SOLDER PASTE Russian patent published in 2012 - IPC B23K35/36 B23K35/363 B23K35/26 

FIELD: chemistry.

SUBSTANCE: paste can be used for surface mounting of radio components and integrated circuits on printed-circuit boards to obtain soldered joints for operation in severe operating conditions. The solder paste contains 80-91 wt % solder alloy powder and 9-20 wt % fluxing agent. Components of the fluxing agent are in the following ratio, wt %: modified colophony based n natural components 30-60, mixture of organic solvents in form of fatty acids and fatty ethers 35-70, activators in form of a mixture of organic acids 1-8. All substances are environmentally safe, based on natural biodegradable material which is environmentally safe, have a very weak smell or have no smell altogether, do not contain halogens, surfactants, synthetic polymers (resin) and water.

EFFECT: in the soldered joint, fluxing agent remains contain a minimum amount of ions, which ensures high surface electrical resistance for a long period of time.

6 dwg, 4 tbl, 1 ex