JPS58179922A - Production of electrode of thin film magnetic head - Google Patents

Abstract

PURPOSE:To eliminate defects including cavities, etc. and to prevent corrosion when an electrode is formed concurrently with formation of a thin film magnetic head, by deleting the overhang part of a conductor film formed by electroforming with a taper etching process and then forming a protecting film. CONSTITUTION:An electrode lead-out conductor 2, the 1st protecting film 3, a conducting foundation film 4 and a photoresist 5 are formed on a wafer 1. Then a copper conductor 6 is formed by means of a copper sulfate plating solution, etc. for example. A photoresist 10 is patterned for taper etching of the conductor 6. Then an alkaline etching solution of chloric acid, etc. is used to give taper etching to the conductor 6. Thus an overhang area on the resist 5 is completely deleted, and the edge part of the conductor 6 is etched with 30- 40 deg. inclination angle. Then the film 5 is deleted, and an inorganic protecting film 7 is formed. The mechanical processing is applied to the surface of the film 7 to expose an electrode part 6. In sucg a way, an electrode part having high resistance to corrosion is obtained without producing cavities between the film 3 and the electrode 6 as well as crevasses between the electrode 6 and the film 7.

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention The present invention relates to a method for manufacturing electrodes of a thin film magnetic head, and more particularly to a method for manufacturing electrodes that are formed simultaneously with the formation of a thin film magnetic head.

BACKGROUND TECHNOLOGY Generally, a thin film magnetic head formed by thin film technology is composed of a base phenol-1, a magnetic head element 10 and an electrode 20 provided on the wafer 1, as shown in FIG. There is. The electrode 20 is connected to the magnetic head element 10.
It is formed by thin film technology at the same time as the formation of the terminal, and is used to establish electrical conduction between external terminals.

A method of manufacturing the electrode 20 according to the prior art will be explained with reference to FIG. FIGS. 2(a) to 2(C) are cross-sectional views of an electrode showing the manufacturing process of the electrode according to the prior art. In this manufacturing method, first, a conductor 2 for leading out an electrode from a magnetic head element is formed on a wafer 1, as shown in FIG. 1(a). Next, a first protective film 5 is formed to protect the magnetic head element from acidic or alkaline chemicals used during electroforming. Next, after forming a copper film 4, which will serve as a base for current conduction during electroforming, by vacuum evaporation or sputtering, a photoresist 5 is formed to a thickness of 2 to 10 am, and patterned to a predetermined size. Next, a metal conductor 6 having a thickness of 20 to 40 μm is formed by electroforming using a steel or nickel plating solution that can stably form a thick film. In this case, the shape of the conductor 6 is formed to follow the patterning shape of the photoresist 5 until the thickness of the conductor 6 is approximately the same as the thickness of the photoresist 5. However, when the conductor 6 is formed thicker than the photoresist 5, the conductor 6 is deposited not only in the film thickness direction but also in the lateral direction perpendicular to the film thickness direction, which is a characteristic of electroplating. The precipitation of occurs as shown in FIG. 1(a). This lateral deposition progresses at a ratio of approximately 1:1 to the deposition in the film thickness direction, and when a 20-40 μm conductor 6 is formed by electroforming, a 10-50 μm thick conductor 6 is formed by electroforming. will occur. When the photoresist 5 is removed, a gap equivalent to the thickness of the photoresist film will be created under the outer ring portion. As shown in FIG. 1(b), if the inorganic protective film 7 is subsequently formed by vacuum evaporation or snobbing, the gap under the overhang cannot be filled, and the inorganic protective film 7 around the conductor 6 cannot be filled. A cavity 8 and a freflux 9 result. This defect appears around the electrode when the surface of the inorganic protective film 7 is machined to expose the conductor 6 as shown in FIG. 1(C), resulting in a decrease in reliability in terms of corrosion resistance. It is the cause.

As described above, the conventional method for manufacturing thin film magnetic head electrodes has the problem of lowering reliability in terms of corrosion resistance.

OBJECTS OF THE INVENTION An object of the present invention is to eliminate the above-mentioned problems caused by the prior art, and to prevent the occurrence of cavities or fringes.
An object of the present invention is to provide a method for manufacturing an electrode for a thin film magnetic head with excellent corrosion resistance.

In order to achieve the above object, the present invention is characterized in that the protective film is formed after the overhanging portion of the conductive film formed by electroforming is removed by performing taper etching. .

Embodiment of the Invention The manufacturing method according to this embodiment, as shown in FIG. 1(a), is carried out in the same manner as the electrode part forming method according to the prior art up to the formation of the conductor 6. On top of the wafer 1, a conductor 2 for leading out the electrode
, the first protective film 3, the current-carrying base film 4, and the photoresist 5 are formed to have predetermined dimensions. After that, the electroforming method, which is easy to thicken the film, is used, for example, sulfuric acid steel 220g/l,
A copper conductor 6 is formed using a sulfuric acid steel plating solution containing 75 g/l of sulfuric acid. Next, in order to perform taper etching of the conductor 6, which is a feature of the present invention, a photoresist 10 for etching is patterned on the copper conductor 6. At this time, the photoresist 5 is left without being removed and has the function of protecting the magnetic head element from the etching solution. Next, the copper conductor 1 is etched using an alkaline etching solution of chlorate or persulfate by dipping or electrolysis. In this case, the larger the difference between the patterning dimension of the protective film 3 of the butterfly 1 and the patterning dimension of the photoresist 5, the easier the etching becomes. The etching end point is the time when the copper conductor 6 is etched and the end of the photoresist 5 is calculated or the copper of the current-carrying base film 4 is dissolved. As a result, the overhang part of the copper conductor 6 is completely removed and the end of the copper conductor 6 is
It can be etched to a 0 degree tilt angle. When the conductor 6 of the thin film magnetic head electrode part having the structure as in this example is formed, after removing the photoresist 5 and the etching photoresist 10, an inorganic protective layer is formed as shown in FIG. 1(0). When the inclination angle of the conductor 6 is 40 degrees or less, the film 7 has sufficient step coverage and can be formed without defects. Even when the surface of this inorganic protective film 70 is machined as shown in FIG. 1(d), defects such as cavities and flavours do not occur, so that an electrode portion with good corrosion resistance can be formed.

Effects of the Invention As described above, according to the present invention, which is characterized in that after forming the conductive film of the electrode portion of a thin film magnetic head by electro-7 ohming, only the overhanging portion of the conductive film is tapered etched. The corrosion of the magnetic head element during etching can be prevented. 5 conductor films
By etching at an inclination angle of 0 to 40 degrees, it is possible to obtain a protective trowel film free of cavities and flavour defects.
It is effective in improving reliability such as corrosion resistance of thin-film magnetic heads.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the structure of a general thin film magnetic head.
FIGS. 2(a) to (C) are diagrams each showing the manufacturing process of the manufacturing method according to the prior art, and FIGS. . Explanation of symbols 1...Quahar 2...Conductor for electrode extraction 3...@1 Protective film 4...Base for current conduction 5.
・Photoresist 6...-Conductor 7--Inorganic protective film 8...Cavity 9...Flebast 10...Photoresist size for etching 1 Diagram 2 3 Mouth (f,) (C)

Claims (1)

[Claims] In an electrode manufacturing method for a thin film magnetic head, in which a magnetic head element and an electrode for connecting signals of the magnetic head element to the outside are formed on a substrate by thin film technology, an overhanging portion of a conductive film formed by an electroforming method is tapered. A method for producing an electrode for a thin film magnetic head, characterized in that a protective film is formed after removal by an etching method.