JPS626420A - Thin film magnetic head - Google Patents

Abstract

PURPOSE:To prevent a decrease in yield due to bad insulation by forming a nonmagnetic material between the front part and the rear part of the lower magnetic yoke consisting of Ni-Zn ferrite and further providing a magneto- resistance effect element which is bonded respectively to the lower front magnetic yoke and the lower rear magnetic yoke. CONSTITUTION:The lower front magnetic yoke 12 and the lower rear magnetic yoke 13 both of which are formed with Ni-Zn ferrite are formed integrally with a nonmagnetic substrate 11 on both sides of a nonmagnetic groove 11a on the nonmagnetic substrate 11 through a bonding part 14. A nonmagnetic material 15 is embedded between the lower magnetic yokes 12 and 13 so that the surfaces on the opposite side of the nonmagnetic substrate 11 are allowed to lie in the same plane and a magneto-resistance effect (MR) element 4 consisting, for example, of Ni-Fe or Co-Ni is formed so that the parts of the lower magnetic yokes 12 and 13 are directly bonded on the surface. Accordingly, the lower magnetic yokes 12 and 13 and the MR element 4 are directly bonded without a magnetic gap in between. Consequently, a decrease in yield due to bad insulation can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a thin film magnetic head, and particularly to a yoke type magnetoresistive thin film magnetic head (hereinafter simply referred to as an MR head).

[Technical background of the invention]

2. Description of the Related Art As magnetic recording density has increased in recent years, MR heads manufactured using thin film technology have attracted attention. This yoke type MRI head was conventionally shown in Figures 3, 4, or 5.
As shown as a perspective view and a cross-sectional view in FIG. 6 and FIG.
→The structure is such that the resistance change due to the magnetization rotation of the MR1i element 4 is taken out through the output terminal 6. In order to provide such a function, it is necessary to guide sufficient magnetic flux to the MR element 4 and accurately extract the resistance change of the MR element 4. For this purpose, the MR element 4, the upper front magnetic yoke 5, and the upper rear magnetic eye 3 must be magnetically short-circuited and electrically insulated.

However, at present, the various types of magnetic thin films described above are formed by means such as sputtering 1 evaporation or coating), and only alloy magnetic films such as permalloy, sendust, or amorphous have been developed. , 5, it was necessary to provide an insulating film 7 such as SiO2 (see FIGS. 4 and 6). In FIGS. 3 to 6, 8 is a magnetic gear knob, 9 is a bias conductor, and 10 is a non-magnetic groove.

[Problems with background technology]

In the conventional thin film magnetic head as described above, MR
The thickness d of the insulating film 7 formed between the element 4 and the upper magnetic yokes 3 and 5 must be reduced to about 100 OA to 2000 λ in order to provide magnetic short-circuiting and electrical insulation. However, a sufficiently reliable insulating film with such a thickness has not yet been developed. Therefore, there is a problem in that the manufacturing yield deteriorates due to poor insulation.

Furthermore, due to the presence of this insulating film 7, a magnetic gap is created between the MR element 4 and the upper magnetic yokes 3 and 5, which reduces the effective magnetic permeability of the entire magnetic head, resulting in poor sensitivity. there were.

[Object of the Invention] The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide a highly sensitive yoke type MR head.

[Summary of the invention]

The present invention relates to a yoke type magnetoresistive thin film magnetic head that guides magnetic flux to a magnetoresistive element provided in the magnetic head and extracts changes in the magnetic field as changes in its resistance value. The magnetic yoke is separated into the front and rear parts, and a non-magnetic material is formed between them.
Furthermore, by providing magnetoresistive elements connected to each of the lower front magnetic yoke and the lower rear magnetic yoke, the intended purpose is achieved.
[Embodiment of the Invention] Hereinafter, an embodiment of a thin film magnetic head according to the present invention will be described with reference to the drawings.

1 and 2 are a perspective view and a sectional view, respectively, showing an embodiment of the present invention. In these figures, the same or equivalent parts as those of the conventional example shown in FIGS. 3 to 6 are denoted by the same reference numerals.A magnetic tape (not shown) is slid on a non-magnetic substrate 11 made of glass or the like. A non-magnetic groove 11a is formed approximately parallel to the sliding surface of the moving magnetic head, and N grooves 11a are formed on both sides of the non-magnetic groove 11a on the non-magnetic substrate 11, respectively.
A lower front magnetic yoke 12 and a lower rear magnetic yoke 13 made of i-Zn ferrite are integrally provided with the nonmagnetic substrate 11 via a bonding portion 14 formed by glass melt bonding or the like. A non-magnetic material 15 such as glass is embedded between these lower magnetic yokes 12 and 13 so that the surface opposite to the non-magnetic substrate 11 is the same surface, and the lower magnetic yokes 12 and 15 are embedded on these surfaces. An MR element 4 made of Ni--Fe or Co--Ni is formed by a known N film technique so that a part of the .13 is directly bonded. Both ends of this MR element 4 are coated with Cu and Au in order to extract the resistance change of the MR element 4.

A lead wire 6 made of M or the like is connected and formed.

Ni is placed on top of this MR element 4 via a magnetic gap 8.
An upper magnetic yoke 16 made of a material such as -Fe, Sendust or Co-Zn-N is laminated, and one end of this upper magnetic yoke 16 is directly connected to the lower rear magnetic yoke 13.
It is connected to the. In addition, this upper magnetic yoke 16 and MR
A conductor 9 made of Cu, Au, M, etc. is provided between the MR element 4 and the MR element 4 to apply a bias magnetic field. As mentioned above, a magnetic circuit is formed through the magnetic gap 8 with the lower surface magnetic yoke 12 → MR element 3 → lower rear magnetic yoke 13 → upper magnetic yoke 15, and by passing a current through the bias conductor 9. It is configured so that a bias magnetic field can be applied.

The operation of this embodiment configured as described above will be explained below. Specific resistance 1 in lower magnetic yoke 12.13
Since Ni-'In ferrite with ONIO Ωcm is used, the lower magnetic yoke 12, 13 and the MR element 4 can be directly bonded to each other without a magnetic gap therebetween. Therefore, the upper front magnetic yoke 5 and the upper b! The insulating film 7 between the rear magnetic yoke 3 and the MR element 4 is not required, and there is no reduction in yield due to poor insulation. Furthermore, even when the magnetic field from the recording medium is minute,
The magnetic flux can be focused on the MR element 4 through the upper magnetic yoke 15% and the lower magnetic yoke 12.13.

〔Effect of the invention〕

As described above, according to the present invention, the lower magnetic yoke is
It is made of fi-4t ferrite, and is separated into the front and rear parts and a part of it is directly connected to the M1% element, so it is possible to prevent a decrease in yield due to poor insulation.
A yoke type MR head with improved magnetic flux convergence efficiency and effective magnetic permeability and excellent wavelength characteristics can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the thin film magnetic head according to the present invention, and FIG. 2 is a sectional view taken along line A-Ag of the head shown in FIG. 1. FIGS. 3 and 5 show conventional thin film magnetic heads. Perspective view,
Figures 4 and 6 are B-BM of the head in Figure 3, respectively.
FIG. 6 is a sectional view and a sectional view taken along the line CC of the head in FIG. 5; 4...MR element 12...Lower front magnetic yoke 13
... Lower rear magnetic yoke 15 ... Non-magnetic agent Patent attorney Noriyuki Chika (and one other person)

Claims (1)

[Claims] N
A lower magnetic yoke made of i-Zn ferrite and separated into a front part and a rear part, a non-magnetic material formed between these separated lower magnetic yokes, and a lower front magnetic yoke and a lower rear magnetic yoke. A thin-film magnetic head characterized by comprising a magnetoresistive element bonded to each.