JPH022206B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a magnetic head, and more particularly to a method of manufacturing a magnetic head, which includes a step of fitting a head element into a shield case, filling it with resin, and fixing the head element.

Generally, magnetic heads used for recording, playback, or both recording and playback are shielded with a case made of magnetic metal such as permalloy to prevent the influence of external magnetic fields. This shield case has an opening to expose the magnetic core.
Normally, everything except the opening that exposes the magnetic core is shielded with a shield case.

Conventionally, in the manufacturing method of such a magnetic head, the step of filling and fixing with resin involves providing an opening in the shield case, inserting the head body or core support assembly so that the magnetic core faces the opening, and then filling the shield with resin. It was filled and fixed.

FIGS. 1 to 5 illustrate the filling and fixing process of this conventional manufacturing method. As shown in Fig. 2, there is an opening 3 on the side of the head of the shield case 3.
a. A retaining convex portion 3b that protrudes inward is provided on the upper part of the back surface. The core support assembly 4 is constructed by sandwiching a magnetic core 1 consisting of a one-channel core 1' and a two-channel core 1'' with a shield plate 2 sandwiched between the head and a pair of left and right supports 4' and 4''. Further, a bobbin coil 6 is wound around the other end of the magnetic core 1.
The ends of the windings are connected to conductive terminals 7 forming legs. Furthermore, grooves 4a into which built-in springs 5 are fitted are formed on the upper surfaces of the supports 4', 4'' in the drawing.
As shown in FIG. 3, the core support assembly 4 having such a structure is press-fitted into the shield case 3 by fitting the built-in spring 5 into the groove 4a, and then filling resin 8 is injected from the direction of arrow A. The filling resin 8 fills and encapsulates the core support assembly 4 while embedding the retaining protrusion 3b, and then hardens to fix the core support assembly 4. However, at this time, if the filling resin 8 has low viscosity, it will flow out from the opening 3a before it hardens as shown in FIG. 4, and the upper part of the core support assembly 4 will not be filled. The fixing becomes uncertain and the filling resin 8 is wasted. However, on the other hand, if the filling resin 8 has a high viscosity, it may stick to the side surface of the core support assembly 4 or create bubbles in the middle, as shown in FIG. 5, and the lower part will not be filled. Lower part or opening 3a
If the periphery of the magnetic tape is not filled, its side edges will be exposed and cause damage to the magnetic tape. Furthermore, if the area around the lower retaining convex portion 3b is not filled, the fixation of the core support assembly 4 will become uncertain, and the core support assembly 4 will be subject to force on the head of the magnetic core 1 facing the opening 3a. If it is applied, it will move in the direction of the conductive terminal 7. If this happens, not only will the side edges around the opening 3a be exposed, causing damage to the magnetic tape, but also the head of the magnetic core 1 will retreat from the opening 3a, resulting in poor contact with the magnetic tape. . Further, the conductive terminal 7 protrudes in the direction of arrow A when filling resin 8 is injected, and the injection must be performed while avoiding the conductive terminal 7 so that the filling resin 8 does not adhere to it and become insulated. However, since the size of the shield case is small, it is difficult to inject while avoiding the conductive terminals 7, and the filling resin 8 may inevitably adhere to the conductive terminals 7.

The present invention has been made to solve the above-mentioned drawbacks. When the head element is filled and fixed in the shield case with resin, the head element is securely fixed without any unfilled parts, and the magnetic core is fixed. It does not retreat from the opening, the side edges around the opening are not exposed, and there is no waste due to outflow of the filled resin, and the filling process is easy, and the filled resin does not adhere to conductive terminals etc. during injection. The object of the present invention is to provide a method for manufacturing a magnetic head that does not cause problems.

In order to achieve this purpose in the present invention,
With the opening of the shield case closed, first inject a certain amount of filling resin, then press fit the head element into the shield case, and after the filling resin hardens, close the opening of the shield case. We adopted a configuration in which the magnetic core faces the opening.

The details of the present invention will be explained below based on embodiments shown in the drawings. Embodiments of the present invention are shown in FIGS. 6 to 11, and the same parts as in FIGS. 1 to 5 are denoted by the same reference numerals, and the explanation thereof will be omitted. In the embodiments shown in FIGS. 6 to 9, a convex portion B is formed in the side surface of the head of the shield case 3 which will eventually become the opening, and protrudes by the space into which the head of the magnetic core 1 will fit. There is. In this configuration, first, a predetermined amount of filling resin 8 is injected into the shield case 3. The amount is approximately equal to the internal volume of the shield case minus the volume of the core support assembly 4. The injected filling resin 8 accumulates in the lower part of the shield case 3 as shown in FIG. 8, and at this time, air bubbles in the resin are discharged to the upper part. Next, the core support assembly 4 is assembled and press-fitted into the shield case 3 while pressing the spring 5. shield case 3
The filling resin 8 accumulated inside the shield case 3 rises from the bottom to the top of the shield case 3 while embedding the protrusion 3b, fills the shield case 3, and then hardens to remove the core support assembly 4 from the shield case. Fixed within 3. Finally, the magnetic core 1
faces the opening, and the magnetic head is completed.

In this method, the filling resin 8 is injected into the shield case 3 in advance in an amount approximately equal to the volume of the core support assembly 4 subtracted from the volume inside the shield case 3, so that the filling resin 8 is stored in the shield case 3 in advance. There are very few unfilled areas, including around the sliding surface of the magnetic core 1 and around the protrusion 3b for preventing removal, and the amount of filled resin 8 is just right. Does not occur. Furthermore, since the filling resin 8 is injected without the core support assembly 4, it is very simple, and the filling resin 8 does not adhere to the conductive terminals 7.

Other embodiments of the invention are illustrated in FIGS. 10A, 10B, and 11;
In the embodiment of FIG. 10B, the shield case 3
There is a convex part on the side of the head corresponding to the opening 3a.
B' is provided with its lid partially cut out using a press. A space is provided in this convex portion B' to accommodate the head of the magnetic core 1 so that the head of the magnetic core 1 is exposed during final finishing of the sliding surface. In the embodiment shown in FIG. 11, there is an opening 3 on the side surface of the head of the shield case 3, as in the conventional embodiment.
A is provided, and a lid C is fitted therein, but the lid C also protrudes to take up space for the head of the magnetic core 1. The filling and fixing steps of the manufacturing method of these embodiments are exactly the same as those of the previous embodiments according to the present invention, and the same effects can be obtained. However, in the subsequent grinding process up to the grinding surface D, in these embodiments, the protrusion B' or the lid C can be easily removed, making the grinding process easier.
Incidentally, the same effect can be obtained even if a head body consisting of a core and a coil is used instead of the core support assembly 4.

As explained above, in the method for manufacturing a magnetic head according to the present invention, in the step of filling and fixing the head element into the shield case with resin, first, a certain amount of filling resin is poured with the opening of the shield case closed. The head element is then press-fitted, and after the filling resin has hardened, the opening facing the magnetic core is opened in the shield case, so there are very few unfilled areas. , the head element is securely fixed, preventing damage to the magnetic tape due to poor fixation and poor contact between the magnetic tape and the magnetic core, and the filling resin is used in an appropriate amount, eliminating waste, and making the filling resin injection process easier. This is very simple and has the excellent effect of completely preventing the conductive terminal from being insulated due to adhesion of the filled resin.

[Brief explanation of drawings]

1 to 5 show examples using conventional manufacturing methods. FIG. 1 is a perspective view showing the entire magnetic head, FIG. 2 is a perspective view showing the structure of the magnetic head, and FIG. 3 is a perspective view showing the structure of the magnetic head. A sectional view showing the filling process of the core support assembly into the shield case with filling resin,
Fig. 4 is a sectional view showing the filling state when the viscosity of the filled resin is low, Fig. 5 is a sectional view showing the filling state when the viscosity of the filling resin is high, and Figs. 6 to 11 are according to the present invention. 6 shows a perspective view of the shield case, FIG. 7 shows a sectional view of the shield case, and FIG. 8 shows the process of injecting the filling resin into the shield case and press-fitting the core support assembly. A cross-sectional view, FIG. 9 is a cross-sectional view showing the filling state of the core support assembly with filled resin, and FIG. 10A.
10B is a sectional view of a shield case according to another embodiment of the present invention, FIG. 10B is a perspective view thereof, and FIG. 11 is a perspective view of a shield case according to another embodiment of the present invention. 1...magnetic core, 1'...1 channel core,
1″...2 channel core, 2...shield plate,
3... Shield case, 3a... Opening, 3b...
...Protrusion for preventing falling off, 4...Core support assembly,
4', 4''...Support, 4a...Groove, 5...Built-in spring, 6...Bobbin coil, 7...Conductive terminal, 8...Filled resin, A...Filled resin injection direction, B, B' ... Convex portion, C... Lid, D... Grinding surface.

Claims (1)

[Scope of Claims] 1. A magnetic head manufacturing method in which a magnetic head is manufactured by fitting a head element into a shield case and filling and fixing it with resin, in which a convex portion is formed on the magnetic tape sliding surface of the shield case. A resin is injected into the shield case, and then the head element is fitted into the shield case, and after the filled resin has hardened, the protrusion is removed to form an opening through which the magnetic core of the head element faces. A method of manufacturing a magnetic head. 2. In a magnetic head manufacturing method in which a magnetic head is manufactured by fitting a head element into a shield case and filling and fixing it with resin, a cover is provided over the opening formed on the magnetic tape sliding surface of the shield case and the head is filled. A resin is injected into the shield case, then the head element is fitted into the shield case, and after the filled resin has hardened, the lid is removed so that the magnetic core of the head element faces the opening. A method for manufacturing a magnetic head.