Lead-free low-temperature solder and preparation method thereof

Abstract

The invention belongs to the technical field of solder, and particularly relates to a lead-free low-temperature solder. The solder comprises, by mass, 0.001-58.0% of bismuth, 0.001-1.0% of silver, 0.001-2.0% antimony, 0.001-0.1% of indium, 0.001-0.15% of phosphorus, 0.001-0.08% of germanium, 0.001-0.015% of beryllium, 0.001-0.015% of cerium and the balance tin. Compared with the prior art, when welding is carried out at the temperature of 139DEG C to 200DEG C, little oxidation slag is generated, the surface of a tin furnace can be kept bright basically without oxidation at the temperature, thesolder can not be oxidized within 50 seconds at 200-260 DEG C, so that the welding efficiency is greatly improved, and the damage to electronic components of a PCBA board is reduced; the low-temperature solder is good in oxidation resistance; and in the welding process, compared with a common Sn-Ag-Cu system, the solder has fewer welding defects, the surfaces of welding spots are very light-bright, the welding spots are full, continuous welding does not occur, so that the welding quality is effectively improved, and the solder and the method are environment-friendly and safe.

Description

technical field

[0001] The invention belongs to the technical field of solder, and in particular relates to a lead-free low-temperature solder and a preparation method thereof. Background technique

[0002] The implementation of lead-free solder in the electronics industry is a general trend. The academic circles and the industry have recognized the performance of lead-free alloys represented by Sn-Ag-Cu in terms of soldering quality and long-term reliability. However, in high-density information equipment and portable equipment, low-temperature mounting technology is required for multilayering of substrates or embedding of devices. In addition, low-temperature soldering is required for soldering of heat-resistant components, lightning protection equipment, temperature-sensitive device equipment, LED lighting industry, low-temperature operation and other environments, instead of Sn-Ag-Cu high melting point solder. Therefore, low-temperature lead-free solder came into being....