JPS61162813A - Manufacture of compound magnetic head - Google Patents

Abstract

PURPOSE:To perform high-density recording reproduction with small-sized constitution by providing a compound head, formed by cutting surfaces of base bodies molded out of a nonmagnetic material and joined them together, to base bodies of one core half body of a recording/reproducing head block and an erasing head block. CONSTITUTION:A block which is sectioned pentagonally is used as a base body 5a and a coil groove 4 is formed in one flank; and vertex parts of the pentagon are ground and a metallic magnetic thin film 5b is laminated on one flank to a specific thickness to form the 1st core half body 5. Similarly, the 2nd core half body 6 is prepared and a gap spacer 7 is formed on a metallic magnetic thin film 6b to a specific thickness to complete the 2nd core half body 6. The 1st core half body 5 and the 2nd core half body 6 are joined together, a reinforcing material 8 such as glass is charged between the magnetic thin films 5b and 6b, and one surface of the base body 6a is ground away to form the base body 6a having a desired thickness. Similarly, the erasing head 2 is formed and the block of the recording/reproducing head 1 and the block of the erasing head 2 are connected by joining surfaces of the base bodies 6a and 12a of the 2nd core half bodies to obtain the compound head. Consequently, the small-sized head very suitable to high-density recording and reproduction is obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a composite magnetic head in which a recording/reproducing head and an erasing head are integrally connected, and in particular to a method for manufacturing a composite magnetic head suitable for recording/reproducing magnetic disks. It is related to.

[Conventional technology]

4 and 5 are diagrams showing a conventional bulk type composite magnetic head. FIG. 4 is a plan view of the magnetic head, and FIG. 5 is a sectional view taken along the line E in FIG. 4.

The recording/reproducing head 1 and the erasing head 2 are integrally connected via a non-magnetic plate 3 to avoid mutual magnetic influence. The recording/reproducing head l includes a first core half 5 made of, for example, ferrite, in which a coil groove 4 is formed by machining such as cutting, and a first core half made of, for example, ferrite, which is disposed to face the first core half 5. Two core halves 6, a gap spacer 7 made of silicon dioxide, for example, interposed between the two core halves 5.6, and a reinforcement made of glass, etc., provided near the joint between the two core halves 5.6. 8 and an exciting coil 9 wound on the coil groove 4 of the first core half 5. On the other hand, the erasing head 2 has a coil groove 1o formed by machining such as cutting. A first core half 11 made of ferrite, a second core half 12 made of ferrite, for example, arranged to face the first core half 11, and both core halves 11 and 12 are interposed. For example, a gap spacer 13 made of silicon dioxide, a reinforcing part 14 made of glass or the like provided near the joint between the core halves 11 and 12, and a coil groove l of the first core half 11.

The excitation coil 15 is wound on top of the excitation coil 15.

In FIG. 4, arrow X indicates the running direction of a magnetic recording medium (not shown) such as a magnetic disk, and the recording/reproducing head 1 is arranged on the upstream side of the running direction X, and the erasing head 2 is arranged on the downstream side. The magnetic gap of the recording/reproducing head l formed by the gap spacer 7 and the magnetic gap of the erasing head 2 formed by the gap spacer 13 are arranged in a relationship as shown in FIG.

Therefore, the recording/reproducing head 1 partially erases the edge of the magnetic disk to obtain an off-track margin for the head.

FIGS. 6 and 7 are explanatory diagrams showing how recording tracks are formed by this type of composite magnetic head. FIG. 6 shows how tracks are formed on the outer circumferential side of the magnetic disk, and FIG. Each figure shows the state of track formation on the inner circumferential side.

In the figure, 16 is the magnetic gap of the recording/reproducing head, 17 is the magnetic gap of the erasing head, 18 is the recording track, 19 is the rotation center of the magnetic disk, 20 is the erase width on the inner circumference side erased by the erasing head, and 21 is the magnetic gap of the erasing head. Each shows the track pitch with respect to its neighbor.

A magnetic disk is provided with an annular recording band having a predetermined width, and its outer and inner circumferential sides have different curvatures.6 Comparing the outer circumferential side with a small curvature and the inner circumferential side with a large curvature. The erasing width 20 by the erasing head is larger on the inner circumferential side than on the outer circumferential side, and as a result, the track pitch 21 changes slightly between the outer circumferential side and the inner circumferential side. This is especially noticeable when there is a large change in curvature between the outer and inner circumferential sides of a small magnetic disk, and moreover, the recording/reproducing head l
the magnetic gap 16 of the erase head 2 and the magnetic gap 17 of the erase head 2
This is noticeable when the distance between the

As mentioned above, if the track pitch (track spacing) differs depending on the radial position, this will cause problems, especially in the case of high-density recording.

To address this problem, attempts have also been made to make the second core half 6.degree. 12 thinner by polishing to reduce the spacing of the magnetic gaps 16.degree. 17. However, in the case of mechanical processing as described above, considering manufacturing yield, the limit is to keep the gap distance L t-0.8 m around, and a sufficient effect cannot be obtained.

[Problem that the invention seeks to solve]

The purpose of the present invention is to eliminate such drawbacks of the prior art,
In a composite head that integrates a recording/reproducing head and an erasing head, the distance between both magnetic gaps is made sufficiently small, and the off-track margin is made sufficiently large by 1.+1%.
An object of the present invention is to provide a method for producing a fR lie ÷ wear order A-1 degree.

[Means for solving problems]

In order to achieve the above-mentioned objects, the present invention involves molding the base of the core half of each of the recording/reproducing head block and the erasing head block using a non-magnetic material, and cutting the surface of each of the bases. It is characterized by being joined to each other to obtain an integrated composite head.

(Example) FIGS. 1 and 2 are diagrams showing a composite magnetic head manufactured by the manufacturing method of the present invention. FIG. 1 is a plan view of the magnetic head, and FIG. 2 is a sectional view taken along the Rollo line of FIG. 1. It is.

The recording/reproducing head 1 includes a first core half 5 having a metal magnetic thin film 5b adhered to the surface of a base 5a made of, for example, ceramics or non-magnetic ferrite, in which a coil groove 4 is formed, and a first core half 5 facing the first core half 5. A second core half 6 is disposed in such a manner that a second core half 6 has a gold 1ift thin film 6b deposited on the surface of a base 6a made of ceramics, non-magnetic ferrite, etc., and a second core half 6 is interposed between both core halves 5.6. A gap spacer 7 made of silicon dioxide, for example, a reinforcing part 8 made of glass, etc., provided near the joint between the two core halves 5.6, and a coil groove 4 wound on the first core half 5. It does not have a non-magnetic plate 3 like the conventional example shown in FIGS. 4 and 5.

On the other hand, the erasing head 2 is completely similar to the recording/reproducing head 1, and includes a first core half 11 consisting of a coil groove 10, a base body 11a, and a magnetic thin film flb, a base body 12a, and a magnetic thin film 12b.
The second core half 12 includes a gap spacer 13, a reinforcing portion 14, and an excitation coil 15.

The materials of the metal magnetic thin films 5b, 6b, llb, and 12b provided on the core halves 5.6 and 11.12 are as follows:
Crystalline alloys and amorphous alloys having high saturation magnetic flux density and high magnetic permeability are used.

Examples of such crystalline alloys include iron-aluminum-silicon alloys, iron-silicon alloys, and iron-nickel alloys. On the other hand, the amorphous alloy includes one or more elements selected from the group of iron, nickel, and cobalt, and one or more elements selected from the group of phosphorus, carbon, boron, and silicon.
Aluminum, germanium, beryllium, tin,
There are alloys to which elements such as indium, molybdenum, tungsten, titanium, manganese, chromium, zirconium, hafnium, and niobium are added, and alloys containing cobalt and zirconium as main components and the above-mentioned additive elements.

Further, the base body 5a of the first core half body 5, 11.

11a may be made of a magnetic material, and examples of the magnetic material used include ferrite having high magnetic permeability such as manganese-zinc ferrite.

Next, the manufacturing process of the composite magnetic head will be explained based on FIG. 3.

As shown in Figure 3+8), first, the first
A base body 5a for configuring the core half body 5 is prepared as a block with a pentagonal cross section.A coil groove 4 is formed on the side surface by cutting (as shown in BL), and the apex portion of the pentagon is polished to form a flat portion 5C. Then, a flat part 5C is formed.
A metal magnetic thin film 5b having a predetermined thickness is laminated on one side of the base body 5a including the core body 5a by thin deposition, sputtering, etc., to form the first core half 5.

Similarly, as shown in FIG. 3+dl, a second core half 6 is prepared, the apex part of the pentagon is polished to form a flat part 6C (II), and then vapor deposition is performed on one side surface including the flat part 6C. Then, a metal magnetic thin film 6b of a predetermined thickness is laminated by sputtering or the like, and a gap spacer 7 of a predetermined thickness is further formed on the metal magnetic thin film 6b on the flat part 6C. do.

The first core half 5 and the second core half 6 are connected to their flat portions 5.
c and 6c are joined as shown in FIG.

The side surface of the base body 6a on the second core half 6 side of the block of the recording/reproducing head l thus obtained is removed by cutting to obtain a base body 6a having a desired thickness as shown in +1).

Erasing head 2 is created in exactly the same manner. That is, the third
As shown in FIG.
The surface of the base body 12a on the core half body 12 side is formed by cutting to a desired thickness.

Then, the block of the recording/reproducing head 1 and the block of the erasing head 2 are connected to the bases 6a, 12 of the second core half.
If it is integrated by joining the a surface, it will be shown in Figure 3)
A composite head as shown in FIG. 1 is obtained, which does not have a non-magnetic plate between the two second core halves 6°12.

Therefore, the distance l between the magnetic gap of the recording/reproducing head 1 and the magnetic gap of the erasing head 2 can be made smaller than before, and in the embodiment, the distance l is 0.5 va, and the crosstalk characteristics are also better than before. I was able to make it happen.

〔Effect of the invention〕

The present invention is as described above, and the composite magnetic head molded by the manufacturing method of the present invention can reduce the magnetic gap distance between the recording/reproducing head and the erasing head, and when recording on a magnetic disk using this head. In this case, the off-track margin can be made sufficiently large, making it extremely suitable for compact, high-density recording and reproduction. Furthermore, the manufacturing process is simple and the number of man-hours can be reduced.

[Brief explanation of drawings]

FIG. 1 is a plan view of a composite magnetic head manufactured according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the E-I line in FIG. 1, and FIG. 4 is a plan view of a conventional composite magnetic head, FIG. 5 is a sectional view taken along the Rolo line of FIG. 4, and FIGS. 6 and 7 are outer and inner peripheral sides of a conventional composite magnetic head. FIG. 3 is an explanatory diagram showing the formation state of recording tracks in FIG. 1...recording/reproducing head, 2...erasing head, 5
...First core half, 5a...Base, 5b...
-Magnetic thin film, 6...second core half, 6a...substrate, 6b...magnetic thin film, 7...gap spacer, 9...excitation coil, 11...・First core half, lla...substrate, llb...magnetic thin film, 12
...Second half body, 12a...Base body, 12b.
...Magnetic thin film, 13...Gap spacer, 15
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Claims (1)

[Claims] A composite magnetic head in which a recording/reproducing head and an erasing head are sequentially arranged along the running direction of a magnetic recording medium includes a second core half in which a magnetic thin film is deposited on the surface of a base made of a non-magnetic material, and an excitation coil. A first core half having a magnetic thin film coated on the surface of the base body to which the magnetic thin film is attached is prepared, and the first and second core halves are attached via a gap spacer made of a non-magnetic material so that the respective magnetic thin films face each other. The core halves were joined to form head blocks of a recording/reproducing head and an erasing head, and in each head block, the surface of the base opposite to the magnetic thin film in the second core half was cut to form the desired thickness. After that, the surfaces of both bases are joined together to integrate a recording/reproducing head and an erasing head, thereby producing a composite magnetic head.