Halogen-free low-spatter soldering agent for solder wire, method for producing the same, and solder wire

Abstract

This invention discloses a halogen-free, low-splatter solder wire flux and its preparation method, as well as the solder wire. The flux, by weight percentage, has the following raw material formulation: 88%–95% polymeric rosin, 4%–13% activator, and 0.2%–1.6% film-forming agent. The activator includes a main activator and auxiliary activators. Based on the total weight of the raw materials, the main activator is composed of 2%–5% dimethylolpropionic acid and 2%–5% maleic anhydride, while the auxiliary activator includes 0.1%–0.6% Triton X-100. The film-forming agent includes at least one of polyethylene glycol dimethacrylate and sodium carboxymethyl cellulose. The preparation method of this flux is simple, reasonable, and easy to operate. The resulting flux effectively suppresses spatter generation and exhibits excellent wetting properties and reliable soldering performance, thus well meeting market demands.

Description

Technical Field

[0001] This invention relates to the field of solder wire technology, and in particular to a halogen-free, low-splatter solder wire agent and its preparation method, as well as the solder wire itself. Background Technology

[0002] Soldering is a crucial step in the manufacturing process of electronic equipment. With the continuous advancement of electronic soldering technologies, such as high-frequency soldering and laser soldering, traditional solder wire is prone to spatter during the soldering process. This spatter includes splatter from the solder wire flux (specifically rosin-core flux) and fine solder balls. Spatter during soldering not only severely affects the soldering quality but also poses a risk of injury to operators. Therefore, there is an urgent need to provide a solder wire flux that can achieve low spatter during the soldering process.

[0003] In view of this, the present invention is hereby proposed. Summary of the Invention

[0004] To overcome the above-mentioned defects, the present invention provides a halogen-free low-splatter solder wire flux and its preparation method, as well as the solder wire. The preparation method of the flux is simple, reasonable and easy to operate, and the obtained flux can effectively suppress spatter generation and has excellent wetting properties and reliable soldering performance, which well meets market demand.

[0005] The technical solution adopted by this invention to solve its technical problem is: a halogen-free, low-splatter solder wire agent, which, by weight percentage, has the following raw material formula: 88%–95% polymeric rosin, 4%–13% activator, and 0.2%–1.6% film-forming agent; wherein, the activator includes a main activator and an auxiliary activator, and based on the total weight of the raw materials of the agent, the main activator is composed of 2%–5% dimethylolpropionic acid and 2%–5% maleic anhydride, and the auxiliary activator includes 0.1%–0.6% Triton X-100; The film-forming agent includes at least one of polyethylene glycol dimethacrylate and sodium carboxymethyl cellulose.

[0006] As a further improvement of the present invention, the polymeric rosin is polymeric rosin-140 with a softening point of 135℃~145℃.

[0007] As a further improvement of the present invention, based on the total weight of the raw materials of the pharmaceutical preparation, the auxiliary activator further includes 0.5% to 1.5% polyoxypropylene glycerol ether.

[0008] As a further improvement of the present invention, based on the total weight of the raw materials of the pharmaceutical agent, the film-forming agent is composed of 0.2% to 0.5% polyethylene glycol dimethacrylate and 0.1% to 1% sodium carboxymethyl cellulose; and the molecular weight of the polyethylene glycol dimethacrylate is 600.

[0009] This invention also provides a method for preparing a halogen-free, low-splatter solder wire flux, comprising the following steps: S1: Heat the polymerized rosin in the formula until it is completely melted, then add the auxiliary activator and polyethylene glycol dimethacrylate in the formula, and stir thoroughly to obtain the first mixture; S2: While stirring, cool the first mixture. After the first mixture cools to 120℃~130℃, add the formulated amount of main activator and sodium carboxymethyl cellulose, and stir thoroughly again to obtain the halogen-free low-splatter solder wire agent.

[0010] As a further improvement of the present invention, in S1 above, after obtaining the first mixture, the obtained first mixture needs to be continuously stirred, and the stirring speed is controlled at 50 to 60 rpm.

[0011] As a further improvement of the present invention, in S2 above, the stirring speed is also controlled at 50-60 rpm.

[0012] The present invention also provides a solder wire comprising a solder alloy and a halogen-free, low-splatter solder wire agent as described in the present invention. The solder wire is prepared by coating the agent onto the surface of the solder alloy through a coating process or an impregnation process; or, the solder wire is prepared by extruding the agent and the solder alloy together into an integral structure through an extrusion molding process.

[0013] The beneficial effects of this invention are: ① Through technological innovation, this invention has produced a reagent and solder wire that can effectively suppress spatter generation and has excellent wetting properties and reliable welding performance, thus well meeting market demands. ② The method for preparing the halogen-free, low-spatter solder wire reagent provided by this invention is simple, reasonable, and easy to operate, and the related raw materials are readily available, inexpensive, and more environmentally friendly. Detailed Implementation

[0014] The present invention will be further described in detail below with reference to specific embodiments, but the present invention is not limited to these embodiments.

[0015] This application discloses a halogen-free, low-splatter solder wire flux and its preparation method, as well as the solder wire itself. The preparation method of this solder wire flux is simple, reasonable, and easy to operate. The resulting flux effectively suppresses spatter and exhibits excellent wetting properties and reliable soldering performance, thus well meeting market demands. The main reason for this achievement lies in the optimized and innovative raw material formulation of the solder wire flux in this application. Specific details are as follows: I. The reagent for preparing the halogen-free, low-splatter solder wire described in this application:

[0016] Example 1:

[0017] This embodiment 1 provides a method for preparing a halogen-free, low-splatter solder wire flux, which mainly includes the following steps: S1: 88 kg of polymerized rosin-140 is placed in an electromagnetic heating boiler and heated to 145°C until completely melted. Then, 0.4 kg of Triton X-100, 1 kg of polyoxypropylene glycerol ether, and 0.5 kg of polyethylene glycol dimethacrylate (molecular weight 600) are added sequentially while stirring. The mixture is thoroughly stirred to obtain a first mixture. After obtaining the first mixture, it is necessary to continue stirring. In particular, the stirring speed in each stage of S1 is controlled at 50-60 rpm.

[0018] S2: The first mixture is cooled while being stirred. Understandably, the stirring speed is also controlled at 50-60 rpm. After the first mixture is cooled to 120℃-130℃ (preferably 125℃), 5Kg of dimethylolpropionic acid, 5Kg of maleic anhydride and 0.1Kg of sodium carboxymethyl cellulose are added to it in sequence, and the mixture is stirred thoroughly again to obtain the halogen-free low-splatter solder wire agent.

[0019] Additional notes: ① The molecular weight of the above-mentioned polyethylene glycol dimethacrylate is 600. It is understood that the above-mentioned polyethylene glycol dimethacrylate has 4 to 6 ethylene glycol units. This type of product belongs to the medium molecular weight category and is a viscous liquid. ② The solder wire flux prepared in this application can also be called a soldering flux.

[0020] Example 2:

[0021] This embodiment 2 also provides a method for preparing a halogen-free low-splatter solder wire agent. Compared with embodiment 1, the difference of embodiment 2 is that the agent raw material formula used in embodiment 2 is different from that in embodiment 1.

[0022] Specifically, the pharmaceutical raw material formula used in this Example 2 is as follows: 90 kg of polymeric rosin-140, 0.4 kg of Triton X-100, 0.8 kg of polyoxypropylene glycerol ether, 0.4 kg of polyethylene glycol dimethacrylate (molecular weight 600), 4 kg of dimethylolpropionic acid, 4 kg of maleic anhydride and 0.4 kg of sodium carboxymethyl cellulose.

[0023] Note: Apart from the differences mentioned above, the specific processing methods and parameters used in each step of this embodiment 2, such as heating temperature and stirring speed, are the same as those in embodiment 1; therefore, they will not be repeated here.

[0024] Example 3:

[0025] This embodiment 3 also provides a method for preparing a halogen-free low-splatter solder wire agent. Compared with embodiment 1, the difference of this embodiment 3 is that the agent raw material formula used in this embodiment 3 is different from that in embodiment 1.

[0026] Specifically, the pharmaceutical raw material formula used in this Example 3 is as follows: 91 kg of polymeric rosin-140, 0.6 kg of Triton X-100, 1.2 kg of polyoxypropylene glycerol ether, 0.4 kg of polyethylene glycol dimethacrylate (molecular weight 600), 3 kg of dimethylolpropionic acid, 3 kg of maleic anhydride and 0.8 kg of sodium carboxymethyl cellulose.

[0027] Note: Apart from the differences mentioned above, the specific processing methods and parameters used in each step of this embodiment 3, such as heating temperature and stirring speed, are the same as those in embodiment 1; therefore, they will not be repeated here.

[0028] Example 4:

[0029] This embodiment 4 also provides a method for preparing a halogen-free low-splatter solder wire agent. Compared with embodiment 1, the difference of embodiment 4 is that the agent raw material formula used in embodiment 4 is different from that in embodiment 1.

[0030] Specifically, the pharmaceutical raw material formula used in Example 4 is as follows: 95 kg of polymeric rosin-140, 0.2 kg of Triton X-100, 0.5 kg of polyoxypropylene glycerol ether, 0.2 kg of polyethylene glycol dimethacrylate (molecular weight 600), 2 kg of dimethylolpropionic acid, 2 kg of maleic anhydride and 0.1 kg of sodium carboxymethyl cellulose.

[0031] Note: Apart from the differences mentioned above, the specific processing methods and parameters used in each step of this embodiment 4, such as heating temperature and stirring speed, are the same as those in embodiment 1; therefore, they will not be repeated here.

[0032] II. Fabrication of the solder wire described in this application:

[0033] Example 5:

[0034] This embodiment 5 provides a solder wire, the manufacturing method of which is as follows: Step 1): Provide a solder alloy and a flux for solder wire prepared according to Example 1 above, wherein the weight ratio of the solder alloy to the flux is 98:2.

[0035] Note: Regarding the solder alloy, this application does not impose any restrictions on its specific composition, which can be determined according to product requirements. For example, it can be, but is not limited to, tin-lead alloy, lead-free alloy, or medium-low temperature alloy. Among them, the tin-lead alloy can be further preferably 63Sn37Pb, 60Sn40Pb, or 62Sn36Pb2.0Ag, etc. The lead-free alloy can be further preferably 99.2Sn0.3Ag0.5Cu, 99Sn0.3Ag0.7Cu, 98.5Sn1.0Ag0.5Cu, or 96.5Sn3.0Ag0.5Cu, etc. The medium-low temperature alloy can be further preferably 42Sn58Bi, 64.7Sn35Bi0.3Ag, or 64Sn35Bi1.0Ag, etc.

[0036] Specifically, this embodiment 5 uses 99Sn0.3Ag0.7Cu as an example for illustration.

[0037] Step 2): First, the solder alloy and the agent are put into an extruder for extrusion molding to obtain a solder wire semi-finished product with an integral structure; then the obtained solder wire semi-finished product is drawn to obtain solder wire A with a wire diameter of 1mm.

[0038] Example 6:

[0039] This embodiment 6 also provides a solder wire, and the difference between this embodiment 6 and embodiment 5 is that the agent used in this embodiment 6 is prepared from the above embodiment 2.

[0040] Note: Except for the differences mentioned above, the weight ratio between the solder alloy and the flux, the extrusion molding process, and the wire drawing process used in the solder wire manufacturing process of this embodiment 6 are all the same as in embodiment 5; therefore, they will not be repeated here. It is understood that this embodiment 6 provides a solder wire B with a wire diameter of 1mm.

[0041] Example 7:

[0042] This embodiment 7 also provides a solder wire, and the difference between this embodiment 7 and embodiment 5 is that the agent used in this embodiment 7 is prepared from the above embodiment 3.

[0043] Note: Except for the differences mentioned above, the weight ratio between the solder alloy and the flux, the extrusion molding process, and the wire drawing process used in the solder wire manufacturing process of this embodiment 7 are all the same as in embodiment 5; therefore, they will not be repeated here. It is understood that this embodiment 7 provides a solder wire C with a wire diameter of 1 mm.

[0044] Example 8:

[0045] This embodiment 8 also provides a solder wire, and the difference between this embodiment 8 and embodiment 5 is that the agent used in this embodiment 8 is prepared from the above embodiment 4.

[0046] Note: Except for the differences mentioned above, the weight ratio between the solder alloy and the flux, the extrusion molding process, and the wire drawing process used in the solder wire manufacturing process of this embodiment 8 are all the same as in embodiment 5; therefore, they will not be repeated here. It is understood that this embodiment 8 provides a solder wire D with a wire diameter of 1 mm.

[0047] 3. Performance testing of the solder wire prepared in this application; Laser welding, high-power constant temperature soldering iron welding, and automatic soldering machine welding were performed using the solder wires prepared in Examples 5 to 8 of this application, as well as conventional solder wires (99Sn0.3Ag0.7Cu with a wire diameter of 1 mm and a rosin content of 2%). In any welding operation, the workpieces (such as T2 copper plates with an area of ​​40 mm × 40 mm) and welding parameters corresponding to the above five types of solder wires were the same.

[0048] After completing the above welding operations, use a 10x magnifying glass to count the amount of rosin and solder ball spatter around the solder joints. The test results are shown in Table 1 below.

[0049] Table 1 Performance test results of solder wires obtained in Examples 5-8 of this application and conventional solder wires As shown in Table 1, conventional solder wire is prone to spattering during soldering operations, including at least 13 rosin spatter particles and more than 2 solder balls. In contrast, the solder wire prepared in this application exhibits very low spattering during soldering operations, primarily consisting of rosin spatter particles, with no more than 6 particles, and zero solder balls. Therefore, the spatter suppression performance of the solder wire prepared in this application is far superior to that of conventional solder wire.

[0050] The reason why the solder wire obtained in this application can achieve the above-mentioned advantages is mainly due to the optimized and innovative raw material formulation of the solder wire flux. Specifically: ① In formulating the flux, this application selects polymeric rosin-140 with a high softening point. During the soldering process, it decomposes to produce active substances that effectively remove oxides from the surface of the metal workpiece, thereby promoting good contact between the solder and the metal workpiece surface, improving soldering quality, reducing the surface tension of the solder, improving fluidity, and significantly reducing spatter. ② In formulating the flux, this application selects dimethylolpropionic acid and maleic anhydride in a precisely controlled ratio to form the main activator. Understandably, by combining two activators with low-temperature weak activity and high-temperature strong activity respectively, this application ensures that the solder wire has a continuous and uninterrupted ability to remove oxides from the surface of the metal workpiece during the soldering process, thereby helping to improve soldering quality and reduce spatter caused by the presence of oxides. ③ In formulating the agent, this application uses Triton X-100 and polyoxypropylene glycerol ether in a precisely controlled ratio to form an auxiliary activator. Both activators have good surface activity, which can effectively reduce the interfacial tension between the solder and the surface of the metal workpiece, promote solder wetting and spreading, thereby helping to improve welding quality and effectively reduce spatter. ④ In formulating the agent, this application uses polyethylene glycol dimethacrylate and sodium carboxymethyl cellulose in a precisely controlled ratio to form a film-forming agent. Polyethylene glycol dimethacrylate has good film-forming properties and stability during the welding process, and can form a stable protective film during the welding process, thereby effectively inhibiting solder or rosin spatter; sodium carboxymethyl cellulose has a certain viscosity and can also form a protective film during the welding process, further preventing solder spatter.

[0051] In summary, this application, through technological innovation, has produced a reagent and solder wire that can effectively suppress spatter generation and has excellent wetting properties and reliable welding performance, thus well meeting market demands.

[0052] Many specific details have been set forth in the foregoing description to provide a thorough understanding of the present invention. However, the above description is merely a preferred embodiment of the present invention, and the present invention can be implemented in many other ways different from those described herein. Therefore, the present invention is not limited to the specific embodiments disclosed above. Furthermore, any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention, or modify them into equivalent embodiments, using the methods and techniques disclosed above, without departing from the scope of the present invention. Any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the content of the present invention, shall still fall within the protection scope of the present invention.

Claims

1. A halogen-free, low-splatter solder wire flux, characterized in that: The raw material formulation, by weight percentage, is as follows: 88%–95% polymeric rosin, 4%–13% activator, and 0.2%–1.6% film-forming agent; the activator includes a primary activator and an auxiliary activator. Based on the total weight of the raw materials of the pharmaceutical preparation, the main active agent is composed of 2% to 5% dimethylolpropionic acid and 2% to 5% maleic anhydride, the auxiliary active agent includes 0.1% to 0.6% Triton X-100 and 0.5% to 1.5% polyoxypropylene glycerol ether, the film-forming agent is composed of 0.2% to 0.5% polyethylene glycol dimethacrylate and 0.1% to 1% sodium carboxymethyl cellulose, and the molecular weight of the polyethylene glycol dimethacrylate is 600.

2. The halogen-free, low-splatter solder wire flux according to claim 1, characterized in that: The polymerized rosin used is polymerized rosin-140, which has a softening point of 135℃~145℃.

3. A method for preparing a halogen-free, low-splatter solder wire flux as described in any one of claims 1-2, characterized in that: The production process includes the following steps: S1: Heat the polymerized rosin in the formula until it is completely melted, then add the auxiliary activator and polyethylene glycol dimethacrylate in the formula, and stir thoroughly to obtain the first mixture; S2: While stirring, cool the first mixture. After the first mixture cools to 120℃~130℃, add the formulated amount of main activator and sodium carboxymethyl cellulose, and stir thoroughly again to obtain the halogen-free low-splatter solder wire agent.

4. The method for preparing the halogen-free, low-splatter solder wire flux according to claim 3, characterized in that: In S1 above, after obtaining the first mixture, the first mixture needs to be continuously stirred, and the stirring speed is controlled at 50-60 rpm.

5. The method for preparing the halogen-free, low-splatter solder wire flux according to claim 3, characterized in that: In S2 above, the stirring speed is also controlled at 50-60 rpm.

6. A solder wire, characterized in that: The solder wire is prepared by coating the solder alloy with the halogen-free low-splatter solder wire agent as described in any one of claims 1-2, and by coating or impregnating the solder alloy with the agent to obtain the solder wire. Alternatively, the solder wire can be formed into a single structure by extruding the agent and the solder alloy together using an extrusion molding process.

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