Lead solder paste for preventing tin explosion and preparation method thereof

Abstract

The application discloses a lead soldering paste capable of preventing tin explosion and a preparation method thereof. The lead soldering paste comprises the following components in parts by weight: soldering paste 8-12 parts, anti-water absorption composite material 5-10 parts and lead soldering powder 80-90 parts. The soldering paste comprises the following components in parts by weight: rosin 30-50 parts, solvent 30-50 parts, additive 3-15 parts, thixotropic agent 4-8 parts, organic acid 5-10 parts, halogen compound 1-5 parts and antioxidant 0.5-5 parts. In the application, the montmorillonite composite material is immersed in a prepared resin solution to form a resin layer with strong anti-water absorption performance on the surface of the montmorillonite composite material, thereby forming the anti-water absorption composite material. When the anti-water absorption composite material is introduced into the soldering paste, the anti-water absorption composite material has a multi-layer structure, can form a multi-layer dense continuous phase structure anti-water absorption layer by mutual embedding and insertion, effectively prevents the penetration of water in the air, reduces the absorption of water by the soldering paste in a high-humidity environment, thereby avoiding the occurrence of tin explosion in soldering, and remarkably promotes the improvement of product yield and production efficiency.

Description

Technical Field

[0001] This invention relates to the field of welding materials technology, specifically to a leaded solder paste that prevents solder from exploding and its preparation method. Background Technology

[0002] With the rapid development of the electronics industry, electronic components are becoming increasingly integrated and miniaturized. Electronic assembly technology is shifting towards micro-assembly technologies, represented by surface mount technology (SMT). This places increasingly higher demands on soldering techniques and materials. Solder development and preparation are becoming more specialized, serialized, and refined. Solder paste has become the most important process material in surface mount technology (SMT). In the reflow soldering of SMT components, solder paste is used to connect the leads or breaks of SMT components to the pads on the printed circuit board. Solder paste application is a critical step in SMT technology, directly affecting the soldering quality and reliability of SMT components. Typically, defects caused by solder paste account for 60-70% of defects in SMT.

[0003] For example, the invention patent with announcement number CN101143407A discloses a solder paste and its preparation method. The components and weight percentage content of this solder paste are as follows: 80-90% alloy solder powder, 6-8% organic solvent, 1-8% organic acid, 2-10% resin, and 0.2-2% surfactant. This solder paste contains a suitable ratio of surfactant, which acts on the surface of the solder joint during soldering, thereby making the solder joint full and bright. However, when this type of solder paste is used in a high humidity environment, it will continuously absorb moisture from the air, which will increase the water content of the solder paste. During reflow soldering, if the moisture in the solder paste is not removed in time, the temperature will rise too quickly, and the moisture in the system will splash out with the flux and solder powder, forming a solder splatter phenomenon. This will lead to problems such as component misalignment, solder balls, solder bridging, incomplete solder joints, and low solder strength, thereby reducing product yield and production efficiency. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention aims to provide a leaded solder paste that prevents solder from exploding and its preparation method.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A leaded solder paste that prevents solder from exploding, the leaded solder paste comprising the following components by weight: 8-12 parts flux paste, 5-10 parts water-resistant composite material, and 80-90 parts leaded solder powder;

[0007] The flux paste comprises the following components by weight: 30-50 parts rosin, 30-50 parts solvent, 3-15 parts additives, 4-8 parts thixotropic agent, 5-10 parts organic acid, 1-5 parts halogen compound, and 0.5-5 parts antioxidant.

[0008] As a further preferred embodiment of the present invention, the rosin is composed of KE-604, AX-E and CH-60 rosin in a mass ratio of 1:1:(0.2-0.5);

[0009] The solvent is at least one of diethylene glycol dibutyl ether and tripropylene glycol butyl ether;

[0010] The additive is at least one of polyisobutylene 300R and dimer acid;

[0011] The thixotropic agent is at least one of hydrogenated castor oil and ethylene bis-stearamide;

[0012] As a further preferred embodiment of the present invention, the organic acid is at least one selected from adipic acid, octanoic acid, sebacic acid, tetracosic acid, and dodecanoic acid;

[0013] The halogen compound is at least one of dibromobutenediol and diphenylguanidine hydrobromide;

[0014] The antioxidant is at least one of antioxidant 245 and antioxidant 1010.

[0015] As a further preferred embodiment of the present invention, the method for preparing the water-absorbing composite material is as follows:

[0016] 1) Add phenol to the reactor, then add formaldehyde solution and oxalic acid solution, heat to 85-87℃ and react for 30-50 min. After the reaction is complete, dehydrate under vacuum, then cool to 80-83℃, add triethanolamine to adjust the pH to neutral, add epoxidized soybean oil, 1-methylimidazole and triethylamine, heat to 120-125℃ and keep the temperature for 1-3 h, then add 4,4'-diaminodiphenylmethane and continue to keep the temperature for 1-3 h to obtain the resin material;

[0017] 2) At room temperature, dissolve hexadecylpyridine in deionized water and ultrasonically disperse for 15-30 min to obtain a hexadecylpyridine modifier solution. Then dissolve montmorillonite in the hexadecylpyridine modifier solution and magnetically stir at room temperature for 6-10 h to obtain a suspension.

[0018] 3) Sodium dodecylbenzenesulfonate was dissolved in deionized water and ultrasonically dispersed to obtain a sodium dodecylbenzenesulfonate modifier solution. Then, it was added to the suspension. Under magnetic stirring, hydrochloric acid solution was added to adjust the pH value to 5.0-5.5. Then, it was heated and stirred in a water bath at 60-65℃ for 3-5 hours and allowed to stand for aging for 15-20 hours to obtain the product. After centrifugation, washing, drying, and grinding into powder, the organic modified montmorillonite was obtained.

[0019] 4) Add the organically modified montmorillonite to deionized water and stir at 70-75℃ for 1-3 hours. Then add sodium dodecyl sulfate and continue stirring for 1-2 hours. Next, add methyl methacrylate and stir for 30-50 minutes. Then raise the temperature to 86-88℃ and slowly add ammonium persulfate. Continue stirring and react for 8-12 hours. After the reaction is complete, cool to room temperature, extract with acetone, precipitate with ethanol, wash repeatedly with deionized water, and dry to obtain the montmorillonite composite material.

[0020] 5) Cool the resin material to 90-95℃, add toluene, mix thoroughly, and continue cooling to 50-55℃. Then add a mixture of toluene and methanol, mix well, and add hexamethylenetetramine to obtain a resin solution. Add montmorillonite composite material to the resin solution, stir and disperse thoroughly, centrifuge, and after curing, the water-resistant composite material can be obtained.

[0021] As a further preferred embodiment of the present invention, in step 1), the mass ratio of phenol, formaldehyde solution, oxalic acid solution, epoxidized soybean oil, 1-methylimidazole, triethylamine, and 4,4'-diaminodiphenylmethane is (100-150):(85-100):(3-6):(15-20):(1-2):(0.8-1.3):(2-5);

[0022] The concentration of the formaldehyde solution is 35-37 wt%.

[0023] The concentration of the oxalic acid solution is 50-53 wt%.

[0024] As a further preferred embodiment of the present invention, in step 2), the ratio of the amount of hexadecyl chloride, deionized water and montmorillonite in the suspension is (1-2)g:(50-80)mL:(2-5)g.

[0025] As a further preferred embodiment of the present invention, in step 3), the ratio of sodium dodecylbenzenesulfonate, deionized water, and suspension is (0.5-1.3)g:(20-50)mL:(50-80)mL;

[0026] The concentration of the hydrochloric acid solution is 0.1-0.3 mol / L.

[0027] As a further preferred embodiment of the present invention, in step 4), the ratio of the amount of organic modified montmorillonite, deionized water, sodium dodecyl sulfate, methyl methacrylate and ammonium persulfate is (0.5-1.0)g:(300-400)mL:(1.2-1.8)g:(20-26)mL:(0.2-0.5)g.

[0028] As a further preferred embodiment of the present invention, in step 5), the mass ratio of the resin material, toluene, mixture, hexamethylenetetramine, and montmorillonite composite material is (50-80):(5-10):(10-16):(2-5):(15-20);

[0029] The mixture is composed of toluene and methanol in a volume ratio of 1:(0.5-0.8).

[0030] A method for preparing a leaded solder paste that prevents solder blasting specifically includes the following steps:

[0031] 1) Prepare each component according to the weight proportions. Heat the rosin, solvent, additives, and thixotropic agent together to 150-156℃. After the system is dissolved and mixed evenly, the temperature is reduced to 130-135℃. Add the organic acid, halogen compound, and antioxidant. After it is completely dissolved, continue stirring for 2-6 minutes to mix it evenly. Transfer the evenly mixed material to a sealed beaker and cool it in ice water for 1-2 hours. Take it out and return it to room temperature. Grind it 1-2 times to obtain the flux.

[0032] 2) Mix the flux, water-resistant composite material and leaded solder powder, and stir until the mixture is uniform to obtain solder paste.

[0033] Compared with the prior art, the beneficial effects of the present invention are:

[0034] In this invention, a tertiary amine is used as an etherification catalyst, and a complex polyamine is used as a chain extender to extend and polymerize epoxidized soybean oil and graft it onto phenolic resin, achieving cross-linking polymerization of soft and hard segments to obtain a resin material. In this resin material, chain extension and etherification modification enable the chain-extended polymer and phenolic resin to form a relatively tight cross-linked network, which can play a good role in shielding hydroxyl groups, thereby preventing water from diffusing into the interior and achieving a good anti-water absorption effect. At the same time, etherification treatment can effectively block some phenolic hydroxyl groups, and the hydrophobic chain-extended polymer can shield the remaining phenolic hydroxyl groups, thereby further preventing water diffusion and enhancing the anti-water absorption effect. Furthermore, by organically modifying montmorillonite with hexadecylpyridine chloride and sodium dodecylbenzenesulfonate, and then using intercalation polymerization, the polymer and organically modified montmorillonite are composited to obtain a montmorillonite composite material. Since the main component of montmorillonite is silicon... Aluminates, with their multifunctional lamellar structure, intercalate with polymer monomers and act as crosslinking agents to a certain extent, promoting the increase of crosslinking density in composite materials and facilitating the formation of crosslinked structures. This results in excellent water resistance in the composite material. Furthermore, by controlling the content of organically modified montmorillonite, the proportion of intercalated polymer monomers is relatively reduced, and montmorillonite fills most of the volume of the crosslinked network structure, further hindering the absorption of water molecules. Moreover, because the organically modified montmorillonite with a large aspect ratio is uniformly dispersed in the montmorillonite composite matrix, the diffusion of water in the montmorillonite composite matrix must bypass these lamellar layers, thereby increasing the effective pathway for water diffusion in the montmorillonite composite matrix and improving the water barrier performance of the montmorillonite composite material, thus further reducing water penetration and improving water resistance.

[0035] In this invention, montmorillonite composite material is immersed in a prepared resin solution to form a resin layer with strong water-absorbing properties on its surface, thus forming an anti-water-absorbing composite material. This material is then introduced into solder paste. Utilizing its multi-layered structure, it can interlock to form a multi-layered, dense, continuous phase structure of anti-water-absorbing layer, effectively preventing the penetration of moisture from the air and reducing the absorption of moisture by the solder paste in high-humidity environments. This avoids solder splattering during soldering and significantly promotes improved product yield and production efficiency. Detailed Implementation

[0036] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] In this embodiment of the invention, the rosin is composed of KE-604, AX-E and CH-60 rosin in a mass ratio of 1:1:0.5; the solvent is diethylene glycol dibutyl ether; the additive is polyisobutylene 300R; the thixotropic agent is hydrogenated castor oil; the organic acid is adipic acid; the halogen compound is dibromobutenediol; and the antioxidant is antioxidant 245.

[0038] Example 1

[0039] A leaded solder paste that prevents solder from exploding, the leaded solder paste comprising the following components by weight: 8 parts flux, 5 parts water-resistant composite material, and 80 parts leaded solder powder;

[0040] The flux paste comprises the following components by weight: 30 parts rosin, 30 parts solvent, 3 parts additive, 4 parts thixotropic agent, 5 parts organic acid, 1 part halogen compound, and 0.5 parts antioxidant.

[0041] The preparation method of this lead-based solder paste specifically includes the following steps:

[0042] 1) Prepare each component according to the weight proportions. Heat the rosin, solvent, additives and thixotropic agent together to 150°C. After the system is dissolved and mixed evenly, the temperature is reduced to 130°C. Add organic acid, halogen compound and antioxidant. After it is completely dissolved, continue to stir for 2 minutes to make it evenly mixed. Transfer the evenly mixed material to a sealed beaker and cool it in ice water for 1 hour. Take it out and return it to room temperature. Grind it once to obtain the flux.

[0043] 2) Mix the flux, water-resistant composite material and leaded solder powder, and stir until the mixture is uniform to obtain solder paste.

[0044] The preparation method of the water-absorbing composite material is as follows:

[0045] 1) Add 100g of phenol to the reactor, then add 85g of 35wt% formaldehyde solution and 3g of 50wt% oxalic acid solution. Heat to 85℃ and react for 30min. After the reaction is complete, dehydrate under vacuum and then cool to 80℃. Add triethanolamine to adjust the pH to neutral. Add 15g of epoxidized soybean oil, 1g of 1-methylimidazole and 0.8g of triethylamine. Heat to 120℃ and keep the temperature for 1h. Then add 2g of 4,4'-diaminodiphenylmethane and continue to keep the temperature for 1h to obtain the resin material.

[0046] 2) At room temperature, 1 g of hexadecylpyridine chloride was dissolved in 50 mL of deionized water and ultrasonically dispersed for 15 min to obtain a hexadecylpyridine chloride modifier solution. Then, 2 g of montmorillonite was dissolved in the hexadecylpyridine chloride modifier solution and magnetically stirred at room temperature for 6 h to obtain a suspension.

[0047] 3) Dissolve 0.5g of sodium dodecylbenzenesulfonate in 20mL of deionized water and disperse it by ultrasonication to obtain a sodium dodecylbenzenesulfonate modifier solution. Then add it to 50mL of suspension. Under magnetic stirring, add 0.1mol / L hydrochloric acid solution to adjust the pH value to 5.0. Then heat and stir in a 60℃ water bath for 3h, let it stand and age for 15h to obtain the product. After centrifugation, washing, drying, and grinding into powder, the organic modified montmorillonite is obtained.

[0048] 4) Add 0.5g of organically modified montmorillonite to 300mL of deionized water, stir at 3000r / min for 1h at 70℃, then add 1.2g of sodium dodecyl sulfate, continue stirring for 1h, then add 20mL of methyl methacrylate, stir for 30min, raise the temperature to 86℃, slowly add 0.2g of ammonium persulfate, continue stirring and react for 8h. After the reaction is complete, cool to room temperature, extract with acetone, precipitate with ethanol, wash repeatedly with deionized water and dry to obtain montmorillonite composite material;

[0049] 5) Cool 50g of resin material to 90℃, add 5g of toluene, mix thoroughly, and continue cooling to 50℃. Then add 10g of a mixture of toluene and methanol in a volume ratio of 1:0.5, mix well, and add 2g of hexamethylenetetramine to obtain a resin solution. Add 15g of montmorillonite composite material to the resin solution, stir thoroughly to disperse evenly, centrifuge, and after curing, the water-resistant composite material can be obtained.

[0050] Example 2

[0051] A leaded solder paste that prevents solder from exploding, comprising the following components by weight: 10 parts flux, 8 parts water-resistant composite material, and 85 parts leaded solder powder.

[0052] The flux paste comprises the following components by weight: 40 parts rosin, 40 parts solvent, 10 parts additives, 6 parts thixotropic agent, 8 parts organic acid, 3 parts halogen compound, and 2.5 parts antioxidant.

[0053] The preparation method of this lead-based solder paste specifically includes the following steps:

[0054] 1) Prepare each component according to the weight proportions. Heat the rosin, solvent, additives and thixotropic agent together to 153°C. After the system is dissolved and mixed evenly, the temperature is reduced to 132°C. Add organic acid, halogen compound and antioxidant. After it is completely dissolved, continue to stir for 5 minutes to mix evenly. Transfer the evenly mixed material to a sealed beaker and cool it in ice water for 1.5 hours. Take it out and return it to room temperature. Grind it twice to obtain the flux.

[0055] 2) Mix the flux, water-resistant composite material and leaded solder powder, and stir until the mixture is uniform to obtain solder paste.

[0056] The preparation method of the water-absorbing composite material is as follows:

[0057] 1) Add 130g of phenol to the reactor, then add 95g of 36wt% formaldehyde solution and 5g of 52wt% oxalic acid solution. Heat to 86℃ and react for 40min. After the reaction is complete, dehydrate under vacuum and then cool to 82℃. Add triethanolamine to adjust the pH to neutral. Add 18g of epoxidized soybean oil, 1.5g of 1-methylimidazole and 1g of triethylamine. Heat to 123℃ and keep the temperature for 2h. Then add 3g of 4,4'-diaminodiphenylmethane and continue to keep the temperature for 2h to obtain the resin material.

[0058] 2) At room temperature, 1.5 g of hexadecylpyridine chloride was dissolved in 70 mL of deionized water and ultrasonically dispersed for 20 min to obtain a hexadecylpyridine chloride modifier solution. Then, 3 g of montmorillonite was dissolved in the hexadecylpyridine chloride modifier solution and magnetically stirred at room temperature for 8 h to obtain a suspension.

[0059] 3) Dissolve 1g of sodium dodecylbenzenesulfonate in 35mL of deionized water and disperse it by ultrasonication to obtain a sodium dodecylbenzenesulfonate modifier solution. Then add it to 70mL of suspension. Under magnetic stirring, add 0.2mol / L hydrochloric acid solution to adjust the pH value to 5.5. Then heat and stir in a 62℃ water bath for 4h, let it stand and age for 18h to obtain the product. After centrifugation, washing, drying, and grinding into powder, the organic modified montmorillonite is obtained.

[0060] 4) Add 0.8g of organically modified montmorillonite to 350mL of deionized water and stir at 4000r / min for 2h at 72℃. Then add 1.5g of sodium dodecyl sulfate and continue stirring for 1.5h. Add 23mL of methyl methacrylate and stir for 40min. Then raise the temperature to 87℃ and slowly add 0.3g of ammonium persulfate. Continue stirring and react for 10h. After the reaction is complete, cool to room temperature, extract with acetone, precipitate with ethanol, wash repeatedly with deionized water and dry to obtain montmorillonite composite material.

[0061] 5) Cool 70g of resin material to 93℃, add 7g of toluene, mix thoroughly, and continue cooling to 52℃. Then add 15g of a mixture of toluene and methanol in a volume ratio of 1:0.7, mix well, and add 3g of hexamethylenetetramine to obtain a resin solution. Add 17g of montmorillonite composite material to the resin solution, stir thoroughly to disperse evenly, centrifuge, and after curing, the water-resistant composite material can be obtained.

[0062] Example 3

[0063] A leaded solder paste that prevents solder from exploding, the leaded solder paste comprising the following components in parts by weight: 12 parts flux paste, 10 parts water-resistant composite material, and 90 parts leaded solder powder;

[0064] The flux paste contains the following components by weight: 50 parts rosin, 50 parts solvent, 15 parts additives, 8 parts thixotropic agent, 10 parts organic acid, 5 parts halogen compound, and 5 parts antioxidant.

[0065] The preparation method of this lead-based solder paste specifically includes the following steps:

[0066] 1) Prepare each component according to the weight proportions. Heat the rosin, solvent, additives and thixotropic agent together to 156°C. After the system is dissolved and mixed evenly, the temperature is reduced to 135°C. Add organic acid, halogen compound and antioxidant. After it is completely dissolved, continue to stir for 6 minutes to make it evenly mixed. Transfer the evenly mixed material to a sealed beaker and cool it in ice water for 2 hours. Take it out and return it to room temperature. Grind it twice to obtain the flux.

[0067] 2) Mix the flux, water-resistant composite material and leaded solder powder, and stir until the mixture is uniform to obtain solder paste.

[0068] The preparation method of the water-absorbing composite material is as follows:

[0069] 1) Add 150g of phenol to the reactor, then add 100g of 37wt% formaldehyde solution and 6g of 53wt% oxalic acid solution. Heat to 87℃ and react for 50min. After the reaction is complete, dehydrate under vacuum and then cool to 83℃. Add triethanolamine to adjust the pH to neutral. Add 20g of epoxidized soybean oil, 2g of 1-methylimidazole and 1.3g of triethylamine. Heat to 125℃ and keep the temperature for 3h. Then add 5g of 4,4'-diaminodiphenylmethane and continue to keep the temperature for 3h to obtain the resin material.

[0070] 2) At room temperature, 2g of hexadecylpyridine chloride was dissolved in 80mL of deionized water and ultrasonically dispersed for 30min to obtain a hexadecylpyridine chloride modifier solution. Then, 5g of montmorillonite was dissolved in the hexadecylpyridine chloride modifier solution and magnetically stirred at room temperature for 10h to obtain a suspension.

[0071] 3) Dissolve 1.3g of sodium dodecylbenzenesulfonate in 50mL of deionized water and disperse it by ultrasonication to obtain a sodium dodecylbenzenesulfonate modifier solution. Then add it to 80mL of suspension. Under magnetic stirring, add 0.3mol / L hydrochloric acid solution to adjust the pH value to 5.5. Then heat and stir in a 65℃ water bath for 5h, let it stand and age for 20h to obtain the product. After centrifugation, washing, drying, and grinding into powder, obtain organic modified montmorillonite.

[0072] 4) Add 1g of organically modified montmorillonite to 400mL of deionized water, stir at 5000r / min for 3h at 75℃, then add 1.8g of sodium dodecyl sulfate, continue stirring for 2h, then add 26mL of methyl methacrylate, stir for 50min, raise the temperature to 88℃, slowly add 0.5g of ammonium persulfate, continue stirring and react for 12h. After the reaction is complete, cool to room temperature, extract with acetone, precipitate with ethanol, wash repeatedly with deionized water and dry to obtain montmorillonite composite material;

[0073] 5) Cool 80g of resin material to 95℃, add 10g of toluene, mix thoroughly, and continue cooling to 55℃. Then add 16g of a mixture of toluene and methanol in a volume ratio of 1:0.8, mix well, and add 5g of hexamethylenetetramine to obtain a resin solution. Add 20g of montmorillonite composite material to the resin solution, stir thoroughly to disperse evenly, centrifuge, and after curing, the water-resistant composite material can be obtained.

[0074] Comparative Example 1: This comparative example is basically the same as Example 1, except that it does not contain water-resistant composite material.

[0075] Comparative Example 2: This comparative example is basically the same as Example 1, except that montmorillonite is used instead of montmorillonite composite material in the preparation of the water-absorbing composite material.

[0076] Comparative Example 3: This comparative example is basically the same as Example 1, except that the resin material is omitted in the preparation of the water-absorbing composite material.

[0077] Comparative Example 4: This comparative example is basically the same as Example 1, except that montmorillonite is used instead of organically modified montmorillonite in the preparation of the water-absorbing composite material.

[0078] Comparative Example 5: This comparative example is basically the same as Example 1, except that a resin material is used instead of the water-resistant composite material.

[0079] Test experiment:

[0080] The solder paste samples provided in Examples 1-3 and Comparative Examples 1-5 were placed at room temperature and 90% relative humidity for 4 hours, and then reflow soldered. The appearance of the solder joints after soldering was observed to see if solder splatter occurred. The results are shown in Table 1.

[0081] Table 1

[0082]

[0083]

[0084] As shown in Table 1, the solder paste of this invention does not easily absorb moisture from the air in a high humidity environment, thus avoiding the occurrence of solder splatter during soldering, resulting in bright and full solder joints with good spreadability, which can effectively improve yield and production efficiency.

[0085] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A lead-based solder paste that prevents solder from exploding, characterized in that, The leaded solder paste comprises the following components by weight: 8-12 parts flux paste, 5-10 parts water-resistant composite material, and 80-90 parts leaded solder powder; The flux paste comprises the following components by weight: 30-50 parts rosin, 30-50 parts solvent, 3-15 parts additives, 4-8 parts thixotropic agent, 5-10 parts organic acid, 1-5 parts halogen compound, and 0.5-5 parts antioxidant. The method for preparing the water-absorbing composite material is as follows: 1) Add phenol to the reactor, then add formaldehyde solution and oxalic acid solution, heat to 85-87℃ and react for 30-50 min. After the reaction is completed, dehydrate under vacuum, then cool to 80-83℃, add triethanolamine to adjust the pH to neutral, add epoxidized soybean oil, 1-methylimidazole and triethylamine, heat to 120-125℃ and keep the temperature for 1-3 h, then add 4,4'-diaminodiphenylmethane and continue to keep the temperature for 1-3 h to obtain resin material; 2) At room temperature, dissolve hexadecylpyridine chloride in deionized water and ultrasonically disperse for 15-30 min to obtain a hexadecylpyridine chloride modifier solution. Then dissolve montmorillonite in the hexadecylpyridine chloride modifier solution and magnetically stir at room temperature for 6-10 h to obtain a suspension. 3) Sodium dodecylbenzenesulfonate was dissolved in deionized water and ultrasonically dispersed to obtain a sodium dodecylbenzenesulfonate modifier solution. This solution was then added to the suspension. Under magnetic stirring, hydrochloric acid solution was added to adjust the pH to 5.0-5.

5. The solution was then heated and stirred in a water bath at 60-65℃ for 3-5 hours and allowed to stand for aging for 15-20 hours to obtain the product. After centrifugation, washing, drying, and grinding into powder, the organic modified montmorillonite was obtained. 4) Add the organically modified montmorillonite to deionized water and stir at 70-75℃ for 1-3 hours. Then add sodium dodecyl sulfate and continue stirring for 1-2 hours. Next, add methyl methacrylate and stir for 30-50 minutes. Then raise the temperature to 86-88℃ and slowly add ammonium persulfate. Continue stirring and react for 8-12 hours. After the reaction is complete, cool to room temperature, extract with acetone, precipitate with ethanol, wash repeatedly with deionized water, and dry to obtain the montmorillonite composite material. 5) Cool the resin material to 90-95℃, add toluene, mix thoroughly, and continue cooling to 50-55℃. Then add a mixture of toluene and methanol, mix well, and add hexamethylenetetramine to obtain a resin solution. Add montmorillonite composite material to the resin solution, stir and disperse thoroughly, centrifuge, and after curing, the water-resistant composite material can be obtained.

2. The lead-based solder paste for preventing solder blasting according to claim 1, characterized in that, The rosin is composed of KE-604, AX-E and CH-60 rosin in a mass ratio of 1:1:(0.2-0.5); The solvent is at least one of diethylene glycol dibutyl ether and tripropylene glycol butyl ether; The additive is at least one of polyisobutylene 300R and dimer acid; The thixotropic agent is at least one of hydrogenated castor oil and ethylene bis-stearamide.

3. The lead-based solder paste for preventing solder blasting according to claim 1, characterized in that, The organic acid is at least one of adipic acid, octanoic acid, sebacic acid, tetracosic acid, and dodecanoic acid; The halogen compound is at least one of dibromobutenediol and diphenylguanidine hydrobromide; The antioxidant is at least one of antioxidant 245 and antioxidant 1010.

4. The lead-based solder paste for preventing solder blasting according to claim 1, characterized in that, In step 1), the mass ratio of phenol, formaldehyde solution, oxalic acid solution, epoxidized soybean oil, 1-methylimidazole, triethylamine, and 4,4'-diaminodiphenylmethane is (100-150):(85-100):(3-6):(15-20):(1-2):(0.8-1.3):(2-5). The concentration of the formaldehyde solution is 35-37 wt%. The concentration of the oxalic acid solution is 50-53 wt%.

5. The lead-based solder paste for preventing solder blasting according to claim 1, characterized in that, In step 2), the ratio of hexadecyl chloride, deionized water, and montmorillonite in the suspension is (1-2) g: (50-80) mL: (2-5) g.

6. The lead-based solder paste for preventing solder blasting according to claim 1, characterized in that, In step 3), the ratio of sodium dodecylbenzenesulfonate, deionized water, and suspension is (0.5-1.3) g : (20-50) mL : (50-80) mL; The concentration of the hydrochloric acid solution is 0.1-0.3 mol / L.

7. The lead-based solder paste for preventing solder blasting according to claim 1, characterized in that, In step 4), the ratio of the amount of organic modified montmorillonite, deionized water, sodium dodecyl sulfate, methyl methacrylate and ammonium persulfate is (0.5-1.0) g : (300-400) mL : (1.2-1.8) g : (20-26) mL : (0.2-0.5) g.

8. The lead-based solder paste for preventing solder blasting according to claim 1, characterized in that, In step 5), the mass ratio of the resin material, toluene, mixture, hexamethylenetetramine, and montmorillonite composite material is (50-80):(5-10):(10-16):(2-5):(15-20). The mixture is composed of toluene and methanol in a volume ratio of 1:(0.5-0.8).

9. A method for preparing a leaded solder paste with anti-explosion properties according to any one of claims 1-8, characterized in that, Specifically, the steps include the following: 1) Prepare each component according to the weight proportions. Heat the rosin, solvent, additives, and thixotropic agent together to 150-156℃. After the system is dissolved and mixed evenly, the temperature is reduced to 130-135℃. Add the organic acid, halogen compound, and antioxidant. After it is completely dissolved, continue stirring for 2-6 minutes to mix it evenly. Transfer the evenly mixed material to a sealed beaker and cool it in ice water for 1-2 hours. Take it out and return it to room temperature. Grind it 1-2 times to obtain the flux. 2) Mix the flux, water-resistant composite material and leaded solder powder, and stir until the mixture is uniform to obtain solder paste.

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