Display device using light-emitting semiconductor devices and self-assembly method for multiple light-emitting semiconductor devices

Abstract

Display device which features: a substrate (261); several light-emitting semiconductor devices (250) arranged on the substrate (261); a first wiring electrode (281) and a second wiring electrode (282), each extending from the light-emitting semiconductor devices (250) to supply an electrical signal to the light-emitting semiconductor devices (250); several electrode pairs (261c, 311a, 312a, 311b, 312b, 311c, 312c) arranged on the substrate (261) to generate an electric field when an electric current is supplied, and which are provided with first and second electrode pairs formed on a side opposite the first and second wiring electrodes (281, 282) with respect to the light-emitting semiconductor devices (250); and a dielectric layer (261b) which is designed to cover the electrode pairs (261c, 311a, 312a, 311b, 312b, 311c, 312c), wherein the multiple electrode pairs (261c, 311a, 312a, 311b, 312b, 311c, 312c) are arranged parallel to each other along one direction.

Description

Background of the invention

[0001] The present disclosure relates to a display device using semiconductor light-emitting devices and self-assembly methods for a plurality of semiconductor light-emitting devices. Description of related technology

[0002] In recent years, in the field of display technology, liquid crystal displays (LCDs), organic light-emitting diode (OLED) displays, and micro-LED displays have competed to implement a large-area display.

[0003] However, there are problems such as slow response time, low efficiency of backlight generated light in the case of LCDs and there are disadvantages such as short lifespan as well as low efficiency in the case of OLEDs.

[0004] In contrast, when semiconductor light-emitting devices (micro-LEDs (µLEDs)) with a diameter or cross-sectional area of ​​100 micrometers or less are used in a display, the display can provide very high efficiency because it does not absorb light using a polarizing plate or the like. However, since a large-area display requires millions of semiconductor light-emitting devices, it faces the difficulty of transferring the devices compared to other technologies.

[0005] Transfer process technologies currently under development include pick-and-place, laser lift-off (LLO), self-assembly, and the like. Of these, the self-assembly process, which is a process in which the semiconductor light-emitting device self-assembles in a fluid, is the most advantageous method for realizing a large-scale display device.

[0006] In recent years, U.S. Patent No. 9,825,202 proposed a micro-LED structure suitable for self-assembly, but there has been no research into technologies for manufacturing a display by self-assembling micro-LEDs. Accordingly, the present disclosure proposes a new type of display device capable of self-assembling micro-LEDs and a manufacturing method therefor.

[0007] KR 10 2018 0 082 003 A describes a display device using a light-emitting semiconductor element and a manufacturing method therefor.

[0008] KR 10 2018 0 089 771 A describes a display device with a light-emitting semiconductor element.

[0009] US 2011 / 0 197 429 A1 describes magnetically driven simultaneous assembly for the integration of devices on substrates. Disclosure of the inventionTechnical problem

[0010] An object of the present disclosure is to provide a novel manufacturing method with high reliability in a large screen display using micro-sized semiconductor light-emitting devices.

[0011] Another object of the present disclosure is to provide a manufacturing method of a display in which the semiconductor light-emitting devices can be directly self-mounted on a wiring substrate.

[0012] Yet another object of the present disclosure is to provide a display manufacturing method capable of reducing a manufacturing time of a large screen display. Solution to the task

[0013] To achieve the above objects, the present disclosure can provide a display device according to claim 1, comprising: a substrate, a plurality of semiconductor light-emitting devices arranged on the substrate, a first wiring electrode and a second wiring electrode each extending from the semiconductor light-emitting devices to supply an electric signal to the semiconductor light-emitting devices, a plurality of electrode pairs arranged on the substrate to generate an electric field when an electric current is supplied, and provided with first and second electrodes formed on a side opposite to the first and second wiring electrodes with respect to the semiconductor light-emitting devices, and a dielectric layer formed to cover the electrode pairs,wherein the plurality of electrode pairs are arranged parallel to each other along a direction.,

[0014] According to one embodiment, each of the plurality of semiconductor light-emitting devices may be arranged to overlap with any one of the electrode pairs.

[0015] According to one embodiment, the plurality of semiconductor light-emitting devices may comprise a first semiconductor light-emitting device emitting a first color and a second semiconductor light-emitting device emitting a second color different from the first color, wherein the first and second semiconductor light-emitting devices are each arranged to overlap with mutually different electrode pairs.

[0016] According to one embodiment, a distance between adjacent first and second electrodes may be smaller than that between adjacent electrode pairs.

[0017] According to one embodiment, a width of each electrode pair may be larger than that of the semiconductor light-emitting device.

[0018] According to one embodiment, the display device may further comprise a thin film transistor arranged on the same plane as the substrate.

[0019] According to one embodiment, the plurality of semiconductor light-emitting devices may be arranged on the dielectric layer, and the first wiring electrode and the second wiring electrode are arranged on each of the plurality of semiconductor light-emitting devices such that the dielectric layer is interposed between the plurality of semiconductor light-emitting devices and the plurality of electrode pairs, and the plurality of semiconductor light-emitting devices are interposed between the first and second wiring electrodes and the dielectric layer.

[0020] According to one embodiment, widths of the plurality of electrode pairs may be larger than widths of the first and second wiring electrodes.

[0021] According to one embodiment, the plurality of electrode pairs may provide a magnetic force to establish the plurality of semiconductor light-emitting devices on the substrate and may not provide the electrical signal to generate an image of the display device.

[0022] According to one embodiment, adjacent pairs of the plurality of electrode pairs may be separated by a gap, and the plurality of semiconductor light-emitting devices may be arranged directly above the gap.

[0023] Furthermore, the present disclosure can provide a self-assembly method of a semiconductor light-emitting device according to claim 12, and the method can include: transferring a substrate having a mounting region and a non-mounting region to a mounting position, placing the semiconductor light-emitting devices in a fluid chamber, applying a magnetic force to the semiconductor light-emitting devices to move the semiconductor light-emitting devices in the fluid chamber along a direction, and applying a voltage to a plurality of pairs of electrodes arranged on the substrate to guide the semiconductor light-emitting devices to predetermined positions to allow the semiconductor light-emitting devices to be placed at the predetermined positions of the mounting region during the movement of the semiconductor light-emitting devices,wherein the plurality of electrode pairs are arranged on the mounting area of ​​the substrate and bus electrodes electrically connected to the plurality of electrode pairs are arranged in the non-mounting area.,

[0024] According to one embodiment, applying a voltage to a plurality of electrode pairs arranged on the substrate by an external power source connected to the bus electrodes may apply a voltage to the plurality of electrode pairs.

[0025] According to one embodiment, a first bus electrode and a second bus electrode may be arranged on the substrate, and one electrode of the electrode pair may be electrically connected to the first bus electrode and another electrode of the electrode pair may be electrically connected to the second bus electrode.

[0026] According to one embodiment, applying a magnetic force to the semiconductor light-emitting devices and guiding the semiconductor light-emitting devices to the predetermined positions may be performed at least once while placing the semiconductor light-emitting devices emitting the first color in the fluid chamber, and at least once while placing the semiconductor light-emitting devices emitting the second color different from the first color in the fluid chamber.

[0027] According to one embodiment, guiding the semiconductor light-emitting devices to the predetermined positions may apply a voltage to a different pair of electrodes for each type of semiconductor light-emitting devices placed in the fluid chamber to guide the semiconductor light-emitting devices to different pairs of electrodes depending on the type of semiconductor light-emitting devices.

[0028] According to one embodiment, the substrate may comprise a plurality of mounting regions, and the plurality of electrode pairs arranged in each of the plurality of mounting regions may be electrically connected from the bus electrodes to the same bus electrode.

[0029] According to one embodiment, the present disclosure may further comprise dividing the substrate for each mounting region.

[0030] According to one embodiment, the plurality of electrode pairs may apply the magnetic force to establish the plurality of semiconductor light-emitting devices on the substrate and may not provide an electrical signal to operate the plurality of semiconductor light-emitting devices.

[0031] According to one embodiment, adjacent pairs of the plurality of electrode pairs may be separated by a gap, and the plurality of semiconductor light-emitting devices may be arranged directly above the gap.

[0032] According to the present disclosure having the above configuration, a large number of semiconductor light-emitting devices can be simultaneously mounted in a display device in which individual pixels are formed with micro light-emitting diodes.

[0033] As described above, according to the present disclosure, a large number of semiconductor light-emitting devices can be deposited on a wafer with a small size as pixels and then directly transferred to a large-area substrate. Furthermore, since the mesa of the semiconductor light-emitting devices is formed on a substrate, it is possible to directly transfer the semiconductor light-emitting devices to a wiring substrate using a temporary substrate. This makes it possible to manufacture a large-area display device at low cost.

[0034] Furthermore, according to the manufacturing method and apparatus of the present disclosure, semiconductor light-emitting devices can be transferred to precise positions using a magnetic field and an electric field in a solution simultaneously, thereby enabling low-cost, high-efficiency, and high-speed transfer implementation.

[0035] Furthermore, since the assembly is performed by an electric field, selective assembly is enabled by a selective electrical application without any additional device or process. Consequently, red, green, and blue micro-LEDs can be selectively mounted at desired positions. Short description of the drawings

[0036] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings: Fig. 1 is a conceptual view illustrating a display device using a semiconductor light-emitting device according to an embodiment of the present disclosure. Fig. Fig. 2 is a partially enlarged view showing a portion “A” of the display device in Fig. 1 shows. Fig. 3 is an enlarged view showing a semiconductor light-emitting device in Fig. 2 shows. Fig. Fig. 4 is an enlarged view showing another embodiment of the semiconductor light-emitting device in Fig. 2 shows. Fig. 5A to 5E are conceptual views for explaining a novel method for manufacturing the above semiconductor light-emitting device. Fig. 6 is a conceptual view showing an example of a self-assembly apparatus for semiconductor light-emitting devices according to the present disclosure. Fig. Figure 7 is a block diagram showing the self-assembly device in Fig. 6 shows. Fig. 8A to 8G are conceptual views showing a method for self-assembling semiconductor light-emitting devices using the self-assembly apparatus in Fig. Show 6. Fig. 9A to 9E are conceptual views showing a method of manufacturing a display device after self-assembling semiconductor light-emitting devices on a wiring substrate using the self-assembly apparatus of Fig. Show 6. Fig. 10 is a conceptual view showing pairs of electrodes arranged on a substrate. Fig. 11 is a conceptual view showing a state in which a pair of electrodes and a bus electrode are connected. Fig. 12 is a conceptual view showing a substrate having multiple mounting areas. Fig. 13 is a conceptual view showing the arrangement of semiconductor light-emitting devices and electrode pairs included in a display device according to the present disclosure. Fig. 14 is a cross-sectional view of a display device including a thin film transistor. Detailed description of the preferred embodiment

[0037] Hereinafter, the embodiments disclosed herein will be described in detail with reference to the accompanying drawings. The same or similar elements will be denoted by the same numerical references regardless of the numbers in the drawings, and their redundant description will be omitted. A suffix "module" and "unit" used for constituent elements disclosed in the following description is intended only for the convenience of describing the specification, and the suffix itself does not impart any particular meaning or function. In describing the present disclosure, when a detailed explanation for a related known function or construction is deemed unnecessarily obscuring the spirit of the present disclosure, such an explanation has been omitted but would be understood by those skilled in the art.It should also be noted that the accompanying drawings are presented merely to easily explain the concept of the invention and therefore should not be construed as limiting the technological concept disclosed herein by the accompanying drawings.

[0038] It is also understood that when an element, such as a layer, region, or substrate, is referred to as being "on" another element, it may be directly on the other element or an intermediate element may be interposed therebetween.

[0039] A display device disclosed herein may include a portable telephone, a smartphone, a laptop computer, a digital broadcast terminal, a personal digital assistant (PDA), a portable multimedia player (PMP), a navigation device, a slate PC, a tablet PC, an ultrabook, a digital TV, a digital signage system, a head-mounted display (HMD), a desktop computer, and the like. However, it would be readily understood by those skilled in the art that a configuration disclosed herein may be readily applicable to any display-capable device, even if a new product type is later developed.

[0040] Fig. 1 is a conceptual view illustrating a display device using a semiconductor light-emitting device according to an embodiment of the present disclosure, and Fig. Fig. 2 is a partially enlarged view showing a portion “A” of the display device in Fig. 1 shows, and Fig. 3 is an enlarged view showing a semiconductor light-emitting device in Fig. 2 shows, and Fig. Fig. 4 is an enlarged view showing another embodiment of the semiconductor light-emitting device in Fig. 2 shows.

[0041] As shown, information processed in the controller of the display device 100 may be displayed on a display module 140. A housing 101 in the shape of a closed loop surrounding an edge of the display module may form a bezel of the display device.

[0042] The display module 140 may include a panel 141 on which an image is displayed, and the panel 141 may include micro-sized semiconductor light-emitting devices 150 and a wiring substrate 110 on which the semiconductor light-emitting devices 150 are mounted.

[0043] Wiring lines may be formed on the wiring substrate 110 and connected to an n-electrode 152 and a p-electrode 156 of the semiconductor light-emitting device 150. This allows the semiconductor light-emitting device 150 to be provided as a self-emitting single pixel on the wiring substrate 110.

[0044] An image displayed on the panel 141 is visual information and is implemented by controlling the light emission of a sub-pixel arranged in a matrix form through the wiring lines.

[0045] According to the present invention, a micro-LED (light-emitting diode) is represented as a type of semiconductor light-emitting device 150 that converts electricity into light. The micro-LED may be a light-emitting diode formed with a small size of 100 micrometers or less. The semiconductor light-emitting device 150 may be provided with blue, red, and green emitting regions, respectively, to implement a sub-pixel by combining the light-emitting regions. In other words, a sub-pixel refers to a minimum unit for implementing a single color, and at least three micro-LEDs may be provided in the sub-pixel.

[0046] In particular, the semiconductor light-emitting device 150 may be configured to Fig. 3 be a vertical structure.

[0047] For example, the semiconductor light-emitting devices 150 may be implemented with a high-power light-emitting device that emits various lights, including blue, mainly using gallium nitride (GaN), and adding indium (In) and / or aluminum (Al) thereto.

[0048] The vertical semiconductor light-emitting device may include a p-electrode 156, a p-type semiconductor layer 155 formed with the p-electrode, 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 formed on the n-type semiconductor layer 153. In this case, the p-electrode 156 located at the bottom may be electrically connected to a p-electrode of the wiring substrate, and the n-electrode 152 located at the top may be electrically connected to an n-electrode on a top side of the semiconductor light-emitting device. The electrodes may be arranged in the up / down direction in the vertical semiconductor light-emitting device 150, thereby providing a great advantage of being able to reduce the chip size.

[0049] As another example, the semiconductor light-emitting device may be referred to Fig. 4 may be a flip-chip semiconductor light-emitting device.

[0050] For such an example, the semiconductor light-emitting device 250 may include a p-electrode 256, a p-type semiconductor layer 255 formed with the p-electrode 256, an active layer 254 formed on the p-type semiconductor layer 255, an n-type semiconductor layer 253 formed on the active layer 254, and an n-type electrode 252 arranged to be separated from the p-type electrode 256 in the horizontal direction on the n-type semiconductor layer 253. In this case, both the p-electrode 256 and the n-electrode 252 may be electrically connected to the p-electrode and the n-electrode of the wiring substrate at the bottom of the semiconductor light-emitting device.

[0051] The vertical semiconductor light-emitting device and the horizontal semiconductor light-emitting device may each be a green semiconductor light-emitting device, a blue semiconductor light-emitting device, or a red semiconductor light-emitting device. The green semiconductor light-emitting device and the blue semiconductor light-emitting device may be formed primarily of gallium nitride (GaN), and indium (In) and / or aluminum (Al) may be added thereto to implement a high-performance light-emitting device that emits green or blue light. For one such example, the semiconductor light-emitting device may be a gallium nitride thin film formed in various layers, such as n-GaN, p-GaN, and InGa. Specifically, the p-type semiconductor layer may be p-GaN, and the n-type semiconductor layer may be n-GaN.However, in the case of the red light-emitting semiconductor device, the p-type semiconductor layer may be p-GaAs and the n-type semiconductor layer may be n-GaAs.

[0052] Furthermore, a p-electrode side in the p-type semiconductor layer may be Mg-doped p-GaN, and an n-electrode side in the n-type semiconductor layer may be Si-doped GaN. In this case, the semiconductor light-emitting devices described above may be semiconductor light-emitting devices without an active layer.

[0053] Since the light emitting diode, on the other hand, refers to Fig. 1 to 4 is very small, the display panel can be arranged with self-emitting subpixels with a fine pitch, thereby implementing a high-quality display device.

[0054] In a display device using the above-described semiconductor light-emitting device of the present disclosure, a semiconductor light-emitting device grown on a wafer and formed by mesa and isolation is used as a single pixel. In this case, the micro-sized semiconductor light-emitting device 150 needs to be transferred to a predetermined position on the substrate of the display panel on a wafer. Pick and place is used as the transfer technology, but the success rate is low and it takes a lot of time. As another example, there is a technology for simultaneously transferring multiple devices using a stamper or a roller, but the yield is limited and not suitable for large-screen display.The present disclosure proposes a novel manufacturing method of a display device capable of solving the above problems and a manufacturing apparatus using the same.

[0055] For this purpose, a new manufacturing process for the display device is first described. Fig. 5A to 5E are conceptual views for explaining a novel method for manufacturing the above semiconductor light-emitting device.

[0056] This specification describes a display device using a passive matrix (PM) semiconductor light-emitting device.

[0057] However, an example described below may also be applicable to an active matrix (AM) semiconductor light-emitting device. Furthermore, a method using a horizontal semiconductor light-emitting device is described, but it is also applicable to a method for self-assembling a vertical semiconductor light-emitting device.

[0058] First, according to a manufacturing method, a first conductive semiconductor layer 253, an active layer 254 and a second conductive semiconductor layer 255 are each grown on a growth substrate 259.

[0059] When the first conductive semiconductor layer 253 is grown, next, an active layer 254 is grown on the first conductive semiconductor layer 253, and then the second conductive semiconductor layer 255 is grown on the active layer 254. As described above, when the first conductive semiconductor layer 253, the active layer 254, and the second conductive semiconductor layer 255 are grown sequentially, the first conductive semiconductor layer 253, the active layer 254, and the second conductive semiconductor layer 255 form a layer structure as shown in Fig. 5A.

[0060] In this case, the first conductive semiconductor layer 253 may be an n-type semiconductor layer, and the second conductive semiconductor layer 255 may be a p-type semiconductor layer. However, the present disclosure is not limited thereto, and the first conductivity type may be p-type and the second conductivity type may be n-type.

[0061] Furthermore, the present embodiment illustrates a case where the active layer is present, but it is also possible to use a structure in which the active layer is not present as described above. For such an example, the p-type semiconductor layer may be a p-GaN doped with Mg, and an n-electrode side in the n-type semiconductor layer may be a GaN doped with Si.

[0062] The growth substrate 259 (the wafer) may be formed from any material with light transmission properties, for example, but not limited to, sapphire (Al2O3), GaN, ZnO, and AlO. Furthermore, the growth substrate 259 may be formed from a carrier wafer, which is a material suitable for semiconductor material growth. The growth substrate (W) may be formed from a material with excellent thermal conductivity. For example, a SiC substrate with higher thermal conductivity than a sapphire (Al2O3) substrate or a SiC substrate containing Si and / or GaAs and / or GaP and / or InP and / or Ga2O3 may be used.

[0063] Next, at least a part of the first conductive semiconductor layer 253, the active layer 254, and the second conductive semiconductor layer 255 is removed to form a plurality of epi-chips of the semiconductor light-emitting devices ( Fig. 5B).

[0064] Specifically, the isolation is performed such that a plurality of light-emitting devices form an array of epi-chips. In other words, the first conductive semiconductor layer 253, the active layer 254, and the second conductive semiconductor layer 255 are etched in a vertical direction to form a plurality of light-emitting semiconductor devices.

[0065] When forming a horizontal semiconductor light-emitting device at this stage, the active layer 254 and the second conductive semiconductor layer 255 may be partially removed in a vertical direction to perform a mesa process in which the first conductive semiconductor layer 253 is exposed to the outside, and then the isolation layer in which the first conductive semiconductor layer is etched to form a plurality of semiconductor light-emitting device arrays. However, according to the present disclosure, since the mesa process is performed subsequent to self-assembly, the isolation process at this stage is performed without the mesa process. In this case, the semiconductor light-emitting device can be isolated to a circular size of 100 μm or less in diameter.

[0066] Next, a conductive electrode 256 (or a p-electrode) is formed on a surface of the second conductive semiconductor layer 255 ( Fig. 5C). The second conductive semiconductor electrode 256 may be formed by a deposition method such as sputtering, but the present disclosure is not necessarily limited thereto. However, when the first conductive semiconductor layer and the second conductive semiconductor layer are an n-type semiconductor layer and a p-type semiconductor layer, respectively, the second conductive electrode 256 may also be an n-type electrode.

[0067] Then, a magnetic body 257 is laminated onto the second conductive electrode 256. The magnetic body 257 may refer to a metal having a magnetic property formed on an epi-chip. The magnetic body may be Ni, Sn, Fe, Co, or the like, and, as another example, a material corresponding to Gd-based, La-based, and / or Mn-based materials.

[0068] The magnetic body 257 may serve as a post for dividing into top and bottom at the time of self-assembly afterward, and may have an area of ​​25% to 75% of the area of ​​the epi chip and a height of several hundred nanometers to several micrometers. However, the present disclosure is not limited to this, and the magnetic body may be provided in the second conductive electrode 256 in the form of particles. Furthermore, for a conductive electrode including a magnetic body, a single layer of the conductive electrode may be made of a magnetic body. For such an example, a second conductive electrode 256 may include a first layer on the inside and a second layer on the outside. Here, the first layer may be made to include a magnetic body, and the second layer may include a metal material other than a magnetic body.

[0069] Then, the growth substrate 259 is removed to provide a plurality of semiconductor light-emitting devices 250. For example, the growth substrate 259 may be removed using a laser lift-off (LLO) or a chemical lift-off (CLO) process ( Fig. 5D).

[0070] However, at this stage, the plurality of semiconductor light-emitting devices 250 do not have a complete structure like an epi-chip in a subsequent process. Then, the process of mounting the plurality of semiconductor light-emitting devices 250 on the substrate is performed in a fluid-filled chamber ( Fig. 5E).

[0071] For example, the semiconductor light-emitting devices 250 and the substrate are placed in a chamber filled with a fluid, and the semiconductor light-emitting devices 250 are mounted to the substrate by themselves using flow, gravity, surface tension, or the like.

[0072] In the present disclosure, the substrate may be a wiring substrate 261. In other words, the wiring substrate 261 is placed in the fluid chamber so that the semiconductor light-emitting devices 250 are mounted directly on the wiring substrate 261.

[0073] However, the self-assembly method described above needs to increase the transfer yield when applied to the fabrication of a large-screen display. The present disclosure proposes a method and apparatus for increasing the transfer yield.

[0074] In this case, in a display device according to the present disclosure, a magnetic force is applied to the magnetic body in the semiconductor light-emitting device to move the semiconductor light-emitting device, and places the semiconductor light-emitting device at predetermined positions in the moving process using an electric field. Hereinafter, such a transfer method and device will be described in more detail with reference to the accompanying drawings.

[0075] Fig. 6 is a conceptual view showing an example of a self-assembly apparatus for semiconductor light-emitting devices according to the present disclosure, and Fig. Figure 7 is a block diagram showing the self-assembly device in Fig. 6 shows. In addition, Fig. 8A to 8G are conceptual views showing a method for self-assembling semiconductor light-emitting devices using the self-assembly apparatus in Fig. Show 6.

[0076] According to the presentation of Fig. 6 and Fig. 7, a self-assembly device 160 of the present disclosure may include a fluid chamber 162, a magnet 163, and a positioning controller 164.

[0077] The fluid chamber 162 has a space for accommodating a plurality of semiconductor light-emitting devices. The space may be filled with a fluid, and the fluid may include water or the like as a mounting solution. Thus, the fluid chamber 162 may be a water tank and may be configured with an open type. However, the present disclosure is not limited thereto, and the fluid chamber 162 may be a closed type in which the space is formed with a closed space.

[0078] The substrate 261 may be arranged on the fluid chamber 162 so that a mounting surface on which the semiconductor light-emitting devices 250 are mounted faces downward. For example, the substrate 261 may be transferred to a mounting position by a transfer unit, and the transfer unit may include a stage 165 on which the substrate is mounted. The stage 165 is positioned by the controller, and the substrate 261 may be transferred to the mounting position by the stage 261.

[0079] At this time, the mounting surface of the substrate 261 at the mounting position faces the bottom of the fluid chamber 162. As shown, the mounting surface of the substrate 261 is positioned so as to be immersed in a fluid in the fluid chamber 162. Therefore, the semiconductor light-emitting devices 250 are moved in the fluid toward the mounting surface.

[0080] The substrate 261, which is a mounting substrate on which an electric field can be formed as well as a wiring substrate on which wiring lines are subsequently formed, may include a base portion 261a, a dielectric layer 261b, and a plurality of electrodes 261c, 261d.

[0081] The base portion 261a may be made of an insulating material, and the plurality of electrodes 261c may be a biplanar thin- or thick-film electrode patterned on one side of the base portion 261. The electrode 261c may be formed, for example, from a laminate of Ti / Cu, Ti, an Ag paste, ITO, and the like.

[0082] In particular, the electrode 261c may be a plurality of electrode pairs arranged on the substrate and provided with a first electrode 261c and a second electrode that generate an electric field when an electric current is supplied.

[0083] The dielectric layer 261b is made of an inorganic material such as SiO2, SiNx, SiON, Al2O3, TiO2, HfO2, or the like. Alternatively, the dielectric layer 261b may be composed of a single layer or multiple layers as an organic insulator. The thickness of the dielectric layer 261b may range from a few dozen nanometers to a few micrometers.

[0084] In addition, the wiring substrate 261 according to the present disclosure includes a plurality of cells 261d divided by partition walls.

[0085] For example, the wiring substrate 261 may be provided with cells 261d through which the semiconductor light-emitting devices 250 are inserted, so that the semiconductor light-emitting devices 250 can be easily mounted on the wiring substrate 261. Specifically, cells 261d on which the semiconductor light-emitting devices 250 are mounted are formed at positions on the wiring substrate 261 where the semiconductor light-emitting devices 250 are aligned with the wiring electrodes. The semiconductor light-emitting devices 250 are mounted in the cells 261d while moving in the fluid.

[0086] The cells 261d are arranged sequentially along one direction, and the partition walls 261e forming the cells 261d are shared with the adjacent cells 261d. In this case, the partition walls 261e may be made of a polymer material. Furthermore, the partition walls 261e protrude from the base portion 261a, and the cells 261d may be arranged sequentially along one direction by the partition walls 261e. Specifically, the cells 261d are arranged in row and column directions and may have a matrix structure.

[0087] As shown in the drawing, an interior of the cells 261d has a groove for accommodating the semiconductor light-emitting device 250, and the groove may be a space defined by the partition walls 261e. The shape of the groove may be the same as or similar to that of the semiconductor light-emitting device. For example, if the semiconductor light-emitting device has a rectangular shape, the groove may have a rectangular shape. Further, if the semiconductor light-emitting device is circular, the grooves formed in the cells may be circular, although not shown. Moreover, each of the cells is configured to accommodate a single semiconductor light-emitting device. In other words, a single semiconductor light-emitting device is accommodated in a single cell.

[0088] On the other hand, according to the present disclosure, a material similar to that of the partition walls 261e can be filled into the interior of the cells 261d through a subsequent process. Consequently, the partition walls 261e can be modified into a passivation layer surrounding the semiconductor light-emitting devices. This will be described later.

[0089] On the other hand, a plurality of electrodes may be arranged on the substrate and include a first electrode and a second electrode that generate an electric field when an electric current is applied. The first electrode and the second electrode may be referred to as an electrode pair 261c. In the present disclosure, a plurality of the electrode pairs 261c may be provided and arranged at the bottom of each of the cells 261d. The first electrode and the second electrode may be formed from electrode lines, and the plurality of electrode lines may be extended to adjacent cells.

[0090] The electrode pair 261c is arranged under the cells 261d, and different polarities are applied to it to generate an electric field in the cells 261d. To form the electric field, the dielectric layer may form the bottom surface of the cells 261d, while the dielectric layer may cover the electrode pair 261c. In such a structure, when different polarities are applied to the electrode pair 261c from a bottom surface of each cell 261d, an electric field can be formed, and the semiconductor light-emitting device can be inserted into the cells 261d by the electric field.

[0091] At the mounting position, the electrodes of the substrate 261 are electrically connected to the power supply unit 171. The power supply unit 171 applies power to the plurality of electrodes to generate the electric field.

[0092] As shown, the self-assembly device may include a magnet 163 for applying a magnetic force to the semiconductor light-emitting devices. The magnet 163 is spaced from the fluid chamber 162 to apply a magnetic force to the semiconductor light-emitting devices 250. The magnet 163 may be arranged to face an opposite side of the mounting surface of the substrate 261, and the position of the magnet is controlled by the positioning controller 164 connected to the magnet 163. The semiconductor light-emitting device 250 may have a magnetic body for moving in the fluid by the magnetic field of the magnet 163.

[0093] Referring to Fig. 6 and Fig. 7, the self-assembly device may, in particular, comprise a magnet handling device that can be moved automatically or manually in the x, y, and z axes on top of the fluid chamber, or comprise a motor capable of rotating the magnet 163. The magnet handling device and the motor may form the positioning controller 164. As a result, the magnet 163 rotates relative to the substrate 161 in a horizontal direction, a clockwise direction, or a counterclockwise direction.

[0094] On the other hand, a light-transmitting bottom plate 166 may be formed in the fluid chamber 162, and the semiconductor light-emitting devices may be disposed between the bottom plate 166 and the substrate 161. An image sensor 167 may be positioned to view the bottom plate 166 to monitor an interior of the fluid chamber 162 through the bottom plate 166. The image sensor 167 is controlled by the controller 172 and may include an inverted lens, a CCD, and the like to observe the mounting surface of the substrate 261.

[0095] The self-assembly device described above is configured to use a combination of a magnetic field and an electric field, and using these fields, the semiconductor light-emitting devices can be placed in predetermined positions on the substrate by an electric field in the process of being moved by a position change of the magnet. Such a new manufacturing method can be a detailed example of the method described above with reference to Fig. 5E. An assembly method using the self-assembly device described above will be described in more detail below.

[0096] First, the text with reference to Fig. 5A to 5D, a plurality of semiconductor light-emitting devices 250 are formed with magnetic bodies. In this case, in the process for forming the second conductive electrode in Fig. 5C a magnetic body can be deposited on the light-emitting semiconductor device.

[0097] Next, the substrate 261 is transferred to the mounting position, and the semiconductor light-emitting devices 250 are placed in the fluid chamber 162 ( Fig. 8A).

[0098] As described above, the mounting position of the substrate 261 is a position where the mounting surface on which the semiconductor light-emitting devices 250 of the substrate 261 are mounted is arranged in a downward direction in the fluid chamber 162.

[0099] In this case, some of the semiconductor light-emitting devices 250 may sink to the bottom of the fluid chamber 162, and some may float in the fluid. When the light-transmitting bottom plate 166 is provided in the fluid chamber 162, some of the semiconductor light-emitting devices 250 may sink to the bottom plate 166.

[0100] Next, a magnetic force is applied to the semiconductor light-emitting devices 250 so that the semiconductor light-emitting devices 250 float in the fluid chamber 162 in a vertical direction ( Fig. 8B).

[0101] When the magnet 163 of the self-assembly device moves from its original position to an opposite side of the mounting surface of the substrate 261, the semiconductor light-emitting devices 250 float in the fluid toward the substrate 261. The original position may be a position away from the fluid chamber 162. As another example, the magnet 163 may consist of an electromagnet. In this case, electricity is supplied to the electromagnet to generate an initial magnetic force.

[0102] Meanwhile, in this example, a separation distance between the mounting surface of the substrate 261 and the semiconductor light-emitting devices 250 can be controlled by adjusting the magnitude of the magnetic force. For example, the separation distance is controlled using the weight, buoyancy, and magnetic force of the semiconductor light-emitting devices 250. The separation distance can be from a few millimeters to dozens of micrometers from the outermost edge of the substrate.

[0103] Next, a magnetic force is applied to the semiconductor light-emitting devices 250 so that the semiconductor light-emitting devices 250 move in one direction in the fluid chamber 162. For example, the magnet 163 moves in a horizontal direction, a clockwise direction, or a counterclockwise direction with respect to the substrate ( Fig. 8C). In this case, the semiconductor light-emitting devices 250, in a position spaced from the substrate 161, move in a direction parallel to the substrate 161 by the magnetic force.

[0104] Next, the process of applying an electric field to move the semiconductor light-emitting devices 250 to predetermined positions of the substrate 161 is carried out to enable the semiconductor light-emitting devices 250 to be placed at the predetermined positions during the movement of the semiconductor light-emitting devices 250 ( Fig. 8D). The semiconductor light-emitting devices 250 move by the electric field in a direction perpendicular to the substrate 261 to be placed at predetermined positions while moving along a direction parallel to the substrate 161.

[0105] The plurality of semiconductor light-emitting devices are guided to predetermined positions on the substrate by an electric field and a magnetic field.

[0106] Specifically, electrical power is supplied to a pair of electrodes, i.e., a biplanar electrode of the substrate 261, to generate an electric field, and mounting is performed only at predetermined positions. In other words, the semiconductor light-emitting devices 250 are mounted using a selectively generated electric field at the mounting position of the substrate 261. For this purpose, the substrate may include cells into which the semiconductor light-emitting devices 250 are inserted.

[0107] At this time, the magnetic body 257 of the semiconductor light-emitting device 250 serves as a post for the top and bottom division. Specifically, when a surface with the magnetic body 257 facing toward the electrode pair 261c is inserted into the cell, the semiconductor light-emitting device cannot be placed on the bottom side of the cell (an outer surface of the dielectric layer) by the magnetic body 257.

[0108] On the other hand, the semiconductor light-emitting devices 250 may be guided to the predetermined positions, then the magnet 163 may move in a direction away from the substrate 261, so that the semiconductor light-emitting devices 250 remaining in the fluid chambers 162 fall to the bottom of the fluid chambers 162 ( Fig. 8E). As another example, when the power supply is stopped when the magnet 163 is an electromagnet, the semiconductor light-emitting devices 250 remaining in the fluid chamber 162 fall to the bottom of the fluid chamber 162.

[0109] Then, when the semiconductor light-emitting devices 250 are collected on the bottom of the fluid chamber 162, the collected semiconductor light-emitting devices 250 can be reused.

[0110] When the display device of the present disclosure uses blue semiconductor light-emitting devices, that is, when the semiconductor light-emitting devices are all blue semiconductor light-emitting devices, the blue semiconductor light-emitting devices can be mounted in all cells of the substrate.

[0111] On the other hand, according to this example, each of the red semiconductor light-emitting device, the green semiconductor light-emitting device, and the blue semiconductor light-emitting device can be arranged at a desired position. When the above semiconductor light-emitting device 250 is a blue semiconductor light-emitting device, the arrangement described with reference to Fig. 8A to 8E, generate an electric field only in a cell corresponding to a blue pixel to mount the blue light-emitting semiconductor device at a corresponding position.

[0112] Then this will be done with reference to Fig. 8A to 8E are carried out using the green light-emitting semiconductor device 250a and the red light-emitting semiconductor device 250b, respectively ( Fig. 8F and Fig. 8G). However, since the wiring substrate 261 is already arranged at the mounting position, the process of feeding the substrate to the mounting position can be omitted.

[0113] Then, the process for removing the wiring substrate 261 is carried out and the mounting process is completed.

[0114] The self-assembly device and method described above are characterized in that, in order to increase the assembly yield in a fluidic arrangement, parts are concentrated at a large distance adjacent to a predetermined assembly location using a magnetic field, and a separate electric field is applied to the assembly location to selectively assemble the parts only at the assembly location. At this time, the mounting substrate is placed on an upper portion of the water tank, and the mounting surface is facing downward, thereby preventing nonspecific coupling while minimizing the effect of gravity due to the weight of parts. In other words, to increase the transfer yield, the mounting substrate is placed on top to minimize the effect of gravity or frictional force and prevent nonspecific coupling.

[0115] In addition, the blue semiconductor light-emitting device, the green semiconductor light-emitting device, and the red semiconductor light-emitting device can be mounted at desired positions, respectively.

[0116] As described above, according to the present disclosure having the above configuration, a large number of semiconductor light-emitting devices can be simultaneously mounted in a display device in which individual pixels are formed with semiconductor light-emitting devices.

[0117] Once the assembly process as described above is completed, a process for manufacturing a display device can be carried out. Hereinafter, a manufacturing process for such a display device will be described in detail with reference to the drawings.

[0118] Fig. 9A to 9E are conceptual views showing a method of manufacturing a display device after self-assembling semiconductor light-emitting devices on a wiring substrate using the self-assembly apparatus of Fig. Show 6.

[0119] The movement of the semiconductor light-emitting devices in the fluid chamber is guided, and the semiconductor light-emitting devices are mounted at predetermined positions of the substrate by the above method, and then the magnetic bodies 257 of the semiconductor light-emitting devices are removed while the semiconductor light-emitting devices 250, 250a, 250b are mounted at the predetermined positions of the substrate 261 ( Fig. 9A and Fig. 9B).

[0120] While the blue light-emitting semiconductor device 250, the green light-emitting semiconductor device 250a and the red light-emitting semiconductor device 250b, as shown in Fig. 9A, are arranged one after the other along one direction, the magnetic bodies 257 provided in the blue light-emitting semiconductor device 250, the green light-emitting semiconductor device 250a and the red light-emitting semiconductor device 250b are arranged as shown in Fig. 9B shown, removed.

[0121] The removal of the magnetic body 257 can be carried out by a chemical or physical method and thereby the second conductive electrode 256 (see Fig. 5B) to the outside of the cell. On the other hand, the semiconductor light-emitting device may have a structure in which a magnetic body without the second conductive electrode 256 protrudes from the second conductive semiconductor layer 255 (see Fig. 5B), and in this case, the second conductive semiconductor layer 255 may be exposed to the outside of the cell.

[0122] Next, a mesa formation process may be performed while mounting the semiconductor light-emitting devices at predetermined positions of the substrate ( Fig. 9C).

[0123] For example, to produce the plurality of semiconductor light-emitting devices, the first conductive semiconductor layer 253 and / or the second conductive semiconductor layer 255 is / are etched while the semiconductor devices are mounted at predetermined positions of the substrate.

[0124] In particular, the second conductive semiconductor layer 255 facing an exterior of the cell is etched, and in this case, the second conductive electrode 256 and the active layer 255 (see hereinafter Fig. 5B) may also be etched together. As another example, in the case where a magnetic body is formed directly on a surface of the conductive semiconductor layer without the second conductive electrode 256, the magnetic body may protrude from a surface of the semiconductor layer to be etched between the first conductive semiconductor layer 253 and the second conductive semiconductor layer 255.

[0125] A portion of a surface opposite the surface in contact with the dielectric layer on the first conductive semiconductor layer 253 may be exposed to the outside by etching. A portion exposed to the outside may not overlap with an upper surface of the second conductive semiconductor layer 255 and may be a portion spaced apart in a horizontal direction. By such a mesa process, a flip-chip semiconductor light-emitting device is formed.

[0126] Next, the process of forming a passivation layer, performing planarization, and forming a contact hole is carried out ( Fig. 9D).

[0127] As shown, a passivation layer 270 can be filled between the plurality of semiconductor light-emitting devices. Specifically, as described above, the wiring substrate 261 includes a plurality of cells 261d divided by partition walls, and a gap is present between the cell and the semiconductor light-emitting device. The passivation layer 270 fills the gap while covering the semiconductor light-emitting device along with the partition walls.

[0128] Through such a method, a structure in which the passivation layer 270 surrounds the semiconductor light-emitting device can be formed on the display. In this case, the passivation layer 270 can be made of a polymer material to be integrated with the partition walls.

[0129] In the Fig. 9D, which is implemented by the above method, the passivation layer 270 may comprise a plurality of cells, and the plurality of semiconductor light-emitting devices may be accommodated in the cells. In other words, the cells provided in the final structure in the self-assembly process are changed into the interiors of the passivation layer 270. In this case, as described above, an electric field generated by the electrode pairs 261c described with reference to Fig. 9D are formed inside the cells. Furthermore, the plurality of cells are arranged in a matrix structure, and the plurality of electrode pairs 261c have a structure that extends to the neighboring cells.

[0130] Then, a planarization process is performed to planarize an upper surface of the passivation layer 270, and contact holes 271, 272 for wiring lines can be formed. The contact holes 271, 272 can be formed in the first conductive semiconductor layer 253 and the second conductive semiconductor layer 255, respectively.

[0131] Finally, the first wiring electrodes and the second wiring electrodes are connected to the plurality of semiconductor light-emitting devices through the contact holes ( Fig. 9E).

[0132] According to the presentation of Fig. 9E, the first wiring electrode 281 and the second wiring electrode 282 may be extended to a surface of the passivation layer 270. At this time, a surface of the passivation layer 270 may be a surface opposite to a surface that is the dielectric layer 261b. For example, the first wiring electrode 281 is extended to an upper surface of the passivation layer 270 on the first conductive semiconductor layer 253 through a first contact hole 271 formed on the first conductive semiconductor layer 253. The second wiring electrode 282 is extended to an upper surface of the passivation layer 270 through a second contact hole 272 formed on the second conductive semiconductor layer 255. However, as another example, when the second conductive electrode 256 (see Fig. 5D) is present on an upper surface of the second conductive semiconductor layer 255, the second wiring electrode 282 may be extended through the second contact hole 272 to an upper surface of the passivation layer 270.

[0133] Although the transfer according to such a structure is carried out by self-assembly, the wiring lines of the flip-chip semiconductor light-emitting devices can be implemented. In this case, the passivation layer 270 can be formed on a front side of the display device 100 (see Fig. 1), and at this time, the first wiring electrode 281 and the second wiring electrode 282 may be transparent electrodes. At this time, the pair of electrodes made of a metal material may be used as a reflective layer.

[0134] As another example, the passivation layer 270 may be disposed on a back surface of the display device 100, and at this time, the dielectric layer 261b and the base portion 261a of the substrate 261 are formed of a transparent material.

[0135] On the other hand, in the self-assembly process described above, as with reference to Fig. As described in Figures 8A to 8G, semiconductor light-emitting devices emitting light of different colors are sequentially arranged on the substrate. To arrange semiconductor light-emitting devices emitting light of different colors on a single substrate, the number of self-assembly methods must be equal to the number of types of semiconductor light-emitting devices. For example, at least three self-assembly methods are required to arrange semiconductor light-emitting devices emitting blue, red, and green on a single substrate.

[0136] On the other hand, to apply electrical power to the electrode pair arranged on the substrate during self-assembly, an external power source must be connected to the electrode pair. An electrode (hereinafter referred to as a bus electrode) for connecting the electrode pairs to the external power source is arranged at one edge of the substrate. Since the bus electrode is not an electrode used to drive a display, it is removed from the manufacturing process after self-assembly.

[0137] The present disclosure provides a method for minimizing a self-assembly process time. Specifically, the present disclosure provides a method for minimizing the time required to assemble semiconductor light-emitting devices that emit blue, red, and green light on a single substrate. Furthermore, the present disclosure provides a method for minimizing a process time for connecting the electrode pairs and the bus electrode and a process time for removing the bus electrodes.

[0138] For this purpose, a substrate used for a method of manufacturing a display device according to the present disclosure includes a mounting region and a non-mounting region. The mounting region refers to a region where the semiconductor light-emitting devices are arranged during self-assembly. A plurality of electrode pairs are arranged in the mounting region, and the semiconductor light-emitting devices are arranged such that they overlap with any one of the electrode pairs during self-assembly.

[0139] On the other hand, the non-mounting region refers to a region where the semiconductor light-emitting devices are not arranged during self-assembly. The non-mounting region may be a region that can be removed during a display manufacturing process and may not be present in the completed display device. However, the present invention is not limited to this, and at least a part of the non-mounting region may not be removed from the display manufacturing process but may remain. A plurality of bus electrodes connected to the pair of electrodes may be arranged in the non-mounting region.

[0140] The bus electrodes are connected to the external power source during self-assembly in order to apply a voltage to the electrode pair via the external power source.

[0141] At least two bus electrodes may be arranged in the non-mounting area. One of the two bus electrodes is connected to a first electrode of the electrode pair, and the other is connected to a second electrode of the electrode pair. When power is applied to the two bus electrodes, the first and second electrodes have different polarities. In this specification, two bus electrodes applied to the electrode pair are described as one type of bus electrode. For example, when two types of bus electrodes are arranged in the non-mounting area, the two bus electrodes connected to the first and second electrodes of one electrode pair are referred to as first bus electrodes, and the two bus electrodes connected to the first and second electrodes of another electrode pair are referred to as second bus electrodes.Furthermore, in this specification, a bus electrode connected to a pair of electrodes means that each of the two bus electrodes is electrically connected to each of the first and second electrodes of the pair of electrodes.

[0142] The non-mounting region may be formed at an edge of the mounting region. The plurality of electrode pairs may be arranged in parallel along one direction in the mounting region, and the bus electrodes arranged in the non-mounting region are electrically connected to the electrode pair at an edge of the mounting region.

[0143] On the other hand, a plurality of mounting regions may be formed on a single substrate. The spaced-apart mounting regions are used as substrates for different display devices. The electrode pairs arranged in different mounting regions may be connected to the same bus electrode. For example, a bus electrode connected to the first electrode included in the electrode pair and a bus electrode connected to the second bus electrode included in the electrode pair may be arranged in the non-mounting region. The electrode pairs arranged in each of the plurality of mounting regions may be electrically connected to the two bus electrodes.

[0144] When a voltage is applied between the two bus electrodes during the self-assembly process, an electric field is generated by the pair of electrodes arranged in each of the plurality of mounting regions. Consequently, the semiconductor light-emitting devices are arranged in each of the plurality of self-assembly regions by a self-assembly process. As described above, it may be possible to manufacture multiple display devices by a self-assembly process.

[0145] Hereinafter, a method for sequentially self-assembling blue, red and green light-emitting semiconductor devices is described in more detail.

[0146] Fig. 10 is a conceptual view showing pairs of electrodes arranged on a substrate, and Fig. 11 is a conceptual view showing a state in which a pair of electrodes and a bus electrode are connected, and Fig. 12 is a conceptual view showing a substrate having multiple mounting areas.

[0147] The processes of applying a magnetic force to the semiconductor light-emitting devices and guiding the semiconductor light-emitting devices to the predetermined positions are performed at least once while placing the semiconductor light-emitting devices that emit blue light in the fluid chamber, and at least once while placing the semiconductor light-emitting devices that emit red light in the fluid chamber, and at least once while placing the semiconductor light-emitting devices that emit green light in the fluid chamber. Here, the order of blue, red, and green is not specifically limited.

[0148] Here, the pair of electrodes to which the voltage is applied is changed according to the type of semiconductor light-emitting devices placed in the fluid chamber. Specifically, multiple pairs of electrodes are used. Fig. 10 into three groups. Hereinafter, the plurality of electrode pairs are divided into first to third groups. The blue semiconductor light-emitting devices overlap with any one of the electrode pairs belonging to the first group during self-assembly. The red semiconductor light-emitting devices overlap with any one of the electrode pairs belonging to the second group during self-assembly. The green semiconductor light-emitting devices overlap with any one of the electrode pairs belonging to the third group during self-assembly.

[0149] A voltage must be applied to the electrode pair belonging to the first group when the self-assembly is carried out while the blue light-emitting semiconductor devices are placed in the fluid chamber, and a voltage must be applied to the electrode pair belonging to the second group when the self-assembly is carried out while the red light-emitting semiconductor devices are placed in the fluid chamber, and a voltage must be applied to the electrode pair belonging to the third group when the self-assembly is carried out while the green light-emitting semiconductor devices are placed in the fluid chamber.

[0150] However, it is not necessary that a voltage be applied only to the electrode pair of a group corresponding to specific semiconductor light-emitting devices while specific semiconductor light-emitting devices are placed in the fluid chamber.

[0151] For example, a method for self-assembling blue, red, and green semiconductor light-emitting devices in sequence will be described as an example. When self-assembly is performed while the red semiconductor light-emitting devices are placed in the fluid chamber, the blue semiconductor light-emitting devices are already coupled to the substrate. At this time, if a voltage applied to the electrode pair belonging to the first group is turned off, the blue semiconductor light-emitting devices may be detached from the substrate. To prevent this, when self-assembly is performed while the red semiconductor light-emitting devices are placed in the fluid chamber, a voltage must be applied to both the first and second groups.In this case, an attractive force may be applied between the electrode pair belonging to the first group and the red light-emitting semiconductor devices, but since the blue light-emitting semiconductor devices are already arranged at predetermined positions, the red light-emitting semiconductor devices are not arranged to overlap with the electrode pair belonging to the first group.

[0152] Meanwhile, when self-assembling the green light-emitting semiconductor devices, voltages must be applied to the first to third groups while placing the green light-emitting semiconductor devices in the fluid chamber.

[0153] As described above, according to the present disclosure, voltages are applied to different electrode pairs according to the type of semiconductor light-emitting devices placed in a fluid chamber, so that the semiconductor light-emitting devices are guided to different electrode pairs according to the type of semiconductor light-emitting devices placed in the fluid chamber.

[0154] For this purpose, according to the present disclosure, reference may be made to Fig. Eleven electrically insulated first to third bus electrodes may be arranged in a non-mounting area of ​​the substrate. Furthermore, a mounting area may be formed on the substrate, and the electrode pairs arranged in the mounting area are classified into first to third groups. The first bus electrodes 331a, 332a are connected to the electrode pairs 311a, 312a belonging to the first group, the second bus electrodes 331b, 332b are connected to the electrode pairs 311b, 312b belonging to the second group, and the third bus electrodes 331c, 332c are connected to the electrode pairs 311c, 312c belonging to the third group. The bus electrodes are connected to different external power sources 341a, 341b, 341c, 342a, 342b, 342c. Through the structure described above, the present disclosure can selectively apply voltages to the electrode pairs.

[0155] On the other hand, several mounting areas can be formed on the substrate. Referring to Fig. 12, three electrode pairs can be arranged in each of the mounting areas (A and B) formed on the substrate. Here, the electrode pairs belonging to the same group are electrically connected to the same bus electrode. For example, the first group of electrode pairs 311a, 311b arranged in the first mounting area (A) and the first group of electrode pairs 311a, 311b arranged in the second mounting area (B) are electrically connected to the same bus electrodes 341a, 342a.

[0156] As described above, according to the present disclosure, voltages can be applied to multiple mounting areas simultaneously. Therefore, the present disclosure can manufacture multiple display devices including blue, red, and green semiconductor light-emitting devices using only three self-assembly methods. Furthermore, since the present disclosure allows multiple display devices to be manufactured using only one set of bus electrodes, it may be possible to reduce the time required to connect the electrode pair and the bus electrode, and the time required to remove the bus electrode.

[0157] Meanwhile, the present disclosure may further include removing the non-mounting region after the self-assembly process is completed. If the substrate includes a plurality of mounting regions, the plurality of mounting regions may be separated from each other during the non-mounting region removal process. The separated mounting regions are fabricated into different display devices.

[0158] As a result, multiple electrode pairs can remain in the mounting area. Hereinafter, a display device manufactured by the manufacturing method according to the present disclosure will be described.

[0159] Fig. 13 is a conceptual view showing the arrangement of semiconductor light-emitting devices and electrode pairs included in a display device according to the present disclosure, and Fig. 14 is a cross-sectional view of a display device including a thin film transistor.

[0160] According to the above manufacturing method, a display device according to the present disclosure may include: a substrate, a plurality of semiconductor light-emitting devices arranged on the substrate, a first wiring electrode and a second wiring electrode each extending from the semiconductor light-emitting devices to supply an electric signal to the semiconductor light-emitting devices, a plurality of electrode pairs arranged on the substrate to generate an electric field when an electric current is supplied and provided with first and second electrodes formed on a side opposite to the first and second wiring electrodes with respect to the semiconductor light-emitting devices, and a dielectric layer formed to cover the electrode pairs.Here, the multiple pairs of electrodes can be arranged parallel to each other along one direction.

[0161] Since the semiconductor light-emitting device is guided by an electric field formed between the first electrode and the second electrode included in the electrode pair during self-assembly, each of the plurality of semiconductor light-emitting devices can be arranged to overlap with any one of the electrode pairs.

[0162] On the other hand, when self-assembling semiconductor light-emitting devices that emit different colors, the semiconductor light-emitting devices that emit different colors overlap with different electrode pairs. Specifically, when the semiconductor light-emitting devices include a first semiconductor light-emitting device that emits a first color and a second semiconductor light-emitting device that emits a second color different from the first color, each of the first and second semiconductor light-emitting devices is arranged to overlap with a different electrode pair.

[0163] According to one embodiment, referring to Fig.13 in the case of a display device comprising a blue semiconductor light-emitting device 350a, a red semiconductor light-emitting device 350b and a green semiconductor light-emitting device 350c, the blue semiconductor light-emitting device 350a with a first electrode pair 311a, 312a, and the red semiconductor light-emitting device 350b overlaps with a second electrode pair 311b, 312b, and the green semiconductor light-emitting device 350c overlaps with a third electrode pair 311c, 312c.

[0164] This is because depending on the type of semiconductor light-emitting device placed in the fluid chamber, a voltage is applied to a different pair of electrodes.

[0165] On the other hand, a distance between the first and second electrodes included in each of the electrode pairs may be arranged smaller than that between the electrode pairs. Voltages may be applied to adjacent electrode pairs during self-assembly, and in this case, an electric field may also be generated between the electrode pairs. Due to this, the semiconductor light-emitting device can be guided between the electrode pairs. In the present disclosure, the intensity of an electric field formed between the first and second electrodes is greater than that of a magnetic field formed between the electrode pairs, thereby preventing the semiconductor light-emitting device from being guided between the electrode pairs.

[0166] On the other hand, a width of each of the electrode pairs may be larger than that of the semiconductor light-emitting device. This serves to ensure that the semiconductor light-emitting device is precisely positioned between the first and second electrodes.

[0167] Meanwhile, a display device according to the present disclosure can be implemented in an active matrix manner. For this purpose, a thin-film transistor can be used, and the thin-film transistor can be transferred to a substrate before self-assembly of the semiconductor light-emitting device. Therefore, the thin-film transistors 400 can be arranged on the same plane as the electrode pairs 311, 312.

[0168] According to the method and apparatus of the present disclosure described above, a large number of semiconductor light-emitting devices can be deposited on a wafer with a small size as pixels and then directly transferred to a large-area substrate. This makes it possible to manufacture a large-area display device at low cost.

Claims

[1] Display device comprising: a substrate (261); a plurality of semiconductor light-emitting devices (250) arranged on the substrate (261); a first wiring electrode (281) and a second wiring electrode (282) each extending from the semiconductor light-emitting devices (250) for supplying an electrical signal to the semiconductor light-emitting devices (250); a plurality of electrode pairs (261c, 311a, 312a, 311b, 312b, 311c, 312c) arranged on the substrate (261) to generate an electric field when an electric current is supplied, and which are provided with first and second electrode pairs formed on a side opposite to the first and second wiring electrodes (281, 282) with respect to the semiconductor light-emitting devices (250); and a dielectric layer (261b) formed to cover the electrode pairs (261c, 311a, 312a, 311b, 312b, 311c, 312c), wherein the plurality of electrode pairs (261c, 311a, 312a, 311b, 312b, 311c, 312c) are arranged along a direction parallel to each other. [2] The display device according to claim 1, wherein each of said plurality of semiconductor light-emitting devices (250) is arranged to overlap with any one of said plurality of electrode pairs (261c, 311a, 312a, 311b, 312b, 311c, 312c). [3] The display device according to claim 2, wherein the plurality of semiconductor light-emitting devices (250) comprise: a first semiconductor light-emitting device (250a) emitting a first color; and a second semiconductor light-emitting device (250b) emitting a second color different from the first color, and wherein the first and second semiconductor light-emitting devices (250a, 250b) are each arranged to overlap with mutually different electrode pairs. [4] A display device according to claim 1, wherein a distance between adjacent first and second electrodes (250a, 250b) is smaller than that between adjacent pairs of electrodes. [5] The display device according to claim 1, wherein a width of each pair of electrodes (261c, 311a, 312a, 311b, 312b, 311c, 312c) is larger than that of each semiconductor light-emitting device (250). [6] A display device according to claim 1, further comprising: a thin film transistor disposed on the substrate (261) and electrically connected to a semiconductor light-emitting device (250). [7] A display device according to claim 6, wherein the plurality of electrode pairs (261c, 311a, 312a, 311b, 312b, 311c, 312c) and the thin film transistor are arranged on the same plane of the substrate (261). [8] The display device according to claim 6, wherein the plurality of semiconductor light-emitting devices (250) are arranged on the dielectric layer (261b), and the first wiring electrode (281) and the second wiring electrode (282) are arranged on each of the plurality of semiconductor light-emitting devices (250) such that the dielectric layer (261b) is interposed between the plurality of semiconductor light-emitting devices (250) and the plurality of electrode pairs (261c, 311a, 312a, 311b, 312b, 311c, 312c), and the plurality of semiconductor light-emitting devices (250) are interposed between the first and second wiring electrodes (281, 282) and the dielectric layer (261b). [9] The display device according to claim 1, wherein widths of the plurality of electrode pairs (261c, 311a, 312a, 311b, 312b, 311c, 312c) are larger than widths of the first and second wiring electrodes (281, 282). [10] The display device according to claim 1, wherein the plurality of electrode pairs (261c, 311a, 312a, 311b, 312b, 311c, 312c) provide a magnetic force to establish a plurality of semiconductor light-emitting devices (250) on the substrate (261), and do not provide the electrical signal to generate an image of the display device. [11] The display device according to claim 1, wherein adjacent pairs of said plurality of electrode pairs (261c, 311a, 312a, 311b, 312b, 311c, 312c) are separated by a gap, and said plurality of semiconductor light-emitting devices (250) are arranged directly above said gap. [12] A self-assembly method for a plurality of semiconductor light-emitting devices (250), the method comprising: Transferring a substrate (261) having a mounting area and a non-mounting area to a mounting position; Providing the plurality of semiconductor light-emitting devices (250) in a fluid chamber (162); Applying a magnetic force to the plurality of semiconductor light-emitting devices (250) to move the plurality of semiconductor light-emitting devices (250) in the fluid chamber (162) along a direction; and Applying a voltage to a plurality of electrode pairs (261c, 311a, 312a, 311b, 312b, 311c, 312c) arranged on the substrate (261) to guide the plurality of semiconductor light-emitting devices (250) to predetermined positions to allow the plurality of semiconductor light-emitting devices (250) to be placed at the predetermined positions of the mounting area during the movement of the semiconductor light-emitting devices (250), wherein the plurality of electrode pairs (261c, 311a, 312a, 311b, 312b, 311c, 312c) are arranged on the mounting area of ​​the substrate (261), and bus electrodes (331a, 332a, 331b, 332b, 331c, 332c) electrically connected to the plurality of electrode pairs (261c, 311a, 312a, 311b, 312b, 311c, 312c) are arranged in the non-mounting area. [13] The method according to claim 12, wherein applying the voltage to the plurality of electrode pairs (261c, 311a, 312a, 311b, 312b, 311c, 312c) arranged on the substrate (261) by an external power source (341a, 341b, 341c, 342a, 342b, 342c) connected to the bus electrodes (331a, 332a, 331b, 332b, 331c, 332c) applies a voltage to the plurality of electrode pairs (261c, 311a, 312a, 311b, 312b, 311c, 312c). [14] The method according to claim 13, wherein a first bus electrode (331a, 332a) and a second bus electrode (331b, 332b) of the bus electrodes are arranged on the substrate (261), and wherein one electrode of the electrode pair (311a) is electrically connected to the first bus electrode (331a) and another electrode (312a) of the electrode pair is electrically connected to the second bus electrode (332a). [15] The method according to claim 14, wherein applying the magnetic force to the plurality of semiconductor light-emitting devices (250) and guiding the plurality of semiconductor light-emitting devices (250) to the predetermined positions are performed at least once while placing the plurality of semiconductor light-emitting devices (250) emitting a first color in the fluid chamber (162), and are performed at least once while placing the plurality of semiconductor light-emitting devices (250) emitting a second color different from the first color in the fluid chamber (162). [16] The method according to claim 15, wherein guiding the plurality of semiconductor light-emitting devices (250) to the predetermined positions applies a voltage to a different pair of electrodes for each type of the plurality of semiconductor light-emitting devices (250) placed in the fluid chamber (612) to guide the plurality of semiconductor light-emitting devices (250) to different pairs of electrodes depending on the type of the plurality of semiconductor light-emitting devices (250). [17] The method according to claim 12, wherein the substrate (261) has a plurality of mounting areas (A, B), and wherein the plurality of electrode pairs (261c, 311a, 312a, 311b, 312b, 311c, 312c) arranged in each of the plurality of mounting areas (A, B) are electrically connected to the same bus electrode from the bus electrodes. [18] The method of claim 17, further comprising: Dividing the substrate (261) by each mounting area (A, B). [19] The method of claim 12, wherein the plurality of electrode pairs (261c, 311a, 312a, 311b, 312b, 311c, 312c) apply the magnetic force to arrange the plurality of semiconductor light-emitting devices (250) on the substrate (261) and do not provide an electrical signal to drive the plurality of semiconductor light-emitting devices (250). [20] The method of claim 12, wherein adjacent pairs of said plurality of electrode pairs (261c, 311a, 312a, 311b, 312b, 311c, 312c) are separated by a gap, and said plurality of semiconductor light-emitting devices (250) are disposed directly above said gap.

Images