JPH0831203B2 - Magnetic head - Google Patents

Description

The present invention relates to a magnetic head, and more particularly to a magnetic head provided with a glass material suitable for use with an amorphous magnetic material as a magnetic film.

[Conventional technology]

Along with the increasing density of magnetic recording, magnetic heads have been developed that use an amorphous magnetic material having a high saturation magnetic flux density as a magnetic film.

A conventional magnetic head of this type is disclosed in JP-A-56-16.
As described in Japanese Patent No. 9214 or Japanese Utility Model Laid-Open No. 61-45716, the characteristics of the glass material formed on the sliding surface with the magnetic tape are not touched, and the abrasion resistance, etc. For, the bulk material such as ceramics is attached by adhesion with low melting point glass.

[Problems to be solved by the invention]

In the above-mentioned prior art, using a low-melting glass, in the one that is embedded and bonded with good wear resistance ceramics, the low-melting glass is not described in detail, and with the glass layer used for the ceramics and adhesion. The boundaries are also not detailed. Further, at the time of bonding, how the characteristics of the amorphous magnetic material as a magnetic material are deteriorated by the glass material as an adhesive, and the vitrification reaction between the glass material and the gear material or the glass material is Reacts with the amorphous magnetic material forming the track width,
The problem of causing the characteristic deterioration of the amorphous magnetic material and reducing the substantial track width has not been studied. In particular, the reduction of the track width is a serious problem in the magnetic head and has a great influence on the yield in the head manufacturing process.

The present invention has a structure in which a notch portion of a magnetic head using an amorphous magnetic material is filled with glass, the glass material reacts with the amorphous magnetic material, and the track width is not substantially changed. Sometimes it happens,
It is an object of the present invention to provide a magnetic head with reduced wear and improved wear resistance and reliability so that stable output can be obtained at all times without uneven wear when the tape is in sliding contact.

[Means for solving problems]

In order to achieve the above object, the composition of the glass material to be filled is changed, and each of them is examined for a large reaction or a small reaction with amorphous, and each is preferable in terms of mechanical properties for machining. I checked whether it was a thing.

Further, since the amorphous magnetic material is used as the magnetic film during filling and bonding of the glass material, the amorphous magnetic material is crystallized at a temperature equal to or higher than the crystallization temperature of the amorphous film, and its magnetic characteristics are deteriorated. That is, there is an upper limit to the processing temperature during filling and bonding, and when considering mass production, it is necessary to consider the margin such as the temperature distribution of the electric furnace and perform the processing at a temperature as low as possible lower than the crystallization temperature of the amorphous magnetic material. There is.

FIG. 5 is an explanatory view showing the composition of the glass material for explaining the present invention.

The composition of the glass is basically _{P b O-B 2 O 3} -SiO 2 -ZnO-Al
_{It is} composed of 6 elements of ₂ O ₃ —Bi ₂ O ₃ , and is shown as sample names A to F by changing various components.

FIG. 6 is an explanatory diagram showing the characteristics of the glass materials of sample names A to F shown in FIG.

Further, FIG. 7 is a graph showing the Vickers hardness of each glass of sample names A to F shown in FIG. 5 and the breaking strength of the glass material.

In FIGS. 5, 6, and 7, the softening point of the glass is
Despite being almost unchanged from 360 to 370 ℃, the hardness, strength, and degree of reaction with amorphous magnetic materials are remarkably different depending on the composition. Especially sample name A
For the other sample names B to F, the water resistance was remarkably improved. Here, the water resistance refers to how much the glass melts when immersed in water at 60 ° C., and is represented by a method of displaying the relative value of time when the glass of sample name A is 1. There is.
This number should be small (ie, difficult to melt).

Further, it can be seen that the sump names D, E, and F are more effective in the Vickers strength and the bending strength than the sample names A, B, and C.

In machining, if the Vickers hardness is 270 to 280 or more, chipping and chipping are significantly reduced and the yield is improved.

In addition, the sample names D, E, and F have the least amount of reaction with the amorphous magnetic material shown in Fig. 2, and when compared with the glass of the sample name A, the sample names D, E, and F are particularly small.
For example, the response is about 1/3 or less, and the amount of change in the effective track width is a value that does not pose a problem, and the effect is remarkable.

When the sample names A, B and C are compared with the sample names D, E and F, the major differences are that the composition ratio of SiO ₂ is increased from 1 to 2% to 3%, and Al ₂ O ₃ or This means that Bi ₂ O ₃ is added in a very small amount, which reduces the reaction with the amorphous magnetic material.

Regarding water resistance, addition of ZnO is shown to be effective.

[Action]

Comprehensively looking at the above, it can be seen that the water resistance, the reaction with the amorphous magnetic film, the processability, the glass strength, etc. can be favorably changed without changing the softening point of the glass. . The fact that the treatment can be performed without raising the softening point is remarkably effective in producing a head using the amorphous magnetic material film. Conversely, there are many other glasses that are preferable if the softening point can be raised. In the present invention, the softening point is 100
A high temperature around ℃, that is, a bonding treatment temperature or a heat treatment temperature of 440 to 490 ℃ is considered, and the crystallization temperature Tx of the amorphous magnetic material film is assumed to be about 520 to 550 ℃. For example, in a Co-Nb-Zr amorphous magnetic material film,
Assuming Tx of about 520 to 550 ℃, the saturation magnetic flux density Bs is 90.
A film of about 100 to 10,000 G can be obtained and can be sufficiently written on a metal powder tape having an Hc of 1400-1500 Oe.

〔Example〕

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

FIG. 1 is a front view of a magnetic tape sliding surface of a head chip showing an embodiment of a magnetic head according to the present invention, in which 1 is a film of an amorphous magnetic material (hereinafter referred to as an amorphous magnetic film) and 2 is SiO _2. An insulating film made of 3 is a protective film made of Cr, 4 is a glass material layer as a filling / adhesive material (hereinafter,
(Referred to as a glass layer), 5 is a gear material made of SiO ₂ , 6
Is a base made of ferrite, 7 is a chevron forming surface, 7'is a chevron top of the chevron forming surface, and 8 is a core half.

In the figure, the magnetic head is a pair of an amorphous magnetic film 1 deposited on a chevron-shaped chevron forming surface 7 formed on a base 6 made of ferrite, and an insulating film 2 and a protective film 3 deposited on the amorphous magnetic film 1. The core half body 8 of is formed by grinding and lapping the amorphous magnetic film on the chevron apex 7'of the chevron forming surface 7 so that the machined surfaces for the track width regulation face each other via the gear stopper 5 It is formed by butting and filling a glass material on the protective film 3 between the respective chevron forming surfaces 7 of the pair of core halves 8 to form a glass layer 4 and bonding both core halves.

At this time, SiO ₂ as the gear material 5 is vitrified by vitrification reaction with the glass layer 4 and integrated with the glass layer 4 between both core halves.

FIG. 2 is an enlarged view of a main part of the sliding surface of the magnetic tape shown in FIG. 1, and the same reference numerals as those in FIG. 1 indicate the same parts.

In the same figure, when both core halves 8 are butted against each other and the glass layer 4 is filled, as described above, the gear tape material on the processed surface (gear tape portion) for controlling the track width vitrifies and reacts with the glass material. It is homogenized as layer 4.

However, when the pair of core halves are bonded by filling with the glass material, the vitrification reaction with the glass material at the core half bonded portion of the gear tape material 5 described above is preferable from the viewpoint of adhesiveness. However, the above-mentioned vitrification reaction tends to extend not only to the core half-body bonded portion but also to the gear gap portion. As a result, the track width regulation length (indicated by T _D in FIG. 1) may become shorter.
This is remarkable when the glass of sample name A in the figure is used.

The filled glass material also reacts with the amorphous magnetic material, and the glass material enters the amorphous magnetic material,
Not only leads to deterioration of the magnetic characteristics, but also shortens the effective track width, and has a serious adverse effect on the operation as a magnetic head.

However, such a situation occurs because the glass material according to the present invention, that is, 75 <PbO <85,8 <B ₂ O ₃ <15,2 <SiO ₂ <5,2.
It can be reduced by using a glass material having a composition containing <ZnO <9,0 ≦ Al ₂ O ₃ <5,0 ≦ Bi ₂ O ₃ <3 in each weight percentage.

For example, if the glass material having the sample name D in FIG. 5 is used, the size of the reaction portion shown in FIG. 2 in the magnetic head having the structure shown in FIG. It can be reduced to one-third or less of that used, and the length in the track width direction can be reduced to 0.2 μm or less. This shortened length is practically negligible, resulting in a head manufacturing yield of 20%.
It was possible to improve above.

Moreover, the glass material of sample name D shown in FIG. 5 can be filled and bonded with the same temperature profile as sample name A, and there is no need to set special conditions.

Also, the glass head of sample name E in FIG. 5 was used to create the magnetic head with the same process and profile as the glass material of sample name D. Similar to the case where the glass material of sample name D was used. In addition, there was little reaction with the amorphous magnetic material, there was little reduction in the length in the width direction of the track due to vitrification reaction with the gear material, and a magnetic head with high accuracy and high yield was obtained.

In addition, the magnetic heads using glass materials of sample names D and E were run for a long time, and the degree of uneven wear, the change over time in output, etc. were tested. Good results were also obtained in tests in a high humidity atmosphere.

From this, as the glass material for bonding the core half of the magnetic head using the amorphous magnetic material as the magnetic film,
The glass materials with sample names C to F in FIG. 5 are suitable, and the glass materials with sample names D, E, and F are particularly suitable.

In addition, in the composition of FIG. 5, all are shown by integers, but this is only an approximate number, and the numerical value is not necessarily an integer as long as it is within the range of the weight percentage described in the examples. You should be careful.

 Next, a method for manufacturing the magnetic head of the present invention will be described.

FIG. 3 is a front view showing one of the core half blocks for manufacturing the core half, in which 1 is an amorphous magnetic film, 2 is a SiO ₂ film, 3 is a Cr film, 4 is a glass layer, 5 Is an SiO ₂ film (gap material), 6 is a ferrite (base), 7 is a chevron forming surface, and 9 is a core half block.

In the figure, first, a plurality of chevron grooves are formed on the ferrite serving as the base body 6 with a dicing saw or the like to form chevron formation surfaces 7. Using a sputtering device on the chevron-shaped surface 7, an amorphous magnetic material (for example, Co-Nb-Z) is used.
n) is deposited to a thickness of 20 to 30 μm to form the magnetic film 1. Next, the protective films 2 and 3 are formed. Here, the SiO ₂ film is 0.3 μm thick as the protective film 2 and the Cr film is 0.5 μm thick as the protective film 3.
The thickness is formed by a spattering device.

The protective films 2 and 3 have a function of suppressing a reaction between the magnetic film 1 and a glass material described later.

As the glass material to be filled on the protective film, one having the composition of sample name D in FIG. 5 is used.

As for this glass material, a plate-shaped material is placed on the chevron-forming surface, and N ₂
By holding in an atmospheric electric furnace at 470 ° C. for 20 minutes, the mountain-shaped groove portion is filled.

After the glass material is filled to form the glass layer 4, the filling surface is ground and lapped to expose the magnetic film 1 at the top of the chevron to the extent that the track width is restricted (track width forming process).

The surface of the magnetic film subjected to the track widthening process usually has a surface roughness of 0.05S (that is, the peaks and peaks of the unevenness on the surface are
(0.05 μm) mirror surface.

Next, a gear tape material (SiO ₂ ) 5 to be a head gear tape is adhered and formed by sputtering to obtain one core half block 9 .

FIG. 4 is a front view showing two core half blocks 9 shown in FIG. 3 (that is, a pair) and their track width regulating surfaces butted against each other. Corresponding to, 8 is the part that becomes the core half of the head chip, and 10 is the cut white.

As shown in the same figure, a pair of core half blocks 9 and 9 are butted against their track width restriction surfaces, and the same as above.
By holding at 473 ° C for 20 minutes in an N ₂ atmosphere electric furnace,
Obtain an integrated head block that is glued together.

A plurality of head chips are obtained by cutting the head block at a cutting white portion with a dicing saw or a wire saw.

One of the head chips thus obtained is the one shown in FIG.

The magnetic head of the present invention can be manufactured as described above.

[Effects of the Invention] As described above, according to the present invention, it is possible to increase the amorphous magnetic property without increasing the processing temperature for filling and bonding the glass layer, that is, by setting the softening point temperature of the glass material to around 100 ° C. By selecting a glass material with an optimal composition that can be treated at a temperature below the crystallization temperature of the body, it is possible to use the most suitable filled glass for the amorphous magnetic film, improve the processability, have less reaction with the amorphous magnetic film, and It is possible to provide a magnetic head having high water resistance and wear resistance and high reliability.

[Brief description of drawings]

FIG. 1 is a front view of a magnetic tape sliding surface of a head chip showing an embodiment of a magnetic head according to the present invention, and FIG. 2 is an enlarged view of an essential part of the magnetic tape sliding surface shown in FIG. 1, FIG. Is a front view of the core half block for making the core half, No. 4
FIG. 5 is a front view showing a state where two core half blocks are abutted, FIG. 5 is an explanatory view showing the composition of the glass material, FIG. 6 is an explanatory view showing the characteristics of the glass material shown in FIG. FIG. 7 is a graph showing the hardness of the glass material and the bending strength of the glass material shown in FIG. 1 ... Amorphous magnetic film, 2 ... SiO ₂ film, 3 ... Cr
Film, 4 ... Glass layer, 5 ... SiO ₂ film, 6 ... Substrate, 7 ...
… Yamagata formation surface, 7 ′ …… Yamagata top, 8 …… Core half, 9 …
… Core half block, 10 …… cut white.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nobuo Manabe 1410 Inada, Katsuta City, Ibaraki Prefecture Inside the Tokai Works, Hitachi, Ltd. (56) References JP 57-20910 (JP, A) JP 62 -46409 (JP, A) JP 61-250810 (JP, A) JP 61-142520 (JP, A)

Claims (1)

[Claims] 1. A magnetic film made of an amorphous material is formed on a chevron-shaped surface of a substrate, and a flat gap surface is formed on the top to form a core half body.
In the magnetic head, which is bonded to the gap surface through a gap made of SiO ₂ , and between the pair of core halves other than the gap portion is filled with a glass material, the amorphous material is It contains Co in at least a part of its composition, and has a crystallization temperature of 520 to 550 ° C., and the glass material contains PbO, B ₂ O ₃ , SiO ₂ and ZnO containing Al ₂ O ₃ or Bi ₂ O.
₃ is is contained, these compositions are in weight percent, 75 <PbO <85 8 < B 2 O 3 <15 2 <SiO 2 <5 2 <ZnO <9 0 ≦ Al 2 O 3 <5 0 ≦ Bi A magnetic head characterized in that ₂ O ₃ <3.