CN114669908B - High-reliability preformed soldering lug and preparation method thereof - Google Patents

Abstract

The application provides a high-reliability preformed soldering lug, which comprises a core layer and a shell layer arranged on the periphery of the core layer, wherein a solid soldering flux core layer is embedded in a solder alloy layer to form a sandwich biscuit shape, so that the soldering flux can be well protected from being oxidized, the soldering flux does not need to be coated before soldering, the soldering flux does not need to be removed after soldering is finished, the manufacturing cost and the cavitation rate of a soldered surface after soldering are reduced, and the reliability of the soldering lug is improved; the shell of the solder alloy comprises tin, silver, copper, indium, cerium, vanadium, lutetium yttrium and zinc, the conductivity and the heat transfer property of the soldering lug can be improved by adding a small amount of rare earth elements lutetium, yttrium and cerium, the melting point of the soldering lug can be improved by adding indium, vanadium and zinc, the solidification and crystallization state of the soldering lug can be improved, and the signal interference caused by metals can be avoided because no magnetic materials such as lead element, iron element, cobalt element, nickel element and niobium element are added.

Description

High-reliability preformed soldering lug and preparation method thereof

Technical Field

The application belongs to the technical field of welding materials, and particularly relates to a high-reliability preformed soldering lug and a preparation method thereof.

Background

At present, the most widely used soldering material in electronic product packaging is solder paste, but in the case that the printing method cannot meet the requirements due to the large solder consumption, a method for replacing the solder paste by a preformed soldering lug coated with soldering flux on the surface is adopted.

The soldering lug on the market at present is basically a bare soldering lug and a majority of soldering flux is coated on the surface of the soldering lug, but a layer of soldering flux is coated on the surface of the soldering lug, the soldering flux film on the surface of a preset part is easily weakened or oxidized to lead the components in the soldering flux to be not well used, the preformed soldering lug has a specific processing shape, the soldering lug is generally small in size and light in weight, and particularly, the high-precision soldering is realized by precisely controlling the content of solder metal in the packaging process of electronic products, however, most of the solder of the conventional preformed soldering lug contains magnetic materials such as lead element, iron element, cobalt element, nickel element, niobium element and the like, so that the problems of signal interference and the like are easily caused, and the selection of the solder metal is extremely important.

Thus, there is a need for a high reliability preformed solder tab and method of making the same.

Disclosure of Invention

The application provides a preformed soldering lug for solving the technical problems that a soldering flux film is extremely easy to embrittle and the reliability of solder metal is not high;

a second object of the present application is to provide a method of making a preformed solder tab.

In order to achieve the first object, the present application adopts the following technical scheme:

a high-reliability preformed soldering lug comprises a core layer and a shell layer arranged on the periphery of the core layer, wherein a solid soldering flux core layer is embedded in a solder alloy layer to form a sandwich biscuit shape, so that the soldering flux can be well protected from being oxidized, the soldering flux does not need to be coated before brazing, the soldering flux does not need to be removed after brazing is finished, the manufacturing cost and the cavitation rate of a welded surface after welding are reduced, and the reliability of the soldering lug is improved;

the core layer is soldering flux and comprises the following components: 74-78wt% of unsaturated monomer modified rosin, 8-12wt% of activating agent, 5-8wt% of surfactant, 4.9-6.1wt% of thixotropic agent and 3.1-5.2wt% of antioxidant, and by using the unsaturated monomer modified rosin, the corrosiveness to a base material can be reduced, post-welding residues can be reduced, the wet performance of a soldering flux core layer can be greatly improved, and the overall strength and electrical performance of the soldering flux core layer can be improved;

the shell layer is solder alloy and comprises the following components: 89.1 to 93.7 weight percent of tin, 1.2 to 2.3 weight percent of silver, 0.2 to 1.2 weight percent of copper, 0.1 to 0.6 weight percent of indium, 0.5 to 0.8 weight percent of cerium, 0.1 to 0.6 weight percent of vanadium, 1.1 to 2.8 weight percent of lutetium, 1.8 to 2.8 weight percent of yttrium and 0.05 to 0.3 weight percent of zinc, the conductivity and the heat transfer property of the soldering lug can be improved by adding a small amount of rare earth elements lutetium, yttrium and cerium, the melting point of the soldering lug can be improved by adding indium, vanadium and zinc, the solidification and crystallization state of the soldering lug can be improved, and signal interference caused by metals can be avoided because magnetic materials such as lead elements, iron elements, cobalt elements, nickel elements and niobium elements are not added.

The unsaturated monomer is compounded by methacryloxypropyl trimethoxysilane (MEMO) and maleic anhydride, and the mechanical property, electrical property and light transmittance of rosin can be improved by adopting the unsaturated monomer methacryloxypropyl trimethoxysilane, particularly the wet state property of the rosin can be greatly improved, stronger permeability is provided for the rosin, the expansion rate of the soldering lug on a substrate can be improved, and the soldering lug has better wettability.

The ratio of the methacryloxypropyl trimethoxysilane to the maleic anhydride is 1-2:4-5.

The high reliability preformed soldering lug as described above, the activator is one or more of isopropylamine hydrobromide, triethanolamine hydrobromide, monoisopropanolamine and malic acid.

The thixotropic agent is a plurality of combinations of hydroquinone, dodecahydroxy stearic acid and modified hydrogenated castor oil, and the thixotropic agent is mutually matched to prevent the soldering lug from collapsing and play a role in preventing the phenomena of tailing, adhesion, collapse and the like in soldering.

The high-reliability preformed soldering lug is characterized in that the antioxidant is one or a combination of more of ethoxyquinoline, 2-ethyletherazole and methylbenzotriazole, so that the oxidation resistance of the soldering lug can be improved, the oxidation of tin materials is inhibited, and the occurrence of a pillow effect is reduced.

The high reliability preformed tab as described above, the surfactant is sodium dodecylbenzene sulfonate.

The high reliability preformed soldering lug as described above has an overall shape of square, round, arcuate, annular, frame or bar.

The high reliability preformed soldering lug as described above, the core layer thickness is 30-50 μm and the shell layer thickness is 0.3-0.8mm.

In order to achieve the second purpose, the application adopts the following technical scheme:

the method for preparing the high-reliability preformed soldering lug according to any one of the above, comprising the following steps:

s1, weighing the alloy components according to the weight percentage, and smelting;

s2, cooling the molten solution, and performing die casting molding in a die to obtain a solder shell for later use;

s3, adding rosin into a container, heating to 120-140 ℃, adding a surfactant after dissolving, and stirring until the surfactant is completely dissolved;

s4, maintaining the temperature at 120-140 ℃, adding the thixotropic agent, and stirring until the thixotropic agent is completely dissolved;

s5, cooling to 60-80 ℃, adding an antioxidant and an activator, and stirring for 40-60min to obtain a liquid soldering flux;

s6, cooling the liquid soldering flux to room temperature, and rolling and forming to obtain the solid soldering flux;

s7, embedding the solid soldering flux into a solder shell, and performing stamping forming to obtain the solder.

Compared with the prior art, the application has the following advantages:

1. the application provides a high-reliability preformed soldering lug, which comprises a core layer and a shell layer arranged on the periphery of the core layer, wherein a solid soldering flux core layer is embedded in a solder alloy layer to form a sandwich biscuit shape, so that the soldering flux can be well protected from being oxidized, the soldering flux does not need to be coated before soldering, the soldering flux does not need to be removed after soldering is finished, the manufacturing cost and the cavitation rate of a soldered surface after soldering are reduced, and the reliability of the soldering lug is improved; the shell of the solder alloy comprises tin, silver, copper, indium, cerium, vanadium, lutetium yttrium and zinc, the conductivity and the heat transfer property of the soldering lug can be improved by adding a small amount of rare earth elements lutetium, yttrium and cerium, the melting point of the soldering lug can be improved by adding indium, vanadium and zinc, the solidification and crystallization state of the soldering lug can be improved, and the signal interference caused by metals can be avoided because no magnetic materials such as lead element, iron element, cobalt element, nickel element and niobium element are added.

2. The flux is used as a core layer, the corrosiveness to a base material can be reduced, residues after welding can be reduced, the wet state performance of the flux core layer can be greatly improved, the overall strength and the electrical performance of the flux core layer can be improved, the mechanical performance, the electrical performance and the light transmittance of the rosin can be improved by adopting the unsaturated monomer methacryloxypropyl trimethoxy silane, particularly the wet state performance of the rosin can be greatly improved, stronger permeability is provided for the rosin, the expansion rate of a soldering lug on a substrate can be improved, and the soldering lug has better wetting performance.

3. According to the preparation method of the high-reliability preformed soldering lug, the soldering flux inner core layer and the solder alloy shell are prepared successively, and then the soldering flux inner core layer is embedded into the alloy shell, so that the process is simple and convenient, the reaction is mild, no harmful gas is generated in the process, and the preparation method is suitable for mass production.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the description of the embodiments will be briefly described below.

FIG. 1 is a cross-sectional view of a high reliability preformed solder tab of the present application.

Detailed Description

The technical scheme of the application is described below with reference to examples 1 to 5.

Example 1

A high-reliability preformed soldering lug, which comprises a solder alloy shell layer 2 and a soldering flux inner core layer 1, wherein the component proportion of the solder alloy layer 2 is shown in table 1, the component proportion of the soldering flux is shown in table 2, and the preparation method comprises the following steps:

weighing the components according to the weight percentages of the table 1 and the table 2 for standby, and smelting the solder alloy in the table 1; cooling the melted solution, and performing die casting molding in a mold to obtain a solder shell for later use;

adding unsaturated monomer modified rosin into a container according to table 2, heating to 120 ℃, adding a surfactant after dissolution, and stirring until complete dissolution; maintaining the temperature at 120 ℃, adding the thixotropic agent, and stirring until the thixotropic agent is completely dissolved; cooling to 60 ℃, adding an antioxidant and an activator, and stirring for 40min to obtain a liquid soldering flux; cooling the liquid soldering flux to room temperature, and rolling and forming to obtain solid soldering flux; embedding the solid soldering flux into a solder shell, and performing stamping forming to obtain the solder.

Example 2

A high-reliability preformed soldering lug, which comprises a solder alloy shell layer 2 and a soldering flux inner core layer 1, wherein the component proportion of the solder alloy layer 2 is shown in table 1, the component proportion of the soldering flux is shown in table 2, and the preparation method comprises the following steps:

weighing the components according to the weight percentages of the table 1 and the table 2 for standby, and smelting the solder alloy in the table 1; cooling the melted solution, and performing die casting molding in a mold to obtain a solder shell for later use;

adding unsaturated monomer modified rosin into a container according to table 2, heating to 130 ℃, adding a surfactant after dissolution, and stirring until complete dissolution; maintaining the temperature at 130 ℃, adding thixotropic agent, and stirring until the thixotropic agent is completely dissolved; cooling to 70deg.C, adding antioxidant and activator, and stirring for 50min to obtain liquid flux; cooling the liquid soldering flux to room temperature, and rolling and forming to obtain solid soldering flux; embedding the solid soldering flux into a solder shell, and performing stamping forming to obtain the solder.

Example 3

A high-reliability preformed soldering lug, which comprises a solder alloy shell layer 2 and a soldering flux inner core layer 1, wherein the component proportion of the solder alloy layer 2 is shown in table 1, the component proportion of the soldering flux is shown in table 2, and the preparation method comprises the following steps:

weighing the components according to the weight percentages of the table 1 and the table 2 for standby, and smelting the solder alloy in the table 1; cooling the melted solution, and performing die casting molding in a mold to obtain a solder shell for later use;

adding unsaturated monomer modified rosin into a container according to table 2, heating to 140 ℃, adding a surfactant after dissolution, and stirring until complete dissolution; maintaining the temperature at 140 ℃, adding the thixotropic agent, and stirring until the thixotropic agent is completely dissolved; cooling to 80deg.C, adding antioxidant and activator, and stirring for 60min to obtain liquid flux; cooling the liquid soldering flux to room temperature, and rolling and forming to obtain solid soldering flux; embedding the solid soldering flux into a solder shell, and performing stamping forming to obtain the solder.

Example 4

A high-reliability preformed soldering lug, which comprises a solder alloy shell layer 2 and a soldering flux inner core layer 1, wherein the component proportion of the solder alloy layer 2 is shown in table 1, the component proportion of the soldering flux is shown in table 2, and the preparation method comprises the following steps:

weighing the components according to the weight percentages of the table 1 and the table 2 for standby, and smelting the solder alloy in the table 1; cooling the melted solution, and performing die casting molding in a mold to obtain a solder shell for later use;

adding unsaturated monomer modified rosin into a container according to table 2, heating to 140 ℃, adding a surfactant after dissolution, and stirring until complete dissolution; maintaining the temperature at 140 ℃, adding the thixotropic agent, and stirring until the thixotropic agent is completely dissolved; cooling to 80deg.C, adding antioxidant and activator, and stirring for 60min to obtain liquid flux; cooling the liquid soldering flux to room temperature, and rolling and forming to obtain solid soldering flux; embedding the solid soldering flux into a solder shell, and performing stamping forming to obtain the solder.

Example 5

A high-reliability preformed soldering lug, which comprises a solder alloy shell layer 2 and a soldering flux inner core layer 1, wherein the component proportion of the solder alloy layer 2 is shown in table 1, the component proportion of the soldering flux is shown in table 2, and the preparation method comprises the following steps:

weighing the components according to the weight percentages of the table 1 and the table 2 for standby, and smelting the solder alloy in the table 1; cooling the melted solution, and performing die casting molding in a mold to obtain a solder shell for later use;

adding unsaturated monomer modified rosin into a container according to table 2, heating to 140 ℃, adding a surfactant after dissolution, and stirring until complete dissolution; maintaining the temperature at 140 ℃, adding the thixotropic agent, and stirring until the thixotropic agent is completely dissolved; cooling to 80deg.C, adding antioxidant and activator, and stirring for 60min to obtain liquid flux; cooling the liquid soldering flux to room temperature, and rolling and forming to obtain solid soldering flux; embedding the solid soldering flux into a solder shell, and performing stamping forming to obtain the solder.

Table 1: component weight ratio of solder alloy powder of examples 1 to 5

Component (A)	Example 1	Example 2	Example 3	Example 4	Example 5
						Tin (Sn)	89.10％	90.20％	91.50％	92.60％	93.70％
Silver (Ag)	2.30％	2.20％	2.00％	1.50％	1.20％
						Copper (Cu)	1.20％	1.10％	1.00％	0.80％	0.70％
Indium (indium)	0.10％	0.60％	0.50％	0.30％	0.60％
						Cerium (Ce)	0.80％	0.80％	0.60％	0.50％	0.70％
Vanadium (V)	0.60％	0.60％	0.40％	0.20％	0.10％
						Lutetium (lutetium)	2.80％	1.80％	1.80％	1.20％	1.10％
Yttrium	2.80％	2.40％	2.00％	2.70％	1.80％
						Zinc alloy	0.30％	0.30％	0.20％	0.20％	0.10％

Table 2: the proportions by weight of the components of the fluxes of examples 1 to 5

The high reliability preformed tabs obtained in examples 1-5 were subjected to performance testing, the test results are shown in Table 3:

table 3: test results of examples 1-5 and comparative examples

As can be seen from the table, the application provides the high-reliability preformed soldering lug which comprises a core layer and a shell layer arranged on the periphery of the core layer, wherein the solid soldering flux core layer is embedded in the solder alloy layer to form a sandwich biscuit shape, so that the soldering flux can be well protected from being oxidized, the soldering flux does not need to be coated before re-soldering, the soldering flux does not need to be removed after the soldering is finished, the manufacturing cost and the cavitation rate of a soldered surface after soldering are reduced, and the reliability of the soldering lug is improved; the shell of the solder alloy comprises tin, silver, copper, indium, cerium, vanadium, lutetium yttrium and zinc, the conductivity and the heat transfer property of the soldering lug can be improved by adding a small amount of rare earth elements lutetium, yttrium and cerium, the melting point of the soldering lug can be improved by adding indium, vanadium and zinc, the solidification and crystallization state of the soldering lug can be improved, and the signal interference caused by metals can be avoided because no magnetic materials such as lead element, iron element, cobalt element, nickel element and niobium element are added.

The foregoing description of the preferred embodiments of the application is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the application.

Claims (8)

1. A high-reliability preformed soldering lug, which is characterized by comprising a core layer (1) and a shell layer (2) arranged on the periphery of the core layer;

the core layer (1) is a soldering flux and comprises the following components in percentage by weight: 74-78wt% of unsaturated monomer modified rosin, 8-12wt% of activating agent, 5-8wt% of surfactant, 4.9-6.1wt% of thixotropic agent and 3.1-5.2wt% of antioxidant;

the shell layer (2) is a solder alloy and comprises the following components in percentage by weight: 89.1-93.7wt% tin, 1.2-2.3wt% silver, 0.2-1.2wt% copper, 0.1-0.6wt% indium, 0.5-0.8wt% cerium, 0.1-0.6wt% vanadium, 1.1-2.8wt% lutetium, 1.8-2.8wt% yttrium, and 0.1-0.3wt% zinc;

the unsaturated monomer is compounded by methacryloxypropyl trimethoxy silane and maleic anhydride;

the weight ratio of the methacryloxypropyl trimethoxy silane (MEMO) to the maleic anhydride is 1-2:4-5.

2. The high reliability preformed solder tab of claim 1, wherein: the activator is one or more of isopropylamine hydrobromide, triethanolamine hydrobromide, monoisopropanolamine and malic acid.

3. The high reliability preformed solder tab of claim 1, wherein: the thixotropic agent is a plurality of combinations of hydroquinone, dodecahydroxystearic acid and modified hydrogenated castor oil.

4. The high reliability preformed solder tab of claim 1, wherein: the antioxidant is one or a combination of more of ethoxyquinoline, 2-ethyl ether azole and methyl benzotriazole.

5. The high reliability preformed solder tab of claim 1, wherein: the surfactant is sodium dodecyl benzene sulfonate.

6. The high reliability preformed solder tab of claim 1, wherein: the high-reliability preformed soldering lug is square, round, arc-shaped, annular, frame-shaped or strip-shaped in overall shape.

7. The high reliability preformed solder tab of claim 1, wherein: the thickness of the core layer (1) is 30-50 mu m, and the thickness of the shell layer (2) is 0.3-0.8mm.

8. A method of making a high reliability preformed solder tab according to any of claims 1-7 comprising the steps of:

s1, weighing the alloy components according to the weight percentage, and smelting;

s2, cooling the molten solution, and performing die casting molding in a die to obtain a solder shell for later use;

s3, adding rosin into a container, heating to 120-140 ℃, adding a surfactant after dissolving, and stirring until the surfactant is completely dissolved;

s4, maintaining the temperature at 120-140 ℃, adding the thixotropic agent, and stirring until the thixotropic agent is completely dissolved;

s5, cooling to 60-80 ℃, adding an antioxidant and an activator, and stirring for 40-60min to obtain a liquid soldering flux;

s6, cooling the liquid soldering flux to room temperature, and rolling and forming to obtain the solid soldering flux;

s7, embedding the solid soldering flux into a solder shell, and performing stamping forming to obtain the solder.