KR20130007265A - Light emitting device and light emitting deivce package including the same - Google Patents

Abstract

PURPOSE: A light emitting device and a light emitting device package including the same are provided to improve light extraction efficiency by arranging a micro lens array with a fill-factor on the surface of the light emitting structure. CONSTITUTION: A junction layer(150), a reflection layer(140) and an ohmic layer(130) are successively formed on a support substrate(160). A light emitting structure(120) is formed on the ohmic layer. The light emitting structure includes a first conductive semiconductor layer(122), an active layer(124), and a second conductive semiconductor layer(126). A micro lens array(170) is formed on the second conductive semiconductor layer. A first electrode(190) is formed on the micro lens array.

Description

Light emitting device and light emitting device package including the same {Light emitting device and light emitting deivce package including the same}

The embodiment relates to a light emitting device package and improves light extraction efficiency of the light emitting device package.

Light emitting devices such as light emitting diodes (LEDs) and laser diodes (LDs) using semiconductors of Group 3-5 or 2-6 compound semiconductor materials of semiconductors have been developed through the development of thin film growth technology and device materials. Various colors such as green, blue, and ultraviolet light can be realized, and efficient white light can be realized by using fluorescent materials or combining colors, and low power consumption, semi-permanent life, and quicker than conventional light sources such as fluorescent and incandescent lamps can be realized. It has the advantages of response speed, safety and environmental friendliness.

Therefore, the light emitting diode can replace a light emitting diode backlight, a fluorescent lamp or an incandescent bulb which replaces a cold cathode fluorescent lamp (CCFL) constituting a backlight module of an optical communication means, a backlight of a liquid crystal display (LCD) display device. Applications are expanding to white light emitting diode lighting devices, automotive headlights and traffic lights.

The embodiment aims to improve the light extraction efficiency of the light emitting device package.

Embodiments include a light emitting structure including a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer; And a microlens array disposed on the light emitting structure, wherein the microlens array provides at least one microlens having different curvatures.

Microlenses having different curvatures may be disposed in any one of a horizontal direction, a vertical direction, and a diagonal direction.

The micro lens array may include at least one micro lens having a different height of the base surface.

The micro lens array may include at least one micro lens having a different size.

The peaks of each micro lens in the micro lens array may be the same.

Within the micro lens array, each micro lens can be arranged as a function of a polynomial with different orders.

The micro lens array may include at least one micro lens having a different height.

Another embodiment includes a package body; A first lead frame and a second lead frame disposed on the package body; A light emitting device according to any one of claims 1 to 6 disposed on the package body and electrically connected to a first lead frame and a second lead frame; And a molding unit surrounding side and top surfaces of the light emitting device.

The micro lens array may be disposed on the molding part.

The light emitting device package may further include a lens disposed on the molding part to change a path of light emitted from the light emitting device, and the micro lens array may be disposed on the lens.

In the light emitting device and the light emitting device package according to the embodiment, a microlens array having a complete filling rate may be disposed on a surface of the light emitting structure, etc., to increase light extraction efficiency.

1 is a view showing an embodiment of a light emitting device,
2 is a view showing another embodiment of a light emitting device;
3 is a view showing an embodiment of a light emitting device package,
4 is a cross-sectional view of the microlens array of FIGS. 1 to 3;
5 is a plan view of the microlens array of FIGS. 1 to 3;
6 is a diagram illustrating the structure of each micro lens in the micro lens array of FIGS. 1 to 3;
7 is a diagram illustrating an arrangement of micro lenses in the micro lens array of FIGS. 1 to 3;
8 to 12 is a view showing an embodiment of a method of manufacturing a light emitting device,
13 is an exploded perspective view of an embodiment of a lighting device including a light emitting device package according to the embodiment;
14 is a view illustrating a display device including a light emitting device package according to an embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

In the description of the embodiment according to the present invention, when described as being formed on the "on or under" of each element, the (up) or down (on) or under) includes both two elements being directly contacted with each other or one or more other elements are formed indirectly between the two elements. Also, when expressed as "on or under", it may include not only an upward direction but also a downward direction with respect to one element.

The thickness and size of each layer in the drawings are exaggerated, omitted, or schematically shown for convenience and clarity of explanation. In addition, the size of each component does not necessarily reflect the actual size.

1 is a view showing an embodiment of a light emitting device.

The light emitting device 100 according to the embodiment includes a bonding layer 150, a reflective layer 140, an ohmic layer 130, a light emitting structure 120, and a micro lens array on a conductive metal support 160. Array 170).

Since the conductive support substrate 160 may serve as a second electrode, a metal having excellent electrical conductivity may be used, and a metal having high thermal conductivity may be used because it must be able to sufficiently dissipate heat generated when the light emitting device is operated.

The conductive support substrate 160 may be made of a material selected from the group consisting of molybdenum (Mo), silicon (Si), tungsten (W), copper (Cu), and aluminum (Al) or an alloy thereof. , Gold (Au), copper alloy (Cu Alloy), nickel (Ni), copper-tungsten (Cu-W), carrier wafers (e.g. GaN, Si, Ge, GaAs, ZnO, SiGe, SiC, SiGe, Ga ₂ O _3, etc.) may be optionally included.

In addition, the conductive support substrate 160 may have a mechanical strength enough to be separated into a separate chip through a scribing process and a breaking process without bringing warpage to the entire nitride semiconductor. have.

The bonding layer 150 may combine the reflective layer 140 and the conductive support substrate 160, and the reflective layer 140 may function as an adhesion layer. The bonding layer (150) is composed of gold (Au), tin (Sn), indium (In), aluminum (Al), silicon (Si), silver (Ag), nickel (Ni) and copper (Cu) It may be formed of a material selected from or alloys thereof.

The reflective layer 140 may be about 2500 angstroms thick. The reflective layer 140 may be formed of a metal layer including aluminum (Al), silver (Ag), nickel (Ni), platinum (Pt), rhodium (Rh), or an alloy containing Al, Ag, Pt, or Rh. have. Aluminum or silver may effectively reflect light generated from the active layer 124 to greatly improve the light extraction efficiency of the light emitting device.

Since the light emitting structure 120, in particular, the second conductive semiconductor layer 126 has a low impurity doping concentration and a high contact resistance, and thus may not have good ohmic characteristics, the ohmic layer 130 may be improved. Transparent electrodes and the like can be formed.

The ohmic layer 130 may be about 200 angstroms thick. The ohmic layer 130 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), and indium gallium tin (IGTO). oxide), aluminum zinc oxide (AZO), antimony tin oxide (ATO), gallium zinc oxide (GZO), IZO (IZO Nitride), AGZO (Al-Ga ZnO), IGZO (In-Ga ZnO), ZnO, IrOx, RuOx, NiO, RuOx / ITO, Ni / IrOx / Au, and Ni / IrOx / Au / ITO, Ag, Ni, Cr, Ti, Al, Rh, Pd, Ir, Sn, In, Ru, Mg, Zn, Pt At least one of Au, Hf, and the like may be formed, and the material is not limited thereto.

The light emitting structure 120 is formed on the first conductivity type semiconductor layer 122 and the first conductivity type semiconductor layer 122 and the active layer 124 for emitting light and the second layer formed on the active layer 124. And a conductive semiconductor layer 126.

The first conductivity type semiconductor layer 122 may be implemented as a group III-V compound semiconductor doped with a first conductivity type dopant, and when the first conductivity type semiconductor layer 122 is an N-type semiconductor layer, The first conductive dopant may be an N-type dopant and may include Si, Ge, Sn, Se, or Te, but is not limited thereto.

The first conductive semiconductor layer 122 may be formed of a semiconductor material having a composition formula of Al _x In _y Ga _(1-xy) N (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1). It may include. The first conductive semiconductor layer 122 may be formed of any one or more of GaN, InN, AlN, InGaN, AlGaN, InAlGaN, AlInN, AlGaAs, InGaAs, AlInGaAs, GaP, AlGaP, InGaP, AlInGaP, InP.

In the active layer 124, electrons injected through the first conductive semiconductor layer 122 and holes injected through the second conductive semiconductor layer 126 formed thereafter meet each other to form an energy band unique to the active layer (light emitting layer) material. The layer may emit light having energy determined by the light, and the light emitted from the active layer 124 may emit light in the ultraviolet region in addition to the visible region.

The active layer 124 may be formed of at least one of a single quantum well structure, a multi quantum well structure (MQW), a quantum-wire structure, or a quantum dot structure. For example, the active layer 124 may be formed by injecting trimethyl gallium gas (TMGa), ammonia gas (NH ₃ ), nitrogen gas (N ₂ ), and trimethyl indium gas (TMIn) to form a multi-quantum well structure. It is not limited to this.

The well layer / barrier layer of the active layer 124 is formed of one or more pair structures of InGaN / GaN, InGaN / InGaN, GaN / AlGaN, InAlGaN / GaN, GaAs (InGaAs) / AlGaAs, GaP (InGaP) / AlGaP. But it is not limited thereto. The well layer may be formed of a material having a lower band gap than the band gap of the barrier layer.

A conductive cladding layer (not shown) may be formed on or under the active layer 124. The conductive clad layer may be formed of an AlGaN-based semiconductor, and may have a higher band gap than the band gap of the active layer 164.

The second conductive type semiconductor layer 126 is a second conductive type dopant is doped III-V compound semiconductor, for example _{-5, In x Al y Ga 1 -x-} y N (0≤x≤1, 0≤y≤ And 1, 0 ≦ x + y ≦ 1). When the second conductive semiconductor layer 126 is a P-type semiconductor layer, the second conductive dopant may include Mg, Zn, Ca, Sr, Ba, and the like as a P-type dopant.

Meanwhile, the first conductive semiconductor layer 122 may include a p-type semiconductor layer, and the second conductive semiconductor layer 126 may include an n-type semiconductor layer.

The first electrode 190 may be formed on a surface of the light emitting structure 120, among aluminum (Al), titanium (Ti), chromium (Cr), nickel (Ni), copper (Cu), and gold (Au). It may be formed in a single layer or a multi-layer structure, including at least one.

In addition, irregularities (not shown) are formed on the surface of the light emitting structure 120, that is, the surface of the first conductivity-type semiconductor layer 122, thereby increasing light extraction efficiency. In addition, the microlens array 170 may be formed on the surface of the light emitting structure 120 to widen the light emission angle of the light emitting device.

4 is a cross-sectional view of the microlens array of FIGS. 1 to 3, FIG. 5 is a plan view of the microlens array of FIGS. 1 to 3, and FIG. 6 is a microlens array of FIGS. Is a view showing the structure of each micro lens, Figure 7 is a view showing the arrangement of the micro lens in the micro lens array of Figs.

Hereinafter, the structure of the micro lens array will be described in detail with reference to FIGS. 4 to 7. The number of micro lenses included in the micro lens array is not limited to the description.

In the microlens, a plurality of microlenses are disposed on a base layer (not shown), and the curvature of each microlens may not be the same. In FIG. 4, the microlens array 170 includes five microlenses a, b, c, d, and e, and the curvatures of the microlenses a, b, c, d, and e are different from each other. It is.

In FIG. 5, four micro lenses a, b, c, and d are disposed in the micro lens array 170, and sizes of the micro lenses a, b, c, and d are different from each other. have. Here, the size of the micro lens means the diameter of the circular micro lens (a, b, c, d), and if the micro lens is a square or polygon may mean the length of one side or the diagonal.

In FIG. 5, the space between each of the microlenses a, b, c, d with curvature may be a base layer, indicated by hatched lines.

In FIG. 6 the surfaces of three adjacent micro lenses a, b, c are shown. The line indicated by the dotted line is the surface of each micro lens a, b, c, and the solid line is an imaginary line for comparing the shape of each micro lens a, b, c.

Each of the microlenses a, b, and c has the same highest point, but the lowest point is different and the curvature is different. The heights h _a , h _b , h _c from the lowest point to the highest point of the microlenses a, b, and c may also be different. Here, the lowest point of the microlens refers to the lowest height of each microlens (a, b, c). In FIG. 5, the lowest point is a circle, and a virtual plane connecting the lowest point may be referred to as a base plane.

7 shows an arrangement of micro lenses a to k having different curvatures to sizes. Each of the micro lenses a to k may be disposed in the horizontal direction x, the vertical direction y, and the diagonal direction z.

In FIG. 7, the microlenses a to k are not arranged in a constant order in the horizontal direction x, the vertical direction y, and the diagonal direction z, and according to a function of a polynomial having different orders. Can be arranged.

For example, the position of each micro lens in the horizontal direction x may be determined as a function of x = a ₁ x ⁿ + a ₂ x ^{n −1} + ... + a _n . Here, n is an integer of 1 or more, the position of the microlens is determined according to the change of the a, x value, and the center region of the microlens is located at the position of the determined value.

By arranging a plurality of microlenses having different curvatures and sizes as described above according to the polynomial, the microlens array may have a fill factor. The dense microlens array emits light from the surface of the light emitting device. It is possible to improve the emission efficiency of the light.

In addition, a passivation layer 180 is formed on a side surface of the light emitting structure 120, and may also be formed on a side surface of the micro lens array 170.

The passivation layer 180 may be made of an insulating material, and the insulating material may be made of an oxide or nitride which is non-conductive. As an example, the passivation layer 180 may be formed of a silicon oxide (SiO ₂ ) layer, an oxynitride layer, and an aluminum oxide layer.

2 is a view showing another embodiment of a light emitting device.

FIG. 2 illustrates a horizontal light emitting device. The first conductive semiconductor is mesa-etched to a part of the second conductive semiconductor layer 126, the active layer 124, and a portion of the first conductive semiconductor layer 122. A portion of layer 122 is exposed. That is, when the substrate 110 is formed of an insulating material, it is to secure a space where an electrode is to be formed to supply a current to a portion of the first conductivity-type semiconductor layer 162.

A buffer layer 115 may be formed between the substrate 110 and the light emitting structure 120. The buffer layer 115 may have a lattice mismatch and thermal expansion coefficient of a material between the light emitting structure 120 and the substrate 110, which will be described later. To alleviate the difference. The material of the buffer layer 115 may be formed of at least one of Group III-V compound semiconductors, for example, GaN, InN, AlN, InGaN, AlGaN, InAlGaN, and AlInN.

The micro lens array 170 is disposed on the light emitting structure 120, and the detailed configuration thereof is as described above.

The second electrode 195 and the first electrode 190 are disposed on each of the second conductive semiconductor layer 126 and the exposed first conductive semiconductor layer 122. The first electrode 190 and the second electrode 195 include at least one of aluminum (Al), titanium (Ti), chromium (Cr), nickel (Ni), copper (Cu), and gold (Au). It may be formed in a single layer or a multilayer structure.

3 is a view showing an embodiment of a light emitting device package.

The light emitting device package 200 according to the embodiment includes a body 210 including a cavity, a first lead frame 221 and a second lead frame 222 installed on the body 210, and the body. The light emitting device 100 according to the above-described embodiments installed in the 210 and electrically connected to the first lead frame 221 and the second lead frame 222, and the molding part 250 formed in the cavity. It includes.

The body 210 may include a PPA resin, a silicon material, a synthetic resin material, or a metal material. When the body 210 is made of a conductive material such as a metal material, an insulating layer is coated on the surface of the body 210 to prevent an electrical short between the first and second lead frames 221 and 222 .

The first lead frame 221 and the second lead frame 222 are electrically separated from each other, and supplies a current to the light emitting device 100. In addition, the first lead frame 221 and the second lead frame 222 may increase the light efficiency by reflecting the light generated by the light emitting device 100, heat generated by the light emitting device 100 Can be discharged to the outside.

The light emitting device 100 may be installed on the body 210 or on the first lead frame 221 or the second lead frame 222. In the present exemplary embodiment, the first lead frame 221 and the light emitting device 100 are energized through the conductive adhesive layer 230, and the second lead frame 222 and the light emitting device 100 are connected through a wire 240. It is. The light emitting device 100 may be connected to the lead frames 221 and 222 by a flip chip method or a die bonding method in addition to the wire bonding method.

The molding part 250 may surround and protect the light emitting device 100. In addition, a phosphor 260 is included in the molding part 250, and the phosphor 260 may be conformally coated in a separate layer from the molding part 250.

The light of the first wavelength region emitted from the light emitting device 100 is excited by the phosphor 260 and converted into the light of the second wavelength region, and the light of the second wavelength region passes through the lens (not shown). The light path can be changed.

In addition, a micro lens array 270 is disposed on the molding unit 2500, and the configuration of the micro lens array is the same as described above. May be provided, wherein the micro lens array may be disposed on the surface of the lens.

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. Such a light emitting device package, a substrate, and an optical member can function as a light unit. Another embodiment may be implemented as a display device, an indicator device, or a lighting system including the semiconductor 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. .

When the microlens array is disposed on the molding part of the light emitting device package or the surface of the lens, the microlens array may be coupled onto the completed light emitting device package.

8 to 12 illustrate an embodiment of a method of manufacturing a light emitting device.

First, as shown in FIG. 8, a light emitting structure including a buffer layer 115, a first conductivity type semiconductor layer 122, an active layer 124, and a second conductivity type semiconductor layer 126 on a substrate 110. Grow 126.

The light emitting structure 126 may be formed of, for example, a metal organic chemical vapor deposition (MOCVD), a chemical vapor deposition (CVD), a plasma chemical vapor deposition (PECVD), or a molecular beam. Molecular Beam Epitaxy (MBE), Hydride Vapor Phase Epitaxy (HVPE), etc. may be formed using, but is not limited thereto.

The substrate 110 may include a conductive substrate or an insulating substrate. For example, at least one of sapphire (Al ₂ O ₃ ), SiC, GaAs, GaN, ZnO, Si, GaP, InP, Ge, and Ga ₂ 0 ₃ may be used. Can be. An uneven structure may be formed on the substrate 110, but is not limited thereto. Impurities on the surface may be removed by wet cleaning the substrate 110.

A buffer layer (not shown) may be grown between the light emitting structure and the substrate 110 to alleviate the difference in lattice mismatch and thermal expansion coefficient of the material. The material of the buffer layer may be formed of at least one of Group III-V compound semiconductors such as GaN, InN, AlN, InGaN, AlGaN, InAlGaN, and AlInN. An undoped semiconductor layer may be formed on the buffer layer, but the present invention is not limited thereto.

The light emitting structure may be grown by vapor deposition such as metal organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), and hydraulic vapor phase epitaxy (HVPE).

The composition of the first conductive semiconductor layer 122 is the same as described above, and using N, using a chemical vapor deposition method (CVD), molecular beam epitaxy (MBE) or sputtering or hydroxide vapor phase epitaxy (HVPE), etc. A type GaN layer can be formed. In addition, the first conductive semiconductor layer 110 may include a silane including n-type impurities such as trimethyl gallium gas (TMGa), ammonia gas (NH ₃ ), nitrogen gas (N ₂ ), and silicon (Si) in the chamber. The gas SiH ₄ may be injected and formed.

The active layer 124 has the same composition as described above. For example, the trimethyl gallium gas (TMGa), ammonia gas (NH ₃ ), nitrogen gas (N ₂ ), and trimethyl indium gas (TMIn) are injected to form A quantum well structure may be formed, but is not limited thereto.

The second conductivity-type semiconductor layer 126 has the same composition as described above, and in the chamber, p such as trimethyl gallium gas (TMGa), ammonia gas (NH ₃ ), nitrogen gas (N ₂ ), and magnesium (Mg) Bicetyl cyclopentadienyl magnesium (EtCp ₂ Mg) {Mg (C ₂ H ₅ C ₅ H ₄ ) ₂ } containing a type impurity may be implanted to form a p-type GaN layer, but is not limited thereto.

As illustrated in FIG. 9, an ohmic layer 130 and a reflective layer 140 may be formed on the light emitting structure 120. The composition of the ohmic layer 130 and the reflective layer 140 is as described above, and may be formed by sputtering or electron beam deposition.

When ITO is used for the ohmic layer 130 when the active layer 124 emits ultraviolet rays, the UV transmission efficiency may not be good, and the ohmic layer 130 may be formed of Ni / Au.

10, the bonding layer 150 and the conductive support substrate 160 may be formed on the reflective layer 140. The conductive support substrate 160 may be formed using an electrochemical metal deposition method, a bonding method using an etchant metal, or a separate bonding layer 160.

Then, the substrate 110 is separated as shown in FIG. 11. The substrate 110 may be removed by a laser lift off (LLO) method using an excimer laser or the like, or may be a method of dry and wet etching.

For example, when the laser lift-off method focuses and irradiates excimer laser light having a predetermined wavelength in the direction of the substrate 110, heat energy is applied to the interface between the substrate 110 and the light emitting structure 120. As the interface is concentrated and separated into gallium and nitrogen molecules, separation of the substrate 110 and the buffer layer 115 occurs at a portion where the laser light passes.

Although not shown, an uneven structure may be formed by etching the surface of the light emitting structure 120, that is, the surface of the first conductivity-type semiconductor layer 122, and depositing a passivation layer on the side of the light emitting structure 120, The first electrode may be formed on the surface of the light emitting structure 120.

In FIG. 12, the micro lens array MLA is formed on the surface of the light emitting structure 120, that is, on the first conductivity type semiconductor layer 122. In this case, the material of the micro lens array may be deposited to have a pattern on the light emitting structure 120.

The light emitting device according to the above process can increase the light emission efficiency of the microlens array on the surface of the light emitting structure, and the light extraction efficiency by the microlens array having a full filling rate without forming the uneven structure on the surface of the light emitting structure. Can be raised.

Hereinafter, an illumination device and a backlight unit will be described as an embodiment of a lighting system in which the above-described light emitting device package is disposed.

FIG. 13 is a diagram illustrating an embodiment of a lighting apparatus in which a light emitting device package is disposed.

The lighting apparatus according to the embodiment includes a light source 600 for projecting light, a housing 400 in which the light source 600 is embedded, a heat dissipation part 500 for dissipating heat from the light source 600, and the light source 600. And a holder 700 for coupling the heat dissipation part 500 to the housing 400.

The housing 400 includes a socket coupling part 410 coupled to an electric socket and a body part 420 connected to the socket coupling part 410 and having a light source 600 embedded therein. One air flow port 430 may be formed in the body portion 420.

A plurality of air flow port 430 is provided on the body portion 420 of the housing 400, wherein the air flow port 430 is composed of one air flow port, or a plurality of flow ports as shown in the radial arrangement Various other arrangements are also possible.

The light source 600 includes a plurality of light emitting device packages 650 on the circuit board 610. Here, the circuit board 610 may be inserted into the opening of the housing 400, and may be made of a material having a high thermal conductivity to transmit heat to the heat dissipating unit 500, as described later.

A holder 700 is provided below the light source, and the holder 700 may include a frame and another air flow port. In addition, although not shown, an optical member may be provided under the light source 100 to diffuse, scatter, or converge light projected from the light emitting device package 150 of the light source 100.

13 is a diagram illustrating an embodiment of a display device in which a light emitting device package is disposed.

As shown, the display device 800 according to the present exemplary embodiment is disposed in front of the light source modules 830 and 835, the reflector 820 on the bottom cover 810, and the reflector 820. The light guide plate 840 for guiding light emitted from the front of the display device, the first prism sheet 850 and the second prism sheet 860 disposed in front of the light guide plate 840, and the second prism sheet ( A panel 870 disposed in front of the panel 860, an image signal output circuit 872 connected to the panel 870 and supplying an image signal to the panel 870, and a color disposed in the first half of the panel 870; And a filter 880.

The light source module includes the above-described light emitting device package 835 on the circuit board 830. Here, the PCB 830 may be used as the circuit board 830, and the light emitting device package 835 is as described with reference to FIG. 13.

The bottom cover 810 may accommodate components in the display device 800. The reflective plate 820 may be provided as a separate component as shown in the drawing, or may be disposed on the rear surface of the light guide plate 840, or The bottom cover 810 may be provided in the form of a coating with a highly reflective material.

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 840 scatters light emitted from the light emitting device package module so that the light is uniformly distributed over the entire screen area of the LCD. Accordingly, the light guide plate 840 is made of a material having a good refractive index and transmittance. The light guide plate 840 may be formed of poly methylmethacrylate (PMMA), polycarbonate (PC), or polyethylene (PE). In addition, the light guide plate may be omitted, and thus an air guide method in which light is transmitted in the space on the reflective sheet 820 may be possible.

The first prism sheet 850 is formed of a translucent and elastic polymer material on one surface of the support film, and the polymer may have a prism layer in which a plurality of three-dimensional structures are repeatedly formed. Here, the plurality of patterns may be provided in the stripe type and the valley repeatedly as shown.

In the second prism sheet 860, the direction of the floor and the valley of one surface of the support film may be perpendicular to the direction of the floor and the valley of one surface of the support film in the first prism sheet 850. This is to evenly distribute the light transmitted from the light source module and the reflective sheet in all directions of the panel 870.

In the present embodiment, the first prism sheet 850 and the second prism sheet 860 form an optical sheet, which is composed of another combination, for example, a micro lens array or a diffusion sheet and a micro lens array. Or a combination of one prism sheet and a micro lens array.

The liquid crystal display panel may be disposed on the panel 870, and may be provided with another type of display device that requires a light source.

The panel 870 is a state in which the liquid crystal is located between the glass body and the polarizing plate is placed on both glass bodies in order to use the polarization of light. Here, the liquid crystal has an intermediate property between a liquid and a solid, and liquid crystals, which are organic molecules having fluidity like a liquid, are regularly arranged like crystals. The liquid crystal has a structure in which the molecular arrangement is changed by an external electric field And displays an image.

A liquid crystal display panel used in a display device is an active matrix type, and a transistor is used as a switch for controlling a voltage supplied to each pixel.

The front surface of the panel 870 is provided with a color filter 880 to transmit the light projected from the panel 870, only the red, green and blue light for each pixel can represent an image.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood 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.

100 light emitting element 110 substrate
120: light emitting structure 122, 126: first and second conductivity type semiconductor layer
124: active layer 130: ohmic layer
140: reflective layer 150: bonding layer
160: conductive support substrate 170: micro lens array
180: passivation layer 190, 195: first and second electrodes
200: light emitting device package 210: body
221, 222: first and second lead frame 230: conductive adhesive layer
240 wire 250 molding part
260 phosphor
400 housing 500 heat dissipation unit
600: light source 700: holder
800: display device 810: bottom cover
820: reflector 830: circuit board module
840: Light guide plate 850, 860: First and second prism sheet
870 panel 880 color filter

Claims (10)

A light emitting structure including a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer;
A micro lens array disposed on the light emitting structure;
The microlens array includes at least one microlens having different curvatures. The method of claim 1,
The microlenses having different curvatures are disposed in any one of a horizontal direction, a vertical direction and a diagonal direction. The method of claim 1,
The microlens array includes at least one microlens having a different base surface height. The method of claim 1,
The microlens array includes at least one microlens having different sizes. The method of claim 1,
The highest point of each micro lens in the micro lens array is the same light emitting device. The method of claim 1,
Within the microlens array, each microlens is arranged according to a function of a polynomial having a different order, where the function of the polynomial is x = a ₁ x ⁿ + a ₂ x ^{n -1} + ... + a _n Light emitting element. Where n is an integer greater than or equal to 1 The method of claim 1,
The microlens array includes at least one microlens having a different height. Package body;
A first lead frame and a second lead frame disposed on the package body;
A light emitting device according to any one of claims 1 to 7 disposed on the package body and electrically connected to a first lead frame and a second lead frame; And
Light emitting device package comprising a molding unit surrounding the side and the upper surface of the light emitting device. The method of claim 8,
The micro lens array is a light emitting device package disposed on the molding portion. The method of claim 8,
And a lens disposed on the molding part to change a path of light emitted from the light emitting device, wherein the microlens array is disposed above the lens.

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