JPH0351770Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to a method of manufacturing a thin film magnetic head for R/W of magnetic recording devices such as DATs and computers, and particularly relates to a technology for forming conductive coils thereof.

BACKGROUND TECHNOLOGY In DAT (Digital Audio Tape Recorder), which has been attracting attention recently, the linear recording density on magnetic tape is approaching its limit. This is due to the fact that the DAT magnetic head is a bulk core. Therefore, thin film heads have begun to be used regularly in place of bulk heads in DATs and the like.

That is, as shown in FIGS. 8 and 9, thin film heads generally have a nonmagnetic thin film 2 formed on a ferrite or other ferromagnetic substrate 1 serving as a lower core to form a magnetic gap g. Then, on the thin film 2, a conductive coil pattern 3 is formed, for example, in a spiral shape, and the conductive coil pattern 3 is directly bonded to the substrate 1 through an insulating layer 4 other than the thin film 2.
It has a ferromagnetic thin film 5 which becomes an upper core and interlinks with the upper core. The lead-out lead 7 connected to the terminal end 6 located at the spiral center of the conductive coil pattern 3 and led out to the outside is also structured to similarly ride on the conductive coil pattern 3 via the insulating layer 4.

In this way, in order to insulate the ferromagnetic thin film 5 and the lead-out leads 7 from the conductive coil pattern 3 and the insulating layer 4 well, a technique for flattening the upper surface of the insulating layer 4 is required. Therefore, conventionally, when a recess is formed due to riding on the insulating layer 4, it is filled with, for example, polyimide resin.
However, this method has drawbacks such as increased cost, and therefore, recently, a technique has been promoted in which when unevenness occurs on the upper surface of the insulating layer 4, the unevenness is eliminated by bias sputtering.

Problems to be Solved by the Invention However, there are the following unresolved problems in flattening the insulating layer of the thin film magnetic head described above. The problem is that if bias sputtering is simply performed on the upper surface of the insulating layer 4, the width of the convex portion of the insulating layer 4 will naturally increase in areas where the pattern width is wide, such as the upper part of the terminal end 6 of the conductive coil 3. It also becomes wider, so
This increases the number of man-hours required to eliminate the protrusions. Moreover, even when attempting to provide a contact hole by etching or the like after bias sputtering, if an attempt is made to obtain an insulating layer 4 with a sufficient thickness for insulation even if the convex portion disappears, A thicker layer than necessary had to be formed, which also had the disadvantage of increasing the number of etching steps.

Means for solving the problem In order to solve the above problem, this invention has a non-magnetic thin film on the ferromagnetic substrate which becomes the lower core.
In a so-called inductive thin film head, a conductive coil pattern and a ferromagnetic thin film serving as an upper core are laminated and a magnetic gap is formed between a ferromagnetic substrate and a ferromagnetic thin film. It is characterized in that the terminal end connected to the lead is set in a comb shape with a tooth width that is approximately equal to the width of the middle part of the coil pattern. In other words, this idea has the intention of thoroughly achieving flattening by bias sputtering by devising the terminal portion.

Effect According to this invention, since the end portion of the conductive coil pattern is set in a comb shape, the width dimension of the comb-shaped convex portion of the insulating layer covering the end portion is approximately the width dimension of the middle portion of the conductive coil pattern. Therefore, even if the upper surface of the insulating layer is subjected to bias sputtering, the convex portions are removed at a uniform speed over the entire area of the conductive coil pattern. Further, the flattening film thickness of the insulating layer covering the conductive coil pattern can be formed uniformly and to the minimum necessary level.

Embodiment FIGS. 1 and 2 are a plan view of an inductive R/W thin film head showing an embodiment of this invention, and FIG.
8 and 9, which show conventional heads, are given the same reference numbers. In the thin film magnetic head of this embodiment, the winding end portion 8 located at the center of the conductive coil pattern 3 formed in a spiral shape is formed in a comb shape with a face width dimension equal to the width dimension a of the pattern midway portion 3'. ing. The advantages resulting from forming the termination portion 8 in this manner will be explained below with reference to the manufacturing process.

First, as shown in FIG. 3 and FIG. 4 showing a cross section taken along the - line, a non-magnetic thin film 2 of Al ₂ O ₃ is deposited on a Mn--Zn ferrite substrate 1 with a magnetic gap g.
A spiral conductive coil pattern 3 is formed to have a thickness approximately equal to the gap length of the spiral conductive coil pattern 3, and has a comb-shaped end portion 8. Here, in the central part surrounded by the conductive coil pattern 3 and near the termination part 8, a window part 9 is opened to expose the bare surface of the ferrite in order to magnetically connect the upper core to the substrate 1 which is the lower core. There is. Next, as shown in FIG. 5, a thin film of SiO ₂ , for example, is deposited as the coil insulating layer 4 .
The upper surface of this SiO ₂ thin film 4 is an uneven surface with convex portions corresponding to the conductive coil pattern 3. Then, as shown in FIG. 6, the protrusions on the top surface of the SiO ₂ thin film 4 are removed and flattened by PR bias sputtering. That is, using a PR magnetron sputtering device, a negative bias voltage is applied to the substrate 1, and the substrate 1 is sputtered as a target material.
SiO ₂ is set, and the convex portions indicated by broken lines 10 are physically removed by etching. The principle of bias sputtering is well known, but it will be briefly explained as follows. First, Ar gas is introduced as an inert gas into the PR magnetron sputtering device, and when an RF voltage is applied that makes the substrate 1 a negative potential, the Ar gas is ionized and once the SiO ₂ target in the sputtering device is released. incident on the
It is etched and deposited on the SiO ₂ thin film 4. However, since Ar ions are also incident on the SiO ₂ thin film 4, the convex portion 10 is sputtered and etched away again. At this time, the bias sputtering speed is proportional to the width dimension a' of the convex part 10, so the face width dimension a of the terminal end part 8 is
In order to completely remove the SiO ₂ thin film, it is preferable to set the dimension a″ so that a″<a′.
After that, as shown in Fig. 7, the SiO ₂ thin film on the terminal part 8 is
Etching is performed with an acid such as HF to expose the comb-shaped terminal end 8', and as shown in FIGS. 1 and 2, the lead-out leads 7 are formed to form a magnetic head.

Effects of the Idea By implementing this idea, the problem that conventionally required a large amount of man-hours to flatten the insulating layer using bias sputtering due to its wide width can be improved, and the thickness of the insulating layer can be reduced to a minimum. It is possible to reduce man-hours and improve manufacturing yield at the same time. Furthermore, since this invention eliminates the need for resin embedding and flattening, which has been done in the past, it naturally contributes to cost reduction. It is also stable at high temperatures during glass bonding and annealing, providing flexibility in process design.

[Brief explanation of the drawing]

1 and 2 are a plan view and a cross-sectional view taken along the - line of a thin film magnetic head showing an embodiment of this invention. FIGS. 3 to 7 are plan views or cross-sectional views of the thin film magnetic head in each manufacturing process. 8 and 9 are a plan view and a cross-sectional view taken along the - line of a conventional thin film magnetic head. DESCRIPTION OF SYMBOLS 1...Substrate, 2...Nonmagnetic thin film, 3...Conductive coil pattern, 4...Insulating layer, 5...Ferromagnetic film, 8...Terminal part, g...Magnetic gap.

Claims (1)

[Claims for Utility Model Registration] A non-magnetic thin film, a conductive coil pattern, an insulating layer, and a ferromagnetic thin film that becomes the upper core are laminated on a ferromagnetic substrate that becomes the lower core, and the ferromagnetic material In a magnetic head that forms a magnetic gap between a substrate and a ferromagnetic thin film, the terminal end of the conductive coil pattern connected to the external lead is connected to a comb having a face width approximately equal to the width of the middle part of the coil pattern. A thin film magnetic head characterized by its shape.