JPH04360006A - Thin film magnetic head - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

FIELD OF INDUSTRIAL APPLICATION The present invention is used in a continuous recording/reproduction type magnetic tape device using a magnetic flux induction type thin film head for recording and a magnetoresistive element for reproduction. The present invention relates to an integrated recording/reproducing thin film magnetic head.

0002

2. Description of the Related Art In recent years, as the recording capacity of magnetic tape devices has increased, magnetic heads are also required to have higher linear recording densities and higher track densities.

[0003] Corresponding to this, the track width,
Thin film magnetic heads, which can control track pitch with high accuracy of ±(1 to 2) mm, have come into use. Particularly in playback heads, magnetoresistive elements (hereinafter referred to as MR elements) are effective because they provide an output that is independent of the speed of the recording medium and are less susceptible to the effects of magnetic flux from the recording head that does not go through the recording medium. It is starting to be used.

Conventional examples of magnetic heads using this technology are shown in FIGS. 5 to 8. This head has a configuration in which three heads are combined from the left in FIG. 5: a playback section 21a, a recording section 22, and a playback section 21b, and each section has four channels (C-1 to C-4). . The first channel (
C-1), the second channel (C-2), and the fourth channel (C-4), two channel information signals are recorded and reproduced, and the remaining one channel is used to record and reproduce a servo signal. . The third channel (C-3) is provided for compatibility with lower models.

As shown in FIG. 6, in the recording head, a lower yoke 24 made of permalloy or amorphous alloy is formed on a non-magnetic substrate 23 by sputtering or plating, and copper, copper, etc. A coil 26 made of aluminum or gold is formed by vapor deposition or plating, and is attached to the lower yoke 2 through an insulating layer.
The upper yoke 27 is made of the same material as 4 and constitutes a magnetic circuit.

As shown in FIG. 7, the reproducing head is constructed by forming an MR element 29 on a ferromagnetic substrate 28 through an insulating layer by vapor deposition, and then forming an MR element 29 on a ferromagnetic substrate 28 through an insulating layer. It has a structure in which a shield portion 30 is bonded.

Next, the principle of operation of this head will be explained based on FIG. First, the magnetic tape 31 runs in the direction of arrow F from the beginning of winding to the end of winding. The recording heads are three heads (C
-1, C-2, C-4) are used. At the same time, two of the three reproducing heads FR on the right gap line GL2 whose track positions are the same as those of the recording head reproduce recorded information, check for errors, and transfer data. The other reproducing head reproduces the servo signal, detects the track position, and feeds back track position deviation information to the stepping motor that controls the vertical movement of the magnetic head.

When the tape reaches the end of its winding, the magnetic head moves by one pitch, and the tape running direction becomes the direction of arrow R. Recording is performed by the two recording heads on the center gap line GL1, and at the same time the left side The three reproducing heads RR on the gap line GL3 reproduce the recording signal and the servo signal.

In this case, the recorded signal is recorded at a recording density of 40 Kfrpi or more, so the tape touch state of the reproducing head is a key factor in whether or not the signal can be reproduced without error. For example, at 40Kfrpi, the recording wavelength is 1.27μm, and the floating height of 0.14μm is 6
This appears as a dB deterioration in signal output.

0010

Problems to be Solved by the Invention Two problems arise in the configuration of such a magnetic head. First of all, 3
One is to obtain the best tape touch on all of the two gap lines, and the other is to precisely match the center of the track of the recording head with the center of the two reproducing heads, FR and RR.

The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a thin-film magnetic head that can easily obtain the best tape touch and has less track deviation between recording and reproduction.

0012

[Means for Solving the Problems] In order to achieve the above object, the thin film magnetic head of the present invention is a recording head in which a plurality of heads, each of which integrates a recording head and a reproducing head, are formed on one substrate using thin film technology. Two multi-channel heads with integrated playback are arranged parallel to the tape running direction.

[0013]

[Function] With the above configuration, the present invention can obtain the best tape touch, and only needs to adjust two gap lines. In addition, adjustment of the deviation in the track direction only requires aligning the centers of the two multichannel heads.

[0014]

[Example] An example of the present invention will be described below with reference to FIGS. 1 to 4.
This will be explained with reference to.

FIG. 1 shows a perspective view of the thin film magnetic head of the present invention. The recording/reproducing head 1a on the left side and the recording/reproducing head 1b on the right side are the same, and are arranged with the ferromagnetic substrate 2 side facing outward. This head records and reproduces data signals and servo signals of the first channel (C-1), second channel (C-2), and fifth channel (C-5) from the upper side. Channel (C-
3) is provided for compatibility with lower-level models, and has a wider track width than the three channels (C-1, C-2, C-5), and is capable of recording and reproducing data with a lower recording density. It is something to do. The fourth channel (C-4) is the first,
These are the same as the second and fifth channels (C-1, C-2, C-5), but are not used for recording or playback here.
It is used as a dummy channel.

FIG. 2 is a detailed perspective view of the integrated recording/reproducing head, and FIG. 3 is a sectional view thereof. A ferromagnetic material made of Mn--Zn ferrite or Ni--Zn ferrite is used as a substrate 2, and an insulating layer 3 made of Al2O3 or SiO2 is formed thereon by sputtering. On top of this, Ni-
A magnetoresistive element 4 made of Fe is formed by a vapor deposition method. As the biasing means, one of the barber pole method, permanent magnet bias method, soft film bias method (SAL), and shunt film bias method is used. Ni-Fe or Co-N is formed on the magnetoresistive element 4 through an insulating layer having the above composition.
A shield film 5 made of b-Zr is formed by sputtering. This ferromagnetic film acts as a shield layer that improves the high frequency characteristics of the magnetoresistive element, and at the same time serves as the lower yoke of the recording head. Furthermore, a coil 6 made of copper, aluminum or gold is formed by plating or vapor deposition with an insulating layer interposed therebetween. After forming an insulating layer on top of this, in order to efficiently form a magnetic circuit, we perform a flattening process to eliminate the level difference between the top and the coil, and diagonal etching to smoothly connect the level difference between the magnetic gap and the top of the coil. , further Ni-Fe or Co
An upper magnetic layer (upper yoke) 7 made of -Nb-Zr is formed. A protective layer 8 made of Al2O3 is formed thereon as shown in FIG. 3, and a protective substrate 9 made of a nonmagnetic material such as Zn-ferrite is bonded.

In a multi-channel system in which a plurality of integrated recording/reproducing heads (five in this embodiment) manufactured in this manner are arranged on the ferromagnetic substrate 2, the head of each channel is compatible with the lower model. The third channel (C-3) is arranged in a symmetrical position with respect to the third channel (C-3) provided for the purpose.

FIG. 4 shows the arrangement of channels. That is, the second channel (C-2) and the fourth channel (C-
4) and the first channel (C-1) and the fifth channel (C-5) are each located at a symmetrical position with respect to the channel (C-3). Further, in the present invention, two multi-channel heads (10a and 10b) are used with the front and back reversed, but each head, that is, each channel is located at a point symmetrical position with respect to the head center 0. That is, in the left multi-channel head 10b, the fourth channel becomes a dummy head, but in the right multi-channel head 10a, the second channel becomes a dummy head. In addition, in FIG. 4, 11 is a magnetic tape.

The operation of the magnetic head of the present invention will be explained based on FIG. 4. When the magnetic tape runs in the direction of arrow F, the magnetic head 10 on the end side of the magnetic tape
The set b acts as a record and records the data signal. At this time, the set of magnetic heads 10a located on the winding start side of the magnetic tape operates as a reproducer, and performs reproduction and transfer of data signals and reproduction and feedback of servo signals. When the magnetic tape reaches the end of winding, it steps by one pitch,
Travel in the direction of arrow R. At this time, the roles of recording and playback are also switched.

[0020]

Effects of the Invention As is clear from the above description, the thin film magnetic head of the present invention uses two multi-channel heads each having a plurality of integrated recording/reproducing heads, and is not assembled into one recording head assembly as in the prior art. Compared to the case where two reproducing head assemblies are used, the same function can be achieved with a simpler structure.

Furthermore, according to this structure, no matter whether the magnetic tape runs in the forward direction (F) or the reverse direction (R),
The upper magnetic layer is on the trailing edge side. As is well known, the recording performance of the head is highly dependent on the magnetic properties of the yoke on this side, so the magnetic layer on this side is made of amorphous material such as Co-Nb-Zr or highly saturated film such as Sendust film. This means that it can be constructed from a high-performance material with high magnetic velocity density, and in that case, a cost reduction effect can also be expected.

[0022] Furthermore, when the magnetic resistance runs in the forward direction and when it runs in the opposite direction, it is only necessary to switch the role of the recording/reproducing integrated head, and the optimum tape touch on the two gap lines can be achieved. All you have to do is realize it (conventionally, there are three gap lines). Also, regarding the track center deviation of the recording/reproducing head, only one adjustment is required to align the centers of the channels of the left and right heads, making it possible to realize a head that is much easier to manufacture.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a thin film magnetic head according to the present invention.

[Figure 2
] Perspective view of integrated recording/reproducing head part

[Figure 3] Cross-sectional view of the head part

[Fig. 4] Channel arrangement diagram of the thin-film magnetic head according to the present invention

[Figure 5] Perspective view of a conventional thin film magnetic head

[Fig. 6] Perspective view of a conventional recording head portion

[Fig. 7] Perspective view of a conventional playback head part

[Figure 8] Channel layout diagram of a conventional thin-film magnetic head

[Explanation of symbols]

1a, 1b Recording/playback head 2 Ferromagnetic substrate 3 Insulating layer 4 Magnetoresistive element 5 Shield film (shield layer) 6 Coil 7 Upper yoke

Claims (2)

[Claims] 1. A reproducing head in which a magnetoresistive element is arranged on a ferromagnetic substrate with an insulating layer interposed therebetween, and a shield consisting of a ferromagnetic thin film serving as the lower yoke of the recording head with an insulating layer placed above the reproducing head. A recording head was constructed by placing a coil embedded in an insulating layer on top of the upper yoke, which was formed so that the longitudinal center of the magnetoresistive element coincided with the center of the upper yoke. A multi-channel head comprising at least one channel or more of an integrated recording/reproducing head on the ferromagnetic substrate is spaced apart at a certain interval parallel to the running direction of the recording medium so that the centers of each channel coincide. Two thin film magnetic heads arranged. 2. The arrangement of each recording/reproducing integrated head of the multi-channel head is symmetrical with respect to the central recording/reproducing integrated head or the center of the pitch of the central recording/reproducing integrated head. Thin film magnetic head.