Halogen-free low-splashing environment-friendly solder wire and preparation method thereof

Abstract

The invention discloses a halogen-free low-splashing environment-friendly solder wire and a preparation method thereof, and relates to the technical field of electronic welding materials, and the halogen-free low-splashing environment-friendly solder wire is prepared from the following raw materials in percentage by mass: 1-4wt% of halogen-free scaling powder and the balance of lead-free solder; the lead-free solder is composed of the following components of Cu, Bi, Al, Ga, Ir, Ca, In and Sn. The halogen-free scaling powder comprises the following components: (3, 6-diamino acridine-9-yl) boric acid, glycerol triabietate, 3-(N-morpholinyl)-2-hydroxy propanesulfonic acid sodium salt, 3-trihydroxymethyl methylamino-2-hydroxy propanesulfonic acid, hexahydro-1, 3-ethoxy-s-triazine, a functional copolymer, a surface active agent, a corrosion inhibitor, a halogen-free activity reinforcing agent, an antioxidant, a solvent and rosin resin. The solder wire is low in splashing rate, high in surface resistivity and welding spot reliability, free of obvious corrosivity and good in weldability.

Description

Technical Field

[0001] The invention relates to the technical field of electronic welding materials, and in particular to a halogen-free, low-splash, environmentally friendly solder wire and a preparation method thereof. Background Art

[0002] With the popularization and development of 5G communication technology and artificial intelligence, electronic products are constantly moving towards miniaturization, personalization, high precision and high reliability. The circuit integration has been greatly improved, the number of welding joints has increased, and the reliability requirements of solder joints have become higher and higher. This has also put forward higher requirements on the quality of solder wire used for welding electronic components.

[0003] Solder wire is mainly used as a filler metal or a conductive metal welding material during welding. It consists of two parts: tin alloy and flux. During electronic welding, solder wire is used in conjunction with an electric soldering iron. A high-quality electric soldering iron provides stable and continuous melting heat. Solder wire is added to the surface and gaps of electronic components as a filler metal, and fixing electronic components becomes the main component of welding. Currently, commonly used solder wires basically contain halogens. These halogen-containing materials will produce dioxins when burned, and can exist in the environment for many years, and even accumulate in organisms for life and cannot be discharged. It is in this situation that halogen-free environmentally friendly solder wire came into being, and its appearance has attracted great attention in the industry. However, the halogen-free environmentally friendly solder wire on the market still has more or less technical defects such as a high spatter rate during welding, which will affect the appearance of the welded object and the safety of the welding operator, the weldability needs to be further improved, the surface resistivity is low, the corrosion is large, there are microcracks on the surface of the solder joint, and the reliability needs to be further improved.

[0004] In order to solve the above problems, the Chinese invention patent with the authorization announcement number CN103071944B discloses a halogen-free low-spatter solder wire and a preparation method thereof, wherein the solder wire is composed of components by mass percentage: solder is 97.4% to 98.2%, and flux is 1.8-2.6%, wherein the solder is any one of Sn-0.7Cu, Sn-3.0Ag-0.5Cu, and Sn-0.3Ag-0.7Cu; the flux is composed of components by mass percentage: rubber is 12-22%, organic acid is 6.5-8.5%, benzotriazole is 2%, imidazole is 2%, antioxidant oil is 3%, composite active agent is 3.5-4.5%, and the balance is rosin. The preparation method is to first prepare the flux according to the ratio, and then obtain the solder wire through wire extrusion, wire drawing and wire winding processes. The characteristic indexes of the solder wire of the invention meet the requirements of JIS-Z-3197 and IPC-TM-650 standards. The solder joints are bright and full after welding, with little odor, less spatter, and green environmental protection. However, its spatter rate needs to be further reduced, and the surface resistivity and solder joint reliability need to be further improved.

[0005] It can be seen that the development of a halogen-free, low-spatter, environmentally friendly solder wire with low spatter rate, high surface resistivity and solder joint reliability, no obvious corrosion, and good solderability and its preparation method meets market demand, has broad market value and application prospects, and is of great significance to promoting the development of the halogen-free solder wire field. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a halogen-free, low-spatter, environmentally friendly solder wire with low spatter rate, high surface resistivity and solder joint reliability, no obvious corrosiveness, and good solderability, and a preparation method thereof.

[0007] To achieve the above object, the technical solution adopted by the present invention is: a halogen-free, low-spatter, environmentally friendly solder wire, which is made of the following raw materials in percentage by weight: 1-4wt% halogen-free soldering flux, and the balance is lead-free solder; the lead-free solder is composed of the following components in percentage by weight: Cu 0.6-1wt%, Bi 0.01-0.03wt%, Al 0.05-0.08wt%, Ga0.03-0.05wt%, Ir 0.001-0.003wt%, Ca 0.01-0.03wt%, In The halogen-free soldering flux comprises the following components by weight: 2-4 parts of (3,6-diaminoacridine-9-yl)boric acid, 1-2 parts of trirosin acid glycerol, 0.6-1 parts of 3-(N-morpholinyl)-2-hydroxypropanesulfonic acid sodium, 0.8-1.5 parts of 3-trimethylolmethylamine-2-hydroxypropanesulfonic acid, 0.3-0.5 parts of hydroxyethyl hexahydro-s-triazine, 1-3 parts of functional copolymer, 0.2-1 parts of surfactant, and 0.5-1 parts of buffer. 0.1-0.3 parts of etching agent, 0.5-2 parts of halogen-free activity enhancer, 0.1-0.3 parts of antioxidant, 5-10 parts of solvent, 70-85 parts of rosin resin; the functional copolymer includes structural units introduced by the following monomers: 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, N-trihydroxymethyl methacrylamide, acrylamide, methacrylate tricyclo[5.2.1.02,6]dec-8-yl ester.

[0008] Preferably, the preparation method of the functional copolymer comprises the following steps: adding 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, N-trihydroxymethyl methacrylamide, acrylamide, methacrylate tricyclo[5.2.1.02,6]dec-8-yl ester, and an initiator to a high boiling point solvent, stirring and reacting at 60-70° C. in an inert gas atmosphere for 3-5 hours, then removing the solvent by rotary evaporation, dissolving the obtained crude product in water, taking the supernatant and placing it in a dialysis bag, dialyzing it in deionized water for 20-30 hours, and then rotary evaporating the solution in the dialysis bag to remove water to obtain a functional copolymer.

[0009] Preferably, the mass ratio of the 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, N-trihydroxymethyl methacrylamide, acrylamide, methacrylate tricyclo[5.2.1.02,6]dec-8-yl ester, initiator, and high boiling point solvent is 1:(0.8-1.2):0.6:(0.3-0.5):(0.02-0.04):(10-15).

[0010] Preferably, the initiator is azobisisobutyronitrile; the high boiling point solvent is at least one of N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone; and the inert gas is any one of nitrogen, helium, neon, and argon.

[0011] Preferably, the surfactant is 104 DPM, oleyl alcohol polyoxyethylene ether, DYNOL TM At least one of 604 and Surfynol 420.

[0012] Preferably, the corrosion inhibitor is at least one of benzotriazole, benzothiazole and benzimidazole.

[0013] Preferably, the halogen-free activity enhancer is at least one of the halogen-free activity enhancer ST-400 and the halogen-free activity enhancer FR-500, which are provided by Shenzhen Jintenglong Industrial Co., Ltd.

[0014] Preferably, the antioxidant is at least one of antioxidant 1010 and antioxidant BHT.

[0015] Preferably, the solvent is one or more of tetrahydrofurfuryl alcohol, diethylene glycol monobutyl ether, and triethylene glycol butyl ether.

[0016] Preferably, the rosin resin is at least one of 125 rosin, 685 rosin, water-white hydrogenated rosin, and 150 rosin.

[0017] Another object of the present invention is to provide a method for preparing the halogen-free, low-splash, environmentally friendly solder wire, comprising the following steps:

[0018] Step S1, uniformly heating the rosin resin in the halogen-free flux formula to 165-175° C., after all dissolved, adding the halogen-free activity enhancer, hydroxyethyl hexahydro-s-triazine, and functional copolymer in the halogen-free flux formula, stirring until all the materials are dissolved to obtain a composite material, and cooling to 145-155° C.; uniformly mixing other components in the halogen-free flux formula, adding them to the composite material, stirring uniformly at 145-155° C., and then filtering the heated and melted solder paste with a 100-mesh filter and pouring it into the solder flux barrel of the extruder, keeping it warm at 95-105° C., and setting the air pressure to 0.1-0.4 MPa;

[0019] Step S2, select rod solder and install it on the wire extruder, set the wire extrusion temperature of the wire extruder to 75-115°C, the wire extruder speed to 290-330rpm, and the wire diameter to Adjust the wire extrusion hole diameter and the mass percentage content of the flux matched with the solder, and then extrude the wire;

[0020] Step S3, winding the solder wire squeezed in step S2 through three processes of large drawing, medium drawing and small drawing to obtain a halogen-free, low-splash, environmentally friendly solder wire product.

[0021] Preferably, the speed of the wire drawing machine during the large drawing process in step S3 is 1100-1350 rpm, and the wire drawing diameter is The wire drawing speed is 0.004-0.008 m / s; the wire drawing machine speed is 980-1280 rpm during the intermediate drawing process, and the wire drawing diameter is The wire drawing speed is 0.45-0.95 m / s; the wire drawing machine speed is 230-330 rpm during the small drawing process, and the wire drawing diameter is The wire drawing speed is 3 to 6 m / s.

[0022] Due to the application of the above technical solution, the present invention has the following beneficial effects:

[0023] (1) The method for preparing the halogen-free, low-splash, environmentally friendly solder wire disclosed in the present invention has simple process, convenient operation and control, high preparation efficiency and finished product qualification rate, low dependence on equipment, low energy consumption, low capital investment, low labor intensity, little impact on the environment, is suitable for continuous large-scale production, and has high promotion and application value.

[0024] (2) The halogen-free, low-splash, environmentally friendly solder wire disclosed in the present invention comprises lead-free solder composed of the following components in weight percentage: Cu 0.6-1wt%, Bi 0.01-0.03wt%, Al 0.05-0.08wt%, Ga 0.03-0.05wt%, Ir0.001-0.003wt%, Ca 0.01-0.03wt%, In 0.005-0.01wt%, and the balance is Sn; through the mutual cooperation between the components, the prepared solder not only has the characteristics of dense solder joints without microcracks when used, but also has advantages in reliability such as spreading rate, wettability, and mechanical properties; and no expensive silver is added, which effectively improves the cost performance.

[0025] (3) The halogen-free, low-splash, environmentally friendly solder wire disclosed in the present invention comprises the following components in parts by weight: 2-4 parts of (3,6-diaminoacridine-9-yl)boric acid, 1-2 parts of trirosin acid glycerol, 0.6-1 parts of 3-(N-morpholinyl)-2-hydroxypropanesulfonic acid sodium, 0.8-1.5 parts of 3-trimethylolmethylamine-2-hydroxypropanesulfonic acid, 0.3-0.5 parts of hydroxyethyl hexahydro-s-triazine, 1-3 parts of functional copolymer, 0.2-1 parts of surfactant, and 0.5-1 parts of buffer. 0.1-0.3 parts of etching agent, 0.5-2 parts of halogen-free activity enhancer, 0.1-0.3 parts of antioxidant, 5-10 parts of solvent, 70-85 parts of rosin resin; the functional copolymer includes the structural units introduced by the following monomers: 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, N-trimethylolmethyl acrylamide, acrylamide, methacrylate tricyclo[5.2.1.02,6]dec-8-yl ester. Through the mutual cooperation between the components, the spatter rate can be effectively reduced, the weldability and solder joint reliability can be improved, and the surface resistivity can be effectively improved when combined with the solder, so that the prepared solder wire has no obvious corrosion.

[0026] (4) The halogen-free, low-splash, environmentally friendly solder wire disclosed in the present invention is halogen-free and lead-free, has better environmental protection performance, and is safer to use; through the reasonable selection of the types and dosage ratios of various ingredients and components, it can improve solderability, increase welding efficiency, reduce spatter during welding, and reduce subsequent corrosion. DETAILED DESCRIPTION

[0027] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art may think of other obvious variations.

[0028] Example 1

[0029] A halogen-free, low-spatter, environmentally friendly solder wire is made of the following raw materials in percentage by weight: 1wt% halogen-free soldering flux, the balance is lead-free solder; the lead-free solder is composed of the following components in percentage by weight: 0.6wt% Cu, 0.01wt% Bi, 0.05wt% Al, 0.03wt% Ga, 0.001wt% Ir, 0.01wt% Ca, 0.01wt% In 0.005wt%, the balance is Sn; the halogen-free soldering flux comprises the following components in parts by weight: 2 parts of (3,6-diaminoacridine-9-yl)boric acid, 1 part of trirosin acid glycerol, 0.6 parts of 3-(N-morpholinyl)-2-hydroxypropanesulfonate sodium, 0.8 parts of 3-trimethylolmethylamine-2-hydroxypropanesulfonic acid, 0.3 parts of hydroxyethyl hexahydro-s-triazine, 1 part of functional copolymer, 0.2 parts of surfactant, 0.1 parts of corrosion inhibitor, 0.5 parts of halogen-free activity enhancer, 0.1 parts of antioxidant, 5 parts of solvent, and 70 parts of rosin resin; the functional copolymer comprises structural units introduced by the following monomers: 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, N-trimethylolmethyl acrylamide, acrylamide, and methacrylate tricyclo[5.2.1.02,6]dec-8-yl ester.

[0030] The preparation method of the functional copolymer comprises the following steps: adding 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, N-trihydroxymethyl methacrylamide, acrylamide, methacrylate tricyclo[5.2.1.02,6]dec-8-yl ester and an initiator into a high boiling point solvent, stirring and reacting at 60°C for 3 hours in an inert gas atmosphere, then removing the solvent by rotary evaporation, dissolving the obtained crude product in water, taking the supernatant and placing it in a dialysis bag, dialyzing it in deionized water for 20 hours, and then rotary evaporating the solution in the dialysis bag to remove water to obtain a functional copolymer; the mass ratio of 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, N-trihydroxymethyl methacrylamide, acrylamide, methacrylate tricyclo[5.2.1.02,6]dec-8-yl ester, initiator, and high boiling point solvent is 1:0.8:0.6:0.3:0.02:10; the initiator is azobisisobutyronitrile; the high boiling point solvent is N,N-dimethylformamide; the inert gas is nitrogen; the M of the obtained functional copolymer is measured by GPC test. n =16370 g / mol, M W / M n=1.357; calculated by elemental analysis and weight change, the mass ratio of the structural units introduced by 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, N-trihydroxymethyl methacrylamide, acrylamide, and tricyclo[5.2.1.02,6]dec-8-yl methacrylate in the functional copolymer is 0.99:0.78:0.59:0.27.

[0031] The surfactant is 104DPM; the corrosion inhibitor is benzotriazole; the halogen-free activity enhancer is halogen-free activity enhancer ST-400, provided by Shenzhen Jintenglong Industrial Co., Ltd.; the antioxidant is antioxidant 1010; the solvent is tetrahydrofurfuryl alcohol; the rosin resin is 125 rosin.

[0032] A method for preparing the halogen-free, low-splash, environmentally friendly solder wire comprises the following steps:

[0033] Step S1, uniformly heating the rosin resin in the halogen-free flux formula to 165° C., after all the resin is dissolved, adding the halogen-free activity enhancer, hydroxyethyl hexahydro-s-triazine and functional copolymer in the halogen-free flux formula, stirring until all the materials are dissolved to obtain a composite material, and cooling to 145° C.; uniformly mixing the other components in the halogen-free flux formula, adding them to the composite material, stirring uniformly at 145° C., and then filtering the heated and melted solder paste with a 100-mesh filter and pouring it into the solder flux barrel of the wire extruder, keeping it at 95° C., and setting the air pressure to 0.1 MPa;

[0034] Step S2, select rod solder and install it on the wire extruder, set the wire extrusion temperature of the wire extruder to 75°C, the wire extruder speed to 290rpm, and the wire diameter to Adjust the wire extrusion hole diameter and the mass percentage content of the flux matched with the solder, and then extrude the wire;

[0035] Step S3, winding the solder wire squeezed in step S2 through three processes of large drawing, medium drawing and small drawing to obtain a halogen-free, low-splash, environmentally friendly solder wire product.

[0036] In step S3, the wire drawing machine speed is 1100 rpm and the wire drawing diameter is The wire drawing speed is 0.004m / s; the wire drawing machine speed is 980rpm during the intermediate drawing process, and the wire drawing diameter is The wire drawing speed is 0.45m / s; the wire drawing machine speed is 230rpm during the small drawing process, and the wire drawing diameter is The wire drawing speed is 3m / s.

[0037] Example 2

[0038] A halogen-free, low-splash, environmentally friendly solder wire is made of the following raw materials in percentage by weight: 2wt% of halogen-free soldering flux, and the balance is lead-free solder; the lead-free solder is composed of the following components in percentage by weight: 0.7wt% of Cu, 0.015wt% of Bi, 0.06wt% of Al, 0.035wt% of Ga, 0.0015wt% of Ir, 0.015wt% of Ca, 0.006wt% of In, and the balance is Sn; the halogen-free soldering flux comprises the following components in parts by weight: 2.5 parts of (3,6-diaminoacridine-9-yl)boric acid, 1.2 parts of trirosin acid glyceride, 0.7 parts of sodium 3-(N-morpholinyl)-2-hydroxypropanesulfonate, 1 part of 3-trihydroxymethylmethylamine-2-hydroxypropanesulfonic acid, 0.35 parts of hydroxyethyl hexahydro-s-triazine, 1.5 parts of functional copolymer, 0.4 parts of surfactant, and corrosion inhibitor. 0.15 parts, halogen-free activity enhancer 0.9 parts, antioxidant 0.15 parts, solvent 6 parts, rosin resin 75 parts; the functional copolymer includes structural units introduced by the following monomers: 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, N-trihydroxymethyl methacrylamide, acrylamide, methacrylate tricyclo[5.2.1.02,6]dec-8-yl ester.

[0039] The preparation method of the functional copolymer comprises the following steps: adding 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, N-trihydroxymethyl methacrylamide, acrylamide, methacrylate tricyclo[5.2.1.02,6]dec-8-yl ester and an initiator into a high boiling point solvent, stirring and reacting at 63°C for 3.5 hours in an inert gas atmosphere, then removing the solvent by rotary evaporation, dissolving the obtained crude product in water, taking the supernatant and placing it in a dialysis bag, dialyzing it in deionized water for 23 hours, and then isolating the supernatant into a dialysis bag. The solution in the precipitate bag is subjected to rotary evaporation to remove water to obtain a functional copolymer; the mass ratio of the 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, N-trihydroxymethyl methacrylamide, acrylamide, methacrylate tricyclo[5.2.1.02,6]dec-8-yl ester, initiator, and high boiling point solvent is 1:0.9:0.6:0.35:0.025:12; the initiator is azobisisobutyronitrile; the high boiling point solvent is N,N-dimethylacetamide; and the inert gas is helium.

[0040] The surfactant is oleyl alcohol polyoxyethylene ether; the corrosion inhibitor is benzothiazole; the halogen-free activity enhancer is halogen-free active agent FR-500, provided by Shenzhen Jintenglong Industrial Co., Ltd.; the antioxidant is antioxidant BHT; the solvent is diethylene glycol monobutyl ether; and the rosin resin is 685 rosin.

[0041] A method for preparing the halogen-free, low-splash, environmentally friendly solder wire comprises the following steps:

[0042] Step S1, uniformly heating the rosin resin in the halogen-free flux formula to 168° C., after all the resin is dissolved, adding the halogen-free activity enhancer, hydroxyethyl hexahydro-s-triazine, and functional copolymer in the halogen-free flux formula, stirring until all the materials are dissolved to obtain a composite material, and cooling to 148° C.; uniformly mixing the other components in the halogen-free flux formula, adding them to the composite material, stirring uniformly at 148° C., and then filtering the heated and melted solder paste with a 100-mesh filter and pouring it into the solder flux barrel of the extruder and keeping it at 98° C., and the air pressure is set to 0.2 MPa;

[0043] Step S2: Select a rod-shaped solder and install it on a wire extruder. Set the wire extrusion temperature to 85°C and the speed to 300 rpm. Adjust the wire extrusion hole diameter and the mass percentage content of the flux matched with the solder, and then extrude the wire;

[0044] Step S3, winding the solder wire squeezed in step S2 through three processes of large drawing, medium drawing and small drawing to obtain a halogen-free, low-splash, environmentally friendly solder wire product.

[0045] In step S3, the wire drawing machine speed is 1150 rpm and the wire drawing diameter is The wire drawing speed is 0.006m / s; the wire drawing machine speed is 1080rpm during the intermediate drawing process, and the wire drawing diameter is The wire drawing speed is 0.55m / s; the wire drawing machine speed is 260rpm during the small drawing process, and the wire drawing diameter is The wire drawing speed is 4 m / s.

[0046] Example 3

[0047] A halogen-free, low-splash, environmentally friendly solder wire is made of the following raw materials in percentage by weight: 2.5wt% of halogen-free soldering flux, and the balance is lead-free solder; the lead-free solder is composed of the following components in percentage by weight: 0.8wt% of Cu, 0.02wt% of Bi, 0.065wt% of Al, 0.04wt% of Ga, 0.002wt% of Ir, 0.02wt% of Ca, 0.0075wt% of In, and the balance is Sn; the halogen-free soldering flux comprises the following components in parts by weight: 3 parts of (3,6-diaminoacridine-9-yl)boric acid, 1.5 parts of trirosin acid glyceride, 0.8 parts of sodium 3-(N-morpholinyl)-2-hydroxypropanesulfonate, 1.2 parts of 3-trihydroxymethylmethylamine-2-hydroxypropanesulfonic acid, 0.4 parts of hydroxyethyl hexahydro-s-triazine, 2 parts of functional copolymer, 0.7 parts of surfactant, and 0.0075wt% of corrosion inhibitor. .2 parts, halogen-free activity enhancer 1.4 parts, antioxidant 0.2 parts, solvent 7.5 parts, rosin resin 79 parts; the functional copolymer includes structural units introduced by the following monomers: 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, N-trihydroxymethylmethylacrylamide, acrylamide, methacrylate tricyclo[5.2.1.02,6]dec-8-yl ester.

[0048] The preparation method of the functional copolymer comprises the following steps: adding 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, N-trihydroxymethyl methacrylamide, acrylamide, methacrylate tricyclo[5.2.1.02,6]dec-8-yl ester and an initiator into a high boiling point solvent, stirring and reacting at 65°C for 4 hours in an inert gas atmosphere, then removing the solvent by rotary evaporation, dissolving the obtained crude product in water, taking the supernatant and placing it in a dialysis bag, dialysing it in deionized water for 25 hours, and then The solution in the dialysis bag is subjected to rotary evaporation to remove water to obtain a functional copolymer; the mass ratio of the 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, N-trihydroxymethyl methacrylamide, acrylamide, methacrylate tricyclo[5.2.1.02,6]dec-8-yl ester, initiator, and high boiling point solvent is 1:1:0.6:0.4:0.03:13; the initiator is azobisisobutyronitrile; the high boiling point solvent is N-methylpyrrolidone; and the inert gas is neon.

[0049] The surfactant is DYNOL TM 604; the corrosion inhibitor is benzimidazole; the halogen-free activity enhancer is halogen-free activity agent ST-400, provided by Shenzhen Jintenglong Industrial Co., Ltd.; the antioxidant is antioxidant 1010; the solvent is triethylene glycol butyl ether; the rosin resin is water-white hydrogenated rosin.

[0050] A method for preparing the halogen-free, low-splash, environmentally friendly solder wire comprises the following steps:

[0051] Step S1, uniformly heating the rosin resin in the halogen-free flux formula to 170° C., after all the rosin resin is dissolved, adding the halogen-free activity enhancer, hydroxyethyl hexahydro-s-triazine and functional copolymer in the halogen-free flux formula, stirring until all the materials are dissolved to obtain a composite material, and cooling to 150° C.; uniformly mixing the other components in the halogen-free flux formula, adding them to the composite material, stirring uniformly at 150° C., and then filtering the heated and melted solder paste with a 100-mesh filter and pouring it into the solder flux barrel of the wire extruder for insulation at 100° C., and setting the air pressure to 0.25 MPa;

[0052] Step S2, select rod solder and install it on the wire extruder, set the wire extrusion temperature of the wire extruder to 95°C, the wire extruder speed to 315rpm, and the wire diameter to Adjust the wire extrusion hole diameter and the mass percentage content of the flux matched with the solder, and then extrude the wire;

[0053] Step S3, winding the solder wire squeezed in step S2 through three processes of large drawing, medium drawing and small drawing to obtain a halogen-free, low-splash, environmentally friendly solder wire product.

[0054] In step S3, the wire drawing machine speed is 1250 rpm and the wire drawing diameter is The wire drawing speed is 0.006m / s; the wire drawing machine speed is 1180rpm during the intermediate drawing process, and the wire drawing diameter is The wire drawing speed is 0.75m / s; the wire drawing machine speed is 300rpm during the small drawing process, and the wire drawing diameter is The wire drawing speed is 4.5 m / s.

[0055] Example 4

[0056] A halogen-free, low-splash, environmentally friendly solder wire is made of the following raw materials in percentage by weight: 3.5wt% halogen-free soldering flux, the balance being lead-free solder; the lead-free solder is composed of the following components in percentage by weight: 0.95wt% Cu, 0.025wt% Bi, 0.075wt% Al, 0.045wt% Ga, 0.0025wt% Ir, 0.025wt% Ca, 0.009wt% In, the balance being Sn; the halogen-free soldering flux comprises the following components in parts by weight: 3.5 parts of (3,6-diaminoacridine-9-yl)boric acid, 1.8 parts of trirosin acid glyceride, 0.9 parts of sodium 3-(N-morpholinyl)-2-hydroxypropanesulfonate, 1.4 parts of 3-trihydroxymethylmethylamine-2-hydroxypropanesulfonic acid, 0.45 parts of hydroxyethyl hexahydro-s-triazine, 2.5 parts of functional copolymer, and 0. 9 parts, corrosion inhibitor 0.25 parts, halogen-free activity enhancer 1.8 parts, antioxidant 0.25 parts, solvent 9 parts, rosin resin 83 parts; the functional copolymer includes structural units introduced by the following monomers: 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, N-trihydroxymethyl methacrylamide, acrylamide, methacrylate tricyclo[5.2.1.02,6]dec-8-yl ester.

[0057] The preparation method of the functional copolymer comprises the following steps: adding 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, N-trihydroxymethyl methacrylamide, acrylamide, methacrylate tricyclo[5.2.1.02,6]dec-8-yl ester and an initiator into a high boiling point solvent, stirring and reacting at 68° C. for 4.5 hours in an inert gas atmosphere, then removing the solvent by rotary evaporation, dissolving the obtained crude product in water, taking the supernatant and placing it in a dialysis bag, dialysis in deionized water for 28 hours, and then removing water from the solution in the dialysis bag by rotary evaporation to obtain the functional copolymer; The mass ratio of the 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, N-trihydroxymethyl methacrylamide, acrylamide, methacrylate tricyclo[5.2.1.02,6]dec-8-yl ester, initiator, and high boiling point solvent is 1:1.1:0.6:0.45:0.035:14; the initiator is azobisisobutyronitrile; the high boiling point solvent is a mixture of N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone in a mass ratio of 1:1:2; the inert gas is argon; the surfactant is 104 DPM, oleyl alcohol polyoxyethylene ether, DYNOL TM604 and Surfynol 420 are mixed in a mass ratio of 1:2:2:3; the corrosion inhibitor is a mixture of benzotriazole, benzothiazole and benzimidazole in a mass ratio of 1:2:1; the halogen-free activity enhancer is a mixture of halogen-free active agent ST-400 and halogen-free active agent FR-500 in a mass ratio of 3:5; the antioxidant is a mixture of antioxidant 1010 and antioxidant BHT in a mass ratio of 1:3; the solvent is a mixture of tetrahydrofurfuryl alcohol, diethylene glycol monobutyl ether and triethylene glycol butyl ether in a mass ratio of 1:1:1; the rosin resin is a mixture of 125 rosin, 685 rosin, water-white hydrogenated rosin and 150 rosin in a mass ratio of 1:4:3:1.

[0058] A method for preparing the halogen-free, low-splash, environmentally friendly solder wire comprises the following steps:

[0059] Step S1, uniformly heating the rosin resin in the halogen-free flux formula to 173° C., after all the resin is dissolved, adding the halogen-free activity enhancer, hydroxyethyl hexahydro-s-triazine and functional copolymer in the halogen-free flux formula, stirring until all the materials are dissolved to obtain a composite material, and cooling to 153° C.; uniformly mixing the other components in the halogen-free flux formula, adding them to the composite material, stirring uniformly at 153° C., and then filtering the heated and melted solder paste with a 100-mesh filter and pouring it into the solder flux barrel of the wire extruder and keeping it at 103° C., and the air pressure is set to 0.35 MPa;

[0060] Step S2: Select a rod-shaped solder and install it on a wire extruder. Set the wire extruder extrusion temperature to 110°C and the wire extruder speed to 320 rpm. Adjust the wire extrusion hole diameter and the mass percentage content of the flux matched with the solder, and then extrude the wire;

[0061] Step S3, winding the solder wire squeezed in step S2 through three processes of large drawing, medium drawing and small drawing to obtain a halogen-free, low-splash, environmentally friendly solder wire product.

[0062] In step S3, the wire drawing machine speed is 1330 rpm, and the wire drawing diameter is The wire drawing speed is 0.0075m / s; the wire drawing machine speed is 1250rpm during the intermediate drawing process, and the wire drawing diameter is The wire drawing speed is 0.9m / s; the wire drawing machine speed is 320rpm during the small drawing process, and the wire drawing diameter is The wire drawing speed is 5.5 m / s.

[0063] Example 5

[0064] A halogen-free, low-spatter, environmentally friendly solder wire is made of the following raw materials in percentage by weight: 4wt% halogen-free soldering flux, the balance is lead-free solder; the lead-free solder is composed of the following components in percentage by weight: 1wt% Cu, 0.03wt% Bi, 0.08wt% Al, 0.05wt% Ga, 0.003wt% Ir, 0.03wt% Ca, 0.01wt% In 0.01wt%, the balance is Sn; the halogen-free soldering flux comprises the following components in parts by weight: 4 parts of (3,6-diaminoacridine-9-yl)boric acid, 2 parts of trirosin acid glycerol, 1 part of 3-(N-morpholinyl)-2-hydroxypropanesulfonate sodium, 1.5 parts of 3-trihydroxymethylmethylamine-2-hydroxypropanesulfonic acid, 0.5 parts of hydroxyethyl hexahydro-s-triazine, 3 parts of functional copolymer, 1 part of surfactant, 0.3 parts of corrosion inhibitor, 2 parts of halogen-free activity enhancer, 0.3 parts of antioxidant, 10 parts of solvent, and 85 parts of rosin resin; the functional copolymer comprises structural units introduced by the following monomers: 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, N-trihydroxymethyl methacrylamide, acrylamide, and methacrylate tricyclo[5.2.1.02,6]dec-8-yl ester.

[0065] The preparation method of the functional copolymer comprises the following steps: adding 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, N-trihydroxymethyl methacrylamide, acrylamide, methacrylate tricyclo[5.2.1.02,6]dec-8-yl ester and an initiator into a high boiling point solvent, stirring and reacting at 70°C for 5 hours in an inert gas atmosphere, then removing the solvent by rotary evaporation, dissolving the obtained crude product in water, taking the supernatant and placing it in a dialysis bag, dialyzing it in deionized water for 30 hours, and then isolating the supernatant into a dialysis bag. The solution in the separation bag is rotary evaporated to remove water to obtain a functional copolymer; the mass ratio of the 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, N-trihydroxymethyl methacrylamide, acrylamide, methacrylate tricyclo[5.2.1.02,6]dec-8-yl ester, initiator, and high boiling point solvent is 1:1.2:0.6:0.5:0.04:15; the initiator is azobisisobutyronitrile; the high boiling point solvent is N,N-dimethylformamide; and the inert gas is nitrogen.

[0066] The surfactant is 104DPM; the corrosion inhibitor is benzothiazole; the halogen-free activity enhancer is halogen-free activity agent ST-400, provided by Shenzhen Jintenglong Industrial Co., Ltd.; the antioxidant is antioxidant 1010; the solvent is tetrahydrofurfuryl alcohol; the rosin resin is 150 rosin.

[0067] A method for preparing the halogen-free, low-splash, environmentally friendly solder wire comprises the following steps:

[0068] Step S1, uniformly heating the rosin resin in the halogen-free flux formula to 175° C., after all the rosin resin is dissolved, adding the halogen-free activity enhancer, hydroxyethyl hexahydro-s-triazine and functional copolymer in the halogen-free flux formula, stirring until all the materials are dissolved to obtain a composite material, and cooling to 155° C.; uniformly mixing the other components in the halogen-free flux formula, adding them to the composite material, stirring uniformly at 155° C., and then filtering the heated and melted solder paste with a 100-mesh filter and pouring it into the solder flux barrel of the extruder and keeping it at 105° C., and the air pressure is set to 0.4 MPa;

[0069] Step S2, select rod solder and install it on the wire extruder, set the wire extrusion temperature of the wire extruder to 115℃, the wire extruder speed to 330rpm, and the wire diameter to Adjust the wire extrusion hole diameter and the mass percentage content of the flux matched with the solder, and then extrude the wire;

[0070] Step S3, winding the solder wire squeezed in step S2 through three processes of large drawing, medium drawing and small drawing to obtain a halogen-free, low-splash, environmentally friendly solder wire product.

[0071] In step S3, the wire drawing machine speed is 1350 rpm and the wire drawing diameter is The wire drawing speed is 0.008m / s; the wire drawing machine speed is 1280rpm during the intermediate drawing process, and the wire drawing diameter is The wire drawing speed is 0.95m / s; the wire drawing machine speed is 330rpm during the small drawing process, and the wire drawing diameter is The wire drawing speed is 6m / s.

[0072] Comparative Example 1

[0073] A halogen-free, low-splash, environmentally friendly solder wire and a preparation method thereof are substantially the same as those in Example 1, except that Ir and functional copolymers are not added.

[0074] Comparative Example 2

[0075] A halogen-free, low-splash, environmentally friendly solder wire and a preparation method thereof are substantially the same as those in Example 1, except that In and (3,6-diaminoacridine-9-yl)boric acid are not added.

[0076] In order to further illustrate the beneficial technical effects of the halogen-free, low-splash, environmentally friendly solder wires involved in the embodiments of the present invention, relevant performance tests were conducted on the halogen-free, low-splash, environmentally friendly solder wires involved in Examples 1-5 and Comparative Examples 1-2. The test results are shown in Table 1. The test method is as follows:

[0077] (1) Expansion rate: Refer to Section 3.9 of SJ2660-1986 for testing.

[0078] (2) Copper plate corrosion and surface insulation resistance: Tested in accordance with SJ / T 11389-2019.

[0079] (3) Spatter volume: Tested in accordance with SJ / T 11390-2019.

[0080] (4) Solder joint fracture strength: Tested in accordance with SJ / T 11390-2019.

[0081] Table 1

[0082]

[0083] As can be seen from Table 1, the halogen-free, low-splash, environmentally friendly solder wire involved in the embodiment of the present invention has better solderability, solder joint reliability, lower spatter and corrosiveness, and higher surface insulation resistance than the comparative example product. The addition of Ir, In, (3,6-diaminoacridine-9-yl)boric acid and functional copolymer is beneficial to improving the above properties.

[0084] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the contents of the present invention and implement them accordingly. They cannot be used to limit the protection scope of the present invention. All equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A halogen-free, low-splash, environmentally friendly solder wire, characterized in that: The invention is made of the following raw materials in percentage by mass: 1-4wt% of halogen-free soldering flux and the balance of lead-free solder; The lead-free solder is composed of the following components in weight percentage: Cu 0.6-1wt%, Bi 0.01-0.03wt%, Al 0.05-0.08wt%, Ga 0.03-0.05wt%, Ir 0.001-0.003wt%, Ca 0.01-0.03wt%, In 0.005-0.01wt%, and the balance is Sn; the halogen-free soldering flux includes the following components in weight parts: (3,6-diaminoacridine-9-yl)boric acid 2-4 parts, trirosin acid glycerol 1-2 parts, 3-(N-morpholinyl)-2-hydroxypropanesulfonic acid sodium 0.6-1 parts, 3-trihydroxymethylmethylamine-2-hydroxypropanesulfonic acid 0.8-1.5 parts, hydroxyethyl hexahydro-s-triazine 0.3-0.5 parts, functional copolymer 1-3 parts, surfactant 0.2-1 parts, buffer 0.1-0.3 parts of etching agent, 0.5-2 parts of halogen-free activity enhancer, 0.1-0.3 parts of antioxidant, 5-10 parts of solvent, 70-85 parts of rosin resin; the functional copolymer includes structural units introduced by the following monomers: 3-[N, N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, N-trihydroxymethyl methacrylamide, acrylamide, methacrylate tricyclo[5.2.1.02,6]dec-8-yl ester.

2. The halogen-free, low-splash, environmentally friendly solder wire according to claim 1, characterized in that: The preparation method of the functional copolymer comprises the following steps: adding 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, N-trihydroxymethyl methacrylamide, acrylamide, methacrylate tricyclo[5.2.1.02,6]dec-8-yl ester and an initiator into a high boiling point solvent, stirring and reacting for 3-5 hours at 60-70° C. in an inert gas atmosphere, then removing the solvent by rotary evaporation, dissolving the obtained crude product in water, taking the supernatant and placing it in a dialysis bag, dialysis in deionized water for 20-30 hours, and then removing water from the solution in the dialysis bag by rotary evaporation to obtain the functional copolymer.

3. The halogen-free, low-splash, environmentally friendly solder wire according to claim 2, characterized in that: The mass ratio of the 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, N-trihydroxymethyl acrylamide, acrylamide, methacrylate tricyclo[5.2.1.02,6]dec-8-yl ester, initiator, and high boiling point solvent is 1:(0.8-1.2):0.6:(0.3-0.5):(0.02-0.04):(10-15).

4. The halogen-free, low-splash, environmentally friendly solder wire according to claim 2, characterized in that: The initiator is azobisisobutyronitrile; the high boiling point solvent is at least one of N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone; and the inert gas is any one of nitrogen, helium, neon, and argon.

5. The halogen-free, low-splash, environmentally friendly solder wire according to claim 1, characterized in that: The surfactant is 104 DPM, oleyl alcohol polyoxyethylene ether, DYNOL TM 604, Surfynol 420; the corrosion inhibitor is at least one of benzotriazole, benzothiazole, and benzimidazole.

6. The halogen-free, low-splash, environmentally friendly solder wire according to claim 1, characterized in that: The halogen-free activity enhancer is at least one of the halogen-free activity enhancer ST-400 and the halogen-free activity enhancer FR-500.

7. The halogen-free, low-splash, environmentally friendly solder wire according to claim 1, characterized in that: The antioxidant is at least one of antioxidant 1010 and antioxidant BHT.

8. The halogen-free, low-splash, environmentally friendly solder wire according to claim 1, characterized in that: The solvent is one or more of tetrahydrofurfuryl alcohol, diethylene glycol monobutyl ether, and triethylene glycol butyl ether; the rosin resin is at least one of 125 rosin, 685 rosin, water-white hydrogenated rosin, and 150 rosin.

9. A method for preparing the halogen-free, low-splash, environmentally friendly solder wire according to any one of claims 1 to 8, characterized in that: The steps include: Step S1, uniformly heating the rosin resin in the halogen-free flux formula to 165-175° C., after all dissolved, adding the halogen-free activity enhancer, hydroxyethyl hexahydro-s-triazine, and functional copolymer in the halogen-free flux formula, stirring until all the materials are dissolved to obtain a composite material, and cooling to 145-155° C.; uniformly mixing other components in the halogen-free flux formula, adding them to the composite material, stirring uniformly at 145-155° C., and then filtering the heated and melted solder paste with a 100-mesh filter and pouring it into the solder flux barrel of the extruder, keeping it warm at 95-105° C., and setting the air pressure to 0.1-0.4 MPa; Step S2, select rod solder and install it on the wire extruder, set the wire extrusion temperature of the wire extruder to 75-115°C, the wire extruder speed to 290-330rpm, and the wire diameter to Adjust the wire extrusion hole diameter and the mass percentage content of the flux matched with the solder, and then extrude the wire; Step S3, winding the solder wire squeezed in step S2 through three processes of large drawing, medium drawing and small drawing to obtain a halogen-free, low-splash, environmentally friendly solder wire product.

10. The method for preparing the halogen-free, low-splash, environmentally friendly solder wire according to claim 9, characterized in that: In the process of drawing in step S3, the speed of the wire drawing machine is 1100-1350 rpm, and the wire drawing diameter is The wire drawing speed is 0.004-0.008 m / s; the wire drawing machine speed is 980-1280 rpm during the intermediate drawing process, and the wire drawing diameter is The wire drawing speed is 0.45-0.95 m / s; the wire drawing machine speed is 230-330 rpm during the small drawing process, and the wire drawing diameter is The wire drawing speed is 3 to 6 m / s.

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