JPS61110316A - Production of magnetic head - Google Patents

Abstract

PURPOSE:To charge melt-sticking glass uniformly and to attain low-temperature molding by pressing a solid glass rod forcibly onto a core block where track grooves are formed, and heating and molding the rod. CONSTITUTION:Recessed parts (track grooves) 11 of about 100mum in width are formed in core block half bodies 7 and 8 of a core block assembly 10, round rods of low-fusion-point glass 17 are placed on its peak surface 16, and a piston type weight 18 is mounted. The assembly 10 in this state is put in a container 15 and set in a heating furnace to perform molding while pressing the assembly forcibly. Therefore, the glass 17 in a fused state is pressed by the weight 18 and charged in the grooves 11 uniformly to mold the entire surface of the peak surface uniformly. Further, a low-temperature treatment is performed because of the molding in a loaded state, and the reliability of the production is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a technique for molding a core with a recess in a method of manufacturing a magnetic head.

The magnetic head, which is an element that magnetically records on a direct recording medium or reproduces minute magnetization recorded on the medium, has not only high magnetic permeability but also high saturation magnetic flux density and low coercive force. However, a core made of soft magnetic material with excellent wear resistance is required. Therefore, Mn-Zn and N1-Zn ferrites have been popular in the past, and recently, sendust alloy cores that exhibit higher saturation magnetic flux density characteristics have appeared.

In these magnetic head cores, the core halves are butted together and glass molded to protect a magnetic gap formed in a part of the butted portion. That is, taking a Sendust alloy core as an example, as shown in FIG. % of the core block halves 7 and 8 each formed with several dozen cores.
They are bonded with an adhesive 9 such as Ag solder to form a fab rotor assembly lO, and then a track groove 11, which will be described next, is bonded.
．． 11. It is set up and molded in glass.

In other words, since the magnetic gap 12 is formed at the center of the top along the longitudinal direction of the assembled body IO, first, with a pinch of the thickness of one core, the magnetic gap 12 is formed parallel to the short direction of the assembled body IO. Grooves 11.11, . . . are formed by cutting, and the magnetic gap is +2.12. The track width dimension of . . . is set to be the width dimension t of the protrusion. Next, the fourth
As shown in the figure, trunk grooves 11, 11.・・・・・・
For example, low melting point glass 13 is molded on the entire top surface including the magnetic gap +2.12. After the protection of ......, the top surface is polished to a curved surface, and the thin wire 14.14.・・・
It is sliced along ... to form individual cores.

ll　　　　゛　.

By the way, the magnetic head core described above has a thin wire of 14°14
The slice interval between them, that is, the core thickness dimension, is at most a hundred and several tens of μm, and therefore, the track grooves ti, +i
The width dimension T of , . there were.

With this drawback, it is naturally impossible to perform uniform molding, and as a result, when slicing the assembled body 10, the magnetic gap 12
,12. protection is incomplete and the magnetic gap 12.1
2. This could lead to deformation or damage.

This invention has been proposed with the aim of solving the above-mentioned problems, and has the effects as will become clear from the embodiments described later.

In manufacturing a magnetic head core, for example, using a sendust alloy core, this invention can be used to fabricate a large number of cores each having recesses such as an adhesive reservoir groove, a winding pass-through groove, a winding locking groove, etc. In the step of molding glass for welding onto the core block, a method is adopted in which solid glass is heated and molded while being forcibly pressed onto the core block. In other words, in contrast to the conventional method of molding glass by filling a cavity with powdered glass or simply heating a rod-shaped glass, this invention can mold glass in a solid form, that is, in a rod.
The feature is that the glass in the form of a plate or a chip piece is heated by forcible pressing, that is, by means of applying a load, etc., to melt and fill the glass.

1. By adopting the above-described means, the molten liquid glass is evenly pressurized in the mold area including the recess of the core block, and a uniform mold can be realized. Furthermore, since the present invention pressurizes the glass while heating it, it becomes possible to mold the glass in a state where the viscosity of the glass is higher than before, that is, at a low temperature.

Figure 1 is a conceptual diagram relating to one embodiment of the present invention, showing the case of a sendust alloy core, and is similar to the conventional explanation in Figure 4.
The core block assembly IO1 shown in the figure, that is, the core block halves 7 and 8 are joined, and the track grooves II, II,...
...is formed. First, the core block assembly IO is housed in a container 15 formed of graphite into a cylindrical shape with a bottom and whose entire surface is coated with a thin film of Cu. Then, the track groove II of the stored core block assembly IO, 11. ...and magnetic gap 12
．． 12. As shown in the perspective view in FIG. 2, on the top surface 1G where ... is formed, a round bar-shaped low melting point Pb glass 17.1? is formed over the entire top surface 16. ,...
... is placed on the bale pile. Then, there are further round rod-shaped Pb glasses 17, 17. . . . A piston type weight I8 is mounted on the top, which is fitted into the upper opening of the container 15 and serves as a pressing body that applies a load of, for example, about 1 g.

Here, the material of the weight 18 is graphite coated with Cu on the surface, similarly to the container 15. In addition, the container 15 and the weight 18 are made of Cu.
Although graphite has low compatibility with Pb glass, it is coated with PbO, which is a component of Pb glass.
There is a chemical reduction effect that causes the molded Pb glass to blacken, and the magnetic gap 12, 12. -This is to avoid making it difficult to set the depth dimensions of the old...

In this way, in this example, the round bar-shaped Pb glass 17
,17. ... is confined within the side wall of the container 15, the top surface 16 of the core block assembly lO, and the bottom surface of the weight 18, so it is placed in the heating furnace with this invitation and forcedly pressed. Glass molding can be done while the glass is being molded. That is, in this example, Pb glass +7.17.
. . . are pressurized and heated, the Pb glass 17, which has become a molten liquid, flows into the narrow track grooves 11, 11 . - Old... It is poured over the entire top surface 16, including the inside, and molded uniformly. Moreover, since the Pb glass is molded under a load by the weight 18, molding can be performed even when the heating furnace is at a relatively low temperature and the viscosity of the glass is higher than before.

Further, the magnetic head core to which the present invention is applied may be other than a sendust core, such as a ferrite core or an amorphous core.

According to the present invention, in manufacturing a magnetic head, the welded glass of the core can be uniformly molded, and low-temperature welding can be performed, thereby improving the reliability and mass productivity of the core manufacturing work. That is, in this invention, the glass to be molded is made into a solid shape and the forcible pressing is controlled to induce the above effect, so that the amount of glass molding can be set to a specified amount, and the polishing and slicing operations after joining the core blocks can be performed. Make it significantly easier.

[Brief explanation of drawings]

Fig. 1 is a conceptual diagram of an embodiment of the present invention, Fig. 2 is a perspective view of the core block assembly in a state in which solid glass is placed and pressed, and Fig. 3 is a conventional view of the core block assembly. FIG. 4 is a perspective view of the core assembly with track grooves formed therein, and FIG. 4 is a perspective view of the glass-molded assembly. 10...Core block, 11...Concave portion (track groove), 15...Container, 1B...Top surface, 17...Solid glass (rod shape), 18... - Weight (pressing body).

Claims (1)

[Claims] When manufacturing a magnetic head core, in the step of glass molding a core block in which a predetermined recess is formed, solid glass is heated and molded while being forcibly pressed onto the core block. Method.