Method for self-arranging and transferring micro devices by using brushing

Abstract

The disclosed method for arranging micro devices comprises the steps of: preparing an array substrate including, in a plan view, a plurality of first regions having hydrophilic surfaces, and a second region surrounding the first regions and having a hydrophobic surface; dropping a plurality of micro devices dispersed in a liquid onto the array substrate; and brushing the array substrate to arrange, on the first regions, the micro devices aligned in the vertical direction and the horizontal direction. According to the method for arranging, the efficiency of an alignment process and an assembly process for micro light-emitting devices may be significantly increased by aligning the vertical direction and the horizontal direction of flip chip light-emitting diodes through a simple process.

Description

Self-arrangement method and transfer method of micro-elements using brushing

[0001] The present invention relates to a method for arranging micro-elements, and more specifically, to a method for self-arranging micro-elements using brushing and a transfer method.

[0002] Recently, micro-sized light-emitting diodes (LEDs) have been used in lighting and display devices. Pick-and-place methods are used to transfer these micro-LEDs onto a substrate. However, as the size of these micro-LEDs decreases and the size of display and lighting devices increases, this transfer method is becoming a constraint on productivity.

[0003] Accordingly, alignment methods using electric fields, alignment methods using magnetic fields, and alignment methods using self-assembly are being studied to transfer micro-luminescent elements or align them before the transfer process.

[0004] However, methods utilizing electric fields struggle with precise position control, and transfer efficiency for certain devices or materials can be low. Furthermore, methods utilizing magnetic fields face limitations in terms of the distance at which the magnetic field can be applied, making it difficult to maintain precision and efficiency. Furthermore, self-assembly methods require light-emitting devices with specific structures or complex control methods.

[0005] The technical problem of the present invention is conceived from this point of view, and is to provide a self-arrangement method that can easily align micro devices such as light-emitting devices.

[0006] Another object of the present invention is to provide a method for transferring a micro device using the self-arrangement method.

[0007] However, the problem to be solved by the present invention is not limited to the problem mentioned above, and may be expanded in various ways without departing from the spirit and scope of the present invention.

[0008] According to one embodiment of the present invention, a method for arranging micro-elements includes the steps of preparing an array substrate including a plurality of first regions having hydrophilic surfaces on a plan view and a second region surrounding the first regions and having a hydrophobic surface, a step of dropping a plurality of micro-elements dispersed in a liquid onto the array substrate, and a step of arranging the micro-elements aligned in a vertical direction and a horizontal direction on the first regions by brushing on the array substrate.

[0009] According to one embodiment, the array substrate includes a base substrate having a hydrophilic surface and a bank disposed on the base substrate and having openings corresponding to the first regions.

[0010] According to one embodiment, the step of preparing the array substrate includes the step of forming a photosensitive layer by coating a photoresist composition on a base substrate, the step of partially exposing the photosensitive layer, and the step of developing the photosensitive layer to form a bank having openings.

[0011] In one embodiment, the micro device comprises a micro light emitting diode having a P electrode and an N electrode arranged on the same surface.

[0012] In one embodiment, the liquid comprises a hydrophilic solvent.

[0013] In one embodiment, the liquid comprises alcohol.

[0014] According to one embodiment, the first region has a rectangular shape, and the brushing is performed in a direction parallel to the long side of the rectangle.

[0015] According to one embodiment, the flexural rigidity of the fibers of the brush is 0.1 mN-mm 2 / tex 2 Below, the aspect ratio is 500 to 2,000.

[0016] In one embodiment, the brush comprises artificial hair.

[0017] According to one embodiment, the ends of the fibers of the brush have a flat shape.

[0018] According to one embodiment, the array substrate includes an electrode array disposed on the first regions.

[0019] In one embodiment, the microdevice has a flip-chip form and has an asymmetrical structure in cross-section.

[0020] In one embodiment, the micro-device includes at least a substrate and an external electrode, and has a first side defined by an exposed surface of the substrate, and a second side opposite the first side and on which the external electrode is exposed, and after alignment by brushing, the first side of the micro-device faces the base substrate.

[0021] According to one embodiment of the present invention, a method for transferring a micro device includes the steps of preparing an array substrate including a plurality of first regions having hydrophilic surfaces on a plan view and a second region surrounding the first regions and having a hydrophobic surface, dropping a plurality of micro devices dispersed in a liquid onto the array substrate, arranging the micro devices aligned in a vertical direction and a horizontal direction on the first regions by brushing on the array substrate, transferring the micro devices aligned on the first regions onto a carrier substrate, and transferring the micro devices on the carrier substrate to a transfer substrate including an electrode array.

[0022] According to embodiments of the present invention, by manufacturing a micro device of a specific shape or aligning the vertical and horizontal directions of a flip-chip light-emitting diode with a simple process without complex process control, the efficiency of the alignment process and assembly process of the micro light-emitting device can be significantly increased.

[0023] FIG. 1 is a schematic diagram illustrating a self-arrangement method of micro devices according to one embodiment of the present invention.

[0024] FIG. 2 is a schematic diagram illustrating a rotation direction for alignment of a micro device according to one embodiment of the present invention.

[0025] FIG. 3 is a plan view illustrating an alignment substrate used in a self-arrangement method of a micro device according to one embodiment of the present invention.

[0026] Figure 4 is a cross-sectional view taken along line I-I' of Figure 2.

[0027] FIG. 5 illustrates a cross-section of a micro light-emitting diode that can be used in a self-arrangement method of micro devices according to one embodiment of the present invention.

[0028] FIG. 6 is a schematic diagram illustrating an alignment step through brushing in a self-arrangement method of a micro device according to one embodiment of the present invention.

[0029] FIG. 7 is a plan view illustrating an alignment step through brushing in a self-arrangement method of a micro device according to one embodiment of the present invention.

[0030] FIG. 8 is a side view illustrating an alignment step through brushing in a self-arrangement method of a micro device according to one embodiment of the present invention.

[0031] FIG. 9 is a cross-sectional view illustrating a method for transferring a micro device according to one embodiment of the present invention.

[0032] Figure 10 is a flowchart schematically illustrating a process for manufacturing an array substrate.

[0033] FIG. 11a is a photograph of micro light emitting diodes aligned on an array substrate after the brushing step of Example 1.

[0034] Figure 11b is a photograph of micro light emitting diodes aligned on an array substrate after the brushing step of Comparative Example 1.

[0035] Figure 12 is a photograph showing the brushes used in the experiment of the present invention.

[0036] Hereinafter, with reference to the attached drawings, a self-arrangement method and a transfer method of micro devices according to embodiments of the present invention will be described in detail. The present invention can be modified in various ways and can take various forms, and thus specific embodiments will be illustrated and described in detail in the text. However, this is not intended to limit the present invention to a specific disclosed form, but should be understood to include all modifications, equivalents, and substitutes included in the spirit and technical scope of the present invention. In the attached drawings, the dimensions of structures are illustrated larger than actual dimensions to ensure clarity of the present invention.

[0037] The terminology used in this application is only used to describe specific embodiments and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, it should be understood that the terms "comprise" or "have" indicate the presence of a feature, number, step, operation, component, or combination thereof described in the specification, but do not preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, or combinations thereof.

[0038] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and shall not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0039] Fig. 1 is a schematic diagram illustrating a self-alignment method of micro devices according to one embodiment of the present invention. Fig. 2 is a schematic diagram illustrating a rotation direction for aligning micro devices according to one embodiment of the present invention. Fig. 3 is a plan view illustrating an alignment substrate used in a self-alignment method of micro devices according to one embodiment of the present invention. Fig. 4 is a cross-sectional view taken along line II' of Fig. 2.

[0040] Referring to FIG. 1, first, a dispersion liquid having microelements dispersed therein is provided on a substrate having a plurality of first regions and second regions surrounding the first regions. The microelements provided on the substrate are brushed in one direction. As a result of the brushing, the microelements are arranged on the first regions. The solvent (dispersing medium) of the dispersion liquid is removed to form an aligned microelement array. Hereinafter, the substrate may be referred to as an aligned substrate.

[0041] As illustrated in FIG. 2, when the micro device is a micro light-emitting diode having a flip-chip structure, it needs to be connected to the electrode array of the substrate during the alignment process or through transfer after alignment. Accordingly, the micro device needs to be aligned in three aspects. Specifically, the horizontal positions (XY positions) of the micro devices need to be aligned, the upper or lower surfaces of the micro devices need to be vertically aligned so that they face a certain direction, and the horizontal direction (the order of the P electrode and the N electrode) of the micro devices needs to be aligned in a certain direction. Hereinafter, a specific configuration capable of achieving the above three alignments will be described.

[0042] Referring to FIG. 3, the alignment substrate (100) includes a first region (110) and a second region (120). For example, the first regions (110) may be arranged in a matrix form within the second region (120) on a plan view.

[0043] The first region (110) may have a shape extending in one direction. For example, the first region (110) may have a rectangular shape having a long side (S1) parallel to the first direction (D1) and a short side (S2) parallel to a second direction (D2) intersecting the first direction (D1). However, embodiments of the present invention are not limited thereto, and the first region (110) may have another polygonal shape, such as a square.

[0044] According to one embodiment, the first region (110) may have hydrophilicity, and the second region (120) may have hydrophobicity. However, embodiments of the present invention are not limited thereto, and considering the properties of the solvent (dispersion medium) in which the micro device is dispersed, the first region (110) may be formed to have hydrophobicity, and the second region (120) may be formed to have hydrophilicity.

[0045] Referring to FIG. 4, the first region (110) can form a well structure by having a lower height than the second region (120) surrounding the first region (110).

[0046] According to one embodiment, a bank (104) having an opening corresponding to the first region (110) can be formed on a base substrate (102), and the surface of the base substrate (102) has hydrophobicity, and by having the surface of the bank (104), a first region (110) and a second region (120) having different characteristics can be defined.

[0047] According to one embodiment, the array substrate (100) can be manufactured through a photolithography process.

[0048] For example, a photosensitive layer is formed by applying a photoresist composition on a silicon substrate. In the photosensitive layer, a portion corresponding to the first region (110) is masked (shielded), and a portion corresponding to the second region (120) is exposed to light, and then the unexposed portion is removed through development. Accordingly, in the first region (110), the upper surface of the silicon substrate is exposed to form a hydrophilic region, and in the second region covered with the photoresist, a hydrophobic region may be formed. However, embodiments of the present invention are not limited thereto, and a structure having a hydrophilic well may be formed by various known methods. For example, a glass substrate may be used instead of a silicon substrate. In addition, after forming a pattern, the surface of the first region or the second region may be modified to have desired characteristics through hydrophilic treatment or hydrophobic treatment.

[0049] In one embodiment, the micro device may be a micro light-emitting diode (LED). Specifically, the micro light-emitting diode may have a flip-chip configuration in which two external electrodes are arranged on one surface. Fig. 5 illustrates a cross-section of a micro light-emitting diode that can be used in a self-arrangement method of a micro device according to one embodiment of the present invention.

[0050] Referring to FIG. 5, a micro light emitting diode (200) may include a substrate (210), a first semiconductor layer (220), an active layer (230), a second semiconductor layer (240), an internal electrode (250), a Bragg reflective layer (260), and an external electrode. The external electrode includes a first external electrode (270) electrically connected to the first semiconductor layer (220) and a second external electrode (280) electrically connected to the second semiconductor layer (240). The first external electrode (270) and the second external electrode (280) may be disposed on the same surface.

[0051] For example, the substrate (210) may be a sapphire substrate. The first semiconductor layer (220) may include n-GaN, and the second semiconductor layer (240) may include p-GaN. The active layer (230) may have a multiple quantum well (MQW) or single quantum well (SQW) structure. The internal electrode (250) may include a conductive oxide such as ITO.

[0052] The above micro light emitting diode may have a rectangular shape in a plan view. However, embodiments of the present invention are not limited thereto, and the micro light emitting diode may have other polygonal shapes, such as a square shape.

[0053] The structure of the micro light-emitting diode illustrated in FIG. 5 is exemplary, and embodiments of the present invention are not limited thereto, and various other known flip-chip type bike light-emitting diodes can be used in the present invention.

[0054] Fig. 6 is a schematic diagram illustrating an alignment step through brushing in a self-arrangement method for micro devices according to one embodiment of the present invention. Fig. 7 is a plan view illustrating an alignment step through brushing in a self-arrangement method for micro devices according to one embodiment of the present invention. Fig. 8 is a side view illustrating an alignment step through brushing in a self-arrangement method for micro devices according to one embodiment of the present invention.

[0055] Referring to FIGS. 6 to 8, micro-elements provided on an alignment substrate are brushed. The brushing is performed in one direction. In one embodiment, the brushing may be performed in a direction parallel to the long side of the first region.

[0056] Since the micro device (200) has a flip-chip form, it has an asymmetrical structure in cross-section. Accordingly, the center of gravity (WS) of the micro device may have an eccentric structure so as to be closer to one of the two opposite sides, that is, closer to the P electrode (280) or the N electrode (270). In this case, the area adjacent to the center of gravity (WS) may be heavier than the remaining area, and thus may have greater frictional force. When a horizontal external force is applied to the side surface of the micro device through contact with the fiber (300) of the brush, the micro device (200) may rotate based on the center of gravity (WS). When the micro device (200) rotates, the direction in which the horizontal force is applied becomes perpendicular to the first side (L1) that is closer to the center of gravity (WS), and when the horizontal force is applied to the first side (L1), it is difficult to generate a rotational torque, and therefore the micro device (200) may not substantially rotate. Accordingly, the micro elements can be aligned in a certain direction.

[0057] In addition, since the micro elements (200) are dispersed in a hydrophilic liquid, when they are moved by the horizontal force and placed on the first region (110), they can be easily captured within the well structure of the first region (110).

[0058] According to one embodiment, the thickness (height) of the micro device (200) is greater than the depth of the well structure.

[0059] The first surface defined by the substrate (210) of the micro device (200) and the second surface mainly defined by the external electrodes (270, 280) of the micro device (200) may have different affinities (water contact angles) for the hydrophilic surface. For example, when the substrate (210) of the micro device (200) includes sapphire and the external electrodes (270, 280) of the micro device (200) include a metal such as gold (Au), the first surface corresponding to the substrate of the micro device (200) may have a greater affinity for the upper surface of the silicon substrate defining the hydrophilic surface. In addition, since the micro device (200) is dispersed in a liquid and is in a fluid state, it is easy to be flipped upside down. Therefore, there is a high possibility that the first surface of the micro device (200) will come into contact with the hydrophilic surface.

[0060] When the first surface of the micro device (200) comes into contact with the hydrophilic surface of the first region (110), the first surface of the micro device (200) and the hydrophilic surface of the first region (110) can be relatively strongly bonded. Therefore, even if a horizontal force is applied by brushing, the position of the micro device (200) can be maintained within the well structure.

[0061] When the second surface of the micro device (200) comes into contact with the hydrophilic surface of the first region (110), the second surface of the micro device (200) and the hydrophilic surface of the first region (110) may be relatively weakly bonded. Therefore, when a horizontal force is applied by brushing, the micro device (200) may come out of the well structure by a counter force or rotational torque. The micro device (200) that has moved out of the well structure may repeat the step of being horizontally aligned by brushing again and captured in the well structure, and when the first surface of the micro device (200) comes into contact with the hydrophilic surface of the first region (110), the micro device (200) may be stably fixed in the well structure.

[0062] In order for the first region (110) to capture the micro device (200) in a 1:1 ratio and to align the horizontal position of the micro device (200), the first region (110) and the micro device (200) may be designed to have an appropriate ratio and shape. For example, when the micro device (200) and the first region (110) have a rectangular shape having a long side and a short side, the ratio of the long side of the first region (110) to the long side of the micro device (200) may be 1.1 to 1.5, and the ratio of the short side of the first region (110) to the short side of the micro device (200) may be 1.1 to 1.8.

[0063] In addition, for efficient vertical alignment of the micro device (200), the ratio of the height of the micro device (200) to the depth of the well structure may be 1.1 to 1.3. If the height of the micro device (200) is too small, the vertical alignment process may not be performed, and if it is too large, the efficiency of the alignment process may be reduced as the micro device (200) aligned within the well structure may fall out of the well structure.

[0064] In addition, in order to perform the alignment step of the present invention, the fibers of the brush need to have appropriate physical properties. For example, it may be desirable for the brush to be soft. For example, the flexural rigidity of the fibers of the brush may be 0.1 mN-mm. 2 / tex 2 may be less than, and in one embodiment, 0.05 mN-mm 2 / tex 2 0.85 mN-mm 2 / tex 2 It may be less than (tex = g / km). In addition, the aspect ratio of the fibers of the brush may be 500 to 2,000. If the bending rigidity of the brush is too low or the aspect ratio is too large, the efficiency of horizontal alignment may be reduced. In addition, if the bending rigidity of the brush is too high or the aspect ratio is too small, the micro-elements installed within the well structure may be detached again, or scratches may occur on the pattern surface.

[0065] Additionally, it may be desirable for the brush to have a flat (close to a straight line) shape at the end of the connecting line rather than an arc or parabola.

[0066] In one embodiment, synthetic hair may be used as the fiber of the brush. The synthetic hair may be formed of polyamide, polyester, modacryl, polyvinyl chloride, or the like. In one embodiment, the fiber of the brush may be polyester fiber.

[0067] The dispersion may include various types of liquids that do not corrode or damage the micro light-emitting element. For example, the liquid may include water, ethanol, isopropyl alcohol, ketone, acetone, etc. If the first region (110) is hydrophilic, the liquid may include a hydrophilic solvent such as water, ethanol, isopropyl alcohol, etc.

[0068] In one embodiment, to increase the efficiency of the alignment process, the dispersion may contain alcohol. When the dispersion contains alcohol, the dispersion rapidly evaporates before the drying process, thereby increasing the adhesive force at the contact surface between the micro device (200) and the first region (110), thereby allowing the micro device (200) to be stably placed on the first region (110).

[0069] A drying process may be performed to remove the solvent from the above dispersion. Various known methods, such as heating, hot air drying, and natural drying, may be used for the drying process.

[0070] FIG. 9 is a cross-sectional view illustrating a method for transferring a micro device according to one embodiment of the present invention.

[0071] Referring to Fig. 9, micro-elements aligned on an array substrate (100) according to the arrangement method described above are transferred to a first carrier substrate (410). Next, the micro-elements are transferred to a second carrier substrate (420) to expose external electrodes. Next, the micro-elements are transferred from the second carrier substrate (420) to a transfer substrate (430) having an electrode array (432).

[0072] The above micro-elements are aligned in the same horizontal and vertical directions with external electrodes through horizontal and vertical alignment. Therefore, they can be transferred in large quantities onto a transfer substrate (430) having an electrode array (432). Therefore, the efficiency of the transfer process of the micro-elements can be significantly improved.

[0073] In the above embodiment, the micro-elements are aligned on the array substrate and then transferred to the transfer substrate again using the carrier substrate. However, the embodiments of the present invention are not limited thereto. For example, according to one embodiment, the array substrate may be used as a carrier substrate to directly transfer to the transfer substrate. In addition, the array substrate includes an electrode array arranged on the bottom of the well structure, and by adjusting the physical properties so that the electrode surface of the micro-element faces the electrode array, the micro-element may be directly assembled to the array substrate on which the wiring and electrodes are formed.

[0074] According to embodiments of the present invention, the efficiency of the alignment and assembly processes of micro light-emitting devices can be significantly increased by fabricating micro devices of a specific shape or aligning the vertical and horizontal directions of flip-chip light-emitting diodes through a simple process without complex process control.

[0075] Below, the performance and effects of embodiments of the present invention will be examined through specific experimental examples.

[0076] Fabrication of array substrates

[0077] Fig. 10 is a flowchart schematically illustrating a process for manufacturing an array substrate. As illustrated in Fig. 10, after cleaning a silicon wafer substrate, a negative photoresist composition, SU-8, was coated to a thickness of 60 μm, and then prebaked for 30 minutes. After UV exposure was performed using a mask in which 50 x 50 light-shielding areas of 260 μm x 170 μm were arranged, post-baking was performed for 5 minutes. Next, a photosensitive layer that was not exposed was removed using a developer, thereby preparing an array substrate having a patterned layer with an opening on the silicon substrate.

[0078] Example 1

[0079] On the above array substrate, a dispersion solution (containing 1:1 water and isopropyl alcohol as solvent) containing 2,500 micro light-emitting diodes (Photonstar) of 200㎛ x 100㎛ x 80㎛ (length x width x height) was dropped, and brushing was performed (2-3 times per second for about 1 minute) in the long side direction of the opening of the array substrate using a foundation brush (Picasso) with a fiber diameter of about 10㎛ and a length of about 10mm.

[0080] Comparative Example 1

[0081] Instead of the brush of Example 1, brushing was performed using a relatively hard powder brush (cosmaple).

[0082] FIG. 11a is a photograph of micro light emitting diodes aligned on an array substrate after the brushing step of Example 1, and FIG. 11b is a photograph of micro light emitting diodes aligned on an array substrate after the brushing step of Comparative Example 1.

[0083] Referring to FIGS. 11a and 11b, in the case of Example 1 using a soft brush, it was confirmed that micro light-emitting diodes were arranged in all wells (7 x 5), and were 100% aligned in the vertical direction (with the external electrodes facing upward) and more than 80% aligned in the horizontal direction (29 / 35). On the other hand, in the case of Comparative Example 1 using a hard brush, the probability that micro light-emitting diodes were arranged in the wells was approximately 50%, and it was confirmed that scratches occurred in the pattern.

[0084] Through this, it was confirmed that the characteristics of the brush have a great influence on the effectiveness of the alignment process of the present invention.

[0085] Figure 12 is a photograph illustrating brushes used in the experiments of the present invention. As a result of the experiment, it was confirmed that brushes (eye shadow, smudge, brow, and above Cosmaple, Example 1) with flat ends (the lines connecting the fiber ends are close to straight lines) can stably align micro-elements more than brushes (powder, contour, blusher, foundation, fan, blending, concealer, and above Cosmaple) with non-flat ends (the lines connecting the fiber ends form an arc or parabola).

[0086] Although the present invention has been described above with reference to embodiments, it will be understood by those skilled in the art that various modifications and changes can be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below.

[0087] The present invention can be used in the manufacture of various electronic devices and lighting devices using micro elements, and specifically, can be used in the manufacture of backlights, micro light-emitting diode displays, etc.

[0088] <Explanation of symbols>

[0089] 100: Array substrate

[0090] 110: Area 1

[0091] 120: Area 2

[0092] 102: Base board

[0093] 104: Bank

[0094] 200: Micro light-emitting diode

[0095] 270, 280: External electrode

[0096] 300: Brush

[0097] 410, 420: Carrier substrate

[0098] 430: Warrior board

Claims

1. A step of preparing an array substrate including a plurality of first regions having hydrophilic surfaces on a plan view and a second region surrounding the first regions and having a hydrophobic surface; A step of dropping a plurality of micro elements dispersed in a liquid onto the array substrate; and A method for arranging micro-elements, comprising the step of arranging the micro-elements aligned in the vertical and horizontal directions on the first regions by brushing on the array substrate.

2. In the first paragraph, the array substrate, a base substrate having a hydrophilic surface; and A method for arranging micro-elements, comprising a bank disposed on the base substrate and having openings corresponding to the first regions.

3. In the first paragraph, the step of preparing the array substrate comprises: A step of forming a photosensitive layer by coating a photoresist composition on a base substrate; a step of partially exposing the photosensitive layer; and A method for arranging micro-elements, comprising the step of developing the photosensitive layer to form a bank having openings.

4. A method for arranging micro-elements in the first paragraph, wherein the micro-element includes a micro-light emitting diode having a P electrode and an N electrode arranged on the same surface.

5. A method for arranging micro-elements in the first paragraph, wherein the liquid comprises a hydrophilic solvent.

6. A method for arranging micro devices in the first paragraph, wherein the liquid contains alcohol.

7. A method for arranging micro-elements in the first paragraph, wherein the first region has a rectangular shape, and the brushing is performed in a direction parallel to the long side of the rectangle.

8. In the first paragraph, the flexural rigidity of the fiber of the brush is 0.1 mN-mm 2 / tex 2 A method for arranging micro-elements, wherein the micro-elements have an aspect ratio of 500 to 2,000.

9. A method for arranging micro-elements in claim 8, wherein the brush includes artificial hair.

10. A method for arranging micro-elements in claim 8, wherein the ends of the fibers of the brush have a flat shape.

11. In paragraph 1, A method for arranging micro devices, wherein the array substrate includes an electrode array arranged on the first regions.

12. A method for arranging micro-elements in the first paragraph, wherein the micro-element has a flip-chip shape and has an asymmetrical structure in cross-section.

13. A method for arranging micro-elements in the first paragraph, wherein the micro-element includes at least a substrate and an external electrode, and has a first side defined by an exposed surface of the substrate, and a second side opposite to the first side and on which the external electrode is exposed, and after being aligned by brushing, the first side of the micro-element faces the base substrate.

14. A step of preparing an array substrate including a plurality of first regions having hydrophilic surfaces on a plan view and a second region surrounding the first regions and having a hydrophobic surface; A step of dropping a plurality of micro elements dispersed in a liquid onto the array substrate; A step of arranging the micro elements aligned in the vertical and horizontal directions on the first regions by brushing on the array substrate; A step of transferring the micro elements aligned on the first regions onto a carrier substrate; and A method for transferring micro-elements, comprising the step of transferring the micro-elements on the carrier substrate to a transfer substrate including an electrode array.

15. A method for transferring a micro device in claim 14, wherein the liquid contains alcohol.

16. An electronic method of a micro device in claim 14, wherein the first region has a rectangular shape, and the brushing is performed in a direction parallel to the long side of the rectangle.

17. In the 14th paragraph, the flexural rigidity of the fiber of the brush is 0.1 mN-mm 2 / tex 2 A method for transferring a micro device having an aspect ratio of 500 to 2,000.

18. A method for transferring a micro device in claim 14, wherein the first region has a rectangular shape, and the brushing is performed in a direction parallel to the long side of the rectangle.

19. A method for transferring a micro device in claim 14, wherein the micro device has a flip-chip shape and has an asymmetrical structure in cross-section.

20. A method for transferring a micro-device in claim 14, wherein the micro-device includes at least a substrate and an external electrode, and has a first side defined by an exposed surface of the substrate, and a second side opposite to the first side and on which the external electrode is exposed, and after being aligned by brushing, the first side of the micro-device faces the base substrate.

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