KR20120087034A - Light emitting device and light emitting device package - Google Patents

Abstract

PURPOSE: A light emitting device and a light emitting device package are provided to reduce an operation voltage by arranging two or more pad parts in which a wire is bonded at a predetermined location on an electrode. CONSTITUTION: A junction layer(170) is formed on a support substrate(180). An ohmic layer(150) is formed on the junction layer. A light emitting structure layer(135) generating light is formed on the ohmic layer. The light emitting structure layer comprises a first conductivity type semiconductor layer(110), an active layer(120), and a second conductivity type semiconductor layer(130). A current blocking layer(145) is formed in an inner side between the second conductivity type semiconductor layer and the ohmic layer.

Description

LIGHT EMITTING DEVICE AND LIGHT EMITTING DEVICE PACKAGE}

Embodiments relate to a light emitting device and a light emitting device package.

Light emitting diodes (LEDs) are a type of semiconductor device that converts electrical energy into light. Light emitting diodes have the advantages of low power consumption, semi-permanent life, fast response speed, safety and environmental friendliness compared to conventional light sources such as fluorescent and incandescent lamps.

Accordingly, many researches are being conducted to replace existing light sources with light emitting diodes, and the use of light emitting devices as light sources for lighting devices such as lamps, liquid crystal displays, electronic signs, and street lamps that are used indoors and outdoors is increasing. to be.

The embodiment provides a light emitting device and a light emitting device package having a new structure.

In addition, the embodiment provides a light emitting device and a light emitting device package for reducing the operating voltage.

In addition, the embodiment provides a light emitting device and a light emitting device package for improving the operating voltage according to the position of the electrode pad portion to which the wire bonding is made.

Embodiments include a support substrate; A light emitting structure layer including a first conductive semiconductor layer, a second conductive semiconductor layer, and an active layer between the first conductive semiconductor layer and the second conductive semiconductor layer on the support substrate; A first pad portion and a second pad portion disposed closer to the outermost portion from a center region of the upper surface of the light emitting structure layer, and an electrode portion extending from at least one of the first pad portion and the second pad portion, The first pad portion is disposed on a first area closer to the first edge than the center area of the upper surface of the light emitting structure layer, and the second pad part is disposed in a first direction and the first direction from a second edge opposite to the first edge. A light emitting device is disposed on a second region spaced apart in at least one of a second direction perpendicular to the direction.

In addition, an embodiment includes a support substrate; A light emitting structure layer including a first conductive semiconductor layer, a second conductive semiconductor layer, and an active layer between the first conductive semiconductor layer and the second conductive semiconductor layer on the support substrate; A first pad part and a second pad part disposed closer to the outermost part from a center area of the upper surface of the light emitting structure layer, and an external electrode extending from at least one of the first pad part and the second pad part; And the first pad portion is disposed on a first region closer to the outermost portion than the center region of the upper surface of the light emitting structure layer, and the second pad portion is disposed along the first side surface of the upper surface of the light emitting structure layer from the first region. Provided is a light emitting device in which an extended first line segment and a second line segment connecting the first region and the opposite side of the first region are disposed on a second region spaced at an angle of at least 10 degrees.

In addition, the embodiment is a package body; A first electrode layer and a second electrode layer provided on the package body; And a light emitting device electrically connected to the first electrode layer and the second electrode layer, wherein the light emitting device comprises: a support substrate; A light emitting structure layer including a first conductive semiconductor layer, a second conductive semiconductor layer, and an active layer between the first conductive semiconductor layer and the second conductive semiconductor layer on the support substrate; A first pad portion and a second pad portion disposed closer to the outermost portion from a center region of the upper surface of the light emitting structure layer, and an electrode portion extending from at least one of the first pad portion and the second pad portion, The first pad portion is disposed on a first area closer to the first edge than the center area of the upper surface of the light emitting structure layer, and the second pad part is disposed in a first direction and the first direction from a second edge opposite to the first edge. A light emitting device package is disposed on a second region spaced apart in at least one of a second direction perpendicular to the direction.

In addition, the embodiment is a package body; A first electrode layer and a second electrode layer provided on the package body; And a light emitting device electrically connected to the first electrode layer and the second electrode layer, wherein the light emitting device comprises: a support substrate; A light emitting structure layer including a first conductive semiconductor layer, a second conductive semiconductor layer, and an active layer between the first conductive semiconductor layer and the second conductive semiconductor layer on the support substrate; A first pad part and a second pad part disposed closer to the outermost part from a center area of the upper surface of the light emitting structure layer, and an external electrode extending from at least one of the first pad part and the second pad part; And the first pad portion is disposed on a first region closer to the outermost portion than the center region of the upper surface of the light emitting structure layer, and the second pad portion is disposed along the first side surface of the upper surface of the light emitting structure layer from the first region. According to an embodiment, there is provided a light emitting device package, wherein an extended first line segment and a second line segment connecting the first region and the opposite side of the first region are disposed on a second region spaced at an angle of at least 10 degrees.

According to an embodiment, the operating voltage may be reduced by arranging at least two pad portions in which wire bonding is performed at predetermined positions on the electrodes.

Meanwhile, various other effects will be directly or implicitly disclosed in the detailed description according to the embodiment of the present invention to be described later.

1 is a cross-sectional view of a light emitting device according to an embodiment;
2 is a view showing an example of the shape on the plane of the electrode in the light emitting device according to the embodiment;
3A and 3B show another example of a shape on a plane of an electrode in a light emitting device according to an embodiment;
4 is a view showing another example of the shape on the plane of the electrode in the light emitting device according to the embodiment;
5 is a view showing the position of the pad unit for measuring the operating voltage in the light emitting device according to the embodiment;
6 is a view illustrating an operating voltage according to a position of a pad unit in a light emitting device according to an embodiment;
7 to 14 illustrate a method of manufacturing a light emitting device according to the embodiment;
15 is a cross-sectional view of a light emitting device package including a light emitting device according to the embodiment;
16 is a view illustrating a backlight unit including a light emitting device or a light emitting device package according to an embodiment;
17 is a view illustrating a lighting unit including a light emitting device or a light emitting device package according to an embodiment.

In the following description of the embodiments, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. The following terms are defined in consideration of the functions of the present invention, and may be changed according to the intentions or customs of the user, the operator, and the like. Therefore, the definition should be based on the contents throughout this specification.

In addition, in the description of the embodiments, each layer (film), region, pattern or structures may be "top" or "under" or "under" of the substrate, each layer (film), region, pad or pattern. The base material formed at ")" includes all those formed directly or through another layer. Criteria for the top / bottom or bottom / bottom of each layer will be described with reference to the drawings.

The thickness or the size of each layer (film), region, pattern or structure in the drawings may be modified for clarity and convenience of explanation, and thus does not entirely reflect the actual size.

Hereinafter, a light emitting device, a light emitting device manufacturing method, a light emitting device package, and an illumination system according to embodiments will be described with reference to the accompanying drawings.

1 is a cross-sectional view of a light emitting device according to an embodiment.

Referring to FIG. 1, the light emitting device 100 according to the present exemplary embodiment may include a support substrate 180, a light emitting structure layer 135 that generates light on the support substrate 180, and the light emitting structure layer 135. And an electrode 115 on the top. The light emitting structure layer 135 includes a first conductivity type semiconductor layer 110, an active layer 120, and a second conductivity type semiconductor layer 130, and the first conductivity type semiconductor layer 110 and the second conductivity type. Electrons and holes provided from the conductive semiconductor layer 130 may be recombined in the active layer 120 to generate light.

The bonding layer 170, the reflective layer 160, the ohmic layer 150, the channel layer 140, the current blocking layer 145, and the like may be disposed between the support substrate 180 and the light emitting structure layer 135. The passivation layer 190 may be formed on the side surface of the light emitting structure layer 135. This will be described in more detail as follows.

The support substrate 180 may support the light emitting structure layer 135 and provide power to the light emitting structure layer 135 together with the electrode 115. In addition, the support substrate 180 may be a conductive support substrate including at least one of Cu, Au, Ni, Mo, Cu-W, Si, Ge, GaAs, ZnO, or SiC. However, the embodiment is not limited thereto, and an insulating substrate may be used instead of the conductive support substrate, and a separate electrode may be formed.

The support substrate 180 may have a thickness of 30 μm to 500 μm. However, the embodiment is not limited thereto, and it will be apparent to those skilled in the art that the embodiment may vary depending on the design of the light emitting device 100.

A bonding layer 170 may be formed on the support substrate 180. The bonding layer 170 may be formed under the reflective layer 160 and the channel layer 140 as a bonding layer or a seed layer. An outer side surface of the bonding layer 170 is exposed and contacts the reflective layer 160, the end of the ohmic layer 150, and the channel layer 140, and thus the reflective layer 160, the ohmic layer 150, and the channel layer 140. It can strengthen the adhesion between).

The bonding layer 170 may include a barrier metal or a bonding metal. For example, the bonding layer 170 is Cu, Ni, Ag, Mo, Al, Au, Nb, W, Ti, Cr, Ta, Al, Pd, Pt, Si, Al-Si, Ag-Cd, Au -Sb, Al-Zn, Al-Mg, Al-Ge, Pd-Pb, Ag-Sb, Au-In, Al-Cu- Si, Ag-Cd-Cu, Cu-Sb, Cd-Cu, Al-Si -Cu, Ag-Cu, Ag-Zn, Ag-Cu-Zn, Ag-Cd-Cu-Zn, Au-Si, Au-Ge, Au-Ni, Au-Cu, Au-Ag-Cu, Cu-Cu2O Or Cu-Zn, Cu-P, Ni-P, Ni-Mn-Pd, Ni-P, or Pd-Ni.

The reflective layer 160 may be formed on the bonding layer 170. The reflective layer 160 may be generated by the light emitting structure layer 135 to reflect the light toward the reflective layer 160, thereby improving the luminous efficiency of the light emitting device 100.

Meanwhile, the reflective layer 160 may include at least one of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, Hf, or an alloy thereof. In addition, the reflective layer 160 may include the above-described metal or alloy, indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IZO), and indium gallium tin (IGTO). oxide), IGZO (indium gallium zinc oxide), AZO (aluminum zinc oxide), ATO (antimony tin oxide) can be formed in a multi-layer using a transmissive conductive material. For example, the reflective layer 160 may include a stacked structure of IZO / Ni, AZO / Ag, IZO / Ag / Ni, AZO / Ag / Ni, Ag / Cu, Ag / Pd / Cu, and the like.

An ohmic layer 150 may be formed on the reflective layer 160. The ohmic layer 150 is in ohmic contact with the second conductive semiconductor layer 130 so that power can be smoothly supplied to the light emitting structure layer 135. The ohmic layer 150 may include ITO, IZO, IZTO, IAZO, IGZO, IGTO, AZO, ATO, GZO (gallium zinc oxide), IrO _x , RuO _x , RuO _x / ITO, Ni, Ag, Pt, Ni / IrO _x / Au, or can be implemented as a single layer or multi-layer using at least one of _{Ni / IrO x / Au / ITO} .

 As described above, in the present exemplary embodiment, the upper surface of the reflective layer 160 is in contact with the ohmic layer 150, but the reflective layer 160 is in contact with the channel layer 140 or the light emitting structure layer 135. It would also be possible.

A current blocking layer 145 may be formed inside the ohmic layer 150 and the second conductive semiconductor layer 130. The current blocking layer 145 may include at least one of ZnO, SiO ₂ , SiON, Si ₃ N ₄ , Al ₂ O ₃ , TiO ₂ , Ti, Al, Cr.

An upper surface of the current blocking layer 145 may contact the second conductive semiconductor layer 130, and a lower surface and a side surface of the current blocking layer 145 may contact the ohmic layer 150.

The current blocking layer 145 may be formed such that at least a portion of the current blocking layer 145 overlaps with the electrode 115 in a vertical direction, thereby alleviating a phenomenon in which current is concentrated at the shortest distance between the electrode 115 and the supporting substrate 180. The luminous efficiency of the light emitting device 100 can be improved.

Meanwhile, a channel layer 140 may be formed outside the junction layer 170 and the second conductivity-type semiconductor layer 130. That is, the channel layer 140 may be formed in the circumferential region between the light emitting structure layer 135 and the bonding layer 170, thereby forming a ring shape, a loop shape, a frame shape, or the like.

The channel layer 140 may be formed of an electrically insulating material, a material having a lower electrical conductivity than the reflective layer 160 or the bonding layer 170, or a material forming a Schottky contact with the second conductive semiconductor layer 130. Can be formed. For example, the channel layer 140 may include ITO, IZO, IZTO, IAZO, IGZO, IGTO, AZO, ATO, ZnO, SiO ₂ , SiO _x , SiO _x N _y , Si ₃ N ₄ , Al ₂ O ₃ , TiO _x , TiO ₂ , Ti, Al, or Cr.

The second conductive semiconductor layer 130 and the passivation layer 190 are in contact with the upper surface of the channel layer 140, and the ohmic layer 150 and the bonding layer 170 are disposed on the lower surface and the side surface of the channel layer 140. You can contact this.

In the present exemplary embodiment, the ohmic layer 150 contacts the bottom and side surfaces of the channel layer 140, but is not limited thereto. Therefore, the ohmic layer 150 and the channel layer 140 may be spaced apart from each other, or the ohmic layer 150 may contact only the side surface of the channel layer 140. In addition, the channel layer 140 may be formed between the reflective layer 160 and the ohmic layer 150.

In addition, a portion of the channel layer 140 may overlap the light emitting structure layer 135 in the vertical direction. The channel layer 140 may increase the distance at the side surface between the bonding layer 170 and the active layer 120 to reduce the possibility of electrical short circuit between the bonding layer 170 and the active layer 120. In addition, the channel layer 140 may also prevent moisture or the like from penetrating into the gap between the light emitting structure layer 135 and the support substrate 180.

In addition, the channel layer 140 may prevent an electrical short circuit from occurring in the chip separation process. In more detail, when the isolation etching is performed to separate the light emitting structure layer 135 into the unit chip region, the debris generated in the bonding layer 170 is the second conductive semiconductor layer 130. And an electrical short may occur between the active layer 120 or between the active layer 120 and the first conductive semiconductor layer 110, and the channel layer 140 prevents the electrical short. Accordingly, the channel layer 140 may be formed of a material that does not break or cause fragmentation during isolation etching, or an insulating material that does not cause an electrical short even when a very small portion or a small amount of fragmentation occurs.

In addition, the light emitting structure layer 135 may be formed on the ohmic layer 150 and the channel layer 140. Side surfaces of the light emitting structure layer 135 may have an inclination by an isolation etching that divides a plurality of chips into unit chip regions.

The light emitting structure layer 135 may include a compound semiconductor layer of a plurality of group III-V elements, and may be disposed between the first conductive semiconductor layer 110 and the second conductive semiconductor layer 130 and therebetween. The active layer 120 may be included. In this case, the second conductive semiconductor layer 130 is positioned on the ohmic layer 150 and the channel layer 140, and the active layer 120 is positioned on the second conductive semiconductor layer 130. The conductive semiconductor layer 110 may be located on the active layer 120.

In addition, a first conductivity type InGaN / GaN superlattice structure or an InGaN / InGaN superlattice structure (not shown) may be formed between the first conductivity type semiconductor layer 110 and the active layer 120. In addition, a second conductive AlGaN layer (not shown) may be formed between the second conductive semiconductor layer 130 and the active layer 120.

The first conductivity type semiconductor layer 110 may include a compound semiconductor of a group III-V element doped with a first conductivity type dopant. For example, the first conductivity-type semiconductor layer 110 may include an n-type semiconductor layer. The n-type semiconductor layer is doped with n-type dopants to a semiconductor material having a compositional formula of _{In x Al y Ga 1 -x- y} N (0≤x≤1, 0≤y≤1, 0≤x + y≤1) Can be formed. For example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP, AlGaInP, etc. may be formed by including n-type dopants such as Si, Ge, Sn, Se, Te, and the like. The first conductivity type semiconductor layer 110 may be formed as a single layer or a multilayer, but is not limited thereto.

The active layer 120 may be formed of any one of a single quantum well structure, a multi quantum well structure (MQW), a quantum dot structure, or a quantum line structure, but is not limited thereto.

The active layer 120 may be formed of a semiconductor material having a compositional formula of _{In x Al y Ga 1 -x- y} N (0≤x≤1, 0≤y≤1, 0≤x + y≤1). When the active layer 120 has a multi-quantum well structure, the active layer 120 may be formed by stacking a plurality of well layers and a plurality of barrier layers. For example, the active layer 120 may be formed by alternately stacking a well layer including InGaN and a barrier layer including GaN.

A clad layer (not shown) doped with an n-type or p-type dopant may be formed on and / or under the active layer 120, and the clad layer may include an AlGaN layer or an InAlGaN layer. The band gap of the barrier layer may be larger than the band gap of the well layer, and the band gap of the clad layer may be larger than the band gap of the active layer.

The second conductivity type semiconductor layer 130 may include a compound semiconductor of a group III-V element doped with a second conductivity type dopant. For example, the second conductivity-type semiconductor layer 130 may include a p-type semiconductor layer. The p-type semiconductor layer is a p-type dopant doped in a semiconductor material having a composition formula of In _x Al _y Ga _{1 -x- y} N (0≤x≤1, 0≤y≤1, 0≤x + y≤1) Can be formed. For example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP, AlGaInP, etc. may be formed by including p-type dopants such as Mg, Zn, Ca, Sr, Br and the like. The second conductivity type semiconductor layer 130 may be formed as a single layer or a multilayer, but is not limited thereto.

In the present exemplary embodiment, the first conductive semiconductor layer 110 includes an n-type semiconductor layer, and the second conductive semiconductor layer 130 includes a p-type semiconductor layer, but the present invention is not limited thereto. Do not. That is, the first conductivity type semiconductor layer 110 may include a p-type semiconductor layer, and the second conductivity type semiconductor layer 130 may include an n-type semiconductor layer. In addition, another n-type or p-type semiconductor layer (not shown) may be formed under the second conductive semiconductor layer 130. Accordingly, the light emitting structure layer 135 may have at least one of np, pn, npn, and pnp junction structures.

In addition, the doping concentrations of the dopants in the first conductive semiconductor layer 110 and the second conductive semiconductor layer 130 may be uniform or non-uniform. That is, the structure of the light emitting structure layer 135 may be variously modified, but is not limited thereto.

The light extraction structure 112 may be formed on an upper surface of the light emitting structure layer 135. The light extraction structure 112 may improve the light extraction efficiency of the light emitting device 100 by minimizing the amount of light totally reflected from the surface. The light extraction structure 112 may have a random shape and arrangement, or may be formed to have a regular shape and arrangement. In this embodiment, a roughness pattern may be formed on an upper surface of the first conductivity type semiconductor layer 110 to increase light extraction efficiency.

The light emitting structure layer 135, and more specifically, the electrode 115 is formed on the upper surface of the first conductivity type semiconductor layer 110. The electrode 115 may be branched in a predetermined pattern shape, but is not limited thereto.

In addition, the electrode 115 has at least two pad portions (not shown) and at least one electrode portion 115a, 115b connected to the pad portion (not shown) may have the same or different stacked structure. But it is not limited thereto. Here, the pad part (not shown) means a portion where wire bonding is made on the electrode 115.

In the present embodiment, the electrode 115 includes a pad part (not shown), an external electrode 115a and an internal electrode 115b extending from the pad part. However, the at least one electrode portion may be formed of only the external electrode 115a. In addition, although the upper surface of the electrode 115 is configured as a plane, a roughness pattern may be formed on the upper surface of the electrode 115, but is not limited thereto.

The electrode 115 may be Au, Pd, Pt, Ru, Re, Mg, Zn, Hf, Ta, Rh, Ir, W, Ti, Ag, Cr, Mo, Nb, Al, Ni, Cu, WTi, or their It may comprise at least one of the alloys.

The passivation layer 190 may be formed on at least one side of the light emitting structure layer 135. The passivation layer 190 may be formed on an upper surface of the first conductivity type semiconductor layer 110 and an upper surface of the channel layer 140, but is not limited thereto.

The passivation layer 190 may be formed to electrically protect the light emitting structure layer 135. For example, the passivation layer 190 may be formed of SiO ₂ , SiO _x , SiO _x N _y , Si ₃ N ₄ , Al ₂ O ₃ . It may be formed, but is not limited thereto.

2 is a view showing an example of the shape on the plane of the electrode in the light emitting device according to the embodiment. Figure 1 shows a form in which the electrode is cut in the section II '.

1 and 2, the electrode 115 is formed on the first conductivity type semiconductor layer 110 and is disposed closer to the outermost part from the center area of the upper surface of the light emitting structure layer. And a second pad portion, and electrode portions 115a and 115b extending from at least one of the first pad portion and the second pad portion.

The electrode 115 may include a first pad part disposed on a first area closer to a first edge than a center area of an upper surface of the light emitting structure layer, and a first direction and the first direction from a second edge opposite to the first edge. And a second pad part disposed on the second area spaced apart in at least one of the second directions perpendicular to the one direction.

In addition, the electrode 115 extends along the upper periphery of the upper surface of the first conductivity-type semiconductor layer 110, the first portion of the external electrode 115a, and the external electrode 115a. It may include an internal electrode (115b) connecting the second portion of the. The inner electrode 115b may be disposed in an area surrounded by the outer electrode 115a. In the present exemplary embodiment, two internal electrodes 115b1 and 115b2 are described, but the present invention is not limited thereto.

As illustrated in FIG. 2, the external electrode 115a includes a first external electrode 115a1, a second external electrode 115a2, a third external electrode 115a3, and a fourth external electrode 115a4. The internal electrode 115b includes a first internal electrode 115b1 and a second internal electrode 115b2.

At least a portion of the external electrode 115a may be formed within 50 μm from an outermost portion of the upper surface of the first conductivity type semiconductor layer 110, and the external electrode 115a may be in contact with the passivation layer 180. It may be. For example, each of the first external electrode 115a1, the second external electrode 115a2, the third external electrode 115a3, and the fourth external electrode 115a4 may be at least partially disposed in the first conductive semiconductor layer 110. It may be disposed within 50㎛ from the outermost part of the upper surface).

The external electrode 115a may be disposed in a quadrangular shape having four sides and four vertices, and the first external electrode 115a1 and the second external electrode 115a2 extending in a first direction and the first direction. And a third external electrode 115a3 and a fourth external electrode 115a4 extending in a second direction perpendicular to the second direction.

The internal electrode 115b extends in the second direction to connect the first external electrode 115a1 and the second external electrode 115a2 extending in the first direction, and the second internal electrode 115b1. Electrode 115b2.

The pad part 115c includes a first pad part 115c1 and a second pad part 115c2. The first pad part 115c1 is disposed at a vertex portion where the second external electrode 115a2 and the third external electrode 115a3 meet, and the second pad part 115c2 is the first external electrode 115a1. ) And the fourth external electrode 115a4. Meanwhile, the first pad part 115c1 may be disposed at another vertex portion, and the second pad part 115c2 is positioned on an external electrode that is not adjacent to the first pad part 115c1.

When the position of the second pad part 115c2 is described in more detail, the second pad part 115c2 may have a line segment connecting itself with the first pad part 115c1 to form the second external electrode 115a2. A region that is greater than or equal to a predetermined angle as a reference and a line segment connecting the first pad part 115c1 to itself is positioned in an region that is greater than or equal to a predetermined angle with respect to the third external electrode 115a3. For example, the second pad portion 115c2 may have a line segment connecting itself with the first pad portion 115c1 to an area of 10 degrees or more to 80 degrees or less based on the second external electrode 115a2. Located.

More preferably, the second pad portion 115c2 is located in a region other than the portion where the first external electrode 115a1 and the fourth external electrode 115a4, which are opposite to the first pad portion 115c1, meet. Located.

On the other hand, if the position of the second pad portion is expressed by the distance ratio rather than the angle as follows.

As shown in FIG. 2, the first pad part 115c1 is positioned at a portion where the second external electrode 115a2 and the third external electrode 115a3 are in contact with each other, and the second pad part 115c2 is disposed at the contact point. It is assumed that the first external electrode 115a1 and the fourth external electrode 115a4 are positioned.

When the shape of the external electrode 115a is a square or rectangular shape having four sides and four vertices, the length of the first external electrode 115a1 and the length of the second external electrode 115a2 are A and the third external. It is assumed that the length of the electrode 115a3 and the length of the fourth external electrode 115a4 are B.

The length from the third external electrode 115a3 to the second pad portion 115c2 positioned on the first external electrode 115a1 is C, and the second external electrode 115a2 to the fourth external electrode. Assume that the length to the second pad portion 115c2 located on the 115a4 is D.

First, when the position (X) of the second pad portion 115c2 positioned on the first external electrode 115a1 is expressed as a distance ratio, Equation 1 below.

Here, A is the length of the first external electrode 115a1, B is the length of the third external electrode 115a3, C is the second pad located on the first external electrode 115a1 at the third external electrode 115a3. The length θ up to the portion 115c2 is an angle between the line segment connecting the first pad portion and the second pad portion and the third external electrode.

That is, the position X of the second pad part 115c2 is diagonally aligned from an area where a line segment connecting the first pad part 115c1 and itself is greater than or equal to a predetermined angle with respect to the third external electrode 115a3. Located in the area up to the side. More preferably, the line segment connecting the first pad portion 115c1 and itself is 10 degrees or more with respect to the third external electrode 115a3.

Next, when the position (Y) of the second pad portion 115c2 positioned on the fourth external electrode 115a4 is expressed as a distance ratio, Equation 2 below.

Here, A is the length of the second external electrode 115a2, B is the length of the fourth external electrode 115a3, D is the second pad located on the fourth external electrode 115a4 at the second external electrode 115a2. The length θ up to the portion 115c2 is an angle between the line segment connecting the first pad portion and the second pad portion and the second external electrode.

That is, the position Y of the second pad part 115c2 is diagonally aligned from an area where a line segment connecting the first pad part 115c1 and itself is greater than or equal to a predetermined angle with respect to the second external electrode 115a2. Located in the area up to the side. More preferably, the line segment connecting the first pad portion 115c1 and itself is 10 degrees or more with respect to the second external electrode 115a2.

3A and 3B illustrate another example of a shape on a plane of an electrode in the light emitting device according to the embodiment.

3A and 3B, the electrode 115 is formed on the first conductive semiconductor layer 110 and extends along the upper periphery of the first conductive semiconductor layer 110. And an internal electrode 115b connecting the first portion of the external electrode 115a and the second portion of the external electrode 115a. The inner electrode 115b may be disposed in an area surrounded by the outer electrode 115a.

The external electrode 115a includes a first external electrode 115a1, a second external electrode 115a2, a third external electrode 115a3, and a fourth external electrode 115a4. The internal electrode 115b may include a first internal electrode 115b1 and a second internal electrode 115b2.

At least a portion of the external electrode 115a may be formed within 50 μm from an outermost portion of the upper surface of the first conductivity type semiconductor layer 110, and the external electrode 115a may be in contact with the passivation layer 180. It may be.

The external electrode 115a may be disposed in a quadrangular shape having four sides and four vertices, and the first external electrode 115a1 and the second external electrode 115a2 extending in a first direction and the first direction. And a third external electrode 115a3 and a fourth external electrode 115a4 extending in a second direction perpendicular to the second direction.

The internal electrode 115b extends in the second direction to connect the first external electrode 115a1 and the second external electrode 115a2 extending in the first direction, and the second internal electrode 115b1. Electrode 115b2. In the exemplary embodiment, two internal electrodes 115b1 and 115b2 are described by way of example, but the present invention is not limited thereto.

The pad part 115c may include a first pad part 115c1 and a second pad part 115c2, and the first pad part 115c1 may include the second external electrode 115a2 and the third external part. The vertex portion where the electrode 115a3 meets is disposed, and the second pad portion 115c2 is disposed on the first external electrode 115a1 and the fourth external electrode 115a4.

Meanwhile, in the electrode illustrated in FIG. 3A, a portion where the second external electrode 115a2 and the fourth external electrode 115a4 meet and a portion where the first external electrode 115a1 and the third external electrode 115a3 meet each other are connected to each other. While forming the structure, the electrode illustrated in FIG. 3B has a portion where the second external electrode 115a2 and the fourth external electrode 115a4 meet and a portion where the first external electrode 115a1 and the third external electrode 115a3 meet. This forms an open structure.

4 is a view showing another example of the shape on the plane of the electrode in the light emitting device according to the embodiment. Hereinafter, the description of the same or very similar parts as described above will be omitted, and only different parts will be described in detail.

Referring to FIG. 4, the widths of the second external electrode 115a2 and the third external electrode 115a3 extending to the outside with respect to the first pad portion 115c1 of the electrode are far from the first pad portion 115c1. It may be formed in a thinner structure. In addition, the width of the fourth external electrode 115a4 that extends to the outside with respect to the second pad portion 115c2 of the electrode may be formed to be thinner as the width of the fourth external electrode 115a4 moves away from the second pad portion 115c2.

5 is a diagram illustrating a location of a pad unit for measuring an operating voltage in a light emitting device according to an exemplary embodiment. 6 is a diagram illustrating an operating voltage according to a position of a pad unit in the light emitting device according to the embodiment.

Referring to FIG. 5, the first pad part 115c1 is positioned at a portion where the second external electrode 115a2 and the third external electrode 115a3 are in contact with each other, and the second pad part 115c2 is a fourth external electrode ( Suppose it is located at point A, point B, point C or point D respectively on 115a4).

Herein, when the current of 350 mA is supplied to the light emitting device to measure the operating voltage according to the position of the second pad part 115c2, it is shown in Table 1 and FIG. 6.

 Position of the second pad part A point B point C point D point
Operating voltage (V)

3.38
3.34
3.32
3.33

Referring to Table 1 and FIG. 6, when the second pad part 115c2 is located at the A point (reference point), the operating voltage is the highest, and the second pad part 115c2 is located at the B, C, and D points. If it is located, it can be seen that the operating voltage is relatively low. Therefore, the operation voltage can be reduced by arranging the position of the second pad part 115c2 in a region of a predetermined angle or more from a region of a predetermined angle or less with respect to the second external electrode 115a2.

Hereinafter, a method of manufacturing a light emitting device according to the embodiment will be described in detail. However, the content overlapping with the above description will be omitted or briefly described.

7 to 14 are views illustrating a method of manufacturing a light emitting device according to the embodiment.

Referring to FIG. 7, the light emitting structure layer 135 is formed on the growth substrate 101.

The growth substrate 101 may be formed of, for example, at least one of sapphire (Al ₂ O ₃ ), SiC, GaAs, GaN, ZnO, Si, GaP, InP, Ge, but is not limited thereto. For example, the light emitting structure layer may be grown on the growth substrate 101, and the sapphire substrate may be used.

The light emitting structure layer 135 may be formed by sequentially growing the first conductive semiconductor layer 110, the active layer 120, and the second conductive semiconductor layer 130 on the growth substrate 101. .

The light emitting structure layer 135 may include, for example, Metal Organic Chemical Vapor Deposition (MOCVD), Chemical Vapor Deposition (CVD), Plasma-Enhanced Chemical Vapor Deposition (PECVD), Molecular Beam Epitaxy (MBE), Hydride Vapor Phase Epitaxy (HVPE), and the like may be formed using, but are not limited thereto.

Meanwhile, a buffer layer (not shown) and / or an undoped semiconductor layer (not shown) may be formed between the light emitting structure layer 135 and the growth substrate 101 to alleviate the lattice constant difference. The undoped semiconductor layer is a nitride layer which may not intentionally inject impurities of the first conductivity type, but may have a conductivity characteristic of the first conductivity type. For example, the undoped nitride layer is formed of an Undoped-GaN layer. May be A buffer layer may be formed between the undoped semiconductor layer and the growth substrate 101. In addition, the undoped semiconductor layer is not necessarily formed, and may not be formed.

Referring to FIG. 8, a channel layer 140 is formed on the light emitting structure layer 135 to correspond to a unit chip region.

The channel layer 140 may be formed on the second conductive semiconductor layer 130 using a mask pattern. The channel layer 140 may be formed using various deposition methods.

The channel layer 140 may be formed of an electrically insulating material, a material having a lower electrical conductivity than the reflective layer 160 or the bonding layer 170, or a material forming a Schottky contact with the second conductive semiconductor layer 130. Can be formed. For example, the channel layer 140 may include ITO, IZO, IZTO, IAZO, IGZO, IGTO, AZO, ATO, ZnO, SiO ₂ , SiO _x , SiO _x N _y , Si ₃ N ₄ , Al ₂ O ₃ , It may include at least one of TiO _x , TiO ₂ , Ti, Al or Cr.

9 and 10, an ohmic contact layer 150 is formed on the second conductive semiconductor layer 130 and the channel layer 140, and a reflective layer 160 is formed on the ohmic contact layer 150. ) Can be formed.

The ohmic contact layer 150 and the reflective layer 160 may be formed by, for example, any one of electron beam (E-beam) deposition, sputtering, and plasma enhanced chemical vapor deposition (PECVD). .

The area in which the ohmic contact layer 150 and the reflective layer 160 are formed may be variously selected, and various kinds of light emitting devices may be formed according to the area in which the ohmic contact layer 150 and / or the reflective layer 160 are formed. Can be made.

Referring to FIG. 11, the support substrate 180 is formed on the reflective layer 160 and the channel layer 140 via the bonding layer 170.

The bonding layer 170 is in contact with the reflective layer 160, the ends of the ohmic contact layer 150, and the protective layer 140, so that the reflective layer 160, the ohmic contact layer 150, and the channel layer ( 140) can enhance the adhesion between.

The support substrate 180 is attached on the bonding layer 170. Although the embodiment illustrates that the support substrate 180 is bonded by the bonding layer 170, the support substrate 180 may be formed by a plating method or a deposition method.

Referring to FIG. 12, the growth substrate 101 is removed from the light emitting structure layer 135. In FIG. 12, the light emitting device illustrated in FIG. 11 is shown upside down. In this case, the growth substrate 101 may be removed by a laser lift off method or a chemical lift off method.

Referring to FIG. 13, the light emitting structure layer 135 is isolated by a plurality of light emitting structure layers 135 by an isolation etching according to a unit chip region.

For example, the isolation etching may be performed by a dry etching method such as inductively coupled plasma (ICP).

Referring to FIG. 14, a passivation layer 180 is formed on the channel layer 140 and the light emitting structure layer 135, and the passivation layer is formed so that the top surface of the first conductive semiconductor layer 110 is exposed. Selectively remove 180).

A roughness pattern 112 is formed on the top surface of the first conductive semiconductor layer 110 to improve light extraction efficiency, and an electrode 115 is formed on the roughness pattern 112. The roughness pattern 112 may be formed by a wet etching process or a dry etching process.

Thereafter, when the structure is separated into a unit chip region through a chip separation process, a plurality of light emitting devices may be manufactured.

The chip separation process may include, for example, a breaking process of separating a chip by applying a physical force using a blade, a laser scribing process of separating a chip by irradiating a laser to a chip boundary, and a wet etching or a dry etching process. It may include an etching process, but is not limited thereto.

15 is a cross-sectional view of a light emitting device package including a light emitting device according to the embodiment.

Referring to FIG. 15, the light emitting device package 1000 may include a package body 30, a first electrode 31 and a second electrode 32 installed on the package body 30, and the package body 30. The light emitting device 100 is installed to be electrically connected to the first electrode 31 and the second electrode 32, and a molding member 40 surrounding the light emitting device 100.

The package body 30 may include a silicon material, a synthetic resin material, or a metal material, and may have a cavity having an inclined side surface.

The first electrode 31 and the second electrode 32 are electrically separated from each other, and provide power to the light emitting device 100. In addition, the first electrode 31 and the second electrode 32 may increase the light efficiency by reflecting the light generated from the light emitting device 100, the heat generated from the light emitting device 100 to the outside It can also play a role.

The light emitting device 100 may be installed on the package body 30 or on the first electrode 31 or the second electrode 32.

The light emitting device 100 may be electrically connected to the first electrode 31 and the second electrode 32 by any one of a wire method, a flip chip method, and a die bonding method. In the present embodiment, it is illustrated that the light emitting device 100 is electrically connected to the first electrode 31 and the wire 50 and is directly connected to the second electrode 32.

The molding member 40 may surround the light emitting device 100 to protect the light emitting device 100. In addition, the molding member 40 may include a phosphor to change the wavelength of light emitted from the light emitting device 100.

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

16 is a view illustrating a backlight unit including a light emitting device or a light emitting device package according to an embodiment. However, the backlight unit 1100 of FIG. 16 is an example of a lighting system, but is not limited thereto.

Referring to FIG. 16, the backlight unit 1100 may include a bottom frame 1140, an optical guide member 1120 disposed in the bottom frame 1140, and at least one side or a bottom surface of the optical guide member 1120. It may include a light emitting module 1110 disposed in. In addition, a reflective sheet 1130 may be disposed under the light guide member 1120.

The bottom frame 1140 may be formed in a box shape having an upper surface open to accommodate the light guide member 1120, the light emitting module 1110, and the reflective sheet 1130. Or it may be formed of a resin material but is not limited thereto.

The light emitting module 1110 may include a substrate 700 and a plurality of light emitting device packages 600 mounted on the substrate 700. The plurality of light emitting device packages 600 may provide light to the light guide member 1120. In the present embodiment, the light emitting module 1110 is illustrated that the light emitting device package 600 is installed on the substrate 700, it is also possible that the light emitting device 100 according to the embodiment is installed directly.

As shown, the light emitting module 1110 may be disposed on at least one of the inner surfaces of the bottom frame 1140, thereby providing light toward at least one side of the light guide member 1120. can do.

However, the light emitting module 1110 may be disposed under the bottom frame 1140 to provide light toward the bottom surface of the light guide member 1120, which is according to the design of the backlight unit 1100. Since various modifications are possible, the present invention is not limited thereto.

The light guide member 1120 may be disposed in the bottom frame 1140. The light guide member 1120 may guide the light provided from the light emitting module 1110 to a display panel by surface light source.

The light guide member 1120 may be a light guide panel (LGP). The light guide plate may be formed of one of an acrylic resin series such as polymethyl metaacrylate (PMMA), polyethylene terephthlate (PET), poly carbonate (PC), COC, and polyethylene naphthalate (PEN) resin.

The optical sheet 1150 may be disposed above the light guide member 1120.

The optical sheet 1150 may include at least one of a diffusion sheet, a light collecting sheet, a luminance rising sheet, and a fluorescent sheet. For example, the optical sheet 1150 may be formed by stacking the diffusion sheet, the light collecting sheet, the luminance increasing sheet, and the fluorescent sheet. In this case, the diffusion sheet 1150 may evenly diffuse the light emitted from the light emitting module 1110, and the diffused light may be focused onto a display panel (not shown) by the light collecting sheet. In this case, the light emitted from the light collecting sheet is randomly polarized light, and the luminance increasing sheet may increase the degree of polarization of the light emitted from the light collecting sheet. The light collecting sheet may be a horizontal or vertical prism sheet. In addition, the luminance increase sheet may be a roughness enhancement film. In addition, the fluorescent sheet may be a translucent plate or film containing a phosphor.

The reflective sheet 1130 may be disposed under the light guide member 1120. The reflective sheet 1130 may reflect light emitted through the bottom surface of the light guide member 1120 toward the exit surface of the light guide member 1120.

The reflective sheet 1130 may be formed of a resin material having good reflectance, that is, PET, PC, PVC resin, etc., but is not limited thereto.

17 is a view illustrating a lighting unit including a light emitting device or a light emitting device package according to an embodiment. However, the lighting unit 1200 of FIG. 17 is an example of a lighting system, but is not limited thereto.

Referring to FIG. 17, the lighting unit 1200 is installed in the case body 1210, the light emitting module 1230 installed in the case body 1210, and the case body 1210, and provides power from an external power source. It may include a receiving connection terminal 1220.

The case body 1210 is preferably formed of a material having good heat dissipation characteristics, for example, may be formed of a metal material or a resin material.

The light emitting module 1230 may include a substrate 700 and at least one light emitting device package 600 mounted on the substrate 700. In the present embodiment, the light emitting module 1230 is illustrated that the light emitting device package 600 is installed on the substrate 700, the light emitting device 100 according to the present embodiment may be installed directly.

The substrate 700 may be a circuit pattern printed on the insulator, and for example, a general printed circuit board (PCB), a metal core PCB, a flexible PCB, a ceramic PCB, and the like. It may include.

In addition, the substrate 700 may be formed of a material that reflects light efficiently, or may be formed of a color in which the surface is efficiently reflected by light, for example, white, silver, or the like.

The at least one light emitting device package 600 may be mounted on the substrate 700. Each of the light emitting device packages 600 may include at least one light emitting diode (LED). The light emitting diodes may include colored light emitting diodes emitting red, green, blue, or white colored light, and UV light emitting diodes emitting ultraviolet (UV) light.

The light emitting module 1230 may be arranged to have a combination of various light emitting diodes in order to obtain color and brightness. For example, the white light emitting diode, the red light emitting diode, and the green light emitting diode may be combined and disposed to secure high color rendering (CRI). In addition, a fluorescent sheet may be further disposed on a path of the light emitted from the light emitting module 1230, and the fluorescent sheet changes the wavelength of light emitted from the light emitting module 1230. For example, when the light emitted from the light emitting module 1230 has a blue wavelength band, the fluorescent sheet may include a yellow phosphor, and the light emitted from the light emitting module 1230 finally passes white light through the fluorescent sheet. Will appear.

The connection terminal 1220 may be electrically connected to the light emitting module 1230 to supply power. As shown in FIG. 14, the connection terminal 1220 is inserted into and coupled to an external power source in a socket manner, but is not limited thereto. For example, the connection terminal 1220 may be formed in a pin shape and inserted into an external power source, or may be connected to the external power source by a wire.

In the lighting system as described above, at least one of a light guide member, a diffusion sheet, a light collecting sheet, a luminance rising sheet, and a fluorescent sheet may be disposed on a propagation path of light emitted from the light emitting module to obtain a desired optical effect.

As described above, the illumination system may have excellent light efficiency and reliability by including a light emitting device or a light emitting device package which reduces the operating voltage and improves the light efficiency.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the claims below, but also by those equivalent to the claims.

Claims (11)

Support substrates;
A light emitting structure layer including a first conductive semiconductor layer, a second conductive semiconductor layer, and an active layer between the first conductive semiconductor layer and the second conductive semiconductor layer on the support substrate;
A first pad portion and a second pad portion disposed closer to the outermost portion from a center region of the upper surface of the light emitting structure layer, and an electrode portion extending from at least one of the first pad portion and the second pad portion,
The first pad part is disposed on a first area closer to a first edge than a center area of an upper surface of the light emitting structure layer.
The second pad part is disposed on a second area spaced apart from at least one of a first direction and a second direction orthogonal to the first direction from a second edge opposite the first edge. The method of claim 1, wherein the electrode unit,
Light emission includes a first external electrode and a second external electrode formed in the first direction, and a third external electrode and a fourth external electrode extending in the second direction to connect the first external electrode and the second external electrode. device. The method of claim 2, wherein the electrode unit,
And an inner electrode disposed in the outer electrode region and connecting the first portion and the second portion of the outer electrode. The method of claim 3, wherein
The width of at least a portion of the external electrode is formed larger than the width of the inner electrode. The method of claim 1,
The light emitting device of claim 1, wherein the width of an electrode portion extending outwardly from the first pad portion and the second pad portion becomes thinner from the first pad portion and the second pad portion. The method of claim 1,
And a portion of the electrode portion extending from the first pad portion and a portion of the electrode portion extending from the second pad portion are connected to each other. The method of claim 1,
The light emitting device having a structure in which a portion of the external electrode extending from the first pad portion and a portion of the external electrode extending from the second pad portion are opened to each other. Support substrates;
A light emitting structure layer including a first conductive semiconductor layer, a second conductive semiconductor layer, and an active layer between the first conductive semiconductor layer and the second conductive semiconductor layer on the support substrate;
A first pad part and a second pad part disposed closer to the outermost part from a center area of the upper surface of the light emitting structure layer, and an external electrode extending from at least one of the first pad part and the second pad part; ,
The first pad part is disposed on the first area closer to the outermost part than the center area of the upper surface of the light emitting structure layer,
The second pad part may have a first line segment extending from the first region along a first side surface of the upper surface of the light emitting structure layer, and a second line segment connecting the first region and the first region opposite to the first region may be at least 10 degrees. The light emitting device is disposed on the second region spaced apart. The method of claim 8, wherein the external electrode,
A first external electrode and a second external electrode formed in a first direction, and a third external electrode and a fourth external electrode extending in a second direction orthogonal to the first direction to connect the first external electrode and the second external electrode; Light emitting device comprising an electrode. The method of claim 9,
The first pad part is disposed at a point where the second external electrode formed in the first direction and the third external electrode formed in the second direction meet each other.
The second pad part is disposed on a first external electrode which is not adjacent to the first pad part, and is disposed in an area having a distance ratio (X) corresponding to the following equation.
[Mathematical Expression]

Where A is the length of the first external electrode, B is the length of the third external electrode, C is the length from the third external electrode to the second pad portion located on the first external electrode, and 10 ° is the first pad portion. And an angle between the line segment connecting the second pad portion and the third external electrode. The method of claim 9,
The first pad part is disposed at a point where the second external electrode formed in the first direction and the third external electrode formed in the second direction meet each other.
The second pad part is disposed on a fourth external electrode which is not adjacent to the first pad part, and is disposed in an area having a distance ratio (Y) corresponding to the following equation.
[Mathematical Expression]

Where A is the length of the second external electrode, B is the length of the fourth external electrode, D is the length from the second external electrode to the second pad portion 115c2 positioned on the fourth external electrode, and 10 ° is the length of the second external electrode. 1 The angle between the line segment connecting the pad portion and the second pad portion and the second external electrode.

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