JPH01189006A - Manufacture of magnetic head - Google Patents

Abstract

PURPOSE:To prevent the formation of a dummy gap, to improve a reproducing sound quality, and simultaneously, to execute a vertical recording by vacuum- forming a ferromagnetic thin metal film on the junction predetermined surface of a magnetic core substrate. CONSTITUTION:The junction predetermined surface of a long-scaled core block 8, in which a groove 10 for a junction, a groove 11 for a winding and a track groove 15 are cut-formed, is subjected to specular finishing, and a thin film is formed of a ferromagnetic metal material 16 such as a 'Sendust(R)' on the surface by means of a vacuum technique. An opposite block to be formed in the same way is glass-welded, and it is formed into a prescribed block for a head. As a result, since a glass layer with a proper thickness is provided between the ferromagnetic metal oxide of a ferrite and the ferromagnetic metal thin film 16, the dummy gap cannot be formed, and the reproduction with a good quality can be executed. When the thin film 16 is made into <=1mum, a magnetic flux B is generated in a vertical direction, and the vertical magnetic recording can be executed.

Description

[Detailed description of the invention] No. 1 This invention is a VTR that uses a high coercive force medium.

The present invention relates to core processing technology for magnetic heads used in devices such as R-DATs and FDDs, and particularly contributes to the production of magnetic helad cores made of composite magnetic materials of ferromagnetic metal oxide materials and ferromagnetic metal materials.

[Sub] E-item - Recording of information on magnetic recording media and reproducing information from magnetic recording media has become more and more difficult with the recent realization of high-density recording. It is used. On the other hand, as a magnetic head used for such high-density recording, MIG (Metal i
n Gap) There is something called H/D. This MIG head is for example rlEEEETRANSACTIONS O
N MACNETICS MAG-18, P114G~
! ! 481982J etc. are described in detail.

Therefore, the conventional structure of a MIG head used in a VTR or the like will be explained with reference to FIGS. 4 to 8. TSS (Tilted 5end Sput) in which ferrite single crystal or polycrystalline cores 3, 3 to which thin sendust alloy films 2, 2 are adhered are welded and butted together with glasses 4, 4 only on the periphery including the opposing surfaces of the magnetic gap 1.
erfng ) type core 5 is used in magnetic recording/reproducing devices such as VTRs. Examples of documents introducing the TSS type core include JP-A-59-142716. There are JP-A GO-182507, JP-A-H-234209, etc., and for parallel cores, IEEETRNASACTI
ONS ON MAGNETIC:S MAG-18,
There are P114Ei-1148°1982, etc.

By the way, when manufacturing such a TSS type core, it is made of a type of ceramic and has a considerably hard hardness ((approximately 58
0Hv) The core is made up of completely different materials: brittle single-crystal or polycrystalline ferrite, hard sendust alloy with considerable toughness, and glass as an adhesion protection material, so when cutting with a dicer etc. Another problem is that it tends to cause microcracks in the sendust thin film and glass, and it tends to cause chipping in ferrite.

Furthermore, in order to form the core halves in order to obtain such a TSS type core, the angle θ of the inclined surface 7 on which the sendust thin film 2 is attached is increased to reduce the amount of film deposited (
Moreover, in order to make the desired track width Tw sufficiently wide, it is necessary to significantly increase the precision of the polishing allowance dimension δ of the polished joint surface, which results in a contradiction that makes manufacturing difficult.

In addition, in the parallel type core 6, which is easier to manufacture than the TSS type core 5, the area near the interface between the sendust alloy films 2, 2 and the ferrite single crystal or polycrystalline cores 3, 3 is magnetically deteriorated. Since it tends to become non-magnetic and this interface is parallel to the magnetic gear knob 1, a pseudo gap is formed and sufficient characteristics cannot be obtained. Documents regarding this pseudo gap include Journal of the Japan Society of Applied Magnetics Vol. 1.11. No, 2,
1987 P105-108 etc.

The present invention has been proposed in view of the above-mentioned problems, and is made by forming a recess along the longitudinal direction of the end of the surface to be bonded of a long substrate of ferromagnetic metal oxide forming a magnetic core. a step of forming a groove; a step of applying a glass mold inside the concave groove of the substrate; a step of cutting and forming a plurality of tracks along the transverse direction of the substrate, leaving a predetermined track width; This method includes the steps of mirror-finishing the surface to be bonded of the substrate, and forming a thin ferromagnetic metal film in vacuum on the surface of the substrate to be bonded.

1 Dish According to the present invention, by carrying out the above steps, a glass layer of an appropriate thickness can be provided between the ferromagnetic metal oxide and the ferromagnetic metal thin film, and a so-called pseudo gap is not formed. It is possible to prevent inconvenient noise from occurring during recording to and reproduction from the medium. Furthermore, as shown in Figure 2, by making the thickness of the ferromagnetic metal thin film as thin as possible (1 μm or less), magnetic flux B is more likely to be generated perpendicularly to the recording medium, magnetizing the perpendicular magnetic recording medium. This makes perpendicular magnetic recording possible.

Practical Example - Hereinafter, one embodiment of the present invention will be described in detail based on the drawings.

First, long ferrite core blocks 8 and 9 as shown in FIG. 9 are prepared, and as shown in FIG.
A groove 11 for the winding portion is cut on the outer surface, and a concave groove 12, which is a feature of the present invention, is cut along the longitudinal direction of the inner surface of the elongated first core pro 8 in the part where the gap is to be formed. Cutting is performed. Further, a groove 13a for the winding portion is formed on the inner and outer surfaces of the elongated second core prong 9 along the elongated direction.

13b is cut.

Next, as shown in FIG. 11, which is a feature of the present invention, the groove 12 of the first long core block is filled with high melting point glass 14, and further, as shown in FIG. A plurality of track grooves 15,15.・
... is formed by cutting.

Then, as shown in FIG. The inner surfaces M, which are the surfaces to be joined, of the second fabric blocks 8 and 9 are mirror-finished, and as shown in FIG. Alternatively, a ferromagnetic metal material 16 such as permalloy is deposited.

After that, the long length 1. A non-magnetic thin film (not shown) such as 5io2 is deposited near the upper part of the inner surface of the second core block 8.9, which is the surface to be joined, and further, as shown in FIG. The inner surfaces of the second core blocks 8 and 9 are brought into contact with each other, and the core block 17 is obtained by heating and welding them together using the low melting point glass 14a. However, it goes without saying that during this heating and welding, it is necessary to use a low melting point glass that can be integrated at a temperature at which the high melting point glass 14 does not melt. Then, as shown in FIG. 1θ, the top end surface of the magnetized core block 17 is polished into a curved surface so as to have a predetermined gap depth, and the core block 17 is further sliced into pieces of a certain thickness to form core chips. Get 18. Thereafter, the core chip 18 is subjected to a winding operation to manufacture the magnetic head 19 shown in FIG. 1.

The embodiments described above are examples of magnetic heads used in VTRs, R-DATs, etc., but the present invention is also applicable to magnetic heads used in FDDs, etc.

Next, an embodiment of the present invention used in an FDD will be described with reference to FIGS. 18 to 23.

First, long ferrite blocks 19 and 20 as shown in FIG. 18 are prepared. However, 21 is a track groove, 2
2 is a V-groove, and 14a is a low-melting glass that fills the track groove 21 and V-groove 22. Further, 24 is a groove which is a feature of the present invention, and 14 is high melting point glass filling the groove 24. Next, as shown in FIG. 19, a ferromagnetic metal material 16 such as sendust, amorphous alloy, or permalloy is deposited on the surface of the ferrite block 20 to be joined. Thereafter, a non-magnetic thin film (not shown) such as SiO□ is deposited on the surface of the ferrite block 19.20 to be bonded, and as shown in FIG.
In step 4a, the core block 27 is obtained by heating and welding to integrate. Next, as shown in FIG. 21, the coil insertion groove 28
The core chip 29 shown in FIG. 23 is obtained by slicing the core chip into pieces of a certain thickness as shown in FIG. 22. after that,
As shown in FIG. 3, the core chip 29 is fitted with an insulating coated coil 30 wound in a predetermined number of turns, and a back core 31 is bonded. Although not shown, the core chip 2
Sliders are fixed to both sides of 9.

When the present invention is carried out, a glass layer of an appropriate thickness can always be provided between the ferromagnetic metal oxide and the ferromagnetic metal thin film, and so-called pseudo gaps are not formed. It is possible to provide a magnetic head that is highly reliable, of good quality, and, as shown in the embodiments, is also highly mass-producible. Furthermore, since the structure of the magnetic head embodying the present invention generates a magnetic flux B as shown in FIG. 2, it is easy to magnetize a perpendicular magnetic recording medium, and it can be employed in a perpendicular magnetic recording/reproducing device.

[Brief explanation of the drawing]

1 to 3 show examples of magnetic herad cores obtained by implementing the present invention, and FIG. 2 shows an enlarged cross-sectional view of a portion of the circle A near the magnetic gear in FIG. 1. Figures 4 to 8 show examples of conventional MIG heads, and Figures 5 and 8 show examples of conventional MIG heads.
The figure is an enlarged partial plan view showing the top end surface of a TSS type and parallel type MIG head. FIG. 6 is an explanatory diagram showing an example of manufacturing a TSS type MIG head. Figures 9 to 17 and Figures 18 to 23 are for VTR and R-DA, respectively.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of the present invention of a magnetic head such as a T-type magnetic head and a magnetic head such as an FDD. 1...Magnetic gap, 14...High melting point glass, 14a...Low melting point glass, 16...Ferromagnetic metal thin film, 19...・Magnetic core for VTR, R-DAT, etc. 29...Magnetic core for FDD, etc. 1st g da 2 π z 3 ] 4 Figure 7 Figure 82 9 Figure 610 Prisoner 1 Figure 14 20Z g 221 Broom 23 prisoners

Claims (1)

[Claims] On the bonding surface of a magnetic core substrate made of a ferromagnetic metal oxide,
In a method for manufacturing a magnetic head in which a magnetic gap is formed by abutting core halves formed with a ferromagnetic metal thin film against each other using vacuum thin film forming technology, a groove is formed in a portion where a gap is to be formed within a surface of the substrate to be bonded. a step of forming a glass mold inside the concave groove of the magnetic core substrate; a step of cutting and forming a plurality of track grooves on the magnetic core substrate leaving a predetermined track width; and a surface to be bonded of the magnetic core substrate. A method for manufacturing a magnetic head, comprising: mirror-finishing the magnetic core substrate; and forming a ferromagnetic metal thin film in vacuum on a surface of the magnetic core substrate to be bonded.