JPH0434712A - Thin film magnetic head - Google Patents

Abstract

PURPOSE:To attain higher recording density by forming an insulation layer and a protection layer with a magnetic material or a nonmagnetic material added with the magnetic material respectively so as to decrease the difference of a permeability between the protection layer and a lower insulation layer and the difference of a permeability between the protection layer and an upper insulation layer, thereby obtaining an excellent frequency characteristic. CONSTITUTION:An insulation layer 3 and a protection layer 4 are made of a magnetic material or a nonmagnetic material added with the magnetic mate rial respectively in a thin film magnetic head laminated subsequently with the insulation layer 3, a lower magnetic layer 4, a gap layer 5, an upper mag netic layer 8 and the protection layer 9 onto a base. Thus, the permeability of the head is larger than that of a conventional magnetic head made of only a nonmagnetic material. Thus, a difference of the permeability at the end of a magnetic pole is reduced more than that of a conventional magnetic head, a dip in the magnetic field at the end of a magnetic pole is evaded, the counter effect is suppressed and a waving event in the frequency characteristic is elimi nated. Thus, higher recording density processing is realized.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a WI film magnetic head manufactured by applying thin film forming technology.

"Prior Art" A conventional example of this type of thin film magnetic head is shown in FIG. This thin-film magnetic head has a thin-film magnetic head element 2 mounted on the front surface of a slider l with its bottom surface 1a (shown as the top surface in FIG. 5) facing a medium such as a magnetic disk. It is made up of the following.

As shown in FIG. 6, which shows a detailed cross-section of the main part, the thin-film magnetic head element 2 uses the striped surface 1b of the slider 1 as a substrate, and has an insulating layer 3, a lower magnetic layer (lower core) 4 on the surface thereof.
, a gap layer 5, a coil conductor 7 encapsulated with an insulating layer 6,
It is formed by sequentially laminating an upper magnetic layer (upper core) 8 and a protective layer (overcoat layer) 9, and each magnetic layer 4, 8
By overlapping the tips of the magnetic layers 4 and 8 with the gap layer 5 in between, the tips of the magnetic layers 4 and 8 form a pair of magnetic poles (balls) 10.
11.

In this case, the lower magnetic layer 4 and the upper magnetic layer 8 are made of a ferromagnetic material such as permalloy, and the insulating layer 3 and the protective layer 9 are made of a material such as AI20, . 5i0
It is made of a non-magnetic material made of an oxide such as No. 2.

"Problems to be Solved by the Invention" By the way, the conventional thin film magnetic head described above has the following problems due to its magnetic characteristics.

That is, in this thin film magnetic head, as schematically shown in FIGS. 7 and 8, the magnetic permeability μm of each magnetic layer 4.8 is sufficiently large, and the magnetic permeability μ2 of other parts is small (usually , μ2=1 in the CGS unit system), therefore, the distribution of magnetic permeability μ becomes sharp at the magnetic pole tip 12.13 (the boundary between the insulating layer 3 and the protective layer 9 at the tip of the magnetic layer 4.8). Things are changing rapidly and dramatically. Therefore, the distribution of the recording magnetic field in this thin film magnetic head has a large dip at the positions of the magnetic pole tips 12° and 13, as shown in FIG.
Since these magnetic pole tips 12.13 are parallel to the gap, the magnetic pole tips 12.13 become a pseudo gap, and a so-called contour effect occurs significantly, and as a result, the first
As shown in Figure 0, a wavy phenomenon of frequency characteristics occurred. As a result, adjacent waveforms are adversely affected and the error rate increases, which is an obstacle to achieving higher recording density.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a thin film magnetic head that can achieve even higher recording density.

"Means for Solving the Problem" The present invention provides a thin film magnetic head in which an insulating layer, a lower magnetic layer, a gap layer, an upper magnetic layer, and a protective layer are sequentially laminated on the surface of a substrate. It is characterized in that the layer and the protective layer are each made of a magnetic material or a nonmagnetic material added with a magnetic material.

"Function" In the thin film magnetic head of the present invention, the insulating layer and the protective layer adjacent to the lower magnetic layer and the upper magnetic layer are respectively formed of a magnetic material or a non-magnetic material to which a magnetic material is added. As a result, their magnetic permeability values are larger than in conventional cases made of non-magnetic materials. As a result, the difference in magnetic permeability at the pole tip is reduced compared to the conventional one, and as a result, the dip in the magnetic field at the pole tip is eliminated, the contour effect is suppressed, and the waving phenomenon in the frequency characteristics is eliminated.

"Embodiment" Hereinafter, an embodiment of the thin film magnetic head according to the present invention will be described with reference to FIGS. 1 to 4.

The thin film magnetic head of this embodiment has a structure similar to that of the conventional one shown in FIGS. 5 and 6, but in this embodiment, the insulating layer 3 and the protective layer 9 are Also, weakly magnetic materials (e.g. Ni-Zn ferrite) or non-magnetic materials doped with magnetic materials (e.g. A1
．． 03 with N1, Co, Fe, etc. added thereto). In order to form the insulating layer 3 and the protective layer 9, the materials mentioned above may be used as a target and sputtered directly onto the surface of the substrate 1 and the surface of the upper magnetic layer 8.

In the thin film magnetic head described above, since the insulating layer 3 and the protective layer 9 are formed of the above materials, the value of the magnetic permeability μ3 of the insulating layer 3 and the protective layer 9 becomes non-magnetic as shown in FIG. As a result, the difference in magnetic permeability at the interface between the insulating layer 3 and the lower magnetic layer 4 and the difference in magnetic permeability at the interface between the upper magnetic layer 8 and the protective layer 9 are It is naturally smaller than the conventional one. As a result, the dip in the recording magnetic field that occurred in the past does not occur (as shown in Section 3), and therefore the contour effect that occurred noticeably in the past is suppressed, and as a result, as shown in FIG. As shown in the figure, the waving in the frequency characteristics is eliminated and excellent frequency characteristics are obtained. As a result, the adverse effects on adjacent waveforms are eliminated, making it possible to achieve even higher recording density.

"Effects of the Invention" As explained in detail above, in the thin film magnetic head of the present invention, the insulating layer and the protective layer are each made of a magnetic material or a nonmagnetic material added with a magnetic material. As a result, the difference in magnetic permeability between the insulating layer and the lower magnetic layer and the difference in magnetic permeability between the protective layer and the upper insulating layer become smaller, and therefore, dips do not occur in the recording magnetic field and the contour effect is suppressed. As a result, it is possible to obtain excellent frequency characteristics, and as a result, it is possible to achieve an even higher recording density.

[Brief explanation of the drawing]

1 to 4 are diagrams for explaining one embodiment of the thin film magnetic head according to the present invention, and FIG. 1 is a diagram schematically showing the main parts of this thin film magnetic head, and FIG. FIG. 3 shows the distribution of magnetic permeability, FIG. 3 shows the distribution of the recording magnetic field, and FIG. 4 shows the frequency characteristics. 5 to 10 show a conventional example of a thin-film magnetic head, in which FIG. 5 is a perspective view showing the overall schematic structure, FIG. 6 is an enlarged cross-sectional view of essential parts of the thin-film magnetic head element, and FIG. 7 is a diagram schematically showing the main part, Figure 8 is a diagram showing the distribution of magnetic permeability, and Figure 9 is a diagram showing the distribution of magnetic permeability.
The figure shows the distribution of the recording magnetic field, and FIG. 10 shows the frequency characteristics. 5...Gap layer, 8...Top magnetic layer, 9...Protective layer, lo, 11...Magnetic pole, 2.13...・Magnetic tip, μ (μm, μ2.μ,)...Magnetic permeability.

Claims (1)

[Claims] In a thin film magnetic head in which an insulating layer, a lower magnetic layer, a gap layer, an upper magnetic layer, and a protective layer are sequentially laminated on the surface of a substrate, the insulating layer and the protective layer are each made of a magnetic material or a magnetic material. A thin film magnetic head characterized in that it is formed of a nonmagnetic material doped with.