JPH0490111A - Thin-film magnetic head - Google Patents

Abstract

PURPOSE:To allow the setting at the same number of turns and resistance on upper and lower coil sides by forming an upper core and lower coil to a shape vertically symmetrical with a gap as a boundary and flatly winding an upper coil and lower coil to the shape vertically symmetrical with the gap as a boundary. CONSTITUTION:An alumina layer 9 of the lower core 13 is built up and formed to the inclined shape in the throat part 13a of the lower core 13 and the rear part 14e of the lower coil 14b. An alumina layer 10 is also built up and formed in the shaft part 13A to the upper core 16 and is formed thereon. The upper core 13 is formed to the shape vertically symmetrical with the lower core 16 with the gap 5 as a boundary. The upper coil 14a and the lower coil 14b are flatly wound and formed to the shape vertically symmetrical with the gap 5 as a boundary. Then, the upper and lower coils which are formed in multiple layers are formed to the vertically symmetrical shape and an intermediate terminal 11A is provided in the position of half the number of turns of the upper and lower coils. The setting at the same number of turns and resistance on the upper and lower coil side is possible in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thin film magnetic head used in magnetic disk drives and the like.

[Conventional technology] Conventional thin film magnetic heads are shown in FIGS. 3 to 7.

FIG. 5 shows the slider of the magnetic head device, and FIG. 6 is a partially enlarged view thereof. In each time, 20 is a slider,
21 is a magnetic head formed on the end face of the slider 20.

3 and 4 are cross-sectional views of the magnetic head, and in each figure, 1 is a base material wafer, 2 is an alumina film formed on this base material wafer 1, 3 is a lower core, 4a, 4b are upper and lower coils wound 2M in a plane in an insulating layer 7, 5 is a gap (layered to form a thin film and extends backward), 6 is an upper core, and 8 is an alumina protective layer. The upper core 6 is formed into a heart shape when viewed from above, as shown in FIGS. 6 and 7, and the lower core 3 is formed into a flat plate shape. When viewed in cross section, the upper core 6 has a tip 6a.
It is formed so as to be close to the lower core 3 with its side inclined, and the tip 6a faces the lower core 3 with a gap 5 interposed therebetween.

Next, the function of the thin film magnetic head having this structure will be explained. Leakage and intake of the magnetic flux necessary for recording and reproduction in the magnetic head 21 is performed by interruption of the magnetic path by the gap 5 sandwiched between the upper core 6 and the lower core 3. The generation of a magnetic field in this magnetic path is performed by passing current through the upper and lower coils 4a and 4b insulated by the insulation N7,
Thereby, magnetic flux leakage necessary for magnetic recording can be generated in the gap 5. Furthermore, during reproduction, the magnetic flux from the magnetic medium (not shown) crosses the gap 5, causing a change in the magnetic flux within the magnetic path, which causes magnetomotive currents to flow in the upper and lower coils 4a and 4b, resulting in magnetic flux. A reading of the record is performed.

In order to faithfully perform this magnetic recording/reproduction, it is necessary that the magnetic domains in the core are formed as shown in Figure 7, and for this reason, the lower core 3 should be formed into a flat plate shape that facilitates the formation of optimal magnetic domains. However, the shape of the upper core 6 has a smooth slope so that the optimum magnetic domain can be easily formed, and the upper and lower coils 4a
, 4b.

[Problems to be Solved by the Invention] Since the conventional thin film magnetic head is configured as described above, when the coil is multilayered, if an attempt is made to increase the cross-sectional area of the coil in order to lower the resistance value of the coil, As shown in FIGS. 3 and 4, the insulating layer 7 forming the coil is formed in an inclined shape on the tip 6a side of the upper core 6, so that the upper side is narrower.
The number of turns cannot be increased compared to the lower coil 4b located below. Therefore, there is a difference in the number of turns between the upper coil 4a and the lower coil 4b, and at the contact portion between the upper coil 4a and the lower coil 4b, for example,
Even if the intermediate terminal 11 is formed at 1/2 of the number of turns of the lower coil 4b, the stiffness will not be at 1/2 of the number of turns of the lower coil 4b, and the number of turns and resistance will be different between the upper coil 4a side and the lower coil 4b side. This problem became more serious as the number of layers of coils increased to three or four layers.

The present invention was made to solve the above problems, and
The thin-film magnetic head is capable of forming multi-layered upper and lower coils symmetrically in the upper and lower directions, providing an intermediate terminal at the position of 172 turns of the upper and lower coils, and setting the same number of turns and resistance on the upper and lower coil sides. The purpose is to obtain.

[Means for Solving the Problems] The thin film magnetic head of the present invention has upper and lower cores that face each other so as to sandwich a part of the circumference of the coil from above and below, and that are inclined so that their tips are close to each other. The upper core and the lower core are arranged in a shape that is symmetrical upwardly and downwardly with a gap formed between the tips as a boundary, and the upper coil and the lower coil are wound in a plane in a shape that is symmetrically upwardly and downwardly with the gap formed as a boundary. It is made by turning.

[Function] The lower core and the upper core are vertically symmetrical and formed into a smooth arc shape with the gap as the boundary, making it easy to form an optimal magnetic domain. A magnetic path can be formed. Further, the upper coil and the lower coil can be formed vertically symmetrically with the gap as a boundary, and the intermediate terminal can be provided at the position where the number of turns of the upper and lower coils is 172.

[Embodiment of the Invention] Hereinafter, an embodiment of a thin film magnetic head of the present invention is shown in FIG.
This will be explained based on FIG. Components that are the same as those in the conventional example shown in FIGS. 3 to 7 are denoted by the same reference numerals, and description thereof will be omitted.

In each cycle, 13 is the lower core, 14b is the lower coil formed in a plane on the insulating layer 17b between the gap 5 and the lower core 13, 16 is the upper core, and 14a is the between the upper core 16 and the gap 5. 2 in a planar manner on the insulating layer 17a of
Layered upper coil. That is, in the lower core 13, the alumina layer 9 is formed in an inclined shape at the throat part 13a of the lower core 13 and the rear part 14e of the lower coil 14b, and the alumina layer 10 is also formed at the shunt part 13A with the upper core 16. By forming a ridge,
formed on it. Further, the upper core 16 is connected to the gap 5
It is formed in a shape that is vertically symmetrical to the lower core 13 with the border as the boundary. These upper and lower cores 16.13 are the upper and lower coils 14a.

They are formed so as to face each other with a part of the circumference of 14b sandwiched therebetween from above and below. Therefore, the lower core 13 and the upper core 16 are similarly formed into a smooth arc shape, which makes it easy to form an optimal magnetic domain. An optimal magnetic path can be formed. Further, the upper coil 14a and the lower coil 14b can be formed vertically symmetrically with respect to the gap 5 as a boundary, and the intermediate terminal 11A can be formed with 1/2 the number of turns of the upper and lower coils.
It can be installed in the position of , and the number of turns on the upper and lower coil sides,
You can set the resistance the same.

In the above embodiment, the inclined alumina layer 9,
10 is shown as being additionally formed on the alumina film formed on the base material wafer 1, but the alumina film on the base material wafer 1 may be etched to form an inclined shape.

[Effects of the Invention] As explained above, according to the thin film magnetic head of the present invention, the coils face each other so as to sandwich a part of the circumference from above and below,
and the upper core and the lower core are shaped symmetrically upward and downward with respect to a gap formed between the tips of the upper and lower cores, which are inclined so that the tips are close to each other, and the upper coil is formed with the gap as a boundary. Since the upper and lower coils are wound in a flat plane in a symmetrical shape, the multilayered upper and lower coils can be formed vertically symmetrically, and the intermediate terminal can be placed at the 172nd position of the number of turns of the upper and lower coils. The number of turns and resistance can be set to be the same on the upper and lower coil sides.

[Brief explanation of the drawing]

1 and 2 are main part sectional views and sectional views showing one embodiment of the thin film magnetic head of the present invention, FIGS. 3 to 7 show an example of a conventional thin film magnetic head, and FIG. 4 is a sectional view of the main part, FIG. 5 is a perspective view of the slider on which the magnetic head is formed, FIG. 6 is a partially enlarged view of FIG. 5, and FIG. 7 shows the state of magnetic domain formation in the upper core. FIG. 5... Gap, 13... Lower core, 14a...-
Upper coil, 14b...lower coil, 16...upper core. Agent Patent Attorney Jun Miyazono - Figure 6 Figure 5

Claims (1)

[Claims] An upper coil and a lower coil are wound in a plane and are opposed to each other, and the upper and lower coils are opposed to each other so as to sandwich a part of the circumference from above and below, and are inclined so that their tips are close to each other. comprising an upper core, a lower core, and a gap formed between the tips of the upper and lower cores, wherein the upper core and the lower core are symmetrical upwardly and downwardly with the gap as a boundary, and the gap is the boundary. 1. A thin film magnetic head characterized in that an upper coil and a lower coil are wound in a symmetrical top and bottom shape.