Patent ID: 6786391
Filing Date: 2004-09-07
Classification: B23K,H05K

Abstract:
A method of controlling solder deposition on base metal utilizing two fluxes and preformed solder comprising:a) applying an effective amount of an attaching flux to a base metal or substrate wherein the attaching flux may cause the formation of harmful, insoluble, or corrosive residues on the base metal or substrate if it is allowed to remain on the base metal or substrate after being subjected to heated reflow conditions, b) placing a preform on the substrate containing an effective amount of the attaching flux, c) applying an effective amount on a finishing flux onto the preform that can effectively solubilize harmful, insoluble or corrosive residues that may remain on the base metal or substrate after being subjected to heated reflow conditions, d) subjecting the substrate, flux and preform to heated reflow conditions, to form a solder deposit, e) drying the cleaned substrate and solder deposit.