FLEXIBLE PRINTED CIRCUIT BOARD

摘要

PURPOSE: A flexible printed circuit board is provided to easily process into a flexible printed circuit board exhibiting excellent stability of the electric circuit even with extreme fineness of the circuit pattern. CONSTITUTION: A base sheet is provided with a layer of an electrically insulating material having flexible, such as a plastic resin film and a copper foil. The copper foil has a thickness in the range from 5 to 18 micrometers. The surface in contact an adhesive layer has a surface roughness expressed by the Rz value not exceeding 3 micrometer and is provided with a surface treatment layer containing nickel in an amount not exceeding 0.2 g/mor, preferably, in the range from 0.001 to 0.1 g/m.