LED transfer method and display module manufactured using the same

Abstract

A light emitting diode (LED) transfer method is proposed. The LED transfer method includes: disposing a transfer substrate between a target substrate and a laser oscillator, wherein a plurality of LEDs of different colors are sequentially arranged on the transfer substrate in at least one row or at least one column; and transferring the plurality of LEDs from the transfer substrate to a predetermined point of the target substrate simultaneously by irradiating a laser beam from the laser oscillator to the target substrate.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a light emitting diode (LED) transfer method and a display module including a plurality of LEDs manufactured by the method. BACKGROUND

[0002] A micro light emitting diode (micro LED, mLED, or μLED) display panel is a flat display panel including a plurality of inorganic LEDs each of which is smaller than 100 micrometers.

[0003] Compared to a liquid crystal panel requiring a backlight, a micro LED display panel provides improved contrast, response time, and energy efficiency.

[0004] Although both organic LEDs (OLEDs) and micro LEDs have high energy efficiency, micro LEDs are brighter, have higher luminous efficiency, and have longer lifespan compared to OLEDs.

[0005] An LED is an ultra-small inorganic light emitting material that emits light without a color filter and a backlight. A plurality of LEDs are manufactured by growing in a chip form on a wafer (growth substrate) through an epitaxial process. The LEDs manufactured in this way can be transferred to a target substrate to constitute a display module.

[0006] However, the plurality of LEDs grown on the wafer have differences in performance (e.g., color, brightness, etc.) between regions due to manufacturing tolerances, technical limitations, etc. in the manufacturing process. That is, LEDs formed in regions far from a specific region of the wafer (e.g., a central portion of the wafer) can exhibit reduced performance.

[0007] As described above, the LEDs can be transferred to the target substrate in an arrangement state in which the performance of the LEDs in each region of the wafer is different. Accordingly, the plurality of LEDs provided on the target substrate have different performance between regions. Due to these performance differences, the display module manufactured using the target substrate has a problem in that brightness or color is not uniform across the entire region.

[0008] Red LEDs emitting red (R) light, green LEDs emitting green (G) light, and blue LEDs emitting blue (B) light are respectively formed on different wafers. Accordingly, the LEDs can be sequentially transferred to the target substrate of each color from the wafer on which only the red LEDs are formed, the wafer on which only the green LEDs are formed, and the wafer on which only the blue LEDs are formed. However, because a process of first moving each wafer to the transfer position of each color to perform the transfer and then replacing each wafer with another wafer needs to be performed, there is a problem in that the LED transfer time is increased. As a result, the total manufacturing time of the display module is increased. SUMMARY

[0009] TECHNICAL SOLUTION

[0010] According to an aspect of the disclosure, a light emitting diode (LED) transfer method includes: disposing a transfer substrate between a target substrate and a laser oscillator, wherein a plurality of LEDs of different colors are sequentially arranged on the transfer substrate in at least one row or at least one column; and simultaneously transferring the plurality of LEDs from the transfer substrate to a predetermined point of the target substrate by irradiating a laser beam from the laser oscillator toward the target substrate. The plurality of LEDs are formed in a group and simultaneously transferred onto the target substrate.

[0011] A plurality of groups including the group are simultaneously transferred onto the target substrate at predetermined intervals.

[0012] The group includes a red LED, a green LED, and a blue LED.

[0013] The group further includes a white LED.

[0014] The method includes: moving the transfer substrate by a first movement distance; moving the target substrate by a second movement distance different from the first movement distance; and simultaneously transferring other plurality of LEDs of different colors from the transfer substrate to the target substrate.

[0015] The method includes bonding the plurality of LEDs to the target substrate by pressing the plurality of LEDs using a pressing member.

[0016] The pressing member is configured to press the plurality of LEDs using a buffer layer formed on a surface facing the plurality of LEDs.

[0017] The method includes bonding the relay substrate by pressing the relay substrate toward the target substrate.

[0018] The method includes bonding the plurality of LEDs to the target substrate using a thermal bonding method.

[0019] The thermal bonding method includes heating the target substrate with a heater, or heating the target substrate with an infrared laser.

[0020] According to an aspect of the disclosure, a display module includes: a glass substrate; and a plurality of light emitting diodes (LEDs) of different colors. The display module is manufactured by: disposing a transfer substrate between the glass substrate and a laser oscillator, wherein the plurality of LEDs are sequentially arranged on the transfer substrate in at least one row or at least one column; and simultaneously transferring the plurality of LEDs from the transfer substrate to a predetermined point of the glass substrate by irradiating a laser beam from the laser oscillator toward the target substrate.

[0021] The plurality of LEDs are formed in a group and simultaneously transferred onto the target substrate.

[0022] A plurality of groups including the group are simultaneously transferred onto the glass substrate at predetermined intervals.

[0023] The group includes a red LED, a green LED, and a blue LED.

[0024] The group also includes at least one additional LED different in color from the red LED, the green LED, and the blue LED.

[0025] The additional LED is a white LED.

[0026] The red LED, the green LED, and the blue LED are sequentially arranged in a row or a column.

[0027] The red LED, the green LED, the blue LED, and the white LED are sequentially arranged in a row or a column.

[0028] According to an aspect of the disclosure, a non-transitory computer readable medium includes a program that performs a light emitting diode (LED) transfer method. The LED transfer method includes: disposing a transfer substrate between a target substrate and a laser oscillator, wherein a plurality of LEDs of different colors are sequentially arranged in at least one row or at least one column on the transfer substrate; and simultaneously transferring the plurality of LEDs from the transfer substrate to a predetermined point of the target substrate by irradiating a laser beam from the laser oscillator toward the target substrate. BRIEF DESCRIPTION OF DRAWINGS

[0029] The above and other aspects, features, and advantages of the disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0030] Figure 1 is a block diagram schematically illustrating an LED transfer apparatus according to an embodiment;

[0031] Figure 2 is a flowchart illustrating a process of manufacturing an LED transfer substrate according to an embodiment;

[0032] Figures 3 to 6 is a diagram sequentially illustrating a process of transferring a plurality of LEDs from a plurality of growth substrates to a temporary substrate according to an embodiment;

[0033] Figures 7 to 9 is a diagram sequentially illustrating a process of transferring a plurality of LEDs from a temporary substrate to a relay substrate according to an embodiment;

[0034] Figure 10 is a flowchart illustrating a process of transferring a plurality of LEDs from a relay substrate to a target substrate according to an embodiment;

[0035] Figures 11 to 16 is a diagram sequentially illustrating a process of transferring a plurality of LEDs from a relay substrate to a target substrate according to an embodiment;

[0036] Figure 17 is a flowchart illustrating a transfer method according to an embodiment;

[0037] Figures 18A to 18D It is shown in sequence according to Figure 17 The illustrated embodiment shows the process of transferring multiple LEDs from a relay substrate to a target substrate.

[0038] Figure 19 This is a flowchart illustrating a transfer method according to an embodiment;

[0039] Figures 20A to 20D It is shown in sequence according to Figure 19 A diagram illustrating the process of transferring multiple LEDs from a relay substrate to a target substrate in the embodiment shown.

[0040] Figure 21 This is a flowchart illustrating a transfer method according to an embodiment;

[0041] Figures 22A to 22D It is shown in sequence according to Figure 21 A diagram illustrating the process of transferring multiple LEDs from a relay substrate to a target substrate in the embodiment shown.

[0042] Figure 23 This is a flowchart illustrating a transfer method according to an embodiment; and

[0043] Figures 24A to 24D It is shown in sequence according to Figure 23 The diagram illustrates the process of transferring multiple LEDs from a relay substrate to a target substrate using the transfer method of the illustrated embodiment.

[0044] Best practice Detailed Implementation

[0045] To fully describe the configuration and effects of this disclosure, embodiments of this disclosure will be described with reference to the accompanying drawings. However, this disclosure is not limited to the embodiments disclosed below and can be implemented in various forms and with various modifications. The description of embodiments is provided to make this disclosure complete and to give those skilled in the art a full understanding of its scope. In the drawings, for ease of description, the dimensions of components are shown as different from actual dimensions, and the scale of each component may be exaggerated or reduced.

[0046] Various components may be described using terms such as "first" and "second," but components should not be limited by these terms. These terms may be used for the purpose of distinguishing one component from other components. For example, without departing from the scope of this disclosure, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component.

[0047] The singular expression of a term includes the plural expression of the term unless the context clearly dictates otherwise. Terms such as "include", "have" and the like can mean the presence of the listed features, numbers, steps, operations, components, parts, or combinations thereof, but do not exclude the presence of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0048] Expressions such as "at least one of a, b, and c" after a list of elements such as "a, b, and c" modify the entire list of elements and do not modify the individual elements of the list. For example, the expression "at least one of a, b, and c" is understood as including only a, only b, only c, both a and b, both a and c, both b and c, all of a, b, and c, or any variations of the above examples.

[0049] Unless otherwise defined, the terms used to describe embodiments of the disclosure can be interpreted in accordance with the meanings commonly known to those skilled in the art.

[0050] A display module manufactured according to embodiments of the disclosure can include a substrate on one surface of which a thin film transistor (TFT) layer is formed, a plurality of LEDs arranged on the TFT layer, and a wiring electric connection circuit arranged on the back surface of the substrate. Here, the substrate can correspond to a target substrate described later, which can be any one of a glass substrate, a flexible substrate, and a plastic substrate, and can be referred to as a "backplane".

[0051] A display module according to embodiments of the disclosure can include a back substrate electrically connected to the back surface of the substrate through a flexible printed circuit (FPC). Here, the back substrate can be formed in a thin film form or a thin glass form having a thickness of several tens of micrometers (μm) (e.g., 50 μm or less). In the case where the back substrate is formed in a thin film form, the back substrate can be formed of a plastic material, such as any one of polyimide (PI), polyethylene terephthalate (PET), polyether sulfone (PES), polyethylene naphthalate (PEN), and polycarbonate (PC).

[0052] The substrate according to the embodiment can have a side wire formed on the edge portion, and the side wire can electrically connect the first connection pad formed on the edge portion of the front surface of the substrate and the second connection pad formed on the rear surface. To this end, the side wire can be formed along the front surface, the side end surface, and the rear surface of the substrate, and can have one end electrically connected to the first connection pad and the other end electrically connected to the second connection pad. At this time, since the side wire is partially formed on the side end surface of the substrate, the side wire can protrude from the side end surface of the TFT substrate by the thickness of the side wire. In this case, the back substrate can be electrically connected to the second connection pad through the FPC. The driver integrated circuit (IC) mounted on the rear surface of the TFT substrate can be directly connected to the second connection pad or indirectly connected to the second connection pad through a separate wire.

[0053] Further, the display module according to the embodiment can be applied to wearable devices, portable devices, handheld devices, and electronic products, or electronic devices having a plurality of displays in a single unit, and can be applied to small display devices such as monitors of personal computers and televisions (TVs) and large display devices such as digital signage and electronic displays through a plurality of assembly structures.

[0054] The LED according to the embodiment can be composed of an inorganic light emitting material, and can be a semiconductor chip capable of self-emitting light when supplied with power.

[0055] Further, the LED has the characteristics of fast reaction speed, low power, and high brightness, and thus can become a micro LED, which is an emitting element of a next-generation display, attracting much attention. Such a micro LED has higher electro-optical conversion efficiency than a conventional liquid crystal display (LCD) or an organic light emitting diode (OLED). That is, the micro LED has higher "brightness per watt" than the conventional LCD or OLED display. Accordingly, the micro LED can emit the same brightness while consuming half the power of the conventional LED (for example, an LED having an area greater than 100 µm x 100 µm) or OLED. Further, the micro LED can achieve high resolution, excellent color, contrast, and brightness, thereby accurately expressing a larger range of colors, and can achieve a clear screen even in an outdoor environment where sunlight directly hits. Further, since the micro LED has burn resistance and low heat generation, a longer product life without deformation can be provided.

[0056] Further, according to an embodiment, when a plurality of LEDs of different colors (e.g., red, green, and blue LEDs) are first transferred to a relay substrate at the same time, and then the plurality of LEDs are secondarily transferred from the relay substrate to a target substrate for each unit (e.g., each of R, G, and B units), various transfer methods (e.g., a laser transfer method, a stamp transfer method, a roller transfer method, and an electrostatic transfer method) can be applied. Hereinafter, the laser transfer method among the transfer methods described in the disclosure will be described as an example.

[0057] The display module according to an embodiment can be applied as a single unit to a wearable device, a portable device, a handheld device, etc., and can be applied to electronic products having various displays. Further, the display module can be matrix type, and can be applied to display devices such as a personal computer display, a high-resolution television, a signboard, an electronic display, etc. through a plurality of assembly structures.

[0058] An embodiment can provide an LED transfer method capable of significantly reducing a processing time by transferring LEDs of different colors to a target substrate at the same time.

[0059] An embodiment can also provide a display module including LEDs capable of improving uniformity of performance by uniformly arranging a plurality of LEDs having different performances on a target substrate.

[0060] Hereinafter, a description will be given of an LED transfer apparatus according to an embodiment. Figure 1 The structure of an LED transfer apparatus according to an embodiment will be described.

[0061] Figure 1 is a block diagram schematically illustrating an LED transfer apparatus according to an embodiment.

[0062] Referring to Figure 1 , the LED transfer apparatus can include a transfer assembly 10 for transferring a plurality of red, green, and blue LEDs arranged in a predetermined structure on a relay substrate to a target substrate, a stage 40 disposed adjacent to the transfer assembly 10 to move the target substrate in X, Y, and Z axis directions, a memory 60 storing characteristic information of each of the plurality of LEDs, and a processor 50 for controlling the transfer assembly 10 and the stage 40 to determine positions at which the plurality of LEDs are respectively placed on the relay substrate based on the stored characteristic information, and to transfer the plurality of LEDs to the determined placement positions.

[0063] The transfer assembly 10 can transfer predetermined red, green, and blue LEDs from the relay substrate on which the plurality of red, green, and blue LEDs are arranged to the target substrate by a laser lift-off (LLO) method or a pick-and-place method.

[0064] To perform a transfer process using the LLO method, the transfer assembly 10 can include a laser oscillator 11 (as shown in Figure 12 ) for emitting a laser beam to the relay substrate 30 (as shown in Figure 12 ), a mask 13 for limiting an irradiation position (or range) of the laser beam so that a predetermined LED is selectively irradiated with the laser beam irradiated from the laser oscillator, and a stage for the relay substrate 30, which can move the relay substrate 30 in X, Y, and Z axis directions and rotate the relay substrate 30 about the Z axis.

[0065] In this case, the mask 13 is disposed between the laser oscillator 11 and the relay substrate 30. The mask 13 can include a plurality of openings 13a (see Figure 12 ) patterned in consideration of positions of a plurality of LEDs arranged on the relay substrate 30. Although the mask 13 shown in Figure 12 is shown as being formed with only one opening 13a, the mask 13 has a plurality of openings so that a plurality of predetermined red, green, and blue LEDs can be simultaneously transferred from the relay substrate 30, as shown in Figure 15 .

[0066] Each of the plurality of openings 13a can include a shape capable of passing the laser beam to land the plurality of LEDs on the relay substrate 30.

[0067] In addition, in consideration of a pitch (P1, see Figure 11 ) between the plurality of LEDs arranged on the relay substrate 30 and a pitch (P2, see Figure 15 ) between the plurality of LEDs transferred together on the target substrate 70, the plurality of openings 13a can include a set formation position.

[0068] To perform a transfer process using a pick-and-place method, the transfer assembly 10 can include a picker for picking up a predetermined LED from the relay substrate and placing the predetermined LED on the target substrate, and a stage for the relay substrate, which can move the relay substrate in X, Y, and Z axis directions and rotate the relay substrate about the Z axis. In this case, the picker can pick up and transfer the plurality of LEDs using various methods, such as an adhesive method, a vacuum method, an electrostatic method, a hybrid method, etc.

[0069] The stage 40 can detachably clamp the target substrate 70 (as shown in Figure 11 ) to an upper surface of the stage 40 and can move in X, Y, and Z axis directions and rotate about the Z axis while clamping the target substrate 70.

[0070] According to the embodiments, the LED substrate refers to a substrate manufactured for transferring an LED onto a target substrate 70. Therefore, in this disclosure, the LED substrate may refer to a "transfer wafer" or "relay substrate" manufactured in a state capable of transferring an LED onto the target substrate 70.

[0071] LEDs for each emission color (R, G, and B) can be formed on the first to third growth substrates 20a, 20b, and 20c. That is, the first growth substrate 20a can be a substrate on which only red LEDs are grown, the second growth substrate 20b can be a substrate on which only green LEDs are grown, and the third growth substrate 20c can be a substrate on which only green LEDs are grown. Figure 3 , Figure 5 and Figure 6 The first to third growth substrates 20a, 20b and 20c are shown respectively.

[0072] Each of the growth substrates 20a, 20b, and 20c can be a transparent substrate made of sapphire, silicon, or transparent glass, and can be used in a process employing the LLO method. In this case, the transparent glass can be formed of a material applicable to epitaxial growth to form a chip stack, such as metal-organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE).

[0073] In addition, each of the growth substrates 20a, 20b and 20c forms a buffer layer, which is made of a material capable of mitigating strain caused by the difference in lattice constant and coefficient of thermal expansion between the GaN layer and the growth substrate on its upper surface.

[0074] The buffer layer can be composed of GaN, AlN, AlGaN or SiNx as high heat-resistant materials, so that GaN layer deposition can be achieved through MOCVD or MBE processes.

[0075] via temporary substrate 25 (e.g.) Figure 3 As shown, multiple LEDs formed by epitaxial growth on each of growth substrates 20a, 20b, and 20c will be transmitted to relay substrate 30 (e.g., ...). Figure 9 (As shown).

[0076] Temporary substrate 25 can be a transparent substrate made of sapphire, silicon, or transparent glass, and can be used in processes applying the LLO method. Buffer layer 27 (e.g. Figure 3 (As shown) can be formed on temporary substrate 25 in a manner similar to that of growth substrate 20.

[0077] By considering the performance difference of each region of each of the first substrates 20a, 20b, and 20c, the red, green, and blue LEDs grown on the different first substrates 20a, 20b, and 20c by the epitaxial process can be arranged on the temporary substrate 25 based on the data map created for each of the first substrates 20a, 20b, and 20c. In this case, the plurality of red, green, and blue LEDs of each of the growth substrates 20a, 20b, and 20c can be transferred to the temporary substrate 25 in the form of at least one row or at least one column for each color. In the case where the plurality of LEDs are arranged in at least one row for each color, the spacing between the respective columns adjacent to each other can be equally set, and in the case where the plurality of LEDs are arranged in at least one column for each color, the spacing between the respective columns adjacent to each other can be equally set. In one embodiment, the plurality of LEDs are arranged in two rows for each color.

[0078] Thus, the plurality of LEDs arranged on the temporary substrate 25 are transferred to the relay substrate 30 for transfer.

[0079] The temporary substrate 25 can be formed to be larger in size than the growth substrate 20. Accordingly, the plurality of LEDs provided on one growth substrate 20 and the plurality of LEDs provided on a plurality of growth substrates 20 can be transferred to one temporary substrate 25 in the LLO method.

[0080] The relay substrate 30 can be formed in the same size as the temporary substrate 25. Accordingly, all of the red, green, and blue LEDs transferred from the plurality of growth substrates 20a, 20b, and 20c can be simultaneously transferred to the temporary substrate 25.

[0081] The plurality of LEDs transferred from the temporary substrate 25 to the relay substrate 30 are attached to the adhesive layer 33 (as shown in FIG. 3B) formed on the relay substrate 30. Figure 9 The adhesive layer 33 can be referred to as a "dynamic release layer" (DRL), and can be formed of a polyimide (PI) material to facilitate separation when transferred to the target substrate 70 (as shown in FIG. 3C) using the LLO method. Figure 11

[0082] The relay substrate 30 can be a transparent substrate made of sapphire, silicon, or transparent glass, and can be used in a process in which the LLO method is applied.

[0083] Among the plurality of red, blue, and green LEDs transferred to the relay substrate 30, predetermined red, blue, and green LEDs can be simultaneously transferred to the target substrate 70 using the LLO method.

[0084] ​In the LED transfer method according to the embodiment, since the operation of replacing the LED substrate of each color to transfer the LEDs from each wafer on which LEDs of each color are arranged to the target substrate can be omitted, the transfer process time can be significantly shortened.

[0085] In addition, since the relay substrate 30 is formed larger than each wafer, a plurality of LEDs can be simultaneously transferred to the target substrate 70. In contrast, in the case where the LEDs are transferred from each wafer to the target substrate 70, since there is a difference in size between the wafer and the target substrate, the transfer process is performed a plurality of times. As a result, it is likely that the target substrate including sensitive electronic elements such as a thin film transistor (TFT) is damaged. Therefore, in the case where a plurality of LEDs are transferred to the target substrate 70 using the relay substrate 30 according to the embodiment, the transfer speed and the transfer efficiency can be improved, and the transfer stability and reliability can be improved.

[0086] In addition, the relay substrate 30 can have a pattern for disposing a plurality of LEDs on the relay substrate 30. Here, the pattern can be a circuit 30 including a wire for supplying current to the plurality of LEDs transferred on the relay substrate.

[0087] Therefore, in the case where a plurality of LEDs are transferred from the temporary substrate 25 to the relay substrate 30, the operability and performance of the plurality of LEDs can be integrally checked on the relay substrate 30.

[0088] In this case, by removing the LED having poor performance or lower than a predetermined performance, and disposing a new LED at the position of the removed LED, the embodiment provides the ability to correct the plurality of LEDs transferred on the relay substrate 30.

[0089] The LED transfer apparatus 1 can include a memory 60 and a processor 50.

[0090] The memory 60 can be implemented by at least one of a flash type, a read only memory (ROM), a random access memory (RAM), a hard disk type, a multimedia card micro type, or a card type memory such as a secure digital (SD) or an extreme digital (XD) memory.

[0091] In addition, the memory 60 can be electrically connected to the processor 50 to transmit and receive signals and information to and from the processor 50. Therefore, the memory 60 can store characteristic information of a plurality of input or irradiated LEDs, and transmit the stored characteristic information to the processor 50.

[0092] The processor 50 controls the overall operation of the LED transfer apparatus 1. That is, the processor 50 can be electrically connected to the transfer assembly 10 and the stage 40 to control each component.

[0093] For example, the processor 50 can control the transfer assembly 10 and the stage 40 to transfer the plurality of LEDs from the growth substrate 20 to the temporary substrate 25, and to transfer the plurality of LEDs from the temporary substrate 25 to the relay substrate 30. In addition, the processor 50 can control the transfer assembly 10 and the stage 40 to transfer the plurality of LEDs arranged on the relay substrate 30 to the target substrate 70. The processor 50 can be a single processor configured to control the above-described components, or can be a plurality of processors that control the above-described components.

[0094] The processor 50 can include one or more of a central processing unit (CPU), a controller, an application processor (AP), a communication processor (CP), or an ARM processor.

[0095] In addition, the processor 50 can be electrically connected to the memory 60 to use the characteristic information of the plurality of LEDs stored in the memory 60.

[0096] Hereinafter, a process of manufacturing an LED substrate (relay substrate) according to an embodiment will be described with reference to Figures 2 to 16 The manufacturing process of the LED substrate (relay substrate) according to the embodiment will be described sequentially.

[0097] Figure 2 is a flowchart illustrating a process of manufacturing an LED transfer substrate (relay substrate) according to an embodiment, Figures 3 to 7 is a diagram illustrating a process of transferring a plurality of LEDs from a plurality of growth substrates to a temporary substrate according to an embodiment, and Figure 8 and Figure 9 is a diagram illustrating a process of transferring a plurality of LEDs from a temporary substrate to a relay substrate according to an embodiment.

[0098] Referring to Figure 2 , the characteristics of the plurality of LEDs respectively formed on each of the growth substrates 20a, 20b, and 20c are checked (operation S1). The processor 50 analyzes the brightness and the wavelength of each LED for each region of each of the growth substrates 20a, 20b, and 20c. The analysis result can be stored in the memory 60.

[0099] If the characteristic check is completed, when the plurality of red LEDs, green LEDs, and blue LEDs are arranged from each of the growth substrates 20a, 20b, and 20c to the temporary substrate 25 based on the analysis result, the processor 50 simulates a combination of each position for an optimal arrangement considering uniformity (operation S2).

[0100] If the optimal arrangement of the plurality of red LEDs, green LEDs, and blue LEDs to be arranged on the temporary substrate 25 is set through the simulation, the processor 50 forms a data map based on the optimal arrangement (operation S3). The data map can be stored in the memory 60.

[0101] Subsequently, the LEDs of each of the growth substrates 20a, 20b, and 20c are sequentially transferred to the temporary substrate 25 for each color based on the data map (operation S4).

[0102] Subsequently, the LEDs are transferred from the temporary substrate 25 to the relay substrate 30 (operation S5).

[0103] Reference Figure 3 The temporary substrate 25 is fixed to the stage 40, and the first growth substrate 20a on which a plurality of red LEDs are formed is disposed on the temporary substrate 25. In this case, the first growth substrate 20a is provided with the plurality of red LEDs facing the temporary substrate 25, and can be in contact with the temporary substrate 25.

[0104] The first growth substrate 20a can be fixed to the stage which is movable in the X-axis and Y-axis directions. In this case, the stage can move or stop the first growth substrate 20a to a desired position on the X-Y plane.

[0105] The first growth substrate 20a and the temporary substrate 25 can be disposed to an initial position for laser transfer. The initial position can be a starting point for transferring the plurality of red LEDs from the first growth substrate 20a to the temporary substrate 25 by the laser beam.

[0106] The mask 120 can be disposed on the upper surface of the first growth substrate 20a so that an irradiation region of the laser beam irradiated from the laser oscillator 110 is limited to a desired point.

[0107] If the first growth substrate 20a and the temporary substrate 25 are disposed at the initial position, the laser beam is irradiated to a predetermined point toward the first growth substrate 20a. The laser beam heats the first growth substrate 20a and the buffer layer 23a through the opening 121 of the mask 120.

[0108] Accordingly, the plurality of red LEDs formed on the first growth substrate 20a are separated from the buffer layer 23a of the first growth substrate 20a and attached to the buffer layer 27 of the temporary substrate 25. In this case, each electrode of the plurality of red LEDs can be in contact with the buffer layer 27.

[0109] In the process of transferring the plurality of red LEDs to the temporary substrate 25, the laser oscillator 110 and the mask 120 remain in a fixed state without changing positions. In contrast, the first growth substrate 20a and the temporary substrate 25 are moved to a predetermined position and then stopped by the stage 40, respectively. At the same time as the first growth substrate 20a and the temporary substrate 25 are stopped, the laser beam is irradiated to the first growth substrate 20a from the laser oscillator 110.

[0110] Figure 4A state in which a plurality of red LEDs are disposed on the predetermined red LED arrangement region of the temporary substrate 25 by repeatedly performing the laser transfer process is shown.

[0111] The plurality of red LEDs arranged on the temporary substrate 25 can be arranged at regular intervals in two rows (in which regions in which two rows of green LEDs and two rows of blue LEDs are arranged). In this case, the red LEDs are spaced apart from each other at the same pitch.

[0112] Reference Figure 5 The plurality of green LEDs of the second growth substrate 20b are arranged to face the temporary substrate 25. In this case, the second growth substrate 20b can be fixed to the stage at which the first growth substrate 20a was fixed in the previous operation.

[0113] The second growth substrate 20b can be disposed in a state of being held upward from the temporary substrate 25 by a predetermined gap, such that the number of green LEDs does not interfere with the red LEDs when moved along the X-Y plane by the stage.

[0114] If the second growth substrate 20b and the temporary substrate 25 are disposed in the initial position, a laser beam is irradiated to a predetermined position toward the second growth substrate 20b. In this case, the mask 120 is disposed on the upper surface of the second growth substrate 20b in the same manner as the first growth substrate 20b.

[0115] If a predetermined number of green LEDs are all transferred from the second growth substrate 20b to the temporary substrate 25 by laser transfer, a third growth substrate 20c is arranged above the temporary substrate 25, as shown in Figure 6

[0116] In this case, the third growth substrate 20c is disposed to maintain a constant gap from the temporary substrate 25, as with the second growth substrate 20b.

[0117] Subsequently, a predetermined number of blue LEDs are transferred from the third growth substrate 20c to the temporary substrate 25 by laser transfer.

[0118] Figure 7 A state in which a plurality of green LEDs and blue LEDs are disposed on the predetermined green LED arrangement region and the blue LED arrangement region of the temporary substrate 25 by repeatedly performing the laser transfer process from the second growth substrate 20b and the third growth substrate 20c is shown.

[0119] ​The red, green, and blue LEDs are transferred to the temporary substrate 25 in the order of red, green, and blue LEDs, but are not limited thereto, and can be transferred to the temporary substrate in the order of green, blue, and red LEDs, or in the order of blue, red, and green LEDs.

[0120] Therefore, if the plurality of red, green, and blue LEDs are all transferred from the first to third growth substrates 20a, 20b, and 20c to the temporary substrate 25, the plurality of LEDs of the temporary substrate are disposed to face the relay substrate 30, as shown in Figure 8

[0121] In this state, the plurality of LEDs of the temporary substrate 25 are in contact with the adhesive layer 33 of the relay substrate 30, and a laser beam is irradiated toward the temporary substrate 25 while moving along the temporary substrate 25. When the buffer layer 27 of the temporary substrate 25 is removed by the laser beam, the temporary substrate 25 can be separated from the plurality of LEDs.

[0122] Referring to Figure 9 , the plurality of red, green, and blue LEDs are transferred from the temporary substrate 25 to the relay substrate 30 and attached to the adhesive layer 33.

[0123] Next, a process of simultaneously transferring the red, green, and blue LEDs from the relay substrate 30 to a target substrate 70 will be described with reference to Figures 10 to 16

[0124] Here, the target substrate 70 can have a thin film transistor (TFT) layer formed on a front surface thereof, and can include a wiring electrically connecting a plurality of LEDs disposed on the TFT layer and a wiring of a circuit provided on a back surface of the target substrate 70.

[0125] The target substrate 70 configured as described above can go through a process of simultaneously transferring a plurality of LEDs emitting different colors to the TFT layer. The target substrate 70 that has gone through such a transfer process can be referred to as a "display module".

[0126] In this case, when the red, green, and blue LEDs are defined as a single group, simultaneously transferring a plurality of LEDs emitting different colors can mean simultaneously transferring a plurality of groups to the target substrate 70. In this case, the single group can further include a white LED.

[0127] ​​In addition, a group, which is not limited to the above-mentioned meaning, can mean simultaneously transferring a plurality of first groups to the target substrate 70 or simultaneously transferring a plurality of second groups to the target substrate 70 when the red LED and the green LED are defined as the first group and the blue LED and the white LED are defined as the second group. In this case, a plurality of first groups can be simultaneously transferred to the target substrate 70, and then a plurality of second groups can be simultaneously transferred to the target substrate 70.

[0128] As an example, the transfer process is described as being performed using the LLO method, but is not limited thereto, and the transfer process can be performed using a pick-and-place method (or a stamping method).

[0129] Figure 10 is a flowchart illustrating a process of transferring a plurality of LEDs from the relay substrate 30 to the target substrate according to an embodiment. Figures 11 to 16 is a diagram sequentially illustrating a process of transferring a plurality of LEDs from the relay substrate 30 to the target substrate 70 according to an embodiment.

[0130] Referring to Figure 11 The target substrate 70 is fixed to the stage 40 in a state in which the surfaces of the plurality of red, green, and blue LEDs to be transferred face the laser oscillator 1.

[0131] The relay substrate 30 is disposed so that the plurality of red, green, and blue LEDs face the target substrate 70. The relay substrate 30 can be fixed to the stage, and the stage can move the relay substrate 30 to a desired point along the X-Y plane as the stage moves along the X and Y axes.

[0132] The mask 13 is disposed above the relay substrate 30 and fixed together with the laser oscillator 11. The laser oscillator 11 used in the process of transferring the plurality of LEDs from the relay substrate 30 to the target substrate can be the same as the above-described laser oscillator 110.

[0133] In order to simultaneously transfer LEDs of different colors from the relay substrate 30 to the target substrate 70, the relay substrate 30 and the target substrate 70 can be disposed to initial positions by respective stages (operation S11). The initial position can be a starting point of transferring a predetermined number of red, green, and blue LEDs to the target substrate 70 in the first column of the relay substrate 30 by a laser beam.

[0134] Referring to Figure 2 , a laser beam is irradiated from the laser oscillator 11 to a predetermined point with respect to the relay substrate 30 (operation S12). Accordingly, the plurality of predetermined red, green, and blue LEDs of the first column arranged on the relay substrate 30 are separated from the adhesive layer 33 of the relay substrate 30 and transferred to the target substrate 70.

[0135] Figure 13 The relay substrate 30 in a state in which a second column of a plurality of predetermined red, green, and blue LEDs is separated is shown according to an embodiment.

[0136] As described above, since a plurality of predetermined red, green, and blue LEDs are simultaneously transferred from the relay substrate 30 onto the target substrate 70, the transfer process can be performed at a speed significantly faster than in the prior art in which LEDs of each color are sequentially transferred from a wafer (or substrate) on which LEDs of each color are formed onto a target substrate.

[0137] Referring to Figure 14 , in order to transfer other red, green, and blue LEDs of the relay substrate 30 onto the target substrate 70, the relay substrate 30 and the target substrate 70 are moved relative to each other asynchronously through a corresponding stage (operation S13).

[0138] Specifically, the relay substrate 30 is moved in the X-axis direction by a first movement distance (M1) so that a plurality of LEDs of a next column of the relay substrate 30 to be transferred onto the target substrate 70 are disposed to positions corresponding to each of a plurality of openings 13a of the mask 13 (or positions corresponding to the laser oscillator 11).

[0139] Further, the target substrate 70 is moved by a second movement distance (M2) so that positions in which a plurality of LEDs of the next column of the relay substrate 30 are to be disposed are disposed to positions corresponding to each of a plurality of openings of the mask 13 (or positions corresponding to the laser oscillator 11). Referring to Figure 15 , the second movement distance (M2) can be greater than the first movement distance (M1).

[0140] As described above, when the relay substrate 30 and the target substrate 70 are moved asynchronously, the relay substrate 30 and the target substrate 70 can be moved to positions in which a plurality of LEDs of the next column are to be transferred. In this state, a laser beam is irradiated to a predetermined point toward the relay substrate 30 (operation S14). Accordingly, a plurality of red, green, and blue LEDs of the next column are separated from the relay substrate 30 and transferred onto the target substrate 70.

[0141] Figure 16 The relay substrate 30 in a state in which a second column of a plurality of predetermined red, green, and blue LEDs is separated is shown according to an embodiment.

[0142] The processor 50 determines whether the transfer is completed based on whether the relay substrate 30 moves asynchronously with the target substrate 70 and whether the plurality of red, green, and blue LEDs are transferred to all of the predetermined positions of the target substrate 70 after the laser beam is irradiated (operation S15). If the transfer is not completed (operation S15 - No), operations S13-S15 are repeated; if the transfer is completed (operation S15 - Yes), the transfer process of the target substrate 70 ends.

[0143] The transfer process according to the above-described embodiment can include a bonding process for stably mounting the plurality of LEDs of the relay substrate 30 on the target substrate 70. Hereinafter, a transfer process according to an embodiment of the disclosure which adds the bonding process will be described.

[0144] Figure 17 is a flowchart illustrating a transfer method according to an embodiment. Figures 18A to 18D is a flowchart illustrating a transfer method according to an embodiment. Figure 17 is a diagram illustrating a process of transferring a plurality of LEDs from a relay substrate to a target substrate according to an embodiment.

[0145] Figure 17 The transfer process illustrated in FIG. 13 can correspond to a case in which the plurality of LEDs of the relay substrate 130 are mounted on the target substrate 170 in a 1:1 corresponding manner. That is, the number of the plurality of LEDs on the relay substrate 130 and the number of positions on which the LEDs are mounted on the target substrate 170 are the same.

[0146] Referring to FIG. 14, Figure 18A The target substrate 170 is disposed at a predetermined position on the first stage in a state in which a surface to which the plurality of red, green, and blue LEDs are to be transferred (hereinafter, referred to as "an upper surface of the target substrate 170") faces the laser oscillator (operation S21).

[0147] Here, the predetermined position can be a transfer position. In addition, the laser oscillator and the first stage can be the laser oscillator 11 and the stage 40 illustrated in FIG. 1, respectively. Figure 11

[0148] On the upper surface of the target substrate 170, a plurality of connection terminals 171a and 171b can be arranged at regular intervals, and an adhesive layer 173 covering the plurality of connection terminals 171a and 171b can be formed.

[0149] The plurality of connection terminals 171a and 171b can be components included in a pixel circuit provided in a TFT layer. In addition, the pixel circuit is provided on the TFT layer, and a glass substrate can be stacked on a lower side of the TFT layer. Accordingly, the target substrate 170 can be formed in a form in which the TFT layer and the glass substrate are stacked.

[0150] ​The adhesive layer 173 can be formed to cover the entire upper surface of the target substrate 170. In this case, the adhesive layer 173 can be formed in the form of a thin film or can be formed in the form of being coated by a dispenser. In this case, a portion of the adhesive layer 173 covering the plurality of connection terminals 171a and 171b can protrude only by a predetermined height greater than that of a portion of the adhesive layer 173 having no connection terminal, as shown in FIG. 17. In the case where the entire upper surface of the target substrate 170 is covered by the adhesive layer 173 of the same thickness, the portion of the adhesive layer 173 covering the connection terminals 171a and 171b can protrude more than the portion having no connection terminal due to the height of the connection terminals 171a and 171b. Figure 18A

[0151] In addition, the adhesive layer 173 can be formed on the upper surface of the target substrate 170 in a predetermined pattern shape. In this case, the adhesive layer 173 can be patterned to cover only the plurality of connection terminals 171a and 171b.

[0152] Various acrylic-based materials can be used as the adhesive component of the adhesive layer 173. For example, a transparent organic film (e.g., a transparent organic film material used in the manufacturing process of a conventional LCD panel) or an opaque organic film (e.g., a black matrix) or polyimide (PI) can be used.

[0153] The relay substrate 130 is disposed such that the plurality of red, green, and blue LEDs 141, 142, and 143 face the target substrate 70. The relay substrate 130 can be detachably fixed to a second stage different from the first stage on which the target substrate 170 is fixed.

[0154] The second stage is disposed to be movable along the X-axis and the Y-axis. Accordingly, the relay substrate 130 fixed to the second stage can be moved to a desired point along the X-Y plane.

[0155] An adhesive layer 133 is formed on one surface of the relay substrate 130. The adhesive layer 133 can be referred to as a "dynamic release layer" (DRL) and can be formed of a polyimide (PI) material to facilitate separation while the plurality of LEDs of the relay substrate 130 are transferred to the target substrate 170 using the LLO method.

[0156] As described above, in a state where the upper surface of the target substrate 170 is disposed toward the laser oscillator, the relay substrate 130 is disposed above the target substrate 170 by the second stage (operation S22). In this case, the relay substrate 130 is arranged such that the surface on which the plurality of LEDs 141, 142, and 143 are mounted faces the upper surface of the target substrate 170.

[0157] ​In this state, a laser beam is irradiated to a predetermined position with respect to the relay substrate 130. The adhesive layer 133 of the relay substrate 130 to which the laser beam is irradiated reacts to the laser beam, and the plurality of LEDs 141, 142, and 143 corresponding to the position irradiated with the laser beam are separated from the relay substrate 130 and then transferred onto the target substrate 170 (operation S23).

[0158] Referring to Figure 18B The plurality of LEDs 141, 142, and 143 transferred onto the target substrate 170 can be positioned on the top of the plurality of connection terminals 171a and 171b of the target substrate 170 corresponding to the anode 141a and the cathode 141b.

[0159] If the transfer process is completed, the second stage is driven to move the relay substrate 130 to a position deviated from the upper side of the target substrate 170. In order to perform the bonding process, the pressing member 190 is moved to a predetermined position above the target substrate 170 (operation S24). In this case, the pressing member 190 can be movably driven along the X, Y, and Z axes.

[0160] The pressing member 190 is composed of quartz or transparent glass, and a buffer layer 191 can be formed on one surface facing the target substrate 170. The buffer layer 191 has elasticity capable of protecting the plurality of LEDs 141, 142, and 143 from damage when the plurality of LEDs 141, 142, and 143 transferred onto the target substrate 170 are simultaneously pressed in the downward direction of the target substrate 170 using the pressing member 190.

[0161] The blue LED 141, the red LED 142, and the green LED 143 transferred onto the target substrate 170 can be formed in different thicknesses for each color, and the height of the position where each color of LED is mounted on the TFT layer can be differently formed. For this reason, a step can be generated between the blue LED 141, the red LED 142, and the green LED 143 transferred onto the target substrate 170. As described above, in the case where the plurality of transferred LEDs 141, 142, and 143 have a step between LEDs of different colors, it can be difficult to press each LED 141, 142, and 143 with uniform pressure when the plurality of LEDs are simultaneously pressed by the pressing member 190 to perform bonding due to the step. In order to solve such a problem, the buffer layer 191 can be formed in an appropriate thickness to press each LED 141, 142, and 143 with uniform pressure by the pressing member 190, thereby overcoming the problem caused by the step.

[0162] If the plurality of LEDs 141, 142, and 143 are pressed by the pressing member 190 at a predetermined pressure for several seconds, each of the electrodes 141a and 141b of the plurality of LEDs 141, 142, and 143 can be firmly joined to the plurality of connection terminals 171a and 171b of the TFT layer through the adhesive layer 173 (operation S25).

[0163] If the joining by the pressing member is completed, the pressing member 190 is separated from the target substrate and moved to a position deviated from the upper side of the target substrate 170.

[0164] Alternatively, instead of the method of pressing the plurality of LEDs 141, 142, and 143 using the pressing member 190, the bonding process can also be performed by using a thermal bonding method that uses a heater or an infrared (IR) laser to heat the target substrate 170 to a predetermined temperature. Figure 19 is a flowchart illustrating a transfer method according to an embodiment, Figures 20A to 20D is a flowchart sequentially illustrating a process of transferring a plurality of LEDs from a relay substrate to a target substrate according to Figure 19 is a diagram illustrating a process of transferring a plurality of LEDs from a relay substrate to a target substrate according to the embodiment shown in FIG. 10.

[0165] Referring to FIG. 10, Figure 20A In a state in which the upper surface of the target substrate 170 faces the laser oscillator, the target substrate 170 is disposed at a predetermined position in a state of being fixed to the first stage (operation S31).

[0166] The relay substrate 130 is disposed such that the plurality of red LEDs 141, green LEDs 142, and blue LEDs 143 face the target substrate 170 (operation S32). In this case, the relay substrate 130 is disposed at a position corresponding to each of the connection terminals 171a and 171b of the target substrate 170 to which each of the electrodes 141a and 141b of the plurality of LEDs is to be transferred.

[0167] Referring to FIG. 10, Figure 20B In order to perform the joining process, the relay substrate 130 is moved toward the target substrate 170 to press the relay substrate 130 against the target substrate 170 at a predetermined pressure for a predetermined time range (e.g., several seconds) (operation S33).

[0168] In this case, each of the electrodes 141a and 141b of the plurality of LEDs of the relay substrate 130 can be firmly joined to the plurality of connection terminals 171a and 171b of the TFT layer through the adhesive layer 173.

[0169] Referring to FIG. 10, Figure 20CIn this state, the laser beam is irradiated to a predetermined position with respect to the relay substrate 130. The adhesive layer 133 of the relay substrate 130 irradiated by the laser beam reacts to the laser beam, and the plurality of LEDs 141, 142, and 143 corresponding to the position irradiated with the laser beam are separated from the relay substrate 130 and then transferred onto the target substrate 170 (operation S34).

[0170] Reference Figure 20D After the transfer is completed, the relay substrate 130 is separated from the upper side of the target substrate 170.

[0171] The embodiment including the above-described bonding process can correspond to a case in which the plurality of LEDs of the relay substrate 130 are mounted on the target substrate 170 in a 1:1 corresponding manner.

[0172] The embodiment including the following bonding process can correspond to a case in which the plurality of LEDs 241, 241', 242, 242', 243, and 243' of the relay substrate 230 are mounted on the target substrate 270 in an n:1 corresponding manner. That is, the number of the plurality of LEDs 241, 241', 242, 242', 243, and 243' on the relay substrate 230 is greater than the number of positions on which the LEDs 241, 241', 242, 242', 243, and 243' are to be mounted on the target substrate 270.

[0173] Figure 21 is a flowchart illustrating a transfer method according to an embodiment. Figures 22A to 22D is a sequence of views illustrating a process of transferring a plurality of LEDs from a relay substrate to a target substrate according to an embodiment. Figure 21 is a view illustrating a process of transferring a plurality of LEDs from a relay substrate to a target substrate according to an embodiment.

[0174] Among the plurality of LEDs 241, 241', 242, 242', 243, and 243' of the relay substrate 230, two LEDs having the same color can be sequentially arranged as Figure 22A indicated, and the number of connection terminals 271a, 271b, 271c, 271d, 271e, and 271f of the target substrate 270 can be formed to be smaller than the number of the plurality of LEDs 241, 241', 242, 242', 243 of the relay substrate 230. However, the arrangement of the plurality of LEDs 241, 241', 242, 242', 243, and 243' of the relay substrate 230 is not limited to the arrangement as Figure 22A indicated.

[0175] Reference Figure 22A In a state in which the upper surface of the target substrate 270 faces the laser oscillator, the target substrate 270 is disposed at a predetermined position in a state of being fixed to the first stage (operation S41).

[0176] The relay substrate 230 is disposed so that the plurality of red LEDs 241, green LEDs 242, and blue LEDs 243 are directed toward the target substrate 270 (operation S42). In this case, the relay substrate 230 is disposed at positions corresponding to each of the plurality of electrodes 241a, 241b, 242a, 242b, 243a, and 243b of the plurality of LEDs 241, 241', 242, 242', 243, and 243' at positions of each of the connection terminals 271a, 271b, 271c, 271d, 271e, and 271f of the target substrate 270.

[0177] In this state, a laser beam is irradiated to a predetermined position with respect to the relay substrate 230.

[0178] Thus, as Figure 22B indicated, the adhesive layer 233 of the relay substrate 230 irradiated by the laser beam reacts to the laser beam, and the plurality of LEDs 241, 241', 242, 242', 243, and 243' corresponding to the position irradiated with the laser beam are separated from the relay substrate 230 and then transferred onto the target substrate 270 (operation S43).

[0179] The relay substrate 230 is moved to a position deviated from the upper side of the target substrate 270, and the remaining LEDs are not transferred.

[0180] Referring to Figure 22C , in order to perform the bonding process, the pressing member 290 is moved to a predetermined position above the target substrate 270 (operation S44). In this case, the pressing member 290 can be movably driven along the X, Y, and Z axes.

[0181] If the pressing member 290 presses the plurality of LEDs 241, 241', 242, 242', 243, and 243 with a predetermined pressure for a predetermined time range (for example, several seconds), each of the plurality of electrodes 241a, 241b, 242a, 242b, 243a, and 243b of the plurality of LEDs 241, 242, and 243 can be firmly bonded to the plurality of connection terminals 271a, 271b, 271c, 271d, 271e, and 271f through the adhesive layer 273 of the TFT (operation S45).

[0182] Referring to Figure 22D , if the bonding by the pressing member is completed, the pressing member 290 is separated from the target substrate 270 and moved to a position deviated from the upper side of the target substrate 270.

[0183] Alternatively, instead of pressing the plurality of LEDs 241, 242, and 243 with the pressing member 290, a bonding process using heat can also be performed by heating the target substrate 270 to a predetermined temperature by using a heater or irradiating IR laser to the target substrate 270.

[0184] Figure 23 is a flowchart illustrating a transfer method according to an embodiment, Figures 24A to 24D is a diagram sequentially illustrating a process of transferring a plurality of LEDs from a relay substrate to a target substrate according to an embodiment illustrated in FIG. 2. Figure 23

[0185] Referring to FIG. 2, Figure 24A In a state in which the upper surface of the target substrate 270 faces the laser oscillator, the target substrate 270 is disposed at a predetermined position in a state of being fixed to the first stage (operation S51).

[0186] The relay substrate 230 is disposed such that the plurality of red LEDs 241, 241', green LEDs 242, 242', and blue LEDs 243 and 243' face the target substrate 270 (operation S52). In this case, the relay substrate 230 is disposed at a position corresponding to each of the connection terminals 271a, 271b, 271c, 271d, 271e, and 271f of the target substrate 270 to which each of the electrodes 241a, 241b, 242a, 242b, 243a, and 243b of the plurality of LEDs is to be transferred.

[0187] Referring to FIG. 2, Figure 24B In order to perform the bonding process, the relay substrate 230 is moved toward the target substrate 270 to press the relay substrate 230 against the target substrate 170 with a predetermined pressure for a predetermined time range (operation S53).

[0188] In this case, each of the electrodes 241a, 241b, 242a, 242b, 243a, and 243b of the plurality of LEDs 241, 242, and 243 of the relay substrate 230 can be firmly bonded to the plurality of connection terminals 271a, 271b, 271c, 271d, 271e, and 271f of the TFT layer through the adhesive layer 273.

[0189] The LEDs 241', 242', and 243' that are not transferred to the target substrate 270 at the time of performing the pressing are maintained at a predetermined distance from the adhesive layer 273, such that each of the electrodes 241a', 241b', 242a', 242b', 243a', and 243b' is not attached to the adhesive layer 273 of the target substrate 270. To this end, the adhesive layer 273 can need to be formed to have an appropriate thickness.

[0190] Referring to FIG. 2, Figure 24C ​In this state, a laser beam is irradiated to a predetermined position with respect to the relay substrate 230. The adhesive layer 233 of the relay substrate 230 to which the laser beam is irradiated reacts to the laser beam, and the plurality of LEDs 241, 242, and 243 corresponding to the position irradiated with the laser beam are separated from the relay substrate 230 and then transferred onto the target substrate 270 (operation S54).

[0191] Reference Figure 24D After the transfer is completed, the relay substrate 230 is separated from the upper side of the target substrate 270.

[0192] Alternatively, the method according to the above-described embodiments can be implemented in the form of an application program that can be installed on an existing LED transfer device.

[0193] Further, the method of the above-described embodiments can be implemented by upgrading the software or hardware of an existing LED transfer device.

[0194] Further, the above-described embodiments can also be executed through an embedded server included in the LED transfer device or an external server of the LED transfer device.

[0195] The above-described embodiments can be implemented in a computer or a computer-readable medium using software, hardware, or a combination of software and hardware. In some cases, the embodiments described in the disclosure can be implemented by the processor 50 itself. According to the software implementation, the embodiments described in the disclosure, such as processes and functions, can be implemented as separate software modules. Each software module can perform one or more functions and operations described in the disclosure.

[0196] Computer instructions for performing the processing operations of the LED transfer device 1 according to the above-described embodiments can be stored in a non-transitory computer-readable medium. The computer instructions stored in the non-transitory computer-readable medium allow a specific device to perform the processing operations of the LED transfer device 1 according to the above-described embodiments based on execution by a processor of the specific device.

[0197] The non-transitory computer-readable medium is a machine-readable medium that semi-permanently stores data. Specific examples of the non-transitory computer-readable medium can include a compact disc (CD), a digital versatile disc (DVD), a hard disk, a Blu-ray disc, a universal serial bus (USB), a memory card, a read-only memory (ROM), etc.

[0198] Although the embodiments have been described above individually, the respective embodiments are not necessarily implemented in a discrete manner, but the configuration and operation of each embodiment can be implemented in combination with at least one other embodiment.

[0199] While the embodiments of the present disclosure have been illustrated and described above, the present disclosure is not limited to the specific embodiments described above, but can be modified by those skilled in the art without departing from the scope and spirit of the present disclosure as claimed in the appended claims. These modifications should not be individually understood from the technical spirit or prospect of the present disclosure.

Claims

1. An LED transfer method, comprising: A transfer substrate is disposed between a target substrate and a laser oscillator, wherein multiple LEDs of different colors are sequentially arranged on the transfer substrate in at least one row or at least one column, wherein multiple LEDs formed on each growth substrate are transferred to the transfer substrate via a temporary substrate, wherein the multiple LEDs formed on each growth substrate are transferred to the temporary substrate in at least one row or at least one column for each color; and By irradiating the target substrate with a laser beam from the laser oscillator, the plurality of LEDs of different colors are simultaneously transferred from the transfer substrate to a predetermined point on the target substrate.

2. The LED transfer method according to claim 1, wherein during the transfer, the plurality of LEDs are formed as a group to be transferred simultaneously onto the target substrate.

3. The LED transfer method according to claim 2, wherein during the transfer, a plurality of groups, including the group, are simultaneously transferred to the target substrate at predetermined intervals.

4. The LED transfer method according to claim 3, wherein the group comprises red LEDs, green LEDs and blue LEDs.

5. The LED transfer method according to claim 4, wherein the group further comprises a white LED.

6. The LED transfer method according to claim 1, further comprising: The transfer substrate is moved a first moving distance; The target substrate is moved a second distance, which is different from the first moving distance; as well as Multiple other LEDs of different colors are simultaneously transferred from the transfer substrate to the target substrate.

7. The LED transfer method according to claim 1, further comprising: After the transfer, the plurality of LEDs are bonded to the target substrate by pressing the plurality of LEDs with a pressing member.

8. The LED transfer method according to claim 7, wherein the pressing member presses the plurality of LEDs by means of a buffer layer formed on a surface facing the plurality of LEDs.

9. The LED transfer method according to claim 1, further comprising: Prior to the transfer, the relay substrate is engaged by pressing the relay substrate toward the target substrate.

10. The LED transfer method according to claim 1, further comprising: After the transfer, the plurality of LEDs are bonded to the target substrate using a thermal bonding method.

11. The LED transfer method according to claim 10, wherein the thermal bonding method includes heating the target substrate using a heater or heating the target substrate using an infrared laser.

12. A non-transitory computer-readable medium comprising a program for performing an LED transfer method, the LED transfer method comprising: A transfer substrate is disposed between a target substrate and a laser oscillator, wherein multiple LEDs of different colors are sequentially arranged on the transfer substrate in at least one row or at least one column, wherein multiple LEDs formed on each growth substrate are transferred to the transfer substrate via a temporary substrate, wherein the multiple LEDs formed on each growth substrate are transferred to the temporary substrate in at least one row or at least one column for each color; and By irradiating the target substrate with a laser beam from the laser oscillator, the plurality of LEDs of different colors are simultaneously transferred from the transfer substrate to a predetermined point on the target substrate.

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