JPS59140619A - Core for magnetic head - Google Patents

Abstract

PURPOSE:To improve reproducibility and mass-productivity by coating an alloy thin sheet core provided with a magnetic gap and a closed magnetic path with a nonmagnetic metallic plating film. CONSTITUTION:15 denotes a thin sheet core of a ''Sendust'' alloy composed of 6.2wt% Al, 9.6wt% Si, and 84.2wt% Fe. The core 15 is beforehand deposited with an SiO2 film 6'' of about 0.2-0.3mum by a sputtering method, etc. on the magnetic gap 6' between the upper corner parts 4', 5' which are brazed to face each other for the need of facilitating the plating operation by adhering securely core blocks 2' and 3' in the case of butting said core blocks. An Ni-P alloy film 16 as a nonmagnetic metallic plating film is formed by immersing the core 15 in an electroless nickel plating soln. to be subjected to hypophosphite reduction to coat the plating film over the entire surface thereof then polishing the end face covering the gap 6' until the gap 6' is exposed. Since the alloy core is coated and reinforced by the nonmagnetic metallic plating film in the above- mentioned way, the coating is easily accomplished without requiring another reinforcing member and without requiring the stage for sandwiching and assembling the core.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a core used in a magnetic head based on magnetic recording principles, and is a technology for completely improving the material and structure of the core.

[Background technology]

Conventionally, the magnetic head that transmits and receives all video signals has low coercive force and crystal saturation magnetic flux density? The entire ferromagnetic core is used. As this ferromagnetic core, Mn-Zn system 7j
-5ite and σ) alloys such as Sendust alloy are mainly used, but electronic devices such as VTRs and computers that fully utilize magnetic heads are required to further increase the recording density than the total recording density. It is highly likely that alloy systems such as Sendust alloy that can obtain saturation magnetic flux density will be used in the future.

However, at present, the Sendust alloy core is lower than that of ferrite in terms of mechanical 'J IIe and wear resistance, so it has to have the structure described below, which makes it difficult to manufacture. However, there was a hope that there was little practicality.

In other words, the conventional alloy core, as shown in Figure 1,
Thin plate-shaped core blocks 2 and 3' with the entire notch l? The windows are butted together to form the entire window, and the opposing upper corners 4 and 5VC are completely formed with an extremely narrow gap 6, and all the coils of conductive wire are wound around the legs 7 and 8, which will become the window frame, and they are butted flat. Yoke part 11 which becomes a closed magnetic path by the base part 9.10
The entire magnetic gap is configured to allow all of the magnetic flux to leak into the air gap 6. Here, the thin plate alloy core 1
When using sendust alloy, which has all the compositions of the material f of 2, including Fe, Si, and At, the Vickers hardness is about 500 and it is brittle. It shall have a clamped structure as shown in the figure. Therefore, additional reinforcing material is required to be manufactured, and high-precision dimensional processing and assembly of the clamping holder requires skill, making it difficult to achieve reproducibility.

[Disclosure of the invention]

This invention is proposed to solve all the above-mentioned conventional problems, and improves the mechanical strength and wear resistance of a magnetic head that uses a mating plate-shaped core that is fully equipped with a magnetic gap and a closed magnetic path. The entire structure is characterized by being coated with a non-magnetic metal plating film as described later as a reinforcing material for total reinforcement. Therefore, as a result, this invention not only improves production efficiency and reduces costs, but also improves reproducibility because the clamping process does not require the structure to be completely exposed. Demonstrate all of the excellent strengths that can be promoted.

[BEST MODE FOR CARRYING OUT THE INVENTION] FIG. 3 is a perspective view of a core for a magnetic head showing an embodiment of the present invention, in which 15 has a composition of A6.2 and Si9.6.
, Fe 84.2 wt% Sendust alloy thin plate core, as shown in a perspective view of the single unit in FIG. 4, is basically the same as the conventional thin plate alloy core 12 shown in FIG. Identical parts are indicated by adding a ' symbol to the figure number. However, when the thin plate-like core 15 is fully butted with the core blocks 2' and 3', it is necessary to bond it extremely firmly and to make it easy to handle during the plating work, so the silver brazing is done in a solid layer.
Opposing upper corner 4'.

The magnetic gap 6' between 5' has a thickness of 0.2 to 0.3 μm.
The 8102-degree film 6' is deposited by a total sputtering method or the like. In order to manufacture the core blocks 2', 3"Th, as shown in FIG. After the whole plate is covered and the brazing is fixed as shown in FIG. 6, each of the thin plate cores 15, 15. Slice into...

Next, a thin plate core 15i is applied to an electroless nickel plating solution in which a hypophosphite ring is fully formed using 16Fi, an N1-P alloy film as a non-magnetic metal plating film which is the gist of the present invention.
After dipping and directly coating the entire surface, blood leakage completely covered the magnetic gap 6', that is, as shown in Figure 3, the magnetic tape, magnetic disk, etc. were in close proximity.

The entire sliding top surface 17 is polished until the magnetic gap 61 is exposed. Here, N1-P alloy coating 1
6 is mechanical! i! Since it is a reinforcing material to enhance wear resistance, the electroless nickel plating solution has a total of 8 to 1 and a total of 8 to 12.

In the above embodiments, the N1-P alloy plate film was used as the non-magnetic metal film, but in the present invention, other materials such as a hard chromium plating film may also be formed, and the same advantages can be obtained.

According to this invention, since the mechanical strength and abrasion resistance of the core are poor and the entire core is covered with a non-magnetic metal plating film for reinforcement, the reinforced hammering sound made of ceramic or glass can be separately and accurately made. It does not require any process of molding or assembling with a thin plate core, and can be easily processed by electroless plating or the like.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view of a magnetic head core that employs a conventional alloy core, FIG. 2 is an assembled perspective view of the core, and FIG. 3 is a complete view of a magnetic head according to an embodiment of the present invention. Fig. 4 is a plan view of the alloy-based thin plate core, Fig. 5 is a perspective view of the core for
This figure and FIG. 6 are schematic perspective views during the manufacturing process of the thin plate core. 61... Magnetic gap, 11'.- Closed magnetic path, 15 Alloy thin plate core, 16... Nonmagnetic metal plating film. Figure 3 Figure 4 Figure 5 Figure 6 Leap

Claims (1)

[Claims] Alloy thin plate core with magnetic gap and closed magnetic path?
A core for a magnetic pad, which is completely characterized by being coated with a non-magnetic metal plating film.