KR20120109732A - Light emitting device package and lighting system - Google Patents

Abstract

PURPOSE: A light emitting device package and a lighting system are provided to improve optical extraction efficiency by preventing reflecting characteristics of an electrode to be demoralized by a diffusion phenomenon of metal. CONSTITUTION: A light emitting device is placed on a body. A first electrode and a second electrode are connected to the light emitting device. The first electrode and the second electrode comprise a first metal layer(210) consisting of first metal, a second metal layer(220), and a barrier layer(230). The second metal layer is comprised of second metal in which reflectance is higher than the first metal. The barrier layer blocks metal diffusion between the second metal layer and the first metal layer.

Description

Light emitting device package and lighting system

A light emitting device package and an illumination system.

The light emitting diode (LED) of the light emitting device converts an electric signal into an infrared ray, visible light or light form using the characteristics of a compound semiconductor. It is a household electrical appliance, a remote control, an electronic board, an indicator, and various automation devices. It is used in a lamp and the like, and the use area of LED is gradually increasing.

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

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

The embodiment is intended to prevent the plating layer formed on the electrode included in the light emitting device package from dropping reflectivity due to inflow or oxidation of another metal.

The problems of the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, a light emitting device package according to an embodiment includes a light emitting device for outputting light and an electrode for supplying power to the light emitting device, the electrode is a first metal layer made of a first metal, and A second metal layer made of a second metal having a higher reflectivity than the first metal and reflecting the light emitted from the light emitting device and blocks diffusion of the metal between the first metal layer and the second metal layer, and has a lower diffusion rate than that of the first metal. It includes a barrier layer having a. Specific details of other embodiments are included in the detailed description and the drawings.

According to the embodiment, it is possible to prevent the phenomenon in which the reflective characteristic of the electrode is lowered by the diffusion phenomenon of the metal, thereby contributing to the light extraction efficiency of the light emitting device package and preventing the light luminance from being lowered.

Effects according to embodiments of the present invention are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

1 is a perspective view of a light emitting device package including a light emitting device according to the embodiment.
2A and 2B are cross-sectional views of the light emitting device package shown in FIG.
3 to 5 are cross-sectional views of electrodes according to the embodiment.
6A is a perspective view illustrating a lighting device including a light emitting device according to an embodiment.
6b is a sectional view taken along the line AA ′ of the lighting device of FIG. 6a;
7 is an exploded perspective view of a liquid crystal display including the light emitting device according to the first embodiment.
8 is an exploded perspective view of a liquid crystal display including the light emitting device according to the second embodiment.

Advantages and features of the present invention, and methods of achieving the same will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

Hereinafter, embodiments will be described with reference to the drawings for describing a light emitting device, a light emitting device package, and an illumination system.

1 is a perspective view of a light emitting device package including a light emitting device according to an embodiment, and FIGS. 2A and 2B are cross-sectional views of the light emitting device package shown in FIG. 1.

1, 2A and 2B, the light emitting device package 100 according to the embodiment includes a body 110 having a cavity formed therein, and first and second electrodes 140 and 150 mounted on the body 110. , An encapsulant 130 formed in the cavity and a light emitting device 120 electrically connected to the first and second electrodes 140 and 150, and the encapsulant 130 is a phosphor (not shown). It may include.

The body 110 is made of a resin material such as polyphthalamide (PPA), silicon (Si), aluminum (Al), aluminum nitride (AlN), photosensitive glass (PSG), polyamide 9T (PA9T) ), Neo geotactic polystyrene (SPS), a metal material, sapphire (Al2O3), beryllium oxide (BeO), a printed circuit board (PCB, Printed Circuit Board), it may be formed of at least one. The body 110 may be formed by injection molding, etching, or the like, but is not limited thereto.

The inner surface of the body 110 may be formed inclined surface. The angle of reflection of the light emitted from the light emitting device 120 may vary according to the angle of the inclined surface, thereby adjusting the directivity of the light emitted to the outside.

The shape viewed from above the cavity formed in the body 110 may be a shape such as a circle, a rectangle, a polygon, an oval, and the like, but may be a curved shape, but is not limited thereto.

The encapsulant 130 may be filled in the cavity, and may include a phosphor (not shown). The encapsulant 130 may be formed of transparent silicone, epoxy, and other resin materials, and may be formed by filling in a cavity and then UV or thermal curing.

The phosphor (not shown) may be selected according to the wavelength of light emitted from the light emitting device 120 so that the light emitting device package 100 may implement light of various wavelengths.

The phosphor (not shown) included in the encapsulant 130 may be a blue light emitting phosphor, a cyan light emitting phosphor, a green light emitting phosphor, a yellow green light emitting phosphor, a yellow light emitting phosphor, or a yellowish red light according to a wavelength of light emitted from the light emitting device 120. One of the phosphor, the orange luminescent phosphor, and the red luminescent phosphor can be applied.

That is, the phosphor (not shown) may be excited by the light having the first light emitted from the light emitting device 120 to generate the second light. For example, when the light emitting device 120 is a blue light emitting diode and the phosphor (not shown) is a yellow phosphor, the yellow phosphor may be excited by blue light to emit yellow light, and the blue light generated from the blue light emitting diode and As yellow light generated by being excited by blue light is mixed, the light emitting device package 100 may provide white light.

Similarly, when the light emitting device 120 is a green light emitting diode, when a magenta phosphor or blue and red phosphors (not shown) are mixed, when the light emitting device 120 is a red light emitting diode, a cyan phosphor or blue light is used. The case where a green fluorescent substance is mixed is mentioned as an example.

Such phosphors (not shown) may be known such as YAG-based, TAG-based, sulfide-based, silicate-based, aluminate-based, nitride-based, carbide-based, nitridosilicate-based, borate-based, fluoride-based, and phosphate-based compounds.

Meanwhile, the first electrode 140 and the second electrode 150 may be mounted on the body 110. The first electrode 140 and the second electrode 150 may be electrically connected to the light emitting device 120 to supply power to the light emitting device 120.

The first electrode 140 and the second electrode 150 are electrically separated from each other, and may reflect light generated from the light emitting device 120 to increase light efficiency, and also generate heat generated from the light emitting device 120. Can be discharged to the outside.

2A and 2B, the light emitting device 120 is mounted on the first electrode 150, but is not limited thereto. The light emitting device 120, the first electrode 140, and the second electrode 150 may be wire bonded. It may be electrically connected by any one of a wire bonding method, a flip chip method, or a die bonding method.

2A and 2B illustrate that the first electrode 140 and the second electrode 150 are bonded to the light source element 120 by the wire 155, but the present invention is not limited thereto. In particular, in the case of the vertical light emitting device, any one of the first electrode 140 and the second electrode 1500 may be bonded to the light source device 120 by the wire 155, and the wire 155 may be flipped. The light source element 120 and the first electrode 140 may be electrically connected to each other.

The first electrode 140 and the second electrode 150 are made of a metal material, for example, titanium (Ti), copper (Cu), nickel (Ni), gold (Au), chromium (Cr), and tantalum ( Ta, platinum (Pt), tin (Sn), silver (Ag), phosphorus (P), aluminum (Al), indium (In), palladium (Pd), cobalt (Co), silicon (Si), germanium ( Ge), hafnium (Hf), ruthenium (Ru), iron (Fe) may include one or more materials or alloys. In addition, the first electrode 140 and the second electrode 150 may be formed to have a single layer or a multilayer structure.

Referring to the first electrode 140 and the second electrode 150 in more detail, the first electrode 140 and the second electrode 150 are laminated with the first metal layer 210 and the second metal layer 220. It has a structure that is formed. In addition, according to the exemplary embodiment, the blocking layer 230 is interposed between the first metal layer 210 and the second metal layer 220.

The first metal layer 210 may be mainly a metal having higher electrical conductivity than the second metal layer 220, and the second metal layer 220 may have higher reflectivity than the first metal layer 210 in order to increase the light output by increasing the reflectivity. High metals can be used.

Referring to FIG. 2A, the first metal layer 210, the blocking layer 230, and the second metal layer 220 may be included in all regions of the first electrode 140 and the second electrode 150, according to an exemplary embodiment. Can be. Or referring to FIG. 2B,

According to another embodiment, the second metal layer 220 and the blocking layer 230 may be formed only in a portion of the first electrode 140 and the second electrode 150. In other words, it may be formed on the reflective region 160 shown in FIG. 2B. The reflective region 160 may be a region where the first electrode 140 and the second electrode 150 vertically overlap with the cavity of the body 110. In addition, the reflective region 160 may partially overlap the region where the inclined surface of the body 110 is formed.

The light emitting device 120 may be mounted on the first electrode 140 and may be, for example, a light emitting device emitting light of red, green, blue, white, or UV (ultra violet) light emitting device emitting ultraviolet light. However, the present invention is not limited thereto. In addition, one or more light emitting devices 120 may be mounted.

In addition, the light emitting device 120 may be a horizontal type in which all of its electrical terminals are formed on an upper surface, or a vertical type or flip chip formed on an upper and a lower surface. Applicable

On the other hand, a light extraction structure (not shown) is formed on the side of the light emitting device 120 to improve the light extraction efficiency of the light emitting device 120, thereby improving the light emitting efficiency of the light emitting device package 100.

A plurality of light emitting device packages 100 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 100.

The light emitting device package 100, the substrate, and the optical member may function as a light unit. Another embodiment may be implemented as a display device, an indicator device, or a lighting system including the light emitting device 100 or the light emitting device package 100 described in the above embodiments, for example, the lighting system may be a lamp, a street lamp. It may include.

3 to 5 show cross-sectional views of electrodes according to embodiments. Here, the electrode may be the first electrode 140 and / or the second electrode 150 of the light emitting device package described with reference to FIGS. 1A and 2B. In particular, the electrode according to the embodiment illustrated in FIGS. 3 to 5 may be used for the electrode of the reflective region 160 described above.

The electrode according to the embodiment includes a first metal layer 210 and a second metal layer 220, and a blocking layer 230 interposed between the first metal layer 210 and the second metal layer 220.

As described above, the first electrode 140 and the second electrode 150 include titanium (Ti), copper (Cu), nickel (Ni), gold (Au), chromium (Cr), tantalum (Ta), Platinum (Pt), Tin (Sn), Silver (Ag), Phosphorus (P), Aluminum (Al), Indium (In), Palladium (Pd), Cobalt (Co), Silicon (Si), Germanium (Ge), One or more metals among hafnium (Hf), ruthenium (Ru), and iron (Fe) may be used.

Since the main function of the first metal layer 210 in the first electrode 140 and the second electrode 150 is to supply power to the light emitting device 120, the first metal layer 210 has electrical conductivity among the above metals. High metals can be used predominantly. For example, the first metal layer 210 may be copper (Cu), nickel (Ni) Sn (Sn), ruthenium (Ru), iron (Fe), or the like.

On the other hand, the second metal layer 220 corresponds to a plating layer for reflection. That is, when a part of the light output from the light emitting device 120 is emitted to the rear surface, the main function of the second metal layer 220 is to reflect the light emitted to the rear surface to be emitted to the front surface again. Therefore, among the above metals, a metal having a higher reflectance than an electrical conductivity may be mainly used for the second metal layer 220. For example, gold (Au), platinum (Pt), aluminum (Al), silver (Ag), or the like may be used.

The blocking layer 230 may serve as a blocking film to prevent diffusion of metal between the first metal layer 210 and the second metal layer 220. If the first metal layer 210 and the second metal layer 220 are in direct contact without the blocking layer 230, a phenomenon in which the metal of the first metal layer 210 is diffused into the second metal layer 220 may occur. That is, diffusion may occur between metals due to the difference in concentration of metals. If the first metal layer 210 has a higher diffusion rate than the second metal layer 220, the second metal layer 220 may be discolored or deformed, and its reflection property may be impaired.

For example, when the second metal layer 220 is a silver (Ag) plating layer and the first metal layer 210 is copper (Cu), copper has a property of good diffusion and is easily oxidized compared to silver. Therefore, oxygen is attracted to the second metal layer 220 which is the silver plating layer when it is in contact with external air or moisture to promote oxidation of the silver plating layer. However, due to the properties of silver, when oxidized or copper flows, the surface is discolored and the reflectance is lowered. The drop in reflectance of the second metal layer 220 reflecting light may be connected to lowering of overall luminance of the light emitting device package.

Therefore, when the blocking layer 230 is formed between the first metal layer 210 and the second metal layer 220, the first metal may be prevented from diffusing into the second metal layer 220 or introducing oxygen or moisture. . The blocking layer 230 may be formed of a material having electrical conductivity and preventing diffusion between materials. For example, as the blocking layer 230, a metal having a lower diffusion rate than that of the first metal used in the first metal layer 210 may be used. For example, titanium (Ti), tungsten (W), Chromium (Cr), palladium (Pd), platinum (Pt), vanadium (V), iron (Fe), molybdenum (Mo) and the like may be used. In addition, if the thickness of the blocking layer 230 is too thin, the blocking layer 230 may not sufficiently perform the function of blocking metal diffusion, and if the thickness of the blocking layer 230 is too thick, the effective thickness of the electrode for power supply The result is a thinner layer, resulting in a higher resistance and resulting losses. Therefore, the preferred barrier layer may have a thickness of 1 nm to 1000 nm. In addition, it may be formed to 10nm to 100nm for the blocking function and the resistance reduction.

Referring to FIG. 4, the blocking layer 230 may have a multi-layered structure. By depositing or plating the blocking layer 230 several times, the blocking layer 230 may be formed of several layers of the first layer 231 and the second layer 235. The first layer 231 and the second layer 235 may comprise the same metal or different metals. The number of stacked layers of the blocking layer 230 or the type of metal used may be determined in consideration of improvement of a blocking function, adhesion, price, and the like.

5, the blocking layer 230 and the first metal layer 210, and the blocking layer 230 and the second metal layer 220 may be formed through the first adhesive layer 241 and the second adhesive layer 245, respectively. Can be combined. When the adhesive strength of the metal used as the blocking layer 230 is low, the first adhesive layer 241 and the second adhesive layer 245 may be formed of the first metal layer 210 and the second metal layer 220 and the blocking layer 230. It can be made of a material that increases the bonding force and at the same time does not interfere with the electrical properties. In another embodiment, only one of the first adhesive layer 241 and the second adhesive layer 245 may be included in the electrode. Due to the first adhesive layer 241 and / or the second adhesive layer 245, a blocking function of the first metal, oxygen, moisture, or the like diffused, penetrated, or introduced into the second metal layer 220 may be improved.

FIG. 6A is a perspective view illustrating a lighting device including a light emitting device according to an embodiment, and FIG. 6B is a cross-sectional view of the lighting device of FIG.

Hereinafter, in order to describe the shape of the lighting apparatus 300 according to the embodiment in more detail, the longitudinal direction (Z) of the lighting apparatus 300, the horizontal direction (Y) perpendicular to the longitudinal direction (Z), and the length The height direction X perpendicular to the direction Z and the horizontal direction Y will be described.

That is, FIG. 6B is a cross-sectional view of the lighting apparatus 300 of FIG. 6A cut in the plane of the longitudinal direction Z and the height direction X, and viewed in the horizontal direction Y. FIG.

6A and 6B, the lighting device 300 may include a body 310, a cover 330 fastened to the body 310, and a closing cap 350 positioned at both ends of the body 310. have.

The lower surface of the body 310 is fastened to the light emitting device module 340, the body 310 is conductive so that the heat generated from the light emitting device module 340 can be discharged to the outside through the upper surface of the body 310 And it may be formed of a metal material having an excellent heat dissipation effect.

The light emitting device module 340 includes a light emitting device package 344 including a PCB substrate 342 and a light emitting device (not shown), and the light emitting device package 344 is multicolored and multi-colored on the PCB substrate 342. It can be mounted to form an array, and can be mounted at equal intervals or mounted at various separation distances as needed to adjust brightness and the like. The PCB substrate 342 may be a metal core PCB (MCPCB) or a PCB made of FR4.

The cover 330 may be formed in a circular shape to surround the lower surface of the body 310, but is not limited thereto.

The cover 330 protects the light emitting device module 340 from the outside and the like. In addition, the cover 330 may include diffusing particles to prevent glare of the light generated from the light emitting device package 344, and to uniformly emit light to the outside, and at least of the inner and outer surfaces of the cover 330 A prism pattern or the like may be formed on either side. In addition, a phosphor may be applied to at least one of an inner surface and an outer surface of the cover 330.

On the other hand, since the light generated from the light emitting device package 344 is emitted to the outside through the cover 330, the cover 330 should have excellent light transmittance, and has sufficient heat resistance to withstand the heat generated by the light emitting device package 344. The cover 330 is preferably formed of a material including polyethylene terephthalate (PET), polycarbonate (PC), polymethyl methacrylate (PMMA), or the like. .

Closing cap 350 is located at both ends of the body 310 may be used for sealing the power supply (not shown). In addition, the closing cap 350 is formed with a power pin 352, the lighting device 300 according to the embodiment can be used immediately without a separate device to the terminal from which the existing fluorescent lamps are removed.

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

7 illustrates an edge-light method, the liquid crystal display device 400 may include a liquid crystal display panel 410 and a backlight unit 470 for providing light to the liquid crystal display panel 410.

The liquid crystal display panel 410 may display an image using light provided from the backlight unit 470. The liquid crystal display panel 410 may include a color filter substrate 412 and a thin film transistor substrate 414 facing each other with the liquid crystal interposed therebetween.

The color filter substrate 412 may implement a color of an image displayed through the liquid crystal display panel 410.

The thin film transistor substrate 414 is electrically connected to the printed circuit board 418 on which a plurality of circuit components are mounted through the driving film 417. The thin film transistor substrate 414 may apply a driving voltage provided from the printed circuit board 418 to the liquid crystal in response to a driving signal provided from the printed circuit board 418.

The thin film transistor substrate 414 may include a thin film transistor and a pixel electrode formed of a thin film on another substrate of a transparent material such as glass or plastic.

The backlight unit 470 may convert the light provided from the light emitting device module 420, the light emitting device module 420 into a surface light source, and provide the light guide plate 430 to the liquid crystal display panel 410. Reflective sheet reflecting the light emitted to the light guide plate 430 to the plurality of films 450, 466, 464 and the light guide plate 430 to uniform the luminance distribution of the light provided from the light source 430 and to improve vertical incidence ( 440).

The light emitting device module 420 may include a PCB substrate 322 such that a plurality of light emitting device packages 424 and a plurality of light emitting device packages 424 are mounted to form an array.

Meanwhile, the light emitting device included in the light emitting device package 424 is omitted as described above with reference to FIG. 1.

On the other hand, the backlight unit 470 is a diffusion film 466 for diffusing light incident from the light guide plate 430 toward the liquid crystal display panel 410, and a prism film 450 for condensing the diffused light to improve vertical incidence. It may be configured as), and may include a protective film 464 for protecting the prism film 450.

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

However, the parts shown and described in FIG. 7 will not be repeatedly described in detail.

8 is a direct view, the liquid crystal display device 500 may include a liquid crystal display panel 510 and a backlight unit 570 for providing light to the liquid crystal display panel 510.

Since the liquid crystal display panel 510 is the same as that described with reference to FIG. 7, a detailed description thereof will be omitted.

The backlight unit 570 includes a plurality of light emitting device modules 523, a reflective sheet 524, a lower chassis 530 in which the light emitting device modules 523 and the reflective sheet 524 are accommodated, and an upper portion of the light emitting device module 523. It may include a diffusion plate 540 and a plurality of optical film 560 disposed in the.

Light emitting device module 523 A plurality of light emitting device packages 522 and a plurality of light emitting device packages 522 may be mounted to include a PCB substrate 521 to form an array.

The reflective sheet 524 reflects the light generated from the light emitting device package 522 in the direction in which the liquid crystal display panel 510 is located to improve light utilization efficiency.

Meanwhile, the light generated by the light emitting device module 523 is incident on the diffusion plate 540, and the optical film 560 is disposed on the diffusion plate 540. The optical film 560 may include a diffusion film 566, a prism film 550, and a protective film 564.

In an embodiment, the lighting device and the backlight unit may be included in the lighting system, but are not limited thereto.

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

In addition, the above description has been made with reference to the embodiment, which is merely an example, and is not intended to limit the present invention. It will be appreciated 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 device package 110: the body
120: light emitting element 130: sealing material
140: first electrode 150: second electrode
210: first metal layer 220: second metal layer
230: blocking layer

Claims (8)

A cavity formed body;
A light emitting device provided on the body; And
First and second electrodes provided on the body and connected to the light emitting device; Including,
The first electrode and the second electrode
A first metal layer made of a first metal;
A second metal layer made of a second metal having a higher reflectance than the first metal; And
And a blocking layer blocking diffusion of the metal between the first metal layer and the second metal layer and having a diffusion rate lower than that of the first metal. The method of claim 1,
The blocking layer is
A light emitting device package formed of at least one metal of titanium (Ti), tungsten (W), chromium (Cr), palladium (Pd), platinum (Pt), vanadium (V), iron (Fe), and molybdenum (Mo). The method of claim 1,
The blocking layer has a thickness of less than 1nm 1000nm light emitting device package. The method of claim 1,
The blocking layer has a thickness of less than 10nm 100nm light emitting device package. The method of claim 1,
The blocking layer is coupled to at least one of the first metal layer and the second metal layer and the light emitting device package. The method of claim 2,
The blocking layer is a light emitting device package comprising a first layer and a second layer. The method of claim 1,
The second metal layer is a light emitting device package formed in the reflective region partially overlapping with the cavity of the light emitting device package. The method of claim 7, wherein
The blocking layer is formed in the reflective region, the light emitting device package surrounding the second metal layer from the first metal layer.

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