JPS61107515A - Thin film magnetic head - Google Patents

Abstract

PURPOSE:To decrease generation of 'negative edge' inherent to a thin film magnetic head by providing a means for relaxing a magnetic flux near the tip of a magnetic substance. CONSTITUTION:A projection 23 whose tip is opposed to a medium contact face side is formed to a face of the side of a base 11 near the tip of a lower magnetic substance 22, and the tip of the projection 23 is not flush with the face of the tip of the magnetic substance on a face opposed to the medium but placed slightly (nearly 1mum) at the inner side than the tip face. Further, an insulation member 24 made of alumina being the same material of a protecting layer 81 is formed to the tip projected by the said 1mum. The magnetic substance 22 having the projection 23 like this is obtained easily by the method of sequential lamination of the projection part and the magnetic pole part. Through the forming of the projection 23 above, for example in case of the signal reproduction, a part of the magnetic flux near the edge A of the lower magnetic substance 22 is absorbed to suppress the concentration of magnetic flux to the said edge thereby decreasing extremely the 'negative edge' in the reproduced waveform.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thin film magnetic head, and particularly to a new head structure for reducing the occurrence of "negative edges" in recording and reproducing waveforms.

[Conventional technology]

The thin film magnetic head is well known as one suitable for high-density recording, and as shown in the enlarged cross-sectional view of the main part in FIG.
Lower magnetic body 21 on top. Gap material layer 31. First interlayer insulating layer 41. Coil conductor 51. Second interlayer insulating layer 61. Upper magnetic body 71. It has a structure in which a protective layer 81 is laminated. However, in this head, the tip lengths of the bare lower magnetic body 21 and the upper magnetic body 61 that serve as magnetic poles for high-density recording and reproduction, that is, the magnetic pole length l, are small at several μm or less. There is a problem in that a so-called "negative edge", which is caused by the uneven edge A, is a noise signal that disturbs the recording/reproducing signal and is generated in the recording/reproducing waveform.

FIG. 5 shows an isolated reproduction waveform of a thin film magnetic head with such a "negative edge" NE. "Etsuji" is appearing.

[Problems to be Solved by the Invention] The purpose of the present invention is to provide a thin film magnetic head that reduces the occurrence of "negative edges" in view of the conventional situation as described above. This is an attempt to record.

[Means for solving problems]

In order to solve the above-mentioned problems, this invention focuses on the fact that the cause of the above-mentioned "negative edges" is the concentration of magnetic flux at the edges of the magnetic material, and provides means for relaxing the magnetic flux at the edges of the magnetic material. It is characterized by being provided near the tip of the.

As a magnetic flux moistening means, a protrusion with its tip facing the medium facing surface is formed on the surface opposite to the gap material layer in the vicinity of the tip of the magnetic material.

[Effect]

The protrusion provided near the tip of the magnetic material expands and miniaturizes the magnetic flux to the edge of the magnetic material during recording and reproduction, so it is possible to significantly reduce the occurrence of "negative edges" there. ′
[Embodiment] FIG. 1 is a sectional view of a main part showing an embodiment of the thin film magnetic head of the present invention, in which the substrate 11 near the tip of the lower magnetic body 22 is
As shown in the figure, a protrusion/portion 23 is formed on the side surface with the tip facing the medium contact surface side. The tip of the protrusion 23 is not flush with the tip of the magnetic material on the medium facing surface, but is positioned slightly (about 1 μm) inside of it. In addition,
An insulating material 24 made of the same material as the protective layer 81, such as alumina, is formed at the tip of the approximately 1 μm protrusion. The magnetic body 22 having such a protrusion 23 can be easily obtained by laminating the protrusion component portion and the magnetic pole component portion in stages. Note that, other than the presence of this protrusion 23, there is no difference from the conventional structure shown in FIG. 4 above.

Taking the signal reproducing operation as an example, the protrusion 23 absorbs a portion of the magnetic flux near the edge A of the lower magnetic body 22, thereby suppressing the concentration of magnetic flux on the edge.

In other words, the magnetic flux near the edge A of the magnetic body 22 is input to the magnetic body in a dispersed manner. Therefore, the "negative edge" in the reproduced waveform of that part is the second
As shown in the figure, it is very small, and its influence on the reproduced signal is slight, and the quality during reproduction is improved.

FIG. 3 shows a modification of the present invention, in which a protrusion 25 for relaxing magnetic flux is partially provided at the tip of the lower magnetic body 22, and the tip is flush with the tip of the magnetic body. It is formed. Note that the reference numeral 26 is an insulating material made of alumina or the like. In this head, the tip of the protrusion is flush with the tip of the magnetic material, so when the head is cut out from the substrate and processed, the effect of the protrusion is less likely to change due to variations in the amount of cutting of the gear knob depth. There is.

In addition, in each of the above embodiments, the protrusion (2
3, 25) was formed only for the lower magnetic body 22, but
Needless to say, it can also be formed on the upper magnetic body 61.
It is more effective if both are formed at the same time.

〔effect〕

As can be understood from the above description, the present invention provides a means for relaxing the magnetic flux concentrated at the edge of the lower magnetic material constituting at least one magnetic pole on the side surface opposite to the gap material layer near the tip of the magnetic material. This makes it possible to reduce the occurrence of "negative edges" that are characteristic of thin-film magnetic heads. Therefore, the present invention is useful for realizing high-quality, high-density recording and reproduction.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part showing an embodiment of the thin film magnetic head of the present invention, FIG. 2 is a diagram showing an isolated reproduction waveform by the head, FIG. 3 is a diagram showing a modification of the invention, and FIG. The figure is a cross-sectional view of main parts showing an example of the configuration of a conventional thin-film magnetic head.
The figure shows an isolated reproduction waveform by the head. 11: Substrate, 21 and 22: Lower magnetic material, 23 and 25: Protrusion, 24 and 26: Insulating material, 31: Gassop material layer, 41 and 612 interlayer insulating layer, 51: Coil conductor. 7: upper magnetic material, 81: protective layer, A: edge, NE: "
"Negative Edge". Figure 1 Figure 3 Figure 4 Figure 5

Claims (2)

[Claims] (1) In a thin film magnetic head in which a gap material and a coil conductor are laminated with an interlayer insulating layer interposed between the magnetic bodies, the tip 1. A thin film magnetic head characterized in that a protrusion is formed facing a medium facing surface. (2) The tip of the protrusion is set flush with the tip of the lower magnetic body.
1) The thin film magnetic head described in item 1).