KR20170081902A - Light emitting device package - Google Patents

Abstract

Embodiments include a common electrode pad; At least one first light emitting element disposed on the common electrode pad and having a first electrode in contact with the common electrode pad; At least one second light emitting element disposed on the common electrode pad and having a second electrode in contact with the common electrode pad; A first electrode pad connected to a second electrode of the first light emitting device; And a second electrode pad connected to the first electrode of the second light emitting device, wherein the first electrode pad and the second electrode pad face each other with the common electrode pad therebetween, The second electrode pad is disposed to surround the common electrode pad, and the first light emitting device and the second light emitting device are spaced apart by a distance of less than 50 micrometers.

Description

[0001] LIGHT EMITTING DEVICE PACKAGE [0002]

An embodiment relates to a light emitting device package.

GaN, and AlGaN are widely used for optoelectronics and electronic devices due to their advantages such as wide and easy bandgap energy.

Particularly, a light emitting device such as a light emitting diode or a laser diode using a semiconductor material of a 3-5 group or a 2-6 group compound semiconductor has been widely used in various fields such as red, green, blue and ultraviolet rays It can realize various colors, and it can realize efficient white light by using fluorescent material or color combination. It has low power consumption, semi-permanent lifetime, fast response speed, safety, and environment compared to conventional light sources such as fluorescent lamps and incandescent lamps Affinity.

Therefore, a transmission module of the optical communication means, a light emitting diode backlight replacing a cold cathode fluorescent lamp (CCFL) constituting a backlight of an LCD (Liquid Crystal Display) display device, a white light emitting element capable of replacing a fluorescent lamp or an incandescent lamp Diode lighting, automotive headlights, and traffic lights.

The light emitting device includes a light emitting structure including a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer formed on a substrate made of sapphire or the like. The first conductivity type semiconductor layer and the second conductivity type semiconductor layer One electrode and the second electrode are disposed. In the light emitting device, electrons injected through the first conductive type semiconductor layer and holes injected through the second conductive type semiconductor layer meet with each other to emit light having energy determined by the energy band inherent in the material of the active layer. The light emitted from the active layer may be different depending on the composition of the material forming the active layer, and may be blue light, ultraviolet (UV) light or deep ultraviolet (UV) light.

Such a light emitting device can be arranged in a backlight unit, a lighting device, or the like in the form of a package, and recently, its use as a light source of a mobile terminal is increasing.

Particularly, when used as a light source of a lighting apparatus, the emission of heat generated from the light emitting element is important, and when a plurality of light emitting elements are arranged in one light emitting element package, color deviations between the light emitting elements should not occur, ) Design is required and various design margins need to be reduced.

The embodiment aims to improve the heat dissipation characteristics of the light emitting device package in which a plurality of light emitting elements are disposed, and to eliminate color deviation.

Embodiments include a common electrode pad; At least one first light emitting element disposed on the common electrode pad and having a first electrode in contact with the common electrode pad; At least one second light emitting element disposed on the common electrode pad and having a second electrode in contact with the common electrode pad; A first electrode pad connected to a second electrode of the first light emitting device; And a second electrode pad connected to the first electrode of the second light emitting device, wherein the first electrode pad and the second electrode pad face each other with the common electrode pad therebetween, The second electrode pad is disposed to surround the common electrode pad, and the first light emitting device and the second light emitting device are spaced apart by a distance of less than 50 micrometers.

The first light emitting device and the second light emitting device may be connected in series.

The plurality of first light emitting devices and / or the plurality of second light emitting devices may be connected in parallel to each other.

The second electrode of the first light emitting device and the first electrode of the second light emitting device may be exposed upward.

At least one of the common electrode pad, the first electrode pad, and the second electrode pad may include a heat dissipation unit, a bonding unit, and a reflective unit.

A first electrode pad and a second electrode pad, respectively corresponding to the first electrode pad and the second electrode pad, the first electrode pad and the second electrode pad being disposed under the package body, The one electrode pad may be electrically connected to the first electrode pad and the second electrode pad, respectively.

And a heat dissipation pad disposed at a lower portion of the package body in correspondence with the common electrode pad, wherein the heat dissipation pad can be electrically separated from the common electrode pad.

 In the light emitting device package according to the embodiment, the first light emitting device and the second light emitting device are connected to each other on a common electrode pad in series, so that the first light emitting device and the second light emitting device are disposed close to each other, The color deviation can be reduced. In addition, both the vertical first light emitting element and the conductive support substrate of the second light emitting element are in contact with the common electrode pad, which may be advantageous for heat dissipation.

In addition, since the light emitting devices are disposed adjacent to each other in a single light emitting device package, the color difference between the center region and the edge region can be reduced.

1A is a cross-sectional view of one embodiment of a light emitting device package,
1B is a detailed view of the common electrode pad and the like of FIG. 1A,
Fig. 2 is a plan view of Fig. 1,
FIGS. 3A and 3B are views showing the structure of the light emitting devices of FIG. 1,
4 is a view showing a current flow of the light emitting devices of FIG.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG.

In the description of the embodiment according to the present invention, in the case of being described as being formed "on or under" of each element, the upper (upper) or lower (lower) or under are all such that two elements are in direct contact with each other or one or more other elements are indirectly formed between the two elements. Also, when expressed as "on or under", it may include not only an upward direction but also a downward direction with respect to one element.

FIG. 1A is a cross-sectional view of an embodiment of a light emitting device package, FIG. 1B is a detailed view of the common electrode pad and the like of FIG. 1A, and FIG. 2 is a plan view of FIG. 1 and a lens 180 is omitted.

The light emitting device package 100 according to the embodiment includes the common electrode pad 122, the first electrode pad 126a and the second electrode pad 126b spaced apart from each other on the body 110, The first light emitting device 200a and the second light emitting device 200b are disposed on the first electrode pad 122 and the first light emitting device 200a and the second light emitting device 200b are connected to the first electrode pad 126a The electrode 180 may be electrically connected to the two electrode pad 126b through the wire 160 and the lens 180 may be disposed around the light emitting devices 200a and 200b and the wire 160. [

The body 110 is made of an insulating material and acts to support the light emitting device package 100. For example, the body 110 may be a PPA resin or a ceramic material. In particular, the body 110 may be made of Al ₂ O ₃ Or AlN.

The common electrode pad 122, the first electrode pad 126a, and the second electrode pad 126b may be formed of a conductive material, for example, a lead frame.

The common electrode pad 122 may be disposed on the central region of the body 110 and two first and second light emitting devices 200a and 200b may be disposed on the common electrode pad 122 have. The first light emitting device 200a and the second light emitting device 200b may be fixed on the common electrode pad 122 through the conductive adhesive layer 170 and the conductive adhesive layer 170 may be formed of a conductive material such as gold (Au) and tin (Sn). The conductive adhesive layer 170 may be formed by melting a mixture of gold and tin in a ratio of 8 to 2 at a temperature of 300 to 330 degrees to form the first light emitting device 200a and the second light emitting device 200b, (122).

The first electrode pad 126a and the second electrode pad 126b may be arranged to face each other with the common electrode pad 122 interposed therebetween. For example, the first electrode pad 126a and the second electrode pad 126b 126b may be disposed to surround the common electrode pad 122. [ However, as shown in the peripheral region of the common electrode pad 122 of the first electrode pad 126a and the second electrode pad 126b, they may be electrically separated from each other.

The common electrode pad 122, the first electrode pad 126a and the second electrode pad 126b are provided on the upper part of the package body 110 and the common electrode pad 122, the first electrode pad 126a, The heat dissipation pad 122-1, the 1-1 electrode pad 126a-1 and the 2-1 electrode pad 126b-1 are formed on the lower part of the package body 110 in correspondence with the second electrode pad 126b Respectively.

The heat radiation pad 122-1 may be disposed at a lower portion of the central region of the package body 110 and may be narrower than the common electrode pad 122. [ The heat dissipation pad 122-1 can discharge heat from the common electrode pad 122 to the circuit board (not shown) in the lower direction through the package body 110 made of a material such as ceramic or the like, And can be separated from the electrode pad 122.

The electrode pad 126a-1 and the second-1 electrode pad 126b-1 may correspond to the first electrode pad 126a and the second electrode pad 126b and may be disposed below the package body 110 And may have the same width as the first electrode pad 126a and the second electrode pad 126b, but are not limited thereto.

The electrode pad 126a-1 and the second-1 electrode pad 126b-1 are electrically connected to the first electrode pad 126a and the second electrode pad 126b through a package body 110 made of a ceramic or the like. (Not shown) or the like through the first penetrating electrode 126a-2 and the second penetrating electrode 126b-2 through the first penetrating electrode 126a-2 and the second penetrating electrode 126b-2, And the second electrode pad 126b.

The first penetrating electrode 126a-2 and the second penetrating electrode 126b-2 may be made of a conductive material, for example, copper (Cu). The width w of the first penetrating electrode 126a-2 may be equal to the width of the second penetrating electrode 126b-2 and may be, for example, 60 micrometers to 100 micrometers, The first electrode pad 126a and the first electrode pad 126a-1 may not be electrically and stably connected to each other. If the width W is too large, May be too large.

1A and 1B, two first light emitting devices 200a are disposed in a left region of the common electrode pad 122. The first light emitting device 200a includes a first electrode connected to the common electrode pad 122, And the second electrode may be electrically connected to the first electrode pad 126a through the wire 160. [ Two second light emitting devices 200b are disposed on the right side of the common electrode pad 122. The second light emitting devices 200b are arranged such that the second electrode is in electrical contact with the common electrode pad 122 The first electrode may be electrically connected to the second electrode pad 126b through the wire 160. [

The structure of the common electrode pad 122 is shown in detail in FIG. 1B, and the first electrode pad 126a and the second electrode pad 126b may have the same configuration.

The common electrode pad 122 may include a first layer, a second layer, and a third layer from below, wherein the first layer contacts the package body, The layer may be bonded to the light emitting elements 20a and 200b. The first layer acts as a heat dissipation part and may be made of a material having excellent heat dissipation properties, for example, copper (Cu). The third layer can act as a reflective portion and can be made of a material having a high reflectance, for example, gold (Au). The second layer may serve as a bonding portion, and may have excellent adhesion with the first and third layers but may be made of a material such as nickel (Ni).

The first layer may have a first thickness t1 of 80 micrometers to 100 micrometers. If the first thickness t1 is less than 80 micrometers, the heat dissipation characteristics may deteriorate. If the first thickness t1 is greater than 100 micrometers, The entire thickness of the pad 122 may become too large.

The second layer may have a second thickness t2 of between 5 micrometers and 8 micrometers and if the second thickness t2 is less than 5 micrometers the adhesion properties may be degraded and less than 8 micrometers may suffice .

The third layer may have a third thickness t3 of 0.2 micrometer to 0.6 micrometer and the third thickness t3 may have a reflectivity lower than 0.2 micrometer and a material thickness of greater than 0.6 micrometer may increase can do.

The thickness t0 of the entire common electrode pad 122 may be equal to the sum of the first thickness to the third thickness t1 to t3.

The structure of the common electrode pad 122 includes a first electrode pad 126a and a second electrode pad 126b as well as a heat radiation pad 122-1 and a 1-1 electrode pad 126a- 2-1 electrode pad 126b-1, in which the first layer is disposed in the direction of the package body 110 and the third layer is disposed in the opposite direction, that is, in the lower direction of FIG.

FIG. 3A and FIG. 3B are diagrams showing the structure of the light emitting devices of FIG. 1, wherein the light emitting device may be a light emitting diode, and a vertical light emitting device is shown as an example.

The first light emitting device 200a of FIG. 3A includes a bonding layer 214, a reflective layer 213 and an ohmic layer 212 disposed on a support substrate 215, and a light emitting structure and a channel layer 219 may be disposed at a bottom edge of the light emitting structure.

The support substrate 215 may be at least one of copper (Cu), gold (Au), nickel (Ni), molybdenum (Mo), and copper-tungsten (Cu-W) The support substrate 215 may be a carrier wafer such as Si, Ge, GaAs, ZnO, SiC, SiGe, Ga ₂ O ₃ , GaN, or the like.

A bonding layer 350 may be disposed on the support substrate 215. The bonding layer 214 may bond the reflective layer 213 to the supporting substrate 215. The bonding layer 214 may be formed of, Au, Sn, Ni, Cr, Ga, In, Bi, Cu, Ag or Ta.

A reflective layer 213 may be formed on the bonding layer 214. The reflective layer 213 may be formed of a material having excellent reflective properties such as silver (Ag), nickel (Ni), aluminum (Al), rubidium (Rh), palladium (Pd), iridium (Ir), ruthenium IZO, IZO, IGZO, IGTO, IGZO, IGZO, IGZO, IGZO, IGZO, AZO, ATO, or the like can be used as a single layer or multiple layers. Also, the reflective layer 213 may be laminated with IZO / Ni, AZO / Ag, IZO / Ag / Ni, AZO / Ag / Ni,

An ohmic layer 212 is formed on the reflective layer 213. The ohmic layer 212 may be in ohmic contact with the lower surface of the light emitting structure and may be formed in a layer or a plurality of patterns.

The ohmic layer 212 may be made of a metal such as indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IAZO) , Indium gallium zinc oxide (IGZO), indium gallium tin oxide (IGTO), aluminum zinc oxide (AZO), antimony tin oxide (ATO), gallium zinc oxide (GZO), IrOx, RuOx, RuOx / Ni / IrOx / Au, and Ni / IrOx / Au / ITO.

The support substrate 215, the bonding layer 214, the reflective layer 213, and the reflective layer 212 can serve as a first electrode and can supply current to the light emitting structure.

A channel layer 219 may be disposed between the first electrode and the edge of the light emitting structure 211. The channel layer 219 may be disposed in the lower edge region of the light emitting structure and may be formed of a light transmitting material and may be formed of, for example, a metal oxide, a metal nitride, a transparent nitride, a transparent oxide, or a light-

For example, the channel layer 219 may be formed of indium tin oxide (ITO), indium zinc oxide (IZO), IZO nitride, IZTO (indium zinc oxide), indium aluminum zinc oxide (IAZO) zinc oxide), IGTO (indium gallium tin oxide), AZO (aluminum zinc oxide), ATO (antimony tin oxide), GZO (gallium zinc oxide), SiO 2, SiO x, SiO x N y, Si 3 N 4, Al ₂ O ₃ , TiO _2, and the like.

The light emitting structure 211 may be disposed on the ohmic layer 212. The light emitting structure 211 includes a first conductivity type semiconductor layer 211a, an active layer 211b, and a second conductivity type semiconductor layer 211c.

The first conductive semiconductor layer 211a may be formed of a compound semiconductor such as a Group III-V or a Group II-VI, and may be doped with a first conductive dopant. The first conductive semiconductor layer 211a may be a semiconductor material having a composition formula of Al _x In _y Ga _1-xy N (0? X? 1, 0? _Y? 1, 0? _X + y? 1), AlGaN, GaN , InAlGaN, AlGaAs, GaP, GaAs, GaAsP, and AlGaInP.

When the first conductive semiconductor layer 211a is an n-type semiconductor layer, the first conductive dopant may include n-type dopants such as Si, Ge, Sn, Se, and Te. The first conductive semiconductor layer 211a may be formed as a single layer or a multilayer, but the present invention is not limited thereto.

The active layer 211b is disposed between the first conductive semiconductor layer 211a and the second conductive semiconductor layer 211c and has a single well structure, a multiple well structure, a single quantum well structure, a multi quantum well (MQW) Well structure, a quantum dot structure, or a quantum wire structure.

The active layer 211b may be formed using a compound semiconductor material of a group III-V element, and may be formed of In _x Al _y Ga _{1 -x- y} N (0? X? 1, 0? _Y? (InGaAs) / AlGaAs / InGaAs / GaAs (InGaAs) / AlGaAs / InGaAs / InGaN / InGaN / InGaN / InGaN / InGaN / GaN ) / AlGaP, but the present invention is not limited thereto.

The well layer may be formed of a material having an energy band gap smaller than the energy band gap of the barrier layer.

The second conductive type semiconductor layer 211c may be formed of a semiconductor compound. The second conductive semiconductor layer 211c may be formed of a compound semiconductor such as a Group III-V or a Group II-VI, and may be doped with a second conductive dopant. The second conductive semiconductor layer 211c may be a semiconductor material having a composition formula of In _x Al _y Ga _{1 -xy} N (0? X? 1, 0? _Y? 1, 0? _X + y? 1) , GaNAlInN, AlGaAs, GaP, GaAs, GaAsP, and AlGaInP.

When the second conductive type semiconductor layer 211c is a p-type semiconductor layer, the second conductive type dopant may be a p-type dopant such as Mg, Zn, Ca, Sr, and Ba. The second conductive semiconductor layer 211c may be formed as a single layer or a multilayer, but is not limited thereto.

Although not shown, an electron blocking layer may be disposed between the active layer 211b and the second conductive semiconductor layer 211c. The electron blocking layer may have a superlattice structure. For example, the superlattice may include AlGaN doped with a second conductive dopant, and GaN having a different composition ratio of aluminum may be formed as a layer But a plurality of them may be alternately arranged, but the present invention is not limited thereto.

The surface of the second conductivity type semiconductor layer 211c may have a pattern of irregularities or the like to improve the light extraction efficiency and the second electrode 216 may be disposed on the surface of the second conductivity type semiconductor layer 211c The surface of the second conductivity type semiconductor layer 211c on which the second electrode 216 is disposed may be a pattern or a pattern along the surface of the second conductivity type semiconductor layer 211c. The second electrode 216 may be formed as a single layer or a multilayer structure including at least one of aluminum (Al), titanium (Ti), chromium (Cr), nickel (Ni), copper have.

A current blocking layer 218 may be disposed on the lower portion of the light emitting structure 211 in correspondence with the second electrode 216. The current blocking layer may be formed of an insulating material, A current supplied in the direction of the substrate 215 can be uniformly supplied to the entire region of the second conductive type semiconductor layer 211c. The current blocking layer 218 may be disposed in a region vertically overlapping the second electrode 216, but is not limited thereto.

A passivation layer 217 may be formed around the light emitting structure 211. The passivation layer 217 may be made of an insulating material and the insulating material may be made of a non-conductive oxide or nitride. As an example, the passivation layer 217 may include at least one of a silicon oxide (SiO ₂ ) layer, an oxynitride layer, and an aluminum oxide layer.

The second light emitting device 200b of FIG. 3b is similar to the light emitting device of FIG. 3a except that the first and second conductive semiconductor layers 211a and 211c are disposed in opposite directions to each other, And the lower structures 212 to 215 may serve as the second electrodes.

1, a phosphor film 150 is disposed on the first light emitting device 200a and the second light emitting device 200b, and a first wavelength region 200b emitted from the first light emitting device 200a and the second light emitting device 200b, The phosphor in the phosphor film 150 can be excited to emit light in the second wavelength region.

In FIG. 2, the two first light emitting devices 200a may be connected in parallel to each other, and a second electrode (not shown) may be connected to the first electrode pad 126a through the wire 160. The two second light emitting devices 200b may be connected in parallel to each other and a first electrode (not shown) may be connected to the second electrode pad 126b through the wire 160. [

That is, although not shown in FIGS. 1 and 2, the second electrode of the first light emitting device 200a and the first electrode of the second light emitting device 200b may be exposed upward.

In this embodiment, the first electrode pad 126a may be connected to the (+) electrode and the second electrode pad 126b may be connected to the (-) electrode. Accordingly, the first light emitting device 200a and the second light emitting device 200b may be connected in series to each other to have a current flow as shown in FIG. That is, two of the first light emitting devices 200a are connected in parallel to each other, the second light emitting devices 200b are connected to each other in parallel, and the first light emitting device 200a and the second light emitting device 200b are connected in series .

The above structure can electrically connect the different electrodes of the first and second light emitting devices 200a and 200b to one common electrode pad 122. [ If the first light emitting device 200a and the second light emitting device 200b are arranged with the same polarity, the first light emitting device 200a and the second light emitting device 200b are both disposed on the common electrode pad 122 When placed, they are connected in parallel, not in series.

Therefore, in the embodiment, the first light emitting device 200a and the second light emitting device 200b having different polarities can be arranged in series on one common electrode pad 122. [

In FIG. 1, the first light emitting device 200a and the second light emitting device 200b may be spaced apart by a third spacing distance d3, while the third spacing distance d3 may be less than 50 micrometers. If the first light emitting device 200a and the second light emitting device 200b are connected in parallel, the electrode pads where the first light emitting device 200a and the second light emitting device 200b are disposed should be spaced apart from each other, Each electrode pad may be spaced more than 100 micrometers in consideration of process margin and the like.

Therefore, in the light emitting device package according to the embodiment, the first light emitting device 200a and the second light emitting device 200b are connected to each other in series on one common electrode pad 122, so that the first light emitting device 200a And the second light emitting device 200b are disposed close to each other so that the color deviation in the light emitting device package can be reduced. In addition, both the vertical first light emitting device 200a and the conductive supporting substrate of the second light emitting device 200b may be in contact with the common electrode pad 122, which may be advantageous for heat dissipation.

The common electrode pad 122 may be spaced apart from the first electrode pad 126a and the second electrode pad 126b by a first distance d1 and a second distance d2, d1 and the second distance d2 may each be 100 micro.

The above-described light emitting device package can be used as a light source of an illumination system, for example, in a light emitting device such as an image display device of an image display device and an illumination device.

When used as a backlight unit of an image display apparatus, it can be used as a backlight unit of an edge type or as a direct-type backlight unit, and can be used as a light source of a regulator or a belt type when used in a lighting apparatus. It is possible.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood 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:
122: common electrode pad 126a: first electrode pad
126b: second electrode pad 150: phosphor film
160: wire 200a: first light emitting element
200b: a second light emitting element

Claims (7)

A common electrode pad;
At least one first light emitting element disposed on the common electrode pad and having a first electrode in contact with the common electrode pad;
At least one second light emitting element disposed on the common electrode pad and having a second electrode in contact with the common electrode pad;
A first electrode pad connected to a second electrode of the first light emitting device; And
And a second electrode pad connected to the first electrode of the second light emitting device,
Wherein the first electrode pad and the second electrode pad face each other with the common electrode pad therebetween, the first electrode pad and the second electrode pad are disposed to surround the common electrode pad, And the two light emitting elements are spaced apart by a distance of less than 50 micrometers. The method according to claim 1,
Wherein the first light emitting device and the second light emitting device are connected in series. The method according to claim 1,
Wherein the plurality of first light emitting devices and / or the plurality of second light emitting devices are connected in parallel to each other. The method according to claim 1,
And a second electrode of the first light emitting device and a first electrode of the second light emitting device are exposed upward. The method according to claim 1,
Wherein at least one of the common electrode pad, the first electrode pad, and the second electrode pad includes a heat dissipation portion, a bonding portion, and a reflective portion. The method according to claim 1,
A first electrode pad and a second electrode pad, respectively corresponding to the first electrode pad and the second electrode pad, the first electrode pad and the second electrode pad being disposed under the package body, -1 electrode pads are electrically connected to the first electrode pads and the second electrode pads, respectively. The method according to claim 1,
And a heat dissipation pad disposed at a lower portion of the package body corresponding to the common electrode pad, wherein the heat dissipation pad is electrically separated from the common electrode pad.

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