JPH0766495B2 - Magnetic head - Google Patents

Description

The present invention relates to a magnetic disk device, a magnetic head suitable for high density magnetic recording such as a VTR, and more particularly to a magnetic head suitable for a magnetic recording device using a high coercive force recording medium. Regarding heads.

BACKGROUND OF THE INVENTION As a magnetic head capable of sufficiently recording even on a recording medium having a high coercive force, many magnetic heads using a metal magnetic material having a high saturation magnetic flux density have been proposed. However, the magnetic head composed of a metal magnetic material has (1) poor characteristics in the high frequency region due to eddy-electric loss because it is a metal magnetic material.

(2) In order to avoid (1), there is a method of stacking a thin magnetic alloy via a non-magnetic insulating layer, but it is difficult to thin a magnetic alloy bulk material to 10 μm or less. Material selection is limited because some materials are difficult to produce. Furthermore, the work of bonding and laminating with an adhesive is difficult, and the production yield is very poor.

(3) Since the magnetic alloy is several steps inferior in wear resistance to ferrite, the life of the magnetic head is short. There were drawbacks such as.

Regarding a magnetic head made of a magnetic alloy and adapted to be used in combination with a high coercive force magnetic recording medium, for example, as shown in Japanese Patent Publication No. 54-3238, a magnetic head contacting a high coercive force magnetic recording medium is disclosed. In order to prevent the tip from being magnetically saturated, a magnetic alloy film having a large saturation magnetic flux density B _S is laminated in multiple layers by a well-known thin film forming method. Magnetic heads are known. An example of this type of magnetic head core is shown in FIG. Generally, one layer of core material is 3 ~
Magnetic thin films 10 and 0.1 made of Fe-Si-Al alloy with a thickness of 10 μm.
Nonmagnetic thin films made of SiO ₂ 11 having a thickness of 1 to 1 μm are alternately laminated to have a predetermined thickness. Here, 12 is an operating gear, and 13 is a window for coil winding.

However, although the above-mentioned magnetic alloy film multi-layered magnetic head has good characteristics, it is inevitable to manufacture each one by a butt-matching method, so that the productivity is low and the characteristics of products vary widely. There was a drawback. In addition, the wear resistance is also insufficient.

On the other hand, an amorphous magnetic alloy has been developed as a magnetic alloy having excellent wear resistance, and a magnetic head in which a magnetic circuit is composed of the amorphous magnetic alloy is disclosed in Japanese Patent Application Laid-Open No. 51-94211. Amorphous magnetic alloy is 900 to 1000 in Vickers hardness H _V, Permalloy (Ni-Fe alloy), hard in comparison to the H _V = 300 to 400 of the magnetic alloy such as Sendust (Fe-Si-Al alloy), It also has excellent wear resistance. However, it is insufficient when compared with ferrite.

In order to prevent the tip portion of the magnetic head contacting the high coercive force magnetic recording medium from being magnetically saturated, the saturation magnetic flux density B A magnetic alloy film ferrite composite magnetic head composed of a magnetic alloy having a large _S and other parts of the head core having a ferrite having a large magnetic permeability μ at a high frequency is disclosed in JP-A-51-140708. There is. For example, an example thereof is shown in FIG. That is, the vicinity of the operating gear 12 is formed of the magnetic film 10 having a high saturation magnetic flux density B _S , and this and the ferrite 14 are connected to form a magnetic circuit. Such a magnetic alloy film ferrite composite magnetic head is superior in wear resistance and remarkably good in productivity as compared with the former, but has the following drawbacks in terms of characteristics. For example, FIG. 2 (b) shows an enlarged view of the sliding surface of the magnetic head. When the magnetic alloy film 10 is multi-layered with the non-magnetic layer 11, the non-magnetic layer 11 exists in parallel with the operating gear 12. However, since an unnecessary pseudo gear trapping action occurs at that portion, a peculiar electromagnetic conversion characteristic is exhibited and the recording / reproducing characteristic is adversely affected. Further, also in the joint portion of the magnetic alloy film and the ferrite, if the magnetic characteristics of the two magnetic bodies are different, a similar pseudo-gating action occurs.

As a method for solving this problem, JP-A-54-9601
3, there is a structure disclosed in JP-A-56-169214. An example thereof is shown in FIG. 3 (perspective view) and FIG. 4 (plan view and side view). The magnetic head is obliquely crossed so that the joint between the magnetic alloy film 10 and the ferrite 14 does not have a parallel portion with the operating gear 12. By doing so, unnecessary pseudo gear gap action is eliminated and recording / reproducing characteristics are improved. However, no consideration is given to the constituent requirements and characteristics of the magnetic alloy film.

As described above, the magnetic head using the magnetic alloy has been improved variously, and the head characteristics, wear resistance, and productivity have been improved.

However, when a magnetic head is manufactured by forming a magnetic alloy by a thin film forming technique, there are advantages and disadvantages in various magnetic alloys, and the magnetic characteristics, physical characteristics, composition, and processing process of each are fully considered. The choices you make are necessary.

For example, if a material having a saturation magnetic flux density of 14 KG or more is selected for the amorphous magnetic alloy film, the crystallization temperature is low and the thermal stability is poor. However, it has an advantage that it has good compatibility with ferrite and high adhesion strength, and does not have a crystal structure, so that magnetic properties are not deteriorated little even when deposited on a substrate having a complicated shape.

On the other hand, for the polycrystalline magnetic alloy film, a material having a saturation magnetic flux density of 14 KG or more can be easily obtained. However, the adhesion strength with the ferrite is poor and peeling or cracking occurs. Also,
Since it has a columnar structure, when formed on a substrate having a complicated shape, there is a drawback that the magnetic characteristics deteriorate. However, it has a property of high adhesion strength with the amorphous magnetic alloy film.

[Object of the Invention]

The object of the present invention is to solve the above-mentioned conventional problems all at once, to eliminate the drawbacks thereof, and to make full use of the characteristics of the polycrystalline magnetic alloy film having a high saturation magnetic flux density and the amorphous magnetic alloy film. It is to provide a magnetic head suitable for high-density magnetic recording by constructing the core.

[Outline of Invention]

In order to achieve the above object, the magnetic head of the present invention is a magnetic head in which two magnetic cores face each other through an operating gap, and at least a part of the magnetic cores is made of a polycrystalline magnetic alloy and an amorphous magnetic material. At least one of the magnetic cores is made of an alloy, and the working gap surface of at least one of the magnetic cores is formed of the polycrystalline magnetic alloy, and the saturation magnetic flux density of the polycrystalline magnetic alloy is higher than that of the amorphous magnetic alloy.

Furthermore, the magnetic head of the present invention comprises a magnetic circuit composed of a polycrystalline magnetic alloy and an amorphous magnetic alloy, and is combined with a non-magnetic protective material having sliding resistance, or is not combined with the polycrystalline magnetic alloy. A magnetic circuit is composed of a crystalline magnetic alloy and ferrite. The structure is such that at least one of the actuating gear faces is formed of a polycrystalline magnetic alloy, and if an amorphous magnetic alloy and ferrite are present, the ferrite circuit is further connected in that order to form a magnetic circuit. Magnetic alloy B _S1 , amorphous magnetic alloy B _S2 , and if there is ferrite, it is composed of ferrite B _S3 , the size of which is B _S1 > B _S2
> B _S3 . Specifically, the saturation magnetic flux density B _S1 of polycrystalline magnetic alloy is 14KG or more, and the saturation magnetic flux density B _S2 of amorphous magnetic alloy is B _S2.
Is preferably 7 KG or more. The reason is that those having a saturation magnetic flux density of 5 to 5.5 KG can be easily achieved with Mn-Zn ferrite. When compounding with a magnetic alloy, if it is not more than 7 KG, the practical effect is small considering the productivity. The amorphous magnetic alloy film has excellent adhesion to ferrite, and because it does not have a crystal structure, it can easily follow complex shapes, and the deterioration of magnetic properties due to the shape is less than that of the polycrystalline magnetic alloy film. Suitable for forming the main magnetic path. However, when the amorphous magnetic alloy is selected in consideration of heat resistance and corrosion resistance, the saturation magnetic flux density is limited to 14 KG or less.

On the other hand, the saturation magnetic flux density of the polycrystalline magnetic alloy film is 14
Some are as large as KG to 20KG. However, when it is formed directly on ferrite, it has a large coefficient of thermal expansion, so it is thick film (5μ).
m or more), there are drawbacks such as peeling from the ferrite substrate and cracking of the film. Further, in the polycrystalline film formed by the thin film forming technique, crystals having a columnar structure grow in the film thickness direction, so that there is a problem that the magnetic characteristics are deteriorated at the bent portion of the substrate. On the other hand, the polycrystalline magnetic alloy film has an advantage that it has a high adhesion strength with respect to the amorphous magnetic alloy film. Therefore, the amorphous magnetic alloy film is used as a main magnetic path, and the saturation magnetic flux density near the operating gear is Ideally, the magnetic circuit is constructed as a large polycrystalline magnetic alloy film. Further, it is preferable that the protective material is made of a non-magnetic material having good wear resistance or a ferrite having high magnetic permeability. When the protective material is made of ferrite, a considerable part of the magnetic flux can be made to flow through the ferrite, which is also advantageous in that the magnetic resistance can be further reduced. As described above, according to the present invention, the magnetic head having an excellent structure is obtained by making the best use of the features of the polycrystalline magnetic alloy film and the amorphous magnetic alloy film.

It is preferable that the joints of each magnetic body should be diagonally crossed so as not to be parallel to the operating gears, but by selecting magnetic permeability μ equally, even if there are parallels, the pseudo-gearing action at the joints poses a problem. I knew it wouldn't be. The difference in magnetic permeability between the magnetic materials is, for example, 1000 to 3000 in the frequency domain, 1 to 5 MHz.
In the case of the value of μ, it is preferable to keep it within ± (20)%. The magnetic permeability of the magnetic alloy film can be controlled by a magnetic field for forming the film, or by a method such as heat treatment in a magnetic field later.

The polycrystalline magnetic alloy having a saturation magnetic flux density of 14 KG or more used in the present invention is mainly composed of Fe, Co or Fe-Co and Si, A
An alloy composed of one or more elements selected from the group consisting of l, Ti, V, Ta, Cr and Ni can be mentioned.
Further, a thin film having a high saturation magnetic flux density can be obtained by using Fe, Co or both of them and a compound such as N, C, P or the like. Also, Pt, Pd,
Saturation resistance can be secured by adding Au, Ag, Ru, Os, Rh, Ir or the like. Further, it is preferable to set the magnetostriction within a range of ± 1 × 10 ⁻⁶ .

On the other hand, the amorphous magnetic alloy film can be roughly classified into a metal-metalloid type and a metal-metal type, but the types of the alloys are very large. For example, the composition formula is M _a T _b X _c Z _d
, M is at least one element selected from the group of Fe, Ni, Co, and T is Mo, Cr, W, V, Nb, Ta, Mn, Al, Cu, Zn, Pb, S.
n, Pd, Pt, Au, Ag, Ru, Os, Rh, Ir, Be, Mg, La, Nd, Sm, Eu, Gd, Tb,
At least one element selected from the group of Dy, Er, Yb, Lu, and X is at least one element selected from the group of Zr, Ti, Y, Hf, Ge, Sb, Bi, Te Element Z is at least one element selected from the group of P, B, C, Si and N, and a + b + c
Under the condition of + d = 100, 0 ≦ b ≦ 95, 30 ≦ a + b ≦ 95,
The predominantly amorphous material satisfying 0 ≦ c ≦ 70 and 0 ≦ d ≦ 30 can be mentioned.

Among the above alloys, it is preferable to satisfy the conditions that the saturation magnetic flux density is 7 KG or more, the crystallization temperature is 400 ° C. or more, and the magnetostriction is within ± 1 × 10 ⁻⁶ .

Furthermore, examples of the protective core material include ceramic materials such as oxides, nitrides, carbides and borides, and glass in the case of a non-magnetic material. The main conditions are wear resistance and corrosion resistance, and a thermal expansion coefficient of 80 × 10 ^-7 to 140
Those in the range of × 10 ^-7 are preferable. When selected from magnetic materials, Mn-Zn ferrite and Ni-Zn ferrite can be mentioned. In particular, Mn-Zn ferrite is preferable because of its high magnetic permeability.

The magnetic alloy film is formed by a known thin film forming technique such as sputtering, vapor deposition, ion plating and plating. In particular, the amorphous magnetic alloy film is difficult to form due to vapor deposition or plating due to the element, and since it is a limited element, it is preferable to form it by the sputtering method.

In the structure of the magnetic circuit, when the protective core is made of a non-magnetic material, the main magnetic path is made of an amorphous magnetic alloy, and at least the vicinity including the operating gear surface is made of a polycrystalline magnetic alloy film. It is preferable that the amorphous magnetic alloy film has a thickness of about 5 μm to 100 μm, and the polycrystalline magnetic alloy film has a thickness of about 0.5 μm to 10 μm. If the thickness of the amorphous alloy is less than 5 μm, the magnetic path resistance will be high and the head characteristics will be poor.
If it exceeds μm, the area of the magnetic metal portion becomes large and the wear characteristics deteriorate, which is not preferable.

Further, if the thickness of the polycrystalline magnetic alloy film is less than 0.5 μm, the magnetic permeability characteristics are rapidly deteriorated, and if it exceeds 30 μm, the magnetic permeability in the high frequency region of 5 MHz or more is drastically decreased, which is not preferable either. Due to the head structure, the polycrystalline magnetic alloy film has a structure of 0.
It is used as 5 μm to 5 μm, or 5 μm to 30 μm. The former is suitable for a narrow track head having a track width of 10 μm or less, and the latter is suitable for a head having a track width of 10 μm or more.

On the other hand, when the protective core is a high-permeability ferrite, the main magnetic path is composed of ferrite or an amorphous magnetic alloy film and ferrite, and at least the vicinity including the operation gear surface is made of a polycrystalline magnetic alloy film. The thickness range of each alloy film is the same as described above.

Example of Invention

Hereinafter, the present invention will be described in detail with reference to examples. FIG. 5 is a plan view and a side view of the recording medium facing surface showing the basic structure of the magnetic head of the present invention. That is, the vicinity of the operating gear 20 is made of a polycrystalline magnetic alloy 21 having a high saturation magnetic flux density of 0.5 μm to 30 μm, and this is connected to the amorphous magnetic alloy 22 to form a magnetic circuit. For example, the polycrystalline magnetic alloy 21 is a well-known Fe-Si, Fe-Co-Si, Fe-N, Fe-C,
Fe-Ti and Fe-Al-Si alloys can be mentioned. The amorphous magnetic alloy 22 is made of known Co-Nb-Zr, Co-Mo-Zr, Co-W-.
Zr, Co-Ni-Zr, Co-Ti, Co-Zr, CO-Zr-B, Fe-Co-Si-
B etc. can be mentioned. 23 is a protective material, Mn-Zn
It is composed of a high magnetic permeability magnetic material such as ferrite or Ni-Zn ferrite, or a non-magnetic material such as ceramics or glass. For example, when the protective material 23 is a magnetic material, the magnetic circuit is composed of a polycrystalline magnetic alloy film, an amorphous magnetic alloy film and a protective material. When the protective material 23 is a non-magnetic material, the magnetic circuit is composed of a polycrystalline magnetic alloy film and an amorphous magnetic alloy film. In this case, the main magnetic circuit is composed of an amorphous magnetic alloy film, and in each case, at least the vicinity of the operating gear is composed of a polycrystalline magnetic alloy film.

FIG. 6 is a side view showing the structure of another magnetic head of the present invention. For example, the magnetic head shown in FIG.
When a high permeability magnetic material such as -Zn ferrite is used, the polycrystalline magnetic alloy film 21 and the amorphous magnetic alloy film 22 are separated by a coil winding window 24 as shown in FIG. Can be

Next, as shown in FIGS. 5 and 6, a polycrystalline magnetic alloy film is formed.
When the joint between 21, the amorphous magnetic alloy film 22 and the protective material 23 is parallel to the actuating gear 20, it is preferable that the magnetic permeability of each magnetic material be substantially the same. Then, the pseudo gear trap action at the joint can be reduced. Also,
When the magnetic permeability is different, it is preferable to increase the magnetic permeability of the magnetic body close to the operating gear.

7 and 8 are a plan view and a side view of a recording medium facing surface showing a structure of a magnetic head according to another embodiment of the present invention.

FIG. 7 shows a structure in which the amorphous magnetic alloy film 22 is formed on the protrusion of the protective material 23 so that the joint boundary does not have a parallel portion with the operating gear 20. By doing so, even if the amorphous magnetic alloy film is a multi-layered magnetic film in which a non-magnetic material is multilayered, the non-magnetic intermediate layer does not form a parallel portion with the actuating gap 20, so that the pseudo-gating action is avoided. You can And, the polycrystalline magnetic alloy film 21 is 0.5 μm to 5 μm in the vicinity of the operating gear.
μm is formed. The polycrystalline magnetic alloy film can be improved in recording and reproduction characteristics by being subjected to sputtering in a magnetic field or heat treatment in a magnetic field to increase the magnetic permeability in a direction perpendicular to the recording medium.

FIG. 8 is a plan view of a magnetic head showing another embodiment of the present invention. The present embodiment is a magnetic head constructed so that all the joints of the polycrystalline magnetic alloy film 21, the amorphous magnetic alloy film 22 and the protective material 23 do not have a parallel portion with the operating gap. With such a structure, it is possible to avoid the influence of the pseudo-gap action at the joint even if the magnetic permeability values of the magnetic materials are different. At this time, the facing surface of the operating gear is composed of at least a polycrystalline magnetic alloy film. The thickness of the polycrystalline magnetic alloy film varies depending on the track width, but it is necessary to be about 5 μm to 30 μm, and it is necessary to be thicker than the film thickness used for the magnetic head of FIG.

In each of the above examples, in the absence of the polycrystalline magnetic alloy film, the coercive force H _c was about 3 dB lower than the magnetic head recording / reproducing sensitivity with respect to the recording medium of 16000e, and the protective material was Mn-Zn ferrite. In addition, when the amorphous magnetic alloy film was not present, the polycrystalline magnetic alloy film tended to peel from the ferrite, which was not preferable.

An example of the method for producing the magnetic head of the present invention will be described in detail below with reference to examples.

FIGS. 9 (A) to 9 (I) are explanatory views of each step of the first manufacturing method of the present invention.

i) and FIG. 9 (a) show a step of forming a coil winding groove 32 on the surface 31 which is the gear butting surface of the protection block 30 made of high magnetic permeability ferrite. The surface 31 should be mirror-polished in advance. Here, as the high magnetic permeability ferrite, for example, Mn-Zn ferrite having a saturation magnetic flux density of 5 KG and a relative magnetic permeability of 1500 is used. At least the tip of the coil winding groove 32 is inclined, and θ ₁ is 20 ° to 70 °, preferably 30 °.
It is good to set it to ~ 60 °. Further, it is effective to form a magnetic alloy film if the rear part (not shown) is also inclined.

ii), the step shown in FIG. 9 (b) goes straight to the coil winding groove obtained in the step (a), and is adjacent to the surface 31 which becomes the gear butting surface, leaving a projection narrower than the track width. Two
This is a step of providing a plurality of sets of grooves, each of which is a set of grooves 33, 33 ', in parallel. A metal bond grindstone or a resin bond grindstone having a V-shaped or U-shaped tip is used for the groove, and the groove is processed by a high-speed dicer or the like. Here, the angle θ ₂ (shown in FIG. 9C) of the protrusion is selected to be 30 ° to 120 °. The flat portion 34 left between the grooves of each set is subjected to polishing in a later step, for example, a step corresponding to FIG. 9 (e) and FIG. 9 (h).
It is a reinforcing portion of the metal magnetic alloy when the blocks are joined in the process corresponding to (3) and serves as a reference surface.

iii), FIG. 9 (c) shows an enlarged side surface of the grooves 33, 33 'processed in the step shown in FIG. 9 (b) (hereinafter, referred to as FIG. 9 (b),
Steps corresponding to FIG. 9C and the like are referred to as step (B) and step (C)). Step (c) is a step of depositing an amorphous magnetic alloy film 35 and a polycrystalline magnetic alloy film 36 having a saturation magnetic flux density higher than that of ferrite by spattering on the entire surface of the gear butting surface. The amorphous magnetic alloy film is, for example,
A CO ₈₄ Nb ₁₃ Zr ₃ alloy (atomic%) having the following characteristics is used.

Saturation magnetic flux density B _S2 ; 9.5KG Magnetostriction γ _S ; -2 × 10 ^-7 Crystallization temperature T _X ; 525 ℃ Coercive force H _C ; 0.15Oe Anisotropic magnetic field H _K ; 8Oe 5MHz relative permeability; 2000 Film thickness The RF sputtering device was used for the 30 μm sputtering process under the following conditions.

Sputter power P _f ; 300W Argon pressure P _Ar ; 5 × 10 ^-3 Torr Electrode distance d; 50mm Substrate temperature t; 80 ℃ Other amorphous magnetic alloys are represented by Co-Fe-Si-B system. Well-known metal-metalloid alloys, Co-Zr, Co-T
Well-known metal-metal alloys such as i, Co-Mo-Zr are used.

Next, the saturation magnetic flux density B _S3 is 14K on the amorphous magnetic alloy film 35.
A polycrystalline magnetic alloy film 36 of G or more is deposited by sputtering. Polycrystalline magnetic alloy is, for example, Fe-4.5% S
i-5% Ru (weight%) having the following characteristics is used.

Saturation magnetic flux density B _S3 ; 17KG Magnetostriction γ _S ; 1 × 10 ^-6 Coercive force H _C ; 0.8Oe Anisotropy magnetic field H _K ; 10Oe 5MHz relative permeability; 1800 Thickness; 10μm Spattering is performed under the following conditions. It was

Sputter power P _f ; 500 W Argon pressure P _Ar ; 2 × 10 ^-2 Torr Electrode distance d; 25 mm Substrate temperature t; 350 ℃ In addition to this, as the polycrystalline magnetic alloy film 36, Fe-Si based
Fe-Co-Si system, Fe-Ti system, Fe-Al-Si system and Fe-N
Alloys typified by alloys and Fe-C alloys are used. Other deposition methods are possible, such as vacuum deposition, ion plating, chemical vapor deposition, and plating, but the sputtering method is suitable because of the drawbacks such as limited metals and large compositional variations. Further, the sputtering method is suitable for the method of the present invention because it has high adhesion strength and has the advantage that it can easily wrap around the groove.

The thickness t ₁ of the amorphous magnetic alloy film 35 is preferably 10 to 50 μm in order to form a magnetic circuit. On the other hand, the thickness t ₂ of the polycrystalline magnetic alloy film 36 needs to be the thickness that constitutes the track width t _w shown in the step (e). Suitably 10 to 30 μm
Is. In particular, the polycrystalline magnetic alloy film can have improved magnetic characteristics by forming a non-magnetic film or a magnetic film as an intermediate layer.

iv), step (d) is a non-magnetic material 37 to the extent that at least the remaining groove is filled on the metal magnetic film obtained in step (c).
Is the step of filling. The non-magnetic material 37 is made of glass, ceramic inorganic adhesive or hard resin. Glass is suitable in terms of stability. A glass material having a softening point below the crystallization temperature of the amorphous magnetic alloy is selected. It is preferable to select a working temperature of 50 ° C. or lower than the crystallization temperature.

Further, it is preferable to form SiO ₂ , Al ₂ O ₃ or the like in a thickness of 1 to 5 μm in order to protect the magnetic alloy film before filling with the non-magnetic material. By doing so, it is possible to prevent the reaction with the magnetic alloy film when the glass is filled.

v) and the step (e) are the steps of removing the unnecessary portions of the non-magnetic material 37 and the polycrystalline magnetic alloy film 36 of the block obtained in the step (d) to expose the gap forming surface. The removal method is carried out by grinding and polishing, and the final finish is a mirror surface in order to obtain a gear butt surface. Mirror polishing is performed until the track width t _w is obtained. The gear butting surface is formed of a polycrystalline magnetic alloy film.

vi) and FIG. 9 (f) are perspective views of one core block having the coil winding groove obtained in the step (e). The other core block may not have the coil winding groove. The step (f) is a step of forming a non-magnetic material such as SiO ₂ or glass in a thickness of 0.1 to 0.3 μm (not shown) on the gear forming surface of at least one of the pair of core blocks to form a gear forming film. .

vii), step (g) is a step in which the abutment surfaces of the pair of blocks 30 and 30 'are abutted so that their track portions are in contact with each other, and they are joined and integrated while heating and pressing.
In this case, if the non-magnetic material 37 filled in the groove is made of glass, the joining is performed by the glass of each other. When resin or ceramic material is used, a part of the coil winding window and the rear joining are separately provided. It is made of resin or the like by providing a cutout groove in the portion.

viii) and FIG. 9 (h) show the magnetic tape sliding surface of the joining block 38 obtained in step (g). The step (h) is a step of cutting a plurality of composite magnetic heads so that a required core width T shown by a dotted line is centered around the track width.
In some cases, it is cut at an azimuth angle. In this way, a narrow track magnetic head core having the structure shown in FIG. 9 (i) showing the sliding surface of the magnetic tape is obtained. By winding a coil around this, the magnetic head of the present invention can be obtained.

In the method of the present invention, the coil winding groove processing in the step (a) may be performed after the work point (e).

Next, an example of suitably controlling the magnetic permeability of the magnetic alloy film in the present invention will be described. FIG. 10 is a plan view showing the recording medium facing surface of the magnetic head of the present invention. The symbol shown is number 7.
The symbols are the same as those shown in FIG. That is, 20 is an operating gear, 21 is a polycrystalline magnetic alloy, 22 is an amorphous magnetic alloy, 23 is a protective material, and 25 is a non-magnetic filler. Here, the protective material 23 is Mn-Zn ferrite. Amorphous magnetic alloy film 22
Of Co-Mo-Zr having a saturation magnetic flux density B _S2 of 8 KG was formed to a thickness of 30 μm by the sputtering method. Permeability is controlled by well-known spattering in a rotating magnetic field or heat treatment in a known unidirectional magnetic field to control the magnetic anisotropy, and the relative magnetic permeability at 1 MHz to 5 MHz is 2000 to 30
I set it to 00. And the polycrystalline magnetic alloy film 21 has a saturated magnetic flux density.
Fe—Al—Si having a B _S3 of 11 KG was sputtered in a magnetic field in the track width direction (arrow in FIG. 10) to form 0.5 to 5 μm. That is, the easy magnetization axis was formed in the track width direction, and the relative magnetic permeability in the direction perpendicular to the recording medium facing surface was 2000. In this way, by making the magnetic flux in the vicinity of the operating gear strong and steep, the recording and reproducing effects were significantly improved.
The magnetic head of the present invention has a structure suitable for high density magnetic recording. Furthermore, the structure is such that suitable recording and reproduction can be performed on the perpendicular magnetic recording medium.

〔The invention's effect〕

As described above, the magnetic head of the present invention has the following effects as compared with the conventional magnetic head.

(1) high saturation can also sufficiently recorded in the magnetic flux density (or 14kg) multi recording medium of the crystalline magnetic alloy film actuated Giyatsupu for constituting the vicinity of a high coercive force (H _c 1500 Oe), the polycrystalline Since the magnetic circuit is composed of an amorphous magnetic alloy film that does not have a crystalline structure and is connected to the magnetic alloy film, there is no deterioration in magnetic characteristics even in a ring shape, and a structure that improves recording and reproducing efficiency is provided. There is.

(2) When a polycrystalline magnetic alloy film is formed on the ferrite, the adhesion strength is poor and peeling or cracking occurs, whereas the amorphous magnetic alloy film is not formed on the ferrite and the polycrystalline magnetic alloy film. Good adhesion strength and excellent head structure. Therefore, it is also excellent in mass productivity.

(3) Since the head core has a magnetic alloy having a large saturation magnetic flux density at the tip of the head, where magnetic saturation is a problem, a sharp magnetic flux can be generated, and the structure is suitable for high density recording. I'm running.

[Brief description of drawings]

1, FIG. 2 (a), (b), FIG. 3, and FIG. 4 are a perspective view, a plan view and a side view of a conventional magnetic head, and FIG. 5 is a magnetic head in an embodiment of the present invention. And FIG. 6 is a side view of a magnetic head according to another embodiment of the present invention, and FIGS. 7 and 8 are plan views and side views of a magnetic head according to still another embodiment of the present invention. Figure, Figure 9 (a) ~
(I) is an explanatory view of each step in one embodiment of the magnetic head manufacturing method of the present invention, and FIG. 10 is an enlarged plan view showing a recording medium facing surface of the magnetic head in another embodiment of the present invention. 20 ... Actuating gear, 21 ... Polycrystalline magnetic alloy film, 22 ... Amorphous magnetic alloy film, 23 ... Protective material, 24 ... Coil winding window, 25 ...
Non-magnetic filler.

Front page continuation (72) Inventor Hori Saito 1-280 Higashi Koigakubo, Kokubunji, Tokyo Inside Hitachi Central Research Laboratory (72) Inventor Toshihiro Kudo 1-280 Higashi Koigakubo, Kokubunji, Tokyo Hitachi Central In the laboratory (56) Reference JP-A-58-155513 (JP, A) JP-A-59-116918 (JP, A)

Claims (5)

[Claims] 1. A magnetic head in which two magnetic cores face each other across an operating gap, and at least a part of the magnetic cores is composed of a polycrystalline magnetic alloy and an amorphous magnetic alloy, and at least one magnetic core. A magnetic head having a saturated magnetic flux density of the polycrystalline magnetic alloy larger than that of the amorphous magnetic alloy. 2. A magnetic head according to claim 1, wherein a magnetic circuit is composed of a polycrystalline magnetic alloy and an amorphous magnetic alloy, and a non-magnetic protective material is further provided. 3. A magnetic head according to claim 1, wherein a magnetic circuit is composed of a polycrystalline magnetic alloy, an amorphous magnetic alloy and ferrite. 4. A magnetic circuit is formed by connecting at least one working gap surface with a polycrystalline magnetic alloy and connecting an amorphous magnetic alloy and a ferrite in this order, and the saturation magnetic flux density thereof is a polycrystalline magnetic alloy B. _S1 , amorphous magnetic alloy B _S2 , ferrite
The magnetic head according to claim 3, wherein the magnetic head comprises B _S3 , and the size thereof is B _S1 > B _S2 > B _S3 . 5. The saturation magnetic flux density B _S1 of the polycrystalline magnetic alloy is 14K.
G or more, and the saturation magnetic flux density B _S2 of the amorphous magnetic alloy is 7 KG or more, Claims 1, 2,
The magnetic head according to claim 3 or 4.