KR101609866B1 - Light emitting diode for ac operation - Google Patents

Abstract

A light emitting diode having a plurality of light emitting cells formed on a substrate is disclosed. The light-emitting diode includes half-wave emitting units each having at least one light-emitting cell and having a first terminal and a second terminal at both ends, and a half-wave emitting unit having at least one light-emitting cell each having a third terminal and a fourth terminal at both ends, Units. Each of the third terminals of the light emitting units is electrically connected to the second terminals of the two half wave emitting units and each fourth terminal of the half wave emitting units is connected to the first terminals of another two half wave emitting units And are electrically connected in common. One half-wave emitting unit is connected in series between a third terminal of one radiating light emitting unit and a fourth terminal of another radiating light emitting unit among two neighboring two radiating light emitting units, Another half-wave emitting unit is connected in series between the fourth terminal and the third terminal of the other wave emitting unit. Accordingly, the efficiency of using the light emitting cells can be increased, and a light emitting diode that is stable to the reverse voltage can be provided.

AC, light emitting diode, light emitting cell

Description

LIGHT EMITTING DIODE FOR AC OPERATION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compound semiconductor light emitting diode, and more particularly, to a light emitting diode that can be connected to and driven by an AC power source.

Compound semiconductor light emitting diodes, for example, gallium nitride based light emitting diodes are widely used as display devices and backlights, and have lower power consumption and longer life than conventional light bulbs or fluorescent lamps, And the use area is widening.

The light emitting diode repeats on / off according to the direction of the current under the alternating current power supply. Therefore, when the light emitting diode is directly connected to the AC power source, the light emitting diode does not emit light continuously, and is easily damaged by the reverse current.

A light emitting diode capable of being directly connected to a high voltage AC power source to solve the problem of such a light emitting diode is disclosed in International Publication No. WO 2004/023568 (Al), entitled " LIGHT-EMITTING DEVICE HAVING LIGHT- (SAKAI et al.) Entitled " EMITTING ELEMENTS, " and light emitting diodes of various structures are being developed.

According to WO 2004/023568 (Al), LEDs form LED arrays connected two-dimensionally in series by metal wires on an insulating substrate such as a sapphire substrate. These two LED arrays are connected in anti-parallel on the substrate to emit light continuously by the AC power supply.

According to the disclosure in WO 2004/023568 (A1), one array is driven for half a period of AC power, and another array is driven for the next half period. That is, half of the light emitting cells in the light emitting diode are driven while the phase of the AC power is changed. Therefore, the use efficiency of the light emitting cells does not exceed 50%.

On the other hand, a light emitting diode which is driven under an AC power source by arranging an array of light emitting cells connected in series between two nodes of a bridge rectifier by using light emitting cells on a substrate is disclosed in Korean Patent Laid-Open Publication No. 10-2006-1800 ≪ / RTI > According to this, the array of the light emitting cells connected to the bridge rectifier can radiate the light regardless of the phase change of the AC power source, thereby increasing the use efficiency of the light emitting cells.

However, when the number of light emitting cells connected to the bridge rectifier is increased, a high voltage reverse voltage is applied to a specific light emitting cell in the bridge rectifier, so that the light emitting cell of the bridge rectifier is broken, and as a result, the light emitting diode may be damaged. In order to prevent this, it is possible to reduce the number of light emitting cells in the array of light emitting cells connected to the bridge rectifier, but in this case, it is difficult to provide a light emitting diode driven under a high voltage AC power source. On the other hand, the reverse voltage can be reduced by increasing the number of the light emitting cells constituting the bridge rectifier, but the use efficiency of the light emitting cells is reduced again.

SUMMARY OF THE INVENTION An object of the present invention is to provide an improved light emitting diode that can be driven under a high voltage AC power source.

Another object of the present invention is to provide a light emitting diode capable of reducing the reverse voltage applied to each of the light emitting cells in the light emitting diode while improving the use efficiency of the light emitting cells.

According to an aspect of the present invention, there is provided a light emitting diode having a plurality of light emitting cells on a substrate. The light emitting diode includes half-wave emitting units each having at least one light emitting cell and having a first terminal and a second terminal at both ends; And a plurality of light emitting units each having at least one light emitting cell and having a third terminal and a fourth terminal at both ends thereof. Each of the third terminals of the propagation light emitting units is electrically connected in common to the second terminals of the two half wave emitting units and each fourth terminal of the light emitting units is connected to the first terminal of another two half- Are electrically connected in common. One half-wave emitting unit is connected in series between a third terminal of one radiating light emitting unit and a fourth terminal of another radiating light emitting unit among two neighboring radiating light emitting units, And another half-wave emitting unit is connected in series between the fourth terminal of the other half-wave emitting unit and the third terminal of the other half-wave emitting unit.

Here, the half-wave emitting unit means a light emitting unit in which a forward voltage is applied for half a period of an AC power source and an inverse voltage is applied for another half period, and the forward light emitting unit means a light emitting unit to which a forward voltage is applied even when the phase of the AC power source is changed do. Further, the half-wave emitting unit and the full-wave emitting unit each have at least one light emitting cell, and when they have a plurality of light emitting cells, the light emitting cells in the light emitting unit are connected to each other in series.

By using the light emitting units, the efficiency of use of the light emitting cells in the light emitting diode can be improved since the light emitting units are driven under the AC power regardless of the phase change of the AC power. In addition, the arrays of half-wave emitting units can reduce the reverse voltage applied to the half-wave emitting unit by sharing the wave emitting units.

On the other hand, the half-wave emitting units connected in series between two neighboring two wave emitting units are effective to prevent breakage of the short wave emitting unit by the reverse voltage. Therefore, at least one of the semi-emissive units serially connected to the two adjacent light emitting units may have a single emissive cell, and further, Half-wave emitting units may all have a single light emitting cell.

Meanwhile, the propagation light emitting units may have a single light emitting cell or a plurality of light emitting cells. When each of the light emitting units has a single light emitting cell, the reverse voltage applied to the half-wave emitting units can be minimized, and when the light emitting units each have a plurality of light emitting cells, . Therefore, the number of light emitting cells in the propagation light emitting unit can be adjusted in consideration of the reverse voltage applied to the short-wave light emitting unit and the use efficiency of the light emitting cells.

The light emitting diode may further include two terminals for connection to an external power source. Each of the terminals is electrically connected to the anode terminal of one half-wave emitting unit and the cathode terminal of the other half-emitting unit. Accordingly, when the phase of the alternating current power is changed, a current flows into the light emitting diode along different paths.

Meanwhile, the size of the light emitting cells in the propagation light emitting unit may be the same as the size of the light emitting cells in the half-wave emitting unit. However, since the light emitting cells in the light emitting unit emit light during the entire cycle of the AC power source, It is preferable that the size of the light emitting cells in the light emitting unit is larger than the size of the light emitting cells in the half wave emitting unit.

According to the present invention, it is possible to provide a light emitting diode capable of increasing the efficiency of use of the light emitting cells while relieving an increase in the reverse voltage applied to the light emitting cells in the light emitting diode.

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, etc. of components may be exaggerated for convenience. Like reference numerals designate like elements throughout the specification.

1 is a schematic circuit diagram for explaining a light emitting diode 100 according to an embodiment of the present invention.

Referring to FIG. 1, the light emitting diode 100 has a plurality of light emitting cells 10 and 20. The light emitting cells 10 and 20 are formed on a single substrate and are electrically connected through wiring.

The light emitting diode 100 includes semi-wave emitting units h1, h2, h3, and h4 and wave emitting units a1 and a2. The half wave light emitting units h1, h2, h3 and h4 each have a first terminal (for example, an anode terminal) and a second terminal (for example, a cathode terminal) (E.g., an anode terminal) and a fourth terminal (e.g., a cathode terminal). The wires are connected to the first to fourth terminals to electrically connect the light emitting units h1, h2, h3, h4, a1 and a2.

Each of the half wave light emitting units h1, h2, h3 and h4 has at least one light emitting cell 10 and each of the wave emitting units a1 and a2 has at least one light emitting cell 20. When a plurality of light emitting cells are included in the light emitting units h1, h2, h3, h4, a1 and a2, the light emitting cells in the light emitting units are connected to each other in series.

Each of the third terminals of the light emitting units a1 and a2 is electrically connected in common to the second terminals of the two half-wave emitting units, and the fourth terminals of the light emitting units a1 and a2, Are electrically connected in common to the first terminals of the other two half-wave emitting units. 1, the third terminal of the electric wave light-emitting unit a2 is electrically connected in common to the second terminals of the half-wave light-emitting units h3 and h4, Are commonly connected to the first terminals of the half-wave emitting units h1 and h2.

Furthermore, one half-wave emitting unit (a2) is provided between the third terminal of one of the two wave-emitting units a1 and a2 and the fourth terminal of another one of the wave- another half-wave emitting unit h3 is connected in series between the fourth terminal of the one full wave light emitting unit a1 and the third terminal of the other half wave radiating unit a2, .

The light emitting diode 100 may have terminals t1 and t2 for connecting an external power source and the terminals t1 and t2 may be connected to a first terminal and a second terminal of two half- As shown in FIG. Two semi-wave emitting units connected to the terminal t1 are connected to the wave emitting unit a1, and two half wave emitting units connected to the terminal t2 are connected to another wave emitting unit.

The operation when the AC power source is connected to the terminals t1 and t2 will be described.

First, when a positive voltage is applied to the terminal t1, the current flows through the half-wave emitting unit (h2, left upper end) connected to the terminal t1 through the terminal t1, the wave emitting unit a1, Half wave emitting unit h3, wave emitting unit a2, half wave emitting unit h2, The half wave light emitting unit a1, the half wave wave emitting unit h3, the wave emitting unit a2 and the half wave emitting unit h2 to the terminal t2 so that light is emitted from these light emitting units.

Next, when a positive voltage is applied to the terminal t2, the current flows through the half-wave emitting unit (h4, lower right end), the wave emitting unit a2, Half wave emitting unit h1, wave emitting unit a1, The half-wave emitting unit h4, the wave emitting unit a2, the half-wave emitting unit h1, the wave emitting unit a1 and the half-wave emitting unit h4 to the terminal t1, Lt; / RTI >

While the positive voltage is applied to the terminal t1, the half-wave emitting units h2 and h3 emit light and the light emitting units a1 and a2 emit light, while a positive voltage is applied to the terminal t2 Half wave light emitting units h1 and h4 and the wave emitting units a1 and a2 emit light. That is, the half wave light emitting units h1 and h4 and the half wave wave emitting units h2 and h3 emit light alternately according to the phase of the AC power source, and the wave emitting units a1 and a2 emit light, And emits light in all phases irrespective of the phase.

Therefore, the number of light emitting cells driven by the number of light emitting cells in the light emitting units a1 and a2 can be increased, compared with the light emitting diodes in which the two serial arrays are alternately operated. Furthermore, when half-wave emitting units have a single light emitting cell, the efficiency of use of the light emitting cells can be maximized.

On the other hand, the reverse voltage applied to the half-wave emitting units h1, h2, h3 and h4 will be described.

H2 and h3 and the forward light emitting units a1 and a2 during a half period in which a positive voltage is applied to the terminal t1 and the half wave light emitting units h2 and h3 emit light, And a reverse voltage is applied to the half-wave emitting unit h1 or h4. The reverse voltage applied to the half wave light emitting unit h1 is divided into two wave emitting units a1 and a2 respectively connected to the first terminal and the second terminal thereof and one waveguide unit connected to the wave emitting units a1 and a2 Is equal to the sum of the forward voltages applied to the half-wave emitting unit h3. The reverse voltage applied to the half wave light emitting unit h4 is equal to the sum of the reverse voltages applied to the two wave emitting units a1 and a2 and the half wave light emitting unit h2.

Similarly, during the next half period when a positive voltage is applied to the terminal t2 to emit light by the half-wave emitting units h1 and h4, a reverse voltage is applied to the half-wave emitting units h2 and h3, The reverse voltage applied to the unit h2 or h3 is equal to the sum of the forward voltages applied to the two wave emitting units a1 and a2 and one half wave emitting unit h4 or h1.

When the half-wave emitting units h1, h2, h3 and h4 are constituted by the same light emitting cells, the reverse voltage applied to these half wave emitting units mainly depends on the number of light emitting cells of the light emitting units. Therefore, by controlling the number of light emitting cells in the light emitting units, it is possible to provide a light emitting diode which is safe to the reverse voltage.

According to this embodiment, by adopting the half-wave emitting units h1, h2, h3 and h4 and the wave emitting units a1 and a2 and adjusting the number of the light emitting cells therein, A light emitting diode capable of increasing the use efficiency of the light emitting diode can be provided.

FIG. 2 is a schematic circuit diagram showing an example of a light emitting diode in which half-wave emitting units and full-wave emitting units are all formed of a single light emitting cell, and FIGS. 3 and 4 are schematic plan views for explaining the light emitting diode of FIG. 2 .

Referring to FIGS. 2, 3 and 4, light emitting cells 10 operating for half a period and light emitting cells 20 operating for full period are located on a single substrate 21. The light emitting cells 10 and 20 may be formed together through the same manufacturing process, and the light emitting cells 10 and the light emitting cells 20 may have different sizes. These light emitting cells 10 have a first terminal and a second terminal, and the light emitting cells 20 have a third terminal and a fourth terminal, and the wiring 23 is connected to these terminals.

As described above, the light emitting cells 20 are commonly connected to the first terminals of the two light emitting cells 10 and are commonly connected to the second terminals of the other two light emitting cells 10. Further, the light emitting cells 10 are connected in series between the third terminal and the fourth terminal of the neighboring light emitting cells 20 and between the fourth terminal and the third terminal, respectively.

4A and 4B, the light emitting cells 10a and 10b formed on the single substrate 21 may share the first terminal or the second terminal. For this purpose, the light emitting cells 10a and 10b of the same polarity May be formed to share a semiconductor layer. For example, the light emitting cells 10a of FIG. 4 (a) are formed by sharing a lower semiconductor layer, and the light emitting cells 10b of FIG. 4 (b) are formed by sharing an upper semiconductor layer. As shown, the light emitting cells 10a of FIG. 4 (a) share a second terminal, and the light emitting cells of FIG. 4 (b) can share a first terminal.

The wiring structure for connecting the light emitting cells 10 and 20 is not particularly limited. As shown in the figure, another wiring is connected to the wiring connecting the light emitting cells 10, so that the light emitting cells 20 can be electrically connected to the light emitting cells 10. [ Alternatively, two light emitting cells 10 and one light emitting cell 20 may be electrically connected to each other through two wirings. For example, the third terminal of the light emitting cell 20 and the second terminals of the two light emitting cells 10 may be connected through wires.

The wirings 23 may be formed using a conventional wiring process, and may be formed, for example, by an air supporting process or a step cover process. Further, the wirings and the terminals may be formed by the same process and the same material.

5, 6, 7, 8, 9, and 10, the structure of the light emitting cells of the alternating current LED according to the embodiment of the present invention and the connection through the wiring will be described. Figures 5 and 6 are schematic cross-sectional views taken along section line A-A in Figure 3. Here, FIG. 5 is a partial cross-sectional view for explaining that the light emitting cells are electrically connected by the wires formed by the air bridge process, and FIG. 6 illustrates that the light emitting cells are electrically connected by the wires formed by the step cover process Fig.

Referring to FIG. 5, a plurality of light emitting cells 158 are spaced apart from each other on a single substrate 151. Each of the light emitting cells includes a first conductive type lower semiconductor layer 155, an active layer 157, and a second conductive type upper semiconductor layer 159. The active layer 157 may be a single quantum well structure or a multiple quantum well structure, and its material and composition are selected according to the required emission wavelength. For example, the active layer may be formed of an AlInGaN-based compound semiconductor, for example, InGaN. The lower and upper semiconductor layers 155 and 159 are formed of a material having a larger bandgap than the active layer 157 and may be formed of an AlInGaN-based compound semiconductor, for example, GaN.

A buffer layer 153 may be interposed between the lower semiconductor layer 155 and the substrate 151. The buffer layer 153 is employed to alleviate the lattice mismatch between the substrate 151 and the lower semiconductor layer 155. The buffer layer 153 may be spaced apart from each other as shown in the drawing. However, the buffer layer 153 may be continuous with the buffer layer 153 when the buffer layer 153 is formed of a material having high insulation or resistance.

The upper semiconductor layer 159 is located above a partial region of the lower semiconductor layer 155 and the active layer is interposed between the upper semiconductor layer 159 and the lower semiconductor layer 155. In addition, the transparent electrode layer 161 may be positioned on the upper semiconductor layer 159. The transparent electrode layer 161 may be formed of a material such as indium tin oxide (ITO) or Ni / Au.

On the other hand, the wires 167 electrically connect the light emitting cells 158. The wirings 167 connect the lower semiconductor layer 155 of one light emitting cell and the transparent electrode layer 161 of the adjacent light emitting cell. The wirings may connect the p-electrode 164 formed on the transparent electrode layer 161 and the n-electrode 165 formed on the exposed region of the lower semiconductor layer 155, as shown in the figure. Here, the electrodes 164 and 165 function as an anode terminal and a cathode terminal of the light emitting cell, respectively. Here, the wirings 167 are formed by an air bridge process, and a portion except for the contact portion is physically separated from the substrate 151 and the light emitting cells 158. An array in which the light emitting cells are connected in series on the single substrate 151 is formed by the wirings 167.

Referring to FIG. 6, wires connecting the light emitting cells 158 may be formed by a step cover process. That is, all the layers of the light emitting cells and the substrate 151 are covered with the insulating layer 185, except for portions for contacting the wirings 187. The wires 187 electrically connect the light emitting cells on the insulating layer 185.

For example, the insulating layer 185 has openings for exposing the electrodes 164 and 165, and the wires 187 connect the electrodes 164 and 165 of neighboring light emitting cells through the openings, Thereby connecting the light emitting cells in series.

The electrodes 164 and 165 of the light emitting cells may be formed of the same material as the wirings 187 and may be formed together when the wirings 187 are formed. That is, the electrodes 164 and 165 are not formed separately, and the wirings 187 are directly electrically connected to the lower semiconductor layer 157 and the upper semiconductor layer 159 or the transparent electrode layer 161 .

Figures 7 and 8 are schematic partial cross-sectional views taken along section line B-B in Figure 4 (a). 7 is a partial cross-sectional view for explaining that the light emitting cells are electrically connected by the wirings 167 formed by the air bridge process, and Fig. 8 is a partial cross-sectional view illustrating the light emitting cells by the wires 187 formed by the step- Are electrically connected to each other.

As described above, the structure of the light emitting cells 158 is similar, but the first conductive type lower semiconductor layer 153 is formed to be shared with each other. At this time, an electrode, for example, an n-electrode 165 formed on the first conductive type lower semiconductor layer 153 may be formed between the second conductive type upper semiconductor layers 159, 165 may be formed so that the distance from the second conductive upper semiconductor layers 159 is constant. On the other hand, the second conductive upper semiconductor layers 159 are separated from each other.

Figs. 9 and 10 are schematic partial cross-sectional views taken along the perforated line C-C of Fig. 4 (b). 9 is a partial cross-sectional view for explaining that the light emitting cells are electrically connected by the wirings 167 formed by the air bridge process, and Fig. 10 is a partial cross-sectional view for explaining the connection of the light emitting cells by the wires 187 formed by the step- Are electrically connected to each other.

As described above, the structure of the light emitting cells 158 is similar, but the second conductive type upper semiconductor layers 159 are formed to be mutually shared. At this time, the first conductive type lower semiconductor layer 155 and the active layer 157 formed below may be separated from each other, and the space between the lower semiconductor layers 155 may be filled with the insulating layer 189.

11 illustrates plan views for explaining the shapes of various light emitting cells and various electrode arrangements that can be used in a light emitting diode according to an embodiment of the present invention. Here, although the electrodes are shown connected to the wirings, as described above, the wirings and the electrodes can be formed together by the same process.

11 (a), electrodes (e.g., an n-electrode and a p-electrode) are formed on the first conductive-type lower semiconductor layer and the second conductive-type upper semiconductor layer of the light emitting cell, And an extension extending from a portion to which the wiring is connected. The extension of the n-electrode and the extension of the p-electrode are formed symmetrically with respect to each other and may be formed parallel to each other. The wirings may be connected to the center of the corresponding electrode, respectively.

11 (b), electrodes (n-electrode and p-electrode) are formed on the first conductive-type lower semiconductor layer and the second conductive-type upper semiconductor layer of the light emitting cell, respectively, An electrode, for example, a p-electrode, formed on the semiconductor layer may be formed at a central portion on the light emitting region. The electrodes may be formed to include extension portions as described with reference to FIG. 11 (a).

Referring to Fig. 11 (c), the wirings are substantially similar to Fig. 11 (a), but wirings are connected to the electrodes in the vicinity of the edges of the first conductive type lower semiconductor layer and the second conductive type lower semiconductor layer, respectively. The wirings are connected to the electrodes at a symmetrical portion on the diagonal line of the light emitting cells, and the electrodes each have extensions extending along the edges of the light emitting cells at the portions to which the wirings are connected. The extensions may be formed parallel to each other, and thus the distance between the extensions may be substantially the same.

Referring to FIG. 11 (d), electrodes are formed on the first conductive type lower semiconductor layer and the second conductive type upper semiconductor layer of the light emitting cell, and the electrodes are arranged diagonally symmetrically with respect to each other. The electrodes may have a plurality of extensions, which may be formed along the edge of the light emitting cell. Also, the corresponding extensions of the n-electrode and the p-electrode may be parallel to each other. Also, they are symmetrically positioned symmetrically with respect to each other on the diagonal lines of the light emitting cells.

Referring to FIG. 11 (e), the light emitting cells may have a trapezoidal shape. In this case, one of the electrodes may have a triangular shape. For example, as shown in the figure, when the light emitting region has a rectangular shape, the n-electrode may have a triangular shape. Alternatively, when the luminescent region has a trapezoidal shape, the p-electrode may have a triangular shape.

Referring to Fig. 11 (f), the wirings can be connected to the electrodes on the same side of the light emitting cell. The electrodes may have an extension extending along the edges of the first conductive lower semiconductor layer and the second conductive upper semiconductor layer from the portion to which the wirings are connected. These extensions may be parallel to each other.

Referring to Fig. 11 (g), wirings can be connected to the electrodes on the opposite sides of the light emitting cells. The electrodes may have an extension extending along the edges of the first conductive lower semiconductor layer and the second conductive upper semiconductor layer from the portion to which the wirings are connected. These extensions may be parallel to each other.

Referring to FIG. 11 (h), the light emitting cells may have a parallelogram shape. The electrodes may have a plurality of extensions, each extending around an edge, each extending along an edge of the light-emitting cell. Further, corresponding extensions of the n-electrode and the p-electrode may be formed parallel to each other.

Although the structure of the light emitting cells and the connection of the light emitting cells through the wiring have been described in detail, various modifications can be made to the structure and wiring of the light emitting cells. .

On the other hand, in the present embodiment, the short-wave light emitting units and the radio wave emitting units are described as an example of a single light emitting cell, but these light emitting units may be composed of a plurality of light emitting cells. In particular, the short-wave light emitting unit may be composed of one light emitting cell and the light emitting units may be composed of a plurality of light emitting cells. An example in which the half-wave emitting units are each composed of one light emitting cell and the light emitting units are composed of two light emitting cells is shown in a schematic circuit diagram in FIG.

Referring to Fig. 12, each of the light emitting units has two light emitting cells. Therefore, the use efficiency of the light emitting cells is increased as compared with the case where the light emitting units each have one light emitting cell.

The propagation light emitting units may have two or more light emitting cells, and it is not required that the propagation light emitting units all have the same number of light emitting cells. On the other hand, when the number of light emitting cells in the radio wave emitting units is increased, the reverse voltage of the half wave emitting unit is increased. Therefore, the number of light emitting cells in the radio wave emitting unit is selected in consideration of the reverse voltage of the half-wave emitting unit, and can be selected in a range of preferably 1 to 10.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Therefore, it should be understood that the above-described embodiments are not intended to limit the scope of the present invention, but merely to facilitate a better understanding thereof. The scope of the present invention is not to be limited by these embodiments, but should be construed according to the following claims, and equivalents thereof are to be construed as being included in the scope of the present invention.

1 is a schematic circuit diagram illustrating a light emitting diode according to an embodiment of the present invention.

2 is a schematic circuit diagram for explaining an example of a light emitting diode according to an embodiment of the present invention.

FIG. 3 is a schematic plan view for explaining the light emitting diode of FIG. 2. FIG.

4 (a) and 4 (b) are other schematic plan views for explaining the light emitting diode of FIG.

5 and 6 are schematic partial cross-sectional views taken along the perforated line A-A of FIG. 3 to illustrate light emitting diodes usable in the embodiments of the present invention.

Figs. 7 and 8 are partial cross-sectional views taken along the tear line B-B in Fig. 4 (a).

Figs. 9 and 10 are partial cross-sectional views taken along the perforated line C-C in Fig. 4 (b).

11 is a plan view for explaining various shapes and various electrode arrangements of light emitting cells used in a light emitting diode according to embodiments of the present invention.

12 is a schematic circuit diagram for explaining another example of a light emitting diode according to an embodiment of the present invention.

Claims (19)

A light emitting diode having a plurality of light emitting cells formed on a substrate, At least four half-wave emitting units each having at least one light emitting cell and having a first terminal and a second terminal at both ends; And At least two light emitting units each having at least one light emitting cell and having a third terminal and a fourth terminal at both ends, Wherein at least one third terminal of at least one of the propagation light emitting units is electrically connected to second terminals of two half wave emitting units, Which are electrically connected to the first terminals, At least one half-wave-emitting unit is connected in series between the third terminal of one of the two wave-emitting units and the fourth terminal of the other wave-emitting unit, and the fourth half of the one wave- Another half-wave emitting unit is connected in series between the terminal and the third terminal of the other wave emitting unit, Wherein the light emitting cells adjacent to each second terminal in the two half-wave emitting units share a semiconductor layer of the same polarity. The method according to claim 1, The third terminal of at least one of the light emitting units is electrically connected to the second terminals of the two half-wave emitting units, because the light emitting cells adjacent to each second terminal in the two half- And a light emitting diode (LED). The method of claim 2, And the electrode of the same polarity is formed on the shared same polarity semiconductor layer. The method of claim 2, And the electrode of the same polarity is an n-electrode. The method of claim 2, And the electrode of the same polarity is a p-electrode. The method according to claim 1, Wherein the propagation light emitting units each have a plurality of light emitting cells. The method according to claim 1, Further comprising at least two bonding pads for connection to an external power supply, wherein each of the bonding pads is electrically connected to a first terminal of one half-wave emitting unit and a second terminal of the other half-wave emitting unit Light emitting diode. The method of claim 7, Wherein the two bonding pads are further formed on the substrate. The method of claim 8, Wherein the bonding pads further formed on the substrate and the plurality of light emitting cells are arranged to have a generally rectangular shape. The method according to claim 1, Wherein the size of the light emitting cell in the propagation light emitting unit is larger than the size of the light emitting cell in the half wave light emitting unit. The method according to claim 1, Wherein the plurality of light emitting cells each include an n-electrode and a p-electrode, and at least one of the plurality of light emitting cells further includes an extension extending from the n-electrode or the p-electrode. diode. The method of claim 11, At least one of the plurality of light emitting cells further includes an extension extending from each of the n-electrode and the p-electrode, wherein the extension extending from the n- electrode and the extension extending from the p- And a light emitting diode. The method of claim 12, Wherein an extension extending from the n-electrode and an extension extending from the p-electrode are parallel to each other. The method of claim 12, Wherein the extending portion extending from the n-electrode and the extending portion extending from the p-electrode are symmetrical with respect to each other on the diagonal line of the light emitting cells. The method of claim 12, Wherein the plurality of light emitting cells have substantially the same distance between an extension extending from the n-electrode and an extension extending from the p-electrode. The method of claim 11, At least one of the plurality of light emitting cells further comprises at least two extensions extending from the n-electrode and the p-electrode, respectively, and extending from the n-electrode and extending from the p- Wherein the extended portions are symmetrical to each other. 18. The method of claim 16, Wherein each of the extensions extending from the n-electrode is parallel to each of the extensions extending from the corresponding p-electrode. The method according to claim 1, Wherein the structure of claim 1 is repeatedly formed. 18. The method of claim 16, Wherein the structure of Claim 1 is made only of a structure formed repeatedly.

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