JPH0536017A - Magnetic head - Google Patents

Abstract

PURPOSE:To provide the magnetic head which does not crack the sealing glass sealing a pair of substrates during a stage for polishing the front faces of the head. CONSTITUTION:Magnetic materials 2 which consist of an amorphous alloy of a cobalt system or a nitrided alloy of a superstructure of the cobalt system are provided on he butt surfaces of a pair of the substrates 1. Gap glass 3 consisting of the laminated films of quartz glass or borosilicate glass and the sealing glass having <=600 deg.C working temp. is provided in the gap part of the magnetic materials 2 facing each other. A pair of the substrates 1 are sealed by the sealing glass 4 having <=600 deg.C working temp. The sealing glass in the gap glass melts and improves the sealing strength. The cracking of the magnetic head occurring in the cracking of the sealing glass in the stage for polishing the front surface of the head is thus suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head used in a magnetic recording / reproducing apparatus.

[0002]

2. Description of the Related Art In recent years, along with the miniaturization and high capacity of magnetic disk devices, there has been a strong demand for the development of a magnetic head which is compatible with a high coercive force medium and enables a high recording density. In order to meet this demand, a magnetic head using a cobalt-based amorphous alloy magnetic material or a cobalt-based superstructure nitride alloy magnetic material (cobalt-niobium-zircon-tantalum alloy film or this nitride film, hereinafter abbreviated as magnetic material) as a magnetic material. Has been developed. FIG. 1 shows a typical structure of a MIG (metal in gap) magnetic head using a ferrite substrate. A magnetic body 2 is formed by sputtering in a gap portion of a substrate 1 made of ferrite, the gap is filled with a gap glass 3, bonded by an amorphous sealing glass 4, and finally a coil (not shown). It is configured by winding.

In the above structure, the gap glass 3 has a high melting point such as quartz glass or borosilicate glass (for example, Pyrex manufactured by Iwaki Glass Co., Ltd.) so as to maintain a predetermined gap width even at the working temperature of the sealing glass 4. The glass was thinned by sputtering or vapor deposition.
Quartz glass or borosilicate glass is used as a target for sputtering. In the case of quartz glass, silicon dioxide (SiO ₂ ) may be used. This is because when silicon dioxide is made thin, it becomes amorphous and becomes equivalent to quartz glass. Therefore, when silicon dioxide is used as the gap glass, it has the same meaning as quartz glass.

FIG. 2 shows a typical structure of a laminated magnetic head using a nonmagnetic ceramic substrate. A track portion 6 in which a magnetic material and SiO ₂ are alternately laminated is provided on the side surface of a nonmagnetic ceramic substrate 5, and the substrate 5 is adhered to the substrate 7 by a crystallized glass 8. The gap is filled with the gap glass 3 as in FIG. 1, joined by the amorphous sealing glass 4, and finally wound with a coil (not shown).

Here, the working temperature of the amorphous sealing glass 4 must be 600 ° C. or lower so as not to impair the magnetic properties of the magnetic substance.

[0006]

However, in the above-mentioned conventional structure, since the gap glass 3 has a high melting point,
It does not serve to bond the substrates together by themselves. Therefore, the magnetic head using such a gap glass has a problem that the sealing glass is easily cracked during the head front surface polishing step.

An object of the present invention is to solve the above problems and to provide a magnetic head in which cracks do not occur in the sealing glass during the head front surface polishing step.

[0008]

In order to achieve the above object, the magnetic head of the present invention has a pair of substrates with opposing magnetic bodies made of a cobalt-based amorphous alloy or a cobalt-based superstructure nitride alloy on the abutting surfaces of the substrates. Providing a gap glass consisting of a laminated film of quartz glass or borosilicate glass and a sealing glass having a working temperature of 600 ° C or lower in the gap portion of the opposing magnetic body, and the working temperature of the pair of substrates is 600 ° C or lower. Other sealing glass is used for sealing.

[0009]

With the above-mentioned structure according to the present invention, the sealing glass in the gap is melted and the sealing strength is improved.

[0010]

EXAMPLES Examples of the present invention will be described below.

(Example 1) SiO ₂ = 5% by weight, B ₂
O ₃ = 9.7%, PbO = 82%, Al ₂ O ₃ = 3%, A
A glass with s ₂ O ₃ = 0.3% (working temperature 480 ° C.) was used as the sealing glass to manufacture an MIG magnetic head having the same configuration as in FIG. The gap glass was a laminated film of the sealing glass and borosilicate glass. The film thickness of each substrate was 0.03 μm and 0.12 μm.
Here, the magnetic substance is an amorphous alloy film made of cobalt-niobium-zircon-tantalum (for example, Yuji Omata et al.
National Technical Report, 31, 136 (1985)). As a comparative example, a MIG head in which the gap glass was borosilicate glass only (film thickness 0.15 μm) was also manufactured. When a destructive test was performed on each of the 10 chips of these two types of MIG heads using a material testing machine,
The gap glass, which was a laminated film of sealing glass and borosilicate glass, cracked at 110 g, whereas the comparative example, which only made borosilicate glass, broke at 50 g.

Further, polishing tape No. 2000 (Fuji Film Co., Ltd.) is used to finish the front surface of the MIG head into a conical shape.
16 of 50 pieces in the comparative example had cracks in the sealing glass, but only 2 pieces in the present example.

Although borosilicate glass was used in the above-mentioned examples, the same effect was obtained even in the case of quartz glass.

(Example 2) SiO ₂ = 22% in weight%,
B ₂ O ₃ = 4.9%, PbO = 66.5%, ZnO = 2
%, Al ₂ O ₃ = 1.5%, K ₂ O = 3% sealing glass (working temperature 600 ° C.) was used to manufacture the laminated magnetic head of FIG. The gap glass was a laminated film of the sealing glass and quartz glass. The film thickness of each substrate was 0.03 μm and 0.12 μm. Here, the magnetic substance is a superstructure nitride alloy film made of cobalt-niobium-zircon (for example, Hiroshi Sakaki et al., IEICE Technical Report MR-86-4 (1986), 87-14 (1).
987)).

As a comparative example, a laminated head was also manufactured in which the gap glass was only quartz glass (film thickness 0.15 μm). When each of the 10 chips of these two types of laminated heads was subjected to a destructive test using a material testing machine, the sample of this example cracked at 190 g, but the comparative example fractured at 90 g.

Further, when polishing was performed with a No. 2000 polishing tape (manufactured by Fuji Film Co., Ltd.) in order to finish the front surface of the head into a conical shape, 14 out of 50 cracks were generated in the sealing glass in the comparative example. In this example, no crack was generated.

Although quartz glass was used in the above embodiment, the same effect was obtained even in the case of borosilicate glass.

[0018]

As described above, according to the present invention, the gap glass is made of a laminated film of quartz glass or borosilicate glass and sealing glass having a working temperature of 600 ° C. or less, and sealed with the same sealing glass. As it is attached, the sealing glass in the gap will melt and improve the sealing strength,
It is possible to obtain a magnetic head in which cracks do not occur in the sealing glass during the head front surface polishing step.

[Brief description of drawings]

FIG. 1 is a perspective view of a MIG magnetic head.

FIG. 2 is a perspective view of a laminated magnetic head.

[Explanation of symbols]

1,5,7 substrate 2 magnetic material 3 gap glass 4 sealing glass 6 track section

Continued front page    (72) Inventor Akihiko Yoshida             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd.

Claims (2)

[Claims] 1. A pair of substrates are provided with opposing magnetic bodies made of a cobalt-based amorphous alloy or a cobalt-based superstructure nitride alloy on the abutting surfaces, and quartz glass or borosilicate glass is provided in the gap between the opposing magnetic bodies. Working temperature is 6
A magnetic head in which a gap glass made of a laminated film of glass for sealing at 00 ° C or lower is provided and the pair of substrates is sealed with another sealing glass at a working temperature of 600 ° C or lower. 2. The same magnetic core as one magnetic core consisting of a track portion in which magnetic materials composed of silicon oxide and a cobalt-based amorphous alloy or a cobalt-based superstructure nitride alloy are alternately laminated between a pair of substrates. In the gap portion of the abutting surface of the other magnetic core of the constitution, a gap glass composed of a laminated film of quartz glass or borosilicate glass and sealing glass having a working temperature of 600 ° C. or less is provided, and the pair of magnetic cores are set at the working temperature. A magnetic head sealed with another sealing glass whose temperature is 600 ° C or less.