Environment-friendly lead-free soldering tin bar for welding electronic components and production process of environment-friendly lead-free soldering tin bar

Abstract

The invention discloses an environment-friendly lead-free soldering tin bar for welding electronic components and a production process of the environment-friendly lead-free soldering tin bar, and relates to the technical field of welding materials, and the environment-friendly lead-free soldering tin bar is prepared from the following components in percentage by weight: 0.08 to 0.13 weight percent of Ag, 0.1 to 0.6 weight percent of Cu, 0.12 to 0.32 weight percent of Zn, 0.01 to 0.03 weight percent of Te, 0.01 to 0.1 weight percent of rare earth, 0.003 to 0.01 weight percent of In, 0.005 to 0.013 weight percent of Ba, 0.2 to 1 weight percent of Bi, 0.01 to 0.03 weight percent of Sb, 0.001 to 0.02 weight percent of Se, 0.008 to 0.015 weight percent of Ge and the balance of Sn. The soldering tin bar is good in wettability and flowability after being melted, and high in cost performance, welding spot strength and welding spot reliability.

Description

Technical Field

[0001] The invention relates to the technical field of welding materials, and in particular to an environmentally friendly lead-free solder bar for welding electronic components and a production process thereof. Background Art

[0002] In recent years, with the rapid development of electronic products and the enhancement of human environmental awareness, the Sn-Pb solder bars traditionally used in the electronics industry have gradually been replaced by lead-free solder bars. Lead-free solder bars have good thermal conductivity and plasticity, better environmental protection, and can be used to connect electronic components, circuit boards and other metal parts. At present, lead-free solder bars have been widely used in the fields of electronic manufacturing, electrical engineering, metal processing and maintenance.

[0003] The existing lead-free solder bars used for welding electronic components have more or less technical defects such as the solder joint strength and solder joint reliability need to be further improved, the solder joint oxidation corrosion and pinhole phenomenon are serious, and the wettability and fluidity need to be further improved. In order to solve the above problems, the Chinese invention patent with application publication number CN118046134A discloses a lead-free solder bar and its manufacturing process. The lead-free solder bar includes the following components by weight: 94-95 parts of single Sn powder, 2.8-3.3 parts of single Ag powder, 2-3 parts of single Cu powder, 0.02-0.06 parts of single Co powder, and 0.01-0.04 parts of reinforcing additives. The invention uses single Co powder, Ni powder or W powder as additives, and single La powder or single Nd powder as reinforcing additives, which significantly improves the tensile strength and elongation of the solder bar. The tensile strength reaches 1965.3-2452.0MPa. The elongation reaches 10.8-16.1%. The solder bar is better used in connecting electronic components, circuit boards and other metal parts. Its practical application in the fields of electronic manufacturing, electrical engineering, metal processing and maintenance is expanded. However, the lead-free solder bar still has technical problems such as wettability and fluidity need to be further improved, cost performance, solder joint strength and solder joint reliability need to be further improved.

[0004] It can be seen that it is necessary to seek a more effective production process to prepare environmentally friendly lead-free solder bars for welding electronic components with good wettability and fluidity after melting, high cost performance, high solder joint strength and high solder joint reliability. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide an environmentally friendly lead-free solder bar for welding electronic components, which has good wettability and fluidity after melting, high cost performance, high solder joint strength and high solder joint reliability, and a production process thereof.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: an environmentally friendly lead-free solder bar for welding electronic components, comprising the following components in weight percentage: Ag 0.08-0.13wt%, Cu 0.1-0.6wt%, Zn0.12-0.32wt%, Te 0.01-0.03wt%, rare earth 0.01-0.1wt%, In 0.003-0.01wt%, Ba 0.005-0.013wt%, Bi 0.2-1wt%, Sb0.01-0.03wt%, Se 0.001-0.02wt%, Ge 0.008-0.015wt%, and the balance is Sn.

[0007] Preferably, the environmentally friendly lead-free solder bar for welding electronic components includes the following components in weight percentage: Ag 0.1wt%, Cu 0.3wt%, Zn 0.22wt%, Te 0.02wt%, rare earth 0.05wt%, In0.006wt%, Ba 0.01wt%, Bi 0.6wt%, Sb 0.02wt%, Se 0.01wt%, Ge 0.011wt%, and the balance is Sn.

[0008] Preferably, the rare earth is at least one of La, Pr and Ce.

[0009] Another object of the present invention is to provide a production process of the environmentally friendly lead-free solder bar for welding electronic components, comprising the following steps:

[0010] Step S1, using metallic tin, Ag-Sn alloy, Cu-Sn alloy, Zn-Sn alloy, Te-Sn alloy, rare earth-Sn alloy, In-Sn alloy, Ba-Sn alloy, Bi-Sn alloy, Sb-Sn alloy, Se-Sn alloy, Ge-Sn alloy as raw materials, mixing ingredients according to weight percentage of components, grinding and screening to obtain a raw material mixture;

[0011] Step S2, placing the raw material mixture prepared in step S1 into a melting furnace and melting it evenly;

[0012] Step S3: casting the molten alloy to obtain an environmentally friendly lead-free solder bar for welding electronic components.

[0013] Preferably, the grinding and screening in step S1 is grinding through a 200-400 mesh sieve.

[0014] Preferably, the melting in step S2 is performed under vacuum.

[0015] Preferably, the casting molding in step S2 is performed under the protection of an inert gas.

[0016] Preferably, the inert gas is any one of nitrogen, helium, neon and argon.

[0017] Due to the application of the above technical solution, the present invention has the following beneficial effects:

[0018] (1) The production process of the environmentally friendly lead-free solder bar for welding electronic components disclosed in the present invention is simple and easy to operate, has high production efficiency and finished product qualification rate, has low dependence on equipment, is suitable for continuous large-scale production, and has high promotion and application value.

[0019] (2) The environmentally friendly lead-free solder bar for welding electronic components disclosed in the present invention comprises the following components in percentage by weight: Ag 0.08-0.13wt%, Cu 0.1-0.6wt%, Zn 0.12-0.32wt%, Te 0.01-0.03wt%, rare earth 0.01-0.1wt%, In 0.003-0.01wt%, Ba 0.005-0.013wt%, Bi 0.2-1wt%, Sb 0.01-0.03wt%, Se0.001-0.02wt%, Ge 0.008-0.015wt%, and the balance is Sn. Through the mutual cooperation and joint action of various components, the surface tension of molten solder can be effectively reduced, solderability can be improved, oxygen content can be reduced, the alloy structure can be made compact, pinholes in solder joints can be reduced, oxidation corrosion of solder joints can be slowed down, and welding strength and reliability can be improved; the environmentally friendly lead-free solder bar produced has good wettability and fluidity after melting, and has the advantages of high cost performance, high solder joint strength and high solder joint reliability.

[0020] (3) The environmentally friendly lead-free solder bar for welding electronic components disclosed in the present invention can effectively eliminate solder joint bridges, inhibit the oxidation of the alloy, and improve the antioxidant capacity through the reasonable selection of component formula. It can be used for a long time in the molten state, has good fluidity and wettability, and while extending the use time, it is not easy to turn yellow or blue, and can effectively reduce the generation of tin slag.

[0021] (4) The environmentally friendly lead-free solder bar for electronic component welding disclosed in the present invention does not contain lead, is safer and more environmentally friendly to use, and meets the environmental protection requirements of lead-free. It also has good welding performance, excellent solder joint strength and reliability, and is suitable for welding electronic components. DETAILED DESCRIPTION

[0022] 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.

[0023] Example 1

[0024] An environmentally friendly lead-free solder bar for welding electronic components comprises the following components in percentage by weight: 0.08wt% Ag, 0.1wt% Cu, 0.12wt% Zn, 0.01wt% Te, 0.01wt% rare earth, 0.003wt% In, 0.005wt% Ba, 0.2wt% Bi, 0.01wt% Sb, 0.001wt% Se, 0.008wt% Ge, and the balance is Sn; the rare earth is La.

[0025] A production process of the environmentally friendly lead-free solder bar for welding electronic components comprises the following steps:

[0026] Step S1, using metallic tin, Ag-Sn alloy, Cu-Sn alloy, Zn-Sn alloy, Te-Sn alloy, rare earth-Sn alloy, In-Sn alloy, Ba-Sn alloy, Bi-Sn alloy, Sb-Sn alloy, Se-Sn alloy, Ge-Sn alloy as raw materials, mixing ingredients according to weight percentage of components, grinding and screening to obtain a raw material mixture;

[0027] Step S2, placing the raw material mixture prepared in step S1 into a melting furnace and melting it evenly;

[0028] Step S3: casting the molten alloy to obtain an environmentally friendly lead-free solder bar for welding electronic components.

[0029] The grinding and screening in step S1 is grinding through a 200-mesh sieve; the melting in step S2 is melting under vacuum; the casting and molding in step S2 is carried out under the protection of an inert gas; and the inert gas is nitrogen.

[0030] Example 2

[0031] An environmentally friendly lead-free solder bar for welding electronic components comprises the following components in percentage by weight: 0.09wt% Ag, 0.2wt% Cu, 0.18wt% Zn, 0.015wt% Te, 0.04wt% rare earth, 0.006wt% In, 0.008wt% Ba, 0.5wt% Bi, 0.015wt% Sb, 0.008wt% Se, 0.011wt% Ge, and the balance is Sn; the rare earth is Pr.

[0032] A production process of the environmentally friendly lead-free solder bar for welding electronic components comprises the following steps:

[0033] Step S1, using metallic tin, Ag-Sn alloy, Cu-Sn alloy, Zn-Sn alloy, Te-Sn alloy, rare earth-Sn alloy, In-Sn alloy, Ba-Sn alloy, Bi-Sn alloy, Sb-Sn alloy, Se-Sn alloy, Ge-Sn alloy as raw materials, mixing ingredients according to weight percentage of components, grinding and screening to obtain a raw material mixture;

[0034] Step S2, placing the raw material mixture prepared in step S1 into a melting furnace and melting it evenly;

[0035] Step S3: casting the molten alloy to obtain an environmentally friendly lead-free solder bar for welding electronic components.

[0036] The grinding and screening in step S1 is grinding through a 250-mesh sieve; the melting in step S2 is melting under vacuum; the casting molding in step S2 is carried out under the protection of an inert gas; and the inert gas is helium.

[0037] Example 3

[0038] An environmentally friendly lead-free solder bar for welding electronic components comprises the following components in percentage by weight: 0.1wt% Ag, 0.3wt% Cu, 0.22wt% Zn, 0.02wt% Te, 0.05wt% rare earth, 0.006wt% In, 0.01wt% Ba, 0.6wt% Bi, 0.02wt% Sb, 0.01wt% Se, 0.011wt% Ge, and the balance is Sn; the rare earth is Ce.

[0039] A production process of the environmentally friendly lead-free solder bar for welding electronic components comprises the following steps:

[0040] Step S1, using metallic tin, Ag-Sn alloy, Cu-Sn alloy, Zn-Sn alloy, Te-Sn alloy, rare earth-Sn alloy, In-Sn alloy, Ba-Sn alloy, Bi-Sn alloy, Sb-Sn alloy, Se-Sn alloy, Ge-Sn alloy as raw materials, mixing ingredients according to weight percentage of components, grinding and screening to obtain a raw material mixture;

[0041] Step S2, placing the raw material mixture prepared in step S1 into a melting furnace and melting it evenly;

[0042] Step S3: casting the molten alloy to obtain an environmentally friendly lead-free solder bar for welding electronic components.

[0043] The grinding and screening in step S1 is grinding through a 300-mesh sieve; the melting in step S2 is melting under vacuum; the casting molding in step S2 is carried out under the protection of an inert gas; and the inert gas is neon.

[0044] Example 4

[0045] An environmentally friendly lead-free solder bar for welding electronic components comprises the following components in percentage by weight: 0.12wt% of Ag, 0.5wt% of Cu, 0.3wt% of Zn, 0.025wt% of Te, 0.09wt% of rare earth, 0.008wt% of In, 0.012wt% of Ba, 0.9wt% of Bi, 0.025wt% of Sb, 0.013wt% of Se, 0.012wt% of Ge, and the balance is Sn; the rare earth is La, Pr, and Ce mixed in a mass ratio of 1:2:3.

[0046] A production process of the environmentally friendly lead-free solder bar for welding electronic components comprises the following steps:

[0047] Step S1, using metallic tin, Ag-Sn alloy, Cu-Sn alloy, Zn-Sn alloy, Te-Sn alloy, rare earth-Sn alloy, In-Sn alloy, Ba-Sn alloy, Bi-Sn alloy, Sb-Sn alloy, Se-Sn alloy, Ge-Sn alloy as raw materials, mixing ingredients according to weight percentage of components, grinding and screening to obtain a raw material mixture;

[0048] Step S2, placing the raw material mixture prepared in step S1 into a melting furnace and melting it evenly;

[0049] Step S3: casting the molten alloy to obtain an environmentally friendly lead-free solder bar for welding electronic components.

[0050] The grinding and screening in step S1 is grinding through a 350-mesh sieve; the melting in step S2 is melting under vacuum; the casting molding in step S2 is carried out under the protection of an inert gas; and the inert gas is argon.

[0051] Example 5

[0052] An environmentally friendly lead-free solder bar for welding electronic components comprises the following components in percentage by weight: 0.13wt% Ag, 0.6wt% Cu, 0.32wt% Zn, 0.03wt% Te, 0.1wt% rare earth, 0.01wt% In, 0.01wt% Ba, 1wt% Bi, 0.03wt% Sb, 0.02wt% Se, 0.015wt% Ge, and the balance is Sn; the rare earth is La.

[0053] A production process of the environmentally friendly lead-free solder bar for welding electronic components comprises the following steps:

[0054] Step S1, using metallic tin, Ag-Sn alloy, Cu-Sn alloy, Zn-Sn alloy, Te-Sn alloy, rare earth-Sn alloy, In-Sn alloy, Ba-Sn alloy, Bi-Sn alloy, Sb-Sn alloy, Se-Sn alloy, Ge-Sn alloy as raw materials, mixing ingredients according to weight percentage of components, grinding and screening to obtain a raw material mixture;

[0055] Step S2, placing the raw material mixture prepared in step S1 into a melting furnace and melting it evenly;

[0056] Step S3: casting the molten alloy to obtain an environmentally friendly lead-free solder bar for welding electronic components.

[0057] The grinding and screening in step S1 is grinding through a 400-mesh sieve; the melting in step S2 is melting under vacuum; the casting and molding in step S2 is carried out under the protection of an inert gas; and the inert gas is nitrogen.

[0058] Comparative Example 1

[0059] An environmentally friendly lead-free solder bar for welding electronic components and a production process thereof are basically the same as those in Example 1, except that Te and Ge are not added.

[0060] Comparative Example 2

[0061] An environmentally friendly lead-free solder bar for welding electronic components and a production process thereof are basically the same as those in Example 1, except that In and Ba are not added.

[0062] In order to further illustrate the beneficial technical effects of the environmentally friendly lead-free solder bars for welding electronic components involved in each embodiment of the present invention, relevant performance tests were conducted on the environmentally friendly lead-free solder bars for welding electronic components involved in Examples 1-5 and Comparative Examples 1-2. The test results are shown in Table 1. The test method is as follows:

[0063] (1) Fluidity and wettability: The environmentally friendly lead-free solder bar in the molten state is tested in a small tin furnace to measure the time it can maintain a mirror surface. The longer the time it maintains a mirror surface, the better the fluidity and wettability of the solder bar after it is melted.

[0064] (2) Tensile strength and elongation test: The tensile strength and elongation test was carried out on Shimadzu precision electronic material universal testing machine (CMT4305), with a tensile speed of 0.5 mm / s, sample thickness: 1.0 mm, width 3.2 mm, parallel length 10 mm, gauge length 5 mm, and strain rate 10-3 s -1 Each sample was tested 5 times and the average value was taken.

[0065] (3) Void rate test: Reflow soldering and X-ray detection method are used to perform void rate test, where void rate = (S1-S2) / S1, where S1 is the solderable area of ​​the chip and S2 is the actual soldering area of ​​the chip.

[0066] Table 1

[0067]

[0068] As can be seen from Table 1, the environmentally friendly lead-free solder bar for welding electronic components involved in the embodiment of the present invention has better tensile strength and elongation, lower void rate, better wettability and fluidity after melting than the comparative product, and the addition of Te, Ge, In and Ba is beneficial to improving the above properties.

[0069] 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. An environmentally friendly lead-free solder bar for welding electronic components, characterized in that: The invention comprises the following components in weight percentage: Ag 0.08-0.13wt%, Cu 0.1-0.6wt%, Zn 0.12-0.32wt%, Te 0.01-0.03wt%, rare earth 0.01-0.1wt%, In 0.003-0.01wt%, Ba 0.005-0.013wt%, Bi 0.2-1wt%, Sb 0.01-0.03wt%, Se 0.001-0.02wt%, Ge 0.008-0.015wt%, and the balance is Sn.

2. The environmentally friendly lead-free solder bar for welding electronic components according to claim 1, characterized in that: The environmentally friendly lead-free solder bar for welding electronic components comprises the following components in percentage by weight: 0.1wt% Ag, 0.3wt% Cu, 0.22wt% Zn, 0.02wt% Te, 0.05wt% rare earth, 0.006wt% In, 0.01wt% Ba, 0.6wt% Bi, 0.02wt% Sb, 0.01wt% Se, 0.011wt% Ge, and the balance is Sn.

3. The environmentally friendly lead-free solder bar for welding electronic components according to claim 1, characterized in that: The rare earth is at least one of La, Pr and Ce.

4. A production process for environmentally friendly lead-free solder bars for welding electronic components according to any one of claims 1 to 3, characterized in that: The steps include: Step S1, using metallic tin, Ag-Sn alloy, Cu-Sn alloy, Zn-Sn alloy, Te-Sn alloy, rare earth-Sn alloy, In-Sn alloy, Ba-Sn alloy, Bi-Sn alloy, Sb-Sn alloy, Se-Sn alloy, Ge-Sn alloy as raw materials, mixing ingredients according to weight percentage of components, grinding and screening to obtain a raw material mixture; Step S2, placing the raw material mixture prepared in step S1 into a melting furnace and melting it evenly; Step S3: casting the molten alloy to obtain an environmentally friendly lead-free solder bar for welding electronic components.

5. The production process of environmentally friendly lead-free solder bars for welding electronic components according to claim 4, characterized in that: The grinding and screening in step S1 is grinding through a 200-400 mesh sieve.

6. The production process of environmentally friendly lead-free solder bars for welding electronic components according to claim 4, characterized in that: The melting in step S2 is performed under vacuum.

7. The production process of environmentally friendly lead-free solder bars for welding electronic components according to claim 4, characterized in that: The casting molding in step S2 is performed under the protection of an inert gas.

8. The production process of environmentally friendly lead-free solder bars for welding electronic components according to claim 7, characterized in that: The inert gas is any one of nitrogen, helium, neon and argon.

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