A solder paste with high-temperature resistance to post-soldering residue and its preparation method

Abstract

This application discloses a solder paste with high-temperature resistant post-soldering residue and its preparation method. The solder paste comprises solder and flux in a weight ratio of (8-9):(1-2). The solder comprises a tin-bismuth alloy and halloysite nanotubes modified with a titanate coupling agent. Based on the flux, the flux comprises the following raw materials in parts by weight: 35-65 parts composite rosin; 35-55 parts solvent; 5-15 parts tartaric acid; 5-10 parts thickener; 1-3 parts corrosion inhibitor; 2-4 parts antioxidant; and 2-3 parts oleyl alcohol polyoxyethylene ether. The high-temperature resistant post-soldering residue solder paste provided by this application has the advantages of high temperature resistance, low spatter, and good wettability. Furthermore, the soldering effect is hard and firm, with full and bright solder joints. In addition, the preparation method provided by this application has the advantages of simplicity, ease of operation, and suitability for large-scale production and application.

Description

Technical Field

[0001] This application relates to the field of solder materials technology, and in particular to a solder paste with high-temperature resistance to post-soldering residue and its preparation method. Background Technology

[0002] Solder paste is widely used in the electronics manufacturing industry and is an indispensable soldering material in SMT processes. However, existing solder pastes often suffer from problems such as poor heat resistance, splattering, and poor wetting properties during high-temperature soldering. These problems seriously affect soldering quality and product performance, especially in high-energy-density soldering scenarios. Therefore, there is an urgent need to develop a solder paste with excellent high-temperature resistance and its corresponding preparation process to overcome the shortcomings of existing technologies. Summary of the Invention

[0003] In order to solve at least one of the above-mentioned technical problems and to develop a solder paste with high temperature resistance, low spatter and good wettability, this application provides a solder paste with high temperature resistance and post-soldering residue and its preparation method.

[0004] In a first aspect, this application provides a solder paste with high-temperature resistance to post-soldering residue, the solder paste comprising solder and flux in a weight ratio of (8-9):(1-2);

[0005] The solder comprises tin-bismuth series alloys and titanate coupling agent modified halloysite nanotubes;

[0006] Based on the solder paste, the solder paste comprises the following raw materials in parts by weight:

[0007] 35-65 parts of compound rosin;

[0008] Solvent 35-55 parts;

[0009] Tartaric acid 5-15 parts;

[0010] Thickener 5-10 parts;

[0011] 1-3 parts corrosion inhibitor;

[0012] Antioxidant 2-4 parts;

[0013] 4-7 parts hydrogenated castor oil;

[0014] 2-3 parts of oleyl alcohol polyoxyethylene ether.

[0015] By adopting the above technical solution, this application provides a novel solder paste designed to solve the technical problems existing in current solder pastes during high-temperature soldering, such as poor high-temperature resistance, easy spattering, and poor wettability. This solder paste consists of solder and flux. The solder uses a tin-bismuth alloy, which has a high melting point and good heat resistance. Simultaneously, halloysite nanotubes modified with titanate coupling agent are added, which not only improves the fluidity of the solder paste but also enhances its wettability and heat resistance. The flux portion contains multiple components such as composite rosin, solvent, tartaric acid, thickener, corrosion inhibitor, antioxidant, hydrogenated castor oil, and oleyl alcohol polyoxyethylene ether. These components, used in specific proportions, effectively reduce spattering during soldering, improve the reliability of solder joints, and maintain good soldering results even under high-temperature conditions. The solder paste provided by this application can significantly improve soldering quality and product performance, and is particularly suitable for high-energy-density soldering scenarios. It can effectively cope with the challenges of high-temperature environments, ensuring the consistency and reliability of soldering. Specifically, the solder paste provided in this application consists of solder and flux, wherein the weight ratio of solder to flux is (8-9):(1-2). The solder portion contains a tin-bismuth alloy and halloysite nanotubes modified with a titanate coupling agent. This application utilizes halloysite nanotubes to increase the stability of the solder and improve the formation of solder joints. Furthermore, the flux includes multiple components, among which composite rosin, as the main active ingredient, can remove oxides from the metal surface, promote solder flow, and improve wettability. A solvent is used to dissolve other components in the flux, ensuring that the flux is evenly distributed in the solder paste. Tartaric acid, as an acidic substance, helps remove the oxide layer on the metal surface, improving soldering quality.

[0016] Thickeners are used to adjust the viscosity of solder paste and prevent it from collapsing during printing or placement. Corrosion inhibitors reduce corrosion of the metal substrate during soldering and protect the substrate from damage. Antioxidants prevent flux from failing due to oxidation during storage and use. Hydrogenated castor oil improves the lubricity and stability of the solder paste and reduces spatter during soldering. Oil-based polyoxyethylene ethers, as surfactants, further improve the wettability of the solder paste and promote good bonding between the solder and the metal surface. In summary, by optimizing the proportions of each component and selecting appropriate additives, the solder paste proposed in this application can maintain good soldering performance at high temperatures, reduce spatter, and improve wettability, thereby effectively solving the problems in the prior art.

[0017] Optionally, the composite rosin is prepared by compounding water-white rosin and polymerized rosin in a weight ratio of (3-5):1.

[0018] By adopting the above technical solution, the combined use of water-white rosin and polymerized rosin can enhance the deoxidation ability and wettability of the flux while maintaining good soldering performance.

[0019] Optionally, the preparation method of the titanate coupling agent modified halloysite nanotubes includes the following steps: adding halloysite nanotubes to an ethanol solvent, adding a titanate coupling agent under stirring, reacting under a nitrogen atmosphere and at 70-80℃ for 12-24 hours, and then filtering, washing, and drying to obtain the titanate coupling agent modified halloysite nanotubes.

[0020] By adopting the above technical solution, this application provides a method for preparing halloysite nanotubes modified with titanate coupling agent, aiming to improve the performance problems of solder paste in high-temperature soldering processes, such as poor high-temperature resistance, easy spattering, and poor wettability. Specifically, the method involves adding halloysite nanotubes to an ethanol solvent, adding a titanate coupling agent under stirring, and reacting under a nitrogen atmosphere at 70-80°C for 12-24 hours. Following filtration, washing, and drying, the titanate coupling agent-modified halloysite nanotubes are finally obtained. This modified halloysite nanotube can significantly improve the wettability of solder paste, enhance its stability under high-temperature conditions, and reduce spattering during soldering. By adding this modified halloysite nanotube to solder paste, the overall performance of the solder paste can be improved, especially exhibiting better soldering quality and reliability in high-energy-density soldering scenarios, thus solving the technical problems existing in current solder pastes during high-temperature soldering.

[0021] Optionally, the solvent is prepared by compounding tetraethylene glycol methyl ether and propylene glycol diacetate in a weight ratio of 5:(4-6).

[0022] By adopting the above technical solution, the solvent is prepared by compounding tetraethylene glycol methyl ether and propylene glycol diacetate in a weight ratio of 5:(4-6). This compounded solvent has a high boiling point and good solubility, which can improve the rheological properties and stability of solder paste, and at the same time help to improve the heat resistance of solder paste under high temperature conditions.

[0023] Optionally, the solder is selected from Sn63Pb37.

[0024] Optionally, the halloysite nanotubes comprise (0.6-0.8) wt% of the solder.

[0025] Optionally, the mass ratio of the titanate coupling agent to halloysite nanotubes is (0.2-0.3):1.

[0026] Optionally, the thickener is selected from ethylene bis-stearamide.

[0027] Optionally, the corrosion inhibitor is selected from benzotriazole.

[0028] Secondly, this application provides a method for preparing solder paste with high-temperature resistance to post-soldering residue. The preparation method includes the following steps: adding composite rosin, solvent, tartaric acid, oleyl alcohol polyoxyethylene ether, corrosion inhibitor, antioxidant, and hydrogenated castor oil into a container, stirring at 90-110°C until the solution becomes transparent; raising the temperature to 130-150°C, adding solder and thickener into the container, and stirring for 5-7 minutes to obtain the high-temperature resistance to post-soldering residue solder paste.

[0029] By adopting the above technical solution, the preparation method provided in this application has the advantages of being simple, easy to operate, and conducive to large-scale production and application.

[0030] In summary, the present invention has at least one of the following beneficial technical effects:

[0031] 1. This application provides a novel solder paste designed to address the technical problems of existing solder pastes during high-temperature soldering, such as poor heat resistance, splattering, and poor wetting properties. The solder paste consists of solder and flux. The solder uses a tin-bismuth alloy, which has a high melting point and good heat resistance. Additionally, halloysite nanotubes modified with a titanate coupling agent are added, which not only improves the fluidity of the solder paste but also enhances its wetting and heat resistance. The flux portion contains a variety of components, including composite rosin, solvent, tartaric acid, thickener, corrosion inhibitor, antioxidant, hydrogenated castor oil, and oleyl alcohol polyoxyethylene ether. These components, used in specific proportions, effectively reduce spattering during soldering, improve the reliability of solder joints, and maintain good soldering performance even at high temperatures. The solder paste provided by this application significantly improves soldering quality and product performance, and is particularly suitable for high-energy-density soldering scenarios. It effectively addresses the challenges of high-temperature environments, ensuring consistent and reliable soldering. Specifically, the solder paste provided in this application consists of solder and flux, wherein the weight ratio of solder to flux is (8-9):(1-2). The solder portion contains tin-bismuth alloys and halloysite nanotubes modified with titanate coupling agents. This application utilizes halloysite nanotubes to increase the stability of the solder and improve the formation of solder joints. Furthermore, the flux includes multiple components, among which composite rosin, as the main active ingredient, can remove oxides from metal surfaces, promote solder flow, and improve wettability. Solvents are used to dissolve other components in the flux, ensuring uniform distribution of the flux within the solder paste. Tartaric acid, as an acidic substance, helps remove oxide layers from metal surfaces, improving soldering quality. Thickeners are used to adjust the viscosity of the solder paste, preventing collapse during printing or placement. Corrosion inhibitors reduce corrosion of the metal substrate during soldering, protecting the substrate from damage. Antioxidants prevent the flux from failing due to oxidation during storage and use. Hydrogenated castor oil improves the lubricity and stability of the solder paste, reducing spatter during soldering. Oleyl alcohol polyoxyethylene ether, as a surfactant, can further improve the wettability of solder paste and promote good bonding between the solder and the metal surface. In summary, by optimizing the proportions of each component and selecting appropriate additives, the solder paste proposed in this application can maintain good soldering performance at high temperatures, reduce spatter, and improve wettability, thereby effectively solving the problems in the prior art.

[0032] 2. This application provides a method for preparing halloysite nanotubes modified with a titanate coupling agent, aiming to improve the performance problems of solder paste during high-temperature soldering, such as poor high-temperature resistance, easy spattering, and poor wettability. Specifically, the method involves adding halloysite nanotubes to an ethanol solvent, adding a titanate coupling agent under stirring, and reacting under a nitrogen atmosphere at 70-80°C for 12-24 hours. Following filtration, washing, and drying, the titanate coupling agent-modified halloysite nanotubes are finally obtained. This modified halloysite nanotube can significantly improve the wettability of solder paste, enhance its stability under high-temperature conditions, and reduce spattering during soldering. By adding this modified halloysite nanotube to solder paste, the overall performance of the solder paste can be improved, especially exhibiting better soldering quality and reliability in high-energy-density soldering scenarios, thus solving the technical problems existing in current solder pastes during high-temperature soldering.

[0033] 3. The preparation method provided in this application has the advantages of being simple, easy to operate, and conducive to large-scale production and application. Detailed Implementation

[0034] The present application will be further described in detail below with reference to the embodiments.

[0035] Tartaric acid: Langfang Qianyao Technology Co., Ltd., content 99%.

[0036] Hydrogenated castor oil: CAS No. 8001-78-3, purity 99%.

[0037] Oleyl alcohol polyoxyethylene ether: CAS No. 9004-98-2, content 99%.

[0038] Water-white rosin: Jining Tangyi Chemical Co., Ltd., water-white hydrogenated rosin, content 98%.

[0039] Polymerized rosin: Jining Tangyi Chemical Co., Ltd., with an effective ingredient content of 95%.

[0040] Tetraethylene glycol methyl ether: CAS No. 23783-42-8, Lierji Industrial (Shanghai) Co., Ltd.

[0041] Propylene glycol diacetate: Shandong Jibei New Materials Co., Ltd., CAS No. 623-84-7, content 99%.

[0042] Ethylene bis-stearamide: Zhonghe Chemical (Shandong) Co., Ltd., model ZH-6598.

[0043] Benzotriazole: CAS No. 95-14-7, purity 99%. Specific Implementation

[0045] Example 1

[0046] This embodiment provides a solder paste with high temperature resistance to post-soldering residue. The solder paste includes solder and flux in a weight ratio of 9:1.

[0047] The solder consists of tin-bismuth alloys and titanate coupling agent-modified halloysite nanotubes (haloysite nanotubes account for 0.7 wt% of the solder).

[0048] Based on solder paste, the solder paste comprises the following raw materials in parts by weight:

[0049] The compound rosin consists of 55 parts of composite rosin, 35 parts of solvent, 5 parts of tartaric acid, 5 parts of thickener, 1 part of corrosion inhibitor, 2 parts of antioxidant, 4 parts of hydrogenated castor oil, and 2 parts of oleyl alcohol polyoxyethylene ether. The composite rosin is prepared by compounding water-white rosin and polymerized rosin in a weight ratio of 4.5:1.

[0050] Halloysite nanotubes were added to an ethanol solvent, and a titanate coupling agent was added under stirring. The reaction was carried out at 80°C for 22 hours under a nitrogen atmosphere. After filtration, washing (three times with deionized water), and drying (at 50°C), titanate coupling agent-modified halloysite nanotubes were obtained. The mass ratio of titanate coupling agent to halloysite nanotubes was 0.25:1.

[0051] The solvent in this embodiment is prepared by compounding tetraethylene glycol methyl ether and propylene glycol diacetate in a weight ratio of 5:4.

[0052] The solder in this embodiment is selected from Sn63Pb37.

[0053] The antioxidant in this embodiment is butylated hydroxytoluene.

[0054] The corrosion inhibitor in this embodiment is benzotriazole.

[0055] The thickener used in this embodiment is ethylene bis-stearamide.

[0056] The method for preparing the high-temperature resistant solder paste residue after soldering in this embodiment includes the following steps:

[0057] The compound rosin, solvent, tartaric acid, oleyl alcohol polyoxyethylene ether, corrosion inhibitor, antioxidant, and hydrogenated castor oil are put into a container and stirred at 100°C until the solution becomes transparent. The temperature is raised to 145°C, and the solder and thickener are added into the container and stirred for 7 minutes to obtain the high-temperature resistant solder paste.

[0058] Example 2

[0059] The difference between this embodiment and Embodiment 1 is that, in preparing a solder paste with high-temperature resistant post-soldering residue, the total weight of the composite rosin is 55 parts; wherein, the weight ratio of water-white rosin to polymerized rosin is 3:1.

[0060] Example 3

[0061] The difference between this embodiment and Embodiment 1 is that, in preparing a solder paste with high-temperature resistance to post-soldering residue, the total weight of the composite rosin is 55 parts. The weight ratio of water-white rosin to polymerized rosin is 4:1.

[0062] Example 4

[0063] The difference between this embodiment and Embodiment 1 is that, in preparing a solder paste with high-temperature resistance to post-soldering residue, the total weight of the composite rosin is 55 parts. The weight ratio of water-based white rosin to polymerized rosin is 5:1.

[0064] Comparative Examples 1-3

[0065] Comparative Example 1

[0066] The difference between this comparative example and Example 1 is that, in preparing a solder paste with high-temperature resistant post-soldering residue, an equal amount of water-based rosin was used instead of polymerized rosin.

[0067] Comparative Example 2

[0068] The difference between this comparative example and Example 1 is that, in preparing a solder paste with high-temperature resistant post-soldering residue, an equal amount of polymeric rosin was used instead of water-based white rosin.

[0069] Comparative Example 3

[0070] The difference between this comparative example and Example 1 is that, in preparing a solder paste with high-temperature resistance to post-soldering residue, an equal amount of halloysite nanotubes were added to replace the titanate coupling agent to modify the halloysite nanotubes.

[0071] Experimental testing:

[0072] 1. Spread rate: The spread rate of solder paste was determined according to SJ / T11389-2019 "Methods for lead-free soldering flux". The test results are shown in Table 1.

[0073] 2. Solder balls: The solder balls after soldering were measured according to IPCJSTD005, and the test results are shown in Table 1.

[0074] 3. Wettability: The wettability of the solder paste after soldering was measured according to IPCJSTD005, and the test results are shown in Table 1.

[0075] Table 1 - Experimental test results of Examples 1-4 and Comparative Examples 1-3

[0076] Example Expansion rate (%) Tin beads (grade) Wettability (Grade) Example 1 87.9 2 2 Example 2 84.4 2 2 Example 3 86.2 2 2 Example 4 85.7 2 2 Comparative Example 1 80.3 3 3 Comparative Example 2 82.1 3 3 Comparative Example 3 63.2 3 4

[0077] Results Analysis: The difference between Examples 2-4 and Example 1 lies in the different weight ratios of water-based rosin and polymeric rosin used in preparing a solder paste with high-temperature resistance to post-soldering residue. Based on the experimental data in Table 1, the solder paste with high-temperature resistance to post-soldering residue exhibits better overall performance when the weight ratio of water-based rosin to polymeric rosin is 4.5:1. The difference between Comparative Example 1 and Example 1 lies in the use of an equal amount of water-based rosin instead of polymeric rosin in preparing a solder paste with high-temperature resistance to post-soldering residue. The difference between Comparative Example 2 and Example 1 lies in the use of an equal amount of polymeric rosin instead of water-based rosin in preparing a solder paste with high-temperature resistance to post-soldering residue. Based on the experimental data in Table 1, the simultaneous use of polymeric rosin and water-based rosin significantly improves the wetting properties and spread of the solder paste. The difference between Comparative Example 3 and Example 1 is that, in preparing a solder paste with high-temperature resistance to post-soldering residue, an equal amount of halloysite nanotubes were added instead of the titanate coupling agent to modify the halloysite nanotubes. According to the experimental data in Table 1, using halloysite nanotubes instead of the titanate coupling agent to modify the halloysite nanotubes affects the spread rate, wettability, and solder ball formation of the solder paste. This may be because the modified halloysite nanotubes significantly improve the wettability and spread rate of the solder paste and reduce solder ball formation. This is because the modification improves the interfacial compatibility between the halloysite nanotubes and the solder powder, thereby improving the overall performance of the solder paste.

[0078] In summary, through comparison of the examples and comparative examples, it can be concluded that a specific ratio of composite rosin and modified halloysite nanotubes has a significant effect on improving the overall performance of solder paste. These findings provide important guidance for the development of solder pastes with high temperature resistance, low spatter, and good wetting properties.

[0079] Examples 5-6

[0080] Example 5

[0081] The difference between this embodiment and Embodiment 1 is that, in preparing a solder paste with high-temperature resistance to post-soldering residue, the weight proportions of some components are changed. The differences are shown in Table 2.

[0082] Table 2 - Record of Differences Between Examples 5-6 and Example 1

[0083] Ingredients (per serving) Example 1 Example 5 Example 6 Compound rosin 35 58 65 solvent 35 47 55 tartaric acid 5 12 15 Thickener 5 8 10 corrosion inhibitor 1 2 3 antioxidants 2 3.5 4 Oleol polyoxyethylene ether 2 2.7 3 Hydrogenated castor oil 4 6 7

[0084] The experimental test results of Examples 5-6 are shown in Table 3.

[0085] Table 3 - Experimental Detection Results of Examples 5-6

[0086] Example Expansion rate (%) Tin beads (grade) Wettability (Grade) Example 1 87.9 2 2 Example 5 89.2 1 1 Example 6 88.3 2 2

[0087] Results Analysis: The difference between Examples 5-6 and Example 1 is that the weight proportions of some components are different when preparing a solder paste with high temperature resistance to post-soldering residue. According to the experimental test results in Table 3, the solder paste with high temperature resistance to post-soldering residue prepared in Example 5 has better overall performance.

[0088] Examples 7-8

[0089] Example 7

[0090] The difference between this embodiment and Example 5 is that the solvent in this embodiment is prepared by compounding tetraethylene glycol methyl ether and propylene glycol diacetate in a weight ratio of 5:5.5.

[0091] Example 8

[0092] The difference between this embodiment and Example 5 is that the solvent in this embodiment is prepared by compounding tetraethylene glycol methyl ether and propylene glycol diacetate in a weight ratio of 5:6.

[0093] The experimental test results of Examples 7-8 are shown in Table 4.

[0094] Table 4 - Experimental Detection Results of Examples 7-8

[0095] Example Expansion rate (%) Tin beads (grade) Wettability (Grade) Example 5 89.2 1 1 Example 7 91.2 1 1 Example 8 90.6 1 1

[0096] Results Analysis: The difference between Examples 7-8 and Example 5 is that the weight ratio of tetraethylene glycol methyl ether and propylene glycol diacetate is different when preparing solder paste with high temperature resistance and post-soldering residue. According to the experimental test data in Table 4, the solder paste with better overall performance is obtained when the weight ratio of tetraethylene glycol methyl ether and propylene glycol diacetate is 5:5.5.

[0097] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A solder paste with high-temperature resistance to post-soldering residue, characterized in that, The solder paste comprises solder and flux in a weight ratio of (8-9):(1-2); The solder comprises tin-bismuth series alloys and titanate coupling agent modified halloysite nanotubes; Based on the solder paste, the solder paste comprises the following raw materials in parts by weight: 35-65 parts of compound rosin; Solvent 35-55 parts; Tartaric acid 5-15 parts; Thickener 5-10 parts; 1-3 parts corrosion inhibitor; Antioxidant 2-4 parts; 4-7 parts hydrogenated castor oil; 2-3 parts of oleyl alcohol polyoxyethylene ether.

2. The solder paste with high-temperature resistance to post-soldering residue as described in claim 1, characterized in that, The composite rosin is prepared by compounding water-white rosin and polymerized rosin in a weight ratio of (3-5):

1.

3. The solder paste with high-temperature resistance to post-soldering residue according to claim 1, wherein the preparation method of the titanate coupling agent modified halloysite nanotubes comprises the following steps: Halloysite nanotubes were added to an ethanol solvent, and a titanate coupling agent was added under stirring. The mixture was reacted for 12-24 hours under a nitrogen atmosphere and at 70-80°C. After filtration, washing, and drying, the titanate coupling agent-modified halloysite nanotubes were obtained.

4. The solder paste with high-temperature resistance to post-soldering residue as described in claim 1, characterized in that, The solvent is prepared by compounding tetraethylene glycol methyl ether and propylene glycol diacetate in a weight ratio of 5:(4-6).

5. The solder paste with high-temperature resistance to post-soldering residue as described in claim 1, characterized in that, The titanate coupling agent modified halloysite nanotubes account for (0.6-0.8) wt% of the solder.

6. The solder paste with high-temperature resistance to post-soldering residue as described in claim 3, characterized in that, The mass ratio of the titanate coupling agent to halloysite nanotubes is (0.2-0.3):

1.

7. The solder paste with high-temperature resistance to post-soldering residue according to claim 1, characterized in that, The thickener is selected from ethylene bis-stearamide.

8. The solder paste with high-temperature resistance to post-soldering residue according to claim 1, characterized in that, The corrosion inhibitor is selected from benzotriazole.

9. A method for preparing solder paste with high-temperature resistant post-soldering residue as described in any one of claims 1-8, characterized in that, The preparation method includes the following steps: adding composite rosin, solvent, tartaric acid, oleyl alcohol polyoxyethylene ether, corrosion inhibitor, antioxidant, and hydrogenated castor oil into a container, stirring at 90-110℃ until the solution becomes transparent; raising the temperature to 130-150℃, adding solder and thickener into the container, and stirring for 5-7 minutes to obtain the high-temperature resistant solder paste.