JP4848464B2 - Method for manufacturing light emitting device - Google Patents

Description

This invention relates to the production how the light-emitting device.

  Conventionally, as a light emitting device, as shown in FIG. 45, one (or several) LED chips 910 are mounted on a package substrate 900 on which a lead frame 901 is mounted, and an n-type electrode 905 of the LED chip 910 After the p-type electrode 906 is connected to the lead frame 901 by the bonding wire 911, a resin 922 containing a phosphor is filled on the LED chip 910 surrounded by the reflector 921, and further on the resin 922 containing the phosphor. Some are filled with a transparent resin 923 (see, for example, Non-Patent Document 1). In the LED chip 910, a semiconductor layer 903 made of GaN is stacked on a sapphire substrate 902, and the semiconductor layer 903 has an active layer 904.

  In the manufacturing method of the light emitting device, since the wiring process after mounting one (or several) LED chips 910 on the package substrate 900 is individually performed for one package, the cost increases. is there.

  Further, in the light emitting device on which the one (or several) LED chips are mounted, the variation in the brightness for each LED chip becomes the variation in the brightness of the light emitting device as it is, so that the yield of the light emitting device is poor. There is.

Motomura Murakami, “13th Transition of Semiconductor Package Technology for LED / LD”, Semiconductor FPD World, Press Journal, May 2009, p. 114-117 (Figure 5)

  Accordingly, an object of the present invention is to provide a method of manufacturing a light emitting device capable of reducing manufacturing costs by wiring a plurality of light emitting elements arranged on the same substrate in a lump, reducing characteristic variation, and improving yield. An object of the present invention is to provide a light emitting device manufactured by a method for manufacturing a light emitting device.

  Another object of the present invention is to provide an illuminating device that can reduce the manufacturing cost, reduce the characteristic variation, and improve the yield.

  Another object of the present invention is to provide a backlight capable of reducing the manufacturing cost, reducing the characteristic variation, and improving the yield.

  Another object of the present invention is to provide a liquid crystal panel capable of reducing the manufacturing cost, reducing the characteristic variation, and improving the yield.

In order to solve the above problems, a method for manufacturing a light-emitting device according to a first aspect of the present invention includes:
An arrangement step of arranging a plurality of light emitting elements on the same substrate;
A wiring step of wiring a part or all of the plurality of light emitting elements arranged on the substrate in a lump;
A substrate dividing step of forming a plurality of light emitting devices in which a plurality of light emitting elements are arranged on the divided substrate by dividing the substrate into a plurality of divided substrates after the arranging step and the wiring step ;
The plurality of light emitting elements are rod-shaped,
The plurality of light emitting elements are arranged on the mounting surface of the substrate so that the longitudinal direction of the plurality of light emitting elements is parallel to the mounting surface of the substrate,
The rod-shaped light emitting element includes a first-conductivity-type rod-shaped semiconductor core, a second-conductivity-type tubular semiconductor layer covering the outer periphery of the semiconductor core, and a tubular shape concentrically surrounding the rod-shaped semiconductor core. A light emitting surface,
One end side of the semiconductor core of the rod-like light emitting element is exposed .

According to the above configuration, after the plurality of light emitting elements arranged on the same substrate are collectively wired, the substrate is divided into the plurality of divided substrates, and the light emitting device in which the plurality of light emitting elements are arranged on the divided substrates. By forming a plurality of layers, the wiring process can be simplified and the manufacturing cost can be reduced. Further, when n light emitting elements having X% brightness variation are assembled, the overall brightness variation is Y = X / √n [%], so that the characteristic variation can be reduced and the yield can be improved. .
Further, by arranging the plurality of light emitting elements on the mounting surface of the substrate so that the longitudinal direction of the plurality of rod-shaped light emitting elements is parallel to the mounting surface of the substrate, the axial direction (longitudinal direction relative to the radial direction) Since the ratio of the length of the (direction) can be increased, the heat flow in the lateral direction to the substrate side is more efficient than when the light-emitting surface is a flat square under the same conditions of the light-emitting surface of the light-emitting element. Temperature rise is further suppressed, and a longer life and higher efficiency can be achieved.
Further, since the rod-shaped light emitting element has a cylindrical light emitting surface that concentrically surrounds the rod-shaped core, the light emitting surface per light emitting element is larger than a light emitting element having a flat light emitting surface with the same volume. The area is increased, the number of light emitting elements for obtaining a predetermined brightness can be reduced, and the cost can be reduced.
The rod-shaped light emitting element has a first conductivity type rod-shaped semiconductor core and a second conductivity type cylindrical semiconductor layer covering the outer periphery of the semiconductor core, and one end side of the semiconductor core is exposed. This makes it possible to connect one electrode to the exposed portion on one end side of the semiconductor core, connect the electrode to the semiconductor layer on the other end side of the semiconductor core, connect the electrodes to both ends, and connect to the semiconductor layer. Since the electrode to be connected and the exposed portion of the semiconductor core are prevented from being short-circuited, wiring can be facilitated.

Further, in the method for manufacturing a light emitting device of an embodiment,
In the arrangement step, the plurality of light emitting elements are collectively arranged on the same substrate.

  According to the embodiment, in the arrangement step, a plurality of light emitting elements are collectively arranged on the same substrate, so that the manufacturing cost can be further reduced in combination with the simplification of the wiring step.

Further, in the method for manufacturing a light emitting device of an embodiment,
A wiring pattern for wiring the plurality of light emitting elements is formed on the substrate,
The wiring pattern is not formed in the cutting area of the substrate in the substrate dividing step.

  According to the above embodiment, since the wiring pattern formed for wiring the plurality of light emitting elements on the substrate is not formed in the cutting region of the substrate in the substrate dividing step, conductive wiring scraps are generated at the time of cutting. It does not scatter and can prevent problems such as a short circuit due to conductive wiring debris.

Further, in the method for manufacturing a light emitting device of an embodiment,
A wiring pattern for wiring the plurality of light emitting elements is formed on the substrate,
The wiring pattern that does not affect the electrical connection even if the substrate is cut in the substrate dividing step is formed in the cutting region of the substrate.

  According to the above-described embodiment, the wiring pattern is continuously formed across the adjacent divided substrates by forming the wiring pattern in the substrate cutting region that does not affect the electrical connection even if it is cut in the substrate dividing step. In addition, the wiring pattern can be easily formed, and there is no problem in circuit operation even if the wiring pattern is cut.

Further, in the method for manufacturing a light emitting device of an embodiment,
The light emitting element is not arranged in the substrate cutting region in the substrate dividing step.

  According to the above embodiment, by not arranging the light emitting elements in the substrate cutting region in the substrate dividing step, the light emitting elements that are damaged by the cutting can be eliminated, and the light emitting elements can be used effectively.

Further, in the method for manufacturing a light emitting device of an embodiment,
Among the plurality of light-emitting elements, a light-emitting element that does not affect a desired light emission amount even when cut in the substrate dividing step is disposed in the cutting region of the substrate.

  According to the embodiment, among the plurality of light emitting elements, the light emitting element that does not affect the desired light emission amount even if it is cut in the substrate dividing step is disposed in the cutting region of the substrate. Even if the element does not emit light, light is emitted by a plurality of other light-emitting elements that are not cut. Therefore, it is not necessary to consider that the light emitting element is not arranged in the cutting region of the substrate in the arrangement process, and the arrangement process can be simplified.

Further, in the method for manufacturing a light emitting device of an embodiment,
A phosphor coating step of coating a phosphor on the substrate after the placement step and the wiring step and before the substrate dividing step;
A protective film coating step of coating a protective film on the substrate after the phosphor coating step.

  According to the above embodiment, the phosphor coating process for coating the phosphor on the substrate after the placement process and the wiring process and before the substrate dividing process, and the protection on the substrate after the phosphor coating process. By performing the protective film coating process for coating the film at once on one substrate on which a plurality of light emitting elements are arranged, the manufacturing cost can be greatly reduced as compared with the case where the conventional process is performed for each package.

Further, in the method for manufacturing a light emitting device of an embodiment,
In the phosphor applying step, the phosphor is selectively applied to a region where the plurality of light emitting elements are arranged.

  According to the embodiment, by selectively applying the phosphor to the region where the plurality of light emitting elements are arranged, the usage amount of the phosphor, which accounts for a large proportion of the material cost, can be reduced and the cost can be reduced.

Further, in the method for manufacturing a light emitting device of an embodiment,
100 or more of the light emitting elements are arranged on each of the divided substrates.

  According to the above embodiment, by arranging 100 or more light emitting elements on each of the divided substrates, the variation in overall brightness when a plurality of light emitting elements having brightness variations are gathered is reduced for one light emitting element. It can be reduced to 1/10 or less of the brightness variation.

  Usually, the brightness variation for each light emitting element may reach 50% due to the variation of the forward voltage (Vf). Conventionally, light emitting elements that are out of specs by lighting tests are eliminated, or light emitting elements having similar brightness are grouped and used. However, when n light emitting elements having a brightness variation of X% are assembled, the overall brightness variation is Y = X / √n [%]. That is, when n = 100, even if each light emitting element has a variation of 50%, the variation in overall brightness is 5% of 1/10, and the specification can be satisfied. Thereby, the lighting test of each light emitting element becomes unnecessary, and cost can be reduced.

Further, in the method for manufacturing a light emitting device of an embodiment,
In the substrate dividing step, the substrate is divided into at least two types of divided substrates having different shapes.

  According to the above embodiment, in the substrate dividing step, the substrate is divided into at least two types of divided substrates having different shapes, whereby light emitting devices corresponding to various forms can be easily provided.

Further, in the method for manufacturing a light emitting device of an embodiment,
The arranging step of arranging the plurality of light emitting elements on the substrate includes
A substrate creating step of creating the substrate having at least a first electrode and a second electrode on a mounting surface;
An application step of applying a solution containing the plurality of light emitting elements on the substrate;
An arrangement step of applying a voltage to at least the first electrode and the second electrode, and arranging the plurality of light emitting elements at least at positions defined by the first electrode and the second electrode. .

  According to the embodiment, a substrate having at least a first electrode and a second electrode on a mounting surface is created, and a liquid containing a plurality of light emitting elements is applied on the substrate. Thereafter, a voltage is applied to at least the first electrode and the second electrode, and the plurality of light emitting elements are arranged at positions defined by at least the first electrode and the second electrode. Accordingly, the plurality of light emitting elements can be easily arranged at predetermined positions on the substrate. Therefore, it is not necessary to arrange each light emitting diode at a predetermined position on the substrate as in the prior art, and a large number of fine light emitting diodes can be accurately disposed at a predetermined position.

Further, in the method for manufacturing a light emitting device of an embodiment,
At least the first electrode and the second electrode are used as electrodes for driving the plurality of light emitting elements.

  According to the embodiment, by using at least the first electrode and the second electrode as electrodes for driving a plurality of light emitting elements, the wiring process can be simplified and the cost can be reduced.

Further, in the method for manufacturing a light emitting device of an embodiment,
The plurality of light emitting elements are a plurality of elements formed on an epitaxial substrate, and each element is separated from the epitaxial substrate.

  According to the above embodiment, by forming a plurality of elements formed on the epitaxial substrate and using the plurality of light emitting elements separated from the epitaxial substrate, the epitaxial substrate is divided and used together with the light emitting elements. In comparison, since the epitaxial substrate can be reused, the cost can be reduced.

In the light emitting device of the second invention,
A divided substrate divided from one substrate;
A plurality of light emitting diodes arranged on the divided substrate;
A first electrode and a second electrode, which are formed on the divided substrate with a predetermined interval and to which the plurality of light emitting diodes are connected,
The plurality of light emitting diodes include a light emitting diode having an anode connected to the first electrode and a cathode connected to the second electrode, and a cathode connected to the first electrode and the second electrode. A light-emitting diode with an anode connected to the electrode is mixed,
The plurality of light emitting diodes are driven by applying an AC voltage between the first electrode and the second electrode by an AC power source.

  According to the above configuration, since it is not necessary to arrange the plurality of light emitting diodes connected between the first and second electrodes with the same polarity, a step of aligning the polarities (directions) of the plurality of light emitting diodes is not required during manufacturing. The process can be simplified. In addition, it is not necessary to provide a mark on the light emitting diode to identify the polarity (direction) of the light emitting diode, and it is not necessary to make the light emitting diode in a special shape for polarity identification, thus simplifying the manufacturing process of the light emitting diode. And manufacturing costs can be reduced. In addition, when the size of the light emitting diode is small or the number of light emitting diodes is large, the arrangement process can be greatly simplified as compared with the case where the light emitting diodes are arranged with the same polarity.

In the light emitting device of one embodiment,
The divided substrate is mounted on a heat sink.

  According to the said embodiment, the heat dissipation effect improves further by attaching a division board | substrate on a heat sink.

In the lighting device of the third invention,
The light-emitting device is provided.

  According to the above configuration, by using the light emitting device, manufacturing cost can be reduced, characteristic variation can be reduced, and yield can be improved.

In the backlight of the fourth invention,
The light-emitting device is provided.

  According to the above configuration, by using the light emitting device, manufacturing cost can be reduced, characteristic variation can be reduced, and yield can be improved.

In the liquid crystal panel of the fifth invention,
The light-emitting device is provided.

  According to the above configuration, by using the light emitting device, manufacturing cost can be reduced, characteristic variation can be reduced, and yield can be improved.

In the liquid crystal panel of the sixth invention,
A transparent substrate;
A plurality of light emitting elements disposed on one surface of the transparent substrate and connected to wiring formed on one surface of the transparent substrate;
And a plurality of thin film transistors formed on the other surface of the transparent substrate.

  According to the said structure, while using a transparent substrate which united the liquid crystal panel substrate and the backlight substrate, while being able to reduce component cost and manufacturing cost, a thinner liquid crystal panel can be obtained.

In the liquid crystal panel of the seventh invention,
A transparent substrate;
A plurality of light emitting elements disposed on one surface of the transparent substrate and connected to wiring formed on one surface of the transparent substrate;
And a color filter formed on the other surface of the transparent substrate.

  According to the said structure, while using a transparent substrate which combined the color filter and the backlight board | substrate into one, while being able to reduce component cost and manufacturing cost, a thinner liquid crystal panel can be obtained.

  As is clear from the above, according to the method for manufacturing a light emitting device, the light emitting device, the illumination device, the backlight, and the liquid crystal panel of the present invention, the manufacturing cost can be reduced, the characteristic variation can be reduced, and the yield can be improved.

FIG. 1 is a process diagram of a method for manufacturing a first light-emitting element used in the light-emitting device according to the first embodiment of the present invention. FIG. 2 is a process diagram following FIG. FIG. 3 is a process diagram following FIG. FIG. 4 is a process diagram of a method for manufacturing a second light emitting element used in the light emitting device according to the first embodiment of the present invention. FIG. 5 is a process diagram following FIG. FIG. 6 is a process diagram following FIG. FIG. 7 is a process diagram following FIG. FIG. 8 is a process diagram following FIG. FIG. 9 is a process diagram following FIG. FIG. 10 is a process diagram following FIG. FIG. 11 is a process diagram following FIG. FIG. 12 is a process diagram following FIG. FIG. 13 is a process diagram following FIG. FIG. 14 is a process diagram following FIG. FIG. 15 is a process diagram following FIG. FIG. 16 is a process diagram following FIG. FIG. 17 is a process diagram following FIG. FIG. 18 is a plan view of an insulating substrate used in the light emitting device according to the first embodiment of the present invention. 19 is a schematic sectional view taken along line XIX-XIX in FIG. FIG. 20 is a view for explaining the principle of arranging the rod-shaped structure light emitting elements. FIG. 21 is a diagram for explaining the potential applied to the electrodes when the rod-shaped structure light emitting elements are arranged. FIG. 22 is a plan view of an insulating substrate on which the rod-shaped structure light emitting elements are arranged. FIG. 23 is a process diagram of another method for manufacturing a light-emitting device according to the first embodiment of the present invention. FIG. 24 is a process diagram following FIG. FIG. 25 is a process diagram following FIG. FIG. 26 is a process diagram of another method for manufacturing a light-emitting device according to the first embodiment of the present invention. FIG. 27 is a process diagram following FIG. FIG. 28 is a process diagram following FIG. FIG. 29 is a process diagram following FIG. FIG. 30 is a process drawing following FIG. FIG. 31 is a diagram for explaining a substrate dividing step in the method for manufacturing the light emitting device according to the first embodiment of the present invention. FIG. 32 is a plan view of a light emitting device used in the illumination device according to the second embodiment of the present invention. FIG. 33 is a side view of the light emitting device. FIG. 34 is a side view of an LED bulb as an example of an illumination device using the light emitting device. FIG. 35 is a plan view of a backlight using the light emitting device according to the third embodiment of the present invention. FIG. 36 is a plan view of a backlight using the light emitting device according to the fourth embodiment of the present invention. FIG. 37 is a plan view and a side view of a liquid crystal panel using the light emitting device of the fifth embodiment of the present invention. FIG. 38 is a side view and an end view of a rod-shaped structure light emitting element used in a method for manufacturing a light emitting device according to another embodiment of the present invention. FIG. 39 is a diagram showing a step of applying a solution containing a rod-shaped structure light emitting element on the insulating substrate in the method for manufacturing the light emitting device. FIG. 40 is a diagram showing a process of rubbing the solution applied on the insulating substrate. FIG. 41 is a diagram showing a process of drying the rubbed insulating substrate. FIG. 42 is a diagram showing a process of exposing a part of the p-type semiconductor core by etching a linear region orthogonal to the longitudinal direction of the rod-shaped structure light emitting element of the insulating substrate on which the rod-shaped structure light emitting elements are arranged. is there. FIG. 43 is a diagram showing a process of forming metal wiring on the insulating substrate. FIG. 44 is a side view of a liquid crystal panel using a light emitting device according to another embodiment of the present invention. FIG. 45 is a cross-sectional view of a conventional light emitting device.

Hereinafter will be described in detail by embodiments thereof illustrated in the manufacture how the light-emitting device of the present invention. In this embodiment, Si-doped n-type GaN and Mg-doped p-type GaN are used in the light emitting element, but the impurity doped in GaN is not limited to this.

[First Embodiment]
In the description of the first embodiment of the present invention, first, as a method for manufacturing a light-emitting device and a light-emitting element used in the light-emitting device, in the following (1), a method for manufacturing a first light-emitting element (shown in FIGS. 1 to 3). In (2), the manufacturing method of the second light emitting element (shown in FIGS. 4 to 17) is described, and in (3) to (5), the arrangement of the light emitting elements on the same substrate is described. After describing the process and the wiring process, the substrate dividing process (shown in FIG. 31) will be described in (6).

(1) First Light-Emitting Element Manufacturing Method FIGS. 1 to 3 show process diagrams of a first light-emitting element manufacturing method used in the light-emitting device according to the first embodiment of the present invention. Below, the manufacturing method of a 1st light emitting element is demonstrated with reference to FIGS. 1-3.

First, as shown in FIG. 1, the n-type GaN layer 1 is formed on the n-type GaN substrate 20. A rod-shaped n-type GaN crystal is grown using an MOCVD (Metal Organic Chemical Vapor Deposition) apparatus. This rod-shaped n-type GaN 1 has a growth temperature set to about 700 ° C. to 800 ° C., uses trimethyl gallium (TMG) and ammonia (NH ₃ ) as growth gases, and supplies silane (SiH ₄ ) for supplying n-type impurities. Further, by supplying hydrogen (H ₂ ) as a carrier gas, the n-type GaN layer 1 having Si as an impurity can be grown. On the other hand, when GaN is grown at a low temperature (for example, 600 ° C. or lower) or at a high temperature (for example, 1000 ° C. or higher), the formed GaN grows in an upward direction in a tapered shape at a low temperature. In addition, when the temperature is high, the formed GaN grows sideways and becomes a thin film instead of a rod.

Next, an InGaN quantum well layer 2 is grown on the n-type GaN layer 1 as shown in FIG. The quantum well layer 2 has an n-type GaN layer by setting the temperature to 750 ° C. according to the emission wavelength, supplying nitrogen (N ₂ ) as the carrier gas, TMG, NH ₃ , and trimethylindium (TMI) as the growth gas. A quantum well layer 2 made of p-type InGaN can be formed on 1. In this quantum well layer, a p-type AlGaN layer may be inserted as an electron blocking layer between the InGaN layer and the p-type GaN layer. Alternatively, a multiple quantum well structure in which GaN barrier layers and InGaN quantum well layers are alternately stacked may be employed.

Next, a p-type GaN layer 3 is formed on the InGaN quantum well layer 2. The p-type GaN layer 3 can be formed by setting the set temperature to 800 ° C., using TMG and NH ₃ as growth gases, and using Cp ₂ Mg for supplying p-type impurities.

  Next, as shown in FIG. 3, by applying ultrasonic vibration to a plurality of rod-shaped structure light-emitting elements 10 composed of an n-type GaN layer 1, a quantum well layer 2, and a p-type GaN layer 3 in a solution such as IPA. The plurality of rod-shaped structure light emitting elements 10 are separated from the substrate.

  In the first light emitting element manufacturing method used in the light emitting device of the first embodiment, a plurality of elements formed on the n-type GaN substrate 20 which is an epitaxial substrate are formed, and the n-type GaN substrate 20 is used. By using the plurality of separated rod-shaped structure light emitting elements 10, the n-type GaN substrate 20 can be reused as compared with the case where the substrate is divided and used together with the light emitting elements, so that the cost can be reduced.

  In this embodiment, the rod-shaped light-emitting element 10 is used as the rod-shaped light-emitting element. However, the rod-shaped light-emitting element is not limited to this. For example, a growth mask having a growth hole on the n-type GaN substrate or a metal seed is used. A plurality of rod-shaped light emitting elements may be grown and then separated from the substrate.

  In the first embodiment, a rod-like light emitting element is used. However, the light emitting element of the present invention is not limited to this, and has a flat light emitting surface such as a circular shape, an elliptical shape, a square shape, a rectangular shape, or a polygonal shape. The light emitting element may be arranged on the mounting surface so that the light emitting surface is parallel to the substrate.

(2) Second Light-Emitting Element Manufacturing Method FIGS. 4 to 17 are process diagrams sequentially showing a second light-emitting element manufacturing method used in the light-emitting device according to the first embodiment of the present invention.

  In the second embodiment, first, the prepared sapphire substrate 101 is cleaned as shown in FIG.

  Next, as shown in FIG. 5, an n-type GaN film 102 is formed on the sapphire substrate 101.

Next, as shown in FIG. 6, a mask layer 103 is formed on the n-type GaN film 102 by deposition. The mask layer 103 is made of, for example, SiN or SiO ₂ .

  Next, a resist layer 105 is applied onto the mask layer 103, exposed and developed (development), and further dry-etched to form holes 105A in the resist layer 105 and the mask layer 103 as shown in FIG. , 103A. A part 102A of the n-type GaN film 102 is exposed through the holes 105A and 103A. The mask layer 103 serves as a growth mask, and a hole 103A formed in the mask layer 103 serves as a growth hole.

  Next, in the catalyst metal formation step, as shown in FIG. 8, a catalyst metal 106 is deposited (deposited) on the resist layer 105 and a part 102A of the n-type GaN film 102 exposed in the hole 103A. As this catalytic metal 106, for example, Ni, Fe or the like can be adopted.

  Next, the resist layer 105 and the catalyst metal 106 on the resist layer 105 are removed by lift-off, leaving the catalyst metal 106 on a part 102A of the n-type GaN film 102 as shown in FIG. I do.

Next, in the semiconductor core formation step, as shown in FIG. 10, n-type GaN is crystal-grown using an MOCVD (Metal Organic Chemical Vapor Deposition) apparatus in the presence of the catalytic metal 106. A rod-shaped semiconductor core 107 having a substantially hexagonal cross section is formed. The rod-shaped semiconductor core 107 is grown to a length of 25 μm, for example. The growth temperature is set to about 800 ° C., trimethylgallium (TMG) and ammonia (NH ₃ ) are used as growth gases, silane (SiH ₄ ) is used for supplying n-type impurities, and hydrogen (H ₂ ) is used as a carrier gas. The n-type semiconductor core 107 with Si as an impurity can be grown. Here, the n-type GaN has hexagonal crystal growth, and a hexagonal column-shaped semiconductor core is obtained by growing the n-type GaN with the c-axis direction perpendicular to the surface of the sapphire substrate 101. Although depending on the growth conditions such as the growth direction and growth temperature, when the diameter of the semiconductor core to be grown is as small as several tens to several hundreds of nanometers, the cross section tends to be almost circular, and the diameter is 0.5 μm. When the thickness is increased from about a few μm, it tends to be easy to grow the cross section in a substantially hexagonal shape.

  A plurality of holes 105A in the resist layer 105 and a plurality of holes 103A in the mask layer 103 are formed, and a catalytic metal 106 is formed in a part 102A of the n-type GaN film 102 at a plurality of positions exposed in the plurality of holes 105A and 103A. Thus, a plurality of rod-shaped semiconductor cores 107 are formed.

Next, as shown in FIG. 11, a quantum well layer 108 made of p-type InGaN is formed by MOCVD so as to cover the semiconductor core 107 made of n-type GaN and the mask layer 103. The quantum well layer 108 has a set temperature of 750 ° C. according to the emission wavelength, supplies nitrogen (N ₂ ) as a carrier gas, TMG, NH ₃ , and trimethylindium (TMI) as a growth gas, so that an n-type GaN A quantum well layer 108 made of p-type InGaN can be formed on the semiconductor core 107 and the mask layer 103. In this quantum well layer, a p-type AlGaN layer may be inserted as an electron blocking layer between the InGaN layer and the p-type GaN layer. Alternatively, a multiple quantum well structure in which GaN barrier layers and InGaN quantum well layers are alternately stacked may be employed.

Next, in the semiconductor layer forming step, as shown in FIG. 11, a semiconductor layer 110 made of p-type GaN is formed on the entire surface of the quantum well layer 108 by MOCVD. The semiconductor layer 110 can be formed of p-type GaN by setting the set temperature to 900 ° C., using TMG and NH ₃ as growth gases, and using Cp ₂ Mg for supplying p-type impurities.

  In the growth of the quantum well layer 108 and the semiconductor layer 110 by the MOCVD, since the film is formed with the catalyst metal 106 attached, the catalyst metal 106 and the semiconductor core are compared with the growth rate of the portion covering the side surface 107B of the semiconductor core 107. The growth speed of the portion between the tip surface 107A of 107 is fast, for example, 10 to 100 times. As a specific example, the growth rate of GaN at the location where the catalyst metal 106 is adhered is 50 to 100 μm / hour, whereas the growth rate of GaN at the location where the catalyst metal is not adhered is 1 to 2 μm / hour. . Therefore, in the quantum well layer 108 and the semiconductor layer 110, the film thicknesses of the front end portions 108A and 110A are larger than the film thicknesses of the side surface portions 108B and 110B.

  Next, as shown in FIG. 12, in the catalytic metal removal step, the catalytic metal 106 on the semiconductor core 107 is removed by etching and then cleaning is performed, and the semiconductor layer 110 is activated by annealing. Here, the quantum well layer 108 covering the front end surface 107A of the semiconductor core 107 and the thickness of the front end portions 108A and 110A of the semiconductor layer 110 are the quantum well layer 108 covering the side surface 107B of the semiconductor core 107 and the side surface portion of the semiconductor layer 110. Since it is thicker than the thickness of 108B and 110B, damage and defects on the metal removal surface are less likely to adversely affect the PN junction. In addition, the semiconductor core 107 can be prevented from being exposed from the semiconductor layer 110 during etching.

  Next, as shown in FIG. 13, a conductive film 111 is formed on the entire surface of the semiconductor layer 110 made of p-type GaN. Polysilicon, ITO (tin-added indium oxide), or the like can be used as the material of the conductive film 111. The film thickness of the conductive film 111 is, for example, 200 nm. Then, after the conductive film 111 is formed, the contact resistance between the semiconductor layer 110 made of p-type GaN and the conductive film 111 can be reduced by performing heat treatment at 500 ° C. to 600 ° C. Note that the conductive film 111 is not limited to this, and for example, a 5 nm thick Ag / Ni or Au / Ni semi-transparent laminated metal film may be used. Vapor deposition or sputtering can be used to form this laminated metal film. Further, in order to further reduce the resistance of the conductive layer, a laminated metal film of Ag / Ni or Au / Ni may be laminated on the conductive film made of ITO.

  Next, as shown in FIG. 14, the conductive film 111 in a portion extending in the lateral direction on the semiconductor core 107 and the mask layer 103 is removed by RIE (reactive ion etching) of dry etching. Further, the tip portion 110A of the semiconductor layer 110 covering the tip surface 107A of the semiconductor core 107 is removed by a certain thickness by the RIE. Further, the semiconductor layer 110 in a region extending in the lateral direction beyond the conductive film 111 on the mask layer 103 is removed by the RIE. In addition, the quantum well layer 108 in the region extending laterally beyond the conductive film 111 on the mask layer 103 is removed by the RIE.

  As described above, before the RIE, the film thickness of the front end portion 108A of the quantum well layer 108 is sufficiently thicker than the film thickness of the side surface portion 108B, and the film thickness of the front end portion 110A of the semiconductor layer 110 is increased. Since it is sufficiently thicker than the film thickness of 110B, the semiconductor core 107 is not exposed at the tip after the RIE. Therefore, the quantum well layer 108 and the semiconductor layer 110 that cover the front end surface of the semiconductor core 107 and the quantum well layer 108, the semiconductor layer 110, and the conductive film 111 that cover the side surface of the semiconductor core 107 remain by the RIE.

Next, as shown in FIG. 15, the mask layer 103 (shown in FIG. 14) is removed by etching. When the mask layer 103 is made of silicon oxide (SiO ₂ ), the semiconductor core 107 and the semiconductor layer 110 covering the semiconductor core 107 and the conductive film 111 can be easily formed by using a solution containing hydrofluoric acid (HF). The mask layer 103 can be etched without affecting this portion. Further, by dry etching using CF ₄ , the mask layer 103 can be easily etched without affecting the semiconductor core 107, the semiconductor layer 110 covering the semiconductor core 107, and the conductive film 111. As a result, the semiconductor core 107 exposes the outer peripheral surface of the exposed portion 107C on the sapphire substrate 101 side.

  Next, as shown in FIG. 16, the underlying n-type GaN film 102 is etched by RIE (reactive ion etching) to expose the surface of the sapphire substrate 101. As a result, a step portion 102B made of n-type GaN connected to the semiconductor core 107 is formed. Here, since the thickness of the semiconductor layer 110 and the quantum well layer 108 on the front end face 107A is sufficiently larger than the thickness of the underlying n-type GaN film 102, the RIE makes it possible to The tip surface 107A can be prevented from being exposed.

  Thus, a rod-like structure including the semiconductor core 107 made of n-type GaN, the quantum well layer 108 made of p-type InGaN, the semiconductor layer 110 made of p-type GaN, the conductive film 111, and the step portion 102B made of n-type GaN. The light emitting element is formed on the sapphire substrate 101.

  Next, in the separation step, the substrate is immersed in an isopropyl alcohol (IPA) aqueous solution, and the base substrate (sapphire substrate 101) is vibrated along the plane of the substrate using ultrasonic waves (for example, several tens of kHz). As shown in FIG. 17, the quantum well layer 108, the semiconductor layer 110, and the semiconductor core 107 covered with the conductive film 111 are stressed so that the semiconductor core 107 standing upright is bent. The semiconductor core 110 covered with the semiconductor layer 110 and the conductive film 111 is separated from the base substrate.

  In this way, the fine rod-shaped structure light emitting element 100 separated from the base substrate can be manufactured.

  Further, the semiconductor core 107 is separated from the substrate using ultrasonic waves. However, the present invention is not limited thereto, and the semiconductor core 107 may be separated by mechanically bending the semiconductor core from the substrate using a cutting tool. In this case, a plurality of fine rod-shaped light emitting elements provided on the substrate can be separated in a short time by a simple method.

  Further, in the rod-shaped structure light emitting device 100, the semiconductor layer 110 grows crystal radially outward from the outer peripheral surface of the semiconductor core 107, the radial growth distance is short, and the defects escape outward. 110 can cover the semiconductor core 107. Therefore, it is possible to realize a rod-shaped structure light emitting device with good characteristics.

  According to this method for manufacturing a light emitting element, it is possible to manufacture the fine rod-shaped structure light emitting element 100 separated from the base substrate. Further, the sapphire substrate 101 can be reused. Further, the rod-shaped structure light emitting element 100 can reduce the amount of semiconductor to be used, can reduce the thickness and weight of the device using the light emitting element, and can also reduce the entire circumference of the semiconductor core 107 covered with the semiconductor layer 110. Since the light emitting region is widened by emitting light from the light emitting device, a light emitting device, a backlight, a lighting device, a display device, and the like with high luminous efficiency and power saving can be realized. Further, as shown in FIG. 16, the base n-type GaN film 102 is etched by RIE (reactive ion etching) to form the stepped portion 102B. However, the etching of the base n-type GaN film 102 is omitted. The semiconductor core 107 may be separated from the base n-type GaN film 102 without the portion 102B to produce a rod-shaped structure light emitting element that does not have the stepped portion 102B.

Here, since the rod-shaped structure light emitting device 100 has a diameter of 1 μm and a length of 25 μm, the light emission area of each rod-shaped structure light emitting device 100, that is, the area of the quantum well layer 108 is approximately (25 × π × (0 5) ² μm ² − (peripheral area of the exposed portion 107C)).

  Further, the rod-shaped structure light emitting device 100 has a cylindrical light emitting surface (quantum well layer 108) concentrically surrounding the rod-shaped semiconductor core 107, so that the light emitting device having a flat light emitting surface with the same volume can be obtained. The area of the light emitting surface per one of the rod-like structure light emitting elements 100 increases, the number of light emitting elements for obtaining a predetermined brightness can be reduced, and the cost can be reduced.

  Moreover, the rod-shaped structure light emitting element 100 has a p-type rod-shaped semiconductor core 107 and an n-type cylindrical semiconductor layer 110 covering the outer periphery of the semiconductor core 107, and one end side of the semiconductor core 107 is exposed. As a result, one electrode can be connected to the exposed portion 107C on one end side of the semiconductor core 107, and the electrode can be connected to the conductive film 111 on the other end side of the semiconductor core 107. In addition, since the electrode connected to the conductive film 111 and the exposed portion 107C of the semiconductor core 107 are prevented from being short-circuited, wiring can be facilitated.

  The cross sections of the exposed portion 107C of the semiconductor core 107 and the covering portion covered with the semiconductor layer 110 are not limited to hexagonal shapes, and may be other polygonal or circular cross sectional shapes. The exposed portion and the covering portion may have different cross-sectional shapes.

  In addition, according to the second light emitting element manufacturing method of the first embodiment, the p-type semiconductor layer 110 is formed not only on the front end surface 107A of the n-type semiconductor core 107 but also on the side surface 107B. , The light emission area can be increased, and the light emission efficiency can be improved. In addition, since the n-type semiconductor core 107 is formed using the catalyst metal 106, the growth rate of the n-type semiconductor core 107 can be increased. For this reason, the semiconductor core 107 can be lengthened in a short time compared to the conventional case, and the light emitting area that is proportional to the length of the n-type semiconductor core 107 can be further increased. In addition, since the tip surface 107A and the side surface of the n-type semiconductor core 107 are covered with the p-type semiconductor layer 110, an electrode for the p-type semiconductor layer 110 is prevented from being short-circuited to the n-type semiconductor core 107. it can.

  In addition, according to the second light emitting device manufacturing method of the first embodiment, the p-type quantum well layer 108 and the p-type semiconductor layer 110 are formed in a state where the catalytic metal 106 is left. The formation of the semiconductor core 107 and the formation of the p-type quantum well layer 108 and the p-type semiconductor layer 110 can be performed continuously in the same manufacturing apparatus. Therefore, process reduction and manufacturing time can be shortened. Further, since it is not necessary to take the semiconductor core 107 out of the manufacturing apparatus after forming the n-type semiconductor core 107, contamination can be prevented from adhering to the surface of the n-type semiconductor core 107, and the device characteristics can be improved. . In addition, since the formation of the n-type semiconductor core 107 and the formation of the p-type quantum well layer 108 and the p-type semiconductor layer 110 can be performed continuously, it is possible to avoid a large temperature change or stop of growth. Thus, crystallinity can be improved and device characteristics can be improved. Further, the etching of removing the catalytic metal 106 immediately after the formation of the n-type semiconductor core 7 is not performed, so that the surface of the n-type semiconductor core 107 (that is, the interface with the p-type semiconductor layer 110). Damage can be eliminated, and device characteristics can be improved.

  Further, in the second light emitting device manufacturing method of the first embodiment, the n-type semiconductor core 107 and the p-type semiconductor layer 110 are formed in this order while the catalyst metal 106 is attached to the sapphire substrate 101, so that the catalyst The growth rate of the portion in contact with the metal 106 is significantly higher (for example, 10 to 100 times) than the growth rate of the portion not in contact with the catalyst metal 106. Therefore, a light-emitting element with a high dimension aspect ratio can be manufactured. In the second embodiment, as an example, the rod-shaped structure light emitting element 100 has a diameter of 1 μm and a length of 25 μm. In addition, since the n-type semiconductor core 107 and the p-type semiconductor layer 110 can be successively stacked under the catalyst metal 106, defects at the PN junction can be reduced.

  Further, according to the second light emitting device manufacturing method of the first embodiment, the mask layer 103 is removed to expose the exposed portion 107C of the semiconductor core 107 on the sapphire substrate 101 side, so that the etching of the semiconductor layer 110 is performed. The amount can be reduced. Further, the rod-shaped structure light emitting element 100 can be easily contacted with the semiconductor core 107 by the step portion 102 </ b> B made of n-type GaN connected to the semiconductor core 107. Further, the rod-shaped structure light emitting device 100 can improve the light emission efficiency by the quantum well layer 108.

  In the second light emitting device manufacturing method, the n-type GaN film 102 is formed on the sapphire substrate 101. However, the step of forming the n-type GaN film 102 on the sapphire substrate 101 is eliminated, and the sapphire substrate is formed. A mask layer 103 may be formed directly on 101. In the catalyst metal removal step, the catalyst metal 106 on the semiconductor core 107 is removed by etching. However, the catalyst metal removal step may be omitted, and the conductive film 111 may be formed with the catalyst metal 106 remaining. In the above embodiment, as shown in FIG. 14, the conductive film 111, the semiconductor layer 110 made of p-type GaN, and the quantum well layer 108 are etched by RIE. However, this etching process by RIE is eliminated, and the next mask is formed. In the step of removing the layer 103, the mask layer 103 may be removed by simultaneous lift-off of each layer.

  In the second method for manufacturing a light emitting element, the semiconductor core 107 is crystal-grown using an MOCVD apparatus, but the semiconductor core is formed using another crystal growth apparatus such as an MBE (molecular beam epitaxial) apparatus. May be. Further, although the semiconductor core is crystal-grown on the substrate using the growth mask having the growth holes, the semiconductor core may be crystal-grown from the metal species by arranging a metal species on the substrate.

  In the second method for manufacturing a light emitting element, the semiconductor core 107 covered with the semiconductor layer 110 is separated from the sapphire substrate 101 using ultrasonic waves. However, the present invention is not limited thereto, and the semiconductor core 107 is cut using a cutting tool. May be mechanically bent and separated from the substrate. In this case, a plurality of fine rod-shaped light emitting elements provided on the substrate can be separated in a short time by a simple method.

(3) Light-Emitting Element Arrangement Step FIG. 18 is a plan view of an insulating substrate used in the method for manufacturing the light-emitting device of the first embodiment of the present invention. Note that the rod-shaped structure light-emitting element used in this light-emitting device uses either the rod-shaped structure light-emitting element 10 shown in FIG. 3 or the rod-shaped structure light-emitting element 100 shown in FIG. 17, but other rod-shaped light-emitting elements are used. Also good.

  In the light emitting device according to the first embodiment, as shown in FIG. 18, first, metal electrodes 201 and 202 as examples of the first and second electrodes and the wiring pattern are formed on the mounting surface in the substrate forming process. An insulating substrate 200 is created. The insulating substrate 200 is an insulator such as glass, ceramic, aluminum oxide, resin, or a substrate in which a silicon oxide film is formed on a semiconductor surface such as silicon, and the surface is insulative. When a glass substrate is used, it is desirable to form a base insulating film such as a silicon oxide film or a silicon nitride film on the surface.

  The metal electrodes 201 and 202 are formed in a desired electrode shape using a printing technique. The metal film and the photosensitive film may be uniformly laminated, and a desired electrode pattern may be exposed and etched.

  Although not shown in FIG. 18, pads are formed on the metal electrodes 201 and 202 so that a potential can be applied from the outside.

  Next, in the arranging step, the rod-shaped structure light emitting elements are arranged in a portion (array region) where the metal electrodes 201 and 202 are opposed to each other. In FIG. 18, in order to make the drawing easier to see, the array region in which the rod-shaped structure light emitting elements are arrayed is 9 × 3. However, in actuality, an arbitrary number of array regions of 100 or more is used.

  The substrate creating process, the applying process, and the arranging process constitute an arranging process for arranging a plurality of light emitting elements on the substrate.

  19 is a schematic sectional view taken along line XIX-XIX in FIG.

  First, in the coating process, as shown in FIG. 19, isopropyl alcohol (IPA) 211 including the rod-shaped structure light emitting element 210 is thinly coated on the insulating substrate 200. In addition to IPA 211, ethylene glycol, propylene glycol, methanol, ethanol, acetone, or a mixture thereof may be used. Alternatively, the IPA 211 can use a liquid made of another organic material, water, or the like.

  However, if a large current flows between the metal electrodes 201 and 202 through the liquid, a desired voltage difference cannot be applied between the metal electrodes 201 and 202. In such a case, an insulating film of about 10 nm to 30 nm may be coated on the entire surface of the insulating substrate 200 so as to cover the metal electrodes 201 and 202.

The thickness of the application of the IPA 211 including the rod-shaped structure light emitting element 210 is such that the rod-shaped structure light emitting element 210 can move in the liquid so that the rod-shaped structure light emitting element 210 can be arranged in the next step of arranging the rod-shaped structure light emitting element 210. That's it. Therefore, the thickness of applying the IPA 211 is equal to or greater than the thickness of the rod-shaped structure light emitting element 210, and is, for example, several μm to several mm. If the applied thickness is too thin, the rod-like structure light emitting element 210 is difficult to move. If it is too thick, the time for drying the liquid becomes long. Further, the amount of the rod-shaped structure light emitting element 210 is preferably 1 × 10 ⁴ pieces / cm ³ to 1 × 10 ⁷ pieces / cm ³ with respect to the amount of IPA.

  In order to apply the IPA 211 including the rod-shaped structure light emitting element 210, a frame is formed on the outer periphery of the metal electrode on which the rod-shaped structure light emitting element 210 is arranged, and the IPA 211 including the rod-shaped structure light emitting element 210 is formed in a desired thickness. It may be filled so that However, when the IPA 211 including the rod-shaped structure light emitting element 210 has viscosity, it can be applied to a desired thickness without the need for a frame.

  A liquid made of IPA, ethylene glycol, propylene glycol,..., Or a mixture thereof, or other organic substances, or a liquid such as water is desirable as the viscosity is low for the alignment process of the rod-shaped structure light emitting device 210. It is desirable that it evaporates easily when heated.

  Next, a potential difference is applied between the metal electrodes 201 and 202. In the first embodiment, a potential difference of 1V was appropriate. The potential difference between the metal electrodes 201 and 202 can be 0.1 to 10 V. However, if the voltage difference is 0.1 V or less, the arrangement of the rod-shaped structure light emitting elements 210 is poor, and if it is 10 V or more, insulation between the metal electrodes becomes a problem. start. Therefore, it is preferably 1 to 5V, and more preferably about 1V.

  FIG. 20 shows the principle that the rod-shaped structure light emitting element 210 is arranged on the metal electrodes 201 and 202. As shown in FIG. 20, when a potential VL is applied to the metal electrode 201 and a potential VR (VL <VR) is applied to the metal electrode 202, a negative charge is induced in the metal electrode 201 and a positive charge is applied to the metal electrode 202. Is induced. When the rod-shaped structure light emitting element 210 approaches there, a positive charge is induced on the side close to the metal electrode 201 and a negative charge is induced on the side close to the metal electrode 202 in the rod-shaped structure light emitting element 210. The charge is induced in the rod-like structure light emitting element 210 due to electrostatic induction. That is, the rod-shaped structure light emitting element 210 placed in the electric field is caused by the charge being induced on the surface until the internal electric field becomes zero. As a result, an attractive force is exerted between each electrode and the rod-shaped structure light emitting element 210 by an electrostatic force, and the rod-shaped structure light emitting element 210 follows the lines of electric force generated between the metal electrodes 201 and 202 and also has each rod-shaped structure light emitting element 210. Since the charges induced in the are substantially equal, the repulsive force caused by the charges causes the charges to be regularly arranged in a fixed direction at almost equal intervals. However, for example, in the rod-shaped structure light emitting device 100 shown in FIG. 17, the direction of the exposed portion side of the semiconductor core 107 covered with the semiconductor layer 110 is not constant and is random.

  As described above, the rod-like structure light emitting element 210 generates charges in the rod-like structure light emitting element 210 by the external electric field generated between the metal electrodes 201 and 202, and the rod-like structure light emitting element 210 is applied to the metal electrodes 201 and 202 by the attractive force of the charges. Therefore, the size of the rod-shaped structure light emitting element 210 needs to be a size that can move in the liquid. Therefore, the size of the rod-shaped structure light emitting element 210 varies depending on the application amount (thickness) of the liquid. When the liquid application amount is small, the rod-like structure light emitting element 210 must be nano-order size, but when the liquid application amount is large, it may be micro order size.

  When the rod-shaped structure light emitting device 210 is not electrically neutral and is charged positively or negatively, the rod-shaped structure light emitting device 210 is simply formed by applying a static potential difference (DC) between the metal electrodes 201 and 202. It cannot be arranged stably. For example, when the rod-shaped structure light emitting element 210 is positively charged as a net, the attractive force with the metal electrode 202 in which the positive charge is induced becomes relatively weak. Therefore, the arrangement of the rod-shaped structure light emitting elements 210 is untargeted.

  In such a case, it is preferable to apply an AC voltage between the metal electrodes 201 and 202 as shown in FIG. In FIG. 21, a reference potential is applied to the metal electrode 202, and an AC voltage having an amplitude VPPL / 2 is applied to the metal electrode 201. By doing so, even when the rod-like structure light emitting element 210 is charged, the arrangement can be kept as a target. In this case, the frequency of the AC voltage applied to the metal electrode 202 is preferably 10 Hz to 1 MHz, and more preferably 50 Hz to 1 kHz because the arrangement is most stable. Furthermore, the AC voltage applied between the metal electrodes 201 and 202 is not limited to a sine wave, but may be any voltage that varies periodically, such as a rectangular wave, a triangular wave, and a sawtooth wave. VPPL was preferably about 1V.

  Next, after arranging the rod-shaped structure light emitting elements 210 on the metal electrodes 201 and 202, the insulating substrate 200 is heated to evaporate and dry the liquid. They are arranged at equal intervals along the lines of electric force between 202 and fixed.

  FIG. 22 is a plan view of the insulating substrate 200 on which the rod-shaped structure light emitting element 210 is disposed. In FIG. 22, the number of bar-shaped light emitting elements 210 is reduced to make the drawing easier to see, but actually, 100 or more bar-shaped light emitting elements 210 are arranged on the same insulating substrate 200.

  By using the insulating substrate 200 on which the rod-shaped structure light emitting element 210 shown in FIG. 22 is disposed for a backlight of a liquid crystal display device or the like, it is possible to reduce the thickness and weight of the backlight and achieve a light emitting efficiency and a power saving backlight. can do. Further, by using the insulating substrate 200 on which the rod-shaped structure light emitting element 210 is disposed as a lighting device, it is possible to realize a lighting device that can be reduced in thickness and weight and has high luminous efficiency and power saving.

  The pn polarities of the rod-shaped structure light emitting elements 210 are not aligned on one side, but are randomly arranged. For this reason, at the time of driving, it is driven by an alternating voltage, and the bar-shaped structure light emitting elements 210 having different polarities emit light alternately.

  In addition, according to the method for manufacturing a light emitting device, an insulating substrate 200 having an array region having two metal electrodes 201 and 202 each having an independent potential applied thereto is formed, and the insulating substrate 200 is formed on the insulating substrate 200. A liquid containing a plurality of rod-shaped structure light emitting elements 210 is applied to the substrate. Thereafter, independent voltages are applied to the two metal electrodes 201 and 202, respectively, so that the fine rod-shaped light emitting elements 210 are arranged at positions defined by the two metal electrodes 201 and 202. Thereby, the rod-shaped structure light emitting element 210 can be easily arranged on the predetermined insulating substrate 200.

  Therefore, it is not necessary to arrange each light emitting diode at a predetermined position on the substrate as in the prior art, and a large number of fine light emitting diodes can be accurately disposed at a predetermined position.

  By this light emitting device manufacturing method, light emission is dispersed while suppressing temperature rise during light emission, so that a light emitting device with little variation in brightness and capable of extending life and efficiency can be manufactured.

  Moreover, in the manufacturing method of the light emitting device, the amount of semiconductor used can be reduced. Further, the light emitting element 210 has a light emitting area that is widened by emitting light from the entire side surface of the semiconductor core covered with the semiconductor layer, and thus a light emitting device with high luminous efficiency and low power consumption can be realized. it can.

  Further, in the above light emitting device, by arranging a plurality of light emitting elements substantially uniformly distributed on the mounting surface of the insulating substrate 200, the heat generated in the light emitting elements due to light emission can be efficiently discharged in the lateral direction. Therefore, the temperature rise at the time of light emission is further suppressed, and a longer life and higher efficiency can be achieved.

  Further, by arranging the rod-shaped structure light emitting elements 210 on the mounting surface of the insulating substrate 200 so that the longitudinal direction of the plurality of rod-shaped structure light emitting elements 210 is parallel to the mounting surface of the insulating substrate 200, the diameter Since the ratio of the length in the axial direction (longitudinal direction) to the direction can be increased, the heat flow in the lateral direction to the insulating substrate 200 is more efficient than when the light emitting surface is square under the same light emitting surface area. As a result, the temperature rise at the time of light emission is further suppressed, and a longer life and higher efficiency can be achieved. In addition, since this method of manufacturing a light-emitting device uses polarization of an object by applying a voltage between electrodes, it is convenient for polarizing both ends of a rod-shaped structure light-emitting element. And good compatibility.

  The rod-shaped structure light emitting element 210 is a light emitting diode having an anode connected to the metal electrode 201 (first electrode) and a cathode connected to the metal electrode 202 (second electrode). The light emitting diode having the cathode connected to the metal electrode 201 (first electrode) and the anode connected to the metal electrode 202 (second electrode) is mixed and disposed on the insulating substrate 200. Become. In this light emitting device, a plurality of light emitting diodes are driven by applying an AC voltage between the metal electrode 201 (first electrode) and the metal electrode 202 (second electrode) by an AC power source. Therefore, it is not necessary to arrange the anode and the cathode in the same direction with respect to the light emitting diode, and the arrangement process can be simplified.

  In addition, by using at least the metal electrode 201 (first electrode) and the metal electrode 202 (second electrode) as electrodes for driving the plurality of rod-shaped structure light emitting elements 210, the wiring process is simplified and the cost is reduced. Can be reduced.

  In the method for manufacturing the light emitting device shown in FIGS. 18 to 22, the rod-shaped structure light emitting element is used. However, the light emitting element is not limited to this, and flat light emission such as a circular shape, an elliptical shape, a square shape, a rectangular shape, or a polygonal shape is used. A light emitting element having a surface and arranged on the mounting surface so that the light emitting surface thereof is parallel to the substrate may be used. However, since this method for manufacturing a light emitting device uses polarization of an object by applying a voltage between electrodes, a rod-shaped light emitting element that is convenient for polarization is desirable.

(4) Wiring Process FIGS. 23 to 25 show process diagrams of another method for manufacturing a light emitting device according to the first embodiment of the present invention. In this light emitting device manufacturing method, 100 or more rod-shaped structured light emitting elements are arranged on the mounting surface of the same substrate. A rod-shaped structured light-emitting element used in this method for manufacturing a light-emitting device has a first-conductivity-type rod-shaped semiconductor core and a second-conductivity-type cylindrical semiconductor layer covering the outer periphery of the semiconductor core, and emits a rod-shaped light-emitting element. Any element may be used as long as one end side of the semiconductor core of the element is exposed.

  In this method for manufacturing a light emitting device, as shown in FIG. 23, first, in a substrate forming process, first and second electrodes and metal electrodes 301 and 302 as an example of a wiring pattern are formed on a mounting surface. 300 is created.

  Next, in the arranging step, 100 or more rod-shaped structure light emitting elements 310 are arranged on the insulating substrate 300 so that the longitudinal direction is parallel to the mounting surface of the insulating substrate 300. In this arrangement step, the rod-shaped structure light emitting elements 310 in the liquid are arranged on the metal electrodes 301 and 302 using the same method as the method for manufacturing the light emitting device of the first embodiment, and then the insulating substrate 300 is formed. By heating, the liquid is evaporated and dried, and the rod-shaped structure light emitting elements 310 are arranged at equal intervals along the lines of electric force between the metal electrodes 301 and 302 and fixed.

  The bar-shaped structured light emitting element 310 includes a semiconductor core 311 made of a rod-shaped n-type GaN and an exposed portion 311a other than the exposed portion 311a of the semiconductor core 311 so as not to cover a portion on one end side of the semiconductor core 311. And a semiconductor layer 312 made of p-type GaN covering the covering portion 311b. The exposed portion 311 a on one end side of the rod-shaped structure light emitting element 310 is connected to the metal electrode 301, and the semiconductor layer 312 on the other end side of the rod-shaped structure light emitting element 310 is connected to the metal electrode 302.

  Next, in the wiring process, as shown in FIG. 24, an interlayer insulating film 303 is formed on the insulating substrate 300, and the interlayer insulating film 303 is patterned to contact holes on the metal electrode 301 and the metal electrode 302. 303a is formed.

  Next, as shown in FIG. 25, metal wirings 304 and 305 are formed so as to fill the two contact holes 303a.

  In this manner, 100 or more rod-shaped structure light emitting elements 310 arranged on the mounting surface of the insulating substrate 300 are collectively disposed, and the metal wirings 304 and 305 are collectively disposed on the plurality of rod-shaped structure light emitting elements 310. Can be connected. 23 to 25, the central portion of the rod-shaped structure light emitting element 310 is shown in a state of floating from the insulating substrate 300, but actually, the rod-shaped structure light emitting element 310 has the rod shape shown in FIGS. 18 to 22. When drying the IPA aqueous solution in the method of arranging the structured light emitting elements, the central portion is bent due to stiction generated when droplets in the gap between the surface of the insulating substrate 300 and the rod-shaped structured light emitting element 310 are reduced by evaporation, and the insulating substrate 300 It touches the top. Even when the rod-shaped light emitting element 310 is not in direct contact with the insulating substrate 300, the rod-shaped light emitting element 310 is in contact with the insulating substrate 300 through the interlayer insulating film 303.

  Further, a metal part is provided between the central part of the rod-shaped structure light emitting element 310 and the insulating substrate 300 so as to support the rod-shaped structure light emitting element 310, and the central part of the rod-shaped structure light emitting element 310 is interposed via the metal part. It may be in contact with the insulating substrate 300.

  According to the above method for manufacturing a light emitting device, it is not necessary to dispose light emitting diodes at predetermined positions on a substrate as in the prior art, and a large number of fine light emitting diodes are accurately disposed at predetermined positions. In addition, by dispersing light emission while suppressing a temperature rise during light emission, a light-emitting device that has little variation in brightness and can have a long lifetime and high efficiency can be manufactured.

  In the light-emitting device, the plurality of rod-shaped structure light-emitting elements 310 are arranged on the mounting surface of the insulating substrate 300 so as to be substantially evenly distributed, so that the heat generated in the light-emitting elements due to light emission flows laterally to the substrate side. Therefore, the temperature rise at the time of light emission is further suppressed, and a longer life and higher efficiency can be achieved.

  Further, by arranging the rod-shaped structure light emitting elements 310 on the mounting surface of the insulating substrate 300 so that the longitudinal direction of the plurality of rod-shaped structure light emitting elements 310 is parallel to the mounting surface of the insulating substrate 300, the diameter Since the ratio of the length in the axial direction (longitudinal direction) with respect to the direction can be increased, heat flow in the lateral direction toward the insulating substrate 300 is more efficient than when the light emitting surface is square under the same light emitting surface area. It is often performed, and the temperature rise at the time of light emission is further suppressed, and a longer life and higher efficiency can be achieved.

  The plurality of rod-shaped structure light emitting elements 310 are light emitting diodes having an exposed portion 311a as an anode and a covering portion 311b as a cathode. The anode is connected to the metal electrode 301 (first electrode) and the metal electrode 302 ( A light emitting diode having a cathode connected to the second electrode) and a light emitting diode having a cathode connected to the metal electrode 301 (first electrode) and an anode connected to the metal electrode 302 (second electrode). They are mixed and arranged on the insulating substrate 300. In this light emitting device, a plurality of light emitting diodes are driven by applying an AC voltage between the metal electrode 301 (first electrode) and the metal electrode 302 (second electrode) by an AC power source. Therefore, it is not necessary to arrange the anode and the cathode in the same direction with respect to the light emitting diode, and the arrangement process can be simplified.

(5) Other Light-Emitting Device Manufacturing Method FIGS. 26 to 30 show process diagrams of another light-emitting device manufacturing method according to the first embodiment of the present invention. 26 to 30 show only a part of the light-emitting device, and in the method for manufacturing the light-emitting device, 100 or more rod-shaped structure light-emitting elements are arranged on the mounting surface of the same substrate. A rod-shaped structured light-emitting element used in this method for manufacturing a light-emitting device has a first-conductivity-type rod-shaped semiconductor core and a second-conductivity-type cylindrical semiconductor layer covering the outer periphery of the semiconductor core, and emits a rod-shaped light-emitting element. Any element may be used as long as one end side of the semiconductor core of the element is exposed.

  In this method of manufacturing a light emitting device, as shown in the cross-sectional view of FIG. 26 and the plan view of FIG. 27, first, in the substrate creation process, the first and second electrodes and the metal electrode as an example of the wiring pattern on the mounting surface An insulating substrate 400 on which 401 and 402 are formed is formed.

  Next, in the arranging step, the plurality of rod-shaped structure light emitting elements 410 are arranged on the insulating substrate 400 so that the longitudinal direction is parallel to the mounting surface of the insulating substrate 400. In this arrangement step, the rod-shaped structure light emitting elements 410 in the liquid are arranged on the metal electrodes 401 and 402 using the same method as the method for manufacturing the light emitting device shown in FIGS. By heating 400, the liquid is evaporated and dried, and the rod-shaped structure light emitting elements 410 are arranged at equal intervals along the lines of electric force between the metal electrodes 401 and 402.

  The bar-shaped structured light emitting element 410 includes a semiconductor core 411 made of a rod-shaped n-type GaN and an exposed portion 411a other than the exposed portion 411a of the semiconductor core 411 so as not to cover a portion on one end side of the semiconductor core 411. And a semiconductor layer 412 made of p-type GaN covering the covering portion 411b. The exposed portion 411a on one end side of the rod-shaped structure light emitting element 410 is connected to the metal electrode 401 by an adhesive portion 403 made of metal ink such as a conductive adhesive, and the semiconductor layer 412 on the other end side of the rod-shaped structure light emitting element 410 is connected. The metal electrode 402 is connected by an adhesive portion 404 made of metal ink such as a conductive adhesive. Here, the metal ink is applied to a predetermined location on the insulating substrate 400 by an inkjet method or the like.

  Next, as shown in the plan view of FIG. 28 and the cross-sectional view of FIG. 29, the phosphor 420 is selectively applied to a region on the insulating substrate 400 where the plurality of rod-shaped structure light emitting elements 410 are arranged (phosphor phosphor). Application process). Here, the phosphor is applied to a predetermined region on the insulating substrate 400 by an inkjet method or the like. Note that a transparent resin containing a phosphor may be selectively applied to a region on the insulating substrate 400 where the plurality of rod-shaped structured light emitting elements 410 are arranged.

  Next, as shown in FIG. 30, after the phosphor 420 is applied, a protective film 421 made of a transparent resin is formed on the insulating substrate 400.

  In this manner, the plurality of rod-shaped structure light emitting elements 410 can be collectively disposed on the mounting surface of the insulating substrate 400, and metal wirings can be collectively connected to the plurality of rod-shaped structure light emitting elements 410.

  Next, a phosphor coating process for coating the phosphor 420 on the insulating substrate 400, and a protective film coating process for coating the protective film 421 on the insulating substrate 400 after the phosphor coating process are performed in a plurality of rod shapes. This is performed at one time with one insulating substrate 400 on which the structured light emitting element 410 is arranged. As a result, the manufacturing cost can be greatly reduced as compared with the case where the conventional process is performed for each package.

(6) Substrate Dividing Step Next, the substrate dividing step of the method for manufacturing the light emitting device according to the first embodiment of the present invention will be described with reference to FIG. In this substrate dividing step, the insulating substrate 400 created by the steps shown in FIGS. 26 to 30 is used. However, the insulating substrate 200 created by the steps shown in FIGS. 18 to 22 and FIGS. 23 to 25 are used. The insulating substrate 300 formed by the process shown in FIG.

  As shown in the plan view of FIG. 31, in the substrate dividing step, the insulating substrate 400 is divided into a plurality of divided substrates 430A, 430B, 430C, 430D, and 430E having different shapes. Here, each of the plurality of divided substrates 430A, 430B, 430C, 430D, and 430E is the light emitting device of the present invention, and is divided from the insulating substrate 400 so as to have 100 or more rod-shaped structure light emitting elements 410. . The divided substrate 430A has a square shape, the divided substrate 430B has a larger square shape than the divided substrate 430A, the divided substrate 430C has a larger square shape than the divided substrate 430B, the divided substrate 430D has a circular shape, and the divided substrate 430E has a right triangle shape. ing.

  In the substrate dividing step, by dividing the insulating substrate 400 into a plurality of divided substrates 430A, 430B, 430C, 430D, and 430E having different shapes, light emitting devices corresponding to various forms can be easily provided.

  In addition, by not forming a wiring pattern formed for wiring the plurality of rod-shaped structure light emitting elements 410 on the insulating substrate 400 in the substrate cutting region in the substrate dividing step, conductive wiring debris is scattered at the time of cutting. Therefore, it is possible to prevent problems such as a short circuit due to conductive wiring debris.

  Alternatively, by forming a wiring pattern in the cutting region of the insulating substrate 400 that does not affect the electrical connection even if it is cut in the substrate dividing step, the wiring pattern can be continuously formed across adjacent divided substrates. In addition to being easy to form, there is no problem in circuit operation even if the substrate is cut during substrate division.

  Further, by not disposing the rod-like structure light emitting element 410 in the cutting region of the insulating substrate 400 in the substrate dividing step, the rod-like structure light emitting element 410 that is damaged by cutting can be eliminated, and the rod-like structure light emitting element 410 can be effectively used.

  In this method for manufacturing a light emitting device, FIGS. 26, 29, and 30 show the central portion of the rod-shaped structure light-emitting element 410 floating from the insulating substrate 400. In the method for arranging the bar-shaped structure light emitting elements according to the first embodiment, when the IPA aqueous solution is dried, the central portion is caused by stiction generated when the droplets in the gap between the surface of the insulating substrate 400 and the bar-shaped structure light emitting element 410 are reduced by evaporation. Is bent and is in contact with the insulating substrate 400. Even when the rod-like light emitting element 410 is not in direct contact with the insulating substrate 400, the rod-shaped light emitting element 410 is in contact with the insulating substrate 400 through the phosphor.

  A metal portion is provided between the central portion of the rod-shaped structure light emitting element 410 and the insulating substrate 400 so as to support the rod-shaped structure light emitting element 410, and the central portion of the rod-shaped structure light emitting element 410 is interposed via the metal portion. It may be in contact with the insulating substrate 400.

  According to the method for manufacturing a light emitting device having the above configuration, after the plurality of rod-shaped structure light emitting elements 410 arranged on the same insulating substrate 400 are wired together, the insulating substrate 400 is then divided into the plurality of divided substrates 430A and 430B. , 430C, 430D, 430E and forming a plurality of light emitting devices in which a plurality of rod-shaped light emitting elements 410 are arranged on the divided substrates 430A, 430B, 430C, 430D, 430E, thereby simplifying the wiring process. Manufacturing cost can be reduced, characteristic variation can be reduced, and yield can be improved.

  Further, in the arrangement step, the plurality of rod-shaped structure light emitting elements 410 are collectively arranged on the same insulating substrate 400, so that the manufacturing cost can be further reduced in combination with the simplification of the wiring step.

  In addition, by arranging 100 or more rod-shaped structure light emitting elements 410 on each of the divided substrates 430A, 430B, 430C, 430D, and 430E, variation in overall brightness when a plurality of light emitting elements having brightness variations are assembled. Can be reduced to 1/10 or less of the brightness variation of one light emitting element.

  The rod-shaped structure light emitting element 410 is a light emitting diode in which the exposed portion 411a is an anode and the covering portion 411b is a cathode, and the anode is connected to the metal electrode 401 (first electrode) and the metal electrode 402 (second electrode). And a light-emitting diode having a cathode connected to the metal electrode 401 (first electrode) and an anode connected to the metal electrode 402 (second electrode). Thus, it is disposed on the insulating substrate 400. In this light emitting device, a plurality of light emitting diodes are driven by applying an AC voltage between the metal electrode 401 (first electrode) and the metal electrode 402 (second electrode) by an AC power source. Therefore, it is not necessary to arrange the anode and the cathode in the same direction with respect to the light emitting diode, and the arrangement process can be simplified.

  Further, in the method for manufacturing the light emitting device, after the arranging step of arranging the plurality of rod-shaped structure light emitting elements 410 on the insulating substrate 400, the insulating substrate 400 is divided into 100 or more rod-shaped structure light emitting elements 410 in the substrate dividing step. Is divided into a plurality of divided substrates 430 arranged respectively, the number of substrates flowing in each process can be reduced and the cost can be greatly reduced.

  In addition, according to the method for manufacturing the light emitting device, it is not necessary to place each light emitting element at a predetermined position on the substrate as in the prior art, and a large number of fine light emitting elements are accurately disposed at a predetermined position. By dispersing light emission while suppressing temperature rise during light emission, a light-emitting device that has little variation in brightness and can have a long lifetime and high efficiency can be manufactured.

  In the light emitting device, a plurality of rod-shaped structure light emitting elements 410 are arranged substantially evenly distributed on the mounting surface of the insulating substrate 400, whereby the heat generated in the rod-shaped structure light emitting elements 410 due to light emission to the substrate side. Since the outflow in the direction is efficiently performed, the temperature rise at the time of light emission is further suppressed, and a longer life and higher efficiency can be achieved.

  Further, after arranging the plurality of rod-shaped structure light emitting elements 410 on the insulating substrate 400, the phosphor 420 is selectively applied to the region where the plurality of rod-shaped structure light emitting elements 410 are arranged on the insulating substrate 400. The cost can be reduced by reducing the amount of phosphor used, which accounts for a large proportion of material costs.

[Second Embodiment]
FIG. 32 shows a plan view of a light emitting device used in the illumination device of the second embodiment of the present invention, and FIG. 33 shows a side view of the light emitting device.

  As shown in FIGS. 32 and 33, the light-emitting device 500 used in the illumination device of the second embodiment has 100 or more rod-shaped structure light-emitting elements (not shown) arranged on a square heat sink 501. A circular insulating substrate 502 is mounted. Here, the circular insulating substrate 502 is a divided substrate on which 100 or more rod-shaped structure light emitting elements manufactured using the manufacturing method of the light emitting device of the first embodiment are arranged.

  FIG. 34 shows a side view of an LED bulb 510 as an example of a lighting device using the light emitting device 500 shown in FIGS. As shown in FIG. 34, the LED bulb 510 has a base 511 as a power supply connection part that is fitted in an external socket and connected to a commercial power source, and one end connected to the base 511, and the other end gradually expands. A conical heat radiation part 512 having a diameter and a light transmission part 513 covering the other end of the heat radiation part 512 are provided. In the heat radiating part 512, the light emitting device 500 is arranged with the insulating substrate 502 facing the light transmitting part 513 side. The light emitting device 500 is manufactured by the light emitting device manufacturing method of the first embodiment.

  According to the lighting device having the above structure, by using the light emitting device 500, manufacturing cost can be reduced, characteristic variation can be reduced, and yield can be improved.

  In addition, by using the light-emitting device 500 illustrated in FIGS. 32 and 33, a lighting device with little variation in brightness, which can have a long lifetime and high efficiency can be realized.

  In addition, the heat dissipation effect is further improved by attaching the insulating substrate 502 on which the plurality of rod-shaped structure light emitting elements are disposed on the heat dissipation plate 501.

[Third Embodiment]
FIG. 35 is a plan view of a backlight using the light emitting device according to the third embodiment of the present invention.

  In the backlight 600 according to the third embodiment, as shown in FIG. 35, a plurality of light emitting devices 602 are mounted in a grid pattern at predetermined intervals on a rectangular support substrate 601 as an example of a heat sink. Has been. Here, the light emitting device 602 is a divided substrate on which 100 or more rod-shaped structure light emitting elements manufactured using the method for manufacturing a light emitting device of the first embodiment are arranged.

  According to the backlight 600 having the above structure, the use of the light emitting device 602 can reduce the manufacturing cost, reduce the characteristic variation, and improve the yield.

  In addition, by using the light-emitting device 602, it is possible to realize a backlight that has little variation in brightness and can have a long lifetime and high efficiency.

  Further, by attaching the light emitting device 602 on the support substrate 601, the heat dissipation effect is further improved.

[Fourth Embodiment]
FIG. 36 is a plan view of a backlight using the light emitting device according to the fourth embodiment of the present invention.

  In the backlight 610 of the fourth embodiment, as shown in FIG. 36, one large light emitting device 612 is mounted on a rectangular support substrate 611 as an example of a heat sink. The light emitting device 612 is manufactured by the light emitting device manufacturing method of the first embodiment.

  According to the backlight 610 having the above structure, by using the light emitting device 612, manufacturing cost can be reduced, characteristic variation can be reduced, and yield can be improved.

  Further, by attaching the light emitting device 612 on the support substrate 611, the heat dissipation effect is further improved.

[Fifth Embodiment]
FIG. 37 shows a plan view and a side view of a liquid crystal panel using the light emitting device of the fifth embodiment of the present invention.

  As shown in FIG. 37, the liquid crystal panel 620 according to the fifth embodiment is formed on one surface of a rectangular transparent substrate 622 as an example of a heat sink, as an example of first and second electrodes and a wiring pattern. A metal electrode (not shown) is formed, and a plurality of light emitting elements (not shown) connected to the metal electrode are arranged. The light emitting portion 621 composed of the metal electrode and the light emitting element and the transparent substrate 622 form one large light emitting device. Further, pixel electrodes and TFTs (Thin Film Transistors) (not shown) are formed in a matrix on the other surface of the transparent substrate 622. A liquid crystal sealing plate 624 is disposed on the other side of the transparent substrate 622 with a predetermined interval, and the liquid crystal 623 is sealed between the liquid crystal sealing plate 624 and the transparent substrate 622.

  In a normal LCD panel, the LCD drive substrate and the backlight are separated, and due to problems such as uneven light intensity and heat generation of the backlight, the use of a light guide tube and heat dissipation element increases the cost, and the LCD panel It was getting thicker. On the other hand, according to the liquid crystal panel 620 having the above-described configuration, since it is composed of a plurality of light emitting elements with respect to the amount of light obtained from one conventional light emitting element, there is no problem of unevenness in light amount or heat generation. No light tube or heat dissipation element is required. Therefore, a light-emitting device, which is a divided substrate divided into large liquid crystal panels, is arranged on the side opposite to the surface having liquid crystal and used directly as a liquid crystal substrate, whereby a low-cost and thin liquid crystal panel can be obtained.

  As described above, according to the liquid crystal panel 620 having the above structure, by using the light emitting device including the light emitting portion 621 and the transparent substrate 622, the manufacturing cost can be reduced, the characteristic variation can be reduced, and the yield can be improved. In addition, by using the transparent substrate 622 in which the liquid crystal panel substrate and the backlight substrate are combined, the component cost and the manufacturing cost can be reduced, and a thinner liquid crystal panel can be realized.

  A transparent substrate, a plurality of light emitting elements arranged on one surface of the transparent substrate and connected to wiring formed on one surface of the transparent substrate, and a color formed on the other surface of the transparent substrate The present invention may be applied to a liquid crystal panel provided with a filter.

  For example, a liquid crystal panel 820 having such a configuration example is shown in FIG. As shown in the side view of FIG. 44, a metal electrode (not shown) as an example of the first and second electrodes and the wiring pattern is formed on one surface of a rectangular transparent substrate 822 as an example of a heat sink. A plurality of light emitting elements (not shown) formed and connected to the metal electrodes are arranged. The light emitting portion 821 including the metal electrode and the light emitting element and the transparent substrate 822 form one large light emitting device. A color filter 823 is formed on the other surface of the transparent substrate 822, and a protective film 824 is formed on the color filter 823. A glass substrate 827 is disposed on the other side of the transparent substrate 822 with a predetermined interval, and the liquid crystal 825 is sealed between the glass substrate 827 and the transparent substrate 822. Pixel electrodes and TFTs 826 (not shown) are formed in a matrix on the surface of the glass substrate 827 facing the liquid crystal 825.

  In this liquid crystal panel, by using a transparent substrate in which a color filter and a backlight substrate are combined, the component cost and the manufacturing cost can be reduced, and a thinner liquid crystal panel can be realized.

  In the first to fifth embodiments, the light emitting device using the light emitting diode as a light emitting element, the method for manufacturing the light emitting device, the illumination device, the backlight, and the liquid crystal panel have been described. However, the light emitting element of the present invention is not limited to the light emitting diode. The present invention is applied to a light emitting device using a light emitting element such as a semiconductor laser, an organic EL (Electro Luminescence), an inorganic EL (intrinsic EL), a method for manufacturing the light emitting device, a lighting device, a backlight, and a liquid crystal panel. You may apply.

  In the first and second light emitting device manufacturing methods of the first embodiment, the semiconductor core and the semiconductor layer are made of a semiconductor having GaN as a base material. However, GaAs, AlGaAs, GaAsP, InGaN, AlGaN, The present invention may be applied to a light emitting element using a semiconductor whose base material is GaP, ZnSe, AlGaInP or the like. Further, although the semiconductor core is n-type and the semiconductor layer is p-type, the present invention may be applied to a rod-shaped structure light-emitting element having a reverse conductivity type.

  In the second light emitting device manufacturing method of the first embodiment, the rod-shaped structure light emitting device having a hexagonal rod-shaped semiconductor core has been described. However, the present invention is not limited to this, and the rod-shaped cross section is circular or elliptical. The present invention may be applied to a rod-shaped structure light emitting device having a rod-shaped semiconductor core having another polygonal cross section.

  Moreover, in the manufacturing method of the 2nd light emitting element of the said 1st Embodiment, although the diameter of the rod-shaped structure light emitting element was 1 micrometer and length was made into the micro order size of 10 micrometers-30 micrometers, at least a diameter among diameter or length May be a nano-order sized element of less than 1 μm. The diameter of the semiconductor core of the rod-shaped structure light emitting element is preferably 500 nm or more and 100 μm or less, and variation in the diameter of the semiconductor core can be suppressed as compared with the rod-shaped structure light emitting element of several tens nm to several hundred nm, and the light emission area, that is, the light emission characteristics. Variation can be reduced and yield can be improved.

Note that if the lower limit of the light emitting area of the rod-shaped structure light emitting element is defined, it is 3.14 × 10 ⁻³ μm ² (the light emitting surface is formed in a cylindrical shape on the outer periphery of a rod-shaped semiconductor core having a diameter of 1 nm and a length of 1 μm). Area). Alternatively, if the light emitting element is a square plate, one side is 56 nm. It is difficult to form light emitting elements of any shape with a size smaller than this. Further, if the upper limit of the number of light emitting elements to be arranged on the mounting surface of the same substrate is defined, it is 100 million, and it is difficult to arrange with the yield higher than this.

  In the second light emitting device manufacturing method according to the first embodiment, the semiconductor core and the cap layer are crystal-grown using the MOCVD apparatus, but other crystal growth apparatuses such as an MBE (molecular beam epitaxial) apparatus are used. A semiconductor core or a cap layer may be formed using

  Further, in the method of manufacturing the light emitting device according to the first embodiment, the rod-shaped light emitting elements are arranged on the substrate and connected between the electrodes by utilizing the polarization of the rod-shaped light emitting elements by applying a voltage between the electrodes. However, the arrangement method for arranging a plurality of light emitting elements on the same substrate and the wiring method for wiring a part or all of the plurality of light emitting elements arranged on the substrate are not limited to this, but other methods May be used.

  For example, FIG. 38 shows a side view and an end view of a rod-like structure light emitting element used in a method for manufacturing a light emitting device according to another embodiment of the present invention, and FIGS. 39 to 43 show each step in the method for manufacturing the light emitting device. Show. 39 to 43 show only a part of the light-emitting device, and the method for manufacturing the light-emitting device is to arrange 100 or more rod-shaped structure light-emitting elements on the mounting surface of the same substrate.

  As shown in FIG. 38, this rod-shaped structure light emitting element 710 includes a rod-shaped semiconductor core 701 made of n-type GaN and having a substantially circular cross section, and a semiconductor layer 702 made of cylindrical p-type GaN covering the outer periphery of the semiconductor core 701. And have. The semiconductor core 701 is exposed only at the end surfaces on both sides. At this time, a quantum well layer may be provided between the semiconductor core 701 and the semiconductor layer 702.

  First, a solution containing such a rod-shaped structure light emitting element 710 is applied on an insulating substrate 720 as shown in FIG.

  Next, as shown in FIG. 40, by using a rubbing apparatus 721, a rubbing process is performed in which a solution (mainly a rod-shaped structure light emitting element 710) applied on the insulating substrate 720 is rubbed against the substrate side, thereby A plurality of rod-shaped structured light emitting elements 710 are arranged so that the longitudinal direction of the structured light emitting elements 710 is oriented in the same direction.

  Next, as shown in FIG. 41, the rubbed insulating substrate 720 is dried.

  Next, as shown in FIG. 42, the straight region S perpendicular to the longitudinal direction of the rod-shaped structure light emitting element 710 of the insulating substrate 720 on which the plurality of rod-shaped structure light emitting elements 710 are arranged is etched. A part of the semiconductor core 701 of the rod-shaped structure light emitting element 710 where the two overlap is exposed. Accordingly, some of the rod-shaped structure light emitting elements 710 have an exposed portion 710a where the n-type semiconductor core 701 is exposed and a covered portion 710b covered with the p-type semiconductor layer 702.

  Then, as shown in FIG. 43, the metal wiring 731 is formed in the straight region S of the insulating substrate 720, and the metal wiring 732 is formed substantially parallel to the metal wiring 731 at a predetermined interval.

  Accordingly, the metal wiring 731 is connected to a part of the n-type semiconductor cores 701 among the plurality of bar-shaped structure light emitting elements 710, and the metal wiring 732 is connected to a part of the plurality of bar-shaped structure light emitting elements 710. It is connected to a semiconductor layer 702 made of type GaN. For example, in FIG. 43, the metal wiring 731 is connected to the n-type semiconductor core 701 of the four rod-shaped structure light emitting elements 710A to 710D, and the gold metal wiring 732 is connected to the p-type semiconductor layer 702. Accordingly, by applying a voltage between the metal wiring 731 and the metal wiring 732 so that a current flows from the p-type semiconductor layer 702 side to the n-type semiconductor core 701 side, the four rod-shaped structure light emitting elements 710A˜ 710D emits light.

  Then, in the substrate dividing step, the insulating substrate 720 is divided into a plurality of divided substrates, thereby forming a plurality of light emitting devices in which a plurality of rod-shaped structure light emitting elements 710 are arranged on the divided substrates.

  In this way, among the plurality of light emitting elements, the rod-shaped structure light-emitting element 710 that does not affect the desired light emission amount even if it is cut in the substrate dividing step is disposed in the cutting region of the insulating substrate 720 and is broken by the cutting. Even if the light emitting element 710 does not emit light, light is emitted by the other plurality of bar-shaped light emitting elements 710 that are not cut, so that the bar-shaped light emitting elements 710 are not arranged in the cut region of the insulating substrate 720 in the arranging step. There is no need to consider, and the arrangement process can be simplified. Here, the “desired light emission amount” is one of the specifications required for the light emitting device.

  Although specific embodiments of the present invention have been described, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 ... n-type GaN layer 2 ... Quantum well layer 3 ... p-type GaN layer 20 ... n-type GaN substrate 10 ... Rod-shaped structure light emitting element 100 ... Rod-shaped structure light-emitting element 101 ... Sapphire substrate 102 ... N-type GaN film 103 ... Mask layer 105 DESCRIPTION OF SYMBOLS ... Resist layer 106 ... Catalytic metal 107 ... Semiconductor core 108 ... Quantum well layer 110 ... Semiconductor layer 111 ... Conductive film 200 ... Insulating substrate 201,202 ... Metal electrode 210 ... Rod-shaped structure light emitting element 211 ... IPA
DESCRIPTION OF SYMBOLS 300 ... Insulating substrate 310 ... Bar-shaped structure light emitting element 301,302 ... Metal electrode 303 ... Interlayer insulating film 304,305 ... Metal wiring 311 ... Semiconductor core 311a ... Exposed part 311b ... Covering part 312 ... Semiconductor layer 400 ... Insulating substrate 410 ... Bar-shaped structure light emitting element 401, 402... Metal electrode 403, 404... Adhesive portion 411... Semiconductor core 411a... Exposed portion 411b ... Cover portion 412 ... Semiconductor layer 420 ... Phosphor 421 ... Protective film 430 ... Light emitting device 500. DESCRIPTION OF SYMBOLS ... LED bulb 511 ... Base 512 ... Radiating part 513 ... Translucent part 600 ... Backlight 601 ... Support substrate 602 ... Light emitting device 610 ... Back light 611 ... Support substrate 612 ... Light emitting device 620 ... Liquid crystal panel 621 ... Light emitting part 622 ... Transparent Substrate 623 ... Liquid crystal 624 ... Liquid crystal sealing plate 701 ... Semiconductor A 702 ... Semiconductor layer 710 ... Bar-shaped structure light emitting element 720 ... Insulating substrate 721 ... Rubbing device 731, 732 ... Metal wiring 820 ... Liquid crystal panel 821 ... Light emitting part 822 ... Transparent substrate 823 ... Color filter 824 ... Protective film 825 ... Liquid crystal 826 ... TFT
827 ... Glass substrate

Claims (13)

An arrangement step of arranging a plurality of light emitting elements on the same substrate;
A wiring step of wiring a part or all of the plurality of light emitting elements arranged on the substrate in a lump;
A substrate dividing step of forming a plurality of light emitting devices in which a plurality of light emitting elements are arranged on the divided substrate by dividing the substrate into a plurality of divided substrates after the arranging step and the wiring step ;
The plurality of light emitting elements are rod-shaped,
The plurality of light emitting elements are arranged on the mounting surface of the substrate so that the longitudinal direction of the plurality of light emitting elements is parallel to the mounting surface of the substrate,
The rod-shaped light emitting element includes a first-conductivity-type rod-shaped semiconductor core, a second-conductivity-type tubular semiconductor layer covering the outer periphery of the semiconductor core, and a tubular shape concentrically surrounding the rod-shaped semiconductor core. A light emitting surface,
One end side of the said semiconductor core of the said rod-shaped light emitting element is exposed , The manufacturing method of the light-emitting device characterized by the above-mentioned . In the manufacturing method of the light-emitting device according to claim 1,
In the arranging step, the plurality of light emitting elements are collectively arranged on the same substrate. In the manufacturing method of the light-emitting device of Claim 1 or 2,
A wiring pattern for wiring the plurality of light emitting elements is formed on the substrate,
A method for manufacturing a light emitting device, wherein the wiring pattern is not formed in a cutting region of the substrate in the substrate dividing step. In the manufacturing method of the light-emitting device of Claim 1 or 2,
A wiring pattern for wiring the plurality of light emitting elements is formed on the substrate,
A method for manufacturing a light emitting device, wherein the wiring pattern that does not affect electrical connection even if the substrate is cut in the substrate dividing step is formed in a cutting region of the substrate. In the manufacturing method of the light-emitting device as described in any one of Claim 1 to 4,
A method for manufacturing a light emitting device, wherein the light emitting element is not disposed in a cutting region of the substrate in the substrate dividing step. In the manufacturing method of the light-emitting device as described in any one of Claim 1 to 4,
A method for manufacturing a light-emitting device, wherein a light-emitting element that does not affect a desired light emission amount even when cut in the substrate dividing step is disposed in a cutting region of the substrate among the plurality of light-emitting elements. In the manufacturing method of the light-emitting device as described in any one of Claim 1-6,
A phosphor coating step of coating a phosphor on the substrate after the placement step and the wiring step and before the substrate dividing step;
A method for manufacturing a light emitting device, comprising: a protective film application step of applying a protective film on the substrate after the phosphor application step. In the manufacturing method of the light-emitting device according to claim 7,
In the phosphor coating step, the phosphor is selectively coated on a region where the plurality of light emitting elements are arranged. In the manufacturing method of the light-emitting device as described in any one of Claim 1-8,
A method of manufacturing a light-emitting device, wherein 100 or more of the light-emitting elements are arranged on each of the divided substrates. A method for manufacturing a light emitting device according to any one of claims 1 to 9,
In the substrate dividing step, the substrate is divided into at least two types of divided substrates having different shapes. In the manufacturing method of the light-emitting device as described in any one of Claim 1-10,
The arranging step of arranging the plurality of light emitting elements on the substrate includes
A substrate creating step of creating the substrate having at least a first electrode and a second electrode on a mounting surface;
An application step of applying a solution containing the plurality of light emitting elements on the substrate;
An arrangement step of applying a voltage to at least the first electrode and the second electrode, and arranging the plurality of light emitting elements at least at positions defined by the first electrode and the second electrode. A method for manufacturing a light-emitting device. In the manufacturing method of the light-emitting device according to claim 11,
At least the first electrode and the second electrode are used as electrodes for driving the plurality of light-emitting elements. The method of manufacturing a light emitting device according to any one of claims 1 1 2,
The method for manufacturing a light-emitting device, wherein the plurality of light-emitting elements are a plurality of elements formed on an epitaxial substrate, and each element is separated from the epitaxial substrate.

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