JPH04109406A - Magnetic head - Google Patents

Abstract

PURPOSE:To ensure magnetic coupling between a metallic magnetic thin film and a back part, and in addition, to simplify a manufacturing process by making the metallic magnetic thin film come into a back part side deeper than the junction interface of a front part and the back part jointed at the back side deeper than the depth zero position of a magnetic gap. CONSTITUTION:The front parts 1, 2 are made into what is called laminate structure in which the metallic magnetic film films 5, 6 are sandwiched because the metallic magnetic thin films 5, 6 are held between non-magnetic members 7, 8 consisting of ceramic, etc., from their thickness direction. Here, the metallic magnetic thin films 5, 6 are made to come into the back parts 3, 4 side deeper than the junction interfaces 13, 14. Namely, the metallic magnetic thin films 5, 6 are put as being extended to the back side wider than the junction interfaces 13, 14, and are formed so as to come into a part of base boards 9, 10. Thus, the magnetic coupling between the metallic magnetic thin films 5, 6 and the back parts 3, 4 is ensured, and simultaneously, the manufacturing process is simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic head mounted on a magnetic recording/reproducing device such as a video tape recorder.

[Summary of the invention]

The present invention comprises a front part sandwiched between a metal magnetic thin film or a non-magnetic material and a magnetic gap formed between the abutting surfaces of the metal magnetic thin film, and a back made of ferrite that forms a closed magnetic path together with the front part. In a composite magnetic head consisting of a front part and a back part, the magnetic coupling between the metal magnetic thin film and the back part is ensured by making the metal magnetic thin film penetrate closer to the back part than the bonding interface between the front part and the back part. The aim is to simplify the process and create a structure that is suitable for mass production.

[Conventional technology]

For example, in magnetic recording and reproducing devices such as video tape recorders, information signals are being recorded at shorter wavelengths for the purpose of improving image quality. High coercive force magnetic recording media such as metal tapes and vapor-deposited tapes in which a ferromagnetic metal material is directly deposited on a base film have come into use.

On the other hand, research is also progressing in the field of magnetic heads to deal with this problem, and in order to enable high-density recording on high-coercivity magnetic recording media, the core material is a metal magnetic head with a high saturation magnetic flux density. A variety of magnetic heads have been developed that use the same method to narrow the track.

As such a magnetic head, for example, JP-A-59-72
As shown in the No. 638 revolution, the magnetic gear knob part is made of a metal magnetic thin film with high saturation magnetic flux density such as sendust, and the front part and the rear part are made of a so-called laminate by bonding non-magnetic films to both sides of this metal magnetic thin film. It has been proposed that a bank portion made of ferrite or the like constituting a magnetic circuit is integrally bonded.

In this head, since the thickness of the metal magnetic thin film is the track width of the magnetic gap, the track width can be easily narrowed by controlling the thickness of the metal magnetic thin film, and the track width can be easily achieved by controlling the thickness of the metal magnetic thin film. It has advantages such as excellent wear resistance since it is made of non-magnetic material except for the sliding part or the magnetic gap part, and excellent regeneration efficiency because the magnetic path cross-sectional area of the hack part is large.

[Invention or problem to be solved]

By the way, in the above-mentioned magnetic head, a block made of a non-magnetic material having comb-like protrusions corresponding to the groove shape is fitted into a block made of a metal magnetic material having a groove having a rectangular cross section. Then, this block made of non-magnetic material was flat-polished to form a so-called laminate-like front part with non-magnetic material fitted into the groove, and a back part made of ferrite that made up the rear magnetic circuit was bonded to this. be done.

In this way, in the manufactured magnetic head, it is necessary to fit a non-magnetic material into a grooved block made of a metal magnetic material, so it is necessary to machine the grooves and ridges formed in these blocks with high precision. . Therefore, with this head, not only is it not easy to process these grooves and protrusions, but also a process of fitting these blocks into each other is required, which is disadvantageous in terms of mass production due to the increased number of man-hours. Also,
In the above-mentioned magnetic head, since the metal magnetic thin film is bonded to the ferrite or glass fusion bond, the magnetic coupling is not reliable and the output is unsatisfactory.

The present invention has been proposed in view of the above-mentioned conventional circumstances, and it not only ensures the magnetic coupling between the metal magnetic thin film and the back part, but also simplifies the process and greatly improves mass productivity. The object of the present invention is to provide a magnetic head having a structure that allows for significant improvements.

[Means to solve the problem]

In order to achieve the above object, the present invention comprises a front part which is sandwiched between a metal magnetic thin film or a non-magnetic material and a magnetic gap is formed between the abutting surfaces of the metal magnetic thin film, and a front part made of ferrite. The front part and the back part have a bonding interface on the back side of the zero depth position of the magnetic gap, and the front part has a metal magnetic thin film. It is characterized in that it penetrates closer to the back portion than the bonding interface.

[Effect]

In the present invention, since the metal magnetic thin film constituting the magnetic gap part penetrates into the back part side beyond the bonding interface between the front part and the back part, which are joined on the back side of the zero depth position of the magnetic gap, these metal The magnetic coupling between the magnetic thin film and the back portion is ensured, and the manufacturing process can be simplified.

C Embodiment] Hereinafter, specific embodiments to which the present invention is applied will be described with reference to the drawings.

As shown in FIG. 1, the magnetic head of this embodiment has front parts (1) and (2) that form a magnetic gap part, and a back part that forms a closed magnetic path together with the front parts (1) and (2). It consists of parts (3) and (4).

The front part (+), (2) is a metal magnetic thin film (5
).

(6) is a non-magnetic material (7) made of ceramics etc., (
By sandwiching the metal magnetic thin films (5) and (6) in the film thickness direction, a so-called laminate structure is formed in which the metal magnetic thin films (5) and (6) are sandwiched. In the laminate structure, the thickness of the metal magnetic thin films (5), (6) or the track width Tw of the magnetic gap g is determined by controlling the thickness of the metal magnetic thin films (5), (6). It can be easily made into a narrower rack.

In addition, a magnetic gap g is formed between the abutting surfaces of these metal magnetic thin films (5), (6), or the metal magnetic thin films (5), (6) and the non-magnetic material (7), ( 8) is non-parallel to the magnetic gap g, so there is no risk that the bonding surface will operate as a pseudo gap.

A ferromagnetic alloy material having a high saturation magnetic flux density and excellent soft magnetic properties is used for the metal magnetic thin films (5) and (6), and it does not matter whether it is crystalline or amorphous. To give an example, Fe-Al! -3i alloy, Fe-Af alloy, Fe-3i-Co alloy, Fe-Ni alloy, F
e-Aj? -Ge alloy, Fe-Ga-Ge alloy, F
Examples include e-5i-Ge alloy, Fe-Co-8i-AI alloy, etc.Furthermore, in order to further improve corrosion resistance and wear resistance, Ti, Cr, Mn, Zr, Nb
Mo, Ta, W, Ru, Os, Rh,
(Ir, ReNi, Pb, Pt, Hf, V, etc.) may be added.

In addition, ferromagnetic amorphous metal alloys, so-called amorphous alloys (for example, one or more elements of Fe, Ni, Co and P
, C, B, and Si, or an AI containing these as main components.

Ge, Be, Sn, In, Mo, W, Ti, MnCr,
Examples include metal-metalloid amorphous alloys such as alloys containing Zr, Hf, Nb, etc., and metal-metal amorphous alloys containing transition elements such as Co, Hf, Zr, rare earth elements, etc. as main components.

In particular, when an amorphous alloy is used as the metal magnetic thin films (5) and (6), it is preferable to use Au bonding for the bonding of the magnetic core halves, which will be described later.

In other words, if the bond between the magnetic core halves is an Au bond,
Since the temperature never exceeds the thermal diffusion temperature or crystallization temperature, the amorphous alloy can be bonded while maintaining its excellent magnetic properties.

The metal magnetic thin films (5) and (6) can be formed using vacuum thin film forming techniques such as sputtering, vacuum evaporation, ion blating, cluster ion beam, etc., which have excellent film thickness control. will be adopted.

On the other hand, the back parts (3), (4) are connected to the substrate (9), (
10) The entire device is made of ferrite, and the cross-sectional area of the magnetic path on the back side is ensured, so that magnetic resistance can be reduced.

The front parts (1), (2) and the back parts (3), (4) configured as described above are joined on the back side of the zero depth position of the magnetic gap g, and as a result, It constitutes the magnetic core half-off (1), (If). That is, these front parts (1), (2) and back parts (3), (4) have a winding groove (H) regulating the depth of the magnetic gap g, an inclined surface (lla) of (12),
The bonding interface (+3) located in the middle of (12a),
(14) are joined together by glass fusion or Au bonding, and the front part (1) and the hack part (3) or the magnetic core half-closed (I) are connected to the front part (2) and the 7179 part (4). and magnetic core half-break (n), respectively.

Here, in the head of this example, the metal magnetic thin film (5),
(6) is arranged to enter the 7177th part (3), (4) side of the bonding interface (+3), (14).

That is, the metal magnetic thin films (5), (6) are provided to extend further to the back side than the bonding interfaces (13), (14), and are provided on the substrates (9), (10). It is shaped like a part of it. Therefore, the metal magnetic thin films (5), (6) and the substrate (
9), the magnetic coupling with (+O) becomes more reliable. In this way, simply the bonding interface (13), (1
4) with metal magnetic thin films (5), (6) and substrate (9),
Compared to the case where magnetic coupling with (10) is attempted, the magnetic resistance at the bonding interfaces (+3) and (+4) is suppressed, which is advantageous in terms of electromagnetic conversion characteristics. Also, in terms of the bonding strength between the front parts (1), (2) and the back parts (3), (4), the metal magnetic thin films (5), (6) are better than the back parts (3), (4). Since it is inserted into the inner wall, strong joint strength is ensured.

On the abutting surfaces of the magnetic core halves (I) (I[) configured as described above, the metal magnetic thin film (5), (
A magnetic gap g is formed by abutting the end faces of 6). In this example, the magnetic gap g is formed by providing a metal film made of Au (not shown) or a gap material. That is, the magnetic gap g is defined by the opposing metal magnetic thin films (5),
Metal films made of Au are sputtered on the gap forming surfaces of (6), respectively, and are formed by thermal diffusion between these metal films at low temperatures. Therefore, in the head of this example, there is no deterioration in the magnetic properties of the metal magnetic thin films (5) and (6). In addition, Au bonding provides a bonding strength several times higher than bonding with fused glass, so even if it is reheated after thermal diffusion bonding, there is no gap opening, which eliminates the stress of bonding after processing the head chip. An annealing treatment can be performed.

In addition, the joining of the above magnetic core half-breaks (1) and (If) is as follows:
In addition to the above-mentioned Au bonding, a glass fusion bonding method that is used in a normal head may also be used. Particularly in this case, it is desirable to use glass with a very low melting point so as not to deteriorate the magnetic properties of the metal magnetic thin films (5) and (6).

Next, a method of manufacturing the above-mentioned magnetic head will be explained.

In order to manufacture the above-mentioned magnetic head, first, as shown in FIG. 2(A).
As shown in , the ferrite block (I
5) - A non-magnetic material (16
) to join.

The non-magnetic material (16) can be bonded to the ferrite block (15) by glass fusion bonding or Au bonding.

Next, these ferrite blocks (15) and the non-magnetic material (
As shown in FIG. 2(B), a filling groove (17) for filling the metal magnetic material constituting the magnetic circuit in the front part is formed in the composite block consisting of 16).

The filling groove (17) has the same width as the track width Tw of the magnetic gap g, and has the same width as the track width Tw of the magnetic gap g.
5) and the non-magnetic material (16) to a deeper position than the bonding interface (18).

Next, a metal magnetic material is sputtered onto the non-magnetic material (16), including inside the filling groove (17).

As the metal magnetic material to be sputtered at this time, the above-mentioned crystalline alloy, amorphous alloy, etc. are used. Among these, amorphous alloys have an advantage over sendust, which is metal and granular and difficult to embed in grooves, in that it can be embedded tightly in grooves.

Next, the metal magnetic material is surface-polished until the non-magnetic material (16) is exposed.

As a result, as shown in FIG. 2(C), a metal magnetic thin film (19) is formed in the filling groove (17).

Next, the ferrite block (15) on which the metal magnetic thin film (19) is formed is cut at the position indicated by line a-a in FIG. 2(C).

In other words, a pair of magnetic core half-blocks (20) are formed by cutting at the position indicated by the a-a line.

(21) is produced.

And these magnetic core half-dead blocks (20), (2
1) Magnetic gap forming surface (20a) that becomes the abutting surface
, (21a), as shown in FIG. 2(D), winding grooves (22) and (23) for regulating the depth of the magnetic gear and for winding the coil are formed, respectively.

Next, these magnetic core half-vacant blocks (20), (2
Using the magnetic gap forming surfaces (20a) and (21a) of 1) as abutting surfaces, as shown in FIG. 2(E), the metal magnetic thin film (
19), (19) are aligned and joined together.

These magnetic core semi-dead blocks (20) and (21) may be joined by either glass fusion bonding or Au bonding.

These blocks (20
), (21) by inserting a glass rod into the winding grooves (22), (23) and heating and melting them. on the other hand,
In the case of Au bonding, the magnetic gap forming surface (20a)
.

After providing a base film made of Cr or Ti on (21a) and sputtering a metal film made of Au on top of this, a pressure of loMPa or higher is applied between these magnetic core semi-dead blocks (20) and (2+). 150°C ~ 30
Heat treatment is performed in a heat treatment atmosphere at 0° C. at a vacuum degree of about 10 −5 Torr.

As a result, when glass fusion is used, metal magnetic thin film (1
9), (19) A magnetic gap g is constructed using fused glass as the gap material. On the other hand, in the case of Au bonding, a magnetic gap g is formed using a metal film made of Au as the gap material.

Among these, these magnetic core semi-dead blocks (20).

(21) If Au bonding is used for bonding, the bonding is performed at a low temperature, so deterioration of the magnetic properties of the metal magnetic thin film (+9), especially in the case of a film made of an amorphous alloy, can be suppressed.

Next, cutting is performed at the positions indicated by middle line bb and line cc in FIG. 2(E) to cut out the head chip.

Finally, the Herad tip is cylindrically polished to ensure contact with the magnetic recording medium, completing the magnetic head shown in FIG. 1.

As mentioned above, in manufacturing the magnetic head of this example, as a method of laminating a metal magnetic thin film with a non-magnetic material, this example uses a method of sputtering and embedding a metal magnetic material into a groove formed in a non-magnetic material. Therefore, there is no need to perform a fitting operation between a metal magnetic material block and a non-magnetic material block that have been processed with highly accurate grooves or protrusions as in the past, and there is no need to manufacture the metal magnetic material block. Therefore, when manufacturing the magnetic head of this embodiment, it is possible to greatly simplify the manufacturing process, and at the same time, there is no need for high-precision machining, and it is expected that mass productivity will be greatly improved.

〔Effect of the invention〕

As is clear from the above description, in the magnetic head of the present invention, the metal magnetic thin film constituting the magnetic gap portion has a bond between the front portion and the back portion, which are bonded on the back side of the zero depth position of the magnetic gap. Since it is deeper into the back part than the interface, it is possible to ensure magnetic coupling between the metal magnetic thin film and the back part, and
By reducing the magnetic resistance, the electromagnetic conversion characteristics can be further improved.

Furthermore, in manufacturing the magnetic head of the present invention, the metal magnetic thin film is laminated with a non-magnetic material, and the metal magnetic material is formed by sputtering and embedding it in the groove provided in the non-magnetic material. The manufacturing process can be simplified and mass productivity can be expected to be significantly improved.

FIG. 2(E) is a perspective view showing a step of forming a winding groove, and FIG. 2(E) is a perspective view showing a step of joining a magnetic core half-block.

1, 2... ３　４　・・ 5, 6... 7 8 ・ ・ 9, 10・ +3 14 ・Front part ・Back part ・Metal magnetic thin film ・Non-magnetic material ··substrate ...Joining interface

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an example of a magnetic head to which the present invention is applied. 2(A) to 2(E) sequentially show the steps of manufacturing the magnetic head of the present invention, and FIG. 2(A) is a perspective view showing the step of bonding a non-magnetic material to a ferrite block. FIG. 2(B) is a perspective view showing the filling groove forming process, FIG. 2(C) is a perspective view showing the metal magnetic thin film forming process, and FIG. 2(I) is a perspective view showing the process of forming a groove for filling. Patent applicant Sony Corporation representative Patent attorney Akira Koike (and 2 others) Figure 2 (C
) Figure 2 (D) Figure 2 (△) 1st hole (Hoshosho (spontaneous) December 1990

Claims (1)

[Scope of Claims] A front part in which a metal magnetic thin film is sandwiched between non-magnetic materials and a magnetic gap is formed between the abutting surfaces of the metal magnetic thin film, and a closed magnetic path is formed with the front part made of ferrite. The front portion and the back portion have a bonding interface on the back side of the zero depth position of the magnetic gap, and the metal magnetic thin film of the front portion is further back than the bonding interface. A magnetic head that is characterized by being inserted into the inner side.