Micro LED transfer system and micro LED transfer method using same

Abstract

A micro LED transfer system according to an embodiment of the present disclosure may include a first transfer device for transferring a micro LED to a second substrate, and / or a second transfer device for transferring a micro LED to a second substrate. The first transfer apparatus may include: a first laser light source unit for irradiating a first substrate on which a micro LED is disposed with a laser beam; a mask unit disposed between the first substrate and the first laser light source unit and selectively opening and closing the at least one opening; and a first processor for controlling the mask unit such that the opening corresponding to the micro LED transferred to the second substrate is opened and closed. The first transfer device and / or the second transfer device may transfer the micro LEDs to a second substrate having an irregular shape.

Description

Technical Field

[0001] The embodiments of this disclosure relate to a micro light-emitting diode (LED) transfer system and a micro LED transfer method using the micro LED transfer system, which transfers multiple micro LEDs formed on a wafer to a printed circuit board of a display panel. Background Technology

[0002] A micro LED is an ultra-small inorganic light-emitting material that emits light itself without the need for color filters or backlighting. Specifically, a micro LED has one-tenth the length and one-hundredth the area of ​​a conventional light-emitting diode (LED) chip, and can refer to an ultra-small LED with a width, length, and height ranging from 10 μm to 100 μm.

[0003] Micro-LEDs are manufactured as chips on a wafer and mounted on a target substrate to form the light-emitting module of a display. The process of mounting micro-LEDs on the target substrate is the process of effectively transferring micro-LEDs into the space of the substrate and electrically or physically connecting the micro-LEDs to the substrate, and it is the core process in manufacturing micro-LED display modules.

[0004] Meanwhile, with the recent emergence of various types of display devices such as wearable devices, there is a need for technologies that can effectively transfer micro-LEDs onto various types of target substrates. Summary of the Invention

[0005] Solution to the problem

[0006] Various embodiments of this disclosure may provide a microLED transfer system and a microLED transfer method using the microLED transfer system, wherein the microLED transfer system effectively transfers microLEDs onto a target substrate having an irregular shape using at least one of a first transfer device and a second transfer device.

[0007] The microLED transfer system according to embodiments of the present disclosure may include at least one of a first transfer device for transferring microLEDs to a second substrate and a second transfer device for transferring microLEDs to the second substrate. The first transfer device may include: a first laser source unit for irradiating a laser beam onto the first substrate on which the microLEDs are disposed; a mask unit disposed between the first substrate and the first laser source unit, and selectively opening and closing at least one opening; and a first processor for controlling the mask unit to open and close the opening corresponding to the microLED transferred to the second substrate. At least one of the first or second transfer devices can transfer microLEDs to a second substrate having an irregular shape.

[0008] According to an embodiment, the mask unit may include a curved portion with a predetermined curvature. The first processor can form an irregularly shaped laser beam by moving and rotating the mask unit.

[0009] According to an embodiment, the mask unit may have a quadrant shape including curved portions. The first processor can form a circular laser beam by moving and rotating the mask unit.

[0010] According to an embodiment, the mask unit may include a first mask for shaping the laser beam and a second mask for scanning the laser beam onto a first substrate.

[0011] According to an embodiment, the first mask may include a shaping opening having at least one shape among rectangle, triangle, circle, semicircle and sector.

[0012] According to an embodiment, the first processor can form an irregularly shaped laser beam by moving and rotating a first mask.

[0013] According to an embodiment, the first transfer device can transfer the microLED to the second substrate in a multiple-transfer manner. The second transfer device can transfer the microLED to the second substrate one at a time.

[0014] According to an embodiment, the second transfer device may include: a second laser source unit that outputs a laser beam; a path changing unit that changes the path of the laser beam; and a second processor that controls the path changing unit to change the path of the laser beam toward the micro-LED being transferred to the second substrate.

[0015] According to an embodiment, a first transfer device can transfer a microLED to a first region of a second substrate. A second transfer device can transfer a microLED to a second region of the second substrate.

[0016] According to an embodiment, the first region may include a non-bent region of the second substrate. The second region may include a bent region of the second substrate.

[0017] The microLED transfer method according to embodiments of the present disclosure may include: transferring a microLED to a second substrate using a first transfer device; and transferring a microLED to the second substrate using a second transfer device. Transferring a microLED to the second substrate using the first transfer device may include: irradiating the first substrate on which the microLED is disposed using a first laser light source unit; selectively opening or closing at least one opening using a mask unit disposed between the first substrate and the first laser light source unit; and controlling the mask unit to open and close the opening corresponding to the microLED transferred to the second substrate using a first processor. At least one of the first transfer device or the second transfer device can transfer a microLED to a second substrate having an irregular shape.

[0018] According to an embodiment, the mask unit may include a curved portion with a predetermined curvature. Using a first processor to control the mask unit, an irregularly shaped laser beam can be formed by moving and rotating the mask unit.

[0019] According to an embodiment, the mask unit may have a quadrant shape including curved portions. Using a first processor to control the mask unit, a circular laser beam can be formed by moving and rotating the mask unit.

[0020] According to an embodiment, selectively opening and closing at least one opening using a mask unit may include: shaping a laser beam using a first mask; and scanning the laser beam onto a first substrate using a second mask.

[0021] According to an embodiment, the first mask may include a shaping opening having at least one shape among rectangle, triangle, circle, semicircle and sector.

[0022] According to an embodiment, the mask unit controlled by the first processor can form an irregularly shaped laser beam by moving and rotating the first mask.

[0023] According to an embodiment, the first transfer device can transfer the microLED to the second substrate in a multiple-transfer manner. The second transfer device can transfer the microLED to the second substrate one at a time.

[0024] According to an embodiment, transferring a micro-LED to a second substrate using a second transfer device may include: outputting a laser beam using a second laser source unit; changing the path of the laser beam using a path changing unit; and using a second processor to control the path changing unit to change the path of the laser beam toward the micro-LED transferred to the second substrate.

[0025] According to an embodiment, using a first transfer device to transfer a microLED to a second substrate can transfer the microLED to a first region of the second substrate. Using a second transfer device to transfer the microLED to a second region of the second substrate can transfer the microLED to a second region of the second substrate.

[0026] According to an embodiment, the first region may include a non-bent region of the second substrate. The second region may include a bent region of the second substrate.

[0027] According to various embodiments of the present disclosure, the microLED transfer system and the microLED transfer method using the present disclosure can transfer microLEDs onto a target substrate with an irregular shape by moving and rotating a mask unit including a curved portion.

[0028] Furthermore, the microLED transfer system and the microLED transfer method using the microLED transfer system disclosed herein can transfer microLEDs onto a target substrate with an irregular shape by using a first mask to shape the laser beam and using a second mask to scan the laser beam onto the wafer.

[0029] Furthermore, the microLED transfer system and the microLED transfer method using the microLED transfer system disclosed herein can transfer microLEDs to a target substrate with an irregular shape by transferring microLEDs to the non-bent portion of the target substrate in a multiple transfer manner using a first transfer device, and transferring microLEDs to the bent portion of the target substrate in a sequential transfer manner using a second transfer device.

[0030] Therefore, the microLED transfer system and the microLED transfer method using the present disclosure can effectively transfer microLEDs to target substrates with irregular shapes suitable for display devices with various shapes.

[0031] The effects obtainable according to the exemplary embodiments of this disclosure are not limited to those described above, and other effects not mentioned can be clearly deduced and understood by those skilled in the art to which the exemplary embodiments of this disclosure pertain based on the following description. In other words, those skilled in the art can also deduce unexpected effects when practicing the embodiments of this disclosure based on the exemplary embodiments of this disclosure. Attached Figure Description

[0032] Figure 1 A first transfer device of a micro LED transfer system according to an embodiment is shown.

[0033] Figure 2 A partial block configuration of the first transfer device according to an embodiment is shown.

[0034] Figure 3 A mask unit of a first transfer device according to an embodiment is shown.

[0035] Figure 4 A first substrate used in a first transfer apparatus according to an embodiment is shown.

[0036] Figure 5 The diagram shows... Figure 4 An enlarged view of the first region of the first substrate.

[0037] Figure 6 The diagram shows... Figure 5 Enlarged views of parts A and B of the first region.

[0038] Figure 7A second substrate used in a first transfer apparatus according to an embodiment is shown.

[0039] Figure 8 The micro-LED transfer operation sequence of the first transfer device according to an embodiment is shown.

[0040] Figure 9 A mask unit including a curved portion is shown according to an embodiment.

[0041] Figure 10 A mask unit that moves and rotates under the control of a processor, according to an embodiment, is shown.

[0042] Figure 11 The micro-LED transfer operation sequence of the first transfer device according to an embodiment is shown.

[0043] Figure 12 The laser beam is shown passing through the first and second masks in sequence.

[0044] Figure 13 The micro-LED transfer operation sequence of the first transfer device and the second transfer device according to the embodiment is shown.

[0045] Figure 14 The first and second regions of the second substrate are shown.

[0046] Figure 15 A second transfer device of a micro LED transfer system according to an embodiment is shown. Detailed Implementation

[0047] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings, enabling those skilled in the art to readily implement the disclosure. However, the present disclosure may be implemented in various other forms and is not limited to the embodiments set forth herein. Throughout the specification and drawings, the same or similar reference numerals may be used to refer to the same or similar elements. Furthermore, for clarity and brevity, well-known functions and configurations are not described in the drawings and related descriptions.

[0048] Figure 1 A miniature LED transfer device according to an embodiment is shown, and Figure 2 A partial block configuration of a micro LED transfer device according to an embodiment is shown.

[0049] refer to Figure 1 and Figure 2According to embodiments of the present disclosure, a first transfer device 1 for transferring micro-LEDs may include a transfer unit 10 that supports a mask unit 50 and is movable above a first substrate 20, a stage 40 on which a second substrate 30 is placed and moved, a mask unit 50 that selectively allows a laser beam irradiated onto the first substrate 20 to pass through, a laser source unit 60 that irradiates the first substrate 20 with the laser beam, and a processor 80 that controls the transfer unit 10, the stage 40, and the mask unit 50 respectively.

[0050] According to an embodiment, the transfer unit 10 may include a fixing member 11 that supports the mask unit 50 to direct the laser beam toward the second substrate 30, and a guide member 12 to which the fixing member 11 is rotatably connected. Figure 1 In the coordinate system shown, the fixed member 11 can be connected to the guide member 12 via the rotation axis 15, thereby allowing it to move along the X-axis via the slider 14. Furthermore, the fixed member 11 can rotate clockwise or counterclockwise about the rotation axis 15 located along the Z-axis. The guide member 12 can be slidably connected to a guide rail (not shown) located in the Y-axis direction to move the fixed member 11 in the Y-axis direction.

[0051] According to an embodiment, the mask unit 50 can be moved to any position on the XY plane by means of the fixing member 11 and the guiding member 12, and can rotate clockwise and / or counterclockwise about the Z-axis. Although the fixing member 11 is in Figure 1 The mask unit 50 is shown as being secured by supporting the edge region of the mask unit 50, but this disclosure is not limited to this, and the mask unit 50 can be securely secured in various ways. For example, the fixing member 11 can be attached to any part of the mask unit 50 by various clamping structures such as vacuum adsorption methods to secure the mask unit 50. For ease of description, Figure 1 The driving devices for rotating the fixed member 11 and for moving the guide member 12 are not shown in the diagram. The guide member 12 is disposed above the second substrate 30 and can move the fixed member 11, which is connected to the mask unit 50, to any position in the XY plane relative to the second substrate 30. Furthermore, the guide member 12 can move the fixed member 11 using various structures such as multi-joint structures, piston structures, and sliding structures.

[0052] According to an embodiment, the first substrate 20 may be a wafer. For example, the first substrate 20 may be a wafer on which a plurality of micro-LEDs 21 grown on various substrates such as a sapphire substrate are disposed. An adhesive layer 22 may be located on one surface of the first substrate 20. The adhesive layer 22 can attach the plurality of micro-LEDs 21 to the first substrate 20. Furthermore, the adhesive layer 22 may be composed of a material melted by a laser beam irradiated onto the first substrate 20, such that the micro-LEDs 21 can be separated from the first substrate 20.

[0053] According to an embodiment, the micro-LED 21 is formed of an inorganic light-emitting material having a width, length, and height of 100 μm or less, and can emit light autonomously when powered. The micro-LED 21 features fast response speed, low power consumption, and high brightness, and is attracting considerable attention as a light-emitting element for next-generation displays. Specifically, compared to liquid crystal displays (LCDs) or organic light-emitting diodes (OLEDs), the micro-LED 21 can be more efficient in converting electrical energy into photons. Therefore, compared to existing LEDs or OLEDs, the micro-LED 21 can achieve the same brightness with only about half the energy. Furthermore, the micro-LED 21 can achieve high resolution, excellent color, contrast, and brightness, and can accurately reproduce a wide color gamut, achieving a clear image even in bright sunlight outdoors. In addition, the micro-LED 21 is less prone to burn-in and generates less heat, thus ensuring a long lifespan without deformation. Furthermore, the micro-LED 21 can include at least one of a red micro-LED emitting red light, a green micro-LED emitting green light, and a blue micro-LED emitting blue light. Micro-LEDs emitting the same color of light can be disposed on a single chip. For example, if the first substrate 20 is a chip, the first substrate 20 may be configured with only red micro-LEDs emitting red light, only green micro-LEDs emitting green light, or only blue micro-LEDs emitting blue light.

[0054] According to an embodiment, the micro-LEDs 21 formed on a wafer may each include an anode electrode and a plurality of cathode electrodes. For example, some micro-LEDs on a wafer may be positioned at 180 degrees (°) relative to the remaining micro-LEDs. Here, "the remaining micro-LEDs positioned at 180 degrees (°)" means that the anode and cathode electrodes of the remaining micro-LEDs are in opposite directions relative to the anode and cathode electrodes of the remaining micro-LEDs. For example, all micro-LEDs on a wafer may be formed such that all anode and cathode electrodes are in the same direction.

[0055] According to an embodiment, the second substrate 30 can be a printed circuit board (PCB) used as a target substrate in a display panel. Unlike the first substrate 20, the second substrate 30 can be manufactured in various sizes and shapes. Furthermore, the second substrate 30 can be a relay substrate of a printed circuit board that receives micro-LEDs from the first substrate 20 and relays the micro-LEDs to the display panel.

[0056] According to an embodiment, the second substrate 30 may be a printed circuit board (PCB) on which a plurality of micro-LEDs 21 transferred from the first substrate 20 are mounted. The second substrate 30 may include a plurality of anode electrode pads and a plurality of cathode electrode pads physically and / or electrically connected to each micro-LED 21. The plurality of anode electrode pads and the plurality of cathode electrode pads of the second substrate 30 may vary corresponding to the arrangement of the anode and cathode electrodes of the plurality of micro-LEDs disposed on the first substrate 20.

[0057] For example, if the remaining micro-LEDs are arranged at 180 degrees (°) relative to some of the micro-LEDs, the plurality of anode electrode pads and the plurality of cathode electrode pads on the second substrate 30 can be arranged in the same direction. Furthermore, if the anode and cathode electrodes of all the micro-LEDs are formed in the same direction, some of the anode electrode pads and cathode electrode pads on the second substrate 30 can be arranged at 0 degrees (°), and the remaining electrode pads can be arranged at 180 degrees (°).

[0058] According to an embodiment, the stage 40 can support the second substrate 30 and the first substrate 20 in parallel arrangement while the second substrate 30 is being loaded or unloaded. When the second substrate 30 is loaded, the stage 40 can move relative to the transfer unit 10. In other words, the stage 40 can move in the XY plane. Furthermore, the stage 40 can also move up and down along the Z-axis. For ease of description, Figure 1 The diagrams of the corresponding drive devices for the XY plane movement and vertical movement of the stage 40 are omitted.

[0059] According to an embodiment, the mask unit 50 is disposed between the laser source unit 60 and the first substrate 20, and allows a laser beam emitted from the laser source unit 60 onto the first substrate 20 to pass through. Reference will be made below. Figure 3 Describe the specific structure of mask unit 50.

[0060] According to an embodiment, the laser light source unit 60 can irradiate the rear surface of the first substrate 20, where no plurality of microLEDs 21 are formed, with a laser beam to peel off the plurality of microLEDs 21. The microLEDs 21 peeled off from the first substrate 20 by the laser beam can be transferred to the second substrate 30.

[0061] According to an embodiment, the laser source unit 60 can directly irradiate a laser beam toward the first substrate 20, or it can include a lens component (e.g., a P-lens) capable of appropriately changing the direction of the laser beam along its irradiation path. The laser source unit 60 can irradiate any one of a point laser beam, a line laser beam, or a surface laser beam. For example, a point laser beam can be a laser beam irradiating a single point. For example, a line laser beam can be a laser beam irradiating along the X-axis or Y-axis at any length. A surface laser beam is a laser beam that simultaneously irradiates any area, and the laser beam can simultaneously or sequentially irradiate multiple [X,Y] coordinate points. In this case, the surface laser beam can be simultaneously or sequentially irradiated relative to any area in multiple parallel diagonal directions.

[0062] According to an embodiment, the laser source unit 60 may be part of a laser beam scanner (not shown), and the laser beam scanner may be included in a micro LED transfer device according to an embodiment of the present disclosure.

[0063] Figure 2 The memory 70 shown can be disposed in the first transfer device 1. The memory 70 can be implemented as at least one of flash memory, read-only memory (ROM), random access memory (RAM), hard disk type, micro multimedia card, and card memory (e.g., SD or XD memory). Furthermore, the memory 70 is electrically connected to the processor 80 and can transmit signals and information to / from the processor 80. Therefore, the memory 70 can store programs for programming a series of processes for transferring multiple microLEDs from the first substrate to the second substrate.

[0064] According to an embodiment, the processor 80 can be disposed in the first transfer device 1 and can control the overall operation of the first transfer device 1. In other words, the processor 80 is electrically connected to the transfer unit 10, the stage 40, the mask unit 50, and the laser light source unit 60, respectively, and can control each configuration.

[0065] For example, the processor 80 can control the transfer unit 10 to transfer the mask unit 50 to any position on the XY plane above the first substrate 20, and rotate the mask unit 50 to a desired angle. Furthermore, the processor 80 can move the stage 40 to any position on the XY plane and move the stage 40 in the upward and downward directions. Additionally, the processor 80 can control the laser light source unit 60 to scan a laser beam toward a preset point on the first substrate 20.

[0066] Although this disclosure describes all configurations controlled by a single processor 80, this disclosure is not limited thereto, and each configuration may be controlled by multiple independent processors.

[0067] According to an embodiment, processor 80 includes processing circuitry and may include one or more of, for example, a central processing unit (CPU), a controller, an application processor (AP), a communication processor (CP), and an ARM processor. Processor 80 is electrically connected to memory 70 and can use multiple pieces of information and a program for micro-LED transfer stored in memory 70. The specific functions of processor 80 according to embodiments of this disclosure will now be described.

[0068] Figure 3 A mask unit of a first transfer device according to an embodiment is shown.

[0069] According to the embodiments, such as Figure 1 As shown, the mask unit 50 can be disposed between the first substrate 20 and the laser source unit 60. The mask unit 50 can be moved to any position on the XY plane by the fixing member 11 and the guiding member 12 of the transfer unit 10, and can rotate clockwise and / or counterclockwise around the Z axis.

[0070] refer to Figure 3 According to an embodiment, the mask unit 50 can be formed in a substantially flat plate shape, and a plurality of apertures S can be formed at regular intervals in the X-axis and Y-axis directions, so that a laser beam can pass through the plurality of apertures S. The plurality of apertures S formed in the mask unit 50 can have various sizes or shapes through which a laser beam can pass to transfer the micro-LEDs 21 on the first substrate 20 to the second substrate 30.

[0071] According to an embodiment, a plurality of openings S can be arranged with a first spacing P1 in the X-axis direction and with a second spacing P2 in the Y-axis direction. In this case, the first spacing P1 and the second spacing P2 can have the same length or different lengths. Here, the first spacing P1 and the second spacing P2 can be configured in various ways, from tens of μm to hundreds of μm, according to user settings. The plurality of openings S can be located at corresponding positions in odd-numbered rows and at corresponding positions in even-numbered rows, and the odd-numbered rows and even-numbered rows can be arranged to be staggered from each other. Furthermore, the plurality of openings S can be configured to form an arrangement capable of transferring a plurality of microLEDs in a diagonal direction based on the microLED transfer method according to this disclosure.

[0072] According to an embodiment, the mask unit 50 is formed of a material that the laser beam cannot penetrate and may have heat resistance to withstand the laser beam. Furthermore, a heat-resistant material capable of withstanding the high heat of the laser beam may be applied to a surface of the mask unit 50 facing the laser source unit 60.

[0073] According to an embodiment, the mask unit 50 can selectively open openings based on the control of the processor 80. When the laser source unit 60 scans the laser beam through the opened openings of the mask unit 50, each microLED located on the first substrate 20 at a position corresponding to the opening can be separated from the lower surface of the first substrate 20 by the laser beam and transferred to the upper surface of the second substrate 30. In this case, due to the high heat of the laser beam, the anode and cathode electrodes of each microLED can be physically and / or electrically connected to the anode electrode pads and cathode electrode pads of the second substrate 30, respectively.

[0074] Figure 4 A first substrate used in a first transfer apparatus according to an embodiment is shown. Figure 5 It shows Figure 4 An enlarged view of the first region of the first substrate. Figure 6 It shows Figure 5 Enlarged views of parts A and B of the first region, and Figure 7 A second substrate used in a first transfer apparatus according to an embodiment is shown.

[0075] refer to Figure 4 According to an embodiment, the first substrate 20 may be a wafer, and a plurality of micro-LEDs 21 may be formed thereon. The plurality of micro-LEDs 21 may have different properties due to the process conditions and / or environment during the formation process on the first substrate 20. For example, as... Figure 4 As shown, the performance (color, brightness, etc.) of the micro-LEDs gradually decreases from the center region of the first substrate 20 toward the outer edge.

[0076] exist Figure 4 In this context, the performance distribution of the multiple micro-LEDs formed on the first substrate 20 is represented as a stepped form. Figure 4 In this context, the performance distribution of microLEDs for each region (e.g., the first region to the fourth region) of the first substrate 20 is represented by a plurality of rectangular shapes whose radial dimensions gradually increase from the rectangular shape indicated at the center of the first substrate 20. However, this is only for ease of description. The performance distribution of microLEDs on the first substrate 20 can be represented as a stepped structure in the form of a circle, an ellipse, or an irregular closed curve. Furthermore, the region with good microLED performance does not necessarily correspond to the central portion of the first substrate and can be located off-center on the first substrate 20.

[0077] According to the embodiments, such as Figure 4As shown, the first substrate 20 can be divided into multiple virtual regions to transfer multiple microLEDs to the second substrate 30. This division of virtual regions can be performed by a processor 80 and a vision camera (not shown) that can be disposed in the microLED transfer device according to this disclosure. In this case, the information on the virtual regions divided on the first substrate 20, and the coordinate information of the multiple microLEDs disposed in each virtual region, can be stored in the memory 70.

[0078] Figure 5 A first region is shown, which is a diagram illustrating the first region in a state where the first substrate 20 is flipped upside down so that the surfaces of the multiple microLEDs are facing downwards. Figure 5 In this diagram, multiple micro-LEDs 21 are covered by the first substrate 20 due to the first substrate 20 being flipped upside down. In this case, the micro-LEDs are usually shown as dashed lines, but for ease of description, they are shown as solid lines. The first region in the flipped-up state is shown considering that laser transfer is performed with the micro-LEDs on the first substrate 20 facing the second substrate 30.

[0079] refer to Figure 5 According to an embodiment, in the first region, the micro-LED with the highest performance can be located in the upper left portion, and the micro-LED with the lowest performance can be gradually positioned in the radial direction from the upper left portion toward the lower right portion.

[0080] According to the embodiments, such as Figure 6 As shown, in the first region, the anode and cathode electrodes of some of the micro-LEDs 21a, and the anode and cathode electrodes of the remaining micro-LEDs 21b, can be formed to be arranged opposite to each other. Therefore, when the electrodes of the micro-LEDs 21a and 21b are arranged at 0 degrees (°) and 180 degrees (°) respectively, the second substrate 30 can be configured such that all the anode pads and cathode pads are in the same direction (e.g., the 0-degree (°) direction).

[0081] like Figure 7 As shown, the micro-LEDs transferred to the second substrate 30 can form a pixel using three types of micro-LEDs: red (R), green (G), and blue (B). Therefore, the anode electrode pads and cathode electrode pads disposed on the second substrate 30 can be arranged adjacent to each other in three pairs as a unit, and other pixels disposed around a single pixel can be disposed at regular intervals from that single pixel.

[0082] According to an embodiment, the laser light source unit 60 can irradiate the rear surface of the first substrate 20, where no microLEDs 21 are formed, with a laser beam to peel off the microLEDs 21. For example, heat from the laser beam output from the laser light source unit 60 can be transferred to the adhesive layer 22 disposed between the microLEDs 21 and the first substrate 20. As the adhesive force of the adhesive layer 22 decreases due to the heat, the microLEDs 21 can be separated from the first substrate 20 and transferred to the transfer area of ​​the second substrate 30.

[0083] According to an embodiment, the microLED 21 transferred to the second substrate 30 can be physically and / or electrically connected to the anode electrode pads and cathode electrode pads of the second substrate 30, respectively, via an anode electrode and a cathode electrode. In this case, the anode electrode pads and cathode electrode pads of the second substrate 30 can be connected to the anode and cathode electrodes of the microLED 21 simultaneously as the irradiated laser beam deforms from a solid state to a molten state.

[0084] According to an embodiment, the micro-LED transfer system of this disclosure may include at least one of a first transfer device 1 for transferring a micro-LED 21 to a second substrate 30, and a second transfer device 2 for transferring a micro-LED 21 to the second substrate 30. At least one of the first transfer device 1 or the second transfer device 2 can transfer the micro-LED 21 onto the second substrate 30, which has an irregular shape. For example, the second substrate 30 to which the micro-LED 21 of this disclosure is transferred may be a substrate with an irregular shape.

[0085] The following text will refer to Figures 8 to 15 A method for transferring a microLED to an irregular target substrate of a microLED transfer system according to embodiments of the present disclosure is described.

[0086] Figure 8 The micro-LED transfer operation sequence of the first transfer device 1 according to the embodiment is shown. Figure 9 A mask unit 50 including a curved portion according to an embodiment is shown, and Figure 10 A mask unit 50, which moves and rotates under the control of a processor according to an embodiment, is shown.

[0087] According to an embodiment, the first transfer device 1 may include a first laser source unit 60 that irradiates a first substrate 20 on which a micro-LED 21 is disposed, a mask unit 50 disposed between the first substrate 20 and the first laser source unit 60 and selectively opening and closing at least one opening, and a first processor that controls the mask unit 50 to open and close the opening corresponding to the micro-LED 21 transferred to the second substrate 30.

[0088] refer to Figure 8According to an embodiment, the first transfer device 1 can form an irregularly shaped laser beam by moving and rotating the mask unit 50, which includes a curved portion (operation 810), and transfer the micro-LED 21 to the second substrate 30 (operation 820).

[0089] According to an embodiment, in operation 810, the first transfer device 1 can form an irregularly shaped laser beam by moving and rotating the mask unit 50, which includes a curved portion. Figure 9 As shown, mask unit 50a may include a curved portion with a predetermined curvature. For example, mask unit 50a may have a quadrant shape including the curved portion. However, the shape of mask unit 50 of this disclosure is not limited thereto, and the shape of mask unit 50 may include various shapes with curved portions (e.g., semi-circular shape and elliptical shape).

[0090] According to an embodiment, the first transfer device 1 can move and rotate the mask unit 50 by controlling the transfer unit 10. For example, the processor 80 can control the transfer unit 10 to move the mask unit 50 to any position on the XY plane above the first substrate 20. For example, the processor 80 can control the transfer unit 10 to rotate the mask unit 50 clockwise or counterclockwise above the first substrate 20.

[0091] According to an embodiment, the first transfer device 1 can form an irregularly shaped laser beam by passing the laser beam through multiple openings S of the moved and rotated mask unit 50. For example... Figure 10 As shown, the first transfer device 1 can rotate the mask unit 50a clockwise (R1) by 90 degrees (°), rotate the mask unit 50a counterclockwise (R2) by 90 degrees (°), or rotate the mask unit 50a clockwise or counterclockwise (R3) by 180 degrees (°). For example, the first transfer device 1 can form a circular laser beam by moving and rotating the mask unit 50a, which has a quadrant shape.

[0092] According to an embodiment, in operation 820, the first transfer device 1 can transfer the micro-LED 21 to the second substrate 30. For example, when the first transfer device 1 scans an irregularly shaped laser beam onto the first substrate 20 by moving and rotating the mask unit 50, each micro-LED 21 at a position on the first substrate 20 corresponding to the opening of the mask unit 50 can be separated from the lower surface of the first substrate 20 by the laser beam and transferred to the upper surface of the second substrate 30. In this case, due to the high heat of the laser beam, the anode electrode and cathode electrode of each micro-LED 21 can be physically and / or electrically connected to the anode electrode pad and cathode electrode pad of the second substrate 30, respectively.

[0093] According to embodiments, the microLED transfer system and method of the present disclosure can transfer microLEDs 21 onto a target substrate with an irregular shape by moving and rotating a mask unit 50 including a curved portion. Therefore, the microLED transfer system and method of the present disclosure can effectively transfer microLEDs 21 onto a target substrate with an irregular shape suitable for display devices of various shapes.

[0094] Figure 11 The micro-LED transfer operation sequence of the first transfer device 1 according to the embodiment is shown, and Figure 12 The laser beam is shown passing through the first and second masks in sequence.

[0095] According to an embodiment, the first transfer device 1 may include a first laser source unit 60 that irradiates a first substrate 20 on which a micro-LED 21 is disposed, a mask unit 50 disposed between the first substrate 20 and the first laser source unit 60 and selectively opening and closing at least one opening, and a first processor that controls the mask unit 50 to open and close the opening corresponding to the micro-LED 21 transferred to the second substrate 30.

[0096] refer to Figure 11 According to an embodiment, the first transfer device 1 can use a first mask to form an irregularly shaped laser beam (operation 1110), use a second mask to scan the laser beam onto the first substrate 20 (operation 1120), and transfer the micro-LED 21 to the second substrate 30 (operation 1130).

[0097] According to an embodiment, in operation 1110, the first transfer device 1 can use a first mask to form an irregularly shaped laser beam. The mask unit 50 may include a first mask for shaping the laser beam and a second mask for scanning the laser beam onto the first substrate 20.

[0098] refer to Figure 12 The first mask may be disposed above the second mask. For example, the first mask may be a blind mask. The first mask may include a shaping opening for shaping the laser beam Z1 incident from the laser source unit 60 into a predetermined shape. For example, the first mask may include a shaping opening having at least one shape selected from rectangle, triangle, circle, semicircle, or sector.

[0099] According to an embodiment, the first transfer device 1 can form an irregularly shaped laser beam Z2 by moving and rotating a first mask. For example, the first mask can be moved and rotated by the transfer unit 10, and the laser beam Z1 can be shaped into various shapes according to a combination of shaping openings with different shapes. For example, the first transfer device 1 can use the first mask to shape the laser beam Z1 into a laser beam Z2 having various shapes including circular, semi-circular, fan-shaped, and / or curved portions.

[0100] According to an embodiment, in operation 1120, the first transfer device 1 can use a second mask to scan a laser beam onto the first substrate 20. For example, the first transfer device 1 can scan a shaped laser beam Z2, which is being shaped while passing through the first mask, through an open opening in the second mask, onto a micro-LED 21 on the first substrate 20 at a position corresponding to the opening.

[0101] According to an embodiment, in operation 1130, the first transfer device 1 can transfer the micro-LED 21 to the second substrate 30. For example, when the first transfer device 1 scans a laser beam shaped by a first mask and a second mask onto the first substrate 20, the micro-LED 21 on the first substrate 20 corresponding to the shaped laser beam can be separated from the lower surface of the first substrate 20 by the laser beam and transferred to the upper surface of the second substrate 30. In this case, due to the high heat of the laser beam, the anode electrode and cathode electrode of each micro-LED 21 can be physically and / or electrically connected to the anode electrode pad and cathode electrode pad of the second substrate 30, respectively.

[0102] According to embodiments, the microLED transfer system and method of this disclosure can transfer a microLED 21 onto a target substrate with an irregular shape by shaping a laser beam using a first mask and scanning the laser beam onto a wafer using a second mask. Therefore, the microLED transfer system and method of this disclosure can effectively transfer a microLED 21 onto a target substrate with an irregular shape suitable for display devices of various shapes.

[0103] Figure 13 The sequence of micro-LED transfer operations of the first transfer device 1 and the second transfer device 2 according to the embodiment is shown. Figure 14 The first and second regions of the second substrate 30 are shown, and Figure 15 A second transfer device 2 is shown in a miniature LED transfer system according to an embodiment.

[0104] refer to Figure 13According to an embodiment, the micro-LED transfer system can use a first transfer device 1 to transfer a micro-LED 21 to a first region of a second substrate 30 (operation 1310), and use a second transfer device 2 to transfer the micro-LED 21 to a second region of the second substrate 30 (operation 1320).

[0105] According to an embodiment, the first transfer device 1 can transfer the micro-LED 21 to the second substrate 30 in a multi-transfer manner. Furthermore, the second transfer device 2 can transfer the micro-LED 21 to the second substrate 30 one at a time.

[0106] refer to Figure 14 According to an embodiment, the second substrate 30 may be a substrate with an irregular shape (e.g., a circular shape). The transfer region of the second substrate 30 may be divided into a first region 31 and a second region 32. For example, the second substrate 30 may include a first region 31 containing a non-curved region and a second region 32 containing a curved region. The first region 31 is a transfer region formed on the inner side of the second substrate 30 and may be a region with a regular shape (e.g., a rectangular shape). The second region 32 is a transfer region formed on the edge of the second substrate 30 and may be a region with an irregular shape (e.g., a shape including a curved portion). For example, the second region 32 may be a region surrounding the first region 31.

[0107] According to an embodiment, in operation 1310, the micro-LED transfer system can use the first transfer device 1 to transfer the micro-LED 21 to a first region of the second substrate 30.

[0108] According to an embodiment, the first transfer device 1 may include a first laser source unit 60 that irradiates a first substrate 20 on which a micro-LED 21 is disposed, a mask unit 50 disposed between the first substrate 20 and the first laser source unit 60 and selectively opening and closing at least one opening, and a first processor that controls the mask unit 50 to open and close the opening corresponding to the micro-LED 21 transferred to the second substrate 30.

[0109] According to an embodiment, the first transfer device 1 can rapidly transfer the micro-LEDs 21 to a first region 31 with a regular shape (e.g., a rectangular shape) in multiple transfers. For example, when the first laser light source unit 60 scans the laser beam onto the first substrate 20 through the mask unit 50, each micro-LED 21 at the position corresponding to the opening of the mask unit 50 on the first substrate 20 can be separated from the lower surface of the first substrate 20 by the laser beam and transferred to the first region 31 of the second substrate 30.

[0110] According to an embodiment, in operation 1320, the micro-LED transfer system can use the second transfer device 2 to transfer the micro-LED 21 to the second region 32 of the second substrate 30. For example, after the first transfer device 1 transfers the micro-LED 21 to the first region 31 of the second substrate 30, the second transfer device 2 can sequentially transfer the micro-LED 21 to the second region 32 of the second substrate 30.

[0111] According to an embodiment, the second transfer device 2 may include a second laser source unit 60 that outputs a laser beam, a path changing unit 13 that changes the path of the laser beam, and a second processor that controls the path changing unit 13 to change the path of the laser beam toward the micro-LED 21 transferred to the second substrate 30.

[0112] According to an embodiment, the second transfer device 2 can precisely transfer the micro-LEDs 21 to a second region 32 with an irregular shape (e.g., a shape including curved portions) in a one-to-one transfer manner. For example, as Figure 15 As shown, the second laser source unit 60 can output a laser beam to the path changing unit 13. The path changing unit 13 can quickly change the path of the laser beam Z emitted from the second laser source unit 60, and change the point source laser beam into a near-area source or line source.

[0113] According to an embodiment, the path changing unit 13 can change the laser beam Z output from the second laser source unit 60 in units of ms, μ (microseconds), and ns (nanoseconds), and irradiate the laser beam Z onto a predetermined position on the first substrate 20 where the micro-LED 21 is disposed. Here, since the laser beam Z changed by the path changing unit 13 irradiates the first substrate 20 in units of ms, μ (microseconds), and ns (nanoseconds), the micro-LED 21 can transfer to the second region 32 of the second substrate 30 at the same time as it separates from the first substrate 20.

[0114] For example, the path changing unit 13 may include a galvano mirror. The galvano mirror can be a device capable of rapidly changing the path of the light source by quickly rotating a mirror surface that reflects the light source. Figure 15 As shown, the second processor can change the path of the laser beam Z by controlling the path changing unit 13 in preset rotation directions R1 and R2 based on the position information of the second region 32 to be transferred, so that the micro LED 21 can be transferred to the second region 32. For example, the laser beam Z can be reflected sequentially by a galvanometer and scanned onto the first substrate 20 through the first laser path Z1 and the second laser path Z2, so that the micro LED 21 can be accurately transferred to the second region 32 of the second substrate 30.

[0115] According to embodiments, the microLED transfer system and method of this disclosure can transfer the microLED 21 to an irregularly shaped target substrate by transferring the microLED 21 to the non-bent portion of the target substrate using a first transfer device 1 in a multiple-transfer manner, and transferring the microLED 21 to the bent portion of the target substrate using a second transfer device 2 in a one-to-one transfer manner. Therefore, the microLED transfer system and method of this disclosure can effectively transfer the microLED 21 to an irregularly shaped target substrate suitable for display devices of various shapes.

[0116] The various embodiments in this document and the terminology used herein are not intended to limit the technical features described herein to the specific embodiments, and should be understood to include various modifications, equivalents, or substitutions, including the corresponding embodiments. As used herein, the singular forms “a” and “the” are intended to include the plural forms as well, unless the context explicitly indicates otherwise. As used herein, the term “and / or” should be understood to cover any and all possible combinations of one or more of the listed items. As used herein, the terms “comprising,” “having,” and “including” are used only to indicate the presence of the features, components, portions, or combinations thereof described herein, but the use of such terms does not preclude the possibility of the presence or addition of one or more other features, components, portions, or combinations thereof. As used herein, each of phrases such as “A or B,” “at least one of A and B,” “at least one of A or B,” “A, B, or C,” “at least one of A, B, and C,” and “at least one of A, B, or C” can include all possible combinations of the items listed together in the corresponding phrases within these phrases. As used herein, terms such as “first” and “second” or “first” and “second” can be used to simply distinguish corresponding components from other components without limiting the components in other ways (e.g., importance or order).

[0117] As used herein, the terms “part” or “module” can include a unit implemented in hardware, software, or firmware, and are used interchangeably with other terms such as “logic,” “logic block,” “component,” or “circuit.” A part or module can be a single integrated component or its smallest unit or portion thereof adapted to perform one or more functions. For example, according to an embodiment, a “part” or “module” can be implemented in the form of an application-specific integrated circuit (ASIC).

[0118] As used in the various embodiments of this disclosure, the term "if" may be interpreted, depending on the context, as "when," "at," "in response to determining," or "in response to detecting." Similarly, "if A is determined" or "if A is detected" may be interpreted, depending on the context, as "when A is determined," "in response to determining A," or "when A is detected," or "in response to detecting A."

[0119] The program executed by the transfer device as described herein can be implemented as a hardware component, a software component, and / or a combination thereof. The program can be executed by any system capable of executing computer-readable instructions.

[0120] The software may include computer programs, code, instructions, or combinations thereof, and may configure processing devices as desired when it operates, or may instruct processing devices independently or collectively. The software may be implemented as a computer program including instructions stored in a computer-readable storage medium. Computer-readable storage media may include, for example, magnetic storage media (e.g., read-only memory (ROM), random access memory (RAM), floppy disk, hard disk, etc.) and optically readable media (e.g., CD-ROM or digital versatile optical disc (DVD)). Furthermore, computer-readable storage media may be distributed to computer systems connected via a network, and computer-readable code may be stored and executed in a distributed manner. The computer program may be distributed (e.g., downloaded or uploaded) via an app store (e.g., Play Store™), directly between two UEs (e.g., smartphones), or online. If distributed online, at least a portion of the computer program product may be temporarily generated or at least temporarily stored in a machine-readable storage medium (e.g., the memory of a manufacturer's server, an app store's server, or a relay server).

[0121] According to various embodiments, each of the above components (e.g., a module or program) may include a single entity or multiple entities. Some of the multiple entities may be separately located in different components. According to various embodiments, one or more of the above components may be omitted, or one or more other components may be added. Alternatively or additionally, multiple components (e.g., modules or programs) may be integrated into a single component. In such cases, according to various embodiments, the integrated component may still perform one or more functions of each of the multiple components in the same or similar manner as they were performed by the corresponding components of the multiple components before integration. According to various embodiments, operations performed by a module, program, or other component may be performed sequentially, in parallel, repeatedly, or heuristically, or one or more of the operations may be performed in a different order or omitted, or one or more other operations may be added.

Claims

1. A miniature light-emitting diode (LED) transfer system, comprising: At least one of a first transfer device and a second transfer device, wherein the first transfer device transfers a microLED to a second substrate, and the second transfer device transfers the microLED to the second substrate, wherein the first transfer device includes: The first laser source unit irradiates a laser beam onto a first substrate on which the micro-LEDs are disposed; A mask unit is disposed between the first substrate and the first laser source unit, and selectively opens and closes at least one opening; and A first processor, including processing circuitry, controls the mask unit to open and close openings corresponding to the microLEDs transferred to the second substrate. In this embodiment, at least one of the first transfer device or the second transfer device is configured to transfer the microLED to the second substrate having an irregular shape.

2. The micro LED transfer system according to claim 1, wherein, The mask unit includes a curved portion with a predetermined curvature, and The first processor is configured to form an irregularly shaped laser beam by moving and rotating the mask unit.

3. The micro LED transfer system according to claim 2, wherein, The mask unit has a quadrant shape including the curved portion, and The first processor is configured to form a circular laser beam by moving and rotating the mask unit.

4. The micro LED transfer system according to any one of claims 1 to 3, wherein, The mask unit includes: A first mask is used to shape the laser beam; and A second mask is used to scan the laser beam onto the first substrate.

5. The micro LED transfer system according to claim 4, wherein, The first mask includes a shaping opening having at least one shape among rectangle, triangle, circle, semicircle and sector.

6. The micro LED transfer system according to claim 4, wherein, The first processor is configured to form an irregularly shaped laser beam by moving and rotating the first mask.

7. The micro LED transfer system according to any one of claims 1 to 6, wherein, The first transfer device is configured to transfer the microLED to the second substrate in a multi-transfer manner, and The second transfer device is configured to transfer the microLEDs to the second substrate in a one-to-one transfer manner.

8. The micro LED transfer system according to any one of claims 1 to 7, wherein, The second transfer device includes: The second laser source unit outputs a laser beam; A path-changing unit that changes the path of the laser beam; and The second processor controls the path-changing unit to change the path of the laser beam toward the microLED transferred to the second substrate.

9. The micro LED transfer system according to claim 8, wherein, The first transfer device is configured to transfer the microLED to a first region of the second substrate, and The second transfer device is configured to transfer the microLED to a second region of the second substrate.

10. The micro LED transfer system according to claim 9, wherein, The first region includes the non-bent region of the second substrate, and The second region includes the curved region of the second substrate.

11. A method for transferring micro-LEDs, comprising: The micro-LEDs are transferred to the second substrate using the first transfer device; as well as The microLED is transferred to the second substrate using a second transfer device, wherein transferring the microLED to the second substrate using the first transfer device includes: A laser beam is irradiated onto a first substrate on which the microLEDs are disposed using a first laser light source unit; At least one opening is selectively opened and closed using a mask unit disposed between the first substrate and the first laser source unit; and The first processor controls the mask unit to open and close the openings corresponding to the microLEDs transferred to the second substrate, and In this embodiment, at least one of the first transfer device and the second transfer device is configured to transfer the microLED to the second substrate having an irregular shape.

12. The micro-LED transfer method according to claim 11, wherein, The mask unit includes a curved portion with a predetermined curvature, and The use of the first processor to control the mask unit includes: forming an irregularly shaped laser beam by moving and rotating the mask unit.

13. The micro-LED transfer method according to claim 12, wherein, The mask unit has a quadrant shape including the curved portion, and The use of the first processor to control the mask unit includes: forming a circular laser beam by moving and rotating the mask unit.

14. The micro-LED transfer method according to any one of claims 11 to 13, wherein, Selectively opening and closing at least one opening using the mask unit includes: The laser beam is shaped using a first mask; and The laser beam is scanned onto the first substrate using a second mask.

15. The micro-LED transfer method according to claim 14, wherein, The first mask includes a shaping opening having at least one shape among rectangle, triangle, circle, semicircle and sector.

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