Patent ID: 8723631

Claim:
An apparatus comprising a printed circuit board, said printed circuit board comprising a stack of metallization layers, and a coil, said metallization layers being stacked along a vertical direction and separated mechanically from one another by electrically insulating layers, and said coil extending along a vertical winding axis and comprising turns formed by conductive tracks made in respective metallization layers, said turns being electrically connected to one another by pads going through at least one of said electrically insulating layers, wherein said metallization layers define a plane on which lie an X axis and a Y axis orthogonal to said X axis, wherein said coil comprises first conductive tracks that are made in a first metallization layer, and second conductive tracks that are made in a second metallization layer that is immediately consecutive to said first metallization layer in said vertical direction, wherein said first conductive tracks are devoid of symmetry relative to at least one of said X axis and said Y axis, wherein said second conductive tracks are devoid of symmetry relative to at least one of said X axis and said Y axis, wherein a superimposition of said first and second conductive tracks on said plane forms a pattern having axial symmetry relative to said X axis, and axial symmetry relative to said Y axis.