JPH03265539A - Magnetic head - Google Patents

Abstract

PURPOSE:To raise the hardness of glass material to adhere a pair of core halves, to reduce cracking or chipping of glass during working, and to obtain a magnetic head of high reliability by using such a glass having a specified composition. CONSTITUTION:A magnetic head is manufactured by adhering a pair of core halves 8 each comprising a substrate 6 covered with a magnetic film 1 with glass material 4 in a manner that the magnetic films 1 face to each other through an insulating film 5 which acts as a magnetic gap. The glass material 4 has a composition of 70<=PbO<=75, 15<=B2O3<=23, 1<SiO2<5,2>ZnO<9, and 0<=Al2O3<5 (by wt.%). This glass material shows particularly high effect when the head is manufactured with using amorphous magnetic films as the magnetic films.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a magnetic head, and particularly to a magnetic head comprising a glass material suitable for use with an amorphous magnetic material as a magnetic film.

[Conventional technology]

2. Description of the Related Art As the density of magnetic recording increases, magnetic heads using amorphous magnetic materials with high saturation magnetic flux density as magnetic films have been developed. Regarding the characteristics of the glass material formed on the sliding surface with the tape conventionally used in this type of magnetic head, it is possible to use a low melting point glass as disclosed in, for example, Japanese Patent Application Laid-Open No. 63-298807. It had become mandatory.

[Problem to be solved by the invention]

When using the glass material according to the above-mentioned prior art, several problems have been found in mass production. In other words, if a magnetic tape with a high coefficient of friction is run at a high temperature of 40°C and high humidity of 90%, the glass part will wear unevenly and cause output deterioration.
Alternatively, if an attempt is made to stabilize the tape contact by increasing the core thickness of the head sliding surface to a few micrometers, problems such as chipping and chipping due to insufficient glass strength will occur, which will significantly reduce the head manufacturing yield. This required expensive glass materials.

The purpose of the present invention is to improve the glass material by increasing the Vickers hardness from 320 (HV) to 350 (HV), focusing on the fact that the glass material of the prior art has a low Vickers hardness of about 300. It is an object of the present invention to provide a highly reliable magnetic head that reduces chipping and chipping and is free from uneven wear even when a tape runs in sliding contact.

[Means for solving the problem] In order to achieve the above object, we changed the composition of the glass material to be filled and examined whether each of them had a large or small reaction with the amorphous material. It was investigated whether or not it was suitable for machining in terms of physical properties.

Furthermore, since an amorphous magnetic material is used as the magnetic film when filling and adhering the glass material, the amorphous magnetic material will crystallize at temperatures above the crystallization temperature of the amorphous film.
Its magnetic properties deteriorate. In other words, there is an upper limit to the processing temperature during filling and bonding, and when considering mass production, it is necessary to consider margins such as temperature distribution in the electric furnace and perform processing at a temperature as low as possible than the crystallization temperature of the amorphous magnetic material. There is.

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

The composition of glass is basically Pb0-B, O□-8i○,
It consists of five elements: -Zn○-AQ2O3, and each component is changed in various ways and shown as sample names A to F.

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

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

In Figures 5, 6, and 7, the softening point of glass is 4.
Despite the fact that there is almost no difference between 20 and 450 degrees Celsius,
Depending on the composition, the hardness and strength, as well as the degree of reaction with the amorphous magnetic material, etc., vary significantly.

It can also be seen that sample names E and F have greater effects on Vickers strength and bending strength than sample names A, B and C.

In machining, the higher the Vickers hardness, the less chipping and chipping, and the higher the yield.

In addition, the reaction of sample names E and F with the amorphous magnetic material is as small as possible, especially when compared with the glass of sample name A, the reaction of sample names E and E is about 173 or less, which is less effective. Significant.

Comparing sample names B and C with sample names E and F, the major difference is that the composition of SiO is 2-3%, and B
2O3 is 15-17%, and values around this range are shown to be effective.

[Effect]

If we take a comprehensive look at the above, we can see that the reaction with the amorphous magnetic film, processability, glass strength, etc. can be brought in favorable directions without changing the softening point of the glass.

The ability to process without raising the softening point is extremely effective in producing heads using amorphous magnetic material films. Conversely.

There are many other glasses that are preferable if the softening point can be raised. In the present invention, we are considering a bonding treatment temperature or heat treatment temperature that is approximately 40°C higher than the softening point, and the crystallization temperature Tx of the amorphous magnetic material film is set at 520 to 520°C.
The temperature is assumed to be around 550℃.

For example, in a Co-Nb-Zr amorphous magnetic material film, T
Assuming x to be about 520 to 550°C, a film with a saturation magnetic flux density Bs of about 0.9T to 1.0T can be obtained.

It is possible to write sufficiently on a metal powder tape with a He of 1,400 to 15,000 e.

〔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), 2 is an SiO 3 is a protective film made of Cr; 4 is a layer of glass material as a filler/adhesive (hereinafter referred to as a glass layer); 5 is a gap material made of Sio2; 6 is a base made of ferrite; 7 is a chevron forming surface;
7' is the chevron top of the chevron-forming surface, and -β- is the core half.

In the figure, the magnetic head consists of a pair of amorphous magnetic films 1 deposited on a chevron-shaped surface 7 formed on a base 6 made of ferrite, and an insulating film 2 and a protective film 3 deposited thereon. The core half l is placed through the gap material 5 so that the processed surfaces for regulating the track width, which are formed by grinding and lapping the amorphous magnetic film on the peak 7' of the peak forming surface 7, face each other. The core halves are butted together, a glass material is filled and heated on the protective film 3 between the chevron-forming surfaces 7 of the pair of core halves to form a glass layer 4, and the two core halves are bonded together.

Note that at this time, the gap material 5 is made of Sin.

is vitrified by a vitrification reaction with the glass layer 4, and is integrated with the glass layer 4 between the two core halves.

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

In the figure, one core half 8 is butted against the glass layer 4.
When filled, as described above, the gap material present on the processed surface (gap portion) for controlling the track width undergoes a vitrification reaction with the glass material and is uniformized as the glass layer 4.

However, when the pair of core halves are bonded together by filling this glass material, the vitrification reaction between the gap material 5 and the glass material at the bonded portion of the core halves is preferable from the viewpoint of adhesion. However, the vitrification reaction tends to extend not only to the bonded portion of the core halves but also to the gap portion. As a result, the track width regulation length (indicated by Tp in Figure 1) may become shorter, for example,
This is remarkable when sample name A glass in the figure is used.

In addition, the filled glass material also reacts with the amorphous magnetic material,
The glass material enters the amorphous magnetic material, causing deterioration of its magnetic properties such as increasing its He, which not only shortens the effective track width but also seriously affects the operation of the magnetic head.

The occurrence of the above situation is conceptually shown in Figure 2 as ■.

However, the occurrence of such a situation is limited to the glass material according to the present invention, that is, 70≦pbo≦75.15≦B20, ≦2
3. l < 5iOz < 5, 2 < Z n○ku9. o≦AQ, ○, 5. It can be reduced by using a glass material having a composition containing each weight percent.

For example, if the sample shown in Figure 5 is used as the glass material, in the magnetic helad with the structure shown in Figure 1,
The size of the reaction area ■ shown in Figure 2 is the sample name A.
This can be reduced to one-third or less of that when using glass material, and the length in the track width direction can be reduced to 0.2 μm or less.

This shortened length is practically negligible in practical terms, and as a result, the manufacturing yield of the head could be improved by more than 20%.

Furthermore, the glass material shown in FIG. 5 above can be subjected to filling and bonding operations with the same temperature profile as sample A, and there is no need to set any special conditions.

In addition, a magnetic head was created using the glass material with the sample name E in Figure 5, using the same process and the same profile as the glass material with the sample name. A magnetic head with low reaction with the amorphous magnetic material, little shortening of track width direction length due to vitrification reaction with the gap material, high precision, high reliability, and high yield was obtained.

In addition, as a result of running a magnetic head using a glass material with the sample name E for a long period of time and testing the degree of uneven wear and changes in output over time, there were no particular problems in any of them, and there was no problem at high temperatures. Good results were also obtained in tests in high-temperature atmospheres.

From this, the glass materials with sample names C-F in Fig. 5 are suitable as adhesive glass materials for the core half of a magnetic head using an amorphous magnetic material as the magnetic film, and in particular, the glass materials with sample names C-F are suitable. , F glass material is preferably used.

In addition, in the composition of FIG. 5, all numbers are shown as integers, but these are only approximate numbers, and as long as they are within the weight percentage range described in the examples, the numbers are not necessarily integers. You should be careful.

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

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 Sin film, 3 is a Cr film, 4 is a glass layer, and 5 is a Si film.
n is a film (gap material), 6 is a ferrite (substrate), 7 is a chevron forming surface, and 9- is a core half block.

In the figure, first, a plurality of chevron-shaped grooves are formed in ferrite, which will become the base body 6, using a dicing saw or the like to form a chevron-formed surface 7. Using a sputtering device, an amorphous magnetic material (for example, Co-Nb-
A magnetic film 1 is formed by depositing Zr) to a thickness of 20 to 30 μm. Next, the protective film 2.3 is formed. Here, the protective film 2 is formed of a Sin film to a thickness of 0.3 μm, and the protective film 3 is formed of a Cr film to a thickness of 0.5 μm using a sputtering apparatus.

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

As the glass material filled on the protective film, a glass material having a composition similar to the sample name shown in FIG. 5 is used.

This glass material is plate-shaped and placed on the chevron-forming surface.
By keeping the atmosphere at 470° C. for 20 minutes in an electric furnace, the chevron-shaped groove portions are filled.

After filling the glass material to form the glass layer 4, the filled surface is ground and lapped to expose the magnetic film 1 at the top of the chevron by an amount that regulates the track width (track width enlarging process).

The surface of the magnetic film processed for track width is usually o, os.
The mirror surface has a surface roughness of s (that is, the peak to peak of unevenness on the surface is 0.05 μm).

Next, gap material (SiC2) 5 that will become the bed gap
is deposited by sputtering to obtain one core half block 9.

FIG. 4 is a front view showing a state in which two core half blocks 9 (that is, a pair) in FIG. It corresponds to , the part is the core half of the helad chip, and the IO is the cutting part.

As shown in the figure, a pair of core half blocks 9°9- are
Their track width regulating surfaces are butted against each other and held at 473° C. for 20 minutes in the same N2 atmosphere electric furnace as described above to obtain an integrated head block that is adhered to each other.

Cut this head block at 10 cutting edges using a dicing saw or wire saw.

Use multiple helad chips.

One of the head chips thus obtained is shown in FIG. 1 above.

In the above manner, the magnetic head of the present invention can be manufactured.

〔Effect of the invention〕

As explained above, according to the present invention, the crystallization temperature of the amorphous magnetic material can be adjusted without increasing the processing temperature for filling and adhering the glass layer, that is, by setting the temperature to about 100° C. above the softening point of the glass material. By selecting a glass material with an optimal composition that can be processed as follows, it is possible to use the most suitable filled glass for the amorphous magnetic film, which improves processability, reduces reaction with the amorphous magnetic film, and has high wear resistance. This makes it possible to provide a magnetic head with high reliability.

[Brief explanation 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. Figure 2 is an enlarged view of the main parts of the magnetic tape sliding surface shown in Figure 1, Figure 3 is a front view of the core half block for manufacturing the core halves, and Figure 4 is the two core halves. A front view showing the blocks butted together, Fig. 5 is an explanatory diagram showing the composition of the glass material, Fig. 6 is an explanatory diagram showing the characteristics of the glass material shown in Fig. 5, and Fig. 7 is the same as Fig. 5. It is a graph diagram showing the hardness of the glass material shown and the bending strength of the glass material. DESCRIPTION OF SYMBOLS 1... Amorphous magnetic film, 2... SiO2 film, 3... Cr film, 4... Glass layer, 5... Sin, film, 6... Substrate. 7...Chevron formation surface, 7'...Chevron top, 8...Core half body, 9...Core half block, No. -Gafbuoo (siO2

Claims (1)

[Scope of Claims] 1. A magnetic head comprising a pair of core halves each having a magnetic film coated on a base, butted and bonded together using a glass material with an insulating film forming a magnetic gap between the two magnetic films. In the glass material, 70≦PbO≦75, 15≦B_
2O_3≦23, 1<SiO_2<5, 2<ZnO<9
, 0≦Al_2O_3<5, in each weight percent. 2. The magnetic head according to claim 1, wherein at least a portion of the magnetic film is made of an amorphous magnetic material containing Co. 3. The magnetic head according to claim 1, further comprising a magnetic film made of an amorphous magnetic material adhered to the chevron-formed surface of the base body formed in a chevron-shape, and the magnetic film on the top of the chevron-shaped surface has a track width. A pair of core halves each having a processed surface for regulation, an insulating film interposed between the magnetic films of the pair of core halves, and a chevron-formed surface excluding the processed surface of the pair of core halves. The core halves have at least a layer of the glass material bonded therebetween, and each of the processed surfaces of the pair of core halves are butted together with the insulating film interposed therebetween and bonded by the layer of the glass material. magnetic head.