JPS6341127B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic head, and an object of the present invention is to make it possible to easily obtain a magnetic head with excellent performance and an ultra-narrow track width.

Conventionally, magnetic heads, such as video heads for home VCRs, which require narrow track widths of several tens of micrometers, have been designed to ensure wear resistance, increase core efficiency, and reduce the effects of crosstalk from adjacent tracks. Therefore, as shown in Figure 1 a and b, the thickness is made of various Mn-Zn ferrites (single crystal, hot pressed, oriented, etc.) that have high permeability in the megahertz band.
The notch 3 is made so as to leave a predetermined track width TW only in the vicinity of the gap 2 of the cores 1 and 1', which are 100 to several hundred μm.
It is common to have a structure in which the notch is filled with a non-magnetic material 3' such as glass. However, a head with such a structure cannot be used for ultra-narrow track widths of about 10 μm or less because the thickness of the track width forming portions 4, 4' near the notch is extremely thin. Since the magnetic resistance becomes high, the proportion of leakage magnetic flux from the side surfaces of the track becomes relatively high, which tends to cause a decrease in core efficiency and magnetic saturation in this part. In addition, when machining the head, breakage is likely to occur when machining the notch.
Furthermore, even in the case of etching or laser processing, it is extremely difficult to simultaneously achieve a predetermined track width accuracy.

From this point of view, as shown in Figure 2a, a head with a structure in which a metal magnetic material such as permalloy or sendust having a high saturation magnetic flux density is formed by vapor deposition or sputtering to form a track width equal to the film thickness is also known. It is being The head of this structure is made by forming a magnetic metal layer 6 such as Sendust on a non-magnetic substrate 5 such as glass in the shape of a half core by sputtering or the like, as shown in Fig. 2c. A pair of cores are abutted and fixed on a non-magnetic substrate 7 such as glass to form a gap, thereby completing a head having the structure as shown in FIG. 2a. In this structure, the track width is basically the thickness of the magnetic material, so it is possible to form an ultra-narrow track width of several μm. On the other hand, since the magnetic circuit is composed of only a magnetic thin film, the magnetic resistance is low. becomes high and tends to cause a decrease in core efficiency. Also the second
As seen in Figures b and c, the structure also has the disadvantage that it is difficult to find a way to efficiently form the gap.

The present invention provides a structure with excellent performance that solves the problems that arise when narrowing the track of the conventional head. Embodiments of the present invention will be described below with reference to the drawings.

3a, b and c each show a first embodiment of a magnetic head according to the invention. In the figure, reference numerals 16 and 16' designate metal magnetic films that form track width portions and have high saturation magnetic flux density, and are composed of sputtered films of sendust or amorphous magnetic alloy, or vapor-deposited films of high hardness permalloy. Further, a non-magnetic gap 12 is formed at the abutting portion of the pair of left and right magnetic films. 1
Reference numerals 1 and 11' denote core main parts that are magnetically continuous with the metal magnetic films 16 and 16', and are made of a bulk material having high magnetic permeability such as Mn--Zn ferrite or sendust. Numerals 13 and 13' are filled with non-magnetic material such as glass, brazing material, resin, etc., which are provided to support or protect the thin film track width portion and to ensure wear resistance on the front surface of the head. 10 is a winding window. In addition, in FIG. 3b, the non-magnetic material filling portions 13, 13' are removed in order to clarify the relationship between the metal magnetic films 16, 16' and the bulk core main body portions 11, 11' in the vicinity of the gap 12. This is a diagram. FIG. 3c is a view of the head viewed from the tape sliding surface. In the present invention, the metal magnetic film 16,
The thickness of 16' is extremely thin and equal to the predetermined track width (several μm). For this reason, the magnetic resistance is high and the proportion of magnetic flux leaking from the sides increases, which tends to reduce core efficiency and cause magnetic saturation in the magnetic film. The spread dimension L must be made as small as possible, and is preferably about 10 times or less the track widths T and W. In this way, the thin film track component is kept to the minimum necessary, and in terms of the magnetic circuit, the core main body 1 is made of a bulk material with a wide core width and low magnetic resistance.
1 and 11'. Further, in order to ensure complete magnetic continuity between the metal magnetic material portion and the bulk portion, the structure is such that the area of the cross section parallel to the gap forming surface gradually decreases at the tip of the bulk portion.

FIG. 4 shows a second embodiment of the magnetic head according to the present invention, in which left and right magnetic films 16 and 16' facing each other with a gap 12 in between are arranged on the same side with respect to the width of the track.

5a, b, and c similarly show a third embodiment of the present invention, in which the magnetic film 16 only near the gap pole,
16' is perpendicular to the gap forming surface, and the joint surfaces with the core main body parts 11, 11' form a predetermined angle θ with the gap forming surface, so that when the inclined part touches the adjacent track part, a predetermined azimuth loss is achieved. This is intended to reduce crosstalk. In the case where it is not necessary to prevent the regeneration effect at the notch portion of the bulk core as described above, as shown in the fourth embodiment of the present invention shown in FIG. The bonding surface with the membranes 16, 16' may be configured to be parallel to the gap forming surface.

FIG. 7 also shows a fifth embodiment of the present invention.
In this case, the track width TW is the metal magnetic layer 17.
It is constituted by a laminated body in which layers 18 of non-magnetic insulating material such as SiO or SiO ₂ are alternately arranged. Therefore, by reducing the thickness of the metal magnetic layer to a thickness that does not cause loss due to the skin effect, and increasing the number of laminated layers to form a predetermined track width, the magnetic resistance in this area can be reduced to an ideal state. can do. In the drawings showing the embodiments, common elements are given the same symbols and repetitive explanations are avoided.

As described above, in the magnetic head according to the present invention, only the track width component near the gap is made of a magnetic thin film with a high saturation magnetic flux density, and the other parts are made of a magnetic material with a high magnetic permeability. It is a magnetic head with an ultra-narrow track width and excellent recording and reproducing characteristics.

[Brief explanation of the drawing]

1A and 1B are a top view and a perspective view of a conventional magnetic head, respectively, FIGS. 2A, B, and C are perspective views for explaining another conventional magnetic head, and FIGS. 3A, B, c is the first of the present invention, respectively.
FIG. 4 is a perspective view of a magnetic head according to a second embodiment of the present invention, a perspective view of essential parts of the magnetic head, and a top view of the same magnetic head. Figures 5a, b, and c are respectively a top view, a perspective view, and a perspective view of essential parts of a magnetic head according to a third embodiment of the present invention.
7 are top views of magnetic heads which are fourth and fifth embodiments of the present invention, respectively. 11, 11'...Core main body part, 12...Gap, 13, 13'...Nonmagnetic material filling part, 16,1
6'...Metal magnetic film.

Claims (1)

[Scope of Claims] 1. One ends of each of a pair of metal magnetic films having high saturation magnetic flux density face each other to form a gap, and the thickness of the metal magnetic film at the gap forming portion corresponds to the track width. A magnetic head characterized in that the other end side of the metal magnetic film is bonded to a core body made of a magnetic material having high magnetic permeability. 2. The magnetic head according to claim 1, wherein the bonding surface between the metal magnetic film and the core body is not parallel to the track direction. 3. The magnetic head according to claim 1 or 2, wherein the bonding area between the metal magnetic film and the core body is sufficiently larger than the area of the gap forming surface. 4. The magnetic head according to claim 1, wherein the surface of the core body closer to the gap is inclined with respect to the track direction. 5. The magnetic head according to claim 1, wherein the metal magnetic film is composed of a laminate of metal magnetic materials with a non-magnetic material sandwiched therebetween. 6. Claim 1, characterized in that ferrite is used as the material of the core body, and at least one selected from the group consisting of permalloy, sendust, and amorphous magnetic alloy is used as the material of the metal magnetic film. Magnetic head as described in section.