Method of manufacturing display device and display device

Abstract

A manufacturing method of a display device is provided according to one embodiment, wherein the display device includes a mounting substrate and a plurality of light emitting elements mounted on the mounting substrate in a two-dimensional arrangement, the plurality of light emitting elements having a planar shape that is non-rotationally symmetric with respect to an axis perpendicular to a plane of the two-dimensional arrangement and is non-axially symmetric with respect to an axis parallel to the plane of the two-dimensional arrangement. The manufacturing method of the display device includes: a step of preparing the plurality of light emitting elements separately from each other; a step of preparing an arrangement guide member including a flat substrate and a set of through openings arranged two-dimensionally on the substrate, the set of openings having a planar shape similar to that of the light emitting elements and being slightly larger in size; and an arrangement step of horizontally disposing the arrangement guide member, embedding the plurality of light emitting elements in the set of openings of the arrangement guide member, and arranging the plurality of light emitting elements in correspondence with the two-dimensional arrangement of the set of openings.

Description

Technical Field

[0001] Embodiments of the present invention relate to a method for manufacturing a display device and the display device. Background Art

[0002] LED display devices using light-emitting diodes (LEDs), which are self-luminous elements, are known. In recent years, display devices using tiny light-emitting diode elements called microLEDs (hereinafter referred to as microLED display devices) have been developed as higher-precision display devices.

[0003] Unlike existing liquid crystal displays (LCDs) and organic EL displays, these micro-LED displays incorporate a large number of chip-shaped micro-LEDs within their display area. This makes it easier to achieve both high precision and large size, attracting attention as a next-generation display. Micro-LEDs are integrated using semiconductor processes onto a single-crystal sapphire wafer, for example.

[0004] In the manufacture of micro LED display devices, when mounting tiny micro LEDs on a mounting substrate, a method is adopted in which the arrangement on a wafer during integration is transferred to the mounting substrate.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2002-118124 Summary of the Invention

[0008] However, the above-mentioned mounting method cannot mount light-emitting elements that are separated and dispersed from the wafer, or light-emitting elements that are arranged on the wafer and do not match the pixel arrangement of the mounting substrate.

[0009] Light-emitting elements are miniaturized to the point where they are difficult to discern with the naked eye, and a large number of them are mounted on a mounting substrate. Therefore, in order to efficiently mount these separated light-emitting elements on the mounting substrate, it is necessary to pre-align them with high precision so that their orientation and two-dimensional arrangement match the pixel arrangement of the mounting substrate.

[0010] The present embodiment aims to provide a method for manufacturing a display device capable of efficiently arranging light-emitting elements and efficiently mounting the light-emitting elements on a mounting substrate, and a display device that can be manufactured using the manufacturing method.

[0011] In one embodiment, a method for manufacturing a display device includes a mounting substrate and a plurality of light-emitting elements mounted on the mounting substrate in a two-dimensional array, the plurality of light-emitting elements having a planar shape that is rotationally asymmetric about an axis perpendicular to the plane of the two-dimensional array and axisymmetrical about an axis parallel to the plane of the two-dimensional array. The method includes: preparing the plurality of light-emitting elements so that they are separated from one another; preparing an arrangement guide component comprising a flat substrate and a group of openings arranged two-dimensionally on the substrate, the group of openings having a plurality of openings extending therethrough and having a planar shape similar to that of the light-emitting elements but slightly larger than that of the light-emitting elements; and arranging the plurality of light-emitting elements in a horizontal position, embedding the plurality of light-emitting elements in the group of openings of the arrangement guide component, and arranging the plurality of light-emitting elements in correspondence with the two-dimensional arrangement of the group of openings.

[0012] A display device according to one embodiment includes a mounting substrate and a plurality of light-emitting elements mounted on the mounting substrate in a two-dimensional array. The plurality of light-emitting elements have planar shapes that are rotationally asymmetric about an axis perpendicular to the plane of the two-dimensional array and axisymmetrical about an axis parallel to the plane of the two-dimensional array. The plurality of light-emitting elements include a first light-emitting element emitting a first color, a second light-emitting element emitting a second color, and a third light-emitting element emitting a third color, and the planar shapes of these light-emitting elements are different from each other. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a perspective view schematically showing the configuration of a display device.

[0014] Figure 2 It is along Figure 1 Schematic partial cross-sectional view of line II-II.

[0015] Figure 3 It shows Figure 1 The planar shape and two-dimensional arrangement of multiple light-emitting elements.

[0016] Figure 4 This is a flowchart illustrating a method for manufacturing a display device according to one embodiment.

[0017] Figure 5 This is a perspective view schematically showing a light emitting element arrangement device used in a method for manufacturing a display device according to one embodiment.

[0018] Figure 6 It is a schematic partial cross-sectional view showing the arrangement process in sequence.

[0019] Figure 7 It is a schematic partial cross-sectional view showing the installation process in sequence.

[0020] Figure 8It is a plan view showing another example of the planar shape of the light emitting element.

[0021] Figure 9 This is a plan view showing the planar shape and two-dimensional arrangement of a plurality of light-emitting elements included in a display device that can be manufactured using a method for manufacturing a display device according to another embodiment.

[0022] Figure 10 This is a schematic partial cross-sectional view showing another example of a display device. DETAILED DESCRIPTION

[0023] The following describes the embodiment with reference to the accompanying drawings. In addition, the present disclosure is only an example, and appropriate changes that can be easily thought of by those skilled in the art with the purpose of the invention are of course included in the scope of the present invention. In addition, in order to make the description clearer, the width, thickness, shape, etc. of each part of the drawings are sometimes schematically shown compared with the actual form, but this is only an example and does not limit the interpretation of the present invention. In addition, in this specification and each figure, the same figure number is sometimes marked for the constituent elements that have the same or similar functions as the constituent elements described in the previous figures, and repeated detailed descriptions are appropriately omitted.

[0024] One embodiment of the present disclosure relates to a method for manufacturing a display device. A display device that can be manufactured using this method is described below. Here, a micro-LED display device using micro-light-emitting diodes (hereinafter referred to as micro-LEDs) as self-luminous elements is described.

[0025] Figure 1 It is a perspective view schematically showing the configuration of the display device DSP. Figure 2 It is along Figure 1 Schematic partial cross-sectional view of line II-II. Figure 3 It shows Figure 1 The planar shape and two-dimensional arrangement of the light-emitting element 10 are shown.

[0026] Figure 1 The three-dimensional space is defined by a first direction X, a second direction Y perpendicular to the first direction X, and a third direction Z perpendicular to both the first and second directions X and Y. The first and second directions X and Y are perpendicular to each other, but may intersect at an angle other than 90°. In this embodiment, the third direction Z is defined as upward, and the direction opposite to the third direction Z is defined as downward. Furthermore, when referring to "a second component above a first component" or "a second component below a first component," the second component may be positioned in contact with or separated from the first component.

[0027] The display device DSP includes a mounting substrate AR and a plurality of light emitting elements 10 mounted on the mounting substrate AR. Figure 1 In FIG. 1 , the display surface, that is, the light emitting surface of the display device DSP is shown facing upward and the back surface is shown facing downward.

[0028] like Figure 1 As shown, the mounting substrate AR has, for example, a rectangular shape. The main surface of the mounting substrate AR is parallel to the XY plane defined by the first direction X and the second direction Y. The thickness direction of the mounting substrate AR corresponds to the third direction Z. A plurality of light emitting elements 10 are mounted on the mounting substrate AR in a two-dimensional array.

[0029] like Figure 2 As shown, a pair of first wiring electrodes SE1 and second wiring electrodes SE2 are formed on the upper surface of the mounting substrate AR, corresponding to each light-emitting element 10. The pair of first wiring electrodes SE1 and second wiring electrodes SE2 are arranged two-dimensionally on the mounting substrate AR, similar to the light-emitting elements 10. The mounting substrate AR also includes an insulating substrate, various wiring layers formed on the insulating substrate, and pixel circuits corresponding to each light-emitting element 10 (including various switching elements such as drive transistors, various capacitors, etc.). A detailed description of the mounting substrate AR is omitted.

[0030] Each light-emitting element 10 is mounted so as to straddle the first wiring electrode SE1 and the second wiring electrode SE2. Each light-emitting element 10 includes a light-emitting layer 11 and a first electrode 12 and a second electrode 13 disposed below the light-emitting layer 11. The first electrode 12 is disposed on and electrically connected to the first wiring electrode SE1. The second electrode 13 is disposed on and electrically connected to the second wiring electrode SE2. The pair of first wiring electrode SE1 and second wiring electrode SE2 serves as the mounting region for the light-emitting element 10.

[0031] The light-emitting element 10 has a mounting surface P1, which serves as the surface connected to the mounting substrate AR, and a main light-emitting surface P2, which serves as the surface from which light is emitted. More precisely, the light-emitting element 10 emits light in all directions, including from the mounting surface P1. The main light-emitting surface P2 is the primary light-emitting surface when used as a display device DSP. In this embodiment, the surface having the first electrode 12 and the second electrode 13 serves as the mounting surface P1.

[0032] The plurality of light emitting elements 10 have a planar shape that is not rotationally symmetrical with respect to an axis perpendicular to the plane of the two-dimensional arrangement and is not axisymmetric with respect to an axis parallel to the plane of the two-dimensional arrangement. Figure 3As shown, in this embodiment, the light-emitting element 10 has a rectangular outline. The light-emitting element has dimensions of width W, length L, and thickness T (not shown) (thickness T < length L, width W). The light-emitting element 10 has a planar shape in which one of the four corners of the rectangle (width W < length L) is notched to form a non-axisymmetric triangle. A plurality of light-emitting elements 10 are arranged on the mounting substrate AR at intervals dX along the first direction X and at intervals dY along the second direction Y. Each light-emitting element 10 is arranged on the mounting substrate AR with the notch 15 facing the upper right.

[0033] The above-mentioned non-rotational symmetry means that the shape of a rotation around an axis perpendicular to the plane of the two-dimensional arrangement (XY plane) (an axis parallel to the third direction Z, such as the center point P) is consistent with the original shape only when rotated 360°, and is inconsistent with the original shape when rotated at other angles. In other words, the planar shape of the light-emitting element 10 has only one rotational symmetry. The above-mentioned non-axisymmetry means that it is not axisymmetric about any of the line segments parallel to the plane of the two-dimensional arrangement (XY plane) (for example, the center lines CL1 and CL2 along the first direction X and the second direction Y, respectively). In other words, even if the mounting surface P1 and the main light-emitting surface P2 are turned upside down, the planar shape of the light-emitting element 10 is inconsistent with the original shape.

[0034] As mentioned above, the light emitting element 10 is a micro LED chip, also known as a flip chip type micro LED. The area of ​​the light emitting element 10 is defined by width W×length L. This area is, for example, 25 μm 2 Above and 10000μm 2 The width W and length L are, for example, 5 μm or greater and 300 μm or less. Light-emitting layer 11 includes a P / N junction layer. Light-emitting element 10 is supplied with current via first wiring electrode SE1 and second wiring electrode SE2, with the first electrode 12 side designated as positive and the second electrode 13 side designated as negative. In this case, the P / N junction layer in light-emitting element 10 emits light, achieving the desired display.

[0035] (Manufacturing Method of Display Device DSP)

[0036] Hereinafter, a method for manufacturing a display device DSP according to an embodiment will be described with reference to the drawings.

[0037] Figure 4 This is a flowchart illustrating a method for manufacturing a display device according to one embodiment. Figure 5 This is a perspective view schematically showing a light emitting element arrangement device used in a method for manufacturing a display device according to one embodiment. Figure 6 It is a schematic partial cross-sectional view showing the arrangement process in sequence. Figure 7 It is a schematic partial cross-sectional view showing the installation process in sequence.

[0038] First, a plurality of light emitting elements 10 are prepared so as to be separated from each other (step S1 ).

[0039] The following describes the steps for integrating the above-mentioned light-emitting element 10 on a polycrystalline sapphire substrate. First, a single crystal sapphire substrate (wafer) is prepared as an insulating base layer. Next, after forming low-temperature and high-temperature buffer layers on the single crystal sapphire substrate, a second conductive type cladding layer, an active layer, and a first conductive type cladding layer are stacked using conventional methods to form a light-emitting layer. Through this stacking, a light-emitting diode with a double heterojunction structure is formed. Next, using conventional methods, an n-type electrode (first electrode) is formed in a manner electrically connected to the second conductive type cladding layer, and a p-type electrode (second electrode) is formed in a manner electrically connected to the first conductive type cladding layer. Next, a semiconductor process such as photolithography is used to form a notch and a separation groove that separates each light-emitting element 10 until the sapphire substrate is exposed. In addition, the above-mentioned separation groove and notch can also be formed using a cutting process instead of photolithography. In addition, the above-mentioned dividing groove and notch can also be formed by combining the above-mentioned photolithography and cutting processes. Through the above-mentioned process, the light-emitting element 10 can be integrated and formed on the sapphire substrate (wafer).

[0040] Next, the plurality of light-emitting elements 10 integrated on the sapphire substrate are separated from the sapphire substrate. Laser lift-off or other methods can be used for this separation. In this method, a high-output pulsed laser, such as an excimer laser, is first irradiated from the sapphire substrate side toward the light-emitting element 10 to be separated. This laser irradiation decomposes, for example, the gallium nitride layer near the interface between the sapphire substrate and the second conductivity-type cladding layer, which is a crystalline layer. This weakens the bonding strength at this interface, allowing separation.

[0041] In this embodiment, the plurality of light-emitting elements 10 prepared separately use a structure that does not include an insulating substrate layer, such as a sapphire substrate. In this configuration, since the light-emitting elements 10 do not include a hard insulating substrate layer, the aforementioned planar shape of the light-emitting elements 10 can be easily formed using microfabrication techniques such as semiconductor processes. Furthermore, since the thickness T of the light-emitting elements 10 can be reduced, the thickness of the display device DSP can also be reduced, which is preferable.

[0042] Furthermore, as the plurality of light emitting elements 10 prepared separately, light emitting elements that were previously separated and scattered from the wafer and discarded as unusable, or light emitting elements located at positions that do not match the pixel arrangement of the mounting substrate AR on the integrated wafer can be used.

[0043] Next, the alignment guide member 21 is prepared (step S2 ).

[0044] like Figure 5As shown, the arrangement guide member 21 includes a substrate and an opening group OP having a plurality of openings arranged two-dimensionally on the substrate and extending therethrough. The arrangement guide member 21 is disposed horizontally and is configured to allow the plurality of light-emitting elements 10 to be respectively embedded in the opening group OP of the arrangement guide member 21, so that the plurality of light-emitting elements 10 are arranged corresponding to the two-dimensional arrangement of the opening group OP.

[0045] The substrate is flat and has, for example, a rectangular shape. The substrate preferably has a thickness equal to the thickness T of the light-emitting elements 10 to be arranged. The substrate has an upper surface, which is located at the top when arranged horizontally, and a lower surface, which is located at the bottom. When the substrate is made of a material such as silicon or silicon oxide, the micro-openings OP can be formed using semiconductor processes such as photolithography.

[0046] In this embodiment, the planar shape of each opening in the opening group OP, as viewed from the top surface, is similar to the planar shape of the light-emitting element 10 as viewed from the main light-emitting surface P2. Specifically, each opening in the opening group OP, like the planar shape of the light-emitting element 10, has a non-axisymmetric triangular shape with one of the four corners of a rectangle notched. In this embodiment, the posture of each opening in the opening group OP, as viewed from the top, matches the posture of the light-emitting element 10 on the mounting substrate AR. Specifically, the openings in the opening group OP are arranged with the notch 15 facing upward and right, similar to the posture of the light-emitting element 10 on the mounting substrate AR. The planar shape of each opening in the opening group OP is similar to that of the light-emitting element 10, but slightly larger in size. The planar area of ​​each opening in the opening group OP is slightly larger than that of the light-emitting element 10, for example, preferably 1% to 10% larger.

[0047] In this embodiment, the center points of the openings of the opening group OP are arranged at intervals dX in the first direction X and at intervals dY in the second direction Y, similar to the two-dimensional arrangement of the light-emitting elements 10 on the mounting substrate AR. In other words, the two-dimensional arrangement of the openings of the opening group OP matches the two-dimensional arrangement of the light-emitting elements 10 on the mounting substrate AR.

[0048] Next, the prepared alignment guide member 21 is placed horizontally (step S3 ).

[0049] In this embodiment, the alignment guide member 21 is disposed on a horizontally disposed arrangement plate 22. The arrangement plate 22 is a flat plate and is disposed on the lower surface of the alignment guide member 21 so as to cover the opening group OP. The arrangement plate 22 has a rectangular outer shape with the same dimensions as the alignment guide member 21.

[0050] In this embodiment, the arrangement guide member 21 and the arrangement plate 22 are secured with fixings 23 to prevent them from shifting relative to each other. The fixings 23 are, for example, components that clamp the outer edges of the arrangement guide member 21 and the arrangement plate 22 to secure them. In this embodiment, the arrangement guide member 21 is connected to a vibration mechanism and an oscillation mechanism 24 that enable it to vibrate and oscillate minutely. The arrangement guide member 21 and the arrangement plate 22 are configured to vibrate and oscillate together as a single unit under the action of the vibration mechanism and oscillation mechanism 24.

[0051] Next, the plurality of light emitting elements 10 are respectively fitted into the opening groups OP of the arrangement guide member 21 , and the plurality of light emitting elements 10 are arranged corresponding to the two-dimensional arrangement of the opening groups OP (step S4 ).

[0052] Reference Figure 6 (a), (b), and (c) illustrate the arrangement process.

[0053] First, if Figure 6 As shown in FIG. 1 ( a ), a plurality of light emitting elements 10 separated from each other are placed on the horizontally arranged arrangement guide member 21 and the arrangement plate 22 , and are placed on the upper surface of the arrangement guide member 21 .

[0054] Next, if Figure 6 As shown in (b), the arrangement guide member 21 and the arrangement plate 22 are swung and vibrated by the vibration mechanism and the swing mechanism 24, so that the plurality of light emitting elements 10 are moved and rotated on the arrangement guide member 21. By the above movement and rotation, when the plurality of light emitting elements 10 are aligned with the two-dimensional arrangement and posture of each opening of the opening group OP, as shown in FIG. Figure 6 As shown in (c), the plurality of light emitting elements 10 are respectively embedded in the opening portion group OP. In this embodiment, each light emitting element 10 is embedded in each opening portion group OP with the mounting surface P1 side facing downward.

[0055] Specifically, each light-emitting element 10 is embedded in the openings of the opening group OP only when the light-emitting element 10 is positioned at an angle aligned with the openings of the opening group OP in the plane. This is because each light-emitting element 10 has a planar shape that is rotationally asymmetric about an axis perpendicular to the plane. Furthermore, each light-emitting element 10 is embedded in the openings of the opening group OP only when the mounting surface P1 of the light-emitting element 10 is oriented downward. This is because each light-emitting element 1 has a planar shape that is asymmetric about an axis parallel to the plane. Furthermore, the light-emitting elements 10 are embedded in the multiple openings of the opening group OP and arranged on the arrangement plate 22 to correspond to the two-dimensional arrangement of the openings of the arrangement guide member 21.

[0056] Next, the plurality of arranged light emitting elements 10 are mounted on the mounting substrate AR while maintaining the arranged state (step S5 ).

[0057] Reference Figure 7 (d), (e), (f), and (g) illustrate the installation process.

[0058] First, if Figure 7 As shown in (d), the arrangement guide member 21 is removed from the arrangement plate 22 and a transfer plate 30 is prepared. The transfer plate 30 is a temporary substrate for transferring the light emitting elements 10 while maintaining their arrangement. An adhesive layer 32 is applied to the surface of the base material 31 of the transfer plate 30.

[0059] Next, if the Figure 7 As shown in (d), the surface of the adhesive material layer 32 of the transfer plate 30 is pressed against the main light-emitting surface P2 of the arranged light-emitting elements 10, and the main light-emitting surface P2 side of each light-emitting element 10 is adhered and held to the surface of the adhesive material layer 32. Through this operation, the plurality of light-emitting elements 10 are transferred to the transfer plate 30 while maintaining their arrangement.

[0060] Next, if Figure 7 As shown in (e), a mounting substrate AR is prepared. Various wiring layers (not shown), pixel circuits (not shown), a first wiring electrode SE1 and a second wiring electrode SE2, etc. are formed on the mounting substrate AR in advance. As described above, a pair of first wiring electrodes SE1 and second wiring electrodes SE2 arranged on the upper surface of the mounting substrate AR function as a mounting area for the light emitting element 10. A conductive material for bonding is formed on the first wiring electrode SE1 and the second wiring electrode SE2 in advance. Next, as shown in the Figure 7 As shown in FIG. 5 (e), the positions of the first electrodes 12 and the second electrodes 13 are aligned and arranged from the transfer plate 30 on the first wiring electrodes SE1 and the second wiring electrodes SE2 of the mounting substrate AR.

[0061] Next, if Figure 7 As shown in (f), the mounting surface P1 of the light emitting element 10 on the transfer plate 30 is pressed against the aligned position on the mounting substrate AR. Figure 7 As shown in (f), the adhesive layer 32 bonded to the mounted light emitting element 10 is irradiated with laser light to destroy the adhesive layer 32, and the transfer plate 30 is removed from each light emitting element 10. As a result, the plurality of light emitting elements 10 are transferred and mounted on the mounting substrate AR while maintaining the arrangement on the transfer plate 30 ( Figure 7 (g)).

[0062] By repeating this mounting process for all pixels (all mounting regions on the mounting substrate AR), it is possible to manufacture a display device DSP in which the light emitting elements 10 are two-dimensionally arrayed on the mounting substrate AR.

[0063] In the method for manufacturing a display device DSP of this embodiment, since a plurality of light-emitting elements 10 are formed into a predetermined planar shape, their postures and two-dimensional arrangements can be aligned using an arrangement guide member 21. The light-emitting elements 10 are simply embedded in an opening group OP having a plurality of openings that are similar in planar shape and slightly larger in size, in a predetermined posture and two-dimensional arrangement. Therefore, a large number of microscopic light-emitting elements 10 can be arranged with high precision, and the transfer and mounting of the light-emitting elements 10 onto the mounting substrate AR can be made more efficient. Therefore, according to this embodiment, the display device DSP can be manufactured efficiently, and a display device DSP with reduced manufacturing costs can be provided.

[0064] Furthermore, the method for manufacturing a display device DSP according to this embodiment enables efficient alignment of multiple, mutually separated light-emitting elements 10. Consequently, it is possible to reuse light-emitting elements that were previously discarded and unusable, separated and dispersed from an integrated wafer, or located on an integrated wafer at a position that does not match the pixel arrangement of the mounting substrate AR, to manufacture the display device DSP. Consequently, the manufacturing cost of the display device DSP can be further reduced.

[0065] Furthermore, according to the method for manufacturing the display device DSP of this embodiment, during the arrangement process, the arrangement guide member 21 is swung and vibrated to move and rotate the plurality of light-emitting elements 10. This allows the plurality of light-emitting elements 10 to be efficiently fitted into the opening group OP. Consequently, the plurality of light-emitting elements 10 can be efficiently aligned and arranged using the arrangement guide member 21.

[0066] Furthermore, according to the method for manufacturing the display device DSP of this embodiment, during the arrangement step, the light-emitting elements 10 are arranged with the mounting surface P1 side having the first electrode 12 and the second electrode 13 facing downward. Therefore, during the mounting step following the arrangement step, the main light-emitting surface P2 side of the light-emitting element 10 can be held by the transfer sheet 30, allowing the mounting surface P1 on the opposite side to the main light-emitting surface P2 to be mounted on the mounting substrate AR. As a result, during the mounting step, the light-emitting element 10 can be mounted without having to flip the top and bottom surfaces of the light-emitting element 10, further improving the efficiency of mounting the light-emitting element 10 on the mounting substrate AR.

[0067] Furthermore, in the above embodiment, an example is shown and described in which the two-dimensional arrangement of the multiple openings of the opening group OP of the arrangement guide member 21 matches the two-dimensional arrangement of the light-emitting elements 10 on the mounting substrate AR, but the present invention is not limited to this. The two-dimensional arrangement of the multiple openings of the opening group OP may also be enlarged or reduced by a predetermined factor in the first direction X and / or the second direction Y compared to the two-dimensional arrangement of the light-emitting elements 10 on the mounting substrate AR. For example, it is preferable to reduce the two-dimensional arrangement of the multiple openings of the opening group OP of the arrangement guide member 21 by condensing them as described above, thereby reducing the size of the arrangement guide member 21. If the multiple openings of the opening group OP of the arrangement guide member 21 are densely arranged, the probability of each of the multiple light-emitting elements 10 being embedded in the multiple openings of the opening group OP increases during the arrangement process. As a result, the arrangement process can be made more efficient. In this case, during the mounting process, it is necessary to enlarge the two-dimensional arrangement of the multiple light-emitting elements 10, which has been densely arranged in the arrangement process, by a predetermined factor before mounting.

[0068] In addition, in the above embodiment, if Figure 8 As shown in (a), the light emitting element 10 has a planar structure in which one of the four corners of the rectangle is cut away to form a non-axisymmetric triangular shape. However, the shape of the light emitting element 10 is not limited to this, as long as it has the above-mentioned non-rotational symmetry and non-axisymmetry. The light emitting element 10 may also have a cutout portion other than a triangular shape. For example, Figure 8 As shown in (b), the light emitting element 10 may have a planar shape in which one of the four corners of the rectangle is cut off to form a rectangular shape. In addition, the light emitting element 10 may have two or more cutouts. For example, Figure 8 As shown in (c), the light emitting element 10 may have a planar shape in which one of the four corners of the rectangle is cut off to form a triangle, and another corner is cut off to form a rectangle. Furthermore, the general shape of the light emitting element may be a shape other than a rectangle, and may be a polygonal shape such as a triangle, a circle, or the like.

[0069] (Method for Manufacturing Display Device According to Another Embodiment)

[0070] A method for manufacturing a display device according to another embodiment will be described. Hereinafter, a display device that can be manufactured using the method for manufacturing a display device according to another embodiment will be described.

[0071] Figure 9This is a top view schematically illustrating the planar shape and two-dimensional arrangement of multiple light-emitting elements included in a display device that can be manufactured using a display device manufacturing method according to another embodiment. Multiple light-emitting elements 10 include a first light-emitting element 10a that emits a first color, a second light-emitting element 10b that emits a second color, and a third light-emitting element 10c that emits a third color. These light-emitting elements have different planar shapes. In one example, the first color is red, the second color is green, and the third color is blue.

[0072] In this display device, the first light emitting element 10a has the same Figure 8 (a) has the same planar shape, and the second light emitting element 10b has the same Figure 8 The third light emitting element 10c has the same planar shape as (b). Figure 8 (c) The same planar shape. For example, the approximate dimensions of light-emitting elements 10a, 10b, and 10c, namely, width W, length, and thickness T, are identical. Light-emitting elements 10a, 10b, and 10c are arranged with notches 15a, 15b, and 15c facing upward and right. Light-emitting elements 10a, 10b, and 10c are arranged along the second direction Y according to the two-dimensional arrangement of light-emitting element 10 described above, and are alternately arranged in this order in the first direction X.

[0073] In such a method for manufacturing a display device, it is preferred that the following components are prepared separately in the process of preparing the above-mentioned arrangement guide component: a first arrangement guide component, which has an opening group having a plurality of openings whose planar shape is similar to that of the first light-emitting element 10a and whose size is slightly larger; a second arrangement guide component, which has an opening group having a plurality of openings whose planar shape is similar to that of the second light-emitting element 10b and whose size is slightly larger; and a third arrangement guide component, which has an opening group having a plurality of openings whose planar shape is similar to that of the third light-emitting element 10c and whose size is slightly larger.

[0074] The first light-emitting elements 10a are preferably embedded in the first opening group of the first alignment guide member, and not embedded in the second opening group of the second alignment guide member or the third opening group of the third alignment guide member. The second light-emitting elements 10b are preferably embedded in the second opening group of the second alignment guide member, and not embedded in the first opening group of the first alignment guide member or the third opening group of the third alignment guide member. The third light-emitting elements 10c are preferably embedded in the third opening group of the third alignment guide member, and not embedded in the first opening group of the first alignment guide member or the second opening group of the second alignment guide member.

[0075] In addition, the above-mentioned arrangement process preferably includes a first arrangement process of arranging the first light-emitting element 10a by a first arrangement guide component, a second arrangement process of arranging the second light-emitting element 10b by a second arrangement guide component, and a third arrangement process of arranging the third light-emitting element 10c by a third arrangement guide component.

[0076] In addition, in the above-mentioned mounting process, it is preferred to include a first mounting process of mounting the first light-emitting element 10a arranged through the above-mentioned first arrangement process on the mounting substrate while maintaining the arrangement state, a second mounting process of mounting the second light-emitting element 10b arranged through the above-mentioned second arrangement process on the mounting substrate while maintaining the arrangement state, and a third mounting process of mounting the third light-emitting element 10c arranged through the above-mentioned third arrangement process on the mounting substrate while maintaining the arrangement state.

[0077] Next, a method for manufacturing a display device according to another embodiment will be described.

[0078] First, as the light-emitting elements separated from each other, for example, a light-emitting element in which the light-emitting elements 10 a , 10 b , and 10 c are mixed can be used ( S1 ′ step).

[0079] Next, the first arrangement guide component is horizontally arranged and fixed on the arrangement plate (S2' process). Next, the above-mentioned multiple light-emitting elements are placed on the first arrangement guide component (S3' process), and the first arrangement guide component is used to arrange the first light-emitting element 10a on the arrangement plate (first arrangement process (S4' process)). At this time, the planar shapes of the light-emitting elements 10a, 10b, and 10c are different from each other. Since the planar shapes of the first opening group, the second opening group, and the third opening group, which are similar in shape and slightly larger in size, are also different from each other, only the first light-emitting element 10a is selectively arranged through the first arrangement guide component. Next, the arranged first light-emitting element 10a on the arrangement plate is transferred to the transfer plate while maintaining the arrangement, and is installed in the corresponding mounting area on the mounting substrate (first mounting process (S5' process)).

[0080] Next, a second alignment guide is placed horizontally and fixed to the arrangement plate in place of the first alignment guide (step S2′). Next, the plurality of light-emitting elements remaining on the first alignment guide are placed on the second alignment guide (step S3′), and the second alignment guide is used to selectively arrange the second light-emitting elements 10b on the arrangement plate (second arrangement step (step S4′)). Next, the second light-emitting elements 10b arranged on the arrangement plate are transferred to a transfer plate while maintaining their arrangement, and then mounted in corresponding mounting areas on the mounting substrate AR (second mounting step (step S5′)).

[0081] Next, the third alignment guide member is placed horizontally and fixed to the arrangement plate in place of the second alignment guide member (step S2′). Next, the plurality of light-emitting elements remaining on the second alignment guide member are placed on the third alignment guide member (step S3′), and the third alignment guide member is used to selectively arrange the third light-emitting elements 10c on the arrangement plate (third arrangement step (step S4′)). Next, the third light-emitting elements 10c arranged on the arrangement plate are transferred to the transfer plate while maintaining their arrangement, and then mounted in corresponding mounting areas on the mounting substrate AR (third mounting step (step S5′)).

[0082] The manufacturing method of a display device DSP according to another embodiment can achieve the same effects as the above-described embodiment. Furthermore, in such a configuration, previously unusable and discarded light-emitting elements separated from an integrated wafer and mixed with the light-emitting elements 10a, 10b, and 10c can be reused as the light-emitting elements to be mounted to manufacture the display device DSP. As a result, the manufacturing cost of the display device DSP can be further reduced.

[0083] In addition, in the manufacturing method of the display device of the other embodiments described above, a mixture of light-emitting elements 10a, 10b, and 10c is used, but light-emitting elements that are individually distinguished can also be used. Specifically, the light-emitting elements 10a, 10b, and 10c can also be mounted on the mounting substrate through their own separate arrangement and mounting steps. In addition, the light-emitting elements 10a, 10b, and 10c are described as having different shapes of the cutouts 15. However, for example, different planar shapes can also refer to configurations in which the approximate shapes are greatly different from each other, such as triangles, other polygonal shapes, or circular shapes. In addition, the light-emitting elements 10a, 10b, and 10c can be, for example, similar in shape but different only in planar area, or can be, for example, configured with successively smaller planar areas. In such a configuration, it is preferable to perform each arrangement step after distinguishing the light-emitting elements 10a, 10b, and 10c using an arrangement guide component having a group of openings corresponding to the differences in the approximate shapes and planar areas.

[0084] Furthermore, the display device manufactured according to the above embodiment is not limited to the above example; some components may be added or omitted. For example, an insulating layer may be formed on the first and second wiring electrodes disposed on the mounting substrate. An opening may be formed in the insulating layer to expose a portion of the first and second wiring electrodes, and the first and second electrodes of the light-emitting element may be connected to the exposed portions. Furthermore, a planarizing film may be formed on the mounting substrate to cover the plurality of light-emitting elements and the insulating layer for planarization.

[0085] In addition, the display device manufactured in the above embodiment shows and describes an example in which the light emitting element 10 is a so-called flip-chip type micro LED, but the present invention is not limited thereto. For example, the light emitting element may also be a so-called face-up type micro LED, or Figure 10 The light-emitting element 10' shown includes a first electrode 12' disposed below a light-emitting layer 11' and a second electrode 13' disposed above the light-emitting layer 11'.

[0086] The following instructions Figure 10 Another example of a display device DSP' is shown. Figure 10 This is a partial cross-sectional view schematically showing another example of a display device. The light-emitting element 10′ has the same planar shape and outer dimensions as the light-emitting element 10′ described above. The light-emitting element 10′ is mounted on the mounting substrate AR′ in a two-dimensional arrangement similar to the light-emitting element 10. The light-emitting element 10′ is mounted on the first wiring electrode SE1′. On the upper surface of the mounting substrate AR′, a first wiring electrode SE1′ is formed corresponding to each of the plurality of light-emitting elements 10′. The first wiring electrode SE1′ is arranged on the mounting substrate AR′ in the same two-dimensional arrangement as the first wiring electrode SE1 and the second wiring electrode SE2. The first electrode 12′ is arranged on the first wiring electrode SE1′ and is electrically connected. The first electrode 12′ and the second electrode 13′ are arranged opposite each other with the light-emitting layer 11′ interposed therebetween. In this light-emitting element 10′, the side having the first electrode 12′ functions as the mounting surface P1, and the side having the second electrode 13′ functions as the main light-emitting surface P2.

[0087] The spaces between the multiple light-emitting elements 10' mounted on the mounting substrate AR are filled with an inter-element insulating film PS. The upper surface of the inter-element insulating film PS is flattened to expose the second electrode 13' of each light-emitting element 10'. A counter electrode CE made of a transparent conductive film such as indium oxide is formed on the inter-element insulating film PS and the second electrode 13'. The counter electrode CE is commonly connected to the second electrodes 13' of the multiple light-emitting elements 10'. When current is supplied to the light-emitting elements 10' via the first wiring electrode SE1 and the counter electrode CE, the P / N junction emits light, achieving the desired display.

[0088] The display device DSP' having such a configuration can also be manufactured using the same method as that for manufacturing the display device DSP according to the above-described embodiment.

[0089] While several embodiments of the present invention have been described, these embodiments are provided as examples and are not intended to limit the scope of the invention. The above embodiments may be implemented in various other ways, and various omissions, substitutions, and modifications may be made without departing from the spirit of the invention. The above embodiments and their variations are intended to be encompassed by the invention as set forth in the claims and their equivalents, as long as they fall within the scope and spirit of the invention.

[0090] Description of Reference Numerals

[0091] DSP display device, AR mounting substrate, SE1 first wiring electrode, SE2 second wiring electrode, 10 light-emitting element, 11 light-emitting layer, 12 first electrode, 13 second electrode, 15 notch, SE1 first wiring electrode, SE2 second wiring electrode, 20 arrangement device for light-emitting element, 21 arrangement guide component, OP opening group, 22 arrangement plate, 23 fixing part, 24 vibration mechanism (swing mechanism), 30 transfer plate, CE opposing electrode, P1 mounting surface, P2 main light-emitting surface.

Claims

1. A method for manufacturing a display device, wherein: The display device includes a mounting substrate and a plurality of light-emitting elements mounted on the mounting substrate in a two-dimensional array, the plurality of light-emitting elements having a planar shape that is non-rotationally symmetric about an axis perpendicular to a plane of the two-dimensional array and non-axisymmetric about an axis parallel to the plane of the two-dimensional array. The method for manufacturing the display device is characterized by comprising: a step of preparing a plurality of the light-emitting elements so as to separate the plurality of the light-emitting elements from each other; A step of preparing an arrangement guide member, the arrangement guide member comprising a flat substrate and a group of openings arranged two-dimensionally on the substrate, the group of openings having a planar shape similar to that of the light emitting element and slightly larger than that of the light emitting element; The process of disposing the arrangement guide component on a horizontally arranged arrangement plate, and fixing the arrangement guide component and the arrangement plate with a fixing member in a manner that the arrangement guide component and the arrangement plate are not misaligned with each other; an arrangement step of respectively embedding the plurality of light-emitting elements into the plurality of openings of the opening group of the arrangement guide component, so that the plurality of light-emitting elements are arranged on the arrangement plate corresponding to the two-dimensional arrangement of the opening group; a step of removing the arrangement guide component from the arrangement plate; a step of transferring the plurality of light emitting elements arranged on the arrangement plate to a transfer plate while maintaining the arrangement state of the plurality of light emitting elements; as well as The mounting step is to transfer the plurality of light emitting elements from the transfer sheet to the mounting substrate while maintaining the arrangement of the plurality of light emitting elements.

2. The method for manufacturing a display device according to claim 1, wherein: The plurality of light emitting elements are respectively planar micro light emitting diodes.

3. The method for manufacturing a display device according to claim 1, wherein: In the arrangement step, the plurality of light emitting elements are placed on the arrangement guide member, and the arrangement guide member is swung and vibrated to move and rotate the plurality of light emitting elements, thereby fitting the plurality of light emitting elements into the opening group.

4. The method for manufacturing a display device according to claim 1, wherein: In the arranging step, the plurality of light emitting elements are arranged with their main light emitting surfaces facing upward. In the mounting step, the light emitting element is transferred and mounted on a mounting substrate while being held on the main light emitting surface side by the transfer sheet.

5. The method for manufacturing a display device according to claim 1, wherein: The plurality of light-emitting elements prepared include a first light-emitting element emitting a first color, a second light-emitting element emitting a second color, and a third light-emitting element emitting a third color, wherein the planar shapes of these light-emitting elements are different from each other. The prepared arrangement guide component includes: a first arrangement guide component, which has a first opening portion group having a plurality of opening portions extending through it, the planar shape of which is similar to that of the first light-emitting element and slightly larger in size; a second arrangement guide component, which has a second opening portion group having a plurality of opening portions extending through it, the planar shape of which is similar to that of the second light-emitting element and slightly larger in size; and a third arrangement guide component, which has a third opening portion group having a plurality of opening portions extending through it, the planar shape of which is similar to that of the third light-emitting element and slightly larger in size. The arrangement process includes: a first arrangement process of arranging the first light-emitting element corresponding to the two-dimensional arrangement of the first opening portion group using the first arrangement guiding component; a second arrangement process of arranging the second light-emitting element corresponding to the two-dimensional arrangement of the second opening portion group using the second arrangement guiding component; and a third arrangement process of arranging the third light-emitting element corresponding to the two-dimensional arrangement of the third opening portion group using the third arrangement guiding component.

6. The method for manufacturing a display device according to claim 1, wherein: Each of the plurality of light emitting elements has a planar shape in which one of the four corners of a rectangle is cut off.

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