LED chip structure capable of implementing direct transfer, mass transfer method, and display device and manufacturing method therefor

Abstract

The present application provides an LED chip structure capable of implementing direct transfer, a mass transfer method, and a display device and a manufacturing method therefor. The LED chip structure capable of implementing direct transfer comprises: a substrate and LED chiplets adhered to the substrate by means of an induction layer, wherein the LED chiplets are arranged at intervals, and at least one electrode of each LED chiplet is arranged on the surface of the side of the LED chiplet facing away from the substrate, so that the electrode faces outwards. On the basis of the structure, in an LED chip, outward electrodes of LED chiplets can be selectively aligned with and bonded to a display panel by means of the mass transfer method, i.e., the LED chiplets can be selectively transferred to the display panel, thereby transferring LED chiplets to the display panel from a wafer to form the display panel having pixels, and facilitating production.

Description

A directly transferable LED chip structure, mass transfer method, display device and manufacturing method thereof

[0001] This application claims priority to the Chinese patent application filed with the Patent Office of China on March 26, 2024, with application number CN202420597815.1 and invention name “Directly transferable LED chip structure and display device”, and the Chinese patent application filed with the Patent Office of China on March 26, 2024, with application number CN202410352678.X and invention name “A mass transfer method, display device and manufacturing method thereof”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of light-emitting diodes, and in particular to a directly transferable LED chip structure, a mass transfer method, a display device, and a manufacturing method thereof. Background Art

[0003] Micro-component technology refers to an array of tiny components integrated at high density on a substrate. Currently, micro-pitch light-emitting diode (Micro LED) technology has gradually become a hot research topic, and the industry is looking forward to high-quality micro-component products entering the market. High-quality micro-pitch light-emitting diode products will have a profound impact on traditional display products such as LCD / OLED already on the market. Micro-Led technology, namely LED miniaturization and matrix technology, refers to the technology of integrating high-density, tiny-sized LED arrays on a chip to reduce the distance between pixels from millimeters to microns. Due to the superior performance of Micro-Led, it inherits the advantages of inorganic LEDs such as high brightness, high yield, high reliability, small size and long life, and is increasingly used in the display field.

[0004] During the microcomponent manufacturing process, the microcomponent is first formed on a donor substrate and then transferred to a receiving substrate, such as a display panel. In the production of micro-LEDs, mass transfer is a major bottleneck in their industrialization. Solving this technical challenge is crucial for reducing costs and achieving mass production.

[0005] Even with the emergence of numerous mass transfer technologies, stamp transfer is still the primary method of product development. For flip-chip structures, conventional solutions involve a single bonding process to create a laser-transferable wafer with electrodes facing inward (a freestanding chip on carrier). This requires the removal of residual adhesive from the electrode surface, resulting in a complex process and preventing direct transfer from the chip to the display panel.

[0006] In view of this, the inventors specially designed a directly transferable LED chip structure, a mass transfer method, a display device and a manufacturing method thereof, which resulted in this case.

[0007] Summary of the Invention

[0008] The purpose of this application is to provide a directly transferable LED chip structure, a mass transfer method, a display device and a manufacturing method thereof, so as to obtain a structure and mass transfer that can realize direct chip transfer from the wafer end to the display panel end.

[0009] In order to achieve the above objectives, the technical solutions adopted in this application are as follows:

[0010] A directly transferable LED chip structure, comprising:

[0011] A substrate and LED chips adhered to the substrate via an induction layer, wherein the LED chips are arranged at intervals, and at least one electrode of the LED chips is disposed on a surface of the LED chip facing away from the substrate.

[0012] Preferably, the base plate comprises a transparent substrate.

[0013] Preferably, the induction layer includes any one or more of a thermal induction layer, an ultraviolet light induction layer, a laser induction layer, a radiation induction layer, a plasma induction layer, and a microwave induction layer.

[0014] Preferably, the transparent substrate comprises a transparent inorganic layer.

[0015] Preferably, the transparent substrate includes a glass substrate, a sapphire substrate, or a titanium oxide substrate.

[0016] Preferably, the LED core is a flip-chip structure LED core; wherein, the LED core includes an epitaxial light-emitting layer with a reflector provided on the light-emitting surface, a first electrode and a second electrode, the epitaxial light-emitting layer includes at least a first-type semiconductor layer, an active layer and a second-type semiconductor layer stacked in sequence along a first direction, and the first electrode is in contact with the first-type semiconductor layer by groove embedding, and the second electrode is in contact with the second-type semiconductor layer; the first direction is perpendicular to the substrate and points from the substrate to the LED core.

[0017] Preferably, the LED core is a vertical structure LED core; wherein, the LED core includes an epitaxial light-emitting layer, a first electrode and a second electrode, and the epitaxial light-emitting layer includes at least a first-type semiconductor layer, an active layer, and a second-type semiconductor layer stacked in sequence along a first direction; the second electrode is arranged on a side surface of the second-type semiconductor layer away from the active layer, the first electrode is arranged on a side surface of the first-type semiconductor layer away from the active layer, and the first electrode is embedded in the sensing layer; the first direction is perpendicular to the substrate and points from the substrate to the LED core.

[0018] A display device includes a plurality of pixels arranged on a display panel, wherein the pixels are obtained by selectively aligning and bonding the electrodes of the above-mentioned LED core particles to the display panel.

[0019] Preferably, a bonding pad is provided on the surface of the display panel, and the electrode of the LED chip is bonded to the bonding pad by a reflow soldering process.

[0020] A mass transfer method, comprising the following steps:

[0021] Step S01: providing a light-emitting structure and a first temporary substrate; wherein the light-emitting structure includes a plurality of LED chips spaced apart on the surface of a growth substrate, and a sensing layer is provided on the surface of the first temporary substrate;

[0022] Step S02: bonding the light-emitting structure to the first temporary substrate so that the sensing layer covers the LED core particles;

[0023] Step S03, removing the growth substrate;

[0024] Step S04: providing a second temporary substrate, wherein a sensing layer is provided on a surface of the second temporary substrate;

[0025] Step S05: Align and laminate the second temporary substrate along the side of the first temporary substrate close to the LED core, so that the two substrates are tightly laminated;

[0026] Step S06: Debonding and removing the first temporary substrate using an induction source corresponding to the induction layer, and then removing the induction layer to expose the surfaces of the LED chips;

[0027] Step S07: selectively transferring the LED chips to a display panel.

[0028] Preferably, in step S01 , the thickness of the sensing layer is greater than the height of the LED core.

[0029] Preferably, the first temporary substrate and / or the second temporary substrate comprises a transparent substrate.

[0030] Preferably, the laser sensing layer includes any one or more of acrylic, polyimide, and epoxy resin.

[0031] Preferably, the transparent substrate comprises a transparent inorganic material.

[0032] Preferably, the transparent substrate includes a glass substrate, a sapphire substrate, or a titanium oxide substrate.

[0033] Preferably, the LED chip includes an epitaxial light-emitting layer and an electrode for electrical contact, and in step S01 , the electrode is disposed on a side of the LED chip facing away from the growth substrate.

[0034] Furthermore, in the step S07 , the LED chip is selectively aligned to the bonding pad of the display panel, and the electrode of the LED chip is bonded to the bonding pad through a reflow soldering process.

[0035] Preferably, in the mass transfer method described above, the LED core includes a flip-chip structure LED core; then in the step S01, the LED core includes an epitaxial light-emitting layer with a reflector provided on the light-emitting surface, a first electrode and a second electrode; wherein the epitaxial light-emitting layer at least includes a first-type semiconductor layer, an active layer and a second-type semiconductor layer stacked in sequence along the surface of the growth substrate, and the first electrode forms contact with the first-type semiconductor layer by groove embedding, and the second electrode forms contact with the second-type semiconductor layer; then after the step S07, the induction layer remaining on the surface of the LED core serves as an encapsulation layer.

[0036] Preferably, in the mass transfer method described above, the LED core comprises a vertical structure LED core; then in step S01, the epitaxial light-emitting layer comprises at least a first-type semiconductor layer, an active layer, and a second-type semiconductor layer sequentially stacked along the surface of the growth substrate; and a second electrode is further provided on the surface of the second-type semiconductor layer;

[0037] After the growth substrate is removed in step S03, the method further includes preparing a first electrode on a surface of the LED core particle facing away from the second electrode;

[0038] Accordingly, after step S07 , the first electrodes of the LED chips on the display panel are exposed by removing the sensing layer.

[0039] A method for manufacturing a display device adopts the mass transfer method described above to achieve mass transfer of LED chips from a wafer to a display panel.

[0040] Through the above technical solutions, it can be known that the present application provides a directly transferable LED chip structure and display device, wherein the LED chip structure includes: a substrate and LED core particles adhered to the substrate through an induction layer, wherein the LED core particles are arranged at intervals, and at least one electrode of the LED core particle is provided on the side surface of the LED core particle away from the substrate, so that the electrode faces outward. In this way, the outward-facing electrodes of the LED core particles can be selectively aligned and bonded to the display panel to form a display panel with pixels. Based on the above structure, the LED core particles can be selectively transferred to the display panel, thereby realizing the mass transfer of LED core particles from the wafer to the display panel, which is easy to produce.

[0041] Furthermore, the display panel surface is provided with bonding pads, and the electrodes of the LED chips are bonded to the bonding pads through a reflow soldering process. Thus, the LED chips can be directly transferred to the display panel through the mature and low-cost reflow soldering process.

[0042] In addition, the directly transferable LED chip structure provided by the present application is compatible with flip-chip LED core particles and vertical structure LED core particles, and has extremely high application value.

[0043] The mass transfer method provided by the present invention application is to bond the light-emitting structure and the first temporary substrate so that the sensing material covers each of the LED core particles; then remove the growth substrate, and align and bond the second temporary substrate with the sensing material on the surface along the side of the first temporary substrate close to the LED core particles; then, after debonding and removing the first temporary substrate, the sensing material is removed by a film tearing process to expose the surface of each of the LED core particles, thereby realizing the flipping of the chip and the selective transfer of the LED core particles to the display panel, thereby realizing the transfer of the LED core particles from the wafer to the display panel.

[0044] Furthermore, the LED chip includes an epitaxial light-emitting layer and an electrode for electrical contact. In step S01, the electrode is disposed on the side of the LED chip facing away from the growth substrate. After steps S01 to S06, the chip is flipped so that the electrode faces outward, allowing the LED chip to be selectively transferred directly to a display panel. This simplifies the manufacturing process and facilitates production.

[0045] Furthermore, in step S07, the LED chip is selectively aligned to the bonding pad of the display panel, and the electrodes of the LED chip are bonded to the bonding pad through a reflow soldering process. In this way, the LED chip can be directly transferred to the display panel through the mature and low-cost reflow soldering process.

[0046] In addition, the mass transfer method provided by the present invention is compatible with flip-chip LED core particles and vertical structure LED core particles, and has extremely high application value.

[0047] The present application also provides a display device formed using the above transfer method, which has a simple structure and is easy to operate and implement.

[0048] The present application also provides a method for manufacturing a display device, which is simple to operate and easy to implement while achieving the above-mentioned technical effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without any creative work.

[0050] 1 to 11 are schematic structural diagrams corresponding to the mass transfer method for obtaining the directly transferable LED chip structure and display device provided in Example 1 of the present application;

[0051] 12 to 23 are schematic structural diagrams corresponding to the mass transfer method for obtaining the directly transferable LED chip structure and display device provided in Example 2 of the present application;

[0052] Explanation of symbols in the figure: 1. Growth substrate; 2. LED core particle, 3. First temporary substrate, 4. Sensing layer, 5. Second temporary substrate, 6. Display panel, 7. Bonding pad, 201. Epitaxial light-emitting layer, 202. First electrode, 203. Second electrode. DETAILED DESCRIPTION

[0053] To make the content of this application clearer, the content of this application is further described below with reference to the accompanying drawings. This application is not limited to the specific embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0054] Example 1

[0055] First, this embodiment provides a directly transferable LED chip structure, the LED chip structure comprising:

[0056] A substrate and LED chips adhered to the substrate via an induction layer, wherein the LED chips are arranged at intervals, and at least one electrode of the LED chips is disposed on a surface of the LED chip facing away from the substrate.

[0057] In this embodiment, the substrate includes a transparent substrate.

[0058] In this embodiment, the sensing layer includes any one or more of a thermal sensing layer, an ultraviolet light sensing layer, a laser sensing layer, a radiation sensing layer, a plasma sensing layer, and a microwave sensing layer.

[0059] In this embodiment, the transparent substrate includes a transparent inorganic layer.

[0060] In this embodiment, the transparent substrate includes a glass substrate, a sapphire substrate, or a titanium oxide substrate.

[0061] In this embodiment, the LED core is a flip-chip structure LED core; wherein, the LED core includes an epitaxial light-emitting layer with a reflector provided on the light-emitting surface, a first electrode and a second electrode, and the epitaxial light-emitting layer includes at least a first-type semiconductor layer, an active layer and a second-type semiconductor layer stacked in sequence along a first direction, and the first electrode is in contact with the first-type semiconductor layer by groove embedding, and the second electrode is in contact with the second-type semiconductor layer; the first direction is perpendicular to the substrate and points from the substrate to the LED core.

[0062] Through the above technical solution, it can be known that the directly transferable LED chip structure described in the embodiment of the present application includes: a substrate and LED core particles adhered to the substrate through an induction layer, wherein the LED core particles are arranged at intervals, and at least one electrode of the LED core particle is provided on the side surface of the LED core particle away from the substrate, so that the electrode faces outward. In this way, the outward-facing electrodes of the LED core particles can be selectively aligned and bonded to the display panel to form a display panel with pixels. Based on the above structure, the LED core particles can be selectively transferred to the display panel, thereby realizing the mass transfer of LED core particles from the wafer to the display panel, which is easy to produce.

[0063] An embodiment of the present application further provides a display device, comprising a plurality of pixels arranged on a display panel, wherein the pixels are obtained by selectively aligning and bonding the electrodes of the above-mentioned LED core particles to the display panel.

[0064] Based on the above solution, further, the display panel surface is provided with bonding pads, and the electrodes of the LED chips are bonded to the bonding pads through a reflow soldering process. In this way, the LED chips 2 can be directly transferred to the display panel through the mature and low-cost reflow soldering process.

[0065] In addition, the directly transferable LED chip structure provided by the present application is compatible with flip-chip LED core particles and vertical structure LED core particles, and has extremely high application value.

[0066] Secondly, this embodiment also provides a mass transfer method for obtaining the directly transferable LED chip structure and display device described in this embodiment. The mass transfer method includes the following steps:

[0067] Step S01, providing a light-emitting structure and a first temporary substrate 3; wherein, as shown in FIG2 , the light-emitting structure includes a plurality of LED core particles 2 spaced apart and arranged on the surface of a growth substrate 1; as shown in FIG1 , the surface of the first temporary substrate 3 is provided with a sensing layer 4.

[0068] Based on the above, in this embodiment, the LED chip 2 includes an epitaxial light-emitting layer 201 and an electrode for electrical contact, and the electrode is disposed on a side of the LED chip 2 facing away from the growth substrate 1 .

[0069] Based on the above, in the embodiment of the present application, the LED chip 2 is a flip-chip LED chip. Specifically, as shown in FIG11 , the LED chip 2 includes an epitaxial light-emitting layer 201 having a reflector on its light-emitting surface, a first electrode 202, and a second electrode 203. The epitaxial light-emitting layer 201 includes at least a first-type semiconductor layer, an active layer, and a second-type semiconductor layer sequentially stacked along the surface of the growth substrate 1. The first electrode 202 forms contact with the first-type semiconductor layer by embedding a groove, and the second electrode 203 forms contact with the second-type semiconductor layer. It should be noted that the specific layer types of the first-type semiconductor layer, the active region, and the second-type semiconductor layer are not limited in this embodiment. For example, the first-type semiconductor layer may be, but is not limited to, an N-GaN layer, and correspondingly, the second-type semiconductor layer may be, but is not limited to, a P-GaN layer. Furthermore, the specific locations of the first electrode 202 and the second electrode 203 are also not limited, as long as the first electrode 202 forms an ohmic contact with the first-type semiconductor layer and the second electrode 203 forms an ohmic contact with the second-type semiconductor layer.

[0070] Based on the above content, in one embodiment of the present application, the sensing layer 4 includes any one or more of a thermal sensing layer 4, an ultraviolet light sensing layer 4, a laser sensing layer 4, a radiation sensing layer 4, a plasma sensing layer 4, and a microwave sensing layer 4.

[0071] Preferably, in an embodiment of the present application, the sensing layer 4 is a laser sensing layer 4 with mature technology at this stage; the laser sensing layer 4 includes any one or more of acrylic, polyimide, and epoxy resin.

[0072] Based on the above, in one embodiment of the present application, the first temporary substrate 3 comprises a transparent substrate. Preferably, the transparent substrate comprises a transparent inorganic layer; further, the transparent substrate comprises a glass substrate, a sapphire substrate, or a titanium oxide substrate.

[0073] It is worth mentioning that the type of the growth substrate 1 is not limited in this embodiment. For example, the growth substrate 1 includes any one of sapphire, silicon carbide, silicon, gallium nitride, aluminum nitride, and gallium arsenide. At the same time, as long as the LED core particle 2 meets the above basic requirements, its specific structure and layer composition are not limited in this embodiment.

[0074] Step S02 , as shown in FIG3 , the light emitting structure and the first temporary substrate 3 are bonded together so that the sensing layer 4 covers each of the LED core particles 2 to obtain the structure shown in FIG4 .

[0075] It should be noted that the bonding process is not limited in this embodiment, for example, electrostatic bonding, thermal bonding, etc.

[0076] Step S03: removing the growth substrate 1 to obtain the structure shown in FIG5 .

[0077] Based on the above embodiments, in one embodiment of the present application, removing the growth substrate 1 includes: using a laser lift-off process to remove the growth substrate 1, but the present application is not limited to this. In other embodiments of the present application, other removal processes can also be used to remove the growth substrate 1, depending on the specific circumstances.

[0078] Step S04 , as shown in FIG6 , provides a second temporary substrate 5 , wherein a sensing layer 4 is provided on a surface of the second temporary substrate 5 .

[0079] Based on the above, in one embodiment of the present application, the second temporary substrate 5 comprises a transparent substrate. Preferably, the transparent substrate comprises a transparent inorganic layer; further, the transparent substrate comprises a glass substrate, a sapphire substrate, or a titanium oxide substrate.

[0080] Based on the above content, in one embodiment of the present application, the sensing layer 4 includes any one or more of a thermal sensing layer 4, an ultraviolet light sensing layer 4, a laser sensing layer 4, a radiation sensing layer 4, a plasma sensing layer 4, and a microwave sensing layer 4.

[0081] Preferably, in an embodiment of the present application, the sensing layer 4 is a laser sensing layer 4 with mature technology at this stage; the laser sensing layer 4 includes any one or more of acrylic, polyimide, and epoxy resin.

[0082] Step S05 , as shown in FIG7 , align and laminate the second temporary substrate 5 along the side of the first temporary substrate 3 close to the LED chip 2 , so that the two are tightly laminated.

[0083] Step S06 : After debonding and removing the first temporary substrate 3 by using the induction source corresponding to the induction layer 4 , the induction layer 4 is removed to expose the surface of each LED chip 2 , thereby obtaining the structure shown in FIG. 8 .

[0084] Based on the above content, the sensing layer 4 uses the laser sensing layer 4 which is mature in technology at this stage; in this step, the first temporary substrate 3 can be debonded and removed by laser irradiation; the laser sensing layer 4 can be removed by the film tearing process after debonding, which can ensure the cleanliness of the core particle surface and reduce the process time. The biggest advantage is that there are fewer restrictions on the secondary bonding layer (that is, the sensing layer 4 of the second temporary substrate 5).

[0085] In this way, the directly transferable LED chip structure provided in this embodiment is obtained, as shown in Figure 8, wherein the LED chip structure includes: a substrate (i.e., a second temporary substrate 5) and an LED core particle 2 adhered to the substrate through an induction layer 4, wherein each of the LED core particles 2 is arranged at intervals, and the two electrodes of the LED core particles 2 are arranged on the side surface of the LED core particle 2 facing away from the substrate.

[0086] Step S07 , as shown in FIG. 9 , selectively transfer the aforementioned LED chips 2 to the display panel 6 to form a plurality of pixels arranged on the display panel 6 , thereby obtaining the display device provided by this embodiment.

[0087] In one embodiment of the present application, the LED chip 2 is selectively aligned with the bonding pad 7 of the display panel 6, and a reflow soldering process is performed to bond the electrodes of the LED chip 2 to the bonding pad 7. After step S07, the remaining sensing layer 4 on the surface of the LED chip 2 serves as an encapsulation layer and does not need to be removed.

[0088] Through the above technical solution, it can be known that the mass transfer method provided in the embodiment of the present application is to bond the light-emitting structure and the first temporary substrate 3 so that the sensing layer 4 covers each of the LED core particles 2; then remove the growth substrate 1, and align and bond the second temporary substrate 5 with the sensing layer 4 on the surface along the side of the first temporary substrate 3 close to the LED core particles 2; then, after debonding and removing the first temporary substrate 3, the sensing layer 4 is removed by a film tearing process to expose the surface of each of the LED core particles 2, thereby realizing the flipping of the chip, and the LED core particles 2 can be selectively transferred to the display panel 6, thereby realizing the transfer of the LED core particles 2 from the wafer to the display panel 6.

[0089] Furthermore, the LED chip 2 includes an epitaxial light-emitting layer 201 and an electrode for electrical contact. In step S01, the electrode is disposed on the side of the LED chip 2 facing away from the growth substrate 1. After steps S01 to S06, the chip is flipped so that the electrode faces outward, allowing the LED chip 2 to be selectively transferred directly to the display panel 6. This simplifies the manufacturing process and facilitates production.

[0090] Based on the above solution, further, in step S07, the LED chip 2 is selectively aligned to the bonding pad 7 of the display panel 6, and the electrodes of the LED chip 2 are bonded to the bonding pad 7 through a reflow soldering process. In this way, the LED chip 2 can be directly transferred to the display panel 6 through the mature and low-cost reflow soldering process.

[0091] In this embodiment, bonding pads are provided on the surface of the display panel, and the electrodes of the LED core particles are bonded to the bonding pads through a reflow soldering process. The above display device is formed using the above transfer method, and has a simple structure and is easy to operate and implement.

[0092] The embodiment of the present application also provides a method for manufacturing a display device, which is simple to operate and easy to implement while achieving the above-mentioned technical effects.

[0093] Example 2

[0094] First, this embodiment provides a directly transferable LED chip structure, the LED chip structure comprising:

[0095] A substrate and LED chips adhered to the substrate via an induction layer, wherein the LED chips are arranged at intervals, and at least one electrode of the LED chips is disposed on a surface of the LED chip facing away from the substrate.

[0096] In this embodiment, the substrate includes a transparent substrate.

[0097] In this embodiment, the sensing layer includes any one or more of a thermal sensing layer, an ultraviolet light sensing layer, a laser sensing layer, a radiation sensing layer, a plasma sensing layer, and a microwave sensing layer.

[0098] In this embodiment, the transparent substrate includes a transparent inorganic layer.

[0099] In this embodiment, the transparent substrate includes a glass substrate, a sapphire substrate, or a titanium oxide substrate.

[0100] In this embodiment, the LED core is a vertical structure LED core; wherein, the LED core includes an epitaxial light-emitting layer, a first electrode and a second electrode, and the epitaxial light-emitting layer includes at least a first-type semiconductor layer, an active layer, and a second-type semiconductor layer stacked in sequence along a first direction; the second electrode is arranged on a side surface of the second-type semiconductor layer away from the active layer, the first electrode is arranged on a side surface of the first-type semiconductor layer away from the active layer, and the first electrode is embedded in the sensing layer; the first direction is perpendicular to the substrate and points from the substrate to the LED core.

[0101] Through the above technical solution, it can be known that the directly transferable LED chip structure described in the embodiment of the present application includes: a substrate and LED core particles adhered to the substrate through an induction layer, wherein the LED core particles are arranged at intervals, and at least one electrode of the LED core particle is provided on the side surface of the LED core particle away from the substrate, so that the electrode faces outward. In this way, the outward-facing electrodes of the LED core particles can be selectively aligned and bonded to the display panel to form a display panel with pixels. Based on the above structure, the LED core particles can be selectively transferred to the display panel, thereby realizing the mass transfer of LED core particles from the wafer to the display panel, which is easy to produce.

[0102] An embodiment of the present application further provides a display device, comprising a plurality of pixels arranged on a display panel, wherein the pixels are obtained by selectively aligning and bonding the electrodes of the above-mentioned LED core particles to the display panel.

[0103] Based on the above solution, further, the display panel surface is provided with bonding pads, and the electrodes of the LED chips are bonded to the bonding pads through a reflow soldering process. In this way, the LED chips 2 can be directly transferred to the display panel through the mature and low-cost reflow soldering process.

[0104] In addition, the directly transferable LED chip structure provided by the present application is compatible with flip-chip LED core particles and vertical structure LED core particles, and has extremely high application value.

[0105] Secondly, this embodiment also provides a mass transfer method for obtaining the directly transferable LED chip structure and display device described in this embodiment. The mass transfer method includes the following steps:

[0106] Step S01, providing a light-emitting structure and a first temporary substrate 3; wherein, as shown in FIG13 , the light-emitting structure includes a plurality of LED core particles 2 spaced apart on the surface of a growth substrate 1; as shown in FIG12 , a sensing layer 4 is provided on the surface of the first temporary substrate 3 .

[0107] Based on the above, in this embodiment, the LED chip 2 includes an epitaxial light-emitting layer 201 and an electrode for electrical contact, and the electrode is disposed on a side of the LED chip 2 facing away from the growth substrate 1 .

[0108] Based on the above, in an embodiment of the present application, as shown in FIG23 , the LED core 2 includes a vertically structured LED core 2; the epitaxial light-emitting layer 201 includes at least a first-type semiconductor layer, an active layer, and a second-type semiconductor layer sequentially stacked along the surface of the growth substrate 1; and a second electrode 203 is further provided on the surface of the second-type semiconductor layer. It should be noted that the specific layer types of the first-type semiconductor layer, the active region, and the second-type semiconductor layer are not limited in this embodiment. For example, the first-type semiconductor layer may be, but is not limited to, an N-GaN layer, and correspondingly, the second-type semiconductor layer may be, but is not limited to, a P-GaN layer. Furthermore, the specific location of the second electrode 203 is also not limited, as long as the second electrode 203 forms an ohmic contact with the second-type semiconductor layer.

[0109] Based on the above content, in one embodiment of the present application, the sensing layer 4 includes any one or more of a thermal sensing layer 4, an ultraviolet light sensing layer 4, a laser sensing layer 4, a radiation sensing layer 4, a plasma sensing layer 4, and a microwave sensing layer 4.

[0110] Preferably, in an embodiment of the present application, the sensing layer 4 is a laser sensing layer 4 with mature technology at this stage; the laser sensing layer 4 includes any one or more of acrylic, polyimide, and epoxy resin.

[0111] Based on the above, in one embodiment of the present application, the first temporary substrate 3 comprises a transparent substrate. Preferably, the transparent substrate comprises a transparent inorganic layer; further, the transparent substrate comprises a glass substrate, a sapphire substrate, or a titanium oxide substrate.

[0112] It is worth mentioning that the type of the growth substrate 1 is not limited in this embodiment. For example, the growth substrate 1 includes any one of sapphire, silicon carbide, silicon, gallium nitride, aluminum nitride, and gallium arsenide. At the same time, as long as the LED core particle 2 meets the above basic requirements, its specific structure and layer composition are not limited in this embodiment.

[0113] Step S02 , as shown in FIG. 14 , the light-emitting structure and the first temporary substrate 3 are bonded together, so that the sensing layer 4 covers each of the LED chips 2 , to obtain the structure shown in FIG. 15 .

[0114] It should be noted that the bonding process is not limited in this embodiment, for example, electrostatic bonding, thermal bonding, etc.

[0115] Step S03 , removing the growth substrate 1 to obtain the structure shown in FIG. 16 ; then, preparing the first electrode 202 on the surface of the LED chip 2 facing away from the second electrode 203 .

[0116] Based on the above embodiments, in one embodiment of the present application, removing the growth substrate 1 includes: using a laser lift-off process to remove the growth substrate 1, but the present application is not limited to this. In other embodiments of the present application, other removal processes can also be used to remove the growth substrate 1, depending on the specific circumstances.

[0117] Step S04 , as shown in FIG17 , provides a second temporary substrate 5 , wherein a sensing layer 4 is provided on a surface of the second temporary substrate 5 .

[0118] Based on the above, in one embodiment of the present application, the second temporary substrate 5 comprises a transparent substrate. Preferably, the transparent substrate comprises a transparent inorganic layer; further, the transparent substrate comprises a glass substrate, a sapphire substrate, or a titanium oxide substrate.

[0119] Based on the above content, in one embodiment of the present application, the sensing layer 4 includes any one or more of a thermal sensing layer 4, an ultraviolet light sensing layer 4, a laser sensing layer 4, a radiation sensing layer 4, a plasma sensing layer 4, and a microwave sensing layer 4.

[0120] Preferably, in an embodiment of the present application, the sensing layer 4 is a laser sensing layer 4 with mature technology at this stage; the laser sensing layer 4 includes any one or more of acrylic, polyimide, and epoxy resin.

[0121] Step S05 , as shown in FIG. 18 , align and laminate the second temporary substrate 5 along the side of the first temporary substrate 3 close to the LED chip 2 , so that the two are tightly laminated.

[0122] Step S06 : After debonding and removing the first temporary substrate 3 by using the induction source corresponding to the induction layer 4 , the induction layer 4 is removed to expose the surface of each LED chip 2 , thereby obtaining the structure shown in FIG. 19 .

[0123] Based on the above content, the sensing layer 4 uses the laser sensing layer 4 which is mature in technology at this stage; in this step, the first temporary substrate 3 can be debonded and removed by laser irradiation; the laser sensing layer 4 can be removed by the film tearing process after debonding, which can ensure the cleanliness of the core particle surface and reduce the process time. The biggest advantage is that there are fewer restrictions on the secondary bonding layer (that is, the sensing layer 4 of the second temporary substrate 5).

[0124] In this way, the directly transferable LED chip structure provided in this embodiment is obtained, as shown in Figure 19, the LED chip structure includes: a substrate (i.e., a second temporary substrate 5) and an LED core 2 adhered to the substrate through a sensing layer 4, wherein each of the LED cores 2 is arranged at intervals, and one electrode of the LED core 2 (i.e., the second electrode) is arranged on the side surface of the LED core 2 facing away from the substrate, and the other electrode (i.e., the first electrode) is embedded in the sensing layer.

[0125] Step S07, as shown in FIG. 20 , selectively transfer the aforementioned LED chip 2 to the display panel 6 to obtain the structure shown in FIG. 21 ; then, as shown in FIG. 22 , remove the sensing layer 4 so that the first electrode 202 of the LED chip 2 on the display panel 6 has an exposed surface; thereby forming a plurality of pixels arranged on the display panel 6, thereby obtaining the display device provided in this embodiment.

[0126] Based on the above, in one embodiment of the present application, the second electrode 203 of the LED chip 2 is selectively aligned to the bonding pad 7 of the display panel 6 , and the second electrode 203 of the LED chip 2 is combined with the bonding pad 7 through a reflow soldering process.

[0127] Based on the above content, in one embodiment of the present application, the removal is performed by wet cleaning and / or dry plasma process, which is not limited in the present application.

[0128] The present application also provides a method for manufacturing a display device, which uses the above-mentioned mass transfer method to achieve mass transfer of LED core particles from a wafer to a display panel.

[0129] The present application also provides a display device, which is manufactured using the above-mentioned display device manufacturing method to form the display panel.

[0130] Through the above technical solution, it can be known that the mass transfer method provided in the embodiment of the present application is to bond the light-emitting structure and the first temporary substrate 3 so that the sensing layer 4 covers each of the LED core particles 2; then remove the growth substrate 1, and align and bond the second temporary substrate 5 with the sensing layer 4 on the surface along the side of the first temporary substrate 3 close to the LED core particles 2; then, after debonding and removing the first temporary substrate 3, the sensing layer 4 is removed by a film tearing process to expose the surface of each of the LED core particles 2, thereby realizing the flipping of the chip, and the LED core particles 2 can be selectively transferred to the display panel 6, thereby realizing the transfer of the LED core particles 2 from the wafer to the display panel 6.

[0131] Furthermore, the LED chip 2 includes an epitaxial light-emitting layer 201 and an electrode for electrical contact. In step S01, the electrode is disposed on the side of the LED chip 2 facing away from the growth substrate 1. After steps S01 to S06, the chip is flipped so that the electrode faces outward, allowing the LED chip 2 to be selectively transferred directly to the display panel 6. This simplifies the manufacturing process and facilitates production.

[0132] Based on the above solution, further, in step S07, the LED chip 2 is selectively aligned to the bonding pad 7 of the display panel 6, and the electrodes of the LED chip 2 are bonded to the bonding pad 7 through a reflow soldering process. In this way, the LED chip 2 can be directly transferred to the display panel 6 through the mature and low-cost reflow soldering process.

[0133] In this embodiment, bonding pads are provided on the surface of the display panel, and the electrodes of the LED core particles are bonded to the bonding pads through a reflow soldering process. The above display device is formed using the above transfer method, and has a simple structure and is easy to operate and implement.

[0134] The application also provides a method for manufacturing a display device, which is simple to operate and easy to implement while achieving the above-mentioned technical effects.

[0135] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0136] It should also be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such article or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the article or device comprising the aforementioned elements.

[0137] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present application. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A directly transferable LED chip structure, characterized in that: The LED chip structure includes: A substrate and LED chips adhered to the substrate via an induction layer, wherein the LED chips are arranged at intervals, and at least one electrode of the LED chips is disposed on a surface of the LED chip facing away from the substrate.

2. The directly transferable LED chip structure according to claim 1, wherein: The base plate includes a transparent substrate.

3. The directly transferable LED chip structure according to claim 1, wherein: The induction layer includes any one or more of a thermal induction layer, an ultraviolet light induction layer, a laser induction layer, a radiation induction layer, a plasma induction layer, and a microwave induction layer.

4. The directly transferable LED chip structure according to claim 2, wherein: The transparent substrate includes a transparent inorganic layer.

5. The directly transferable LED chip structure according to claim 4, wherein: The transparent substrate includes a glass substrate, a sapphire substrate, or a titanium oxide substrate.

6. The directly transferable LED chip structure according to any one of claims 1 to 5, characterized in that: The LED core is a flip-chip structure LED core; wherein, the LED core includes an epitaxial light-emitting layer with a reflector provided on the light-emitting surface, a first electrode and a second electrode, the epitaxial light-emitting layer includes at least a first-type semiconductor layer, an active layer and a second-type semiconductor layer stacked in sequence along a first direction, and the first electrode is in contact with the first-type semiconductor layer by groove embedding, and the second electrode is in contact with the second-type semiconductor layer; the first direction is perpendicular to the substrate and points from the substrate to the LED core.

7. The directly transferable LED chip structure according to any one of claims 1 to 5, characterized in that: The LED core is a vertical structure LED core; wherein, the LED core includes an epitaxial light-emitting layer, a first electrode and a second electrode, and the epitaxial light-emitting layer includes at least a first-type semiconductor layer, an active layer, and a second-type semiconductor layer stacked in sequence along a first direction; the second electrode is arranged on a side surface of the second-type semiconductor layer facing away from the active layer, the first electrode is arranged on a side surface of the first-type semiconductor layer facing away from the active layer, and the first electrode is embedded in the sensing layer; the first direction is perpendicular to the substrate and points from the substrate to the LED core.

8. A display device comprising a plurality of pixels arranged on a display panel, characterized in that: The pixel is obtained by selectively aligning and bonding the electrodes of the LED chip according to any one of claims 1 to 7 to the display panel.

9. The display device according to claim 8, wherein The display panel surface is provided with a bonding pad, and the electrode of the LED core particle is bonded to the bonding pad through a reflow soldering process.

10. A mass transfer method, characterized in that: The mass transfer method comprises the following steps: Step S01: providing a light-emitting structure and a first temporary substrate; wherein the light-emitting structure includes a plurality of LED chips spaced apart on the surface of a growth substrate, and the surface of the first temporary substrate is provided with an induction material; Step S02: bonding the light-emitting structure to the first temporary substrate so that the sensing material covers the LED core particles; Step S03, removing the growth substrate; Step S04: providing a second temporary substrate, wherein a sensing material is provided on a surface of the second temporary substrate; Step S05: Align and laminate the second temporary substrate along the side of the first temporary substrate close to the LED core, so that the two substrates are tightly laminated; Step S06: Debonding and removing the first temporary substrate using an induction source corresponding to the induction material, and then removing the induction material to expose the surface of each LED chip; Step S07: selectively transferring the LED chips to a display panel.

11. The method for mass transfer according to claim 10, wherein: The first temporary substrate and / or the second temporary substrate comprises a transparent substrate.

12. The mass transfer method according to claim 10, wherein: The induction material includes any one or more of a thermal induction material, an ultraviolet light induction material, a laser induction material, a radiation induction material, a plasma induction material, and a microwave induction material.

13. The mass transfer method according to claim 11, wherein: The transparent substrate includes a transparent inorganic material.

14. The method for mass transfer according to claim 13, wherein: The transparent substrate includes a glass substrate, a sapphire substrate, or a titanium oxide substrate.

15. The method for mass transfer according to claim 10, wherein: The LED core comprises an epitaxial light-emitting layer and an electrode for electrical contact, and in step S01 , the electrode is disposed on a side of the LED core facing away from the growth substrate.

16. The method for mass transfer according to claim 15, wherein: In the step S07 , the LED chip is selectively aligned to the bonding pad of the display panel, and the electrode of the LED chip is bonded to the bonding pad through a reflow soldering process.

17. The method for mass transfer according to claim 15 or 16, wherein: The LED core comprises a flip-chip structure LED core; in step S01, the LED core comprises an epitaxial light-emitting layer having a reflector on a light-emitting surface, a first electrode, and a second electrode; wherein the epitaxial light-emitting layer comprises at least a first-type semiconductor layer, an active layer, and a second-type semiconductor layer sequentially stacked along the surface of the growth substrate, and the first electrode forms contact with the first-type semiconductor layer by groove embedding, and the second electrode forms contact with the second-type semiconductor layer; after step S07, the inductive material remaining on the surface of the LED core serves as an encapsulation layer.

18. The method for mass transfer according to claim 15 or 16, wherein: The LED core comprises a vertical structure LED core; in step S01, the epitaxial light-emitting layer comprises at least a first-type semiconductor layer, an active layer, and a second-type semiconductor layer sequentially stacked along the surface of the growth substrate; and a second electrode is further provided on the surface of the second-type semiconductor layer; After the growth substrate is removed in step S03, the method further includes preparing a first electrode on a surface of the LED core particle facing away from the second electrode; Accordingly, after step S07 , the first electrodes of the LED chips on the display panel are exposed by removing the sensing material.

19. A method for manufacturing a display device, characterized in that: The mass transfer method according to any one of claims 10 to 18 is used to realize mass transfer of LED core particles from wafers to display panels.

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