JPH0375924B2 - - Google Patents

Description

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

Prior Art A thin film magnetic head, which is generally formed by thin film technology, has a wafer 1 as a base, as shown in FIG.
and a magnetic head element 1 provided on the wafer 1.
0 and an electrode 20. Said electrode 2
0 is formed by thin film technology at the same time as the formation of the magnetic head element 10, and is for conducting between external terminals.

A second method of manufacturing the electrode 20 according to the conventional technology
This will be explained using figures. FIGS. 2a to 2c are cross-sectional views of an electrode showing the manufacturing process of the electrode according to the prior art. In this manufacturing method, first, as shown in FIG. 1A, a conductor 2 for leading out an electrode from a magnetic head element is formed on a wafer 1. Next, from the acidic or alkaline chemicals used during electroforming,
A first protective film 3 is formed to protect the magnetic head element. 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 of 2 to
A film is formed to a thickness of 10 μm 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 copper or nickel plating solution that can stably form a thick film. In this case, the film thickness of the conductor 6 is the same as that of the photoresist 5.
Up to a value similar to the film thickness of , the shape of the conductor 6 is as follows.
It is formed to follow the patterning shape of the photoresist 5. However, when the film thickness of the conductor 6 is formed to be thicker than that of 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. Precipitation occurs as shown in Figure 1a. This lateral precipitation progresses at a ratio of approximately 1:1 to the precipitation in the film thickness direction, and
If the 40 μm conductor 6 is formed by electroforming, an overhang of 10 to 30 μm will occur. When the photoresist 5 is removed, a gap equivalent to the thickness of the photoresist film will be created under the overhang portion. As shown in FIG. 1b, if an inorganic protective film 7 is subsequently formed by vacuum evaporation or sputtering, the gap under the overhang cannot be filled, and the conductor 6
Cavities 8 and crevasses 9 are formed in the inorganic protective film 7 around the
occurs. This defect appears around the electrode section when the surface of the inorganic protective film 7 is machined to expose the conductor 6 as shown in Figure 1c, and is the cause of a decrease in reliability from the perspective of corrosion resistance. It's summery.

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 problems caused by the above-mentioned prior art, and to provide a method for manufacturing thin film magnetic head electrodes that prevents the formation of cavities or crevasses and has excellent corrosion resistance. .

General Description of the Invention In order to achieve the above-mentioned object, the present invention involves forming a protective film after removing the overhanging part of the conductive film formed by electroforming by performing taper etching. It is characterized by

Embodiment of the Invention A method of manufacturing an electrode according to an embodiment of the invention will be described below with reference to FIGS. 3a to 3d.

The manufacturing method according to this embodiment, as shown in FIG. 3a, 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 the wafer 1, a conductor 2 for leading out an electrode, a first protective film 3, a base film 4 for current conduction, and a photoresist 5 are formed to have predetermined dimensions. After that, the electroforming method, which is easy to thicken the film, is used, for example, copper sulfate 220g/, sulfuric acid 775g/
A copper conductor 6 is formed using a copper sulfate plating solution consisting of: 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 patterning dimensions of the first protective film 3,
The larger the difference from 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 exposed or the copper of the current-carrying base film 4 is dissolved. As a result, as shown in FIG. 3b, the overhang portion of the copper conductor 6 is completely removed and the end portion of the copper conductor 6 can be etched at an angle of inclination of 30 to 40 degrees. When the conductor 6 of the thin film magnetic head electrode part having the structure of this embodiment is formed, after removing the photoresist 5 and the photoresist 10 for etching, an inorganic protective film 7 is formed as shown in FIG. 3c. has sufficient step coverage when the inclination angle of the conductor 6 is 40 degrees or less,
A defect-free film can be formed. Even when the surface of the inorganic protective film 7 is machined as shown in FIG. 3d, defects such as cavities and crevasses do not occur, so that an electrode portion with good corrosion resistance can be formed.

Effects of the Invention As described above, the present invention is characterized in that after forming the conductor film of the electrode part of the thin film magnetic head by electroforming, only the overhanging part of the conductor film is tapered etched. This prevents corrosion of the magnetic head element during etching. By etching the conductor film at an inclination angle of 30 to 40 degrees, a protective film free of cavities and crevasses can be obtained, which 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. 2a to 2c are diagrams showing manufacturing steps of a conventional manufacturing method, and FIGS. 3a to d are diagrams showing electrodes according to the present invention. It is a figure which shows the manufacturing process of the manufacturing method, respectively. Explanation of symbols 1... Wafer, 2... Conductor for electrode extraction, 3... First protective film, 4... Base for current conduction, 5... Photoresist, 6... Conductor, 7... Inorganic protective film, 8...
Cavity, 9...crevasse, 10...photoresist for etching.

Claims (1)

[Claims] 1. In a method for manufacturing an electrode for a thin film magnetic head in which a magnetic head element and an electrode for connecting a signal of the magnetic head element to the outside are formed on a substrate by thin film technology, an overhanging portion of a conductor film formed by an electroforming method is A method for manufacturing an electrode for a thin film magnetic head, characterized in that a protective film is formed after removal by a taper etching method.