JPH03189915A - Magneto-resistance effect type head - Google Patents

Abstract

PURPOSE:To prevent the generation of a battery effect generated in the joint parts of an MR (magneto-resistance effect type) element and a conductor pattern and to stabilize the characteristics thereof by constituting the conductor pattern of the same material as the material of the MR element. CONSTITUTION:The joint parts of the conductor pattern 5 and the MR element are not different metals if the MR element 2 and the conductor pattern 5 are constituted of the same material and, therefore, the battery effect does not arise and the corrosion of the MR element 2 does not arise. The electric resistance of the conductor pattern 5 is decreased by forming the conductor pattern 5 to the sectional area larger than the sectional area of the MR element 2 and, therefore, even 'Permalloy(R)' or Co-Ni alloy of the relatively large electric resistance is usable sufficiently as the conductor pattern. The cutting of the MR element 2 by corrosion or the flawing of a magnetic recording medium and magnetic head by the product of corrosion are prevented in this way and the stable characteristics are obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetoresistive magnetic head for reproducing magnetic signals.

Conventional technology Magnetoresistive heads (hereinafter abbreviated as MR heads) can obtain a constant playback output regardless of the relative speed with the medium, so they can be used to reproduce signals in rotary encoders and video tape recorders that take advantage of this characteristic. It is widely used in industrial sensors, etc. A conventional MR head will be explained below.

FIG. 3 is a perspective view showing a conventional MR head. In FIG. 3, 1 is an insulated substrate, and 2 is a magnetoresistive element (hereinafter abbreviated as MR element) formed on the substrate and made of a ferromagnetic thin film such as permalloy or C0-N1 alloy.
3 is Au+Al.

This is a conductor pattern made of a metal with good electrical conductivity such as Cu.

The operation of the MR head configured as above will be explained. First, a constant current is passed through the MR element 2 through the conductor pattern 3. When a magnetic field from a medium etc. enters the MR element 2 in this state, the electrical resistance of the MR element 2 changes depending on the strength of the magnetic field. At this time, since a constant current is flowing through the MR element 2, a change in the electrical resistance of the MR element 2 causes a change in voltage between the two conductor patterns 3.This voltage change is converted into a magnetic signal. Take it out as a signal.

Problems to be Solved by the Invention However, in the above-mentioned conventional configuration, since the joint between the MR element 2 and the conductor pattern 3 brings dissimilar metals into contact with each other, when humidity is high, a battery action occurs at the joint.
The MR element 3 sometimes corroded. This corrosion causes M
The electrical resistance of the R element 2 becomes large, resulting in data reading errors, and as corrosion progresses as shown in FIG. 4, the MR element 2 may be completely cut off. Particularly when used in a hard disk drive, if the corrosion products 4 shown in FIG. 3 come off due to vibration or the like and get between the magnetic recording medium and the flying surface of the slider on which the MR head is mounted, the magnetic disk may be damaged. There have been cases where it has become impossible to read the data that was recorded due to damage.

The present invention aims to solve the above-mentioned conventional problems,
It is an object of the present invention to provide a magnetoresistive head that can prevent battery action occurring at the junction between an MR element and a conductor pattern and obtain stable characteristics.

Means for Solving the Problem In order to achieve this object, the conductor pattern was constructed of the same material as the MR element.

Function: With this configuration, it is possible to prevent battery action from occurring between the MR element and the conductor pattern. Embodiment FIG. 1 is a perspective view showing an MR head in an embodiment of the present invention. In FIG. 1, 1 is a substrate and 2 is an MR element, which are the same as the conventional structure. 5 is a conductor pattern, and the conductor pattern 5 is made of the same material as the MR element. Here, if the MR element 2 is made of permalloy, the conductor pattern 5 is also made of permalloy, and if the MR element 2 is made of Co-Ni alloy, the conductor pattern 5 is also made of Co-Ni alloy. . Further, the conductor pattern 5 is thicker than the MR element 2. This is to increase the cross-sectional area of the good conductor pattern 5, thereby reducing the electrical resistance as much as possible.If the MR element and the conductor pattern are integrally formed, the cross-sectional area of the conductor pattern This is because the cross-sectional area of the MR element becomes the same as the cross-sectional area of the MR element, and the electrical resistance becomes large.Furthermore, after the MR element and the conductor pattern are integrally formed, a layer that is the same as the MR element is added on top of the conductor pattern. It is possible to increase the cross-sectional area by forming an auxiliary pattern using a material, but in this case, the auxiliary pattern must be formed well on the conductor pattern, which complicates the manufacturing process and reduces productivity. Deteriorate.

FIG. 2 is a perspective view showing another embodiment. In FIG. 2, 1 is a substrate, 2 is an MR element, and 5 is a conductor pattern, which are the same as those shown in FIG. A yoke pattern 6 is connected to the MR element 2 and extends to the medium facing surface.The yoke pattern 6 is provided so that the magnetic field can efficiently flow into the MR element 2. This yoke pattern 6 is also M
It is made of the same material as the R element 2.

As described above, according to this embodiment, since the MR element 2 and the conductor pattern 5 are made of the same material, the joint part between the conductor pattern 5 and the MR element 2 does not become a sign of dissimilar metals, so that the battery operation is prevented. Therefore, corrosion of the MR element 2 does not occur.

Also, by making the cross-sectional area of the conductive pattern 5 thicker than the cross-sectional area of the MR element 2, the electrical resistance of the conductive pattern 5 can be made smaller, so it is possible to reduce the electrical resistance of the conductive pattern 5. Even alloys can be used satisfactorily as conductor patterns.

Effects of the Invention In the present invention, since the conductor pattern is made of the same material as the MR element, it is possible to prevent battery action from occurring between the MR element and the conductor pattern, so that the MR element is not cut due to corrosion, It is possible to prevent corrosion products from damaging the magnetic recording medium and magnetic head, and stable characteristics can be obtained.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a magnetoresistive head according to an embodiment of the present invention, FIG. 2 is a perspective view showing a magnetoresistive head according to another embodiment of the invention, and FIG. 3 is a perspective view showing a magnetoresistive head according to another embodiment of the invention. FIG. 4 is a perspective view showing a resistance effect type head, and FIG. 4 is a side view showing a conventional magnetoresistive head in a corroded state. ■...Substrate 2...MR element 5...Conductor pattern 6...Yoke pattern

Claims (2)

[Claims] (1) A substrate, a magnetoresistive element provided on the substrate, and a conductor pattern provided on the substrate and bonded to the magnetoresistive element, the magnetoresistive element and the conductor pattern being connected to each other. A magnetoresistive head characterized by being constructed of the same material. (2) The magnetoresistive head according to claim 1, wherein the cross-sectional area of the conductive pattern is larger than the cross-sectional area of the magnetoresistive element.