KR20140041225A

KR20140041225A - Light emitting device

Info

Publication number: KR20140041225A
Application number: KR1020120108308A
Authority: KR
Inventors: 나종호
Original assignee: 엘지이노텍 주식회사
Priority date: 2012-09-27
Filing date: 2012-09-27
Publication date: 2014-04-04

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 first conductive semiconductor layer 112; An active layer 114 including a well layer and a barrier layer 114b on the first conductive semiconductor layer 112; A second conductive semiconductor layer 116 on the active layer 114, wherein the barrier layer 114b comprises: a first barrier layer 114b1 on the first conductive semiconductor layer; A second barrier layer 114b2 is disposed between the first barrier layer 114b1 and the second conductivity-type semiconductor layer 116. The first barrier layer 114b1 includes a GaN barrier layer 114bg and the And an Al _x Ga _(1-x) N barrier layer 114ba on the GaN barrier layer 114bg.

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.

Nitride semiconductors used in blue LEDs are subject to large stresses during growth due to different thermal expansion coefficients and lattice constants of the substrate and each growth layer.

In particular, this phenomenon breaks the uniformity of the entire wafer as the size of the substrate increases. For example, the low current characteristics and the wavelength distribution increase depending on the region, and as a result, the characteristics of the light emitting device chip also vary.

To solve this phenomenon, wafer carriers are designed to be convex as needed to reduce the effects of bowing during growth, but it is difficult to manufacture because it requires precision of tens of μm. In particular, since the state of bowing changes as each layer grows, bowing control in a particular layer which is problematic in the end is important.

Embodiments provide a light emitting device capable of improving overall wafer uniformity, a method of manufacturing the same, a light emitting device package, and an illumination system.

The light emitting device according to the embodiment includes a first conductive semiconductor layer 112; An active layer 114 including a well layer 114a and a barrier layer 114b on the first conductivity type semiconductor layer 112; A second conductive semiconductor layer 116 on the active layer 114, wherein the barrier layer 114b comprises: a first barrier layer 114b1 on the first conductive semiconductor layer; A second barrier layer 114b2 is disposed between the first barrier layer 114b1 and the second conductivity-type semiconductor layer 116. The first barrier layer 114b1 includes a GaN barrier layer 114bg and the And an Al _x Ga _(1-x) N barrier layer 114ba on the GaN barrier layer 114bg.

According to the light emitting device, the method of manufacturing the light emitting device, the light emitting device package, and the lighting system according to the embodiment, the wafer bowing is controlled in the growth stage of the quantum well structure which has the greatest influence on the distribution of the light emitting device characteristics. Wafer uniformity can be improved.

In addition, the embodiment can improve the yield by controlling the wafer bow (wafer bowing) generated during the growth of the large-area nitride compound LED structure.

1 is a cross-sectional view of a light emitting device according to an embodiment.
2A is a diagram illustrating a band diagram of a part of a light emitting device according to the first embodiment;
2B is an exemplary band diagram of a portion of a light emitting device according to the second embodiment;
Figure 3 is an illustration of a distribution picture of the brightness of the light emitting device according to the embodiment.
4 is a diagram illustrating a distribution of luminance according to chip emission wavelength (WD) of a light emitting device according to an embodiment;
5 is a cross-sectional view of a light emitting device package according to an embodiment.
6 to 8 are views showing the lighting apparatus according to the embodiment.
9 and 10 are views showing another example of the lighting apparatus according to the embodiment.
11 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 cross-sectional view of a light emitting device 100 according to an embodiment.

The light emitting device 100 according to the exemplary embodiment includes an active layer 114 including a first conductive semiconductor layer 112 and a well layer 114a and a barrier layer 114b on the first conductive semiconductor layer 112. And a second conductivity type semiconductor layer 116 on the active layer 114.

The first conductive semiconductor layer 112 and the active layer 114 and the second conductive semiconductor layer 116 may form a light emitting structure 110, And may be formed on a predetermined substrate 105.

The substrate 105 may be formed of a material having excellent thermal conductivity, or 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.

The embodiment includes a buffer layer 107 and / or an undoped semiconductor layer (not shown) on the substrate 105 to mitigate lattice mismatch between the material of the light emitting structure 110 and the substrate 105. The material of the buffer layer 107 may be formed of at least one of Group III-V compound semiconductors, for example, GaN, InN, AlN, InGaN, AlGaN, InAlGaN, and AlInN, but is not limited thereto.

In an exemplary embodiment, 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.

For example, the first conductive semiconductor layer 112 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. For example, 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, .

In an embodiment, a current diffusion layer (not shown), for example, an undoped GaN layer may be formed on the first conductive semiconductor layer 112.

In addition, in the embodiment, an electron injection layer 122, for example, a first conductivity type gallium nitride layer may be formed on the current diffusion layer to efficiently perform electron injection.

In addition, the embodiment is a strain control layer 124 on the electron injection layer 122, for example, In _y Al _x Ga _(1-xy) N (0≤x≤1, 0≤y≤1) / GaN The strain control layer 124 formed of, for example, may be formed to effectively alleviate stresses that are odd due to lattice mismatch between the first conductivity-type semiconductor layer 112 and the active layer 114.

In addition, as the strain control layer 124 is repeatedly stacked in at least six cycles having a composition of 1 In _{x 1} GaN, 2 In _x 2 GaN, and the like, more electrons are collected at a lower energy level of the active layer 114, and as a result, As a result, the probability of recombination of electrons and holes may be increased, thereby improving luminous efficiency.

Next, an active layer 114 is formed on the strain control layer 124.

In an embodiment, 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. have. 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 114a and the barrier layer 114b of the active layer 114 are formed of any one of InGaN / GaN, InGaN / InGaN, GaN / AlGaN, InAlGaN / GaN, GaAs (InGaAs) / AlGaAs, GaP (InGaP) But the present invention 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.

Embodiments provide a light emitting device, a method of manufacturing the same, a light emitting device package, and an illumination system capable of improving yield by improving overall wafer uniformity.

2 is a diagram illustrating a band diagram of a part of the light emitting device according to the first embodiment.

According to the light emitting device, the method of manufacturing the light emitting device, the light emitting device package and the lighting system according to the embodiment to solve the problem, wafer bowing in the growth stage of the quantum well structure that has the greatest effect on the distribution of the light emitting device characteristics By controlling this, the overall wafer uniformity can be improved.

Through this, according to the embodiment, it is possible to increase the overall uniformity by controlling the wafer bowing generated during the growth of the large-area compound LED structure.

In order to achieve the above effect, the barrier layer 114b of the first embodiment may include a first barrier layer 114b1, a first barrier layer 114b1, and a second conductivity type semiconductor layer on the first conductive semiconductor layer. A second barrier layer 114b2 between 116, the first barrier layer 114b1 being an Al _x Ga _(1-x) N barrier on the GaN barrier layer 114bg and the GaN barrier layer 114bg. Layer 114ba.

The GaN barrier layer 114bg may include a plurality of layers, and an Al _x Ga _(1-x) N barrier layer 114ba may be interposed between the GaN barrier layers 114bg.

The bandgap energy of the GaN barrier layer 114bg may be smaller than the bandgap energy of the Al _x Ga _(1-x) N barrier layer 114ba.

The first barrier layer 114b1 including the Al _x Ga _(1-x) N barrier layer 114ba is closer to the first conductivity type semiconductor layer 112 than the second conductivity type semiconductor layer 116. Can be deployed.

In an embodiment, the concentration x of Al in the Al _x Ga _(1-x) N barrier layer 114ba may be 0 <x <0.3. According to the embodiment, the Al is included (0 <x) in the Al _x Ga _(1-x) N barrier layer 114ba to enable wafer bowing control, and when the Al concentration (x) is 0.3 or more, the barrier may be used. The height of the VANGAP energy level in the M3 is too high, which may interfere with the injection of electrons from the bottom. Accordingly, the concentration x of Al in the Al _x Ga _(1-x) N barrier layer 114ba is appropriately 0 <x <0.3.

In addition, in the embodiment, the Al _x Ga _(1-x) N barrier layer 114ba may be doped with an n-type element. For example, Si is doped in the Al _x Ga _(1-x) N barrier layer 114ba, and the doping concentration of the Si element is 9 × 10 ¹⁷ atoms / cm ^3. To 3 × 10 ¹⁸ atoms / cm ³ .

According to the embodiment, the Al _x Ga _(1-x) N barrier layer 114ba must also serve as an electron injection layer, and in particular, the energy barrier of the Al _x Ga _(1-x) N barrier layer 114ba is a GaN barrier. Since it is higher than (114 bg), the Si doping may be 9 × 10 ¹⁷ atoms / cm ³ or more for efficient injection of electrons. On the other hand, if the doping concentration of the n-type element is too high, there is a high possibility of recombination only at the very last part of the emission layer even if there are too many electrons in terms of balance between electrons and holes, and the film quality may be poor, so the n-type element is 3 ×. It may be doped up to 10 ¹⁸ atoms / cm ³ .

In addition, in the embodiment, the Al _x Ga _(1-x) N barrier layer 114ba may have a thickness of 6 nm or less. In addition, the first barrier layer 114b1 including the Al _x Ga _(1-x) N barrier layer 114ba may have a thickness of 18 nm or less. For example, the first barrier layer 114b1 may be an InGaN / AlGaN / InGaN multi-barrier and may not exceed 18 nm in total.

In an embodiment, the barrier effect due to the insertion of the Al _x Ga _(1-x) N barrier layer 114ba may depend on the bandgap energy height and the layer thickness. However, even if the height of the bandgap energy level is too thick, electron injection may be difficult, so doping of n-type elements in the range of 9 × 10 ¹⁷ atoms / cm ³ to 3 × 10 ¹⁸ atoms / cm ³ is necessary.

In addition, in the embodiment, in order to control the strain (strain control), the strain must be sufficiently received in the Al _x Ga _(1-x) N barrier layer 114ba, but if it is too thick, the strain is released. Since disappears, a thickness of about 1 nm to 6 nm or less is appropriate. Further, according to the embodiment, the appropriate thickness of the Al _x Ga _(1-x) N barrier layer 114ba may be 1 nm to 3 nm, but is not limited thereto.

In addition, in the embodiment, the Al _x Ga _(1-x) N barrier layer 114ba having a thickness less than half of the total thickness of the single first barrier layer 114b1 may be suitable for controlling wafer warpage. .

3 is a photograph illustrating distribution of brightness of a light emitting device according to an embodiment.

FIG. 3 is mapping data obtained by capturing the brightness of each small chip in a speed mode in a wafer state. It is also distributed in a wafer due to the influence of strain during growth, and the influence and the characteristics of each position can be grasped.

In Figure 3 (c) is a reference example of the intensity (IV) according to the color, (a) is a photograph of the intensity distribution of the wafer in the manufacturing method of the light emitting device according to the prior art, (b) is a light emitting device according to the embodiment In the manufacturing method of the photometric distribution of the wafer.

4 is a diagram illustrating a distribution of luminance according to chip emission wavelength (WD) of a light emitting device according to an embodiment. In FIG. 4 the x axis is the dominant wavelength and the y axis is the luminosity.

Observing the drawings of FIGS. 3 and 4 together, it can be seen that the light intensity is low on the long wavelength side (for example, about 450 nm or more) as shown in FIGS. 3A and 4R. For example, the effect of bowing is to have a large black scatter and a large drop of light.

On the other hand, when the embodiment is applied it can be seen that the dispersion is reduced when the improved by adjusting the wafer bowing (bowing) to increase the average brightness. For example, even in the long wavelength side (for example, about 450 nm or more) as shown in FIGS. 3 (b) and 4 (e), the area of the luminance IV is less than 98 (mV) almost disappears and the luminance distribution of the chip is very uniform. Done.

2B is a diagram illustrating a band diagram of a part of the light emitting device according to the second embodiment.

The second embodiment can employ the technical features of the first embodiment.

In the second exemplary embodiment, the well layer 114a may include a first well layer 114a1, a first well layer 114a1, and a second conductive semiconductor layer on the first conductive semiconductor layer 112. A second well layer 114a2 may be disposed between the layers 116, and the first well layer 114a1 may include an Al _x Ga _(1-x) N layer 114c.

The Al _x Ga _(1-x) N layer 114c of the first well layer 114a1 may have the same composition and thickness as the Al _x Ga _(1-x) N barrier layer 114ba, but is not limited thereto. It is not.

The first well layer 114a1 may be a well layer closest to the first conductivity type semiconductor layer 112.

In general, the mobility of holes among the carriers is low, so that the well layer 114d closest to the first conductivity-type semiconductor layer 112 contributes little to light emission.

Accordingly, the embodiment introduces an Al _x Ga _(1-x) N layer 114c into the first well layer 114a1 that is included in the active layer and hardly contributes to light emission. By improving the bowing the brightness can be increased.

According to the light emitting device and the manufacturing method according to the embodiment, the wafer uniformity can be improved by controlling the wafer bowing in the growth stage of the quantum well structure which has the greatest influence on the distribution of the light emitting device characteristics. .

Next, the following process is demonstrated with reference to FIG.

In an embodiment, the electron blocking layer 126 is formed on the active layer 114 to improve the luminous efficiency by acting as electron blocking and cladding of the active layer.

In an embodiment, the electron blocking layer 126 may be formed of Al _x In _y Ga _(1-xy) N (0 ≦ _x ≦ 1,0 ≦ _y ≦ 1) based semiconductor, and the energy band of the active layer 114 may be It may have a higher energy band gap than the gap, and may be formed to a thickness of about 100 kPa to about 600 kPa, but is not limited thereto.

In addition, the electron blocking layer 126 may be formed of a superlattice made of Al _z Ga _(1-z) N / GaN (0? _Z ? 1), but is not limited thereto.

In addition, the electron blocking layer 126 may efficiently block electrons overflowed by ion implantation into a p-type and increase hole injection efficiency. For example, the electron blocking layer 126 may be formed by implanting Mg in a concentration range of about 10 ¹⁸ to 10 ²⁰ / cm ³ to effectively block electrons that overflow and increase the hole injection efficiency.

The second conductivity type semiconductor layer 116 may be formed on the electron blocking layer 126. 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 p-type dopants.

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.

Next, in the embodiment, the light-transmitting electrode 130 is formed on the second conductive type semiconductor layer 116, and the light-transmitting electrode 130 may include a light-transmitting ohmic layer, A single metal, a metal alloy, a metal oxide, or the like may be laminated in multiple layers.

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 ZnO, IrOx, RuOx, and NiO, and is not limited to such a material.

The second conductivity type semiconductor layer 116 and the active layer 114 are partially removed to expose the first conductivity type semiconductor layer 112 and then the active layer 114 is formed on the light- And a first electrode 131 is formed on the exposed first conductive semiconductor layer 112. The first electrode 131 is formed on the exposed first conductive semiconductor layer 112,

5 is a view illustrating a light emitting device package 200 having 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.

6 to 8 are views showing a lighting apparatus according to an embodiment.

FIG. 6 is a perspective view of the illumination device according to the embodiment viewed from above, FIG. 7 is a perspective view of the illumination device shown in FIG. 6, and FIG. 8 is an exploded perspective view of the illumination device shown in FIG.

6 to 8, the lighting apparatus 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.

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

FIG. 9 is a perspective view of a lighting apparatus according to the embodiment, and FIG. 10 is an exploded perspective view of the lighting apparatus shown in FIG.

9 and 10, the illumination 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.

10, 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. 10, 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.

11 is an exploded perspective view 1200 of a backlight unit according to an embodiment. However, the backlight unit 1200 of FIG. 11 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 first conductive semiconductor layer 112,
A well layer 114a, a barrier layer 114b, an active layer 114;
A second conductivity type semiconductor layer 116;
First barrier layer 114b1 and second barrier layer 114b2
GaN barrier layer 114bg, Al _x Ga _(1-x) N barrier layer 114ba
First well layer 114a1, Second well layer 114a2
Al _x Ga _(1-x) N layer 114c

Claims

A first conductive semiconductor layer;
An active layer including a well layer and a barrier layer on the first conductivity type semiconductor layer;
And a second conductive semiconductor layer on the active layer,
The barrier layer,
A first barrier layer on the first conductive semiconductor layer;
A second barrier layer between the first barrier layer and the second conductive semiconductor layer,
The first barrier layer,
A light emitting device comprising a GaN barrier layer and an Al _x Ga _(1-x) N barrier layer on the GaN barrier layer.

The method according to claim 1,
The GaN barrier layer is provided with a plurality of layers,
A light emitting device in which an Al _x Ga _(1-x) N barrier layer is interposed between the plurality of GaN barrier layers.

The method according to claim 1,
The first barrier layer including the Al _x Ga _(1-x) N barrier layer is
The light emitting device disposed adjacent to the first conductive semiconductor layer rather than the second conductive semiconductor layer.

The method according to claim 1,
In the Al _x Ga _(1-x) N barrier layer,
The concentration (x) of Al is 0 <x <0.3.

The method according to claim 1,
The Al _x Ga _(1-x) N barrier layer is
A light emitting device doped with an n-type element.

6. The method of claim 5,
In the Al _x Ga _(1-x) N barrier layer
Si element is doped, and the doping concentration of the Si element is
9 × 10 ¹⁷ atoms / cm ³ To 3 × 10 ¹⁸ atoms / cm ³ Phosphorescent light emitting element.

The method according to claim 1,
The Al _x Ga _(1-x) N barrier layer is
A light emitting element having a thickness of 6 nm or less.

8. The method of claim 7,
The first barrier layer including the Al _x Ga _(1-x) N barrier layer is
A light emitting device having a thickness of 18 nm or less.

The method according to claim 1,
The Al _x Ga _(1-x) N barrier layer is
A light emitting device having a thickness of less than half of the total thickness of a single first barrier layer.

The method according to claim 1,
The well layer,
A first well layer on the first conductive semiconductor layer;
A second well layer between the first well layer and the second conductivity type semiconductor layer,
The first well layer is
A light emitting device comprising Al _x Ga _(1-x) N layer.

11. The method of claim 10,
Al _x Ga _(1-x) N layer of the first well layer
A light emitting device having the same composition and thickness as the Al _x Ga _(1-x) N barrier layer.

11. The method of claim 10,
And the first well layer is a well layer closest to the first conductive semiconductor layer.