Environment-friendly flux material and preparation method thereof

Abstract

This invention relates to the field of flux technology, and more particularly to an environmentally friendly flux material and its preparation method. The aforementioned environmentally friendly flux material comprises, by weight, the following raw materials: 1-3 parts polymeric rosin, 1-2 parts carboxyl-terminated polyamide amine, 1-3 parts hydrogenated rosin glycerol ester, 3-5 parts alicyclic epoxy acrylate, 0.01-0.3 parts 4,4'-methylenebis(cyclohexylamine), 0.5-1 parts nano-silica, 1-3 parts organic acid activator, 0.5-1 part corrosion inhibitor, 1-2 parts surfactant, 1-2 parts film-forming agent, 5-10 parts ester solvent, 1-5 parts alcohol solvent, and 5-10 parts water. This invention maintains excellent performance at lead-free soldering temperatures, meeting the venting requirements of high-density circuit boards, ensuring uniform distribution of flux residues, and achieving performance optimization through component interaction. The preparation process is simple.

Description

Technical Field

[0001] This invention relates to the field of flux technology, and in particular to an environmentally friendly flux material and its preparation method. Background Technology

[0002] With the rapid development of the electronics industry, electronic products are increasingly becoming thinner, lighter, miniaturized, and more portable, driving the process of circuit board refinement and cost reduction. In communication equipment assembly, the integration of components and electromagnetic shielding has become mainstream, requiring protective covers to be equipped with more vents to ensure the discharge of flux fumes.

[0003] Soldering is a core process in the electronics industry. Flux improves soldering quality by removing oxides from the surface of the workpiece and promoting solder diffusion and adhesion. Currently, the performance of flux directly determines the reliability of electronic products, and its importance is becoming increasingly prominent, especially in lightweight, miniaturized, and high-density applications.

[0004] Traditional fluxes contain large amounts of halogens, which not only damage the atmosphere and cause photochemical smog, endangering human health, but also corrode equipment and lead to decreased product stability due to moisture absorption, resulting in failures such as short circuits or open circuits. Furthermore, existing fluxes are inadequate in terms of wetting and spreading properties, oxidation resistance, and stability. Poor wetting and spreading properties hinder uniform solder spread, affecting weld strength; insufficient oxidation resistance leads to a thicker oxide layer at the weld interface, reducing the conductivity and mechanical strength of the solder joint. These problems limit the use of fluxes in miniaturized and high-density electronic products.

[0005] Therefore, providing an environmentally friendly flux that combines wetting and spreading properties, oxidation resistance, and excellent stability to adapt to the application of miniaturized and high-density electronic products has excellent research prospects. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by proposing an environmentally friendly flux material and its preparation method.

[0007] An environmentally friendly flux material, the raw materials of which, by weight, include: 1-3 parts polymeric rosin, 1-2 parts carboxyl-terminated polyamide amine, 1-3 parts hydrogenated rosin glycerol ester, 3-5 parts alicyclic epoxy acrylate, 0.01-0.3 parts 4,4'-methylenebis(cyclohexylamine), 0.5-1 parts nano silica, 1-3 parts organic acid activator, 0.5-1 parts corrosion inhibitor, 1-2 parts surfactant, 1-2 parts film-forming agent, 5-10 parts ester solvent, 1-5 parts alcohol solvent, and 5-10 parts water.

[0008] Preferably, the organic acid surfactant is at least one of acrylic acid, L-malic acid, citric acid, and succinic acid.

[0009] Preferably, the corrosion inhibitor is at least one of benzoic acid, sodium benzoate, sorbic acid, sorbate, and tert-butylhydroquinone.

[0010] Preferably, the film-forming agent is maleic rosin resin.

[0011] Preferably, the surfactant is an alkylphenol polyoxyethylene ether.

[0012] Preferably, the ester solvent is ethyl acetate or / and butyl acetate.

[0013] Preferably, the alcohol solvent is at least one of methanol, ethanol, and propylene glycol.

[0014] The preparation method of the above-mentioned environmentally friendly flux material includes the following steps:

[0015] S1. Mix ester solvent, alcohol solvent, and water evenly, add polymerized rosin and carboxyl-terminated polyamide amine, stir at 50-70℃ for 10-30 min to obtain composite solvent;

[0016] S2. Mix hydrogenated rosin glycerol ester, alicyclic epoxy acrylate, and 4,4'-methylenebis(cyclohexylamine), stir at 120-130℃ for 20-30 min, reduce the temperature to 40-50℃, add nano-silica and mix, then add to the composite solvent and stir for 10-20 min to obtain the preform.

[0017] S3. Add organic acid activator, corrosion inhibitor, surfactant and film-forming agent to the pre-made material, stir at 40-50℃ for 10-30 minutes, let stand and filter.

[0018] Beneficial effects: This invention utilizes polymerized rosin to provide a hydrophobic long-chain structure, which is compounded with carboxyl-terminated polyamide amine. This not only significantly reduces the surface tension of the system, but also promotes the uniform spreading of solder on the metal surface. At the same time, it can limit the volatilization of activator molecules during the welding process, preventing their migration and causing short circuits. Furthermore, it enhances the bonding strength between the solder and the substrate through intermolecular forces, ensuring the mechanical reliability of the solder joint.

[0019] This invention employs hydrogenated rosin glycerol ester, alicyclic epoxy acrylate, and nano-silica to form a synergistic protective system. This system not only blocks the oxidation chain reaction through a free radical capture mechanism, but also utilizes the doping gaps of nano-silica to form a dense barrier on the metal surface, effectively delaying oxygen penetration. Combined with the coordination effect of organic acid activators and metal ions, the antioxidant protective layer is further strengthened. Under the combined effect, the product exhibits excellent antioxidant stability.

[0020] This invention avoids the environmental hazards of traditional fluxes and maintains excellent performance at lead-free soldering temperatures. It can meet the venting requirements of high-density circuit boards, ensure uniform distribution of flux residues, and provide reliable soldering protection for miniaturized electronic devices. Furthermore, it achieves performance optimization through the interaction of components, has a simple preparation process, and effectively solves the performance bottleneck of traditional fluxes in miniaturized and high-density electronic product applications, thus possessing the potential for large-scale application. Attached Figure Description

[0021] Figure 1 The graph shows a comparison of the flux spread rate and surface insulation resistance of the fluxes obtained in Example 5 and Comparative Examples 1-2.

[0022] Figure 2 This is a comparison chart of the wetting time and final wetting force of the fluxes obtained in Example 5 and Comparative Examples 1-2. Detailed Implementation

[0023] The present invention will be further explained below with reference to specific embodiments.

[0024] The following polymerized rosin was purchased from Jiangsu Moufeng Chemical Technology Co., Ltd., model AJ04, with a softening point (ring and ball method) of 135-145℃ and an acid value ≥140mg KOH / g. The following carboxyl-terminated polyamide amine (PAMAM G2-COOH) was purchased from Hangzhou Mouqiao Biotechnology Co., Ltd. The following hydrogenated rosin glycerol ester was purchased from Wuhan Mounuos Technology Co., Ltd. The following alicyclic epoxy acrylate was purchased from Jining Mouyi Chemical Co., Ltd. The following OP-10 was purchased from Jinan Mounuo Chemical Co., Ltd. The following maleic acid rosin resin was purchased from Guangzhou Moudi Gao Chemical Co., Ltd., with a softening point (ring and ball method) ≥140℃ and an acid value ≥160mg KOH / g.

[0025] Example 1: An environmentally friendly flux material, the raw materials of which include: 1g of polymeric rosin, 1g of carboxyl-terminated polyamide amine, 1g of hydrogenated rosin glycerol ester, 3g of alicyclic epoxy acrylate, 0.01g of 4,4'-methylenebis(cyclohexylamine), 0.5g of nano silica, 1g of acrylic acid, 0.5g of sodium benzoate, 1g of OP-10, 1g of maleic rosin resin, 6g of butyl acetate, 1g of methanol, and 5g of deionized water.

[0026] The preparation method of the above-mentioned environmentally friendly flux material includes the following steps:

[0027] S1. Mix butyl acetate, methanol, and deionized water evenly, add polymerized rosin and carboxyl-terminated polyamide amine, and stir at 50°C for 10 min to obtain a composite solvent.

[0028] S2. Mix hydrogenated rosin glycerol ester, alicyclic epoxy acrylate, and 4,4'-methylenebis(cyclohexylamine), stir at 120℃ for 20 min, cool to 40℃, add nano silica and mix, add to the composite solvent, stir at 100 r / min for 10 min to obtain the preform.

[0029] S3. Add acrylic acid, sodium benzoate, OP-10 and film-forming agent to the pre-mixed material, stir at 100 r / min for 10 min, stirring temperature is 40℃, and let stand and filter.

[0030] Example 2: An environmentally friendly flux material, the raw materials of which include: 3g of polymeric rosin, 2g of carboxyl-terminated polyamide amine, 3g of hydrogenated rosin glycerol ester, 5g of alicyclic epoxy acrylate, 0.3g of 4,4'-methylenebis(cyclohexylamine), 1g of nano silica, 3g of succinic acid, 1g of sodium benzoate, 2g of OP-10, 2g of maleic rosin resin, 5g of butyl acetate, 2g of propylene glycol, and 6g of deionized water.

[0031] The preparation method of the above-mentioned environmentally friendly flux material includes the following steps:

[0032] S1. Mix butyl acetate, propylene glycol and deionized water evenly, add polymerized rosin and carboxyl-terminated polyamide amine, and stir at 70°C for 30 min to obtain a composite solvent.

[0033] S2. Mix hydrogenated rosin glycerol ester, alicyclic epoxy acrylate, and 4,4'-methylenebis(cyclohexylamine), stir at 130℃ for 30 min, cool to 50℃, add nano silica and mix, add to the composite solvent, stir at 300 r / min for 20 min to obtain the preform.

[0034] S3. Add succinic acid, sodium benzoate, OP-10 and film-forming agent to the pre-mixed material, stir at 300 r / min for 30 min, stirring temperature is 50℃, and then let stand and filter.

[0035] Example 3: An environmentally friendly flux material, the raw materials of which include: 1.5g of polymeric rosin, 1.7g of carboxyl-terminated polyamide amine, 1.5g of hydrogenated rosin glycerol ester, 4.5g of alicyclic epoxy acrylate, 0.05g of 4,4'-methylenebis(cyclohexylamine), 0.9g of nano silica, 1.5g of citric acid, 0.9g of potassium sorbate, 1.2g of OP-10, 1.7g of maleic rosin resin, 10g of ethyl acetate, 5g of ethanol, and 10g of deionized water.

[0036] The preparation method of the above-mentioned environmentally friendly flux material includes the following steps:

[0037] S1. Mix ethyl acetate, ethanol and deionized water evenly, add polymerized rosin and carboxyl-terminated polyamide amine, and stir at 65℃ for 15 min to obtain a composite solvent.

[0038] S2. Mix hydrogenated rosin glycerol ester, alicyclic epoxy acrylate, and 4,4'-methylenebis(cyclohexylamine), stir at 128℃ for 22 min, cool to 47℃, add nano silica and mix, add to the composite solvent, stir at 150 r / min for 18 min to obtain the preform.

[0039] S3. Add citric acid, potassium sorbate, OP-10 and film-forming agent to the pre-mixed material, stir at 150 r / min for 25 min, stirring temperature is 43℃, and then let stand and filter.

[0040] Example 4: An environmentally friendly flux material, the raw materials of which include: 2.5g of polymeric rosin, 1.3g of carboxyl-terminated polyamide amine, 2.5g of hydrogenated rosin glycerol ester, 3.5g of alicyclic epoxy acrylate, 0.25g of 4,4'-methylenebis(cyclohexylamine), 0.7g of nano silica, 2.5g of L-malic acid, 0.7g of potassium sorbate, 1.8g of OP-10, 1.3g of maleic rosin resin, 7g of ethyl acetate, 4g of methanol, and 8g of deionized water.

[0041] The preparation method of the above-mentioned environmentally friendly flux material includes the following steps:

[0042] S1. Mix ethyl acetate, methanol, and deionized water evenly, add polymerized rosin and carboxyl-terminated polyamide amine, and stir at 55°C for 25 min to obtain a composite solvent.

[0043] S2. Mix hydrogenated rosin glycerol ester, alicyclic epoxy acrylate, and 4,4'-methylenebis(cyclohexylamine), stir at 122℃ for 28 min, cool to 43℃, add nano silica and mix, add to the composite solvent, stir at 250 r / min for 12 min to obtain the preform.

[0044] S3. Add L-malic acid, potassium sorbate, OP-10, and film-forming agent to the pre-mixed material, stir at 250 r / min for 15 min, and stir at 47℃. Let stand and filter.

[0045] Example 5: An environmentally friendly flux material, the raw materials of which include: 2g of polymeric rosin, 1.5g of carboxyl-terminated polyamide amine, 2g of hydrogenated rosin glycerol ester, 4g of alicyclic epoxy acrylate, 0.2g of 4,4'-methylenebis(cyclohexylamine), 0.8g of nano-silica, 2g of citric acid, 0.8g of tert-butylhydroquinone, 1.5g of OP-10, 1.5g of maleic rosin resin, 8g of ethyl acetate, 1g of ethanol, and 10g of deionized water.

[0046] The preparation method of the above-mentioned environmentally friendly flux material includes the following steps:

[0047] S1. Mix ethyl acetate, ethanol and deionized water evenly, add polymerized rosin and carboxyl-terminated polyamide amine, and stir at 60℃ for 20 min to obtain a composite solvent.

[0048] S2. Mix hydrogenated rosin glycerol ester, alicyclic epoxy acrylate, and 4,4'-methylenebis(cyclohexylamine), stir at 125℃ for 25 min, cool to 45℃, add nano silica and mix, add to the composite solvent, stir at 200 r / min for 15 min to obtain the preform.

[0049] S3. Add citric acid, tert-butylhydroquinone, OP-10, and film-forming agent to the pre-mixed material, stir at 200 r / min for 20 min, and stir at 45℃. Let stand and filter.

[0050] Comparative Example 1: An environmentally friendly flux material, the raw materials of which include: 3.5g of polymeric rosin, 2g of hydrogenated rosin glycerol ester, 4g of alicyclic epoxy acrylate, 0.2g of 4,4'-methylenebis(cyclohexylamine), 0.8g of nano silica, 2g of citric acid, 0.8g of tert-butylhydroquinone, 1.5g of OP-10, 1.5g of maleic rosin resin, 8g of ethyl acetate, 1g of ethanol, and 10g of deionized water.

[0051] The preparation method of the above-mentioned environmentally friendly flux material includes the following steps:

[0052] S1. Mix ethyl acetate, ethanol and deionized water evenly, add polymerized rosin, and stir at 60℃ for 20 min to obtain a composite solvent.

[0053] S2. Mix hydrogenated rosin glycerol ester, alicyclic epoxy acrylate, and 4,4'-methylenebis(cyclohexylamine), stir at 125℃ for 25 min, cool to 45℃, add nano silica and mix, add to the composite solvent, stir at 200 r / min for 15 min to obtain the preform.

[0054] S3. Add citric acid, tert-butylhydroquinone, OP-10, and film-forming agent to the pre-mixed material, stir at 200 r / min for 20 min, and stir at 45℃. Let stand and filter.

[0055] Comparative Example 2: An environmentally friendly flux material, the raw materials of which include: 2g of polymeric rosin, 1.5g of carboxyl-terminated polyamide amine, 2g of hydrogenated rosin glycerol ester, 4g of alicyclic epoxy acrylate, 0.8g of nano silica, 2g of citric acid, 0.8g of tert-butylhydroquinone, 1.5g of OP-10, 1.5g of maleic rosin resin, 8g of ethyl acetate, 1g of ethanol, and 10g of deionized water.

[0056] The preparation method of the above-mentioned environmentally friendly flux material includes the following steps:

[0057] S1. Mix ethyl acetate, ethanol and deionized water evenly, add polymerized rosin and carboxyl-terminated polyamide amine, and stir at 60℃ for 20 min to obtain a composite solvent.

[0058] S2. Mix hydrogenated rosin glycerol ester and alicyclic epoxy acrylate, stir at 125℃ for 25 min, cool to 45℃, add nano silica and mix, add to composite solvent, stir at 200 r / min for 15 min to obtain preform.

[0059] S3. Add citric acid, tert-butylhydroquinone, OP-10, and film-forming agent to the pre-mixed material, stir at 200 r / min for 20 min, and stir at 45℃. Let stand and filter.

[0060] The spread rate and surface insulation resistance of the fluxes obtained in Example 5 and Comparative Examples 1-2 were measured with reference to GB / T 9491-2021 "Fluents for Soldering".

[0061] like Figure 1 As shown, the flux obtained in Example 5 has the highest spread rate and surface insulation resistance, which are significantly better than those of Comparative Examples 1-2.

[0062] The wetting time and final wetting force of the fluxes obtained in Example 5 and Comparative Examples 1-2 were determined using a solderability tester in accordance with GB / T 9491-2021 "Fluents for Soldering".

[0063] The final wetting force is the final stable value of the wetting force (acting force) in the test procedure of 6.9.2.4 of the above standard.

[0064] like Figure 2 As shown, the flux obtained in Example 5 had the shortest wetting time and the highest final wetting force, which was significantly better than that of Comparative Examples 1-2.

[0065] The reason for the above results is that this invention utilizes polymerized rosin to provide a hydrophobic long-chain structure, which, when combined with carboxyl-terminated polyamide amine, not only significantly reduces the surface tension of the system but also promotes the uniform spreading of solder on the metal surface. Simultaneously, during the soldering process, it can encapsulate activator molecules, preventing their migration and short circuits. Furthermore, it enhances the bonding strength between the solder and the substrate through intermolecular forces, ensuring the mechanical reliability of the solder joint. Furthermore, this invention employs hydrogenated rosin glycerol ester, alicyclic epoxy acrylate, and nano-silica to form a synergistic protective system. This system not only blocks the oxidation chain reaction through a free radical capture mechanism but also utilizes the doping gaps of nano-silica to form a dense barrier on the metal surface, effectively delaying oxygen penetration. Combined with the coordination effect of organic acid activators and metal ions, this further strengthens the antioxidant protective layer. The combined effect results in excellent antioxidant stability of the product.

[0066] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An environmentally friendly flux material, characterized in that, The raw materials, by weight, include: 1-3 parts polymerized rosin, 1-2 parts carboxyl-terminated polyamide amine, 1-3 parts hydrogenated rosin glycerol ester, 3-5 parts alicyclic epoxy acrylate, 0.01-0.3 parts 4,4'-methylenebis(cyclohexylamine), 0.5-1 parts nano silica, 1-3 parts organic acid surfactant, 0.5-1 parts corrosion inhibitor, 1-2 parts surfactant, 1-2 parts film-forming agent, 5-10 parts ester solvent, 1-5 parts alcohol solvent, and 5-10 parts water.

2. The environmentally friendly flux material according to claim 1, characterized in that, The organic acid surfactant is at least one of acrylic acid, L-malic acid, citric acid, and succinic acid.

3. The environmentally friendly flux material according to claim 1, characterized in that, The corrosion inhibitor is at least one of benzoic acid, sodium benzoate salts, sorbic acid, sorbate salts, and tert-butylhydroquinone.

4. The environmentally friendly flux material according to claim 1, characterized in that, The film-forming agent is maleic rosin resin.

5. The environmentally friendly flux material according to claim 1, characterized in that, The surfactant is alkylphenol polyoxyethylene ether.

6. The environmentally friendly flux material according to claim 1, characterized in that, The ester solvent is ethyl acetate and / or butyl acetate.

7. The environmentally friendly flux material according to claim 1, characterized in that, The alcohol solvent is at least one of methanol, ethanol, and propylene glycol.

8. A method for preparing an environmentally friendly flux material as described in any one of claims 1-7, characterized in that, Includes the following steps: S1. Mix ester solvent, alcohol solvent, and water evenly, add polymerized rosin and carboxyl-terminated polyamide amine, stir at 50-70℃ for 10-30 min to obtain composite solvent; S2. Mix hydrogenated rosin glycerol ester, alicyclic epoxy acrylate, and 4,4'-methylenebis(cyclohexylamine), stir at 120-130℃ for 20-30 min, reduce the temperature to 40-50℃, add nano-silica and mix, then add to the composite solvent and stir for 10-20 min to obtain the preform. S3. Add organic acid activator, corrosion inhibitor, surfactant and film-forming agent to the pre-made material, stir at 40-50℃ for 10-30 minutes, let stand and filter.

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