JPH03219409A - Thin film magnetic head - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thin film magnetic head, and particularly to the relative structure of a magnetic path and a coil that constitute a thin film magnetic head.

[Prior Art] As shown in FIGS. 6 and 7, the relative structure of the core and coil of a conventional thin-film magnetic head is as follows. The bottom magnetic pole is 1
It has a circularly interlinked shape. That is, each time,
1 is a substrate, 2 is an insulating layer, 3 is a lower magnetic pole deposited on the surface of this insulating layer 2, 4 is a gap layer, 5 is a resist layer,
6 is a coil wound in a ring shape on the surface side of the insulating layer 2, 7 is an upper magnetic pole, 8 is a protective film layer, 9 is an upper/lower magnetic pole junction, 10.11 is a coil terminal, and A is a thin film magnetic The surface of the head facing the recording medium is shown. In this case, the upper magnetic pole 7 has a heart shape and is located above a part of the bundle portion 6a of the coil 6, and forms a magnetic path F with the lower magnetic pole 3 on the lower side. On the recording medium facing surface A, the tip side 7 of the upper and lower magnetic poles 7, 3
t.

3t are opposed to each other with the gap layer 4 interposed therebetween.

A thin film magnetic head having such a structure is mounted, for example, on the rear end surface of a head slider of a magnetic disk device.

Next, the operation will be explained.

During a recording operation, by applying a signal voltage to the coil terminals 10.11, a current corresponding to the signal voltage flows through the coil 6, and this current causes the upper magnetic pole 7. A magnetic flux corresponding to this current is generated inside the lower magnetic pole 3. This magnetic flux is transferred to the upper magnetic pole 7. Lower magnetic pole 3
The magnetic path F formed at the tip sides 7t and 3t leaks out at the gap layer 4, and this leakage magnetic flux magnetizes a recording medium (not shown) placed in close proximity. .

In addition, during reproduction, the magnetic flux generated by the magnetization on the recording medium is taken into the magnetic path F through the gap layer 4, and this causes the coil 6 interlinked with the magnetic path F to generate a magnetic flux proportional to the temporal change in the magnetic flux. A voltage is induced. The induced voltage e at this time is 6 cc N dφ/dT, and the number of turns N of the coil 6 and the magnetic flux φ interlinking with the coil 6
is proportional to the amount of change over time. A magnetic head is required to make this induced voltage e as large as possible.

[Problems to be Solved by the Invention] Since the conventional thin film magnetic head has the above structure, in order to increase the induced voltage e during the reproducing operation, it is necessary to increase the number of turns N of the coil 6 or to increase the magnetic flux φ. There is no choice but to make the temporal change rapid. However, increasing the number of turns N causes the problem that the wire length of the coil 6 becomes longer, which increases the resistance value and increases head noise. In addition, various methods have been taken such as increasing the cross-sectional area of the coil 6 so that the resistance value does not increase even if the number of turns N is increased, or creating a coil shape that allows the wire length to be as short as possible. It is difficult not to increase the value. Furthermore, it is difficult to make the magnetic flux φ change rapidly over time due to factors such as the recording medium and the magnetic pole material.

This invention was made to solve the above-mentioned problems, and an object of the present invention is to obtain a thin-film magnetic head that can increase the induced voltage e without increasing the resistance value of the coil during reproducing operation. .

[Means for Solving the Problems] The thin-film magnetic head of the present invention includes a coil formed by winding it in a ring shape on the surface side of an insulating layer, and 3-. a main magnetic path section consisting of a lower magnetic pole and an upper magnetic pole whose tips face each other with a constant gap layer interposed therebetween, and a lower magnetic pole and an upper magnetic pole located on the lower side and upper side of a part of the bundle section. An auxiliary magnetic path section consisting of the above is provided, and the auxiliary magnetic path section is connected to the main magnetic path section.

[Function] Due to the structure of the magnetic path and coil of the thin film magnetic head of the present invention, linkage with the coil can be obtained not only in the main magnetic path but also in the auxiliary magnetic path, without increasing the number of turns N of the coil. , ie without increasing the resistance of the coil and also the recording medium.

The temporal change in magnetic flux φ can be made rapid without changing the magnetic pole material, etc., and the induced voltage e can be increased.

[Embodiment of the Invention] An embodiment of the invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 is a plan view showing a thin film magnetic head according to the present invention, and FIG. 2 is a view seen from direction B in FIG. , and the explanation thereof will be omitted.

In each round, 3a, 3b are the lower magnetic poles of the present invention, 7a,
7b is an upper magnetic pole; 9a, 9b, and 9c are upper and lower magnetic pole junctions; Fa is a main magnetic path portion; and Fb is an auxiliary magnetic path portion.

In this case, the gap layer 4 is provided on the recording medium facing surface A side, and the main magnetic path section Fa that supplies magnetic flux onto the recording medium and takes in magnetic flux from the recording medium is connected to the lower magnetic pole 3a and the upper magnetic pole 7a. It consists of The lower magnetic pole 3a and the upper magnetic pole 7a are formed of thin pieces such that their front ends 3u and 7u face each other with a gap layer 4 interposed therebetween, and their rear ends are gradually spaced apart to form a space S. Further, they are arranged in the space S in an approximately 7-shape, and each tip is connected to each other via the joint part 9b,
The lower magnetic pole 3b and the upper magnetic pole 7b constitute an auxiliary magnetic path section Fb, each of which is a thin piece whose rear ends are connected to the rear ends of the lower and upper magnetic poles 3a and 7a through joints 9a and 9c. .

Next, we will discuss the reproducing operation of the thin film magnetic head with the above configuration. 61 I will explain.

The magnetic flux generated by the magnetization on the recording medium passes through the gap layer 4 from the recording medium to the upper magnetic pole 7a and the upper/lower magnetic pole junction 9.
a-lower magnetic pole 3b-1 upper/lower magnetic pole junction 9b-upper magnetic pole 7b-upper/lower magnetic pole junction 90-lower magnetic pole 33m
The light passes in the opposite direction to the above depending on the recording medium or the direction of magnetization on the recording medium. The magnetic path consisting of the upper and lower magnetic poles is connected to the coil 6 by the main magnetic path section Fa and the auxiliary magnetic path section Fb.
Therefore, the magnetic flux passing through the magnetic path also interlinks with the coil 6 twice, and the induced voltage e becomes eccd (2φ)/d t=2Ndφ/dt. ,
The same effect as doubling the number of turns of the coil 6 can be obtained. Furthermore, since the structural number of turns of the coil 6 remains N, the resistance value does not increase, and an increase in noise due to the resistance value is suppressed.

Next, another embodiment of the present invention will be described based on FIGS. 3 to 5.

3 is a plan view showing another embodiment of the thin film magnetic head of the present invention, FIGS. 4(a) and 4(b) are sectional views thereof, and FIG.
) and (b) are diagrams showing the bonding state of each magnetic pole, and the same parts as in the conventional example of FIGS. 6 and 7 are given the same reference numerals, and the explanation thereof will be omitted.

In this case, the bundle part 6b of the bundle part 6a of the coil 6 is in the opposite direction to the main magnetic path part Fc consisting of the lower magnetic pole 3a and the upper magnetic pole 7a.
At the position, the lower magnetic pole 3 is placed across the bundle portion 6b.
b and the upper magnetic pole 7b are arranged on the upper and lower sides. This lower part
The upper magnetic poles 3b and 7b are made of elongated magnetic bodies extending in the direction of the main magnetic path section Fc, their rear ends are connected to each other via a joint 9b, and their tips have tongues ρ2m on the opposite side. The tongue l of the upper magnetic pole 7b is connected to the tongue n of the lower magnetic pole 3a through the joint 9C, and the tongue m of the lower magnetic pole 3b is connected to the tongue 0 of the upper magnetic pole 7a through the joint 9a. . The lower magnetic pole 3b and the upper magnetic pole 7b form an auxiliary magnetic path portion Fd.

In this embodiment, the same functions and effects as in the above-mentioned embodiments can be obtained, and since the magnetic poles of this embodiment are formed almost perpendicular to the medium surface, the domain wall 7- is oriented with respect to the medium surface. Since they are parallel, the magnetization process is performed without movement of the domain walls, and the generation of noise is also suppressed.

[Effects of the Invention] As explained above, according to the present invention, a coil is formed by winding it in a ring shape on the surface side of an insulating layer, and a coil is located on the lower side and the upper side of the bundle portion of the coil, A main magnetic path section consisting of a lower magnetic pole and an upper magnetic pole whose tips face each other with a constant gap layer interposed therebetween, and an auxiliary magnetic path section consisting of a lower magnetic pole and an upper magnetic pole located below and above a part of the bundle section. Since the auxiliary magnetic path section is connected to the main magnetic path section, the induced voltage e during reproduction has the same effect as the apparent increase in the number of turns N of the coil, and the resistance of the coil increases. As for the value, an increase can be avoided because the structural number of turns N is not increased, so an increase in noise due to the resistance value can be avoided, and a thin film magnetic head with a good S/N ratio can be obtained.

[Brief explanation of drawings]

1 and 2 are plan views of a thin 8-film magnetic head according to an embodiment of the present invention, FIG. 2 is a view seen from direction B in FIG. 1, and FIGS. 3 to 5 are views according to the present invention. FIG. 6 is a plan view of a conventional thin-film magnetic head, and FIG. 7 is a cross-sectional view thereof. 2... Insulating layer, 3a, 3b... Lower magnetic pole, 4...
Gap layer, 6... Coil, 6a, 6b... Bundle part,
7a. 7b...Top magnetic pole, 9a, 9b, 9c...Top/bottom magnetic pole junction pQ, pQ...Main magnetic path part, F
b, Fd... auxiliary magnetic path section.

Claims (1)

[Claims] A coil formed by winding in a ring shape on the surface side of an insulating layer, and a lower magnetic pole and an upper magnetic pole located on the lower and upper sides of the bundle part of the coil, and whose tips face each other with a constant gap layer interposed therebetween. A main magnetic path section consisting of a main magnetic path section, and an auxiliary magnetic path section consisting of a lower magnetic pole and an upper magnetic pole located below and above a part of the bundle section, and the auxiliary magnetic path section is connected to the main magnetic path section. A thin film magnetic head characterized by being connected to the