JPH06150230A - Magnetic head and its manufacture - Google Patents

Abstract

PURPOSE:To provide a highly reliable magnetic head of an oxide magnetic material or a highly reliable composite magnetic head using a metallic magnetic film in the vicinity of a gap which shows little reaction between a solder glass material of magnetic core half bodies and the other material constituting the magnetic head and high mechanical strength when it slides against a medium. CONSTITUTION:In a magnetic core half body, a metallic magnetic film 7 is formed at a face of an oxide metallic material 1 where a track groove 2 is provided. The magnetic core half bodies face each other via a non-magnetic gap material 3. A solder glass A is filled in the track groove 2 opposite to a sliding face of a medium and in a glass storing groove 4, and a solder glass B having a higher working temperature than the glass A is filled in the track groove 2 at the side of the sliding face. The glasses A, B bound in the vicinity of a winding groove 6. Accordingly, a highly reliable head as described above is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ring type magnetic head.

[0002]

2. Description of the Related Art In recent years, in TVRs, miniaturization and high density have been advanced, and further, development of a system which requires high density recording by a wide band signal has become active. In the midst of this trend, development of narrower tracks and higher saturation magnetic flux density is becoming more active in magnetic heads as well. For example,
Narrow track head made by precision processing of ferrite material,
A composite head in which a ferrite material and a metal magnetic material having a high saturation magnetic flux density are arranged near the gap has been considered.

A conventional magnetic head and its manufacturing method will be described below. 4 and 5 show a conventional magnetic head. In FIG. 4, reference numeral 11 is an oxide magnetic material such as ferrite, and the protrusions regulated by the track grooves 12 face each other with a nonmagnetic gap material 13 interposed therebetween. The track groove 12 and the glass reservoir groove 14 are filled with a glass material 15 for bonding the magnetic core halves. Reference numeral 16 is a winding groove. In FIG. 5, the track groove 1 of the oxide magnetic material 11 is shown.
The magnetic core half body in which the metal magnetic film 17 is formed on the surface on which 2 is formed is bonded with the glass material 18 suitable for the metal magnetic film 17 via the non-magnetic gap material 13 as in the head of FIG. Has been done.

The method of manufacturing the magnetic head shown in FIG. 5 is as follows. As shown in FIG. 6A, the oxide magnetic material 11
The glass reservoir groove 14 and the winding groove 16 are formed on one surface 11a of the above, and the surface 11a is polished to a mirror surface. As shown in FIG. 6B, a plurality of track grooves 1 that are substantially orthogonal to the winding grooves 16 are formed on the surface 11a.
Create 2. As shown in FIG. 6C, a metal magnetic film 17 is formed on the surface 11a side, and this is used as a magnetic core half a. As shown in FIGS. 6D and 6E, the magnetic core half body b forming a pair with the magnetic core half body a (the glass core groove and the winding groove may not be provided in the magnetic core half body b) After the non-magnetic gap material 13 is formed in at least one of them, the glass material 18 is put into the glass reservoir groove 14 and the winding groove 16 by abutting the track portions regulated by the track groove 12, and the glass material 18 is heat-treated. Is melted and the magnetic core halves a and b are bonded to obtain a core block. After that, surface 11b, surface 11c
Is polished to a predetermined head height. As shown in FIG. 6 (f), the head of FIG. 5 is formed by cutting at a predetermined thickness and azimuth angle. At this time, the surface 11b becomes the medium sliding surface.

Similarly in the magnetic head of FIG. 4, in the conventional example, regarding the adhesion of the magnetic core halves, there is a method in which the glass material is melted by heat treatment at a predetermined temperature which is related to the characteristics of the magnetic head. It is used.

[0006]

However, the above conventional structure has various problems as described below.

Since the system is miniaturized and high density recording is required, higher reliability is required for the medium and head interface. The mechanical load is increased and the track is narrowed, so that the sliding ratio of the glass material, which has many problems in terms of reliability, to the medium sliding surface increases. Therefore, as shown in FIG. 7A, there is a problem that the reliability is deteriorated due to the surface roughness 19 of the glass material and the scratches 20.

On the other hand, the glass material to which the magnetic head halves are bonded contains some kinds of additives for controlling the melting point, and these additives are oxide magnetic materials when the glass material is melted. Reacts with metal magnetic films. For example, as shown in FIG. 7B, the erosion 21 in the gap portion caused by the reaction between the glass material and the oxide magnetic material causes deterioration of characteristics. Particularly in a magnetic head having a metal magnetic film formed as shown in FIG. 5 which is suitable for high density recording, a glass material having a lower melting point is used because the characteristics of the metal magnetic film are secured. Therefore, the reaction between the glass material having a large content of the additive and the metal magnetic film becomes more intense. For example, as shown in FIG. 7C, the alteration 22 of the metal magnetic film and the precipitation 23 of crystals occur due to the reaction. In this case, the alteration 22 causes characteristic deterioration, the crystal precipitation 23 lowers the transparency of the glass and makes it difficult to confirm the gap depth, and the precipitation portion particularly causes surface roughness and scratches on the medium sliding surface side, which is reliable. Reduce sex.

The present invention solves the above-mentioned problems of the prior art, and is a highly reliable magnetic head using a glass material for the medium sliding surface, which is less reactive with the head constituent material and stronger in mechanical strength compared to the present situation. The purpose is to provide.

[0010]

In order to achieve this object, the magnetic head of the present invention comprises an adhesive glass material A which is not exposed on the medium sliding surface, and a working temperature higher than that of the adhesive glass material A on the medium sliding surface. The magnetic head is characterized by having an exposed adhesive glass material B.

[0011]

With this structure and manufacturing method, since a glass material having a higher working temperature than that of the glass material forming the conventional head is used for the medium sliding surface, the mechanical strength can be improved. Furthermore, it is possible to reduce the amount of additive material contained in the glass material and to suppress the reaction with materials that come into contact with the glass material such as oxide magnetic material and metal magnetic film by press-fitting the glass material below the working temperature. The deterioration of the material and the precipitation of new crystals can be suppressed.

Therefore, it is possible to supply a head having excellent reliability on the medium sliding surface.

[0013]

【Example】

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 is an oxide magnetic material such as ferrite, and a metal magnetic film 7 is formed on the surface of the oxide magnetic material 1 on which the track grooves 2 are formed. The pair of magnetic core halves face each other via the non-magnetic gap material 3 with the protrusions regulated by the track groove 2 abutting against each other. The track groove 2 and the glass reservoir groove 4 are filled with a glass material for adhering the magnetic core halves, but the adhering glass material A, the medium sliding on the medium sliding surface and the opposite side of the winding groove 6 as a boundary. The surface side is filled with an adhesive glass material B having a working temperature higher than that of the adhesive glass material A.

The method of manufacturing the magnetic head according to the first embodiment is as follows. As shown in FIG. 2 (a), a glass reservoir groove 4 and a winding groove 6 are formed on one surface 1a of the oxide magnetic material 1,
The chamfer 5 is applied to the corner formed by the medium sliding surface 1b and the surface 1a,
The surface 1a is polished to a mirror surface. As shown in FIG. 2B, a plurality of track grooves 2 which are substantially orthogonal to the winding grooves 6 are formed on the surface 1a. As shown in FIG. 2C, the metal magnetic film 7 is formed on the surface 1a side.
Is created, and this is referred to as a magnetic core half a. As shown in FIGS. 2D and 2E, the magnetic core half b that forms a pair with the magnetic core half a (the glass core groove and the winding groove may not be provided in the magnetic core half b) After the non-magnetic gap material 3 is formed in at least one of them, the adhesive glass material A is put in the glass reservoir groove 4 by abutting the track portions regulated by the track groove 2, and the adhesive glass material having a higher working temperature than the adhesive glass material A. The material B is fixed to the chamfered portion 5 and pressed. In that state, heat treatment is performed at the working temperature of the adhesive glass material A to fill the adhesive glass materials A and B, and the magnetic core halves a and b are adhered to obtain a core block. Then, the surfaces 11b and 11c are polished to a predetermined head height. As shown in FIG. 2F, the magnetic head shown in FIG. 1 is obtained by cutting at a predetermined thickness and azimuth angle. At this time, the surface 2 becomes the medium sliding surface.

In order to determine the adhesive glass material B, a head was produced using each glass material having the glass transition point Tg and the working temperature Tw shown in (Table 1). At this time, as the adhesive glass material A, a conventional glass having a working temperature of 495 ° C. was used, and the heat treatment temperature was 495 ° C.

[0017]

[Table 1] FIG. 8 shows how the reaction layer thickness between the glass and the metal magnetic film and the defective filling rate of the glass into the track groove are affected by the working temperature of each adhesive glass material B pressed at 495 ° C. Is shown. As can be seen from this figure, if the adhesive glass material B has a working temperature higher than the heat treatment temperature of 495 ° C. by 25 to 30 ° C. or more, the reaction can be suppressed. Further, the adhesive glass material B was press-fitted below its own working temperature, but the limit for filling the track groove was around 560 ° C. From the above results, it is possible to select, as the adhesive glass material B, one having a working temperature of around 530 ° C to around 550 ° C.

Although the tellurite type glass material is used in FIG. 8, the relationship as shown in FIG. 8 is the same in other types. The same effect can be obtained by press-fitting the adhesive glass material B, which has a higher working temperature than the adhesive glass material A at the working temperature of the adhesive glass material A, though there are differences in the reaction and the difference in the glass filling limit temperature due to the difference in the system. To be For example, in the borosilicate type, as the adhesive glass material B,
It was possible to select one having a working temperature of around 520 ° C to around 540 ° C.

The characteristics of the magnetic sliding surface of the magnetic head according to the present embodiment are shown in Table 2 in comparison with the conventional magnetic head. The working temperature of the adhesive glass material B used is 540 ° C.
I used the one.

[0020]

[Table 2] As is clear from this (Table 2), the magnetic head according to the present embodiment has an excellent effect in terms of reliability on the medium sliding surface.

As described above, the glass having a higher working temperature than usual is press-fitted at a temperature lower than the working temperature and provided as the adhesive glass on the medium sliding surface side, whereby the mechanical sliding portion has a high mechanical strength and the metal sliding portion has a high mechanical strength. A highly reliable magnetic head with less reaction with the magnetic film can be realized without the reaction prevention film or other measures for preventing the reaction.

(Second Embodiment) A second embodiment of the present invention is shown in FIG. 1 is an oxide magnetic material such as ferrite,
The protrusions regulated by the track grooves 2 face each other with the non-magnetic gap material 3 interposed therebetween. The track groove 2 and the glass reservoir groove 4 are filled with a glass material for adhering the magnetic core halves, but the adhering glass material A, the medium sliding on the medium sliding surface and the opposite side of the winding groove 6 as a boundary. The surface side is filled with an adhesive glass material B having a working temperature higher than that of the adhesive glass material A. Also in FIG. 3, the adhesive glass material B is heat-treated at the working temperature of the adhesive glass material A and press-fitted in the same manner as when the head having the configuration of FIG. 1 is manufactured.

In this embodiment, since there is no metal magnetic film, the adhesive glass materials A and B are different from those used in Embodiment 1 in that the glass material having a high working temperature and high reliability is used. However, the erosion 21 at the gap portion due to the reaction between the glass material and the oxide magnetic material, which has been conventionally generated, as shown in FIG. 7B, was not observed.

[0024]

As described above, the present invention has the adhesive glass material A that is not exposed on the medium sliding surface and the adhesive glass material B that has a higher working temperature than the adhesive glass material A and is exposed on the medium sliding surface. The present invention realizes a magnetic head having excellent reliability in the medium sliding portion.

[Brief description of drawings]

FIG. 1 is a perspective view of a magnetic head according to a first embodiment of the invention.

2A to 2F are explanatory views of respective steps of the magnetic head manufacturing method in the first embodiment.

FIG. 3 is a perspective view of a magnetic head according to a second embodiment of the invention.

FIG. 4 is a perspective view of a conventional magnetic head.

FIG. 5 is a perspective view of a conventional magnetic head.

6A to 6F are explanatory views of respective steps of the conventional magnetic head manufacturing method shown in FIG.

7 (a) to 7 (c) are explanatory views of problems of a conventional magnetic head.

FIG. 8 shows the relationship between the reaction layer thickness between the glass-metal magnetic film and the glass filling failure rate and the working temperature of the adhesive glass B in the first embodiment.

[Explanation of symbols]

 1 Oxide Magnetic Material 2 Track Groove 3 Non-Magnetic Gap Material 4 Glass Reservoir 5 Chamfer 6 Winding Groove 7 Metal Magnetic Film 11 Oxide Magnetic Material 12 Track Groove 13 Non-Magnetic Gap Material 14 Glass Reservoir 15 Glass Material 16 Winding Groove 17 Metal magnetic film 18 Glass material 19 Surface roughness 20 Scratch scratch 21 Erosion of gap area 22 Reaction of metal magnetic film 23 Crystal precipitation A Adhesive glass material B Adhesive glass material with a higher working temperature than Adhesive glass material a Magnetic core half Body b Magnetic core half

Claims (3)

[Claims] 1. A pair of magnetic core halves made of an oxide magnetic material, or a pair of magnetic core halves each having a metal magnetic film formed on the abutting surface of the oxide magnetic material are butted to each other via a non-magnetic material. In the magnetic head having the magnetic gap thus formed, the adhesive glass material A not exposed on the medium sliding surface
And a bonding glass material B having a working temperature higher than that of the bonding glass material A and exposed to the medium sliding surface. 2. A glass reservoir groove formed on at least one of a pair of substrates made of an oxide magnetic material and having abutting surfaces polished to a mirror surface.
Step (a) of forming a winding groove for winding and chamfering the corner made up of the medium sliding surface and the abutting surface, and substantially orthogonal to the winding groove on the abutting surfaces of the pair of substrates. The step of forming a plurality of track restricting grooves for leaving the track portions (b), the step of forming a gap spacer made of a non-magnetic material on the abutting surface (c), the abutting of the track portions of the pair of substrates, and the glass reservoir groove. To the chamfered portion, and the adhesive glass material B having a working temperature higher than that of the adhesive glass material A is put into the chamfered portion, and heat treatment is performed at the working temperature of the adhesive glass material A while pressing only the adhesive glass material B. And a step (d) of adhering the substrate to the magnetic head. 3. The magnetic head manufacturing method according to claim 2, further comprising a step (e) of forming a metal magnetic film on the abutting surface after the step (a) or the step (b). Magnetic head manufacturing method.