JPS6286516A - Thin film magnetic head - Google Patents

Abstract

PURPOSE:To improve the magnetic anisotropy and to improve the manufacturing yield by patterning the core material on the substrate and forming the long and belt-shaped lower part core in the track width direction. CONSTITUTION:On a non-magnetic substrate 21, the groove for the lower part core is provided, the thin film of a core material 22 is sputtered, and thereafter, the film is lapped unit it comes to be an embedded condition on the substrate 21, and in the track width direction, a long-belt-shaped lower part core 22 is formed. On this, a signal coil 23 and a bias coil 24 are patterned and insulated by the interlayer material. An upper part core 26 is patterned and formed by the same material as the lower part core 22. Consequently, the lower part core 22 travels so as to link the edge part of the head chip under the upper part core 26 and is connected to the upper part core 26 by a core connecting part 29. Consequently, the disconnection, the short, etc., of the wiring part due to the projected substance from the lower part core are decreased, and the magnetic anisotropy and the manufacturing yield can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a thin film magnetic head with improved magnetic anisotropy and manufacturing yield.

[Background of the invention]

The conventional thin-film magnetic head is described in Miyahito et al., "Thin-film head for high-density magnetic recording sheets," Technical Report of the Institute of Electrical Communication Engineers, MR84-
12, 1984, 6, PP 55-60, a lower magnetic film (lower core) is formed on the substrate, and then an interlayer material, a coil conductor, an upper magnetic material (upper core), etc. are sequentially formed. By forming and patterning them, a coil and an upper core of a desired shape are obtained, and a thin film head is obtained. However, the shape of the lower core is not patterned on the substrate. For this reason, no consideration was given to improving the magnetic anisotropy of the lower core and improving the manufacturing yield.This point is explained in Fig. 8.Fig. FIG. 3 is a top view of an intersecting substrate illustrating an axis of easy magnetization that occurs in FIG.

1 is the substrate, 2 is the domain wall%, and 3 is the axis of easy magnetization.

In the figure, if the axis of easy magnetization 3 is oriented in a direction perpendicular to the track width, the difference in position on the substrate 1 will cause anisotropy variation in the track portion of each head chip, and even performance variation. becomes. It is known that in a thin film head, it is good to form the axis of easy magnetization in the track width direction. However, even if the lower core is formed so that the axis of easy magnetization points in the track width direction, if the substrate is heated in a magnetic field during subsequent process conditions, such as sputtering, the axis of easy magnetization Also, when forming a film by sputtering, large protrusions of several hundred micrometers in size may occur on the film surface. As a conventional example, buttering the lower core causes breakage or short-circuiting, which leads to a decrease in p% sea bream yield.

Robert E. Jones, Jr.
IBM3370 F'i1mHead Design
and Fabrication J I B M
Disk Storage Technology,
February 1980.

However, in terms of improving magnetic anisotropy, the TitS core shape was not designed in the same way as in the previous example.

[Purpose of the invention]

An object of the present invention is to provide a lower magnetic material (
The object of the present invention is to provide a thin film magnetic head that can achieve improved magnetic anisotropy and manufacturing yield by optimizing the structure of the lower core.

[Summary of the invention]

After achieving this goal, the next step is F! A is to form the lower core in a structure that does not affect the track portion of each head chip due to the difference in position on the substrate, and to prevent protrusions from appearing on the wiring portion during the next sputtering. We found that the drawbacks of the conventional technology could be solved by using K, and we buttered the lower core so that its shape was lengthened in the track width direction so that the demagnetizing field coefficient in the track width direction was the smallest, and we heated it during the process. It is also characterized in that the magnetic anisotropy can be maintained and controlled in the track width direction due to the shape effect even when a magnetic field is applied.

The present invention aims to improve the reduction in manufacturing yield due to wire breakage and short circuits caused by protrusions from the lower core by adopting the above-described structure. Also,
When patterning using thin film technology, it is advantageous for the surface to be patterned to be nearly flat, so the lower core material is buried in the substrate or interlayer material, and the surface is flattened by lapping or a flattening process. A method of manufacturing chips would be advantageous.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing a first embodiment in which a thin film magnetic head according to the present invention is applied to a thin film multi-track recording head;
Figure 2 is a top view of the lower core material, Figure 6 (a), (b)
4 is a process diagram for explaining the method of forming the lower core, and FIG. 4 is a top view of a thin film magnetic head using the lower core formed by the method shown in FIG. 5(a).

In FIG. 1, 21 is a non-magnetic substrate, 22 is a lower core, 26 is a signal coil, 24 is a common bias coil, 25
26 is an interlayer material, 26 is an upper core, 27 is a thermal membrane and a bonding layer, 28 is a protective plate, and 29 is a core connection portion.

In Fig. 2, 21 is a non-magnetic substrate, and 32 is a groove for the lower core.◎ In Fig. 3, (a) and (b) are the A-
In the following process diagram from the A' cross section, 21 is a non-magnetic substrate, 32
is a groove for the lower core, 22 is a lower core, 45 is a mask material, 4
6 is resin.

In Figure 4, 211I'i non-magnetic substrate % 22 is the lower core, 25.24 is the coil, 26 is the upper core, 29
is the core connection.

The thin film multi-track recording head shown in Figure 1 has a track width 'r, = 65 μm, ) at a rack pitch.

= 80 μm, ) The number of racks is 22, and the coil is formed of one turn per layer with a common bias coil. Each coil 25.24 is insulated from each other by an interlayer material 25, and is sandwiched between upper and lower cores 26.22. The lower core material is as shown in Fig. 2 and Fig. 6(&)K. Then, the head chip pitch Hp=6r on the non-magnetic substrate 21
Cut the groove 52 for the lower core to a depth of 30 μm using a screwdriver.
m%@h=300 μm, and after sputtering a Co-N1)-Zr based amorphous film as the lower core material 22 shown in FIG. 1 to a film thickness of 50 μm, the depth of the lower core groove 32 was The core is lapped until it reaches a thickness of 20 μm to obtain a band-shaped lower core in the track width direction. and.

Thereon, a signal coil 23 and a common bias coil 24 were patterned using aluminum using a thin film forming technique, and the upper core 26 was made of the same material as the lower core 22 and was completely patterned by sputtering to a thickness of 20 μm.

As the interlayer material and gap material 25, a 5iOz film was used. In addition, the front gap length gl! is g/=α5μ
m, and the upper and lower cores were connected by a rear core connection part 29.

As shown in FIGS. 1 and 4, the lower core 22 runs under the upper core 26 so as to connect the ends of the head chips, and is connected to the upper core 26 at a core connecting portion 29. is the same as above.

As a result of comparing the above band-shaped lower core in the track width direction and the lower core formed entirely without fluttering, the former has a 5 dB improvement in recording efficiency compared to the latter, and the head chip variation is within the range of 1 dB. Ta.

Furthermore, the manufacturing yield was improved by 50%. Next, a second embodiment of the thin film magnetic head according to the present invention will be described.

In this example, the head configuration is the same as that in the first example, and the lower core was formed using the method shown in Figure 3 (bl). c on the non-magnetic substrate 21
o -N1) - Zr-based amorphous core film 22 with a thickness of 20
After sputtering to a thickness of .mu.m, a mask material 45 was formed and patterned into a strip using thin film technology.Next, polyimide resin 46 was applied to a thickness of 25 .mu.m.

Using a flattening process, the resin 46 and the lower core 22 are
The lower core 22 is embedded in the resin 46 by flattening the surface to a film thickness of 20 μm, and a signal coil, a common bias coil, an interlayer material, and an upper core are formed in the same manner as in the first embodiment to form a thin film magnetic material. Got the head.

FIG. 5 is a sectional view showing a third embodiment of the thin film magnetic head according to the present invention, in which 61 is a non-magnetic substrate, 62 is a lower core, 63 is a signal coil, 64 is a common bias coil,
65 is interlayer material and cap material, 66Fi is upper core,
67 is a protective film and a bonding layer, 68 is a protective plate, and 69 is a core connection portion.

In the same figure, the head configuration of this embodiment is the same as that of the first embodiment, but after sputtering the lower core material onto the flat base 8!61, the core end is taber-etched to form the lower core 62. , then J * next Cocoil 6 to this
564. A thin film magnetic head was obtained by patterning the upper core 66 and the like.

・FIG. 6 is a top view showing a fourth embodiment of the thin-film magnetic head according to the present invention, which is applicable to a two-head electronic camera thin-film magnetic head and has a proportional structure, 71 is a non-magnetic substrate, 7
2 is the lower core, 73 is the coil.

76 is an upper core, and 79 is a core joint.

In the figure, this head has a track width T, = 60μ.
m% A two-track head with a track spacing T, 1 = 40 μm, a lower core 72t is formed under the upper core 76, coil 73, etc. to be long in the track width direction on the substrate 71, and the track sliding part is separated from other parts. Even with such a structure, the magnetic anisotropy is improved and the manufacturing yield is improved.90 Figure 7 shows the lower core of the thin film magnetic head of the example shown in Figure 6. This is a class that shows the relationship between the aspect ratio of the dimensions and the head output, where the horizontal axis is the aspect ratio of the lower core dimension (the horizontal is in the track width direction), and the vertical axis is the head output (dB). It can be seen that good head output can be obtained when the aspect ratio of the lower core dimension is about 2, and even better results can be obtained when it is 5 or more.

〔Effect of the invention〕

As explained above, one advantage of the present invention is that since the axis of easy magnetization is defined by the shape effect, characteristics with less variation can be obtained for each head chip, and the area of the lower core is reduced. Defects such as wire breakage and short circuits due to protrusions from the wiring are reduced, and manufacturing yield can be significantly improved along with the direction of magnetic anisotropy. It is possible to provide a thin film magnetic head of.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a first embodiment of the thin film magnetic head according to the present invention, FIG. 2 is a top view of the lower core material, and FIG.
t, (b) is a process diagram explaining the method of forming the lower core,
4 is a top view of a thin film magnetic head using the lower core formed by the method shown in FIG. 5(a), FIG. 5 is a sectional view showing a third embodiment of the thin film magnetic head according to the present invention, and FIG. The figure is a top view showing a fourth embodiment of the thin film magnetic head according to the present invention.
FIG. 7 is a graph showing the relationship between the lower core dimensions and head output of the thin film magnetic head shown in FIG. 6, and FIG. 8 is a top view of the substrate for explaining the axis of easy magnetization that occurs in the lower core in the prior art. be. 21.61.71...Nonmagnetic substrate, 22,62°7
2...Lower core, 23,63.75...Signal coil. 24.64...Common bias coil, 25.65...
・Interlayer material, 26, 66.76... Upper core, 27.6
7 Purulent material and bonding layer, 28. 68... Protective plate, 29
゜69.79... Core connection portion % 45... Mask material, 46... Resin. A30 11 figures straw 20 f M + lI 24 'Kotaka 3 days. Cumulative 51 1iAG side

Claims (3)

[Claims] (1) Non-magnetic substrate, lower core, interlayer material, conductor coil,
1. A thin film magnetic head comprising at least an upper core and a protection plate, characterized in that the lower core is patterned into a long strip in the track width direction. (2) A thin film magnetic head according to claim (1), characterized in that the lower core is embedded in the substrate or the interlayer material. (3) In the thin film magnetic head according to claim (1), the dimensions of the lower core are set laterally (in the track width direction).
/ A thin film magnetic head characterized by having a structure in which the vertical ratio is 2 or more.