JPH0453011A - Thin film magnetic head - Google Patents

Abstract

PURPOSE:To suppress the generation of pseudo signals and to prevent recording efficiency from being lowered by enlarging the cross section of a magnetic path on an upper magnetic core without providing any part parallel to a magnetic gap on the upper face of the upper magnetic core. CONSTITUTION:On the upper face of a base 11, a lower magnetic core 13 is formed in a groove 12 together with this curved groove 12. On the upper face of the base 11, a gap spacer 14 is formed with the same thickness as a desired gap length, and an insulated layer 15 is formed while being attached onto the spacer 14. On the upper face of the layer 15, positive resists 20 and 20 are applied on the both sides of an area, where it is scheduled to form the upper magnetic core, and upside surfaces 20a and 20a are formed while being curved by heating. Next, the excess part of the insulated layer is removed and while remaining insulated layers 151 and 152 on the upper face of the spacer 14, the shapes of upper faces 151a and 152a are curved. Afterwards, an upper magnetic core layer 16' and a protection layer 17 are attached and formed at the exposed part of the spacer 14 and the entire upper faces 151a and 152a. Then, the both sides of the layers 16' and 17 are removed to form a lower magnetic core 16, glass 18 is welded and set on the core 16, and a protection board 19 is joined. Thus, the generation of the pseudo signals is suppressed and the recording efficiency can be prevented from being lowered.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a thin film magnetic head suitable for use in magnetic recording devices such as VTRs (video tape recorders).

(b) Conventional technology Conventionally, this type of thin film magnetic head has been used, for example, in
As shown in Publication No. 46415 (Gl I B5/31), etc., magnetic circuits, conductor coils, electrodes, etc. are formed on a substrate using an insulating layer using a thin film deposition method and photolithography technology. Compared to conventional bulk magnetic heads consisting of a magnetic core and windings, it is easier to downsize and create multiple channels.

However, with such thin-film magnetic heads, increasing the gap depth tends to cause magnetic saturation of the magnetic core.
When used as a head that slides directly against a recording medium such as a VTR, a problem arises in that a sufficient wear life of the head cannot be obtained.

FIG. 12 is a diagram showing the medium sliding contact surface of a conventional thin film magnetic head that eliminates the above-mentioned drawbacks.

This conventional thin-film magnetic head has a groove (2) formed on a substrate (1) made of non-magnetic ceramics, etc., and a lower magnetic core (3), a gap spacer (4), a coil layer, etc. in the groove (2). , an insulating layer (5), an upper magnetic core (6) and a protective film (7).
), and a protective plate (9>) is bonded and fixed on the protective film (7) with a glass (8).In this thin film magnetic head, the lower magnetic core (3) has a protrusion (3a).
By forming a magnetic gap g and defining a magnetic gap g by the protrusion (3a), the trunk width Tw of the magnetic gap g,
Gap depth is defined with high precision. Further, by increasing the distance between the lower magnetic core (3) and the upper magnetic core (6), leakage of magnetic flux is reduced. Furthermore, the 12th
Since the figure shows the medium sliding contact surface, the coil layer and the insulating layer that insulates the coil layer are not shown.

In addition, in the thin film magnetic head with the above structure, the lower magnetic core (
3) and to prevent the generation of false signals from the ends of the upper magnetic core (6), a magnetic gap g is formed between the lower surface of the lower magnetic core (3) and the upper surface of the upper magnetic core (6), respectively.
The curved surface is non-parallel to the surface. However, since the upper surface of the upper magnetic core (6) has a curved shape, the magnetic path cross-sectional area of the upper magnetic core (6) is −L
Interspinning occurs, which becomes smaller toward the surface and reduces recording efficiency. Furthermore, in order to obtain a sufficient magnetic path, it is necessary to make the film yI-1 of the two-part magnetic core (6) sufficiently large, which causes the problem that it is not suitable for mass production.

(c) Problems to be solved by the invention The present invention has been made in view of the drawbacks of the above-mentioned conventional examples.
"It suppresses the generation of spurious signals from the edges of some of the magnetic cores, and it is possible to increase the magnetic path cross-sectional area without increasing the film thickness of the upper magnetic core, thereby preventing low recording efficiency. The object of the present invention is to provide a thin-film magnetic head that has the following characteristics.

(d) The first stage of the present invention for solving the problem is a substrate.Second, a lower magnetic core, a conductive coil layer, an insulating layer covering the conductive coil layer, a gap spacer that becomes a magnetic gap, and an upper magnetic core are deposited. In the thin film magnetic heel, the -E plane of the upper magnetic core is constituted by two planes, a first and a second plane, which widen on both sides centering on the bent part as they move away from the magnetic gap, and both ends of the upper magnetic core The distance between the magnetic gaps is larger than the trunk width of the magnetic gap.

(e) Effect According to the above configuration, the upper surface of the upper magnetic core has a portion parallel to the magnetic gap, and the cross-sectional area of the magnetic path of the upper magnetic core becomes large.

(F) Example Hereinafter, a first example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing the medium sliding contact surface of the thin film magnetic head of the first embodiment.

In the figure, (1) is a substrate made of non-magnetic ceramics or the like, and a groove (12) whose bottom surface (121) is curved is formed on the upper surface of the substrate (11). The groove (12
) is coated with a lower magnetic core (13) made of a ferromagnetic metal material such as sendust. The upper surface of the lower magnetic core (13) is flush with the upper surface of the substrate (11). The upper surface of the lower magnetic core (13) and the substrate (1)
]) A gap spacer (]4) made of a non-magnetic material such as 5iO- is deposited on the upper surface of the gap spacer (]4). An insulating layer (151) (152) made of a non-magnetic material such as SiO, and an upper magnetic core (16) made of a ferromagnetic metal material such as Sendust are deposited on the gap spacer (4). . The lower surface of the upper magnetic core (]6) is provided with a gap spacer (14) on the upper surface of the lower magnetic core (13).
The width of the lower surface of the two-part magnetic core (16) is the trunk width Tw of the magnetic gap g.

1iij the upper magnetic core (16) is connected to the magnetic gap g;
The first and second lower surfaces (161) (162) are separated from the insulating layers (151) (15
2) It has a curved shape that widens on both sides as it moves away from the magnetic gap g along the top surface. Further, the upper surface of the -E section magnetic core (16) has a bent part (16a) in the center, and the bent parts (1, 6&) are arranged in the middle and on both sides as the distance from the magnetic gap g increases. It is composed of first and second upper surfaces (163) and (164) that have a curved shape that expands. The upper magnetic core (16) is the first magnetic core (16) as described above.
, the second lower surface 061) (162) and the first and second upper surfaces (1
63) (164) is configured to extend on both sides as it moves away from the magnetic gap g, so the distance 2 between both ends of the upper magnetic core (16) is exactly the width Tw of the magnetic gap g. larger than The upper magnetic core (]6)
5iO1 on the first and second soil surfaces (163) (164) of
A protective film (17) consisting of the like is deposited.

Further, on the upper magnetic core (16) is glass (1
A protective plate 09) made of Ti acid Ba or the like is bonded and fixed by 8).

Next, a method for manufacturing the thin film magnetic head of the first embodiment will be described.

First, as shown in FIG. 2, the bottom surface (
121) forms a groove (12) having a curved surface shape;
12) A lower magnetic core (13) is deposited and formed in the inside by sputtering, ion beam etching, etc.

Next, as shown in FIG. 3, a gap spacer (14) having a thickness equal to the desired gap length is formed over the entire upper surface of the substrate (11).
) An insulating layer (15) is deposited over the entire area.

Next, as shown in FIG. 4, the soil of the insulating layer (15) is formed.

A positive resist (20) (20) made of novolanc resin is applied to both sides of the area where the upper magnetic core is to be formed on the surface, and a resist is formed by heating the resist (20) (20) to 100 to 150°C. The resist (20) (2) is
0) The upper surface (20a) (20a) is made into a gently curved shape.

Next, the excess portion of the insulating layer is removed by performing ion beam etching or the like from above the substrate (11) shown in FIG.
4) Insulating layers (151) (152) are left on both sides of the upper magnetic core formation area on the upper surface.

The upper surface (151a) of the insulating layer (151,) (152)
(152a) has approximately the same shape as the resists (20) and (20), and the upper surfaces (20a) and (20b) have a gently curved shape.

Next, as shown in FIG. 6, the insulating layers (151) (152
) and a protective layer (
17) is deposited by sputtering or the like.

Next, as shown in FIG. 7, the upper magnetic core layer (16°
) and both sides of the protective layer (17) are removed by reactive ion etching or the like to form a lower magnetic core (16).

Thereafter, the glass (16) is placed above the lower magnetic core (16).
The thin film magnetic head shown in FIG. 1 is completed by melting and solidifying 8), joining and fixing the protective plate (19), and processing the external shape.

In the thin film magnetic head of the first embodiment as described above, since there is no part parallel to the magnetic gap g on the upper surface of the upper magnetic core (16), the upper magnetic core (16)
It is possible to prevent the generation of spurious signals from the ends of the circuit.

Also, the distance between both ends of the upper magnetic core (16)! is always 1) larger than the track width Tw of the magnetic gap g, so the magnetic path cross-sectional area of the corresponding portion magnetic core (16) can be increased without increasing the thickness of the upper magnetic core (16), Recording efficiency is improved.

Next, a second embodiment of the present invention will be described.

FIG. 8 is a diagram showing the medium sliding contact surface of the thin film magnetic head of the second embodiment. The same parts as in FIG.

The upper magnetic core (26) of the second embodiment is branched on both sides from a portion apart from the magnetic gap g by a predetermined distance.
, the second lower surfaces (261) (262) are insulating layers (251) (
252) has a planar shape along the upper surface. Further, the upper surface of the upper magnetic core (26) has a bent portion (26a) in the center.
), and the first and second upper surfaces (263) (264) have a planar shape and extend to both sides around the bent portion (26a).
It is made up of. For this reason, the upper magnetic core (
The distance l between both ends of 26) is always larger than the track width Tw of the magnetic gap g.

Next, a method of manufacturing the thin film magnetic head of the second embodiment will be described.

First, as shown in FIG. 9, a groove (1
2), lower magnetic core (13) and gap spacer (1)
4), planar slopes (251a) (252a) extending on both sides over the entire upper area of the Gambus baser (14) are formed.
) is formed.

Next, as shown in FIG.
4) The insulating layer adhering to the region J- where the upper magnetic core is to be formed on the upper surface is removed by reactive ion etching or the like to divide it into insulating layers (251) and (252). The removed surface (251) of the insulating layer (251) (252)
b) (252b) is orthogonal to the substrate (11) -, 1: plane.

Next, as shown in FIG.
The slopes (251a) (251a) (25) of the insulating layers (251) (252) are
2a) Form a lower magnetic core (26) and a protective film (7) on top.

Thereafter, a glass window 18 is placed above the upper magnetic core 6).
), the protective plate (19) is bonded and fixed to complete the thin film magnetic head shown in FIG.

In the thin film magnetic node of the second embodiment as described above, as in the first embodiment, there is no part parallel to the magnetic gamble g on the L plane of the upper magnetic core (26), so that pseudo signals are generated. This prevents the occurrence of the magnetic core (26
) without increasing the thickness of the upper magnetic core (26
) can increase the magnetic path cross-sectional area, improving recording efficiency.

(G) Effects of the Invention According to the present invention, it is possible to provide a thin film magnetic node that suppresses the occurrence of pseudo No. 411 and prevents a decrease in recording efficiency.

[Brief explanation of drawings]

1 to 7 relate to the first embodiment of the present invention, in which FIG. 1 shows the medium sliding contact surface of the thin-film magnetic head, FIG. 2, and FIG.
4, 5, 6, and 7 are diagrams showing a method of manufacturing a thin film magnetic nodal, respectively. 8 to 11 relate to a second embodiment of the present invention, in which FIG. 8 shows the medium sliding surface of the thin film magnetic head, and FIGS. 9, 10, and 11 respectively show the thin film magnetic head. - It is a figure showing the manufacturing method of the throat. FIG. 12 is a diagram showing the medium sliding contact surface of a conventional thin film magnetic node. (11)... Substrate, (14)... Gap spacer, (16) 1 part magnetic core, (163 111th surface, (764) 21st surface, (16a)... bending part,
g...magnetic gap, T w...track width,! 3,
! ,...distance between both ends. Figure 4 Figure 5 Figure 6 Figure 7

Claims (1)

[Claims] (1) In a thin film magnetic head in which a lower magnetic core, a conductive coil layer, an insulating layer covering the conductive coil layer, a gap spacer serving as a magnetic gap, and an upper magnetic core are deposited on a substrate, the upper magnetic core is A thin film characterized in that the upper surface is constituted by first and second upper surfaces that widen on both sides centering on the bent portion as they move away from the magnetic gap, and the distance between both ends of the upper magnetic core is larger than the track width of the magnetic gap. magnetic head.