JPS6352317A - Magnetic head - Google Patents

Abstract

PURPOSE:To obtain a magnetic head having a narrow track, a high mechanical strength, and a low inductance by using a taper magnetic core. CONSTITUTION:A magnetic core 1 having a track face in the front end which is tapered by continuously and gradually reducing the thickness of a thin piece is tightly held between two nonmagnetic bodies 11 and 12 on both sides, and the track face of the magnetic core 1 is faced in a floating face or slide faces 13 and 14 formed on nonmagnetic bodies. Thus, the core has a narrow track and is structurally stout. Since the sectional area of a magnetic circuit in a gap butting part is considerably smaller than that in the other part, for example, the other gap part, the inductance of the magnetic circuit is sufficiently reduced. Further, an ideal floating face flatness is obtained, and therefore, a head whose extent of floating is small is realized with a high reliability.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic recording/reproducing device, and particularly to a narrow track magnetic head for a magnetic disk device having excellent mechanical durability.

[Prior Art] Conventionally, many magnetic heads of this type have been used, the so-called Winchester head, in which a magnetic circuit part and a structure having a floating function are integrally formed by processing a ferrite sintered body. It is being said. This head has a total of three surfaces facing the recording medium surface: two air lubricating surfaces serving as flying surfaces and a track surface located approximately in the center of the two. However, in order to improve recording density, it is necessary to reduce the track width to increase the track density, reduce the clearance between the magnetic head and the medium, that is, the flying height, to increase the bit density, and increase the speed of write and read signals. must be done.

[Problems to be Solved by the Invention] Considering the conventional Winchester head in light of these points, the central track portion of the three facing surfaces is thin and fragile, so it has poor mechanical durability.

Dimensional accuracy cannot be fully satisfied, and it is almost impossible to maintain the same flatness of the three opposing surfaces required to stably achieve a low flying height, for example, at O, OS microns or less. Furthermore, since the magnetic circuit also serves as a mechanical structure, it has physically large dimensions, and therefore the inductance of the coil is large. As a result, the co-propagating frequency determined by the inductance and capacitance of the coil becomes small, making it unsuitable for high-speed data transfer using high frequencies, for example, 5 old Z or higher.

An object of the present invention is to provide a magnetic head that can obtain low inductance, a mechanically strong track structure, and ideal air bearing surface flatness.

[Means for Solving the Problems] The present invention includes a magnetic core having a track surface at its tapered tip by continuously and gradually decreasing the wall thickness of a thin piece, which is tightly sandwiched from both sides by two non-magnetic materials. This magnetic head is characterized in that the track surface of the magnetic core is exposed to an air bearing surface or a surrounding surface formed of a non-magnetic material.

[Embodiment] Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of an embodiment of the present invention. magnetic core 1
is made of flaky ferrite and has a winding part 2 and a main body 3, and the winding part 2 and the main body 3 are welded and fixed at two places by bonding glass 4. A read/write cap 5 is formed on one of them to form a magnetic circuit.

The magnetic core 1 is formed into a tapered shape by continuously and gradually reducing the thickness of flaky ferrite, and the thickness tl of the surface facing the recording medium, that is, the track surface 6, is significantly smaller than the thickness t2 of the surface 7 on the opposite side. It has a tabular structure. In this example, the thickness tl of the track surface 6 is set to 10 microns, and the thickness t2 of the opposite surface 7 is set to 120 microns. In this way, a core with a narrow track and at the same time structurally strong can be realized. Since the cross-sectional area 8 of the magnetic circuit at the gap abutting portion is overwhelmingly smaller than the cross-sectional area 9 at other portions, for example, another gap portion, the inductance of the magnetic circuit can be made sufficiently small.

FIG. 2 shows an embodiment of the slider assembly of the present invention. The slider assembly 10 consists of a tapered magnetic core 1, a first sintered non-magnetic body 11, and a second sintered non-magnetic body 12. The slider assembly 10 has two air bearing surfaces (or) 8 moving surfaces) 13.
and 14 are formed, and the track surface 6 of the tapered magnetic core is located approximately at the center of one of the air bearing surfaces 14. The tapered magnetic core 1 consists of two sintered non-magnetic materials 11 and 12.
It is tightly sandwiched from both sides by the fused glass and is tightly fixed by the welded glass. Therefore, the adhesive glass layer has a thickness of 1 micron or less, and virtually no adhesive glass layer is exposed on the air bearing surface 14. Gap glass 4 of magnetic core 1 during welding
It is necessary to use glass with a melting point of about 550'C so as not to adversely affect the magnetic core, but this glass is softer and has inferior mechanical strength than the tapered magnetic core and the non-magnetic material 11.12. However, in the present invention, since this glass layer is not exposed on the air bearing surface, there is no deterioration in durability due to glass.

The two air bearing surfaces 1.3.14 are ground so that they form the same surface. Since the track surface 6 is included in one of the air bearing surfaces 14, the track surface 6 is always contained within the same plane as the air bearing surface. With such a configuration, it is easy to form the two air bearing surfaces with a flatness of within 0.05 microns, and therefore a head with a flying height of 0.2 microns or less can be realized with high reliability.

[Effects of the Invention] As described above, the present invention uses a tapered magnetic core to realize a magnetic head with a narrow track, strong mechanical strength, and low inductance. Furthermore, by holding the tapered magnetic core in a sandwich-like manner with a non-magnetic material to realize a slider assembly having two medium facing surfaces, ideal air bearing surface flatness can be obtained.
It is possible to realize a flying height head with high reliability. Further, in the slider assembly of the present invention, the track surface of the magnetic core is not included in the longitudinal edge of the slider air bearing surface, so there is no fear of damage due to chipping during use of the head.

Further, since the air bearing surface is formed of a non-uniform material with the track surface, and the welding material is virtually not exposed on the air bearing surface, the mechanical durability of the slider is extremely excellent.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a magnetic core according to an embodiment of the present invention, and FIG. 2 is a perspective view showing a magnetic core assembly according to the present invention.

Claims (1)

[Claims] (1) A magnetic core with a track surface at the tip, which is formed into a tapered shape by continuously decreasing the wall thickness of the thin piece, is attached from both sides.
1. A magnetic head characterized in that the magnetic core is tightly sandwiched between two non-magnetic materials, and the track surface of the magnetic core faces an air bearing surface or a sliding surface formed of the non-magnetic material.