Preparation method of anaerobic tin based solder alloy

Abstract

The invention belongs to the field of soft solder for soft solder welding in electronic industry, and in particular relates to a preparation method of an anaerobic tin based solder alloy. The method comprises the following steps of: (1) melting tin and alloy materials in a melting furnace, blowing, stirring and refining nitrogen and a hexachloroethane refining agent for 30-40 minutes, then standing for 15-20 minutes, and skimming the surface floating scruff, wherein the hexachloroethane refining agent accounts for 0.1-0.2% of the total weight of melt; (2) guiding a tin alloy liquid in the melting furnace into a temperature preservation furnace of 350-380 DEG C, introducing protective nitrogen, and guiding the tin alloy liquid by a traction rod through a crystallizer by a traction machine, wherein the water inlet temperature of cooling water in the crystallizer is 20-25 DEG C, and the water outlet temperature is 30-35 DEG C, and the traction speed is 0.3-0.5m / min; and (3) carrying out secondary spraying and cooling after traction instantly, thus the temperature of a rod blank is reduced to 30-50 DEG C, thereby obtaining a finished product finally. According to the invention, the tin based solder alloy which has high purity, is uniform in component, and has the oxygen content within 10ppm can be prepared, the production process is stable, and the continuous scale production can be realized.

Description

technical field [0001] The invention belongs to the field of solder used for soldering in the electronics industry, and in particular relates to a preparation method of an oxygen-free tin-based solder alloy. Background technique [0002] With the rapid development of the electronics industry, the amount of tin solder is increasing. There are no more than two methods for preparing tin-based solder products currently used in the electronics industry, one is the pouring method and the other is the extrusion method. Most of the pouring method is manual pouring, that is, the operator uses a container to scoop out the tin on the surface of the tin liquid and then injects it into the mold. The cooling process is completely exposed to the air. On the one hand, the gas and impurities will float to the liquid surface after the tin liquid stands still. , the method of taking liquid from the surface inevitably mixes gas and impurities into the product. On the other hand, the crystalliz...

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Problems solved by technology

Most of the pouring method is manual pouring, that is, the operator uses a container to scoop out the tin on the surface of the tin liquid and then injects it into the mold. The cooling process is completely exposed to the air. On the one hand, the gas and impurities will float to the liquid surface after the tin liquid stands still. , the method of taking liquid from the surface inevitably mixes gas and impurities into the product. On the other hand, the crystallization process of the product is completely exposed to the air, and a new oxide film will be formed on the surface of the product, which will lead to an increase in the oxygen content of the product. Not conducive to subsequent use

The extrusion method is carried out by first casting the ingot and then extruding it through the extruder, but the oxide film on the surface of the tin ingot will enter the product during the extrusion process, increasing the oxygen content.

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