JP4490579B2 - Inductive thin film magnetic head and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an inductive thin film magnetic head used for recording.
[0002]
[Prior art]
2. Description of the Related Art In recent years, magnetic heads used in magnetic disk devices have been increasing in density and efficiency with respect to recording media, and their shapes are becoming increasingly smaller and more accurate.
[0003]
In order to meet such demands, the magnetic field at the tip of the magnetic pole that contributes to magnetic recording of the inductive thin film magnetic head must be large, and the track width must be narrowed and increased in accuracy. In order to solve this problem, the use of high Bs material at the magnetic pole end to increase the magnetic field of the inductive thin-film magnetic head, and improvement of the head structure for high accuracy of the track width are considered. And described in Japanese Patent Laid-Open No. 2000-155906.
[0004]
[Problems to be solved by the invention]
As described above, the inductive thin film magnetic head described in Japanese Patent Laid-Open No. 2000-155906 seems to have a limited recording magnetic field, and the present invention provides a higher recording magnetic field and a higher track width. It is in.
[0005]
For this purpose, the present invention focuses on the head structure and provides a structure in which the magnetic flux is concentrated on the tip of the magnetic pole.
[0006]
In addition, the present invention provides a structure in which an upper magnetic pole end layer for determining a track width is formed on a flat portion to improve the track width.
[0007]
[Means for Solving the Problems]
In the inductive thin film magnetic head according to the present invention, in order to realize a narrow track and a high recording magnetic field, a lower magnetic pole end layer is disposed on the lower magnetic core, and an upper magnetic pole end layer is disposed below the upper magnetic core. The pole end layer is formed on the flat portion. Furthermore, in order to reduce the leakage magnetic field from the magnetic pole end, the lower magnetic pole end layer is etched (trimmed) into a predetermined shape using the upper magnetic pole end layer as a mask.
[0008]
In the inductive thin film magnetic head of the present invention, in order to increase the recording magnetic field, the thickness of the lower magnetic pole end layer is 1.0 μm or more, and the length Gd (depth) of the lower magnetic pole end layer that determines the gap depth is 0.5 μm. The above is preferable. The length Ly from the air bearing surface of the upper magnetic pole tip layer to the spreading position is smaller than the length Gd of the lower magnetic pole tip layer, and the length Gd of the lower magnetic pole tip layer is smaller than the length from the air bearing surface of the upper magnetic pole tip layer. . Further, the thickness of the upper magnetic pole end layer may be 2 μm or more. The upper and lower magnetic pole end layers have a saturation magnetic flux density higher than that of the upper magnetic core or the lower magnetic core, and the saturation magnetic flux density is 1.6 T or more. Further, it is desirable that the tip of the upper magnetic core is receded by 0.5 to 2 μm from the air bearing surface. Furthermore, the trimming depth of the lower magnetic pole end layer is preferably 0.2 ± 0.1 μm, and the etching taper angle is preferably 5 ° to 20 °.
[0009]
Also, the lower magnetic core formed on the substrate, the lower magnetic pole end layer formed on the lower magnetic core, and the upper magnetic pole end layer formed on the lower portion of the upper magnetic core are coupled at the front end portion through the gap film. The lower magnetic core and the upper magnetic core are coupled at the rear end, and are formed between the coil disposed around the upper magnetic core and the lower magnetic core, and the coil, the lower magnetic core, and the upper magnetic core. An induction type thin film magnetic head having an insulating layer has a shape in which the width of the lower magnetic pole end layer on the air bearing surface changes in two or more steps.
[0010]
Also, the lower magnetic core formed on the substrate, the lower magnetic pole end layer formed on the lower magnetic core, and the upper magnetic pole end layer formed on the lower portion of the upper magnetic core are coupled at the front end portion through the gap film. The lower magnetic core and the upper magnetic core are coupled at the rear end, and the coil is disposed around the upper magnetic core and the lower magnetic core, and the insulation is formed between the coil and the lower magnetic core and the upper magnetic core. In an induction type thin film magnetic head having a layer, the length of the upper magnetic pole end layer is longer than the length of the lower magnetic pole end layer.
[0011]
Also, the lower magnetic core formed on the substrate, the lower magnetic pole end layer formed on the lower magnetic core, and the upper magnetic pole end layer formed on the lower portion of the upper magnetic core are coupled at the front end portion through the gap film. The lower magnetic core and the upper magnetic core are coupled at the rear end, and are formed between the coil disposed around the upper magnetic core and the lower magnetic core, and the coil, the lower magnetic core, and the upper magnetic core. In an inductive thin film magnetic head having an insulating layer, the upper magnetic pole end layer is formed on a surface having a step size of 0.15 μm or less.
[0012]
In addition, a magnetic head can be configured using these induction type magnetic heads as recording heads. The magnetic head can be applied to a magnetic disk device. Also, the present invention can be applied to a magnetic disk array device in which a plurality of magnetic disk devices are connected.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
One embodiment of an inductive thin film magnetic head according to the present invention is shown in FIGS. FIG. 1 is a perspective view of an inductive thin film magnetic head, and FIG. 2 is a sectional view of the inductive thin film magnetic head. Since the present invention may be in an inductive thin film magnetic head, the structure and description of the reproducing head formed thereunder are omitted.
[0014]
It consists of a lower magnetic core 1 and an upper magnetic core 2 on a substrate, and a coil 3 arranged around the lower magnetic core and the upper magnetic core. The lower magnetic core and the upper magnetic core are back contact portions 4 at the rear end. And the tip is connected via the pole tip layer 5. The coils are insulated by a photoresist insulating film 10. The magnetic pole tip layer 5 is composed of a laminated film of a lower magnetic pole end layer 6, an upper magnetic pole end layer 7 and a gap layer 8. After forming the lower magnetic pole end layer 6, an alumina insulating layer 9 is formed so as to embed the lower magnetic pole end layer 6, the surface is flattened by CMP, and the write gap layer 8 is formed on the flat surface. Since the upper magnetic pole end layer for determining the track width is formed on the flat surface, the track width accuracy is improved. Although there is almost no step due to planarization by CMP, there may be a slight step depending on the CMP conditions and the film state. In this example, a step of 0.15 μm or less may occur. With such a level difference, the pattern accuracy is hardly deteriorated. However, in the structure in which the Gd position is determined by the conventional photoresist, the step of the magnetic pole forming portion is larger than 0.15 μm as compared with the present invention, and it is difficult to improve the track width accuracy when the step is formed on such a step.
[0015]
Further, by providing the lower magnetic pole end layer, it is possible to provide a high recording magnetic field by optimizing its shape and film thickness, and by trimming the lower magnetic pole end layer to a predetermined shape, the lower magnetic pole end layer can be provided. A magnetic field (herein expressed as a side peak) generated at the end of the layer can be reduced. The bottom pole tip layer for achieving these will be described in detail below.
[0016]
If the film thickness of the lower magnetic pole end layer 6 is 1.0 μm or more from the viewpoint of magnetic field calculation, the recording magnetic field becomes almost constant. Further, the magnetic field strength increases as the length in the depth direction (gap depth: Gd) from the air bearing surface of the lower magnetic pole end layer 6 decreases. However, Gd = 0.5 to 2.0 μm is optimal in terms of Gd processing accuracy and ease in forming the lower magnetic pole end layer 6 by plating technology.
After forming the lower magnetic pole end layer 6 in a desired shape and size, an alumina film 9 is formed and planarized by a CMP process. A magnetic gap film 8 and an upper magnetic pole end layer 7 are formed thereon.
[0017]
The upper magnetic pole end layer 7 may be a high saturation density material CoNiFe single layer film, or a CoNiFe / 46NiFe, CoNiFe / 80NiFe two layer film. At this time, CoNiFe which is a high saturation density material is arranged on the magnetic gap side. Even when the two-layer film is used in this way, the magnetic field strength is hardly lowered by arranging CoNiFe which is a high saturation density material on the magnetic gap side. In the case of such a two-layer film, the CoNiFe film thickness needs to be at least 1.0 μm. Since the track width is determined by the width of the upper magnetic pole end layer 7 and is formed on the flat portion as described above, the track width accuracy is improved.
[0018]
Further, the magnetic field strength affects the shape of the upper magnetic pole end layer in addition to the film thickness. FIG. 3 shows a plan view of the upper magnetic pole end layer. This affects the spread angle θ1 of the top pole end layer 7. The spread angle is desirably in the vicinity of 30 ° to 45 °. Ly is the length from the air bearing surface to the spreading position of the upper magnetic pole end layer, and Gd is the length of the lower magnetic pole end layer from the air bearing surface.
[0019]
Next, the upper part of the lower magnetic pole end layer is trimmed using the upper magnetic pole end layer 7 as a mask. As a result, the magnetic field strength can be increased and the leakage magnetic field generated at the end of the lower magnetic pole end layer can be reduced. FIG. 4 shows the shape of the bottom pole end layer after trimming. The trimming depth t1 may be a magnetic field strength of 0.1 to 0.2 [mu] m. The magnetic field strength depending on the shape of the bottom pole end layer is shown in FIG. The horizontal axis in the figure is the film thickness of the upper magnetic pole end layer UP0t. The magnetic field strength Hx is 46NiFe (saturation magnetic flux density Bs: 1.68T) for the lower magnetic core, CoNiFe (Bs: 2.0T) for the lower magnetic pole end layer, CoNiFe (Bs: 2.0T) for the upper magnetic pole end layer, and the upper magnetic core. Using 46NiFe (Bs: 1.68T), the thickness is 2.0, 1.5, 2.0, 1.0-3.0μm, track width is 0.35μm, magnetomotive force is 0.36ampere turn, and flying height is 25nm. is there. As is clear from this, the film thickness of the upper magnetic pole end layer may be 2.0 μm or more. The structure shown in FIG. 4B has a higher magnetic field strength of about 200 Oe. However, it has been confirmed that the structure of FIG. Further, it has been confirmed that the structure shown in FIG. 4B has a smaller unnecessary side peak from the end portion of the magnetic pole. The taper angle θ2 of the structure of FIG. 4B may be 5 to 20 ° in consideration of the process.
[0020]
After the upper magnetic pole end layer is formed and trimmed, a coil is formed and the coils are insulated by the photoresist insulating film 10. As this insulating film, not only a photoresist but also an inorganic film such as alumina, SiO 2 or SiN, or an organic film such as SOG can be used. Also, these can be stacked or combined. After the coil and the insulating film are formed in a desired shape, the upper magnetic core is formed in a desired shape. As a method for forming the upper magnetic core, the frame plating method is optimal. In addition, after forming a magnetic film by a sputtering method, it may be etched into a predetermined shape by an ion milling method.
[0021]
The upper magnetic core is preferably set back from the air bearing surface. If it comes out to the air bearing surface, there is a concern about the influence of the leakage magnetic field from the end of the upper magnetic core. Further, if the upper magnetic core is retracted too much from the air bearing surface, the maximum magnetic field strength may be reduced. Considering the above points and process, the position of the upper magnetic core is preferably 0.5 to 2.0 μm from the air bearing surface.
[0022]
The inductive thin film recording head having the structure of the present invention is completed through the above steps. Therefore, the magnetic field strength when an induction type thin film recording head is manufactured according to the manufacturing process of the present invention will be described.
[0023]
In the inductive thin film recording head having the structure of the present invention, 46NiFe (saturation magnetic flux density Bs: 1.68T) is formed in the lower magnetic core, CoNiFe (Bs: 1.9 to 2.2T) is formed in the lower magnetic pole end layer, and CoNiFe (Bs: 1.9 ~ 2.2T), 46NiFe (Bs: 1.68T) is used for the upper magnetic core, the film thickness is 2.0, 1.5, 2.0, 3.0μm respectively, track width 0.35μm, Gd = 1.0μm, magnetomotive force 0.36 amp ・FIG. 6 shows the magnetic field strength when the turn and the flying height are 25 nm. The abscissa in the figure is the distance Ly from the floating surface of the upper magnetic pole end layer to the spreading position. The magnetic field strength increases as Ly is reduced.
[0024]
In this structure, Ly can be arbitrarily set as compared with the conventional structure, and Ly can be made smaller than the conventional structure, so that the magnetic field strength can be increased. Conventionally, a resist pattern for forming an upper magnetic pole end layer is formed on a photoresist step, so that halation and resist film thickness distribution are generated, which may cause problems such as dimensional variation. However, in the present invention, such a problem can be prevented by forming the upper magnetic pole end layer on the flat portion, so that Ly can be set arbitrarily. When Gd = 0.5 to 1.5 μm, it is possible to satisfy Ly <Gd from the viewpoint of magnetic field strength.
[0025]
As is clear from this, when 2.0 T is used for the lower magnetic pole end layer and the upper magnetic pole end layer, the maximum magnetic field strength at Ly = 0.5 μm is about 800 kA / m (10000 Oe).
[0026]
In this way, the maximum magnetic field strength tends to increase as Bs increases, especially in the upper magnetic pole end layer and the lower magnetic pole end layer, where Bs is larger than the upper magnetic core and lower magnetic core, here the conventional 46NiFe It is desirable to use a material having a large Bs (Bs: 1.6 to 1.7 T or more) because the maximum magnetic field strength and magnetic field gradient can be improved.
[0027]
FIG. 7 shows another embodiment of the present invention. Since the coil is formed after the top pole end layer 7 and the back contact portion 4 are formed and then flattened, the coil can be easily formed. At this time, the features of the present invention are utilized as they are.
[0028]
【The invention's effect】
According to the present invention, a recording head having a high recording magnetic field strength can be provided. In addition, a recording head with high track width accuracy can be provided. In addition, a magnetic recording / reproducing apparatus capable of writing on a high coercive force medium can be provided.
[Brief description of the drawings]
FIG. 1 is a perspective view of an inductive thin film magnetic head of the present invention.
FIG. 2 is a sectional view of an inductive thin film magnetic head according to the present invention.
FIG. 3 is a plan view of the shape of an upper magnetic pole end layer of the induction type thin film magnetic head of the present invention.
FIG. 4 is a cross-sectional shape of a bottom pole end layer after trimming according to the present invention.
FIG. 5 is a relationship between the magnetic field strength Hx and the top pole tip layer thickness Up0t according to the shape of the bottom pole tip layer of the present invention.
FIG. 6 is a relationship between the magnetic field strength Hx of the induction type thin film magnetic head of the present invention and the spread position Ly of the top pole end layer.
FIG. 7 is a cross-sectional view of an inductive thin film magnetic head according to another embodiment of the present invention.
[Explanation of symbols]
1: Lower magnetic core 2: Upper magnetic core 3: Coil 4: Connection 5: Magnetic pole tip layer
6: Lower magnetic pole end layer 7: Upper magnetic pole end layer 8: Gap film 9: Alumina film
10: Photoresist insulation film.

Claims (4)

A lower magnetic core formed on a substrate; a lower magnetic pole end layer formed on an air bearing surface side of the lower magnetic core and trimmed to a predetermined shape; and an inorganic formed on a rear portion of the lower magnetic pole end layer An insulating layer, a gap layer formed on the planarized upper surface of the lower magnetic pole end layer and the inorganic insulating layer, an upper magnetic pole end layer formed on the air bearing surface side of the gap layer, and an upper magnetic pole end layer An upper magnetic core that is magnetically coupled to a position retracted from the air bearing surface and magnetically coupled to the lower magnetic core at a rear end, and circulates the upper magnetic core and the lower magnetic core a coil formed, an insulating layer formed between the coil and the lower magnetic core and the upper magnetic core,
The length from the air bearing surface of the upper magnetic pole end layer is larger than the length from the air bearing surface of the lower magnetic pole end layer, and the length from the air bearing surface where the width of the upper magnetic pole end layer is widened is the lower magnetic pole layer. Smaller than the length from the air bearing surface of the extreme layer,
In the air bearing surface, the width of the lower magnetic pole end layer has a portion larger than the width of the upper magnetic pole end layer,
An induction type thin film magnetic head characterized in that a width of the upper magnetic pole end layer facing the portion left by trimming of the lower magnetic pole end layer is substantially the same. A lower magnetic core formed on a substrate; a lower magnetic pole end layer formed on an air bearing surface side of the lower magnetic core and trimmed to a predetermined shape; and an inorganic formed on a rear portion of the lower magnetic pole end layer An insulating layer, a gap layer formed on the planarized upper surface of the lower magnetic pole end layer and the inorganic insulating layer, an upper magnetic pole end layer formed on the air bearing surface side of the gap layer, and an upper magnetic pole end layer An upper magnetic core that is magnetically coupled to a position retracted from the air bearing surface and magnetically coupled to the lower magnetic core at a rear end, and circulates the upper magnetic core and the lower magnetic core a coil formed, an insulating layer formed between the coil and the lower magnetic core and the upper magnetic core,
The length from the air bearing surface of the upper magnetic pole end layer is larger than the length from the air bearing surface of the lower magnetic pole end layer, and the length from the air bearing surface where the width of the upper magnetic pole end layer is widened is the lower magnetic pole layer. Smaller than the length from the air bearing surface of the extreme layer,
An induction type thin-film magnetic head, wherein the lower magnetic pole end layer has a side surface perpendicular to a surface facing the upper magnetic pole end layer and a taper-shaped side surface on the air bearing surface. Forming a lower magnetic core on the substrate;
Forming a lower magnetic pole end layer on the air bearing surface side of the lower magnetic core;
Forming an inorganic insulating layer so as to embed the lower magnetic pole end layer;
Planarizing the surfaces of the bottom pole tip layer and the inorganic insulating layer;
Forming a gap layer on the planarized surface;
Forming an upper magnetic pole end layer on the air bearing surface side of the gap layer, the length from the air bearing surface being longer than the lower magnetic pole end layer;
Trimming the lower magnetic pole end layer into a predetermined shape;
Forming a coil on top of the gap layer behind the top pole tip layer;
Forming an insulating layer between and above the coils;
Forming an upper magnetic core that is magnetically coupled to a position retracted from the air bearing surface of the upper magnetic pole end layer, covers the insulating layer on the coil, and is magnetically coupled to the lower magnetic core at the rear end; ,
Have
The upper magnetic pole end layer has a portion having a constant width from the air bearing surface to the rear portion and a portion in which the width increases, and the length from the air bearing surface at the position where the width is increased is the air bearing surface of the lower magnetic pole end layer. Smaller than the length from
The method of manufacturing an inductive thin film magnetic head, wherein the lower magnetic pole end layer has a side surface perpendicular to a surface facing the upper magnetic pole end layer and a taper-shaped side surface on the air bearing surface. 4. The method of manufacturing an induction type thin film magnetic head according to claim 3 , wherein in the trimming step, the lower magnetic pole end layer is formed in a predetermined shape using the upper magnetic pole end layer as a mask.

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