JPS63261511A - Thin film magnetic head - Google Patents

Abstract

PURPOSE:To shorten the magnetic path length and to improve the reproducing efficiency by providing a Hall element between the upper and lower cores forming a magnetic core and performing the recording and reproducing jobs by means of a coil and the Hall element respectively. CONSTITUTION:A gap 7, a lower core 1a, a Hall element 6 and an upper core 1b are set around a coil 2 for production of a magnetic circuit of a magnetic head. At the same time, five electrodes, i.e., a bias electrode 3, the output electrodes 4 and 4, and the earth electrodes 5 and 5 are provided around the element 6. In other words, a recording action is carried out by a coil of a single or several turns and a reproducing action is carried out by a Hall element. Thus, it is possible to decrease the number of turns of a coil and therefore to shorten the magnetic path length.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a magnetic head suitable for use in magnetic recording and reproducing devices such as VTR video floppies, and particularly relates to a thin film magnetic head that does not deteriorate in characteristics even in a high frequency band. Regarding the head.

[Conventional technology]

As the recording density of VTRs and video floppy magnetic recording and reproducing devices improves, their magnetic heads are also progressing toward narrower tracks and shorter wavelength recording. For this reason, in order to increase the reproduction efficiency and improve the frequency characteristics of the magnetic head, the magnetic path length is shortened to increase the reproduction efficiency, and a multilayer thin film is formed by sputtering, vapor deposition, etc. Thin-film magnetic heads using C as the core material have been proposed.However, in most of these thin-film magnetic heads, the coils are patterned to shorten the magnetic path length, In this case, the coil must have a single-layer or multi-layer structure and must be rotated between the cores with more than 10 turns, which has reached the limit of shortening the magnetic path length. Furthermore, if the coil is made long, DC resistance becomes a problem, and a sufficient improvement in regeneration efficiency cannot be expected, and the use of multiple layers or multiple turns of the coil causes a decrease in yield in the manufacturing process.

An example of this thin film magnetic head is the one described in Japanese Unexamined Patent Publication No. 59-227025.

[Problem that the invention seeks to solve]

In the above-mentioned conventional technology, the shortening of the magnetic path length has already reached its limit, and there is no way to improve the regeneration efficiency any further.

An object of the present invention is to further shorten the magnetic path length, improve reproduction efficiency, and provide a thin film magnetic head with good frequency characteristics.

[Means for solving problems]

The above object is achieved by using a common magnetic core and performing recording and reproduction using different methods.

That is, recording is performed using a coil of one turn or several turns, and reproduction is performed using a Hall element.

This makes it possible to reduce the number of turns in the coil, which is an obstacle to shortening the magnetic path length.

To solve the problem of leading out the terminals with Hall elements, we changed the conventional cross-shaped lead out and created a structure in which there are no Hall element terminals on the side that forms the magnetic path.

Therefore, the magnetic path does not become long due to the lead-out terminal of the Hall element. Furthermore, there may be four or more terminals. In addition, the Hall element can be formed to a thickness of several thousand squares using thin film patterning technology, and the multi-output voltage can be increased.The output voltage of the Hall element is expressed by the following equation.

R.B.I.

V, = - ■u: Output voltage R3: Hall coefficient 1, : Bias current d: As is clear from the Hall element jump equation, the Hall output voltage increases as the Hall element thickness d becomes thinner.

[Effect]

In the prior art, since recording and reproduction are performed using the same coil, the number of turns of the coil must be increased in order to obtain the reproduction output. Therefore, it is difficult to shorten the magnetic path length, and the reproduction efficiency cannot be improved.

In the present invention, since reproduction is performed using a Hall element using thin film patterning technology, the number of turns of the coil may be one to several turns, which is sufficient for recording, and the length of the magnetic path can be significantly shortened. Furthermore, since the Hall element is formed using thin film patterning technology, the element can be formed extremely thin and in an optimal shape, resulting in a large reproduction output. Further, the head manufacturing process is also facilitated.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.0 FIG. 1 is a perspective view showing an embodiment of the thin film magnetic head according to the present invention, and FIG. 2 is a plane A-B-C-D of FIG. 1. 1 is a cross-sectional view taken at , where 1 is a substrate, la is a lower core, 1t) is an upper core, 2 is a coil, 3 is a bias electrode, 4 is an output electrode, and 5
is a ground electrode, 6 is a Hall element, and 7 is a gap. The magnetic circuit of the magnetic head is configured by this. In addition, there are five electrodes (
Bias electrode 3, output electrode 4.4, ground electrode 5.5)
is located. The thickness of this Hall element and electrode is
It's about a few thousand X at most. In conventional Hall elements, there are usually four electrodes in a cross pattern, but in the magnetic head according to the present invention, the ground electrode is divided into two locations as shown in the figure in order to shorten the magnetic path length as much as possible. Moreover, the electrodes are not drawn out on the magnetic path side.

FIG. 3 shows a second embodiment of the magnetic head according to the present invention.
2 is a sectional view similar to the figure, and the same reference numerals as in FIG. 2 correspond to the same components. The embodiment shown in the figure is an example of a type of magnetic head in which a large number of Hall elements are arranged. This type of magnetic head has a large number of Hall elements, and the shape of the elements is optimized by patterning technology, so the reproduction output is large. In this head as well, no electrodes are drawn out on the magnetic path side.

In both of the thin film magnetic heads of the above two embodiments, the magnetic caps are formed parallel to the substrate, but the present invention is not limited to this, and the magnetic gap may be formed non-parallel to the substrate.

FIG. 4 is a perspective view of still another embodiment of the thin film magnetic head according to the present invention, showing an example in which the magnetic gap is formed at an angle with respect to the substrate.

The magnetic head shown in the figure is similar to the embodiments described above, except that the lower core 1a and the upper core 1b are formed on a common plane on the substrate 1 at the gap 7.

FIG. 5 is a process diagram illustrating the manufacturing process of the thin film magnetic head shown in FIGS. 1 and 2, and FIG.

The same reference numerals as in FIG. 2 correspond to the same constituent parts, 8 is a protective film, and 9 is an insulating film.

In the figure, in step (a), a film of a soft magnetic material such as amorphous or sendust is formed on the substrate 10 by vapor deposition, sputtering, etc., and is embedded to form the lower core 1a.
form.

In step (1)), a Hall element 6, an electrode 5. 4. 5 is formed by vapor deposition, sputtering, etc., and patterned by photolithography. The material of the Hall element is sSi+In5bIIn
It is A8, etc., and is several thousand times thicker. In addition, the electrode material is A
T, Cu, etc. are used.

In step (c), the patterned Hall element 6,
After forming an insulating film (not shown) such as the upper surface K 5102 of the electrode, the recording coil 2 is formed by vapor deposition or sputtering and patterning.

In step (d), an insulating film 9 such as KS10z is formed on a part of the upper part of the coil 2, and a gap material (not shown) is formed on the front end of the lower core 1a by vapor deposition or the like.

In Step 8 (8), a film of a soft magnetic material such as amorphous or sendust is formed on the portion including the Hall element 6, the insulating film 9, and the gap portion by vapor deposition, sputtering, or the like.

In step (f), the soft magnetic film is patterned to form the upper core 1b.

In step -), an i-holding film 8 is formed on the upper core 1b.

Through the above steps, the thin film magnetic head shown in FIGS. 1 and 2 can be manufactured.

〔Effect of the invention〕

As explained above, according to the present invention, since recording is performed with a coil of one to several turns and reproduction is performed with a Hall element, the magnetic path length can be significantly shortened and the reproduction efficiency can be greatly improved. A thin film magnetic head with improved frequency characteristics can be provided.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of the thin film magnetic head according to the present invention, FIG. 2 is a cross-sectional view taken along plane A-B-C-D in FIG. 1, and FIG. 3 is a thin-film magnetic head according to the present invention. A sectional view similar to FIG. 2 showing another embodiment of the head, FIG. 4 a perspective view showing still another embodiment of the thin film magnetic head according to the present invention, and FIG. 5 showing manufacturing of the thin film magnetic head according to the present invention. It is a process diagram explaining a process. DESCRIPTION OF SYMBOLS 1... Substrate, 1a... Lower core, 1b... Upper core, 2... Coil, 3... Bias electrode, 4...
Output electrode, 5... Earth electrode, 6... Hall element,
7...Gap, 8...ApA, 9...Insulating film.

Claims (1)

[Claims] 1. In a thin film magnetic head formed by forming and patterning magnetic head constituent materials such as a magnetic core, a coil, and an insulating film on a substrate, between an upper core and a lower core constituting the magnetic core. 1. A thin film magnetic head comprising a Hall element and an electrode of the Hall element, the coil being used for recording, and the Hall element for reproduction. 2. A thin film magnetic head according to claim 1, wherein the electrode of the Hall element is provided at a position that does not affect the length of the magnetic path of the magnetic core.