Low-silver lead-free solder alloy and preparation method and device thereof

A lead-free solder alloy and molten alloy technology, applied in the field of alloys, can solve the problems of insufficient wettability and too fast copper dissolution, and achieve the effects of good wettability and oxidation resistance, low copper dissolution rate and reduction of oxidation.

Inactive Publication Date: 2011-04-27
GUANGZHOU RES INST OF NON FERROUS METALS
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to address the above-mentioned problems and deficiencies, to provide a low-silver lead-free solder with low copper solubility and good wettab

Method used

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  • Low-silver lead-free solder alloy and preparation method and device thereof
  • Low-silver lead-free solder alloy and preparation method and device thereof
  • Low-silver lead-free solder alloy and preparation method and device thereof

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preparation example Construction

[0024] The present invention also provides a method for preparing low-silver lead-free solder alloy, comprising the following steps:

[0025] (1) Melting the ingredient elements for preparing the low-silver lead-free solder alloy into a molten alloy;

[0026] (2) Casting the molten alloy into a vibrating mold with a circulating coolant inside, and the obtained ingot has a fine structure, low copper dissolution rate and good wettability as described in the present invention. Low silver lead-free solder alloy.

[0027] Among them, in the above step (1), one or more of Cu or Cu and other component elements (also called intermediate elements or additive elements) other than Ag and Sn are first smelted in a vacuum melting furnace to form an intermediate alloy, and then melt the prepared master alloy, Ag, Sn and other alloying elements at a suitable temperature into a molten alloy in a conventional crucible melting furnace.

[0028] In the above step (2), the mold is first fixed o...

Embodiment 1

[0032] Example 1: The present embodiment low-silver lead-free solder is made up of the composition of following percentage by weight:

[0033] 0.8% of Ag, 0.5% of Cu, 3.0% of Bi, 0.04% of Ni, and the balance being Sn.

[0034] The preparation process is as follows:

[0035] (one). Melt Cu and Ni in a vacuum smelting furnace to prepare an intermediate alloy, and the vacuum degree of the vacuum smelting furnace is 10 -5 Pa, the melting temperature range is 450-850°C, the stirring time is about 30 minutes, and the melting time is 2 hours.

[0036] (two). Melt Sn in a crucible melting furnace at 400°C until it is fully melted, add Bi block, Ag grains and the intermediate alloy refined in step (1) into Sn according to the proportion for melting, the melting temperature is 450°C, and the melting time is 2 hours , Stir for 40 minutes until the alloy composition is uniform.

[0037] (three). Assemble the mold 2, the cooling system and the vibrating table 1, start the vibrating ...

Embodiment 2

[0039] The present embodiment low-silver lead-free solder is made up of the composition of following percentage by weight:

[0040] 0.7% Cu, 0.05% Ni, 0.03% Ge, 0.06% mixed rare earth (RE), 0.02% Ag, and the balance is Sn.

[0041] The preparation process is as follows:

[0042] (one). The master alloy of Cu, Ge, Ni and RE is melted and prepared in a vacuum melting furnace, and the vacuum degree of the vacuum melting furnace is 10 -5 Pa, the melting temperature range is 450~850°C, the stirring time is 40 minutes, and the melting time is 1-2 hours.

[0043] (two). Melt Sn in a crucible melting furnace at 500°C until fully melted, add the master alloy and Ag refined in step (1) into Sn in proportion to melt, the melting temperature is 550°C, and the constant temperature melting time is 1 hour. In order to reduce the burning loss during the smelting of rare earth components, a mixed salt is used to protect and reduce oxidation during smelting. After the alloy is completely m...

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Abstract

The invention relates to a low-silver lead-free solder alloy and a preparation method and a used device thereof. The low-silver lead-free solder alloy consists of the following components in percentage by weight: more than 0 and less than or equal to 1 percent of Ag, 0.2 to 1 percent of Cu, 0 to 59 percent of Bi, 0 to 0.07 percent of Ni, 0 to 0.7 percent of Sb, 0 to 0.06 percent of Ge, 0 to 1 percent of Ga, 0 to 0.1 percent of RE and the balance of Sn. The solder prepared by the invention does not contain harmful metal Pb and meets the national requirement of electronic packaging environmental-friendly use; in addition, the quick cooling and vibration combined preparation method is adopted, so that the melting range is effectively reduced, the alloy is quickly solidified, structure non-uniformity is improved, component uniformity and structure refinement are ensured while oxidation is reduced, and a product has the characteristics of fine structure, low copper dissolution rate and high wettability and oxidation resistance.

Description

technical field [0001] The invention relates to an alloy, in particular to a low-silver lead-free solder alloy and a preparation method and device thereof. Background technique [0002] At present, lead (Pb) and other biotoxic elements in tin solders for electronic assembly are banned by legislation in various countries in the world. At present, tin-silver-copper alloys are used to replace traditional tin-lead solders. Lead-free solder is widely used in the manufacture of consumer electronics products. Generally, it can be divided into high-silver (Ag in the alloy weight percentage > 1%) lead-free solder and low-Ag lead-free solder (Ag in the alloy The weight percentage in ≤1%). Solder with high Ag content such as SAC305 occupies a dominant position in the market due to its excellent soldering process performance and years of industrial promotion. However, in recent years, the upgrading of electronic assembly products has been accelerated, and the market competition is...

Claims

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Application Information

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IPC IPC(8): B23K35/26C22C13/00
Inventor 张宇鹏杨凯珍许磊易江龙刘师田刘正林房卫萍
Owner GUANGZHOU RES INST OF NON FERROUS METALS
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