エッチング加工性に優れたCu–Ni–Co–Si系高強度銅合金の開発

抄録

In order to produce thin and small semiconductor packages, leadframes with fine pitch and multi–pin are demanded. So, leadframe materials should possess higher strength, higher electrical conductivity, and excellent etching characteristics. In this study, we successfully developed novel Cu–Ni–Co–Si alloys for high–performed leadframes by optimizing thermomechanical process conditions. The Cu–Ni–Co–Si alloys have tensile strength of 1020 MPa, electrical conductivity of 38%IACS and high heat resistance, which overcome conventional leadframe materials of Cu–Ni–Si alloys. In addition, the Cu–Ni–Co–Si alloys exhibit an excellent etching characteristics comparable to conventional Cu–Ni–Si alloys. The excellent etching characteristics for the alloys can be explained by fine grain size rather than dislocation, precipitates, and grain orientation. Thus, the Cu–Ni–Co–Si alloys are promissing to be applied widely for thin and multi–pin leadframes in ultra–miniaturized communication and information devices.