Patent ID: 8444774

Claim:
A composition of matter comprising a flux, wherein said flux consists essentially of a combination of: (a) a fluxing agent; and (b) a solvent; wherein said fluxing agent: (1) comprises a keto acid; or (2) comprises an ester acid; or (3) comprises a mixture of said keto acid with said ester acid; and wherein said solvent comprises a mixture of a tacky solvent selected from polyhydric alcohols or mixtures thereof, and a non-tacky solvent selected from monohydric alcohols or mixtures thereof; where said flux composition consists essentially of a combination of: (a) a fluxing agent; and (b) a solvent; wherein said fluxing agent: (1) comprises a keto acid; or (2) comprises an ester acid; or (3) comprises a mixture of said keto acid with said ester acid; and wherein said solvent consists essentially of a tacky solvent and a non-tacky solvent (1) wherein said tacky solvent is selected from ethoxylated glycerol, propoxylated glycerol, or mixtures thereof; (2) said non-tacky solvent is selected from methanol, ethanol, 2-propanol, 1-methoxy-2-propanol, 2-methoxyethanol, 2-ethoxyethanol, 3-ethoxy 1 -propanol, 2-butoxyethanol, ethylene glycol butyl ether, propylene glycol propyl ether, di(propylene glycol) propyl ether, di(propylene glycol) methyl ether, ethyl acetate, acetone, methyl ethyl ketone or mixtures thereof; and wherein said keto acid or ester acid or the mixtures thereof are present in an amount comprising from about 6 weight % to about 15 weight %, said tacky solvent in an amount comprising from about 50 weight % to about 80 weight %, and said non-tacky solvent in an amount comprising from about 10 weight % to about 30 weight %, all based on the weight of said flux composition.