Patent ID: 6943302

Claim:
A flexible printed circuit board that directly relays connecting portions of a magnetic head placed on a suspension to connecting portions of a base end of a carriage arm in a head suspension assembly of a magnetic disk apparatus, wherein the flexible printed circuit board includes at least: a stainless layer; a base layer formed on the stainless layer; a plurality of conductive circuits formed on the base layer; a cover layer covering the conductive circuits; and a first conductive polymer layer portion formed at least on an upper side of the cover layer, wherein the base layer and the cover layer are made of polyimide resin or epoxy resin, and the conductive polymer layer is made of polypyrrole resin, the cover layer is not formed in the magnetic head connecting portion, and on the base layer in the magnetic head connecting portion, a second conductive polymer layer portion is formed and presents, and on the plurality of conductive circuits in the magnetic head connecting portion, the first and second conductive polymer layer portions are not present or are substantially absent, if any, to such a degree as to allow the magnetic head to be electrically connected to the conductive circuits.