Abstract: A brazing joint, a brazing method, and a device for promoting solder rheology and gas overflow are provided. The brazing joint includes a first base metal, a second base metal, and a brazing seam located therebetween. The brazing seam is formed by filling a solder in a gap formed by welding surfaces of the first and the second base metal and melting it to connect the first and the second base metal. The brazing seam is a concave-shaped brazing seam. The gap defines a first distance and a second distance, the first distance is located at an edge of the gap, the second distance is located at the edge or an inside of the gap, the first distance is greater than the second distance, and a curved surface is formed between the location of the first distance and the location of the second distance for transition.

Abstract: The application relates to a low-silver solder for welding an electric vacuum device and a preparation method thereof, The low-silver solder for welding the electric vacuum device is characterized by consisting of Ag, Cu, Ni and a trace element R, wherein the low-silver solder comprises the following components in percentage by mass: 65-71% of Ag, 0-0.1% of Ni, 0-0.1% of trace element R and the balance of Cu; the trace element R consists of one or more of P, Sc, Be, Zr and La.