JPH10228611A - Composite type thin film magnetic head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively suppress the occurrence of leakage magnetic flux to flow into an MR element layer at the time of recording a signal in the composite type thin film magnetic head constituted in such a manner that an MR head part and an induction type head part are laminated on a substrate, where the induction type head part is arranged with a lower core layer and an upper core layer on both sides of a gap spacer layer, while the MR head part is arranged with a lower shield layer on the side of a substrate of an MR element layer. SOLUTION: In the composite type thin film magnetic head, the lower shield layer 3 is formed in a planar shape without vertically overlapping with a back gap part 92 formed between the upper core layer 7 and the lower core layer 6. Then, the lower shield layer 3 is formed by filling a magnetic material into a recessed part formed in an insulation layer 2 on the substrate 1, and the surfaces of the insulation layer 2 and the lower shield layer 3 are arranged at the same planar level.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite thin film magnetic head used for a magnetic recording / reproducing apparatus such as a hard disk drive.

[0002]

2. Description of the Related Art In recent years, in a hard disk drive or the like as an external storage device of a computer, an inductive head for recording a signal and a magnetoresistive head for reproducing a signal (hereinafter referred to as an MR head). A composite type thin-film magnetic head having a single structure has attracted attention.

FIG. 2 shows a cross section perpendicular to a recording medium in a conventional composite type thin film magnetic head. On a substrate (1), an insulating layer (2), a lower shield layer (31), an insulating layer (5), and an MR element layer (4) are laminated as an MR head. On the MR head, a lower core layer (6), a coil layer (8), an insulating layer (81),
A gap spacer layer (9) and an upper core layer (7) are laminated. Then, a protective layer (91) is formed to cover both head portions. The lower core layer (6) functions as a magnetic core of the induction type head part and also functions as an upper shield layer for providing a magnetic shield between the induction type head part and the MR head together with the lower shield layer (31). It also has.

FIG. 5 shows a plan view of a lower shield layer (31) and an upper core layer (7) of the composite type thin film magnetic head. The lower shield layer (31) is composed of an upper core layer (7). ).

[0005]

In the conventional composite type thin film magnetic head, the MR element layer (4) of the MR head portion and the back gap portion of the induction type head portion are provided in the plane area of the lower shield layer (31). 2, a part of the magnetic flux at the time of signal recording formed around the coil layer (8) penetrates through the MR element layer (4), as shown by the broken line in FIG. It leaks to the shield layer (31), and the upper core layer (7), the MR element layer (4), the lower shield layer (31) and the back gap (9)
A magnetic loop passing through 2) is formed.

It is ideal that the MR element layer (4) has a single magnetic domain. However, in practice, some magnetic domains are formed. In this case, when the leakage magnetic flux flows through the MR element layer (4) as described above, the magnetic domains move or deform (enlarge or reduce), and the disturbance of the magnetic domains remains after the recording is completed. As a result, there has been a problem that the head characteristics at the time of signal reproduction change, which may cause noise in some cases. SUMMARY OF THE INVENTION It is an object of the present invention to provide a composite thin-film magnetic head capable of effectively suppressing generation of leakage magnetic flux flowing through an MR element layer.

[0007]

The composite thin-film magnetic head according to the present invention is constructed by laminating an MR head and an inductive head on a substrate (1). The inductive head unit has a lower core layer on the MR head unit side with the gap spacer layer (9) interposed therebetween.
(6) The upper core layer (7) is arranged on the opposite side. Further, the MR head portion is configured by disposing a lower shield layer (3) on the substrate (1) side of the MR element layer (4). here,
The lower core layer (6) of the inductive head also has a function as an upper shield layer of the MR head. Further, the lower shield layer (3) is formed in a planar shape that does not vertically overlap the back gap portion (92) formed between the upper core layer (7) and the lower core layer (6). I have.

In the composite type thin-film magnetic head of the present invention, the lower shield layer (3) of the MR head and the back gap (92) of the inductive head do not overlap in the vertical direction.
Since they are sufficiently separated from each other, the magnetoresistance between the lower shield layer (3) and the back gap portion (92) becomes larger than in the prior art. Therefore, at the time of signal recording, a magnetic loop penetrating the MR element layer (4) is formed as described above, and the MR element layer (4) is formed.
The situation where the leakage magnetic flux flows in (4) is effectively prevented.

In a specific configuration, the lower shield layer (3)
Is formed by filling a concave portion (21) formed in an insulating layer (2) on a substrate (1) with a magnetic material, and forming an insulating layer (2) and a lower shield layer.
The surface of (3) is aligned on the same plane. In the composite type thin-film magnetic head having the specific configuration, in the manufacturing process, the surfaces of the insulating layer (2) and the lower shield layer (3) are flat, and there is no step between the two layers. In the subsequent manufacturing process, the thin film formed on these layers (2) and (3) does not have irregularities or steps due to the steps. Therefore, high shape accuracy can be realized for the MR head portion and the induction type head portion.

In a more specific configuration, the lower shield layer (3) is formed in a U-shaped planar shape that branches from an end on the side facing the recording medium to both sides of the back gap (92). I have. Thereby, the magnetic shield function of the lower shield layer (3) is sufficiently exhibited.

[0011]

According to the composite type thin film magnetic head of the present invention, it is possible to effectively prevent a situation in which a leakage magnetic flux flows through the MR element layer at the time of signal recording, thereby obtaining a stable reproduction characteristic. I can do it.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings. As shown in FIG. 1, the composite type thin film magnetic head according to the present invention has an Al ₂ O ₃ —Ti
An insulating layer (2), a lower shield layer (3), an insulating layer (5) and an MR element layer (4) are laminated as an MR head on a substrate (1) made of C or the like. Also, on the MR head,
Lower core layer (6), coil layer as inductive head
(8), an insulating layer (81), a gap spacer layer (9), and an upper core layer (7) are laminated. Then, a protective layer (91) is formed to cover both head portions. Where the lower core layer
(6) has a function as a magnetic core of the induction type head part and a function as an upper shield layer for applying a magnetic shield between the induction type head part and the MR head part together with the lower shield layer (31). .

The lower shield layer (3) of the induction type head portion is
It is formed by filling a concave portion of the insulating layer (2) with a magnetic material such as sendust. The back gap (92) formed between the upper core layer (7) and the lower core layer (6) is vertically aligned. Are formed in a planar shape without overlapping. In the cross section of FIG. 1, the length A from the medium facing surface S (for example, 40 to 5
0 μm) is larger than the depth L of the MR element layer (4) and smaller than the distance B (for example, 60 μm to 100 μm) from the medium facing surface S to the back gap portion (92).

As shown in FIG. 3, the specific planar shape of the lower shield layer (3) is a U-shape branching from the end on the medium facing surface S side to both sides of the back gap portion (92). ,
Both ends extend rearward from the back gap portion (92). Here, the lower shield layer (3) is at least MR
The necessary magnetic shield function is exerted because it extends to the plane region including the element layer (4). The lower shield layer
(3) can be formed in a shape terminating at a distance A from the medium facing surface S as shown in FIG. 4, but by forming a U-shape as shown in FIG. A magnetic shielding function can be obtained.

FIG. 6 shows a step of forming the lower shield layer (3). As shown in FIG. 6A, an insulating layer 20 made of Al ₂ O ₃ or the like is formed on the substrate 1 at a thickness of, for example, 6 μm, and the insulating layer 20 is subjected to reactive ion etching (RIE). Or ion beam etching (IBE), depending on the desired shape of the lower shield layer (3), for example, a depth of 2 μm.
The concave portion (21) is formed. Next, as shown in FIG.
Then, a magnetic material such as Sendust or Permalloy is sputtered to form a magnetic layer (32) having a thickness of, for example, 2.3 μm. Subsequently, the magnetic layer (32) and the insulating layer (20) are subjected to plane polishing, and the insulating layer (2) and the lower shield layer (3) having the same surface as shown in FIG. To form At this time, the lower shield layer (3) is polished to a thickness of, for example, 1.7 μm. When the lower shield layer (3) is formed from sendust, heat treatment is performed at about 500 ° C. Thereafter, through the same steps as in the prior art, the respective thin films constituting the MR head portion and the induction type head portion shown in FIG. 1 are sequentially formed to complete the composite type thin film magnetic head.

In the composite type thin-film magnetic head of the present invention, as shown in FIG.
And the back gap portion (92) of the induction type head portion do not overlap in the vertical direction and are sufficiently separated from each other, so that the magnetoresistance between the lower shield layer (3) and the back gap portion (92) is
It will be larger than before. Therefore, at the time of signal recording, a magnetic loop passing through the upper core layer (7), the gap spacer layer (9), the lower core layer (6) and the back gap portion (92) is formed as shown by the broken line, and In this case, the amount of leakage magnetic flux flowing through the MR element layer (4) is suppressed to almost zero. As a result, the magnetic field of the MR element layer (4) is prevented from being disturbed, and the occurrence of noise during signal reproduction is suppressed.

The description of the above embodiments is for the purpose of explaining the present invention, and should not be construed as limiting the invention described in the claims or reducing the scope thereof.
In addition, the configuration of each part of the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made within the technical scope described in the claims.

[Brief description of the drawings]

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

FIG. 2 is a sectional view of a conventional composite thin film magnetic head.

FIG. 3 is a diagram illustrating a planar shape of a lower shield layer.

FIG. 4 is a diagram illustrating another planar shape of the lower shield layer.

FIG. 5 is a diagram illustrating a planar shape of a conventional lower shield layer.

FIG. 6 is a process chart showing a method of forming a lower shield layer.

[Explanation of symbols]

 (1) Substrate (2) Insulation layer (3) Lower shield layer (4) MR element layer (5) Insulation layer (6) Lower core layer (7) Upper core layer (8) Coil layer (9) Gap spacer layer ( 91) Protective layer

Continuation of front page (72) Inventor Naoto Matino 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd.

Claims (3)

[Claims] A magnetoresistive head and an inductive head are laminated on a substrate, and the inductive head is located on the magnetoresistive head side with a gap spacer layer interposed therebetween. A lower core layer (6) and an upper core layer (7) disposed on the opposite side are arranged. Shield layer
(3) is arranged, and the lower core layer of the induction type head portion
In the composite type thin film magnetic head in which (6) also functions as the upper shield layer of the magnetoresistive head, the lower shield layer (3) is composed of the upper core layer (7) and the lower core layer (6). A composite thin-film magnetic head characterized in that it is formed in a planar shape that does not vertically overlap with a back gap portion (92) formed therebetween. The lower shield layer (3) is formed by filling a concave portion (21) formed in the insulating layer (2) on the substrate (1) with a magnetic material, and the insulating layer (2) and the lower shield layer are formed. The composite thin-film magnetic head according to claim 1, wherein the surfaces of the layer (3) are flush with each other. 3. The lower shield layer (3) is formed in a U-shaped planar shape that branches from an end on the side facing the recording medium to both sides of the back gap (92). The composite thin-film magnetic head according to claim 2.