Study on Cold Hardening and Recrystallization Temperature of Cu-Ni-Sn-P Alloy for Integrated Circuit Lead Frame

Abstract

The work hardening curve of the Cu-Ni-Sn-P alloy for the integrated circuit lead frame was drawn by different degrees of cold deformation. The recrystallization temperature of the alloy was determined by testing the tensile strength, Vickers hardness, elongation, and electrical conductivity of the samples annealed at different temperatures and microstructure observation. The results show that the Cu-Ni-Sn-P alloy had obvious work hardening characteristics after being deformed by cold rolling; the tensile strength of the alloy showed a trend of first increasing and then tending to be stable with the increase of the working rate, while the elongation and electrical conductivity showed the opposite changing law. At the same annealing time, with the increase of annealing temperature, the tensile strength of Cu-Ni-Sn-P alloy decreased slowly first and then sharply, and finally tended to be stable. To effectively reduce energy consumption and shorten the production cycle, the reasonable recrystallization annealing system of Cu-Ni-Sn-P alloy after 60% deformation is determined to be 440°C×4h.