JPS62140209A - Production of alloy magnetic head - Google Patents

Abstract

PURPOSE:To provide a titled magnetic head having excellent output characteristics at a high frequency by forming thin two-layered films consisting of ceramics and lead-contg. glass as a nonmagnetic layer on the front gap forming surfaces of a pair of amorphous alloy magnetic cores and thin Ag-Cu-In alloy films having a low m.p. on the back gap forming surfaces thereof, then subjecting the cores to a heat treatment at a prescribed temp. CONSTITUTION:This right and left butt type magnetic head is constituted by sandwiching a magnetic material consisting of the amorphous alloy 2 which is a thin strips of Fe-Co-Si-B made by a liquid ultra-quick cooling method between glass substrates 1. The thin two-layered films consisting of the thin ceramic film 8 and thin lead-contg. glass film 9 are formed as the nonmagnetic layer on the front gap forming surfaces 6 of the right and left alloy magnetic cores 2. The thin Ag-Cu-In alloy films 10 are formed on the back gap forming surfaces of the alloy magnetic cores. The magnetic cores in the stage of mating the gap forming surfaces to each other is then subjected to the heat treatment in a nonoxidative atmosphere above the softening temp. of the lead-contg. glass and the temp. at which the liquid phase of the Ag-Cu-In alloy appears, by which the right and left magnetic cores 2 are diffusively joined and the magnetical gap is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for manufacturing an alloy magnetic head, and more particularly to a method for forming a narrow gap in an amorphous magnetic head that is compatible with high magnetic flux to achieve high-density magnetic recording.

Conventional technology In recent years, metal tapes, vapor-deposited tapes, etc. have begun to be used to improve magnetic recording density, but magnetic heads that support this require high saturation magnetic flux density magnetic core materials that are less prone to magnetic saturation near the magnetic core gap. be. Currently, amorphous alloys (such as Co-Zr-Nb alloys) and Sendust alloys (F
e-AI-3i series alloy) is used. In particular, amorphous alloys have various characteristics (such as no crystal magnetic anisotropy, high hardness, high resistivity ρ, and easy to obtain thin plate materials) due to the fact that they do not have organized crystals. , materials have been actively developed, including Co-Zr-Nb sputtered films and Fe-Co-3T.
Materials such as -B-based carbon amorphous have been announced. However, these amorphous alloys
There is an irreversible transition point at which crystallization begins from an amorphous state in a relatively low temperature range around ℃, so if processing for manufacturing magnetic heads is performed above this temperature, the magnetic properties will rapidly deteriorate. It also had a drawback. In particular, since the core material is exposed to high temperatures during the heat treatment process (simultaneously with the bonding process between the cores) during gap formation, the above-mentioned drawbacks were likely to occur.

As a countermeasure to this problem, a method has been considered in which the bonding is performed at a low temperature by using an organic adhesive at the bonding part, but since the area of the butt part to be bonded is too small, sufficient bonding strength for the head cannot be maintained. Therefore, conventional amorphous alloy magnetic heads use an amorphous alloy core made of, for example, Sin.

The head is made using a method in which the alloy core and the glass core are bonded together using an organic adhesive, and the glass cores are also bonded to each other. It had a structure with improved strength.

Problems to be Solved by the Invention However, in this method, the amorphous alloy cores are not bonded, and the mechanical Since the tape is only butted but not joined, magnetic powder, dust, etc. that fall off from the magnetic tape as the tape runs enters between the cores of the front gap formed by the butt, expanding the gap. There is a problem in that the accuracy of the gap decreases, that is, the head characteristics deteriorate.

Means for Solving the Problems In order to solve the above problems, the present invention forms a two-layer thin film of ceramics and lead-containing glass as a nonmagnetic layer on the front gap forming surface of an amorphous alloy magnetic core, and then Ag-Cu-In on the back gap forming surface of the alloy magnetic core.
After forming the alloy thin film, the softening temperature of the lead-containing glass and the Ag-C
By performing low-temperature heat treatment in a non-oxidizing atmosphere above the temperature at which the liquid phase of the u-In alloy appears, a magnetic head with high precision and high mechanical strength is provided.

Function The present invention involves forming ceramics and low melting point lead-containing glass on the front gap forming surface of an amorphous alloy magnetic core, and forming a low melting point Ag-Cu-In alloy on the back gap forming surface, and then joining two core plates. obtained by doing.

When a ceramic and lead-containing glass thin film is formed on the front gap forming surface of an amorphous alloy magnetic core, a very thin compound is formed at the interface between the ceramic and lead-containing glass through a chemical reaction, resulting in a gap with considerably strong mechanical strength. be able to. Furthermore, since the reaction layer occurs only on the surface, the gap width can be defined by the thickness of the stozm film and the lead-containing glass thin film.

Also, Ag-Cu-In formed on the back gap forming surface.
The composition of the alloy contains 30 to 60% by weight of In, and the remaining A
By g and Cu each being 10 at% or more,
The melting point of the alloy was 500° C. or less, and mutual diffusion between the amorphous alloy and the Ag-Cu-In alloy occurred, allowing strong bonding in a temperature range where the amorphous alloy does not crystallize.

Example Examples are shown below.

(Example 1) A navel piece having a structure as shown in FIG. 1 (81) was manufactured and examined by the method shown below.

Fe-Co produced by liquid ultra-quenching method as amorphous alloy
-31-13 thin strips were created. The composition of the alloy at this time was Fe: 5, Co, Ni 0. S i :10 and B
: 15at%. Next, the surface of this ribbon was mirror-polished (maximum surface roughness: Rmax O, 01 μm), and the thickness was made 30 μm. As shown in Figure 2 (al), this was cut to form the left and right core portions of the butt-type magnetic head.Next, glass plates with the same shape as the left and right amorphous alloy magnetic cores were prepared, and the As shown in Figure 2(b), the alloy magnetic cores were placed in between, and the alloy magnetic core and the glass plate were bonded together using an organic adhesive to obtain a pair of alloy magnetic cores.Next, the left and right sides of the butt-type magnetic head were Mirror polishing of the gap forming surface of the core (maximum surface roughness: Rmax O, 01
μm).

Next, as shown in FIG. 4 (al), a thin film of quartz (510,) was formed using a sputtering method on both front gap forming parts, and a lead-containing glass thin film was further formed thereon using the same sputtering method. The above-mentioned quartz thin film had a uniform thickness of 0.10 μm.On the other hand, the above-mentioned lead-containing glass thin film had a uniform thickness of 0.05 μm, and its composition was Pbo7.
It is a glass thin film consisting of 3at% and Sing of 27%. Next, an Ag-Cu-In alloy thin film of 0.15 μm was uniformly formed on both of the bonding portions of the back gap portion by the same sputtering method. The composition at this time is Ag: 40
at%, Cu was 30at%, and In was 30at%. The front gap and back gap sides obtained by these sputtering methods were brought into contact with each other to form a pair of chips in a vacuum atmosphere (10-'To
rn or less) at a temperature of 500°C for 1 hour,
The gap portion was bonded to obtain an amorphous alloy head piece. In order to examine the mechanical strength of the gap formed, a metal tape (coercive force HC: 1400 Oersted, saturation magnetic flux density B r: 3000 Gauss) was moved at a relative speed of 3.45 m to the running surface of the head.
I ran it for 500 hours at /sec. Observation of the gap at this time did not reveal any widening of the gap or occurrence of chips in the gap. Further, when a coil was wound with 25 turns in the winding groove of this head, the reproduction output voltage of the head at 6 MHz was 200 .mu.cm (peak-to-peak). The results are shown in sample number 1 in Table 1. Thereafter, in the same way, 5in2 of the front gap part was covered with other ceramics (Zr O!+ M g OlA I t Os+ T
i Ox and MgO.

AI! Sample numbers 2 to 6 in Table 1 show the results of various tests on samples in which one type of Os was used. Further, as a comparative example, a sample in which lead-containing glass was not used in the front gap (that is, a case in which the front gap was butted only with SiO□) was prepared in the same manner, and various tests were conducted. The results are shown in Sample Na7 in Table 1.

From this result, it is clear that the front gap is made of ceramic material (S).
tag , Zr0z , MgO,'Alz 03゜Ti
1t, MgO, A1.03) thin film and a glass thin film to form a gap, there is no change in the state of the gap after the tape runs, and a good reproduction output voltage can be obtained. I understand. As a comparative example, a case in which glass was not used in the front gap was shown, but in this case, the gap was chipped due to tape running, and the reproduction output voltage showed a low value of 80 μvp-p.

(Example 2) A headpiece having a structure as shown in Figure 1 was created and examined using the method shown below.

First, mirror polish the surface of the glass substrate (maximum surface roughness Rma
x O, 01 μm). Next, a 6 μm thick Co-Zr-Nb amorphous alloy magnetic film was formed on this surface by sputtering, and then a 0.01 μm thick StO film as a nonmagnetic layer was similarly formed thereon by sputtering. This operation was repeated to finally create a multilayer film with 31i magnetic films as shown in FIG. 3(a). The composition of the magnetic film at this time was Co: 85 at%.

Nb: 10 at% and Zr': 5 at%.

Next, as shown in Figure 3 (bl), the left and right core parts of the butt type magnetic head are cut, and the gap forming surfaces are mirror polished (maximum surface roughness Rmax 0.01).
#m) Shita.

Next, as shown in FIG. 4 (bl), a thin film of quartz (S i Ot ) was formed on both of the front gap forming portions by sputtering, and a lead-containing glass thin film was further formed thereon by the same sputtering method. Here, the above-mentioned quartz thin film had a uniform thickness of 0.10 μm.On the other hand, the above-mentioned lead-containing glass thin film had a uniform thickness of 0.05 μm, and its composition was Pb.
This is a glass thin film consisting of 73 at% o and 27 at% 5iOz. Next, by the same sputtering method, an Ag-Cu-In alloy thin film of 0.15 μm was uniformly formed on both of the bonding portions of the back gap portion. The composition at this time is
Ag is 60at%, Cu is 10at%, and In is 30at%.
It was at%. The front gap and back gap sides obtained by these sputtering methods were brought into contact with each other to form a pair of chips, and the chips were heated for 5 minutes in a nitrogen atmosphere.
Processing was performed at a temperature of 00°C for 1 hour to perform a bonding process on the gap portion, thereby obtaining an amorphous alloy head piece.

A test was conducted in the same manner as in Example 1 to examine the mechanical strength of the gap formed and the reproduction output voltage of the head. The results are shown in sample number 9 in Table 2. Below, various test results of samples in which the composition of the Ag-Cu-In alloy thin film in the back gap portion was changed in the same manner are shown in sample numbers 8 and 10 to 22 in Table 2. Here, in samples &8.12 and 22, bonding between the left and right cores could not be achieved by heat treatment.

Based on the results of Example 1 and above, Ag- formed on the back gap forming surface.
The composition of the Cu-In alloy thin film is 30~60at of In.
%, and the remaining Ag and Cu contained 10 at % or more each, there was no change in the gap state after tape running, and a good reproduction output voltage was obtained. This shows that the left and right cores are strongly bonded.

Here, in order to examine the diffusion state of the amorphous alloy and the Ag-Cu-In alloy, the bonded surface was forcibly peeled off, and elemental analysis in the depth direction of the surface was performed using Ausch electron spectroscopy. As a result, it was found that Ag and Cu interdiffused into the amorphous alloy, and Fe interdiffused into the Ag-Cu-In alloy.

In addition, this is noticeable when both Ag and Cu elements are contained at 10 at% or more, so the reason why sample &8.12 did not bond was due to mutual diffusion between the amorphous alloy and the Ag-Cu-In alloy. This is thought to be because there is no Also, sample N
Since the peeled surface of a22 was an Ag-Cu-In alloy, it is thought that if the amount of In is too large, the strength of the Ag-Cu-In alloy itself becomes weak.

Effects of the Invention As is clear from the above explanation and Table 1.2, the present invention forms a two-layer thin film of ceramic and lead-containing glass as a nonmagnetic layer on the front gap forming surface of a pair of amorphous alloy magnetic cores, and then After forming an Ag-Cu-In alloy thin film with a low melting point composition on the bank gap formation surface, low-temperature heat treatment is performed in a non-oxidizing atmosphere above the softening point of glass and the temperature at which the liquid phase of the Ag-Cu-In alloy appears. In this way, a magnetic head with high mechanical strength and a highly accurate gap can be obtained. Here, at the interface between the ceramic and the glass on the front gap forming surface, a chemical reaction occurs due to heat treatment, and a strong narrow gap can be obtained. In addition, the composition of the Ag-Cu-In alloy thin film intended for bonding between cores is 30 to 60 at% In, and the remaining Ag and Cu are each 10 at% or more, so the melting point is about 50%.
The temperature is extremely low, below 0°C, and there is no risk that the amorphous state will crystallize even during heat treatment during core-to-core bonding (which also forms a gap at the same time), significantly reducing the manufacturing constraints of amorphous alloy magnetic heads. . The magnetic head obtained by this method is significantly superior to conventional amorphous heads in terms of narrow gap precision during tape running and reproduction specific force characteristics at high frequencies, and is highly effective for 3W VTR, DAT, etc. It is expected that this material can be used as a magnetic head for high-density magnetic recording.

[Brief explanation of drawings]

FIG. 1 (al is Fe-Co-based on one embodiment of the present invention)
A perspective view of a 3i-B amorphous alloy magnetic head, FIG. 1 (bl is C in one embodiment of the present invention. A perspective view of a Zr-Nb amorphous alloy magnetic head, FIG. 2(a) is a Fe-Co- A perspective view of a pair of alloy magnetic cores obtained by cutting a 3t-B amorphous alloy ribbon into the shape of a butt-type magnetic head. Fig. 2(b) is a perspective view of this alloy magnetic core sandwiched between glass plates of the same shape. Fig. 3 (Al is a cross-sectional view when a laminated film of Co-Zr-Nb amorphous alloy thin film and Sin thin film is formed on a glass substrate, Figure 3 (
bl is a perspective view of a pair of core blocks cut into the shape of a butt-type magnetic head, and Fig. 4+a) is a perspective view of a pair of Fe-
Fig. 4 is a cross-sectional view when a gap material is formed in the gap forming part of the Co-3l-B amorphous alloy magnetic core.
is a cross-sectional view when a gap material is formed in the gap forming portion of a pair of Co-Zr-Nb amorphous alloy magnetic cores. 1...Glass substrate, 2...Fe-Co
-3i-B amorphous alloy ribbon, 3...
co-Zr-Nb amorphous alloy thin film, 4...
...SiO. Thin film, 5... Winding window, 6... Front gap forming surface, 7... Bank gap forming surface, 8... Ceramic thin film, 9... ...Glass thin film, 10. Old...Ag-Cu-In alloy thin film. Name of agent: Patent attorney Toshio Nakao (1 person) Figure 2
t ni/1-33 figure

Claims (3)

[Claims] (1) A left-right butt-type magnetic head made of amorphous alloy magnetic core material, in which a two-layer thin film of ceramics and lead-containing glass is formed as a nonmagnetic layer on the front gap forming surfaces of the left and right alloy magnetic cores, and then After forming a silver (Ag)-copper (Cu)-indium (In) based alloy thin film on the back gap forming surface of the alloy magnetic core, the softening temperature of the lead-containing glass and A magnetic alloy characterized in that a magnetic gap is formed by heat-treating in a non-oxidizing atmosphere at a temperature higher than the temperature at which a liquid phase of the Ag-Cu-In alloy appears, and diffusion bonding the left and right alloy magnetic cores. Head manufacturing method. (2) The ceramic thin film of the nonmagnetic layer is quartz (SiO_2)
, zirconia (ZrO_2), magnesia (MgO),
Alumina (Al_2O_3), titanium oxide (TiO_2
) and spinel (MgO, Al_2O_3), the method for manufacturing an alloy magnetic head according to claim (1). (3) Ag-Cu-I formed on the back gap forming surface
Manufacture of an alloy magnetic head according to claim (1), wherein the composition of the n-based alloy thin film is 30 to 60% by weight of In, and the remaining Ag and Cu are each 10% by weight or more. Method.