JPS63103409A - Thin film magnetic head - Google Patents

Abstract

PURPOSE:To easily make a track form in a narrow shape, and to make a track width itself form with high accuracy, by forming a lower part magnetic core in a cross-sectional rectangular shape, embedding the lower part magnetic core in a substrate, and exposing the plane on the short side of the core on the substrate. CONSTITUTION:The width of the lower part magnetic core 10 embedded in a head substrate 7 with structure in which a second nonmagnetic substrate 9 is laminated on a first nonmagnetic substrate 8, and the cross-section of which is formed in a rectangular shape, that is the length of the short side is formed <=10mum, and the plane of the short side on one side is exposed on the substrate 7 by sandwiching both side planes with the nonmagnetic substrate 9 in the head substrate 7, and it is flushed with the upper plane of the substrate 7. In such way, in the titled thin film magnetic head, the gap width of the head is decided by the gap width of the lower magnetic core 10, that is, the length of the short side, thereby, it is possible not only to constitute it smaller than the processing width of etching of an upper part magnetic core 14 considerably, but, to prevent the gap width from being affected by the thickness of the upper part magnetic core 14 even when it is formed in a thick shape considerably.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thin film magnetic head installed in a magnetic recording/reproducing device.

[Conventional technology]

2. Description of the Related Art Conventionally, with respect to magnetic heads installed in magnetic recording and reproducing devices, development and practical use of thin film magnetic heads using thin film technology have been progressing in order to reduce the size of the heads and improve mass productivity.

This thin film magnetic head has a substrate (1
), a film-like lower magnetic core (2) is formed by vapor deposition or sputtering, and then a gap spacer layer (3) and a conductor coil layer (4) are formed using photolithography technology.
), an insulating layer (5), and a film-like upper magnetic core (6) are sequentially laminated, and this type of thin-film magnetic head is described, for example, in Japanese Patent Application Laid-Open No. 170013/1983 (GIIB
5/31) It is also shown in the official gazette.

On the other hand, in recent years, in magnetic recording technology, in order to improve recording density, (1) increasing the coercive force of the recording medium and shortening the recording wavelength (improving linear density) (11) decreasing the track width of the recording track (Improvement of track density)

Also in the thin film magnetic head, in order to improve the recording density as described above, (I) In order to improve the recording density on a high coercive force medium, the saturation magnetic flux density of the magnetic core is improved, and the film of the magnetic core is Technological developments are underway to make the track width as small as possible using (II) photolithography technology, which makes the track width as thick as possible and prevents the saturation of magnetic flux inside the core, especially during recording.

However, in the etching process using photolithography technology (II), there are limits to the minimum etching width and etching accuracy due to side etching, depending on the copying of the film to be etched. The minimum track width and accuracy (variation) are limited by the film thickness.

That is, FIG. 6 shows the gap plane of a thin-film magnetic head, and the track width t of this head is determined by the thickness of the gap spacer layer (3) laminated on the lower magnetic core (2) and gap spacer layer (3) processed by photolithography. It is determined by the width of the bottom of the upper magnetic core (6).

Here, in the photoetching process, as mentioned above, side etching inevitably occurs on the film to be etched (magnetic core), and the etched surface becomes an inclined surface with an angle of ±θ (0° and θ<90°). As a result, the cross section of the upper magnetic core (6) has a track width t at the bottom and a film J! at the height. It becomes a trapezoid of ¥d.

By the way, as mentioned in (I) above, in order to provide a high coercive force recording medium such as a metal tape with sufficient recording capacity, it is necessary to prevent saturation of the magnetic flux inside the core during recording. It is required to form the magnetic core with a thick film thickness, and it is thought that a film thickness of 10 μm or more is necessary.

On the other hand, the angle θ of the side etching described above is usually 45° or more, and even if an ion beam etching method with high directionality is used, it is at most 30° or more.

As a result, when the film thickness d of the upper magnetic core (6) is kept at 10 μm, the track width t is limited to 12 to 20 μm.
If you try to make it smaller than this, as shown in Figure 7,
The upper magnetic core (6) has a triangular cross-section, the film thickness d is 10 μm or less, and the cross-sectional area is smaller, making saturation of magnetic flux inside the core more likely to occur during recording, making it a high coercive force recording medium. becomes difficult to record.

Furthermore, as described above, the track width of this type of thin film magnetic head is determined by the width of the bottom of the upper magnetic core (6) formed by photolithography; 6) As the film thickness increases, it is affected by variations in etching time and side etching angle. For example, when etching a film thickness of 10 μm, variations of ±2 μm or more are unavoidable, which limits the track width accuracy. This is disadvantageous in terms of yield.

[Problem that the invention seeks to solve]

This invention was made with the above points in mind,
In a thin film magnetic head, an upper magnetic core and a lower magnetic core have sufficient core thickness, the track width can be controlled to be narrower, and the dimensional accuracy of the track width can be improved. It is something.

[Failure to solve the problem]

The present invention provides a magnetic head in which a lower magnetic core, a gap spacer 'J, a conductor coil layer, and an upper magnetic core are sequentially formed on a substrate, in which the lower magnetic core has a rectangular cross section, and the lower magnetic core has a rectangular cross section. The present invention is characterized in that the lower magnetic core is buried, and the shorter side surface of the core is exposed on the substrate.

[For production]

Therefore, according to the present invention, the track width of one magnetic head is determined by the width of the lower magnetic core with a rectangular cross section embedded in the substrate, that is, the length of the short side. The track width can be regulated with high precision by the structure, and even if the width of the upper magnetic core is made larger than the length of the short side of the lower magnetic core, the track width will not be affected in any way, and the lower magnetic core In addition, it becomes possible to form the upper magnetic core with a sufficient thickness.

〔Example〕

Next, the present invention will be explained in detail with reference to FIGS. 1 to 4 showing one embodiment thereof.

First, let's start with Figure 1, which shows the structure of a magnetic head, and Figure 2.
In the figure, (7) is a head substrate having a structure in which a second non-magnetic substrate (9) is laminated on a first non-magnetic substrate (8);
is a thin strip-shaped lower magnetic core with a rectangular cross section embedded in the substrate (7), and the width of the core αQ, that is, the length of the short side, is formed to be 10 μm or less, and the core is embedded in the head substrate (7). Both sides are held between non-magnetic substrates (9), and one short side surface is exposed on the substrate (7) and is flush with the top surface of the substrate (7).

01) is a gap spacer layer formed in the vicinity of the front gap on the substrate (7), and θ is a conductive coil layer formed behind the front gap on the substrate (7) via an insulating film. , α East is S i on the conductor coil layer (2)
02 is an insulating layer formed by vapor deposition etc., and Q→ is a gap spacer layer 01. The upper magnetic core is formed as a film over the upper surface of the insulating layer @ and the lower magnetic core 00, and is wider than the width (length of the short side) of the lower magnetic core αO, that is, 1
Both cores Ql (14) are formed as a gap spacer layer of 0μm or more in the front gap part.
and both cores QQ at the back gap part.
, Q→ are in contact.

Therefore, in the thin film magnetic head having the above configuration, the track width is determined by the width of the lower magnetic core 27010, that is, the length of the short side, and can not only be configured to be sufficiently smaller than the etching width of the upper magnetic core Q4). Even if the upper magnetic core Q→ is configured to have a sufficient thickness, the track width will not be affected in any way.

Next, a method for manufacturing the thin film magnetic head will be explained with reference to FIGS. 3 and 4.

First, as shown in FIG. 3(a), a magnetic film α9 such as Sendas l- or Go-based amorphous film is deposited on a non-magnetic substrate (9) made of galanus, ceramic, etc. by sputtering or vapor deposition. A film is formed to a thickness corresponding to the track width (for example, 5 to 10 μm).

Then, a plurality of substrates (9) on which the magnetic film α9 has been formed are laminated and bonded to form a block body α, as shown in FIG.
The block body αQ is sliced into a dimension corresponding to the core thickness of the lower magnetic core 00 to obtain a sliced substrate 0η shown in FIG.

Furthermore, as shown in FIG. 2(d), the sliced substrate (17) is bonded onto the non-magnetic substrate (8), and the head substrate (
Complete 7). At this time, the magnetic film 05 of the sliced substrate αη becomes the lower magnetic core 00 with a rectangular cross section, and the core O
Q is buried in the substrate (7), and the short side surface of the core Ql is exposed on the substrate (7).

Next, as shown in FIG. 4(a), a gap spacer layer 0η is formed in the vicinity of the front gap on the head substrate (7) obtained as described above.

At this time, an insulating film such as an 8102 film is formed on the substrate (7) at a portion where the conductor coil/1/layer (2) contacts. For example, after forming an insulating film on the entire surface of the substrate (7), the insulating film is formed on each of the front gap part where the gap spacer layer αυ is formed and the pack gap part where the upper magnetic core αυ contacts the substrate (7). is removed by etching, and then the gap spacer layer Q1) is formed.

Furthermore, as shown in FIG. 2(b), a conductive coil layer (a) is formed on the substrate (7) by photoetching or the like.

After that, as shown in the same figure (C), an insulating layer Oe made of vaporized SiO2 film or polyimide resin is formed on the part of the conductor coil layer where the upper magnetic core Q→ is formed, and then the upper magnetic core Q→ is formed. The core α→ is formed by sputtering and photolithography.

Therefore, in the thin film magnetic head obtained as described above, the width of the lower magnetic core 00 that regulates the track width is
Since it is controlled by the thickness of the magnetic layer Q9 formed by evaporation or sputtering, the track width can be easily reduced from IO μm to several μm, and the accuracy can be reduced to ±0.
．． The thickness can be set to 2 μm or less.

The lower magnetic core αG may be formed by vapor deposition or sputtering as explained in the examples, or may be formed by forming a Co-Fe-based amorphous ribbon or Sendust ribbon to a predetermined thickness (corresponding to the track width). , laminated with the substrate (9) in the same way as described in FIG.

The head substrate (
7) and may be a lower magnetic core (IcI).

In this case, the track width can be controlled by machining (polishing, etc.) of the film formed on the thin strip as the lower magnetic core 0q, and as in the case described above, it is possible to narrow the track width and improve precision. .

〔Effect of the invention〕

As described above, according to the thin film magnetic head of the present invention, the track width can be controlled by the width (length of the short side) of the lower magnetic core having a rectangular cross section. It is possible to achieve high-precision changes in the magnetic core itself, and high-density recording is possible by narrowing the track.Furthermore, this track width is not affected by the core speed of the upper and lower magnetic cores, and the track width is narrow and the core is sufficiently thick. Even when recording on a high coercive force recording medium, saturation of the magnetic flux inside the core does not occur, and the recording density can be improved.

[Brief explanation of the drawing]

1 to 4 show one embodiment of the thin film magnetic head of the present invention, in which FIG. 1 is a perspective view, FIG. 2 is a front view, and FIGS. 3(a) to 4(d) are head substrates, respectively. Figure 4 (a) to (C) are perspective views showing the manufacturing process of a thin film magnetic head, respectively. Figures 5 and below show a conventional thin film magnetic head; Figure 5 is a perspective view , Figures 6 and 7
Each figure is a front view. (7)... Head substrate, 00... Lower magnetic raw core, αυ... Gap spacer layer, 04... Conductor coil layer, Q4)... Upper magnetic core.

Claims (1)

[Claims] (1) On the substrate, a lower magnetic core, a gap spacer layer,
In a thin film magnetic head formed by sequentially forming a conductive coil layer and an upper magnetic core, the lower magnetic core has a rectangular cross section, the lower magnetic core is embedded in the substrate, and the short side surface of the core is A thin film magnetic head characterized by being exposed on a substrate.