KR102019497B1

KR102019497B1 - Light emitting device

Info

Publication number: KR102019497B1
Application number: KR1020120041073A
Authority: KR
Inventors: 박범두; 성영운; 김민석
Original assignee: 엘지이노텍 주식회사
Priority date: 2012-04-19
Filing date: 2012-04-19
Publication date: 2019-09-06
Also published as: KR20130118122A

Abstract

In order to increase the luminous efficiency, the light emitting device according to the embodiment includes a light emitting structure layer; A first layer disposed on the light emitting structure layer and comprising a light transmitting metal; A second layer disposed on the first layer and comprising a reflective metal; A fourth layer disposed on the second layer and including a wire bonding region; And a third layer positioned between the second layer and the fourth layer and having a conductivity that physically couples the second layer and the fourth layer.

Description

Light emitting device

The embodiment relates to a light emitting device.

LED (Light Emitting Diode) is a device that converts an electric signal into infrared, visible or light form by using the characteristics of compound semiconductor.It is used in home appliances, remote control, electronic signs, indicators, various automation devices, etc. LED's usage area is getting wider. LED has advantages of low power consumption, semi-permanent life, fast response speed, safety and environmental friendliness compared to conventional light sources such as fluorescent and incandescent lamps.

In general, miniaturized LEDs are made of a surface mount device type for direct mounting on a printed circuit board (PCB) board. Accordingly, LED lamps, which are used as display elements, are also being developed as surface mount device types. . Such a surface mounting element can replace a conventional simple lighting lamp, which is used as a lighting display for various colors, a character display and an image display.

LED semiconductors are grown through heterogeneous substrates such as sapphire or silicon carbide (SiC) having a hexagonal structure through metal organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE).

The LED generates light by recombination of holes provided in the p-type semiconductor layer and electrons provided in the n-type semiconductor layer in the active layer. In the LED, improving the probability of recombination of holes and electrons in the active layer is an important issue for improving the light efficiency.

The embodiment provides a light emitting device having improved luminous efficiency.

A light emitting device according to an embodiment of the present invention, the light emitting structure layer; A first layer disposed on the light emitting structure layer, the first layer comprising a light transmitting metal; A second layer disposed on the first layer and comprising a reflective metal; A fourth layer disposed on the second layer and including a wire bonding region; It may include a third layer positioned between the second layer and the fourth layer and having a conductivity that physically couples the second layer and the fourth layer.

The light emitting device according to the embodiment of the present invention improves the light efficiency by forming a second layer having a thickness thinner than a fourth layer below the existing pad layer and forming a first layer having a thickness thinner than the third layer. can do.

According to another embodiment of the present invention, light efficiency may be further improved by forming holes or patterns in the first layer.

1 is a cross-sectional view showing the structure of a light emitting device according to the embodiment.
2A is a cross-sectional view showing the structure of a light emitting device according to the embodiment.
2B is a bottom view illustrating the pad layer of the light emitting device according to the embodiment.
3A is a cross-sectional view showing the structure of a light emitting device according to the embodiment.
3B is a bottom view illustrating the pad layer of the light emitting device according to the embodiment.
4A is a perspective view illustrating a light emitting device package including a light emitting device of an embodiment.
4B is a cross-sectional view showing a light emitting device package including the light emitting device of the embodiment.
5A is a perspective view illustrating a lighting device including a light emitting device module according to an embodiment.
5B is a cross-sectional view of a lighting apparatus including a light emitting device module according to an embodiment.
6 is an exploded perspective view illustrating a backlight unit including a light emitting device module according to an embodiment.
7 is an exploded perspective view illustrating a backlight unit including a light emitting device module according to an embodiment.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various different forms, only the embodiments are to make the disclosure of the present invention complete, and common knowledge in the art It is provided to fully inform the person having the scope of the invention, which is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

The spatially relative terms " below ", " beneath ", " lower ", " above ", " upper " It may be used to easily describe the correlation of a device or components with other devices or components. Spatially relative terms are to be understood as including terms in different directions of the device in use or operation in addition to the directions shown in the figures. For example, when flipping a device shown in the figure, a device described as "below" or "beneath" of another device may be placed "above" of another device. Thus, the exemplary term "below" can encompass both an orientation of above and below. The device can also be oriented in other directions, so that spatially relative terms can be interpreted according to orientation.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. In this specification, the singular also includes the plural unless specifically stated otherwise in the phrase. As used herein, “comprises” and / or “comprising” refers to the presence of one or more other components, steps, operations and / or elements. Or does not exclude additions.

Unless otherwise defined, all terms (including technical and scientific terms) used in the present specification may be used in a sense that can be commonly understood by those skilled in the art. In addition, the terms defined in the commonly used dictionaries are not ideally or excessively interpreted unless they are specifically defined clearly.

In the drawings, the thickness or size of each layer is exaggerated, omitted, or schematically illustrated for convenience and clarity of description. In addition, the size and area of each component does not necessarily reflect the actual size or area.

In addition, the angle and direction mentioned in the process of describing the structure of the light emitting device in the embodiment are based on those described in the drawings. In the description of the structure constituting the light emitting device in the specification, if the reference point and the positional relationship with respect to the angle is not clearly mentioned, reference is made to related drawings.

Hereinafter, exemplary embodiments will be described in more detail with reference to the accompanying drawings.

1 is a cross-sectional view showing the structure of a light emitting device 1000 according to an embodiment of the present invention.

Referring to FIG. 1, the light emitting device 1000 according to the embodiment may include an omnidirectional reflector layer 20 and an ODR layer disposed on the substrate 10 and reflecting light incident at any angle. 20 is disposed on the p-omic layer 30 and the p-omic layer 30 to make an ohmic contact with the electrode, and a wavelength larger than a specific value according to the bandgap energy. The first conductive layer 52, the active layer 54, the second semiconductor layer 56, and the second semiconductor layer 56 disposed on the transparent conductive layer 40 and the transparent conductive layer 40 that do not absorb and transmit. It is disposed on the reflective layer 60 together with the reflective layer 60 disposed on the reflective layer 60, the ohmic layer 70 disposed on the reflective layer 60, and the ohmic layer 70 so as not to focus current under the pad layer 100. The pad layer 100 is disposed on the current blocking layer 80 and the ohmic layer 70.

The substrate 10 may be formed of a semiconductor material according to an embodiment, for example, silicon (Si), germanium (Ge), gallium arsenide (GaAs), zinc oxide (ZnO), silicon carbide (SiC), It may be implemented as a carrier wafer such as silicon germanium (SiGe), gallium nitride (GaN), gallium (III) oxide (Ga ₂ O ₃ ). The substrate 10 may be formed of a conductive material. According to the embodiment, the metal may be formed of, for example, gold (Au), nickel (Ni), tungsten (W), molybdenum (Mo), copper (Cu), aluminum (Al), tantalum (Ta), or silver. It may be formed of any one selected from (Ag), platinum (Pt), chromium (Cr) or formed of two or more alloys, and may be formed by stacking two or more of the above materials. When the substrate 10 is formed of a metal, it is possible to facilitate the emission of heat generated from the light emitting device to improve the thermal stability of the light emitting device.

The substrate 10 may include a patterned substrate (PSS) structure on an upper surface of the substrate 10 to increase light extraction efficiency, but is not limited thereto. The substrate 10 may improve the thermal stability of the light emitting device 1000 by facilitating the emission of heat generated from the light emitting device 1000.

The substrate 10 may be disposed under the ODR layer 20, but is not limited thereto. The substrate 10 may be disposed above the first electrode 90 in the case of the vertical LED.

Silver (Ag) is mainly used for the ODR layer 20 to reflect light, but is not limited thereto. The ODR layer 20 may be formed of a metal having high reflectance. The ODR layer 20 can reflect incoming light at any angle. The ODR layer 20 can be patterned structurally or insert a transparent layer into the interlayer to further improve the reflectance of this layer. In the ODR layer 20, indium tin oxide (ITO) may be inserted on silver (Ag) to improve reflectance according to an incident angle.

The ODR layer 20 may be disposed on the substrate 10, but is not limited thereto. The ODR layer 20 may be disposed under the p-ohmic layer 30, but is not limited thereto.

The p-omic layer 30 may be formed by stacking a single metal, a metal alloy, a metal oxide, or the like in multiple layers so as to efficiently inject holes. For example, the p-omic layer 30 may include ITO, IZO (In-ZnO), GZO (Ga-ZnO), AZO (Al-ZnO), IGZO (In-Ga-ZnO), IrOx, RuOx, RuOx / At least one of ITO, Ni / IrOx / Au, alc Ni / IrOx / Au / ITO, Ni, Ag, and the like may be formed, but is not limited thereto.

The p-omic layer 30 is for achieving good ohmic contact with the second semiconductor layer 56. The P-ohmic layer 30 may be disposed under the second semiconductor layer 56, but is not limited thereto.

The transparent conductive layer 40 serves as a conductive layer. The transparent conductive layer 40 may be made of a material such as GaP, but is not limited thereto.

The transparent conductive layer 40 may be passed through without being absorbed in the case of a wavelength larger than the wavelength according to the band gap energy. For example, when the bandgap energy is 2.24 eV, the transparent conductive layer 40 can transmit a wavelength of 553 nm or more without absorbing it.

The transparent conductive layer 40 may be disposed on the p-ohmic layer 30, but is not limited thereto. The transparent conductive layer 40 may be disposed under the light emitting structure layer 50, but is not limited thereto.

The light emitting structure layer 50 includes a first semiconductor layer 52, an active layer 54, and a second semiconductor layer 56.

The first semiconductor layer 52 may be disposed on the substrate 10. The first semiconductor layer 52 may be disposed on a buffer layer (not shown) to match the difference in lattice constant with the substrate 10, but is not limited thereto. The first semiconductor layer 52 may be grown on the substrate 10, but is not limited to the horizontal light emitting device but may be applied to the vertical light emitting device.

The first semiconductor layer 52 may be implemented as an n-type semiconductor layer, and the n-type semiconductor layer may be, for example, In _x Al _y Ga _1-xy N (0 = x = 1, 0 = y = 1, 0 = a semiconductor material having a compositional formula of x + y = 1), for example, gallium nitride (GaN), aluminum nitride (AlN), aluminum gallium nitride (AlGaN), indium gallium nitride (InGaN), indium nitride (InNN), InAlGaN, AlInN or the like. For example, the first semiconductor layer 52 may be doped with n-type dopants such as silicon (Si), germanium (Ge), tin (Sn), selenium (Se), and tellurium (Te).

The active layer 54 may be disposed on the first semiconductor layer 52. The active layer 54 may be disposed between the second semiconductor layer 56 and the first semiconductor layer 52.

The active layer 54 may be formed of a semiconductor material. The active layer 54 may be formed in a single or multiple well structure or the like using a compound semiconductor material of group III-Group 5 elements. The active layer 54 may be formed of a nitride semiconductor. For example, the active layer 54 may include gallium nitride (GaN), indium gallium nitride (InGaN), indium gallium nitride (InAlGaN), or the like.

The second semiconductor layer 56 may be disposed on the active layer 54. The second semiconductor layer 56 may be implemented as a p-type semiconductor layer doped with a p-type dopant. The second semiconductor layer 56 is a semiconductor material having a compositional formula of In _x Al _y Ga _1-xy N (0 = x = 1, 0 = y = 1, 0 = x + y = 1), for example, GaN ( Gallium nitride), aluminum nitride (AlN), aluminum gallium nitride (AlGaN), indium gallium nitride (InGaN), indium nitride (InN), InAlGaN, AlInN, etc., and magnesium (Mg), zinc (Zn), calcium ( P-type dopants such as Ca), strontium (Sr), and barium (Ba) may be doped.

The first semiconductor layer 52, the active layer 54, and the second semiconductor layer 56 may include, for example, a metal organic chemical vapor deposition (MOCVD), a chemical vapor deposition (CVD), Plasma-Enhanced Chemical Vapor Deposition (PECVD), Molecular Beam Epitaxy (MBE), Hydride Vapor Phase Epitaxy (HVPE), etc. It is not limited to.

The doping concentrations of the conductive dopants in the first semiconductor layer 52 and the second semiconductor layer 56 may be formed uniformly or non-uniformly, but are not limited thereto.

The reflective layer 60 may be made of a metal layer including Al, Ag, or an alloy containing Al or Ag. The reflective layer 60 may be formed of aluminum, silver, or the like to effectively reflect light generated from the active layer 54.

The reflective layer 60 may be disposed on the light emitting structure layer 50, but is not limited thereto. The reflective layer 60 may be disposed under the ohmic layer 70, but is not limited thereto.

The ohmic layer 70 may be formed by stacking a single metal, a metal alloy, a metal oxide, or the like in multiple layers so as to efficiently inject holes. The ohmic layer 70 may be formed of, for example, ITO, IZO (In-ZnO), GZO (Ga-ZnO), AZO (Al-ZnO), IGZO (In-Ga-ZnO), IrOx, RuOx, RuOx / ITO, Ni. / IrOx / Au, alc Ni / IrOx / Au / ITO, Ni, and Ag, and may be formed, including, but not limited to, such materials.

The ohmic layer 70 may be disposed on the reflective layer 60, but is not limited thereto. The ohmic layer 70 may be disposed under the pad layer 100, but is not limited thereto.

When the current is concentrated at the bottom of the pad layer 100, the current blocking layer 80 may prevent electrons from being excited by the multi quantum wells and thus may not be emitted to the outside and thus may be lost.

The current blocking layer 80 may be disposed under the pad layer 100, but is not limited thereto. The current blocking layer 80 may be disposed on the reflective layer 60, but is not limited thereto.

Referring to FIG. 1, the pad layer 100 may be formed of a fourth layer 110, a third layer 120, a second layer 130, and a first layer 140. The first layer 140 may be disposed on the ohmic layer 70.

The fourth layer 110 may be formed to a thickness that can withstand thermal stress and pressure during wire bonding. The fourth layer 110 may have a thickness such that the wires are not spaced apart from the LEDs. If the fourth layer 110 does not have a predetermined thickness, it is difficult to withstand thermal stress and pressure during wire bonding, which may cause reliability problems. If the fourth layer 110 does not have a predetermined thickness, the wires may be spaced apart from the LED, thereby causing a problem of reliability. The fourth layer 110 may have a thickness of 1 μm or more for bonding wires to the pad metal and injecting current from the outside, and have a thickness of 2 μm or more to withstand thermal stress and pressure during wire bonding. Can be. Although the thickness of the fourth layer 110 may be thicker, the price of the material constituting the fourth layer 110 may increase in proportion to the thickness, so that the fourth layer 110 may be smaller than 500 μm to reduce cost.

The third layer 120 may be formed to a thickness such that the metal of the fourth layer 110 does not reach the second layer 130. The third layer 120 may be formed to a thickness that can improve the physical and electrical coupling force between the fourth layer 110 and the LED. The third layer 120 may be thicker as the thickness of the fourth layer 110 becomes thicker. The third layer 120 may have a thickness of 20 nm or more and 1000 nm or less according to the thickness of the fourth layer, and may have a thickness of 50 nm or more and 100 nm or less in consideration of the bonding force.

The second layer 130 may be formed to be thinner than the fourth layer 110. The second layer 130 may have a thickness such that the light transmitted through the first layer 140 may be sufficiently reflected. The second layer 130 should be thick enough to efficiently reflect the light transmitted through the first layer 140 again. If the thickness of the second layer 130 is thick, the thickness of the first layer 140 should be thicker to prevent the metal constituting the second layer 130 from diffusing into the ohmic layer 70. The second layer 130 may be formed to a thickness of 2 nm or more and 100 nm or less, and may be formed to a thickness of 5 nm or more and 30 nm or less in order to prevent diffusion of the ohmic layer.

The first layer 140 may be formed to have a thickness thinner than that of the third layer 120. The first layer 140 may be formed to a thickness to improve the physical coupling force and the electrical coupling force of the second layer 130 and the LED. The first layer 140 may be formed to a thickness that can absorb the incoming light to a minimum. According to the table below, the first layer 140 may have a transmittance of less than 1% when the thickness is 100 nm, and when the thickness is 1 nm, the transmittance may be 90% or more. The first layer 140 may be formed to a thickness of 0.1 nm or more and 20 nm or less, and may be formed to a thickness of 1 nm or more and 10 nm or less in consideration of transmittance.

Since the fourth layer 110 to the first layer 140 are diffused with each other over time, the constituent materials may be mixed with each other, so that it may be difficult to clearly measure the thickness. The thickness of the fourth layer 110 to the first layer 140 is not limited to the thickness value, but may be slightly different in thickness due to diffusion between atoms.

The fourth layer 110 may be formed of a metal having high reflectance. The fourth layer 110 may be formed of a metal having low resistance and high stability for wire bonding. The fourth layer 110 may be formed of at least one of gold (Au), silver (Ag), platinum (Pt), copper (Cu), and alloys thereof.

The third layer 120 may be formed of a metal to improve the physical and electrical coupling force between the fourth layer 110 and the second layer 130. The third layer 120 may be made of a metal to prevent the material of the fourth layer 110 from diffusing and reaching the second layer 130. The third layer 120 may be formed of at least one of titanium (Ti), nickel (Ni), chromium (Cr), and alloys thereof.

The second layer 130 may be made of the same metal as the fourth layer 110. In this case, it may be formed using the same deposition equipment, but there may be advantages in the process, but is not limited thereto. The second layer 130 may be made of a metal having high reflectance. Since the second layer 130 needs to reflect light incident from the first layer 140, the metal having a high reflectance is more effective for improving light efficiency and may be formed of a metal having a reflectance of 30% or more. The second layer 130 has only the fourth layer 110 and the third layer 120 when the reflectance falls below 30%, and the second layer 130 has no second layer 130 and the first layer 140. Although the light efficiency may not show a big difference, the reflectance is not limited thereto.

The first layer 140 may be formed of a metal for increasing the adhesion between the second layer 130 and the ohmic layer 70. The first layer 140 may prevent peeling due to a different thermal expansion coefficient between the second layer 130 and the semiconductor material. The first layer 140 may be formed so that diffusion of the second layer 130 does not reach the ohmic layer 70.

Another embodiment of the present invention will be described with reference to FIGS. 2A, 2B and 3A, 3B. Hereinafter, the description of the same configuration as the above-described embodiment will be omitted, and only the changed configuration will be described.

2A and 2B, holes 142 may be formed in the first layer 140. Since the holes 142 may not absorb light, the absorption of the first layer 140 may be decreased to increase the reflectance of the second layer 130. The hole 142 may be formed to a size such that the adhesion between the second layer 130 and the ohmic layer 70 can be maintained. The hole 142 may be formed to a size such that the second layer 130 does not diffuse to the ohmic layer 70. The hole 142 may have the longest side or diameter of the hole 142 or less than 1/2 of the diameter of the pad layer 100, but is not limited thereto. In the hole 142, when the size of the hole 142 is larger than 1/2 of the diameter of the pad layer 100, the adhesive force may be greatly decreased. The hole 142 may be difficult to form with a size of 5 μm or less in the current process, but is not limited thereto. The hole 142 may have a size larger than 5 μm and smaller than 1/2 of the diameter of the pad layer 100.

3A and 3B, a pattern may be formed in the first layer 140. When the pattern is formed in the first layer 140, the same effect as forming holes 142 may be obtained. The pattern can reduce the absorption in the first layer 140. 4B is one embodiment of a pattern, but the pattern is not limited thereto. Patterns may be formed in the first layer 140 through various processes.

The patterning process may be electron beam patterning useful for nano patterning, the etching process may be performed by wet etching or electron beam lithography, and the deposition process may be performed by electron beam evaporation.

4A is a perspective view illustrating a light emitting device package 300 according to an embodiment of the present invention, and FIG. 4B is a cross-sectional view illustrating a cross section of the light emitting device package 300 according to another embodiment.

4A and 4B, the light emitting device package 300 according to the embodiment includes a body 310 having a cavity formed therein, and first and second electrodes 340 and 350 mounted on the body 310. The light emitting device 320 electrically connected to the two electrodes and the encapsulant 330 formed in the cavity may be included, and the encapsulant 330 may include a phosphor (not shown).

The body 310 is made of a resin material such as polyphthalamide (PPA), silicon (Si), aluminum (Al), aluminum nitride (AlN), photosensitive glass (PSG), polyamide 9T (PA9T) ), Neo geotactic polystyrene (SPS), a metal material, sapphire (Al ₂ O ₃ ), beryllium oxide (BeO), a printed circuit board (PCB, Printed Circuit Board) may be formed of at least one. The body 310 may be formed by injection molding, etching, or the like, but is not limited thereto.

The inner surface of the body 310 may be formed inclined surface. The reflection angle of the light emitted from the light emitting device 320 may vary according to the angle of the inclined surface, and thus the directivity angle of the light emitted to the outside may be adjusted.

The shape of the cavity formed in the body 310 as viewed from above may be circular, rectangular, polygonal, elliptical, or the like, and in particular, may have a curved shape, but is not limited thereto.

The encapsulant 330 may be filled in the cavity, and may include a phosphor (not shown). The encapsulant 330 may be formed of transparent silicone, epoxy, and other resin materials. After the encapsulant 330 is filled in the cavity, the encapsulant 330 may be formed by UV or thermal curing.

The phosphor (not shown) may be selected according to the wavelength of the light emitted from the light emitting device 320 to allow the light emitting device package 300 to realize white light.

The phosphor (not shown) included in the encapsulant 330 may be a blue light emitting phosphor, a cyan light emitting phosphor, a green light emitting phosphor, a yellow green light emitting phosphor, a yellow light emitting phosphor, or a yellowish red light according to a wavelength of light emitted from the light emitting device 320. One of the phosphor, the orange luminescent phosphor, and the red luminescent phosphor can be applied.

The phosphor (not shown) may be excited by the light having the first light emitted from the light emitting device 320 to generate the second light. For example, when the light emitting device 320 is a blue light emitting diode and the phosphor (not shown) is a yellow phosphor, the yellow phosphor may be excited by blue light to emit yellow light, and the blue light generated from the blue light emitting diode and As yellow light generated by excitation by blue light is mixed, the light emitting device package 300 may provide white light.

In the case where the light emitting device 320 is a green light emitting diode, a magenta phosphor or a blue and red phosphor (not shown) is used. In the case where the light emitting device 320 is a red light emitting diode, a cyan phosphor is used. The case where blue and green fluorescent substance are mixed is mentioned as an example.

The phosphor (not shown) may be a known one such as YAG, TAG, sulfide, silicate, aluminate, nitride, carbide, nitridosilicate, borate, fluoride, or phosphate.

The first electrode 340 and the second electrode 350 may be mounted on the body 310. The first electrode 340 and the second electrode 350 may be electrically connected to the light emitting device 320 to supply power to the light emitting device 320.

The first electrode 340 and the second electrode 350 are electrically separated from each other, and may reflect light generated from the light emitting device 320 to increase light efficiency. The first electrode 340 and the second electrode 350 may discharge heat generated from the light emitting device 320 to the outside.

In FIG. 4B, the light emitting device 320 is mounted on the first electrode 340, but is not limited thereto. The light emitting device 320, the first electrode 340, and the second electrode 350 may be wire bonded. May be electrically connected by any one of the following methods, a flip chip method, and a die bonding method.

The first electrode 340 and the second electrode 350 are made of a metal material, for example, titanium (Ti), copper (Cu), nickel (Ni), gold (Au), chromium (Cr), and tantalum (Ta). ), Platinum (Pt), tin (Sn), silver (Ag), phosphorus (P), aluminum (Al), indium (In), palladium (Pd), cobalt (Co), silicon (Si), germanium (Ge) ), Hafnium (Hf), ruthenium (Ru), iron (Fe) may include one or more materials or alloys. The first electrode 340 and the second electrode 350 may be formed to have a single layer or a multilayer structure, but is not limited thereto.

The light emitting device 320 may be mounted on the first electrode 340, and may be, for example, a light emitting device emitting light of red, green, blue, white, or UV (ultraviolet) light emitting device emitting ultraviolet light. However, the present invention is not limited thereto. One or more light emitting devices 320 may be mounted.

The light emitting device 320 may be applied to a horizontal type in which all of its electrical terminals are formed on the upper surface, or to a vertical type or flip chip formed on the upper and lower surfaces.

The light emitting device package 300 may include a light emitting device.

The light emitting device 320 may include a first active layer (not shown), a second active layer (not shown), and a carrier injection layer (not shown). The light emitting device 320, including a carrier injection layer (not shown), accelerates the mobility of holes provided from the second semiconductor layer (not shown) and provides the first active layer (not shown) and the second active layer (not shown). can do.

The light emitting device 320 including the carrier injection layer (not shown) may be included to maximize reliability and light extraction amount of the light emitting device package 300.

A plurality of light emitting device packages 300 according to the embodiment may be arranged on a substrate, and a light guide plate, a prism sheet, a diffusion sheet, or the like, which is an optical member, may be disposed on an optical path of the light emitting device package 300.

The light emitting device package 300, the substrate, and the optical member may function as a light unit. Another embodiment may be implemented as a display device, an indicator device, or a lighting system including a light emitting device (not shown) or a light emitting device package 300. For example, the lighting system may include a lamp or a street lamp. .

5A is a perspective view illustrating a lighting system 400 including a light emitting device according to an embodiment, and FIG. 5B is a cross-sectional view illustrating a cross-sectional view taken along line D-D ′ of the lighting system of FIG. 5A.

That is, FIG. 5B is a cross-sectional view of the illumination system 400 of FIG. 5A cut in the plane of the longitudinal direction Z and the height direction X, and viewed in the horizontal direction Y. FIG.

5A and 5B, the lighting system 400 may include a body 410, a cover 430 coupled to the body 410, and a closing cap 450 positioned at both ends of the body 410. have.

The lower surface of the body 410 is fastened to the light emitting device module 443, the body 410 is conductive and so that the heat generated from the light emitting device package 444 can be discharged to the outside through the upper surface of the body 410 The heat dissipation effect may be formed of an excellent metal material, but is not limited thereto.

The light emitting device package 444 includes a light emitting device (not shown).

The light emitting device package 444 may be mounted on the substrate 442 in multiple colors and in multiple rows to form a module. The light emitting device package 444 may be mounted at the same interval or may be mounted at various separation distances as necessary to adjust brightness. As the substrate 442, a metal core PCB (MCPCB) or a PCB made of FR4 may be used.

The cover 430 may be formed in a circular shape to surround the lower surface of the body 410, but is not limited thereto.

The cover 430 may protect the light emitting device module 443 from the foreign matters. The cover 430 may include diffusing particles to prevent glare of light generated from the light emitting device package 444 and to uniformly emit light to the outside, and may also include at least one of an inner surface and an outer surface of the cover 430. A prism pattern or the like may be formed on the surface. In addition, a phosphor may be applied to at least one of an inner surface and an outer surface of the cover 430.

Since the light generated from the light emitting device package 444 is emitted to the outside through the cover 430, the cover 430 should be excellent in light transmittance, and sufficient heat resistance to withstand the heat generated from the light emitting device package 444. The cover 430 is made of a material containing polyethylene terephthalate (PET), polycarbonate (PC), or polymethyl methacrylate (PMMA). Can be formed.

Closing cap 450 is located at both ends of the body 410 may be used for sealing the power supply (not shown). Power cap 452 is formed in the closing cap 450, the lighting system 400 according to the embodiment can be used immediately without a separate device to the terminal from which the existing fluorescent lamps are removed.

6 is an exploded perspective view of a liquid crystal display including a light emitting device according to an embodiment.

FIG. 6 illustrates an edge-light method, and the liquid crystal display 500 may include a liquid crystal display panel 510 and a backlight unit 570 for providing light to the liquid crystal display panel 510.

The liquid crystal display panel 510 may display an image by using light provided from the backlight unit 570. The liquid crystal display panel 510 may include a color filter substrate 512 and a thin film transistor substrate 514 facing each other with a liquid crystal interposed therebetween.

The color filter substrate 512 may implement colors of an image displayed through the liquid crystal display panel 510.

The thin film transistor substrate 514 is electrically connected to the printed circuit board 518 on which a plurality of circuit components are mounted through the driving film 517. The thin film transistor substrate 514 may apply a driving voltage provided from the printed circuit board 518 to the liquid crystal in response to a driving signal provided from the printed circuit board 518.

The thin film transistor substrate 514 may include a thin film transistor and a pixel electrode formed of a thin film on another substrate of a transparent material such as glass or plastic.

The backlight unit 570 may convert the light provided from the light emitting device module 520, the light emitting device module 520 into a surface light source, and provide the light guide plate 530 to the liquid crystal display panel 510. Reflective sheet for reflecting the light emitted from the rear of the light guide plate 530 and the plurality of films 550, 560, 564 to uniform the luminance distribution of the light provided from the 530 and improve the vertical incidence ( 540.

The light emitting device module 520 may include a PCB substrate 522 so that a plurality of light emitting device packages 524 and a plurality of light emitting device packages 524 may be mounted to form a module.

Including the light emitting device package 524, light extraction efficiency of the backlight unit 570 may be improved, and reliability of the backlight unit 570 may be further improved.

The backlight unit 570 is a diffusion film 566 for diffusing light incident from the light guide plate 530 toward the liquid crystal display panel 510 and a prism film 550 for condensing the diffused light to improve vertical incidence. It may be configured, and may include a protective film 564 for protecting the prism film 550.

7 is an exploded perspective view of a liquid crystal display including the light emitting device according to the embodiment. However, the parts shown and described in FIG. 6 will not be repeatedly described in detail.

7 is a direct view liquid crystal display 600 according to the embodiment. The liquid crystal display 600 may include a liquid crystal display panel 610 and a backlight unit 670 for providing light to the liquid crystal display panel 610. Since the liquid crystal display panel 610 is the same as that described with reference to FIG. 6, detailed description thereof will be omitted.

The backlight unit 670 may include a plurality of light emitting device modules 623, a reflective sheet 624, a lower chassis 630 in which the light emitting device modules 623 and the reflective sheet 624 are accommodated, and an upper portion of the light emitting device module 623. It may include a diffusion plate 640 and a plurality of optical film 660 disposed in the.

The light emitting device module 623 may include a PCB substrate 621 such that a plurality of light emitting device packages 622 and a plurality of light emitting device packages 622 may be mounted to form a module.

The reflective sheet 624 reflects the light generated from the light emitting device package 622 in the direction in which the liquid crystal display panel 610 is positioned to improve light utilization efficiency.

Light generated by the light emitting device module 623 is incident on the diffusion plate 640, and the optical film 660 is disposed on the diffusion plate 640. The optical film 660 includes a diffusion film 666, a prism film 650, and a protective film 664.

The light emitting device according to the embodiment may not be limitedly applied to the configuration and method of the embodiments described as described above, but the embodiments may be selectively combined with all or some of the embodiments so that various modifications may be made. It may be configured.

Although the embodiments have been illustrated and described above, the present invention is not limited to the above-described specific embodiments, and the present invention may be applied to those skilled in the art without departing from the gist of the present invention as claimed in the claims. Various modifications can be made by the user, and these modifications should not be individually understood from the technical spirit or the prospect of the present invention.

10: substrate
20: ODR layer
30: p-omic layer
40: transparent conductive layer
50: light emitting structure layer
52: first semiconductor layer
54: active layer
56: second semiconductor layer
60: reflective layer
70: ohmic layer
80: current blocking layer
90: first electrode
100: pad layer
110: the fourth layer
120: the third layer
130: second layer
140: first floor
142: hole

Claims

Light emitting structure layer;
A first layer disposed on the light emitting structure layer, the first layer comprising a light transmitting metal;
A second layer disposed on the first layer and comprising a reflective metal;
A fourth layer disposed on the second layer and including a wire bonding region;
A third layer positioned between the second layer and the fourth layer and having a conductivity that physically couples the second layer and the fourth layer,
A light emitting device in which a hole is formed in the first layer.

Light emitting structure layer;
A first layer disposed on the light emitting structure layer, the first layer comprising a light transmitting metal;
A second layer disposed on the first layer and comprising a reflective metal;
A fourth layer disposed on the second layer and including a wire bonding region;
A third layer positioned between the second layer and the fourth layer and having a conductivity that physically couples the second layer and the fourth layer,
A light emitting device in which a pattern is formed on the first layer.

The method according to claim 1 or 2,
The second layer has a thickness thinner than the fourth layer.

The method according to claim 1 or 2,
The thickness of the first layer is 1 nm to 10 nm,
The thickness of the second layer is 5nm to 30nm,
The thickness of the third layer is 50nm to 100nm,
The fourth layer has a thickness of 2㎛ to 500㎛.

The method according to claim 1 or 2,
The reflectance of the fourth layer is formed of a metal larger than the reflectance of the third layer,
The light emitting device of claim 2, wherein the reflectance of the second layer is greater than that of the third layer.

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The method of claim 1,
The diameter of the hole (hole) of the first layer is a light emitting device of 5㎛ to 1/2 of the horizontal length of the cross section of the first layer.

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