Method of making an inductive circuit incorporated in a planar circuit support member

摘要

A planar support member for an electric circuit, e.g. a printed circuit board, wherein at least a region of the support member includes magnetic material through at least a part of its thickness. A magnetic circuit is made in this material by forming at least one opening through it. The support member is then coated with insulative material and conductor paths are made on both faces of the support member by conventional techniques for such members. These paths include a winding disposed around a core part of the magnetic circuit with alternate half turns being formed on opposite faces and interconnected by through plating. The inductive circuit thus formed may constitute an inductor, a transformer or a relay.