JPH0240118A - Thin film magnetic head - Google Patents

Abstract

PURPOSE:To obtain a magnetic head without generating a cavity or a crack in a protection film and coated completely and with a satisfactory characteristic and high reliability by providing a ring shape organic insulating member at the outer periphery of the base part of a bonding pad. CONSTITUTION:The ring shape organic insulating member 19 is formed at the outer periphery of the base part of the bonding pad 17, and the side peripheral part of the bonding pad 17 is enclosed with the organic insulating member 19 without leaving a gap. Furthermore, the protection film 20 is formed on an under coat film 12 including the organic insulating member 19 and an elctromagnetic transducing part 15, and only the bonding pad 17 is exposed on the surface of the protection film 20. Therefore, the protection film 20 is formed being stuck closely with the whole of bonding pad 17 and the outer peripheral plane of the ring shape organic insulating member 19. Also, the organic insulating member 19 are coated with the protection film 20 completely without being exposed on the surface. In such a way, it is possible to prevent the cavity or the crack from being generated on the protection film 20 in the periphery of the bonding pad 17, and to obtain a thin film magnetic head with a superior characteristic and with high reliability.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a thin film magnetic head.

(Prior art) In recent years, there have been increasing demands for higher density, smaller size (multi-track), and improved mass productivity for magnetic heads used in magnetic recording and reproducing devices. 2. Description of the Related Art Thin film magnetic heads manufactured using thin film forming techniques are being used.

As such a thin film magnetic head, one having the following structure is used.

FIG. 4 is a perspective view showing a conventional thin film magnetic head, and FIG. 5 is a perspective view showing a main part of FIG. 4 in cross section.

In these figures, reference numeral 1 indicates a substrate made of alumina, titanium, carbide, etc. On this substrate 1, an undercoat film 2 of alumina (Al1 03 ) etc. is formed, and on top of that is a magnetoelectric film. A converting section 3 is formed. The magnetoelectric converter 3 includes a lower magnetic core 4a and an upper magnetic core 4b each formed of a magnetic material such as permalloy, and a magnetic gap 5 formed between these and with a plurality of coil patterns interposed therebetween. It consists of Further, on the undercoat film 2 , a lead wire 6 is formed of a conductor such as copper, and an end of the lead wire 6 is connected to the magnetoelectric converter 3 . Further, a bonding pad 7 made of copper or the like for connecting a wire or a flexible substrate is provided at a predetermined position of the lead wire 6'' through a plating base thin film 8. Furthermore, on the undercoat film 2 including the top of the magnetoelectric conversion part 3 and the lead wire 6,
A protective film 9 made of alumina or the like is formed, and the bonding pads 7 are exposed on the surface of the protective film 9.

In such a conventional thin film magnetic head, the bonding pad 7 is manufactured by the method described below.

That is, as shown in FIG. 6(a), an undercoat film 2 is formed on a substrate 1 by a sputtering method, and a lead wire is formed on the undercoat film 2 along with a magnetoelectric transducer using a sputtering method and a photophosphorography technique. 6, a plating base thin film 8 of copper or the like is formed on the lead wire 6 including a portion of the undercoat film 2 by sputtering or the like (sixth plating film 8).
Figure (b)). Next, a ring-shaped frame 10 is formed using a plating resist on this plating base thin film 8 (FIG. 6(C)), and copper or the like is electroplated within this frame to form a bonding pad 7 (FIG. 6(C)). d)).

Next, after removing the resist frame 0 with a solvent such as acetone (FIG. 6(e)), the plating base thin film 8 is etched by irradiating with an ion beam or the like (FIG. 6(f)). Furthermore, the undercoat film 2 including the top of the honda pad 7
After forming a protective film 9 made of alumina or the like by sputtering or the like on the top and lead wires 6 (FIG. 6(g)), the protective film 9 is polished to flatten the surface and protect the bonding pad 7. exposed on the surface of the membrane 9 (Fig. 6 (h))
.

By the way, in such a formation method, the final thickness (t4) of the protective film 9 is at least 20 μm in order to flatten the surface including the magnetoelectric transducer having a step of about 15 μm.
A thickness of around μm is required.

Therefore, the thickness (t3) of the bonding pad 7 is 15
The thickness (t2) of the electric metal plate, such as copper, is required to be around 20μ at the minimum.

However, in terms of mass production, the thickness (tl) of the resist frame 10 is limited to about 10 μM, so the electroplated layer grows beyond the top surface of the resist frame 10.
As shown in FIGS. 6(d) to 6(g), the bonding pad 7 has a pine mushroom shape with a bulk extending upward and laterally.

Therefore, the protective film 9 cannot completely cover the outer surface of the bonding pad 7, and as shown in FIG. A cavity (A) may remain on the bottom), or a crack (B) may occur in the protective film 9 above it.

Due to these cavities and cracks, not only chips and gaps occur in the protective film 9 during the flattening process of the surface of the protective film 9, but also
Polishing particles and polishing debris may enter this gap and fall onto the surface of the medium when the thin film magnetic head is used, damaging the medium and the head.

(Problems to be Solved by the Invention) As mentioned above, in conventional thin-film magnetic heads, cavities, cracks, chips, etc. occur in the protective film around the bonding pads, and polishing debris remains in these gaps. However, there was a problem in that the reliability of the entire magnetic recording/reproducing device was greatly reduced.

The present invention has been made to solve these problems, and an object of the present invention is to provide a thin-film magnetic head that prevents cavities and cracks from forming in the protective film around the bonding pads, has good characteristics, and is highly reliable. With the goal.

[Structure of the Invention] (Means for Solving the Problems) A thin film magnetic head of the present invention includes a magnetoelectric transducer and a circuit pattern connected to the magnetoelectric transducer on a substrate, each formed by a thin film method. In a thin film magnetic head having a bonding pad formed at a predetermined position on the top, a ring-shaped organic insulating member is formed around the outer periphery of the main body of the pumping pad, and the outside of this organic insulating member is completely covered with a protective film. It is coated.

(Function) In the thin-film magnetic head of the present invention, a ring-shaped organic insulating member is formed surrounding the core of the bonding pad. Even if it has a pine mushroom shape, there are no shadow areas where sputtered particles cannot reach during the process of forming a protective film. Therefore, the protective film is formed in close contact with the entire outer peripheral surface of the bonding pad and the ring-shaped organic insulating member, and no cavities or cracks are formed.

Further, since this organic insulating member is completely covered with a protective film and is not exposed on the surface, sufficient durability can be maintained.

(Example) Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a partially sectional perspective view of an embodiment of the thin film magnetic head of the present invention.

In the figure, reference numeral 11 indicates a substrate made of alumina, titanium, cavite, etc., and an undercoat film 2 made of alumina, etc. is formed on this substrate 11. Then, on this undercoat film 12, a magnetoelectric transducer 15 is formed, which is composed of lower and upper magnetic cores 13a and 13b formed of a magnetic material, respectively, and a magnetic gap 14 formed between them. It is provided. This magnetoelectric converter 15 includes a lead line 16 formed on the undercoat film 12.
is connected. Further, a bonding pad 17 made of copper or the like is provided at a predetermined position on the lead wire 16 with a plating base thin film 18 interposed therebetween. A ring-shaped organic insulating member 19 is formed on the outer periphery of the core portion of the bonding pad 17.
The side periphery of 7 is surrounded by this organic insulating member 9 without any gaps. Further, on the organic insulating member 19 and the magnetoelectric converter 1
A protective film 20 is formed on the undercoat film 12 including on the undercoat film 5 , and only the bonding pads 17 are exposed on the surface of the protective film 20 .

In an embodiment of such a structure, the bonding pad 17 and the like are formed by the following method.

FIG. 2 is a partially sectional perspective view for explaining the method of forming the bonding pads 17 and the like.

That is, first, the undercoat film 12 and the lead line 16 are sequentially formed on the substrate 11 using sputtering, photolithography, etc. (FIG. 2(a)), and then a portion of the undercoat film 12 is formed. Including, on the leader line 16,
A metal base thin film 18 of copper or the like is formed by sputtering (FIG. 2(b)). Next, this plating base thin film 1
One ring-shaped organic insulating member is formed on 8. The organic insulating member 19 is formed by, for example, applying a positive photoresist, heat curing it at a temperature of about 200°C, and making it insoluble in a solvent such as acetone (see Fig. 2(C)). ). Next, after forming a frame 21 using plating resist on the outside of this organic insulating member 19 (FIG. 2(d)), copper or the like is electroplated into this resist frame 21 to form bonding pads 17. form (second
Figure (d)).

Next, the resist frame 21 is removed using a solvent such as acetone (FIG. 2(e)), and the underlying thin film 18 is ion beam etched (FIG. 2(f)).
), a protective film 20 is applied over these by sputtering or the like.
(Fig. 2(g)).

After that, the surface of the protective film 20 is planarized, and the bonding pad 17 is exposed on the surface of the protective film 20 (a second
Figure (h)).

As described above, in the formed thin film magnetic head of the example, in the process of forming the protective film 20 (FIG. 2(g))
Since the organic insulating member 19 is provided in a ring shape under the umbrella part (outside the side periphery of the bonding pad 17) which is in the shadow of the bonding pad 17 and where the sputtered particles cannot reach, the protective film 20 does not have a cavity or without cracking,
Completely coat the entire outside of these. Therefore, even in the step of planarizing the surface of the protective film 20, no chips or gaps are generated in the protective film 20, and a highly reliable thin film magnetic head can be obtained. Furthermore, since the organic insulating member 19 is not exposed on the surface of the protective film 20, it has sufficient durability.

Furthermore, the bonding pads 17 and the like in the thin film magnetic head of the embodiment can also be formed as follows.

That is, after forming the undercoat film 12 and the leader lines 16 on the substrate 11 in this order by sputtering and photolithography techniques (FIG. 3(a)), a plating base thin film 18 is formed on the leader lines 16 by sputtering. 3(b)), and then a resin paint is applied thereon in a ring shape and thermally cured at about 200°C to form a resist frame 21 made of an organic insulating material (Fig. 3(b)). (C)). Next, this resist frame 21
After forming a bonding pad 17 by electroplating copper or the like (FIG. 3(d)), the resist frame 21 is subjected to reactive ion etching by irradiating with 02 plasma or the like.

At this time, the portion below the upper bulk of the bonding pad 17 of the resist frame 21 is
Since it is shielded by 7, it remains in a ring shape (
Figure 3(e)). Next, after ion beam etching the plating base thin film 18 (FIG. 3(f)), a protective film 20 is formed over the entire surface by sputtering method (FIG. 3(g)). The surface is flattened to expose the bonding pad 17 on the surface (FIG. 3(h)).

According to the method described above, a part of the resist frame 21 made of an organic insulating material remains in a ring shape under the upper bulk part (around the main part) of the bonding pad 17, so that a film is not formed on this part. It is possible to obtain a highly reliable thin film magnetic head in which no cavities or cracks are formed in the protective film 20 and no polishing debris or the like is mixed in.

Furthermore, in this method, a portion of the resist frame 21 is removed using active ion etching such as 02 plasma, leaving a portion of the resist frame 21 located under the bulk of the bonding pad 17.
There is no need to newly form a ring-shaped organic insulating member around the core portion of the bonding pad 17. therefore,
It has the advantage that the formation process is simplified and manufacturing efficiency is high.

[Effects of the Invention] As explained above, in the thin film magnetic head of the present invention, a ring-shaped organic insulating member is provided around the outer periphery of the core portion of the bonding pad. In the process of forming the protective film, it is possible to completely coat the protective film without creating cavities or cracks. In addition, a thin film magnetic head with good characteristics and high reliability can be provided.

[Brief explanation of the drawing]

FIG. 1 is a partially cross-sectional perspective view showing an embodiment of the thin film magnetic head of the present invention, and FIGS. 3(a) to 3(h) are sectional views for explaining another method of forming bonding pads, etc., FIG. 4 is a perspective view showing a conventional thin film magnetic head, and FIG. FIGS. 6(a) to 6(h) are cross-sectional views for explaining a method of forming bonding pads and the like in a conventional thin-film magnetic head. FIGS. 1, ] 1... Substrate, 3.15... Magnetoelectric conversion unit, 6,
16...Leader wire, 7.17...Pumping wire, 9.20...Protective film, 10.21...Resist frame, one...Ring-shaped organic insulating member. Applicant: Toshiba Corporation

Claims (1)

[Claims] (1) A thin film magnetic head in which a magnetoelectric transducer and a circuit pattern connected thereto are each formed by a thin film method on a substrate, and a bonding pad is formed at a predetermined position on the circuit pattern. A thin film magnetic head characterized in that a ring-shaped organic insulating member is formed around the outer periphery of a core portion of a pad, and the outside of this organic insulating member is completely covered with a protective film.