JPH03100910A - Thin-film magnetic head - Google Patents

Abstract

PURPOSE:To obtain an exact track width and to prevent the generation of voids in a magnetic layer by setting the width of the intermediate core in a front part lager than the width of a lower core or upper core and regulating the width of tracks by the width of the lower core or the upper core. CONSTITUTION:The thin-film magnetic head 50 is stacked with a lower insulating layer 32a, an intermediate insulating layer 32b and an upper insulating layer 32c. The magnetic layer formed at the prescribed point in these insulating layers forms a magnetic circuit. The width of the intermediate core 31 is set larger than the width of the lower core 12 and the track width is regulated by the width of the core 12. The width of the core 31 is formed sufficiently larger than the necessary track width (t) in such a manner, by which this width can be made coincident with the actual track width. In addition, the formation of the voids in the core 31 is obviated. The core 13 and the core 12 are shut off by the core 31 and the formation of a pseudo gap in the insulating layer parts of the core 12 and the core 13 is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a thin film magnetic head for a magnetic recording/reproducing device.
In particular, the present invention relates to an 'R' film magnetic head for high-density magnetic recording.

(Conventional technology) Conventional thin-film magnetic heads use vacuum thin-film formation technology, etc.
A magnetic circuit was constructed by forming a magnetic layer, processing it into a predetermined core shape by photolithography, etching, etc., and forming the magnetic layer via a coil, an insulating layer, etc.

3(A) to 3(B) are diagrams showing a conventional thin film magnetic head 10, in which FIG. 3(A) is a schematic plan view showing a recording medium sliding surface, and FIG. ) is a schematic cross-sectional view taken along the line A-A of FIG.

In the figure, 11 is a substrate made of an insulator;
1 is a lower core formed on the substrate, and 13 is an upper core.

One end portions of both cores are joined to each other via a nonmagnetic material 14 to form a magnetic gap 16 on the recording medium sliding surface 15, and the other end portions are directly joined to each other to form a rear joint portion 17.

A spiral coil pattern 1 is provided in a space where the upper core 13 and the lower core 12 face each other with a non-magnetic material 14 and an insulating layer 18 interposed therebetween.
9 is formed to surround the rear joint portion 17. Connection patterns 20 and 21 are formed at the starting end and the ending end of this coil pattern 19. This connection pattern 20.21 is formed on the non-magnetic material 14.

Further, the coil pattern 19 is covered with an insulating layer 22, and in order to electrically connect the connection pattern 20.21 to another device, the connection pattern 20 (or 21) must be inserted from above this insulating layer 22. A lead wire 23 is provided which is bent over the entire length.

In this conventional thin-film magnetic helad 10, the horizontal width of the recording medium sliding surface 15 at the joint where the upper core 13 and the lower core 12 are joined via the non-magnetic material 14 is equal to the track width. (hereinafter referred to as "track width").

Next, a method of manufacturing such a conventional thin film magnetic head 10 will be explained.

First, a magnetic film is formed on the substrate 11, and the lower core 12 is formed by well-known photolithography, etching, or the like.

On top of that, a non-magnetic material 14 is formed so that the end will become the later magnetic gap 16, and unnecessary parts are removed using photolithography, etching, etc. Next, an insulating layer 18 is formed. A coil pattern 19 is formed, and unnecessary portions are removed using photolithography, etching, etc. in the same manner as described above.A conductor layer is formed thereon, and a coil pattern 19 is formed using photolithography, etching, etc. Form.

An insulating layer 22 is formed on the stepped coil formation surface on which the coil pattern 19 is formed, and unnecessary portions are
Similar to the above, it is removed using a photolithography method, an etching method, or the like.

Next, a magnetic layer is formed using a vacuum thin film forming technique to create the lower core 12 and the connecting portion 17 in the inner periphery of the coil pattern 19, and then, as before, unnecessary portions are removed and the upper A core 13 is formed.

In actual use, a protective film 24 of, for example, Al2O3 is formed on the upper surface.

In this conventional thin film magnetic head 10, the insulating layer 18
Since the insulating layer 22 is formed on the coil pattern 19 having a step, and the upper core 13 is further formed on this insulating layer 22, the step becomes larger as the layers are stacked.

On a surface with such a step difference, the resolution obtained by photolithography becomes extremely poor, and the resolution is limited to the size of the step difference. Therefore, even if an attempt is made to reduce the pitch interval of the coil pattern 19 in order to increase the number of turns of the coil, it cannot be made smaller due to poor resolution, and as a result, the length of the upper and lower cores 12 and 13 formed above and below the coil pattern 19 is increased. However, as the magnetic path length increases, the magnetic resistance increases, resulting in poor performance as a thin film magnetic head.

Therefore, the magnetic circuit is made up of at least a lower core, an upper core, and a front and rear intermediate core that connect them, and a connecting portion between the front intermediate core and the upper core or a connecting portion between the front intermediate core and the lower core. A thin film magnetic head in which a magnetic gap is formed in any one of the above, wherein each core of the lower core, the upper core, and both intermediate cores is made of a solidly filled magnetic material formed in each insulating layer. A coated magnetic head 30, which will be described later, is proposed.

FIGS. 4(A) to 4(C) show another conventional thin film magnetic head 3.
FIG. 4 is a schematic plan view showing recording medium sliding surfaces of Nos. 0 and 40;

In the figure, the same components as those of the conventional thin film magnetic head 10 are given the same reference numerals, and their explanations will be omitted.

This thin film magnetic head 30 has three flat insulating layers, namely, a lower insulating layer 32a, an intermediate insulating layer 32b,
Upper insulating layers 32c are stacked, and these insulating layers 32a
, 32b, 32c are connected to each other to form a magnetic circuit. Also, on the recording medium sliding surface 15, the magnetic layers formed on the lower core 12 are connected to each other through a magnetic gap 16. A front intermediate core 31 is disposed, and an upper core 13 is further disposed on the front intermediate core 31.

In such a thin-film head 30, the actual track width Tr is determined by the direction perpendicular to the sliding direction of the recording medium (that is, parallel to the magnetic gag surface) of the two magnetic layers joined via the magnetic gap 16 surface. direction). Therefore, if the upper core 13, front intermediate core 31, and lower core 12 had the same width and were reliably arranged, the required track width t and the actual track width Tr would match.

((A) in the same figure) However, in reality, each core is bonded using an exposure machine, etc., so positional deviation occurs, and the actual track width Tr becomes narrower than the required track width t. There were many. ((B) in the same figure) Therefore, another thin film magnetic head 40 is used in which the width of the front intermediate core 31 is set to the required track width t, and the width of the lower core 12 is formed larger than that of the front intermediate core 31. was. (Same figure (
C)) However, in magnetic recording technology, in order to increase the recording density, it is necessary to reduce the required track width t, and in the thin film magnetic head 40 as described above, the width of the front intermediate core 31 is reduced. had to be made narrower, and therefore the bottom area of the groove also had to be made smaller.

However, in such a thin film magnetic head 40, each core 12, 31, 13 has each insulating layer 32a, 32b, 32c.
Since the magnetic layer is buried in a groove formed in the magnetic layer, as the depth of the groove increases relative to the bottom area of the groove, voids (cavities) are more likely to be formed in the magnetic layer.
The problem is that the magnetic resistance increases.

Further, the following problem also occurred regarding the relationship between the widths of the upper core 13 and the front intermediate core 31.

That is, if the width of the upper core 13 is made equal to or narrower than the width of the front intermediate core 31, magnetic saturation is likely to occur;
Conversely, when the width of the upper core 13 is made wider than the width of the front intermediate core 31, a pseudo As a result of the gap being formed, crosstalk characteristics deteriorate.

(Problems to be Solved by the Invention) As described above, the conventional thin film magnetic head has the following problems.

■If the width of multiple cores is set to the required track width, it becomes difficult to obtain an accurate track width.

■If only the width of the front intermediate core 31 is set to the required track width and the width of the lower core 12 is set larger than this, (1) As the required track width becomes smaller, the magnetic layer of the intermediate core Voids are likely to occur inside, increasing magnetic resistance and deteriorating magnetic properties.

(2) Due to the size relationship between the widths of the upper core 13 and the front intermediate core 31, there are problems such as magnetic saturation and the formation of a pseudo gap.

(Means for Solving the Problems) The present invention has been made to solve the above problems, and includes a magnetic circuit consisting of at least a lower core, an upper core, and a front and rear intermediate core connecting these. , a thin film magnetic head in which a track is formed via a magnetic gap at either the connection between the front intermediate core and the upper core or the connection between the front intermediate core and the lower core, the lower core;
Each core of the upper core and both intermediate cores is made of a magnetic material filled in a groove formed in each insulating layer, and the surface of each insulating layer including the connecting surface of each core is flat, and the recording medium The width of the front intermediate core in a direction parallel to the magnetic gap on the sliding surface is set larger than the width of the lower core or the upper core in the said direction, and the width of the track is defined by the width of the lower core or the upper core. An object of the present invention is to provide a thin film magnetic head characterized by the following.

(Example) [Example 1] Figures 1 (A) and (B) show a thin film magnetic head 5 according to the present invention.
0, in which (A) is a schematic plan view showing a recording medium sliding surface, and (B) is a schematic cross-sectional view taken along the line S-8 in (A).

Hereinafter, the thin film magnetic head 50 of the present invention will be explained using the same figure, but the same components as those of the conventional thin film magnetic heads 30 and 40 will be given the same reference numerals and the explanation will be omitted.

The thin film magnetic head 50 according to the present invention, like the conventional thin film magnetic head 30, 40, has three flat insulating layers, that is, a lower insulating layer 32a, an intermediate insulating layer 32b, and an upper insulating layer 32c stacked together. Insulating layers 32a, 32b,
Magnetic layers formed at predetermined locations within 32c are connected to form a magnetic circuit.

As shown in the figure, the thin film magnetic head 50 according to the present invention is different from the thin film magnetic head 30 or 40 in that the width of the front intermediate core 31 is smaller than the width of the lower core 31. The track width is defined by the width of the lower core 12.

As described above, by forming the width of the front intermediate core 31 to be sufficiently larger than the required track width t, the width of the lower core 12 can be made to match the actual track width Tr, and the width of the front intermediate core 31 can be made to match the actual track width Tr. No voids are formed within the core 31.

Although the width of the upper core 13 is smaller than the width of the front intermediate core 31 in FIG. Of course, it is effective.

Note that even if the width of the lower core 12 is set to the required track width t, the length 4 of the lower core 12 in the direction perpendicular to the recording medium sliding surface is larger than that of the front intermediate core 31. The bottom area of the groove can be made sufficiently large relative to the edge depth, and voids are not formed in the magnetic layer of the lower core 12.

Further, regarding the relationship between the upper core 13 or the lower core 12 and the front intermediate core 31, the width of the front intermediate core 31 is set larger than that of the upper core 13 or the lower core 12, and the upper core 13
Alternatively, since the track width is defined by the width of the lower core 12, the upper core 13 and the lower core 12 are cut off by the intermediate core 31, and a pseudo gap is formed between the insulating layer portions of the lower core 12 and the upper core 13. It never happens.

[Example 2] FIGS. 2(A) and 2(B) are diagrams showing another thin film magnetic head 60 according to the present invention, and FIG. 2(A) is a schematic plan view showing a recording medium sliding surface, and FIG. Figure (B) is a schematic sectional view taken along the line T--T in Figure (A).

The thin film magnetic head 60 of this embodiment differs from the thin film magnetic head 50 described above in that in this embodiment, a magnetic gap 16 is formed between the upper core 13 and the front intermediate core 31, and the track width t is defined by the width of the upper core 13, and the width of the front intermediate core 31 is larger than the width of the upper core 13.

In the figure, by making the width of the lower core 12 sufficiently larger than the width of the front intermediate core 31, each core 12.31
．． To obtain a thin film magnetic head in which voids are not formed in the core 13 and each core 12, 31, 13 is formed in a stepwise manner, so that a pseudo gap is not formed and crosstalk characteristics are not deteriorated. be able to.

In this case, although the width of the lower core 12 is larger than the width of the front intermediate core 31 in the figure, the same applies to the case where the width of the lower core 12 is smaller than the width of the front intermediate core 31. Of course, similar effects can be obtained.

(Effects of the Invention) As described above, according to the present invention, the magnetic circuit has at least
Consisting of a lower core, an upper core, and a front and rear intermediate core that connect these, there is a magnetic gap at either the connection between the front intermediate core and the upper core or the connection between the front intermediate core and the lower core. A thin film magnetic head in which a track is formed through a thin film magnetic head, wherein each core of the lower core, upper core, and both intermediate cores is made of a magnetic material filled in a ridge formed in each insulating layer; The surface of each insulating layer including the connecting surface of each core is flat, and the width of the front intermediate core in a direction parallel to the magnetic gear on the recording medium sliding surface is the width of the lower core or upper core in the said direction. The width of the track is defined by the width of the lower core or the upper core, so the track width is accurate and no voids are formed in the magnetic layer, so the magnetic resistance is reduced. There are few, and
It is possible to provide a thin film magnetic head with good performance without causing magnetic saturation or pseudo gaps due to the positional relationship between the upper core and the front intermediate core.

[Brief explanation of drawings]

FIGS. 1(A) and 1(B) are diagrams showing a thin film magnetic head according to the present invention, in which FIG. 1(A) is a schematic plan view showing a recording medium sliding surface, and FIG. 2 (A) to (B) are schematic cross-sectional views taken along the S-8 cutting line of A>, and FIGS.
FIG. 3A is a schematic plan view showing a recording medium sliding surface, FIG. Figures 3 (A) and 3 (B) are diagrams showing a conventional thin film magnetic head. Figure 3 (A) is a schematic plan view showing a recording medium sliding surface, and Figure 3 (B) is a schematic plan view of Figure 3 (A). A schematic sectional view taken along the cutting line A-A, and FIGS. 4(A) to 4(C) are schematic plan views showing the recording medium sliding surface of another conventional thin film magnetic head. 50.60 Thin film magnetic head according to the present invention, 11.
... Substrate, 12 ... Lower core, 13 ... Upper core, 15 ... Recording medium sliding surface, 16 ... Magnetic gap, 19 ... Coil pattern, 31 ... Front intermediate core , 32a... Lower insulating layer, 32b... Intermediate insulating layer, 32c... Upper insulating layer, 4... Length, t... Necessary track width, Tr... Actual track width. patent

Claims (1)

[Claims] A magnetic circuit consists of at least a lower core, an upper core, and a front and rear intermediate core connecting these, and a connecting portion between the front intermediate core and the upper core, or a connecting portion between the front intermediate core and the upper core. A thin film magnetic head in which a track is formed through a magnetic gap at one of the connection parts of the lower core, wherein each core of the lower core, the upper core, and both intermediate cores is formed on each insulating layer. Each insulating layer is made of a magnetic material filled in a groove, and the surface of each insulating layer including the connecting surface of each core is flat, and
The width of the front intermediate core in a direction parallel to the magnetic gap on the recording medium sliding surface is set larger than the width of the lower core or upper core in the said direction, and the width of the track is determined by the width of the lower core or upper core. A thin film magnetic head characterized by: