Transfer method of light emitting chip, display panel and display device

Abstract

This application relates to a method for transferring light-emitting chips. The method includes: providing an epitaxial wafer, obtaining a plurality of light-emitting chips through the epitaxial wafer, the light-emitting chips being connected by semiconductor segments; fabricating adhesive pillars on the plurality of semiconductor segments on the epitaxial wafer; providing a first temporary substrate disposed at one end of the adhesive pillars opposite to the semiconductor segments; removing a substrate layer on the epitaxial wafer to form a wafer source including the plurality of light-emitting chips; removing the connections between the light-emitting chips and the semiconductor segments, transferring the plurality of light-emitting chips in the wafer source to a backplane, the plurality of light-emitting chips being electrically connected to the backplane. The method for transferring light-emitting chips solves the problem that light-emitting chips cannot be easily grasped by elastic molds. This application also provides a display panel and a display device having the display panel.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a method for transferring a light-emitting chip, a display panel, and a display device having the display panel. Background Technology

[0002] Micro LEDs, as a next-generation display technology, offer advantages over traditional LEDs, including self-illumination, higher photoelectric efficiency, higher brightness, higher contrast, and lower power consumption. With the maturation of manufacturing processes and the decrease in prices, display products based on micro LEDs have become increasingly common in recent years, such as television and mobile phone screens. Because display products have a low tolerance for pixel errors, improving the yield rate of micro LED transfer is crucial for improving the overall yield of display products.

[0003] Currently, common transfer methods for micro-light-emitting chips include electrostatic force, van der Waals force, magnetic force, laser selective transfer, fluid transfer, and direct transfer. Among these, van der Waals force is the most widely used method, employing an elastic imprint to selectively pick up and transfer the micro-light-emitting chip to the substrate. For successful transfer, the prepared micro-light-emitting chip must be readily adsorbed by the elastomer and detached from the original substrate. This requires the micro-light-emitting chip to have a "hollowed-out" structure underneath, with the chip fixed to the substrate only by anchor points and fracture chains. After the elastomer material is sprayed, the elastomer binds to the micro-light-emitting chip through van der Waals forces. Then, the elastomer separates from the substrate, at which point the fracture chains of the micro-light-emitting chip break, and all the micro-light-emitting chips are transferred to the elastomer according to their original array arrangement. However, since the "hollowed-out" structure under the micro-light-emitting chip constitutes the transfer substrate, the quality of the transfer substrate determines the yield rate of the micro-light-emitting chip transfer. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this application is to provide a method for transferring light-emitting chips, a display panel, and a display device having the display panel, which aims to solve the problem in the prior art that micro light-emitting chips cannot be easily grasped by elastic molds.

[0005] A method for transferring light-emitting chips, the method comprising: providing an epitaxial wafer, obtaining a plurality of light-emitting chips through the epitaxial wafer, the light-emitting chips being connected to each other by semiconductor segments; fabricating adhesive pillars on the plurality of semiconductor segments on the epitaxial wafer; providing a first temporary substrate, the first temporary substrate being disposed at one end of the adhesive pillars opposite to the semiconductor segments; removing a substrate layer on the epitaxial wafer to form a wafer source including the plurality of light-emitting chips; removing the connections between the light-emitting chips and the semiconductor segments; transferring the plurality of light-emitting chips in the wafer source to a backplane, the plurality of light-emitting chips being electrically connected to the backplane.

[0006] In summary, the light-emitting chip transfer method of this application solves the problem in the prior art that light-emitting chips cannot be easily grasped by elastic molds, thereby increasing the mass transfer yield of the light-emitting chips.

[0007] Optionally, providing an epitaxial wafer to obtain multiple light-emitting chips, wherein the light-emitting chips are connected to each other via the semiconductor segment, includes: providing an epitaxial wafer comprising multiple epitaxial structures; forming multiple openings on the epitaxial wafer, each opening corresponding to one epitaxial structure, and forming a first region and a second region for the epitaxial structures; forming multiple slots on the epitaxial wafer, each slot being disposed between two adjacent epitaxial structures, and the bottom of the slot being located within a first semiconductor layer of the epitaxial wafer to recess the first semiconductor layer to form a semiconductor segment; forming a metal layer on a second semiconductor layer of the epitaxial wafer located in the first region; forming an insulating protective layer covering the metal layer and part of the epitaxial wafer to partially expose the semiconductor segment; partially removing the insulating protective layer covering the metal layer and the first semiconductor layer to partially expose the metal layer and the first semiconductor layer; forming a first electrode and a second electrode at the positions where the metal layer and the first semiconductor layer located within the openings are exposed, respectively, the first electrode being electrically connected to the metal layer and the second electrode being electrically connected to the first semiconductor layer, to obtain multiple light-emitting chips.

[0008] Optionally, removing the connection between the light-emitting chip and the semiconductor segment, and transferring the plurality of light-emitting chips in the wafer source to a backplane, wherein the plurality of light-emitting chips are electrically connected to the backplane, includes: grasping the wafer source and disconnecting the plurality of light-emitting chips in the wafer source from the semiconductor segment; providing a second temporary substrate and transferring the plurality of light-emitting chips in the wafer source to the second temporary substrate; transferring the plurality of light-emitting chips from the second temporary substrate to the backplane, wherein the first electrode and the second electrode of the plurality of light-emitting chips are electrically connected to the backplane.

[0009] Optionally, the step of grasping the wafer source and disconnecting the plurality of light-emitting chips in the wafer source from the semiconductor segment includes: grasping the wafer source with a transfer head and pressing the transfer head toward the light-emitting chip to break the semiconductor segment between the light-emitting chip and the adhesive post.

[0010] Optionally, the epitaxial structure includes the substrate layer, the first semiconductor layer, the multi-quantum well light-emitting layer, and the second semiconductor layer stacked sequentially. Each opening penetrates the second semiconductor layer and the multi-quantum well light-emitting layer and communicates with the first semiconductor layer. Each slot penetrates the second semiconductor layer and the multi-quantum well light-emitting layer sequentially and is recessed into the first semiconductor layer. The portion of the first semiconductor layer adjacent to the multi-quantum well light-emitting layer is etched, and the remaining portion of the first semiconductor layer is not etched to form the semiconductor segment.

[0011] Optionally, each of the semiconductor segments is provided with adhesive pillars, and adhesive pillars are provided on opposite sides of each light-emitting chip. The height of the adhesive pillars is greater than the height of the light-emitting chip, and the light-emitting chip is spaced apart from the first temporary substrate by a predetermined distance.

[0012] Optionally, the thickness of the metal layer is 200-2000 Å, the thickness of the insulating protective layer is 1-4 μm, and the thickness of the first electrode and the second electrode is 1-4 μm.

[0013] Optionally, the metal layer is made of indium tin oxide, the adhesive column is made of benzocyclobutene, and the insulating protective layer is a distributed Bragg mirror.

[0014] In summary, in the chip transfer method of this application, the semiconductor segment of the light-emitting chip itself serves as a support connection layer. This semiconductor segment connects the light-emitting chip to the adhesive pillar. Controlling the thickness of the semiconductor segment controls the connection force between the light-emitting chip and the adhesive pillar, achieving adjustable connection force. Simultaneously, the transfer head breaks the semiconductor segment to transfer the light-emitting chip, solving the problem in the prior art where the light-emitting chip cannot be easily grasped by the elastic mold, thereby increasing the yield of mass transfers of the light-emitting chip.

[0015] Based on the same inventive concept, this application also provides a display panel, which includes a back plate and a plurality of light-emitting chips transferred to the back plate by the above-described light-emitting chip transfer method.

[0016] In summary, in the display panel of this application, the semiconductor segment of the light-emitting chip itself serves as a support and connection layer. This semiconductor segment connects the light-emitting chip to the adhesive pillar. Controlling the thickness of the semiconductor segment controls the connection force between the light-emitting chip and the adhesive pillar, achieving adjustable connection force. Simultaneously, the transfer head breaks the semiconductor segment to transfer the light-emitting chip, solving the problem in the prior art where the light-emitting chip cannot be easily grasped by the elastic mold, thereby increasing the yield of mass transfers of the light-emitting chip.

[0017] Based on the same inventive concept, this application also provides a display device, which includes a support frame and the above-described display panel, wherein the support frame is used to support the display panel.

[0018] In summary, in the display device of this application, the semiconductor segment connects the light-emitting chip to the adhesive pillar. Controlling the thickness of the semiconductor segment controls the connection force between the light-emitting chip and the adhesive pillar, achieving adjustable connection force. Simultaneously, the transfer head breaks the semiconductor segment to transfer the light-emitting chip, solving the problem in the prior art where the light-emitting chip cannot be easily grasped by the elastic mold, thereby increasing the yield of mass transfers of the light-emitting chip. Attached Figure Description

[0019] Figure 1 This is a schematic flowchart of a method for transferring a light-emitting chip disclosed in an embodiment of this application;

[0020] Figure 2 for Figure 1 A flowchart illustrating step S100 in the method for transferring the light-emitting chip shown.

[0021] Figure 3 for Figure 2 A schematic diagram of the corresponding structure formed in step S110 of the preparation method shown;

[0022] Figure 4 for Figure 2 A schematic diagram of the corresponding structure formed in step S120 of the preparation method shown;

[0023] Figure 5 for Figure 2 A schematic diagram of the corresponding structure formed in step S130 of the preparation method shown;

[0024] Figure 6 for Figure 2 A schematic diagram of the corresponding structure formed in step S140 of the preparation method shown;

[0025] Figure 7 for Figure 2 A schematic diagram of the corresponding structure formed in step S150 of the preparation method shown;

[0026] Figure 8 for Figure 2 A schematic diagram of the corresponding structure formed in step S160 of the preparation method shown;

[0027] Figure 9 for Figure 1 A schematic diagram of the corresponding structure formed in step S200 of the method for transferring the light-emitting chip shown;

[0028] Figure 10 for Figure 1 A schematic diagram of the corresponding structure formed in step S300 of the method for transferring the light-emitting chip shown;

[0029] Figure 11 for Figure 1 A schematic diagram of the corresponding structure formed in step S400 of the method for transferring the light-emitting chip shown;

[0030] Figure 12 for Figure 1 The flowchart of step S500 in the method for transferring the light-emitting chip is shown.

[0031] Figure 13 for Figure 12 A schematic diagram of the corresponding structure formed in step S510 of the method for transferring the light-emitting chip shown;

[0032] Figure 14 for Figure 12 A schematic diagram of the corresponding structure formed in step S520 of the method for transferring the light-emitting chip shown;

[0033] Figure 15 for Figure 13 A schematic diagram of the corresponding structure formed in step S530 of the light-emitting chip transfer method shown.

[0034] Explanation of reference numerals in the attached figures:

[0035] 200 - Epitaxial wafer;

[0036] 210 - Substrate layer;

[0037] 220 - First semiconductor layer;

[0038] 221 - Semiconductor segment;

[0039] 230-Multiple quantum well light-emitting layer;

[0040] 240 - Second semiconductor layer;

[0041] 260-Extensional structure;

[0042] 262-Opening;

[0043] 264 - First Region;

[0044] 265 - Second Region;

[0045] 266 - Grooving;

[0046] 300-Light Emitting Chip;

[0047] 310 - Metallic layer;

[0048] 320 - Insulation protective layer;

[0049] 340 - First electrode;

[0050] 350 - Second electrode;

[0051] 400-Glue Column;

[0052] 500 - First temporary substrate;

[0053] 600-source video;

[0054] 510 - Second temporary substrate;

[0055] 700-Transfer Head;

[0056] 800-backplate;

[0057] Steps of the transfer method for S100-S500 light-emitting chips;

[0058] Step S100 in the method for transferring light-emitting chips (S110-S160);

[0059] Step S500 in the method for transferring light-emitting chips (S510-S530) Detailed Implementation

[0060] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0061] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.

[0062] Currently, common transfer methods for micro-light-emitting chips include electrostatic force, van der Waals force, magnetic force, laser selective transfer, fluid transfer, and direct transfer. Among these, van der Waals force is the most widely used method, employing an elastic imprint to selectively pick up and transfer the micro-light-emitting chip to the substrate. For successful transfer, the prepared micro-light-emitting chip must be readily adsorbed by the elastomer and detached from the original substrate. This requires the micro-light-emitting chip to have a "hollowed-out" structure underneath, with the chip fixed to the substrate only by anchor points and fracture chains. After the elastomer material is sprayed, the elastomer binds to the micro-light-emitting chip through van der Waals forces. Then, the elastomer separates from the substrate, at which point the fracture chains of the micro-light-emitting chip break, and all the micro-light-emitting chips are transferred to the elastomer according to their original array arrangement. However, since the "hollowed-out" structure under the micro-light-emitting chip constitutes the transfer substrate, the quality of the transfer substrate determines the yield rate of the micro-light-emitting chip transfer.

[0063] Based on this, this application aims to provide a solution that can solve the above-mentioned technical problems, which can solve the problem that Micro light-emitting chips cannot be easily grasped by elastic molds, and improve the mass transfer yield of light-emitting chips. The details will be described in subsequent embodiments.

[0064] This application provides a detailed description of a chip transfer method, a display panel formed by the chip transfer method, and a display device having the display panel.

[0065] Please see Figure 1 This is a flowchart illustrating a method for transferring a light-emitting chip according to an embodiment of this application. In this embodiment, the method for transferring the light-emitting chip is used to transfer the chip, thereby increasing the yield of the transferred chip. Please refer to [further details omitted]. Figures 2 to 15 As shown in the embodiments of this application, the method for transferring the light-emitting chip may include at least the following steps.

[0066] S100. Provide an epitaxial wafer 200, and obtain a plurality of light-emitting chips 300 through the epitaxial wafer 200. The light-emitting chips are connected to each other through semiconductor segments 221.

[0067] Please refer to the following: Figure 2 In this embodiment, step S100 includes at least the following steps.

[0068] S110. Provide an epitaxial wafer 200 including a plurality of epitaxial structures 260, and form a plurality of openings 262 on the epitaxial wafer 200, each opening 262 corresponding to one epitaxial structure 260, and form a first region 264 and a second region 265 for the epitaxial structure 260.

[0069] In the embodiments of this application, such as Figure 3 As shown, the epitaxial wafer 200 includes a substrate layer 210, a first semiconductor layer 220, a multi-quantum-well light-emitting layer 230, and a second semiconductor layer 240 stacked sequentially. The first semiconductor layer 220 is disposed on the substrate layer 210 and provides electrons. The second semiconductor layer 240 is disposed on the multi-quantum-well light-emitting layer 230 and provides holes, which recombine with the electrons provided by the first semiconductor layer 220 to generate photons. The multi-quantum-well light-emitting layer 230 is disposed between the first semiconductor layer 220 and the second semiconductor layer 240, providing a space for the electrons provided by the first semiconductor layer 220 to recombine with the holes provided by the second semiconductor layer 240 to generate photons.

[0070] In this embodiment, the first semiconductor layer 220 is an N-type semiconductor material, such as N-type gallium nitride (GaN). The second semiconductor layer 240 is a P-type semiconductor material, such as P-type gallium nitride (GaN).

[0071] In an exemplary embodiment, the epitaxial wafer 200 includes a plurality of epitaxial structures 260 arranged in an array. Each epitaxial structure 260 also includes a substrate layer 210, a first semiconductor layer 220, a multi-quantum-well light-emitting layer 230, and a second semiconductor layer 240 stacked sequentially. The epitaxial wafer 200 forms a plurality of openings 262, each opening 262 corresponding to one of the epitaxial structures 260. In this embodiment, the opening 262 sequentially penetrates the second semiconductor layer 240 and the multi-quantum-well light-emitting layer 230 up to the first semiconductor layer 220, that is, the opening 262 communicates with the first semiconductor layer 220 and forms a groove with the first semiconductor layer 220 as the bottom, thereby forming a first region 264 and a second region 265 of the epitaxial structure 260. Optionally, the first region 264 is the region where a portion of the epitaxial structure 260 is located on one side of the opening 262, and the second region 265 is the region where a portion of the epitaxial structure 260 is located on the other side of the opening 262.

[0072] In an exemplary embodiment, a plurality of openings 262 on the epitaxial wafer 200 can be formed by photolithography, and the plurality of openings 262 on the epitaxial wafer 200 form a first pattern. In this embodiment, the first pattern can be a MESA (step-altered surface) pattern. In this embodiment, the photolithography is dry etching, and the etching gas for dry etching is BCl3 / Cl2.

[0073] S120. A plurality of slots 266 are formed on the epitaxial wafer 200. Each slot 266 is disposed between two adjacent epitaxial structures 260, and the bottom of the slot 266 is located within the first semiconductor layer 220 of the epitaxial wafer 200 to recess the first semiconductor layer 220 to form a semiconductor segment 221.

[0074] In the embodiments of this application, such as Figure 4 As shown, a plurality of slots 266 are formed on the epitaxial wafer 200, and each slot 266 is disposed between two adjacent epitaxial structures 260. The slot 266 sequentially penetrates the second semiconductor layer 240 and the multi-quantum well light-emitting layer 230, and continues to extend recessed into the first semiconductor layer 220. The portion of the first semiconductor layer 220 adjacent to the multi-quantum well light-emitting layer 230 is etched, and the remaining portion of the first semiconductor layer 220 is not etched to form a semiconductor segment 221. That is, the bottom of the slot 266 extends recessed into the portion of the first semiconductor layer 220 adjacent to the multi-quantum well light-emitting layer 230, and does not communicate with the substrate layer 210. In other words, the slot 266 and the substrate layer 210 are separated by the semiconductor segment 221. Alternatively, the slot 266 is formed between a second region 265 of an epitaxial structure 260 and a first region 264 of an adjacent epitaxial structure 260, and the semiconductor segment 221 is located between the second region 265 of an epitaxial structure 260 and the first region 264 of an adjacent epitaxial structure 260.

[0075] In an exemplary embodiment, the plurality of slots 266 on the epitaxial wafer 200 can be formed by photolithography, and the plurality of slots 266 on the epitaxial wafer 200 form a second pattern. For example, by using a dry etching machine to etch through the second semiconductor layer 240, the multi-quantum well light-emitting layer 230, and a portion of the first semiconductor layer 220, that is, by using a dry etching machine to etch through the second semiconductor layer 240, the multi-quantum well light-emitting layer 230, and a portion of the first semiconductor layer 220 to the semiconductor segment 221, the slots 266 form a groove with the semiconductor segment 221 as its bottom.

[0076] In this embodiment, the second pattern can be an ISO (GaN Deep Etching) pattern. The photolithography is dry etching, and the etching gas for dry etching is BCl3 / Cl2. The etching depth of the second pattern is 4-8 μm, for example, 4 μm, 5 μm, 6 μm, 7 μm, or other values. The thickness of the semiconductor segment 221 is 2000-10000 Å, for example, 2000 Å, 3000 Å, 4000 Å, 5000 Å, 8000 Å, 10000 Å, or other values.

[0077] S130, a metal layer 310 is formed on the second semiconductor layer 240 of the epitaxial wafer 200 located in the first region 264.

[0078] Specifically, in exemplary embodiments, such as Figure 5 As shown, the opening 262 extends through the second semiconductor layer 240 and the multi-quantum-well light-emitting layer 230 to the first semiconductor layer 220, thereby forming a first region 264 and a second region 265 on the epitaxial structure 260. A metal layer 310 is formed on the second semiconductor layer 240 located in the first region 264 of the epitaxial wafer 200. At this time, the metal layer 310 is electrically connected to the second semiconductor layer 240.

[0079] In an exemplary embodiment, the metal layer 310 may be made of indium tin oxide (ITO). The thickness of the metal layer 310 may be 200-2000 Å, for example 200 Å, 300 Å, 400 Å, 500 Å, 800 Å, 1500 Å, 1800 Å, or other values.

[0080] S140, an insulating protective layer 320 is formed covering the metal layer 310 and a portion of the epitaxial wafer 200 to partially expose the semiconductor segment 221.

[0081] Specifically, in the embodiments of this application, such as Figure 6 As shown, the insulating protective layer 320 can be a stack of silicon oxide and silicon nitride. For example, the insulating protective layer 320 can also be a distributed Bragg reflector (DBR). Exemplarily, the insulating protective layer 320 is formed by vapor deposition of a silicon oxide and silicon nitride stack (DBR) on a portion of the epitaxial wafer 200 and the metal layer 310. Here, "covering a portion of the epitaxial wafer 200" means that a portion of the semiconductor segment 221 in the epitaxial wafer 200 is covered, while the remaining portion of the semiconductor segment 221 is exposed.

[0082] In an exemplary embodiment, the thickness of the insulating protective layer 320 may be 1-4 μm, such as 1 μm, 1.5 μm, 2 μm, 3.5 μm, 4 μm, or other values.

[0083] S150, partially remove the insulating protective layer 320 covering the metal layer 310 and the first semiconductor layer 220 to partially expose the metal layer 310 and the first semiconductor layer 220.

[0084] Specifically, in the embodiments of this application, such as Figure 7 As shown, removing the insulating protective layer 320 partially means removing the insulating protective layer 320 covering the metal layer 310 and removing the insulating protective layer 320 covering the first semiconductor layer 220 located in the opening 262, so as to partially expose the metal layer 310 and the first semiconductor layer 220 located in the opening 262.

[0085] In an exemplary embodiment, the insulating protective layer 320 can be partially removed using a dry etching machine by means of, but not limited to, dry etching. The etching gas used in the dry etching can be CF4 / O2 / Ar, and the etching depth of the insulating protective layer 320 needs to penetrate through it.

[0086] S160, a first electrode 340 and a second electrode 350 are formed at the positions where the metal layer 310 is exposed and the first semiconductor layer 220 is located in the opening 262, respectively. The first electrode 340 is electrically connected to the metal layer 310 and the second electrode 350 is electrically connected to the first semiconductor layer 220 to obtain a plurality of light-emitting chips 300.

[0087] Specifically, in the embodiments of this application, such as Figure 8 As shown, after partially removing the insulating protective layer 320 covering the metal layer 310 and the first semiconductor layer 220 located within the opening 262, the metal layer 310 and the first semiconductor layer 220 are partially exposed by the insulating protective layer 320. A first electrode 340 and a second electrode 350 are then formed at the locations where the metal layer 310 and the first semiconductor layer 220 are exposed within the opening 262, respectively. The first electrode 340 is electrically connected to the metal layer 310, and the second electrode 350 is electrically connected to the first semiconductor layer 220 and exposed within the insulating protective layer 320. For example, the first and second electrodes in this step serve as bonding metal layers, resulting in a complete micro-light-emitting chip 300.

[0088] In an exemplary embodiment, negative photoresist photolithography electrode patterns can be applied to the insulating protective layer 320, and the electrode patterns can be deposited using an evaporation machine. After removing the photoresist through blue film stripping, the first electrode and the second electrode are obtained to prepare multiple light-emitting chips 300. The thickness of the first electrode 340 and the second electrode 350 can be 1-4 μm, for example, 1 μm, 2 μm, 3 μm, 4 μm, or other values.

[0089] S200, fabricate adhesive pillars 400 on the plurality of semiconductor segments 221.

[0090] Please refer to the following for details. Figure 9 In this embodiment, adhesive pillars 400 formed of bonding adhesive are fabricated on a plurality of semiconductor segments 221, wherein the height of the adhesive pillars 400 is greater than the height of the light-emitting chip 300. Since adhesive pillars 400 are fabricated on each semiconductor segment 221, adhesive pillars 400 are disposed on opposite sides of each light-emitting chip 300.

[0091] In this embodiment, the adhesive column 400 may be made of benzocyclobutene (BCB).

[0092] S300, a first temporary substrate 500 is provided, the first temporary substrate 500 is disposed on one end of the adhesive pillar 400 opposite to the semiconductor segment 221.

[0093] Please refer to the following for details. Figure 10 In this embodiment, after fabricating a bonding pillar 400 formed of bonding adhesive on the semiconductor segment 221, a first temporary substrate 500 is provided, and the first temporary substrate 500 is bonded to one end of the bonding pillar 400 facing away from the semiconductor segment 221. Since the height of the bonding pillar 400 is greater than the height of the light-emitting chip 300, a predetermined distance is maintained between the light-emitting chip 300 and the first temporary substrate 500.

[0094] S400, Remove the substrate layer 210 on the epitaxial wafer 200 to form a wafer source 600 including a plurality of light-emitting chips 300.

[0095] Please refer to the following for details. Figure 11In this embodiment, the substrate layer 210 in the epitaxial wafer 200 is removed, for example, by laser lift-off, to form a wafer source 600. The wafer source includes the light-emitting chip 300, the adhesive pillar 400, and the first temporary substrate 500. The wafer source 600 may be a weakened structure, comprising multiple light-emitting chips 300, multiple adhesive pillars 400, and the first temporary substrate 500. The multiple light-emitting chips 300 are connected via the semiconductor segment 221, the multiple adhesive pillars 400 are disposed on the semiconductor segment 221, and the first temporary substrate 500 is disposed on one end of the adhesive pillar 400 facing away from the semiconductor segment 221.

[0096] S500: Remove the connection between the light-emitting chip and the semiconductor segment, and transfer the plurality of light-emitting chips in the wafer source to a backplane, wherein the plurality of light-emitting chips are electrically connected to the backplane. Please refer to [further details omitted]. Figures 12 to 15 As shown, in this embodiment, step S300 includes at least the following steps.

[0097] S510, Grab the chip source 600 and disconnect the plurality of light-emitting chips 300 in the chip source 600 from the semiconductor segment 221.

[0098] Specifically, in the embodiments of this application, such as Figure 13 As shown, the transfer head 700 grasps the chip source 600. During grasping, the transfer head 700 presses the light-emitting chip 300 towards the light-emitting chip 300 so that the semiconductor segment 221 between the light-emitting chip 300 and the adhesive pillar 400 breaks. At this time, the light-emitting chip 300 is no longer held by the semiconductor segment 221.

[0099] S520, a second temporary substrate 510 is provided, and a plurality of light-emitting chips 300 in the wafer source 600 are transferred to the second temporary substrate 510.

[0100] Specifically, in the embodiments of this application, such as Figure 14 As shown, after the semiconductor segment 221 between the light-emitting chip 300 and the adhesive pillar 400 is broken and detached by the transfer head 700, a second temporary substrate 510 is provided, and the transfer head 700 transfers multiple light-emitting chips 300 onto the second temporary substrate 510. In this embodiment, the transfer head 700 may be an elastic mold.

[0101] S530, the plurality of light-emitting chips 300 are transferred from the second temporary substrate 510 to the back plate 800, and the first electrode 340 and the second electrode 350 of the plurality of light-emitting chips 300 are electrically connected to the back plate 800.

[0102] Specifically, in the embodiments of this application, such as Figure 15 As shown, a plurality of light-emitting chips 300 can be transferred from the second temporary substrate 510 to the back plate 800 by, for example, an elastic mold, and the first electrode 340 and the second electrode 350 of the plurality of light-emitting chips 300 are electrically connected to the back plate 800.

[0103] In summary, in the chip transfer method of this application, the semiconductor segment 221 of the light-emitting chip 300 itself serves as a supporting connection layer. The semiconductor segment 221 connects the light-emitting chip 300 to the adhesive pillar 400. By controlling the thickness of the semiconductor segment 221, the connection force between the light-emitting chip 300 and the adhesive pillar 400 is controlled, achieving adjustable connection force. Simultaneously, the transfer head 700 breaks the semiconductor segment 221 to transfer the light-emitting chip 300, solving the problem in the prior art where the light-emitting chip cannot be easily grasped by the elastic mold, thereby increasing the transfer yield of the light-emitting chip 300.

[0104] This application also provides a display panel, which includes a backplate 40 as shown in the above embodiments and a light-emitting chip 300 transferred to the backplate 800 by the light-emitting chip transfer method described in the above embodiments. It is understood that the light-emitting chip 300 may be a red light-emitting chip, a green light-emitting chip, or a blue light-emitting chip. In other embodiments, the display panel may further include a display area and a non-display area, wherein the display area is used for image display, and the non-display area is disposed around the display area and is not used for image display. The display panel may use liquid crystal material as the display medium, but this application is not limited thereto.

[0105] Understandably, the display panel can be used in electronic devices that include functions such as a Personal Digital Assistant (PDA) and / or a music player, such as mobile phones, tablets, and wearable electronic devices with wireless communication capabilities (such as smartwatches). The aforementioned electronic devices can also be other electronic devices, such as laptops with touch-sensitive surfaces (e.g., touch panels). In some embodiments, the electronic device may have communication capabilities, i.e., it can establish communication with a network via 2G (second-generation mobile communication technology), 3G (third-generation mobile communication technology), 4G (fourth-generation mobile communication technology), 5G (fifth-generation mobile communication technology), or W-LAN (wireless local area network) or other communication methods that may emerge in the future. For the sake of simplicity, this application embodiment does not further limit this aspect.

[0106] This application also provides a display device, which includes a support frame and a display panel as described in the above embodiments, wherein the support frame supports the display panel. The display device includes, but is not limited to, any electronic device or component with display function, such as a Mini LED panel, a Micro LED panel, a mobile phone, a tablet computer, a navigator, or a monitor; this application does not impose specific limitations on this. It is understood that the display device may further include: a pixel circuit disposed in the display area within the display panel for displaying images; and a circuit board assembly for providing operating voltage, driving current, and corresponding functional signals.

[0107] It should be understood that the application of this application is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A method for transferring light-emitting chips, characterized in that, The transfer method includes: An epitaxial wafer is provided, and multiple light-emitting chips are obtained from the epitaxial wafer. The light-emitting chips are connected to each other through semiconductor segments. Adhesive pillars are fabricated on a plurality of semiconductor segments on the epitaxial wafer; A first temporary substrate is provided, the first temporary substrate being disposed at one end of the adhesive pillar opposite to the semiconductor segment; Remove the substrate layer on the epitaxial wafer to form a wafer source comprising a plurality of the light-emitting chips; Remove the connection between the light-emitting chip and the semiconductor segment, transfer the plurality of light-emitting chips in the wafer source to the backplane, and electrically connect the plurality of light-emitting chips to the backplane; An epitaxial wafer comprising multiple epitaxial structures is provided, wherein multiple openings are formed on the epitaxial wafer, each opening corresponds to one of the epitaxial structures, and the epitaxial structures are formed into a first region and a second region; Multiple slots are formed on the epitaxial wafer, each slot is disposed between two adjacent epitaxial structures, and the bottom of the slot is located within the first semiconductor layer of the epitaxial wafer to recess the first semiconductor layer to form the semiconductor segment; A metal layer is formed on the second semiconductor layer of the epitaxial wafer located in the first region; An insulating protective layer is formed covering the metal layer and a portion of the epitaxial wafer to partially expose the semiconductor segment; Partially remove the insulating protective layer covering the metal layer and the first semiconductor layer to partially expose the metal layer and the first semiconductor layer; A first electrode and a second electrode are formed at the locations where the metal layer is exposed and the first semiconductor layer is located within the opening, respectively. The first electrode is electrically connected to the metal layer, and the second electrode is electrically connected to the first semiconductor layer, to obtain a plurality of light-emitting chips.

2. The method for transferring a light-emitting chip as described in claim 1, characterized in that, The step of removing the connection between the light-emitting chip and the semiconductor segment, transferring multiple light-emitting chips from the wafer source to a backplane, wherein the multiple light-emitting chips are electrically connected to the backplane, includes: The chip source is captured, and the plurality of light-emitting chips in the chip source are disconnected from the semiconductor segment; A second temporary substrate is provided, and a plurality of light-emitting chips in the wafer source are transferred to the second temporary substrate; The plurality of light-emitting chips are transferred from the second temporary substrate to the back plate, and the first electrode and the second electrode of the plurality of light-emitting chips are electrically connected to the back plate.

3. The method for transferring a light-emitting chip as described in claim 2, characterized in that, The step of grasping the chip source and disconnecting the plurality of light-emitting chips in the chip source from the semiconductor segment includes: The transfer head picks up the wafer source and presses the transfer head toward the light-emitting chip to break the semiconductor segment between the light-emitting chip and the adhesive pillar.

4. The method for transferring a light-emitting chip as described in claim 1, characterized in that, The epitaxial structure includes a substrate layer, a first semiconductor layer, a multi-quantum-well light-emitting layer, and a second semiconductor layer stacked sequentially. Each opening penetrates the second semiconductor layer and the multi-quantum-well light-emitting layer and communicates with the first semiconductor layer. Each slot penetrates the second semiconductor layer and the multi-quantum-well light-emitting layer sequentially and is recessed into the first semiconductor layer. A portion of the first semiconductor layer adjacent to the multi-quantum-well light-emitting layer is etched, and the remaining portion of the first semiconductor layer is not etched to form the semiconductor segment.

5. The method for transferring a light-emitting chip as described in claim 1, characterized in that, Each of the semiconductor segments is provided with adhesive pillars, and adhesive pillars are provided on opposite sides of each light-emitting chip. The height of the adhesive pillars is greater than the height of the light-emitting chip, and the light-emitting chip is spaced apart from the first temporary substrate by a predetermined distance.

6. The method for transferring a light-emitting chip as described in any one of claims 1-4, characterized in that, The thickness of the metal layer is 200-2000 Å, the thickness of the insulating protective layer is 1-4 μm, and the thickness of the first electrode and the second electrode is 1-4 μm.

7. The method for transferring a light-emitting chip as described in any one of claims 1-4, characterized in that, The metal layer is made of indium tin oxide, the adhesive column is made of benzocyclobutene, and the insulating protective layer is a distributed Bragg mirror.

8. A display panel, characterized in that, It includes a backplate and a plurality of light-emitting chips transferred to the backplate by the light-emitting chip transfer method as described in any one of claims 1-7.

9. A display device, characterized in that, It includes a support frame and a display panel as described in claim 8, wherein the support frame is used to support the display panel.

Images