodiment of FIGS. 4 and 5 is substantially similar to the light emitting device 100a of FIGS. 1 and 2, but differs in the third opening 153a, There is a difference in that the wiring layers 181 and 183 are further included. The light emitting device 100c of the present embodiment will be mainly described below, and detailed description of the same configuration will be omitted.

4A is a plan view of the light emitting device 100c, FIG. 4B is a plan view for explaining the position of the hole 120h and the positions of the third opening 153a and the fourth opening 153b, 5 is a cross-sectional view showing a cross section of a region corresponding to the BB line in Figs. 4 (a) and 4 (b).

4 and 5, the light emitting device 100c includes a light emitting structure 120 including a first conductive semiconductor layer 121, an active layer 123, and a second conductive semiconductor layer 125, The second contact electrode 140, the first and second insulating portions 151 and 153, the first electrode 161, the second electrode 163, the third insulating portion 170, 1 wiring layer 181 and a second wiring layer 183. Furthermore, the light emitting device 100c may further include first and second pad electrodes (not shown), a growth substrate (not shown), and a wavelength conversion unit (not shown).

The third opening 153a of the second insulating portion 153 covers the first contact electrode 130 and may partially expose the first contact electrode 130. [ At this time, the third opening 153a may be formed only on a region where some of the holes 120h are located. Accordingly, only a part of the ohmic contact regions 131 may be exposed in the third opening 153a, and the remaining ohmic contact regions 131 may be covered in the second insulating portion 153. [

The third opening 153a may be positioned opposite to the position of the fourth opening 153b and specifically when the fourth opening 153b is located adjacent to one side of the light emitting device 100c, The opening 153a may be positioned adjacent to the other side opposite to the one side surface.

The light emitting device 100c of the present embodiment may further include a first wiring layer 181 and a second wiring layer 183 located under the first electrode 161 and the second electrode 163, respectively.

The first wiring layer 181 can electrically connect the first contact electrode 130 and the first electrode 161 and the second wiring layer 183 can electrically connect the second contact electrode 140 and the second electrode 163 Can be electrically connected.

Further, when the first electrode 161 and the second electrode 163 are formed through a deposition or plating method, the first and second wiring layers 181 and 183 may serve as a seed layer. In addition, even when the first electrode 161 and the second electrode 163 are formed through the sintering process, the first electrode 161 and the second electrode 163 can be stably formed as a wetting layer Can help. Therefore, the first and second electrodes 161 and 163 can be stably bonded to the light emitting structure 120 by the first and second wiring layers 181 and 183.

Accordingly, the wiring layers 181 and 183 may include a metal material so as to serve as a seed layer or a wetting layer. For example, the wiring layers 181 and 183 may include Cu, Au, Ag, Ni, Pt, and the like.

The wiring layers 181 and 183 are not limited to the present embodiment and can be applied to other embodiments.

6 and 7 are a plan view and a sectional view for explaining a light emitting device according to another embodiment of the present invention.

The light emitting device 100d according to the embodiment of FIGS. 6 and 7 is substantially similar to the light emitting device 100a of FIGS. 1 and 2 but includes a connection layer 210 and pad electrodes 231 and 233 There is a difference in point. The light emitting device 100d of the present embodiment will be mainly described below, and detailed description of the same configuration will be omitted.

6A is a plan view of the light emitting device 100d, FIG. 6B is a plan view for explaining the position of the hole 120h and the positions of the third opening 153a and the fourth opening 153b, 7 is a cross-sectional view showing a cross section of a region corresponding to the CC line in Figs. 6 (a) and 6 (b).

6 and 7, the light emitting device 100d includes a light emitting structure 120 including a first conductivity type semiconductor layer 121, an active layer 123, and a second conductivity type semiconductor layer 125, The second contact electrode 140, the first and second insulating members 151 and 153, the first electrode 161, the second electrode 163, the third insulating member 170, the connection electrode 130, the second contact electrode 140, A layer 210, and pad electrodes 231 and 233. Furthermore, the light emitting device 100d may further include a growth substrate (not shown) and a wavelength conversion unit (not shown).

The connection layer 210 may be disposed on the first electrode 161, the second electrode 163, and the third insulation portion 170.

The connection layer 210 may include a first connection layer 211, a second connection layer 213, and an insulating material layer 215. The first connection layer 211 and the second connection layer 213 are located on the first electrode 161 and the second electrode 163, respectively, and may be electrically connected. The insulating material layer 215 insulates the first connection layer 211 and the second connection layer 213 from each other. The upper surfaces of the insulating material layer 215, the first connecting layer 211, and the second connecting layer 213 may be formed in parallel so as to be substantially flush with each other.

The first connection layer 211 and the second connection layer 213 may include a metal having electrical conductivity, a conductive oxide, a conductive nitride, or the like. In particular, Au, Ag, Cu, Ni, Pt As shown in FIG. The insulating material layer 215 may include SiO ₂ , SiN _x , or an insulating polymer.

The first pad electrode 231 and the second pad electrode 233 are located on the connection layer 210 and may be electrically connected to the electrodes 161 and 163 by the connection layer 210. Specifically, the first and second pad electrodes 231 and 233 may be electrically connected to the first and second electrodes 161 and 163 by a first connection layer 211 and a second connection layer 213, respectively. have.

The first pad electrode 231 and the second pad electrode 233 allow the light emitting device 100d to be more reliably mounted on a separate additional substrate or the like. For example, when the first and second electrodes 161 and 163 include a sintered body of Cu or Ag particles, the first and second electrodes 161 and 163 have poor wettability to solder and the like. Therefore, by further disposing the first and second pad electrodes on the third insulating portion 170, the light emitting element 100d can be stably mounted.

Further, the horizontal cross-sectional area of the first pad electrode 231 may be smaller than the horizontal cross-sectional area of the first electrode 161, and the horizontal cross-sectional area of the second pad electrode 233 may be smaller than the horizontal cross- . In particular, the horizontal cross-sectional area of the first pad electrode 231 and the horizontal cross-sectional area of the second pad electrode 233 may be substantially the same.

If the horizontal cross-sectional area of the first electrode 161 is much larger than the horizontal cross-sectional area of the second electrode 163, a failure may occur when the light emitting device is mounted on a secondary substrate such as a PCB. Further, in order to stably mount the light emitting element on the secondary substrate, the conductive pattern of the portion where the light emitting element is mounted on the secondary substrate must be changed. However, since the light emitting device 100d of the present embodiment further includes the first pad electrode 231 and the second pad electrode 233, the electrodes on the surface on which the light emitting device 100d is mounted on the secondary substrate, (100d). ≪ / RTI > Therefore, the light emitting device 100d of the present invention can be applied to various applications through a general light emitting device mounting method without adding or changing processes, and the defect rate in the mounting process can also be reduced.

The first and second pad electrodes 231 and 233 may include a conductive material such as a metal such as Ni, Pt, Pd, Rh, W, Ti, Al, Ag, Sn, Bi, In, Zn, Sb, Mg, Pb and the like.

On the other hand, the insulating material layer 215 may have a thickness of about 10 mu m or less, so that heat emitted from the first and second electrodes 161 and 163 by the insulating material layer 215 is emitted to the outside It is possible to prevent deterioration of the efficiency of operation.

8 and 9 are plan views and cross-sectional views for explaining a light emitting device according to another embodiment of the present invention.

The light emitting device 100e according to the embodiment of FIGS. 8 and 9 is substantially similar to the light emitting device 100e of FIGS. 6 and 7, but includes a plurality of second electrodes 163. The light emitting device 100e of the present embodiment will be mainly described below, and detailed description of the same configuration will be omitted.

8A is a plan view of the light emitting device 100e, FIG. 8B is a plan view for explaining the position of the hole 120h and the positions of the third opening 153a and the fourth opening 153b, 9 is a cross-sectional view showing a cross section of a region corresponding to the DD line in Figs. 7A and 7B.

8 and 9, the light emitting device 100e includes a light emitting structure 120 including a first conductivity type semiconductor layer 121, an active layer 123, and a second conductivity type semiconductor layer 125, The second contact electrode 140, the first and second insulating members 151 and 153, the first electrode 161, the second electrode 163, the third insulating member 170, the connection electrode 130, the second contact electrode 140, A layer 210, and pad electrodes 231 and 233. Furthermore, the light emitting device 100e may further include a growth substrate (not shown) and a wavelength conversion unit (not shown).

The second electrodes 163 may be formed in plural numbers. 6 and 7, the number of holes 120h can be increased, the area of the third opening 153a can be larger, and the area of the first electrode 161 The cross-sectional area can also be increased. The second electrodes 163 may be spaced apart from one another, and some holes 120h may be disposed between the second electrodes 163.

According to the present embodiment, the horizontal cross-sectional area of the first electrode 161 is further increased, the heat emission efficiency of the light emitting device 100e can be further increased, and the light emission characteristic can be also improved.

Meanwhile, the pad electrodes 231 and 233 may be omitted.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the following claims.

Claims (20)

A light emitting structure including a first conductive semiconductor layer, a second conductive semiconductor layer, and an active layer disposed between the first conductive semiconductor layer and the second conductive semiconductor layer;
A first contact electrode and a second contact electrode located on the light emitting structure and ohmically contacting the first and second conductive type semiconductor layers, respectively;
First and second insulating portions partially covering the first contact electrode and the second contact electrode;
A first electrode and a second electrode that are disposed on the light emitting structure and are electrically connected to the first and second contact electrodes, respectively;
A third insulating portion covering the side surfaces of the first electrode and the second electrode;
A connection layer located on the first electrode, the second electrode and the third insulation portion; And
A first pad electrode and a second pad electrode positioned on the connection layer,
The first pad electrode and the second pad electrode are electrically connected to the first electrode and the second electrode through the connection layer,
Wherein a horizontal area of the first pad electrode is smaller than a horizontal area of the first electrode and a horizontal area of the second pad electrode is larger than a horizontal area of the second electrode. The method according to claim 1,
Wherein the first electrode is located on a portion where the first contact electrode and the first conductivity type semiconductor layer are in ohmic contact with each other. The method of claim 2,
And a portion where the ohmic contact between the first contact electrode and the first conductivity type semiconductor layer is not located below the second electrode. The method of claim 2,
Wherein the first contact electrode includes a plurality of ohmic contact regions that are in ohmic contact with the first conductivity type semiconductor layer,
Wherein the first electrode is in contact with all of the plurality of ohmic contact regions of the first contact electrode. The method of claim 2,
Wherein the first contact electrode includes a plurality of ohmic contact regions that are in ohmic contact with the first conductivity type semiconductor layer,
Wherein only a part of the plurality of ohmic contact regions is in contact with the first electrode. The method of claim 5,
A first wiring layer located under the first electrode; And
And a second wiring layer located under the second electrode,
Wherein a part of the first wiring layer is in contact with the first contact electrode and a part of the second wiring layer is in contact with the second contact electrode. The method of claim 6,
And a part of the second insulating portion is located between the first wiring layer and the first contact electrode. The method according to claim 1,
Wherein a horizontal cross-sectional area of the first electrode is 0.8 times or more and less than 1 times the sum of horizontal cross-sectional areas of the first electrode and the second electrode. The method according to claim 1,
Wherein a horizontal area of the first pad electrode is equal to a horizontal area of the second pad electrode. The method according to claim 1,
The connection layer may be formed,
An insulating material layer;
A first connection layer electrically connecting the first electrode and the first pad electrode, the first connection layer penetrating the insulating material layer; And
And a second connection layer electrically connecting the second electrode to the second pad electrode and penetrating the insulating material layer. The method according to claim 1,
And the second electrodes are electrically connected to the second pad electrode. The method of claim 11,
Wherein the first contact electrode includes a plurality of ohmic contact regions that are in ohmic contact with the first conductivity type semiconductor layer,
And a portion of the plurality of ohmic contact regions is disposed between the second electrodes. The method according to claim 1,
Wherein each of the first and second electrodes comprises metal particles and a non-metallic material interposed between the metal particles. 14. The method of claim 13,
Wherein the metal particles and the non-metallic material are formed in the form of a metal particle sintered body. 15. The method of claim 14,
Wherein each of the first electrode and the second electrode includes an inclined side surface and the inclined side surface includes a side surface where a tangential slope of a vertical section of each of the first electrode and the second electrode varies. 14. The method of claim 13,
Wherein each of the first electrode and the second electrode comprises 80 to 98 wt% of metal particles. The method according to claim 1,
Wherein the light emitting structure further includes a region in which the active layer and the second conductivity type semiconductor layer are partially removed to partially expose the first conductivity type semiconductor layer,
Wherein the first contact electrode is in ohmic contact with the first conductivity type semiconductor layer through a region in which the first conductivity type semiconductor layer is partially exposed. 18. The method of claim 17,
Wherein a region in which the first conductivity type semiconductor layer is partially exposed is formed in a plurality of holes. 19. The method of claim 18,
The second contact electrode is located on the second conductive type semiconductor layer,
The first insulating portion may include a first opening portion and a second opening portion that cover the second contact electrode and the light emitting structure and expose a part of a region where the first conductivity type semiconductor layer is exposed and a part of the second contact electrode, and,
Wherein the first contact electrode at least partially covers the first insulating portion and contacts the first conductive type semiconductor layer through the first opening,
The second insulating portion may include a third opening partially covering the first contact electrode and partially exposing the first contact electrode and a second opening exposing a portion of the second contact electrode, And a fourth opening. The method of claim 19,
Wherein the first electrode is in contact with the first contact electrode through the third opening and the second electrode is in contact with the second contact electrode through the fourth opening,
And the plurality of holes are all located below the region of the third opening.

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