Process for producing a write-and-read magnetic head

Claim 1

Process for producing a magnetic read-write head, comprising the operations of depositing a first magnetic material film (24) on a support, etching a groove (26) in said first magnetic film (24), said groove being shaped like a figure of eight with two loops having in common a rectilinear central portion, the magnetic film being preserved within said two loops and forms there two central pole pieces (26a, 26b) separated by a central channel (26c) corresponding to the central part of the figure of eight, filling the groove (26) with an electrically insulating material (27), etching in the insulating material (27) a notch forming a double groove (28, 30) wound respectively around the two central pole pieces (26a, 26b), depositing a conductive coating (31) at the bottom of the double groove (28, 30) and filling the double groove with an electrically insulating material (27), depositing an insulating material layer (32), etching in said layer a step having a side (33) facing the central channel (26c), but which is slightly off-centred with respect thereto, depositing an amagnetic material film (34) on the thus etched step, etching said amagnetic film (34) so as to only leave a wall (34a) perpendicular to the plane of the films and constituted by that part of the amagnetic film (34) deposited on the side (33) of the step, depositing a second magnetic material film (35) forming a boss (37) covering the wall (34a), depositing a protective coating (38) exactly following the shape of the boss and cutting the protective coating (38) of the boss (37) and the amagnetic wall (34a), so that two pole pieces (36a, 36b) separated by a gap (34a) appear.