JPS60177421A - Magneto-resistance effect head - Google Patents

Abstract

PURPOSE:To enable efficient reproduction even with a signal magnetic field of an extremely short wavelength by increasing the width of the part near the juncture of leads connecting to both ends of an MR elememt and forming a fine slit in proximity to the MR element so as to face said elememt. CONSTITUTION:Lead patterns 23, 24 consisting of conductors are connected to both ends 21, 22 of a magneto-resistance effect element (MR element) 20 and the parts 25, 26 near the juncture are widened in the width and an extremely fine slit S is formed therein in proximity to the element 20 so as to face the element. A magnetic field in the direction where the demagnetizing field is negated is generated in said space S. Reproducing efficiency is decreased by the demagnetizing field in the short wavelength signal magnetic field of high density recording where the change in the signal magnetic field is acute in the prior art but the effect of negating the demagnetizing field is generated by the formation of the slit S, by which the efficient reproduction is made possible even in the signal magnetic field of an extreme short recording wavelength.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a technique for improving the reproduction efficiency of a magnetic flux responsive magnetoresistive head.

Technical Background Thin film magnetic heads suitable for POM magnetic recording/reproducing etc. can be classified into inductive heads similar to bulk ring heads and magnetic flux responsive magnetoresistive heads. When a magnetoresistive head is made entirely of metal ferromagnetic elements, its resistivity ρ changes depending on its own magnetization M, which changes in response to an external magnetic field, and the angle θ formed by its own magnetization, fN, and flow. Magneto-Resistance E
ffect) and is generally called MR Hehera, so it will be referred to as MR Hehera from now on. Now, as shown in Fig. 1, the MR Hehera is a 1f element made of a strong metal material, and both ends 2.3 are connected to a lead 4.5 to which electricity is applied from the entire outside, and the element IK is applied. current 1
When a full external magnetic field of field strength H is applied in the direction perpendicular to ,
Let the angle between the magnetization M of element 1 and the current ■ be the total θ, and lead 4
Letting the resistance between both ends of the lead 50 be the specific resistance ρ, it is expressed as follows due to the above-mentioned magnetoresistive effect.

That is, ρ(-ρ/cos2θ 10ρ soil 5in2θ#
ρ2−Δρsin 2θ ・・・・・−(I) However, ρ7 is the resistivity component parallel to the current XV and the resistivity component perpendicular to the flow of p□Ir1S, which is expressed as above Δρ−ρ7−ρ .

Since the angle θ, which is a parameter of the resistivity ρ shown in equation (1), is fully influenced by the magnetic field H, the relationship between the magnetic field H and the resistivity ρ is expressed by curve 7 in Figure 2. As can be seen from this curve 7, the range 8 in which the ρ-H relationship changes linearly is narrow, so generally a bias magnetic field with a strength HB is constantly applied to the external magnetic field. , when the entire signal magnetic field shown by curve 9 with intensity Hl is applied, it is faithfully reproduced as a change in resistivity ρ shown by curve lO.

By the way, since the MR heherer applies a bias magnetic field HBt to the element 1 as described in "2," a demagnetizing field Hdt is generated in the width direction of the element 1, as shown in FIG. Since the magnitude of the demagnetizing field Hd increases from the central part of the element l toward the ends in the width direction, the actual distribution of the bias magnetic field HB' in the MR heherer is in the upward direction as shown in the curve 11 shown in FIG. It is convex and not constant. Therefore, in a short wavelength signal magnetic field H1 in which the signal magnetic field (↓) changes rapidly, that is, the recording density is high, there is a drawback that the reproduction efficiency decreases.

OBJECTS OF THE INVENTION It is an object of the present invention to completely eliminate the reduction in reproduction output of MR-RAD due to the influence of the demagnetizing field, which becomes more problematic as the recording wavelength r becomes shorter.

Structure of the Invention In order to achieve all of the above-mentioned objects, the present invention expands the width of the lead connected to both ends of the MR element in the vicinity of the connection part,
The main feature is that the slit is closely opposed to the MR element and an extremely thin slit is formed.

In other words, the present invention fully fulfills the role of lead bias magnetic field compensation, and does not require any extra demagnetizing field canceling means. This invention can be manufactured in the conventional manner except for setting the structure of the leads, so it is highly practical.

Embodiment of the Invention FIG. 4 is a conceptual diagram of an fMR head, which fully explains the premise 1 and the principle of an embodiment of the present invention.

Reference numeral 1 20 denotes an MR element formed with a thin rectangular thin film pattern, and lead patterns 23.2ai of ferromagnetic and conductive material are connected to both ends 21.22 in the longitudinal direction of the MR element. These lead patterns 23 and 24 are symmetrical, and their connecting portions 25.degree. 26 are significantly wider than the other portions, and are closely opposed to the MRR element 20 with a minute gap δ. However, the connection vicinity parts 25 and 146 are
They are separated by a minimum insulation distance l. Now, when a full bias magnetic field HB similar to that of the conventional L7Th shown in FIG. 1 is applied to this MR heherer, the MRR element 20. Connection vicinity part 25
．． The slit space sVi surrounded by
As a result, in FIG. 4, a load 28.2B, . . . , is generated at one point on the surface of the two MR elements 2'7, 27, . . . , and the connection vicinity portion 25, 26, respectively. Therefore, as shown in FIG. 5, which is an enlarged view of the circle A which is a part of the slit space S, in the slit space S, the demagnetizing field Ha
A magnetic field Hcom is formed in the direction of total cancellation. Therefore,
If the entire distribution of the actual bias magnetic field HB# in the MRR element 20 similar to that shown in FIG. 3 is drawn in comparison with the conventional case, it will become like the curve 29 shown in FIG. 6, and a flat distribution characteristic will be obtained. be.

FIG. 7 is a perspective view of a vertical MR heherer based on the above-described principle. Here, the same figure numbers as those shown in FIG. 4 are of course the same names, and 30 is a substrate made of glass or sapphire, and 31 is a ferromagnetic alloy such as permalloy, which are attached in correspondence with all head positions. 1st i shield layer, 3
2 is an insulating or non-magnetic film such as 5i02 film or j120 film.
．． 1 film.

The reference numeral 33 designates a magnetic tape as a magnetic recording medium, and its magnetic track Tf corresponds to the MRR element 20 formed on the SiO□ film 32.

In addition, the lead patterns 23 and 24 are also made of the SiO2 film 32.
A 25% slit space S formed above and near the connection is shown. And 34 is 51 which is similar to figure number 32.
02 film or A7I203@, 35 is a conductor film for applying to the bias magnetic field HB' of the MRR element 20, and 36 and 37 are its bias leads. Sara (738.

is a second magnetic shield layer provided on the conductive film 35 [through the entire insulating film 39 such as a 5i02 film or an Ag2O3 film.

This MR Hehera uses MRR element 20 as Fe2O-Ni20.
The alloy thin film is used, and the lead patterns 23 and 24 are Fe-1
It is assumed that the surface of the thick film of the Ji alloy is completely coated with Au, and the MR
If the element 20 wrist drive width dimension W is designed to be less than 2 μm in total and the gap dimension δf in the slit space S is less than 2 μm, the bias magnetic field characteristic curve 29 shown in FIG. This results in a regeneration efficiency that is sufficiently greater than .

In the above embodiment, a so-called vertical MR heherer was described, but the present invention is not limited to this.
For example, it is also applicable to a horizontal MR hehera.

Effects of the Invention As is clear from the description of the embodiments, this invention has the effect of completely canceling out the demagnetizing field by the slit formed by the MR element itself and the leads connected to it, so it is possible to record at an extremely short recording wavelength. It has the effect of being able to efficiently reproduce even a signal magnetic field of . Moreover, according to this invention, the reproduction efficiency is equal to or higher than that of conventional long recording wavelengths, and the MR hehera structure does not become complicated and can be manufactured using the conventional manufacturing process. It has great advantages that can be applied.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram showing a conventional magnetoresistive head 2, FIG. 2 is a ρ-H characteristic curve diagram showing its general characteristics, and FIG. 3 is a bias magnetic field distribution exerted by the magnetoresistive element Gτ. 2-f (advance diagram, FIGS. 4 to 7 are related to one embodiment of the present invention, FIG. 4 is a front view of main parts showing the concept 2 of the magnetoresistive element, and FIG. 5 is a front view of main parts. , FIG. 6 is a characteristic curve diagram showing the bias magnetic field distribution 2 of A, and FIG. 7 I-1 is a perspective view showing its specific structure 2. 20...Magnetic Resistance effect element, 21.22...Both ends, 23, j4...Lead pattern, 25.26...Fist connection vicinity, S...Slit space.

Claims (1)

[Claims] A lead connected to both ends of a magnetoresistive element. This magnetoresistive head is characterized in that the width of the area near the connection part is fully expanded, and an extremely thin slit is formed so as to closely face the magnetoresistive element.