JPS61287018A - Magnetic head - Google Patents

Abstract

PURPOSE:To disperse strain remaining in a magnetic head and to suppress the generation of cracks, etc. by interposing nonmagnetic films between a thin ferromagentic metallic film and ferromagnetic oxide positioned between a winding groove and back gaps. CONSTITUTION:The thin ferromagentic metallic film 13 which is a high magnetic permeability alloy, for example, Fe-Al-Si alloy film is deposited and formed by a vacuum thin film forming technique, continuously from the front gap forming surfaces to the back gap forming surfaces, on the thin ferromagnetic film forming surfaces 11a, 12a formed by diagonally cutting out the joint surfaces of magnetic core halves 11, 12 formed of the ferromagnetic oxide. The blet-like nonmagnetic films 17a, 17b consisting of the soft nonmagnetic material are provided at the boundaries of the thin ferromagnetic metallic film 13 positioned between the winding groove 16 and the back gap forming surfaces 11c, 12c, and the magnetic core halves 11, 12. A slightly curved part is thereby made to the film 13, by which the strain is dispersed and the generation of the cracks, etc. is suppressed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a magnetic head, and in particular to a so-called composite magnetic head in which the vicinity of the magnetic gap is formed of a ferromagnetic metal thin film. .

[Summary of the invention]

The present invention comprises a magnetic core half made of a ferromagnetic oxide and a ferromagnetic metal thin film deposited on the ferromagnetic metal thin film forming surface of the magnetic core half so as to extend from the front gap to the back gap. In the magnetic head in which the magnetic gap is formed by abutting the ferromagnetic metal thin films, 8! is located between the winding groove and the back gap. ! By interposing a nonmagnetic film between a magnetic metal thin film and a ferromagnetic oxide, strain remaining in the magnetic head is dispersed, and the occurrence of cranks and the like is suppressed.

[Conventional technology]

For example, in magnetic recording and reproducing devices such as VTRs (video tape recorders), the recording signal density is increasing, and in response to this high density recording, Fes CO% N is added to magnetic powder as a magnetic recording medium. So-called metal tapes using ferromagnetic metal powders such as ferromagnetic metal powders, and so-called vapor deposition tapes in which ferromagnetic metal materials are deposited on a base film by vapor deposition, have come into use. Since this type of magnetic recording medium has a high coercive force Hc,
For example, head materials for magnetic heads used for recording and reproduction are also required to have a high saturation magnetic flux density BS.
Ferrite materials, which have conventionally been widely used as magnetic head materials, have a low saturation magnetic flux density B3, and permalloy has problems in wear resistance.

Therefore, a composite magnetic head has been proposed in which a ferromagnetic metal thin film is deposited on a non-magnetic substrate such as ceramics, and this is used as a track part, but in this type of magnetic head, the magnetic path is Since it is composed only of a thin ferromagnetic metal thin film, it has a large magnetic resistance, which is unfavorable in terms of efficiency.
Furthermore, since the ferromagnetic metal thin film is formed using a vacuum thin film forming technique that has an extremely slow film growth rate, there are problems such as the time required to fabricate the magnetic head.

Alternatively, a composite magnetic head has been proposed in which the magnetic core portion is made of a ferromagnetic oxide such as ferrite, and a ferromagnetic gold 111iI film is coated on the magnetic gap forming surface of each magnetic core portion. Since the magnetic path and the metal thin film are located in a direction perpendicular to each other, there is a risk that eddy current loss will occur and the reproduction output will decrease, and a pseudo gap is formed between the magnetic core part and the metal thin film, There are problems such as insufficient reliability.

Therefore, the applicant of the present application previously proposed in Japanese Patent Application No. 58-250988 a composite magnetic head suitable for high-density recording on a magnetic tape having a high coercive force, such as a metal tape. As shown in FIG. 11, this magnetic head has a pair of magnetic core halves (101) and (1) formed of ferromagnetic oxide such as Mn-Zn ferrite.
02) are each diagonally cut out to form a ferromagnetic metal thin film forming surface (103).

(104) is formed, and this ferromagnetic metal thin film forming surface (10
3) Ferromagnetic metal thin films such as sendust are formed on (105) and (106) using vacuum thin film formation technology on (104).
These ferromagnetic metal thin films (105),
(106) is brought into contact with the magnetic gap (107).
), and low melting point glass (10B), (
109) or high melting point glass (11G), (11
1), and has excellent characteristics in terms of reliability, magnetic properties, wear resistance, etc.

[Problem that the invention seeks to solve]

By the way, in the magnetic head configured as described above,
In particular, due to the difference in thermal expansion coefficient between the ferromagnetic metal thin film that is deposited by sputtering and other methods and becomes the track portion of this magnetic head, and the ferromagnetic oxide to which this film is deposited, internal stress is generated during film formation. There was a risk that additional distortion would occur. If such distortion remains, it causes the ferromagnetic metal thin film to peel off, crack, crack, etc. in subsequent processing steps, and is a major cause of lowering the manufacturing yield of this magnetic head.

Therefore, the present invention has been proposed in view of the above-mentioned conventional circumstances, and it disperses the strain caused by the difference in coefficient of thermal expansion during the formation of a ferromagnetic metal thin film, eliminates the occurrence of cranking, and provides excellent reliability. The purpose is to provide a magnetic head with good yield.

Means for Solving Problem C] To achieve this object, the magnetic head of the present invention includes a magnetic core half made of a ferromagnetic oxide and a front surface on a surface of the magnetic core half on which a ferromagnetic metal thin film is formed. In a magnetic head consisting of a ferromagnetic metal thin film deposited extending from the gap to the back gap, and in which the magnetic gap is formed by butting the ferromagnetic metal thin films, the magnetic head has a magnetic head that is When the ferromagnetic metal thin film forming surface and the magnetic gap forming surface are tilted at a predetermined angle, the abutted ferromagnetic metal thin films continue in a substantially straight line, and the magnetic field located between the winding groove and the bank gap is It is characterized in that a nonmagnetic film that disperses strain is interposed between the magnetic metal thin A thin film and the ferromagnetic oxide.

[Effect]

In this way, by providing a nonmagnetic film between the ferromagnetic metal thin film and the ferromagnetic oxide located between the winding groove and the back gap, a slight bend is created in the ferromagnetic metal thin film, causing distortion. is distributed.

(Example〕 Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an external perspective view showing an example of a composite magnetic head to which the present invention is applied, and FIG. 2 is an enlarged plan view of essential parts showing the magnetic tape contacting surface thereof.

In this magnetic head, a magnetic core half (11).

(12) is formed of a ferromagnetic oxide, such as Mn-Zn ferrite, and these magnetic core halves (11).

The ferromagnetic thin film forming surface (lla), which is obtained by cutting out the bonding surface of (12) diagonally, and (12a) are made of a high magnetic permeability alloy, such as Fe- A ferromagnetic metal thin film (13), which is an Al-3i alloy film, is deposited using a vacuum thin film forming technique. Then, these pair of magnetic core halves (1
1) and (12) are butted together via a gap material such as S i O*, and the contact surface of the ferromagnetic metal thin film (13) is configured to form a magnetic gap g having a trunk width TW. Here, each of the magnetic core halves (11),
The ferromagnetic metal thin film (13) deposited on (12) is
When viewed from the magnetic tape contact surface, the bonding surface (10
) at an angle of θ.

Further, in the vicinity of the formation surface of the magnetic gap g, that is, on both sides of the magnetic gap g on the surface facing the magnetic tape, a non-magnetic film is provided to regulate the track width and prevent wear of the ferromagnetic metal FiI film (13). Material (14).

(15) is melt-filled.

In addition, in this example, the magnetic core half (11)
, (12) The track width regulating groove (llb
).

(12h) is formed such that the shape of the interface between the non-magnetic material (15) and the ferromagnetic oxide is curved. For example, when the magnetic head is viewed from the surface facing the magnetic tape, the shape of the interface is The track width regulating grooves (11b) and (12b) are cut with a curved surface having a substantially arc shape.
The ferromagnetic oxide facing the ferromagnetic oxide and the ferromagnetic metal thin film facing the ferromagnetic oxide (
In addition to securing the distance from the magnetic core halves (11) and (12), the symmetrical balance of this groove minimizes the stress on the ferromagnetic oxide during processing.
) may be prevented from occurring.

Furthermore, in the magnetic head of the present invention, the back sides of the magnetic core halves (11) and (12), that is, the Ja striped grooves 16) and the back gap forming surface (llc)
, (12C) ferromagnetic metal thin film (13
) and a magnetic core half (11) made of ferromagnetic oxide,
A strip-shaped nonmagnetic film (17a) made of a soft nonmagnetic material is placed at the interface of (12).

(17b) is provided.

These non-magnetic films (17a) and (17b) disperse strain caused by the difference in thermal expansion coefficient between the aforementioned ferromagnetic metal thin film (13) and the magnetic core halves (11) and (12) made of ferromagnetic oxide. As the material, metal materials such as AE, Ti, Cu, Au, Ag, Cr, and Ni can be used. In particular, plastic deformation to alleviate strain and
From the viewpoint of being able to absorb /l, soft metals such as Ti and Au, which contain few added elements, are more preferable.

Although the nonmagnetic films (17a) and (17b) are formed as strip-shaped films here, they may be continuous films.

In this way, the non-magnetic film (17a
) and (17b), a slight bend is formed in the ferromagnetic metal thin l1l (13), the strain is dispersed, and the occurrence of cranks is suppressed.

Furthermore, since the non-magnetic films (17a) and (17b) are provided only on the back gap side of the winding groove (16), the ferromagnetic metal i+ on the front gap side, which contributes to recording and reproduction, is (13) is not affected in any way, and the electromagnetic conversion characteristics etc. are not deteriorated.

On the other hand, the ferromagnetic thin film forming surface (lla), (12a
) and the magnetic gap forming surface (10) are 20
It is preferable to set the angle within the range of ~80 degrees.If the angle is less than 20 degrees, the crosstalk from adjacent tracks will become thick (so it is preferable to set the angle to 30 degrees or more. In addition, if the above-mentioned inclination angle is set to 90°, the wear resistance will be poor, so it is better to set it to about 80° or less. Also, if the inclination angle is set to 90", the magnetic gap will be formed in the vicinity of the magnetic gap g. 1 liter of the above-mentioned ferromagnetic metal thin film (
13) It is necessary to form a film with a thickness equal to the track width TW, and when forming a thin film using vacuum thin film formation technology, it takes a lot of time and the film structure becomes non-uniform. So it's not desirable.

That is, since the film thickness t of the ferromagnetic metal thin lI% (13) deposited on the magnetic core halves (11) and (12) may be t=Twsin θ, the track width is 7'w. It is not necessary to deposit a film with a corresponding thickness, and the time required for manufacturing the head can be shortened. Here, Tw is the track width and θ
is the surface (lla) on which the ferromagnetic thin film is formed.

(12M) and the magnetic gap forming surface (10).

The material of the ferromagnetic metal 1111 (13) is a ferromagnetic amorphous metal alloy, a so-called amorphous alloy (
For example, an alloy consisting of one or more elements of Fe + Ni * Co and one or more elements of P, C, B, 310,
Or A1 with this as the main component. Ge, Be.

Sn, In, Mo, W, Ti, Mn, Cr, Zr.

1 (metal-metalloid amorphous alloys such as alloys containing f, Nb, etc., or Go, metal-metal amorphous alloys whose main components are transition elements or rare earth elements such as If, Zr), Fe-Aj! -3i-based alloy Sendust alloy, Fe-AJ! type alloys, Fe-3i type alloys, Fast-Co type alloys, permalloy, etc. can be used, and the coating methods include flash evaporation, vacuum evaporation, ion blasting, sputtering, cluster ion beam method. Vacuum thin film forming technology, typified by, etc., is adopted.

When using the above Fa-Affi-3i alloy, the composition range of its main component Fe*Ajr9x is as follows: jl content is 2 to 10% by weight, Si
It is preferable that the content of is 4 to 15% and the balance is Fe, that is, the Fe-Ag-3i alloy is
c represents the weight ratio of each component), it is desirable that the composition range is 70≦a95 2≦b≦10 4≦C≦15. On the other hand, if it is too large, the magnetic properties of the Fe-'Al-3i alloy will deteriorate.

It is also possible to replace a part of the Fe with at least one of Co and Ni.

The saturation magnetic flux density can be increased by replacing a portion of Fe with Co. In particular, 40% by weight of Fe was replaced by C
The maximum saturation magnetic flux density can be obtained by replacing with o. The amount of Co substitution is 0 to 60% by weight with respect to F@.
It is preferable that it is within the range of .

By replacing a portion of the Fe with Ni, the magnetic permeability can be maintained at a high level without decreasing the saturation magnetic flux density. The amount of Ni to be replaced with Fe is 0 to
It is preferably within the range of 40% by weight.

Furthermore, various elements may be added as additives to the above-mentioned Fe-An-3i alloy in order to improve corrosion resistance and wear resistance.As the elements used as the above-mentioned additives,
IIIa group elements including lanthanum series such as Sc, Y, La, Ce, Nd, Gd, Na group elements such as Tt, Zr, Hf, Va group elements such as V, Nb, Ta, Cr, Mo, W etc. Via group elements, ■A group elements such as Mn, Tc, Rs, Cu
, Ag.

Group Ib elements such as Au, Ga, In, Ge, Sn.

sb etc.

By the way, when using the above-mentioned Fe-Al1-3t alloy, the ferromagnetic metal thin film (13) has a columnar structure whose growth direction is aligned with the ferromagnetic thin film formation surface (12) of the magnetic core halves (11), (12). lla), (12a) is preferably applied so as to be inclined at a predetermined angle λ, that is, an angle of 5° to 45°.

In this way, the ferromagnetic metal obtained by growing the ferromagnetic metal thin film (13) at a predetermined angle with respect to the normal direction of the ferromagnetic thin film forming surface (Ila), (12a) The magnetic properties of the thin film (13) are stable and excellent, and the quality and performance of the resulting magnetic head are therefore improved.

By the way, in this example, the ferromagnetic metal thin film (13) is formed as a single layer by vacuum thin film formation technology, but for example, S i Oz+ T a gos, A j! z
03゜Multiple layers may be formed via a highly wear-resistant film such as Z r Ox, S j sNa, etc. In this case,
The number of laminated ferromagnetic metal thin films can be set arbitrarily.

Next, in order to clarify the structure of the magnetic head of the above embodiment, a manufacturing method thereof will be described.

In order to manufacture the magnetic head of the above embodiment, first, as shown in FIG. The joint surface of the oxide substrate (20) when the magnetic core halves are brought together is cut with a cross section of approximately V using a rotary grindstone or the like.
A plurality of letter-shaped first kerfs (21) are formed in parallel over the entire width to form a ferromagnetic thin film forming surface (21a). In addition,
The ferromagnetic thin film forming surface (2-1a) is formed as a slope so as to be inclined at a predetermined angle θ with respect to the upper surface (20a) corresponding to the magnetic gap forming surface of the ferromagnetic oxide substrate (20). θ is here set to approximately 45°.

Then, as shown in Fig. 4, this ferromagnetic oxide substrate (
20) The upper surface (20a) and the ferromagnetic metal thin film forming surface (
21a), the entire surface is made of soft material, in this example A
A thin film of 1 is deposited as a nonmagnetic film (22) by means such as vapor deposition.

After forming the non-magnetic film (22) over the entire surface in this way, as shown in FIG. The strip portions (22a) and (22b) are left.

In addition, at this time, the ferromagnetic gold rl & thin film forming surface (21a) 2
The band-shaped portion (22a) of the non-magnetic film (22) remaining in the
Etching is performed so that it is located on the back gap side, that is, on the bank gap formation surface (20b) side of the substrate (20), with respect to the formation position of the winding groove, which will be described later.

Next, as shown in FIG. 6, a Fe-Al-3t alloy, an amorphous alloy, etc. is applied by sputtering, ion blasting, or vapor deposition over the entire surface of the substrate (20) on the nonmagnetic film (22). A ferromagnetic metal thin film (23) is formed using a vacuum thin film forming technique such as . At this time, the above substrate (20
) is coated with a non-magnetic film (22) in advance on the upper surface (20a).
is formed, stress caused by the difference in thermal expansion coefficient between the substrate (20) and the ferromagnetic metal thin film (23) is directly applied to the substrate (23).
20), the distortion is relaxed and dispersed. Furthermore, a strip portion (22a) of the non-magnetic film (22),
(22b) Ferromagnetic gold IIWI coated on top (
23) is adhered with a slight bend due to the step formed by the band-shaped portions (22a) and (22b), so that the strain is dispersed in this portion.

Next, as shown in FIG. 7, a ferromagnetic metal thin film (23) is formed.
A non-magnetic material (
24), the upper surface (20a
) is surface ground and the excess ferromagnetic metal ti! on its top surface (20a) is removed. 1la (23) and the nonmagnetic film (22) are removed.

Furthermore, the end surface of the ferromagnetic metal thin B (23) to be deposited on the ferromagnetic thin film forming surface (21a) is exposed on the upper surface (20a) of the substrate (20) by smoothing the surface (having good smoothness). Since almost no strain is applied to the substrate (20) due to the action of the non-magnetic film (22), the non-magnetic material (24)
Cracks do not occur during melt filling or surface grinding.

Next, as shown in FIG. 8, the ferromagnetic metal thin film (23
) is formed adjacent to the ferromagnetic thin film forming surface (21a) on which the ferromagnetic thin film is deposited, and a first cut groove (21) is formed so as to slightly overlap the negative side edge (21b) of the first cut a (21). A second groove (25) is cut in parallel with the substrate (20).
Mirror finishing is applied to the upper surface (2Qa) of, as a result,
The track width Tw is regulated so that a magnetic gap is formed only by the ferromagnetic metal thin film (23).

Note that the groove shape of this second kerf (25) may be a simple V-shape, but for example, it may be polygonal or semicircular in cross section, and the inner wall surface of this kerf (25) may be formed in two stages. Alternatively, by making the shape more bent than that, it is possible to secure a certain distance between the ferromagnetic oxide and the ferromagnetic metal thin film. With such a groove shape, it is possible to reduce crosstalk components caused by reproducing long wavelength component signals, and furthermore, the track width - the end face of the dividing groove part is in a direction different from the azimuth angle of the magnetic gap. Because it is tilted, crosstalk from adjacent or adjacent tracks is reduced.

Furthermore, after forming the ferromagnetic metal thin film (23) on the ferromagnetic thin film formation surface (21a), a second groove (25) for regulating the track width is formed. Therefore, by adjusting the cutting position of this second kerf (25), it is possible to manufacture the trunk width with high precision. In addition, a magnetic head having a shape that allows magnetic flux to pass through the ferromagnetic oxide can be manufactured with high yield, and the output can also be increased, which is advantageous in terms of productivity, reliability, and manufacturing cost.

As shown in FIG. 9, the first groove (21) and Groove processing is performed in the direction perpendicular to the second kerf (25), and the winding groove (
26) and H grooves (27) are formed, and the ferromagnetic oxide substrate (
30), the cutting position of the winding groove (26) is set closer to the front gap than the position where the strip portion (22a) of the non-magnetic film (22) is attached.

Subsequently, a gap spacer is attached to at least one of the upper surface (20a) of the substrate (20) and the upper surface (30a) of the substrate (30), as shown in FIG.
These substrates (2G) and (3G) are bonded and arranged so that the ferromagnetic metal thin films (23) are butted against each other.

Then, at the same time as these substrates (20) and (30) are fused together with glass, the second kerf (25) is filled with the non-magnetic material (28). In addition, as the gap spacer, S i 011 Z r 0tlTa
TOS+Cr etc. are used. In addition, in this manufacturing process, the non-magnetic material (28) is added to the second groove (25).
The filling is not done at the same time as the fusion of the substrates (20) and (30), but for example, in the step shown in FIG. In the process shown in FIG. 10, only glass fusion may be performed.

After cutting out a plurality of head chips by slicing at the positions of lines A-A&lI and A''- in Figure 1O, the magnetic tape sliding surface is cylindrically polished to form the magnetic head shown in Figure 1. Complete.At this time, the board (20)
By making the slicing direction for (30) inclined with respect to the abutting surface, a magnetic head for azimuth recording can be manufactured.

Here, one magnetic core half (11) of this magnetic head
has a ferromagnetic oxide substrate (20) as a base material, and the other magnetic core half (12) has a ferromagnetic oxide substrate (30) as a base material. Further, the ferromagnetic metal m film (13) is replaced with the ferromagnetic metal thin film (23), and the non-magnetic material (14) is replaced with the non-magnetic material (2).
4), the non-magnetic material (15) corresponds to the non-magnetic material (28), respectively. In addition, non-magnetic films (17a), (17
b) b corresponds to the strips (22a) and (22b) of the nonmagnetic film (22) deposited on the substrates (2G) and (3G).

In a magnetic head manufactured by such a manufacturing process, non-uniform parts of the film structure of the ferromagnetic metal iIl film (23) are scraped off during the polishing process explained in FIG. 7, that is, during gap surface polishing. Therefore, a magnetic gap is formed on one plane, and each part of the ferromagnetic metal Titn! exhibits high magnetic permeability along the magnetic path. (23) alone, and stable high output can be obtained.

Although specific examples of the present invention have been described above, the present invention is not limited to these examples.

〔Effect of the invention〕

As is clear from the above description, in the magnetic head of the present invention, a nonmagnetic film is interposed between the ferromagnetic metal IIIM and the ferromagnetic oxide located between the winding groove and the back gap surface. Therefore, the strain caused by the difference in coefficient of thermal expansion between the ferromagnetic metal thin film and the ferromagnetic oxide is dispersed, preventing the occurrence of cranks, improving reliability, and stabilizing electromagnetic conversion characteristics. becomes.

Further, the magnetic head of the present invention has a good yield during processing and is a magnetic head that is excellent in terms of productivity.

Furthermore, since the magnetic head of the present invention uses a ferromagnetic metal thin film formed on one plane as a high magnetic flux film in the vicinity of the magnetic gap, the thin film has a uniform film structure in each part, and the magnetic head The entire film exhibits high magnetic permeability in the direction along the magnetic path, resulting in high reproduction output. Furthermore, since most of the magnetic tape sliding contact surface is composed of ferromagnetic oxide, it has excellent wear resistance and does not cause uneven wear. Since the columnar structure growth direction and magnetic anisotropy of the ferromagnetic metal thin film constituting the magnetic gap are uniform, uniform magnetic properties are ensured.

[Brief explanation of drawings]

FIG. 1 is an external perspective view showing an embodiment of a magnetic head to which the present invention is applied, and FIG. 2 is an enlarged plan view of essential parts showing the magnetic tape contacting surface of the magnetic head. 3 to 10 are schematic perspective views showing the manufacturing steps for manufacturing the magnetic head shown in FIG. 1 according to the order of the steps, and FIG. The figure shows the nonmagnetic film forming process, Figure 5 shows the nonmagnetic film etching process, Figure 6 shows the ferromagnetic metal thin film deposition process, Figure 7 shows the glass melt filling and surface grinding process, and Figure 8 shows the second process. FIG. 9 shows the winding groove and H-groove processing process, and FIG. 10 shows the substrate bonding and slicing process. FIG. 11 is an external perspective view showing a conventional magnetic head. 11.12...Magnetic core halves 11a, 12a...Ferromagnetic metal'FR film forming surface 11c
, 12c... Back gap forming surface 13 ・
...Ferromagnetic metal l111!16...Winding grooves 17a, 17b...Nonmagnetic film

Claims (1)

[Claims] A magnetic core half made of a ferromagnetic oxide and a ferromagnetic metal thin film formed on the ferromagnetic metal thin film forming surface of the magnetic core half so as to extend from the front gap to the back gap. In a magnetic head in which a magnetic gap is formed by abutting the ferromagnetic metal thin films, the ferromagnetic metal thin film forming surface and the magnetic gap forming surface are in a predetermined position when viewed from the tape contacting surface. The ferromagnetic metal thin films tilted at an angle of A magnetic head characterized by having a film interposed therein.