Patent ID: 7394249

Claim:
A printed circuit board with a weak magnetic field sensor, comprising: a substrate having a first set of first excitation circuits and first detection circuits formed on one side thereof and a second set of first excitation circuits and first detection circuits formed on the other side thereof; wherein said sets of detection circuits are longer than sets of excitation circuits; first laminates, which are layered over said substrate and over said sets of circuits on both sides of the substrate and including soft magnetic cores of a predetermined shape formed thereon; and second laminates, which are layered on the first laminates and have second excitation circuits and second detection circuits, connected through via holes to the first excitation circuits and first detection circuits, respectively, so that the first and second excitation circuits and first and second detection circuits are wound around the soft magnetic cores, formed thereon, the soft magnetic cores each including a magnetic core and non-magnetic metal layers formed on both sides of the magnetic core, and the soft magnetic cores, excitation circuits, and detection circuits formed on one side of the substrate being perpendicular to the soft magnetic cores, excitation circuits, and detection circuits formed on the other side of the substrate, respectively.