Magnetic head for perpendicular magnetic recording, head gimbal assembly, head arm assembly and magnetic disc drive

Abstract

A magnetic head comprises: a medium facing surface; a coil for generating a magnetic field corresponding to data to be written on a recording medium; and a pole layer allowing a magnetic flux corresponding to the field generated by the coil to pass therethrough, and generating a write magnetic field for writing the data on the recording medium by means of a perpendicular magnetic recording system. The pole layer incorporates a track width defining portion and a wide portion. The track width defining portion has an end face that is located in the medium facing surface and that defines the track width. The maximum width of the wide portion is greater than the track width and equal to or greater than the length of the wide portion taken in the direction orthogonal to the medium facing surface. When the coil is generating no magnetic field, in the end face of the track width defining portion, there exist first and second regions in which the directions of components of magnetization orthogonal to the medium facing surface are opposite.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view for illustrating the configuration of a magnetic head for perpendicular magnetic recording of an embodiment of the invention.

FIG. 2 is a front view of the medium facing surface of the magnetic head of FIG. 1.

FIG. 3 is a top view of the pole layer of the magnetic head of FIG. 1.

FIG. 4 is a perspective view illustrating a slider that a head gimbal assembly of the embodiment of the invention includes.

FIG. 5 is a perspective view illustrating a head arm assembly of the embodiment of the invention.

FIG. 6 is a view for illustrating a main part of a magnetic disk drive of the embodiment of the invention.

FIG. 7 is a top view of the magnetic disk drive of the embodiment of the invention.

FIG. 8 is a view for illustrating a first example of a state of magnetization in an end face of a track width defining portion.

FIG. 9 is a view for illustrating a second example of a state of magnetization in the end face of the track width defining portion.

FIG. 10 is a view for illustrating a third example of a state of magnetization in the end face of the track width defining portion.

FIG. 11 is a view for illustrating a fourth example of a state of magnetization in the end face of the track width defining portion.

FIG. 12 is a view for illustrating a fifth example of a state of magnetization in the end face of the track width defining portion.

FIG. 13 is a view for illustrating a sixth example of a state of magnetization in the end face of the track width defining portion.

Claims

1. A magnetic head for perpendicular magnetic recording comprising: a medium facing surface that faces toward a recording medium;a coil for generating a magnetic field corresponding to data to be written on the recording medium; anda pole layer allowing a magnetic flux corresponding to the field generated by the coil to pass therethrough, and generating a write magnetic field for writing the data on the recording medium by means of a perpendicular magnetic recording system, wherein:the pole layer incorporates a track width defining portion and a wide portion that is located away from the medium facing surface and coupled to the track width defining portion;the track width defining portion has an end face that is located in the medium facing surface and that defines a track width;a maximum width of the wide portion is greater than the track width and equal to or greater than a length of the wide portion taken in a direction orthogonal to the medium facing surface; andwhen the coil is generating no magnetic field, in the end face of the track width defining portion, there exist a first region and a second region in which directions of components of magnetization orthogonal to the medium facing surface are opposite.

2. The magnetic head according to claim 1, wherein, in the end face of the track width defining portion, there further exists a third region that has no component of magnetization in the direction orthogonal to the medium facing surface.

3. The magnetic head according to claim 1, wherein each of the first and second regions has an area that is equal to or smaller than two thirds of an area of the end face of the track width defining portion.

4. The magnetic head according to claim 1, wherein that track width falls within a range of 0.05 to 0.15 μm inclusive, and a length of the track width defining portion taken in the direction orthogonal to the medium facing surface falls within a range of 10 to 250 nm inclusive.

5. The magnetic head according to claim 1, wherein: a magnetostriction constant of a material forming the pole layer is greater than or equal to 10×10−6 and smaller than 50×10−6;an internal stress of the pole layer is a tensile stress that is greater than or equal to 200 MPa and smaller than or equal to 1000 MPa; andan anisotropic magnetic field in the pole layer is greater than or equal to 0 A/m and smaller than 30×79.6 A/m.

6. The magnetic head according to claim 1, wherein: a magnetostriction constant of a material forming the pole layer is greater than or equal to 10×10−6 and smaller than 50×10−6;an internal stress of the pole layer is a tensile stress that is greater than or equal to 200 Mpa and smaller than or equal to 1000 MPa; andan anisotropic magnetic field in the pole layer is greater than or equal to 30×79.6 A/m and smaller than or equal to 200×79.6 A/m.

7. The magnetic head according to claim 1, wherein: a magnetostriction constant of a material forming the pole layer is greater than or equal to zero and smaller than 15×10−6;an internal stress of the pole layer is a tensile stress that is greater than or equal to 100 MPa and smaller than or equal to 1000 MPa; andan anisotropic magnetic field in the pole layer is greater than or equal to 0 A/m and smaller than 30×79.6 A/m.

8. A head gimbal assembly comprising: a slider including a magnetic head for perpendicular magnetic recording and disposed to face toward a recording medium; and a suspension flexibly supporting the slider, wherein: the magnetic head comprises:a medium facing surface that faces toward the recording medium;a coil for generating a magnetic field corresponding to data to be written on the recording medium; anda pole layer allowing a magnetic flux corresponding to the field generated by the coil to pass therethrough, and generating a write magnetic field for writing the data on the recording medium by means of a perpendicular magnetic recording system, wherein:the pole layer incorporates a track width defining portion and a wide portion that is located away from the medium facing surface and coupled to the track width defining portion;the track width defining portion has an end face that is located in the medium facing surface and that defines a track width;a maximum width of the wide portion is greater than the track width and equal to or greater than a length of the wide portion taken in a direction orthogonal to the medium facing surface; andwhen the coil is generating no magnetic field, in the end face of the track width defining portion, there exist a first region and a second region in which directions of components of magnetization orthogonal to the medium facing surface are opposite.

9. A head arm assembly comprising: a slider including a magnetic head for perpendicular magnetic recording and disposed to face toward a recording medium; a suspension flexibly supporting the slider; and an arm for making the slider travel across tracks of the recording medium, the suspension being attached to the arm, wherein: the magnetic head comprises:a medium facing surface that faces toward the recording medium;a coil for generating a magnetic field corresponding to data to be written on the recording medium; anda pole layer allowing a magnetic flux corresponding to the field generated by the coil to pass therethrough, and generating a write magnetic field for writing the data on the recording medium through the use of a perpendicular magnetic recording system, wherein:the pole layer incorporates a track width defining portion and a wide portion that is located away from the medium facing surface and coupled to the track width defining portion;the track width defining portion has an end face that is located in the medium facing surface and that defines a track width;a maximum width of the wide portion is greater than the track width and equal to or greater than a length of the wide portion taken in a direction orthogonal to the medium facing surface; andwhen the coil is generating no magnetic field, in the end face of the track width defining portion, there exist a first region and a second region in which directions of components of magnetization orthogonal to the medium facing surface are opposite.

10. A magnetic disk drive comprising: a slider including a magnetic head for perpendicular magnetic recording and disposed to face toward a recording medium that is driven to rotate; and an alignment device supporting the slider and aligning the slider with respect to the recording medium, wherein: the magnetic head comprises:a medium facing surface that faces toward the recording medium;a coil for generating a magnetic field corresponding to data to be written on the recording medium; anda pole layer allowing a magnetic flux corresponding to the field generated by the coil to pass therethrough, and generating a write magnetic field for writing the data on the recording medium through the use of a perpendicular magnetic recording system, wherein:the pole layer incorporates a track width defining portion and a wide portion that is located away from the medium facing surface and coupled to the track width defining portion;the track width defining portion has an end face that is located in the medium facing surface and that defines a track width;a maximum width of the wide portion is greater than the track width and equal to or greater than a length of the wide portion taken in a direction orthogonal to the medium facing surface; andwhen the coil is generating no magnetic field, in the end face of the track width defining portion, there exist a first region and a second region in which directions of components of magnetization orthogonal to the medium facing surface are opposite.