JPS6233317A - Thin film magnetic head - 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 the Invention The present invention relates to a thin film magnetic head used for reproducing high density magnetic recording media.

2. Description of the Related Art Conventionally, this type of thin film magnetic head has had a structure as shown in FIG. 4, for example. That is, a bias conductor thin film line (3) such as Au is formed on the surface of a ferromagnetic substrate (1) such as Mn--Zn ferrite with an insulating film (2) such as 8102 interposed therebetween. Furthermore, a Ni-
An MR element made of a magnetoresistive (MR) film (5) such as Fe is formed, and an 0o-Z
Core made of an amorphous magnetic film such as r<7),
<8+ is formed.

Problem to be Solved by the Invention The output E of the MR element is calculated as follows, where the current density flowing through the MR film (5), J1 specific resistance change is Δρ, and the length is 2 =, T-Δρ
, +e. Since Δρ and ρ are determined by the material and shape of the MR element, increasing J is a possible means of increasing the head output.

However, J cannot be increased without limit, and there is a maximum current density determined by the amount of heat dissipated by the materials surrounding the film. For example, in the case of a Ni-Fe film on a 5102 film, about 50
mA/μR. If more current is applied, the MR film will melt, so this current density determines the head output.

Therefore, an object of the present invention is to increase the output of the head by increasing the current that can be passed through the MR film using materials and structures that improve heat dissipation from the MR film.

Means for Solving the Problems The present invention provides a thin film magnetic head that detects signal magnetic flux from an X magnetic recording medium as a resistance change of an anti-magnetoresistance effect element formed on a six-handed frame substrate. The magnetoresistance effect element is formed on a substrate having a low co-heat dissipation property and hardness equivalent to that of a diamond plate.

Function: Due to the above-described configuration, the present invention has good heat dissipation from the MR film, and can be operated at a current density that is more than twice that of the conventional device, thereby achieving high output.

Embodiment FIG. 1 shows a sectional view of an embodiment of the thin film head of the present invention.

An MR film Ql made of a Ni-lFe film with a thickness of 0.05p73 is placed on the diamond plate (9) with a thickness of os mm.
is formed, and electrodes (not shown) of Au, On, etc. for resistance change detection are attached to both ends in the track width direction to form an MR element. On top of that, an amorphous magnetic film such as Co-Nb-Zr or an N1
-Fθ, magnetic cores QB and α made of a ferromagnetic thin film such as Sendust are formed. For the non-magnetic insulating film 0υ, a film with good thermal conductivity such as a diamond film is more effective, but most of the heat from the MR film α [81
0. Even if a general insulating film such as A40S or A40S is used, a larger current can be passed compared to a head using a conventional ferrite substrate.

Furthermore, there is a bias conductor thin film α made of Au, Cu, A7, etc. for applying a bias magnetic field to the MR film αl via an insulating film α, and a magnetic core αη made of a ferromagnetic thin film sandwiching a nonmagnetic insulating film αG. is formed.

The thin film magnetic head of the present invention converts the signal magnetic flux from the magnetic recording medium detected in the gap formed by the magnetic cores α and αD into M
The R film α value is detected as a resistance change of the MR film a1. The thermal conductivity of diamond is approximately 2100 w/-, which is approximately 50 times that of silver, so diamond is formed directly on it.
The fusing current density of the R film +II was more than double that of the case where it was formed on the conventional Sin film. Furthermore, since diamond is very hard with a Vickers hardness of 10,000 kf/mrn, it is difficult to wear when used for the head substrate.

Even if a head substrate made of metal or ceramic with a diamond film or a high-hardness carbon film formed on the surface of the substrate is used instead of the diamond plate mentioned above, a large fusing current density similar to that of a diamond plate can be achieved due to heat dissipation through the film. is obtained. High-hardness carbon film is a general term for carbon films that have properties similar to diamond films, such as ecarbon (a carbon film created by ion beam sputtering). Diamond films or high-hardness carbon films can be made by applying high frequency to OH4 gas in a vacuum to turn it into plasma, applying voltage to accelerate it and depositing it on the substrate, or by sputtering carbon onto the substrate with argon gas and simultaneously depositing it on the substrate. A film can be formed on a substrate even at a relatively low temperature using methods such as bombardment with hydrogen gas.

Whether a crystalline diamond film or a high-hardness carbon film similar to diamond will be obtained depends on the film formation conditions, but even a high-hardness carbon film with properties similar to diamond can be obtained if appropriate film formation conditions are selected.

FIG. 2 shows the relationship between the output and the MR lightning current of a conventional head (b) in which 8102 is used as an insulating film and a head (L) in which a 5 μm thick diamond film is formed on a beryllia substrate according to an embodiment of the present invention.

50 mA/l1rr with a conventional head? The MR film is disconnected at 100 mA in the head of this embodiment.
A current of 7'μ- or more can flow, and a correspondingly large output can be obtained.

FIG. 3 shows another embodiment of the thin film magnetic head of the present invention.

A part of the NiZn substrate is cut out and a diamond block is embedded. Thereon, an MR film αQ1, a magnetic core αz1α, and a bias conductor thin film α9 are formed via nonmagnetic conductor thin films αυ and a, respectively. This head uses the magnetic core a3 as the main pole to efficiently reproduce signals recorded on a perpendicular recording medium. Since the MR film is formed on diamond as in the first embodiment, a large signal detection current can be passed.

Effects of the Invention According to the present invention, M
By forming the R film, the current density that can be passed through the MR film is more than twice that of a conventional head configuration, so an output voltage that is more than twice as high can be obtained using the same recording medium.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a first embodiment of the thin film magnetic head of the present invention, FIG. 2 is a characteristic diagram of the thin film magnetic head of the present invention, and FIG. 3 is a second embodiment of the thin film magnetic head of the present invention. Example cross section,
FIG. 4 shows a cross-sectional view of a conventional thin film magnetic head. 9: Diamond plate 10: MR film 11: Insulating film [2: Magnetic core 13: Magnetic core 14: Insulating film 15: Bias wire 16: Insulating film 17: Magnetic core Patent applicant Matsushita Electric Industrial Co., Ltd. Agent Patent attorney Isao Abe Figure 1 H1 defect (1-2 Figure 2

Claims (1)

[Claims] In a thin-film magnetic head that detects signal magnetic flux from a magnetic recording medium as a change in resistance of a magnetoresistive element formed on a substrate, the magnetoresistive element is made of a diamond plate having low co-heat dissipation properties and hardness. A thin film magnetic head characterized by being formed on a substrate having an effect equivalent to that of the thin film magnetic head.