JPH0636220A - Manufacture of magnetic head core - Google Patents

Abstract

(57) [Abstract] [Purpose] When the two core materials are integrated with the bonding glass, the deteriorated portion of the core material due to the chemical reaction between the core material and the glass should not adversely affect the gap characteristics. [Configuration] The core materials 10 and 20 are integrally formed by pouring the bonding glass 30 melted in the direction from the outer surface of the gap toward the back of the gap into the gap between the joint between the ridge 16 for forming the gap and the flat core material 20. Glue to. With respect to the bonded core materials 10 and 20, the part on the inlet side into which the bonding glass 30 has been poured is cut off to the middle of the gap forming ridge 16 (position Y).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a core of a magnetic head used in a floppy disk device or the like, and more particularly to a technique for precisely processing the depth and length of a magnetic gap.

[0002]

2. Description of the Related Art A typical conventional manufacturing process of a magnetic head core for a floppy disk device is shown in FIGS. First, as shown in FIG. 1, a convex core material 10 in which two convex streak portions 12 and 13 are integrally formed along the long side thereof is provided on both sides of one side of a rectangular flat plate portion. One of the ridges 12 is a gap forming ridge with the gap inner slope 12a, and the other ridge 13 is a supporting ridge that functions as described below.

Next, as shown in FIG. 2, a convex core material 1
A thin film layer 14 whose thickness is precisely controlled is formed on the top surface of each of the two ridges 12 and 13 of No. 0. The thin film layer 14 is formed of, for example, SiO ₂ into a film having a constant thickness by sputtering.

Next, as shown in FIG. 3, a convex core material 1
0 is combined with another flat plate core material 20 to bring the flat plate core material 20 into close contact with the surfaces of the thin film layers 14 of the two ridges 12 and 13. In the combined state, the bonding glass 30 melted in the gap between the gap forming ridge 12 and the joint between the flat plate core material 20 and the gap between the supporting ridge 13 and the joint between the flat core material 20. And the two core materials 10 and 20 are bonded to each other with this bonding glass 30.

With respect to the core materials 10 and 20 integrated by the bonding glass 30 as shown in FIG. 3, the supporting ridges 13 are cut off by a grinder and the two-dot chain line X in FIG.
The portion below the position is cut off with a grinder. The processed product that has undergone this cutting process is shown in FIG. Here, the magnetic gap G is the joint surface between the plate-shaped core material 20 and the portion of the gap-forming ridge 12 that remains uncut. The length of the gap G (a minute distance between the ridge 12 and the core material 20 across the bonding glass 30) is defined by the thickness of the thin film layer 14 described above.

The processed part shown in FIG. 4 is thinly sliced as shown in FIG. 5, and the read / write coil 50 is mounted on the core material 10 of the sliced product.
A back bar 40, which is a yoke, is joined between the rear ends of the separated core materials 10 and 20. This is the bare magnetic head configuration for a floppy disk drive.

[0007]

FIG. 6 shows an enlargement of the portion of the gap G of the magnetic head core shown in FIG. 5 manufactured by the above-mentioned conventional method. In FIG. 6, L is the gap length and D is the gap depth. The gap length L and the gap depth D are extremely important parameters that determine the characteristics of the head, and it is important to finish them exactly as designed.

As shown in FIG. 6, according to the conventional method, when bonding the core materials 10 and 20 with the bonding glass 30,
Molten bonding glass 30 is poured into the gap G from the inner slope 16a of the ridge 12. In this bonding step, the gap inside corner 12b (corner between the gap inside slope 12a and the cap forming surface) of the core material 10 is altered or scraped off by a chemical reaction with the bonding glass 30. Such a chemical reaction is particularly remarkable between the ferrite and the bonding glass. Before the bonding step, both the gap forming surface of the protrusion 12 and the gap inner slope 12a are smoothly ground, and the gap inner corner 12b forms a clear ridge as shown by the dotted line in FIG. . This corner 12
In the bonding process, b is infinitely rounded off as shown by the solid line, and is deteriorated. Therefore, the effective gap depth D becomes smaller than the specified value, and the effective gap length L becomes larger than the specified value. Moreover, there are large variations in these errors.

The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to obtain a final gap even if a part of the core is scraped off or altered due to a chemical reaction between the bonding glass and the core material. It is an object of the present invention to provide a method of manufacturing a magnetic head core capable of finishing the length and the gap depth with high accuracy.

[0010]

Therefore, according to the present invention, the magnetic head core is manufactured by the following process steps.

A convex core material is integrally provided on one side of a rectangular flat plate portion with three convex strips along its long sides, and the central convex strip of the three convex strips is provided. The gap forming ridges are used, and the other two are used as supporting ridges.

Thin film layers each having a predetermined thickness are formed on the top surfaces of the two supporting ridges of the convex core material.

Another flat plate core material is combined with the convex core material, and the flat plate core material is brought into close contact with the surfaces of the thin film layers of the two supporting convex strips.

In the combined state of the two core parts, the bonding glass melted in the direction from the outer surface of the gap to the back of the gap is poured into the gap between the joint between the ridge for forming the gap and the flat core material. Then, the two core materials are integrally bonded.

Regarding the two bonded core materials,
The part on the inlet side into which the bonding glass is poured is cut off to the middle of the ridge portion for forming the gap.

[0016]

According to the above method, when the convex core material and the flat core material are bonded with the bonding glass, the molten bonding glass is poured from the outer surface side of the gap toward the back of the gap. Therefore, the corner portion of the core on the inlet side of the bonding glass in the pouring direction is altered or scraped off by a chemical reaction with the glass. However, when finishing the gap depth, the outer surfaces of the gaps of both core materials are ground, so parts that have been scraped off or deteriorated by the chemical reaction with the bonding glass are cut off,
It does not remain in the final magnetic head core.

[0017]

EXAMPLE A manufacturing process of a magnetic head core according to an example of the present invention is shown in FIGS. First, as shown in FIG. 7, one side of the rectangular flat plate is provided with 3
The convex core material 10 in which the convex strips 15, 16 and 17 of the book are integrally formed is provided. The central ridge portion 16 of the three ridge portions is a gap forming ridge portion, and in the illustrated state, a gap inner slope 16a is formed below and a glass pouring slope 16b is formed above. ing. The remaining two ridges 15 and 17 are supporting ridges that function as follows.

Next, as shown in FIG. 8, the supporting projections 15
A thin film layer 14 having a predetermined thickness is formed on the respective top surfaces of and by sputtering of SiO ₂ .

Next, as shown in FIG. 9, the convex core material 1
0 is combined with another flat core material 20, and the flat core material 20 is brought into close contact with the surface of the thin film layer 14 of the two supporting ridges 15 and 17. Then, the ridge portion 1 for forming a gap
At the same time as pouring the bonding glass 30 from above into the joint between the core material 20 and the core material 20, the bonding glass 30 from above into the joint between the supporting ridge 17 and the core material 20.
Pour. The core materials 10 and 20 are integrally bonded by glass bonding at these two locations. With respect to the integrated component obtained by this adhesion, the supporting ridges 17 are cut off by a grinding machine, and the upper part is cut off by a grinding machine from a position indicated by a chain double-dashed line Y at a substantially intermediate position of the gap forming ridges 16. . Figure 1 shows the machined parts that have undergone this grinding process.
It is shown in 0. Although the processed product of FIG. 10 is shown upside down, it corresponds to the state of FIG. 4 showing the conventional method. This processed product is thinly sliced and read / write coil 50
11 shows a state in which the back bar 40 is attached. This corresponds to FIG. 5 in the conventional method.

FIG. 12 shows details of a state in which the bonding glass 30 is poured into the joint portion (gap portion) between the ridge portion 16 for forming the gap and the flat plate type core material 20 in the manufacturing process described above. As described above, molten bonding glass is poured from the glass pouring slope 16b of the gap forming projection 16 into the gap portion as indicated by the arrow in FIG. Therefore, the corners between the glass pouring slope 16b and the gap forming surface are altered or scraped off by a chemical reaction with the glass. The dotted line in FIG. 12 shows the shape of the upper corner of the convex streak 16 before the bonding step, but it may be scraped off or deteriorated as shown by the solid line through the bonding step.

In the method of the present invention, in the core part in the state shown in FIG. 12, the part on the inlet side (upper part) into which the bonding glass 30 is poured up to the position indicated by the chain double-dashed line Y in the middle of the gap forming ridge 16. ) Is cut by a grinder.

Therefore, as shown in FIG. 13, the deteriorated portion scraped or altered by the chemical reaction with the bonding glass 30 is completely eliminated, and the gap depth D and the gap length L are precisely finished as designed. .

[0023]

As described in detail above, according to the manufacturing method of the present invention, although local deformation and abrasion such as deformation of the core due to a chemical reaction between the core material and the bonding glass are unavoidable, Since the deteriorated portion is completely cut off by finishing the gap depth, the deteriorated portion of the core does not adversely affect the gap depth and the gap length as in the past, and a high-quality magnetic head core with precise gap characteristics. Can be manufactured.

[Brief description of drawings]

FIG. 1 is a first manufacturing process diagram of a conventional magnetic head core.

FIG. 2 is a second manufacturing process diagram of a conventional magnetic head core.

FIG. 3 is a third manufacturing process diagram of the conventional magnetic head core.

FIG. 4 is a fourth manufacturing process diagram of the conventional magnetic head core.

FIG. 5 is a fifth manufacturing process diagram of the conventional magnetic head core.

FIG. 6 is an enlarged view of a gap portion showing a conventional problem.

FIG. 7 is a first manufacturing process diagram of the magnetic head core according to the embodiment of the present invention.

FIG. 8 is a second manufacturing process diagram of the magnetic head core according to the embodiment of the present invention.

FIG. 9 is a third manufacturing process diagram of the magnetic head core according to the embodiment of the present invention.

FIG. 10 is a fourth manufacturing process diagram of the magnetic head core according to the embodiment of the present invention.

FIG. 11 is a fifth manufacturing process diagram of the magnetic head core according to the embodiment of the present invention.

FIG. 12 is an enlarged view of an essential part 1 in the manufacturing process of the embodiment.

FIG. 13 is an enlarged view of the essential part 2 in the manufacturing process of the embodiment.

[Explanation of symbols]

 10 Convex Core Material 14 Thin Film Layer 15 Supporting Convex Strips 16 Gap Forming Convex Section 16a Gap Inside Slope 16b Glass Pour Slope 16c Gap Inside Corner 17 Supporting Convex Section 20 Flat Core Material 30 Bonding Glass G Gap D Gap depth L Gap length

Claims (1)

[Claims] 1. A method of manufacturing a magnetic head core, comprising the following steps. Providing a convex core material on one side of a rectangular flat plate with three ridges along its long side integrally formed, for forming a gap in the center ridge of the three ridges The ridges and the other two are the ridges for supporting. A thin film layer having a predetermined thickness is formed on each of the top surfaces of the two supporting ridges of the convex core material. Another convex core material is combined with the convex core material, and the flat core material is brought into close contact with the surfaces of the thin film layers of the two supporting ridges. In the combined state of the two core parts, the bonding glass melted in the direction from the outer surface of the gap toward the back of the gap is poured into the gap between the joint between the ridge portion for forming the gap and the flat core material. The two core materials are bonded together. With respect to the two bonded core materials, the part on the inlet side into which the bonding glass is poured is cut out up to the middle of the gap forming ridge.