Lead frame for semiconductor device, process for producing the same and semiconductor device using the same

Abstract

The present invention relates to a lead frame for semiconductor devices having an outer lead part improved in solder wettability which comprises i. a substrate comprising an alloy comprising at least one member selected from the group consisting of nickel, copper, iron and (nickel and copper and iron), ii. an inner lead part having a surface treated layer A, the surface treated layer A comprising silver or an alloy comprising silver, and iii. an outer lead part having a surface treated layer B, the surface treated layer B comprising silver and tin, or copper and tin, wherein the surface treated layer B has on its surface an oxidized layer comprising tin and oxygen, the atomic ratio of oxygen to tin in the oxidized layer is 0.5-1.8 and the thickness of the layer is not more than 20 nm.

Dependencies are inferred from the claim text.