Pole design for thin film magnetic heads

Claim 1

A method for manufacturing a pole design for a thin film magnetic read/write head comprising the steps of: forming a photoresist layer over a nonmagnetic substrate wherein the photoresist layer comprises a positive photoresist; exposing the photoresist layer to radiation through a mask; baking the photoresist layer wherein the baking is at a temperature selected to yield a negative profile following a subsequent development step; exposing the photoresist layer to radiation; developing the photoresist layer to form photoresist dams, whereby the photoresist dams define a trapezoidal cavity, the photoresist dams having faces which form the trapexoidal cavity by sloping toward each other in a direction away from the nonmagnetic substrate; depositing a lower thin film magnetic pole tip formed of a magnetic material upon the nonmagnetic substrate which has a generally trapezoidal shape in a cross-section taken generally perpendicular to a plane defined by a surface of the substrate with a first face in surface adjoining contact with the non-magnetic substrate and having a first face length, and a second face distal to the non-magnetic substrate and substantially parallel with the first face and having a second face length, the first face length being greater than the second face length; removing the photoresist dams from the surface of the non-magnetic substrate; depositing a non-magnetic gap layer upon the second face of the lower thin film magnetic pole tip which forms a magnetic flux gap; and depositing an upper thin film magnetic pole tip formed of a magnetic material upon the non-magnetic gap layer which has a generally trapezoidal shape in a cross-section taken generally perpendicular to the plane defined by the surface of the non-magnetic substrate with a first face in surface adjoining contact with then on-magnetic gap layer and having a first face length, a second face distal to the non-magnetic gap layer and substantially parallel with the first face and having a second face length, the first face length being less than the second face length, the upper and lower thin film magnetic pole tips forming a magnetic flux path to the magnetic flux gap which creates a fringe field region, whereby magnetic fields proximate the fringe field region and are coupled to the upper and lower thin film magnetic pole tips through the magnetic flux gap.

Claim 2

A method for manufacturing a pole design for a thin film magnetic read/write head comprising the steps of: forming a photoresist layer over a nonmagnetic substrate wherein the photoresist layer comprises a positive photoresist; exposing the photoresist layer to radiation through a mask; baking the photoresist layer wherein the baking is at a temperature selected to yield a negative profile following a subsequent development step; exposing the photoresist layer to radiation; developing the photoresist layer to form photoresist dams, whereby the photoresist dams define a trapezoidal cavity, the photoresist dams having faces which form the trapexoidal cavity by sloping toward each other in a direction away from the nonmagnetic substrate; depositing a lower thin film magnetic pole tip formed of a magnetic material upon the nonmagnetic substrate which has a generally trapezoidal shape in a cross-section taken generally perpendicular to a plane defined by a surface of the substrate with a first face in surface adjoining contact with the non-magnetic substrate and having a first face length, and a second face distal to the non-magnetic substrate and substantially parallel with the first face and having a second face length, the first face length being greater than the second face length; removing the photoresist dams from the surface of the non-magnetic substrate; depositing a non-magnetic gap layer upon the second face of the lower thin film magnetic pole tip which forms a magnetic flux gap; and depositing an upper thin film magnetic pole tip formed of a magnetic material upon the non-magnetic gap layer which has a generally trapezoidal shape in a cross-section taken generally perpendicular to the plane defined by the surface of the non-magnetic substrate with a first face in surface adjoining contact with then on-magnetic gap layer and having a first face length, a second face distal to the non-magnetic gap layer and substantially parallel with the first face and having a second face length, the first face length being less than the second face length, the upper and lower thin film magnetic pole tips forming a magnetic flux path to the magnetic flux gap which creates a fringe field region, whereby magnetic fields proximate the fringe field region and are coupled to the upper and lower thin film magnetic pole tips through the magnetic flux gap.