JPH0793723A - Thin-film magneto-resistance effect type magnetic head - Google Patents

Abstract

PURPOSE:To provide the thin-film MR effect type magnetic head which is increased in recording density by decreasing the difference in level of shields, lessening the deterioration of PW50 at the time of off-track and narrowing an effective track width and with which a high yield is obtd. in HDD production. CONSTITUTION:This thin-film MR effect type magnetic head of a compound type having an MR element 3 and an electromagnetic induction type element for recording has the upper shield 5 and lower shield 1 laminated and formed on the upper and lower parts of the MR element 3. The inter-shield spacing between the upper shield 5 and lower shield 1 in the region of lead layers 41 existing at both ends of a magnetic flux detecting width A are formed to <=1.35 times the inter-shield spacing in the region of a magnetic flux detecting width A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film magnetoresistive effect type magnetic head (hereinafter referred to as a thin film MR effect type magnetic head) used in a hard disk drive device capable of ultra high density recording.

[0002]

2. Description of the Related Art In recent years, there has been a rapid increase in demand for miniaturization and increase in capacity of hard disk drive (hereinafter referred to as HDD) devices which are magnetic storage devices. Accordingly, there is an urgent need to improve the recording density of magnetic disks and magnetic heads used in HDD devices. In order to increase these capacities, it is necessary to increase the track density, linear recording density, and optimize the modulation method. Therefore, magnetic disks have high coercive force and high residual magnetic flux density. A metal thin film disk having a characteristic of low noise has been developed, and as a magnetic head, a metal in-gap head, a thin film head, and a laminated magnetic head in which a metal magnetic film is laminated have been developed.

All of these magnetic heads utilize the electromagnetic induction phenomenon, and the reproduction output thereof is proportional to the relative speed between the magnetic head and the magnetic disk. Therefore, when the magnetic disk becomes smaller and the diameter of the reproducing track becomes smaller, the relative speed between the magnetic head and the magnetic disk becomes lower, and as a result, sufficient reproduction output cannot be obtained. Therefore,
For example, Japanese Patent Application Laid-Open No. 4-137211 proposes a thin film MR effect type magnetic head which senses a magnetic flux from a magnetic disk by utilizing the MR effect.

A thin film MR effect type magnetic head using a conventional MR element will be described below. FIG. 4 shows a conventional thin film M
FIG. 3 is an enlarged view of a main part of an MR element part of an R-effect magnetic head,
This is seen from the magnetic recording medium side. FIG. 5 is a schematic view of a conventional thin film MR effect magnetic head during recording on a magnetic recording medium. Reference numeral 1 denotes a lower shield which is at least a magnetic flux detection width A which is a reproducing track area of a magnetoresistive element and which is formed of a soft magnetic material such as permalloy or sendust by a vacuum film forming method or a plating method, or a ferrite or the like. It is made of soft magnetic material. Reference numeral 2 is an insulating layer laminated on the lower shield 1 to magnetically separate the MR element and the lower shield 1. SiO ₂ or Al ₂ O ₃
An oxide such as is deposited by a vacuum deposition method such as vapor deposition or sputtering. Reference numeral 3 denotes an MR element, which is an Fe-Ni alloy or Co- showing a resistance change on the insulating layer 2 against an external magnetic field.
Ni alloy has several tens of nm to increase sensitivity to external magnetic field
The following particularly thin film is formed. These thin films are formed by a vacuum film forming method such as a vacuum vapor deposition method, a sputtering method or an ion beam sputtering method. Reference numeral 4 denotes a lead layer for supplying a current to the MR element 3 and detecting a voltage change thereof, which is in contact with the MR element 3 outside the magnetic flux detection width A.
The lead layer 4 has Au, Al, and
Cu, W or a laminated film thereof is used, and vacuum deposition method, sputtering method, ion beam sputtering method, CVD
The film is formed by a vacuum film forming method such as a method. Reference numeral 2'denotes an insulating layer on the MR element 3 and the lead layer 4, SiO ₂ and Al ₂ O ₃
An oxide such as is deposited by a vacuum deposition method such as vapor deposition or sputtering. Reference numeral 5 denotes an upper shield which is formed on the insulating layer 2'by a vacuum film forming method such as vapor deposition or spattering or a soft magnetic material having a width of at least the magnetic flux detection width A of the MR element 3 such as permalloy or sendust. ing. A recording gap 6 is formed on the upper surface of the upper shield 5 by vapor deposition of an oxide such as SiO ₂ or Al ₂ O ₃ or a vacuum deposition method such as sputtering. Reference numeral 7 denotes a recording core, which is formed by depositing a soft magnetic material such as permalloy or sendust on the recording gap 6 by a vacuum deposition method such as vapor deposition or sputtering or a plating method, and etching it into a predetermined shape by a physical or chemical method. Is formed. Reference numeral 8 is a protective layer, which is formed by depositing an oxide such as SiO ₂ or Al ₂ O ₃ by a vacuum deposition method such as vapor deposition or sputtering.

Here, the magnetic flux detection width of the MR element 3 for reproducing the thin film MR magnetic head is a width indicated by A, and the recording core width for recording is B.

As a result of manufacturing the conventional thin film MR effect type magnetic head through the above steps, the distance between the lower shield 1 and the upper shield 5 (hereinafter referred to as the shield distance) is the insulating layer 2.
2 ', the MR element 3, and the lead layer 4 are laminated, so that a shield step 9 is generated, and the inter-shield distance C in the area of the magnetic flux detection width A (reproduction track area) and the lead layer 4 are formed. There is a difference in the shield-to-shield distance from the shield-to-shield distance D in the region E (lead layer regions located at both ends of the reproduction track). On the other hand, Robert I Potter, I E E E, Transaction on Magnetics, MSA 1
00, 502 (1974) (Robert I. Pott
er, IEEE, Trans. Mag. 100,502
According to (1974)), the half value width PW50 (hereinafter referred to as PW50) of the isolated reproduction waveform, which is extremely important as a substitute characteristic value representing the linear recording density, and the shield distance C have an extremely close relationship with the head flying height as a parameter. Has been shown to be. When recording is performed on the magnetic recording medium with such a thin film MR effect type magnetic head, the recording facing surface magnetic field 10 is generated in the state shown in FIG. Here, the recording width on the magnetic recording medium is indicated by I.

[0007]

However, in the above conventional structure, the shield distance is the shield distance C in the magnetic flux detection width A portion shown by C in FIG.
The effect of the shield step 9 was not clarified. Then, when the influence of the shield step 9 (difference between the shield distance C and the shield distance D) was experimentally confirmed, it was found that the shield step 9 significantly affects the off-track characteristics or the effective track width of the PW50. It was Therefore, it has been found that there is a problem that the off-track characteristics of the PW 50 and the effective track width cannot be controlled only by the conventional regulation and control of the shield-to-shield distance C. It was also found that it is difficult to improve the characteristics by controlling only the shield-to-shield distance C in order to reduce the deterioration of the PW50 during off-track or to narrow the effective track width.

The present invention solves the above-mentioned problems of the prior art by reducing the shield step and reducing the PW50 during off-track.
It is an object of the present invention to provide a thin film MR effect type magnetic head capable of increasing the recording density by reducing the deterioration of the magnetic recording medium and narrowing the effective track width and obtaining a high yield in HDD manufacturing.

[0009]

In order to achieve this object, a thin film MR effect type magnetic head of the present invention is arranged such that the distance between the upper shield and the lower shield in the read layer regions located at both ends of the reproducing track is set to the reproducing track region. 1.35 times less than the distance between the upper shield and the lower shield,
Alternatively, the lead layer has a thickness of 0.15 μm or less.

[0010]

With this structure, since the shield step is made small, it is possible to reduce the deterioration of the PW 50 at the time of off-track and to make the effective track width narrow, and as a result, it is possible to improve the recording density.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an enlarged perspective view of a partial cross section of an MR element of a thin film MR effect type magnetic head according to an embodiment of the present invention. 1 is a lower shield, 2 and 2'are insulating layers,
Reference numeral 3 is an MR element, 5 is an upper shield, 7 is a recording core, and 9 is a shield step. Since these are the same as in the conventional example, the same reference numerals are given and description thereof is omitted. Reference numeral 11 is a coil made of a copper film or the like, and reference numeral 41 is a lead layer formed so that D / C, which is a ratio of distances between shields, is 1.35 or less.

The thin film M of the present embodiment constructed as described above.
The off-track characteristics of the PW50 and the effective track width of the R-effect magnetic head were measured. The constituent conditions of the sample are shown in (Table 1).

[0013]

[Table 1]

PW50 for the off-track of the sample was measured under the following conditions: 10 samples were prepared and a 3.5 "hard disk medium with a coercive force of 1800 (Oe) was used and the peripheral speed was 5.6 m / s and the flying height was 0.1 μm. 2 and the average of the normalized output dependences are shown in FIGS.
FIG. 3 is an off-track characteristic diagram of a PW50 of a thin film MR effect magnetic head according to an embodiment of the present invention and a conventional thin film MR effect magnetic head, and FIG. 3 shows a thin film MR effect magnetic head according to an embodiment of the present invention. FIG. 9 is an off-track characteristic diagram of a standardized output of a conventional thin film MR effect magnetic head. In addition, a summary of these measurement results is shown in (Table 2).

[0015]

[Table 2]

(Comparative Example) Ten thin film MR effect type magnetic heads of the conventional example were prepared, and under the same conditions as in the example,
Dependencies of the PW50 and the normalized output on the off-track of the sample were determined, and their averages are shown in FIGS. In addition, a summary of these measurement results is shown in (Table 2). As is clear from FIG. 2, in the comparative example, the PW50 during off-track
It can be seen that the deterioration is marked. The flat area of the PW 50 near off-track 0 was about 1.5 μm, which was equal to the difference between the recording core width B and the magnetic flux detection width A. This means that the PW50 is deteriorated as the magnetic flux detection section is deviated from the recording track, and the magnetic flux from the recording track in the area outside the magnetic flux detection width A, that is, the position of the lead layer 4 is detected. It can be said that the influence appears more strongly. Further, as is apparent from FIG. 3, the effective track width of the comparative example is larger than that of the example, and it is understood that the effective track width increases as the film thickness of the lead layer 4 increases. Off-track 0 also in the figure
The flat area in the vicinity is about 1.5 μm.
The same tendency as in off-track is observed. In this example, the effect of remarkably improving the above characteristics was confirmed by setting the thickness of the lead layer 41 to 0.15 μm or less and the shield distance ratio D / C to 1.35 or less. In this embodiment, the lead layer 41 is thinned in order to make the shield distance ratio D / C close to 1, but by flattening the surface of the insulating layer 2 ′ formed on the lead layer 41. It can be easily inferred that the same effect can be obtained. Thus, in the area of the magnetic flux detection width A, the distance C between shields and the lead layer 4
By reducing the difference in the shield distance D in the region E in which 1 is formed, it is possible to reduce the deterioration of the PW50 during off-track and narrow the effective track width, and as a result, the recording density is improved. And H
It has been revealed that an MR head having a high yield in DD manufacturing can be obtained.

[0017]

As described above, according to the present invention, the deterioration of the PW50 at the time of off-track can be reduced, the effective track width can be narrowed, the recording density can be remarkably improved, and the productivity and the reliability can be improved. A thin film MR effect type magnetic head having excellent properties can be realized.

[Brief description of drawings]

FIG. 1 is an enlarged perspective view of a partial cross section of an MR element of a thin film MR effect type magnetic head according to an embodiment of the present invention.

FIG. 2 is an off-track characteristic diagram of a PW50 of a thin film MR effect magnetic head according to an embodiment of the present invention and a conventional thin film MR effect magnetic head.

FIG. 3 is an off-track characteristic diagram of a standardized output of a thin film MR effect magnetic head according to an embodiment of the present invention and a conventional thin film MR effect magnetic head.

FIG. 4 is an enlarged view of a main part of an MR element part of a conventional thin film MR effect magnetic head.

FIG. 5 is a schematic view of a conventional thin-film MR effect magnetic head when recording on a magnetic recording medium.

[Explanation of symbols]

 1 Lower Shield 2, 2'Insulating Layer 3 MR Element 4 Lead Layer 5 Upper Shield 6 Recording Gap 7 Recording Core 8 Protective Layer 9 Shield Step 10 Magnetic Recording Facet Field 11 Coil

Claims (2)

[Claims] 1. A composite thin film magnetoresistive effect magnetic head having a magnetoresistive element and a recording electromagnetic dielectric element, comprising: an upper shield and a lower shield laminated on the upper and lower portions of the magnetoresistive element. And a shield distance between the upper shield and the lower shield in the read layer regions located at both ends of the reproduction track is formed to be 1.35 times or less than a shield distance in the reproduction track region. A characteristic thin-film magnetoresistive effect magnetic head. 2. The thin film magnetoresistive effect type magnetic head according to claim 1, wherein the thickness of the lead layer is 0.15 μm or less.