JP3397159B2 - Magnetic head - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head used for magnetic recording and a method for manufacturing the same. Further, one aspect of the present invention relates to a recording / reproducing separated type magnetic head particularly suitable for recording / reproducing at high recording density.

[0002]

2. Description of the Related Art As a conventional magnetic head technology, for example, there is one disclosed in Japanese Patent Laid-Open No. 59-178609.

Further, conventionally, in order to increase the recording density of magnetic recording, there has been proposed a magnetic head in which only the head gap portion is projected in the medium direction. For example, Eye Triple E Transaction on Magnetics (IEEE TRA
NSACTION ON MAGNETICS,) vol.24, No6, November 1984
pp.2841-2843 describes a method of determining the track width of the magnetic head by processing it from the sliding surface side.

A magnetoresistive head (hereinafter referred to as an MR head) used as a read-only magnetic head.
Also in JP-A-59-71124 and JP-A-1.
Japanese Patent Publication No. 277313 discloses a structure in which only the track width portion (magnetic sensing portion) is projected to the medium facing surface.

On the other hand, as for the recording / reproducing separated type magnetic head in which the MR head and the induction type writing head are integrated, there is a known example such as JP-A-51-44917.

[0006]

However, in the head having the structure described in the above Eye Triple, the magnetic flux leaks from a region other than the track width defined by etching, so that there is a problem that the off-track characteristic is poor. Moreover, since a relatively wide area of the slider rail is removed by etching, the flying characteristics of the slider change significantly before and after processing. Further, if an etching method used in a normal semiconductor process is used, it is very difficult to uniformly apply the resist on the slider rail, which causes a problem in mass productivity.

Further, according to the techniques described in JP-A-59-71124 and JP-A-1-277313, when forming an MR head in which only the magnetic sensitive portion is projected, the magnetic shield layers sandwiching the MR element from both sides are formed. Since it is wider than the protruding width, the magnetic flux from the adjacent tracks interlinking via the shield layer becomes noise. Therefore, there is a problem that when the number of signals decreases as the track becomes narrower, the signal / noise becomes lower.

Further, when a composite type magnetic head is made up of an MR element having only a magnetic sensitive portion protruding and an inductive write head, the recording magnetic pole and the MR element protruding portion are displaced in width due to a positioning error. Therefore, there is a problem that the narrowing of the track makes the ratio of the deviation in the track width remarkable, and thus the reproduction efficiency is lowered.

That is, in the above-mentioned conventional MR head, in order to make the track narrower, only the track width portion is projected to the medium facing surface so that the signal is not detected in the portion other than the read track width. In this conventional head, an MR element pattern having a shape in which only the track width portion is projected is formed on the substrate, and the recording head or the like is formed in accordance with this projection. After that, the substrate is cut, and the cut surface is polished to form a head in which only the protruding portion is exposed to the medium facing surface. Therefore, the MR element protrusion width and the shield layer width do not necessarily coincide with each other, and the recording magnetic pole width does not coincide with the MR element protrusion width.

A first object of the present invention is to provide a narrow track magnetic head excellent in off-track characteristics and a method for manufacturing the same.

A second object of the present invention is to provide a magnetic head having an excellent signal / noise ratio.

A third object of the present invention is to provide a recording / reproducing separated type magnetic head which has no track position deviation between the recording head and the reproducing head and has an excellent signal / noise ratio.

A fourth object of the present invention is to provide a method of manufacturing a magnetic head for narrowing the track of the magnetic head without changing the flying characteristics of the slider.

A fifth object of the present invention is to provide a method for manufacturing a high recording density magnetic head having a narrow track width with high yield.

[0015]

The above first object is achieved by providing one or more grooves in a part of the sliding surface of the magnetic head with respect to the medium. More specifically, a local recess is provided near the magnetic gap of the magnetic head or the magnetic sensitive section,
These widths are specified. In a preferred embodiment of the present invention, these grooves or recesses are processed by a focused ion beam (referred to as FIB). In a preferred embodiment of the present invention, these grooves or recesses are filled with a substance.

The second object is achieved by forming the MR element and the shield layer on the substrate and then collectively processing the track width from the medium sliding surface side.

In order to prevent the track positions of the recording head and the reproducing head from being displaced, the third purpose is to form the recording head and the reproducing head on the substrate and then perform the track width processing by etching from the polished cut surface. It is achieved by doing. That is, only the track width portions of the soft magnetic films of the recording head and the reproducing head constituting the head are left on the air bearing surface, and the other portions are removed by etching so that the distance to the medium becomes large. At the same time, the shield layer of the reproducing head was also subjected to track width processing so that only the protruding portion was exposed on the air bearing surface. Further, in a preferred embodiment, in order to prevent the coil of the recording head and the flattening layer covering the coil from being exposed during processing from the air bearing surface, an etching stopper material was previously provided in this portion in the head laminating step.

The fourth object of the present invention is achieved by using a focused ion beam to process a part of the rail on the sliding surface of the head slider.

The fifth object of the present invention is achieved by processing the shape of a magnetic head using a beam having a focused energy without coating a resist on a slider rail.

By providing one or more grooves in a part of the sliding surface of the magnetic head with respect to the medium, the convergence does not leak from a region other than the track width defined by the grooves, and a narrow off-track characteristic is obtained. A magnetic head for a truck can be provided.

If a focused ion beam is used when forming a groove only on a part of the sliding surface, the processing yield and accuracy are improved.

By filling the groove with a substance, leakage of magnetic flux can be further reduced.

After the MR element and the shield layer are formed on the substrate, the width of the shield layer can be made approximately the same as the protruding width of the MR element by collectively processing the track width from the medium sliding surface side. Therefore, it is possible to provide a magnetic head having excellent signal / noise characteristics, without magnetic flux from adjacent tracks being mixed in via the shield layer to generate noise.

In the present invention, since the distance between the member and the magnetoresistive effect element including the magnetic shield layer, that is, the spacing is large except for the protruding portion which is the magnetic sensitive portion, the distance from the portion other than the magnetic sensitive portion is increased. Signal is significantly reduced.
For example, when the flying height is 0.15 μm and the receding amount is 2 μm, the signal from the adjacent track decreases by −50 dB or more with respect to the signal when the recording wavelength is 2 μm. By retracting the portions other than the magnetically sensitive portion in this manner, the noise caused by the adjacent tracks can be significantly reduced.

Further, the track widths of the recording head and the reproducing head are simultaneously processed at the same time, so that the track widths of both heads can be aligned with extremely high accuracy. Further, by using the stopper material for etching, the etching margin can be widened even when FIB is not used.

Focused ion beam etching (F
By using the IB) method to form the protrusion or to form a groove in a part of the slider rail of the head, a groove having a large aspect ratio can be formed in a minute region, and thus the slider is floated by processing. It does not affect the characteristics.

Further, if the shape of the magnetic head is processed by using the beam having the converged energy without applying the resist on the slider rail, the desired shape can be processed with a high yield. Further, since the conductive layer can be formed in the groove formed by processing, it is easy to fill the groove with a magnetic shield material by using the electric field plating method or the like, and the off-track characteristic A good head can be created.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Reference Example 1 In this reference example , the results of examination of the method for manufacturing a magnetic head according to the present invention and the effect on recording / reproducing characteristics will be described. FIG. 1 is a perspective view of a magnetic pole portion of an induction type thin film head after being processed by a focused ion beam etching method (hereinafter abbreviated as FIB) as observed from a sliding surface side. The material of the magnetic pole 102 is permalloy having a saturation magnetic flux density of 1.0 T, and the gap layer 104 and the protective layer 103 are alumina. The slider 101 material is zirconia. FIB
The track width of the magnetic head before being processed in (1) is 10 μm, and the pole thickness is 1.5 μm in the upper part and 1.0 μm in the lower part. Since zirconia, which is the slider material of the head used this time, is a non-conductive material, the sample is charged up during the FIB processing, and the film cannot be formed accurately. Therefore, before processing by FIB, an ultrathin layer of Au was formed on the slider surface by vapor deposition. The Au vapor-deposited layer was formed by normal ion milling after FIB processing,
Alternatively, it can be removed by polishing. Meanwhile, FIB
When using a system that irradiates an electron beam during processing to neutralize charge-up, vapor deposition is not necessary. In Fig. 1, the track width after FIB processing is 1 for both the upper and lower parts.
The sample has a μm and a working depth of 2.0 μm. The ion species of the ion beam 100 used for processing is GaIn, the acceleration voltage is set to 30 kV, and the beam current is set to 1.6 nA.
The beam diameter at this time is 0.2 μm.

Reference Example 2 The groove portion formed by FIB processing is filled with a non-magnetic metal material having a small specific resistance, for example, Cu, and the portion other than the track portion defined by the processing is utilized by utilizing the eddy current loss. The leaked magnetic flux can be reduced especially in the high frequency region. The method of manufacturing this sample is such that FIB processing is performed in a W (CO) ₆ atmosphere, a W layer is formed in a region irradiated with FIB, and electrolytic plating is performed using this conductive layer to form Cu. is there. In addition to this method, it can be realized by using Al or the like having high electric conductivity as an ion electrode and forming a Cu layer by electric field plating using an ion implantation layer formed in a groove portion of a sample by FIB processing. . Here, C, which is a magnetic shield layer, is formed in the groove portion after FIB processing.
A three-dimensional magnetic field measuring device using the Lorentz tendency of the electron beam is used to measure the difference in magnetic field distribution and magnetic field intensification between the thin film head in which the u layer is formed and the thin film head in which the groove is still dug. It was measured. FIG. 2 is a result of measuring the distribution of the longitudinal recording component Hx of the magnetic field distribution measured at 30 MHz in the track width direction at the center position of the gap. The track width of the head after processing is set to 1 μm in all the samples. From this result, it is understood that by forming Cu as the shield layer in the groove portion, the leakage magnetic flux leaking from the area other than the track can be significantly suppressed. The effect of this shield layer becomes more remarkable as the frequency becomes higher. The processing depth of the head used for the measurement this time was 2 μm, but the leakage magnetic field of the head in which the Cu layer was not formed hardly changed even if the processing depth was further increased. On the other hand, FIG. 3 shows the results of measuring the frequency dependence of the maximum value of Hx at the center position of the head magnetic pole, that is, the gap and the center position of the track. From this figure, it can be seen that the effect of the Cu shield layer increases with respect to the magnetic field strength as the frequency increases.

Reference Example 3 Here, the track widths of the upper magnetic pole and the lower magnetic pole do not match, for example, a self-recording / reproducing thin film head manufactured by the process of Japanese Patent Laid-Open No. 59-178609, and this head are FI.
FIG. 4 shows a result of comparison of off-track characteristics with a thin film head in which the track width of the upper magnetic pole and the track width of the lower magnetic pole are matched with each other with the accuracy of 0.1 μm by the B processing. FI
B The track width of the upper magnetic pole before processing is 10 μm and that of the lower magnetic pole is 13.5 μm.
It is 0 ± 0.05 μm. In this experiment, FI
A Cu layer is formed in the groove portion of the slider rail processed in B. Coercive force 1500 Oe, thin film 0.06 for measurement
Spacing is 0.1 μm using μm sputter medium
And The recording density 50kFCI (F lux C h
It was set to ange per I nch). From the results of FIG. 4, it can be seen that the effect of aligning the track ends of the upper and lower magnetic poles becomes remarkable when the off-track amount exceeds half the track width, and is effective when the track pitch is sandwiched. In this case, no change was observed in the reproduction output and overwrite characteristics before and after processing.

Example 1 Next, the change in reproduction output per unit track width was measured by narrowing the track width from 10 μm to 0.25 μm with the dimensional difference between the track widths of the upper and lower magnetic poles suppressed to 0.1 μm or less. did. The results are shown in FIG. The measurement conditions and the medium are the same as those used in FIG. Here, a self-recording / reproducing thin film head and a recording / reproducing separated head using an MR head for reproduction were used. The processing depth of the FIB was set to 2.0 μm for both heads. From the results shown in FIG. 5, in the self-recording / reproducing head, the reproduction output is attenuated when the track width is less than 3 μm, and when the track width is 1 μm, the reproduction output is reduced to half of the original reproduction output (the reproduction output of the head having the track width of 10 μm). It can be seen that it decays up to. As a result of observing the recording track recorded by the head of each track width with a Lorentz microscope, the medium is uniformly recorded in the track width direction corresponding to the head track width even if the head track width is 0.25 μm. Have been confirmed. Therefore, it is considered that the cause of the attenuation of the reproduction output due to the narrowing of the track width to 3 μm or less is mainly due to the deterioration of the reproduction sensitivity of the head. On the other hand, in the recording / reproducing separation head using the MR head for reproduction, no reduction in reproduction output was observed even if the track width was narrowed to 1 μm, and even if the track width was narrowed to 0.25 μm, the original output was 80%.
It turns out that it is getting more than the percentage. As described above, it was confirmed that a recording / reproducing head having a recording head and a reproducing head separated and integrated was effective for a head having a track width of 3 μm or less.

Reference Example 4 Next, FIG. 6 shows the results of examining changes in reproduction output and off-track characteristics of a magnetic head processed by changing the incident angle of FIB. The track width after FIB processing is 3 μm, and the processing depth is 2 μm. The medium used for measuring the recording / reproducing characteristics and the measuring conditions are the same as those in FIG. The horizontal axis of FIG. 6, that is, the incident angle θ of the ion beam is the deviation from the direction orthogonal to the head sliding surface, and when machining the right and left sides of the track, the incident directions are symmetrical with respect to the track center. It is set to be. The off-track performance index OF is used as an index for evaluating the off-track characteristics.
P was used. This PFP is defined as follows.

OPP = x / (Tw / 2) where X is the off-track amount when the reproduction output decreases from the initial value by 6 dB when the head is off-track,
Tw is the track width of the head after FIB processing. From this figure, it can be seen that the off-track characteristics deteriorate when the incident angle is 10 degrees or more, while the reproduction output decreases when the incidence angle is 0 degrees or less, and becomes unstable when the incidence angle exceeds 20 degrees. From this result, it is understood that it is desirable to set the incident angle of the beam to about 0 to 10 degrees. In this reference example , the head shape was set to an arbitrary shape by changing the incident angle of the FIB. However, even if the incident angle is 0 °, the irradiation amount is changed two-dimensionally and the polarization method is devised so that the track unit It is possible to process the head with an inclination.

Reference Example 5 Next, FIG. 7 shows the results of examining how much the recording / reproducing characteristics are changed by uniformly scraping off the portions other than the magnetic poles of the head slider rail after finishing the polishing. . In a normal thin film head sliding surface polishing step, a processing step of about 20 to 30 nm is formed between the slider rail and the magnetic pole magnetic film. This processing step was eliminated by cutting the slider rail. Since the surface property of the slider rail is hardly changed by the FIB processing, it has been confirmed that the flying characteristics of the slider are not changed before and after this processing. The medium and the measurement conditions used for measuring the recording / reproducing characteristics are the same as the above-mentioned conditions. As a result of this FIB processing, it was found that the reproduction output can be improved by about 16% at a recording density of 50 kFCI by uniformly cutting the region of the slider rail other than the magnetic pole portion by about 30 nm.

Reference Example 6 Finally, this FIB processing can be utilized to transform a normal thin film head for in-plane recording into a single-pole vertical head, so an example will be introduced. In this processing, only the upper magnetic pole of a normal thin film head for in-plane recording is shaved off to some extent. FIG. 8 shows the result of examining the perpendicular recording characteristics of the pseudo single pole type vertical head formed by this processing. The coil of the head used here is embedded in the alumina layer. The medium used for the measurement was a CoCr / permalloy bilayer film medium, and the spacing was 0.05 μm. Note that another vertical head is used for reproduction because of the magnetic pole thickness. From this result, it was confirmed that as the processing depth of the upper magnetic pole was increased, the recording mode was changed from the in-plane to the perpendicular to improve the recording density characteristic. Here, by optimizing the thicknesses of the upper magnetic pole and the lower magnetic pole respectively, a single magnetic pole head that can be used for both recording and reproduction can be manufactured using a photoresist mask of a normal in-plane recording thin film head. In this manner, the FIB processing can be used to convert the in-plane recording head to the vertical recording head.

Second Embodiment Another embodiment of the present invention will be described with reference to FIG. 9A is a perspective view of the recording / reproducing separated type head as seen from the air bearing surface side, and FIG. 9B is a sectional view taken along line AA ′.
As can be seen from the figure, in the head shown in this embodiment, a recording head 11 is provided behind the reproducing MR head 10.
The magnetic pole 12 on one side of this recording head also serves as one shield layer 2 of the MR head. The structure of the MR head is as described below. A magnetoresistive effect element 3 and an electrode 4 for passing a current are provided between the two soft magnetic members 1 and 2 which function as a magnetic shield layer. First, a permalloy pattern having a film thickness of 2 μm is formed as the first shield layer 1 on the alumina titanium carbide substrate 5 on which the insulating layers made of alumina are laminated. The shape was rectangular. Next, the MR element 3 is formed via the insulating layer. Alumina was used for the insulating layer. In this embodiment, the shunt bias method is used as a method of applying a bias magnetic field necessary for operating the MR element. Therefore, a titanium film having a thickness of 0.1 μm is continuously laminated as a shunt film on a permalloy film having a thickness of 40 nm, and then a rectangular MR element pattern is formed by photoetching. After that, a copper electrode 4 having a film thickness of 0.2 μm is formed on both sides except the portion to be the magnetic sensitive portion. Next, the second shield pattern 2 is formed via the insulating layer. This shield pattern also serves as the first recording magnetic pole 12. In order to obtain a large recording magnetic field, a Co type amorphous soft magnetic film having a saturation magnetic density larger than that of Permalloy was used. The film thickness was 2.5 μm. Alumina having a film thickness of 1 μm was used for the gap layer 13. The coil 14 was 5 turns made of copper with a film thickness of 3 μm. After that, as a stopper material for etching through the insulating layer 18, 0.2
A pattern 19 made of Ti and having a thickness of μm was provided on the slope portion of the flattening layer on the air bearing surface side. Then, similarly to the first magnetic pole, the film thickness 2
A second recording magnetic pole 15 is formed using a Co-based amorphous soft magnetic film of μm, and then a protective film is laminated. After that, the substrate is cut and the air bearing surface is polished.

In the middle of the polishing process, a part of the air bearing surface other than the portion to be the magnetic sensitive portion is removed by a photo etching technique which is usually used. First, a photoresist having a thickness of about 3 μm is applied to the air bearing surface, and then exposed to obtain a resist pattern having a desired shape. Using this as a mask, ion milling using Ar gas is performed to form the recesses 7 and 8, and the magnetic sensitive portion 9 is projected. The width of the protruding portion 9 of both the MR head portion and the recording head portion was 3 μm, and they were formed on the same track.

In the above process, in order to obtain a head with good reproduction efficiency, it is preferable to project only the MR element portion which is not short-circuited by the electrode. For this purpose, it is necessary to match the electrode pattern and the convex portion forming pattern with good brightness at the time of exposure, and it is preferable to provide a narrowing pattern on the electrode layer so that the matching marker is exposed on the air bearing surface. . Further, in order to have a matching margin, it is preferable that the width of the portion where the electrodes are not provided, that is, the electrode interval is wider than the protruding width. In this embodiment, the electrode interval is 4 μm and the width of the protrusion is 3 μm.

Although the photoresist is used as a mask for ion milling in the above embodiment, a metal mask or a carbon mask may be used by using a multi-layer resist method or a selective etching method.

FIG. 10 shows the sensitivity distribution in the track width direction of the head shown in this embodiment (solid line in the figure), which is the sensitivity distribution of the head having no protrusions in which the track width is defined by the electrode intervals at both ends of the conventional structure (broken line). ). It can be seen that the head of this embodiment has a steeper attenuation at the track edge and is less likely to be affected by adjacent tracks.

As described above, since the recording head and the reproducing head protrusion can be simultaneously formed with high precision by etching from the air bearing surface, the recording head and the reproducing head are not misaligned, and therefore, the reproducing can be efficiently performed.

Although the Co type amorphous material is used as the magnetic pole material in the above embodiment, other high saturation magnetic flux density materials such as Fe type crystalline material can be used. Further, in the figure, the width of the recording head in the track width direction before the formation of the concave portion matches the width of the shield layer of the M head, but it may be different if it is wider than the width of the protruding portion.

Embodiment 3 Another embodiment will be described with reference to FIG. This example is real
Similar to the second embodiment, the recording head is provided after the MR head. However, the width of the protrusion of the recording head is 4 μm,
The width of the protrusion of the MR head is 3 μm, and the width of the reproducing head is narrower. As known from the past,
When there is an error in the positioning of the head, reproducing a track width narrower than the recorded track width is less likely to be affected by noise from adjacent tracks. By etching from the air bearing surface as in the present embodiment, the track width can be easily changed by changing the protruding width of the reproducing head and the recording head. Therefore, it is possible to easily form a magnetic head having an appropriate recording and reproducing track width.

In each of the above embodiments, the shunt bias method is used as the bias magnetic field applying method for the MR head, but the present invention is not limited to this method.
The conventionally known permanent magnet bias method, soft film bias method, exchange coupling bias method using an antiferromagnetic film, and the like can also be used.

Fourth Embodiment Another embodiment will be described with reference to FIG. In this embodiment, the MR element 3 is provided between the magnetic poles 16 and 17 of the recording head, and the magnetic pole also serves as the shield film of the MR head.
In the figure, a Co type amorphous magnetic film having a high saturation magnetic flux density is used for the magnetic pole, and the film thickness is 2 μm. The bias magnetic field applied to the MR element was applied by applying a direct current to the recording coil. Therefore, the MR element does not have a shunt film, but is composed only of permalloy and electrodes. A bias magnetic field is more easily applied to the MR element if the MR element is displaced from the center position between the magnetic poles. In this embodiment, the ratio of the distance between the magnetic pole and the element is set to 1: 2. Other than the above, the structure of the head and the method of processing the protrusion of the air bearing surface are the same as those of the above-described embodiment.

According to this embodiment, since the MR element is located between the recording magnetic poles and the recording electrode also serves as the shield layer, the widths of the recording magnetic pole shield layer and the protrusion of the MR element are the same, and the recording track and the reproducing track are the same. It is possible to obtain a magnetic head having no displacement between the two.

[0047]

As described above, according to the present invention, it is possible to provide a magnetic head having a simple structure with improved noise characteristics due to adjacent tracks. Also, the recording head and the reproducing head can be aligned with high accuracy.

Further, even a head having a track width of 1 μm or less can be manufactured with a high yield, which is particularly effective as a head for a magnetic disk device which has a large storage capacity and requires high-speed data transfer.

[Brief description of drawings]

FIG. 1 is a perspective view of a magnetic pole portion of a head according to the present invention.

FIG. 2 is a graph showing a magnetic field distribution of the magnetic head of the present invention.

FIG. 3 is a graph showing the frequency dependence of Hx of the magnetic head of the present invention.

FIG. 4 is a graph showing a comparison between off-track characteristics of the magnetic head of the present invention and a conventional example.

FIG. 5 is a graph showing the relationship between the change in reproduction output of the magnetic head of the present invention and the track width.

FIG. 6 is a graph showing the relationship between the incident angle and the off-track characteristic of the FIB used in the manufacturing of the present invention.

FIG. 7 is a graph showing a change in recording / reproducing characteristics when a portion other than the magnetic poles of the slider rail is uniformly processed by FIB.

FIG. 8 is a graph showing recording characteristics of a vertical head obtained according to the present invention.

FIG. 9 is a perspective view of a magnetic head of the present invention in the vicinity of a gap.

FIG. 10 is a graph showing a sensitivity distribution in the track width direction of the MR head.

FIG. 11 is a perspective view of a recording / reproducing combined head according to another embodiment.

FIG. 12 is a perspective view of a recording / reproducing combined head according to another embodiment.

[Explanation of symbols]

1, 2 ... Magnetic shield layer, 3 ... Magnetoresistive element, 4 ...
Electrodes, 5 ... Slider base, 6 ... Protective film, 7, 8 ... Air bearing surface concave portion, 9 ... Air bearing surface convex portion (magnetic sensitive portion), 10 ... Read head, 11 ... Recording head, 12 ... Recording head magnetic pole (also shield) Layer), 13 ... Gap layer, 14 ... Coil, 15 ... Recording magnetic pole, 16, 17 ... Recording magnetic pole / shield layer, 18
... Insulating layer, 19 ... Ti pattern, 100 ... FIB

Front page continuation (72) Inventor Hidetoshi Moriwaki 1-280, Higashi Koikekubo, Kokubunji City, Tokyo Inside Central Research Laboratory, Hitachi, Ltd. (72) Inventor, Isamu Yubi 1-280, Higashi Koikekubo, Kokubunji, Tokyo Hitachi Research Center Co., Ltd. In-house (72) Inventor Kazuo Shiiki 1-280 Higashi-Kengokubo, Kokubunji-shi, Tokyo Inside Hitachi Central Research Laboratory (72) Inventor Takeshi Onishi 1-280 Higashi-Kengokubo, Kokubunji-shi, Tokyo Inside Hitachi Central Research Center (72) Inventor Toru Ishiya 1-280, Higashi Koigokubo, Kokubunji, Tokyo, Central Research Laboratory, Hitachi, Ltd. (72) Inventor Toshio Kobayashi 1-280, Higashi Koikeku, Kokubunji, Tokyo (72) Inventor, Central Research Laboratory (72) Hideo 1-280, Higashi Koigokubo, Kokubunji, Tokyo (56) References JP-A 64-82312 (JP, A) JP-A 57-44217 (JP, A) JP 52-14410 (JP, A) JP 59-16115 (JP, A) JP 58-164135 (JP, A) JP 60-126834 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G11B 5/31 G11B 5/39

Claims (5)

(57) [Claims] 1. A reproducing head having a magnetoresistive element and a recording head having magnetic poles provided above and below a gap layer, wherein a groove or a groove is formed on a surface of the reproducing head and the recording head facing a magnetic disk medium. A recess is formed, the groove or the recess is filled with a magnetic shield material, and the width of the upper magnetic pole and the lower magnetic pole of the recording head is defined by the groove or the recess filled with the magnetic shield material. A magnetic head characterized in that the track width of the reproducing head is defined by the filled groove or recess. 2. The magnetic head according to claim 1, wherein the magnetic shield material is a non-magnetic material. 3. The magnetic head according to claim 1, wherein the magnetic shield material is a conductive material. 4. The difference in width between the upper magnetic pole and the lower magnetic pole is 0.1.
The magnetic head according to claim 1, wherein the magnetic head has a thickness of not more than μm. 5. The magnetic head according to claim 1, wherein the groove or the recess is formed by a focused ion beam etching process.