Leadless soft soldering material and manufacturing method

Abstract

The invention discloses a lead-free soft soldering. Calculated by weight percentage, the lead-free soft soldering consists of following compositions: 0.1 to 3.9 per cent of Al, 0.0001 to 0.5 per cent of Se and rest of Sn. The method of manufacturing the invention is: (a) after refined tin is added into a plumbago pot to be melted, temperature rises to 1100 DEG C. refined copper is added and evenly mixed. The refined tin and the refined copper are melted to be liquid tin copper alloy. The liquid tin and copper alloy becomes the alloy ingot of tin and copper after standing for 30 minutes; (b) the refined Ag is added and melted again and the temperature rises to above 1600 DEG C. Pure nickel is added and melted. The liquid Ag and nickel becomes the alloy ingot of Ag and selenium after standing for 30 minutes; (c) with the refined tin added into and melted and the temperature rising to above 600 to 1000 DEG C, covering agent is added to isolate the liquid level of tin from oxygen in the air. Pure selenium is added and melted. The liquid tin and selenium becomes the alloy ingot of tin and selenium after standing for 30 minutes; (d) three gold ingots, Ga or Cu and the rest of tin and put into a stainless steel kettle to be melted according to the required formulation, which can be made into a tin wire, a tin bar and a tin ball.

Description

technical field [0001] The invention relates to a preparation method of lead-free solder, which belongs to soldering materials. Background technique [0002] In recent years, with the rapid development of electronic products and the enhancement of human awareness of environmental protection, although traditional leaded solder has the advantages of excellent wettability, solderability, good mechanical properties and low price, the heavy metal lead in leaded solder After PCB is soldered, it will be scattered in the environment along with discarded electronic products. After long-term corrosion by acid rain, lead will seep into the ground and dissolve into the groundwater system. After drinking, it will accumulate in the body of humans or animals for a long time, which will cause lead poisoning and harm It affects the health of people and animals, and because people realize the importance of protecting the environment, environmental laws and regulations are becoming more and mo...

AI Technical Summary

Problems solved by technology

[0002] In recent years, with the rapid development of electronic products and the enhancement of human awareness of environmental protection, although traditional leaded solder has the advantages of excellent wettability, solderability, good mechanical properties and low price, the heavy metal lead in leaded solder After PCB is soldered, it will be scattered in the environment along with discarded electronic products. After long-term corrosion by acid rain, lead will seep into the ground and dissolve into the groundwater system. After drinking, it will accumulate in the body of humans or animals for a long time, which will cause lead poisoning and harm It affects the health of people and animals, and because people realize the importance of protecting the environment, environmental laws and regulations are becoming more and more perfect and strict.