| 摘要 |
PROBLEM TO BE SOLVED: To provide a carrier-fitted copper foil exhibiting a high adhesion force between a carrier and an ultrathin copper foil before a step of being laminated on an insulating substrate but easily peelable via the carrier-ultrathin copper foil interface after the laminating step and having a favorable ultrathin copper foil etchability.SOLUTION: A roughened layer of Rz=1.6 μm or less is formed on the ultrathin copper layer surface of the carrier-fitted copper foil. The intermediate layer thereof comprise Ni. In a case where, on an occasion for hot-pressing an insulating substrate onto the ultrathin copper layer under specified conditions and then peeling the ultrathin copper layer therefrom, the chromium atom concentration (%), its zinc counterpart (%), its nickel counterpart (%), its copper counterpart (%), its oxygen counterpart (%), its carbon counterpart (%), and its counterpart of others (%) along the depth direction ascertained as a result of X-ray photoelectron spectroscopic (XPS) surface analysis (x: unit nm) are defined respectively as e(x), f(x), g(x), h(x), i(x), j(x), and k(x), ∫g(x)dx/(∫e(x)dx+∫f(x)dx+∫g(x)dx+∫h(x)dx+∫i(x)dx+∫j(x)dx+∫k(x)dx) satisfies the condition of 20.0% or less within the zone [0, 1.0] of analysis along the direction of depth from the intermediate layer-side surface of the ultrathin copper layer. |
