JPH0444609A - Thin film magnetic head - Google Patents

Abstract

PURPOSE:To prevent permeability from being lowered and to increase efficiency for recording and reproducing by alternately laminating a soft magnetic layer and an insulated layer in a wavy shape to a gap surface at a gap part to which upper and lower magnetic layers are faced through a gap layer. CONSTITUTION:At the time of recording, signal magnetic fields 13-16 are induced by a signal current impressed to a conductive coil 4 and on a cross section perpendicular to the magnetic fields 13-16 flowing in upper and lower magnetic layers 9 and 2, a soft magnetic layer 11 and an insulated layer 12 are alternately arranged so as not to generate any eddy current. Therefore, since the permeability at a gap part (d) between the layers 9 and 2 is not lowered, the satisfactory recording efficiency can be realized. Next, the satisfactory reproducing efficiency can be realized by the similar cause even at the time of reproducing. At the gap part (d), since a layer 12 forming the structure of laminating the layers 9 and 2 is formed wavy to the gap surface, the gap part (d) can become a pseudo gap and because of azimuth loss, however, any influence caused by the pseudo gap is not generated. Thus, satisfactory recording and reproducing can be executed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a thin film magnetic head used in magnetic recording/reproducing devices and the like.

2. Description of the Related Art In recent years, thin film magnetic heads have been attracting attention in response to higher recording densities and higher data transfer speeds in magnetic recording and reproducing devices.

FIG. 6 shows a cross-sectional view of a conventional thin film magnetic head.

In FIG. 6, the conventional wire-wound thin film magnetic head includes a lower magnetic layer n formed on a non-magnetic substrate 21, an insulating layer n of a predetermined thickness forming a gap on the lower magnetic layer η, and K. A conductive coil is formed so as to be embedded in an insulating layer, and an upper magnetic layer 26 is formed.

With the above configuration, during recording, a signal current is applied to the conductive coil section, thereby recording is performed on the recording medium by the magnetic field generated in the gap section, and during playback, the signal magnetic field flowing in from the gap section on the recording medium is conducted. Detected by coil δ.

Problems to be Solved by the Invention In the conventional wire-wound thin film magnetic head described above, problems such as leakage current loss occur when operating in a high frequency region, and problems such as a decrease in magnetic permeability occur in a high frequency region. It was difficult to record and play back.

In order to solve this problem, a method is known in which a laminated magnetic film is used for the upper magnetic layer 1g122 and the upper magnetic layer, as shown in FIG. I'm being beaten. However, even with such a configuration, the gap portion a1. Eddy current losses in CK' cannot be avoided.

This point will be explained below.

First, during recording, as shown in FIG.

Signal magnetic fields 29, 30.3'l, 32 are induced. The cross section of the lower magnetic main part in the plane perpendicular to the signal magnetic field 31 in the part b of the lower magnetic 122 located below the conductive coil 25 (not shown in FIG. 7) is ! As shown in Figure 8, each soft magnetic layer has a shape in which insulating layers are arranged alternately.
#l! The edge layer 281C prevents the generation of eddy currents. This is conductive, J part located above ile 5 is magnetic @
Kanioishi is also made from the same material. But (7, lower magnetic M212
The two-part magnetic layer 26 has a gap part a facing C and a part F magnetic layer 22 through the gap layer 2), part magnetic ji
126 directly contacts the t-6 rear gap section C. The upper magnetic field 1i12 (5
Further, the cross section of the lower magnetic main part is uniformly formed into a soft magnetic layer n or insulating swelling, as shown in FIG.
In the case of soft magnetism 11127, an eddy current 33 is generated by the signal magnetic field 30, 32, and the magnetic permeability is low in the gap part a and the rear gap part C. In particular, low magnetic permeability in the gap aK in contact with the recording medium is considered to be a factor that reduces recording efficiency. Furthermore, during playback, playback efficiency decreases for the same reason as during recording.

For the reasons mentioned above, it has been difficult to achieve sufficient recording and reproducing efficiency with conventional thin film magnetic/hoods.

In addition, the F part magnetic layer n and the e-line layer 3 in the upper magnetic layer 3 are configured parallel to the gap 1123, and the insulating layer exposed on the tape sliding surface becomes a pseudo gap, and this pseudo gap part Unnecessary recording/reproduction was performed, and there was a problem with good recording/reproduction due to poor C/N ratio.

The present invention is intended to solve the problems mentioned above, and is concerned with the decrease in magnetic permeability in the high frequency region due to eddy current loss in the upper magnetic layer of the gap part and the magnetic layer of the lower part, and the influence of the pseudo gap 1j< The object is to provide a thin film magnetic head that can obtain good recording and reproducing characteristics.Means for solving the problem of 3㎜mu In order to solve the above problems, the thin film magnetic head of the present invention has the following features:
The first magnetic layer and the lower magnetic layer have a structure in which soft magnetic layers and insulating layers are alternately laminated, and the upper magnetic layer and the lower magnetic layer of the magnetic circuit consisting of the upper magnetic layer, the gap layer, and the lower magnetic layer. Small fL where F section magnetic - faces through front & 4 gap ring
At least in the gap part, the soft magnetic layer and the insulating layer of the laminated magnetic film constituting the upper magnetic layer and the lower magnetic layer are alternately formed into a wave shape or a polygonal shape having no plane parallel to the gap surface with respect to the gap surface. It has a laminated structure.

Effect With the above configuration, the soft magnetic regions and the insulating layers are alternately laminated in a wavy shape with respect to the gap surface or a polygonal shape with a surface parallel to the gap surface, so that the direction of the magnetic field flowing through the gap portion is A: The vertical cross-section of the upper magnetic layer and the F section magnetic field has a shape in which soft magnetic regions and insulating layers are alternately arranged, which inhibits the generation of vortex 11 flow and reduces magnetic permeability. figure.

Good recording and reproducing efficiency can be obtained. In addition, the insulating layer in the laminated magnetic film constituting the upper magnetic layer and the lower magnetic layer has a wavy shape with respect to the gap plane at the gap portion, or a polygonal line shape with a plane parallel to the gap plane. Therefore, even if the insulating layer becomes a pseudo-gap, good recording and reproducing is possible without causing azimuth loss due to the pseudo-gap.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 (a, l is a plan view of a thin film magnetic head in the first embodiment of the present invention, FIG. 1 (b) is a cross-sectional view of A--A in FIG. Figure (e) is Figure 1 (a) K
It is a BB' sectional view in . Figure 1 (al (bl)
(In d, in the thin film magnetic head, a lower magnetic layer 2 is formed on a non-magnetic substrate 1, a conductive coil 4 is formed via a first insulating layer 3, and a conductive coil 4 is formed on a second insulating layer 5. is insulated from the upper magnetic layer 9. In the gap part d, the upper magnetic layer 9 and the lower magnetic layer 2 face each other with the gap layer 7 in between, and in the rear gap part f, the upper magnetic layer 9 and the lower magnetic layer 2 are in contact.

As shown in FIG. 2, the upper magnetic layer 9 and the lower magnetic layer 2 are
e Consisting of a laminated magnetic film in which a magnetic layer 11 and an insulating layer are laminated, and a gap portion d where the upper magnetic layer 9 and the lower magnetic layer 2 face each other via a gap layer (not shown in FIG. 2). The upper magnetic layer m9 and the lower magnetic layer 2 have a structure in which soft magnetic layers 11 and insulating layers 12 are alternately laminated in a wavy shape with respect to the gap plane.

With the above structure, no eddy current is generated in the upper magnetic layer 9 and the lower magnetic layer 2 in the gap d, so there is no decrease in magnetic permeability, and good recording and reproducing efficiency can be obtained. Regarding this, the second
This will be explained using the diagram and FIG.

First, during recording, a signal current applied to the conductive coil 4 creates a signal magnetic field 13, 14, 15, as shown in FIG.
．． 16 is induced. The cross section in the direction perpendicular to the signal magnetic field 13 flowing through the upper magnetic layer 9 located above the conductive coil 4 is as follows:
As shown in FIG. 3, since the soft magnetic layers 11 and the insulating layers 12 are alternately arranged, no eddy current is generated.

The same applies to the signal magnetic field 15 flowing through the lower magnetic layer 2 located below the conductive coil 4. Furthermore, the signal magnetic field 1 flowing through the upper magnetic layer 9 and the lower magnetic layer 2 in the gap portion d
4, the soft magnetic layers 11 and the insulating layers 12 are alternately arranged, so that no eddy current occurs. Therefore, since the magnetic permeability at the gap d between the upper magnetic layer 9 and the lower magnetic layer 2 does not decrease as in the conventional case, good recording efficiency can be achieved. Next, during reproduction, for the same reason, the magnetic permeability at the gap d between the upper magnetic layer 9 and the lower magnetic layer 2 does not decrease.
Good playback/recording efficiency can be achieved. Furthermore, in the gap part d, the insulating layer 12 forming the laminated structure of the upper magnetic layer 9 and the lower magnetic layer 2 has a wave-like shape with respect to the gap surface.
Although it can be a pseudo gap, the effect of the pseudo gap does not occur due to azimuth loss. Therefore, good recording and reproduction can be performed.

Note that in this embodiment, the upper magnetic layer 2 and the lower magnetic layer 9
It was only in the gap part d that the upper magnetic layer 2 and the lower magnetic layer 9 were laminated in a wave-like shape in the same way as in the gap part d, so that the rear gap part f was laminated in a wave-like shape. It is possible not to reduce the magnetic permeability in the gap part f, and it is possible to further improve the recording and reproducing characteristics.

Moreover, the conductive coil 4 of the upper magnetic layer 2 and the lower magnetic Mlt9
Similarly to the gap portion d, in the portion e located above and below the layer, even if the layers are laminated in a wave-like shape, the cross section in the direction perpendicular to the flow of the magnetic field shows that the soft magnetic layer 11 and the insulating layer 12 are arranged alternately. Therefore, no eddy current is generated and no decrease in magnetic permeability occurs. Therefore, good recording and reproducing efficiency can be achieved even if all the upper and lower magnetic layers are laminated in a wave-like shape.

Next, a second embodiment will be described using FIG. 5.

FIG. 5 (at is a plan view of the thin film magnetic head in the second embodiment, FIG. 5 1al is a DD degree cross-sectional view in FIG. 5 is a cross-sectional view taken along the line EE' in FIG. 1, and the same components as in FIG. The magnetic layer consists of a laminated magnetic film in which a soft magnetic layer 17 and an insulating layer 18 are laminated, and the upper magnetic layer 1119 and the lower magnetic layer 1117 are formed in a polygonal shape with no plane parallel to the gap plane at the gap g. It has a structure in which insulating layers 18 are stacked alternately.

By configuring in this way, similar to the first embodiment,
1frrr in the direction perpendicular to the flow of the magnetic field at the gap g
Since the U has soft magnetic layers 17 and insulating layers 18 arranged alternately, no eddy current is generated and no decrease in magnetic permeability occurs. Furthermore, since the insulating layer 18 has a polygonal line shape that does not have a plane parallel to the gap plane, it may become a pseudo gap, but the effect of the pseudo gap does not occur due to azimuth loss. Therefore, good recording and reproduction can be performed.

In addition, the portion 1 of the upper magnetic layer 19 and the lower magnetic layer located below the conductive coil 4 also has a surface parallel to the gap plane (i shape 17) similar to the gap layer g. However, since no eddy current is generated and no decrease in magnetic permeability occurs, all parts of the F section magnetic layer 19 and the upper magnetic layer (A), including the rear gap layer, are Similarly to the first embodiment, good recording and reproducing efficiency can be achieved even when the layers are stacked in a straight line shape without parallel to the gap plane.

Effects of the Invention As described above, according to the thin film magnetic head of the present invention, the upper magnetic layer consisting of the laminated magnetic film consisting of the soft magnetic layer and the insulating layer are laminated alternately. Soft magnetic layers and insulating layers are alternately stacked in a wave-like shape or a polygonal line shape parallel to the gap direction without Ni at least on the opposing gears and the fub portion. By using a horizontal structure, it is possible to prevent a decrease in magnetic permeability caused by eddy current loss flowing through the gap layer, thereby increasing the recording and reproducing efficiency.

In addition, it is doubtful that the nub sliding surface (the exposed upper magnetic layer and the insulation in the film of the laminated magnetic It is said that if the shape or gap surface has a flat surface and a polygonal line shape with no flat surface is exposed, the influence of the gap can be ignored and good recording and playback can be performed. It's something to sniff at.

[Brief explanation of the drawing]

FIG. 1 (al fb) fe) is a ψ plane view of the thin film magnetic head in the first embodiment of the present invention; FIG. 1 (a) vc
Figure 2 is a perspective view of the laminated magnetic layer of the same # film magnetic hematome, and Figures 3 and 4 are the magnetic layer of the same f5 thin film magnetic head. Cross-sectional view, Fig. 5 (aM'b) (e) P Plan view of the W# film magnetic head in the second embodiment, Fig. 5 (a) - pHlT plane view, E-E' Cross-sectional view 7゜Figure 6 is a cross-sectional view of a conventional thin film magnetic head.
The figure is a perspective view of a laminated magnetic layer in a conventional thin-film magnetic head, and FIGS. 8 and 9 are cross-sectional views of the laminated magnetic layer in a conventional thin-film magnetic head. 2.20...lower magnetic layer, 7-...gap layer, 9,
19...Top magnetic layer,], 1, 1.7...Soft magnetic layer, 12.18...Insulating layer,...Yoshihiro Morimoto, agent of Gyakno Department Figure 1cj) dρ 4le, Upward N, 7' interception, the first cause! ! 3 C Figure 1 (/+ Figure 5 + b) Figure 2

Claims (1)

[Claims] 1. A thin film magnetic head provided with an upper magnetic layer and a lower magnetic layer made of a laminated magnetic film having a structure in which soft magnetic layers and insulating layers are alternately laminated, wherein the upper magnetic layer, the gap layer, and the lower magnetic layer a soft magnetic layer and an insulating layer of the laminated magnetic film forming the upper magnetic layer and the lower magnetic layer at least at a gap portion where the upper magnetic layer and the lower magnetic layer of the magnetic circuit face each other with the gap layer interposed therebetween; A thin-film magnetic head having a structure in which the layers are alternately stacked in a wave-like shape with respect to the gap plane or in a polygonal line shape with no plane parallel to the gap plane.