Thin-film magnetic head with near-field-light-generating layer

Abstract

A thin-film magnetic head that has a configuration in which the element-formed surface and the opposed-to-medium surface are perpendicular to each other, and a light source is sufficiently distanced from the medium surface is provided. The head comprises at least one near-field-light-generating layer for heating a part of a magnetic medium during write operation by generating a near-field light, having a shape tapered toward a head end surface on the opposed-to-medium surface side, and comprising a near-field-light-generating portion having a light-received surface and a tip reaching the head end surface on the opposed-to-medium surface side, and the light-received surface being sloped in respect to the element-formed surface and being provided in a position where an incident light propagating from a head end surface opposite to the opposed-to-medium surface can reach at least a part of the light-received surface.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 shows a perspective view schematically illustrating a major portion of an embodiment of the magnetic disk drive apparatus according to the present invention;

FIGS. 2 a and 2b show perspective views illustrating an embodiment of the HGA according to the present invention;

FIG. 3 a shows a perspective view of the first and second embodiments of the thin-film magnetic head provided on the end portion of the HGA;

FIG. 3 b shows a plain view schematically illustrating a magnetic head element shown in FIG. 3a;

FIG. 4 a shows a cross-sectional view taken along the line A-A in FIG. 3a schematically illustrating a major portion of the first embodiment of the thin-film magnetic head according to the present invention;

FIG. 4 b shows a perspective view schematically illustrating the NFL-generating layer and the main magnetic pole layer that are overlapped with each other;

FIG. 5 a shows a schematic view for defining a slope angle θ;

FIG. 5 b shows a conceptual graph explaining the effect of the slope angle θ;

FIGS. 6 a to 6d show cross-sectional views and perspective views schematically illustrating various alternatives of the NFL-generating layer in the first embodiment of the thin-film magnetic head according to the present invention;

FIGS. 7 a to 7c2 show cross-sectional views and perspective views schematically illustrating various alternatives of the NFL-generating layer in the first embodiment of the thin-film magnetic head according to the present invention;

FIG. 8 a shows a cross-sectional view taken along the line A-A in FIG. 3a schematically illustrating a major portion of the second embodiment of the thin-film magnetic head according to the present invention;

FIG. 8 b shows a perspective view schematically illustrating the NFL-generating layer, the thermal protrusion layer and the main magnetic pole layer;

FIGS. 9 a to 9c show cross-sectional views schematically illustrating various alternatives of the NFL-generating layer and the thermal protrusion layer in the second embodiment of the thin-film magnetic head according to the present invention;

FIG. 10 a shows a perspective view of a third embodiment of the thin-film magnetic head provided on the end portion of the HGA shown in FIGS. 2a and 2b;

FIG. 10 b shows a plain view schematically illustrating a magnetic head element shown in FIG. 10a;

FIG. 11 shows a cross-sectional view taken along the line B-B in FIG. 10a schematically illustrating a major portion of the third embodiment of the thin-film magnetic head according to the present invention;

FIGS. 12 a to 12c show cross-sectional views and perspective views schematically illustrating various alternatives of the NFL-generating layer, the reflective layer and the cavity in the third embodiment of the thin-film magnetic head according to the present invention;

FIGS. 13 a to 13c show cross-sectional views explaining an embodiment of the manufacturing process of the end portion of the main magnetic pole layer and the NFL-generating portion in the first embodiment of the thin-film magnetic head according to the present invention;

FIGS. 14 a to 14c show cross-sectional views explaining an embodiment of the manufacturing process of the thermal protrusion layer and the NFL-generating portion in the second embodiment of the thin-film magnetic head according to the present invention;

FIGS. 15 a to 15d show cross-sectional views explaining an embodiment of the manufacturing process of the cavity in the third embodiment of the thin-film magnetic head according to the present invention; and

FIG. 16 shows a block diagram illustrating the circuit structure of the recording/reproducing and light-emission control circuit of the magnetic disk drive apparatus shown in FIG. 1.

Claims

1. A thin-film magnetic head comprising: a substrate having an opposed-to-medium surface and an element-formed surface perpendicular to said opposed-to-medium surface;an electromagnetic coil element for writing data signals, formed on/above said element-formed surface, and having a main magnetic pole layer, an auxiliary magnetic pole layer and a write coil layer; andat least one near-field-light-generating layer for heating a part of a magnetic medium during write operation by generating a near-field light,said at least one near-field-light-generating layer having a shape tapered toward a head end surface on the opposed-to-medium surface side, and comprising a near-field-light-generating portion having a light-received surface and a tip reaching the head end surface on the opposed-to-medium surface side, andsaid light-received surface being sloped in respect to said element-formed surface in the form that a portion in the head end surface side of said light-received surface is lifted up, and being provided in a position where an incident light propagating from a head end surface opposite to said opposed-to-medium surface can reach at least a part of said light-received surface.

2. The thin-film magnetic head as claimed in claim 1, wherein at least one of said at least one near-field-light-generating layer further comprises a first reflective portion that has a first reflecting surface parallel to said element-formed surface, and is positioned on the opposite side to said opposed-to-medium surface in relation to said near-field-light-generating portion.

3. The thin-film magnetic head as claimed in claim 2, wherein at least one of said at least one near-field-light-generating layer further comprises a second reflective portion that has at least one second reflecting surface with a slope angle in respect to said element-formed surface smaller than that of said light-received surface, and is positioned between said near-field-light-generating portion and said first reflective portion.

4. The thin-film magnetic head as claimed in claim 1, wherein said main magnetic pole layer is provided in a position on the opposite side to said light-received surface in relation to one of said at least one near-field-light-generating layer, and said near-field-light-generating portion and an end portion in the opposed-to-medium surface side of said main magnetic pole layer are overlapped through a dielectric layer or directly.

5. The thin-film magnetic head as claimed in claim 4, wherein said near-field-light-generating portion and said end portion of said main magnetic pole layer are sloped in respect to said element-formed surface in the form that portions in the opposed-to-medium surface side of said near-field-light-generating portion and said end portion are lifted up or pulled down.

6. The thin-film magnetic head as claimed in claim 1, wherein said main magnetic pole layer is provided in a position on the light-received surface side in relation to one of said at least one near-field-light-generating layer, and said main magnetic pole layer and the near-field-light-generating layer are in contact with or close to each other only at an end in the opposed-to-medium surface side of said main magnetic pole layer and at a tip of the near-field-light-generating layer reaching the head end surface on the opposed-to-medium surface side.

7. The thin-film magnetic head as claimed in claim 1, wherein said at least one near-field-light-generating layer is two near-field-light-generating layers, and two light-received surfaces of said two near-field-light-generating layers are sloped in respect to said element-formed surface in the form that portions in the opposed-to-medium surface side of said two light-received surfaces are lifted up and pulled down respectively, and two tips of said two near-field-light-generating layers reaching the head end surface on the opposed-to-medium surface side are in contact with or close to each other.

8. The thin-film magnetic head as claimed in claim 1, wherein an overcoat layer is further provided on said element-formed surface so as to cover said electromagnetic coil element and said at least one near-field-light-generating layer, and a region of said overcoat layer including all the light paths of an incident light propagating from the head end surface opposite to said opposed-to-medium surface to said light-received surface is formed of silicon dioxide or an oxide that consists primarily of silicon dioxide.

9. The thin-film magnetic head as claimed in claim 1, wherein an overcoat layer is further provided on said element-formed surface so as to cover said electromagnetic coil element and said at least one near-field-light-generating layer, and a thermal protrusion layer made of a material having a larger coefficient of thermal expansion than that of said overcoat layer is provided close to said near-field-light-generating portion.

10. The thin-film magnetic head as claimed in claim 9, wherein said main magnetic pole layer is provided in a position on the opposite side to said light-received surface in relation to one of said at least one near-field-light-generating layer, and said thermal protrusion layer is positioned between said near-field-light-generating portion and an end portion in the opposed-to-medium surface side of said main magnetic pole layer, and is in contact with or close to said end portion.

11. The thin-film magnetic head as claimed in claim 9, wherein said main magnetic pole layer is provided in a position on the light-received surface side in relation to one of said at least one near-field-light-generating layer, and said main magnetic pole layer and the near-field-light-generating layer are in contact with or close to each other only at an end in said opposed-to-medium surface side of said main magnetic pole layer and at a tip of the near-field-light-generating layer reaching the head end surface on the opposed-to-medium surface side, and said thermal protrusion layer is positioned on the opposite side to said main magnetic pole layer in relation to said near-field-light-generating portion.

12. The thin-film magnetic head as claimed in claim 9, wherein said material of which said thermal protrusion layer is made is a non-magnetic metal.

13. The thin-film magnetic head as claimed in claim 1, wherein an overcoat layer is further provided on said element-formed surface so as to cover said electromagnetic coil element and said at least one near-field-light-generating layer, a cavity is formed in a region in the opposite side to the opposed-to-medium surface of said overcoat layer and reaching the head end surface opposite to said opposed-to-medium surface, to which an end portion of an optic fiber for launching a light toward at least one near-field-light generating-layer can be inserted, andsaid cavity has a light-received wall surface for receiving and allowing passage of the light from said optic fiber, said light-received wall surface recessed from the head end surface opposite to said opposed-to-medium surface toward at least one near-field-light-generating layer.

14. The thin-film magnetic head as claimed in claim 13, wherein a magnetoresistive effect element for reading data signals is further provided between said element-formed surface and said electromagnetic coil element, and a bottom surface parallel to said element-formed surface of said cavity is positioned above a region on the rear side of said magnetoresistive effect element when viewing from the opposed-to-medium surface side.

15. The thin-film magnetic head as claimed in claim 13, wherein a reflective layer is further provided on the light-received surface side of said at least one near-field-light generating-layer, having a third reflecting surface for reflecting a part of incident light that propagates across said light-received wall surface and directing the light toward said light-received surface.

16. The thin-film magnetic head as claimed in claim 15, wherein said third reflecting surface is sloped in respect to said element-formed surface so as to reflect a part of incident light that propagates obliquely across said light-received wall surface and direct the light toward said light-received surface.

17. The thin-film magnetic head as claimed in claim 13, wherein an antireflective film having a monolayer structure or a multilayered structure is formed on said light-received wall surface.

18. A head gimbal assembly comprising: a thin-film magnetic head comprising:a substrate having an opposed-to-medium surface and an element-formed surface perpendicular to said opposed-to-medium surface;an electromagnetic coil element for writing data signals, formed on/above said element-formed surface, and having a main magnetic pole layer, an auxiliary magnetic pole layer and a write coil layer; andat least one near-field-light-generating layer for heating a part of a magnetic medium during write operation by generating a near-field light,said at least one near-field-light-generating layer having a shape tapered toward a head end surface on the opposed-to-medium surface side, and comprising a near-field-light-generating portion having a light-received surface and a tip reaching the head end surface on the opposed-to-medium surface side, andsaid light-received surface being sloped in respect to said element-formed surface in the form that a portion in the head end surface side of said light-received surface is lifted up, and being provided in a position where an incident light propagating from a head end surface opposite to said opposed-to-medium surface can reach at least a part of said light-received surface;a support mechanism for supporting said thin-film magnetic head;trace conductors for said electromagnetic coil element;trace conductors for a magnetoresistive effect element when said thin-film magnetic head comprises said magnetoresistive effect element; andan optic fiber for launching a light that propagates across the head end surface opposite to said opposed-to-medium surface.

19. The head gimbal assembly as claimed in claim 18, wherein at least one of said at least one near-field-light-generating layer further comprises a first reflective portion that has a first reflecting surface parallel to said element-formed surface, and is positioned on the opposite side to said opposed-to-medium surface in relation to said near-field-light-generating portion.

20. The head gimbal assembly as claimed in claim 19, wherein at least one of said at least one near-field-light-generating layer further comprises a second reflective portion that has at least one second reflecting surface with a slope angle in respect to said element-formed surface smaller than that of said light-received surface, and is positioned between said near-field-light-generating portion and said first reflective portion.

21. The head gimbal assembly as claimed in claim 18, wherein said main magnetic pole layer is provided in a position on the opposite side to said light-received surface in relation to one of said at least one near-field-light-generating layer, and said near-field-light-generating portion and an end portion in the opposed-to-medium surface side of said main magnetic pole layer are overlapped through a dielectric layer or directly.

22. The head gimbal assembly as claimed in claim 21, wherein said near-field-light-generating portion and said end portion of said main magnetic pole layer are sloped in respect to said element-formed surface in the form that portions in the opposed-to-medium surface side of said near-field-light-generating portion and said end portion are lifted up or pulled down.

23. The head gimbal assembly as claimed in claim 18, wherein said main magnetic pole layer is provided in a position on the light-received surface side in relation to one of said at least one near-field-light-generating layer, and said main magnetic pole layer and the near-field-light-generating layer are in contact with or close to each other only at an end in the opposed-to-medium surface side of said main magnetic pole layer and at a tip of the near-field-light-generating layer reaching the head end surface on the opposed-to-medium surface side.

24. The head gimbal assembly as claimed in claim 18, wherein said at least one near-field-light-generating layer is two near-field-light-generating layers, and two light-received surfaces of said two near-field-light-generating layers are sloped in respect to said element-formed surface in the form that portions in the opposed-to-medium surface side of said two light-received surfaces are lifted up and pulled down respectively, and two tips of said two near-field-light-generating layers reaching the head end surface on the opposed-to-medium surface side are in contact with or close to each other.

25. The head gimbal assembly as claimed in claim 18, wherein an overcoat layer is further provided on said element-formed surface so as to cover said electromagnetic coil element and said at least one near-field-light-generating layer, and a region of said overcoat layer including all the light paths of an incident light propagating from the head end surface opposite to said opposed-to-medium surface to said light-received surface is formed of silicon dioxide or an oxide that consists primarily of silicon dioxide.

26. The head gimbal assembly as claimed in claim 18, wherein an overcoat layer is further provided on said element-formed surface so as to cover said electromagnetic coil element and said at least one near-field-light-generating layer, and a thermal protrusion layer made of a material having a larger coefficient of thermal expansion than that of said overcoat layer is provided close to said near-field-light-generating portion.

27. The head gimbal assembly as claimed in claim 26, wherein said main magnetic pole layer is provided in a position on the opposite side to said light-received surface in relation to one of said at least one near-field-light-generating layer, and said thermal protrusion layer is positioned between said near-field-light-generating portion and an end portion in the opposed-to-medium surface side of said main magnetic pole layer, and is in contact with or close to said end portion.

28. The head gimbal assembly as claimed in claim 26, wherein said main magnetic pole layer is provided in a position on the light-received surface side in relation to one of said at least one near-field-light-generating layer, and said main magnetic pole layer and the near-field-light-generating layer are in contact with or close to each other only at an end in said opposed-to-medium surface side of said main magnetic pole layer and at a tip of the near-field-light-generating layer reaching the head end surface on the opposed-to-medium surface side, and said thermal protrusion layer is positioned on the opposite side to said main magnetic pole layer in relation to said near-field-light-generating portion.

29. The head gimbal assembly as claimed in claim 26, wherein said material of which said thermal protrusion layer is made is a non-magnetic metal.

30. The head gimbal assembly as claimed in claim 18, wherein an overcoat layer is further provided on said element-formed surface so as to cover said electromagnetic coil element and said at least one near-field-light-generating layer, a cavity is formed in a region in the opposite side to the opposed-to-medium surface of said overcoat layer and reaching the head end surface opposite to said opposed-to-medium surface, to which an end portion of an optic fiber for launching a light toward at least one near-field-light generating-layer can be inserted, andsaid cavity has a light-received wall surface for receiving and allowing passage of the light from said optic fiber, said light-received wall surface recessed from the head end surface opposite to said opposed-to-medium surface toward at least one near-field-light-generating layer.

31. The head gimbal assembly as claimed in claim 30, wherein a magnetoresistive effect element for reading data signals is further provided between said element-formed surface and said electromagnetic coil element, and a bottom surface parallel to said element-formed surface of said cavity is positioned above a region on the rear side of said magnetoresistive effect element when viewing from the opposed-to-medium surface side.

32. The head gimbal assembly as claimed in claim 30, wherein a reflective layer is further provided on the light-received surface side of said at least one near-field-light generating-layer, having a third reflecting surface for reflecting a part of incident light that propagates across said light-received wall surface and directing the light toward said light-received surface.

33. The head gimbal assembly as claimed in claim 32, wherein said third reflecting surface is sloped in respect to said element-formed surface so as to reflect a part of incident light that propagates obliquely across said light-received wall surface and direct the light toward said light-received surface.

34. The head gimbal assembly as claimed in claim 30, wherein an antireflective film having a monolayer structure or a multilayered structure is formed on said light-received wall surface.

35. A magnetic disk drive apparatus comprising: at least one head gimbal assembly comprising:a thin-film magnetic head comprising:a substrate having an opposed-to-medium surface and an element-formed surface perpendicular to said opposed-to-medium surface;an electromagnetic coil element for writing data signals, formed on/above said element-formed surface, and having a main magnetic pole layer, an auxiliary magnetic pole layer and a write coil layer; andat least one near-field-light-generating layer for heating a part of a magnetic medium during write operation by generating a near-field light,said at least one near-field-light-generating layer having a shape tapered toward a head end surface on the opposed-to-medium surface side, and comprising a near-field-light-generating portion having a light-received surface and a tip reaching the head end surface on the opposed-to-medium surface side, andsaid light-received surface being sloped in respect to said element-formed surface in the form that a portion in the head end surface side of said light-received surface is lifted up, and being provided in a position where an incident light propagating from a head end surface opposite to said opposed-to-medium surface can reach at least a part of said light-received surface;a support mechanism for supporting said thin-film magnetic head;trace conductors for said electromagnetic coil element;trace conductors for a magnetoresistive effect element when said thin-film magnetic head comprises said magnetoresistive effect element; andan optic fiber for launching a light that propagates across the head end surface opposite to said opposed-to-medium surface;at least one magnetic disk;a light source for providing the light to said optic fiber; anda recording/reproducing and light-emission control means for controlling read and write operations of said thin-film magnetic head to said at least one magnetic disk and for controlling an emitting operation of said light source.

36. The magnetic disk drive apparatus as claimed in claim 35, wherein at least one of said at least one near-field-light-generating layer further comprises a first reflective portion that has a first reflecting surface parallel to said element-formed surface, and is positioned on the opposite side to said opposed-to-medium surface in relation to said near-field-light-generating portion.

37. The magnetic disk drive apparatus as claimed in claim 36, wherein at least one of said at least one near-field-light-generating layer further comprises a second reflective portion that has at least one second reflecting surface with a slope angle in respect to said element-formed surface smaller than that of said light-received surface, and is positioned between said near-field-light-generating portion and said first reflective portion.

38. The magnetic disk drive apparatus as claimed in claim 35, wherein said main magnetic pole layer is provided in a position on the opposite side to said light-received surface in relation to one of said at least one near-field-light-generating layer, and said near-field-light-generating portion and an end portion in the opposed-to-medium surface side of said main magnetic pole layer are overlapped through a dielectric layer or directly.

39. The magnetic disk drive apparatus as claimed in claim 38, wherein said near-field-light-generating portion and said end portion of said main magnetic pole layer are sloped in respect to said element-formed surface in the form that portions in the opposed-to-medium surface side of said near-field-light-generating portion and said end portion are lifted up or pulled down.

40. The magnetic disk drive apparatus as claimed in claim 35, wherein said main magnetic pole layer is provided in a position on the light-received surface side in relation to one of said at least one near-field-light-generating layer, and said main magnetic pole layer and the near-field-light-generating layer are in contact with or close to each other only at an end in the opposed-to-medium surface side of said main magnetic pole layer and at a tip of the near-field-light-generating layer reaching the head end surface on the opposed-to-medium surface side.

41. The magnetic disk drive apparatus as claimed in claim 35, wherein said at least one near-field-light-generating layer is two near-field-light-generating layers, and two light-received surfaces of said two near-field-light-generating layers are sloped in respect to said element-formed surface in the form that portions in the opposed-to-medium surface side of said two light-received surfaces are lifted up and pulled down respectively, and two tips of said two near-field-light-generating layers reaching the head end surface on the opposed-to-medium surface side are in contact with or close to each other.

42. The magnetic disk drive apparatus as claimed in claim 35, wherein an overcoat layer is further provided on said element-formed surface so as to cover said electromagnetic coil element and said at least one near-field-light-generating layer, and a region of said overcoat layer including all the light paths of an incident light propagating from the head end surface opposite to said opposed-to-medium surface to said light-received surface is formed of silicon dioxide or an oxide that consists primarily of silicon dioxide.

43. The magnetic disk drive apparatus as claimed in claim 35, wherein an overcoat layer is further provided on said element-formed surface so as to cover said electromagnetic coil element and said at least one near-field-light-generating layer, and a thermal protrusion layer made of a material having a larger coefficient of thermal expansion than that of said overcoat layer is provided close to said near-field-light-generating portion.

44. The magnetic disk drive apparatus as claimed in claim 43, wherein said main magnetic pole layer is provided in a position on the opposite side to said light-received surface in relation to one of said at least one near-field-light-generating layer, and said thermal protrusion layer is positioned between said near-field-light-generating portion and an end portion in the opposed-to-medium surface side of said main magnetic pole layer, and is in contact with or close to said end portion.

45. The magnetic disk drive apparatus as claimed in claim 43, wherein said main magnetic pole layer is provided in a position on the light-received surface side in relation to one of said at least one near-field-light-generating layer, and said main magnetic pole layer and the near-field-light-generating layer are in contact with or close to each other only at an end in said opposed-to-medium surface side of said main magnetic pole layer and at a tip of the near-field-light-generating layer reaching the head end surface on the opposed-to-medium surface side, and said thermal protrusion layer is positioned on the opposite side to said main magnetic pole layer in relation to said near-field-light-generating portion.

46. The magnetic disk drive apparatus as claimed in claim 43, wherein said material of which said thermal protrusion layer is made is a non-magnetic metal.

47. The magnetic disk drive apparatus as claimed in claim 35, wherein an overcoat layer is further provided on said element-formed surface so as to cover said electromagnetic coil element and said at least one near-field-light-generating layer, a cavity is formed in a region in the opposite side to the opposed-to-medium surface of said overcoat layer and reaching the head end surface opposite to said opposed-to-medium surface, to which an end portion of an optic fiber for launching a light toward at least one near-field-light generating-layer can be inserted, andsaid cavity has a light-received wall surface for receiving and allowing passage of the light from said optic fiber, said light-received wall surface recessed from the head end surface opposite to said opposed-to-medium surface toward at least one near-field-light-generating layer.

48. The magnetic disk drive apparatus as claimed in claim 47, wherein a magnetoresistive effect element for reading data signals is further provided between said element-formed surface and said electromagnetic coil element, and a bottom surface parallel to said element-formed surface of said cavity is positioned above a region on the rear side of said magnetoresistive effect element when viewing from the opposed-to-medium surface side.

49. The magnetic disk drive apparatus as claimed in claim 47, wherein a reflective layer is further provided on the light-received surface side of said at least one near-field-light generating-layer, having a third reflecting surface for reflecting a part of incident light that propagates across said light-received wall surface and directing the light toward said light-received surface.

50. The magnetic disk drive apparatus as claimed in claim 49, wherein said third reflecting surface is sloped in respect to said element-formed surface so as to reflect a part of incident light that propagates obliquely across said light-received wall surface and direct the light toward said light-received surface.

51. The magnetic disk drive apparatus as claimed in claim 47, wherein an antireflective film having a monolayer structure or a multilayered structure is formed on said light-received wall surface.