Mini / Micro LED and manufacturing method thereof

Abstract

The present application discloses a Mini / Micro LED and a manufacturing method thereof. The manufacturing method comprises: preparing metal conductive balls; placing the metal conductive balls into insulating glue and stirring to form anisotropic conductive glue; using a steel mesh coating process to print the anisotropic conductive glue on the pads of the substrate; mounting the Mini / Micro LED chip onto the anisotropic conductive glue, and making the pads of the Mini / Micro LED chip correspond one by one to the pads of the substrate, and hot pressing and curing to obtain the Mini / Micro LED. The technology of the present application aims to form a stable connection between the Mini / Micro LED chip and the substrate through anisotropic conductive glue, including forming an electrical connection through the metal conductive balls and forming adhesion through the curing of the insulating glue. In this way, there is no need to use a reflow soldering process, and the curing temperature of the insulating glue will not exceed the junction temperature of the Mini / Micro LED, thereby ensuring the stability and reliability of the manufactured Mini / Micro LED, effectively improving the service life and performance of the product, and meeting display requirements.

Description

Technical Field

[0001] The present application relates to the field of LED display technology, and in particular to a Mini / Micro LED and a manufacturing method thereof. Background Art

[0002] Higher-resolution displays have more pixels. For example, a 4K display has 8,294,400 pixels, and an 8K display has 33,177,600 pixels. Each pixel requires three chips (red, green, and blue). Traditionally, each chip requires soldering the positive and negative electrodes, resulting in tens or even hundreds of millions of chips being soldered.

[0003] Conventional technology typically uses a reflow soldering process for Mini / Micro LED soldering. During reflow soldering, the soldering temperature typically reaches 200°C to 250°C. Because the junction temperature (Tj) of the red, green, and blue (RGB) chips is generally between 125°C and 150°C, prolonged soldering (over 10 seconds) above this temperature will damage the chips and lead to unstable soldering quality. Summary of the Invention

[0004] The main purpose of this application is to provide a Mini / Micro LED and a manufacturing method thereof, aiming to solve the problem in the prior art that the process of using reflow soldering to connect the LED chip to the substrate is prone to unstable welding quality due to excessively high temperature.

[0005] To achieve the above objectives, the present application provides a method for manufacturing Mini / Micro LEDs, which includes:

[0006] preparing metal conductive balls;

[0007] Putting the metal conductive ball into insulating glue and stirring to form anisotropic conductive glue;

[0008] Printing the anisotropic conductive adhesive on the pads of the substrate using a steel mesh coating process;

[0009] Mounting a Mini / Micro LED chip onto the anisotropic conductive adhesive, and making the pads of the Mini / Micro LED chip correspond one-to-one to the pads of the substrate, and hot pressing and curing to obtain a Mini / Micro LED.

[0010] In some embodiments, preparing the metal conductive ball comprises:

[0011] Selecting a conductive metal material, the conductive metal material includes tin, silver, nickel, gold, copper or their alloys;

[0012] The metal conductive balls with a particle size of 10 μm to 20 μm are prepared by physical vapor deposition, chemical vapor deposition, electroplating or ball milling process.

[0013] In some embodiments, placing the metal conductive ball into insulating glue and stirring to form anisotropic conductive glue includes:

[0014] Providing insulating glue; the insulating glue comprises at least one of epoxy resin, silicone and polyimide; the viscosity of the insulating glue is between 120 and 180 Pa·s;

[0015] The metal conductive balls and the insulating glue are added into a stirring container and stirred to uniformly disperse the metal conductive balls in the insulating glue to obtain anisotropic conductive glue; the volume proportion of the metal conductive balls in the anisotropic conductive glue is 10% to 20%.

[0016] In some embodiments, adding the metal conductive balls and the insulating glue into the stirring container further comprises:

[0017] A dispersant is added into the stirring container simultaneously to prevent the metal conductive balls from agglomerating; the dispersant includes polyethylene glycol, sodium lauryl sulfate, sodium hexametaphosphate and sodium oleate.

[0018] In some embodiments, the stirring step further comprises:

[0019] Degassing the anisotropic conductive adhesive obtained after stirring until no obvious bubbles are present in the anisotropic conductive adhesive;

[0020] Test the conductivity and viscosity of anisotropic conductive adhesive to ensure it meets process requirements.

[0021] In some embodiments, the method further includes the storage and activation of anisotropic conductive adhesive that meets the process requirements, including:

[0022] The anisotropic conductive adhesive is sealed and frozen before and after use, and the freezing temperature is -15 to -20°C; and

[0023] The anisotropic conductive adhesive is restored to room temperature before use and then unsealed, and the relative humidity of the use environment is lower than 60%.

[0024] In some embodiments, before printing the anisotropic conductive adhesive on the pads of the substrate using a steel mesh coating process, the method further includes:

[0025] Providing a steel plate, and forming a steel mesh by opening steel mesh holes according to the occupied size of a group of RGB chips on the substrate;

[0026] A nano hydrophobic coating is coated on the steel mesh to obtain a hydrophobic nano steel mesh.

[0027] In some embodiments, mounting the Mini / Micro LED chip onto the anisotropic conductive adhesive so that the pads of the Mini / Micro LED chip correspond one-to-one to the pads of the substrate, and hot pressing and curing to obtain the Mini / Micro LED includes:

[0028] Mounting the Mini / Micro LED chip onto the anisotropic conductive adhesive on the substrate using a patch device;

[0029] The hot pressing curing parameters are set, and the metal conductive ball is brought into contact with the pads on both sides by hot pressing, and the insulating glue is cured to obtain the Mini / Micro LED.

[0030] In some embodiments, after setting the hot pressing curing parameters, hot pressing to make the metal conductive balls contact the pads on both sides, and curing the insulating glue to obtain the Mini / Micro LED, the process further includes:

[0031] The obtained Mini / Micro LED is subjected to performance testing; the performance testing includes electrical performance testing, optical performance testing, and reliability testing.

[0032] The present application also provides a Mini / Micro LED, which is manufactured using the manufacturing method described above.

[0033] The technical solution provided in this application proposes a Mini / Micro LED and a manufacturing method thereof. The Mini / Micro LED manufacturing method includes: preparing metal conductive balls; placing the metal conductive balls into insulating glue and stirring to form anisotropic conductive glue; using a steel mesh coating process to print the anisotropic conductive glue on the pads of the substrate; mounting the Mini / Micro LED chip onto the anisotropic conductive glue, and making the pads of the Mini / Micro LED chip correspond one-to-one to the pads of the substrate, and hot pressing and curing to obtain the Mini / Micro LED. The technology of this application aims to form a stable connection between the Mini / Micro LED chip and the substrate through anisotropic conductive glue, including forming an electrical connection through the metal conductive balls and forming adhesion through the curing of the insulating glue. In this way, there is no need to use a reflow soldering process, and the curing temperature of the insulating glue will not exceed the junction temperature of the Mini / Micro LED, thereby ensuring the stability and reliability of the Mini / Micro LED, effectively improving the service life and performance of the product, and meeting display requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] One or more embodiments are exemplarily illustrated by corresponding drawings, which do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0035] Figure 1 Schematic diagram of the process of manufacturing Mini / Micro LED in an embodiment of the present application;

[0036] Figure 2 Schematic diagram of the preparation process of anisotropic conductive adhesive in an embodiment of the present application;

[0037] Figure 3 This is a partially enlarged view of the Mini / Micro LED in the embodiment of the present application. DETAILED DESCRIPTION

[0038] To facilitate understanding of this application, the following description is provided in more detail with reference to the accompanying drawings and specific embodiments. It should be noted that when an element is described as being "fixed to" another element, it may be directly attached to the other element, or one or more intervening elements may be present. When an element is described as being "connected to" another element, it may be directly connected to the other element, or one or more intervening elements may be present. The terms "vertical," "horizontal," "left," "right," "inner," "outer," and similar expressions used in this specification are for illustrative purposes only. In the description of this application, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating relative importance or implicitly specifying the number of technical features indicated. Therefore, unless otherwise specified, features specified as "first" or "second" may explicitly or implicitly include one or more of such features; "plurality" means two or more. The term "comprising" and any variations thereof are intended to be non-exclusive, and one or more other features, integers, steps, operations, units, components, and / or combinations thereof may be present or added.

[0039] In addition, unless otherwise expressly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, an indirect connection through an intermediate medium, or internal communication between two components. All technical and scientific terms used in this specification have the same meaning as those commonly understood by technicians in the technical field of this application. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not used to limit this application. The term "and / or" used in this specification includes any and all combinations of one or more related listed items.

[0040] In addition, the technical features involved in different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0041] For ease of understanding, the specific process of the embodiment of the present application is described below. Figure 1 The present application provides a method for manufacturing a Mini / MicroLED, which includes:

[0042] Step S10: preparing metal conductive balls.

[0043] The metal conductive balls serve as the conductive medium in the anisotropic conductive adhesive, and are used to achieve electrical connection between the substrate and the Mini / Micro LED chip. The preparation of the metal conductive balls includes:

[0044] Conductive metal materials are selected, including tin, silver, nickel, gold, copper or their alloys; and then physical vapor deposition, chemical vapor deposition, electroplating or ball milling processes are used to prepare metal conductive balls with a particle size of 10μm to 20μm.

[0045] For example, when the metal conductive spheres are made of tin, the preparation process is as follows: A high-purity tin block (99.9% or higher) is heated to above its melting point (232°C) to form liquid tin. The liquid tin is then injected into a high-temperature stable oil phase (such as silicone oil or mineral oil), and a surfactant (such as Span 80) is added to prevent the tin droplets from coalescing. High-speed stirring or shear force from a homogenizer is used to disperse the tin into tiny droplets. The stirring speed (typically several thousand to ten thousand revolutions per minute) and the viscosity of the oil phase are controlled to ensure that the droplet size falls within the target range (10-20 μm). The temperature is then slowly lowered to below the melting point of tin, allowing the droplets to solidify into spherical particles. The oil phase and surfactant are then washed away with an organic solvent (such as acetone), and the tin spheres are collected by centrifugation or filtration.

[0046] Among them, the particle size of the metal conductive balls is controlled within the range of 10μm to 20μm, and the particle size error can be further strictly controlled within ±0.5μm. This can ensure that even when the pad size is small, it can be set between the pad of the substrate and the pad of the Mini / MicroLED chip, avoiding poor contact or short circuit problems caused by particles that are too large or too small, thereby forming a stable electrical connection between the substrate and the Mini / MicroLED chip.

[0047] Furthermore, precise particle size control can be achieved by optimizing the preparation process parameters, such as adjusting the rotating disk speed, vibration frequency, and cooling rate, to ensure uniform particle size, thereby improving conductivity and reliability. Furthermore, the particle size can be measured using a laser particle size analyzer.

[0048] Step S20: placing the metal conductive balls into the insulating glue and stirring to form anisotropic conductive glue.

[0049] This step aims to further prepare anisotropic conductive glue (ACG, full name Anisotropic Conductive Glue) based on the prepared metal conductive balls, that is, it conducts electricity in the Z-axis direction while remaining insulating in the X-axis and Y-axis directions.

[0050] See Figure 2 As shown, the preparation of the anisotropic conductive adhesive may further comprise the following steps;

[0051] Step S201: providing insulating glue.

[0052] The insulating adhesive includes at least one of epoxy resin, silicone, and polyimide. Epoxy resin has excellent bonding strength, firmly securing the metal conductive balls and subsequently mounted Mini / MicroLED chips to the substrate. Silicone has excellent flexibility, effectively relieving thermal stress between the chip and substrate. During Mini / MicroLED operation, thermal stress is generated by temperature fluctuations. The flexibility of silicone prevents damage to the chip or substrate caused by thermal stress. Polyimide has excellent electrical insulation properties, effectively preventing current leakage in unintended directions and ensuring the anisotropic conductivity of the anisotropic conductive adhesive.

[0053] Furthermore, the viscosity of the insulating adhesive should be controlled between 120 and 180 Pa·s. Understandably, if the viscosity is too low, the metal conductive balls will easily settle during stirring, resulting in uneven distribution of the conductive balls in the conductive adhesive and affecting the conductive properties of the anisotropic conductive adhesive. Excessively high viscosity, on the other hand, will make stirring difficult, making it difficult to evenly disperse the metal conductive balls in the insulating adhesive. This will also increase the difficulty of the subsequent coating process, potentially leading to uneven coating or the appearance of bubbles.

[0054] Therefore, by precisely controlling the viscosity, the metal conductive balls are evenly distributed in the insulating glue to form a stable anisotropic conductive adhesive layer, thereby establishing a reliable electrical connection between the Mini / MicroLED chip and the substrate.

[0055] Step S202 , adding metal conductive balls and insulating glue into a stirring container; and stirring to uniformly disperse the metal conductive balls in the insulating glue to obtain anisotropic conductive glue.

[0056] In this step, the volume ratio of the metal conductive balls in the anisotropic conductive adhesive is further controlled to be between 10% and 20%. That is, the density of the metal conductive balls in the anisotropic conductive adhesive is between 10% and 20%. A lower density facilitates the dispersion of the metal conductive balls, thereby preventing horizontal contact between adjacent metal conductive balls due to excessive density, which could ultimately lead to short circuits between adjacent pads.

[0057] The metal conductive spheres can be evenly dispersed by setting up a stirring device and maintaining specific stirring parameters. For example, a mechanical stirrer or a magnetic stirrer can be used. Mechanical stirrers offer strong stirring forces and are suitable for high-viscosity insulating adhesive systems. Magnetic stirrers, on the other hand, offer advantages such as pollution-free and uniform stirring, making them suitable for applications requiring high cleanliness. For metal conductive spheres with a particle size of 10-20 μm and insulating adhesives with a viscosity of 120-180 Pa·s, the stirring speed can be set between 200 and 500 rpm. Prolonged stirring times not only increase production costs but may also cause chemical reactions such as cross-linking in the insulating adhesive, affecting its performance. Typically, the stirring time is controlled within 30-60 minutes. During the stirring process, the insulating adhesive can be heated appropriately (for example, epoxy resin adhesives can be heated to 40-60°C) to reduce its viscosity and improve the dispersion of the metal conductive spheres.

[0058] In some embodiments, adding the metal conductive balls and the insulating glue into the stirring container also includes simultaneously adding a dispersant into the stirring container. The dispersant can be adsorbed on the surface of the metal conductive balls, increase the electrostatic repulsion or spatial steric hindrance between the particles, effectively reduce the agglomeration phenomenon between the metal conductive balls, improve the dispersion uniformity, and ensure stable conductive performance.

[0059] During the stirring process, the dispersant is fully mixed with the insulating glue and the metal conductive balls to form a uniform conductive glue system. The dispersant includes polyethylene glycol, sodium lauryl sulfate, sodium hexametaphosphate and sodium oleate.

[0060] In a further embodiment, the preparation of the anisotropic conductive adhesive further comprises the steps of:

[0061] S203 , performing a degassing treatment on the anisotropic conductive adhesive obtained after stirring until no obvious bubbles are present in the anisotropic conductive adhesive.

[0062] It is understandable that after stirring, a large amount of bubbles may exist in the mixed system, affecting the performance of the anisotropic conductive adhesive. This performance impact can be eliminated through degassing treatment.

[0063] Specifically, a vacuum degassing machine can be used to remove bubbles from the conductive adhesive by reducing the air pressure in the container, causing the bubbles to expand and burst. The degassing process is generally controlled within 10 to 20 minutes to ensure that the anisotropic conductive adhesive is uniform and free of bubbles.

[0064] S204, testing the conductivity and viscosity of the anisotropic conductive adhesive to ensure that it meets the process requirements.

[0065] In this step, the conductivity of the anisotropic conductive adhesive can be tested using equipment such as a four-probe tester, including its vertical and horizontal resistivity. The vertical resistivity should be low to ensure good conductivity, while the horizontal resistivity should be high to prevent short circuits. A rotational viscometer can also be used to measure the viscosity of the anisotropic conductive adhesive. The viscosity should be controlled within an appropriate range to ensure uniform printing on the substrate during the subsequent coating process.

[0066] The technical solution of this application also includes the storage and activation of the anisotropic conductive adhesive that meets the process requirements after the preparation of the conductive adhesive is completed, including:

[0067] The anisotropic conductive adhesive should be sealed and frozen before and after use, and the freezing temperature should be between -15 and -20 degrees Celsius. This storage setting can better balance the storage effect and equipment cost, effectively reduce the chemical reaction rate, slow down the aging process of the anisotropic conductive adhesive, and extend its service life. And,

[0068] Before use, return the anisotropic conductive adhesive to room temperature before removing the seal. This prevents condensation on the adhesive surface, which can cause a rapid drop in adhesive strength. Therefore, when removing the seal, always return the adhesive to room temperature before opening. It is recommended to return the adhesive to room temperature at 25°C for at least 2-4 hours, and no more than three times. Furthermore, anisotropic conductive adhesive is humidity-sensitive and should not be exposed to air for extended periods. The relative humidity in the operating environment should be below 60%.

[0069] Under the above storage and activation conditions, the performance stability of the anisotropic conductive adhesive is guaranteed, and further steps are carried out:

[0070] In step S30 , anisotropic conductive adhesive is printed on the pads of the substrate using a steel mesh coating process.

[0071] In this step, compared to dispensing or photolithography, the use of steel screen printing for single-shot molding is suitable for mass production and improves efficiency. The steel screen process has high precision and miniaturization, which is suitable for the high-density pad layout of this application. A process step for uniformly coating anisotropic conductive adhesive on the pads of the substrate is as follows:

[0072] Using optical positioning, the stencil openings are aligned with the substrate pads. Anisotropic conductive adhesive is evenly applied to the stencil surface. A scraper is applied across the stencil at a constant speed (10-50 mm / s) and pressure (0.1-0.3 MPa), allowing the adhesive to leak through the openings and onto the pads. The stencil is then slowly lifted vertically to avoid stringing or misalignment. The adhesive layer thickness and uniformity are then inspected using a microscope or automated optical inspection (AOI).

[0073] It can be understood that the steel mesh coating process, before printing the anisotropic conductive glue on the pad of the substrate, also includes: providing a steel plate, opening steel mesh holes according to the occupied size of a group of RGB chips on the substrate to form a steel mesh; and coating the steel mesh with a nano-hydrophobic coating to obtain a hydrophobic nano-steel mesh.

[0074] The purpose of creating stencil holes based on the footprint of a set of RGB chips on the substrate is to accommodate the layout requirements of smaller pad sizes (8K or even denser pixel counts). With smaller pad sizes, the stencil holes cannot be precisely defined, and anisotropic conductive adhesive (ACA) is difficult to brush into and contact the pads. Even if brushed into the pads, it can easily be pulled out when the stencil is removed. Therefore, the stencil holes are customized based on the dimensions of the RGB chips (including red, green, and blue LEDs). The stencil holes are relatively large, ensuring smooth filling and contact between the ACA and the pads. Furthermore, a nano-hydrophobic coating is applied to the stencil. The nanomaterial smoothes the stencil hole walls, significantly reducing adhesion between the ACA and the hole walls, thereby improving release properties. During the printing process, the ACA transfers more completely from the stencil holes to the substrate, reducing adhesive residue and fins, thereby improving print quality.

[0075] In step S40 , the Mini / MicroLED chip is mounted on the anisotropic conductive adhesive, and the pads of the Mini / MicroLED chip are aligned one by one with the pads of the substrate, and then hot pressing and curing are performed to obtain the Mini / MicroLED.

[0076] Specifically, this involves using chip placement equipment to attach Mini / MicroLED chips to anisotropic conductive adhesive on a substrate. High-precision chip placement equipment, such as a die bonder, features a high-precision positioning system that precisely places the Mini / MicroLED chips within the anisotropic conductive adhesive on the substrate, ensuring a one-to-one alignment between the substrate pads and the Mini / MicroLED chip pads. Compared to manual placement, this process is several or even dozens of times faster, significantly improving production efficiency and meeting the demands of large-scale production (based on a mass transfer process for high-volume transfer and precise placement).

[0077] Furthermore, hot pressing curing parameters are set to bring the metal conductive balls into contact with the pads on both sides and fully cure the insulating adhesive to form the Mini / MicroLED. For example, the hot pressing temperature is determined based on the curing characteristics of the anisotropic conductive adhesive, generally between 100 and 150°C; the hot pressing pressure is between 20 and 100N; and the hot pressing time is between 5 and 30 minutes. Appropriate hot pressing parameters can ensure that the metal conductive balls form a good electrical connection with the pads of the Mini / MicroLED chip and the pads of the substrate, while fully curing the insulating adhesive and improving the bonding strength between the Mini / MicroLED chip and the substrate. After hot pressing curing is completed, the product is allowed to cool naturally or by forced cooling to fully cure the anisotropic conductive adhesive. The cooling rate should not be too fast, generally controlled at 5 to 10°C per minute, to avoid cracking of the Mini / MicroLED chip or substrate due to thermal stress.

[0078] It is worth noting that the particle size of the metal conductive balls is very small. Therefore, after the Mini / MicroLED chip is printed and mounted through the steel screen, multiple metal conductive balls will be set between the solder pads of the Mini / MicroLED chip and the solder pads of the substrate. However, normal conductive performance can be achieved by only having both sides of one metal conductive ball in contact with the solder pads of the Mini / MicroLED chip and the solder pads of the substrate.

[0079] Furthermore, after the insulating glue is completely cured to obtain the Mini / Micro LED, the following steps are also included:

[0080] The obtained Mini / MicroLED is subjected to performance testing, including appearance testing, electrical performance testing and reliability testing.

[0081] Appearance inspection: Use a microscope or automated optical inspection (AOI) equipment to perform appearance inspection on the mounted Mini / MicroLEDs to check whether the Mini / MicroLED chips are offset, tilted, damaged, etc., and whether the conductive adhesive has defects such as overflow and bubbles.

[0082] Electrical performance testing: The electrical performance of the product is tested using testing equipment, including parameters such as resistance, current, and voltage, to ensure that the electrical connection between the Mini / MicroLED chip and the substrate is good and meets the electrical performance requirements of the product.

[0083] Reliability testing: Reliability tests such as high-temperature and high-humidity tests and thermal shock tests are conducted to simulate the environmental conditions encountered during actual product use and verify product stability and reliability. For example, in a high-temperature and high-humidity test, the product is placed in an environment of 85°C and 85% relative humidity for a specific period of time (e.g., 1000 hours) to observe whether the product exhibits performance degradation, short circuits, or other faults.

[0084] The present application also provides a Mini / Micro LED, which is manufactured using the above manufacturing method.

[0085] like Figure 3 As shown, the present application also discloses a Mini / Micro LED in an embodiment. The Mini / Micro LED includes a substrate 10, an LED chip 20, and an anisotropic conductive adhesive 30. The mounting surface of the substrate 10 is arrayed with a plurality of first pads 11. The Mini / Micro LED chip 20 includes second pads 21 corresponding to the first pads 11. The Mini / Micro LED chip 20 is attached to the mounting surface of the substrate 10. The anisotropic conductive adhesive 30 is disposed between the first and second pads 11, 21. The anisotropic conductive adhesive 30 includes insulating adhesive 31 and metal conductive balls 32 uniformly dispersed within the insulating adhesive 31. The metal conductive balls 32 abut against the first and second pads 11, 21, respectively. Furthermore, the insulating adhesive 31 is filled between the substrate 10 and the Mini / Micro LED chip 20, adhering and securing the substrate 10 and the Mini / Micro LED chip 20.

[0086] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Based on the concept of the present application, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other changes in different aspects of the present application as described above. For the sake of simplicity, they are not provided in detail. Although the present application has been described in detail with reference to the above embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for manufacturing Mini / Micro LED, characterized in that: The manufacturing method comprises: preparing metal conductive balls; Putting the metal conductive ball into insulating glue and stirring to form anisotropic conductive glue; Providing a steel plate, opening steel mesh holes according to the occupied size of a group of RGB chips on the substrate to form a steel mesh, and coating the steel mesh with a nano-hydrophobic coating to obtain a hydrophobic nano-steel mesh; Printing the anisotropic conductive adhesive on the pads of the substrate using a steel mesh coating process; Mounting a Mini / Micro LED chip onto the anisotropic conductive adhesive, aligning the pads of the Mini / Micro LED chip with the pads of the substrate, and performing thermal pressing and curing to obtain a Mini / Micro LED; The step of placing the metal conductive balls into insulating glue and stirring to form anisotropic conductive glue comprises: Providing insulating glue; the insulating glue comprises at least one of epoxy resin, silicone and polyimide; the viscosity of the insulating glue is between 120 and 180 Pa·s; The metal conductive balls and the insulating glue are added to a stirring container, and a dispersant is simultaneously added to the stirring container to prevent the metal conductive balls from agglomerating; the dispersant includes polyethylene glycol, sodium lauryl sulfate, sodium hexametaphosphate and sodium oleate; and the metal conductive balls are stirred to be evenly dispersed in the insulating glue to obtain an anisotropic conductive glue; the volume proportion of the metal conductive balls in the anisotropic conductive glue is 10% to 20%.

2. The manufacturing method according to claim 1, characterized in that The preparation of the metal conductive ball comprises: Selecting a conductive metal material, the conductive metal material includes tin, silver, nickel, gold, copper or their alloys; The metal conductive balls with a particle size of 10 μm to 20 μm are prepared by physical vapor deposition, chemical vapor deposition, electroplating or ball milling process.

3. The manufacturing method according to claim 1, characterized in that After the metal conductive balls are uniformly dispersed in the insulating glue by stirring to obtain anisotropic conductive glue, the method further comprises: Degassing the anisotropic conductive adhesive obtained after stirring until no obvious bubbles are present in the anisotropic conductive adhesive; Test the conductivity and viscosity of anisotropic conductive adhesive to ensure it meets process requirements.

4. The manufacturing method according to any one of claims 1 to 3, characterized in that: It also includes the preservation and activation of anisotropic conductive adhesives that meet process requirements, including: The anisotropic conductive adhesive is sealed and frozen before and after use, and the freezing temperature is -15 to -20°C; and The anisotropic conductive adhesive is restored to room temperature before use and then unsealed, and the relative humidity of the use environment is lower than 60%.

5. The manufacturing method according to claim 1, characterized in that The step of mounting the Mini / Micro LED chip onto the anisotropic conductive adhesive, making the pads of the Mini / Micro LED chip correspond one-to-one to the pads of the substrate, and hot pressing and curing to obtain the Mini / Micro LED comprises: Mounting the Mini / Micro LED chip onto the anisotropic conductive adhesive on the substrate using a patch device; The hot pressing curing parameters are set, and the metal conductive ball is brought into contact with the pads on both sides by hot pressing, and the insulating glue is cured to obtain the Mini / Micro LED.

6. The manufacturing method according to claim 5, characterized in that: After setting the hot pressing curing parameters, hot pressing to make the metal conductive balls contact the pads on both sides, and curing the insulating glue to obtain the Mini / Micro LED, the method further includes: The obtained Mini / Micro LED is subjected to performance testing; the performance testing includes electrical performance testing, optical performance testing, and reliability testing.

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