JPH04229406A - Thin-film magnetic head - Google Patents

Abstract

PURPOSE:To suppress an eddy current loss and to easily detect off tracking by parting an upper information core on a back side, forming the width of a working gap wider than a track width and providing conductor coils in corresponding to respective back parts. CONSTITUTION:The lower information core 2 is formed on a substrate 1. An insulating film and gap spacer are deposited and formed on the core 2. The conductor coils 3a to 3g are formed in the upper part of this insulating film. The upper magnetic core 4 is formed to cover the gap spacer and respective coils 3a to 3g, by which a head element 5 is formed. Namely, the core 4 is formed by dividing the back side so as to have the back core parts 6a to 6g corresponding to the respective coils 3a to 3g. The conductor coils 3a to 3g are formed around the respective back core parts 6a to 6g. A working gap 7 wider than the track width W is formed between the core 4 and the gap spacer.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film magnetic head suitable for high density recording.

0002

2. Description of the Related Art Conventionally, this type of thin film magnetic head has been disclosed in, for example, Japanese Unexamined Patent Publication No. 1-279407 (G11B
5/31), etc.

FIG. 8 is a front view showing the main parts of a conventional thin film magnetic head. The magnetic head of FIG. 8 consists of a substrate (21) made of magnetic or non-magnetic material, a lower magnetic core (22) made of a ferromagnetic metal material such as sendust, an operating gap (23), a conductor coil (24), and a non-magnetic material. A head element (25) is formed by sequentially laminating an insulating film (not shown) made of a magnetic insulating material and an upper magnetic core (26) made of the same material as the lower magnetic core (22), and bonded onto the head element. It is completed by melting and fixing a protective plate (not shown) made of a non-magnetic material through a glass layer (not shown).

However, when the conventional thin film magnetic head is used for reproduction, in order to detect or correct tracking deviation, the thin film head is installed on a member made of a piezoelectric element, and a voltage is applied to the piezoelectric element. It is necessary to mechanically displace the thin film magnetic head, which poses a problem in that the reproducing device becomes complicated.

Another problem is that eddy currents are generated in the upper magnetic core of the thin film magnetic head, deteriorating the reproduction characteristics.

[0006]

[Problems to be Solved by the Invention] The present invention has been made in view of the drawbacks of the above-mentioned conventional examples, and it is possible to suppress eddy current loss, facilitate detection of tracking deviation, or suppress deterioration in reproduction ability. The object is to provide a thin film magnetic head.

[0007]

Means for Solving the Problems In a thin film magnetic head having a working gap between an upper magnetic core and a lower magnetic core formed on a substrate, the working gap width is wider than the track width, and the working gap is wider than the track width. The upper magnetic core is divided and formed to have a plurality of back core parts, and a conductor coil is formed around each of the back core parts.

[0008]

[Operation] Since the upper magnetic core is formed by being divided so as to have a plurality of back core portions with respect to the working gap, loss due to eddy current in the upper magnetic core is prevented.

Furthermore, since the operating gap width is wider than the track width, the upper magnetic core is divided into a plurality of back core parts, and a conductor coil is provided corresponding to each back core part, It is possible to efficiently reproduce information by comparing the outputs of each conductor coil.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a perspective view showing the main parts of the magnetic head of this embodiment, and FIG. 2 is a perspective view showing the external appearance of the magnetic head.

In the figure, (1) is a 1 mm thick substrate made of a magnetic material such as Mn--Zn ferrite or a non-magnetic material such as crystallized glass. On this substrate (1), a lower magnetic core (10 μm thick) made of a magnetic thin film such as Sendust (
2) is formed by adhesion.

Although not shown, an insulating film made of SiO2 or the like having a thickness of 1 μm and a gap spacer having a thickness of 0.2 μm are formed on the lower magnetic core (2).

[0014] On top of the insulating film, a conductor coil made of Cu or the like and an interlayer insulating layer made of SiO2 or the like are deposited in this order to form seven conductor coils (3a) (3b).
(3c) (3d) (3e) (3f) (3g) are formed. (4) is an upper magnetic core with a thickness of 10 μm,
Above the gap spacer and each conductor coil (3a) (3
b) A head element (5) is formed by covering over (3c) (3d) (3e) (3f) (3g). That is, the upper magnetic core (4) has each conductor coil (3
a) (3b) (3c) (3d) (3e) (3f) (3g
) 7 back core parts (6a) (6b) (6
c) (6d) (6e) (6f) (6g) The back side is formed by being divided into seven parts, and each back core part (6a) (6b) (6c) (6d) ( 6e) (
6f) (6g) around each conductor coil (3a) (3b)
(3c) (3d) (3e) (3f) (3g) are formed.

Between the upper magnetic core (4) and the gap spacer, there is an operating gap (wider than the track width W).
7) is formed.

As shown in FIG. 2, a protective film (not shown) made of SiO2 or the like is deposited on the head element (5), and a reinforcing substrate made of barium titanate or the like is further formed on top of the protective film (not shown). (9) is fixed with a welded glass (8) to form a thin film magnetic head.

Next, a method for manufacturing the thin film magnetic head of this embodiment will be explained in detail with reference to FIGS. 3 to 6.

First, as shown in FIG. 3, a layer of high permeability magnetic material such as sendust having a thickness of about 10 μm is applied to the entire upper surface of a substrate (1) made of a magnetic material such as Mn-Zn ferrite or a non-magnetic material such as crystallized glass. A magnetic thin film is deposited using thin film forming techniques such as sputtering and vacuum evaporation.
A lower magnetic core (2) is formed. Then, an insulating film (not shown) made of SiO2 or the like with a thickness of 1 μm is formed on the lower magnetic core (2) using the same thin film forming technique.

[0019] Thereafter, a conductor coil (3d) made of Cu or the like with a thickness of 2 μm is deposited on the upper surface of the insulating film using a thin film formation technique and an etching technique such as ion milling. An interlayer insulating film (not shown) made of SiO2 or the like with a thickness of 1 μm is deposited over the entire area using a thin film forming technique.

Next, as shown in FIG. 4, the conductor coil (
conductor coils (3c) (3e) so as to cover part of the conductor coils (3d)
) is deposited and formed in the same manner. After that, conductor coil (3c)
(3e) A 1 μm thick non-magnetic film (not shown) such as SiO2 is deposited over the entire upper surface using thin film formation technology.
do.

By repeating the same process as above, conductor coils (3a) (3b) (3c) (3d) as shown in FIG.
(3e), (3f), and (3g) are deposited, and then a 1 μm thick protective film (not shown) of SiO2 etc. is formed over the entire area.
is deposited using thin film formation technology.

Next, a magnetic thin film (not shown) made of a high permeability magnetic material such as Sendust is deposited on the protective film using the same thin film forming technique. Thereafter, a resist is applied onto the magnetic thin film, exposed through a photomask, and developed to leave the resist in the shape of the upper magnetic core. Thereafter, the magnetic thin film is etched using an etching technique such as ion beam etching, thereby forming an upper magnetic core (10) as shown in FIG.

Thereafter, the thin film magnetic head shown in FIG. 2 is completed using the same method as for forming a conventional thin film magnetic head.

In the thin film magnetic head of this embodiment, the upper magnetic core (10) is separated on the back side, so the upper magnetic core (10) has an elongated shape, which suppresses eddy current loss. I can do it.

Further, in this thin-film magnetic head, the width of the working gap (7) is formed wider than the track width W, and the back side of the upper magnetic core (10) is divided, and each Back core (6a) (6b) (
Conductor coils (3a) (3b) (3c) (3d) (3e) (corresponding to 6c) (6d) (6e) (6f) (6g)
3f) (3g), so for example, when recording information, five conductor coils (3b) (3g) excluding both ends are provided.
c) A signal is sent to (3d) (3e) (3f) to record information of a predetermined track width, and these conductor coils (3b) (3c) (3d) (3e) ( 3
f) and the conductor coils (3a) and (3g) at both ends are used to detect tracking deviation.
From the output of a) (3g), it is possible to determine in which direction the magnetic head is deviated with respect to the track, and tracking deviation can be detected.

[0026] Furthermore, when a tracking deviation occurs during the above-mentioned reproduction, the conductor coils (3a) (3b) (3c) (3
d) Out of (3e) (3f) (3g), only the outputs exhibiting similar frequency characteristics (for example, (3a) (3b) (3c) (3d) (3e) of 6 out of 7 conductor coils. (3
f) and the added output is used as the reproduced output. By doing this, it is possible to suppress a decrease in output due to tracking deviation.

In the thin film magnetic head of the above embodiment, the upper magnetic core is divided on the back side and not on the front side, but as shown in FIG. 7, the front side is made of a non-magnetic thin film (50) such as SiO2. It may also be a separate structure.

Further, although the conductor coils are formed so as to partially overlap each other, they may be structured so that they do not overlap.

[0029]

[Effects of the Invention] According to the present invention, the recording and reproducing efficiency is excellent;
A thin film magnetic head that can easily detect tracking deviation can be provided. Furthermore, it is possible to provide a thin-film magnetic head that has excellent recording and reproducing efficiency and can suppress a decrease in output due to tracking deviation.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing essential parts of a thin film magnetic head according to an embodiment of the present invention.

FIG. 2 is a perspective view showing the appearance of the thin film magnetic head.

FIG. 3 is a front view showing the manufacturing process of the thin film magnetic head.

FIG. 4 is a front view showing the manufacturing process of the thin film magnetic head.

FIG. 5 is a front view showing the manufacturing process of the thin film magnetic head.

FIG. 6 is a front view showing the manufacturing process of the thin film magnetic head.

FIG. 7 is a perspective view showing the appearance of a thin film magnetic head according to another embodiment of the present invention.

FIG. 8 is a perspective view showing the main parts of a conventional thin film magnetic head.

[Explanation of symbols]

(1) Substrate (2) Lower magnetic core (3a) (3b) (3c) (3d) (3e) (3f) (
3g) Conductor coil (4) Upper magnetic core (7) Operating gap

Claims (1)

[Claims] 1. A thin film magnetic head having a working gap between an upper magnetic core and a lower magnetic core formed on a substrate, wherein the working gap width is wider than the track width, and a plurality of magnetic heads are provided with respect to the working gap. The upper magnetic core is divided to have a back core portion of
A thin film magnetic head characterized in that a conductor coil is formed around each of the back core parts.