KR20100084457A - Light emitting diode having plurality of light emitting cells - Google Patents

Abstract

A light emitting diode having a plurality of light emitting cells is disclosed. This light emitting diode is arranged on a single substrate and includes a plurality of light emitting cells each having a first terminal and a second terminal. A first insulating layer covers the light emitting cells. The first insulating layer has openings exposing the first terminal and the second terminal of each light emitting cell. Meanwhile, wires are formed on the first insulating layer to electrically connect the light emitting cells through the openings of the first insulating layer. At least one of the wires electrically connects the four light emitting cells, and electrically connects the second terminals of the two light emitting cells and the first terminals of the other two light emitting cells.

Description

LIGHT EMITTING DIODE HAVING PLURALITY OF LIGHT EMITTING CELLS

The present invention relates to a compound semiconductor light emitting diode, and more particularly, to a light emitting diode having a plurality of light emitting cells that can be driven connected to an AC power source.

Compound semiconductor light emitting diodes such as gallium nitride-based light emitting diodes are widely used as display devices and backlights, and consume less power and have longer lifetimes than conventional light bulbs or fluorescent lamps. It is expanding the use area.

The light emitting diode is repeatedly turned on and off in accordance with the direction of the current under an AC power supply. Accordingly, when the light emitting diode is directly connected to an AC power source, the light emitting diode does not emit light continuously and is easily broken by reverse current.

In order to solve the problem of the light emitting diode, a light emitting diode which can be directly connected to a high voltage AC power source is disclosed in International Publication No. WO 2004/023568 (Al) "Light-Emitting Device Having Light-Emitting Components". EMITTING ELEMENTS has been disclosed by SAKAI et. Al., And light emitting diodes of various structures have been developed.

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

On the other hand, as disclosed in WO 2004/023568 (Al), one array is driven during the half cycle of an AC power source, and the other array is driven during the next half cycle. That is, half of the light emitting cells in the light emitting diodes are driven while the phase of the AC power source is changed. Therefore, the use efficiency of the light emitting cells does not exceed 50%.

On the other hand, a light emitting diode driven under an AC power source by making a bridge rectifier using light emitting cells on a substrate and arranging an array of light emitting cells connected in series between two nodes of the bridge rectifier is disclosed in Korean Patent Application Laid-Open No. 10-2006-1800. It is disclosed in the call. According to this, the array of light emitting cells connected to the bridge rectifier propagates and emits light regardless of the phase change of the AC power, 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, and thus, the light emitting cell of the bridge rectifier may be damaged, and as a result, the light emitting diode may be damaged. In order to prevent this, the number of light emitting cells in the array of light emitting cells connected to the bridge rectifier can be reduced, but in this case, it is difficult to provide a light emitting diode driven under a high voltage AC power supply. Meanwhile, the reverse voltage may be decreased by increasing the number of light emitting cells constituting the bridge rectifier. However, the use efficiency of the light emitting cells decreases again.

On the other hand, efforts to improve the light emission output relative to the chip area of the AC light emitting diode and efforts to improve the reliability are continuing. In particular, there is a need for a light emitting diode in which a plurality of light emitting cells are arranged in a limited area of a chip having a rectangular planar outline and are effectively connected to each other using wirings, and safe wiring connection is also required.

The problem to be solved by the present invention is to provide an improved light emitting diode that can be driven under a high voltage AC power supply.

Another object of the present invention is to provide a light emitting diode having wirings that effectively connect light emitting cells arranged on a single substrate.

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

Another object of the present invention is to provide a light emitting diode capable of increasing the integration degree of a plurality of light emitting cells in a limited area.

Another problem to be solved by the present invention is to provide a light emitting diode which can prevent the disconnection of the wiring and prevent damage to the wiring by external force or moisture.

In order to solve the above problems, the present invention provides a light emitting diode having a plurality of light emitting cells. The light emitting diode includes: a plurality of light emitting cells arranged on a single substrate and each having a first terminal and a second terminal; A first insulating layer covering the light emitting cells and having openings exposing first and second terminals of each light emitting cell; And wires formed on the first insulating layer to electrically connect the light emitting cells through the openings of the first insulating layer. Here, at least one of the wires electrically connects the four light emitting cells, and electrically connects the second terminals of the two light emitting cells and the first terminals of the other two light emitting cells.

The light emitting cells may include a first conductive semiconductor layer, a second conductive semiconductor layer positioned on a portion of the first conductive semiconductor layer, and an active layer interposed between the first and second conductive semiconductor layers. It may include.

The first terminal and the second terminal are both terminals through which a current flows in and out of the light emitting cell, and may be any one as long as wires are connected thereto. For example, the second terminal may be an electrode formed on the first conductive semiconductor layer or the first conductive semiconductor layer, and the first terminal may be on the second conductive semiconductor layer or the second conductive semiconductor layer. The electrode may be formed on the transparent electrode layer formed on the second conductive semiconductor layer or on the transparent electrode layer.

Meanwhile, the two light emitting cells are disposed between the other two light emitting cells. The first conductive semiconductor layers of the two light emitting cells may be separated from each other, but may be connected to each other. When the first conductive semiconductor layers of the two light emitting cells are connected to each other, wiring of the two light emitting cells can be easily connected, and disconnection of the wiring due to a step between the light emitting cells can be prevented. Here, the first conductive semiconductor layers connected to each other means that they are connected without being physically separated.

The light emitting cells may be formed to be inclined. That is, sidewalls of the first conductive semiconductor layer and the second conductive semiconductor layer may be inclined. Accordingly, disconnection of the wirings can be prevented.

Further, the first conductive semiconductor layer may have a first inclined surface and a second inclined surface, and the second inclined surface may be inclined more than the first inclined surface. By forming the first conductive semiconductor layer to have different inclined surfaces, disconnection of the wirings can be prevented and the light emitting cells can be highly integrated.

The light emitting diode may further include a second insulating layer covering the wires. The second insulating layer protects the wirings and the light emitting cells from external force or moisture. Furthermore, the first insulating layer may be relatively thicker than the second insulating layer. By forming the first insulating layer relatively thick, short circuits of the light emitting cells and the wirings can be prevented and dielectric breakdown of the first insulating layer can be prevented.

In some embodiments, the plurality of light emitting cells may include radio wave emitting cells and half wave emitting cells.

Here, the half-wave light emitting cell means a light emitting cell to which the forward voltage is applied during the half cycle of the AC power, and the reverse voltage is applied to the other half cycle, and the full-wave light emitting cell refers to the light emitting cell to which the forward voltage is applied even if the phase of the AC power is changed. do. By using the propagation light emitting cells, it is possible to increase the use efficiency of the light emitting cells in the light emitting diode.

The full-wave light emitting cell has a third terminal and a fourth terminal corresponding to the first terminal and the second terminal of the half-wave light emitting cell, respectively.

The wirings may include wiring (s) for electrically connecting a third terminal of one full-wave light emitting cell to second terminals of two half-wave light emitting cells. Meanwhile, the first conductivity type semiconductor layers of the two half wave light emitting cells may be connected to each other.

In addition, the wirings may include wiring (s) for electrically connecting the fourth terminal of one full-wave light emitting cell to the first terminals of two half-wave light emitting cells.

Meanwhile, the at least one wire may be disposed along an edge of the single substrate. Furthermore, two of the wires may electrically connect four light emitting cells, respectively. The wires electrically connect the second terminals of the two light emitting cells and the first terminals of the other two light emitting cells, respectively. In addition, the two wires may be disposed diagonally to each other along both edges of the single substrate.

According to the present invention, the light emitting cells can be effectively arranged on a single substrate having a limited area by adopting wirings that connect four light emitting cells in sequence. In addition, the insulating layer covering the wirings may be adopted to protect the wirings and the light emitting cells. Furthermore, by using the propagation light emitting cells, it is possible to provide a light emitting diode that can increase the use efficiency of the light emitting cells while alleviating an increase in the reverse voltage applied to the light emitting cells in the light emitting diode. In addition, it is possible to achieve stability of wiring by connecting the first conductivity-type semiconductor layers of the two light emitting cells to each other.

Hereinafter, with reference to the accompanying drawings will be described embodiments of the present invention; The following embodiments are provided by way of example to ensure that the spirit of the invention to those skilled in the art can fully convey. Accordingly, the present invention is not limited to the embodiments described below and may be embodied in other forms. In the drawings, the width, length, thickness, etc. of the components may be exaggerated for convenience. Like numbers refer to like elements throughout.

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

Referring to FIG. 1, the light emitting diode has a substrate 21, a plurality of light emitting cells 30, wires 37a, 37b, and 37c, and bonding pads 41 and 43. The light emitting cells 30 are formed on a single substrate 21 and are connected in series through the wirings 37a and 37b to form an array, and are connected to the bonding pads 41 and 43 by the wirings 37c. Connected. The arrays of light emitting cells 30 may be anti-parallel connected between the bonding pads 41 and 43 to be driven under AC power.

The substrate 21 may be any substrate as long as it can electrically insulate the light emitting cells 30. A growth substrate for growing a nitride semiconductor including light emitting cells may be, for example, a sapphire substrate, but is not limited thereto, and may be a bonding substrate bonded to a nitride semiconductor grown from the growth substrate. A sapphire substrate may be used as the bonding substrate.

The wires 37a electrically connect the first terminal and the second terminal of the light emitting cells 30, and the wire 37b electrically connects the four light emitting cells 30 in sequence, and the wires 37c. ) Electrically connects the bonding pads 41 and 43 to the light emitting cells 30. The bonding pads 41 and 43 are respectively connected to the first terminal and the second terminal of at least two light emitting cells through the wires 37c. The bonding pads 41 and 43 may be formed in the same shape, but are not limited thereto and may be formed in different shapes. The bonding pads 41 and 43 may be formed on the substrate 21, but may also be formed on the first conductive semiconductor layer 25 or the second conductive semiconductor layer 29.

Both ends of the wiring 37b are electrically connected to first terminals of two light emitting cells, and second terminals of two other light emitting cells 30a and 30b positioned between the two light emitting cells. Are electrically connected to the wiring 37b. Alternatively, both ends of the wiring 37b are electrically connected to the second terminals of the two light emitting cells, and the first terminals of the other two light emitting cells positioned between the two light emitting cells are connected to the wires. It may be electrically connected to 37b. For example, if all polarities of the light emitting cells of FIG. 1 are changed, an arrangement in which second terminals of two light emitting cells are connected to both ends of the wiring 37b may be obtained.

The light emitting cells 30 may be formed to have the same area, but may have different areas. The light emitting cells 30 each include a first conductive semiconductor layer 25, an active layer, and a second conductive semiconductor layer. When the first conductivity type is n-type, the second conductivity-type semiconductor layer is p-type, and at this time, the transparent electrode layer 33 may be disposed on the second conductivity-type semiconductor layer. The structure and wiring 37b of the light emitting cell will be described in detail with reference to FIGS. 2 and 3.

2 is a cross-sectional view taken along the line A-A of FIG. 1 to illustrate a light emitting diode according to an embodiment of the present invention.

Referring to FIG. 2, four light emitting cells 30 are shown on the substrate 21. The light emitting cells 30 are spaced apart from each other. Each of the light emitting cells includes a first conductive semiconductor layer 25, an active layer 27, and a second conductive semiconductor layer 29. The active layer 27 may be a single quantum well structure or a multi quantum well structure, and its material and composition are selected according to the emission wavelength required. For example, the active layer may be formed of an AlInGaN-based compound semiconductor, such as InGaN. Meanwhile, the first and second conductivity-type semiconductor layers 25 and 29 include an AlInGaN-based compound semiconductor, eg, GaN, having a larger band gap than the active layer 27.

Meanwhile, a buffer layer (not shown) may be interposed between the first conductivity type semiconductor layer 25 and the substrate 21. The buffer layer is employed to mitigate lattice mismatch between the substrate 21 and the first conductive semiconductor layer 25 when the first conductive semiconductor layer 25 is grown on the substrate 21.

As shown in the drawing, the second conductivity-type semiconductor layer 29 is positioned above a portion of the first conductivity-type semiconductor layer 25, and the active layer 27 is the first conductivity-type semiconductor layer 27. And the second conductive semiconductor layer 29 are interposed. In addition, the transparent electrode layer 33 may be positioned on the second conductive semiconductor layer 29. The transparent electrode layer 33 may be formed of an indium tin oxide (ITO) material or Ni / Au.

On the other hand, the wiring 37b is formed along the edge of the substrate 21 to electrically connect the four light emitting cells 30. The wires 37b are sequentially connected across the upper portions of the light emitting cells 30, and are electrically connected to second terminals of two light emitting cells, for example, first conductive semiconductor layers 25. The first terminals of the other two light emitting cells, for example, the second conductive semiconductor layers 29 or the transparent electrode layers 33 are electrically connected to each other. As shown, both ends of the wiring 37b are respectively connected to the first terminals of the two light emitting cells, and the wiring 37b is connected to the other two light emitting cells positioned between the two light emitting cells. Are electrically connected to the second terminals of the wires 30a and 30b.

The wirings 37a, 37b, and 37c are formed on the first insulating layer 35 to be insulated from the sidewalls of the light emitting cells 30. The first insulating layer 35 is formed of a silicon oxide film or a silicon nitride film. In addition, the wires may be covered with a second insulating layer 39. The second insulating layer 35 covers the wirings and the light emitting cells to protect the wirings and the light emitting cells from external force or moisture. The second insulating layer 39 may be formed of a silicon oxide film or a silicon nitride film, and may be formed of the same material as the first insulating layer 37 to increase adhesion. On the other hand, when the first insulating layer 37 is thin, an electrical short may occur between the wirings and the light emitting cells, and in particular, when driven under a high voltage AC power supply, insulation breakdown may occur. Therefore, the first insulating layer 37 is preferably thicker than the second insulating layer 39.

The light emitting cells may be arranged in a matrix form on the single substrate 21 by the wiring 37b, and the light emitting cells may be arranged such that light emitting cells alternately emit light in rows. In addition, the wiring 37b may be used to measure electrical characteristics of an array of light emitting cells in a row during a light emitting diode manufacturing process. That is, in FIG. 1, the electrical characteristics of the light emitting cells in a row unit may be measured by applying a voltage or a current to the bonding pad 41 or 43 and the wiring 37b. This measurement helps to locate electrical defects within the light emitting cells.

3 is a cross-sectional view for describing a light emitting diode according to still another embodiment of the present invention.

Referring to FIG. 3, substantially the same as described with reference to FIG. 2, except that the first conductivity type semiconductor layers of two other light emitting cells positioned between two light emitting cells connected to both ends of the wiring 37b. (25) are different from each other. That is, the other two light emitting cells 30a and 30b of FIG. 1 are connected to the first conductive semiconductor layers 25 without being separated from each other. Meanwhile, the second conductive semiconductor layers 29 are separated from each other.

As the first conductive semiconductor layers 25 of the light emitting cells 30a and 30b are connected to each other, the separation region between the light emitting cells 30a and 30b disappears, thus reducing the stepped area. As a result, the wiring 37b can be easily formed, and the reliability of the wiring is improved.

4 is a partial cross-sectional view for describing light emitting cells according to example embodiments.

2 and 3, the first conductive semiconductor layer 25 of each light emitting cell has a single inclined surface. This inclined surface helps the wiring to be formed safely. However, when the first conductive semiconductor layer 25, which is relatively thicker than the active layer 27 and the second conductive semiconductor layer 29, has an inclined surface, the width of the lower region of the light emitting cell increases considerably according to the inclination of the inclined surface. do. Therefore, the single inclined surface of the first conductivity type semiconductor layer 25 may prevent the high integration of the light emitting cells on the substrate having a limited area.

As illustrated in FIG. 4, the first conductive semiconductor layer 25 of each light emitting cell may be shaped to have a first inclined surface 25a and a second inclined surface 25b. The second inclined surface 25b is located closer to the substrate 21 than the first inclined surface 25a. The first inclined surface 25a and the second inclined surface 25b have different inclinations with respect to the surface of the substrate 21. For example, as shown in FIG. 4, the second inclined surface 25b has a sharp inclination relative to the first inclined surface 25a, or the first inclined surface 25a is relative to the second inclined surface 25b. It can have a steep slope. Accordingly, the first conductive semiconductor layer 25 may provide a light emitting cell having a relatively reduced width compared to a light emitting cell having a single gentle inclined plane, that is, only the first inclined plane 25a of FIG. 4. As a result, a larger number of light emitting cells can be integrated in a limited area. Moreover, the wiring can be more easily formed by the inclined surfaces having different inclinations.

Meanwhile, the first conductivity type semiconductor layer 25 may not only represent a single layer but may be a multilayer, and as the person skilled in the art is well aware of, the undoped semiconductor layer may be included in the multilayer. In addition, a buffer layer (not shown) may be interposed between the substrate 21 and the second conductivity-type semiconductor layer 25.

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

Referring to FIG. 5, it is generally similar to the light emitting diode described with reference to FIG. 1, except that the light emitting cells are arranged in six rows. In this case, the bonding pads 41 and 43 may be disposed in a diagonal direction, and in addition to the wiring 37b connecting four light emitting cells, a wiring 57b connecting four other light emitting cells may be formed. have.

Like the wiring 37b described with reference to FIG. 1, the wiring 57b is also electrically connected to four light emitting cells in turn, and the second terminals of the two light emitting cells and the other two light emitting cells. Are connected to the first terminals of the terminals. Both ends of the wiring 57b are connected to the first terminals of the two light emitting cells, and the second terminals of the other two light emitting cells 50a and 50b positioned between the two light emitting cells are connected to the wiring 57b. ) Can be connected. In this case, the first conductivity-type semiconductor layers 25 of the light emitting cells 50a and 50b may be connected to each other.

On the other hand, both ends of the wiring 57b are connected to the second terminals of the two light emitting cells, and the first terminals of the other two light emitting cells 50a and 50b positioned between the two light emitting cells are It may be connected to the wiring 57b. In this case, the order of the four light emitting cells connected to the wiring 37b and the four light emitting cells connected to the wiring 57b are reversed. For example, when a row is formed of an odd number of light emitting cells by increasing the number of light emitting cells in a row, the order of the light emitting cells connected to the wiring 37b and the wiring 57b is configured to be reversed. In this case, the first conductive semiconductor layers 25 of the other two light emitting cells 50a and 50b positioned between the two light emitting cells connected to both ends of the wiring 57b are separated from each other.

The wiring 37b and the wiring 57b are disposed along both edges of the substrate 21, respectively, and are disposed in diagonal directions with each other. Accordingly, the light emitting cells can be arranged in a matrix shape, and the light emitting cells can be arranged so that the light emitting cells alternately emit light in rows.

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

Referring to FIG. 6, it is generally similar to the light emitting diode described with reference to FIG. 5 except that the shape of the bonding pads 51 and 53 is different from the bonding pads 41 and 43 of FIG. 5. That is, the bonding pads 41 and 43 include a portion having a large area and a portion extending therefrom, and the bonding pads 51 and 53 have a rectangular shape. The shape of the bonding pads 51 and 53 is not particularly limited and may be variously modified according to the size and arrangement of the light emitting cells. In particular, the bonding pads 51 and 53 are preferably located in an area in which the light emitting cells 30 are arranged.

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

Referring to FIG. 7, it is generally similar to the light emitting diode described with reference to FIG. 5 except that bonding pads 61 and 63 are formed on the light emitting cells 30. That is, the bonding pads 61 and 63 are formed on the first terminal and the second terminal of the two light emitting cells 30 and are electrically connected thereto. Therefore, the wirings 37c connecting the bonding pads and the light emitting cells may be omitted.

8 is a plan view illustrating a light emitting diode according to still another embodiment of the present invention, and FIG. 9 is a schematic equivalent circuit diagram of the light emitting diode of FIG. 8.

8 and 9, the light emitting diode includes a substrate 21, bonding pads 71 and 73, a plurality of half-wave light emitting cells 30, a plurality of propagating light emitting cells 70 and wires ( 37b, 37c, 77b, 77e, 77d). Here, the half-wave light emitting cell refers to a light emitting cell to which the forward voltage is applied during the half cycle of the AC power, and the full-wave light emitting cell refers to a light emitting cell to which the forward voltage is applied during the full cycle of the AC power.

The substrate 21 and the half-wave light emitting cells 30 are similar to those described with reference to FIGS. 1 and 2. However, in one row, the light emitting cells 30 are disposed to face each other. That is, the light emitting cells 30c and 30d face each other with the first terminals or face the second terminals.

On the other hand, each of the full-wave light emitting cells 70 is disposed between the rows of the light emitting cells 30, the third terminal and the fourth terminal corresponding to the first terminal and the second terminal of the half-wave light emitting cell 30, respectively Has The fourth terminal of the full-wave light emitting cell 70 is electrically connected to the first terminals of the two half-wave light emitting cells 30 through the wiring 77d, and the third terminal thereof is connected through the wiring 77e. The second terminals of the two half-wave light emitting cells 30 are electrically connected to each other. In addition, a half-wave light emitting cell 30 is disposed in a forward direction between the third terminal of one full-wave light emitting cell 70 and the fourth terminal of the full-wave light emitting cell 70 adjacent thereto, and the single full-wave light emitting cell 70 is disposed. The half-wave light emitting cell 30 is disposed in the forward direction between the fourth terminal of and the third terminal of the radio wave emitting cell adjacent thereto.

Accordingly, when AC power is connected to the bonding pads 71 and 73, the half-wave light emitting cells 30 are alternately driven, and the full-wave light emitting cells 70 are provided during the full cycle. Therefore, the use efficiency of the light emitting cells driven on the single substrate 21 can be improved. In addition, the reverse voltage applied to the half-wave light emitting cell 30 during the half cycle can be adjusted relatively low.

8 and 9, one propagation light emitting cell 70 is disposed between rows of half-wave light emitting cells, but a plurality of propagation light emitting cells 70 are arranged between rows of half-wave light emitting cells in an array form. May be In addition, a plurality of half-wave light emitting cells may be arranged in an array form between adjacent propagating light emitting cells 70. However, the number of these propagation light emitting cells or half-wave light emitting cells in an array form is limited in consideration of the reverse voltage applied to the half-wave light emitting cells.

On the other hand, as the light emitting cells 30 are disposed to face each other, the wirings 77d and 77e electrically connect one full wave light emitting cell 70 and two half wave light emitting cells 30 without being branched, respectively. It is possible to connect, thus improving the stability of the wiring.

Meanwhile, as described with reference to FIGS. 1 and 2, the wiring 37b electrically connects four light emitting cells. In addition, the wiring 77b is disposed diagonally to the wiring 37b to electrically connect four light emitting cells. Both ends of the wiring 77b are connected to the second terminals of the two half-wave light emitting cells, and the first terminals of the other two half-wave light emitting cells 70a and 70b disposed between the two light emitting cells. It is connected to the wiring 77b. Alternatively, the wiring 77b is also connected to the first terminals of the two half-wave light emitting cells, like the wiring 37b, and two other half-wave light emitting cells 70a disposed between the light emitting cells. The second terminals of 70b may be connected to the wiring 77b. By controlling the number of half-wave light emitting cells arranged in one row, the wiring 37b and the wiring 77b connect the half-wave light emitting cells in the same order or connect them in different orders.

In the present embodiment, the bonding pads 71 and 73 are illustrated as being positioned between the uppermost row and the lowermost row of the half-wave light emitting cells. have. In addition, the bonding pads 71 and 73 may be formed on the two half-wave light emitting cells 30, and thus the wirings 37c may be omitted.

10 is a plan view illustrating a light emitting diode according to still another embodiment of the present invention. The equivalent circuit of the light emitting diode according to this embodiment is the same as that of FIG.

Referring to FIG. 10, the first conductive semiconductor layers 25 of the light emitting cells 30c and 30d are substantially similar to the light emitting diodes described with reference to FIG. 8, but the second terminals face each other in FIG. 8. There is a difference in this connection. The first conductive semiconductor layers 25 of the half-wave light emitting cells 30a and 30b connected to the wiring 37b may also be connected to each other.

Accordingly, the steps formed to separate the light emitting cells 30 can be reduced, so that the wirings 37b, 77d, and 77e can be easily formed, and their reliability can be improved.

11 is a plan view illustrating a light emitting diode according to still another embodiment of the present invention. The equivalent circuit of the light emitting diode according to this embodiment is the same as that of FIG.

Referring to FIG. 11, the light emitting diode includes a substrate 21, bonding pads 91 and 93, a plurality of half-wave light emitting cells 30, a plurality of propagating light emitting cells 80 and wires 37b and 77b. , 87e, 87d).

The substrate 21 and the half-wave light emitting cells 30 are similar to those described with reference to FIGS. 1 and 2. However, in one row, the light emitting cells 30 are disposed to face each other. That is, the light emitting cells 30c and 30d face each other with the first terminals or face the second terminals.

Meanwhile, the propagation light emitting cells 80 are disposed between the half wave light emitting cells 30 facing each other, and are disposed over two rows of the half wave light emitting cells 30. Each of the full-wave light emitting cells 80 has its fourth terminal electrically connected to the first terminals of the two half-wave light emitting cells 30 through a wiring 87d, and its third terminal has a wiring 87e. ) Is electrically connected to the second terminals of the two half-wave light emitting cells 30. The wires 87d and 87e sequentially connect two half-wave light emitting cells 30 and one full wave light emitting cell 80. In addition, a half-wave light emitting cell 30 is disposed in a forward direction between the third terminal of one full-wave light emitting cell 80 and the fourth terminal of the full-wave light emitting cell 80 adjacent thereto, and the single full-wave light emitting cell 80 is disposed. The half-wave light emitting cell 30 is disposed in the forward direction between the fourth terminal of and the third terminal of the radio wave emitting cell adjacent thereto.

Accordingly, a light emitting diode having an equivalent circuit as shown in FIG. 9 may be provided.

In the present embodiment, one full-wave light emitting cell 80 is illustrated as being disposed between half-wave light emitting cells, but a plurality of full-wave light emitting cells 80 may be arranged between the half-wave light emitting cells in an array form. . In addition, a plurality of half-wave light emitting cells may be arranged in an array form between adjacent propagation light emitting cells 80. However, the number of these propagation light emitting cells or half-wave light emitting cells in an array form is limited in consideration of the reverse voltage applied to the half-wave light emitting cells.

On the other hand, the wiring 37b and the wiring 77b electrically connect the four light emitting cells as described with reference to FIG. 8.

In this embodiment, the bonding pads 91 and 93 are formed on the two half-wave light emitting cells 30 and electrically connected thereto, so that the wirings 37c of FIG. 8 are omitted.

12 and 13 are an equivalent circuit diagram and a plan view for explaining a light emitting diode according to another embodiment of the present invention, respectively.

12 and 13, in the light emitting diode according to the present embodiment, half-wave light emitting cells are arranged in four rows between the bonding pads 71 and 73 as compared with the light emitting diode described with reference to FIG. 9. , Two rows of propagation light emitting cells are arranged between two rows of half wave light emitting cells, respectively.

Meanwhile, in the equivalent circuit diagram of FIG. 9, two rows of half-wave light emitting cells arranged on the upper side and two rows of half-wave light emitting cells arranged on the bottom are electrically connected to each other by the wiring 37b. In this arrangement, the half-wave light emitting cell 30d located at the right end of the first row and the half-wave light emitting cell 30a located at the right end of the second row are positioned at the right end of the third row through the wiring 37b. The half wave light emitting cell 30b and the half wave light emitting cell 30d positioned at the right end of the fourth row are directly connected to each other.

On the contrary, the light emitting diode according to the present embodiment has an additional propagation light emitting cell between the half wave light emitting cell 30d positioned at the right end of the first row and the half wave light emitting cell 30a positioned at the right end of the first row. 70a) is further included. In addition, the second terminal of the half-wave light emitting cell 30a at the right end of the second row and the half-wave light emitting cell 30b at the right end of the third row are electrically connected to each other, and the right side of the first row is The half wave light emitting cell 30d located at the end and the half wave light emitting cell 30d located at the right end of the fourth row are connected through the wiring 97b. The half wave light emitting cells 30a and 30b are connected to the half wave light emitting cells 30d in the first row and the fourth row through the radio wave emitting cell 70a.

Therefore, according to the present embodiment, there is provided a light emitting diode which is repeated in the same basic structure so that the forward current alternately flows through the half-wave light emitting cell and the light emitting light emitting cell, and the number of the light emitting cell is increased in comparison with the previous embodiments. You can.

On the other hand, the position of the additional propagation light emitting cells 70a is not particularly limited, and as shown in FIG. 13, disposed in parallel with the rows of the top propagation light emitting cells 70 or the lower propagation light emitting cells 70. Can be placed next to each other. Further, the additional propagation light emitting cell 70a may be disposed to the right of the region between the second row of half-wave light emitting cells and the third row of half-wave light emitting cells, as shown in FIG. 14.

In addition, as shown in FIG. 13, the first terminal of the half-wave light emitting cell located at the right end of the first row and the first terminal of the half-wave light emitting cell located at the right end of the fourth row provide wiring 97b. Although not limited thereto, the second terminal of the half-wave light emitting cells positioned at the right end of the first row and the half-wave light emitting positioned at the right end of the fourth row may vary according to the number of half-wave light emitting cells in each row. The second terminal of the cell may be connected via the wiring 97b.

15 and 16 are an equivalent circuit diagram and a plan view for explaining a light emitting diode according to another embodiment of the present invention.

15 and 16, in the light emitting diode according to the present exemplary embodiment, half-wavelength light emitting cells are arranged in six rows between bonding pads 71 and 73 similarly to the light emitting diode described with reference to FIG. 9. , Three rows of propagation light emitting cells are arranged between two rows of half wave light emitting cells, respectively. In addition, as described with reference to FIGS. 12 and 13, the additional propagation light emitting cell 70a is formed at the right end of the first row and the second row of the half-wave light emitting cells and the third row and the fourth row of the half-wave light emitting cells. Used to connect the right end.

Further, an additional propagation light emitting cell 70b is used to connect the left end of the third and fourth rows of half-wave light emitting cells and the right end of the fifth and sixth rows of half-wave light emitting cells.

By using the additional propagation light emitting cells 70a and 70b, it is possible to provide a light emitting diode in which the same basic structure is repeated even if the light emitting cells are arranged in more rows.

17 illustrates plan views for explaining shapes of various light emitting cells and various electrode arrangements that may be used in light emitting diodes according to embodiments of the present invention. Here, although the electrodes are shown as connected to the wires, the wires and the electrodes may be formed together by the same process.

Referring to FIG. 17A, electrodes, for example, an n-electrode and a p-electrode, are formed on the first conductive lower semiconductor layer and the second conductive upper semiconductor layer of the light emitting cell, respectively. It includes an extension that extends from the portion to which the wiring is connected. The extension of the n-electrode and the extension of the p-electrode are formed symmetrically with each other and may be formed in parallel with each other. The wirings may be connected to the central portion of the corresponding electrode, respectively.

Referring to FIG. 17B, electrodes (n-electrode and p-electrode) are formed on the first conductive lower semiconductor layer and the second conductive upper semiconductor layer of the light emitting cell, respectively. An electrode, eg, a p-electrode, formed on the semiconductor layer may be formed in the center portion on the light emitting region. The electrodes may be formed to include extensions, as described with reference to FIG. 17A.

Referring to FIG. 17C, the wirings are substantially similar to those of FIG. 17A, but the wirings are connected to the electrodes near the edges of the first conductive lower semiconductor layer and the second conductive lower semiconductor layer, respectively. The wirings are connected to the electrodes at a diagonally symmetrical portion of the light emitting cell, and the electrodes each have extensions extending along the edge of the light emitting cell at the portion where the wirings are connected. The extensions can be formed parallel to one another, so that the distance between the extensions can be substantially the same.

Referring to FIG. 17D, electrodes are formed on the first conductive lower semiconductor layer and the second conductive upper semiconductor layer of the light emitting cell, and the electrodes are positioned in symmetry with respect to each other in a diagonal. 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- and p-electrodes may be parallel to each other. In addition, the symmetrical, positioned on the diagonal of the light emitting cell in a symmetrical form with each other.

Referring to FIG. 17E, 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, when the light emitting region has a rectangular shape, the n-electrode may have a triangular shape. In contrast, when the light emitting region has a trapezoidal shape, the p-electrode may have a triangular shape.

Referring to FIG. 17F, the wirings may be connected to the electrodes on the same side of the light emitting cell. The electrodes may have extensions extending along edges of the first conductivity type lower semiconductor layer and the second conductivity type upper semiconductor layer from the portions to which the wirings are connected. These extensions can be parallel to each other.

Referring to FIG. 17G, the wirings may be connected to the electrodes at opposite sides of the light emitting cell. The electrodes may have extensions extending along edges of the first conductivity type lower semiconductor layer and the second conductivity type upper semiconductor layer from the portions to which the wirings are connected. These extensions can be parallel to each other.

Referring to FIG. 17H, the light emitting cells may have a parallelogram shape. The electrodes may each have a plurality of extensions extending near the edges, each of which may extend along the edge of the light emitting cell. In addition, corresponding extensions of the n-electrode and the p-electrode may be formed parallel to each other.

In the above, although the structure of the light emitting cells and the connection of the light emitting cells through the wiring has been described schematically, various modifications may be made to the structure and the wiring of the light emitting cells, and the present invention provides a structure of a specific light emitting cell and a specific wiring structure. It is not limited to.

While some embodiments of the present invention have been described above by way of example, those skilled in the art will appreciate that various modifications and variations can be made without departing from the essential features of the present invention. Therefore, the embodiments described above should not be construed as limiting the technical spirit of the present invention but merely for better understanding. The scope of the present invention is not limited by these embodiments, and should be interpreted by the following claims, and the technical spirit within the scope equivalent thereto should be interpreted as being included in the scope of the present invention.

1 is a plan view illustrating a light emitting diode according to an exemplary embodiment of the present invention.

2 is a cross-sectional view taken along the line A-A of FIG. 1 to illustrate a light emitting diode according to an embodiment of the present invention.

3 is a cross-sectional view for describing a light emitting diode according to still another embodiment of the present invention.

4 is a partial cross-sectional view illustrating a light emitting cell according to embodiments of the present invention.

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

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

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

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

9 is an equivalent circuit diagram of the light emitting diode of FIG. 8.

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

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

12 and 13 are an equivalent circuit diagram and a plan view for explaining a light emitting diode according to another embodiment of the present invention, respectively.

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

15 and 16 are an equivalent circuit diagram and a plan view for explaining a light emitting diode according to another embodiment of the present invention.

17 is a plan view illustrating various shapes and various electrode arrangements of light emitting cells used in light emitting diodes according to embodiments of the present disclosure.

Claims (19)

It includes a plurality of light emitting cells formed on the substrate, The plurality of light emitting cells includes a first insulating layer including an opening exposing a first conductive semiconductor layer and a second conductive semiconductor layer thereon. Wires electrically connecting the light emitting cells through the openings of the first insulating layer; At least one of the wires electrically connects at least four light emitting cells, and the light emitting diode electrically connects the first conductive semiconductor layer of the two light emitting cells and the second conductive semiconductor layer of the other two light emitting cells. . The method according to claim 1, The two light emitting cells are disposed between the other two light emitting cells. The method according to claim 2, The two light emitting cells share a first conductivity type semiconductor layer with each other. The method according to claim 1, The sidewalls of the first conductive semiconductor layer and the second conductive semiconductor layer are inclined. The method according to claim 4, The inclination of the side wall is a light emitting diode, characterized in that formed in twofold. The method according to claim 5, The inclined double formed light emitting diode, characterized in that divided in the first semiconductor layer. The method according to claim 1, And a second insulating layer covering the wirings. The method of claim 7, Wherein the first insulating layer is thicker than the second insulating layer. The method according to claim 1, The plurality of light emitting cells comprises at least one full-wave light emitting cell and at least one half-wave light emitting cell. The method according to claim 9, The wires include at least one wire electrically connecting the second semiconductor layer of one full-wave light emitting cell to the first semiconductor layer of two half-wave light emitting cells. The method according to claim 10, The two half-wave light emitting cells share a first conductivity type semiconductor layer with each other. The method according to claim 10, And the wires include at least one wire electrically connecting the first semiconductor layer of one full-wave light emitting cell to the second semiconductor layer of two half-wave light emitting cells. The method according to claim 1, And the at least one wire is disposed along an edge of the substrate. 14. The method of claim 13, The at least one wire is formed along the edge of one side of the substrate and is disposed adjacent to the first corner of the substrate edge, The other wiring is formed along the edge of the other side of the substrate and is disposed adjacent to the second corner which is opposite to the first one of the substrate edges in the opposite direction, Light emitting diodes, characterized in that one side and the other side of the substrate facing each other. The method according to claim 1, Each of the plurality of light emitting cells includes 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 according to claim 15, 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, and an extension extending from the n-electrode and an extension extending from the p-electrode are symmetrical to each other. Light emitting diodes, characterized in that. 18. The method of claim 16, And an extension extending from the n-electrode and an extension extending from the p-electrode are parallel to each other. 18. The method of claim 16, And the extension portion extending from the n-electrode and the extension portion extending from the p-electrode are symmetric with each other on a diagonal line of the light emitting cell. 18. The method of claim 16, And the plurality of light emitting cells are substantially equal in distance between an extension extending from an n-electrode and an extension extending from the p-electrode.

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