KR102075749B1 - Light emitting device package - Google Patents

Abstract

Embodiments relate to a light emitting device package and an illumination system.
The light emitting device package according to the 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, wherein at least a portion of the bonding pad of the light emitting device may be located inside the groove.

Description

Light emitting device package {LIGHT EMITTING DEVICE PACKAGE}

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

Light Emitting Device is a pn junction diode that converts electrical energy into light energy, and can be made of compound semiconductors such as group III and group V on the periodic table. It is possible.

When the forward voltage is applied, the n-layer electrons and the p-layer holes combine to emit energy corresponding to the bandgap energy of the conduction band and the valence band. Is mainly emitted in the form of heat or light, and emits light in the form of light emitting elements.

For example, nitride semiconductors are receiving great attention in the field of optical devices and high power electronic devices due to their high thermal stability and wide bandgap energy. In particular, blue light emitting devices, green light emitting devices, and ultraviolet light emitting devices using nitride semiconductors are commercially used and widely used.

There is a package structure of a flip chip in the light emitting device package technology according to the prior art.

However, the flip chip package structure of the related art has a disadvantage in that heat dissipation is not easy because only the cross-sectional area of the bonding pad is in contact with the package sub-mount.

In addition, according to the prior art, there is a problem in that the contact force with the submount of the flip chip package structure is low, thereby lowering reliability.

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

In addition, the embodiment is to provide a light emitting device package and lighting system that can be improved by improving the contact force of the light emitting device.

The light emitting device package according to the 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, wherein at least a portion of the bonding pad of the light emitting device may be located inside the groove.

In addition, the lighting system according to the embodiment may include a light emitting unit having the light emitting device package.

The embodiment has a groove in the package body of a region corresponding to the bonding pad of the light emitting device to bond the bonding pad to the inside of the package body groove, thereby significantly increasing the area where the bonding pad and the package body come into contact with each other to maximize heat dissipation efficiency. have.

In addition, according to the embodiment, by bonding the bonding pad to the inside of the package body groove, the bonding pad and the package body may be contacted with each other, and the groove inner wall may support the bonding pad, thereby greatly improving the contact force of the light emitting device, thereby increasing reliability. .

In addition, according to the embodiment, when the bonding pad of the light emitting device has a thick thickness of 100 μm using the electroplating method, there is a higher heat dissipation 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 cross-sectional view of the light emitting device package according to the first embodiment.
2 to 4 are cross-sectional views of 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 the second embodiment.
6 is an exploded perspective view of the lighting apparatus according to the embodiment.

In the description of an embodiment, each layer (film), region, pattern, or structure is “on / over” or “under” the substrate, each layer (film), region, pad, or pattern. In the case where it is described as being formed at, "on / over" and "under" include both "directly" or "indirectly" formed. do. In addition, the criteria for the above / above or below each layer will be described with reference to the drawings.

In the drawings, the thickness or size of each layer is exaggerated, omitted, or schematically illustrated for convenience and clarity of description. In addition, the size of each component does not necessarily 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, a groove H and a bonding pad 120 formed on a bottom surface of the cavity C, and the cavity (C). It may include a light emitting device 100 disposed on C).

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

In addition, the embodiment is to provide a light emitting device package and lighting system that can be improved by improving the contact force of the light emitting device.

For this purpose, the bonding pad 120 of the light emitting device may be disposed in the groove H. The bonding pad 120 may include a first bonding pad 121 and a second bonding pad 122.

In addition, the bottom surface of the bonding pad 120 may be formed lower than the bottom surface of the cavity C, and the groove 210 may expose the electrode 210 disposed on the bottom surface of the package body 205. 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.

Accordingly, 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 211b and 212a protruding upward from the bottom surface of the package body 205. The extension may also be called a protrusion. In an embodiment, the first electrode 211 and the second electrode 212 may include side extensions.

Meanwhile, according to an embodiment, as shown in FIG. 1A, the extension parts 211b and 212a may be formed by bending end portions of the electrode 210, and an upper extension part may be provided but no side extension part.

The extension parts 211b and 212a of the electrode 210 may overlap the bonding pad 120 vertically. For example, the extension part 211b of the first electrode and the extension part 212a of the second electrode may overlap with each other between the first bonding pad 121 and the second bonding pad 122. have.

In an embodiment, upper surfaces of the extension parts 211b and 212a of the electrode 210 may be lower than the bottom surface of the cavity C so that the bonding pad 120 may be firmly fixed in the groove H.

According to the embodiment, a groove is provided in the package body in a region corresponding to the bonding pad of the light emitting device to bond the bonding pad to the inside of the package body groove, thereby significantly increasing the contact area between the bonding pad and the package body to maximize heat dissipation efficiency. Can be.

In addition, according to the embodiment, by bonding the bonding pad to the inside of the package body groove, the bonding pad and the package body may be contacted with each other, and the groove inner wall may support the bonding pad, thereby greatly improving the contact force of the light emitting device, thereby increasing reliability. .

In an embodiment, the bonding pad 120 may be in contact with an inner side surface of the groove H. Accordingly, by contacting the bottom surface as well as the bottom of the bonding pad 120 with the package body 205, the groove sidewall of the package body supports the bonding pad, thereby greatly improving the contact force of the light emitting device, thereby increasing reliability. In addition, it is possible to maximize the heat dissipation efficiency by significantly widening the contact area between the bonding pad and the package body.

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

Accordingly, according to the embodiment, even when the bonding pad of the light emitting device has a thick thickness of 100 μm using the electroplating method, there is a higher heat dissipation efficiency and higher adhesiveness than the conventional structure.

In an embodiment, a conductive adhesive material may be located inside the groove H. The conductive adhesive material is solidified by applying heat in a paste (not shown) and simultaneously physically and electrically couples the light emitting device and the electrode. Therefore, the conductivity and heat dissipation efficiency can be increased, but is not limited thereto.

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

According to the embodiment, a groove is provided in the package body in a region corresponding to the bonding pad of the light emitting device, thereby bonding the bonding pad to the inside of the package body groove, thereby significantly widening the contact area between the bonding pad and the package body, thereby maximizing heat dissipation efficiency. .

In addition, according to the embodiment, by bonding the bonding pad to the inside of the package body groove, the bonding pad and the package body may be contacted with each other, and the groove inner wall may support the bonding pad, thereby greatly improving the contact force of the light emitting device, thereby increasing reliability. .

In addition, according to the embodiment, the bonding pad of the light emitting device has a thickness of 100 μm thicker than that of the conventional structure by using an electrolytic coating method, and thus has higher heat dissipation efficiency and higher adhesiveness than the conventional structure.

Hereinafter, a method of manufacturing a light emitting device package according to an embodiment will be described with reference to FIGS. 2 to 4.

First, the light emitting device 100 is formed as shown in FIG. 2. For example, as shown in FIG. 2, the light emitting device 100 may be a flip-chip type light emitting device as a horizontal light emitting device, but 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 serves to support 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 a thermal stability, and may be one of a conductive substrate, a compound semiconductor substrate, and an insulating substrate, but 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 the 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 conductivity type semiconductor layer 112, an active layer 114, and a second conductivity type semiconductor layer 116, but 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 may be formed 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. It may include at least one selected, but 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, but is not limited thereto. 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, but is not limited to, 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 to form electrons of the first conductivity type semiconductor layer 112 and the second conductivity type semiconductor layer 116. Recombination of the holes may emit light having a wavelength corresponding to an energy band gap depending on the material of the active layer 114.

The active layer 114 may include any one of a multi quantum well structure (MQW), a quantum dot structure, or a quantum line structure. The active layer 114 may have a well layer and a barrier layer repeatedly formed with a well layer and a barrier layer as a cycle. The repetition period of the well layer and the barrier layer may be modified according to the characteristics of the light emitting device 100, and the present invention is not limited thereto.

The active layer 114 may be formed by, 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 larger than the band gap of the well layer.

The first bonding pad 121 is formed on a portion of the first conductive semiconductor layer 112, and the second bonding pad 122 is on a portion of the second conductive semiconductor layer 116. Can be formed on.

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

The passivation 130 may be formed of an insulating material such as an 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 μm or more. Accordingly, according to the embodiment, when the bonding pad of the light emitting device has a thick thickness of 100 μm using the electroplating method, there is a higher heat dissipation efficiency and higher adhesiveness than the conventional structure.

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

The package body 205 may serve to support the light emitting device 100 and may be electrically connected to the light emitting device 100. To this end, the first and second electrodes 211 and 212 may be formed in the package body 205.

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

A cavity C having an inclined surface and recessed in a lower direction may be formed in an upper region of the package body 205, but is not limited thereto. That is, the cavity C may include an inclined slope and a flat bottom surface, but is not limited thereto.

In an embodiment, a groove H may be formed in the bottom surface of the cavity C. The groove H may be formed in plural. For example, the groove H may include the first groove H1 and the second groove H2, but is not limited thereto.

An electrode 210 having an upper surface exposed by the groove H may be formed. The electrode 210 may include a first electrode 211 and a second electrode 212, but is not limited thereto.

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

The extension parts 211b and 212a of the electrode 210 may overlap the bonding pad 120 vertically.

In an embodiment, upper surfaces of the extension parts 211b and 212a of the electrode 210 may be lower than the bottom surface of the cavity C so that the bonding pad 120 may be firmly fixed in the groove H.

The first electrode 211 and the second electrode 212 may be electrically separated from each other and 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 be formed through the package body 205. The first electrode 211 and the second electrode 212 may be formed through the package body 205 with a vertical or inclined.

The first electrode 211 and the second electrode 212 may be formed of a metal material having excellent electrical conductivity and strong corrosion resistance, such as Cu, Al, Cr, Pt, Ni, Ti, Au, or W, but It does not limit about.

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

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

In the embodiment, by using a conductive paste (not shown) inside the groove H, the electrode 210 and the light emitting device may be physically and electrically bonded through a firing process to increase contact force, conductivity, and heat dissipation efficiency. It is not limited.

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

Next, as shown in FIG. 4, the light emitting device 100 is mounted on the package body 205.

In this case, the bonding pad 120 of the light emitting device in the embodiment may be disposed in the groove (H).

In addition, 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.

Accordingly, the embodiment is provided with a groove in the package body of the area corresponding to the bonding pad of the light emitting device to bond the bonding pad to the inside of the package body groove to significantly widen the contact area between the bonding pad and the package body to maximize the heat dissipation efficiency You can.

In addition, according to the embodiment, by bonding the bonding pad to the inside of the package body groove, the bonding pad and the package body may be contacted with each other, and the groove inner wall may support the bonding pad, thereby greatly improving the contact force of the light emitting device, thereby increasing reliability. .

In an embodiment, the bonding pad 120 may be in contact with an inner side surface of the groove H. Accordingly, not only the bottom surface of the bonding pad 120 but also the side surface contact the package body 205 so that the groove sidewall of the package body supports the bonding pad, thereby greatly improving the contact force of the light emitting device, thereby increasing reliability. In addition, it is possible to maximize the heat dissipation efficiency by significantly widening the contact area between the bonding pad and the package body.

5 is a cross-sectional view of the 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 the third electrode 231 and the fourth electrode 232 may be formed of the package body 205. It may have a form penetrating the side surface and surrounding the bottom of the package body 205, but is not limited thereto.

In the second embodiment, the bonding pad 120 may be in contact with the third electrode 231 and the fourth electrode 232, and the third electrode 231 and the fourth electrode 232 than the bottom surface of the bonding pad 120. Since the upper surface of the wider bonding force with the bonding pad 120 can be more firm.

The embodiment has a groove in the package body of a region corresponding to the bonding pad of the light emitting device to bond the bonding pad to the inside of the package body groove, thereby significantly increasing the area where the bonding pad and the package body come into contact with each other to maximize heat dissipation efficiency. have.

In addition, according to the embodiment, by bonding the bonding pad to the inside of the package body groove, the bonding pad and the package body may be contacted with each other, and the groove inner wall may support the bonding pad, thereby greatly improving the contact force of the light emitting device, thereby increasing reliability. .

In addition, according to the embodiment, when the bonding pad of the light emitting device has a thick thickness of 100 μm using the electroplating method, there is a higher heat dissipation efficiency and higher adhesiveness than the conventional structure.

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

As shown in FIG. 6, the lighting system according to the embodiment may include a cover 2100, a light source module 2200, a heat sink 2400, a power supply 2600, an inner case 2700, and a socket 2800. have. In addition, the lighting apparatus according to the embodiment may further include any one or more of the member 2300 and the holder 2500. The light source module 2200 may include a light emitting device 100 or a light emitting device package 200 according to the present invention.

For example, the cover 2100 may have a bulb or hemisphere shape, and may be provided in a hollow shape and a part of which 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 the light provided from the light source module 2200. The cover 2100 may be a kind of optical member. The cover 2100 may be combined with the radiator 2400. The cover 2100 may have a coupling part coupled to the heat sink 2400.

An inner surface of the cover 2100 may be coated with a milky paint. The milky paint may include a diffuser that diffuses light. The surface roughness of the inner surface of the cover 2100 may be greater than the surface roughness of the outer surface of the cover 2100. This is for the light from the light source module 2200 to be sufficiently scattered and diffused and emitted 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 or opaque so that the light source module 2200 is visible from the outside. The cover 2100 may be formed through blow molding.

The light source module 2200 may be disposed on one surface of the heat sink 2400. Therefore, heat from the light source module 2200 is conducted to the heat sink 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 an upper surface of the heat dissipator 2400 and has a plurality of light source parts 2210 and guide grooves 2310 into which the connector 2250 is inserted. The guide groove 2310 corresponds to the substrate and the connector 2250 of the light source unit 2210.

The surface of the member 2300 may be coated or coated with a light reflective material. For example, the surface of the member 2300 may be coated or coated with a white paint. The member 2300 is reflected on the inner surface of the cover 2100 to reflect the light returned to the light source module 2200 side again toward the cover 2100. Therefore, it is possible to improve the light efficiency of the lighting apparatus according to the embodiment.

The member 2300 may be made of, for example, an insulating material. The connection plate 2230 of the light source module 2200 may include an electrically conductive material. Therefore, electrical contact may be made between the radiator 2400 and the connection plate 2230. The member 2300 may be made of an insulating material to block an electrical short between the connection plate 2230 and the radiator 2400. The radiator 2400 receives heat from the light source module 2200 and heat from the power supply unit 2600 to radiate heat.

The holder 2500 may block the accommodating groove 2719 of the insulating portion 2710 of the inner case 2700. Therefore, the power supply unit 2600 accommodated in the insulating unit 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 to provide the light source module 2200. The power supply unit 2600 is accommodated in the accommodating groove 2725 of the inner case 2700, and is sealed in the inner case 2700 by the holder 2500.

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

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

The extension part 2670 has a shape protruding outward from the other side of the base 2650. The extension part 2670 is inserted into the connection part 2750 of the inner case 2700 and receives an electrical signal from the outside. For example, the extension part 2670 may be provided equal to or smaller than the width of the connection part 2750 of the inner case 2700. Each end of the "+ wire" and the "-wire" may be electrically connected to the extension 2670, and the other end of the "+ wire" and the "-wire" may be electrically connected to the socket 2800. .

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

Features, structures, effects, etc. described in the above embodiments are included in at least one embodiment, but are not necessarily limited to 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 interpreted that the contents related to such a combination and modification are included in the scope of the embodiments.

Although described above with reference to the embodiment, this is merely an example, not to limit the embodiment, those skilled in the art to which the embodiment belongs to various not illustrated above in the range without departing from the essential characteristics of the embodiment It will be appreciated that modifications and applications of the branches are possible. For example, each component specifically shown in the embodiment can be modified. And differences relating to these modifications and applications will have to be construed as being included in the scope of the embodiments set forth in the appended claims.

Cavity C, package body 205, groove H, bonding pad 120, light emitting device 100

Claims (11)

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.
At least a portion of the bonding pad of the light emitting device is located inside the groove. According to claim 1,
The package body has a predetermined cavity,
The bottom surface of the bonding pad is disposed lower than the cavity bottom surface. According to claim 1,
The light emitting device package to expose the electrode disposed on the bottom of the package body by the groove. The method of claim 3, wherein
The bonding pad
A light emitting device package electrically connected to the electrode in the groove. According to claim 1,
The bonding pad
A light emitting device package in contact with the inner side of the groove. According to claim 1,
The bonding pad
A light emitting device package having a height of 100 μm or more. The method of claim 3, wherein
The electrode
Light emitting device package having an extension in an upward direction from the bottom of the package body. The method of claim 7, wherein
The expansion portion of the electrode overlaps the bonding pad and the upper and lower light emitting device package. The method of claim 7, wherein
The upper surface of the extension of the electrode
The light emitting device package is disposed lower than the upper surface of the package body. According to claim 1,
The electrode electrically connected to the bonding pad penetrates the side surface of the package body and surrounds the bottom surface of the package body. According to claim 1,
The package body is
And a cavity formed by a wall portion surrounding an edge of the package body and a bottom surface of the wall portion and the package body.

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