DOUBLE LAYERED TAB TAPE AND ITS MANUFACTURE

摘要

One side of a strip of copper foil out of two strips thereof, or one side of each of two strips of copper foil is coated with polyimide varnish. These are heated and thereafter bonded with the non-varnished sides of strips outside. Then the varnish between the strips is thermally cured under pressure. The surface roughness (Rz) of the copper foil on the polyimide film side is less than 0.6 mu m, and the tensile strength of the copper foil is higher than 20 kg/mm<2> after the varnish is cured.