JPS59117726A - Thin film magnetic head - Google Patents

Abstract

PURPOSE:To attain miniaturization and high performance by laminating the 1st, 2nd and 3rd magnetic layers on one board and forming the 1st and 2nd gap layers and a coil layer different in number of turns and cross sectional area. CONSTITUTION:In the magnetic head, the 1st, 2nd and 3rd magnetic layers 12A, 12B and 12C are laminated on one board 1 to form the 1st and 2nd gap layers having respectively gaps S1, S2 and core width l1, l2 and coil layers 15A, 15B different in number of turns and cross sectional areas. In recording, the 1st gap layer 13A is used and in reproduction, the 2nd gap layer 13B is used. Thus, the number of turns of the coil is set with the optimum condition depending individually on the recording and reproduction, and moreover, since the head is formed by the thin film process, the miniaturization and high performance are attained.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to a thin film magnetic head for recording and reproducing;
In particular, the present invention relates to a thin film magnetic head in which an ear and a coil for recording and reproducing are separately formed on the same magnetic head.

(b) Prior Art and Problems A conventional thin film magnetic head is formed as shown in FIG. Figure 1 shows (a) a plan view and (b) a thin-film magnetic head.
) is a sectional view taken along line A-A. Two lower magnetic pole layers, a gap layer 3, an insulating layer 4, a coil 5, and an upper magnetic pole layer "2B" are formed on one surface of a substrate 1 made of alumina, titanium, carbide Aa2o3 TiC, etc. by a thin film process, and a slider surface is formed on the end surface. 6 is formed, and a conductive material through which signals are transmitted and received is further bonded to the coil 5.

In a magnetic disk device, recording and reproduction are performed using such a thin film magnetic head. Generally, during playback, it is desirable to increase the number of turns of the coil 5 in order to increase the playback output, but as the number of turns increases, the intufftance OL increases in proportion to This has the disadvantage that the write current rises slowly.

In addition, in order to have a margin for off-track, it is desirable to write wide when writing and read narrowly when reading. The core width is wider than that for playback. However, in a magnetic disk device that uses the same head for recording and reproducing, it is impossible to form it in this way. However, it was also difficult to integrate the two.

(C) Purpose of the Invention The purpose of the present invention is to improve the recording gap' and the recording gap'.
The core width of each is set to be wide and narrow for reading, and a recording coil and a reproducing coil are formed separately, and the number of turns of each coil and the number of turns of the coil are set separately. The purpose of this invention is to eliminate the above-mentioned problems by setting the area optimally.

(d) Structure of the Invention An object of the present invention is to provide a thin-film magnetic head in which a magnetic layer 1 is provided between the first magnetic pole layer laminated on one surface of the substrate and the second magnetic pole layer. A second gear 77 is provided between the second magnetic pole layer provided with sauce and fully laminated, and the second magnetic pole layer.
A third magnetic pole layer is provided, and a first coil is provided between the first and second magnetic pole layers, and a first coil is provided between the first and second magnetic pole layers. This is achieved by a thin film magnetic head characterized in that it has a second coil between the third magnetic pole layers.

(e) Examples of the invention The present invention will be explained in detail below with reference to FIG.

FIG. 2 shows an embodiment of the thin film magnetic head according to the present invention, in which (a) is a sectional view and (b) is a view taken in the direction of arrow 13.

On the substrate 1, a first magnetic pole layer 12A of a thin film of a high permeability magnetic material such as permalloy was formed, and then a first gear 270 layer 13A and an insulating layer 14A were formed. After that, the first coil layer 15A is formed and the insulation WI14 is
) 1, and a second magnetic pole layer 121J is formed therebetween.

On this second magnetic pole layer 12B, a second gap layer 13B and an insulating layer 14C,'-second coil layer 15 are formed as described above.
B, the insulation If414D, and the third magnetic pole layer 12C are laminated. When formed in this way, the slider surface 6 has the first and second magnetic pole layer 12A.

The core width tI of the first gap layer 13A formed by the first gap layer 12B can be wider than the core @t2 of the second gear gap layer 13B formed by the second and third pole layers 12B and 12C, and The magnitude of the gap length S, and 82 can also vary. Further, a coil layer 15. The number of turns and the cross-sectional area can also vary between A and 15B.

Therefore, the cap length S, is larger than S, and the coil layer 1
5A has fewer windings than 15B and has a larger cross-sectional area. During recording, a gear with a magnetic circuit formed by the coil layer 15A, length S l , and core width t1 are used, and during reproduction, the coil layer 1513 is used. A gear in which a magnetic circuit is formed, a pull length S2, and a core width t2 are used.

In this way, since the reproduction is performed by the narrow width t2 for the wide recording width tl, an off-track margin can be obtained. In addition, since the gear, gap length SI and gap length S are different, during reproduction, the reproduction loss is small (λ-1) and the override characteristic also satisfies a sufficient value of 7.
It becomes possible to cross paths.

Furthermore, in order to obtain the desired amperage of the coil layer 15A, the cross-sectional area of the coil is increased to allow a large current to flow in order to reduce the amount of heat generated, and the number of turns N is increased to increase the inductance L. On the contrary, the number of turns of the coil 7915B can be set so as to obtain the desired output voltage without having to take into account the increase in inductance L much.

(f) Detailed Description of the Invention As described above, the present invention includes stacking the first, second and third magnetic pole layers 12A and 1213.12C on one substrate 1,
Gap length S,, S2 and core width! ,.

t2, and coil layers 15A and 15B having different numbers of turns and cross-sectional areas are formed, and during recording, the first gap layer 13A is used,
The second gear and the down layer 13B are used during reproduction.

As a result, it is possible to write widely and read narrowly, and the number of turns of the coil can be set to the optimum conditions for recording and playback.Furthermore, since it can be formed using a thin film process, it can be made compact and high performance, and the practical effect is excellent. .

[Brief explanation of the drawing]

Figure 1 shows a conventional thin-film magnetic head (a) is a plan view, (b)
) is a sectional view taken along the line A-A, FIG. 2 is a cross-sectional view of an embodiment of the thin-film magnetic head according to the present invention, and FIG. 2 (b) is a view taken along arrow B. , 2A, 2B, ] 2A,. 12B, 12C are magnetic pole layers, 3.13A, 13B are gap layers, 4.14A, 14B, 14C, 14D are insulating layers,
5.15A, 15.8 is a coil layer, and 6 is a slider surface. 1st prisoner (li (b)

Claims (3)

[Claims] (1) A first magnetic pole layer laminated on one surface of the substrate, a second magnetic pole layer laminated with a first gap layer provided between the first magnetic pole layer, and the second magnetic pole layer laminated on one surface of the substrate; a third magnetic pole layer stacked with a second gap layer provided between the magnetic pole layer, and a first coil between the first and second magnetic pole layers; A thin film magnetic head characterized in that a second coil is formed between the second and third magnetic pole layers. (2) The thin film magnetic head according to claim (1), wherein the first and second gap layers have different gap lengths and core widths. (3) Are the numbers of turns of the first and second coils and the cross-sectional widths of the coil conductors different? - Thin film magnetic head 0 according to claim (1) characterized by: