METHOD FOR CLEANING OF SOLDER MADE AS FOIL OR TAPE BEFORE SOLDERING Russian patent published in 2018 - IPC B23K1/20 B08B3/12 

FIELD: chemistry.

SUBSTANCE: in the first bath of the ultrasound complex degreasing is carried out at a temperature of 180-200°C for 5-7 minutes with a detergent containing, wt %: KOH or NaOH alkali 15-25, glycerine 50-60, water - the rest. In the second bath, purification is carried out at a temperature of 50-60°C for 3-5 min with deionized water. In the third bath - at a temperature of 60-70°C for 20-30 minutes with detergent containing, wt %: KOH or NaOH alkali 3-4, sodium soda Na₂CO₃ 3-3.5, surfactant-syntanol 0.25-0.35, water - the rest, at a temperature of 60-70°C for 20-30 minutes. In the fourth bath, purification is carried out with deionized water at a temperature of 60-70°C for 2-3 min. In the fifth bath, purification is carried out in acetone at a room temperature for 2-3 minutes with ultrasound applied followed by drying with hot air.

EFFECT: invention provides complete removal of lubricated liquid residues rolled after hot rolling from the surface of gold-containing low-temperature eutectic solders.

1 tbl