| 摘要 |
PROBLEM TO BE SOLVED: To obtain an alloy sufficiently applicable even to a multipin lead frame or the like by using a Cu-Zn alloy as the base and improving its stress corrosion cracking by the addition of specified amounts of Mn and/or Al and the control of the crystal grain size to a specified range. SOLUTION: This copper alloy for electronic equipment is the one having a compsn. contg., by weight 5 to 35% Zn and at least one kind of Mn and Al by 0.5 to 3% in total, contg., at need, at least one kind among Pb, Bi, Se, Te, Ca, Sr and rare earth elements by 0.001 to 0.5% in total, and the balance Cu and having 5 to 35μm crystal grain size. Mn or Al contributes to the improvement of the strength and the improvement of the stress corrosion cracking resistance, in the case of <0.5%, the effect can not sufficiently be obtd., and, in the case of >3%, its electric conductivity and castability deteriorate. Moreover, as to the crystal grain size, both in the case of <5μm and >35μm, its bending workability and stress corrosion cracking resistance are not sufficiently improved.
|
