Flexible circuit substrate

摘要

A flexible circuit substrate includes a laminate which contains a polymer film, a VIB group metal layer deposited on the polymer film, a nickel-chromium alloy layer deposited on the VIB group metal layer, a first copper layer deposited on the nickel-chromium alloy layer, and a second copper layer plated on the first copper layer. The VIB group metal layer has a reduced expansion coefficient gradient relative to the polymer film as compared to an expansion coefficient gradient between the polymer film and the nickel-chromium alloy layer. The nickel-chromium alloy layer has a reduced expansion coefficient gradient relative to the first copper layer as compared to an expansion coefficient gradient between the first copper layer and the VIB group metal layer.