Thin-film magnetic head for perpendicular magnetic recording and manufacturing method of thin-film magnetic head

A thin-film magnetic head comprising at least one inductive write head element comprising:

• a main magnetic pole layer having an inner saturation magnetic flux density varying from both side end surfaces in a track-width direction and a leading end surface of said main magnetic pole layer, toward a center portion in said track-width direction of a trailing end surface of said main magnetic pole layer, for generating a write field;
• an auxiliary magnetic pole layer having one end portion being adjacent to one end portion of said main magnetic pole layer and the other end portion connected magnetically with the other end portion of said main magnetic pole layer;
• and
• at least one coil layer formed in such a way as to pass through between said main magnetic pole layer and said auxiliary magnetic pole layer for inducing a magnetic flux in said main magnetic pole layer and said auxiliary magnetic pole layer,
• a slope a of a regression line obtained by least square method of a distribution of said inner saturation magnetic flux density under a condition that a positive direction of position coordinate is defined as a direction from said both side end surfaces and said leading end surface toward said center portion of said trailing end surface, satisfying the following expression:
• −(0.000157*WT+0.0126)=a<0
• where a unit of a is Tesla/nm, WT is a track width, and a unit of WC and WT is nanometer.

A head gimbal assembly comprising:

• a thin-film magnetic head comprising at least one inductive write head element comprising:
• a main magnetic pole layer having an inner saturation magnetic flux density varying from both side end surfaces in a track-width direction and a leading end surface of said main magnetic pole layer, toward a center portion in said track-width direction of a trailing end surface of said main magnetic pole layer, for generating a write field;
• an auxiliary magnetic pole layer having one end portion being adjacent to one end portion of said main magnetic pole layer and the other end portion connected magnetically with the other end portion of said main magnetic pole layer;
• and
• at least one coil layer formed in such a way as to pass through between said main magnetic pole layer and said auxiliary magnetic pole layer for inducing a magnetic flux in said main magnetic pole layer and said auxiliary magnetic pole layer,
• a curvature width WC of a contour line of said write field adjacent to a trailing edge on an air bearing surface side of said main magnetic pole layer satisfying the following expression:
• −0.15*WT=WC<12
• where WT is a track width and a unit of WC and WT is nanometer;
• and
• a support structure for supporting said thin-film magnetic head.

A head gimbal assembly comprising:

• a thin-film magnetic head comprising at least one inductive write head element comprising:
• a main magnetic pole layer having an inner saturation magnetic flux density varying from both side end surfaces in a track-width direction and a leading end surface of said main magnetic pole layer, toward a center portion in said track-width direction of a trailing end surface of said main magnetic pole layer, for generating a write field;
• an auxiliary magnetic pole layer having one end portion being adjacent to one end portion of said main magnetic pole layer and the other end portion connected magnetically with the other end portion of said main magnetic pole layer;
• and
• at least one coil layer formed in such a way as to pass through between said main magnetic pole layer and said auxiliary magnetic pole layer for inducing a magnetic flux in said main magnetic pole layer and said auxiliary magnetic pole layer,
• a slope a of a regression line obtained by least square method of a distribution of said inner saturation magnetic flux density under a condition that a positive direction of position coordinate is defined as a direction from said both side end surfaces and said leading end surface toward said center portion of said trailing end surface, satisfying the following expression:
• −(0.000157*WT+0.0126)=a<0
• where a unit of a is Tesla/nm, WT is a track width, and a unit of WC and WT is nanometer;
• and
• a support structure for supporting said thin-film magnetic head.

A magnetic disk drive apparatus comprising:

• at least one head gimbal assembly comprising:
• a thin-film magnetic head comprising at least one inductive write head element comprising:
• a main magnetic pole layer having an inner saturation magnetic flux density varying from both side end surfaces in a track-width direction and a leading end surface of said main magnetic pole layer, toward a center portion in said track-width direction of a trailing end surface of said main magnetic pole layer, for generating a write field;
• an auxiliary magnetic pole layer having one end portion being adjacent to one end portion of said main magnetic pole layer and the other end portion connected magnetically with the other end portion of said main magnetic pole layer;
• and
• at least one coil layer formed in such a way as to pass through between said main magnetic pole layer and said auxiliary magnetic pole layer for inducing a magnetic flux in said main magnetic pole layer and said auxiliary magnetic pole layer,
• a curvature width WC of a contour line of said write field adjacent to a trailing edge on an air bearing surface side of said main magnetic pole layer satisfying the following expression:
• −0.15*WT=WC<12
• where WT is a track width and a unit of WC and WT is nanometer;
• and
• a support structure for supporting said thin-film magnetic head;
• and
• at least one magnetic disk;
• and
• a recording/reproducing control means for controlling read and write operations of said thin-film magnetic head to said at least one magnetic disk.

A magnetic disk drive apparatus comprising:

• at least one head gimbal assembly comprising:
• a thin-film magnetic head comprising at least one inductive write head element comprising:
• a main magnetic pole layer having an inner saturation magnetic flux density varying from both side end surfaces in a track-width direction and a leading end surface of said main magnetic pole layer, toward a center portion in said track-width direction of a trailing end surface of said main magnetic pole layer, for generating a write field;
• an auxiliary magnetic pole layer having one end portion being adjacent to one end portion of said main magnetic pole layer and the other end portion connected magnetically with the other end portion of said main magnetic pole layer;
• and
• at least one coil layer formed in such a way as to pass through between said main magnetic pole layer and said auxiliary magnetic pole layer for inducing a magnetic flux in said main magnetic pole layer and said auxiliary magnetic pole layer,
• a slope a of a regression line obtained by least square method of a distribution of said inner saturation magnetic flux density under a condition that a positive direction of position coordinate is defined as a direction from said both side end surfaces and said leading end surface toward said center portion of said trailing end surface, satisfying the following expression:
• −(0.000157*WT+0.0126)=a<0
• where a unit of a is Tesla/nm, WT is a track width, and a unit of WC and WT is nanometer;
• and
• a support structure for supporting said thin-film magnetic head;
• and
• at least one magnetic disk;
• and
• a recording/reproducing control means for controlling read and write operations of said thin-film magnetic head to said at least one magnetic disk.

A manufacturing method of a thin-film magnetic head comprising steps of:

• forming a patterned resist layer on a non-magnetic layer formed on/above an element-formed surface of a substrate;
• forming at least one soft-magnetic film to be at least one main pole soft-magnetic layer and a soft-magnetic center film to be a main pole center layer sequentially on said non-magnetic layer and said patterned resist layer;
• forming a trailing end surface on which edges of said at least one main pole soft-magnetic layer and said main pole center layer are exposed with said main pole center layer as a central part, by using chemical mechanical polishing method and/or ion milling technique;
• and
• removing said patterned resist layer to form a main magnetic pole layer.

A manufacturing method of a thin-film magnetic head comprising steps of:

• forming a patterned resist layer on a non-magnetic layer formed on/above an element-formed surface of a substrate;
• forming a soft-magnetic film to be a main magnetic pole layer with an inner saturation magnetic flux density continuously varied by changing deposition conditions continuously during deposition on said non-magnetic layer and said patterned resist layer;
• forming a trailing end surface on which an edge of said main magnetic pole layer is exposed by using chemical mechanical polishing method and/or ion milling technique;
• and
• removing said patterned resist layer to form said main magnetic pole layer.