JPH04205806A - Thin-film magnetic head - Google Patents

Abstract

PURPOSE:To enable increase in magnetic reluctance at a connection part of a gap formation part and upper/lower magnetic layers to be restricted by bending an interlayer insulation layer at the gap formation part and the upper/lower magnetic layer connection part in a direction which is vertical to a plane of the gap formation part and the upper/lower magnetic layer connection part and by terminating one edge of the interlayer insulation layer at the plane. CONSTITUTION:An interlayer insulation layer 21 has one edge on a gap surface at a front core part, is extended in vertical direction to the gap surface from here, and is formed so that the interlayer insulation layer formation surface is twisted near a rear edge of the front core part and is nearly in parallel direction to the gap surface at the rear core part. Further, the interlayer insulation layer 21 is bent in vertical direction again toward a connection surface at an upper/lower magnetic layer connection part and is formed to be terminated at the connection part. On the other hand, an upper magnetic layer 6 is in double structure similarly and a width in track width direction is regulated by a width of a through-hole which is provided at a coil insulation layer 5 at the front core part, thus obtaining a multilayer structure of the upper/lower magnetic layers 6 and 2 without increasing magnetic reluctance.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thin film magnetic head used in a magnetic recording/reproducing device such as a VTR, and particularly to multilayering of upper and lower magnetic layers.

[Conventional technology]

High coercive force media using ferromagnetic metal powder and Fe-AQ-3
High-density magnetic recording is progressing through combination with thin film magnetic heads having thin film cores such as i-based and Co--Nb--Zr based. However, such a thin film magnetic head having a metal core has a problem in that the effective magnetic permeability decreases due to eddy current loss in a high frequency region, resulting in a decrease in head efficiency.

As a method to solve this problem, a multilayer magnetic core structure in which soft magnetic thin films and interlayer insulating films such as 5i-02 films are alternately laminated has been proposed.

As an example of the conventional thin film magnetic head, Fig. 5 (8),
As shown in (b), there is a method described in JP-A-62'-103814.

[Problem to be solved by the invention]

In the above conventional technology, the interlayer insulating film is formed to cross the flow of magnetic flux at the gap forming part and the connection part between the upper and lower magnetic layers, and the magnetic resistance in this area increases, which reduces the reproduction efficiency. There was a problem.

An object of the present invention is to provide a multilayer structure of upper and lower magnetic layers that does not increase magnetic resistance at a gap forming portion and a connecting portion between upper and lower magnetic layers, and a method for manufacturing the same.

[Means to solve the problem]

In order to achieve the above object, the interlayer insulating layer in the gap forming part and the upper and lower magnetic layer connecting parts is bent in a direction perpendicular to the plane of the gap forming part and the upper and lower magnetic layer connecting parts, and one end of the interlayer insulating layer is bent in the plane of the gap forming part and the upper and lower magnetic layer connecting parts. It is designed to terminate.

[Effect]

Such a structure of the interlayer insulating film eliminates the possibility that the magnetic flux crosses the interlayer insulating film, thereby preventing an increase in magnetic resistance, that is, a decrease in efficiency.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4. FIG. 1(a) is a front view of the sliding surface, FIG. 2(b) is a sectional view taken along the line B-B' in FIG. FIG. 4 is a process diagram showing a method for producing the upper magnetic layer of FIG. 1.

1 is a nonmagnetic substrate, 2 is a lower magnetic layer, 21 is an interlayer insulating layer of the lower magnetic layer, and 3 is a lower magnetic layer 2 made of a nonmagnetic layer insulating material.
4 is a gap material, 5 is an insulating layer of the coil conductor 9, 7 is a protective film, and 8 is a protective plate. The lower magnetic layer 2 is 2
A groove formed in a nonmagnetic substrate 1 with a multilayer structure made of layers is patterned into a desired shape and then flattened with a filling material 3 made of a nonmagnetic insulating material.

As shown in FIGS. 1(a) and 1(b), the interlayer insulating layer 21 has one end on the gap surface in the front core section, extends from there in a direction perpendicular to the gap surface, and near the rear end of the front core section, the interlayer insulating layer 21 has one end on the gap surface. The forming surface is twisted so as to be substantially parallel to the gap surface at the rear core portion.

Furthermore, as shown in FIG. 2B, the interlayer insulating layer 21 is formed so as to bend again perpendicularly toward the connecting surface at the upper and lower magnetic layer connecting portion, and to terminate at the connecting portion.

On the other hand, the upper magnetic layer 6 similarly has a two-layer structure, and the width in the track width direction of the front core portion is regulated by the width of a through hole provided in the coil insulating layer 5. The interlayer insulating layer 61 of the upper magnetic layer 6 is formed in exactly the same way as the lower magnetic layer 2. In other words, in the front core part, it starts from the gap plane and extends in a direction perpendicular to the gap plane, in the linear part, it extends in a direction almost parallel to the gap plane, and furthermore, in the upper and lower magnetic layer connection parts, it starts in a direction perpendicular to the connection plane. turn to,
It terminates at the connection surface.

In this way, the upper and lower magnetic layers 6.2 have an interlayer insulating layer 1.21.
Accordingly, the front core part is relative to the gap surface.
The magnetic core is divided in the vertical direction, and in the rear core part, the magnetic core is divided in the stacking direction of the magnetic layers, and in the upper and lower magnetic layer connection part, the magnetic core is divided in the direction perpendicular to the connecting surface, as in the front core part. Since the flowing magnetic flux hardly crosses the interlayer insulating layer 21.61 even in the front core portion and the upper and lower magnetic layer connection portions, the magnetic resistance in these portions does not increase. In other words, the effect of multilayering the magnetic core can be fully utilized.

Furthermore, as is clear from FIG. 1(a), since the ends of the upper and lower magnetic layers are non-parallel to the gap plane, the contour effect can also be reduced.

Next, the manufacturing method of this example will be explained with reference to FIGS. 2 to 4.

FIG. 2 shows the method for manufacturing the lower magnetic layer 2 in the order of steps. This will be explained according to the diagram.

(a) A groove 10 for burying a lower magnetic layer is formed in the nonmagnetic substrate 1 by ion etching. At this time, by appropriately selecting the beam incidence angle, the groove bottom surface of the front core equivalent portion 10' is made non-parallel to the substrate surface.

(b) The lower magnetic layer 2 embedded in the non-magnetic substrate 1 is created by forming a multilayer film of a magnetic layer, an interlayer dielectric layer, and a magnetic layer by sputtering and polishing it to the substrate surface.

(C) The part 2' of the buried lower magnetic layer 2 corresponding to the front core is processed by ion etching so that it has the trunk width Tw. At this time, make sure that the final front core section is located at a position offset to either side in the trunk width direction from the center of the front core equivalent section 2' of the lower magnetic layer embedded in the groove of the non-magnetic substrate. Shift the groove 10' for the front core equivalent part 2' in advance by that amount.)
.

(d) After forming the nonmagnetic insulating material 3 by sputtering,
The substrate surface is polished again to make it flat.

A coil conductor 9 is placed on the lower magnetic layer 2 made in this way.
are insulated by an insulating layer 5, and through holes are formed in the coil insulating layer at the gap forming part and the upper and lower magnetic layer connecting parts.

After forming the gap material 4, the upper magnetic layer 6 is manufactured by the method shown in FIGS. 3 and 4.

FIG. 3 is a process diagram showing a cross-sectional view of the front core portion of the upper magnetic layer corresponding to the cross section taken along the line c-c' in FIG. 2(b).

(a) A lift-off pattern 11 made of polyide resin, which is a highly heat-resistant polymeric material, is formed so that one end is located approximately at the center of the through hole. In case 2, it is easier to lift off later if patterning is performed using reactive ion etching using 02 gas using a metal with sufficient selectivity as a mask material to form substantially vertical pattern edges.

(b) Forming the first upper magnetic layer 6' by sputtering.

(c) Light etching is performed using a magnetic film wet etching solution to remove the low dense layer portion of the first upper magnetic layer 6', and then the interlayer insulating layer 61 is formed by sputtering.

(d) The polyamide system is removed using a wet etchant, and the unnecessary first upper magnetic layer is also removed in the same manner.

(e) A second upper magnetic layer 6'' is formed.

(f) The first and second upper magnetic layers 6', 6'' are patterned into a desired shape by ion etching.

In this way, the front core part is created. Next, a method for manufacturing the upper magnetic layer at the upper and lower magnetic layer connecting portion will be explained with reference to FIG. According to the above explanation, if the lift-off pattern 11' made of polyide resin is placed in the center of the through hole and the steps shown in FIG. 3 are followed, the upper magnetic layer at the connection part of the upper and lower magnetic layers shown in FIG. You can create the shape of

Next, another embodiment of the multilayer magnetic layer according to the present invention is shown in FIG. In this example, the upper magnetic layer has a lift-off pattern 11.
It can be made by placing the through hole in the center. The flowing magnetic flux can be more efficiently concentrated in the gap portion.

In the above embodiments, the coil insulating layer 5 is exposed on the sliding surface (
The width (shape) of the upper magnetic layer 6 is limited by the through hole formed in the coil insulating film 5). As shown in the structure,
Naturally, an example in which the coil insulating layer 5 is not exposed is also conceivable. Further, although an example has been shown in which the upper and lower magnetic layers are two layers, it goes without saying that three or more layers are also possible. Further, the same effect can be obtained even when an insulating magnetic substrate such as ferrite is used instead of the lower magnetic layer 2 and only the upper magnetic layer 6 has the structure of the present invention.

〔Effect of the invention〕

According to the present invention, a multilayer structure of upper and lower magnetic layers can be realized without increasing the magnetic resistance of the gap forming part and the connection part of the upper and lower magnetic layers.

[Brief explanation of the drawing]

FIG. 1(a) is a front view of the sliding surface of the first embodiment of the present invention;
Figure 1(b) is a sectional view taken along line B-B' of Figure 1(a),
The figure is a process diagram showing the manufacturing method of the lower magnetic layer of the present invention, FIGS. 3 and 4 are process diagrams showing the manufacturing method of the upper magnetic layer of the invention,
FIG. 5 is a diagram corresponding to FIG. 1(a) of an embodiment of the cocoon 2 of the present invention,
FIGS. 6(a) and 6(b) show a conventional thin film magnetic head corresponding to FIGS. 1(a) and 1(b), respectively. Explanation of symbols 1: Nonmagnetic substrate, 2: Lower magnetic layer, 21.61 Interlayer insulating layer, 3: Nonmagnetic insulating layer, 4: Gap material, 5: Insulating layer of coil conductor, 9: Coil conductor, 6: Upper magnetic layer layer, 7.
Protective film, 8... Protective plate, 10 - Buried groove for lower magnetic layer, 11.11'... Lift-off pattern $ f [] ((1) B - ■ 1-, s'' Hayabusa 2 eyes $ 3 Figure 4 Dan Hayabusa 5 Lo No. Otsu 1 LA・t59

Claims (1)

[Claims] 1. A thin film magnetic head in which thin films such as a lower magnetic layer, a gap material, a coil conductor layer, and an upper magnetic layer are laminated in a predetermined shape on a non-magnetic substrate, wherein the upper and lower magnetic layers have an interlayer The multilayer film is composed of two or more layers with an insulating layer in between, and the multilayer film includes the interlayer insulating layer at least in the gap forming portion in substantially the same direction as the direction in which the magnetic flux flows and in a direction substantially perpendicular to the gap surface. A thin film magnetic head characterized by being divided into a multilayer film structure by. 2. The thin film magnetic head according to claim 1, wherein the multilayer film includes, at a connection portion between the upper magnetic layer and the lower magnetic layer,
A thin film magnetic head characterized in that the thin film magnetic head is divided into a multilayer film structure by the interlayer insulating layer in substantially the same direction as the direction in which magnetic flux flows and in a direction substantially perpendicular to the connection plane between the upper and lower magnetic layers. 3. A thin film magnetic head according to claim 1 or 2, wherein the lower magnetic layer is an insulating magnetic substrate such as ferrite.