| 摘要 |
PURPOSE:To improve the sound quality of audio apparatus by using the solder produced by melting Cu which attains temp. higher than a saturation point at the melting temp. in the working stage and soldering the work in the molten solder on which intermetallic compds. of Cu are held afloat. CONSTITUTION:For example, a compsn. consisting of 63wt% Sn, 0.7wt% Cu at which it attains temp. higher than the saturated point at the melting temp. in the working stage and the balance Pb is melted uniformly at about 400 deg.C and is cooled, whereby a solder ingot is produced. When such solder ingot is charged into a soldering vessel 2 and is heated and melted to about 250-260 deg.C, intermetallic compds. 1 such as Sn and Cu, Pb and Cu, Sn, Pb and Cu float in the molten solder 3. The work is welded by such solder. |
