Hereinafter, embodiments will be described in detail with reference to the drawings.
FIG. 1 is a cross-sectional view showing a light emitting device having a barrier layer according to an embodiment, and FIG. 2 is a cross-sectional view illustrating an operation of a barrier layer according to an embodiment.
1, a light emitting device 100 according to the present invention includes a substrate 110, a buffer layer 191 formed on the substrate 110, a buffer layer 191 formed on the buffer layer 191, A second barrier layer 130 formed on the first barrier layer 120 and a first conductive semiconductor layer 130 formed on the second barrier layer 130. The first barrier layer 120 is formed on the first barrier layer 130, A current diffusion layer 193 and a strain control layer 195 sequentially formed on the first conductivity type semiconductor layer 140 such that an upper portion of the first conductivity type semiconductor layer 140 is exposed, An active layer 150 formed on the control layer 195, an electron blocking layer 197 formed on the active layer 150, a second conductive semiconductor layer 160 formed on the electron blocking layer 197, An ohmic layer 199 formed on the second conductive semiconductor layer 160, a first electrode 170 formed on the first conductive semiconductor layer 140, and a second electrode 170 formed on the ohmic layer 199 And a second electrode 180 formed on the second electrode 180.
The substrate 110 may be formed of a material having excellent thermal conductivity, or may be a conductive substrate or an insulating substrate. For example, the substrate 110 is a sapphire (Al 2 O 3), SiC, Si, GaAs, GaN, ZnO, GaP, InP, Ge, and Ga 2 0 3 May be used. The concavo-convex structure may be formed on the substrate 110, but the present invention is not limited thereto. In this embodiment, sapphire can be used as a substrate.
A buffer layer 191 may be formed on the substrate 110.
The buffer layer 191 relaxes the lattice mismatch between the material of the light emitting structure and the substrate 110. The buffer layer 191 may be formed of at least one of a group III-V compound semiconductor such as GaN, InGaN, AlGaN, and InAlGaN. Alternatively, the buffer layer 191 may be an undoped gallium nitride layer.
The buffer layer 191 may be formed of one or more layers, and the buffer layer 191 formed of a plurality of layers may be formed of different materials. For example, when the first buffer layer 191 is formed of two buffer layers 191, the first buffer layer may be an undoped gallium nitride layer and the second buffer layer may be an Al x Ga 1-x N (0 ? X? .
The barrier layers 120 and 130 may be formed on the buffer layer 191 according to an embodiment of the present invention.
The barrier layers 120 and 130 serve to prevent diffusion of dislocations and to relax strain on GaN. The barrier layers 120 and 130 may include a first barrier layer 120 and a second barrier layer 130.
The first barrier layer 120 may be formed of a material containing indium (In), and more specifically, may be formed of indium nitride (InN).
A plurality of voids 122 may be formed in the first barrier layer 120. The voids 122 effectively block the potential generated inside the light emitting device and refract or reflect the light generated in the active layer 150 to improve light efficiency.
The void 122 may be formed in a circular, hemispherical, or polygonal shape, and may be formed into a circular sphere shape in this embodiment.
The voids 122 may be formed to have different sizes and shapes within the first barrier layer 120 and may be irregularly formed inside the first barrier layer 120. [
The upper surface of the first barrier layer 120 may have irregularities. The irregularities may be formed over the entire upper surface of the first barrier layer 120 and irregularly formed on the upper surface of the first barrier layer 120. In other words, the irregularities may be formed in various shapes such as hemispheres, triangles, and polygons, and the irregularities of various shapes may be formed over the entire upper surface of the first barrier layer 120.
Alternatively, the upper surface of the first barrier layer 120 may be formed to have a flat surface in addition to the irregular relief shape. The thickness of the first barrier layer 120 may be 5 nm to 100 nm, and may be 20 nm to 80 nm.
The second barrier layer 130 may be formed on the first barrier layer 120.
The second barrier layer 130, like the first barrier layer 120, mitigates strain on the GaN layer due to lattice mismatch and difference in thermal expansion coefficient. For this, the second barrier layer 130 may be formed of a material containing indium (In), and more specifically, may be formed of a gallium nitride (InGaN) layer.
The second barrier layer 130 may be formed to be smaller than the thickness of the first barrier layer 120 and may be formed to be ½ to ⅓ of the thickness of the first barrier layer 120. The upper surface of the second barrier layer 130 may be formed to have irregular irregularities, or alternatively may be formed to have a flat surface.
2, when a dislocation d is generated in the light emitting device due to the difference in lattice constant between sapphire and GaN, the dislocation d is further reduced by the void 122 formed in the first barrier layer 120 So that it can not proceed to the upper part.
In addition, the void 122 formed in the first barrier layer 120 prevents diffusion of dislocations and reflects or refracts the light L generated in the active layer 150. Accordingly, it is possible to prevent the light L generated in the active layer 150 from propagating to the outside.
As described above, the void 122 according to the embodiment has the effect of further improving the light efficiency by reflecting the light toward the active layer 150 again.
Referring back to FIG. 1, a first conductivity type semiconductor layer 140 may be formed on the second barrier layer 130.
The first conductive semiconductor layer 140 may be formed of a compound semiconductor such as a Group 3-Group-5, Group-6, or Group-6 semiconductor, and may be doped with an n-type dopant. The N-type dopant may include, but not limited to, Si, Ge, Sn, Se, and Te.
Alternatively, the first conductive semiconductor layer 140 may have a composition formula of In x Al y Ga 1 -x- y N (0? X? 1, 0? Y? 1, 0? X + y? 1) Semiconductor material. The first conductive semiconductor layer 140 may be formed of one or more of GaN, InN, AlN, InGaN, AlGaN, InAlGaN, AlInN, AlGaAs, InGaAs, AlInGaAs, GaP, AlGaP, InGaP, AlInGaP and InP.
A current diffusion layer 193 may be formed on the first conductive semiconductor layer 140.
The current diffusion layer 193 may increase the light efficiency by improving the internal quantum efficiency and may be an undoped GaN layer.
Further, an electron injection layer (not shown) may be further formed on the current diffusion layer 193. The electron injection layer may be a conductive 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 ~ 3.0x10 19 atoms / cm 3.
A strain control layer 195 may be formed on the electron diffusing layer 193.
The strain control layer 195 effectively relaxes the stress caused by the lattice mismatch between the first conductive semiconductor layer 140 and the active layer 150. The strain control layer 195 may be formed of a multi-layer (multi-layer), for example, the strain control layer 175 is Al x In y Ga 1 -x- y N GaN and a plurality of pairs (pair) As shown in FIG.
The lattice constant of the strain control layer 195 may be greater than the lattice constant of the first conductive semiconductor layer 140 but less than the lattice constant of the active layer 150. Accordingly, the stress due to the difference in lattice constant between the active layer 150 and the first conductivity type semiconductor layer 140 can be minimized.
The active layer 150 may be formed on the strain control layer 195.
Electrons injected through the first conductive type semiconductor layer 140 and holes injected through the second conductive type semiconductor layer 160 to be formed later meet 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 150 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 150 may be formed of 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 150 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.
An electron blocking layer 197 may be formed on the active layer 150.
The electron blocking layer 197 functions as an electron blocking layer and a cladding layer of the active layer (MQW cladding), thereby improving the luminous efficiency. The electron blocking layer 197 may be formed of an Al x In y Ga (1-xy) N (0? X ? 1, 0? Y ? 1 ) semiconductor and is higher than the energy band gap of the active layer 150 An energy bandgap, and may be formed to a thickness of about 100 A to about 600 A, but the present invention is not limited thereto. Alternatively, the electron blocking layer 177 may be formed of a superlattice of Al z Ga (1-z) N / GaN (0? Z ? 1).
A second conductive semiconductor layer 160 may be formed on the electron blocking layer 197.
The first conductive semiconductor layer 160 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 conductivity type semiconductor layer 160 may be a semiconductor having a composition formula of In x Al y Ga 1 -x- y N (0? X? 1, 0? Y? 1, 0? X + ≪ / RTI > As the dopant of the second conductive semiconductor layer 160, Mg, Zn, Ca, Sr, Ba, or the like may be included.
The ohmic layer 199 may be formed on the second conductive semiconductor layer 160.
The ohmic layer 199 may be formed by stacking a single metal, a metal alloy, a metal oxide, or the like in multiple layers so as to efficiently perform carrier injection. For example, the ohmic layer 199 may be formed of a material having excellent electrical contact with the semiconductor. The ohmic layer 199 may be formed of indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO) IZO (indium gallium zinc oxide), IGTO (indium gallium tin oxide), AZO (aluminum zinc oxide), ATO (antimony tin oxide), GZO (gallium zinc oxide), IZON ), AgZO (Al-Ga ZnO), IGZO (In-Ga ZnO), ZnO, IrOx, RuOx, NiO, RuOx / ITO, Ni / IrOx / Au and Ni / IrOx / , At least one of Ti, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au and Hf.
A second electrode 180 is formed on the ohmic layer 199 and a first electrode 170 is formed on the exposed n-type semiconductor layer 140. Finally, the first electrode 170 and the second electrode 180 are connected to each other, thereby completing the fabrication of the light emitting device.
Hereinafter, a manufacturing process of the light emitting device according to the present invention will be described with reference to FIGS. 3 to 9. FIG. 3 to 9 are cross-sectional views illustrating a method of manufacturing a light emitting device according to an embodiment.
As shown in FIG. 3, when a sapphire substrate 110 is provided, a step of forming a buffer layer 191 on one surface of the substrate 110 is performed.
The buffer layer 191 may be formed by depositing GaN on the substrate 110 to a predetermined thickness by metal organic chemical vapor deposition (MOCVD). As the buffer layer 191, AIN and ZnO may be used in addition to GaN have. Of course, the buffer layer may be formed by chemical vapor deposition (CVD), molecular beam epitaxy (MBE), or sputtering in addition to MOCVD.
As shown in FIG. 4, when the buffer layer 191 is formed on the substrate 110, a step of forming the first barrier layer 120 on the buffer layer 191 is performed.
The first barrier layer 120 may be formed using indium (In), and an indium nitride (InN) layer may be formed by supplying ammonia (NH 3 ) gas to In. That is, when NH 3 is supplied to In, In reacts with N, and thus an indium nitride (InN) layer can be formed.
The first barrier layer 120 may be formed by MOCVD at a low temperature, for example, 500 ° C. to 800 ° C., and the first barrier layer may have a thickness ranging from 5 nm to 100 nm.
5, when the first barrier layer 120 is formed on the buffer layer 191, a step of forming the first conductive semiconductor layer 140 on the first barrier layer 120 is performed .
The first conductive semiconductor layer 140 may be formed by depositing GaN by MOCVD. Alternatively, the first conductive semiconductor layer 140 may be formed by depositing a Group 3-5 or Group 2-6 compound.
The first conductivity type semiconductor layer 140 is 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.
The first conductive semiconductor layer 140 can be processed at a high temperature, for example, between 1000 ° C. and 1200 ° C. As the deposition of the first conductivity type semiconductor layer 140 is performed at a high temperature, a part of In contained in the first barrier layer 120 moves to the lower portion of the first conductivity type semiconductor layer 140.
6, voids 122 are formed in a region where In is present in the first barrier layer 140 as a part of In rises and moves to the lower portion of the first conductivity type semiconductor layer 140 as shown in FIG. do. That is, the voids 122 are formed while the first conductive semiconductor layer 140 is deposited.
In addition, a part of In, which is moved to the lower portion of the first conductivity type semiconductor layer 140, reacts with the GaN of the first conductivity type semiconductor layer 140 to form the second barrier layer 130. Accordingly, the second barrier layer 130 may be formed of a gallium nitride (InGaN) material.
In addition, since the In is irregularly absorbed into the first conductivity type semiconductor layer 140 in different regions, the lower surface and the upper surface of the second barrier layer 130 have an irregular concavo-convex shape.
7, when the first conductivity type semiconductor layer 140 is formed on the second barrier layer 130, a current diffusion layer 193 and a strain control layer (not shown) are formed on the first conductivity type semiconductor layer 140 195, and the active layer 150 are sequentially formed.
The current diffusion layer 193 and the strain control layer 195 may be deposited to a predetermined thickness by MOCVD and an electron injection layer (not shown) may be further formed between the current diffusion layer 193 and the strain control layer 195 .
The active layer 150 is selectively supplied to a source of H 2 and / or TMGa (or TEGa), TNin, and TMAI at a predetermined growth temperature, for example, in a range of 700 to 900 degrees to form a well layer made of GaN or InGaN, , A barrier layer made of AlGaN, InGaN or InAlGaN can be formed.
8, when a current diffusion layer 193, a strain control layer 195, and an active layer 150 are sequentially stacked on the first conductive semiconductor layer 140, The blocking layer 197, the second conductive semiconductor layer 160, and the ohmic layer 199 are formed.
The electron blocking layer 197 may be formed by ion implantation into the second conductivity type semiconductor layer 160. For example, the electron blocking layer 197 may be formed of AlxInyGa (1-x-y) having an Al composition ranging from 1 to 30%.
The second conductivity type semiconductor layer 160 is formed by injecting biscyclopentadienyl magnesium (EtCp 2 Mg) {Mg (C 2 H 5 C 5 H 4 ) 2 } on the electron blocking layer 197 Accordingly, the second conductive semiconductor layer 160 may be formed of a p-type GaN layer. The ohmic layer 199 can be formed by depositing ITO.
9, when the ohmic layer 199 is formed on the second conductive semiconductor layer 160, a mesa etching process may be performed to expose a portion of the first conductive semiconductor layer 140 . A part of the ohmic layer 199, the second conductivity type semiconductor layer 160, the electron blocking layer 197, the active layer 150, the strain control layer 195 and the current diffusion layer 193 is removed, Type semiconductor layer 140 may be exposed.
The first electrode 170 may be formed on the first conductive semiconductor layer 140 and the second electrode 180 may be formed on the ohmic layer 199. [ So that the manufacturing process of the light emitting device according to the present invention can be completed.
10 is a cross-sectional view of a light emitting device package according to an embodiment. In the light emitting device package according to the embodiment, the light emitting device having the structure as described above may be mounted.
The light emitting device package 200 includes a package body portion 205, a third electrode layer 213 and a fourth electrode layer 214 disposed on the package body portion 205, A light emitting device 100 arranged to be electrically connected to the third electrode layer 213 and the fourth electrode layer 214 and a molding member 230 surrounding the light emitting device 100 are included.
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 disposed on the package body 205 or may be disposed 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 and the fourth electrode layer 214 through wires. However, the present invention is not limited thereto.
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.
11 to 13 are exploded perspective views illustrating embodiments of an illumination system including a light emitting device according to an embodiment.
11, the lighting apparatus according to the present invention 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, . 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 the light emitting device 100 or the light emitting device package 200 according to the present invention.
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 transparent so that the light source module 2200 is visible from the outside, and may be opaque. 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.
12, the lighting apparatus according to the present invention includes a cover 3100, a light source unit 3200, a heat sink 3300, a circuit unit 3400, an inner case 3500, and a socket 3600 can do. 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 a screw thread of the cover 3100 is engaged with a thread groove of the heat dissipating body 3300 so that the cover 3100 is coupled to the heat dissipating body 3300 by rotation of the cover 3100 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.
The light source portion 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 . ≪ / 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. 16, 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 can 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.
13, a backlight unit according to the present invention includes a light guide plate 1210, a light emitting module unit 1240 for providing light to the light guide plate 1210, a light guide plate 1210, A bottom cover 1230 for housing the light guide plate 1210, the light emitting module unit 1240 and the reflection member 1220 may be included in the lower portion of the bottom cover 1220. However, the present invention is not limited thereto.
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. ≪ / RTI >
The light emitting module 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 disposed.
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.
It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the following claims. It will be possible.
