Soft solder paste for soldering electronic device under protective gas - contg synthetic hydrocarbon resin with low acid no which does not leave corrosive residue, in contrast to rosin-based solder.

摘要

Soft solder paste for soldering electronic components and circuits under protective gas (I), esp N2 (IA) with a low residual O2 content, consists of a soft solder powder, an organic resin (II), a flux and a solvent, (II) being a synthetic hydrocarbon resin with acid no less than 50 and softening point 50-150 deg C. (II) is pref a satd aliphatic hydrocarbon resin. USE/ADVANTAGE - The paste is used for soldering electronic circuits under (I), esp (IA) (claimed). The paste is free from rosin and the residues left after soldering do not cause corrosion, hence need not be washed off. In an example, a resin flux system for a solder paste used under (I) was prepd from 41.00 pts hydrocarbon resin ('Arkon P199'; RTM), 46.50 pts isohexadecyl alcohol, 3.75 pts adipic acid, 3.75 pts suberic acid and 5.00 pts thixotropic agent. A solder paste was prepd by mixing 100 g of this mixt with 900 g solder powder (Sn63Pb alloy; particle size 20-40 microns). This was melted on a Cu-coated ceramic in (IA).