FLUX FOR LOW-TEMPERATURE SOLDERING Russian patent published in 2021 - IPC B23K35/363 

FIELD: chemistry.

SUBSTANCE: invention relates to compositions of fluxes with increased thermal resistance, not containing alkalis and acids, intended for low-temperature soldering in the temperature range of 150 to 350°C in air. The soldering flux comprises an activator, saccharides, a solvent and a thixotropic agent. As an activator, the flux comprises sodium or potassium carbonates, and the saccharides additionally comprise rebaudioside A, at the following ratio of components, % wt.: activator 1.6 to 3.1, saccharides 9 to 14, thixotropic agent up to 0.01, solvent the rest.

EFFECT: flux allows to solder low heat conductive materials, such as low-temperature co-firing ceramics, metallised silver paste (hereinafter - LTCC), while maintaining fluxing properties throughout the entire process and removing flux residue with deionised water.

1 cl, 2 tbl