JPH056514A - Thin-film magnetic head - Google Patents

Abstract

PURPOSE:To enable recording on a high-coercive force medium to be carried out without having partial magnetic flux saturation of intermediate cores since the reduction in the thickness in the perpendicular direction from the medium- facing surface of the intermediate cores is prevented by a spacer even if a life size is set short and to obtain recording characteristics of good efficiency since the leakage of magnetic fluxes can be decreased by the spacer. CONSTITUTION:This invention relates to an improvement of the thin-film magnetic head constituted by forming a lower core 4, an upper core 9 and the intermediate cores 8a, 8b connecting these cores of the magnetic materials in insulating layers 3, 5, 11, the front surfaces of these insulating layers including the connecting surfaces of the above-mentioned cores being approximately flat, and by forming a gap 7 in the juncture between the lower core 4 and the intermediate core 8a. The spacer layer 14 thicker than the gap 7 (layer) is formed between the lower core 4 and the intermediate core 8a holding the gap 7 (t<s).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film magnetic head, and more particularly to a thin film magnetic head suitable for high density magnetic recording.

[0002]

2. Description of the Related Art First, the structure and manufacturing method of a conventional thin film magnetic head 20 will be described with reference to FIG. A magnetic film is formed on the substrate 21, and the lower core 22 is formed by photolithography or etching. The non-magnetic material 24 is formed on the lower core 22 so that the end portion becomes the (magnetic) gap 23. Next, the insulating layer 25 and the conductor layer are formed, and the coil pattern 2 is formed by using photolithography, etching, or the like.
6 An insulating layer 27 and a magnetic layer are formed on the stepped coil forming surface on which the coil pattern 26 is formed to form an upper core 28.

In the conventional thin film magnetic head 20, an insulating layer 27 is formed on a coil pattern 26 having a step with the insulating layer 25, and the upper core 2 is formed on the insulating layer 27.
Since 8 is formed, the step becomes larger as the layers are stacked. For example, the usual thickness of both cores is about 5 μm,
When the coil pattern has a thickness of about 3 μm, the step difference reaches 10 μm immediately before the upper core is formed.

On a surface having such a step, the resolution due to photolithography becomes extremely poor, and the resolution is limited to the size of the step. Therefore, in order to increase the number of turns of the coil, it is not possible to reduce the pitch interval of the coil pattern 26 because the resolution is poor. As a result, it is necessary to increase the lengths of the upper and lower cores 22 and 28 formed above and below the magnetic core, and the magnetic resistance increases due to the increase in the magnetic path length, resulting in a problem that the performance of the thin film magnetic head deteriorates. there were.

As a solution to these problems,
There is a thin film magnetic head described in Japanese Patent Application Laid-Open No. 3-58308 filed earlier by the present applicant. As shown in FIG. 9, a core-shaped groove is formed in the insulating layer by etching,
A thin film magnetic head 30 is formed by filling the groove with a magnetic material, flattening the surface, and stacking the surfaces to form a magnetic circuit.
31, 32a, 32b and 33 are cores made of magnetic material, 3
5 is a coil pattern, 36, 37, 38 are insulating layers, 39
Is the magnetic gap.

[0006]

SUMMARY OF THE INVENTION The thin film magnetic head 3 described above.
0 has the following problems, and it is difficult to provide a thin film magnetic head having high performance and high reliability. Normally, the length from the surface where the head faces the medium (slider surface) to the point where the gap starts to open is called the life size or the gap depth (1 in FIGS. 9 and 10). If this is large, the life of the head due to wear is extended. However, if it is too large, the magnetic resistance becomes large, so that the leakage magnetic flux at the tip of the gap decreases at the time of recording and the efficiency decreases, and the output decreases at the time of reproducing. Therefore, it is necessary to set the length appropriately. For example, in the case of a floating head for a magnetic disk, the life size is generally 1 μm.
It is set before and after. However, as shown in FIG. 10, the shorter the life dimension is set, the thinner the thickness of the intermediate core in the direction perpendicular to the medium facing surface becomes.

A thin film magnetic head 30 as shown in FIG.
In the above, since the core-shaped groove is processed by, for example, reactive dry etching (RIE), the etching side wall is likely to have a vertical shape, and the magnetic material (core) cross section embedded therein is also vertical, so that the core for one layer is formed. Has a block shape. By stacking such block-shaped cores, a ring-shaped magnetic circuit is formed as a whole, so that the core has an angular core cross-sectional shape, and the magnetic flux of the thin-film magnetic head shown in FIG. G1)
The magnetic flux (G2 in the figure) is less likely to concentrate at the tip of the magnetic gap, as compared with.

[0008]

In order to solve the above-mentioned problems, the present invention comprises a lower core, an upper core, and an intermediate core connecting them, which are made of a magnetic material in an insulating layer. In a thin film magnetic head in which the surface of each of the insulating layers including is substantially flat and a gap is formed in the connecting portion of the core, a thin film in which a spacer layer thicker than the gap layer is formed between the cores sandwiching the gap. A magnetic head is provided.

In the thin-film magnetic head constructed as described above, the vertical thickness L from the medium facing surface of the core sandwiching the gap by the spacer thicker than the gap layer does not become smaller than the life dimension l (L> l). ), There is no partial flux saturation of the core. Further, since the spacer layer is formed between the cores that sandwich the gap, leakage of magnetic flux is reduced.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the thin film magnetic head according to the present invention will be described in detail below with reference to the drawings. This thin-film magnetic head is for forming a core-shaped groove in an insulating layer by etching, filling the groove with a magnetic material to planarize the surface, and stacking it to form a magnetic circuit. A spacer layer that is thicker than the gap layer is formed between the magnetic layers (cores) sandwiching the gap.

[Embodiment 1] FIG. 1 is a schematic sectional view showing a thin film magnetic head 1 according to the present invention. As shown in the figure, a flat lower insulating layer 3 is formed on the substrate 2, and a groove formed in the lower insulating layer 3 is filled with a magnetic material, so that the lower insulating layer 3 and the lower insulating layer 3 are flat. The lower core 4 formed in the above is formed.

An intermediate insulating layer 5 is formed on the lower insulating layer 3 and is made of a magnetic material at an end (the recording medium facing surface 6) of the intermediate insulating layer 5 via a (magnetic) gap 7. An intermediate core 8a is embedded so as to be close to the lower core 4, and an intermediate core 8b made of a magnetic material is embedded so as to be directly bonded to the lower core 4 inside the intermediate core 8a at a distance from the intermediate core 8a. Inside the intermediate insulating layer 5, a planar coil pattern 10 is embedded in a spiral shape so as to surround the intermediate core 8b. One end of the coil pattern 10 is joined to an external lead wire 13 via a conductor 12 buried in a through hole formed in the upper insulating layer 11 and can be electrically connected to an external device. ing. Reference numeral 15 is an insulating layer between the coil pattern 10 and the upper core 9.

An upper insulating layer 11 is formed on the intermediate insulating layer 5, and an upper core 9 is formed on the upper insulating layer 11 so that both ends thereof are joined to the intermediate cores 8a and 8b. A magnetic circuit is formed with the lower core 4. Furthermore, between the upper core 9 and the intermediate core 8a that sandwich the gap 7,
A spacer layer 14 (thickness s) thicker than the gap (layer) 7 (thickness t) is formed on the upper core 9 (t <s). The thickness of the end portion 14a of the spacer layer 14 decreases toward the head end portion (the recording medium facing surface 6, the gap 7), and the end portion 14a of the spacer layer 14 is tapered.

As described above, in the thin-film magnetic head 1 according to the present invention, three flat insulating layers, that is, the lower insulating layer 3, the intermediate insulating layer 5 and the upper insulating layer 11 are stacked, and these flat insulating layers are stacked. Since the magnetic layer formed at a predetermined position is connected to form a magnetic circuit, photolithography can be performed on each insulating layer surface without a step. Therefore, since a small coil pattern / magnetic core having excellent dimensional accuracy can be obtained, it is possible to obtain a thin-film magnetic head having low magnetic resistance and good performance.

Further, even if the life dimension (l in the figure) is set to be short, the spacer 14 does not reduce the thickness L of the intermediate core 8a in the vertical direction from the medium facing surface, so that partial magnetic flux saturation of the core occurs. However, it is possible to record on a high coercive force medium. Moreover, since the leakage of magnetic flux can be reduced by forming the spacer (layer) 14, efficient recording characteristics can be obtained. Further, by making the end portion 14a of the spacer 14 into a tapered shape, the magnetic field at the head tip portion (near the gap) is concentrated at the gap tip, so that efficient writing is possible.

Next, a method of manufacturing the thin film magnetic head 1 will be described with reference to FIGS. First step (A in FIG. 6) An insulating layer 3 of SiO2, TiO2, WO3 or the like is formed on the substrate 2 in an amount of 1 to 10 μm.
Is formed by sputtering, vapor deposition, CVD, etc., and the core-shaped groove 4X is formed by photolithography and etching.

Second step (B in FIG. 6) A soft magnetic thin film containing Fe, Co, and Ni as main components is formed to be thicker than the depth of the groove 4X by sputtering, vapor deposition, CVD, plating, etc. The magnetic layer is removed to flatten the surface to form the lower core 4.

Third step (C in FIG. 6) A material having a low etching rate with respect to dry etching with an etching agent such as CF4 (eg, CaTiO3, Ba)
TiO3, ZrO2, α-Fe2O3, etc.) is deposited by sputtering or the like to a thickness of 1 to several μm, and the portion where the intermediate cores (8a, 8b) and the lower core 4 are connected is removed by a method such as ion milling. . This layer becomes the spacer 14 (thickness s). Also,
By making the end portion 14a of the spacer 14 into a tapered shape, the magnetic field can be made steeper. The tapered shape can be easily obtained by appropriately selecting the ion beam incident angle during the ion milling process.

Fourth Step (D in FIG. 6) On the lower core 4 and the spacer 14, an insulating layer 5 of SiO2, TiO2, WO3 or the like is formed in a thickness of 1 to 5 μm.

Fifth Step (E in FIG. 6) A coil-like groove is formed in the insulating layer 5 by etching similarly to the core, and a conductor film of Cu, Al, Au, Ag or the like is deposited,
The coil 10 is formed by sputtering, plating, etc., and the excess conductor in the upper layer is removed by polishing to flatten the surface to form the coil 10. At the time of forming the coil groove, the spacer 14 is made of a material having an etching rate slower than that of the insulating layer 5 which is the material to be processed. Therefore, the spacer 14 functions as an etching stopper, the etching is stopped at the upper portion of the spacer 14, and the lower core 4 is reached. Prevents the etching from proceeding. The spacer 14 electrically insulates the coil 10 from the lower core 4.

Step 6 (F in FIG. 6) Si is used for electrical insulation between the upper core (9) and the coil 10.
An insulating layer 15 of O2, TiO2, WO3 or the like is formed to a thickness of 0.1 to 1 μm.

Step 7 (G in FIG. 6) The groove 8aX of the front intermediate core 8a is formed by photolithography and etching. At this time, the groove 8aX is not etched to the magnetic substance of the lower core 4 and etching is stopped by leaving the gap length (thickness t), and the remaining insulating layer becomes the (magnetic) gap 7. Spacer 1 exposed during etching
Since No. 4 has a small etching rate, there is almost no reduction in film thickness due to etching.

Eighth step (A in FIG. 7) The rear intermediate core groove 8bX is etched. At this time, groove 8
bX is etched until it reaches the lower core 4.

Ninth step (B in FIG. 7) A soft magnetic thin film containing Fe, Co, and Ni as main components is formed in the grooves 8aX, 8bX of the intermediate core by sputtering, vapor deposition, CVD, plating or the like to be thicker than the groove depth. Then, the excess magnetic layer on the upper side is removed by polishing to flatten the surface to form intermediate cores 8a and 8b.

Tenth Step (C in FIG. 7) An insulating layer 11 of SiO2, TiO2, WO3 or the like is formed on the intermediate cores 8a and 8b to a thickness of 1 to 10 μm.

Eleventh Step (D in FIG. 7) The upper core 9 is formed on the insulating layer 11 in the same manner as the lower core 4.

Twelfth step (E in FIG. 7) A through hole is formed by etching in the upper insulating layer 11 of the coil 10 and the inside of the through hole is filled with the conductor 12.
A conductor film of Cu, Al, Au, Ag or the like is formed to a thickness of about 1 μm by vapor deposition, sputtering, plating, etc., and the lead wire 13 is formed by photolithography and etching. Finally, the chip is cut and processed up to the X-X line by a process such as polishing to obtain a predetermined magnetic head shape.

[Embodiment 2] FIG. 2 shows a thin film magnetic head 16 in which a (magnetic) gap 7 is set between an upper core 9 and an intermediate core 8a. In the thin film magnetic head 16, a spacer 14 is provided between the upper core 9 and the intermediate core 8a.

[Embodiment 3] FIG. 3 shows two layers of coil patterns 10-1, 10-2 and two layers of lower intermediate cores 8a-1, 8b-.
1. The thin film magnetic head 17 is composed of the upper intermediate cores 8a-2 and 8b-2, and the (magnetic) gap 7 is set between the lower core 4 and the lower intermediate core 8a-1. This thin film magnetic head 17
Has a spacer 14 between the lower core 4 and the lower intermediate core 8a-1.

[Embodiment 4] FIG. 4 shows two layers of coil patterns 10-1, 10-2 and two layers of lower intermediate cores 8a-1, 8b-.
1. The thin film magnetic head 18 is composed of the upper intermediate cores 8a-2 and 8b-2, and the (magnetic) gap 7 is set between the lower intermediate core 8a-1 and the upper intermediate core 8a-2. In the thin film magnetic head 18, the spacer 14 is provided between the lower intermediate core 8a-1 and the upper intermediate core 8a-2.

[Embodiment 5] FIG. 5 shows two layers of coil patterns 10-1, 10-2 and two layers of lower intermediate cores 8a-1, 8b-.
1. The thin film magnetic head 19 is composed of the upper intermediate cores 8a-2 and 8b-2, and the (magnetic) gap 7 is set between the upper core 9 and the upper intermediate core 8a-2. In the thin film magnetic head 19, a spacer 14 is provided between the upper core 9 and the upper intermediate core 8a-2.

The thin film magnetic head 14 shown in Examples 2 to 5
Also in # 17, since flat insulating layers are stacked and magnetic layers formed at predetermined locations in these insulating layers are connected to form a magnetic circuit, photolithography is possible on each insulating layer surface without steps. Becomes Therefore, since a small coil pattern / magnetic core having excellent dimensional accuracy can be obtained, it is possible to obtain a thin-film magnetic head having low magnetic resistance and good performance.

Further, even if the life dimension (1 in the figure) is set to be short, the spacer 14 does not reduce the thickness L of the intermediate core 8a in the vertical direction from the medium facing surface, so that partial magnetic flux saturation of the core occurs. However, it is possible to record on a high coercive force medium. Moreover, since the leakage of magnetic flux can be reduced by forming the spacer (layer) 14, efficient recording characteristics can be obtained. Further, by making the end portion 14a of the spacer 14 into a tapered shape, the magnetic field at the head tip portion (near the gap) is concentrated at the gap tip, so that efficient writing is possible.

[0034]

In the thin-film magnetic head according to the present invention, the lower core, the upper core, and the intermediate core connecting them are made of a magnetic material in the insulating layer, and the insulating layer including the connecting surface of each core is formed. In a thin film magnetic head having a substantially flat surface and a gap formed in the connecting portion of the core, a spacer layer thicker than the gap layer is formed between the cores sandwiching the gap, so that the life dimension is shortened. Even if set, the spacer does not reduce the thickness of the core in the direction perpendicular to the medium facing surface that sandwiches the gap, so there is no partial magnetic flux saturation of the core and recording on high coercive force media is possible. Since leakage of magnetic flux can be reduced, efficient recording characteristics can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an embodiment of a thin film magnetic head according to the present invention.

FIG. 2 is an example of a thin film magnetic head in which a magnetic gap is set between an upper core and an intermediate core.

FIG. 3 is an example of a thin film magnetic head in which a coil (and an intermediate core) has two layers and a magnetic gap is set between the lower core and the lower intermediate core.

FIG. 4 is an example of a thin film magnetic head in which a coil (and an intermediate core) has two layers and a magnetic gap is set between an upper intermediate core and a lower intermediate core.

FIG. 5 is an example of a thin film magnetic head in which a coil (and an intermediate core) has two layers and a magnetic gap is set between the upper core and the upper intermediate core.

FIG. 6 is a manufacturing process of a thin film magnetic head according to the present invention (first
It is a figure which shows the process to the 7th process.

FIG. 7: Manufacturing process of thin film magnetic head according to the present invention (eighth embodiment)
It is a figure which shows the process to the 12th process.

FIG. 8 is a schematic sectional view showing a conventional thin film magnetic head.

FIG. 9 is a schematic cross-sectional view showing a conventional thin film magnetic head, and is a view for explaining a state in which the magnetic field does not become steep because the core is angular.

FIG. 10 is a schematic cross-sectional view showing a conventional thin film magnetic head,
It is a figure explaining a magnetic path becoming narrow according to the size of life.

[Explanation of symbols]

1 Thin film magnetic head 2 substrates 3 Lower insulation layer 4 Lower core 5 Intermediate insulation layer 6 Recording medium facing surface 7 (Magnetic) gap 8 Intermediate core 8a-1, 8b-1 Lower intermediate core 8a-2, 8b-2 Upper intermediate core 9 Upper core 10 coil pattern 10-1, 10-2 coil pattern 12 Lower core 14 Spacer (layer) 14a End of spacer (layer) 15 Insulation layer 16-19 Thin film magnetic head s Spacer (layer) thickness t Gap thickness (gap length) l Life size (gap depth)

Claims (3)

[Claims] 1. A lower core, an upper core, and an intermediate core connecting them are made of a magnetic material in an insulating layer, and a surface of each insulating layer including a connecting surface of each core is substantially flat. A thin film magnetic head having a gap formed at a connecting portion of cores, wherein a spacer layer thicker than a gap layer is formed between cores sandwiching the gap. 2. A thin-film magnetic head according to claim 1, wherein the spacer layer material has a lower etching rate than the insulating layer material which is the workpiece. 3. The thin film magnetic head according to claim 1, wherein the spacer layer has a taper shape in which the thickness of the end portion decreases toward the gap.