JP2023156400A - Light emitting element and display, and method for manufacturing the same - Google Patents

Abstract

To efficiently array light-emitting elements and manufacture image display.SOLUTION: A red light-emitting diode comprises a plurality of light-emitting layers each emitting red light, a plurality of P layers and N layers bonded to the light-emitting layers so that red light is emitted by the light-emitting layers when voltage is applied, the plurality of light-emitting layers and the plurality of P layers and N layers being bonded in sequence with respect to the T direction. When manufacturing an image display using a red light-emitting diode, the red light-emitting diode is scattered on the top surface of a guide member placed on the top surface of a substrate.SELECTED DRAWING: Figure 1

Description

The present invention relates to a light emitting element and a display device, and a method for manufacturing the light emitting element and display device.

An image display device using light emitting diodes (LEDs) is assembled by arranging a large number of small light emitting diodes, so-called micro light emitting diodes (hereinafter referred to as micro LEDs) in a matrix. Conventionally, red, blue, and green light-emitting diodes have different base materials and materials deposited on them, so these three color light-emitting diodes have been fabricated on the same base material using a semiconductor device manufacturing process. It is difficult to form. For this reason, when manufacturing a full-color image display device, it is necessary to individually manufacture a large number of micro-LEDs of these three colors and then individually arrange the micro-LEDs in a predetermined arrangement. As an example of the arrangement method, for example, Patent Document 1 has been proposed.

Japanese Patent Application Publication No. 2002-368282

According to the first aspect, a plurality of first light emitting layers that emit light of a first color and a plurality of second light emitting layers that emit light of a second color different from the first color are provided. and a plurality of semiconductor layers provided to sandwich each of the first light emitting layer and the second light emitting layer in a predetermined direction, the plurality of first light emitting layers and the plurality of second light emitting layers. A light emitting element is provided in which the layer and each of the plurality of semiconductor layers are sequentially lined up and bonded so as to be line symmetrical with respect to a center line in the predetermined direction.
According to the second aspect, the light emitting layer includes a plurality of first light emitting layers and a plurality of second light emitting layers, each of which emits light of a different wavelength, and when a voltage is applied, the light emitting layer emits the light. a plurality of semiconductor layers bonded to the light-emitting layer so that the plurality of semiconductor layers are provided to sandwich the first light-emitting layer in a predetermined direction, and first semiconductor layers having mutually different conduction types; and a second semiconductor layer, the plurality of semiconductor layers are provided to sandwich the second light emitting layer in the predetermined direction, and include a third semiconductor layer and a fourth semiconductor layer having different conduction types. , the light-emitting layer and the plurality of semiconductor layers include the first semiconductor layer, the first light-emitting layer, the second semiconductor layer, the third semiconductor layer, the second light-emitting layer, and the first semiconductor layer with respect to the predetermined direction. A light-emitting element is provided in which a light-emitting portion is formed in which four semiconductor layers, the second light-emitting layer, the third semiconductor layer, the second semiconductor layer, the first light-emitting layer, and the first semiconductor layer are arranged and bonded in this order. Ru.
According to the third aspect, a plurality of light-emitting layers each emitting light; a plurality of semiconductor layers bonded to the plurality of light-emitting layers so that the light is emitted by the plurality of light-emitting layers when a voltage is applied; Provided is a light emitting element in which a plurality of light emitting layers and a plurality of semiconductor layers are sequentially lined up and bonded in a predetermined direction.

According to a fourth aspect, there is provided a display device comprising the light emitting elements of the first to third aspects and a substrate on which wiring for supplying power to the light emitting layer is formed and to which the light emitting elements are bonded. Ru.

According to a fifth aspect, there is provided a manufacturing method for manufacturing the light emitting device according to any one of the first to third aspects, comprising arranging a plurality of light emitting layers and a plurality of semiconductor layers in a predetermined direction to form the light emitting device. A method for manufacturing a light emitting element is provided, which includes joining the joined light emitting element, and cutting the joined light emitting element in a direction intersecting a predetermined direction.

According to a sixth aspect, there is provided a manufacturing method for manufacturing the display device according to the fourth aspect, comprising scattering a plurality of light emitting elements on the substrate, and bonding the scattered light emitting elements and the substrate. A method of manufacturing a display device is provided, which includes the following steps.

(A) is an enlarged perspective view showing the three-color micro-LED according to the first embodiment, (B) is a view showing the red micro-LED in FIG. 1(A) and a modification thereof, and (C) is a diagram. 1(A) is an enlarged cross-sectional view showing a state in which the red micro-LEDs of FIG. 1(A) are arranged on a substrate. (A) is a front view showing an image display device according to the embodiment, and (B) is an enlarged view showing a part of the image display device in FIG. 2(A). It is a flowchart which shows an example of the manufacturing method of the image display apparatus based on the embodiment. (A) is a perspective view showing a state in which a guide member is placed above the substrate, and (B) is a perspective view showing a state in which the guide member is placed on the top surface of the substrate. (A) is a perspective view showing a state in which a large number of micro LEDs are scattered on the upper surface of a guide member, and (B) is a perspective view showing a state in which a large number of micro LEDs are arranged on an upper surface of a substrate. (A) is a perspective view showing the guide member removed from the board, (B) is an enlarged perspective view showing a modified three-color micro LED, and (C) is an enlarged perspective view showing another modified micro LED. It is a diagram. (A) is an enlarged view showing a part of an image display device according to yet another modification, (B) is a cross-sectional view of FIG. 7(A), and (C) is another diagram corresponding to FIG. 7(B). A cross-sectional view showing a modified example, (D) is a cross-sectional view corresponding to FIG. 7(B) of an example using the micro LED of FIG. 6(B). (A), (B), (C), and (D) are side views showing the first, second, third, and fourth micro LED units, respectively, according to the second embodiment. (A) is a front view showing an image display device using a first micro LED unit, and (B) is a front view showing an image display device using a second micro LED unit. (A) is a front view showing an image display device using a fourth micro LED unit, and (B) is an enlarged cross-sectional view of a part of FIG. 10(A). 7 is a flowchart illustrating an example of a method for manufacturing an image display device according to a second embodiment. (A) is an enlarged side view showing five wafers for light emitting diodes, and (B) is an enlarged side view showing a state in which the five wafers are bonded together. (A) is an enlarged side view showing a state in which the lowermost base material is separated from five wafers, and (B) is an enlarged side view showing a state in which a micro LED unit is cut out. (A) is a perspective view showing a state in which the first guide member is arranged above the substrate, and (B) is a perspective view showing a state in which a large number of micro LED units are scattered on the upper surface of the first guide member. (A) is a perspective view showing a state in which micro LED units are arranged in a large number of openings of the first guide member, (B) is an enlarged plan view showing a part of the image display device in FIG. 15(A), (C ) is an enlarged cross-sectional view showing a part of FIG. 15(B). (A) is an enlarged cross-sectional view showing a state in which a second guide member is arranged above the first guide member and a plurality of micro LED units are scattered above the second guide member, and (B) is an enlarged cross-sectional view of the plurality of micro LED units. FIG. 7 is an enlarged cross-sectional view showing a state in which the end portion is accommodated within the opening of the first guide member. (A) is an enlarged cross-sectional view showing a state in which the second guide member is moved relative to the first guide member in the X direction, and (B) is a plurality of micro LED units arranged in the opening of the first guide member. FIG. 3 is an enlarged cross-sectional view showing a state in which

The first embodiment will be described below with reference to FIGS. 1(A) to 6(A). Hereinafter, a light emitting diode will also simply be referred to as an LED.
FIG. 1A shows a light emitting diode (hereinafter referred to as red LED) 10R that generates red light according to the present embodiment, a light emitting diode (hereinafter referred to as blue LED) 10B that generates blue light, and a light emitting diode (hereinafter referred to as blue LED) 10B that generates green light. A light emitting diode (hereinafter referred to as green LED) 10G is shown. The shapes of the LEDs 10R, 10B, and 10G are each a rectangular parallelepiped with a square cross-sectional shape and a height (length) higher than the length of the side of the cross-section. As an example, the shape of the LEDs 10R, 10B, and 10G has a cross-sectional side length of about 20 to 100 μm, and a height of about 1.5 to 3 times the length of the side. That is, the LEDs 10R, 10B, and 10G are each micro LEDs. Furthermore, the red LED 10R has the largest cross-sectional area and the lowest height, the blue LED 10B has a smaller cross-sectional area and the highest height than the red LED 10R, and the green LED 10G has the smallest cross-sectional area and the lowest height. expensive. Note that the LEDs 10R, 10B, and 10G may have any shape as long as they have different shapes. In the following description, the height (length) direction of the LEDs 10R, 10B, and 10G is assumed to be the T direction.

In addition, the red LED 10R (red micro LED) includes, in order in the T direction, a first P-type semiconductor layer (hereinafter referred to as P layer) 12P1 (first semiconductor layer), a first light emitting layer 12R1, and an N-type semiconductor layer. It is formed by laminating 12N (hereinafter referred to as an N layer) (second semiconductor layer), a second light emitting layer 12R2, and a second P layer 12P2 (first semiconductor layer). The P layers 12P1 and 12P2 and the N layer 12N have different conduction types. Further, the light emitting layers 12R1 and 12R2 can also be considered as part of the semiconductor layer. Furthermore, lamination can also be referred to as joining multiple times. In this embodiment, the T direction is the bonding direction (stacking direction) of the light emitting layer and the semiconductor layer.

The light-emitting layer 12R1 (12R2) has, in order from the P layer 12P1 (12P2) toward the N layer 12N, a so-called p- layer, which has a lower hole density than the P layer 12P1 (12P2), and a so-called p- layer, which has a lower hole density than the N layer 12N. This is a stack of so-called n-layers with low electron density. Similarly, the blue LED 10B (blue micro LED) includes, in order in the T direction, a first P layer 14P1, a first light emitting layer 14B1, an N layer 14N, a second light emitting layer 14B2, and a second P layer 14P2. The green LED 10G (green micro LED) includes, in order in the T direction, a first P layer 16P1, a first light emitting layer 16G1, an N layer 16N, a second light emitting layer 16G2, and a second light emitting layer 16G2. It is formed by laminating P layers 16P2.

As an example, the red LED 10R is made of gallium phosphide (GaP (Zn, O)) or gallium aluminum arsenide (GaAlAs), which is made by adding zinc, oxygen, etc. to the surface of a base material made of gallium phosphide (GaP) or gallium arsenide (GaAs). The blue LED 10B is manufactured by forming a semiconductor layer (P layer, N layer) and a light emitting layer such as a semiconductor layer (P layer, N layer) and a light emitting layer. The green LED 10G is manufactured by forming a semiconductor layer such as gallium phosphide (GaP(N)) or InGaN doped with nitrogen or the like and a light emitting layer on the surface of a base material made of sapphire or SiC. Manufactured by In this way, the LED 10R and the LEDs 10B and 10G have different materials for the base material, semiconductor layer, and light emitting layer. Furthermore, the LEDs 10B and 10G may also have different materials for at least one of the base material, semiconductor layer, and light emitting layer. Note that the materials of the base material, semiconductor layer, and light emitting layer of the LEDs 10R, 10B, and 10G are arbitrary, and the materials of the base material, semiconductor layer, and light emitting layer of the LEDs 10R, 10B, and 10G may be the same.

As shown in FIG. 1(B), in the red LED 10R, the P layers 12P1, 12P2, and the N layer 12N are symmetrical (line symmetric) with respect to the straight line 18 that is the center in the T direction. Below, being symmetrical with respect to the straight line 18 that is the center in the T direction is also simply referred to as being symmetrical with respect to the T direction. In order to manufacture an image display device using the red LED 10R (details will be described later), as shown in FIG. When a positive voltage is applied to the P layers 12P1 and 12P2 through the wiring 28B and a negative voltage is applied to the N layer 12N (or grounded) through the wiring 28B, the light emitting layers 12R1 and 12R2 of the red LED 10R emit light in all directions ( Red light is generated in the direction (including the side direction). At this time, since the wide side surface of the red LED 10R faces the display direction, sufficient light intensity can be obtained in the display direction. Furthermore, since the two light-emitting layers 12R1 and 12R2 emit light at the same time, the light intensity is twice that of a light-emitting diode with one light-emitting layer. Furthermore, by varying the voltages applied to the P layers 12P1 and 12P2, it is also possible to control the balance of the light intensity of the red light output from the light emitting layers 12R1 and 12R2.

Furthermore, in the red LED 10R, since the P layers 12P1, 12P2 and the N layer 12N are symmetrical with respect to the T direction, even if the red LED 10R is installed on the substrate 22 inverted with respect to the T direction, the patterns of the wirings 28A to 28C will not be changed. Without any changes, and without changing the voltages applied to the wires 28A-28C, the red LED 10R emits light as before reversing direction. This also applies to the other LEDs 10B and 10G. Therefore, the LEDs 10R, 10B, and 10G can be efficiently arranged on the substrate 22.

Note that in the red LED 10R, the light emitting layers 12R1 and 12R2 are also symmetrical with respect to the T direction. For this reason, even if the red LED 10R is installed inverted with respect to the T direction, the color tone does not change.
In addition, instead of the red LED 10R, as shown in FIG. It is also possible to manufacture (use) a red LED 10RA formed by bonding two N layers 12N2 together. In other words, the red LED 10RA has a configuration in which the P layer and the N layer of the red LED 10R are exchanged. In the red LED 10RA, the N layers 12N1 and 12N2, the light emitting layers 12R1 and 12R2, and the P layer 12P are also symmetrical with respect to the T direction. Therefore, even if the red LED 10RA is installed on the substrate 22 in a reversed manner with respect to the T direction, the red LED 10RA emits light in the same manner as before the direction is reversed.

Next, FIG. 2(A) shows a full-color image display device 20 using LEDs 10R, 10B, and 10G (three-color micro-LEDs) according to this embodiment. The image display device 20 includes a display section in which a red LED 10R, a blue LED 10B, and a green LED 10G are arranged and fixed in a matrix on the upper surface of a substrate 22 made of a substantially rectangular insulator, and a large number of LEDs 10R, 10B, and 10G are turned on. / off and a control section 24 that individually controls light intensity. Note that in FIG. 2A and the drawings referred to below, the LEDs 10R, 10B, and 10G are shown much larger than their actual sizes for convenience of explanation. Hereinafter, the description will be made by taking the X-axis and Y-axis along the longitudinal direction and the lateral direction of the substrate 22, respectively. In this embodiment, as an example, the T direction, which is the joining direction of the LEDs 10R, 10B, and 10G, is parallel to the X axis (X direction). In this embodiment, the red LED 10R, the blue LED 10B, and the green LED 10G are each arranged at a predetermined pitch in the Y direction along a straight line parallel to the Y axis, and one row of red LEDs 10R, one row of blue LEDs 10B, and one row of green LEDs 10G They are arranged at a predetermined pitch in the X direction. The pitch of the arrangement of the LEDs 10R, 10B, and 10G in the X direction and the Y direction is, for example, about 100 μm to 200 μm, and the number of the arrangement of the LEDs 10R, 10B, and 10G in the X direction and the Y direction is about 1000, respectively. Note that the arrangement of the LEDs 10R, 10B, and 10G is arbitrary, and the LEDs 10R, 10B, and 10G may be arranged, for example, in a checkered pattern.

Further, as shown in FIG. 2(B), the P layers 12P1, 12P2, 14P1, 14P2 and 16P1, 16P2 ( Wirings 28A, 28C, 28D, 28F, 28G, 28I for applying a voltage to (see FIG. 1(A)) and a wiring 28B for applying a voltage to the N layers 12N, 14N, and 16N of the LEDs 10R, 10B, and 10G. , 28E, 28H are formed. In addition, thin disk-shaped terminal portions 26A, 26B, 26C, 26D, 26E, 26F, 26G, 26H, 26I are provided at the contact portions of the wirings 28A to 28I with the corresponding P layer 12P1, etc. or the N layer 12N, etc. It is formed. The terminal portions 26A to 26I are made of a material (for example, solder) that can be welded to the corresponding P layer or N layer by heating. Note that the wirings 28A to 28I may also be formed from a material that can be welded. The control unit 24 individually controls the voltage applied to the wirings 28A to 28I for each of the large number of LEDs 10R, 10B, and 10G, and for each of the two light emitting layers within each LED 10R, 10B, and 10G. This allows any image to be displayed in full color and in high definition on the display unit. Note that the terminal portions 26A to 26I (and the wirings 28A to 28I) may be formed from a conductive adhesive.

Next, an example of a method for manufacturing the LEDs 10R, 10B, and 10G (micro LEDs) and the image display device 20 of this embodiment will be described with reference to the flowchart in FIG. 3. For this manufacturing, a thin film forming device (not shown), a resist coater/developer, an exposure device that transfers and exposes the mask pattern onto the resist on the surface of the base material, an etching device, an inspection device, a dicing device, etc. are used. .

First, in step 102 of FIG. 3, a P layer, a light emitting layer, Three types of wafers are manufactured by laminating an N layer, a light emitting layer, and a P layer. Then, in step 104, the base material portions are separated (removed) from the wafers for the LEDs 10R, 10B, and 10G by etching or the like, and a large number of LEDs 10R, 10B, and 10G are cut out from the wafers for each color using a dicing device. As a result, a large number of red LEDs 10R, blue LEDs 10B, and green LEDs 10G are manufactured.

Furthermore, in step 106, the substrate 22 and guide member 30 of the image display device 20 are manufactured, as shown in FIG. 4(A). In areas 23R, 23B, and 23G on the upper surface of the board 22 where the LEDs 10R, 10B, and 10G are arranged (for example, the positions are predefined with reference to the ends of the board 22 in the X direction and the Y direction), there are wirings 28A, respectively. 28I, terminal portions 26A to 26I, etc. (see FIG. 2(B)) are formed. Furthermore, the control section 24 is also manufactured. The guide member 30 has approximately the same size as the substrate 22, and includes a rectangular opening 32R that can accommodate the red LED 10R and a blue LED in the same arrangement as the LED 10R, 10B, and 10G in FIG. 2(A). A rectangular opening 32B that can accommodate the LED 10B and a rectangular opening 32G that can accommodate the green LED 10G are formed in a matrix. The openings 32R, 32B, and 32G are formed slightly larger than the side shapes of the corresponding LEDs 10R, 10B, and 10G. In this embodiment, the LEDs 10R, 10B, and 10G have gradually elongated shapes, so when the LEDs 10R, 10B, and 10G are arranged so that their side surfaces are in contact with the substrate 22, the openings 32R, 32B, and 32G have the red LED 10R, Only the blue LED 10B and the green LED 10G can be accommodated.

When the guide member 30 is used only when arranging the LEDs 10R, 10B, and 10G on the substrate 22, and when the guide member 30 is removed after the arrangement is completed, the guide member 30 may be made of, for example, metal (aluminum, etc.) or ceramics. Good too. On the other hand, when the guide member 30 is left attached to the substrate 22, the guide member 30 may be made of synthetic resin or the like. The thickness of the guide member 30 around the openings 32R, 32B, and 32G is approximately the length of the side of the cross section of the green LED 10G, which has the smallest cross-sectional area.

Then, in step 108, the guide member 30 is moved relative to the board 22 so that the openings 32R, 32B, 32G of the guide member 30 are opposed to the regions 23R, 23B, 23G of the board 22 where the LEDs 10R, 10B, 10G are arranged. Then, as shown in FIG. 4(B), the guide member 30 is placed on the upper surface of the substrate 22. At this time, the longitudinal directions of the openings 32R, 32B, and 32G of the guide member 30 are parallel to the X direction. When removing the guide member 30 from the substrate 22 after arranging the LEDs 10R, 10B, and 10G, the guide member 30 may be held at a slight distance from the substrate 22 by, for example, a support member (not shown). Further, when the guide member 30 is left attached to the substrate 22, the guide member 30 may be fixed to the substrate 22 by adhesive or the like. Note that the steps 102 and 104 for manufacturing the LED 10R, etc. and the steps 106 and 108 for manufacturing the substrate and the like may be performed substantially in parallel.

In the next step 112, as shown in FIG. 5(A), a method such as tilting a stocker for accommodating a large number of LEDs 10R, 10B, and 10G (not shown) on the upper surface of the guide member 30 arranged on the substrate 22. Then, a large number of LEDs 10R, 10B, and 10G are scattered (dispersed). As a result, as shown in FIG. 5(B), the red LED 10R, the blue LED 10B, and the green LED 10G are housed in the openings 32R, 32B, and 32G of the guide member 30, respectively, with their side surfaces in contact with the substrate 22. In the next step 114, the LEDs 10R, 10B, 10G on the upper surface of the guide member 30 and not accommodated in the openings 32R, 32B, 32G are removed. Note that this step 114 may be performed after the LEDs 10R, 10B, and 10G are fixed to the board 22 as described later. Then, in step 116, an inspection device (not shown) is used to inspect whether the LEDs 10R, 10B, 10G corresponding to all the openings 32R, 32B, 32G of the guide member 30 are accommodated. If there are openings 32R, 32B, and 32G that do not accommodate LEDs 10R, 10B, and 10G, steps 112 and 114 are repeated until all of the openings 32R, 32B, and 32G accommodate LEDs 10R, 10B, and 10G. .

When the LEDs 10R, 10B, and 10G are accommodated in all the openings 32R, 32B, and 32G, the process moves to step 118, and the substrate 22 is heated from the bottom surface. At this time, the upper portions of the LEDs 10R, 10B, and 10G may be biased toward the substrate 22 using a flexible member (not shown). As a result, the terminal portions 26A to 26I (and wirings 28A to 28I) of the substrate 22 shown in FIG. The P layer and the N layer are fixed to the upper surface of the substrate 22 while being electrically connected to the corresponding wirings 28A to 28I. Thereafter, in step 120, it is determined whether or not to remove the guide member 30. If the guide member 30 is to be removed, the process proceeds to step 122, and as shown in FIG. 6(A), the guide member 30 is removed from the substrate 22. Remove. After that, in step 124, the image display device 20 is manufactured by installing a cover glass to cover the LEDs 10R, 10B, and 10G. If guide member 30 is not removed, operation proceeds from steps 120 to 124. Note that if the terminal portions 26A to 26I (and the wirings 28A to 28I) are formed from a conductive adhesive, the step of heating the substrate 22 in step 118 can be omitted.

As described above, in this embodiment, by scattering a large number of LEDs 10R, 10B, and 10G on the upper surface of the guide member 30, three types of LEDs 10R, 10B, and 10G are efficiently arranged in a targeted arrangement on the upper surface of the substrate 22. can. At this time, since the P layers 12P1, 12P2, etc. and the N layers 12N, etc. (semiconductor layers) of the LEDs 10R, 10B, 10G are symmetrical with respect to the T direction, the LEDs 10R, 10B, etc. , 10G are housed inverted with respect to the T direction (X direction), the LEDs 10R, 10B, and 10G can emit light in the same way without changing the voltages applied to the wirings 28A to 28I. Therefore, the image display device 20 can be manufactured more efficiently.

As described above, the red LED 10R (micro LED) of this embodiment includes a plurality of light emitting layers 12R1 and 12R2, each of which emits red light, and a structure in which the light emitting layers 12R1 and 12R2 emit red light when a voltage is applied. A plurality of P layers 12P1, 12P2 (first semiconductor layer) and an N layer 12N (second semiconductor layer) bonded to light emitting layers 12R1, 12R2; This is a light emitting element in which 12P1, 12P2 and an N layer 12N (semiconductor layer) are lined up and bonded in order in the T direction (junction direction). Moreover, the blue LED 10B and the green LED 10G are also similar light emitting elements.

When manufacturing the image display device 20 using the LEDs 10R, 10B, and 10G, the LEDs 10R, 10B, and 10G are simply scattered on the upper surface of the guide member 30 on the substrate 22, and the LEDs 10R, 10B, and 10G are connected to the opening of the guide member 30. 32R, 32B, and 32G, the LEDs 10R, 10B, and 10G can be efficiently arranged in a targeted arrangement. Note that, for example, if the P layers 12P1, 12P2 and the N layer 12N (semiconductor layer) of the red LED 10R are not symmetrical with respect to the T direction, after the red LED 10R is installed on the substrate 22, the controller 24 controls the red LED 10R. The direction in which the current flows (the arrangement state of the P layers 12P1, 12P2 and the N layer 12N) may be detected, and the voltage supplied to the red LED 10R may be changed based on the detection result.

Further, in the image display device 20 of the present embodiment, wirings 28A to 28I for supplying power to the LEDs 10R, 10B, and 10G and their light emitting layers 12R1, 12R2, 14B1, 14B2, 16G1, and 16G2 are formed, and the LEDs 10R, 10B, and , 10G are bonded to each other. The image display device 20 can be efficiently manufactured because the LEDs 10R, 10B, and 10G can be arranged on the substrate 22 with high precision and efficiency.

Further, the method for manufacturing the red LED 10R of this embodiment includes manufacturing a wafer by arranging and bonding the light emitting layers 12R1 and 12R2, the P layers 12P1 and 12P2, and the N layer 12N in the T direction so as to form the red LED 10R. The process includes step 102 and step 104 of cutting the wafer including the bonded red LEDs 10R in a direction perpendicular to the T direction. According to this manufacturing method, the red LED 10R having a plurality of light emitting layers 12R1 and 12R2 can be efficiently manufactured.

Further, the method for manufacturing the image display device 20 of this embodiment includes a step 112 of scattering a plurality of LEDs 10R, 10B, 10G on the substrate 22, and welding the scattered LEDs 10R, 10B, 10G and the substrate 22 by heating. and step 118 of joining by. According to this manufacturing method, since the LEDs 10R, 10B, and 10G can be efficiently arranged in a targeted arrangement by scattering the LEDs 10R, 10B, and 10G, the image display device 20 can be manufactured efficiently.

Note that the above-described embodiment can be modified as follows.
First, in the embodiment described above, when scattering the LEDs 10R, 10B, and 10G on the upper surface of the guide member 30 (substrate 22), the LEDs 10R, 10B, and 10G may be neutralized by an ionizer (not shown). This can prevent the LEDs 10R, 10B, and 10G from adhering to areas other than the openings 32R, 32B, and 32G of the guide member 30.

Further, in the above embodiment, the light emitting layers 12R1, 12R2, etc. of the LEDs 10R, 10B, 10G are two layers, and the semiconductor layers of the P layers 12P1, 12P2 and the N layer 12N are three layers, but the light emitting layers are three or more layers. You can also do this. When the light emitting layer is composed of three or more N layers (N is an integer of three or more), the number of semiconductor layers may be (N+1) or more. When the number of light emitting layers is N (N is an even number of 4 or more), the number of semiconductor layers may be (N+1). Further, when the number of layers of the light emitting layer is N (N is an odd number of 3 or more and/or an even number of 4 or more), the number of semiconductor layers is (N+1) or more.

Further, although the LEDs 10R, 10B, and 10G have a rectangular parallelepiped shape, it is also possible to manufacture a cylindrical red LED 11R, blue LED 11B, and green LED 11G, as shown in FIG. 6(B). For example, the red LED 11R is formed by stacking a P layer 13P1, a light emitting layer 13R1, an N layer 13N, a light emitting layer 13R2, and a P layer 13P2 in order in the T direction. Since the semiconductor layers of the LEDs 11R, 11B, and 11G are also symmetrical with respect to the T direction, the same effects as in the above embodiment can be obtained. Further, as an example, the green LED 11G has the largest cross-sectional area and the lowest height, the blue LED 11B has the smallest cross-sectional area and the highest height, and the red LED 11R has an intermediate cross-sectional area and an intermediate height. In this way, since the LEDs 11R, 11B, and 11G have different shapes, when arranging the LEDs 11R, 11B, and 11G on the substrate 22, the guide member 30 has an opening that can accommodate the LEDs 11R, 11B, and 11G. By using the guide member, the LEDs 11R, 11B, and 11G can be efficiently arranged in a targeted arrangement. Furthermore, as shown in FIG. 6(C), it is also possible to manufacture a prismatic red LED 11RA having a regular hexagonal cross-sectional shape. Furthermore, it is also possible to manufacture micro-LEDs having an arbitrary polygonal cross-sectional shape.

Furthermore, in the embodiment described above, the LEDs 10R, 10B, and 10G are scattered on the upper surface of the guide member 30. On the other hand, as shown in FIG. 7(A) corresponding to FIG. 2(B), LEDs 10R, 10B, and 10G can be installed in the areas on the top surface of the board 22 where LEDs 10R, 10B, and 10G are installed, respectively. Recesses 22a, 22b, and 22c may be formed in advance. FIG. 7(B) is a cross-sectional view of FIG. 7(A), and as shown in FIG. 7(B), the recesses 22a, 22b, 22c have the P layer and N layer of the LEDs 10R, 10B, and 10G, respectively. Terminal portions 26A to 26I are formed at opposing positions, and the terminal portions 26A to 26I are connected to the control portion 24 in FIG. 2A via wiring 28A and the like. In this modification, only the LEDs 10R, 10B, and 10G can be accommodated in the recesses 22a, 22b, and 22c, respectively. Therefore, when a large number of LEDs 10R, 10B, and 10G are scattered on the upper surface of the substrate 22, the recesses 22a, 22b, and 22c accommodates only LEDs 10R, 10B and 10G, respectively. Therefore, the LEDs 10R, 10B, and 10G can be efficiently arranged on the upper surface of the substrate 22 in a targeted arrangement without using the guide member 30.

In this modification, the LEDs 10R, 10B, and 10G are arranged in the recesses 22a, 22b, and 22c so that their respective side surfaces are in contact with the substrate 22. Therefore, an image can be displayed with light of sufficient intensity emitted from the side surfaces of the LEDs 10R, 10B, and 10G. Further, as shown in FIG. 7(C), recesses 22d, 22e, and 22f are provided on the upper surface of the substrate 22 to accommodate the LEDs 10R, 10B, and 10G, respectively, so that the longitudinal direction (T direction) is perpendicular to the upper surface. It is also possible. Note that in FIG. 7C, the LEDs 10R, 10B, and 10G are shown protruding from the top surface of the board 22 and housed, but the recesses are formed in accordance with the longitudinal lengths of the LEDs 10R, 10B, and 10G. The lengths (depths) in the Z direction of 22d, 22e, and 22f may be set. Furthermore, when setting the lengths (depths) in the Z direction of the recesses 22d, 22e, and 22f, it is not necessary to set them so that all the light emitting layers of the LEDs 10R, 10B, and 10G emit light; Of the 10G light emitting layers, the number of light emitting layers in contact with the substrate may be the same for LEDs 10R, 10B, and 10G. Note that when the radial lengths of the LEDs 10R, 10B, and 10G are shorter than the radial lengths of the recesses 22d, 22e, and 22f, for example, the LED 10G and the recess 22d are inserted into the recess 22d that should not be accommodated. Sometimes. However, in this case, even if the radial lengths are greatly different, there is a low possibility that the LED 10G in the recess 22d will come into contact with the substrate 22, and the LED 10G will not emit light. Further, even if the LED 10G is inserted into the recess 22d, the LED 10G falls out from the recess 22d because the radial lengths are greatly different. Therefore, even if an LED having a different radial length (eg, 10G) is accommodated in a recess that should not be accommodated (eg, the recess 22d), there is almost no possibility that the LED will emit light.

In addition, as shown in FIG. 7(D), when using the cylindrical LEDs 11R, 11B, and 11G shown in FIG. It is also possible to form recesses 22h, 22i, and 22g. In this example, when the LEDs 11R, 11B, and 11G are scattered, the LEDs 11R, 11B, and 11G are efficiently arranged in the recesses 22h, 22i, and 22g of the substrate 22, respectively.

Next, a second embodiment will be described with reference to FIGS. 8(A) to 17(B). Note that in FIGS. 8(A) to 17(B), parts corresponding to those in FIGS. 1(A) to 6(A) are designated by the same reference numerals, and detailed explanation thereof will be omitted.
FIG. 8A shows a first micro LED unit (hereinafter referred to as an LED unit) 42 in which a plurality of micro LEDs that respectively generate red light, blue light, and green light are combined according to this embodiment. The LED unit 42 includes a first light emitting diode (hereinafter referred to as red LED) 40R (first light emitting unit) that generates red light, and a first light emitting diode (hereinafter referred to as blue LED) 40B (first light emitting unit) that generates blue light. 2 light emitting section), a first light emitting diode (hereinafter referred to as green LED) 40G that generates green light (third light emitting section), a second green LED 40G1 (third light emitting section), a second blue LED 40B1 (second A light emitting part) and a second red LED 40R1 (first light emitting part) are bonded in the T direction, which is the bonding direction between the light emitting layer and the semiconductor layer of each LED. The red LED 40R is formed by stacking a P layer 12P1 (first layer), a light emitting layer 12R1, and an N layer 12N (second layer) in order in the T direction, and the blue LED 40B is formed by stacking a P layer 14P1 in order in the T direction. (third layer), a light emitting layer 14B1, and an N layer 14N (fourth layer). It is formed by laminating layers 16N (sixth layer).

Further, the green LED 40G1, the blue LED 40B1, and the red LED 40R1 are obtained by inverting the green LED 40G, the blue LED 40B, and the red LED 40R with respect to the T direction, respectively. In the LED unit 42, the green LEDs 40G and 40G1 (third light emitting section) have an N layer 16N (second semiconductor layer) between the N layer 12N (second semiconductor layer) of the green LED 40G1 and the light emitting layer 16G1 of the green LED 40G. have With this configuration, even if the green LEDs 40G and 40G1 are arranged at the center of the LED unit 42, the semiconductor layers and light emitting layers of the green LEDs 40G and 40G1 can be arranged symmetrically with respect to the T direction.

The LED unit 42 has a square cross-sectional shape and a rectangular parallelepiped shape elongated in the T direction. In addition, in the LED unit 42, the P layers 12P1, 14P1, 16P1, 16P1, 14P1, 12P1 and the N layers 12N, 14N, 16N, 16N, 14N, 12N are symmetrical (line symmetrical) with respect to the straight line 18A that is the center in the T direction. ). In this case, when installing the LED unit 42 on the substrate 22A (see FIG. 9(A)) in order to manufacture an image display device using the LED unit 42, the LED unit 42 is inverted with respect to the T direction on the substrate 22. Even when installed, the LED unit 42 emits light in three colors without changing the wiring pattern (not shown) or changing the voltage applied to the wiring. Therefore, the LED units 42 can be efficiently arranged on the substrate 22.

Further, in the LED unit 42, the red, blue, and green light emitting layers 12R1, 14B1, 16G1, 16G1, 14B1, and 12R1 are also symmetrical with respect to the T direction. For this reason, even if the LED unit 42 is installed inverted with respect to the T direction, the color tone does not change. Furthermore, green LEDs 40G and 40G1 are arranged at the center of the LED unit 42. Among red, blue, and green lights, green light (centered at 555 nm) has the highest relative luminous efficiency, so by arranging the green LEDs 40G and 40G1 in the center, the center becomes brighter and the brightness is well balanced. However, the LED unit 42 can individually control the voltage supplied to the red LEDs 40R, 40R1, the blue LEDs 40B, 40B1, and the green LEDs 40G, 40G1, and the light intensity of the red LEDs 40R, 40R1, the blue LEDs 40B, 40B1, and the green LEDs 40G, 40G1. can be controlled individually, so it is not necessarily necessary to arrange the green LEDs 40G and 40G1 in the center.

Next, FIG. 8(B) shows the second LED unit 42A. The LED unit 42A is made by joining a first red LED 10R, a first blue LED 10B, a green LED 10G, a second blue LED 10B, and a second red LED 10R in the T direction. However, the second blue LED 10B and the second red LED 10R are reversed in the T direction with respect to the first blue LED 10B and the first red LED 10R, respectively. Note that, as explained in the first embodiment, the semiconductor layer and the light emitting layer of the red LED 10R and the blue LED 10B are symmetrical with respect to the T direction, so the second blue LED 10B and the second red LED 10R each have two P layers. and the signs of the two light-emitting layers are switched.

In the LED unit 42A, the P layers 12P1, 12P2, . . . 12P2, 12P1 and the N layers 12N, . Furthermore, in the LED unit 42A, the three color light emitting layers 12R1, 12R2, 14B1, 14B2, 16G1, 16G2, 14B2, 14B1, 12R2, 12R1 are symmetrical with respect to the T direction. In this case, when manufacturing an image display device using the LED unit 42A, even if the LED unit 42A is installed on the board inverted with respect to the T direction, the wiring pattern (not shown) is not changed. The LED unit 42A emits three colors of light without changing the applied voltage. Therefore, the LED units 42A can be efficiently arranged on the board. Furthermore, the color tone does not change.

Moreover, FIG. 8(C) shows the third LED unit 42B. The LED unit 42B is made by joining a first red LED 40R, a first blue LED 40B, a green LED 10G, a second blue LED 40B1, and a second red LED 40R1 in the T direction. In the LED unit 42B, the P layers 12P1, 14P1, . . . 14P1, 12P1 and the N layers 12N, 14N, . Furthermore, in the LED unit 42B, the three color light emitting layers 12R1, 14B1, 16G1, 16G2, 14B1, and 12R1 are symmetrical with respect to the T direction. In this case, when manufacturing an image display device using the LED unit 42B, even if the LED unit 42B is installed on the board inverted with respect to the T direction, the wiring pattern (not shown) is not changed. The LED unit 42B emits three colors of light without changing the applied voltage. Furthermore, the color tone does not change.

Moreover, FIG. 8(D) shows the fourth LED unit 44. The LED unit 44 includes a first red LED 10R, a spacer section 46A, a first blue LED 10B, a spacer section 46B, a green LED 10G, a spacer section 46C, a second blue LED 10B, a spacer section 46D, and a second red LED 10R. It is joined in the direction. The spacer parts 46A to 46D having the same configuration and the same size are, for example, base materials or parts thereof used when manufacturing the LEDs 10R, 10B, and 10G, and the spacer parts 46A to 46D are parts that do not generate light ( This is the black part or so-called black matrix part). Further, in the second blue LED 10B and the second red LED 10R, the signs of the two P layers and the two light emitting layers are switched with respect to the first blue LED 10B and the first red LED 10R, respectively. The blue LED 10B (second light emitting section) includes a P layer 12P1 (third layer), a light emitting layer 14B1, an N layer 14N (fourth layer), a light emitting layer 14B2, and a P layer 14P2 (third layer) arranged in order in the T direction. The configuration is as follows. Further, in the blue LED 10B, a P layer 12P1 (third layer) and a light emitting layer 14B1 are arranged on one end side in the T direction, and a light emitting layer 14B2 and a P layer 14P2 (third layer) are arranged on the other end side. The LED unit 44 has a square cross section with a width of, for example, about 20 to 100 μm, and a rectangular prism shape with a height (length) of about 300 to 700 μm.

In the LED unit 44, the P layers 12P1, 12P2, . . . 12P1 and the N layers 12N, 14N, . Further, in the LED unit 44, the three color light emitting layers 12R1, 12R2, 14B1, 14B2, 16G1, 16G2, 14B2, 14B1, 12R2, 12R1 and the spacer parts 46A to 46D are symmetrical with respect to the T direction. In this case, when manufacturing an image display device using the LED unit 44, even if the LED unit 44 is installed on the board inverted with respect to the T direction, the wiring pattern (not shown) is not changed. The LED unit 44 emits three colors of light without changing the applied voltage. Therefore, the LED units 44 can be efficiently arranged on the board. Furthermore, the color tone does not change.

As described above, the LED units 42, 42A, 42B, and 44 each have a square cross-sectional shape and a rectangular parallelepiped shape elongated in the T direction. Note that the external shape of the LED units 42, 42A to 42C, and 44 may be an elongated columnar shape or an elongated polygonal columnar shape. Further, in the LED units 42, 42A to 42C, 44, if the semiconductor layers (P layer, N layer) and the light emitting layers of each color are arranged symmetrically with respect to the T direction, the semiconductor layers (P layer, N layer) The number and arrangement of the light-emitting layers of each color are arbitrary.

FIG. 9A shows a full-color image display device 20A using the LED unit 42 according to this embodiment. FIG. 9B shows a full-color image display device 20B using the LED unit 42B according to this embodiment. FIG. 10A shows a full-color image display device 20C using the LED unit 44 according to this embodiment. The image display devices 20A, 20B, and 20C each include a display section in which LED units 42, 42A, and 44 are arranged and fixed in a matrix on the upper surface of a substantially rectangular insulating substrate 22A, 22B, and 22C, respectively, and a large number of LED units. It includes control units 24A, 24B, and 24C that individually control on/off and light intensity of the LED units 42, 42A, and 44. Note that in FIGS. 9(A), 9(B), 10(A), and the drawings referred to below, the LED units 42, 42A, and 44 are shown considerably enlarged than their actual sizes for convenience of explanation. There is. Hereinafter, the description will be made by taking the X-axis and Y-axis along the longitudinal direction and lateral direction of the substrates 22A, 22B, and 22C, respectively. In this embodiment, as an example, the T direction, which is the joining direction of the LED units 42, 42A, and 44, is the X direction.

For example, the control unit 24C can also individually control the light intensity of any of the five LEDs 10R, 10B, and 10G in each LED unit 44. The control unit 24A can individually control the light intensity of the light emitting layers in the LEDs 40R, 40R1, 40G, 40G1, 40B, and 40B1 in each LED unit 42, respectively.

In this embodiment, the LED units 42, 42A, 44 are each arranged at a predetermined pitch in the X direction along a straight line parallel to the X axis, and the two rows of LED units 42, 42A, 44 arranged in the X direction are They are arranged in a checkered pattern shifted by half a pitch in the X direction. The pitch of the arrangement of the LED units 42, 42A, 44 in the X direction is, for example, about 1.1 times the length (height) of the LED units 42, 42A, 44 in the X direction. The pitch of the arrangement in the Y direction is, for example, approximately 1.5 to 2 times the width of the cross-sectional shape of the LED units 42, 42A, and 44. The numbers of LED units 42, 42A, and 44 arranged in the X direction and Y direction are approximately 200 and 1000, respectively. Note that the arrangement and number of LED units 42, 42A, 44 are arbitrary; for example, one row of LED units 42, 42A, 44 arranged in the X direction may be arranged in parallel to the Y direction. .

Further, as shown in FIG. 10B, in the area where the LED unit 44 is installed on the upper surface of the substrate 22C of the image display device 20C, the P layer 12P1 of the LEDs 10R, 10B, 10G, 10B, and 10R of the LED unit 44 is provided. , 12P2, . . . 12P2 and the N layers 12N, 14N, . . . 12N (see FIG. 8(D)). Furthermore, between the wirings 28A to 28I and the corresponding LEDs 10R, 10B, and 10G, terminal portions ( (not shown) is formed. The control unit 24C individually controls the voltages applied to the wirings 28A to 28I and the like for each of the two light emitting layers in the LEDs 10R, 10B, and 10G in the large number of LED units 44. This allows any image to be displayed in full color and in high definition on the display unit. Similarly, in the image display devices 20A and 20B, any image can be displayed in full color on the display section.

Next, an example of a method for manufacturing the LED unit 44 and image display device 20C of this embodiment will be described with reference to the flowchart of FIG. 11. For this manufacturing, a manufacturing apparatus (not shown) similar to that of the first embodiment is used. Note that the LED units 42, 42A, 42B and the image display devices 20A, 20B can also be manufactured in the same process.

First, in step 102A of FIG. 11, three types of disk-shaped substrates are used to manufacture three types of LEDs 10R, 10B, and 10G that constitute the LED unit 44 of FIG. 8(D) using a semiconductor element manufacturing process. As shown in FIG. 12(A), on the surfaces of the materials 48A, 48B, and 48C, P layers 12PA, 14PA, 16PA, light emitting layers 12RA, 14BA, 16GA, N layers 12NA, 14NA, 16NA, and light emitting layers 12RB, 14BB, respectively. , 16GB, and P layers 12PB, 14PB, and 16PB are stacked in the T direction. As a result, two wafers 46R1 and 46R2 (first substrate) for red micro LEDs, two wafers 46B1 and 46B2 (second substrate) for blue micro LEDs, and one wafer for green micro LEDs. A wafer 46G (third substrate) is manufactured.

Then, in step 130, as shown in FIG. 12(B), five wafers 46R1, 46B1, 46G, 46B2, and 46R2 are bonded together via insulating adhesives 48A, 48B, 48C, and 48D. Furthermore, in step 132, as shown in FIG. 13(A), the base material 48A of the lowermost red LED wafer 46R1 is separated (removed) by etching or the like to form an aggregate 50 of a large number of LED units 44. The assembly 50 is manufactured and cut along the dotted line cut portion 52 using a dicing device (not shown). As a result, as shown in FIG. 13(B), a large number of LED units 44 having a structure in which the LEDs 10R, 10B, 10G and spacer parts 46A to 46D are stacked can be manufactured. Parts of the base materials 48B, 48C, 48B, and 48A of the wafers 46B1, 46G, 46B2, and 46R2 serve as spacer portions 46A to 46D, respectively. According to this method of manufacturing the LED unit 44, the LED unit 44 having a multilayer structure can be efficiently manufactured.

Then, in step 106A, as shown in FIG. 14(A), the substrate 22C of the image display device 20C, the first guide member 30A, and the second guide member 30B of FIG. 16(A) are manufactured. In the area 23 on the upper surface of the board 22C where the LED unit 44 is arranged (for example, the position is predefined with reference to the ends of the board 22C in the X direction and the Y direction), wirings 28A to 28I and terminal portions ( (see FIG. 10(B)) is formed. Furthermore, the control section 24C is also manufactured. The guide member 30A has approximately the same size as the substrate 22C, and the guide member 30A has a plurality of rectangular openings 52 that can accommodate the LED units 44 in the same arrangement as the LED units 44 in FIG. 10(A). It is formed in a matrix. The opening 52 is formed slightly larger than the shape of the side surface of the corresponding LED unit 44.

In this embodiment, as an example, the guide member 30A is left attached to the substrate 22. Note that the guide member 30A may be removed from the board 22 after the LED unit 44 is attached. The thickness of the guide member 30A around the opening 52 is approximately the width of the side of the cross section of the LED unit 44. In addition, between the two adjacent openings 52 of the guide member 30A, as shown in FIGS. 52 is formed with inclined portions 54C and 54D that gradually become lower in the Y direction. The LED unit 44 is smoothly accommodated in the opening 52 by the inclined portions 54A to 54C.

Then, in step 134, the guide member 30A is positioned with respect to the substrate 22C so that the opening 52 of the guide member 30A faces the area 23 where the LED unit 44 of the substrate 22C is arranged, and as shown in FIG. As shown in FIG. 2, a guide member 30A is arranged and fixed on the upper surface of the substrate 22C. As an example, when the second guide member 30B to be described later is not used, a large number of LED units 44 are installed on the upper surface of the guide member 30A as shown in FIG. As shown in FIG. 15(A), the LED units 44 are arranged on the upper surface of the substrate 22C within the multiple openings 52 of the guide member 30A so that their side surfaces are in contact with the upper surface of the substrate 22C. As shown in FIGS. 15(B) and 15(C), the LED units 44 at positions B1 and B2 are smoothly housed in the corresponding openings 52 via the inclined portions 54A, 54B of the guide member 30A, respectively. Operation then proceeds to step 118A of FIG.

Here, a case will be described in which a second guide member 30B is used as shown in FIG. 16(A) in order to more efficiently accommodate the LED unit 44 in the opening 52 of the guide member 30A. The second guide member 30B has a large number of openings through which the LED units 44 can pass, the longitudinal direction of which is arranged in the normal direction of the upper surface of the substrate 22C, in the same arrangement as the large number of openings 52 of the first guide member 30A. 56 is formed. In other words, the opening 56 has a shape slightly larger than the cross-sectional shape of the LED unit 44. Furthermore, sloped portions 58A and 58B that gradually decrease toward the opening 56 are formed in the area adjacent to the opening 56 on the top surface of the second guide member 30B, and the bottom surface of the second guide member 30B (opposed to the substrate 22C Slanted portions 58C and 58D (which may be chamfered portions) smaller than the sloped portions 58A and 58B are formed in the region adjacent to the opening 56 of the surface of the slanted surface.

At this time, in step 136, the end of the opening 56 of the second guide member 30B in the -X direction almost coincides with the end of the opening 52 of the first guide member 30A in the -X direction, and The second guide member 30B is positioned with respect to the first guide member 30A so that the distance between the bottom surface of the guide member 30B and the substrate 22C is slightly smaller than the height of the LED unit 44. At this time, a drive unit 60 (not shown) is used that moves the second guide member 30B in the X direction, the Y direction, and the normal direction of the substrate 22C.

In the next step 138, as shown in FIG. 16(A), a large number of LED units 44 are scattered on the upper surface of the second guide member 30B disposed above the substrate 22C and the first guide member 30A. As a result, a large number of LED units 44 each pass through the opening 56 via the inclined portions 58A, 58B of the second guide member 30B. As shown in FIG. 16(B), the ends of the LED units 44 that have passed through the openings 56 come into contact with the ends of the openings 52 in the -X direction of the first guide member 30A. In this state, in step 140, the drive unit 60 moves the second guide member 30B relative to the first guide member 30A in the +X direction indicated by arrow B3. Then, as the second guide member 30B moves, the LED units 44 in the openings 52 of the first guide member 30A rotate clockwise as shown in FIG. 17(A), and finally, as shown in FIG. As shown in B), the LED units 44 in the opening 52 of the first guide member 30A are housed in the opening 52 with their respective side surfaces in contact with the substrate 22C. As a result, a large number of LED units 44 on the upper surface of the substrate 22C are arranged in a targeted arrangement.

In the next step 118A, by heating the substrate 22C from the bottom, the terminal portion (not shown) of the substrate 22C (and the wirings 28A to 28I in FIG. The LED unit 44 is fixed to the upper surface of the substrate 22C by welding to the P layer or the N layer. Thereafter, in step 124A, the second guide member 30B is removed and a cover glass covering the LED unit 44 is installed, thereby manufacturing the image display device 20C.

In this manner, in this embodiment, by scattering a large number of LED units 44 on the upper surface of the second guide member 30B, the LEDs can be placed in the target arrangement within the opening 52 of the first guide member 30A on the upper surface of the substrate 22C. The units 44 can be arranged efficiently. At this time, in the LED unit 44, since the P layers 12P1, 12P2, ... 12P1 and the N layers 12N, 14N, ... 12N are symmetrical with respect to the T direction, the LED unit 44 is symmetrical in the T direction ( Even if the LED unit 44 is housed inverted in the X direction), the LEDs 10R, 10B, and 10G of the LED unit 44 can emit light in the same way without changing the voltages applied to the wirings 28A to 28I. Therefore, the image display device 20 can be manufactured more efficiently.

Furthermore, since the three color light emitting layers 12R1, 12R2, ... 12R1 of the LED unit 44 are also symmetrical with respect to the T direction, even if the LED unit 44 is housed inverted in the T direction with respect to the opening 52 of the guide member 30A. , the color tone of the image display device 20C does not change.
As described above, the LED unit 44 of this embodiment includes a plurality of light emitting layers 12R1, 12R2, 14B1, 14B2, 16G1, and 16G2 that each emit red light, blue light, or green light, and when a voltage is applied, A plurality of P layers 12P1, 12P2, etc. and N layers 12N, 14N, etc. (semiconductor layers) bonded to the light emitting layers 12R1,...16G2 so that light is emitted by the light emitting layers 12R1,...16G2, and a plurality of light emitting layers. 12R1, etc., and a plurality of P layers 12P1, etc., and N layers 12N, etc. (semiconductor layers) are sequentially lined up and bonded in the T direction (junction direction).

When manufacturing the image display device 20C using the LED units 44, the LED units 44 can be efficiently arranged in a targeted arrangement by simply scattering the LED units 44 on the upper surface of the guide member 30A or 30B on the substrate 22C, for example. can. Furthermore, since the three color light emitting layers and the semiconductor layer of the LED unit 44 are symmetrical with respect to the T direction, even if the LED unit 44 is installed upside down in the T direction on the substrate 22C, wiring etc. cannot be changed. Instead, the LED unit 44 can emit three colors of light with the same color tone.

Further, the image display device 20C of the present embodiment includes a substrate 22C to which the LED unit 44 and wirings 28A to 28I for supplying power to the light emitting layers 12R1, 12R2, etc. of the LED unit 44 are formed, and to which the LED unit 44 is bonded. , is equipped with. The image display device 20C can be efficiently manufactured because the LED units 44 can be efficiently arranged on the substrate 22C.

In addition, the method for manufacturing the LED unit 44 of the present embodiment includes forming the light emitting layers 12R1, 12R2, etc., the P layers 12PA, 12PB, etc., and the N layer 12NA, etc. so as to form three color LEDs 10R, 10B, and 10G, respectively. A step 102A of manufacturing red LED, blue LED, and green LED wafers 46R1, 46B1, 46G by arranging and bonding them in the T direction, and arranging the wafers 46R1, 46B1, 46G in the T direction and applying insulating adhesives 48A, 48B. The process includes a step 130 of bonding the bonded wafers 46R1, 46B1, and 46G together through a step 130, and a step 132 of cutting the bonded wafers 46R1, 46B1, and 46G in a direction orthogonal to the T direction. According to this manufacturing method, the multilayer three-color LED unit 44 can be manufactured efficiently and with high precision.

Further, the method for manufacturing the image display device 20C of this embodiment includes a step 138 of scattering a plurality of LED units 44 on the substrate 22C, and a step of joining the scattered LED units 44 and the substrate 22C by welding by heating. 118A. According to this manufacturing method, since the LED units 44 can be efficiently arranged in a targeted arrangement by scattering the LED units 44, the image display device 20C can be efficiently manufactured.

Note that the above-described embodiment can be modified as follows.
First, in the embodiment described above, the LED unit 44 emits light in three colors, but the LED unit 44 may emit light in at least one color. Further, the LED unit 44 may include a micro LED that generates white light.

In the above-described embodiment, as shown by the dotted line in FIG. 10(B), the suction hole 22Ca is formed in the area of the board 22C where the LED unit 44 is installed, and the LED unit 44 is connected to the terminal part of the board 22C. When fixing (welding), the LED unit 44 may be sucked through the suction hole 22Ca by a vacuum pump (not shown). This allows the LED unit 44 to be more stably fixed to the substrate 22C.
Further, in the above embodiments, the light emitting section is a light emitting diode, but the light emitting section may be a semiconductor laser or the like.

10R, 40R...Red LED, 10B, 40B...Blue LED, 10G, 40G...Green LED, 12P1, 12P2, 14P1, 14P2, 16P1, 16P2...P layer, 12N, 14N, 16N...N layer, 12R1, 12R2, 14B1 , 14B2, 16G1, 16G2... Light emitting layer, 20, 20A to 20C... Image display device, 22, 22A to 22C... Substrate, 26A to 26I... Terminal section, 28A to 28I... Wiring, 30, 30A, 30B... Guide member, 42, 42A, 42B, 44...LED unit, 46R1, 46R2...Red LED wafer, 46B1, 46B2...Blue LED wafer, 46G...Green LED wafer

Claims (40)

A light emitting layer having a plurality of first light emitting layers that emit light of a first color and a plurality of second light emitting layers that emit light of a second color different from the first color;
a plurality of semiconductor layers provided to sandwich each of the first light emitting layer and the second light emitting layer in a predetermined direction;
A light emitting element, wherein each of the plurality of first light emitting layers, the plurality of second light emitting layers, and the plurality of semiconductor layers are lined up and bonded in order so as to be line symmetrical with respect to a center line in the predetermined direction. The light emitting device according to claim 1,
In the light emitting element, the predetermined direction is a direction parallel to a surface of a flat substrate to which the light emitting element is bonded. The light emitting device according to claim 1 or 2,
The plurality of semiconductor layers are provided so as to sandwich the first light-emitting layer in the predetermined direction, and sandwich the second light-emitting layer between a first semiconductor layer and a second semiconductor layer having different conduction types in the predetermined direction. A light emitting element comprising a third semiconductor layer and a fourth semiconductor layer having different conduction types. The light emitting device according to claim 3,
The first semiconductor layer and the third semiconductor layer are P-type semiconductor layers,
A light emitting device, wherein the second semiconductor layer and the fourth semiconductor layer are N-type semiconductor layers. The light emitting device according to claim 3 or 4,
The light emitting layer has a plurality of third light emitting layers that emit light of a third color different from the first color and the second color,
The plurality of semiconductor layers are provided to sandwich the third light emitting layer in the predetermined direction, and include a fifth semiconductor layer and a sixth semiconductor layer having different conduction types,
Each of the plurality of first light-emitting layers, the plurality of second light-emitting layers, the plurality of third light-emitting layers, and the plurality of semiconductor layers are lined up and bonded in order so as to be line symmetrical with respect to a center line in the predetermined direction. Also, a light emitting element. The light emitting device according to claim 5,
The light emitting element, wherein one of the first to third light emitting layers is a green light emitting layer that emits green light, and the green light emitting layer is arranged closest to a central position in the predetermined direction. The light emitting device according to any one of claims 1 to 6,
A display device comprising: a substrate on which wiring for supplying power to the light emitting layer is formed and to which the light emitting element is bonded. The display device according to claim 7,
A display device including a guide portion that guides the light emitting element to a predetermined position where the light emitting element and the wiring are connected. The display device according to claim 8,
In the display device, the guide portion is formed such that a side surface of the light emitting element contacts the substrate. A manufacturing method for manufacturing the light emitting device according to any one of claims 1 to 6, comprising:
arranging and bonding the light emitting layer and the plurality of semiconductor layers in the predetermined direction to form the light emitting element;
A method for manufacturing a light emitting device, including cutting the joined light emitting layer and a plurality of semiconductor layers in a direction intersecting the predetermined direction. The method for manufacturing a light emitting device according to claim 10,
The joining includes:
manufacturing a first substrate by laminating the first light emitting layer and the semiconductor layer corresponding to the first light emitting layer;
manufacturing a second substrate by laminating the second light emitting layer and the semiconductor layer corresponding to the second light emitting layer;
A method for manufacturing a light emitting element, comprising arranging the first substrate and the second substrate in the predetermined direction and bonding them together with an insulating adhesive. A manufacturing method for manufacturing the display device according to any one of claims 7 to 9, comprising:
scattering the plurality of light emitting elements on the substrate;
A method for manufacturing a display device, comprising: bonding the scattered light emitting element and the substrate. The method for manufacturing a display device according to claim 12,
arranging along the substrate a guide portion in which a plurality of openings capable of accommodating the light emitting element are formed at predetermined positions where the light emitting element and the wiring are connected;
The method for manufacturing a display device, wherein the scattering includes scattering the plurality of light emitting elements onto the guide part so that the light emitting elements are respectively accommodated in the plurality of openings of the guide part. The method for manufacturing a display device according to claim 13,
A method for manufacturing a display device, wherein the scattering includes fixing the light emitting element on the substrate via a suction hole of the substrate so that the light emitting element located at the predetermined position does not shift. The method for manufacturing a display device according to claim 13 or 14,
The guide portion includes a first guide portion that guides the light emitting device so that the bottom surface of the light emitting device comes into contact with the substrate, and a side surface of the light emitting device where the bottom surface and the substrate are in contact with each other by the first guide portion. a second guide part that is movable so as to come into contact with the substrate and has the opening formed therein;
The scattering includes guiding the light emitting element to the opening of the second guide part through the first guide part so that the bottom surface of the light emitting element contacts the substrate; A method of manufacturing a display device, the method comprising: moving the second guide part so that a side surface thereof comes into contact with the substrate. The method for manufacturing a display device according to any one of claims 13 to 15,
A method for manufacturing a display device, comprising removing the guide portion from the substrate after the light emitting element and the substrate are bonded. The method for manufacturing a display device according to any one of claims 12 to 16,
The method for manufacturing a display device, wherein the bonding includes bonding the light emitting element and the substrate by heat treatment. a light-emitting layer having a plurality of first light-emitting layers and a plurality of second light-emitting layers, each of which emits light of a different wavelength;
a plurality of semiconductor layers bonded to the light emitting layer so that the light is emitted in the light emitting layer when a voltage is applied;
The plurality of semiconductor layers are provided so as to sandwich the first light emitting layer in a predetermined direction, and include a first semiconductor layer and a second semiconductor layer having different conduction types,
The plurality of semiconductor layers are provided to sandwich the second light emitting layer in the predetermined direction, and include a third semiconductor layer and a fourth semiconductor layer having different conduction types,
The light emitting layer and the plurality of semiconductor layers include the first semiconductor layer, the first light emitting layer, the second semiconductor layer, the third semiconductor layer, the second light emitting layer, and the fourth semiconductor layer with respect to the predetermined direction. A light emitting element forming a light emitting section in which a semiconductor layer, the second light emitting layer, the third semiconductor layer, the second semiconductor layer, the first light emitting layer, and the first semiconductor layer are lined up and bonded in this order. The light emitting device according to claim 18, wherein the number of the plurality of semiconductor layers is greater than the number of the light emitting layers. The light emitting device according to claim 19, wherein the number of the plurality of semiconductor layers is one more than the number of the light emitting layers. The light emitting device according to any one of claims 18 to 20,
The light emitting section includes, with respect to the predetermined direction, the first semiconductor layer, the first light emitting layer, the second semiconductor layer, the third semiconductor layer, the second light emitting layer, the fourth semiconductor layer, and the fourth semiconductor. The plurality of semiconductor layers and the light emitting layer are bonded side by side in the following order: layer, the second light emitting layer, the third semiconductor layer, the second semiconductor layer, the first light emitting layer, and the first semiconductor layer. , light emitting element. The light emitting device according to any one of claims 18 to 21,
The light emitting layer has a plurality of third light emitting layers that emit light of a different wavelength from the first and second light emitting layers,
The plurality of first light-emitting layers, the plurality of second light-emitting layers, and the plurality of third light-emitting layers are each arranged in line symmetry with respect to a center line in the predetermined direction. The light emitting device according to any one of claims 18 to 22,
The light emitting element is such that the light emitting section has a different size depending on the color of the light emitted in the corresponding light emitting layer. The light emitting device according to any one of claims 18 to 23,
At least one of the first and second light emitting layers is a light emitting element, wherein at least one of the first and second light emitting layers is a cylinder or a polygonal pillar having a circular or polygonal bottom surface and a height in the predetermined direction. The light emitting device according to claim 24,
A light emitting element, wherein at least one of the first or second light emitting layer has at least one of the bottom surface and the height different depending on the wavelength of light emitted in the corresponding light emitting layer. The light emitting device according to any one of claims 18 to 25,
The second light emitting layer is a light emitting device, wherein the second light emitting layer has a green light emitting layer that emits light of a green wavelength, and the green light emitting layer is arranged at the center with respect to the predetermined direction. The light emitting device according to any one of claims 18 to 26,
A display device comprising: a substrate on which wiring for supplying power to the light emitting layer is formed and to which the light emitting element is bonded. The display device according to claim 27,
A display device including a guide portion that guides the light emitting element to a predetermined position where the light emitting element and the wiring are connected. The display device according to claim 28,
In the display device, the guide portion is formed such that a side surface of the light emitting element contacts the substrate. The display device according to claim 28,
In the display device, the guide portion is formed such that a bottom surface of the light emitting element contacts the substrate. A manufacturing method for manufacturing the light emitting device according to any one of claims 18 to 26, comprising:
arranging and bonding the light emitting layer and the plurality of semiconductor layers in the predetermined direction to form the light emitting element;
A method for manufacturing a light emitting device, including cutting the joined light emitting layer and a plurality of semiconductor layers in a direction intersecting the predetermined direction. The method for manufacturing a light emitting device according to claim 31,
The light emitting layer has a first light emitting layer, a second light emitting layer, and a third light emitting layer that emit light of different wavelengths,
The semiconductor layer has a plurality of layers bonded to the first light emitting layer, the second light emitting layer, and the third light emitting layer, respectively,
The joining includes:
A first light emitting section, a second light emitting section, and a third light emitting section are formed by bonding the first light emitting layer, the second light emitting layer, and the third light emitting layer with the corresponding semiconductor layer. manufacturing a first substrate, a second substrate, and a third substrate;
A method for manufacturing a light emitting device, comprising arranging the first substrate, the second substrate, and the third substrate in the predetermined direction and bonding them together with an insulating adhesive. A manufacturing method for manufacturing the display device according to any one of claims 27 to 30, comprising:
scattering the plurality of light emitting elements on the substrate;
A method for manufacturing a display device, comprising: bonding the scattered light emitting element and the substrate. The method for manufacturing a display device according to claim 33,
The method for manufacturing a display device, wherein the scattering includes scattering a plurality of the light emitting elements having different sizes onto the substrate. The method for manufacturing a display device according to claim 33 or 34,
arranging along the substrate a guide portion in which a plurality of openings capable of accommodating the light emitting element are formed at predetermined positions where the light emitting element and the wiring are connected;
The method for manufacturing a display device, wherein the scattering includes scattering the plurality of light emitting elements onto the guide part so that the light emitting elements are respectively accommodated in the plurality of openings of the guide part. The method for manufacturing a display device according to claim 35,
A method for manufacturing a display device, wherein the scattering includes fixing the light emitting element on the substrate via a suction hole of the substrate so that the light emitting element located at the predetermined position does not shift. The method for manufacturing a display device according to claim 35 or 36,
The guide portion includes a first guide portion that guides the light emitting device so that the bottom surface of the light emitting device comes into contact with the substrate, and a side surface of the light emitting device where the bottom surface and the substrate are in contact with each other by the first guide portion. a second guide part that is movable so as to come into contact with the substrate and has the opening formed therein;
The scattering includes guiding the light emitting element to the opening of the second guide part through the first guide part so that the bottom surface of the light emitting element contacts the substrate; A method of manufacturing a display device, the method comprising: moving the second guide part so that a side surface thereof comes into contact with the substrate. The method for manufacturing a display device according to any one of claims 35 to 37,
A method for manufacturing a display device, comprising removing the guide portion from the substrate after the light emitting element and the substrate are bonded. The method for manufacturing a display device according to any one of claims 33 to 38,
The method for manufacturing a display device, wherein the bonding includes bonding the light emitting element and the substrate by heat treatment. The method for manufacturing a display device according to any one of claims 33 to 39,
The method for manufacturing a display device, wherein the scattering includes scattering the light emitting element whose charge has been removed by an ionizer onto the substrate.

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