Patent ID: 6024809
Filing Date: 2000-02-15
Classification: C22C

Abstract:
A method of enhancing the etch factor of a Fe--Ni alloy material for electronic parts, the steps comprising;providing Fe--Ni alloy material consisting of, all by weight, from 30 to 55% Ni, 0.8% or less Mn, 0.02% or less Al, less than 0.003 or more than 0.0100% N, and the balance Fe and unavoidable impurities;melting said Fe--Ni alloy material to provide a molten Fe--Ni alloy material;controlling N content in the final Fe--Ni alloy material in the range from 0.003 to 0.0100%, by at least one step selected from the group consisting of a) adding iron or nickel nitride into the molten Fe--Ni alloy material to adjust the N content and b) holding the Fe--Ni molten alloy material in a furnace into which nitrogen gas is introduced and kept at an internal pressure of 1 to 300 torrs for 1 to 30 minutes, then cast at an internal pressure of 0.5 torr to adjust the N content;wherein the etch factor being defined as the ratio of the etching rate in the thickness direction to the etching rate in the side direction when the Fe--Ni alloy material is etched.