Abstract: A flux consisting of, (i) 30 to 80 wt. % of one or more acidic resins, (ii) 10 to 60 wt. % of at least one organic solvent, (iii) 0 to 15 wt. % of one or more amines, and (iv) 0 to 20 wt. % of one or more components other than components (i) to (iii), wherein the flux undergoes a weight loss of ?50 wt. % upon reaching a temperature of 280° C. during a thermogravimetric analysis carried out in the range from 25 to 350° C. at a heating rate of 10 K/min and with the addition of synthetic air; and solder paste consisting of 80 to 92 wt. % of one or more different solders and 8 to 20 wt. % of the flux.

Abstract: A flux, consisting of: (i) 30 to 80 wt. % of one or more acidic (meth)acrylic copolymers having an acid number in the range from 100 to 350 mg KOH/g and having a weight-average molecular weight Mw in the range from 1000 to 5000; (ii) 10 to 60 wt. % of at least one organic solvent; (iii) 0 to 15 wt. % of one or more amines; and, (iv) 0 to 20 wt. % of one or more components other than components (i) to (iii); and solder paste consisting of 80 to 92 wt. % of one or more different solders and 8 to 20 wt. % of the flux.

Abstract: A flux consisting of: (i) 30 to 80 wt % of one or more different acidic oligoesters having an acid number in the range from 100 to 300 mg KOH/g and having a weight-average molecular weight Mw in the range from 300 to 600, (ii) 10 to 50 wt % of at least one organic solvent, (iii) 0 to 15 wt % of one or more amines, and (iv) 0 to 10 wt % of one or more components other than components (i) to (iii); and, solder paste consisting of 80 to 92 wt % of one or more different solders and 8 to 20 wt % of the flux.