WO2019102955A1 - Light-emitting element and display device, and method for manufacturing same - Google Patents

Abstract

A red-light-emitting diode comprising: a plurality of light-emitting layers, each of which emits red light; and a plurality of P and N layers joined to the light-emitting layers so that the light-emitting layers emit red light when a voltage is applied. The plurality of light-emitting layers and the plurality of P and N layers are sequentially lined up in direction T and joined. When manufacturing an image display device using the red-light-emitting diodes, the red-light-emitting diodes are scattered on the upper surface of a guide member placed on the upper surface of a substrate. The invention makes it possible to efficiently arrange light-emitting elements and manufacture an image display device.

Description

Light emitting element and display device, and method of manufacturing the same

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

An image display apparatus using a light emitting diode (LED) is assembled by arranging a so-called micro light emitting diode (hereinafter referred to as micro LED), which is a large number of small light emitting diodes, in a matrix. Conventionally, since red, blue, and green light emitting diodes are different from each other in the base material and the material to be deposited thereon, these three color light emitting diodes are manufactured using the semiconductor element manufacturing process on the same base material It is difficult to form. For this reason, when manufacturing a full color image display device, after manufacturing many micro LED of those three colors separately, it was necessary to arrange those micro LEDs separately in a predetermined arrangement. For example, cited document 1 is proposed as an example of the arrangement method.

JP 2002-368282

According to a first aspect, a plurality of light emitting layers each emitting light, and a plurality of semiconductor layers joined to the plurality of light emitting layers such that the light is emitted by the plurality of light emitting layers when voltage is applied, A light emitting device is provided, in which a plurality of light emitting layers and a plurality of semiconductor layers are joined in order in a predetermined direction.

According to a second aspect, there is provided a display device comprising the light emitting element of the first aspect and a substrate on which a wiring for supplying power to the light emitting layer is formed and the light emitting element is joined.

According to a third aspect, there is provided a method of manufacturing a light emitting device according to the first aspect, wherein a plurality of light emitting layers and a plurality of semiconductor layers are aligned and joined in a predetermined direction to form the light emitting device. There is provided a method of manufacturing a light emitting device, comprising: cutting the bonded light emitting device in a direction intersecting with the predetermined direction.

According to a fourth aspect, there is provided a manufacturing method of manufacturing the display device of the second aspect, wherein scattering of a plurality of light emitting elements, bonding of the scattered light emitting elements and the substrate are performed on the substrate. And providing a method of manufacturing a display device.

(A) is an enlarged perspective view showing a three-color micro LED according to the first embodiment, (B) is a view showing a red micro LED in FIG. 1 (A) and a modification thereof, and (C) is a view It is an expanded sectional view which shows the state which arrange | positioned the red micro LED of 1 (A) on the board | substrate. (A) is a front view which shows the image display apparatus which concerns on the embodiment, (B) is an enlarged view which shows a part of image display apparatus of FIG. 2 (A). It is a flowchart which shows an example of the manufacturing method of the image display apparatus which concerns on the embodiment. (A) is a perspective view which shows the state which arrange | positioned the guide member above the board | substrate, (B) is a perspective view which shows the state which installed the guide member on the upper surface of the board | substrate. (A) is a perspective view which shows the state which disperse | distributes many micro LED on the upper surface of a guide member, (B) is a perspective view which shows the state which arrange | positioned many micro LED on the upper surface of a board | substrate. (A) is a perspective view showing a state in which the guide member is removed from the substrate, (B) is an enlarged perspective view showing the three-color micro LED of the modification, (C) is an enlarged perspective view showing the micro LED of another modification FIG. (A) is an enlarged view showing a part of an image display apparatus according to still another modification, (B) is a cross-sectional view of FIG. 7 (A), and (C) is another corresponding to FIG. 7 (B) (D) is a cross-sectional view corresponding to FIG. 7 (B) of the example using the micro LED of FIG. 6 (B) which shows a modification. (A), (B), (C), and (D) are side views showing the first, second, third, and fourth micro LED units according to the second embodiment, respectively. (A) is a front view which shows the image display apparatus which uses a 1st micro LED unit, (B) is a front view which shows an image display apparatus which uses a 2nd micro LED unit. (A) is a front view which shows the image display apparatus which uses a 4th micro LED unit, (B) is an expanded sectional view of a part of FIG. 10 (A). It is a flowchart which shows an example of the manufacturing method of the image display apparatus which concerns on 2nd Embodiment. (A) is an enlarged side view showing wafers for five light emitting diodes, (B) is an enlarged side view showing a state in which five wafers are bonded. (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 the micro LED unit is cut out. (A) is a perspective view which shows the state which arrange | positioned the 1st guide member above the board | substrate, (B) is a perspective view which shows the state which disperse | distributes many micro LED units on the upper surface of a 1st guide member. (A) is a perspective view showing a state in which the micro LED unit is disposed 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 of FIG. Fig. 15 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 the second guide member is disposed above the first guide member and the plurality of micro LED units are dispersed above the first guide member; (B) is a plurality of micro LED units It is an expanded cross-sectional view which shows the state which edge part settled in opening of the 1st guide member. (A) is an enlarged cross-sectional view showing relative movement of the second guide member in the X direction with respect to the first guide member, and (B) is an arrangement of a plurality of micro LED units in the opening of the first guide member FIG. 6 is an enlarged cross-sectional view showing the state of FIG.

The first embodiment will be described below with reference to FIGS. 1 (A) to 6 (A). Hereinafter, the light emitting diode is also simply referred to as an LED.
FIG. 1A generates a light emitting diode (hereinafter referred to as a red LED) 10R that generates red light, a light emitting diode (hereinafter referred to as a blue LED) 10B that generates blue light, and green light according to the present embodiment. A light emitting diode (hereinafter referred to as a green LED) 10G is shown. Each of the LEDs 10R, 10B, and 10G has a rectangular cross-sectional shape and a rectangular parallelepiped shape having a height (length) higher than the length of the side of the cross section. As an example, in the shape of the LED 10R, 10B, 10G, the side length of the cross section is about 20 to 100 μm, and the height is about 1.5 times to 3 times the side length. That is, the LEDs 10R, 10B, and 10G are each a micro LED. 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 than the red LED 10R and a higher height than the red LED 10R, and the green LED 10G has the smallest cross-sectional area and the highest height high. In addition, LED10R, 10B, 10G should just differ in a shape mutually, The shape is arbitrary. Below, the direction of height (length) of LED10R, 10B, 10G is demonstrated as T direction.

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, an N-type semiconductor layer It is formed by laminating 12 N (second semiconductor layer) (hereinafter referred to as N layer), second light emitting layer 12 R 2, and second P layer 12 P 2 (first semiconductor layer). The P layers 12P1 and 12P2 and the N layer 12N have different conduction types. The light emitting layers 12R1 and 12R2 can also be regarded as part of the semiconductor layer. Moreover, lamination can also be said to be bonding of multiple times. In the present 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) includes, in order from the P layer 12P1 (12P2) to the N layer 12N, a so-called p-layer having a hole density lower than that of the P layer 12P1 (12P2) and an N layer 12N. It is a laminate of so-called n-layers with low electron density. Similarly, in the blue LED 10B (blue micro LED), the first P layer 14P1, the first light emitting layer 14B1, the N layer 14N, the second light emitting layer 14B2, and the second P layer 14P2 are sequentially arranged in the T direction. The green LED 10G (green micro LED) is formed by stacking the first P layer 16P1, the first light emitting layer 16G1, the N layer 16N, the second light emitting layer 16G2, and the second light emitting layer 16G. P layer 16P2 is laminated and formed.

As an example, the red LED 10R is made of gallium phosphor (GaP (Zn, O)) or gallium aluminum arsenide (GaAlAs) in which zinc, oxygen, etc. are added to the surface of a substrate made of gallium phosphor (GaP) or gallium arsenide (GaAs). And the semiconductor layer (P layer, N layer) and the light emitting layer are formed, and the blue LED 10B is a semiconductor layer such as indium gallium nitrogen (InGaN) on the surface of the base made of sapphire or silicon carbide (SiC) And the light emitting layer are formed, and the green LED 10G is formed on the surface of the base material made of sapphire or SiC by forming the semiconductor layer and the light emitting layer such as gallium phosphorus (GaP (N)) or InGaN to which nitrogen or the like is added. Manufactured. Thus, the materials of the base, the semiconductor layer, and the light emitting layer of the LED 10R and the LEDs 10B and 10G are different from each other. Moreover, LED10B and 10G may mutually differ in the material of a base material, a semiconductor layer, and at least one of a light emitting layer mutually. The materials of the base material and the semiconductor layer of the LED 10R, 10B and 10G and the light emitting layer are arbitrary, and the materials of the base material and / or the semiconductor layer of the LED 10R, 10B and 10G and the light emitting layer may be the same.

As shown in FIG. 1B, in the red LED 10R, the P layers 12P1 and 12P2 and the N layer 12N are respectively symmetrical (linearly symmetrical) with respect to a straight line 18 centered in the T direction. In the following, being symmetrical about a straight line 18 centered in the T direction is also referred to simply as being symmetrical about the T direction. In order to manufacture an image display device using the red LED 10R (described in detail later), as shown in FIG. 2C, the red LED 10R is placed in the guide member 30 on the substrate 22 to set the wires 28A and 28B. When a positive voltage is applied to the P layers 12P1 and 12P2 and a negative voltage is applied to the N layer 12N through the wiring 28B (or grounded), all directions from the light emitting layers 12R1 and 12R2 of the red LED 10R ( Red light is generated in the lateral 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 simultaneously emit light, the light intensity is doubled as compared with one light emitting diode. Further, by making the voltages applied to the P layers 12P1 and 12P2 different, 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, since the P layers 12P1 and 12P2 and the N layer 12N are symmetrical with respect to the T direction in the red LED 10R, even if the red LED 10R is installed on the substrate 22 with the red LED 10R inverted with respect to the T direction The red LED 10R emits light in the same manner as before reversing the direction without changing the voltage and without changing the voltage applied to the wirings 28A to 28C. The same applies to the other LEDs 10B and 10G. Therefore, the LEDs 10R, 10B, and 10G can be arranged efficiently on the substrate 22.

In the red LED 10R, the light emitting layers 12R1 and 12R2 are also symmetrical with respect to the T direction. Therefore, the color tone does not change even if the red LED 10R is installed in the T direction in a reversed manner.
Also, instead of the red LED 10R, as shown in FIG. 1B, the first N layer 12N1, the first light emitting layer 12R1, the P layer 12P, the second light emitting layer 12R2, and the first light emitting layer 12R1 are sequentially arranged in the T direction. It is also possible to manufacture (use) a red LED 10RA formed by bonding two N layers 12N2. 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 interchanged. Also in the red LED 10RA, the N layers 12N1 and 12N2, the light emitting layers 12R1 and 12R2, and the P layer 12P are symmetrical with respect to the T direction. Therefore, even if the red LED 10RA is installed on the substrate 22 so as to be inverted with respect to the T direction, the red LED 10RA emits light as before the direction is inverted.

Next, FIG. 2A shows a full-color image display device 20 using the LEDs 10R, 10B, and 10G (micro LEDs of three colors) according to the present embodiment. The image display device 20 includes a display unit in which red LEDs 10R, blue LEDs 10B, and green LEDs 10G are arranged in a matrix and fixed 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. And a controller 24 for individually controlling the light intensity and the light intensity. In FIG. 2A and the drawings referred to below, the LEDs 10R, 10B, and 10G are shown in a considerably enlarged size than the actual size for the convenience of description. Hereinafter, the description will be made by taking the X axis and the Y axis along the longitudinal direction and the short direction of the substrate 22, respectively. In the present embodiment, as an example, the T direction, which is the bonding direction of the LEDs 10R, 10B, and 10G, is the direction (X direction) parallel to the X axis. In the present embodiment, the red LEDs 10R, the blue LEDs 10B, and the green LEDs 10G are arranged at a predetermined pitch in the Y direction along straight lines 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 It is 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 arrangement number of the LEDs 10R, 10B and 10G in the X direction and Y direction is about 1000, respectively. The arrangement of the LEDs 10R, 10B and 10G is arbitrary, and the LEDs 10R, 10B and 10G may be arranged in a checkered pattern, for example.

Further, as shown in FIG. 2B, P layers 12P1, 12P2, 14P1, 14P2 and 16P1, 16P2 of the LEDs 10R, 10B, 10G are provided in the regions of the upper surface of the substrate 22 where the LEDs 10R, 10B, 10G are installed. Wiring 28A, 28C, 28D, 28F, 28G, 28I for applying a voltage to FIG. 1 (A), and wiring 28B for applying a voltage to N layers 12N, 14N and 16N of LEDs 10R, 10B, 10G. , 28E, 28H are formed. Further, thin disk- like terminal portions 26A, 26B, 26C, 26D, 26E, 26F, 26G, 26H, 26I are provided at the contact portions of the wires 28A to 28I with the corresponding P layer 12P1 or the like or the N layer 12N or the like. It is formed. The terminal portions 26A to 26I are formed of a material (for example, solder or the like) that can be welded to the corresponding P layer or N layer by heating. The wires 28A to 28I may also be formed of 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 multiple LEDs 10R, 10B, and 10G and for each of two light emitting layers in each of the LEDs 10R, 10B, and 10G. As a result, it is possible to display an arbitrary image in full color and high definition on the display unit. The terminal portions 26A to 26I (and the wires 28A to 28I) may be formed of a conductive adhesive.

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

First, in step 102 of FIG. 3, the P layer, the light emitting layer, and the like are respectively formed on the surfaces of three types of disk-like base materials (not shown) for manufacturing the LEDs 10R, 10B and 10G using a semiconductor device manufacturing process. The N layer, the light emitting layer, and the P layer are stacked to produce three types of wafers. Then, in step 104, the substrate 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 respective colors by a dicing apparatus. As a result, a large number of red LEDs 10R, blue LEDs 10B, and green LEDs 10G are manufactured.

Further, in step 106, as shown in FIG. 4A, the substrate 22 and the guide member 30 of the image display device 20 are manufactured. In the regions 23R, 23B and 23G where the LEDs 10R, 10B and 10G are arranged on the upper surface of the substrate 22 (for example, the positions are defined in advance with respect to the ends of the substrate 22 in the X direction and Y direction) To 28I and terminal portions 26A to 26I (see FIG. 2B) are formed. Furthermore, the control unit 24 is also manufactured. The guide member 30 has substantially the same size as the substrate 22, and the guide member 30 has the same arrangement as the arrangement of the LEDs 10R, 10B, and 10G of FIG. Rectangular openings 32B that can accommodate the LEDs 10B and rectangular openings 32G that can accommodate the green LEDs 10G are formed in a matrix. The openings 32R, 32B, 32G are formed slightly larger than the shapes of the side surfaces of the corresponding LEDs 10R, 10B, 10G. In the present embodiment, since the LEDs 10R, 10B, and 10G are gradually elongated in shape, when the LEDs 10R, 10B, and 10G are disposed such that the side surfaces are in contact with the substrate 22, the openings 32R, 32B, and 32G are red LEDs 10R, respectively. Only the blue LED 10B and the green LED 10G can be accommodated.

When using the guide members 30 only when arranging the LEDs 10R, 10B and 10G on the substrate 22 and removing the guide members 30 after the arrangement is completed, the guide members 30 are formed of metal (aluminum etc.) or ceramics etc. It is also good. On the other hand, when the guide member 30 is attached to the substrate 22, the guide member 30 may be formed of synthetic resin or the like. The thickness of the guide member 30 around the openings 32R, 32B, 32G is about the side length of the cross section of the green LED 10G having the smallest cross sectional area.

Then, in step 108, the guide member 30 with respect to the substrate 22 such that the openings 32R, 32B and 32G of the guide member 30 face the regions 23R, 23B and 23G in which the LEDs 10R, 10B and 10G of the substrate 22 are disposed. And the guide member 30 is disposed on the upper surface of the substrate 22 as shown in FIG. 4 (B). At this time, the longitudinal directions of the openings 32R, 32B, 32G of the guide member 30 are parallel to the X direction. When the guide member 30 is removed from the substrate 22 after the arrangement of the LEDs 10R, 10B, 10G, the guide member 30 may be held slightly spaced from the substrate 22 by, for example, a support member (not shown). When the guide member 30 is attached to the substrate 22, the guide member 30 may be fixed to the substrate 22 by adhesion or the like. The steps of manufacturing the LEDs 10R and the like in steps 102 and 104 and the steps of manufacturing the substrates and the like in steps 106 and 108 may be performed substantially in parallel.

In the next step 112, as shown in FIG. 5A, a method of inclining a stocker accommodating a large number of LEDs 10R, 10B, 10G (not shown) on the upper surface of the guide member 30 disposed on the substrate 22 , Scatter a number of LEDs 10R, 10B, 10G. As a result, as shown in FIG. 5B, the red LED 10R, the blue LED 10B, and the green LED 10G are accommodated in the openings 32R, 32B, and 32G of the guide member 30 such that the side surfaces thereof are in contact with the substrate 22. In the next step 114, the LEDs 10R, 10B and 10G which are on the upper surface of the guide member 30 and are not accommodated in the openings 32R, 32B and 32G are removed. This step 114 may be performed after the LEDs 10R, 10B, and 10G are fixed to the substrate 22 as described later. Then, in step 116, it is checked whether the LEDs 10R, 10B and 10G corresponding to all the openings 32R, 32B and 32G of the guide member 30 are accommodated using an inspection device (not shown). Then, if there are openings 32R, 32B, 32G in which the LEDs 10R, 10B, 10G are not accommodated, the steps 112, 114 are repeated until the LEDs 10R, 10B, 10G are accommodated in all the openings 32R, 32B, 32G. .

And when LED10R, 10B, 10G is accommodated in all the opening 32R, 32B, 32G, it transfers to step 118 and heats the board | substrate 22 from a bottom face. At this time, the upper portions of the LEDs 10R, 10B, and 10G may be biased toward the substrate 22 side using a member having flexibility (not shown). By this, the terminal portions 26A to 26I (and the wirings 28A to 28I) of the substrate 22 shown in FIG. 2B are welded to the P layer or N layer of the corresponding LED 10R, 10B, 10G, and the LEDs 10R, 10B, 10G are respectively The P layer and the N layer are fixed to the upper surface of the substrate 22 in a state where they are electrically conducted to the corresponding wires 28A to 28I and the like. Thereafter, in step 120, it is determined whether or not the guide member 30 is to be removed. If the guide member 30 is to be removed, the process proceeds to step 122, and as shown in FIG. Remove Thereafter, in step 124, the image display device 20 is manufactured by installing a cover glass that covers the LEDs 10R, 10B, and 10G. If the guide member 30 is not removed, the operation moves from step 120 to step 124. When the terminal portions 26A to 26I (and the wires 28A to 28I) are formed of a conductive adhesive, the heating process of the substrate 22 in step 118 can be omitted.

As described above, in the present embodiment, by scattering a large number of LEDs 10R, 10B, and 10G on the upper surface of the guide member 30, the three types of LEDs 10R, 10B, and 10G are efficiently arranged in the target arrangement on the upper surface of the substrate 22. it can. At this time, the LEDs 10R, 10B, 10G are symmetrical with respect to the openings 32R, 32B, 32G of the guide member 30 because the P layers 12P1, 12P2, etc. and the N layer 12N etc. (semiconductor layers) are symmetrical in the T direction. , And 10 G are accommodated in an inverted manner with respect to the T direction (X direction), the LEDs 10 R, 10 B, and 10 G can emit light in the same manner without changing the voltage applied to the wirings 28 A to 28 I. Therefore, the image display device 20 can be manufactured more efficiently.

As described above, in the red LED 10R (micro LED) of the present embodiment, the red light is emitted in the plurality of light emitting layers 12R1 and 12R2 that respectively emit red light and the light emitting layers 12R1 and 12R2 when voltage is applied. A plurality of P layers 12P1 and 12P2 (first semiconductor layer) and an N layer 12N (second semiconductor layer) joined to the light emitting layers 12R1 and 12R2, and a plurality of light emitting layers 12R1 and 12R2 and a plurality of P layers This is a light emitting element in which 12P1 and 12P2 and an N layer 12N (semiconductor layer) are joined in order in the T direction (junction direction). 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 openings of the guide member 30 only by scattering the LEDs 10R, 10B and 10G on the upper surface of the guide member 30 on the substrate 22, for example. By being accommodated in 32R, 32B and 32G, the LEDs 10R, 10B and 10G can be efficiently arranged in a targeted arrangement. Note that, for example, when the P layers 12P1 and 12P2 and the N layer 12N (semiconductor layer) of the red LED 10R are not symmetrical with respect to the T direction, for example, after the red LED 10R is installed on the substrate 22, the red LED 10R is The direction in which the current flows (the arrangement state of the P layers 12P1 and 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 according to the present embodiment, the LEDs 10R, 10B, and 10G and the wirings 28A to 28I for supplying power to the light emitting layers 12R1, 12R2, 14B1, 14B2, 16G1 and 16G2 are formed, and the LEDs 10R and 10B are formed. , And 10G are bonded to each other. The image display device 20 can efficiently manufacture the LEDs 10R, 10B, and 10G on the substrate 22 with high accuracy and efficiency.

In addition, in the method of manufacturing the red LED 10R of the present embodiment, the light emitting layers 12R1 and 12R2, the P layers 12P1 and 12P2 and the N layer 12N are aligned in the T direction and bonded to form a red LED 10R. Step 102; and separating 104 the wafer including the bonded red LED 10R in the direction orthogonal to the T direction. According to this manufacturing method, it is possible to efficiently manufacture the red LED 10R having the plurality of light emitting layers 12R1 and 12R2.

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

In the above embodiment, the following modifications are possible.
First, in the above embodiment, when the LEDs 10R, 10B, and 10G are scattered on the upper surface of the guide member 30 (substrate 22), the LEDs 10R, 10B, and 10G may be removed by an ionizer (not shown). This can prevent the LEDs 10R, 10B, 10G from adhering to the area other than the openings 32R, 32B, 32G of the guide member 30.

In the above-described embodiment, the light emitting layers 12R1 and 12R2 of the LEDs 10R, 10B and 10G are two layers, and the semiconductor layers of the P layers 12P1 and 12P2 and the N layer 12N are three layers. You may In the case where the light emitting layer is formed of three or more N layers (N is an integer of 3 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). When the number of light emitting layers 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.

Moreover, although LED10R, 10B, 10G is rectangular solid shape, as shown to FIG. 6 (B), cylindrical red LED11R, blue LED11B, and green LED11G can also be manufactured. For example, the red LED 11R is formed by sequentially laminating the P layer 13P1, the light emitting layer 13R1, the N layer 13N, the light emitting layer 13R2, and the P layer 13P2 in the T direction. Also in the LEDs 11R, 11B, and 11G, since the semiconductor layers are symmetrical in the T direction, the same effect as that of the above-described 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. As described above, the LEDs 11R, 11B, and 11G have different shapes from each other, and therefore, when arranging the LEDs 11R, 11B, and 11G on the substrate 22, they have openings that can accommodate the LEDs 11R, 11B, and 11G similar to the guide member 30. By using the guide members, the LEDs 11R, 11B and 11G can be efficiently arranged in a targeted arrangement. Furthermore, as shown to FIG. 6C, it is also possible to manufacture prismatic red LED 11RA whose cross-sectional shape is a regular hexagon. It is also possible to produce micro-LEDs of arbitrary cross-sectional shape.

Further, in the above-described embodiment, 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. 7A corresponding to FIG. 2B, the LED 10R, 10B, 10G can be installed in the region where the LED 10R, 10B, 10G is installed on the upper surface of the substrate 22 Recesses 22a, 22b and 22c may be formed. FIG. 7B is a cross-sectional view of FIG. 7A, and as shown in FIG. 7B, in the recesses 22a, 22b and 22c, the P layer and the N layer of the LEDs 10R, 10B and 10G are respectively provided. Terminal portions 26A to 26I are formed at opposing positions, and the terminal portions 26A to 26I are connected to the control unit 24 of FIG. 2A via the 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 can be accommodated. Each of the LEDs 10R, 10B and 10G is accommodated. Therefore, without using the guide member 30, the LEDs 10R, 10B, and 10G can be efficiently arranged on the upper surface of the substrate 22 in a targeted arrangement.

In this modification, the LEDs 10R, 10B, and 10G are disposed in the recessed portions 22a, 22b, and 22c such that the side surfaces thereof are in contact with the substrate 22, respectively. For this reason, an image can be displayed by the light of sufficient light intensity emitted from the side surfaces of the LEDs 10R, 10B, and 10G. Further, as shown in FIG. 7C, recesses 22d, 22e, 22f are provided on the upper surface of the substrate 22 so that the longitudinal direction (T direction) of the LEDs 10R, 10B, 10G is perpendicular to the upper surface. It is also possible. In FIG. 7C, although the LEDs 10R, 10B, and 10G are illustrated as being accommodated so as to project from the upper surface of the substrate 22, they are recessed according to the length in the longitudinal direction of the LEDs 10R, 10B, and 10G. The length (depth) in the Z direction of 22 d, 22 e, 22 f may be set. Moreover, when setting the length (depth) of the Z direction of recessed part 22d, 22e, 22f, it is not necessary to set so that all the light emitting layers of LED10R, 10B, 10G may emit light, LED10R, 10B, The number of light emitting layers in contact with the substrate among the 10 G light emitting layers may be the same for the LEDs 10R, 10B, and 10G. When the radial length of the LED 10R, 10B, 10G is shorter than the radial length of the recess 22d, 22e, 22f, for example, the LED 10G is inserted into the LED 10G and the recess 22d, and the recess 22d which should not be accommodated. Sometimes. However, in this case, since the length in the radial direction is largely different, the possibility that the LED 10G in the recess 22d contacts the substrate 22 is low, and the LED 10G does not emit light. Even if the LED 10G is inserted into the recess 22d, the LED 10G drops out of the recess 22d because the length in the radial direction is largely different. Therefore, even if LEDs (e.g., 10G) having different radial lengths are accommodated in the recesses (e.g., the recesses 22d) that should not be accommodated, there is almost no possibility that the LEDs emit light.

Further, as shown in FIG. 7D, in the case of using the cylindrical LEDs 11R, 11B, 11G of FIG. 6B, the side surface of the cylinder which can accommodate the LEDs 11R, 11B, 11G on the upper surface of the substrate 22 respectively. The concave portions 22h, 22i and 22g may be formed in advance. In this example, when the LEDs 11R, 11B, and 11G are scattered, the LEDs 11R, 11B, and 11G are efficiently arranged in the concave portions 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). In FIGS. 8 (A) to 17 (B), the parts corresponding to FIGS. 1 (A) to 6 (A) are assigned the same reference numerals and detailed explanations 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 according to the present embodiment are combined. The LED unit 42 includes a first light emitting diode (hereinafter referred to as a red LED) 40R (first light emitting portion) that generates red light, and a first light emitting diode (hereinafter referred to as a blue LED) 2) a first light emitting diode (hereinafter referred to as a green LED) 40G (third light emitting unit) that generates green light, a second green LED 40G1 (a third light emitting unit), and a second blue LED 40B1 (a second light emitting unit) The light emitting portion) and the second red LED 40R1 (first light emitting portion) are joined in a T direction which is a joining direction of the light emitting layer and the semiconductor layer of each LED. The red LED 40R is formed by sequentially laminating the P layer 12P1 (first layer), the light emitting layer 12R1, and the N layer 12N (second layer) in the T direction, and the blue LED 40B sequentially forms the P layer 14P1 in the T direction. The green LED 40G is formed by stacking the third layer, the light emitting layer 14B1, and the N layer 14N (fourth layer) in the T direction, the P layer 16P1 (fifth layer), the light emitting layer 16G1, and the N layer 14N. It is formed by laminating the layer 16N (sixth layer).

In addition, 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 in the T direction, respectively. In the LED unit 42, the green LEDs 40G and 40G1 (third light emitting unit) are configured such that the N layer 16N (second semiconductor layer) is interposed 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 the 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 rectangular cross-sectional shape and a rectangular parallelepiped shape elongated in the T direction. In the LED unit 42, P layers 12P1, 14P1, 16P1, 16P1, 14P1, 12P1 and N layers 12N, 14N, 16N, 16N, 14N, 12N are respectively symmetrical (linearly symmetrical with respect to a straight line 18A centered in the T direction. ). In this case, when the LED unit 42 is installed on the substrate 22A (see FIG. 9A) in order to manufacture the image display device using the LED unit 42, the LED unit 42 is reversed in the T direction on the substrate 22. Even when installed, the LED unit 42 emits light of three colors without changing the wiring pattern (not shown) and without changing the voltage applied to the wiring. Therefore, the LED units 42 can be efficiently arranged on the substrate 22.

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, the color tone does not change even if the LED unit 42 is installed in reverse in the T direction. Further, at the center of the LED unit 42, green LEDs 40G and 40G1 are arranged. Among red light, blue light and green light, green light (center is 555 nm) has the highest relative visibility, and by arranging the green LEDs 40 G and 40 G 1 at the center, the center becomes bright and the balance of brightness is good. However, the LED unit 42 can individually control the voltages supplied to the red LEDs 40R and 40R1, the blue LEDs 40B and 40B1, and the green LEDs 40G and 40G1, and the light intensities of the red LEDs 40R and 40R1 and the blue LEDs 40B and 40B1 and the green LEDs 40G and 40G1. It is not always necessary to center the green LEDs 40G and 40G1 because they can be controlled individually.

Next, FIG. 8B shows a second LED unit 42A. The LED unit 42A is formed 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 inverted in the T direction with respect to the first blue LED 10B and the first red LED 10R, respectively. In the red LED 10R and the blue LED 10B, as described in the first embodiment, the semiconductor layer and the light emitting layer 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, ... 12N are symmetrical with respect to a straight line 18B that is centered in the T direction. Further, in the LED unit 42A, the light emitting layers 12R1, 12R2, 14B1, 14B2, 16G1, 16G2, 14B2, 14B1, 12R2, 12R1 of the three colors are symmetrical with respect to the T direction. In this case, when manufacturing the image display device using the LED unit 42A, even if the LED unit 42A is installed inverted on the substrate with respect to the T direction, the wiring pattern is not shown and the wiring pattern is not changed. The LED unit 42A emits light of three colors without changing the voltage to be applied. Therefore, the LED units 42A can be efficiently arranged on the substrate. Furthermore, the color tone does not change.

Further, FIG. 8C shows a third LED unit 42B. The LED unit 42B is obtained 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. Also in the LED unit 42B, the P layers 12P1, 14P1, ... 14P1, 12P1 and the N layers 12N, 14N, ... 12N are symmetrical with respect to a straight line 18C that is centered in the T direction. Further, in the LED unit 42B, the light emitting layers 12R1, 14B1, 16G1, 16G2, 14B1 and 12R1 of the three colors are respectively symmetrical with respect to the T direction. In this case, when manufacturing the image display device using the LED unit 42B, even if the LED unit 42B is installed inverted on the substrate in the T direction, it is further added to the wiring without changing the wiring pattern (not shown). The LED unit 42B emits three colors of light without changing the voltage to be applied. Furthermore, the color tone does not change.

Further, FIG. 8D shows a fourth LED unit 44. The LED unit 44 includes a first red LED 10R, a spacer 46A, a first blue LED 10B, a spacer 46B, a green LED 10G, a spacer 46C, a second blue LED 10B, a spacer 46D, and a second red LED 10R. It is joined in the direction. The spacer portions 46A to 46D having the same configuration and the same size are, for example, the base materials or portions thereof used in manufacturing the LEDs 10R, 10B, and 10G, and the spacer portions 46A to 46D are portions that do not generate light Black portion or so-called black matrix portion). Further, in the second blue LED 10B and the second red LED 10R, the codes 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 portion) arranges the P layer 12P1 (third layer), the light emitting layer 14B1, the N layer 14N (fourth layer), the light emitting layer 14B2 and the P layer 14P2 (third layer) in order in the T direction. Configuration. In the blue LED 10B, the P layer 12P1 (third layer) and the light emitting layer 14B1 are arranged on one end side in the T direction, and the light emitting layer 14B2 and the P layer 14P2 (third layer) are arranged on the other end side. The LED unit 44 is, for example, a square having a width of about 20 to 100 μm and 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, ... 12N are symmetrical with respect to a straight line 18D centered in the T direction. Furthermore, in the LED unit 44, the three light emitting layers 12R1, 12R2, 14B1, 14B2, 16G1, 16G2, 14B1, 12R2, 12R1 and the spacer portions 46A to 46D are symmetrical with respect to the T direction. In this case, when manufacturing the image display device using the LED unit 44, even if the LED unit 44 is installed inverted on the substrate in the T direction, the wiring pattern is not shown and the wiring pattern is not changed. The LED unit 44 emits light of three colors without changing the applied voltage. Therefore, the LED units 44 can be efficiently arranged on the substrate. Furthermore, the color tone does not change.

As described above, each of the LED units 42, 42A, 42B, 44 has a rectangular cross-sectional shape and a rectangular parallelepiped shape elongated in the T direction. The outer shape of the LED units 42, 42A to 42C, 44 may be an elongated cylindrical shape or an elongated polygonal prism. In addition, if the semiconductor layers (P layer, N layer) and the light emitting layers of each color are symmetrically arranged in the T direction, the LED units 42, 42A to 42C, 44 have the semiconductor layers (P layer, N layer) and The number and arrangement of 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 the present embodiment. FIG. 9B shows a full-color image display device 20B using the LED unit 42B according to the present embodiment. FIG. 10A shows a full-color image display device 20C using the LED units 44 according to the present embodiment. The image display devices 20A, 20B, and 20C each have a display unit in which LED units 42, 42A, and 44 are arranged and fixed in a matrix on the upper surface of the substrates 22A, 22B, and 22C made of substantially rectangular insulators. The control units 24A, 24B, and 24C individually control the on / off and the light intensity of the LED units 42, 42A, and 44, respectively. 9 (A), 9 (B), 10 (A) and the drawings referred to below, the LED units 42, 42A, 44 are shown in a considerably enlarged size than the actual size for convenience of explanation. There is. Hereinafter, description will be made by taking the X axis and the Y axis along the longitudinal direction and the short direction of the substrates 22A, 22B, 22C, respectively. In the present embodiment, as an example, the T direction which is the bonding direction of the LED units 42, 42A, 44 is the X direction.

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

In this embodiment, the LED units 42, 42A, 44 are arranged at a predetermined pitch in the X direction along straight lines 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 checkerboard pattern with a half pitch offset 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, and the LED units 42, 42A, 44 The pitch of the arrangement in the Y direction is, for example, about 1.5 to 2 times the width of the cross-sectional shape of the LED units 42, 42A, 44. The number of arrangements of the LED units 42, 42A and 44 in the X and Y directions is about 200 and 1000, respectively. The arrangement and the number of arrangements of the 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 as they are translated in the Y direction. .

Further, as shown in FIG. 10B, the P layer 12P1 of the LEDs 10R, 10B, 10G, 10B, and 10R of the LED unit 44 is provided in the area where the LED unit 44 is installed on the upper surface of the substrate 22C of the image display device 20C. , 12P2,... 12P2 and N layers 12N, 14N,... 12N (see FIG. 8D), wirings 28A-28I and 28F-28A are formed for applying a voltage. In addition, between the wires 28A to 28I and the corresponding LEDs 10R, 10B, and 10G, a terminal portion made of a material or a conductive adhesive that can be welded by heating similar to the terminal portions 26A to 26I of FIG. Not shown). The control unit 24C individually controls voltages applied to the wires 28A to 28I and the like for each of the two light emitting layers in the LEDs 10R, 10B, and 10G in the multiple LED units 44. As a result, it is possible to display an arbitrary image in full color and 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 unit.

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

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

Then, in step 130, as shown in FIG. 12B, the five wafers 46R1, 46B1, 46G, 46B2, 46R2 are bonded together via the insulating adhesives 48A, 48B, 48C, 48D. Further, in step 132, as shown in FIG. 13A, the base 48A of the lowermost red LED wafer 46R1 is separated (removed) by etching or the like to form the aggregate 50 of the large number of LED units 44. It manufactures and the dotted line cutting part 52 of the assembly 50 is cut | disconnected with a dicing apparatus (not shown). As a result, as shown in FIG. 13B, a large number of LED units 44 can be manufactured in which the LEDs 10R, 10B, and 10G and the spacer portions 46A to 46D are stacked. Parts of the substrates 48B, 48C, 48B and 48A of the wafers 46B1, 46G, 46B2 and 46R2 are spacer portions 46A to 46D, respectively. According to the method of manufacturing the LED unit 44, the LED unit 44 having a multilayer structure can be manufactured efficiently.

Then, in step 106A, as shown in FIG. 14A, the substrate 22C of the image display device 20C, the first guide member 30A, and the second guide member 30B of FIG. 16A are manufactured. Wirings 28A to 28I and terminal portions (terminals (for example, the positions are defined in advance with respect to the end portions of substrate 22C in the X direction and Y direction, respectively) in which LED units 44 on the upper surface of substrate 22C are arranged FIG. 10 (B) is formed. Furthermore, the control unit 24C is also manufactured. The guide member 30A has substantially the same size as the substrate 22C, and the guide member 30A has a plurality of rectangular openings 52 which can be accommodated in the same arrangement as the arrangement of the LED units 44 of FIG. It is formed in a matrix. The openings 52 are formed slightly larger than the shape of the side surface of the corresponding LED unit 44.

In this embodiment, the guide member 30A is attached to the substrate 22 as an example. The guide member 30A may be removed from the substrate 22 after the LED unit 44 is attached. The thickness of the guide member 30A around the opening 52 is about the width of the side of the cross section of the LED unit 44. Further, between the two adjacent openings 52 of the guide member 30A, as shown in FIGS. 15 (B) and 15 (C), inclined portions 54A, 54B which become gradually lower in the X direction in the opening 52, Inclined portions 54C and 54D are formed at 52 gradually decreasing in the Y direction. The LED units 44 are smoothly accommodated in the openings 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 disposed, as shown in FIG. As shown in FIG. 5, the guide member 30A is disposed and fixed on the upper surface of the substrate 22C. As an example, in the case where the second guide member 30B described later is not used, as shown in FIG. 14B, as in the steps 112 to 116 of FIG. As shown in FIG. 15A, the LED units 44 are disposed on the upper surface of the substrate 22C in the multiple openings 52 of the guide member 30A such that the side surfaces thereof are in contact with the upper surface of the substrate 22C. As shown in FIGS. 15B and 15C, the LED units 44 at the positions B1 and B2 are smoothly accommodated in the corresponding openings 52 via the inclined portions 54A and 54B of the guide member 30A. Thereafter, the operation proceeds to step 118A of FIG.

Here, in order to accommodate the LED unit 44 more efficiently in the opening 52 of the guide member 30A, as shown in FIG. 16A, the case of using the second guide member 30B will be described. The second guide member 30B has a large number of openings through which the LED units 44 arranged in the same direction as the multiple openings 52 of the first guide member 30A and whose longitudinal direction is disposed in the normal direction of the upper surface of the substrate 22C. 56 are formed. In other words, the opening 56 is a shape slightly larger than the cross-sectional shape of the LED unit 44. In the region adjacent to the opening 56 on the upper surface of the second guide member 30B, inclined portions 58A and 58B that gradually decrease toward the opening 56 are formed, and the bottom surface of the second guide member 30B (facing the substrate 22C) Slopes 58C and 58D (may be chamfers) smaller than the slopes 58A and 58B are formed in the region adjacent to the opening 56).

At this time, in step 136, the end of the opening 56 of the second guide member 30B in the -X direction substantially 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 such 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 driving unit 60 (not shown) that moves the second guide member 30B in the X direction, the Y direction, and the normal direction of the substrate 22C is used.

In the next step 138, as shown in FIG. 16A, a large number of LED units 44 are dispersed on the top surface of the substrate 22C and the second guide member 30B disposed above the first guide member 30A. As a result, the multiple LED units 44 pass through the openings 56 through the inclined portions 58A and 58B of the second guide member 30B. As shown in FIG. 16B, the end of the LED unit 44 which has passed through the opening 56 comes into contact with the end of the opening 52 of the first guide member 30A in the −X direction. 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 the arrow B3. Then, the movement of the second guide member 30B causes the LED units 44 in the opening 52 of the first guide member 30A to rotate clockwise, respectively, as shown in FIG. As shown in B), the LED units 44 in the openings 52 of the first guide member 30A are accommodated in the openings 52 in such a manner that the side surfaces thereof contact the substrate 22C. As a result, a large number of LED units 44 on the top surface of the substrate 22C are arranged in a target arrangement.

In the next step 118A, by heating the substrate 22C from the bottom surface, the terminal portion (not shown) of the substrate 22C (and the wirings 28A to 28I in FIG. 10B) correspond to the corresponding LEDs 10R, 10B, 10G of the LED unit 44. The LED unit 44 is fixed to the top 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, etc., whereby the image display device 20C is manufactured.

As described above, in the present embodiment, the LEDs are arranged in a target arrangement in the opening 52 of the first guide member 30A on the upper surface of the substrate 22C by spraying the multiple LED units 44 on the upper surface of the second guide member 30B. The units 44 can be arranged efficiently. At this time, since the LED units 44 have symmetrical P layers 12P1, 12P2,... 12P1 and N layers 12N, 14N,. Even in the case of being inverted and accommodated in the X direction, the LEDs 10R, 10B, and 10G of the LED unit 44 can emit light in the same manner without changing the voltage applied to the wirings 28A to 28I. Therefore, the image display device 20 can be manufactured more efficiently.

Further, since the three 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 accommodated 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, when a voltage is applied to the LED unit 44 of the present embodiment, the plurality of light emitting layers 12R1, 12R2, 14B1, 14B2, 16G1, 16G2 that emit red light, blue light, or green light, respectively. A plurality of P layers 12P1 and 12P2 etc. and N layers 12N and 14N etc. (semiconductor layers) joined to the light emitting layers 12R1 to 16G2 so that light is emitted by the light emitting layers 12R1 to 16G2, and a plurality of light emitting layers This is a light emitting element in which 12R1 etc., and a plurality of P layers 12P1 etc. and N layers 12N etc. (semiconductor layers) are joined in order in the T direction (junction direction).

When the image display device 20C is manufactured using the LED unit 44, the LED units 44 are efficiently arranged in a target arrangement, for example, only by scattering the LED units 44 on the upper surface of the guide member 30A or 30B on the substrate 22C. it can. Furthermore, since the light emitting layers and the semiconductor layers of the three colors of the LED unit 44 are respectively symmetrical with respect to the T direction, the wiring etc. should be changed even if the LED unit 44 is installed in the T direction on the substrate 22C. Instead, the three color lights of the LED unit 44 can be emitted in the same color tone.

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

In the method of manufacturing the LED unit 44 according to this embodiment, the light emitting layers 12R1 and 12R2 and the like, the P layers 12PA and 12PB and the N layer 12NA and the like are formed to form the three- color LEDs 10R, 10B and 10G, respectively. Step 102A of manufacturing wafers 46R1, 46B1 and 46G of red LEDs, blue LEDs and green LEDs by arranging and bonding in the direction of T, and insulating adhesives 48A and 48B by arranging the wafers 46R1, 46B1 and 46G in the direction of T Step 130 of bonding is performed, and step 132 of dividing the bonded wafers 46R1, 46B1 and 46G in the direction orthogonal to the T direction is performed. According to this manufacturing method, the multi-layered three-color LED unit 44 can be efficiently manufactured with high accuracy.

In the method of manufacturing the image display device 20C according to the present embodiment, the step 138 of scattering the plurality of LED units 44 on the substrate 22C, and the step of bonding the scattered LED units 44 and the substrate 22C by welding. And 118A. According to this manufacturing method, the scattering of the LED units 44 can efficiently arrange the LED units 44 in the target arrangement, so that the image display device 20C can be manufactured efficiently.

In the above embodiment, the following modifications are possible.
First, in the above embodiment, the LED unit 44 emits light in three colors, but the LED unit 44 may emit light in at least one color. Also, the LED unit 44 may have a micro LED that generates white light.

Further, in the above embodiment, as shown by the dotted line in FIG. 10B, the suction holes 22Ca are formed in the area of the substrate 22C where the LED unit 44 is installed, and the LED unit 44 is used as a terminal portion of the substrate 22C. When fixing (welding), the LED unit 44 may be adsorbed via the suction holes 22Ca by a vacuum pump (not shown). Thereby, the LED unit 44 can be fixed to the substrate 22C more stably.
Moreover, in the above-mentioned embodiment, although a light emission part is a light emitting diode, a light emission part may be a semiconductor laser etc.

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 portion, 28A to 28I ... wiring, 30, 30A, 30B ... guide member, 42, 42A, 42B, 44: LED unit, 46R1, 46R2: wafer of red LED, 46B1, 46B2: wafer of blue LED, 46G: wafer of green LED

Claims (28)

1. A plurality of light emitting layers each emitting light;
   And a plurality of semiconductor layers joined to the plurality of light emitting layers such that the light is emitted in the plurality of light emitting layers when a voltage is applied,
   A light emitting element in which a plurality of the light emitting layers and a plurality of the semiconductor layers are joined in order in a predetermined direction.
2. The light emitting device according to claim 1, wherein the number of the plurality of semiconductor layers is larger than the number of the plurality of light emitting layers.
3. The light emitting device according to claim 1, wherein the number of the plurality of semiconductor layers is one more than the number of the plurality of light emitting layers.
4. The plurality of semiconductor layers have a first semiconductor layer and a second semiconductor layer different in conductivity type from each other,
   The light emitting device according to claim 2, wherein the first semiconductor layer and the second semiconductor layer are arranged symmetrically with respect to the predetermined direction.
5. The plurality of semiconductor layers have a first semiconductor layer and a second semiconductor layer different in conductivity type from each other,
   The plurality of light emitting layers and the plurality of semiconductor layers are arranged in the order of the first semiconductor layer, the light emitting layer, the second semiconductor layer, the light emitting layer, and the first semiconductor layer in the predetermined direction. The light emitting element as described in any one of Claim 2 to 4 which forms a light emission part.
6. The light emitting device according to claim 5, wherein the light emitting unit further includes the second semiconductor layer between the second semiconductor layer and the light emitting layer.
7. The plurality of light emitting layers have a first light emitting layer and a second light emitting layer that emit light of different wavelengths,
   The first semiconductor layer has a first layer joined to the first light emitting layer and a third layer joined to the second light emitting layer, and the second semiconductor layer is joined to the first light emitting layer And a fourth layer bonded to the second light emitting layer,
   The light emitting unit includes a first light emitting unit and a second light emitting unit including a first light emitting layer and a second light emitting layer, respectively.
   The light emitting device according to any one of claims 4 to 6, wherein the first light emitting layer and the second light emitting layer are arranged symmetrically with respect to the predetermined direction.
8. The plurality of light emitting layers have a first light emitting layer and a second light emitting layer that emit light of different wavelengths,
   The first semiconductor layer has a first layer joined to the first light emitting layer, and a third layer joined to the second light emitting layer, and the second semiconductor layer is formed on the first light emitting layer. A second layer to be joined, and a fourth layer to be joined to the second light emitting layer,
   The light emitting unit includes a first light emitting unit and a second light emitting unit including a first light emitting layer and a second light emitting layer, respectively.
   The second light emitting unit is formed by arranging the third layer, the second light emitting layer, the fourth layer, the second light emitting layer, and the third layer in order in the predetermined direction. The light-emitting element according to any one of 4 to 6.
9. In the second light emitting unit, the third layer and the second light emitting layer are arranged on one end side with respect to the predetermined direction, and the second light emitting layer and the third layer are arranged on the other end side. The light emitting element as described in.
10. The plurality of light emitting layers have a third light emitting layer that emits light of a wavelength different from that of the first and second light emitting layers,
    The first semiconductor layer has a fifth layer joined to the third light emitting layer, and the second semiconductor layer has a sixth layer joined to the third light emitting layer.
    The light emitting unit includes a third light emitting unit including the third light emitting layer,
    The light emitting device according to claim 8, wherein the first light emitting unit, the second light emitting unit, and the third light emitting unit are arranged symmetrically with respect to the predetermined direction.
11. The light emitting element according to any one of claims 7 to 10, wherein the size of the light emitting unit differs according to the color of the light emitted in the corresponding light emitting layer.
12. The light emitting device according to any one of claims 7 to 11, wherein at least one of the first and second light emitting units is a cylinder or a polygonal prism having a bottom of a circle or a polygon and a height in the predetermined direction. .
13. The light emitting device according to claim 12, wherein at least one of the first and second light emitting units has at least one of the bottom surface and the height different depending on a color of the light emitted in the corresponding light emitting layer.
14. The light emission according to any one of claims 1 to 13, wherein the plurality of light emitting layers have a green light emitting layer that emits light of a green wavelength, and the green light emitting layer is aligned at the center with respect to the predetermined direction. element.
15. A light emitting device according to any one of claims 1 to 14,
    A wiring on which power is supplied to the light emitting layer is formed, and a substrate to which the light emitting element is bonded.
16. The display device according to claim 15, further comprising: a guide unit that guides the light emitting element at a predetermined position where the light emitting element and the wiring are connected.
17. The display device according to claim 16, wherein the guide portion is formed such that a side surface of the light emitting element is in contact with the substrate.
18. The display device according to claim 16, wherein the guide portion is formed such that a bottom surface of the light emitting element is in contact with the substrate.
19. It is a manufacturing method which manufactures a light emitting element according to any one of claims 1 to 14,
    Arranging and joining the plurality of light emitting layers and the plurality of semiconductor layers in the predetermined direction so as to form the light emitting element;
    And D. cutting the joined light emitting elements in a direction intersecting with the predetermined direction.
20. The plurality of light emitting layers have a first light emitting layer that emits light of different wavelengths, a second light emitting layer, and a third light emitting layer.
    The semiconductor layer has a plurality of layers joined to the first light emitting layer, the second light emitting layer, and the third light emitting layer, respectively.
    Said joining is
    A first light emitting portion, a second light emitting portion, and a third light emitting portion are formed by joining the first light emitting layer, the second light emitting layer, the third light emitting layer, and the corresponding layers of the semiconductor layer. Manufacturing a first substrate, a second substrate, and a third substrate;
    20. The method according to claim 19, further comprising: aligning the first substrate, the second substrate, and the third substrate in the predetermined direction, and bonding the first substrate, the second substrate, and the third substrate with an insulating adhesive.
21. A method of manufacturing a display device according to any one of claims 15 to 18, wherein
    Scattering a plurality of the light emitting elements on the substrate;
    Bonding the scattered light emitting element and the substrate.
22. The method according to claim 21, wherein the scattering includes scattering a plurality of the light emitting elements having different sizes on the substrate.
23. And disposing, 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 scattering according to claim 21 or 22, wherein the scattering includes scattering the plurality of light emitting elements on the guide portion such that the light emitting elements are respectively accommodated in the plurality of openings of the guide portion. Method of manufacturing a display device
24. The display according to claim 23, wherein the scattering includes fixing the light emitting element on the substrate via a suction hole which the substrate has so that the light emitting element located at the predetermined position does not shift. Device manufacturing method.
25. The guide portion is a first guide portion that guides the light emitting element such that the bottom surface of the light emitting element contacts the substrate, and the side surface of the light emitting element in which the bottom surface contacts the substrate by the first guide portion And a second guide portion movable to contact the substrate and having the opening formed therein;
    In the scattering, guiding the light emitting element to the opening of the second guide portion such that the bottom surface of the light emitting element is in contact with the substrate through the first guide portion; 25. The method according to claim 23, further comprising moving the second guide portion such that a side surface contacts the substrate.
26. The method for manufacturing a display device according to any one of claims 23 to 25, further comprising removing the guide portion from above the substrate after the light emitting element and the substrate are joined.
27. The method for manufacturing a display device according to any one of claims 21 to 26, wherein the bonding includes bonding the light emitting element and the substrate by heat treatment.
28. The method for manufacturing a display device according to any one of claims 21 to 27, wherein the scattering includes scattering the light emitting element which has been neutralized by an ionizer onto the substrate.

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