KR101861222B1 - Light emitting diode having electrode extensions - Google Patents

Abstract

A light emitting diode having electrode extensions is disclosed. The light emitting diode includes a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, an active layer located between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer, a plurality The first electrode extension lines of the second conductivity type semiconductor layer, the first electrode pad electrically connected to the first electrode extension lines, the plurality of second electrode extension lines electrically connected to the second conductivity type semiconductor layer, And a second electrode pad. Furthermore, the plurality of second electrode extension lines include at least two second electrode extension lines positioned between neighboring first electrode extension lines of the plurality of first electrode extension lines. By arranging at least two second electrode extension lines between the first electrode extension lines, the interval between the first electrode extension lines can be relatively increased, so that reduction in the light emission area can be mitigated, thereby improving light output or light efficiency can do.

Description

[0001] LIGHT EMITTING DIODE HAVING ELECTRODE EXTENSIONS [0002]

The present invention relates to light emitting diodes, and more particularly to light emitting diodes having electrode extensions.

GaN-based LEDs are currently used in various applications such as color LED display devices, LED traffic signals, and white LEDs. In recent years, high efficiency white LEDs are expected to replace fluorescent lamps. In particular, the efficiency of white LEDs has reached a level similar to that of ordinary fluorescent lamps.

The gallium nitride series light emitting diode is generally formed by growing epitaxial layers on a substrate such as sapphire, and includes an n-type semiconductor layer, a p-type semiconductor layer, and an active layer interposed therebetween. On the other hand, an n-electrode pad is formed on the n-type semiconductor layer, and a p-electrode pad is formed on the p-type semiconductor layer. The light emitting diode is electrically connected to an external power source through the electrode pads. At this time, current flows from the p-electrode pad to the n-electrode pad through the semiconductor layers.

On the other hand, extensions extending from the electrode pads are used to facilitate current dispersion in the light emitting diode. For example, U.S. Patent No. 6,650,018 discloses a technique in which electrode contacts, that is, a plurality of extensions from electrode pads extend in opposite directions to enhance current dispersion. By using an extension extended from the electrode pad, the efficiency of the light emitting diode can be increased by dispersing the current.

FIG. 1 is a schematic plan view for explaining a light emitting diode according to the related art, and FIG. 2 is a sectional view taken along the cutting line A-A in FIG. Here, the light emitting diode has a size of approximately 1450 mu m x 1450 mu m.

1 and 2, the light emitting diode includes a substrate 21, a first conductive semiconductor layer 23, an active layer 25, a second conductive semiconductor layer 27, a transparent electrode layer 29, Electrode pads 33, p-electrode pads 35, n-electrode extensions 33a, and p-electrode extensions 35a.

A sapphire substrate is generally used as the substrate 21 and the first conductivity type semiconductor layer 23, the active layer 25 and the second conductivity type semiconductor layer 27 are formed on the substrate 21 by organic chemical vapor deposition May be a gallium nitride-based compound semiconductor layer grown by using GaN. Here, the first conductivity type semiconductor layer 23 is n-type and the second conductivity type semiconductor layer 27 is p-type.

The n-electrode pad 33 and the n-electrode extension portions 33a are formed on the exposed first conductivity type semiconductor layer 23 by etching the second conductivity type semiconductor layer 27 and the active layer 25 do. On the other hand, a transparent electrode layer 29 is formed on the second conductivity type semiconductor layer 27, and a p-electrode pad 35 and p-electrode extensions 35a are formed thereon. In addition, an insulating layer 31 may be formed to protect the light emitting diode.

The n-electrode extensions 33a and the p-electrode extensions 35a extend linearly and are alternately arranged. That is, one p-electrode extension line 35a is located between neighboring n-electrode extension lines 33a. As described above, the n-electrode extension lines 33a and the p-electrode extension lines 35a are alternately arranged to distribute the current over the entire area of the light emitting diode.

However, as apparent from Figs. 1 and 2, the n-electrode pad and the n-electrode extension are usually formed on the exposed n-type semiconductor layer by etching the p-type semiconductor layer and the active layer. Thus, by forming the n-electrode pad and the n-electrode extension, the light emitting area is reduced, resulting in a decrease in light output or light efficiency.

Furthermore, since the electrode pads and the electrode extensions are formed of a metal having a high light absorptivity such as Cr / Au, the light generated in the active layer is likely to be absorbed by the electrode pads and electrode extensions and lost.

Furthermore, even if the electrode extensions are adopted to disperse the current, the current is mainly concentrated in the region adjacent to the electrode extensions. Therefore, mainly light is emitted in the region immediately under the electrode extension portions or in the active layer region in the region adjacent to the electrode extension portions, and this light is absorbed and lost by the electrode extension portions, so that the light loss by the electrode extension portions is further increased do.

U.S. Patent No. 6,650,018

Another object of the present invention is to provide a light emitting diode capable of improving light output and / or luminous efficiency.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a light emitting diode capable of alleviating a decrease in light emitting area due to the formation of an electrode extension.

Another object of the present invention is to provide a light emitting diode capable of dispersing a current over a wide area of a light emitting diode by mitigating current concentration generated around electrode pads and electrode extension parts.

Another object of the present invention is to provide a light emitting diode capable of preventing light loss due to electrode pads and electrode extension parts.

A light emitting diode according to the present invention includes: a first conductive semiconductor layer; A second conductivity type semiconductor layer; An active layer disposed between the first conductive semiconductor layer and the second conductive semiconductor layer; A plurality of first electrode extension lines electrically connected to the first conductivity type semiconductor layer; A first electrode pad electrically connected to the first electrode extension lines; A plurality of second electrode extension lines electrically connected to the second conductivity type semiconductor layer; And a second electrode pad electrically connected to the second electrode extension lines. Furthermore, the plurality of second electrode extension lines may include at least two second electrode extension lines that are located between neighboring first electrode extension lines of the plurality of first electrode extension lines.

It is possible to relatively increase the interval between the first electrode extension lines by arranging at least two second electrode extension lines between neighboring first electrode extension lines so as to alleviate the reduction of the light emission area, The efficiency can be improved.

The at least two second electrode extension lines may extend along opposite first electrode extension lines to the opposite sides of the first electrode extension lines. Furthermore, the at least two second electrode extension lines may have second straight portions parallel to each other, and the adjacent first electrode extension lines may have first straight portions parallel to each other. The first rectilinear portions and the second rectilinear portions may be parallel to each other.

If n (n > = 2) second electrode extension lines are disposed between neighboring first electrode extension lines, the interval between the second straight line portions of the neighboring second electrode extension lines parallel to each other is Is preferably smaller than 1 / (n + 1) of the interval between the first rectilinear portions of the first electrode extension lines parallel to each other. Further, the interval between the second straight line portions of the neighboring second electrode extension lines is larger than 0, and in particular, the interval between the first straight line portions of the neighboring first electrode extension lines is 1 / (n + 2). For example, when two second electrode extension lines are disposed between neighboring first electrode extension lines, the interval between the second straight line portions parallel to each other of the two second electrode extension lines is shorter than the distance between the adjacent first electrode extension lines Is preferably smaller than 1/3 of the interval between the parallel first linear portions. Further, the interval between the second straight lines parallel to each other may be larger than 1/4 of the interval between the first straight lines parallel to each other. In addition, the interval between the second rectilinear portions may be in the range of 10 to 200 mu m.

The light emitting diode includes first auxiliary extension lines branched from the first electrode extension lines; And second auxiliary extension lines branched at the second electrode extension lines.

On the other hand, a transparent electrode layer may be interposed between the plurality of second electrode extension lines and the second conductive type semiconductor layer. The transparent electrode layer makes an ohmic contact with the second conductivity type semiconductor layer.

In addition, it is possible to prevent the current blocking layer from being injected from the second electrode extension lines into the second conductive type semiconductor layer in a region immediately below the second electrode extension lines. The current blocking layer may be positioned between the transparent electrode layer and the second conductive type semiconductor layer.

Meanwhile, the plurality of first electrode extension lines and the plurality of second electrode extension lines may have a metal laminated structure having the same structure. The metal laminated structure includes a contact layer, a reflective layer, a barrier layer, and a bonding layer. Further, the contact layer may be formed of a metal selected from nickel, chromium, and titanium, the reflective layer may be formed of aluminum, and the bonding layer may be formed of gold. In addition, the barrier layer may be a single layer or multiple layers and may be, for example, Ni, Ni / Ti, Ni / Ti / Ni / Ti, Cr / Pt or Ni / Pt.

According to the present invention, it is possible to provide a light emitting diode capable of reducing light emission area reduction due to the formation of the electrode extension portion, thereby improving light output and / or luminous efficiency. Further, it is possible to provide a light emitting diode capable of dispersing a current over a wide area of the light emitting diode by mitigating current concentration generated around the electrode pad and the electrode extension part by using the current blocking layer, It is possible to provide a light emitting diode capable of preventing light loss due to the pad and the electrode extending portion.

1 is a schematic plan view for explaining a light emitting diode according to a related art.
FIG. 2 is a cross-sectional view taken along a perforated line AA of FIG. 1 to describe a light emitting diode according to the prior art.
3 is a schematic plan view illustrating a light emitting diode according to an embodiment of the present invention.
4 is a cross-sectional view taken along the tear line BB in Fig.
5 is a schematic cross-sectional view for explaining a lamination structure of electrode extension lines.
6 is a schematic plan view illustrating a light emitting diode according to another embodiment of the present invention.
7 is a schematic plan view illustrating a light emitting diode according to another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are provided by way of example so that those skilled in the art can fully understand the spirit of the present invention. Therefore, the present invention is not limited to the embodiments described below, but may be embodied in other forms. In the drawings, the width, length, thickness, and the like of the components may be exaggerated for convenience. Like reference numerals designate like elements throughout the specification.

3 is a schematic plan view illustrating a light emitting diode according to an embodiment of the present invention, and FIG. 4 is a cross-sectional view taken along a perforated line B-B of FIG. 3, respectively.

3 and 4, the light emitting diode includes a substrate 51, a first conductive semiconductor layer 53, an active layer 55, a second conductive semiconductor layer 57, a transparent electrode layer 59, Layer 61, a first electrode pad 63, a second electrode pad 65, first electrode extension lines 63a and second electrode extension lines 65a and 65b. In addition, the light emitting diode may include a buffer layer (not shown) and a current blocking layer 58.

The substrate 51 may be, for example, a growth substrate for growing a gallium nitride compound semiconductor layer such as a sapphire substrate, a gallium nitride substrate, a silicon carbide substrate, or a silicon substrate, but is not limited thereto.

The first conductive semiconductor layer 53 is disposed on the substrate 51 and the second conductive semiconductor layer 57 is disposed on the first conductive semiconductor layer 53. The first conductive semiconductor layer 53 And the second conductivity type semiconductor layer 57. The active layer 55 is formed on the second conductivity type semiconductor layer 57, The first conductive semiconductor layer 53, the active layer 55 and the second conductive semiconductor layer 57 may be formed of a gallium nitride compound semiconductor material, that is, (Al, In, Ga) N. The compositional element and composition ratio are determined so that the active layer 55 emits light of a desired wavelength, for example, ultraviolet light or visible light.

The first conductive semiconductor layer 53 may be an n-type nitride semiconductor layer, the second conductive semiconductor layer 57 may be a p-type nitride semiconductor layer, or vice versa.

As shown in the figure, the first conductive semiconductor layer 53 and / or the second conductive semiconductor layer 57 may be formed as a single layer or may have a multi-layer structure. In addition, the active layer 55 may have a single quantum well structure or a multiple quantum well structure. In addition, when the substrate 51 is a growth substrate, a buffer layer (not shown) such as GaN or AlN may be interposed between the substrate 51 and the first conductivity type semiconductor layer 53. The semiconductor layers 53, 55 and 57 may be formed using MOCVD or MBE techniques.

On the other hand, the transparent electrode layer 59 may be positioned on the second conductive type semiconductor layer 57. The transparent electrode layer 59 may be formed of a transparent oxide such as ITO or Ni / Au and is ohmically contacted with the second conductive type semiconductor layer 57. [

The first electrode pad 63 and the first electrode extension lines 63a are located on the first conductivity type semiconductor layer 53 and are electrically connected to the first conductivity type semiconductor layer 53. [ The first electrode pad 63 and the first electrode extension lines 63a are located on the exposed first conductivity type semiconductor layer 53 by etching the second conductivity type semiconductor layer 57 and the active layer 55 .

In this embodiment, FIG. 3 shows a configuration in which two first electrode pads 63 are disposed for current dispersion in a light emitting diode having a large area of 1000 占 1000 占 퐉 or more, for example, about 1450 占 1450 占 퐉 And the five first electrode extension lines 63a extend from the first electrode pads 63. As shown in FIG. However, the present invention is not limited to this, and the number of the first electrode pads 63 and the number of the first electrode extension lines 63a may be changed. In particular, the number of the first electrode extension lines 63a may increase or decrease depending on the size of the light emitting diode.

The first electrode pads 63 may be disposed near one edge of the light emitting diode, and the first electrode extension lines 63a may extend from the first edge to the second edge. As shown in FIG. 3, the first electrode extension lines 63a may have straight portions parallel to each other.

On the other hand, the second electrode pad 65 and the second electrode extension lines 65a and 65b are located on the second conductivity type semiconductor layer 57, for example, on the transparent electrode layer 59. The second electrode extension lines 65a and 65b are electrically connected to the second conductive type semiconductor layer 57. [ For example, the second electrode extension lines 65a and 65b may be electrically connected to the second conductive type semiconductor layer 57 through the transparent electrode layer 59. [

In the present embodiment, two second electrode pads 65 are disposed for current dispersion, but the number of the second electrode pads 65 can be changed. The second electrode pads 65 may be disposed near the other edge of the substrate 51 so as to face the first electrode pads 65 and the second electrode extension lines 65a and 65b may be disposed near the other edge of the substrate 51, Extending in the direction opposite to the direction of the arrows 63a. That is, the second electrode extension lines 65a and 65b extend from the other edge to the one edge.

Also, two second electrode extension lines 65a and 65b are located between neighboring first electrode extension lines. In the present embodiment, two second electrode extension lines 65a and 65b are disposed anywhere between neighboring first electrode extension lines 63a, but the present invention is not necessarily limited thereto. For example, two second electrode extension lines 65a and 65b are disposed only between specific first electrode extension lines 63a and one second electrode extension line 65a is provided between the other first electrode extension lines 63a. Lt; / RTI >

The two second electrode extension lines 65a and 65b may have linear portions that are parallel to each other and the linear portions of the second electrode extension lines 65a and 65b may be adjacent to the first electrode extension lines 63a, As shown in FIG.

Meanwhile, the distance D2 between the two second electrode extension lines 65a and 65b may be in the range of 10 to 200 mu m. Meanwhile, the width of the second electrode extension lines 65a and 65b may be, for example, in the range of 1 to 20 mu m. Furthermore, the interval D2 is smaller than 1/3 of the interval D1 between the two neighboring first electrode extension lines 63a. If D2 is larger than 1/3 of D1, it is difficult to sufficiently disperse the current in the region between the two second electrode extension lines 65a and 65b. On the other hand, the interval D2 may be larger than 1/10 of the interval D1, and may be larger than 1/5 or 1/4.

The light output can be improved by disposing the two second electrode extension lines 65a and 65b between the neighboring first electrode extension lines 63a and further the gap between the second electrode extension lines 65a and 65b The light efficiency is improved.

In the present embodiment, it is described that the two second electrode extension lines 65a and 65b are disposed between adjacent first electrode extension lines 63a. However, the present embodiment is not limited to this, Two electrode extension lines may be arranged. In a case where n (n? 2) second electrode extension lines are disposed between neighboring first electrode extension lines, the interval D2 between the second straight line portions adjacent to each other of the adjacent second electrode extension lines is Is preferably smaller than 1 / (n + 1) of the interval D1 between the first rectilinear portions of the first electrode extension lines which are parallel to each other. Further, the interval between the second straight line portions of the neighboring second electrode extension lines is larger than 0, and in particular, the interval between the first straight line portions of the neighboring first electrode extension lines is 1 / (n + 2).

The current blocking layer 58 may be disposed under the second electrode pads 65 and the second electrode extension lines 65a and 65b. The current blocking layer 58 is disposed between the transparent electrode layer 59 and the second conductive type semiconductor layer 57 and extends from the second electrode pads 65 and the second electrode extension lines 65a and 65b It is possible to prevent current from concentrating on the second conductive type semiconductor layer 57 below. The current block layer 58 has a slightly wider width than the second electrode pads 65 and the second electrode extension lines 65a and 65b.

On the other hand, the insulating layer 61 covers and protects the first conductivity type semiconductor layer 53, the active layer 55, and the second conductivity type semiconductor layer 57. The insulating layer 61 may cover the transparent electrode layer 59. The insulating layer 61 may have openings for exposing the first conductivity type semiconductor layer 53 and openings for exposing the second conductivity type semiconductor layer 57 or the transparent electrode layer 59, The first electrode extension lines 63a and the second electrode extension lines 65a and 65b may be located in these openings. The insulating layer 61 may be formed of SiO2 or Si3N4, for example.

Although the first electrode pads 63 are disposed on the first conductivity type semiconductor layer 53 and are directly electrically connected to the first conductivity type semiconductor layer 53 in the present embodiment, The positions of the pads 63 are not particularly limited. For example, the first electrode pads 63 may be located on the exposed substrate 51 by etching the first conductive type semiconductor layer 53. Although the second electrode pads 63 are disposed on the second conductive semiconductor layer 57, for example, on the transparent electrode layer 59 in the present embodiment, the second electrode pads 65 May be located on the exposed first conductivity type semiconductor layer 53 by etching the second conductive type semiconductor layer 57 and the active layer 55 and may be formed on the first conductive type semiconductor layer 53 by the insulating layer such as the current blocking layer 58 1 conductivity type semiconductor layer 53. In this case,

Meanwhile, in the present embodiment, the first electrode extension lines 63a and the second electrode extension lines 65a and 65b may have the same metal lamination structure. The metal layered structure may have a structure of a contact layer 71 / a reflection layer 73 / a barrier layer 76 / a bonding layer 79.

The contact layer 71 has a thickness in the range of 1 to 50 angstroms, for example, and is used for ohmic contact with the first conductive type semiconductor layer 53. The contact layer 71 may be formed of Ni, Cr, or Ti. When Ni is used as the contact layer 71, it is possible to achieve a good n-ohmic contact with a relatively very thin thickness, for example, a thickness of about 5 Å, thereby lowering the light loss. The reflective layer 73 reflects light generated in the active layer 55 and is absorbed by the first and second electrode pads 63 and 65 and the first and second electrode extension lines 63a and 65a and 65b To prevent loss. The reflective layer 73 may be formed of aluminum. The thickness of the reflective layer 73 is preferably set to be thin within a range capable of achieving a reflective function. For example, the reflective layer 73 may have a thickness of 1000 to 3000 ANGSTROM. The barrier layer 76 is used to prevent intermixing of the bonding layer metal and the reflective layer metal to maintain the reflection function of the reflective layer. The barrier layer 76 may be formed of a double layer 75 or 77 such as Cr / Pt, Ni / Ti, or Ni / Pt. However, the barrier layer 76 may be a single layer Or Ni / Ti / Ni / Ti. The bonding layer 79 is formed of a bonding metal for bonding a bonding wire (not shown), for example, Au. The bonding layer 79 may be formed to a thickness of 1 um or more.

By adopting the above metal laminated structure, the first bonding pad 63, the second bonding pad 65, the first electrode extension lines 63a and the second electrode extension lines 65a and 65b are formed together in the same process It is possible to simplify the process.

Although the first electrode extension lines 63a are disposed near both side edges of the substrate 51 in the present embodiment, the present invention is not limited thereto, and the second electrode extension lines 63a And may be disposed near both side edges of the substrate 51.

6 is a schematic plan view illustrating a light emitting diode according to another embodiment of the present invention.

Referring to FIG. 6, a light emitting diode according to the present embodiment is substantially similar to the light emitting diode described with reference to FIG. 3, so that the same contents will be omitted to avoid duplication and different points will be described.

Although the second electrode extension lines 65c are disposed near both side edges of the substrate 51 in this embodiment, the first electrode extension lines 63a may be arranged near both side edges of the substrate 51 It is possible.

Meanwhile, the first electrode extension lines 63a may include bent portions other than the straight line portion, and the first auxiliary extension line 63b may branch off from the first electrode extension line 63a. Here, the "auxiliary extension line" means an extension line branched from the electrode extension line, which is an extension of the main extension, whose extension is less than 1/4 of the length of the edge of the light emitting diode. Even if branched from one main extension line, if the length is 1/4 or more, it is taken as an electrode extension line. On the other hand, the main extension line and the branch extension line are defined as the main extension line that the angle formed by the end portion of the extension line before the branching and the start portion of the extension line after the branching is close to 180 degrees, and the branch extension line is smaller than 180 degrees.

On the other hand, neighboring first electrode extension lines 63a may have straight portions parallel to each other. Two second electrode extension lines 65a and 65b are positioned between neighboring first electrode extension lines 63a. The two second electrode extension lines 65a and 65b also have straight portions parallel to each other. The straight portions of the two second electrode extension lines 65a and 65b may be parallel to the straight portions of the first electrode extension lines 63a. The spacing between the straight portions of the second electrode extension lines 65a and 65b may be in the range of 10 to 200 占 퐉. In addition, the spacing between the linear portions of the adjacent first electrode extension lines 63a D1-D2. That is, the interval between the linear portions of the second electrode extension lines 65a and 65b is smaller than 1/3 of the interval between the linear portions of the first electrode extension lines 63a, and the distance between the first electrode extension lines 63a, 1/5, or 1/4 of the spacing between the straight portions of the substrate.

Further, the second auxiliary extension lines 65s may be branched at the first electrode extension lines 63a, 63b, 63c. The first auxiliary extension lines 63b and the second auxiliary extension lines 65s extend to portions where the electric current is hardly dispersed, thereby assisting current dispersion.

7 is a schematic plan view illustrating a light emitting diode according to another embodiment of the present invention.

7, the light emitting diode according to the present embodiment is substantially similar to the light emitting diode described with reference to FIG. 6, except that the first auxiliary extension 63b and the corresponding end portion of the first electrode extension line 63a And the second auxiliary extension 65s is added to the second electrode extension line 65c.

It is possible to prevent the light emitting area from being reduced by adding the second auxiliary extension 65s instead of using the first auxiliary extension 63b. Further, by forming the second auxiliary extending portions 65s in a metal laminated structure including the reflecting layer 73 as described above with reference to FIG. 5, light loss due to the second auxiliary extending portions 65s can be reduced , The overall light output and the light efficiency can be improved.

(Experimental Example)

In order to compare the influence of the conventional electrode extensions and the electrode extensions according to the present invention on the optical characteristics of light emitting diodes of the same size, the light emitting diodes having the electrode extension lines as shown in FIG. 1 and the electrode extension lines as shown in FIG. Emitting diode was formed on the same substrate to measure Vf (@ 350 mA) and light output at the wafer level. In order to confirm the difference according to the interval D2 between the second electrode extension lines 65a and 65b according to the present invention, D2 was made to be 40, 70 and 100 μm. The sizes of the light emitting diodes were all 1450 μm × 1450 μm, and the line widths of the first and second electrode extension lines were all 8 μm. In addition, in order to compare the electrical and optical characteristics according to the patterns of the electrode extension lines, the lamination structure of the electrode pads and the electrode extension lines was formed in the same manner as Ni / Al / Cr / Pt / Au. The electrical characteristics and the optical characteristics according to the pattern were prepared for both the case where no current block layer CBL was used and the case where a current blocking layer was used for both.

Table 1 shows the relative values of Vf and light output measured by different patterns of electrode extension lines without using a current blocking layer. Here, Vf represents an increased amount based on Vf of a light emitting diode (comparative example) using a pattern according to the prior art, and the light output is increased with reference to the light output of the light emitting diode using the pattern according to the related art Of the total amount was expressed as a percentage.

Sample Peak wavelength (nm) Vf (V) @ 350mA Optical output Po (%) Comparative Example 452.38 - - D2: 40um 452.40 0.04 0.65 D2: 70um 452.40 0.03 0.90 D2: 100um 452.45 0.02 1.24

Referring to Table 1, when all other conditions such as the LED size, the semiconductor lamination structure, and the metal lamination structure are the same and only the pattern of the electrode extension line is different, the light emitting diodes of the embodiments according to the present invention, The peak wavelength is almost unchanged, Vf is slightly increased, and the light output is increased. In particular, it can be seen that as the distance D2 between the second electrode extension lines increases, Vf decreases and the light output increases. In Fig. 3, since D1 is about 350 mu m, it can be predicted that the light efficiency is the best when it is smaller than 1/3 of D1 and larger than 1/4.

Table 2 shows the measurement data when the current block layer is applied to all the samples under the same conditions as those in Table 1.

Sample Peak wavelength (nm) Vf (V) @ 350mA Optical output Po (%) Comparative Example 451.65 - - D2: 40um 451.69 0.06 1.20 D2: 70um 451.68 0.04 1.57 D2: 100um 451.70 0.03 1.76

Referring to Table 2, as shown in Table 1, the peak wavelengths of the light emitting diodes according to the embodiments of the present invention are almost unchanged, Vf is slightly increased, and the light output is increased as compared with the comparative example . The increase amount of Vf and the light output increase amount are larger than those of Table 1 and it can be seen that Vf decreases and the light output increases as the distance D2 between the second electrode extension lines increases.

It can be seen from the above experimental results that by arranging the two second electrode extension lines between the first electrode extension lines, at least a light output equal to or better than that of the prior art can be obtained.

21, 51 substrate, 23, 53 first conductive semiconductor layer
25, 55 active layer 27, 57 second conductive semiconductor layer
58 Current block layer, 29, 59 Transparent electrode layer
31, 61 insulation layer 33, 63 first electrode pad
33a, 63a First electrode extension line 63b First auxiliary extension line
35, 65 Second electrode pad 35a, 65a, 65b, 65c Second electrode extension line
65s Second auxiliary extension line, 71 Contact layer
73 reflective layer, 76 (75, 77) barrier layer 79 bonding layer

Claims (13)

A first conductive semiconductor layer;
A second conductivity type semiconductor layer;
An active layer disposed between the first conductive semiconductor layer and the second conductive semiconductor layer;
A plurality of first electrode extension lines electrically connected to the first conductivity type semiconductor layer;
A first electrode pad electrically connected to the first electrode extension lines;
A plurality of second electrode extension lines electrically connected to the second conductivity type semiconductor layer;
And a second electrode pad electrically connected to the second electrode extension lines,
The plurality of first electrode extension lines
A first 1-1 electrode extension line extending directly from the first electrode pad so that the second electrode pad is closer to an edge side of the adjacent first conductivity type semiconductor layer;
The first electrode pad extends along one side edge of the first conductive type semiconductor layer adjacent to the first electrode pad, and then the second electrode pad is extended to the edge side of the adjacent first conductive type semiconductor layer. An electrode extension line,
The first electrode extension line and the first electrode extension line are adjacent to each other,
Wherein the plurality of second electrode extension lines include at least two second electrode extension lines located between the adjacent first 1-1 electrode extension line and the 1-2 second electrode extension line. The method according to claim 1,
Wherein the at least two second electrode extension lines extend to the opposite side of the first electrode extension lines along the neighboring first electrode extension lines. The method of claim 2,
Wherein the at least two second electrode extension lines have second straight portions parallel to each other. The method of claim 3,
Wherein the adjacent first electrode extension lines have first straight portions parallel to each other,
Wherein the first rectilinear portions and the second rectilinear portions are parallel to each other. The method of claim 4,
(N + 1) of the interval (D1) between the mutually adjacent first rectilinear portions, and the interval (D2) between the neighboring second rectilinear portions is 1 / ) Light emitting diodes. The light emitting diode according to claim 5, wherein the interval (D2) is larger than 1 / (n + 2) of the interval (D1). The method according to claim 1,
And second auxiliary extension lines branched at the second electrode extension lines. The method of claim 7,
Further comprising first auxiliary extension lines that are branched at the first electrode extension lines. The method according to claim 1,
And a transparent electrode layer interposed between the plurality of second electrode extension lines and the second conductive type semiconductor layer. The method of claim 9,
And a current blocking layer for preventing a current from being injected from the second electrode extension lines into the second conductive type semiconductor layer in a region immediately below the second electrode extension lines. The method according to claim 1,
Wherein the plurality of first electrode extension lines and the plurality of second electrode extension lines have the same metal laminated structure,
Wherein the metal laminated structure comprises a contact layer, a reflective layer, a barrier layer, and a bonding layer. The method of claim 11,
Wherein the contact layer is formed of a metal selected from the group consisting of nickel, chromium, and titanium, the reflective layer is formed of aluminum, and the bonding layer is formed of gold. The method of claim 12,
Wherein the barrier layer is Ni, Ni / Ti, Ni / Ti / Ni / Ti, Cr / Pt or Ni / Pt.

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