METHOD OF SOLDER PASTE PREPARATION FOR SOLDERING IN REDUCING ATMOSPHERE Russian patent published in 2008 - IPC B23K35/40 B23K35/24 

FIELD: technological processes.

SUBSTANCE: initially powdered iron-copper component is mixed with organic binder and water in double-shaft Z-shaped mixer for 4-6 hours with preparation of suspension. Then surface-active substances are introduced into suspension and, as activating substance, ammonia tetrafluoroborate with subsequent mixing of all charge components in vertical mixer with gate stirrer for 2-4 hours. Prepared suspension is ground to provide fineness of hard component of charge of not more than 4 micrometer.

EFFECT: increase of soldered joint strength and quality of prepared paste.

4 cl