Micro-led transfer system and micro-led transfer method using same

Abstract

A micro-LED transfer system according to embodiments of the present disclosure may comprise a first transfer device for transferring a micro-LED to a second substrate, and / or a second transfer device for transferring the micro-LED to the second substrate. The first transfer device can include: a first laser light source unit for irradiating, with a laser beam, the first substrate on which the micro-LED is disposed; a mask unit which is disposed between the first substrate and the first laser light source unit, and which selectively opens and closes 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 can transfer the micro-LED to the second substrate, which has an irregular shape.

Description

Micro LED transfer system and micro LED transfer method using the same

[0001] Various embodiments of the present disclosure relate to a micro LED transfer system for transferring a plurality of micro LEDs (Micro Light Emitting Diodes) formed on a wafer to a printed circuit board of a display panel, and a micro LED transfer method using the same.

[0002] Micro LEDs are ultra-small inorganic light-emitting materials that emit light on their own without color filters or backlights. Specifically, micro LEDs can refer to ultra-small LEDs that are about one-tenth the length and one-hundredth the area of ​​a standard light-emitting diode (LED) chip, with dimensions of 10㎛ to 100㎛ in width, length, and height.

[0003] Micro LEDs can be manufactured in the form of chips on a wafer and placed on a target substrate to form a light-emitting module of a display. The process of placing micro LEDs on a target substrate is a process that efficiently transfers micro LEDs into space on the substrate and electrically or physically connects them to the substrate, and is a key process in the manufacture of micro LED display modules.

[0004] Meanwhile, with the recent release of various types of display devices, such as wearable devices, there is a need for technology that can efficiently transfer micro LEDs onto various types of target substrates.

[0005] Various embodiments of the present disclosure may provide a micro LED transfer system and a micro LED transfer method using the same, which efficiently transfers a micro LED onto an irregularly shaped target substrate by using at least one of a first transfer device and a second transfer device.

[0006] A micro LED transfer system according to embodiments of the present disclosure may include at least one of a first transfer device for transferring a micro LED to a second substrate and a second transfer device for transferring the micro LED to the second substrate. The first transfer device may include a first laser light source unit for irradiating a laser beam onto a first substrate on which the micro LED is disposed, a mask unit disposed between the first substrate and the first laser light source unit and selectively opening and closing at least one aperture, and a first processor for controlling the mask unit to open and close the aperture corresponding to the micro LED transferred to the second substrate. At least one of the first transfer device or the second transfer device may transfer the micro LED to the second substrate having an irregular shape.

[0007] In one embodiment, the mask unit may include a curved portion having a predetermined curvature. The first processor can form an irregular laser beam by moving and rotating the mask unit.

[0008] In one embodiment, the mask unit may have a quadrant shape including the curved portion. The first processor may form a circular laser beam by moving and rotating the mask unit.

[0009] In one embodiment, the mask unit may include a first mask for shaping the laser beam and a second mask for scanning the laser beam onto the first substrate.

[0010] In one embodiment, the first mask may include a molded opening having at least one shape among a square, a triangle, a circle, a semicircle, and a quarter circle.

[0011] In one embodiment, the first processor can form an irregular laser beam by moving and rotating the first mask.

[0012] In one embodiment, the first transfer device can transfer the micro LED to the second substrate using a multi-transfer method. The second transfer device can transfer the micro LED to the second substrate using a one-by-one transfer method.

[0013] In one embodiment, the second transfer device may include a second laser light 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 in the direction of the micro LED transferred to the second substrate.

[0014] In one embodiment, the first transfer device can transfer the micro LED to a first area of ​​the second substrate. The second transfer device can transfer the micro LED to a second area of ​​the second substrate.

[0015] In one embodiment, the first region may include a non-curved region of the second substrate. The second region may include a curved region of the second substrate.

[0016] A micro LED transfer method according to embodiments of the present disclosure may include an operation of transferring a micro LED to a second substrate using a first transfer device, and an operation of transferring the micro LED to the second substrate using a second transfer device. The operation of transferring the micro LED to the second substrate using the first transfer device may include an operation of irradiating a laser beam onto a first substrate on which the micro LED is placed using a first laser light source unit, an operation of selectively opening and closing at least one opening using a mask unit disposed between the first substrate and the first laser light source unit, and an operation of controlling the mask unit to open and close the opening corresponding to the micro LED transferred to the second substrate using a first processor. At least one of the first transfer device or the second transfer device may transfer the micro LED to the second substrate having an irregular shape.

[0017] In one embodiment, the mask unit may include a curved portion having a predetermined curvature. The operation of controlling the mask unit using the first processor can form an irregular laser beam by moving and rotating the mask unit.

[0018] In one embodiment, the mask unit may have a quadrant shape including the curved portion. The operation of controlling the mask unit using the first processor may form a circular laser beam by moving and rotating the mask unit.

[0019] In one embodiment, the operation of selectively opening and closing at least one opening using the mask unit may include the operation of shaping the laser beam using the first mask and the operation of scanning the laser beam onto the first substrate using the second mask.

[0020] In one embodiment, the first mask may include a molded opening having at least one shape among a square, a triangle, a circle, a semicircle, and a quarter circle.

[0021] In one embodiment, the operation of controlling the mask unit using the first processor can form an irregular laser beam by moving and rotating the first mask.

[0022] In one embodiment, the first transfer device can transfer the micro LED to the second substrate using a multi-transfer method. The second transfer device can transfer the micro LED to the second substrate using a one-by-one transfer method.

[0023] In one embodiment, the operation of transferring the micro LED to the second substrate using the second transfer device may include the operation of outputting a laser beam using a second laser light source, the operation of changing the path of the laser beam using a path changing unit, and the operation of controlling the path changing unit to change the path of the laser beam in the direction of the micro LED transferred to the second substrate using a second processor.

[0024] In one embodiment, the operation of transferring the micro LED to the second substrate using the first transfer device may transfer the micro LED to a first area of ​​the second substrate. The operation of transferring the micro LED to the second substrate using the second transfer device may transfer the micro LED to a second area of ​​the second substrate.

[0025] In one embodiment, the first region may include a non-curved region of the second substrate. The second region may include a curved region of the second substrate.

[0026] According to various embodiments of the present disclosure, the micro LED transfer system and the micro LED transfer method using the same can transfer a micro LED onto an irregular target substrate by moving and rotating a mask unit including a curved portion.

[0027] In addition, the micro LED transfer system and the micro LED transfer method using the same disclosed in the present disclosure can transfer a micro LED onto an irregular target substrate by forming a laser beam with a first mask and injecting a laser beam onto a wafer with a second mask.

[0028] In addition, the micro LED transfer system and the micro LED transfer method using the same disclosed in the present disclosure can transfer a micro LED onto an irregular target substrate by transferring a micro LED onto a non-curved portion of a target substrate using a first transfer device of a multi-transfer method and transferring a micro LED onto a curved portion of a target substrate using a second transfer device of a 1-by-1 transfer method.

[0029] Accordingly, the micro LED transfer system of the present disclosure and the micro LED transfer method using the same can efficiently transfer micro LEDs to an amorphous target substrate applicable to display devices having various shapes.

[0030] The effects obtainable from the exemplary embodiments of the present disclosure are not limited to those mentioned above, and other unmentioned effects can be clearly derived and understood by those skilled in the art to which the exemplary embodiments of the present disclosure belong from the description below. That is, unintended effects resulting from the implementation of the exemplary embodiments of the present disclosure can also be derived by those skilled in the art from the exemplary embodiments of the present disclosure.

[0031] FIG. 1 illustrates a first transfer device of a micro LED transfer system according to one embodiment.

[0032] FIG. 2 illustrates a partial block configuration of a first transfer device according to one embodiment.

[0033] FIG. 3 illustrates a mask unit of a first transfer device according to one embodiment.

[0034] FIG. 4 illustrates a first substrate used in a first transfer device according to one embodiment.

[0035] FIG. 5 illustrates an enlarged view of the first region of the first substrate of FIG. 4.

[0036] Figure 6 illustrates parts A and B of the first region of Figure 5 in enlarged view.

[0037] FIG. 7 illustrates a second substrate used in a first transfer device according to one embodiment.

[0038] FIG. 8 illustrates the sequence of micro LED transfer operations of a first transfer device according to one embodiment.

[0039] FIG. 9 illustrates a mask unit including a curved portion according to one embodiment.

[0040] FIG. 10 illustrates a mask unit that moves and rotates under the control of a processor according to one embodiment.

[0041] FIG. 11 illustrates the sequence of micro LED transfer operations of a first transfer device according to one embodiment.

[0042] FIG. 12 illustrates a laser beam passing sequentially through a first mask and a second mask.

[0043] FIG. 13 illustrates the sequence of micro LED transfer operations of a first transfer device and a second transfer device according to one embodiment.

[0044] FIG. 14 illustrates the first region and the second region of the second substrate.

[0045] FIG. 15 illustrates a second transfer device of a micro LED transfer system according to one embodiment.

[0046] Hereinafter, embodiments of the present disclosure are described in detail with reference to the drawings so that those skilled in the art can easily practice them. However, the present disclosure may be embodied in various different forms and is not limited to the embodiments described herein. In relation to the description of the drawings, the same or similar reference numerals may be used for identical or similar components. Furthermore, in the drawings and related descriptions, descriptions of well-known functions and configurations may be omitted for clarity and brevity.

[0047] FIG. 1 illustrates a micro LED transfer device according to one embodiment, and FIG. 2 illustrates a partial block configuration of a micro LED transfer device according to one embodiment.

[0048] Referring to FIGS. 1 and 2, a first transfer device (1) for transferring a micro LED according to one embodiment of the present disclosure may include a transfer unit (10) that supports a mask unit (20) so as to be movable on the upper side of a first substrate (20), a stage (40) on which a second substrate (30) is clampably seated and which moves the second substrate (30), a mask unit (50) that selectively passes a laser beam irradiated onto the first substrate (20), a laser light source unit (60) that irradiates a laser beam onto the first substrate (20), and a processor (80) that controls the transfer unit (10), the stage (40), and the mask unit (50), respectively.

[0049] The transfer unit (10) may include a fixed member (11) that supports the mask unit (50) so that the laser beam is directed toward the second substrate (30), and a guide member (12) to which the fixed member (11) is rotatably connected. Based on the coordinate system shown in FIG. 1, the fixed member (11) may be connected to the guide member (12) by a rotation axis (15) so that it can move along the X-axis direction through a slider (14). Additionally, the fixed member (11) may rotate clockwise or counterclockwise around a rotation axis (15) arranged along the Z-axis. The guide member (12) may be slidably connected to guide rails (not shown) arranged in the Y-axis direction so that the fixed member (11) can be moved in the Y-axis direction.

[0050] The mask unit (50) can be moved to any position on the XY plane by means of a fixed member (11) and a guide member (12), and can be rotated clockwise and counterclockwise with respect to the Z-axis. Although the fixed member (11) is illustrated as fixing the mask unit (50) by supporting the edge area of ​​the mask unit (50) as in FIG. 1, it is not limited thereto and can stably fix the mask unit (50) in various ways. For example, the mask unit (50) can be fixed by connecting the fixed member (11) to any part of the mask unit (50) through various clamping structures, such as a vacuum suction method. For convenience of explanation, the illustration of a driving device for rotating the fixed member (11) and a driving device for moving the guide member (12) is omitted in FIG. 1. The guide member (12) is positioned on the upper side of the second substrate (30) and can move the fixed member (11), which is connected to the mask unit (50), to any position on the XY plane relative to the second substrate (30). In addition, the guide member (12) can move the fixed member (11) through various structures such as a multi-joint structure, a piston structure, and a sliding structure.

[0051] 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 arranged. An adhesive layer (22) may be located on one side of the first substrate (20). The adhesive layer (22) may attach a plurality of micro LEDs (21) to the first substrate (20). Additionally, the adhesive layer (22) may be composed of a material that melts by a laser beam irradiated onto the first substrate (20) so that the micro LEDs (21) can be separated from the first substrate (20).

[0052] Micro LEDs (21) are made of inorganic light-emitting materials with a width, length, and height of 100 μm or less and can emit light on their own when power is supplied. Micro LEDs (21) are receiving attention as light-emitting devices for next-generation displays because they have a fast response speed, low power consumption, and high brightness. Specifically, Micro LEDs (21) can have a higher efficiency in converting electricity into photons compared to LCDs (liquid crystal displays) or OLEDs (optical light emitting diodes). Accordingly, Micro LEDs (21) can produce the same brightness with about half the energy compared to conventional LEDs or OLEDs. In addition, Micro LEDs (21) can achieve high resolution, excellent color, contrast, and brightness, allowing for accurate representation of a wide range of colors and enabling a clear screen even in bright sunlight outdoors. Furthermore, Micro LEDs (21) are resistant to burn-in and generate little heat, ensuring a long lifespan without deformation. Additionally, the micro LED (21) may include at least one of a red micro LED that emits red light, a green micro LED that emits green light, and a blue micro LED that emits blue light. Micro LEDs emitting light of the same color may be arranged on a single wafer. For example, if the first substrate (20) is a wafer, the first substrate (20) may be composed only of red micro LEDs that emit red light, only of green micro LEDs that emit green light, or only of blue micro LEDs that emit blue light.

[0053] 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 meaning of the remaining micro LEDs being positioned at 180 degrees (°) is that the anode electrode and cathode electrode of the remaining micro LEDs may be positioned in opposite directions relative to the anode electrode and cathode electrode of some micro LEDs. For example, all micro LEDs on a wafer may have their anode electrodes and cathode electrodes formed in the same direction.

[0054] The second substrate (30) may be a printed circuit board (PCB) applied to a display panel as a target substrate. Unlike the first substrate (20), the second substrate (30) may be made of various sizes and shapes. Additionally, the second substrate (30) may be a relay substrate that receives micro LEDs from the first substrate (20) and relays the micro LEDs to the printed circuit board of the display panel.

[0055] 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 to which each micro LED (21) is physically and electrically connected. The plurality of anode electrode pads and a plurality of cathode electrode pads of the second substrate (30) may vary in correspondence with the arrangement of anode electrodes and cathode electrodes of the plurality of micro LEDs arranged on the first substrate (20).

[0056] For example, if the remaining micro LEDs are positioned at 180 degrees (°) for some micro LEDs, a plurality of anode electrode pads and a plurality of cathode electrode pads on the second substrate (20) may all be positioned in the same direction. Additionally, if the anode electrodes and cathode electrodes of all micro LEDs are all formed in the same direction, a plurality of anode electrode pads and a plurality of cathode electrode pads on the second substrate (20) may have some positioned at 0 degrees (°) and the remainder at 180 degrees (°).

[0057] The stage (40) can support the second substrate (30) so that it is loaded and unloaded, and the second substrate (30) can be positioned parallel to the first substrate (20). The stage (40) can move relative to the transfer unit (10) while the second substrate (30) is loaded. That is, the stage (40) can move along the XY plane. In addition, the stage (40) can move up and down along the Z-axis direction. For convenience of explanation, the illustration of the respective driving devices for the XY plane movement and up and down movement of the stage (40) is omitted in FIG. 1.

[0058] The mask unit (50) is positioned between the laser light source unit (60) and the first substrate (20) so that a laser beam emitted from the laser light source unit (60) can pass over the first substrate (20). The specific structure of the mask unit (50) will be described later with reference to FIG. 3.

[0059] The laser light source (60) can lift off the multiple micro LEDs (21) by irradiating a laser beam toward the rear surface of the first substrate (20) where the multiple micro LEDs (21) are not formed. The micro LEDs (21) lifted off from the first substrate (20) by the laser beam can be transferred to the second substrate (30).

[0060] The laser light source (60) may include a lens member (e.g., P-lens) capable of directly irradiating a laser beam toward the first substrate (20) or appropriately changing the direction of the laser beam along the path where the laser beam is irradiated. The laser light source (60) may irradiate any one of a point laser beam, a line laser beam, or an area laser beam. For example, a point laser beam may be a laser beam irradiated toward a single point. For example, a line laser beam may be a laser beam irradiated along an arbitrary length along the X-axis or Y-axis. An area beam is a laser beam irradiated simultaneously over an arbitrary area, and the laser beam may be irradiated simultaneously or sequentially at multiple [X,Y] coordinate points. In this case, the area laser beam may be irradiated simultaneously or sequentially in multiple parallel diagonal directions over an arbitrary area.

[0061] The laser light source (60) may be part of a laser beam scanner not shown in the drawing, and the laser beam scanner may be included in a micro LED transfer device according to one embodiment of the present disclosure.

[0062] The memory (70) illustrated in FIG. 2 may be provided within the first transfer device (1). The memory (70) may be implemented as at least one of a flash memory type, ROM, RAM, hard disk type, multimedia card micro type, or card type memory (e.g., SD or XD memory). Additionally, the memory (70) is electrically connected to the processor (80) so that it can transmit signals and information to and from the processor (80). Accordingly, the memory (70) may store a program that programs a series of processes for transferring a plurality of micro LEDs from a first substrate to a second substrate.

[0063] A processor (80) may be provided within the first transfer device (1) and can control the overall operation of the first transfer device (1). That is, 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 of the above components.

[0064] For example, the processor (80) can control the transfer unit (10) to transfer the mask unit (50) to a position on any XY plane above the first substrate (20) and rotate it at a desired angle. Additionally, the processor (80) can move the stage (40) to a position on any XY plane and move it in the up and down direction. Additionally, the processor (80) can control the laser light source unit (60) to scan a laser beam toward a preset point toward the first substrate (20).

[0065] However, although the present disclosure describes controlling all configurations by a single processor (80), it is not limited thereto, and each configuration may be controlled using a plurality of independent processors.

[0066] The processor (80) may include one or more of a central processing unit (CPU), a controller, an application processor (AP), a communication processor (CP), or an ARM processor. The processor (80) is electrically connected to the memory (70) and can utilize a program for micro LED transfer and a number of information stored in the memory (70). Specific functions of the processor (80) according to one embodiment of the present disclosure will be described later.

[0067] FIG. 3 illustrates a mask unit of a first transfer device according to one embodiment.

[0068] The mask unit (50) can be positioned between the first substrate (20) and the laser light source (60) as shown in FIG. 1. The mask unit (50) can be moved to any position on the XY plane by means of the fixed member (11) and the guide member (12) of the transfer unit (10), and can be rotated clockwise and counterclockwise with respect to the Z-axis.

[0069] Referring to FIG. 3, the mask unit (50) may be formed in a roughly flat shape, and a plurality of openings (S) may be formed at regular intervals in the X-axis and Y-axis directions so that a laser beam can pass through. The plurality of openings (S) formed in the mask unit (50) may have various sizes or shapes through which a laser beam can pass to transfer a micro LED (21) on a first substrate (20) to a second substrate (30).

[0070] A plurality of apertures (S) may be arranged in a first pitch (P1) in the X-axis direction and in a second pitch (P2) in the Y-axis direction. In this case, the first pitch (P1) and the second pitch (P2) may have the same length or different lengths. Here, the first and second pitches (P1, P2) may be varied from tens of μm to hundreds of μm according to the user's settings. Among the plurality of apertures (S), odd rows may be at corresponding positions and even rows may be at corresponding positions, and the odd rows and even rows may be arranged offset from each other. Additionally, the plurality of apertures (S) may be arranged to form an array capable of transferring a plurality of micro LEDs in a diagonal direction according to the micro LED transfer method according to the present disclosure.

[0071] The mask unit (50) is made of a material through which the laser beam cannot pass and may have heat resistance for durability against the laser beam. Additionally, a heat-resistant material capable of withstanding the high heat of the laser beam may be applied to one side of the mask unit (50) facing the laser light source (60).

[0072] The mask unit (50) can selectively open openings based on the control of the processor (80). When the laser light source (60) scans a laser beam through the opened openings of the mask unit (50), each micro LED of the first substrate (20) located at a position corresponding to the openings can be separated from the bottom surface of the first substrate (20) by the laser beam and transferred to the top surface of the second substrate (30). At this time, the anode electrode and cathode electrode of each micro LED can be physically and electrically connected to the anode electrode pad and cathode electrode pad of the second substrate (30), respectively, due to the high heat of the laser beam.

[0073] FIG. 4 illustrates a first substrate used in a first transfer device according to one embodiment, FIG. 5 illustrates an enlarged view of a first region of the first substrate of FIG. 4, FIG. 6 illustrates an enlarged view of parts A and B of the first region of FIG. 5, and FIG. 7 illustrates a second substrate used in a first transfer device according to one embodiment.

[0074] Referring to FIG. 4, the first substrate (20) may be a wafer and may have a plurality of micro LEDs (21) formed thereon. During the process of forming the plurality of micro LEDs (21) on the first substrate (20), their performance may differ depending on the process conditions and environment. For example, as shown in FIG. 4, there may be a characteristic where the performance (color, brightness, etc.) of the micro LEDs gradually decreases from the central region of the first substrate (20) toward the outer edge.

[0075] In FIG. 4, the performance distribution of a plurality of micro LEDs formed on the first substrate (20) is expressed in the form of a gradient. In FIG. 4, the performance distribution of micro LEDs for each region (e.g., first to fourth regions) of the first substrate (20) is expressed as a plurality of squares that gradually increase in size radially from a square marked at the center of the first substrate (20), but this is only for convenience of explanation and the performance distribution of micro LEDs on the first substrate (20) may be expressed as a gradient in the form of a circle, an ellipse, or an irregular closed curve, and the region with good performance of micro LEDs may not necessarily correspond to the central part of the first substrate but may be located biased to one side on the first substrate (20).

[0076] As shown in FIG. 4, the first substrate (20) may divide a plurality of virtual regions on the first substrate (20) to transfer a plurality of micro LEDs to the second substrate (30). Dividing these virtual regions may be performed by a vision camera (not shown) and a processor (80) that may be provided in the micro LED transfer device (1) according to the present disclosure. In this case, information on the virtual regions divided on the first substrate (20) and coordinate information of a plurality of micro LEDs arranged in each virtual region may be stored in a memory (70).

[0077] FIG. 5 is a drawing showing the first region in which the first substrate (20) is flipped so that a plurality of micro LEDs face downward. In FIG. 5, the plurality of micro LEDs (21) are obscured by the first substrate (20) because the first substrate (20) is flipped. In this case, it is common to draw the micro LEDs as hidden lines, but for convenience of explanation, they are drawn as solid lines. The first region is drawn in this flipped state to account for laser transfer being performed when the micro LEDs of the first substrate (20) are positioned to face the second substrate (30).

[0078] Referring to Fig. 5, within the first region, the highest-performance micro LED is located in the upper left portion, and as one radiates from the upper left portion toward the lower right portion, the lowest-performance micro LED is located therein.

[0079] Additionally, as shown in FIG. 6, the first region may be formed such that the anode electrode and cathode electrode of some of the micro LEDs (21a) and the anode electrode and cathode electrode of the remaining micro LEDs (21b) are arranged opposite to each other. In this way, when the electrodes of the micro LEDs (21a, 21b) are arranged at 0 degrees (°) and 180 degrees (°), respectively, the second substrate (30) may be set such that both the anode electrode pad and the cathode electrode pad are in the same direction (e.g., 0 degrees (°)).

[0080] In FIG. 7, the micro LEDs transferred to the second substrate (30) may consist of three micro LEDs of red (R), green (G), and blue (B) forming a single pixel. Accordingly, the anode electrode pads and cathode electrode pads arranged on the second substrate (30) may be arranged adjacently in units of three pairs, and other pixels arranged around a single pixel may be arranged at a constant distance from the single pixel.

[0081] In one embodiment, the laser light source (60) may lift off the multiple micro LEDs (21) by irradiating a laser beam toward the rear surface of the first substrate (20) where the multiple micro LEDs (21) are not formed. For example, heat from the laser beam output from the laser light source (60) may be transferred to an adhesive layer (22) disposed between the micro LEDs (21) and the first substrate (20). As the adhesive strength of the adhesive layer (22) is reduced by the heat, the micro LEDs (21) may be separated from the first substrate (20) and transferred to a transfer area on the second substrate (30).

[0082] The micro LED (21) transferred to the second substrate (30) can have its anode electrode and cathode electrode physically and electrically connected to the anode electrode pad and cathode electrode pad of the second substrate (30). In this case, the anode electrode pad and cathode electrode pad of the second substrate (30) can be connected to the anode electrode and cathode electrode of the micro LED (21) as they are deformed from a solid state to a molten state by an irradiated laser beam.

[0083] In one embodiment, the micro LED transfer system of the present 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 the micro LED (21) to the second substrate (30). At least one of the first transfer device (1) and the second transfer device (2) may transfer the micro LED (21) to the second substrate (30) of an irregular shape. For example, the second substrate (30) on which the micro LED (21) of the present disclosure is transferred may be an irregular shape substrate.

[0084] Hereinafter, with reference to FIGS. 8 to 15, a method of transferring a micro LED to an irregular target substrate of a micro LED transfer system according to embodiments of the present disclosure will be described.

[0085] FIG. 8 illustrates the sequence of micro LED transfer operations of a first transfer device (1) according to one embodiment, FIG. 9 illustrates a mask unit (50) including a curve portion according to one embodiment, and FIG. 10 illustrates a mask unit (50) that moves and rotates by the control of a processor according to one embodiment.

[0086] In one embodiment, the first transfer device (1) may include a first laser light source unit (60) that irradiates a laser beam onto a first substrate (20) on which the micro LED (21) is placed, a mask unit (50) disposed between the first substrate (20) and the first laser light source unit (60) and selectively opens and closes 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).

[0087] Referring to FIG. 8, the first transfer device (1) can form an irregular laser beam (operation 810) and transfer a micro LED (21) to a second substrate (30) by moving and rotating a mask unit (50) that includes a curved portion (operation 820).

[0088] According to one example, in operation 810, the first transfer device (1) can form an irregular laser beam by moving and rotating a mask unit (50) that includes a curved portion. As shown in FIG. 9, the mask unit (50a) may include a curved portion having a predetermined curvature. For example, the mask unit (50a) may have a quadrant shape that includes the curved portion. However, the shape of the mask unit (50) of the present disclosure is not limited thereto, and the shape of the mask unit (50) may include various shapes that include a curved portion, such as a semi-circle shape or an oval shape.

[0089] 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 an 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).

[0090] The first transfer device (1) can form an irregular laser beam by passing a laser beam through a plurality of openings (S) of a moved and rotated mask unit (50). As shown in FIG. 10, the first transfer device (1) can rotate the mask unit (50a) 90 degrees (R1) clockwise, rotate the mask unit (50a) 90 degrees (R2) counterclockwise, or rotate the mask unit (50a) 180 degrees (R3) clockwise or counterclockwise. For example, the first transfer device (1) can form a circle-shaped laser beam by moving and rotating a quarter-circle shaped mask unit (50a).

[0091] According to one example, in operation 820, the first transfer device (1) can transfer a micro LED (21) to the second substrate (30). For example, when the first transfer device (1) moves and rotates the mask unit (50) to inject an irregular laser beam onto the first substrate (20), each micro LED (21) of the first substrate (20) located at a position corresponding to the openings of the mask unit (50) can be separated from the bottom surface of the first substrate (20) by the laser beam and transferred to the top surface of the second substrate (30). At this time, the anode electrode and the cathode electrode of each micro LED (21) can be physically and electrically connected to the anode electrode pad and the cathode electrode pad of the second substrate (30), respectively, due to the high heat of the laser beam.

[0092] In this way, the micro LED transfer system and the micro LED transfer method using the same of the present disclosure can transfer a micro LED (21) onto an irregular target substrate by moving and rotating a mask unit (50) including a curved portion. Accordingly, the micro LED transfer system and the micro LED transfer method using the same of the present disclosure can efficiently transfer a micro LED (21) onto an irregular target substrate applicable to display devices having various shapes.

[0093] FIG. 11 illustrates the sequence of micro LED transfer operations of a first transfer device (1) according to one embodiment, and FIG. 12 illustrates a laser beam passing sequentially through a first mask and a second mask.

[0094] In one embodiment, the first transfer device (1) may include a first laser light source unit (60) that irradiates a laser beam onto a first substrate (20) on which the micro LED (21) is placed, a mask unit (50) disposed between the first substrate (20) and the first laser light source unit (60) and selectively opens and closes 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).

[0095] Referring to FIG. 11, the first transfer device (1) can form an irregular laser beam using a first mask (operation 1110), inject the laser beam onto a first substrate (20) using a second mask (operation 1120), and transfer a micro LED (21) onto a second substrate (30) (operation 1130).

[0096] According to one example, in operation 1110, the first transfer device (1) can form an irregular laser beam using a first mask. 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).

[0097] Referring to FIG. 12, the first mask may be positioned above the second mask. For example, the first mask may be a blind mask. The first mask may include a forming opening for forming a laser beam (Z1) incident from a laser light source (60) into a predetermined shape. For example, the first mask may include a forming opening having at least one shape among a square, a triangle, a circle, a semicircle, and a quarter circle.

[0098] According to an embodiment, the first transfer device (1) can form an irregular laser beam (Z2) by moving and rotating the first mask. For example, the first mask can be moved and rotated by a transfer unit (10) to form the laser beam (Z1) into various shapes according to a combination of different shaped molding openings. For example, the first transfer device (1) can use the first mask to form the laser beam (Z1) into a laser beam (Z2) of various shapes including a circle, a semicircle, a quarter circle, and a curved section.

[0099] According to one example, in operation 1120, the first transfer device (1) can inject a laser beam onto the first substrate (20) using a second mask. For example, the first transfer device (1) can inject a formed laser beam (Z3) onto a micro LED (21) of the first substrate (20) located at a position corresponding to the openings by passing the formed laser beam (Z2) through the first mask through the open openings of the second mask.

[0100] According to one example, in operation 1130, the first transfer device (1) can transfer a micro LED (21) to the second substrate (30). For example, when the first transfer device (1) injects a laser beam formed through the first mask and the second mask onto the first substrate (20), the micro LED (21) corresponding to the formed laser beam on the first substrate (20) can be separated from the bottom surface of the first substrate (20) by the laser beam and transferred to the top surface of the second substrate (30). At this time, the anode electrode and the cathode electrode of each micro LED (21) can be physically and electrically connected to the anode electrode pad and the cathode electrode pad of the second substrate (30), respectively, due to the high heat of the laser beam.

[0101] In this way, the micro LED transfer system and the micro LED transfer method using the same of the present disclosure can transfer a micro LED (21) onto an irregular target substrate by forming a laser beam with a first mask and scanning the laser beam onto a wafer with a second mask. Accordingly, the micro LED transfer system and the micro LED transfer method using the same of the present disclosure can efficiently transfer a micro LED (21) onto an irregular target substrate applicable to display devices having various shapes.

[0102] FIG. 13 illustrates the sequence of micro LED transfer operations of a first transfer device (1) and a second transfer device (2) according to one embodiment, FIG. 14 illustrates a first region and a second region of a second substrate (30), and FIG. 15 illustrates a second transfer device (2) of a micro LED transfer system according to one embodiment.

[0103] Referring to FIG. 13, the micro LED transfer system can transfer a micro LED (21) to a first area of ​​a second substrate (30) using a first transfer device (1) (operation 1310) and transfer a micro LED (21) to a second area of ​​a second substrate (30) using a second transfer device (2) (operation 1310).

[0104] In one embodiment, the first transfer device (1) can transfer the micro LED (21) to the second substrate (30) in a multi-transfer manner. Additionally, the second transfer device (2) can transfer the micro LED (21) to the second substrate (30) in a one-by-one transfer manner.

[0105] As shown in FIG. 14, the second substrate (30) may be an irregular (e.g., circular) substrate. The transfer area of ​​the second substrate (30) may be divided into a first area (31) and a second area (32). For example, the second substrate (30) may include a first area (31) that includes a non-curved area and a second area (32) that includes a curved area. The first area (31) is a transfer area formed on the inner side of the second substrate (30) and may be an area of ​​a standardized shape (e.g., a rectangle). The second area (32) is a transfer area formed on the edge of the second substrate (30) and may be an irregular area (e.g., a shape including a curve). For example, the second area (32) may be an area surrounding the first area (31).

[0106] According to one example, in operation 1310, the micro LED transfer system can transfer the micro LED (21) to a first area of ​​the second substrate (30) using the first transfer device (1).

[0107] The first transfer device (1) may include a first laser light source unit (60) that irradiates a laser beam onto a first substrate (20) on which the micro LED (21) is placed, a mask unit (50) disposed between the first substrate (20) and the first laser light source unit (60) and selectively opens and closes 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).

[0108] The first transfer device (1) can rapidly transfer micro LEDs (21) to a first region (31) of a shaped form (e.g., a rectangle) using a multi-transfer method. For example, when the first laser light source (60) injects a laser beam into the first substrate (20) through the mask unit (50), each micro LED (21) of the first substrate (20) located at a position corresponding to the openings of the mask unit (50) can be separated from the bottom surface of the first substrate (20) by the laser beam and transferred to the first region (31) of the second substrate (30).

[0109] According to one example, in operation 1320, the micro LED transfer system can transfer a micro LED (21) to a second region (32) of a second substrate (30) using a second transfer device (2). For example, the second transfer device (2) can sequentially transfer a micro LED (21) to a second region (32) of the second substrate (30) after the first transfer device (1) has transferred a micro LED (21) to a first region (31) of the second substrate (30).

[0110] The second transfer device (2) may include a second laser light source (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 in the direction of the micro LED (21) transferred to the second substrate (30).

[0111] The second transfer device (2) can precisely transfer the micro LED (21) to a second region (32) of irregular shape (e.g., a shape including a curved section) in a one-by-one transfer manner. For example, as shown in FIG. 15, the second laser light source unit (60) can output a laser beam to the path changing unit (13). The path changing unit (13) can rapidly change the path of the laser beam (Z) emitted from the second laser light source unit (60) so that the laser beam, which is a point light source, can be changed to be close to a surface light source or a line light source.

[0112] Specifically, the path changing unit (13) can change the laser beam (Z) output from the second laser light source unit (60) in units of ms, μ (micro sec), and ns (nano sec) and irradiate the laser beam (Z) to a predetermined location on the first substrate (20) on which the micro LED (21) is placed. Here, since the laser beam (Z) changed by the path changing unit (13) is irradiated onto the first substrate (20) in units of ms, μ (micro sec), and ns (nano sec), the micro LED (21) can be separated from the first substrate (20) and simultaneously transferred to the second region (32) of the second substrate (30).

[0113] For example, the path changing unit (13) may include a galvano mirror. The galvano mirror may be a device capable of rapidly changing the path of a light source by rapidly rotating a mirror that reflects the light source. As illustrated in FIG. 15, the second processor can change the path of the laser beam (Z) so that the micro LED (21) is transferred to the second area (32) by controlling the path changing unit (13) in a preset rotation direction (R1, R2) based on position information of the second area (32) to be transferred. For example, the laser beam (Z) is sequentially reflected by the galvano mirror 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 area (32) of the second substrate (30).

[0114] In this way, the micro LED transfer system and the micro LED transfer method using the same disclosed in the present disclosure can transfer a micro LED (21) onto an irregularly shaped target substrate by transferring a micro LED (21) onto a non-curved portion of a target substrate using a first transfer device (1) of a multi-transfer method and transferring a micro LED (21) onto a curved portion of a target substrate using a second transfer device (2) of a 1-by-1 transfer method. Accordingly, the micro LED transfer system and the micro LED transfer method using the same disclosed in the present disclosure can efficiently transfer a micro LED (21) onto an irregularly shaped target substrate applicable to display devices having various shapes.

[0115] The various embodiments of this document and the terms used therein are not intended to limit the technical features described in this document to specific embodiments, and should be understood to include various modifications, equivalents, or substitutions of said embodiments. For example, a component expressed in the singular should be understood as a concept including a plural component unless the context clearly implies only the singular. It should be understood that the term "and / or" as used in this document encompasses any possible combination of one or more of the listed items. Terms such as "comprising," "having," and "consisting of" used in this disclosure are intended merely to indicate the existence of the features, components, parts, or combinations thereof described in this disclosure, and the use of such terms is not intended to exclude the existence or addition of one or more other features, components, parts, or combinations thereof. In this document, each of the 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” may include any one of the items listed together in the corresponding phrase, or all possible combinations thereof. Terms such as “first,” “second,” or “first” or “second” may be used simply to distinguish a component from another component and do not limit the components in any other aspect (e.g., importance or order).

[0116] The terms “part” or “module” as used in the various embodiments of this document may include a unit implemented in hardware, software, or firmware, and may be used interchangeably with terms such as logic, logic block, component, or circuit, for example. The “part” or “module” may be a component formed integrally, or a minimum unit of said component or a part thereof that performs one or more functions. For example, according to one embodiment, the “part” or “module” may be implemented in the form of an application-specific integrated circuit (ASIC).

[0117] In the various embodiments of this document, the term “in the case of” as used may be interpreted, depending on the context, to mean “when,” “at the time of,” or “in response to a decision,” or “in response to a detection.” Similarly, “in the case where it is determined,” or “in the case where it is detected,” may be interpreted, depending on the context, to mean “at the time of determination,” or “in response to a decision,” or “at the time of detection,” or “in response to a detection.”

[0118] The program executed by the transcription device described in this document may be implemented by hardware components, software components, and / or a combination of hardware and software components. The program may be executed by any system capable of executing computer-readable instructions.

[0119] Software may include computer programs, code, instructions, or a combination of one or more of these, and may configure a processing unit to operate as desired or command the processing unit independently or collectively. Software may be implemented as a computer program containing instructions stored on computer-readable storage media. Examples of computer-readable storage media include magnetic storage media (e.g., ROM (Read-Only Memory), RAM (Random-Access Memory), floppy disks, hard disks, etc.) and optical reading media (e.g., CD-ROMs, DVDs (Digital Versatile Discs)). Computer-readable storage media may be distributed across networked computer systems, allowing computer-readable code to be stored and executed in a distributed manner. Computer programs may be distributed online (e.g., download or upload) through an application store (e.g., Play Store™) or directly between two user devices (e.g., smartphones). In the case of online distribution, at least a portion of the computer program product may be temporarily stored or temporarily created on a device-readable storage medium, such as the memory of a manufacturer's server, an application store's server, or a relay server.

[0120] According to various embodiments, each component (e.g., module or program) of the components described above may include a singular or multiple entities, and some of the multiple entities may be separated and placed in other components. According to various embodiments, one or more of the components or operations of the aforementioned components may be omitted, or one or more other components or operations may be added. Generally or additionally, multiple components (e.g., module or program) may be integrated into a single component. In this case, the integrated component may perform one or more functions of each of the multiple components in the same or similar manner as those performed by the corresponding component among the multiple components prior to integration. According to various embodiments, operations performed by the module, program, or other components may be executed sequentially, in parallel, iteratively, or heuristically, or one or more of the operations may be executed in a different order, omitted, or one or more other operations may be added.

Claims

1. In a micro LED (light emitting diode) transfer system, It includes at least one of a first transfer device for transferring a micro LED to a second substrate and a second transfer device for transferring the micro LED to the second substrate. The above-mentioned first transfer device is, A first laser light source unit that irradiates a laser beam onto a first substrate on which the above-mentioned micro LED is arranged; A mask unit disposed between the first substrate and the first laser light source and selectively opening and closing at least one opening; and It includes a first processor that controls the mask unit to open and close the opening corresponding to the micro LED transferred to the second substrate, and At least one of the first transfer device or the second transfer device is, Transferring the micro LED to the second substrate having an irregular shape, Micro LED transfer system.

2. In Paragraph 1, The above mask unit is, It includes a curved section having a predetermined curvature, and The above-mentioned first processor is, By moving and rotating the above mask unit, an irregular laser beam is formed. Micro LED transfer system.

3. In Paragraph 2, The above mask unit is, Having a quadrant shape including the above curved portion, The above-mentioned first processor is, By moving and rotating the above mask unit, a circular laser beam is formed. Micro LED transfer system.

4. In any one of paragraphs 1 through 3, The above mask unit is, A first mask for shaping the laser beam; and A second mask comprising scanning the laser beam onto the first substrate, Micro LED transfer system.

5. In Paragraph 4, The first mask above is, A molded opening having at least one shape among a square, triangle, circle, semicircle, or quarter circle, Micro LED transfer system.

6. In Paragraph 4, The above-mentioned first processor is, By moving and rotating the first mask above, an irregular laser beam is formed. Micro LED transfer system.

7. In any one of paragraphs 1 through 6, The above-mentioned first transfer device is, The micro LED is transferred to the second substrate using a multi-transfer method, and The above second transfer device is, Transferring the micro LED to the second substrate using a one-by-one transfer method, Micro LED transfer system.

8. In any one of paragraphs 1 through 7, The above second transfer device is, A second laser light source unit that outputs a laser beam; A path changing unit for changing the path of the above laser beam; and A second processor comprising a path changing unit that controls the path changing unit to change the path of the laser beam in the direction of the micro LED transferred to the second substrate, Micro LED transfer system.

9. In Paragraph 8, The above-mentioned first transfer device is, The micro LED is transferred to the first region of the second substrate, and The above second transfer device is, Transferring the micro LED to the second region of the second substrate, Micro LED transfer system.

10. In Paragraph 9, The first region above includes a non-curved region of the second substrate, and The second region above includes a curved region of the second substrate, Micro LED transfer system.

11. In a micro LED transfer method, The operation of transferring a micro LED to a second substrate using a first transfer device; and The operation of transferring the micro LED to the second substrate using a second transfer device is included. The operation of transferring the micro LED to the second substrate using the first transfer device is, An operation of irradiating a laser beam onto a first substrate on which the micro LED is arranged using a first laser light source; An operation of selectively opening and closing at least one opening using a mask unit disposed between the first substrate and the first laser light source unit; and The method includes controlling the mask unit to open and close the opening corresponding to the micro LED transferred to the second substrate using a first processor, and At least one of the first transfer device and the second transfer device is, Transferring the micro LED to the second substrate having an irregular shape, Micro LED transfer method.

12. In Paragraph 11, The above mask unit is, It includes a curved section having a predetermined curvature, and The operation of controlling the mask unit using the first processor is, By moving and rotating the above mask unit, an irregular laser beam is formed. Micro LED transfer method.

13. In Paragraph 12, The above mask unit is, Having a quadrant shape including the above curved portion, The operation of controlling the mask unit using the first processor is, By moving and rotating the above mask unit, a circular laser beam is formed. Micro LED transfer method.

14. In any one of paragraphs 11 through 13, The operation of selectively opening and closing at least one opening using the above mask unit is, The operation of shaping the laser beam using a first mask; and The operation of scanning the laser beam onto the first substrate using a second mask, Micro LED transfer method.

15. In Paragraph 14, The first mask above is, A molded opening having at least one shape among a square, triangle, circle, semicircle, and quarter circle, Micro LED transfer method.

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