JPS60107706A - Magnetic head - Google Patents

Abstract

PURPOSE:To suppress a false gap action by constituting a magnetic body so that its permeability approximates that of a core half body in the coupling part to the core half body and is increased toward the gap face side and making it difficult that jump of a magnetic flux occurs at a recording/reproducing time. CONSTITUTION:Production procedures of a head core are as follows; a core block 6 consisting of ferrite or the like is worked to a prescribed size, and a magnetic body 7 consisting of sendust or the like which should be a pole piece is coupled to the surface of the core block 6. For example, if the sputtering method is adopted as the coupling method, an external magnetic field where the permeability of materials of the core block 6 and that of the magnetic body 7 approximate each other or are approximately equal to each other is obtained preliminarily because the permeability of the magnetic body 7 can be changed by controlling the magnetic field of an external magnetic field generator belonging to a sputtering device, and the coupling part is sputtered, and the external magnetic field is changed in accordance with increase of the thickness of the magnetic body 7 to increase the permeability toward a gap 3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a magnetic head suitable for a magnetic recording medium with high coercive force.

[Prior art]

Conventionally, short-wavelength, high-density recording has been attempted by increasing the coercive force of magnetic recording media. Furthermore, head saturation during recording becomes a problem. For example, ferrite etc. are advantageous in terms of wear resistance, but have the disadvantage of low saturation magnetic flux density.
On the other hand, alloy-based magnetic materials such as sendust have a high saturation magnetic flux density, but have disadvantages in that they are inferior in wear resistance and high frequency characteristics.

From the perspective of compensating for the drawbacks of using these ferrite materials or metal materials alone and utilizing their mutual strengths, we have developed a method as shown in Figure 1 (
A composite head as shown in perspective views in (a), (s) and (c) has been devised. In the figure, 1°1' is a pair of half cores made of magnetic material such as ferrite, 2. 2'
are a pair of pole pieces made of a metal magnetic material such as sendust with high saturation density; 3 is a magnetic gap for recording and reproducing; 4 is a magnetic gap for recording and reproducing;
5° 5' indicates the winding window, and 5° 5' indicates the joint surface between the core half-hole 1.1' and the pole piece 2.2'.

In a magnetic head with such a structure, the pole piece 2 near the gap 3, where the magnetic flux density is highest during recording,
A highly saturated magnetic material is used only for the core halves 1 and 1', and a ferrite material with relatively low saturation but high magnetic permeability, such as ferrite, is used for the core halves 1 and 1', so both the recording and reproduction characteristics are sensitive. A high head can be obtained.

However, in such a magnetic head made of a composite of different materials, the bonding surfaces 5 and 5' of the different materials are parallel to the gap 3 in FIG. A small gap in time acts as a pseudo gap, degrading the S/N of the signal.

In order to improve these drawbacks, conventional methods have been to make the gap 3 and the dissimilar material joining surface 5° 5' non-parallel as shown in FIG. In this way, the joint surfaces 5, 5' of dissimilar materials have been made uneven. However, a state has not been reached in which the pseudo-gear effect can be sufficiently eliminated.

〔the purpose〕

The present invention aims to completely eliminate the pseudo gap effect in conventional magnetic heads as described above.

〔Example〕

The present invention will be explained below based on the drawings. FIG. 2 is a perspective view showing an embodiment of the magnetic head according to the present invention;
Components that are the same (equivalent) to those in FIG. 1 are indicated by the same reference numerals. That is, 1.1' is a pair of core half holes made of, for example, ferrite material, and 2, 2' is a pair of ball heaths that form the magnetic gap 3 for recording and reproduction, and is made of metal magnetic material such as sendust with high saturation magnetic flux density. Consists of materials. In this case, in order to avoid the pseudo gap effect at each joint surface 5°5' between the pole pieces 2, 2' and the core half-holes 1.1', the magnetic permeability of the core halves 1, 1' at these parts is reduced. and pole piece 2
, 2' are made close to or close to each other, and the magnetic permeability increases as it approaches the gap 3.

Next, the manufacturing procedure of the herad core for obtaining the above structure will be explained based on the perspective views of each process in FIGS. 3(a), (b), and (c). First, as shown in FIG. 3(A), a core block 6 made of ferrite or the like is processed to a predetermined size, and then the core block 60 is processed as shown in FIG. 3(B).
A magnetic material 7 such as sendust, which will become a pole piece, is bonded to the surface. In this coupling method, for example, when sputtering is used, the permeability of the magnetic body 7 can be changed by controlling the magnetic field of an external magnetic field generator attached to the sputtering device. Apply an external magnetic field in which the magnetic permeability and the magnetic permeability of the magnetic body 7 are approximately or almost equal, sputter the combined portion, and change the external magnetic field as the thickness of the magnetic body 7 increases to bring it closer to the cap 3. It is formed so that the magnetic permeability increases as the distance increases.

Next, the core block 6 combined as described above is formed into a chip shape as shown in FIG.
' and 2, 2', and these are joined by known means as shown in FIG.

As an example, the material of the core block 6 is ferrite,
When Sendust is used as the magnetic material 1, the intensity of the external magnetic field is changed from 20 Gauss to 60 Gauss when forming a Sendust layer with a thickness of 2 to 3 μm by sputtering (about 30 minutes).
In the case of Gaussian variation, a good magnetic head with very little pseudo gap effect was obtained.

Note that the external magnetic field strength may be changed continuously or in steps. Further, the layer of the magnetic material 7 may be formed of a plurality of layers of different kinds of magnetic materials so that the magnetic permeability approximates at the joint portion with the core block 6 and increases as the distance from this increases. Furthermore, the first
It may also be used in combination with the conventional joining method shown in Figures (B) and (C).

〔effect〕

As explained above, the magnetic head of the present invention is configured so that the magnetic permeability of the magnetic material serving as the pole piece and the half-core core are approximately equal to each other at the joint portion of the magnetic material serving as the pole piece, so that the magnetic flux is jumps are less likely to occur, and the pseudo gap effect that is unavoidable in the conventional example can be suppressed.

[Brief explanation of drawings]

1(a), (b), and (c) are perspective views of three examples of conventional magnetic heads, FIG. 2 is a perspective view of one embodiment of a magnetic head according to the present invention, and FIG. A), (B), and (C) are perspective views showing respective manufacturing steps of the herad core shown in FIG. 2. 1.1'... Core half 2.2'... Magnetic body 3... Magnetic gap 5 .5
′・・・・・・・・・Joint surface

Claims (1)

[Claims] In a magnetic head in which a magnetic material having a higher saturation magnetic flux density than the magnetic material constituting the core half is bonded to the gap surface side of the core half, and a magnetic gap is formed by the magnetic material, the magnetic material: A magnetic head characterized in that the magnetic permeability is similar to that of the core body at the joint portion with the core half-hole, and the magnetic permeability increases as it approaches the gap surface side.