KR102127440B1 - Light Emitting Device Package - Google Patents

Abstract

The light emitting device package of the embodiment includes a base layer having first and second regions, a light emitting element disposed on the base layer of the first region, and a reflective layer disposed on the base layer of the second region, and the base on which the reflective layer is disposed The upper portion of the second region of the layer is inclined downward so that light emitted from the light emitting element is reflected by the reflective layer.

Description

Light Emitting Device Package

The embodiment relates to a light emitting device package.

Based on the development of gallium nitride (GaN) metal organic chemical vapor deposition and molecular beam growth, light emitting devices of red, green and blue light emitting diodes (LEDs) capable of realizing high luminance and white light have been developed.

Since these LEDs do not contain environmentally harmful substances such as mercury (Hg) used in existing lighting fixtures such as incandescent and fluorescent lamps, they have excellent eco-friendliness, and have advantages such as long life and low power consumption characteristics. Is replacing it. A key competing element of the LED device is the implementation of high efficiency and high brightness by high power chip and packaging technology. In order to realize high luminance, it is important to increase light extraction efficiency.

Flip-chip structure, surface texturing, patterned sapphire substrate (PSS), photonic crystal technology and anti-reflection to increase light extraction efficiency layer) Various methods using structures and the like have been studied.

On the other hand, in the case of a light emitting device package having a flip chip structure, light emitted from the light emitting device can be reflected by a reflective layer disposed on the submount to improve the amount of light. However, a part of the light reflected by the reflective layer is not emitted from the light emitting device package, but is absorbed by the light emitting device and extinguished, so that there is a problem in that the light amount is lowered.

The embodiment provides a light emitting device package capable of improving light extraction efficiency by preventing the emitted light from being absorbed again by the light emitting device.

The light emitting device package of the embodiment includes a base layer having first and second regions; A light emitting element disposed on the base layer in the first region; And a reflective layer disposed on the base layer of the second region, and an upper portion of the second region of the base layer is inclined downward so that light emitted from the light emitting element is reflected by the reflective layer.

The light emitting device package includes a sub-mount disposed between the base layer and the light emitting device in the first region; And a bump portion disposed between the sub-mount and the light emitting element.

The inclined angle of the upper portion of the second region is as follows.

Here, θ denotes the angle, L _b denotes a separation distance between a lower surface from which light is emitted from the light emitting element and an upper surface of the submount, L _S denotes the length of the submount, and L _C The length of the light emitting element is indicated, and the light emitting element is disposed in the upper center of the submount.

The inclined curvature of the upper portion of the second region is as follows.

Here, 1/r' denotes the curvature, and θ is a horizontal line extending from the lower surface of the light emitting element and the optical path through which light emitted from the edge of the lower surface of the light emitting element proceeds without loss due to the submount. An angle, L _b represents a separation distance between a lower surface from which light is emitted from the light emitting element and an upper surface of the sub mount, and t _S represents the thickness of the sub mount.

The distance from the side of the sub-mount to the second region at the top of the first region is as follows.

Here, d'denotes the distance, t _S denotes the thickness of the submount, and θ denotes an optical path and light emitting element in which light emitted from an edge of the lower surface of the light emitting element proceeds without loss due to the submount. It represents an angle formed by a horizontal line extending from the lower surface of.

In the light emitting device package according to the embodiment, the reflective layer is formed to be inclined, so that the amount of light can be improved by allowing light reflected from the reflective layer to be emitted from the light emitting device package without being absorbed by the light emitting device.

1A and 1B are cross-sectional views of a light emitting device package according to an embodiment.
2A and 2B are cross-sectional views of a light emitting device package according to another embodiment.
3 is a cross-sectional view of a light emitting device package according to an embodiment.
4 is a perspective view of a lighting unit according to an embodiment.
5 is an exploded perspective view of a backlight unit according to an embodiment.

Hereinafter, examples will be described to specifically describe the present invention, and the present invention will be described in detail with reference to the accompanying drawings to help understand the invention. However, the embodiments according to the present invention may be modified in various other forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. The embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art.

In the description of this embodiment, in the case of being described as being formed on "on (under) or under (under)" (on or under) of each element, the upper (upper) or lower (lower) ( on or under includes both two elements directly contacting each other or one or more other elements being formed indirectly between the two elements.

In addition, when expressed as "up (up)" or "down (down) (on or under)", it may include the meaning of the downward direction as well as the upward direction based on one element.

In addition, relational terms, such as “first” and “second,” “upper” and “lower”, as used below, do not necessarily imply or imply any physical or logical relationship or order between such entities or elements. Thus, it may be used only to distinguish one entity or element from another entity or element.

1A and 1B are cross-sectional views of a light emitting device package 100A according to an embodiment. Here, FIG. 1A is a view for explaining the principle of reflecting light in the light emitting device package 100A illustrated in FIG. 1B.

The light emitting device package 100A illustrated in FIG. 1B includes a base layer 110A, a reflective layer 120A, a submount 130, first and second metal layers 142, 144, and first and second bumps. It includes parts 152, 154, first and second electrodes 162, 164, a light emitting structure 170, a buffer layer 180, and a substrate 190.

The base layer 110A has a first region A1 and second regions A2-1 and A2-2. The base layer 110A may correspond to the body of the light emitting device package 100A. In addition, the base layer 110A may be a substrate, for example, various types of substrates such as a metal-core printed circuit board (MCPCB) or an aluminum (Al) mirror substrate.

The top of the first region A1 of the base layer 110A is flat, while the top of the second regions A2-1 and A2-2 is inclined downward from the top of the first region A1. The reason and the degree of inclination of the second regions A2-1 and A2-2 will be described later in detail. 1B, the second regions A2-1 and A2-2 are illustrated as two, but the embodiment is not limited thereto. That is, only one second region A2-1 or A2-2 may be provided.

The light emitting device is disposed on the base layer 110A in the first region A1, and the reflective layer 120A is disposed on the base layer 110A in the second regions A2-1 and A2-2. 1B, the reflective layer 120A is illustrated as being disposed not only in the second regions A2-1 and A2-2 of the base layer 110A but also in the first region A1, but the embodiment is not limited thereto. That is, the reflective layer 120A is only disposed on the base layer 110A of the second regions A2-1 and A2-2, and may not be disposed on the base layer 110A of the first region A1. As described above, since the upper portion of the base layer 110A of the second regions A2-1 and A2-2 is inclined, the reflective layer disposed on the base layer 110A of the second regions A2-1 and A2-2 is inclined. Likewise, 120A is inclined along the shape of the base layer 110A.

The reflective layer 120A includes silver (Ag), nickel (Ni), aluminum (Al), rhodium (Rh), palladium (Pd), iridium (Ir), ruthenium (Ru), magnesium (Mg), zinc (Zn), Platinum (Pt), gold (Au), hafnium (Hf), and may be formed of a single layer or a plurality of layers among materials composed of two or more of them.

Meanwhile, a sub-mount 130 may be disposed between the base layer 110A of the first region A1 and the light emitting element. 1A and 1B, when the reflective layer 120A is disposed on the base layer 110A of the first area A1, the sub-mount 130 is disposed between the reflective layer 120A and the light emitting element.

For example, the sub-mount 130 may be formed of a semiconductor substrate such as AlN, BN, silicon carbide (SiC), GaN, GaAs, Si, and may be made of a semiconductor material having thermal properties. Alternatively, the sub-mount 130 may be implemented with Al ₂ O ₃ , Ga ₂ O ₃ , or the like, and may have a thickness of 350 μm to 400 μm, for example.

If the sub-mount 130 is made of Si, an insulating layer 132 may be further disposed between the first and second metal layers 142 and 144 and the sub-mount 130. Here, the insulating layer may be made of an insulating material such as SiO ₂ .

The first and second metal layers 142 and 144 are spaced apart from each other in the horizontal direction on the submount 130. Each of the first and second metal layers 142 and 144 may include a metallic material. For example, each of the first and second metal layers 142 and 144 may be at least one of Ag, Ni, Al, Rh, Pd, Ir, Ti, Ru, Mg, Zn, Pt, Au, or Hf, or a selective thereof. It may be formed of a metal or alloy containing a combination. Alternatively, each of the first and second metal layers 142 and 144 may be formed in multiple layers by using a metal or alloy and a light-transmitting conductive material such as ITO, IZO, IZTO, IAZO, IGZO, IGTO, AZO, and ATO, specifically As, IZO/Ni, AZO/Ag, IZO/Ag/Ni, AZO/Ag/Ni, Ag/Cu, Ag/Pd/Cu, and the like may be stacked.

Meanwhile, first and second bump portions 152 and 154 are disposed between the sub-mount 130 and the light emitting element. The first bump part 152 electrically connects the first metal layer 142 and the first conductive semiconductor layer 172 of the light emitting device, and the second bump part 154 has a second metal layer 144 and the light emitting device. The second conductive type semiconductor layer 176 is electrically connected.

Although not shown, a first upper bump portion metal layer (not shown) is further disposed between the first electrode 162 and the first bump portion 152 of the light emitting device, and the first metal layer 142 and the first bump A first lower bump portion metal layer (not shown) may be further disposed between the portions 152. Here, the first upper bump portion metal layer and the first lower bump portion metal layer serve to indicate a position where the first bump portion 152 will be located. Similarly, a second upper bump portion metal layer (not shown) is further disposed between the second electrode 164 and the second bump portion 154 of the light emitting device, and the second metal layer 144 and the second bump portion 154 are further disposed. A second lower bump portion metal layer (not shown) may be further disposed therebetween. Here, the second upper bump portion metal layer and the second lower bump portion metal layer serve to indicate a position where the second bump portion 154 will be located.

On the other hand, the light emitting elements disposed on the first and second bump portions 154 include LEDs using a plurality of compound semiconductor layers, and the LEDs are colored LEDs that emit light such as blue, green, or red, ultraviolet (UV) :UltraViolet) LED, deep ultraviolet LED, or non-polarized LED. The emitted light of the LED may be implemented using various semiconductors, but is not limited thereto.

The light emitting device illustrated in FIG. 1B includes first and second electrodes 162 and 164, a light emitting structure 170, a buffer layer 180, and a substrate 190.

The substrate 190 is disposed on the light emitting structure 170. The substrate 190 may be translucent so that light emitted from the active layer 174 is emitted through the substrate 190. For example, the substrate 190 may be formed of at least one of sapphire (Al ₂ O ₃ ), SiC, GaAs, GaN, ZnO, Si, GaP, InP, and Ge, but is not limited thereto. In addition, the substrate 190 may have a mechanical strength sufficient to separate well into separate chips through a scribing process and a breaking process without bringing warpage to the entire nitride semiconductor.

The buffer layer 180 is disposed between the substrate 190 and the light emitting structure 170 to improve the lattice matching between the substrate 190 and the light emitting structure 170. For example, the buffer layer 180 may include AlN or undoped nitride, but is not limited thereto. The buffer layer 180 may be omitted depending on the type of the substrate 190 and the type of the light emitting structure 170.

The light emitting structure 170 is disposed under the buffer layer 180. The light emitting structure 170 may have a form in which the first conductivity type semiconductor layer 172, the active layer 174, and the second conductivity type semiconductor layer 176 are sequentially stacked.

The first conductivity-type semiconductor layer 172 is disposed between the substrate 190 and the active layer 174 and may be formed of a semiconductor compound. It may be implemented with a compound semiconductor such as Ⅲ-Ⅴ group, Ⅱ-Ⅵ group, and the first conductivity type dopant may be doped. For example, the first conductivity type semiconductor layer 172 has a composition formula of Al _x In _y Ga _(1-xy) N (0≤x≤1, 0≤y≤1, 0≤x+y≤1) It may be formed of any one or more of a semiconductor material, InAlGaN, AlGaAs, GaP, GaAs, GaAsP, AlGaInP. When the first conductivity-type semiconductor layer 172 is an n-type semiconductor layer, the first conductivity-type dopant may include an n-type dopant such as Si, Ge, Sn, Se, or Te. The first conductivity-type semiconductor layer 172 may be formed as a single layer or multiple layers, but is not limited thereto. If the light emitting device illustrated in FIG. 1B is an ultraviolet (UV), deep ultraviolet (UV), or non-polarized light emitting device, the first conductive semiconductor layer 172 may include at least one of InAlGaN and AlGaN. . When the first conductivity type semiconductor layer 172 is made of AlGaN, the Al content may be 50%, but the embodiment is not limited thereto.

The active layer 174 is disposed between the first conductivity type semiconductor layer 172 and the second conductivity type semiconductor layer 176, a single well structure, a multi well structure, a single quantum well structure, a multi quantum well (MQW) Well) structure, a quantum dot structure or a quantum wire structure. The active layer 174 is a well layer and a barrier layer using a compound semiconductor material of a group III-V element, for example, InGaN/GaN, InGaN/InGaN, GaN/AlGaN, InAlGaN/GaN, GaAs (InGaAs),/AlGaAs, It may be formed of any one or more pair structure of GaP (InGaP) / AlGaP, but is not limited thereto. The well layer may be formed of a material having an energy band gap smaller than the energy band gap of the barrier layer. In particular, the active layer 174 according to the embodiment may generate light of ultraviolet or deep ultraviolet wavelengths.

The second conductivity-type semiconductor layer 176 may be disposed under the active layer 174. The second conductivity-type semiconductor layer 176 may be formed of a semiconductor compound. The second conductivity-type semiconductor layer 176 may be formed of a compound semiconductor such as a III-V group or a II-VI group, and the second conductivity-type dopant may be doped. For example, a semiconductor material having a composition formula of In _x Al _y Ga _1-xy N (0≤x≤1, 0≤y≤1, 0≤x+y≤1) or AlInN, AlGaAs, GaP, GaAs, GaAsP, AlGaInP It may be formed of any one or more of. When the second conductivity-type semiconductor layer 176 is a p-type semiconductor layer, the second conductivity-type dopant may be a p-type dopant such as Mg, Zn, Ca, Sr or Ba. The second conductivity-type semiconductor layer 176 may be formed as a single layer or multiple layers, but is not limited thereto. If the light emitting device illustrated in FIG. 1B is an ultraviolet (UV), deep ultraviolet (UV), or non-polarized light emitting device, the second conductive semiconductor layer 176 may include at least one of InAlGaN and AlGaN. The embodiment is not limited to this.

Also, an electron blocking layer (EBL) (not shown) may be selectively disposed between the active layer 174 and the second conductivity type semiconductor layer 176. The electron blocking layer may be made of a semiconductor material having a larger energy band gap than the second conductivity type semiconductor layer 176. When the electron blocking layer EBL has a larger energy band gap than the second conductivity type semiconductor layer 176, electrons provided from the first conductivity type semiconductor layer 172 are not recombined in the active layer 174 of the MQW structure It is possible to effectively prevent overflow of the second conductive semiconductor layer 176. The electron blocking layer may include aluminum (Al) having a higher content than the barrier layer of the active layer 174.

Referring to FIG. 1B, the first electrode 162 is disposed between the first conductivity type semiconductor layer 172 and the first bump portion 152, and the first metal layer 142 is disposed through the first bump portion 152. And is connected. The second electrode 164 is disposed between the second conductivity type semiconductor layer 176 and the second bump portion 154 and is connected to the second metal layer 144 through the second bump portion 154. The first and second electrodes 162 and 164 respectively contacting the first and second conductivity-type semiconductor layers 172 and 176 may be formed of a metal, for example, Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, Hf, and optional combinations thereof.

Each of the first and second electrodes 162 and 164 may be a transparent conductive oxide (TCO). For example, each of the first and second electrodes 162 and 164 includes the aforementioned metal material, indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), and indium aluminum zinc oxide (AZAO). ), indium gallium zinc oxide (IGZO), indium gallium tin oxide (IGTO), aluminum zinc oxide (AZO), antimony tin oxide (ATO), gallium zinc oxide (GZO), IrOx, RuOx, RuOx/ITO, Ni/IrOx /Au, and Ni/IrOx/Au/ITO, but are not limited to these materials. The first and second electrodes 162 and 164 may include materials in ohmic contact with the first and second conductivity type semiconductor layers 172 and 176, respectively.

Further, each of the first and second electrodes 162 and 164 may be formed of a single layer or multiple layers of a reflective electrode material having ohmic characteristics. If the first and second electrodes 162 and 164 perform an ohmic role, separate ohmic layers (not shown) may not be formed.

The upper portions of the second regions A2-1 and A2-2 in the above-described base layer 110A are formed to be inclined downward, so that light emitted from the light emitting element is reflected by the reflective layer 120A.

Hereinafter, the inclined angle of the upper portion of the base layer 110A in which the reflective layers 120A are disposed in the second regions A2-1 and A2-2 will be described as follows with reference to FIG. 1A.

The distance d that the light 10 emitted from the edge of the lower surface of the light emitting element does not interfere with the submount 130 and touches the base layer 110A is as shown in Equation 1 below.

Here, t _S denotes the thickness of the submount 130, and θ1 is the light path 10 and the light emitting element through which light emitted from the edge of the lower surface 176A of the light emitting element proceeds without loss by the submount 130 It represents the angle formed by the horizontal line 20 extending from the lower surface 176A. Here, when the emitted light is not absorbed by the sub-mount 130, there is no light loss by the sub-mount 130.

If it is assumed that the light emitting element is disposed in the center of the sub-mount 130, tanθ1 in Equation 1 is expressed as Equation 2 below.

Here, L _b represents the separation distance between the lower surface 176A from which the light is emitted from the light emitting element and the upper surface of the sub mount 130, L _S represents the length of the sub mount 130, and L _C emits light Indicates the length of the device. If the insulating layer 132 is disposed, L _b represents the separation distance between the lower surface 176A from which light is emitted from the light emitting element and the upper surface of the insulating layer 132.

Equation 2 may be expressed as Equation 3 below.

In order for the light emitted from the light emitting element to be reflected by the reflective layer 120A, the inclined angle θ2 above the second regions A2-1 and A2-2 of the base layer 110A is an angle (θ1) of Equation 3 ). That is, the angle θ2 is as shown in Equation 4 below.

As described above, when the inclined angle θ2 above the second regions A2-1 and A2-2 is equal to Equation 4, the light 10 emitted from the light emitting element is arrow direction 12 in the reflective layer 120A. ).

In the light emitting device package 100A illustrated in FIG. 1B, the inclined angle θ3 above the second regions A2-1 and A2-2 satisfies Equation (4). Therefore, since light is reflected from the reflective layer 120A in the direction of the arrow 12 and is not re-incident to the light-emitting element, light is not lost due to re-incidence into the light-emitting element, so that the luminous efficiency can be improved.

In the case of FIG. 1B, the upper portions of the second regions A2-1 and A2-2 are inclined at a constant angle θ3, but may have a constant curvature (1/r') according to another embodiment.

Hereinafter, the curvature in which the upper portions of the second regions A2-1 and A2-2 are inclined will be described as follows.

2A and 2B are cross-sectional views of a light emitting device package 100B according to another embodiment. Here, FIG. 2A is a view for explaining the principle of reflecting light in the light emitting device package 100B shown in FIG. 2B.

The light emitting device package 100B illustrated in FIG. 2B includes a base layer 110B, a reflective layer 120B, a submount 130, first and second metal layers 142 and 144, and first and second bump portions 152 , 154, first and second electrodes 162 and 164, a light emitting structure 170, a buffer layer 180 and a substrate 190.

In the light emitting device package 100A shown in FIG. 1B and the light emitting device package 100B shown in FIG. 2B, the sub-mount 130, the insulating layer 132, the first and second metal layers 142, 144, and Since the first and second bump parts 152 and 154, the first and second electrodes 162 and 164, the light emitting structure 170, the buffer layer 180 and the substrate 190 are the same, respectively, the same reference numerals are used, Detailed description of these is omitted. That is, the light emitting device illustrated in FIG. 2B also includes first and second electrodes 162 and 164, a light emitting structure 170, a buffer layer 180, and a substrate 190.

Referring to FIG. 2A, the light 10 emitted from the edge of the lower surface 176A of the light emitting device extends from the optical path 10 and the lower surface 176A of the light emitting device without loss due to the submount 130. The angle θ1 formed by the horizontal line 20 may be expressed by Equation 5 below.

Here, L _p represents the length of the optical path 10 formed by the light emitted from the lower surface 176A of the light emitting element.

In addition, the angle θ1 illustrated in FIG. 2A may be expressed as Equation 6 below.

The above equations 5 and 6 can be summarized as follows.

When Equation 7 is expressed as a curvature (1/r), Equation 8 is given.

In order for the light emitted from the light emitting element to be reflected by the reflective layer 120B, the inclined curvature (1/r') of the second regions A2-1 and A2-2 of the base layer 110B is expressed by Equation (8). It should be less than the curvature (1/r'). That is, the curvature (1/r') is expressed by Equation 9 below.

In the light emitting device package 100B illustrated in FIG. 2B, the inclined curvature (1/r') above the second regions A2-1 and A2-2 satisfies Equation (9). Therefore, the light 10 emitted from the light emitting element can be reflected in the direction of the arrow 22 in the reflective layer 120B.

Meanwhile, referring to FIGS. 1A and 2A, in order to allow the light 10 emitted from the light emitting element to be reflected by the reflective layers 120A and 120B and proceed in the arrow directions 12 and 22, the first region A1 The distance d'from the side of the sub-mount 130 at the upper portion of the second region A2-1 and A2-2 should be smaller than the distance d of Equation 1 as shown in Equation 10 below.

If the condition of Equation 10 is not satisfied, light cannot be reflected from the reflective layers 120A and 120B.

To help understand the light emitting device package according to the above-described embodiment, the light emitting device package illustrated in FIGS. 1B and 2B has been described as having a flip chip bonding structure, but the embodiment is not limited thereto. That is, the aforementioned light emitting device package can be applied to vertical and horizontal structures.

3 is a cross-sectional view of a light emitting device package 200 according to an embodiment.

The light emitting device package 200 according to the embodiment includes a light emitting device, a header 210, an adhesive portion 220, a pair of lead wires 232 and 234, wires 242 and 244, and a sidewall portion 250 And a molding member 260. In the light emitting device package of FIG. 3, the base layer 110A, the reflective layer 120A, the submount 130, the first and second metal layers 142, 144, the first and second buffer units 152, 154, and Since the first and second electrodes 162 and 164, the light emitting structure 170, the buffer layer 180, and the substrate 190 are the same as the light emitting device package 100A illustrated in FIG. 1B, the same reference numerals are used. The detailed description is omitted.

Of course, in addition to the light emitting device package 100A illustrated in FIG. 1B, the light emitting device package 100B illustrated in FIG. 2B can be applied to the structure illustrated in FIG. 3.

The base layer 110A is connected to the header 210 by an adhesive portion 220. The adhesive portion 220 may be in the form of solder or paste. The first and second metal layers 142 and 144 are connected to the pair of lead wires 232 and 234 by wires 242 and 244, respectively. Power is provided to the light emitting device through a pair of lead wires 232 and 234 that are electrically separated from each other.

The molding member 260 may be filled in the cavity of the package 200 formed by the side wall portion 250 to surround and protect the light emitting device. Further, the molding member 260 may include a phosphor to change the wavelength of light emitted from the light emitting device.

In the light emitting device package according to another embodiment, a plurality of light emitting device packages are arranged on a substrate, and a light guide plate, a prism sheet, a diffusion sheet, a fluorescent sheet, and the like, may be disposed on a path of light emitted from the light emitting device package. The light emitting device package, the substrate, and the optical member may function as a backlight unit or may function as a lighting unit, for example, the lighting system may include a backlight unit, a lighting unit, an indicator device, a lamp, and a street light.

4 is a perspective view of a lighting unit 300 according to an embodiment. However, the lighting unit 300 of FIG. 4 is an example of a lighting system, and is not limited thereto.

In an embodiment, the lighting unit 300 includes a case body 310, a connection terminal 320 installed on the case body 310 and receiving power from an external power source, and a light emitting module unit 330 installed on the case body 310. ).

The case body 310 is formed of a material having good heat dissipation properties, and may be formed of metal or resin.

The light emitting module unit 330 may include a substrate 332 and at least one light emitting device package 200 mounted on the substrate 332. The circuit board 332 may be a circuit pattern printed on an insulator, for example, a general printed circuit board (PCB), a metal core PCB, a metal core PCB, a flexible PCB, a ceramic PCB, etc. It can contain.

In addition, the substrate 332 may be formed of a material that efficiently reflects light, or the surface may be formed of a color in which light is efficiently reflected, for example, white, silver, or the like.

At least one light emitting device package 200 may be mounted on the substrate 332. Each of the light emitting device packages 200 may include at least one light emitting device, for example, a light emitting diode (LED). The light emitting diode may include a colored light emitting diode that emits red, green, blue, or white colored light, respectively, and a UV light emitting diode that emits ultraviolet light (UV, UltraViolet). Here, the light emitting device package is the light emitting device package 200 illustrated in FIG. 3, but is not limited thereto.

The light emitting module unit 330 may be arranged to have a combination of various light emitting device packages 200 to obtain color and luminance. For example, a white light emitting diode, a red light emitting diode, and a green light emitting diode may be arranged in combination to ensure high color rendering (CRI).

The connection terminal 320 may be electrically connected to the light emitting module unit 330 to supply power. In an embodiment, the connection terminal 320 is fitted to the external power supply in a socket manner, but is not limited thereto. For example, the connection terminal 320 may be formed in a pin shape to be inserted into an external power source, or may be connected to an external power source by wiring.

5 is an exploded perspective view of the backlight unit 400 according to the embodiment. However, the backlight unit 400 of FIG. 5 is an example of a lighting system, and is not limited thereto.

The backlight unit 400 according to the embodiment includes a light guide plate 410, a reflective member 420 under the light guide plate 410, a bottom cover 430, and a light emitting module unit 440 providing light to the light guide plate 410 ). The bottom cover 430 accommodates the light guide plate 410, the reflective member 420, and the light emitting module unit 440.

The light guide plate 410 diffuses light to serve as a surface light source. The light guide plate 410 is made of a transparent material, for example, acrylic resin series such as PMMA (polymethyl methacrylate), PET (polyethylene terephthlate), PC (poly carbonate), COC (cycloolefin copolymer) and PEN (polyethylene naphthalate) resin It may include one of.

The light emitting module unit 440 provides light to at least one side of the light guide plate 410, and ultimately acts as a light source of a display device in which a backlight unit is installed.

The light emitting module unit 440 may contact the light guide plate 410, but is not limited thereto. Specifically, the light emitting module unit 440 includes a substrate 442 and a plurality of light emitting device packages 200 mounted on the substrate 442. Here, the light emitting device package 200 may be the light emitting device package illustrated in FIG. 3. The substrate 442 may contact the light guide plate 410, but is not limited thereto.

The substrate 442 may be a PCB including a circuit pattern (not shown). However, the substrate 442 may include not only a general PCB, but also a metal core PCB (MCPCB, metal core PCB), a flexible PCB, and the like.

In addition, the plurality of light emitting device packages 200 may be mounted on the substrate 442 so that a light emitting surface from which light is emitted is spaced apart from the light guide plate 410 by a predetermined distance.

A reflective member 420 may be formed under the light guide plate 410. The reflective member 420 reflects the light incident on the lower surface of the light guide plate 410 and faces upward, thereby improving luminance of the backlight unit. The reflective member 420 may be formed of, for example, PET, PC, or PVC resin, but is not limited thereto.

The bottom cover 430 may receive the light guide plate 410, the light emitting module unit 440, and the reflective member 420. To this end, the bottom cover 430 may be formed in a box shape with an open top surface, but is not limited thereto.

The bottom cover 430 may be formed of metal or resin, and may be manufactured using processes such as press molding or extrusion molding.

The embodiments have been mainly described above, but this is merely an example and does not limit the present invention, and those of ordinary skill in the art to which the present invention pertains have not been exemplified above in a range not departing from the essential characteristics of the present embodiment. It will be appreciated that various modifications and applications are possible. For example, each component specifically shown in the embodiments can be implemented by modification. And differences related to these modifications and applications should be construed as being included in the scope of the invention defined in the appended claims.

100A, 100B, 200: light emitting device package 110A, 110B: base layer
120A, 120B: reflective layer 130: sub-mount
142, 144: metal layer 152, 154: bump portion
162, 164: electrode 170: light emitting structure
180: buffer layer 190: substrate
210: header 220: adhesive
232, 234: lead wires 242, 244: wire
250: side wall portion 260: molding member
300: lighting unit 310: case body
320: connection terminal 330, 440: light emitting module unit
400: backlight unit 410: light guide plate
420: reflective member 430: bottom cover

Claims (6)

A base layer including an upper surface and a lower surface;
A reflective layer disposed on the base layer;
A sub-mount disposed on the reflective layer; And
It includes a light emitting device disposed on the sub-mount, The upper surface of the base layer includes a flat surface, and an inclined surface located around the flat surface,
The inclined surface is inclined toward the bottom surface of the base layer,
The reflective layer may include a first reflective layer disposed on the flat surface of the base layer; And a second reflective layer disposed on the inclined surface,
The second reflective layer is inclined along the inclined surface of the base layer,
The first inclination angle formed by the first edge of the bottom surface of the light emitting element and the second edge of the first reflective layer adjacent to the first edge is formed by the first edge and the third edge of the submount adjacent to the first edge. Less than the second inclination angle,
The third edge is a light emitting device package located inside the second edge. According to claim 1,
A light emitting device package further comprising a bump portion disposed between the sub-mount and the light emitting device. The method of claim 1, wherein the inclined surface is inclined in a straight line,
The inclined third inclination angle of the inclined surface is the following light emitting device package.

(Where, θ represents the third inclination angle, L _b represents the separation distance between the bottom surface and the top surface of the sub-mount from which the light is emitted from the light emitting element, L _S represents the length of the sub-mount, L _C represents the length of the light-emitting element, and the light-emitting element is disposed in the upper center of the sub-mount.) The method of claim 1, wherein the inclined surface has a curvature
The curvature of the inclined surface is the following light emitting device package.

(Where 1/r' represents the curvature, and θ is an optical path through which light emitted from the first edge of the bottom surface of the light emitting device proceeds without loss due to the submount and extends from the bottom surface of the light emitting device Represents the angle formed by the horizontal line, L _b represents the separation distance between the bottom surface from which light is emitted from the light emitting element and the top surface of the sub mount, and t _S represents the thickness of the sub mount.) According to claim 1, The distance from the side of the sub-mount to the inclined surface at the top of the flat surface is a light emitting device package as follows.

(Where d'denotes the distance, tS denotes the thickness of the submount, and θ denotes an optical path through which light emitted from the first edge of the bottom surface of the light emitting device proceeds without loss due to the submount. It represents an angle formed by a horizontal line extending from the bottom surface of the light emitting device.) The method of claim 1, wherein the base layer includes a first portion having the flat surface, and a second portion having the inclined surface,
The thickness of the second portion is gradually reduced toward the outer surface of the second portion from the first portion of the light emitting device package.

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