JPS62145527A - Compound type thin film magnetic head - Google Patents

Abstract

PURPOSE:To prevent extremely the loading of a stress on the upper side an MR element, and to prevent the deterioration of the magnetic characteristic of the MR element and a yoke by arranging a magnetic induction type thin film magnetic head at the lower side and an MR type thin film magnetic head at the lower side and an MR type thin film magnetic head at the upper side and using the upper side core of the magnetic induction type thin film magnetic head together with the lower side core of the MR type thin film magnetic head. CONSTITUTION:At the lower side, a magnetic induction type thin film magnetic head A is laminated, and at the upper side, a yoke type MR type thin film magnetic head B is laminated. For winding coils 6 and 7, a recording electric current is energized at the time of recording, and at the time of reproduction, the bias electric current to give a bias magnetic field to an MR element 8 is energized. When the recording electric current is energized to the coil 7, the MR element 8 is several hundred Angstrom magnetic films, magnetically saturated, a magnetic permeability is close to 1, at an upper side yoke 1, the magnetic flux will not flow, and the magnetic pattern on the recording media is not disturbed. The influence of a response to the MR element 8 and the yoke 1 is hard to be received since the element is not formed on them.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to the structure of a composite thin film magnetic head capable of performing magnetic recording and reproduction in magnetic disk devices, magnetic tape devices, and the like.

<Prior Art> Conventionally, thin-film magnetic heads use a magnetic induction wire-wound type head for recording and playback using the same head.
It was necessary to increase the number of conductor coils passed through the magnetic core, but this was difficult because thin film formation technology was used.

- Magnetoresistive effect of strong ferromagnetic thin film (hereinafter referred to as MR)
It is known that a thin film magnetic head using a magnetic head has many advantages over the above-mentioned wire-wound type head. In other words, when the transport speed of the magnetic recording medium is low, since an output directly proportional to the magnetic flux can be obtained, it is possible to reproduce the signal regardless of the transport speed, and even when the transport speed is low, the winding It has the advantage that a higher output reproduction signal can be obtained than a linear magnetic head.

In addition, in actual use, rather than constructing a thin-film magnetic head with a single MR element, the MRT (receiver section) is separated from the head tip, and a magnetic flux introduction path (hereinafter referred to as a yoke) that guides the magnetic flux generated in the magnetic recording medium to the MR element section is used. A thin-film magnetic head called a yoke-type MR head, which has a yoke type MR head, is more effective in improving signal resolution and MR hydrogen durability, and in recent years this type of head has become popular for fixed-head digital audio playback. It is attracting attention as a head. (For example, Japanese Society of Applied Magnetics, 39th Research Meeting Material P61-27
2 "Thin Film MR Head") In this way, it is considered optimal to use a conventional wire-wound type thin film magnetic head for recording and a yoke type MR head for reproduction to achieve high-quality magnetic recording and reproduction. .

However, in a composite magnetic head in which these two heads are manufactured separately and combined, if the inside of the track is narrow, it becomes difficult to align the recording track and the reproduction track.

Furthermore, conventionally known composite thin-film magnetic heads are known to have a wire-wound thin-film magnetic head stacked on top of an MR-type thin-film magnetic head. There is a problem in that the magnetic properties of the MR hydrogen element yoke deteriorate due to stress from the single winding type thin film magnetic head formed above the hydrogen element. Since the bias conductor of the magnetic resonance element is independent from the recording head coil conductor, there is a problem in that the structure is complicated.

<Objective of the Invention> Therefore, the object of the present invention is to provide a composite thin film magnetic material which can prevent deterioration of the magnetic properties of the MR hydrogen yoke by minimizing stress on the upper side of the MR yoke, and which has a simple structure. The purpose is to provide the head.

<Structure of the Invention> In order to achieve the above object, the composite thin film magnetic head of the present invention has a magnetic induction type thin film magnetic head on the lower side and an MR magnetic head on the upper side in order to prevent stress from being applied to the upper side of the MR hydrogen element. MR type thin film magnetic head is arranged, and the upper core of the magnetic induction type thin film magnetic head is also used as the lower core of the MR type thin film magnetic head.

Further, it is preferable that the winding coil of the magnetic induction type thin film magnetic head is also used as an MR hydrogen element bias conductor of the MR type thin film magnetic head.

<Function> With the above configuration, the upper yoke of the MR hydrogen element MR type thin film magnetic head is less susceptible to stress, the deterioration of the magnetic properties of the MR hydrogen element upper yoke is prevented, and the structure is simplified and costs are reduced. Ru.

Further, the winding coil of the magnetic induction type thin film magnetic head is M
If it is also used as an MR hydrogen bias conductor for an R-type thin film magnetic head, the structure will be simplified and costs will be reduced.

<Embodiment> FIG. 1 is a schematic diagram showing the cross-sectional structure of a towing type thin film magnetic head in a direction perpendicular to the width direction of the trunk of an embodiment of the present invention. A magnetic induction type thin film magnetic head 8 is stacked on the upper side, and a yoke type MR type thin film magnetic head B is stacked on the upper side. In FIG. 1, 5 is a magnetic substrate for the magnetic induction type film magnetic head, which is usually made of Mn Z
Use n-ferrite or Ni-Zn ferrite. Also,
A groove 9 is formed in order to embed the winding coil 6 in the magnetic substrate 5.
This is provided. The coil 6 is wound in series with a coil 7, which will be described later, as shown in FIG. 2, and is made of Cu, A(!-Cu, etc.).
It is possible to increase the distance between the lower magnetic substrate 5 and the coil 6 to suppress leakage of magnetic flux from the central yoke 3 to the lower magnetic substrate 5 during recording.

The central yoke 3 is made of a magnetic material and is used for both recording and reproduction, and is usually made of a sputtered film or a plated film of Permalloy or Sendust.

4 is a recording head gap portion filled with an insulator 22 such as 5 iOz. During recording, the lower magnetic substrate 5 and the central yoke 3 are magnetized by the magnetic field generated by the winding coil 6.7, and a recording magnetic field is generated in the recording gap 11. The recording head cap 4 is 0 for high-density recording.
．． The thickness is 5 μm or less, and therefore, the bonding with the central yoke 3 on the rear side of the lower magnetic substrate 5 can be easily performed. The groove 9 is filled with an insulator 21 such as low melting point glass or 5in2. The path of the current flowing through the winding coil 6.7 is in the form of a circuit around the central yoke 3, as shown in FIG. Reference numeral 1 designates the upper yoke of the yoke type MR type thin film magnetic head B, which is usually made of a high permeability magnetic material such as permalloy or CoZr amorphous film formed by sputtering, plating, or vapor deposition.

25.26, 27f; l: Insulating film, usually a sputtered film such as 5i02. 8 is an MR element in which a permalloy film with uniaxial anisotropy is formed by vapor deposition.
It is covered with insulating films 26 and 27.

The width of the MR element 8 is about IO μm, and the film thickness is several hundred.

Reference numeral 2 denotes a read gap which determines the resolution of the yoke type MR type thin film magnetic head, and is approximately 0.5 μm or less. 7 is a conductor that generates a bias magnetic field in the MR element 8 and serves as a winding coil during recording, and is made of Cu, AQ-C.
u etc. are used.

In the present invention, a recording current is applied to the winding coil 6.7 during recording, and a bias current for applying a bias magnetic field to the MR element 8 is applied during reproduction.

A related problem is that during recording, a magnetic field is generated in the head gap 2 for reproduction in addition to the recording magnetic field generated from the head gap 4 for recording, and the recording medium is recorded using the head gap 4 for recording. - The magnetization pattern of H may be disturbed. However, in the present invention, when the recording current is applied to the coil 7, the MR element 8 is a magnetic film of several hundred.
Magnetically saturated and magnetic permeability approaches 1. Therefore, no magnetic flux flows through the upper yoke 1, and no magnetic field is generated in the reproducing head gap 2, so that the above-mentioned problem does not occur. In addition, the magnetization pattern on the recording medium may be disturbed by the magnetic field generated in the recording gap 4 by the bias current for applying a bias magnetic field to the MR probe 8 during reproduction, but the bias current value Since this is small, the recording magnetic field generated in the recording head gap 4 is weak, and the above problem does not occur.

Furthermore, since no element is formed on the MR cord 8 and yoke l described in the prior art, they are less susceptible to the influence of stress, and deterioration of their magnetic properties can be prevented. Further, since the central yoke 3 is used for both the magnetic induction type thin film magnetic head A and the yoke type MR type thin film magnetic head B, the structure is simplified.

Note that the lower magnetic substrate 5 is made of Ni-Zn ferrite, Mr.
+- Since it is formed from Zn ferrite, it has a high coercive force H.
When recording on a recording medium of approximately C-15000e, the saturation magnetic flux density of the lower magnetic substrate 5 becomes a problem. In that case, if a material II having a high saturation magnetic flux density such as Sendust is deposited on the lower magnetic substrate 5 such as ferrite as in the embodiment shown in FIG. can also be recorded. Alternatively, as shown in FIG. 4, a material 13 having a high saturation magnetic flux density such as Sendust is deposited on a flat Ni--Zn ferrite or Mn--Zn ferrite magnetic substrate 12, and then holes 14 are formed.

After that, similarly to the groove 9, the hole 14 is filled with low melting point glass 29 or the like, and then the conductor 6 is formed. In this way, F/l 9 as shown in FIG. 3 is not required.

<Effects of the Invention> As is clear from the above, according to the present invention, the MR element and the upper yoke are less susceptible to stress, deterioration of magnetic properties can be prevented, and the structure can be simplified and costs can be reduced.

Further, if the bias conductor for applying a bias magnetic field to the MR element is also used as the recording winding coil, the structure can be further simplified and costs can be reduced.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the cross-sectional structure of a composite thin film magnetic head according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing the relationship between the winding coil 7 and the central yoke 3. 3 and 4 are schematic diagrams of other embodiments that are modified from the embodiment of FIG. 1, respectively. l...'2 (Yoke between, 2... Rad gap for regeneration, 3... Center yoke,
4... Henod gap for recording, 5... Lower magnetic substrate, 6, 7 Coil, 2'l, 22
．． 25, 26.27 - Insulator, 11.13... High saturation magnetic flux density magnetic material, 12... Magnetic substrate.

Claims (3)

[Claims] (1) In a composite thin-film magnetic head in which a magneto-induction thin-film magnetic head and a magnetoresistive thin-film magnetic head are stacked vertically, the magneto-induction thin-film magnetic head is placed on the bottom, and the magneto-induction thin-film magnetic head is A composite thin-film magnetic head characterized in that the upper core also serves as the lower core of the magnetoresistive thin-film magnetic head. (2) The composite thin film magnetic head according to claim 1, wherein the magnetoresistive thin film magnetic head is a yoke type magnetoresistive thin film magnetic head. (3) The winding coil of the magneto-inductive thin-film magnetic head is also used as a bias conductor of a magnetoresistive element of the magnetoresistive thin-film magnetic head. Composite thin film magnetic head.