Cu-Ni-Si-Co-Cr System Alloy for Electronic Materials

Abstract

The problem to be solved by the present invention is to provide a significant improvement in the properties in Cu—Ni—Co—Si alloy by adding Cr, i.e., to provide Corson alloys having high strength and high electrical conductivity. There is provided a copper alloy for electronic materials comprising 1.0 to 4.5 mass % of Ni, 0.50 to 1.2 mass % of Si, 0.1 to 2.5 mass % of Co, 0.003 to 0.3 mass % of Cr, with the balance being Cu and unavoidable impurities, the mass concentration ratio of the total mass of Ni and Co to Si ([Ni+Co]/Si ratio) satisfies the formula: 4≦[Ni+Co]/Si≦5, and with regard to Cr—Si compound whose size is 0.1 to 5 μm dispersed in the material, atomic concentration ratio of Cr to Si in the dispersed particle is 1-5, and area dispersion density thereof is more than 1×10 4 /mm 2 , and not more than 1×10 6 /mm 2 .

1 . A copper alloy for electronic materials comprising 1.0 to 4.5 mass % of Ni, 0.50 to 1.2 mass % of Si, 0.1 to 2.5 mass % of Co, 0.003 to 0.3 mass % of Cr, with the balance being Cu and unavoidable impurities, the mass concentration ratio of the total mass of Ni and Co to Si ([Ni+Co]/Si ratio) satisfies the formula: 4≦[Ni+Co]/Si≦5, and with regard to Cr—Si compound particles whose size is 0.1 to 5 μm dispersed in the material, the atomic concentration ratio of Cr to Si in the dispersed particle is 1-5, and area dispersion density thereof is more than 1×10 4 /mm 2 , and not more than 1×10 6 /mm 2 . 
     
     
         2 . The copper alloy for electronic materials according to  claim 1  wherein area dispersion density of the Cr—Si compound particles whose size is more than 5 μm dispersed in the material is not more than 50/mm 2 . 
     
     
         3 . The copper alloy for electronic materials according to  claim 1  wherein the alloy further comprises one or more of Sn and Zn at 0.05-2.0 mass %. 
     
     
         4 . The copper alloy for electronic materials according to  claim 1  wherein the alloy further comprises one or more of Mg, Mn, Ag, P, As, Sb, Be, B, Ti, Zr, Al and Fe at 0.001-2.0 mass %. 
     
     
         5 . A wrought copper alloy product made of the copper alloy according to any one of  claims 1 - 4 . 
     
     
         6 . Electronic components comprising the copper alloy according to any one of  claims 1 - 4 . 
     
     
         7 . Electronic components comprising a wrought copper alloy product according to  claim 5 .