Method for manufacturing a display device and substrate for manufacturing a display device

Abstract

This specification discloses a substrate for highly reliably transferring a semiconductor light-emitting element and a method for manufacturing a display device using the substrate. Specifically, when self-assembling semiconductor light-emitting elements on an assembly substrate using an electromagnetic field, an assembly groove for assembling and aligning the semiconductor light-emitting elements is formed on the assembly substrate. The alignment semiconductor light-emitting elements assembled into the assembly groove are used for alignment in the step of finally transferring them to a wiring substrate. Different from the existing alignment keys, the alignment semiconductor light-emitting elements reflect the arrangement errors of the semiconductor light-emitting elements that occur during the transfer process after assembly. Therefore, when transferring the semiconductor light-emitting elements to the wiring substrate based on the alignment semiconductor light-emitting elements, the transfer accuracy can be improved.

Description

Technical Field

[0001] The present invention is applicable to the technical field related to display devices, for example, it relates to a manufacturing method of a display device using micro LEDs (Light Emitting Diodes) and a substrate for manufacturing a display device. Background Art

[0002] In recent years, in the field of display technology, display devices with excellent characteristics such as thinness and flexibility have been continuously developed. On the contrary, currently commercialized main displays are represented by LCD (Liquid Crystal Display) and OLED (Organic Light Emitting Diodes).

[0003] However, for LCDs, there are problems of slow response time and difficulty in achieving flexibility, and for OLEDs, there are problems of short lifespan and poor mass production yield.

[0004] On the other hand, light emitting diodes (LEDs) are well-known as semiconductor light emitting elements that convert current into light. Since the red LED using GaAsP (gallium arsenide phosphide) compound semiconductor was commercialized in 1962, together with GaP:N-based green LEDs, they have been used as light sources for displaying images of electronic devices including information and communication devices. Therefore, a solution can be proposed to solve the above problems by using the semiconductor light emitting elements to implement a display. Compared with the light emitting elements based on filaments, the semiconductor light emitting elements have various advantages such as long lifespan, low power consumption, excellent initial driving characteristics, and high vibration resistance.

[0005] However, in order to use semiconductor light emitting elements to implement a large-area and high-pixel display device, a very large number of semiconductor light emitting elements need to be accurately assembled or transferred to the wiring substrate of the display device.

[0006] Therefore, the present invention provides a manufacturing method of a display device in which semiconductor light emitting elements are transferred to a wiring substrate with a minimum alignment error and a substrate for manufacturing the display device. Summary of the Invention

[0007] Problems to be Solved by the Invention

[0008] An object of an embodiment of the present invention is to provide a new manufacturing method with high reliability for manufacturing a display device using semiconductor light emitting elements.

[0009] Another object of an embodiment of the present invention is to provide an assembly substrate and a wiring substrate that can minimize alignment errors during the transfer process when transferring semiconductor light-emitting elements to manufacture a large-area display device.

[0010] Furthermore, another object of an embodiment of the present invention is to solve various problems not mentioned herein. Those skilled in the art can understand through the overall spirit of the specification and the drawings.

[0011] Technical solutions for solving the problems

[0012] A method for manufacturing a display device using semiconductor light-emitting elements for achieving the above object, characterized by comprising: a step of assembling a lighting semiconductor light-emitting element into a first assembly groove of an assembly substrate; a step of assembling an alignment semiconductor light-emitting element into a second assembly groove of the assembly substrate; a step of transferring the semiconductor light-emitting element assembled into the assembly substrate from the assembly substrate to a transfer substrate; and a step of transferring the semiconductor light-emitting element transferred to the transfer substrate from the transfer substrate to a wiring substrate. In the step of assembling the lighting semiconductor light-emitting element and the alignment semiconductor light-emitting element into the assembly substrate, self-assembly is achieved by using an electric field and a magnetic field.

[0013] As an embodiment, it is characterized in that the lighting semiconductor light-emitting element and the alignment semiconductor light-emitting element are semiconductor light-emitting elements having the same structure formed by the same process.

[0014] As an embodiment, the step of assembling the semiconductor light-emitting element into the first assembly groove or the second assembly groove of the assembly substrate includes: a step of putting the semiconductor light-emitting element into a fluid chamber; a step of disposing the assembly substrate on the upper side of the fluid chamber; a step of using an assembly device having a magnetic body to make the semiconductor light-emitting element floating in the fluid chamber contact the first assembly groove or the second assembly groove of the assembly substrate; and a step of assembling the semiconductor light-emitting element into the first assembly groove or the second assembly groove based on an electric field applied through an assembly electrode formed on the assembly substrate.

[0015] As an embodiment, the transfer substrate includes a plurality of protrusions formed at positions corresponding to the lighting semiconductor light-emitting element and the alignment semiconductor light-emitting element assembled into the assembly substrate. The step of transferring from the assembly substrate to the transfer substrate includes: a step of overlapping the assembly substrate and the transfer substrate so that the protrusions and the semiconductor light-emitting elements overlap each other; and a step of removing the assembly substrate after the overlapping semiconductor light-emitting elements are in contact with and fixed to the protrusions.

[0016] As an embodiment, it is characterized in that the assembly substrate and the transfer substrate have alignment keys (Align keys) with the same uneven structure for alignment at corresponding positions with each other.

[0017] As an embodiment, it is characterized in that the step of transferring the semiconductor light-emitting element assembled to the assembly substrate to the transfer substrate includes: the step of overlapping the alignment keys formed at corresponding positions of the assembly substrate and the transfer substrate with each other.

[0018] As an embodiment, the step of transferring the semiconductor light-emitting element transferred to the transfer substrate from the assembly substrate to the wiring substrate includes: the step of aligning the transfer substrate and the wiring substrate (Alignment) so that the semiconductor light-emitting element is disposed in a region corresponding to the semiconductor light-emitting element transferred to the transfer substrate in the entire region of the wiring substrate; and, after fixing the semiconductor light-emitting element to the region corresponding to the semiconductor light-emitting element of the wiring substrate, the step of removing the transfer substrate.

[0019] As an embodiment, it is characterized in that the wiring substrate is formed of a light-transmissive material, and the step of aligning the transfer substrate and the wiring substrate (Alignment) is performed using an image captured by a camera disposed on the back surface of the wiring substrate.

[0020] As an embodiment, it is characterized in that in the step of aligning the transfer substrate and the wiring substrate (Alignment), using the image captured by the camera, the regions corresponding to the semiconductor light-emitting element of the transfer substrate and the semiconductor light-emitting element of the wiring substrate are overlapped.

[0021] As an embodiment, it is characterized in that the transfer substrate and the wiring substrate have alignment keys with the same uneven structure for alignment at corresponding positions with each other.

[0022] As an embodiment, the step of aligning the transfer substrate and the wiring substrate includes: a first alignment step of overlapping the alignment keys formed at corresponding positions of the transfer substrate and the wiring substrate with each other; and a second alignment step of overlapping the alignment semiconductor light-emitting element transferred to the transfer substrate and the alignment mark (Align mark) of the wiring substrate formed at a position corresponding to the alignment semiconductor light-emitting element.

[0023] As an embodiment, after the step of transferring the semiconductor light-emitting element to the wiring substrate, it includes: the step of performing a wiring process to electrically connect the lighting semiconductor light-emitting element to the wiring substrate.

[0024] As an embodiment, it includes the step of coating a substance with low transmittance on the upper part of the semiconductor light-emitting element for alignment.

[0025] As an embodiment, it is characterized in that the assembly substrate includes: a first assembly substrate, to which a first semiconductor light-emitting element that emits light of a first color when driving the display device is assembled; and a second assembly substrate, to which a second semiconductor light-emitting element that emits light of a second color different from the first color is assembled.

[0026] A display device using a plurality of semiconductor light-emitting elements according to another embodiment of the present invention is characterized in that it includes: a wiring substrate; and a plurality of semiconductor light-emitting elements located on the wiring substrate, the plurality of semiconductor light-emitting elements including a semiconductor light-emitting element for illumination and a semiconductor light-emitting element for alignment, the semiconductor light-emitting element for illumination and the semiconductor light-emitting element for alignment having the same shape and the same light-emitting color, the semiconductor light-emitting element for illumination being electrically connected to a wiring electrode of the wiring substrate, and a dark film layer with low light transmittance being provided on the top surface of the semiconductor light-emitting element for alignment.

[0027] As an embodiment, it is characterized in that the number of the semiconductor light-emitting elements for illumination per same area in the wiring substrate is more than 100 times that of the semiconductor light-emitting elements for alignment.

[0028] As an embodiment, it is characterized in that the wiring substrate further includes alignment keys having a concavo-convex structure.

[0029] As an embodiment, it is characterized in that the semiconductor light-emitting element is an LED (Micro-LED) having a size in micrometer units.

[0030] Advantages of the invention

[0031] According to an embodiment of the present invention, it is possible to provide a new manufacturing method with high reliability for manufacturing a display device using semiconductor light-emitting elements.

[0032] Specifically, when self-assembling semiconductor light-emitting elements on an assembly substrate using an electromagnetic field, an assembly groove for assembling the semiconductor light-emitting element for alignment is formed on the assembly substrate. The semiconductor light-emitting element for alignment assembled into the assembly groove is used for alignment in the step of transferring to a final wiring substrate. Different from the existing alignment keys, the semiconductor light-emitting element for alignment reflects the arrangement error of the semiconductor light-emitting elements that will occur during the transfer process after assembly. Therefore, when transferring the semiconductor light-emitting elements to the wiring substrate with the semiconductor light-emitting element for alignment as a reference, the transfer accuracy can be improved.

[0033] Furthermore, according to another embodiment of the present invention, there are additional technical effects not mentioned herein. Those skilled in the art can understand through the overall spirit of the specification and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a conceptual diagram showing an embodiment of a display device using a semiconductor light-emitting element of the present invention.

[0035] Figure 2 is Figure 1 a partial enlarged view of part A of

[0036] Figure 3a and Figure 3b is a cross-sectional view taken along line B-B and line C-C of Figure 2

[0037] Figure 4 is a conceptual diagram showing a flip-chip type semiconductor light-emitting element of FIG. 3.

[0038] Figures 5a to 5c is a conceptual diagram showing various ways of realizing colors related to a flip-chip type semiconductor light-emitting element.

[0039] Figure 6 is a flowchart showing a method of manufacturing a display device including semiconductor light-emitting elements that emit red R, green G, and blue B light.

[0040] Figure 7 is a diagram showing an embodiment of a method of assembling a semiconductor light-emitting element to a substrate by a self-assembly method.

[0041] Figure 8 is Figure 7 an enlarged view of part D of

[0042] Figure 9 is a flowchart showing a process of assembling a semiconductor light-emitting element for illumination and a semiconductor light-emitting element for alignment by a self-assembly method.

[0043] Figure 10 is a cross-sectional view of a semiconductor light-emitting element for illumination and a semiconductor light-emitting element for alignment assembled to an assembly substrate by a self-assembly method.

[0044] Figure 11 is a cross-sectional view showing a method of manufacturing a display device of the present invention using an assembly substrate and a wiring substrate.

[0045] Figure 12 is a top view showing an assembly substrate of the present invention and semiconductor light-emitting elements assembled to the assembly substrate.

[0046] Figure 13 ​It is a top view showing a transfer substrate of the present invention and a semiconductor light-emitting element transferred to the transfer substrate.

[0047] Figure 14 It is a top view showing a wiring substrate of the present invention and a semiconductor light-emitting element transferred to the wiring substrate.

[0048] Figure 15 It is a top view showing a semiconductor light-emitting element transferred only to a partial area of a wiring substrate.

[0049] Figure 16 It is a top view after a wiring process is performed on a semiconductor light-emitting element transferred to a wiring substrate. Detailed Description of the Invention

[0050] Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the drawings. The same or similar components are given the same reference numerals regardless of the reference numerals, and redundant descriptions thereof will be omitted. In the following description, the suffixes "module" and "section" for components are given or mixed only for convenience of writing the specification, and do not have their own meanings or functions for mutual distinction. In addition, in the process of describing the embodiments disclosed in this specification, when it is determined that a detailed description of related well-known technologies will make the gist of the embodiments disclosed in this specification unclear, the detailed description thereof will be omitted. In addition, it should be noted that the drawings are only for facilitating the understanding of the embodiments disclosed in this specification and should not be construed as limiting the technical ideas disclosed in this specification.

[0051] Furthermore, although each drawing is described for convenience of explanation, other embodiments achieved by those skilled in the art by combining at least two or more drawings also fall within the scope of the claims of the present invention.

[0052] In addition, it should be understood that when an element such as a layer, a region, or a substrate is present "on" another component, it may be directly on the other component or an intermediate component may also be present between them.

[0053] The concept of the display device described in this specification encompasses all display devices that display information using unit pixels or a set of unit pixels. Therefore, it can be applied not only to finished products but also to components. For example, a panel corresponding to a component of a digital TV also independently corresponds to the display device in this specification. Finished products can include mobile phones, smart phones, laptop computers, digital broadcast terminals, personal digital assistants (PDAs), portable multimedia players (PMPs), navigators, slate PCs, tablet PCs, ultra books, digital TVs, desktop computers, etc.

[0054] However, those skilled in the art will easily understand that the configurations of the embodiments described in this specification can be applied to devices capable of displaying, even in the form of new products developed in the future.

[0055] In addition, the concept of the semiconductor light-emitting element mentioned in this specification encompasses LEDs, micro LEDs, etc., and they can be used in combination.

[0056] Figure 1 It is a conceptual diagram showing an embodiment of the display device of the present invention using a semiconductor light-emitting element.

[0057] As Figure 1 shown, the information processed by the control unit (not shown) of the display device 100 can be displayed through a flexible display.

[0058] The flexible display includes, for example, a display that can be bent, folded, twisted, folded, or curled by an external force.

[0059] Furthermore, the flexible display can be, for example, a display that maintains the display characteristics of an existing flat panel display while being manufactured on a thin and flexible substrate that can be bent, folded, folded, or curled like paper.

[0060] In a state where the flexible display cannot be bent (for example, a state with an infinite radius of curvature, hereinafter referred to as the first state), the display area of the flexible display is flat. In a state bent from the first state by an external force (for example, a state with a finite radius of curvature, hereinafter referred to as the second state), the display area can be curved. As Figure 1As shown, the information displayed in the second state may be visual information output to the surface. Such visual information is achieved by independently controlling the light emission of sub-pixels arranged in a matrix form. The sub-pixel, for example, refers to the minimum unit for implementing one color.

[0061] The sub-pixels of the flexible display may be implemented by semiconductor light-emitting elements. In the present invention, as one type of semiconductor light-emitting element that converts current into light, a light-emitting diode (LED) is exemplified. The light-emitting diode is formed in a small size so that it can be used as a sub-pixel even in the second state.

[0062] Hereinafter, with reference to the drawings, a flexible display implemented using the light-emitting diode will be described in detail.

[0063] Figure 2 is Figure 1 a partial enlarged view of part A.

[0064] Figure 3a and Figure 3b are cross-sectional views taken along line B-B and line C-C of Figure 2 .

[0065] Figure 4 is a conceptual diagram showing a flip-chip type semiconductor light-emitting element of FIG. 3.

[0066] Figures 5a to 5c is a conceptual diagram showing various ways of implementing colors related to a flip-chip type semiconductor light-emitting element.

[0067] As Figure 2 , Figure 3a and Figure 3b shown, as a display device 100 using a semiconductor light-emitting element, a display device 100 using a passive matrix (PM) type semiconductor light-emitting element is exemplified. However, the examples described below are also applicable to an active matrix (AM) type semiconductor light-emitting element.

[0068] As Figure 2 shown, Figure 1 the display device 100 shown includes a substrate 110, a first electrode 120, a conductive adhesive layer 130, a second electrode 140, and at least one semiconductor light-emitting element 150.

[0069] The substrate 110 may be a flexible substrate. For example, the substrate 110 may include glass or polyimide (PI) to implement a flexible display device. In addition, any material such as PEN (Polyethylene Naphthalate) or PET (Polyethylene Terephthalate) may be used as long as it has insulation and flexibility. Additionally, the substrate 110 may be made of either a transparent material or an opaque material.

[0070] The substrate 110 may be a wiring substrate for configuring the first electrode 120. Accordingly, the first electrode 120 may be located on the substrate 110.

[0071] As Figure 3a shown, the insulating layer 160 may be disposed on the substrate 110 where the first electrode 120 is located, and an auxiliary electrode 170 may be provided on the insulating layer 160. In this case, the state where the insulating layer 160 is laminated on the substrate 110 may form a wiring substrate. More specifically, the insulating layer 160 is made of a material having insulation and flexibility such as polyimide (PI), PET, or PEN, and may be formed integrally with the substrate 110 to form a single substrate.

[0072] The auxiliary electrode 170 is an electrode that electrically connects the first electrode 120 and the semiconductor light-emitting element 150. It is located on the insulating layer 160 and is disposed corresponding to the position of the first electrode 120. For example, the auxiliary electrode 170 has a dot shape and may be electrically connected to the first electrode 120 through an electrode hole 171 that penetrates the insulating layer 160. The electrode hole 171 may be formed by filling a through hole with a conductive material.

[0073] As Figure 2 or Figure 3a shown, a conductive adhesive layer 130 is formed on one surface of the insulating layer 160, but the present invention is not necessarily limited thereto. For example, a layer that performs a specific function may be formed between the insulating layer 160 and the conductive adhesive layer 130, or a structure may be adopted in which the conductive adhesive layer 130 is disposed on the substrate 110 without the insulating layer 160. In the structure where the conductive adhesive layer 130 is disposed on the substrate 110, the conductive adhesive layer 130 may be used as an insulating layer.

[0074] The conductive adhesive layer 130 may be a layer having adhesiveness and conductivity. For this purpose, a conductive substance and an adhesive substance may be mixed in the conductive adhesive layer 130. Additionally, the conductive adhesive layer 130 has flexibility, thereby realizing a flexible function in the display device.

[0075] As an example of this, the conductive adhesive layer 130 may be an anisotropic conductive film (ACF), an anisotropic conductive paste, a solution containing conductive particles, or the like. The conductive adhesive layer 130 may be configured to allow electrical connection to each other in the Z direction through the thickness, and to have electrical insulation in the horizontal X-Y direction. Therefore, the conductive adhesive layer 130 may be named a Z-axis conductive layer (however, hereinafter referred to as "conductive adhesive layer").

[0076] The anisotropic conductive film is a film in which an anisotropic conductive medium is mixed in an insulating substrate member. When heat and pressure are applied, only a specific portion becomes conductive due to the anisotropic conductive medium. Hereinafter, the application of heat and pressure to the anisotropic conductive film will be described, but in order to make a local portion of the anisotropic conductive film conductive, other methods may also be applied. The above other methods may be, for example, applying only any one of the heat and pressure or UV curing.

[0077] In addition, the anisotropic conductive medium may be, for example, a conductive sphere or a conductive particle. For example, the anisotropic conductive film is a film in which conductive spheres are mixed in an insulating substrate member. When heat and pressure are applied, only a specific portion becomes conductive due to the conductive spheres. The anisotropic conductive film may be in a state containing a plurality of particles in which a core of a conductive material is covered with an insulating film of a polymer material. In this case, the insulating film of the portion to which heat and pressure are applied is broken, and thus conductivity is obtained through the core. At this time, the shape of the core may be deformed to form a layer in contact with each other in the thickness direction of the film. As a more specific example, heat and pressure are applied to the entire anisotropic conductive film, and due to the height difference of the objects adhered through the anisotropic conductive film, electrical connection in the Z-axis direction is partially formed.

[0078] As another example, the anisotropic conductive film may be in a state containing a plurality of particles in which a conductive material is covered on an insulating core. In this case, the portion to which heat and pressure are applied becomes conductive in the thickness direction of the film due to the deformation (pressing and pasting) of the conductive material. As still another example, it may be a form in which the conductive material penetrates the insulating substrate member in the Z-axis direction and has conductivity in the thickness direction of the film. In this case, the conductive material may have a sharp end.

[0079] The anisotropic conductive film may be a fixed array anisotropic conductive film (fixed array ACF) configured such that conductive spheres are inserted into one surface of an insulating substrate member. More specifically, the insulating substrate member is formed of an adhesive material, and the conductive spheres are concentratedly disposed at the bottom of the insulating substrate member. When heat and pressure are applied to the substrate member, it deforms together with the conductive spheres and has conductivity in the vertical direction.

[0080] However, the present invention is not necessarily limited thereto. The anisotropic conductive film may also be in a form in which conductive spheres are randomly mixed into an insulating substrate member, or may be in a form configured with a plurality of layers and having conductive spheres disposed in any one layer (double-ACF), etc.

[0081] The anisotropic conductive paste is a combined form of a paste and conductive spheres, and may be a paste in which conductive spheres are mixed in a substrate material having insulation and adhesiveness. In addition, the solution containing conductive particles may be a solution in the form of containing conductive (particle) grains or nano particles.

[0082] Refer again to Figure 3a , the second electrode 140 is spaced apart from the auxiliary electrode 170 and is located on the insulating layer 160. That is, the conductive adhesive layer 130 is disposed on the insulating layer 160 where the auxiliary electrode 170 and the second electrode 140 are located.

[0083] After the conductive adhesive layer 130 is formed in a state where the auxiliary electrode 170 and the second electrode 140 are located on the insulating layer 160, when the semiconductor light-emitting element 150 is connected in a flip-chip form by applying heat and pressure, the semiconductor light-emitting element 150 is electrically connected to the first electrode 120 and the second electrode 140.

[0084] Refer to Figure 4 , the semiconductor light-emitting element may be a light-emitting element of a flip chip type.

[0085] For example, the semiconductor light-emitting element includes a p-type electrode 156, a p-type semiconductor layer 155 on which the p-type electrode 156 is formed, an active layer 154 formed on the p-type semiconductor layer 155, an n-type semiconductor layer 153 formed on the active layer 154, and an n-type electrode 152 disposed horizontally spaced apart from the p-type electrode 156 on the n-type semiconductor layer 153. In this case, the p-type electrode 156 may be electrically connected to the auxiliary electrode 170 shown in FIG. 3 through the conductive adhesive layer 130, and the n-type electrode 152 may be electrically connected to the second electrode 140.

[0086] Refer again to Figure 2 , Figure 3a and Figure 3b, the auxiliary electrode 170 is formed to be longer in one direction such that one auxiliary electrode can be electrically connected to a plurality of semiconductor light-emitting elements 150. For example, the p-type electrodes of the semiconductor light-emitting elements on the left and right sides centered on the auxiliary electrode can be electrically connected to one auxiliary electrode.

[0087] More specifically, the semiconductor light-emitting elements 150 are pressed into the interior of the conductive adhesive layer 130 by heat and pressure. As a result, only the portions between the p-type electrode 156 of the semiconductor light-emitting element 150 and the auxiliary electrode 170 and between the n-type electrode 152 of the semiconductor light-emitting element 150 and the second electrode 140 are conductive, while the remaining portions do not have the semiconductor light-emitting elements pressed in and thus are not conductive. As described above, the conductive adhesive layer 130 not only binds the semiconductor light-emitting element 150 and the auxiliary electrode 170 and the semiconductor light-emitting element 150 and the second electrode 140 to each other, but also forms an electrical connection.

[0088] In addition, a plurality of semiconductor light-emitting elements 150 constitute a light-emitting element array, and a phosphor layer 180 is formed on the light-emitting element array.

[0089] The light-emitting element array may include a plurality of semiconductor light-emitting elements having different self-luminance values. Each semiconductor light-emitting element 150 constitutes a unit pixel and is electrically connected to the first electrode 120. For example, there may be a plurality of first electrodes 120, and the semiconductor light-emitting elements are arranged in a column, and the semiconductor light-emitting elements in each column can be electrically connected to any one of the plurality of first electrodes.

[0090] In addition, since the semiconductor light-emitting elements are connected in a flip-chip form, semiconductor light-emitting elements grown on a transparent dielectric substrate can be used. In addition, the semiconductor light-emitting elements may be nitride semiconductor light-emitting elements, for example. Since the semiconductor light-emitting element 150 has excellent brightness, even a small size can constitute a single unit pixel.

[0091] As shown in FIG. 3, a partition wall 190 may be formed between the semiconductor light-emitting elements 150. In this case, the partition wall 190 can be used to separate individual unit pixels from each other and can be formed integrally with the conductive adhesive layer 130. For example, by inserting the semiconductor light-emitting element 150 into an anisotropic conductive film, the base member of the anisotropic conductive film can form the partition wall 190.

[0092] In addition, when the base member of the anisotropic conductive film is black, the partition wall 190 can have reflective properties and increase the contrast even without a separate black insulator.

[0093] As another example, a reflective partition wall may be additionally provided as the partition wall 190. In this case, the partition wall 190 may include a black or white insulator according to the purpose of the display device. When using a partition wall with a white insulator, it can have the effect of improving reflectivity, and when using a partition wall with a black insulator, it can have reflective properties and increase contrast.

[0094] The phosphor layer 180 may be located on the outer surface of the semiconductor light-emitting element 150. For example, the semiconductor light-emitting element 150 is a blue semiconductor light-emitting element that emits blue B light, and the phosphor layer 180 performs the function of converting the blue B light into the color of a unit pixel. The phosphor layer 180 may be a red phosphor 181 or a green phosphor 182 that constitutes a single pixel.

[0095] That is, at the position where a unit pixel of red is formed, a red phosphor 181 capable of converting blue light into red R light may be laminated on the blue semiconductor light-emitting element, and at the position where a unit pixel of green is formed, a green phosphor 182 capable of converting blue light into green G light may be laminated on the blue semiconductor light-emitting element. In addition, only the blue semiconductor light-emitting element may be used alone in the part where a unit pixel of blue is formed. In this case, unit pixels of red R, green G, and blue B may form one pixel. More specifically, phosphors of one color may be laminated along each line of the first electrode 120. Therefore, in the first electrode 120, one line may be an electrode that controls one color. That is, red R, green G, and blue B may be arranged in sequence along the second electrode 140, whereby a unit pixel can be realized.

[0096] However, the present invention is not necessarily limited thereto, but unit pixels of red R, green G, and blue B may be realized by a combination of the semiconductor light-emitting element 150 and quantum dots (QDs) instead of phosphors.

[0097] In addition, in order to improve contrast, a black matrix 191 may be disposed between the respective phosphor layers. That is, such a black matrix 191 can improve the contrast between light and dark.

[0098] However, the present invention is not necessarily limited thereto, but other structures for realizing blue, red, and green may be used.

[0099] Referring to Figure 5a , each semiconductor light-emitting element 150 may use gallium nitride (GaN) as the main material and simultaneously add indium (In) and / or aluminum (Al) to realize a high-power light-emitting element that emits various lights including blue.

[0100] In this case, the semiconductor light-emitting element 150 can be a red, green, and blue semiconductor light-emitting element to form sub-pixels respectively. For example, the red, green, and blue semiconductor light-emitting elements R, G, and B can be alternately arranged, and the red (Red), green (Green), and blue (Blue) sub-pixels form a pixel through the red, green, and blue semiconductor light-emitting elements, thereby enabling full-color display.

[0101] Referring to Figure 5b , the semiconductor light-emitting element 150a can include a white light-emitting element W in which a yellow phosphor layer is provided for each individual element. In this case, in order to form a sub-pixel, a red phosphor layer 181, a green phosphor layer 182, and a blue phosphor layer 183 can be provided on the white light-emitting element W. In addition, by using color filters that repeat red, green, and blue on such a white light-emitting element W, a sub-pixel can be formed.

[0102] Referring to Figure 5c , a structure in which a red phosphor layer 184, a green phosphor layer 185, and a blue phosphor layer 186 are provided on the ultraviolet light-emitting element 150b can also be adopted. As described above, the semiconductor light-emitting element can be used in the entire region from visible light to ultraviolet light UV, and can be extended to a form of a semiconductor light-emitting element that can use ultraviolet light UV as an excitation source for the upper phosphor.

[0103] Referring to this example again, the semiconductor light-emitting element is located on the conductive adhesive layer, thereby constituting a sub-pixel in the display device. Since the semiconductor light-emitting element has excellent brightness, even a small size can constitute a single sub-pixel.

[0104] The size of the single semiconductor light-emitting element 150 as described above can be, for example, a length of one side of 80 μm or less, and can be a rectangular or square element. In the case of a rectangle, it can have a size of 20X80 μm or less.

[0105] In addition, even if a square semiconductor light-emitting element 150 with a side length of 10 μm is used as a sub-pixel, it will exhibit sufficient brightness to constitute a display device.

[0106] Therefore, for example, when the size of the sub-pixel is a rectangular pixel with one side of 600 μm and the other side of 300 μm, the distance between the semiconductor light-emitting elements is relatively large enough.

[0107] Therefore, in this case, a flexible display device with high image quality above HD image quality can be realized.

[0108] Figure 6It is a flowchart showing a method of manufacturing a display device including a semiconductor light-emitting element that emits red (R), green (G), and blue (B) light.

[0109] Figure 1 FIGS. 4 to 5 relate to the display device after the semiconductor light-emitting element is assembled to the wiring substrate. Then Figure 6 Specifically, it shows the process of manufacturing a display device having one unit pixel by transferring sub-pixels of RGB respectively.

[0110] In addition, as Figure 6 shown, in order to obtain the display device of the present invention, first, the step of transferring the semiconductor light-emitting element to the assembly substrate and the transfer substrate to be arranged on the wiring substrate is performed.

[0111] The step of assembling the semiconductor light-emitting element to the assembly substrate is specifically a self-assembly method using an electric field and a magnetic field, which will be described later.

[0112] Figure 6 The TEMPLATE shown refers to the assembly substrate.

[0113] According to Figure 6 the manufacturing method shown, three types of assembly substrates and three types of transfer substrates are required to manufacture a display device including a RED chip, a GREEN chip, and a BLUE chip.

[0114] Specifically, the assembly substrate may include a RED assembly substrate for assembling a RED semiconductor light-emitting element, a GREEN assembly substrate for assembling a GREEN semiconductor light-emitting element, and a BLUE assembly substrate for assembling a BLUE semiconductor light-emitting element.

[0115] In addition, the above manufacturing method can generally be divided into the step (S610) of assembling the semiconductor light-emitting element to the assembly substrate (TEMPLATE), the step (S620) such as stamping of transferring the semiconductor light-emitting element to the transfer substrate, and the step (S630) of transferring the semiconductor light-emitting element to the wiring substrate capable of realizing Active Matrix driving.

[0116] First, the step (S610) of assembling the semiconductor light-emitting element to the assembly substrate includes the step of assembling the semiconductor light-emitting elements that emit various colors of light to the corresponding assembly substrates. For example, the first semiconductor light-emitting element that emits light of the first color is assembled to the first assembly substrate, and the second semiconductor light-emitting element that emits light of the second color different from the first color is assembled to the second assembly substrate.

[0117] Thereafter, the semiconductor light-emitting elements assembled to the respective above-described assembly substrates are transferred to different transfer substrates (S620). That is, the first semiconductor light-emitting element assembled to the first assembly substrate can be transferred to the first transfer substrate, and the second semiconductor light-emitting element assembled to the second assembly substrate can be transferred to the second transfer substrate.

[0118] Based on Figure 6 description, the transfer step (S620) may include: a step of pressing a RED transfer substrate (stamped (R)) against the RED assembly substrate to transfer the RED semiconductor light-emitting element from the RED assembly substrate to the RED transfer substrate (stamped (R)); a step of pressing a GREEN transfer substrate (stamped (G)) against the GREEN assembly substrate to transfer the GREEN semiconductor light-emitting element from the GREEN assembly substrate to the GREEN transfer substrate (stamped (G)); and a step of pressing a BLUE transfer substrate (stamped (B)) against the BLUE assembly substrate to transfer the BLUE semiconductor light-emitting element from the BLUE assembly substrate to the BLUE transfer substrate (stamped (B)).

[0119] Finally, a process of pressing each of the above-described transfer substrates against a wiring substrate is performed so that the RED semiconductor light-emitting element, the GREEN semiconductor light-emitting element, and the BLUE semiconductor light-emitting element are transferred to the wiring substrate (S630).

[0120] In order to obtain a large-area display device, the process of transferring the semiconductor light-emitting elements from the transfer substrate to the wiring substrate can be performed multiple times. That is, multiple tiling transfers can be performed so that each transfer process is carried out at a predetermined position on a wiring substrate.

[0121] Conversely, it can also be different from Figure 6 the method shown, and three assembly substrates and one identical transfer substrate are used to transfer the semiconductor light-emitting elements corresponding to each of RED, GREEN, and BLUE to the wiring substrate.

[0122] For example, the step of transferring the semiconductor light-emitting elements assembled to the three assembly substrates to the wiring substrate can be performed by transferring the semiconductor light-emitting elements assembled to each assembly substrate to one transfer substrate (RGB integrated stamp), and then pressing the transfer substrate together with the wiring substrate so that the three semiconductor light-emitting elements can all be transferred to the wiring substrate.

[0123] Alternatively, an assembly substrate and a transfer substrate can also be used to transfer semiconductor light-emitting elements corresponding to each of RED, GREEN, and BLUE onto a wiring substrate. In this case, during self-assembly, a process is performed in which semiconductor light-emitting elements corresponding to each of RED, GREEN, and BLUE are assembled onto one assembly substrate and then transferred onto the transfer substrate and the wiring substrate together.

[0124] On the other hand, for Figure 6 the detailed steps included in each of the steps shown, in view of the overall spirit of this specification, deleting or changing some steps at a level understandable by those skilled in the art also falls within the scope of other rights protected by the present invention.

[0125] Figure 7 FIG. is a diagram showing an embodiment of a method of assembling semiconductor light-emitting elements onto a substrate by a self-assembly method.

[0126] In addition, Figure 8 is Figure 7 an enlarged view of part D of

[0127] In Figure 7 and Figure 8 examples of assembling semiconductor light-emitting elements onto a substrate by a self-assembly method using an electromagnetic field will be briefly described.

[0128] Referring to Figure 7 and Figure 8 , the semiconductor light-emitting element 150 can be placed into a chamber 230 filled with a fluid 220.

[0129] After that, the assembly substrate 210 can be disposed on the chamber 230. According to an embodiment, the assembly substrate 210 can also be placed into the chamber 230.

[0130] A pair of electrodes 213, 214 corresponding to each semiconductor light-emitting element 150 to be assembled can be formed on the assembly substrate 210. The electrodes 213, 214 can be implemented as transparent electrodes (ITO), or other common materials can be used for implementation. The electrodes 213, 214 correspond to an electric field generated when a voltage is applied, thereby stably fixing the semiconductor light-emitting element 150 in contact with the assembly grooves 211, 212 as an assembly electrode.

[0131] Specifically, an alternating voltage can be applied to the electrodes 213 and 214, and the semiconductor light-emitting element 150 floating around the electrodes 213 and 214 can have polarity due to dielectric polarization. Additionally, for a semiconductor light-emitting element with dielectric polarization, it may move or be fixed in a specific direction due to the non-uniform electric field formed around the electrodes 213 and 214. This is called dielectrophoresis. In the self-assembly process of the present invention, the semiconductor light-emitting element 150 can be stably fixed to the assembly grooves 211 and 212 by using this dielectrophoresis.

[0132] In addition, the assembly grooves may include: a first assembly groove 211 for a semiconductor light-emitting element for illumination; and a second assembly groove 212 for a semiconductor light-emitting element for alignment. The main purpose of the alignment assembly groove 212 is alignment rather than to achieve a display pixel, so it can be formed in a number less than that of the first assembly groove. For example, when 100 first assembly grooves 211 are formed, one second assembly groove 212 can be formed, or more can be formed. However, in the process of transferring the semiconductor light-emitting element 150 assembled into the second assembly groove 212 to the final wiring substrate, the minimum number for alignment needs to be satisfied. For example, three or more second assembly grooves 212 can be formed on the assembly substrate. Since one or two assembly grooves can only be defined as a point or line area, a two-dimensional area, that is, for alignment, can be specified by three or more assembly grooves.

[0133] In addition, the diameter of the second assembly groove 212 can be formed to be smaller than the diameter of the first assembly groove 211. Generally, when the diameter of the assembly groove is small and similar to the size of the semiconductor light-emitting element, the time required to assemble the semiconductor light-emitting element increases. However, since the number of the second assembly grooves 212 is very small compared to the number of the first assembly grooves 211, the time for the semiconductor light-emitting element 150 to be assembled into the second assembly groove 212 will not significantly affect the time for all semiconductor light-emitting elements to be assembled onto the assembly substrate 210.

[0134] In addition, the interval between the assembly electrodes 213 and 214 is formed to be smaller than the width of the semiconductor light-emitting element 150 and the diameter of the assembly grooves 211 and 212, for example, so as to more precisely fix the assembly position of the semiconductor light-emitting element 150 using the electric field.

[0135] In addition, an insulating layer 215 is formed on the assembled electrodes 213 and 214, so as to protect the electrodes 213 and 214 from the influence of the fluid 220 and prevent the leakage of the current flowing through the assembled electrodes 213 and 214. For example, the insulating layer 215 can be formed of an inorganic insulator such as silicon dioxide or aluminum oxide, or an organic insulator, as a single layer or multiple layers. In addition, the insulating layer 215 can have a minimum thickness for preventing damage to the assembled electrodes 213 and 214 when assembling the semiconductor light-emitting element 150, and can have a maximum thickness for stably assembling the semiconductor light-emitting element 150.

[0136] A partition wall 216 can be formed on the upper portion of the insulating layer 215. A partial area of the partition wall 216 can be located on the upper portions of the assembled electrodes 213 and 214, and the remaining area can be located on the upper portion of the assembled substrate 210.

[0137] For example, when manufacturing the assembled substrate 210, by removing a part of the partition wall formed on the entire upper portion of the insulating layer 215, the assembly grooves 211 and 212 for each semiconductor light-emitting element 150 to be bonded to the assembled substrate 210 can be formed.

[0138] As Figure 8 shown, an assembly groove 211 is formed in the assembled substrate 210, the semiconductor light-emitting element 150 is bonded into the assembly groove 211, and the surface where the assembly groove 211 is formed can be in contact with the fluid 220. The assembly groove 211 can guide the accurate assembly position of the semiconductor light-emitting element 150.

[0139] On the other hand, the assembly groove 211 can have a shape and size corresponding to the shape of the semiconductor light-emitting element 150 to be assembled. Therefore, it is possible to prevent other semiconductor light-emitting elements or a plurality of semiconductor light-emitting elements from being assembled into the assembly groove 211.

[0140] In addition, the depth of the assembly groove 211 can be formed to be less than the longitudinal height of the semiconductor light-emitting element 150. Thus, the semiconductor light-emitting element 150 can have a structure protruding between the partition walls 216 and can easily contact the protruding portion of the transfer substrate during the transfer process after assembly.

[0141] In addition, as Figure 7As shown, after configuring and assembling the substrate 210, the assembling device 240 including a magnetic body can move along the assembling substrate 210. The assembling device 240 can move in a state of being in contact with the assembling substrate 210 to maximize the area affected by the magnetic field in the fluid 220. For example, the assembling device 240 can include a plurality of magnetic bodies, or can also include a magnetic body having a size corresponding to the assembling substrate 210. In this case, the moving distance of the assembling device 240 can also be limited within a predetermined range.

[0142] Through the magnetic field generated by the assembling device 240, the semiconductor light-emitting element 150 in the chamber 230 can move towards the assembling device 240.

[0143] During the process of moving towards the assembling device 240, the semiconductor light-emitting element 150 can Figure 8 as shown enter the assembling groove 211 and come into contact with the assembling substrate 210.

[0144] On the other hand, the semiconductor light-emitting element 150 can be semiconductor light-emitting elements of the same shape made by the same process. However, the semiconductor light-emitting element assembled into Figure 7 the first assembling groove 211 as shown will be used as a semiconductor light-emitting element for illumination, and for the semiconductor light-emitting element assembled into the second assembling groove 212, it will be used as an alignment semiconductor light-emitting element.

[0145] In addition, as Figure 8 shown, the semiconductor light-emitting element 150 is a horizontal semiconductor light-emitting element, and can include a first conductivity type semiconductor layer 155, an active layer 154, a second conductivity type semiconductor layer 153, a first conductivity type electrode 156, and a second conductivity type electrode 152. In addition, magnetic layers can be included below the conductivity type electrodes 152, 156 to enable the self-assembly process. However, this is only an example, and the present invention is not limited thereto. Therefore, the present invention can be applied to all types of semiconductor light-emitting elements, whether they are vertical semiconductor light-emitting elements or horizontal semiconductor light-emitting elements.

[0146] Furthermore, patterns or shapes for making the second conductivity type semiconductor layer 153 of the semiconductor light-emitting element 150 come into contact with the assembling substrate 210 can be formed in the assembling groove 211 and / or the semiconductor light-emitting element 150.

[0147] On the other hand, through the electric field generated by the assembling electrodes 213, 214 of the assembling substrate 210, the phenomenon that the semiconductor light-emitting element 150 in contact with the assembling substrate 210 is separated due to the movement of the assembling device 240 can be prevented.

[0148] Therefore, through Figure 7 and Figure 8In the self-assembly method using an electromagnetic field shown, a plurality of semiconductor light-emitting elements 150 are simultaneously and multiply assembled onto the assembly substrate 210.

[0149] Figure 9 The figure is a flowchart showing the process in which a semiconductor light-emitting element for illumination and a semiconductor light-emitting element for alignment are assembled onto an assembly substrate by a self-assembly method.

[0150] As described above, in the self-assembly method using an electromagnetic field, semiconductor light-emitting elements (LEDs) are dispersedly present in a fluid, and the assembly substrate is disposed above a chamber filled with the fluid (S611).

[0151] In addition, the semiconductor light-emitting elements (LEDs) have the same structure formed by the same process, and assembly grooves for semiconductor light-emitting elements for illumination and assembly grooves for semiconductor light-emitting elements for alignment are pre-formed in the assembly substrate.

[0152] The semiconductor light-emitting elements (LEDs) may be horizontal semiconductor light-emitting elements and may have a non-directional circular structure to shorten the time for assembly into the assembly grooves.

[0153] In the self-assembly method, a plurality of semiconductor light-emitting elements are simultaneously and multiply assembled onto the assembly substrate in the fluid, and the semiconductor light-emitting elements for illumination and the semiconductor light-emitting elements for alignment are assembled into the assembly substrate at one time without an additional process (S612). By all the semiconductor light-emitting elements being assembled into the pre-formed assembly grooves in the assembly substrate, the assembly process is completed (S613).

[0154] Figure 10 The figure is a cross-sectional view of a semiconductor light-emitting element for illumination and a semiconductor light-emitting element for alignment assembled onto an assembly substrate by a self-assembly method.

[0155] As Figure 10 shown, assembly electrodes 213 and 214 are formed on the upper part of the assembly substrate 210, and an insulating layer 215 is coated thereon. In addition, the assembly grooves are defined by partition walls 216 partially formed on the insulating layer 215.

[0156] The semiconductor light-emitting elements assembled onto the assembly substrate 210 are generally divided into a semiconductor light-emitting element 1501 for illumination and a semiconductor light-emitting element 1502 for alignment. In addition, as Figure 10 shown, the width E of the first assembly groove in which the semiconductor light-emitting element 1501 for illumination is assembled may be greater than the width F of the second assembly groove in which the semiconductor light-emitting element 1502 for alignment is assembled.

[0157] By forming the width F of the second assembly groove to be smaller than the width E of the first assembly groove, it can be used for a more precise alignment purpose in the transfer step of a future semiconductor light-emitting element. For example, when the lateral length of the semiconductor light-emitting element is 50 μm, the width of the first assembly groove for assembling the semiconductor light-emitting element for lighting is formed to be 55 μm to provide a spacing difference of within approximately 5 μm, which is effective from the perspective of assembly time. This is because if the width of the assembly groove is almost the same as the lateral length of the semiconductor light-emitting element, the semiconductor light-emitting element can be assembled precisely, but considering the number of semiconductor light-emitting elements to be assembled, it may take a long time.

[0158] However, for the semiconductor light-emitting element for alignment, compared with the semiconductor light-emitting element for lighting, the number to be assembled is extremely small, and the impact of the individual assembly time on the overall assembly time is negligible. Therefore, the width of the assembly groove of the second assembly groove can be formed in the range of 51 μm to 53 μm for a more precise alignment purpose. That is, for the semiconductor light-emitting element assembled into the first assembly groove, the position within the first assembly groove can vary within 5 μm, but for the semiconductor light-emitting element assembled into the second assembly groove, the position within the second assembly groove varies within the range of 1 μm to 3 μm. Therefore, if the semiconductor light-emitting element assembled into the second assembly groove with its position more precisely controlled is used as an alignment index, precise transfer can also be achieved on the final wiring substrate.

[0159] However, in the present invention, the second assembly groove does not necessarily have to be smaller than the first assembly groove. The main reason for separately forming the assembly groove for alignment is to pre-judge the position deviation of the semiconductor light-emitting element that occurs during the transfer process after self-assembly, so as to minimize the alignment error of the semiconductor light-emitting element generated on the wiring substrate due to the position deviation. Therefore, the second assembly groove can also be equal to or larger than the first assembly groove. However, for more precise transfer, the second assembly groove is preferably smaller than the first assembly groove.

[0160] Figure 11 It is a cross-sectional view showing a method for manufacturing a display device using an assembly substrate and a wiring substrate according to the present invention.

[0161] Figure 11 (a) is a cross-sectional view showing the semiconductor light-emitting elements 1501 and 1502 assembled to the assembly substrate 210 and the transfer substrate 310 including the protrusion 311 being vertically aligned.

[0162] The semiconductor light-emitting elements formed on the assembly substrate 210 include a semiconductor light-emitting element 1501 for lighting and a semiconductor light-emitting element 1502 for alignment.

[0163] In addition, the convex portion 311 of the transfer substrate has an adhesive force sufficient to transfer the semiconductor light-emitting elements 1501 and 1502.

[0164] The convex portions 311 are formed at regular intervals corresponding to the arrangement intervals of the semiconductor light-emitting elements 1501 and 1502 of the assembly substrate 210. In addition, in order to accurately transfer the convex portions 311 to the semiconductor light-emitting elements 1501 and 1502, an alignment process may be performed.

[0165] The alignment process is performed by, for example, horizontally moving either the assembly substrate 210 or the transfer substrate 310 relative to the other, and then vertically moving it relative to the other. After that, the positions of the semiconductor light-emitting elements 1501 and 1502 of the assembly substrate 210 and the convex portions 311 of the transfer substrate corresponding to the semiconductor light-emitting elements are checked by a camera sensor or the like to see if they overlap. If they overlap, the semiconductor light-emitting elements are transferred corresponding to the convex portions 311, and the assembly substrate 210 is removed.

[0166] In addition, the assembly substrate 210 and the transfer substrate 310 may have alignment keys for alignment at corresponding positions. The alignment keys may, for example, be formed as the same concave-convex structure on each substrate so that the respective alignment keys can come into contact during the transfer process. However, the present invention is not limited thereto, and alignment keys of various structures conceivable by those skilled in the art may also be used.

[0167] On the other hand, if the number of semiconductor light-emitting elements assembled to the assembly substrate 210 is small, it is possible to separately determine whether the convex portions 311 of the transfer substrate 310 and the semiconductor light-emitting elements of the assembly substrate 210 overlap and perform the transfer as described above. However, if there are countless semiconductor light-emitting elements assembled to the assembly substrate 210, it takes a long inspection time to separately grasp the positions of the semiconductor light-emitting elements and the corresponding convex portions. Therefore, if alignment keys corresponding to the assembly substrate and the transfer substrate are formed, the transfer process of the semiconductor light-emitting elements can be performed only by confirming whether the alignment keys overlap.

[0168] Figure 11 (b) is a cross-sectional view after the semiconductor light-emitting elements 1501 and 1502 are transferred from the assembly substrate 210 to the transfer substrate 310.

[0169] As Figure 11 (b) shows, the semiconductor light-emitting elements 1501 and 1502 are stably transferred to the convex portions 311 of the transfer substrate 310.

[0170] The convex portion 311 can be a flexible film material such as PDMS (polydimethylsiloxane), having sufficient adhesiveness to contact and transfer the semiconductor light-emitting element. Additionally, the main material of the transfer substrate 310 that supports the convex portion 311 can include at least one of PET (Polyethylene terephthalate), PCE (Polycarboxylate Ether), and glass.

[0171] Figure 11 (c) is a cross-sectional view after the semiconductor light-emitting elements 1501 and 1502 are transferred from the convex portion 311 of the transfer substrate 310 to the wiring substrate 110.

[0172] The wiring substrate 110 can be formed with an electrode portion for electrically connecting the lighting semiconductor light-emitting element 1501 and the wiring substrate 110.

[0173] Conversely, an electrode portion will not be formed at the position of the transfer alignment semiconductor light-emitting element 1502. The transfer of the alignment semiconductor light-emitting element 1502 is for precise alignment during the process of transferring from the transfer substrate 310 to the wiring substrate 110 and will not be used as a light-emitting element after future wiring processes.

[0174] Additionally, at the position of the transfer alignment semiconductor light-emitting element 1502, an alignment mark 111 corresponding to the alignment semiconductor light-emitting element 1502 can be formed on the wiring substrate 110.

[0175] Additionally, in addition to the Align mark (alignment mark) 111, the wiring substrate 110 can also have alignment keys with the same structure at positions corresponding to the alignment keys of the transfer substrate 310.

[0176] Additionally, an adhesive layer for stably fixing the semiconductor light-emitting element 150 to the wiring substrate 110 can be provided on the wiring substrate 110. The adhesive layer is, for example, an anisotropic conductive adhesive layer and can simultaneously perform the transfer and wiring processes of the semiconductor light-emitting element 150.

[0177] Additionally, a reflective layer can be provided at the position of the wiring substrate 110 where the lighting semiconductor light-emitting element 1501 is to be transferred. When driving the lighting semiconductor light-emitting element 1501 in the future, the reflective layer can improve the external light extraction efficiency by reflecting the light emitted in the direction of the wiring substrate 110.

[0178] In addition, the arrangement intervals of the adhesive layer, electrode portion, and reflective layer that can be pre-formed on the wiring substrate need to be the same as the arrangement intervals of the semiconductor light-emitting elements located on the transfer substrate 310. Therefore, in order to accurately transfer the semiconductor light-emitting elements from the transfer substrate 310 to the wiring substrate 110, an alignment process can be performed.

[0179] The alignment process can be carried out by separately photographing the transfer substrate where the semiconductor light-emitting elements are located and the wiring substrate before transferring the semiconductor light-emitting elements with a camera, and designating the positions on the wiring substrate where the semiconductor light-emitting elements will be transferred.

[0180] In addition, for precise alignment, the wiring substrate 110 can be formed of a light-transmissive material. Therefore, the step of aligning the transfer substrate 310 and the wiring substrate 110 can be performed by arranging a camera on the back surface portion of the wiring substrate 110 that does not face the transfer substrate 310, and using the image captured by the camera.

[0181] Specifically, the transfer substrate 310 where the semiconductor light-emitting elements will be transferred and the front surface portion of the wiring substrate 110 of the semiconductor light-emitting elements are photographed by a camera provided on the back surface portion of the wiring substrate 110. After that, the regions of the semiconductor light-emitting elements corresponding to the transfer substrate 310 and the semiconductor light-emitting elements of the wiring substrate 110 can be overlapped by using the image captured by the camera, thereby setting the accurate transfer position.

[0182] On the other hand, if the number of semiconductor light-emitting elements transferred to the wiring substrate 110 is large, it takes a long inspection time to separately mark the regions corresponding to the semiconductor light-emitting elements on the wiring substrate 10 and determine whether they overlap with the semiconductor light-emitting elements. Therefore, if alignment keys corresponding to each other are formed on the transfer substrate and the wiring substrate, the transfer process of the semiconductor light-emitting elements can be performed only by confirming whether the alignment keys overlap.

[0183] However, there is a risk that the alignment keys formed on the transfer substrate are deformed through multiple transfer processes. This is because the transfer substrate uses a flexible material having adhesiveness to transfer semiconductor light-emitting elements, and may be stretched or deformed through repeated transfer processes.

[0184] Furthermore, the semiconductor light-emitting elements transferred to the transfer substrate may also have position deviations before and after transfer due to the physical properties of the transfer substrate.

[0185] On the other hand, with respect to the alignment keys pre-formed on the transfer substrate, the position deviation cannot be reflected. If transfer is ultimately performed based on the alignment keys, an alignment error of the semiconductor light-emitting elements corresponding to the position deviation will occur.

[0186] Therefore, if alignment keys pre-formed on the transfer substrate are used, the alignment error of the semiconductor light-emitting elements may deteriorate as the transfer process progresses.

[0187] Ultimately, in addition to the alignment keys formed on the transfer substrate, an alignment step using additional alignment marks that can minimize the alignment error of the semiconductor light-emitting elements may be required.

[0188] In the present invention, alignment semiconductor light-emitting elements are used as the alignment marks.

[0189] The alignment semiconductor light-emitting elements are assembled onto the assembly substrate during the self-assembly process, then transferred to the transfer substrate, and finally transferred to the wiring substrate.

[0190] During the process of transferring to the transfer substrate and transferring to the wiring substrate, the same transfer process as that of the illumination semiconductor light-emitting elements is performed. Even if an alignment error of the semiconductor light-emitting elements occurs before and after the transfer process, the alignment error can be reflected as it is. That is, if the alignment semiconductor light-emitting elements are used for alignment purposes, the influence of the alignment error that may occur in the step of transferring the semiconductor light-emitting elements to the wiring substrate can be ignored.

[0191] Therefore, the step of additionally using the alignment semiconductor light-emitting elements for alignment can be divided into the following steps. First, a first alignment step of overlapping the alignment keys formed at corresponding positions of the transfer substrate 310 and the wiring substrate 110 can be performed. Further, a second alignment step of overlapping the alignment semiconductor light-emitting elements 1502 on the transfer substrate 310 and pre-formed alignment marks 111 formed in the corresponding regions of the alignment semiconductor light-emitting elements on the wiring substrate 110 can be performed.

[0192] The approximate transfer position of the semiconductor light-emitting elements on the transfer substrate 310 transferred to the wiring substrate 110 can be confirmed through the first alignment step, and the semiconductor light-emitting elements on the transfer substrate 310 can be precisely transferred to the wiring substrate 110 through the second alignment step.

[0193] On the other hand, in Figure 11In the manufacture of the display device using the transfer substrate 310 shown, the transfer process is illustrated as being performed twice, but the present invention is not limited to the above number of transfers. For example, an additional transfer process can be performed to form a conductive electrode for a vertical semiconductor light-emitting element or to form a light extraction structure of the semiconductor light-emitting element, etc.

[0194] Figure 12 It is a top view showing the assembly substrate of the present invention and the semiconductor light-emitting element assembled to the assembly substrate.

[0195] As Figure 12 (a) shows that on the assembly substrate 210, there are provided: a first assembly groove 211 for a semiconductor light-emitting element for illumination; and a second assembly groove 212 for an alignment semiconductor light-emitting element. In addition, when transferring from the assembly substrate 210 to the transfer substrate, alignment keys 217 for accurate alignment are formed in advance.

[0196] Figure 12 (b) is a top view after the semiconductor light-emitting element is assembled to the Figure 12 assembly substrate of (a) by the self-assembly method using an electromagnetic field.

[0197] As described above, the semiconductor light-emitting element 1501 for illumination and the semiconductor light-emitting element 1502 for alignment are semiconductor light-emitting elements of the same structure formed by the same process, but in the future, the function of the semiconductor light-emitting element is determined according to the assembly grooves of the assembly substrate 210.

[0198] As Figure 12 (b) shows that the semiconductor light-emitting element 1501 for illumination is assembled to the first assembly groove and has a surplus space. On the contrary, the width of the second assembly groove is formed to be smaller than that of the first assembly groove. As Figure 12 (b) shows, the semiconductor light-emitting element 1502 for alignment can be assembled almost tightly with the second assembly groove.

[0199] Figure 13 It is a top view showing the transfer substrate of the present invention and the semiconductor light-emitting element transferred to the transfer substrate.

[0200] As Figure 13 (a) shows that on the transfer substrate 310, there can be provided alignment keys 317 having a structure corresponding to the alignment keys 217 formed in advance on the Figure 12 (b) assembly substrate 210. In addition, at positions corresponding to the semiconductor light-emitting elements for illumination and alignment assembled to the assembly substrate, respective protrusions 311, 312 are provided.

[0201] The widths of the protrusions 311, 312 can be formed to be larger than the semiconductor light-emitting element in order to stably bond and transfer the semiconductor light-emitting element.

[0202] Figure 13 (b) is a top view showing semiconductor light-emitting elements 1501 and 1502 transferred to a transfer substrate through the protrusions of Figure 13 (a).

[0203] Assembled into Figure 12 The semiconductor light-emitting elements on the assembly substrate of (b) are transferred to the transfer substrate 310 while maintaining the same pitch, as Figure 13 shown in (b).

[0204] However, regarding the alignment keys formed on the transfer substrate, they are formed of the same flexible material as the protrusions of the transfer substrate and may be deformed as the above transfer process is repeatedly performed.

[0205] Figure 14 is a top view showing a wiring substrate of the present invention and semiconductor light-emitting elements transferred to the wiring substrate.

[0206] As Figure 14 (a) shows, alignment keys 113 having a shape corresponding to the alignment keys 317 pre-formed on the transfer substrate 310 of Figure 12 (b) may be formed on the wiring substrate 110. The alignment keys 113 may include a concavo-convex structure.

[0207] In addition, alignment marks 111 may be formed at positions corresponding to the alignment semiconductor light-emitting elements of the transfer substrate.

[0208] Figure 14 (b) is a top view showing semiconductor light-emitting elements 1501 and 1502 transferred to Figure 14 (a) the wiring substrate 110.

[0209] As described above, the process of transferring the semiconductor light-emitting elements 1501 and 1502 to the wiring substrate 110 is as follows.

[0210] First, the alignment keys formed on the transfer substrate and the alignment keys formed on the wiring substrate are overlapped to confirm the approximate position.

[0211] The reason for not using the alignment keys to determine the final position transferred to the wiring substrate is that the alignment keys are pre-formed on the transfer substrate and cannot reflect the position deviation of the semiconductor light-emitting elements generated during the transfer process.

[0212] The positional deviation refers to the change in the average position of the semiconductor light-emitting element array before and after transfer due to the physical properties of the transfer substrate (stamping structure and flexible material). Therefore, when only the alignment keys are used for transfer, the positional deviation is reflected as it is, resulting in an alignment error of the semiconductor light-emitting elements on the wiring substrate. In addition, for the alignment keys, individual deformations occur with repeated transfer processes, and thus the alignment error may deteriorate further.

[0213] Therefore, when the approximate position of the semiconductor light-emitting elements of the transfer substrate to be transferred within the wiring substrate is determined using the alignment keys, the alignment semiconductor light-emitting elements on the transfer substrate are overlapped with the alignment marks 111 formed on the wiring substrate to determine the accurate transfer position.

[0214] The alignment semiconductor light-emitting elements have undergone the same transfer process as the surrounding semiconductor light-emitting elements, and the change in the average position of the semiconductor light-emitting element array before and after transfer is reflected as it is. Therefore, there is no alignment error caused by positional deviation before and after transfer.

[0215] Finally, when the above two alignment steps are performed, as Figure 14 (b) shows, the alignment semiconductor light-emitting elements 1502 are transferred to the alignment marks 111, and the illumination semiconductor light-emitting elements 1501 are accurately transferred while maintaining a specified interval difference from the alignment semiconductor light-emitting elements 1502.

[0216] Figure 15 is a top view showing the semiconductor light-emitting elements transferred to a partial area of the wiring substrate.

[0217] Figure 15 The area indicated by the dotted line in is the arrangement of the semiconductor light-emitting elements transferred from the transfer substrate of Figure 14 (b).

[0218] In order to obtain a large-area display device, the process of transferring semiconductor light-emitting elements from the transfer substrate to the wiring substrate can be performed multiple times.

[0219] For example, for the Figure 15 shown wiring substrate 110, four transfer processes are required to fill all areas within the wiring substrate 110 with semiconductor light-emitting elements.

[0220] Each transfer process needs to be precisely adjusted within the wiring substrate 110. As Figure 15 shown, precise transfer can be achieved through the alignment marks 111 and the alignment semiconductor light-emitting elements 1502 transferred to the upper part of the alignment marks.

[0221] Specifically, when the transfer substrate is overlapped with the wiring substrate 110 to transfer semiconductor light-emitting elements, first, it is determined whether the alignment keys 113 are overlapped. If it is determined that the alignment keys 113 are overlapped, the position is precisely adjusted so that the alignment marks 111 of the wiring substrate 110 and the alignment semiconductor light-emitting elements of the transfer substrate are overlapped, and then the illumination semiconductor light-emitting elements and the alignment semiconductor light-emitting elements are transferred to the wiring substrate 110.

[0222] Figure 15 The area shown by the dashed line in the figure is a top view after transfer by the above method, and the illumination semiconductor light-emitting elements 1501 and the alignment semiconductor light-emitting elements 1502 are transferred to the accurate positions of the wiring substrate 110.

[0223] In addition, the number of illumination semiconductor light-emitting elements transferred by the above single transfer can be significantly larger than the number of alignment semiconductor light-emitting elements. For example, the number of illumination semiconductor light-emitting elements per same area in the wiring substrate can be more than 100 times larger than the number of alignment semiconductor light-emitting elements.

[0224] Figure 16 is a top view after a wiring process is performed on the semiconductor light-emitting elements transferred to the wiring substrate.

[0225] As Figure 16 shown, the illumination semiconductor light-emitting elements 1501 can form wiring electrodes 120 and be electrically connected to the wiring substrate 110 so as to emit light of a specific color when driving the display device.

[0226] On the contrary, as Figure 16 shown, a dark film layer 183 can be selectively formed on the upper part of the position where the alignment semiconductor light-emitting elements are transferred on the wiring substrate 110. The dark film layer 183 is formed of a material having a low light transmittance. For example, the dark film layer 183 can be formed of black resin or black colored photoresist.

[0227] The dark film layer 183 is used to prevent light leakage from the alignment semiconductor light-emitting elements to the outside when driving the display device. This is because, even if the alignment semiconductor light-emitting elements are not electrically connected to the wiring substrate 110, the first light generated from the surrounding illumination semiconductor light-emitting elements 1501 is transmitted to the alignment semiconductor light-emitting elements, and thus the second light may be generated from the alignment semiconductor light-emitting elements.

[0228] The above description is only an exemplary description of the technical idea of the present invention, and those of ordinary skill in the art can make various modifications and deformations without departing from the essential characteristics of the present invention.

[0229] Therefore, the embodiments disclosed in the present invention are not used to limit the technical idea of the present invention, but for illustration, and the technical idea of the present invention is not limited by these embodiments.

[0230] The protection scope of the present invention shall be interpreted by the appended claims, and it should be interpreted that all technical ideas within the equivalent scope are included in the protection scope of the claims of the present invention.

Claims

1. A manufacturing method of a display device, characterized in that, The manufacturing method includes: The steps of assembling a plurality of semiconductor light-emitting elements into a first assembly groove and a second assembly groove smaller than the first assembly groove of an assembly substrate, using the semiconductor light-emitting elements assembled in the first assembly groove as lighting semiconductor light-emitting elements, and using the semiconductor light-emitting elements assembled in the second assembly groove as alignment semiconductor light-emitting elements; The step of transferring the semiconductor light-emitting elements assembled on the assembly substrate to a transfer substrate from the assembly substrate; and The step of transferring the semiconductor light-emitting elements transferred to the transfer substrate from the transfer substrate to a wiring substrate, and no electrode portion is formed at the position on the wiring substrate where the alignment semiconductor light-emitting elements are transferred. The steps of assembling the lighting semiconductor light-emitting elements into the first assembly groove and assembling the alignment semiconductor light-emitting elements into the second assembly groove respectively include: Performing self-assembly using an electric field and a magnetic field.

2. The manufacturing method of the display device according to claim 1, wherein The lighting semiconductor light-emitting elements and the alignment semiconductor light-emitting elements have the same structure formed by the same process.

3. The manufacturing method of the display device according to claim 2, wherein The step of assembling the lighting semiconductor light-emitting elements into the first assembly groove or the step of assembling the alignment semiconductor light-emitting elements into the second assembly groove further includes: The step of putting the semiconductor light-emitting elements into a fluid chamber; The step of disposing the assembly substrate on the top surface of the fluid chamber; The step of using an assembly device having a magnetic body to make the corresponding semiconductor light-emitting elements floating in the fluid chamber contact with the first assembly groove or the second assembly groove; and The step of assembling the corresponding semiconductor light-emitting elements into the first assembly groove or the second assembly groove based on the electric field applied by the assembly electrodes formed on the assembly substrate.

4. The manufacturing method of the display device according to claim 1, wherein The transfer substrate includes a plurality of protrusions, and the plurality of protrusions are formed at positions corresponding to the lighting semiconductor light-emitting elements assembled in the first assembly groove and positions corresponding to the alignment semiconductor light-emitting elements. The step of transferring the semiconductor light-emitting elements assembled on the assembly substrate to the transfer substrate from the assembly substrate includes: The step of overlapping the assembly substrate and the transfer substrate so that the protrusions and the semiconductor light-emitting elements overlap each other; The step of making the overlapping semiconductor light-emitting elements contact the protrusions to fix the semiconductor light-emitting elements; and The step of removing the assembly substrate.

5. The manufacturing method of the display device according to claim 1, wherein The assembly substrate and the transfer substrate are provided with alignment keys having the same concavo-convex structure for alignment at positions where the assembly substrate and the transfer substrate are arranged in a corresponding manner.

6. The manufacturing method of the display device according to claim 5, wherein The step of transferring a semiconductor light-emitting element assembled to the assembly substrate to the transfer substrate includes: The step of overlapping the alignment keys at positions where the assembly substrate and the transfer substrate are arranged in a corresponding manner.

7. The manufacturing method of a display device according to claim 1, wherein: The step of transferring the semiconductor light-emitting element transferred to the transfer substrate from the transfer substrate to the wiring substrate includes: The step of aligning the transfer substrate and the wiring substrate so that the semiconductor light-emitting element is disposed in a partial area of the wiring substrate corresponding to the semiconductor light-emitting element transferred to the transfer substrate; The step of fixing the semiconductor light-emitting element to the partial area of the wiring substrate corresponding to the semiconductor light-emitting element; and The step of removing the transfer substrate.

8. The manufacturing method of a display device according to claim 7, wherein: The wiring substrate is formed of a light-transmissive material, The step of aligning the transfer substrate and the wiring substrate is performed using an image captured by a camera disposed on the back surface of the wiring substrate.

9. The manufacturing method of a display device according to claim 8, wherein: The step of aligning the transfer substrate and the wiring substrate includes: The step of overlapping the area of the transfer substrate corresponding to the semiconductor light-emitting element and the partial area of the wiring substrate corresponding to the semiconductor light-emitting element using the image captured by the camera.

10. The manufacturing method of a display device according to claim 8, wherein: The transfer substrate and the wiring substrate are provided with alignment keys having the same concavo-convex structure for alignment at positions where the transfer substrate and the wiring substrate are arranged in a corresponding manner.

11. The manufacturing method of a display device according to claim 10, wherein: The step of aligning the transfer substrate and the wiring substrate includes: The step of positioning the alignment keys so that the alignment keys overlap each other; and The step of positioning the alignment semiconductor light-emitting element transferred to the transfer substrate to overlap with the alignment mark of the wiring substrate at a position corresponding to the alignment semiconductor light-emitting element.

12. The manufacturing method of a display device according to claim 1, wherein: After the step of transferring the semiconductor light-emitting element to the wiring substrate, it includes: The step of electrically connecting the lighting semiconductor light-emitting element to the wiring substrate by performing a wiring process.

13. The manufacturing method of the display device according to claim 12, characterized in that, It further includes: The step of coating a material with low light transmittance on the upper part of the alignment semiconductor light-emitting element.

14. The manufacturing method of a display device according to claim 1, wherein: The assembly substrate includes: A first assembly substrate, to which a first semiconductor light-emitting element that emits light of a first color when driving the display device is assembled; and A second assembly substrate, to which a second semiconductor light-emitting element that emits light of a second color different from the first color is assembled.

15. A display device, characterized in that, It includes: A wiring substrate; And A plurality of semiconductor light-emitting elements are located on the wiring substrate. The plurality of semiconductor light-emitting elements include a semiconductor light-emitting element for illumination and a semiconductor light-emitting element for alignment. The semiconductor light-emitting element for illumination and the semiconductor light-emitting element for alignment have the same shape and the same light-emitting color. The semiconductor light-emitting element for illumination is electrically connected to the wiring electrode of the wiring substrate. An electrode portion is not formed at the position of the wiring substrate where the semiconductor light-emitting element for alignment is transferred.

16. The display device according to claim 15, wherein the number of the semiconductor light-emitting elements for illumination per unit area of the wiring substrate is more than 100 times the number of the semiconductor light-emitting elements for alignment per unit area of the wiring substrate.

17. The display device according to claim 15, wherein the wiring substrate includes an alignment key having a concavo-convex structure.

18. The display device according to claim 15, wherein the semiconductor light-emitting element is a micro light-emitting element having a size in the micron unit.

19. The display device according to claim 15, wherein a dark film layer having a low light transmittance is provided on the top surface of the semiconductor light-emitting element for alignment.

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