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, and only the embodiments make the disclosure of the present invention complete, and the general knowledge in the art to which the present invention belongs. 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 to 3 are cross-sectional views showing a cross section of a light emitting device according to one embodiment.
Referring to FIG. 1, a light emitting device 100 according to an embodiment is disposed on a substrate 110, a substrate 110, and a first semiconductor layer 132, a second semiconductor layer 136, and a first semiconductor. The light emitting structure 130 including the active layer 134 disposed between the layer 132 and the second semiconductor layer 136, the transparent electrode layer 160 and the transparent electrode layer 160 disposed on the second semiconductor layer 136. Disposed between the second electrode 150, the transparent electrode layer 160, and the second electrode 150, and minimizes the diffusion of oxygen included in the transparent electrode layer 160 to the second electrode 150. To include a diffusion limiting layer 170, the diffusion limiting layer 170 includes at least one of the elements of Group 4, Group 6 or Group 10.
The substrate 110 may be disposed under the first semiconductor layer 132. The substrate 110 may support the first semiconductor layer 132. The substrate 110 may receive heat from the first semiconductor layer 132. The substrate 110 may have a light transmissive property. For example, the substrate 110 may include sapphire (Al 2 O 3), but is not limited thereto. The substrate 110 may have a light transmissive property when using a light transmissive material or formed below a predetermined thickness, but is not limited thereto. The refractive index of the substrate 110 is preferably smaller than the refractive index of the first semiconductor layer 132 for light extraction efficiency, but is not limited thereto.
The substrate 110 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 110 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 110 is formed of a metal, the thermal stability of the light emitting device may be improved by facilitating the emission of heat generated from the light emitting device.
The substrate 110 may include a patterned substrate (PSS) structure on an upper surface thereof to increase light extraction efficiency, but is not limited thereto. The substrate 110 may improve the thermal stability of the light emitting device 100 by facilitating the emission of heat generated from the light emitting device 100. The substrate 110 may include a layer in which a difference between the first semiconductor layer 132 and the lattice constant exists so as to alleviate the lattice constant difference between the first semiconductor layer 132 and the first semiconductor layer 132.
The first semiconductor layer 132 may be disposed on the substrate 110. The first semiconductor layer 132 may be disposed on a buffer layer (not shown) to match the difference in lattice constant with the substrate 110, but is not limited thereto. The first semiconductor layer 132 may be grown on the substrate 110, but is not limited to the horizontal light emitting device but may be applied to the vertical light emitting device.
The first semiconductor layer 132 may be implemented as an n-type semiconductor layer. For example, when the light emitting device 100 emits light having a blue wavelength, 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 composition formula of = x + y = 1), for example, gallium nitride (GaN), aluminum nitride (AlN), aluminum gallium nitride (AlGaN), indium gallium nitride (InGaN), indium nitride (InN), and InAlGaN , AlInN and the like. For example, the first semiconductor layer 132 may be doped with n-type dopants such as silicon (Si), germanium (Ge), tin (Sn), selenium (Se), and tellurium (Te).
The first semiconductor layer 132 may receive power from the outside. The first semiconductor layer 132 may provide electrons to the active layer 134.
The active layer 134 may be disposed on the first semiconductor layer 132. The active layer 134 may be disposed between the second semiconductor layer 136 and the first semiconductor layer 132.
The active layer 134 may be formed of a semiconductor material. The active layer 134 may be formed in a single or multiple well structure using a compound semiconductor material of Group III-Group 5 elements. The active layer 134 may be formed of a nitride semiconductor. For example, the active layer 134 may include gallium nitride (GaN), indium gallium nitride (InGaN), indium gallium nitride (InAlGaN), or the like.
An active layer 134 that emits light when the blue light, for example, a compositional formula of In x Al y Ga 1 -x- y N (0 = x = 1, 0 = y = 1, 0 = x + y = 1) Barrier layer (not shown) having a composition formula of a well layer (not shown) having a structure and In a Al b Ga 1 -a- b N (0 = a = 1, 0 = b = 1, 0 = a + b = 1) It may have a single or multiple well structure having), but is not limited thereto. The well layer (not shown) may be formed of a material having a band gap smaller than the band gap of the barrier layer (not shown).
The active layer 134 may be formed by alternately stacking a plurality of well layers (not shown) and a barrier layer (not shown). The active layer 134 may include a plurality of well layers (not shown) to maximize light efficiency.
The well layer (not shown) may have a smaller energy band gap than the barrier layer (not shown). The well layer (not shown) may have a smaller energy band gap than the first semiconductor layer 132. The well layer (not shown) may have a continuous energy level of carrier.
The second semiconductor layer 136 may be formed on the active layer 134. The second semiconductor layer 136 may be implemented as a p-type semiconductor layer doped with a p-type dopant. When the light emitting element emitting light of a blue wavelength, a second semiconductor layer 136 is In x Al y Ga 1 -x- y N (0 = x = 1, 0 = y = 1, 0 = x + y Semiconductor material having a composition formula of = 1), for example, selected from gallium nitride (GaN), aluminum nitride (AlN), aluminum gallium nitride (AlGaN), indium gallium nitride (InGaN), indium nitride (InN), InAlGaN, AlInN, and the like. P-type dopants such as magnesium (Mg), zinc (Zn), calcium (Ca), strontium (Sr), and barium (Ba) may be doped.
The first semiconductor layer 132, the active layer 134, and the second semiconductor layer 136 may be formed of, for example, metal organic chemical vapor deposition (MOCVD), chemical vapor deposition (CVD), or plasma. Plasma-Enhanced Chemical Vapor Deposition (PECVD), Molecular Beam Epitaxy (MBE), Hydride Vapor Phase Epitaxy (HVPE), etc. It is not limited.
The doping concentrations of the conductive dopants in the first semiconductor layer 132 and the second semiconductor layer 136 may be formed uniformly or non-uniformly, but are not limited thereto.
When the light emitting device 100 is a horizontal light emitting diode, the first electrode 140 may be disposed in one region of the first semiconductor layer 132. The first electrode 140 may be electrically connected to the first semiconductor layer 132. The first electrode 140 may transfer power connected from the outside to the first semiconductor layer 132.
The second electrode 150 may be disposed in one region of the second semiconductor layer 136. The second electrode 150 may be electrically connected to the second semiconductor layer 136. The second electrode 150 may provide power to the second semiconductor layer 136 provided from the outside.
The first electrode 140 and the second electrode 150 are conductive materials such as indium (In), cobalt (Co), silicon (Si), germanium (Ge), gold (Au), palladium (Pd), Platinum (Pt), Ruthenium (Ru), Rhenium (Re), Magnesium (Mg), Zinc (Zn), Hafnium (Hf), Tantalum (Ta), Rhodium (Rh), Iridium (Ir), Tungsten (W), Selected from titanium (Ti), silver (Ag), chromium (Cr), molybdenum (Mo), niobium (Nb), aluminum (Al), nickel (Ni), copper (Cu), and titanium tungsten alloy (WTi) It may be formed as a single layer or multiple layers using a metal or an alloy, but is not limited thereto.
The transparent electrode layer 160 may be disposed between the second electrode 150 and the second semiconductor layer. The transparent electrode layer 160 may be in ohmic contact with the second semiconductor layer 136. The transparent electrode layer 160 may include one layer or a plurality of layers that are alternately stacked. The transparent electrode layer 160 may optionally include a light transmissive conductive layer and a metal layer. The transparent electrode layer 160 can smoothly inject the carrier into the second semiconductor layer 136.
For example, the transparent electrode layer 160 may be formed of indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IAZO), indium gallium zinc oxide (IGZO), or IGTO (IGTO). indium gallium tin oxide (AZO), aluminum zinc oxide (AZO), antimony tin oxide (ATO), gallium zinc oxide (GZO), IrO x , RuO x , RuO x / ITO, Ni, Ag, Ni / IrO x / Au, and One or more of Ni / IrO x / Au / ITO can be used to implement a single layer or multiple layers.
The diffusion limiting layer 170 may be disposed on the transparent electrode layer 160. The diffusion barrier layer 170 may include a metal material. For example, the diffusion barrier layer 170 may include at least one of elements of Group 4, Group 6, and Group 10.
For example, the diffusion barrier layer 170 may include titanium (Ti), zircon (Zr), hafnium (Hf), chromium (Cr), molybdenum (Mo), tungsten (W), nickel (Ni), and palladium (Pd). Or Pt (platinum).
The diffusion limiting layer 170 may prevent the transparent electrode layer 160 from diffusing to another layer of oxygen, thereby changing the internal composition. The diffusion limiting layer 170 may maintain the internal composition of the transparent electrode layer 160 to maintain the quality of the ohmic contact between the transparent electrode layer 160 and the second semiconductor layer 136.
The diffusion barrier layer 170 may include chromium (Cr) or titanium (Ti). The diffusion barrier layer 170 may include a metal oxide. For example, the diffusion barrier layer 170 may include MO x (M is a group 4, 6 or 10 atoms) molecules.
The diffusion barrier layer 170 may have a thickness of 2 to 10 nm.
When the diffusion limiting layer 170 is less than 2 nm in thickness, the thickness is thin, so that the oxygen of the transparent electrode layer 160 may not be prevented from diffusing into the layer disposed on the diffusion limiting layer 170. When the quality of the light source may be lowered and the thickness is greater than 10 nm, the thickness is so thick that the light emitted from the light emitting structure 130 may be absorbed to reduce the light extraction efficiency.
The diffusion barrier layer 170 may enhance the bonding force between the transparent electrode layer 160 and the layer disposed on the diffusion barrier layer 170. The diffusion limiting layer 170 may stabilize the operating voltage of the light emitting device 100.
Referring to FIG. 2, the light emitting device 100 may further include a bonding layer 174 disposed between the diffusion limiting layer 170 and the second electrode 150.
The bonding layer 174 may improve the adhesion between the second electrode 150 and the diffusion barrier layer 170. The bonding layer 174 may include at least one of Group 4, Group 6, or Group 10 elements.
For example, the bonding layer 174 may include titanium (Ti), zircon (Zr), hafnium (Hf), chromium (Cr), molybdenum (Mo), tungsten (W), nickel (Ni), palladium (Pd), or It may include at least one of Pt (platinum).
The bonding layer 174 may have a thickness of about 1 nm to about 5 nm. When the thickness of the bonding layer 174 is less than 1 nm, the thickness of the bonding layer disposed thereon may be too weak. If the thickness is 5 nm or more, the bonding layer 174 may emit light emitted from the light emitting structure 130. Absorption degree becomes high, and the light extraction efficiency of the light emitting element 100 can be reduced.
The light emitting device 100 may stack the bonding layer 174 and the diffusion barrier layer 170. When the diffusion limiting layer 170 is laminated to contact the bonding layer 174, the thickness may be 1 nm to 5 nm. When the diffusion limiting layer 170 is less than 1 nm in thickness, the thickness of the diffusion limiting layer 170 does not prevent the oxygen of the transparent electrode layer 160 from diffusing into the bonding layer 174, thereby degrading the quality of the light emitting device 100. When the thickness is greater than 5 nm, the thickness is so thick that the light emitted from the light emitting structure 130 may be absorbed to reduce light extraction efficiency.
In another exemplary embodiment, the bonding layer 174 may include a metal oxide. The bonding layer 174 may include chromium (Cr) or titanium (Ti). The bonding layer 174 may include a metal oxide. For example, the bonding layer 174 may include MO x (M is a group 4, 6 or 10 atoms) molecule.
Referring to FIG. 3, the light emitting device 100 may be a vertical light emitting device.
The support substrate 196 may be formed using a material having excellent thermal conductivity. In addition, the support substrate 196 may be formed of a conductive material. In this embodiment, the support substrate 196 may be formed using a metal material or a conductive ceramic. The conductive support substrate 196 may be formed of a single layer. In some embodiments, the conductive support substrate 196 may be formed in a multilayer structure.
The support substrate 196 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 different materials. In some embodiments, the support substrate 196 may be formed of a semiconductor material. For example, silicon (Si), germanium (Ge), gallium arsenide (GaAs), zinc oxide (ZnO), and silicon carbide (SiC) may be used. ), Silicon germanium (SiGe), gallium nitride (GaN), gallium (III) oxide (Ga 2 O 3 ) It can be implemented as a carrier wafer.
The support substrate 196 may improve the thermal stability of the light emitting device 100 by facilitating the emission of heat generated from the light emitting device.
A wafer bonding layer 194 may be formed on the support substrate 196 to bond the support substrate 196 and the conductive layer 192. The bonding layer 194 is, for example, from the group consisting of gold (Au), tin (Sn), indium (In), silver (Ag), nickel (Ni), niobium (Nb) and copper (Cu). It may be formed of the material selected or alloys thereof.
A Diffusion Barrier Layer 192 may be formed on the bonding layer 194. The conductive layer 192 may be made of nickel (Ni), platinum (Pt), titanium (Ti), tungsten (W), vanadium (V), iron (Fe), molybdenum (Mo), and the like.
Conductive layer 192 may be formed using a sputter deposition method. When using the sputtering deposition method, when ionized atoms are accelerated by an electric field and collide with the source material of the conductive layer 192, atoms of the source material are ejected and deposited. The conductive layer 192 may be formed by an electrochemical metal deposition method, a bonding method using a eutectic metal, or the like according to an embodiment. The conductive layer 192 may be formed of a plurality of layers according to an embodiment.
The conductive layer 192 may minimize mechanical damage (breaking or peeling, etc.) that may occur in the manufacturing process of the light emitting device. The conductive layer 192 prevents the metal material constituting the support substrate 196 or the bonding layer 194 from being diffused into the light emitting structure 130.
Second electrodes 160, 170, and 180 may be formed on the conductive layer 192. The second electrodes 160, 170, and 180 may include at least one of an ohmic layer 160, a reflective layer 180, and a bonding layer (not shown). For example, the second electrodes 160, 170, and 180 may have a stacked structure of a transparent electrode layer / reflective layer / bonding layer, a stacked structure of a transparent electrode layer / reflective layer, or a stacked structure of a reflective layer (including ohmic) / bonding layer. It does not limit to this. For example, the second electrodes 160, 170, and 180 may be formed by stacking the reflective layer 142 and the transparent electrode layer 160 on the conductive layer 192.
The reflective layer 180 may be disposed between the transparent electrode layer 160 and the conductive layer 192, and has a material having excellent reflective properties, such as silver (Ag), nickel (Ni), aluminum (Al), and rubidium (Rh). ), Palladium (Pd), iridium (Ir), ruthenium (Ru), magnesium (Mg), zinc (Zn), platinum (Pt), gold (Au), hafnium (Hf), and combinations thereof Or a metal material and indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IZAO), indium gallium zinc oxide (IGZO), indium gallium tin oxide (IGTO), and aluminum (AZO) It may be formed in a multi-layer using a transparent conductive material such as zinc oxide), antimony tin oxide (ATO). The reflective layer 180 may be laminated with IZO / Ni, AZO / Ag, IZO / Ag / Ni, AZO / Ag / Ni, or the like. When the reflective layer 180 is formed of a material in ohmic contact with the light emitting structure (eg, the second semiconductor layer 136), the transparent electrode layer 160 may not be separately formed, but is not limited thereto.
The transparent electrode layer 160 is in ohmic contact with the lower surface of the light emitting structure 130 and may be formed in a layer or a plurality of patterns. The transparent electrode layer 160 may selectively use a light transmissive conductive layer and a metal. For example, the transparent electrode layer 160 may be formed of indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IAZO), indium gallium zinc oxide (IGZO), or IGTO (IGTO). indium gallium tin oxide (AZO), aluminum zinc oxide (AZO), antimony tin oxide (ATO), gallium zinc oxide (GZO), IrO x , RuO x , RuO x / ITO, Ni, Ag, Ni / IrO x / Au, and One or more of Ni / IrO x / Au / ITO can be used to implement a single layer or multiple layers. The transparent electrode layer 160 is for smoothly injecting a carrier into the second semiconductor layer 136 and may be omitted.
The diffusion limiting layer 170 may be disposed below the transparent electrode layer 160. The diffusion barrier layer 170 may include a metal material. For example, the diffusion barrier layer 170 may include at least one of elements of Group 4, Group 6, and Group 10. Parts described in FIGS. 1 and 2 will not be described in further detail.
The second electrodes 160, 170, and 180 may include bonding layers (not shown). The bonding layer (not shown) may improve the adhesion between the diffusion barrier layer 170 and the reflective layer 180. The bonding layer (not shown) may include at least one of elements of Group 4, Group 6, or Group 10. The part described in FIG. 2 will not be described in further detail.
A current limiting layer (CBL) 198 may be formed on the second electrodes 160, 170, and 180. The current limiting layer 150 has a light transmissive property and may be formed of a nonconductive or weakly conductive material. The current limiting layer 198 may be made of silicon dioxide (SiO 2 ), or aluminum oxide (Al 2 O 3 ) including silicon dioxide (SiO 2 ).
The light emitting structure 130 is formed on the second electrodes 160, 170, and 180. The light emitting structure 130 may include a second semiconductor layer 136, an active layer 134, and a first semiconductor layer 132, and an active layer between the second semiconductor layer 136 and the first semiconductor layer 132. 134 may be configured to be interposed.
A first electrode 140 electrically connected to the first semiconductor layer 132 may be formed on the first semiconductor layer 132, and the first electrode 140 may be at least one pad (not shown) or / and predetermined. It may include an electrode having a pattern, but is not limited thereto. The first electrode 140 may be disposed in the center region, the outer region, or the corner region of the upper surface of the first semiconductor layer 132, but is not limited thereto. Meanwhile, the first electrode 140 may be connected to a pad (not shown) and at least one branch electrode (not shown) extending in at least one direction by being connected to the pad (not shown). The first electrode 140 may be disposed in a region other than the first semiconductor layer 132, but is not limited thereto.
Meanwhile, the first electrode 140 may be disposed on the flat upper surface of the first semiconductor layer 132 and may be disposed on the uneven portion 138 that is not flat, but is not limited thereto.
The first semiconductor layer 132 may include an uneven portion 138 formed over a portion of the surface or the entire region of the upper surface of the first semiconductor layer 132. The uneven portion 138 may be formed by etching an upper surface of the light emitting structure 130, for example, at least one region of the upper surface of the first semiconductor layer 132. The etching process may include a wet or / and dry etching process. Meanwhile, the etching surface may be N (nitride) 180) -face which may be easily etched by wet etching to form a more dense uneven portion, and surface roughness may be improved compared to Ga (gallium) -face. have. As the etching process is performed, an uneven portion 138 may be formed on the top surface of the first semiconductor layer 132 to form a light extraction structure. The uneven portion 138 may be irregularly formed in a random size, but is not limited thereto. The uneven portion 138 is an uneven upper surface, and may include at least one of a texture pattern, an uneven pattern, and an uneven pattern, but is not limited thereto.
Concave-convex portion 138 may be formed so that the side cross section has a variety of shapes, such as cylinder, polygonal pillar, cone, polygonal pyramid, truncated cone, polygonal truncated cone, etc., but may not include a horn shape.
The uneven portion 138 may be formed by a method such as PEC (photo electrochemical) or a wet etching method using a KOH solution, but is not limited thereto. As the uneven portion 138 is formed on the upper surface of the first semiconductor layer 132, light generated from the active layer 134 is totally reflected from the upper surface of the second conductive semiconductor layer 162 to be reabsorbed in the light emitting structure 130. Since it can be prevented or scattered, it can contribute to the improvement of the light extraction efficiency of the light emitting device.
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) ), Neogeotactic 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.
When the light emitting device 320 is a green light emitting diode, a magenta phosphor or a blue and red phosphor (not shown) is mixed. When the light emitting device 320 is a red light emitting diode, a cyan phosphor or a blue and green phosphor is mixed. For 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.
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.
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.
The light emitting device package 524 includes a light emitting device (not shown).
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 device 600 according to an 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, a 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 light emitting device package 622 includes a light emitting device (not shown).
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 preferred embodiments have been illustrated and described above, the invention is not limited to the specific embodiments described above, and does not depart from the gist of the invention as claimed in the claims. Various modifications can be made by the person having the above, and these modifications should not be individually understood from the technical spirit or the prospect of the present invention.
