JPS60160010A - Thin film magnetic head - Google Patents

Abstract

PURPOSE:To improve the efficiency of a core by using a bulk magnetic material in forming an upper magnetic core which is previously formed of a thin film. CONSTITUTION:A thin film coil 14 is formed via an insulator 12 on the 1st magnetic core 11 which is a magnetic substrate and magnetic materials 17, 18 are provided in such a way that the parts corresponding to a front gap part 16 of the gap formed of the insulator 12 and back gap part 13 are made higher than the height on top of the coil 14. An upper magnetic core consisting of a bulk magnetic material 10 joined to the materials 17, 19 so as to face the same in the parts corresponding to the front gap part 16 and the back gap part 13 is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a thin film magnetic head used, for example, in digital audio recording.

[Technical background of the invention and its problems] In recent years, higher density magnetic recording has been pursued. by the way,
When the coercive force of the magnetic recording medium exceeds 1oooo=,
In order to magnetize this recording medium, a recording current on the order of IAT and a magnetic head material with a high saturation magnetic flux density are required. Furthermore, if a digital audio signal is to be recorded on, for example, a current compact cassette tape, the track pitch must be reduced to about 100 μm. Therefore, the conventional method of stacking bulkheads has become impossible. For this reason, a head in which a magnetic core (2) and a coil (3) are formed as thin films on a magnetic substrate (υ) as shown in Fig. 1 is attracting attention. A magnetic gap is formed between the two.

However, as mentioned above, a thick coil that can flow a large current and a magnetic core that is thick enough not to saturate are required. Regarding the coil, it is possible to process it into a predetermined shape due to advances in dry etching technology, but as shown in Figure 1, the magnetic core (upper magnetic core) (2) has a step (5), ( 6) It is necessary to form it in a certain part. Normally, the upper magnetic core is formed using methods such as vacuum evaporation, sandbatter, and plating. Therefore, if vacuum evaporation or sputtering is used, the step part (
In order to prevent magnetic saturation of (5) and (61) in FIG. 1, it is necessary to form a magnetic film with a thickness of at least about 7 μm. In this case, many overetches occur when forming a track with a predetermined width, resulting in poor accuracy and deterioration of magnetic properties at stepped portions, resulting in a decrease in core efficiency. Furthermore, if plating is used, it will adhere to flat parts and stepped parts, but it is difficult to control the composition and the adhesion is poor. Also, in practice, only permalloy can be plated.

After forming the upper core (2), a holder (not shown) is attached.
However, none of the above methods can eliminate the stepped portion. In addition, in order to eliminate the tape sliding part of the upper magnetic core (2) (the adhesive layer at the stepped part of the upper magnetic core (2) is thicker and the adhesive layer is thicker, the durability deteriorates and the space loss increases. Possible methods include forming the magnetic core in two steps, or forming a thick protective film and then flattening it, but in this case, there are problems in that the process becomes complicated and reliability is poor.

[Object of the Invention] The present invention has been made in consideration of the above-mentioned point K, and an object of the present invention is to provide a thin film magnetic head that can increase core efficiency and does not require a conventional holder.

[Summary of the Invention] The present invention includes a thin film coil formed on a first magnetic core with an insulator interposed therebetween, and a thin film coil formed on the first magnetic core and the insulator, and a gap formed by the insulator. A magnetic body whose portions corresponding to the front gap portion and the pack gap portion are higher than the top surface height of the thin film coil is bonded to the magnetic body facing each other at portions corresponding to the front gap portion and the pack gap portion. By including a second core made of bulk magnetic material, the deterioration of the magnetic properties of the second core at the stepped portion is completely eliminated and the core efficiency is increased. It is.

[Embodiment of the Invention] An embodiment of a thin film magnetic head according to the present invention will be described below with reference to the drawings.

FIGS. 2 to 5 are diagrams showing the manufacturing process of the thin film magnetic head of the above embodiment.

First, as shown in Fig. 2, a magnetic substrate α1 such as ferrite is used.
) (on the first magnetic core and the lower magnetic core), a film α such as 8i02 that serves both as a magnetic gap and an insulating film is formed.
2 is formed by a method such as vapor deposition or sputtering, and the pack gap portion (13) is opened. Next, AA!, Au.

・A non-magnetic conductive film α made of Cu or the like is formed by a method such as vapor deposition sputtering and etched into a coil shape as shown in the figure.
As shown in the figure, in order to electrically insulate the coil-shaped conductive film a4) and the upper magnetic core (which is made of bulk magnetic material and becomes the second magnetic core, as described later), The film +151 is formed of an oxide or an organic insulator such as polyimide by sputtering, vapor deposition, or the like.

Furthermore, as shown in the cross-sectional view of FIG. 4(a), a magnetic film a? ), alpha oxide is formed by vapor deposition, sputtering, etc. At this time, the magnetic film (1'6.α barrel is the coil (14) and the insulating film (
L! Overlapping means that the thickness is slightly larger than 9. The magnetic films αη, α♂ are formed by the magnetic core (
Since it does not need to be thick as in 7), etching is also relatively easy. Note that FIG. 4(b) is a senryo map corresponding to FIG. 4(a).

Finally, the bulk magnetic material α is bonded with an adhesive (a) or the like so that it is in contact with the magnetic film aη and the frame A without any gaps. Since this magnetic material Al also serves as a holder used in a normal thin film head, the head sliding surface can be formed by processing it into a figure 8 shape as shown in the figure.

By the way, it is easy to apply the present invention to multi-heads. In that case, in order to prevent crosstalk between channels, the upper magnetic core should be made of magnetic material (as shown in Figure 6).
2) and a non-magnetic material are alternately laminated to have a predetermined track width and track pitch, and placed at a predetermined position on a multi-channel patterned substrate similar to that shown in FIG. Just glue it on. Furthermore, crosstalk can be further prevented by using a laminate-like substrate shown in FIG. 6 for the substrate aη, which is the lower magnetic core.

[Effects of the Invention] As described above, according to the present invention, the efficiency of the core can be improved by forming the upper magnetic core, which was conventionally formed of a thin film, from a bulk magnetic material. is not necessary, and magnetic materials such as amorphous, which could not be used conventionally, can also be used as the core material.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a conventional thin film head, FIGS. 2 to 5 are diagrams showing the manufacturing process of an embodiment of the thin film magnetic head according to the present invention, and FIG. 6 is a perspective view showing a conventional thin film magnetic head. FIG. 3 is a perspective view showing an upper magnetic core when applied to a multi-head. DESCRIPTION OF SYMBOLS 11... Magnetic substrate, 12... Film, 13... Pack gap part, 14... Coil, 17, 18
...magnetic film, W...magnetic material. Agent Patent attorney Kensuke Chika (and 1 other person) Figure 1
. Figure 2 Figure 3 Figure 4rI! 1 (0) Figure 5 Figure 6

Claims (1)

[Claims] A thin film coil formed on a first magnetic core via an insulator, and a front gap portion and a pack gap portion of a gap formed on the first magnetic core and the insulator, and formed by the insulator. A magnetic body whose corresponding portion is higher than the top surface height of the thin film coil, and a bulk magnetic body which is bonded to the magnetic body facing each other at portions corresponding to the front gap portion and the pack gap portion. A thin film magnetic head comprising a second core.