JPH064830A - Thin-film magnetic head - Google Patents

Abstract

PURPOSE:To prevent the degradation in electrical reliability by the generation of a crack in the lower part of a terminal. CONSTITUTION:A terminal pedestal film 2 consisting of a photoresist is formed in the part on a lower insulating film 17 where the terminal 4 is formed. This terminal pedestal film 2 is hardened by a heating treatment, by which the sectional shape thereof is made into a trapezoidal shape. An NiFe plating film 3 is formed on a coil leader electrode 1 and the terminal pedestal film 2 in such a manner that the coil leader electrode 1 and the terminal 4 are electrically connected. The terminal 4 is formed on the NiFe plating film 3 of the part formed with the terminal pedestal film 2, by which the plating film thickness of the terminal is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film magnetic head,
In particular, it relates to improvement of reliability of a terminal portion for connecting the thin film magnetic head to an external device.

[0002]

2. Description of the Related Art FIG. 5 is a front view of a conventional thin film magnetic head,
6 is a plan view of the main part of this thin film magnetic head, FIG. 7 is a sectional view taken along the line II of FIG. 6, and FIG. 8 is a sectional view taken along the line II-II of FIG. In each figure, the same parts are designated by the same reference numerals. In FIG. 5, 10 is a magnetic medium such as a magnetic disk, 11 is an upper magnetic film that constitutes the core of a thin film magnetic head, 12 is an electromagnetic conversion element section that also includes the upper magnetic film 11, and 13 is a coil extraction electrode described later. NiFe plating film formed on the surface of the film to prevent oxidation, 14
Is a terminal for connecting the thin film magnetic head to an external device (not shown), and 15 is a protective film for protecting the thin film magnetic head. In FIG. 6, 16 is a substrate for fixing and holding and moving the thin film magnetic head, 17 is a lower insulating film for the purpose of insulating from a magnetic film formed on the substrate 16, 1
Reference numeral 8 is a lower magnetic film that constitutes the core of the thin film magnetic head together with the upper magnetic film 11.

Next, in FIG. 7, the rightward direction of the drawing will be referred to as the upward direction, and the following description will be given. Reference numeral 19 is a lower coil insulating film, 20 is a coil made of a conductive material formed in a ring shape on the lower coil insulating film 19, and 21 is an upper coil insulating film formed on the lower coil insulating film 19 and the coil 20. The above lower magnetic film 18, lower coil insulating film 19, coil 20,
The electromagnetic conversion element portion 12 (FIGS. 5 and 6) composed of the upper coil insulating film 21 and the upper magnetic film 11 is the main part of the thin film magnetic head. In FIG. 8, 22 is a coil 20.
And a coil lead-out electrode for connecting the terminal 14 to the terminal 14. Reference numeral 23 denotes a cavity formed under the terminal 14, which will be described in detail later.

First, a manufacturing process of such a conventional thin film magnetic head will be described. After forming the lower magnetic film 18 made of a NiFe plating film on the lower insulating film 17, a lower coil insulating film 19 made of a photoresist is formed on the lower magnetic film 18 and on the right side thereof by a photolithography process. After the heat treatment is performed to harden the lower coil insulating film 19, a coil 20 is formed on the lower coil insulating film 19 to form a coil 20 around the core formed of the lower magnetic film 18 and the upper magnetic film 11. Simultaneously with the coil 20, the coil lead-out electrode 22 is formed so as to electrically connect the coil 20 and the terminal 14.

Next, the upper coil insulating film 21 made of photoresist is formed on the coil 20 by a photolithography process.
After being formed on the upper coil insulating film 21 and hardened by heat treatment, the upper magnetic film 11 made of a NiFe plating film is formed on the upper coil insulating film 21.
To form. A NiFe plating film 13 for preventing the oxidation is formed on the coil extraction electrode 22 at the same time as the upper magnetic film 11. A gap film (not shown) having a thickness of 3000 to 4000 Å is formed between the left end of the lower magnetic film 18 and the left end of the upper magnetic film 11 by a sputtering process, and this is the gap of the core of the thin film magnetic head.

In the terminal portion shown in FIG. 8, a pattern having a thickness of 15 μm is formed on the NiFe plated film 13 by photoresist so as to cover the entire surface except the portion where the terminal 14 is formed.
The terminal 14 is formed in a thickness of 50 to 60 μm by a Cu plating process so as to have a thickness equal to or greater than that of the electromagnetic conversion element portion 12. When formed, the cross-sectional shape of the terminal 14 becomes an umbrella shape in which the upper portion spreads to the left and right. The reason for this is that the terminals 14 can be formed vertically depending on the thickness of the photoresist, but the terminals 14 extend over the pattern in a portion having a thickness greater than that of the photoresist. After removing the photoresist, the protective film 15 is formed so as to cover the entire electromagnetic conversion element portion 12. After that, the surface is polished until the terminal 14 is exposed on the surface of the protective film 15, and the thin film magnetic head is completed.

During magnetic recording in such a thin film magnetic head, an alternating current is passed from an external device (not shown) to the coil 20 connected to the terminal 14 to generate a magnetic field from the gap of the core and move in the direction of the arrow in FIG. The change in current is recorded on the magnetic medium 10 as the change in residual magnetic flux density. During magnetic reproduction, a change in magnetic flux of the magnetic medium 10 is generated as a weak induced voltage in the coil 20, and the generated induced voltage is applied to the terminal 14
To an external device (not shown).

[0008]

In the protective film 15, only the protective film 15 is unevenly shaved due to processing of the surface facing the magnetic medium 10 or the like, and the scraped portion of the protective film 15 on the surface facing the magnetic medium 10 is removed. In order to prevent dust from accumulating, the same hardness as the substrate 16 is required. Therefore, since the protective film 15 is made of alumina and has a high rate of being formed in the vertical direction by the sputtering process and does not spread to the left and right, it is not formed under the umbrella. The result is a cavity 23 at the bottom of the umbrella.

When an external impact is applied to the terminal 14 by the above-mentioned polishing process and handling for exposing the terminal 14 on the surface of the protective film 15, the coil lead electrode 22 near the bottom of the cavity 23 and NiFe plating. A force is applied to the membrane 13. The substrate 16, the lower insulating film 17, and the protective film 15 are hard, and the coil lead electrode 22 and the NiFe plating film 1 are provided.
Since 3 is as thin as 4 μm, a crack is generated in the coil lead electrode 22 and the NiFe plating film 13 by this force. Therefore, the coil lead electrode 22 and the terminal 1
The electrical connection with No. 4 became unstable, and the reliability of the input / output of the signal composed of the alternating current and the induced voltage was not sufficient.

[0010]

According to the present invention, a terminal pedestal film formed on a lower insulating film and a NiF formed on a coil lead electrode in a shape extending to the terminal pedestal film.
e-plated film and NiFe in the part where the terminal pedestal film is formed
And a terminal formed on the plated film.

[0011]

According to the present invention, the plating thickness of the terminal can be reduced by forming an insulating film under the terminal of the thin film magnetic head to obtain a desired height, so that a cavity is formed in the lower portion of the terminal. Can be prevented.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a terminal portion of a thin film magnetic head showing an embodiment of the present invention. The electromagnetic conversion element portion 12 is the same as in the conventional example shown in FIGS. Reference numeral 1 is a coil extraction electrode, 2 is a terminal pedestal film made of photoresist formed at a predetermined height to reduce the thickness of the terminal, 3 is a NiFe plating film formed at the same time as the upper magnetic film 11, and 4 is It is a terminal. The same parts as those in FIG. 8 showing the conventional example are designated by the same reference numerals.

First, the manufacturing process of the terminal portion of the thin film magnetic head of the present invention will be described. Unlike the example of FIG. 8, the coil lead electrode 1 formed simultaneously with the coil 20 is not formed in the lower layer of the terminal 4. This is because the terminal pedestal film 2 is formed on the lower layer of the terminal 4 even if the lower layer of the terminal 4 is formed, so that the coil lead electrode 1 is not hidden and electrically connected to the NiFe plated film 3. is there.

After the upper coil insulating film 21 is formed, the terminal pedestal film 2 is formed by applying a resist on the lower insulating film 17 as a lower layer of the terminal 4 by a photoresist exposure technique. Photoresist film thickness is at least 10-1
5 μm. 2 of the terminal pedestal film 2 formed in the above process
Harden by heat treatment at a temperature of 00 to 300 ° C. At this time, the cross-sectional shape of the terminal pedestal film 2 becomes a trapezoidal shape in which the lower part is expanded by the heat treatment.

The NiFe plating film 3 is formed on the coil lead electrode 1 and the terminal pedestal film 2 at the same time as the formation of the upper magnetic film 11 and in a shape that electrically connects the coil lead electrode 1 and the terminal 4. A photoresist pattern of a terminal is formed on the NiFe plated film 3 where the terminal pedestal film 2 is formed by a photoresist exposure technique, and a terminal 4 is formed by Cu plating. The film thickness of the photoresist pattern of the terminal is set to 15 μm or more, and the Cu plating film thickness of the terminal 4 is set to about 20 μm because it can be reduced by the thickness of the terminal pedestal film 2. By forming the terminal 4 on the NiFe plating film 3, the coil lead electrode 1 and the terminal 4 are electrically connected. After removing the photoresist pattern,
The protective film 17 is formed from above. In the completed thin film magnetic head, the plating film thickness of the terminal 4 is thin and the sectional shape of the terminal pedestal film 2 is trapezoidal.

FIG. 2 is a sectional view of a terminal portion of a thin film magnetic head showing another embodiment of the present invention. This embodiment has a structure in which the NiFe plating film 3 entirely covers the terminal pedestal film 2 as compared with the thin film magnetic head of the embodiment of FIG. In this case, the generation of cavities on the trapezoidal side surface of the terminal pedestal film 2 can be further suppressed, so that the reliability can be further improved.

FIG. 3 is a sectional view of a terminal portion of a thin film magnetic head showing another embodiment of the present invention. The steps up to the formation of the lower magnetic film 18 are the same as those in FIG. 7, but the first terminal pedestal film 2a is formed simultaneously with the lower coil insulating film 19. After the heat treatment, the coil extraction electrode 1 is formed in the same manner as in the embodiment shown in FIG. Next, the second terminal pedestal film 2b is formed simultaneously with the upper coil insulating film 21. The steps after the heat treatment are the same as those in the embodiment of FIG. In the present embodiment, the second terminal pedestal film 2b is smaller than the first terminal pedestal film 2a, each of which is formed in a trapezoidal shape, and the first terminal pedestal film 2a and the second terminal pedestal film 2b are formed. The combined shape is trapezoidal, and the same effect as the example of FIG. 1 is obtained. Also, the first
By simultaneously forming the insulating film 2a and the second insulating film 2b of the lower coil insulating film 19 and the upper coil insulating film 21 respectively, the formation of the insulating film 2 and the heat treatment as shown in FIG. The number of steps can be reduced as compared with the embodiment of FIG.

FIG. 4 is a sectional view of a terminal portion of a thin film magnetic head showing another embodiment of the present invention. As in FIG. 2, the first terminal pedestal film 2a and the second terminal pedestal film 2b are all made of NiF.
Since the structure is covered with the e-plated film 3, the reliability can be further improved as compared with the structure of FIG.

[0019]

As described above, according to the present invention, it is possible to prevent the formation of a cavity under the terminal. Therefore, even if an external impact is applied to the terminal, the NiFe plating film and the coil lead-out electrode are not cracked. A thin film magnetic head that does not generate and has high reliability of input / output of a signal composed of an alternating current and an induced voltage can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view of a terminal portion in an embodiment of a thin film magnetic head according to the present invention.

FIG. 2 is a sectional view of a terminal portion in another embodiment of the thin film magnetic head according to the present invention.

FIG. 3 is a sectional view of a terminal portion in another embodiment of the thin film magnetic head according to the present invention.

FIG. 4 is a sectional view of a terminal portion in another embodiment of the thin film magnetic head according to the present invention.

FIG. 5 is a front view of a conventional thin film magnetic head.

FIG. 6 is a plan view of a main part of a conventional thin film magnetic head.

7 is a cross-sectional view taken along the line II of FIG.

8 is a sectional view taken along the line II-II of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 coil extraction electrode 2 terminal pedestal film 2a first terminal pedestal film 2b second terminal pedestal film 3 NiFe plating film 4 terminal 10 magnetic medium 11 upper magnetic film 12 electromagnetic transducer element 15 protective film 16 substrate 17 lower insulating film 18 Lower magnetic film 19 Lower coil insulating film 20 Coil 21 Upper coil insulating film

Claims (2)

[Claims] 1. A lower magnetic film formed on a lower insulating film of a substrate, a lower coil insulating film formed on the lower magnetic film, and a coil formed on the lower coil insulating film.
A coil lead electrode connected to the coil, an upper coil insulating film formed on the coil, an upper magnetic film formed on the upper coil insulating film, and a protective film protecting each of the components. A thin film magnetic head having the terminal pedestal film formed on the lower insulating film, a NiFe plating film formed on the coil lead electrode in a shape extending to the terminal pedestal film, and the terminal pedestal film. A thin film magnetic head having a terminal formed on the NiFe plating film in a portion where the film is formed. 2. The thin film magnetic head according to claim 1, wherein the terminal pedestal film is a first terminal pedestal film formed on the lower insulating film, and a first terminal pedestal film is formed on the first terminal pedestal film. 2. A thin film magnetic head comprising a terminal base film of 2.