JPH0441414B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a magnetoresistive head (hereinafter referred to as MR head) used for magnetic recording in audio equipment, video tape recorders, computers, etc., and particularly relates to a yoke type head. Regarding the shape of the MR head.

[Technical background of the invention]

As magnetic recording density has increased in recent years, MR heads manufactured using thin film technology have been attracting attention. Conventionally, in a yoke type MR head, as shown in a perspective view in FIG. 3, a bias 3 is formed on a magnetic substrate 1 through an insulating film 2, and an MR element 5 is formed on the bias 3 through an insulating film 4. Then, a magnetic core 7 is further formed thereon via an insulating film 6 so as to cover one end of the MR element 5, or a groove is formed on the magnetic substrate 1 as shown in a perspective view in FIG. 8, and a glass 9 as an insulating film is formed in this groove 8.
A bias layer 3 is embedded through the insulating film 2 on top of the bias layer 3.
The MR element 5 was formed through an insulating film 6, and a magnetic core 7 was further formed thereon so as to cover both ends of the MR element 5.

[Problems with background technology]

In a conventional MR head configured as described above,
In the head having the shape shown in FIG. 3, since the bias 3 is placed between the MR element 5 and the magnetic substrate 1, the magnetic core 7 cannot be constructed in a flat shape, and the magnetic permeability decreases at the stepped portion. However, there was also the drawback that the manufacturing process was complicated. The head having the shape shown in FIG. 4 was developed to prevent a decrease in magnetic permeability, which is a drawback of the head shown in FIG. 9 and bias 3 had to be embedded, there was a problem that the magnetic path length could not be shortened.

[Purpose of the invention]

The present invention has been made in view of the above points, and an object of the present invention is to provide a yoke-type MR head that has a flat magnetic core and a short magnetic path length and is inexpensive to manufacture.

[Summary of the invention]

The present invention is a yoke type comprising an MR element formed on a magnetic substrate with an insulating film interposed therebetween, and a magnetic core forming a magnetic circuit on which a discontinuous portion is formed with an insulating film interposed therebetween. In the MR head,
Of the two magnetically permeable thin films forming the magnetic core disposed at both ends of the MR element in the width direction, the magnetically permeable thin film on the side not in contact with the recording medium is coated in a direction parallel to the longitudinal direction of the MR element. By providing a conductive lead wire and supplying current to the magnetically permeable thin film, the
A bias magnetic field is applied to the MR element.

According to the above configuration, a bias magnetic field can be obtained without forming a conventional bias, so the magnetic core is flat and the permeability is high, and the magnetic path is shortened, which improves the characteristics and reduces manufacturing costs. Become.

[Embodiments of the invention]

An embodiment of the MR head according to the present invention will be described below with reference to the drawings.

Fig. 1 is a perspective view showing one embodiment of the present invention;
The figure is a sectional view taken along the line AA in FIG. 1. Note that parts that are the same or equivalent to those of the conventional example shown in FIGS. 3 and 4 are given the same reference numerals. A glass groove 10 is formed in a magnetic substrate 1 made of ferrite or the like, and a glass 11 for melt bonding is fixed to the glass groove 10 by means such as sputtering or vapor deposition. An insulating film 2 made of SiO ₂ or the like is formed on the magnetic substrate 1, and an MR element 5 is formed above the glass groove 10 via this insulating film 2. Lead wires 12 are connected to both ends of this MR element 5, and are similarly formed on the insulating film 2. These MR elements 5 and lead wires 12 are covered with an insulating film 6. At both ends of the MR element 5 in the width direction, there are two magnetically permeable thin films 7 made of permalloy or the like that form a magnetic core.
a and 7b are formed facing each other with the insulating film 6 interposed therebetween, and a discontinuous portion 7c is provided between them. Of these magnetically permeable thin films 7a and 7b, the front magnetically permeable thin film 7a in contact with the tape sliding surface 1a of the MR head and the rear magnetically permeable thin film 7b on the opposite side have both end faces perpendicular to the longitudinal direction of the MR element 5. , are connected to lead wires 13, and are formed substantially parallel to the lead wires 12 with the insulating film 6 interposed therebetween. The entire MR head constructed in this manner is covered with an insulating layer (not shown), and a holder (not shown) is bonded thereon. Note that the above-mentioned insulating layer 2,
6, MR element 5, thin films 7a, 7b, lead wire 1
2 and 13 are formed by various known ring fly techniques.

According to this embodiment configured as described above, an appropriate bias magnetic field can be applied to the MR element 5 by passing a current through the rear magnetically permeable thin film 7b forming the rear magnetic core through the lead wire 13. .
This eliminates the need for conventional biasing, makes the magnetic core flat, increases permeability, and shortens the magnetic path, improving the properties of the MR head, making the manufacturing process much easier and cheaper.

〔Effect of the invention〕

As mentioned above, according to the present invention, a bias magnetic field is generated by passing a current through the rear magnetic core of the magnetic cores constituting the MR head, so the conventional bias is unnecessary and an inexpensive device with good characteristics is produced. It is possible to obtain a good MR head.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of the MR head according to the present invention, FIG. 2 is a sectional view taken along line A-A in FIG.
3 and 4 are partially sectional perspective views showing a conventional yoke type MR head. 1... Magnetic substrate, 2, 4, 6... Insulating film, 3
... Bias, 5 ... MR element, 7 ... Magnetic core, 7a ... Front magnetically permeable thin film, 7b ... Rear magnetically permeable thin film, 12, 13 ... Lead wire.

Claims (1)

[Claims] 1 A yoke comprising a magnetoresistive element formed on a magnetic substrate with an insulating film interposed therebetween, and a magnetic core forming a magnetic circuit in which a discontinuous portion is formed on the magnetoresistive element with an insulating film interposed therebetween. In the type magnetoresistive head, a lead wire is attached to the magnetically permeable thin film on the side not in contact with the recording medium, of the two magnetically permeable thin films forming the magnetic core disposed at both widthwise ends of the magnetoresistive element. A magnetoresistive head, characterized in that a bias magnetic field is applied to the magnetoresistive element by passing current through the magnetically permeable thin film in a direction parallel to the longitudinal direction of the magnetoresistive element.