KR20130039574A

KR20130039574A - Light emitting device

Info

Publication number: KR20130039574A
Application number: KR1020110104233A
Authority: KR
Inventors: 박동욱
Original assignee: 엘지이노텍 주식회사
Priority date: 2011-10-12
Filing date: 2011-10-12
Publication date: 2013-04-22

Abstract

PURPOSE: A light emitting device is provided to improve the luminous efficiency of a flip chip type light emitting device and to secure stability and reliability in a mounting process for a light emitting device package. CONSTITUTION: A light emitting structure includes a semiconductor layer(120), a second semiconductor layer, and an active layer. A first electrode(170) is arranged on the semiconductor layer of a first region(B). The area ratio of the first region to a second semiconductor layer is 0.41 to 1. A second electrode(180) is arranged on the second semiconductor layer. The second electrode is connected to the light transparent electrode layer(150).

Description

[0001]

The embodiment relates to a light emitting device that improves the luminous efficiency of a flip chip type light emitting device and ensures stability and reliability when mounting the light emitting device package.

As a typical example of a light emitting device, a light emitting diode (LED) is a device for converting an electric signal into an infrared ray, a visible ray, or a light using the characteristics of a compound semiconductor, and is used for various devices such as household appliances, remote controllers, Automation equipment, and the like, and the use area of LEDs is gradually widening.

In general, miniaturized LEDs are made of a surface mounting device for mounting directly on a PCB (Printed Circuit Board) substrate, and an LED lamp used as a display device is also being developed as a surface mounting device type . Such a surface mount device can replace a conventional simple lighting lamp, which is used for a lighting indicator for various colors, a character indicator, an image indicator, and the like.

As the use area of the LED is widened as described above, it is important to increase the luminance of the LED as the brightness required for a lamp used in daily life and a lamp for a structural signal is increased.

The embodiment provides a light emitting device that improves the luminous efficiency of a flip chip type light emitting device and ensures stability and reliability when mounting the light emitting device package.

In the light emitting device according to the embodiment, a light emitting structure including an active layer between the first semiconductor layer, the second semiconductor layer and the first semiconductor layer and the second semiconductor layer, a portion of the upper surface of the first semiconductor layer includes a first region. And a first electrode disposed on the first semiconductor layer of the first region and a second electrode disposed on the second semiconductor layer, wherein the first electrode includes a side surface of the second semiconductor layer and The first surface may be spaced apart from the side surface of the active layer, and the upper surface may have an area of 40% to 99% of the area of the second semiconductor layer.

Since a separate bump is not required when mounting the light emitting device in a flip type, this has the effect of reducing cost and production time.

1 is a plan view illustrating a light emitting device according to an embodiment.
FIG. 2 is a cross-sectional view showing a cross section taken along the line A-A 'of the light emitting device shown in FIG.
3 is a cross-sectional view showing a light emitting device according to another embodiment.
FIG. 4 is a view illustrating a conventional light emitting device in which flip chip bonding is performed on a package substrate.
5 is a view illustrating a form in which a light emitting device according to the embodiment is flip chip bonded to a package substrate.
6 is a cross-sectional view illustrating a light emitting device according to yet another embodiment.
7 is a sectional view showing a light emitting device according to another embodiment.
8 is a sectional view showing a light emitting device according to another embodiment.
9 is a sectional view showing a light emitting device according to another embodiment.
10 is a view illustrating emission of light in a form in which a light emitting device according to the embodiment is flip chip bonded to a package substrate.
11 is a cross-sectional view of a light emitting device package including a light emitting device according to an embodiment.
12 is a perspective view illustrating a lighting apparatus including a light emitting device package according to an embodiment.
FIG. 13 is a cross-sectional view illustrating a CC ′ section of the lighting apparatus of FIG. 12.
14 is an exploded perspective view of a liquid crystal display including the light emitting device according to the embodiment.
15 is an exploded perspective view of a liquid crystal display including the light emitting device according to the 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. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

The terms spatially relative, "below", "beneath", "lower", "above", "upper" May be used to readily describe a device or a relationship of components to other devices or components. Spatially relative terms should be understood to include, in addition to the orientation shown in the drawings, terms that include different orientations of the device during use or operation. 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 include both downward and upward directions. 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 the present specification, the singular form includes plural forms unless otherwise specified in the specification. It is noted that the terms "comprises" and / or "comprising" used in the specification are intended to be inclusive in a manner similar to the components, steps, operations, and / Or 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. Also, commonly used predefined terms are not ideally or excessively interpreted unless explicitly defined otherwise.

The thickness and size of each layer in the drawings are exaggerated, omitted, or schematically shown for convenience and clarity of explanation. Also, the size and area of each component do not entirely reflect actual size or area.

Further, the angle and direction mentioned in the description of the structure of the light emitting device in the embodiment are based on those shown in the drawings. In the description of the structure of the light emitting device in the specification, reference points and positional relationship with respect to angles are not explicitly referred to, refer to the related drawings.

1 is a plan view showing a light emitting device according to an embodiment, and FIG. 2 is a cross-sectional view showing a cross section taken along line A-A 'of the light emitting device shown in FIG.

1 and 2, the light emitting device 100 includes a support member 110 and a light emitting structure disposed on the support member 110, and the light emitting structure includes the first semiconductor layer 120 and the second semiconductor. The layer 140 may include an active layer 130 between the first semiconductor layer 120 and the second semiconductor layer 140.

The support member 110 may be formed of any material having optical transparency, for example, sapphire (Al ₂ O ₃ ), GaN, ZnO, or AlO. However, the support member 110 is not limited thereto. Further, it can be a SiC supporting member having a higher thermal conductivity than a sapphire (Al ₂ O ₃ ) supporting member. However, it is preferable that the refractive index of the support member 110 is smaller than the refractive index of the first semiconductor layer 120 for the light extraction efficiency.

On the other hand, the lower surface of the support member 110 may be formed with a surface concave-convex pattern 112 to improve the light extraction efficiency.

The surface uneven pattern 112 is formed on the surface opposite to the surface on which the light emitting structure is to be formed, the forming method may be formed by an etching method, preferably dry etching, wet etching, etc. may be used, but is not limited thereto. It doesn't work. That is, the light extraction efficiency is increased by preventing total reflection of the light emitted by the surface irregularities.

A buffer layer (not shown) may be disposed on the support member 110 to mitigate lattice mismatch between the support member 110 and the first semiconductor layer 120 and allow the semiconductor layer to grow easily. The buffer layer (not shown) may be formed in a low temperature atmosphere, and may be formed of a material capable of alleviating the difference in lattice constant between the semiconductor layer and the support member. For example, materials such as GaN, InN, AlN, AlInN, InGaN, AlGaN, and InAlGaN can be selected and not limited thereto.

A light emitting structure including the first semiconductor layer 120, the active layer 130, and the second semiconductor layer 140 may be formed on the buffer layer (not shown).

The first semiconductor layer 120 may be located on a buffer layer (not shown). The first semiconductor layer 120 may be formed of an n-type semiconductor layer and may provide electrons to the active layer 130. The first semiconductor layer 120 is, for example, semiconductor material having a compositional formula of _{In x Al y Ga 1 -x- y} N (0≤x≤1, 0≤y≤1, 0≤x + y≤1) For example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, etc. may be selected, and n-type dopants such as Si, Ge, Sn, and the like may be doped.

Further, the semiconductor layer 120 may further include an undoped semiconductor layer (not shown), but the present invention is not limited thereto. The un-doped semiconductor layer is a layer formed for improving the crystallinity of the first semiconductor layer 120 and has a lower electrical conductivity than the first semiconductor layer 120 without doping the n-type dopant. May be the same as the semiconductor layer 120.

The active layer 130 may be formed on the first semiconductor layer 120. The active layer 130 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 Group 3-V group elements.

An active layer 130, the well having a composition formula of, for _{example, In x Al y Ga 1 -x-} y N (0≤x≤1, 0 ≤y≤1, 0≤x + y≤1) if formed of a quantum well structure, _Have a single or multiple quantum well structure having a layer and a barrier layer having a compositional formula of In _a Al _b Ga ₁ _-a- _b N ( _{0≤a≤1, 0≤b≤1, 0≤a} + b≤1) Can be. The well layer may be formed of a material having a band gap smaller than the band gap of the barrier layer.

A conductive clad layer (not shown) may be formed on and / or below the active layer 130. The conductive clad layer (not shown) may be formed of an AlGaN-based semiconductor and may have a band gap larger than that of the active layer 130.

The second semiconductor layer 140 may be implemented as a p-type semiconductor layer to inject holes into the active layer 130. A second semiconductor layer 140 is, for example, semiconductor material having a compositional formula of _{In x Al y Ga 1 -x- y} N (0≤x≤1, 0≤y≤1, 0≤x + y≤1) For example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, etc. may be selected, and p-type dopants such as Mg, Zn, Ca, Sr, and Ba may be doped.

Meanwhile, an intermediate layer (not shown) may be formed between the active layer 130 and the second semiconductor layer 140, and the electrons injected into the active layer 130 from the first semiconductor layer 120 may be formed when a high current is applied. It may be an electron blocking layer that does not recombine in the active layer 130 and prevents a phenomenon flowing to the second semiconductor layer 140. The intermediate layer has a band gap relatively larger than that of the active layer 130, thereby preventing electrons injected from the first semiconductor layer 120 from being injected into the second semiconductor layer 140 without being recombined in the active layer 130. Can be. Accordingly, the probability of recombination of electrons and holes in the active layer 130 may be increased and leakage current may be prevented.

Meanwhile, the above-described intermediate layer may have a band gap larger than that of the barrier layer included in the active layer 130, and may be formed of a semiconductor layer including Al, such as p-type AlGaN, but is not limited thereto.

The first semiconductor layer 120, the active layer 130, and the second semiconductor layer 140 may be, for example, metal organic chemical vapor deposition (MOCVD) or chemical vapor deposition (CVD). Plasma-Enhanced Chemical Vapor Deposition (PECVD), Molecular Beam Epitaxy (MBE), Hydride Vapor Phase Epitaxy (HVPE), and Sputtering It may be formed, but not limited thereto.

In addition, the doping concentrations of the conductive dopants in the first semiconductor layer 120 and the second semiconductor layer 140 may be uniformly or non-uniformly formed. That is, the plurality of semiconductor layers may be formed to have various doping concentration distributions, but the invention is not limited thereto.

In addition, the first semiconductor layer 120 may be implemented as a p-type semiconductor layer, the second semiconductor layer 140 may be implemented as an n-type semiconductor layer, and the n-type or p-type semiconductor on the second semiconductor layer 140. A third semiconductor layer (not shown) including a layer may be formed. Accordingly, the light emitting device 100 may have at least one of np, pn, npn, and pnp junction structures.

In addition, the transparent electrode layer 150 may be disposed on the second semiconductor layer 140, wherein the second electrode 180 is connected to the second semiconductor layer 140 or is formed to be connected to the transparent electrode layer 150. Can be. However, the present invention is not limited thereto.

The transparent electrode layer 150 is formed of ITO, IZO (In-ZnO), GZO (Ga-ZnO), AZO (Al-ZnO), AGZO (Al-Ga ZnO), IGZO (In-Ga ZnO), IrO _x , RuO _x , RuO _x / ITO, Ni / IrO _x / Au, and Ni / IrO _x / Au / ITO, and may be formed, and formed on the entire outer surface of the second semiconductor layer 140, thereby forming a current grouping phenomenon. Can be prevented.

In addition, in the light emitting device 100, a portion of the upper surface of the first semiconductor layer 120 is exposed with the first region B, and is disposed on the first semiconductor layer 120 in the first region B. It may include a second electrode 180 disposed on the electrode 170 and the second semiconductor layer 140.

A portion of the upper surface of the first electrode 170 may be exposed with the first region B, and the first electrode 170 may be disposed on the first semiconductor layer 120 in the first region B. Referring to FIG. In other words, at least the second semiconductor layer 140 and the active layer 130 may be partially removed to expose the first semiconductor layer 120 with the first region B and to arrange the first electrode 170 thereon. will be.

The first electrode 170 may be spaced apart from the side surface of the second semiconductor layer 140 and the side surface of the active layer 130 with a first distance.

The area of the upper surface of the first electrode 170 may have an area of about 40% to about 99% of the area of the second semiconductor layer 140. Here, the area is based on the surface seen when the light emitting device 100 is viewed from above. The same applies to the following. When the area of the first electrode 170 is smaller than 40% of the area of the second semiconductor layer 140, when the light emitting device 100 is mounted on the light emitting device package in a flip chip type, the electrode is small and needs bumps. When the fixing force is weak, there is a problem in reliability and stability of the light emitting device package, and when the area of the first electrode 170 is greater than 99% of the area of the second semiconductor layer 140, the first electrode 170 is disposed. In order to remove too much of the second semiconductor layer 140 and the active layer 130 of the light emitting device 100 there is a problem that the luminous efficiency is lowered. Therefore, as described above, when the first electrode 170 is formed, it has an effect of having stability at the same time when the flip chip type is mounted with appropriate light efficiency.

Meanwhile, the first and second electrodes 170 and 180 may be conductive materials, for example, In, Co, Si, Ge, Au, Pd, Pt, Ru, Re, Mg, Zn, Hf, Ta, Rh, Ir It may include a metal selected from W, Ti, Ag, Cr, Mo, Nb, Al, Ni, Cu, and WTi, or may include an alloy thereof, and may be formed in a single layer or multiple layers, and limited thereto. Not.

The first distance may have a suitable distance from which the short protection and the insulation layer can be inserted. However, the present invention is not limited thereto.

The area of the first region B may be 41% to 100% of the area of the second semiconductor layer 140. In other words, the first region B may have a larger area than the first electrode 170 so that the first electrode 170 may be disposed therein based on the view from the upper side. However, the present invention is not limited thereto.

If the second electrode 180 has an area that is too large in comparison with the second semiconductor layer 140, the light extraction efficiency of the light emitting device is reduced. If the area of the second electrode 180 is too small, the light emitting device 100 is flip-chip type in the light emitting package. Since there is a problem in reliability at the time of mounting, it may have an area of 40% to 100% of the area of the second semiconductor layer 140. However, the present invention is not limited thereto.

The first electrode 170 or the second electrode 180 may have a rectangular, polygonal or circular shape as viewed from above. However, the present invention is not limited thereto.

In this case, the first area B may have a rectangular, polygonal or circular shape as viewed from above. However, the present invention is not limited thereto.

Although it is preferable that the shape seen from the upper side of the 1st area | region B and the 1st electrode 170 is the same, it may have a different shape.

Upper surfaces of the first electrode 170 and the second electrode 180 may be positioned on the same line. Such a configuration does not require bumps when the light emitting device 100 is mounted in a flip chip type in a light emitting device package, thereby reducing the cost of bumps and improving the reliability of mounting the electrodes.

3 is a cross-sectional view showing a light emitting device according to another embodiment.

Referring to FIG. 3, the light emitting device 200 according to the embodiment includes a light emitting device 200 including a support member 210 and a light emitting structure disposed on the support member 210, and the light emitting structure includes a first semiconductor layer 220. ), A second semiconductor layer 240, and an active layer 230 between the first semiconductor layer 220 and the second semiconductor layer 240. Description of the same components as those described in FIGS. 1 and 2 will be omitted below.

In addition, the transmissive electrode layer 250 may be disposed on the second semiconductor layer 240. In this case, the second electrode 280 is connected to the second semiconductor layer 240 or is connected to the transmissive electrode layer 250. Can be. However, the present invention is not limited thereto.

In addition, in the light emitting device 200, a portion of the upper surface of the first semiconductor layer 220 is exposed with the first region B, and is disposed on the first semiconductor layer 220 of the first region B. It may include a second electrode 280 disposed on the electrode 270 and the second semiconductor layer 240.

The first electrode 270 may be spaced apart from the side surface of the second semiconductor layer 240 and the side surface of the active layer 230 with a first distance.

Here, the first electrode 270 is connected to one end of the lower electrode 272 and the lower electrode 272 connected on the first semiconductor layer 220 to form an upper electrode of the first electrode 270 ( 274).

The lower electrode 272 may be disposed to at least the height of the second semiconductor layer 240. The material of the lower electrode 272 may be the same material as that of the second electrode 280 described above.

The upper electrode 274 is connected to one end of the lower electrode 272 to protrude into the light emitting structure, and the second semiconductor layer 240 partially overlaps a portion of the light emitting structure, and the upper surface of the second semiconductor layer 240 It may be spaced apart. In other words, the first electrode 270 may have a cross-sectional shape. That is, the upper surface of the upper electrode 274 is a surface to be mounted when the light emitting device package is mounted, and the lower electrode 272 serves to connect the first semiconductor layer 220 and the upper electrode 274.

In this case, when the area of the lower electrode 272 is smaller than 10% of the area of the upper electrode 274, there is a problem in supplying electricity to the first semiconductor layer 220, and the area of the lower electrode 272 is the upper electrode 274. ) Is larger than 50% of the area, the first region B is etched in correspondence to the lower electrode 272, thereby lowering the luminous efficiency of the light emitting device. Therefore, the area of the lower electrode 272 viewed from above may be 10% to 50% of the upper electrode 274.

Here, the area of the upper surface viewed from the upper side of the first electrode 270 means the area of the upper electrode 274 viewed from the upper side. An area of the upper surface of the first electrode 270 viewed from the upper side may have an area of 40% to 99% of the area of the second semiconductor layer 240.

As such, the area of the lower electrode 272 is made smaller than that of the upper electrode 274, and the area of the upper electrode 274 is wider to form the second semiconductor layer 240 and the active layer 230 of the light emitting device 200. ) Area is reduced, which can minimize the reduction in luminous efficiency, and has the effect of having stability at the time of flip chip type mounting.

FIG. 4 is a view illustrating a form in which a conventional light emitting device is flip chip bonded to a package substrate, and FIG. 5 is a view illustrating a form in which a light emitting device according to the embodiment is flip chip bonded to a package substrate.

Referring to FIG. 4, a light emitting device 1000 flip-bonded on a package substrate 1390 is shown. On the other hand, the conductor patterns (1392, 1394) are formed on the package substrate 1390, the conductor patterns (1392, 1394) through the solder (1396, 1398), the second electrode pad 1182 and the first electrode of the flip chip type light emitting device. It is electrically connected to the electrode pad 1172.

As described above, the conventional light emitting device 1000 requires bumps due to the difference in height between the second electrode pad 1182 and the first electrode pad 1172 when the package substrate 1390 is mounted on the package substrate 1390. There is a problem in stability.

Referring to FIG. 5, the light emitting device 100 flip-bonded on the package substrate 190 is illustrated. The conductive patterns 192 and 194 may be formed on the package substrate 190, and the conductive patterns 192 and 194 may be electrically connected to the second electrode 182 and the first electrode 172 in a flip chip type.

As described above, since the electrode having a large area is used, the mounting stability is increased, and since the electrode has a large area, it is easy to increase the vertical height of the electrode, thereby eliminating the need for a separate bump.

In the case of the flip chip type light emitting device, the heat dissipation is the biggest problem as the brightness of the light emitting device increases.

6 is a cross-sectional view illustrating a light emitting device according to yet another embodiment.

Referring to FIG. 6, there is a difference in that the light emitting device 100 of the embodiment includes the insulating layer 168 as compared with the light emitting device of FIG. 2.

The insulating layer 168 may be disposed between at least the first electrode 170, the second semiconductor layer 140, and side surfaces of the active layer 130. This is to prevent electrical short between the first electrode 170 and the second semiconductor layer 140. The insulating layer 168 may include a nonconductive organic material or an inorganic material. For example, the insulating layer 168 may be formed of urethane, polyester, or acrylic, and may also be formed of a single layer or a multilayer structure. However, it is not limited thereto.

In addition, in order to further prevent a short, the insulating layer 168 may include the first electrode 170 and the second electrode 180 from the side surfaces of the first electrode 170, the second semiconductor layer 140, and the active layer 130. It may be arranged up to the same line as the upper surface of the).

Due to the insulating layer 168, short-circuit of the light emitting device 100 may be prevented, and flip chip type may improve reliability when mounted.

7 is a sectional view showing a light emitting device according to another embodiment.

Referring to FIG. 7, there is a difference in that the light emitting device 200 of the embodiment includes the insulating layer 268 as compared with the light emitting device of FIG. 3.

The insulating layer 268 may be disposed between at least the lower electrode 272, the second semiconductor layer 240, and the side surfaces of the active layer 230, between the upper electrode 274 and the second semiconductor layer 240.

The insulating layer 268 may be formed of a non-conductive organic material or an inorganic material. For example, the insulating layer 268 may be formed of urethane, polyester, or acrylic, and may also be formed of a single layer or a multilayer structure. However, it is not limited thereto.

In addition, in order to further prevent the short, it may extend to the same line as the upper surfaces of the first electrode 270 and the second electrode 280.

Due to the insulating layer 268, short-circuit of the light emitting device 200 can be prevented, and flip chip type can also improve reliability when mounted.

8 is a sectional view showing a light emitting device according to another embodiment.

Referring to FIG. 8, the light emitting device 100 of the embodiment further includes a reflective layer 160 as compared with the embodiment of FIG. 6, and there is a difference in the structure of the second electrode 180.

The reflective layer 160 may be disposed between the transparent electrode layer 150 and the second electrode 180. In this case, the second electrode 180 may be connected to the transparent electrode layer 150 through an opening of the reflective layer 160. That is, the transparent electrode layer 150 is disposed on the second semiconductor layer 140, the reflective layer 160 is disposed on the transparent electrode layer 150, and the second electrode 180 is disposed on the reflective layer 160. The second electrode 180 and the transparent electrode layer 150 are electrically connected to each other. However, the present invention is not limited thereto, and the second electrode 180 and the transparent electrode layer 150 may be connected in various ways.

By using the reflective layer 160 as described above, when the light emitting device 100 of the embodiment is used in a flip chip type, the luminous efficiency can be improved due to the large reflectivity of the reflective layer 160 and the stability of the mounting can be increased by enlarging the area of the electrode. And reliability can be ensured.

The reflective layer 160 may include a first layer 162 having a first refractive index and a second layer 164 having a second refractive index different from the first refractive index. That is, the reflective layer 160 may have a structure in which layers 162 and 164 having different refractive indices are alternately stacked repeatedly. For example, the first layer 162 may be a low refractive index layer, and the second layer 164 may be a high refractive index layer, but is not limited thereto.

On the other hand, when [lambda] is the wavelength of light generated in the active layer 130, n is the refractive index of the medium, and m is odd, the reflective layer 160 has a first layer 162 having a low refractive index with a thickness of mλ / 4n. The second layer 164 having a high refractive index is alternately repeatedly stacked to obtain a semiconductor stack structure in which a reflectance of 95% or more can be obtained in light having a specific wavelength range λ.

Accordingly, the first layer 162 having the low refractive index and the second layer 164 having the high refractive index may have a thickness of λ / 4 times the reference wavelength, and the thickness of each layer 163 and 164 may be 2 μm to 10 μm. It can be formed as.

In addition, each layer 163 and 164 forming the reflective layer 160 may be M _x O _y or M _x O _y N _z (M: Metal or Ceramics, O: Oxide, N: Nitride, X, Y, Z: constant). Can be configured.

For example, SiO ₂ having a refractive index of 1.4 or Al ₂ O ₃ having a refractive index of 1.6 may be used for the first layer 162 having a low refractive index, and TiO ₂ having a refractive index of 2 or more may be used for the second layer 164 having a high refractive index. Can be used, but is not limited thereto.

Meanwhile, the reflectance may be increased by increasing the refractive index of the medium between the first layer 162 having the low refractive index and the second layer 164 having the high refractive index.

Since the reflective layer 160 has a bandgap energy larger than the oscillation wavelength, absorption of light does not occur well, and thus light reflectivity is large.

The reflective layer 160 may be disposed from the top surface of the second semiconductor layer 140 to the top surface of the first semiconductor layer 120 along the side surface of the second semiconductor layer 140 and the side surface of the active layer 130. Therefore, the light extraction efficiency can be maximized.

9 is a sectional view showing a light emitting device according to another embodiment.

Referring to FIG. 9, the light emitting device 200 according to the embodiment further includes a reflective layer 260 compared to the embodiment of FIG. 7, and there is a difference in the structure of the second electrode 280.

The reflective layer 260 may be disposed between the transparent electrode layer 250 and the second electrode 280. In this case, the second electrode 280 may be connected to the transparent electrode layer 250 through an opening of the reflective layer 260. That is, the transparent electrode layer 250 is disposed on the second semiconductor layer 240, the reflective layer 260 is disposed on the transparent electrode layer 250, and the second electrode 280 is disposed on the reflective layer 260. The second electrode 280 and the transparent electrode layer 250 are electrically connected to each other. However, the present invention is not limited thereto, and the second electrode 280 and the transparent electrode layer 250 may be connected in various ways.

By using the reflective layer 260 as described above, when the light emitting device 200 of the embodiment is used in a flip chip type, the luminous efficiency can be improved due to the large reflectivity of the reflective layer 260 and at the same time, the mounting area is increased by increasing the area of the electrode. And reliability can be ensured.

The configuration or material of the reflective layer 260 is as described above.

10 is a view illustrating emission of light in a form in which a light emitting device according to the embodiment is flip chip bonded to a package substrate.

Referring to FIG. 10, a light emitting device according to an embodiment will now be described in detail by flip chip bonding to improve light extraction efficiency by the reflective layer 160.

Referring to FIG. 10, the light emitting device 100 flip-bonded on the package substrate 190 is illustrated. Meanwhile, conductor patterns 192 and 194 are formed on the package substrate 190, and the conductor patterns 192 and 194 are electrically connected to the second electrode 180 and the first electrode 170.

The reflective layer 160 formed as described above not only serves as a protective layer protecting the transparent electrode layer 150 or the first semiconductor layer 120, but also prevents light absorption and emits light toward the support member 110. The light extraction efficiency of the device can be improved.

That is, as shown in FIG. 10, the light generated from the active layer 130 is reflected by the reflective layer 160 to travel toward the support member 110 as a whole, thereby improving luminous efficiency of the flip chip type light emitting device. .

In addition, since the electrode can be formed in a wide structure, the structure can have stability and reliability of mounting, and can simultaneously have an effect of improving luminous efficiency.

11 is a cross-sectional view of a light emitting device package including a light emitting device according to the embodiment.

Referring to FIG. 11, the light emitting device package 500 according to the embodiment is installed on the body 531, the first electrode layer 538, the second electrode layer 539, and the body 531 installed on the body 531. The light emitting device 536 according to the exemplary embodiment may be electrically connected to the first electrode layer 538 and the second electrode layer 539. The light emitting device 536 may be connected to the first electrode layer 538 and the second electrode layer 539 by a flip chip method.

The body 531 may include a silicon material, a synthetic resin material, or a metal material, and an inclined surface may be formed around the light emitting device 536.

The first electrode layer 538 and the second electrode layer 539 are electrically separated from each other, and provide power to the light emitting device 536. In addition, the first electrode layer 538 and the second electrode layer 539 may increase light efficiency by reflecting light generated from the light emitting device 536, and discharge heat generated from the light emitting device 536 to the outside. It can also play a role.

On the other hand, the reflection layer 532 may be formed on the body 531 to more effectively concentrate the light emission of the light emitting device 536 in the front direction. In general, the reflective layer 532 may be formed of a metal such as silver (Ag) or aluminum (Al) having a high reflection coefficient. It is preferable to form the insulating layer 533 further.

In addition, a cavity 537 may be formed in the body 531 to mount the light emitting diode 536, and the cavity 537 may be filled with a molding member to surround and protect the light emitting diode 536. On the other hand, the molding member may include a phosphor to change the wavelength of the light emitted from the light emitting device (536).

Therefore, since the area of the electrode is large, stability and reliability increase when the light emitting device is mounted, and the light emission efficiency of the light emitting device can also be reduced to a minimum.

FIG. 12 is a perspective view showing a lighting device including a light emitting device according to an embodiment, and FIG. 13 is a sectional view showing a C-C 'sectional view of the lighting device of FIG.

12 and 13, the lighting device 600 may include a body 610, a cover 630 coupled to the body 610, and a finishing cap 650 positioned at opposite ends of the body 610 have.

A light emitting device module 640 is coupled to a lower surface of the body 610. The body 610 is electrically conductive so that heat generated from the light emitting device package 644 can be emitted to the outside through the upper surface of the body 610. [ And a metal material having an excellent heat dissipation effect.

The light emitting device package 644 may be mounted on the PCB 642 in a multi-color, multi-row manner to form an array. The light emitting device package 644 may be mounted at equal intervals or may be mounted with various spacings as required. As the PCB 642, MPPCB (Metal Core PCB) or FR4 material PCB can be used.

Since the light emitting device package 644 may have an improved heat dissipation function including an extended lead frame (not shown), reliability and efficiency of the light emitting device package 644 may be improved, and the light emitting device package 622 and the light emitting device may be improved. The service life of the lighting device 600 including the device package 644 may be extended.

The cover 630 may be formed in a circular shape so as to surround the lower surface of the body 610, but is not limited thereto.

The cover 630 protects the internal light emitting element module 640 from foreign substances or the like. The cover 630 may include diffusion particles so as to prevent glare of light generated in the light emitting device package 644 and uniformly emit light to the outside, and may include at least one of an inner surface and an outer surface of the cover 630 A prism pattern or the like may be formed on one side. Further, the phosphor may be applied to at least one of the inner surface and the outer surface of the cover 630.

On the other hand, since the light generated from the light emitting device package 644 is emitted to the outside through the cover 630, the cover 630 should have excellent light transmittance, and has sufficient heat resistance to withstand the heat generated from the light emitting device package 644. The cover 630 is preferably formed of a material including polyethylene terephthalate (PET), polycarbonate (PC), polymethyl methacrylate (PMMA), or the like. .

The finishing cap 650 is located at both ends of the body 610 and can be used to seal the power supply unit (not shown). In addition, the finishing cap 650 is provided with the power supply pin 652, so that the lighting apparatus 600 according to the embodiment can be used immediately without a separate device on the terminal from which the conventional fluorescent lamp is removed.

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

14, the liquid crystal display 700 may include a liquid crystal display panel 710 and a backlight unit 770 for providing light to the liquid crystal display panel 710 in an edge-light manner.

The liquid crystal display panel 710 can display an image using light provided from the backlight unit 770. The liquid crystal display panel 710 may include a color filter substrate 712 and a thin film transistor substrate 714 facing each other with a liquid crystal therebetween.

The color filter substrate 712 can realize the color of an image to be displayed through the liquid crystal display panel 710.

The thin film transistor substrate 714 is electrically connected to a printed circuit board 718 on which a plurality of circuit components are mounted via a driving film 717. The thin film transistor substrate 714 may apply a driving voltage provided from the printed circuit board 718 to the liquid crystal in response to a driving signal provided from the printed circuit board 718. [

The thin film transistor substrate 714 may include a thin film transistor and a pixel electrode formed as a thin film on another substrate of a transparent material such as glass or plastic.

The backlight unit 770 includes a light emitting element module 720 that outputs light, a light guide plate 730 that changes the light provided from the light emitting element module 720 into a surface light source and provides the light to the liquid crystal display panel 710, A plurality of films 750, 766, and 764 for uniformly distributing the luminance of light provided from the light guide plate 730 and improving vertical incidence and a reflective sheet (not shown) for reflecting the light emitted to the rear of the light guide plate 730 to the light guide plate 730 740).

The light emitting device module 720 may include a PCB substrate 722 for mounting a plurality of light emitting device packages 724 and a plurality of light emitting device packages 724 to form an array.

Meanwhile, the backlight unit 770 includes a diffusion film 766 for diffusing light incident from the light guide plate 730 toward the liquid crystal display panel 710, and a prism film 750 for condensing the diffused light to improve vertical incidence. It may be configured as), and may include a protective film 764 for protecting the prism film 750.

15 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. 14 are not repeatedly described in detail.

14 is a direct view, the liquid crystal display device 800 may include a liquid crystal display panel 810 and a backlight unit 870 for providing light to the liquid crystal display panel 810.

Since the liquid crystal display panel 810 is the same as that described in Fig. 14, the detailed description is omitted.

The backlight unit 870 includes a plurality of light emitting element modules 823, a reflective sheet 824, a lower chassis 830 in which the light emitting element module 823 and the reflective sheet 824 are accommodated, And a plurality of optical films 860. The diffuser plate 840 and the plurality of optical films 860 are disposed on the light guide plate 840. [

LED Module 823 A plurality of light emitting device packages 822 and a plurality of light emitting device packages 822 may be mounted to include a PCB substrate 821 to form an array.

The reflective sheet 824 reflects light generated from the light emitting device package 822 in a direction in which the liquid crystal display panel 810 is positioned, thereby improving light utilization efficiency.

Light generated in the light emitting element module 823 is incident on the diffusion plate 840 and an optical film 860 is disposed on the diffusion plate 840. The optical film 860 may include a diffusion film 866, a prism film 850, and a protective film 864.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of illustration, It can be seen that various modifications and applications are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

110: support member 120: first semiconductor layer
130: active layer 140: second semiconductor layer
150: translucent electrode layer 160: reflective layer
170: first electrode 180: second electrode

Claims

A light emitting structure including a first semiconductor layer, a second semiconductor layer, and an active layer between the first semiconductor layer and the second semiconductor layer;
A first electrode on which a portion of the upper surface of the first semiconductor layer is exposed while including the first region, and disposed on the first semiconductor layer of the first region; And
A second electrode disposed on the second semiconductor layer; / RTI >
The first electrode,
And a side surface of the second semiconductor layer and a side surface of the active layer spaced apart from each other by a first distance, and an upper surface having an area of 40% to 99% of the area of the second semiconductor layer.

The method of claim 1,
The first electrode,
A lower electrode connected on the first semiconductor layer and disposed to at least the height of the second semiconductor layer;
A top electrode connected to one end of the lower electrode, protruding inwardly of the light emitting structure to vertically overlap the second semiconductor layer and a partial region, and spaced apart from an upper surface of the second semiconductor layer,
The lower electrode,
The light emitting device of which the area seen from the upper side is 10% to 50% of the upper electrode.

The method of claim 1,
An area of the first region is 41% to 100% of the area of the second semiconductor layer.

The method of claim 2,
The area of the first region is 5% to 20% of the area of the second semiconductor layer.

The method of claim 2,
The lower electrode is disposed adjacent to the side of the light emitting structure.

The method according to claim 1 or 2,
Wherein the second electrode comprises:
A light emitting device having an area of 40% to 100% of the area of the second semiconductor layer.

The method according to claim 1 or 2,
The first electrode or the second electrode,
A light emitting device comprising a rectangle, a polygon or a circle viewed from above.

The method of claim 1,
The first region has a shape viewed from the upper side of the light emitting device comprises a rectangle, a polygon or a circle.

The method according to claim 1 or 2,
An upper surface of the first electrode and the second electrode is a light emitting device located on the same line.

The method of claim 1,
The light emitting device further comprises an insulating layer between at least the first electrode and the side surface of the second semiconductor layer and the active layer.

The method of claim 2,
And an insulating layer disposed between at least the lower electrode and the side surfaces of the second semiconductor layer and the active layer, between the upper electrode and the second semiconductor layer.

The method according to claim 10 or 11,
The upper surface of the insulating layer,
The light emitting device is disposed up to the same line as the upper surface of the first electrode and the second electrode.

The method according to claim 1 or 2,
A light emitting device comprising a translucent electrode layer disposed between the second semiconductor layer and the second electrode.

The method of claim 13,
A reflective layer between the translucent electrode layer and the second electrode,
The second electrode is connected to the light transmitting electrode layer through the opening of the reflective layer.

15. The method of claim 14,
And the reflective layer is disposed from an upper surface of the second semiconductor layer to an upper surface of the first semiconductor layer along side surfaces of the second semiconductor layer and side surfaces of the active layer.

15. The method of claim 14,
The reflective layer,
A light emitting device comprising a first layer having at least a first refractive index and a second layer having a second refractive index different from the first refractive index.

17. The method of claim 16,
The first layer and the second layer of the reflective layer alternately and repeatedly stacked light emitting device.

The method of claim 1,
A support member is disposed below the first semiconductor layer,
The lower portion of the support member includes a light emitting device including an uneven pattern for improving the light extraction efficiency.