JP3231510B2 - Magnetic head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film magnetoresistive head used for a hard disk as a high density recording device.

[0002]

2. Description of the Related Art In recent years, there has been a demand for miniaturization and high capacity of a hard disk in accordance with high performance of a computer. In particular, with the miniaturization, the speed of a recording medium has been reduced.
Therefore, when reading data from a magnetic disk, the need for a thin film magnetoresistive head (hereinafter referred to as a thin film MR head) whose signal output does not depend on the speed with a recording medium has been increasing. This thin-film MR head is a so-called composite thin-film magnetic head using a conventional inductive type thin-film head as a recording-only head and a thin-film magnetoresistive element as a reproduction-only head. In the thin-film MR head, since the thin-film magnetoresistive element is used as a read-only head, the read output does not depend on the relative speed with respect to the recording medium. In principle, data can be read even at a low speed of the recording medium. .

In the structure of the above-mentioned thin film MR type head, three types are proposed depending on the position of the thin film magnetoresistive element. One is a yoke type in which a thin-film magnetoresistive element is formed in a part of a magnetic circuit of a recording-only head. The other is an in-gap type in which a thin-film magnetoresistive element is formed between air gaps of a recording-only head. No. 3 is a piggyback type in which a recording-only head is formed on a thin-film magnetoresistive element formed thereon. In recent years, the piggyback type 3 is the mainstream of thin-film MR heads for fixed disks. There are a center element type in which the entire head is arranged at the center of the slider and a side element type in which the entire head is arranged at the end of the slider. The center element type head has a characteristic that the flying characteristics are stable. However, with the idea that the side element type is advantageous for recording more efficiently on the recording surface of the medium with the miniaturization of the hard disk, the side element type is becoming mainstream in recent years. Further, there is a tendency that the size of the slider is reduced in order to increase the capacity. Originally, the standard dimensions for hard disks are width 3.
The size is 18 mm x 0.86 mm in height x 4.04 mm in length, but 70% or 50% of the standard dimensions have come out with the increase in capacity.

FIG. 3 is a pattern diagram of a conventional thin film MR type head. In the figure, 1 is a ceramic substrate, 3 is a magnetoresistive element, 4 is an MR lead, 5 is an MR contact hole, 6 is an MR lead lead wire which is a lead wire of an extraction electrode portion,
10 is a coil, 12 is a coil lead wire.

[0005]

SUMMARY OF THE INVENTION In a thin film MR type head,
Since the lead wire of the lead electrode portion of the thin film magnetoresistive element portion and the lead wire of the coil of the recording-only head are formed, lead routing becomes a problem as the size of the slider decreases. For example, in order to route the lead wire of a thin film magnetoresistive element and the lead wire of a recording-only head without overlapping,
It is necessary to reduce the width of the lead wire or increase the length of the lead wire. However, if the width of the lead wire is reduced or the length of the lead wire is lengthened, the overall resistance increases and causes DCR noise. That is, in FIG. 3, in order to arrange the MR lead routing wire 6 and the coil lead routing wire 12, which are the lead wires, in a limited space, the width of the lead wire is reduced, the resistance is increased, and the cause of DCR noise is increased. That is,

In order to solve these problems, attempts have been made to increase the thickness of the lead wire. However, there is a problem that the process for forming the lead wire is complicated. In addition, there is a limit in reducing the width of the lead wire or increasing the length of the lead wire. When the slider dimension is less than 50% of the standard dimension, it becomes substantially difficult to lead the lead.

The present invention solves the above-mentioned conventional problems,
An object of the present invention is to provide a highly reliable thin-film MR head with little reproduction noise by a simple process.

[0008]

SUMMARY OF THE INVENTION Accordingly, a thin film MR of the present invention is provided.
The type head has a structure in which at least a part of a lead wire of a coil of a recording-only head is overlapped, and a part of a lead wire of an extraction electrode portion of a thin-film magnetoresistive element part and a part of a lead of a coil of a recording-only head are overlapped. It has a structure in which a part of a lead wire of an extraction electrode portion of a thin film magnetoresistive element portion is overlapped.

[0009]

According to the above construction, by overlapping the lead wires, the width of the lead wires can be increased as much as possible in a limited space to reduce the resistance, and a highly reliable thin film MR head with less noise can be obtained. Obtainable.

[0010]

Next, an embodiment of the present invention will be described with reference to the drawings. 1A, 1B, 1C, and 1D are pattern diagrams of a thin-film MR head according to one embodiment of the present invention. In the figure, 1 is a ceramic substrate, 2 is a lower shield,
3 is a magnetoresistive element, 4 is an MR lead, 5 is an MR contact hole, 6 is an MR lead routing line, 7 is an upper shield, 8 is a lower core as a lower magnetic layer, 9 is a back gap through hole, 10 is a coil, 11 Denotes an upper core as an upper magnetic layer, 12 denotes a coil lead wiring, and 13 denotes a pad. As shown in the drawing, each of the MR lead routing wire 6 and the coil lead routing wire 12 of each embodiment is formed by overlapping a plurality of wires, and thus, the coil lead routing wire is limited in a limited space. The width of the line 12 is made as large as possible to reduce its resistance. The lower shield 2, the magnetoresistive element 3, the MR lead 4, the MR contact hole 5, the MR lead routing line 6, and the upper shield 7 constitute a read-only head.
A recording-only head is formed by the lower core 8, the back gap through hole 9, the coil 10, the upper core 11, and the coil lead wire 12.

Next, the steps of forming the thin-film MR type head shown in FIG. FIG. 2 is a process chart for forming a thin film MR type head according to one embodiment of the present invention. FIG.
In (a), a ceramic substrate 1 called Altic made of Al ₂ O ₃ and TiC conventionally used for a thin-film inductive head is used. First, after the surface of the substrate 1 is finished and polished, an insulating material such as alumina is formed to a thickness of, for example, 4 μm by a method such as sputtering or physical vapor deposition.
Next, after forming the lower read gap of the read head at 2000 A using alumina or the like, a soft magnetic bias auxiliary layer is formed at 500 A, for example, a nonmagnetic layer Ta is formed at 100 A thereon, and a permalloy MR3 is formed at 450 A. Next, a photoresist is applied to the whole, and the rectangular shape of the magnetoresistive element 3 is patterned. This is formed into a rectangular shape by ion milling. On this, an exchange bias layer for controlling Barkhausen noise and the like is formed.

On top of this, an MR lead 4 is patterned with a photoresist (FIG. 2B), and Ti, Ta, Cu
Alternatively, a material such as a Cu alloy, W, Cr, Mo, or Au is formed to 1200 A by sputtering or vapor deposition, and then lifted off to form the shape of the MR lead 4.

Next, for example, 2000 A is formed on the alumina film of the upper read gap layer while applying an appropriate bias. The bias sputtering is performed while applying an RF bias to the ceramic substrate 1 using a conventional sputtering apparatus. When the bias voltage applied to the substrate is less than -100 V, the flattening effect is small. When the applied bias voltage is -100 V or more, the internal stress of the alumina film becomes large, and the magnetization of the magnetoresistive element 3 is disturbed. Next, an MR contact hole 5 is formed in the upper read gap layer, and a contact is made with the MR lead routing line 6 (FIG. 2).
(C)). By forming the upper shield 7 thereon by NiFe plating, a read-only head is formed. Next, the lower core 8 is similarly formed by NiFe plating (FIG. 2D). Next, an alumina film, which is a material for the magnetic gap, is formed to a thickness of, for example, 0.6 μm by a conventional bias sputtering apparatus. Then, a back contact pattern is formed by a resist in order to form a hole for the back contact, and a hole is formed in the magnetic gap layer by milling. Thereafter, a resist is applied as a first insulating layer, which is patterned and baked. A copper coil 10 is formed thereon by a chemical plating method using a copper base electrode (FIG. 2E). This coil is formed with a predetermined number of turns which turns a magnetic circuit through both magnetic layers of the lower core 8 and the upper core 11. Then, a second insulating layer is formed again with a resist. Thereafter, a second insulating layer is formed in the same manner as the first insulating layer, and the upper core 11 is formed thereon by NiFe plating (FIG. 2 (f)). The recording-only head is formed as described above. At this time, the coil lead wire 12 is also formed at the same time, but the MR lead wire 6 of the lead electrode portion of the thin film magnetoresistive element portion and a part of the coil lead wire 12 of the recording-only head are formed in an overlapping pattern. Thereafter, a Cu pad 13 is formed, and a protective layer is formed of alumina to form a thin-film magnetic head. FIG.
(B) A pattern of a structure in which part of the coil lead routing lines 12 of the recording-only head shown in (c) are overlapped, and an MR lead routing line of the extraction electrode portion of the thin film magnetoresistive element shown in FIG. 6 can be formed by the same method as the method shown in FIG.

A comparison between the patterns according to the embodiments of the present invention shown in FIGS. 1A and 1B and the patterns of the conventional example shown in FIG. 3 shows that the former is an MR lead lead wire 6 or a coil lead lead wire 12 which is a lead wire. Are superimposed, the width can be made as large as possible in the limited space as compared with the conventional example, and it is not necessary to extend the wiring. On the other hand, in the latter, since the lead wires do not overlap, it is necessary to reduce the width of the lead wire, and the resistance increases.

[0015]

As described above, the present invention has a structure in which at least a part of the lead wire of the coil of the recording head is overlapped, the lead wire of the lead electrode of the film magnetoresistive element portion and the coil of the recording head. By adopting a structure in which a part of the lead wire is overlapped, or a structure in which a part of the lead wire of the extraction electrode part of the thin film magnetoresistive element part is overlapped, the resistance can be reduced without reducing the width of the lead wire. A highly reliable thin-film MR head with little reproduction noise can be obtained by a simpler process than the conventional method.

[Brief description of the drawings]

1A is a pattern diagram of a thin-film MR head according to one embodiment of the present invention; FIG. 1B is a pattern diagram of a thin-film MR head according to one embodiment of the present invention; (D) is a pattern diagram of a thin-film MR head according to an embodiment of the present invention.

FIG. 2A is a view showing a process of forming a thin-film MR head according to one embodiment of the present invention; FIG. 2B is a view showing a process of forming a thin-film MR head according to one embodiment of the present invention; FIG. 4D is a diagram illustrating a process of forming a thin film MR head according to an embodiment of the present invention. FIG. 5E is a diagram illustrating a process of forming a thin film MR head according to an embodiment of the present invention. f) is a process diagram of forming a thin film MR type head according to one embodiment of the present invention.

FIG. 3 is a pattern diagram of a conventional thin film MR type head.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 ceramic substrate 2 lower shield 3 magnetoresistive element 4 MR lead 5 MR contact hole 6 MR lead lead wire 7 upper shield 8 lower core 9 back gap through hole 10 coil 11 upper core 12 coil lead lead wire 13 pad

Claims (1)

(57) [Claims] A lead portion and a pad portion formed of a thin film ;
And having two recording heads are formed by a thin film magnetoresistive element, and a read-only head having two lead portions and pad portions is formed in one on complexed slider, 4 recruited
A magnetic head having a over de portion and the pad portion, while at least the superposed portions of the leads and the leads of the read-only head the recording head structure, are disposed in each of the leads 4 A magnetic head, wherein two pad portions are arranged along a width direction of the slider.