IC package and LSI package using a lead frame formed of a copper- zirconium alloy

摘要

An IC package and LSI package having a lead frame of a copper alloy that contains 0.1 to 1% by weight of chromium, 0.01 to 0.5% by weight of zirconium and that has partial discolored regions caused by unbalanced precipitation of the zirconium distributed thereon at a rate of 2 grains/100 cm.sup.2 or less is disclosed. The lead frame is, for example, obtained from an alloy that contains 0,005% by weight of sulfur or less. The lead frame has high reliability, can be produced in high yield and has high electrical conductivity.