Roll based transfer apparatus, roll based transfer method using the same, roll based repair method using the same, and display panel manufactured using the same

Abstract

In a roll-based transfer device for forming variable pitch, a roll-based transfer method using the same, a roll-based repair method using the same, and a display panel manufactured using the same, the roll-based transfer device comprises a transfer substrate, a base substrate, a transfer roller, and a laser irradiation unit. A plurality of elements are arranged on the transfer substrate. A transfer element is selected and mounted among the elements on the base substrate. The transfer roller selectively picks the transfer element from the transfer substrate and then transfers the picked element to the base substrate. The laser irradiation unit weakens the adhesion force between the transfer element and the transfer substrate.

Description

Technology Field

[0001] The present invention relates to a roll-based transfer apparatus for forming a variable pitch, a roll-based transfer method using the same, a roll-based repair method using the same, and a display panel manufactured using the same. More specifically, the invention relates to a roll-based transfer apparatus for forming a variable pitch, a roll-based transfer method using the same, a roll-based repair method using the same, and a display panel manufactured using the same, which enables the rapid and precise mounting of components with varying spacing through a series of processes using a transfer process with a transfer roller, thereby allowing the production of various electronic devices and display panels that meet user requirements by having various component spacings and component arrangement shapes, and enables the selective removal of defective components and the precise re-mounting of components at the corresponding locations. Background Technology

[0002] As various types of electronic devices become miniaturized and used in multiple array forms, the technology for mounting them on substrates must also be executed with precision; at the same time, there is a demand for process speed that considers yield—that is, for improved productivity.

[0003] To improve the efficiency of conventional processes, technology is being developed to perform the process by continuously supplying substrates as a method for mounting electronic devices. For example, Korean Registered Patent No. 10-1387847 discloses a technology that improves process productivity by transferring electronic devices from one substrate to another while continuously transporting substrates.

[0004] Furthermore, such mounting technology for electronic devices is applied in the repair of defective devices; for example, Korean Published Patent No. 10-2024-0095829 discloses a technology for removing and remounting defective devices using a continuously provided substrate.

[0005] However, in the case of the device mounting or repair process using the continuous provision of conventionally developed substrates, a pair of substrates—namely, the substrate on which the device is formed and the substrate on which the device is to be transferred—must come into contact with each other so that they correspond one-to-one at the same location, thus requiring more precise control during the continuous process. Furthermore, as the demand for electronic devices with various models and form factors increases according to user requirements, there is an increasing demand for technology that can manufacture user-customized electronic devices with various device densities using a transfer substrate on which densely packed devices are formed with a constant spacing. Prior art literature

[0006] Republic of Korea Registered Patent No. 10-1387847 Republic of Korea Published Patent No. 10-2024-0095829 The problem to be solved

[0007] Accordingly, the technical problem of the present invention is conceived from this point, and the objective of the present invention is to provide a roll-based transfer device for forming variable pitch that enables the rapid and precise mounting of devices with varying spacing through a series of processes using a transfer process with a transfer roller, thereby allowing for the production of various electronic devices and display panels that meet user requirements by having various device spacings and device arrangement shapes (polygonal or irregular shapes such as circles and triangles in addition to squares), and allows for the selective removal of defective devices and precise re-mounting of devices at the corresponding locations.

[0008] In addition, another objective of the present invention is to provide a roll-based transfer method using the transfer device.

[0009] In addition, another objective of the present invention is to provide a roll-based repair method using the above-described transfer device.

[0010] In addition, another objective of the present invention is to provide a display panel manufactured using the above-described transfer device. means of solving the problem

[0011] A roll-based transfer device according to one embodiment for realizing the purpose of the present invention described above includes a transfer substrate, a base substrate, a transfer roller, and a laser irradiation unit. A plurality of elements are arranged on the transfer substrate. A transfer element is selected and mounted among the elements on the base substrate. The transfer roller selectively picks the transfer element from the transfer substrate and then transfers the picked element to the base substrate. The laser irradiation unit weakens the adhesion force between the transfer element and the transfer substrate.

[0012] In one embodiment, the transfer roller can rotate on the transfer substrate to pick the transfer element to the surface portion, and rotate on the base substrate to mount the transfer element from the surface portion to the base substrate.

[0013] In one embodiment, while the transfer roller presses the transfer element, the laser irradiation unit can irradiate a laser between the transfer element and the transfer substrate.

[0014] In one embodiment, the system may further include a control unit that provides a pressure to the transfer roller in a direction toward the transfer substrate or the base substrate, and a transfer unit that continuously transfers the transfer substrate and the base substrate in one direction.

[0015] In one embodiment, the laser irradiation unit is transferred relative to the transfer substrate and can irradiate a laser to ablate the adhesive layer between the transfer element and the transfer substrate, generate gas at the interface of the adhesive layer, or induce a volume change of the adhesive layer.

[0016] In one embodiment, the laser irradiation unit may include a laser source unit that provides the laser, and a scan unit that selectively irradiates the laser to the transfer element.

[0017] In one embodiment, the laser irradiation unit may further include a lens unit that equalizes the laser between the scanning unit and the transfer substrate.

[0018] In one embodiment, the lens portion may have an elliptical cross-section.

[0019] In one embodiment, the system may further include a first alignment unit for aligning the transfer substrate and the transfer roller, and a second alignment unit for aligning the base substrate and the transfer roller.

[0020] In one embodiment, the system further includes an additional alignment unit that forms an alignment marker on the surface of the transfer roller, and the first alignment unit or the second alignment unit can perform alignment based on the alignment marker.

[0021] In one embodiment, a removal unit may be further included that is located adjacent to the transfer roller and cleans the transfer element picked by the transfer roller.

[0022] In one embodiment, a plurality of transfer substrates are supplied, each having different types of components mounted thereon, and different types of transfer components picked from the transfer substrates can be mounted on a single base substrate.

[0023] According to another embodiment for realizing the purpose of the present invention described above, the roll-based transfer device comprises a transfer substrate, a base substrate, a transfer roller, and a connection aid. A plurality of elements are mounted on the transfer substrate. A transfer element is selected and mounted among the elements on the base substrate. The transfer roller selectively picks the transfer element from the transfer substrate and then transfers the picked element to the base substrate. The connection aid connects the transfer element to the base substrate.

[0024] In one embodiment, the connection assisting member can irradiate a laser to the transfer element.

[0025] In one embodiment, a solder, anisotropic conductive film (ACF), or anisotropic conductive paste (ACP) is formed between the transfer element and the base substrate, and as the laser is irradiated, the transfer element and the base substrate can be connected to each other through the solder, ACF, or ACP.

[0026] In one embodiment, a heater portion for applying heat to the solder, ACF, or ACP may be provided on the base plate where the transfer roller or the base substrate is located.

[0027] In one embodiment, the base substrate transmits a laser, and the laser may be a laser in the NIR band that penetrates the base substrate and is irradiated.

[0028] In one embodiment, a control unit may be further included that simultaneously irradiates a laser onto the transfer element and provides a pressure to the transfer roller in a direction toward the base substrate.

[0029] In one embodiment, a laser irradiation unit that weakens the adhesion force between the transfer element and the transfer substrate may be further included.

[0030] In one embodiment, the transfer substrate transmits a laser, and the laser irradiated by the laser irradiation unit can penetrate the transfer substrate and be provided to the transfer element.

[0031] In one embodiment, the transfer substrate and the base substrate are continuously transported in one direction, and the transfer roller rotates pressurized on the transfer substrate to pick the transfer element, and then rotates on the base substrate to transfer the transfer element.

[0032] A roll-based transfer method according to one embodiment for realizing another objective of the present invention described above comprises the steps of mounting a plurality of elements on a transfer substrate, rotating on the transfer substrate using a transfer roller to selectively pick a transfer element among the elements, and rotating on a base substrate to transfer the transfer element of the transfer roller to the base substrate.

[0033] In one embodiment, the step of selectively picking the transfer element may include the step of positioning the transfer roller on the upper part of the transfer substrate, the step of pressing and rotating the transfer roller on the transfer substrate and irradiating the transfer element with a laser, and the step of picking only the transfer element to the surface portion of the transfer roller.

[0034] In one embodiment, in the step of irradiating a laser onto the transfer element, the laser may be irradiated to ablate the adhesive layer between the transfer element and the transfer substrate, generate gas at the interface of the adhesive layer, or induce a change in the volume of the adhesive layer.

[0035] In one embodiment, in the step of irradiating a laser onto the transfer element, the irradiation direction of the laser is controlled by a scanning unit so that the laser can be irradiated only onto the transfer element.

[0036] In one embodiment, the step of transferring the transfer element may include the step of positioning the transfer roller on the upper part of the base substrate, the step of pressing and rotating the transfer roller on the base substrate and mounting the transfer element onto the base substrate, and the step of connecting the base substrate and the transfer element.

[0037] In one embodiment, the method may further include the step of forming an alignment marker on the surface of the transfer roller before the step of selectively picking the transfer element, or forming an alignment marker on the picked electronic element after the step of selectively picking the transfer element.

[0038] In one embodiment, in the step of selectively picking the transfer element, the transfer roller and the transfer substrate may be aligned based on the alignment marker, and in the step of transferring the transfer element, the transfer roller and the base substrate may be aligned based on the alignment marker.

[0039] In one embodiment, after the step of selectively picking the transfer element, the method may further include a step of cleaning the transfer element using a removal unit located adjacent to the transfer roller.

[0040] In one embodiment, the elements mounted on the transfer substrate are all identical elements, and the transfer elements transferred to the base substrate may be spaced apart at equal or different intervals.

[0041] In one embodiment, the spacing of the elements mounted on the transfer substrate and the spacing of the elements transferred to the base substrate may be different from each other.

[0042] In one embodiment, a plurality of transfer substrates are supplied, and the types of components mounted on each transfer substrate are different from one another, and different types of transfer components picked from the transfer substrates can be transferred to a single base substrate.

[0043] In one embodiment, the spacing of the elements mounted on the transfer substrate and the spacing of the elements transferred to the base substrate may be the same or different from each other.

[0044] In one embodiment, the transfer substrates include first to third transfer substrates, and some of the first elements mounted on the first transfer substrate may be selectively transferred to the base substrate, some of the second elements mounted on the second transfer substrate may be selectively transferred to the base substrate, and some of the third elements mounted on the third transfer substrate may be selectively transferred to the base substrate.

[0045] In one embodiment, the first element is an R (red) LED element, the second element is a G (green) LED element, and the third element is a B (blue) LED element, and the R / G / B LED elements can be mounted on the base substrate in a predetermined arrangement.

[0046] A roll-based repair method according to one embodiment for realizing another objective of the present invention described above may include the steps of: selecting a defective element from a base substrate on which the element is transferred; removing the defective element from the base substrate using a transfer roller; selectively picking a transferred element among the elements mounted on the transfer substrate using the transfer roller; and transferring the transferred element of the transfer roller to the location of the defective element on the base substrate.

[0047] In one embodiment, in the step of selecting the defective elements, power can be provided to the elements transferred to the base substrate to induce lighting.

[0048] In one embodiment, the step of removing the defective element may include the step of positioning the transfer roller on the upper part of the base substrate, the step of pressing and rotating the transfer roller on the base substrate and irradiating the defective element with a laser, and the step of picking only the defective element onto the surface of the transfer roller.

[0049] In one embodiment, in the step of irradiating the defective element with a laser, the laser may be irradiated onto the solder, anisotropic conductive film (ACF), or anisotropic conductive paste (ACP) between the defective element and the base substrate.

[0050] In one embodiment, the base substrate transmits a laser, and the laser may be a laser in the NIR band that penetrates the base substrate and is irradiated.

[0051] In one embodiment, the step of selectively picking the transfer element may involve picking the element corresponding to the location of the defective element among the elements mounted on the transfer substrate as the transfer element.

[0052] In one embodiment, the step of selectively picking the transfer element may include the step of positioning the transfer roller on the upper part of the transfer substrate, the step of pressing and rotating the transfer roller on the transfer substrate and irradiating the transfer element with a laser, and the step of picking only the transfer element to the surface portion of the transfer roller.

[0053] In one embodiment, the step of transferring the transfer element may include the step of positioning the transfer roller on the upper part of the base substrate, the step of pressing and rotating the transfer roller on the base substrate and mounting the transfer element at the location of the defective element on the base substrate, and the step of connecting the base substrate and the transfer element.

[0054] In one embodiment, in the step of connecting the base substrate and the transfer element, as the laser is irradiated, the solder between the transfer element and the base substrate is melted and the transfer element and the base substrate can be connected to each other.

[0055] In one embodiment, prior to the step of connecting the base substrate and the transfer element, a solder flux may be coated on the surface of the solder.

[0056] According to one embodiment for realizing another objective of the present invention described above, the display panel comprises the base substrate on which the transfer element is transferred using the roll-based transfer device, and the driving unit for driving the transfer element. In this case, the transfer element is an LED (light emitting diode) element.

[0057] In one embodiment, the LED element may be arranged on the base substrate with a predetermined spacing based on a preset pixel density.

[0058] In one embodiment, the spacing between the LED elements is narrow in the high-resolution region with high pixel density, and the spacing between the LED elements may be large in the low-resolution region with low pixel density.

[0059] In one embodiment, the high-resolution area may be positioned in the user's near peripheral area, and the low-resolution area may be positioned in the user's far peripheral area. Effects of the invention

[0060] According to embodiments of the present invention, by selectively transferring some of the elements mounted on a transfer substrate to a base substrate, the transferred elements mounted on the base substrate are formed with a predetermined spacing or a predetermined pattern, thereby enabling the production of a display panel in which electronic elements such as LEDs are formed with various patterns and spacings. In this case, in addition to the display panel, it may be possible to produce various electronic devices in which a plurality of photodiode elements, biosensors, MLCCs, etc. are formed in an array.

[0061] That is, by selectively transferring some of the elements among those densely arranged at a specific pitch on a transfer substrate, the elements mounted on the base substrate can be arranged to have various pitches different from the pitch of the densely arranged elements, thereby enabling the fabrication of various electronic devices including display panels having various patterns and spacings.

[0062] For example, in the case of a display panel manufactured as described above, the pitch between subpixels on which LEDs are mounted can be varied. Furthermore, by implementing a process of individually picking and mounting LEDs—that is, a process of selectively picking different elements mounted on multiple transfer substrates and mounting them on a single base substrate—it is possible to manufacture a display panel in which LEDs are arranged with a predetermined pitch relative to each other.

[0063] Furthermore, display panels with various pixel densities can be manufactured through a single process; in particular, considering the user's field of view, it is possible to produce a single display panel that has a higher pixel density in the central field of view and a lower pixel density in the peripheral field of view. Through this, it is possible to produce various display panels tailored to diverse user requirements or manufacturing environments.

[0064] Meanwhile, picking from the transfer substrate and transfer to the base substrate are performed sequentially by a single transfer roller, and the transfer roller has a cylindrical roller shape with a circular or fan-shaped cross-section, such as in a roll-to-roll or roll-to-plate process, and rotates on the transfer substrate and the base substrate to continuously perform picking and transfer, thereby improving the speed, efficiency, and precision of the manufacturing process of the display panel through the transfer process.

[0065] In addition, when picking from the transfer substrate, a laser is irradiated to weaken the adhesion between the device and the transfer substrate (ablation), thereby inducing the device mounted on the transfer substrate to be picked more easily by the transfer roller. At this time, since the laser must be selectively irradiated only toward the device to be picked, the laser irradiation unit may include a separate scanning unit to selectively scan only the device to be transferred among the devices mounted on the transfer substrate, thereby weakening the adhesion. Thus, even when the transfer roller contacts and rotates along the upper surface of all devices mounted on the transfer substrate, only the devices scanned by the scanning unit can be selectively picked. Furthermore, although the position of the device may be misaligned or the device may be damaged when the laser is irradiated, irradiating the laser while the transfer roller is under pressure allows the roller's soft stamp to fix the position of the device and absorb the impact caused by the laser pulse, thereby reducing device damage.

[0066] In addition, when transferring a device from the transfer roller to the base substrate, in order to strengthen the adhesion between the device and the base substrate, the solder, anisotropic conductive film (ACF), or anisotropic conductive paste (ACP) formed on the lower part of the device can be induced to adhere (solder) through laser irradiation. By doing so, the adhesion between the device and the base substrate is formed to be higher than the adhesion between the transfer roller and the device, thereby allowing all devices picked by the transfer roller to be transferred to the base substrate with high reliability.

[0067] At this time, when performing the connection through the melting of the solder, by maintaining the wavelength of the irradiated laser in a wavelength band with high transmittance on the base substrate, for example, the NIR band, energy absorption on the base substrate is minimized, and the energy absorption of the solder and the resulting heating and melting are performed more effectively, thereby enabling a more stable connection between the device and the base substrate with high reliability.

[0068] In the above-mentioned picking and transfer process, a separate pressure is applied to the transfer roller, thereby enabling accurate picking and transfer of the selected element.

[0069] Furthermore, in the picking and transfer process described above, alignment between the transfer substrate and the transfer roller, as well as alignment between the transfer roller and the base substrate, are both important, and thus, the alignment can be accurately induced in the repetitive process through the alignment units. Meanwhile, by separately forming an alignment marker on the transfer roller through an additional alignment unit, more accurate alignment can be performed in the picking and transfer process using the alignment marker.

[0070] In addition, since residue may exist during the process of transferring the device picked by the transfer roller from the transfer substrate, cleaning of the device can be performed by performing plasma treatment through a removal unit, thereby improving the electrical stability of the device finally transferred to the base substrate.

[0071] Furthermore, by using the roll-based transfer device described above to perform repair of defective components, it is possible to manufacture display panels with varying pixel pitches using a single transfer device, as well as simultaneously perform a repair process to replace defective components on the display panel, thereby improving process efficiency and convenience.

[0072] That is, among the components mounted on the base substrate, defective components can be picked out and removed externally using the transfer roller, and the repair process can be performed by transferring normal components back to the area where the defective components were removed through the transfer method described above.

[0073] In this case, when picking a defective component from the base substrate, selective picking of the defective component can be performed by irradiating a laser between the defective component and the base substrate to melt the solder and induce picking of the defective component. At this time, the irradiated laser may be, for example, in the NIR band, which can similarly perform melting of the solder more effectively.

[0074] In particular, by using a single transfer roller, defective components can be picked and removed, and new good components can be re-transferred more accurately and quickly, thereby improving the speed and efficiency of the repair process. That is, it is sufficient for the transfer roller to be pressed and rotated on the transfer substrate and the base substrate, and by selecting the position of the laser being irradiated, defective components are picked and removed and new components are picked and transferred, thereby improving the efficiency and speed of the process. Brief explanation of the drawing

[0075] FIG. 1 is a block diagram illustrating a roll-based transfer device according to one embodiment of the present invention. Figure 2 is a schematic diagram illustrating the roll-based transfer device of Figure 1. Figure 3 is a flowchart illustrating a roll-based transfer method using the transfer device of Figure 1. FIG. 4a is a flowchart illustrating the picking step using the transfer roller of FIG. 3, and FIG. 4b is a flowchart illustrating the transfer step using the transfer roller of FIG. 3. Figure 5 is a process diagram illustrating the picking step using the transfer roller of Figure 3. FIGS. 6 and FIGS. 7 are schematic diagrams illustrating examples of laser irradiation through a laser irradiation unit in the picking step of FIG. 5. Figure 8 is a process diagram illustrating the step of transferring using the transfer roller of Figure 3. FIG. 9 is a process diagram illustrating an example of connection through a connection aid in the transfer step of FIG. 8. FIGS. 10a and FIGS. 10b are plan views illustrating examples of pixel portions of a display panel manufactured using the transfer device of FIG. 1. FIGS. 11a to 11c are plan views illustrating examples of display panels manufactured using the transfer device of FIG. 1. FIG. 12 is a schematic diagram illustrating another example of a display panel manufactured using the transfer device of FIG. 1. FIG. 13 is a process diagram illustrating the picking and transfer steps using a transfer roller in a roll-based transfer method according to another embodiment using the transfer device of FIG. 1. FIG. 14 is a process diagram illustrating the step of performing alignment in a roll-based transfer method according to another embodiment using the transfer device of FIG. 1. FIG. 15 is a process diagram illustrating the step of performing cleaning in a roll-based transfer method according to another embodiment using the transfer device of FIG. 1. FIG. 16 is a block diagram illustrating a roll-based transfer device according to another embodiment of the present invention. FIG. 17 is a flowchart illustrating a roll-based repair method using the transfer device of FIG. 16. FIG. 18 is a flowchart illustrating the step of removing defective components using the transfer roller of FIG. 17. FIG. 19 is a process diagram illustrating the step of removing defective components using the transfer roller of FIG. 17. FIG. 20 is a process diagram illustrating the step of transferring a component to the location of a defective component using the transfer roller of FIG. 17. Specific details for implementing the invention

[0076] The present invention is susceptible to various modifications and may take various forms, and embodiments are to be described in detail in the text. However, this is not intended to limit the invention to the specific disclosed forms, and it should be understood that the invention includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention. Similar reference numerals have been used for similar components in the description of each figure. Terms such as "first," "second," etc., may be used to describe various components, but said components should not be limited by said terms.

[0077] The above terms are used solely for the purpose of distinguishing one component from another. The terms used in this application are used merely to describe specific embodiments and are not intended to limit the invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, terms such as "comprising" or "consisting of" are intended to specify the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0078] Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the attached drawings.

[0079] FIG. 1 is a block diagram illustrating a roll-based transfer device according to an embodiment of the present invention. FIG. 2 is a schematic diagram illustrating the roll-based transfer device of FIG. 1.

[0080] Referring to FIGS. 1 and 2, the roll-based transfer device (10, hereinafter referred to as the transfer device) according to the present embodiment includes a transfer unit (100), a transfer substrate (200), a base substrate (300), a transfer roller (400), a control unit (410), a laser irradiation unit (500), a connection assist unit (600), and first and second alignment units (700, 750).

[0081] The above transfer unit (100) corresponds to a transfer stage that transfers the transfer substrate (200) and the base substrate (300), and includes a first transfer unit (110) that performs transfer in a first direction (X) and a second transfer unit (120) that performs transfer in a second direction (Y). Of course, transfer in a third direction (Z) or rotation around the first to third directions (X, Y, Z) as a rotational axis can also be implemented as needed, but a detailed description is omitted below. That is, the description focuses on the transfer of the transfer substrate (200) and the base substrate (300) along the first direction (X), and it is obvious that transfer and rotation in various directions can be performed in other necessary processes.

[0082] Furthermore, although not illustrated, the transfer unit (100) may be composed of a providing roll and a receiving roll that continuously transfer the transfer substrate (200) and the base substrate (300), such as in roll-to-roll transfer.

[0083] The transfer substrate (200) is transferred in the first direction (X) by the transfer unit (100). The transfer substrate (200) may be a flexible substrate, and if the transfer substrate (200) is a flexible substrate, it may be continuously transferred in the first direction (X) through roll-to-roll transfer as described above. At this time, the transfer substrate (200) may be positioned on a transfer plate (210) that is transferred by the transfer unit (100). Meanwhile, the transfer plate (210) may be a transparent plate.

[0084] On the upper surface of the above-mentioned transfer board (200), a plurality of elements (800) are mounted with a predetermined pitch, and at this time, the pitch (distance) between the elements (800) is sufficient if the spacing is such that individual picking of the elements (800) is possible.

[0085] Meanwhile, mounting the elements (800) onto the upper surface of the transfer substrate (200) can be performed in advance through a separate process, and the process of mounting the elements (800) onto the upper surface of the transfer substrate (200) is not limited.

[0086] Furthermore, the process of mounting the elements (800) onto the upper surface of the transfer substrate (200) may also be performed in the transfer device (10). That is, elements transferred through the transfer substrate (130) may be mounted onto the upper surface of the transfer substrate (200), and the process of mounting such elements is not limited.

[0087] Meanwhile, the elements (800) mounted on the transfer substrate (200) can maintain a state of being attached to each other by an adhesive layer (not shown) formed between the transfer substrate (200). At this time, the transfer substrate (200) may be a transparent substrate, and as described later, the adhesive layer may undergo so-called ablation, generate gas at the interface of the adhesive layer, or induce a local volume change of the adhesive layer, thereby reducing the adhesive strength.

[0088] The base substrate (300) is positioned adjacent to the transfer substrate (200) and is transported along the first direction (X) through the transfer unit (100) described above. The base substrate (300) may also be a flexible substrate, similar to the transfer substrate (200), and if the base substrate (300) is a flexible substrate, it can be continuously transported in the first direction (X) through roll-to-roll transport as described above.

[0089] At this time, the base substrate (300) may be positioned on a base plate (310) that is transported by the transport unit (100). The base plate (310) may also be a transparent plate.

[0090] The above base substrate (300) is a substrate on which an element is transferred to the upper surface, and as the element is transferred in this way, the above base substrate (300) can be manufactured into a display panel (900). That is, if the element mounted on the above base substrate (300) is an electronic element such as an LED (light emitting device), a driving unit and a wiring unit for driving the element are additionally formed, and the above display panel (900) can be manufactured. However, since various conventionally disclosed processes can be applied in relation to the manufacturing of such a display panel, in this embodiment, the specific process of manufacturing the above base substrate (300) into the above display panel (900) is omitted.

[0091] The base substrate (300) may also be a transparent substrate, and a laser may be irradiated to improve the connection between the base substrate (300) and the element during the process of transferring the element to the base substrate (300), and this will be described later.

[0092] Meanwhile, a cleaning substrate (250) may be additionally provided between the transfer substrate (200) and the base substrate (300). The cleaning substrate (250) cleans an element (hereinafter referred to as a transfer element) that is picked from the transfer substrate (200) and transferred to the base substrate (300), thereby removing foreign substances contained in the transfer element and improving the electrical stability of the transfer element.

[0093] As described above, the transfer substrate (200), the base substrate (300), and the cleaning substrate (250) can be continuously transferred in the first direction (X) as a whole by the transfer unit (100) as illustrated. That is, FIG. 2 illustrates a transfer state in which elements picked from one transfer substrate (200) are transferred to one base substrate (300).

[0094] In contrast, if the elements picked from one transfer substrate (200) are transferred to a plurality of base substrates (300), they can be transferred continuously in the order of 'transfer substrate - base substrate 1 - base substrate 2' (the cleaning substrate is omitted), and if the elements picked from a plurality of transfer substrates (200) are transferred to one base substrate (300), they can be transferred continuously in the order of 'transfer substrate 1 - transfer substrate 2 - base substrate'.

[0095] Furthermore, a plurality of transfer substrates and a plurality of base substrates may be continuously transferred in an arrangement such as 'transfer substrate 1 - base substrate 1 - transfer substrate 2 - base substrate 2' or an arrangement such as 'transfer substrate 1 - transfer substrate 2 - base substrate 1 - base substrate 2', and such arrangements of transfer substrates and base substrates may be combined in various ways.

[0096] Ultimately, this continuous arrangement structure of the transfer substrate and base substrate can be pre-set by considering the types of the picked and transferred elements, and the pitch between the transferred elements.

[0097] Furthermore, even when a transfer substrate (200) and a base substrate (300) are arranged as in FIG. 2, picking and transfer can be performed repeatedly, such as 'picking-transfer-picking-transfer', and in this case, the transfer unit (100) can perform repeated transfer in a positive first direction (+X) and a negative first direction (-X).

[0098] The transfer roller (400) picks a transfer element (810) among the elements (800) mounted on the transfer substrate (200) and transfers the transfer element (810) to the base substrate (300). As described above, if the transfer roller (400) picks only some of the elements (810) among the elements (800) mounted on the transfer substrate (200), the remaining elements remain on the transfer substrate (200) as residual elements (820). These residual elements (820) may be picked and transferred to the base substrate through a subsequent picking process, or if no additional picking is performed, they may be removed to the outside along with the transfer substrate (200).

[0099] However, since the above-mentioned element (800) may be an electronic element such as an LED or micro LED as previously exemplified, it is obvious that it is necessary to design the arrangement of the electronic elements in the display panel (900) so that they are all used through subsequent picking or through a repair process described later.

[0100] The above transfer roller (400) may have a cylindrical shape with a circular cross-section overall, and is extended by a predetermined length in the second direction (Y), and the surface portion (401) has a curved shape as the outer surface of the cylinder.

[0101] Additionally, when the above transfer roller (400) performs the picking, it rotates on the upper surface of the transfer substrate (200), and when the above transfer is performed, it rotates on the upper surface of the base substrate (300).

[0102] That is, since the transfer substrate (200) is transported in one direction and the transfer roller (400) performs rotation, if the adhesive force between the transfer roller (400) and the transfer element (810) is smaller than the adhesive force between the transfer substrate (200) and the transfer element (810), the transfer element (810) is naturally picked and attached to the surface portion (401) of the transfer roller (400). Additionally, since the base substrate (300) is also transported in one direction and the transfer roller (400) performs rotation, if the adhesive force between the base substrate (300) and the transfer element (810) is greater than the adhesive force between the transfer roller (400) and the transfer element (810), the transfer element (810) attached to the surface portion (401) of the transfer roller (400) is naturally mounted onto the base substrate (300).

[0103] Of course, although the above example illustrates the transfer substrate (200) and the base substrate (300) being transported in the first direction (X) and the transfer roller (400) rotating, the transfer substrate (200) and the base substrate (300) may be transported simultaneously in the first direction (X) from above by the transfer roller (400) while the transfer substrate (200) and the base substrate (300) are stationary and not transported. That is, the transfer substrate (200), the base substrate (300), and the transfer roller (400) are transported in a relatively single direction, and it is sufficient for the transfer roller (400) to rotate.

[0104] The surface portion (401) of the above transfer roller (400) may be formed of a material having a certain flexibility and a certain adhesive force, such as a stamp, and the adhesive force of the surface portion (401) with the transfer element (810) may be set by considering the adhesive force between the transfer substrate (200) and the base substrate (300) and the transfer element (810).

[0105] Meanwhile, when the transfer roller (400) picks a transfer element (810) from the transfer substrate (200) and when mounting the transfer element (810) onto the base substrate (300), the transfer roller (400) must provide a predetermined pressure to the transfer element (810).

[0106] To this end, the control unit (410) provides a predetermined pressure to the transfer roller (400) as indicated by the arrow. Thus, when picking the transfer element (810) from the transfer roller (400) and when transferring the transfer element (810), stable picking and transfer can be induced through the pressure.

[0107] That is, the transfer roller (400) applies pressure to the transfer element (810) while having a predetermined pressure, and at the same time, the laser is irradiated, thereby weakening the adhesive force between the transfer element (810) and the transfer substrate (200). Thus, the transfer element (810) is picked by the transfer roller (400). If only the laser is irradiated, a shock wave may be generated between the transfer element (810) and the transfer substrate (200), causing the transfer element (810) to shift or be damaged. However, as in this embodiment, by using the transfer roller (400) to apply pressure to the transfer element (810) and simultaneously irradiating the laser and performing picking, problems such as damage or shifting due to the generation of the shock wave can be minimized.

[0108] Furthermore, the control unit (410) may additionally control the rotational speed or transfer of the transfer roller (400).

[0109] As previously explained, in order to pick a transfer element (810) from a transfer substrate (200) at the transfer roller (400), the adhesion force between the surface portion (401) of the transfer roller (400) and the transfer element (810) must be controlled to be greater than the adhesion force between the transfer substrate (200) and the transfer element (810).

[0110] To this end, in the picking process, the laser irradiation unit (500) is controlled to reduce the adhesion force between the transfer element (810) and the transfer substrate (200).

[0111] The laser irradiation unit (500) includes a laser source unit (510) and a scan unit (520). The laser source unit (510) generates a laser and provides it to the scan unit (520), and the laser provided to the scan unit (520) is irradiated onto the transfer element (810). That is, since the transfer element (810) corresponds to a selected element among the elements (800) mounted on the transfer substrate (200), the laser is selectively irradiated only onto the selected transfer element (810) through the scan unit (520). At this time, since both the transfer plate (210) and the transfer substrate (200) are transparent, the laser is provided to the lower surface of the transfer element (810) through the transfer substrate (200).

[0112] Thus, when the laser is applied to the lower surface of the transfer element (810), the adhesive layer formed between the transfer substrate (200) and the transfer element (810) to attach the transfer element (810) to the transfer substrate (200) is ablated by the energy of the laser. As described above, when the adhesive layer is ablated, the adhesion force between the transfer element (810) and the transfer substrate (200) is weakened, and the adhesion force between the surface portion (401) of the transfer roller (400) and the transfer element (810) becomes greater, so that the transfer element (810) is picked to the surface portion (401).

[0113] Meanwhile, unlike the weakening of adhesion caused by ablation due to the energy of the laser, the adhesion may be weakened by inducing the generation of gas in the adhesive layer. Furthermore, the adhesion may be weakened by inducing a local volume change in the adhesive layer through irradiation with the laser.

[0114] On the other hand, the residual element (820) that is not irradiated by the laser and thus does not undergo ablation is not picked to the surface portion (401) because the adhesion force between the residual element (820) and the transfer substrate (200) is still maintained to be greater than the adhesion force between the residual element (820) and the surface portion (401). For such selective picking, the adhesion force between the transfer substrate (200) and the element (800), and the adhesion force between the surface portion (401) of the transfer roller (400) and the element (800) must be pre-set.

[0115] At this time, regarding the selective irradiation, i.e., the scanning method of the transfer element (810) of the scanning unit (520) in the laser irradiation unit (500), the method will be described later.

[0116] Furthermore, when the transfer element (810) is selectively irradiated in the scanning unit (520), the laser irradiation unit (500) may move and perform scanning while the transfer substrate (200) remains fixed, or alternatively, the laser irradiation unit (500) may remain fixed in position while the transfer substrate (200) moves and performs scanning.

[0117] Here, in the case of scanning by the scanning unit (520), it can be performed by scanning in the second direction (Y) for one column along the first direction (X). Accordingly, in the case of relative transfer between the laser irradiation unit (500) and the transfer substrate (200) described above, it may correspond to both relative transfer along the first direction (X) and relative transfer along the second direction (Y).

[0118] In addition, as previously explained, for the transfer element (810) to be transferred from the transfer roller (400) to the base substrate (300), the adhesion force between the base substrate (300) and the transfer element (810) must be controlled to be greater than the adhesion force between the surface portion (401) of the transfer roller (400) and the transfer element (810).

[0119] To this end, in the above transfer process, the transfer element (810) is controlled to be connected to the base substrate (300) through the connection assist unit (600). At this time, the connection assist unit (600) controls the connection by irradiating a laser, just like the laser irradiation unit (500).

[0120] As previously explained, since both the base plate (310) and the base substrate (300) are transparent, the laser irradiated from the connection aid (600) located below the base plate (310) passes through the base substrate (300) and is provided to the transfer element (810).

[0121] That is, the laser is provided as solder located between the transfer element (810) and the base substrate (300). At this time, the solder is formed on the lower surface of the transfer element (810), that is, on the surface facing the outside of the surface portion (401). When the laser is irradiated onto the solder, the solder absorbs the laser energy, heats up, and melts. In particular, if the laser is a laser having a wavelength in the NIR band, for example, a laser having a wavelength of 750 nm to 1,150 nm, the solder is heated and melted more effectively. At this time, the provided light source is not necessarily limited to a laser or to the wavelengths exemplified above; it is sufficient if it can heat and melt the solder.

[0122] As described above, after the solder on the lower surface of the transfer element (810) attached to the surface portion (401) of the transfer roller (400) is melted and then hardened again, the adhesion force between the transfer element (810) and the base substrate (300) increases, and the transfer element (810) is connected to the base substrate (300). At this time, if a pressure in the range of, for example, 0.01 MPa to 10 MPa is provided to the transfer roller (400), the connection is performed more effectively, and the transfer process of the transfer element (810) is performed.

[0123] Meanwhile, although not shown in the illustration, a predetermined solder flux can be applied to the solder of the transfer element (810) using a separate coating or spraying unit, thereby enabling more effective connection between the transfer element (810) and the base substrate (300) through the solder.

[0124] Furthermore, in addition to the solder, an anisotropic conductive film (ACF) or anisotropic conductive paste (ACP) may be formed between the transfer element (810) and the base substrate (300). Accordingly, as the anisotropic conductive film (ACF) or anisotropic conductive paste (ACP) is pressed by the transfer roller (400), the conductive particles inside are pressed to achieve electrical connection. At this time, as thermal energy is transferred through the irradiation of the laser, the polymer material of the ACF or ACP can be cured in a pressed state. Thus, the adhesion force between the transfer element (810) and the base substrate (300) increases, and the transfer element (810) is connected to the base substrate (300).

[0125] Furthermore, although the drawings illustrate the provision of thermal energy by irradiating a laser in connection through the solder, ACF (anisotropic conductive film), or ACP (anisotropic conductive paste), a heater unit that provides separate heat in addition to the laser irradiation may be additionally provided.

[0126] That is, a heater unit may be additionally provided on the base plate (310) on which the transfer roller (400) or the base substrate (300) is located, so that heat energy may be supplied through heating along with heat energy supplied by the laser irradiation. At this time, although the detailed configuration of the heater unit is not illustrated, the heater unit may be located inside or on the rear end side of the transfer roller, and may be formed with a structure in which a transparent electrode is formed in a predetermined pattern inside the base plate to be heated. However, the detailed structure or location of such a heater unit is not limited.

[0127] The first and second alignment units (700, 750) control alignment between the transfer roller (400), the transfer substrate (200), and the base substrate (300). That is, the first alignment unit (700) controls alignment between the transfer roller (400) and the transfer substrate (200), and the second alignment unit (750) controls alignment between the transfer roller (400) and the base substrate (300). In this case, since the transfer element (810) picked by the transfer roller (400) must be transferred to the base substrate (300) as is, the alignment result through the first alignment unit (700) is provided to the second alignment unit (750) as is, so that the alignment state between the transfer substrate (200) and the base substrate (300) is controlled simultaneously.

[0128] At this time, the first alignment unit (700) includes a separate optical member to control the alignment between the transfer roller (400) and the transfer substrate (200). Although not shown, a separate alignment marker may be formed on the transfer roller (400) and the transfer substrate (200) to control the alignment based on this. Furthermore, the direction in which such alignment is performed is not limited to the first direction (X), and alignment in the second and third directions (Y, Z) may also be performed.

[0129] Additionally, the second alignment unit (750) also includes a separate optical element to control alignment between the transfer roller (400) and the base substrate (300), and in this case, a separate alignment marker may be formed on the transfer roller (400) and the base substrate (300) to control alignment based thereon. Furthermore, alignment control through the second alignment unit (750) may also include alignment in the second and third directions (Y, Z) in addition to alignment in the first direction (X).

[0131] Hereinafter, a roll-based transfer method (hereinafter referred to as the transfer method) using the transfer device (10) of FIG. 1 will be described. However, redundant descriptions regarding the content explained in the preceding description of the transfer device (10) will be omitted as much as possible, and the description will focus on the characteristics of the steps of the transfer method.

[0132] FIG. 3 is a flowchart illustrating a roll-based transfer method using the transfer device of FIG. 1. FIG. 4a is a flowchart illustrating a picking step using the transfer roller of FIG. 3, and FIG. 4b is a flowchart illustrating a transfer step using the transfer roller of FIG. 3. FIG. 5 is a process diagram illustrating a picking step using the transfer roller of FIG. 3. FIG. 6 and FIG. 7 are schematic diagrams illustrating examples of laser irradiation through a laser irradiation unit in the picking step of FIG. 5. FIG. 8 is a process diagram illustrating a transfer step using the transfer roller of FIG. 3. FIG. 9 is a process diagram illustrating an example of connection through a connection assist unit in the transfer step of FIG. 8.

[0133] First, referring to FIG. 3, in the transfer method, a plurality of elements (800) are mounted on the transfer substrate (200) (step S10). At this time, the mounting method of the elements (800) is not limited, and the spacing between the elements (800) is sufficient if the laser provided through the laser irradiation unit (500) can be irradiated separately for each individual element, and is not particularly limited.

[0134] Afterwards, referring to FIG. 3, the transfer element (810) among the elements (800) mounted on the transfer substrate (200) is selectively picked using the transfer roller (400) (step S20).

[0135] In the picking step (step S20) of the above-mentioned transfer element (810), first, referring to FIG. 4a, the transfer roller (400) is positioned on the upper part of the transfer substrate (200) (step S21). That is, the transfer substrate (200) is transported so that the transfer roller (400) is positioned on the upper part of the transfer substrate (200).

[0136] Afterwards, referring to FIGS. 4a and FIGS. 5, the transfer roller (400) is rotated on the transfer substrate (200), and a laser is selectively irradiated onto the electronic element (810) (step S22).

[0137] That is, while the surface portion (401) of the transfer roller (400) is in contact with the elements (800) mounted on the transfer substrate (200), the transfer roller (400) is rotated in the direction illustrated by the arrow. At the same time, among the elements (800), a laser is selectively irradiated only on the elements that need to be picked by the transfer roller (400), i.e., the transfer elements (810).

[0138] Thus, as the adhesive force between the transfer element (810) and the transfer substrate (200) is weakened, the transfer element (810) is selectively picked onto the surface portion (401) of the transfer roller (400) (step S23). At this time, as previously described, a predetermined pressure is applied to the transfer roller (400) in a direction toward the transfer elements (810) along with the irradiation of the laser, so that the transfer element (810) can be picked more easily.

[0139] At this time, when a laser is applied to a transfer element (810) among the elements (800) mounted in one row (i.e., one row along the second direction (Y)), the transfer element (810) of that row is picked to the surface portion (401) of the transfer roller (400). Afterward, the transfer roller (400) rotates, and the transfer substrate (200) is transported in the first direction (X), so that the transfer element (810) among the elements (800) mounted in the next row is picked to the surface portion (401).

[0140] That is, for each row in this manner, only the transfer elements (810) are selectively picked to the surface portion (401) through laser irradiation, and the picking step (step S20) for the transfer elements (810) is terminated.

[0141] Meanwhile, referring to FIG. 6, as previously explained, the laser irradiation unit (500) irradiates the laser generated from the laser source unit (510) at an irradiation location selected by the scan unit (520), and selectively irradiates the laser (521) only to the transfer element (810).

[0142] At this time, the scanning unit (520) may be, for example, a rotatable mirror that is rotatable and reflects and provides the laser as illustrated. At this time, if the scanning unit (520) is rotated with the first direction (X) as the axis of rotation as illustrated, the laser (521) provided through the scanning unit (520) may be provided to all elements (800) arranged in a single column along the second direction (Y).

[0143] Accordingly, by irradiating the laser (521) while the scanning unit (520) is rotated at a specific angle, the laser (521) can be selectively irradiated only on the transfer element (810) among the elements (800) arranged in a single column along the second direction (Y). That is, through the selective irradiation of the laser as described above, the adhesion force between the transfer element (810) and the transfer substrate (200) can be weakened.

[0144] However, as shown in FIG. 6, if the scanning unit (520) is configured to irradiate a laser to all elements (800) along the second direction (Y), a laser of uniform energy may not be irradiated to all elements (800) along the second direction (Y).

[0145] Accordingly, referring to FIG. 7, the laser irradiation unit (500) further includes a lens unit (530) to ensure that the energy of the irradiated laser is maintained uniformly at all locations along the second direction (Y). At this time, the lens unit (530) may be designed in various shapes, but may be designed to have a convex shape to induce light refraction only along the second direction (Y), and to be formed with a constant thickness so as not to induce light refraction along the first direction (X). That is, the lens unit (530) may have an elliptical shape as shown in the cross-section. For example, in the elliptical shape, the major axis may be formed to be at least 10 times longer than the minor axis. In addition, the height of the lens unit (530) may have a size similar to the width of contact between the transfer roller (400) and the transfer substrate (200), and may have an overall flat column shape.

[0146] Thus, the refractive index increases from the center outward along the second direction (Y), so that a laser (522) of uniform energy can be irradiated onto all elements (800) provided in the row along the second direction (Y). Through this, the incident angle of the laser can be uniformized through the lens portion (530).

[0147] Of course, the shape of the above-mentioned lens portion (530) can be designed in various ways, and as a result, it is sufficient if a laser (522) of uniform energy can be irradiated onto all elements (800) provided in one row.

[0148] Furthermore, as described above, since the lens unit (530) is additionally provided to control the refraction and energy of the laser, the optical system of the laser irradiation unit (500) that must be provided at the bottom of the transfer substrate (200) can be designed to be minimized, thereby increasing space utilization and minimizing interference with other optical systems while enabling effective control of the laser.

[0149] As described above, as the picking of the transfer elements is performed, the picked transfer elements (810) are positioned at regular intervals on the surface portion (401) of the transfer roller (400), as shown in FIG. 5. At this time, since the transfer roller (400) has a cylindrical shape having a predetermined length in the second direction (Y), although FIG. 5 shows that one transfer element is picked per row, in reality, at least one transfer element is picked per row. Furthermore, the number of transfer elements picked per row along the second direction (Y) and the spacing between the picked transfer elements can also be set in various ways.

[0150] Furthermore, in the picking step (step S20) of the above-mentioned transfer element (810), alignment between the transfer roller (400) and the transfer substrate (200) is performed through the first alignment unit (700). At this time, the first alignment unit (700) may include a first unit (710) that recognizes an alignment marker formed on the transfer substrate (200) and a second unit (720) that recognizes an alignment marker formed on the transfer roller (400), thereby inducing alignment between the transfer substrate (200) and the transfer roller (400).

[0151] Afterwards, referring to FIG. 3, the transfer element (810) picked by the transfer roller (400) is transferred to the base substrate (300) (step S30). Meanwhile, prior to the transfer step (step S30), a step of removing foreign substances contained in the transfer element (810) picked to the surface portion (401) through the cleaning substrate (250) may be performed.

[0152] More specifically, referring to FIG. 4b and FIG. 8, in the transfer step (step S30) of the transfer element (810), first, the transfer roller (400) is positioned on the upper part of the base substrate (300) (step S31). That is, the base substrate (300) is transported so that the transfer roller (400) is positioned on the upper part of the base substrate (300).

[0153] Afterward, the transfer roller (400) is rotated on the base substrate (300), and the transfer element (810) is mounted on the base substrate (300) (step S32). Along with this mounting, the base substrate (300) is irradiated with a laser from below to connect the transfer element (810) to the base substrate (300) (step S33).

[0154] That is, as illustrated, transfer elements (810) are attached to the surface portion (401) of the transfer roller (400) at a predetermined interval, and all transfer elements attached to the surface portion (401) of the transfer roller (400) must be transferred to the base substrate (300).

[0155] At this time, since the transfer elements (810) picked at each row are attached at regular intervals along the rotation direction of the transfer roller (400) on the surface portion (401), the transfer elements (810) picked at each row are transferred to the base substrate (300) for each row. That is, as previously explained, since the structure of the cross-section is merely illustrated through FIG. 8, although FIG. 8 exemplifies that one transfer element is attached at each row, at least one transfer element (810) is attached along the second direction (Y) with a predetermined spacing between them.

[0156] Accordingly, while rotating the transfer roller (400) at a constant angle, each row of transfer elements (810) is sequentially transferred to the base substrate (300). At this time, alignment between the transfer roller (400) and the base substrate (300) can be performed through the second alignment unit (750), and the second alignment unit (750) includes a plurality of units as in the first alignment unit (700) mentioned above, and aligns them using alignment markers formed on the transfer roller (400) and the base substrate (300), respectively.

[0157] Meanwhile, referring to FIG. 9, a laser is irradiated from the connection assist unit (600) toward the transfer element (810), thereby transferring the transfer element (810) to the base substrate (300).

[0158] At this time, the laser irradiated from the connection assisting part (600) melts the solder of the transfer element (810) attached to the transfer roller (400) as previously described, and induces a connection between the transfer element (810) and the base substrate (300).

[0159] In addition, the connection assist unit (600) can also be controlled to include a scanning unit so that the laser is irradiated only to the location where the transfer element (810) is located, as described with reference to FIGS. 6 and 7. At this time, since the transfer element (810) is selectively attached only to specific locations along the second direction (Y) in a single row, the laser is irradiated only to the location where the transfer element (810) is attached through the control of the scanning unit. Thus, the transfer element (810) can be selectively transferred to the base substrate (300) while minimizing damage to the surface portion (401) of the transfer roller (400).

[0160] As described above, the transfer of the transfer element (810) to the base substrate (300) is terminated (step S30). Meanwhile, the transfer method is terminated through this step.

[0161] However, using the base substrate (300) on which the element produced through the above transfer method is mounted, it is possible to additionally produce a display panel (900) (step S40). In particular, if the element (810) is an electronic element such as an LED, a driving unit and a wiring unit for driving the LED can be formed as an additional process on the base substrate (300) on which the LED is mounted with a predetermined pitch. Thus, a display panel (900) including the LED can be produced (step S40). Of course, it is obvious that the electronic element can be various elements other than an LED.

[0162] FIGS. 10a and FIGS. 10b are plan views illustrating examples of pixel portions of a display panel manufactured using the transfer device of FIG. 1.

[0163] Referring to FIG. 10a, after transferring an LED onto the base substrate (300) using the transfer method described above, a display panel (900) can be manufactured.

[0164] In one pixel area of ​​the above-mentioned display panel (900), as shown in FIG. 10a, a plurality of LEDs (810) may be formed spaced apart from each other with a predetermined pitch (A1). At this time, if the LEDs (810) are all LEDs that display the same color, the LEDs may be selected and transferred so that they have the same pitch (A1) through the aforementioned transfer method, thereby forming one pixel area of ​​the above-mentioned display panel (900).

[0165] That is, from the transfer board (200) on which LEDs of the same color are mounted with relatively narrow spacing, only LEDs having the preset pitch (A1) are picked and transferred, thereby enabling the production of a display panel (900) in which LEDs (810) having a predetermined pitch (A1) are arranged in one column.

[0166] Additionally, referring to FIG. 10b, an LED array can be configured that has a pitch (A2) different from the pitch (A1) in FIG. 10a in the first direction (X), and another pitch (A3) in the second direction (Y).

[0167] That is, from the transfer substrate (200) in which LEDs of the same color as in FIG. 10a are mounted with relatively narrow spacing, only LEDs having different preset pitches (A2, A3) in the first and second directions are picked and transferred, thereby producing a display panel (901) in which LEDs (810) having a predetermined arrangement on a plane are arranged in one column.

[0168] As described above, since a base substrate or display panel having different arrangements and mounted elements can be manufactured from a single transfer substrate (200), design flexibility is improved and it is possible to manufacture a display panel having pixels that meet the user's requirements.

[0169] FIGS. 11a to 11c are plan views illustrating examples of display panels manufactured using the transfer device of FIG. 1.

[0170] That is, as shown in FIGS. 11a to 11c, the display panels (902, 903, 904) can be manufactured by additionally forming horizontal and vertical wiring sections (911, 912) and a driving section (not shown) on the base substrate (300) on which the elements (810) are mounted through the transfer method.

[0171] At this time, in the case of the display panels (902, 903, 904), as illustrated, the number of elements (810) distributed in the same area is different, and thereby the pixel density of each display panel (902, 903, 904) is formed differently. Furthermore, the elements (810) mounted on each of the display panels (902, 903, 904) are all picked from the same transfer substrate (200).

[0172] Ultimately, by varying the number and arrangement of the transfer elements (810) that are picked and transferred from the same transfer substrate (200) on which the elements (800) are mounted and which has a relatively high density, the pixel density of the finally produced display panels (902, 903, 904) can be varied.

[0173] FIG. 12 is a schematic diagram illustrating another example of a display panel manufactured using the transfer device of FIG. 1.

[0174] Furthermore, if a technology in which pixel densities are configured differently as in FIG. 11a to FIG. 11c is applied to a single display panel (905), it is also possible to manufacture a display panel in which pixel densities are configured differently for each region as in FIG. 12.

[0175] Referring to Fig. 12, the eye (950) is generally divided into a near peripheral area, a mid peripheral area, and a far peripheral area, and in particular, the near peripheral area has a higher concentration and perceives vision.

[0176] Accordingly, considering the viewing characteristics of the user's eye (950), pixels can be configured with different densities for each area in a single display panel (905). That is, as shown in FIG. 12, the display panel can be configured with a high-resolution area (961) having the highest pixel density in the near peripheral area of ​​the eye (950), and with a low-resolution area (963) having the lowest pixel density in the far peripheral area of ​​the eye (950).

[0177] Furthermore, in the mid peripheral area of ​​the eye (950), the display panel can be configured as a medium-resolution area (962) having a pixel density between that of the high-resolution area (961) and the low-resolution area (963).

[0178] Thus, even for a single display panel (905), the pixel density can be configured differently for each region. In particular, when manufacturing a display panel having different pixel densities for each region, the transfer method described above can be applied to improve process efficiency. That is, when picking a transfer element (810) from a single transfer substrate (200) having the same density, the transfer element is picked and then transferred with different pitches for each region corresponding to the high resolution, medium resolution, and low resolution regions. Thus, through a single picking and transfer process, the transfer element can be mounted on the base substrate (300) with different densities for each region corresponding to the high resolution, medium resolution, and low resolution regions.

[0179] FIG. 13 is a process diagram illustrating the picking and transfer steps using a transfer roller in a roll-based transfer method according to another embodiment using the transfer device of FIG. 1.

[0180] In the transfer method of the present embodiment, except for performing the transfer of a transfer element from a plurality of transfer substrates to a single base substrate, it is substantially the same as the transfer method of FIG. 3; therefore, the same reference numbers are used for the same components and redundant descriptions are omitted.

[0181] Referring to FIG. 13, in the transfer method of the present embodiment, transfer elements (810, 811, 812) are picked and transferred from a plurality of transfer substrates (200, 201, 202) to a single base substrate (300).

[0182] That is, in the picking step (step S20) of the transfer element using the transfer roller (400), first, only the first transfer elements (810) are picked from the first elements (800) mounted on the first transfer substrate (200). Afterwards, in the transfer step (step S30) of the transfer element using the transfer roller (400), the picked first transfer elements (810) are transferred to the base substrate (300).

[0183] Afterward, using the transfer roller (400), only the second transfer elements (811) are picked from the second elements (801) mounted on the second transfer substrate (201), and the picked second transfer elements (811) are transferred to the base substrate (300). At this time, the base substrate (300) on which the second transfer elements (811) are transferred is in a state where the first transfer elements (810) have already been transferred, and therefore, the second transfer elements (811) must be transferred to a different location that does not overlap with the location where the first transfer elements (810) are mounted.

[0184] Afterwards, using the transfer roller (400), only the third transfer elements (812) are picked from the third elements (802) mounted on the third transfer substrate (202), and the picked third transfer elements (812) are transferred to the base substrate (300). At this time, the base substrate (300) on which the third transfer elements (812) are transferred is in a state where the first and second transfer elements (810, 811) have already been transferred, and the third transfer elements (812) must be transferred to a different location that does not overlap with the location where the first and second transfer elements (810, 811) are mounted.

[0185] Furthermore, a fourth transfer element may be additionally picked from a fourth transfer substrate and transferred, and the number of transfer substrates picking the transfer element is not limited.

[0186] In particular, in the case of the above transfer method, if the first element (800) mounted on the first transfer substrate (200) is an R (red) LED, the second element (801) mounted on the second transfer substrate (201) is a G (green) LED, and the third element (802) mounted on the third transfer substrate (202) is a B (blue) LED, it is effective when manufacturing a base substrate (300) in which R / G / B LEDs are arranged. That is, the R LED, G LED, and B LED can be individually picked and transferred from transfer substrates in which the R / G / B LEDs are arranged, so that the R / G / B LEDs are finally arranged in a predetermined arrangement on the base substrate (300). Through this, by simply performing three consecutive picking and transfer processes, it is possible to produce a base substrate (300) with R / G / B LEDs arranged in a predetermined pattern, and thus, it is possible to easily produce a display panel with R / G / B LEDs arranged in a predetermined pattern.

[0187] FIG. 14 is a process diagram illustrating the step of performing alignment in a roll-based transfer method according to another embodiment using the transfer device of FIG. 1.

[0188] In the above-described transfer method in this embodiment, except for forming an alignment marker through an additional alignment unit (701), it is substantially the same as the transfer method of FIG. 3; therefore, the same reference numbers are used for identical components and redundant descriptions are omitted.

[0189] Referring to FIG. 14, in the transfer method of the present embodiment, a predetermined alignment marker can be formed on the surface portion (401) of the transfer roller (400) through the additional alignment portion (701). At this time, the additional alignment portion (701) can form the alignment marker on the surface portion (401) by, for example, irradiating a laser, and the laser can be irradiated from the bottom of the transfer plate (210).

[0190] Accordingly, the alignment marker is directly formed on the surface portion (401) of the transfer roller (400), and in particular, by forming the alignment marker before positioning the transfer roller (400) on the upper part of the transfer substrate (200), alignment with the alignment marker formed on the transfer substrate (200) can be performed more accurately.

[0191] Furthermore, the alignment marker formed on the surface portion (401) of the transfer roller (400) can be used for alignment with the alignment marker formed on the base substrate (300) in addition to alignment with the transfer substrate (200).

[0192] Meanwhile, although not illustrated, in addition to forming the alignment marker on the surface portion (410) of the transfer roller (400), the alignment marker may also be formed on the picked electronic element after selectively picking the transfer element. Thus, alignment may be performed with the alignment marker formed on the base substrate (300) based on the alignment marker formed on the picked electronic element.

[0193] At this time, the alignment between the alignment markers is controlled through the first and second alignment units (700, 750), as previously described.

[0194] FIG. 15 is a process diagram illustrating the step of performing cleaning in a roll-based transfer method according to another embodiment using the transfer device of FIG. 1.

[0195] In the transfer method of this embodiment, except for removing foreign substances from the transfer element (810) through the removal unit (450), it is substantially the same as the transfer method of FIG. 3, so the same reference numbers are used for the same components and redundant descriptions are omitted.

[0196] Referring to FIG. 15, in the transfer method of the present embodiment, a predetermined cleaning is performed on the transfer element (810) picked by the surface portion (401) of the transfer roller (400) through the removal unit (450). Generally, the transfer element (810) picked by the transfer roller (400) is picked from the transfer substrate (200), and foreign substances such as the polymer adhesive layer used during mounting on the transfer substrate (200) may remain.

[0197] Accordingly, the removal unit (450) is positioned adjacent to the surface portion (401) to perform cleaning operations, such as removing foreign substances, on the transfer element (810) picked to the surface portion (401). This cleaning operation can be performed separately from the cleaning operation through the cleaning substrate (250) described above, and if cleaning is performed through the removal unit (450), the cleaning operation through the cleaning substrate (250) can be omitted.

[0198] The above removal unit (450) can, for example, remove foreign substances contained in the transfer element (810) by irradiating plasma (451), and while the above removal unit (450) is fixed, the transfer roller (400) can rotate to perform uniform removal of foreign substances on all transfer elements (810) picked on the surface portion (401).

[0199] FIG. 16 is a block diagram illustrating a roll-based transfer device according to another embodiment of the present invention.

[0200] The transfer device (11) according to the present embodiment is substantially the same as the transfer device (10) described with reference to FIG. 1, except that it is equipped with a second laser irradiation unit (601). Therefore, the same reference numbers are used for identical components and redundant descriptions are omitted.

[0201] Referring to FIG. 16, the transfer device (11) according to the present embodiment includes a second laser irradiation unit (601) in place of the connection assist unit (600). Additionally, the laser irradiation unit (500) described in FIG. 1 of the transfer device (10) is named the first laser irradiation unit for convenience of explanation.

[0202] However, the above second laser irradiation unit (601) may substantially include the same configuration as the connection assist unit (600) in FIG. 1, but since it also induces picking in addition to assisting connection, it is described as a laser irradiation unit.

[0203] As described above, the transfer device (11) in this embodiment performs substantially the same function as the transfer device (10) described above, except that the names of the first and second laser irradiation units (600, 601) are different.

[0204] However, in this embodiment, the transfer device (11) performs not only picking and transferring the transfer element but also repairing the defective element, and is described in detail together with the repair method described below.

[0205] FIG. 17 is a flowchart illustrating a roll-based repair method using the transfer device of FIG. 16. FIG. 18 is a flowchart illustrating a step of removing a defective component using the transfer roller of FIG. 17. FIG. 19 is a process diagram illustrating a step of removing a defective component using the transfer roller of FIG. 17. FIG. 20 is a process diagram illustrating a step of transferring a component to the location of a defective component using the transfer roller of FIG. 17.

[0206] Referring to FIGS. 16 and 17, in a repair method using the transfer device (11), first, a defective element (850) is selected from the base substrate (300) on which the transfer element (810) has been transferred (step S50). At this time, the transfer element (810) has already been transferred onto the base substrate (300) through the transfer method described above with reference to FIG. 3, and power is provided to the transfer elements (810) transferred onto the base substrate (300) to induce the transfer elements (810) to light up.

[0207] Thus, among the transferred elements (810) transferred to the base substrate (300), defective elements (850) that do not induce lighting are selected. Of course, the method of selecting these defective elements (850) is not limited to inducing lighting, and various methods for identifying defective elements may be applied.

[0208] Afterwards, referring to FIGS. 16 and 17, when the defective element (850) is selected, the defective element (850) is removed from the base substrate (300) using the transfer roller (400) (step S60).

[0209] More specifically, referring to FIGS. 18 and FIGS. 19 simultaneously, in the step of removing the defective element (850) (step S60), first, the transfer roller (400) is positioned on the upper part of the base substrate (300) (step S61).

[0210] At this time, the transfer roller (400) may be a roller that has transferred the transfer element (810) to the base substrate (300) through the preceding process, but may be a separate transfer roller if the repair process is performed separately.

[0211] Accordingly, the base substrate (300) is transferred, and the transfer roller (400) is positioned on the base substrate (300).

[0212] Afterwards, the transfer roller (400) is rotated on the base substrate (300) and a laser is irradiated onto the defective element (850) (step S62), thereby selectively picking, i.e., removing, only the defective element (850) onto the surface (401) of the transfer roller (400) (step S63).

[0213] The transfer elements (810) transferred onto the base substrate (300) are mounted in a specific location in a plurality of rows, and some of the transfer elements (810) are identified as defective elements (850).

[0214] Accordingly, among the transfer elements of the base substrate (300), only the elements identified as defective elements (850) must be picked to the surface portion (401) of the transfer roller (400).

[0215] Accordingly, the second laser irradiation unit (601) irradiates a laser toward the elements identified as the defective elements (850), and through this laser irradiation, the solder connected between the defective elements (850) and the base substrate (300) is heated and melted again. Accordingly, when the solder is in a melted state and the adhesive force between the defective elements (850) and the base substrate (300) weakens, the transfer roller (400) applies a predetermined pressure and picks the defective elements (850) to the surface portion (401).

[0216] When irradiating with such a laser, the laser must be irradiated simultaneously with the transfer roller (400) pressing the defective element (850). Through this, as previously explained, problems such as damage or displacement of the defective element (850) resulting from simply irradiating with a laser can be prevented in advance by using the transfer roller (400) for pressing.

[0217] To this end, the adhesion force between the surface portion (401) and the defective element (850) must be set to be greater than the adhesion force between the defective element (850) and the base substrate (300) when the solder is melted.

[0218] Meanwhile, the laser provided to the defective element (850) through the second laser irradiation unit (601) may also be a so-called NIR band laser capable of effective heating and melting of the solder, as previously explained. Furthermore, the second laser irradiation unit (601) may also include a scanning unit, as described with reference to FIGS. 6 and 7, to control the laser so that it is irradiated only to the location where the defective element (850) is located. Thus, the defective element (850) can be selectively transferred to the transfer roller (400) while minimizing damage to other normal elements of the base substrate (300).

[0219] As described above, the picking of the defective element (850) to the transfer roller (400) is terminated (step S60). Additionally, although not illustrated, the defective element (850) picked in this manner is removed to the outside, and no separate element is attached to the surface portion (401) of the transfer roller (400).

[0220] Afterwards, referring to FIGS. 16 and 17, a component at a location corresponding to where the defective component (850) was removed is selectively picked from the transfer substrate (200) (step S70). That is, after moving the transfer roller (400) to the upper part of the transfer substrate (200), a specific component among the components (800) mounted on the transfer substrate (200) is selectively picked, just as in the picking step (step S20) of FIG. 3 above.

[0221] At this time, the element being picked must be an element mounted at a location on the transfer substrate (200) that is identical (or corresponding) to the location on the base substrate (300) where the defective element (850) was removed.

[0222] Thus, a laser is irradiated through the first laser irradiation unit (500) onto the transfer element (810) mounted at the corresponding location, and the transfer element (810) is picked onto the surface portion (401) of the transfer roller (400).

[0223] Afterwards, referring to FIGS. 16, 17 and 20, the transfer element (810) picked by the surface portion (401) of the transfer roller (400) is transferred to the location on the base substrate (300) where the defective element (850) has been removed (step S80). At this time, the process of transferring the transfer element (810) to the base substrate (300) is substantially the same as the transfer step (step S30) of FIG. 3.

[0224] In this case, the second laser irradiation unit (601) performs substantially the same role as the connection assist unit (600) described above and assists in transferring the transfer element (810) to the same location as where the defective element (850) was removed.

[0225] As described above, the removal of defective components, picking of new components, and transfer can be performed through a single transfer roller (400), and this repair process can be performed quickly and effectively through the single transfer roller (400) and the one-way driving of the transfer unit.

[0226] Afterwards, as shown in FIG. 17, a display panel can be manufactured in the same manner as the display panel manufacturing step (step S40) of FIG. 3 above using the base substrate (300) in which the defective element has been repaired into a normal element (step S90).

[0227] According to the embodiments of the present invention as described above, by selectively transferring some of the elements mounted on the transfer substrate to the base substrate, the transferred elements mounted on the base substrate are formed with predetermined spacing or a predetermined pattern, thereby enabling the production of a display panel in which electronic elements such as LEDs are formed with various patterns and spacings. In this case, in addition to the display panel, it may be possible to produce various electronic devices in which a plurality of photodiode elements, biosensors, MLCCs, etc. are formed in an array.

[0228] That is, by selectively transferring some of the elements among those densely arranged at a specific pitch on a transfer substrate, the elements mounted on the base substrate can be arranged to have various pitches different from the pitch of the densely arranged elements, thereby enabling the fabrication of various electronic devices including display panels having various patterns and spacings.

[0229] For example, in the case of a display panel manufactured as described above, the pitch between subpixels on which LEDs are mounted can be varied. Furthermore, by implementing a process of individually picking and mounting LEDs—that is, a process of selectively picking different elements mounted on multiple transfer substrates and mounting them on a single base substrate—it is possible to manufacture a display panel in which LEDs are arranged with a predetermined pitch relative to each other.

[0230] Furthermore, display panels with various pixel densities can be manufactured through a single process; in particular, considering the user's field of view, it is possible to produce a single display panel that has a higher pixel density in the central field of view and a lower pixel density in the peripheral field of view. Through this, it is possible to produce various display panels tailored to diverse user requirements or manufacturing environments.

[0231] Meanwhile, picking from the transfer substrate and transfer to the base substrate are performed sequentially by a single transfer roller, and the transfer roller has a cylindrical roller shape with a circular or fan-shaped cross-section, such as in a roll-to-roll or roll-to-plate process, and rotates on the transfer substrate and the base substrate to continuously perform picking and transfer, thereby improving the speed, efficiency, and precision of the manufacturing process of the display panel through the transfer process.

[0232] In addition, when picking from the transfer substrate, a laser is irradiated to weaken the adhesion between the device and the transfer substrate (ablation), thereby inducing the device mounted on the transfer substrate to be picked more easily by the transfer roller. At this time, since the laser must be selectively irradiated only toward the device to be picked, the laser irradiation unit may include a separate scanning unit to selectively scan only the device to be transferred among the devices mounted on the transfer substrate, thereby weakening the adhesion. Thus, even when the transfer roller contacts and rotates along the upper surface of all devices mounted on the transfer substrate, only the devices scanned by the scanning unit can be selectively picked. Furthermore, although the position of the device may be misaligned or the device may be damaged when the laser is irradiated, irradiating the laser while the transfer roller is under pressure allows the roller's soft stamp to fix the position of the device and absorb the impact caused by the laser pulse, thereby reducing device damage.

[0233] In addition, when transferring a device from the transfer roller to the base substrate, in order to strengthen the adhesion between the device and the base substrate, the solder, anisotropic conductive film (ACF), or anisotropic conductive paste (ACP) formed on the lower part of the device can be induced to adhere (solder) through laser irradiation. By doing so, the adhesion between the device and the base substrate is formed to be higher than the adhesion between the transfer roller and the device, thereby allowing all devices picked by the transfer roller to be transferred to the base substrate with high reliability.

[0234] At this time, when performing the connection through the melting of the solder, by maintaining the wavelength of the irradiated laser in a wavelength band with high transmittance on the base substrate, for example, the NIR band, energy absorption on the base substrate is minimized, and the energy absorption of the solder and the resulting heating and melting are performed more effectively, thereby enabling a more stable connection between the device and the base substrate with high reliability.

[0235] In the above-mentioned picking and transfer process, a separate pressure is applied to the transfer roller, thereby enabling accurate picking and transfer of the selected element.

[0236] Furthermore, in the picking and transfer process described above, alignment between the transfer substrate and the transfer roller, as well as alignment between the transfer roller and the base substrate, are both important, and thus, the alignment can be accurately induced in the repetitive process through the alignment units. Meanwhile, by separately forming an alignment marker on the transfer roller through an additional alignment unit, more accurate alignment can be performed in the picking and transfer process using the alignment marker.

[0237] In addition, since residue may exist during the process of transferring the device picked by the transfer roller from the transfer substrate, cleaning of the device can be performed by performing plasma treatment through a removal unit, thereby improving the electrical stability of the device finally transferred to the base substrate.

[0238] Furthermore, by using the roll-based transfer device described above to perform repair of defective components, it is possible to manufacture display panels with varying pixel pitches using a single transfer device, as well as simultaneously perform a repair process to replace defective components on the display panel, thereby improving process efficiency and convenience.

[0239] That is, among the components mounted on the base substrate, defective components can be picked out and removed externally using the transfer roller, and the repair process can be performed by transferring normal components back to the area where the defective components were removed through the transfer method described above.

[0240] In this case, when picking a defective component from the base substrate, selective picking of the defective component can be performed by irradiating a laser between the defective component and the base substrate to melt the solder and induce picking of the defective component. At this time, the irradiated laser may be, for example, in the NIR band, which can similarly perform melting of the solder more effectively.

[0241] In particular, by using a single transfer roller, defective components can be picked and removed, and new good components can be re-transferred more accurately and quickly, thereby improving the speed and efficiency of the repair process. That is, it is sufficient for the transfer roller to be pressed and rotated on the transfer substrate and the base substrate, and by selecting the position of the laser being irradiated, defective components are picked and removed and new components are picked and transferred, thereby improving the efficiency and speed of the process.

[0242] Although the present invention has been described above with reference to preferred embodiments, those skilled in the art will understand that various modifications and changes can be made to the invention without departing from the spirit and scope of the invention as set forth in the following claims. Explanation of the symbols

[0243] 10, 11: Roll-based transfer device 100 : Transfer section 200, 201, 202: Transfer board 210 : Transfer Plate 250 : Cleaning board 300 : Base substrate 310 : Base Plate 400 : Transfer roller 401 : Surface 410 : Control unit 450 : Removal unit 500, 601: Laser irradiation unit 510: Laser source section 520 : Scan section 521, 522: Laser 530 : Lens part 600 : Connection auxiliary part 700, 750 : Alignment section 701 : Additional alignment section 800, 801, 802 : Device 810, 811, 812 : Transfer element 820, 821, 822 : Residual elements 850 : Defective component 900, 901, 902, 903, 904, 905 : Display panel 961 : High-resolution area 962 : Medium resolution area 963 : Low resolution area

Claims

Claim 1 A roll-based repair method comprising: a step of selecting defective elements from a base substrate on which elements have been transferred; a step of removing the defective elements from the base substrate using a transfer roller; a step of selectively picking transfer elements among elements mounted on the transfer substrate using the transfer roller; and a step of transferring the transfer elements of the transfer roller to the location of the defective elements on the base substrate. Claim 2 A roll-based repair method according to claim 1, characterized in that, in the step of selecting the defective elements, power is provided to the elements transferred to the base substrate to induce lighting. Claim 3 A roll-based repair method according to claim 1, characterized in that, in the step of removing the defective element, the step of positioning the transfer roller on the upper part of the base substrate; the step of pressing and rotating the transfer roller on the base substrate and irradiating the defective element with a laser; and the step of picking only the defective element onto the surface of the transfer roller. Claim 4 A roll-based repair method according to claim 3, characterized in that, in the step of irradiating a laser onto the defective element, the laser is irradiated onto the solder, anisotropic conductive film (ACF), or anisotropic conductive paste (ACP) between the defective element and the base substrate. Claim 5 A roll-based repair method according to claim 4, wherein the base substrate transmits the laser, and the laser is a laser in the NIR band that penetrates the base substrate and is irradiated. Claim 6 A roll-based repair method according to claim 1, wherein the step of selectively picking the transfer element is characterized by picking the element corresponding to the location of the defective element among the elements mounted on the transfer substrate as the transfer element. Claim 7 A roll-based repair method according to claim 6, wherein the step of selectively picking the transfer element comprises: positioning the transfer roller on the upper part of the transfer substrate; pressing and rotating the transfer roller on the transfer substrate and irradiating the transfer element with a laser; and picking only the transfer element onto the surface portion of the transfer roller. Claim 8 A roll-based repair method according to claim 1, wherein the step of transferring the transfer element comprises: positioning the transfer roller on the upper part of the base substrate; pressing and rotating the transfer roller on the base substrate to mount the transfer element at the location of the defective element on the base substrate; and connecting the base substrate and the transfer element. Claim 9 A roll-based repair method according to claim 8, characterized in that, in the step of connecting the base substrate and the transfer element, as the laser is irradiated, the solder between the transfer element and the base substrate is melted and the transfer element and the base substrate are connected to each other. Claim 10 A roll-based repair method according to claim 9, characterized by coating a solder flux on the surface of the solder prior to the step of connecting the base substrate and the transfer element.

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