Method of manufacturing a display device

Abstract

A method for manufacturing a display device according to an embodiment of the present application includes: a step of aligning a first wafer on which a plurality of first LEDs, a plurality of alignment keys, and a reference member are formed, with a supply substrate; a step of transferring the plurality of first LEDs and the reference member on the first wafer to the supply substrate; and a step of aligning a second wafer on which a plurality of second LEDs are formed, with the supply substrate based on the reference member. Accordingly, based on the reference member which maintains a constant distance from the plurality of first LEDs, it is possible to accurately align the relative positions between the plurality of second LEDs on the second wafer and the plurality of first LEDs on the supply substrate.

Description

Technical Field

[0001] This disclosure relates to a method for manufacturing a display device, and more specifically, to a method for manufacturing a display device that improves the alignment accuracy of a plurality of LEDs. Background Technology

[0002] Display devices used in computer monitors, TVs, mobile phones, etc. include self-emissive organic light-emitting display (OLED) devices and liquid crystal display (LCD) devices that require a separate light source.

[0003] As display devices are increasingly used in various fields such as computer monitors, TVs, and personal mobile devices, research has been conducted on display devices with large display areas and reduced size and weight.

[0004] Furthermore, in recent years, LED display devices have garnered significant attention as next-generation display devices. LEDs can comprise inorganic materials but exclude organic materials, thus offering superior reliability and a longer lifespan compared to liquid crystal displays or organic light-emitting diode displays. In addition, LEDs can exhibit rapid light emission, excellent luminous efficiency, superior shock resistance, excellent stability, and the ability to display high-brightness images. Summary of the Invention

[0005] Technical issues

[0006] This disclosure aims to provide a method for manufacturing a display device that improves the alignment accuracy of multiple LEDs in a primary transfer process of transferring multiple LEDs from a wafer to a supply substrate and a secondary transfer process of transferring multiple LEDs from the supply substrate to a display panel.

[0007] Furthermore, this disclosure aims to provide a method for manufacturing a display device that improves the alignment accuracy of multiple LEDs without being limited to the size of the multiple LEDs.

[0008] Furthermore, this disclosure aims to provide a method for manufacturing a display device with high resolution.

[0009] Furthermore, this disclosure aims to provide a method for manufacturing a display device that reduces process time and cost by simplifying the transfer process of the alignment key during a single transfer process.

[0010] Furthermore, this disclosure aims to provide a method for manufacturing a display device, which reduces process time and cost by shortening the secondary transfer process in which red LEDs, green LEDs, and blue LEDs, respectively corresponding to multiple sub-pixels, are transferred to a display panel in a single transfer.

[0011] Furthermore, this disclosure aims to provide a method for manufacturing a display device that improves productivity and output by simplifying primary and secondary transfer processes and precisely aligning multiple LEDs.

[0012] The purpose of this disclosure is not limited to the purposes mentioned above, and other purposes not mentioned above will be clearly understood by those skilled in the art through the following description.

[0013] Technical solution

[0014] One aspect of this disclosure provides a method for manufacturing a display device, comprising: aligning a first wafer on which a plurality of first LEDs, a plurality of alignment keys, and a reference member are disposed, with a supply substrate; transferring the plurality of first LEDs and the reference member on the first wafer to the supply substrate; and aligning a second wafer on which a plurality of second LEDs are disposed, with the supply substrate based on the reference member. Therefore, the relative positions between the plurality of second LEDs on the second wafer and the plurality of first LEDs on the supply substrate can be precisely aligned based on the reference member which maintains a predetermined interval with the plurality of first LEDs.

[0015] Another aspect of this disclosure provides a method for manufacturing a display device, comprising: aligning a first wafer on which a reference member and a plurality of first LEDs are disposed to a supply substrate; transferring the plurality of first LEDs and the reference member of the first wafer to the supply substrate; aligning a second wafer on which a plurality of second LEDs are disposed to the supply substrate based on the reference member transferred to the supply substrate; transferring the plurality of second LEDs of the second wafer to the supply substrate; aligning a third wafer on which a plurality of third LEDs are disposed to the supply substrate based on the reference member transferred to the supply substrate; and transferring the plurality of third LEDs of the third wafer to the supply substrate. Therefore, by aligning the second and third wafers based on the reference member first transferred to the supply substrate, the reduction in alignment accuracy of the plurality of LEDs caused by alignment errors in the process can be minimized.

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

[0017] Technical effect

[0018] According to this disclosure, the relative positions of multiple LEDs are aligned during the first transfer. Therefore, the spacing between the multiple LEDs can be precisely aligned, such that each LED corresponds to a multiple sub-pixel.

[0019] According to this disclosure, multiple micro-LEDs can be easily aligned.

[0020] According to this disclosure, it is possible to minimize the yield reduction caused by alignment errors in the process during the transfer of multiple LEDs.

[0021] According to this disclosure, it is possible to easily manufacture a display device with high resolution.

[0022] According to this disclosure, the first and second transfer steps are shortened. Therefore, it is possible to reduce the process time and cost of manufacturing display devices and to improve productivity.

[0023] The effects of this disclosure are not limited to those illustrated above, and this specification includes many more effects. Attached Figure Description

[0024] Figure 1 This is a plan view of a display device according to an exemplary embodiment of the present disclosure.

[0025] Figure 2 This is a schematic plan view of a plurality of pixels of a display device according to an exemplary embodiment of the present disclosure.

[0026] Figure 3 This is a schematic cross-sectional view of a plurality of sub-pixels of a display device according to an exemplary embodiment of the present disclosure.

[0027] Figure 4 This is a process flow diagram illustrating a method for manufacturing a display device according to an exemplary embodiment of the present disclosure.

[0028] Figures 5a to 5l This is a schematic process diagram illustrating a method for manufacturing a display device according to an exemplary embodiment of the present disclosure.

[0029] Figure 6 This is a process flow diagram illustrating a method for manufacturing a display device according to an exemplary embodiment of the present disclosure.

[0030] Figure 7 This is a schematic process diagram illustrating a method for manufacturing a display device according to an exemplary embodiment of the present disclosure.

[0031] Figure 8 and Figure 9 This is a diagram used to illustrate the alignment error range in the manufacturing method of the display device according to the comparative embodiment.

[0032] Figure 10 and Figure 11 This is a diagram illustrating the alignment error range in a manufacturing method of a display device according to an exemplary embodiment.

[0033] Figures 12a to 12e This is a process flow diagram illustrating a method for manufacturing a display device according to another exemplary embodiment of the present disclosure.

[0034] Figure 13 This is a process flow diagram illustrating a method for manufacturing a display device according to another exemplary embodiment of the present disclosure. Detailed Implementation

[0035] The advantages and features of this disclosure, as well as the methods for achieving these advantages and features, will become clear from reference to the exemplary embodiments described in detail below in conjunction with the accompanying drawings. However, this disclosure is not limited to the exemplary embodiments disclosed herein, but will be implemented in various forms. These exemplary embodiments are provided by way of example only so that those skilled in the art can fully understand the disclosure and scope of this disclosure. Therefore, this disclosure will be limited only by the scope of the appended claims.

[0036] The shapes, dimensions, ratios, angles, quantities, etc., illustrated in the accompanying drawings to describe exemplary embodiments of this disclosure are merely examples, and this disclosure is not limited thereto. Throughout the specification, similar reference numerals generally refer to similar elements. Furthermore, in the following description of this disclosure, detailed explanations of known related technologies may be omitted to avoid unnecessarily obscuring the subject matter of this disclosure. Terms such as “comprising,” “having,” and “consisting of” as used herein are generally intended to allow for the addition of other components, unless these terms are used in conjunction with the term “only.” Unless expressly stated otherwise, any reference to the singular may include the plural.

[0037] Even if not explicitly mentioned, components are interpreted as including the normal error range.

[0038] When using terms such as “above,” “over,” “below,” and “next to” to describe the positional relationship between two parts, one or more parts may be located between the two parts unless these terms are used in conjunction with the terms “immediately following” or “directly.”

[0039] When an element or layer is placed "on" another element or layer, the other layer or element can be directly inserted onto or between other elements.

[0040] Although the terms "first," "second," etc., are used to describe various components, these components are not bound by these terms. These terms are only used to distinguish one component from others. Therefore, the first component mentioned below may be the second component within the technical concept of this disclosure.

[0041] Throughout the specification, similar reference numerals typically refer to similar elements.

[0042] The dimensions and thicknesses of each component shown in the accompanying drawings are for illustrative purposes only, and this disclosure is not limited to the dimensions and thicknesses of the components shown.

[0043] Features of the various embodiments of this disclosure may be partially or wholly adhered to or combined with each other, and may be interlocked and operated in various technical ways, and the embodiments may be implemented independently or in conjunction with each other.

[0044] This disclosure will be described in detail below with reference to the accompanying drawings.

[0045] Figure 1 This is a plan view of a display device according to an exemplary embodiment of the present disclosure. Figure 1 For ease of description, only the display panel PN and the plurality of pixels PX among the various components of the display device 100 are shown.

[0046] The display panel PN is configured to display images and includes a display area AA and a non-display area NA.

[0047] The display area AA is the area where an image is displayed. Multiple pixels PX for displaying the image and circuitry units for driving the multiple pixels PX can be disposed within the display area AA. The circuitry units may include various thin-film transistors, capacitors, and lines for driving the pixels PX. For example, the circuitry units may include various components such as driving thin-film transistors, switching thin-film transistors, storage capacitors, gating lines, data lines, etc., but are not limited to these.

[0048] The non-display area NA is the region where no image is displayed. Within the non-display area NA, various lines and driver ICs are provided to drive the pixels PX located in the display area AA. For example, various driver ICs such as gating driver ICs and data driver ICs can be located in the non-display area NA.

[0049] In addition, although Figure 1 An example is shown where a non-display area NA surrounds a display area AA, but the non-display area NA can be an area extending from one side of the display area AA, but is not limited to this.

[0050] Multiple pixels (PX) are disposed in the display area AA of the display panel PN. Each of the multiple pixels (PX) may include multiple sub-pixels. Each of the multiple sub-pixels is a separate unit that emits light and is provided with a light-emitting diode and driving circuitry. For example, the multiple pixels (PX) may include red sub-pixels, green sub-pixels, and blue sub-pixels, but is not limited thereto. The multiple pixels (PX) may also include white sub-pixels.

[0051] In the following text, reference will be made to Figure 2 and Figure 3 Describe multiple pixels (PX) in detail.

[0052] Figure 2 This is a schematic plan view of a plurality of pixels PX of a display device according to an exemplary embodiment of the present disclosure. Figure 3 This is a schematic cross-sectional view of a plurality of sub-pixels of a display device according to an exemplary embodiment of the present disclosure. Specifically, Figure 3 This is a cross-sectional view of the first sub-pixel among a plurality of sub-pixels of a display device 100 according to an exemplary embodiment of the present disclosure.

[0053] Reference Figure 2 Each of the multiple pixels (PX) comprises multiple sub-pixels. Specifically, each of the multiple pixels (PX) may include a first sub-pixel, a second sub-pixel, and a third sub-pixel. The first sub-pixel, the second sub-pixel, and the third sub-pixel can emit light of different colors from each other.

[0054] In each pixel PX, the first, second, and third sub-pixels can be arranged in a row. Furthermore, the first, second, and third sub-pixels can be equidistant from each other. Based on the second sub-pixel, the first sub-pixel can be located on one side of the second sub-pixel, and the third sub-pixel can be located on the other side. Additionally, the interval between the first and second sub-pixels can be equal to the interval between the second and third sub-pixels. For example, in each pixel PX, the center of the first sub-pixel and the center of the second sub-pixel can be set with a first interval IN1, and the center of the first sub-pixel and the center of the third sub-pixel can be set with a second interval IN2, where the second interval IN2 is twice the first interval IN1.

[0055] LEDs (EDs) are disposed in each of multiple sub-pixels. Multiple LEDs (EDs) function as light-emitting diodes to emit light when a voltage is applied. The multiple LEDs (EDs) may include LEDs (EDs) emitting red, green, and blue light, and various colors of light, including white, can be achieved through combinations thereof.

[0056] The plurality of LEDs (EDs) include a first LED 130, a second LED 140, and a third LED 150. The first LED 130 is disposed in a first sub-pixel, the second LED 140 is disposed in a second sub-pixel, and the third LED 150 is disposed in a third sub-pixel.

[0057] Furthermore, when multiple LEDs (EDs) emit light of different colors, some of the LEDs (EDs) can be red LEDs emitting red light, some can be green LEDs emitting green light, and others can be blue LEDs emitting blue light. Since multiple LEDs (EDs) emit light of different colors, components such as light conversion layers can be omitted. In the following text, it is assumed that the first LED 130 is a red LED, the second LED 140 is a green LED, and the third LED 150 is a blue LED.

[0058] However, the plurality of LEDs (EDs) may also include white LEDs that realize white sub-pixels, and the type and number of LEDs (EDs) disposed in the plurality of sub-pixels forming pixel PX may vary depending on the implementation method.

[0059] Reference Figure 3 The substrate 110 is a support member for supporting other components of the display device 100 and may include an insulating material. For example, the substrate 110 may include glass, resin, etc. Furthermore, the substrate 110 may be configured to include a polymer or plastic, such as polyimide (PI), or may include a flexible material.

[0060] A driving transistor 120 is disposed on the substrate 110 of the display panel PN. The driving transistor 120 can 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.

[0061] The gate electrode 121 is disposed on the substrate 110. The gate electrode 121 may include, but is not limited to, a conductive material such as copper (Cu), aluminum (Al), molybdenum (Mo), titanium (Ti), or an alloy thereof.

[0062] A gate insulating layer 111 is disposed on the gate electrode 121. The gate insulating layer 111 is a layer used to insulate the gate electrode 121 and the active layer 122 and may include an insulating material. For example, the gate insulating layer 111 may be constructed from a single layer or multiple layers of silicon oxide (SiOx) or silicon nitride (SiNx), but is not limited thereto.

[0063] The active layer 122 may be disposed on the gate insulating layer 111. For example, the active layer 122 may include oxide semiconductor, amorphous silicon or polycrystalline silicon, but is not limited thereto.

[0064] The source electrode 123 and the drain electrode 124 are configured to be spaced apart from each other on the active layer 122. 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 include, but are not limited to, conductive materials such as copper (Cu), aluminum (Al), molybdenum (Mo), titanium (Ti), or alloys thereof.

[0065] Furthermore, in this specification, the driving transistor 120 is illustrated as having the following structure: a gate electrode 121 is disposed at the bottom, an active layer 122 is disposed on the gate electrode 121, and a source electrode 123 and a drain electrode 124 are disposed on the active layer 122, but is not limited thereto.

[0066] A common line CL is disposed on the gate insulating layer 111. The common line CL can transmit common power supplied from the outside to multiple LEDs (EDs) of multiple sub-pixels. The common line CL can include the same material and be formed by the same process as, for example, the source electrode 123 and drain electrode 124 of the driving transistor 120. However, the material and layout of the common line CL are not limited thereto.

[0067] A first insulating layer 112 is disposed on the driving transistor 120 and the common line CL. The first insulating layer 112 is disposed on the driving transistor 120 to protect the driving transistor 120. The first insulating layer 112 may include an organic material such as benzocyclobutene or photopropylene.

[0068] A first LED 130 is disposed on a first insulating layer 112. The first LED 130 can be electrically connected to the source electrode 123 or drain electrode 124 of a driving transistor 120 through contact holes formed in the first insulating layer 112. Furthermore, in Figure 3 In this embodiment, although the first LED 130 is illustrated as being disposed on a patterned first insulating layer 112, the first LED 130 may not be patterned and may be disposed on a first insulating layer 112 having a flat top surface, but is not limited thereto.

[0069] Multiple LEDs (EDs) can be configured with various structures, such as lateral, vertical, and flip-chip. Lateral LEDs include n-type and p-type electrodes horizontally positioned on either side of the light-emitting layer. Vertical LEDs include n-type and p-type electrodes positioned on and below the light-emitting layer. Flip-chip LEDs have essentially the same structure as lateral LEDs. Lateral LEDs include n-type and p-type electrodes horizontally positioned on the light-emitting layer, while flip-chip LEDs include n-type and p-type electrodes horizontally positioned below the light-emitting layer. In the following description, it is assumed that multiple LEDs (EDs) have a lateral structure, but the type of multiple LEDs (EDs) is not limited to this.

[0070] Furthermore, LEDs can be manufactured through a process separate from the TFT array process of the display panel PN. For example, multiple LEDs (EDs) can be formed on a wafer 200 made of a material such as sapphire and transferred to a display panel PN on which driving transistors 120 and various lines are disposed.

[0071] The first LED 130 includes a first p-type semiconductor layer 131, a first light-emitting layer 132, a first n-type semiconductor layer 133, a first p-type electrode 134, and a first n-type electrode 135.

[0072] A first n-type semiconductor layer 133 is disposed on the first insulating layer 112, and a first p-type semiconductor layer 131 is disposed on the first n-type semiconductor layer 133. The first p-type semiconductor layer 131 and the first n-type semiconductor layer 133 can be formed by implanting n-type or p-type impurities into gallium nitride (GaN). For example, the first p-type semiconductor layer 131 can be a layer formed by implanting p-type impurities into GaN, and the first n-type semiconductor layer 133 can be a layer formed by implanting n-type impurities into GaN, but is not limited thereto. The p-type impurities can be magnesium (Mg), zinc (Zn), beryllium (Be), etc., while the n-type impurities can be silicon (Si), germanium (Ge), tin (Sn), etc., but are not limited thereto.

[0073] A first light-emitting layer 132 is disposed between a first p-type semiconductor layer 131 and a first n-type semiconductor layer 133. The first light-emitting layer 132 can emit light by receiving holes and electrons from the first p-type semiconductor layer 131 and the first n-type semiconductor layer 133. The first light-emitting layer 132 can be a single-layer or multiple quantum well (MQW) structure. For example, the first light-emitting layer 132 can include indium gallium nitride (InGaN) or gallium nitride (GaN), but is not limited thereto.

[0074] A first p-type electrode 134 is disposed on a first p-type semiconductor layer 131, and a first n-type electrode 135 is disposed on a first n-type semiconductor layer 133. The first p-type electrode 134 can be electrically connected to the first p-type semiconductor layer 131, and the first n-type electrode 135 can be electrically connected to the first n-type semiconductor layer 133.

[0075] A second insulating layer 113 is disposed on the first LED 130 and the first insulating layer 112. The second insulating layer 113 may be disposed on multiple LEDs (EDs) to protect multiple LEDs (EDs). The second insulating layer 113 may include organic materials such as benzocyclobutene or photopropylene.

[0076] A first connecting electrode CE1 and a second connecting electrode CE2 are disposed on the second insulating layer 113. The first connecting electrode CE1 can be electrically connected to the driving transistor 120 and the first LED 130 through contact holes in the first insulating layer 112 and the second insulating layer 113. For example, the first connecting electrode CE1 can be electrically connected to the drain electrode 124 of the driving transistor 120 and the first p-type electrode 134 of the first LED 130. The first connecting electrode CE1 may include, but is not limited to, a transparent metal oxide such as indium tin oxide (ITO), indium gallium zinc oxide (IGZO), or indium gallium oxide (IGO).

[0077] The second connecting electrode CE2 can be electrically connected to the common line CL and the first LED 130 through contact holes in the first insulating layer 112 and the second insulating layer 113. For example, the second connecting electrode CE2 can be electrically connected to the common line CL and the first n-type electrode 135 of the first LED 130. The second connecting electrode CE2 may include, but is not limited to, a transparent metal oxide such as indium tin oxide (ITO), indium gallium zinc oxide (IGZO), or indium gallium oxide (IGO).

[0078] A buffer layer 114 is disposed on the first connecting electrode CE1 and the second connecting electrode CE2. The buffer layer 114 may be disposed on the entire surface of the display panel PN to protect the circuitry, including multiple LEDs (EDs) and driving transistors 120, from external impacts. The buffer layer 114 may include, for example, an optically clear adhesive (OCA) or an optically clear resin (OCR), but is not limited thereto.

[0079] Furthermore, although not shown in the accompanying drawings, a reflective layer may be provided that overlaps with the plurality of LEDs (EDs). Since the reflective layer overlaps with the plurality of LEDs (EDs), light emitted from the plurality of LEDs (EDs) can be reflected to the outside of the display device 100, thereby improving the light efficiency of the display device 100.

[0080] In the following text, reference will be made to Figures 4 to 7 A method for manufacturing a display device 100 according to an exemplary embodiment of the present disclosure is described.

[0081] Figure 4 This is a process flow diagram illustrating a method for manufacturing a display device according to an exemplary embodiment of the present disclosure. Figures 5a to 5l This is a schematic process diagram illustrating a method for manufacturing a display device according to an exemplary embodiment of the present disclosure. Specifically, Figure 4 This is a process flow diagram illustrating a single transfer process of transferring multiple LEDs (EDs) from wafer 200 to supply substrate 300. Figures 5a to 5l It is a schematic process diagram used to illustrate a single transfer process. Figure 5c , Figure 5f , Figure 5g , Figure 5i , Figure 5j and Figure 5k It is along Figure 5b The cross-sectional view taken by line AA′.

[0082] Multiple LEDs (EDs) on wafer 200 can be transferred to supply substrate 300 by performing a single transfer process, and multiple LEDs (EDs) on supply substrate 300 can be transferred to display panel PN by performing a second transfer process. Therefore, the manufacturing process of display device 100 can be completed by transferring multiple LEDs (EDs) from wafer 200 to supply substrate 300 and from supply substrate 300 to display panel PN. Here, in the manufacturing method of display device 100 according to an exemplary embodiment of the present disclosure, it is assumed that the reference member used for aligning supply substrate 300 with wafer 200 and aligning supply substrate 300 with display panel PN is the second alignment key AK2 transferred from first wafer 210 to supply substrate 300 together with first LED 130.

[0083] In the following text, reference will be made to Figure 4 and Figures 5a to 5l Describe a single transfer process S100.

[0084] Refer to together Figure 4 and Figure 5a Wafer 200 is a substrate on which multiple LEDs (EDs) are formed. A material such as gallium nitride (GaN) or indium gallium nitride (InGaN) is formed on wafer 200 to grow a crystal layer. The crystal layer is diced into individual chips and electrodes are formed to form multiple LEDs (EDs). Wafer 200 may include, but is not limited to, sapphire, silicon carbide (SiC), gallium nitride (GaN), zinc oxide (ZnO), etc.

[0085] In this case, multiple LEDs (EDs) emitting the same color of light or multiple LEDs (EDs) emitting different colors of light can be formed on a single wafer 200. In the following text, it is assumed that multiple LEDs (EDs) emitting the same color of light are formed on a single wafer 200.

[0086] Wafer 200 includes an active region 200A and an external region 200B. The active region 200A is the area where multiple LEDs (EDs) are formed, while the external region 200B, located outside the active region 200A, is the area where multiple alignment keys AK are formed.

[0087] The plurality of alignment keys AK includes a first alignment key AK1 and a second alignment key AK2. The first alignment key AK1 and the second alignment key AK2 can be disposed adjacent to the edge of the wafer 200 in the outer region 200B. However, the first alignment key AK1 and the second alignment key AK2 can be disposed at a location other than the edge of the wafer 200 according to the design, and the number of the first alignment key AK1 and the second alignment key AK2 can also be designed in various ways.

[0088] The first alignment key AK1 is a component used to align the wafer 200 and the supply substrate 300. The first alignment key AK1 is a mark used to adjust the alignment and parallelism between the wafer 200 and the supply substrate 300 when transferring a plurality of LEDs (EDs) from the wafer 200 to the supply substrate 300. For example, the alignment and parallelism between the wafer 200 and the supply substrate 300 can be adjusted by aligning the first alignment key AK1 of the wafer 200 with the alignment protrusion 332 of the supply substrate 300.

[0089] The second alignment key AK2 is a component used to align the supply substrate 300 and the display panel PN. When multiple LEDs (EDs) of the wafer 200 are transferred to the supply substrate 300, the second alignment key AK2 can be transferred to the supply substrate 300 along with the multiple LEDs (EDs). The alignment and parallelism between the supply substrate 300 and the display panel PN can then be adjusted using the second alignment key AK2 on the supply substrate 300.

[0090] The first alignment key AK1 and the second alignment key AK2 can be formed together when forming multiple LEDs (EDs), or they can be formed in a separate process from the multiple LEDs (EDs). If the first alignment key AK1 and the second alignment key AK2 are formed together with the multiple LEDs (EDs), then the first alignment key AK1 and the second alignment key AK2 can include at least some of the same materials as those used to form the multiple LEDs (EDs). However, the materials and forming processes of the first alignment key AK1 and the second alignment key AK2 can be configured in various ways according to the design, but are not limited thereto.

[0091] The shape and size of the first alignment key AK1 and the second alignment key AK2 can be configured in various ways. To identify the first alignment key AK1 and the second alignment key AK2 disposed in the external area 200B, the first alignment key AK1 may have a different shape or size than the second alignment key AK2. For example, the first alignment key AK1 may have a larger size than the second alignment key AK2, but is not limited thereto.

[0092] Reference Figure 5b The substrate 300 includes a base layer 310, an adhesive layer 320, a resin layer 330, a plurality of protrusions 331, and a plurality of alignment protrusions 332.

[0093] The base layer 310 is configured to support various components included in the supply substrate 300 and may comprise a material that is at least more rigid than the resin layer 330 to minimize bending of the resin layer 330. The base layer 310 may be disposed beneath the resin layer 330 to support the resin layer 330, a plurality of protrusions 331, and a plurality of alignment protrusions 332. For example, the base layer 310 may be configured to comprise a polymer or plastic and may comprise, but is not limited to, polycarbonate (PC) or polyethylene terephthalate (PET).

[0094] In addition, the marking pattern 340 and the orientation pattern 350 can be provided on the outer part of the base layer 310 facing the resin layer 330.

[0095] The identification pattern 340 is a pattern formed on the base layer 310 to identify the supply substrate 300. Multiple supply substrates 300 can be managed using a unique identification pattern 340 assigned to each supply substrate 300. The identification pattern 340 can be disposed on the upper or rear surface of the base layer 310 and can be formed by printing or laser engraving methods. For example, the identification pattern 340 can be an ID or barcode including numbers or characters, but is not limited thereto. Furthermore, in Figure 5b Although a single logo pattern 340 is illustrated as being formed on the lower left side of the supply substrate 300, the number and layout of the logo patterns are not limited thereto.

[0096] The orientation pattern 350 is a pattern formed on the base layer 310 to distinguish the orientation of the supply substrate 300. For example, when the supply substrate 300 is placed in the processing equipment, if the supply substrate 300 is placed in the opposite direction, the LED (ED) may be moved to a position different from the designed position, or defects may occur. Therefore, the orientation pattern 350 can be provided on any part of the base layer 310 to distinguish the orientation of the supply substrate 300. The orientation pattern 350 can be formed by printing or laser engraving, or by chamfering the edges of the base layer 310, but is not limited to these methods.

[0097] A resin layer 330 is disposed on the base layer 310. During the transfer process, the resin layer 330 can support multiple protrusions 331 to which multiple LEDs (EDs) are attached. The resin layer 330 may include a viscoelastic polymer resin. For example, the resin layer 330 may include, but is not limited to, polydimethylsiloxane (PDMS), polyurethane acrylate (PUA), polyethylene glycol (PEG), polymethyl methacrylate (PMMA), polystyrene (PS), epoxy resin, polyurethane resin, acrylic resin, etc.

[0098] The resin layer 330 includes a transfer region 330A and a non-transfer region 330B.

[0099] The transfer area 330A is a region having a plurality of protrusions 331. The transfer area 330A is a region having a plurality of protrusions 331 to which a plurality of LEDs (EDs) are attached. The transfer area 330A may be configured to overlap with at least a portion of the wafer 200 or the display panel PN during the transfer process.

[0100] The non-transfer region 330B is a region with multiple alignment protrusions 332. Multiple LEDs (EDs) of wafer 200 may not be transferred to the non-transfer region 330B, but the second alignment bond AK2 of wafer 200 may be transferred to the non-transfer region 330B.

[0101] The plurality of protrusions 331 may be protrusions 331 on which a plurality of LEDs (EDs) are disposed, and may extend from one surface of the resin layer 330. The plurality of protrusions 331 may be integrally formed with the resin layer 330, and may, like the resin layer 330, comprise a viscoelastic polymer material. For example, the plurality of protrusions 331 may comprise, but are not limited to, polydimethylsiloxane (PDMS), polyurethane acrylate (PUA), polyethylene glycol (PEG), polymethyl methacrylate (PMMA), polystyrene (PS), epoxy resin, polyurethane resin, acrylic resin, etc., and are not limited thereto.

[0102] Multiple LEDs (EDs) can be temporarily attached to the upper surface of multiple protrusions 331. Multiple LEDs (EDs) formed on wafer 200 can be transferred to the upper surface of multiple protrusions 331 and can remain temporarily attached to the upper surface of multiple protrusions 331 before being transferred to display panel PN.

[0103] In this case, the multiple protrusions 331 can be arranged at the same interval as the interval between the multiple sub-pixels. For example, when multiple LEDs (EDs) are transferred to the display panel PN, each LED (ED) is transferred to a different sub-pixel. If the multiple LEDs (EDs) transferred to the supply substrate 300 are transferred all at once, then the multiple LEDs (EDs) on the supply substrate 300 need to be arranged to correspond to a different sub-pixel. In this case, the multiple LEDs (EDs) transferred to the display panel PN all at once can be transferred to a different sub-pixel. However, the layout and spacing of the multiple protrusions 331 can vary depending on the design, but are not limited to this.

[0104] The multiple protrusions 331 can have a larger size than the multiple LEDs (EDs). The upper surface of the multiple protrusions 331 is formed to be larger than the multiple LEDs (EDs). Therefore, even if alignment errors occur between the supply substrate 300 and the wafer 200, the multiple LEDs (EDs) can be mounted on the multiple protrusions 331. Therefore, taking into account the alignment errors between the wafer 200 and the supply substrate 300, the upper surface of the multiple protrusions 331 can be formed to be larger than the multiple LEDs (EDs).

[0105] A plurality of alignment protrusions 332 are disposed in the non-transfer region 330B. The plurality of alignment protrusions 332 include a plurality of first alignment protrusions 333 and a plurality of second alignment protrusions 334.

[0106] Multiple first alignment protrusions 333 are used to align the wafer 200 and the supply substrate 300. The multiple first alignment protrusions 333 may correspond to the first alignment key AK1 of the wafer 200. For example, the alignment and parallelism between the wafer 200 and the supply substrate 300 can be adjusted by aligning the first alignment key AK1 of the first wafer 210 and the first alignment protrusions 333 of the supply substrate 300. In this case, the first alignment protrusions 333 may have a different shape or size than the first alignment key AK1 for easy identification. For example, either the first alignment protrusion 333 or the first alignment key AK1 may have an annular shape with a hole in the center, while the other may have a circular shape overlapping the hole. Figure 5a and Figure 5b The first alignment key AK1 of the wafer 200 and the first alignment protrusion 333 of the supply substrate 300 are shown to be circular, but the shapes of the first alignment key AK1 and the first alignment protrusion 333 are not limited to this.

[0107] The second alignment protrusion 334 may correspond to the second alignment key AK2 of the wafer 200. For example, after aligning the first alignment key AK1 of the wafer 200 and the first alignment protrusion 333 of the supply substrate 300 to align the wafer 200 and the supply substrate 300, a plurality of LEDs (EDs) of the wafer 200 may be transferred to a plurality of protrusions 331 of the supply substrate 300, and the second alignment key AK2 of the wafer 200 may be transferred to the second alignment protrusion 334 of the supply substrate 300. In this case, the second alignment key AK2 transferred to the supply substrate 300 may later be used to align the display panel PN with the supply substrate 300.

[0108] Furthermore, although not shown in the accompanying drawings, multiple protrusions in addition to the multiple alignment protrusions 332 can be further provided in the non-transfer region 330B. Specifically, in order to minimize the deformation of the resin layer 330 and the multiple protrusions 331 in the transfer region 330A caused by the impact applied to the supply substrate 300 during the transfer process, multiple protrusions can be further provided in the non-transfer region 330B. For example, when multiple LEDs (EDs) are transferred onto the supply substrate 300 after the wafer 200 is bonded to the supply substrate 300, the multiple LEDs (EDs) can impact the supply substrate 300 while moving onto the supply substrate 300. When an impact is applied to the supply substrate 300, the position or shape of the resin layer 330 and the multiple protrusions 331 in the transfer region 330A can change. In this case, the multiple protrusions in the non-transfer region 330B provided around the transfer region 330A can continue to be bonded to the wafer, and the deformation of the resin layer 330 and the multiple protrusions 331 in the transfer region 330A is minimized.

[0109] Furthermore, the multiple protrusions 331 may not be provided in the supply substrate 300, and the multiple LEDs (EDs) can be directly transferred onto the resin layer 330. That is, the supply substrate 300 may not include individual protrusions 331. The structure of the supply substrate 300 may vary depending on the shape, layout, and transfer method of the multiple LEDs (EDs), but is not limited thereto. In the following description, for ease of description, it is assumed that the supply substrate 300 includes multiple protrusions 331 and the multiple LEDs (EDs) are transferred to the multiple protrusions 331 respectively.

[0110] An adhesive layer 320 is disposed between the resin layer 330 and the base layer 310. The adhesive layer 320 bonds the resin layer 330 to the display panel PN. The adhesive layer 320 may include, but is not limited to, materials with adhesive properties, such as optically clear adhesive (OCA), pressure-sensitive adhesive (PSA), etc.

[0111] However, the adhesive layer 320 can be omitted depending on the design. For example, the resin layer 330 can be formed by directly applying the material forming the resin layer 330 onto the base layer 310 and then curing the material. In this case, since the resin layer 330 can be attached to the base layer 310 even without the adhesive layer 320, the adhesive layer 320 can be omitted depending on the design, but is not limited to this.

[0112] Refer to together Figures 5c to 5eA first wafer 210, on which a plurality of first LEDs 130 are formed, and a supply substrate 300 are placed into a process apparatus (S110). Then, the first wafer 210 and the supply substrate 300 in the process apparatus are aligned (S111). The first wafer 210 and the supply substrate 300 can be aligned when they are configured such that the plurality of first LEDs 130 on the first wafer 210 and the plurality of protrusions 331 on the supply substrate 300 face each other. Specifically, the first wafer 210 and the supply substrate 300 can be aligned by aligning the center of the first alignment key AK1 of the first wafer 210 with the center of the first alignment protrusion 333 of the supply substrate 300.

[0113] After alignment between the first wafer 210 and the supply substrate 300 is completed, a plurality of first LEDs 130 from the first wafer 210 are transferred to the supply substrate 300 (S112). With the first wafer 210 and the supply substrate 300 facing each other, the laser can selectively irradiate only the first LEDs 130 to be transferred to the supply substrate 300. The LEDs 130 irradiated by the laser can be separated from the first wafer 210 and then attached to a plurality of protrusions 331 on the supply substrate 300.

[0114] In this configuration, at least some of the plurality of second alignment keys AK2 on wafer 200 can also be transferred to supply substrate 300. With the first wafer 210 and supply substrate 300 facing each other, the laser can selectively irradiate only some of the plurality of second alignment keys AK2 to be transferred to supply substrate 300. The second alignment keys AK2 irradiated by the laser can then be separated from the first wafer 210 and attached to the second alignment protrusion 334 on supply substrate 300.

[0115] Reference Figure 5d After the transfer of multiple first LEDs 130 and second alignment keys AK2 is completed, some first LEDs 130 and some second alignment keys AK2 that are not transferred to the supply substrate 300 can remain on the first wafer 210. In addition, the first LEDs 130 and second alignment keys AK2 remaining on the first wafer 210 can be transferred to another supply substrate 300 and then transferred to the display panel PN.

[0116] Reference Figure 5eMultiple first LEDs 130 can be transferred to protrusions 331 of the multiple protrusions 331 of the supply substrate 300 that are located at positions corresponding to the first sub-pixel. The multiple first LEDs 130 can be LEDs (EDs) disposed in the first sub-pixel. Furthermore, the multiple protrusions 331 of the supply substrate 300 are disposed corresponding to the sub-pixel. Therefore, the multiple first LEDs 130 are only transferred to some of the protrusions 331 of the supply substrate 300 that are aligned with the first sub-pixel in the secondary transfer process described later. Therefore, the multiple first LEDs 130 can be transferred to the first sub-pixel of the display panel PN in one step.

[0117] Furthermore, the spacing between a specific first LED 130 and the second alignment key AK2 among the plurality of first LEDs 130 transferred to the supply substrate 300 is constant. Specifically, the spacing between the first LED 130 disposed on the first wafer 210 with the shortest distance and the specific second alignment key AK2, as well as the spacing between the first LED 130 disposed on the supply substrate 300 with the shortest distance and the specific second alignment key AK2, can be constant. For example, among the four second alignment keys AK2 transferred to the supply substrate 300, the second alignment key AK2 disposed at the upper left end and the first LED 130 disposed at the upper left end closest to that AK2 can have a spacing of D1 on the first wafer 210, and can also have a spacing of D1 on the supply substrate 300. Further, among the four second alignment keys AK2 transferred to the supply substrate 300, the second alignment key AK2 disposed at the upper right end and the first LED 130 disposed at the upper right end closest to that AK2 can have a spacing of D2 on the first wafer 210, and can also have a spacing of D2 on the supply substrate 300. In other words, when multiple first LEDs 130 and multiple second alignment keys AK2 are moved, the multiple second alignment keys AK2 can be moved at predetermined intervals with each of the first LEDs 130 which is set with the shortest distance.

[0118] Therefore, if the plurality of second alignment keys AK2 are set to deviate from their original positions on the plurality of second alignment protrusions 334, then the plurality of first LEDs 130, each at a predetermined interval from the plurality of second alignment keys AK2, can also be set to deviate from their original positions on the plurality of protrusions 331. Thus, the positions of the plurality of first LEDs 130 can be easily identified by the second alignment keys AK2.

[0119] After transferring a plurality of first LEDs 130 from the first wafer 210 to the supply substrate 300, the first wafer 210 and the supply substrate 300 are separated (S113), and the supply substrate 300 to which the first LEDs 130 have been transferred is discharged from the process equipment (S114).

[0120] Then, the supply substrate 300 on which the first LED 130 is disposed and the second wafer 220 on which a plurality of second LEDs 140 are formed are placed into the process equipment (S120). Thereafter, the second wafer 220 and the supply substrate 300 are aligned (S121), and the plurality of second LEDs 140 are transferred to the supply substrate 300 (S122).

[0121] Reference Figure 5f When the second wafer 220 and the supply substrate 300 are configured such that the plurality of second LEDs 140 on the second wafer 220 and the plurality of protrusions 331 on the supply substrate 300 face each other, the second wafer 220 and the supply substrate 300 can be aligned.

[0122] In this configuration, the first wafer 210 and the supply substrate 300 are aligned based on the first alignment key AK1 and the first alignment protrusion 333. However, the second wafer 220 and the supply substrate 300 may be aligned based on at least some of the second alignment keys AK2 that have been transferred from the first wafer 210 to the supply substrate 300.

[0123] Specifically, when the supply substrate 300, on which a plurality of first LEDs 130 and a plurality of second alignment keys AK2 are disposed, is aligned with the second wafer 220, they can be aligned based on one or more of the plurality of second alignment keys AK2 disposed on the supply substrate 300 and any component of the second wafer 220. For example, the second wafer 220 and the supply substrate 300 can be aligned based on the plurality of second alignment keys AK2 transferred from the first wafer 210 to the supply substrate 300 and the first alignment key AK1 or the second alignment key AK2 of the second wafer 220. Alternatively, the second wafer 220 and the supply substrate 300 can be aligned based on the plurality of second alignment keys AK2 transferred from the first wafer 210 to the supply substrate 300 and some of the plurality of second LEDs 140 of the second wafer 220.

[0124] As described above, the interval between the first LED 130 disposed on the supply substrate 300 and the second alignment key AK2 is constant, and therefore, the position of the first LED 130 can be identified by the second alignment key AK2. Therefore, when the second wafer 220 and the supply substrate 300 are aligned based on the second alignment key AK2 disposed on the supply substrate 300, the relative positions between the plurality of first LEDs 130 on the supply substrate 300 and the plurality of second LEDs 140 on the second wafer 220 can be aligned. For example, the plurality of first LEDs 130 and the plurality of second LEDs 140 on the supply substrate 300 can be transferred to the display panel PN at a first interval IN1, where the first interval IN1 is the interval between the plurality of sub-pixels on the supply substrate 300. When the plurality of second LEDs 140 are transferred to the supply substrate 300, the second wafer 220 and the supply substrate 300 can be aligned using the second alignment key AK2, which is disposed at a predetermined interval (i.e., the first interval IN1) with the plurality of first LEDs 130 on the supply substrate 300, as a reference member.

[0125] In this case, only the multiple second LEDs 140 can be transferred from the second wafer 220 to the supply substrate 300, but the multiple second alignment keys AK2 can be left untransferred. Since different masks or lasers are used for the multiple second LEDs 140 and the multiple second alignment keys AK2 in the transfer process, they cannot be transferred to the supply substrate 300 simultaneously, but can be transferred sequentially. If the multiple first LEDs 130, the multiple second LEDs 140, and the multiple third LEDs 150 are transferred to each supply substrate 300, the multiple second alignment keys AK2 can be transferred to each supply substrate 300 to align the display panel PN and the supply substrate 300. However, in the manufacturing method of the display device according to an exemplary embodiment of this disclosure, the multiple first LEDs 130, the multiple second LEDs 140, and the multiple third LEDs 150 are transferred to the same supply substrate 300, and the second alignment keys AK2 transferred along with the multiple first LEDs 130 are already provided on the supply substrate 300. Therefore, the second alignment keys AK2 of the second wafer 220 or the third wafer 230 can be left untransferred to the supply substrate 300. Therefore, the process time for transferring the second alignment key AK2 can be reduced.

[0126] Furthermore, by using a plurality of second alignment keys AK2 transferred to the supply substrate 300 as reference components for aligning the second wafer 220 and the supply substrate 300, the alignment accuracy of the plurality of LEDs (EDs) can be improved. This will be discussed later. Figures 8 to 11 Detailed description.

[0127] Furthermore, depending on the order in which the wafers 200 are used, the first alignment key AK1 can be omitted in some wafers 200. For example, after the first wafer 210 on which a plurality of first LEDs 130 are formed and the supply substrate 300 are aligned based on the first alignment key AK1, the plurality of first LEDs 130 and the second alignment key AK2 of the first wafer 210 can be transferred to the supply substrate 300, and the second wafer 220 on which a plurality of second LEDs 140 are formed can be aligned with the supply substrate 300 based on the second alignment key AK2 transferred to the supply substrate 300. In this case, the first alignment key AK1 can be omitted in the second wafer 220 and the third wafer 230. However, the plurality of first alignment keys AK1 can be provided in each of the plurality of wafers 200, regardless of the process order, but are not limited thereto.

[0128] Reference Figure 5g After the alignment between the second wafer 220 and the supply substrate 300 is completed, the second wafer 220 can be translated by a first gap IN1. After the second wafer 220 is translated by the first gap IN1, that is, the gap between the multiple sub-pixels, the multiple second LEDs 140 are transferred to the supply substrate 300.

[0129] If the second wafer 220 is not translated and the laser irradiates a position on the second wafer 220 that is the same as the position on the first wafer 210, then the plurality of second LEDs 140 can be transferred to the protrusions 331 on which the plurality of first LEDs 130 are disposed, and the plurality of first LEDs 130 and the plurality of second LEDs 140 can interfere with each other. Therefore, after the second wafer 220 is translated as the first interval IN1 between sub-pixels, the laser can irradiate the second wafer 220 to transfer the plurality of second LEDs 140 to the supply substrate 300. Furthermore, the second LEDs 140 irradiated by the laser can be detached from the second wafer 220 and attached to the plurality of protrusions 331 on the supply substrate 300.

[0130] Reference Figure 5h The plurality of second LEDs 140 can be transferred to the protrusions 331 of the plurality of protrusions 331 of the supply substrate 300 located at positions corresponding to the second sub-pixels. The plurality of second LEDs 140 can be LEDs (EDs) disposed in the second sub-pixels. Therefore, the plurality of second LEDs 140 can be transferred only to some of the protrusions 331 of the plurality of protrusions 331 disposed corresponding to the plurality of sub-pixels and aligned with the second sub-pixels.

[0131] After the second LEDs 140 of the second wafer 220 are transferred to the supply substrate 300, the second wafer 220 and the supply substrate 300 are separated (S123) and the supply substrate 300 to which the second LEDs 140 have been transferred is discharged from the process equipment (S124).

[0132] Then, the supply substrate 300 on which the first LED 130 and the second LED 140 are disposed, and the third wafer 230 on which a plurality of third LEDs 150 are formed are placed into the process equipment (S130). Thereafter, the third wafer 230 and the supply substrate 300 are aligned (S131).

[0133] Reference Figure 5i When the third wafer 230 and the supply substrate 300 are configured such that the plurality of third LEDs 150 on the third wafer 230 and the plurality of protrusions 331 on the supply substrate 300 face each other, the third wafer 230 and the supply substrate 300 can be aligned.

[0134] In this configuration, the first wafer 210 and the supply substrate 300 are aligned based on the first alignment key AK1 and the first alignment protrusion 333. However, the third wafer 230 and the supply substrate 300 may be aligned based on some of the second alignment keys AK2 among the plurality of second alignment marks AK2 transferred from the first wafer 210 to the supply substrate 300, which serve as a reference for alignment with the second wafer 220.

[0135] Specifically, when the supply substrate 300, on which a plurality of first LEDs 130, a plurality of second alignment keys AK2, and a plurality of second LEDs 140 are disposed, is aligned with the third wafer 230, the third wafer 230 and the supply substrate 300 can be aligned based on the second alignment key AK2 among the plurality of second alignment keys AK2 of the supply substrate 300 used for alignment with the second wafer 220. For example, the third wafer 230 and the supply substrate 300 can be aligned based on the second alignment key AK2 used for alignment with the second wafer 220, or on the first alignment key AK1 or the second alignment key AK2 of the third wafer 230. Furthermore, for example, the third wafer 230 and the supply substrate 300 can be aligned based on the second alignment key AK2 used for alignment with the second wafer 220 and some of the plurality of third LEDs 150 of the third wafer 230.

[0136] Reference Figure 5j After alignment between the third wafer 230 and the supply substrate 300 is completed, the third wafer 230 can be translated twice by a first gap IN1. After the second wafer 220 is translated by the first gap IN1, a plurality of second LEDs 140 are transferred to the supply substrate 300. Therefore, the third wafer 230 can be translated twice by the first gap IN1, i.e., by a second gap IN2, to suppress interference with the plurality of first LEDs 130 and the plurality of second LEDs 140 on the supply substrate 300. Finally, after the third wafer 230 is translated by the second gap IN2 in the same direction as the translation direction of the second wafer 220, a plurality of third LEDs 150 are transferred to the supply substrate 300.

[0137] Reference Figure 5l and Figure 5k The plurality of third LEDs 150 are transferred to the supply substrate 300 (S132). The plurality of third LEDs 150 can be transferred to the protrusions 331 of the plurality of protrusions 331 of the supply substrate 300 located at positions corresponding to the third sub-pixels. The plurality of third LEDs 150 can be LEDs (EDs) disposed in the third sub-pixels. Therefore, the plurality of third LEDs 150 can be transferred only to some of the protrusions 331 of the plurality of protrusions 331 disposed corresponding to the plurality of sub-pixels that are aligned with the third sub-pixels.

[0138] Multiple first LEDs 130, multiple second LEDs 140, and multiple third LEDs 150 can be disposed on the supply substrate 300 with a first interval IN1, which is the interval between multiple sub-pixels. For example, even if the multiple first LEDs 130 and multiple second alignment keys AK2 are set off from the center of the upper surfaces of the multiple protrusions 331 and multiple second alignment protrusions 334, the multiple second LEDs 140 and the multiple third LEDs 150 to be transferred are transferred based on the second alignment keys AK2 disposed at predetermined intervals from the multiple first LEDs 130. Therefore, the multiple second LEDs 140 and multiple third LEDs 150 can be set off from the multiple protrusions 331 in the same manner as the multiple first LEDs 130. Furthermore, the relative positions between the multiple first LEDs 130, multiple second LEDs 140, and multiple third LEDs 150 can be easily aligned. Therefore, the relative positions between the multiple first LEDs 130, multiple second LEDs 140, and multiple third LEDs 150 on the supply substrate 300 can correspond to multiple sub-pixels.

[0139] After the third LEDs 150 of the third wafer 230 are transferred to the supply substrate 300, the third wafer 230 and the supply substrate 300 are separated (S133) and the supply substrate 300 to which the third LEDs 150 have been transferred is discharged from the process equipment (S134).

[0140] Furthermore, this specification has already described the transfer of a plurality of second LEDs 140 and a plurality of third LEDs 150 after the second wafer 220 and the third wafer 230, which have been aligned with the supply substrate 300, have been translated by a predetermined interval. However, after the second wafer 220 and the third wafer 230 have been translated by a predetermined interval, the relative positions between the second wafer 220 and the third wafer 230 and the supply substrate 300 can be re-aligned, but is not limited to this. That is, the relative positions between the second wafer 220 and the third wafer 230 and the supply substrate 300, which have been translated by a predetermined interval, can be re-aligned. Therefore, the relative positions between the plurality of second LEDs 140 and the plurality of third LEDs 150 to be transferred to the supply substrate 300 and the plurality of first LEDs 130 on the supply substrate 300 can be more accurately aligned.

[0141] In the following text, reference will be made to Figure 6 and Figure 7 This describes a secondary transfer process in which multiple LEDs (EDs) from a supply substrate 300 are transferred to a display panel PN.

[0142] Figure 6 This is a process flow diagram illustrating a method for manufacturing a display device according to an exemplary embodiment of the present disclosure. Figure 7 This is a schematic process diagram illustrating a method for manufacturing a display device according to an exemplary embodiment of the present disclosure. Specifically, Figure 6 This is a flowchart illustrating the secondary transfer process of transferring multiple LEDs (EDs) from the supply substrate 300 to the display panel PN. Figure 7 It is a simplified process diagram used to illustrate the secondary transfer process.

[0143] Reference Figure 6 and Figure 7 A secondary transfer process (S200) is performed to transfer multiple LEDs (EDs) from the supply substrate 300 to the display panel PN. Thus, the manufacturing process of the display device 100 can be completed. In this case, circuitry (e.g., driving transistors 120 and multiple lines) for driving the multiple LEDs (EDs) has already been formed on the display panel PN.

[0144] A plurality of first LEDs 130, a plurality of second LEDs 140, and a plurality of third LEDs 150 on the supply substrate 300 are arranged in the same layout and at the same intervals as the plurality of sub-pixels. Since the plurality of first LEDs 130, a plurality of second LEDs 140, and a plurality of third LEDs 150 on the supply substrate 300 are arranged in the same layout and at the same intervals as the plurality of sub-pixels, the plurality of first LEDs 130, a plurality of second LEDs 140, and a plurality of third LEDs 150 on the supply substrate 300 can be transferred to the display panel PN in one go.

[0145] First, the supply substrate 300, which is provided with a plurality of first LEDs 130, a plurality of second LEDs 140, and a plurality of third LEDs 150, and the display panel PN are input into the process equipment (S210). Then, the supply substrate 300 and the display panel PN are aligned (S211).

[0146] In this case, the supply substrate 300 and the display panel PN can be aligned based on the second alignment key AK2 of the supply substrate 300 for alignment with the second wafer 220 and the third wafer 230 and the alignment key of the display panel PN.

[0147] The plurality of second LEDs 140 and the plurality of third LEDs 150 disposed on the supply substrate 300 are transferred not based on the first alignment protrusion 333 of the supply substrate 300, but based on the second alignment key AK2 transferred from the first wafer 210 to the supply substrate 300. That is, the spacing between the second alignment key AK2 and the plurality of first LEDs 130 is constant, and the spacing between the plurality of second LEDs 140 and the plurality of third LEDs 150 transferred to the supply substrate 300 based on the second alignment key AK2 and the second alignment key AK2 can also be constant. Therefore, only when the display panel PN and the supply substrate 300 are aligned based on the second alignment key AK2, the plurality of LEDs (EDs) can be easily transferred corresponding to the plurality of sub-pixels of the display panel PN.

[0148] If the supply substrate 300 and the display panel PN are aligned based on another component of the supply substrate 300, the plurality of second LEDs 140 and the plurality of third LEDs 150 can have various spacings with the other component. Therefore, the plurality of second LEDs 140 and the plurality of third LEDs 150 may not be transferred to their correct positions when transferred to the display panel PN. For example, when the supply substrate 300 and the display panel PN are aligned based on the first alignment protrusion 333 of the supply substrate 300, the centers of the upper surfaces of the plurality of protrusions 331 may be aligned corresponding to the plurality of sub-pixels. However, if the supply substrate 300 and the display panel PN are aligned based on the first alignment protrusion 333 when the plurality of first LEDs 130, the plurality of second LEDs 140 and the plurality of third LEDs 150 are disposed on the supply substrate 300 spaced apart from the centers of the upper surfaces of the plurality of protrusions 331, it may be difficult to transfer the plurality of LEDs (EDs) of the supply substrate 300 to their correct positions in the display panel PN.

[0149] Therefore, if the supply substrate 300 and the display panel PN are aligned based on the second alignment key AK2, which serves as a reference for aligning the relative positions of the plurality of first LEDs 130, the plurality of second LEDs 140, and the plurality of third LEDs 150 and has a constant interval with the plurality of LEDs (EDs), the alignment accuracy for transferring the plurality of LEDs (EDs) to the correct position can be improved. Thus, when transferring the plurality of first LEDs 130, the plurality of second LEDs 140, and the plurality of third LEDs 150 from the supply substrate 300 to the display panel PN, the supply substrate 300 and the display panel PN can be aligned based on the second alignment key AK2 for aligning with the second wafer 220 and the third wafer 230.

[0150] The alignment key for the display panel PN, which is to be aligned with the second alignment key AK2 on the supply substrate 300, can be any of the components formed on the display panel PN, or it can be formed and set separately. For example, if the alignment key is any of the components formed on the display panel PN, some of the reflective layers overlapping with the multiple LEDs (EDs) or some of the multiple lines used to drive the multiple LEDs (EDs) among the components formed on the display panel PN can be used as alignment keys. Furthermore, if the alignment key is formed and set separately, the alignment key can be a pattern or structure formed on the display panel PN, but is not limited to this.

[0151] Then, after the alignment between the supply substrate 300 and the display panel PN is completed, a plurality of first LEDs 130, a plurality of second LEDs 140, and a plurality of third LEDs 150 are transferred to the display panel PN (S212). Subsequently, after the plurality of LEDs (ED) of the supply substrate 300 are transferred to the display panel PN, the supply substrate 300 and the display panel PN are separated (S213) and discharged from the process equipment (S214).

[0152] Therefore, the manufacturing process of the display device 100 can be completed by a primary transfer process of transferring multiple LEDs (EDs) from the wafer 200 to the supply substrate 300 and a secondary transfer process of transferring the multiple LEDs (EDs) that have been transferred to the supply substrate 300 to the display panel PN.

[0153] Furthermore, in the manufacturing method of the display device 100 according to an exemplary embodiment of the present disclosure, a plurality of first LEDs 130, a plurality of second LEDs 140, and a plurality of third LEDs 150 may have a first interval IN1 when transferred to a supply substrate 300, so that the plurality of first LEDs 130, a plurality of second LEDs 140, and a plurality of third LEDs 150 are transferred to the display panel PN at one time. In this case, as described above, considering the alignment error between the wafer 200 and the supply substrate 300, the plurality of protrusions 331 may have a larger size than the plurality of LEDs (EDs). When the first wafer 210 and the supply substrate 300 are aligned, due to the alignment error between the first alignment key AK1 and the first alignment protrusions 333, the plurality of first LEDs 130 transferred to the plurality of protrusions 331 may be configured to be offset from the center of the upper surface of the plurality of protrusions 331. In this case, even if the second wafer 220 and the supply substrate 300 are realigned based on the first alignment key AK1 of the second wafer 220 and the first alignment protrusion 333 of the supply substrate 300, and the multiple second LEDs 140 transferred to the multiple protrusions 331 are set in their correct positions, the spacing between the multiple first LEDs 130 and the multiple second LEDs 140 may be different from the first spacing IN1, and the alignment accuracy may be reduced.

[0154] Therefore, when the second wafer 220 and the supply substrate 300 are aligned, they are aligned based on the second alignment key AK2, which is set at a predetermined interval with the first LED 130. Thus, multiple second LEDs 140 can be transferred while maintaining the relative positions between the multiple first LEDs 130 and the multiple second LEDs 140 transferred to the supply substrate 300 (i.e., the first interval IN1 between the multiple first LEDs 130 and the multiple second LEDs 140), and alignment accuracy can be improved.

[0155] In addition, Figures 4 to 7As illustrated, the supply substrate 300 is aligned with the second wafer 220 and the third wafer 230 and with the display panel PN based on a second alignment key AK2 transferred to the supply substrate 300 along with a plurality of first LEDs 130 in the outermost first sub-pixel among the plurality of sub-pixels. However, this disclosure is not limited thereto. A plurality of second LEDs 140 in the central second sub-pixel of the second wafer 220 and the second alignment key AK2 can be transferred to the supply substrate 300 first. Thereafter, the supply substrate 300 can be aligned with the first wafer 210 and the third wafer 230, and then aligned with the display panel PN based on the second alignment key AK2 from the second wafer 220. Alternatively, a plurality of third LEDs 150 in the third sub-pixel of the third wafer 230 and the second alignment key AK2 can be transferred to the supply substrate 300 first. Subsequently, the supply substrate 300 can be aligned with the first wafer 210 and the second wafer 220, and then aligned with the display panel PN based on the second alignment key AK2 from the third wafer 230. Therefore, according to this disclosure, the order of the first wafer 210, the second wafer 220 and the third wafer 230 in a single transfer process is not limited to this, as long as the remaining wafers 200 and the supply substrate 300 are aligned based on the plurality of LEDs (EDs) first transferred to the supply substrate 300 and the second alignment key AK2.

[0156] In the following text, reference will be made to Figures 8 to 11 The effects of improving the alignment accuracy of a plurality of LEDs (EDs) in a method of manufacturing a display device 100 according to an exemplary embodiment of the present disclosure will be described in more detail.

[0157] Figure 8 and Figure 9 This is a diagram used to illustrate the alignment error range in the manufacturing method of the display device according to the comparative embodiment. Figure 10 and Figure 11 This is a diagram illustrating the alignment error range in a manufacturing method of a display device according to an exemplary embodiment. Specifically, Figures 8 to 11 This is a diagram illustrating the ideal correct position of multiple LEDs during the first and second transfer processes and the discreteness caused by alignment errors. Figure 8 This is a diagram used to illustrate the alignment error range in the manufacturing method of the display device according to Comparative Embodiment 1, and Figure 9 This is a diagram illustrating the alignment error range in the manufacturing method of the display device according to Comparative Embodiment 2. Figure 10 This is a diagram illustrating the alignment error range in a manufacturing method of a display device according to Exemplary Embodiment 1. Figure 11 This is a diagram illustrating the alignment error range in a manufacturing method of a display device according to Exemplary Embodiment 2.

[0158] also, Figures 8 to 11 The alignment error ranges X, 2X, and 3X shown can be defined as the diameters of the largest areas that can be transferred while the multiple LEDs and the second alignment key deviate from their correct positions due to alignment errors. The alignment error range X corresponding to what is essentially possible in the secondary transfer process is illustrated below. Figures 8 to 11 The diameter of the circle shown, centered at the correct locations B, B′, and B″.

[0159] The method of Embodiment 1 differs from the manufacturing method of the display device 100 according to an exemplary embodiment of the present disclosure in that, during a first transfer step, a first alignment key of a first wafer is aligned with a first alignment protrusion of a supply substrate to transfer a plurality of first LEDs 30, a first alignment key of a second wafer is aligned with a first alignment protrusion of a supply substrate to transfer a plurality of second LEDs 40, and a first alignment key of a third wafer is aligned with a first alignment protrusion of a supply substrate to transfer a plurality of third LEDs 50. The method of Embodiment 2 is substantially the same as the manufacturing method of the display device 100 according to an exemplary embodiment of the present disclosure, except that, during a second transfer step, the supply substrate and the display panel are aligned based on a second alignment key transferred together with the second LEDs 40'. The method of Embodiment 1 is substantially the same as the manufacturing method of the display device 100 according to an exemplary embodiment of the present disclosure in that, the first and second transfer steps are performed based on the first LED 130 of the outermost sub-pixel (e.g., the first sub-pixel) among the plurality of LEDs. In Exemplary Embodiment 2, compared to the manufacturing method of the display device 100 according to an exemplary embodiment of the present disclosure, a first transfer step and a second transfer step are performed based on a second LED 140', which is a central sub-pixel (e.g., a second sub-pixel) among a plurality of LEDs, and a second alignment key transferred together with the second LED 140'. In the following, for ease of description, it is assumed that the alignment error range between the supply substrate and the wafer is X during the first transfer step, and the alignment error range between the supply substrate and the display panel is also X during the second transfer step.

[0160] Reference Figure 8 It can be assumed that during a single transfer process of transferring multiple LEDs from a wafer to a supply substrate, the ideal correct positions of the multiple LEDs transferred to the supply substrate are points A, A′, and A″, respectively. Specifically, point A is the correct position of the first LED 30 on the supply substrate, point A′ is the correct position of the second LED 40 on the supply substrate, and point A″ is the correct position of the third LED 50 on the supply substrate.

[0161] In the manufacturing method of the display device according to Comparative Embodiment 1, a first transfer process is performed by aligning the first alignment key of each of a plurality of wafers with the first alignment protrusion of the supply substrate, and a second transfer process is performed by aligning the display panel and the supply substrate based on the second alignment key transferred from the first wafer among a plurality of second alignment keys on the supply substrate.

[0162] In the manufacturing method of the display device according to Comparative Embodiment 1, a plurality of first LEDs 30 and a second alignment key of a first wafer can be transferred to a supply substrate during a single transfer process. In this case, the first wafer and the supply substrate can be aligned based on the first alignment key of the first wafer and the first alignment protrusion of the supply substrate, and dispersion may occur due to alignment errors. For example, when the plurality of first LEDs 30 and the second alignment key are transferred from the first wafer to the supply substrate, dispersion centered on the correct position point A may occur within the alignment error range X.

[0163] Specifically, the resin layer, multiple protrusions, and multiple alignment protrusions of the supply substrate may comprise a viscoelastic material, and pressure may be applied to the supply substrate when it is bonded to the wafer, which may cause deformation of the resin layer, multiple protrusions, and multiple alignment protrusions. Therefore, even if multiple LEDs and second alignment bonds are transferred to their correct positions, the supply substrate may be locally deformed, and each of the transferred LEDs and second alignment bonds may deviate from their correct positions. Furthermore, alignment errors between the wafer and the supply substrate may also be caused by process errors, and therefore, dispersion of the multiple LEDs and second alignment bonds may occur. In this case, the maximum range of deviation from the correct position that may occur can be the alignment error range X. That is, the second alignment bonds and multiple LEDs may be dispersed within the dispersion. For example, the second alignment bond may deviate most from its correct position within the alignment error range X and may be positioned on the outermost side within the dispersion, and the other multiple LEDs may be positioned within the dispersion in various ways. In other words, due to process errors, each of the multiple first LEDs 30 and multiple second alignment bonds may be dispersed within the alignment error range X and within the dispersion.

[0164] After a single transfer of the plurality of first LEDs 30 and the second alignment key, the plurality of second LEDs 40 and the second alignment key of the second wafer can be transferred to the supply substrate. In this case, the second wafer and the supply substrate can be aligned based on the first alignment key of the second wafer and the first alignment protrusion of the supply substrate. Furthermore, when the plurality of second LEDs 40 and the second alignment key are transferred from the second wafer to the supply substrate, a discrete portion centered at the correct position point A′ may appear within the alignment error range X.

[0165] Finally, the plurality of third LEDs 50 and the second alignment key of the third wafer can be transferred to the supply substrate. In this case, the third wafer and the supply substrate can be aligned based on the first alignment key of the third wafer and the first alignment protrusion of the supply substrate. Furthermore, when the plurality of third LEDs 50 and the second alignment key are transferred from the third wafer to the supply substrate, a discrete portion centered on the correct position point A″ may appear within the alignment error range X.

[0166] It can be assumed that during the secondary transfer process of transferring multiple LEDs from the supply substrate to the display panel, the ideal correct positions of the multiple LEDs transferred to the display panel are points B, B′, and B″, respectively. Specifically, point B is the correct position of the first LED 30 and the second alignment key on the display panel, point B′ is the correct position of the second LED 40 and the second alignment key on the display panel, and point B″ is the correct position of the third LED 50 and the second alignment key on the display panel. The correct position points B′ of the multiple second LEDs 40 and B″ of the multiple third LEDs 50 are ideal correct positions with a first interval IN1, where the first interval IN1 is the interval between the multiple first LEDs 30, the multiple second LEDs 40, and the multiple third LEDs 50 and the multiple sub-pixels.

[0167] Then, the multiple LEDs and the second alignment key of the supply substrate can be transferred to the display panel. During the secondary transfer process, the multiple first LEDs 30, the multiple second LEDs 40, and the multiple third LEDs 50 can be transferred to be located at the correct position points B, B′, and B″ on the display panel.

[0168] During the secondary transfer process, the supply substrate and the display panel can be aligned based on the second alignment key to transfer a plurality of first LEDs 30, a plurality of second LEDs 40, and a plurality of third LEDs 50 from the supply substrate to the display panel. In this case, the discrete positions of the plurality of first LEDs 30 and the second alignment key can vary depending on the position of the second alignment key within a discrete portion according to the alignment error range X. For example, when the second alignment key, which is centered within the discrete portion, is set at the correct position point B, the plurality of first LEDs 30 and the second alignment key can exhibit the same discrete portion centered at the correct position point B as in the primary transfer process.

[0169] However, the second alignment key may deviate from the correct position point B due to alignment errors. For example, the second alignment key may be located on the rightmost side of the discrete portion of the plurality of first LEDs 30 and the second alignment key, and the plurality of first LEDs 30 may be distributed between the leftmost and rightmost sides of this discrete portion. In this case, during the secondary transfer process based on the second alignment key on the rightmost side of the discrete portion, due to process errors, the second alignment key may be biased towards point ① to the left of the correct position point B. Therefore, the final discreteness of the plurality of first LEDs 30 and the second alignment key may be shifted to the outside of point ①. In other words, when the second alignment key is located on the rightmost side of the discrete portion of the plurality of first LEDs 30 and the second alignment key, and during the secondary transfer process based on the second alignment key, the second alignment key is biased towards point ① to the left of the correct position point B, the discreteness of the plurality of first LEDs 30 and the second alignment key may be shifted to the outside of point ①. As another example, the second alignment key may be located on the leftmost side of the discrete portion of the plurality of first LEDs 30 and the second alignment key, and the plurality of first LEDs 30 may be distributed between the rightmost and leftmost sides of the discrete portion. In this case, during the secondary transfer process based on the second alignment key on the leftmost side of the discrete part, due to process errors, the second alignment key may be biased towards point ② to the right of the correct position point B. Therefore, the final discreteness of the multiple first LEDs 30 and the second alignment key can be translated to the outside of point ②.

[0170] Furthermore, during the secondary transfer process, the display panel and the supply substrate are aligned based on the second alignment bond transferred from the first wafer. Therefore, the plurality of second LEDs 40 and the plurality of third LEDs 50 disposed on the supply substrate can exhibit the same discreteness as the plurality of first LEDs 30 and the second alignment bond. Specifically, the plurality of second LEDs 40 and the plurality of third LEDs 50 disposed on the supply substrate are transferred to the display panel based on the second alignment bond from the first wafer. That is, the plurality of second LEDs 40 and the plurality of third LEDs 50 disposed on the supply substrate can be transferred to the display panel while maintaining their relative positions with respect to the plurality of first LEDs 30 and the second alignment bond. Therefore, when the second alignment bond from the first wafer deviates from the correct position point B, the dispersion of the plurality of second LEDs 40 and the plurality of third LEDs 50 can also be translated in the same manner as the second alignment bond, and thus can deviate from their correct position points B′ and B″ respectively. Therefore, the basic alignment error range between the display panel and the supply substrate is X, but by adding the alignment error during the first transfer process, the alignment error range of each of the plurality of first LEDs 30, the plurality of second LEDs 40 and the plurality of third LEDs 50 during the second transfer process can reach 3X.

[0171] Subsequently, refer to Figure 9In the manufacturing method of the display device according to Comparative Embodiment 2, a plurality of first LEDs 30', a plurality of second LEDs 40', and a plurality of third LEDs 50' are transferred to a supply substrate, and the plurality of first LEDs 30', a plurality of second LEDs 40', and a plurality of third LEDs 50' on the supply substrate are transferred to a display panel in one step. In this case, during the first transfer step, the plurality of second LEDs 40' on the second wafer and the third LEDs 50' on the third wafer are transferred to the supply substrate based on a second alignment key transferred together with the plurality of first LEDs 30', and in the second transfer step, the plurality of LEDs on the supply substrate are transferred to the display panel based on the second alignment key transferred together with the plurality of second LEDs 40'. That is, during the first transfer step, the second alignment key transferred together with the first LEDs 30' can be used as a reference for alignment, and during the second transfer step, the second alignment key transferred together with the second LEDs 40' can be used as a reference for alignment.

[0172] A plurality of first LEDs 30' and a second alignment key of the first wafer are transferred to a supply substrate. Then, after aligning the second and third wafers with the supply substrate based on the second alignment key disposed on the supply substrate, a plurality of second LEDs 40' and a plurality of third LEDs 50' are transferred to the supply substrate. In this case, the second alignment key, which itself is disposed at a predetermined interval with the plurality of first LEDs 30', serves as a reference for alignment between the second and third wafers and the supply substrate; therefore, the alignment error range and dispersion of the plurality of first LEDs 30' can be ignored. Specifically, even if the plurality of first LEDs 30' deviate from the correct position point A on the upper surface of the plurality of protrusions of the supply substrate due to alignment errors between the first wafer and the supply substrate, the plurality of second LEDs 40' and the plurality of third LEDs 50' to be transferred are transferred by aligning their relative positions with respect to the second alignment key and the plurality of first LEDs 30'. Therefore, the plurality of second LEDs 40' and the plurality of third LEDs 50' can also be offset from the correct position points A' and A″ on the upper surface of the plurality of protrusions of the supply substrate in the same manner as the first LED 30'. Furthermore, each of the plurality of first LEDs 30', the plurality of second LEDs 40', and the plurality of third LEDs 50' can be arranged on the supply substrate at a first interval. Therefore, the plurality of first LEDs 30' and the second alignment key arranged at predetermined intervals with the plurality of first LEDs 30' serve as a reference for alignment between the second and third wafers and the supply substrate, thus eliminating the alignment error range and dispersion of the plurality of first LEDs 30'.

[0173] Furthermore, the plurality of first LEDs 30′ disposed on the supply substrate and the plurality of second LEDs 40′ transferred to the supply substrate by the second alignment key can exhibit discreteness centered on the correct position point A′ within the alignment error range X. Similarly, the plurality of third LEDs 50′ disposed on the supply substrate and the plurality of first LEDs 30′ transferred to the supply substrate by the second alignment key can exhibit discreteness centered on the correct position point A″ within the alignment error range X.

[0174] Then, during the secondary transfer process of transferring multiple LEDs from the supply substrate to the display panel, the supply substrate and the display panel can be aligned based on multiple second LEDs 40′ and a second alignment key transferred together with the multiple second LEDs 40′. Then, the multiple LEDs from the supply substrate can be transferred to the display panel. During the secondary transfer process, the multiple LEDs can be transferred to the correct position points B, B′, and B″ on the display panel.

[0175] When transferring multiple LEDs from the supply substrate by aligning the supply substrate and the display panel based on multiple second LEDs 40' and a second alignment key from the second wafer, the positions of the multiple second LEDs 40' and the second alignment key can be changed based on the correct position point B' according to the alignment error. For example, if the second alignment key is located at the rightmost position within the discrete portion of the multiple second LEDs 40' and the second alignment key, and the second alignment key is shifted to be biased towards point ① to the left of the correct position point B', then the discrete portion of the multiple second LEDs 40' and the second alignment key can be translated to the outside of point ①. For example, if the second alignment key is located at the leftmost position within the discrete portion of the multiple second LEDs 40' and the second alignment key, and the second alignment key is shifted to be biased towards point ② to the right of the correct position point B', then the discrete portion of the multiple second LEDs 40' and the second alignment key can be translated to the outside of point ②. Therefore, the alignment error range of the multiple second LEDs 40' during the secondary transfer process can be as high as 3X.

[0176] Furthermore, the plurality of first LEDs 30' and the plurality of third LEDs 50' transferred to the display panel based on the second LED 40' from the second wafer and the second alignment key transferred together with the second LED 40' can be transferred onto the display panel while maintaining their relative positions to the plurality of second LEDs 40'. If the plurality of second LEDs 40' are biased to one side of the correct position point B' due to alignment errors during transfer, the plurality of first LEDs 30' and the plurality of third LEDs 50' can also be biased to one side of the correct position points B and B″, respectively, during transfer. For example, if the plurality of second LEDs 40' and the second alignment key are biased to point ① to the left of the correct position point B' during transfer, the plurality of first LEDs 30' and the plurality of third LEDs 50' can also be biased to point ① to the left of the correct position points B and B', respectively, during transfer. Therefore, during the secondary transfer process, since the alignment error range of the plurality of second LEDs 40' is 3X, the plurality of third LEDs 50' can have an alignment error range of 3X relative to the correct position point B″ of the display panel. However, for multiple first LEDs 30', during the first transfer process, the multiple first LEDs 30' and the second alignment key AK2 transferred together with the multiple first LEDs 30' serve as a reference for alignment, and the discreteness of the multiple first LEDs 30' is eliminated. Therefore, during the second transfer process, the multiple first LEDs 30' can have an alignment error range of only 2X.

[0177] Reference Figure 10 The manufacturing method of the display device according to Exemplary Embodiment 1 is substantially the same as the manufacturing method of the display device 100 according to the Exemplary Embodiment of this Disclosure. First, a plurality of first LEDs 130 of the first wafer 210 can be transferred to the supply substrate 300. Specifically, the first wafer 210 and the supply substrate 300 can be aligned based on the alignment keys of the first wafer 210 and the alignment protrusions 332 of the supply substrate 300 to transfer the plurality of first LEDs 130 onto the plurality of protrusions 331 of the supply substrate 300.

[0178] Then, a plurality of second LEDs 140 and a plurality of third LEDs 150 can be aligned based on a second alignment key AK2 transferred from the first wafer 210 to the supply substrate 300 together with a plurality of first LEDs 130.

[0179] In this configuration, the plurality of second LEDs 140 of the second wafer 220 and the plurality of third LEDs 150 of the third wafer 230 are transferred to the supply substrate 300 based on the second alignment key AK2, which is transferred together with the plurality of first LEDs 130. Therefore, the alignment error range and dispersion of the first LEDs 130 transferred to the supply substrate 300 can be ignored. Since the plurality of first LEDs 130 themselves serve as a reference for alignment between the second wafer 220 and the third wafer 230 and the supply substrate 300, the relative position between the plurality of first LEDs 130 and the protrusions 331 of the supply substrate 300 is not important; it is sufficient that the plurality of first LEDs 130 are transferred to the upper surface of the protrusions 331 of the supply substrate 300. For example, if the plurality of first LEDs 130 are configured to be biased towards one side of the protrusions 331 of the supply substrate 300, then the second LEDs 140 of the second wafer 220 and the third LEDs 150 of the third wafer 230 are aligned and transferred based on the first LEDs 130. Therefore, the second LED 140 and the third LED 150 can also be shifted to one side of the protrusion 331 of the supply substrate 300. Thus, the plurality of first LEDs 130, the plurality of second LEDs 140 and the plurality of third LEDs 150 shifted onto the supply substrate 300 can be arranged at an interval equal to or close to the first interval IN1.

[0180] After the second wafer 220 and the third wafer 230 are aligned based on the second alignment key AK2 transferred to the supply substrate 300 together with the first LED 130, a plurality of second LEDs 140 and a plurality of third LEDs 150 of the second wafer 220 can be transferred to the supply substrate 300. In this case, when the second wafer 220 is aligned based on the second alignment key AK2 transferred together with the first LED 130, dispersion may occur due to alignment errors. For example, the plurality of second LEDs 140 may have an alignment error range X when transferred from the second wafer 220 to the supply substrate 300, and therefore, dispersion centered on the correct position point A′ may occur. The plurality of third LEDs 150 may have an alignment error range X when transferred from the third wafer 230 to the supply substrate 300, and therefore, dispersion centered on the correct position point A″ may occur.

[0181] After the supply substrate 300 and the display panel PN are aligned based on the second alignment key AK2 transferred to the supply substrate 300 together with the first LED 130, a plurality of LEDs (EDs) on the supply substrate 300 can be transferred to the display panel PN. During the secondary transfer process, the plurality of LEDs (EDs) can be transferred to the correct position points B, B′ and B″ on the display panel PN.

[0182] In this configuration, when multiple first LEDs 130 are transferred to the correct position point B on the display panel PN, multiple second LEDs 140 and multiple third LEDs 150 can also be positioned at the correct position points B′ and B″. Since the multiple second LEDs 140 and multiple third LEDs 150 on the supply substrate 300 are transferred to the display panel PN simultaneously with the multiple first LEDs 130, the relative positions of the multiple second LEDs 140 and multiple third LEDs 150 relative to the multiple first LEDs 130 can be fixed. Furthermore, the multiple second LEDs 140 can be transferred to the correct position point B′ on the display panel PN based on the discreteness that occurs in a single transfer process. That is, the multiple second LEDs 140 can exhibit the same discreteness centered on the correct position point B′ as in a single transfer process. Similarly, the multiple third LEDs 150 positioned on the display panel PN can exhibit the same discreteness centered on the correct position point B″ as in a single transfer process.

[0183] Furthermore, during the secondary transfer process, the first LED 130 may have an alignment error range X, and due to the alignment error, the first LED 130 may be set to be biased towards one side of the correct position point B on the display panel PN. For example, if the first LED 130 is biased towards point ① to the left of the correct position point B during transfer, then the multiple second LEDs 140 disposed on the supply substrate 300 based on the second alignment key AK2 transferred together with the multiple first LEDs 130 may also be biased towards point ① to the left of the correct position point B′ and transferred to the display panel PN. The multiple second LEDs 140 may also exhibit dispersion centered on point ①. Furthermore, the multiple third LEDs 150 disposed on the supply substrate 300 based on the second alignment key AK2 transferred together with the multiple first LEDs 130 may also be biased towards point ① to the left of the correct position point B″ and transferred to the display panel PN. The multiple third LEDs 150 may also exhibit dispersion centered on point ①.

[0184] Similarly, if the first LED 130 is biased towards point ② due to alignment error during transfer, then the plurality of second LEDs 140 disposed on the supply substrate 300 based on the second alignment key AK2 transferred together with the plurality of first LEDs 130 can also be biased towards point ② to the right of the correct position point B′ and transferred to the display panel PN. The plurality of second LEDs 140 can also exhibit dispersion centered on point ②. Furthermore, the plurality of third LEDs 150 disposed on the supply substrate 300 based on the second alignment key AK2 transferred together with the plurality of first LEDs 130 can also be biased towards point ② to the right of the correct position point B″ and transferred to the display panel PN. The plurality of third LEDs 150 can also exhibit dispersion centered on point ②.

[0185] Therefore, the plurality of first LEDs 130 can have an alignment error range X and a final discreteness during the secondary transfer process. Furthermore, due to the alignment error range X during the primary transfer process and the alignment error range X of the plurality of first LEDs 130, the plurality of second LEDs 140 and the plurality of third LEDs 150 can have an alignment error range of 2X relative to the correct position points B′ and B″ on the display panel PN. However, even if the plurality of second LEDs 140 and the plurality of third LEDs 150 have an alignment error range of 2X, the relative positions of the plurality of first LEDs 130 with respect to the plurality of second LEDs 140 and the plurality of third LEDs 150, i.e., the spacing between the plurality of LEDs (ED), can be equal to or close to the first spacing IN1.

[0186] Finally, refer to Figure 11 In the manufacturing method of the display device according to Exemplary Embodiment 2, a plurality of second LEDs 140' and a second alignment key AK2 of a second wafer are first transferred to a supply substrate. Subsequently, a plurality of first LEDs 130' of a first wafer and a plurality of third LEDs 150' of a third wafer can be transferred onto the supply substrate. In this case, the first wafer and the supply substrate can be aligned based on the second alignment key transferred from the second wafer to the supply substrate, and the third wafer and the supply substrate can also be aligned based on the second alignment key transferred from the second wafer to the supply substrate.

[0187] Then, after the first wafer aligned with the supply substrate is translated by a first interval, the plurality of first LEDs 130' can be transferred to one side of the plurality of second LEDs 140' respectively. After the third wafer is translated by a first interval in the opposite direction to the translation direction of the first wafer, the plurality of third LEDs 150' can be transferred to the other side of the plurality of second LEDs 140' respectively.

[0188] In this configuration, a plurality of first LEDs 130' of the first wafer and a plurality of third LEDs 150' of the third wafer are transferred to the supply substrate based on a second alignment key that is transferred together with a plurality of second LEDs 140'. Therefore, the alignment error range and dispersion of the plurality of second LEDs 140' transferred to the supply substrate can be eliminated. Specifically, the second alignment key, which is itself arranged at predetermined intervals with the plurality of second LEDs 140', serves as a reference for alignment between the first and third wafers and the supply substrate. Therefore, the alignment error range and dispersion of the plurality of second LEDs 140' can be ignored. Specifically, even if the plurality of second LEDs 140' deviate from the correct position point A' on the upper surface of a plurality of protrusions of the supply substrate due to alignment errors between the second wafer and the supply substrate, the plurality of first LEDs 130' and the plurality of third LEDs 150' to be transferred are transferred by aligning their relative positions with respect to the second alignment key and the plurality of second LEDs 140'. Therefore, the plurality of first LEDs 130' and the plurality of third LEDs 150' can also be offset from the correct position points A and A″ on the upper surface of the plurality of protrusions of the supply substrate in the same manner as the plurality of second LEDs 140'. Furthermore, the plurality of first LEDs 130', the plurality of second LEDs 140', and the plurality of third LEDs 150' can each be arranged on the supply substrate at a first interval. Therefore, the plurality of second LEDs 140' and the second alignment key arranged at a predetermined interval with the plurality of second LEDs 140' serve as a reference for alignment between the first and third wafers and the supply substrate, thus eliminating the alignment error range and dispersion of the plurality of second LEDs 140'.

[0189] After the first wafer and the third wafer are aligned based on the second alignment key transferred to the supply substrate together with the plurality of second LEDs 140', the plurality of first LEDs 130' and the plurality of third LEDs 150' can be transferred to the supply substrate. In this case, when the first wafer is aligned based on the second alignment key transferred together with the plurality of second LEDs 140', dispersion can occur due to alignment errors. For example, the plurality of first LEDs 130' may have an alignment error range X when transferred from the first wafer to the supply substrate, and thus dispersion centered on the correct position point A may occur. The plurality of third LEDs 150' may have an alignment error range X when transferred from the third wafer to the supply substrate, and thus dispersion centered on the correct position point A″ may occur.

[0190] After the supply substrate and display panel are aligned based on the second alignment key transferred to the supply substrate together with the second LED 140′, multiple LEDs on the supply substrate can be transferred to the display panel. During the secondary transfer process, multiple LEDs can be transferred to the correct position points B, B′, and B″ on the display panel.

[0191] In this configuration, when multiple second LEDs 140' and the second alignment key are transferred to the correct position point B' on the display panel, multiple first LEDs 130' and multiple third LEDs 150' can also be positioned at the correct position points B and B″. Since the multiple first LEDs 130' and multiple third LEDs 150' on the supply substrate are transferred to the display panel simultaneously with the multiple second LEDs 140', the relative positions of the multiple first LEDs 130' and multiple third LEDs 150' relative to the multiple second LEDs 140' can be fixed. Furthermore, the multiple first LEDs 130' can be transferred to the correct position point B on the display panel based on the dispersion that occurs in a single transfer process. That is, the multiple first LEDs 130' can exhibit the same dispersion centered on the correct position point B as in a single transfer process. Similarly, the multiple third LEDs 150' positioned on the display panel can exhibit the same dispersion centered on the correct position point B″ as in a single transfer process.

[0192] Furthermore, during the secondary transfer process, the second LED 140' may have an alignment error range X, and the second LED 140' may be configured to be biased towards one side of the correct position point B' on the display panel due to alignment errors. For example, if the second LED 140' is biased towards point ① to the left of the correct position point B' during transfer, then the plurality of first LEDs 130' disposed on the supply substrate based on the second alignment key transferred together with the plurality of second LEDs 140' may also be biased towards point ① to the left of the correct position point B' and transferred to the display panel. The plurality of first LEDs 130' may also exhibit dispersion centered on point ①. Furthermore, the plurality of third LEDs 150' disposed on the supply substrate based on the second alignment key transferred together with the plurality of second LEDs 140' may also be biased towards point ① to the left of the correct position point B″ and transferred to the display panel. The plurality of third LEDs 150' may also exhibit dispersion centered on point ①.

[0193] Similarly, if the second LED 140' is biased towards point ② to the right of the correct position point B' due to alignment errors during transfer, then the plurality of first LEDs 130' disposed on the supply substrate based on the second alignment key transferred together with the plurality of second LEDs 140' can also be biased towards point ② to the right of the correct position point B and transferred to the display panel. The plurality of first LEDs 130' can also exhibit dispersion centered on point ②. Furthermore, the plurality of third LEDs 150' disposed on the supply substrate based on the second alignment key transferred together with the plurality of second LEDs 140' can also be biased towards point ② to the right of the correct position point B″ and transferred to the display panel. The plurality of third LEDs 150' can also exhibit dispersion centered on point ②.

[0194] Therefore, the plurality of second LEDs 140' can have an alignment error range X during the secondary transfer process and a final discreteness. Furthermore, due to the alignment error range X during the primary transfer and the alignment error range X of the plurality of second LEDs 140', the plurality of first LEDs 130' and the plurality of third LEDs 150' can have an alignment error range of 2X relative to the correct position points B and B″ on the display panel. However, even if the plurality of first LEDs 130' and the plurality of third LEDs 150' have an alignment error range of 2X, the relative positions of the plurality of first LEDs 130' relative to the plurality of second LEDs 140' and the plurality of third LEDs 150', i.e., the spacing between the plurality of LEDs, can be equal to or close to the first spacing.

[0195] In summary, in the manufacturing method of the display device according to Comparative Embodiment 1, the first alignment key of each of the plurality of wafers and the first alignment protrusion of the supply substrate can be aligned, so that a plurality of LEDs are transferred to the supply substrate, and the display panel and the supply substrate can be aligned based on one of the second alignment keys transferred to the supply substrate, so that a plurality of first LEDs 30, a plurality of second LEDs 40 and a plurality of third LEDs 50 can be transferred to the display panel. Therefore, due to the alignment error between the wafer and the supply substrate during the first transfer process and the alignment error between the supply substrate and the display panel during the second transfer process, the alignment error range of the plurality of first LEDs 30, the plurality of second LEDs 40 and the plurality of third LEDs 50 can be as high as 3X. Therefore, since the first alignment key of each of the plurality of wafers is aligned with the first alignment key of the supply substrate, the spacing between the plurality of first LEDs 30, the plurality of second LEDs 40 and the plurality of third LEDs 50 on the supply substrate can be different from the first spacing. Furthermore, even when the plurality of first LEDs 30, the plurality of second LEDs 40 and the plurality of third LEDs 50 are transferred to the display panel, the second alignment key from the first wafer, which serves as a reference, exhibits dispersion. If the display panel and the supply substrate are aligned based on a second alignment key that exhibits discreteness, then the second alignment key and each of the multiple LEDs are unlikely to be moved to their correct positions due to process errors. Therefore, it is difficult to accurately align the multiple first LEDs 30, the multiple second LEDs 40, and the multiple third LEDs 50.

[0196] In the manufacturing method of the display device according to Comparative Embodiment 2, during a primary transfer step of the plurality of first LEDs 30', the plurality of second LEDs 40', and the plurality of third LEDs 50', the relative positions of the plurality of first LEDs 30' with respect to the plurality of second LEDs 40' and the plurality of third LEDs 50' are aligned based on a second alignment key that is transferred together with the plurality of first LEDs 30'. Therefore, during the primary transfer step, the dispersion of the plurality of first LEDs 30' caused by alignment errors can be reduced compared to Comparative Embodiment 1. However, since the supply substrate and the display panel are aligned during a secondary transfer step based on the plurality of second LEDs 40' exhibiting dispersion and the second alignment key that is transferred together with the plurality of second LEDs 40', the plurality of second LEDs 40' and the plurality of third LEDs 50' exhibiting dispersion during the primary transfer step can have an alignment error range of up to 3X, and the plurality of first LEDs 30', which have been eliminated during the primary transfer step, can also have an alignment error range of up to 2X. Therefore, in Comparative Implementation 2, where the reference used for alignment during the first transfer process differs from the reference used for alignment during the second transfer process, the alignment error range of the multiple LEDs is 2X to 3X. Consequently, it is difficult to transfer each of the multiple LEDs to its correct position, and the alignment accuracy can be reduced.

[0197] In the manufacturing method of the display device according to Exemplary Embodiment 1, during a first transfer step, the relative positions of a plurality of first LEDs 130 with respect to a plurality of second LEDs 140 and a plurality of third LEDs 150 are aligned using a second alignment key AK2 transferred together with the plurality of first LEDs 130 as a reference member, thus eliminating the alignment error range and dispersion of the plurality of first LEDs 130 during the first transfer step. Then, even in the second transfer step, the supply substrate 300 and the display panel PN are aligned based on the same second alignment key AK2 as in the first transfer step. Therefore, the plurality of first LEDs 130 may have an alignment error range of only X, and the plurality of second LEDs 140 and the plurality of third LEDs 150 transferred based on the plurality of first LEDs 130 may also have an alignment error range of up to 2X. Therefore, in Exemplary Embodiment 1, where the reference used for alignment during the first transfer step is the same as the reference used for alignment during the second transfer step, the alignment error range of the plurality of LEDs is from X to 2X. Therefore, each of the plurality of LEDs is more likely to be transferred to its correct position than in Comparative Embodiments 1 and 2. Even taking alignment errors into account, the spacing between multiple LEDs (EDs) can be close to the first spacing IN1. Therefore, alignment accuracy can be improved.

[0198] The manufacturing method of the display device according to Exemplary Embodiment 2 differs from the method of Exemplary Embodiment 1 only in that a plurality of second LEDs 140' transferred to a second sub-pixel as a central sub-pixel and a second alignment key transferred together with the plurality of second LEDs 140' are used as alignment references. In the manufacturing method of the display device according to Exemplary Embodiment 2, during a first transfer step, a plurality of second LEDs 140' and a second alignment key from a second wafer are first transferred to a supply substrate, and the relative positions of the plurality of second LEDs 140' with respect to a plurality of first LEDs 130' and a plurality of third LEDs 150' are aligned based on the second alignment key from the second wafer. Since the second alignment key, which maintains a predetermined interval with the plurality of second LEDs 140', is used as a reference member in the first transfer step, the alignment error range and dispersion of the plurality of second LEDs 140' can be eliminated. Then, even in a second transfer step, the supply substrate and the display panel are aligned based on the same second alignment key as in the first transfer step. Therefore, the plurality of second LEDs 140' can have an alignment error range of only X, and the plurality of first LEDs 130' and the plurality of third LEDs 150' transferred based on the plurality of second LEDs 140' can also have an alignment error range of up to 2X. Thus, in exemplary embodiment 2, where the reference used for alignment during a first transfer step is the same as the reference used for alignment during a second transfer step, the alignment error range of the plurality of LEDs is from X to 2X. Therefore, each of the plurality of LEDs is more likely to be transferred to its correct position than in comparative embodiments 1 and 2. Even considering alignment errors, the spacing between the plurality of LEDs can be close to the first spacing. Therefore, alignment accuracy can be improved.

[0199] Therefore, in the display device 100 according to an exemplary embodiment of the present disclosure, the relative positions of other LEDs (EDs) to be transferred to the supply substrate 300 are aligned based on the second alignment key AK2, which is transferred together with a plurality of LEDs (EDs) during a single transfer process and maintains the same interval with the plurality of LEDs (EDs). Therefore, the alignment error range of the plurality of LEDs (EDs) can be reduced and the alignment accuracy can be improved. Specifically, for the first wafer 210 initially aligned with the supply substrate 300, the supply substrate 300 and the first wafer 210 are aligned based on the first alignment key AK1 of the first wafer 210 and the first alignment protrusion 333 of the supply substrate 300, such that a plurality of first LEDs 130 and a plurality of second alignment keys AK2 are transferred to the upper surfaces of a plurality of protrusions 331 and a plurality of second alignment protrusions 334, respectively. After the plurality of first LEDs 130 and a plurality of second alignment keys AK2 are transferred together to the supply substrate 300, the second wafer 220 and the third wafer 230 can be aligned with the supply substrate 300 based on the plurality of second alignment keys AK2. Even in the secondary transfer process, the supply substrate 300 and the display panel PN can be aligned based on the same second alignment key AK2. The second alignment key AK2, transferred to the supply substrate 300 along with the plurality of first LEDs 130, can maintain the same spacing with each of the plurality of first LEDs 130. Therefore, when the second wafer 220 and the third wafer 230 are aligned with the supply substrate 300 based on the second alignment key AK2, their relative positions can be aligned so that the plurality of second LEDs 140 of the second wafer 220 and the plurality of first LEDs 130 of the supply substrate 300 have a first spacing IN1. Furthermore, their relative positions can be aligned so that the plurality of third LEDs 150 of the third wafer 230 and the plurality of first LEDs 130 and the plurality of second LEDs 140 of the supply substrate 300 have a first spacing IN1. Therefore, the alignment error range and dispersion of the plurality of first LEDs 130 used as a reference during the primary transfer process can be eliminated. Furthermore, the plurality of second LEDs 140 and the plurality of third LEDs 150, which are aligned with the relative positions of the plurality of first LEDs 130, can have only minimal alignment error range and dispersion. Moreover, even in the secondary transfer process, the second alignment key AK2, which has already served as a reference for the alignment of the plurality of first LEDs 130, the plurality of second LEDs 140, and the plurality of third LEDs 150, is also used as a reference member. Therefore, the alignment error range and dispersion of the plurality of first LEDs 130, the plurality of second LEDs 140, and the plurality of third LEDs 150 caused by alignment errors can be minimized. Furthermore, according to Exemplary Embodiment 2, in the display device 100 according to the exemplary embodiment of this disclosure, based on the second alignment key AK2 transferred together with the plurality of LEDs (EDs), the relative positions of the other LEDs (EDs) are aligned with the LEDs (EDs) disposed on the supply substrate 300.Therefore, each of the multiple LEDs (EDs) can be set to correspond to the spacing between multiple sub-pixels, and the alignment accuracy of the multiple LEDs (EDs) can be improved.

[0200] In the manufacturing method of the display device 100 according to an exemplary embodiment of the present disclosure, a high-resolution display device 100 can be manufactured by precisely aligning a plurality of micro LEDs (EDs). As the size of the plurality of LEDs (EDs) decreases, higher quality images can be displayed, which can be beneficial for achieving high resolution. However, as the size of the plurality of LEDs (EDs) decreases, it becomes difficult to align each of the plurality of LEDs (EDs) during the transfer of the plurality of LEDs (EDs), and the alignment accuracy can be reduced. However, in the manufacturing method of the display device 100 according to an exemplary embodiment of the present disclosure, the relative positions of the plurality of LEDs (EDs) on the supply substrate 300 and the plurality of LEDs (EDs) on the wafer 200 are aligned, rather than the relative positions between the supply substrate 300 and the wafer 200. Therefore, the alignment accuracy of the plurality of LEDs (EDs) transferred to the supply substrate 300 can be improved. Therefore, even if the plurality of LEDs (EDs) have a small size, the plurality of LEDs (EDs) can be easily aligned, and a high-resolution display device 100 can be easily manufactured.

[0201] Traditionally, only LEDs emitting light of the same color are transferred to a supply substrate, and then transferred a second time to the display panel. In this case, a second alignment bond from the wafer is transferred to the supply substrate for alignment between the supply substrate and the display panel. However, it is difficult to transfer the second alignment bond using the same mask and laser as for multiple LEDs. Therefore, a separate process for transferring the second alignment bond to the supply substrate is performed. For example, the second alignment bond of the first wafer is transferred to one supply substrate to align the supply substrate and the display panel, the second alignment bond of the second wafer is transferred to another supply substrate to align the supply substrate and the display panel, and the second alignment bond of the third wafer is transferred to yet another supply substrate to align the supply substrate and the display panel. Therefore, in order to align each of one supply substrate, another supply substrate, and yet another supply substrate with the display panel, a separate process for transferring the second alignment bond is required, thus increasing the transfer process time and cost.

[0202] However, in the manufacturing method of the display device 100 according to the exemplary embodiment of the present disclosure, process time and cost can be reduced by shortening the time required for a single transfer step. First, in the manufacturing method of the display device 100 according to the exemplary embodiment of the present disclosure, multiple LEDs (EDs) from multiple wafers 200 are transferred to a supply substrate 300 in one step. In this case, multiple second alignment keys AK2 can be transferred from one wafer 200 where the first transfer step is performed to the supply substrate 300. Then, when multiple LEDs (EDs) from other wafers 200 are transferred to the supply substrate 300 during a single transfer step, since the second alignment keys AK2 are already set on the supply substrate 300, there is no need to transfer the second alignment keys AK2. Conventionally, the second alignment keys AK2 need to be transferred three times during a single transfer step. However, according to the present disclosure, the second alignment keys AK2 are transferred only once during a single transfer step, making it easy to align the supply substrate 300 and the display panel PN during a second transfer step. Therefore, in the manufacturing method of the display device 100 according to an exemplary embodiment of the present disclosure, some steps for transferring a plurality of second alignment keys AK2 to the supply substrate 300 are omitted. As a result, processing time and cost can be reduced.

[0203] In the manufacturing method of the display device 100 according to an exemplary embodiment of the present disclosure, a plurality of first LEDs 130, a plurality of second LEDs 140, and a plurality of third LEDs 150 are transferred onto a supply substrate 300 to correspond to a plurality of sub-pixels, respectively. Therefore, the secondary transfer process can be simplified. Conventionally, only one type of LED emitting light of the same color is transferred to a supply substrate once, and then transferred a second time to a display panel. Therefore, in order to form a pixel including the first LED, the second LED, and the third LED, each of the primary and secondary transfer processes needs to be performed at least three times. However, in the manufacturing method of the display device 100 according to an exemplary embodiment of the present disclosure, a plurality of first LEDs 130, a plurality of second LEDs 140, and a plurality of third LEDs 150 are transferred onto a supply substrate 300 once to correspond to a plurality of sub-pixels, and the plurality of first LEDs 130, a plurality of second LEDs 140, and a plurality of third LEDs 150 disposed on the supply substrate 300 are transferred to the display panel PN once. Therefore, the display device 100 can be manufactured. Therefore, a pixel PX including a first LED 130, a second LED 140, and a third LED 150 can be formed by performing one transfer process three times and a second transfer process once. Thus, in the manufacturing method of the display device 100 according to an exemplary embodiment of this disclosure, productivity and yield can be improved by forming an integrated supply substrate 300 on which multiple LEDs (EDs) are transferred corresponding to multiple sub-pixels.

[0204] Figures 12a to 12e This is a process flow diagram illustrating a method for manufacturing a display device according to another exemplary embodiment of the present disclosure. Figure 13 This is a process flow diagram illustrating a method for manufacturing a display device according to another exemplary embodiment of the present disclosure. Specifically, Figures 12a to 12e It is a schematic process diagram used to illustrate a single transfer process, while Figure 13 It is a schematic process diagram used to illustrate the secondary transfer process. Figures 12a to 13 The manufacturing method of the display device shown is the same as Figures 1 to 7 The manufacturing method of the display device shown is basically the same except for the following: the reference component used to align the wafer 200 with the supply substrate 300 and the supply substrate 300 with the display panel PN is one of a plurality of LEDs (EDs). Therefore, its redundant description will be omitted.

[0205] Reference Figure 12a and Figure 12b After completing a transfer process of multiple first LEDs 130 from the first wafer 210 to the supply substrate 300, multiple second LEDs 140 of the second wafer 220 are transferred to the supply substrate 300.

[0206] When the supply substrate 300 and the second wafer 220 are configured such that the plurality of protrusions 331 of the supply substrate 300 and the plurality of second LEDs 140 of the second wafer 220 face each other, the supply substrate 300 and the second wafer 220 can be aligned.

[0207] In this configuration, the supply substrate 300 and the second wafer 220 can be aligned based on some of the plurality of first LEDs 130 transferred from the first wafer 210 to the supply substrate 300 and any of the components of the second wafer 220. For example, the second wafer 220 and the supply substrate 300 can be aligned based on some of the plurality of first LEDs 130 transferred from the first wafer 210 to the supply substrate 300 and a first alignment key AK1 or a second alignment key AK2 of the second wafer 220, or the second wafer 220 and the supply substrate 300 can be aligned based on some of the plurality of first LEDs 130 transferred to the supply substrate 300 and some of the plurality of second LEDs 140 of the second wafer 220.

[0208] For example, when the second wafer 220 and the supply substrate 300 are aligned based on the first LED 130 of the supply substrate 300 and the second alignment key AK2 of the second wafer 220, the second wafer 220 and the supply substrate 300 can be aligned such that the center of the first LED 130 matches the center of the second alignment key AK2. Then, the supply substrate 300 and the second wafer 220 can be aligned by translating the second wafer 220 or the supply substrate 300 so that the active region 200A of the second wafer 220 and the transfer region 330A of the supply substrate 300 correspond to each other.

[0209] For example, when the second wafer 220 and the supply substrate 300 are aligned based on the first LED 130 of the supply substrate 300 and the second LED 140 of the second wafer 220, the second wafer 220 and the supply substrate 300 can be aligned such that the center of the first LED 130 matches the center of the second LED 140. In this case, depending on the position of the first LED 130 and the second LED 140 used as reference members, the supply substrate 300 and the second wafer 220 can be aligned by translating the second wafer 220 or the supply substrate 300 so that the active region 200A of the second wafer 220 and the transfer region 330A of the supply substrate 300 correspond to each other, or the process of translating the second wafer 220 or the supply substrate 300 can be omitted.

[0210] In this case, the center of the first LED 130 can be defined as the center of the shape formed by the edges of the first LED 130 when viewed from above as a reference member. For example, when viewed from above as a reference member, the edges of the first LED 130 can form a square, and the supply substrate 300 and the second wafer 220 can be aligned based on the center of the square.

[0211] Reference Figure 12c After the alignment between the second wafer 220 and the supply substrate 300 is completed, the second wafer 220 can be translated by the first gap IN1. After the second wafer 220 is translated by the first gap IN1 (i.e., the gap between the multiple sub-pixels), the multiple second LEDs 140 are transferred to the supply substrate 300.

[0212] Then, refer to Figure 12d and Figure 12e After completing one transfer process of multiple second LEDs 140, multiple third LEDs 150 of the third wafer 230 are transferred to the supply substrate 300.

[0213] First, refer to Figure 12d When the supply substrate 300 and the third wafer 230 are configured such that the plurality of protrusions 331 of the supply substrate 300 and the plurality of third LEDs 150 of the third wafer 230 face each other, the supply substrate 300 and the third wafer 230 can be aligned.

[0214] In this configuration, the supply substrate 300 and the third wafer 230 can be aligned based on some of the plurality of first LEDs 130 transferred from the first wafer 210 to the supply substrate 300 and any of the components of the third wafer 230. For example, the third wafer 230 and the supply substrate 300 can be aligned based on some of the plurality of first LEDs 130 transferred from the first wafer 210 to the supply substrate 300 and a first alignment key AK1 or a second alignment key AK2 of the third wafer 230, and the second wafer 220 and the supply substrate 300 can be aligned based on some of the plurality of first LEDs 130 transferred to the supply substrate 300 and some of the plurality of second LEDs 140 of the second wafer 220.

[0215] Reference Figure 12e After the alignment between the third wafer 230 and the supply substrate 300 is completed, the third wafer 230 can be shifted by the second gap IN2. That is, after the third wafer 230 is shifted by the first gap IN1 twice, a plurality of third LEDs 150 are transferred to the supply substrate 300.

[0216] In this configuration, a plurality of first LEDs 130, a plurality of second LEDs 140, and a plurality of third LEDs 150 transferred to the supply substrate 300 can be transferred to the display panel PN in a single transfer at a first interval IN1, where IN1 is the spacing between the plurality of first LEDs 130. Therefore, when the plurality of second LEDs 140 and the plurality of third LEDs 150 are transferred to the supply substrate 300, the second wafer 220 and the third wafer 230 can be aligned with the supply substrate 300 by using some of the plurality of first LEDs 130 on the supply substrate 300 as reference members. Furthermore, the relative positions between the plurality of first LEDs 130, the plurality of second LEDs 140, and the plurality of third LEDs 150 can be aligned.

[0217] Furthermore, when multiple first LEDs 130 are transferred from the first wafer 210 to the supply substrate 300, the second alignment key AK2 may or may not be transferred. Similarly, when multiple LEDs (EDs) are transferred from the supply substrate 300 to the display panel PN, the second alignment key AK2 may or may not be transferred. In a method for manufacturing a display device according to another exemplary embodiment of this disclosure, when the supply substrate 300 and the display panel PN are aligned, the first LEDs 130 are used instead of the second alignment key AK2 as a reference member. Therefore, the second alignment key AK2 can be selectively transferred.

[0218] The plurality of second LEDs 140 and third LEDs 150 disposed on the supply substrate 300 are transferred not based on the first alignment protrusion 333 of the supply substrate 300, but based on some of the plurality of first LEDs 130 transferred from the first wafer 210 to the supply substrate 300. The relative positions of the plurality of second LEDs 140 and third LEDs 150 to the plurality of first LEDs 130 can be aligned. Therefore, the plurality of first LEDs 130, the plurality of second LEDs 140, and the plurality of third LEDs 150 can be disposed on the supply substrate 300 to correspond to a plurality of sub-pixels. Furthermore, when the plurality of first LEDs 130, the plurality of second LEDs 140, and the plurality of third LEDs 150 are transferred to the display panel PN, the supply substrate 300 and the display panel PN can be aligned based on the plurality of first LEDs 130 to transfer the plurality of first LEDs 130, the plurality of second LEDs 140, and the plurality of third LEDs 150. In this case, multiple first LEDs 130, multiple second LEDs 140, and multiple third LEDs 150 can each correspond to multiple sub-pixels being transferred.

[0219] Therefore, in a method for manufacturing a display device according to another exemplary embodiment of this disclosure, the second wafer 220 and the third wafer 230 can be aligned with the supply substrate 300 based on some of the plurality of first LEDs 130 firstly transferred onto the supply substrate 300. This improves the alignment accuracy of the plurality of first LEDs 130, the plurality of second LEDs 140, and the plurality of third LEDs 150. Specifically, without separate components for aligning the wafer 200 with the supply substrate 300 and aligning the supply substrate 300 with the display panel PN, the supply substrate 300 can be aligned with the wafer 200 and the display panel PN based on one of the plurality of first LEDs 130. This simplifies the structure of the wafer 200, the supply substrate 300, and the display panel PN, and simplifies the transfer process of the second alignment key AK2. The second alignment key AK2 can have a different shape than the plurality of LEDs (EDs) and can be transferred separately. That is, since the second alignment key AK2 has a different shape than the plurality of first LEDs 130, the mask or laser used in the transfer process can be different. Furthermore, it is difficult to simultaneously transfer the second alignment key AK2 and the plurality of first LEDs 130, and the second alignment key AK2 can be transferred in a process separate from the plurality of first LEDs 130. However, in a method for manufacturing a display device according to another exemplary embodiment of the present disclosure, the plurality of LEDs (EDs) themselves serve as reference members for aligning the wafer 200 with the supply substrate 300 and the supply substrate 300 with the display panel PN. Therefore, the transfer process of the second alignment key AK2 can be simplified, and the structure of the wafer 200 and the supply substrate 300 can be simplified.

[0220] Exemplary embodiments of this disclosure can also be described as follows:

[0221] According to one aspect of this disclosure, a method for manufacturing a display device is provided. The method includes: aligning a first wafer having a plurality of first LEDs, a plurality of alignment keys, and a reference component disposed thereon with a supply substrate; transferring the plurality of first LEDs and the reference component from the first wafer to the supply substrate; and aligning a second wafer having a plurality of second LEDs disposed thereon with the supply substrate based on the reference component.

[0222] In the process of aligning the first wafer with the supply substrate, the first wafer can be basically aligned with the supply substrate based on the first alignment key among the multiple alignment keys of the first wafer and the first alignment protrusion of the supply substrate.

[0223] The method for manufacturing a display device may further include: a step of transferring a plurality of second LEDs on a second wafer to a supply substrate on which a plurality of first LEDs are disposed; a step of aligning a third wafer on which a plurality of third LEDs are disposed with the supply substrate based on a reference member; and a step of transferring a plurality of third LEDs on a third wafer to a supply substrate on which a plurality of first LEDs and a plurality of second LEDs are disposed.

[0224] The method for manufacturing a display device may further include: a step of translating a second wafer aligned with the supply substrate based on a reference member before a step of transferring a plurality of second LEDs to a supply substrate; and a step of translating a third wafer aligned with the supply substrate based on a reference member before a step of transferring a plurality of third LEDs to the supply substrate.

[0225] The plurality of first LEDs, the plurality of second LEDs and the plurality of third LEDs disposed on the supply substrate can be arranged at a first interval.

[0226] The second wafer can be translated to the first gap and the third wafer can be translated to the second gap in the same direction as the translation direction of the second wafer. The second gap is larger than the first gap. On the supply substrate, a plurality of second LEDs can be transferred to one side of a plurality of first LEDs respectively, and a plurality of third LEDs can be transferred to one side of a plurality of second LEDs respectively.

[0227] The second wafer can be translated by a first gap, and the third wafer can be translated by the first gap in the opposite direction to the translation direction of the second wafer. On the supply substrate, a plurality of second LEDs can be transferred to one side of a plurality of first LEDs, and a plurality of third LEDs can be transferred to the other side of a plurality of first LEDs.

[0228] The manufacturing method of the display device may further include: a step of aligning a supply substrate on which a plurality of first LEDs, a plurality of second LEDs and a plurality of third LEDs are disposed, with a display panel based on a reference member; and a step of transferring the plurality of first LEDs, a plurality of second LEDs and a plurality of third LEDs disposed on the supply substrate to the display panel.

[0229] The reference component may be at least one of a plurality of first LEDs transferred onto the supply substrate.

[0230] The reference component may be a second alignment key among a plurality of alignment keys disposed on the first wafer, which is transferred to the supply substrate together with a plurality of first LEDs.

[0231] In the process of aligning the second wafer with the supply substrate, the second wafer can be aligned with the supply substrate based on at least one of the plurality of second LEDs of the second wafer and a reference component.

[0232] In the process of aligning the second wafer with the supply substrate, the second wafer can be aligned with the supply substrate based on at least one of a plurality of alignment keys of the second wafer and a reference member.

[0233] According to another aspect of this disclosure, there is a method for manufacturing a display device. The method includes: aligning a first wafer having a reference member and a plurality of first LEDs disposed thereon with a supply substrate; transferring the plurality of first LEDs and the reference member from the first wafer to the supply substrate; aligning a second wafer having a plurality of second LEDs disposed thereon with the supply substrate based on the reference member transferred to the supply substrate; transferring the plurality of second LEDs from the second wafer to the supply substrate; aligning a third wafer having a plurality of third LEDs disposed thereon with the supply substrate based on the reference member transferred to the supply substrate; and transferring the plurality of third LEDs from the third wafer to the supply substrate.

[0234] The reference component can be one of a plurality of first LEDs.

[0235] It may further include a plurality of alignment keys disposed on the first wafer together with a plurality of first LEDs. The plurality of alignment keys may include a first alignment key aligned with an alignment protrusion of a supply substrate and a second alignment key serving as a reference member. The first alignment key may have a different size than the second alignment key.

[0236] The first LED among a plurality of first LEDs located at the shortest distance from the second alignment key can have a constant interval with the second alignment key.

[0237] In the process of transferring multiple second LEDs to the supply substrate, a second wafer can be translated, and then multiple second LEDs can be transferred. In the process of transferring multiple third LEDs to the supply substrate, a third wafer can be translated in a different direction than the second wafer at a different interval, and then multiple third LEDs can be transferred.

[0238] In the process of aligning the second wafer with the supply substrate, the relative positions of a plurality of first LEDs disposed on the supply substrate and a plurality of second LEDs disposed on the second wafer can be aligned. In the process of aligning the third wafer with the supply substrate, the relative positions of a plurality of first LEDs and a plurality of second LEDs disposed on the supply substrate and a plurality of third LEDs disposed on the third wafer can be aligned.

[0239] The method for manufacturing a display device may further include: a step of aligning a supply substrate on which a plurality of first LEDs, a plurality of second LEDs and a plurality of third LEDs are disposed, with a display panel based on a reference member transferred to a supply substrate; and a step of transferring each of the plurality of first LEDs, a plurality of second LEDs and a plurality of third LEDs on the supply substrate to the display panel to correspond to each of the first sub-pixel, the second sub-pixel and the third sub-pixel of the display panel.

[0240] Although exemplary embodiments of the present disclosure have been described in detail with reference to the accompanying drawings, the present disclosure is not limited thereto and may be implemented in many different forms without departing from the technical concept of the present disclosure. Therefore, the exemplary embodiments of the present disclosure are provided for illustrative purposes only and are not intended to limit the technical concept of the present disclosure. The scope of the technical concept of the present disclosure is not limited thereto. Therefore, it should be understood that the above exemplary embodiments are exemplary in all respects and do not limit the present disclosure. The scope of protection of the present disclosure should be interpreted based on the appended claims, and all technical concepts within their equivalent scope should be understood to fall within the scope of protection of the present disclosure.

Claims

1. A method for manufacturing a display device, the method comprising the following steps: Align the first wafer, on which a plurality of first light-emitting diodes (LEDs), a plurality of alignment keys, and reference components are disposed, with the supply substrate; The plurality of first LEDs and the reference component on the first wafer are transferred to the supply substrate; Based on the reference component, the second wafer on which a plurality of second LEDs are disposed is aligned with the supply substrate; The plurality of second LEDs on the second wafer are transferred to the supply substrate on which the plurality of first LEDs are disposed; Align the third wafer, on which a plurality of third LEDs are disposed, with the supply substrate based on the reference component; as well as The plurality of third LEDs on the third wafer are transferred to the supply substrate on which the plurality of first LEDs and the plurality of second LEDs are disposed. Wherein, the second wafer is translated by a first interval and the third wafer is translated by a second interval in the same direction as the translation direction of the second wafer, the second interval being larger than the first interval, and On the supply substrate, the plurality of second LEDs are respectively transferred to one side of the plurality of first LEDs, and the plurality of third LEDs are respectively transferred to one side of the plurality of second LEDs.

2. The method for manufacturing a display device according to claim 1, wherein When aligning the first wafer with the supply substrate, the first wafer is aligned with the supply substrate based on the first alignment key among the plurality of alignment keys of the first wafer and the first alignment protrusion of the supply substrate.

3. The method for manufacturing a display device according to claim 1, wherein The second wafer, aligned with the supply substrate, and the third wafer, aligned with the supply substrate, are translated based on the reference component.

4. The method for manufacturing a display device according to claim 3, wherein, The plurality of first LEDs, the plurality of second LEDs, and the plurality of third LEDs disposed on the supply substrate are arranged at a first interval.

5. The method for manufacturing a display device according to claim 1, further comprising the following steps: Align the supply substrate, on which the plurality of first LEDs, the plurality of second LEDs and the plurality of third LEDs are disposed, with the display panel based on the reference component; as well as The plurality of first LEDs, the plurality of second LEDs, and the plurality of third LEDs disposed on the supply substrate are transferred to the display panel.

6. The method for manufacturing a display device according to claim 1, wherein, The reference component is at least one of the plurality of first LEDs that are transferred onto the supply substrate.

7. The method for manufacturing a display device according to claim 1, wherein, The reference component is a second alignment key among the plurality of alignment keys disposed on the first wafer, which is transferred to the supply substrate together with the plurality of first LEDs.

8. The method for manufacturing a display device according to claim 1, wherein, When aligning the second wafer with the supply substrate, the second wafer is aligned with the supply substrate based on at least one of the plurality of second LEDs of the second wafer and the reference member of the supply substrate.

9. The method for manufacturing a display device according to claim 1, wherein, When aligning the second wafer with the supply substrate, the second wafer is aligned with the supply substrate based on at least one of the plurality of alignment keys of the second wafer and the reference member of the supply substrate.

10. A method for manufacturing a display device, the method comprising the following steps: Align the first wafer, on which a plurality of first light-emitting diodes (LEDs), a plurality of alignment keys, and reference components are disposed, with the supply substrate; The plurality of first LEDs and the reference component on the first wafer are transferred to the supply substrate; Based on the reference component, the second wafer on which a plurality of second LEDs are disposed is aligned with the supply substrate; The plurality of second LEDs on the second wafer are transferred to the supply substrate on which the plurality of first LEDs are disposed; Align the third wafer, on which a plurality of third LEDs are disposed, with the supply substrate based on the reference component; as well as The plurality of third LEDs on the third wafer are transferred to the supply substrate on which the plurality of first LEDs and the plurality of second LEDs are disposed. The second wafer is translated by a first interval, and the third wafer is translated by the first interval in a direction opposite to the translation direction of the second wafer. On the supply substrate, the plurality of second LEDs are respectively transferred to one side of the plurality of first LEDs, and the plurality of third LEDs are respectively transferred to the other side of the plurality of first LEDs.

11. A method for manufacturing a display device, the method comprising the following steps: Align the first wafer, on which a reference component and multiple first light-emitting diodes (LEDs) are disposed, with the supply substrate; The plurality of first LEDs and the reference component of the first wafer are transferred to the supply substrate; Based on the reference member transferred to the supply substrate, a second wafer on which a plurality of second LEDs are disposed is aligned with the supply substrate; The plurality of second LEDs of the second wafer are transferred to the supply substrate; Based on the reference member transferred to the supply substrate, a third wafer on which a plurality of third LEDs are disposed is aligned with the supply substrate. as well as The plurality of third LEDs on the third wafer are transferred to the supply substrate. Among them, multiple alignment keys are disposed on the first wafer together with the multiple first LEDs. The plurality of alignment keys include a first alignment key aligned with the alignment protrusion of the supply substrate and a second alignment key serving as the reference member, and The first alignment key has a different size than the second alignment key.

12. The method of manufacturing a display device according to claim 11, wherein, The reference component is one of the plurality of first LEDs.

13. The method of manufacturing a display device according to claim 11, wherein, The first LED among the plurality of first LEDs located at the shortest distance from the second alignment key has a constant interval with the second alignment key.

14. The method of manufacturing a display device according to claim 11, wherein, When aligning the second wafer with the supply substrate, the relative positions of the plurality of first LEDs disposed on the supply substrate and the plurality of second LEDs disposed on the second wafer are aligned, and When aligning the third wafer with the supply substrate, the relative positions of the plurality of first LEDs and the plurality of second LEDs disposed on the supply substrate are aligned with those of the plurality of third LEDs disposed on the third wafer.

15. The method of manufacturing a display device according to claim 11, further comprising the following steps: Based on the reference member transferred to the supply substrate, the supply substrate on which the plurality of first LEDs, the plurality of second LEDs and the plurality of third LEDs are disposed is aligned with the display panel; as well as Each of the plurality of first LEDs, the plurality of second LEDs, and the plurality of third LEDs on the supply substrate is transferred to the display panel to correspond to each of the first sub-pixel, the second sub-pixel, and the third sub-pixel of the display panel.

16. A method for manufacturing a display device, the method comprising the following steps: Align the first wafer, on which a reference component and multiple first light-emitting diodes (LEDs) are disposed, with the supply substrate; The plurality of first LEDs and the reference component of the first wafer are transferred to the supply substrate; Based on the reference member transferred to the supply substrate, a second wafer on which a plurality of second LEDs are disposed is aligned with the supply substrate; The plurality of second LEDs of the second wafer are transferred to the supply substrate; Based on the reference member transferred to the supply substrate, a third wafer on which a plurality of third LEDs are disposed is aligned with the supply substrate. as well as The plurality of third LEDs on the third wafer are transferred to the supply substrate. Specifically, when transferring the plurality of second LEDs to the supply substrate, the second wafer is translated, and then the plurality of second LEDs are transferred. When transferring the plurality of third LEDs to the supply substrate, the third wafer is translated in the same direction as the translation direction of the second wafer but at a different interval than the second wafer, or in a different direction but at the same interval as the second wafer, and then the plurality of third LEDs are transferred.

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