JPH04129005A - Magnetic head - Google Patents

Abstract

PURPOSE:To obtain a magnetic head which is produced with a good yield and has a high reproducing efficiency by providing V-shaped grooves and another groove on a magnetic gap forming face and filling V-shaped grooves higher than the winding groove with a magnetic allow thin film having a high saturation magnetic flux density and filling grooves lower than the winding groove with a magnetic alloy thin film of high permeability. CONSTITUTION:A V-shaped groove 5 is provided in a position of track width higher than a winding groove 6 on the forming face for a magnetic gap 4 of a core half body 1 constituting a magnetic head and is filled up with a magnetic alloy thin film 2 having a high saturation magnetic flux density, and one or plural grooves 5 are provided in positions lower than the winding groove 6 in the direction rectangular to the groove 6 and are filled up with a magnetic alloy thin film 3 of high permeability. As the result, the track width is independent of the extent of grinding of the forming face for the magnetic gap because being determined by the size of the V-shaped groove 5 provided in the position higher than the winding groove 6, and the permeability of the whole of a magnetic head circuit of the magnetic head is raised. Thus, a video head having a high precision of track width and a high recording/ reproducing efficiency is obtained with a good yield.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic head, and particularly to a magnetic head suitable as a video head for a VTR.

[Summary of the invention]

A magnetic head that can record on high coercive force media by forming a high saturation magnetic flux density magnetic alloy thin film on the magnetic gap forming surface of a conventional magnetic material such as single crystal ferrite, polishes the apex portion between the V-shaped grooves. However, the flat part is the track width.

When high precision is required, such as in high recording density video heads,
-Production yield is low. Furthermore, since the magnetic material does not have high magnetic permeability and the magnetic alloy has low magnetic permeability, the reproduction efficiency of the head is low.

In order to solve the above problem, the present invention provides a 7-shaped groove and a groove on the magnetic gap forming surface of the magnetic core half.

The 7-shaped groove above the winding groove is filled with a magnetic alloy thin film having a high saturation magnetic flux density, and the groove below the winding groove is filled with a high permeability magnetic alloy thin film.

[Conventional technology]

Conventionally, composite magnetic material magnetic heads have been known in which a magnetic alloy thin film with high saturation magnetic flux density is formed on the magnetic gap forming surface of a magnetic material such as single crystal ferrite, making it possible to sufficiently record even high coercive force media such as metal data. It is being

In this magnetic head, in order to prevent the magnetic gap and the surface on which the high saturation magnetic flux density magnetic alloy thin film is formed from becoming parallel and a pseudo gap to occur, a 7-shaped groove is provided on the magnetic gap formation surface. A magnetic alloy thin film is formed and the apex of the figure-7 groove is polished. This conventional magnetic herad core is shown in FIG. Here, 1 is an oxide magnetic material such as single crystal ferrite, 2 is a high saturation magnetic flux density magnetic material, 4 is a magnetic gap, 6 is a winding groove, and 7 is a track width control groove. Incidentally, in this magnetic head, the track width is manufactured by forming a magnetic alloy thin film and then polishing the apex of the 7-shaped groove to make it flat.

The track width is determined by the amount of polishing. On the other hand, the track width accuracy of recent high-density video heads is required to be about ±1 μm, and the above track width determination method has a low production yield.Furthermore, the entire magnetic circuit is usually made of single-crystal ferrite, etc. Since it is made of oxide magnetic material, a magnetic material with particularly high magnetic permeability cannot be expected, and magnetic alloy thin films with high saturation magnetic flux density usually have low magnetic permeability.For this reason, the above-mentioned conventional magnetic head has a low recording capacity. Although it is expensive, the regeneration efficiency is low.

[Problem to be solved by the invention]

The above-mentioned conventional technology has the drawbacks of poor production retention and low regeneration efficiency, as described above. The purpose of the present invention is to prevent the track width accuracy from being affected by the amount of polishing of the magnetic alloy thin film, and to increase the permeability of the magnetic material on the magnetic gap forming surface, thereby achieving high production yield and improving regeneration efficiency. The objective is to provide a magnetic head with high quality.

[Means to solve the problem]

In order to achieve the above-mentioned object, the present invention provides a figure-7 groove at a position corresponding to the track width above the winding groove on the magnetic gap forming surface of the core half that constitutes the magnetic head. Filled with alloy thin film.

In addition, one or more grooves are provided below the winding groove in a direction perpendicular to the above-mentioned grooves, and these grooves are filled with a magnetic alloy thin film having high magnetic permeability.

[Effect]

As a result, unlike the conventional magnetic head described above, the track width is determined by polishing the apex of the figure 7 shape, and instead of determining the desired track width, the size of the figure 7 groove provided above the first winding groove is determined. Since it is determined by the amount of polishing of the magnetic gap forming surface, it is not affected by the amount of polishing of the magnetic gap forming surface.

Furthermore, the magnetic permeability of the entire magnetic path of the magnetic head is increased.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. In this embodiment, the groove provided below the winding groove is in the shape of a 7-shape, but it does not have to be in a 7-shape. The diagram shows the diagonal I of the magnetic rad core! In the figure, 1 is an oxide magnetic material such as single crystal ferrite, 2
3 is a high saturation magnetic flux density magnetic alloy thin film, 3 is a high magnetic permeability magnetic alloy thin film, 4 is a magnetic gap, 5 is a groove provided below the 7-shaped groove and the winding groove provided on the magnetic gap forming surface, and 6 is a groove provided below the winding groove. The winding groove 7 is a track width control groove. This magnetic core block is constructed as follows. First, a winding groove is formed on the oxide magnetic material using a dicer or the like as in the conventional technique. Next, a fil or a plurality of grooves are formed on the magnetic gap forming surface using a dicer or the like, and at least the upper part of the groove is formed above the winding groove. That is, the 7-shaped groove in the gap depth direction provided between the 9-winding groove and the tape sliding surface is made larger than the final desired track width.

The spacing between the 7-shaped grooves provided at this time is determined in consideration of the size of the track width control groove, which will be described later. A magnetic alloy thin film is formed on this by sputtering, but when filling the high saturation magnetic flux density magnetic alloy into the 7-shaped groove above the 2nd winding groove, the area below the 2nd winding groove is masked.

Conversely, when filling a groove formed below the winding groove, that is, between the winding groove and the surface opposite to the tape sliding surface, with a high permeability magnetic alloy thin film, the area above the winding groove is masked. In addition,
The groove provided at the lower part of the winding groove differs in direction by 90' from the 7-shaped groove provided at the upper part. After this, the surface where the gap is formed is polished so that at least 10 pm of the magnetic alloy thin film remains and the surface is flat.

Furthermore, a track width control groove is provided with a dicer so that the magnetic alloy thin film in the 7-shaped portion provided above the winding groove on the magnetic gap surface has the track width. Therefore, since the track width is determined only by the accuracy of the dicer, it can be formed with an accuracy of 1 μm or less.

After this, in the same way as in the conventional magnetic head manufacturing process, a non-magnetic thin film is placed on the magnetic gap forming surface, heated in an electric furnace to form a magnetic gap, and the track width control grooves are filled with low-melting glass. Cut it to obtain a magnetic chip. By fixing this magnetic chip in a predetermined position with an epoxy adhesive or the like and applying nine windings, a desired magnetic head can be obtained with a high yield.

〔Effect of the invention〕

According to the present invention, a video head with good track width accuracy and good recording and reproducing efficiency can be obtained with a high yield. Furthermore, by using this video head, it is possible to increase the recording density, so it is possible to realize a VTR that is small, lightweight, and has good performance.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a magnetic head core showing an embodiment of the present invention, and FIG. 2 is a perspective view of a conventional magnetic head core. 1: Oxide magnetic material such as single crystal ferrite, 2: High saturation magnetic flux density magnetic material, 3: High permeability magnetic alloy thin film, 4: Magnetic gap, 5: Seven-shaped groove and groove provided on the magnetic gap forming surface , 6: Winding groove, 7: Track width control groove.

Claims (1)

[Claims] 1. In a magnetic head constructed by butting together two magnetic core halves each having a winding groove on at least one side, the gap forming surface of each magnetic core has a gap between the tape sliding surface and the winding groove. A V-shaped groove is formed in the depth direction, a high saturation magnetic flux density magnetic alloy thin film is embedded in the groove, and
A groove is formed between the winding groove and the surface opposite to the tape sliding surface in a direction perpendicular to the direction of the V-shaped groove,
A magnetic head characterized in that a high permeability magnetic alloy thin film is embedded in the groove.