JPS61120309A - Magnetic head - Google Patents

Abstract

PURPOSE:To obtain a magnetic head excellent in mass-producibility, improved in wear resistance and reproduction efficiency and small in adjacent crosstalk by forming an auxiliary substrate made of composite material of nonmagnetic body and magnetic body to specified structure. CONSTITUTION:In a magnetic head in which a platelike or stratiform magnetic body 14 made by vapor deposition or spattering is held between auxiliary substrates made of composite material of nonmagnetic body 12 and magnetic body 11, the boundary face of the nonmagnetic body and magnetic body 12, 11 is made to have inclination 17 in the direction of thickness of the head, and the magnetic body 11 is made to increase in the direction of depth looked from the front of the sliding face of the tape. The sliding face of the tape is finished to a curved face not to expose the magnetic body 11 near a magnetic gap 16 and to expose the magnetic body 11 in the periphery of the tape sliding face. By this way, the manufacture of a composite head held between reinforcing substrates excellent in wear resistance becomes easy. Further, the efficiency is improved and adjacent crosstalk can be made small at the time of reproducing azimuth record.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a magnetic head used in a magnetic recording/reproducing device, in particular, a magnetic head that uses a magnetic thin strip or a magnetic thin film by means such as vapor deposition or sputtering in the magnetic core, and contains a magnetic material. Concerning composite heads with reinforcements.

Conventional Structures and Problems Metallic magnetic materials are being put into practical use as magnetic head materials for high-density recording and for high-coercivity tapes by taking advantage of the characteristics of high-magnetic-flux-density materials. However, as a magnetic head material,
It has the disadvantage of significantly poorer wear resistance than the currently mainstream ferrite materials. Therefore, when a magnetic metal material is used in a magnetic head, a structure must be adopted in which the magnetic material is sandwiched from both sides using a reinforcing material with excellent wear resistance. In this case, the thickness of the magnetic material usually corresponds to the track width for recording and reproduction. For video heads currently used in household ``%'' THs, a magnetic head with a track width of about 30 fim is desired, and there is a trend toward even narrower trunks. The problem at this time is that the magnetic core of the magnetic head is a single thin piece, resulting in a decrease in the efficiency of the magnetic head. For example, the reproducing efficiency of a magnetic head is generally expressed by the magnetic flux passing through the windings, the leakage flux around the core, and the magnetic flux passing through the windings.When the magnetic core is made into thin pieces, the leakage flux around the core becomes impossible to ignore. In terms of the magnetic circuit, efficiency also tended to decrease due to an increase in magnetic resistance due to a decrease in the cross-sectional area of the magnetic path passing through the windings.

Therefore, the composition of a composite reinforcing material of a non-magnetic substrate with good wear resistance and a magnetic substrate to improve efficiency was investigated. For example, as shown in FIG. 1, a magnetic film 1 is sandwiched between composite reinforcing substrates consisting of a non-magnetic part 2 and a magnetic part 3. In Figure 1, configurations c are more efficient than a because the magnetic part of the reinforcing substrate is closer to the magnetic gap, and configuration b is more efficient in the azimuth recording system like home VTRs. In this case, the magnetic portion of the reinforcing substrate becomes a pseudo gap, which causes crosstalk between adjacent channels, which is inconvenient. Therefore, a video head having the configuration C is desired. However, the configuration C had a complicated structure and had a drawback in mass production.

OBJECTS OF THE INVENTION An object of the present invention is to provide a magnetic head having a structure in which a magnetic layer is used as a core material, and the core material is held between reinforcing substrates that are a composite of nonmagnetic and magnetic substrates.

Structure of the Invention The present invention is a magnetic head having a structure in which a plate-like or layered magnetic material formed by vapor deposition or sputtering is sandwiched between an auxiliary substrate made of a composite material of a non-magnetic material and a magnetic material, and the auxiliary substrate has the following structure.

1. The tape sliding surface is the front, a non-magnetic material is arranged on the front and a magnetic material is arranged on the rear, 2. The boundary surface is inclined in the depth direction, 3. Both the non-magnetic part and the magnetic part The configuration is based on tape sliding,
This is a magnetic head whose tape sliding surface is a curved surface.

DESCRIPTION OF EMBODIMENTS A detailed embodiment will be described below regarding a video head used in a home VTR.

FIG. 2 shows an embodiment of the present invention. First, a flat ferrite core 11 shown in a is prepared. A groove 12 with a trapezoidal cross section, indicated by b, is machined on this using a diamond cutter.
Fill the groove with non-magnetic material. A low melting point glass was used for this, and the groove was filled with glass. Next, this ferrite core was ground thin to a thickness 13 such that the ferrite core was completely separated by the non-magnetic portion 12, resulting in the configuration shown in C. The magnetic material 14 is a ribbon-shaped amorphous material (Fθ-3o-si-B) produced by an ultra-quenching method, which is made into a ribbon shape and finished to a thickness of 30 mm by double-sided lapping, as shown in d. A reinforcing substrate of C was bonded to the magnetic core 14 in a structure that held the magnetic body 14 between them.

For this bonding, an epoxy adhesive was impregnated in a very thin layer (with a thickness of several microns or less) and bonded. Next, the core was divided into two at approximately the center of d, and the resulting surface was used as a magnetic gap forming surface and polished to be smooth, and a groove 15 for the winding was formed (see θ). On this magnetic gear forming surface, 510216 was formed as a gap spacer by RF sputtering in an amount corresponding to the desired gap length, and the gap forming surface was bonded again to finish the front surface of the head into a spherical surface, completing the head chip f.

This completed chip is shown in FIG. 3, and has a configuration in which a desired magnetic material 14 is sandwiched between a non-magnetic material 12 and a magnetic material 11, and the magnetic material 11 is close to the magnetic gap, and the edge 17 on the front surface is curved. By having an inclination with the magnetic gap 16, the structure is such that crosstalk from adjacent tracks is suppressed during azimuth recording and reproduction. In addition, the magnetic part ferrite 11 of the reinforcing material has significantly improved wear resistance compared to metal magnetic materials, and a video head with high reliability in terms of life can be obtained. All of these results are due to the fact that a reinforcing material having a trapezoidal groove-shaped non-magnetic portion 12 as shown in FIG. 2C was created.

The trapezoidal groove shape and its relative arrangement with respect to the gap depth will be explained in detail in FIG. It has a trapezoidal groove shape, and the position of the slope is important.When the front surface of the head is machined into a cylindrical or spherical surface with a radius R, the slope angle is from the gap depth D to the rear position H when viewed from the tape sliding surface. It is desirable that the reinforcing material magnetic part 11 be arranged at 2o, and that the inclined part be arranged within the position of the intersection of the front surface R21 and the chip length 22. That is, the reinforcing material magnetic portion 11 is held between the magnetic body 14, which is the main magnetic core, with an inclined surface within the curved surface portion of the front surface of the head.

In this way, by simply creating a magnetic reinforcing material with a non-magnetic block on the base, mass production can be easily achieved by arranging the boundary surface between the non-magnetic and magnetic blocks of the reinforcing material within the tape sliding curved surface of the head. A video head with superior wear resistance, improved efficiency, and low adjacent crosstalk has been created.

In the example, explanation was given using a ribbon-shaped amorphous magnetic material, but it is clear that it is also possible to use a sendust alloy ribbon, and it is not limited to a plate-shaped magnetic material. Alternatively, the present invention can be easily applied to a case where the magnetic layer is formed by sputtering.

Furthermore, as shown in FIGS. 5a, b, and c, the slope of the interface between the nonmagnetic material and the magnetic material may be opposite to that of this embodiment.

Effects of the Invention According to the present invention, it has become easy to manufacture a composite head (particularly one using a metal magnetic thin film) which is sandwiched between reinforcing substrates having excellent wear resistance. Furthermore, it has become possible to improve efficiency and reduce adjacent crosstalk during azimuth recording and reproduction.

[Brief explanation of the drawing]

Fig. 1 is a front view and a plan view of various composite heads, Fig. 2 is a conceptual diagram of the manufacturing process according to the present invention, Fig. 3 is a front view, plan view, and side view of a head chip according to the present invention, and Fig. 4 is a FIG. 5, which is a diagram for explaining in detail the essential parts of the present invention, is a front view, a plan view, and a side view of the head chip according to the present invention. 11...Magnetic material (magnetic part ferrite), 12.
...j...Non-magnetic part, 13...Thickness, 14...
...magnetic material, 16...magnetic gap, 17.
...Edge. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] In a magnetic head having a configuration in which a plate-like or layered magnetic material formed by vapor deposition or sputtering is sandwiched between an auxiliary substrate made of a composite material of a non-magnetic material and a magnetic material, the interface between the non-magnetic material and the magnetic material of the front auxiliary substrate is The structure has an inclination in the thickness direction, and the magnetic material increases in the depth direction when viewed from the front of the tape sliding surface.The magnetic material is not exposed near the magnetic gap, and the magnetic material is concentrated around the tape sliding surface. A magnetic head characterized by a tape sliding surface that is curved so that it is exposed.