Binding method of light emitting diode and display panel

Abstract

The invention provides a binding method of a light emitting diode and a display panel, and belongs to the technical field of photoelectron manufacturing. The binding method comprises the steps that a to-be-bound product is prepared, the to-be-bound product comprises a first substrate, LED core particles and a filling layer, the LED core particles are located on the surface of the first substrate, the filling layer is located on the surface of the first substrate and covers the LED core particles, and electrodes of the LED core particles are exposed out of the filling layer; and the product to be bound is bound to a driving substrate, so that the electrodes of the LED core particles are fixedly connected with the bonding pads of the driving substrate. According to the invention, the gaps between the LED core particles and the driving substrate can be rapidly filled with the glue material, and the problem that holes and bubbles appear in the glue material layer is avoided.

Description

Technical Field

[0001] The present disclosure relates to the field of optoelectronic manufacturing technologies, and particularly to a bonding method for light-emitting diodes and a display panel. Background Art

[0002] A display panel includes a driving substrate and a plurality of light-emitting diodes. A plurality of pads corresponding to the light-emitting diodes are provided on the surface of the driving substrate. The electrodes of the light-emitting diodes are bonded to the corresponding pads to assemble the display panel. In the field of micro-displays with high PPI requirements, Micro LED display panels are usually adopted. A Micro LED display panel refers to a display device obtained by thermally bonding a specific driving IC (Die-to-Die bonding) using ultra-small micro LED vertical chips (chip size 3 μm to 20 μm). The Micro LED display panel can achieve a resolution of more than 2.5K with a display area of less than 1 inch.

[0003] In related technologies, when thermally bonding a micro LED vertical chip to a driving substrate, bonding metal is usually provided on the surface of the electrode of the light-emitting diode and the pad of the driving substrate, and then alignment heating and bonding welding are performed to fix the pad of the driving substrate and the electrode of the light-emitting diode together. After the light-emitting diode is bonded to the driving substrate, a glue material is filled in the gap between the light-emitting diode and the driving substrate, and after the glue material is cured, the connection strength between the electrode of the light-emitting diode and the pad of the driving substrate is enhanced.

[0004] However, the filled liquid glue material flows into the gap between the light-emitting diode and the driving substrate through capillary action. Since the glue filling action by capillary action is actually very slow, it usually takes more than 3 hours to complete the glue filling by capillary action for a micro-display area of 1 inch, and the larger the display area, the longer the required time. Moreover, during the long glue filling period, the glue material becomes viscous and its fluidity decreases due to time-temperature equivalence. At the same time, this glue filling method is also very likely to have void bubbles. In the subsequent process of laser peeling the substrate of the light-emitting diode, the light-emitting diodes in this area are extremely vulnerable to laser damage because there is no protection of the glue material in this area. Summary of the Invention

[0005] Embodiments of the present disclosure provide a bonding method for light-emitting diodes and a display panel, which can quickly fill the glue material in the gap between the LED die and the driving substrate and avoid the problem of void bubbles in the glue material layer. The technical solutions are as follows:

[0006] An embodiment of the present disclosure provides a bonding method for a light-emitting diode. The bonding method includes: preparing a product to be bonded, where the product to be bonded includes a first substrate, an LED die, and a filling layer. The LED die is located on the surface of the first substrate, the filling layer is located on the surface of the first substrate and covers the LED die, and the filling layer exposes the electrodes of the LED die; bonding the product to be bonded to a driving substrate so that the electrodes of the LED die are fixedly connected to the pads of the driving substrate.

[0007] In another implementation manner of the embodiment of the present disclosure, preparing the product to be bonded includes: providing a wafer, where the wafer includes a second substrate and an LED die located on the surface of the second substrate; forming a first adhesive layer on the surface of a third substrate, bonding the third substrate to the wafer so that the LED die is embedded in the first adhesive layer, and the thickness of the first adhesive layer is greater than or equal to the height of the LED die; laser separating the second substrate and curing the first adhesive layer to expose the surface of the LED die facing away from the electrodes; forming a second adhesive layer on the surface of the first substrate, bonding the first substrate to the LED die so that the second adhesive layer contacts the surface of the LED die facing away from the electrodes; laser separating the third substrate and curing the second adhesive layer to obtain the filling layer.

[0008] In another implementation manner of the embodiment of the present disclosure, after laser separating the third substrate and curing the second adhesive layer, it further includes: etching the filling layer to expose the electrodes of the LED die.

[0009] In another implementation manner of the embodiment of the present disclosure, both the first adhesive layer and the second adhesive layer are photosensitive adhesive layers.

[0010] In another implementation manner of the embodiment of the present disclosure, preparing the product to be bonded includes: preparing the LED die on the surface of the first substrate; forming the filling layer on the surface of the first substrate so that the filling layer covers the LED die; etching the filling layer to expose the electrodes of the LED die.

[0011] In another implementation manner of the embodiment of the present disclosure, forming the filling layer on the surface of the first substrate includes: spin-coating an organic material layer on the surface of the first substrate, and the preparation materials of the organic material layer include at least one of resin, silicone rubber, and polydimethylsiloxane.

[0012] In another implementation manner of the embodiment of the present disclosure, binding the to-be-bound article to the driving substrate includes: forming a first bonding metal layer on the electrode of the LED die, forming a second bonding metal layer on the pad of the driving substrate, one of the first bonding metal layer and the second bonding metal layer is an Au layer, and the other of the first bonding metal layer and the second bonding metal layer is an Sn layer or an In layer; heating and bonding the first bonding metal layer and the second bonding metal layer, and controlling the bonding pressure to be 10 Kg to 30 Kg.

[0013] In another implementation manner of the embodiment of the present disclosure, when the other of the first bonding metal layer and the second bonding metal layer is an Sn layer, the bonding temperature is 270 °C to 310 °C; when the other of the first bonding metal layer and the second bonding metal layer is an In layer, the bonding temperature is 160 °C to 200 °C.

[0014] In another implementation manner of the embodiment of the present disclosure, after binding the to-be-bound article to the driving substrate, it further includes: laser peeling the first substrate and etching the filling layer to expose the surface of the LED die facing away from the electrode.

[0015] The embodiment of the present disclosure provides a display panel, which includes a driving substrate and an LED die, and the LED die is bound to the driving substrate by using the binding method described above.

[0016] The beneficial effects brought by the technical solution provided by the embodiment of the present disclosure at least include:

[0017] In the binding method of the light-emitting diode provided by the embodiment of the present disclosure, a filling layer covering the LED die is formed on the LED die before bonding the to-be-bound article and the driving substrate. This solves the problem in the related art that after first binding the driving substrate and the to-be-bound article, and then filling the gap between the driving substrate and the to-be-bound article with a glue material, voids and bubbles are likely to appear.

[0018] Moreover, after forming the filling layer covering the LED die, when the first substrate is subsequently laser peeled, since the filling layer covers the LED die, the LED die will not be damaged. At the same time, after forming the filling layer, there is no need to use the pouring method to inject the glue material layer into the gap between the driving substrate and the to-be-bound article, so the problem that the glue material adheres to other areas of the driving substrate and is difficult to clean caused by the glue material pouring method can be avoided. Description of the Drawings

[0019] To more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following will briefly introduce the accompanying drawings required for the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present disclosure. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0020] Figure 1 is a flowchart of a bonding method for a light-emitting diode provided by an embodiment of the present disclosure;

[0021] Figure 2 is a flowchart of another bonding method for a light-emitting diode provided by an embodiment of the present disclosure;

[0022] Figure 3 is a preparation state diagram of a product to be bonded provided by an embodiment of the present disclosure;

[0023] Figure 4 is a preparation state diagram of a product to be bonded provided by an embodiment of the present disclosure;

[0024] Figure 5 is a preparation state diagram of a product to be bonded provided by an embodiment of the present disclosure;

[0025] Figure 6 is a preparation state diagram of a product to be bonded provided by an embodiment of the present disclosure;

[0026] Figure 7 is a preparation state diagram of another product to be bonded provided by an embodiment of the present disclosure;

[0027] Figure 8 is a preparation state diagram of a product to be bonded provided by an embodiment of the present disclosure.

[0028] The descriptions of each mark in the figure are as follows:

[0029] 11. First substrate; 12. Second substrate; 13. Third substrate;

[0030] 20. LED die; 21. Electrode;

[0031] 30. Filling layer; 31. First adhesive layer; 32. Second adhesive layer;

[0032] 40. Driving substrate; 41. Pad. Detailed implementation manners

[0033] To make the objectives, technical solutions, and advantages of the present disclosure clearer, the following will further describe the embodiments of the present disclosure in detail with reference to the accompanying drawings.

[0034] Unless otherwise defined, technical terms or scientific terms used herein shall have the ordinary meanings as understood by those of ordinary skill in the art to which this disclosure pertains. The terms "first", "second", "third" and similar terms used in the specification and claims of this patent application of the disclosure do not denote any order, quantity or importance, but are only used to distinguish different components. Similarly, terms such as "a" or "an" do not denote a quantity limitation, but mean that there is at least one. Terms such as "comprising" or "including" mean that the elements or items appearing before "comprising" or "including" cover the elements or items listed after "comprising" or "including" and their equivalents, and do not exclude other elements or items. Terms such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. Terms such as "upper", "lower", "left", "right", "top", "bottom" are only used to indicate relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationships may also change accordingly.

[0035] Figure 1 is a flowchart of a bonding method for a light-emitting diode provided by an embodiment of the disclosure. As Figure 1 shown, the bonding method includes:

[0036] Step 101: Prepare the article to be bonded.

[0037] Among them, the article to be bonded includes a first substrate 11, an LED die 20 and a filling layer 30. The LED die 20 is located on the surface of the first substrate 11. The filling layer 30 is located on the surface of the first substrate 11 and covers the LED die 20. The filling layer 30 exposes the electrode 21 of the LED die 20.

[0038] Step 102: Bond the article to be bonded to the driving substrate 40 so that the electrode 21 of the LED die 20 is fixedly connected to the pad 41 of the driving substrate 40.

[0039] In the bonding method for a light-emitting diode provided by the embodiment of the disclosure, a filling layer 30 covering the LED die 20 is formed on the LED die 20 before bonding the article to be bonded and the driving substrate 40. This solves the problem in the related art that when the driving substrate 40 and the article to be bonded are first bonded and then a glue material is filled in the gap between the driving substrate 40 and the article to be bonded, voids and bubbles are likely to occur.

[0040] Moreover, after forming the filling layer 30 covering the LED die 20 first, when the first substrate 11 is subsequently laser-stripped, since the filling layer 30 covers the LED die 20, the LED die 20 will not be damaged. At the same time, after forming the filling layer 30 first, there is no need to use the pouring method to inject the glue layer into the gap between the driving substrate 40 and the product to be bonded, so the problem that the glue adheres to other areas of the driving substrate 40 and is difficult to clean caused by the glue pouring method can be avoided.

[0041] Figure 2 is a flowchart of another method for bonding a light-emitting diode provided by an embodiment of the present disclosure. As Figure 2 shown, the bonding method includes:

[0042] Step 201: Prepare the product to be bonded.

[0043] In a first implementation manner, the method for preparing the product to be bonded may include the following steps:

[0044] Figure 3 is a preparation state diagram of a product to be bonded provided by an embodiment of the present disclosure. As Figure 3 shown, in the first step, a wafer is provided.

[0045] As Figure 3 shown, the wafer includes a second substrate 12 and LED dies 20 located on the surface of the second substrate 12.

[0046] Exemplarily, the second substrate 12 may be a sapphire substrate, a glass substrate, or a silicon substrate.

[0047] Optionally, the LED die 20 includes an epitaxial layer and an electrode 21 located on the surface of the epitaxial layer.

[0048] Optionally, the epitaxial layer may include a first semiconductor layer, a multi-quantum well layer, and a second semiconductor layer stacked in sequence.

[0049] In an embodiment of the present disclosure, one of the first semiconductor layer and the second semiconductor layer is an n-type layer, and the other of the first semiconductor layer and the second semiconductor layer is a p-type layer.

[0050] Exemplarily, the first semiconductor layer is an n-type layer, and the second semiconductor layer is a p-type layer.

[0051] Optionally, the LED die 20 further includes a transparent conductive layer, and the transparent conductive layer is located on the surface of the second semiconductor layer.

[0052] Wherein, the transparent conductive layer is a film layer for connecting with the electrode 21. In this way, the transparent conductive layer can laterally expand the current injected by the electrode 21, so that the current can be injected into each area of the epitaxial layer, thereby improving the light emission efficiency.

[0053] Exemplarily, the transparent conductive layer may be an indium tin oxide (ITO) layer or an indium zinc oxide (IZO) layer. The indium tin oxide layer or the indium zinc oxide layer has good transmittance and low resistivity, which can allow more light to transmit through the transparent conductive layer, thus ensuring the light output effect; at the same time, due to the low resistivity, it is also convenient for carrier conduction and improves the injection efficiency.

[0054] As an example, the thickness of the transparent conductive layer may be from 1000 Å to 5000 Å. For example, the thickness of the transparent conductive layer is 2000 Å.

[0055] Hereinafter, taking the epitaxial layer as a blue light epitaxial structure as an example, each layer structure will be described exemplarily. In the blue light epitaxial structure, the p-type layer includes a p-type GaN layer.

[0056] Exemplarily, when growing the p-type GaN layer, the growth pressure of the p-type GaN layer may be from 200 Torr to 600 Torr, and the growth temperature of the p-type GaN layer may be from 800 °C to 1000 °C.

[0057] Optionally, the thickness of the p-type GaN layer may be from 0.5 μm to 3 μm.

[0058] Among them, the multiple quantum well layer may include alternately grown InGaN quantum well layers and GaN quantum barrier layers. The third light-emitting layer may include alternately stacked 3 to 8 periods of InGaN quantum well layers and GaN quantum barrier layers.

[0059] Exemplarily, when growing the multiple quantum well layer, the pressure in the MOCVD reaction chamber is controlled at 200 Torr. When growing the InGaN quantum well layer, the reaction chamber temperature is from 760 °C to 780 °C. When growing the GaN quantum barrier layer, the reaction chamber temperature is from 860 °C to 890 °C.

[0060] As an example, in the embodiments of the present disclosure, the multiple quantum well layer includes alternately stacked 5 periods of InGaN quantum well layers and GaN quantum barrier layers.

[0061] Optionally, the thickness of the multiple quantum well layer may be from 150 nm to 200 nm.

[0062] Among them, the n-type layer includes an n-type GaN layer.

[0063] Exemplarily, the growth temperature of the n-type GaN layer may be from 1000 °C to 1100 °C, and the growth pressure of the n-type GaN layer may be from 100 Torr to 300 Torr.

[0064] Optionally, the thickness of the n-type GaN layer may be from 0.5 μm to 3 μm.

[0065] Optionally, the thickness of the epitaxial layer is 2 μm to 10 μm.

[0066] Exemplarily, the thickness of the epitaxial layer is 6 μm.

[0067] Exemplarily, the electrode 21 includes a p-electrode and an n-electrode. Among them, the p-electrode is used to connect to the p-type layer, and the n-electrode is used to connect to the n-type layer.

[0068] The second step is as Figure 3 shown, a first adhesive layer 31 is formed on the surface of the third substrate 13, and the third substrate 13 is bonded to the wafer, so that the LED chip 20 is embedded in the first adhesive layer 31.

[0069] Exemplarily, the first adhesive layer 31 is a photosensitive adhesive layer.

[0070] Among them, the thickness of the first adhesive layer 31 is greater than or equal to the height of the LED chip 20.

[0071] In the above implementation manner, making the thickness of the formed first adhesive layer 31 exceed the height of the LED chip 20 can ensure that when the third substrate 13 is bonded to the LED chip 20, the LED chip 20 can be completely embedded in the first adhesive layer 31, avoiding partial exposure of some areas of the LED chip 20.

[0072] The third step is as Figure 4 shown, the second substrate 12 is separated by laser and the first adhesive layer 31 is cured to expose the surface of the LED chip 20 facing away from the electrode 21.

[0073] Among them, the cured first adhesive layer 31 completely wraps the LED chip 20, and there is also not likely to be a problem of voids and bubbles in the cured first adhesive layer 31.

[0074] The fourth step is as Figure 5 shown, a second adhesive layer 32 is formed on the surface of the first substrate 11, and the first substrate 11 is bonded to the LED chip 20, so that the second adhesive layer 32 contacts the surface of the LED chip 20 facing away from the electrode 21.

[0075] Exemplarily, the second adhesive layer 32 is a photosensitive adhesive layer.

[0076] The fifth step is as Figure 6 shown, the third substrate 13 is separated by laser and the second adhesive layer 32 is cured to obtain the filling layer 30.

[0077] Through the above-mentioned multiple ways of bonding the substrates, a filling layer 30 covering the LED die 20 is formed, and the filling layer 30 fully fills the gaps between the LED dies 20. Instead of using the glue filling and peeling method in the related art, the risk of bubbles or glue filling failure that may exist in the glue filling process after alignment bonding in the related art is solved.

[0078] Moreover, the LED die 20 is always protected by the photosensitive glue layer throughout the entire process, and the LED die 20 will not be damaged during the process of laser separating the substrate, improving the bonding yield.

[0079] The sixth step is to etch the filling layer 30 to expose the electrode 21 of the LED die 20.

[0080] Specifically, it may include: performing oxygen plasma etching on the filling layer 30 to etch away a part of the thickness of the filling layer 30 to expose the electrode 21.

[0081] In the second implementation manner, the method for preparing the article to be bonded may include the following steps:

[0082] Figure 7 It is a preparation state diagram of another article to be bonded provided by an embodiment of the present disclosure. As Figure 7 shown, in the first step, the LED die 20 is prepared on the surface of the first substrate 11.

[0083] As Figure 7 shown, a plurality of LED dies 20 arranged at intervals are prepared on the surface of the first substrate 11.

[0084] Exemplarily, the first substrate 11 may be a sapphire substrate, a glass substrate or a silicon substrate.

[0085] Optionally, the LED die 20 includes an epitaxial layer and an electrode 21 located on the surface of the epitaxial layer.

[0086] Optionally, the epitaxial layer may include a first semiconductor layer, a multi-quantum well layer and a second semiconductor layer stacked in sequence.

[0087] In the embodiment of the present disclosure, one of the first semiconductor layer and the second semiconductor layer is an n-type layer, and the other of the first semiconductor layer and the second semiconductor layer is a p-type layer.

[0088] Exemplarily, the first semiconductor layer is an n-type layer and the second semiconductor layer is a p-type layer.

[0089] The second step is, as Figure 7 shown, to form a filling layer 30 on the surface of the first substrate 11 so that the filling layer 30 covers the LED die 20.

[0090] Specifically, it may include: spin-coating an organic material layer on the surface of the first substrate 11.

[0091] Optionally, the preparation materials of the organic material layer include at least one of resin, silicone rubber, and polydimethylsiloxane.

[0092] Among them, the thickness of the organic material layer can exceed the height of the LED die 20 to ensure that the organic material layer can completely cover the LED die 20.

[0093] Exemplarily, the organic material layer is a resin layer.

[0094] In some other implementation manners, an inorganic layer can also be deposited on the surface of the first substrate 11 as the filling layer 30.

[0095] The third step, as Figure 7 shown, etch the filling layer 30 to expose the electrode 21 of the LED die 20.

[0096] In the embodiments of the present disclosure, the thickness of the filling layer 30 can be accurately controlled through an etching process, so that while the epitaxial layer of the LED die 20 is covered by the filling layer 30, the electrode 21 can be completely exposed.

[0097] In the above implementation manners, since the organic material layer is in the gap of the LED die 20 and has an adhesion or reinforcement effect on the epitaxial layer, therefore, after the LED die 20 is bonded to the driving substrate 40, no additional potting operation is required, and the laser lift-off operation can be directly performed.

[0098] Step 202: Form a first bonding metal layer on the electrode 21 of the LED die 20, and form a second bonding metal layer on the pad 41 of the driving substrate 40.

[0099] Optionally, one of the first bonding metal layer and the second bonding metal layer is an Au layer, and the other of the first bonding metal layer and the second bonding metal layer is an Sn layer or an In layer.

[0100] Exemplarily, the first bonding metal layer is an Au layer, and the second bonding metal layer is an Sn layer.

[0101] Exemplarily, the first bonding metal layer is an Au layer, and the second bonding metal layer is an In layer.

[0102] Optionally, the driving backplane can be a TFT (Thin Film Transistor) substrate. The driving backplane includes a plurality of driving circuits arranged in an array. Each driving circuit on the driving backplane includes at least 2 TFTs for controlling the light emission of the connected light-emitting layer.

[0103] Exemplarily, the driving circuit includes an active layer, a gate insulating layer, a gate layer, an interlayer dielectric layer, and a source-drain layer that are sequentially stacked on a substrate. The light-emitting layer is connected to the source-drain layer of the corresponding driving circuit.

[0104] Among them, the manufacturing material of the TFT of the driving backplane can be various materials such as polysilicon and metal oxide, and the embodiments of the present disclosure do not limit this.

[0105] Step 203: Heat and bond the first bonding metal layer and the second bonding metal layer.

[0106] Among them, the bonding pressure is controlled to be 10 Kg to 30 Kg. Exemplarily, the bonding pressure is 20 Kg.

[0107] In the embodiments of the present disclosure, during the heat bonding process, the temperature will be controlled to exceed the melting point of the bonding metal, so that Sn or In will melt and gradually diffuse into Au to form a stable AuSu or AuIn alloy, thereby fixing the electrode 21 of the LED die 20 to the pad 41 of the driving substrate 40 together.

[0108] Exemplarily, when the other of the first bonding metal layer and the second bonding metal layer is an Sn layer, the bonding temperature is 270 °C to 310 °C.

[0109] Exemplarily, when the other of the first bonding metal layer and the second bonding metal layer is an In layer, the bonding temperature is 160 °C to 200 °C.

[0110] Exemplarily, the time for heat bonding can be 3 min to 8 min.

[0111] Step 204: Laser lift off the first substrate 11 and etch the filling layer 30 to expose the surface of the LED die 20 facing away from the electrode 21.

[0112] As Figure 8 shown, after removing the first substrate 11 by laser lift off, the surface of the LED die 20 bonded to the driving substrate 40 is exposed, that is, the light-emitting surface of the LED die 20 is exposed, thereby obtaining a display panel.

[0113] The embodiments of the present disclosure provide a display panel, as Figure 8 shown, the display panel includes a driving substrate 40 and a plurality of LED dies 20, the plurality of LED dies 20 are arranged at intervals on the driving substrate 40, and the electrode 21 of the LED die 20 is bonded to the pad 41 of the driving substrate 40 together.

[0114] Among them, the LED die 20 is bonded to the driving substrate 40 by the bonding method described above.

[0115] Optionally, the driving backplane may be a TFT substrate. The driving backplane includes a plurality of driving circuits arranged in an array. Each driving circuit on the driving backplane includes at least two TFTs for controlling the light emission of the connected light-emitting layer.

[0116] Exemplarily, the driving circuit includes an active layer, a gate insulating layer, a gate layer, an interlayer dielectric layer, and a source-drain layer stacked in sequence on the substrate. The light-emitting layer is connected to the source-drain layer of the corresponding driving circuit.

[0117] Among them, the manufacturing material of the TFT of the driving backplane may be polysilicon, metal oxide and other materials, which are not limited in the embodiments of the present disclosure.

[0118] The display device may be any product or component with a display function, such as a mobile phone, a tablet computer, a television, a monitor, a laptop computer, a digital photo frame, a navigator, etc.

[0119] The above is not any form of limitation to the present disclosure. Although the present disclosure has been disclosed as above through embodiments, it is not intended to limit the present disclosure. Any person skilled in the art can make some changes or modifications to equivalent embodiments by using the above-disclosed technical content without departing from the technical solution of the present disclosure. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present disclosure without departing from the content of the technical solution of the present disclosure still fall within the scope of the technical solution of the present disclosure.

Claims

1. A light emitting diode binding method, characterized in that: The binding method includes: A product to be bound is prepared, the product to be bound comprising a first substrate (11), an LED core particle (20) and a filling layer (30), wherein the LED core particle (20) is located on the surface of the first substrate (11), the filling layer (30) is located on the surface of the first substrate (11) and covers the LED core particle (20), and the filling layer (30) exposes the electrode (21) of the LED core particle (20); The product to be bound is bound to a driving substrate (40) so that the electrode (21) of the LED core particle (20) is fixedly connected to the soldering pad (41) of the driving substrate (40).

2. The binding method according to claim 1, characterized in that: The preparation of the product to be bound includes: Providing a wafer, the wafer comprising a second substrate (12) and an LED core (20) located on a surface of the second substrate (12); Forming a first glue layer (31) on the surface of a third substrate (13), bonding the third substrate (13) to the wafer, embedding the LED core (20) in the first glue layer (31), and the thickness of the first glue layer (31) being greater than or equal to the height of the LED core (20); Using a laser to separate the second substrate (12) and solidify the first adhesive layer (31) to expose the surface of the LED core particle (20) facing away from the electrode (21); forming a second adhesive layer (32) on the surface of the first substrate (11), bonding the first substrate (11) to the LED core (20), and making the second adhesive layer (32) contact the surface of the LED core (20) facing away from the electrode (21); The third substrate (13) is separated by laser and the second adhesive layer (32) is cured to obtain the filling layer (30).

3. The binding method according to claim 2, characterized in that: After laser separation of the third substrate (13) and solidification of the second adhesive layer (32), the method further comprises: The filling layer (30) is etched so that the filling layer (30) exposes the electrode (21) of the LED core particle (20).

4. The binding method according to claim 2, characterized in that: The first adhesive layer (31) and the second adhesive layer (32) are both photosensitive adhesive layers.

5. The binding method according to claim 1, characterized in that: The preparation of the product to be bound includes: Preparing the LED core particle (20) on the surface of the first substrate (11); forming the filling layer (30) on the surface of the first substrate (11), so that the filling layer (30) covers the LED core particle (20); The filling layer (30) is etched so that the filling layer (30) exposes the electrode (21) of the LED core particle (20).

6. The binding method according to claim 5, characterized in that: Forming the filling layer (30) on the surface of the first substrate (11) comprises: An organic material layer is spin-coated on the surface of the first substrate (11), wherein the preparation material of the organic material layer comprises at least one of resin, silicone rubber and polydimethylsiloxane.

7. The binding method according to any one of claims 1 to 6, characterized in that: Binding the product to be bound to the driving substrate (40) comprises: A first bonding metal layer is formed on the electrode (21) of the LED core particle (20), and a second bonding metal layer is formed on the pad (41) of the driving substrate (40), wherein one of the first bonding metal layer and the second bonding metal layer is an Au layer, and the other of the first bonding metal layer and the second bonding metal layer is a Sn layer or an In layer; The first bonding metal layer and the second bonding metal layer are heated and bonded, and the bonding pressure is controlled to be 10 Kg to 30 Kg.

8. The binding method according to claim 7, characterized in that: When the other of the first bonding metal layer and the second bonding metal layer is a Sn layer, the bonding temperature is 270° C. to 310° C.; When the other of the first bonding metal layer and the second bonding metal layer is an In layer, the bonding temperature is 160° C. to 200° C.

9. The binding method according to any one of claims 1 to 6, characterized in that: After the product to be bound is bound to the driving substrate (40), the method further comprises: The first substrate (11) is peeled off by laser and the filling layer (30) is etched to expose the surface of the LED core particle (20) facing away from the electrode (21).

10. A display panel, characterized in that: The display panel comprises a driving substrate (40) and an LED chip (20), and the LED chip (20) is bound to the driving substrate (40) by using the binding method according to any one of claims 1 to 9.

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