KR20150017920A - Light emitting device package - Google Patents

Abstract

The embodiment of the present invention relates to a light emitting device package and a lighting system. The light emitting device package according to the embodiment of the present invention includes a package body, a groove which is formed on the upper side of the package body, and a light emitting device which includes a bonding pad and is arranged on the package body. At least part of the bonding pad of the light emitting device is located in the groove.

Description

[0001] LIGHT EMITTING DEVICE PACKAGE [0002]

Embodiments relate to a light emitting device package and an illumination system.

Light Emitting Device is a pn junction diode whose electrical energy is converted into light energy. It can be produced from compound semiconductor such as group III and group V on the periodic table and by controlling the composition ratio of compound semiconductor, It is possible.

When a forward voltage is applied to the light emitting device, electrons in the n-layer and holes in the p-layer are coupled to emit energy corresponding to the band gap energy of the conduction band and the valance band. Is mainly emitted in the form of heat or light, and when emitted in the form of light, becomes a light emitting element.

For example, nitride semiconductors have received great interest in the development of optical devices and high power electronic devices due to their high thermal stability and wide bandgap energy. Particularly, blue light emitting devices, green light emitting devices, ultraviolet (UV) light emitting devices, and the like using nitride semiconductors have been commercialized and widely used.

There is a flip chip package structure in the conventional light emitting device package technology.

However, the conventional flip-chip package structure has a disadvantage in that only a cross-sectional area of a bonding pad is in contact with a package sub-mount, and heat is not easily emitted.

In addition, according to the related art, there is a problem that the contact force with the submount of the flip chip package structure is low and reliability is lowered.

Embodiments provide a light emitting device package and an illumination system capable of maximizing heat dissipation efficiency by widening an area of contact between a bonding pad and a package body.

In addition, the embodiment is intended to provide a light emitting device package and an illumination system capable of improving the contact force of the light emitting device and increasing the reliability.

A light emitting device package according to an embodiment includes a package body; A groove formed on an upper surface of the package body; And a light emitting device having a bonding pad and disposed on the package body, and at least a part of the bonding pad of the light emitting device may be located inside the groove.

Further, the illumination system according to the embodiment may include a light emitting unit having the light emitting device package.

In the embodiment, the grooves are provided in the package body corresponding to the bonding pads of the light emitting device to bond the bonding pads to the inside of the package body grooves, thereby widening the contact area between the bonding pads and the package body, thereby maximizing heat dissipation efficiency have.

According to the embodiment, the bonding pad is bonded to the inside of the package body groove to widen the contact area between the bonding pad and the package body, and the inner wall of the groove supports the bonding pad, thereby greatly increasing the contact force of the light emitting device, .

In addition, according to the embodiment, when the bonding pad of the light emitting element has a thickness of 100 mu m using the electrolytic plating method, there is an effect of higher heat radiation efficiency and higher adhesiveness than the conventional structure.

1A is a cross-sectional view of a light emitting device package according to a first embodiment;
1B is another exemplary sectional view of a light emitting device package according to the first embodiment.
2 to 4 are cross-sectional views illustrating a method of manufacturing a light emitting device package according to an embodiment.
5 is a cross-sectional view of a light emitting device package according to a second embodiment;
6 is an exploded perspective view of a lighting apparatus according to an embodiment;

In the description of the embodiments, it is to be understood that each layer (film), area, pattern or structure may be referred to as being "on" or "under" the substrate, each layer Quot; on "and" under "are intended to include both" directly "or" indirectly " do. Also, the criteria for top, bottom, or bottom of each layer will be described with reference to the drawings.

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

(Example)

1A is a cross-sectional view of a light emitting device package 200 according to the first embodiment.

The light emitting device package 200 according to the embodiment includes a package body 205 having a cavity C and a groove H and a bonding pad 120 formed on a bottom surface of the cavity C, The light emitting device 100 may include a light emitting device 100 disposed on the light emitting device.

Embodiments provide a light emitting device package and an illumination system capable of maximizing heat dissipation efficiency by significantly widening an area where a bonding pad and a package body contact with each other.

In addition, the embodiment is intended to provide a light emitting device package and an illumination system capable of improving the contact force of the light emitting device and increasing the reliability.

For this, the bonding pads 120 of the light emitting devices may be disposed in the grooves H in the embodiment. The bonding pad 120 may include a first bonding pad 121 and a second bonding pad 122.

The bottom surface of the bonding pad 120 may be lower than the bottom surface of the cavity C and the electrode 210 disposed on the bottom surface of the package body 205 may be exposed by the groove H, have.

The bonding pad 120 may be electrically connected to the electrode 210 in the groove H. The electrode 210 may include a first electrode 211 and a second electrode 212.

The first electrode 211 and the second electrode 212 may be electrically connected to the first bonding pad 121 and the second bonding pad 122, respectively.

In addition, in the embodiment, the electrode 210 may include extension parts 211a and 212a projecting upward from the bottom surface of the package body 205. The extension may be referred to as a protrusion. And may include a side extension of the first electrode 211 and the second electrode 212 in the embodiment.

According to the embodiment, as shown in FIG. 1A, the extension portions 211a and 212a may be formed by bending the end portion of the electrode 210, and the upper extension portion may be provided, but the side extension portion may not be provided.

The extension portions 211a and 212a of the electrode 210 may overlap with the bonding pad 120 in the vertical direction. For example, the extension part 211a of the first electrode and the extension part 212a of the second electrode may be overlapped with the first bonding pad 121 and the second bonding pad 122, respectively, have.

The upper surfaces of the extension portions 211a and 212a of the electrode 210 are disposed lower than the bottom surface of the cavity C so that the bonding pad 120 can be firmly fixed in the groove H. [

According to the embodiment, the grooves are provided in the package body corresponding to the bonding pads of the light emitting device to bond the bonding pads to the inside of the package body grooves, thereby widening the contact area between the bonding pads and the package body, thereby maximizing heat dissipation efficiency. .

According to the embodiment, the bonding pad is bonded to the inside of the package body groove to widen the contact area between the bonding pad and the package body, and the inner wall of the groove supports the bonding pad, thereby greatly increasing the contact force of the light emitting device, .

The bonding pads 120 may be in contact with the inner side surfaces of the grooves H in the embodiment. Accordingly, not only the bottom surface but also the side surface of the bonding pad 120 are in contact with the package body 205, so that the groove side walls of the package body support the bonding pad, thereby greatly increasing the contact force of the light emitting device. In addition, the area of contact between the bonding pad and the package body is significantly increased, thereby maximizing heat dissipation efficiency.

In an embodiment, the bonding pad 120 may have a height A of 100 m or more. For example, the height of the first bonding pad 121 may be 100 탆 or more, but the present invention is not limited thereto.

Thus, according to the embodiment, even when the bonding pad of the light emitting device has a thickness of 100 mu m using the electrolytic plating method, the heat radiation efficiency and adhesiveness are higher than those of the conventional structure.

In the embodiment, a conductive adhesive material may be disposed in the groove H, and the conductive adhesive material may be solidified by applying heat in a paste (not shown), physically and electrically coupling the light emitting device and the electrode, Therefore, the conductivity and the heat radiation efficiency can be increased, but not limited thereto.

For example, the paste (not shown) may be one or more than one selected from the group consisting of Al, Ti, Cr, Ni, Pt, Au, W, Cu and Mo.

The embodiment has a groove in the package body in a region corresponding to the bonding pad of the light emitting device so that the bonding pad is bonded to the inside of the package body groove to widen the contact area between the bonding pad and the package body, .

According to the embodiment, the bonding pad is bonded to the inside of the package body groove to widen the contact area between the bonding pad and the package body, and the inner wall of the groove supports the bonding pad, thereby greatly increasing the contact force of the light emitting device, .

In addition, according to the embodiment, the bonding pads of the light emitting device are formed to have a thickness of 100 mu m which is thicker than the conventional structure by using the electrolytic deposition method, so that the heat radiation efficiency and adhesiveness are higher than those of the conventional structure.

Hereinafter, a method of manufacturing a light emitting device package according to an embodiment will be described with reference to FIGS.

First, the light emitting device 100 is formed as shown in FIG. For example, as shown in FIG. 2, the light emitting device 100 may be a flip-chip type light emitting device as a horizontal type light emitting device, but the present invention is not limited thereto.

The light emitting device 100 may include a growth substrate 105, a light emitting structure 110, and a bonding pad 120.

The growth substrate 105 supports the light emitting structure 110 while growing the light emitting structure 110 and may be formed of a material suitable for growth of the light emitting structure 110. The growth substrate 105 may be formed of a material similar to the lattice constant of the light emitting structure 110 and having thermal stability, and may be one of a conductive substrate, a compound semiconductor substrate, and an insulating substrate, but the present invention is not limited thereto .

For example, the growth substrate 105 may be formed of at least one selected from the group consisting of sapphire (Al ₂ O ₃ ), SiC, Si, GaAs, GaN, ZnO, GaP, InP and Ge.

Although not shown, the light emitting device 100 may further include a buffer layer (not shown) formed between the growth substrate 105 and the light emitting structure 110. The buffer layer may alleviate a lattice constant difference between the growth substrate 105 and the light emitting structure 110.

The light emitting structure 110 may include a plurality of compound semiconductor layers. The light emitting structure 110 may include at least a first conductive semiconductor layer 112, an active layer 114, and a second conductive semiconductor layer 116, but the present invention is not limited thereto.

The buffer layer, the first conductivity type semiconductor layer 112, the active layer 114 and the second conductivity type semiconductor layer 116 are made of a II-VI or III-V compound semiconductor material, that is, Al _x In _y Ga _(1-xy) N (0 <x <1, 0 <y <1, 0 <x + y <1).

For example, the buffer layer, the first conductivity type semiconductor layer 112, the active layer 114, and the second conductivity type semiconductor layer 116 may be formed from a group consisting of InAlGaN, GaN, AlGaN, InGaN, AlN, InN, and AlInN But it is not limited thereto.

The first conductive semiconductor layer 112 may be an n-type semiconductor layer including an n-type dopant, and the second conductive semiconductor layer 116 may be a p-type semiconductor layer including a p-type dopant. I never do that.

The n-type dopant includes at least one of Si, Ge, Sn, Se and Te, and the p-type dopant includes at least one of Mg, Zn, Ca, Sr and Ba.

The active layer 114 is formed between the first and second conductivity type semiconductor layers 112 and 116 so that the electrons of the first conductivity type semiconductor layer 112 and the electrons of the second conductivity type semiconductor layer 116 It is possible to emit light having a wavelength corresponding to an energy band gap according to the material of the active layer 114 by recombination of holes.

The active layer 114 may include any one of a multiple quantum well structure (MQW), a quantum dot structure, and a quantum wire structure. The active layer 114 can be formed by repeatedly forming the well layer and the barrier layer with the well layer and the barrier layer as one cycle. The repetition period of the well layer and the barrier layer may be changed according to the characteristics of the light emitting device 100, and thus the present invention is not limited thereto.

The active layer 114 may be formed of, for example, a period of InGaN / GaN, a period of InGaN / AlGaN, a period of InGaN / InGaN, or the like. The band gap of the barrier layer may be formed to be larger than the band gap of the well layer.

The first bonding pad 121 is formed on a portion of the first conductive type semiconductor layer 112 and the second bonding pad 122 is formed on a portion of the second conductive type semiconductor layer 116 As shown in FIG.

Each of the first and second bonding pads 121 and 122 may include one or a multilayer structure selected from the group consisting of Al, Ti, Cr, Ni, Pt, Au, W, Cu and Mo, Not limited.

A passivation 130 may be formed of an insulating material such as oxide or nitride between the bonding pads 120 on the light emitting structure 110.

In an embodiment, the bonding pad 120 may have a height A of 100 m or more. Thus, according to the embodiment, when the bonding pad of the light emitting device has a thickness of 100 탆 using the electrolytic plating method, there is an effect of higher heat radiation efficiency and higher adhesiveness than the conventional structure.

Next, as shown in Fig. 3, a package body 205 having a cavity C is prepared.

The package body 205 supports the light emitting device 100 and may be electrically connected to the light emitting device 100. For this, the first and second electrodes 211 and 212 may be formed on the package body 205.

The package body 205 is formed of a material having excellent support strength and excellent heat radiation performance, but the present invention is not limited thereto. For example, the package body 205 may be formed of a silicon material, a synthetic resin material, a ceramic material, or a metal material.

The upper portion of the package body 205 may be formed with a cavity C having an inclined surface and recessed in the downward direction, but the present invention is not limited thereto. That is, the cavity C may include a sloped surface and a flat bottom surface, but the present invention is not limited thereto.

The embodiment may form a groove (H) on the bottom surface of the cavity (C). The grooves H may be formed in plural. For example, the groove H may include a first groove H1 and a second groove H2, but the present invention is not limited thereto.

The electrode 210 can be formed with the top surface exposed by the groove H. The electrode 210 may include a first electrode 211 and a second electrode 212, but the present invention is not limited thereto.

In addition, in the embodiment, the electrode 210 may include extension portions 211a and 212a in the upward direction from the bottom surface of the package body 205.

The extension portions 211a and 212a of the electrode 210 may overlap with the bonding pad 120 in the vertical direction.

The upper surfaces of the extension portions 211a and 212a of the electrode 210 are disposed lower than the bottom surface of the cavity C so that the bonding pad 120 can be firmly fixed in the groove H. [

The first electrode 211 and the second electrode 212 may be electrically separated from each other and may be spaced apart from each other.

The first electrode 211 and the second electrode 212 may be formed through the package body 205. That is, the first electrode 211 and the second electrode 212 may be formed on the rear surface of the package body 205, and may extend through the package body 205. The first electrode 211 and the second electrode 212 may be formed to penetrate the package body 205 vertically or obliquely.

The first electrode 211 and the second electrode 212 may be formed of a metal material having excellent electrical conductivity and high corrosion resistance such as Cu, Al, Cr, Pt, Ni, Ti, Au, It is not limited.

A material for forming the package body 205 is injected and cured using the molding injection process in a state where the first electrode 211 and the second electrode 212 are positioned to form the package body 205, The first electrode 211 and the second electrode layer 212 may be fixed to the package body 205, but the present invention is not limited thereto.

The first electrode 211 and the second electrode layer 212 may include a single layer or multiple layers, but the present invention is not limited thereto.

The contact force, the conductivity and the heat radiation efficiency can be increased by physically and electrically bonding the electrode 210 and the light emitting element through a sintering process using a conductive paste (not shown) in the groove H in the embodiment, But is not limited thereto.

For example, the paste (not shown) may be one or more than one selected from the group consisting of Al, Ti, Cr, Ni, Pt, Au, W, Cu and Mo.

Next, the light emitting device 100 is mounted on the package body 205 as shown in FIG.

In this case, the bonding pads 120 of the light emitting device may be disposed in the grooves H in the embodiment.

The bottom surface of the bonding pad 120 may be positioned lower than the bottom surface of the cavity C and the electrode 210 disposed on the bottom surface of the package body 205 may be exposed have.

The bonding pad 120 may be electrically connected to the electrode 210 in the groove H.

Accordingly, in the embodiment, the grooves are provided in the package body corresponding to the bonding pads of the light emitting device to bond the bonding pads to the inside of the package body grooves, thereby widening the contact area between the bonding pads and the package body, thereby maximizing heat dissipation efficiency .

According to the embodiment, the bonding pad is bonded to the inside of the package body groove to widen the contact area between the bonding pad and the package body, and the inner wall of the groove supports the bonding pad, thereby greatly increasing the contact force of the light emitting device, .

The bonding pads 120 may be in contact with the inner side surfaces of the grooves H in the embodiment. Accordingly, not only the bottom surface but also the side surface of the bonding pad 120 are in contact with the package body 205, so that the groove side wall of the package body supports the bonding pad, thereby greatly enhancing the contact force of the light emitting device. In addition, the area of contact between the bonding pad and the package body is significantly increased, thereby maximizing heat dissipation efficiency.

5 is a cross-sectional view of a light emitting device package 202 according to the second embodiment.

The second embodiment can employ the technical features of the first embodiment.

In the second embodiment, the electrode 230 may penetrate the side surface of the package body 205.

For example, the electrode 230 may include a third electrode 231 and a fourth electrode 232, and a third electrode 231 and a fourth electrode 232 may be formed on the package body 205 But it is not limited thereto, and may be shaped to penetrate through the side surface and to surround the bottom surface of the package body 205.

The bonding pad 120 may be in contact with the third electrode 231 and the fourth electrode 232 and may include a third electrode 231 and a fourth electrode 232 rather than a bottom surface of the bonding pad 120, So that the bonding force with the bonding pad 120 can be further strengthened.

In the embodiment, the grooves are provided in the package body corresponding to the bonding pads of the light emitting device to bond the bonding pads to the inside of the package body grooves, thereby widening the contact area between the bonding pads and the package body, thereby maximizing heat dissipation efficiency have.

According to the embodiment, the bonding pad is bonded to the inside of the package body groove to widen the contact area between the bonding pad and the package body, and the inner wall of the groove supports the bonding pad, thereby greatly increasing the contact force of the light emitting device, .

In addition, according to the embodiment, when the bonding pad of the light emitting element has a thickness of 100 mu m using the electrolytic plating method, there is an effect of higher heat radiation efficiency and higher adhesiveness than the conventional structure.

6 is an exploded perspective view of an illumination system according to an embodiment.

6, the illumination system according to the embodiment may include a cover 2100, a light source module 2200, a heat sink 2400, a power supply unit 2600, an inner case 2700, a socket 2800 have. Further, the illumination device according to the embodiment may further include at least one of the member 2300 and the holder 2500. The light source module 2200 may include the light emitting device 100 or the light emitting device package 200 according to the present invention.

For example, the cover 2100 may have a shape of a bulb or a hemisphere, and may be provided in a shape in which the hollow is hollow and a part is opened. The cover 2100 may be optically coupled to the light source module 2200. For example, the cover 2100 may diffuse, scatter, or excite light provided from the light source module 2200. The cover 2100 may be a kind of optical member. The cover 2100 may be coupled to the heat discharging body 2400. The cover 2100 may have an engaging portion that engages with the heat discharging body 2400.

The inner surface of the cover 2100 may be coated with a milky white paint. Milky white paints may contain a diffusing agent to diffuse light. The surface roughness of the inner surface of the cover 2100 may be larger than the surface roughness of the outer surface of the cover 2100. This is for sufficiently diffusing and diffusing the light from the light source module 2200 and emitting it to the outside.

The cover 2100 may be made of glass, plastic, polypropylene (PP), polyethylene (PE), polycarbonate (PC), or the like. Here, polycarbonate is excellent in light resistance, heat resistance and strength. The cover 2100 may be transparent so that the light source module 2200 is visible from the outside, and may be opaque. The cover 2100 may be formed by blow molding.

The light source module 2200 may be disposed on one side of the heat discharging body 2400. Accordingly, heat from the light source module 2200 is conducted to the heat discharger 2400. The light source module 2200 may include a light source unit 2210, a connection plate 2230, and a connector 2250.

The member 2300 is disposed on the upper surface of the heat discharging body 2400 and has guide grooves 2310 through which the plurality of light source portions 2210 and the connector 2250 are inserted. The guide groove 2310 corresponds to the substrate of the light source unit 2210 and the connector 2250.

The surface of the member 2300 may be coated or coated with a light reflecting material. For example, the surface of the member 2300 may be coated or coated with a white paint. The member 2300 reflects the light reflected by the inner surface of the cover 2100 toward the cover 2100 in the direction toward the light source module 2200. Therefore, the light efficiency of the illumination device according to the embodiment can be improved.

The member 2300 may be made of an insulating material, for example. The connection plate 2230 of the light source module 2200 may include an electrically conductive material. Therefore, electrical contact can be made between the heat discharging body 2400 and the connecting plate 2230. The member 2300 may be formed of an insulating material to prevent an electrical short circuit between the connection plate 2230 and the heat discharging body 2400. The heat discharger 2400 receives heat from the light source module 2200 and heat from the power supply unit 2600 to dissipate heat.

The holder 2500 blocks the receiving groove 2719 of the insulating portion 2710 of the inner case 2700. Therefore, the power supply unit 2600 housed in the insulating portion 2710 of the inner case 2700 is sealed. The holder 2500 has a guide protrusion 2510. The guide protrusion 2510 has a hole through which the protrusion 2610 of the power supply unit 2600 passes.

The power supply unit 2600 processes or converts an electrical signal provided from the outside and provides the electrical signal to the light source module 2200. The power supply unit 2600 is housed in the receiving groove 2719 of the inner case 2700 and is sealed inside the inner case 2700 by the holder 2500.

The power supply unit 2600 may include a protrusion 2610, a guide 2630, a base 2650, and an extension 2670.

The guide portion 2630 has a shape protruding outward from one side of the base 2650. The guide portion 2630 may be inserted into the holder 2500. A plurality of components may be disposed on one side of the base 2650. The plurality of components include, for example, a DC converter for converting AC power supplied from an external power source into DC power, a driving chip for controlling driving of the light source module 2200, an ESD (ElectroStatic discharge) protective device, and the like, but the present invention is not limited thereto.

The extension portion 2670 has a shape protruding outward from the other side of the base 2650. The extension portion 2670 is inserted into the connection portion 2750 of the inner case 2700 and receives an external electrical signal. For example, the extension portion 2670 may be provided to be equal to or smaller than the width of the connection portion 2750 of the inner case 2700. One end of each of the positive wire and the negative wire is electrically connected to the extension portion 2670 and the other end of the positive wire and the negative wire are electrically connected to the socket 2800 .

The inner case 2700 may include a molding part together with the power supply part 2600. The molding part is a hardened portion of the molding liquid so that the power supply unit 2600 can be fixed inside the inner case 2700.

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 can be combined and modified by other persons skilled in the art to which the embodiments belong. Accordingly, the contents of such combinations and modifications should be construed as being included in the scope of the embodiments.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention. It can be seen that the modification and application of branches are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that the present invention may be embodied in many other specific forms without departing from the spirit or essential characteristics thereof.

The cavity C, the package body 205, the groove H, the bonding pad 120, the light emitting device 100,

Claims (11)

A package body;
A groove formed on an upper surface of the package body; And
And a light emitting device having a bonding pad and disposed on the package body,
Wherein at least a part of the bonding pad of the light emitting element is located inside the groove. The method according to claim 1,
Wherein the package body has a predetermined cavity,
Wherein a bottom surface of the bonding pad is disposed lower than a bottom surface of the cavity. The method according to claim 1,
And an electrode disposed on the bottom surface of the package body is exposed by the groove. The method of claim 3,
The bonding pad
And electrically connected to the electrode in the groove. The method according to claim 1,
The bonding pad
And the light emitting device package is in contact with the inner side surface of the groove. The method according to claim 1,
The bonding pad
And a height of 100 mu m or more. The method according to claim 1,
The electrode
And an extending portion extending upward from a bottom surface of the package body. 8. The method of claim 7,
Wherein an extension of the electrode overlaps with the bonding pad vertically. 8. The method of claim 7,
The upper surface of the extension of the electrode
Wherein the light emitting device package is disposed lower than the upper surface of the package body. The method according to claim 1,
The electrode
Wherein the light emitting device package comprises: a light emitting device package having a light emitting device package; The method according to claim 1,
The package body
A wall surrounding the edge of the package body, and a cavity formed by the wall and the bottom surface of the package body.

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