JPH01192003A - Magnetic head - Google Patents

Abstract

PURPOSE:To prevent degradation in magnetic permeability and to prevent generation of exfoliation by partitioning a thin magnetic film consisting of 'Sendust(R)', etc., with a thin electrical insulating film in the direction perpendicular to a gap surface, thereby increasing electric resistance and reliving the internal stress of the magnetic film. CONSTITUTION:The thin 'Sendust(R)' film 2 having 3-6mum thickness is formed on the gap-facing surfaces of a pair of ferrite core half bodies 1, 1' and is partitioned by the thin electrical insulating film consisting of SiO2, etc. and having about 0.1-1mum thickness in the direction perpendicular to a gap spacer 4. As a result, the electric resistance in the direction parallel with the gap surface is several MOMEGA or above and since the generation of eddy current in this direction is suppressed, the degradation in the magnetic permeability is improved and the recording and reproducing efficiency in a high-frequency region is enhanced. Since the partition of the SiO2, etc., exists, the internal stress of the 'Sendust(R)', etc., is relieved and the trouble such as exfoliation is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) The present invention relates to a magnetic head used in 172-inch VTRs, 81a11 VTRs, and the like.

Conventionally, in order to perform high-density magnetic recording, recording and reproduction have been performed on a high coercive force magnetic recording medium using a magnetic head having a high saturation magnetic flux density core.

In other words, Utility Model Application Publication No. 169708/1983 and Japanese Patent Application Publication No. 1988-16970-
As stated in No. 133507, it is difficult to achieve a high saturation magnetic flux density core with a ferrite core. A so-called Metal-In-Gap mill head (MIG head) in which a thin alloy film such as sendust is disposed on the surface of a ferrite core facing the magnetic gap is used.

[L I ゛; However, Applied Magnetic Seminar 382 December 7,
8th ``Magnetic Recording High Track Density Recording'' If the core is formed only from an alloy such as sendust, the low electrical resistance of sendust causes eddy currents to easily flow, reducing magnetic permeability in the high frequency range. Recording/playback efficiency is poor.

Furthermore, even in the MIG head shown in FIGS. 2(a) and 2(b), a practical Sendust film that does not cause magnetic saturation of the core, although it is not as strong as the core formed only with Sendust described above. Since the thickness is 3 μm or more, it is inevitable that the magnetic permeability will decrease due to eddy currents in the high frequency range.

Furthermore, in MIG heads, since a magnetic thin film such as sendust is formed by sputtering or the like on a core made of ferrite or the like having a different coefficient of thermal expansion, problems such as the sendust thin film peeling off during the manufacturing process such as when butting core blocks occur. There was also the problem of poor yield.

In order to solve the above problems, the present invention replaces the magnetic thin film such as Sendust, which is disposed on the surface facing the gap of the MIG head, with an electrically insulating thin film such as 5102 in the direction perpendicular to the gap surface. By providing a partition, it has a means to significantly increase the electrical resistance of the Sendust thin film core part, and at the same time, it also serves as a means to relieve the internal stress of the magnetic film that occurs when a magnetic thin film such as Sendust is formed by sputtering etc. It is something that exists.

By partitioning a magnetic thin film such as Sendust with a wall of electrically insulating thin film such as 5102 in this way, the electrical resistance in the direction parallel to the gap plane becomes several MΩ or more, suppressing the generation of eddy currents in this direction. As a result, the decrease in magnetic permeability in the high frequency range is significantly improved, and the recording and reproducing efficiency in the high frequency range is increased.

Furthermore, the presence of partitions such as 510□ relieves the internal stress of magnetic thin films such as sendust formed by sputtering etc., reducing defects such as thin film peeling during the manufacturing process, and improving manufacturing yield.

footrest The present invention will be described in detail below based on the drawings.

FIG. 1 shows an embodiment of the present invention, in which a sendust thin film 2 with a thickness of 3 to 6 μm is arranged on the gap-opposing surfaces of two ferrite core halves, and this is coated with a thickness of 0.5 μm. 51 of about 1 to 1 μm
The thin film 3 of 02 partitions the gap spacer 4 at right angles.

5 is a molded glass that adheres the two ferrite core halves 1 together.

A coil 7 is wound through the winding window 6 to form a magnetic head.

FIGS. 3(a) to 3(e) show a method of manufacturing the magnetic head of the present invention.

As shown in FIG. 3(a), an electrically insulating thin film 9 of SiO2 or the like is formed to a thickness of about 3 to 10 μm by sputtering or the like on a substrate 8 that will become the ferrite core half, and as shown in FIG. 3(b), A 5 in 2 wall 3 having a thickness of about 0.1 to 1 μm is formed by photolithography and etching. On top of this, a magnetic thin film 10 of sendust or the like is formed by sputtering or the like, and the raised part 11 of the sendust is flattened by polishing as shown in FIG. Then, track grooves 129 and winding windows 6 are formed by cutting with a dicer or the like.

The core half body 13 made in this manner and another core half body 14 formed only of ferrite are butted together as shown in FIG.
Pour and weld at a temperature of ℃. After that, the separation line 15
The magnetic head of the present invention as shown in FIG. 1 is obtained by cutting with a dicer or the like along the lines.

FIG. 4 shows a second embodiment of the invention.

In this embodiment, both core halves 1,1' have a Sendust thin film core portion 2 separated by S s O 23.

FIG. 5 shows a third embodiment of the present invention.

In this embodiment, the ferrite core portion 1 of the second embodiment is entirely formed of a nonmagnetic substrate 16.

As described above, the magnetic head of the present invention uses an alloy thin film core such as Sendust that can achieve high saturation magnetic flux density, but does not suffer from the decrease in magnetic permeability due to eddy current, which is the drawback of the thin alloy film core. It is possible to achieve high performance and high manufacturing yield without generating the large internal stress that tends to occur in other products.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an embodiment of the invention, and FIGS. 4 and 5 are a perspective view of an embodiment of the invention. A perspective view showing the third embodiment, FIG. 3(a)
-(e) are perspective views showing the manufacturing method of the first embodiment of the present invention, and FIGS. 2(a) and 2(b) are perspective views of a conventional magnetic head. 1.1'...ferrite core half, 2...
... Thin film core part with high saturation magnetic flux density (Sendust), 3... Partition with electrically insulating thin film (510
2), 4... Gap spacer, 5... Molded glass, 6... Winding window, 7... φ coil. -I Q' in Fig. 2 (α) Fig. 2 (b) Fig. 3 <, a> Suspension 3 mark (b)! Figure 3 (C) Figure 3 (d) Figure 3 (e)

Claims (1)

[Claims] In a magnetic head in which a magnetic thin film with a high saturation magnetic flux density is disposed on one or both of the facing surfaces of a gap formed by two magnetic cores, the magnetic thin film is arranged in a direction perpendicular to the gap surface by an electrically insulating thin film. A magnetic head characterized by being partitioned.