Cu out-diffusion kinetics in pre-plated Cu-alloy leadframes investigated by a developed EDX-based oxidation test

The energy dispersive X-ray (EDX)-based permeation and oxidation test has been further developed by a novel theoretical analysis, in which the gradient of chemical potential rather than the concentration gradient is employed. The EDX-based permeation and oxidation tests determine Cu flux coefficients in the CuO oxide layers to be 4.17times10^-26 molldr(mldrsldrkJ/mol)^-1exp(-70.30 kJldrmol-1/RT) in temperature range of 250 degC - 400 degC. And the Cu flux coefficients in the Ni layers are 1.72times10^-32 molldr(mldrsldrkJ/mol)^-1 and 5.92times10^-32 molldr(mldrsldrkJ/mol)^-1 at temperatures of 250 degC and 300 degC, respectively.