SOLDER FOR FLUX-FREE SOLDERING AND METHOD FOR ITS MANUFACTURE Russian patent published in 2017 - IPC B23K35/26 B23K35/40 

FIELD: metallurgy.

SUBSTANCE: invention can be used to produce permanent joints of dissimilar materials by soldering diffusion-hardening solders on gallium base. Upon receipt of the solder, indium is introduced into the gallium melt and the resulting melt is introduced with a filler in the form of copper powder with a particle size of 25-40 microns. Before introduction into the melt, the copper powder is treated with hydrochloric acid (counter-etched), and its particles are covered with a layer of silver. The content of components is selected from the conditions of solder obtaining of the following composition, wt %: gallium 50-60, indium 10-15, copper powder being the rest.

EFFECT: invention allows to solder powerful electronic components, particularly crystals of monolithic integrated circuits, onto the heat-removing bases at room temperature and contact pressure.

2 cl