WO2016080709A1 - Method for arranging micro-led elements in electrode assembly - Google Patents

Abstract

The present invention relates to a method for arranging micro-LED elements in an electrode assembly and, more specifically, to a method for arranging micro-LED elements in an electrode assembly, which can increase accessibility such that, when a micro-LED element on a nanoscale is connected onto a micro electrode on a nanoscale, the micro-LED element can be placed in a target position on the electrode, and can achieve mass production through a reduction in the manufacturing time required for the arrangement of micro-LED elements and an increase of convenience.

Description

How to place an ultra-small LED device in an electrode assembly

The present invention relates to a method of disposing an ultra-small LED device in an electrode assembly, and more particularly, to connect a micro-scale LED device on a nano-scale micro electrode to a micro-LED device at a desired electrode position. The present invention relates to a method of disposing an ultra-small LED device in an electrode assembly that can be mass-produced by improving accessibility and shortening the manufacturing time and convenience of the micro LED device.

LED has been actively developed in 1992 by Nakamura of Nichia, Japan, by applying a low-temperature GaN compound complete layer to fuse high-quality monocrystalline GaN nitride semiconductors. An LED is a semiconductor having a structure in which n-type semiconductor crystals in which a plurality of carriers are electrons and p-type semiconductor crystals in which a plurality of carriers are holes are bonded to each other by using characteristics of a compound semiconductor. It is a semiconductor device that is converted to light and expressed. These LED semiconductors are called light revolutions because of their high light conversion efficiency, very low energy consumption, semi-permanent and environmentally friendly life. Recently, the development of compound semiconductor technology has led to the development of high-brightness red, orange, green, blue, and white LEDs, which have been used in many fields such as traffic lights, cell phones, automotive headlights, outdoor billboards, LCD back light units, and indoor and outdoor lighting. It is being applied to and is being actively researched at home and abroad. In particular, GaN-based compound semiconductors having a wide bandgap are materials used in the manufacture of LED semiconductors emitting light in the green, blue and ultraviolet regions, and many studies have been conducted since white LED devices can be manufactured using blue LED devices. Is being done.

On the other hand, in order to utilize the LED device for lighting, display, etc., the LED device and an electrode capable of supplying power to the device are required. The arrangement of the two electrodes has been studied in various ways.

The study of the arrangement of the LED element and the electrode can be classified into the growth of the LED element on the electrode and the LED element is grown separately and placed on the electrode.

First, a study of growing an LED device on an electrode involves thinning a lower electrode on a substrate, and sequentially stacking an n-type semiconductor layer, an active layer, a p-type semiconductor layer, and an upper electrode on the substrate, and then stacking the electrode prior to etching or stacking the upper electrode. There is a bottom-up method in which LED devices and electrodes are simultaneously generated and arranged in a series of manufacturing processes by etching the layers and then stacking the upper electrodes.

Next, a method of arranging the LED elements separately and independently on the electrodes is a method of individually disposing each LED device independently grown and manufactured on the patterned electrodes through separate processes.

The former method has a problem that it is very difficult to crystallize very high crystallinity and high efficiency of the thin film and the LED device, and the latter method has a problem that the light extraction efficiency is lowered and the luminous efficiency may be lowered. In addition, the latter method can be used to connect the three-dimensional LED device manually or mechanically one by one if the LED device of the normal size, but manually or mechanically connected to the electrode one by one if the LED device is a micro-sized micro-sized unit. It is very difficult to arrange a very small LED device on a nanoscale electrode and difficult to connect the disposed small LED device with the electrode.

Specifically, the Republic of Korea Patent Application No. 2013-0080427 was invented by the inventor of the present invention to solve the problem according to the latter method, more specifically Figure 1 is a micro LED device disclosed in the patent application to the electrode As a schematic diagram showing a manufacturing process for self-alignment, a nano-scale micro electrode formed on the base substrate 100 in a solution state by including the micro LED device 120 manufactured by growing independently as shown in FIG. 1A in a solvent 140. After input to the (110, 130), and then applied power to the two different electrodes (110, 130) as shown in Figure 1b to self-align the ultra-small LED device is connected to the two different small electrodes as shown in Figure 1c. . This overcomes the conventional difficulty of connecting a small LED device to two different small electrodes, but electrode areas other than the electrode area to which the small LED device should be connected as the small LED device is put into the electrode in solution. As the ultra-small LED device is opened, the number of micro-LED devices arranged in the desired electrode region has been significantly reduced. This problem significantly reduces the performance of the lighting and display to be implemented by including an ultra-small LED device, and the micro-LED device has to be put into the electrode in a solution state, which is not suitable for mass production.

In addition, in order to solve the above problems, when repeatedly adding a solution containing a small LED device, even if the number of the small LED device disposed in the desired electrode region can be increased, the manufacturing time, manufacturing according to the repeated input of the solution There is a problem that causes a significant increase in costs and is unsuitable for mass production.

Accordingly, the micro LED device is more easily disposed in the desired electrode region among the micro electrodes, and even after the device is disposed on the electrode, the micro LED device does not spread beyond the intended electrode region, thereby making the micro LED device an intended electrode region. There is an urgent need for research on a method that can be connected more easily.

The present invention has been made to solve the above-described problems, it is possible to more easily arrange the ultra-small LED element in the desired electrode region of the micro-electrode, even after the element is disposed on the electrode the electrode region of the micro-LED element By not spreading, it is possible to connect the micro LED device to the intended electrode area more easily, significantly reducing the deployment time of the micro LED device on the electrode, and improving the convenience of placement, thereby enabling mass production. The present invention relates to a method of disposing an ultra-small LED element in an electrode assembly, which can be applied to products such as LED lamps and LED displays of excellent quality by significantly increasing the number of micro-LED elements disposed in a desired electrode region.

In order to solve the above problems, the present invention, (1) a composite fiber assembly including a composite fiber comprising a fiber-forming component and a plurality of ultra-small LED device; And (2) removing the fiber forming component of the composite fiber.

According to a preferred embodiment of the present invention, the composite fiber assembly may be in the shape of any one of yarn, woven fabric, knitted fabric and nonwoven fabric.

According to another preferred embodiment of the present invention, the plurality of micro-elements may be included in the composite fiber, the plurality of micro-elements may be arranged in at least one row in the longitudinal direction of the composite fiber.

According to another preferred embodiment of the present invention, the composite fiber is a core portion formed by forming a plurality of ultra-small LED elements in a row; And a fiber forming component formed around the core portion.

According to another preferred embodiment of the present invention, the diameter of the composite fiber may be 1.2 to 8.0 times the shorter length of the ultra-small LED device, more preferably 1.2 to 6.0 times.

According to another preferred embodiment of the present invention, the plurality of ultra-small LED device may be arranged in a plurality of rows in the longitudinal direction of the composite fiber.

According to another preferred embodiment of the present invention, the fiber forming component in the group consisting of PMMA (Poly (methyl methacrylate)), PVA (Polyvinyl alchol) PS (Polystyrene), PVC (Polyvinyl chloride) and PVA (Polyvinyl acetate) It may include any one or more polymer compounds selected.

According to another preferred embodiment of the present invention, the composite fiber may include 30 to 90 parts by weight of the ultra-small LED device with respect to 100 parts by weight of the fiber forming component.

According to another preferred embodiment of the present invention, the micro LED device has a rod shape, and the micro LED device may have a length of 100 nm to 10 μm.

According to another preferred embodiment of the present invention, the micro LED device comprises a first conductive semiconductor layer; An active layer formed on the first conductive semiconductor layer; And a second conductive semiconductor layer formed on the active layer. In addition, the micro LED device may include a first electrode layer formed under the first conductive semiconductor layer; And a second electrode layer formed on the second conductive semiconductor layer. In addition, the outer surface of the micro LED device may be coated with an insulating coating covering at least the entire outer surface of the active layer portion.

According to another preferred embodiment of the present invention, step (2) may remove the fiber forming component by treating at least one or more of heat or a solvent.

According to another preferred embodiment of the present invention, the solvent may include any one or more solvents selected from the group consisting of acetone, toluene and isopropyl alcohol.

On the other hand, in order to solve the above problems, the present invention, a plurality of electrodes; And a composite fiber assembly disposed on the plurality of electrodes, the composite fiber assembly including a composite fiber including a fiber forming component and a plurality of ultra-small LED devices.

In addition, the present invention to solve the above problems, the base substrate; A plurality of electrodes formed on the base substrate; And a plurality of ultra-small LED elements positioned on the plurality of electrodes after being injected onto the plurality of electrodes with the composite fibers including the fiber forming component and then removing the fiber forming component.

According to a preferred embodiment of the present invention, the plurality of microminiature elements are included in the composite fibers in at least one row in the longitudinal direction of the composite fibers,

After the composite fiber is put on the plurality of electrodes, the fiber forming component of the composite fiber is removed so that the plurality of ultra-small LED elements can be positioned in at least one row on the plurality of electrodes.

According to another preferred embodiment of the present invention, the plurality of microminiature elements are included in the composite fiber in a core shape having one or more rows formed therein with respect to a sheath formed of a fiber forming component, and the composite fiber is formed on a plurality of electrodes. After being injected into, the ultra-small portions of the composite fibers are removed so that the plurality of ultra-small LED elements can be positioned in at least one row on the plurality of electrodes.

The composite fiber assembly including the ultra-small LED device of the present invention can more easily place the micro-LED device in a desired electrode region of the micro-electrode than when the micro-LED device is simply included in a solvent and put into the micro-electrode in a solution state. After the micro LED device is disposed on the electrode, the micro LED device does not spread beyond the target electrode area, thereby easily connecting the micro LED device to the target electrode area. Significantly reduce the batch time to enable mass production and at the same time significantly increase the number of ultra-small LED elements arranged in the desired electrode area can be widely applied to products such as LED lamps, LED displays of excellent quality.

1 is a schematic diagram showing a manufacturing process of self-aligning an ultra-small LED element to an electrode.

2 is a perspective view of a composite fiber according to a preferred embodiment of the present invention.

FIG. 3 is an optical micrograph showing a micro LED device disposed on an electrode after the micro LED device is included in a solvent and injected onto the electrode.

4 is a perspective view of a micro LED device included in a preferred embodiment of the present invention.

5 is a vertical cross-sectional view of a conventional micro electrode assembly.

FIG. 6 is a plan view and a vertical sectional view of a micro LED electrode assembly in which a micro LED device is connected to a first electrode and a second electrode through a composite fiber assembly according to a preferred embodiment of the present invention.

7 is a perspective view of a composite fiber according to a preferred embodiment of the present invention.

8 is a plan view of a micro LED electrode assembly in which a micro LED device is connected to an electrode through a composite fiber assembly according to a preferred embodiment of the present invention.

9 is a perspective view of a composite fiber according to a preferred embodiment of the present invention.

FIG. 10 is a schematic diagram illustrating a method of disposing an ultra-small LED device in an electrode assembly according to an exemplary embodiment of the present invention.

11 is a cross-sectional perspective view of a composite fiber included in a preferred embodiment of the present invention.

12 is a cross-sectional view of a double orifice spinning nozzle used for producing a composite fiber included in a preferred embodiment of the present invention.

13 is a cross-sectional perspective view of an island-in-the-sea fiber manufactured according to a preferred embodiment of the present invention.

14 is a plan view of a composite fiber assembly including a composite fiber according to a preferred embodiment of the present invention.

FIG. 15 is a schematic diagram illustrating a method of disposing an ultra-small LED device in an electrode assembly according to an exemplary embodiment of the present invention.

16 is a perspective view of an electrode included in a preferred embodiment of the present invention.

Hereinafter, the present invention will be described in more detail.

As described above, in order to connect an ultra-small LED device to an ultra-small electrode, a micro-LED device is included in a solvent and placed in a solution state, and the micro-LED device is placed on an electrode. As the micro LEDs are extended to the electrode regions other than the electrode regions to which the micro LEDs are connected as they are introduced into the electrodes, the number of micro LEDs arranged in the desired electrode region has been significantly reduced. In addition, such a problem significantly reduces the performance of the lighting and display to be implemented by including a small LED device, and the micro LED device has to be put into the electrode in solution in one bar, which is unsuitable for mass production. Furthermore, in order to solve the above problems, if the solution containing the ultra-small LED element is repeatedly added, the manufacturing time and manufacturing time due to the repeated dosing of the solution may be increased even though the number of the micro-LED elements disposed in the desired electrode region may be increased. There were problems that led to a significant increase in costs and unsuitable for mass production. In the present invention, (1) a composite fiber aggregate comprising a composite fiber comprising a fiber-forming component and a plurality of ultra-small LED device; And (2) removing the fiber-forming component of the composite fiber. The above-described problem was sought by providing a method of disposing an ultra-small LED device in an electrode assembly. This makes it easier to place the micro LED device in the desired electrode region of the micro electrodes, and even after the device is disposed on the electrode, the micro LED device does not spread out beyond the intended electrode region. It can be more easily connected to the electrode region, it is possible to significantly reduce the placement time of the small LED element on the electrode to enable mass production and at the same time significantly increase the number of the small LED element disposed in the desired electrode region.

As a step (1) according to the present invention, a step of introducing a composite fiber aggregate comprising a composite fiber comprising a fiber forming component and a plurality of ultra-small LED device on the electrode.

First, a description will be given of a composite fiber comprising a fiber-forming component and a plurality of ultra-small LED device included in the composite fiber assembly.

2 is a perspective view of a composite fiber according to a preferred embodiment of the present invention, the composite fiber 30A includes a fiber forming component 10 and a plurality of micro LEDs 20, the plurality of micro LEDs The device 20 is included in the fiber forming component 10.

The fiber forming component may serve as a support for supporting a plurality of ultra-small LED elements included therein and may provide easier access than placing the ultra-small LED elements in a desired electrode region. It is easier to handle than managing in solution, and it can be more advantageous to realize mass production and large area electrode assembly because it is easy to place a small LED device in a desired electrode region of a large area of the small electrode line. .

Conventional micro LED devices are included in a solvent when placed on a micro electrode and are put on the electrode in a solution state. At this time, the micro LED device is suspended in a solution without any directivity, and thus the place where the solution is first introduced is an LED device. Even after the intended electrode region to be disposed, there is a problem that after the introduction of the solution, the ultra-small LED device spreads out of the desired electrode region or to the edge of the desired electrode region.

Specifically, FIG. 3 is an optical microscope photograph of a micro LED device disposed on an electrode after the micro LED device is included in a solvent and injected into an electrode. As shown in FIG. 3, the micro LED device has a central portion of an electrode region. You can see that the focus is placed on the edges rather than the edges. Accordingly, the present inventors continue to research to solve the above problems, and when the micro LED device is included in the support electrode and placed in the target electrode region, it is physically supported by the support that the micro LED device spreads out of the target electrode region. As it is blocked by the present invention, it has been found that the micro LED device can be more easily disposed in the desired electrode region.

Accordingly, the fiber forming component may be used without limitation in the case of a material capable of supporting a plurality of micro LED devices, but may be easily removed through the step (2) to be described later, and may be made of fiber. It may be, and may be a material that does not have a physical / chemical effect on the micro LED device. More preferably a thermoplastic polymer compound removed by heat; And / or a polymer compound removed by any one or more solvents selected from the group consisting of acetone, toluene, chloroform and isopropyl alcohol; The thermoplastic polymer compound may include at least one or more of the above, and specifically, the thermoplastic polymer compound removed by the heat may have a melting point of 50 ° C. to 400 ° C., more preferably 50 ° C. to 300 ° C., and as a non-limiting example, PMMA ( Use of one or two or more polymer compounds such as poly (methyl methacrylate), PS (polystyrene), PVC (polyvinyl chloride), PVA (polyvinyl acetate), PE (polyethylene), PET (Polyethylene terephthalate) and PP (polypropylene) In addition, the polymer compound dissolved by the solvent preferably includes at least one polymer compound selected from the group consisting of PMMA (Poly (methyl methacrylate)), PS (Polystyrene), PVC, and PVA.

The reason why the polymer compound which can function as a support as the fiber forming component and can be easily removed by being removed by heat and / or by solvent is more preferable because the composite fiber assembly including at least one composite fiber is formed on the electrode. This is because it is required to remove the fiber forming component surrounding the micro LED device to directly connect the micro LED device to the electrode after being disposed. Accordingly, a polymer compound which can be easily removed by heat and / or a solvent is particularly preferable. Through this, the composite fiber assembly is disposed on the electrode, and the fiber-forming component is removed in step (2) described below, and the ultra-small LED device is electrode. The time required to position the phase can be significantly reduced.

On the other hand, when the fiber-forming component is a polymer compound that is dissolved by a solvent, there is a further advantage that both the removal of the fiber-forming component and the self-alignment of the ultra-small LED device can be performed through one solvent input. In detail, the reason for including the ultra-small LED device 120 in the solvent 140 in FIG. 1A and injecting the electrodes 110 and 130 into the solvent 140 is that the ultra-small LED device has almost no mobility, thus making it difficult to self-align the electrode. Because. More specifically, as shown in FIG. 1B, when the power is applied to the electrodes 110 and 130, the outer surface of the micro LED device 120 is charged with a positive charge or a negative charge by symmetry with respect to the longitudinal center of the micro LED device by electric field induction. Resulting in polarization. If there is no solvent, the ultra small LED device having polarized external surface of the device is very difficult to move to two electrodes having different potentials by electrostatic attraction and to be connected to the self alignment and the electrode. In order to improve self-alignment, a mobile phase such as a solvent is required. If the fiber-forming component is a polymer compound dissolved by a solvent, the fiber-forming component is dissolved in the solvent when the solvent is added to the composite fiber assembly in step (2) described later. To form a solution, and the solution can function as a mobile phase capable of moving and aligning the ultra-small LED elements disposed on the electrodes, thereby removing the fibrous component and then self-aligning the ultra-small LED elements to the electrodes without additional solvent. And there is an advantage that can be connected.

Next, a plurality of ultra-small LED devices included in the composite fiber together with the above-described fiber forming component will be described.

The ultra-small LED device that can be used in the present invention can be used without limitation as long as it is a micro-LED device generally used for lighting or display, preferably, the length of the ultra-small LED device can be 100 nm to 10 ㎛, even more preferably May be 500 nm to 5 μm. If the length of the ultra-small LED device is less than 100 nm, it is difficult to manufacture a high-efficiency LED device, and if it exceeds 10 μm, the luminous efficiency of the LED device may be reduced. In addition, the diameter of the ultra-small LED device may be preferably 100nm to 5㎛. The shape of the ultra-small LED device may be a rod shape, specifically, may be a variety of shapes, such as a cylinder, a rectangular parallelepiped, and preferably may be a cylindrical shape, but is not limited to the above description.

Hereinafter, in the description of the ultra-small LED device, 'up', 'down', 'up', 'low', 'upper' and 'lower' refer to the vertical up and down directions based on each layer included in the ultra-small LED device. Means.

First, according to one preferred embodiment of the present invention, the micro LED device may include a first conductive semiconductor layer; An active layer formed on the first conductive semiconductor layer; And a second conductive semiconductor layer formed on the active layer.

Specifically, FIG. 4 is a perspective view of an ultra-small size LED device included in a preferred embodiment of the present invention, and includes a first conductive semiconductor layer 20b, an active layer 20c formed on the first conductive semiconductor layer 20b, and the active layer. The second conductive semiconductor layer 20d formed on 20c is shown.

First, the first conductive semiconductor layer 20b will be described.

The first conductive semiconductor layer 20b may include, for example, an n-type semiconductor layer. When the micro LED device is a blue light emitting device, the n-type semiconductor layer has a composition formula of In _x Al _y Ga _1-xy N (0 = x = 1, 0 = y = 1, 0 = x + y = 1). At least one of a semiconductor material having, for example, InAlGaN, GaN, AlGaN, InGaN, AlN, InN, or the like may be selected, and a first conductive dopant (eg, Si, Ge, Sn, etc.) may be doped. Preferably, the thickness of the first conductive semiconductor layer 20b may be 500 nm to 5 μm, but is not limited thereto. Since the light emission of the ultra-small LED is not limited to blue, there is no limitation in using another type III-V semiconductor material as the n-type semiconductor layer when the emission color is different.

Next, the active layer 20c formed on the first conductive semiconductor layer 20b will be described.

When the micro LED device is a blue light emitting device, the active layer 20c may be formed on the first conductive semiconductor layer 20b and may have a single or multiple quantum well structure. A cladding layer (not shown) doped with a conductive dopant may be formed on and / or under the active layer 20c, and the cladding layer doped with the conductive dopant may be formed of an AlGaN layer or an InAlGaN layer. In addition, materials such as AlGaN and AlInGaN may also be used as the active layer 20c. In the active layer 20c, when an electric field is applied, light is generated by the combination of the electron-hole pairs. Preferably, the thickness of the active layer 20c may be 10 to 200 nm, but is not limited thereto. The position of the active layer 20c may be formed in various ways depending on the type of LED. Since the light emission of the ultra-small LED is not limited to blue, there is no limitation in using another type III-V semiconductor material as the active layer when the emission color is different.

Next, the second conductive semiconductor layer 20d formed on the active layer 20c will be described.

When the ultra-small LED device is a blue light emitting device, a second conductive semiconductor layer 20d is formed on the active layer 20c, and the second conductive semiconductor layer 23 may be implemented with at least one p-type semiconductor layer. be used in the p-type semiconductor layer is a semiconductor material having a compositional formula of _{in x Al y Ga 1 -x- y} N (0 = x = 1, 0 = y = 1, 0 = x + y = 1) , for example, At least one of InAlGaN, GaN, AlGaN, InGaN, AlN, InN, and the like may be selected, and a second conductive dopant (eg, Mg) may be doped. Here, the light emitting structure includes the first conductive semiconductor layer 20b, the active layer 20c, and the second conductive semiconductor layer 20d as minimum components, and another phosphor layer above and below each layer, It may further include an active layer, a semiconductor layer and / or an electrode layer. Preferably, the thickness of the second conductive semiconductor layer 20d is 50 nm to 500 nm But may not be limited thereto. Since the light emission of the ultra-small LED is not limited to blue, there is no limitation in using another type III-V semiconductor material as the p-type semiconductor layer when the emission color is different.

In addition, according to a preferred embodiment of the present invention, the micro LED device may further include a first electrode layer formed below the first conductive semiconductor layer and a second electrode layer formed above the second conductive semiconductor layer.

Specifically, FIG. 4 shows the first electrode layer 20a formed below the first conductive semiconductor layer 20b and the second electrode layer 20e formed above the second conductive semiconductor layer 20d.

The first electrode layer 20a and the second electrode layer 20e may use a metal or a metal oxide used as an electrode of a conventional LED device. Preferably, each of chromium (Cr), titanium (Ti), and aluminum is independently used. (Al), gold (Au), nickel (Ni), ITO and oxides or alloys thereof may be used alone or in combination, but is not limited thereto. Preferably, the thickness of the first electrode layer 20a and the thickness of the second electrode layer 20e may be 1 to 100 nm, respectively, but are not limited thereto. In the case where the ultra-small LED device includes the first electrode layer 20a and the second electrode layer 20e, the first conductive semiconductor layer 20b and / or the second conductive semiconductor layer 20d; There is an advantage that the metal ohmic layer can be formed at a temperature lower than the temperature required in the process of forming the mixed layer.

On the other hand, the outer surface of the ultra-small LED device may be coated with an insulating coating covering at least the entire outer surface of the active layer portion.

The insulating film 20f serves to prevent an electrical short circuit occurring when the active layer 20c included in the ultra-small LED device contacts the electrode. In addition, the insulating film 20f protects the outer surface of the device including the active layer 20c and the semiconductor layer of the ultra-small LED device, thereby preventing deterioration in luminous efficiency of the ultra-small LED device.

Specifically, in FIG. 4, the insulating film 20f is coated on the outer surface of the micro LED device including the outer surface of the active layer 20c. The insulating film 20f as described above further prevents an electrical short circuit and prevents the durability and light extraction efficiency of the ultra-compact LED device due to damage to the external surface of the semiconductor layer, thereby reducing the first semiconductor layer 20b and the second semiconductor layer. The insulating film 20f may be coated on any one or more of 20d. However, a fatal problem may occur in which an ultra-small LED element does not even emit light when an electrical short circuit occurs before discussing a decrease in light extraction efficiency. Therefore, at least an outer surface of the active layer 20c may be disposed on an outer surface of the micro-LED element 20. An insulating film 20f covering the entire surface may be coated.

The problem of the electrical short circuit may occur because it is difficult to manually and automatically arrange and connect the nano LED micro LED devices to different nano electrodes. In order to solve the problem of disposition and connection of the ultra-small LED device, the inventors of the present invention used a method of applying the power to different electrodes to self-align the micro-LED devices at once and connecting them to two different electrodes. When aligning, the ultra-small LED device moves between two different electrodes and changes its position, and in this process, the active layer 20c of the micro-LED device contacts the electrode line and the active layer 20c is connected to the electrode. There may be a problem that an electrical short occurs frequently.

On the other hand, when a small LED device is erected upright on an electrode by a method of mounting a small LED device on an electrode, and the other electrode is disposed on the top of the device, there is a problem of electrical short circuit caused by contact between the active layer and the electrode line. May not occur. In other words, the active layer and the electrode line can be contacted only when the LED element is laid on the electrode because the small LED element cannot stand upright on the electrode. In this case, the micro LED element is not connected to two different electrodes. There is a problem in that the device is not electrically connected to two different electrodes, and the problem of an electrical short may not occur. Specifically, FIG. 5 is a vertical cross-sectional view of a conventional micro electrode assembly, in which a first semiconductor layer 71 a of a first micro LED element 71 communicates with each other on a first electrode line 61, and a second semiconductor layer ( It can be seen that 71c) is in communication with the second electrode line 62, and the first ultra-small LED element 71 is in communication with each other in an upright position. In the electrode assembly shown in FIG. 5, if the first ultra-small LED device 71 is connected to two electrodes at the same time, there is no possibility that the active layer 71b of the device contacts any one of two different electrodes 61 and 62. Electrical shorts due to contact between the active layer 71b and the electrodes 61 and 62 do not occur.

In contrast, in FIG. 5, the second ultra-small LED element 72 lies on the first electrode 61, and in this case, the active layer 72b of the second ultra-small LED element 72 is in contact with the first electrode 61. . However, in this case, the second micro LED device 72 is not connected to the first electrode 61 and the second electrode 62, respectively, but only an electrical short is not a problem.

 Accordingly, the first conductive semiconductor layer 71a, the active layer 71b, and the second conductivity of the first ultra-small LED device 71 of FIG. 5 in the ultra-small LED electrode assembly having the connection structure of the electrode and the ultra-small LED device as shown in FIG. 5. Although the coating is coated on the outer surface of the semiconductor layer 71c, the coating may have only the purpose and effect of reducing the luminous efficiency through the damage prevention of the outer surface of the ultra-small LED device, and does not have the purpose and effect of preventing the electrical short.

However, the composite fiber assembly according to the present invention is different from the conventional ultra-small electrode assembly as shown in FIG. Inevitably, an electrical short problem due to contact and / or connection between the active layer and the electrode of the micro LED device, which did not occur in the conventional micro electrode assembly, inevitably occurs. Accordingly, in order to prevent this, the outer surface of the micro LED device may include an insulating coating covering at least the entire outer surface of the active layer portion.

In addition, in the micro LED device having a structure in which the first conductive semiconductor layer, the active layer, and the second conductive semiconductor layer are sequentially vertically arranged like the micro LED device included in the preferred embodiment of the present invention, the active layer must be exposed to the outside. There is no choice but to. In addition, the position of the active layer in the LED device of such a structure is not only located at the center of the center in the longitudinal direction of the device, it can be formed to be biased toward a specific semiconductor layer, the possibility of contact between the electrode and the active layer is bound to be higher. Therefore, an ultra-small LED device including an insulating coating coated over the entire outer surface of the active layer to prevent contact between the electrode and the active layer is connected to the electrode without an electric short to emit light in which the insulating film is not coated on the outer surface of the device. There is a more advantageous advantage in achieving the object of the invention than in the device.

Specifically, FIG. 6 shows a plan view and a vertical sectional view of a micro LED electrode assembly in which a micro LED device is connected to a first electrode and a second electrode through a composite fiber according to a preferred embodiment of the present invention. As can be seen in Figure 6 it can be seen that the ultra-small LED device is connected to the two different electrodes lying parallel to the electrode surface. However, as shown in the cross-sectional view of the AA, the active layer 121b of the first ultra-small LED elements 121a, 121b and 121c is not located at the center of the first ultra-small LED element 121 but is deviated much to the left. In this case, the active layer 121b The possibility of part contacting the electrode 111 may be increased, which may cause an electrical short circuit, which may cause a failure of the micro LED electrode assembly. In order to solve the above problems, the ultra-small LED device included in the present invention may be coated with an insulating film on the outer circumference including the active layer, and the active layer as shown in the first micro LED device 121 of FIG. 6 due to the insulating film. Even if 121b is connected to the electrode, a short circuit may not occur.

The insulating film 20f is preferably selected from silicon nitride (Si ₃ N ₄ ), aluminum oxide (Al ₂ O ₃ ), hafnium oxide (HfO ₂ ), yttrium oxide (Y ₂ O ₃ ), and titanium dioxide (TiO ₂ ). It may include any one or more, and more preferably consists of the above components, but may be transparent, but is not limited thereto. In the case of the transparent insulating film, by reducing the luminous efficiency that may occur in any case by coating the insulating film while serving as the insulating film 20f.

However, according to a preferred embodiment of the present invention, the insulating film 20f may not be coated with an insulating film on any one or more electrode layers of the first electrode layer 20a and the second electrode layer 20e of the micro LED device, More preferably, both electrode layers 20a and 20e may not be coated with an insulating coating. This is to be in electrical communication between the two electrode layers (20a, 20e) and the different electrodes, if the insulating film (20f) is coated on the two electrode layers (20a, 20e) can interfere with the electrical communication, the light emission of the ultra-small LED There is a problem that the light emission itself may not be reduced or not electrically connected. However, since there is no problem when the two electrode layers 20a and 20e are electrically connected between different electrodes, the insulating film 20f may contact the electrodes with the first electrode layer 20a and the second electrode layer 20e of the micro LED device. It may be included in the remaining portions of the first electrode layer 20a and the second electrode layer 20e except for a portion (eg, an end portion of the electrode layer).

On the other hand, according to a preferred embodiment of the present invention, the micro LED device may include a hydrophobic film coated on the outer surface of the insulating film of the micro LED device in order to prevent aggregation between the devices.

Specifically, in FIG. 4, the hydrophobic film 20g coated on the outer periphery of the insulating film 20f may be confirmed. The hydrophobic coating (20g) is to prevent the agglomeration between the LED devices by having a hydrophobic characteristic on the surface of the ultra-small LED device as a micro-LED device when it is radiated together with the fiber-forming component to produce a composite fiber, micro LED device It can be more advantageous to minimize the coagulation of the liver and arrange them in rows without aggregation in the composite fiber. In addition, after removing the fiber-forming component from the composite fiber, there is a problem that it is difficult to move and position the electrode lines when the micro LEDs remain in the aggregated state on the electrode, and the hydrophobic coating is easier to eliminate such problems. It is possible to self-align the small LED device in the electrode line.

The hydrophobic film 20g may be formed on an insulating film, and may be used without limitation as long as it can prevent aggregation between micro LED devices, and preferably octadecyltrichlorosilane (OTS). Self-assembled monolayers (SAMs) such as fluoroalkyltrichlorosilane, perfluoroalkyltriethoxysilane, and fluoropolymers such as teflon and Cytop. ) May be used alone or in combination, but is not limited thereto.

The fiber forming component and the ultra-small LED device included in the above-described composite fiber may include 30 to 90 parts by weight of the ultra-small LED device based on 100 parts by weight of the fiber forming component according to the preferred embodiment of the present invention. If the fiber forming component contains less than 30 parts by weight of the ultra-small LED device, the number of ultra-small LED devices per unit volume of the composite fiber is small, so the number of ultra-small LED devices that can be disposed through the composite fiber assembly in a predetermined electrode area is increased. It may be significantly lowered, and a larger amount of composite fiber aggregates should be included in order to place more ultra-small LED devices, in which case the time required for the removal of the fiber forming component and the cost required for the removal of the fiber-forming component in step (2) described later. There can be problems that can rise. If the ultra small LED device contains more than 90 parts by weight, the number of micro LED devices that can be included per unit volume of the composite fiber may increase, but the top, bottom, left and right spacing between the micro LED devices in the composite fiber becomes short, and in some cases, the micro LED device May be arranged in a cluster, and contact between the devices may occur frequently and / or the devices may be exposed to the outer surface of the composite fiber, thereby causing damage to the outer surface of the device.

On the other hand, according to a preferred embodiment of the present invention, the composite fiber comprises a fiber forming component 10 and a plurality of micro LED device 20, as shown in Figure 2, the plurality of micro LED device 20 is a fiber More preferably, it is located inside the forming component 10.

Specifically, the ultra-small LED device 20 included in the composite fiber 30A of FIG. 2 is located inside the fiber forming component 10. If the ultra-small LED device 20 is located inside the fiber forming component 10. However, when exposed to the outer surface of the fiber forming component 10, there is a possibility of damage to the outer surface of the ultra-small LED device during the storage, movement, and handling of the composite fiber, damage of the outer surface of the ultra-small LED device can improve the light extraction efficiency There may be a problem that can be remarkably lowered so that a product of reduced quality can be implemented. Accordingly, the micro LED device is more preferably located inside the fiber forming component.

However, the composite fiber assembly including the composite fiber is disposed on the electrode, and in order to improve the arrangement alignment state of the ultra-small LED device remaining on the electrode after the fiber forming component is removed in step (2) to be described later. The plurality of ultra-small LED device may be included in the composite fiber arranged in at least one row in the longitudinal direction of the composite fiber.

Specifically, FIG. 7 is a perspective view of a composite fiber included in a composite fiber assembly according to a preferred embodiment of the present invention. The composite fiber 30B includes a fiber forming component 10 and a plurality of ultra-small LED devices 20. The micro LED device 10 is arranged inside the composite fiber in a first row P ₁ and a second row P _{2 in} the longitudinal direction of the composite fiber. When the composite fiber assembly including the composite fiber 30B is disposed on the electrode, the micro LED device 20 remaining on the electrode after the fiber forming component 10 is removed in step (2) will be described later. It can be arranged to be perpendicular to the two different electrodes in the longitudinal direction of the, so that when the power is applied to the electrode, the ultra-small LED device moves the minimum moving distance until it is connected to the electrode and at the same electrode area The number of micro LEDs that can be connected to the electrodes can be significantly increased.

Specifically, FIG. 8 is a plan view of a micro LED electrode assembly in which a micro LED device is connected to an electrode through a composite fiber assembly included in a composite fiber assembly according to an embodiment of the present invention, as shown in FIG. 2. In the case of using a composite fiber assembly including a composite fiber 30A in which a plurality of micro LED devices 20 are arranged without direction, the micro LED device, which remains on the electrode after the fiber forming component is removed, also has no orientation on the electrode. It may be arranged randomly, the micro LED device 20 ′ connected to the electrode when power is applied to the electrodes 110 and 130 may also be connected to two different electrodes 110 and 130 without direction as shown in FIG. 8. . When the ultra-small LED device is connected to different electrodes without constant direction as shown in FIG. 8, one micro-LED device is connected to a constant electrode area as the area occupying two different electrodes increases while preventing the electrode connection of the other ultra-small LED device. There may be a problem that the number of micro LED devices is reduced. Specifically, in FIG. 8, the area (Q) occupying two different electrodes while the first ultra-small LED device 20 ′ obliquely connected to the electrode blocks the electrode connection of the other ultra-small LED devices, and the longitudinal direction of the device is as perpendicular to the electrode as possible. It can be seen that the second ultra-small LED element 21 ′ connected to and lying close to is significantly larger than the area R occupying two different electrodes.

On the other hand, according to a preferred embodiment of the present invention, the composite fiber assembly further improves the arrangement arrangement state of the ultra-small LED device remaining on the electrode after the fiber forming component is removed in step (2) described later, and the fiber forming component In order to further facilitate the removal of the composite fiber, a plurality of micro LED elements are formed in a row in a row; And a fiber forming component comprising a core formed around the core. The core fiber may include a composite fiber of a heart type.

Specifically, FIG. 9 is a perspective view of a composite fiber included in a composite fiber assembly according to a preferred embodiment of the present invention. In the composite fiber 30C of FIG. 5, a plurality of micro LED devices 20 are arranged in a row (P _3). The core portion formed in a) and the fiber forming component 10 includes a core portion formed to surround the core portion.

The composite fiber assembly including the composite fiber 30C as shown in FIG. 9 is a composite fiber including the composite fiber 30B in which a plurality of micro LED devices in the composite fiber 30B are arranged in two rows as shown in FIG. 7. When the fiber forming component is removed through step (2) to be described later, the arrangement of the ultra-small LED elements remaining on the electrodes may be easier than the vertical arrangement of the two different electrodes.

Specifically, FIG. 10 is a schematic view illustrating a method of disposing an ultra-small LED device in an electrode assembly according to an exemplary embodiment of the present invention, wherein a plurality of micro-LED devices 210b and 220b are formed inside the fiber forming components 210a and 220a. 9 shows a process of placing a composite fiber assembly including three composite fibers 210, 220, and 230 arranged in a row on the first electrode 201 and the second electrode 202. As can be seen in Figure 10a, the composite fiber assembly comprising a composite fiber as shown in Figure 9 is two electrodes different from each other in the arrangement arrangement of the ultra-small LED device remaining on the electrode when the fiber forming component is removed through step (2) to be described later It may be more advantageous to place it as shown in FIG. 10B so as to be perpendicular to.

In contrast, the composite fiber assembly including the composite fiber 30B as shown in FIG. 7 includes a first row P ₁ and a second row P ₂ formed of a plurality of micro LED devices included in the composite fiber 30B. Composite fibers arranged vertically in the composite fiber 30B with the two rows perpendicular to the electrode plane with respect to the electrode plane including the two electrodes even if disposed on the electrode so as to be perpendicular to the two mutually different electrodes. It may include. When the composite fiber is removed from the fiber forming component, the plurality of micro LEDs included in the first row P ₁ positioned close to the electrode plane may be arranged vertically close to the electrode as shown in FIG. 10B. However, the plurality of micro LED devices included in the second column P ₂ disposed above the first column P ₁ based on the electrode plane have a directionality as shown in FIG. 8 in the process of removing the fiber forming component. There may be a problem that can be placed on the electrode while being lost.

In addition, the composite fiber 30B as shown in FIG. 7 has a large diameter of the composite fiber as compared to the composite fiber 30C as shown in FIG. 9, which has an area of the remaining fiber forming component except for the ultra-small LED device in the cross section of the composite fiber. As it means larger, more removal time and / or more removal solvent may be required to remove the fiber forming component in step (2) described later in order to place the ultra-small LED device on the electrode.

9 is a diameter (a) of FIG. 9 is preferably 1.2 to 8.0 times the shorter length of the ultra-small LED device (b of FIG. 9), and more preferably 1.2 to 6.0 times. Through this, the ultra-small LED device may be included without being exposed to the outer surface of the composite fiber, and may have advantages such as shortening the removal time of the fiber forming component in step (2) to be described later, and reducing the input amount of the removal solvent.

In addition, according to another preferred embodiment of the present invention, the plurality of ultra-small LED device is the length of the composite fiber to increase the number of micro-LED devices disposed on the electrode before the self-aligned ultra-small LED device connected to the electrode It can be arranged in a plurality of columns in the direction. Specifically, FIG. 11 is a perspective view of a composite fiber included in a composite fiber assembly according to a preferred embodiment of the present invention, wherein the plurality of micro LED devices 21, 22, and 23 in the composite fiber 30D are arranged in five rows. By arranging, the arrangement of the ultra-small LED elements remaining on the electrode when the fiber forming component is removed in step (2), which will be described later, may be arranged to be perpendicular to two different electrodes, and at the same time, the fiber forming component 10 is removed. In this case, there is an advantage in that the number of ultra-small LED devices remaining in two different electrode areas of a predetermined area can be significantly increased.

The above-described composite fiber can be prepared through the following manufacturing method. However, the manufacturing method described below is only one embodiment, and the present invention is not limited by the description of the manufacturing method described below.

 Method for producing a composite fiber according to the present invention can be used for producing a conventional fiber, specifically by chemical spinning or electrospinning, the chemical spinning is specifically melt spinning, wet spinning, dry spinning It may be by any one or more methods selected from, such as wet and dry spinning. Composite fiber according to the present invention can be produced by selecting and changing the appropriate method of the spinning method in consideration of the specific type of the fiber-forming component used, the diameter of the desired composite fiber.

Method for Producing Composite Fiber According to the Present Invention As an example, a method for manufacturing a composite fiber including an ultra-small LED device by a melt spinning method during chemical spinning will be described.

First, as a step (a), it can be prepared a spinning solution containing a micro LED device.

The spinning solution may be prepared by melting and / or dissolving a fiber-forming component to make a solution state and then mixing a micro LED device.

In addition, the spinning solution may be prepared as the first spinning solution and the second spinning solution according to the shape of the detention or composite fibers used. In this case, the first spinning solution may be prepared by melting and / or dissolving the first fiber forming component into a solution state, and the second spinning solution may be prepared by including an ultra-small LED device in a solvent such as acetone or micro-LED. The device may be manufactured by incorporating the second fiber forming component into a molten and / or dissolved solution. Melting temperature or the solvent of the fiber-forming component can be determined in consideration of the fiber-forming component used specifically, it is not particularly limited in the present invention.

In addition, the spinning solution may be prepared separately before being introduced into the spinning machine and may be introduced into the spinning machine, or the fiber forming component may be added to a hopper included in a conventional spinning machine, and the micro LED device may be mixed with the melted fiber forming component through a melting part to form a sugar. It may be prepared by a method known in the art. At this time, the intrinsic viscosity of the spinning solution may be determined in consideration of the spinning easiness, preferably 0.1 ~ 2.0 cps, more preferably 0.1 ~ 1.2 cps, through which the amount of the composite fiber is cut after spinning significantly There is an advantage in terms of being able to reduce and maintain the form stability of the composite fiber after spinning. However, the intrinsic viscosity may be changed according to the type of fiber forming component used, the type of spinning machine used, and the design of the detention.

Next, by spinning the spinning solution prepared in the step (b) it can be produced a composite fiber.

In the case of the detention used for spinning of the spinning solution, when manufacturing the composite fiber 30A as shown in FIG. 2, a spinneret having a single tubular spinning nozzle may be used, but as shown in FIG. Is arranged in a row, the spinneret may be a double tubular spinneret, specifically, FIG. 12 is a double orthogonal spinneret 5 used in the manufacture of a composite fiber included in a preferred embodiment of the present invention. As a cross-sectional view of the dual tubular spinning nozzle 5, the external tube 2 of the above-mentioned step (1) is discharged into the outer tube 2, and the inner tube 1 of the second step of the above (a) step is discharged. The spinning solution can be discharged. However, the composite fiber 30 C as shown in FIG. 9 may be manufactured through a single tubular spinning nozzle when the diameter of the nozzle is adjusted in the single tubular spinning nozzle, but may not necessarily be manufactured only through the double tubular spinning nozzle. Composite fiber spun through the nozzle as described above may be a staple yarn or filament yarn and the filament number of the filament yarn may vary depending on the detention is not particularly limited in the present invention.

The composite fiber spun through the step (b) may be subjected to a partial stretching or stretching process to improve the strength of the fiber and to further align the arrangement of the ultra-small LED device included in the composite fiber in the fiber length direction. . The specific method of the stretching or partial stretching may be by a publicly known method known in the art, and is not particularly limited in the present invention.

On the other hand, the diameter of the composite fiber produced through the above-described method may be preferably 200nm ~ 15㎛. However, in order to manufacture a composite fiber of micro units or nano units, a composite fiber may be manufactured by using an electrospinning method widely used in the art or by preparing a island-in-the-sea type fiber by a chemical spinning method, and then removing the sea component.

In the case of the electrospinning method, as in step (a), the composite fiber may be manufactured through two kinds of spinning solution and two nozzles, or the composite fiber may be manufactured through one spinning solution and one nozzle. At this time, the diameter of the nozzle may be changed in consideration of the length of the long axis or short axis of the ultra-small LED device included in the spinning solution, the distance between the tip and the collector during the electrospinning, the voltage is the type of fiber-forming component used, the spinning solution It may be changed in consideration of the viscosity, the diameter of the composite fiber and the like is not particularly limited in the present invention, the specific electrospinning method can be used in the art conventional methods.

Next, the method for producing a composite fiber through the island-in-the-sea fiber is a method of spinning a spinning solution containing a heterogeneous polymer compound different from the fiber-forming component as a sea component, and a fiber-forming component and a micro LED as a island component. It can be prepared by spinning the use solution. Specifically, Figure 13 is a cross-sectional perspective view of the island-in-the-sea fiber (30E) prepared in accordance with a preferred embodiment of the present invention, the island-in-the-sea fiber (30E) is a island component (30C ₁ , 30C ₂ , 30C ₃ ) and sea component 40, wherein the island component 30C ₁ includes a fiber forming component 10 and an ultra-small LED device 20.

The sea component 40 of the island-in-the-sea fiber 30E may be a conventional alkali-soluble copolymer in the art that can be dissolved by a solvent (for example, an alkaline solution) that is difficult to dissolve the fiber-forming component. . Accordingly, even if the manufacturing process the fiber-type (30E) To a solution of alkali such as when to remove the sea component 40 island component of the composite fiber (30C _1, 30C _2, 30C ₃ ) can be obtained.

The composite fiber assembly disposed on the electrode in step (1) according to the present invention includes the composite fiber prepared according to the above-described manufacturing method.

The composite fiber assembly may be in the shape of any one of a yarn, a woven fabric, a knitted fabric, and a nonwoven fabric. First, the composite fiber aggregate may be in the shape of a yarn. The yarn may be staple yarns and / or filament yarns, and may be monolithic monofilament yarns and / or multifilament yarns. Alternatively, the staple yarn may be spun yarn spun yarn, or may be a twisted yarn in which a plurality of spun yarn and filament yarn are combined. However, in the case of the shape of the thread, the specific shape is not limited to the above description, and the shape of the thread known in the art may be all possible.

In addition, the fact that the composite fiber assembly is in the form of a yarn means that the composite fiber is included as it is, in which the physical (eg thermal) / chemical adhesion (eg, between the composite fibers or different portions of one composite fiber) For example, it may mean that the shape of the fabric by the non-woven fabric or weaving, etc. with the use of heterogeneous adhesive).

Next, the composite fiber assembly may have a fabric shape of a woven or knitted fabric.

The composite fiber aggregate having a fabric shape of the fabric or knitted fabric may include the composite fiber as a yarn used when weaving or knitting the fabric or knitted fabric. In this case, the composite fiber assembly may include the composite fiber as a single yarn, or may include the composite fiber as a warp or weft of a fabric or a knitted fabric using the composite fiber and heterogeneous yarn.

The fabric may be any one or more of plain weave, twill weave, satin weave and double weave. The double weave refers to the structure of a fabric in which either one of the warp yarns or the weft yarns is doubled or both are doubled. Specific weaving method according to the structure of the fabric may be a weaving method known in the art. However, the fabric is not limited to the description of the specific fabric structure, and in the case of the weft density in the weaving is not particularly limited.

In addition, the knitted fabric may include a composite fiber as a yarn, and may be by the method of knitting or warp knitting, and the specific method of knitting and warp knitting may be by conventional knitting or warp knitting.

Specifically, FIG. 14 is a plan view of a composite fiber assembly including a composite fiber according to a preferred embodiment of the present invention. The composite fiber assembly of FIG. 14 includes a plurality of ultra-small LED devices 20 and a fiber forming component 10. The composite fiber 30 is included in the weft (or warp) is a woven fabric woven plain. At this time, the heterogeneous yarn 50 other than the composite fiber 30 included in the fabric can be easily removed in step (2) to be described later by the same method as the fiber forming component 10 included in the composite fiber 30. It may be a yarn containing a high molecular compound, and may include a compound of the same or different types as the fiber forming component (10).

If the composite fiber assembly having the shape of a fabric or knitted fabric as shown in Figure 14 includes only the composite fiber in any one of the warp or weft yarn, to place the ultra-small LED device in the electrode assembly in which two different electrodes are alternately arranged in a row There is an advantage that can be arranged in the longitudinal direction of the ultra-small LED device, the micro-LED device on the two electrodes close to the vertical.

Specifically, FIG. 15 is a schematic diagram illustrating a method of disposing an ultra-small LED device according to an exemplary embodiment of the present invention in an electrode assembly.

First, FIG. 15A includes composite fibers 310, 320, and 330 in which the plurality of micro LEDs 310b and 320b are arranged in a row in the fiber forming components 310a and 320a as wefts (or warp yarns). And placing the fabric including the yarns 310 'and 320' containing the same polymer compound as the fiber forming component as the warp yarn (or the weft yarn) on the first electrode 301 and the second electrode 302. Indicates. Subsequently, when the fiber forming components 310a and 320a and the yarns 310 'and 320' are removed as described in step (2), the micro LEDs 310b and 320b are alternately arranged side by side as shown in FIG. 13B. It may be disposed on the first electrode and / or the second electrode close to the vertical in the longitudinal direction of the ultra-small LED device.

Next, the composite fiber assembly may have a shape of a nonwoven fabric including a composite fiber. The composite fiber assembly having the shape of a nonwoven fabric may include more amount of the composite fiber per unit volume of the composite fiber assembly than the composite fiber assembly having the shape of the fabric, and thus may be disposed on an electrode of a predetermined area. There is an advantage that can significantly increase the number of ultra-small LED device. Such a nonwoven fabric-like composite fiber assembly may be prepared using the composite fiber by methods known in the art, specifically, a melt-blown method, a flash-extrusion method, a super- The method may be any one of a super-draw method and the like, and the specific process of the method may be known in the art.

Step (1) according to the present invention is a step of injecting the above-described composite fiber assembly on the electrode. First, the electrode will be described. The electrode preferably refers to an electrode in which the micro LED device remaining after the fiber forming component included in the composite fiber assembly is removed in step (2) to be described later is mounted, and the micro LED device is applied when power is applied to the electrode. It may include two different electrode lines so as to emit light, and the specific arrangement of the two electrode lines may be differently designed depending on the purpose is not particularly limited in the present invention.

However, since the ultra-small LED device disposed according to the present invention is connected to two different electrodes by laying parallel to the electrode surface, the two different electrodes included in the electrode region where the micro LED device is finally mounted on two different electrode lines It may be located on the same plane. Specifically, FIG. 16 is a perspective view of an electrode included in a preferred embodiment of the present invention. The electrode line of FIG. 16 includes: a first electrode 411 formed on a base substrate 400; and the first electrode 411 Insulating layer 420 formed on the base substrate 400, including; The first electrode and the first electrode 413 formed on the insulating layer 420 spaced apart on the same plane and alternately mutually A second electrode 412 formed, a second electrode 421 connected to the second electrode; And a connection electrode 412 connecting the first electrode and the first electrode 411.

In the case of the electrode line of FIG. 16, the first electrode 411 and the second electrode 421 may be located on different planes, but may be included in an area S in which the micro LED device may be mounted. The first electrode 413 and the second electrode 421 may be formed on the same plane, whereby the axis connecting the first conductive semiconductor layer and the second conductive semiconductor layer is parallel to the same plane. The device may be connected to the electrode while lying down.

The electrode included in step (1) according to the present invention may be embodied in various thicknesses and widths of the electrode according to various shapes and structures that can be implemented according to the purpose, and are not particularly limited in the present invention. However, in the case of an electrode included in an electrode region in which an ultra-small LED device is finally mounted, the width may be 100 nm to 50 μm, and the thickness may be 0.1 to 10 μm. The material of the electrode may be a known electrode material commonly used in the art, preferably at least one metal material selected from the group consisting of aluminum, titanium, indium, gold and silver or indium tin oxide (ITO) It may be any one or more transparent materials selected from the group consisting of, ZnO: Al and CNT-conductive polymer (polmer) composite. When the electrode includes two or more materials, preferably, two or more materials may be stacked, and more preferably, a titanium / gold stacked structure, but is not limited thereto.

In the method of injecting the composite fiber assembly into the electrode as described above, by forming the composite fiber contained in the composite fiber assembly directly on the electrode by electrospinning or the like, the formation and arrangement of the composite fiber assembly on the electrode can be performed simultaneously. Alternatively, the composite fiber assembly prepared separately may be placed on the desired electrode region in various ways, and thus the specific method for arranging the composite fiber assembly on the electrode is not particularly limited.

Next, in step (2) according to the present invention, step (1) may be performed to remove the fiber forming component of the composite fiber contained in the composite fiber assembly.

When the fiber forming component of the composite fiber is removed through the step (2), only the ultra-small LED device remains on the electrode, and specifically, the composite disposed on the first electrode 201 and the second electrode 202 in FIG. 10A. When the fiber forming components 210a and 220a of the composite fibers 210, 220, and 230 included in the fiber assembly are removed, the micro LEDs 210b and 220b are formed on two different electrodes 201 and 202 as shown in FIG. 10B. The small LED device may be disposed on the electrode.

In detail, as illustrated in FIG. 15A, a plurality of micro LED devices 310b and 320b are arranged in a row in the fiber forming components 310a and 320a on the first electrode 301 and the second electrode 302. Fabric comprising a composite fiber (310, 320, 330) arranged in a weft (or warp), and comprising a yarn (310 ', 320') containing the same polymer compound as the fiber forming component as a warp (or weft) Position it. Subsequently, when the fiber forming components 310a and 320a and the yarns 310 'and 320' are removed, the first and / or second electrodes in which the ultra-small LED elements 310b and 320b are alternately arranged side by side as shown in FIG. 15B. It can be disposed close to the vertical in the longitudinal direction of the ultra-small LED device.

The specific method of removing the fiber forming component of the composite fiber in the step (2) may vary depending on the specific type of the fiber forming component contained in the composite fiber, if the fiber forming component is a material that is easily removed by heat ( In the step 2), the fiber forming component may be removed through a heating process, and the specific temperature may vary depending on the type of the fiber forming component used, and thus the present invention is not particularly limited.

In addition, if the fiber-forming component is a material easily removed by the solvent, the solvent may be added to the composite fiber assembly in step (2) to dissolve the fiber-forming component so that the micro LED device remains on the electrode. At this time, the solvent may vary depending on the type of fiber forming component used, but preferably may be any one or more of acetone, toluene, chloroform and isopropyl alcohol. In addition, according to the specific type of the fiber forming component, step (2) may remove the fiber forming component using heating and a solvent.

Hereinafter, a process of self-aligning and connecting the micro LED device to two different electrodes after the fiber forming component is removed through the step (2) and only the micro LED device remains on the electrode will be described.

Specifically, FIG. 10B (or FIG. 15B) shows a state in which the ultra-small LED elements 210b and 220b are disposed on two different electrodes on the electrode, and in this state, the ultra-small LED element is located on the electrode. Each of the first conductive semiconductor layer and the second conductive semiconductor layer of the LED device is not simultaneously connected to the first electrode 201 or the second electrode 202. In order to implement an electrode assembly including a micro LED device capable of emitting a micro LED device, the first conductive semiconductor layer of the micro LED device is connected to the first electrode 201 or the second electrode 202, and the second conductive A process of connecting the semiconductor layer to an electrode different from the electrode to which the first conductive semiconductor layer is connected is required. This process is possible by applying power to two different electrodes 201 and 202 as shown in FIG. 10C, and a polarization phenomenon in which positive and negative charges are charged on the outer surface of the micro LED device by the power applied to the electrodes. In addition, the micro LED device may be moved by the electrostatic attraction and may be connected to two different electrodes as shown in FIG. 10D.

Preferably, the power supply may be a variable power supply having an amplitude and a period, and the waveform may be a pulse file consisting of sinusoidal waveforms such as sine waves or non-sinusoidal waveforms. As an example Apply AC power, Alternatively, DC power is repeatedly applied to the first electrode for 1000 times per second, 0V, 30V, 0V, 30V, 0V, 30V, and 30V, 0V, 30V, 0V, 30V, 0V is repeated to the second electrode as opposed to the first electrode. It is also possible to make a fluctuating power source with amplitude and period by applying it. Preferably the voltage (amplitude) of the power supply may be 0.1V to 1000V, the frequency may be 10 Hz to 100 GHz, preferably the micro LED device is applied to two different electrodes by applying power for 5 to 120 seconds. Can be connected at the same time.

On the other hand, preferably, a solvent may be added in the process of self-aligning the ultra-small LED device by applying the power (FIG. 10C). The solvent may serve as a mobile phase that allows the micro LED device to be easily moved and connected to the electrode. In particular, when the fiber-forming component is removed by heat in step (2) according to the present invention, it may be more preferable to add a solvent in the power supply step.

The time point at which the solvent is introduced into the electrode line may be the same as or different from the time point at which power is applied to the electrode line, and may be the same.

On the other hand, the present invention is a plurality of electrodes; And a composite fiber assembly disposed on the plurality of electrodes, the composite fiber assembly including a composite fiber including a fiber forming component and a plurality of ultra-small LED devices.

The electrode assembly including the composite fiber assembly removes the fiber-forming component contained in the composite fiber and when the power is applied to two different electrodes, the electrode assembly including the ultra-small LED element connected to the two different electrodes. Since it can be implemented there is an advantage that can further improve the mass production in the reduction of manufacturing time.

In addition, the present invention is a base substrate; A plurality of electrodes formed on the base substrate; And a plurality of ultra-small LED elements positioned on the plurality of electrodes by being injected onto the plurality of electrodes as a composite fiber including a fiber forming component, and then removing the fiber forming component.

According to a preferred embodiment of the present invention, the plurality of microminiature elements are included in the composite fiber in at least one row in the longitudinal direction of the composite fiber, the composite fiber is put on the plurality of electrodes, the fiber of the composite fiber The removal of the forming components allows the plurality of micro LED elements to be positioned in at least one row on the plurality of electrodes, in which case the micro LED elements are self-aligned as they are aligned in line on the desired electrode prior to self alignment. There is an advantage of further improving the time alignment required and the positional alignment on the electrodes of the individual micro LED devices which are self-aligned. More preferably, the composite fiber may be a composite fiber in which a plurality of microminiature elements form a core portion, and a fiber forming component is formed in a core portion, and the fiber-forming component is introduced after the core sheath-type composite fiber of the above structure is put on an electrode. By this removal, the plurality of micro LED elements can be positioned in at least one row on the plurality of electrodes.

Claims (19)

1. (1) a composite fiber assembly comprising a composite fiber comprising a fiber forming component and a plurality of ultra-small LED devices; And

   (2) removing the fiber-forming component of the composite fiber; a method for disposing a micro LED device comprising an electrode assembly.
2. The method of claim 1,

   The composite fiber assembly has a shape of any one of a yarn, a woven fabric, a knitted fabric and a non-woven fabric.
3. The method of claim 1,

   And the plurality of microminiature elements are included in the composite fiber.
4. The method of claim 3,

   And said plurality of microminiature elements are arranged in at least one or more rows in the longitudinal direction of the composite fiber.
5. The method of claim 4, wherein the composite fiber

   A core portion in which a plurality of micro LED elements are arranged in a row; And

   Ultra-finished LED element, characterized in that it comprises a fiber-forming component formed around the core; disposed on the electrode assembly.
6. The method of claim 5,

   The diameter of the composite fiber is a method of placing a micro LED device in the electrode assembly, characterized in that 1.2 ~ 8.0 times the short length of the micro LED device.
7. The method of claim 3,

   And the plurality of micro LEDs are arranged in a plurality of rows in the longitudinal direction of the composite fiber.
8. The method of claim 1,

   The fiber forming component is selected from the group consisting of PMMA (Poly (methyl methacrylate), PS (polystyrene), PVC (polyvinyl chloride), PVA (polyvinyl acetate), PE (polyethylene), PET (Polyethylene terephthalate), PP (polypropylene) A method of disposing an ultra-small LED device in an electrode assembly, characterized in that it comprises at least one polymer compound.
9. The method of claim 1,

   The composite fiber is a method for placing a micro LED device in the electrode assembly, characterized in that it comprises 30 to 90 parts by weight of the ultra-small LED device with respect to 100 parts by weight of the fiber forming component.
10. The method of claim 1,

    The micro LED device has a rod shape, and the micro LED device has a length of 100 nm to 10 μm, wherein the micro LED device is disposed in the electrode assembly.
11. The method of claim 1, wherein the micro LED device

    A first conductive semiconductor layer;

    An active layer formed on the first conductive semiconductor layer; And

    And a second conductive semiconductor layer formed on the active layer.
12. The method of claim 11,

    The micro LED device may include a first electrode layer formed under the first conductive semiconductor layer; And a second electrode layer formed on the second conductive semiconductor layer, wherein the ultra-small LED device is disposed on the electrode assembly.
13. The method of claim 11,

    A method of disposing an ultra-small LED device in an electrode assembly, characterized in that the outer surface of the micro-LED device is coated with an insulating coating covering at least the entire outer surface of the active layer portion.
14. The method of claim 1,

    Wherein step (2) is a method of placing a micro LED device on the electrode assembly, characterized in that to remove the fiber-forming component by treatment of at least one of heat or solvent.
15. The method of claim 14,

    Wherein said solvent comprises at least one solvent selected from the group consisting of acetone, toluene and isopropyl alcohol.
16. A plurality of electrodes; And

    And a composite fiber assembly disposed on the plurality of electrodes, the composite fiber assembly including a composite fiber including a fiber forming component and a plurality of ultra-small LED devices.
17. Base substrate;

    A plurality of electrodes formed on the base substrate; And

    And a plurality of ultra-small LED elements positioned on the plurality of electrodes by being injected onto the plurality of electrodes as composite fibers including a fiber forming component and then removing the fiber forming component.
18. The method of claim 17,

    The plurality of microminiature elements are included in the composite fibers in at least one row in the longitudinal direction of the composite fibers,

    And after the composite fiber is put on the plurality of electrodes, the fiber forming component of the composite fiber is removed so that the plurality of micro LEDs are positioned in at least one row on the plurality of electrodes.
19. The method of claim 18,

    The plurality of microminiature elements are included in the composite fiber in a core shape having one or more rows formed therein with respect to a sheath formed of a fiber forming component,

    And after the composite fiber is put on the plurality of electrodes, the ultra-parts of the composite fiber are removed so that the plurality of micro LEDs are positioned in at least one row on the plurality of electrodes.

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