JPS59227023A - Hall effect type thin film magnetic head - Google Patents

Abstract

PURPOSE:To simplify a structure, and also to reduce a distortion of a reproducing waveform by providing an output terminal at a right angle with a bias current direction of a Hall effect element, applying a magnetic flux vertically to the element suface, connecting in common one end of a bias terminal, providing a connecting wire linked with a core, and using a gap in common at the time of recording and reproducing. CONSTITUTION:2, 1, ai and bi, ci and di, (d) and d', and 4 denote a ferrite substrate used as the first core, too, a Hall effect element film for each head of N pieces, N pairs of output terminals, N pieces of bias current terminals, its common terminals, and a connecting wire, respectively. The substrate 2 and the second cores 3 of N pieces form N pieces of head cores having a gap (g), a magnetic flux corresponding to a signal magnetic field is led into the core, and the magnetic flux passes through the Hall effect element film and is shunted. That is to say, a magnetic flux density is applied vertically to the Hall effect element film, and signal voltage corresponding to N pieces of tracks is generated in the terminals ai, bi. In case of recording, a high frequency voltage for bias is applied between the terminals (d), d', and a bias magnetic field is generated in the gap (g). The signal magnetic field applies a signal current to a winding 5 formed on N pieces of core parts. In this regard, a reproducing output is in proportion to a Hall coefficient, a bias current and a magnetic flux density, in inverse proportion to a film thickness, and does not contain the secondary higher harmonic distortion.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of a multi-track thin film head using Hall effect elements.

In recent years, multi-track thin film heads have been developed for use in digital audio tape devices.

In these devices, an induct tape type thin film head is used as a recording head, and a magnetoresistive head (hereinafter referred to as MR head), which can obtain a large output regardless of the tape speed, is used as a reproducing head.

In this way, conventional heads are so-called combination heads that integrate independent recording inductive heads and playback MR heads, so the parallelism of the gaps between the respective heads and good contact between the tape and the head are ensured. Also, it was difficult to ensure the mutual position of the trucks, resulting in a complex structure and poor productivity. Furthermore, due to the reproduction principle of the MR head, second-order harmonic distortion exists in the reproduced waveform, which has been an obstacle to achieving high-density recording and reproduction.

The present invention has been made to eliminate the drawbacks of the conventional devices as described above, and in a thin film magnetic head device in which a plurality of magnetic heads are configured on a substrate, a magnetic head device for each head formed on the substrate or a substrate is provided. A first core, each head Hall effect element provided on the first core, each head phase current terminal provided at both ends of each Hall effect element in one direction, and a direction perpendicular to the one direction of each Hall effect element. Voltage terminals for each head are provided at both ends of the direction, and one end is provided on each of the Hall effect elements so that magnetic flux is generated in a direction perpendicular to the one direction and a direction perpendicular to this direction. a second core for each head which forms a magnetic gap between each core and the first core, a winding for each head linked to each core, one of the current terminals of each head is connected to each other to form a common terminal, and each The integrated head structure is equipped with a connection line that links with the core of the head, and the head gap can be shared for recording and playback, allowing for high-density recording with simple structure and assembly and low distortion of the playback waveform. - The purpose is to provide a Hall effect type thin film magnetic head suitable for reproduction.

First, the operation of the Hall effect element according to the present invention will be explained. In FIG. 1, (1) is a thin film element having a Hall effect, such as an In13b semiconductor formed to a thickness of about 1 μm. (c) and (d) are the bias current terminals of the device.

(1) shows the bias current, (a) and (b) show the output terminals, and (B) shows the magnetic flux density according to the signal applied perpendicularly to the element surface. Now, if the element thickness is δ, the output voltage S is expressed by E3=RH-r@B/δ...+11 formula. RH is called the Hall coefficient and is equal to 1/ne.

Here, e represents the electrical quantity of electrons, and n represents the concentration of carrier electrons. As seen in equation (1), the output voltage of the Hall element has no second harmonic distortion compared to the signal magnetic flux density B, and
It can be seen that it does not depend on tape speed.

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

In FIG. 2, (2) is a ferrite substrate that also serves as the first core, (1) is an N1-based Hall effect element film for each head formed on this, (al), (b+), --(ay
t), (bN) are N pairs of voltage terminals for each head connected to each element, (c, ), (dl), ...
-(cN), (dN) are N connected to each element
(d) with current terminals for each head.

(d) is the common terminal of (dl)...(dN) (
4) are each terminal (d,), ... (dN)
, θ), (ci), and (a).

The symbols (b), (c), and (d) correspond to the principle diagram in FIG. 1, respectively. (3) has a gap (g) between it and the first core (2) on the surface facing the medium, and the second core shunts with the ferrite substrate (2) on the Hall effect element film (1).
The core is obtained by patterning a permalloy thin film or the like.

(5) is a winding linking the first core (2) and each second core (3). Also, between the second core shunt part and the Hall effect element film (11), the winding (5) and each terminal conductor (al), (b, )---(aN), (b
Although an insulating layer film is required between the NNAs 3, it is omitted in the figure. There are other film forming steps such as gap spacer films that are necessary in the actual thin film head process, but to avoid complication, only the parts necessary for detailed explanation of the present invention are illustrated. Further, in order to facilitate understanding of the structure, the second core (3) corresponding to the Nth element is omitted.

First, the reproducing process of the head according to this embodiment will be explained. N bias current terminals (cl), (c2).

...(cN) and common bias current terminal (d), (a
) between.

Apply DC voltage and apply the insulated aluminum to each element. Ferrite substrate (2) and N second cores (3)
forms N herad cores with a gap (g),
Magnetic flux corresponding to a signal magnetic field from a medium such as a tape is guided into the core, and these fluxes shunt through the Hall effect element membrane. That is, a magnetic flux density B corresponding to the signal is applied perpendicularly to the Hall effect element film, and the output voltage terminal (
al), (bl), ... (aN).

(bN), a signal voltage corresponding to each of the N tracks is generated.

Next, when this embodiment head is used as a recording head, a high frequency voltage for recording current bias is applied between terminals (d) and (A) to generate a recording current bias magnetic field in the head gap (g).

Furthermore, the signal magnetic field superimposed on this bias recording magnetic field is
This is achieved by applying a signal current to the windings (5) formed in each of the N core parts.

The recording signal winding consists of terminal conductors (a), (b), (e
), (d) can be formed on the coil with an insulating layer interposed therebetween, and can be a one-turn coil, a plurality of spiral coils, or a laminated coil.

Note that in the above embodiment, a ferrite substrate (2) is used.

The structure was such that this substrate also served as the first core, but a non-magnetic substrate made of ceramic glass, sapphire, etc. was used, and the first core made of a magnetic thin film of permalloy, sendust, etc. was formed on top of this. Even if elements having the above configuration are stacked, the same effects as in the above embodiment can be obtained.

As described above, according to the present invention, in a thin film magnetic head device comprising a plurality of magnetic heads on a substrate, a first core for each head formed on the substrate or a first
A Hall effect element for each head provided on the core, a current terminal for each head provided at both ends of each Hall effect element in one direction, and a current terminal for each head provided at both ends of each Hall effect element in a direction perpendicular to the one direction. Voltage terminal for each head.

One end is provided on each of the ball effect elements, and a magnetic gap is formed between the other end and the first core so that magnetic flux is generated in a direction perpendicular to the one direction and a direction perpendicular to the one direction. A second core for each head forming a second core, a winding for each head linked to each core, one of the current terminals of each head connected to each other to form a common terminal, and a connecting wire linked to the core of each head. Since the bias current application terminal of the Hall effect element is common and has a structure that passes through N cores, it can be used as a bias application conductor of the Hall effect element during reproduction, and it can also be used as a recording bias conductor during recording. It can also be used as a coil for applying a magnetic field.

Since N head gaps can be shared as recording gaps and reproduction gaps, a Hall effect thin film magnetic head with a simple head configuration and free of second harmonic distortion suitable for high-density recording and reproduction can be obtained. There is.

[Brief explanation of the drawing]

Fig. 1 is a diagram of the operating principle of a Hall effect element according to the present invention, and Fig. 2 is a perspective view showing an embodiment of the present invention, in which +11 is a Hall effect element film, (2) is a ferrite substrate that also serves as a first core, (3) is a second core made of a thin film magnetic material, (a
l), (b, ), -=-(aN), (bN) dN pairs of voltage terminals, (cl), ""-' (eN) are N current terminals, (a), (a) are The common current terminal (5) is a winding. In Figure 9, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] In a thin film magnetic head device comprising a plurality of magnetic heads on a substrate, the substrate or a first core for each head formed on the substrate, and a first core for each head provided on the first core, respectively. A Hall effect element, each head phase current terminal provided at both ends of each Hall effect element in one direction, each head pressure terminal provided at both ends of each Hall effect element in a direction perpendicular to the one direction, each of the above One end portion is provided on each of the Hall effect elements so that magnetic flux is generated in a direction perpendicular to the direction and a direction perpendicular to the direction. A second core for each head forming a magnetic gap between the other end and the first core, a winding for each head linked to each core, and a common terminal by connecting one of the current terminals of each head to each other. and a Hall effect thin film magnetic field with connecting wires linking the core of each head.