JPH0191308A - Magnetic head - Google Patents

Abstract

PURPOSE:To manufacture a head, which is highly precise in its gap length and is stable in its characteristic, at good yield by constituting a magnetic circuit by piling the gap member of prescribed film thickness and a soft magnetic thin film on the gap forming surface of a core half body. CONSTITUTION:A first soft magnetic thin film 21 is formed on a ferrite bulk material to be the core half body 1. Next, a track mold groove is worked, and after filling up track mold glass 6,a surface is ground. Further, after non- magnetic material 4 is embedded so as to cover the side of the gap forming surface except a winding hole 5, the gap forming surface is ground. The gap member 3 of the prescribed thickness is formed on it, and is piled on the member 3, and a second soft magnetic thin film 2 is formed. After a holding member block is bonded to it with glass, it is cut, and a magnetic head chip is obtained. Accordingly, since gap forming processing is not pasting-together, the yield is high, and the head can be manufactured at a low price.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic head suitable for high-density magnetic recording and reproducing devices such as VTRs and digital audio.

BACKGROUND OF THE INVENTION Conventionally, bulk magnetic materials such as ferrite or sendust have been used in magnetic heads used in VTRs, digital audio, and the like. The magnetic gap of a head made of such a material is formed by bonding together a pair of core halves that have been subjected to shape processing such as track processing and winding groove processing to the above-mentioned material.

For this purpose, the gap forming surfaces of the pair of core halves are polished with high precision, a gap member having a desired thickness is formed by a spattering method, and then glass or the like is used as an adhesive and melted by heating. In addition, in recording and reproducing systems using high coercive force media such as metal magnetic powder, heads made of composite materials are also used in which a metal magnetic thin film is formed near the magnetic gear to improve recording efficiency. , shape, etc. are not essentially different from conventional ferrite heads.

In recent years, with the development of high-density magnetic recording, there has been a demand for magnetic heads with extremely small magnetic gears and 7-pin length. For example, digital audio tape (DAT)
In this case, a thickness of 0.3 μm or less is required. In the conventional gap forming method by bonding, in order to obtain a precise gap length, it is necessary to check not only the finishing accuracy of the gap forming surface but also the thermal expansion difference between different materials such as glass, distortion due to processing, etc. It is necessary to reduce the warpage of the core halves, which requires advanced polishing techniques. However, there is a limit to this technique, and if the gap length is narrower than this, the desired head characteristics cannot be stably obtained due to variations in the gap length, resulting in a decrease in yield.

Problems to be Solved by the Invention In a magnetic head for high-density magnetic recording, narrowing the gap is essential. For heads with such narrow gap lengths, with the above-mentioned conventional structure and manufacturing method, the process of forming the magnetic gap is the process that reduces the yield the most, and the low yield of gap accuracy causes costs. This is a major cause of the high Furthermore, in a recording/reproducing system using a high coercive force medium such as metal magnetic powder, it is necessary to form a soft magnetic thin film with a high saturation magnetic flux density near the magnetic gap to improve recording efficiency.

Means for Solving the Problems The present invention solves the above problems by providing a core half which is mainly made of oxide magnetic material, has a first soft magnetic thin film formed near its gear, and is provided with a winding hole. This problem is attempted to be solved by forming a gap member of a predetermined thickness and a soft magnetic thin film overlappingly on the gap forming surface of the body to form a magnetic circuit.

Functional gap formation is not dependent on the conventional method of lamination,
Since it uses a method of forming thin films in layers, it is possible to manufacture a magnetic head with high gap length accuracy and stable characteristics at a high yield and at low cost.

In addition, since a soft magnetic thin film with a high saturation magnetic flux density is formed near the magnetic gap, the recording efficiency is high and it is fully compatible with high coercive force media.

EXAMPLE Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

Embodiment 1 FIG. 1 is a perspective view showing the structure of a core chip of a magnetic head of the present invention. The magnetic circuit is composed of a core half 1 provided with a winding hole 5, a first soft magnetic thin film 21 formed near the gap thereof, and a second soft magnetic thin film 2 sandwiching the gap member 3. There is. The winding groove 8 is embedded in the non-magnetic material 4 so as to leave the winding hole 5 and cover the gap forming surface side of the gap member on the substantially flat gap forming surface of the core half. , a second soft magnetic thin film is formed in an overlapping manner.

FIG. 2 is a process diagram showing the method for manufacturing the magnetic head of the present invention. As shown in FIG. 2(a), a first soft magnetic thin film 21 (in this example, a Fe-Al-3i alloy thin film) is formed by a splatter method on a ferrite bulk material 1 of a predetermined size that is to become a core half. form). At this time, etching the sputtered surface of the ferrite bulk material to form an appropriate angle with the gap surface is effective for avoiding the influence of the pseudo gap, but this is omitted in this embodiment. Trunk mold groove 7 further defines the track width.
Fig. 2 (bl) shows the machining of 6n in the track mold. Next, Fig. 2 (C) shows that the track mold groove is filled with glass 6n by heating and melting at 750°C, and then the surface is ground. After processing the winding groove 8, as shown in FIG. 2(e), a non-magnetic material 4 (in this example, glass is heated After embedding the gap forming surface 9 (used by melting), the gap forming surface 9 is polished.Furthermore, a predetermined thickness (0 in this example) is embedded onto the gear knob forming surface.
．． After forming a 5 in 2 piece as a grab member 3 (3 μm) by sputtering, a soft magnetic thin film (in this example, an alloy thin film mainly composed of Fe-Al-3i was used) 2 constituting one magnetic circuit was sputtered. FIG. 2(f) is formed by overlapping the gap member. In this way, the magnetic heel cloth 10 is manufactured.

Furthermore, as shown in FIG. 2(g), after gluing a non-magnetic holding material block 11 to the magnetic hend block (in this example, glass was heated and melted at 500° C. as the adhesive). The magnetic head tip shown in FIG. 1 can be obtained by cutting at the position shown by the broken line in FIG. 1(h). The magnetic hent chip thus obtained is further bonded to a base and wound with wire for practical use.

The magnetic head manufactured as described above has a high yield (it can be manufactured at low cost) because the gear forming process is formed by layering thin films without using the conventional bonding process. Furthermore, since a metal magnetic alloy is used in the vicinity of the gap, the recording characteristics are good, and the recording characteristics are also excellent for high-density recording media such as Ba ferrite and metal magnetic powder.

Example 2 Instead of the alloy thin film mainly composed of Fe-Al-3t used in Example 1, Co was used as the first and second B soft magnetic thin films.
Amorphous alloy RTIQ, Fe-N+ whose main component is
A similar magnetic head can be obtained using any of the alloy thin films containing as the main component. When an amorphous alloy thin film containing Co as a main component was used as the soft magnetic thin film, glass whose working temperature was 500'C or less was used to avoid crystallization. Therefore, the magnetic head manufactured in the same manner as in Example 1 was good as in Example 1.

Example 3 As in Example 1, an alloy thin film mainly composed of Fe-Al-3t was used as the first soft magnetic thin film, and an Fe-C (8 at%) compound thin film was used as the second soft magnetic thin film 2. A magnetic head was manufactured using the same steps as in Example 1. The obtained magnetic head was as good as Example 1.2. In addition, as the second soft magnetic thin film 2, N (7 at%), P (1
Magnetic heads fabricated using compound thin films containing 0 at%) were also good as in the above-mentioned examples.

Effects of the Invention As described above, the magnetic head of the present invention is mainly made of an oxide magnetic material, and the first soft magnetic thin film is formed in the vicinity of the gear, and the gap between the core halves in which the winding holes are provided. Since the gap can be formed by stacking the thin films in the order of gap member and soft magnetic thin film on the forming surface, the characteristics near the gear are significantly better and stable compared to the conventional bonding method, and it is simple. Figure 1 is a perspective view showing the structure of the magnetic head of the present invention, and Figure 2 shows a method of manufacturing the head in an embodiment of the present invention. It is a process diagram for explaining.

DESCRIPTION OF SYMBOLS 1...Core half, 2...Second soft magnetic thin film, 3...Gap member, 4...Nonmagnetic material, 5... ... Winding hole, 6 ... Track mold glass, 7 ... Track groove, 8.
... Winding groove, 9 ... Gap forming surface, 1
0... Magnetic head block, 11...
Holding material block, 21...first soft magnetic thin film.

Name of agent: Patent attorney Toshio Nakao (1 person) Figure 1 Figure 2 Ward 9 Mound 14 d

Claims (4)

[Claims] (1) A first soft magnetic thin film mainly composed of oxide magnetic material is formed near the gap, and a gap member with a predetermined film thickness is placed on the gap forming surface of the core half where the winding hole is provided. , and a second soft magnetic thin film are stacked to form a magnetic circuit. (2) A patent characterized in that the winding hole provided in the core half is formed by filling a non-magnetic material so as to leave the winding hole in the winding groove and cover the gap forming surface side. A magnetic head according to claim (1). (3) Either an amorphous alloy thin film mainly composed of Co, an alloy thin film mainly composed of Fe-Al-Si, or an alloy thin film mainly composed of Fe-Ni is used as the first or second soft magnetic thin film. A magnetic head according to any one of claims (1) and (2), characterized in that the magnetic head uses: (4) Claim (1) characterized in that the first or second soft magnetic thin film is a compound thin film mainly composed of Fe and containing at least one of C, N, and P. The magnetic head according to any one of item (2) and (2).