Magnetic head including spin torque oscillator

1. A magnetic head comprising:

a medium facing surface configured to face a recording medium;

a main pole configured to generate a write magnetic field for writing data on the recording medium;

a trailing shield formed of a magnetic material and located forward in a direction of travel of the recording medium relative to the main pole;

a spin torque oscillator disposed between the main pole and the trailing shield and electrically connected to the main pole and the trailing shield; and

a first insulating layer interposed between a portion of the main pole and a portion of the spin torque oscillator, wherein

the first insulating layer has a first end closest to the medium facing surface,

the spin torque oscillator has a rear end farthest from the medium facing surface, and

the first end of the first insulating layer is located closer to the medium facing surface than the rear end of the spin torque oscillator is.

2. The magnetic head according to claim 1 , wherein

the main pole has a top surface facing toward the trailing shield,

the trailing shield has a bottom surface facing toward the main pole,

the bottom surface of the trailing shield includes a first portion having an end located in the medium facing surface and being in contact with the spin torque oscillator at least in part, and a second portion connected to the first portion at a position away from the medium facing surface,

the first portion extends along the top surface of the main pole,

a distance between the second portion and the main pole is a minimum at a border between the first portion and the second portion, and a maximum at a position away from the border, and

an element height that is a dimension of the spin torque oscillator in a direction perpendicular to the medium facing surface and a writer height that is a dimension of the first portion in the direction perpendicular to the medium facing surface are different from each other.

3. The magnetic head according to claim 2 , wherein the element height is greater than the writer height.

4. The magnetic head according to claim 3 , wherein

the element height is in a range of 40 to 100 nm, and

the writer height is in a range of 10 to 35 nm.

5. The magnetic head according to claim 3 , further comprising a second insulating layer interposed between a portion of the trailing shield and a portion of the spin torque oscillator, wherein

the second insulating layer has a second end closest to the medium facing surface, and

the second end of the second insulating layer is located closer to the medium facing surface than the rear end of the spin torque oscillator is.

6. The magnetic head according to claim 5 , wherein the first end of the first insulating layer is located closer to the medium facing surface than the second end of the second insulating layer is.

7. The magnetic head according to claim 5 , wherein the second end of the second insulating layer is located closer to the medium facing surface than the first end of the first insulating layer is.

8. The magnetic head according to claim 1 , further comprising a heat sink, wherein

the heat sink is disposed between the main pole and the trailing shield at a position farther from the medium facing surface than the spin torque oscillator is, and in contact with the spin torque oscillator.

9. The magnetic head according to claim 1 , further comprising a first heat sink, wherein

a portion of the first heat sink is interposed between the spin torque oscillator and the first insulating layer.

10. The magnetic head according to claim 9 , further comprising a second heat sink, wherein

the second heat sink is disposed on the first heat sink at a position farther from the medium facing surface than the spin torque oscillator is, and in contact with the spin torque oscillator and the first heat sink.

11. The magnetic head according to claim 1 , wherein

the top surface of the main pole includes a rear portion in contact with the first insulating layer, and a front portion located between the medium facing surface and the rear portion and not in contact with the first insulating layer, and

the front portion is recessed from an imaginary plane including the rear portion in a direction away from the trailing shield.

12. The magnetic head according to claim 1 , wherein

the top surface of the main pole includes a rear portion in contact with the first insulating layer, and a front portion located between the medium facing surface and the rear portion and not in contact with the first insulating layer,

the first insulating layer has an inclined surface contiguous with the front portion, and

an angle that the front portion forms with respect to the direction perpendicular to the medium facing surface is greater than an angle that the rear portion forms with respect to the direction perpendicular to the medium facing surface.

13. The magnetic head according to claim 1 , further comprising a substrate having a top surface, wherein

the main pole, the trailing shield, the spin torque oscillator, and the first insulating layer are located above the top surface of the substrate,

the spin torque oscillator has a first side surface and a second side surface opposite to each other in a track width direction,

the first side surface and the second side surface respectively form a first angle and a second angle with respect to a direction perpendicular to the top surface of the substrate, and

the first angle and the second angle are each in a range of 0° to 10°.