JPS5816531B2 - Manufacturing method of magnetic head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a high-density magnetic recording head with a narrow track width.

FIGS. 1a, b, and c are perspective views of the main parts of monolithic floating heads, embedded floating heads, and their magnetic cores that have been used up to now, and 1 is a slider for realizing a minute flying height; 2 is a track portion, and 3 is a gap portion.

In a monolithic head, the slider part and the head part are integrally processed from the same ferrite, whereas in an embedded head, a magnetic core part made of ferrite is glass-fused to a slider part made of a non-magnetic material such as barium titanate. Make it by wearing it.

Traditionally, this type of floating head has been made by machining methods.

However, the ferrite that is the material of the floating head has a thickness of several μm.
Since it is a brittle material made up of aggregation of crystal grains of ~ several hundred μm, it is easy for grain size units to be missing, and when machining is used to process track widths of around 20 μm, the manufacturing yield is extremely poor. .

Further, as the track width becomes narrower, its allowable dimensional tolerance becomes smaller.

Since an error of several micrometers cannot be avoided in the machining method, it is necessary to perform a small amount of machining and then check the track width. When the allowable value was about ±1 μm, the M manufacturing yield became extremely poor.

Therefore, in Japanese Patent Application No. 50-39355 (Japanese Unexamined Patent Publication No. 51-114111), the inventors of the present invention processed the air bearing surface and the track portion by ion etching processing targeting the head air bearing surface (slider surface). We proposed a method and clarified that narrow track machining can be performed with high precision. However, in this case, as shown in Fig. 2, due to the existence of leakage magnetic flux passing through the gap 4 of the etched part, It has the disadvantage that the inductance is larger than that of a machined head, and also has the disadvantage that unless the etching amount is increased, signals will be recorded on the medium due to leakage magnetic flux due to the gap portion 4 in the ion-etched portion.

FIG. 3 shows a method proposed by the present inventors in Japanese Patent Application No. 51-137079 (Japanese Unexamined Patent Publication No. 53-61319) in order to solve this drawback. The head expanded by laser processing is shown.

Although this method eliminates the drawbacks of the conventional method, it increases the number of processing steps and has the disadvantage that it is difficult to control the position of the laser spot when processing the gap portions on both sides of the track.

In order to solve these drawbacks, the present invention forms protrusions corresponding to the track width in a direction parallel to the medium on the gap abutting surfaces, and connects the protrusions to widen the gap width in the area other than the track part. At the same time, the influence of the magnetic flux leaking from there is reduced, and at the same time, the parts other than the track portion are processed to move away from the medium surface, so that the influence of the magnetic flux leaking from there is further reduced.The drawings will be described in detail below.

FIGS. 4-3 to 4-C are main body diagrams illustrating the manufacturing process of an embodiment of the present invention.

Note that this embodiment relates to a monolithic floating head.

4. FIGS. 3-C (1) A ferrite piece 5 on which a recess 5A has been formed, which is generally called window processing, and a ferrite piece 6 on which a protrusion 6A has been formed, for example, by ion etching, are prepared.

It should be noted that the ferrite piece 5 is finished with final processing and is wound with a wire to form one of the magnetic circuits.

Further, the ferrite piece 6 is ultimately processed into a slider and becomes the other magnetic circuit.

Refer to Figure 4 (2) When the ferrite piece 5 and the ferrite piece 6 are made to face each other, since the protrusion 6A of the ferrite piece 6 exists,
A gap E is formed between the ferrite piece 5 and the ferrite piece 6 by that amount.

In the present invention, J fills the glass 1 above and below the gap to bond them together.

Incidentally, on the surface where the protruding portion 6A and the ferrite piece 5 abut, for example, a certain metal is vapor-deposited to a thickness of about 1-1.3 C μm so that the ferrite pieces can abut against each other while maintaining a predetermined gap. do.

Further, it goes without saying that the width of the protrusion 6A when viewed in plan is approximately equal to the track width.

(3) Track processing and slider processing are performed by applying, for example, an ion etching method.

That is, the portion represented by the sandy pattern in FIG. 4b is removed.

(4) For example, by applying a machining method, cutting is performed along the -A chain line and the double-dash chain line l.

See Figure 4C. (5) The core obtained after processing is shown.

Note that parts designated by the same symbols as those previously used represent the same parts.

In the above steps, it is optional that at least a portion of the track machining and slider machining processes and the cutting process be performed one after the other.

For example, it is also possible to remove in advance an unnecessary portion of the ferrite piece 5, that is, a portion along the chain line before performing ion etching for track processing and slider processing.

Further, the protruding portion may be formed not only on the ferrite piece 6 but also on the ferrite piece 5 side E.

FIG. 5 shows a first view of the main parts near the track section in Example E manufactured as described above.

As is clear from the figure, in the present invention, due to the presence of the protrusion 6A, a wide gap 4 is inevitably formed in a portion other than the regular gap 3, so no laser processing or the like is required to enlarge the gap 4. Unnecessary 0 Figure 6 shows the difference in level between the parts other than the track part and between the track parts, and the magnetic field E ( It is normalized by the magnetic field generated from the gap in the track section.

) is shown using the gap width of the portion other than the track portion as a parameter.

This figure shows that in a magnetic head using the conventional ion etching method, the gap width of the ion-etched part is the same as the gap length of the track part, so the etching amount is about 4 μm (this is the maximum etching amount that can be etched by ion etching). ).

), it is clear that the magnetic field E is about O1■,
The magnetic field generated from the gap portion other than the track portion cannot be ignored.

In the present invention, since the gap width in the portion other than the track portion is made wider than the normal gap length, the influence of the magnetic field generated from this portion is further weakened.

Assuming an ion etching method as an example of a processing method, etching of 4 to 5 .mu.m on one side is possible, so the gap width can be reduced to about 10 .mu.m, and can be further widened by using a chemical etching method.

Therefore, when the step amount X is 4 μm, the strength of the magnetic field generated from the gap portion other than the track portion is reduced to 3/3 of that of the conventional one.
4 to 1/2, resulting in electromagnetic conversion characteristics almost equivalent to those of a magnetic head produced by conventional machining methods.

On the other hand, track width accuracy f To be more specific, according to photolithography technology, patterns with a width of several micrometers can be formed in large quantities at once with high precision, and if ion etching is used as the etching method, the pattern can be Etching of approximately 4 to 5 μm can be performed without loss of accuracy.

In the embodiments described above, the description has mainly been given to monolithic heads, but the present invention can also be applied to so-called embedded magnetic heads.

In the recessed type head, the gap width in the gap part 4 of the part other than the track part is made smaller than the gap length in the gap part 3 of the track part by the same process as explained in FIGS. 4a and 4b. Manufacture magnetic cores that are twice as large.

In this case, since the slider material is provided separately, the ferrite piece 6 may be smaller than in a monolithic head.

Next, this magnetic core part is glass-fused to the slider material,
Thereafter, the track portion may be processed in the steps shown in FIG. 4 and subsequent steps.

Further, in the above embodiment, a protrusion with a width corresponding to the track width is formed on the mating metal surface, but as long as the width of the protrusion on the surface facing the medium surface is greater than or equal to the track width, the protrusion shape can be any shape. Anything is fine.

In this case, the correct track width can be achieved by forming protrusions on both abutting surfaces and shifting them so that they abut.8 As explained above, in the present invention, the gap width in the area other than the track portion is widened. At the same time as reducing the magnetic flux leaking from there, the part facing the medium other than the track part is processed so as to move away from the medium, further reducing the influence of the magnetic flux leaking from this part.
Electromagnetic conversion characteristics almost equivalent to heads produced by conventional machining methods can be obtained.

Furthermore, since the above-mentioned processing can be performed using photolithography technology and etching technology, narrow track widths, which are difficult to process using conventional machining methods, can be achieved with a high yield.

Therefore, the magnetic head manufactured by the method of the present invention is useful as a magnetic head for high-density recording.

[Brief explanation of drawings]

Figures 1a, b, and c are side views of the main parts of a monolithic floating magnetic head, an embedded type floating head, and its magnetic core portion manufactured by machining, and Figures 2a and b are views of the head manufactured by ion etching. A side view of the main part and an enlarged trunk view of the gap part, and Fig. 3 shows the enlargement N? of the gap part when the gap part of the head other than the track part shown in Fig. 2 is widened by laser processing. JF diagram, FIGS. 4a-c are explanatory diagrams of the manufacturing process of an embodiment of the present invention, and FIG. 5 is an enlarged Nfff diagram of the gap portion of a magnetic head obtained according to an embodiment of the present invention.
FIG. 6 is a diagram showing the relationship between the level difference in the track portion and the magnetic field generated from the gap portion other than the track portion, using the gap width of the portion other than the track portion as a parameter. In the figure, 1 indicates a slider portion, 2 a track portion, 3 a gap portion of the track portion, and 4 a gap portion other than the track portion.

Claims (1)

[Claims] 1 Form a protrusion having at least a track width on at least one surface of the gap abutting surfaces of the two parts constituting the magnetic core, then bond the two parts together, and then form a protrusion with at least a track width. 1. A method of manufacturing a magnetic head, comprising the step of digging down a medium facing surface in a portion other than the vicinity of a gap abutting surface having a width.