Process for the production of planar structure thin film magnetic heads

A process for producing planar structure thin film magnetic heads, which comprises:

• forming a first insulating film on an insulating substrate,
• etching the insulating film and the substrate to form a first recess,
• depositing thereon a first conductive film, which is then selectively etched in such a way that it only remains at the bottom of the first recess,
• depositing a first magnetic film by a first electrolysis taking the conductive film as the electrode so that said first magnetic film fills the recess and is level with the surface of the first insulating film,
• depositing a second insulating film thereon wherein an electric coil is formed in said second insulating film,
• etching in the second insulating film, on either side of the coil, two openings reaching the first magnetic film,
• filling said openings by a second electrolysis using the first conductive film as the electrode, to thereby produce magnetic contact pads, which have a good magnetic continuity with the first magnetic film and are level with the surface of the second insulating film,
• depositing thereon a third insulating film,
• etching in said third insulating film, above the magnetic contact pads, second and third recesses, leaving between said second and third recesses a central insulating island,
• depositing thereon a second conductive film, which is then selectively etched so as to leave it at the bottom of the second and third recesses,
• filling the second and third recesses with a second magnetic film subdivided into two parts and located on either side of the central insulating island, said second magnetic film being level with the surface of the third insulating film, by a third electrolysis using the second conductive film as the electrode,
• depositing thereon a fourth hard protective insulating film, into which is etched a fourth recess above the central insulating island and reaching the second magnetic film,
• forming in said fourth recess a thin amagnetic spacer centered on the central insulating island,
• depositing thereon a third conductive film, which is then selectively etched so as to only leave it at the bottom of the fourth recess on either side of the spacer,
• filling the fourth recess with a third magnetic film subdivided into two parts located on either side of the amagnetic spacer, said third magnetic film being level with the surface of the hard protective film, by a fourth electrolysis using the third conductive film as the electrode.