Relation between contact reliability and electrical conductivity of copper alloys for large current terminal

摘要

For copper alloys applied to large current terminals, high electrical conductivity is necessary in order to keep its contact reliability. Furthermore, stress relaxation property is important in order to keep low contact resistance. Stress relaxation, creep and leak resistance properties were compared for two different copper alloys having nearly same high conductivity. One was strengthened by Fe{sub}2P particles and another by α and γ-Fe particles. Though the species of strengthening dispersoids were quite effective on the creep, the species of dispersoids had no influence on the stress relaxation property. For holding low resistance of insulation displacement contact between copper alloy surfaces without tin plating, the creep may be more important than the stress relaxation, because a small amount of creep strain must be enough to permit oxidization in the gastight contacts. Finally, the leak resistance property was compared for these high conductivity copper alloys. Mainly the chemical composition of these alloys seemed to be effective on the leak current.