JPH10228605A - Magnetic head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a spacing loss and yet to improve gap positioning accuracy when a drum is mounted with the magnetic head of a lamination type having a magnetic core composed of a magnetic film consisting of a lamination type amorphous material. SOLUTION: The magnetic head is composed of one pair of lamination type amorphous magnetic cores 1 and 1' held between nonmagnetic guard materials 2 and joined together via a gap material GAP. This gap material GAP is formed with buffer layers 10a and 10b and Au layers 11a and 11b, which are layered in turn on the jointed surfaces of one pair of magnetic cores 1 and 1' respectively, and are integrally joined up by thermodiffusion of the Au layers 11a and 11b with each other. In this case, the lower limit of the thickness of the Au layer 11a(11b) is 10nm, and the upper limit of the thickness of the Au layer 11a(11b) is aimed and decided from the gap length to be <=1/3 of the total thickness of the buffer layer 10a(10b) and the Au layer 11a (11b).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a magnetic recording / reproducing apparatus such as a video recorder, a magnetic head mounted on a floppy disk drive, a hard disk drive and the like. More specifically, the present invention relates to a magnetic head in which a magnetic core is composed of only a magnetic film, a spacing loss is suppressed, and a gap positioning accuracy when mounting a drum is improved.

[0002]

2. Description of the Related Art In the field of magnetic recording, attempts have been made to shorten the recording wavelength and increase the frequency range in order to increase the density of recording signals.

In order to respond to such attempts, in recent years,
As a magnetic head, a laminated magnetic head having a plurality of magnetic layers each having a magnetic core laminated via an insulating film such as a SiO ₂ thin film has been developed. In particular, recently, a laminated magnetic head using a Co-based amorphous metal as a magnetic layer has been put into practical use. Such a laminated magnetic head has been developed as a reproducing head for a commercial digital VTR or a high-density data streamer.
Excellent reproduction characteristics in short wavelength and high frequency range. Further, since the magnetic path is formed only of the laminated magnetic film, the thickness of the magnetic core becomes the track width as it is, so that there is an advantage that it is not necessary to form the track width regulating groove.

When a magnetic head is manufactured by gap-bonding a pair of magnetic cores made of such a magnetic amorphous metal, a glass frit is supplied to the gap portion and heated to 500 ° C. or higher as in the conventional case. Then, when the glass is welded, there is a problem that the amorphous metal is recrystallized and the magnetic permeability decreases.

Therefore, when such a laminated amorphous magnetic core is gap-joined, it is not heated to such a temperature, but at a temperature (below 450 ° C. or lower) at which recrystallization of the amorphous metal does not occur. Low temperature A that can be joined
It has been proposed to perform gap joining by a u-junction method (Japanese Patent Application Laid-Open No. Hei. 3-16006). Here, the low-temperature Au bonding method means heating Au thin films (200 ° C. to 400 ° C.).
Pressure) while Au is bonded to the metal,
This is a method utilizing a phenomenon in which thin films of u are integrally joined.

When the low-temperature Au bonding method is applied to gap bonding of a magnetic core, the adhesion between the amorphous metal and Au is not sufficient, so that chromium having good adhesion to both of them is provided between them. It has been proposed to form a buffer layer of titanium or titanium (Japanese Patent Application Laid-Open No. Hei. 3-16006). In this case, the total layer thickness of Au and the buffer layer is determined from the target gap length, and the Au layer thickness of the magnetic core on one side is a thickness (usually 60 nm) that does not cause any problem in the bonding strength. Is set to The gap length is twice the total thickness of the buffer layer and the Au layer.

[0007]

However, low temperature A
When the magnetic tape is slid and moved with respect to such a laminated amorphous magnetic head integrally joined by the u-joining method, foreign matters such as magnetic powders and binders cause Au joint gap (buffer) on the head sliding surface. (Au layer and Au layer) is easily adhered to the highly adhesive Au layer, and as a result, a gap is formed between the surface of the magnetic head and the magnetic tape. There has been a problem of a large reduction (spacing loss).

An amorphous metal (magnetic layer) and Au
There is a problem that it is very difficult to distinguish between the bonding gap and the bonding gap. Moreover, brown A occupying the Au junction gap
u is relatively large, and the polishing powder of the wrapping tape for surface facing is easily attached to Au.
There is a problem that the u-junction gap becomes almost the same color as the non-magnetic guard material, and it is very difficult to distinguish between them. For this reason, there is a concern that the accuracy of determining the gap position when the magnetic head is mounted on the drum may be reduced, and eventually, the reproduction output may be reduced due to R center deviation or the like.

An object of the present invention is to solve the above-mentioned problems of the prior art. In a stacked magnetic head in which a magnetic core is constituted only by a magnetic film made of a stacked amorphous metal, the present invention relates to a magnetic head. Reduce pacing loss,
Moreover, it is an object of the present invention to provide a magnetic head capable of improving the accuracy of positioning a gap when a drum is mounted.

[0010]

SUMMARY OF THE INVENTION The present inventor has set forth that the thickness of Au in a magnetic head having a magnetic core made of a laminated amorphous metal can be reduced to a predetermined range when performing low-temperature Au bonding. It has been found that the object can be achieved, and the present invention has been completed.

That is, the present invention relates to a magnetic head in which a pair of laminated amorphous magnetic cores sandwiched by a non-magnetic guard material are joined via a gap material, wherein the gap material comprises a pair of respective magnetic cores. In a magnetic head joined and integrated by thermal diffusion between the buffer layer and the Au layer of the Au layer sequentially laminated on the joint surface of (1), the lower limit of the thickness of the Au layer is 10 nm, and the upper limit of the thickness of the Au layer is Provided is a magnetic head characterized in that the thickness is not more than 1/3 of the total thickness of a buffer layer and an Au layer determined from a target gap length.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1A is an external view of one embodiment of the magnetic head of the present invention, FIG. 1B is a partially enlarged view of a gap portion thereof, and FIG. 1C is a partially enlarged view thereof. FIG.

As shown in FIG. 1A, the magnetic head of the present invention has a structure in which core halves 3 and 4 in which magnetic cores 1 and 1 'are sandwiched between non-magnetic guard members 2 are abutted. And
A winding groove 5 is formed in each core half.

The gap 6 between the core halves 3 and 4
As shown in FIG. 1B, a magnetic core 1 and 1 ′ each having a structure in which a plurality of magnetic amorphous metal thin films 1 a are stacked via an SiO ₂ insulating film 1 b are sandwiched by non-magnetic guard members 2. And the magnetic cores 1 and 1 '
Between them, an Au junction gap (GAP) is formed.

In this Au junction gap (GAP), buffer layers 10a and 10b are formed on the opposing magnetic cores 1 and 1 ', respectively, as shown in FIG. Au layer 11 by diffusion
An integrated Au layer 12 in which a and 11b are integrated is formed. Here, a dotted line X at the center of the integrated Au layer 12
Indicates a position corresponding to the abutting surface of the core halves 3 and 4. Here, as the buffer layers 10a and 10b, it is necessary to use a metal material having good adhesiveness to both the amorphous metal and Au.
i is preferred. In particular, Cr is preferable in that the reproduction output can be more favorably maintained.

In the present invention, as shown in FIG. 1C, the thickness (t ₁ ) of the Au junction gap (GAP) corresponds to the target gap length, and the buffer formed on the magnetic core 1 or 1 ′. Layer (10a, 10b) Thickness (t _bu ) and Au layer
(11a, 11b) It is equivalent to twice the sum of the thickness (t _Au ).

In the present invention, the Au layer (11a, 11a)
The lower limit of the thickness of b) is 10 nm, and the Au layer (11a, 1
The upper limit of the thickness of 1b) is defined as the thickness (t _bu ) of the buffer layer (10a, 10b) determined from the target gap length and Au.
The total thickness of the layers (11a, 11b) (t _Au ) is set to 1/3 or less, preferably 1/5 or less.

The reason for setting the lower limit of the thickness of the Au layers (11a, 11b) to 10 nm is that if the thickness is less than 10 nm, the low-temperature Au
This is because the joining strength at the time of joining becomes insufficient.

Further, the upper limit of the thickness of the Au layer (11a, 11b) is set to a value determined by the target gap length.
10a, 10b) and the Au layer (11a, _1b ).
The reason why the thickness of the Au layer (11a, 11b) exceeds 1/3 or less of the total thickness is 1/3) or less of the total thickness with the thickness (t _Au ) of 1b).
In this case, the reproduction output deteriorates greatly, falls below the output standard, and high-quality image cannot be maintained.

In the present invention, the Au layer (11a, 11a
By limiting the lower limit and the upper limit of the thickness b) as described above, the following two points can be considered as reasons why the reproduction output deterioration amount can be largely suppressed.

(1) Since Au is a very soft metal material, the buffer layer is relatively harder than Au. Therefore, protrusions of the buffer layer are formed on the surface of the Au junction gap (GAP). For example, when the buffer layer of the Au junction gap (GAP) is formed of Cr, when 45 nm thick Cr and 60 nm thick Au are formed on one magnetic core, the Au junction gap after the Au junction is 6 in total. When a protrusion of about 7 nm is formed, and a Cr of 20 nm and Au of 60 nm are formed on one magnetic core, a protrusion of about 3 nm in total is formed. As a result, the contact pressure between the magnetic head and the magnetic tape is reduced, the amount of foreign matter attached to the surface of the magnetic head can be reduced, and the spacing loss is suppressed.

The order of the gap at which the spacing loss occurs is determined by the protrusion (number n) of the Au junction gap.
m) is on the order of several times to 10 times or more, so Au
There is no spacing loss at the level of the protrusion formed in the junction gap.

(2) The thickness of Au, to which foreign matter is easily attached, can be suppressed to a lower level than in the past, and as a result, the amount of foreign matter attached to the surface of the magnetic head can be reduced, and spacing loss is suppressed. You.

Since the thickness of Au is suppressed to a lower level than in the prior art, the thickness of the buffer layer such as Cr having metallic luster becomes relatively large, so that it is easy to distinguish the magnetic amorphous layer or the non-magnetic guard material. Become. Therefore, it is possible to improve the gap positioning accuracy when the magnetic head is mounted on the drum.

[0026]

【Example】

Examples 1-2 and Comparative Examples 1-2 In a magnetic head as shown in FIG. 1, when the gap length is 0.16 μm, the total thickness of Cr (buffer layer) and Au of the core half is 80 nm, Au thickness is 1
0 nm (Example 1), 20 nm (Example 2), 60 nm
(Comparative Example 1) A magnetic head having a thickness of 70 nm (Comparative Example 2) was integrally joined by a low-temperature Au joining method to produce a magnetic head.

The obtained magnetic head is used as a commercial digital VT.
Attached to R, commercial VTR tape at 40 ° C, 20% RH
The vehicle ran for 48 hours under the environment. FIG. 2 shows a recording wavelength of 0.49.
The reproduction output deterioration amount at μm (frequency 47 MHz) is shown.

As can be seen from FIG. 2, the magnetic heads of Examples 1 and 2 of the present invention which fall within the thickness range of Au have a small reproduction output deterioration, while the thickness of Au exceeds the range. It can be seen that the reproduction output deterioration amount (relative value) of the magnetic heads of Comparative Examples 1 and 2 exceeds -2.

In the case of the magnetic heads according to the first and second embodiments, the gap position is determined when the head is mounted on the drum.
It was much easier than in Comparative Examples 1 and 2.

[0030]

According to the present invention, in a laminated magnetic head in which a magnetic core is composed only of a laminated amorphous magnetic film, spacing loss is suppressed, and gap positioning accuracy at the time of drum mounting is achieved. Can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view (FIG. 1A) of one embodiment of a magnetic head of the present invention, and an enlarged view of a gap portion (FIGS. 1B and 1C).

FIG. 2 is a diagram illustrating a relationship between a reproduction output deterioration amount of a magnetic head and an Au thickness obtained in an example and a comparative example.

[Explanation of symbols]

1 magnetic core, 2 non-magnetic guard material, 3 core half, 4 core half

Claims (2)

[Claims] 1. A magnetic head comprising a pair of laminated amorphous magnetic cores sandwiched by a non-magnetic guard material and joined via a gap material, wherein the gap material is provided on a joint surface of each of the pair of magnetic cores. In the magnetic head joined and integrated by thermal diffusion between the buffer layer and the Au layer of the sequentially laminated Au layer, the lower limit of the thickness of the Au layer is 10 nm, and the upper limit of the thickness of the Au layer is determined from the target gap length. A magnetic head characterized in that the thickness is not more than 1/3 of the total thickness of the determined buffer layer and Au layer. 2. The magnetic head according to claim 1, wherein the buffer layer is a Cr layer.