KR101723822B1 - Complex fiber for manufacturing ultra-small LED electrode assembly and fabric comprising thereof - Google Patents

Abstract

The present invention relates to a composite fiber including a very small LED element and a fabrication method thereof, and more particularly, to a composite fiber including a very small LED element at a desired electrode position in connection with a nanoscale ultra- And a very small LED element capable of mass production by shortening a manufacturing time required for arranging a very small LED element and improving convenience, and a fabric including the same .

Description

TECHNICAL FIELD [0001] The present invention relates to a composite fiber for manufacturing an ultra-small LED electrode assembly,

The present invention relates to a composite fiber including a very small LED element and a fabrication method thereof, and more particularly, to a composite fiber including a very small LED element at a desired electrode position in connection with a nanoscale ultra- And a very small LED element capable of mass production by shortening a manufacturing time required for arranging a very small LED element and improving convenience, and a fabric including the same .

In 1992, Nakamura of Nichia Corporation of Japan succeeded in fusing high quality monocrystalline GaN nitride semiconductors by applying a low-temperature GaN compound layer, which has been actively developed. An LED is a semiconductor having a structure in which an n-type semiconductor crystal in which a plurality of carriers are electrons and a p-type semiconductor crystal in which a plurality of carriers are holes are bonded to each other using the characteristics of compound semiconductors, And is converted into light to be displayed.

These LED semiconductors have a very low energy consumption due to high photoconversion efficiency, have a semi-permanent and environmentally friendly life, and are called the revolution of light as a green material. In recent years, the development of compound semiconductor technology has led to the development of high-brightness red, orange, green, blue, and white LEDs that are used in many fields, such as traffic lights, cell phones, automotive headlights, outdoor display panels, LCD backlight units And it has been actively researched at home and abroad. In particular, GaN compound semiconductors having a wide band gap are materials used for manufacturing LED semiconductors emitting green, blue, and ultraviolet light, and a white LED device can be manufactured using a blue LED device. .

On the other hand, in order to utilize the LED element in illumination, display, etc., an LED element and an electrode capable of applying power to the element are required, and the application purpose, the space occupied by the electrode, The placement of the two electrodes has been studied extensively.

The research on the arrangement of the LED element and the electrode can be classified into growing the LED element on the electrode and separately growing the LED element separately and placing it on the electrode.

First, research on growing an LED element on an electrode has been carried out in such a manner that a lower electrode is thinned on a substrate, an n-type semiconductor layer, an active layer, a p-type semiconductor layer and an upper electrode are sequentially stacked on the substrate, There is a bottom-up method in which an LED element and an electrode are simultaneously formed and arranged in a series of manufacturing processes through a method of laminating an upper electrode after etching the layers.

Next, a method in which the LED elements are independently grown separately and then disposed on the electrodes is a method of disposing each LED element independently grown on a patterned electrode by a separate process.

The former method has a problem that crystallization of highly crystalline / high-efficiency thin film and LED element is very difficult, and the latter method has a problem that the light extraction efficiency is lowered and the luminous efficiency is lowered.

In the case of the latter method, a three-dimensional LED element can be manually or mechanically connected to the electrode one by one if it is a conventional size LED element. However, if the LED element is a small-sized nano unit, There is a problem that it is difficult to arrange a very small LED element on a nanoscale electrode and to connect an arranged very small LED element to an electrode.

Specifically, Korean Patent Application No. 2013-0080427 was invented by the inventor of the present invention in order to solve the problem according to the latter method, and more specifically, Fig. 1 shows the micro-LED device disclosed in the above- 1A, a micro-LED device 120 is manufactured by independently growing a micro-LED device 120 as shown in FIG. 1A. The micro-LED device 120 includes a solvent 140 and a nanoscale miniature electrode As shown in FIG. 1B, power is applied to two different electrodes 110 and 130 to self-align the micro-LED devices to connect the two micro-electrodes to each other, as shown in FIG. 1C .

This can overcome the difficulties of the related art that it is difficult to connect the ultra-small LED element to two different very small electrodes. However, as the ultra-small LED element is injected into the electrode in a solution state, There is a problem that the number of the ultra-small LED elements arranged in the target electrode region is significantly reduced as the ultra-small LED element is spread out. Such a problem is disadvantageous in that the performance of the illumination and display to be realized by incorporating the ultra-small LED element is significantly lowered, and the ultra-small LED element must be injected into the electrode in a solution state, which is unsuitable for mass production.

In addition, in order to solve the above problems, it is possible to increase the number of ultra-small LED elements arranged in the target electrode area by repeatedly injecting the solution containing the ultra-small LED element, Resulting in a significant increase in cost and inadequate in mass production.

Accordingly, the miniature LED element can be more easily arranged in the desired electrode area of the miniature electrode, and even after the element is disposed on the electrode, the miniaturized LED element does not spread outside the target electrode area, In order to make it easier to connect to the system.

SUMMARY OF THE INVENTION The present invention has been conceived to solve the above-mentioned problems, and it is an object of the present invention to provide a method of manufacturing a light emitting diode, in which a very small LED element can be more easily arranged in a desired electrode area of a very small electrode, It is possible to more easily connect the ultra miniature LED device to the target electrode area, significantly reduce the arrangement time of the miniature LED device on the electrode, improve the arrangement convenience, and enable mass production The present invention relates to a composite fiber including a very small LED element that can be applied to a product such as an LED lamp and an LED display of high quality by significantly increasing the number of ultra small LED elements disposed in a target electrode region and a fabric including the same.

In order to solve the above-mentioned first problem, the present invention provides a fiber forming composition comprising: a fiber forming component; And a plurality of ultra-small LED elements included in the fiber forming component.

According to a preferred embodiment of the present invention, the composite fibers may be arranged such that a plurality of ultra-small LED elements have at least one row in the longitudinal direction of the composite fibers.

According to another preferred embodiment of the present invention, the composite fiber comprises: a core portion formed by rowing a plurality of ultra-small LED elements in a row; And a fiber-forming component that is formed by wrapping 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, and more preferably 1.2 to 6.0 times, the minor axis length of the ultra-small LED element.

According to another preferred embodiment of the present invention, the composite fibers may be arranged such that a plurality of ultra-small LED elements are arranged in a plurality of rows in the longitudinal direction of the composite fibers.

According to another preferred embodiment of the present invention, the fiber forming component is a polymer compound which is removed by heat; And

A polymer compound which is removed by at least one solvent selected from the group consisting of acetone, toluene, chloroform and isopropyl alcohol; Or the like.

According to another preferred embodiment of the present invention, the polymer compound to be removed by the solvent is selected from the group consisting of poly (methyl methacrylate), PVA (polyvinyl alchol) PS (polystyrene), PVC (polyvinyl chloride) And at least one polymer compound selected from the group consisting of

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 element per 100 parts by weight of the fiber forming component.

According to another preferred embodiment of the present invention, the ultra miniature LED device may be in the form of a rod.

According to another preferred embodiment of the present invention, the ultra miniature LED device includes 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.

According to another preferred embodiment of the present invention, the ultra miniature LED device comprises: a first electrode layer formed under the first conductive semiconductor layer; And a second electrode layer formed on the second conductive semiconductor layer.

According to another preferred embodiment of the present invention, the outer surface of the ultra miniature 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, the outer surface of the insulating coating may be coated with a hydrophobic coating.

According to another preferred embodiment of the present invention, the length of the ultra miniature LED device may be 100 nm to 10 탆.

In order to solve the second problem, the present invention provides a fabric comprising the composite fiber according to the present invention as at least one of warp or weft.

The composite fiber including the ultra-small LED element of the present invention is advantageous in that it can more easily arrange the ultra-small LED element in the target electrode area of the ultra-small electrode compared to when the ultra- The ultra miniature LED device can be easily connected to the target electrode area by preventing the ultra miniature LED device from spreading to other than the target electrode area even after the ultra miniature LED device is disposed on the electrode, The present invention can be widely applied to products of high quality LED lamp, LED display and the like by significantly increasing the number of ultra-small LED elements arranged in a target electrode area while enabling mass production by remarkably reducing the time.

1 is a schematic view showing a manufacturing process of self-aligning a micro-LED element to an electrode.
2 is a perspective view of a composite fiber according to a preferred embodiment of the present invention.
3 is an optical microphotograph showing an ultra-small LED element placed on an electrode after putting the ultra-small LED element in a solvent and putting it on an electrode.
4 is a perspective view of a composite fiber according to a preferred embodiment of the present invention.
5 is a plan view of a micro LED electrode assembly in which a micro LED device is self-aligned on an electrode through a composite fiber according to a preferred embodiment of the present invention.
6 is a perspective view of a composite fiber according to a preferred embodiment of the present invention.
7 is a cross-sectional perspective view of a composite fiber according to a preferred embodiment of the present invention.
8 is a perspective view of a very small LED element included in a preferred embodiment of the present invention.
9 is a vertical cross-sectional view of a conventional microelectrode assembly.
10 is a plan view and a vertical cross-sectional view of a micro LED electrode assembly in which a micro LED is connected to a first electrode and a second electrode through a composite fiber according to a preferred embodiment of the present invention.
11 is a cross-sectional view of a dual-coherent spinneret used in the fabrication of a conjugate fiber according to a preferred embodiment of the present invention.
12 is a cross-sectional perspective view of a sea-island fiber made according to a preferred embodiment of the present invention.
13 is a plan view of a fabric comprising a composite fiber according to a preferred embodiment of the present invention.
FIG. 14 is a schematic view illustrating a fabrication process of connecting an ultra-small LED device to an electrode using a fabric according to a preferred embodiment of the present invention.

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

As described above, in order to connect the ultra-small LED element to the ultra-small electrode as described above, the ultra-small LED element is placed in a solvent and put into the electrode so as to place the ultra-small LED element on the electrode. There is a problem in that the number of very small LED elements arranged in a target electrode region is significantly reduced as the very small LED element is spread out into an electrode region other than the electrode region to which the very small LED element is to be connected. In addition, such a problem has a problem in that the performance of the illumination and display to be realized by incorporating the ultra-small LED element is remarkably lowered, and the ultra-small LED element must be injected into the electrode in a solution state, which is unsuitable for mass production. Further, in order to solve the above-mentioned problems, it is possible to increase the number of ultra-small LED elements arranged in the target electrode area by repeatedly injecting the solution containing the ultra-small LED element, Resulting in a remarkable increase in cost and inadequate in mass production.

Accordingly, in the present invention, a high fiber forming component; And a plurality of ultra-small LED elements included in the fiber forming component. The present invention has been made to solve the above-mentioned problems. Accordingly, it is possible to more easily arrange the ultra-small LED element in the target electrode region of the ultra-small electrode, and even after the element is disposed on the electrode, the ultra-small LED element does not spread out to the target electrode region, It is possible to more easily connect to the electrode region, to significantly reduce the arrangement time of the miniature LED element on the electrode, to enable mass production, and to significantly increase the number of ultra-small LED elements arranged in the target electrode region.

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 ultra-small LED elements 20, The element 20 is contained within the fiber forming component 10.

First, the fiber forming component included in the conjugate fiber according to the present invention will be described.

The fiber forming component serves as a support for supporting a plurality of ultra-small LED elements contained therein, so that it is possible to provide easier accessibility than arranging the ultra-small LED elements in an aimed electrode region, It is easier to handle than the case of managing in a solution state, and since it is easy to dispose a very small LED element in a desired electrode area of a very small electrode line having a large area, it can be more advantageous for mass production and realization of an electrode assembly with a large area .

Conventionally, a very small LED element is placed in a solvent in a solution state when it is placed on a very small electrode. At this time, the ultra-small LED element is floated without a certain direction in the solution, There is a problem in that, even after the application of the solution, the ultra-miniaturized LED element is disposed outside the target electrode region or the edge portion of the target electrode region even though the electrode region is intended to be disposed.

Specifically, FIG. 3 is an optical micrograph showing an ultra-small LED element disposed on an electrode after putting the ultra-small LED element into a solvent and putting it on an electrode. As shown in FIG. 3, in the ultra-small LED element, It can be confirmed that it is concentrated on the non-edge portion. Therefore, the inventor of the present invention has been studying to overcome the above-mentioned problems. In order to solve the above problems, the inventors have found that when a very small LED element is disposed in a target electrode region in a support, So that it is possible to more easily arrange the ultra-small LED element in the target electrode region, leading to the present invention.

Accordingly, the fiber forming component can be used without limitation as long as it can function as a support by supporting a plurality of ultra-small LED elements. Preferably, the thermoplastic polymer compound is removed by heat. And / or a polymer compound which is removed by at least one solvent selected from the group consisting of acetone, toluene, chloroform and isopropyl alcohol; The thermoplastic polymer compound removed by the heat may have a melting point of 50 to 400 ° C, more preferably 50 to 300 ° C. As a non-limiting example, the thermoplastic polymer compound may include at least one of PMMA One or more polymer compounds such as poly (methyl methacrylate), PS (polystyrene), PVC (polyvinyl chloride), PVA (polyvinyl acetate), PE (polyethylene), PET (polyethylene terephthalate) The polymer compound dissolved by the solvent may include at least one polymer selected from the group consisting of poly (methyl methacrylate) (PMMA), polystyrene (PS), PVC, and PVA.

As the fiber forming component, a polymer compound which can function as a support and is removed by heat or a solvent is more preferable. In order to connect the ultra-small LED device to the electrode after the composite fiber is disposed on the electrode, Is required. Accordingly, it is particularly preferable to use a polymer compound which can be easily dissolved by heat and / or a solvent. By this, the time required for disposing the composite fiber on the electrode, removing the fiber forming component and positioning the ultra- Can be significantly reduced.

On the other hand, in the case of a polymer compound in which the fiber forming component is removed by a solvent, there is an advantage that the removal of the fiber forming component and the self-alignment of the ultra-small LED element can be performed simultaneously through a single solvent injection. Specifically, the reason why the ultra miniature LED device 120 is included in the solvent 140 and injected into the electrodes 110 and 130 in FIG. 1A is that since the micro LED device has little mobility in the absence of a solvent, Because. 1B, when the electrodes 110 and 130 are supplied with power, the outer surface of the micro-LED 120 is symmetric with respect to the longitudinal center of the micro-LED according to the electric field induction, So that a polarization is formed. If there is no solvent, a very small LED element having a polarized outer surface of a device moves to two electrodes having different potentials due to an electrostatic attraction, and is very difficult to be self-aligned and connected to an electrode. Therefore, In order to improve the self-alignment, a mobile phase such as a solvent is required. If a fiber-forming component is a polymer compound dissolved by a solvent, when a solvent is added to the conjugate fiber, the fiber-forming component is dissolved in a solvent to form a solution, Can function as a mobile phase capable of self-alignment by moving a very small LED element disposed on the electrode, so that the miniaturized LED element can be self-aligned and connected to the electrode without removing a fiber forming component and without introducing a solvent .

Next, a plurality of ultra-small LED elements included in the above-mentioned fiber forming component included in the composite fiber according to the present invention will be described.

First, the plurality of ultra-small LED elements are located inside the fiber forming component and are included in the composite fiber.

2, the ultra-small LED element 20 is located inside the fiber forming component 10, and if the ultra-small LED element 20 is not located inside the fiber forming component 10, When exposed to the outer surface of the forming component 10, there is a possibility of damaging the outer surface of the miniature LED element during storage, movement and handling of the conjugate fiber, and damage to the outer surface of the miniature LED element may significantly reduce the light extraction efficiency There is a possibility that a product whose quality is deteriorated can be implemented. Accordingly, the ultra-small LED element should be located inside the fiber forming component.

However, it is preferable that the plurality of ultra-small LED elements are arranged in the longitudinal direction of the conjugate fiber in order to improve arrangement and alignment of the ultra-small LED elements which are disposed on the electrodes after the composite fibers are disposed on the electrodes and after the fiber- And may be included in the composite fibers arranged in at least one row.

More specifically, FIG. 4 is a perspective view of a composite fiber according to a preferred embodiment of the present invention, wherein the composite fiber 30B includes a fiber forming component 10 and a plurality of ultra-small LED elements 20, 10 are arranged in the composite fiber with the first row P ₁ and the second row P _{2 in} the longitudinal direction of the composite fiber. When the composite fiber 30B is disposed on the electrode, the ultra-small LED element 20, which is left on the electrode after the fiber forming component 10 is removed, is vertically adjacent to two different electrodes in the longitudinal direction of the element When the power is applied to the electrode through the miniature LED device, the micro LED device moves the minimum moving distance until it is connected to the electrode, and at the same time, the number of the ultra-small LED devices that can be connected to the electrode in a certain electrode area Increase.

Specifically, FIG. 5 is a plan view of a micro LED electrode assembly in which a micro LED device is self-aligned on an electrode through a composite fiber according to a preferred embodiment of the present invention. As shown in FIG. 2, When the composite fibers 30A in which the ultra-small LED elements 20 are arranged are used, the ultra-small LED elements remaining on the electrodes after the fiber forming component is removed can also be randomly arranged without any directionality on the electrodes, 5, the micro LED device 20 'is connected to two electrodes 110 and 130, which are different from each other. Therefore, the micro LED device 20' There is a problem in that the number of optical fibers is reduced.

According to a preferred embodiment of the present invention, in order to further improve the arrangement and alignment of the ultra-small LED elements remaining on the electrode after the fiber forming component is removed and to facilitate removal of the fiber forming component, The fiber comprises a core portion formed by rowing a plurality of ultra-small LED elements in a row; And a core part formed by wrapping the core part with a fiber forming component.

6 is a perspective view of a composite fiber according to a preferred embodiment of the present invention. The composite fiber 30C shown in FIG. 6 includes a core portion formed by arranging a plurality of micro LED elements 20 in a row in a row P ₃ , And the fiber forming component 10 includes an initial portion formed by surrounding the core portion.

The composite fiber 30C as shown in FIG. 6 has a structure in which when a plurality of ultra-small LED elements in the composite fiber 30B as shown in FIG. 4 are removed as compared with the composite fiber 30B in which two rows are arranged, It may be easier to arrange the arrangement of the remaining ultra-small LED elements than to arrange them perpendicular to the two different electrodes.

The composite fiber 30B shown in Fig. 4 has a larger diameter than that of the composite fiber 30C shown in Fig. 6, and the area of the remaining fiber forming components except for the ultra-small LED element in the cross- It may require more removal time and / or more removal solvent and the like to remove the fiber forming component in order to place the ultra-small LED element on the electrode.

In the case of the core-sheath type conjugate fiber as described above, the diameter (a in FIG. 6) is preferably 1.2 to 8.0 times, more preferably 1.2 to 6.0 times the minor axis length of the ultra-small LED element (b in FIG. 6). Thus, the ultra-small LED element can be included without being exposed to the outer surface of the composite fiber, and the advantages of shortening the removal time of the fiber forming component and reducing the amount of removing solvent can be obtained.

According to another preferred embodiment of the present invention, in order to increase the number of the ultra-small LED elements disposed on the electrodes before the ultra-small LED elements are self-aligned and connected to the electrodes, the plurality of ultra- And may be arranged by arranging a plurality of rows in a direction. 7 is a perspective view of a composite fiber according to a preferred embodiment of the present invention. As shown in FIG. 7, a plurality of very small LED elements 21, 22, 23 in the composite fiber 30D are arranged in five rows, It is possible to arrange the arrangement of the ultra-small LED elements remaining on the electrode to be close to perpendicular to the two different electrodes while removing the fiber forming component 10, There is an advantage that the number of very small LED elements can be remarkably increased.

Next, a micro-sized LED element included in the fiber forming component in various embodiments as described above 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 an ultra-small LED device generally used for illumination or display, etc. Preferably, the length of the ultra-small LED device can be 100 nm to 10 탆, Lt; RTI ID = 0.0 > 5 < / RTI > If the length of the ultra-small LED element is less than 100 nm, it is difficult to manufacture a highly efficient LED element. If the length is more than 10 탆, the efficiency of the LED element may be reduced. Further, the diameter of the ultra-small LED element may preferably be 100 nm to 5 占 퐉. The shape of the ultra-small LED element may be a rod shape, and may be various shapes such as a cylinder and a rectangular parallelepiped, and may be a columnar shape, but the present invention is not limited thereto.

Hereinafter, in the description of the ultra-small LED device, the terms "upper", "lower", "upper", "lower", "upper" .

First, according to a preferred embodiment of the present invention, the ultra-small LED element includes 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.

More specifically, FIG. 8 is a perspective view of a very small LED device included in a preferred embodiment of the present invention, which includes a first conductive semiconductor layer 20b, an active layer 20c formed on the first conductive semiconductor layer 20b, And a second conductive semiconductor layer 20d formed on the second conductive semiconductor layer 20c.

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. The n-type semiconductor layer may be formed of In _x Al _y Ga _1-xy N (0 = x = 1, 0 = y = 1, 0 = x + y = 1) And the first conductive dopant (e.g., Si, Ge, Sn, etc.) may be doped. The first conductive dopant may be selected from the group consisting of InAlGaN, GaN, AlGaN, InGaN, AlN and InN. The thickness of the first conductive semiconductor layer 20b may be 500 nm to 5 占 퐉, but is not limited thereto. Since the light emission of the ultra-small LED is not limited to blue, there is no limit to the use of other kinds of III-V semiconductor materials as the n-type semiconductor layer when the emission colors are different.

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

When the ultra-small 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 below 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 be used as the active layer 20c. In the active layer 20c, when an electric field is applied, light is generated due to the combination of electron-hole pairs. 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 varied depending on the type of the LED. Since the emission of the ultra-small LED is not limited to blue, there is no limitation in using other kinds of III-V semiconductor materials as the active layer when the emission colors are different.

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

When the very 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 is formed of at least one p-type semiconductor layer The p-type semiconductor layer may be a semiconductor material having a composition formula of In _x Al _y Ga _{1 -x- y} N (0 = x = 1, 0 = y = 1, 0 = x + y = 1) At least one of InAlGaN, GaN, AlGaN, InGaN, AlN, InN, and the like may be selected, and a second conductive dopant (e.g., 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 a minimum component, and another phosphor layer above / below each layer, 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 is not limited thereto. Since the light emission of the ultra-small LED is not limited to blue, there is no limitation in using other types of III-V semiconductor materials as the p-type semiconductor layer when the emission colors are different.

In addition, according to a preferred embodiment of the present invention, the ultra miniature LED device may further include a first electrode layer formed under the first conductive semiconductor layer and a second electrode layer formed over the second conductive semiconductor layer.

More specifically, FIG. 8 is a perspective view illustrating an exemplary embodiment of an ultra-miniaturized LED device according to the present invention. In FIG. 8, a first electrode layer 20a and a second conductive semiconductor layer 20d, which are formed under the first conductive semiconductor layer 20b, And the second electrode layer 20e formed.

The first electrode layer 20a and the second electrode layer 20e may be made of a metal or a metal oxide used as an electrode of a conventional LED element. Preferably, the first electrode layer 20a and the second electrode layer 20e may be formed of chromium (Cr), titanium (Ti) (Al), gold (Au), nickel (Ni), ITO, oxides or alloys thereof, or the like may be used alone or in combination. Preferably, the thickness of the first electrode layer 20a and the thickness of the second electrode layer 20e may be 1 to 100 nm, but are not limited thereto. When the first electrode layer 20a and the second electrode layer 20e are included in the ultra-small LED element, the first conductive semiconductor layer 20b and / or the second conductive semiconductor layer 20d may be formed of metal oxide There is an advantage that a metal ohmic layer can be formed at a temperature lower than the temperature required in the step of forming the micromechanical layer.

On the other hand, the outer surface of the ultra-small LED element 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 that occurs when the active layer 20c included in the ultra-small LED element contacts the electrode. In addition, the insulating coating 20f protects the outer surface of the device including the active layer 20c and the semiconductor layer of the ultra-small LED element, thereby preventing a decrease in the luminous efficiency of the ultra-small LED element.

Specifically, in FIG. 8, the insulating coating 20f is coated on the outer surface of the micro-LED element including the outer surface of the active layer 20c. In order to further prevent electrical short circuiting and to prevent the durability and light extraction efficiency of the ultra miniature LED device due to damage to the outer surface of the semiconductor layer, the insulating film 20f may be formed on the first semiconductor layer 20b and the second semiconductor layer 20b, The insulating coating 20f may be coated on any one or more of the insulating film 20d. However, when the electrical short circuit occurs, a fatal problem that the micro LED device can not even emit light may occur. Therefore, at least the outer side of the active layer 20c is formed on the outer surface of the micro LED device 20, The insulating coating 20f covering the entire surface can be coated.

The reason why the electrical short circuit is caused is that it is difficult to manually or automatically arrange and connect the nanosubstantially miniature LED devices to different miniature nano-sized electrodes. In order to solve the disadvantages of arrangement and connection of such a very small LED device, the inventor of the present invention used a method of applying power to different electrodes and self-aligning the very small LED device at one time to connect them to electrodes. However, In this process, the active layer 20c of the ultra-small LED device contacts the electrode line and the active layer 20c is connected to the electrode, Short circuiting can occur frequently.

On the other hand, in the case where a very small LED element is erected upright on an electrode by a method of mounting an ultra-small LED element on an electrode and another electrode is arranged on the element, there is a problem of electric short- May not occur. That is, since the ultra-small LED element can not be erected upright on the electrode, the active layer can contact the electrode line only when the LED element is laid on the electrode. In this case, the ultra-small LED element can not be connected to two different electrodes There is a problem that the device can not be electrically connected to two different electrodes, and the problem of electrical short-circuiting may not occur. Specifically, FIG. 9 is a vertical cross-sectional view of a conventional micro-electrode assembly. The first semiconductor layer 71a of the first ultra-small LED element 71 is in communication with the first electrode line 61, 71c are in communication with the second electrode line 62 and the first ultra miniature LED element 71 is in an upright position and communicated with the two electrodes 61, 62 located at the upper and lower sides. In the electrode assembly shown in FIG. 9, if the first ultra-small LED element 71 is simultaneously connected to the two electrodes, the active layer 71b of the element is not likely to contact any one of the two electrodes 61 and 62 An electrical short circuit due to contact between the active layer 71b and the electrodes 61 and 62 may not occur.

9, the second ultra-small LED element 72 is laid on the first electrode 61. In this case, the active layer 72b of the second ultra-small LED element 72 is in contact with the first electrode 61 At this time, there may be a problem of electrical communication between the second ultra-small LED element 72 and the first electrode 61 and the second electrode 62, which is not a problem of electrical short circuit. If the insulating layer is coated on the outer surfaces of the first semiconductor layer 71a, the active layer 71b and the second semiconductor layer 71c of the first ultra-small LED element 71, It is possible to have only the object and effect of reducing the luminous efficiency through prevention of damage to the outer surface, and does not have the effect of preventing electric short circuit.

However, in the composite fiber according to the present invention, unlike the conventional miniature electrode assembly shown in FIG. 9, the miniature LED device is used to connect the miniature LED device to the two different electrodes in a laid- It is inevitable that an electrical short circuit due to the contact and / or connection between the active layer and the electrode of the ultra-small LED element which has not occurred in the ultra-small electrode assembly of the present invention necessarily occurs. Accordingly, in order to prevent this, the outer surface of the ultra-small LED element may include an insulating coating covering at least the entire outer surface of the active layer portion.

Furthermore, in an ultra-small LED device having a structure in which a first semiconductor layer, an active layer, and a second semiconductor layer are sequentially arranged vertically, as in the case of a micro LED device according to a preferred embodiment of the present invention, none. In addition, in the LED device having such a structure, the position of the active layer is not located in the center in the longitudinal direction of the device, but may be biased toward the specific semiconductor layer, so that the possibility of contact between the electrode and the active layer can be further increased. Therefore, the miniature LED device including the insulating coating coated over the entire outer surface of the active layer portion to prevent contact between the electrode and the active layer has a merit advantageous in light emission by being connected to the electrode without electrical short circuit.

10 is a plan view and a vertical cross-sectional view of a micro LED electrode assembly in which a micro LED is connected to a first electrode and a second electrode through a composite fiber according to a preferred embodiment of the present invention. 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 largely shifted to the left as shown in the sectional view AA in FIG. Is likely to come into contact with the electrode 111, so that an electrical short circuit may occur, which may cause a failure of the miniature LED electrode assembly. In order to solve the above problems, the ultra miniature LED device according to the present invention can be coated with an insulating coating on the outer circumference including the active layer. Due to the insulating coating, as in the first ultra miniature LED device 121 of FIG. 10, A short circuit may not occur even if the electrode 121b covers the electrode.

The insulating film (20f) are of preferably 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₎ And may include any one or more of the above components, more preferably, the above components but may be transparent, but are not limited thereto. In the case of a transparent insulating coating, the insulating coating 20f serves as the above-described insulating coating, and coating of the insulating coating can minimize the reduction in the luminous efficiency which may occur.

However, according to a preferred embodiment of the present invention, the insulating coating 20f may not be coated with an insulating coating on at least one of the first electrode layer 20a and the second electrode layer 20e of the ultra-small LED element, More preferably, both the electrode layers 20a and 20e may not be coated with an insulating coating. This is because the two electrode layers 20a and 20e must be in electrical communication with each other. If the two electrode layers 20a and 20e are coated with the insulating coating 20f, the electrical communication may be interrupted, There is a problem that the light emission itself may not be attained because it is not reduced or electrically communicated. However, since there is no problem when the two electrode layers 20a and 20e are electrically connected to each other, the insulating coating 20f can prevent the first electrode layer 20a and the second electrode layer 20e of the ultra- May be included in portions of the first electrode layer 20a and the second electrode layer 20e except for a portion (for example, an end portion of the electrode layer).

Meanwhile, according to a preferred embodiment of the present invention, the ultra miniature LED device may include a hydrophobic film coated on the outer surface of the insulation film of the ultra-small LED device in order to prevent aggregation between the devices.

Specifically, in FIG. 8, the hydrophobic coating 20g coated on the outer periphery of the insulating coating 20f can be identified. The hydrophobic coating 20g has a hydrophobic property on the surface of the ultra-small LED element to prevent aggregation between the LED elements. When fabricating the composite fiber by spinning together with the fiber forming component in the ultra-small LED element, It may be more advantageous to minimize the aggregation between the fibers so that the fibers can be aligned and arranged in the composite fibers without being agglomerated. In addition, there is a problem that it is difficult to move and align the ultra-small LED elements on the electrode line when the ultra-small LED elements remain on the electrode after the fiber forming component is removed from the composite fiber. The hydrophobic film removes such problems The micro-LED element can be self-aligned to the electrode line.

The hydrophobic coating 20g can be formed on the insulating coating and can be used without limitation as long as it can prevent aggregation between the ultra-small LED elements. Preferably, octadecyltrichlorosilane (OTS) Self-assembled monolayers (SAMs) such as fluoroalkyltrichlorosilane, perfluoroalkyltriethoxysilane and the like, and fluoropolymers such as teflon and Cytop. ) May be used alone or in combination, but the present invention is not limited thereto.

As described above, according to a preferred embodiment of the present invention, the fiber forming component and the ultra-small LED element included in the composite fiber may include the ultra-small LED element in an amount of 30 to 90 parts by weight based on 100 parts by weight of the fiber forming component. If the ultrafine LED element is contained in an amount of less than 30 parts by weight with respect to the fiber forming component, the number of ultra-small LED elements included in the composite fiber unit volume is small, A large amount of composite fibers may be required to feed a larger number of ultra-small LED elements, and as the amount of the composite fibers increases, the process cost and the removal time of the fiber forming component increase, There may be a problem of degradation. If the amount is more than 90 parts by weight, the number of ultrafine LED elements that can be included per unit volume of the composite fiber may increase, but the spacing between the ultrafine LED elements in the composite fiber becomes short and in some cases, There is a possibility that the contact between the devices frequently occurs and the outer surface of the device is easily damaged and the micro LED device is exposed to the outer surface of the fiber to accelerate the damage of the outer surface of the device.

Hereinafter, a method for producing a composite fiber including the ultra-small LED element according to the present invention will be described.

However, the manufacturing method described below is only one embodiment, and the present invention is not limited to the description of the manufacturing method described later.

The method for producing the conjugate fiber according to the present invention can be carried out by a conventional method for producing fibers, and specifically, it can be carried out by chemical spinning or electrospinning, and the chemical spinning specifically includes melt spinning, wet spinning, , Dry-wet spinning, and the like. The composite fiber according to the present invention can be manufactured by selecting and modifying an appropriate one of the above spinning methods in consideration of the specific kind of the fiber-forming component to be used, the diameter of the desired composite fiber, and the like.

A method for producing a conjugate fiber according to the present invention will now be described with reference to a method for producing a conjugate fiber including an ultra-small LED element by melt spinning in chemical spinning.

Firstly, in step (1), a spinning solution containing the ultra-small LED element can be manufactured.

The spinning solution may be prepared by mixing the ultrafine LED device after making the fiber forming component into a solution state by melting and / or dissolving the fiber forming component.

In addition, the spinning solution can be prepared from the first spinning solution and the second spinning solution in accordance with the shape of the spinneret to be used and the shape of the composite fiber. 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 incorporating the ultra-small LED element in a solvent such as acetone, The device can be produced by incorporating the second fiber-forming component into a molten and / or dissolved solution. The melting temperature of the fiber-forming component or the solvent may be determined in consideration of the fiber-forming component to be used, and is not particularly limited in the present invention.

The spinning solution may be separately prepared before being injected into a spinner, and may be added to a spinner or a hopper contained in a conventional spinner, a fiber forming component may be introduced into the hopper, and the ultra-small LED component may be mixed with the melted fiber forming component. Can be prepared by a known method. At this time, the intrinsic viscosity of the spinning solution may be determined in consideration of ease of spinning, preferably 0.1 to 2.0 cps, more preferably 0.1 to 1.2 cps, There is an advantage in that the shape stability of the composite fiber after spinning can be maintained. However, the intrinsic viscosity can be changed according to the type of fiber forming component used, the type of radiator used, and the design of the detachment.

Next, in step (2), the composite fiber can be prepared by spinning the spinning solution prepared above.

In the case of the spinneret used for spinning solution spinning, a spinneret having a single tubular spinning nozzle can be used to produce the composite fiber 30A as shown in FIG. 2. However, as shown in FIG. 6, Fig. 11 is a perspective view of a duplex tubular spinning nozzle 5 used in the production of a conjugate fiber according to a preferred embodiment of the present invention. Fig. (1) is discharged into the outer tube 2 of the double tubular spinning nozzle 5, and the inner tube 1 is provided with the second spinning solution of the second spinning solution of the step (1) The spinning solution can be discharged. However, the composite fiber as shown in FIG. 6 can be manufactured through a single tubular spinning nozzle when adjusting the diameter of the nozzle in a single tubular spinning nozzle, and can not necessarily be manufactured through a double tubular spinning nozzle. As described above, the conjugated fibers injected through the nozzle may be short fibers or filament yarns, and the number of filaments of the filament yarns may vary depending on the nipping, so that the present invention is not particularly limited thereto.

The composite fibers emitted through the step (2) may further be subjected to a partial stretching or stretching process to improve the strength of the fibers and further align the arrangement of the ultra-small LED elements contained in the composite fibers in the fiber length direction . A specific method of the stretching or the partial stretching can be performed by a method known in the art and is not particularly limited in the present invention.

On the other hand, the diameter of the composite fiber according to the present invention manufactured through the above-described method may preferably be 200 nm to 15 탆. However, in order to produce the composite fiber of micro or nano unit, the composite fiber according to the present invention may be produced by using the electrospinning method in the art or by preparing a sea water-type fiber in the case of the chemical spinning method and then removing the sea component .

In the case of the electrospinning method, as in the above-described step (1), the conjugate fiber can be produced through two kinds of spinning liquids and two nozzles, or through one spinning solution and one nozzle, The diameter of the nozzle can be changed in consideration of the length of the major axis or the minor axis of the ultra-small LED element included in the spinning solution. The distance between the tip and the collector during electrospinning and the voltage are determined by the kind of the fiber- , The diameter of the composite fibers, and the like, and is not particularly limited in the present invention, and a specific electrospinning method can be used in the art.

Next, as a method for producing sea-island fibers and producing composite fibers by chemical spinning, a spinning solution containing a heterogeneous polymer compound, which is different from the fiber-forming component, is spun as a sea component, It can be manufactured by spinning a spinning solution containing a very small LED element. Specifically, Figure 12 may, as a cross-sectional perspective view of the even type fibers (30E) prepared according to example preferred embodiments of the present invention type fibers (30E) is island component (30C _1, 30C _2, 30C ₃ and a sea component 40. The island component 30C ₁ includes a fiber forming component 10 and an ultra miniature LED device 20.

The sea component 40 of such a sea-island fiber 30E may be a conventional alkali-soluble copolymer in the art that can be dissolved by a solvent (e.g., an alkali solution) that is difficult to dissolve the fiber forming component . When the sea-island fiber 30E thus produced is treated with a solution such as alkali to remove the sea component 40, the composite fibers 30C ₁ , 30C ₂ , 30C < / RTI > ₃ ).

Meanwhile, the present invention includes a nonwoven fabric comprising a composite fiber according to the present invention, which can be manufactured by the above-described method, in a fabric containing at least one of warp and weft or composite fiber according to the present invention.

First, the fabric may be a fabric woven by weaving the composite fiber according to the present invention in at least one of warp and weft, or knitted fabric including the composite fiber according to the present invention as a yarn.

The weaving may be performed by any one method selected from the group consisting of plain weave, twill weave, water weave, and double weave.

If the plain weave, twill weave, and water weave are three-dimensional tissue, the specific weaving method of each of the three-dimensional tissue is determined by a conventional weaving method, and it is possible to modify the tissue based on the three- There are, for example, changing jobs, changing jobs, changing jobs, changing jobs, changing jobs, non-working jobs, and twisting jobs. .

The double yarn is a method of weaving a fabric in which either one of warp yarns or weft yarns is doubled or both yarns are doubled. The specific method may be a conventional double yarn weaving method.

However, the present invention is not limited to the base fabric of the above-mentioned fabric, and is not particularly limited in the case of the warp yarn density in weaving.

The knitting can be performed by a method of stitch knitting or knitting, and a specific method of stitch knitting and knitting can be performed by a conventional knitting method of knitting or knitting.

13 is a plan view of a fabric including a composite fiber according to a preferred embodiment of the present invention. The fabric of FIG. 13 includes a plurality of micro-LED elements 20 and a composite fiber 10 including a fiber- 30) is woven as a weft (or inclined) weave in plain weave. The yarn 50 other than the conjugate fibers 30 included in the fabric may be a yarn containing a polymer compound that can be easily removed by the same method as the fiber forming component 10 included in the conjugate fiber 30 And may comprise a homogeneous or heterogeneous compound with the fiber forming component.

Specifically, FIG. 14 is a schematic view illustrating a fabrication process of connecting an ultra-miniature LED device to an electrode using a fabric according to a preferred embodiment of the present invention.

14A is a cross-sectional view illustrating a state in which composite fibers 310, 320, and 330 having a plurality of micro-LED elements 310b and 320b arranged in a row are arranged in a fiber formation component 310a and 320a in a weft And a step of positioning the yarn 310 ', 320' containing the same polymer compound as the fiber forming component in a warp (or weft) on the first electrode 301 and the second electrode 302 . Then, when a solvent (for example, water) capable of dissolving the fiber forming components 310a and 320a and the yarns 310 'and 320' is charged into the upper portion of the fabric, the fiber forming components 310a and 320a and the yarn 310 ', and 320' are melted so that the ultra-small LED elements 310b and 320b may be arranged on the first electrode and / or the second electrode as shown in FIG. 14B.

Subsequently, when power is applied to the first electrode 301 and the second electrode 302 as shown in FIG. 14C, the ultra-small LED elements 310b and 320b are connected to the two small electrodes 301 and 302, An electrode assembly including the device can be manufactured.

Next, the nonwoven fabric may be a known nonwoven fabric and is not particularly limited in the present invention. Non-limiting examples of this include wicks, spunbond, felt, needle punching, padding, Tyvek, Chamude, and the like.

If the nonwoven fabric has the shape, the amount of the conjugated fibers contained per unit volume can be included more than the fabric, and the number of the ultra-small LED elements that can be disposed on the electrode of a certain area can be significantly increased have. Such a nonwoven fabric may be produced by using a conjugate fiber according to a method known in the art. Specifically, a melt-blown method, a flash-extrusion method, a super- drawing) method, and the specific process of the method can be performed by those known in the art.

Claims (15)

A fiber forming component comprising at least one of a thermoplastic polymer compound removed by heat and a polymer compound removed by a solvent; And
And a plurality of ultra-small LED elements included in the fiber forming component and having a single element length of 100 nm to 10 탆. The method according to claim 1,
Wherein the plurality of ultra-small LED elements are arranged in at least one row in the longitudinal direction of the composite fibers. The composite fiber according to claim 2,
A core portion formed by rowing a plurality of ultra-small LED elements in a row; And
And a fiber-forming component surrounding the core to form a composite fiber. The method of claim 3,
Wherein the diameter of the composite fiber is 1.2 to 8.0 times the minor axis length of the ultra-small LED device. 3. The method of claim 2,
Wherein the plurality of ultra-small LED elements are arranged in a plurality of rows in the longitudinal direction of the composite fibers. The method according to claim 1,
Wherein the fiber forming component is removed at the time of manufacturing the ultra miniature LED electrode assembly. The method according to claim 1,
The polymer compound to be removed by the solvent includes at least one polymer compound selected from the group consisting of poly (methyl methacrylate) (PMMA), polystyrene (PS), PVC and PVA. . The method according to claim 1,
Wherein the composite fiber comprises the ultrafine LED element in an amount of 30 to 90 parts by weight based on 100 parts by weight of the fiber forming component. The method according to claim 1,
Wherein the ultra miniature LED element is in the form of a rod. The LED according to claim 1, wherein the ultra-small LED element
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, wherein the second conductive semiconductor layer is formed on the active layer. 11. The method of claim 10,
The ultra miniature LED device includes a first electrode layer formed under the first conductive semiconductor layer; And a second electrode layer formed on the first conductive semiconductor layer and the second conductive semiconductor layer. 11. The method of claim 10,
Wherein the outer surface of the ultra-small LED element is coated with an insulating coating covering at least an entire outer surface of the active layer portion. 13. The method of claim 12,
Wherein the outer surface of the insulating coating is coated with a hydrophobic coating. delete 14. Fabric comprising the composite fiber according to any one of claims 1 to 13 as at least one of warp or weft.

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