Light emitting diode transfer method and method for manufacturing display device using the same

Abstract

A light emitting diode transfer method and a method for manufacturing a display device using the method are disclosed. The light emitting diode (LED) transfer method according to an exemplary embodiment of the present disclosure includes: bonding a flexible substrate and a rigid substrate formed with a plurality of light emitting diodes; transferring the plurality of light emitting diodes to the flexible substrate; and separating the rigid substrate and the flexible substrate, wherein separating the rigid substrate and the flexible substrate includes: separating the rigid substrate and the flexible substrate in a state where one surface of the rigid substrate is fixed and a portion of the outermost portion of the flexible substrate is fixed by a fixing member. Therefore, the transfer defects of the plurality of light emitting diodes can be reduced by separating the flexible substrate and the rigid substrate in a row-by-row separation method.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of and priority to Korean Patent Application No. 10-2020-0166705 filed in Korea on December 2, 2020, which is hereby expressly incorporated by reference into this application in its entirety. Technical Field

[0003] The present disclosure relates to a light emitting diode (LED) transfer method and a method for manufacturing a display device using the same, and more particularly, to an LED transfer method for improving yield when transferring a plurality of LEDs and a method for manufacturing a display device using the same. Background Art

[0004] Display devices used in computer monitors, TVs, and mobile phones include organic light emitting displays (OLEDs) that emit light by themselves and liquid crystal displays (LCDs) that require a separate light source.

[0005] Such display devices are being applied to more and more various fields including not only computer monitors and TVs but also personal mobile devices, and thus, display devices having reduced volume and weight while having a wide display area are being studied.

[0006] In recent years, a display device including a light emitting diode (LED) has attracted attention as a next-generation display device. Since LED is formed of an inorganic material rather than an organic material, it has excellent reliability and has a longer life than a liquid crystal display or an organic light emitting display. In addition, LED has a high light emission speed, high light emission efficiency, and excellent stability due to high impact resistance, and can display high-brightness images. Summary of the invention

[0007] Accordingly, embodiments of the present disclosure are directed to a light emitting diode (LED) transferring method and a method of manufacturing a display device using the same that substantially obviate one or more problems due to limitations and disadvantages of the related art.

[0008] An aspect of the present disclosure is to provide a light emitting diode (LED) transfer method for reducing defects of a plurality of light emitting diodes during a transfer process of transferring the plurality of light emitting diodes from a wafer to a donor substrate and a method of manufacturing a display device using the same.

[0009] Another aspect of the present disclosure is to provide an LED transfer method having improved alignment accuracy of a plurality of light emitting diodes and a method of manufacturing a display device using the same.

[0010] Still another aspect of the present disclosure is to provide an LED transfer method for reducing process time by increasing separation speed of a wafer and a donor substrate and a method of manufacturing a display device using the same.

[0011] Still another aspect of the present disclosure is to provide an LED transfer method that minimizes deformation of a plurality of light emitting diodes when a wafer and a donor substrate or a donor substrate and a display panel are separated, and a method of manufacturing a display device using the same.

[0012] Additional features and aspects will be set forth in the description that follows, and will be partially apparent from the description, or may be learned by the practice of the inventive concepts provided herein. Other features and aspects of the inventive concepts may be realized and obtained by the structures particularly pointed out in the written description, or may be derived from the written description, its claims, and the accompanying drawings.

[0013] To achieve these and other aspects of the inventive concept, as embodied and broadly described herein, a light emitting diode (LED) transfer method includes: bonding a flexible substrate and a rigid substrate formed with a plurality of light emitting diodes; transferring the plurality of light emitting diodes to the flexible substrate; and separating the rigid substrate and the flexible substrate, wherein separating the rigid substrate and the flexible substrate includes: separating the rigid substrate and the flexible substrate in a state where one surface of the rigid substrate is fixed and a portion of the outermost portion of the flexible substrate is fixed by a fixing member. Therefore, transfer defects of the plurality of light emitting diodes can be reduced by separating the flexible substrate and the rigid substrate in a row-by-row separation method.

[0014] In another aspect, a method for manufacturing a display device includes: bonding a wafer and a donor substrate; transferring a plurality of light-emitting diodes of the wafer to the donor substrate; separating the wafer and the donor substrate; bonding a display panel and a donor substrate provided with a plurality of light-emitting diodes; transferring a plurality of light-emitting diodes of the donor substrate to the display panel; and separating the display panel and the donor substrate, wherein separating the wafer and the donor substrate includes: separating the wafer and the donor substrate in a state where one surface of the wafer is fixed to a head and a portion of the outermost portion of the donor substrate is fixed to a platform. Therefore, the wafer and the donor substrate can be separated in a row-by-row separation method by separating the wafer and the donor substrate in a state where only a portion of the outermost portion of the donor substrate is fixed, and the impact of the plurality of light-emitting diodes applied to the donor substrate can be minimized.

[0015] Additional details of exemplary embodiments are included in the detailed description and the accompanying drawings.

[0016] According to the present disclosure, when the donor substrate is separated from the wafer, only one end of the donor substrate is physically fixed, thereby minimizing deformation of a plurality of light emitting diodes on the donor substrate.

[0017] According to the present disclosure, a reduction in transfer yield of a plurality of light emitting diodes can be minimized by separating the donor substrate and the wafer row by row.

[0018] According to the present disclosure, it is possible to reduce process time and cost and improve productivity by increasing the transfer speed of light emitting diodes.

[0019] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the inventive concepts as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this application, illustrate embodiments of the disclosure and together with the description serve to explain various principles.

[0021] Figure 1 is a plan view of a display device according to an exemplary embodiment of the present disclosure.

[0022] Figure 2 is a schematic cross-sectional view of sub-pixels constituting a plurality of pixels of a display device according to an exemplary embodiment of the present disclosure.

[0023] Figure 3 is a process flow chart illustrating a method of manufacturing a display device according to an exemplary embodiment of the present disclosure.

[0024] FIG. 4A to FIG. 4G 1 is a schematic process diagram for explaining an LED transfer method and a method of manufacturing a display device using the same according to an exemplary embodiment of the present disclosure.

[0025] Figure 5A and Figure 5B 2 is a schematic diagram for explaining the LED transfer method according to Comparative Example 1.

[0026] Fig. 6A and Figure 6B Schematic diagram for explaining the LED transfer method according to Comparative Example 2. DETAILED DESCRIPTION

[0027] Advantages and features of the present disclosure and methods of achieving the advantages and features will be described by reference to the following and accompanying drawings. Figure 1 The present disclosure is not limited to the exemplary embodiments disclosed herein, but will be implemented in various forms. The exemplary embodiments are provided only by way of example so that those skilled in the art can fully understand the disclosure of the present disclosure and the scope of the present disclosure. Therefore, the present disclosure will only be limited by the scope of the appended claims.

[0028] The shapes, sizes, ratios, angles, numbers, etc. shown in the accompanying drawings for describing the exemplary embodiments of the present disclosure are merely examples, and the present disclosure is not limited thereto. Throughout the specification, the same reference numerals generally represent the same elements. In addition, in the following description of the present disclosure, the detailed description of known related technologies may be omitted to avoid unnecessarily obscuring the subject matter of the present disclosure. Terms such as "including", "having" and "comprising" used herein are generally intended to allow the addition of other components unless these terms are used together with the term "only". Any reference to a singular form may include a plural form unless otherwise expressly stated.

[0029] Even if not explicitly stated, the components are interpreted as including ordinary error ranges.

[0030] When terms such as "on," "over," "below," and "immediately" are used to describe the positional relationship between two parts, one or more parts may be located between the two components unless these terms are used together with the terms "immediately next to" or "directly."

[0031] When an element or a layer is disposed “on” another element or layer, the other layer or other elements may be directly on the other element or interposed therebetween.

[0032] Although the terms "first", "second", etc. are used to describe various components, these components are not limited by these terms. These terms are only used to distinguish one component from other components. Therefore, the first component to be mentioned below can be the second component in the technical concept of the present disclosure.

[0033] Throughout the specification, like reference numerals generally refer to like elements.

[0034] The size and thickness of each component shown in the drawings are illustrated for convenience of description, and the present disclosure is not limited to the illustrated sizes and thicknesses of the components.

[0035] The features of the various embodiments of the present disclosure may be partially or completely adhered to or combined with each other, and may be interlocked and operated in technically different ways, and the embodiments may be performed independently or in association with each other.

[0036] Hereinafter, an LED transfer method and a method of manufacturing a display device using the same according to exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0037] Figure 1 is a plan view of a display device according to an exemplary embodiment of the present disclosure. Figure 1, for convenience of explanation, only the display panel PN and the plurality of pixels PX are shown among various components of the display device 100.

[0038] The display panel PN is a component that displays an image, and includes a display area AA and a non-display area NA.

[0039] The display panel PN includes a display area AA and a non-display area NA.

[0040] The display area AA is an area for displaying an image. A plurality of pixels PX for displaying an image and a circuit unit for driving the plurality of pixels PX may be provided in the display area AA. The circuit unit may include various thin film transistors, capacitors, and lines for driving the pixels PX. For example, the circuit unit may include various components, such as a driving thin film transistor, a switching thin film transistor, a storage capacitor, a gate line, and a data line, but is not limited thereto.

[0041] The non-display area NA is an area where no image is displayed and is an area where various lines, driver ICs, etc. for driving the pixels PX disposed in the display area AA are disposed. For example, various driver ICs such as gate driver ICs and data driver ICs may be disposed in the non-display area NA.

[0042] Despite Figure 1 2 and 3 , it is shown that the non-display area NA surrounds the display area AA, but the non-display area NA may be an area extending from one side of the display area AA, but is not limited thereto.

[0043] A plurality of pixels PX are arranged in a display area AA of a display panel PN. Each of the plurality of pixels PX may include a plurality of sub-pixels. The plurality of sub-pixels are separate units that emit light, and a light emitting diode (LED) and a driving circuit are formed in each of the plurality of sub-pixels. For example, the plurality of pixels PX may include a red sub-pixel, a green sub-pixel, and a blue sub-pixel, but is not limited thereto, and the plurality of pixels PX may also include a white sub-pixel.

[0044] The light emitting diodes arranged in the plurality of corresponding sub-pixels may be light emitting diodes emitting light of the same color or light emitting diodes emitting light of different colors. For example, when the plurality of corresponding light emitting diodes emit light of different colors, one portion of the plurality of light emitting diodes may be a red light emitting diode emitting red light, another portion of the plurality of light emitting diodes may be a green light emitting diode emitting green light, and the remaining portion of the plurality of light emitting diodes may be a blue light emitting diode emitting blue light. In addition, the combination of light from the red light emitting diode, the green light emitting diode, and the blue light emitting diode may realize light of various colors including white.

[0045] Furthermore, when a plurality of light emitting diodes emit light of the same color, a light conversion member may be provided together with the plurality of light emitting diodes. For example, when the plurality of light emitting diodes are blue light emitting diodes, a red light conversion layer and a green light conversion layer may be provided together in each of the plurality of sub-pixels. However, the type and number of light emitting diodes provided in the plurality of sub-pixels constituting the pixel PX may be configured differently according to the embodiment, but are not limited thereto.

[0046] A plurality of pixels PX may be arranged at equal distances. A plurality of pixels PX may be arranged at the same distance. For example, the distance from the center of one pixel PX among the plurality of pixels PX to the center of another pixel PX adjacent thereto may be a first distance D1. In addition, the first distance D1, that is, the distance between the pixels PX may also be defined as a pixel pitch.

[0047] In the following, reference Figure 2 The plurality of pixels PX are described in more detail.

[0048] Figure 2 is a schematic cross-sectional view of sub-pixels constituting a plurality of pixels of a display device according to an exemplary embodiment of the present disclosure.

[0049] refer to Figure 2 The substrate 110 is a supporting member for supporting other components of the display device 100, and may be formed of an insulating material. For example, the substrate 110 may be formed of glass or resin. In addition, the substrate 110 may be formed of a polymer or plastic, such as polyimide (PI), or may be formed of a material having flexibility.

[0050] The driving transistor 120 is disposed on the substrate 110 of the display panel PN. The driving transistor 120 may be used as a driving element of the display device 100. The driving transistor 120 includes a gate electrode 121, an active layer 122, a source electrode 123, and a drain electrode 124.

[0051] The gate electrode 121 is disposed on the substrate 110. The gate electrode 121 may be formed of a conductive material, for example, copper (Cu), aluminum (Al), molybdenum (Mo), titanium (Ti), or an alloy thereof, but is not limited thereto.

[0052] A gate insulating layer 111 is disposed on the gate electrode 121. The gate insulating layer 111 is a layer for insulating the gate electrode 121 and the active layer 122, and may be formed of an insulating material. For example, the gate insulating layer 111 may be formed of a single layer or multiple layers of silicon oxide (SiOx) or silicon nitride (SiNx), but is not limited thereto.

[0053] An active layer 122 is disposed on the gate insulating layer 111. For example, the active layer 122 may be formed of an oxide semiconductor, amorphous silicon, polysilicon, etc., but is not limited thereto.

[0054] The source electrode 123 and the drain electrode 124 are disposed on the active layer 122 to be spaced apart from each other. The source electrode 123 and the drain electrode 124 may be electrically connected to the active layer 122. The source electrode 123 and the drain electrode 124 may be formed of a conductive material such as copper (Cu), aluminum (Al), molybdenum (Mo), titanium (Ti), or an alloy thereof, but are not limited thereto.

[0055] Meanwhile, in the present disclosure, the driving transistor 120 is illustrated as a driving transistor 120 having a structure in which a gate electrode 121 is disposed at the bottom, an active layer 122 is disposed on the gate electrode 121, and a source electrode 123 and a drain electrode 124 are disposed on the active layer 122, but the present disclosure is not limited thereto.

[0056] A common line CL is disposed on the gate insulating layer 111. The common line CL may transmit common power supplied from the outside to a plurality of light emitting diodes LED of a plurality of sub-pixels. The common line CL may be formed of, for example, the same material as the source electrode 123 and the drain electrode 124 of the driving transistor 120 and may be formed in the same process, but the material and arrangement of the common line CL are not limited thereto.

[0057] A first insulating layer 112 is disposed on the driving transistor 120 and the common line C1. The first insulating layer 112 may be disposed over the driving transistor 120 to protect the driving transistor 120. The first insulating layer 112 may be formed of an organic material such as benzocyclobutene or photoacryl.

[0058] A light emitting diode LED is disposed on the first insulating layer 112. The light emitting diode LED may be an LED or a micro LED formed of an inorganic material. The light emitting diode LED may be electrically connected to the source electrode 123 or the drain electrode 124 of the driving transistor 120 through a contact hole formed in the first insulating layer 112. Figure 2 It is shown that the light emitting diode LED is disposed on the patterned first insulating layer 112 , but the light emitting diode LED may be disposed on the first insulating layer 112 which is not patterned and has a flat upper surface, but is not limited thereto.

[0059] When the plurality of light emitting diodes LED are a plurality of LEDs, they may be formed into various structures such as a lateral type, a vertical type, and a flip chip type. The lateral type LED includes an n-electrode NE and a p-electrode PE, which are horizontally arranged on both sides of the light emitting layer EL. The vertical type LED includes an n-electrode NE and a p-electrode PE, which are arranged above and below the light emitting layer EL. The flip chip type LED has substantially the same structure as the lateral type LED, and the flip chip type LED has a structure in which the n-electrode NE and the p-electrode PE are horizontally arranged below the light emitting layer EL, while the lateral type LED has a structure in which the n-electrode NE and the p-electrode PE are horizontally arranged above the light emitting layer EL. In the following, the description is made assuming that the plurality of light emitting diodes LED are LEDs having a lateral structure, but the type of the plurality of light emitting diodes LED is not limited thereto.

[0060] Meanwhile, the light emitting diode LED may be manufactured by a process separate from the thin film transistor (TFT) array process of the display panel PN. For example, a plurality of light emitting diodes LED may be formed on a wafer formed of a material such as sapphire, and then, the plurality of light emitting diodes LED may be transferred to the display panel PN provided with the driving transistor 120 and various lines.

[0061] The light emitting diode LED includes a p-type semiconductor layer PL, a light emitting layer EL, an n-type semiconductor layer NL, a p-electrode PE, and an n-electrode NE.

[0062] The n-type semiconductor layer NL is disposed on the first insulating layer 112, and the p-type semiconductor layer PL is disposed on the n-type semiconductor layer NL. Each of the p-type semiconductor layer PL and the n-type semiconductor layer NL may be a layer formed by implanting n-type or p-type impurities into gallium nitride (GaN). For example, the p-type semiconductor layer PL may be a layer formed by implanting p-type impurities into gallium nitride, and the n-type semiconductor layer NL may be a layer formed by implanting n-type impurities into gallium nitride, but is not limited thereto. The p-type impurity may be magnesium (Mg), zinc (Zn), beryllium (Be), etc., and the n-type impurity may be silicon (Si), germanium (Ge), tin (Sn), etc., but is not limited thereto.

[0063] The light emitting layer EL is disposed between the p-type semiconductor layer PL and the n-type semiconductor layer NL. The light emitting layer EL may emit light by receiving holes and electrons from the p-type semiconductor layer PL and the n-type semiconductor layer NL. The light emitting layer EL may have a single layer or a multi-quantum well (MQW) structure, for example, the light emitting layer EL may be formed of indium gallium nitride (InGaN) or gallium nitride (GaN), but is not limited thereto.

[0064] The p-electrode PE is disposed on the p-type semiconductor layer PL, and the n-electrode NE is disposed on the n-type semiconductor layer NL. The p-electrode PE may be electrically connected to the p-type semiconductor layer PL, and the n-electrode NE may be electrically connected to the n-type semiconductor layer NL.

[0065] A second insulating layer 113 is disposed on the light emitting diode LED and the first insulating layer 112. The second insulating layer 113 may be disposed on the plurality of light emitting diodes LED to protect the plurality of light emitting diodes LED. The second insulating layer 113 may be formed of an organic material such as benzocyclobutene or photopropylene.

[0066] The first and second connection electrodes CE1 and CE2 are disposed on the second insulating layer 113 .

[0067] The first connection electrode CE1 may electrically connect the driving transistor 120 and the light emitting diode LED through the contact holes in the first insulating layer 112 and the second insulating layer 113. For example, the first connection electrode CE1 may electrically connect the drain electrode 124 of the driving transistor 120 and the p-electrode PE of the light emitting diode LED. The first connection electrode CE1 may be formed of a transparent metal oxide such as indium tin oxide (ITO), indium gallium zinc oxide (IGZO), or indium gallium oxide (IGO), but is not limited thereto.

[0068] The second connection electrode CE2 may electrically connect the common line CL and the light emitting diode LED through the contact hole in the first insulating layer 112 and the second insulating layer 113. For example, the second connection electrode CE2 may electrically connect the common line CL and the n-electrode NE of the light emitting diode LED. The second connection electrode CE2 may be formed of a transparent metal oxide such as indium tin oxide (ITO), indium gallium zinc oxide (IGZO), or indium gallium oxide (IGO), but is not limited thereto.

[0069] A protective layer 114 is disposed on the first connection electrode CE1 and the second connection electrode CE2. The protective layer 114 may be disposed on the entire surface of the display panel PN to protect the plurality of light emitting diodes LED and the circuit including the driving transistor 120 from external impact. The protective layer 114 may be formed of, for example, an optically clear adhesive (OCA) or an optically clear resin (OCR), but is not limited thereto.

[0070] Meanwhile, although not shown in the drawings, a reflective layer may be further provided, and the reflective layer is provided to overlap with the plurality of light emitting diodes LED. The reflective layer is provided to overlap with the plurality of light emitting diodes LED, and may reflect light emitted from the plurality of light emitting diodes LED to the outside of the display device 100, and improve the light emitting efficiency of the display device 100.

[0071] In the following, reference will be made to Figures 3 to 4GAn LED transfer method and a method of manufacturing the display device 100 using the same according to an exemplary embodiment of the present disclosure are described.

[0072] Figure 3 is a process flow chart illustrating a method of manufacturing a display device according to an exemplary embodiment of the present disclosure. FIG. 4A to FIG. 4G is a schematic process diagram for explaining an LED transfer method and a method for manufacturing a display device using the same according to an exemplary embodiment of the present disclosure. Specifically, 4A to 4F is a schematic process diagram for explaining a transfer process, and Figure 4G is a schematic process diagram for explaining the secondary transfer process. Figure 4A is a plan view of the wafer 200, and Figure 4B is a plan view of the donor substrate 300 . Figure 4C is along Figure 4B A cross-sectional view taken along line AA'. Figure 4D and Figure 4E 2 is a schematic cross-sectional view for explaining a separation process of the wafer 200 and the donor substrate 300 , and schematically shows the donor substrate 300 , the wafer 200 , and a plurality of light emitting diodes LED for convenience of explanation. Figure 4F is a plan view of the donor substrate 300 after one transfer process is completed. Figure 4G 2 is a cross-sectional view of a donor substrate 300 and a display panel PN for explaining a secondary transfer process.

[0073] First, refer to Figure 3 , a primary transfer process is performed so that the plurality of light emitting diodes LED on the wafer 200 can be transferred to the donor substrate 300. After the primary transfer process is completed, a secondary transfer process is performed so that the plurality of light emitting diodes LED on the donor substrate 300 can be transferred to the display panel PN. Therefore, the manufacturing process of the display device 100 can be completed by transferring the plurality of light emitting diodes LED from the wafer 200 to the donor substrate 300 and from the donor substrate 300 to the display panel PN.

[0074] In the following, we will first refer to Figure 3 as well as 4A to 4F Describe a transfer process.

[0075] Also refer to Figure 3 and Figure 4A, the wafer 200 is a substrate on which a plurality of light emitting diodes LED are formed. A material such as gallium nitride (GaN) or indium gallium nitride (InGaN) constituting a plurality of light emitting diodes LED is formed on the wafer 200 to grow a crystal layer, the crystal layer is cut into individual chips, and electrodes are formed thereon, thereby forming a plurality of light emitting diodes LED. The wafer 200 may be formed of sapphire, silicon carbide (SiC), gallium nitride (GaN), zinc oxide (ZnO), etc., but is not limited thereto. Since the wafer 200 is formed of a hard material such as sapphire, it may be defined as a rigid substrate.

[0076] In this case, a plurality of light emitting diodes LED emitting the same color of light or a plurality of light emitting diodes LED emitting different colors of light may be formed on one wafer 200. Hereinafter, description is made assuming that a plurality of light emitting diodes LED emitting the same color of light are formed on one wafer 200.

[0077] The wafer 200 includes an active region 200A and an outer region 200B. The active region 200A is a region where a plurality of light emitting diodes LED are formed, and the outer region 200B disposed outside the active region 200A is a region where one or more dams DM and a plurality of alignment keys AK are disposed.

[0078] A plurality of light emitting diodes LED are disposed in the active region 200A. The plurality of light emitting diodes LED may be formed by forming an epitaxial layer on the wafer 200 and then patterning the epitaxial layer. Specifically, the plurality of light emitting diodes LED may be formed by growing a material forming an n-type semiconductor layer NL, a light emitting layer EL, and a p-type semiconductor layer PL constituting the plurality of light emitting diodes LED on the wafer 200 and then patterning them into a plurality (i.e., performing an isolation process).

[0079] A plurality of light emitting diodes LED may be arranged at a second distance D2. The second distance D2 may be a distance from the center of one light emitting diode LED among the plurality of light emitting diodes LED to the center of another light emitting diode LED adjacent thereto. In addition, the second distance D2 may be a distance less than the first distance D1, i.e., a distance between a plurality of pixels PX of the display panel PN.

[0080] The plurality of alignment keys AK provided in the outer region 200B include first and second alignment keys AK1 and AK2. The first and second alignment keys AK1 and AK2 may be provided in the outer region 200B. However, the first and second alignment keys AK1 and AK2 are not limited to those shown in the drawings, and their number and positions may be variously designed.

[0081] The first alignment key AK1 is a member for aligning the wafer 200 and the donor substrate 300. The first alignment key AK1 is a mark for matching alignment and parallelism with the donor substrate 300 when the plurality of light emitting diodes LED of the wafer 200 are transferred to the donor substrate 300. The wafer 200 and the donor substrate 300 may be aligned and parallelized by aligning the first alignment key AK1 of the wafer 200 and the alignment protrusion 332 of the donor substrate 300.

[0082] For example, the first alignment key AK1 may be a metal pattern that is disposed between the plurality of dams DM in the outer region 200B, or formed on the upper portion of the plurality of dams DM or on the lower portion of the plurality of dams DM. Therefore, the wafer 200 and the donor substrate 300 may be aligned by detecting the first alignment key AK1 through a visual method. In this case, even when the first alignment key AK1 is formed on the dam DM to be described later, since the first alignment key AK1 is a metal pattern, a step generated between the wafer 200 and the donor substrate 300 by the first alignment key AK1 may be negligible. Therefore, the first alignment key AK1 may be formed without being limited to the position of the dam DM in the outer region 200B.

[0083] The second alignment key AK2 is a component for aligning the donor substrate 300 and the display panel PN. When the plurality of light emitting diodes LED of the wafer 200 are transferred to the donor substrate 300, the second alignment key AK2 may be transferred to the donor substrate 300 together with the plurality of light emitting diodes LED. Then, by using the second alignment key AK2 on the donor substrate 300, the alignment and parallelism of the donor substrate 300 and the display panel PN may be matched.

[0084] The first alignment key AK1 and the second alignment key AK2 may be formed together when forming the plurality of light emitting diodes LED, or may be formed by a process separate from the process of the plurality of light emitting diodes LED. If the first alignment key AK1 and the second alignment key AK2 are formed together with the plurality of light emitting diodes LED, the first alignment key AK1 and the second alignment key AK2 may be formed of the same material as at least a portion of the material constituting the plurality of light emitting diodes LED. However, the material and the forming process of the first alignment key AK1 and the second alignment key AK2 may be configured differently according to the design, but are not limited thereto.

[0085] The first alignment key AK1 and the second alignment key AK2 may be configured differently in shape and size. In order to identify the first alignment key AK1 and the second alignment key AK2 provided in the outer area 200B, the shapes or sizes of the first alignment key AK1 and the second alignment key AK2 may be configured differently. For example, the size of the first alignment key AK1 may be larger than the size of the second alignment key AK2, but the present disclosure is not limited thereto.

[0086] One or more dams DM are provided in the outer region 200B. The dam DM is a component for improving adhesion with the donor substrate 300 by improving the contact area with the donor substrate 300, which will be described later. One or more dams DM may be formed together with a plurality of light emitting diodes LED. Specifically, one or more dams DM may be formed by retaining a portion of the epitaxial layer overlapping the outer region 200B without performing patterning during patterning of the epitaxial layer into a plurality of layers. Therefore, the height of the dam DM may be substantially equal to the height of the plurality of light emitting diodes LED.

[0087] Meanwhile, the minimum width of the dam DM may be designed in consideration of the maximum offset distance between the wafer 200 and the donor substrate 300 and the width of the region where the plurality of dam protrusions 335 of the donor substrate 300 are provided. In the selective transfer method of transferring only some of the plurality of light emitting diodes LED on the wafer 200 to the donor substrate 300, the bonding position of the donor substrate 300 and the wafer 200 may be slightly changed. For example, the bonding position of the donor substrate 300 and the wafer 200 may be changed within a third distance D3, which is a distance between the plurality of chip protrusions 331 of the donor substrate 300 to be described later. At this time, at least a portion of the dam DM may contact the plurality of dam protrusions 335 in the non-transfer region 330B of the donor substrate 300 to be described later, so as to improve the adhesion between the donor substrate 300 and the wafer 200. In this case, in order to make at least a portion of the dam DM contact the plurality of dam protrusions 335, the minimum width of the dam DM may be configured to be equal to or greater than the distance of maximum offset between the donor substrate 300 and the wafer 200, for example, the third distance D3. If the minimum width of the dam DM is less than or equal to the third distance D3, at least a portion of the dam DM may be difficult to adhere to the non-transfer region 330B of the donor substrate 300, and the adhesion between the donor substrate 300 and the wafer 200 may be reduced. Therefore, by configuring the minimum width of the dam DM to be equal to or greater than the distance of maximum offset between the wafer 200 and the donor substrate 300, a certain degree or more of adhesion between the wafer 200 and the donor substrate 300 during the transfer process may be ensured.

[0088] The distance between the dam DM in the outer region 200B and the light emitting diode LED disposed at the outermost portion in the active region 200A may be equal to or greater than the distance from the outside of one light emitting diode LED to the outside of another light emitting diode LED adjacent to the one light emitting diode LED. In this case, the distance from the outside of one light emitting diode LED to the outside of another light emitting diode LED adjacent thereto may be less than the second distance D2. The distance between the dam DM in the outer region 200B and the light emitting diode LED disposed at the outermost portion in the active region 200A is formed to be equal to or greater than the distance from the outside of one light emitting diode LED to the outside of another light emitting diode LED adjacent thereto, so that interference between the light emitting diode LEDs during the transfer process may be minimized, which will be referred to later. Figure 4E describe.

[0089] At the same time, despite Figure 4A It is shown that the dam DM is disposed adjacent to the respective four sides of the active region 200A, but the dam DM may be formed to extend to the edge of the wafer 200, or the dam DM may be formed in the entire outer region 200B except for a portion where a structure such as a plurality of alignment keys AK is formed and may be integrally formed. However, the present disclosure is not limited thereto.

[0090] At the same time, the dam DM may be disposed between the active region 200A and the second alignment key AK2. The second alignment key AK2 may be disposed outside the dam DM in the outer region 200B. When the second alignment key AK2 is formed by the same process as that of the plurality of light emitting diodes LED, the second alignment key AK2 may also be patterned together with the epitaxial layer when the epitaxial layer is patterned for forming the plurality of light emitting diodes LED. That is, the second alignment key AK2 may be formed by patterning the epitaxial layer formed in the outer region 200B. In this case, after the region for forming the dam DM is sufficiently ensured, the second alignment key AK2 may be formed outside the dam DM. Therefore, the second alignment key AK2 may be disposed to be spaced from the active region 200A by a distance equal to or greater than the minimum width of the dam DM, for example, a third distance D3.

[0091] Reference Figure 4B , the donor substrate 300 includes a base layer 310 , an adhesive layer 320 , a resin layer 330 , a plurality of chip protrusions 331 , a plurality of alignment protrusions 332 , and a plurality of dam protrusions 335 .

[0092] The base layer 310 is a component that supports various components included in the donor substrate 300, and may be formed of a material that is at least more rigid than the resin layer 330 so as to minimize bending of the resin layer 330. The base layer 310 may be disposed under the resin layer 330 and support the resin layer 330, the plurality of chip protrusions 331, and the plurality of alignment protrusions 332. For example, the base layer 310 may include a polymer or plastic, and may be formed of polycarbonate (PC) or polyethylene terephthalate (PET), but the present disclosure is not limited thereto.

[0093] A resin layer 330 is disposed on the base layer 310. The resin layer 330 may support a plurality of chip protrusions 331 to which a plurality of light emitting diodes LED are attached during the transfer process. The resin layer 330 may be formed of a polymer resin having viscoelasticity. For example, the resin layer 330 may be composed of polydimethylsiloxane (PDMS), polyurethane acrylate (PUA), polyethylene glycol (PEG), polymethyl methacrylate (PMMA), polystyrene (PS), epoxy resin, polyurethane resin, acrylic resin, etc., but is not limited thereto.

[0094] The resin layer 330 includes a transfer region 330A and a non-transfer region 330B. The transfer region 330A is a region where a plurality of chip protrusions 331 are provided. The transfer region 330A is a region where a plurality of chip protrusions 331 to which a plurality of light emitting diodes LED are attached are provided, and may be provided to overlap at least a portion of the wafer 200 or the display panel PN during the transfer process.

[0095] The non-transfer region 330B is a region where a plurality of alignment protrusions 332 and a plurality of dam protrusions 335 are provided. The second alignment key AK2 of the wafer 200 may be transferred to the non-transfer region 330B.

[0096] The plurality of chip protrusions 331 are protrusions where the plurality of light emitting diodes LED are disposed, and may be formed to extend from one surface of the resin layer 330. The plurality of chip protrusions 331 may be formed integrally with the resin layer 330, and may be formed of a polymer material having viscoelasticity in the same manner as the resin layer 330. For example, the plurality of chip protrusions 331 may be formed of polydimethylsiloxane (PDMS), polyurethane acrylate (PUA), polyethylene glycol (PEG), polymethyl methacrylate (PMMA), polystyrene (PS), epoxy resin, polyurethane resin, acrylic resin, etc., but are not limited thereto.

[0097] A plurality of light emitting diodes LED may be temporarily attached to the upper surface of the plurality of chip protrusions 331. A plurality of light emitting diodes LED formed on the wafer 200 may be transferred to the upper surface of the plurality of chip protrusions 331, and the state in which the plurality of light emitting diodes LED are attached to the upper surface of the plurality of chip protrusions 331 may be temporarily maintained until the plurality of light emitting diodes LED are transferred to the display panel PN. The donor substrate 300 including the resin layer 330 formed of a flexible material and the plurality of chip protrusions 331 integrally formed with the resin layer 330 and to which the plurality of light emitting diodes LED are temporarily attached may be defined as a flexible substrate.

[0098] In this case, the plurality of chip protrusions 331 may be arranged at a third distance D3. The third distance D3 may be greater than the second distance D2, which is the distance between the plurality of light emitting diodes LED of the wafer 200. The third distance D3 of the plurality of chip protrusions 331 may be N times the second distance D2 of the plurality of light emitting diodes LED of the wafer 200. In this case, only some of the plurality of light emitting diodes LED arranged at the second distance D2 on the wafer 200 may be transferred to the plurality of chip protrusions 331 of the donor substrate 300. For example, when the third distance D3 is twice the second distance D2, odd-numbered light emitting diodes LED or even-numbered light emitting diodes LED in a row may be selectively transferred to the plurality of chip protrusions 331.

[0099] In addition, the third distance D3 may be a distance of N times or 1 / N times the first distance D1, which is the distance between the plurality of pixels PX of the display panel PN, i.e., the pixel pitch. Specifically, the third distance D3 from the center of one chip protrusion 331 to the center of another chip protrusion 331 adjacent thereto may be N times or 1 / N times the pixel pitch. The distance between the plurality of chip protrusions 331 is formed to be N times or 1 / N times the pixel pitch, and the pixel pitch of the display panel PN changes, so that the plurality of light emitting diodes LED can be transferred to one donor substrate 300. Considering the third distance D3 as the distance between the plurality of chip protrusions 331 and the first distance D1 as the pixel pitch, the plurality of light emitting diodes LED disposed on the plurality of chip protrusions 331 are selectively transferred, so that the pixel pitch can be changed. For example, when the pixel pitch is formed to be the same as the third distance D3 as the distance between the plurality of chip protrusions 331, the plurality of light emitting diodes LED on the plurality of chip protrusions 331 can be transferred to the display panel PN at one time. For example, when the pixel pitch is formed to be twice the third distance D3 of the plurality of chip protrusions 331, the plurality of light emitting diodes LED on only the odd-numbered chip protrusions 331 or the even-numbered chip protrusions 331 among the plurality of chip protrusions 331 arranged in the same row are shifted, thereby adjusting the pixel pitch. However, the arrangement of the plurality of chip protrusions 331 and the distances therebetween may be variously changed according to the design, but are not limited thereto.

[0100] The size of the plurality of chip protrusions 331 may be larger than the size of the plurality of light emitting diodes LED. Since the size of the upper surface of the plurality of chip protrusions 331 is formed larger than the size of the plurality of light emitting diodes LED, even if an alignment error between the donor substrate 300 and the wafer 200 occurs, the plurality of light emitting diodes LED may be placed on the plurality of chip protrusions 331. Therefore, in consideration of the alignment error between the wafer 200 and the donor substrate 300, the size of the upper surface of the plurality of chip protrusions 331 may be formed larger than the size of the plurality of light emitting diodes LED.

[0101] A plurality of alignment protrusions 332 and a plurality of dam protrusions 335 are provided in the non-transfer region 330B.

[0102] The plurality of alignment protrusions 332 include a plurality of first alignment protrusions 333 and a plurality of second alignment protrusions 334 .

[0103] The plurality of first alignment protrusions 333 are components for aligning the wafer 200 and the donor substrate 300. The plurality of first alignment protrusions 333 may be provided to correspond to the first alignment key AK1 of the wafer 200. For example, the alignment and parallelism of the wafer 200 and the donor substrate 300 may be matched by aligning the first alignment key AK1 of the wafer 200 and the first alignment protrusions 333 of the donor substrate 300. In this case, the first alignment protrusions 333 and the first alignment key AK1 may have different shapes or sizes for easy identification thereof. For example, any one of the first alignment protrusions 333 and the first alignment key AK1 may have a ring shape with a hole in the middle, and the other of the first alignment protrusions 333 and the first alignment key AK1 may have a circular shape overlapping the hole. Figure 4A and Figure 4B It is shown that the first alignment key AK1 of the wafer 200 and the first alignment protrusion 333 of the donor substrate 300 have a circular shape, but the shapes of the first alignment key AK1 and the first alignment protrusion 333 are not limited thereto.

[0104] The second alignment protrusion 334 may be provided to correspond to the second alignment key AK2 of the wafer 200. For example, two second alignment protrusions 334 may be provided in each of the non-transfer region 330B provided above the transfer region 330A and the non-transfer region 330B provided below the transfer region 330A. After aligning the wafer 200 and the donor substrate 300 by aligning the first alignment key AK1 of the wafer 200 and the first alignment protrusion 333 of the donor substrate 300, the plurality of light emitting diodes LED of the wafer 200 may be transferred to the plurality of chip protrusions 331 of the donor substrate 300, and the second alignment key AK2 of the wafer 200 may be transferred to the second alignment protrusion 334. In this case, the display panel PN and the donor substrate 300 may be aligned using the second alignment key AK2 transferred to the donor substrate 300.

[0105] The plurality of dam protrusions 335 include a plurality of first dam protrusions 335a and a plurality of second dam protrusions 335b. The plurality of dam protrusions 335 are in contact with the dam DM of the wafer 200 during the transfer process, and can improve the adhesion between the wafer 200 and the donor substrate 300, and at the same time minimize the deformation of the plurality of chip protrusions 331 due to the impact applied to the donor substrate 300. For example, after bonding the wafer 200 and the donor substrate 300, when the plurality of light emitting diodes LED are transferred onto the donor substrate 300, an impact may be applied to the donor substrate 300 while the plurality of light emitting diodes LED are moved onto the donor substrate 300. When the impact is applied to the donor substrate 300, the position or shape of the plurality of chip protrusions 331 of the transfer region 330A and the resin layer 330 may be deformed. At this time, the plurality of dam protrusions 335 disposed in the non-transfer region 330B surrounding the transfer region 330A can maintain a bonding state with the wafer 200 and minimize deformation of the plurality of chip protrusions 331 of the transfer region 330A and the resin layer 330. In addition, the plurality of dam protrusions 335 can contact one or more dams DM of the wafer 200 to maintain a bonding state between the wafer 200 and the donor substrate 300.

[0106] In addition, one or more dam protrusions 335 may be disposed adjacent to the plurality of alignment protrusions 332. One or more dam protrusions 335 may be disposed between the plurality of alignment protrusions 332 and the transfer region 330A or between the plurality of alignment protrusions 332 and the edge of the resin layer 330. One or more dam protrusions 335 may be disposed adjacent to the plurality of alignment protrusions 332 to minimize separation of the donor substrate 300 and the wafer 200 due to deterioration of adhesion between the donor substrate 300 and the wafer 200 in the region where the plurality of alignment protrusions 332 are disposed during the transfer process.

[0107] The size of the plurality of dam protrusions 335 may be equal to or greater than the size of the plurality of chip protrusions 331, and may have the same height as the plurality of chip protrusions 331. In addition, when the size of the plurality of dam protrusions 335 is greater than the size of the plurality of chip protrusions 331, the plurality of dam protrusions 335 may be formed in various shapes. For example, a plurality of first dam protrusions 335a disposed in the non-transfer region 330B above the transfer region 330A and in the non-transfer region 330B below the transfer region 330A among the plurality of dam protrusions 335 may have a square shape and be spaced apart from each other. For example, a plurality of second dam protrusions 335b disposed in the non-transfer region 330B on the left side of the transfer region 330A and in the non-transfer region 330B on the right side of the transfer region 330A among the plurality of dam protrusions 335 may have a rectangular shape. However, the shape of the plurality of dam protrusions 335 may be configured in various ways, but is not limited thereto.

[0108] In addition, the minimum width of the area where the plurality of dam protrusions 335 are provided may be the same as the minimum width of the dam DM. For example, the minimum width of the area where the plurality of dam protrusions 335 are provided may be configured to be equal to or greater than the third distance D3, which is the distance of the maximum offset between the wafer 200 and the donor substrate 300. At this time, in the accompanying drawings, it is shown that the plurality of dam protrusions 335 are provided in the entire non-transfer area 330B, so that the width of the non-transfer area 330B where the plurality of dam protrusions 335 are provided corresponds to the minimum width of the dam DM of the wafer 200. However, the plurality of dam protrusions 335 are provided only in a portion of the non-transfer area 330B, so that the width of the non-transfer area 330B and the size of the area where the plurality of dam protrusions 335 are provided may be different from each other, but the present disclosure is not limited thereto.

[0109] Furthermore, by providing a plurality of dam protrusions 335 spaced apart from each other in the non-transfer region 330B of the donor substrate 300, air entrapment between the dam DM and the dam protrusions 335 can be reduced when the wafer 200 and the donor substrate 300 are bonded to each other. This will be described later with reference to Figure 4C Detailed description.

[0110] Meanwhile, in the donor substrate 300, a plurality of chip protrusions 331 may not be provided, and a plurality of light emitting diodes LED may be directly transferred onto the resin layer 330. That is, the donor substrate 300 may not include a separate chip protrusion 331. The structure of the donor substrate 300 may vary according to the shape, arrangement, and transfer method of the plurality of light emitting diodes LED, but is not limited thereto. Hereinafter, for ease of description, it is described under the assumption that the donor substrate 300 includes a plurality of chip protrusions 331 and a plurality of light emitting diodes LED are transferred to the plurality of chip protrusions 331, respectively.

[0111] The adhesive layer 320 is disposed between the resin layer 330 and the base layer 310. The adhesive layer 320 bonds the resin layer 330 and the base layer 310. The adhesive layer 320 may be formed of a material having adhesiveness, and may be formed of, for example, an optically clear adhesive (OCA), a pressure sensitive adhesive (PSA), etc., but the present disclosure is not limited thereto.

[0112] However, the adhesive layer 320 may be omitted according to the design. For example, the resin layer 330 may be formed by directly coating a material constituting the resin layer 330 on the base layer 310 and then curing it. In this case, since the resin layer 330 may be attached to the base layer 310 even if the adhesive layer 320 is not provided, the adhesive layer 320 may be omitted according to the design, but is not limited thereto.

[0113] Next, let’s refer to Figure 4C, a wafer 200 formed with a plurality of light emitting diodes LED and a donor substrate 300 are placed in a process device. Then, the wafer 200 and the donor substrate 300 placed in the process device are aligned. In a state where the wafer 200 and the donor substrate 300 are arranged so that the plurality of light emitting diodes LED on the wafer 200 and the plurality of chip protrusions 331 of the donor substrate 300 face each other, the wafer 200 and the donor substrate 300 can be aligned. For example, the wafer 200 and the donor substrate 300 can be aligned by aligning the center of the first alignment protrusion 333 of the donor substrate 300 and the center of the first alignment key AK1 of the wafer 200.

[0114] After the alignment of the wafer 200 and the donor substrate 300 is completed, the wafer 200 and the donor substrate 300 are bonded together in step S110. The wafer 200 and the donor substrate 300 may be bonded to each other so that the plurality of light emitting diodes LED in the active region 200A of the wafer 200 corresponds to the plurality of chip protrusions 331 in the transfer region 330A of the donor substrate 300. The wafer 200 and the donor substrate 300 may be bonded to each other so that the dam DM in the outer region 200B of the wafer 200 corresponds to the plurality of dam protrusions 335 in the non-transfer region 330B of the donor substrate 300.

[0115] In this case, the dam DM of the wafer 200 and the plurality of dam protrusions 335 of the donor substrate 300 are bonded to each other, so that the contact area between the wafer 200 and the donor substrate 300 can be increased, and the wafer 200 and the donor substrate 300 can be uniformly bonded together. For example, the dam DM disposed to surround the active region 200A of the wafer 200 is bonded to the plurality of dam protrusions 335 of the donor substrate 300, so that the entire wafer 200 and the entire donor substrate 300 can be uniformly bonded to each other. If the dam DM is formed in only some of the four sides of the active region 200A in the wafer 200, a difference in adhesiveness occurs between the region where the dam DM is formed and the region where the dam DM is not formed, and thus it may be difficult to uniformly bond the entire surface of the wafer 200 and the donor substrate 300. In this case, bonding defects between the plurality of light emitting diodes LED of the wafer 200 and the plurality of chip protrusions 331 of the donor substrate 300 may occur. Therefore, by forming the plurality of dams DM in the entire outer region 200B of the wafer 200 , adhesion between the wafer 200 and the donor substrate 300 may be uniformly improved, and bonding defects between the plurality of light emitting diodes LED and the plurality of chip bumps 331 may be reduced.

[0116] In addition, a plurality of dam protrusions 335 spaced apart from each other are provided in the non-transfer region 330B of the donor substrate 300 corresponding to the outer region 200B of the wafer 200, so that air entrapment can be minimized. Specifically, a dam DM having a size relatively larger than that of the plurality of dam protrusions 335 may be provided in the outer region 200B of the wafer 200. When the dam protrusion 335 is formed to have a size corresponding to the size of the dam DM, even if the adhesion between the wafer 200 and the donor substrate 300 is increased due to an increase in the contact area between the dam DM and the dam protrusion 335, a non-bonding region caused by air entrapment of the dam DM and the dam protrusion 335 may be generated. Therefore, a plurality of dam protrusions 335 corresponding to the dam DM are formed to be spaced apart from each other so that air can move to the outside of the wafer 200 and the donor substrate 300 through the empty space between the plurality of dam protrusions 335. At this time, the dam protrusion 335 disposed above or below the transfer region 330A can form an air channel extending in the column direction, and the dam protrusion 335 disposed on the left or right side of the transfer region 330A can form an air channel extending in the row direction. Therefore, by disposing a plurality of dam protrusions 335 spaced apart from each other in the non-transfer region 330B of the donor substrate 300, a path through which air moves when the wafer 200 and the donor substrate 300 are bonded can be formed, and an area where the wafer 200 and the donor substrate 300 are not bonded due to air stagnation can be reduced.

[0117] Next, in step S120, the plurality of light emitting diodes LED of the wafer 200 are transferred to the donor substrate 300. In a state where the wafer 200 and the donor substrate 300 are disposed to face each other, laser light may be selectively irradiated only to the light emitting diodes LED to be transferred to the donor substrate 300 among the plurality of light emitting diodes LED. The light emitting diodes LED irradiated with laser light may be separated from the wafer 200 and bonded to the plurality of chip bumps 331 of the donor substrate 300.

[0118] According to the design, the plurality of light emitting diodes LED may be transferred to only some chip bumps 331 among the plurality of chip bumps 331 of the donor substrate 300, and the plurality of light emitting diodes LED may be transferred to all of the plurality of chip bumps 331. For example, when the red light emitting diode LED, the green light emitting diode LED, and the blue light emitting diode LED from different wafers 200 are transferred to one donor substrate 300, the light emitting diode LED from one wafer 200 may be transferred to only some chip bumps 331 among the plurality of chip bumps 331. For example, when only one kind of light emitting diode LED is transferred to one donor substrate 300, and thus only one kind of light emitting diode LED is transferred to the display panel PN, the light emitting diode LED from one wafer 200 may be transferred to all of the plurality of chip bumps 331. However, considering the third distance D3 which is the distance between the plurality of chip protrusions 331 and the first distance D1 which is the distance between the plurality of pixels PX of the display panel PN, the type of light-emitting diodes LED transferred during the transfer process and the number and positions of the chip protrusions 331 to which the light-emitting diodes LED are transferred may be designed differently, but are not limited thereto.

[0119] At the same time, at least some of the second alignment keys AK2 among the plurality of second alignment keys AK2 of the wafer 200 may also be transferred to the donor substrate 300. In a state where the wafer 200 and the donor substrate 300 are disposed to face each other, laser may be selectively irradiated onto only some of the second alignment keys AK2 among the plurality of second alignment keys AK2 to be transferred to the donor substrate 300. In addition, the second alignment keys AK2 irradiated with laser may be separated from the wafer 200 and bonded to the second alignment protrusions 334 of the donor substrate 300.

[0120] In this case, if the plurality of second alignment keys AK2 are disposed to deviate from their original positions on the plurality of second alignment protrusions 334, the plurality of light emitting diodes LED that maintain a constant distance from the plurality of second alignment keys AK2 may also be disposed to deviate from their original positions on the plurality of chip protrusions 331. Therefore, the positions of the plurality of light emitting diodes LED can be easily identified by the second alignment keys AK2. However, the second alignment keys AK2 may not be transferred together with the plurality of light emitting diodes LED, but the present disclosure is not limited thereto.

[0121] Next, refer to Figure 4D and Figure 4E After the plurality of light emitting diodes LED of the wafer 200 are transferred to the donor substrate 300 , the wafer 200 and the donor substrate 300 are separated from each other in step S130 .

[0122] Reference Figure 4D, the wafer 200 and the donor substrate 300 in a bonded state may be carried on the stage ST. The wafer 200 and the donor substrate 300 in a bonded state may be located between the stage ST and the head HD. The wafer 200 may be disposed to correspond to the head HD, and the donor substrate 300 may be disposed to correspond to the stage ST.

[0123] However, in the present disclosure, it has been described that the chip 200 and the donor substrate 300 are moved to the platform ST for the separation process of the chip 200 and the donor substrate 300, but the bonding process and the separation process of the chip 200 and the donor substrate 300 can be performed on the same platform, but is not limited to this.

[0124] Then, in step S131, a portion of the outermost portion of the donor substrate 300 is physically fixed to the platform ST. One edge among the multiple edges of the donor substrate 300 or at least one corner among the four corners of the donor substrate 300 may be fixed to the platform ST using a fixing member GR. In addition, the remaining portion of the donor substrate 300 that is not fixed to the platform ST by the fixing member GR may be moved on the platform ST. For example, one edge among the outermost portion of the donor substrate 300 may be fixed to the platform ST by a clamper. For example, two adjacent corner portions among the outermost portion of the donor substrate 300 may be fixed to the platform ST by a clamper. The platform ST may not vacuum adsorb the donor substrate 300, and the platform ST and the donor substrate 300 may be physically fixed by the fixing member GR.

[0125] Then, in step S132, the wafer 200 is fixed to the head HD. One surface of the wafer 200 may be fixed to the head HD. For example, the entire one surface of the wafer 200 may be fixed to the head HD by a vacuum adsorption method, or may be fixed to the head HD by a fixing member. In this case, the head HD and the wafer 200 may be vacuum adsorbed by moving the stage ST toward the head HD, or the head HD and the wafer 200 may be vacuum adsorbed by moving the head HD toward the wafer 200.

[0126] Next, refer to Figure 4E, in step S133, the head HD and / or the stage ST are moved. The head HD and the stage ST are spaced apart from each other to separate the wafer 200 and the donor substrate 300. Specifically, by moving the head HD, the stage ST, or the head HD and the stage ST away from each other, the wafer 200 fixed to the head HD and the donor substrate 300 of which a portion is fixed to the stage ST can be separated. In this case, the wafer 200 and the donor substrate 300 can be separated by moving at least one of the head HD and the stage ST in a direction perpendicular to one surface of the stage ST, that is, in the Z-axis direction. For example, the head HD or the stage ST may be moved in the Z-axis direction, or both the head HD and the stage ST may be moved in the Z-axis direction.

[0127] In this case, the entire one surface of the wafer 200 fixed to the head HD by the vacuum adsorption method can be maintained in a state of being attached to the head HD. On the other hand, in the donor substrate 300 in which only the edge or corner thereof is fixed to the stage ST, the remaining portion thereof which is not fixed to the stage ST and is thus configured to be movable can be moved together with the wafer 200 and the head HD. When the wafer 200 and the donor substrate 300 are moved in a direction away from each other in a state in which the entire one surface of the wafer 200 is fixed to the head HD and only a portion of the outermost portion of the donor substrate 300 is fixed to the stage ST, the wafer 200 and the donor substrate 300 can be separated in a form in which they are separated row by row (hereinafter, referred to as "row by row separation").

[0128] For example, when the wafer 200 and the head HD move in the Z-axis direction in a state where the right edge of the donor substrate 300 is fixed to the stage ST, the remaining portion of the donor substrate 300 bonded to the wafer 200 may move in the Z-axis direction together with the wafer 200 and the head HD. First, when the wafer 200 and the head HD begin to move in the Z-axis direction, the right edge of the donor substrate 300 that cannot move together with the wafer 200 may be separated first. And, as the head HD and the wafer 200 gradually move away from the donor substrate 300, starting from a portion thereof adjacent to the right edge of the donor substrate 300, the donor substrate 300 may be separated from the wafer 200 in sequence. Finally, the left edge of the donor substrate 300 is separated from the wafer 200, and the separation of the wafer 200 and the donor substrate 300 may be completed. Therefore, a plurality of light emitting diodes LED of a plurality of chip protrusions 331 bonded to the donor substrate 300 may be separated from the wafer 200 row by row.

[0129] Meanwhile, the remaining portion of the donor substrate 300 that is not physically fixed to the stage ST moves with the wafer 200 during the separation process and is lifted from the stage ST, and when the separation is completed, it may be placed on the stage ST. In this case, a vertical impact may be applied to the donor substrate 300 and the plurality of light emitting diodes LED. However, since the plurality of light emitting diodes LED bonded to the plurality of chip protrusions 331 of the donor substrate 300 are very resistant to vertical impact, even if the donor substrate 300 is lifted from the stage ST during the process, the possibility of transfer defects of the plurality of light emitting diodes LED is low.

[0130] Furthermore, in order to reduce interference between the dam DM of the wafer 200 and the light emitting diode LED disposed at the outermost portion of the active region 200A during the row-by-row separation process, the distance between the dam DM and the light emitting diode LED may be formed to be equal to or greater than the distance from the outside of one light emitting diode LED to the outside of another light emitting diode LED adjacent thereto. As described above, when the wafer 200 and the donor substrate 300 are separated, the plurality of light emitting diode LEDs may be separated from the wafer 200 row by row. At this time, if a sufficient distance is not ensured between the dam DM and the active region 200A, the light emitting diode LED at the outermost portion and the dam DM of the wafer 200 may be interfered in the process in which the dam DM and the light emitting diode LED at the outermost portion of the active region 200A transferred to the donor substrate 300 are sequentially separated. In the case of a surface separation method (hereinafter, referred to as "surface separation") in which the entire surface of the donor substrate 300 and the entire surface of the wafer 200 are separated at once, the light emitting diode LED at the outermost portion and the dam DM may not be interfered. However, in the LED transfer method according to the exemplary embodiment of the present disclosure and the method for manufacturing the display device 100 using the same, since the wafer 200 and the donor substrate 300 are separated in a row-by-row separation method, interference may occur between the dam DM and the light emitting diode LED at the outermost portion where the row-by-row separation is finally performed, which may cause transfer defects of the plurality of light emitting diodes LED. Therefore, a sufficient distance is ensured between the dam DM of the outer region 200B of the wafer 200 and the plurality of light emitting diodes LED of the active region 200A, so that the interference between the dam DM and the plurality of light emitting diodes LED can be reduced when the wafer 200 and the donor substrate 300 are separated.

[0131] Meanwhile, when a portion of the outermost portion of the donor substrate 300 is fixed to the platform ST by a vacuum adsorption method instead of being physically fixed, it may be disadvantageous in terms of process time and yield. In the case of partially vacuum adsorbing the edge of the donor substrate 300, it may be feasible to separate row by row. However, when the separation speed of the wafer 200 and the donor substrate 300 increases, since the speed and the adhesiveness are proportional to each other, the adhesiveness between the wafer 200 and the donor substrate 300 may increase, and it may be difficult to maintain a sufficiently strong vacuum pressure to fix the donor substrate 300. On the contrary, when the separation speed of the wafer 200 and the donor substrate 300 decreases, the adhesiveness is relatively low, so that the non-transfer defects of multiple light emitting diodes LED may increase, and the process time may also increase. Therefore, when the donor substrate 300 is fixed by a vacuum adsorption method, it is disadvantageous in terms of process time and transfer yield, so a portion of the outermost portion of the donor substrate 300 may be physically fixed to the platform ST.

[0132] Reference Figure 4F By completing one transfer process, a plurality of light emitting diodes LED may be disposed on the donor substrate 300. In this case, the plurality of light emitting diodes LED disposed on the donor substrate 300 may be radially disposed around one light emitting diode LED' among the plurality of light emitting diodes LED.

[0133] Specifically, one LED LED' among the plurality of LEDs may be disposed at the center of the chip protrusion 331 of the donor substrate 300. In addition, as the LEDs are moved away from one LED LED' with one LED LED' as the center, they may be disposed to be spaced apart from the center of the chip protrusion 331. For example, an LED LED adjacent to one LED LED' may be disposed to be adjacent to the center of the chip protrusion 331, and an LED LED disposed away from one LED LED' may be disposed to be spaced apart from the center of the chip protrusion 331. For example, some LEDs LED disposed rightward from one LED LED' may be disposed to deviate rightward from the center of the chip protrusion 331, and some LEDs LED disposed upward from one LED LED' may be disposed to deviate upward from the center of the chip protrusion 331.

[0134] In this case, one light emitting diode LED' may vary according to the portion of the donor substrate 300 fixed to the platform ST. For example, when the right edge of the donor substrate 300 is fixed to the platform ST, one light emitting diode LED' may be one of the light emitting diodes LED set in the left region relative to the center of the donor substrate 300. Specifically, when the donor substrate 300 and the wafer 200 are separated from each other, the maximum tension may act on the right edge of the donor substrate 300 physically fixed to the platform ST and the region adjacent to the right edge. That is, when the donor substrate 300 and the wafer 200 are separated, the tension acting on the donor substrate 300 may vary according to the fixed portion, and due to the change in tension, the plurality of light emitting diodes LED may be radially transferred on the plurality of chip protrusions 331. Therefore, when the donor substrate 300 and the wafer 200 are separated in a row-by-row separation form after physically fixing only one end of the donor substrate 300, the plurality of light emitting diodes LED set on the donor substrate 300 may be radially distributed.

[0135] Finally, refer to Figure 4G By performing the secondary transfer process, the plurality of light emitting diodes LED on the donor substrate 300 can be transferred to the display panel PN, thereby completing the manufacturing process of the display device 100. In this case, the display panel PN is a circuit for driving the plurality of light emitting diodes LED, for example, the display panel PN in which the formation of the driving transistor 120 and the plurality of lines is completed.

[0136] First, the donor substrate 300 provided with a plurality of light emitting diodes LED and the display panel PN are placed in a process device. Next, the donor substrate 300 and the display panel PN are aligned.

[0137] In this case, the donor substrate 300 and the display panel PN may be aligned based on the second alignment key AK2 transferred from the wafer 200 to the donor substrate 300 and the alignment key of the display panel PN.

[0138] The plurality of light emitting diodes LED and the second alignment key AK2 disposed on the donor substrate 300 are transferred in the same process. Therefore, the relative positions of the plurality of light emitting diodes LED and the second alignment key AK2 may be constant. Therefore, when the donor substrate 300 and the display panel PN are aligned based on the second alignment key AK2 whose relative positions relative to the plurality of light emitting diodes LED are constant, the alignment accuracy capable of transferring the plurality of light emitting diodes LED to appropriate positions may be improved. Therefore, when the plurality of light emitting diodes LED of the donor substrate 300 are transferred to the display panel PN, the donor substrate 300 and the display panel PN may be aligned based on the second alignment key AK2. However, in the present disclosure, it has been described that the donor substrate 300 and the display panel PN are aligned based on the second alignment key AK2, but the donor substrate 300 and the display panel PN may be aligned based on other components, and the present disclosure is not limited thereto.

[0139] The alignment key of the display panel PN aligned with the second alignment key AK2 on the donor substrate 300 may be any one of the components formed on the display panel PN, or may be formed and arranged separately. For example, when the alignment key is any one of the components formed on the display panel PN, a reflective layer overlapping with a plurality of light emitting diodes LED among the components formed on the display panel PN, some lines among a plurality of lines arranged to drive a plurality of light emitting diodes LED, etc. may be used as the alignment key. In addition, in the case where the alignment key is formed and arranged separately, the alignment key may be a pattern or structure formed on the display panel PN, but is not limited thereto.

[0140] Next, after the alignment of the donor substrate 300 and the display panel PN is completed, the donor substrate 300 and the display panel PN are bonded together in step S140. Next, in step S150, the plurality of light emitting diodes LED are transferred to the display panel PN. Then, after the plurality of light emitting diodes LED of the donor substrate 300 are transferred to the display panel PN, the donor substrate 300 and the display panel PN are separated in step S160. In this case, the plurality of light emitting diodes LED radially distributed on the donor substrate 300 may be radially distributed even after being transferred to the display panel PN.

[0141] In this case, the donor substrate 300 and the display panel PN may be formed as follows. Figure 4E For example, the donor substrate 300 and the display panel PN may be separated by a surface separation method in which the entire surface thereof is separated at once, and the donor substrate 300 and the display panel PN may be separated in various ways.

[0142] Therefore, the manufacturing process of the display device 100 can be completed by the process of primarily transferring the plurality of light emitting diodes LED from the wafer 200 to the donor substrate 300 and secondarily transferring the transferred plurality of light emitting diodes LED from the donor substrate 300 to the display panel PN.

[0143] Meanwhile, in some cases, as a donor substrate, a rigid substrate other than a flexible substrate may be used. For example, the donor substrate may be formed of a hard material instead of a material such as PDMS. However, when the donor substrate is a rigid substrate, it is difficult to configure the donor substrate in a large area due to thickness variation, and there is a problem in that the number of transfers increases. On the other hand, when the donor substrate 300 is formed of a flexible substrate, the area of ​​the donor substrate 300 may be increased and damage to the light emitting diode LED may be minimized. Therefore, in the LED transfer method according to an exemplary embodiment of the present disclosure and the method for manufacturing the display device 100 using the same, a flexible substrate may be used as the donor substrate 300.

[0144] Meanwhile, when the wafer 200 is separated from the donor substrate 300 as a flexible substrate by the surface separation method, a transfer defect of a plurality of light emitting diodes LED may occur. For example, in order to separate the donor substrate 300 and the wafer 200 by the surface separation method, the separation process may be performed in a state where the entire one surface of the donor substrate 300 is fixed to the stage ST and the entire one surface of the wafer 200 is fixed to the head HD. At this time, when the donor substrate 300 as a flexible substrate is fixed to the stage ST by the vacuum adsorption method, a wrinkle phenomenon may occur in the donor substrate 300, which may cause a transfer defect of a plurality of LEDs. The wrinkle phenomenon is a phenomenon in which the surface of the donor substrate 300 formed of a flexible material becomes uneven due to an external force such as a vacuum adsorption force. In addition, the surface tension generated during the surface separation or the external force caused by the vacuum adsorption affects the light emitting diode LED of a micro size, so that the light emitting diode LED may be transferred in a state in which it is flipped or tilted, or may be transferred in a rotated state. Such a transfer defect may occur randomly in the surface separation area SA, which may result in a reduction in yield and an increase in process cost.

[0145] On the other hand, in the LED transfer method according to the exemplary embodiment of the present disclosure, since only one end of the donor substrate 300 as a flexible substrate is physically fixed, the external force due to vacuum adsorption can be minimized, and since the donor substrate 300 is naturally separated from the wafer 200 row by row even during the separation process, the surface tension can be minimized. Specifically, one end of the donor substrate 300 as a flexible substrate can be physically fixed to the platform ST, and the wafer 200 as a rigid substrate can be fixed to the head HD by vacuum adsorption. And, the donor substrate 300 and the wafer 200 can be separated by moving the donor substrate 300, the wafer 200, or the donor substrate 300 and the wafer 200 in the vertical direction. In this case, since one end of the donor substrate 300 is physically fixed and the remaining part thereof is not fixed, the remaining part of the donor substrate 300 can move together with the wafer 200. However, as the distance between the wafer 200 and the donor substrate 300 increases, starting from one end of the donor substrate 300 fixed to the platform ST, the donor substrate 300 can be sequentially separated from the wafer 200. Therefore, in the process of separating the donor substrate 300 and the wafer 200, the external force affecting the plurality of light emitting diodes LED is reduced, and thus the transfer defects of the plurality of light emitting diodes LED can be minimized. Therefore, in the LED transfer method according to the exemplary embodiment of the present disclosure and the method for manufacturing the display device 100 using the same, the wafer 200 and the donor substrate 300 are separated in a row-by-row separation method, and thus the transfer defects of the plurality of light emitting diodes LED can be reduced.

[0146] In addition, in the LED transfer method according to the exemplary embodiment of the present disclosure and the manufacturing method of the display device 100 using the same, the non-transfer defects of multiple light-emitting diodes LEDs can be reduced by increasing the separation speed of the wafer 200 and the donor substrate 300. The material such as PDMS constituting the multiple chip protrusions 331 of the donor substrate 300 has the property of increasing adhesion according to the increase of the separation speed. Therefore, when the separation speed of the donor substrate 300 and the wafer 200 increases, the adhesion of the chip protrusions 331 can be increased to improve the adhesion of the multiple light-emitting diodes LEDs attached to the chip protrusions 331. Therefore, the non-transfer defects of multiple light-emitting diodes LEDs can be reduced by separating the wafer 200 and the donor substrate 300 in a high-speed row-by-row separation method, and at the same time, the phenomenon in which multiple light-emitting diodes LEDs are transferred in a flipped or tilted state can be minimized.

[0147] In the following, reference will be made to FIG. 5A to FIG. 6B The LED transfer method according to the exemplary embodiment of the present disclosure and the LED transfer method according to the comparative embodiment are compared.

[0148] Figure 5A and Figure 5B1 is a schematic diagram for explaining the LED transfer method according to Comparative Embodiment 1. Fig. 6A and Figure 6B Schematic diagram for explaining the LED transfer method according to Comparative Embodiment 2. Figure 5B and Figure 6B Only the base layer 310 and the resin layer 330 of the donor substrate 300 are shown.

[0149] The LED transfer method according to Comparative Embodiment 1 is a transfer method of separating the donor substrate 300 and the wafer 200 in a state where the donor substrate 300 is fixed to the stage ST using both the fixing member GR and the vacuum adsorption method. The LED transfer method according to Comparative Embodiment 2 is a transfer method of separating the donor substrate 300 and the wafer 200 in a state where both sides of the donor substrate 300 are fixed to the stage ST using only the fixing member GR.

[0150] First, refer to Figure 5A and Figure 5B In the LED transfer method according to Comparative Embodiment 1, both edges of the donor substrate 300 are fixed to the stage ST by the fixing member GR in a state where the entire one surface of the donor substrate 300 is vacuum-adsorbed to the stage ST. Then, the entire one surface of the wafer 200 is fixed to the head HD by the vacuum adsorption method.

[0151] Then, the wafer 200 and the donor substrate 300 may be moved away from each other, thereby separating the wafer 200 and the donor substrate 300. At this time, since the entire one surface of the donor substrate 300 is fixed to the stage ST and the entire one surface of the wafer 200 is also fixed to the head HD, the surface separation of the donor substrate 300 and the wafer 200 may be performed. That is, the entire surface of the resin layer 330 of the donor substrate 300 may be the surface separation area SA. Therefore, a transfer defect of a plurality of light emitting diodes LED may occur in the entire resin layer 330 where the plurality of chip protrusions 331 of the donor substrate 300 are provided.

[0152] Reference Fig. 6A and Figure 6B , in the LED transfer method according to Comparative Embodiment 2, only two edges of the donor substrate 300 are fixed to the stage ST by the fixing member GR. Then, the entire one surface of the wafer 200 is fixed to the head HD by a vacuum adsorption method.

[0153] Then, the wafer 200 and the donor substrate 300 may be moved away from each other, thereby separating the wafer 200 and the donor substrate 300. At this time, since only the two edges of the donor substrate 300 are fixed to the stage ST, and the entire one surface of the wafer 200 is fixed to the head HD, separation may be performed from the two edges of the donor substrate 300 to a partial inner region of the donor substrate 300 in a row-by-row separation method. However, the central region of the donor substrate 300 that is separated last may be separated from the wafer 200 in a surface separation method. Therefore, in the resin layer 330 provided with a plurality of chip protrusions 331, a partial region extending from the two edges may be a row-by-row separation region LA, and the remaining region in the middle may be a surface separation region SA.

[0154] Therefore, in the LED transfer method according to Comparative Embodiment 1 and Comparative Embodiment 2, at least a portion of the donor substrate 300 may be the surface separation area SA, and the probability of transfer defects of the plurality of light emitting diodes LED generated in the surface separation area SA may be increased. That is, compared with the LED transfer method according to the exemplary embodiment of the present disclosure, the LED transfer method according to Comparative Embodiment 1 and Comparative Embodiment 2 may be disadvantageous in terms of yield due to the increase in the surface separation area SA of the donor substrate 300. Therefore, in the LED transfer method according to the exemplary embodiment of the present disclosure, the stage ST and / or the head HD are moved in a state where only one end of the donor substrate 300 as a flexible substrate is physically fixed to the stage ST and one surface of the wafer 200 is vacuum-adsorbed to the head HD, so that the entire area of ​​the donor substrate 300 may be the row-by-row separation area LA, thereby reducing transfer defects of the plurality of light emitting diodes LED.

[0155] Exemplary embodiments of the present disclosure can also be described as follows:

[0156] According to one aspect of the present disclosure, a light emitting diode (LED) transfer method is provided. The light emitting diode (LED) transfer method includes: bonding a flexible substrate and a rigid substrate formed with a plurality of light emitting diodes; transferring the plurality of light emitting diodes to the flexible substrate; and separating the rigid substrate and the flexible substrate. Separating the rigid substrate and the flexible substrate includes: separating the rigid substrate and the flexible substrate in a state where one surface of the rigid substrate is fixed and a portion of the outermost portion of the flexible substrate is fixed by a fixing member.

[0157] Separating the rigid substrate and the flexible substrate may further include: carrying the rigid substrate and the flexible substrate in a bonded state on a platform.

[0158] Separating the rigid substrate and the flexible substrate may further include: fixing one edge among a plurality of edges of the flexible substrate to the platform by a fixing member. The remaining portion of the flexible substrate may be configured to be movable on the platform.

[0159] Separating the rigid substrate and the flexible substrate may further include fixing at least one corner among a plurality of corners of the flexible substrate to the platform by a fixing member. The remaining portion of the flexible substrate may be configured to be movable on the platform.

[0160] Separating the rigid substrate and the flexible substrate may further include moving the rigid substrate, the flexible substrate, or the rigid substrate and the flexible substrate in a direction perpendicular to one surface of the platform.

[0161] In separating the rigid substrate and the flexible substrate, the rigid substrate and the flexible substrate may be separated row by row.

[0162] The plurality of light emitting diodes disposed on the flexible substrate may be radially disposed around one light emitting diode among the plurality of light emitting diodes. The one light emitting diode may be spaced apart from the center of the flexible substrate.

[0163] According to another aspect of the present disclosure, a method for manufacturing a display device is provided. The method for manufacturing a display device includes: bonding a wafer and a donor substrate; transferring a plurality of light-emitting diodes of the wafer to the donor substrate; separating the wafer and the donor substrate; bonding a display panel and a donor substrate provided with a plurality of light-emitting diodes; transferring a plurality of light-emitting diodes of the donor substrate to the display panel; and separating the display panel and the donor substrate. Separating the wafer and the donor substrate includes: separating the wafer and the donor substrate while fixing one surface of the wafer to the head and fixing a portion of the outermost portion of the donor substrate to the platform.

[0164] The wafer and the display panel may be rigid substrates, and the donor substrate is a flexible substrate.

[0165] Separating the wafer and the donor substrate may further include fixing one edge among the outermost portions of the donor substrate to the stage by a clamper.

[0166] Separating the wafer and the donor substrate may further include fixing at least one corner among the outermost portions of the donor substrate to the stage by a clamper.

[0167] Separating the wafer and the donor substrate may further include fixing one surface of the wafer to the head by vacuum suction or a fixing member.

[0168] Separating the wafer and the donor substrate may further include moving the head, the platform, or the head and the platform in the Z-axis direction. When the head, the platform, or the head and the platform move in the Z-axis direction, the plurality of light emitting diodes may be separated from the wafer row by row.

[0169] When the head, the stage, or the head and the stage move in the Z-axis direction, at least a portion of the donor substrate may be spaced apart from the stage.

[0170] The wafer may include: an active region in which a plurality of light emitting diodes are formed; and an outer region in which one or more dams are formed. A distance between a light emitting diode disposed at an outermost portion of the active region among the plurality of light emitting diodes and the dam may be equal to or greater than a distance from an outer edge of one of the plurality of light emitting diodes to an outer edge of another light emitting diode adjacent to the one light emitting diode.

[0171] The donor substrate may include a chip protrusion to which each of the plurality of light-emitting diodes is bonded. One of the plurality of light-emitting diodes transferred to the donor substrate may be disposed at the center of the chip protrusion. Another light-emitting diode disposed on one side of the one of the plurality of light-emitting diodes transferred to the donor substrate may be disposed to one side relative to the center of the chip protrusion.

[0172] It is obvious to those skilled in the art that various modifications and changes can be made to the present disclosure without departing from the technical idea or scope of the present disclosure. Therefore, the present disclosure is intended to cover the modifications and changes of the present disclosure as long as they fall within the scope of the attached claims and their equivalents.

Claims

1. A light emitting diode transfer method, comprising: bonding a flexible substrate and a rigid substrate on which a plurality of light emitting diodes are formed; transferring the plurality of light emitting diodes to the flexible substrate; as well as separating the rigid substrate and the flexible substrate, Wherein, separating the rigid substrate and the flexible substrate comprises: separating the rigid substrate and the flexible substrate in a state where one surface of the rigid substrate is fixed and one edge or at least one corner of the outermost portion of the flexible substrate is fixed by a fixing member.

2. The light emitting diode transfer method according to claim 1, wherein: Separating the rigid substrate and the flexible substrate further includes: carrying the rigid substrate and the flexible substrate in a bonded state on a platform.

3. The light emitting diode transfer method according to claim 2, wherein: Separating the rigid substrate and the flexible substrate further comprises: fixing one edge of the plurality of edges of the flexible substrate to the platform by the fixing member, Wherein, the remaining portion of the flexible substrate is configured to be movable on the platform.

4. The light emitting diode transfer method according to claim 2, wherein: Separating the rigid substrate and the flexible substrate further comprises: fixing at least one corner among a plurality of corners of the flexible substrate to the platform by the fixing member, Wherein, the remaining portion of the flexible substrate is configured to be movable on the platform.

5. The light emitting diode transfer method according to claim 3 or 4, wherein: Separating the rigid substrate and the flexible substrate further includes moving the rigid substrate, the flexible substrate, or the rigid substrate and the flexible substrate in a direction perpendicular to one surface of the platform.

6. The light emitting diode transfer method according to claim 5, wherein: In separating the rigid substrate and the flexible substrate, the rigid substrate and the flexible substrate are separated row by row.

7. The light emitting diode transfer method according to claim 1, wherein: The plurality of light emitting diodes disposed on the flexible substrate are radially disposed around one light emitting diode among the plurality of light emitting diodes, The one light emitting diode is spaced apart from the center of the flexible substrate.

8. A method for manufacturing a display device, comprising: bonding the wafer and the donor substrate; transferring the plurality of light emitting diodes of the wafer to the donor substrate; separating the wafer and the donor substrate; bonding a display panel and the donor substrate provided with the plurality of light emitting diodes; transferring a plurality of light emitting diodes of the donor substrate to the display panel; as well as separating the display panel and the donor substrate, Wherein, separating the wafer and the donor substrate comprises: separating the wafer and the donor substrate while fixing one surface of the wafer to the head and fixing one edge or at least one corner of the outermost portion of the donor substrate to the platform through a fixing member.

9. The manufacturing method according to claim 8, wherein: The wafer and the display panel are rigid substrates, and the donor substrate is a flexible substrate.

10. The manufacturing method according to claim 8, wherein: Separating the wafer and the donor substrate further includes fixing one edge among the outermost portions of the donor substrate to the stage by a clamper.

11. The manufacturing method according to claim 8, wherein: Separating the wafer and the donor substrate further includes fixing at least one corner among the outermost portions of the donor substrate to the stage by a clamper.

12. The manufacturing method according to claim 8, wherein: Separating the wafer and the donor substrate further includes fixing one surface of the wafer to the head by vacuum adsorption or a fixing member.

13. The manufacturing method according to claim 8, wherein: Separating the wafer and the donor substrate further comprises: moving the head, the platform, or the head and the platform in the Z-axis direction, When the head, the platform, or the head and the platform move in the Z-axis direction, the plurality of light emitting diodes are separated from the wafer row by row.

14. The manufacturing method according to claim 13, wherein: When the head, the stage, or both the head and the stage move in the Z-axis direction, at least a portion of the donor substrate is spaced apart from the stage.

15. The manufacturing method according to claim 8, wherein: The wafer comprises: an active region in which the plurality of light emitting diodes are formed; and An outer area formed with one or more dams, Wherein, the distance between the light-emitting diode arranged at the outermost part of the active area among the multiple light-emitting diodes and the dam is equal to or greater than the distance from the outer edge of one light-emitting diode among the multiple light-emitting diodes to the outer edge of another light-emitting diode adjacent to the one light-emitting diode.

16. The manufacturing method according to claim 8, wherein: The donor substrate includes a chip bump bonded to each of the plurality of light emitting diodes, wherein one of the plurality of light emitting diodes transferred to the donor substrate is disposed at the center of the chip protrusion, Among the plurality of light emitting diodes transferred to the donor substrate, another light emitting diode disposed on one side of the one light emitting diode is disposed to be biased to one side relative to the center of the chip protrusion.

17. The manufacturing method according to claim 15, wherein: The wafer also includes a plurality of alignment keys formed in the outer region, and The plurality of alignment keys include a first alignment key for aligning the wafer and the donor substrate and a second alignment key for aligning the donor substrate and the display panel.

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