KR20120086875A - A light emitting device - Google Patents

Abstract

PURPOSE: A light emitting device is provided to prevent a current from being centered a specific site of a light emitting structure by forming a current blocking layer on a partial area of a second conductivity type semiconductor layer. CONSTITUTION: A light emitting structure(120) is formed on a substrate(110). The light emitting structure comprises a first conductivity type semiconductor layer(122), an active layer(124), and a second conductivity type semiconductor layer(126). A conductive layer(130) is formed on the second conductivity type semiconductor layer. A first electrode is formed on a second portion of the first conductivity type semiconductor layer which is exposed by mesa etching. A second electrode(150) is formed on the conductive layer. The second electrode includes a second pad part(152) and a second branch electrode(154).

Description

Light emitting device

The present invention relates to a light emitting device and a light emitting device package.

A light emitting diode (LED) is a kind of semiconductor device that transmits and receives a signal by converting electricity into infrared light or light using characteristics of a compound semiconductor.

Group III-V nitride semiconductors are spotlighted as core materials of light emitting devices such as light emitting diodes (LEDs) or laser diodes (LDs) due to their physical and chemical properties.

These light emitting diodes do not contain environmentally harmful substances such as mercury (Hg) used in existing lighting equipment such as incandescent lamps and fluorescent lamps, and thus have excellent eco-friendliness and have advantages such as long life and low power consumption. It is replacing them.

Embodiments provide a light emitting device capable of improving luminous efficiency and yield.

The light emitting device according to the embodiment includes a substrate and a light emitting structure in which a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer are stacked on the substrate, wherein the light emitting structure includes first corner portions and the first light emitting structure. A first portion surrounded by the first sub-sides which are in contact, a second portion surrounded by the second corner portions and the second side-sides which are in contact, and the first conductivity type semiconductor layer between the first portion and the second portion And a third portion mesa etched to expose, wherein the first distance is greater than the square root of the sum of the square of the second distance and the square of the second distance, wherein the first distance is adjacent to any one of the first corner portions and adjacent thereto. The second distance is a distance between the second corner portion, and the second distance is the distance between any one of the first side and the second side surface adjacent to the first one of the first corner portion, the third distance The distance between the one of the rest in contact with one edge of the other one of the first side portion and a second portion adjacent to this side.

The second portion may be a mesa structure formed by mesa etching a portion of the second conductive semiconductor layer, the active layer, and the first conductive semiconductor layer. At least one of the second corner portions may have two or more bent surfaces, each of the bent surfaces abut each other, and adjacent bent surfaces may be perpendicular to each other. Any one of the at least two bent surfaces is bent from one second sublateral side that is in contact with at least one of the second corner portions, and another one of the at least two bent surfaces is one of the second corner portions. It may be bent from the other second sublateral side in contact with at least one.

The light emitting device may further include a conductive layer on the second conductive semiconductor layer, a first electrode on the exposed first conductive semiconductor layer, and a second electrode on the conductive layer.

Each of the second separation distance and the third separation distance may be greater than or equal to 1 micrometer and less than or equal to 100 micrometer.

At least one of the second corner portions may have two or more curved portions, and each of the curved portions may contact each other and have a constant radius of curvature. The curved portions may have the same radius of curvature. At least one of the curved portions may have a different radius of curvature.

The light emitting device according to the embodiment may improve luminous efficiency and yield.

1 is a plan view of a light emitting device according to a first embodiment.
FIG. 2 is a sectional view taken along the AB direction of the light emitting device illustrated in FIG. 1.
3 is a plan view illustrating a corner region of the light emitting device illustrated in FIG. 1.
4 is a perspective view illustrating a corner area of the light emitting device illustrated in FIG. 1.
5 is a plan view of a light emitting device according to a second embodiment.
6 is a plan view illustrating a corner area of the light emitting device illustrated in FIG. 5.
FIG. 7 is a perspective view illustrating a corner area of the light emitting device illustrated in FIG. 5.
8 is a plan view of a light emitting device according to a third embodiment.
9 illustrates a corner region of the light emitting device illustrated in FIG. 8.
FIG. 10 is a perspective view illustrating a corner area of the light emitting device illustrated in FIG. 8.
11 illustrates a light emitting device package according to an embodiment.
12A illustrates a display device including a light emitting device package according to an embodiment.
12B is a cross-sectional view of a light source portion of the display device illustrated in FIG. 12A.
13 illustrates a lighting device including a light emitting device according to the embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other features and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. In the description of an embodiment, each layer, region, pattern or structure may be "under" or "under" the substrate, each layer, region, pad or pattern. In the case where it is described as being formed at, "up" and "under" include both "directly" or "indirectly" formed through another layer. do. In addition, the criteria for the top / bottom or bottom / bottom of each layer are described with reference to the drawings.

In the drawings, dimensions are exaggerated, omitted, or schematically illustrated for convenience and clarity of illustration. In addition, the size of each component does not necessarily reflect the actual size. The same reference numerals denote the same elements throughout the description of the drawings. Hereinafter, a light emitting device and a light emitting device package according to an embodiment will be described with reference to the accompanying drawings.

1 illustrates a plan view of a light emitting device 100 according to an embodiment, and FIG. 2 illustrates a cross-sectional view along an AB direction of the light emitting device 100 illustrated in FIG. 1.

1 and 2, the light emitting device 100 includes a substrate 110, a light emitting structure 120, a current blocking layer 125, a conductive layer 130, a first electrode 140, and a second electrode. And 150.

The substrate 110 may be selected from the group consisting of sapphire substrate (Al ₂ O ₃ ), GaN, SiC, ZnO, Si, GaP, InP, Ga ₂ O ₃ , a conductive substrate, and GaAs. An uneven pattern may be formed on the upper surface of the substrate 110.

The light emitting structure 120 may include a first conductive semiconductor layer 122, an active layer 124, and a second conductive semiconductor layer 126, and may be sequentially stacked on the substrate 110. In this case, the first conductivity type may be n type and the second conductivity type may be p type, but is not limited thereto.

Between the substrate 110 and the light emitting structure 120, a layer or pattern using a compound semiconductor of Group 2 to 6 elements, such as a ZnO layer (not shown), a buffer layer (not shown), and an undoped semiconductor layer (not shown) At least one of the layers may be formed. The buffer layer or the undoped semiconductor layer may be formed using a compound semiconductor of group III-V group elements, and the buffer layer may reduce the difference in lattice constant with the substrate 110, and the undoped GaN layer may not be doped. It may be formed of a system semiconductor.

The first conductivity type semiconductor layer 122 may be selected from a nitride based semiconductor layer, for example, InAlGaN, GaN, AlGaN, InGaN, AlN, InN, AlInN, and the like, and an n-type dopant (eg, Si, Ge, Sn, etc.) may be Can be doped.

The active layer 124 may be formed of a single or multiple quantum well structure, a quantum-wire structure, a quantum dot structure, or the like using a compound semiconductor material of a group III-V group element. When the active layer 124 is formed of a quantum well structure, for example, a well layer having a composition formula of In _x Al _y Ga _1-xy N (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1); It may have a single or quantum well structure having a barrier layer having a composition formula of In _a Al _b Ga _{1 -a- b} N (0 _{≦ a ≦ 1} , 0 _{≦ b ≦ 1} , 0 _{≦ a} + b _{≦ 1} ). The well layer may be formed of a material having a band gap lower than the band gap of the barrier layer.

The second conductive semiconductor layer 126 may be selected from a nitride based semiconductor layer, for example, InAlGaN, GaN, AlGaN, InGaN, AlN, InN, AlInN, or the like, and may be a p-type dopant (eg, Mg, Zn, Ca, Sr, Ba) may be doped.

1 illustrates a light emitting structure 120 in a scribe line 105 which is a boundary line of a unit light emitting device. In this case, the scribe line 105 may be a chip separation line that separates the light emitting structure on the wafer into individual unit light emitting devices. Hereinafter, the side surface of the light emitting structure of the unit light emitting device separated along the scribe line 105 is referred to as the "scribing side surface of the light emitting structure 120 (see '405' of FIG. 4)".

The light emitting structure 120 may have a form in which the first conductive semiconductor layer 122, the active layer 124, and the second conductive semiconductor layer 126 are sequentially stacked on the substrate 110. A portion of the type semiconductor layer 122 may be exposed.

In this case, the exposed first conductive semiconductor layer 122 region includes a first region P1 and a second region P2. The first region P1 is a region of the first conductive semiconductor layer 122 adjacent to the scribe side, and the second region P2 is the first conductive semiconductor layer 122 on which the first electrode 140 is to be formed. May be another area of). The second region P2 may be located inside the first region P1 adjacent to one edge 192 of the scribe side.

For example, portions of the second conductive semiconductor layer 126, the active layer 124, and the first conductive semiconductor layer 122 on the first region P1 and the second region P2 are mesa-etched to form a first conductive layer. The first region P1 and the second region P2 of the type semiconductor layer 122 may be exposed.

Hereinafter, a side of the mesa structure (see '410' of FIG. 4) in which the second conductive semiconductor layer 122, the active layer 124, and a portion of the first conductive semiconductor layer 122 are formed by mesa etching is referred to as "mesa." Side ". In addition, a boundary line of the mesa structure 410 formed by mesa etching is called a mesa line 107, and the mesa line 107 is spaced apart from the scribe line 105.

The scribe side (see 405 of FIG. 4) of the light emitting structure 120 includes first sublateral sides 181 to 184, and first corner portions 191 to 194. Any one of the first corner portions (eg, 191) is located between adjacent first sidewalls (eg, 181 and 183) and abuts adjacent first sidewalls (eg, 181 and 183).

The mesa side of mesa structure 410 also includes second subsides, and second corner portions. One of the second corner portions is located between adjacent second subsides and abuts adjacent second subsides.

The second corner portion of the mesa side has a shape satisfying the following condition.

The first separation distance between the first corner portion and the second corner portion adjacent thereto is greater than the square root of the sum of the square of the second separation distance and the square of the third separation distance.

Here, the second separation distance is a separation distance between any one first side surface contacting the first corner portion and one second side surface contacting the second corner portion, and the third separation distance is another remaining side contacting the first corner portion. It may be a separation distance between one first sub-lateral side and the other second sub-lateral side in contact with the second corner portion.

3 is a plan view illustrating a corner region 170 of the light emitting device 100 illustrated in FIG. 1, and FIG. 4 is a perspective view illustrating a corner region 170 of the light emitting device illustrated in FIG. 1.

3 and 4, the second corner portion 301 of the mesa side of the mesa structure 410 is rounded. That is, the second corner portion 301 of the mesa side of the mesa structure 410 has a first radius of curvature R. Here, the first radius of curvature R may be a radius of a curve contacting the second side surfaces 312 and 314 contacting the second corner portion 301.

The second corner portion 301 of the mesa side of the mesa structure 410 according to the first embodiment satisfies the above condition. That is greater than the first clearance (C1) is a square root ^{(√ (A 2 + B 2} ) of the second sum of the squares and the square of the third distance (B) of the spacing ^{(A) (A 2 + B} 2) .

Here, the first separation distance C1 is a separation distance between the second corner portion 301 and the first corner portion 194 adjacent thereto, and the second separation distance A is in contact with the first corner portion 194. The separation distance between any one first subside 322 and any one second subside 312 in contact with the second corner portion 301, and the third separation distance B is the first corner portion 194. ) May be a distance between the other first side surface 324 in contact with the other side and the other second side surface 314 in contact with the second corner portion 301.

In this case, each of the second separation distance A and the third separation distance B may be greater than or equal to 1 μm and less than or equal to 100 μm (1um ≦ A, B ≦ 100um). Further, when each of the second separation distance A and the third separation distance B is greater than or equal to 20 μm and less than or equal to 100 μm (20 μm ≦ A, B ≦ 100 μm), the radius of curvature of the second corner portion 301 (R) may be greater than or equal to 1 µm and less than or equal to 50 µm (1 µ ≦ R ≦ 50 µm).

Further, when each of the second separation distance A and the third separation distance B is greater than or equal to 1 um and less than or equal to 20 um (1 um ≤ A, B ≤ 20 um), the radius of curvature of the second corner portion 301 (R) may be greater than or equal to 10 µm and less than or equal to 100 µm (10 µ ≦ R ≦ 100 µm).

In general, the light emitting area of the light emitting structure 120 may be increased by narrowing the gaps A and B between the mesa line and the scribe line. However, as the spacing between the mesa line and the scribe line is narrower, chip outside cracks generated during the chip separation process of separating into individual unit light emitting devices may invade the light emitting structure or the second electrode in the mesa line, thereby reducing the chip yield.

However, in the first exemplary embodiment, the first corner portion 194 and the second corner portion 301 of the mesa side of the mesa structure 410 adjacent to the scribe lines where the chip break occurs frequently meet the first curvature R. By forming a curved surface having a sufficient distance (C1) between the first corner portion 194 and the second corner portion 301, the cracks generated in the chip separation process is a light emitting structure 120 in the mesa line Invasion can be prevented, and a yield decrease can be prevented. That is, the first embodiment may improve the yield by preventing damage to the light emitting structure 120 due to cracks generated by the chip separation process.

In addition, the first embodiment emits light by reducing the second separation distance A and the third separation distance B within a limit capable of preventing damage to the light emitting structure 120 due to cracks generated by the chip separation process. It may be designed to relatively increase the light emitting area of the structure 120.

The current blocking layer 125 is disposed on a portion of the second conductivity-type semiconductor layer 126 to prevent the current from being concentrated at any part of the light emitting structure 120. For example, the current blocking layer 125 may be disposed on the second conductivity type semiconductor layer 126 of the mesa structure 410. The current blocking layer 125 may overlap the second electrode 150 in a vertical direction, which will be described later. The vertical direction may be a direction from the substrate 110 toward the light emitting structure 120. The current blocking layer 125 may be formed of an insulating material such as an oxide layer for blocking current. For example, the current blocking layer 125 may be formed of at least one of SiO ₂ , SiNx, TiO ₂ , Ta ₂ O ₃ , SiON, and SiCN.

The conductive layer 130 is disposed on the second conductive semiconductor layer 126. In this case, the conductive layer 130 is disposed on the second conductive semiconductor layer 126 of the mesa structure 410 and covers the current blocking layer 125. The conductive layer 130 serves to increase the light extraction efficiency of the light emitting device 100. The conductive layer 130 is a transparent oxide material having high transmittance with respect to the emission wavelength, such as indium tin oxide (ITO), tin oxide (TO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), and zinc (Zinc) Oxide) and the like.

The first electrode 140 is disposed on the second portion P2 of the first conductivity type semiconductor layer 122 exposed by mesa etching. The first electrode 140 includes a first pad part 142 and a first branch electrode 144. In this case, the first pad part 142 may be a part of the first electrode 140 on which the first pad is disposed. For example, the first pad part 142 may be an area in which a wire is bonded to receive the first power from the outside. The first branch electrode 144 may be the remaining portion of the first electrode 140 branched from the first pad part 142.

The first branch electrode 144 may branch from the first pad part 142 and extend in the first direction. The first direction may be a direction from the first edge 191 of the scribe side 405 of the light emitting structure 120 to the fourth edge 194. In addition, the first direction may be parallel to any one scribe side of the light emitting structure 120.

In this case, the second portion P2 of the first conductive semiconductor layer 122 exposed may be adjacent to the first edge (eg, 192) of one of the first edges 191 to 194 of the light emitting structure 120. Can be. The first pad part 142 is disposed on the second portion P2 of the first conductivity-type semiconductor layer 122 adjacent to one of the first edges, and the first branch electrode 144 is disposed on the first pad. Branching in the first direction to the portion 142 may be disposed on the first portion P1 of the first conductivity-type semiconductor layer 122.

Although the embodiment illustrated in FIG. 1 includes one first branch electrode 144 branching from the first pad part 142, the embodiment is not limited thereto and may include two or more first branch electrodes. have. At this time, the width of the first branch electrode 144 may be 5.0um ~ 20um.

The second electrode 150 is disposed on the conductive layer 130. The second electrode 150 includes a second pad part 152 and a second branch electrode 154. The second pad part 152 is a part of the second electrode 150 on which the second pad is disposed. For example, the first pad part 152 may be an area in which a wire is bonded to receive the second power from the outside. The second branch electrodes 154 may be the remaining part of the second electrode 165 branched from the second pad part 152.

The second pad part 152 may be disposed on the conductive layer 130 adjacent to the other one of the first edges 191 to 194 of the light emitting structure 120. The second branch electrode 154 may branch from one side of the second pad part 152 and extend in the second direction. Here, the second direction may be opposite to the first direction. The current blocking layer 125 may be disposed between the second conductive semiconductor layer 126 and the conductive layer 130 to overlap the second pad portion 152 and the second branch electrode 154 in a vertical direction. . The vertical direction may be a direction from the substrate 110 toward the light emitting structure 120.

5 is a plan view of a light emitting device 200 according to the second embodiment, FIG. 6 is a plan view showing a corner region 210 of the light emitting device 200 shown in FIG. 5, and FIG. 7 is shown in FIG. 5. It is a perspective view showing the edge area 210 of the light emitting device 200. The same parts as in the embodiment disclosed in FIGS. 1 and 4 are denoted by the same reference numerals and redundant descriptions thereof will be omitted. The cross-sectional structure of the light emitting device 200 according to the second embodiment may be the same as described with reference to FIG. 2.

5 to 7, the second corner portion 501 of the mesa side of the mesa structure 510 of the second embodiment may include at least two bent surfaces bent from adjacent second side surfaces 312 and 314. 522,524). Each of the bent surfaces 522 and 524 abuts each other, and adjacent bent surfaces may be perpendicular to each other.

Any one of the two or more bend surfaces (eg, 522) is bent from any second side surface (eg, 312) in contact with the second edge portion 501. Another one of the two or more bends (eg, 524) may be bent from the other second sublateral side (eg, 314) in contact with the second corner portion 501.

The first separation distance C2 between the second edge portion 501 of the mesa side of the mesa structure 510 and the first edge portion 194 adjacent thereto is the second separation distance A. Is greater than the square root of the sum of the square of and the square of the third spacing (B) (C2> √ (A ² + B ² )). In this case, the first separation distance C2 may be a separation distance between each of the bent surfaces 522 and 524 and the first edge portion 194.

Each of the second separation distance A and the third separation distance B may be greater than or equal to 1 μm and less than or equal to 100 μm. In the second embodiment shown in FIG. 6, the second corner portion 501 includes two bent surfaces, but is not limited thereto, and the second corner portion 501 may include three or more bent portions.

The second embodiment is the separation distance between the first corner portion 194 and the second corner portion 501 because the second corner portion 501 of the mesa side of the mesa structure 510 has the bent surfaces 522, 524. (C1) can be sufficiently secured, thereby preventing cracks generated in the chip separation process from invading into the light emitting structure 120 in the mesa line, thereby preventing a decrease in yield.

FIG. 8 is a plan view showing a light emitting device 300 according to the third embodiment, FIG. 9 is a plan view showing a corner region 310 of the light emitting device 300 shown in FIG. 8, and FIG. 10 is shown in FIG. 8. It is a perspective view showing the edge area 310 of the light emitting device 300. The same parts as in the embodiment disclosed in FIGS. 1 and 4 are denoted by the same reference numerals and redundant descriptions thereof will be omitted. The cross-sectional structure of the light emitting device 300 according to the third embodiment may be the same as described with reference to FIG. 2.

8 to 10, the second corner portion 601 of the mesa side of the mesa structure 610 of the third embodiment has at least two curved portions 622, 624, 626.

Each of the curved portions 622, 624, 626 abuts each other, and one of the curved portions (eg, 622) abuts any one second sublateral side (eg, 312) in contact with the second edge 601, and the other of the curved portions ( For example, 626 abuts the other second sublateral side (eg, 314) that abuts second edge portion 601.

Each of the curved portions 622, 624, 626 has a radius of curvature R1, R2, R3. One curved portion may contact the adjacent second subsides 312 and 314 or / and the adjacent curved portion.

For example, the first curved portion 622 may be in contact with one of the second sub-sides 312 and the second curved portion 624 and may have a curved surface having a first radius of curvature R1. In addition, the second curved portion 624 may be in contact with the first curved portion 622 and the third curved portion 626 and may have a curved surface having a second radius of curvature R2. The third curved portion 626 may be a curved surface having a third radius of curvature R3 in contact with the second sublateral surface 314 that is different from the second curved portion 624. Here, the first radius of curvature R1, the second radius of curvature R2, and the third radius of curvature R3 may be the same, or at least one may be different.

The first separation distance C3 between the second corner portion 601 of the mesa side of the mesa structure 610 according to the third embodiment and the first corner portion 194 adjacent thereto is the second separation distance A. Is greater than the square root of the sum of the square of and the square of the third spacing (B) (C2> √ (A ² + B ² )). In this case, the first separation distance C3 may be a separation distance between each of the curved portions 622, 624, and 626 and the first edge portion 194. The second separation distance A and the third separation distance B may be the same as described above.

The third embodiment provides a separation distance between the first corner portion 194 and the second corner portion 501 by having the second corner portion 601 of the mesa side of the mesa structure 610 with curved portions 622, 624, 626. C3) can be sufficiently secured. As a result, cracks generated in the chip separation process may be prevented from invading into the light emitting structure 120 in the mesa line, thereby preventing a decrease in yield.

11 illustrates a light emitting device package according to an embodiment. Referring to FIG. 11, the light emitting device package may include a package body 710, a first metal layer 712, a second metal layer 714, a light emitting device 720, a first wire 722, a second wire 724, The reflective plate 730 and the encapsulation layer 740 are included.

The package body 710 has a structure in which a cavity is formed in one region. At this time, the side wall of the cavity may be formed to be inclined. The package body 710 may be formed of a substrate having good insulation or thermal conductivity, such as a silicon-based wafer level package, a silicon substrate, silicon carbide (SiC), aluminum nitride (AlN), or the like. It may have a structure in which a plurality of substrates are stacked. Embodiment is not limited to the material, structure, and shape of the body described above.

The first metal layer 712 and the second metal layer 714 are disposed on the surface of the package body 710 to be electrically separated from each other in consideration of heat dissipation or mounting of a light emitting device. The light emitting device 720 is electrically connected to the first metal layer 712 and the second metal layer 714 through the first wire 722 and the second wire 724. In this case, the light emitting device 720 may be any one of the above-described embodiments.

For example, the first wire 722 electrically connects the second pad part 152 and the first metal layer 712 of the light emitting devices 100, 200, and 300 illustrated in FIGS. 1, 5, and 8, and the second wire. 724 may electrically connect the first pad part 142 and the second metal layer 714.

The reflector 730 is formed on the sidewall of the cavity of the package body 710 to direct light emitted from the light emitting device 720 in a predetermined direction. The reflector plate 730 is made of a light reflective material, and may be, for example, a metal coating or a metal flake.

The encapsulation layer 740 surrounds the light emitting device 720 positioned in the cavity of the package body 710 to protect the light emitting device 720 from the external environment. The encapsulation layer 740 is made of a colorless transparent polymer resin material such as epoxy or silicon. The encapsulation layer 740 may include a phosphor to change the wavelength of light emitted from the light emitting device 720. The light emitting device package may include at least one of the light emitting devices of the embodiments disclosed above, but is not limited thereto.

A plurality of light emitting device packages 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. The light emitting device package, the substrate, and the optical member may function as a backlight unit.

Another embodiment may be implemented as a display device, an indicator device, or a lighting system including the light emitting device or the light emitting device package described in the above embodiments, and for example, the lighting system may include a lamp or a street lamp.

12A illustrates a display device including a light emitting device package according to an embodiment, and FIG. 12B is a cross-sectional view of a light source portion of the display device illustrated in FIG. 12A.

12A and 12B, the display device includes a backlight unit, a liquid crystal display panel 860, a top cover 870, and a fixing member 850.

The backlight unit includes a bottom cover 810, a light emitting module 880 provided at one side of the bottom cover 810, a reflecting plate 820 disposed at the front of the bottom cover 810, and a reflecting plate ( The light guide plate 830 is disposed in front of the light guide module 880 to guide the light emitted from the light emitting module 880 to the front of the display device, and the optical member 840 is disposed in front of the light guide plate 830. The liquid crystal display 860 is disposed in front of the optical member 840, the top cover 870 is provided in front of the liquid crystal display panel 860, and the fixing member 850 is provided with the bottom cover 810 and the top cover. Disposed between 870 to fix bottom cover 810 and top cover 870 together.

The light guide plate 830 serves to guide the light emitted from the light emitting module 880 to be emitted in the form of a surface light source, and the reflective plate 820 disposed behind the light guide plate 830 may emit light emitted from the light emitting module 880. The light guide plate 830 is reflected in the direction to increase the light efficiency. However, the reflective plate 820 may be provided as a separate component as shown in the figure, or may be provided in the form of a high reflectivity coating on the back of the light guide plate 830, or the front of the bottom cover 810. . Here, the reflection plate 820 can be made of a material having a high reflectance and can be used in an ultra-thin shape, and polyethylene terephthalate (PET) can be used.

The light guide plate 830 scatters the light emitted from the light emitting module 880 so that the light is uniformly distributed over the entire screen of the liquid crystal display. Therefore, the light guide plate 830 is made of a material having a good refractive index and a high transmittance, and may be formed of polymethyl methacrylate (PMMA), polycarbonate (PC), polyethylene (PE), or the like.

In addition, an optical member 840 is provided on the light guide plate 830 to diffuse light emitted from the light guide plate 830 at a predetermined angle. The optical member 840 uniformly radiates the light guided by the light guide plate 830 toward the liquid crystal display panel 860.

As the optical member 840, an optical sheet such as a diffusion sheet, a prism sheet, or a protective sheet may be selectively laminated, or a micro lens array may be used. In this case, a plurality of optical sheets may be used, and the optical sheets may be made of a transparent resin such as acrylic resin, polyurethane resin, or silicone resin. The fluorescent sheet may be included in the above-described prism sheet as described above.

The liquid crystal display panel 860 may be provided on the front surface of the optical member 840. Here, it is obvious that other types of display devices requiring a light source besides the liquid crystal display panel 860 may be provided.

The reflective plate 820 is placed on the bottom cover 810, and the light guide plate 830 is placed on the reflective plate 820. Thus, the reflector plate 820 may be in direct contact with the heat radiation member (not shown). The light emitting module 880 includes a light emitting device package 882 and a printed circuit board 881. The light emitting device package 882 is mounted on the printed circuit board 881. The light emitting device package 881 may be the embodiment shown in FIG. 11.

The printed circuit board 881 may be bonded on the bracket 812. Here, the bracket 812 is made of a material having high thermal conductivity for heat dissipation in addition to the fixing of the light emitting device package 882, and although not shown, a thermal pad is provided between the bracket 812 and the light emitting device package 882. To facilitate heat transfer. In addition, the bracket 812 is provided as a 'b' type as shown, the horizontal portion 812a is supported by the bottom cover 810, the vertical portion 812b is fixed to the printed circuit board 881 can do.

13 illustrates a lighting apparatus 900 including a light emitting device package according to the embodiment. Referring to FIG. 12, the lighting device 900 includes a power coupling unit 910, a heat sink 920, a light emitting module 930, a reflector 940, and a cover cap 950. ), And the lens unit 960.

The power coupling unit 910 has a screw shape in which an upper end is inserted into an external power socket (not shown), and is inserted into an external power socket to supply power to the light emitting module 930. The heat dissipation plate 920 emits heat generated from the light emitting module 930 to the outside through the heat dissipation pins formed at the side surfaces. The upper end of the heat dissipation plate 920 is screwed with the lower end of the power coupling unit 910.

A light emitting module 840 including light emitting device packages mounted on a circuit board is fixed to a bottom surface of the heat dissipation plate 920. In this case, the light emitting device packages may be light emitting device packages according to the exemplary embodiment shown in FIG. 11.

The lighting apparatus may further include an insulating sheet 932 and a reflective sheet 934 for electrically protecting the light emitting module 930 under the light emitting module 930. In addition, an optical member that performs various optical functions may be disposed on a path of the light radiated by the light emitting module 930.

The reflector 940 is combined with the lower end of the heat dissipation plate 920 in the shape of a truncated cone and reflects light emitted from the light emitting module 930. The cover cap 950 has a circular ring shape and is coupled to the bottom of the reflector 940. The lens unit 960 is fitted to the cover cap 950. 12 may be embedded in a ceiling or a wall of a building and used as a downlight.

Features, structures, effects, and the like described in the above embodiments are included in at least one embodiment of the present invention, and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, and the like illustrated in the embodiments may be combined or modified with respect to other embodiments by those skilled in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

110 substrate 120 light emitting structure
122: first conductive semiconductor layer 124: active layer
126: second conductive semiconductor layer 125: current blocking layer
130: conductive layer 135: first insulating layer 140: first electrode 142: first pad portion
144: first branch electrode 150: second electrode
152: second pad portion 154, 156: second branch electrode
191-194: corners 181-184: sides
710: package body 712, 714: first, second metal layer
720: light emitting element 722, 724: first and second wires
730: reflector 740: encapsulation layer
810: bottom cover 820: reflector
830: light guide plate 840: optical member
850: Fixed member 860: Liquid crystal display panel
870: top cover 880: light emitting module
910: power coupler 920: heat dissipation plate
930: light emitting module 940: reflector
950: cover cap 960: lens unit

Claims (9)

Board; And
A light emitting structure in which a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer are stacked on the substrate,
The light emitting structure,
A first portion surrounded by the first corner portions and the first subsides in contact with the first corner portions;
A second portion surrounded by second corner portions and second subsides contacting the second corner portions; And
A third portion mesa-etched to expose the first conductivity type semiconductor layer between the first portion and the second portion,
The first distance is greater than the square root of the sum of the square of the second distance and the square of the second distance, wherein the first distance is the distance between any one of the first corner portions and the second corner portion adjacent thereto, and the second distance The distance is the distance between any one of the first sub-sides which are in contact with the first corner portion and the second sub-lateral side which is adjacent thereto, and the third distance is the other one made in contact with the one of the first corner portions. A light emitting device, wherein the distance is between the first subside and the second sublateral side adjacent thereto. The method of claim 1,
And the second portion is a mesa structure formed by mesa etching the second conductive semiconductor layer, the active layer, and a portion of the first conductive semiconductor layer. The method of claim 2,
At least one of the second corner portions has two or more bent surfaces,
Each of the bent surfaces abuts each other, and adjacent bent surfaces are perpendicular to each other. The method of claim 3,
Any one of the at least two bent surfaces is bent from one second sublateral side that is in contact with at least one of the second corner portions, and another one of the at least two bent surfaces is one of the second corner portions. A light emitting device is bent from the other second side surface of the other in contact with at least one. The method of claim 1, wherein the light emitting device,
A conductive layer on the second conductive semiconductor layer;
A first electrode on the exposed first conductive semiconductor layer; And
The light emitting device further comprises a second electrode on the conductive layer. The method of claim 1,
Wherein each of the second separation distance and the third separation distance is greater than or equal to 1 micrometer and less than or equal to 100 micrometer. The method of claim 2,
At least one of the second corner portions has two or more curved portions,
Each of the curved portions is in contact with each other, the light emitting device having a constant radius of curvature. The method of claim 6,
The curved parts have the same radius of curvature. The method of claim 6,
At least one of the curved portions has a different radius of curvature.

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