JPH01108709A - Thin film coil and manufacture thereof - Google Patents

Abstract

PURPOSE:To avoid discontinuity of the connection part between a lower layer coil conductor and an upper layer coil conductor by a method wherein a 1st coil conductor is electrically connected to a 2nd coil conductor by an interconnection conductor instead of forming holes in insulating layers. CONSTITUTION:A lower layer coil conductor 14 is formed on a lower magnetic layer 12 formed on a nonmagnetic substrate 11 with an insulating layer 13 between. Further, intermediate magnetic layers 15 and 16 are formed on the lower layer coil conductor 14 and the lower magnetic layer 12. The intermediate magnetic layer 16 is used as an interconnection conductor which connects the lower layer coil conductor 14 to an upper layer coil conductor 19 electrically. An insulating layer 17 is formed on the lower layer coil conductor 14 and the intermediate magnetic layers 15 and 16. Than the insulating layer 17 is polished to have a flat surface until the intermediate layers 15 and 16 are exposed to the surface. Thus the upper surfaces of the intermediate magnetic layers 15 and 16 and the insulating layer 17 are uniformly levelled and the upper layer coil conductor 19 is formed on the levelled surface 18. At that time, the upper layer coil conductor 19 is connected to the lower layer coil conductor 14 by the intermediate magnetic layer 16.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a thin film coil in a thin film magnetic head used for recording and reproducing magnetic recording media.

2. Description of the Related Art An example of a thin film coil in a conventionally known thin film magnetic head will be described with reference to FIGS. 3 and 4. 3 and 4, a lower magnetic layer 2 is formed on a non-magnetic substrate 1, a lower coil conductor 4 is formed on the lower magnetic layer 2 with an insulating layer 3 interposed therebetween, and the lower coil conductor 4 is An upper coil conductor 6 is formed thereon with an insulating layer 5 interposed therebetween, and an upper magnetic M8 is laminated on the upper coil conductor 6 with an insulating layer 7 interposed therebetween.

Here, the upper surfaces of the insulating layer 5 and the insulating layer 7 are flattened.
This prevents disconnection of the upper coil conductor 6 and deterioration of the characteristics of the upper magnetic layer 8 due to the step. The insulating layer 5.7 can be flattened by coating a photoresist or polyimide resin as an insulating layer, or by coating a photoresist after forming silicon dioxide (SiO□) as an insulating layer, and then using ion milling to form a photoresist or a polyimide resin. , how to flatten remove (
This is done using the etch-back method).

Further, the lower coil conductor 4 and the upper coil conductor 6 are electrically connected through a hole 9 formed in the insulating layer 5 prior to the formation of the upper coil conductor 6.

The problem that the invention aims to solve However, in the formation of conventional thin film coils.

The method for flattening the insulating layers 5 and 7 described above makes it difficult to obtain a sufficiently flat surface and is insufficient in terms of reproducibility. There was a problem in that the upper layer coil conductor 6 could be disconnected at the stepped portion of the hole 9 of the insulating layer 5 that was drilled for this purpose.The present invention solves the above problem, and It is an object of the present invention to provide a thin film coil and a method for manufacturing the same in which there is no fear of disconnection of the connection portion of the upper layer coil conductor.

Means for Solving the Problems The present invention solves the above problems by
a coil conductor and a second coil conductor.

The first coil conductor and the second coil conductor are electrically connected by a connecting conductor embedded in an insulating layer between the first coil conductor and the second coil conductor.

The manufacturing method is after forming the first coil conductor.

After forming a connecting conductor that is electrically connected to the first coil conductor at the connection part with the second coil conductor on the first coil conductor and covering it with an insulating layer: After polishing the connecting conductor The insulating layer is removed and planarized until the insulating layer is no longer present, and a second coil conductor, a part of which is electrically connected to the connection conductor, is formed on this insulating layer.

Effects According to the above configuration, the first coil conductor and the second coil conductor are electrically connected by the connecting conductor, so that
It is no longer necessary to make a hole in the insulating layer between the first coil conductor and the second coil conductor as in the conventional case, and there is no possibility that the second coil conductor will be disconnected at the stepped portion of the hole. In addition, since the insulating layer is flattened by polishing until the top surface of the connection conductor is exposed, the flatness is superior to that of conventional flattening methods such as etch-back methods. There is no difference in level between the upper surface of the connecting conductor and the second coil conductor.

Example Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a plan view of a thin film coil of the present invention in a thin film magnetic head, and FIG. 2 is a sectional view taken along line AA' in FIG. 1st
In the figure and FIG. 2, a lower magnetic layer 12 made of an amorphous alloy is formed on a non-magnetic substrate 11 to a thickness of 10 μ-.
A lower coil conductor 14 made of aluminum An is formed by photoetching to a thickness of 2 .mu.m via an insulating layer 13 made of aluminum. Further, intermediate magnetic layers 15 and 16 made of an amorphous alloy are formed on the lower coil conductor 14 and the lower magnetic layer 12 to a thickness of 6 μI by a lift-off method.

In this embodiment, the intermediate magnetic layer 16 serves as a connection conductor that electrically connects the lower coil conductor 14 and an upper coil conductor 19, which will be described later. Then, an insulating layer 17 made of alumina AM, O, is formed on the lower coil conductor 14 and the intermediate magnetic layer 15, 16, and then the insulating layer 17 is polished flat until the intermediate magnetic layer 15, 16 is exposed at the surface. , insulating layer 17
The upper surfaces of the intermediate magnetic layers 15 and 16 are planarized, and an upper layer coil conductor 19 made of aluminum A is formed on the planarized surface 18 to a thickness of 2 μm by photoetching. At this time, the upper layer coil conductor 19 is connected to the lower layer coil conductor 1.
4 through the intermediate magnetic layer 16.

The above-mentioned etch-back method is also available as a means of flattening, but in order to obtain a good flattened surface 18 using this method,
It is necessary to make the etching rates of the resin such as photoresist applied on the insulating layer 17, the insulating layer 17, and the intermediate magnetic layers 15, 16 by ion milling approximately equal, which is practically difficult. - On the other hand, with polishing, there is little difference in polishing speed between different materials, a good flattened surface 18 can be easily obtained, and the upper surface of the intermediate magnetic layer 16 and the upper layer coil conductor 19 are
It is possible to eliminate the difference between the two.

Next, the intermediate magnetic layer 20 of an amorphous alloy is applied to the intermediate magnetic layer 1.
5 is formed by a lift-off method, and then an insulating layer 21 with a Δ vertical height 203 is formed, and the insulating layer 21 is again planarized and polished.
A gap layer 23 made of n, is formed by photoetching, and an upper magnetic layer 24 made of an amorphous alloy is formed by
is formed by photo-etching to a thickness of 5 μm.

In the thin film magnetic head manufactured in this manner, there is no hole in the insulating layer 17 for connecting the lower layer coil conductor 14 and the upper layer coil conductor 19, so there is a disconnection of the upper layer coil conductor 19 at the stepped portion of this hole. does not occur at all.

Although the above embodiments have been explained using a thin film magnetic head as an example, the present invention is also effective for other devices and apparatuses in which thin film coils are widely used. In addition, in the above embodiment, explanation was given by taking a two-layer thin film coil as an example, but three
The present invention is also effective for thin film coils having more than one layer.

Effects of the Invention According to the present invention, the first coil conductor and the second coil conductor are electrically connected by the connecting conductor instead of making a hole in the insulating layer. This completely eliminates the possibility of disconnection of the second coil conductor. In addition, by flattening the insulating layer by polishing, the upper surface of the connecting conductor is formed, which eliminates the level difference between the connecting conductor and the second coil conductor, and further simplifies the process. and is practically useful.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a thin film coil in a thin film magnetic head showing an embodiment of the present invention, FIG. 2 is a sectional view taken along line AA' in FIG. 1, and FIG. 3 is a plan view of a thin film coil in a conventional thin film magnetic head. The plan view and FIG. 4 are BB' cross-sectional views of FIG. 3. 14... Lower layer coil conductor, 16... Intermediate magnetic layer, 1
7... Insulating layer, 18... Flattened surface, 19... Upper layer coil conductor. Agent Yoshihiro MorimotoFigure 3

Claims (2)

[Claims] 1. A thin film coil in which a plurality of layers of coil conductors are laminated with an insulating layer interposed in between, the surface forming the coil conductor is formed flat, and the adjacent first coil conductor and second coil conductor are A thin film coil electrically connected by a connecting conductor formed in the insulating layer between the first coil conductor and the second coil conductor. 2. A thin film coil formed by laminating multiple layers of coil conductors with an insulating layer interposed therebetween, comprising: i. forming a first coil conductor; ii. forming a connecting conductor electrically connected to the first coil conductor at a connecting portion of the first coil conductor with the second coil conductor; iii. covering the first coil conductor and the connection conductor with an insulating layer; iv. removing and planarizing the insulating layer by polishing until the insulating layer on the connecting conductor is removed; v. forming a second coil conductor on the insulating layer corresponding to the first coil conductor, a part of which is electrically connected to the connection conductor; How to manufacture coils.