JPH01133211A - Thin film magnetic head and its manufacturing method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thin film magnetic head, and in particular to a thin film magnetic head suitable for reducing signal interference (crosstalk) from adjacent tracks and obtaining a high S/N. The present invention relates to a thin film magnetic head having a magnetic head sliding surface shape.

[Conventional technology]

2. Description of the Related Art In recent years, thin film magnetic heads compatible with video tape recorders (VTRs) have been developed in order to cope with the increasing density and quality of video tape recorders (VTRs).

One of the advantages of thin-film magnetic heads over conventional bulk-type heads (mainly winding coils by hand) is that because a thin-film magnetic core is used, the core volume is smaller than that of conventional bulk heads. Since it can be made significantly smaller, it is resistant to external electromagnetic noise, etc., and because there is less leakage of magnetic flux due to the core shape, the head reproduction output per unit inductance may be increased. In addition, conventional bulk-type heads generally use a glass bonding process to form gaps, whereas thin-film magnetic heads form gaps by laminating thin films. A gap bonding process is no longer necessary, and the gap length can be regulated by controlling the thickness of the thin film, resulting in higher precision.

Conventionally, recording on a track other than a predetermined track (off-track recording) and reproducing a signal on a track other than a predetermined track (off-track reproduction) of a so-called thin-film magnetic head have been described by IE and Transaction On. Magnetics, MnG 20.5 (1984)
Pages 909 to 911 (I E E E, Tra
ns, On Magnetic s.

MAG-20No, 5 (1984), P, 909-9
11).

According to this, thin-film magnetic heads have a thinner core thickness on the sliding surface than conventional bulk heads, so leakage of magnetic flux to off-track and intake of magnetic flux from off-track are both small. Both off-track recording and off-track playback were considered to be small.

Also, as a similar prior art, Japanese Patent Application Laid-Open No. 61-289516
There is a thin film magnetic head described in No. 1, Technical Report MR84-12 (1984) of the Institute of Electronics and Communication Engineers, pages 55 to 60.

[Problem to be solved by the invention]

The above IEEE, Trans, ,○n Magn
etics.

MAG 20 No. 5 (1984) P2O3
The prior art described in JP-A No. 61-289516 is a head for a computer disk that performs recording and reproduction without contact with a magnetic recording medium, and this head is used for a VTR.
When applied to a system that slides directly with a magnetic recording medium, such as the above, there is a problem that the gap depth cannot be made large because the magnetic core is thin, and the life of the head is shortened due to wear.

In order to increase the gap depth, it is possible to increase the thickness of the magnetic core in order to prevent magnetic saturation of the magnetic core, and to configure the magnetic core so that a magnetic flux throttling effect can be obtained in the magnetic gap. , the above-mentioned prior art does not take this point into consideration.

Also, Institute of Electronics and Communication Engineers Technical Report MR84-12 (1984)
In the conventional technology described in , the lower core uses a magnetic thin film and magnetic ferrite, the upper core uses a magnetic thin film and magnetic ferrite, and the upper core uses a magnetic thin film, and is composed of relatively thick lower and upper cores. . However, since the lower core has a parallel surface that is larger than the track width (Tw) at the gap part, there is a phenomenon in which signals are recorded and reproduced wider than the track width (Tw) due to the influence of the core end. (hereinafter referred to as the fringe effect), the S of the signal
This is a point that causes a decrease in the /N ratio. In particular, when used in a VTR or the like, this phenomenon is likely to occur with reduced color signals, and appears as color flicker during playback. The above-mentioned prior art does not take into consideration signal interference (crosstalk) from adjacent tracks due to such fringe effects.

As mentioned above, in the conventional technology, especially when used in a VTR etc., there are problems such as prolonging head wear life, increasing gap depth) and signal interference from adjacent tracks (crosstalk).
We have not been able to present a configuration that satisfies both of these requirements at the same time.

SUMMARY OF THE INVENTION An object of the present invention is to provide a thin film magnetic head that has a sufficiently long service life against wear, reduces signal interference (crosstalk) from adjacent tracks, and provides a high S/N ratio.

[Means to solve the problem]

The above purpose is to change the shape of the sliding surfaces of the lower core and upper core of the thin film magnetic head so that the deviation amount of the core width (ΔTw1.ΔTw, ) on the gap surface of the core is 10 minutes of the track width (Tw). 1 or less, and the angles θ and θ2 between the gap surfaces and both end faces of the head sliding surfaces of the upper and lower cores in the vicinity of the gap surface are each 40 m (θ□<140' and 40"<02 90
This is achieved by ゜.

[Effect]

By configuring the sliding surfaces of the upper and lower cores so that the core width increases as the distance from the gap surface increases, at least in the vicinity of the gap, the magnetic core can be configured to restrict the magnetic flux at the magnetic gap. Even when the depth is relatively large, there is no magnetic saturation and good recording and reproducing characteristics can be obtained.

In addition, the amount of track deviation on the sliding surfaces of the upper and lower cores should be 1/1O or less of the track width, and the angles θ1 and θ2 formed by the gap surfaces of the upper core side surface and the lower core side surface should be 40'< 01, respectively. <t4o°and 4
By setting 0°≦02≦90°, it is possible to increase the magnetic resistance between the upper core and the lower core in the track deviation part other than the desired track width, reduce the fringe effect in the track deviation part, and make it possible to reduce the magnetic resistance from the adjacent track. Good head characteristics with less signal interference can be obtained.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a front view of a sliding surface showing a first embodiment of a thin film magnetic head according to the present invention, in which 1 is a lower core, 2 is an upper core, 3 is a gap material, 4 is a nonmagnetic substrate, 6a, 6b is an insulating material, 7 is a protective film, and 8 is a protective plate.

FIG. 2 is a sectional view of the main parts of the thin film magnetic head shown in FIG. 1, and the same reference numerals as in FIG. 1 correspond to the same parts.
5 is a signal coil.

In FIGS. 1 and 2, the structure of the thin-film magnetic head is that a lower core 1 is a magnetic film formed on a non-magnetic substrate 4 such as glass or ceramics, and a gap material 3 and a signal coil are formed on the lower core 1. 5 and insulating materials 6a and 6b, this magnetic film is used as an upper magnetic core 2 (hereinafter referred to as upper core), and a magnetic circuit is formed by these magnetic films.

The magnetic films forming the lower core 1 and upper core 2 are made of Sendust,
Permalloy, amorphous alloy, etc. are used. In this example, CO
A Co--Nb--Zr amorphous alloy based on was used to form a film with a thickness of approximately 20 μm by sputtering.

The gap material 3 is SiO□, 1I20. A non-magnetic insulating material such as Cr, Zr, etc. or a non-magnetic conductor such as Cr or Zr can be used. In this example, 5in2 is made by sputtering.
．． It was formed to have a thickness of 3 μm. The signal coil 5 is made of Cu, and is surrounded by an insulating material 6 such as 5i02.

Moreover, the sliding surface core shape parameters in FIG. 1 are set as follows.

The width of the part of the upper core and the lower core that face each other only through the gap material (regular gap part) is Tw, the angle between the upper core side surface and the gap surface is O, and the angle between the lower core side surface and the gap surface is O. 02. Let the amount of track deviation in the gap plane between the upper core 2 and the lower core 1 be ΔTw and ΔTν2.

FIG. 3 shows the amount of track deviation ΔTν (ΔTw□, ΔTw2) and the core end face angle θ0. of the thin film magnetic head configured as described above. 7 is a graph showing experimental results of dependence on crosstalk from adjacent tracks due to θ2.

From the same figure, the core end face angle θ1. As θ2 becomes smaller and as the amount of track deviation ΔTw becomes larger, crosstalk increases. The smaller the track deviation amount ΔTν, the less crosstalk occurs, but in order to reduce ΔT11, a highly accurate etching technique for the insulating material 6b shown in FIG. 1 is required.

Further, allowing 67w within a certain width has the advantage of improving manufacturing process yield.

This is because, in FIG. 3, as the value of ΔTw/Tw exceeds 0.1, the crosstalk increases rapidly.

The track deviation amount ΔTw is 0. It must be less than ITw. At this time, the track width Tν is 15 μm to 60 μm.
It was set as m. Also, within this range of 67W, the allowable value of crosstalk from adjacent tracks on a VTR is -30W.
In order to keep it below dB, the core end face angle θ and θ2
must be 40 degrees or higher.

FIG. 4 is a front view of the sliding surface of a thin film magnetic head showing a second embodiment of the present invention.

The figure shows an example in which the core width of the lower core 1 on the gap surface is larger than the core width of the upper core 2 on the gap surface, but even in such a case.

Track deviation amount ΔTw8. ΔTw2 and core end face angle θ1
The dependence relationship between °θ2 and crosstalk shows the same tendency as in the first embodiment.

FIG. 5 is a front view of the sliding surface of a thin film magnetic head showing a third embodiment of the present invention.

The figure shows an example in which the gap plane of the upper core 2 and the gap plane of the lower core 1 are shifted left and right, but even in such a case, the track shift amount is 67w, ΔTw, and the core end face angle θ.
1. The dependence relationship between θ2 and crosstalk shows the same tendency as in the first example.

FIG. 6 is a front view of the sliding surface of a thin film magnetic head showing a fourth embodiment of the present invention. Components and the like are given the same reference numerals as in the previous embodiment. The feature of this embodiment is that the angle θ2 between the side end face of the gap portion of the lower core and the gap face is approximately 90 degrees.

Crosstalk from adjacent tracks can be further reduced compared to the embodiments described above. FIG. 7 shows the upper core 2 and lower core 1 of the fourth embodiment shown in FIG.
This is an example in which a multilayer structure is formed using a. Figure 8 shows
FIG. 7 is an explanatory diagram of the manufacturing method of the fourth embodiment shown in FIG. 6;

The manufacturing method will be described below with reference to FIG.

In (a), a groove 1 for embedding the lower core in the non-magnetic substrate 4 is shown.
1 is formed by a method such as machining or etching. Next, in (b), after forming a magnetic thin film of 20 to 30 μm of amorphous, sendust, etc. as the lower core 1, it is flattened by a technique such as flattening lapping. In (c), the lower core 1 and the nonmagnetic substrate 4 are etched using a method such as dry etching under predetermined etching conditions in order to regulate the track width. In (d).

After forming the insulating material 6a for embedding to a thickness of 10 to 20 μm, it is flattened by a flattening wrap or the like to obtain a desired track width Tw. During this flattening wrap, θ2 is approximately 90
By forming the track width in a straight line, a highly accurate track width can be achieved without changing the track width Tw due to an error in the flattening wrap amount. In (e), after forming the thin film coil 5 (not shown), an insulating layer 6b is formed,
A through hole 12 is formed in the gap by etching or the like.

In (f), after forming the upper core 2 to a thickness of about 20 μm, a mask material 13 such as a resist is formed. Furthermore, if ion etching or the like is performed from above in (f), the roundness of the upper end surface of the mask material 13 is transferred to the upper core 2 as shown in (g). Furthermore, by forming a protective film 7 on this, a fourth embodiment of the present invention shown in FIG. 6 can be obtained.

In the embodiment shown above, the upper and lower cores are 20μ
By forming the film into a substantially fan-like shape with a film thickness of more than m, it is possible to obtain the effect of magnetic flux throttling in the magnetic gap, and even when the gap depth is about 15 μm, there is no magnetic saturation and good recording and reproducing characteristics are obtained, which is better than the conventional technology. Gap depth (5 μm
) can be achieved without increasing crosstalk.

Further, the arcuate shape of the end face opposite to the gap face 3 of the upper core and the lower core, and the interlayer insulating film 9a shown in FIG.
, 9b, and 10a are intended to prevent the contour effect that occurs when the core is parallel to the gap surface 3 (the end face of the core becomes a pseudo magnetic gap, reproduces a pseudo signal, and causes S/N deterioration). be.

Next, the above-mentioned track deviation amounts ΔTw□, ΔTν2 are Δ
An embodiment will be described in which TV1=ΔTw2=O and crosstalk from adjacent tracks can be further reduced.

FIG. 9 is a diagram showing the main part of a fifth embodiment of the thin-film magnetic head according to the present invention, in which (a) is a front view of the sliding surface, and (b) is a cross-sectional view of the vicinity of the gap. . 4 is a nonmagnetic substrate, 1 is a lower core, 6 is an insulating material, 3 is an operating gap, 2 is an upper core, 6 is a signal coil, and 7 is a protective film.

In the figure, the head structure consists of a lower core 1 embedded in a non-magnetic substrate 4 and an upper core 2 formed through an operating gap 3.

A signal coil 5 and an insulating material 6 provided around the signal coil 5 are provided between the lower cores. A protective film 7 is formed on the upper core 2 in order to stabilize sliding movement with the magnetic tape.

The shape of the head sliding surface is as shown in the same figure (,).

The upper and lower cores near the working gap 3 are approximately perpendicular to the working gap. The taper angle is α for the lower core.
2. The upper core is α□, and the length of the lower core is Δd1. The upper core is Δd1.

This shape is shown in the same figure (b). The shape is similar at the position where the gear depth is zero. Note that Tw indicates the track width.

The non-magnetic substrate 1 is a ceramic substrate made of Mn○ and NiO, but this alumina (Auzo3)-
A ceramic substrate such as zirconia (ZrOz) or a glass substrate such as crystallized glass can be used. The groove for embedding the lower core is formed by ion etching using a photolithography process, but it can also be formed by machining using a dicing saw.

The soft magnetic films for the upper and lower cores are made of a co-based amorphous alloy, but sendust, permalloy, or other amorphous alloy films may also be used. The operating gap 3 between the upper and lower cores is defined by the thickness of the Sin film used as the gap spacer material.

The signal coil 5 between the upper and lower cores is made of Cr/Cu/C
It has a three-layer structure of R, and its periphery is covered with an insulating layer of SiO□. In addition, instead of SiO□, forsterite (2MgO,
5in2) can also be used.

Figure 10 shows the track width (Tti) and the length d of the vertical part of the core.
It is a graph diagram showing the relationship between the ratio of (=Δd1+ΔdX) and performance, and the performance indicates the self-recording and reproducing ability in OdB when d is zero. In the region where the length d of the vertical portion is small, there is almost no deterioration in performance, but when d becomes large, problems arise such as saturation during recording and a decrease in reproduction efficiency due to increased magnetic resistance, resulting in deterioration of performance. 0≦d≦1/3
The performance deterioration in the Tw region is 0.5 dB or less, which poses no practical problem. Furthermore, 1/3Tw≦d≦1/2Tw
Even if the track width Tw
It is preferable to use this area when a process margin such as accuracy is required.

FIG. 11 is a schematic diagram of the operating gap portion.

The same symbols as in FIG. 1 correspond to the same parts.

In the figure, the taper angle α is the upper core 2. lower core 1
The edge of is straight. (α2=20″), and if the track width accuracy is ±10% or less of the track width, if there is an operating gap within the distance d, the dimension between the upper core side edges of the vertical part is Tν□ , If the dimension between the ends of the lower core side is 1w2, then Tw, ≦Tw≦Tw, and if the difference between Tw and Tν2 is 67w, 67w = 1
w2− Twl =2·dtanα. Since this is less than ±10% of the track width, ΔT11≦0.2Tw 2・dtancz≦0.2Tw Also, the maximum value of d is 2・−Tw− from the above 1/3Tw.
tancz≦0.2Twtanα≦0.3 Therefore, α is 17°.

Note that, in practice, α≦20a is sufficient because the gap position does not deviate much.

The dimensions of the above embodiment include a track width (Tw) of 30 μm.
m, Δd1 is 2 μm, and Δd2 is 4 μm.

Further, α,=20″, α2=20″.

According to this embodiment, the shape of the sliding surfaces at the ends of the upper and lower cores with the gap in between is substantially straight, so that a head can be obtained that has only the track width and no adjacent interference due to the fringe effect. Further, by limiting the above-mentioned portion to only the vicinity of the gap, a thin film magnetic head with excellent performance can be obtained without deterioration of recording performance due to core saturation in the middle.

FIG. 12 is a diagram showing the main part of a sixth embodiment of the thin-film magnetic head according to the present invention, in which (a) is a front view of the sliding surface, and (b) is a cross-sectional view of the vicinity of the gap. The same reference numerals as in FIG. 1 correspond to the same parts, 2a is the first upper core, 2b and 2c are the second upper cores, and 14 is the joint surface of the upper core.

The head structure according to this embodiment is composed of a lower core 1 embedded in a non-magnetic substrate 4 and an upper core 2 formed through an operating gap 3. A signal coil 5 and its signal coil are disposed between the upper and lower cores. It consists of an insulating material 6 provided around the periphery.

The upper and lower cores are core materials 1a, lb, lc, 2a+2b,
2c, 2d and insulating layers 9a, 9b, 10a.

It is composed of multiple layers consisting of 10b. Especially the upper core 2,
It consists of a first upper core 2a forming a gap surface, second upper cores 2b, 2c, 2d forming a magnetic path, and a joining surface 14 of these two cores. Insulating layers 9a, 9b,
10a and 10b are non-magnetic insulators such as Sin, ZrO, etc. By forming the core material into a thin multilayer structure, eddy current loss is reduced and high frequency characteristics are improved. Joint surface 14
is not an insulating layer and no insulating material is formed.

The abutment plane 14 is non-parallel to the working gap plane.

Further, the insulating layers 9a and 9b have a shape almost similar to the shape of the groove for embedding the lower magnetic core, and the insulating layers 10a and 10b have the shape of the bonding surface 14.
and a core connection through hole, and both are non-parallel to the working gap surface.

This embodiment is the same as the embodiment shown in FIG. 9 in that there is no track deviation, highly accurate track width setting can be achieved, and performance deterioration can be suppressed.

In particular, the first upper core 2a and the second upper core 2b, 2c
, 2d is made non-parallel to the operating gap surface, even if the bonding surface 14 operates as a pseudo gap, its influence can be removed by the azimuth effect. At the same time, even if the upper core has a multilayer structure,
The interlayer insulating layer becomes non-parallel to the gap plane, and the influence of the interlayer material can be removed.

Next, a method for manufacturing a thin film magnetic head according to a fifth embodiment of the present invention will be described.

13(a) to 13(h) are process explanatory diagrams showing one embodiment of the method for manufacturing a thin film magnetic head according to the present invention, and FIG.
This corresponds to the production of the thin film magnetic head shown in the figure.

(1) Lower core forming step FIGS. 13(a) and 13(b) show the lower core forming step. The lower core is first made of a non-magnetic substrate 4 as shown in FIG.
Form a groove for embedding the lower core. The non-magnetic substrate 4 is M
It is a ceramic substrate mainly composed of n O and NiO, but AQ 203. A ceramic substrate made of ZrO2 or the like may be used, or a glass substrate may also be used.

The groove forming process uses both ion etching and machining using a dicing saw, but only one of them may be used.

FIG. 2B shows a step of forming and embedding the lower magnetic film 1 in the lower core embedding groove formed in step (a). The magnetic film uses a CO-based amorphous alloy. Magnetron sputtering is used to form this magnetic film, but other methods can also be used.
For example, RF sputtering, DC sputtering, etc. can be considered. Further, it is also possible to use Fe-based amorphous alloy, sendust alloy, permalloy, etc. for the magnetic film.

Of the magnetic film formed on the entire surface of the substrate including the groove, the film outside the groove is removed by polishing. In addition, since this polished surface is the working gap forming surface, it is necessary to mirror-finish the surface to a surface roughness of O, tS or more.

(2) Gap forming step FIGS. 13(C) and (d) are the gap forming step. A gap spacer material 3 is formed on the polished surface of the lower core 1, and a first upper core 2a is further formed. Same figure (d)
Then, the first upper core 2a, the gap material 3. The lower core 1 is processed at the same time.

Sun is used for the gear tube spacer material 3.

In addition, ZrO2, forsterite (2MgO, Si
Inorganic materials such as n, ) and non-magnetic metal materials such as Cr can be used.

(3) Signal coil and insulating material formation process Figure 13(e)
, (f) shows the signal coils 5a, 5b and the insulating material 6 around them.
This is the formation process. The coil is made of Cr as the adhesive layer and C as the main conductor.
It has a Cr/Cu/Cr structure consisting of u. Cr and Cu are formed by a vapor deposition method or a sputtering method. Furthermore, although Sin is used as the insulating material 6, other inorganic materials such as forsterite (2MgO, Sin) can be used. Formation of Sin, forsterite, etc. is performed by a sputtering method.

(4) Upper core forming process As shown in FIG. 13(g), a through hole of a predetermined size is formed in the layer of insulating material 6 around the coil until it reaches the first upper core 2a, and then A second upper core 2 is formed. The 2' upper core 2 is processed into a predetermined shape by ion etching or the like to form the sliding surface shape shown in FIG. 13 (h). The magnetic core material may be the same as the lower magnetic core 1 or a different material.

According to the embodiment described above, there are effects as shown below.

First, the first fish is above the working gap 3.

Since the lower core is processed at the same time, there is no misalignment of the upper and lower cores, and the influence of fringe effects is extremely small.

As the second fish, the amount of processing of the upper and lower cores is small, and the accuracy of the track width Tw can be improved. The amount of processing by ion etching is about 10 μm in total for the upper and lower cores, which is thin for a sliding type thin film head. Therefore, the processing accuracy can be improved to about ±1 μm.

As the third fish, it becomes clear that the gap depth Gd becomes zero.

In the fourth fish, the gap between the upper cores near zero gap depth Gd is larger than usual, and the amount of glue-cage magnetic flux in this area can be reduced, improving efficiency.

The fifth point is that since the through-hole in the layer of insulating material 6 connects the first upper core and the second upper core, even if over-etching is performed when forming the through-hole, there is no effect on the gap surface.

14(a) to 14(h) are process diagrams showing another embodiment of the method for manufacturing the thin film magnetic head of the sixth embodiment of the present invention, in which the thin film magnetic head shown in FIG. 12 is manufactured. corresponds to

Note that the general process is almost the same as the embodiment shown in Fig. 13, so
Only the feature points will be explained below.

(1) Lower core forming process Figures (a) and (b) show the forming process of the lower core 1. The lower core includes soft magnetic thin films 1a, lb, lc and a nonmagnetic insulating layer (
It has a laminated structure in which interlayer materials 9a and 9b are alternately stacked.

(2). Gap forming process Figures (c) and (d) show the gap forming process, in which the first
Similar to the embodiment of the manufacturing method shown in FIG. 3, the first upper core 2a and the lower core 1 are simultaneously formed by ion etching.

(3) Formation process of signal coil and insulating material After forming the insulating material and signal coil as explained in FIG.
The coil is flattened by an etch-back method using a mask material 13 such as resist. At this time, the sliding surface shape is curved on the insulating material 6a as shown in FIG. 14(f) in order to transfer the resist coating state shown in FIG. 14(e).

(4) Upper core forming process As shown in FIG.
After forming the second upper core 2a, the through hole 12 is formed so as to reach the first upper core 2a, and as shown in FIG.
The upper core 5b is formed. At this time, through hole 1
Since ion etching is used in the formation step 2, the insulating material 6a above the working gap 3, as shown in FIG.
Since 6b has a curved shape, when forming the through hole, the first upper core 2 is removed while the insulating materials 6a and 6b are removed.
Since a is etched into a curved shape, the insulating materials 6a, 6
The curved shape of b is transferred to the first upper core 2a as shown in FIG.

Next, the second upper cores 2b, 2 are placed on the first upper core 2a.
c, form 2d (h).

In this way, by making the upper part of the first upper core 2a curved, the joint parts 14 with the second upper cores 2b, 2c, and 2d are formed.
The influence of the pseudo gap caused by this can be reduced by the azimuth effect. In addition, the second upper core is formed by a normal multilayer film forming process.
That is, the magnetic film 2b.

Even if the insulating films 2c and 2d and the insulating films (interlayer materials) 10a and 10b are formed alternately, it is possible to manufacture a thin film magnetic head without problems such as pseudo gaps.

15(a) to 15(h) are process diagrams showing still another embodiment of the method for manufacturing the thin film magnetic head of the sixth embodiment according to the present invention, in which the insulation in the embodiment shown in FIG. 14 is shown. This is a manufacturing method in which the shape of the material 6 is changed, and the outline of the process is the first one.
This process is similar to the process shown in Figure 4.

Therefore, description of the same parts as in FIG. 14 will be omitted.

Further, in FIG. 15, the same symbols as in FIG. 14 correspond to the same parts.

In the figure, (a) to (d) show a non-magnetic substrate 4, a lower core 11 operating gap 3, a first upper core 2a, an insulating material 6
This is the process of forming a, and is the same as that shown in FIG.

In this example, as shown in FIG. 2(e), when edge-backing is carried out, the upper surface of the first upper core 2a is formed in a wavy shape, and as shown in FIG. By ion etching the insulating material 6b, a through hole 12 reaching the first upper core 2a is formed as shown in FIG. After that, as shown in the same figure (h), the second upper core 2b
, 2c.

2d is deposited and formed. Note that the second upper core 2b.

In the figure, 2c and 2d have a multilayer structure by alternately forming magnetic films and insulating films (interlayer materials) 10a and 10b.

As a result, the first upper core 2a and the second upper core 2
b and the multilayer magnetic films 2b, 2c, 2d.
The influence of the pseudo gap formed between the insulating films 10a and 10b is significantly reduced.

FIGS. 16(a) to 16(i) and 16(a)' to 16(i)' are process diagrams illustrating still another embodiment of the method for manufacturing a thin film magnetic head according to the sixth embodiment of the present invention. A manufacturing method using a bias sputtering method will now be described. In addition, (a
) to (i) are cross-sectional views, and (a)' to (i)' are longitudinal cross-sectional views thereof.

(1) Lower core forming step FIGS. 16(a) and 16(b) show the lower core forming step. As shown in FIG. 4A, a lower core embedding groove 11 having a lower core shape is formed in the nonmagnetic substrate 4. As shown in FIG. Soft magnetic films 1a and lb are formed to fill this groove.

1c and interlayer insulating layers (interlayer materials) 9a and 9b are alternately formed. Next, as shown in FIG. 6(b), unnecessary magnetic core material is removed by lapping or the like, and at the same time, this lapping surface is used as a gap surface.

The material of the non-magnetic substrate, the processing method, the method of forming the material of the soft magnetic film, etc. are the same as the manufacturing process described above. Furthermore, interlayer insulating materials (interlayer materials) 9a and 9b used to form the lower core into a multilayer structure were made of 5 in 2 sputtered films, and the thickness thereof was 0.1 μm. In addition, AQ 203. Z
A non-magnetic insulating material such as rO2 can be used as the interlayer insulating material. The formation method used was high frequency magnetron sputtering.

(2) Gap forming step As shown in FIG. 16(c), a gap spacer material 3, which will become an operating gap, is formed on the lap surface of the lower core embedded in the groove formed in the non-magnetic substrate.

A first upper core 2a is further formed thereon. Next, as shown in FIG. 4(d), the first upper core 2a and a portion of the lower core 1 are simultaneously processed. As shown in the figure, the processed shape is such that the upper part including the working gap 3 has a taper angle of approximately 90', and the lower part has a gentle taper with a σ taper angle of 60° or less.

This processing is performed using an ion etching method, and the gap portion is processed to have the track width. The ion etching conditions are etching with an Ambon beam at an acceleration voltage of IKV and a current density of 1.4+A/a&, and the beam incidence angle is set to be 35@ inclined from the direction of normal incidence to the substrate surface.

(3) Formation of signal coil and insulating material As shown in FIG. 16(e), the first
A signal coil 5a is formed, and an insulating layer 6b is formed using a bias batter method as shown in FIG. The signal coil has a three-layer structure of Cr/Cu/Cr, with C
r is an adhesive layer. The insulating layer is made of Sin and is formed by RF magnetron sputtering. At this time, an RF bias is applied to the substrate. The bias level is about 10% of the sputter power, and in this example, the sputtering power was 800 W and the bias power was 30 W. According to bias sputtering, the insulating layer on the coil becomes almost flat, and the sliding surface also becomes flat depending on the conditions.

FIG. 16(g) shows a step of forming the second layer of coil 56 and insulating material 6c, and the top of the coil 56 is almost flattened.

The sliding surface shape was not sufficiently flattened, and a slightly convex shape remained.

(4) Upper core forming process FIG. 16(h) is a diagram showing the formation of the through hole 12 for connecting the core, and FIG.
, 2d after formation. The core connection through-hole 12 is formed in a shape obtained by transferring the convex shape remaining on the upper part of the insulating material 6c.

The upper core is made of magnetic films 2b, 2c, 2d and interlayer materials 10a, 1.
By forming a multilayer structure with 0b, the interlayer material 10a
, 10b are non-parallel to the gap, and the bonding surface 14 of the upper core is also non-parallel to eliminate the disturbing effect due to the pseudo gap.

According to this embodiment, the insulating layer on the first upper core can be formed into a convex shape by forming it by bias sputtering, and this convex shape can be transferred onto the first upper core 2a. The influence of the pseudo gap caused by the joint 14 between the core 2a and the second upper core 2b can be reduced by the azimuth effect. Further, when the second upper core is multi-layered, this also serves as a countermeasure against pseudo gaps. This makes it possible to manufacture a thin film magnetic head with less interference due to contour effects and the like.

In the embodiment with the above configuration, since there is no deviation between the track widths of the upper and lower cores, the influence of the fringe effect is eliminated, and adjacent interference during overlap recording can be eliminated. Also,
By arranging the portion where the core width is narrowed near the gap portion, it is possible to minimize core saturation during recording and to obtain a head whose characteristics do not deteriorate. Furthermore, since parts of the upper and lower cores are processed simultaneously, it is possible to manufacture a good thin film magnetic head with good track width accuracy and no reduction in S/N due to fringe effects or the like.

Next, a seventh embodiment will be described in which the amount of track deviation ΔTw between the upper core and the lower core on the head sliding surface can be reduced to zero in principle.

FIG. 17 is a front view of a sliding surface showing a seventh embodiment of the thin film magnetic head according to the present invention, and FIG. 18 is a line AA' in FIG. 17.
FIG.

In FIGS. 17 and 18, 1 is the lower core.

2 is an upper core, 3 is a gap material, and 4 is a nonmagnetic substrate.

7 is a protective film made of an insulating layer, 8 is a protective plate, 5 is a thin film coil, and 6 is an insulating layer. The shape of the head sliding surfaces of the upper core 2 and the lower core 1 is such that the upper end surface of the upper core 2 and the lower end surface of the lower core 1 are approximately arcuate, and are non-parallel to the gap surface 3, so that the contour effects can be prevented. Also.

The left and right end surfaces of the upper core 2 have a taper angle α3 and a taper angle α. The shape is connected to the end surface of the lower core 1 in a substantially straight line up to the B-B' plane of the lower core 1, and since there is no track deviation at the gap surface 3 between the upper core 2 and the lower core 1, crosstalk can be prevented.

A method of manufacturing the thin film magnetic head according to the seventh embodiment will be described below.

FIG. 19 is a process diagram illustrating a method for manufacturing the thin film magnetic head shown in FIG. 17, with (a) to (f) showing each process. In FIG. 4A, a lower core groove 11 is formed in the nonmagnetic substrate 4 by machining, etching, or other techniques. As the non-magnetic substrate 4, glass, ceramic, ferrite, etc. are used, and here a Mn-0, Ni-0 ceramic substrate is used. The depth of groove 9 is approximately 20 μm. Next, in (b), a Go-Nb-Zr amorphous alloy film having a thickness of about 25 μm is formed as the lower core 1 by sputtering, and is flattened by a technique such as lapping.

Next, although not shown in (c), the thin film coil 5 is
u, the insulating layer 6 is Sin, , A Q , 0. After patterning into a predetermined shape using et al., the gap material 3 and the upper core 2 are formed. As the gap material 3, Sin,
, A Il , 0. Or non-magnetic metal has a film thickness of 0.
The upper core 2 is made of the same material as the lower core and has a thickness of 20 μm. In (d), in order to make the upper end surface of the upper core approximately arcuate, a mask material 13 such as a resist is formed, and then the upper core 2. Gap material 3 and a part of lower core 1 are etched all at once from above upper core 2. In this example, an ion milling method using Ar gas was used as the dry etching method.

The shape of the mask material 13 is almost transferred to the upper core 2, resulting in a shape as shown in (e). During etching by this ion milling method, by varying the etching conditions (for example, the angle of incidence of the ion beam and the non-etched substrate, the shape of the mask material 13, etc.), the taper angle α3 of the core end face in (e) is changed. α. can be freely controlled. In the illustrated example, α3 is 45 to 90 degrees and α2 is 30 to 6
It was chosen to be in the 0 degree range. Through this process, as shown in (e), the upper core 2, gap material 3, and part of the lower core 1 are etched at the same time, resulting in a deviation (track deviation) in the gap surface 3 between the upper core 2 and the lower core 1. ) is completely eliminated, making it possible to sufficiently reduce crosstalk from adjacent tracks. Furthermore, in step (f), as the protective film 7, SiO□, AQ, Ol, 2
After an insulating layer of Mg0-5iO A thin film magnetic head according to the present invention shown in FIG. 18 is obtained. Further, in step (f), a glass material may be used as the protective film 7 in order to glass-bond the protective plate 8 after step (e).

FIG. 20 is a front view of the sliding surface of a thin film magnetic head showing an eighth embodiment of the present invention, which is substantially the same in structure and manufacturing method as the seventh embodiment shown in FIG. 17. The difference is that when etching the upper core 2, gap material 3, and lower core 1 all at once, the taper angle α3 was etched at a constant value.

The seventh and eighth embodiments have been described above, and the shape of the lower core groove 11 formed in the non-magnetic substrate 4 is such that the lower end is approximately arcuate, the taper angle of the side surface is 45 to 70 degrees, and the groove 11 is formed in the nonmagnetic substrate 4. The width is selected such that after the upper core 2, gap material 3, and lower core 1 are etched all at once, the maximum core width of the lower core is larger than the track width and smaller than the protrusion width on the etched bottom surface.

By doing so, the lower core 1 is prevented from expanding unnecessarily, and crosstalk is effectively reduced. Furthermore,
The non-magnetic substrate 4 includes an upper core 2, a gap material 3. When etching the lower core 1 all at once, the lower core material and It is desirable to select materials that exhibit approximately similar etch rates.

Further, in the above embodiment, in the plane B-B' shown in FIGS. 17 and 20, both core end surfaces of the lower core 1 have the maximum width, but the maximum width position of the left and right core end surfaces is , it is obvious that the effect of the present invention remains unchanged even if the plane is slightly deviated from the BB' plane.

〔Effect of the invention〕

As explained above, according to the present invention, the shape of the sliding surfaces of the lower core and the upper core of a thin film magnetic head and the amount of deviation of the core width on the gap surface between the two cores (ΔTw engineering, ΔTw2)
are each 1/10 or less of the track width (Tw), and the angles θ1 and 02 formed by the gap surface and both end surfaces of the head sliding surfaces of the upper core and lower core in the vicinity of the gap surface are 40°, respectively, and θ1 140a By making the cut 40" and θ2 90a, a magnetic flux throttling effect in the magnetic gap can be obtained, and the gap depth is more than 3 times that of the conventional one, and the crosstalk from adjacent tracks does not increase. A thin film magnetic head exhibiting recording and reproducing characteristics can be provided.

[Brief explanation of the drawing]

1 is a front view of a sliding surface showing a first embodiment of a thin film magnetic head according to the present invention, FIG. 2 is a cross-sectional view of the main part of FIG. 1, and FIG.
The figure is a graph showing the experimental results of the dependence of crosstalk from adjacent tracks on the amount of track deviation and core end face angle of the thin film magnetic head according to the present invention. Figure 4 shows the sliding of the thin film magnetic head showing the second embodiment of the present invention. 5 is a front view of the sliding surface of a thin film magnetic head showing a third embodiment of the present invention, and FIGS. 6 and 7 are front views of the sliding surface of a fourth embodiment of the present invention. , FIG. 8 is an explanatory diagram of the manufacturing process of the fourth embodiment, FIG. 9 is a diagram of the main part configuration of the fifth embodiment, and FIG. 10 is a diagram showing the ratio of track width to core vertical part length and performance. A graph diagram showing the relationship, Fig. 11 is a schematic diagram of the operating gap portion, Fig. 12
13, 14, 15, and 16 are explanatory diagrams of the manufacturing process of the sixth embodiment of the present invention. The figure is a front view of the sliding surface of a thin film magnetic head showing a seventh embodiment of the present invention, and the first
8 is a sectional view taken along the line A-A'' in FIG. 17, FIG. 19 is an explanatory diagram of the manufacturing process of the thin film magnetic head shown in FIG.
FIG. 0 is a front view of the sliding surface of a thin film magnetic head showing an eighth embodiment of the present invention. 1... Lower core, 2... Upper core, 3... Gap material. 4... Specific magnetic substrate, 5... Signal coil, 6... Insulating layer. Saki - Fist - Red 01,, ,. -henma (Sa ■ , Nn qsu 0 鴫弗) 4th country A 5th circle 6 Kuniaki 7th block 9th section m++ ``d''/r, v att Entaku / 2 Lu (fl) (A ) Origin/: 5I21 See/4fl Akira 16 Lugong/Etsu Tomoe (e) (e/”1st mouth ω (2 Cho Akira 77 Kuniman/8 concave

Claims (1)

[Claims] 1. On a non-magnetic substrate, at least a lower core, a gap material,
In a thin film magnetic head formed by laminating thin films of a coil and an upper core in a predetermined shape, the amount of deviation of the core width on the gap surface between the head sliding surfaces of both cores (ΔTw_1
, ΔTw_2) are each one-tenth or less of the track width (Tw), and the angles θ_1 and θ_2 formed by the gap surface and both end surfaces of the head sliding surfaces of the upper core and lower core near the gap surface are 40, respectively. °≦θ
A thin film magnetic head characterized in that _1≦140° and 40°≦θ_2≦90°. 2. The shape of the sliding surface of the upper core and the lower core is a substantially vertical straight line only in the vicinity of the gap, and the width of the core increases as the distance from the straight line increases, and the sliding surface of the upper core and the lower core 2. The thin film magnetic head according to claim 1, wherein an end surface of the core opposite to the gap surface is non-parallel to the gap surface. 3. The shape of the head sliding surfaces of the lower core and the upper core is made into a substantially vertical linear shape only in the vicinity of the gap, and the film of the lower core is formed from the upper end of the core on the opposite side to the gap surface on the head sliding surface of the upper core. 2. The thin film magnetic material according to claim 1, wherein the core width is widened as it reaches a predetermined distance within the thickness of the lower core in the thickness direction, and narrowed as it moves beyond the predetermined distance and reaches the lower end of the lower core. head. 4. The upper core is first formed on the gap surface.
a second upper core further formed on the first upper core and in contact with the first upper core to form a magnetic path; 4. A thin film magnetic head according to claim 1, wherein at least a bonding surface on a head sliding surface of the upper core is non-parallel to the gap surface. 5. The length of the lower core at a portion of the head sliding surface near the gap surface that is approximately perpendicular to the gap surface is Δ
d_2, the length of the upper core is Δd_1, and the track width is Tw, then Δd_1≠0, Δd_2≠0, and Δd_1+Δd_2≦Tw/3. A thin film magnetic head described in . 6. The lower core and the upper core have a multilayer structure consisting of a soft magnetic material and an interlayer insulating material, and the interlayer material forming surface of the second upper core is the joint surface of the first upper core and the second upper core. 5. The thin-film magnetic head according to claim 4, wherein the thin-film magnetic head has a shape that is approximately a transferred shape and is non-parallel to the gap surface. 7. A method for manufacturing a thin film magnetic head comprising laminating at least a lower core, a gap material, a coil, and an upper core thin film in a predetermined shape on a substrate, wherein at least a portion of the upper core, the gap material and 1. A method of manufacturing a thin-film magnetic head, comprising a step of etching a part of the lower core all at once using a dry etching method. 8. During the etching process, a mask material with a non-planar upper surface is used for etching all at once using a dry etching method, so that the shape of the upper surface of the mask material is changed to the upper end surface of the etched upper core. 8. The method of manufacturing a thin film magnetic head according to claim 7, wherein the upper end surface of the head sliding surface of the upper core is made to be misaligned with respect to the gap surface. 9. The method of manufacturing a thin film magnetic head according to claim 8, wherein the mask material having a non-planar upper surface is formed by bias sputtering. 10. The upper core formed on the non-parallel surface to form a magnetic path has a multilayer structure consisting of a soft magnetic material film and an interlayer material film, and the insulating film on the gap surface is formed on the non-parallel surface. 10. The method of manufacturing a thin film magnetic head according to claim 8, wherein the parallel plane shape is formed on the transferred surface.