Hydrocarbon fluxes for ionic compound free soldering

Abstract

PurposeThe purpose of this paper is to develop a new ionic compound free soldering process.Design/methodology/approachThe ability of hydrocarbons including 9,10‐dihydroanthracene, eicosane, 2,6,10,14‐tetramethylpentadecane, cyclooctane, and dicyclopentadiene to reduce cuprous or cupric oxide was investigated. The applicability of hydrocarbons as ion free flux reagents was experimentally examined. The hydrocarbons were applied to the soldering of pre‐oxidized copper electrodes under practical conditions.FindingsA 9,10‐dihydroanthracene was found to be efficient at reducing cuprous or cupric oxide powder under an argon atmosphere at 300°C for 2 min. The high‐reducing ability of the hydrocarbon is in agreement with the low‐homolytical C−H bond dissociation energy calculated based on the density functional theory. A 9,10‐dihydroanthracene was shown, by the highest soldering efficiency and sufficient reliability in the environmental testing, to be applicable as an ion‐free soldering flux.Originality/valueThe findings of this paper suggest a new method for an ionic compound free soldering process.