JPS6083209A - Magnetic head for vertical magnetic recording - Google Patents

Abstract

PURPOSE:To obtain a head which has no waving phenomenon in recording density characteristics and high reproduction sensitivity by specifying the magnetic permeability of the large-sectional-area magnetic pole of an asymmetrical annular head on the side of its medium facing surface. CONSTITUTION:When the magnetic permeability of the magnetic pole 32 is <=200, the waving phenomenon is reduced greatly, and when >=10, the obtained reproduction output is >=2 times as large as when a substrate 32 is made of a nonmagnetic body. Further, the height (t) of the magnetic substrate 32 made of Ni-ferrite, etc., having low saturation magnetic flux density and low magnetic permeability can be made larger than that of conventional head structure, and a magnetic field distribution is controlled freely, so reproduction sensitivity is high and waving phenomenon in recording density characteristics is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a magnetic head for perpendicular magnetic recording, and more particularly to a magnetic head with excellent recording and reproducing characteristics at image density.

[Background of the invention]

A conventional magnetic head for perpendicular magnetic recording is shown in FIG. 11 is a magnetic substrate, 12 is a coil, and 13 is a magnetic lake film. When this head performs recording and reproduction on a perpendicular magnetic recording medium, an etched portion 14 of a magnetic leg with a large magnetic pole cross section is formed.
However, since the recording density of No. 11 was damaged, the recording density characteristics were not very good, showing all the waving phenomenon. In order to prevent such deterioration of characteristics, proposals have been made such as rounding the etched portion 14 or, as shown in FIG. 2, a structure in which the etched portion 24 can be retracted from the surface facing the medium. In FIG. 2, 21 is a non-magnetic substrate, 22 is a main magnetic pole, 23 is a coil, and 24 is a sub magnetic pole. However, 1 in Figure 1
In addition, the structure shown in FIG. 2 has the drawback of low reproduction sensitivity.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a head that has no undulations in recording density characteristics due to the recording/reproducing characteristics at the edge portions, and has high readout sensitivity.

[Summary of the invention]

The present invention was made as a result of intensive studies aimed at developing a complete structure that magnetically eliminates edge portions. is the medium facing surface side, and the magnetic permeability is 10 or more and 200 or less, and more preferably, the saturation magnetic flux density of the low magnetic permeability part is smaller than the saturation magnetic flux density of the rear high magnetic permeability part, and still more preferably , the thickness of the low magnetic permeability portion is 2 μm or more and 1 μm or less.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be explained with reference to FIG. 31
Magnetic substrate consisting of Mn-Zn ferrite, Ni-Zn ferrite, etc., 31; l: Ni-ferrite, Mn-
Ferrite, Co-ferrite.

33UIi" e-8i-RLI, a low saturation magnetic flux density, low permeability magnetic substrate made of Li-ferrite, garnet, ferrox planar type ferrite, etc.

A magnetic thin film made of N1-Fe, Co-Zr-Nb, etc., 34 a gap layer made of Sioz, AtzOs, etc., 35 A7. The coil is made of CO, At-Cufi, etc., and 36 is an insulating layer made of polyimide resin, SiO2, etc.

FIG. 4 shows another embodiment. 41 is A-1203-Ti
Non-magnetic substrate made of C etc., 421dFe-81-Ru
, Fe-'ri, li"e-8i-At.

Co-F e , Co-Z r -W, Co-Z
r-N b.

43 is a ferromagnetic thin film consisting of S A02. AL2
A gap forming layer consisting of 0s etc., 44 is Co-Z
Magnetic thin film made of r-Nb etc., 45 u N i −
Fe.

Ni, Co-Cr, Co-Zr-Mo,
Low magnetic permeability, low saturation magnetic flux density magnetic thin film consisting of 46
47 is a coil made of Cu, 8U, etc., and 47 is an insulating layer made of polyimide resin, S'02, AI-x03, etc.

FIG. 5 shows yet another embodiment. 51 is A720s
A non-magnetic substrate consisting of etc., 52 is I, % e-81-
A magnetic A9 film made of Ru, pe-Ti, etc., 53 is a nonmagnetic layer made of A7203, etc., 54 is Ni-Fe.
, ferromagnetic thin film made of Co-Zr-W, etc., 55gN
i, low magnetic permeability consisting of Co-Zr-Nb, etc.
Low saturation magnetic flux density magnetic thin film, 56 is A4. The coil is made of Au or the like, and 57 is an insulating layer made of polyimide resin, 5iOz, or the like.

FIGS. 6 and 7 show yet another embodiment.

61.65, 71.71', 73.73' idMn
High permeability magnetic substrate made of -7,n ferrite, Ni-7,n ferrite, etc. 62,72.72' is made of low permeability such as Ni-ferrite, Mn-ferrite, ferrox planar! Magnetic substrate, 63°74.74' is a non-magnetic material such as glass, 64°75 is a magnetic pole such as a ferromagnetic thin film,
66.76ri coil winding.

According to the embodiment of the present invention described above, the high-permeability portion of the low magnetic permeability portion
Since the gt can be made larger than that of the conventional head structure and the magnetic field distribution can be controlled freely, the reproduction sensitivity is also high and the waviness phenomenon in the recording density characteristics can be reduced. That is, in FIG. 8, in the structure shown in FIG. 3, 31 is M n − with a saturation magnetic flux density of 0.5T and a magnetic permeability of 800.
Zn ferrite, 32'it'i20μm, composition,
N1-Zn ferrite%33 with magnetic permeability of 10, 190, 300 by changing heat treatment conditions and tip film thickness of 0,5
μm N1-pe, 34' (il-gap length 4 μm 5102.35-i16 turn At, 36 made of polyimide (4+1 layer), and tl zero or 3
Characteristics of conventional heads in which part 2 is made of non-magnetic glass and t (z 20 μm) are shown in f181, 82, 83., 84 and 85, respectively.If the magnetic permeability of part 32 is 200 or less, the waving phenomenon is significantly reduced, It can also be seen that if the magnetic permeability of the 32nd part is 10 or more, the reproduction output will be twice or more as compared to the case where the 32nd part is made of a non-magnetic material.

Figure 9 shows 41 all At20s-Ti with the structure of Figure 4.
C non-magnetic substrate, 42 is Fe-8 with saturation magnetic flux density 1.6T
i-Ru multilayer film, 43, film thickness 3 μm (7) S102.4
4 is the saturation magnetic flux density 1. OT, amorphous Co Z r N b with relative permeability 2001-, saturation magnetic flux density 0 at 45'
．． 8T, Co-Zr with relative permeability in the magnetic path direction of 180
-Mo at t(i715μm, 46(i78 turn A
7 coils, 47'1SiO2 head, σ et al.
In the structure shown in the figure, 51 is an A-403 substrate, 52 is an Fe-8i main pole with a saturation magnetic flux density of 1.8T, and 53 is a film thickness of 4μ.
Ni-Fe-Mo with a saturation magnetic flux density of 0.9 T and a relative magnetic permeability of 3000 in Az2o3,54 m.

55 is Co with a saturation magnetic flux density of 0.7T and a relative magnetic permeability of 100.
-Z r -N b tidl Oμrn, 561d8
The perpendicular recording and reproducing characteristics of the turn Cu coil and the head 57 are made of polyimide resin are 91. It is shown in L2. As described above, if the magnetic permeability of the medium facing surface side is 200 or less, the male output of the head is high, the recording density characteristics are monotonous, and no waving phenomenon is observed. However, in the structure shown in FIG. 4, the characteristics of the conventional head in which 45 and 44 are made of the same material as shown in 93 show that a waving phenomenon is observed. Furthermore, in a conventional head having the structure shown in the same figure, in which all 45 are not formed, no waving phenomenon is observed, as shown at 94, but it can be seen that the reproduction output is significantly reduced. Further, in the structure shown in Fig. 5, the characteristics when the material shown in 55 is C'o-Zr-Nb with a saturation magnetic flux density of 1.2 T and a relative magnetic permeability of 50 are shown in 95, but in part 54. A slight waving phenomenon was observed in response to the higher magnetic permeability of the 55 part compared to the other parts, and it is more desirable that the saturation magnetic flux density of the low permeability part is also lower than that of the high permeability part. I understand.

10 shows the structure shown in FIG. 6, 61.65i is Ni-Zn ferrite with an effective magnetic permeability of 500, 62 is Ni-ferrite with a magnetic permeability of 50 and t is 0.1, 63 is glass, %71.7 with the head when using 64iCo-Zr-Nb, f36i 50 turn coil, and the structure shown in Figure 7.
1', 73.73" (rMn-Zn ferrite, 72
．． 72” Mn7-I- with z magnetic permeability of 20 and t of 50 μm
Light, 75iFe-8i-RuO, 1μm and Ni
The characteristics of the head when using a multilayer film with Fe 0.005 μm, 74.74"i non-magnetic Z n-ferrite, and a 76i 50-turn coil are shown in f'L101 and 102, respectively. With the structure shown in FIG. When t k 1 rrryn or more, the regeneration efficiency decreases significantly, and when t is 1.3 streaks, as shown in 103, the regeneration efficiency is 1/6 of that when 1 is 0.1 M.
It became the following. In addition, if the structure shown in Fig. 7 is set to 42 μm or less, a waving phenomenon will be observed in the reproduction characteristics.
When t was 1.5 μm, as shown in 104, a waving phenomenon similar to that of the conventional head in which t was O was observed.

As mentioned above, the height t of the low magnetic permeability part is 2 μm or more%
It can be seen that if it is 1wn or less, the characteristics are significantly improved, especially compared to the conventional structure.

〔Effect of the invention〕

As described above in detail, according to the present invention, it is possible to obtain an entire head that has no waving phenomenon in its recording density characteristics and has high readout sensitivity.

[Brief explanation of the drawing]

FIGS. 1 and 2 are sectional views of a conventional head, FIGS. 3 to 7 are sectional views of a head according to an embodiment of the present invention, and FIGS. 8 to 10 are sectional views of a head of the present invention. FIG. 3 is a characteristic curve diagram showing a comparison of characteristics of conventional heads. 11.31, 65, 73.73'...magnetic substrate, 13
．． 22, 33, 42, 52, 64.75...main magnetic pole,
24,44. 54,61. ．． 71.71'... Sub magnetic pole, 32, 45, 55.62', 72.72'... Low permeability magnetic pole, 12, 23, 35, 46, 56° 66.7
6...Coil, 34, 36, 43, 47° No. 51 yen
] ) ＾ ＾ q Continued from Figure 1st page 0 Inventors: Hitoshi Nakamura, Higashi Koigakubo Research Institute, Kokubunji City [Co., Ltd.] Inventors: Katsura Hamakawa, Higashi Koigakubo Research Institute, Kokubunji City: 0 Inventors: Hiroshi Hamakawa, Kokubunji City, Higashi Koigakubo Laboratory Sei Kawa Kokubunji City Higashikoigakubo Research Institute 1-28 Hata Hitachi, Ltd. Naka 1-28 Hata Hitachi, Ltd. Naka 1-28 Hata Hitachi, Ltd. Intermediate Procedural Amendment Case Table of Contents, Showa 1982 Patent Application No. 19 (J7: (Name of No. 2 Invention) Relationship to the Case of Person Who Corrects Magnetic Heads for Perpendicular Magnetic Recording Patent Name of Applicant (510) Co., Ltd.

Claims (1)

[Claims] 1. In an asymmetric ring-shaped head in which one leg has a small cross-sectional area and the other leg has a large cross-sectional area, the magnetic pole with the larger cross-sectional area has a magnetic permeability in the magnetic path direction of 10 or more on the medium facing surface side. A magnetic head for perpendicular magnetic recording characterized by the following: 2. The magnetic head according to claim 1, wherein the saturation magnetic flux density of the low magnetic permeability portion is smaller than the saturation magnetic flux density of the rear high magnetic permeability portion. 3 The height of the low magnetic permeability part is 2 μm or more and 1 day or less