JPS62212907A - Production of magnetic head - Google Patents

Abstract

PURPOSE:To stably and securely adhere main cores and reinforcing cores by preliminarily forming glass films consisting of a glass material having the m.p. substantially lower than the softening part of glass parts to constitute part of the reinforcing cores to at least either of the main cores or the reinforcing cores. CONSTITUTION:Relatively low melting point glass films 9 of PbO-SiO2-K2O are formed to 0.3-0.4mum thickness on both faces of the main cores 3 formed of a 'Sendust(R)' material and the joint surfaces of the reinforcing cores 4, 4. The reinforcing cores consist of ferrite parts 5 and glass parts 6. The main cores 3 are formed by bonding 'Sendust(R)' core half bodies 2a, 2b by a joining material 7 such as silver solder. The formation of the glass films 9 can be executed by a sputtering or vacuum deposition method, etc. Plural pieces of the main cores preliminarily formed with the glass films 9 and the reinforcing cores in the above-mentioned manner are alternately disposed in the jig 10 and carbon plates 11 are interposed between the respective magnetic head units at said time. The similar carbon plates 11' are also disposed to the inside walls of the jig 10. Press welding force is then exerted to the blocks and a heat treatment is executed.

Description

[Detailed description of the invention] (a) Industrial application field The present invention is an 8mm VT using a metal tape with high coercive force.
This invention relates to a method of manufacturing a magnetic head used in R@.

101 Conventional technology In 8mm VTRs, which use metal tapes with high coercive force, Sendust alloy (Fe-A/-
As shown in FIGS. 4 and 5, such a magnetic head uses a metal head made of a Kanasu material with a high saturation magnetic flux density, such as 81 series), as shown in FIGS.
After bonding the sendust core halves (2a) and (2b) with a bonding material (71) such as silver solder through the wires 11, the main core (3), which has been thinned to the desired track width, is connected to the ferrite portion (5). It has a structure sandwiched from both sides with a reinforcing core (4) consisting of a glass part (6), and when manufacturing a magnetic head with such a sandwich structure, conventionally the main core (3) and the reinforcing core (3) are sandwiched together as shown in Fig. 6. Epoxy resin (81, etc.) was applied to the bonding surface with the core (4), and five cores were laminated and bonded together. There is a method in which a glass film is formed in advance, but this method is intended only for bonding half of the main core, and is different from the method described in the present application, which is intended for a three-layer magnetic head.

(c) Problems to be solved by the invention By the way, in the method using resin adhesion as described above, the work efficiency is extremely low because the resin is applied manually to each contact circle, and the resin applied only once is The resin often protrudes from the adhesive surface before it solidifies, and it takes a lot of man-hours to remove the protruding resin. Chips were sometimes damaged during VC work, making it extremely inefficient.

B) Means for Solving the Problems Therefore, in the present invention, a glass film made of a glass material having a melting point sufficiently lower than the softening point of the glass portion constituting a part of the reinforcing core is preliminarily attached to the main core and the reinforcing core. The main core and the reinforcing core are joined by heating and welding this glass film. At this time, a plurality of magnetic heads are sequentially overlapped and simultaneously welded and formed. Therefore, a carbon plate containing a fiber material is interposed between adjacent magnetic heads.

11 Function When the glass film is heated, melted, and solidified, it firmly joins the main core and the reinforcing core. Since the softening point of the glass portion constituting a part of the reinforcing core is sufficiently higher than the melting point of the glass film, it will not be affected by heating. Further, the carbon plate interposed between adjacent magnetic heads is effective in preventing adhesion of adjacent magnetic heads and in realizing uniform pressure when pressure is applied to the entire body from the end.

(f) Embodiment Figure 3 shows PbO-SiO on both sides of the main core (31) and the reinforcing core (41 (41) made of sendust material).
2-K2O-based relatively low melting point glass film (9)
The case where the film is coated with a thickness of m to 0.4 μm is shown.

Here, the reinforcing core is the ferrite part (5) as in the conventional case.
The main core (3) consists of the sendust core halves (2a) and (2b) with a bonding material such as silver solder (71
are connected by. The glass film (9) can be formed by a sputtering method, a vacuum evaporation method, or the like.The main core and reinforcing core on which the glass film (9) has been formed in advance are assembled into a cellar shell as shown in Figure #11. A plurality of pieces are arranged alternately in a manufactured jig al.

At that time, carbon plates all are interposed between each magnetic head unit. This carbon plate αB contains a fiber material and has elasticity. A similar carbon plate a]f is arranged on the inner wall of the jig aG. Figure 2 (A) is a plan view of the jig Ql with the core and carbon plate attached, and Figure 2 (B) is a front view.The right end of the jig α is equipped with a bolt A3. The tip of this bolt is attached to the holding plate a.
3, the core and carbon plate are in contact with the block made of the superimposed core and carbon plate, and the pressing force accompanying the tightening of the bolt a3 is applied to the block.

Incidentally, since the carbon plate a11 arranged between the magnetic head units has elasticity, it has the effect of applying uniform pressure to the entire surface of the reinforcing core (4) in contact with the carbon plate (Ill). Although the surface of (4) is not a uniform plane from a black point of view and has irregularities and warps, the carbon plate αJ having elasticity suitably follows and contacts that surface.This is because the above-mentioned With the structure set in the jig as shown above, the entire structure is heat-treated at 500.degree. C. for 10 minutes in a vacuum atmosphere or inert gas to melt the glass film (9) and perform bonding.

After that, the magnetic head unit is taken out by loosening the magnetic head unit 13, and each of the magnetic head units is attached to the RadPace, and the shaping process is performed, and winding is performed to complete the magnetic head. Membrane (9
) was formed on both the main core (3) and the reinforcing core (4), but it goes without saying that it may be formed on only one of them.

(G1) Effects of the Invention According to the present invention, the main core and the reinforcing core can be bonded more stably and firmly than conventional methods, and the reliability of the product is improved. There is no need for protruding adhesive and associated adhesive removal work.
Not only can bulk processing be achieved at once, but the number of bonding steps can be significantly reduced.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a jig for assembling a magnetic head embodying the present invention, and FIG. 2 is a view showing it in detail. Fifth
The figure shows a part of the method of the present invention. FIG. 4 is a perspective view of a magnetic head manufactured by the present invention, and FIG. 5 is an exploded perspective view thereof. FIG. 6 is a diagram for explaining a conventional example. (3)...Main core, (41-...Reinforcement core, (51-
...Ferrite part, (6)...Glass part, (9
)...Glass film, (lIl...Carbon plate

Claims (2)

[Claims] (1) In a method for manufacturing a magnetic head in which a main core made of sendust material having an operating gap is sandwiched and bonded with a reinforcing core made of a ferrite part and a glass part, the melting point is sufficiently lower than the softening point of the glass part. A glass film made of a glass material having a characteristic of A method for manufacturing a magnetic head, which comprises sequentially overlapping each magnetic head, pressing the whole together with a carbon plate containing a fiber material interposed at the boundary of each magnetic head, and heating the whole in this state to weld the glass film. (2) The method for manufacturing a magnetic head according to claim 1, wherein the glass film is a PbO-SiO_2-K_2O glass.