JPH01112511A - Electrode forming method of thin film magnetic head - Google Patents

Abstract

PURPOSE:To obtain an electrode excellent for adhesion, corrosion resistance, and shock resistance by providing an inverse-trapezoidal mask onto a lead conductor, covering it by a protection film, removing the mask to expose the lead conductor layer and overlapping the lead electrode layer on the exposed face. CONSTITUTION:A pattern of the lead conductor layer 12 is formed on a base 11, a photo resist 14 is overlapped to form an inverse trapezoidal resist mask 19 by the image reverse method. The mask width on the conductor layer 12 is smaller than the width of the conductor layer 12. In overlapping the protection film 17 by the sputter method, a cavity 16 is caused. A peeling liquid is injected to the cavity 16 to remove the mask 19. A Cu film 13 is removed by applying the resist mask 14 to provide a solder layer 15. The mask 14 is removed to remove the exposed part of the Cu film 13 by the ion milling to complete the thin film magnetic head electrode with high reliability.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for forming electrodes of a thin film magnetic head, particularly a method for forming highly reliable electrodes. [Prior Art] General K, thin film A magnetic head is composed of a magnetic head element and electrodes provided on a common substrate. The magnetic head elements are sequentially laminated on the substrate! It consists of an ls magnetic pole, a gap material, a conductor coil, an upper f pole, etc., and electrodes are formed on the substrate to electrically connect the magnetic head element to the outside.

Figures 2 (a) to (h) are, for example, published in Japanese Patent Application Laid-Open No. 1983-2118.
The conventional spring shown in Publication No. 10! FIG. 2(h) is a sectional view illustrating a method for forming electrodes of a magnetic head in the order of steps, and FIG. 2(h) showing the final step shows the electrode portion of a thin film magnetic head formed by this conventional method. This figure 2 (h
), (11) is a substrate (wafer), and this substrate (11) is provided with a lead-out conductor layer (12) for guiding the flow of a magnetic head element (not shown). moreover,
A base gold fi layer (13) serving as a base film for plating is provided on the lead-out conductor layer (12), and this base metal layer (13)
An extraction electrode layer (15) is formed thereon. and,
Leads m<xs are bonded onto this extraction electrode layer (15).

Further, a protective film (17) is provided around the electrode section having such a structure and on the substrate (11).

Next, a method for forming electrodes of a conventional thin film magnetic head will be explained with reference to FIGS. 2(a) to 2(h).

First, after forming a pattern of 7 m (12) of lead conductors on the substrate (11), a base metal layer (13) as a base film for plating is applied, for example, by sputtering, on the base plate (11) and the lead conductor layer (12). A thickness of approximately 0.1 μrrL is formed by the method (FIG. 2(a)). While leaving the part on the lead-out conductor layer (12) where the electrode part is to be formed exposed, apply a 7-inch photoresist (
14) is patterned to a thickness of about 1 to 10 μm (
Figure 2(b)).

Next, this patterned 7 oto V cyst (14)
Using the electroplating method, a lead-out electrode layer (15) made of solder is placed on the exposed portion of the base metal layer (13).
After forming with a thickness of 0 to 40 μ9 (Fig. 2 (cl),
Peel off the photoresist (14). As a result, the drawer't! Both classes of L pole jc1 (15) have overhangs (
A hollow portion (16) is formed between both classes of extraction electrode # (15) and the underlying gold electrode layer (13).
π2 diagram (d)).

After that, the extraction conductor layer (12) is formed by ion milling.
In order to remove the underlying metal layer (13) while leaving the upper underlying metal layer (13), as shown in FIG. From this, a protective film (17) having a thickness of 30 to 40 μm is formed (see FIG. 2). In addition, at this time, the drawer fL-layer (15
) and the underlying metal layer (13) are maintained as they are.

After polishing the protection layer 11a (17), the extraction electrode layer (1
After exposing the surface of (742 (ω)), the lead, V7i! (18
) are heat-adhered. At this time, the hang constituting the extraction electrode layer (15) absorbs heat and melts, filling the cavity (16) and completely covering the base metal layer (13) (see Fig. 2 (h)). ). In this way, the electrode portion of the thin film magnetic head was formed.

[Problem that the invention seeks to solve]

In the conventional method for forming electrodes of a thin film magnetic head, as described above, the drawer '1 is formed by forming the protective film (15) after forming the pole layer (15).
7), the extraction electrode layer (1) was removed by polishing.
In order to expose the surface of the lead-out '1 electrode (15),
) had to be formed to have the same thickness as the protective film (17). Therefore, the extraction electrode layer (15) becomes considerably thick, which poses a problem in that the stress on the extraction electrode layer (15) becomes so great that it may peel off from the base metal layer (13).

Also, when polishing the protection 111K (17), the extraction electrode layer (1
5) may peel off, and when the pole layer (15) of the drawer melts, the cavity (16) will not be filled sufficiently, leaving 9 cavities on the surface of the base metal layer (13). There was also the problem that corrosion could occur.

In addition to the conventional examples mentioned above, Japanese Patent Application Laid-open No. 61-68714,
JP-A-60-140513 or JP-A-58-
179922 and other documents disclose methods for forming the electromagnetic part of a thin film magnetic head, but all of these methods involve forming an extraction electrode layer before forming a protective film, which causes the same problems as the conventional example shown in FIG. It has points.

This invention was made to solve these problems, and it forms a highly reliable electrode part that is free from the risk of peeling off of the extraction electrode layer or corrosion of the extraction electrode layer or base metal layer. One of the thin film magnetic heads that can be used! The purpose is to obtain a method for forming poles.

[Means for solving problems]

The method for forming electrodes of a thin-film magnetic head according to the present invention includes the steps of forming a mask having a uniform cross-sectional shape on the lead-out conductor layer, and forming a protective film over the entire surface of the substrate while masking the lead-out conductor layer with this mask. a step of removing the mask to expose the lead-out conductor layer, and a step of exposing the lead-out conductor layer 1-
forming an extraction electrode layer on the exposed surface of the electrode.

[For production]

In this invention, after forming the peritoneal membrane, the extraction conductor layer is exposed and the extraction electrode layer is formed there.

〔Example〕

FIGS. 1(a) to (il) are cross-sectional views illustrating one embodiment of the method for forming electrodes of a thin-film magnetic head according to the present invention in the order of steps, and FIG. The pole part of the thin film magnetic head to be formed is shown. In this figure 1 (i), the electrode part is provided on the substrate (11) and is connected to the magnetic head element (not shown). A lead-out conductor layer (1
2), a base metal layer (13) provided on this lead-out conductor layer (12) and serving as the base leg of the plating, and 1, a lead-out 11c pole layer (15) provided on this base metal layer (13). around this electrode part and the substrate (11
) is provided with a protective film (17).

next,! A method for forming an electrode portion having such a configuration will be described with reference to FIGS. 1(a) to 1(i).

First, after forming a pattern of the lead conductor layer (12) on the substrate (11) (FIG. 1(a)), a 70-mt. 4
Coat to a thickness of 0μ (Fig. 1(b)).

Next, the photoresist is patterned by the image reverse method, thereby forming a mask (19) having an inverted trapezoidal or inverted tapered cross-sectional shape on the central part of the lead-out conductor layer (12) (see Fig. 1). (C)).

Here, the image reversal method is a method of obtaining a reversal image from a normal positive resist, and is a method that allows various resist profiles to be obtained by controlling the process conditions at that time. The fact that a resist profile with an inverted trapezoidal cross-sectional shape can be obtained by this image reversal method is shown in the article by Yoshima Okamura, Hitoshi Yamamoto, Ginjibe Sato, and Shinji Yamamoto, "Profile Control and Dry Etching Characteristics of Image Reverse Photoresist." ”, Vacuum: g29, No. 12 (1981
5) K shown in detail.

Note that the mask (19) formed on the lead-out conductor layer (12)
) is set smaller than the width of the lead-out conductor layer (12).

Next, the mask (19) and the entire surface of the substrate (11) are sputtered to a thickness of 119 (17)'lr.
Form to ~30 μm. At this time, since the mask (19) has an inverted trapezoidal cross-sectional shape, no cavities (16) are formed on both sides of the mask (19) (Fig. 1(d)).
.

Furthermore, by injecting a normal stripping liquid into this cavity (16), a mask (19)' made of photoresist is removed.
/Remove Kie (11th iQl (el).

After that, a base metal layer (13) made of Cu is formed to a thickness of about 0.1 μm by sputtering on the 1m drawer container (12) and the guide plate (17) (Fig. 1(f)), and then the drawer groove While exposing the base metal layer (13) on the body layer (12), photoresist (14) is patterned to a depth of IJ to 15 μrr'Q on the base metal layer (13) of the curved part ( Figure 1(g)).

Next, this patterned photoresist (14)
A lead layer (15) made of solder is applied to the exposed part of the base metal-saving layer (13) using an electroplating method to a thickness of 5 to 50 mm.
10μ9 (FIG. 1(h)).

Furthermore, after peeling off the photoresist (14), the exposed base metal layer (13) is removed by ion milling (FIG. 1(i)).

In this way, the extraction electrode layer (
15) is formed.

In addition, in the above-mentioned example, the extraction electrode layer (15) was formed by the electroplating method, but it is not limited to this.
It can also be formed by a vapor deposition method, a sputtering method, or the like.

Further, according to the present invention, since the extraction electrode layer (15) is formed after the protective film (17) is formed, the extraction electrode layer (15) is formed after forming the protective film (17).
) is not required to be mechanically polished, but mechanical polishing may be performed to flatten the surface of the extraction electrode layer (15). At that time, as shown in FIG.
) is in close contact with the base metal layer (13) over a corresponding area, so there is no fear that the extraction electrode layer (15) will peel off even if it is polished.

〔Effect of the invention〕

As explained above, this invention includes the steps of forming a mask having an inverted trapezoidal cross-sectional shape on the lead-out conductor layer, and forming a protective film on the entire surface of the substrate while masking the lead-out conductor layer with this mask. The process includes the step of removing the mask to expose the lead conductor layer and the step of forming the lead electrode layer on the exposed surface of the lead conductor layer, so it does not contain any internal cavities and is thin and has excellent adhesion. An extraction electrode layer can be formed, and an electrode of a thin film magnetic head can be obtained which is extremely reliable in terms of corrosion resistance and durability against mechanical impact settling.

[Brief explanation of the drawing]

FIGS. 1(a) to (i) are cross-sectional views explaining one embodiment of the present invention in the order of steps, and FIGS. 2(a) to (h) are sectional views explaining a conventional method for forming electrodes of a thin-film magnetic head in the order of steps. FIG. In the figure, (11) is the substrate, (12) is the lead-out conductor layer,
(15) is an extraction electrode layer, (17) is a protective film, and (19) is a mask. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (3)

[Claims] (1) A step of forming a photoresist mask having an inverted trapezoidal cross-sectional shape on the lead-out conductor layer provided on the substrate, and a protective film on the entire surface of the substrate while masking the lead-out conductor layer with the mask. A thin film magnetic head characterized in that it includes the steps of: forming a lead conductor layer, removing the mask to expose the lead conductor layer, and forming a lead electrode layer on the exposed surface of the lead conductor layer. Electrode formation method. (2) The method for forming electrodes of a thin film magnetic head according to claim 1, wherein the mask is formed by an image reverse method. (3) A method for forming an electrode for a thin film magnetic head according to claim 1 or 2, wherein the extraction electrode layer is formed thinner than the protective film.