JPS62248116A - Manufacture of magnetic head - Google Patents

Abstract

PURPOSE:To obtain a head with high quality by forming groove to one face of a ferrite wafer, adhering the magnetic substance by etching processing and incorporating a couple of wafers so as to compensate the deficiency in the saturated magnetic flux density without losing the recording/reproducing characteristic. CONSTITUTION:The surface of ferrite cores 10, 11 with respect to magnetic substances 12, 13 has ruggedness in the track width direction of the head and does not have a plane substantially in parallel with the operating gap constituting face of the head. Further, the highs and lows of adhered faces 16, 17 are opposed to each other respectively. The ferrite water 20 is cut out from an ingot at the core adhering face, slots 21a, 21b in parallel are cut from one face by using a dicing blade, the surface of the wafer is subject to etching processing and the magnetic substance is connected to the wafer 20. In such a case, the mixture ratio of the ferrite is increased, the ratio of alloy magnetic material is increased gradually and only the alloy magnetic material is used finally. then the surface of the magnetic substance is subject to mirror surface processing to incorporate the couple and a head chip is obtained through the slicing process.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a magnetic head suitable for use with magnetic media having a large coercive force, such as alloy tape.

Alloy tape has an extremely high coercive force (approximately 1000 oersted, which is more than twice that of conventional chrome tape). In order to effectively utilize such a large coercive force, the magnetic head must have a sufficiently large saturation magnetic flux density. Ferrite has an advantage in wear resistance, but has the disadvantage of a low saturation magnetic flux density.On the other hand, alloy magnetic materials such as Sendust (registered trademark) have a high saturation magnetic flux density, but have poor wear resistance and high frequency It is inferior in terms of characteristics. Therefore, by combining these two types of magnetic materials, for example, a magnetic material having a higher saturation magnetic flux density than that of the ferrite core material is bonded to each working gap forming surface of a pair of ferrite cores. It is useful to configure the head.

However, when dissimilar magnetic materials are bonded in this way, the gap between the bonded surfaces acts as a pseudo working gap, impairing recording characteristics. In other words, in general, when bonding a different type of material to the core surface of a magnetic herad core by vapor deposition or the like, the core surface is usually polished beforehand to remove the strained layer. The coupling plane is parallel to the plane constituting the working gap of the magnetic head, which acts as a pseudo gap. Figure 1 shows a perspective view of the main parts of a conventional magnet core.In the figure, (1) (21 is a ferrite core, +31 (4)
1 is an alloy magnetic material such as sendust, (5j is an actuation cap filled with glass as a bonding material. Here, each bonding surface +61 between the ferrite core and the alloy magnetic material (71 is the actuation gap +51 and its They are parallel to each other and form a so-called pseudo cap.If the tape is running in the direction of arrow (8), the pseudo cap (6) on the tape entry side does not have much influence during recording, but the pseudo cap (6) on the exit side An unnecessary signal is recorded in the gap (7), and during reproduction, there is a possibility that this unnecessary signal is reproduced by both pseudo gaps f6++71.

In order to eliminate such drawbacks, the present invention provides a magnetic head in which the surface shape of the ferrite core relative to the magnetic material is configured so that it does not have a flat surface that is substantially parallel to the plane that constitutes the working gap of the magnetic head. The manufacturing method includes a step of cutting a ferrite wafer from an ingot or foam, a step of grinding and forming sawtooth grooves on one side of the ferrite wafer, a step of etching the grooved surface, and a step of etching the etched surface. A step of bonding the magnetic material to a surface, a step of mirror-finishing the surface of the magnetic material, a step of integrating a pair of mirror-finished ferrite wafers with a bonding material, and slicing the integrated product. The magnetic head is manufactured by the following steps.

FIG. 2 shows a perspective view of the main parts of the magnetic head manufactured according to the present invention, where utmnn is a ferrite core,
α2α3 is a magnetic material containing an alloy magnetic material such as Sendust, which has a higher saturation magnetic flux density than ferrite, and α2 is an operating cap filled with glass. Ferrite core (1G (u
As exaggerated in the figure, the surface shape of the magnetic material (13) of n is uneven in the track width direction (arrow (151)) of the magnetic head.

It is configured so that it does not have a plane that is substantially parallel to the surface that constitutes the operating cap of the magnetic head. The angles (α) and (β) in the figure are preferably 10' or more. Note that the upper limit of this angle is limited by the binding force of the magnetic material. In addition, each coupling surface Gl'1l (1710 peaks and valleys are arranged to face each other. In this magnetic head, the coupling surface between the ferrite core and the magnetic material is not parallel to the working gap, Since the so-called azimuth loss is utilized, unnecessary signals recorded on the coupling surface Cl61 during recording are not reproduced on the coupling surface a1)1 and the working gap a4 during reproduction, especially when the handling frequency is high. Sometimes this tendency is significant. Although the possibility of reproduction at the coupling surface αη is the same as that shown in FIG. 1, the overall proportion of unnecessary signals that are reproduced can be extremely reduced compared to the conventional method. Note that α& is the tape running direction.

Next, a method of processing the bonding surface of the ferrite core in the present invention will be explained. First, a ferrite wafer (20) as shown in Fig. M3 (a) is cut out from an ingot.

Next, parallel a (21a 021 b)... is ground on one surface of this wafer using a dicing blade.

The groove pitch (P) and M depth D) are each 1, for example.
)00)t is set to about 10 μm. Next, the surface of the wafer provided with the grooves is etched using hydrochloric acid or the like. This is to remove processing distortions and microcracks during wafer production, and is an alternative to the conventional surface polishing process, and the depth of the etching is 10 m or more. ing.

Plasma spraying, for example, can be used as a method for bonding the magnetic material to the thus obtained ferrite wafer K as shown in FIG. 3(b)K. This is a method of bonding the material to be sprayed in the form of plasma, but in order to increase the bonding force and increase the proportion of the alloy magnetic material in the working gap, K is used as the magnetic material to be sprayed using ferrite and alloy magnetic material. At first, the mixing ratio of ferrite is increased, and then the proportion of alloy magnetic material is gradually increased, until finally only the alloy magnetic material is bonded to the ferrite wafer. Good. Next, as in the usual manufacturing method, the surface of the magnetic material is mirror-finished, the pair is combined with a bonding material such as glass, and a head chip is obtained through a process such as slicing.

As described above, in the magnetic head manufactured according to the present invention, when a magnetic material containing an alloy-based magnetic material having a higher saturation magnetic flux density than the ferrite core is coupled to the ferrite core, the coupling surface forms a pseudo cap.1. As if not.

The shape of the coupling surface is such that it does not have a plane parallel to the working gap structure plane of the magnetic head in the track width direction of the magnetic head, so the features of the ferrite core can be achieved without impairing the recording/reproducing characteristics. Take advantage of it and its drawbacks r! It can compensate for the lack of sum magnetic flux density, and is particularly useful for so-called alloy tapes that have a large coercive force and a large residual magnetic flux density.

In order to prevent the surface of the ferrite core from facing the magnetic body from having a plane parallel to the surface constituting the working gap of the magnetic head, it is made into an uneven shape as in the above embodiment. 6 compared to the case where the operating gap is at a predetermined angle linearly (without uneven shape).
This is effective for small-sized video heads, which has the advantage of being able to reduce the thickness of the magnetic body relatively uniformly by one level.

1. In the magnetic head manufacturing method of the present invention, etching is performed after sawtooth groove processing, so processing distortions and microcracks on the ferrite wafer are suitably removed, and the magnetic material is then removed from the ferrite wafer. The bonding force in the bonding is increased, and peeling of the magnetic layer and increase in magnetic resistance at the bonding surface can be prevented, and a high quality magnetic head can be obtained.

[Brief explanation of drawings]

FIG. 1 is a perspective view of essential parts of a conventional magnetic head. FIG. 2 is a perspective view of essential parts of the magnetic head of the present invention. FIGS. 3A and 3B are perspective views of the ferrite wafer before and after groove processing. αI(Iυ...1 pair of ferrite cores, (12(1
3...Magnetic material, (161αη...Coupling surface of core with unevenness.

Claims (1)

[Claims] (1) A magnetic material having a higher saturation magnetic flux density than the ferrite core material is bonded to each working gap forming surface of a pair of opposing ferrite cores, and the shape of the surface of the ferrite core relative to the magnetic material is magnetically A method of manufacturing a magnetic head configured to have no plane substantially parallel to a surface constituting an operating gap of the head, the method includes the steps of: cutting a ferrite wafer from an ingot; a step of forming a groove by grinding, a step of etching the grooved surface, and a step of bonding the magnetic material to the etched surface;
A method for manufacturing a magnetic head comprising the steps of mirror-finishing the surface of the magnetic material, integrating a pair of mirror-finished ferrite wafers with a bonding material, and slicing the integrated product.