Self-adaptive buffering anti-internal shrinkage cob lamp surface steel mesh, preparation and application method thereof

Abstract

The application discloses a self-adaptive buffering anti-shrinkage COB lamp surface steel mesh and a preparation and application method, and belongs to the technical field of COB printing. The lamp surface steel mesh comprises a steel mesh base material and a self-adaptive elastic buffer layer. The self-adaptive elastic buffer layer is in a net structure, and the upper surface of the self-adaptive elastic buffer layer is connected with the lamp surface area of the steel mesh base material. A plurality of micro-nano anti-adhesion openings are arranged on the steel mesh base material and correspond to lamp surface pads. The inner wall of the micro-nano anti-adhesion opening is provided with an array of micro-pits. The application realizes anti-shrinkage from four dimensions of inhibiting deformation of the steel mesh, reducing the adhesion of tin paste, dispersing printing stress and self-adapting to PCB adhesion, and completely solves the tin paste shrinkage problem.

Description

Technical Field

[0001] This invention belongs to the field of COB (Chip on Board) printing technology, specifically involving an adaptive buffer anti-shrinkage COB lamp surface stencil and its supporting preparation and application methods. It is applicable to the solder paste printing process of various COB lamp surface packages such as LED and Micro LED, and is especially suitable for P0.3-P1.0 high-density micro-pitch COB lamp surface package scenarios. Background Technology

[0002] COB (Chip-on-Board) lamp-side packaging is a core process for LED / Micro LED display products. Solder paste printing, as a key process before packaging, directly determines the reliability of the connection between the pads and the chip. However, the shrinkage of solder paste after stencil printing is a core technical bottleneck restricting the development of the industry.

[0003] Solder paste shrinkage manifests as follows: after the solder paste is transferred from the stencil to the PCB lamp surface pads, the solder paste pattern shrinks inward compared to the stencil opening, resulting in irregular edges. This directly leads to insufficient solder paste filling of the pads and poor solder joint formation, which in turn causes problems such as cold solder joints, uneven lamp surface brightness, and chip detachment. In P0.3-P0.6 high-density micro-pitch COB lamp surface packages, this defect has a more prominent impact on product performance, and in severe cases, the package yield is less than 85%.

[0004] Current industry solutions for reducing the size of the steel mesh on lamp faces have significant limitations. They only address the issue from a single perspective and cannot solve the problem at its root. Specific drawbacks are as follows: 1. Structural optimization: Optimization by reducing the inward shrinkage ratio of the stencil opening and increasing the rounded corners of the opening can only alleviate the slight inward shrinkage. It cannot resist the elastic deformation of the stencil caused by printing pressure, nor can it solve the problem of the solder paste pulling and shrinking against the inner wall of the opening during demolding. 2. Coating anti-sticking layer: Fluorine-based and silicon-based nano-coatings are used to improve the release properties of the stencil. Although this can reduce solder paste residue in the short term, the coating is easily worn by scrapers and has poor cleaning resistance. After more than 50,000 uses, the anti-shrinkage effect is drastically reduced. In addition, the coating process increases production costs and cannot solve the core problem of the stencil itself under stress and deformation. 3. Parameter optimization: Reducing shrinkage by lowering squeegee pressure, slowing down printing speed, and adjusting demolding speed will directly lead to a drop in solder paste transfer rate to below 90%, which can easily result in defects such as insufficient solder and exposed copper pads, creating an irreconcilable contradiction between "preventing shrinkage and maintaining solder paste transfer rate". 4. Adaptability: The existing steel mesh structure is fixed. For COB lamp surface packages with different spacing and shape pads, new molds need to be made, resulting in poor versatility and increasing the time and cost of NPI debugging and mass production.

[0005] In summary, existing technologies have not yet formed a multi-dimensional collaborative anti-shrinkage solution that integrates adaptive bonding, stress buffering, anti-sticking demolding, and stress dispersion. This makes it difficult to fundamentally solve the problem of shrinkage in the lamp face steel mesh, which restricts the high-quality development of the COB lamp face packaging industry towards high density, high reliability, and low cost. There is an urgent need for a new steel mesh structure and supporting process to solve the above-mentioned technical problems. Summary of the Invention

[0006] To address the technical problems of existing COB lamp face stencils being prone to shrinkage, the limited range of existing optimization solutions, the inability to balance anti-shrinkage effect with solder paste transfer rate, and poor versatility, this invention provides an adaptive buffer anti-shrinkage COB lamp face stencil and its preparation and application methods.

[0007] This invention achieves anti-stencil shrinkage from four dimensions: "suppressing stencil deformation, reducing solder paste adhesion, dispersing printing stress, and adaptive PCB bonding," through the synergistic design of an adaptive elastic buffer layer, micro-nano anti-adhesion openings, micro-stress dispersion ribs, and stencil substrate. This completely solves the problem of solder paste shrinkage. At the same time, the manufacturing process of this invention is based on improvements to existing equipment, requiring no additional dedicated equipment. It is compatible with COB lamp surface packages with different pitches, balancing high package yield, high solder paste transfer rate, and low cost, and has strong industrialization feasibility.

[0008] This invention is achieved through the following technical solution: An adaptive buffer anti-shrinkage COB lamp face stencil includes a stencil substrate, the upper surface of which is a flat printing area, and the lower surface of which is a lamp face area, with the lamp face area and the flat printing area being vertically opposite each other; it also includes an adaptive elastic buffer layer; the adaptive elastic buffer layer has a mesh structure, the upper surface of which is connected to the lamp face area of ​​the stencil substrate, and the lower surface of which is used to adhere to the lamp face pads; a plurality of micro-nano anti-adhesion openings are provided on the stencil substrate, the micro-nano anti-adhesion openings corresponding to the lamp face pads; the inner wall of the micro-nano anti-adhesion openings is provided with an array of micro-pits.

[0009] Preferably, the micro-nano anti-adhesion opening is circular; the micro-pit diameter is 60-90 nm, the depth is 25-35 nm, and the array spacing is 120-180 nm.

[0010] Preferably, ZnO nanorods are grown on the surface of the micropits.

[0011] Preferably, the ZnO nanorods are 60-70 nm in length and 20-50 nm in diameter, grown by hydrothermal method, and the ZnO nanorods grow perpendicular to the inner wall surface of the micropit, with a coverage of ≥95%.

[0012] Preferably, stress-dispersing ribs are provided on the upper surface of the steel mesh substrate, and in the portion outside the micro-nano anti-adhesion openings. The stress-dispersing ribs are arranged in a mesh pattern around the flat printing area and in the gaps between the micro-nano anti-adhesion openings.

[0013] Preferably, the adaptive elastic buffer layer is made of stainless steel wire mesh woven and compressed and shaped.

[0014] Preferably, the upper surface of the adaptive elastic buffer layer is bonded to the lamp surface area of ​​the steel mesh substrate using a high-temperature resistant adhesive.

[0015] A method for preparing an adaptive buffer anti-shrinkage COB lamp face steel mesh includes the following steps: Step 1: Using laser etching technology, micro-stress-dispersing ribs are processed on the front side of the steel mesh substrate; Step 2: Adhere and bond the adaptive elastic buffer layer to the lamp surface area on the back of the steel mesh substrate, and then cure it. Step 3: Using femtosecond laser interferometry, micro-nano anti-adhesion openings and micro-pits are processed in the lamp surface printing area of ​​the stencil substrate; Step 4: ZnO nanorods are grown on the surface of the micro-pits using a hydrothermal method.

[0016] Preferably, the steel mesh substrate undergoes pretreatment operations such as cutting, grinding, ultrasonic cleaning, and drying before use.

[0017] An application method for an adaptive buffer anti-shrinkage COB lamp face steel mesh includes the following steps: Step 1: Install the stencil substrate with the adaptive elastic buffer layer onto the printing machine, with the flat printing area facing upwards. Adjust the positioning accuracy to ensure that the micro-nano anti-adhesion openings in the lamp surface area are precisely aligned and bonded to the PCB lamp surface pads. Step 2: Start the printer to print solder paste.

[0018] This invention overcomes the limitations of existing technologies that focus on single-dimensional optimization, fundamentally solving the problem of shrinkage in the COB lamp surface steel mesh. Compared with existing technologies, it has the following beneficial effects: 1. Thorough anti-shrinkage effect and significantly improved printing consistency: Through the elastic buffer layer to disperse pressure, stress dispersion ribs to suppress deformation, and micro-nano anti-adhesion openings to reduce adhesion, the three factors work together to reduce the shrinkage rate of the solder paste on the lamp face stencil from more than 5% in the existing technology to less than 0.2%, completely eliminating solder paste shrinkage and edge collapse defects, and improving printing consistency by more than 30%. 2. Balancing high solder paste transfer rate and anti-stick durability: Micro-nano anti-stick openings (ZnO nanorods and micro-pit structures) replace traditional easily worn coatings, with an opening surface energy ≤17mN / m, increasing the solder paste transfer rate to over 99%; at the same time, the stencil has a wear resistance of ≥80,000 cycles, excellent cleaning resistance, and a service life extended by over 40%, fundamentally solving the pain point of rapid decay of the anti-shrinkage effect of traditional coatings; 3. Strong adaptability and high versatility: The elastic buffer layer can adapt to the slight unevenness of the PCB lamp surface without the need for additional adjustment of the printing press bonding parameters; it is compatible with COB lamp surface packages with various pitches from P0.3 to P1.0, and is suitable for NPI debugging and mass production in multiple scenarios such as automotive and outdoor large screens. Multiple products can be adapted simply by optimizing the opening shape / size, which greatly improves the stencil reuse rate. 4. Low industrialization cost and easy implementation: The preparation process is based on the improvement of existing steel mesh processing equipment, without the need for new special equipment; the cost of raw materials such as 304 stainless steel, ZnO, and organosilicon binder is controllable; compared with traditional steel mesh, this invention reduces the overall cost of COB lamp surface encapsulation by more than 20%, which is convenient for large-scale industrialization. 5. Additional protection and yield improvement: The adaptive elastic buffer layer reduces hard contact between the stencil and the PCB lamp surface, avoiding wear on the lamp surface circuit and pads; the micro stress-dispersing ribs can effectively prevent solder paste from accumulating in the opening gap, reducing bridging defects, and improving the yield of COB lamp surface packaging to over 99.5%, further enhancing product reliability. 6. Strong process stability and high product consistency: The parameters of each stage of preparation and application are set within a precise and controllable range, and quality inspection nodes are set throughout the process to ensure the consistency of products in mass production and solve the problem of large fluctuations in product yield in existing technologies. Detailed Implementation

[0019] To make the technical problem to be solved, the technical solution, and the beneficial effects of the present invention clearer, the present invention will be further described in detail with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. The technical solution of the present invention will be described in detail below with reference to embodiments, but the scope of protection is not limited thereto. Example 1

[0020] This embodiment proposes an adaptive buffer anti-shrinkage COB lamp face steel mesh, which includes a steel mesh substrate and an adaptive elastic buffer layer; the steel mesh substrate is made of 304 stainless steel, with a thickness of 0.11mm, a tensile strength of 550MPa, and an elongation of 18%; the upper surface (front) of the steel mesh substrate is a flat printing area, and the lower surface (back) of the steel mesh substrate is the lamp face area, with the lamp face area and the flat printing area being vertically opposite each other; The adaptive elastic buffer layer is disposed on the lamp surface area on the back of the steel mesh substrate. Specifically, the adaptive elastic buffer layer is made of 304 stainless steel wire mesh with a wire diameter of 0.03 mm, a weaving density of 90 mesh, a thickness of 0.04 mm, and a compression resilience of 96%. The upper surface of the adaptive elastic buffer layer is bonded to the lamp surface area of ​​the steel mesh substrate with a high-temperature resistant adhesive, and the bonding force between the layer and the steel mesh substrate is 40 N / cm. 2 The lower surface of the adaptive elastic buffer layer is used to bond with the lamp surface pads. This buffer layer can adapt to the slight unevenness of the PCB lamp surface, evenly distribute the squeegee pressure during printing, avoid localized stress concentration that could cause the stencil to deform and shrink, and at the same time reduce hard contact wear between the stencil and the PCB, protecting the lamp surface circuitry.

[0021] Several micro / nano anti-adhesion openings are formed on the stencil substrate, corresponding to the lamp surface pads. The micro / nano anti-adhesion openings are circular with a diameter of 0.6 mm (consistent with the pads) and rounded edges R0.035 mm. The inner walls of the micro / nano anti-adhesion openings are provided with an array of micropits, each with a diameter of 80 nm, a depth of 30 nm, and a spacing of 150 nm. A layer of ZnO nanorods is grown on the inner surface of the micropits, perpendicular to the inner wall surface of the micropits. The ZnO nanorods are 65 nm long, 35 nm in diameter, have a coverage of 98%, and a surface energy of 16 mN / m. The ZnO nanorods are grown on the surface of the micropits via a hydrothermal method, forming a micro / nano binary rough structure. This reduces the surface energy of the inner wall of the opening to ≤17 mN / m without the need for traditional fluorine-based / silicon-based coatings, significantly reducing the adhesion between the solder paste and the inner wall of the opening, preventing the solder paste from being pulled and shrinking during demolding, and improving the solder paste transfer rate.

[0022] Stress-dispersing ribs are provided on the upper surface of the stencil substrate, excluding the micro-nano anti-adhesion openings. These ribs are arranged in a mesh pattern around the flat printing area and within the gaps of the micro-nano anti-adhesion openings, and are integrally formed with the substrate. The ribs are 0.06 mm wide and 0.025 mm high. These stress-dispersing ribs further disperse localized stress during printing, preventing elastic deformation of the stencil in the lamp area due to stress concentration, and also avoiding solder paste accumulation in the opening gaps, thus reducing bridging defects. Example 2

[0023] This embodiment proposes a method for fabricating an adaptive buffer anti-shrinkage COB lamp surface stencil, used for high-density COB lamp surface encapsulation of P0.6 Micro LEDs; the structure of the lamp surface stencil is the same as in Embodiment 1; the fabrication method includes the following steps: Step 1: Substrate pretreatment: Select 304 stainless steel sheet, cut, grind, ultrasonically clean, and dry to remove surface oil, oxide layer and impurities, and obtain a flat steel mesh substrate; Among them, ultrasonic cleaning is to clean with anhydrous ethanol and deionized water in sequence, each time for 15 minutes; the drying temperature is 90 ℃ and the drying time is 30 minutes. Step 2, Stress-dispersing rib preparation: Using laser etching technology, micro-stress-dispersing ribs are processed on the front side of the steel mesh substrate. The laser power is controlled at 6W and the etching speed is 12 mm / s. After forming, the edges of the ribs are micro-arc polished to remove burrs and ensure that the ribs are flat and do not affect the sliding of the scraper. Step 3: Adaptive Elastic Buffer Layer Bonding: Cut the 304 stainless steel wire mesh to match the size of the lamp face printing area, uniformly coat its surface with a high-temperature resistant adhesive, the adhesive coating thickness is 7μm, and bond it to the lamp face area on the back of the steel mesh substrate. Place it in an oven to cure at 130 ℃ for 40 min. After cooling, check the bonding firmness to ensure that there is no lifting or falling off. In this embodiment, the high-temperature resistant adhesive used is an epoxy resin: Henkel LOCTITE Eccobond series: Eccobond 2850 / 3021.

[0024] Step 4, Micro-nano Anti-adhesion Opening Processing: Using femtosecond laser interferometry, openings are processed in the lamp surface printing area of ​​the stencil substrate. The femtosecond laser power is 4.0W, the pulse frequency is 130kHz, and the pulse width is 200fs. First, the opening outline matching the pad is etched, and then the laser parameters are adjusted: power 3W, pulse frequency 100kHz, to process an array of micro-pits on the inner wall of the opening. Subsequently, a hydrothermal method was used to react the steel mesh in a mixed aqueous solution of zinc nitrate and hexamethylenetetramine (molar ratio of zinc nitrate to hexamethylenetetramine was 1:1). The hydrothermal reaction temperature was 95℃, the reaction time was 2.5h, the zinc nitrate concentration was 0.07mol / L, and the stirring speed was 65r / min. ZnO nanorods were grown on the surface of the micropits by hydrothermal method. After the reaction was completed, the nano- and non-adhesive openings were formed by washing with water and drying. Step 5, Finished Product Inspection: Conduct comprehensive inspections on the thickness of the steel mesh, the resilience of the buffer layer, the opening size, the micro-nano texture parameters, the surface energy, and the size of the stress dispersion ribs. After passing the inspection, perform passivation treatment and encapsulation for later use. Example 3

[0025] This embodiment proposes an application method for an adaptive buffered anti-shrinkage COB lamp face stencil, using the lamp face stencil prepared in Example 2. The lamp face stencil is adaptable to COB lamp face packages with different pitches from P0.3 to P1.0, balancing anti-shrinkage effect and solder paste transfer rate. The specific steps are as follows: Step 1, Stencil Installation and Positioning: Install the prepared lamp face stencil onto the printing press, adjust the positioning accuracy to ensure that the micro-nano anti-adhesion openings in the lamp face area are precisely aligned with the PCB lamp face pads, with an alignment error ≤0.01 mm; during installation, ensure that the adaptive elastic buffer layer gently adheres to the PCB lamp face without compression or deformation; Step 2, Solder paste adaptation: Select COB lamp surface-specific solder paste with a viscosity of 130 Pa·s, and control the printing environment temperature at 23±2 ℃ and humidity at 50%RH to avoid abnormal solder paste viscosity affecting the demolding effect and transfer rate; Step 3, Printing Parameter Settings: Optimize printing parameters: squeegee pressure 0.3 MPa, printing speed 45 mm / s, demolding speed 1.8 mm / s, adopt "slow start and slow stop" demolding mode to reduce stress tension at the moment of demolding; the squeegee and the steel mesh surface contact angle is 48° to ensure smooth squeegee sliding and not damage the micro stress dispersion ribs; Step 4, Printing and Inspection: Start the printer to print solder paste. After printing, use the SPI device to check the integrity of the solder paste pattern and whether there is any shrinkage. At the same time, check the amount of solder paste and the transfer rate. If there are no defects such as shrinkage, insufficient solder, or bridging, proceed to the subsequent die bonding and reflow soldering processes. If a slight abnormality occurs, the demolding speed can be finely adjusted without adjusting the opening size.

[0026] Tests showed that the solder paste shrinkage rate was 0.15%, the solder paste transfer rate was 99.6%, the printing consistency was 98.8%, the encapsulation yield was 99.7%, and the stencil showed no deformation and no decrease in anti-sticking effect after 80,000 printing cycles. Example 4

[0027] This embodiment proposes an adaptive buffer anti-shrinkage COB lamp surface steel mesh, suitable for P0.93 conventional outdoor large screen COB lamp surface encapsulation. The structure is the same as that in Embodiment 1, the difference lies in the specific parameters: 1. Core parameters of steel mesh Steel mesh substrate: 304 stainless steel, thickness 0.14mm, tensile strength 540MPa, elongation 17%; Adaptive elastic buffer layer: 304 stainless steel wire mesh, wire diameter 0.04mm, weave density 85 mesh, thickness 0.05mm, compression resilience 95%, bonding strength with substrate 39N / cm. 2 ; Micro / nano anti-adhesion opening: square opening, side length 0.9mm (consistent with the pad), edge chamfer R0.04mm; inner wall micropit diameter 90nm, depth 35nm, spacing 180nm; ZnO nanorod length 70nm, diameter 50nm, coverage 96%, surface energy 17mN / m; Miniature stress-dispersing ribs: ribs are 0.07mm wide and 0.03mm high, and are arranged in a mesh pattern around the printing area. Example 5

[0028] This embodiment proposes a method for preparing the adaptive buffer anti-shrinkage COB lamp face steel mesh as described in Embodiment 4. The preparation method is the same as that in Embodiment 2, except for the preparation process parameters, specifically: The femtosecond laser power was 4.5W, the pulse frequency was 140kHz, and the pulse width was 300fs; the hydrothermal reaction temperature was 97℃, the reaction time was 2.8h, the zinc nitrate concentration was 0.1mol / L, and the stirring speed was 80r / min; the buffer layer curing temperature was 135℃, and the adhesive coating thickness was 8μm. Example 6

[0029] This embodiment proposes an application method for an adaptive buffer anti-shrinkage COB lamp face steel mesh, using the lamp face steel mesh prepared in Example 5; the application method is the same as in Example 3, except for the application process parameters: COB-specific solder paste with a viscosity of 150 Pa·s was selected; the ambient temperature was 24℃ and the humidity was 60% RH; the squeegee pressure was 0.4 MPa, the printing speed was 50 mm / s, the demolding speed was 2.0 mm / s, the squeegee contact angle was 50°, and the alignment error was 0.009 mm.

[0030] Tests showed that the solder paste shrinkage rate was 0.18%, the solder paste transfer rate was 99.3%, the printing consistency was 98.5%, the encapsulation yield was 99.6%, and the stencil showed no deformation and no decrease in anti-sticking effect after 80,000 printing cycles.

[0031] It should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0032] The detailed descriptions listed above are merely specific descriptions of feasible implementation methods of this application and are not intended to limit the scope of protection of this application. All equivalent implementation methods or modifications made without departing from the spirit of the art of this application should be included within the scope of protection of this invention.

Claims

1. An adaptive buffer anti-shrinkage COB lamp surface stencil, comprising a stencil substrate, wherein the upper surface of the stencil substrate is a flat printing area, and the lower surface of the stencil substrate is a lamp surface area, the lamp surface area and the flat printing area being vertically opposite each other; characterized in that, It also includes an adaptive elastic buffer layer; the adaptive elastic buffer layer has a mesh structure, the upper surface of which is connected to the lamp surface area of ​​the steel mesh substrate, and the lower surface of which is used to adhere to the lamp surface pads; a number of micro-nano anti-adhesion openings are provided on the steel mesh substrate, and the micro-nano anti-adhesion openings correspond to the lamp surface pads; the inner wall of the micro-nano anti-adhesion openings is provided with an array of micro pits.

2. The adaptive buffer anti-shrinkage COB lamp face steel mesh according to claim 1, characterized in that, The micro-nano anti-adhesion openings are circular; the micro-pits have a diameter of 60-90 nm, a depth of 25-35 nm, and an array spacing of 120-180 nm.

3. The adaptive buffer anti-shrinkage COB lamp face steel mesh according to claim 1, characterized in that, ZnO nanorods are grown on the surface of the micropits.

4. The adaptive buffer anti-shrinkage COB lamp face steel mesh according to claim 3, characterized in that, The ZnO nanorods are 60-70 nm in length and 20-50 nm in diameter, and are grown by hydrothermal method. The ZnO nanorods grow perpendicular to the inner wall surface of the micropit, with a coverage of ≥95%.

5. The adaptive buffer anti-shrinkage COB lamp face steel mesh according to claim 4, characterized in that, Stress-dispersing ribs are provided on the upper surface of the steel mesh substrate, and in the portion outside the micro-nano anti-adhesion openings. The stress-dispersing ribs are arranged in a mesh pattern around the flat printing area and in the gaps between the micro-nano anti-adhesion openings.

6. The adaptive buffer anti-shrinkage COB lamp face steel mesh according to claim 1, characterized in that, The adaptive elastic buffer layer is made of stainless steel wire mesh woven and compressed and shaped.

7. The adaptive buffer anti-shrinkage COB lamp face steel mesh according to claim 1, characterized in that, The upper surface of the adaptive elastic buffer layer is bonded to the lamp surface area of ​​the steel mesh substrate with a high-temperature resistant adhesive.

8. The method for preparing an adaptive buffer anti-shrinkage COB lamp face steel mesh according to claim 5, characterized in that, Includes the following steps: Step 1: Using laser etching technology, micro-stress-dispersing ribs are processed on the front side of the steel mesh substrate; Step 2: Adhere and bond the adaptive elastic buffer layer to the lamp surface area on the back of the steel mesh substrate, and then cure it. Step 3: Using femtosecond laser interferometry, micro-nano anti-adhesion openings and micro-pits are processed in the lamp surface printing area of ​​the stencil substrate; Step 4: ZnO nanorods are grown on the surface of the micro-pits using a hydrothermal method.

9. The method for preparing an adaptive buffer anti-shrinkage COB lamp face steel mesh according to claim 8, characterized in that, Before use, the steel mesh substrate undergoes pretreatment processes such as cutting, grinding, ultrasonic cleaning, and drying.

10. The application method of the adaptive buffer anti-shrinkage COB lamp surface steel mesh according to claim 5, characterized in that, Includes the following steps: Step 1: Install the stencil substrate with the adaptive elastic buffer layer onto the printing machine, with the flat printing area facing upwards. Adjust the positioning accuracy to ensure that the micro-nano anti-adhesion openings in the lamp surface area are precisely aligned and bonded to the PCB lamp surface pads. Step 2: Start the printer to print solder paste.