JPH01315016A - Magneto-resistance effect type head - Google Patents

Abstract

PURPOSE:To suppress the generation of magnetic domains in a sensing part having two terminals consisting of thin films of a soft magnetic material and to microminiaturize the sensing part as well as to improve recording density by providing a conductor layer inserted between the two terminals in the form of intersecting orthogonally with the sensing part. CONSTITUTION:The terminals 12-1, 12-1 consisting of the thin films of the soft magnetic material are led out of both ends of the sensing part 10 the resistance value of which changes with magnetism. The conductor layer 16 intersects orthogonally with the plane of the sensing part 10, has a step in the middle part and is inserted between the terminals 12. A magnetic field is impressed via the terminals 12 in the direction EA of the axis of easy magnetization of the sensing part 10 when current is supplied to the conductor layer 16 from a constant current source. The generation of the magnetic domains is suppressed and Barkhausen noises are decreased when the magnetic field is impressed in the axis EA direction from the outside. The high-quality reproduction is executed with low noises in this way even if the track width of the sensing part is shortened in order to increase the recording density of the magnetic disk.

Description

[Detailed Description of the Invention] [Summary] This invention aims to effectively suppress Barkhausen noise in a magnetoresistive head (MR head) that reproduces information recorded on a magnetic recording medium by utilizing the magnetoresistive effect. , a thin film magnetoresistive element in which terminals made of a soft magnetic thin film are drawn out from both sides of a sensing part whose resistance value changes according to magnetism, and a thin film magnetoresistive element in which terminals made of a thin film of soft magnetic material are drawn out from both sides of a sensing part whose resistance value changes according to magnetism, and a connection between the two terminals in an orientation perpendicular to a plane containing the sensing part. and a conductor layer through which the intermediate portion is inserted near the sensing portion.

[Industrial Field of Application] The present invention is applied to a magnetoresistive head that reproduces information recorded on a magnetic recording medium by utilizing the magnetoresistive effect.

In this type of head, changes in the magnetic flux generated by the magnetic disk or magnetic tape are replaced by changes in resistance value due to the magnetoresistive effect, so magnetically recorded information can be reproduced as changes in voltage from the current flowing through the head.

[Prior art] No. 51! ! and the 6th Ili! Section I describes the configuration of a conventional magnetoresistive head, and here
Information recorded on the magnetic disk 50 shown in the figure is being reproduced.

The reproduction is performed by the sensing section 10 of the thin-film magnetoresistive element 14, and as shown in FIG.
The tip of the head is a head reproducing surface 52 facing the magnetic disk 50.
It is said that they are on par with each other.

Then terminals 12-1.
12-2 are each pulled out, and the terminals 12-1.12
-2 are connected to conductor layers 54-1 and 54-2 for energization, respectively.

Further, in FIG. 5, a shield layer 56 is provided in front of the magnetoresistive element 14, and a magnetic ferrite substrate 5 is provided behind it.
8 are arranged respectively, and their arrangement can be understood from FIG.

Note that the magnetoresistive element 14 and the shield layer 56 are
In FIG. 5, conductive layer 54-1.54-2 and terminal 12-1.12-
A detection current I is supplied from the outside to the sensing section 10 via the sensing section 2, and a detection current (2) flows along the head reproducing surface 52 in the sensing section 10.

The sensing unit 10 has uniaxial magnetic anisotropy in which the detection current ■ is parallel to the easy magnetization axis EA, and the magnetic disk 50
Reproduction is performed with the highest efficiency when the magnetism is perpendicular to the axis of easy magnetization EA.

[Problems to be Solved by the Invention] Here, given the track width of the magnetic disk 50, the length of the sensing M10 shown in FIG. 5 is determined in accordance with this.

The track width is required to be narrowed to increase the recording density, and is required to be 10 μm or less.

In that case, due to the decrease in the length of the sensing part, the magnetic domain is
Barkhausen noise is more likely to occur.

The level of this Barkhausen noise increases as the track width (that is, length) becomes narrower, and therefore, in order to further increase the recording density of the magnetic disk 50, suppressing this noise becomes an important issue.

The present invention has been made in view of the above-mentioned conventional problems,
The purpose is to provide a magnetoresistive head that can effectively suppress Barkhausen noise.

[Means for Solving the Problems] In order to achieve the above object, the present invention is characterized in that a conductor layer 16 is provided as shown in FIG.

In the sensing section 10 shown in the figure, the resistance value changes depending on the magnetism, and from both sides terminals 12-1.
12-2 are each pulled out.

The intermediate portion of the conductor layer 16 is inserted between the terminals 12-1 and 12-2 in the vicinity of the sensing portion in a position perpendicular to the plane including the sensing portion 10.

[Operation] When the current i is supplied to the conductor 71116 as shown in FIG. 2, a magnetic field H is applied in the sensing section 10 in the direction of the current (i.e., the easy magnetization axis EAO axis direction).

This suppresses the generation of magnetic domains in the sensing section 10,
Barkhausen noise is therefore reduced.

[Embodiments] Hereinafter, preferred embodiments of the head according to the present invention will be described based on the drawings.

The first embodiment is explained in FIGS. 1 and 2, the second embodiment is explained in FIG. 3, and the third embodiment is explained in FIG. 4. Illustrations and explanations of members that are the same as those in the figures are omitted.

However, the magnetoresistive element 14 is a thin film made of NiFe, and a conductive layer 54-1.5 for head current supply is used.
4-2 is made of Cu, kQ, etc.

The shield layer 56 is made of a ferromagnetic material such as NiFe or CoZr, and the conductor N16 used to suppress Barkhausen noise is a thin film made of Cu, A2, or the like.

Furthermore, the terminals 12-1 and 12-2 are connected to the same N as the sensing part IO.
Although it is preferable to use iFe, it is not limited to NjFe, and any soft magnetic material may be used.

In FIG. 1, the conductor layer 16 has its surface parallel to the plane containing the magnetoresistive element 14, and the conductor layer 16
6 is provided with a right-angled step in the middle.

The longitudinal direction of the conductor layer 16 is the terminal 12-1°12-2.
The conductor layer 16 is set perpendicular to the longitudinal direction of the conductor layer 16.
The middle part of the step is in a posture perpendicular to the plane containing the sensing section 10.

Furthermore, the middle part of the step of the conductor layer 16 is inserted in the vertical direction of the CC hanger 12-1, 12-2 in the vicinity of the sensing part 10, and the conductor layer 16 and the magnetoresistive element 14 are insulated. It is insulated by layer 60.

A current i for noise suppression is supplied to the conductor layer 16 from an external constant current source as shown in FIG. 1.12-2.

When a magnetic field H is applied from the outside in the direction of the easy magnetization axis EAO axis, IEEE MAG-16, No5P643-P6
45 (1980), the generation of magnetic domains is suppressed and Barkhausen noise is reduced.

Therefore, even if the length of the sensing section 10 is shortened to increase the recording density of the magnetic disk 50, it is possible to perform high-quality reproduction with low noise.

Note that if the noise suppression current i is supplied more than necessary, the sensitivity of the head decreases, so it is preferable to set the current value to a value sufficient for noise suppression.

In addition, when obtaining the magnetic field H for noise suppression by permanent magnetization,
Since it is difficult to stabilize this to an optimal value,
This tends to lead to a decrease in the sensitivity of the head.

In the embodiment shown in FIG. 3, layered protrusions 30-1, 30-2 are formed on the inner opposite sides of the terminals 12-1, 12-2, and their formation positions are as shown in the figure from the positions where they intersect with the conductor layer 16. It is considered to be the upper side.

Also in the embodiment shown in FIG.
-2 are similarly formed on the inner facing side of the terminals 12-1, 12-2, but in contrast to FIG. In FIG. 4, the protrusions 40-1 and 40-2 are superimposed.

However, the protrusions 40-1 and 40-2 are non-contact,
They and the protrusions 30-1, 30-2 are insulated with insulation N60.

Laminar projections 30-1.3 that reduce magnetic resistance in this way
0-2.40-1.40-2, it is possible to efficiently generate the magnetic field H in the embodiments of FIGS. 3 and 4.

As explained above, according to this embodiment, Barkhausen noise can be effectively suppressed even if the length of the sensing section 10 is shortened, so the track width of the magnetic disk 50 can be further narrowed to further increase its recording density. It is possible to increase it.

[Effects of the Invention] As explained above, according to the present invention, the generation of magnetic domains that cause Barkhausen noise can be suppressed by energizing, so the sensing part of the magnetoresistive element can be miniaturized and the recording of magnetic recording media can be improved. It becomes possible to increase the density.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the main parts of the first embodiment, Fig. 2 [21 is an explanatory diagram of the configuration of the first embodiment, Fig. 3 is an explanatory diagram of the configuration of the second embodiment, and Fig. 4 is an explanatory diagram of the configuration of the third embodiment. FIG. 5 and FIG. 6 are explanatory diagrams of the configuration of a conventional example. 10... Sensing section, 12-1. 12-2... Terminal, 14... Magnetoresistive element, 16... Conductor layer. 14 (Magnetoresistance effect element) Main part explanatory diagram of the first embodiment Figure 1 Figure 2 Part II! ! , Example configuration explanatory diagram “■ ―■ Configuration explanatory diagram of conventional example Fig. 5

Claims (1)

[Claims] A thin film magnetoresistive element in which terminals (12-1, 12-2) made of soft magnetic thin films are drawn out from both sides of a sensing portion (10) whose resistance value changes according to magnetism. (14), and a conductor layer (16) whose intermediate portion is inserted between the terminals (12-1, 12-2) in the vicinity of the sensing portion in an orientation perpendicular to the plane containing the sensing portion (10). A magnetoresistive head characterized by having.