JPH01106305A - Manufacture of electromagnetic converter for recording and/or reproducing - Google Patents

Abstract

PURPOSE:To effectively remove noise and to improve workability and operability by erasing processing the processing surface of a bulk magnetic body processed in a prescribed shape in vacuum and thereafter, sticking another magnetic body to the processing surface. CONSTITUTION:A bulk 21 composed of an Mn-Zn ferrite single crystal is segmented and a groove 30 for winding is formed on it. Next, the bulk 21 is provided a sputtering device 31 and while a prescribed area including the groove 30 is covered with a mask material, the vacuum is made in the device. Thereafter, an Ar gas is contained, the whole is made into a prescribed pressure, discharging occurs at the section of a counter electrode 32 and a magnetic characteristic deterioration layer to remain on a surface 34 is sufficiently removed by etching. A high magnetic permeability layer 32 is grown to a prescribed thickness on a bulk surface 34. Next, on the surface of the high magnetic permeability layer 32, an SiO2 film 35 is thinly grown. Next, a pair of the bulks 21 of the same shape is faced, a welded glass rod 36 is arranged between them and joining and integration are completely executed by the welding.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a method of manufacturing an electromagnetic transducer for recording and/or reproducing, such as a magnetic head.

In conventional magnetic heads, a magnetic gap is provided in a core made of a soft magnetic material, and a leakage magnetic field is formed from the magnetic gap by a current flowing through a coil wound around the core. Recording is performed on the medium in accordance with the current flowing through the coil, or reproduction is performed by the reverse method.

In recent years, a Talarad type magnetic head has been proposed in which a layer made of a high magnetic permeability material such as sendust is provided on the magnetic gap forming surface of a ferrite core body to improve magnetic properties. FIG. 6 and FIG. 7 show an example of the core body 11a, ll made of Mn-Zn ferrite.
b, an X-shaped layer 12 of high magnetic permeability material (for example Sendust) is formed, and a magnetic gap 13 is formed on its centerline. 19 on both sides of the magnetic gap 13 are reinforcing glasses.

In such a magnetic head, the boundary 10 between the high magnetic permeability layer 12 and the core bodies 11a, llb is inclined at an angle θ (azimuth angle) with respect to the magnetic gap 13. Such a slope has the effect of reducing noise due to pseudogaps (unwanted stray magnetic fields created at boundaries between different materials). This undesirable decrease in leakage magnetic field output is expressed by the following equation.

πTW tanθ λ λ (However, TW is the track width, λ is the recording wavelength, and θ is the above-mentioned inclination angle.) Therefore, the larger θ is, the less undesirable noise due to the pseudo gap is.

C.3 Background of the Invention However, upon further study by the present inventor, it was found that even if the azimuth angle θ is set as described above, noise still exists at a certain level.

This is because when mechanically processed into the shapes shown in FIGS. 6 and 7, distortion remains on the processed surface 14 of the high magnetic permeability layer 12, and a layer with altered magnetic properties exists. It seems that this is for the purpose.

Therefore, in order to remove such a deteriorated layer, the above-mentioned surface 14
It is conceivable to etch the surface with a chemical agent such as H3PO4 and grow a high magnetic permeability material on the etched surface by sputtering or the like. However, such a method cannot sufficiently remove the above-mentioned deteriorated layer and still cannot eliminate noise during recording/reproduction. Moreover, since the chemical etching and the subsequent sputtering are essentially different and completely different processes, there is no continuity in the process and it is not easy to implement them. In addition, even if the active surface is obtained by etching, it must be washed with pure water after etching, which causes unnecessary substances to adhere to the active surface and prevents good adhesion with high magnetic permeability materials. It has no gender. Therefore, processing of the sendust surface such as polishing is not possible, and there are restrictions on head processing, making it impossible to simplify head processing and resulting in poor yield.

20 OBJECTS OF THE INVENTION An object of the present invention is to provide a manufacturing method that can easily and sufficiently eliminate the causes of noise.

E1 Structure of the Invention That is, the present invention involves scraping off the processed surface of a bulk magnetic material (e.g., ferrite core material) processed into a predetermined shape in a vacuum (e.g., by sputter etching), and then separating the processed surface into a separate material. The present invention relates to a method for manufacturing a recording and/or reproducing electromagnetic transducer, in particular a magnetic head, in which a magnetic material is deposited (for example, sendust is grown by sputtering).

To, Example The present invention will be explained in detail below.

1 to 3 show a method of manufacturing a one-channel bulk type magnetic head according to a first embodiment of the present invention.

First, as shown in Figure 1A, ferrite single crystal (for example, Mn
- A bulk 21 made of (Zn ferrite single crystal) is cut out, and a groove 30 for winding is formed in it. This can be formed using a guissing tool or the like using a known method.

Next, this bulk 21 is placed in a sputtering apparatus 31 as shown in FIG. 2A, and with a predetermined area including the groove 30 covered with a mask material (not shown), the inside of the apparatus is evacuated (for example, 1.OX 10' Torr), then Ar gas is introduced to bring the whole body to a predetermined pressure (e.g. 5 x 10"3Torr).
rr), and a voltage is applied between the counter electrode 32 and a discharge. At this time, the counter electrode 32 is made of Fe-AJ in advance.
- A high magnetic permeability material 22 such as 3i-based sendust is arranged, and a shielding plate 33 is provided between the bulk 21 and the sputter-etched particles of the bulk 21 to prevent it from adhering to the high magnetic permeability material 22 such as sendust. That's what I do. That is, Ar ions generated within the apparatus sputter the bulk 21, particularly the surface 34 which becomes the magnetic gap surface, and sputter-etch that surface. As a result, the strain remaining on the surface 34, that is, the layer whose magnetic properties have been altered due to processing, is sufficiently etched away.

Next, as shown in FIG. 2B, the polarity of the electrodes is changed, the shielding plate 33 is removed, and the high magnetic permeability material 22 as a target is sputtered using Ar+.
A high magnetic permeability layer 32 is formed on the bulk surface 34 as shown in Figure B.
is grown to a predetermined thickness.

Next, as shown in FIG.
The iOz film 35 is grown thin. This 5i02 film determines the magnetic gap and can be formed, for example, by sputtering.

Next, as shown in FIG. 1D, a pair of bulks 2 of the same shape are
1 to face each other, and a fused glass rod 36 is placed between them, and both bulks 21 are brought together.

In this state, heat the glass rod 36 to a temperature that melts it, and
As shown in the figure, both bulks 21 are completely joined and integrated by fusion. The thus obtained head material is further processed into a curved surface as shown by the dashed line on the surface that contacts the magnetic recording medium, and then cut into a head as shown in FIG. 6. The side of the cut head facing the magnetic recording medium is shown in FIG.
Numerals a and 21b are core bodies cut out from 21, 23 is a magnetic gap, and 37 is a coil winding hole (see FIG. 1E).

As explained above, according to this embodiment, the magnetic gap surface 34 is first activated by sputter etching using the common sputtering device 31, and then the same surface is activated by the original sputtering. Since the high magnetic permeability layer 32 is grown on the surface, the surface 3 is grown by sputter etching.
This means that the layer with altered magnetic properties of No. 4 can be completely removed, and the adhesion of the high magnetic permeability layer 32 is improved. Therefore, noise considered to be caused by the altered layer on this surface 34 can be effectively removed.

Moreover, since sputter etching and sputtering can be performed using a common sputtering device, operability is good, continuous processing is possible, and process implementation is facilitated. Furthermore, if the present invention is combined after chemical etching with H3PO4 or the like, the etching step of the present invention can be shortened and the same effect can be obtained.

Further, as clearly shown in FIG. 3, in the head according to this embodiment, the boundary 20 between the high magnetic permeability layer 32 and the core bodies 21a, 21b is perpendicular to the medium running direction 38 or parallel to the magnetic gap 23 (i.e., the boundary 20 is parallel to the magnetic gap 23). Although the above-mentioned angle θ=0°), even with this structure, due to the above-mentioned reduction in noise, it is possible to obtain performance equivalent to or better than a head provided with an azimuth angle. In addition, since it is not necessary to provide the azimuth angle as described in FIGS. 6 and 7, the head shape is simplified, the degree of freedom in design increases, and there are fewer restrictions, making it easier to manufacture the head. becomes easier.

In the above, it is sufficient that the amount of core material removed by the sputter etching shown in Figure 2A is approximately 1 μm thick, and the degree of vacuum and other conditions at that time are those of ordinary high permeability materials (such as sendust). They may be substantially the same except for the sputtering (see FIG. 2B) and the polarity of the electrodes. In addition, in a method in which chemical etching is first performed and this is combined with the sputter etching described above, the core material may be scraped off to a thickness of 0.2 μm by sputter etching.

The core material 21 (furthermore, 21a, 21b) is made of a magnetic material with high electrical resistance, such as ferrite material, permalloy material, alperm material, etc.
n-Zn ferrite sintered material is best. Also,
The high magnetic permeability material 32 is Sendust (Fe-31-Al1 series =
5 to 11% by weight Si, 3 to 8% by weight Al, the remainder being substantially Fe), permalloy, etc. can be used, but sendust is preferred.

4 and 5 show other embodiments of the present invention.

In this example, the magnetic gap surfaces 34 of the core bodies 21a, 21b are shaped like grooves that are deep in the center and shallow on both sides, and are provided with the azimuth angle θ as described above. However, similarly to the above-described embodiment, after processing the groove 34, sputter etching with Ar+ is performed, the sendust layer 32 is grown by sputtering, and further steps are performed to finish the head.

Therefore, the layer with altered magnetic properties on the gap surface 34 can be sufficiently removed to reduce noise, and the head can also be manufactured easily.

Furthermore, by making the boundary surface 20 inclined with respect to the magnetic gap 23, it is possible to reduce the noise caused by the pseudo gap, so that in addition to the above-mentioned effect, it is possible to further reduce the noise.

Next, the present invention will be explained in more detail using specific examples.

After forming a winding groove in the L M n -Z n ferrite single crystal as shown in FIG. 1A, the member was placed in the sputtering apparatus shown in FIG. 2A, and 1. OX 10' Tor
Vacuum to r. After that, put Ar gas and
Set the temperature to 10-3 Torr, apply a power of 5w/c+a, generate a discharge, and sputter-etch the surface to a thickness of 1μm.
etching. After that, change the polarity of the electrode, sputter a Sendust target, and apply 20% of Sendust to the member.
Form cn. Thereafter, the surface is polished and a magnetic head is manufactured in a well-known manner.

After forming grooves for winding in a Mn-Zn ferrite single crystal as shown in FIG. 1A, the surface is polished to IS roughness.

Thereafter, the surface is etched with a 10% aqueous solution of H3PO4. After that, proceed as in Example 1.

A head with an azimuth angle θ is manufactured as shown in FIGS. 4 and 5. However, sputter etching of the magnetic gap surface,
Sputtering of sendust is performed in the same manner.

#-<Comparative Example) As shown in Figures 6 and 7, the winding window and 7-shaped groove of the head were made, the surface was roughened to IS, and the surface was etched with a 10% aqueous solution of H3PO4, and then Sendust was applied. and create a head.

Plate work (comparative example) As shown in Figure 1E, sendust is deposited parallel to the gap without sputter etching.

The recording/reproducing characteristics of the head for each of the above sides were measured under the following conditions, and the results are shown in the table below.

Magnetic recording medium: 0 to 10 MHz under conditions of 1250θe head and relative speed of 5.0 m/s between head and medium.
When a sweep waveform that gradually changes up to
It is expressed as g (Vg/V G).

Although the present invention has been illustrated above, the above-mentioned example can be further modified based on the technical idea of the present invention.

For example, as a method for removing the above-mentioned nonmagnetic altered layer, in addition to sputter etching, ion milling or the like which can be scraped off in a vacuum may be used. Further, the high magnetic permeability material layer may be formed by a vacuum evaporation method instead of sputtering. The shape, structure, size, and material of each of the constituent parts of the spatula described above may be modified in various ways. Although the above-mentioned head is for one channel, the present invention can also be applied to a known two-channel head. Further, the use of the head is not limited to video, but may also be used for audio.

Effects of the Invention As described above, in the present invention, the machined surface of the bulk magnetic material is scraped off in a vacuum, so the layer with altered magnetic properties on the machined surface can be completely removed. The adhesion of the magnetic material to be adhered is improved. Therefore, noise considered to be caused by the altered layer on this surface can be effectively removed. Moreover, as the adhesive strength is improved, polishing of high magnetic permeability materials such as sendust can be performed, and workability is improved. Also,
Since the process of scraping the machined surface and adhering the magnetic material can be performed using a common vacuum device, the process is easy to operate and can be performed continuously.

[Brief explanation of the drawing]

1 to 5 show embodiments of the present invention. 2A and 2B are schematic sectional views of a vacuum device used for sputter etching and sputtering, FIG. 3 is a plan view of the head, FIG. 4 is a perspective view of another example of the head, and FIG. 5 is a perspective view of the head. is a plan view of the same head. FIG. 6 is a perspective view of a conventional head, and FIG. 7 is a plan view of the same head. In addition, in the symbols shown in the drawings, 21.21a, 21b... Core material or core body 22...
...... High magnetic permeability material 23 ...... Magnetic gap 32 ...... High magnetic permeability layer 33 ...... Shielding plate 34 ... ...Magnetic gap surface (processed surface) 35
......5i02 film 36... Fused glass 37... Winding hole.

Claims (1)

[Claims] 1. A method for manufacturing an electromagnetic transducer for recording and/or reproduction, in which the processed surface of a bulk magnetic material processed into a predetermined shape is scraped off in a vacuum, and then another magnetic material is attached to the processed surface.