Method of making an electrical current sensor

The present invention relates to a method of making an electrical current sensor for measuring a current by detecting the magnetic field generated by this current, the sensor comprising at least one electrical conductor portion of substantially rectangular cross-section having extremities arranged to enable connection of this conductor portion in series with two conductors carrying the current to be measured, said conductor portion being surrounded on three of its lateral faces by a magnetic circuit portion comprising ends having plane surfaces situated substantially in the plane of a fourth lateral face of said conductor portion, a magnetic field detector being arranged opposite said fourth lateral face. A method of making an electrical current sensor having an electrical conducting portion () of rectangular cross-section being surrounded, on three of its lateral faces, by a magnetic circuit portion () which has end portions (″) having planar surfaces situated substantially in a plane of a fourth lateral face of the conductor portion (), a magnetic field detector () being arranged opposite the fourth lateral face. The conductor portion () is made by photo-lithography and etching in a layer of electrically conducting material applied on a first surface of a flat support member (″) or on intermediate layers () deposited on the support member. The magnetic circuit portion () is made by photo-lithography and etching in a layer of magnetically permeable material applied on the conductor portion () on the first surface of the support member (″) or of an intermediate layer (). The magnetic field detector () is fixed to the support member (″) or on intermediate layers () deposited on a second surface of the support member.