FLEXIBLE COPPER-CLAD LAMINATE SHEET

摘要

PROBLEM TO BE SOLVED: To provide a flexible copper-clad laminate sheet yielding a flexible circuit substrate having an excellent folding flexural resistance and capable, even when used within thin or narrow housings of electronic appliances, of preventing wire ruptures or cracks of wiring circuits.SOLUTION: The provided flexible copper-clad laminate sheet used for a flexible circuit substrate comprises: a polyimide layer (A) whose thickness and tensile modulus of elasticity are confined respectively to ranges of 5-30μm and 4-10 GPa; and a copper foil (B) laminated on at least one surface of the polyimide layer (A) and whose thickness and tensile modulus of elasticity are confined respectively to ranges of 6-20μm and 25-35 GPa. The ten-point average roughness (Rz) of the surface of the copper foil (B) on the side thereof contacted with the polyimide layer (A) within this flexible copper-clad laminate sheet is confined to a range of 0.7-2.2μm. The creasing habit coefficient [PF] of a case where an arbitrary flexible circuit substrate on which copper wires have been formed as a result of a wiring circuit work of the copper foil (B) is subjected to a folding flexural test at a gap of 0.3 mm is confined to a range of 0.96±0.025.