Light emitting device chip, light emitting device package

Disclosed are a light emitting device chip, a light emitting device package, and a lighting system. The light emitting device chip includes a light emitting structure including a first conductive semiconductor layer, a second conductive semiconductor layer and an active layer interposed between the first and second conductive semiconductor layers; a transmittive layer on the light emitting structure; and a luminescence material layer on the transmittive layer, wherein the luminescence material layer includes a pattern, which does not expose the transmittive layer, partially exposes the transmittive layer or partially exposes the transmittive layer and the light emitting structure.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority of Korean Patent Application No. 10-2010-0003544 Filed Jan. 14, 2010, which is hereby incorporated by reference.

BACKGROUND

The embodiment relates to a light emitting device chip, a light emitting device package, and a lighting system.

A light emitting device includes a p-n junction diode having a characteristic of converting electric energy into light energy. The p-n junction diode can be formed by combining group III-V elements of the periodic table. The light emitting device can represent various colors by adjusting the compositional ratio of compound semiconductors.

Meanwhile, in order to realize a white light emitting device package, light emitting devices representing red, green and blue colors, which are three primary colors of light, are combined with each other, the yellow luminescence material (YAG or TAG) is added to the blue light emitting device, or red/green/blue luminescence materials are employed in the UV light emitting device.

Meanwhile, according to the white light emitting device package using the luminescence materials of the related art, a light emitting device chip is positioned on a bottom surface of a reflective cup, an encapsulating material mixed with the luminescence material is filled in the reflective cup, and the white light is formed by mixing the light having a first wavelength generated from the light emitting device chip with the light colliding with the luminescence material and having a wavelength longer than the first wavelength.

However, according to the related art, the luminescence material mixed with the encapsulating material is filled in the reflective cup, so the reflective cup must be provided in the package.

In addition, according to the related art, the light emitting device is adjacent to a luminescence material layer, so heat generated from the light emitting device is transferred to the luminescence material layer, thereby degrading the wavelength conversion efficiency of the luminescence material layer.

Further, according to the related art, particles of the luminescence material may sink during the process, so the concentration of the luminescence material may vary depending on the process time.

In addition, according to the related art, the color temperature variation may occur depending on the viewing angles.

BRIEF SUMMARY

The embodiment provides a light emitting device chip, which can spontaneously generate white light by providing a luminescence material layer on a light emitting surface, a light emitting device package, and a lighting system.

A light emitting device chip according to the embodiment may include a light emitting structure including a first conductive semiconductor layer, a second conductive semiconductor layer and an active layer interposed between the first and second conductive semiconductor layers; a transmittive layer on the light emitting structure; and a luminescence material layer on the transmittive layer, wherein the luminescence material layer includes a pattern, which does not expose the transmittive layer, partially exposes the transmittive layer or partially exposes the transmittive layer and the light emitting structure.

A light emitting device chip according to the embodiment may include a light emitting structure including a first conductive semiconductor layer, a second conductive semiconductor layer and an active layer interposed between the first and second conductive semiconductor layers; a transmittive layer on the light emitting structure; and a luminescence material layer on the transmittive layer, wherein the transmittive layer is formed on a top surface and lateral sides of the light emitting structure.

In addition, a light emitting device package according to the embodiment may include a package body; at least one electrode layer on the package body; and the light emitting device and electrically connected to the electrode layer.

In addition, a lighting system according to the embodiment may include a light emitting module including a substrate and a light emitting device package on the substrate, wherein the light emitting device package includes a package body, third and fourth electrode layers on the package body and a light emitting device package electrically connected to the third and fourth electrode layers.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Hereinafter, a light emitting device chip, a light emitting device package, and a lighting system according to the embodiments will be described in detail with reference to accompanying drawings.

In the description of embodiments, it will be understood that when a layer (or film) is referred to as being ‘on’ another layer or substrate, it can be directly on another layer or substrate, or intervening layers may also be present. Further, it will be understood that when a layer is referred to as being ‘under’ another layer, it can be directly under another layer, and one or more intervening layers may also be present. In addition, it will also be understood that when a layer is referred to as being ‘between’ two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present.

FIG. 1is a sectional view showing a light emitting device chip according to the first embodiment.

The light emitting device100according to the embodiment may include a light emitting structure110, a transmittive layer130on the light emitting structure110and a luminescence material layer140on the transmittive layer130.

According to the light emitting device chip of the embodiment, the luminescence material layer140may be provided in the light emitting device chip, so that the light emitting device chip can spontaneously generate white light.

According to the embodiment, the transmittive layer130may have lower thermal conductivity and higher light transmittive property than the luminescence material layer140.

In addition, according to the embodiment, the transmittive layer130having low thermal conductivity and high light transmittive property may be interposed between a light emitting surface of the light emitting device chip and the luminescence material layer140, so that heat generated from the light emitting surface of the light emitting structure110can be restricted from being transferred to the luminescence material layer140, thereby improving the wavelength conversion efficiency of the luminescence material.

The transmittive layer130may include silicon gel, but the embodiment is not limited thereto.

The transmittive layer130may have a thickness of about 2 μm to 200 μm, but the embodiment is not limited thereto. For instance, the transmittive layer130may have a thickness of about 2 μm or above thicker than a first electrode120formed on the light emitting structure110, but the embodiment is not limited thereto. In addition, the transmittive layer130may have a thickness of about 200 μm or below corresponding to the half of the total height of the light emitting device chip, but the embodiment is not limited thereto.

The transmittive layer130may be formed on a top surface and a lateral side of the light emitting structure110, but the embodiment is not limited thereto. For instance, the transmittive layer130may be exclusively formed on the top surface or the lateral side of the light emitting structure110.

The luminescence material layer140may have a thickness of about 5 μm to 500 μm, but the embodiment is not limited thereto. For instance, the luminescence material layer140may have a thickness of about 5 μm or above to convert blue light into yellow light or may have a thickness of about 500 μm or below by taking the size of the light emitting device chip into consideration, but the embodiment is not limited thereto.

According to the embodiment, the first electrode120may include a line pattern having an electric connection and a part of the first electrode120may be electrically connected to an exposed pad electrode (not shown).

According to the embodiment, the luminescence material layer140is provided in the light emitting device chip, so that the light emitting device chip can spontaneously generate white light.

According to the embodiment, a lateral width of the light emitting structure110may be smaller than that of the second electrode105, but the embodiment is not limited thereto.

In addition, according to the embodiment, the heat generated from the light emitting device chip can be restricted from being transferred to the luminescence material layer140, thereby improving the wavelength conversion efficiency of the luminescence material layer140.

Hereinafter, the method for manufacturing the light emitting device chip according to the first embodiment will be described with reference toFIGS. 2 to 5.

As shown inFIG. 2, the light emitting device chip according to the first embodiment may include the light emitting structure110formed on the second electrode105. The second electrode105may include at least one of an ohmic layer, a reflective layer, a bonding layer and a conductive substrate.

The light emitting structure110may include a second conductive semiconductor layer116, an active layer114and a first conductive semiconductor layer112.

Hereinafter, the method of forming the light emitting structure110on the second electrode105will be described.

First, a first substrate (not shown) is prepared. The first substrate may include a sapphire substrate or a SiC substrate, but the embodiment is not limited thereto.

Then, the light emitting structure110including the first conductive semiconductor layer112, the active layer114and the second conductive semiconductor layer116is formed on the first substrate.

The first conductive semiconductor layer112may include an N type GaN layer, which is formed through the CVD, MBE, sputtering or HYPE. In addition, the first conductive semiconductor layer112can be formed by injecting trimethyl gallium (TMGa) gas, ammonia (NH3) gas, nitrogen (N2) gas and silane (SiH4) gas including n type impurities, such as silicon, into the chamber.

According to the embodiment, an undoped semiconductor layer (not shown) is formed on the first substrate (not shown) and the first conductive semiconductor layer112is formed on the undoped semiconductor layer in order to attenuate the lattice mismatch between the first substrate and the light emitting structure.

The active layer114may include at least one of a single quantum well structure, a multiple quantum well (MQW) structure, a quantum wire structure or a quantum dot structure. For instance, the active layer114can be formed with the MQW structure by injecting TMGa gas, NH3gas, N2gas, and trimethyl indium (TMIn) gas, but the embodiment is not limited thereto.

The active layer114may have a well/barrier layer including at least one of InGaN/GaN, InGaN/InGaN, AlGaN/GaN, InAlGaN/GaN, GaAs/AlGaAs (InGaAs) and GaP/AlGaP (InGaP), but the embodiment is not limited thereto. The well layer may include a material having the band gap energy lower than that of the barrier layer.

The conductive clad layer can be formed on and/or under the active layer114. The conductive clad layer may include an AlGaN-based semiconductor having the band gap energy higher than that of the active layer114.

The second conductive semiconductor layer116includes the group III-V compound semiconductor doped with the second conductive dopant. For instance, the second conductive semiconductor layer116may include the semiconductor material having the compositional formula of InxAlyGa1−x−yN (0≦x≦1, 0≦y≦1, 0≦x+y≦1). In detail, the second conductive semiconductor layer116may include one selected from the group consisting of GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP, and AlGaInP. If the second conductive semiconductor layer116is a P type semiconductor layer, the second conductive dopant includes the P type dopant such as Mg, Zn, Ca, Sr, or Ba. The second conductive semiconductor layer116can be prepared as a single layer or a multiple layer, but the embodiment is not limited thereto.

The second conductive semiconductor layer116may include a p type GaN layer, which can be formed by injecting TMGa gas, NH3gas, N2gas and (EtCp2Mg) {Mg (C2H5C5H4)2} gas including p type impurities (for example, Mg) into the chamber, but the embodiment is not limited thereto.

According to the embodiment, the first conductive semiconductor layer112may include an N type semiconductor layer and the second conductive semiconductor layer116may include a P type semiconductor layer, but the embodiment is not limited thereto. In addition, a semiconductor layer, such as an N type semiconductor layer (not shown) having polarity opposite to that of the second conductive semiconductor layer116, can be formed on the second conductive semiconductor layer116. Thus, the light emitting structure110may include one of an N-P junction structure, a P-N junction structure, an N-P-N junction structure, and a P-N-P junction structure.

After that, the second electrode105is formed on the second conductive semiconductor layer116.

The second electrode105may include an ohmic layer (not shown), a reflective layer (not shown), a bonding layer (not shown) and a second substrate (not shown). The second electrode105may include at least one of Ti, Cr, Ni, Al, Pt, Au, W, Mo and a semiconductor substrate doped with impurities.

When the second electrode105includes the reflective layer, the reflective layer may include a metal or a metal alloy including at least one selected from the group consisting of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au and Hf. In addition, the reflective layer can be prepared as a multiple layer by using the above metal or metal alloy and transmissive conductive material, such as IZO, IZTO, IAZO, IGZO, IGTO, AZO, or ATO. For instance, the reflective layer may have the stack structure including IZO/Ni, AZO/Ag, IZO/Ag/Ni, or AZO/Ag/Ni.

In addition, if the second electrode layer120includes the bonding layer, the reflective layer may serve as the bonding layer or the bonding layer may include at least one selected from the group consisting of Ti, Au, Sn, Ni, Cr, Ga, In, Bi, Cu, Ag and Ta.

In addition, the second electrode105may include the second substrate. The second substrate may include a metal having superior electric conductivity, a metal alloy or conductive semiconductor material in order to facilitate the hole injection. For instance, the second substrate may include at least one selected from the group consisting of Cu, a Cu alloy, Au, Ni, Mo, Cu—W, and a carrier wafer, such as Si, Ge, GaAs, GaN, ZnO, SiGe, and SiC wafers.

The second substrate can be formed through the electrochemical metal deposition scheme or the bonding scheme using a eutectic metal.

Then, the first substrate is removed such that the first conductive semiconductor layer112can be exposed. The first substrate can be removed through the laser lift off scheme or the chemical lift off scheme. In addition, the first substrate can be removed by physically grinding the first substrate.

Thus, the light emitting structure110can be formed on the second electrode105shown inFIG. 1.

After the first substrate has been removed, the etching process can be performed with respect to the light emitting structure110such that the light emitting structure110may have an inclined inner sidewall, but the embodiment is not limited thereto.

Then, the first electrode120is formed on the light emitting structure110. The first electrode120may include the line pattern having the electric connection. The first electrode120can be electrically connected to the pad electrode (not shown).

After that, as shown inFIG. 3, the transmittive layer130is formed on the light emitting structure110.

For instance, a first pattern310is formed at a lateral side of the light emitting structure110and the transmittive layer130is formed by using the first pattern310as a barrier.

The transmittive layer130may have a thickness of about 2 μm to 200 μm but the embodiment is not limited thereto. For instance, the transmittive layer130may have a thickness of about 2 μm or above thicker than THE first electrode120formed on the light emitting structure110, but the embodiment is not limited thereto. In addition, the transmittive layer130may have a thickness of about 200 μm or below corresponding to the half of the total height of the light emitting device chip, but the embodiment is not limited thereto.

The transmittive layer130may include silicone gel, but the embodiment is not limited thereto.

According to the embodiment, the transmittive layer130having low thermal conductivity and high light transmittive property is interposed between the light emitting surface of the light emitting device chip and the luminescence material layer140, so that the heat generated from the light emitting surface of the light emitting structure110can be restricted from being transferred to the luminescence material layer140, thereby improving the wavelength conversion efficiency of the luminescence material.

Then, as shown inFIG. 4, the first pattern310may be removed and a second pattern320may be formed. After that, the luminescence material layer140may be formed on the transmittive layer130by using the second pattern320as a barrier.

The luminescence material layer140may have a thickness of about 5 μm to 500 μm, but the embodiment is not limited thereto. For instance, the luminescence material layer140may have a thickness of about 5 μm or above to convert blue light into yellow light or may have a thickness of about 500 μm or below by taking the size of the light emitting device chip into consideration, but the embodiment is not limited thereto.

The luminescence material layer140may include an encapsulating material including the luminescence material to protect the chip and to improve the light extraction efficiency.

The encapsulating material may include an epoxy encapsulating material or a silicon encapsulating material, but the embodiment is not limited thereto.

The luminescence material may include a host material and an active material. For instance, the luminescence material may include the host material of yttrium aluminum garnet (YAG) or a silicate-based material and the active material of cesium (Ce) or europium (Eu), but the embodiment is not limited thereto.

In order to encapsulate the encapsulating material, dispensing, casting molding, transfer molding, vacuum printing or screen printing can be performed.

After that, as shown inFIG. 5, the second pattern320is removed, thereby providing the light emitting device chip100according to the first embodiment.

According to the light emitting device chip of the embodiment, the luminescence material layer140is provided in the light emitting device chip, so that the light emitting device chip can spontaneously generate white light.

In addition, according to the embodiment, the heat generated from the light emitting device chip can be restricted from being transferred to the luminescence material layer, thereby improving the wavelength conversion efficiency of the luminescence material layer.

FIG. 6is a sectional view showing a light emitting device chip102according to the second embodiment.

The second embodiment may adopt the technical features of the first embodiment.

According to the second embodiment, the luminescence material layer includes a first luminescence material layer141formed on the transmittive layer130and a second luminescence material layer142formed on a part or a whole area of lateral sides of the light emitting structure110. Although the second luminescence material layer142formed on the whole area of lateral sides of the light emitting structure110is shown for illustrative purpose, the embodiment is not limited thereto.

According to the second embodiment, after the transmittive layer130is formed, a third pattern (not shown) spaced part from the transmittive layer130is formed as a barrier to form the luminescence material layer140, but the embodiment is not limited thereto.

According to the second embodiment, the proportion of light, such as blue light emitted from the light emitting surface of the light emitting device chip and extracted through the lateral side of the transmittive layer, can be adjusted, so that the optical characteristics, such as the color temperature variation depending on the viewing angles, can be controlled.

For instance, the first luminescence material layer141may have a first thickness T1and the second luminescence material layer142may have a second thickness T2.

According to the second embodiment, the second thickness T2is thicker than the first thickness T1by two times or less. AlthoughFIG. 6shows the second thickness T2thinner than the first thickness T1, this is illustrative purpose only. Actually, the second thickness T2is defined as 0<T2≦2T1.

According to the second embodiment, the proportion of light extracted through the lateral side of the transmittive layer can be adjusted by adjusting the second thickness T2of the second luminescence material layer142, so that the optical characteristics, such as the color temperature variation depending on the viewing angles, can be controlled.

In addition, according to the second embodiment, the proportion of light extracted through the lateral side of the transmittive layer can be adjusted according to the proportion of the second luminescence material layer142formed on the part or the whole area of the lateral sides of the light emitting structure110, so that the optical characteristics, such as the color temperature variation depending on the viewing angles, can be controlled.

FIG. 7ais a sectional view showing a light emitting device chip103according to the third embodiment.

The third embodiment may adopt the technical features of the first and second embodiments.

According to the third embodiment, a luminescence material layer143may include a patterned luminescence material layer.

According to the third embodiment, similar to the first embodiment, a predetermined patterning process is performed after the luminescence material layer has been formed, or the luminescence material layer is formed after a fourth pattern (not shown) has been formed and the fourth pattern is removed through the lift off scheme, but the embodiment is not limited thereto.

According to the third embodiment, the patterned luminescence material layer143is formed on the light emitting device chip, so that the light extraction area may be enlarged due to the patterned luminescence material layer143, thereby improving the light extraction efficiency.

According to the third embodiment, as shown inFIG. 7a, the transmittive layer130may be partially exposed through the patterned luminescence material layer143, but the embodiment is not limited thereto. In addition, the transmittive layer130and the light emitting structure110may be partially exposed through the patterned luminescence material layer143.

In addition, according to the third embodiment, the patterned luminescence material layer143can also be formed on the lateral sides of the light emitting structure110. Thus, the light emitted through the lateral sides of the light emitting structure110may be converted into the white light. In addition, the patterned luminescence material layer143may be formed on the part of the lateral sides of the light emitting structure110, other that the whole area of the lateral sides of the light emitting structure110, so that the color temperature of the light emitted from the light emitting device chip can be controlled by adjusting the thickness of the patterned luminescence material layer143formed on the lateral sides of the light emitting structure110.

According to the third embodiment, the area of the patterned luminescence material layer143is adjusted within 30% to 90% based on the light emitting area of the light emitting device chip, so that the color temperature of the light emitted from the light emitting device can be controlled.

FIG. 7bis a sectional view showing a light emitting device chip104according to the fourth embodiment.

The fourth embodiment may adopt the technical features of the first to third embodiments.

In the light emitting device chip104according to the fourth embodiment, a patterned luminescence material layer143bmay not expose the transmittive layer130.

According to the fourth embodiment, the patterned luminescence material layer143bis formed on the light emitting device chip, so that the light extraction area may be enlarged due to the patterned luminescence material layer143b, thereby improving the light extraction efficiency.

FIG. 8ais a sectional view showing a light emitting device chip200according to the second embodiment.

The fifth embodiment is an example of a lateral type light emitting device chip and may adopt the technical features of the first to fourth embodiments.

The light emitting device chip200according to the fifth embodiment includes a light emitting structure210formed on a non-conductive substrate205and provided with a first conductive semiconductor layer212, an active layer214and a second conductive semiconductor layer216, a transmittive layer230on the light emitting structure210, and a luminescence material layer240on the transmittive layer230. A third electrode222is formed on the first conductive semiconductor layer212and a fourth electrode226is formed on the second conductive semiconductor layer216.

FIG. 8bis a sectional view showing a light emitting device chip202according to the sixth embodiment.

The sixth embodiment may adopt the technical features of the first to fifth embodiments.

According to the sixth embodiment, the transmittive layer230maybe partially exposed through a patterned luminescence material layer240b, but the embodiment is not limited thereto. In addition, the transmittive layer230and the light emitting structure210may be partially exposed through the patterned luminescence material layer240b.

In addition, according to the sixth embodiment, a PSS (patterned sapphire substrate)207is formed on the non-conductive substrate205to improve the light extraction efficiency.

According to the light emitting device chip, the light emitting device package and the method of manufacturing the light emitting device chip of the embodiments, the luminescence material layer is formed in the light emitting device chip, so that the light emitting device chip can spontaneously generate the white light.

In addition, according to the embodiment, the heat generated from the light emitting device chip can be restricted from being transferred to the luminescence material layer, thereby improving the wavelength conversion efficiency of the luminescence material layer.

Further, according to the embodiment, the luminescence material layer having various shapes can be formed, so that the optical characteristics, such as the color temperature variation depending on the viewing angles, can be controlled.

In addition, according to the embodiment, the luminescence material layer is patterned on the light emitting device chip, so that the light extraction efficiency can be improved.

FIG. 9is a plan view showing the light emitting device chip according to the embodiment.

According to the present embodiment, the light emitting device chip further includes a pad electrode125electrically connected to the first electrode120and exposed upward of the transmittive layer130. For instance, in the case of the vertical type light emitting device, at least two pad electrodes125may be provided when the light emitting device has the mass storage, but the embodiment is not limited thereto.

FIG. 10is a view showing a light emitting device package500including the light emitting device chip according to the embodiments.

The light emitting device package500according to the embodiment includes a package body505, fifth and sixth electrode layers510and520formed on the package body505, the light emitting device chip100provided on the package body505and electrically connected to the fifth and sixth electrode layers510and520and a molding member540that surrounds the light emitting device chip100.

The package body505may include silicon, synthetic resin or a metallic material. An inclined surface may be formed around the light emitting device chip100.

The fifth and sixth electrode layers510and520are electrically isolated from each other to supply power to the light emitting device chip100. In addition, the fifth and sixth electrode layers510and520reflect the light emitted from the light emitting device chip100to improve the light efficiency and dissipate heat generated from the light emitting device chip100to the outside.

The light emitting device chips100,102,103and200according to first to fourth embodiments can be applied to the light emitting device package500and the light emitting device chip100can be installed on the package body505or the fifth or sixth electrode layer510or520.

The light emitting device chip100can be electrically connected to the fifth electrode layer510and/or the sixth electrode layer520through a wire530. Although only one wire530is shown inFIG. 10, the embodiment is not limited thereto. If the light emitting device chip according to the fourth embodiment is employed, a plurality of wires can be used.

The molding member540surrounds the light emitting device chip100to protect the light emitting device chip100.

According to the light emitting device chip and the light emitting device package of the embodiment, the luminescence material layer is provided in the light emitting device chip, so that the light emitting device chip can spontaneously generate white light.

In addition, according to the embodiment, the heat generated from the light emitting device chip can be restricted from being transferred to the luminescence material layer, thereby improving the wavelength conversion efficiency of the luminescence material layer.

Further, according to the embodiment, the luminescence material layer having various shapes can be formed, so that the optical characteristics, such as the color temperature variation depending on the viewing angles, can be controlled.

In addition, according to the embodiment, the luminescence material layer is patterned on the light emitting device chip, so that the light extraction efficiency can be improved.

A plurality of light emitting device packages according to the embodiment may be arrayed on a substrate, and an optical member including a light guide plate, a prism sheet, a diffusion sheet or a fluorescent sheet may be provided on the optical path of the light emitted from the light emitting device package. The light emitting device package, the substrate, and the optical member may serve as a backlight unit or a lighting unit. For instance, the lighting system may include a backlight unit, a lighting unit, an indicator, a lamp or a streetlamp.

FIG. 11is a perspective view showing a lighting unit1100according to the embodiment. The lighting unit1100shown inFIG. 11is an example of a lighting system and the embodiment is not limited thereto.

Referring toFIG. 11, the lighting unit1100includes a case body1110, alight emitting module1130installed in the case body1110, and a connection terminal1120installed in the case body1110to receive power from an external power source.

Preferably, the case body1110includes a material having superior heat dissipation property. For instance, the case body1110includes a metallic material or a resin material.

The light emitting module1130may include a substrate1132and at least one light emitting device package500installed on the substrate1132.

The substrate1132includes an insulating member printed with a circuit pattern. For instance, the substrate1132includes a PCB (printed circuit board), an MC (metal core) PCB, an F (flexible) PCB, or a ceramic PCB.

In addition, the substrate1132may include material that effectively reflects the light. The surface of the substrate1132can be coated with a color, such as a white color or a silver color, to effectively reflect the light.

At least one light emitting device package500can be installed on the substrate1132. Each light emitting device package500may include at least one LED (light emitting diode). The LED may include a colored LED that emits the light having the color of red, green, blue or white and a UV (ultraviolet) LED that emits UV light.

The light emitting device packages500of the light emitting module1130can be variously combined to provide various colors and brightness. For instance, the white LED, the red LED and the green LED can be combined to achieve the high color rendering index (CRI).

The connection terminal1120is electrically connected to the light emitting module1130to supply power to the light emitting module1130. Referring toFIG. 11, the connection terminal1120has a shape of a socket screw-coupled with the external power source, but the embodiment is not limited thereto. For instance, the connection terminal1120can be prepared in the form of a pin inserted into the external power source or connected to the external power source through a wire.

FIG. 12is an exploded perspective view showing a backlight unit1200according to the embodiment. The backlight unit1200shown inFIG. 12is an example of a lighting system and the embodiment is not limited thereto.

The backlight unit1200according to the embodiment includes a light guide plate1210, a light emitting module1240for providing the light to the light guide plate1210, a reflective member1220positioned below the light guide plate, and a bottom cover1230for receiving the light guide plate1210, light emitting module1240, and the reflective member1220therein, but the embodiment is not limited thereto.

The light guide plate1210diffuses the light to provide surface light. The light guide1210includes transparent material. For instance, the light guide plate1210can be manufactured by using acryl-based resin, such as PMMA (polymethyl methacrylate), PET (polyethylene terephthalate), PC (polycarbonate), COC or PEN (polyethylene naphthalate) resin.

The light emitting module1240supplies the light to the lateral side of the light guide plate1210and serves as the light source of the display device including the backlight unit.

The light emitting module1240can be positioned adjacent to the light guide plate1210, but the embodiment is not limited thereto. In detail, the light emitting module1240includes a substrate1242and a plurality of light emitting device packages500installed on the substrate1242and the substrate1242can be adjacent to the light guide plate1210, but the embodiment is not limited thereto.

The substrate1242may include a printed circuit board (PCB) having a circuit pattern (not shown). In addition, the substrate1242may also include a metal core PCB (MCPCB) or a flexible PCB (FPCB), but the embodiment is not limited thereto.

In addition, the light emitting device packages500are arranged such that light exit surfaces of the light emitting device packages500are spaced apart from the light guide plate1210by a predetermined distance.

The reflective member1220is disposed below the light guide plate1210. The reflective member1220reflects the light, which is travelled downward through the bottom surface of the light guide plate1210, toward the light guide plate1210, thereby improving the brightness of the backlight unit. For instance, the reflective member1220may include PET, PC or PVC resin, but the embodiment is not limited thereto.

The bottom cover1230may receive the light guide plate1210, the light emitting module1240, and the reflective member1220therein. To this end, the bottom cover1230has a box shape with an open top surface, but the embodiment is not limited thereto.

The bottom cover1230can be manufactured through a press process or an extrusion process by using metallic material or resin material.

According to the light emitting device chip, the light emitting device package and the lighting system of the embodiment, the luminescence material layer is provided in the light emitting device chip, so that the light emitting device chip can spontaneously generate white light.

In addition, according to the embodiment, the heat generated from the light emitting device chip can be restricted from being transferred to the luminescence material layer, thereby improving the wavelength conversion efficiency of the luminescence material layer.

Further, according to the embodiment, the luminescence material layer having various shapes can be formed, so that the optical characteristics, such as the color temperature variation depending on the viewing angles, can be controlled.

In addition, according to the embodiment, the luminescence material layer is patterned on the light emitting device chip, so that the light extraction efficiency can be improved.