JPS597129B2 - Multi-element thin film magnetic head assembly - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic head that performs magnetic information processing on a magnetic recording medium such as a magnetic tape, and particularly relates to a multi-element thin film magnetic head assembly provided with a plurality of thin film magnetic heads. It is.

Since thin-film magnetic heads can be extremely miniaturized, high-density magnetic information processing is possible, and their use is attracting attention.

FIG. 1 shows an example of a thin film magnetic head.

FIG. 1 is a partially sectional perspective view showing two thin film magnetic heads 1 arranged on a substrate 2. As shown in FIG. This thin film magnetic head 1 includes a lower magnetic film 3, SiO2, etc. on a substrate 2 made of glass or the like.
A lower insulating film 4 made of Al2O3 or the like, a conductor film 5 made of Au, Cu, etc., an upper insulating layer 6 made of the same material as the lower insulating film 3, and an upper magnetic film T are sequentially laminated. Lead 8 is derived. The head portion (front portion) 9 of this thin film magnetic head 1 performs magnetic information processing on a magnetic recording medium. In order to perform higher density magnetic information processing using the thin film magnetic head 1, a multi-element thin film magnetic head assembly as shown in FIG. 2A has been proposed.

In this case, thin film magnetic heads 1 are provided on both sides of a flat substrate 10 whose front and back surfaces are parallel.

That is, thin film magnetic heads IA (IA, 1A2, 1A2,
......1Ai-4, 1Ai, 1Aif,...
・・・・■This thin film magnetic head is hereinafter referred to as an A-side head), and a thin film magnetic head IB is placed on the other surface of the parallel plane substrate (B-slde) at the same pitch P.
(IBI, 1B2, 1Bi-, 1Bi,
・・・・・・：Hereinafter, this thin film magnetic head will be referred to as B-Side.
(called a head). At this time, the A-side heads 1Ai-1, 1A1, 1A1+1 and the B-side heads 1B11, 1Bi are arranged so as to be different from each other. By the way, in this multi-element thin film magnetic head assembly, in order to prevent crosstalk between adjacent tracks (for example, heads 1Bi-1 and 1B1 for head 1Ai), track width w and head pitch P are set such that W<P-W. It is necessary to design it so that

Figure 2B shows each thin film magnetic head element (1A, -1, 1B,
-, 1A1, 1Bi, 1B1,), the positional relationship between the magnetization trap 11 and the guard band 12 is shown. A guard band 12 with .

This guard band 12 is necessary for high-density information processing.
is a loss, but if the guard band 12 is made small, tracking problems occur during writing and reproduction, and crosstalk increases, so it is difficult to make the guard band 12 unnecessarily small. The relationship between this guard band 12 and crosstalk will be explained below.

FIG. 3 is a diagram schematically showing the relationship between the magnetization tracks and guard bands of the A-side head 1Ai and the heads in its vicinity. The reproduction signal SG of the magnetic head 1Ai is as follows.

Where, w: magnetization track width, l: reproduction 2π head width,
UX) 2H.

COSTX: component of the magnetic field perpendicular to the tape from the magnetization pattern in the reproducing head, λ: recording wavelength, D: l-
w1 guard band width (both sides), C,: noise other than losstalk) guard band, i.e., if there is a no-signal part, crosstalk signals from adjacent tracks BL-1, Bi,
UHBi-1(X) and 1HB1(X) become 0, and the reproduction signal of the magnetic head 2'1Ai decreases to.

However, if the guard band 12 is removed, noise from the adjacent tracks will be picked up.

In view of the above problems, the present invention provides A-Slde heads 1A1, 1A2, . . . 1A1-1, 1Ai, 1 of the substrate 2.
Ai+1,... and B-s! De head 1B! ，
1B2,...1Bi-1,1Bi...
The crosstalk signal is attenuated by the azimuth loss caused by the intersection angle θ between adjacent tracks.

First, I will briefly explain azimuth loss.

In FIG. 4, if the magnetization pattern written on the magnetic tape 13 and the reproducing head 14 are parallel, an output signal S is generated. Hato becomes.

(However, W: Trap width, l: Trap to play, Hx=HO
COS Y7X: component of the magnetic field perpendicular to the tape from the magnetization pattern, λ: recording wavelength) Average magnetic field strength received by the effective part of the read head 14 when the angle between the magnetization pattern and the read head 14 is θ [Rad] next to playback head 1
The coefficient A becomes smaller by the angle θ at which 4 becomes the magnetization pattern.

The reproduced signal at that time is as follows, and the loss La due to azimuth loss is expressed in DB units as follows.

FIG. 5 shows the relationship between the inclination angle θ between the magnetization pattern and the reproducing head 13 and the azimuth loss La based on equation (2).

(However, W = 100 [μm]・λ210 [μm]) By the way, in the above equation (1), the crosstalk noise is DDHB
l -1+-HBi, but if the 9191A-Side head and B-Slde head are arranged at an angle of θ to each other, the B-Side head will be
The crosstalk noise from the i-, , Bi tracks is attenuated to 15-cm by the azimuth loss shown in FIG. 5, for example, according to equation (2).

As is clear from Figure 6, the A-Slde head and the B-S
By appropriately selecting the angle formed with the lde head, it is possible to attenuate crosstalk noise by several + DB.

The present invention will be explained below along with an embodiment of the present invention shown in FIG.

In this embodiment, thin film magnetic heads 1 are arranged on both the front and back surfaces of a substrate 15 having different thicknesses in the width direction Z of the magnetic recording medium (direction perpendicular to the traveling direction X of the magnetic recording medium).

This substrate may be triangular prism-shaped with an apex angle θ, or trapezoid-shaped except for the vicinity of the apex. A-Side head 1A1
, 1A2..., 1A1... and the B-Slde heads 1B,, 1B2..., 1B1... are arranged so as to form an angle θ, respectively. The reproduction signal of the overlapping portion 16 of both side heads shown in FIG. B is reduced by the gamma dimensional loss. As shown in FIG. 7, there may be almost no overlapping portions.

The substrate is provided with sawtooth-shaped steps, and a thin film magnetic head is placed on each step.

FIG. 8 shows an A-Side head Al, A-side head on one side of a substrate 16 formed into a stepped shape with an angle of θ between one side and the other side.
2,... Ai,... on the other side B-S
ide head Bl, B2...Bi,...
・The heads on each side are arranged alternately. In FIG. 9, a thin film magnetic head is disposed at each step of a single substrate in which step portions are provided alternately on both sides of the substrate, making an angle θ with the step portion on the other side.

FIG. 10 is a diagram showing still another embodiment of the present invention.
SideI:. The angle formed by each B-Side thin film magnetic head is changed.

As is clear from the second equation, the azimuth loss is the recording wavelength λ
Its size changes depending on the Therefore, the recording wavelength λ is divided into an appropriate number of wavelengths, λ1, λ2, etc., and the crossing angle θλ1 is set so that the azimuth loss works effectively for each wavelength.
, θλ2 . Since it is difficult to vary the crossing angle of thin-film magnetic heads, if the recording wavelength λ is divided appropriately according to the crossing angle of each thin-film magnetic head, azimuth loss can always be used effectively and crosstalk can be reduced. can be done. Furthermore, if the recorded information is a signal in a relatively narrow wavelength band, the fifth
If the thin film magnetic head is mounted at an angle such that the azimuth loss is at its maximum (the valley in the diagram) in the graph shown in the figure, it becomes possible to reduce the effects of crosstalk even more effectively.

As described above, according to the present invention, in a multi-element thin film magnetic head assembly in which a plurality of thin film magnetic head elements are formed alternately on both the front and back surfaces of a substrate at predetermined intervals, the thin film magnetic head elements are installed adjacent to each other. Since the angular difference is tilted by a predetermined angle, it is possible to effectively utilize azimuth loss to reduce crosstalk between adjacent thin film magnetic head elements.

Therefore, high-density information processing can be performed effectively. Furthermore, the present invention achieves the inclination of the thin film magnetic head element by employing a very unique structure in which the thickness of the element mounting substrate is changed, and by employing this, manufacturing for forming the element inclination is possible. can be easily done.

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional perspective view of a thin film magnetic head used in the present invention, and FIG. Figure B), Figure 3 is a diagram explaining crosstalk, Figure 4 is a diagram explaining azimuth loss, Figure 5 is a diagram showing the relationship between tilt angle and azimuth loss, and Figure 6 is a diagram showing one embodiment of the present invention. A schematic diagram (FIG. 6A) showing the relationship between magnetization tracks (FIG. 6B), and a schematic diagram (FIG. 7A) showing another embodiment of the present invention and its magnetization A diagram showing the relationship between tracks (FIG. 7B) and FIGS. 8 to 10 are schematic diagrams showing still other embodiments of the present invention. 1...Thin film magnetic head, 1A...A-
Side thin film magnetic head, 1B...B-Sl
thin film magnetic head of de, 15-18...Substrate.

Claims (1)

[Scope of Claims] 1. In a multi-element thin film magnetic head assembly in which a plurality of thin film magnetic head elements are formed alternately at predetermined intervals on both the front and back surfaces of a substrate, the thickness of the substrate is equal to the thickness of the plural thin film magnetic heads. 1. A multi-element thin-film magnetic head assembly, characterized in that the direction of arrangement of the elements is changed, and thin-film magnetic head elements adjacent to each other, which are alternately formed on the front and back surfaces of the substrate, are tilted by a predetermined angle. 2 When the installation angle difference between the thin-film magnetic head elements adjacent to each other is θ, there are ▲mathematical formulas, chemical formulas, tables, etc.▼ (However, W: magnetization track width by the thin-film magnetic head,
The above θ is set so that the value of λ (magnetic information processing wavelength) is minimal.
2. A multi-element thin film magnetic head assembly according to claim 1, wherein a value of . 3. A multi-element thin film magnetic head according to claim 1, characterized in that the installation angle difference between the mutually adjacent thin film magnetic head elements is changed according to the wavelength of the recording signal recorded on each recording track. assembly.