Special conductive silver paste for glass-based circuit board and preparation method thereof

Abstract

The invention provides conductive silver paste special for a glass-based circuit board and a preparation method of the conductive silver paste. The conductive silver paste comprises, by weight, 60-90 parts of silver powder, 4-30 parts of polymer resin, 1.5-5 parts of inorganic filler, 0.05-0.5 part of auxiliaries and 5-20 parts of solvent. The silver powder is spherical and nano silver powder; the glass powder is lead-free glass powder, and the inorganic additive filler is glass powder, indium-tin alloy powder and an expansion coefficient adjusting material (nickel sulfide); the special conductive silver paste for the glass-based circuit board, provided by the invention, has the characteristics of easiness in printing, good solderability by using a lead-free solder after sintering, long service life of a finished product, high and low temperature climate resistance, acid, alkali and salt chemical corrosion resistance, and firm adhesion with a glass substrate without falling after long-term use.

Description

Technical Field

[0001] This invention relates to the technical field of conductive silver paste for glass-based circuit boards and its preparation method, specifically to the field of electrode technology (conductive silver paste) for optoelectronic architectural glass. Background Technology

[0002] With the trend of integrating building intelligence and green energy, optoelectronic smart building glass, with its advantages of energy saving, lighting, and multi-functional integration, has been widely used in core scenarios such as urban lighting projects, glass curtain walls, high-speed rail and subway hubs, and airports and ports, becoming a key component of modern building materials. Conductive silver paste, as the core electrode material of optoelectronic smart building glass, directly determines the glass's conductivity stability, service life, and safety reliability. However, the current market lacks dedicated conductive silver paste developed specifically for the characteristics of glass-based circuit boards; most products use ordinary electronic-grade conductive silver paste or simply modified automotive glass silver paste, which is difficult to adapt to the special application requirements of optoelectronic building glass.

[0003] Existing silver pastes suffer from several technical challenges: First, they have poor adaptability to large-format printing. Photovoltaic architectural glass often requires large-area, high-precision circuit printing, and ordinary silver pastes have a narrow viscosity control range, easily leading to problems such as sagging, dry screens, clumping, or sedimentation, resulting in uneven printed circuits and frequent breakages. Second, there is a mismatch in sintering temperature zones. Different types of glass substrates (such as tempered glass and laminated glass) have significantly different heat resistance thresholds. Traditional silver pastes have a single sintering temperature zone; excessively high temperatures can cause glass deformation, while excessively low temperatures prevent the formation of a dense conductive layer. Third, their lead-free solderability is insufficient. Under environmental policies, lead-free soldering has become the industry standard. Existing silver pastes often suffer from poor composition design, leading to voids in the silver layer and poor solder wetting during soldering, resulting in insufficient joint strength. Fourth, they have weak environmental adaptability. Architectural glass is exposed to the outdoors for extended periods and needs to withstand... High and low temperature cycling (40℃~80℃), rain, snow, acid, alkali, and salt corrosion—ordinary silver paste is prone to problems such as silver layer oxidation and peeling from the glass substrate. Fifth, its service life is limited; during energization, the thermal expansion coefficient of the silver circuitry does not match that of the glass substrate, and long-term thermal stress accumulation can lead to circuit cracking and decreased conductivity, making it difficult to meet the 10-year service life requirement for building materials. These problems severely restrict the industrial application and performance upgrade of optoelectronic smart building glass. Therefore, developing a dedicated conductive silver paste adapted to glass-based circuit boards has significant practical importance and market value. Summary of the Invention

[0004] In order to solve the problems existing in the background art, the purpose of the present invention is to provide a conductive silver paste for glass-based circuit boards and its preparation method, so as to solve the problems existing in the background art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A conductive silver paste for glass-based circuit boards comprises the following components in parts by weight: 60-90 parts silver powder, 4-30 parts polymer resin, 1.5-5 parts inorganic filler, 0.05-0.5 parts additives, and 5-20 parts solvent; wherein the silver powder is spherical or nano-sized. The metallic silver powder is a mixture of spherical silver powder and nano silver powder. The components of the metallic silver powder are arranged in the following mass parts: 80-90 parts of silver powder and 5-10 parts of nano silver powder. The average particle size of the spherical silver powder is 1-2 μm and the average particle size of the nano silver powder is 100-300 nm. The solvent includes two or more of propylene glycol butyl ether, dodecyl alcohol ester, butyl carbitol, terpineol, and DBE; the polymer resin includes one or a combination of two or more of ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, cellulose acetate butyrate, and acrylic acid.

[0006] Preferably, the inorganic additives include glass powder and indium tin alloy powder.

[0007] Preferably, the glass powder is lead-free glass powder, using two types with different softening points: one with a softening point of 450-500 degrees Celsius and the other with a softening point of 650-700 degrees Celsius. Preferably, the indium-tin alloy powder has an average particle size of 1-2 micrometers. It is sintered with silver powder at a certain temperature to form a dense conductive layer, reducing voids in the silver layer, enhancing corrosion resistance, and improving solderability. Preferably, the expansion coefficient regulating powder (nickel sulfide) has an average particle size of 0.5-1 micrometer and is a type of negative thermal expansion material. It has the characteristics of thermal contraction and cold expansion, which can significantly reduce the expansion coefficient of silver circuits, ensure the lowest heat loss during power-on process, and meet the requirements of long device life.

[0008] It also includes a method for preparing the conductive silver paste for glass-based circuit boards, the method comprising the following steps: S1. Weigh the polymer resin and solvent according to the corresponding ratio, and add them to the stirring container in sequence. Stir until the mixture becomes transparent, and let it stand for more than 24 hours to obtain the organic carrier. S2. Weigh out the metallic silver powder, inorganic filler and additives, and add them sequentially to the carrier obtained in step S1. Continue to stir and disperse to obtain a uniform slurry. S3. Grind the slurry obtained in step S2, and then add solvent to it under stirring to adjust its viscosity to the range of 20,000-40,000 CPS, thus obtaining conductive silver paste. The silver paste is filtered through a 300-500 mesh screen, then weighed and packaged.

[0009] Preferably, in step S1, the obtained carrier is filtered and impurities are removed using a 200-400 mesh filter.

[0010] Compared with the prior art, the present invention has the following beneficial effects: The viscosity of the conductive silver paste can be adjusted according to requirements, making it easy to print on large screens; the sintering process can be adjusted according to the glass substrate, resulting in good weldability after sintering, long service life under power, and good resistance to temperature changes, acid, alkali, and salt chemical corrosion; even after long-term use and temperature changes, it exhibits low stress with the glass and does not detach from it. Detailed Implementation

[0011] To further optimize the application requirements of glass-based conductive silver paste: requirements for large-format printing, adjustment of sintering temperature zones, lead-free solderability, resistance to high and low temperature variations and chemical corrosion, long service life, and non-detachment from the glass substrate after prolonged use, this invention utilizes environmentally friendly solvents and resins with varying molecular weights to adjust the boiling point and state of the conductive silver paste, aiding in leveling, easy large-format printing, and fine, dense sintering. It uses lead-free glass powder with a suitable softening point as a sintering binder, and different combinations of silver powders can be used to adjust to different temperature zones, achieving consistency with the sintering temperature zones of different glass substrates. It removes some inorganic additives with poor solderability, uses chemical elements with relatively low atomic mass to improve resistance to acid, alkali, and salt corrosion, and employs bismuth-based glass powder to help adjust the softening point sintering temperature zone and solderability. Different silver powder mixing ratios can improve electrical properties and adjust the sintering temperature zone. Using glass powders and inorganic additives with different coefficients of thermal expansion adjusts the thermal expansion of the silver paste after sintering, improving stress changes at the contact between the silver wire and the glass substrate after sintering.

[0012] In a specific embodiment of the present invention, two types of silver powder are used: spherical silver powder and nano silver powder. The proportions of these silver powders are adjusted according to the sintering temperature range. For conductive silver paste with low silver content, loosely packed small silver powder can be used, while for conductive silver paste with high silver content, loosely packed large silver powder with a small specific surface area is used to ensure that the conductive silver paste maintains good printability even when the silver content is increased.

[0013] The average particle size of the spherical silver powder is generally 0.8-1.5 μm, while the particle size of the nano-silver powder is 100-300 nm. The spherical silver powder can be treated with fatty acids, alcohols, or ester surfactants to meet the requirements of different systems and help improve the state of the conductive silver paste. Different silver powders can also be obtained commercially.

[0014] The solvent used is a low molecular weight organic solvent with strong solubility and a boiling point of about 180℃-320℃. Its main function is to dissolve the resin to reduce the viscosity of the carrier and keep the conductive silver paste moist, so that the screen does not dry out 4 hours after large-area screen laying.

[0015] The combination of high and low molecular weight resins used is to maintain the consistency of the conductive silver paste state under different silver contents; including one or more of ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, cellulose acetate butyrate, and acrylic acid, and these resins have low sintering ash rate and dense circuit after sintering.

[0016] The glass powder used is made of lead-free metallic elements, specifically including one or more combinations of oxides of the following elements: bismuth, silicon, sodium, potassium, magnesium, titanium, and zirconium; for example, silicate glass powder compositions and bismuthate glass powder compositions. The average particle size of the glass powder is generally controlled between 0.1 μm and 5 μm, and the softening point is generally controlled between 350℃ and 750℃, with the softening point adjusted according to the thickness of the glass substrate and the sintering process.

[0017] In order to provide a clearer understanding of the technical features, methods, objectives, and beneficial effects of the present invention, the technical solution of the present invention will now be described in detail below, but this should not be construed as limiting the scope of implementation of the present invention.

[0018] The process mainly consists of five steps: 1. Carrier preparation; 2. Silver powder preparation; 3. Selection of glass powder and inorganic additives; 4. Mixing the carrier, silver powder, glass powder and inorganic additives and then pulping them through a rolling mill; 5. Printing, sintering and testing.

[0019] Example 1 Carrier preparation: Ethyl cellulose and acrylic resin are mixed in a 2:1 mass ratio as the resin. The solvent is a mixture of butyl carbitol, dodecayl alcohol, and terpineol in a 6:3:1 mass ratio. The mixed solvent and resin are combined at a resin content of 30% and then dissolved in an 80℃ oven. Stirring is required during the process. After dissolution, the mixture is cooled and ready for use. This carrier is characterized by its suitability for high silver content and low viscosity. It produces a high-quality silver paste with fine texture, and possesses leveling properties and micro-thixotropy, ensuring optimal printing performance.

[0020] Silver powder formulation: 85 parts of spherical silver powder with an average particle size of 1-2 μm and 5 parts of nano silver powder with a particle size of 100-300 nm are mixed together. Characteristics of the mixed silver powder: Spherical powder can reduce the viscosity of conductive silver paste; microspherical silver powder, flake silver powder, and nano silver powder have low resistance after sintering, and at the same time adjust the sintering activity, match the glass, and have good solderability; flake silver powder also brings a small amount of thixotropic thickening.

[0021] Glass powder: Prepare lead-free glass powder with the following mass ratio: Bi2O3 45%, ZnO 8%, CaO 4%, SiO2 18%, B2O3 10%, Na2O 3%, K2O 2%, and others 10%.

[0022] Mix 85 parts silver powder, 3 parts glass powder, 0.5 parts indium tin alloy powder, 0.05 parts expansion coefficient adjusting powder, 10 parts mixed carrier, and 1.45 parts other solvents. After mixing, the mixture is pulped using a rolling mill. The amount of the remaining 1.45 components of other solvents is adjusted according to the customer's printing screen size and printing speed to adjust the viscosity of the conductive silver paste to the predetermined requirement of 40 Pa·s. The paste is then printed through a 150-300 mesh polyester screen or steel wire screen, dried, and sintered at 600℃-750℃ for 3-5 minutes.

[0023] Testing includes: Printability: viscosity and flowability, creep, rheological changes after aging in humidity and temperature, agglomeration, sedimentation after prolonged storage, and dry screen condition. Conductivity: resistance and circuit temperature. Appearance: color, light transmission effect, and uniformity and aesthetics of the circuit. Solderability: tensile strength, lead-free solderability, solderability, presence of pores, and solder solvent penetration. Mechanical resistance: scratch resistance, abrasion resistance, and cracking at the bonding interface between the glass and silver paste in a drop ball test. Chemical resistance: resistance to chemical corrosion, oxidation discoloration, aging test, temperature difference changes, and boiling water changes.

[0024] Analysis of the above technical content: Raw material analysis: The silver powder system is a blend of 85 parts spherical silver powder (1-2μm) and 5 parts nano silver powder (100-300nm). The spherical silver powder can reduce the viscosity of the silver paste and improve the smoothness of printing, while the nano silver powder can enhance the sintering activity. The two work together to make the circuit resistance lower after sintering and optimize the solderability. The silver powder is treated with surfactants to further improve its compatibility with organic carriers and avoid agglomeration.

[0025] The resin is a blend of ethyl cellulose and acrylic resin (mass ratio 2:1), which has both low residual ash rate and good leveling properties. It is combined with a mixed solvent of butyl carbitol, dodecayl alcohol, and terpineol (6:3:1), with a boiling point range of 180℃-320℃. This ensures that the resin is fully dissolved to form a low-viscosity carrier and maintains the wettability of the silver paste for a long time, meeting the requirement of 4 hours of non-drying screen printing in large-format printing.

[0026] In the inorganic filler, lead-free glass powder with Bi2O3 as the main component, combined with oxides such as ZnO and SiO2, has a softening point suitable for sintering processes of 600℃-750℃, and can form a stable chemical bond with the glass substrate; 0.5 parts of indium tin alloy powder (1-2μm) can fill the gaps in the silver layer, form a dense conductive structure, and improve corrosion resistance and solderability; 0.05 parts of nickel sulfide (0.5-1μm) serves as a negative thermal expansion material, which can offset the thermal expansion of the silver circuit and reduce the stress difference with the glass substrate.

[0027] Core process analysis: The carrier is prepared by melting in an 80℃ oven and then cooling and settling. The resin content is controlled at 30%, and the carrier is filtered through a 200-400 mesh screen to remove impurities, ensuring the purity and uniformity of the carrier and laying the foundation for subsequent printing performance.

[0028] After mixing and stirring, the paste is pulped through a rolling mill, and the amount of additional solvent added (1.45 parts) is precisely controlled to adjust the viscosity of the silver paste to 40 Pa·s, which is suitable for 150-300 mesh screen printing and meets the leveling and thixotropic requirements of large-format printing.

[0029] The sintering process uses parameters of 600℃-750℃ / 3-5min, which ensures that the lead-free glass powder is fully softened and bonded, avoids deformation of the glass substrate, and promotes the densification reaction of silver powder and indium tin alloy powder.

[0030] Technical benefits: The silver paste prepared by this method has extremely strong printing adaptability, enabling large-area uniform printing without dripping or dry screen phenomena; after sintering, the circuit resistance is low, the density is good, and there are no void defects; it has excellent lead-free solderability, the welding tensile strength meets the standard, and the solder wetting is uniform; the addition of nickel sulfide makes the thermal expansion coefficient of the silver circuit match that of the glass substrate, and after high and low temperature cycling and aging tests, there is no peeling or cracking; it has outstanding resistance to acid, alkali and salt corrosion and oxidation discoloration, and its service life is far longer than that of ordinary silver paste, making it fully suitable for outdoor use scenarios of optoelectronic architectural glass.

[0031] Example 2 Carrier Preparation: The resin used is cellulose acetate. The mixed solvent consists of 60 parts of a plasticizer (alcohol ester twelve) and 40 parts of butyl carbitol, which have relatively high leveling and viscosity properties. The resin, cellulose acetate, and mixed solvent are mixed at a mass content of 35%, and then placed in an 80℃ oven and stirred to dissolve. After natural cooling, it is set aside for later use. Carrier Specifics: High viscosity, strong thixotropy, and good leveling properties, suitable for the preparation of low-silver-content conductive silver paste.

[0032] Silver powder preparation: 80 parts of spherical silver powder with an average particle size of 1-2 μm and 5 parts of nano silver powder with a particle size of 100-300 nm are mixed together. Characteristics of the mixed silver powder: high viscosity, good thixotropy, low electrical resistance, and good sintering activity.

[0033] Prepare lead-free glass powder with the following mass ratio: Bi2O 45%, ZnO 8%, CaO 4%, SiO2 18%, B2O3 10%, Na2O 3%, K2O 2%, and others 10%.

[0034] Mix 60 parts silver powder, 5 parts glass powder, 0.5 parts indium tin alloy powder, 0.05 parts expansion coefficient adjusting powder, 30 parts carrier, and 4.45 parts other solvents. After mixing, the mixture is pulped using a rolling mill. The amount of the remaining 4.45 components of solvents is adjusted according to the customer's printing screen size and printing speed to adjust the viscosity of the conductive silver paste to the predetermined requirement of 45 Pa·s. The paste is then printed on a 150-300 mesh polyester or steel wire mesh, dried at 180℃, and sintered at 600℃-750℃ for 3-5 minutes.

[0035] Testing includes: Printability: viscosity and flowability, creep, rheological changes after aging in humidity and temperature, agglomeration, sedimentation after prolonged storage, and dry screen condition. Conductivity: resistance and circuit temperature. Appearance: color, light transmission effect, and uniformity and aesthetics of the circuit. Solderability: tensile strength, lead-free solderability, solderability, presence of pores, and solder solvent penetration. Mechanical resistance: scratch resistance, abrasion resistance, and cracking at the bonding interface between the glass and silver paste in a drop ball test. Chemical resistance: resistance to chemical corrosion, oxidation discoloration, aging test, temperature difference changes, and boiling water changes.

[0036] Analysis of the above technical content: Raw material analysis: The silver powder system is a mixture of 80 parts of spherical silver powder (1-2μm) and 5 parts of nano silver powder (100-300nm). Compared with Example 1, the proportion of spherical silver powder is reduced. While ensuring conductivity, the thixotropic properties of the silver paste are improved, which is suitable for the viscosity requirements of low silver content formulations.

[0037] The resin used is cellulose acetate, combined with a mixed solvent of dodecyl alcohol ester and butyl carbitol (6:4). The carrier resin content is increased to 35%, resulting in higher viscosity and stronger thixotropy. This effectively avoids the problem of silver paste dripping under low silver content, while ensuring low residual ash rate after sintering and not affecting conductivity.

[0038] The inorganic filler ratio is consistent with that of Example 1. The softening point of the lead-free glass powder is precisely matched with the sintering process. The synergistic effect of indium tin alloy powder and nickel sulfide ensures that a dense structure and low stress bonding can still be achieved even with low silver content.

[0039] Core process analysis: The carrier preparation also adopts the process of stirring and dissolving in an 80℃ oven and natural cooling. The high resin content (35%) design enhances the carrier's adhesion and thixotropy, making it suitable for the dispersion and stability of low silver content systems.

[0040] During the pulping process, the viscosity was adjusted to 45 Pa·s by adjusting the amount of additional solvent added (4.45 parts), which balances the printing smoothness and circuit forming effect of low silver content silver paste, and is suitable for different screen sizes and printing speeds.

[0041] Adding a 180℃ drying pretreatment step can remove some of the low-boiling-point solvents in the silver paste in advance, avoiding bubbles generated by rapid solvent evaporation during sintering, and further improving the density of the circuit.

[0042] Technical Benefits: This solution is designed for low silver content applications. The silver paste exhibits strong thixotropy and stable viscosity, resulting in clear lines with no diffusion during printing, making it suitable for small-area, high-precision printing scenarios. The combined process of 180℃ drying and high-temperature sintering ensures excellent line quality, uniform and aesthetically pleasing appearance, and minimal impact on glass transmittance. It meets lead-free solderability and corrosion resistance standards, exhibits outstanding mechanical resistance, and demonstrates good scratch and abrasion resistance. No cracking occurred at the bond between the glass and silver paste during the drop ball test. After aging tests such as temperature variation and boiling water, it maintains stable conductivity and bonding strength. Compared to high silver content solutions, it offers a cost advantage and is suitable for cost-sensitive mass production applications.

[0043] Comparative Example 1 The mixture consists of 85 parts of ordinary spherical silver powder, 10 parts of ethyl cellulose carrier with a content of 20%, 4 parts of glass powder, and 1 part of solvent.

[0044] This comparative example is a comparison experiment between Example 1 and Example 2. The differences between the comparative example and Example 1 are as follows: 1. The conductive silver paste in the comparative example is of a general state and is relatively difficult to adjust. The examples can be adjusted according to viscosity and printing requirements, including the type and ratio of silver powder, the type and content of the carrier (resin type, ratio and content, solvent type, ratio and content). 2. The comparative example is a conventional sintering conductive silver paste, with a single sintering temperature range that is difficult to adjust. Its solderability after sintering is worse than Example 1 and Example 2. The examples can adjust the sintering temperature range according to the glass substrate, including the type and ratio of silver powder and the type of glass powder. 3. The glass powder is unknown, making it difficult to guarantee its influence on the glass. Furthermore, its chemical resistance, temperature change resistance, aging resistance, and mechanical properties cannot be guaranteed. 4. The resistance is generally low; with the same silver content, it cannot be lower than that of Examples 1 and 2. The examples, by using silver micronized flakes, can achieve lower resistance. However, it is difficult to adjust the silver powder content to a higher level, limiting the formulation flexibility. The examples can increase the silver content while maintaining the same viscosity by changing the carrier ratio, or decrease it while maintaining the same viscosity. Fifth, the comparative example is too simple. Its leveling properties and sintering density are not as good as those of the examples. It is also not as good as Examples 1 and 2 in terms of oxidation discoloration, welding color penetration, and porosity.

[0045] In a specific embodiment of the present invention, the resin needs to be dissolved in solvents such as dodecayl alcohol ester, butyl carbitol, and terpineol to form a carrier (including different types of solvents, different resin combinations, and different resin concentrations). Then, it is mixed with silver powder, glass powder, and inorganic additives and rolled into a semi-finished product. Then, ethanol, isopropanol, and auxiliaries are mixed in and rolled to form internal hydrogen bonds.

[0046] The above examples illustrate the present invention only to aid in understanding it and are not intended to limit the scope of the invention. Those skilled in the art can make various simple deductions, modifications, or substitutions based on the principles of this invention.

Claims

1. A glass-based circuit board specific electrically conductive silver paste, characterized by: The silver paste comprises the following components by mass: 60-90 parts of silver powder, 4-30 parts of high molecular resin, 1.5-5 parts of inorganic filler, 0.05-0.5 parts of auxiliary agent and 5-20 parts of solvent; the silver powder is spherical nano silver powder; The metal silver powder is a mixture of spherical silver powder and nano silver powder, and the components in the metal silver powder are composed of 80-90 parts of silver powder and 5-10 parts of nano silver powder by mass fraction, wherein the average particle size of the spherical silver powder is 1-2 μm, and the average particle size of the nano silver powder is 100-300 nm; The solvent comprises two or more of propylene glycol butyl ether, alcohol ester twelve, butyl carbitol, terpineol, DBE; the high molecular resin comprises one or a combination of two or more of ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, cellulose acetate butyrate and acrylic acid.

2. The glass-based circuit board specific electrically conductive silver paste of claim 1, wherein: The auxiliary agent inorganic additive comprises glass powder and indium tin alloy powder.

3. The glass-based circuit board specific electrically conductive silver paste of claim 2, wherein: The glass powder is lead-free glass powder, and two high and low softening points are adopted, one of which is 450-500 degrees, and the other is 650-700 degrees.

4. The glass-based circuit board specific electrically conductive silver paste of claim 2, wherein: The average particle size of the indium tin alloy powder is 1-2 microns, and the silver powder is sintered at a certain temperature to form a dense conductive layer, reduce the voids of the silver layer, enhance the corrosion resistance and improve the weldability.

5. The glass-based circuit board specific electrically conductive silver paste of claim 2, wherein, The average particle size of the expansion coefficient adjusting powder (nickel sulfide) is 0.5-1 micron, which is a kind of negative thermal expansion material with the characteristics of thermal shrinkage and cold expansion, which can significantly reduce the expansion coefficient of the silver circuit, ensure the lowest heat loss in the process of power supply, and achieve the requirement of long service life of the device.

6. A method of preparing the glass-based circuit board-specific conductive silver paste according to any one of claims 1 to 5, characterized by: The method comprises the following steps: S1, the high molecular resin and the solvent are weighed according to the corresponding ratio, and then they are added into the stirring container in sequence, stirred to be transparent, and then an organic carrier is obtained after standing for more than 24 hours; S2, the metal silver powder, the inorganic filler and the auxiliary agent are weighed and added into the carrier obtained in step S1 in sequence, and then the stirring and dispersion are continued to obtain a uniform slurry; S3, the slurry obtained in step S2 is ground, and then the solvent is added thereto under stirring to adjust the viscosity to be in the range of 20000-40000 CPS, and then a conductive silver paste is obtained; After the silver paste is filtered through a 300-500 mesh screen, it is weighed and packaged.

7. The method for preparing conductive silver paste for glass-based circuit boards according to claim 6, characterized in that: In step S1, the obtained carrier is filtered through a 200-400 mesh screen to remove impurities.