KR101361109B1 - Ac driving light emitting device - Google Patents

Abstract

An AC drive light emitting device according to the present invention includes a substrate, K first LED cells (where K is an integer of 3 or less) arranged in a line on the substrate, and the first LED cell on the substrate. AC driving light emitting device comprising K second LED cells arranged in a row in parallel with a row, and K-1 third LED cells arranged in a row between the rows of the first and second LED cells on an upper surface of the substrate. To provide.
The AC drive light emitting device has a connection structure between LED cells that can be driven by AC. In the connection structure between the LED cells according to the present embodiment, when defining in the order of the first to third LED cells in a specific arrangement direction, the m-th (where m is an odd number smaller than K) third of the third LED cell. The first electrode is connected to the second electrode of the m th and m + 1 first LED cells, and the second electrode of the m th third LED cell is connected to the first electrode of the m th and m + 1 second LED cells do. The first electrode of the nth (where n is an even number less than K) third LED cell is connected to the second electrode of the nth and n + 1th second LED cells, and the second of the nth third LED cell The electrode is connected to the first electrode of the nth and n + 1th first LED cells.

Description

AC drive light emitting device {AC DRIVING LIGHT EMITTING DEVICE}

The present invention relates to an AC drive light emitting device, and more particularly, to an AC drive light emitting device that can be used directly from an AC power source without a conversion device for converting to a DC power source.

Semiconductor light emitting diodes (LEDs) have advantageous advantages as light sources in terms of output, efficiency, and reliability, and thus are actively researched and developed as high power and high efficiency light sources that can replace backlights of lighting devices or display devices.

In general, light emitting diodes are driven at low direct currents. Therefore, in order to drive the light emitting diode at a regular voltage (eg, AC 220V), an additional circuit (eg, AC / DC converter) for supplying a low DC output voltage is required. However, the introduction of such an additional circuit not only complicates the configuration of the LED module, but may also cause a decrease in efficiency and reliability in the conversion of the power supply. In addition, due to additional components other than the light source, the product price increases, the size of the product increases, and the EMI characteristic is deteriorated by the periodic component during the switching mode operation.

In order to solve this problem, various types of LED driving circuits capable of driving AC voltage without additional converters have been proposed. In general, however, in the AC driven LED driving circuit, since most of the LEDs are arranged to be driven only at a specific half cycle of the AC voltage, the number of LEDs required to obtain a desired amount of light is greatly increased.

The required number of such LEDs may vary depending on the arrangement of the LEDs even if they provide the same amount of light, but have a very low efficiency in a conventional arrangement. For example, in the case of the conventional representative anti-parallel arrangement or bridge arrangement, the number of LEDs that are actually continuously emitted is only about 50% and 60% of the total number of LEDs, respectively. That is, there is an inefficient problem in that the number of LEDs consumed to obtain a desired light emission level increases.

Therefore, the same amount of light can be provided using fewer LEDs through a more efficient arrangement of LEDs, which is a very important problem in terms of economics of manufacturing and selling AC driven LED circuits.

In addition, in actual implementation of the AC driving light emitting device, the connection of each unit LED cell may generally have a complicated aspect. Therefore, there may be a problem that the wiring connection form and the process of forming the same are complicated and have low mass productivity. In addition, since a large number of LED cells have a complicated connection, it is also recognized as an important problem to design a miniaturized form to have a high degree of integration.

SUMMARY OF THE INVENTION The present invention has been made to solve the above technical problem, and an object thereof is to provide an excellent AC-driven light emitting device having a high degree of integration by optimizing the connection and arrangement of each LED cell while having a connection structure capable of driving at AC. .

In order to solve the above technical problem, an embodiment of the present invention,

A substrate, K first LED cells (where K is an integer of 3 or less) arranged in a row on the substrate, and K articles arranged in a row in parallel with a row of the first LED cells on the substrate Provided are an AC drive light emitting device comprising two LED cells and K-1 third LED cells arranged in a row between the rows of the first and second LED cells on an upper surface of the substrate.

The AC drive light emitting device has a connection structure between LED cells that can be driven by AC.

In the connection structure between the LED cells according to the present embodiment, when defining in the order of the first to third LED cells in a specific arrangement direction, the m-th (where m is an odd number smaller than K) third of the third LED cell. The first electrode is connected to the second electrode of the m th and m + 1 first LED cells, and the second electrode of the m th third LED cell is connected to the first electrode of the m th and m + 1 second LED cells do.

The first electrode of the nth (where n is an even number less than K) third LED cell is connected to the second electrode of the nth and n + 1th second LED cells, and the second of the nth third LED cell The electrode is connected to the first electrode of the nth and n + 1th first LED cells.

In addition, the AC driving light emitting device according to the present embodiment includes a first external electrode connected to the first electrode of the first first LED cell and the second electrode of the first second LED cell, and the K-th first and second LEDs. The cell further includes a second external electrode connected to an electrode not connected to the third LED cell.

Preferably, the first and second electrodes of the first to third LED cells are positioned adjacent to opposite sides of the cell upper surface, respectively, and may have portions extending along the corresponding sides. As a result, a higher current efficiency can be expected by achieving a uniform current distribution over the entire light emitting area of each LED cell.

The upper surface of the substrate may be a rectangle consisting of the first to fourth sides. In this case, the first and second LED cells are arranged side by side along the first and second sides, respectively, and the first and second LED cells are adjacent to the third side, and the Kth The first and second LED cells of may be arranged to be adjacent to the fourth side.

Preferably, in order to realize a high degree of integration, the third LED cell may be arranged to be adjacent to two first LED cells to which an electrode is connected and two second LED cells to which an electrode is connected.

In a particular embodiment, the third LED cells may be provided in a form having a top surface each of which is parallelogram inclined in the arrangement direction.

In this embodiment, in order to shorten the electrode wiring connection and reduce the defects, the first and second electrodes of the third LED cell are formed adjacent to both sides inclined on the upper surface of the third LED cell, respectively. desirable.

Further, in this case, the first and second electrodes of the first LED cell are respectively formed on the upper surface of the first LED cell so as to be adjacent to both sides perpendicular to the arrangement direction of the first LED cell, the second LED Preferably, the first and second electrodes of the cell are formed to be adjacent to both sides perpendicular to the arrangement direction of the second LED cell on the upper surface of the second LED cell.

Alternatively, in another embodiment, the third LED cell may have a shape having an almost rectangular top surface composed of two opposing long sides and two opposing short sides.

In the present embodiment, the first and second electrodes of the third LED cell may be formed to be adjacent to two long sides of the rectangular upper surface, respectively.

In this case, the third LED cell is arranged such that its long side is substantially perpendicular to the arrangement direction of the third LED cell, and the first and second electrodes of the first LED cell are respectively on the top surface of the first LED cell. Are formed to be adjacent to both sides parallel to the array direction of the first LED cell, and the first and second electrodes of the second LED cell are respectively parallel to the array direction of the second LED cell on the upper surface of the second LED cell. It is preferably formed adjacent to both sides of the phosphorus.

Further, in order to realize external electrode connection with the first and second LED cells so as to satisfy a high degree of integration, the first first LED cell may be configured along the third side of the upper surface of the substrate. Extending to be adjacent to the cell, the second K-th LED cell may be formed to extend adjacent to the first K-th LED cell along the fourth side of the upper surface of the substrate.

In this case, the first and second external electrodes can be located on the extended LED cell. That is, the first external electrode may be positioned on the first first LED cell, and the second external electrode may be positioned on the K-th second LED cell.

Preferably, in order to prevent the voltage from being concentrated in a specific cell, the first to third LED cells may have almost the same light emitting area.

Preferably, the first to third LED cells of the AC drive light emitting device may be obtained from a first conductive semiconductor layer, an active layer and a second conductive semiconductor layer sequentially grown on the substrate. That is, by separating the first conductive semiconductor layer, the active layer and the second conductive semiconductor layer for the light emitting structure grown on the entire upper surface of the substrate by each cell unit through a suitable separation process, the desired arrangement of the first to third LED cells is achieved. You can get it.

Such a separation process may be classified into a full-isolation process that exposes the substrate to a substrate or a half-isolation process that exposes only the first conductive semiconductor layer, depending on the connection form between the LED cells.

For example, at least one pair of the m th second LED cell and the m + 1 th second LED cell may be separated from each other by an area (semi-separation process) in which the first conductive semiconductor layer is exposed. One first electrode formed in the exposed region of the first conductivity type semiconductor layer may be shared.

Similarly, at least one pair of the n th first LED cell and the n + 1 th first LED cell is also separated from each other by an exposed region of the first conductivity type semiconductor layer, One first electrode formed in the exposed area may be shared.

In this way, by applying a semi-separation process to a particular cell and configured to share the first electrode, the process can be simplified and the degree of integration can be further improved.

In a preferred example, all pairs of the m th second LED cell and the m + 1 th second LED cell are separated from each other by an area where the first conductivity type semiconductor layer is exposed and the exposed portion of the first conductivity type semiconductor layer is exposed. All pairs of n th first LED cells and n + 1 th first LED cells sharing one first electrode formed in an area are separated from each other by an area where the first conductivity type semiconductor layer is exposed. One first electrode formed in the exposed region of the first conductivity type semiconductor layer may be shared, and the other adjacent first to third LED cells may be separated by the region (complete separation process) exposed to the substrate.

Alternatively, all of the first to third LED cells may be separated from other adjacent LED cells by a region (complete separation process) exposed to the substrate.

An AC drive light emitting device according to a preferred embodiment of the present invention includes a substrate and at least first and second ladder network LED arrays formed side by side on the substrate. Here, each of the first and second ladder network circuit type LED array, K first LED cells (where K is an integer less than or equal to 3) arranged in a line on the upper surface of the substrate and the first surface on the substrate And K second LED cells arranged in a row parallel to a row of one LED cell, and K-1 third LED cells arranged in a row between the rows of the first and second LED cells on an upper surface of the substrate. .

The first and second ladder networked LED arrays are arranged such that the columns of each second LED cell are adjacent.

In addition, in the case of the connection form of each LED cell in each said ladder network type LED array, when defining the order of the said 1st-3rd LED cell in a specific arrangement direction, mth (where m is less than K) Small odd number) The first electrode of the third LED cell is connected to the second electrode of the m th and m + 1 th first LED cells, and the second electrode of the m th third LED cell is the m th and m + 1 th A first electrode of the nth (where n is an even number less than K) third electrode connected to the first electrode of the second LED cell, the first electrode of the nth and n + 1th second LED cells And a second electrode of the n th third LED cell is connected to a first electrode of the n th and n + 1 th first LED cells.

The first electrode of the first first LED cell and the second electrode of the first second LED cell are connected to each other, and the electrodes of the K-th first and second LED cells that are not connected to the third LED cell are connected to each other. do.

In addition, the AC drive light emitting device of the present embodiment includes the second K-th LED cell and the second ladder of the first ladder network circuit-type LED array for connection between the first and second ladder network circuit-type LED arrays. The electrodes not connected to the third LED cell of the K-th second LED cell of the networked LED array are connected to each other.

Preferably, the first to third LED cells of each ladder network type LED array may include a first conductive semiconductor layer, an active layer and a second conductive semiconductor layer sequentially grown on the substrate.

If the number K of the first and second LED cells in each ladder network LED array is odd, the second K-th LED cell and the second ladder network of the first ladder network LED array The second K-th LED cell of the circuit-type LED array may be separated from each other by an area where the first conductive semiconductor layer is exposed, and may share one first electrode.

In a similar manner, at least one third ladder network LED array may be connected.

According to the present invention, there is provided an AC drive light emitting device capable of optimizing a complicated ladder network connection structure for AC driving to have a high degree of integration. In particular, it is possible to ensure the high efficiency of each LED cell, while realizing the arrangement of the LED cells to simplify the connection form between the LED cells, suggesting the electrode position and the connection method between the electrodes excellent AC drive type light emission with high mass productivity A device can be provided.

1A shows an LED driving circuit according to an embodiment (unit array) of the present invention.
FIG. 1B shows an arrangement of LED cells for implementing the light emitting device according to the circuit of FIG. 1A.
2 is a plan view showing a light emitting device according to an embodiment of the present invention.
3A to 3D are side cross-sectional views of the light emitting device shown in FIG.
4 is a plan view showing a light emitting device according to another embodiment of the present invention.
5 is a plan view showing a light emitting device according to a preferred embodiment of the present invention.
FIG. 6 shows an equivalent circuit of the light emitting device shown in FIG.
7A to 7C are plan and side cross-sectional views showing the connection portion A of the ladder network circuit row of the light emitting device shown in FIG.

Hereinafter, with reference to the accompanying drawings will be described embodiments of the present invention;

1A shows an LED driving circuit according to an embodiment (unit array) of the present invention.

In the LED driving circuit shown in FIG. 1A, three first LED cells A1, A2, and A3 connected in parallel to each other between the first and second contacts provided to the external terminals P1 and P2 are provided. Connected between two intermediate contacts between the LED cells B1, B2, B3 and each of the first LED cells A1, A2, A3 and two intermediate contacts of the second LED cells B1, B2, B3, respectively. It includes two third LED cells (C1, C2).

Looking at the connection between the electrodes of the first to third LED cells, the first electrode (-) of the first third LED cell (C1) is the second electrode of the first and second first LED cells (A1, A2) It is connected to the (+), the second electrode (+) of the first third LED cell (C1) is connected to the first electrode (-) of the first and second second LED cells (B1, B2). The first electrode (-) of the second third LED cell (C2) is connected to the second electrode (+) of the second and third second LED cells (B2, B3), and the second third LED cell (C2). The second electrode (+) of) is connected to the first electrode (−) of the second and third first LED cells A2 and A3.

In addition, a first electrode (−) of a first first LED cell A1 and a second electrode of a first second LED cell B1 are connected to the first contact, and a third first to the second contact. The second electrode (+) of the LED cell A3 and the first electrode (−) of the third second LED cell B3 are connected.

By such a connection, the LED driving circuit shown in FIG. 1A can have two current loops to be driven at different half cycles of the AC voltage.

In the first half period of the alternating voltage, the groups B 1 -C 1 -A 2 -C 2 -B 3 of the LED cells connected in series form a first current loop. In the second half period of the alternating voltage, the groups A3-C2-B2-C1-A1 connected in series form a second current loop. Through this operation, the two third LED cells C1 and C2 may be driven continuously over the entire period of the AC voltage.

In fact, it is possible to secure 5 LED elements (5/8 = 62.5% of the number of driving LEDs compared to the number of LEDs used) that continuously emit light in the ladder network. This is an improvement over conventional AC-driven LED arrays, reverse polarity arrays (50%) or bridge arrays (typically 60%).

The present invention provides a layout for implementing a ladder network LED drive circuit as illustrated in FIG. 1A. The layout of the LED cell can be implemented to simplify the connection between the electrodes with the guarantee of high integration and excellent luminous efficiency.

FIG. 1B is a schematic diagram illustrating an example of the present invention, and shows a schematic layout of an LED cell for implementing the circuit of FIG. 1A as a light emitting device.

Referring to FIG. 1B, three first LED cells A1, A2, and A3 are arranged in a row, and three second LED cells B1, B2, and B3 are arranged in parallel to each other. Two third LED cells C1 and C2 are arranged between the first and second LED cells.

Through this arrangement, the wirings ac1, ac2, bc1, and bc2 for connection with other first and second LED cells based on the third LED cells C1 and C2 may be more simply implemented.

As shown in FIG. 1B, the AC driving light emitting device according to the present invention includes the second electrode (+) of the first and second first LED cells A1 and A2 and the first third LED cell C1. Wiring ac1 connecting the first electrode (−) and the first electrode (−) of the first and second second LED cells B1 and B2 and the second electrode of the first third LED cell C1 Wiring bc1 connecting the positive electrode and the first electrode (-) of the second and third first LED cells A2 and A3 and the second electrode (+) of the second third LED cell C2 Wiring (ac2) for connecting the second electrode (+) of the second and third second LED cell (B2, B3) and the first electrode (-) of the second third LED cell (C2) Has wiring. The wiring between the cells may be implemented by a known type of wiring such as an air bridge or a wire.

In addition, a first electrode (−) of the first first LED cell A1 and a second electrode of the first second LED cell B1 are connected to the first contact P1, and the second contact P2 is connected to the first contact P1. ) Is connected to the second electrode (+) of the third first LED cell (A3) and the first electrode (-) of the third second LED cell (B3).

2 is a plan view showing a light emitting device according to an embodiment of the present invention. FIG. 2 may be understood to represent a preferred type of light emitting device in which FIG. 1B is actually implemented.

The AC driving type light emitting device shown in FIG. 2 includes a rectangular substrate 31 formed of four sides, that is, first to fourth sides e1 to e4.

Three first LED cells A1, A2, and A3 are arranged side by side along a first side e1 of the upper surface of the substrate 31, and a second side e2 facing the first side e1 is disposed. Accordingly, three second LED cells B1, B2, and B3 are arranged side by side. Two third LED cells C1 and C2 are arranged between the rows of the first and second LED cells.

In the first to third LED cells employed in the present embodiment, the first and second electrodes 37, 37 'and 38 are disposed so as to be adjacent to opposite sides on the upper surface of the corresponding cell, respectively. In addition, the first and second electrodes 37, 37 ′ and 38 are formed to have portions extending along the sides thereof. As such, the first and second electrodes 37, 37 ′ and 38 are formed to extend on opposite sides, thereby achieving a more uniform current distribution in the entire light emitting area of each LED cell. Can be improved.

As in the present embodiment, the first first LED cell A1 may be formed to extend to the first second LED cell B1 along the third side e3 of the upper surface of the substrate 31. In addition, the last third LED cell B3 may be formed to extend to the third first LED cell A3 along the fourth side e4 of the upper surface of the substrate 31. By adjusting the size and shape of these cells, a higher degree of integration can be realized.

The AC driving light emitting device includes a first external electrode P1 connected to a first electrode of the first first LED cell A1 and a second electrode of the first second LED cell B1, and a third first electrode. The second external electrode P2 is connected to the second electrode of the LED cell A3 and the second electrode of the third second LED cell B3.

Preferably, as shown in FIG. 2, the first external electrode P1 is positioned on the first LED cell A1, and the second external electrode P2 is the third third electrode. 2 may be located on the cell (B3). Since the extended LED cells A1 and B3 are advantageously designed to have a relatively larger light emitting area than other cells, it may be easy to secure an area for the external electrode. In addition, in order to prevent the voltage from being concentrated in a specific cell, the first to third LED cells are preferably formed to have almost the same light emitting area.

The term "light emitting area" as used herein refers to an area participating in light emission, and can be understood as the active layer area of each cell.

3A to 3D are side cross-sectional views of the light emitting device shown in FIG.

The first to third LED cells of the AC driving light emitting device according to the present embodiment are the first conductive semiconductor layer 34, the active layer 35, and the second conductive semiconductor layer sequentially grown on the substrate 31. Can be obtained from (36). That is, the first conductive semiconductor layer 34, the active layer 35, and the second conductive semiconductor layer 36 for the light emitting structure grown on the entire surface of the substrate 31 are separated in units of cells through an appropriate separation process. By doing so, an arrangement of the plurality of first to third LED cells shown in FIG. 1 can be obtained.

3A to 3D are side cross-sectional views of the light emitting device shown in FIG. 2, and show a separation form of each cell unit that can be preferably employed, and the structure shown in FIG. .

3A is a cross-sectional view of the light emitting device shown in FIG. 2 taken along the line X1-X1 '.

Referring to FIG. 3A, the first first LED cell A1 and the second first LED cell A2 are separated by a complete separation process I1 exposing to the substrate region, whereas the second first LED cell A1 is separated from the second first LED cell A1. A2) and the third first LED cell A3 may be divided into a semi-separation process I2 exposing only the first conductive semiconductor layer region. Preferably, the second first LED cell A2 and the third first LED cell A3 may share the first electrode 37 ′ formed in the exposed region of the first conductivity-type semiconductor layer 34. have.

In this manner, a semi-separation process is partially applied in the range where the desired LED driving circuit is maintained, and the first electrode 37 'is formed in the exposed first conductive semiconductor layer region to provide a shared electrode between adjacent cells. The process can be simplified and the degree of integration can be further improved.

3B is a cross-sectional view of the light emitting device shown in FIG. 2 taken along the line X2-X2 '.

As shown in FIG. 3B, the first first LED cell A1 and the third second LED cell B3 are separated from the third LED cells C1 and C2 by a complete separation process I1. The two LED cells B1 and B2 are separated from each other by a complete separation process I1.

3C is a cross-sectional view of the light emitting device shown in FIG. 2 taken along the line Y1-Y1 '.

As shown in FIG. 3C, the first LED cell A1, the second LED cell B3, and the third LED cell are separated from each other by a complete separation process I1. The wiring 39 between the electrodes of each cell may be implemented by an air bridge or a wire as described above.

3D is a cross-sectional view of the light emitting device shown in FIG. 2 taken along the line Y2-Y2 '.

As shown in Fig. 3D, the first first LED cell A1 and the first second LED cell B1 are separated by a complete separation process I1. Similarly, the separation and connection form of the last third and third LED cells A3 and B3 can be similarly understood.

Of course, unlike the present embodiment, all of the first to third LED cells can be formed to be separated from other adjacent LED cells by a region (complete separation process) exposed to the substrate, each cell without a shared electrode It can be formed to have separate first and second electrodes.

As shown in FIG. 2, the third LED cells C1 and C2 have two first LED cells A1 to which electrodes are connected so as to improve the degree of integration and to have a short length of wiring for connecting the electrodes of other LED cells. Preferably, A2 / A2, A3 and the electrode are arranged to be adjacent to two second LED cells B1, B2 / B2, B3.

As illustrated in FIG. 2, the third LED cells C1 and C2 may be formed to have upper surfaces that are parallelograms inclined in the arrangement direction. The first and second electrodes 37 and 38 of the third LED cell are preferably formed adjacent to both sides inclined from the upper surface of the third LED cell. The design of the third LED cells C1 and C2 may shorten the electrode wiring connection, thereby reducing defects that may occur during the wiring forming process.

In order to simplify the wiring connection, the first and second electrodes 37 and 38 of the first LED cells A1, A2 and A3 are arranged in the direction in which the first LED cells are arranged on the corresponding LED cells. The first and second electrodes 37 and 38 of the second LED cells B1, B2, and B3 are formed to be adjacent to both sides perpendicular to the sides of the second LED cells B1, B2, and B3, respectively. It is preferably formed adjacent to both sides perpendicular to.

This arrangement may be implemented in various ways, for example, in addition to the form shown in Figure 2 may be implemented in the illustrated example of FIG.

In the light emitting device shown in Fig. 4, each cell sequentially forms a first conductive semiconductor layer 44, an active layer (not shown), and a second conductive semiconductor layer 46 on the substrate similarly to the previous embodiment. After that, the structure may be obtained through an appropriate cell unit separation process. The form obtained by each cell unit separation process can be understood as a structure similar to that described in FIGS. 3A to 3D.

In this embodiment, the third LED cells C1 and C2 are provided in a form having a substantially rectangular top surface composed of two opposing long sides and two opposing short sides. Of course, in the strict sense it can be understood to include not only a rectangle, but also a nearly rectangular shape partially modified to have a higher degree of integration.

In the present embodiment, the first and second electrodes 47 and 48 of the third LED cells C1 and C2 may be formed to be adjacent to two long sides of the rectangular upper surface, respectively.

In this case, the third LED cells C1 and C2 are preferably arranged such that their long sides are substantially perpendicular to the arrangement direction of the third LED cells C1 and C2.

In addition, both sides of the first and second electrodes 47 and 48 of the first LED cells A1-A3 are parallel to the array direction of the first LED cells on the top surface of the first LED cells A1-A3, respectively. The first and second electrodes 47 and 48 of the second LED cells B1 to B3 are arranged to be adjacent to the second LED cells B1 to B3, respectively. It is preferably formed so as to be adjacent to both sides parallel to.

* For easier understanding of the present invention, the first and second LED cells are three and one light emitting device of the third LED cell has been described by way of example, but similarly in embodiments having a larger number of LED cells. Can be applied.

The present invention can be expressed as follows when generalized without defining the number of specific cells.

That is, in the AC drive light emitting device according to the present invention, the first and second LED cells are K (where K is an integer less than or equal to 3) and are arranged to form heat in parallel with each other, and the third LED cell is K. -1 and may be arranged between the rows of the first and second LED cells. In this case, the electrode connection of the first to third LED cells can be expressed as follows.

When defined in the order of the first to third LED cells in a particular arrangement direction, the m-th (where m is an odd number less than K) first electrode of the third LED cell is the m-th and m + 1st first And a second electrode of the m th third LED cell is connected to a first electrode of the m th and m + 1 th second LED cells. The first electrode of the nth (where n is an even number less than K) third LED cell is connected to the second electrode of the nth and n + 1th second LED cells, and the second of the nth third LED cell The electrode is connected to the first electrode of the nth and n + 1th first LED cells.

The first electrode of the first first LED cell and the second electrode of the first second LED cell are connected to each other to form a contact to be provided to the first external electrode, and the first and second LEDs corresponding to the last K-th. One of the electrodes of the cell is connected to each other that is not connected to the third LED cell to form a contact to be provided to the second external electrode.

In addition, the separation form between the cells illustrated in FIGS. 3A to 3D may be generalized and described as follows.

That is, all pairs of the m th second LED cell and the m + 1 th second LED cell are separated from each other by an area where the first conductivity type semiconductor layer is exposed, and are exposed to the exposed area of the first conductivity type semiconductor layer. It can be designed to share one formed first electrode. Similarly, all pairs of the n th first LED cell and the n + 1 th first LED cell are separated from each other by a region where the first conductivity type semiconductor layer is exposed and the exposed portion of the first conductivity type semiconductor layer is exposed. It can be designed to share one first electrode formed in the region.

In this case, it is preferable to separate the other adjacent first to third LED cells through a complete separation process exposed to the substrate region.

FIG. 5 is a plan view showing a light emitting device according to a preferred embodiment of the present invention, and FIG. 6 shows an equivalent circuit of the light emitting device shown in FIG.

The light emitting device 100 shown in FIG. 5 includes a substrate 101 and first to third ladder network LED arrays 110, 120, and 130 formed side by side on the substrate 101. The first to third ladder network LED arrays 110, 120, and 130 are arranged from one side toward the other side facing each other (see dotted line).

Each of the first to third ladder network LED arrays 110, 120, and 130 may include thirteen first LED cells 110A, 120A, 130A, and second LED cells 110B, 120B, and 130B arranged in a row on an upper surface of the substrate 101. Twelve third LED cells arranged in a row in parallel between the rows of the first and second LED cells 110A, 120A, 130A and 110B, 120B, 130B on the upper surface of the substrate 100. (110C, 120C, 130C).

In addition, the first to third ladder network LED array (110, 120, 130) has a connection form between the first to third LED cells for implementing a ladder network circuit. This type of connection can be implemented in a manner similar to the connection between the LED cells illustrated in FIG.

Hereinafter, in order to more easily explain the connection between the LED cells employed in the present embodiment, the plurality of first to third LED cells are referred to in the order in a specific arrangement direction (here, the direction from right to left). .

The first electrodes 117, 127, 137 of the m th (where m is an odd number less than 13) third LED cells 110C, 120C, 130C are the m th and m + 1 th first LED cells 110A, 120A, 130A. Second electrodes 118, 128 and 138. The second electrodes 118, 128, 138 of the m th third LED cells 110C, 120C, 130C are connected to the first electrodes 117, 127, 137 of the m th and m + 1 th second LED cells 110B, 120B, 130B.

The first electrodes 117, 127, 137 of the n th (where n is an even number less than 13) third LED cells 110C, 120C, 130C are the n th and n + 1 th second LED cells 110B, 120B, 130B. Second electrodes 118, 128 and 138. The second electrodes 118, 128, 138 of the n th third LED cells 110C, 120C, and 130C are connected to the first electrodes 117, 127, 137 of the n th and n + 1 th first LED cells 110A, 120A, and 130A.

The first electrode of the first first LED cell and the second electrode of the first second LED cell are connected to each other and are not connected to the third LED cell of the electrodes of the last first and second LED cells, that is, 13 The second electrode of the first first LED cell and the first electrode of the thirteenth second LED cell are connected to each other.

* The connection between the electrodes of the LED cell can be implemented by the wiring means (119, 129, 139). For example, the known wiring means is not limited thereto, and may include an air bridge or a wire.

As described above, the matters illustrated and described in FIGS. 2 and 3A to 3D may be combined and understood in the description of the present embodiment as long as it does not contradict the present embodiment.

For example, the first to third LED cells are stacked on the first conductive semiconductor layer 104, the active layer 105, and the second conductive semiconductor layer 106, all of which are sequentially grown on the substrate 101. The sieve may be of a structure obtained through a suitable separation process (see FIGS. 7A-7C). In addition, the first and third LED cells may be separated to expose only the first conductivity type semiconductor layer so that the first electrode is shared by two adjacent cell units (see FIG. 3A).

In addition, the third LED cells 110C, 120C, and 130C may be formed to have upper surfaces that are parallelograms inclined in the arrangement direction, respectively, as shown. The first and second electrodes 117, 127, 137, and 118, 128, 138 of the third LED cells 110C, 120C, and 130C may be formed adjacent to both sides inclined from the upper surface of the third LED cell, respectively. The design of the third LED cells 110C, 120C, and 130C may shorten the electrode wiring.

Further, in order to simplify the wiring connection, the first and second electrodes 117, 127, 137, and 118, 128, 138 of the first LED cells 110A, 120A, and 130A are respectively formed on the upper surface of the corresponding LED cell. The first and second electrodes 117, 127, 137, and 118, 128, 138 of the second LED cells 110C, 120C, and 130C are formed to be adjacent to both sides perpendicular to the array direction, respectively. It is preferable to be formed adjacent to both sides perpendicular to the arrangement direction.

In this embodiment, the second ladder network LED array 120 is arranged to be positioned between the first and third ladder network LED arrays 110 and 130.

Preferably, the first and second ladder network type LED arrays 110 and 120 are arranged such that the columns of the respective second LED cells 110B and 120B are adjacent to each other, and the second and third ladder network circuits. Type LED arrays 120 and 130 are arranged such that the columns of each of the first LED cells 120A and 130A are adjacent to each other.

This arrangement facilitates the connection between the ladder network circuits described below. That is, in the present embodiment, the second ladder network LED array 120 is electrically connected to the first and third ladder network LED array (110, 130) adjacent at both ends.

7A to 7C are plan and side cross-sectional views showing the connection portion A of the ladder network circuit row of the light emitting device shown in FIG.

Among the thirteenth second LED cells 110B of the first ladder network circuit type LED array 110 that are not connected to the third LED cell 110C (that is, the first electrode 117 in the present embodiment) and And an electrode not connected to the third LED cell 120C of the thirteenth second LED cell 120B of the second ladder network circuit type LED array 120 (that is, the first electrode 127 in the present embodiment). ) Are connected to each other.

Similarly, an electrode not connected to the third LED cell 110C of the first first LED cell 120A of the second ladder network type LED array 120 (that is, in the present embodiment, the first electrode ( 127)) and an electrode not connected to the third LED cell 130C of the thirteenth first LED cell 130A of the second ladder network type LED array 130 (that is, the first embodiment in the present embodiment). The electrodes 137 are connected to each other.

In this embodiment, it has a form connected with each other via the 2nd electrode. In this case, it is possible to easily implement the connection between the ladder network circuit by implementing the connection electrode between the ladder network circuit in the form of a common electrode.

As shown in FIGS. 7A to 7C, the 13th second LED cell 110B of the first ladder network circuit type LED array 110 and the 13th second of the second ladder network circuit type LED array 120 are illustrated. The second LED cell 120B may be separated and obtained through a semi-separation process so that only the first conductive semiconductor layer 104 is exposed in a T shape when viewed from the top. In addition, the first common electrode 107 may be formed in a portion of the exposed region adjacent to one side region of the substrate so that the two LED cells are shared with each other, and the connection between the ladder network circuits described above may be realized.

Similarly, the first second LED cell 120B of the second ladder network circuit LED array 120 and the first second LED cell 130B of the third ladder network circuit LED array 130. ) May be separated and obtained through a semi-separation process so that only the first conductive semiconductor layer 104 is exposed to the T-shape when viewed from the top surface. In addition, the first shared electrode 107 may be formed in a portion of the exposed area adjacent to one side of the substrate to form two LED cells to share each other, and the connection between the ladder network circuits described above may be realized.

Thus, like the equivalent circuit shown in FIG. 6, the first to third ladder network circuits 110, 120, and 130 may be connected side by side to implement an AC driving type light emitting device having a desired ladder network circuit type.

In the present embodiment, a light emitting device having three ladder network circuit LED arrays is exemplified, but is not limited to the number of ladder network circuit LED arrays. For example, the present invention may be implemented in a form having only two ladder network LED arrays, or may be implemented with four or more ladder network LED arrays. Of course, it will be apparent to those skilled in the art that the number of LED cells belonging to each ladder network LED array is not limited to the illustrated form.

As such, the present invention is not limited by the above-described embodiments and the accompanying drawings, but is limited by the appended claims. It will be apparent to those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims, As will be described below.

100: light emitting device 31, 101: substrate
34, 104: first conductive semiconductor layer 35, 105: active layer
36 and 106: second conductivity-type semiconductor layer 107: first shared electrode
37, 117, 127: first electrode 38, 118, 128, 138: second electrode
110, 120, 130: first, second, third ladder network circuit LED array
110A, 120A, 130A: first LED cell 110B, 120B, 130B: second LED cell
110C, 120C, 130C: Third LED Cell

Claims (10)

Board;
K first LED cells arranged on an upper surface of the substrate, where K is an integer of 3 or less;
K second LED cells arranged on an upper surface of the substrate in parallel with a row of the first LED cells;
K-1 third LED cells arranged between the column of the first LED cell and the column of the second LED cell on the substrate;
A first external electrode connected to a first electrode of a first LED cell of the first LED cells and a second electrode of a first LED cell of the second LED cells; And
A second external electrode connected to an electrode of the K-th first and second LED cells that is not connected to the third LED cell,
First and second current loops driven in first and second half periods of an AC voltage applied between the first and second external electrodes, respectively,
The first current loop includes a second LED cell of (2r-1), a second LED cell of 2r and a third LED cell of (K-1) in series, and the second current. The loop consists of a 2r first LED cell, a (2r-1) second LED cell, and the (K-1) third LED cells connected in series with each other, where r is a natural number of AC driven light emission. Device.
The method of claim 1,
The first electrode of the (2r-1) th third LED cell is connected to the second electrode of the (2r-1) th and the 2r first LED cells, and the (2r-1) th third The second electrode of the LED cell is connected to the first electrode of the (2r-1) th and the 2rth second LED cell,
The first electrode of the second 3rd LED cell is connected to the second electrode of the second 2nd and (2r + 1) second LED cells, and the second electrode of the second 3rd LED cell is connected to the 2r. An AC driving light emitting device connected to the first electrode of the first and (2r + 1) th LED cells.
3. The method of claim 2,
The first and second electrodes of the first to third LED cells, respectively disposed adjacent to both sides of the upper surface of the cell, the AC drive light emitting device having a portion extending along the corresponding side.
The method of claim 3,
The upper surface of the substrate is a rectangle consisting of the first to fourth sides,
The first and second LED cells are arranged side by side along opposite first and second sides, respectively, and the first and second LED cells are disposed adjacent to the third side, and the Kth The first and second LED cells of the AC drive light emitting device is disposed to be adjacent to the fourth side facing the third side.
5. The method of claim 4,
And the third LED cells are arranged to be adjacent to two first LED cells connected to electrodes and two second LED cells connected to electrodes.
5. The method of claim 4,
And said third LED cells each have a parallelogram top surface inclined in an array direction thereof.
The method of claim 1,
The first and second electrodes of the third LED cell are each formed to be adjacent to two long sides of a rectangular upper surface, and the third LED cell has a long side substantially perpendicular to the arrangement direction of the third LED cell. Arranged to be,
The first and second electrodes of the first LED cell are formed to be adjacent to both sides parallel to the array direction of the first LED cell on the upper surface of the first LED cell, respectively, the first and second of the second LED cell And two electrodes each adjacent to both sides parallel to an array direction of the second LED cell on an upper surface of the second LED cell.
The method of claim 1,
And the first to third LED cells each include a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer sequentially formed on the substrate.
9. The method of claim 8,
At least one pair of the (2r-1) th and 2rth second LED cells are separated from each other by an exposed region of the first conductivity type semiconductor layer, and alternating current driving sharing a first electrode formed in the exposed region. Light emitting device.
10. The method of claim 9,
At least one pair of the 2r-th and (2r + 1) -th first LED cells are separated from each other by a region where the first conductivity type semiconductor layer is exposed, and alternating current driving sharing a first electrode formed in the exposed region. Light emitting device.

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