Low-melting-point and high-hardness lead-free solder and preparation method thereof

Abstract

The invention relates to a low-melting-point and high-hardness lead-free solder and a preparation method thereof. The low-melting-point and high-hardness lead-free solder is prepared from the following raw materials in percentage by weight: 5 to 8 percent of Zn, 30 to 40 percent of Bi, 0.2 to 0.5 percent of Mg, 0.1 to 0.2 percent of In, 0.01 to 0.015 percent of grapheme, and the balance being Sn and inevitable impurities. According to the low-melting-point and high-hardness lead-free solder disclosed by the invention, by optimizing components of the raw materials and adding the Mg and the grapheme, the hardness of the solder is effectively improved, a melting point is reduced, and the solder is enabled to have good welding performance.

Description

technical field

[0001] The invention relates to a lead-free solder with low melting point and high hardness and a preparation method thereof, belonging to the field of magnesium alloy welding materials. Background technique

[0002] The traditional solder in the past is tin-lead solder, which has been widely used in the past because of its low melting point, excellent solderability, and low cost. With the rapid development of electronic technology, the replacement time of electronic products is shortened day by day, resulting in a large amount of electronic product waste. Printed circuit boards, removed from disassembled electronics, are often shredded and buried in the ground. If the rainwater seeps into the ground and touches the buried electronic circuit board, the lead in the tin-lead solder will be separated in an ion state and enter rivers, lakes, etc., polluting water sources. If you drink water containing lead for a long time, lead will be deposited in the body, ev...