JPH0240107A - Production of magnetic head - Google Patents

Abstract

PURPOSE:To work a magnetic gap depth with high accuracy and high yield by forming a chamfer to the end angle parts of a core formed with a gap depth reference groove. CONSTITUTION:The gap depth reference groove 4 is formed longitudinally to a joint surface 3 of a core stock 1 consisting of a ferromagnetic material having a large length, then track grooves 5 and a V groove 6 are formed on the same surface and a winding detaining groove 7 is formed on the opposite surface; thereafter, the angles at both ends in the longitudinal direction of the joint surface are chamfered 9. The winding detaining groove 7 and track grooves 5 are similarly formed to another core 2 consisting of a ferromagnetic material having a short length. A thin nonmagnetic film 8 consisting of SiO2, etc., is deposited as a gap spacer on the joint surface and, thereafter, the core stocks 1 are so superposed that the longer core stock projects to both sides. Glass is packed into the V-groove and the gap depth reference groove 4 and is melted by heating, by which the core stocks are integrally joined. The easy measurement of the gap depth with high accuracy is possible in this way and the magnetic head having stable performance is obtd. at the high yield without having possibility of failure, etc., during the course of the production.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) The present invention relates to a method of manufacturing a bulk type magnetic head for use in VTRs, FDDs, etc., and particularly relates to a method of machining the depth of a magnetic gear with high precision.

k-button shell 1 The conventional method for manufacturing a magnetic head is to produce a rectangular parallelepiped-shaped ferromagnetic core material 11 having the same dimensions as shown in FIGS. 3a-e.
12 is prepared, and a gap depth reference groove 16 is formed in one core material 11 in the longitudinal direction of the joint surface.

After that, the winding locking groove 14. ■Groove 13. 8102 where track grooves 17 are formed and become gap spacers on the bonding surfaces.
A non-magnetic thin film 20 such as .
It is integrally joined to another core material 12 having track grooves 17 formed therein by abutted glasses 18 and 19.

Next, the top end is viewed from the direction a as shown in Figure 3e yA! l
A magnetic head core chip was manufactured by polishing the magnetic head to a predetermined gap depth d while slicing it, and then slicing it into predetermined dimensions along chain lines T, A, .

However, in this method, the end face 21 of the core material 11.12,
Since 22 is generally not a mirror surface, it is difficult to observe optically, and the accuracy could only be determined by the gap depth d. Therefore, the special public
As disclosed in No. 8-12647, in order to be able to observe the gap depth reference groove even after joining and integration, the reference groove is formed so that it can be seen from the reference groove forming core or the other core, as shown in Figures 1 and 2. A method has been proposed in which the gap depth d is processed with high precision by overlapping and integrally bonding, observing the ridgeline of the gap depth reference groove at both ends, and polishing the top end.

By the way, when the method disclosed in Japanese Patent Publication No. 58-12647 is applied to an actual VTR chip, the core is thin, around 1 mm, and the winding locking groove, gap groove, etc. are thin. Since the gap depth reference groove is formed, the protruding part may be chipped or chipped during handling during the butting process, crow joining process, top edge polishing process, etc., and as a result, the gap depth reference groove cannot be observed. There were many.

In order to solve this problem, the present invention is characterized in that chamfers are formed at the end corners of the protruding core, or narrow grooves parallel to the end ridgeline are formed near the ends of the protruding core. This is what I did.

Step 1: By forming a chamfer on the protruding corner of the core end, it can be used in the butting process, glass bonding process, apex polishing process, etc. Because the protruding part has no corners, it can be hung on jigs, etc., or the core blocks can be attached to each other. This prevents the protruding parts from getting caught and causing chips.

In addition, by forming a narrow groove on the protruding core end,
Even if chips occur during handling, the thin grooves will stop them, making it possible to observe the gear and depth reference grooves in the remaining protruding parts.

FIG. 1 is a perspective view of a magnetic head core block according to one embodiment of the present invention, and FIG. 2 is a perspective view of a magnetic head core block according to another embodiment of the present invention.

This will be explained below with reference to this figure.

First, rectangular parallelepiped-shaped ferromagnetic core materials 1 and 2 of different lengths are prepared.
Prepare.

A gap depth reference groove 4 is formed in the longitudinal direction on the joint surface 3 of the long ferromagnetic core material 1, and then a track groove 5 is formed on the same surface. Similarly, the V-groove 6 is wound on the opposite side of the magnetic core 2, and the winding locking groove 7. After forming the trunk groove 5, a non-magnetic thin film 8 such as 5i02 is applied as a gap spacer to the bonding surface, and the longer core material 1 is butted so as to protrude from both sides, and the groove 6. The gap depth reference groove 4 is filled with glass, heated and melted, and integrally joined to obtain a magnetic head core block.

Thereafter, the top end is polished from the gap depth reference groove to a predetermined gap depth cl, and sliced at a predetermined pitch to obtain a magnetic hend core attenuator.

As mentioned above, the butting process and glass bonding process.

When handling the workpiece up to the top end polishing process, there are no corners in the protruding part, so jigs and tools or workpieces do not catch each other and cause chips. It is better if chamfering is performed not only on the end corners of the joint surfaces but also on the opposite surface.

An example in which the end of the protruding part is chamfered has been described above, but as a second embodiment, a thin groove 10 is formed near the end of the protruding part as shown in FIG. Even if chipping occurs, the chipping is stopped by the narrow grooves 10, and the gap depth reference groove can be observed in the remaining protruding portion, so that the same function as in the first embodiment can be achieved.

As explained above, according to the present invention, the gap depth can be measured easily and with high precision in the manufacturing of magnetic heads, so that magnetic heads with stable performance can be manufactured with high performance without worrying about breakage during the process. It is possible to obtain it in terms of yield.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a core block showing a first embodiment of the present invention, Fig. 2 is a perspective view of a core block showing a second embodiment of the invention, and Figs. FIG. 4 is a process schematic diagram illustrating core joining of the head. 1.2...Ferromagnetic core, 3...Joint surface, 4...Gap depth reference groove, 5...
Track groove, 6... V groove, 7... Winding locking groove, 8... Non-magnetic thin film (Si20), 9...
・・Chamfer, =7−

Claims (1)

[Claims] 1. (a) A gap depth reference groove is formed on the joining surface of one core material of a pair of ferromagnetic cores, and both ends of the groove protrude from the end of the other ferromagnetic core. (b) In a method of manufacturing a magnetic head, the gap depth reference groove is overlaid and integrated with the gap depth reference groove, and the areas near both ends of the gap depth reference groove are observed on the bonding surface side and polished to form a gap depth of a predetermined dimension. 1. A method of manufacturing a magnetic head, comprising forming a chamfer on an end corner of a core formed with a chamfer. 2. In the method of manufacturing a magnetic head according to claim 1(a), a narrow groove parallel to the end ridge line is formed in the bonding surface near the end of the core in which the gap depth reference groove is formed. A method of manufacturing a magnetic head characterized by the following.