JPS61208607A - Magnetic head - Google Patents

Abstract

PURPOSE:To allow the bonding of the titled magnetic head to cope with the environment such as high temperature, low temperature or high humidity with a high bonding strength by bonding a head core and a reinforcement plate via at least two kinds of glass layers with different property. CONSTITUTION:A head core chip 1 is made of 'Sendust(R)', reinforcement plates 2a, 2b are made respectively of glass, and bonding glass layers 6a, 6b are formed to both faces of the head core chip 1 and a face of the reinforcement plates 2b, 2b opposed to the head core chip 1 by sputtering. Glass layers 7a, 7b for molten bonding are sputtered respectively on the bonding glass layers 6a, 6b and the head chip core 1 and the reinforcement plates 2a, 2b are overlapped so that the glass layers 7a, 7b for molten bonding are opposed and they are bonded by melting the glass layers 7a, 7b in a furnace. Two glass layers having similar thermal expansion coefficient are provided between the head core and the reinforcement plates so as to change gradually the thermal expansion rate. Thus, the magnetic head with high bonding strength and high reliability not causing loss of bonding even under the environment such as high temperature, low temperature or high humidity.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a magnetic head, and more particularly to a magnetic head having a structure in which a helad core and a reinforcing plate are stacked.

[Prior Art] In recent years, as the density of magnetic recording has increased, magnetic recording media have also changed, and magnetic alloys such as Sendust have come to be used for the heads and cores of magnetic heads.

However, such magnetic alloy materials are brittle and have poor wear resistance, so when a head core is constructed from a magnetic alloy material such as sendust, reinforcing plates made of glass, ferrite, etc. are laminated on both sides of the head core. It is common to do so.

Furthermore, a reinforcing plate is often used when the head core is made of an amorphous material.

A conventional magnetic head of this type is shown in FIG.

That is, in the same figure, what is indicated by the reference numeral 1 is a head core chip made by butting two core halves, and the reinforcing plate 2a,
2b is attached to the head core chip l via adhesive layers 3a and 3b.
are joined by sandwiching them from both sides.

Also, those indicated by code 4 are Helad gaps, and codes 5a~
5c is a winding groove.

However, in a magnetic head with such a structure, the head core chip 1 and the reinforcing plates 2a and 2b are generally bonded using an organic adhesive, so the head core chip and reinforcing plates may be bonded together in environments such as high or low temperatures, high humidity, etc. There could be a difference in depth between the disc and the board, causing spacing loss and a drop in output during recording and playback.

'Furthermore, when the reinforcing plates 2a and 2b contain a magnetic material, there is a drawback that variations in the thickness of the adhesive layers 3a and 3b cause variations in the electromagnetic conversion characteristics of the completed magnetic head. Ta.

On the other hand, even when bonding the bed core chip l and the reinforcing plates 2a and 2b with an inorganic adhesive, the coefficients of thermal expansion of the two are not the same, and for example, bonding with low melting point glass may have weak adhesive strength, or bonding between sendust and glass, etc. There were problems such as difficulty in joining with.

[Purpose] The present invention was made in view of the above-mentioned conventional problems, and it is an object of the present invention to provide a highly reliable magnetic head that has strong adhesive strength and can be used in environments such as high temperature, low temperature, and high humidity. The purpose is

[Example] Hereinafter, the present invention will be described in detail based on the example shown in the drawings.

FIGS. 2 and 3 illustrate an embodiment of the magnetic head according to the present invention. In both figures, the same or corresponding parts as in FIG.

In this embodiment, the head core chip l is made of sendust, and the reinforcing plates 2a and 2b are made of glass.

First, bonding glass layers 6a and 6b are formed by sputtering on both surfaces of the head core chip l and on the surfaces of the reinforcing plates 2a and 2b facing the head core chip l.

The glass layers 6a and 6b are made of glass having a coefficient of thermal expansion close to that of the Herad core chip 1 and the reinforcing plates 2a and 2b,
Glass layer 7a for fusion described later.

In addition to improving the wettability of 7b, the head core tip l
This serves to increase the bonding strength between the reinforcing plates 2a and 2b.

Next, glass layers 7a and 7b for fusing are sputtered onto the bonding glass layers 6a and 6b, respectively.

These fusion glass layers 7a and 7b include a bonding glass layer 6a,
Glass is selected as a material that has a coefficient of thermal expansion close to that of 6b and is easy to bond.

Thereafter, as shown in FIG. 3, the head core chip l and reinforcing plates 2a and 2b are stacked so that the glass fusing layers 7a and 7b face each other, and the glass fusing layers 7a and 7b are melted in a furnace. Complete the joint.

If such a method is adopted, even if there is a difference in the coefficient of thermal expansion between the head core and the reinforcing plate, the coefficient of thermal expansion will gradually increase by providing two glass layers with similar coefficients of thermal expansion between them. Since the structure can be changed, a magnetic head with high bonding strength and adaptable to various environments can be obtained.

If there is a large difference in the coefficient of thermal expansion between the head core and the reinforcing plate, bonding can be achieved by forming multiple glass layers while gradually changing the coefficient of thermal expansion in the same manner as in the above embodiment.

In addition, even in the case of materials that are extremely difficult to bond even if they are of the same material, such as the butt part of the head core, we can improve the wettability of the glass by providing multiple layers of glass for adhesion.
It is possible to improve the bondability and make the bond stronger.

By the way, in the above-mentioned embodiment, the glass layer was formed using sputtering, but it is also possible to form it by vapor deposition or ion blasting, and in that case, the same effect as described above can be obtained. can.

[Effects] As is clear from the above description, according to the present invention, a method is adopted in which the head core and the reinforcing plate are bonded via at least two glass layers made of different materials. Even if there is a difference in thermal expansion coefficient between the plates or the materials are difficult to bond to each other, it can be firmly bonded, and there will be no slippage even under various environments such as high temperature, low temperature, and high humidity. A highly reliable magnetic head can be obtained.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a conventional magnetic head, and FIGS. 2 and 3 illustrate a non-contact embodiment of the present invention. FIG. 2 is an exploded perspective view, and FIG. 3 is a perspective view. 1...Head core chip

Claims (1)

[Claims] 1. A magnetic head in which a reinforcing plate is superimposed and bonded to a head core, the head core and the reinforcing plate being bonded to each other via at least two types of glass layers having different properties.