KR102550006B1 - Light emitting diode - Google Patents

Abstract

A light emitting diode according to an embodiment includes a substrate, a lower semiconductor layer disposed on the substrate, a first upper semiconductor layer disposed on a region of the lower semiconductor layer, and disposed between the lower semiconductor layer and the first upper semiconductor layer. A light emitting cell including an active layer, a first current spreading unit including a second upper semiconductor layer disposed on another region of the lower semiconductor layer and an active layer disposed between the lower semiconductor layer and the second upper semiconductor layer, the light emitting cell and the second upper semiconductor layer. 1 disposed between the current distributing unit and including a third upper semiconductor layer disposed on the lower semiconductor layer and an active layer disposed between the lower semiconductor layer and the third upper semiconductor layer, the second current distributing unit, the first upper semiconductor layer and a first electrode electrically connected to the lower semiconductor layer, and a second electrode electrically connected to the lower semiconductor layer, wherein the second electrode extends to cover at least a portion of the second current distributing unit, and the second current distributing unit includes a plurality of dispersions. In addition, a plurality of dispersions have the same shape and are arranged at regular intervals.

Description

Light Emitting Diode {LIGHT EMITTING DIODE}

The present invention relates to a light emitting diode. More specifically, the present invention relates to a light emitting diode including a current spreading unit.

A light emitting diode is an inorganic semiconductor that emits light generated by recombination of electrons and holes, and has recently been used in various fields such as displays, automobile lamps, and general lighting.

The light emitting device may be classified into a horizontal type light emitting device, a vertical type light emitting device, or a flip-chip type light emitting device, etc. according to a position where an electrode is disposed or a method in which the electrode is connected to an external lead.

The horizontal type light emitting device is most widely used because of its relatively simple manufacturing method. In such a horizontal type light emitting device, the growth substrate is formed as it is at the bottom. As a growth substrate for the light emitting device, a sapphire substrate is most widely used. However, since the sapphire substrate has low thermal conductivity, it is difficult to dissipate heat from the light emitting device. Accordingly, the junction temperature of the light emitting device is increased and the internal quantum efficiency is lowered.

In order to solve the problems of the horizontal type light emitting device described above, a vertical type light emitting device or a flip chip type light emitting device is being developed.

1 shows a conventional flip-chip type light emitting diode. The conventional light emitting diode 100 according to FIG. 1 includes a growth substrate 11, a first conductivity type semiconductor layer 13, an active layer 15, a second conductivity type semiconductor layer 17, a first electrode 19, It may include a second electrode 20 , a first pad 30a , a second pad 30b and an insulating layer 31 . A light emitting cell may be formed through the first conductivity type semiconductor layer 13 , the active layer 15 and the second conductivity type semiconductor layer 17 . The first conductivity type semiconductor layer 13 and the second conductivity type semiconductor layer 17 may be electrically connected to the first pad 30a and the second pad 30b, respectively.

The light emitting diode according to the prior art has a problem in that a current drift occurs when the electrodes 19 and 20 are horizontally disposed during high current driving. Accordingly, not only variation in light emission intensity occurs, but also a problem in that light efficiency is reduced. Therefore, development of a light emitting diode capable of spreading the current by distributing the current in the light emitting diode is required.

An object to be solved by the present invention is to provide a light emitting diode in which light efficiency is improved and variation in emission intensity according to regions in an active layer is eliminated.

Another problem to be solved by the present invention is to provide a light emitting diode that includes a structure capable of improving current diffusion in a light emitting diode and has improved light extraction efficiency by using light reflection through the structure.

A light emitting diode according to an embodiment of the present invention includes a substrate; a lower semiconductor layer disposed on the substrate; a light emitting cell including a first upper semiconductor layer disposed on one region of the lower semiconductor layer and an active layer disposed between the lower semiconductor layer and the first upper semiconductor layer; a second current spreading unit including a third upper semiconductor layer disposed on another region of the lower semiconductor layer and an active layer disposed between the lower semiconductor layer and the third upper semiconductor layer; a first electrode disposed on the light emitting cell and electrically connected to the first upper semiconductor layer; and a second electrode disposed spaced apart from the light emitting cell and electrically connected to the lower semiconductor layer, wherein the second electrode extends to cover at least a portion of the second current distributing portion and to cover at least a portion of the light emitting cell. However, contact resistance between the second electrode and the third upper semiconductor layer may be greater than that between the second electrode and the lower semiconductor layer.

A first current distributing part disposed in another area of the lower semiconductor layer opposite to one area of the lower semiconductor layer with the other area of the lower semiconductor layer as a center, wherein the first current distributing part is disposed in the lower semiconductor layer. A second upper semiconductor layer disposed on another region of the layer and an active layer disposed between the lower semiconductor layer and the second upper semiconductor layer may be included.

A contact resistance between the second electrode and the second upper semiconductor layer may be greater than a contact resistance between the second electrode and the lower semiconductor layer.

The second electrode may be disposed on the first current spreading part.

The second current spreading part may be disposed adjacent to the first current spreading part rather than the light emitting cell.

The first current spreading part may have the same height as the light emitting cell.

A sum of upper surface areas of each of the first current spreading part and the second current spreading part may be 10 to 40% of an area of the second electrode.

The second current spreading unit may include a plurality of dispersion elements, and the dispersion elements may be spaced apart from each other at uniform intervals.

An insulating layer disposed on the first electrode and the second electrode and including a first open area exposing the first electrode and a second open area exposing the second electrode may be further included.

The insulating layer may include at least one of a silicon nitride layer and a silicon oxide layer.

The insulating layer may include a distributed Bragg reflector.

a first bump electrically connected to a first electrode through the first open area; and a second bump electrically connected to the second electrode through the second open area.

The first bump includes a first concave portion and a first convex portion at an upper portion, and the first bump includes a first region including a bottom surface of the first concave portion on an upper surface and a top surface of the first convex portion on an upper surface thereof. It may be formed of a second region, at least a portion of the first region may be disposed on the first open region, and at least a portion of the second region may be disposed on an insulating layer.

An area of a bottom surface of the first concave portion may be proportional to an area of the first electrode exposed through the first open area.

A depth of the first concave portion may be proportional to a thickness of an insulating layer disposed on the first electrode.

A sum of an area of a top surface of the first convex portion and an area of a bottom surface of the first concave portion may be greater than an area of the first electrode exposed through at least the first open area.

The first convex portion may surround the first concave portion.

A portion of an insulating layer may be disposed between the first electrode and the first bump and between the second electrode and the second bump.

At least a portion of a side surface of the insulating layer surrounding the first open area and a side surface of the first bump may be in contact with each other.

The second electrode may include a reflective layer that reflects light emitted from the active layer of the light emitting cell.

A light emitting diode according to the present invention includes a current dissipation unit serving as a current dissipation structure. Accordingly, current diffusion in the light emitting diode can be improved by inducing a current flow mainly on the electrode metal and simultaneously dispersing the current. Therefore, it is possible to improve the light efficiency of the light emitting diode and reduce the variation in light emission intensity. In addition, since the current spreading unit can be manufactured through a conventional manufacturing process without a separate additional process, manufacturing cost and time can be reduced.

1 is a schematic cross-sectional view for explaining a light emitting diode according to the prior art.
2 is a plan view and a cross-sectional view for explaining a light emitting diode according to an embodiment of the present invention.
3 is a plan view and a cross-sectional view for explaining a light emitting diode according to another embodiment of the present invention.
4 is a cross-sectional view for explaining a light emitting device according to an embodiment of the present invention.
5 is a perspective view for explaining a light emitting diode package according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments introduced below are provided as examples to sufficiently convey the spirit of the present invention to those skilled in the art. Accordingly, the present invention may be embodied in other forms without being limited to the embodiments described below. And, in the drawings, the width, length, thickness, etc. of components may be exaggerated for convenience. Also, when an element is described as being “on top of” or “on” another element, each part is “immediately on” or “directly on” the other element, as well as each element and other elements. It also includes the case where there is another component in between. Like reference numbers indicate like elements throughout the specification.

2 is a plan view and a cross-sectional view for explaining a light emitting diode according to an embodiment of the present invention.

FIG. 2(a) is a plan view of the light emitting diode, and FIG. 2(b) is a cross-sectional view taken along the line A-A of FIG. 2(a).

Referring to FIG. 2 , a light emitting diode according to an embodiment of the present invention includes a growth substrate 100 and a light emitting cell 110, and the light emitting cell 110 includes a lower semiconductor layer 115, an active layer 113 and A first upper semiconductor layer 111 is included. On the lower semiconductor layer 115 , a first current spreading unit 120 and a second current spreading unit 130 including portions of the lower semiconductor layer 115 are disposed. In addition, a second electrode 140 is disposed on the lower semiconductor layer 115 , and the second electrode 140 includes a second contact layer 141 and a second pad layer 143 . In addition, a second bump 170 is disposed on the second electrode 140 .

A first electrode 150 is disposed on the first upper semiconductor layer 111 , and the first electrode 150 includes a first contact layer 151 and a first pad layer 153 . A first bump 180 is disposed on the first electrode 150 . In addition, the insulating layer 160 is disposed on the entire surface of the light emitting diode except for the first and second open areas 150a and 140a for the arrangement of the first and second bumps 170 and 180 .

Referring back to FIG. 2 , the growth substrate 100 is a substrate having a hexagonal crystal structure and may be a growth substrate for growing a gallium nitride-based epitaxial layer, for example, a sapphire, silicon carbide, or gallium nitride substrate. The growth substrate 100 may include one surface, another surface opposite to the one surface, and a side surface connecting the one surface and the other surface. The one surface may be a surface on which semiconductor layers are grown, and the other surface is a surface through which light generated in the active layer 113 is emitted to the outside. The side surface of the growth substrate 100 may be a surface perpendicular to the one surface and the other surface, but may include an inclined surface. Before forming the lower semiconductor layer 115 on one surface of the growth substrate 100, a buffer layer (not shown) including AlN or GaN may be formed to reduce lattice mismatch with the heterogeneous substrate. In addition, the growth substrate 100 may have a rectangular shape as a whole, but the shape of the growth substrate 100 is not limited thereto.

Meanwhile, in this embodiment, the thickness of the growth substrate 100 may exceed 100 μm, and particularly may have a value within a range of 150 to 400 μm. As the thickness of the growth substrate 100 increases, light extraction efficiency can be improved. Meanwhile, the side surface of the growth substrate 100 may include a breaking surface.

The lower semiconductor layer 115 is disposed on one surface of the growth substrate 100 . The lower semiconductor layer 115 may cover the entire surface of one surface of the growth substrate 100, but is not limited thereto. 100) may be limited and positioned within the upper region.

The first upper semiconductor layer 111 is located above one region of the lower semiconductor layer 115 , and the active layer 113 is located between the lower semiconductor layer 115 and the upper semiconductor layer 111 . Furthermore, the second and third upper semiconductor layers 131 and 121 may be located on top of other regions of the lower semiconductor layer 115, and the second and third upper semiconductor layers 131 and 121 respectively and the lower An active layer 113 may be positioned between the semiconductor layers 115 .

The first upper semiconductor layer 111 may have an H shape or a dumbbell shape with a narrow waist, and thus, excellent light output characteristics may be implemented under a high current density condition.

The lower semiconductor layer 115 and the upper semiconductor layers 111, 121, and 131 may include a III-V series compound semiconductor, for example, a nitride-based semiconductor such as (Al, Ga, In)N. can do. The lower semiconductor layer 115 may include an n-type semiconductor layer doped with n-type impurities (eg, Si), and the upper semiconductor layers 111, 121, and 131 may include p-type impurities (eg, Si). Mg) may include a doped p-type semiconductor layer. Also, the opposite may be true. Furthermore, the lower semiconductor layer 115 and/or the upper semiconductor layers 111, 121, and 131 may be a single layer or may include multiple layers. For example, the lower semiconductor layer 115 and/or the upper semiconductor layers 111 , 121 , and 131 may include a cladding layer and a contact layer, or may include a superlattice layer.

The active layer 113 may include a multi-quantum well structure (MQW), and elements constituting the multi-quantum well structure and their composition may be adjusted so that light having a desired peak wavelength is emitted from the multi-quantum well structure. For example, the well layer of the active layer 113 may be a ternary semiconductor layer such as In _x Ga _(1-x) N (0≤x≤1), or Al _x In _y Ga _(1-xy) N ( 0≤x≤1, 0≤y≤1, 0≤x+y≤1), and at this time, the value of x or y may be adjusted to emit light of a desired peak wavelength. . However, the present invention is not limited thereto.

The above-described semiconductor layers 111, 113, 115, 121, and 131 may be formed by metal organic chemical vapor deposition (MOCVD), chemical vapor deposition (CVD), or plasma-enhanced chemical vapor deposition (PCVD). It may be formed through various deposition and growth methods including chemical vapor deposition (MBE), molecular beam epitaxy (MBE), hydride vapor phase epitaxy (HVPE), and the like.

Hereinafter, a description of well-known technical contents related to the semiconductor layers 111, 113, 115, 121, and 131 including III-V series compound semiconductors will be omitted.

Meanwhile, the first current spreading unit 120 and the second current spreading unit 130 may be disposed on one region of the lower semiconductor layer 115 . The first current spreading part 120 may be disposed in an area where the second bump 170 is to be formed. The first current spreading unit 120 may include semiconductor layers 115 , 123 , and 121 including a portion of the lower semiconductor layer 115 . That is, the first current spreading unit 120 is disposed between the second upper semiconductor layer 121 disposed on the other region of the lower semiconductor layer 115 and between the lower semiconductor layer 115 and the second upper semiconductor layer 121. It may include an active layer 123 disposed on. When current is injected through the second bump 170 , the first current spreading unit 120 may perform a function of spreading the current. That is, the first current spreading unit 120 blocks current from flowing linearly toward the lower semiconductor layer 115, thereby dispersing the current, thereby improving current spreading. The first current spreading unit 120 may have a height parallel to the light emitting cell 110 . That is, since the first current distributing part 120 has the same height as the light emitting cell 110, the second bump 170 disposed on the first current distributing part 120 and the light emitting cell 110 are disposed on each other. The step difference between the first bumps 180 may be overcome.

The second current spreading unit 130 may be disposed between the first current spreading unit 120 and the light emitting cell 110 . The second current spreading unit 130 may include semiconductor layers 131 , 133 , and 115 including a portion of the lower semiconductor layer 115 . That is, the second current spreading unit 130 is disposed between the third upper semiconductor layer 131 disposed on another region of the lower semiconductor layer 115 and the lower semiconductor layer 115 and the upper semiconductor layer 131. The disposed active layer 133 may be included.

When the current injected through the second bump 170 flows toward the light emitting cell 110, the second current spreading unit 130 disperses the current, thereby improving current spreading. The second current spreading unit 130 may have a height parallel to the light emitting cell 110 . In this embodiment, the shape and arrangement of the second current spreading unit 130 is not limited to the illustrated form. Accordingly, the second current spreading unit 130 may be arranged in various forms according to the purpose of the present invention. Also, the second current spreading unit 130 may be disposed closer to and farther from the light emitting cell 110 than the first current spreading unit 120 . The area and arrangement of the contact region between the second electrode 140 and the lower semiconductor layer 115 may be controlled through the second current spreading unit 130 .

The semiconductor layers included in the first current spreading unit 120 and the second current spreading unit 130 may be formed through the same process as the semiconductor layer included in the light emitting cell 110 described above. In addition, in this embodiment, the first current distributing unit 120 and the second current distributing unit 130 are illustrated as having inclined side surfaces, but the first and second current distributing units 120 and 130 The form of is not limited thereto. However, in this embodiment, the first and second current spreading units 120 and 130 may have flat upper surfaces.

Meanwhile, the second electrode 140 may be disposed on the lower semiconductor 115 and the first and second current spreading parts 120 and 130 except for the region where the light emitting cell 110 is disposed. The second electrode 140 may include a second contact layer 141 and a second pad layer 143 . The second electrode 140 may surround the first upper semiconductor layer 111 included in the light emitting cell 110 . In FIG. 2 , the second electrode 140 is illustrated as surrounding the entire periphery of the first upper semiconductor layer 111, but is not necessarily limited thereto. The second electrode 140 may extend to both sides of the first upper semiconductor layer 111 from where the second bump 170 is located, and may surround about 50% or more of the first upper semiconductor layer 111 . The second contact layer 141 may include at least one of Cr, Ti, Al, and Au, or may have a multilayer structure of Cr/Ti/Al/Ti/Au. When the second contact layer 141 has the above-described multi-layer structure, Cr has a thickness of about 100 Å, Ti has a thickness of about 200 Å, Al has a thickness of about 600 Å, Ti has a thickness of about 200 Å, and Au has a thickness of about 1000 Å, according to the above described order. It may be, but is not limited thereto. The second pad layer 123 may include Ti or Au, or may have a Ti/Au multilayer structure.

Meanwhile, the second electrode 140 may further include a reflective layer. The reflective layer may include at least one of Ni, Pt, Pd, Rh, W, Ti, Al, Ag, and Au, and may be formed as a multilayer including at least one of the above elements. However, it is not limited thereto.

The second electrode 140 may reflect light emitted from the active layer 113 included in the light emitting cell 110 through the reflective layer. Specifically, the light emitting diode according to the present invention includes current dispersing units 120 and 130, and due to the current distributing units 120 and 130, the light incident from the active layer 113 to the second electrode 140 is reduced. The critical angle may vary. Accordingly, much scattering of light incident on the second electrode 140 may occur. Since the second electrode 140 may include a reflective layer, the incident light may be reflected to the light extraction surface, thereby improving the light extraction efficiency of the light emitting diode.

The contact resistance between the second electrode 140 and the second upper semiconductor layer 121 included in the first current spreading unit 120 is higher than the contact resistance between the second electrode 140 and the lower semiconductor layer 115. can The contact resistance between the second electrode 140 and the third upper semiconductor layer 131 included in the second current distribution unit 130 is higher than the contact resistance between the second electrode 140 and the lower semiconductor layer 115. can In this embodiment, the lower semiconductor layer 115 may be an n-type doped semiconductor layer, and the upper semiconductor layers 111, 121, and 131 may be p-type doped semiconductor layers. Therefore, contact resistance between the second electrode 140 including metal and the lower semiconductor layer 115 may be lower than that between the upper semiconductor layers 111 , 121 , and 131 . Accordingly, the upper semiconductor layers 111, 121, and 131 may serve as a kind of resistance in the light emitting diode.

In the light emitting diode according to the prior art, when current is injected through the metal electrode, since the semiconductor layer in contact with the metal electrode has conductivity, the current flows through both the metal electrode and the semiconductor layer. In this embodiment, since the upper semiconductor layers 121 and 131 included in the first and second current spreading units 120 and 130 serve as a kind of resistance as described above, the lower semiconductor layer 115 and the second The area of the contact area of the two electrodes 140 can be controlled. Therefore, since the light emitting diode according to the present embodiment can induce current to flow mainly through the second electrode 140 surrounding at least a part of the light emitting cell 110, diffusion of the current can be improved.

In this embodiment, since contact between the second electrode 140 and the lower semiconductor layer 115 is blocked in the region where the second current spreading unit 130 and the first current spreading unit 120 are formed, the second electrode ( 140) and the lower semiconductor layer 115 may be reduced. Therefore, when the contact area is reduced, since the driving voltage of the light emitting diode can be increased, in order to maintain an appropriate driving voltage, with respect to the entire area of the second electrode 140, the second current distribution unit 130 and An area occupied by the sum of the upper surface areas of the first current spreading unit 120 may be 10 to 40%. When the sum of the areas of the upper surfaces of the second current spreading unit 130 and the first current spreading unit 120 is less than 10% of the area of the second electrode 140, improvements in current spreading, etc. It may be difficult to express the effect, and in the case of more than 40%, the driving voltage of the light emitting diode may be increased. Therefore, since the light emitting diode according to the present invention arranges the first and second current spreading units 130 and 120 within the above range, current spreading in the light emitting diode can be improved and a required driving voltage can be satisfied. .

In addition, in this embodiment, the second electrode 140 is shown in a form covering the second current spreading unit 130, but the present invention is not limited thereto. Therefore, the second electrode 140 according to the present invention may cover only a part of the second electrode.

Meanwhile, the first electrode 150 may be disposed on the light emitting cell 110 . The first electrode 150 may include a first contact layer 151 and a first pad layer 153 . The first electrode 150 may be positioned on the upper semiconductor layer 111 and electrically connected to the first upper semiconductor layer 111 . The first contact layer 151 may include at least one of Ni, Au, and Al, or may have a Ni/Au multilayer structure. In the case where the first contact layer 151 has the aforementioned multilayer structure, Ni may have a thickness of about 150 Å and Au may have a thickness of about 300 Å. The second pad layer 153 may include at least one of Ti, Au, and Cr, and may have a Ti/Au/Cr/Au multilayer structure. In the case where the second pad layer 153 has the above-described multilayer structure, Ti may be formed to have a thickness of about 300 Å, Au about 2 μm, Cr about 200 Å, and Au about 2.5 μm, in the order described above. . The first electrode 150 may form an ohmic contact with the first upper semiconductor layer 111 while having high reflectivity.

The first bump 180 is disposed on the first electrode 150 . The second bump 170 is disposed on the second electrode 160 . The first bump 180 may include a first area A1 and a second area A2. The first bump 180 may include a first concave portion and a first convex portion at an upper portion. The first area A1 may include the first concave portion, and thus, an upper surface of the first area A1 may correspond to a bottom surface of the first concave portion. The second area A2 may include the first convex portion, and thus, an upper surface of the second area A2 may correspond to an upper surface of the first convex portion.

The second bump 170 may include a third area A3 and a fourth area A4. The second bump 170 may include a second concave portion and a second convex portion at an upper portion. The third area A3 may include the second concave portion, and thus, an upper surface of the third area A3 may correspond to a bottom surface of the second concave portion. The fourth area A4 may include the second convex portion, and thus, an upper surface of the fourth area A4 may correspond to an upper surface of the second convex portion.

The second bump 170 and the first bump 180 may be formed of the same metal material. In addition, the first and second bumps 170 and 180 may be formed in a multi-layered structure, and may include, for example, an adhesive layer, an anti-diffusion layer, and a bonding layer. The adhesive layer may include, for example, Ti, Cr, or Ni, the anti-diffusion layer may be formed of Cr, Ni, Ti, W, TiW, Mo, Pt, or a composite layer thereof, and the bonding layer may include Au or AuSn may be included. The first and second bumps 170 and 180 may have a Ti/Au/Cr/Au multilayer structure. In this case, Ti is about 300 Å, Au is about 2 μm, Cr is about 200 Å, and Au is about 2.5 μm. thickness can be formed.

Meanwhile, the lower semiconductor layer 115 and the first and second current distributing parts 120 and 130 except for regions where the insulating layer 160 has the first bump 180 and the second bump 170 are disposed. , Covers and protects the first and second electrodes 140 and 150. The insulating layer 160 may include a silicon oxide layer and/or a silicon nitride layer. Furthermore, the insulating layer 160 may be formed of a distributed Bragg reflector (DBR) in which oxide layers having different refractive indices are stacked. In this case, the insulating layer 160 can reflect light on the inclined surface between the upper semiconductor layer 111 and the lower semiconductor layer 115 and the exposed portion of the lower semiconductor layer 115, further improving the light extraction efficiency of the light emitting diode. can In this embodiment, the insulating layer 160 may be formed of a multiple layer of a silicon oxide layer and a silicon nitride layer or a single layer of a silicon oxide layer, and when the insulating layer 160 is a multiple layer, the silicon oxide layer Silver may have a thickness of about 2400 Å, the silicon nitride layer may have a thickness of about 5000 Å, and when the insulating layer 160 is a single layer of silicon oxide, the silicon oxide layer may have a thickness of about 6000 Å. However, it is not limited thereto.

Since the silicon nitride layer has relatively excellent moisture barrier properties compared to the silicon oxide layer, moisture barrier characteristics of the light emitting diode can be further improved when the insulating layer 160 is a multilayer.

In the present invention, the first and second bumps 170 and 180 may be formed to cover a portion of the insulating layer 160 as shown. Accordingly, at least a portion of the second region A2 of the first bump 180 may be disposed on the insulating layer 160 . Furthermore, at least a portion of the fourth area A4 of the second bump 170 may be disposed on the insulating layer 160 . That is, a portion of the insulating layer 160 may be disposed between the first bump 180 and the first electrode 150 and/or between the second bump 170 and the second electrode 140 .

Referring back to FIG. 2 , the insulating layer 160 may include a first open area 150a exposing the first electrode 150 and a second open area 140a exposing the second electrode 140. there is. A side surface of the insulating layer 160 surrounding the first and second open areas 150a and 140a, respectively, may be exposed, and the exposed side surface may be exposed to the first bump 180 and/or the second bump 170. may be in contact.

In addition, reviewing the plan view (a) of FIG. 2 again, it can be seen that the area of the first open area 150a is smaller than the sum of the bottom surface of the first concave portion and the top surface of the first convex portion of the first bump 180. there is. In addition, it can be seen that the area of the second open area 140a is smaller than the sum of the bottom surface of the second concave portion and the top surface of the second convex portion of the second bump 170 . That is, in this embodiment, the first and second bumps 180 and 170 may completely cover the first open area 150a and the second open area 140a, respectively.

The first and second bumps 180 and 170 according to the present invention may cover the first and second electrodes 150 and 140 together with the insulating layer 160 . Accordingly, it is possible to prevent external moisture or the like from penetrating into the light emitting diode, thereby improving reliability of the light emitting diode. In addition, due to the concave portion and the convex portion disposed on each of the first and second bumps 180 and 170 according to the present invention, it has a stronger bonding force on the printed circuit board or sub-mount substrate than the prior art. can be mounted.

3 is a cross-sectional view for explaining a light emitting diode according to another embodiment of the present invention. The light emitting diode according to the present embodiment is identical to the light emitting diode according to the above-described embodiment except for the shape and arrangement of the second current spreading unit 130 . Therefore, redundant descriptions of the same components are omitted.

Referring to FIG. 3 , the second current spreading unit 130 includes at least one dispersion body, and the dispersion body has a rectangular shape with long sides in the vertical direction. Accordingly, since the current in the light emitting diode is distributed in the area where the second current spreading unit 130 is formed, current spreading can be improved.

As illustrated, the dispersing elements included in the second current spreading unit 130 may have the same shape and be arranged at regular intervals, or may be arranged with different shapes and intervals. The dispersions included in the second current spreading unit 130 may be disposed closer to the first current spreading unit 120 than to the light emitting cell 110 . That is, the distance between the light emitting cell 110 and the dispersion closest to the light emitting cell 110 among the dispersions included in the second current spreading unit 130 is the dispersion included in the second current spreading unit 130. Among the sieves, the distance between the first current dissipating unit 120 and the nearest dispersing unit may be wider than the distance between the first current dissipating unit 120 .

4 is a cross-sectional view for explaining a light emitting device according to an embodiment of the present invention.

Referring to FIG. 4 , the light emitting diode is a light emitting diode according to the above-described embodiments of the present invention, and the light emitting diode is mounted on the submount substrate 200 .

The submount substrate 200 includes a substrate 230 and an electrode pattern 220 disposed on the substrate 230 . The substrate 230 may be any one of BeO, SiC, Si, Ge, SiGe, AlN, and ceramic substrates having excellent thermal conductivity. However, the substrate is not limited thereto, and may be a substrate including an insulating material having high thermal conductivity as well as a metallic material having high thermal conductivity and excellent electrical conductivity.

The electrode patterns 220 are formed to correspond to the shapes of the second bumps 170 and the first bumps 180, and the second bumps 170 and the first bumps 180 are bonded to the electrode patterns 220, respectively. do. In this case, bonding may be performed by using heat or ultrasonic waves, or by using heat and ultrasonic waves at the same time. In addition, each of the electrode patterns 220 and the first bump 180 or the second bump 170 may be bonded using a solder paste.

However, it is not limited thereto, and the first and second bumps 180 and 170 and the electrode pattern 220 may be bonded in the bonding area 210 through various methods including the aforementioned bonding method.

5 is a perspective view for explaining a light emitting diode package according to an embodiment of the present invention.

Referring to FIG. 5 , the light emitting diode package includes a substrate including a first frame 311, a second frame 313, and an insulating layer 315 positioned between the first and second frames 311 and 313. 300, a light emitting diode 400 mounted in a cavity 317 formed on the upper surface of the substrate 300, a submount substrate 200, and a wire 30. The light emitting diode 400 is a light emitting diode according to embodiments of the present invention described above.

The first and second frames 311 and 313 may be metal frames or ceramic frames. When the first and second frames 311 and 313 are metal frames, they may include single metals or alloys including Al, Ag, Cu, and Ni having excellent electrical characteristics and heat dissipation.

The insulating layer 315 may include an adhesive part, and has a function of fixing the first and second frames 311 and 313 to both sides. Power may be supplied to the light emitting diode 400 by connecting power to the pads through the wire 330 .

The above description is merely an example of the technical idea of the present invention, and those skilled in the art can make various modifications, changes, and substitutions without departing from the essential characteristics of the present invention. will be. Therefore, the embodiments disclosed in the present invention and the accompanying drawings are not intended to limit the technical idea of the present invention, but to explain, and the scope of the technical idea of the present invention is not limited by these embodiments and the accompanying drawings. . The protection scope of the present invention should be construed according to the claims below, and all technical ideas within the equivalent range should be construed as being included in the scope of the present invention.

100: growth substrate
110: light emitting cell
111: upper semiconductor layer
113: active layer
115: lower semiconductor layer
120: first current distribution unit
130: second current distribution unit
121, 123, 131, 133: semiconductor layer
140: second electrode
140a: second open area
141: second contact layer
143: second pad layer
150: first electrode
150: first open area
151: first contact layer
153: first pad layer
160: insulating layer
170: second bump
180: first bump
200: submount substrate
210: bonding area
220: electrode pattern
311: first frame
313: second frame
315: insulating layer
317: cavity
330: wire
400: light emitting diode

Claims (20)

Board;
a lower semiconductor layer disposed on the substrate;
a light emitting cell including a first upper semiconductor layer disposed on one region of the lower semiconductor layer and an active layer disposed between the lower semiconductor layer and the first upper semiconductor layer;
a first current spreading unit including a second upper semiconductor layer disposed on another region of the lower semiconductor layer and an active layer disposed between the lower semiconductor layer and the second upper semiconductor layer;
It is disposed between the light emitting cell and the first current spreading part, and includes a third upper semiconductor layer disposed on the lower semiconductor layer and an active layer disposed between the lower semiconductor layer and the third upper semiconductor layer. current distribution unit;
a first electrode electrically connected to the first upper semiconductor layer; and
Including a second electrode electrically connected to the lower semiconductor layer,
A portion of the second electrode is disposed on the first current distributing part;
The second current spreading unit includes a plurality of dispersing elements,
The second electrode extends to cover at least a portion of each of the plurality of dispersion bodies of the second current spreading unit,
The plurality of dispersions have the same shape and are arranged at regular intervals. The method of claim 1,
The light emitting diode having a long surface in a vertical direction perpendicular to the left and right directions in which the light emitting cells and the first current spreading part are aligned when viewed from a plan view. The method of claim 1,
The second current spreading portion has a height parallel to the light emitting cell. The method of claim 1,
The first current spreading portion has a height parallel to the light emitting cell. The method of claim 1,
The first current distributing part and the second current distributing part include a flat top surface of the light emitting diode. The method of claim 1,
The light emitting diode of claim 1 , wherein the second electrode includes a reflective layer, and light emitted from the active layer is reflected from the reflective layer and emitted. The method of claim 6,
wherein the second electrode includes at least one of Ni, Pt, Pd, Rh, W, Ti, Al, Ag, and Au. The method of claim 1,
The lower semiconductor layer includes an n-type semiconductor layer,
Wherein the first upper semiconductor layer includes a p-type semiconductor layer. The method of claim 1,
The first electrode is a light emitting diode containing Ni / Au. The method of claim 1,
The light emitting diode of claim 1 , wherein the first current dissipation unit has an elongated shape along one direction together with the dispersants of the second current dissipation unit. The method of claim 10,
The light emitting cell may have a length along one direction greater than a width in a direction perpendicular to the one direction. The method of claim 1,
The second electrode covers all of the plurality of dispersion elements of the first current distributing unit and the second current distributing unit. The method of claim 12,
The first electrode is spaced apart from the second electrode in a horizontal direction. The method of claim 1,
The active layer of the light emitting cell, the active layer of the first current spreading part, and the active layer of the second current spreading part have the same multi-quantum well structure of the same composition. a substrate including a first frame, a second frame, and an insulating layer positioned between the first and second frames;
A light emitting diode package comprising the light emitting diode of any one of claims 1 to 14 disposed on the substrate. The method of claim 15
Wherein the first frame and the second frame are metal frames light emitting diode package. The method of claim 15
The light emitting diode package wherein the insulating layer includes an adhesive portion. The method of claim 15
The substrate includes a cavity on an upper surface,
The light emitting diode package disposed in the cavity. The method of claim 15
Including more submounts,
The light emitting diode package disposed on the sub-mount. The method of claim 15
The light emitting diode package further comprises wires for electrically connecting the light emitting diode to the first and second frames.

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