JPH07220215A - Magnetic head - Google Patents

Abstract

(57) [Summary] [Purpose] Achieves high recording / reproducing characteristics over a wide range with excellent high-frequency characteristics, and also reduces uneven wear on the sliding surface of the magnetic recording medium to achieve high wear resistance. [Structure] A front side core portion 1 and a back side core portion 2 joined and integrated with a lower portion of the front side core portion 1.
And the reinforcing members 3 and 4 respectively joined to both side surfaces of the front side core section 1 and the back side core section 2 in the magnetic recording medium sliding direction, which are integrated with each other, in the front side core section 1 The wear resistant reinforcing members 7 and 8 made of a non-magnetic material having high wear resistance are joined to both side edges of the magnetic gap forming surface 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to, for example, a video tape recorder (VTR) and a digital data recorder (R-DA).
The present invention relates to a magnetic head useful for mounting on a magnetic recording / reproducing apparatus capable of high density recording such as T).

[0002]

2. Description of the Related Art In a magnetic recording / reproducing apparatus such as a VTR, the recording signal has been made higher in density and frequency, and in response to the higher density recording, magnetic powder is used as a magnetic recording medium and Fe. , So-called metal tapes using powders of ferromagnetic metals such as Co and Ni, and so-called vapor deposition tapes in which a ferromagnetic metal material is deposited on a base film by vapor deposition have been used. Since this type of magnetic recording medium has a high residual magnetic flux density and a high coercive force, a head material of a magnetic head used for recording / reproducing is also required to have a high saturation magnetic flux density and a high magnetic permeability.

On the other hand, along with the above-mentioned high-density recording, the recording track width to be recorded on the magnetic recording medium is being narrowed, and in response to this, the magnetic head having a very narrow track width is required. Has been done.

Therefore, conventionally, a so-called laminate type magnetic head has been proposed in which a ferromagnetic metal film serving as a magnetic core is adhered on a non-magnetic substrate such as ceramics and used as a track portion. In the magnetic head, the track can be easily narrowed by controlling the thickness of the ferromagnetic metal film, and a pseudo gap does not structurally occur.
Further, there are various advantages such as the absence of a gap in the back portion and the simple manufacturing process.

As an example of a conventional laminated type magnetic head, as shown in FIG. 17, a pair of magnetic core halves 10 is used.
There is a structure in which the magnetic gap g2 is formed by integrally joining 1 and 102 at each abutting surface. The magnetic core half body 101 is configured by joining and fixing the non-magnetic substrates 103 and 104 via a ferromagnetic metal film 105 made of sendust or the like, and forming a winding window 106 for winding. Similarly, the magnetic core half body 102 also includes the non-magnetic substrate 1.
07 and 108 are bonded and fixed via the ferromagnetic metal film 105.

[0006]

By the way, in order to reduce wear due to tape sliding in such a laminated magnetic head, a material having high wear resistance is selected as the non-magnetic substrate sandwiching the ferromagnetic metal film. There is a need to. In addition, uneven wear occurs due to the difference in wear between the ferromagnetic metal film and the non-magnetic substrate that sandwiches the ferromagnetic metal film. Therefore, it is necessary to control wear resistance. In particular, when the recording frequency is widened to improve the recording density and recording / reproduction is performed by high-speed sliding, it is necessary to further improve the wear resistance, and at the same time, a higher saturation magnetic flux density and a higher magnetic permeability are required. It is necessary to improve it.

However, it is difficult to avoid uneven wear with only two ferromagnetic metal films having different wear resistance and a non-magnetic substrate as in the conventional magnetic head, and various characteristics of the head such as high frequency characteristics are difficult to avoid. There was a problem of not being satisfied.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to realize a high recording / reproducing characteristic over a wide range with excellent high frequency characteristics, and moreover, a deviation of a sliding surface of a magnetic recording medium. An object of the present invention is to provide a magnetic head capable of reducing wear and achieving high wear resistance.

[0009]

In order to achieve the above-mentioned object, the present invention has a structure in which a front side core portion forming a magnetic gap has a ferromagnetic metal film sandwiched between non-magnetic substrates and a back side core portion. The core part is integrally formed of magnetic ferrite, the front side core part and the back side core part are joined together, and both side surfaces in the sliding direction of the magnetic recording medium are reinforced by reinforcing members, and the magnetic force of the front side core part is increased. A non-magnetic material having higher wear resistance than the non-magnetic substrate is arranged on the sliding surface of the recording medium.

[0010]

In the magnetic head according to the present invention, the front core portion has a structure in which a ferromagnetic metal film is sandwiched between non-magnetic substrates, and the back core portion is integrally formed of magnetic ferrite. The magnetic path cross-sectional area is significantly increased as compared with the case where only the ferromagnetic metal film portion is the magnetic path. Therefore, as the magnetic path cross-sectional area increases, the magnetic resistance decreases and the reproduction characteristic improves. further,
Since the non-magnetic material having higher wear resistance than the non-magnetic substrate is arranged on the magnetic recording medium sliding surface of the front side core portion,
The sliding surface of the magnetic recording medium of the front side core portion, which is likely to cause uneven wear, is reinforced, and the life of the magnetic head is greatly extended.

[0011]

EXAMPLES Examples of the magnetic head according to the present invention will be described.
A description will be given with reference to the drawings. As shown in FIG. 1, the magnetic head according to the above-described embodiment includes a front side core portion 1 and a back side core portion 2 which is joined and integrated to a lower portion of the front side core portion 1, and is integrated with each other. The front core portion 1 and the back core portion 2 are composed of reinforcing members 3 and 4 respectively joined to both side surfaces of the magnetic recording medium in the sliding direction.

The front side core portion 1 has magnetic core halves 11 and 12 on which a ferromagnetic metal film 5 such as sendust is formed.
Are joined and fixed at each abutting surface to form a magnetic core 6, and a magnetic gap g1 for recording and reproduction is formed. The material of the magnetic core 6 is from both side edges of the magnetic gap forming surface of the magnetic core 6. The wear resistant reinforcing members 7 and 8 made of a non-magnetic material having higher wear resistance than the non-magnetic material are joined and integrated to form a sliding surface 13 of the magnetic recording medium.

The back side core portion 2 is made of magnetic ferrite having excellent high frequency characteristics, and is bonded and fixed to the lower portion of the front side core portion 1 to form a winding window 14. That is, in the above-mentioned embodiment, the back side core portion 2 has a structure having no magnetic gap.

Now, a method of manufacturing the magnetic head according to the above embodiment will be described. To manufacture such a magnetic head, first, as shown in FIG. 2, a ferromagnetic metal film 5 serving as a magnetic core is formed on one surface of a strip substrate 23 made of a non-magnetic material by a vacuum thin film forming method such as sputtering. As the ferromagnetic metal film, Fe-Al-Si, Fe-Ni-Al-S
i, Fe-Ga-Si, Fe-Al-Ge, etc., and 8 atomic% or less of Co, Ti, Cr, Nb, Mo, T
A crystalline material in which one or several kinds of a, Ru, Au, Pd, N, C, O, etc. are added, or Co is mainly Zr, Ta, T
i, Hf, Mo, Nb, Au, Pd, Ru, etc. Amorphous material formed by adding one or several kinds, Co, F
e, mainly Ni, Zr, Ta, Ti, Hf, Mo,
Nb, Si, Al, B, Ga, Ge, Cu, Sn, R
A microcrystalline material or the like formed by adding one or several kinds of u, B and the like and one or several kinds of N, C, O and the like is selected.

Next, as shown in FIG. 3, a plurality of strip substrates 23 each having a ferromagnetic metal film formed thereon are joined and integrated to form a magnetic core substrate 24. The magnetic core substrate 24 is cut along the lines AA ', BB', and CC 'as shown in FIG. 4, for example, and a pair of cores having substantially symmetrical shapes as shown in FIG. The half blocks 25 and 26 are produced.

Then, as shown in FIG. 6, a substrate 41 is bonded to the core half blocks 25 and 26. Then, as shown in FIGS. 7 and 8, the block integrally joined is cut into a rectangular shape indicated by a broken line in the drawings to produce upper magnetic core half blocks 27 and 28. After that, as shown in FIG. 9, a winding groove 29 extending along the longitudinal direction is formed in the upper magnetic core half block 28, and one side of the upper magnetic core half block 27 and the groove of the upper magnetic core half block 28 are formed. Smooth the surface to be formed. Then, a gap spacer 30 is formed on the polished surface by a vacuum thin film forming method such as sputtering, and these upper magnetic core half blocks 27 and 28 are butted so that the respective ferromagnetic metal films 5 face each other.

Thereafter, as shown in FIG. 10, these upper magnetic core half blocks 25 and 26 are joined and integrated. As a result, each upper magnetic core half block 27, 2
Between the abutting surfaces of the ferromagnetic metal films 5 formed on the magnetic gaps 8 and the magnetic gap g that operates as a read / write gap.
1 is formed.

Then, as shown in FIG. 10, the upper magnetic core half blocks 25 and 26, which are joined and integrated with each other, are magnetized to D
The magnetic core block front part 31 shown in FIG. 11 is produced by cutting along the line −D ′, and the cut surface 32 is smooth-polished.

Next, as shown in FIG. 12, a winding groove 34 is formed in the magnetic ferrite substrate 33 and cut along the line EE 'to form the magnetic core block back portion 35 shown in FIG. Create. Further, the upper surface portion 36 and the cut surface of the magnetic core block back portion 35 are polished.

Thereafter, as shown in FIG. 14, the magnetic core block front portion 31 and the magnetic core block back portion 35 are formed.
And the cut surface 32 and the cut surface 36 are integrally joined to form the winding window 1
4 is formed, and the magnetic core block 39 is sandwiched between the substrates 38 to produce a magnetic core block 39.

Then, as shown in FIG. 15, the magnetic recording medium sliding surface 13 having a predetermined curvature is formed by lapping to a predetermined gap depth, and the line F-F'G-G 'is formed. By cutting along the line, the magnetic head core shown in FIG. 1 is completed.

For joining the respective members, heretofore known joining methods can be used, and examples thereof include low temperature thermal diffusion joining by heat diffusion between the noble metal layers and joining method by glass fusion or the like. . Although the ferromagnetic metal film 2 formed on the strip substrate 3 is a single layer film in the above-mentioned embodiments, oxides or nitrides of Si, O ₂ , Al ₂ O ₃ , Si ₃ N _4, etc. are used. By forming a thin film of ferromagnetic metal film 5 having a small thickness through the electrically insulating film as described above, a eddy current loss in a high frequency band can be significantly reduced. In addition, a non-magnetic substrate 41 joined to the head sliding portion,
The substrates 38 sandwiched from the side surface of the head may be the same.

Here, one experimental example will be shown. In this experimental example, the magnetic head according to the above-described embodiment and a conventional magnetic head for comparison with the magnetic head are used as test objects to examine the frequency dependence of these inductances. In this experimental example, the frequency unit is MHz and the inductance is a relative value. A network / spectrum analyzer (HP419) manufactured by Hewlett-Packard Co. is used to measure the inductance.
5A) was used.

As a result of the above-mentioned experimental example, as shown in FIG. 16, the magnetic head according to the above-mentioned embodiment has a slightly inferior inductance at a low frequency as compared with the conventional type head, but it is considerably extended at a high frequency. It can be seen that the recording density is improved and the frequency band is widened.

In the magnetic head according to the above embodiment,
Since the front core 1 has a structure in which the ferromagnetic metal film 5 is sandwiched between non-magnetic substrates, and the back core 2 is integrally formed of magnetic ferrite, only the ferromagnetic metal film 5 is magnetic. The magnetic path cross-sectional area is significantly increased as compared with the case of a path. Therefore, as the magnetic path cross-sectional area increases, the magnetic resistance decreases and the reproduction characteristic improves. Further, since the magnetic recording medium sliding surface 13 of the front side core portion 1 is provided with the wear resistant reinforcing members 7 and 8 made of a non-magnetic material having higher wear resistance than the non-magnetic substrate,
The magnetic recording medium sliding surface 13 of the front side core portion 1 in which uneven wear is likely to occur is reinforced, and the life of the magnetic head is greatly extended.

Therefore, excellent reproduction characteristics can be obtained even on the high frequency side, and high recording / reproduction characteristics can be realized over a wide range. Moreover, it is possible to reduce uneven wear of the sliding surface 13 of the magnetic recording medium and achieve high wear resistance.

[0027]

According to the magnetic head of the present invention, the front side core portion forming the magnetic gap has a structure in which a ferromagnetic metal film is sandwiched between nonmagnetic substrates, and the back side core portion is integrated by magnetic ferrite. The front side core portion and the back side core portion are joined together, both side surfaces in the magnetic recording medium sliding direction are reinforced by reinforcing members, and the magnetic recording medium sliding surface of the front side core portion is Since a non-magnetic material, which has higher wear resistance than that of a non-magnetic substrate, is arranged, high-frequency characteristics are excellent and high recording / reproducing characteristics are realized over a wide range, and uneven wear on the sliding surface of the magnetic recording medium is reduced. High wear resistance can be achieved.

[0028]

[Brief description of drawings]

FIG. 1 is a perspective view schematically showing a magnetic head according to an embodiment.

FIG. 2 is a perspective view showing a process of forming a ferromagnetic metal film on a strip substrate.

FIG. 3 is a perspective view showing a process of manufacturing a magnetic core substrate by joining and integrating a plurality of film-shaped strip substrates.

FIG. 4 is a perspective view showing a step of cutting a core half block from a magnetic core substrate.

FIG. 5 is a perspective view showing a pair of manufactured core half blocks.

FIG. 6 is a perspective view showing a step of joining and integrating a substrate with a core half block.

FIG. 7 is a perspective view showing a state of cutting out a pair of upper magnetic core half blocks.

FIG. 8 is a perspective view showing a state in which a pair of upper magnetic core half blocks are cut out.

FIG. 9 is a perspective view showing a state in which winding groove processing is applied to the upper magnetic core block.

FIG. 10 is a perspective view showing a process of cutting out an upper magnetic core block and smoothing it to produce a magnetic core block front portion.

FIG. 11 is a perspective view showing a manufactured magnetic core block front portion.

FIG. 12 is a perspective view showing a process of forming a magnetic core block back portion by subjecting a magnetic ferrite substrate on the back side to winding groove processing.

FIG. 13 is a perspective view showing a manufactured magnetic core block back portion.

FIG. 14 is a perspective view showing a step of producing a magnetic core block by joining and integrating a magnetic core block front portion and a magnetic core block back portion and further sandwiching both sides with a substrate.

FIG. 15 is a perspective view showing a step of cutting out the magnetic head core after lapping the manufactured magnetic core block.

FIG. 16 is a characteristic diagram showing the results of comparison of the inductances of the magnetic head according to the present embodiment and the conventional laminating head.

FIG. 17 is a perspective view showing the structure of a conventional laminated magnetic head.

[Explanation of symbols]

 1 Front-side core part 2 Back-side core part 3,4 Reinforcing member 5 Ferromagnetic metal film 6 Magnetic core 7,8 Anti-wear reinforcing member 11,12 Magnetic core half body 13 Magnetic recording medium sliding surface

Claims (1)

[Claims] 1. A front side core portion forming a magnetic gap has a structure in which a ferromagnetic metal film is sandwiched between non-magnetic substrates, and a back side core portion is integrally formed of magnetic ferrite. The core part and the back side core part are joined, both side surfaces in the sliding direction of the magnetic recording medium are reinforced by reinforcing members, and the magnetic recording medium sliding surface of the front side core part is more wear resistant than the non-magnetic substrate. A magnetic head characterized in that a highly magnetic non-magnetic material is arranged.