JPH0756684B2 - Thin film magnetic head - Google Patents

Description

The present invention relates to a thin film magnetic head, and more particularly to a thin film magnetic head of the type in which a magnetic film having a high saturation magnetic flux density is formed on a substrate.

[Outline of Invention]

According to the present invention, in a thin film magnetic head having a lower magnetic film, a first conductor layer, a second conductor layer, an insulating layer, etc. on a substrate, the first conductor layer is not formed at the end of the lower magnetic film and the insulating layer is interposed. By forming a second conductor layer and electrically connecting the second conductor layer, current leakage is prevented and wiring is performed.

[Conventional technology]

Generally, a thin film magnetic head is known as an apparatus for recording an information signal on a magnetic recording medium such as a magnetic tape or a magnetic disk.

In this thin film magnetic head, for example, a lower magnetic film serving as a core material is formed on a ferrite substrate via an insulating layer, and a coil conductor formed of a first conductor layer and a second conductor layer is insulated in an upper region of the lower magnetic film. An upper magnetic film, which is formed via a layer and serves as a core material, is further formed on the coil conductor via an insulating layer.

In such a thin-film magnetic head, an electric signal is transmitted from a bonding portion where the first conductor layer extends as a transmission path of the electric signal to the coil conductor formed of the first conductor layer and the second conductor layer. It is like this. That is, the first conductor layer is formed by depositing a metal such as Cu with a constant thickness on the substrate via an insulating layer and patterning it by ion milling or the like to form a bonding portion and a portion functioning as a coil conductor. Are formed at the same time, and the bonding portion is the extended portion of the coil conductor.

Further, as the thin film magnetic head is made multi-channel and the thin film magnetic head chip is miniaturized, a plurality of thin film magnetic heads are formed corresponding to recording tracks. For this reason, coil conductors are formed corresponding to the number of the thin film magnetic heads, and the bonding portions, which extend the portions functioning as the coil conductors of the first conductor layer, are provided according to the number of the recording tracks. ing.

[Problems to be solved by the invention]

The thin film magnetic head described above has a risk of current leakage and the like.

That is, as shown in FIG. 3, the lower magnetic film 32 formed on the ferrite substrate 31 is formed in a strip shape in order to prevent problems such as warpage and cracks of the substrate during the manufacturing process, and has a sharp edge. It has a portion 32a. Then, on the lower magnetic film 32, an insulating layer 33 for performing interlayer separation and a first conductor layer 34 serving as a coil conductor are laminated.

However, the insulating layer 33 is formed on the end portion 32 of the lower magnetic film 32.
Since "a" shows a steep rise, it cannot be sufficiently adhered at this end portion 32a. Therefore, for example, the film thickness becomes small in the corner portion C, and the first conductor layer 34 formed on the insulating layer 33 and the lower magnetic film 32 are electrically connected to each other to cause current leakage, which is excellent. It hinders magnetic recording. Further, since the end 32a of the lower magnetic film 32 is steep,
There is a possibility that the first conductor layer 34 may be broken at the corners D and the like, and the connection with the bonding portion will be broken.

In addition, as described above, in accordance with the trend toward multi-channel thin film magnetic heads and miniaturization, the end portion of the lower magnetic film 32 is
Even in 32a, the conductor layers connected to a plurality of bonding portions are arranged side by side at a constant interval, but since the end portion 32a is not flat during ion milling, the conductor layer is to be removed. Also, the material forming the conductor layer remains. For this reason, current leakage may occur between the channels, and control of the magnetic head corresponding to each recording track may become impossible.

Therefore, in view of the above problems, it is an object of the present invention to provide a thin film magnetic head that prevents leakage of current at the end of the lower magnetic film and enables good magnetic recording.

[Means for solving problems]

According to the present invention, the lower magnetic film is formed on the substrate,
A thin film magnetic head in which coil conductors each including at least a first conductor layer and a second conductor layer are sequentially formed by interposing a first insulating layer and a second insulating layer, respectively, and an upper magnetic film is further laminated thereon. The lower magnetic layer is formed on a part of the substrate, and the first conductor layer disposed via the first insulating layer is divided in the upper region of the end portion of the lower magnetic film, and the second magnetic layer is formed. The above-mentioned problems are solved by a thin-film magnetic head characterized by being electrically conducted by at least a second conductor layer formed via an insulating layer.

[Action]

In the thin film magnetic head of the present invention, the first conductor layer is not extended in the upper region of the end portion of the lower magnetic film, but is divided in the upper region of the end portion. Then, at least the second conductor layer is formed by mitigating the step difference through the insulating layer. The relief of the step contributes not only to the insulating layer formed between the lower magnetic film and the first conductor layer but also to the insulating layer formed at least between the first conductor layer and the second conductor layer. Therefore, the second conductor layer can be deposited and formed on the flattened region in which the steps are alleviated, and prevents leakage of current to the lower magnetic film, disconnection, leakage of current between channels, and the like. be able to.

〔Example〕

A preferred embodiment of the present invention will be described with reference to FIGS.

The thin film magnetic head of this embodiment is composed of Mn-Zn ferrite and Ni-
A ferrite substrate such as Zn ferrite is used, and for example, a strip of Fe-Al-Si alloy (Sendust) or Fe-Ni is formed on the substrate.
A lower magnetic film made of a ferromagnetic material such as a system alloy (permalloy) is formed as a core material. A coil conductor is formed of a first conductor layer and a second conductor layer on the lower magnetic film with an insulating layer interposed therebetween. The insulating layer also separates the layers between the first conductor layer and the second conductor layer.

As shown in FIG. 1, the first conductor layer 1 extends from the coil conductor corresponding to each channel and is provided in the upper region of the lower magnetic film 8 via an insulating layer (not shown). It is formed up to the end 6 of the lower magnetic film 8. Further, in the region where the lower magnetic film 8 is not formed, the first conductor layers 3 are patterned so as to be connected to or integrated with the bonding portions formed for each channel.
The first conductor layers 1 and 3 are simultaneously patterned by using, for example, a photolithography technique, and have a shape divided by the end portion 6 of the lower magnetic film 8.

Contact portions 4 and 5 are formed in the divided first conductor layer 1 and the first conductor layer 3 in the vicinity of the divided end portions corresponding to the respective channels. Then, the second conductor layer 2 is patterned so as to connect the contact portion 4 formed on the first conductor layer 1 and the contact portion 5 formed on the first conductor layer 3 for each channel. ing.

In the region where the second conductor layer 2 that connects the contact portions 4 and 5 is patterned, the steps of the end portion 6 of the lower magnetic film 8 are alleviated and flattened by a plurality of insulating layers, as described later. It has become an area. Therefore, the second conductor layer prevents adverse effects such as current leakage and prevents the first conductor layer 1 and the first conductor layer from
The conductor layer 3 can be electrically connected. The second conductor layer 2, like the first conductor layers 1 and 3, is also formed and patterned at the same time as the coil conductor portion (not shown). Has a function of exciting the lower magnetic film 8 and the like which are core materials.

In the thin film magnetic head having the structure at the end portion 6 of the lower magnetic film 8 as described above, the step difference is mitigated at the end portion 6, so it is possible to prevent adverse effects such as current leakage.

That is, the structure of the end portion 6 will be described in detail with reference to FIG. 2. First, the lower magnetic film 8 which is deposited and patterned on the substrate 7 by, for example, the sputtering method.
Is formed to have an end portion 6 on a part of the substrate 7 in order to reduce cutting of each chip and alleviate warpage of the substrate. A first insulating layer 9 is formed on the entire surface of the substrate 7 having the lower magnetic film 8 patterned. On the first insulating layer 9,
The first conductor layer 1 and the first conductor layer 3 are divided and patterned in the upper region of the end portion 6 of the lower magnetic film 8.
Therefore, the film thickness of the first insulating layer 9 is, for example, lower magnetic film 8.
Even if the corner portion A is thinned, it is possible to prevent a phenomenon such as a short circuit between the lower magnetic film 8 and the first conductor layer 1 at the corner portion A or the like.

Next, the second conductor layer 2 for connecting the first conductor layers 1 and 3 divided at the end 6 is formed in a pattern. In this case, the second conductor layer 2 is the second insulating layer 10. Since the first conductor layers 1 and 3 are adhered and formed on the upper portion, the first conductor layers 1 and 3 can be connected without adversely affecting the step of the end portion 6. That is, the second conductor layer 2 connected to the first conductor layers 1 and 3 via the contact portions 4 and 5 has the first insulating layer 9 at the end portion 6 of the lower magnetic film 8.
And deposited on the second insulating layer 10. Therefore, the first insulating layer 9 and the second insulating layer 10 cover the lower magnetic film 8 with a sufficiently thick film thickness, so that the lower magnetic film 8 and the second conductor layer 2 are electrically connected. There is no fear. Similarly, the step 6 is relaxed at the end portion 6 by the first insulating layer 9 and the second insulating layer 10, and the second conductor layer 2 is deposited and formed in the region where the step is relaxed. . Therefore, during pattern etching, it is possible to effectively remove the second conductor layer 2 even at a step portion, and for example, pattern formation corresponding to each channel can be performed without conduction between each channel. . Further, since the steps are alleviated, there is no risk of step breakage at the corners B and the like of the second conductor layer 2 and reliable electrical connection can be achieved.

As described above, the thin film magnetic head of the present embodiment alleviates the step difference of the end portion 6 of the lower magnetic film 8 formed on a part of the substrate 7, so that adverse effects such as current leakage can be prevented.

Incidentally, in the above-mentioned embodiment, the steps are alleviated by the first conductor layer and the second conductor layer and the insulating layer, but more steps are made by laminating more conductor layers and insulating layers. Good.

〔The invention's effect〕

In the thin film magnetic head of the present invention, since the step at the end of the lower magnetic film is relaxed and the electrical connection is made by the second conductor layer or the like,
It is possible to prevent current leakage and disconnection between the lower magnetic film and the conductor layer, and further prevent current leakage between channels. Therefore, good magnetic recording can be performed.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a thin film magnetic head according to the present invention, FIG. 2 is a sectional view taken along the line II ′ of FIG. 1, and FIG. 3 is a conventional thin film magnetic head. It is a schematic sectional drawing. 1 ... First conductor layer 2 ... Second conductor layer 3 ... First conductor layer 4,5 ... Contact part 6 ... End 7 ... Substrate 8 ... Lower magnetic film 9 ... First insulating layer 10 …… Second insulating layer

Claims (1)

[Claims] 1. A lower magnetic film is formed on a substrate, and a coil conductor including at least a first conductor layer and a second conductor layer is sequentially laminated and formed via a first insulating layer and a second insulating layer, respectively. Further, in a thin film magnetic head having an upper magnetic film laminated thereon, the lower magnetic layer is formed on a part of the substrate,
In the upper region of the end portion of the lower magnetic film, the first conductor layer arranged via the first insulating layer is divided, and is electrically connected by at least the second conductor layer formed via the second insulating layer. A thin film magnetic head characterized in that