JP4585014B2 - Light emitting device - Google Patents

Description

  The present invention relates to a light emitting device in which a plurality of light emitting elements are formed on a substrate.

  When a light emitting means such as a light emitting element (LED) is used for a display application or the like, the use conditions are a drive voltage of about 1 to 4 V and a drive current of about 20 mA. By the way, with the recent development of short-wavelength LEDs using GaN-based compound semiconductors and the practical use of solid-state light sources such as full color and white, it has been studied to gradually apply LEDs to lighting applications. When the LED is applied to lighting applications, there is a situation in which the LED is used under conditions different from the use conditions of the drive voltage of 1 to 4 V and the drive current of 20 mA. For this reason, a device has been devised in which a large current is passed through the LED to increase the light emission output. In order to flow a large current, it is necessary to increase the pn junction area of the LED and reduce the current density.

JP 2001-307506 A JP 59-206873 A

  When using an LED as a light source for illumination, it is convenient that an alternating current is used as a power source and it can be used at a driving voltage of 100 V or more. If the same light output is obtained by applying the same power, the power loss can be reduced by applying a high voltage while maintaining a low current value. However, in the conventional LED, the drive voltage cannot always be sufficiently increased.

  The present invention has been made in view of the above-described problems of the prior art, and an object thereof is to provide a light-emitting device that can operate at a high driving voltage.

The present invention is a light-emitting device in which a plurality of GaN-based light-emitting diode elements are formed on an insulating substrate, wherein the plurality of light-emitting diode elements are arranged in a matrix on the insulating substrate, and the plurality of light-emitting diodes The elements are connected in parallel to the two AC power supply electrodes so as to be electrically divided into a first set and a second set with opposite polarities, and the first set of light emitting diode elements is a first set. A column of light emitting diode elements and a column of second light emitting diode elements, wherein the second set of light emitting diode elements includes a column of third light emitting diode elements and a column of fourth light emitting diode elements; A third light emitting diode element row is disposed between the first light emitting diode element row and the second light emitting diode element row, and the matrix of the first light emitting diode element rows. The electrode of the light emitting diode element at the end of one side of the row, the electrode of the light emitting diode element at the end of the first side of the row of the second light emitting diode device, and the row of the third light emitting diode element The electrode of the light emitting diode element at the end on the one side and the electrode of the light emitting diode element at the end on the one side of the column of the fourth light emitting diode elements are shared and electrically connected , and, said the two AC power supply electrode directly is characterized in that no Tei is connected.

According to the present invention, in the light-emitting device described in the preceding paragraph, the first electrode of the light-emitting diode element at the end on one side of the arrangement of the light-emitting diode elements constituting the first column on the matrix; , The second electrode of the light emitting diode element at the end of the one side of the light emitting diode element constituting the second row, and the one side of the light emitting diode element constituting the third row. The third electrode of the light emitting diode element at the end and the fourth electrode of the light emitting diode element at the end on the one side of the light emitting diode elements constituting the fourth row are shared, respectively, The first electrode and the fourth electrode have the same polarity, the second electrode and the third electrode have the same polarity, and the first electrode and the fourth electrode The polarities of the electrode, the second electrode, and the third electrode are It becomes possible to provide a light emitting device according to claim.

  According to the present invention, light can be emitted by driving at a high driving voltage.

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

  FIG. 1 shows a basic configuration of an LED 1 as a GaN-based compound semiconductor light-emitting element in the present embodiment. In the LED 1, a GaN layer 12, a Si-doped n-type GaN layer 14, an InGaN light emitting layer 16, an AlGaN layer 18, and a p-type GaN layer 20 are sequentially stacked on a substrate 10, and a p-electrode 22 is in contact with the p-type GaN layer 20. The n electrode 24 is formed in contact with the n-type GaN layer 14.

  The LED shown in FIG. 1 is manufactured by the following process. That is, first, a sapphire c-plane substrate is heat-treated in a hydrogen atmosphere at 1100 ° C. for 10 minutes by a MOCVD apparatus. Then, the temperature is lowered to 500 ° C., silane gas and ammonia gas are supplied for 100 seconds, and a discontinuous SiN film is formed on the substrate 10. This process is for reducing the dislocation density in the device, and the SiN film is omitted in the figure. Next, trimethylgallium and ammonia gas are supplied at the same temperature to grow a GaN layer to a thickness of 20 nm. The temperature is raised to 1050 ° C., and trimethylgallium and ammonia gas are supplied again to grow the undoped GaN (u-GaN) layer 12 and the Si-doped n-type GaN layer 14 to a thickness of 2 μm each. Thereafter, the temperature is lowered to about 700 ° C., and the InGaN light emitting layer 16 is grown to a thickness of 2 nm. The target composition is x = 0.15, ie In0.15Ga0.85N. After the light emitting layer 16 is grown, the temperature is raised to 1000 ° C. to grow the AlGaN hole injection layer 18 and further the p-type GaN layer 20 is grown.

  After the p-type GaN layer 20 is grown, the wafer is taken out from the MOCVD apparatus, and Ni 10 nm thickness and Au 10 nm thickness are sequentially formed on the growth layer surface by vacuum deposition. The metal film becomes the p-type transparent electrode 22 by heat treatment at 520 ° C. in a nitrogen gas atmosphere containing 5% oxygen. After forming the transparent electrode, a photoresist is applied to the entire surface, and etching for forming the n-type electrode is performed using the photoresist as a mask. The etching depth is, for example, about 600 nm. Ti 5 nm thickness and Al 5 nm thickness are formed on the n-type GaN layer 14 exposed by etching, and an n-type electrode 24 is formed by heat treatment at 450 ° C. for 30 minutes in a nitrogen gas atmosphere. Finally, the back surface of the substrate 10 is polished to 100 μm, the chip is cut out, and mounted to obtain the LED 1.

  In FIG. 1, one LED 1 is formed on the substrate 10, but in this embodiment, a plurality of LEDs 1 are formed monolithically and in a two-dimensional array on the substrate 10, and each LED is connected to form a light emitting device. (Chip).

  FIG. 2 shows an equivalent circuit diagram of the light emitting device. In FIG. 2, the light emitting element groups formed in a two-dimensional array are divided into two sets of the same number (four in the figure), each set of LEDs 1 is connected in series, and two sets of LED rows are electrodes (drive electrodes). ) Are connected in parallel so as to have a reverse polarity. Thus, by connecting the LED strings in series, the LED 1 can be driven with a high voltage obtained by adding the drive voltages. In addition, since each LED string is connected in parallel to the electrodes so that the polarities are opposite to each other, even when an AC power source is used as a power source, one of the LED columns always emits light during each cycle of the power source. Therefore, efficient light emission can be performed.

  FIG. 3 shows a partial plan view of a plurality of LEDs monolithically formed on the substrate 10. FIG. 4 is a sectional view taken along the line IV-IV in FIG. In FIG. 3, a p-electrode 22 and an n-electrode 24 are formed on the upper surface of the LED 1 as shown in FIG. The p-electrode 22 and the n-electrode 24 of the adjacent LEDs 1 are connected by an air bridge wiring 28, and a plurality of LEDs 1 are connected in series.

  In FIG. 4, each LED 1 is simply shown for convenience of explanation. That is, only the n-GaN layer 14, the p-GaN layer 20, the p-electrode 22, and the n-electrode 24 are shown. Needless to say, an InGaN light emitting layer 16 or the like actually exists as shown in FIG. The air bridge wiring 28 connects the p electrode 22 to the n electrode 24 through the air. As a result, it is not necessary to dispose an electrode along the etching groove as compared with a method in which an insulating film is applied to the element surface, an electrode is formed thereon, and the p-electrode 22 and the n-electrode 24 are electrically connected. Therefore, it is possible to avoid the problem that the elements constituting the insulating material are thermally diffused from the wiring breakage or from the insulating film to the n layer and the p layer to deteriorate the LED 1. The air bridge wiring 28 is used not only between the LEDs 1 but also for connection between the LEDs 1 and an electrode (not shown).

  Further, as shown in FIG. 4, each LED 1 is independent from each other and needs to be electrically insulated. For this reason, each LED1 becomes the structure isolate | separated on the sapphire substrate 10. FIG. Since sapphire is itself an insulator, each LED 1 can be electrically isolated. As described above, by using the sapphire substrate 10 as a resistor for electrically separating the LEDs, it is possible to easily and reliably electrically separate the LEDs.

  In addition, as a light emitting element, it can also be set to MIS besides LED which has a pn junction.

  FIG. 5 shows another equivalent circuit diagram of the light emitting device. In the figure, 20 LEDs 1 are connected in series to form one LED array, and two LED arrays (total of 40 LEDs) are connected in parallel to the power source. The drive voltage of the LED 1 is set to 5V, and the drive voltage of each LED array is 100V. As in FIG. 2, the two LED arrays are connected in parallel to the power supply so as to have opposite polarities, and either LED array always emits light regardless of the polarity of the power supply.

  FIG. 6 specifically shows a two-dimensional array. This corresponds to the equivalent circuit diagram of FIG. In the figure, a total of 40 LEDs 1 are formed on the sapphire substrate 10, each being divided into two sets of 20 pieces and connected in series by an air bridge wiring 28 to form two LED arrays. More specifically, the LEDs 1 are all the same shape and are the same size, and one LED array is arranged on a straight line of 6, 7, and 7, respectively, from the top. ) And the second row (seven) are formed in opposite directions, and the second row and the third row are also formed in opposite directions. The first row and the second row, and the second row and the third row are arranged apart from each other. This is because the columns of the other LED array are alternately inserted as will be described later. The rightmost LED 1 in the first row and the rightmost LED 1 in the second row are connected by an air bridge wiring 28. The leftmost LED 1 in the second row and the leftmost LED 1 in the third row are also connected by the air bridge wiring 28 to form a zigzag arrangement. The leftmost LED 1 in the first row is connected to an electrode (pad) 32 formed in the upper left portion of the substrate 10 by an air bridge wiring 28, and the rightmost LED 1 in the third row is formed in the lower right portion of the substrate 10. An air bridge wiring 28 is connected to the electrode (pad) 32. The two electrodes (pads) 32 are also square with the same shape as the LED 1. The other LED array is formed to be staggered in the gap between the one LED array described above. That is, the other LED array is arranged on a straight line with 7, 7, and 6 from the top, and the first column from the top is formed between the first column and the second column of one LED array. The second column is formed between the second column and the third column of one LED array, and the third column is formed below the third column of the one LED array. The first column and the second column of the other LED array, and the second column and the third column are also formed in opposite directions, and the rightmost LED 1 of the first column is the second column. The leftmost LED 1 in the second row is connected to the rightmost LED 1 by the air bridge wiring 28, and the leftmost LED 1 in the second row is connected to the leftmost LED 1 by the air bridge wiring 28 to form a zigzag shape. The leftmost LED in the first column of the other LED array is connected to the electrode 32 formed in the upper left portion of the substrate 10 by the air bridge wiring 28, and the rightmost LED 1 in the third column is formed in the lower right portion of the substrate 10. The air bridge wiring 28 is connected to the formed electrode 32. The polarities of the one LED array and the other LED array with respect to the electrode 32 are opposite to each other. The overall shape of the light emitting device (chip) is rectangular. It should also be noted that the two electrodes 32 to which power is supplied are formed apart from each other in a rectangular diagonal position.

  FIG. 7 shows a circuit diagram of FIG. It will be apparent that the respective LED arrays are connected in series while being bent in a zigzag manner, and two LED arrays are formed in a zigzag manner between each other. With such an arrangement, a large number of LEDs 1 can be arranged on the small substrate 10. Further, since only two electrodes 32 are required for 40 LEDs 1, the use efficiency of the substrate 10 can be improved in this respect. In addition, when the LEDs 1 are individually formed to separate the LEDs 1, it is necessary to cut and separate the wafer. In the present embodiment, the LEDs 1 can be separated by etching. The interval can be reduced. Thereby, the size of the sapphire substrate 10 can be further reduced. Separation of the LEDs 1 is achieved by etching away regions other than the LED 1 until the substrate 10 is reached by using a photoresist, reactive ion etching, and wet etching together. Since each LED array emits light alternately, it is possible to improve the light emission efficiency and heat dissipation characteristics. Further, if the number of LEDs 1 connected in series is changed, the driving voltage as a whole can also be changed. Moreover, if the area of LED1 is made small, the drive voltage per LED can also be made high. When 20 LEDs 1 are connected in series, a light output of about 150 mW can be obtained when driven by a commercial power supply (100 V, 60 Hz). In this case, the drive current is about 20 mA.

  As can be seen from FIG. 7, when two LED arrays are alternately arranged in a zigzag shape, a crossing portion 34 is inevitably generated in the air bridge wiring 28. For example, when connecting the first column and the second column of the other LED array, it intersects with a wiring portion for connecting the first column and the second column of one LED array. However, since the air bridge wiring 28 of the present embodiment is not bonded to the substrate 10 as described above and passes through the air away from the substrate 10, the air bridge wirings 28 come into contact with each other at the crossover portion 34, and are short-circuited. This can be easily avoided. This is one of the advantages of using the air bridge wiring 28. The air bridge wiring 28 is formed as follows, for example. That is, a 2 μm-thick photoresist is applied to the entire surface, a hole is formed in the shape of the air bridge wiring, and post-baking is performed. On top of this, 10 nm of Ti and 10 nm of Au are deposited in this order by vacuum deposition. Further, a photoresist is again applied to the entire surface with a thickness of 2 μm, and a hole is made only in a portion where the air bridge wiring is formed. Next, Au having a thickness of 3 to 5 μm is attached to the entire surface of the electrode by ion plating (plating) in an electrolytic solution using Ti and Au as electrodes. Thereafter, the sample is immersed in acetone, and the photoresist is dissolved and removed by ultrasonic cleaning to complete the air bridge wiring 28.

Thus, by arranging a plurality of LEDs 1 in a two-dimensional array, it is possible to drive with a high drive voltage, particularly a commercial power supply, while effectively utilizing the substrate area. Various other patterns are possible. In general, the two-dimensional array pattern preferably has the following conditions.
(1) It is desirable that the shape and the electrode position of each LED be the same in order to pass a current uniformly to each LED and obtain uniform light emission.
(2) In order to cut the wafer into chips, it is desirable that the sides of each LED be straight.
(3) In order to improve the light extraction efficiency, in order to utilize reflection from the periphery using a standard mount, the LED preferably has a planar shape close to a square.
(4) The size of the two electrodes (bonding pads) is about 100 μm square, and it is desirable that they are separated from each other.
(5) In order to effectively use the wafer area, it is desirable that the proportion of wiring and pads is small. Of course, these are not essential, and for example, it is possible to use a planar shape triangle as the shape of each LED. Even if each LED has a triangular shape, the overall shape can be made substantially square by combining them. Hereinafter, some examples of the two-dimensional array pattern are shown.

  FIG. 8 shows an example in which a total of six LEDs 1 are two-dimensionally arranged, and FIG. 9 shows a circuit diagram thereof. The arrangement of FIG. 8 is basically the same as the arrangement of FIG. 6, and the total of six LED arrays are divided into two sets of the same number, and are each composed of three LEDs connected in series. One LED array is arranged in a zigzag shape. From the top, one LED 1 is formed in the first row, and two LEDs 1 are formed in the second row. The LEDs in the first row and the rightmost LED 1 in the second row are connected in series by the air bridge wiring 28, and the two LEDs 1 in the second row are also connected in series by the air bridge wiring 28. Electrodes (pads) 32 are formed on the upper left and lower left of the substrate 10, the first row of LEDs 1 are connected to the upper left electrode 32 by air bridge wiring, and the leftmost LED 1 of the second row is connected to the lower left. Connected to the electrode 32. The other LED array is also arranged in a zigzag shape. From the top, two LEDs 1 are formed in the first row, and one LED 1 is formed in the second row. The first column of the other LED array is formed between the first column and the second column of the one LED array, and the second column of the other LED array is the second column of the one LED array. Formed below the eyes. The rightmost LED 1 in the first row is connected in series to the second row LED 1 via the air bridge wiring 28, and the two LEDs 1 in the first row are also connected in series via the air bridge wiring 28. The LED 1 at the left end of the first row is connected to the upper left electrode 32 by the air bridge wiring 28, and the LED 1 in the second row is connected to the lower left electrode 32 by the air bridge wiring 28. As can be seen from FIG. 9, also in this example, the two LED arrays are connected to the electrode 32 in parallel to each other and are connected to have opposite polarities. Therefore, when the AC power is supplied, the two LED arrays emit light alternately.

  FIG. 10 shows an example in which a total of 14 LEDs are two-dimensionally arranged, and FIG. 11 shows a circuit diagram thereof. A total of 14 LED arrays are divided into 2 sets, each consisting of 7 LEDs connected in series. One LED array is arranged in a zigzag shape, and from the top, three LEDs 1 are formed in the first row, and four LEDs 1 are formed in the second row. The leftmost LED in the first row and the leftmost LED1 in the second row are connected in series by an air bridge wiring 28, and the three LEDs in the first row and the four LEDs 1 in the second row are also connected. The air bridge wiring 28 is connected in series. Electrodes (pads) 32 are formed on the upper right portion and lower right portion of the substrate 10, the rightmost LED 1 in the first row is connected to the upper right electrode 32 by an air bridge wiring, and the rightmost LED 1 in the second row is on the right Connected to the lower electrode 32. The other LED array is also arranged in a zigzag shape. From the top, four LEDs 1 are formed in the first row, and three LEDs 1 are formed in the second row. The first column of the other LED array is formed between the first column and the second column of the one LED array, and the second column of the other LED array is the second column of the one LED array. Formed below the eyes. The leftmost LED 1 in the first row is connected in series to the leftmost LED 1 in the second row by an air bridge wiring 28. The four LEDs 1 in the first row and the three LEDs 1 in the second row are also connected in series. The rightmost LED 1 in the first row is connected to the upper right electrode 32 by an air bridge wiring 28, and the rightmost LED 1 in the second row is connected to the lower right electrode 32 by an air bridge wiring 28. As can be seen from FIG. 11, also in this example, the two LED arrays are connected to the electrode 32 in parallel with each other and connected to have opposite polarities. Therefore, when the AC power is supplied, the two LED arrays emit light alternately.

  The common features of the two-dimensional patterns of FIGS. 6, 8, and 10 are that each LED 1 has a substantially square shape and size, and the two electrodes (pads) are also substantially square and are not formed adjacent to each other. It is a combination of two LED arrays (separately formed), the two LED arrays are bent and formed to cross each other on the chip, and the two LED arrays have opposite polarities Connected to the electrode, and so on.

  FIG. 12 shows an example in which LEDs having a triangular planar shape are two-dimensionally arranged, and FIG. 13 shows a circuit diagram thereof. In FIG. 12, a total of six LEDs 1a, 1b, 1c, 1d, 1e, and 1f are formed so that the planar shape thereof is a triangular shape. The LED 1a and the LED 1e are arranged so as to be substantially square with two facing one side of the triangle, and the LEDs 1b and 1f are arranged so as to be substantially square with two facing each other. Further, the LED 1d and the electrode 32 are connected to face each other, and the LED 1c and the electrode 32 are connected to face each other. The two electrodes 32 have a triangular shape in the same manner as the LED, and are arranged so as to be substantially square. The opposing sides of the LEDs constitute an n-electrode 24, that is, the two opposing LEDs share the n-electrode 24. The LED and the electrode 32 are also n-electrode connected. Also in this arrangement, a total of six LEDs are divided into two sets as in the example described above. One LED array is an array composed of LED 1a, LED 1b, and LED 1c. The p electrode 22 of the LED 1a is connected to the electrode 32 by an air bridge wiring 28, and the n electrode 24 is connected to the p electrode 22 of the LED 1b and the air bridge wiring 28. Connected. The n-electrode 24 of the LED 1 b is connected to the p-electrode 22 of the LED 1 c by an air bridge wiring 28. The n electrode 24 of the LED 1 c is connected to the electrode 32. The other LED array is composed of LED 1d, LED 1e, and LED 1f. The electrode 32 and the p electrode 22 of the LED 1f are connected by an air bridge wiring 28, and the n electrode 24 of the LED 1f is connected by a p electrode 22 of the LED 1e and an air bridge wiring 28. Then, the n electrode 24 of the LED 1 e and the p electrode 22 of the LED 1 d are connected by an air bridge wiring 28, and the n electrode 24 of the LED 1 d is connected to the electrode 32.

  In FIG. 13, the LED 1a constituting one LED array and the n electrode of the LED 1e constituting the other LED array are connected, and the LED 1b constituting the one LED array and the n electrode of the LED 1f constituting the other LED array. Note also that is connected. By sharing some n-electrodes of the two sets of LED arrays, circuit wiring can be reduced. Also in this example, the two LED arrays are connected in parallel to the electrode 32 and are connected to have opposite polarities. In addition, each LED has the same shape and size, and each LED is opposed to one side and the electrode 32 is also formed in a triangular shape, so that the LEDs and electrodes can be formed at a high density to reduce the necessary substrate area. it can.

  FIG. 14 shows another example in which LEDs having a triangular planar shape are two-dimensionally arranged, and FIG. 15 shows a circuit diagram thereof. In this example, a total of 16 LEDs 1a to 1r are two-dimensionally formed. LEDs 1a and 1j, 1b and 1k, 1c and 1m, 1d and 1n, 1e and 1p, 1f and 1q, 1g and 1r face each other on one side of the triangle. An n-electrode 24 is commonly formed on the opposite sides. Further, the LED 1i and the electrode 32 face each other, and the LED 1h and the electrode 32 face each other. One LED array is composed of LEDs 1a, 1b, 1c, 1d, 1e, 1f, 1g, 1h, and the other LED array is composed of LEDs 1r, 1q, 1p, 1n, 1m, 1k, 1j, 1i. The n electrode 24 of the LED 1b is connected to the p electrode 22 of the LED 1c by the air bridge wiring 28, and the n electrode 24 of the LED 1e is also connected to the p electrode 22 of the LED 1f by the air bridge wiring 28. The n electrode 24 of the LED 1q is also connected to the p electrode 22 of the LED 1p by the air bridge wiring 28, and the n electrode 24 of the LED 1m is also connected to the p electrode 22 of the LED 1k by the air bridge wiring 28. In FIG. 14, a crossover portion is generated as in FIG. 12, but a short circuit can be avoided by the air bridge wiring 28. Also in this example, necessary wiring is reduced by making some n electrodes 24 of the two sets of LED arrays have a common structure. Also in this example, the two LED arrays are connected in parallel to the electrodes 32 with opposite polarities, and can be driven by alternating current. Although FIG. 12 shows a case of a total of 6 LEDs and FIG. 14 shows a case of a total of 16 LEDs, other numbers of LEDs can be similarly two-dimensionally arranged. The applicant of the present application has also created a light emitting device in which 38 LEDs are two-dimensionally arranged.

  Although the case of AC driving has been described above, it goes without saying that DC driving is also possible. In this case, the LED array may be connected in the forward direction according to the polarity direction of the DC power supply, instead of connecting the LED array to the electrodes so as to have opposite polarities. High voltage driving is possible by connecting a plurality of LEDs in series. Hereinafter, the case of direct current drive will also be described.

  FIG. 16 shows an example in which two LEDs are connected in series, and FIG. 17 shows a circuit diagram thereof. Each LED 1 has a rectangular planar shape, and the two LEDs are connected by an air bridge wiring 28. The electrode 32 is formed in the vicinity of each LED 1, and the electrode 32 and the LED 1 form a rectangular region. That is, the electrode 32 occupies a part of the rectangular area, and the LED 1 is formed in another area of the rectangular area.

  FIG. 18 shows an example in which a total of four LEDs are two-dimensionally arranged, and FIG. 19 shows a circuit diagram thereof. LED1 of FIG. 16 is divided | segmented into two, and each is connected in parallel. It can also be said that two sets of LED arrays composed of two LEDs are connected in a forward direction in parallel. The LEDs 1a and 1b constitute one LED array, and the LEDs 1c and 1d constitute another LED array. LED 1a and LED 1c share the p electrode 22 and n electrode 24, and LED 1b and LED 1d also share the p electrode 22 and n electrode 24. According to this configuration, there is an effect that the current becomes uniform as compared with FIG.

  FIG. 20 shows an example in which a total of three LEDs are two-dimensionally arranged, and FIG. 21 shows a circuit diagram thereof. The LEDs 1a, 1b and 1c are not the same shape, and an electrode 32 is formed on a part of the LED 1a. The n electrode 24 of the LED 1a and the p electrode of the LED 1b are connected by an air bridge wiring 28 that straddles the LED 1b. By devising the shape and arrangement of each LED, the appearance of the entire light emitting device (chip) can be substantially square even with three LEDs.

  FIG. 22 shows an example in which a total of six LEDs are two-dimensionally arranged, and FIG. 23 shows a circuit diagram thereof. Each LED 1a-1f is the same shape and the same size. The LEDs 1a to 1f are connected in series. The LEDs 1a to 1c are arranged on a straight line, and the LEDs 1d to 1f are arranged on another straight line. The LED 1c and the LED 1d are connected by an air bridge wiring 28. Also in this example, the overall shape of the chip can be made substantially square.

  FIG. 24 shows an example in which a total of five LEDs are two-dimensionally arranged, and FIG. 25 shows a circuit diagram thereof. The LEDs 1a to 1e have the same shape (rectangular shape) and the same size. Also in this example, the overall shape can be made substantially square.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to this, A various change is possible. In particular, the pattern in the case where a plurality of light emitting elements (LEDs, etc.) are two-dimensionally arranged is possible in addition to the patterns described above. In this case, the electrodes are shared between adjacent light emitting elements to reduce wiring, the overall shape is square or rectangular, a plurality of sets of light emitting element arrays are connected in parallel to the electrodes, and plural in the case of AC drive. It is preferable that the sets of light emitting element arrays have opposite polarities, the plurality of sets of light emitting element arrays are combined in a zigzag manner, and the like.

  26 to 31 illustrate some of these modifications. FIG. 26 shows a two-dimensional arrangement in the case of AC driving, in which a total of 40 LEDs are arranged. FIG. 27 is a circuit diagram thereof. The difference from FIG. 6 is that some of the two sets of LED arrays share the n-electrode 24 (see FIG. 5). For example, the n electrode 24 of the LED located second from the right end of the first column of one LED array (indicated by α in the figure) is the LED (β in the figure) located at the right end of the first column of the other LED array. And the n-electrode 24 shown in FIG. In addition, the air bridge wiring 28 in the edge part (gamma part in a figure) of a LED array is formed in common, without making it cross.

  FIG. 28 shows a two-dimensional arrangement in the case of AC driving, in which a total of 14 LEDs are arranged. FIG. 29 is a circuit diagram thereof. A difference from FIG. 10 is that some of the two sets of LED arrays share the n-electrode 24. For example, the n electrode 24 of the leftmost LED (indicated by α in the figure) of the first column of one LED array is the second LED from the right end of the first column of the other LED array (indicated by β in the figure). ) N electrode 24. In addition, the air bridge wiring 28 at the end (γ portion in the figure) is formed in common.

  FIG. 30 shows a two-dimensional arrangement in the case of AC driving, in which a total of six LEDs are arranged. FIG. 31 is a circuit diagram thereof. Also in this example, the air bridge wiring 28 at the end portion (γ portion) is formed in common. In this configuration as well, it can be said that the n electrode 24 in one LED array and the n electrode 24 in the other LED array are shared.

It is a basic lineblock diagram of a light emitting element (LED). It is an equivalent circuit diagram of a light-emitting device. It is a top view of two LED. It is IV-IV sectional drawing of FIG. It is another equivalent circuit schematic of a light-emitting device. It is explanatory drawing which arranged 40 LED two-dimensionally. FIG. 7 is a circuit diagram of FIG. 6. It is explanatory drawing which arranged six LED two-dimensionally. FIG. 9 is a circuit diagram of FIG. 8. It is explanatory drawing which arranged 14 LED two-dimensionally. FIG. 11 is a circuit diagram of FIG. 10. It is explanatory drawing which arranged six LED two-dimensionally. FIG. 13 is a circuit diagram of FIG. 12. It is explanatory drawing which arranged 16 LED two-dimensionally. FIG. 15 is a circuit diagram of FIG. 14. It is explanatory drawing which arranged two LED. FIG. 17 is a circuit diagram of FIG. 16. It is explanatory drawing which arranged four LED two-dimensionally. FIG. 19 is a circuit diagram of FIG. 18. It is explanatory drawing which arranged three LED in two dimensions. FIG. 21 is a circuit diagram of FIG. 20. It is explanatory drawing which arranged six LED two-dimensionally. FIG. 23 is a circuit diagram of FIG. 22. It is explanatory drawing which arranged two LED two-dimensionally. FIG. 25 is a circuit diagram of FIG. 24. It is another two-dimensional arrangement explanatory drawing. FIG. 27 is a circuit diagram of FIG. 26. It is another two-dimensional arrangement explanatory drawing. FIG. 29 is a circuit diagram of FIG. 28. It is another two-dimensional arrangement explanatory drawing. FIG. 31 is a circuit diagram of FIG. 30.

Explanation of symbols

10 Substrate (wafer)
12 u-GaN layer 14 n-type GaN layer 16 InGaN light emitting layer 18 AlGaN layer 20 p-GaN layer 22 p-electrode 24 n-electrode

Claims (19)

A light-emitting device in which a plurality of GaN-based light-emitting diode elements are formed on an insulating substrate,
The plurality of light emitting diode elements are arranged in a matrix on the insulating substrate,
The plurality of light emitting diode elements are connected in parallel to two AC power supply electrodes so as to be electrically divided into a first set and a second set as opposite polarities,
The first set of light emitting diode elements includes a first light emitting diode element row and a second light emitting diode element row, and the second set of light emitting diode elements is a third light emitting diode element row. A fourth row of light emitting diode elements, wherein the third light emitting diode element row is disposed between the first light emitting diode element row and the second light emitting diode element row,
An electrode of a light emitting diode element at one end of the matrix array of the first light emitting diode element row, and a light emitting diode at an end of the first light emitting diode element row on the one side side The electrode of the element, the electrode of the light emitting diode element at the end of the one side of the column of the third light emitting diode element, and the light emitting diode of the edge of the side of the fourth light emitting diode element is shared and the device electrodes are electrically connected, and the light emitting device wherein a directly to two AC power supply electrode, wherein no Tei connected. The apparatus of claim 1.
The electrode of the light emitting diode element at the end of the column of the first light emitting diode element and the electrode of the light emitting diode element at the end of the column of the fourth light emitting diode element have the same polarity, and the second light emission A light emitting device, wherein the electrode of the light emitting diode element at the end of the row of diode elements and the electrode of the light emitting diode element at the end of the third light emitting diode element have the same polarity. The apparatus of claim 1.
The electrode of the light emitting diode element at the end of the column of the first light emitting diode element and the electrode of the light emitting diode element at the end of the column of the second light emitting diode element have opposite polarities, and the third light emission A light emitting device characterized in that the electrode of the light emitting diode element at the end of the row of diode elements and the electrode of the light emitting diode element at the end of the fourth light emitting diode element have opposite polarities. The apparatus of claim 1.
2. The light emitting device according to claim 2, wherein the two AC power supply electrodes are arranged at opposite ends of the matrix-shaped diagonal line. The apparatus of claim 1.
The two AC power supply electrodes are disposed at both ends of one side of the matrix-shaped end portion. The apparatus of claim 1.
The two AC power supply electrodes and the plurality of light emitting diode elements each have a planar shape substantially the same shape and the same size. The apparatus of claim 1.
The two AC power supply electrodes and the plurality of light emitting diode elements have a substantially square planar shape and are arranged in a matrix. The apparatus of claim 1.
All the light emitting diode elements which comprise the said 1st group are connected in series between the electrodes for two alternating current power supplies, The light emitting device characterized by the above-mentioned. The apparatus of claim 8.
All the light emitting diode elements which comprise the 2nd set are connected in series between two electrodes for alternating current power supplies, The light-emitting device characterized by the above-mentioned. The apparatus of claim 1.
A light-emitting diode in which the negative electrode of any one of the light-emitting diode elements constituting the first column is adjacent to the light-emitting diode element among the light-emitting diode elements constituting the third column A light-emitting device that is shared with and electrically connected to a negative electrode of an element. The apparatus of claim 1.
The first electrode of the light emitting diode element constituting the second column and the first electrode of the light emitting diode element constituting the second column at the end on one side of the arrangement of the light emitting diode elements constituting the first column on the matrix. A second electrode of the light emitting diode element at the end on the side, a third electrode of the light emitting diode element at the end on the one side of the light emitting diode elements constituting the third row, and the first electrode The fourth electrode of the light emitting diode element at the end of the one side of the light emitting diode elements constituting the four columns is shared and electrically connected, and the first electrode and the fourth electrode Are the same polarity, the second electrode and the third electrode have the same polarity, and the polarities of the first electrode, the fourth electrode, the second electrode, and the third electrode Are different from each other. The apparatus of claim 11.
The first set of light emitting diode elements further includes a fifth row of light emitting diode elements;
The second set of light emitting diode elements further includes a column of sixth light emitting diode elements;
The fourth light emitting diode element row is disposed between the second light emitting diode element row and the fifth light emitting diode element row,
The fifth light emitting diode element row is disposed between the fourth light emitting diode element row and the sixth light emitting diode element row,
5th electrode of the light emitting diode element of the edge | side part opposite to 1 side of arrangement | positioning on the said matrix of the light emitting diode element which comprises the said 2nd row | line | column, and the light emitting diode which comprises the said 4th row | line | column The sixth electrode of the light emitting diode element at the end on the opposite side of the element and the seventh light emitting diode element at the end on the opposite side of the light emitting diode elements constituting the fifth column. And the eighth electrode of the light emitting diode element at the end on the opposite side of the light emitting diode elements constituting the sixth column are respectively shared and electrically connected, and the 2 The AC power supply electrodes are not directly connected, the fifth electrode and the eighth electrode have the same polarity, and the sixth electrode and the seventh electrode have the same polarity And the fifth electrode and the eighth electrode and the front Emitting device the polarity of the sixth electrode and the seventh electrode is characterized different. The apparatus of claim 12.
The light emitting device according to claim 10, wherein the row of elements of each light emitting diode is individually arranged on a straight line on the insulating substrate. The apparatus of claim 11.
The light emitting device, wherein the first electrode, the second electrode, the third electrode, and the fourth electrode are shared and electrically connected by an air bridge wiring. The apparatus of claim 12.
The first electrode, the second electrode, the third electrode, and the fourth electrode are shared and electrically connected by a first air bridge wiring;
The light emission characterized in that the fifth electrode, the sixth electrode, the seventh electrode, and the eighth electrode are shared and electrically connected by a second air bridge wiring. apparatus. The apparatus of claim 15.
A light emitting device characterized in that a first air bridge wiring and a second air bridge wiring are arranged at both ends of the insulating substrate. The apparatus of claim 1.
The plurality of light emitting diode elements have a triangular plane shape,
A light emitting diode element adjacent to one of the light emitting diode elements of the light emitting diode elements constituting the first set and the light emitting diode element of the light emitting diode elements constituting the second set is: A light-emitting device characterized by being arranged so that a planar shape is substantially square by facing one side of a triangle and sharing a negative electrode on the facing side. The apparatus according to any one of claims 1 to 17,
The light emitting device, wherein the first set of light emitting diode elements and the second set of light emitting diode elements are alternately arranged in a zigzag shape. The device according to any one of claims 1 to 18,
The light-emitting device, wherein the plurality of light-emitting diode elements are integrally formed.

Images