Wafer and donor substrate

Abstract

A wafer and a donor substrate are disclosed. A wafer according to an exemplary embodiment of the present disclosure includes: a substrate including an active region and an outer region; a plurality of light emitting diodes disposed at regular intervals in the active area and configured to emit light of the same color; a plurality of dams disposed in the outer region and formed at the same height as the plurality of light emitting diodes; a first alignment key disposed in the outer region and having a metal pattern; and a second alignment key disposed in the outer region, in which the substrate is formed of any one of sapphire, silicon carbide, gallium nitride, and zinc oxide, and in which the first alignment key and the second alignment key are formed of a same material as at least a portion of a material constituting the plurality of light emitting diodes.

Description

[0001] This application is a divisional application of a Chinese patent application with application number 202111363787.4, application date November 17, 2021, and invention title "Light-emitting diode transfer method and manufacturing method of a display device using the same".

[0002] Cross-reference to related applications

[0003] This application claims the benefit and priority of Korean Patent Application No. 10-2020-0166705, filed in Korea on December 2, 2020, the entire content of which is hereby incorporated by reference into this application. Technical field

[0004] The present disclosure relates to a method for transferring light-emitting diodes (LEDs) and a manufacturing method of a display device using the same, and more particularly, to an LED transfer method for increasing productivity when transferring a plurality of LEDs and a manufacturing method of a display device using the same. Background art

[0005] 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.

[0006] Such display devices are being applied to an increasing number of various fields, including not only computer monitors and TVs but also personal mobile devices, and thus, display devices with a reduced volume and weight while having a wide display area are being studied.

[0007] In recent years, display devices including light-emitting diodes (LEDs) have received attention as next-generation display devices. Since LEDs are formed of inorganic materials rather than organic materials, they have excellent reliability and a longer lifespan compared to liquid crystal displays or organic light-emitting displays. In addition, LEDs have a high emission speed, high emission efficiency, and excellent stability due to high impact resistance, and can display high-brightness images. Summary of the invention

[0008] Accordingly, embodiments of the present disclosure relate to a method for transferring light-emitting diodes (LEDs) and a manufacturing method of a display device using the same, which substantially eliminate one or more problems caused by limitations and disadvantages of the related art.

[0009] One aspect of the present disclosure is to provide a method for transferring light-emitting diodes (LEDs) and a manufacturing method of a display device using the same, which reduce defects of a plurality of light-emitting diodes during a transfer process of transferring a plurality of light-emitting diodes from a wafer to a donor substrate.

[0010] Another aspect of the present disclosure is to provide an LED transfer method with improved alignment accuracy of a plurality of light-emitting diodes 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 for reducing process time by increasing the separation speed of a wafer and a donor substrate and a method of manufacturing a display device using the same.

[0012] Still another aspect of the present disclosure is to provide an LED transfer method for minimizing deformation of a plurality of light-emitting diodes when separating a wafer and a donor substrate or a donor substrate and a display panel and a method of manufacturing a display device using the same.

[0013] Additional features and aspects will be set forth in the following description, and will be in part apparent from the description, or may be learned by practice of the inventive concept provided herein. Other features and aspects of the inventive concept may be realized and obtained by means of the structures particularly pointed out in the written description, or may be derived from the written description, its claims, and the drawings.

[0014] 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 part of the outermost portion of the flexible substrate is fixed by a fixing member. Accordingly, transfer defects of the plurality of light-emitting diodes can be reduced by separating the flexible substrate and the rigid substrate by a row-by-row separation method.

[0015] In another aspect, a method of 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 the donor substrate provided with the plurality of light-emitting diodes; transferring the 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 part of the outermost portion of the donor substrate is fixed to a platform. Accordingly, the wafer and the donor substrate can be separated by a row-by-row separation method by separating the wafer and the donor substrate in a state where only a part of the outermost portion of the donor substrate is fixed, and impact applied to the plurality of light-emitting diodes on the donor substrate can be minimized.

[0016] Other details of the exemplary embodiments are included in the detailed description and the drawings.

[0017] According to the present disclosure, when separating the donor substrate from the wafer, only one end of the donor substrate is physically fixed, thereby minimizing the deformation of the plurality of light-emitting diodes on the donor substrate.

[0018] According to the present disclosure, the reduction in the transfer yield of the plurality of light-emitting diodes can be minimized by separating the donor substrate and the wafer line by line.

[0019] According to the present disclosure, the process time and cost can be reduced and the productivity can be increased by increasing the transfer speed of the light-emitting diodes.

[0020] It should be understood that the foregoing general description and the following detailed description are both exemplary and explanatory and are intended to provide further explanation of the inventive concept claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings, which are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this application, illustrate embodiments of the present disclosure and, together with the description, serve to explain the various principles.

[0022] Figure 1 is a plan view of a display device according to an exemplary embodiment of the present disclosure.

[0023] Figure 2 is a schematic cross-sectional view of a sub-pixel constituting a plurality of pixels of a display device according to an exemplary embodiment of the present disclosure.

[0024] Figure 3 is a process flow diagram showing a manufacturing method of a display device according to an exemplary embodiment of the present disclosure.

[0025] Figures 4A to 4G is a schematic process diagram for explaining an LED transfer method according to an exemplary embodiment of the present disclosure and a manufacturing method of a display device using the same.

[0026] Figure 5A and Figure 5B is a schematic diagram for explaining an LED transfer method according to Comparative Example 1.

[0027] Figure 6A and Figure 6B is a schematic diagram for explaining an LED transfer method according to Comparative Example 2. DETAILED DESCRIPTION

[0028] Advantages and features of the present disclosure and methods for achieving the advantages and features will be described by referring to the following appended Figure 1Rather than the exemplary embodiments described in detail hereinafter. However, 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 be defined only by the scope of the appended claims.

[0029] The shapes, sizes, ratios, angles, numbers, etc. shown in the drawings for describing the exemplary embodiments of the present disclosure are only examples, and the present disclosure is not limited thereto. Throughout the specification, the same reference numerals generally denote the same elements. In addition, in the following description of the present disclosure, detailed descriptions of known related technologies may be omitted to avoid unnecessarily obscuring the subject matter of the present disclosure. Terms such as "comprising", "having", and "including" used herein generally intend to allow the addition of other components, unless these terms are used together with the term "only". Any reference to the singular form may include the plural form, unless otherwise clearly stated.

[0030] Even if not explicitly stated, components are interpreted to include a normal margin of error.

[0031] When using terms such as "on", "above", "below", and "adjacent" to describe the positional relationship between two parts, one or more parts may be located between these two components, unless these terms are used together with the terms "immediately" or "directly".

[0032] When an element or layer is provided "on another element or layer", other layers or other elements may be directly inserted on or between another element.

[0033] Although terms such as "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 may be the second component in the technical concept of the present disclosure.

[0034] Throughout the specification, the same reference numerals generally denote the same elements.

[0035] For ease of description, the dimensions and thicknesses of each component shown in the drawings are shown, and the present disclosure is not limited to the dimensions and thicknesses of the components shown.

[0036] The features of the various embodiments of the present disclosure may be partially or wholly adhered to or combined with each other, and may be interlocked and operated in technically different ways, and the embodiments may be executed independently or in association with each other.

[0037] Hereinafter, a method of transferring an LED and a method of manufacturing a display device using the same according to an exemplary embodiment of the present disclosure will be described in detail with reference to the accompanying drawings.

[0038] Figure 1 is a plan view of a display device according to an exemplary embodiment of the present disclosure. In Figure 1 For ease of explanation, only the display panel PN and a plurality of pixels PX among various components of the display device 100 are shown.

[0039] The display panel PN is a component for displaying an image and includes a display area AA and a non-display area NA.

[0040] The display panel PN includes a display area AA and a non-display area NA.

[0041] 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 pixel 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.

[0042] The non-display area NA is an area that does not display an image and is an area where various lines, a driver IC, etc. for driving the pixels PX provided in the display area AA are provided. For example, various driver ICs such as a gate driver IC and a data driver IC may be provided in the non-display area NA.

[0043] Although the non-display area NA is shown surrounding the display area AA in Figure 1 , the non-display area NA may be an area extending from one side of the display area AA, but is not limited thereto.

[0044] A plurality of pixels PX are provided in the display area AA of the display panel PN. Each of the plurality of pixels PX may include a plurality of sub-pixels. The plurality of sub-pixels are individual 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 red sub-pixels, green sub-pixels, and blue sub-pixels, but are not limited thereto, and the plurality of pixels PX may further include white sub-pixels.

[0045] The light-emitting diodes provided in a plurality of corresponding sub-pixels may be light-emitting diodes that emit light of the same color or light-emitting diodes that emit light of different colors. For example, when a plurality of corresponding light-emitting diodes emit light of different colors, a part of the plurality of light-emitting diodes may be red light-emitting diodes that emit red light, another part of the plurality of light-emitting diodes may be green light-emitting diodes that emit green light, and the remaining part of the plurality of light-emitting diodes may be blue light-emitting diodes that emit blue light. In addition, a combination of light from the red light-emitting diodes, green light-emitting diodes, and blue light-emitting diodes can achieve various colors of light including white light.

[0046] Moreover, 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 types and numbers of light-emitting diodes provided in the plurality of sub-pixels constituting the pixel PX may be configured differently according to embodiments, but are not limited thereto.

[0047] The plurality of pixels PX may be provided at equal distances. The plurality of pixels PX may be provided 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 adjacent pixel PX 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.

[0048] Hereinafter, Figure 2 a more detailed description will be given of the plurality of pixels PX.

[0049] Figure 2 is a schematic cross-sectional view of sub-pixels of a plurality of pixels constituting a display device according to an exemplary embodiment of the present disclosure.

[0050] Referring to Figure 2 , the substrate 110 is a support 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 flexible material.

[0051] A driving transistor 120 is provided 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.

[0052] The gate electrode 121 is disposed on the substrate 110. The gate electrode 121 may be formed of a conductive material such as copper (Cu), aluminum (Al), molybdenum (Mo), titanium (Ti), or an alloy thereof, but is not limited thereto.

[0053] 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.

[0054] 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, polycrystalline silicon, etc., but is not limited thereto.

[0055] A source electrode 123 and a 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 is not limited thereto.

[0056] Meanwhile, in the present disclosure, the driving transistor 120 is shown as a driving transistor 120 having a structure in which the gate electrode 121 is disposed at the bottom, the active layer 122 is disposed on the gate electrode 121, and the source electrode 123 and the drain electrode 124 are disposed on the active layer 122, but the present disclosure is not limited thereto.

[0057] 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 the plurality of light-emitting diodes LED of the 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.

[0058] 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 above 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 photoacrylic.

[0059] 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. Meanwhile, althoughFigure 2 It is shown that a light-emitting diode LED is disposed on a patterned first insulating layer 112, but the light-emitting diode LED may be disposed on the first insulating layer 112 that is not patterned and has a flat upper surface, but is not limited thereto.

[0060] When a plurality of light-emitting diodes LEDs are a plurality of LEDs, they may be formed in 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, and the n electrode NE and the p electrode PE are horizontally disposed on both sides of the light-emitting layer EL. The vertical type LED includes an n electrode NE and a p electrode PE, and the n electrode NE and the p electrode PE are disposed 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 disposed 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 disposed above the light-emitting layer EL. Hereinafter, a description will be made on the assumption that a plurality of light-emitting diodes LEDs are LEDs having a lateral structure, but the type of the plurality of light-emitting diodes LEDs is not limited thereto.

[0061] 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 LEDs may be formed on a wafer formed of a material such as sapphire, and then, the plurality of light-emitting diodes LEDs may be transferred to the display panel PN provided with the driving transistor 120 and various lines.

[0062] 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.

[0063] 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 an n-type or p-type impurity into gallium nitride (GaN). For example, the p-type semiconductor layer PL may be a layer formed by implanting a p-type impurity into gallium nitride, and the n-type semiconductor layer NL may be a layer formed by implanting an n-type impurity 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.

[0064] 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 can 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 can have a single-layer or multi-quantum well (MQW) structure. For example, the light-emitting layer EL can be formed of indium gallium nitride (InGaN) or gallium nitride (GaN), but is not limited thereto.

[0065] 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 can be electrically connected to the p-type semiconductor layer PL, and the n-electrode NE can be electrically connected to the n-type semiconductor layer NL.

[0066] A second insulating layer 113 is disposed on the light-emitting diode LED and the first insulating layer 112. The second insulating layer 113 can be disposed on a plurality of light-emitting diodes LED to protect the plurality of light-emitting diodes LED. The second insulating layer 113 can be formed of an organic material such as benzocyclobutene or acrylate, but is not limited thereto.

[0067] A first connection electrode CE1 and a second connection electrode CE2 are disposed on the second insulating layer 113. The first connection electrode CE1 can be electrically connected to the driving transistor 120 and the light-emitting diode LED through a contact hole in the first insulating layer 112 and the second insulating layer 113. For example, the first connection electrode CE1 can be electrically connected to the leakage electrode 124 of the driving transistor 120 and the p-electrode PE of the light-emitting diode LED. The first connection electrode CE1 can 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 can be electrically connected to the common line CL and the light-emitting diode LED through a contact hole in the first insulating layer 112 and the second insulating layer 113. For example, the second connection electrode CE2 can be electrically connected to the common line CL and the n-electrode NE of the light-emitting diode LED. The second connection electrode CE2 can 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 can 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 shocks. The protective layer 114 can 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 also be provided, and the reflective layer is provided to overlap with the plurality of light-emitting diodes LEDs. The reflective layer is provided to overlap with the plurality of light-emitting diodes LEDs, and can reflect the light emitted from the plurality of light-emitting diodes LEDs to the outside of the display device 100 and improve the light-emitting efficiency of the display device 100.

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

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

[0073] First, referring to Figure 3 , a primary transfer process is performed so that the plurality of light-emitting diodes LEDs 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 LEDs 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 LEDs from the wafer 200 to the donor substrate 300 and from the donor substrate 300 to the display panel PN.

[0074] Hereinafter, first, reference will be made to Figure 3 and Figures 4A to 4F describe the primary transfer process.

[0075] Refer to simultaneouslyFigure 3 and Figure 4A , the wafer 200 is a substrate formed with a plurality of light emitting diodes LED. Materials such as gallium nitride (GaN) or indium gallium nitride (InGaN) that constitute the plurality of light emitting diodes LED are formed on the wafer 200 to grow a crystal layer, the crystal layer is cut into individual chips, and electrodes are formed thereon, whereby a plurality of light emitting diodes LED can be formed. The wafer 200 can 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 can be defined as a rigid substrate.

[0076] In this case, a plurality of light emitting diodes LED that emit light of the same color can be formed on one wafer 200, or a plurality of light emitting diodes LED that emit light of different colors can be formed. Hereinafter, a description will be made on the assumption that a plurality of light emitting diodes LED that emit light of the same color 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 provided outside the active region 200A is a region where one or more dams DM and a plurality of alignment keys AK are provided.

[0078] A plurality of light emitting diodes LED are provided in the active region 200A. A plurality of light emitting diodes LED can be formed by forming an epitaxial layer on the wafer 200 and then patterning the epitaxial layer. Specifically, a plurality of light emitting diodes LED can be formed by growing materials that form an n-type semiconductor layer NL, a light emitting layer EL, and a p-type semiconductor layer PL that constitute 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] The plurality of light emitting diodes LED can be set at a second distance D2. The second distance D2 can be the distance from the center of one light emitting diode LED among the plurality of light emitting diodes LED to the center of another adjacent light emitting diode LED. In addition, the second distance D2 can be a distance less than the first distance D1, that is, the distance between the plurality of pixels PX of the display panel PN.

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

[0081] The first alignment key AK1 is a component 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 a 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 can be aligned and made parallel by aligning the first alignment key AK1 of the wafer 200 with the alignment protrusion 332 of the donor substrate 300.

[0082] For example, the first alignment key AK1 can be the following metal pattern, which is provided between a plurality of dams DM in the outer region 200B, or formed on the upper portion or the lower portion of the plurality of dams DM. Therefore, the wafer 200 and the donor substrate 300 can be aligned by visually detecting the first alignment key AK1. In this case, even when the first alignment key AK1 is formed on the dams DM which will be described later, since the first alignment key AK1 is a kind of metal pattern, the step generated between the wafer 200 and the donor substrate 300 by the first alignment key AK1 can be negligible. Therefore, the first alignment key AK1 can be formed regardless of the position of the dams 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 a plurality of light-emitting diodes LED of the wafer 200 are transferred to the donor substrate 300, the second alignment key AK2 can 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 can be matched.

[0084] The first alignment key AK1 and the second alignment key AK2 can be formed together when forming a plurality of light-emitting diodes LED, or can 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 can be formed of at least a part of the same material as the material constituting the plurality of light-emitting diodes LED. However, the materials and forming processes of the first alignment key AK1 and the second alignment key AK2 can be configured differently according to the design, but are not limited thereto.

[0085] The first alignment key AK1 and the second alignment key AK2 can 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 region 200B, the shapes or sizes of the first alignment key AK1 and the second alignment key AK2 can be configured differently. For example, the size of the first alignment key AK1 can 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 disposed in the outer region 200B. The dam DM is a component that improves the adhesion to 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 leaving a part of the epitaxial layer overlapping with the outer region 200B without patterning during the process of patterning the epitaxial layer into a plurality. Therefore, the height of the dam DM may be substantially equal to the height of the plurality of light emitting diodes LED.

[0087] Meanwhile, considering the maximum offset distance between the wafer 200 and the donor substrate 300 and the width of the region where a plurality of dam protrusions 335 of the donor substrate 300 are provided, the minimum width of the dam DM can be designed. 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 between the donor substrate 300 and the wafer 200 may be slightly changed. For example, the bonding position between the donor substrate 300 and the wafer 200 may vary within a third distance D3, which is the distance between a plurality of chip protrusions 331 of the donor substrate 300 to be described later. At this time, at least a part of the dam DM may contact a 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 for at least a part of the dam DM to 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 maximum offset distance between the donor substrate 300 and the wafer 200, such as the third distance D3. If the minimum width of the dam DM is less than or equal to the third distance D3, it may be difficult for at least a part of the dam DM 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 maximum offset distance 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 can be ensured during the transfer process.

[0088] The distance between the dam DM in the outer region 200B and the light-emitting diode LED disposed at the outermost part 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 part 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 can be minimized, which will be described later with reference to Figure 4E Description.

[0089] Meanwhile, although Figure 4A it is shown that the dam DM is disposed adjacent to the four corresponding sides of the active region 200A, 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 the part where structures such as a plurality of alignment keys AK are formed and may be integrally formed. However, the present disclosure is not limited thereto.

[0090] Meanwhile, 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 the process for the plurality of light-emitting diode LEDs, the second alignment key AK2 may also be patterned together with the epitaxial layer when patterning the epitaxial layer for forming the plurality of light-emitting diode LEDs. 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 sufficiently ensuring the region for forming the dam DM, the second alignment key AK2 may be formed outside the dam DM. Therefore, the second alignment key AK2 may be disposed at a distance equal to or greater than the minimum width of the dam DM from the active region 200A, for example, the third distance D3.

[0091] Referring to 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 the bending of the resin layer 330. The base layer 310 may be disposed below 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] The resin layer 330 is disposed on the base layer 310. The resin layer 330 may support the plurality of chip protrusions 331, to which a plurality of light-emitting diodes LEDs 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 the plurality of chip protrusions 331 are provided. The transfer region 330A is a region where the plurality of chip protrusions 331 to which the plurality of light-emitting diodes LEDs are attached are provided, and may be set to overlap at least a part of the wafer 200 or the display panel PN during the transfer process.

[0095] The non-transfer region 330B is a region where the plurality of alignment protrusions 332 and the 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 on which the plurality of light-emitting diodes LEDs are provided, and may be formed to extend from one surface of the resin layer 330. The plurality of chip protrusions 331 may be integrally formed 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 is not limited thereto.

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

[0098] In this case, the plurality of chip protrusions 331 may be disposed 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 (LEDs) 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 (LEDs) of the wafer 200. In this case, only some of the plurality of light emitting diodes (LEDs) disposed 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, the odd-numbered light emitting diodes (LEDs) or the even-numbered light emitting diodes (LEDs) in a row may be selectively transferred to the plurality of chip protrusions 331.

[0099] In addition, the third distance D3 can be N times or 1 / N times the first distance D1, where the first distance D1 is the distance between multiple 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 adjacent chip protrusion 331 can be N times or 1 / N times the pixel pitch. The distance between multiple 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 is changed so that multiple light-emitting diodes LED can be transferred to a donor substrate 300. Considering the third distance D3 as the distance between multiple chip protrusions 331 and the first distance D1 as the pixel pitch, multiple light-emitting diodes LED disposed on multiple 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 multiple chip protrusions 331, multiple light-emitting diodes LED on multiple 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 multiple chip protrusions 331, multiple light-emitting diodes LED on only the odd-numbered chip protrusions 331 or the even-numbered chip protrusions 331 among multiple chip protrusions 331 arranged in the same row are transferred to adjust the pixel pitch. However, the arrangement of multiple chip protrusions 331 and the distance therebetween can be changed differently according to the design, but it is not limited thereto.

[0100] The size of multiple chip protrusions 331 can be larger than the size of multiple light-emitting diodes LED. Since the size of the upper surface of multiple chip protrusions 331 is formed to be larger than the size of multiple light-emitting diodes LED, multiple light-emitting diodes LED can be placed on multiple chip protrusions 331 even if there is an alignment error between the donor substrate 300 and the wafer 200. Therefore, considering the alignment error between the wafer 200 and the donor substrate 300, the size of the upper surface of multiple chip protrusions 331 can be formed to be larger than the size of multiple light-emitting diodes LED.

[0101] Multiple alignment protrusions 332 and multiple dam protrusions 335 are provided in the non-transfer region 330B.

[0102] Multiple alignment protrusions 332 include multiple first alignment protrusions 333 and multiple 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 can be arranged to correspond to the first alignment keys AK1 of the wafer 200. For example, the alignment and parallelism of the wafer 200 and the donor substrate 300 can be matched by aligning the first alignment keys 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 keys AK1 can have different shapes or sizes for easy identification. For example, either one of the first alignment protrusions 333 and the first alignment keys AK1 can have an annular shape with a hole in the middle, and the other of the first alignment protrusions 333 and the first alignment keys AK1 can have a circular shape overlapping the hole. Figure 4A and Figure 4B shows that the first alignment keys AK1 of the wafer 200 and the first alignment protrusions 333 of the donor substrate 300 have a circular shape, but the shapes of the first alignment keys AK1 and the first alignment protrusions 333 are not limited thereto.

[0104] The second alignment protrusions 334 can be arranged to correspond to the second alignment keys AK2 of the wafer 200. For example, two second alignment protrusions 334 can be provided in each of the non-transfer region 330B above the transfer region 330A and the non-transfer region 330B below the transfer region 330A. After aligning the wafer 200 and the donor substrate 300 by aligning the first alignment keys AK1 of the wafer 200 and the first alignment protrusions 333 of the donor substrate 300, a plurality of light-emitting diodes LED of the wafer 200 can be transferred to the plurality of chip protrusions 331 of the donor substrate 300, and the second alignment keys AK2 of the wafer 200 can be transferred to the second alignment protrusions 334. In this case, the second alignment keys AK2 transferred to the donor substrate 300 can be used to align the display panel PN and 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 contact 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 the wafer 200 and the donor substrate 300 are bonded, when a plurality of light emitting diodes LEDs are transferred onto the donor substrate 300, an impact may be applied to the donor substrate 300 while the plurality of light emitting diodes LEDs are moving onto the donor substrate 300. When an impact is applied to the donor substrate 300, the positions or shapes of the plurality of chip protrusions 331 in the transfer area 330A and the resin layer 330 may be deformed. At this time, the plurality of dam protrusions 335 provided in the non-transfer area 330B surrounding the transfer area 330A can maintain the bonding state with the wafer 200, and minimize the deformation of the plurality of chip protrusions 331 and the resin layer 330 in the transfer area 330A. In addition, the plurality of dam protrusions 335 can contact one or more dams DM of the wafer 200 to maintain the bonding state between the wafer 200 and the donor substrate 300.

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

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

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

[0109] Moreover, 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 joined to each other. This will be described in detail 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 LEDs may be directly transferred onto the resin layer 330. That is, the donor substrate 300 may not include separate chip protrusions 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 LEDs, but is not limited thereto. Hereinafter, for ease of description, a description will be made on the assumption that the donor substrate 300 includes a plurality of chip protrusions 331 and a plurality of light-emitting diodes LEDs are respectively transferred onto the plurality of chip protrusions 331.

[0111] An adhesive layer 320 is provided between the resin layer 330 and the base layer 310. The adhesive layer 320 joins 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 the material constituting the resin layer 330 on the base layer 310 and then curing it. In this case, since the resin layer 330 can be attached to the base layer 310 even without providing the adhesive layer 320, the adhesive layer 320 may be omitted according to the design, but is not limited thereto.

[0113] Next, refer to together Figure 4C, a wafer 200 having a plurality of light emitting diodes (LEDs) and a donor substrate 300 are placed into a processing apparatus. Then, the wafer 200 and the donor substrate 300 placed in the processing apparatus are aligned. The wafer 200 and the donor substrate 300 can be aligned in a state where the plurality of LEDs on the wafer 200 and the plurality of chip protrusions 331 of the donor substrate 300 face each other. 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, in step S110, the wafer 200 and the donor substrate 300 are bonded together. The wafer 200 and the donor substrate 300 can be bonded to each other such that the plurality of LEDs in the active region 200A of the wafer 200 correspond 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 can be bonded to each other such 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 such 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 bonded together uniformly. For example, the dam DM surrounding the active region 200A of the wafer 200 is bonded to the plurality of dam protrusions 335 of the donor substrate 300 such that the entire wafer 200 and the entire donor substrate 300 can be bonded to each other uniformly. If the dam DM is formed only in 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 bond the entire surfaces of the wafer 200 and the donor substrate 300 uniformly. In this case, bonding defects may occur between the plurality of LEDs of the wafer 200 and the plurality of chip protrusions 331 of the donor substrate 300. Therefore, by forming a plurality of dams DM in the entire outer region 200B of the wafer 200, the adhesiveness between the wafer 200 and the donor substrate 300 can be uniformly improved, and the bonding defects between the plurality of LEDs and the plurality of chip protrusions 331 can 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 retention 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 protrusions 335 are formed to have a size corresponding to that of the dam DM, even if the adhesiveness between the wafer 200 and the donor substrate 300 increases due to an increase in the contact area between the dam DM and the dam protrusions 335, a non-bonded region may be generated due to air retention between the dam DM and the dam protrusions 335. Therefore, the 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 protrusions 335 provided above or below the transfer region 330A may form an air passage extending in the column direction, and the dam protrusions 335 provided on the left or right side of the transfer region 330A may form an air passage extending in the row direction. Therefore, by providing 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 the region where the wafer 200 and the donor substrate 300 are not bonded due to air retention can be reduced.

[0117] Next, in step S120, a 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 arranged to face each other, laser can be selectively irradiated only to the light-emitting diodes LED among the plurality of light-emitting diodes LED to be transferred to the donor substrate 300. The light-emitting diodes LED irradiated with laser can be separated from the wafer 200 and bonded to the plurality of chip protrusions 331 of the donor substrate 300.

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

[0119] Meanwhile, at least some of the multiple second alignment keys AK2 of the wafer 200 can also be transferred to the donor substrate 300. In a state where the wafer 200 and the donor substrate 300 are arranged to face each other, a laser can be selectively irradiated onto only some of the multiple second alignment keys AK2 that are to be transferred to the donor substrate 300. Additionally, the second alignment keys AK2 irradiated with the laser can 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 multiple second alignment keys AK2 are arranged to deviate from their original positions on the multiple second alignment protrusions 334, the multiple light-emitting diodes (LEDs) that maintain a constant distance from the multiple second alignment keys AK2 can also be arranged to deviate from their original positions on the multiple chip protrusions 331. Therefore, the positions of the multiple light-emitting diodes (LEDs) can be easily identified through the second alignment keys AK2. However, the second alignment keys AK2 may not be transferred together with the multiple light-emitting diodes (LEDs), but the present disclosure is not limited thereto.

[0121] Next, referring to Figure 4D and Figure 4E , after the multiple light-emitting diodes (LEDs) of the wafer 200 are transferred to the donor substrate 300, in step S130, the wafer 200 and the donor substrate 300 are separated from each other.

[0122] Referring to Figure 4D, the wafer 200 and the donor substrate 300 in the bonded state can be carried on the platform ST. The wafer 200 and the donor substrate 300 in the bonded state can be located between the platform ST and the head HD. The wafer 200 can be arranged to correspond to the head HD, and the donor substrate 300 can be arranged to correspond to the platform ST.

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

[0124] Then, in step S131, a part of the outermost portion of the donor substrate 300 is physically fixed to the platform ST. One edge among the plurality of edges of the donor substrate 300 or at least one of the four corners of the donor substrate 300 can be fixed to the platform ST using the 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 can move on the platform ST. For example, one edge among the outermost portions of the donor substrate 300 can be fixed to the platform ST by a gripper. For example, two adjacent corner portions among the outermost portions of the donor substrate 300 can be fixed to the platform ST by a gripper. The platform ST may not vacuum-adsorb the donor substrate 300, and the platform ST and the donor substrate 300 can 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 can be fixed to the head HD. For example, the entire one surface of the wafer 200 can be fixed to the head HD by a vacuum adsorption method, or can be fixed to the head HD by a fixing member. In this case, the head HD and the wafer 200 can be vacuum-adsorbed by moving the platform ST towards the head HD, or the head HD and the wafer 200 can be vacuum-adsorbed by moving the head HD towards 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, a part of which 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 can be moved in the Z-axis direction, or both the head HD and the stage ST can 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 fixed to the stage ST only at its edges or corners, the remaining portion thereof that is not fixed to the stage ST and is thus configured to be movable can move 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 where the entire one surface of the wafer 200 is fixed to the head HD and only a part 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 where they are separated row by row (hereinafter, it is referred to as "separated row by row").

[0128] For example, when the wafer 200 and the head HD are moved 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 can move in the Z-axis direction together with the wafer 200 and the head HD. First, when the wafer 200 and the head HD start to move in the Z-axis direction, the right edge of the donor substrate 300 that cannot move together with the wafer 200 can be separated first. And, as the head HD and the wafer 200 gradually move away from the donor substrate 300, starting from a part adjacent to the right edge of the donor substrate 300, the donor substrate 300 can be sequentially separated from the wafer 200. 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 can be completed. Therefore, the plurality of light-emitting diodes LED bonded to the plurality of chip protrusions 331 of the donor substrate 300 can 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 platform ST moves together with the wafer 200 during the separation process, is lifted from the platform ST, and can be placed on the platform ST when the separation is completed. 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 highly resistant to vertical impact, the possibility of transfer defects of the plurality of light-emitting diodes LED is low even if the donor substrate 300 is lifted from the platform ST during the process.

[0130] Also, in order to reduce interference between the dam DM of the wafer 200 and the light-emitting diodes LED provided 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 diodes LED can 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 adjacent light-emitting diode LED. As described above, when the wafer 200 and the donor substrate 300 are separated, the plurality of light-emitting diodes LED can 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, interference may occur between the dam DM and the light-emitting diodes LED at the outermost portion transferred to the donor substrate 300 during the process of sequentially separating the dam DM and the light-emitting diodes LED at the outermost portion of the active region 200A of the wafer 200. In the case of the 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, interference between the light-emitting diodes LED at the outermost portion and the dam DM may not occur. However, in the LED transfer method according to an exemplary embodiment of the present disclosure and the manufacturing method of the display device 100 using the same, since the wafer 200 and the donor substrate 300 are separated by a row-by-row separation method, interference may occur between the dam DM and the light-emitting diodes 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 in the outer region 200B of the wafer 200 and the plurality of light-emitting diodes LED in the active region 200A so that 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 part of the outermost portion of the donor substrate 300 is fixed to the stage ST by a vacuum adsorption method instead of physical fixing, it may be disadvantageous in terms of process time and throughput. In the case of partially vacuum-adsorbing the edge of the donor substrate 300, row-by-row separation may be feasible. However, when the separation speed of the wafer 200 and the donor substrate 300 increases, since the speed and 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 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 throughput, so a part of the outermost portion of the donor substrate 300 can be physically fixed to the stage ST.

[0132] Referring to Figure 4F , through one transfer process, multiple light-emitting diodes LED can be disposed on the donor substrate 300. In this case, the multiple light-emitting diodes LED disposed on the donor substrate 300 can be radially disposed around one light-emitting diode LED' among the multiple light-emitting diodes LED.

[0133] Specifically, one light-emitting diode LED' among the multiple light-emitting diodes LED can be disposed at the center of the chip protrusion 331 of the donor substrate 300. In addition, as the light-emitting diodes LED move away from one light-emitting diode LED' with one light-emitting diode LED' as the center, they can be disposed at intervals from the center of the chip protrusion 331. For example, the light-emitting diodes LED adjacent to one light-emitting diode LED' can be disposed adjacent to the center of the chip protrusion 331, and the light-emitting diodes LED disposed away from one light-emitting diode LED' can be disposed at intervals from the center of the chip protrusion 331. For example, some of the light-emitting diodes LED disposed to the right of one light-emitting diode LED' can be disposed to deviate to the right from the center of the chip protrusion 331, and some of the light-emitting diodes LED disposed above one light-emitting diode LED' can be disposed to deviate upward from the center of the chip protrusion 331.

[0134] In this case, a light-emitting diode LED' can 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, a light-emitting diode LED' can be one of the light-emitting diodes LED disposed in the left region with respect 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 can 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 can vary according to the fixed portion, and due to the change in the tension, a plurality of light-emitting diodes LED can be radially transferred onto 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 only one end of the donor substrate 300 is physically fixed, a plurality of light-emitting diodes LED disposed on the donor substrate 300 can be radially distributed.

[0135] Finally, referring to Figure 4G , by performing a secondary transfer process, a 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 a plurality of light-emitting diodes LED. For example, the display panel PN in which the driving transistors 120 and a plurality of lines are formed 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 processing apparatus. 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 can 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] Transfer a plurality of light emitting diodes LED and a second alignment key AK2 provided on the donor substrate 300 during the same process. Accordingly, the relative positions of the plurality of light emitting diodes LED and the second alignment key AK2 can be constant. Accordingly, when aligning the donor substrate 300 and the display panel PN based on the second alignment key AK2 having a constant relative position with respect to the plurality of light emitting diodes LED, the alignment accuracy capable of transferring the plurality of light emitting diodes LED to an appropriate position can be improved. Accordingly, 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 can 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 can 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 can be any one of the components formed on the display panel PN, or can be separately formed and provided. For example, when the alignment key is any one of the components formed on the display panel PN, a reflective layer overlapping the plurality of light emitting diodes LED among the components formed on the display panel PN, some of the lines among the plurality of lines configured to drive the plurality of light emitting diodes LED, etc. can be used as the alignment key. In addition, in the case where the alignment key is separately formed and provided, the alignment key can be a pattern or structure formed on the display panel PN, but is not limited thereto.

[0140] Next, after completing the alignment of the donor substrate 300 and the display panel PN, in step S140, the donor substrate 300 and the display panel PN are bonded together. 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, in step S160, the donor substrate 300 and the display panel PN are separated. In this case, the plurality of light emitting diodes LED radially distributed on the donor substrate 300 can 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 can be separated by a line-by-line separation method as in Figure 4E or can be separated in another manner. For example, the donor substrate 300 and the display panel PN can be separated by a surface separation method that separates their entire surfaces at once, and the donor substrate 300 and the display panel PN can be separated in various ways.

[0142] Therefore, the manufacturing process of the display device 100 can be completed by transferring a plurality of light emitting diodes (LEDs) from the wafer 200 to the donor substrate 300 at one time, and then transferring the transferred plurality of LEDs from the donor substrate 300 to the display panel PN at a second time.

[0143] Meanwhile, in some cases, as the donor substrate, a rigid substrate other than a flexible substrate can be used. For example, the donor substrate can 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 arrange the donor substrate over a large area due to thickness variations, 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 can be increased and damage to the LEDs can be minimized. Therefore, in the LED transfer method according to an exemplary embodiment of the present disclosure and the manufacturing method of the display device 100 using the same, a flexible substrate can be used as the donor substrate 300.

[0144] Meanwhile, when separating the wafer 200 from the donor substrate 300, which is a flexible substrate, by a surface separation method, transfer defects of a plurality of LEDs may occur. For example, in order to separate the donor substrate 300 and the wafer 200 by a surface separation method, the separation process can be performed in a state where the entire one surface of the donor substrate 300 is fixed to the platform ST and the entire one surface of the wafer 200 is fixed to the head HD. At this time, when the donor substrate 300, which is a flexible substrate, is fixed to the platform ST by a vacuum adsorption method, a wrinkling phenomenon may occur in the donor substrate 300, which may cause transfer defects of a plurality of LEDs. The wrinkling 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 surface separation or the external force caused by vacuum adsorption affects the LEDs of a small size, such that the LEDs may be transferred in a state where they are flipped or tilted, or may be transferred in a rotating state. Such transfer defects may randomly occur in the surface separation area SA, which may result in a reduction in yield and an increase in process costs.

[0145] On the other hand, in the LED transfer method according to an exemplary embodiment of the present disclosure, since only one end of the donor substrate 300 as a flexible substrate is physically fixed, external forces caused by vacuum adsorption can be minimized, and since the donor substrate 300 naturally separates from the wafer 200 row by row even during the separation process, surface tension can be minimized. Specifically, one end of the donor substrate 300 as a flexible substrate can be physically fixed to the stage 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 both 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 portion is not fixed, the remaining portion 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 the end of the donor substrate 300 fixed to the stage ST, the donor substrate 300 can be sequentially separated from the wafer 200. Therefore, during the process of separating the donor substrate 300 and the wafer 200, the external forces affecting the plurality of light-emitting diodes LED are reduced, and thus transfer defects of the plurality of light-emitting diodes LED can be minimized. Therefore, in the LED transfer method according to an exemplary embodiment of the present disclosure and the manufacturing method of the display device 100 using the same, the wafer 200 and the donor substrate 300 are separated by a row-by-row separation method, and thus transfer defects of the plurality of light-emitting diodes LED can be reduced.

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

[0147] Hereinafter, Figures 5A to 6B a comparison will be made between the LED transfer method according to an exemplary embodiment of the present disclosure and the LED transfer method according to a comparative embodiment.

[0148] Figure 5A and Figure 5BIt is a schematic diagram for explaining the LED transfer method according to Comparative Embodiment 1. Figure 6A and Figure 6B It is a schematic diagram for explaining the LED transfer method according to Comparative Embodiment 2. For ease of explanation, in 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 in which the donor substrate 300 and the wafer 200 are separated while 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 in which the donor substrate 300 and the wafer 200 are separated while only the two sides of the donor substrate 300 are fixed to the stage ST using the fixing member GR.

[0150] First, referring to Figure 5A and Figure 5B , in the LED transfer method according to Comparative Embodiment 1, with the entire one surface of the donor substrate 300 vacuum-adsorbed to the stage ST, the 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 the vacuum adsorption method.

[0151] Then, the wafer 200 and the donor substrate 300 can move 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 surfaces of the donor substrate 300 and the wafer 200 can be separated. That is, the entire surface of the resin layer 330 of the donor substrate 300 can be the surface separation region SA. Therefore, transfer defects of a plurality of light-emitting diodes LED may occur in the entire resin layer 330 provided with a plurality of chip protrusions 331 of the donor substrate 300.

[0152] Referring to Figure 6A and Figure 6B , in the LED transfer method according to Comparative Embodiment 2, only the 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 the vacuum adsorption method.

[0153] Then, the wafer 200 and the donor substrate 300 can be moved away from each other to separate the wafer 200 and the donor substrate 300. At this time, since only two edges of the donor substrate 300 are fixed to the platform ST and the entire one surface of the wafer 200 is fixed to the head HD, separation can 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 finally separated donor substrate 300 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, the partial region extending from the two edges may be a row-by-row separation region LA, and the remaining region in the middle thereof may be a surface separation region SA.

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

[0155] The exemplary embodiment of the present disclosure can also be described as follows:

[0156] According to an 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 part 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: placing 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 both the rigid substrate and the flexible substrate in a direction perpendicular to a 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] A plurality of light-emitting diodes provided on the flexible substrate may be radially provided around one light-emitting diode among the plurality of light-emitting diodes. This 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 of manufacturing a display device is provided. The method of 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 the donor substrate provided with the plurality of light-emitting diodes; transferring the 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 in a state where one surface of the wafer is fixed to a head and a part of the outermost portion of the donor substrate is fixed to a 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 of the outermost portion of the donor substrate to the platform by a gripper.

[0166] Separating the wafer and the donor substrate may further include: fixing at least one corner of the outermost portion of the donor substrate to the platform by a gripper.

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

[0168] Separating the wafer and the donor substrate may further include: moving the head, the platform, or both the head and the platform in the Z-axis direction. When the head, the platform, or both 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 platform, or both the head and the platform move in the Z-axis direction, at least a portion of the donor substrate may be spaced apart from the platform.

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

[0171] The donor substrate may include chip protrusions 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 among the plurality of light-emitting diodes transferred to the donor substrate and disposed on one side of the one light-emitting diode may be disposed to be offset to one side with respect to the center of the chip protrusion.

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

Claims

1. A wafer, comprising: A substrate, the substrate comprising an active region and an external region; A plurality of light-emitting diodes, the plurality of light-emitting diodes being arranged at regular intervals in the active region and configured to emit light of the same color; A plurality of dams, the plurality of dams being arranged in the external region and formed at the same height as the plurality of light-emitting diodes; A first alignment key, the first alignment key being arranged in the external region and having a metal pattern; And A second alignment key, the second alignment key being arranged in the external region, Wherein, the substrate is formed of any one of sapphire, silicon carbide (SiC), gallium nitride (GaN), and zinc oxide (ZnO), Wherein, the first alignment key and the second alignment key are formed of a material that is at least partially the same as the material constituting the plurality of light-emitting diodes.

2. The wafer according to claim 1, wherein The first alignment key is located in any one of the region between the plurality of dams, the upper part of the plurality of dams, and the lower part of the plurality of dams, Wherein, the second alignment key is arranged to be spaced apart from the plurality of dams.

3. The wafer according to claim 1, wherein, The second alignment key and the plurality of light-emitting diodes are configured to be separable from the substrate.

4. The wafer according to claim 1, wherein, The first alignment key and the second alignment key have different shapes or sizes.

5. The wafer according to claim 1, wherein, The minimum width of each of the plurality of dams is equal to or greater than the interval between the plurality of light-emitting diodes.

6. The wafer according to claim 1, wherein, The distance between the dam closest to the active region among the plurality of dams and the outermost light-emitting diode among the plurality of light-emitting diodes is equal to or greater than the distance between the plurality of light-emitting diodes.

7. The wafer according to claim 1, wherein, The plurality of dams are adjacent to each of the four sides of the active region.

8. The wafer according to claim 1, wherein, The plurality of dams are arranged between the active region and the second alignment key.

9. A donor substrate, comprising: A base layer; An adhesive layer provided on the base layer; A resin layer provided on the adhesive layer and having a transfer region and a non-transfer region; A plurality of chip protrusions provided in the transfer region; A plurality of alignment protrusions provided in the non-transfer region; And A plurality of dam protrusions provided in the non-transfer region and arranged to surround the transfer region.

10. The donor substrate according to claim 9, wherein, The base layer is formed of a material that is at least more rigid than the resin layer.

11. The donor substrate according to claim 9, wherein, The plurality of chip protrusions, the plurality of alignment protrusions, and the plurality of dam protrusions are integrally formed with the resin layer.

12. The donor substrate according to claim 11, wherein, The resin layer, the plurality of chip protrusions, the plurality of alignment protrusions, and the plurality of dam protrusions are formed of any one of polydimethylsiloxane (PDMS), polyurethane acrylate (PUA), polyethylene glycol (PEG), polymethyl methacrylate (PMMA), polystyrene (PS), epoxy resin, polyurethane resin, and acrylic resin.

13. The donor substrate according to claim 9, wherein, The size of each of the plurality of dam protrusions is larger than the size of each of the plurality of chip protrusions.

14. The donor substrate according to claim 9, wherein, The plurality of alignment protrusions include: A plurality of first alignment protrusions; and A plurality of second alignment protrusions, the plurality of second alignment protrusions having a different shape from the plurality of first alignment protrusions.

Images