KR20140062945A

KR20140062945A - Light emitting device

Info

Publication number: KR20140062945A
Application number: KR1020120129276A
Authority: KR
Inventors: 김성균; 추성호; 나민규; 주현승
Original assignee: 엘지이노텍 주식회사
Priority date: 2012-11-15
Filing date: 2012-11-15
Publication date: 2014-05-27

Abstract

Embodiments relate to a light emitting device, a method of manufacturing a light emitting device, a light emitting device package, and an illumination system.
The light emitting device according to the embodiment includes a substrate 105; A first conductive semiconductor layer 112 on the substrate 105; An active layer 114 on the first conductive semiconductor layer 112; A second conductive semiconductor layer 116 on the active layer 114; A plurality of through holes (H) penetrating the second conductivity type semiconductor layer (116) and a part of the active layer (114) to expose a part of the first conductivity type semiconductor layer (112); A first insulating layer (151) formed on the second conductive type semiconductor layer; A first pad electrode 141a formed on the first insulating layer 151; A first branched electrode 141b connected to the first pad electrode 141a and formed on the first insulating layer 151; A second branched electrode formed in the through hole H and connected to the first branched electrode 141b and in contact with the first conductive semiconductor layer 112 exposed by the through hole H; And a second electrode 142 on the second conductive type semiconductor layer 116. [

Description

[0001] LIGHT EMITTING DEVICE [0002]

Embodiments relate to a light emitting device, a method of manufacturing a light emitting device, a light emitting device package, and an illumination system.

Light Emitting Device is a pn junction diode whose electrical energy is converted into light energy. It can be produced from compound semiconductor such as group III and group V on the periodic table and by controlling the composition ratio of compound semiconductor, It is possible.

When a forward voltage is applied to the light emitting device, electrons in the n-layer and holes in the p-layer are coupled to emit energy corresponding to the band gap energy of the conduction band and the valance band. Is mainly emitted in the form of heat or light, and when emitted in the form of light, becomes a light emitting element.

For example, nitride semiconductors have received great interest in the development of optical devices and high power electronic devices due to their high thermal stability and wide bandgap energy. Particularly, blue light emitting devices, green light emitting devices, ultraviolet (UV) light emitting devices, and the like using nitride semiconductors have been commercialized and widely used.

The nitride semiconductor light emitting device may be classified into a lateral type light emitting device and a vertical type light emitting device depending on the position of the electrode layer.

A horizontal type light emitting device is formed such that a nitride semiconductor layer is formed on a sapphire substrate and two electrode layers are disposed on the upper side of the nitride semiconductor layer.

Conventional horizontal light emitting devices have a large loss of the active layer because mesa etching proceeds over a large area.

In order to compensate for this, various attempts have been made to secure an active layer widely, but there is a problem such as an increase in a forward voltage (Vf).

Embodiments provide a light emitting device, a method of manufacturing a light emitting device, a light emitting device package, and an illumination system in which the operating voltage is not increased and reliability and light extraction efficiency are improved.

The light emitting device according to the embodiment includes a substrate 105; A first conductive semiconductor layer 112 on the substrate 105; An active layer 114 on the first conductive semiconductor layer 112; A second conductive semiconductor layer 116 on the active layer 114; A plurality of through holes (H) penetrating the second conductivity type semiconductor layer (116) and a part of the active layer (114) to expose a part of the first conductivity type semiconductor layer (112); A first insulating layer (151) formed on the second conductive type semiconductor layer; A first pad electrode 141a formed on the first insulating layer 151; A first branched electrode 141b connected to the first pad electrode 141a and formed on the first insulating layer 151; A second branched electrode 141c formed in the through hole H and connected to the first branched electrode 141b and in contact with the first conductive semiconductor layer 112 exposed by the through hole H; And a second electrode 142 on the second conductive type semiconductor layer 116. [

According to the light emitting device, the method of manufacturing the light emitting device, the light emitting device package, and the illumination system according to the embodiments, the size of the through hole through which the second branched electrode is formed is made larger than the width of the first branched electrode, It is possible to prevent the operating voltage from rising due to the lowering of the current mill.

In addition, the embodiment includes a first pad electrode and a first reflective layer formed under the first branched electrode, so that a thermally stable material is applied to the first pad electrode regardless of the reflectivity of the material of the first pad electrode and the first branched electrode, It can be adopted as one electrode material and the stability of the device can be achieved and the light emitted by the first reflection layer is reflected to be extracted to the outside to increase the light extraction efficiency.

In addition, according to the embodiment, the power drop, which is a disadvantage of the prior art, can be minimized and the current can be uniformly injected into the active layer as a whole, so that the light efficiency can be increased.

1 is a top view of a light emitting device according to an embodiment.
2 is a projection view of a light emitting device according to an embodiment.
3 is a partial cross-sectional view of a light emitting device according to an embodiment.
4 to 5 are process sectional views of a light emitting device according to an embodiment.
6 is a cross-sectional view of a light emitting device package according to an embodiment.
7 to 9 are views showing a lighting apparatus according to an embodiment.
10 and 11 are views showing another example of the lighting apparatus according to the embodiment.
12 is a perspective view of a backlight unit according to an embodiment;

In the description of the embodiments, it is to be understood that each layer (film), area, pattern or structure may be referred to as being "on" or "under" the substrate, each layer Quot; on "and" under "are intended to include both" directly "or" indirectly " do. Also, the criteria for top, bottom, or bottom of each layer will be described with reference to the drawings.

The thickness and size of each layer in the drawings are exaggerated, omitted, or schematically shown for convenience and clarity of explanation. Also, the size of each component does not entirely reflect the actual size.

(Example)

1 is a top view of a light emitting device according to an embodiment, and FIG. 2 is a projection view of a light emitting device according to an embodiment. 2 is a diagram illustrating a first reflective layer 121 and a second reflective layer 122 formed under the first electrode 141 and the second electrode 142 in the light emitting device according to the embodiment.

3 is a partial cross-sectional view of a light emitting device according to an embodiment, specifically, taken along the line I-I 'in Fig.

The light emitting device according to the embodiment includes a first conductive semiconductor layer 112 on the substrate 105, an active layer 114 on the first conductive semiconductor layer 112, And a second conductivity type semiconductor layer 116.

In order to solve this problem, in the embodiment, a chip can be designed so that the active layer is wide.

For example, the embodiment may include a plurality of through holes H that penetrate the second conductivity type semiconductor layer 116 and a part of the active layer 114 to expose a part of the first conductivity type semiconductor layer 112, . &Lt; / RTI >

The first insulating layer 151 formed on the second conductive type semiconductor layer and the second insulating layer 152 formed on the sidewall of the through hole H can prevent electrical shorting.

The first conductive semiconductor layer 116 may be formed on the first conductive semiconductor layer 116. The first conductive semiconductor layer 116 may include a first pad electrode 141a formed on the first insulating layer 151, A first conductive semiconductor layer 112 formed in the through hole H and connected to the first branched electrode 141b and exposed through the through hole H, And a second branched electrode 141c.

The first branched electrode 141a, the first branched electrode 141b and the second branched electrode 141c may form the first electrode 141, but the present invention is not limited thereto.

The second branched electrode 141c formed on the sidewall of the through hole H may be formed on the second insulating layer 152.

The second conductivity type semiconductor layer 116 may include a second electrode 142 and the second conductivity type semiconductor layer 116 may include a second electrode 142. The second conductivity type semiconductor layer 116 may include a second electrode 142, A second pad electrode 142a and a third branched electrode 142b connected to the second pad electrode 142a and disposed on the second conductive semiconductor layer 116. [ The third branched electrode 142b may make point contact with the second conductive type semiconductor layer 116, but the present invention is not limited thereto.

The second branched electrode 141c may be in direct contact with the first conductive semiconductor layer 112 in the region exposed by the through hole H in the embodiment. In consideration of the fact that the region where the active layer is removed is minimized to maximize the light emitting region and the electron mobility is high, the point contact It is possible to maximize the light efficiency by securing the light emitting region and optimizing the carrier injection efficiency at the same time.

On the other hand, as in the embodiment, there is a fear that the operating voltage (Forward Voltage, Vf) increases due to a high current density at a portion where branch electrodes are locally bonded to the first conductivity type semiconductor layer 112 for point contact have.

In order to prevent an increase in the operating voltage, in the embodiment, the size of the through hole H in which the second branched electrode 141c is formed is made larger than the width of the first branched electrode 141b, The region directly bonded to the layer 112 can be widely secured, and the current density in the local contact region can be reduced to prevent the operating voltage (Vf) from rising.

In the embodiment, the shape of the through hole H may be circular, square, line type or the like. The size of the through hole H may be a diameter in the case of a circle, a length of one side in the case of a quadrangle, But is not limited thereto.

For example, the size of the through hole H in which the second branched electrode 141c is formed is formed to be three times or more the width of the first branched electrode 141b, The current density can be lowered at the locally bonded portion to prevent the operating voltage from rising.

In addition, in the embodiment, the size of the through hole H in which the second branched electrode 141c is formed is controlled to be about 3 占 퐉 to a size smaller than 1/2 of the upper surface of the light emitting element, It is possible to prevent the operating voltage from rising.

The conventional technology uses a reflective metal of Al or Ag series to improve the light extraction efficiency. However, these materials are characterized in that physical properties are changed at a relatively high temperature as compared with other metal materials, The physical properties are changed and the electrical characteristics are lowered, which is a major factor for raising the operating voltage Vf.

The embodiment of the present invention includes the first pad electrode 141a and the first reflective layer 121 formed under the first branched electrode 141b so that the first pad electrode 141a and the first branched electrode 141b The first pad electrode 141a and the first branched electrode 141b can be made of a material that is thermally stable regardless of the reflectance regardless of the reflectivity of the material, It is possible to increase the light extraction efficiency by reflecting the emitted light and extracting it to the outside.

The horizontal cross section of the first reflective layer 121 may be larger than the horizontal cross section of the first branched electrode 141b, the second branched electrode 141c, and the first pad electrode 141a, The efficiency can be increased.

For example, the width of the first reflective layer 121 is greater than the horizontal width of the first branched electrode 141b and is controlled to be about 5 times or less the horizontal width of the first branched electrode 141b, And the light extraction efficiency can be increased at the same time.

The embodiment may further include a second reflective layer 122 formed under the second electrode 142.

In this embodiment, the first reflective layer 121 or the second reflective layer 122 may be a DBR (Distributed Bragg Reflector), and DBR may be mλ / 4n (where λ is the wavelength of the light, n is the refractive index of the medium, And the reflectance of 95% or more can be obtained in the light of the specific wavelength band (?). However, the present invention is not limited thereto. For example, the first reflective layer 121 or the second reflective layer 122 may be formed of SiO ₂ / TiO ₂ , SiN _x / TiO ₂ , SiO ₂ / TiN _x , But the present invention is not limited thereto.

According to the light emitting device according to the embodiment, the power drop, which is a disadvantage of the prior art, can be minimized and the current can be uniformly injected into the active layer as a whole, so that the light efficiency can be increased.

According to an embodiment of the present invention, the size of the through hole H in which the second branched electrode 141c is formed is made larger than the width of the first branched electrode 141b, It is possible to prevent the operating voltage from rising due to the lowering of the current density at the portion to be bonded.

The embodiment also includes the first pad electrode 141a and the first branched electrode 141b including the first pad electrode 141a and the first reflective layer 121 formed under the first branched electrode 141b. A thermally stable material can be employed as the material of the first pad electrode 141a and the first branched electrode 141b regardless of the reflectance so that the stability of the device can be achieved and the first reflective layer 121 to be extracted to the outside, thereby increasing the light extraction efficiency.

Hereinafter, a method of manufacturing a light emitting device according to an embodiment will be described with reference to FIGS.

First, the substrate 105 is prepared as shown in Fig. The substrate 105 may be formed of a material having excellent thermal conductivity, and may be a conductive substrate or an insulating substrate. For example, the substrate 105 is a sapphire (Al ₂ O _3), SiC, Si, GaAs, GaN, ZnO, GaP, InP, Ge, and Ga ₂ 0 ₃ May be used. A concavo-convex structure may be formed on the substrate 105, but the present invention is not limited thereto. The first substrate 105 may be wet-cleaned to remove impurities on the surface.

The light emitting structure 110 including the first conductivity type semiconductor layer 112, the active layer 114, and the second conductivity type semiconductor layer 116 may be formed on the substrate 105.

At this time, in the embodiment, a buffer layer (not shown) may be formed on the substrate 105. The buffer layer may mitigate the lattice mismatch between the material of the light emitting structure 110 and the substrate 105 and the material of the buffer layer may be a Group III-V compound semiconductor such as GaN, InN, AlN, InGaN, AlGaN, InAlGaN , And AlInN.

In addition, the embodiment may form an undoped semiconductor layer (not shown) on the buffer layer, but the embodiment is not limited thereto.

The first conductive semiconductor layer 112 may be formed of a semiconductor compound. Group 3-Group 5, Group 2-Group 6, and the like, and the first conductive type dopant may be doped. When the first conductive semiconductor layer 112 is an n-type semiconductor layer, the first conductive dopant may include Si, Ge, Sn, Se, and Te as an n-type dopant.

The first conductive semiconductor layer 112 may include a semiconductor material having a composition formula of In _x Al _y Ga ₁ _-x- _y N (0? X? 1, 0? _Y? 1, 0? _X + .

The first conductive semiconductor layer 112 may be formed of one or more of GaN, InN, AlN, InGaN, AlGaN, InAlGaN, AlInN, AlGaAs, InGaAs, AlInGaAs, GaP, AlGaP, InGaP, AlInGaP and InP.

The first conductive semiconductor layer 112 may be formed by a CVD method or molecular beam epitaxy (MBE), sputtering, or vapor phase epitaxy (HVPE). . The first conductive semiconductor layer 112 may be formed by depositing a silane containing an n-type impurity such as trimethyl gallium gas (TMGa), ammonia gas (NH ₃ ), nitrogen gas (N ₂ ) Gas (SiH ₄ ) may be implanted and formed.

Next, a current diffusion layer (not shown) is formed on the first conductive type semiconductor layer 112. The current diffusion layer may be an undoped GaN layer, but is not limited thereto.

Next, in the embodiment, an electron injection layer (not shown) may be formed on the current diffusion layer. The electron injection layer may be a first conductivity type gallium nitride layer. For example, the electron injection layer may be the electron injection efficiently by being doped at a concentration of the n-type doping element ^{6.0x10 18 atoms / cm 3 ~ 8.0x10} 18 atoms / cm 3. The electron injection layer may be formed to a thickness of about 1000 Å or less, but is not limited thereto.

In addition, the embodiment can form a strain control layer (not shown) on the electron injection layer. For example, a strain control layer formed of In _y Al _x Ga _(1-xy) N (0? X? 1, 0? _Y? 1) / GaN or the like can be formed on the electron injection layer.

The strain control layer can effectively alleviate the stress that is caused by the lattice mismatch between the first conductive semiconductor layer 112 and the active layer 114.

Further, as the strain control layer is repeatedly laminated in at least six cycles having compositions such as first In _x1 GaN and second In _x2 GaN, more electrons are collected at a low energy level of the active layer 114, The probability of recombination of holes is increased and the luminous efficiency can be improved.

Thereafter, the active layer 114 is formed on the strain control layer.

Electrons injected through the first conductive type semiconductor layer 112 and holes injected through the second conductive type semiconductor layer 116 formed after the first and second conductive type semiconductor layers 116 and 116 are mutually combined to form an energy band unique to the active layer Which emits light having an energy determined by < RTI ID = 0.0 >

The active layer 114 may be formed of at least one of a single quantum well structure, a multi quantum well (MQW) structure, a quantum-wire structure, or a quantum dot structure. For example, the active layer 114 may be formed with a multiple quantum well structure by injecting trimethyl gallium gas (TMGa), ammonia gas (NH ₃ ), nitrogen gas (N ₂ ), and trimethyl indium gas (TMIn) But is not limited thereto.

The well layer / barrier layer of the active layer 114 may be formed of any one or more pairs of InGaN / GaN, InGaN / InGaN, GaN / AlGaN, InAlGaN / GaN, GaAs (InGaAs) / AlGaAs, GaP But is not limited thereto. The well layer may be formed of a material having a band gap lower than the band gap of the barrier layer.

In the embodiment, an electron blocking layer (not shown) is formed on the active layer 114 to serve as electron blocking and cladding of the active layer, thereby improving the luminous efficiency. For example, the electron blocking layer may be formed of an Al _x In _y Ga _(1-xy) N (0? _X _{? 1, 0?} _Y _{? 1} ) semiconductor, And may be formed to a thickness of about 100 A to about 600 A, but the present invention is not limited thereto.

The electron blocking layer may be formed of a superlattice of Al _z Ga _(1-z) N / GaN (0? _Z ? 1), but is not limited thereto.

The electron blocking layer can efficiently block the electrons that are ion-implanted into the p-type and overflow, and increase the hole injection efficiency. For example, the electron blocking layer can effectively prevent electrons that are overflowed by ion implantation of Mg in a concentration range of about 10 ¹⁸ to 10 ²⁰ / cm ³ , and increase the hole injection efficiency.

The embodiment may improve the luminous efficiency by forming an electron blocking layer on the active layer 114 to serve as electron blocking and cladding of the active layer. Lt; RTI ID = 0.0 > 114 < / RTI >

The second conductive semiconductor layer 116 may be formed of a semiconductor compound. 3-group-5, group-2-group-6, and the like, and the second conductivity type dopant may be doped.

For example, the second conductive semiconductor layer 116 may have a composition formula of In _x Al _y Ga ₁ _-x- _y N (0? X? 1, 0? _Y? 1, 0? _X + And the like. When the second conductive semiconductor layer 116 is a P-type semiconductor layer, the second conductive dopant may include Mg, Zn, Ca, Sr, and Ba as a P-type dopant.

The second conductive type semiconductor layer 116 is Bisei that the chamber comprises a p-type impurity such as trimethyl gallium gas (TMGa), ammonia gas (NH _3), nitrogen gas (N _2), and magnesium (Mg) butyl bicyclo The p-type GaN layer may be formed by implanting pentadienyl magnesium (EtCp ₂ Mg) {Mg (C ₂ H ₅ C ₅ H ₄ ) ₂ }, but the present invention is not limited thereto.

In an embodiment, the first conductive semiconductor layer 112 may be an n-type semiconductor layer, and the second conductive semiconductor layer 116 may be a p-type semiconductor layer. Also, on the second conductive semiconductor layer 116, a semiconductor (e.g., an n-type semiconductor) (not shown) having a polarity opposite to that of the second conductive type may be formed. Accordingly, the light emitting structure 110 may have any one of an n-p junction structure, a p-n junction structure, an n-p-n junction structure, and a p-n-p junction structure.

Thereafter, a first reflective layer 121 is formed on the second conductive type semiconductor layer 116. The second reflective layer 122 may be formed below the second electrode 142.

In the embodiment, the first reflective layer 121 or the second reflective layer 122 may be a distributed Bragg reflector (DBR), and DBR may be expressed by mλ / 4n (where λ is the wavelength of the light, n is the index of refraction of the medium, ), And it is possible to obtain a reflectance of 95% or more in light of a specific wavelength band (?), But the present invention is not limited thereto.

For example, the first reflective layer 121 or the second reflective layer 122 may be formed of a material such as SiO ₂ / TiO ₂ , SiN _x / TiO ₂ , or SiO ₂ / TiN _x . However, the present invention is not limited thereto.

The first embodiment includes a first pad electrode 141a to be formed later and a first reflective layer 121 formed under the first branched electrode 141b to form the first pad electrode 141a and the first branched electrode 141b A thermally stable material can be employed as the first pad electrode 141a and the first branched electrode 141b material irrespective of the reflectance of the material so that the stability of the device can be achieved and the first reflective layer 121 can emit light Reflected light is extracted and extracted to the outside, so that the light extraction efficiency can be increased.

The horizontal section of the first reflective layer 121 is disposed larger than the horizontal cross section of the first branched electrode 141b, the second branched electrode 141c, and the first pad electrode 141a, thereby increasing the light extraction efficiency .

Next, a light-transmitting electrode 130 may be formed on the first reflective layer 121.

The light-transmitting electrode 130 may be formed by laminating a single metal, a metal alloy, a metal oxide, or the like so as to efficiently perform carrier injection. For example, the light-transmitting electrode 130 may be formed of an excellent material in electrical contact with a semiconductor.

For example, the transmissive electrode 130 may be formed of a material selected from the group consisting of ITO (indium tin oxide), IZO (indium zinc oxide), IZTO (indium zinc tin oxide), IAZO (indium aluminum zinc oxide), IGZO (ZnO), indium gallium tin oxide (AZO), aluminum zinc oxide (AZO), antimony tin oxide (ATO), gallium zinc oxide (GZO), IZON nitride, AGZO Ag, Ni, Cr, Ti, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Ni, IrOx / Au, and Ni / IrOx / , Au, and Hf, and is not limited to such a material.

5, a plurality of through holes (not shown) may be formed in the second conductivity type semiconductor layer 116 and a part of the active layer 114 to expose a portion of the first conductivity type semiconductor layer 112, (H).

The embodiment can prevent electrical shorting through the first insulating layer 151 formed on the second conductive type semiconductor layer and the second insulating layer 152 formed on the side wall of the through hole H. [

The second branched electrode 141c may be in direct contact with only the region exposed by the first conductive semiconductor layer 112 and the through hole H in the embodiment. In consideration of the fact that the region where the active layer is removed is minimized to maximize the light emitting region and the electron mobility is high, the point contact It is possible to maximize the light efficiency by securing the light emitting region and optimizing the carrier injection efficiency at the same time.

The size of the through hole H in which the second branched electrode 141c is formed is greater than the width of the first branched electrode 141b in the embodiment, It is possible to prevent an increase in the operating voltage (Forward Voltage, Vf) by lowering the current density in the portion where the voltage is applied.

For example, the size of the through hole H in which the second branched electrode 141c is formed is formed to be three times or more the width of the first branched electrode 141b, It is possible to prevent the operating voltage from rising by lowering the current mill at the locally bonded portion.

6 is a view illustrating a light emitting device package 200 provided with a light emitting device according to embodiments.

The light emitting device package 200 according to the embodiment includes a package body 205, a third electrode layer 213 and a fourth electrode layer 214 provided on the package body 205, a package body 205, And a molding member 230 surrounding the light emitting device 100. The light emitting device 100 is electrically connected to the third electrode layer 213 and the fourth electrode layer 214,

The package body 205 may be formed of a silicon material, a synthetic resin material, or a metal material, and the inclined surface may be formed around the light emitting device 100.

The third electrode layer 213 and the fourth electrode layer 214 are electrically isolated from each other and provide power to the light emitting device 100. The third electrode layer 213 and the fourth electrode layer 214 may function to increase light efficiency by reflecting the light generated from the light emitting device 100, And may serve to discharge heat to the outside.

The light emitting device 100 may be a horizontal type light emitting device as illustrated in FIG. 1, but is not limited thereto. Vertical light emitting devices and flip chip light emitting devices may also be used.

The light emitting device 100 may be mounted on the package body 205 or on the third electrode layer 213 or the fourth electrode layer 214.

The light emitting device 100 may be electrically connected to the third electrode layer 213 and / or the fourth electrode layer 214 by a wire, flip chip, or die bonding method. The light emitting device 100 is electrically connected to the third electrode layer 213 through the wire 230 and is electrically connected to the fourth electrode layer 214 directly.

The molding member 230 surrounds the light emitting device 100 to protect the light emitting device 100. In addition, the molding member 230 may include a phosphor 232 to change the wavelength of light emitted from the light emitting device 100.

A light guide plate, a prism sheet, a diffusion sheet, a fluorescent sheet, and the like, which are optical members, may be disposed on a path of light emitted from the light emitting device package. The light emitting device package, the substrate, and the optical member may function as a backlight unit or function as a lighting unit. For example, the lighting system may include a backlight unit, a lighting unit, a pointing device, a lamp, and a streetlight.

7 to 9 are views showing a lighting apparatus according to an embodiment.

FIG. 7 is a perspective view of the illumination device according to the embodiment viewed from above, FIG. 8 is a perspective view of the illumination device shown in FIG. 7, and FIG. 9 is an exploded perspective view of the illumination device shown in FIG.

7 to 9, the illumination device according to the embodiment includes a cover 2100, a light source module 2200, a heat discharger 2400, a power supply unit 2600, an inner case 2700, a socket 2800, . &Lt; / RTI > Further, the illumination device according to the embodiment may further include at least one of the member 2300 and the holder 2500. The light source module 2200 may include a light emitting device or a light emitting device package according to the embodiment.

For example, the cover 2100 may have a shape of a bulb or a hemisphere, and may be provided in a shape in which the hollow is hollow and a part is opened. The cover 2100 may be optically coupled to the light source module 2200. For example, the cover 2100 may diffuse, scatter, or excite light provided from the light source module 2200. The cover 2100 may be a kind of optical member. The cover 2100 may be coupled to the heat discharging body 2400. The cover 2100 may have an engaging portion that engages with the heat discharging body 2400.

The inner surface of the cover 2100 may be coated with a milky white paint. Milky white paints may contain a diffusing agent to diffuse light. The surface roughness of the inner surface of the cover 2100 may be larger than the surface roughness of the outer surface of the cover 2100. This is for sufficiently diffusing and diffusing the light from the light source module 2200 and emitting it to the outside.

The cover 2100 may be made of glass, plastic, polypropylene (PP), polyethylene (PE), polycarbonate (PC), or the like. Here, polycarbonate is excellent in light resistance, heat resistance and strength. The cover 2100 may be an opaque layer 126 and may be opaque so that the light source module 2200 is visible from the outside. The cover 2100 may be formed by blow molding.

The light source module 2200 may be disposed on one side of the heat discharging body 2400. Accordingly, heat from the light source module 2200 is conducted to the heat discharger 2400. The light source module 2200 may include a light source unit 2210, a connection plate 2230, and a connector 2250.

The member 2300 is disposed on the upper surface of the heat discharging body 2400 and has guide grooves 2310 through which the plurality of light source portions 2210 and the connector 2250 are inserted. The guide groove 2310 corresponds to the substrate of the light source unit 2210 and the connector 2250.

The surface of the member 2300 may be coated or coated with a light reflecting material. For example, the surface of the member 2300 may be coated or coated with a white paint. The member 2300 reflects the light reflected by the inner surface of the cover 2100 toward the cover 2100 in the direction toward the light source module 2200. Therefore, the light efficiency of the illumination device according to the embodiment can be improved.

The member 2300 may be made of an insulating material, for example. The connection plate 2230 of the light source module 2200 may include an electrically conductive material. Therefore, electrical contact can be made between the heat discharging body 2400 and the connecting plate 2230. The member 2300 may be formed of an insulating material to prevent an electrical short circuit between the connection plate 2230 and the heat discharging body 2400. The heat discharger 2400 receives heat from the light source module 2200 and heat from the power supply unit 2600 to dissipate heat.

The holder 2500 blocks the receiving groove 2719 of the insulating portion 2710 of the inner case 2700. Therefore, the power supply unit 2600 housed in the insulating portion 2710 of the inner case 2700 is sealed. The holder 2500 has a guide protrusion 2510. The guide protrusion 2510 has a hole through which the protrusion 2610 of the power supply unit 2600 passes.

The power supply unit 2600 processes or converts an electrical signal provided from the outside and provides the electrical signal to the light source module 2200. The power supply unit 2600 is housed in the receiving groove 2719 of the inner case 2700 and is sealed inside the inner case 2700 by the holder 2500.

The power supply unit 2600 may include a protrusion 2610, a guide 2630, a base 2650, and an extension 2670.

The guide portion 2630 has a shape protruding outward from one side of the base 2650. The guide portion 2630 may be inserted into the holder 2500. A plurality of components may be disposed on one side of the base 2650. The plurality of components include, for example, a DC converter for converting AC power supplied from an external power source into DC power, a driving chip for controlling driving of the light source module 2200, an ESD (ElectroStatic discharge) protective device, and the like, but the present invention is not limited thereto.

The extension portion 2670 has a shape protruding outward from the other side of the base 2650. The extension portion 2670 is inserted into the connection portion 2750 of the inner case 2700 and receives an external electrical signal. For example, the extension portion 2670 may be provided to be equal to or smaller than the width of the connection portion 2750 of the inner case 2700. One end of each of the positive wire and the negative wire is electrically connected to the extension portion 2670 and the other end of the positive wire and the negative wire are electrically connected to the socket 2800 .

The inner case 2700 may include a molding part together with the power supply part 2600. The molding part is a hardened portion of the molding liquid so that the power supply unit 2600 can be fixed inside the inner case 2700.

10 and 11 are views showing another example of the lighting apparatus according to the embodiment.

FIG. 10 is a perspective view of a lighting apparatus according to the embodiment, and FIG. 11 is an exploded perspective view of the lighting apparatus shown in FIG.

10 and 11, the lighting device according to the embodiment includes a cover 3100, a light source 3200, a heat sink 3300, a circuit portion 3400, an inner case 3500, and a socket 3600 . The light source unit 3200 may include a light emitting device or a light emitting device package according to the embodiment.

The cover 3100 has a bulb shape and is hollow. The cover 3100 has an opening 3110. The light source unit 3200 and the member 3350 can be inserted through the opening 3110. [

The cover 3100 may be coupled to the heat discharging body 3300 and surround the light source unit 3200 and the member 3350. The light source part 3200 and the member 3350 may be shielded from the outside by the combination of the cover 3100 and the heat discharging body 3300. The coupling between the cover 3100 and the heat discharging body 3300 may be combined through an adhesive, or may be combined by various methods such as a rotational coupling method and a hook coupling method. The rotation coupling method is a method in which the cover 3100 is coupled with the heat discharging body 3300 by the rotation of the cover 3100 in such a manner that the thread of the cover 3100 is engaged with the thread groove of the heat discharging body 3300 In the hook coupling method, the protrusion of the cover 3100 is inserted into the groove of the heat discharging body 3300, and the cover 3100 and the heat discharging body 3300 are coupled.

The cover 3100 is optically coupled to the light source unit 3200. Specifically, the cover 3100 may diffuse, scatter, or excite light from the light emitting device 3230 of the light source unit 3200. The cover 3100 may be a kind of optical member. Here, the cover 3100 may have a phosphor inside / outside or in the inside thereof to excite light from the light source part 3200.

The inner surface of the cover 3100 may be coated with a milky white paint. Here, the milky white paint may include a diffusing agent for diffusing light. The surface roughness of the inner surface of the cover 3100 may be larger than the surface roughness of the outer surface of the cover 3100. This is for sufficiently scattering and diffusing light from the light source part 3200.

The cover 3100 may be made of glass, plastic, polypropylene (PP), polyethylene (PE), polycarbonate (PC), or the like. Here, polycarbonate is excellent in light resistance, heat resistance and strength. The cover 3100 may be a transparent material that can be seen from the outside of the light source unit 3200 and the member 3350, and may be an invisible and opaque material. The cover 3100 may be formed, for example, by blow molding.

The light source unit 3200 is disposed on the member 3350 of the heat sink 3300 and may be disposed in a plurality of units. Specifically, the light source portion 3200 may be disposed on at least one of the plurality of side surfaces of the member 3350. The light source unit 3200 may be disposed at the upper end of the member 3350.

11, the light source 3200 may be disposed on three of the six sides of the member 3350. However, the present invention is not limited thereto, and the light source portion 3200 may be disposed on all the sides of the member 3350. The light source unit 3200 may include a substrate 3210 and a light emitting device 3230. The light emitting device 3230 may be disposed on one side of the substrate 3210.

The substrate 3210 has a rectangular plate shape, but is not limited thereto and may have various shapes. For example, the substrate 3210 may have a circular or polygonal plate shape. The substrate 3210 may be a printed circuit pattern on an insulator. For example, the substrate 3210 may be a printed circuit board (PCB), a metal core PCB, a flexible PCB, a ceramic PCB . &Lt; / RTI > In addition, a COB (Chips On Board) type that can directly bond an unpackaged LED chip on a printed circuit board can be used.

In addition, the substrate 3210 may be formed of a material that efficiently reflects light, or may be formed of a color whose surface efficiently reflects light, for example, white, silver, or the like. The substrate 3210 may be electrically connected to the circuit unit 3400 housed in the heat discharging body 3300. The substrate 3210 and the circuit portion 3400 may be connected, for example, via a wire. The wire may pass through the heat discharging body 3300 to connect the substrate 3210 and the circuit unit 3400.

The light emitting device 3230 may be a light emitting diode chip that emits red, green, or blue light, or a light emitting diode chip that emits UV light. Here, the light emitting diode chip may be a lateral type or a vertical type, and the light emitting diode chip may emit blue, red, yellow, or green light. .

The light emitting device 3230 may have a phosphor. The phosphor may be at least one of a garnet system (YAG, TAG), a silicate system, a nitride system, and an oxynitride system. Alternatively, the fluorescent material may be at least one of a yellow fluorescent material, a green fluorescent material, and a red fluorescent material.

The heat discharging body 3300 may be coupled to the cover 3100 to dissipate heat from the light source unit 3200. The heat discharging body 3300 has a predetermined volume and includes an upper surface 3310 and a side surface 3330. A member 3350 may be disposed on the upper surface 3310 of the heat discharging body 3300. An upper surface 3310 of the heat discharging body 3300 can be engaged with the cover 3100. The upper surface 3310 of the heat discharging body 3300 may have a shape corresponding to the opening 3110 of the cover 3100.

A plurality of radiating fins 3370 may be disposed on the side surface 3330 of the heat discharging body 3300. The radiating fin 3370 may extend outward from the side surface 3330 of the heat discharging body 3300 or may be connected to the side surface 3330. The heat dissipation fin 3370 may increase the heat dissipation area of the heat dissipator 3300 to improve heat dissipation efficiency. Here, the side surface 3330 may not include the radiating fin 3370.

The member 3350 may be disposed on the upper surface 3310 of the heat discharging body 3300. The member 3350 may be integral with the top surface 3310 or may be coupled to the top surface 3310. The member 3350 may be a polygonal column.

Specifically, the member 3350 may be a hexagonal column. The hexagonal column member 3350 has an upper surface, a lower surface, and six sides. Here, the member 3350 may be a circular column or an elliptic column as well as a polygonal column. When the member 3350 is a circular column or an elliptic column, the substrate 3210 of the light source portion 3200 may be a flexible substrate.

The light source unit 3200 may be disposed on six sides of the member 3350. The light source unit 3200 may be disposed on all six sides and the light source unit 3200 may be disposed on some of the six sides. In Fig. 11, the light source unit 3200 is disposed on three sides of six sides.

The substrate 3210 is disposed on a side surface of the member 3350. The side surface of the member 3350 may be substantially perpendicular to the upper surface 3310 of the heat discharging body 3300. Accordingly, the upper surface 3310 of the substrate 3210 and the heat discharging body 3300 may be substantially perpendicular to each other.

The material of the member 3350 may be a material having thermal conductivity. This is to receive the heat generated from the light source 3200 quickly. The material of the member 3350 may be, for example, aluminum (Al), nickel (Ni), copper (Cu), magnesium (Mg), silver (Ag), tin (Sn) Or the member 3350 may be formed of a thermally conductive plastic having thermal conductivity. Thermally conductive plastics are advantageous in that they are lighter in weight than metals and have unidirectional thermal conductivity.

The circuit unit 3400 receives power from the outside and converts the supplied power to the light source unit 3200. The circuit unit 3400 supplies the converted power to the light source unit 3200. The circuit unit 3400 may be disposed on the heat discharging body 3300. Specifically, the circuit unit 3400 may be housed in the inner case 3500 and stored in the heat discharging body 3300 together with the inner case 3500. The circuit portion 3400 may include a circuit board 3410 and a plurality of components 3430 mounted on the circuit board 3410.

The circuit board 3410 has a circular plate shape, but is not limited thereto and may have various shapes. For example, the circuit board 3410 may be in the shape of an oval or polygonal plate. Such a circuit board 3410 may be one in which a circuit pattern is printed on an insulator. The circuit board 3410 is electrically connected to the substrate 3210 of the light source unit 3200. The electrical connection between the circuit board 3410 and the substrate 3210 may be connected by wire, for example. The wires may be disposed inside the heat discharging body 3300 to connect the circuit board 3410 and the substrate 3210.

The plurality of components 3430 include, for example, a DC converter for converting AC power supplied from an external power source to DC power, a driving chip for controlling the driving of the light source 3200, An electrostatic discharge (ESD) protection device, and the like.

The inner case 3500 houses the circuit portion 3400 therein. The inner case 3500 may have a receiving portion 3510 for receiving the circuit portion 3400. The receiving portion 3510 may have a cylindrical shape as an example. The shape of the accommodating portion 3510 may vary depending on the shape of the heat discharging body 3300. The inner case 3500 may be housed in the heat discharging body 3300. The receiving portion 3510 of the inner case 3500 may be received in a receiving portion formed on the lower surface of the heat discharging body 3300.

The inner case 3500 may be coupled to the socket 3600. The inner case 3500 may have a connection portion 3530 that engages with the socket 3600. The connection portion 3530 may have a threaded structure corresponding to the thread groove structure of the socket 3600. The inner case 3500 is nonconductive. Therefore, electrical short circuit between the circuit portion 3400 and the heat discharging body 3300 is prevented. For example, the inner case 3500 may be formed of plastic or resin.

The socket 3600 may be coupled to the inner case 3500. Specifically, the socket 3600 may be engaged with the connection portion 3530 of the inner case 3500. The socket 3600 may have the same structure as a conventional incandescent bulb. The circuit portion 3400 and the socket 3600 are electrically connected. The electrical connection between the circuit part 3400 and the socket 3600 may be connected via a wire. Accordingly, when external power is applied to the socket 3600, the external power may be transmitted to the circuit unit 3400. The socket 3600 may have a screw groove structure corresponding to the threaded structure of the connection portion 3550.

12 is an exploded perspective view 1200 of a backlight unit according to an embodiment. However, the backlight unit 1200 of FIG. 12 is an example of the illumination system, and the present invention is not limited thereto.

The backlight unit 1200 according to the embodiment includes a light guide plate 1210, a light emitting module unit 1240 for providing light to the light guide plate 1210, a reflection member 1220 below the light guide plate 1210, But the present invention is not limited thereto, and may include a bottom cover 1230 for housing the light emitting module unit 1210, the light emitting module unit 1240, and the reflecting member 1220.

The light guide plate 1210 serves to diffuse light into a surface light source. The light guide plate 1210 may be made of a transparent material such as acrylic resin such as PMMA (polymethyl methacrylate), polyethylene terephthalate (PET), polycarbonate (PC), cycloolefin copolymer (COC), and polyethylene naphthalate Resin. &Lt; / RTI >

The light emitting module part 1240 provides light to at least one side of the light guide plate 1210 and ultimately acts as a light source of a display device in which the backlight unit is installed.

The light emitting module 1240 may be in contact with the light guide plate 1210, but is not limited thereto. Specifically, the light emitting module 1240 includes a substrate 1242 and a plurality of light emitting device packages 200 mounted on the substrate 1242. The substrate 1242 is mounted on the light guide plate 1210, But is not limited to.

The substrate 1242 may be a printed circuit board (PCB) including a circuit pattern (not shown). However, the substrate 1242 may include not only a general PCB, but also a metal core PCB (MCPCB), a flexible PCB (FPCB), and the like.

The plurality of light emitting device packages 200 may be mounted on the substrate 1242 such that a light emitting surface on which the light is emitted is spaced apart from the light guiding plate 1210 by a predetermined distance.

The reflective member 1220 may be formed under the light guide plate 1210. The reflection member 1220 reflects the light incident on the lower surface of the light guide plate 1210 so as to face upward, thereby improving the brightness of the backlight unit. The reflective member 1220 may be formed of, for example, PET, PC, or PVC resin, but is not limited thereto.

The bottom cover 1230 may receive the light guide plate 1210, the light emitting module 1240, and the reflective member 1220. For this purpose, the bottom cover 1230 may be formed in a box shape having an opened upper surface, but the present invention is not limited thereto.

The bottom cover 1230 may be formed of a metal material or a resin material, and may be manufactured using a process such as press molding or extrusion molding.

The features, structures, effects and the like described in the embodiments are included in at least one embodiment and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects and the like illustrated in the embodiments can be combined and modified by other persons skilled in the art to which the embodiments belong. Accordingly, the contents of such combinations and modifications should be construed as being included in the scope of the embodiments.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention. It can be seen that the modification and application of branches are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that the present invention may be embodied in many other specific forms without departing from the spirit or essential characteristics thereof.

The substrate 105, the first conductivity type semiconductor layer 112,
The active layer 114, the second conductivity type semiconductor layer 116,
A through hole H, a first insulating layer 151, a second insulating layer 152,
The first pad electrode 141a, the first branched electrode 141b,
The second branched electrode 141c, the second electrode 142,
The first reflective layer 121, the second reflective layer 122,

Claims

Board;
A first conductive semiconductor layer on the substrate;
An active layer on the first conductive semiconductor layer;
A second conductive semiconductor layer on the active layer;
A plurality of through holes penetrating the second conductivity type semiconductor layer and a part of the active layer to expose a part of the first conductivity type semiconductor layer;
A first insulating layer formed on the second conductive semiconductor layer;
A first pad electrode formed on the first insulating layer;
A first branched electrode connected to the first pad electrode and formed on the first insulating layer;
A second branched electrode formed in the through hole and connected to the first branched electrode, the second branched electrode being in contact with the first conductive type semiconductor layer exposed by the through hole; And
And a second electrode on the second conductive semiconductor layer.

The method according to claim 1,
And a first reflective layer formed under the first pad electrode and the first branched electrode.

3. The method according to claim 1 or 2,
And a second insulating layer formed on a side wall of the through hole,
And the second branched electrode formed on a sidewall of the through hole is formed on the second insulating layer.

3. The method according to claim 1 or 2,
The first reflective layer
And a DBR (Distributed Bragg Reflector).

3. The method according to claim 1 or 2,
The second branched electrode
Wherein the first conductive semiconductor layer is in direct contact with only the region exposed by the through hole.

3. The method according to claim 1 or 2,
The size of the through hole through which the second branched electrode is formed
Wherein the width of the first branched electrode is larger than the width of the first branched electrode.

The method according to claim 6,
The size of the through hole through which the second branched electrode is formed
Wherein the width of the first branched electrode is three times or more the width of the first branched electrode.

The method according to claim 6,
The size of the through hole through which the second branched electrode is formed
And the size of the light emitting element is not more than half of the upper surface of the light emitting element.

3. The method according to claim 1 or 2,
The horizontal cross-section of the first reflective layer may be,
The first branched electrode, the second branched electrode, and the first pad electrode.

3. The method according to claim 1 or 2,
And a second reflective layer formed under the second electrode.