JPH02276010A - Manufacture of magnetic head - Google Patents

Abstract

PURPOSE:To miniaturize a magnetic recording device, and to improve a magnetic characteristic by setting the cross section shape of a glass rod for magnetic core joining in a triangle. CONSTITUTION:The film of 'Sendust(R)' 2 to be ferromagnetic metal and the film SiO23 to be high fusion point glass are successively prepared by spattering on a core half body 1 of the abutting surfaces of core half bodies 1 and 4 worked to prescribed shapes. The core half bodies 1 and 4 are mutually abutted, back pressure is applied through a spacer 6 by a spring member 7, and the core half bodies are set to a jig 8. Next a glass rod 5 for magnetic core joining having a triangular cross section shape is set in an apex part 9 of the core. Thus the small magnetic recording device can be sufficiently coped with, and the excellent magnetic characteristic can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to a method of manufacturing a magnetic head used in a magnetic recording/reproducing device.

[Prior Art] A conventional method for joining a pair of magnetic core halves is disclosed in Japanese Patent Application Laid-Open No. 1986-50.
As shown in Figure 1 of No. 908, the two halves of the magnetic cores processed into a predetermined shape were butted against each other, a glass rod with a round cross section was inserted, and the two were welded together by heating.

In addition, the heating temperature during bonding is 10° below the softening point of glass.
It was carried out at a temperature of 0°C or higher.

In addition, as the density of magnetic recording increases, recording media with high coercive force are used, and in order to record information on such recording media, a ferromagnetic metal film such as Centast is formed near the ferrite. A magnetic head with a so-called metal-in-gap structure is used. Furthermore, with the miniaturization of magnetic recording devices, the size of the magnetic head is also required to be reduced.

However, the conventional technology has a problem in that a ferromagnetic metal film such as sendust and glass interdiffuse, resulting in deterioration of the magnetic properties of the magnetic head. Furthermore, when the magnetic head is made smaller, the space in which the glass for joining the magnetic core is inserted becomes smaller, making it difficult to set the glass rod in a predetermined position and making it difficult to control the amount of molten glass, which increases the strength of the joining. The problem is that the coil winding window becomes small or a part of the coil winding window is blocked.

[Problem to be Solved by the Invention 1] The present invention solves the above-mentioned problems, and provides a magnetic head with a metal-in-gap structure that can accommodate miniaturization of magnetic recording devices and has excellent magnetic properties. There is a particular thing.

[Means for Solving the Problems] The method for manufacturing a magnetic head of the present invention includes: (1) forming a ferromagnetic metal thin film and high melting point glass on the joint surfaces of a pair of magnetic core halves made of ferrite by vacuum thin film forming technology; In a magnetic head, a magnetic gap is formed by abutting the pair of magnetic core halves, inserting a glass rod for joining the magnetic core, and then heating and melting the pair, the cross-sectional shape of the glass rod for joining the magnetic core It is characterized by having a triangular shape.

(2) The glass rod for joining magnetic cores described in item 1 is characterized in that the temperature at which it is heated and melted is 20° C. or more and 50° C. or less than its softening point.

[Example] FIG. 1 is a side view showing a method for manufacturing a magnetic head of the present invention.

On the core half L on the abutting surface of the core halves 1 and 4 processed into a predetermined shape, 3 μm of Sendust 2, which is a ferromagnetic metal, and S, which is a high melting point glass, are applied by sputtering.
A film of 05 μm of iO□3 is sequentially formed. Said core half 1.4
are butted against each other and set in a jig 8 with back pressure applied by a spring member 7 via a spacer 6. Next, a magnetic core bonding glass rod 5 having a triangular cross-sectional shape is set in the apex portion 9 of the core.

As the glass rod 5 for joining the magnetic core, Pb0.50% by weight
:810□ :30wt%:A12035wt%;Na
The composition is 2O: 10% by weight: B2O3: 5% by weight,
Thermal expansion coefficient at 100-300℃ is 105
A glass having a softening temperature of 570°C was used.

The conditions for melting and joining were as follows: in an Ar gas atmosphere, at the working temperature and heating holding time shown in Table 1.

Table 1 The temperature for heating and fusing was set at 20°C or higher and 50°C or lower than the softening point of the glass for joining the magnetic core, because if the temperature is lower than 20°C, the reliability of the magnetic head will decrease due to poor joining strength. This is because when the temperature exceeds .degree. C., significant interdiffusion occurs between the glass and the ferromagnetic metal thin film or ferrite, degrading the magnetic properties of the magnetic head.

Table 2 shows the evaluation results for each sample produced as described above.

Table 2 Of the conditions in Table 1, No. 1.2 is within the scope of the present invention, and No. 3.4 is a condition for comparison.

The material of the core half 1.4 has a thermal expansion coefficient of 120X1
Mn--Zn ferrite having a temperature of 0-'/°C was used.

In addition, Fig. 2 shows a cross-sectional view near the apex part of sample No. 4.6 As shown in Fig. 2, the glass and ferrite react, and the gap depth Gd becomes unclear and the gap length G
1 is tapered in the gap depth direction. G1=0.
In a magnetic head with a diameter of about 5 μm, sufficient magnetic properties cannot be obtained unless the Gd is 53 μm. Therefore, an accurate gap length G1 cannot be obtained using normal manufacturing methods.

On the other hand, in the manufacturing method of the present invention, the vicinity of the apex part is
Since the processed shape is kept sharp, an accurate gap length G1 can be obtained, and since there is no reaction between the glass and the Sengest, it exhibits excellent magnetic properties.

From the above, the effects of the present invention are clear.

[Effects of the Invention] As described above, according to the method for manufacturing a magnetic head of the present invention, the cross-sectional shape of the glass rod for joining the magnetic core is triangular, so that the glass rod and the surface to be joined are flush with each other. Since they are in contact, there is no need to pour the glass as in the past, and it is therefore possible to heat and melt the glass at a lower temperature than in the past. In addition, by lowering the heating and melting temperature, it is possible to suppress the reaction between the glass and the ferrite and sendust, thereby making it possible to obtain a magnetic head with excellent magnetic properties.

Furthermore, since the cross-sectional shape of the glass rod for joining the magnetic core is triangular, the workability of setting the glass rod is significantly improved, and the glass rod has the effect of being fully compatible with small-sized magnetic recording devices.

[Brief explanation of drawings]

FIG. 1 is a side view showing a method of manufacturing a magnetic head of the present invention. FIG. 2 is a sectional view of the vicinity of the apex portion of a magnetic head manufactured under heating and melting conditions outside the scope of the present invention. l... Core half 2... Sengest 3... SiO Kisanbe Suzuki (and 1 other person) 2nd Leap

Claims (2)

[Claims] (1) A ferromagnetic metal thin film and high melting point glass are formed on the joint surfaces of a pair of magnetic core halves made of ferrite using vacuum thin film forming technology, and the magnetic core halves are butted to form a glass rod for joining the magnetic cores. 1. A method of manufacturing a magnetic head, wherein the glass rod for joining the magnetic core has a triangular cross-sectional shape in a magnetic head formed by heating and melting the glass rod after insertion to form a magnetic gap. (2) A method for manufacturing a magnetic head, characterized in that the temperature at which the glass rod for joining the magnetic core according to claim 1 is heated and melted is 20° C. or more and 50° C. or less than its softening point.