JPS61160809A - Production of magnetic head - Google Patents

Abstract

PURPOSE:To obtain a magnetic head having an excellent magnetic characteristic and high-frequency characteristic by adhering a thin sheet of an amorphous magnetic metal by an epoxy resin layer then polishing the laminate. CONSTITUTION:90.3% Fe, 8.1% P and 1.6% C by weight are mixed and the mixture is pressurized and vacuum sealed. The mixture is then heated at a temp. gradient of 30-100 deg.C/hr and sintering reaction is once induced therein at 500-600 deg.C/24hr. The mixture is further sintered for 1-100hr at 600-900 deg.C to obtain a sintered body. The sintered body is melted by heating and is cooled by a centrifugal quick cooling method at 10<6>-10<9> deg.C/sec cooling rate by which an amorphous magnetic metallic sheet having 100mum sheet thickness is obtd. The metallic sheet and the thermosetting epoxy resin (1mum film thickness) are adhered and laminated for 30min-4hr at 140 deg.C curing temp. and the laminate is ground to a prescribed shape by grindstone polishing to manufacture the magnetic core. The magnetic core having the excellent mechanical strength, wear resistance, magnetic characteristic and high-frequency characteristic is obtd. by such method for manufacture.

Description

BACKGROUND OF THE INVENTION Technical Field The present invention relates to a method for manufacturing a magnetic recording/reproducing head, and the present invention relates to a method for manufacturing a magnetic recording/reproducing head, which has excellent adhesive strength, wear resistance, magnetic properties, and high frequency characteristics. The present invention relates to a manufacturing method.

Prior art and its problems Magnetic heads for magnetic recording and reproduction in tape recorders, V, T, R1 electronic computers, etc. are required not only to have excellent magnetic and electrical properties but also to have excellent wear resistance. be done.

However, although magnetic heads made of various materials are currently in use, each of them has advantages and disadvantages, and it is desired to develop a magnetic head that satisfies the above-mentioned requirements in a well-balanced manner.

Magnetic heads whose magnetic cores are made of alloy magnetic materials, such as permalloy, have excellent magnetic properties, but have the disadvantage of poor wear resistance and a shorter lifespan than, for example, magnetic heads made of single-crystal ferrite. are doing.

On the other hand, magnetic heads using single-crystal ferrite have excellent wear resistance, but are inferior in magnetic properties, and require precision cutting, surface polishing, etc. because plastic processing such as hammering cannot be performed when creating the magnetic head. The number of steps involved is large, which is a cause of price increases.

In addition, in any of the above magnetic heads, in order to improve wear resistance, the material must be selected in manufacturing to ensure durability by using the optimum crystal orientation that has excellent wear resistance. It also had the disadvantage of being limited.

(2) Purpose of the Invention An object of the present invention is to provide a method for manufacturing a magnetic head having a magnetic circuit made of an amorphous magnetic metal and having excellent mechanical strength, wear resistance, magnetic properties, and high frequency properties.

■Disclosure of invention Such objects are achieved by the invention described below.

That is, the present invention is characterized in that, when manufacturing a magnetic head having a magnetic circuit made of amorphous magnetic metal, a thin plate of amorphous magnetic metal is bonded with an epoxy resin layer and then polished. This is a method of manufacturing a magnetic head.

■Specific structure of the invention The specific configuration of the present invention will be explained in detail below.

Amorphous metals (also called glass metals or amorphous alloys) are produced by rapidly cooling a metal (alloy) in a molten state with a composition near eutectic, before crystallization. It is obtained by solidifying into a glass-like solid, but among the above amorphous metals, amorphous metals (
When the chemical composition of an amorphous magnetic metal (amorphous magnetic metal) is expressed as aYb, M is Fe, Ni, or C.

using at least one of P, B, C, and Si as Y, a=60 to 9Sat%, b=s to 40
When used within the at% range, the magnetic properties as a magnetic head were almost satisfied.

That is, specific resistance can be improved and eddy current loss can be reduced, and as a result, high frequency characteristics can be improved.

In addition to this, magnetic amorphous metals containing other metal elements such as N1-Pd-P and N1-Pt-P (although it is also possible to replace part or all of phosphorus with boron) are also available. Similar results were obtained when a magnetic circuit was constructed using the same.

The magnetic head of the present invention has excellent wear resistance when 50% or more of the metal constituting the magnetic core is amorphous metal, has a coercive force H of 0.20e or less, and a maximum magnetic flux density. B
m has a characteristic of about 8,700 Gauss, so when the thin plates are laminated with epoxy thermosetting resin or other members are bonded to form a magnetic core for a magnetic head, processing is required. There is little deterioration in magnetic properties due to pressure lamination, and alignment of the abutting surfaces of the front gap is easy, allowing leakage magnetic fields to converge well, while eddy current loss can also be reduced, improving frequency characteristics. Yes, 100
It can be used for recording media of 00e or higher, and is optimal as a magnetic head for high-density recording and reproduction.

Further, in order to construct a magnetic head, thin plates may be punched into a predetermined shape, and then the sheets may be adhesively laminated, and then the surfaces may be polished. Alternatively, after laminating thin plates with adhesive,
It may be ground into a predetermined shape and the surface polished, and in either case, manufacturing can be carried out at a high yield and at low cost.

■Specific effects of the invention: As a result of using an epoxy resin, the magnetic head of the invention has high adhesive strength with a thin plate of amorphous magnetic metal;
This is because peeling does not occur during shape grinding or surface polishing after lamination. Note that when laminating resins other than epoxy resin, the adhesive strength is low and the laminated body may peel off due to grinding or polishing.

■Specific embodiments of the invention The details will be explained below using examples.

Example 1 Weight ratio of iron 90.3, red phosphorus 8.1, carbon 1.6 (80
at%Fe, 13at%P, 7aL%C) and pressed at 3.5g/mrn2. This composition ratio is close to eutectic, the melting temperature is low, and the rapid cooling effect is significant. This is vacuum-sealed and a sintering reaction is once caused at 30 to 600° C./24 hours.

Further, sintering is performed at a temperature range of 600 to 900° C. for 1 to 100 hours to obtain a sintered body.

Such a sintered body was melted by heating and cooled at a cooling rate of 10 6 -b to obtain an amorphous magnetic metal plate. This metal plate is
75% is amorphous metal, and the plate thickness is approximately 100μ
I finished it with m.

Next, this amorphous metal plate and thermosetting epoxy resin (
(film thickness: 1 μm) were adhesively laminated at a curing temperature of 140° C. for 30 minutes to 4 hours.

Next, this was ground into a predetermined shape using a whetstone to produce a magnetic core. The subsequent manufacturing steps are the same as those for normal magnetic heads.

And track width 0.6mm, Mi air gap 2μm
A magnetic head of the present invention was obtained.

The obtained magnetic head was crimped with a load of 3.4gr/lII+2
, the tape was run at a temperature of 23°C ± 1°C and a humidity of 65% ± 5%.
9 (at 3/sec, the amount of wear after 2500 hours was examined and was 7 μm.

This is a significant improvement in wear resistance compared to the wear amount of about 400 μm of the permalloy magnetic head.
In addition, in the case of sintered ferrite or single crystal ferrite,
Since it is about 10 μm, it can be seen that it is superior to magnetic heads using sintered ferrite or single crystal ferrite.

Furthermore, in the case of magnetic heads using sintered ferrite or single crystal ferrite, after about 1500 hours of use,
Holes and chipping appeared in the magnetic helad core, which caused inconvenience in use, but since the magnetic head of the present invention has viscoelasticity, no chipping or deformation was observed in the vicinity of the head gap.

In terms of magnetic properties, it has an initial permeability of 24,500, a maximum magnetic flux density of 8,640 gauss, a coercive force of 0.020e, a Curie temperature of 360°C, which are superior to conventional ones, and a specific resistance of approximately 160 x 10-6 Ω. cm, which has a higher value than a magnetic head using an alloy magnetic material.

Example 2 Weight ratio of iron 45, nickel 50, red phosphorus 5 (45 at%
A magnetic head using an amorphous magnetic metal was obtained in the same manner as in Example 1 by mixing Fe, 47 at% Ni, and 8 at% P.

Hardness is 720 and 25 at tape speed 19 cl/sec
The amount of wear after running the tape for 00 hours was 6 μm.

The specific resistance is t'ysxto-1iΩ・Cl11,
The initial magnetic permeability was 23,000, the maximum magnetic flux density was 7,000 Gauss, and the coercive force was 0.020e.

Example 3 Cobalt was mixed at a weight ratio of 88 and red phosphorus was 12 (79 at% Co, 21 at% P), and Example 1
A magnetic head using an amorphous magnetic metal was obtained in the same manner as above.

The wear amount was 8 μm when the tape was run for 2500 hours at a tape speed of 19 m/sec.

The magnetic properties were a maximum magnetic flux density of approximately 5000 to 6000 Gauss and a coercive force of 0.04 to 0.0808°. Hardness was 600-750.

Example 4 An amorphous metal plate was obtained using the same materials as in Example 1 and following the same steps.

Next, this is processed into the shape of a magnetic core by punching.
A thermosetting epoxy resin (@thickness 1 μl 11) is adhesively laminated at a curing temperature of 140° C. for 30 minutes to 4 hours, and the surface is polished.

The subsequent manufacturing steps are the same as those for normal magnetic heads. A magnetic head with a track width of 0.6 mm and a magnetic gap of 2 μm was obtained.

Note that the characteristics were no different from those of the magnetic head obtained in Example 1.

Example 5 Weight ratio of iron 90.3, red phosphorus 8.1, boron 1.6 (8
0at%Fe, 13at%P, 7at%B),
A magnetic head using an amorphous magnetic metal was obtained in the same manner as in Example 1.

When the wear amount was examined for 2500 hours at a tape speed of 19 cm/sec, it was 8 μm.

Magnetic properties include maximum magnetic flux density of 8000~1oooo Gauss, coercive force HO91~0°0500
Met. Hardness was 600-650.

Example 6 Iron 44, nickel 46.4, red phosphorus 8°5, boron i,
Weight ratio of i (40at%Fe, 40aL%Ni, 14
at%P, 6aL%B), and a magnetic head using an amorphous magnetic metal was obtained in the same manner as in Example 1. When the tape was run for 2500 hours at a tape speed of 19 cm/sec, the amount of wear was 6 μm. The hardness was 720.

The specific resistance was 175×10′Ω·cm, the maximum magnetic flux density was 8000 Gauss, and the coercive force was 0.030e.

As described above, the magnetic head of the present invention has higher wear resistance than conventional magnetic heads using ferrite, and has better magnetic properties and mechanical properties than conventional magnetic heads using alloy magnetic materials. It has a good balance of magnetic properties and wear resistance properties.

Further, in each of the above Examples, as a result of using an epoxy thermosetting resin, no peeling of the laminate occurred at all during grinding and polishing.

On the other hand, when the epoxy hardening resin is replaced with other thermosetting resins such as phenol, polyester, and melamine, or rubber and thermoplastic resins, the adhesive strength is low, and after grinding and polishing, Peeling occurred.

Table 1 below shows the number of peeled pieces per 100 samples when the adhesive was changed in each example. The adhesive used is as follows.

Table 1 also shows the values for permalloy.6 However, only rubber-based materials have high viscosity, and as they become thinner, the intermolecular bond strength weakens and they tend to peel off. The thickness of the agent was 5 μl.

Epoxy system: Epikylorhydrin-bisphenol A type Phenol system: Phenolic vinyl system (vinyl resin uses polyvinyl butyral) Polyester system: Polyester resin Rubber system: Nitrile rubber modified phenol resin From the results shown in Table 1, it is found that amorphous It can be seen that among surgical adhesives, only epoxy-based adhesives exhibit extremely high adhesion and/or mechanical strength when highly magnetic metals are used.

Next, the thin plates of each example were cut to a length of 15 mm and a width of 5 mm, and the central portion in the longitudinal direction was bent at a right angle to form an L-shaped thin plate, which was then subjected to a T-shaped peel test (Run 7).

That is, as shown in FIG. 1, two L-shaped thin plates 1.1' are used, the bent portions tt and ii' are facing outward, and the two are placed facing each other to form a T-shape. A layer of 1 μl of Adhesive 2 was applied to the sample. However, for the rubber-based adhesive layer, the amount was 5 μl.

A peel test was performed on this T-shaped sample by pulling the bent portions in opposite directions and applying force in a direction perpendicular to the adhesive layer.

The average values for 100 samples are shown in Table 2.
Note that Table 2 also shows the values for permalloy with a thickness of 120 μm.

The results shown in Tables 1 and 2 show that the combination of amorphous magnetic metal and epoxy adhesive provides significantly higher mechanical strength and adhesive properties than the conventional use of epoxy adhesives. I understand what is shown.

[Brief explanation of drawings]

FIG. 1 is a front view for explaining a peel test for confirming the effects of the present invention. 1.1'...thin plate, 2...adhesive applicant
TDC Co., Ltd. Representative Patent Attorney Yo Ishii −゛. Engraving of drawings (no change in content) FIG, 1. Procedural formalization (method) % formula % 2. Title of invention Method for manufacturing magnetic heads 3. Relationship to the case of the person making the amendment Patent applicant address Tokyo Nihonbashi-chome 13-1, Chuo-ku
Name (306) TDC Co., Ltd. 4, Agent 101 Phone: 864-4498 Address: 3-2-2 Iwamoto-cho, Chiyoda-ku, Tokyo January 28, 1986 (shipped) 6. Drawings subject to amendment 7 , content of correction

Claims (2)

[Claims] (1) When manufacturing a magnetic head with a magnetic circuit made of amorphous magnetic metal, a magnetic head characterized in that a thin plate of amorphous magnetic metal is bonded with an epoxy resin layer and then polished. Head manufacturing method. (2) The method for manufacturing a magnetic head according to claim 1, wherein the composition of the amorphous magnetic metal is represented by the following formula. MaYb (where M is at least one of Fe, Ni, and Co; Y is at least one of P, B, C, and Si; a = 60 to 95 at%; b = 5 to 40 at%; )